xref: /freebsd/sys/netinet/tcp_stacks/rack.c (revision ea916b64) 
1 /*-
2  * Copyright (c) 2016-2020 Netflix, Inc.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  *
25  */
26 
27 #include <sys/cdefs.h>
28 #include "opt_inet.h"
29 #include "opt_inet6.h"
30 #include "opt_ipsec.h"
31 #include "opt_ratelimit.h"
32 #include "opt_kern_tls.h"
33 #if defined(INET) || defined(INET6)
34 #include <sys/param.h>
35 #include <sys/arb.h>
36 #include <sys/module.h>
37 #include <sys/kernel.h>
38 #ifdef TCP_HHOOK
39 #include <sys/hhook.h>
40 #endif
41 #include <sys/lock.h>
42 #include <sys/malloc.h>
43 #include <sys/lock.h>
44 #include <sys/mutex.h>
45 #include <sys/mbuf.h>
46 #include <sys/proc.h>		/* for proc0 declaration */
47 #include <sys/socket.h>
48 #include <sys/socketvar.h>
49 #include <sys/sysctl.h>
50 #include <sys/systm.h>
51 #ifdef STATS
52 #include <sys/qmath.h>
53 #include <sys/tree.h>
54 #include <sys/stats.h> /* Must come after qmath.h and tree.h */
55 #else
56 #include <sys/tree.h>
57 #endif
58 #include <sys/refcount.h>
59 #include <sys/queue.h>
60 #include <sys/tim_filter.h>
61 #include <sys/smp.h>
62 #include <sys/kthread.h>
63 #include <sys/kern_prefetch.h>
64 #include <sys/protosw.h>
65 #ifdef TCP_ACCOUNTING
66 #include <sys/sched.h>
67 #include <machine/cpu.h>
68 #endif
69 #include <vm/uma.h>
70 
71 #include <net/route.h>
72 #include <net/route/nhop.h>
73 #include <net/vnet.h>
74 
75 #define TCPSTATES		/* for logging */
76 
77 #include <netinet/in.h>
78 #include <netinet/in_kdtrace.h>
79 #include <netinet/in_pcb.h>
80 #include <netinet/ip.h>
81 #include <netinet/ip_icmp.h>	/* required for icmp_var.h */
82 #include <netinet/icmp_var.h>	/* for ICMP_BANDLIM */
83 #include <netinet/ip_var.h>
84 #include <netinet/ip6.h>
85 #include <netinet6/in6_pcb.h>
86 #include <netinet6/ip6_var.h>
87 #include <netinet/tcp.h>
88 #define	TCPOUTFLAGS
89 #include <netinet/tcp_fsm.h>
90 #include <netinet/tcp_seq.h>
91 #include <netinet/tcp_timer.h>
92 #include <netinet/tcp_var.h>
93 #include <netinet/tcp_log_buf.h>
94 #include <netinet/tcp_syncache.h>
95 #include <netinet/tcp_hpts.h>
96 #include <netinet/tcp_ratelimit.h>
97 #include <netinet/tcp_accounting.h>
98 #include <netinet/tcpip.h>
99 #include <netinet/cc/cc.h>
100 #include <netinet/cc/cc_newreno.h>
101 #include <netinet/tcp_fastopen.h>
102 #include <netinet/tcp_lro.h>
103 #ifdef NETFLIX_SHARED_CWND
104 #include <netinet/tcp_shared_cwnd.h>
105 #endif
106 #ifdef TCP_OFFLOAD
107 #include <netinet/tcp_offload.h>
108 #endif
109 #ifdef INET6
110 #include <netinet6/tcp6_var.h>
111 #endif
112 #include <netinet/tcp_ecn.h>
113 
114 #include <netipsec/ipsec_support.h>
115 
116 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
117 #include <netipsec/ipsec.h>
118 #include <netipsec/ipsec6.h>
119 #endif				/* IPSEC */
120 
121 #include <netinet/udp.h>
122 #include <netinet/udp_var.h>
123 #include <machine/in_cksum.h>
124 
125 #ifdef MAC
126 #include <security/mac/mac_framework.h>
127 #endif
128 #include "sack_filter.h"
129 #include "tcp_rack.h"
130 #include "tailq_hash.h"
131 #include "rack_bbr_common.h"
132 
133 uma_zone_t rack_zone;
134 uma_zone_t rack_pcb_zone;
135 
136 #ifndef TICKS2SBT
137 #define	TICKS2SBT(__t)	(tick_sbt * ((sbintime_t)(__t)))
138 #endif
139 
140 VNET_DECLARE(uint32_t, newreno_beta);
141 VNET_DECLARE(uint32_t, newreno_beta_ecn);
142 #define V_newreno_beta VNET(newreno_beta)
143 #define V_newreno_beta_ecn VNET(newreno_beta_ecn)
144 
145 #define	M_TCPFSB	__CONCAT(M_TCPFSB, STACKNAME)
146 #define	M_TCPDO		__CONCAT(M_TCPDO, STACKNAME)
147 
148 MALLOC_DEFINE(M_TCPFSB, "tcp_fsb_" __XSTRING(STACKNAME), "TCP fast send block");
149 MALLOC_DEFINE(M_TCPDO, "tcp_do_" __XSTRING(STACKNAME), "TCP deferred options");
150 MALLOC_DEFINE(M_TCPPCM, "tcp_pcm_" __XSTRING(STACKNAME), "TCP PCM measurement information");
151 
152 struct sysctl_ctx_list rack_sysctl_ctx;
153 struct sysctl_oid *rack_sysctl_root;
154 
155 #define CUM_ACKED 1
156 #define SACKED 2
157 
158 /*
159  * The RACK module incorporates a number of
160  * TCP ideas that have been put out into the IETF
161  * over the last few years:
162  * - Matt Mathis's Rate Halving which slowly drops
163  *    the congestion window so that the ack clock can
164  *    be maintained during a recovery.
165  * - Yuchung Cheng's RACK TCP (for which its named) that
166  *    will stop us using the number of dup acks and instead
167  *    use time as the gage of when we retransmit.
168  * - Reorder Detection of RFC4737 and the Tail-Loss probe draft
169  *    of Dukkipati et.al.
170  * RACK depends on SACK, so if an endpoint arrives that
171  * cannot do SACK the state machine below will shuttle the
172  * connection back to using the "default" TCP stack that is
173  * in FreeBSD.
174  *
175  * To implement RACK the original TCP stack was first decomposed
176  * into a functional state machine with individual states
177  * for each of the possible TCP connection states. The do_segment
178  * functions role in life is to mandate the connection supports SACK
179  * initially and then assure that the RACK state matches the conenction
180  * state before calling the states do_segment function. Each
181  * state is simplified due to the fact that the original do_segment
182  * has been decomposed and we *know* what state we are in (no
183  * switches on the state) and all tests for SACK are gone. This
184  * greatly simplifies what each state does.
185  *
186  * TCP output is also over-written with a new version since it
187  * must maintain the new rack scoreboard.
188  *
189  */
190 static int32_t rack_tlp_thresh = 1;
191 static int32_t rack_tlp_limit = 2;	/* No more than 2 TLPs w-out new data */
192 static int32_t rack_tlp_use_greater = 1;
193 static int32_t rack_reorder_thresh = 2;
194 static int32_t rack_reorder_fade = 60000000;	/* 0 - never fade, def 60,000,000
195 						 * - 60 seconds */
196 static uint16_t rack_policer_rxt_thresh= 0;	/* 499 = 49.9%, 0 is off  */
197 static uint8_t rack_policer_avg_thresh = 0; /* 3.2 */
198 static uint8_t rack_policer_med_thresh = 0; /* 1 - 16 */
199 static uint16_t rack_policer_bucket_reserve = 20; /* How much % is reserved in the bucket */
200 static uint64_t rack_pol_min_bw = 125000;	/* 1mbps in Bytes per sec */
201 static uint32_t rack_policer_data_thresh = 64000;	/* 64,000 bytes must be sent before we engage */
202 static uint32_t rack_policing_do_bw_comp = 1;
203 static uint32_t rack_pcm_every_n_rounds = 100;
204 static uint32_t rack_pcm_blast = 0;
205 static uint32_t rack_pcm_is_enabled = 1;
206 static uint8_t rack_req_del_mss = 18;	/* How many segments need to be sent in a recovery episode to do policer_detection */
207 static uint8_t rack_ssthresh_rest_rto_rec = 0; /* Do we restore ssthresh when we have rec -> rto -> rec */
208 
209 static uint32_t rack_gp_gain_req = 1200;		/* Amount percent wise required to gain to record a round has "gaining" */
210 static uint32_t rack_rnd_cnt_req = 0x10005;		/* Default number of rounds if we are below rack_gp_gain_req where we exit ss */
211 
212 
213 static int32_t rack_rxt_scoreboard_clear_thresh = 2;
214 static int32_t rack_dnd_default = 0;		/* For rr_conf = 3, what is the default for dnd */
215 static int32_t rack_rxt_controls = 0;
216 static int32_t rack_fill_cw_state = 0;
217 static uint8_t rack_req_measurements = 1;
218 /* Attack threshold detections */
219 static uint32_t rack_highest_sack_thresh_seen = 0;
220 static uint32_t rack_highest_move_thresh_seen = 0;
221 static uint32_t rack_merge_out_sacks_on_attack = 0;
222 static int32_t rack_enable_hw_pacing = 0; /* Due to CCSP keep it off by default */
223 static int32_t rack_hw_pace_extra_slots = 0;	/* 2 extra MSS time betweens */
224 static int32_t rack_hw_rate_caps = 0; /* 1; */
225 static int32_t rack_hw_rate_cap_per = 0;	/* 0 -- off  */
226 static int32_t rack_hw_rate_min = 0; /* 1500000;*/
227 static int32_t rack_hw_rate_to_low = 0; /* 1200000; */
228 static int32_t rack_hw_up_only = 0;
229 static int32_t rack_stats_gets_ms_rtt = 1;
230 static int32_t rack_prr_addbackmax = 2;
231 static int32_t rack_do_hystart = 0;
232 static int32_t rack_apply_rtt_with_reduced_conf = 0;
233 static int32_t rack_hibeta_setting = 0;
234 static int32_t rack_default_pacing_divisor = 250;
235 static uint16_t rack_pacing_min_seg = 0;
236 static int32_t rack_timely_off = 0;
237 
238 static uint32_t sad_seg_size_per = 800;	/* 80.0 % */
239 static int32_t rack_pkt_delay = 1000;
240 static int32_t rack_send_a_lot_in_prr = 1;
241 static int32_t rack_min_to = 1000;	/* Number of microsecond  min timeout */
242 static int32_t rack_verbose_logging = 0;
243 static int32_t rack_ignore_data_after_close = 1;
244 static int32_t rack_enable_shared_cwnd = 1;
245 static int32_t rack_use_cmp_acks = 1;
246 static int32_t rack_use_fsb = 1;
247 static int32_t rack_use_rfo = 1;
248 static int32_t rack_use_rsm_rfo = 1;
249 static int32_t rack_max_abc_post_recovery = 2;
250 static int32_t rack_client_low_buf = 0;
251 static int32_t rack_dsack_std_based = 0x3;	/* bit field bit 1 sets rc_rack_tmr_std_based and bit 2 sets rc_rack_use_dsack */
252 static int32_t rack_bw_multipler = 0;		/* Limit on fill cw's jump up to be this x gp_est */
253 #ifdef TCP_ACCOUNTING
254 static int32_t rack_tcp_accounting = 0;
255 #endif
256 static int32_t rack_limits_scwnd = 1;
257 static int32_t rack_enable_mqueue_for_nonpaced = 0;
258 static int32_t rack_hybrid_allow_set_maxseg = 0;
259 static int32_t rack_disable_prr = 0;
260 static int32_t use_rack_rr = 1;
261 static int32_t rack_non_rxt_use_cr = 0; /* does a non-rxt in recovery use the configured rate (ss/ca)? */
262 static int32_t rack_persist_min = 250000;	/* 250usec */
263 static int32_t rack_persist_max = 2000000;	/* 2 Second in usec's */
264 static int32_t rack_honors_hpts_min_to =  1;	/* Do we honor the hpts minimum time out for pacing timers */
265 static uint32_t rack_max_reduce = 10;		/* Percent we can reduce slot by */
266 static int32_t rack_sack_not_required = 1;	/* set to one to allow non-sack to use rack */
267 static int32_t rack_limit_time_with_srtt = 0;
268 static int32_t rack_autosndbuf_inc = 20;	/* In percentage form */
269 static int32_t rack_enobuf_hw_boost_mult = 0;	/* How many times the hw rate we boost slot using time_between */
270 static int32_t rack_enobuf_hw_max = 12000;	/* 12 ms in usecs */
271 static int32_t rack_enobuf_hw_min = 10000;	/* 10 ms in usecs */
272 static int32_t rack_hw_rwnd_factor = 2;		/* How many max_segs the rwnd must be before we hold off sending */
273 static int32_t rack_hw_check_queue = 0;		/* Do we always pre-check queue depth of a hw queue */
274 static int32_t rack_full_buffer_discount = 10;
275 /*
276  * Currently regular tcp has a rto_min of 30ms
277  * the backoff goes 12 times so that ends up
278  * being a total of 122.850 seconds before a
279  * connection is killed.
280  */
281 static uint32_t rack_def_data_window = 20;
282 static uint32_t rack_goal_bdp = 2;
283 static uint32_t rack_min_srtts = 1;
284 static uint32_t rack_min_measure_usec = 0;
285 static int32_t rack_tlp_min = 10000;	/* 10ms */
286 static int32_t rack_rto_min = 30000;	/* 30,000 usec same as main freebsd */
287 static int32_t rack_rto_max = 4000000;	/* 4 seconds in usec's */
288 static const int32_t rack_free_cache = 2;
289 static int32_t rack_hptsi_segments = 40;
290 static int32_t rack_rate_sample_method = USE_RTT_LOW;
291 static int32_t rack_pace_every_seg = 0;
292 static int32_t rack_delayed_ack_time = 40000;	/* 40ms in usecs */
293 static int32_t rack_slot_reduction = 4;
294 static int32_t rack_wma_divisor = 8;		/* For WMA calculation */
295 static int32_t rack_cwnd_block_ends_measure = 0;
296 static int32_t rack_rwnd_block_ends_measure = 0;
297 static int32_t rack_def_profile = 0;
298 
299 static int32_t rack_lower_cwnd_at_tlp = 0;
300 static int32_t rack_always_send_oldest = 0;
301 static int32_t rack_tlp_threshold_use = TLP_USE_TWO_ONE;
302 
303 static uint16_t rack_per_of_gp_ss = 250;	/* 250 % slow-start */
304 static uint16_t rack_per_of_gp_ca = 200;	/* 200 % congestion-avoidance */
305 static uint16_t rack_per_of_gp_rec = 200;	/* 200 % of bw */
306 
307 /* Probertt */
308 static uint16_t rack_per_of_gp_probertt = 60;	/* 60% of bw */
309 static uint16_t rack_per_of_gp_lowthresh = 40;	/* 40% is bottom */
310 static uint16_t rack_per_of_gp_probertt_reduce = 10; /* 10% reduction */
311 static uint16_t rack_atexit_prtt_hbp = 130;	/* Clamp to 130% on exit prtt if highly buffered path */
312 static uint16_t rack_atexit_prtt = 130;	/* Clamp to 100% on exit prtt if non highly buffered path */
313 
314 static uint32_t rack_max_drain_wait = 2;	/* How man gp srtt's before we give up draining */
315 static uint32_t rack_must_drain = 1;		/* How many GP srtt's we *must* wait */
316 static uint32_t rack_probertt_use_min_rtt_entry = 1;	/* Use the min to calculate the goal else gp_srtt */
317 static uint32_t rack_probertt_use_min_rtt_exit = 0;
318 static uint32_t rack_probe_rtt_sets_cwnd = 0;
319 static uint32_t rack_probe_rtt_safety_val = 2000000;	/* No more than 2 sec in probe-rtt */
320 static uint32_t rack_time_between_probertt = 9600000;	/* 9.6 sec in usecs */
321 static uint32_t rack_probertt_gpsrtt_cnt_mul = 0;	/* How many srtt periods does probe-rtt last top fraction */
322 static uint32_t rack_probertt_gpsrtt_cnt_div = 0;	/* How many srtt periods does probe-rtt last bottom fraction */
323 static uint32_t rack_min_probertt_hold = 40000;		/* Equal to delayed ack time */
324 static uint32_t rack_probertt_filter_life = 10000000;
325 static uint32_t rack_probertt_lower_within = 10;
326 static uint32_t rack_min_rtt_movement = 250000;	/* Must move at least 250ms (in microseconds)  to count as a lowering */
327 static int32_t rack_pace_one_seg = 0;		/* Shall we pace for less than 1.4Meg 1MSS at a time */
328 static int32_t rack_probertt_clear_is = 1;
329 static int32_t rack_max_drain_hbp = 1;		/* Extra drain times gpsrtt for highly buffered paths */
330 static int32_t rack_hbp_thresh = 3;		/* what is the divisor max_rtt/min_rtt to decided a hbp */
331 
332 /* Part of pacing */
333 static int32_t rack_max_per_above = 30;		/* When we go to increment stop if above 100+this% */
334 
335 /* Timely information:
336  *
337  * Here we have various control parameters on how
338  * timely may change the multiplier. rack_gain_p5_ub
339  * is associated with timely but not directly influencing
340  * the rate decision like the other variables. It controls
341  * the way fill-cw interacts with timely and caps how much
342  * timely can boost the fill-cw b/w.
343  *
344  * The other values are various boost/shrink numbers as well
345  * as potential caps when adjustments are made to the timely
346  * gain (returned by rack_get_output_gain(). Remember too that
347  * the gain returned can be overriden by other factors such as
348  * probeRTT as well as fixed-rate-pacing.
349  */
350 static int32_t rack_gain_p5_ub = 250;
351 static int32_t rack_gp_per_bw_mul_up = 2;	/* 2% */
352 static int32_t rack_gp_per_bw_mul_down = 4;	/* 4% */
353 static int32_t rack_gp_rtt_maxmul = 3;		/* 3 x maxmin */
354 static int32_t rack_gp_rtt_minmul = 1;		/* minrtt + (minrtt/mindiv) is lower rtt */
355 static int32_t rack_gp_rtt_mindiv = 4;		/* minrtt + (minrtt * minmul/mindiv) is lower rtt */
356 static int32_t rack_gp_decrease_per = 80;	/* Beta value of timely decrease (.8) = 80 */
357 static int32_t rack_gp_increase_per = 2;	/* 2% increase in multiplier */
358 static int32_t rack_per_lower_bound = 50;	/* Don't allow to drop below this multiplier */
359 static int32_t rack_per_upper_bound_ss = 0;	/* Don't allow SS to grow above this */
360 static int32_t rack_per_upper_bound_ca = 0;	/* Don't allow CA to grow above this */
361 static int32_t rack_do_dyn_mul = 0;		/* Are the rack gp multipliers dynamic */
362 static int32_t rack_gp_no_rec_chg = 1;		/* Prohibit recovery from reducing it's multiplier */
363 static int32_t rack_timely_dec_clear = 6;	/* Do we clear decrement count at a value (6)? */
364 static int32_t rack_timely_max_push_rise = 3;	/* One round of pushing */
365 static int32_t rack_timely_max_push_drop = 3;	/* Three round of pushing */
366 static int32_t rack_timely_min_segs = 4;	/* 4 segment minimum */
367 static int32_t rack_use_max_for_nobackoff = 0;
368 static int32_t rack_timely_int_timely_only = 0;	/* do interim timely's only use the timely algo (no b/w changes)? */
369 static int32_t rack_timely_no_stopping = 0;
370 static int32_t rack_down_raise_thresh = 100;
371 static int32_t rack_req_segs = 1;
372 static uint64_t rack_bw_rate_cap = 0;
373 static uint64_t rack_fillcw_bw_cap = 3750000;	/* Cap fillcw at 30Mbps */
374 
375 
376 /* Rack specific counters */
377 counter_u64_t rack_saw_enobuf;
378 counter_u64_t rack_saw_enobuf_hw;
379 counter_u64_t rack_saw_enetunreach;
380 counter_u64_t rack_persists_sends;
381 counter_u64_t rack_persists_acks;
382 counter_u64_t rack_persists_loss;
383 counter_u64_t rack_persists_lost_ends;
384 counter_u64_t rack_total_bytes;
385 #ifdef INVARIANTS
386 counter_u64_t rack_adjust_map_bw;
387 #endif
388 /* Tail loss probe counters */
389 counter_u64_t rack_tlp_tot;
390 counter_u64_t rack_tlp_newdata;
391 counter_u64_t rack_tlp_retran;
392 counter_u64_t rack_tlp_retran_bytes;
393 counter_u64_t rack_to_tot;
394 counter_u64_t rack_hot_alloc;
395 counter_u64_t tcp_policer_detected;
396 counter_u64_t rack_to_alloc;
397 counter_u64_t rack_to_alloc_hard;
398 counter_u64_t rack_to_alloc_emerg;
399 counter_u64_t rack_to_alloc_limited;
400 counter_u64_t rack_alloc_limited_conns;
401 counter_u64_t rack_split_limited;
402 counter_u64_t rack_rxt_clamps_cwnd;
403 counter_u64_t rack_rxt_clamps_cwnd_uniq;
404 
405 counter_u64_t rack_multi_single_eq;
406 counter_u64_t rack_proc_non_comp_ack;
407 
408 counter_u64_t rack_fto_send;
409 counter_u64_t rack_fto_rsm_send;
410 counter_u64_t rack_nfto_resend;
411 counter_u64_t rack_non_fto_send;
412 counter_u64_t rack_extended_rfo;
413 
414 counter_u64_t rack_sack_proc_all;
415 counter_u64_t rack_sack_proc_short;
416 counter_u64_t rack_sack_proc_restart;
417 counter_u64_t rack_sack_attacks_detected;
418 counter_u64_t rack_sack_attacks_reversed;
419 counter_u64_t rack_sack_attacks_suspect;
420 counter_u64_t rack_sack_used_next_merge;
421 counter_u64_t rack_sack_splits;
422 counter_u64_t rack_sack_used_prev_merge;
423 counter_u64_t rack_sack_skipped_acked;
424 counter_u64_t rack_ack_total;
425 counter_u64_t rack_express_sack;
426 counter_u64_t rack_sack_total;
427 counter_u64_t rack_move_none;
428 counter_u64_t rack_move_some;
429 
430 counter_u64_t rack_input_idle_reduces;
431 counter_u64_t rack_collapsed_win;
432 counter_u64_t rack_collapsed_win_seen;
433 counter_u64_t rack_collapsed_win_rxt;
434 counter_u64_t rack_collapsed_win_rxt_bytes;
435 counter_u64_t rack_try_scwnd;
436 counter_u64_t rack_hw_pace_init_fail;
437 counter_u64_t rack_hw_pace_lost;
438 
439 counter_u64_t rack_out_size[TCP_MSS_ACCT_SIZE];
440 counter_u64_t rack_opts_arry[RACK_OPTS_SIZE];
441 
442 
443 #define	RACK_REXMTVAL(tp) max(rack_rto_min, ((tp)->t_srtt + ((tp)->t_rttvar << 2)))
444 
445 #define	RACK_TCPT_RANGESET(tv, value, tvmin, tvmax, slop) do {	\
446 	(tv) = (value) + slop;	 \
447 	if ((u_long)(tv) < (u_long)(tvmin)) \
448 		(tv) = (tvmin); \
449 	if ((u_long)(tv) > (u_long)(tvmax)) \
450 		(tv) = (tvmax); \
451 } while (0)
452 
453 static void
454 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick,  int event, int line);
455 
456 static int
457 rack_process_ack(struct mbuf *m, struct tcphdr *th,
458     struct socket *so, struct tcpcb *tp, struct tcpopt *to,
459     uint32_t tiwin, int32_t tlen, int32_t * ofia, int32_t thflags, int32_t * ret_val, int32_t orig_tlen);
460 static int
461 rack_process_data(struct mbuf *m, struct tcphdr *th,
462     struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
463     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt);
464 static void
465 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack,
466    uint32_t th_ack, uint16_t nsegs, uint16_t type, int32_t recovery);
467 static struct rack_sendmap *rack_alloc(struct tcp_rack *rack);
468 static struct rack_sendmap *rack_alloc_limit(struct tcp_rack *rack,
469     uint8_t limit_type);
470 static struct rack_sendmap *
471 rack_check_recovery_mode(struct tcpcb *tp,
472     uint32_t tsused);
473 static uint32_t
474 rack_grab_rtt(struct tcpcb *tp, struct tcp_rack *rack);
475 static void
476 rack_cong_signal(struct tcpcb *tp,
477 		 uint32_t type, uint32_t ack, int );
478 static void rack_counter_destroy(void);
479 static int
480 rack_ctloutput(struct tcpcb *tp, struct sockopt *sopt);
481 static int32_t rack_ctor(void *mem, int32_t size, void *arg, int32_t how);
482 static void
483 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line, uint64_t *fill_override);
484 static void
485 rack_do_segment(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
486     int32_t drop_hdrlen, int32_t tlen, uint8_t iptos);
487 static void rack_dtor(void *mem, int32_t size, void *arg);
488 static void
489 rack_log_alt_to_to_cancel(struct tcp_rack *rack,
490     uint32_t flex1, uint32_t flex2,
491     uint32_t flex3, uint32_t flex4,
492     uint32_t flex5, uint32_t flex6,
493     uint16_t flex7, uint8_t mod);
494 
495 static void
496 rack_log_pacing_delay_calc(struct tcp_rack *rack, uint32_t len, uint32_t slot,
497    uint64_t bw_est, uint64_t bw, uint64_t len_time, int method, int line,
498    struct rack_sendmap *rsm, uint8_t quality);
499 static struct rack_sendmap *
500 rack_find_high_nonack(struct tcp_rack *rack,
501     struct rack_sendmap *rsm);
502 static struct rack_sendmap *rack_find_lowest_rsm(struct tcp_rack *rack);
503 static void rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm);
504 static void rack_fini(struct tcpcb *tp, int32_t tcb_is_purged);
505 static int rack_get_sockopt(struct tcpcb *tp, struct sockopt *sopt);
506 static void
507 rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
508 			    tcp_seq th_ack, int line, uint8_t quality);
509 static void
510 rack_log_type_pacing_sizes(struct tcpcb *tp, struct tcp_rack *rack, uint32_t arg1, uint32_t arg2, uint32_t arg3, uint8_t frm);
511 
512 static uint32_t
513 rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss);
514 static int32_t rack_handoff_ok(struct tcpcb *tp);
515 static int32_t rack_init(struct tcpcb *tp, void **ptr);
516 static void rack_init_sysctls(void);
517 
518 static void
519 rack_log_ack(struct tcpcb *tp, struct tcpopt *to,
520     struct tcphdr *th, int entered_rec, int dup_ack_struck,
521     int *dsack_seen, int *sacks_seen);
522 static void
523 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
524     uint32_t seq_out, uint16_t th_flags, int32_t err, uint64_t ts,
525     struct rack_sendmap *hintrsm, uint32_t add_flags, struct mbuf *s_mb, uint32_t s_moff, int hw_tls, int segsiz);
526 
527 static uint64_t rack_get_gp_est(struct tcp_rack *rack);
528 
529 
530 static void
531 rack_log_sack_passed(struct tcpcb *tp, struct tcp_rack *rack,
532     struct rack_sendmap *rsm, uint32_t cts);
533 static void rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm);
534 static int32_t rack_output(struct tcpcb *tp);
535 
536 static uint32_t
537 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack,
538     struct sackblk *sack, struct tcpopt *to, struct rack_sendmap **prsm,
539     uint32_t cts, uint32_t segsiz);
540 static void rack_post_recovery(struct tcpcb *tp, uint32_t th_seq);
541 static void rack_remxt_tmr(struct tcpcb *tp);
542 static int rack_set_sockopt(struct tcpcb *tp, struct sockopt *sopt);
543 static void rack_set_state(struct tcpcb *tp, struct tcp_rack *rack);
544 static int32_t rack_stopall(struct tcpcb *tp);
545 static void rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line);
546 static uint32_t
547 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
548     struct rack_sendmap *rsm, uint64_t ts, int32_t * lenp, uint32_t add_flag, int segsiz);
549 static void
550 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
551     struct rack_sendmap *rsm, uint64_t ts, uint32_t add_flag, int segsiz);
552 static int
553 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
554     struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack);
555 static int32_t tcp_addrack(module_t mod, int32_t type, void *data);
556 static int
557 rack_do_close_wait(struct mbuf *m, struct tcphdr *th,
558     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
559     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
560 
561 static void
562 rack_peg_rxt(struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t segsiz);
563 
564 static int
565 rack_do_closing(struct mbuf *m, struct tcphdr *th,
566     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
567     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
568 static int
569 rack_do_established(struct mbuf *m, struct tcphdr *th,
570     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
571     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
572 static int
573 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th,
574     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
575     int32_t tlen, uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos);
576 static int
577 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th,
578     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
579     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
580 static int
581 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th,
582     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
583     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
584 static int
585 rack_do_lastack(struct mbuf *m, struct tcphdr *th,
586     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
587     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
588 static int
589 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th,
590     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
591     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
592 static int
593 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th,
594     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
595     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
596 static void rack_chk_req_and_hybrid_on_out(struct tcp_rack *rack, tcp_seq seq, uint32_t len, uint64_t cts);
597 struct rack_sendmap *
598 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack,
599     uint32_t tsused);
600 static void tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt,
601     uint32_t len, uint32_t us_tim, int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt);
602 static void
603      tcp_rack_partialack(struct tcpcb *tp);
604 static int
605 rack_set_profile(struct tcp_rack *rack, int prof);
606 static void
607 rack_apply_deferred_options(struct tcp_rack *rack);
608 
609 int32_t rack_clear_counter=0;
610 
611 static uint64_t
rack_get_lt_bw(struct tcp_rack * rack)612 rack_get_lt_bw(struct tcp_rack *rack)
613 {
614 	struct timeval tv;
615 	uint64_t tim, bytes;
616 
617 	tim = rack->r_ctl.lt_bw_time;
618 	bytes = rack->r_ctl.lt_bw_bytes;
619 	if (rack->lt_bw_up) {
620 		/* Include all the current bytes too */
621 		microuptime(&tv);
622 		bytes += (rack->rc_tp->snd_una - rack->r_ctl.lt_seq);
623 		tim += (tcp_tv_to_lusectick(&tv) - rack->r_ctl.lt_timemark);
624 	}
625 	if ((bytes != 0) && (tim != 0))
626 		return ((bytes * (uint64_t)1000000) / tim);
627 	else
628 		return (0);
629 }
630 
631 static void
rack_swap_beta_values(struct tcp_rack * rack,uint8_t flex8)632 rack_swap_beta_values(struct tcp_rack *rack, uint8_t flex8)
633 {
634 	struct sockopt sopt;
635 	struct cc_newreno_opts opt;
636 	struct newreno old;
637 	struct tcpcb *tp;
638 	int error, failed = 0;
639 
640 	tp = rack->rc_tp;
641 	if (tp->t_cc == NULL) {
642 		/* Tcb is leaving */
643 		return;
644 	}
645 	rack->rc_pacing_cc_set = 1;
646 	if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0) {
647 		/* Not new-reno we can't play games with beta! */
648 		failed = 1;
649 		goto out;
650 
651 	}
652 	if (CC_ALGO(tp)->ctl_output == NULL)  {
653 		/* Huh, not using new-reno so no swaps.? */
654 		failed = 2;
655 		goto out;
656 	}
657 	/* Get the current values out */
658 	sopt.sopt_valsize = sizeof(struct cc_newreno_opts);
659 	sopt.sopt_dir = SOPT_GET;
660 	opt.name = CC_NEWRENO_BETA;
661 	error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
662 	if (error)  {
663 		failed = 3;
664 		goto out;
665 	}
666 	old.beta = opt.val;
667 	opt.name = CC_NEWRENO_BETA_ECN;
668 	error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
669 	if (error)  {
670 		failed = 4;
671 		goto out;
672 	}
673 	old.beta_ecn = opt.val;
674 
675 	/* Now lets set in the values we have stored */
676 	sopt.sopt_dir = SOPT_SET;
677 	opt.name = CC_NEWRENO_BETA;
678 	opt.val = rack->r_ctl.rc_saved_beta.beta;
679 	error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
680 	if (error)  {
681 		failed = 5;
682 		goto out;
683 	}
684 	opt.name = CC_NEWRENO_BETA_ECN;
685 	opt.val = rack->r_ctl.rc_saved_beta.beta_ecn;
686 	error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
687 	if (error) {
688 		failed = 6;
689 		goto out;
690 	}
691 	/* Save off the values for restoral */
692 	memcpy(&rack->r_ctl.rc_saved_beta, &old, sizeof(struct newreno));
693 out:
694 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
695 		union tcp_log_stackspecific log;
696 		struct timeval tv;
697 		struct newreno *ptr;
698 
699 		ptr = ((struct newreno *)tp->t_ccv.cc_data);
700 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
701 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
702 		log.u_bbr.flex1 = ptr->beta;
703 		log.u_bbr.flex2 = ptr->beta_ecn;
704 		log.u_bbr.flex3 = ptr->newreno_flags;
705 		log.u_bbr.flex4 = rack->r_ctl.rc_saved_beta.beta;
706 		log.u_bbr.flex5 = rack->r_ctl.rc_saved_beta.beta_ecn;
707 		log.u_bbr.flex6 = failed;
708 		log.u_bbr.flex7 = rack->gp_ready;
709 		log.u_bbr.flex7 <<= 1;
710 		log.u_bbr.flex7 |= rack->use_fixed_rate;
711 		log.u_bbr.flex7 <<= 1;
712 		log.u_bbr.flex7 |= rack->rc_pacing_cc_set;
713 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
714 		log.u_bbr.flex8 = flex8;
715 		tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, error,
716 			       0, &log, false, NULL, NULL, 0, &tv);
717 	}
718 }
719 
720 static void
rack_set_cc_pacing(struct tcp_rack * rack)721 rack_set_cc_pacing(struct tcp_rack *rack)
722 {
723 	if (rack->rc_pacing_cc_set)
724 		return;
725 	/*
726 	 * Use the swap utility placing in 3 for flex8 to id a
727 	 * set of a new set of values.
728 	 */
729 	rack->rc_pacing_cc_set = 1;
730 	rack_swap_beta_values(rack, 3);
731 }
732 
733 static void
rack_undo_cc_pacing(struct tcp_rack * rack)734 rack_undo_cc_pacing(struct tcp_rack *rack)
735 {
736 	if (rack->rc_pacing_cc_set == 0)
737 		return;
738 	/*
739 	 * Use the swap utility placing in 4 for flex8 to id a
740 	 * restoral of the old values.
741 	 */
742 	rack->rc_pacing_cc_set = 0;
743 	rack_swap_beta_values(rack, 4);
744 }
745 
746 static void
rack_remove_pacing(struct tcp_rack * rack)747 rack_remove_pacing(struct tcp_rack *rack)
748 {
749 	if (rack->rc_pacing_cc_set)
750 		rack_undo_cc_pacing(rack);
751 	if (rack->r_ctl.pacing_method & RACK_REG_PACING)
752 		tcp_decrement_paced_conn();
753 	if (rack->r_ctl.pacing_method & RACK_DGP_PACING)
754 		tcp_dec_dgp_pacing_cnt();
755 	rack->rc_always_pace = 0;
756 	rack->r_ctl.pacing_method = RACK_PACING_NONE;
757 	rack->dgp_on = 0;
758 	rack->rc_hybrid_mode = 0;
759 	rack->use_fixed_rate = 0;
760 }
761 
762 static void
rack_log_gpset(struct tcp_rack * rack,uint32_t seq_end,uint32_t ack_end_t,uint32_t send_end_t,int line,uint8_t mode,struct rack_sendmap * rsm)763 rack_log_gpset(struct tcp_rack *rack, uint32_t seq_end, uint32_t ack_end_t,
764 	       uint32_t send_end_t, int line, uint8_t mode, struct rack_sendmap *rsm)
765 {
766 	if (tcp_bblogging_on(rack->rc_tp) && (rack_verbose_logging != 0)) {
767 		union tcp_log_stackspecific log;
768 		struct timeval tv;
769 
770 		memset(&log, 0, sizeof(log));
771 		log.u_bbr.flex1 = seq_end;
772 		log.u_bbr.flex2 = rack->rc_tp->gput_seq;
773 		log.u_bbr.flex3 = ack_end_t;
774 		log.u_bbr.flex4 = rack->rc_tp->gput_ts;
775 		log.u_bbr.flex5 = send_end_t;
776 		log.u_bbr.flex6 = rack->rc_tp->gput_ack;
777 		log.u_bbr.flex7 = mode;
778 		log.u_bbr.flex8 = 69;
779 		log.u_bbr.rttProp = rack->r_ctl.rc_gp_cumack_ts;
780 		log.u_bbr.delRate = rack->r_ctl.rc_gp_output_ts;
781 		log.u_bbr.pkts_out = line;
782 		log.u_bbr.cwnd_gain = rack->app_limited_needs_set;
783 		log.u_bbr.pkt_epoch = rack->r_ctl.rc_app_limited_cnt;
784 		log.u_bbr.epoch = rack->r_ctl.current_round;
785 		log.u_bbr.lt_epoch = rack->r_ctl.rc_considered_lost;
786 		if (rsm != NULL) {
787 			log.u_bbr.applimited = rsm->r_start;
788 			log.u_bbr.delivered = rsm->r_end;
789 			log.u_bbr.epoch = rsm->r_flags;
790 		}
791 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
792 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
793 		    &rack->rc_inp->inp_socket->so_rcv,
794 		    &rack->rc_inp->inp_socket->so_snd,
795 		    BBR_LOG_HPTSI_CALC, 0,
796 		    0, &log, false, &tv);
797 	}
798 }
799 
800 static int
sysctl_rack_clear(SYSCTL_HANDLER_ARGS)801 sysctl_rack_clear(SYSCTL_HANDLER_ARGS)
802 {
803 	uint32_t stat;
804 	int32_t error;
805 
806 	error = SYSCTL_OUT(req, &rack_clear_counter, sizeof(uint32_t));
807 	if (error || req->newptr == NULL)
808 		return error;
809 
810 	error = SYSCTL_IN(req, &stat, sizeof(uint32_t));
811 	if (error)
812 		return (error);
813 	if (stat == 1) {
814 #ifdef INVARIANTS
815 		printf("Clearing RACK counters\n");
816 #endif
817 		counter_u64_zero(rack_tlp_tot);
818 		counter_u64_zero(rack_tlp_newdata);
819 		counter_u64_zero(rack_tlp_retran);
820 		counter_u64_zero(rack_tlp_retran_bytes);
821 		counter_u64_zero(rack_to_tot);
822 		counter_u64_zero(rack_saw_enobuf);
823 		counter_u64_zero(rack_saw_enobuf_hw);
824 		counter_u64_zero(rack_saw_enetunreach);
825 		counter_u64_zero(rack_persists_sends);
826 		counter_u64_zero(rack_total_bytes);
827 		counter_u64_zero(rack_persists_acks);
828 		counter_u64_zero(rack_persists_loss);
829 		counter_u64_zero(rack_persists_lost_ends);
830 #ifdef INVARIANTS
831 		counter_u64_zero(rack_adjust_map_bw);
832 #endif
833 		counter_u64_zero(rack_to_alloc_hard);
834 		counter_u64_zero(rack_to_alloc_emerg);
835 		counter_u64_zero(rack_sack_proc_all);
836 		counter_u64_zero(rack_fto_send);
837 		counter_u64_zero(rack_fto_rsm_send);
838 		counter_u64_zero(rack_extended_rfo);
839 		counter_u64_zero(rack_hw_pace_init_fail);
840 		counter_u64_zero(rack_hw_pace_lost);
841 		counter_u64_zero(rack_non_fto_send);
842 		counter_u64_zero(rack_nfto_resend);
843 		counter_u64_zero(rack_sack_proc_short);
844 		counter_u64_zero(rack_sack_proc_restart);
845 		counter_u64_zero(rack_to_alloc);
846 		counter_u64_zero(rack_to_alloc_limited);
847 		counter_u64_zero(rack_alloc_limited_conns);
848 		counter_u64_zero(rack_split_limited);
849 		counter_u64_zero(rack_rxt_clamps_cwnd);
850 		counter_u64_zero(rack_rxt_clamps_cwnd_uniq);
851 		counter_u64_zero(rack_multi_single_eq);
852 		counter_u64_zero(rack_proc_non_comp_ack);
853 		counter_u64_zero(rack_sack_attacks_detected);
854 		counter_u64_zero(rack_sack_attacks_reversed);
855 		counter_u64_zero(rack_sack_attacks_suspect);
856 		counter_u64_zero(rack_sack_used_next_merge);
857 		counter_u64_zero(rack_sack_used_prev_merge);
858 		counter_u64_zero(rack_sack_splits);
859 		counter_u64_zero(rack_sack_skipped_acked);
860 		counter_u64_zero(rack_ack_total);
861 		counter_u64_zero(rack_express_sack);
862 		counter_u64_zero(rack_sack_total);
863 		counter_u64_zero(rack_move_none);
864 		counter_u64_zero(rack_move_some);
865 		counter_u64_zero(rack_try_scwnd);
866 		counter_u64_zero(rack_collapsed_win);
867 		counter_u64_zero(rack_collapsed_win_rxt);
868 		counter_u64_zero(rack_collapsed_win_seen);
869 		counter_u64_zero(rack_collapsed_win_rxt_bytes);
870 	} else if (stat == 2) {
871 #ifdef INVARIANTS
872 		printf("Clearing RACK option array\n");
873 #endif
874 		COUNTER_ARRAY_ZERO(rack_opts_arry, RACK_OPTS_SIZE);
875 	} else if (stat == 3) {
876 		printf("Rack has no stats counters to clear (use 1 to clear all stats in sysctl node)\n");
877 	} else if (stat == 4) {
878 #ifdef INVARIANTS
879 		printf("Clearing RACK out size array\n");
880 #endif
881 		COUNTER_ARRAY_ZERO(rack_out_size, TCP_MSS_ACCT_SIZE);
882 	}
883 	rack_clear_counter = 0;
884 	return (0);
885 }
886 
887 static void
rack_init_sysctls(void)888 rack_init_sysctls(void)
889 {
890 	struct sysctl_oid *rack_counters;
891 	struct sysctl_oid *rack_attack;
892 	struct sysctl_oid *rack_pacing;
893 	struct sysctl_oid *rack_timely;
894 	struct sysctl_oid *rack_timers;
895 	struct sysctl_oid *rack_tlp;
896 	struct sysctl_oid *rack_misc;
897 	struct sysctl_oid *rack_features;
898 	struct sysctl_oid *rack_measure;
899 	struct sysctl_oid *rack_probertt;
900 	struct sysctl_oid *rack_hw_pacing;
901 	struct sysctl_oid *rack_policing;
902 
903 	rack_attack = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
904 	    SYSCTL_CHILDREN(rack_sysctl_root),
905 	    OID_AUTO,
906 	    "sack_attack",
907 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
908 	    "Rack Sack Attack Counters and Controls");
909 	rack_counters = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
910 	    SYSCTL_CHILDREN(rack_sysctl_root),
911 	    OID_AUTO,
912 	    "stats",
913 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
914 	    "Rack Counters");
915 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
916 	    SYSCTL_CHILDREN(rack_sysctl_root),
917 	    OID_AUTO, "rate_sample_method", CTLFLAG_RW,
918 	    &rack_rate_sample_method , USE_RTT_LOW,
919 	    "What method should we use for rate sampling 0=high, 1=low ");
920 	/* Probe rtt related controls */
921 	rack_probertt = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
922 	    SYSCTL_CHILDREN(rack_sysctl_root),
923 	    OID_AUTO,
924 	    "probertt",
925 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
926 	    "ProbeRTT related Controls");
927 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
928 	    SYSCTL_CHILDREN(rack_probertt),
929 	    OID_AUTO, "exit_per_hpb", CTLFLAG_RW,
930 	    &rack_atexit_prtt_hbp, 130,
931 	    "What percentage above goodput do we clamp CA/SS to at exit on high-BDP path 110%");
932 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
933 	    SYSCTL_CHILDREN(rack_probertt),
934 	    OID_AUTO, "exit_per_nonhpb", CTLFLAG_RW,
935 	    &rack_atexit_prtt, 130,
936 	    "What percentage above goodput do we clamp CA/SS to at exit on a non high-BDP path 100%");
937 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
938 	    SYSCTL_CHILDREN(rack_probertt),
939 	    OID_AUTO, "gp_per_mul", CTLFLAG_RW,
940 	    &rack_per_of_gp_probertt, 60,
941 	    "What percentage of goodput do we pace at in probertt");
942 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
943 	    SYSCTL_CHILDREN(rack_probertt),
944 	    OID_AUTO, "gp_per_reduce", CTLFLAG_RW,
945 	    &rack_per_of_gp_probertt_reduce, 10,
946 	    "What percentage of goodput do we reduce every gp_srtt");
947 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
948 	    SYSCTL_CHILDREN(rack_probertt),
949 	    OID_AUTO, "gp_per_low", CTLFLAG_RW,
950 	    &rack_per_of_gp_lowthresh, 40,
951 	    "What percentage of goodput do we allow the multiplier to fall to");
952 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
953 	    SYSCTL_CHILDREN(rack_probertt),
954 	    OID_AUTO, "time_between", CTLFLAG_RW,
955 	    & rack_time_between_probertt, 96000000,
956 	    "How many useconds between the lowest rtt falling must past before we enter probertt");
957 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
958 	    SYSCTL_CHILDREN(rack_probertt),
959 	    OID_AUTO, "safety", CTLFLAG_RW,
960 	    &rack_probe_rtt_safety_val, 2000000,
961 	    "If not zero, provides a maximum usecond that you can stay in probertt (2sec = 2000000)");
962 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
963 	    SYSCTL_CHILDREN(rack_probertt),
964 	    OID_AUTO, "sets_cwnd", CTLFLAG_RW,
965 	    &rack_probe_rtt_sets_cwnd, 0,
966 	    "Do we set the cwnd too (if always_lower is on)");
967 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
968 	    SYSCTL_CHILDREN(rack_probertt),
969 	    OID_AUTO, "maxdrainsrtts", CTLFLAG_RW,
970 	    &rack_max_drain_wait, 2,
971 	    "Maximum number of gp_srtt's to hold in drain waiting for flight to reach goal");
972 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
973 	    SYSCTL_CHILDREN(rack_probertt),
974 	    OID_AUTO, "mustdrainsrtts", CTLFLAG_RW,
975 	    &rack_must_drain, 1,
976 	    "We must drain this many gp_srtt's waiting for flight to reach goal");
977 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
978 	    SYSCTL_CHILDREN(rack_probertt),
979 	    OID_AUTO, "goal_use_min_entry", CTLFLAG_RW,
980 	    &rack_probertt_use_min_rtt_entry, 1,
981 	    "Should we use the min-rtt to calculate the goal rtt (else gp_srtt) at entry");
982 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
983 	    SYSCTL_CHILDREN(rack_probertt),
984 	    OID_AUTO, "goal_use_min_exit", CTLFLAG_RW,
985 	    &rack_probertt_use_min_rtt_exit, 0,
986 	    "How to set cwnd at exit, 0 - dynamic, 1 - use min-rtt, 2 - use curgprtt, 3 - entry gp-rtt");
987 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
988 	    SYSCTL_CHILDREN(rack_probertt),
989 	    OID_AUTO, "length_div", CTLFLAG_RW,
990 	    &rack_probertt_gpsrtt_cnt_div, 0,
991 	    "How many recent goodput srtt periods plus hold tim does probertt last (bottom of fraction)");
992 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
993 	    SYSCTL_CHILDREN(rack_probertt),
994 	    OID_AUTO, "length_mul", CTLFLAG_RW,
995 	    &rack_probertt_gpsrtt_cnt_mul, 0,
996 	    "How many recent goodput srtt periods plus hold tim does probertt last (top of fraction)");
997 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
998 	    SYSCTL_CHILDREN(rack_probertt),
999 	    OID_AUTO, "holdtim_at_target", CTLFLAG_RW,
1000 	    &rack_min_probertt_hold, 200000,
1001 	    "What is the minimum time we hold probertt at target");
1002 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1003 	    SYSCTL_CHILDREN(rack_probertt),
1004 	    OID_AUTO, "filter_life", CTLFLAG_RW,
1005 	    &rack_probertt_filter_life, 10000000,
1006 	    "What is the time for the filters life in useconds");
1007 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1008 	    SYSCTL_CHILDREN(rack_probertt),
1009 	    OID_AUTO, "lower_within", CTLFLAG_RW,
1010 	    &rack_probertt_lower_within, 10,
1011 	    "If the rtt goes lower within this percentage of the time, go into probe-rtt");
1012 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1013 	    SYSCTL_CHILDREN(rack_probertt),
1014 	    OID_AUTO, "must_move", CTLFLAG_RW,
1015 	    &rack_min_rtt_movement, 250,
1016 	    "How much is the minimum movement in rtt to count as a drop for probertt purposes");
1017 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1018 	    SYSCTL_CHILDREN(rack_probertt),
1019 	    OID_AUTO, "clear_is_cnts", CTLFLAG_RW,
1020 	    &rack_probertt_clear_is, 1,
1021 	    "Do we clear I/S counts on exiting probe-rtt");
1022 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1023 	    SYSCTL_CHILDREN(rack_probertt),
1024 	    OID_AUTO, "hbp_extra_drain", CTLFLAG_RW,
1025 	    &rack_max_drain_hbp, 1,
1026 	    "How many extra drain gpsrtt's do we get in highly buffered paths");
1027 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1028 	    SYSCTL_CHILDREN(rack_probertt),
1029 	    OID_AUTO, "hbp_threshold", CTLFLAG_RW,
1030 	    &rack_hbp_thresh, 3,
1031 	    "We are highly buffered if min_rtt_seen / max_rtt_seen > this-threshold");
1032 	/* Pacing related sysctls */
1033 	rack_pacing = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1034 	    SYSCTL_CHILDREN(rack_sysctl_root),
1035 	    OID_AUTO,
1036 	    "pacing",
1037 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1038 	    "Pacing related Controls");
1039 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1040 	    SYSCTL_CHILDREN(rack_pacing),
1041 	    OID_AUTO, "pcm_enabled", CTLFLAG_RW,
1042 	    &rack_pcm_is_enabled, 1,
1043 	    "Do we by default do PCM measurements?");
1044 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1045 	    SYSCTL_CHILDREN(rack_pacing),
1046 	    OID_AUTO, "pcm_rnds", CTLFLAG_RW,
1047 	    &rack_pcm_every_n_rounds, 100,
1048 	    "How many rounds before we need to do a PCM measurement");
1049 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1050 	    SYSCTL_CHILDREN(rack_pacing),
1051 	    OID_AUTO, "pcm_blast", CTLFLAG_RW,
1052 	    &rack_pcm_blast, 0,
1053 	    "Blast out the full cwnd/rwnd when doing a PCM measurement");
1054 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1055 	    SYSCTL_CHILDREN(rack_pacing),
1056 	    OID_AUTO, "rnd_gp_gain", CTLFLAG_RW,
1057 	    &rack_gp_gain_req, 1200,
1058 	    "How much do we have to increase the GP to record the round 1200 = 120.0");
1059 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1060 	    SYSCTL_CHILDREN(rack_pacing),
1061 	    OID_AUTO, "dgp_out_of_ss_at", CTLFLAG_RW,
1062 	    &rack_rnd_cnt_req, 0x10005,
1063 	    "How many rounds less than rnd_gp_gain will drop us out of SS");
1064 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1065 	    SYSCTL_CHILDREN(rack_pacing),
1066 	    OID_AUTO, "no_timely", CTLFLAG_RW,
1067 	    &rack_timely_off, 0,
1068 	    "Do we not use timely in DGP?");
1069 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1070 	    SYSCTL_CHILDREN(rack_pacing),
1071 	    OID_AUTO, "fullbufdisc", CTLFLAG_RW,
1072 	    &rack_full_buffer_discount, 10,
1073 	    "What percentage b/w reduction over the GP estimate for a full buffer (default=0 off)?");
1074 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1075 	    SYSCTL_CHILDREN(rack_pacing),
1076 	    OID_AUTO, "fillcw", CTLFLAG_RW,
1077 	    &rack_fill_cw_state, 0,
1078 	    "Enable fillcw on new connections (default=0 off)?");
1079 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1080 	    SYSCTL_CHILDREN(rack_pacing),
1081 	    OID_AUTO, "min_burst", CTLFLAG_RW,
1082 	    &rack_pacing_min_seg, 0,
1083 	    "What is the min burst size for pacing (0 disables)?");
1084 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1085 	    SYSCTL_CHILDREN(rack_pacing),
1086 	    OID_AUTO, "divisor", CTLFLAG_RW,
1087 	    &rack_default_pacing_divisor, 250,
1088 	    "What is the default divisor given to the rl code?");
1089 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1090 	    SYSCTL_CHILDREN(rack_pacing),
1091 	    OID_AUTO, "fillcw_max_mult", CTLFLAG_RW,
1092 	    &rack_bw_multipler, 0,
1093 	    "What is the limit multiplier of the current gp_est that fillcw can increase the b/w too, 200 == 200% (0 = off)?");
1094 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1095 	    SYSCTL_CHILDREN(rack_pacing),
1096 	    OID_AUTO, "max_pace_over", CTLFLAG_RW,
1097 	    &rack_max_per_above, 30,
1098 	    "What is the maximum allowable percentage that we can pace above (so 30 = 130% of our goal)");
1099 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1100 	    SYSCTL_CHILDREN(rack_pacing),
1101 	    OID_AUTO, "allow1mss", CTLFLAG_RW,
1102 	    &rack_pace_one_seg, 0,
1103 	    "Do we allow low b/w pacing of 1MSS instead of two (1.2Meg and less)?");
1104 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1105 	    SYSCTL_CHILDREN(rack_pacing),
1106 	    OID_AUTO, "limit_wsrtt", CTLFLAG_RW,
1107 	    &rack_limit_time_with_srtt, 0,
1108 	    "Do we limit pacing time based on srtt");
1109 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1110 	    SYSCTL_CHILDREN(rack_pacing),
1111 	    OID_AUTO, "gp_per_ss", CTLFLAG_RW,
1112 	    &rack_per_of_gp_ss, 250,
1113 	    "If non zero, what percentage of goodput to pace at in slow start");
1114 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1115 	    SYSCTL_CHILDREN(rack_pacing),
1116 	    OID_AUTO, "gp_per_ca", CTLFLAG_RW,
1117 	    &rack_per_of_gp_ca, 150,
1118 	    "If non zero, what percentage of goodput to pace at in congestion avoidance");
1119 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1120 	    SYSCTL_CHILDREN(rack_pacing),
1121 	    OID_AUTO, "gp_per_rec", CTLFLAG_RW,
1122 	    &rack_per_of_gp_rec, 200,
1123 	    "If non zero, what percentage of goodput to pace at in recovery");
1124 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1125 	    SYSCTL_CHILDREN(rack_pacing),
1126 	    OID_AUTO, "pace_max_seg", CTLFLAG_RW,
1127 	    &rack_hptsi_segments, 40,
1128 	    "What size is the max for TSO segments in pacing and burst mitigation");
1129 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1130 	    SYSCTL_CHILDREN(rack_pacing),
1131 	    OID_AUTO, "burst_reduces", CTLFLAG_RW,
1132 	    &rack_slot_reduction, 4,
1133 	    "When doing only burst mitigation what is the reduce divisor");
1134 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1135 	    SYSCTL_CHILDREN(rack_sysctl_root),
1136 	    OID_AUTO, "use_pacing", CTLFLAG_RW,
1137 	    &rack_pace_every_seg, 0,
1138 	    "If set we use pacing, if clear we use only the original burst mitigation");
1139 	SYSCTL_ADD_U64(&rack_sysctl_ctx,
1140 	    SYSCTL_CHILDREN(rack_pacing),
1141 	    OID_AUTO, "rate_cap", CTLFLAG_RW,
1142 	    &rack_bw_rate_cap, 0,
1143 	    "If set we apply this value to the absolute rate cap used by pacing");
1144 	SYSCTL_ADD_U64(&rack_sysctl_ctx,
1145 	    SYSCTL_CHILDREN(rack_pacing),
1146 	    OID_AUTO, "fillcw_cap", CTLFLAG_RW,
1147 	    &rack_fillcw_bw_cap, 3750000,
1148 	    "Do we have an absolute cap on the amount of b/w fillcw can specify (0 = no)?");
1149 	SYSCTL_ADD_U8(&rack_sysctl_ctx,
1150 	    SYSCTL_CHILDREN(rack_sysctl_root),
1151 	    OID_AUTO, "req_measure_cnt", CTLFLAG_RW,
1152 	    &rack_req_measurements, 1,
1153 	    "If doing dynamic pacing, how many measurements must be in before we start pacing?");
1154 	/* Hardware pacing */
1155 	rack_hw_pacing = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1156 	    SYSCTL_CHILDREN(rack_sysctl_root),
1157 	    OID_AUTO,
1158 	    "hdwr_pacing",
1159 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1160 	    "Pacing related Controls");
1161 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1162 	    SYSCTL_CHILDREN(rack_hw_pacing),
1163 	    OID_AUTO, "rwnd_factor", CTLFLAG_RW,
1164 	    &rack_hw_rwnd_factor, 2,
1165 	    "How many times does snd_wnd need to be bigger than pace_max_seg so we will hold off and get more acks?");
1166 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1167 	    SYSCTL_CHILDREN(rack_hw_pacing),
1168 	    OID_AUTO, "precheck", CTLFLAG_RW,
1169 	    &rack_hw_check_queue, 0,
1170 	    "Do we always precheck the hdwr pacing queue to avoid ENOBUF's?");
1171 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1172 	    SYSCTL_CHILDREN(rack_hw_pacing),
1173 	    OID_AUTO, "pace_enobuf_mult", CTLFLAG_RW,
1174 	    &rack_enobuf_hw_boost_mult, 0,
1175 	    "By how many time_betweens should we boost the pacing time if we see a ENOBUFS?");
1176 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1177 	    SYSCTL_CHILDREN(rack_hw_pacing),
1178 	    OID_AUTO, "pace_enobuf_max", CTLFLAG_RW,
1179 	    &rack_enobuf_hw_max, 2,
1180 	    "What is the max boost the pacing time if we see a ENOBUFS?");
1181 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1182 	    SYSCTL_CHILDREN(rack_hw_pacing),
1183 	    OID_AUTO, "pace_enobuf_min", CTLFLAG_RW,
1184 	    &rack_enobuf_hw_min, 2,
1185 	    "What is the min boost the pacing time if we see a ENOBUFS?");
1186 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1187 	    SYSCTL_CHILDREN(rack_hw_pacing),
1188 	    OID_AUTO, "enable", CTLFLAG_RW,
1189 	    &rack_enable_hw_pacing, 0,
1190 	    "Should RACK attempt to use hw pacing?");
1191 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1192 	    SYSCTL_CHILDREN(rack_hw_pacing),
1193 	    OID_AUTO, "rate_cap", CTLFLAG_RW,
1194 	    &rack_hw_rate_caps, 0,
1195 	    "Does the highest hardware pacing rate cap the rate we will send at??");
1196 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1197 	    SYSCTL_CHILDREN(rack_hw_pacing),
1198 	    OID_AUTO, "uncap_per", CTLFLAG_RW,
1199 	    &rack_hw_rate_cap_per, 0,
1200 	    "If you go over b/w by this amount you will be uncapped (0 = never)");
1201 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1202 	    SYSCTL_CHILDREN(rack_hw_pacing),
1203 	    OID_AUTO, "rate_min", CTLFLAG_RW,
1204 	    &rack_hw_rate_min, 0,
1205 	    "Do we need a minimum estimate of this many bytes per second in order to engage hw pacing?");
1206 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1207 	    SYSCTL_CHILDREN(rack_hw_pacing),
1208 	    OID_AUTO, "rate_to_low", CTLFLAG_RW,
1209 	    &rack_hw_rate_to_low, 0,
1210 	    "If we fall below this rate, dis-engage hw pacing?");
1211 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1212 	    SYSCTL_CHILDREN(rack_hw_pacing),
1213 	    OID_AUTO, "up_only", CTLFLAG_RW,
1214 	    &rack_hw_up_only, 0,
1215 	    "Do we allow hw pacing to lower the rate selected?");
1216 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1217 	    SYSCTL_CHILDREN(rack_hw_pacing),
1218 	    OID_AUTO, "extra_mss_precise", CTLFLAG_RW,
1219 	    &rack_hw_pace_extra_slots, 0,
1220 	    "If the rates between software and hardware match precisely how many extra time_betweens do we get?");
1221 	rack_timely = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1222 	    SYSCTL_CHILDREN(rack_sysctl_root),
1223 	    OID_AUTO,
1224 	    "timely",
1225 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1226 	    "Rack Timely RTT Controls");
1227 	/* Timely based GP dynmics */
1228 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1229 	    SYSCTL_CHILDREN(rack_timely),
1230 	    OID_AUTO, "upper", CTLFLAG_RW,
1231 	    &rack_gp_per_bw_mul_up, 2,
1232 	    "Rack timely upper range for equal b/w (in percentage)");
1233 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1234 	    SYSCTL_CHILDREN(rack_timely),
1235 	    OID_AUTO, "lower", CTLFLAG_RW,
1236 	    &rack_gp_per_bw_mul_down, 4,
1237 	    "Rack timely lower range for equal b/w (in percentage)");
1238 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1239 	    SYSCTL_CHILDREN(rack_timely),
1240 	    OID_AUTO, "rtt_max_mul", CTLFLAG_RW,
1241 	    &rack_gp_rtt_maxmul, 3,
1242 	    "Rack timely multiplier of lowest rtt for rtt_max");
1243 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1244 	    SYSCTL_CHILDREN(rack_timely),
1245 	    OID_AUTO, "rtt_min_div", CTLFLAG_RW,
1246 	    &rack_gp_rtt_mindiv, 4,
1247 	    "Rack timely divisor used for rtt + (rtt * mul/divisor) for check for lower rtt");
1248 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1249 	    SYSCTL_CHILDREN(rack_timely),
1250 	    OID_AUTO, "rtt_min_mul", CTLFLAG_RW,
1251 	    &rack_gp_rtt_minmul, 1,
1252 	    "Rack timely multiplier used for rtt + (rtt * mul/divisor) for check for lower rtt");
1253 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1254 	    SYSCTL_CHILDREN(rack_timely),
1255 	    OID_AUTO, "decrease", CTLFLAG_RW,
1256 	    &rack_gp_decrease_per, 80,
1257 	    "Rack timely Beta value 80 = .8 (scaled by 100)");
1258 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1259 	    SYSCTL_CHILDREN(rack_timely),
1260 	    OID_AUTO, "increase", CTLFLAG_RW,
1261 	    &rack_gp_increase_per, 2,
1262 	    "Rack timely increase perentage of our GP multiplication factor");
1263 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1264 	    SYSCTL_CHILDREN(rack_timely),
1265 	    OID_AUTO, "lowerbound", CTLFLAG_RW,
1266 	    &rack_per_lower_bound, 50,
1267 	    "Rack timely lowest percentage we allow GP multiplier to fall to");
1268 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1269 	    SYSCTL_CHILDREN(rack_timely),
1270 	    OID_AUTO, "p5_upper", CTLFLAG_RW,
1271 	    &rack_gain_p5_ub, 250,
1272 	    "Profile 5 upper bound to timely gain");
1273 
1274 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1275 	    SYSCTL_CHILDREN(rack_timely),
1276 	    OID_AUTO, "upperboundss", CTLFLAG_RW,
1277 	    &rack_per_upper_bound_ss, 0,
1278 	    "Rack timely highest percentage we allow GP multiplier in SS to raise to (0 is no upperbound)");
1279 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1280 	    SYSCTL_CHILDREN(rack_timely),
1281 	    OID_AUTO, "upperboundca", CTLFLAG_RW,
1282 	    &rack_per_upper_bound_ca, 0,
1283 	    "Rack timely highest percentage we allow GP multiplier to CA raise to (0 is no upperbound)");
1284 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1285 	    SYSCTL_CHILDREN(rack_timely),
1286 	    OID_AUTO, "dynamicgp", CTLFLAG_RW,
1287 	    &rack_do_dyn_mul, 0,
1288 	    "Rack timely do we enable dynmaic timely goodput by default");
1289 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1290 	    SYSCTL_CHILDREN(rack_timely),
1291 	    OID_AUTO, "no_rec_red", CTLFLAG_RW,
1292 	    &rack_gp_no_rec_chg, 1,
1293 	    "Rack timely do we prohibit the recovery multiplier from being lowered");
1294 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1295 	    SYSCTL_CHILDREN(rack_timely),
1296 	    OID_AUTO, "red_clear_cnt", CTLFLAG_RW,
1297 	    &rack_timely_dec_clear, 6,
1298 	    "Rack timely what threshold do we count to before another boost during b/w decent");
1299 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1300 	    SYSCTL_CHILDREN(rack_timely),
1301 	    OID_AUTO, "max_push_rise", CTLFLAG_RW,
1302 	    &rack_timely_max_push_rise, 3,
1303 	    "Rack timely how many times do we push up with b/w increase");
1304 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1305 	    SYSCTL_CHILDREN(rack_timely),
1306 	    OID_AUTO, "max_push_drop", CTLFLAG_RW,
1307 	    &rack_timely_max_push_drop, 3,
1308 	    "Rack timely how many times do we push back on b/w decent");
1309 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1310 	    SYSCTL_CHILDREN(rack_timely),
1311 	    OID_AUTO, "min_segs", CTLFLAG_RW,
1312 	    &rack_timely_min_segs, 4,
1313 	    "Rack timely when setting the cwnd what is the min num segments");
1314 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1315 	    SYSCTL_CHILDREN(rack_timely),
1316 	    OID_AUTO, "noback_max", CTLFLAG_RW,
1317 	    &rack_use_max_for_nobackoff, 0,
1318 	    "Rack timely when deciding if to backoff on a loss, do we use under max rtt else min");
1319 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1320 	    SYSCTL_CHILDREN(rack_timely),
1321 	    OID_AUTO, "interim_timely_only", CTLFLAG_RW,
1322 	    &rack_timely_int_timely_only, 0,
1323 	    "Rack timely when doing interim timely's do we only do timely (no b/w consideration)");
1324 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1325 	    SYSCTL_CHILDREN(rack_timely),
1326 	    OID_AUTO, "nonstop", CTLFLAG_RW,
1327 	    &rack_timely_no_stopping, 0,
1328 	    "Rack timely don't stop increase");
1329 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1330 	    SYSCTL_CHILDREN(rack_timely),
1331 	    OID_AUTO, "dec_raise_thresh", CTLFLAG_RW,
1332 	    &rack_down_raise_thresh, 100,
1333 	    "If the CA or SS is below this threshold raise on the first 3 b/w lowers (0=always)");
1334 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1335 	    SYSCTL_CHILDREN(rack_timely),
1336 	    OID_AUTO, "bottom_drag_segs", CTLFLAG_RW,
1337 	    &rack_req_segs, 1,
1338 	    "Bottom dragging if not these many segments outstanding and room");
1339 
1340 	/* TLP and Rack related parameters */
1341 	rack_tlp = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1342 	    SYSCTL_CHILDREN(rack_sysctl_root),
1343 	    OID_AUTO,
1344 	    "tlp",
1345 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1346 	    "TLP and Rack related Controls");
1347 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1348 	    SYSCTL_CHILDREN(rack_tlp),
1349 	    OID_AUTO, "use_rrr", CTLFLAG_RW,
1350 	    &use_rack_rr, 1,
1351 	    "Do we use Rack Rapid Recovery");
1352 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1353 	    SYSCTL_CHILDREN(rack_tlp),
1354 	    OID_AUTO, "post_rec_labc", CTLFLAG_RW,
1355 	    &rack_max_abc_post_recovery, 2,
1356 	    "Since we do early recovery, do we override the l_abc to a value, if so what?");
1357 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1358 	    SYSCTL_CHILDREN(rack_tlp),
1359 	    OID_AUTO, "nonrxt_use_cr", CTLFLAG_RW,
1360 	    &rack_non_rxt_use_cr, 0,
1361 	    "Do we use ss/ca rate if in recovery we are transmitting a new data chunk");
1362 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1363 	    SYSCTL_CHILDREN(rack_tlp),
1364 	    OID_AUTO, "tlpmethod", CTLFLAG_RW,
1365 	    &rack_tlp_threshold_use, TLP_USE_TWO_ONE,
1366 	    "What method do we do for TLP time calc 0=no-de-ack-comp, 1=ID, 2=2.1, 3=2.2");
1367 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1368 	    SYSCTL_CHILDREN(rack_tlp),
1369 	    OID_AUTO, "limit", CTLFLAG_RW,
1370 	    &rack_tlp_limit, 2,
1371 	    "How many TLP's can be sent without sending new data");
1372 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1373 	    SYSCTL_CHILDREN(rack_tlp),
1374 	    OID_AUTO, "use_greater", CTLFLAG_RW,
1375 	    &rack_tlp_use_greater, 1,
1376 	    "Should we use the rack_rtt time if its greater than srtt");
1377 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1378 	    SYSCTL_CHILDREN(rack_tlp),
1379 	    OID_AUTO, "tlpminto", CTLFLAG_RW,
1380 	    &rack_tlp_min, 10000,
1381 	    "TLP minimum timeout per the specification (in microseconds)");
1382 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1383 	    SYSCTL_CHILDREN(rack_tlp),
1384 	    OID_AUTO, "send_oldest", CTLFLAG_RW,
1385 	    &rack_always_send_oldest, 0,
1386 	    "Should we always send the oldest TLP and RACK-TLP");
1387 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1388 	    SYSCTL_CHILDREN(rack_tlp),
1389 	    OID_AUTO, "tlp_cwnd_flag", CTLFLAG_RW,
1390 	    &rack_lower_cwnd_at_tlp, 0,
1391 	    "When a TLP completes a retran should we enter recovery");
1392 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1393 	    SYSCTL_CHILDREN(rack_tlp),
1394 	    OID_AUTO, "reorder_thresh", CTLFLAG_RW,
1395 	    &rack_reorder_thresh, 2,
1396 	    "What factor for rack will be added when seeing reordering (shift right)");
1397 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1398 	    SYSCTL_CHILDREN(rack_tlp),
1399 	    OID_AUTO, "rtt_tlp_thresh", CTLFLAG_RW,
1400 	    &rack_tlp_thresh, 1,
1401 	    "What divisor for TLP rtt/retran will be added (1=rtt, 2=1/2 rtt etc)");
1402 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1403 	    SYSCTL_CHILDREN(rack_tlp),
1404 	    OID_AUTO, "reorder_fade", CTLFLAG_RW,
1405 	    &rack_reorder_fade, 60000000,
1406 	    "Does reorder detection fade, if so how many microseconds (0 means never)");
1407 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1408 	    SYSCTL_CHILDREN(rack_tlp),
1409 	    OID_AUTO, "pktdelay", CTLFLAG_RW,
1410 	    &rack_pkt_delay, 1000,
1411 	    "Extra RACK time (in microseconds) besides reordering thresh");
1412 
1413 	/* Timer related controls */
1414 	rack_timers = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1415 	    SYSCTL_CHILDREN(rack_sysctl_root),
1416 	    OID_AUTO,
1417 	    "timers",
1418 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1419 	    "Timer related controls");
1420 	SYSCTL_ADD_U8(&rack_sysctl_ctx,
1421 	    SYSCTL_CHILDREN(rack_timers),
1422 	    OID_AUTO, "reset_ssth_rec_rto", CTLFLAG_RW,
1423 	    &rack_ssthresh_rest_rto_rec, 0,
1424 	    "When doing recovery -> rto -> recovery do we reset SSthresh?");
1425 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1426 	    SYSCTL_CHILDREN(rack_timers),
1427 	    OID_AUTO, "scoreboard_thresh", CTLFLAG_RW,
1428 	    &rack_rxt_scoreboard_clear_thresh, 2,
1429 	    "How many RTO's are allowed before we clear the scoreboard");
1430 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1431 	    SYSCTL_CHILDREN(rack_timers),
1432 	    OID_AUTO, "honor_hpts_min", CTLFLAG_RW,
1433 	    &rack_honors_hpts_min_to, 1,
1434 	    "Do rack pacing timers honor hpts min timeout");
1435 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1436 	    SYSCTL_CHILDREN(rack_timers),
1437 	    OID_AUTO, "hpts_max_reduce", CTLFLAG_RW,
1438 	    &rack_max_reduce, 10,
1439 	    "Max percentage we will reduce slot by for pacing when we are behind");
1440 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1441 	    SYSCTL_CHILDREN(rack_timers),
1442 	    OID_AUTO, "persmin", CTLFLAG_RW,
1443 	    &rack_persist_min, 250000,
1444 	    "What is the minimum time in microseconds between persists");
1445 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1446 	    SYSCTL_CHILDREN(rack_timers),
1447 	    OID_AUTO, "persmax", CTLFLAG_RW,
1448 	    &rack_persist_max, 2000000,
1449 	    "What is the largest delay in microseconds between persists");
1450 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1451 	    SYSCTL_CHILDREN(rack_timers),
1452 	    OID_AUTO, "delayed_ack", CTLFLAG_RW,
1453 	    &rack_delayed_ack_time, 40000,
1454 	    "Delayed ack time (40ms in microseconds)");
1455 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1456 	    SYSCTL_CHILDREN(rack_timers),
1457 	    OID_AUTO, "minrto", CTLFLAG_RW,
1458 	    &rack_rto_min, 30000,
1459 	    "Minimum RTO in microseconds -- set with caution below 1000 due to TLP");
1460 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1461 	    SYSCTL_CHILDREN(rack_timers),
1462 	    OID_AUTO, "maxrto", CTLFLAG_RW,
1463 	    &rack_rto_max, 4000000,
1464 	    "Maximum RTO in microseconds -- should be at least as large as min_rto");
1465 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1466 	    SYSCTL_CHILDREN(rack_timers),
1467 	    OID_AUTO, "minto", CTLFLAG_RW,
1468 	    &rack_min_to, 1000,
1469 	    "Minimum rack timeout in microseconds");
1470 	/* Measure controls */
1471 	rack_measure = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1472 	    SYSCTL_CHILDREN(rack_sysctl_root),
1473 	    OID_AUTO,
1474 	    "measure",
1475 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1476 	    "Measure related controls");
1477 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1478 	    SYSCTL_CHILDREN(rack_measure),
1479 	    OID_AUTO, "wma_divisor", CTLFLAG_RW,
1480 	    &rack_wma_divisor, 8,
1481 	    "When doing b/w calculation what is the  divisor for the WMA");
1482 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1483 	    SYSCTL_CHILDREN(rack_measure),
1484 	    OID_AUTO, "end_cwnd", CTLFLAG_RW,
1485 	    &rack_cwnd_block_ends_measure, 0,
1486 	    "Does a cwnd just-return end the measurement window (app limited)");
1487 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1488 	    SYSCTL_CHILDREN(rack_measure),
1489 	    OID_AUTO, "end_rwnd", CTLFLAG_RW,
1490 	    &rack_rwnd_block_ends_measure, 0,
1491 	    "Does an rwnd just-return end the measurement window (app limited -- not persists)");
1492 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1493 	    SYSCTL_CHILDREN(rack_measure),
1494 	    OID_AUTO, "min_target", CTLFLAG_RW,
1495 	    &rack_def_data_window, 20,
1496 	    "What is the minimum target window (in mss) for a GP measurements");
1497 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1498 	    SYSCTL_CHILDREN(rack_measure),
1499 	    OID_AUTO, "goal_bdp", CTLFLAG_RW,
1500 	    &rack_goal_bdp, 2,
1501 	    "What is the goal BDP to measure");
1502 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1503 	    SYSCTL_CHILDREN(rack_measure),
1504 	    OID_AUTO, "min_srtts", CTLFLAG_RW,
1505 	    &rack_min_srtts, 1,
1506 	    "What is the goal BDP to measure");
1507 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1508 	    SYSCTL_CHILDREN(rack_measure),
1509 	    OID_AUTO, "min_measure_tim", CTLFLAG_RW,
1510 	    &rack_min_measure_usec, 0,
1511 	    "What is the Minimum time time for a measurement if 0, this is off");
1512 	/* Features */
1513 	rack_features = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1514 	    SYSCTL_CHILDREN(rack_sysctl_root),
1515 	    OID_AUTO,
1516 	    "features",
1517 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1518 	    "Feature controls");
1519 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1520 	    SYSCTL_CHILDREN(rack_features),
1521 	    OID_AUTO, "hybrid_set_maxseg", CTLFLAG_RW,
1522 	    &rack_hybrid_allow_set_maxseg, 0,
1523 	    "Should hybrid pacing allow the setmss command");
1524 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1525 	    SYSCTL_CHILDREN(rack_features),
1526 	    OID_AUTO, "cmpack", CTLFLAG_RW,
1527 	    &rack_use_cmp_acks, 1,
1528 	    "Should RACK have LRO send compressed acks");
1529 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1530 	    SYSCTL_CHILDREN(rack_features),
1531 	    OID_AUTO, "fsb", CTLFLAG_RW,
1532 	    &rack_use_fsb, 1,
1533 	    "Should RACK use the fast send block?");
1534 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1535 	    SYSCTL_CHILDREN(rack_features),
1536 	    OID_AUTO, "rfo", CTLFLAG_RW,
1537 	    &rack_use_rfo, 1,
1538 	    "Should RACK use rack_fast_output()?");
1539 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1540 	    SYSCTL_CHILDREN(rack_features),
1541 	    OID_AUTO, "rsmrfo", CTLFLAG_RW,
1542 	    &rack_use_rsm_rfo, 1,
1543 	    "Should RACK use rack_fast_rsm_output()?");
1544 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1545 	    SYSCTL_CHILDREN(rack_features),
1546 	    OID_AUTO, "non_paced_lro_queue", CTLFLAG_RW,
1547 	    &rack_enable_mqueue_for_nonpaced, 0,
1548 	    "Should RACK use mbuf queuing for non-paced connections");
1549 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1550 	    SYSCTL_CHILDREN(rack_features),
1551 	    OID_AUTO, "hystartplusplus", CTLFLAG_RW,
1552 	    &rack_do_hystart, 0,
1553 	    "Should RACK enable HyStart++ on connections?");
1554 	/* Policer detection */
1555 	rack_policing = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1556 	    SYSCTL_CHILDREN(rack_sysctl_root),
1557 	    OID_AUTO,
1558 	    "policing",
1559 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1560 	    "policer detection");
1561 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1562 	    SYSCTL_CHILDREN(rack_policing),
1563 	    OID_AUTO, "rxt_thresh", CTLFLAG_RW,
1564 	    &rack_policer_rxt_thresh, 0,
1565 	   "Percentage of retransmits we need to be a possible policer (499 = 49.9 percent)");
1566 	SYSCTL_ADD_U8(&rack_sysctl_ctx,
1567 	    SYSCTL_CHILDREN(rack_policing),
1568 	    OID_AUTO, "avg_thresh", CTLFLAG_RW,
1569 	    &rack_policer_avg_thresh, 0,
1570 	    "What threshold of average retransmits needed to recover a lost packet (1 - 169 aka 21 = 2.1)?");
1571 	SYSCTL_ADD_U8(&rack_sysctl_ctx,
1572 	    SYSCTL_CHILDREN(rack_policing),
1573 	    OID_AUTO, "med_thresh", CTLFLAG_RW,
1574 	    &rack_policer_med_thresh, 0,
1575 	    "What threshold of Median retransmits needed to recover a lost packet (1 - 16)?");
1576 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1577 	    SYSCTL_CHILDREN(rack_policing),
1578 	    OID_AUTO, "data_thresh", CTLFLAG_RW,
1579 	    &rack_policer_data_thresh, 64000,
1580 	    "How many bytes must have gotten through before we can start doing policer detection?");
1581 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1582 	    SYSCTL_CHILDREN(rack_policing),
1583 	    OID_AUTO, "bwcomp", CTLFLAG_RW,
1584 	    &rack_policing_do_bw_comp, 1,
1585 	    "Do we raise up low b/w so that at least pace_max_seg can be sent in the srtt?");
1586 	SYSCTL_ADD_U8(&rack_sysctl_ctx,
1587 	    SYSCTL_CHILDREN(rack_policing),
1588 	    OID_AUTO, "recmss", CTLFLAG_RW,
1589 	    &rack_req_del_mss, 18,
1590 	    "How many MSS must be delivered during recovery to engage policer detection?");
1591 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1592 	    SYSCTL_CHILDREN(rack_policing),
1593 	    OID_AUTO, "res_div", CTLFLAG_RW,
1594 	    &rack_policer_bucket_reserve, 20,
1595 	    "What percentage is reserved in the policer bucket?");
1596 	SYSCTL_ADD_U64(&rack_sysctl_ctx,
1597 	    SYSCTL_CHILDREN(rack_policing),
1598 	    OID_AUTO, "min_comp_bw", CTLFLAG_RW,
1599 	    &rack_pol_min_bw, 125000,
1600 	    "Do we have a min b/w for b/w compensation (0 = no)?");
1601 	/* Misc rack controls */
1602 	rack_misc = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1603 	    SYSCTL_CHILDREN(rack_sysctl_root),
1604 	    OID_AUTO,
1605 	    "misc",
1606 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1607 	    "Misc related controls");
1608 #ifdef TCP_ACCOUNTING
1609 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1610 	    SYSCTL_CHILDREN(rack_misc),
1611 	    OID_AUTO, "tcp_acct", CTLFLAG_RW,
1612 	    &rack_tcp_accounting, 0,
1613 	    "Should we turn on TCP accounting for all rack sessions?");
1614 #endif
1615 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1616 	    SYSCTL_CHILDREN(rack_misc),
1617 	    OID_AUTO, "dnd", CTLFLAG_RW,
1618 	    &rack_dnd_default, 0,
1619 	    "Do not disturb default for rack_rrr = 3");
1620 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1621 	    SYSCTL_CHILDREN(rack_misc),
1622 	    OID_AUTO, "sad_seg_per", CTLFLAG_RW,
1623 	    &sad_seg_size_per, 800,
1624 	    "Percentage of segment size needed in a sack 800 = 80.0?");
1625 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1626 	    SYSCTL_CHILDREN(rack_misc),
1627 	    OID_AUTO, "rxt_controls", CTLFLAG_RW,
1628 	    &rack_rxt_controls, 0,
1629 	    "Retransmit sending size controls (valid  values 0, 1, 2 default=1)?");
1630 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1631 	    SYSCTL_CHILDREN(rack_misc),
1632 	    OID_AUTO, "rack_hibeta", CTLFLAG_RW,
1633 	    &rack_hibeta_setting, 0,
1634 	    "Do we ue a high beta (80 instead of 50)?");
1635 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1636 	    SYSCTL_CHILDREN(rack_misc),
1637 	    OID_AUTO, "apply_rtt_with_low_conf", CTLFLAG_RW,
1638 	    &rack_apply_rtt_with_reduced_conf, 0,
1639 	    "When a persist or keep-alive probe is not answered do we calculate rtt on subsequent answers?");
1640 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1641 	    SYSCTL_CHILDREN(rack_misc),
1642 	    OID_AUTO, "rack_dsack_ctl", CTLFLAG_RW,
1643 	    &rack_dsack_std_based, 3,
1644 	    "How do we process dsack with respect to rack timers, bit field, 3 is standards based?");
1645 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1646 	    SYSCTL_CHILDREN(rack_misc),
1647 	    OID_AUTO, "prr_addback_max", CTLFLAG_RW,
1648 	    &rack_prr_addbackmax, 2,
1649 	    "What is the maximum number of MSS we allow to be added back if prr can't send all its data?");
1650 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1651 	    SYSCTL_CHILDREN(rack_misc),
1652 	    OID_AUTO, "stats_gets_ms", CTLFLAG_RW,
1653 	    &rack_stats_gets_ms_rtt, 1,
1654 	    "What do we feed the stats framework (1 = ms_rtt, 0 = us_rtt, 2 = ms_rtt from hdwr, > 2 usec rtt from hdwr)?");
1655 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1656 	    SYSCTL_CHILDREN(rack_misc),
1657 	    OID_AUTO, "clientlowbuf", CTLFLAG_RW,
1658 	    &rack_client_low_buf, 0,
1659 	    "Client low buffer level (below this we are more aggressive in DGP exiting recovery (0 = off)?");
1660 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1661 	    SYSCTL_CHILDREN(rack_misc),
1662 	    OID_AUTO, "defprofile", CTLFLAG_RW,
1663 	    &rack_def_profile, 0,
1664 	    "Should RACK use a default profile (0=no, num == profile num)?");
1665 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1666 	    SYSCTL_CHILDREN(rack_misc),
1667 	    OID_AUTO, "shared_cwnd", CTLFLAG_RW,
1668 	    &rack_enable_shared_cwnd, 1,
1669 	    "Should RACK try to use the shared cwnd on connections where allowed");
1670 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1671 	    SYSCTL_CHILDREN(rack_misc),
1672 	    OID_AUTO, "limits_on_scwnd", CTLFLAG_RW,
1673 	    &rack_limits_scwnd, 1,
1674 	    "Should RACK place low end time limits on the shared cwnd feature");
1675 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1676 	    SYSCTL_CHILDREN(rack_misc),
1677 	    OID_AUTO, "no_prr", CTLFLAG_RW,
1678 	    &rack_disable_prr, 0,
1679 	    "Should RACK not use prr and only pace (must have pacing on)");
1680 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1681 	    SYSCTL_CHILDREN(rack_misc),
1682 	    OID_AUTO, "bb_verbose", CTLFLAG_RW,
1683 	    &rack_verbose_logging, 0,
1684 	    "Should RACK black box logging be verbose");
1685 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1686 	    SYSCTL_CHILDREN(rack_misc),
1687 	    OID_AUTO, "data_after_close", CTLFLAG_RW,
1688 	    &rack_ignore_data_after_close, 1,
1689 	    "Do we hold off sending a RST until all pending data is ack'd");
1690 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1691 	    SYSCTL_CHILDREN(rack_misc),
1692 	    OID_AUTO, "no_sack_needed", CTLFLAG_RW,
1693 	    &rack_sack_not_required, 1,
1694 	    "Do we allow rack to run on connections not supporting SACK");
1695 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1696 	    SYSCTL_CHILDREN(rack_misc),
1697 	    OID_AUTO, "prr_sendalot", CTLFLAG_RW,
1698 	    &rack_send_a_lot_in_prr, 1,
1699 	    "Send a lot in prr");
1700 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1701 	    SYSCTL_CHILDREN(rack_misc),
1702 	    OID_AUTO, "autoscale", CTLFLAG_RW,
1703 	    &rack_autosndbuf_inc, 20,
1704 	    "What percentage should rack scale up its snd buffer by?");
1705 
1706 
1707 	/* Sack Attacker detection stuff */
1708 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1709 	    SYSCTL_CHILDREN(rack_attack),
1710 	    OID_AUTO, "merge_out", CTLFLAG_RW,
1711 	    &rack_merge_out_sacks_on_attack, 0,
1712 	    "Do we merge the sendmap when we decide we are being attacked?");
1713 
1714 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1715 	    SYSCTL_CHILDREN(rack_attack),
1716 	    OID_AUTO, "detect_highsackratio", CTLFLAG_RW,
1717 	    &rack_highest_sack_thresh_seen, 0,
1718 	    "Highest sack to ack ratio seen");
1719 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1720 	    SYSCTL_CHILDREN(rack_attack),
1721 	    OID_AUTO, "detect_highmoveratio", CTLFLAG_RW,
1722 	    &rack_highest_move_thresh_seen, 0,
1723 	    "Highest move to non-move ratio seen");
1724 	rack_ack_total = counter_u64_alloc(M_WAITOK);
1725 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1726 	    SYSCTL_CHILDREN(rack_attack),
1727 	    OID_AUTO, "acktotal", CTLFLAG_RD,
1728 	    &rack_ack_total,
1729 	    "Total number of Ack's");
1730 	rack_express_sack = counter_u64_alloc(M_WAITOK);
1731 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1732 	    SYSCTL_CHILDREN(rack_attack),
1733 	    OID_AUTO, "exp_sacktotal", CTLFLAG_RD,
1734 	    &rack_express_sack,
1735 	    "Total expresss number of Sack's");
1736 	rack_sack_total = counter_u64_alloc(M_WAITOK);
1737 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1738 	    SYSCTL_CHILDREN(rack_attack),
1739 	    OID_AUTO, "sacktotal", CTLFLAG_RD,
1740 	    &rack_sack_total,
1741 	    "Total number of SACKs");
1742 	rack_move_none = counter_u64_alloc(M_WAITOK);
1743 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1744 	    SYSCTL_CHILDREN(rack_attack),
1745 	    OID_AUTO, "move_none", CTLFLAG_RD,
1746 	    &rack_move_none,
1747 	    "Total number of SACK index reuse of positions under threshold");
1748 	rack_move_some = counter_u64_alloc(M_WAITOK);
1749 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1750 	    SYSCTL_CHILDREN(rack_attack),
1751 	    OID_AUTO, "move_some", CTLFLAG_RD,
1752 	    &rack_move_some,
1753 	    "Total number of SACK index reuse of positions over threshold");
1754 	rack_sack_attacks_detected = counter_u64_alloc(M_WAITOK);
1755 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1756 	    SYSCTL_CHILDREN(rack_attack),
1757 	    OID_AUTO, "attacks", CTLFLAG_RD,
1758 	    &rack_sack_attacks_detected,
1759 	    "Total number of SACK attackers that had sack disabled");
1760 	rack_sack_attacks_reversed = counter_u64_alloc(M_WAITOK);
1761 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1762 	    SYSCTL_CHILDREN(rack_attack),
1763 	    OID_AUTO, "reversed", CTLFLAG_RD,
1764 	    &rack_sack_attacks_reversed,
1765 	    "Total number of SACK attackers that were later determined false positive");
1766 	rack_sack_attacks_suspect = counter_u64_alloc(M_WAITOK);
1767 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1768 	    SYSCTL_CHILDREN(rack_attack),
1769 	    OID_AUTO, "suspect", CTLFLAG_RD,
1770 	    &rack_sack_attacks_suspect,
1771 	    "Total number of SACKs that triggered early detection");
1772 
1773 	rack_sack_used_next_merge = counter_u64_alloc(M_WAITOK);
1774 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1775 	    SYSCTL_CHILDREN(rack_attack),
1776 	    OID_AUTO, "nextmerge", CTLFLAG_RD,
1777 	    &rack_sack_used_next_merge,
1778 	    "Total number of times we used the next merge");
1779 	rack_sack_used_prev_merge = counter_u64_alloc(M_WAITOK);
1780 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1781 	    SYSCTL_CHILDREN(rack_attack),
1782 	    OID_AUTO, "prevmerge", CTLFLAG_RD,
1783 	    &rack_sack_used_prev_merge,
1784 	    "Total number of times we used the prev merge");
1785 	/* Counters */
1786 	rack_total_bytes = counter_u64_alloc(M_WAITOK);
1787 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1788 	    SYSCTL_CHILDREN(rack_counters),
1789 	    OID_AUTO, "totalbytes", CTLFLAG_RD,
1790 	    &rack_total_bytes,
1791 	    "Total number of bytes sent");
1792 	rack_fto_send = counter_u64_alloc(M_WAITOK);
1793 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1794 	    SYSCTL_CHILDREN(rack_counters),
1795 	    OID_AUTO, "fto_send", CTLFLAG_RD,
1796 	    &rack_fto_send, "Total number of rack_fast_output sends");
1797 	rack_fto_rsm_send = counter_u64_alloc(M_WAITOK);
1798 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1799 	    SYSCTL_CHILDREN(rack_counters),
1800 	    OID_AUTO, "fto_rsm_send", CTLFLAG_RD,
1801 	    &rack_fto_rsm_send, "Total number of rack_fast_rsm_output sends");
1802 	rack_nfto_resend = counter_u64_alloc(M_WAITOK);
1803 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1804 	    SYSCTL_CHILDREN(rack_counters),
1805 	    OID_AUTO, "nfto_resend", CTLFLAG_RD,
1806 	    &rack_nfto_resend, "Total number of rack_output retransmissions");
1807 	rack_non_fto_send = counter_u64_alloc(M_WAITOK);
1808 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1809 	    SYSCTL_CHILDREN(rack_counters),
1810 	    OID_AUTO, "nfto_send", CTLFLAG_RD,
1811 	    &rack_non_fto_send, "Total number of rack_output first sends");
1812 	rack_extended_rfo = counter_u64_alloc(M_WAITOK);
1813 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1814 	    SYSCTL_CHILDREN(rack_counters),
1815 	    OID_AUTO, "rfo_extended", CTLFLAG_RD,
1816 	    &rack_extended_rfo, "Total number of times we extended rfo");
1817 
1818 	rack_hw_pace_init_fail = counter_u64_alloc(M_WAITOK);
1819 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1820 	    SYSCTL_CHILDREN(rack_counters),
1821 	    OID_AUTO, "hwpace_init_fail", CTLFLAG_RD,
1822 	    &rack_hw_pace_init_fail, "Total number of times we failed to initialize hw pacing");
1823 	rack_hw_pace_lost = counter_u64_alloc(M_WAITOK);
1824 
1825 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1826 	    SYSCTL_CHILDREN(rack_counters),
1827 	    OID_AUTO, "hwpace_lost", CTLFLAG_RD,
1828 	    &rack_hw_pace_lost, "Total number of times we failed to initialize hw pacing");
1829 	rack_tlp_tot = counter_u64_alloc(M_WAITOK);
1830 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1831 	    SYSCTL_CHILDREN(rack_counters),
1832 	    OID_AUTO, "tlp_to_total", CTLFLAG_RD,
1833 	    &rack_tlp_tot,
1834 	    "Total number of tail loss probe expirations");
1835 	rack_tlp_newdata = counter_u64_alloc(M_WAITOK);
1836 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1837 	    SYSCTL_CHILDREN(rack_counters),
1838 	    OID_AUTO, "tlp_new", CTLFLAG_RD,
1839 	    &rack_tlp_newdata,
1840 	    "Total number of tail loss probe sending new data");
1841 	rack_tlp_retran = counter_u64_alloc(M_WAITOK);
1842 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1843 	    SYSCTL_CHILDREN(rack_counters),
1844 	    OID_AUTO, "tlp_retran", CTLFLAG_RD,
1845 	    &rack_tlp_retran,
1846 	    "Total number of tail loss probe sending retransmitted data");
1847 	rack_tlp_retran_bytes = counter_u64_alloc(M_WAITOK);
1848 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1849 	    SYSCTL_CHILDREN(rack_counters),
1850 	    OID_AUTO, "tlp_retran_bytes", CTLFLAG_RD,
1851 	    &rack_tlp_retran_bytes,
1852 	    "Total bytes of tail loss probe sending retransmitted data");
1853 	rack_to_tot = counter_u64_alloc(M_WAITOK);
1854 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1855 	    SYSCTL_CHILDREN(rack_counters),
1856 	    OID_AUTO, "rack_to_tot", CTLFLAG_RD,
1857 	    &rack_to_tot,
1858 	    "Total number of times the rack to expired");
1859 	rack_saw_enobuf = counter_u64_alloc(M_WAITOK);
1860 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1861 	    SYSCTL_CHILDREN(rack_counters),
1862 	    OID_AUTO, "saw_enobufs", CTLFLAG_RD,
1863 	    &rack_saw_enobuf,
1864 	    "Total number of times a sends returned enobuf for non-hdwr paced connections");
1865 	rack_saw_enobuf_hw = counter_u64_alloc(M_WAITOK);
1866 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1867 	    SYSCTL_CHILDREN(rack_counters),
1868 	    OID_AUTO, "saw_enobufs_hw", CTLFLAG_RD,
1869 	    &rack_saw_enobuf_hw,
1870 	    "Total number of times a send returned enobuf for hdwr paced connections");
1871 	rack_saw_enetunreach = counter_u64_alloc(M_WAITOK);
1872 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1873 	    SYSCTL_CHILDREN(rack_counters),
1874 	    OID_AUTO, "saw_enetunreach", CTLFLAG_RD,
1875 	    &rack_saw_enetunreach,
1876 	    "Total number of times a send received a enetunreachable");
1877 	rack_hot_alloc = counter_u64_alloc(M_WAITOK);
1878 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1879 	    SYSCTL_CHILDREN(rack_counters),
1880 	    OID_AUTO, "alloc_hot", CTLFLAG_RD,
1881 	    &rack_hot_alloc,
1882 	    "Total allocations from the top of our list");
1883 	tcp_policer_detected = counter_u64_alloc(M_WAITOK);
1884 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1885 	    SYSCTL_CHILDREN(rack_counters),
1886 	    OID_AUTO, "policer_detected", CTLFLAG_RD,
1887 	    &tcp_policer_detected,
1888 	    "Total policer_detections");
1889 
1890 	rack_to_alloc = counter_u64_alloc(M_WAITOK);
1891 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1892 	    SYSCTL_CHILDREN(rack_counters),
1893 	    OID_AUTO, "allocs", CTLFLAG_RD,
1894 	    &rack_to_alloc,
1895 	    "Total allocations of tracking structures");
1896 	rack_to_alloc_hard = counter_u64_alloc(M_WAITOK);
1897 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1898 	    SYSCTL_CHILDREN(rack_counters),
1899 	    OID_AUTO, "allochard", CTLFLAG_RD,
1900 	    &rack_to_alloc_hard,
1901 	    "Total allocations done with sleeping the hard way");
1902 	rack_to_alloc_emerg = counter_u64_alloc(M_WAITOK);
1903 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1904 	    SYSCTL_CHILDREN(rack_counters),
1905 	    OID_AUTO, "allocemerg", CTLFLAG_RD,
1906 	    &rack_to_alloc_emerg,
1907 	    "Total allocations done from emergency cache");
1908 	rack_to_alloc_limited = counter_u64_alloc(M_WAITOK);
1909 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1910 	    SYSCTL_CHILDREN(rack_counters),
1911 	    OID_AUTO, "alloc_limited", CTLFLAG_RD,
1912 	    &rack_to_alloc_limited,
1913 	    "Total allocations dropped due to limit");
1914 	rack_alloc_limited_conns = counter_u64_alloc(M_WAITOK);
1915 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1916 	    SYSCTL_CHILDREN(rack_counters),
1917 	    OID_AUTO, "alloc_limited_conns", CTLFLAG_RD,
1918 	    &rack_alloc_limited_conns,
1919 	    "Connections with allocations dropped due to limit");
1920 	rack_split_limited = counter_u64_alloc(M_WAITOK);
1921 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1922 	    SYSCTL_CHILDREN(rack_counters),
1923 	    OID_AUTO, "split_limited", CTLFLAG_RD,
1924 	    &rack_split_limited,
1925 	    "Split allocations dropped due to limit");
1926 	rack_rxt_clamps_cwnd = counter_u64_alloc(M_WAITOK);
1927 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1928 	    SYSCTL_CHILDREN(rack_counters),
1929 	    OID_AUTO, "rxt_clamps_cwnd", CTLFLAG_RD,
1930 	    &rack_rxt_clamps_cwnd,
1931 	    "Number of times that excessive rxt clamped the cwnd down");
1932 	rack_rxt_clamps_cwnd_uniq = counter_u64_alloc(M_WAITOK);
1933 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1934 	    SYSCTL_CHILDREN(rack_counters),
1935 	    OID_AUTO, "rxt_clamps_cwnd_uniq", CTLFLAG_RD,
1936 	    &rack_rxt_clamps_cwnd_uniq,
1937 	    "Number of connections that have had excessive rxt clamped the cwnd down");
1938 	rack_persists_sends = counter_u64_alloc(M_WAITOK);
1939 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1940 	    SYSCTL_CHILDREN(rack_counters),
1941 	    OID_AUTO, "persist_sends", CTLFLAG_RD,
1942 	    &rack_persists_sends,
1943 	    "Number of times we sent a persist probe");
1944 	rack_persists_acks = counter_u64_alloc(M_WAITOK);
1945 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1946 	    SYSCTL_CHILDREN(rack_counters),
1947 	    OID_AUTO, "persist_acks", CTLFLAG_RD,
1948 	    &rack_persists_acks,
1949 	    "Number of times a persist probe was acked");
1950 	rack_persists_loss = counter_u64_alloc(M_WAITOK);
1951 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1952 	    SYSCTL_CHILDREN(rack_counters),
1953 	    OID_AUTO, "persist_loss", CTLFLAG_RD,
1954 	    &rack_persists_loss,
1955 	    "Number of times we detected a lost persist probe (no ack)");
1956 	rack_persists_lost_ends = counter_u64_alloc(M_WAITOK);
1957 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1958 	    SYSCTL_CHILDREN(rack_counters),
1959 	    OID_AUTO, "persist_loss_ends", CTLFLAG_RD,
1960 	    &rack_persists_lost_ends,
1961 	    "Number of lost persist probe (no ack) that the run ended with a PERSIST abort");
1962 #ifdef INVARIANTS
1963 	rack_adjust_map_bw = counter_u64_alloc(M_WAITOK);
1964 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1965 	    SYSCTL_CHILDREN(rack_counters),
1966 	    OID_AUTO, "map_adjust_req", CTLFLAG_RD,
1967 	    &rack_adjust_map_bw,
1968 	    "Number of times we hit the case where the sb went up and down on a sendmap entry");
1969 #endif
1970 	rack_multi_single_eq = counter_u64_alloc(M_WAITOK);
1971 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1972 	    SYSCTL_CHILDREN(rack_counters),
1973 	    OID_AUTO, "cmp_ack_equiv", CTLFLAG_RD,
1974 	    &rack_multi_single_eq,
1975 	    "Number of compressed acks total represented");
1976 	rack_proc_non_comp_ack = counter_u64_alloc(M_WAITOK);
1977 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1978 	    SYSCTL_CHILDREN(rack_counters),
1979 	    OID_AUTO, "cmp_ack_not", CTLFLAG_RD,
1980 	    &rack_proc_non_comp_ack,
1981 	    "Number of non compresseds acks that we processed");
1982 
1983 
1984 	rack_sack_proc_all = counter_u64_alloc(M_WAITOK);
1985 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1986 	    SYSCTL_CHILDREN(rack_counters),
1987 	    OID_AUTO, "sack_long", CTLFLAG_RD,
1988 	    &rack_sack_proc_all,
1989 	    "Total times we had to walk whole list for sack processing");
1990 	rack_sack_proc_restart = counter_u64_alloc(M_WAITOK);
1991 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1992 	    SYSCTL_CHILDREN(rack_counters),
1993 	    OID_AUTO, "sack_restart", CTLFLAG_RD,
1994 	    &rack_sack_proc_restart,
1995 	    "Total times we had to walk whole list due to a restart");
1996 	rack_sack_proc_short = counter_u64_alloc(M_WAITOK);
1997 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1998 	    SYSCTL_CHILDREN(rack_counters),
1999 	    OID_AUTO, "sack_short", CTLFLAG_RD,
2000 	    &rack_sack_proc_short,
2001 	    "Total times we took shortcut for sack processing");
2002 	rack_sack_skipped_acked = counter_u64_alloc(M_WAITOK);
2003 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
2004 	    SYSCTL_CHILDREN(rack_attack),
2005 	    OID_AUTO, "skipacked", CTLFLAG_RD,
2006 	    &rack_sack_skipped_acked,
2007 	    "Total number of times we skipped previously sacked");
2008 	rack_sack_splits = counter_u64_alloc(M_WAITOK);
2009 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
2010 	    SYSCTL_CHILDREN(rack_attack),
2011 	    OID_AUTO, "ofsplit", CTLFLAG_RD,
2012 	    &rack_sack_splits,
2013 	    "Total number of times we did the old fashion tree split");
2014 	rack_input_idle_reduces = counter_u64_alloc(M_WAITOK);
2015 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
2016 	    SYSCTL_CHILDREN(rack_counters),
2017 	    OID_AUTO, "idle_reduce_oninput", CTLFLAG_RD,
2018 	    &rack_input_idle_reduces,
2019 	    "Total number of idle reductions on input");
2020 	rack_collapsed_win_seen = counter_u64_alloc(M_WAITOK);
2021 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
2022 	    SYSCTL_CHILDREN(rack_counters),
2023 	    OID_AUTO, "collapsed_win_seen", CTLFLAG_RD,
2024 	    &rack_collapsed_win_seen,
2025 	    "Total number of collapsed window events seen (where our window shrinks)");
2026 
2027 	rack_collapsed_win = counter_u64_alloc(M_WAITOK);
2028 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
2029 	    SYSCTL_CHILDREN(rack_counters),
2030 	    OID_AUTO, "collapsed_win", CTLFLAG_RD,
2031 	    &rack_collapsed_win,
2032 	    "Total number of collapsed window events where we mark packets");
2033 	rack_collapsed_win_rxt = counter_u64_alloc(M_WAITOK);
2034 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
2035 	    SYSCTL_CHILDREN(rack_counters),
2036 	    OID_AUTO, "collapsed_win_rxt", CTLFLAG_RD,
2037 	    &rack_collapsed_win_rxt,
2038 	    "Total number of packets that were retransmitted");
2039 	rack_collapsed_win_rxt_bytes = counter_u64_alloc(M_WAITOK);
2040 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
2041 	    SYSCTL_CHILDREN(rack_counters),
2042 	    OID_AUTO, "collapsed_win_bytes", CTLFLAG_RD,
2043 	    &rack_collapsed_win_rxt_bytes,
2044 	    "Total number of bytes that were retransmitted");
2045 	rack_try_scwnd = counter_u64_alloc(M_WAITOK);
2046 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
2047 	    SYSCTL_CHILDREN(rack_counters),
2048 	    OID_AUTO, "tried_scwnd", CTLFLAG_RD,
2049 	    &rack_try_scwnd,
2050 	    "Total number of scwnd attempts");
2051 	COUNTER_ARRAY_ALLOC(rack_out_size, TCP_MSS_ACCT_SIZE, M_WAITOK);
2052 	SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
2053 	    OID_AUTO, "outsize", CTLFLAG_RD,
2054 	    rack_out_size, TCP_MSS_ACCT_SIZE, "MSS send sizes");
2055 	COUNTER_ARRAY_ALLOC(rack_opts_arry, RACK_OPTS_SIZE, M_WAITOK);
2056 	SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
2057 	    OID_AUTO, "opts", CTLFLAG_RD,
2058 	    rack_opts_arry, RACK_OPTS_SIZE, "RACK Option Stats");
2059 	SYSCTL_ADD_PROC(&rack_sysctl_ctx,
2060 	    SYSCTL_CHILDREN(rack_sysctl_root),
2061 	    OID_AUTO, "clear", CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE,
2062 	    &rack_clear_counter, 0, sysctl_rack_clear, "IU", "Clear counters");
2063 }
2064 
2065 static uint32_t
rc_init_window(struct tcp_rack * rack)2066 rc_init_window(struct tcp_rack *rack)
2067 {
2068 	return (tcp_compute_initwnd(tcp_maxseg(rack->rc_tp)));
2069 
2070 }
2071 
2072 static uint64_t
rack_get_fixed_pacing_bw(struct tcp_rack * rack)2073 rack_get_fixed_pacing_bw(struct tcp_rack *rack)
2074 {
2075 	if (IN_FASTRECOVERY(rack->rc_tp->t_flags))
2076 		return (rack->r_ctl.rc_fixed_pacing_rate_rec);
2077 	else if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
2078 		return (rack->r_ctl.rc_fixed_pacing_rate_ss);
2079 	else
2080 		return (rack->r_ctl.rc_fixed_pacing_rate_ca);
2081 }
2082 
2083 static void
rack_log_hybrid_bw(struct tcp_rack * rack,uint32_t seq,uint64_t cbw,uint64_t tim,uint64_t data,uint8_t mod,uint16_t aux,struct tcp_sendfile_track * cur,int line)2084 rack_log_hybrid_bw(struct tcp_rack *rack, uint32_t seq, uint64_t cbw, uint64_t tim,
2085 	uint64_t data, uint8_t mod, uint16_t aux,
2086 	struct tcp_sendfile_track *cur, int line)
2087 {
2088 #ifdef TCP_REQUEST_TRK
2089 	int do_log = 0;
2090 
2091 	/*
2092 	 * The rate cap one is noisy and only should come out when normal BB logging
2093 	 * is enabled, the other logs (not RATE_CAP and NOT CAP_CALC) only come out
2094 	 * once per chunk and make up the BBpoint that can be turned on by the client.
2095 	 */
2096 	if ((mod == HYBRID_LOG_RATE_CAP) || (mod == HYBRID_LOG_CAP_CALC)) {
2097 		/*
2098 		 * The very noisy two need to only come out when
2099 		 * we have verbose logging on.
2100 		 */
2101 		if (rack_verbose_logging != 0)
2102 			do_log = tcp_bblogging_on(rack->rc_tp);
2103 		else
2104 			do_log = 0;
2105 	} else if (mod != HYBRID_LOG_BW_MEASURE) {
2106 		/*
2107 		 * All other less noisy logs here except the measure which
2108 		 * also needs to come out on the point and the log.
2109 		 */
2110 		do_log = tcp_bblogging_on(rack->rc_tp);
2111 	} else {
2112 		do_log = tcp_bblogging_point_on(rack->rc_tp, TCP_BBPOINT_REQ_LEVEL_LOGGING);
2113 	}
2114 
2115 	if (do_log) {
2116 		union tcp_log_stackspecific log;
2117 		struct timeval tv;
2118 		uint64_t lt_bw;
2119 
2120 		/* Convert our ms to a microsecond */
2121 		memset(&log, 0, sizeof(log));
2122 
2123 		log.u_bbr.cwnd_gain = line;
2124 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2125 		log.u_bbr.rttProp = tim;
2126 		log.u_bbr.bw_inuse = cbw;
2127 		log.u_bbr.delRate = rack_get_gp_est(rack);
2128 		lt_bw = rack_get_lt_bw(rack);
2129 		log.u_bbr.flex1 = seq;
2130 		log.u_bbr.pacing_gain = aux;
2131 		/* lt_bw = < flex3 | flex2 > */
2132 		log.u_bbr.flex2 = (uint32_t)(lt_bw & 0x00000000ffffffff);
2133 		log.u_bbr.flex3 = (uint32_t)((lt_bw >> 32) & 0x00000000ffffffff);
2134 		/* Record the last obtained us rtt in inflight */
2135 		if (cur == NULL) {
2136 			/* Make sure we are looking at the right log if an overide comes in */
2137 			cur = rack->r_ctl.rc_last_sft;
2138 		}
2139 		if (rack->r_ctl.rack_rs.rs_flags != RACK_RTT_EMPTY)
2140 			log.u_bbr.inflight = rack->r_ctl.rack_rs.rs_us_rtt;
2141 		else {
2142 			/* Use the last known rtt i.e. the rack-rtt */
2143 			log.u_bbr.inflight = rack->rc_rack_rtt;
2144 		}
2145 		if (cur != NULL) {
2146 			uint64_t off;
2147 
2148 			log.u_bbr.cur_del_rate = cur->deadline;
2149 			if ((mod == HYBRID_LOG_RATE_CAP) || (mod == HYBRID_LOG_CAP_CALC)) {
2150 				/* start = < lost | pkt_epoch > */
2151 				log.u_bbr.pkt_epoch = (uint32_t)(cur->start & 0x00000000ffffffff);
2152 				log.u_bbr.lost = (uint32_t)((cur->start >> 32) & 0x00000000ffffffff);
2153 				log.u_bbr.flex6 = cur->start_seq;
2154 				log.u_bbr.pkts_out = cur->end_seq;
2155 			} else {
2156 				/* start = < lost | pkt_epoch > */
2157 				log.u_bbr.pkt_epoch = (uint32_t)(cur->start & 0x00000000ffffffff);
2158 				log.u_bbr.lost = (uint32_t)((cur->start >> 32) & 0x00000000ffffffff);
2159 				/* end = < pkts_out | flex6 > */
2160 				log.u_bbr.flex6 = (uint32_t)(cur->end & 0x00000000ffffffff);
2161 				log.u_bbr.pkts_out = (uint32_t)((cur->end >> 32) & 0x00000000ffffffff);
2162 			}
2163 			/* first_send = <lt_epoch | epoch> */
2164 			log.u_bbr.epoch = (uint32_t)(cur->first_send & 0x00000000ffffffff);
2165 			log.u_bbr.lt_epoch = (uint32_t)((cur->first_send >> 32) & 0x00000000ffffffff);
2166 			/* localtime = <delivered | applimited>*/
2167 			log.u_bbr.applimited = (uint32_t)(cur->localtime & 0x00000000ffffffff);
2168 			log.u_bbr.delivered = (uint32_t)((cur->localtime >> 32) & 0x00000000ffffffff);
2169 #ifdef TCP_REQUEST_TRK
2170 			off = (uint64_t)(cur) - (uint64_t)(&rack->rc_tp->t_tcpreq_info[0]);
2171 			log.u_bbr.bbr_substate = (uint8_t)(off / sizeof(struct tcp_sendfile_track));
2172 #endif
2173 			log.u_bbr.inhpts = 1;
2174 			log.u_bbr.flex4 = (uint32_t)(rack->rc_tp->t_sndbytes - cur->sent_at_fs);
2175 			log.u_bbr.flex5 = (uint32_t)(rack->rc_tp->t_snd_rxt_bytes - cur->rxt_at_fs);
2176 			log.u_bbr.flex7 = (uint16_t)cur->hybrid_flags;
2177 		} else {
2178 			log.u_bbr.flex7 = 0xffff;
2179 			log.u_bbr.cur_del_rate = 0xffffffffffffffff;
2180 		}
2181 		/*
2182 		 * Compose bbr_state to be a bit wise 0000ADHF
2183 		 * where A is the always_pace flag
2184 		 * where D is the dgp_on flag
2185 		 * where H is the hybrid_mode on flag
2186 		 * where F is the use_fixed_rate flag.
2187 		 */
2188 		log.u_bbr.bbr_state = rack->rc_always_pace;
2189 		log.u_bbr.bbr_state <<= 1;
2190 		log.u_bbr.bbr_state |= rack->dgp_on;
2191 		log.u_bbr.bbr_state <<= 1;
2192 		log.u_bbr.bbr_state |= rack->rc_hybrid_mode;
2193 		log.u_bbr.bbr_state <<= 1;
2194 		log.u_bbr.bbr_state |= rack->use_fixed_rate;
2195 		log.u_bbr.flex8 = mod;
2196 		tcp_log_event(rack->rc_tp, NULL,
2197 		    &rack->rc_inp->inp_socket->so_rcv,
2198 		    &rack->rc_inp->inp_socket->so_snd,
2199 		    TCP_HYBRID_PACING_LOG, 0,
2200 		    0, &log, false, NULL, __func__, __LINE__, &tv);
2201 
2202 	}
2203 #endif
2204 }
2205 
2206 #ifdef TCP_REQUEST_TRK
2207 static void
rack_log_hybrid_sends(struct tcp_rack * rack,struct tcp_sendfile_track * cur,int line)2208 rack_log_hybrid_sends(struct tcp_rack *rack, struct tcp_sendfile_track *cur, int line)
2209 {
2210 	if (tcp_bblogging_point_on(rack->rc_tp, TCP_BBPOINT_REQ_LEVEL_LOGGING)) {
2211 		union tcp_log_stackspecific log;
2212 		struct timeval tv;
2213 		uint64_t off;
2214 
2215 		/* Convert our ms to a microsecond */
2216 		memset(&log, 0, sizeof(log));
2217 
2218 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2219 		log.u_bbr.delRate = cur->sent_at_fs;
2220 
2221 		if ((cur->flags & TCP_TRK_TRACK_FLG_LSND) == 0) {
2222 			/*
2223 			 * We did not get a new Rules Applied to set so
2224 			 * no overlapping send occured, this means the
2225 			 * current byte counts are correct.
2226 			 */
2227 			log.u_bbr.cur_del_rate = rack->rc_tp->t_sndbytes;
2228 			log.u_bbr.rttProp = rack->rc_tp->t_snd_rxt_bytes;
2229 		} else {
2230 			/*
2231 			 * Overlapping send case, we switched to a new
2232 			 * send and did a rules applied.
2233 			 */
2234 			log.u_bbr.cur_del_rate = cur->sent_at_ls;
2235 			log.u_bbr.rttProp = cur->rxt_at_ls;
2236 		}
2237 		log.u_bbr.bw_inuse = cur->rxt_at_fs;
2238 		log.u_bbr.cwnd_gain = line;
2239 		off = (uint64_t)(cur) - (uint64_t)(&rack->rc_tp->t_tcpreq_info[0]);
2240 		log.u_bbr.bbr_substate = (uint8_t)(off / sizeof(struct tcp_sendfile_track));
2241 		/* start = < flex1 | flex2 > */
2242 		log.u_bbr.flex2 = (uint32_t)(cur->start & 0x00000000ffffffff);
2243 		log.u_bbr.flex1 = (uint32_t)((cur->start >> 32) & 0x00000000ffffffff);
2244 		/* end = < flex3 | flex4 > */
2245 		log.u_bbr.flex4 = (uint32_t)(cur->end & 0x00000000ffffffff);
2246 		log.u_bbr.flex3 = (uint32_t)((cur->end >> 32) & 0x00000000ffffffff);
2247 
2248 		/* localtime = <delivered | applimited>*/
2249 		log.u_bbr.applimited = (uint32_t)(cur->localtime & 0x00000000ffffffff);
2250 		log.u_bbr.delivered = (uint32_t)((cur->localtime >> 32) & 0x00000000ffffffff);
2251 		/* client timestamp = <lt_epoch | epoch>*/
2252 		log.u_bbr.epoch = (uint32_t)(cur->timestamp & 0x00000000ffffffff);
2253 		log.u_bbr.lt_epoch = (uint32_t)((cur->timestamp >> 32) & 0x00000000ffffffff);
2254 		/* now set all the flags in */
2255 		log.u_bbr.pkts_out = cur->hybrid_flags;
2256 		log.u_bbr.lost = cur->playout_ms;
2257 		log.u_bbr.flex6 = cur->flags;
2258 		/*
2259 		 * Last send time  = <flex5 | pkt_epoch>  note we do not distinguish cases
2260 		 * where a false retransmit occurred so first_send  <-> lastsend may
2261 		 * include longer time then it actually took if we have a false rxt.
2262 		 */
2263 		log.u_bbr.pkt_epoch = (uint32_t)(rack->r_ctl.last_tmit_time_acked & 0x00000000ffffffff);
2264 		log.u_bbr.flex5 = (uint32_t)((rack->r_ctl.last_tmit_time_acked >> 32) & 0x00000000ffffffff);
2265 		/*
2266 		 * Compose bbr_state to be a bit wise 0000ADHF
2267 		 * where A is the always_pace flag
2268 		 * where D is the dgp_on flag
2269 		 * where H is the hybrid_mode on flag
2270 		 * where F is the use_fixed_rate flag.
2271 		 */
2272 		log.u_bbr.bbr_state = rack->rc_always_pace;
2273 		log.u_bbr.bbr_state <<= 1;
2274 		log.u_bbr.bbr_state |= rack->dgp_on;
2275 		log.u_bbr.bbr_state <<= 1;
2276 		log.u_bbr.bbr_state |= rack->rc_hybrid_mode;
2277 		log.u_bbr.bbr_state <<= 1;
2278 		log.u_bbr.bbr_state |= rack->use_fixed_rate;
2279 
2280 		log.u_bbr.flex8 = HYBRID_LOG_SENT_LOST;
2281 		tcp_log_event(rack->rc_tp, NULL,
2282 		    &rack->rc_inp->inp_socket->so_rcv,
2283 		    &rack->rc_inp->inp_socket->so_snd,
2284 		    TCP_HYBRID_PACING_LOG, 0,
2285 		    0, &log, false, NULL, __func__, __LINE__, &tv);
2286 	}
2287 }
2288 #endif
2289 
2290 static inline uint64_t
rack_compensate_for_linerate(struct tcp_rack * rack,uint64_t bw)2291 rack_compensate_for_linerate(struct tcp_rack *rack, uint64_t bw)
2292 {
2293 	uint64_t ret_bw, ether;
2294 	uint64_t u_segsiz;
2295 
2296 	ether = rack->rc_tp->t_maxseg + sizeof(struct tcphdr);
2297 	if (rack->r_is_v6){
2298 #ifdef INET6
2299 		ether += sizeof(struct ip6_hdr);
2300 #endif
2301 		ether += 14;	/* eheader size 6+6+2 */
2302 	} else {
2303 #ifdef INET
2304 		ether += sizeof(struct ip);
2305 #endif
2306 		ether += 14;	/* eheader size 6+6+2 */
2307 	}
2308 	u_segsiz = (uint64_t)min(ctf_fixed_maxseg(rack->rc_tp), rack->r_ctl.rc_pace_min_segs);
2309 	ret_bw = bw;
2310 	ret_bw *= ether;
2311 	ret_bw /= u_segsiz;
2312 	return (ret_bw);
2313 }
2314 
2315 static void
rack_rate_cap_bw(struct tcp_rack * rack,uint64_t * bw,int * capped)2316 rack_rate_cap_bw(struct tcp_rack *rack, uint64_t *bw, int *capped)
2317 {
2318 #ifdef TCP_REQUEST_TRK
2319 	struct timeval tv;
2320 	uint64_t timenow, timeleft, lenleft, lengone, calcbw;
2321 #endif
2322 
2323 	if (rack->r_ctl.bw_rate_cap == 0)
2324 		return;
2325 #ifdef TCP_REQUEST_TRK
2326 	if (rack->rc_catch_up && rack->rc_hybrid_mode &&
2327 	    (rack->r_ctl.rc_last_sft != NULL)) {
2328 		/*
2329 		 * We have a dynamic cap. The original target
2330 		 * is in bw_rate_cap, but we need to look at
2331 		 * how long it is until we hit the deadline.
2332 		 */
2333 		struct tcp_sendfile_track *ent;
2334 
2335       		ent = rack->r_ctl.rc_last_sft;
2336 		microuptime(&tv);
2337 		timenow = tcp_tv_to_lusectick(&tv);
2338 		if (timenow >= ent->deadline) {
2339 			/* No time left we do DGP only */
2340 			rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2341 					   0, 0, 0, HYBRID_LOG_OUTOFTIME, 0, ent, __LINE__);
2342 			rack->r_ctl.bw_rate_cap = 0;
2343 			return;
2344 		}
2345 		/* We have the time */
2346 		timeleft = rack->r_ctl.rc_last_sft->deadline - timenow;
2347 		if (timeleft < HPTS_MSEC_IN_SEC) {
2348 			/* If there is less than a ms left just use DGPs rate */
2349 			rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2350 					   0, timeleft, 0, HYBRID_LOG_OUTOFTIME, 0, ent, __LINE__);
2351 			rack->r_ctl.bw_rate_cap = 0;
2352 			return;
2353 		}
2354 		/*
2355 		 * Now lets find the amount of data left to send.
2356 		 *
2357 		 * Now ideally we want to use the end_seq to figure out how much more
2358 		 * but it might not be possible (only if we have the TRACK_FG_COMP on the entry..
2359 		 */
2360 		if (ent->flags & TCP_TRK_TRACK_FLG_COMP) {
2361 			if (SEQ_GT(ent->end_seq, rack->rc_tp->snd_una))
2362 				lenleft = ent->end_seq - rack->rc_tp->snd_una;
2363 			else {
2364 				/* TSNH, we should catch it at the send */
2365 				rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2366 						   0, timeleft, 0, HYBRID_LOG_CAPERROR, 0, ent, __LINE__);
2367 				rack->r_ctl.bw_rate_cap = 0;
2368 				return;
2369 			}
2370 		} else {
2371 			/*
2372 			 * The hard way, figure out how much is gone and then
2373 			 * take that away from the total the client asked for
2374 			 * (thats off by tls overhead if this is tls).
2375 			 */
2376 			if (SEQ_GT(rack->rc_tp->snd_una, ent->start_seq))
2377 				lengone = rack->rc_tp->snd_una - ent->start_seq;
2378 			else
2379 				lengone = 0;
2380 			if (lengone < (ent->end - ent->start))
2381 				lenleft = (ent->end - ent->start) - lengone;
2382 			else {
2383 				/* TSNH, we should catch it at the send */
2384 				rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2385 						   0, timeleft, lengone, HYBRID_LOG_CAPERROR, 0, ent, __LINE__);
2386 				rack->r_ctl.bw_rate_cap = 0;
2387 				return;
2388 			}
2389 		}
2390 		if (lenleft == 0) {
2391 			/* We have it all sent */
2392 			rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2393 					   0, timeleft, lenleft, HYBRID_LOG_ALLSENT, 0, ent, __LINE__);
2394 			if (rack->r_ctl.bw_rate_cap)
2395 				goto normal_ratecap;
2396 			else
2397 				return;
2398 		}
2399 		calcbw = lenleft * HPTS_USEC_IN_SEC;
2400 		calcbw /= timeleft;
2401 		/* Now we must compensate for IP/TCP overhead */
2402 		calcbw = rack_compensate_for_linerate(rack, calcbw);
2403 		/* Update the bit rate cap */
2404 		rack->r_ctl.bw_rate_cap = calcbw;
2405 		if ((rack->r_ctl.rc_last_sft->hybrid_flags & TCP_HYBRID_PACING_S_MSS) &&
2406 		    (rack_hybrid_allow_set_maxseg == 1) &&
2407 		    ((rack->r_ctl.rc_last_sft->hybrid_flags & TCP_HYBRID_PACING_SETMSS) == 0)) {
2408 			/* Lets set in a smaller mss possibly here to match our rate-cap */
2409 			uint32_t orig_max;
2410 
2411 			orig_max = rack->r_ctl.rc_pace_max_segs;
2412 			rack->r_ctl.rc_last_sft->hybrid_flags |= TCP_HYBRID_PACING_SETMSS;
2413 			rack->r_ctl.rc_pace_max_segs = rack_get_pacing_len(rack, calcbw, ctf_fixed_maxseg(rack->rc_tp));
2414 			rack_log_type_pacing_sizes(rack->rc_tp, rack, rack->r_ctl.client_suggested_maxseg, orig_max, __LINE__, 5);
2415 		}
2416 		rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2417 				   calcbw, timeleft, lenleft, HYBRID_LOG_CAP_CALC, 0, ent, __LINE__);
2418 		if ((calcbw > 0) && (*bw > calcbw)) {
2419 			rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2420 					   *bw, ent->deadline, lenleft, HYBRID_LOG_RATE_CAP, 0, ent, __LINE__);
2421 			*capped = 1;
2422 			*bw = calcbw;
2423 		}
2424 		return;
2425 	}
2426 normal_ratecap:
2427 #endif
2428 	if ((rack->r_ctl.bw_rate_cap > 0) && (*bw > rack->r_ctl.bw_rate_cap)) {
2429 #ifdef TCP_REQUEST_TRK
2430 		if (rack->rc_hybrid_mode &&
2431 		    rack->rc_catch_up &&
2432 		    (rack->r_ctl.rc_last_sft != NULL) &&
2433 		    (rack->r_ctl.rc_last_sft->hybrid_flags & TCP_HYBRID_PACING_S_MSS) &&
2434 		    (rack_hybrid_allow_set_maxseg == 1) &&
2435 		    ((rack->r_ctl.rc_last_sft->hybrid_flags & TCP_HYBRID_PACING_SETMSS) == 0)) {
2436 			/* Lets set in a smaller mss possibly here to match our rate-cap */
2437 			uint32_t orig_max;
2438 
2439 			orig_max = rack->r_ctl.rc_pace_max_segs;
2440 			rack->r_ctl.rc_last_sft->hybrid_flags |= TCP_HYBRID_PACING_SETMSS;
2441 			rack->r_ctl.rc_pace_max_segs = rack_get_pacing_len(rack, rack->r_ctl.bw_rate_cap, ctf_fixed_maxseg(rack->rc_tp));
2442 			rack_log_type_pacing_sizes(rack->rc_tp, rack, rack->r_ctl.client_suggested_maxseg, orig_max, __LINE__, 5);
2443 		}
2444 #endif
2445 		*capped = 1;
2446 		*bw = rack->r_ctl.bw_rate_cap;
2447 		rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2448 				   *bw, 0, 0,
2449 				   HYBRID_LOG_RATE_CAP, 1, NULL, __LINE__);
2450 	}
2451 }
2452 
2453 static uint64_t
rack_get_gp_est(struct tcp_rack * rack)2454 rack_get_gp_est(struct tcp_rack *rack)
2455 {
2456 	uint64_t bw, lt_bw, ret_bw;
2457 
2458 	if (rack->rc_gp_filled == 0) {
2459 		/*
2460 		 * We have yet no b/w measurement,
2461 		 * if we have a user set initial bw
2462 		 * return it. If we don't have that and
2463 		 * we have an srtt, use the tcp IW (10) to
2464 		 * calculate a fictional b/w over the SRTT
2465 		 * which is more or less a guess. Note
2466 		 * we don't use our IW from rack on purpose
2467 		 * so if we have like IW=30, we are not
2468 		 * calculating a "huge" b/w.
2469 		 */
2470 		uint64_t srtt;
2471 
2472 		if (rack->dis_lt_bw == 1)
2473 			lt_bw = 0;
2474 		else
2475 			lt_bw = rack_get_lt_bw(rack);
2476 		if (lt_bw) {
2477 			/*
2478 			 * No goodput bw but a long-term b/w does exist
2479 			 * lets use that.
2480 			 */
2481 			ret_bw = lt_bw;
2482 			goto compensate;
2483 		}
2484 		if (rack->r_ctl.init_rate)
2485 			return (rack->r_ctl.init_rate);
2486 
2487 		/* Ok lets come up with the IW guess, if we have a srtt */
2488 		if (rack->rc_tp->t_srtt == 0) {
2489 			/*
2490 			 * Go with old pacing method
2491 			 * i.e. burst mitigation only.
2492 			 */
2493 			return (0);
2494 		}
2495 		/* Ok lets get the initial TCP win (not racks) */
2496 		bw = tcp_compute_initwnd(tcp_maxseg(rack->rc_tp));
2497 		srtt = (uint64_t)rack->rc_tp->t_srtt;
2498 		bw *= (uint64_t)USECS_IN_SECOND;
2499 		bw /= srtt;
2500 		ret_bw = bw;
2501 		goto compensate;
2502 
2503 	}
2504 	if (rack->r_ctl.num_measurements >= RACK_REQ_AVG) {
2505 		/* Averaging is done, we can return the value */
2506 		bw = rack->r_ctl.gp_bw;
2507 	} else {
2508 		/* Still doing initial average must calculate */
2509 		bw = rack->r_ctl.gp_bw / max(rack->r_ctl.num_measurements, 1);
2510 	}
2511 	if (rack->dis_lt_bw) {
2512 		/* We are not using lt-bw */
2513 		ret_bw = bw;
2514 		goto compensate;
2515 	}
2516 	lt_bw = rack_get_lt_bw(rack);
2517 	if (lt_bw == 0) {
2518 		/* If we don't have one then equate it to the gp_bw */
2519 		lt_bw = rack->r_ctl.gp_bw;
2520 	}
2521 	if (rack->use_lesser_lt_bw) {
2522 		if (lt_bw < bw)
2523 			ret_bw = lt_bw;
2524 		else
2525 			ret_bw = bw;
2526 	} else {
2527 		if (lt_bw > bw)
2528 			ret_bw = lt_bw;
2529 		else
2530 			ret_bw = bw;
2531 	}
2532 	/*
2533 	 * Now lets compensate based on the TCP/IP overhead. Our
2534 	 * Goodput estimate does not include this so we must pace out
2535 	 * a bit faster since our pacing calculations do. The pacing
2536 	 * calculations use the base ETHERNET_SEGMENT_SIZE and the segsiz
2537 	 * we are using to do this, so we do that here in the opposite
2538 	 * direction as well. This means that if we are tunneled and the
2539 	 * segsiz is say 1200 bytes we will get quite a boost, but its
2540 	 * compensated for in the pacing time the opposite way.
2541 	 */
2542 compensate:
2543 	ret_bw = rack_compensate_for_linerate(rack, ret_bw);
2544 	return(ret_bw);
2545 }
2546 
2547 
2548 static uint64_t
rack_get_bw(struct tcp_rack * rack)2549 rack_get_bw(struct tcp_rack *rack)
2550 {
2551 	uint64_t bw;
2552 
2553 	if (rack->use_fixed_rate) {
2554 		/* Return the fixed pacing rate */
2555 		return (rack_get_fixed_pacing_bw(rack));
2556 	}
2557 	bw = rack_get_gp_est(rack);
2558 	return (bw);
2559 }
2560 
2561 static uint16_t
rack_get_output_gain(struct tcp_rack * rack,struct rack_sendmap * rsm)2562 rack_get_output_gain(struct tcp_rack *rack, struct rack_sendmap *rsm)
2563 {
2564 	if (rack->use_fixed_rate) {
2565 		return (100);
2566 	} else if (rack->in_probe_rtt && (rsm == NULL))
2567 		return (rack->r_ctl.rack_per_of_gp_probertt);
2568 	else if ((IN_FASTRECOVERY(rack->rc_tp->t_flags) &&
2569 		  rack->r_ctl.rack_per_of_gp_rec)) {
2570 		if (rsm) {
2571 			/* a retransmission always use the recovery rate */
2572 			return (rack->r_ctl.rack_per_of_gp_rec);
2573 		} else if (rack->rack_rec_nonrxt_use_cr) {
2574 			/* Directed to use the configured rate */
2575 			goto configured_rate;
2576 		} else if (rack->rack_no_prr &&
2577 			   (rack->r_ctl.rack_per_of_gp_rec > 100)) {
2578 			/* No PRR, lets just use the b/w estimate only */
2579 			return (100);
2580 		} else {
2581 			/*
2582 			 * Here we may have a non-retransmit but we
2583 			 * have no overrides, so just use the recovery
2584 			 * rate (prr is in effect).
2585 			 */
2586 			return (rack->r_ctl.rack_per_of_gp_rec);
2587 		}
2588 	}
2589 configured_rate:
2590 	/* For the configured rate we look at our cwnd vs the ssthresh */
2591 	if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
2592 		return (rack->r_ctl.rack_per_of_gp_ss);
2593 	else
2594 		return (rack->r_ctl.rack_per_of_gp_ca);
2595 }
2596 
2597 static void
rack_log_dsack_event(struct tcp_rack * rack,uint8_t mod,uint32_t flex4,uint32_t flex5,uint32_t flex6)2598 rack_log_dsack_event(struct tcp_rack *rack, uint8_t mod, uint32_t flex4, uint32_t flex5, uint32_t flex6)
2599 {
2600 	/*
2601 	 * Types of logs (mod value)
2602 	 * 1 = dsack_persists reduced by 1 via T-O or fast recovery exit.
2603 	 * 2 = a dsack round begins, persist is reset to 16.
2604 	 * 3 = a dsack round ends
2605 	 * 4 = Dsack option increases rack rtt flex5 is the srtt input, flex6 is thresh
2606 	 * 5 = Socket option set changing the control flags rc_rack_tmr_std_based, rc_rack_use_dsack
2607 	 * 6 = Final rack rtt, flex4 is srtt and flex6 is final limited thresh.
2608 	 */
2609 	if (tcp_bblogging_on(rack->rc_tp)) {
2610 		union tcp_log_stackspecific log;
2611 		struct timeval tv;
2612 
2613 		memset(&log, 0, sizeof(log));
2614 		log.u_bbr.flex1 = rack->rc_rack_tmr_std_based;
2615 		log.u_bbr.flex1 <<= 1;
2616 		log.u_bbr.flex1 |= rack->rc_rack_use_dsack;
2617 		log.u_bbr.flex1 <<= 1;
2618 		log.u_bbr.flex1 |= rack->rc_dsack_round_seen;
2619 		log.u_bbr.flex2 = rack->r_ctl.dsack_round_end;
2620 		log.u_bbr.flex3 = rack->r_ctl.num_dsack;
2621 		log.u_bbr.flex4 = flex4;
2622 		log.u_bbr.flex5 = flex5;
2623 		log.u_bbr.flex6 = flex6;
2624 		log.u_bbr.flex7 = rack->r_ctl.dsack_persist;
2625 		log.u_bbr.flex8 = mod;
2626 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2627 		log.u_bbr.epoch = rack->r_ctl.current_round;
2628 		log.u_bbr.lt_epoch = rack->r_ctl.rc_considered_lost;
2629 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2630 		    &rack->rc_inp->inp_socket->so_rcv,
2631 		    &rack->rc_inp->inp_socket->so_snd,
2632 		    RACK_DSACK_HANDLING, 0,
2633 		    0, &log, false, &tv);
2634 	}
2635 }
2636 
2637 static void
rack_log_hdwr_pacing(struct tcp_rack * rack,uint64_t rate,uint64_t hw_rate,int line,int error,uint16_t mod)2638 rack_log_hdwr_pacing(struct tcp_rack *rack,
2639 		     uint64_t rate, uint64_t hw_rate, int line,
2640 		     int error, uint16_t mod)
2641 {
2642 	if (tcp_bblogging_on(rack->rc_tp)) {
2643 		union tcp_log_stackspecific log;
2644 		struct timeval tv;
2645 		const struct ifnet *ifp;
2646 
2647 		memset(&log, 0, sizeof(log));
2648 		log.u_bbr.flex1 = ((hw_rate >> 32) & 0x00000000ffffffff);
2649 		log.u_bbr.flex2 = (hw_rate & 0x00000000ffffffff);
2650 		if (rack->r_ctl.crte) {
2651 			ifp = rack->r_ctl.crte->ptbl->rs_ifp;
2652 		} else if (rack->rc_inp->inp_route.ro_nh &&
2653 			   rack->rc_inp->inp_route.ro_nh->nh_ifp) {
2654 			ifp = rack->rc_inp->inp_route.ro_nh->nh_ifp;
2655 		} else
2656 			ifp = NULL;
2657 		if (ifp) {
2658 			log.u_bbr.flex3 = (((uint64_t)ifp  >> 32) & 0x00000000ffffffff);
2659 			log.u_bbr.flex4 = ((uint64_t)ifp & 0x00000000ffffffff);
2660 		}
2661 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2662 		log.u_bbr.bw_inuse = rate;
2663 		log.u_bbr.flex5 = line;
2664 		log.u_bbr.flex6 = error;
2665 		log.u_bbr.flex7 = mod;
2666 		log.u_bbr.applimited = rack->r_ctl.rc_pace_max_segs;
2667 		log.u_bbr.flex8 = rack->use_fixed_rate;
2668 		log.u_bbr.flex8 <<= 1;
2669 		log.u_bbr.flex8 |= rack->rack_hdrw_pacing;
2670 		log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
2671 		log.u_bbr.delRate = rack->r_ctl.crte_prev_rate;
2672 		if (rack->r_ctl.crte)
2673 			log.u_bbr.cur_del_rate = rack->r_ctl.crte->rate;
2674 		else
2675 			log.u_bbr.cur_del_rate = 0;
2676 		log.u_bbr.rttProp = rack->r_ctl.last_hw_bw_req;
2677 		log.u_bbr.epoch = rack->r_ctl.current_round;
2678 		log.u_bbr.lt_epoch = rack->r_ctl.rc_considered_lost;
2679 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2680 		    &rack->rc_inp->inp_socket->so_rcv,
2681 		    &rack->rc_inp->inp_socket->so_snd,
2682 		    BBR_LOG_HDWR_PACE, 0,
2683 		    0, &log, false, &tv);
2684 	}
2685 }
2686 
2687 static uint64_t
rack_get_output_bw(struct tcp_rack * rack,uint64_t bw,struct rack_sendmap * rsm,int * capped)2688 rack_get_output_bw(struct tcp_rack *rack, uint64_t bw, struct rack_sendmap *rsm, int *capped)
2689 {
2690 	/*
2691 	 * We allow rack_per_of_gp_xx to dictate our bw rate we want.
2692 	 */
2693 	uint64_t bw_est, high_rate;
2694 	uint64_t gain;
2695 
2696 	gain = (uint64_t)rack_get_output_gain(rack, rsm);
2697 	bw_est = bw * gain;
2698 	bw_est /= (uint64_t)100;
2699 	/* Never fall below the minimum (def 64kbps) */
2700 	if (bw_est < RACK_MIN_BW)
2701 		bw_est = RACK_MIN_BW;
2702 	if (rack->r_rack_hw_rate_caps) {
2703 		/* Rate caps are in place */
2704 		if (rack->r_ctl.crte != NULL) {
2705 			/* We have a hdwr rate already */
2706 			high_rate = tcp_hw_highest_rate(rack->r_ctl.crte);
2707 			if (bw_est >= high_rate) {
2708 				/* We are capping bw at the highest rate table entry */
2709 				if (rack_hw_rate_cap_per &&
2710 				    (((high_rate * (100 + rack_hw_rate_cap_per)) / 100) < bw_est)) {
2711 					rack->r_rack_hw_rate_caps = 0;
2712 					goto done;
2713 				}
2714 				rack_log_hdwr_pacing(rack,
2715 						     bw_est, high_rate, __LINE__,
2716 						     0, 3);
2717 				bw_est = high_rate;
2718 				if (capped)
2719 					*capped = 1;
2720 			}
2721 		} else if ((rack->rack_hdrw_pacing == 0) &&
2722 			   (rack->rack_hdw_pace_ena) &&
2723 			   (rack->rack_attempt_hdwr_pace == 0) &&
2724 			   (rack->rc_inp->inp_route.ro_nh != NULL) &&
2725 			   (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
2726 			/*
2727 			 * Special case, we have not yet attempted hardware
2728 			 * pacing, and yet we may, when we do, find out if we are
2729 			 * above the highest rate. We need to know the maxbw for the interface
2730 			 * in question (if it supports ratelimiting). We get back
2731 			 * a 0, if the interface is not found in the RL lists.
2732 			 */
2733 			high_rate = tcp_hw_highest_rate_ifp(rack->rc_inp->inp_route.ro_nh->nh_ifp, rack->rc_inp);
2734 			if (high_rate) {
2735 				/* Yep, we have a rate is it above this rate? */
2736 				if (bw_est > high_rate) {
2737 					bw_est = high_rate;
2738 					if (capped)
2739 						*capped = 1;
2740 				}
2741 			}
2742 		}
2743 	}
2744 done:
2745 	return (bw_est);
2746 }
2747 
2748 static void
rack_log_retran_reason(struct tcp_rack * rack,struct rack_sendmap * rsm,uint32_t tsused,uint32_t thresh,int mod)2749 rack_log_retran_reason(struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t tsused, uint32_t thresh, int mod)
2750 {
2751 	if (tcp_bblogging_on(rack->rc_tp)) {
2752 		union tcp_log_stackspecific log;
2753 		struct timeval tv;
2754 
2755 		if ((mod != 1) && (rack_verbose_logging == 0))  {
2756 			/*
2757 			 * We get 3 values currently for mod
2758 			 * 1 - We are retransmitting and this tells the reason.
2759 			 * 2 - We are clearing a dup-ack count.
2760 			 * 3 - We are incrementing a dup-ack count.
2761 			 *
2762 			 * The clear/increment are only logged
2763 			 * if you have BBverbose on.
2764 			 */
2765 			return;
2766 		}
2767 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2768 		log.u_bbr.flex1 = tsused;
2769 		log.u_bbr.flex2 = thresh;
2770 		log.u_bbr.flex3 = rsm->r_flags;
2771 		log.u_bbr.flex4 = rsm->r_dupack;
2772 		log.u_bbr.flex5 = rsm->r_start;
2773 		log.u_bbr.flex6 = rsm->r_end;
2774 		log.u_bbr.flex8 = mod;
2775 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2776 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2777 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2778 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2779 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2780 		log.u_bbr.pacing_gain = rack->r_must_retran;
2781 		log.u_bbr.epoch = rack->r_ctl.current_round;
2782 		log.u_bbr.lt_epoch = rack->r_ctl.rc_considered_lost;
2783 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2784 		    &rack->rc_inp->inp_socket->so_rcv,
2785 		    &rack->rc_inp->inp_socket->so_snd,
2786 		    BBR_LOG_SETTINGS_CHG, 0,
2787 		    0, &log, false, &tv);
2788 	}
2789 }
2790 
2791 static void
rack_log_to_start(struct tcp_rack * rack,uint32_t cts,uint32_t to,int32_t slot,uint8_t which)2792 rack_log_to_start(struct tcp_rack *rack, uint32_t cts, uint32_t to, int32_t slot, uint8_t which)
2793 {
2794 	if (tcp_bblogging_on(rack->rc_tp)) {
2795 		union tcp_log_stackspecific log;
2796 		struct timeval tv;
2797 
2798 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2799 		log.u_bbr.flex1 = rack->rc_tp->t_srtt;
2800 		log.u_bbr.flex2 = to;
2801 		log.u_bbr.flex3 = rack->r_ctl.rc_hpts_flags;
2802 		log.u_bbr.flex4 = slot;
2803 		log.u_bbr.flex5 = rack->rc_tp->t_hpts_slot;
2804 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2805 		log.u_bbr.flex7 = rack->rc_in_persist;
2806 		log.u_bbr.flex8 = which;
2807 		if (rack->rack_no_prr)
2808 			log.u_bbr.pkts_out = 0;
2809 		else
2810 			log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
2811 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2812 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2813 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2814 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2815 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2816 		log.u_bbr.pacing_gain = rack->r_must_retran;
2817 		log.u_bbr.cwnd_gain = rack->rack_deferred_inited;
2818 		log.u_bbr.pkt_epoch = rack->rc_has_collapsed;
2819 		log.u_bbr.lt_epoch = rack->rc_tp->t_rxtshift;
2820 		log.u_bbr.lost = rack_rto_min;
2821 		log.u_bbr.epoch = rack->r_ctl.roundends;
2822 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
2823 		log.u_bbr.bw_inuse <<= 32;
2824 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
2825 		log.u_bbr.applimited = rack->rc_tp->t_flags2;
2826 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2827 		    &rack->rc_inp->inp_socket->so_rcv,
2828 		    &rack->rc_inp->inp_socket->so_snd,
2829 		    BBR_LOG_TIMERSTAR, 0,
2830 		    0, &log, false, &tv);
2831 	}
2832 }
2833 
2834 static void
rack_log_to_event(struct tcp_rack * rack,int32_t to_num,struct rack_sendmap * rsm)2835 rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm)
2836 {
2837 	if (tcp_bblogging_on(rack->rc_tp)) {
2838 		union tcp_log_stackspecific log;
2839 		struct timeval tv;
2840 
2841 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2842 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2843 		log.u_bbr.flex8 = to_num;
2844 		log.u_bbr.flex1 = rack->r_ctl.rc_rack_min_rtt;
2845 		log.u_bbr.flex2 = rack->rc_rack_rtt;
2846 		if (rsm == NULL)
2847 			log.u_bbr.flex3 = 0;
2848 		else
2849 			log.u_bbr.flex3 = rsm->r_end - rsm->r_start;
2850 		if (rack->rack_no_prr)
2851 			log.u_bbr.flex5 = 0;
2852 		else
2853 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2854 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2855 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2856 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2857 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2858 		log.u_bbr.pacing_gain = rack->r_must_retran;
2859 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
2860 		log.u_bbr.bw_inuse <<= 32;
2861 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
2862 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2863 		    &rack->rc_inp->inp_socket->so_rcv,
2864 		    &rack->rc_inp->inp_socket->so_snd,
2865 		    BBR_LOG_RTO, 0,
2866 		    0, &log, false, &tv);
2867 	}
2868 }
2869 
2870 static void
rack_log_map_chg(struct tcpcb * tp,struct tcp_rack * rack,struct rack_sendmap * prev,struct rack_sendmap * rsm,struct rack_sendmap * next,int flag,uint32_t th_ack,int line)2871 rack_log_map_chg(struct tcpcb *tp, struct tcp_rack *rack,
2872 		 struct rack_sendmap *prev,
2873 		 struct rack_sendmap *rsm,
2874 		 struct rack_sendmap *next,
2875 		 int flag, uint32_t th_ack, int line)
2876 {
2877 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
2878 		union tcp_log_stackspecific log;
2879 		struct timeval tv;
2880 
2881 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2882 		log.u_bbr.flex8 = flag;
2883 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2884 		log.u_bbr.cur_del_rate = (uint64_t)prev;
2885 		log.u_bbr.delRate = (uint64_t)rsm;
2886 		log.u_bbr.rttProp = (uint64_t)next;
2887 		log.u_bbr.flex7 = 0;
2888 		if (prev) {
2889 			log.u_bbr.flex1 = prev->r_start;
2890 			log.u_bbr.flex2 = prev->r_end;
2891 			log.u_bbr.flex7 |= 0x4;
2892 		}
2893 		if (rsm) {
2894 			log.u_bbr.flex3 = rsm->r_start;
2895 			log.u_bbr.flex4 = rsm->r_end;
2896 			log.u_bbr.flex7 |= 0x2;
2897 		}
2898 		if (next) {
2899 			log.u_bbr.flex5 = next->r_start;
2900 			log.u_bbr.flex6 = next->r_end;
2901 			log.u_bbr.flex7 |= 0x1;
2902 		}
2903 		log.u_bbr.applimited = line;
2904 		log.u_bbr.pkts_out = th_ack;
2905 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2906 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2907 		if (rack->rack_no_prr)
2908 			log.u_bbr.lost = 0;
2909 		else
2910 			log.u_bbr.lost = rack->r_ctl.rc_prr_sndcnt;
2911 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
2912 		log.u_bbr.bw_inuse <<= 32;
2913 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
2914 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2915 		    &rack->rc_inp->inp_socket->so_rcv,
2916 		    &rack->rc_inp->inp_socket->so_snd,
2917 		    TCP_LOG_MAPCHG, 0,
2918 		    0, &log, false, &tv);
2919 	}
2920 }
2921 
2922 static void
rack_log_rtt_upd(struct tcpcb * tp,struct tcp_rack * rack,uint32_t t,uint32_t len,struct rack_sendmap * rsm,int conf)2923 rack_log_rtt_upd(struct tcpcb *tp, struct tcp_rack *rack, uint32_t t, uint32_t len,
2924 		 struct rack_sendmap *rsm, int conf)
2925 {
2926 	if (tcp_bblogging_on(tp)) {
2927 		union tcp_log_stackspecific log;
2928 		struct timeval tv;
2929 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2930 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2931 		log.u_bbr.flex1 = t;
2932 		log.u_bbr.flex2 = len;
2933 		log.u_bbr.flex3 = rack->r_ctl.rc_rack_min_rtt;
2934 		log.u_bbr.flex4 = rack->r_ctl.rack_rs.rs_rtt_lowest;
2935 		log.u_bbr.flex5 = rack->r_ctl.rack_rs.rs_rtt_highest;
2936 		log.u_bbr.flex6 = rack->r_ctl.rack_rs.rs_us_rtrcnt;
2937 		log.u_bbr.flex7 = conf;
2938 		log.u_bbr.rttProp = (uint64_t)rack->r_ctl.rack_rs.rs_rtt_tot;
2939 		log.u_bbr.flex8 = rack->r_ctl.rc_rate_sample_method;
2940 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2941 		log.u_bbr.delivered = rack->r_ctl.rack_rs.rs_us_rtrcnt;
2942 		log.u_bbr.pkts_out = rack->r_ctl.rack_rs.rs_flags;
2943 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2944 		if (rsm) {
2945 			log.u_bbr.pkt_epoch = rsm->r_start;
2946 			log.u_bbr.lost = rsm->r_end;
2947 			log.u_bbr.cwnd_gain = rsm->r_rtr_cnt;
2948 			/* We loose any upper of the 24 bits */
2949 			log.u_bbr.pacing_gain = (uint16_t)rsm->r_flags;
2950 		} else {
2951 			/* Its a SYN */
2952 			log.u_bbr.pkt_epoch = rack->rc_tp->iss;
2953 			log.u_bbr.lost = 0;
2954 			log.u_bbr.cwnd_gain = 0;
2955 			log.u_bbr.pacing_gain = 0;
2956 		}
2957 		/* Write out general bits of interest rrs here */
2958 		log.u_bbr.use_lt_bw = rack->rc_highly_buffered;
2959 		log.u_bbr.use_lt_bw <<= 1;
2960 		log.u_bbr.use_lt_bw |= rack->forced_ack;
2961 		log.u_bbr.use_lt_bw <<= 1;
2962 		log.u_bbr.use_lt_bw |= rack->rc_gp_dyn_mul;
2963 		log.u_bbr.use_lt_bw <<= 1;
2964 		log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
2965 		log.u_bbr.use_lt_bw <<= 1;
2966 		log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
2967 		log.u_bbr.use_lt_bw <<= 1;
2968 		log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
2969 		log.u_bbr.use_lt_bw <<= 1;
2970 		log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
2971 		log.u_bbr.use_lt_bw <<= 1;
2972 		log.u_bbr.use_lt_bw |= rack->rc_dragged_bottom;
2973 		log.u_bbr.applimited = rack->r_ctl.rc_target_probertt_flight;
2974 		log.u_bbr.epoch = rack->r_ctl.rc_time_probertt_starts;
2975 		log.u_bbr.lt_epoch = rack->r_ctl.rc_time_probertt_entered;
2976 		log.u_bbr.cur_del_rate = rack->r_ctl.rc_lower_rtt_us_cts;
2977 		log.u_bbr.delRate = rack->r_ctl.rc_gp_srtt;
2978 		log.u_bbr.bw_inuse = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
2979 		log.u_bbr.bw_inuse <<= 32;
2980 		if (rsm)
2981 			log.u_bbr.bw_inuse |= ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]);
2982 		TCP_LOG_EVENTP(tp, NULL,
2983 		    &rack->rc_inp->inp_socket->so_rcv,
2984 		    &rack->rc_inp->inp_socket->so_snd,
2985 		    BBR_LOG_BBRRTT, 0,
2986 		    0, &log, false, &tv);
2987 
2988 
2989 	}
2990 }
2991 
2992 static void
rack_log_rtt_sample(struct tcp_rack * rack,uint32_t rtt)2993 rack_log_rtt_sample(struct tcp_rack *rack, uint32_t rtt)
2994 {
2995 	/*
2996 	 * Log the rtt sample we are
2997 	 * applying to the srtt algorithm in
2998 	 * useconds.
2999 	 */
3000 	if (tcp_bblogging_on(rack->rc_tp)) {
3001 		union tcp_log_stackspecific log;
3002 		struct timeval tv;
3003 
3004 		/* Convert our ms to a microsecond */
3005 		memset(&log, 0, sizeof(log));
3006 		log.u_bbr.flex1 = rtt;
3007 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
3008 		log.u_bbr.flex7 = 1;
3009 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3010 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3011 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
3012 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
3013 		log.u_bbr.pacing_gain = rack->r_must_retran;
3014 		/*
3015 		 * We capture in delRate the upper 32 bits as
3016 		 * the confidence level we had declared, and the
3017 		 * lower 32 bits as the actual RTT using the arrival
3018 		 * timestamp.
3019 		 */
3020 		log.u_bbr.delRate = rack->r_ctl.rack_rs.confidence;
3021 		log.u_bbr.delRate <<= 32;
3022 		log.u_bbr.delRate |= rack->r_ctl.rack_rs.rs_us_rtt;
3023 		/* Lets capture all the things that make up t_rtxcur */
3024 		log.u_bbr.applimited = rack_rto_min;
3025 		log.u_bbr.epoch = rack_rto_max;
3026 		log.u_bbr.lt_epoch = rack->r_ctl.timer_slop;
3027 		log.u_bbr.lost = rack_rto_min;
3028 		log.u_bbr.pkt_epoch = TICKS_2_USEC(tcp_rexmit_slop);
3029 		log.u_bbr.rttProp = RACK_REXMTVAL(rack->rc_tp);
3030 		log.u_bbr.bw_inuse = rack->r_ctl.act_rcv_time.tv_sec;
3031 		log.u_bbr.bw_inuse *= HPTS_USEC_IN_SEC;
3032 		log.u_bbr.bw_inuse += rack->r_ctl.act_rcv_time.tv_usec;
3033 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3034 		    &rack->rc_inp->inp_socket->so_rcv,
3035 		    &rack->rc_inp->inp_socket->so_snd,
3036 		    TCP_LOG_RTT, 0,
3037 		    0, &log, false, &tv);
3038 	}
3039 }
3040 
3041 static void
rack_log_rtt_sample_calc(struct tcp_rack * rack,uint32_t rtt,uint32_t send_time,uint32_t ack_time,int where)3042 rack_log_rtt_sample_calc(struct tcp_rack *rack, uint32_t rtt, uint32_t send_time, uint32_t ack_time, int where)
3043 {
3044 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
3045 		union tcp_log_stackspecific log;
3046 		struct timeval tv;
3047 
3048 		/* Convert our ms to a microsecond */
3049 		memset(&log, 0, sizeof(log));
3050 		log.u_bbr.flex1 = rtt;
3051 		log.u_bbr.flex2 = send_time;
3052 		log.u_bbr.flex3 = ack_time;
3053 		log.u_bbr.flex4 = where;
3054 		log.u_bbr.flex7 = 2;
3055 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3056 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
3057 		log.u_bbr.bw_inuse <<= 32;
3058 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
3059 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3060 		    &rack->rc_inp->inp_socket->so_rcv,
3061 		    &rack->rc_inp->inp_socket->so_snd,
3062 		    TCP_LOG_RTT, 0,
3063 		    0, &log, false, &tv);
3064 	}
3065 }
3066 
3067 
3068 static void
rack_log_rtt_sendmap(struct tcp_rack * rack,uint32_t idx,uint64_t tsv,uint32_t tsecho)3069 rack_log_rtt_sendmap(struct tcp_rack *rack, uint32_t idx, uint64_t tsv, uint32_t tsecho)
3070 {
3071 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
3072 		union tcp_log_stackspecific log;
3073 		struct timeval tv;
3074 
3075 		/* Convert our ms to a microsecond */
3076 		memset(&log, 0, sizeof(log));
3077 		log.u_bbr.flex1 = idx;
3078 		log.u_bbr.flex2 = rack_ts_to_msec(tsv);
3079 		log.u_bbr.flex3 = tsecho;
3080 		log.u_bbr.flex7 = 3;
3081 		log.u_bbr.rttProp = tsv;
3082 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3083 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
3084 		log.u_bbr.bw_inuse <<= 32;
3085 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
3086 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3087 		    &rack->rc_inp->inp_socket->so_rcv,
3088 		    &rack->rc_inp->inp_socket->so_snd,
3089 		    TCP_LOG_RTT, 0,
3090 		    0, &log, false, &tv);
3091 	}
3092 }
3093 
3094 
3095 static inline void
rack_log_progress_event(struct tcp_rack * rack,struct tcpcb * tp,uint32_t tick,int event,int line)3096 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick,  int event, int line)
3097 {
3098 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
3099 		union tcp_log_stackspecific log;
3100 		struct timeval tv;
3101 
3102 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3103 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
3104 		log.u_bbr.flex1 = line;
3105 		log.u_bbr.flex2 = tick;
3106 		log.u_bbr.flex3 = tp->t_maxunacktime;
3107 		log.u_bbr.flex4 = tp->t_acktime;
3108 		log.u_bbr.flex8 = event;
3109 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3110 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3111 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
3112 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
3113 		log.u_bbr.pacing_gain = rack->r_must_retran;
3114 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
3115 		log.u_bbr.bw_inuse <<= 32;
3116 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
3117 		TCP_LOG_EVENTP(tp, NULL,
3118 		    &rack->rc_inp->inp_socket->so_rcv,
3119 		    &rack->rc_inp->inp_socket->so_snd,
3120 		    BBR_LOG_PROGRESS, 0,
3121 		    0, &log, false, &tv);
3122 	}
3123 }
3124 
3125 static void
rack_log_type_bbrsnd(struct tcp_rack * rack,uint32_t len,uint32_t slot,uint32_t cts,struct timeval * tv,int line)3126 rack_log_type_bbrsnd(struct tcp_rack *rack, uint32_t len, uint32_t slot, uint32_t cts, struct timeval *tv, int line)
3127 {
3128 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
3129 		union tcp_log_stackspecific log;
3130 
3131 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3132 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
3133 		log.u_bbr.flex1 = slot;
3134 		if (rack->rack_no_prr)
3135 			log.u_bbr.flex2 = 0;
3136 		else
3137 			log.u_bbr.flex2 = rack->r_ctl.rc_prr_sndcnt;
3138 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
3139 		log.u_bbr.flex6 = line;
3140 		log.u_bbr.flex7 = (0x0000ffff & rack->r_ctl.rc_hpts_flags);
3141 		log.u_bbr.flex8 = rack->rc_in_persist;
3142 		log.u_bbr.timeStamp = cts;
3143 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3144 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
3145 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
3146 		log.u_bbr.pacing_gain = rack->r_must_retran;
3147 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3148 		    &rack->rc_inp->inp_socket->so_rcv,
3149 		    &rack->rc_inp->inp_socket->so_snd,
3150 		    BBR_LOG_BBRSND, 0,
3151 		    0, &log, false, tv);
3152 	}
3153 }
3154 
3155 static void
rack_log_doseg_done(struct tcp_rack * rack,uint32_t cts,int32_t nxt_pkt,int32_t did_out,int way_out,int nsegs)3156 rack_log_doseg_done(struct tcp_rack *rack, uint32_t cts, int32_t nxt_pkt, int32_t did_out, int way_out, int nsegs)
3157 {
3158 	if (tcp_bblogging_on(rack->rc_tp)) {
3159 		union tcp_log_stackspecific log;
3160 		struct timeval tv;
3161 
3162 		memset(&log, 0, sizeof(log));
3163 		log.u_bbr.flex1 = did_out;
3164 		log.u_bbr.flex2 = nxt_pkt;
3165 		log.u_bbr.flex3 = way_out;
3166 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
3167 		if (rack->rack_no_prr)
3168 			log.u_bbr.flex5 = 0;
3169 		else
3170 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
3171 		log.u_bbr.flex6 = nsegs;
3172 		log.u_bbr.applimited = rack->r_ctl.rc_pace_min_segs;
3173 		log.u_bbr.flex7 = rack->rc_ack_can_sendout_data;	/* Do we have ack-can-send set */
3174 		log.u_bbr.flex7 <<= 1;
3175 		log.u_bbr.flex7 |= rack->r_fast_output;	/* is fast output primed */
3176 		log.u_bbr.flex7 <<= 1;
3177 		log.u_bbr.flex7 |= rack->r_wanted_output;	/* Do we want output */
3178 		log.u_bbr.flex8 = rack->rc_in_persist;
3179 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
3180 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3181 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3182 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
3183 		log.u_bbr.use_lt_bw <<= 1;
3184 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
3185 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
3186 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
3187 		log.u_bbr.pacing_gain = rack->r_must_retran;
3188 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
3189 		log.u_bbr.bw_inuse <<= 32;
3190 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
3191 		log.u_bbr.epoch = rack->rc_inp->inp_socket->so_snd.sb_hiwat;
3192 		log.u_bbr.lt_epoch = rack->rc_inp->inp_socket->so_rcv.sb_hiwat;
3193 		log.u_bbr.lost = rack->rc_tp->t_srtt;
3194 		log.u_bbr.pkt_epoch = rack->rc_tp->rfbuf_cnt;
3195 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3196 		    &rack->rc_inp->inp_socket->so_rcv,
3197 		    &rack->rc_inp->inp_socket->so_snd,
3198 		    BBR_LOG_DOSEG_DONE, 0,
3199 		    0, &log, false, &tv);
3200 	}
3201 }
3202 
3203 static void
rack_log_type_pacing_sizes(struct tcpcb * tp,struct tcp_rack * rack,uint32_t arg1,uint32_t arg2,uint32_t arg3,uint8_t frm)3204 rack_log_type_pacing_sizes(struct tcpcb *tp, struct tcp_rack *rack, uint32_t arg1, uint32_t arg2, uint32_t arg3, uint8_t frm)
3205 {
3206 	if (tcp_bblogging_on(rack->rc_tp)) {
3207 		union tcp_log_stackspecific log;
3208 		struct timeval tv;
3209 
3210 		memset(&log, 0, sizeof(log));
3211 		log.u_bbr.flex1 = rack->r_ctl.rc_pace_min_segs;
3212 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
3213 		log.u_bbr.flex4 = arg1;
3214 		log.u_bbr.flex5 = arg2;
3215 		log.u_bbr.flex7 = rack->r_ctl.rc_user_set_min_segs;
3216 		log.u_bbr.flex6 = arg3;
3217 		log.u_bbr.flex8 = frm;
3218 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3219 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3220 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
3221 		log.u_bbr.applimited = rack->r_ctl.rc_sacked;
3222 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
3223 		log.u_bbr.pacing_gain = rack->r_must_retran;
3224 		TCP_LOG_EVENTP(tp, NULL, &tptosocket(tp)->so_rcv,
3225 		    &tptosocket(tp)->so_snd,
3226 		    TCP_HDWR_PACE_SIZE, 0, 0, &log, false, &tv);
3227 	}
3228 }
3229 
3230 static void
rack_log_type_just_return(struct tcp_rack * rack,uint32_t cts,uint32_t tlen,uint32_t slot,uint8_t hpts_calling,int reason,uint32_t cwnd_to_use)3231 rack_log_type_just_return(struct tcp_rack *rack, uint32_t cts, uint32_t tlen, uint32_t slot,
3232 			  uint8_t hpts_calling, int reason, uint32_t cwnd_to_use)
3233 {
3234 	if (tcp_bblogging_on(rack->rc_tp)) {
3235 		union tcp_log_stackspecific log;
3236 		struct timeval tv;
3237 
3238 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3239 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
3240 		log.u_bbr.flex1 = slot;
3241 		log.u_bbr.flex2 = rack->r_ctl.rc_hpts_flags;
3242 		log.u_bbr.flex4 = reason;
3243 		if (rack->rack_no_prr)
3244 			log.u_bbr.flex5 = 0;
3245 		else
3246 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
3247 		log.u_bbr.flex7 = hpts_calling;
3248 		log.u_bbr.flex8 = rack->rc_in_persist;
3249 		log.u_bbr.lt_epoch = cwnd_to_use;
3250 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3251 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3252 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
3253 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
3254 		log.u_bbr.pacing_gain = rack->r_must_retran;
3255 		log.u_bbr.cwnd_gain = rack->rc_has_collapsed;
3256 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
3257 		log.u_bbr.bw_inuse <<= 32;
3258 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
3259 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3260 		    &rack->rc_inp->inp_socket->so_rcv,
3261 		    &rack->rc_inp->inp_socket->so_snd,
3262 		    BBR_LOG_JUSTRET, 0,
3263 		    tlen, &log, false, &tv);
3264 	}
3265 }
3266 
3267 static void
rack_log_to_cancel(struct tcp_rack * rack,int32_t hpts_removed,int line,uint32_t us_cts,struct timeval * tv,uint32_t flags_on_entry)3268 rack_log_to_cancel(struct tcp_rack *rack, int32_t hpts_removed, int line, uint32_t us_cts,
3269 		   struct timeval *tv, uint32_t flags_on_entry)
3270 {
3271 	if (tcp_bblogging_on(rack->rc_tp)) {
3272 		union tcp_log_stackspecific log;
3273 
3274 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3275 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
3276 		log.u_bbr.flex1 = line;
3277 		log.u_bbr.flex2 = rack->r_ctl.rc_last_output_to;
3278 		log.u_bbr.flex3 = flags_on_entry;
3279 		log.u_bbr.flex4 = us_cts;
3280 		if (rack->rack_no_prr)
3281 			log.u_bbr.flex5 = 0;
3282 		else
3283 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
3284 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
3285 		log.u_bbr.flex7 = hpts_removed;
3286 		log.u_bbr.flex8 = 1;
3287 		log.u_bbr.applimited = rack->r_ctl.rc_hpts_flags;
3288 		log.u_bbr.timeStamp = us_cts;
3289 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3290 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
3291 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
3292 		log.u_bbr.pacing_gain = rack->r_must_retran;
3293 		log.u_bbr.bw_inuse = rack->r_ctl.current_round;
3294 		log.u_bbr.bw_inuse <<= 32;
3295 		log.u_bbr.bw_inuse |= rack->r_ctl.rc_considered_lost;
3296 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3297 		    &rack->rc_inp->inp_socket->so_rcv,
3298 		    &rack->rc_inp->inp_socket->so_snd,
3299 		    BBR_LOG_TIMERCANC, 0,
3300 		    0, &log, false, tv);
3301 	}
3302 }
3303 
3304 static void
rack_log_alt_to_to_cancel(struct tcp_rack * rack,uint32_t flex1,uint32_t flex2,uint32_t flex3,uint32_t flex4,uint32_t flex5,uint32_t flex6,uint16_t flex7,uint8_t mod)3305 rack_log_alt_to_to_cancel(struct tcp_rack *rack,
3306 			  uint32_t flex1, uint32_t flex2,
3307 			  uint32_t flex3, uint32_t flex4,
3308 			  uint32_t flex5, uint32_t flex6,
3309 			  uint16_t flex7, uint8_t mod)
3310 {
3311 	if (tcp_bblogging_on(rack->rc_tp)) {
3312 		union tcp_log_stackspecific log;
3313 		struct timeval tv;
3314 
3315 		if (mod == 1) {
3316 			/* No you can't use 1, its for the real to cancel */
3317 			return;
3318 		}
3319 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3320 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3321 		log.u_bbr.flex1 = flex1;
3322 		log.u_bbr.flex2 = flex2;
3323 		log.u_bbr.flex3 = flex3;
3324 		log.u_bbr.flex4 = flex4;
3325 		log.u_bbr.flex5 = flex5;
3326 		log.u_bbr.flex6 = flex6;
3327 		log.u_bbr.flex7 = flex7;
3328 		log.u_bbr.flex8 = mod;
3329 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3330 		    &rack->rc_inp->inp_socket->so_rcv,
3331 		    &rack->rc_inp->inp_socket->so_snd,
3332 		    BBR_LOG_TIMERCANC, 0,
3333 		    0, &log, false, &tv);
3334 	}
3335 }
3336 
3337 static void
rack_log_to_processing(struct tcp_rack * rack,uint32_t cts,int32_t ret,int32_t timers)3338 rack_log_to_processing(struct tcp_rack *rack, uint32_t cts, int32_t ret, int32_t timers)
3339 {
3340 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
3341 		union tcp_log_stackspecific log;
3342 		struct timeval tv;
3343 
3344 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3345 		log.u_bbr.flex1 = timers;
3346 		log.u_bbr.flex2 = ret;
3347 		log.u_bbr.flex3 = rack->r_ctl.rc_timer_exp;
3348 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
3349 		log.u_bbr.flex5 = cts;
3350 		if (rack->rack_no_prr)
3351 			log.u_bbr.flex6 = 0;
3352 		else
3353 			log.u_bbr.flex6 = rack->r_ctl.rc_prr_sndcnt;
3354 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
3355 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
3356 		log.u_bbr.pacing_gain = rack->r_must_retran;
3357 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3358 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3359 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3360 		    &rack->rc_inp->inp_socket->so_rcv,
3361 		    &rack->rc_inp->inp_socket->so_snd,
3362 		    BBR_LOG_TO_PROCESS, 0,
3363 		    0, &log, false, &tv);
3364 	}
3365 }
3366 
3367 static void
rack_log_to_prr(struct tcp_rack * rack,int frm,int orig_cwnd,int line)3368 rack_log_to_prr(struct tcp_rack *rack, int frm, int orig_cwnd, int line)
3369 {
3370 	if (tcp_bblogging_on(rack->rc_tp)) {
3371 		union tcp_log_stackspecific log;
3372 		struct timeval tv;
3373 
3374 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3375 		log.u_bbr.flex1 = rack->r_ctl.rc_prr_out;
3376 		log.u_bbr.flex2 = rack->r_ctl.rc_prr_recovery_fs;
3377 		if (rack->rack_no_prr)
3378 			log.u_bbr.flex3 = 0;
3379 		else
3380 			log.u_bbr.flex3 = rack->r_ctl.rc_prr_sndcnt;
3381 		log.u_bbr.flex4 = rack->r_ctl.rc_prr_delivered;
3382 		log.u_bbr.flex5 = rack->r_ctl.rc_sacked;
3383 		log.u_bbr.flex6 = rack->r_ctl.rc_holes_rxt;
3384 		log.u_bbr.flex7 = line;
3385 		log.u_bbr.flex8 = frm;
3386 		log.u_bbr.pkts_out = orig_cwnd;
3387 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3388 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3389 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
3390 		log.u_bbr.use_lt_bw <<= 1;
3391 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
3392 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3393 		    &rack->rc_inp->inp_socket->so_rcv,
3394 		    &rack->rc_inp->inp_socket->so_snd,
3395 		    BBR_LOG_BBRUPD, 0,
3396 		    0, &log, false, &tv);
3397 	}
3398 }
3399 
3400 static void
rack_counter_destroy(void)3401 rack_counter_destroy(void)
3402 {
3403 	counter_u64_free(rack_total_bytes);
3404 	counter_u64_free(rack_fto_send);
3405 	counter_u64_free(rack_fto_rsm_send);
3406 	counter_u64_free(rack_nfto_resend);
3407 	counter_u64_free(rack_hw_pace_init_fail);
3408 	counter_u64_free(rack_hw_pace_lost);
3409 	counter_u64_free(rack_non_fto_send);
3410 	counter_u64_free(rack_extended_rfo);
3411 	counter_u64_free(rack_ack_total);
3412 	counter_u64_free(rack_express_sack);
3413 	counter_u64_free(rack_sack_total);
3414 	counter_u64_free(rack_move_none);
3415 	counter_u64_free(rack_move_some);
3416 	counter_u64_free(rack_sack_attacks_detected);
3417 	counter_u64_free(rack_sack_attacks_reversed);
3418 	counter_u64_free(rack_sack_attacks_suspect);
3419 	counter_u64_free(rack_sack_used_next_merge);
3420 	counter_u64_free(rack_sack_used_prev_merge);
3421 	counter_u64_free(rack_tlp_tot);
3422 	counter_u64_free(rack_tlp_newdata);
3423 	counter_u64_free(rack_tlp_retran);
3424 	counter_u64_free(rack_tlp_retran_bytes);
3425 	counter_u64_free(rack_to_tot);
3426 	counter_u64_free(rack_saw_enobuf);
3427 	counter_u64_free(rack_saw_enobuf_hw);
3428 	counter_u64_free(rack_saw_enetunreach);
3429 	counter_u64_free(rack_hot_alloc);
3430 	counter_u64_free(tcp_policer_detected);
3431 	counter_u64_free(rack_to_alloc);
3432 	counter_u64_free(rack_to_alloc_hard);
3433 	counter_u64_free(rack_to_alloc_emerg);
3434 	counter_u64_free(rack_to_alloc_limited);
3435 	counter_u64_free(rack_alloc_limited_conns);
3436 	counter_u64_free(rack_split_limited);
3437 	counter_u64_free(rack_multi_single_eq);
3438 	counter_u64_free(rack_rxt_clamps_cwnd);
3439 	counter_u64_free(rack_rxt_clamps_cwnd_uniq);
3440 	counter_u64_free(rack_proc_non_comp_ack);
3441 	counter_u64_free(rack_sack_proc_all);
3442 	counter_u64_free(rack_sack_proc_restart);
3443 	counter_u64_free(rack_sack_proc_short);
3444 	counter_u64_free(rack_sack_skipped_acked);
3445 	counter_u64_free(rack_sack_splits);
3446 	counter_u64_free(rack_input_idle_reduces);
3447 	counter_u64_free(rack_collapsed_win);
3448 	counter_u64_free(rack_collapsed_win_rxt);
3449 	counter_u64_free(rack_collapsed_win_rxt_bytes);
3450 	counter_u64_free(rack_collapsed_win_seen);
3451 	counter_u64_free(rack_try_scwnd);
3452 	counter_u64_free(rack_persists_sends);
3453 	counter_u64_free(rack_persists_acks);
3454 	counter_u64_free(rack_persists_loss);
3455 	counter_u64_free(rack_persists_lost_ends);
3456 #ifdef INVARIANTS
3457 	counter_u64_free(rack_adjust_map_bw);
3458 #endif
3459 	COUNTER_ARRAY_FREE(rack_out_size, TCP_MSS_ACCT_SIZE);
3460 	COUNTER_ARRAY_FREE(rack_opts_arry, RACK_OPTS_SIZE);
3461 }
3462 
3463 static struct rack_sendmap *
rack_alloc(struct tcp_rack * rack)3464 rack_alloc(struct tcp_rack *rack)
3465 {
3466 	struct rack_sendmap *rsm;
3467 
3468 	/*
3469 	 * First get the top of the list it in
3470 	 * theory is the "hottest" rsm we have,
3471 	 * possibly just freed by ack processing.
3472 	 */
3473 	if (rack->rc_free_cnt > rack_free_cache) {
3474 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
3475 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
3476 		counter_u64_add(rack_hot_alloc, 1);
3477 		rack->rc_free_cnt--;
3478 		return (rsm);
3479 	}
3480 	/*
3481 	 * Once we get under our free cache we probably
3482 	 * no longer have a "hot" one available. Lets
3483 	 * get one from UMA.
3484 	 */
3485 	rsm = uma_zalloc(rack_zone, M_NOWAIT);
3486 	if (rsm) {
3487 		rack->r_ctl.rc_num_maps_alloced++;
3488 		counter_u64_add(rack_to_alloc, 1);
3489 		return (rsm);
3490 	}
3491 	/*
3492 	 * Dig in to our aux rsm's (the last two) since
3493 	 * UMA failed to get us one.
3494 	 */
3495 	if (rack->rc_free_cnt) {
3496 		counter_u64_add(rack_to_alloc_emerg, 1);
3497 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
3498 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
3499 		rack->rc_free_cnt--;
3500 		return (rsm);
3501 	}
3502 	return (NULL);
3503 }
3504 
3505 static struct rack_sendmap *
rack_alloc_full_limit(struct tcp_rack * rack)3506 rack_alloc_full_limit(struct tcp_rack *rack)
3507 {
3508 	if ((V_tcp_map_entries_limit > 0) &&
3509 	    (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
3510 		counter_u64_add(rack_to_alloc_limited, 1);
3511 		if (!rack->alloc_limit_reported) {
3512 			rack->alloc_limit_reported = 1;
3513 			counter_u64_add(rack_alloc_limited_conns, 1);
3514 		}
3515 		return (NULL);
3516 	}
3517 	return (rack_alloc(rack));
3518 }
3519 
3520 /* wrapper to allocate a sendmap entry, subject to a specific limit */
3521 static struct rack_sendmap *
rack_alloc_limit(struct tcp_rack * rack,uint8_t limit_type)3522 rack_alloc_limit(struct tcp_rack *rack, uint8_t limit_type)
3523 {
3524 	struct rack_sendmap *rsm;
3525 
3526 	if (limit_type) {
3527 		/* currently there is only one limit type */
3528 		if (rack->r_ctl.rc_split_limit > 0 &&
3529 		    rack->r_ctl.rc_num_split_allocs >= rack->r_ctl.rc_split_limit) {
3530 			counter_u64_add(rack_split_limited, 1);
3531 			if (!rack->alloc_limit_reported) {
3532 				rack->alloc_limit_reported = 1;
3533 				counter_u64_add(rack_alloc_limited_conns, 1);
3534 			}
3535 			return (NULL);
3536 		}
3537 	}
3538 
3539 	/* allocate and mark in the limit type, if set */
3540 	rsm = rack_alloc(rack);
3541 	if (rsm != NULL && limit_type) {
3542 		rsm->r_limit_type = limit_type;
3543 		rack->r_ctl.rc_num_split_allocs++;
3544 	}
3545 	return (rsm);
3546 }
3547 
3548 static void
rack_free_trim(struct tcp_rack * rack)3549 rack_free_trim(struct tcp_rack *rack)
3550 {
3551 	struct rack_sendmap *rsm;
3552 
3553 	/*
3554 	 * Free up all the tail entries until
3555 	 * we get our list down to the limit.
3556 	 */
3557 	while (rack->rc_free_cnt > rack_free_cache) {
3558 		rsm = TAILQ_LAST(&rack->r_ctl.rc_free, rack_head);
3559 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
3560 		rack->rc_free_cnt--;
3561 		rack->r_ctl.rc_num_maps_alloced--;
3562 		uma_zfree(rack_zone, rsm);
3563 	}
3564 }
3565 
3566 static void
rack_free(struct tcp_rack * rack,struct rack_sendmap * rsm)3567 rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm)
3568 {
3569 	if (rsm->r_flags & RACK_APP_LIMITED) {
3570 		if (rack->r_ctl.rc_app_limited_cnt > 0) {
3571 			rack->r_ctl.rc_app_limited_cnt--;
3572 		}
3573 	}
3574 	if (rsm->r_limit_type) {
3575 		/* currently there is only one limit type */
3576 		rack->r_ctl.rc_num_split_allocs--;
3577 	}
3578 	if (rsm == rack->r_ctl.rc_first_appl) {
3579 		rack->r_ctl.cleared_app_ack_seq = rsm->r_start + (rsm->r_end - rsm->r_start);
3580 		rack->r_ctl.cleared_app_ack = 1;
3581 		if (rack->r_ctl.rc_app_limited_cnt == 0)
3582 			rack->r_ctl.rc_first_appl = NULL;
3583 		else
3584 			rack->r_ctl.rc_first_appl = tqhash_find(rack->r_ctl.tqh, rsm->r_nseq_appl);
3585 	}
3586 	if (rsm == rack->r_ctl.rc_resend)
3587 		rack->r_ctl.rc_resend = NULL;
3588 	if (rsm == rack->r_ctl.rc_end_appl)
3589 		rack->r_ctl.rc_end_appl = NULL;
3590 	if (rack->r_ctl.rc_tlpsend == rsm)
3591 		rack->r_ctl.rc_tlpsend = NULL;
3592 	if (rack->r_ctl.rc_sacklast == rsm)
3593 		rack->r_ctl.rc_sacklast = NULL;
3594 	memset(rsm, 0, sizeof(struct rack_sendmap));
3595 	/* Make sure we are not going to overrun our count limit of 0xff */
3596 	if ((rack->rc_free_cnt + 1) > RACK_FREE_CNT_MAX) {
3597 		rack_free_trim(rack);
3598 	}
3599 	TAILQ_INSERT_HEAD(&rack->r_ctl.rc_free, rsm, r_tnext);
3600 	rack->rc_free_cnt++;
3601 }
3602 
3603 static uint32_t
rack_get_measure_window(struct tcpcb * tp,struct tcp_rack * rack)3604 rack_get_measure_window(struct tcpcb *tp, struct tcp_rack *rack)
3605 {
3606 	uint64_t srtt, bw, len, tim;
3607 	uint32_t segsiz, def_len, minl;
3608 
3609 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
3610 	def_len = rack_def_data_window * segsiz;
3611 	if (rack->rc_gp_filled == 0) {
3612 		/*
3613 		 * We have no measurement (IW is in flight?) so
3614 		 * we can only guess using our data_window sysctl
3615 		 * value (usually 20MSS).
3616 		 */
3617 		return (def_len);
3618 	}
3619 	/*
3620 	 * Now we have a number of factors to consider.
3621 	 *
3622 	 * 1) We have a desired BDP which is usually
3623 	 *    at least 2.
3624 	 * 2) We have a minimum number of rtt's usually 1 SRTT
3625 	 *    but we allow it too to be more.
3626 	 * 3) We want to make sure a measurement last N useconds (if
3627 	 *    we have set rack_min_measure_usec.
3628 	 *
3629 	 * We handle the first concern here by trying to create a data
3630 	 * window of max(rack_def_data_window, DesiredBDP). The
3631 	 * second concern we handle in not letting the measurement
3632 	 * window end normally until at least the required SRTT's
3633 	 * have gone by which is done further below in
3634 	 * rack_enough_for_measurement(). Finally the third concern
3635 	 * we also handle here by calculating how long that time
3636 	 * would take at the current BW and then return the
3637 	 * max of our first calculation and that length. Note
3638 	 * that if rack_min_measure_usec is 0, we don't deal
3639 	 * with concern 3. Also for both Concern 1 and 3 an
3640 	 * application limited period could end the measurement
3641 	 * earlier.
3642 	 *
3643 	 * So lets calculate the BDP with the "known" b/w using
3644 	 * the SRTT has our rtt and then multiply it by the
3645 	 * goal.
3646 	 */
3647 	bw = rack_get_bw(rack);
3648 	srtt = (uint64_t)tp->t_srtt;
3649 	len = bw * srtt;
3650 	len /= (uint64_t)HPTS_USEC_IN_SEC;
3651 	len *= max(1, rack_goal_bdp);
3652 	/* Now we need to round up to the nearest MSS */
3653 	len = roundup(len, segsiz);
3654 	if (rack_min_measure_usec) {
3655 		/* Now calculate our min length for this b/w */
3656 		tim = rack_min_measure_usec;
3657 		minl = (tim * bw) / (uint64_t)HPTS_USEC_IN_SEC;
3658 		if (minl == 0)
3659 			minl = 1;
3660 		minl = roundup(minl, segsiz);
3661 		if (len < minl)
3662 			len = minl;
3663 	}
3664 	/*
3665 	 * Now if we have a very small window we want
3666 	 * to attempt to get the window that is
3667 	 * as small as possible. This happens on
3668 	 * low b/w connections and we don't want to
3669 	 * span huge numbers of rtt's between measurements.
3670 	 *
3671 	 * We basically include 2 over our "MIN window" so
3672 	 * that the measurement can be shortened (possibly) by
3673 	 * an ack'ed packet.
3674 	 */
3675 	if (len < def_len)
3676 		return (max((uint32_t)len, ((MIN_GP_WIN+2) * segsiz)));
3677 	else
3678 		return (max((uint32_t)len, def_len));
3679 
3680 }
3681 
3682 static int
rack_enough_for_measurement(struct tcpcb * tp,struct tcp_rack * rack,tcp_seq th_ack,uint8_t * quality)3683 rack_enough_for_measurement(struct tcpcb *tp, struct tcp_rack *rack, tcp_seq th_ack, uint8_t *quality)
3684 {
3685 	uint32_t tim, srtts, segsiz;
3686 
3687 	/*
3688 	 * Has enough time passed for the GP measurement to be valid?
3689 	 */
3690 	if (SEQ_LT(th_ack, tp->gput_seq)) {
3691 		/* Not enough bytes yet */
3692 		return (0);
3693 	}
3694 	if ((tp->snd_max == tp->snd_una) ||
3695 	    (th_ack == tp->snd_max)){
3696 		/*
3697 		 * All is acked quality of all acked is
3698 		 * usually low or medium, but we in theory could split
3699 		 * all acked into two cases, where you got
3700 		 * a signifigant amount of your window and
3701 		 * where you did not. For now we leave it
3702 		 * but it is something to contemplate in the
3703 		 * future. The danger here is that delayed ack
3704 		 * is effecting the last byte (which is a 50:50 chance).
3705 		 */
3706 		*quality = RACK_QUALITY_ALLACKED;
3707 		return (1);
3708 	}
3709 	if (SEQ_GEQ(th_ack,  tp->gput_ack)) {
3710 		/*
3711 		 * We obtained our entire window of data we wanted
3712 		 * no matter if we are in recovery or not then
3713 		 * its ok since expanding the window does not
3714 		 * make things fuzzy (or at least not as much).
3715 		 */
3716 		*quality = RACK_QUALITY_HIGH;
3717 		return (1);
3718 	}
3719 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
3720 	if (SEQ_LT(th_ack, tp->gput_ack) &&
3721 	    ((th_ack - tp->gput_seq) < max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
3722 		/* Not enough bytes yet */
3723 		return (0);
3724 	}
3725 	if (rack->r_ctl.rc_first_appl &&
3726 	    (SEQ_GEQ(th_ack, rack->r_ctl.rc_first_appl->r_end))) {
3727 		/*
3728 		 * We are up to the app limited send point
3729 		 * we have to measure irrespective of the time..
3730 		 */
3731 		*quality = RACK_QUALITY_APPLIMITED;
3732 		return (1);
3733 	}
3734 	/* Now what about time? */
3735 	srtts = (rack->r_ctl.rc_gp_srtt * rack_min_srtts);
3736 	tim = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - tp->gput_ts;
3737 	if ((tim >= srtts) && (IN_RECOVERY(rack->rc_tp->t_flags) == 0)) {
3738 		/*
3739 		 * We do not allow a measurement if we are in recovery
3740 		 * that would shrink the goodput window we wanted.
3741 		 * This is to prevent cloudyness of when the last send
3742 		 * was actually made.
3743 		 */
3744 		*quality = RACK_QUALITY_HIGH;
3745 		return (1);
3746 	}
3747 	/* Nope not even a full SRTT has passed */
3748 	return (0);
3749 }
3750 
3751 static void
rack_log_timely(struct tcp_rack * rack,uint32_t logged,uint64_t cur_bw,uint64_t low_bnd,uint64_t up_bnd,int line,uint8_t method)3752 rack_log_timely(struct tcp_rack *rack,
3753 		uint32_t logged, uint64_t cur_bw, uint64_t low_bnd,
3754 		uint64_t up_bnd, int line, uint8_t method)
3755 {
3756 	if (tcp_bblogging_on(rack->rc_tp)) {
3757 		union tcp_log_stackspecific log;
3758 		struct timeval tv;
3759 
3760 		memset(&log, 0, sizeof(log));
3761 		log.u_bbr.flex1 = logged;
3762 		log.u_bbr.flex2 = rack->rc_gp_timely_inc_cnt;
3763 		log.u_bbr.flex2 <<= 4;
3764 		log.u_bbr.flex2 |= rack->rc_gp_timely_dec_cnt;
3765 		log.u_bbr.flex2 <<= 4;
3766 		log.u_bbr.flex2 |= rack->rc_gp_incr;
3767 		log.u_bbr.flex2 <<= 4;
3768 		log.u_bbr.flex2 |= rack->rc_gp_bwred;
3769 		log.u_bbr.flex3 = rack->rc_gp_incr;
3770 		log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
3771 		log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ca;
3772 		log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_rec;
3773 		log.u_bbr.flex7 = rack->rc_gp_bwred;
3774 		log.u_bbr.flex8 = method;
3775 		log.u_bbr.cur_del_rate = cur_bw;
3776 		log.u_bbr.delRate = low_bnd;
3777 		log.u_bbr.bw_inuse = up_bnd;
3778 		log.u_bbr.rttProp = rack_get_bw(rack);
3779 		log.u_bbr.pkt_epoch = line;
3780 		log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
3781 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3782 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3783 		log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
3784 		log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
3785 		log.u_bbr.cwnd_gain = rack->rc_dragged_bottom;
3786 		log.u_bbr.cwnd_gain <<= 1;
3787 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_rec;
3788 		log.u_bbr.cwnd_gain <<= 1;
3789 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
3790 		log.u_bbr.cwnd_gain <<= 1;
3791 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
3792 		log.u_bbr.lost = rack->r_ctl.rc_loss_count;
3793 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3794 		    &rack->rc_inp->inp_socket->so_rcv,
3795 		    &rack->rc_inp->inp_socket->so_snd,
3796 		    TCP_TIMELY_WORK, 0,
3797 		    0, &log, false, &tv);
3798 	}
3799 }
3800 
3801 static int
rack_bw_can_be_raised(struct tcp_rack * rack,uint64_t cur_bw,uint64_t last_bw_est,uint16_t mult)3802 rack_bw_can_be_raised(struct tcp_rack *rack, uint64_t cur_bw, uint64_t last_bw_est, uint16_t mult)
3803 {
3804 	/*
3805 	 * Before we increase we need to know if
3806 	 * the estimate just made was less than
3807 	 * our pacing goal (i.e. (cur_bw * mult) > last_bw_est)
3808 	 *
3809 	 * If we already are pacing at a fast enough
3810 	 * rate to push us faster there is no sense of
3811 	 * increasing.
3812 	 *
3813 	 * We first caculate our actual pacing rate (ss or ca multiplier
3814 	 * times our cur_bw).
3815 	 *
3816 	 * Then we take the last measured rate and multipy by our
3817 	 * maximum pacing overage to give us a max allowable rate.
3818 	 *
3819 	 * If our act_rate is smaller than our max_allowable rate
3820 	 * then we should increase. Else we should hold steady.
3821 	 *
3822 	 */
3823 	uint64_t act_rate, max_allow_rate;
3824 
3825 	if (rack_timely_no_stopping)
3826 		return (1);
3827 
3828 	if ((cur_bw == 0) || (last_bw_est == 0)) {
3829 		/*
3830 		 * Initial startup case or
3831 		 * everything is acked case.
3832 		 */
3833 		rack_log_timely(rack,  mult, cur_bw, 0, 0,
3834 				__LINE__, 9);
3835 		return (1);
3836 	}
3837 	if (mult <= 100) {
3838 		/*
3839 		 * We can always pace at or slightly above our rate.
3840 		 */
3841 		rack_log_timely(rack,  mult, cur_bw, 0, 0,
3842 				__LINE__, 9);
3843 		return (1);
3844 	}
3845 	act_rate = cur_bw * (uint64_t)mult;
3846 	act_rate /= 100;
3847 	max_allow_rate = last_bw_est * ((uint64_t)rack_max_per_above + (uint64_t)100);
3848 	max_allow_rate /= 100;
3849 	if (act_rate < max_allow_rate) {
3850 		/*
3851 		 * Here the rate we are actually pacing at
3852 		 * is smaller than 10% above our last measurement.
3853 		 * This means we are pacing below what we would
3854 		 * like to try to achieve (plus some wiggle room).
3855 		 */
3856 		rack_log_timely(rack,  mult, cur_bw, act_rate, max_allow_rate,
3857 				__LINE__, 9);
3858 		return (1);
3859 	} else {
3860 		/*
3861 		 * Here we are already pacing at least rack_max_per_above(10%)
3862 		 * what we are getting back. This indicates most likely
3863 		 * that we are being limited (cwnd/rwnd/app) and can't
3864 		 * get any more b/w. There is no sense of trying to
3865 		 * raise up the pacing rate its not speeding us up
3866 		 * and we already are pacing faster than we are getting.
3867 		 */
3868 		rack_log_timely(rack,  mult, cur_bw, act_rate, max_allow_rate,
3869 				__LINE__, 8);
3870 		return (0);
3871 	}
3872 }
3873 
3874 static void
rack_validate_multipliers_at_or_above100(struct tcp_rack * rack)3875 rack_validate_multipliers_at_or_above100(struct tcp_rack *rack)
3876 {
3877 	/*
3878 	 * When we drag bottom, we want to assure
3879 	 * that no multiplier is below 1.0, if so
3880 	 * we want to restore it to at least that.
3881 	 */
3882 	if (rack->r_ctl.rack_per_of_gp_rec  < 100) {
3883 		/* This is unlikely we usually do not touch recovery */
3884 		rack->r_ctl.rack_per_of_gp_rec = 100;
3885 	}
3886 	if (rack->r_ctl.rack_per_of_gp_ca < 100) {
3887 		rack->r_ctl.rack_per_of_gp_ca = 100;
3888 	}
3889 	if (rack->r_ctl.rack_per_of_gp_ss < 100) {
3890 		rack->r_ctl.rack_per_of_gp_ss = 100;
3891 	}
3892 }
3893 
3894 static void
rack_validate_multipliers_at_or_below_100(struct tcp_rack * rack)3895 rack_validate_multipliers_at_or_below_100(struct tcp_rack *rack)
3896 {
3897 	if (rack->r_ctl.rack_per_of_gp_ca > 100) {
3898 		rack->r_ctl.rack_per_of_gp_ca = 100;
3899 	}
3900 	if (rack->r_ctl.rack_per_of_gp_ss > 100) {
3901 		rack->r_ctl.rack_per_of_gp_ss = 100;
3902 	}
3903 }
3904 
3905 static void
rack_increase_bw_mul(struct tcp_rack * rack,int timely_says,uint64_t cur_bw,uint64_t last_bw_est,int override)3906 rack_increase_bw_mul(struct tcp_rack *rack, int timely_says, uint64_t cur_bw, uint64_t last_bw_est, int override)
3907 {
3908 	int32_t  calc, logged, plus;
3909 
3910 	logged = 0;
3911 
3912 	if (rack->rc_skip_timely)
3913 		return;
3914 	if (override) {
3915 		/*
3916 		 * override is passed when we are
3917 		 * loosing b/w and making one last
3918 		 * gasp at trying to not loose out
3919 		 * to a new-reno flow.
3920 		 */
3921 		goto extra_boost;
3922 	}
3923 	/* In classic timely we boost by 5x if we have 5 increases in a row, lets not */
3924 	if (rack->rc_gp_incr &&
3925 	    ((rack->rc_gp_timely_inc_cnt + 1) >= RACK_TIMELY_CNT_BOOST)) {
3926 		/*
3927 		 * Reset and get 5 strokes more before the boost. Note
3928 		 * that the count is 0 based so we have to add one.
3929 		 */
3930 extra_boost:
3931 		plus = (uint32_t)rack_gp_increase_per * RACK_TIMELY_CNT_BOOST;
3932 		rack->rc_gp_timely_inc_cnt = 0;
3933 	} else
3934 		plus = (uint32_t)rack_gp_increase_per;
3935 	/* Must be at least 1% increase for true timely increases */
3936 	if ((plus < 1) &&
3937 	    ((rack->r_ctl.rc_rtt_diff <= 0) || (timely_says <= 0)))
3938 		plus = 1;
3939 	if (rack->rc_gp_saw_rec &&
3940 	    (rack->rc_gp_no_rec_chg == 0) &&
3941 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3942 				  rack->r_ctl.rack_per_of_gp_rec)) {
3943 		/* We have been in recovery ding it too */
3944 		calc = rack->r_ctl.rack_per_of_gp_rec + plus;
3945 		if (calc > 0xffff)
3946 			calc = 0xffff;
3947 		logged |= 1;
3948 		rack->r_ctl.rack_per_of_gp_rec = (uint16_t)calc;
3949 		if (rack->r_ctl.rack_per_upper_bound_ca &&
3950 		    (rack->rc_dragged_bottom == 0) &&
3951 		    (rack->r_ctl.rack_per_of_gp_rec > rack->r_ctl.rack_per_upper_bound_ca))
3952 			rack->r_ctl.rack_per_of_gp_rec = rack->r_ctl.rack_per_upper_bound_ca;
3953 	}
3954 	if (rack->rc_gp_saw_ca &&
3955 	    (rack->rc_gp_saw_ss == 0) &&
3956 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3957 				  rack->r_ctl.rack_per_of_gp_ca)) {
3958 		/* In CA */
3959 		calc = rack->r_ctl.rack_per_of_gp_ca + plus;
3960 		if (calc > 0xffff)
3961 			calc = 0xffff;
3962 		logged |= 2;
3963 		rack->r_ctl.rack_per_of_gp_ca = (uint16_t)calc;
3964 		if (rack->r_ctl.rack_per_upper_bound_ca &&
3965 		    (rack->rc_dragged_bottom == 0) &&
3966 		    (rack->r_ctl.rack_per_of_gp_ca > rack->r_ctl.rack_per_upper_bound_ca))
3967 			rack->r_ctl.rack_per_of_gp_ca = rack->r_ctl.rack_per_upper_bound_ca;
3968 	}
3969 	if (rack->rc_gp_saw_ss &&
3970 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3971 				  rack->r_ctl.rack_per_of_gp_ss)) {
3972 		/* In SS */
3973 		calc = rack->r_ctl.rack_per_of_gp_ss + plus;
3974 		if (calc > 0xffff)
3975 			calc = 0xffff;
3976 		rack->r_ctl.rack_per_of_gp_ss = (uint16_t)calc;
3977 		if (rack->r_ctl.rack_per_upper_bound_ss &&
3978 		    (rack->rc_dragged_bottom == 0) &&
3979 		    (rack->r_ctl.rack_per_of_gp_ss > rack->r_ctl.rack_per_upper_bound_ss))
3980 			rack->r_ctl.rack_per_of_gp_ss = rack->r_ctl.rack_per_upper_bound_ss;
3981 		logged |= 4;
3982 	}
3983 	if (logged &&
3984 	    (rack->rc_gp_incr == 0)){
3985 		/* Go into increment mode */
3986 		rack->rc_gp_incr = 1;
3987 		rack->rc_gp_timely_inc_cnt = 0;
3988 	}
3989 	if (rack->rc_gp_incr &&
3990 	    logged &&
3991 	    (rack->rc_gp_timely_inc_cnt < RACK_TIMELY_CNT_BOOST)) {
3992 		rack->rc_gp_timely_inc_cnt++;
3993 	}
3994 	rack_log_timely(rack,  logged, plus, 0, 0,
3995 			__LINE__, 1);
3996 }
3997 
3998 static uint32_t
rack_get_decrease(struct tcp_rack * rack,uint32_t curper,int32_t rtt_diff)3999 rack_get_decrease(struct tcp_rack *rack, uint32_t curper, int32_t rtt_diff)
4000 {
4001 	/*-
4002 	 * norm_grad = rtt_diff / minrtt;
4003 	 * new_per = curper * (1 - B * norm_grad)
4004 	 *
4005 	 * B = rack_gp_decrease_per (default 80%)
4006 	 * rtt_dif = input var current rtt-diff
4007 	 * curper = input var current percentage
4008 	 * minrtt = from rack filter
4009 	 *
4010 	 * In order to do the floating point calculations above we
4011 	 * do an integer conversion. The code looks confusing so let me
4012 	 * translate it into something that use more variables and
4013 	 * is clearer for us humans :)
4014 	 *
4015 	 * uint64_t norm_grad, inverse, reduce_by, final_result;
4016 	 * uint32_t perf;
4017 	 *
4018 	 * norm_grad = (((uint64_t)rtt_diff * 1000000) /
4019 	 *             (uint64_t)get_filter_small(&rack->r_ctl.rc_gp_min_rtt));
4020 	 * inverse = ((uint64_t)rack_gp_decrease * (uint64_t)1000000) * norm_grad;
4021 	 * inverse /= 1000000;
4022 	 * reduce_by = (1000000 - inverse);
4023 	 * final_result = (cur_per * reduce_by) / 1000000;
4024 	 * perf = (uint32_t)final_result;
4025 	 */
4026 	uint64_t perf;
4027 
4028 	perf = (((uint64_t)curper * ((uint64_t)1000000 -
4029 		    ((uint64_t)rack_gp_decrease_per * (uint64_t)10000 *
4030 		     (((uint64_t)rtt_diff * (uint64_t)1000000)/
4031 		      (uint64_t)get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt)))/
4032 		     (uint64_t)1000000)) /
4033 		(uint64_t)1000000);
4034 	if (perf > curper) {
4035 		/* TSNH */
4036 		perf = curper - 1;
4037 	}
4038 	return ((uint32_t)perf);
4039 }
4040 
4041 static uint32_t
rack_decrease_highrtt(struct tcp_rack * rack,uint32_t curper,uint32_t rtt)4042 rack_decrease_highrtt(struct tcp_rack *rack, uint32_t curper, uint32_t rtt)
4043 {
4044 	/*
4045 	 *                                   highrttthresh
4046 	 * result = curper * (1 - (B * ( 1 -  ------          ))
4047 	 *                                     gp_srtt
4048 	 *
4049 	 * B = rack_gp_decrease_per (default .8 i.e. 80)
4050 	 * highrttthresh = filter_min * rack_gp_rtt_maxmul
4051 	 */
4052 	uint64_t perf;
4053 	uint32_t highrttthresh;
4054 
4055 	highrttthresh = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
4056 
4057 	perf = (((uint64_t)curper * ((uint64_t)1000000 -
4058 				     ((uint64_t)rack_gp_decrease_per * ((uint64_t)1000000 -
4059 					((uint64_t)highrttthresh * (uint64_t)1000000) /
4060 						    (uint64_t)rtt)) / 100)) /(uint64_t)1000000);
4061 	if (tcp_bblogging_on(rack->rc_tp)) {
4062 		uint64_t log1;
4063 
4064 		log1 = rtt;
4065 		log1 <<= 32;
4066 		log1 |= highrttthresh;
4067 		rack_log_timely(rack,
4068 				rack_gp_decrease_per,
4069 				(uint64_t)curper,
4070 				log1,
4071 				perf,
4072 				__LINE__,
4073 				15);
4074 	}
4075 	return (perf);
4076 }
4077 
4078 static void
rack_decrease_bw_mul(struct tcp_rack * rack,int timely_says,uint32_t rtt,int32_t rtt_diff)4079 rack_decrease_bw_mul(struct tcp_rack *rack, int timely_says, uint32_t rtt, int32_t rtt_diff)
4080 {
4081 	uint64_t logvar, logvar2, logvar3;
4082 	uint32_t logged, new_per, ss_red, ca_red, rec_red, alt, val;
4083 
4084 	if (rack->rc_skip_timely)
4085 		return;
4086 	if (rack->rc_gp_incr) {
4087 		/* Turn off increment counting */
4088 		rack->rc_gp_incr = 0;
4089 		rack->rc_gp_timely_inc_cnt = 0;
4090 	}
4091 	ss_red = ca_red = rec_red = 0;
4092 	logged = 0;
4093 	/* Calculate the reduction value */
4094 	if (rtt_diff < 0) {
4095 		rtt_diff *= -1;
4096 	}
4097 	/* Must be at least 1% reduction */
4098 	if (rack->rc_gp_saw_rec && (rack->rc_gp_no_rec_chg == 0)) {
4099 		/* We have been in recovery ding it too */
4100 		if (timely_says == 2) {
4101 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_rec, rtt);
4102 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
4103 			if (alt < new_per)
4104 				val = alt;
4105 			else
4106 				val = new_per;
4107 		} else
4108 			 val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
4109 		if (rack->r_ctl.rack_per_of_gp_rec > val) {
4110 			rec_red = (rack->r_ctl.rack_per_of_gp_rec - val);
4111 			rack->r_ctl.rack_per_of_gp_rec = (uint16_t)val;
4112 		} else {
4113 			rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
4114 			rec_red = 0;
4115 		}
4116 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_rec)
4117 			rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
4118 		logged |= 1;
4119 	}
4120 	if (rack->rc_gp_saw_ss) {
4121 		/* Sent in SS */
4122 		if (timely_says == 2) {
4123 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ss, rtt);
4124 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ss, rtt_diff);
4125 			if (alt < new_per)
4126 				val = alt;
4127 			else
4128 				val = new_per;
4129 		} else
4130 			val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ss, rtt_diff);
4131 		if (rack->r_ctl.rack_per_of_gp_ss > new_per) {
4132 			ss_red = rack->r_ctl.rack_per_of_gp_ss - val;
4133 			rack->r_ctl.rack_per_of_gp_ss = (uint16_t)val;
4134 		} else {
4135 			ss_red = new_per;
4136 			rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
4137 			logvar = new_per;
4138 			logvar <<= 32;
4139 			logvar |= alt;
4140 			logvar2 = (uint32_t)rtt;
4141 			logvar2 <<= 32;
4142 			logvar2 |= (uint32_t)rtt_diff;
4143 			logvar3 = rack_gp_rtt_maxmul;
4144 			logvar3 <<= 32;
4145 			logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
4146 			rack_log_timely(rack, timely_says,
4147 					logvar2, logvar3,
4148 					logvar, __LINE__, 10);
4149 		}
4150 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ss)
4151 			rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
4152 		logged |= 4;
4153 	} else if (rack->rc_gp_saw_ca) {
4154 		/* Sent in CA */
4155 		if (timely_says == 2) {
4156 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ca, rtt);
4157 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ca, rtt_diff);
4158 			if (alt < new_per)
4159 				val = alt;
4160 			else
4161 				val = new_per;
4162 		} else
4163 			val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ca, rtt_diff);
4164 		if (rack->r_ctl.rack_per_of_gp_ca > val) {
4165 			ca_red = rack->r_ctl.rack_per_of_gp_ca - val;
4166 			rack->r_ctl.rack_per_of_gp_ca = (uint16_t)val;
4167 		} else {
4168 			rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
4169 			ca_red = 0;
4170 			logvar = new_per;
4171 			logvar <<= 32;
4172 			logvar |= alt;
4173 			logvar2 = (uint32_t)rtt;
4174 			logvar2 <<= 32;
4175 			logvar2 |= (uint32_t)rtt_diff;
4176 			logvar3 = rack_gp_rtt_maxmul;
4177 			logvar3 <<= 32;
4178 			logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
4179 			rack_log_timely(rack, timely_says,
4180 					logvar2, logvar3,
4181 					logvar, __LINE__, 10);
4182 		}
4183 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ca)
4184 			rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
4185 		logged |= 2;
4186 	}
4187 	if (rack->rc_gp_timely_dec_cnt < 0x7) {
4188 		rack->rc_gp_timely_dec_cnt++;
4189 		if (rack_timely_dec_clear &&
4190 		    (rack->rc_gp_timely_dec_cnt == rack_timely_dec_clear))
4191 			rack->rc_gp_timely_dec_cnt = 0;
4192 	}
4193 	logvar = ss_red;
4194 	logvar <<= 32;
4195 	logvar |= ca_red;
4196 	rack_log_timely(rack,  logged, rec_red, rack_per_lower_bound, logvar,
4197 			__LINE__, 2);
4198 }
4199 
4200 static void
rack_log_rtt_shrinks(struct tcp_rack * rack,uint32_t us_cts,uint32_t rtt,uint32_t line,uint8_t reas)4201 rack_log_rtt_shrinks(struct tcp_rack *rack, uint32_t us_cts,
4202 		     uint32_t rtt, uint32_t line, uint8_t reas)
4203 {
4204 	if (tcp_bblogging_on(rack->rc_tp)) {
4205 		union tcp_log_stackspecific log;
4206 		struct timeval tv;
4207 
4208 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
4209 		log.u_bbr.flex1 = line;
4210 		log.u_bbr.flex2 = rack->r_ctl.rc_time_probertt_starts;
4211 		log.u_bbr.flex3 = rack->r_ctl.rc_lower_rtt_us_cts;
4212 		log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
4213 		log.u_bbr.flex5 = rtt;
4214 		log.u_bbr.flex6 = rack->rc_highly_buffered;
4215 		log.u_bbr.flex6 <<= 1;
4216 		log.u_bbr.flex6 |= rack->forced_ack;
4217 		log.u_bbr.flex6 <<= 1;
4218 		log.u_bbr.flex6 |= rack->rc_gp_dyn_mul;
4219 		log.u_bbr.flex6 <<= 1;
4220 		log.u_bbr.flex6 |= rack->in_probe_rtt;
4221 		log.u_bbr.flex6 <<= 1;
4222 		log.u_bbr.flex6 |= rack->measure_saw_probe_rtt;
4223 		log.u_bbr.flex7 = rack->r_ctl.rack_per_of_gp_probertt;
4224 		log.u_bbr.pacing_gain = rack->r_ctl.rack_per_of_gp_ca;
4225 		log.u_bbr.cwnd_gain = rack->r_ctl.rack_per_of_gp_rec;
4226 		log.u_bbr.flex8 = reas;
4227 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
4228 		log.u_bbr.delRate = rack_get_bw(rack);
4229 		log.u_bbr.cur_del_rate = rack->r_ctl.rc_highest_us_rtt;
4230 		log.u_bbr.cur_del_rate <<= 32;
4231 		log.u_bbr.cur_del_rate |= rack->r_ctl.rc_lowest_us_rtt;
4232 		log.u_bbr.applimited = rack->r_ctl.rc_time_probertt_entered;
4233 		log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
4234 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
4235 		log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
4236 		log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
4237 		log.u_bbr.pkt_epoch = rack->r_ctl.rc_lower_rtt_us_cts;
4238 		log.u_bbr.delivered = rack->r_ctl.rc_target_probertt_flight;
4239 		log.u_bbr.lost = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
4240 		log.u_bbr.rttProp = us_cts;
4241 		log.u_bbr.rttProp <<= 32;
4242 		log.u_bbr.rttProp |= rack->r_ctl.rc_entry_gp_rtt;
4243 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
4244 		    &rack->rc_inp->inp_socket->so_rcv,
4245 		    &rack->rc_inp->inp_socket->so_snd,
4246 		    BBR_LOG_RTT_SHRINKS, 0,
4247 		    0, &log, false, &rack->r_ctl.act_rcv_time);
4248 	}
4249 }
4250 
4251 static void
rack_set_prtt_target(struct tcp_rack * rack,uint32_t segsiz,uint32_t rtt)4252 rack_set_prtt_target(struct tcp_rack *rack, uint32_t segsiz, uint32_t rtt)
4253 {
4254 	uint64_t bwdp;
4255 
4256 	bwdp = rack_get_bw(rack);
4257 	bwdp *= (uint64_t)rtt;
4258 	bwdp /= (uint64_t)HPTS_USEC_IN_SEC;
4259 	rack->r_ctl.rc_target_probertt_flight = roundup((uint32_t)bwdp, segsiz);
4260 	if (rack->r_ctl.rc_target_probertt_flight < (segsiz * rack_timely_min_segs)) {
4261 		/*
4262 		 * A window protocol must be able to have 4 packets
4263 		 * outstanding as the floor in order to function
4264 		 * (especially considering delayed ack :D).
4265 		 */
4266 		rack->r_ctl.rc_target_probertt_flight = (segsiz * rack_timely_min_segs);
4267 	}
4268 }
4269 
4270 static void
rack_enter_probertt(struct tcp_rack * rack,uint32_t us_cts)4271 rack_enter_probertt(struct tcp_rack *rack, uint32_t us_cts)
4272 {
4273 	/**
4274 	 * ProbeRTT is a bit different in rack_pacing than in
4275 	 * BBR. It is like BBR in that it uses the lowering of
4276 	 * the RTT as a signal that we saw something new and
4277 	 * counts from there for how long between. But it is
4278 	 * different in that its quite simple. It does not
4279 	 * play with the cwnd and wait until we get down
4280 	 * to N segments outstanding and hold that for
4281 	 * 200ms. Instead it just sets the pacing reduction
4282 	 * rate to a set percentage (70 by default) and hold
4283 	 * that for a number of recent GP Srtt's.
4284 	 */
4285 	uint32_t segsiz;
4286 
4287 	rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
4288 	if (rack->rc_gp_dyn_mul == 0)
4289 		return;
4290 
4291 	if (rack->rc_tp->snd_max == rack->rc_tp->snd_una) {
4292 		/* We are idle */
4293 		return;
4294 	}
4295 	if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
4296 	    SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
4297 		/*
4298 		 * Stop the goodput now, the idea here is
4299 		 * that future measurements with in_probe_rtt
4300 		 * won't register if they are not greater so
4301 		 * we want to get what info (if any) is available
4302 		 * now.
4303 		 */
4304 		rack_do_goodput_measurement(rack->rc_tp, rack,
4305 					    rack->rc_tp->snd_una, __LINE__,
4306 					    RACK_QUALITY_PROBERTT);
4307 	}
4308 	rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
4309 	rack->r_ctl.rc_time_probertt_entered = us_cts;
4310 	segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
4311 		     rack->r_ctl.rc_pace_min_segs);
4312 	rack->in_probe_rtt = 1;
4313 	rack->measure_saw_probe_rtt = 1;
4314 	rack->r_ctl.rc_time_probertt_starts = 0;
4315 	rack->r_ctl.rc_entry_gp_rtt = rack->r_ctl.rc_gp_srtt;
4316 	if (rack_probertt_use_min_rtt_entry)
4317 		rack_set_prtt_target(rack, segsiz, get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
4318 	else
4319 		rack_set_prtt_target(rack, segsiz, rack->r_ctl.rc_gp_srtt);
4320 	rack_log_rtt_shrinks(rack,  us_cts,  get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4321 			     __LINE__, RACK_RTTS_ENTERPROBE);
4322 }
4323 
4324 static void
rack_exit_probertt(struct tcp_rack * rack,uint32_t us_cts)4325 rack_exit_probertt(struct tcp_rack *rack, uint32_t us_cts)
4326 {
4327 	struct rack_sendmap *rsm;
4328 	uint32_t segsiz;
4329 
4330 	segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
4331 		     rack->r_ctl.rc_pace_min_segs);
4332 	rack->in_probe_rtt = 0;
4333 	if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
4334 	    SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
4335 		/*
4336 		 * Stop the goodput now, the idea here is
4337 		 * that future measurements with in_probe_rtt
4338 		 * won't register if they are not greater so
4339 		 * we want to get what info (if any) is available
4340 		 * now.
4341 		 */
4342 		rack_do_goodput_measurement(rack->rc_tp, rack,
4343 					    rack->rc_tp->snd_una, __LINE__,
4344 					    RACK_QUALITY_PROBERTT);
4345 	} else if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
4346 		/*
4347 		 * We don't have enough data to make a measurement.
4348 		 * So lets just stop and start here after exiting
4349 		 * probe-rtt. We probably are not interested in
4350 		 * the results anyway.
4351 		 */
4352 		rack->rc_tp->t_flags &= ~TF_GPUTINPROG;
4353 	}
4354 	/*
4355 	 * Measurements through the current snd_max are going
4356 	 * to be limited by the slower pacing rate.
4357 	 *
4358 	 * We need to mark these as app-limited so we
4359 	 * don't collapse the b/w.
4360 	 */
4361 	rsm = tqhash_max(rack->r_ctl.tqh);
4362 	if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
4363 		if (rack->r_ctl.rc_app_limited_cnt == 0)
4364 			rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
4365 		else {
4366 			/*
4367 			 * Go out to the end app limited and mark
4368 			 * this new one as next and move the end_appl up
4369 			 * to this guy.
4370 			 */
4371 			if (rack->r_ctl.rc_end_appl)
4372 				rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
4373 			rack->r_ctl.rc_end_appl = rsm;
4374 		}
4375 		rsm->r_flags |= RACK_APP_LIMITED;
4376 		rack->r_ctl.rc_app_limited_cnt++;
4377 	}
4378 	/*
4379 	 * Now, we need to examine our pacing rate multipliers.
4380 	 * If its under 100%, we need to kick it back up to
4381 	 * 100%. We also don't let it be over our "max" above
4382 	 * the actual rate i.e. 100% + rack_clamp_atexit_prtt.
4383 	 * Note setting clamp_atexit_prtt to 0 has the effect
4384 	 * of setting CA/SS to 100% always at exit (which is
4385 	 * the default behavior).
4386 	 */
4387 	if (rack_probertt_clear_is) {
4388 		rack->rc_gp_incr = 0;
4389 		rack->rc_gp_bwred = 0;
4390 		rack->rc_gp_timely_inc_cnt = 0;
4391 		rack->rc_gp_timely_dec_cnt = 0;
4392 	}
4393 	/* Do we do any clamping at exit? */
4394 	if (rack->rc_highly_buffered && rack_atexit_prtt_hbp) {
4395 		rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt_hbp;
4396 		rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt_hbp;
4397 	}
4398 	if ((rack->rc_highly_buffered == 0) && rack_atexit_prtt) {
4399 		rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt;
4400 		rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt;
4401 	}
4402 	/*
4403 	 * Lets set rtt_diff to 0, so that we will get a "boost"
4404 	 * after exiting.
4405 	 */
4406 	rack->r_ctl.rc_rtt_diff = 0;
4407 
4408 	/* Clear all flags so we start fresh */
4409 	rack->rc_tp->t_bytes_acked = 0;
4410 	rack->rc_tp->t_ccv.flags &= ~CCF_ABC_SENTAWND;
4411 	/*
4412 	 * If configured to, set the cwnd and ssthresh to
4413 	 * our targets.
4414 	 */
4415 	if (rack_probe_rtt_sets_cwnd) {
4416 		uint64_t ebdp;
4417 		uint32_t setto;
4418 
4419 		/* Set ssthresh so we get into CA once we hit our target */
4420 		if (rack_probertt_use_min_rtt_exit == 1) {
4421 			/* Set to min rtt */
4422 			rack_set_prtt_target(rack, segsiz,
4423 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
4424 		} else if (rack_probertt_use_min_rtt_exit == 2) {
4425 			/* Set to current gp rtt */
4426 			rack_set_prtt_target(rack, segsiz,
4427 					     rack->r_ctl.rc_gp_srtt);
4428 		} else if (rack_probertt_use_min_rtt_exit == 3) {
4429 			/* Set to entry gp rtt */
4430 			rack_set_prtt_target(rack, segsiz,
4431 					     rack->r_ctl.rc_entry_gp_rtt);
4432 		} else {
4433 			uint64_t sum;
4434 			uint32_t setval;
4435 
4436 			sum = rack->r_ctl.rc_entry_gp_rtt;
4437 			sum *= 10;
4438 			sum /= (uint64_t)(max(1, rack->r_ctl.rc_gp_srtt));
4439 			if (sum >= 20) {
4440 				/*
4441 				 * A highly buffered path needs
4442 				 * cwnd space for timely to work.
4443 				 * Lets set things up as if
4444 				 * we are heading back here again.
4445 				 */
4446 				setval = rack->r_ctl.rc_entry_gp_rtt;
4447 			} else if (sum >= 15) {
4448 				/*
4449 				 * Lets take the smaller of the
4450 				 * two since we are just somewhat
4451 				 * buffered.
4452 				 */
4453 				setval = rack->r_ctl.rc_gp_srtt;
4454 				if (setval > rack->r_ctl.rc_entry_gp_rtt)
4455 					setval = rack->r_ctl.rc_entry_gp_rtt;
4456 			} else {
4457 				/*
4458 				 * Here we are not highly buffered
4459 				 * and should pick the min we can to
4460 				 * keep from causing loss.
4461 				 */
4462 				setval = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
4463 			}
4464 			rack_set_prtt_target(rack, segsiz,
4465 					     setval);
4466 		}
4467 		if (rack_probe_rtt_sets_cwnd > 1) {
4468 			/* There is a percentage here to boost */
4469 			ebdp = rack->r_ctl.rc_target_probertt_flight;
4470 			ebdp *= rack_probe_rtt_sets_cwnd;
4471 			ebdp /= 100;
4472 			setto = rack->r_ctl.rc_target_probertt_flight + ebdp;
4473 		} else
4474 			setto = rack->r_ctl.rc_target_probertt_flight;
4475 		rack->rc_tp->snd_cwnd = roundup(setto, segsiz);
4476 		if (rack->rc_tp->snd_cwnd < (segsiz * rack_timely_min_segs)) {
4477 			/* Enforce a min */
4478 			rack->rc_tp->snd_cwnd = segsiz * rack_timely_min_segs;
4479 		}
4480 		/* If we set in the cwnd also set the ssthresh point so we are in CA */
4481 		rack->rc_tp->snd_ssthresh = (rack->rc_tp->snd_cwnd - 1);
4482 	}
4483 	rack_log_rtt_shrinks(rack,  us_cts,
4484 			     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4485 			     __LINE__, RACK_RTTS_EXITPROBE);
4486 	/* Clear times last so log has all the info */
4487 	rack->r_ctl.rc_probertt_sndmax_atexit = rack->rc_tp->snd_max;
4488 	rack->r_ctl.rc_time_probertt_entered = us_cts;
4489 	rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
4490 	rack->r_ctl.rc_time_of_last_probertt = us_cts;
4491 }
4492 
4493 static void
rack_check_probe_rtt(struct tcp_rack * rack,uint32_t us_cts)4494 rack_check_probe_rtt(struct tcp_rack *rack, uint32_t us_cts)
4495 {
4496 	/* Check in on probe-rtt */
4497 
4498 	if (rack->rc_gp_filled == 0) {
4499 		/* We do not do p-rtt unless we have gp measurements */
4500 		return;
4501 	}
4502 	if (rack->in_probe_rtt) {
4503 		uint64_t no_overflow;
4504 		uint32_t endtime, must_stay;
4505 
4506 		if (rack->r_ctl.rc_went_idle_time &&
4507 		    ((us_cts - rack->r_ctl.rc_went_idle_time) > rack_min_probertt_hold)) {
4508 			/*
4509 			 * We went idle during prtt, just exit now.
4510 			 */
4511 			rack_exit_probertt(rack, us_cts);
4512 		} else if (rack_probe_rtt_safety_val &&
4513 		    TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered) &&
4514 		    ((us_cts - rack->r_ctl.rc_time_probertt_entered) > rack_probe_rtt_safety_val)) {
4515 			/*
4516 			 * Probe RTT safety value triggered!
4517 			 */
4518 			rack_log_rtt_shrinks(rack,  us_cts,
4519 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4520 					     __LINE__, RACK_RTTS_SAFETY);
4521 			rack_exit_probertt(rack, us_cts);
4522 		}
4523 		/* Calculate the max we will wait */
4524 		endtime = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_max_drain_wait);
4525 		if (rack->rc_highly_buffered)
4526 			endtime += (rack->r_ctl.rc_gp_srtt * rack_max_drain_hbp);
4527 		/* Calculate the min we must wait */
4528 		must_stay = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_must_drain);
4529 		if ((ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.rc_target_probertt_flight) &&
4530 		    TSTMP_LT(us_cts, endtime)) {
4531 			uint32_t calc;
4532 			/* Do we lower more? */
4533 no_exit:
4534 			if (TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered))
4535 				calc = us_cts - rack->r_ctl.rc_time_probertt_entered;
4536 			else
4537 				calc = 0;
4538 			calc /= max(rack->r_ctl.rc_gp_srtt, 1);
4539 			if (calc) {
4540 				/* Maybe */
4541 				calc *= rack_per_of_gp_probertt_reduce;
4542 				if (calc > rack_per_of_gp_probertt)
4543 					rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_lowthresh;
4544 				else
4545 					rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt - calc;
4546 				/* Limit it too */
4547 				if (rack->r_ctl.rack_per_of_gp_probertt < rack_per_of_gp_lowthresh)
4548 					rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_lowthresh;
4549 			}
4550 			/* We must reach target or the time set */
4551 			return;
4552 		}
4553 		if (rack->r_ctl.rc_time_probertt_starts == 0) {
4554 			if ((TSTMP_LT(us_cts, must_stay) &&
4555 			     rack->rc_highly_buffered) ||
4556 			     (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) >
4557 			      rack->r_ctl.rc_target_probertt_flight)) {
4558 				/* We are not past the must_stay time */
4559 				goto no_exit;
4560 			}
4561 			rack_log_rtt_shrinks(rack,  us_cts,
4562 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4563 					     __LINE__, RACK_RTTS_REACHTARGET);
4564 			rack->r_ctl.rc_time_probertt_starts = us_cts;
4565 			if (rack->r_ctl.rc_time_probertt_starts == 0)
4566 				rack->r_ctl.rc_time_probertt_starts = 1;
4567 			/* Restore back to our rate we want to pace at in prtt */
4568 			rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
4569 		}
4570 		/*
4571 		 * Setup our end time, some number of gp_srtts plus 200ms.
4572 		 */
4573 		no_overflow = ((uint64_t)rack->r_ctl.rc_gp_srtt *
4574 			       (uint64_t)rack_probertt_gpsrtt_cnt_mul);
4575 		if (rack_probertt_gpsrtt_cnt_div)
4576 			endtime = (uint32_t)(no_overflow / (uint64_t)rack_probertt_gpsrtt_cnt_div);
4577 		else
4578 			endtime = 0;
4579 		endtime += rack_min_probertt_hold;
4580 		endtime += rack->r_ctl.rc_time_probertt_starts;
4581 		if (TSTMP_GEQ(us_cts,  endtime)) {
4582 			/* yes, exit probertt */
4583 			rack_exit_probertt(rack, us_cts);
4584 		}
4585 
4586 	} else if ((rack->rc_skip_timely == 0) &&
4587 		   (TSTMP_GT(us_cts, rack->r_ctl.rc_lower_rtt_us_cts)) &&
4588 		   ((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= rack_time_between_probertt)) {
4589 		/* Go into probertt, its been too long since we went lower */
4590 		rack_enter_probertt(rack, us_cts);
4591 	}
4592 }
4593 
4594 static void
rack_update_multiplier(struct tcp_rack * rack,int32_t timely_says,uint64_t last_bw_est,uint32_t rtt,int32_t rtt_diff)4595 rack_update_multiplier(struct tcp_rack *rack, int32_t timely_says, uint64_t last_bw_est,
4596 		       uint32_t rtt, int32_t rtt_diff)
4597 {
4598 	uint64_t cur_bw, up_bnd, low_bnd, subfr;
4599 	uint32_t losses;
4600 
4601 	if ((rack->rc_gp_dyn_mul == 0) ||
4602 	    (rack->use_fixed_rate) ||
4603 	    (rack->in_probe_rtt) ||
4604 	    (rack->rc_always_pace == 0)) {
4605 		/* No dynamic GP multiplier in play */
4606 		return;
4607 	}
4608 	losses = rack->r_ctl.rc_loss_count - rack->r_ctl.rc_loss_at_start;
4609 	cur_bw = rack_get_bw(rack);
4610 	/* Calculate our up and down range */
4611 	up_bnd = rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_up;
4612 	up_bnd /= 100;
4613 	up_bnd += rack->r_ctl.last_gp_comp_bw;
4614 
4615 	subfr = (uint64_t)rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_down;
4616 	subfr /= 100;
4617 	low_bnd = rack->r_ctl.last_gp_comp_bw - subfr;
4618 	if ((timely_says == 2) && (rack->r_ctl.rc_no_push_at_mrtt)) {
4619 		/*
4620 		 * This is the case where our RTT is above
4621 		 * the max target and we have been configured
4622 		 * to just do timely no bonus up stuff in that case.
4623 		 *
4624 		 * There are two configurations, set to 1, and we
4625 		 * just do timely if we are over our max. If its
4626 		 * set above 1 then we slam the multipliers down
4627 		 * to 100 and then decrement per timely.
4628 		 */
4629 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4630 				__LINE__, 3);
4631 		if (rack->r_ctl.rc_no_push_at_mrtt > 1)
4632 			rack_validate_multipliers_at_or_below_100(rack);
4633 		rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
4634 	} else if ((timely_says != 0) && (last_bw_est < low_bnd) && !losses) {
4635 		/*
4636 		 * We are decreasing this is a bit complicated this
4637 		 * means we are loosing ground. This could be
4638 		 * because another flow entered and we are competing
4639 		 * for b/w with it. This will push the RTT up which
4640 		 * makes timely unusable unless we want to get shoved
4641 		 * into a corner and just be backed off (the age
4642 		 * old problem with delay based CC).
4643 		 *
4644 		 * On the other hand if it was a route change we
4645 		 * would like to stay somewhat contained and not
4646 		 * blow out the buffers.
4647 		 */
4648 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4649 				__LINE__, 3);
4650 		rack->r_ctl.last_gp_comp_bw = cur_bw;
4651 		if (rack->rc_gp_bwred == 0) {
4652 			/* Go into reduction counting */
4653 			rack->rc_gp_bwred = 1;
4654 			rack->rc_gp_timely_dec_cnt = 0;
4655 		}
4656 		if (rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) {
4657 			/*
4658 			 * Push another time with a faster pacing
4659 			 * to try to gain back (we include override to
4660 			 * get a full raise factor).
4661 			 */
4662 			if ((rack->rc_gp_saw_ca && rack->r_ctl.rack_per_of_gp_ca <= rack_down_raise_thresh) ||
4663 			    (rack->rc_gp_saw_ss && rack->r_ctl.rack_per_of_gp_ss <= rack_down_raise_thresh) ||
4664 			    (timely_says == 0) ||
4665 			    (rack_down_raise_thresh == 0)) {
4666 				/*
4667 				 * Do an override up in b/w if we were
4668 				 * below the threshold or if the threshold
4669 				 * is zero we always do the raise.
4670 				 */
4671 				rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 1);
4672 			} else {
4673 				/* Log it stays the same */
4674 				rack_log_timely(rack,  0, last_bw_est, low_bnd, 0,
4675 						__LINE__, 11);
4676 			}
4677 			rack->rc_gp_timely_dec_cnt++;
4678 			/* We are not incrementing really no-count */
4679 			rack->rc_gp_incr = 0;
4680 			rack->rc_gp_timely_inc_cnt = 0;
4681 		} else {
4682 			/*
4683 			 * Lets just use the RTT
4684 			 * information and give up
4685 			 * pushing.
4686 			 */
4687 			goto use_timely;
4688 		}
4689 	} else if ((timely_says != 2) &&
4690 		    !losses &&
4691 		    (last_bw_est > up_bnd)) {
4692 		/*
4693 		 * We are increasing b/w lets keep going, updating
4694 		 * our b/w and ignoring any timely input, unless
4695 		 * of course we are at our max raise (if there is one).
4696 		 */
4697 
4698 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4699 				__LINE__, 3);
4700 		rack->r_ctl.last_gp_comp_bw = cur_bw;
4701 		if (rack->rc_gp_saw_ss &&
4702 		    rack->r_ctl.rack_per_upper_bound_ss &&
4703 		     (rack->r_ctl.rack_per_of_gp_ss == rack->r_ctl.rack_per_upper_bound_ss)) {
4704 			    /*
4705 			     * In cases where we can't go higher
4706 			     * we should just use timely.
4707 			     */
4708 			    goto use_timely;
4709 		}
4710 		if (rack->rc_gp_saw_ca &&
4711 		    rack->r_ctl.rack_per_upper_bound_ca &&
4712 		    (rack->r_ctl.rack_per_of_gp_ca == rack->r_ctl.rack_per_upper_bound_ca)) {
4713 			    /*
4714 			     * In cases where we can't go higher
4715 			     * we should just use timely.
4716 			     */
4717 			    goto use_timely;
4718 		}
4719 		rack->rc_gp_bwred = 0;
4720 		rack->rc_gp_timely_dec_cnt = 0;
4721 		/* You get a set number of pushes if timely is trying to reduce */
4722 		if ((rack->rc_gp_incr < rack_timely_max_push_rise) || (timely_says == 0)) {
4723 			rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4724 		} else {
4725 			/* Log it stays the same */
4726 			rack_log_timely(rack,  0, last_bw_est, up_bnd, 0,
4727 			    __LINE__, 12);
4728 		}
4729 		return;
4730 	} else {
4731 		/*
4732 		 * We are staying between the lower and upper range bounds
4733 		 * so use timely to decide.
4734 		 */
4735 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4736 				__LINE__, 3);
4737 use_timely:
4738 		if (timely_says) {
4739 			rack->rc_gp_incr = 0;
4740 			rack->rc_gp_timely_inc_cnt = 0;
4741 			if ((rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) &&
4742 			    !losses &&
4743 			    (last_bw_est < low_bnd)) {
4744 				/* We are loosing ground */
4745 				rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4746 				rack->rc_gp_timely_dec_cnt++;
4747 				/* We are not incrementing really no-count */
4748 				rack->rc_gp_incr = 0;
4749 				rack->rc_gp_timely_inc_cnt = 0;
4750 			} else
4751 				rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
4752 		} else {
4753 			rack->rc_gp_bwred = 0;
4754 			rack->rc_gp_timely_dec_cnt = 0;
4755 			rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4756 		}
4757 	}
4758 }
4759 
4760 static int32_t
rack_make_timely_judgement(struct tcp_rack * rack,uint32_t rtt,int32_t rtt_diff,uint32_t prev_rtt)4761 rack_make_timely_judgement(struct tcp_rack *rack, uint32_t rtt, int32_t rtt_diff, uint32_t prev_rtt)
4762 {
4763 	int32_t timely_says;
4764 	uint64_t log_mult, log_rtt_a_diff;
4765 
4766 	log_rtt_a_diff = rtt;
4767 	log_rtt_a_diff <<= 32;
4768 	log_rtt_a_diff |= (uint32_t)rtt_diff;
4769 	if (rtt >= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) *
4770 		    rack_gp_rtt_maxmul)) {
4771 		/* Reduce the b/w multiplier */
4772 		timely_says = 2;
4773 		log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
4774 		log_mult <<= 32;
4775 		log_mult |= prev_rtt;
4776 		rack_log_timely(rack,  timely_says, log_mult,
4777 				get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4778 				log_rtt_a_diff, __LINE__, 4);
4779 	} else if (rtt <= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
4780 			   ((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
4781 			    max(rack_gp_rtt_mindiv , 1)))) {
4782 		/* Increase the b/w multiplier */
4783 		log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
4784 			((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
4785 			 max(rack_gp_rtt_mindiv , 1));
4786 		log_mult <<= 32;
4787 		log_mult |= prev_rtt;
4788 		timely_says = 0;
4789 		rack_log_timely(rack,  timely_says, log_mult ,
4790 				get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4791 				log_rtt_a_diff, __LINE__, 5);
4792 	} else {
4793 		/*
4794 		 * Use a gradient to find it the timely gradient
4795 		 * is:
4796 		 * grad = rc_rtt_diff / min_rtt;
4797 		 *
4798 		 * anything below or equal to 0 will be
4799 		 * a increase indication. Anything above
4800 		 * zero is a decrease. Note we take care
4801 		 * of the actual gradient calculation
4802 		 * in the reduction (its not needed for
4803 		 * increase).
4804 		 */
4805 		log_mult = prev_rtt;
4806 		if (rtt_diff <= 0) {
4807 			/*
4808 			 * Rttdiff is less than zero, increase the
4809 			 * b/w multiplier (its 0 or negative)
4810 			 */
4811 			timely_says = 0;
4812 			rack_log_timely(rack,  timely_says, log_mult,
4813 					get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 6);
4814 		} else {
4815 			/* Reduce the b/w multiplier */
4816 			timely_says = 1;
4817 			rack_log_timely(rack,  timely_says, log_mult,
4818 					get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 7);
4819 		}
4820 	}
4821 	return (timely_says);
4822 }
4823 
4824 static __inline int
rack_in_gp_window(struct tcpcb * tp,struct rack_sendmap * rsm)4825 rack_in_gp_window(struct tcpcb *tp, struct rack_sendmap *rsm)
4826 {
4827 	if (SEQ_GEQ(rsm->r_start, tp->gput_seq) &&
4828 	    SEQ_LEQ(rsm->r_end, tp->gput_ack)) {
4829 		/**
4830 		 * This covers the case that the
4831 		 * resent is completely inside
4832 		 * the gp range or up to it.
4833 		 *      |----------------|
4834 		 *      |-----| <or>
4835 		 *            |----|
4836 		 *            <or>   |---|
4837 		 */
4838 		return (1);
4839 	} else if (SEQ_LT(rsm->r_start, tp->gput_seq) &&
4840 		   SEQ_GT(rsm->r_end, tp->gput_seq)){
4841 		/**
4842 		 * This covers the case of
4843 		 *      |--------------|
4844 		 *  |-------->|
4845 		 */
4846 		return (1);
4847 	} else if (SEQ_GEQ(rsm->r_start, tp->gput_seq) &&
4848 		   SEQ_LT(rsm->r_start, tp->gput_ack) &&
4849 		   SEQ_GEQ(rsm->r_end, tp->gput_ack)) {
4850 
4851 		/**
4852 		 * This covers the case of
4853 		 *      |--------------|
4854 		 *              |-------->|
4855 		 */
4856 		return (1);
4857 	}
4858 	return (0);
4859 }
4860 
4861 static __inline void
rack_mark_in_gp_win(struct tcpcb * tp,struct rack_sendmap * rsm)4862 rack_mark_in_gp_win(struct tcpcb *tp, struct rack_sendmap *rsm)
4863 {
4864 
4865 	if ((tp->t_flags & TF_GPUTINPROG) == 0)
4866 		return;
4867 	/*
4868 	 * We have a Goodput measurement in progress. Mark
4869 	 * the send if its within the window. If its not
4870 	 * in the window make sure it does not have the mark.
4871 	 */
4872 	if (rack_in_gp_window(tp, rsm))
4873 		rsm->r_flags |= RACK_IN_GP_WIN;
4874 	else
4875 		rsm->r_flags &= ~RACK_IN_GP_WIN;
4876 }
4877 
4878 static __inline void
rack_clear_gp_marks(struct tcpcb * tp,struct tcp_rack * rack)4879 rack_clear_gp_marks(struct tcpcb *tp, struct tcp_rack *rack)
4880 {
4881 	/* A GP measurement is ending, clear all marks on the send map*/
4882 	struct rack_sendmap *rsm = NULL;
4883 
4884 	rsm = tqhash_find(rack->r_ctl.tqh, tp->gput_seq);
4885 	if (rsm == NULL) {
4886 		rsm = tqhash_min(rack->r_ctl.tqh);
4887 	}
4888 	/* Nothing left? */
4889 	while ((rsm != NULL) && (SEQ_GEQ(tp->gput_ack, rsm->r_start))){
4890 		rsm->r_flags &= ~RACK_IN_GP_WIN;
4891 		rsm = tqhash_next(rack->r_ctl.tqh, rsm);
4892 	}
4893 }
4894 
4895 
4896 static __inline void
rack_tend_gp_marks(struct tcpcb * tp,struct tcp_rack * rack)4897 rack_tend_gp_marks(struct tcpcb *tp, struct tcp_rack *rack)
4898 {
4899 	struct rack_sendmap *rsm = NULL;
4900 
4901 	if (tp->snd_una == tp->snd_max) {
4902 		/* Nothing outstanding yet, nothing to do here */
4903 		return;
4904 	}
4905 	if (SEQ_GT(tp->gput_seq, tp->snd_una)) {
4906 		/*
4907 		 * We are measuring ahead of some outstanding
4908 		 * data. We need to walk through up until we get
4909 		 * to gp_seq marking so that no rsm is set incorrectly
4910 		 * with RACK_IN_GP_WIN.
4911 		 */
4912 		rsm = tqhash_min(rack->r_ctl.tqh);
4913 		while (rsm != NULL) {
4914 			rack_mark_in_gp_win(tp, rsm);
4915 			if (SEQ_GEQ(rsm->r_end, tp->gput_seq))
4916 				break;
4917 			rsm = tqhash_next(rack->r_ctl.tqh, rsm);
4918 		}
4919 	}
4920 	if (rsm == NULL) {
4921 		/*
4922 		 * Need to find the GP seq, if rsm is
4923 		 * set we stopped as we hit it.
4924 		 */
4925 		rsm = tqhash_find(rack->r_ctl.tqh, tp->gput_seq);
4926 		if (rsm == NULL)
4927 			return;
4928 		rack_mark_in_gp_win(tp, rsm);
4929 	}
4930 	/*
4931 	 * Now we may need to mark already sent rsm, ahead of
4932 	 * gput_seq in the window since they may have been sent
4933 	 * *before* we started our measurment. The rsm, if non-null
4934 	 * has been marked (note if rsm would have been NULL we would have
4935 	 * returned in the previous block). So we go to the next, and continue
4936 	 * until we run out of entries or we exceed the gp_ack value.
4937 	 */
4938 	rsm = tqhash_next(rack->r_ctl.tqh, rsm);
4939 	while (rsm) {
4940 		rack_mark_in_gp_win(tp, rsm);
4941 		if (SEQ_GT(rsm->r_end, tp->gput_ack))
4942 			break;
4943 		rsm = tqhash_next(rack->r_ctl.tqh, rsm);
4944 	}
4945 }
4946 
4947 static void
rack_log_gp_calc(struct tcp_rack * rack,uint32_t add_part,uint32_t sub_part,uint32_t srtt,uint64_t meas_bw,uint64_t utim,uint8_t meth,uint32_t line)4948 rack_log_gp_calc(struct tcp_rack *rack, uint32_t add_part, uint32_t sub_part, uint32_t srtt, uint64_t meas_bw, uint64_t utim, uint8_t meth, uint32_t line)
4949 {
4950 	if (tcp_bblogging_on(rack->rc_tp)) {
4951 		union tcp_log_stackspecific log;
4952 		struct timeval tv;
4953 
4954 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
4955 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
4956 		log.u_bbr.flex1 = add_part;
4957 		log.u_bbr.flex2 = sub_part;
4958 		log.u_bbr.flex3 = rack_wma_divisor;
4959 		log.u_bbr.flex4 = srtt;
4960 		log.u_bbr.flex7 = (uint16_t)line;
4961 		log.u_bbr.flex8 = meth;
4962 		log.u_bbr.delRate = rack->r_ctl.gp_bw;
4963 		log.u_bbr.cur_del_rate = meas_bw;
4964 		log.u_bbr.rttProp = utim;
4965 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
4966 		    &rack->rc_inp->inp_socket->so_rcv,
4967 		    &rack->rc_inp->inp_socket->so_snd,
4968 		    BBR_LOG_THRESH_CALC, 0,
4969 		    0, &log, false, &rack->r_ctl.act_rcv_time);
4970 	}
4971 }
4972 
4973 static void
rack_do_goodput_measurement(struct tcpcb * tp,struct tcp_rack * rack,tcp_seq th_ack,int line,uint8_t quality)4974 rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
4975 			    tcp_seq th_ack, int line, uint8_t quality)
4976 {
4977 	uint64_t tim, bytes_ps, stim, utim;
4978 	uint32_t segsiz, bytes, reqbytes, us_cts;
4979 	int32_t gput, new_rtt_diff, timely_says;
4980 	uint64_t  resid_bw, subpart = 0, addpart = 0, srtt;
4981 	int did_add = 0;
4982 
4983 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
4984 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
4985 	if (TSTMP_GEQ(us_cts, tp->gput_ts))
4986 		tim = us_cts - tp->gput_ts;
4987 	else
4988 		tim = 0;
4989 	if (rack->r_ctl.rc_gp_cumack_ts > rack->r_ctl.rc_gp_output_ts)
4990 		stim = rack->r_ctl.rc_gp_cumack_ts - rack->r_ctl.rc_gp_output_ts;
4991 	else
4992 		stim = 0;
4993 	/*
4994 	 * Use the larger of the send time or ack time. This prevents us
4995 	 * from being influenced by ack artifacts to come up with too
4996 	 * high of measurement. Note that since we are spanning over many more
4997 	 * bytes in most of our measurements hopefully that is less likely to
4998 	 * occur.
4999 	 */
5000 	if (tim > stim)
5001 		utim = max(tim, 1);
5002 	else
5003 		utim = max(stim, 1);
5004 	reqbytes = min(rc_init_window(rack), (MIN_GP_WIN * segsiz));
5005 	rack_log_gpset(rack, th_ack, us_cts, rack->r_ctl.rc_gp_cumack_ts, __LINE__, 3, NULL);
5006 	if ((tim == 0) && (stim == 0)) {
5007 		/*
5008 		 * Invalid measurement time, maybe
5009 		 * all on one ack/one send?
5010 		 */
5011 		bytes = 0;
5012 		bytes_ps = 0;
5013 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
5014 					   0, 0, 0, 10, __LINE__, NULL, quality);
5015 		goto skip_measurement;
5016 	}
5017 	if (rack->r_ctl.rc_gp_lowrtt == 0xffffffff) {
5018 		/* We never made a us_rtt measurement? */
5019 		bytes = 0;
5020 		bytes_ps = 0;
5021 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
5022 					   0, 0, 0, 10, __LINE__, NULL, quality);
5023 		goto skip_measurement;
5024 	}
5025 	/*
5026 	 * Calculate the maximum possible b/w this connection
5027 	 * could have. We base our calculation on the lowest
5028 	 * rtt we have seen during the measurement and the
5029 	 * largest rwnd the client has given us in that time. This
5030 	 * forms a BDP that is the maximum that we could ever
5031 	 * get to the client. Anything larger is not valid.
5032 	 *
5033 	 * I originally had code here that rejected measurements
5034 	 * where the time was less than 1/2 the latest us_rtt.
5035 	 * But after thinking on that I realized its wrong since
5036 	 * say you had a 150Mbps or even 1Gbps link, and you
5037 	 * were a long way away.. example I am in Europe (100ms rtt)
5038 	 * talking to my 1Gbps link in S.C. Now measuring say 150,000
5039 	 * bytes my time would be 1.2ms, and yet my rtt would say
5040 	 * the measurement was invalid the time was < 50ms. The
5041 	 * same thing is true for 150Mb (8ms of time).
5042 	 *
5043 	 * A better way I realized is to look at what the maximum
5044 	 * the connection could possibly do. This is gated on
5045 	 * the lowest RTT we have seen and the highest rwnd.
5046 	 * We should in theory never exceed that, if we are
5047 	 * then something on the path is storing up packets
5048 	 * and then feeding them all at once to our endpoint
5049 	 * messing up our measurement.
5050 	 */
5051 	rack->r_ctl.last_max_bw = rack->r_ctl.rc_gp_high_rwnd;
5052 	rack->r_ctl.last_max_bw *= HPTS_USEC_IN_SEC;
5053 	rack->r_ctl.last_max_bw /= rack->r_ctl.rc_gp_lowrtt;
5054 	if (SEQ_LT(th_ack, tp->gput_seq)) {
5055 		/* No measurement can be made */
5056 		bytes = 0;
5057 		bytes_ps = 0;
5058 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
5059 					   0, 0, 0, 10, __LINE__, NULL, quality);
5060 		goto skip_measurement;
5061 	} else
5062 		bytes = (th_ack - tp->gput_seq);
5063 	bytes_ps = (uint64_t)bytes;
5064 	/*
5065 	 * Don't measure a b/w for pacing unless we have gotten at least
5066 	 * an initial windows worth of data in this measurement interval.
5067 	 *
5068 	 * Small numbers of bytes get badly influenced by delayed ack and
5069 	 * other artifacts. Note we take the initial window or our
5070 	 * defined minimum GP (defaulting to 10 which hopefully is the
5071 	 * IW).
5072 	 */
5073 	if (rack->rc_gp_filled == 0) {
5074 		/*
5075 		 * The initial estimate is special. We
5076 		 * have blasted out an IW worth of packets
5077 		 * without a real valid ack ts results. We
5078 		 * then setup the app_limited_needs_set flag,
5079 		 * this should get the first ack in (probably 2
5080 		 * MSS worth) to be recorded as the timestamp.
5081 		 * We thus allow a smaller number of bytes i.e.
5082 		 * IW - 2MSS.
5083 		 */
5084 		reqbytes -= (2 * segsiz);
5085 		/* Also lets fill previous for our first measurement to be neutral */
5086 		rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
5087 	}
5088 	if ((bytes_ps < reqbytes) || rack->app_limited_needs_set) {
5089 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
5090 					   rack->r_ctl.rc_app_limited_cnt,
5091 					   0, 0, 10, __LINE__, NULL, quality);
5092 		goto skip_measurement;
5093 	}
5094 	/*
5095 	 * We now need to calculate the Timely like status so
5096 	 * we can update (possibly) the b/w multipliers.
5097 	 */
5098 	new_rtt_diff = (int32_t)rack->r_ctl.rc_gp_srtt - (int32_t)rack->r_ctl.rc_prev_gp_srtt;
5099 	if (rack->rc_gp_filled == 0) {
5100 		/* No previous reading */
5101 		rack->r_ctl.rc_rtt_diff = new_rtt_diff;
5102 	} else {
5103 		if (rack->measure_saw_probe_rtt == 0) {
5104 			/*
5105 			 * We don't want a probertt to be counted
5106 			 * since it will be negative incorrectly. We
5107 			 * expect to be reducing the RTT when we
5108 			 * pace at a slower rate.
5109 			 */
5110 			rack->r_ctl.rc_rtt_diff -= (rack->r_ctl.rc_rtt_diff / 8);
5111 			rack->r_ctl.rc_rtt_diff += (new_rtt_diff / 8);
5112 		}
5113 	}
5114 	timely_says = rack_make_timely_judgement(rack,
5115 	    rack->r_ctl.rc_gp_srtt,
5116 	    rack->r_ctl.rc_rtt_diff,
5117 	    rack->r_ctl.rc_prev_gp_srtt
5118 	);
5119 	bytes_ps *= HPTS_USEC_IN_SEC;
5120 	bytes_ps /= utim;
5121 	if (bytes_ps > rack->r_ctl.last_max_bw) {
5122 		/*
5123 		 * Something is on path playing
5124 		 * since this b/w is not possible based
5125 		 * on our BDP (highest rwnd and lowest rtt
5126 		 * we saw in the measurement window).
5127 		 *
5128 		 * Another option here would be to
5129 		 * instead skip the measurement.
5130 		 */
5131 		rack_log_pacing_delay_calc(rack, bytes, reqbytes,
5132 					   bytes_ps, rack->r_ctl.last_max_bw, 0,
5133 					   11, __LINE__, NULL, quality);
5134 		bytes_ps = rack->r_ctl.last_max_bw;
5135 	}
5136 	/* We store gp for b/w in bytes per second */
5137 	if (rack->rc_gp_filled == 0) {
5138 		/* Initial measurement */
5139 		if (bytes_ps) {
5140 			rack->r_ctl.gp_bw = bytes_ps;
5141 			rack->rc_gp_filled = 1;
5142 			rack->r_ctl.num_measurements = 1;
5143 			rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
5144 		} else {
5145 			rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
5146 						   rack->r_ctl.rc_app_limited_cnt,
5147 						   0, 0, 10, __LINE__, NULL, quality);
5148 		}
5149 		if (tcp_in_hpts(rack->rc_tp) &&
5150 		    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
5151 			/*
5152 			 * Ok we can't trust the pacer in this case
5153 			 * where we transition from un-paced to paced.
5154 			 * Or for that matter when the burst mitigation
5155 			 * was making a wild guess and got it wrong.
5156 			 * Stop the pacer and clear up all the aggregate
5157 			 * delays etc.
5158 			 */
5159 			tcp_hpts_remove(rack->rc_tp);
5160 			rack->r_ctl.rc_hpts_flags = 0;
5161 			rack->r_ctl.rc_last_output_to = 0;
5162 		}
5163 		did_add = 2;
5164 	} else if (rack->r_ctl.num_measurements < RACK_REQ_AVG) {
5165 		/* Still a small number run an average */
5166 		rack->r_ctl.gp_bw += bytes_ps;
5167 		addpart = rack->r_ctl.num_measurements;
5168 		rack->r_ctl.num_measurements++;
5169 		if (rack->r_ctl.num_measurements >= RACK_REQ_AVG) {
5170 			/* We have collected enough to move forward */
5171 			rack->r_ctl.gp_bw /= (uint64_t)rack->r_ctl.num_measurements;
5172 		}
5173 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
5174 		did_add = 3;
5175 	} else {
5176 		/*
5177 		 * We want to take 1/wma of the goodput and add in to 7/8th
5178 		 * of the old value weighted by the srtt. So if your measurement
5179 		 * period is say 2 SRTT's long you would get 1/4 as the
5180 		 * value, if it was like 1/2 SRTT then you would get 1/16th.
5181 		 *
5182 		 * But we must be careful not to take too much i.e. if the
5183 		 * srtt is say 20ms and the measurement is taken over
5184 		 * 400ms our weight would be 400/20 i.e. 20. On the
5185 		 * other hand if we get a measurement over 1ms with a
5186 		 * 10ms rtt we only want to take a much smaller portion.
5187 		 */
5188 		uint8_t meth;
5189 
5190 		if (rack->r_ctl.num_measurements < 0xff) {
5191 			rack->r_ctl.num_measurements++;
5192 		}
5193 		srtt = (uint64_t)tp->t_srtt;
5194 		if (srtt == 0) {
5195 			/*
5196 			 * Strange why did t_srtt go back to zero?
5197 			 */
5198 			if (rack->r_ctl.rc_rack_min_rtt)
5199 				srtt = rack->r_ctl.rc_rack_min_rtt;
5200 			else
5201 				srtt = HPTS_USEC_IN_MSEC;
5202 		}
5203 		/*
5204 		 * XXXrrs: Note for reviewers, in playing with
5205 		 * dynamic pacing I discovered this GP calculation
5206 		 * as done originally leads to some undesired results.
5207 		 * Basically you can get longer measurements contributing
5208 		 * too much to the WMA. Thus I changed it if you are doing
5209 		 * dynamic adjustments to only do the aportioned adjustment
5210 		 * if we have a very small (time wise) measurement. Longer
5211 		 * measurements just get there weight (defaulting to 1/8)
5212 		 * add to the WMA. We may want to think about changing
5213 		 * this to always do that for both sides i.e. dynamic
5214 		 * and non-dynamic... but considering lots of folks
5215 		 * were playing with this I did not want to change the
5216 		 * calculation per.se. without your thoughts.. Lawerence?
5217 		 * Peter??
5218 		 */
5219 		if (rack->rc_gp_dyn_mul == 0) {
5220 			subpart = rack->r_ctl.gp_bw * utim;
5221 			subpart /= (srtt * 8);
5222 			if (subpart < (rack->r_ctl.gp_bw / 2)) {
5223 				/*
5224 				 * The b/w update takes no more
5225 				 * away then 1/2 our running total
5226 				 * so factor it in.
5227 				 */
5228 				addpart = bytes_ps * utim;
5229 				addpart /= (srtt * 8);
5230 				meth = 1;
5231 			} else {
5232 				/*
5233 				 * Don't allow a single measurement
5234 				 * to account for more than 1/2 of the
5235 				 * WMA. This could happen on a retransmission
5236 				 * where utim becomes huge compared to
5237 				 * srtt (multiple retransmissions when using
5238 				 * the sending rate which factors in all the
5239 				 * transmissions from the first one).
5240 				 */
5241 				subpart = rack->r_ctl.gp_bw / 2;
5242 				addpart = bytes_ps / 2;
5243 				meth = 2;
5244 			}
5245 			rack_log_gp_calc(rack, addpart, subpart, srtt, bytes_ps, utim, meth, __LINE__);
5246 			resid_bw = rack->r_ctl.gp_bw - subpart;
5247 			rack->r_ctl.gp_bw = resid_bw + addpart;
5248 			did_add = 1;
5249 		} else {
5250 			if ((utim / srtt) <= 1) {
5251 				/*
5252 				 * The b/w update was over a small period
5253 				 * of time. The idea here is to prevent a small
5254 				 * measurement time period from counting
5255 				 * too much. So we scale it based on the
5256 				 * time so it attributes less than 1/rack_wma_divisor
5257 				 * of its measurement.
5258 				 */
5259 				subpart = rack->r_ctl.gp_bw * utim;
5260 				subpart /= (srtt * rack_wma_divisor);
5261 				addpart = bytes_ps * utim;
5262 				addpart /= (srtt * rack_wma_divisor);
5263 				meth = 3;
5264 			} else {
5265 				/*
5266 				 * The scaled measurement was long
5267 				 * enough so lets just add in the
5268 				 * portion of the measurement i.e. 1/rack_wma_divisor
5269 				 */
5270 				subpart = rack->r_ctl.gp_bw / rack_wma_divisor;
5271 				addpart = bytes_ps / rack_wma_divisor;
5272 				meth = 4;
5273 			}
5274 			if ((rack->measure_saw_probe_rtt == 0) ||
5275 		            (bytes_ps > rack->r_ctl.gp_bw)) {
5276 				/*
5277 				 * For probe-rtt we only add it in
5278 				 * if its larger, all others we just
5279 				 * add in.
5280 				 */
5281 				did_add = 1;
5282 				rack_log_gp_calc(rack, addpart, subpart, srtt, bytes_ps, utim, meth, __LINE__);
5283 				resid_bw = rack->r_ctl.gp_bw - subpart;
5284 				rack->r_ctl.gp_bw = resid_bw + addpart;
5285 			}
5286 		}
5287 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
5288 	}
5289 	/*
5290 	 * We only watch the growth of the GP during the initial startup
5291 	 * or first-slowstart that ensues. If we ever needed to watch
5292 	 * growth of gp outside of that period all we need to do is
5293 	 * remove the first clause of this if (rc_initial_ss_comp).
5294 	 */
5295 	if ((rack->rc_initial_ss_comp == 0) &&
5296 	    (rack->r_ctl.num_measurements >= RACK_REQ_AVG)) {
5297 		uint64_t gp_est;
5298 
5299 		gp_est = bytes_ps;
5300 		if (tcp_bblogging_on(rack->rc_tp)) {
5301 			union tcp_log_stackspecific log;
5302 			struct timeval tv;
5303 
5304 			memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5305 			log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5306 			log.u_bbr.flex1 = rack->r_ctl.current_round;
5307 			log.u_bbr.flex2 = rack->r_ctl.last_rnd_of_gp_rise;
5308 			log.u_bbr.delRate = gp_est;
5309 			log.u_bbr.cur_del_rate = rack->r_ctl.last_gpest;
5310 			log.u_bbr.flex8 = 41;
5311 			(void)tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
5312 					    0, &log, false, NULL, __func__, __LINE__,&tv);
5313 		}
5314 		if ((rack->r_ctl.num_measurements == RACK_REQ_AVG) ||
5315 		    (rack->r_ctl.last_gpest == 0)) {
5316 			/*
5317 			 * The round we get our measurement averaging going
5318 			 * is the base round so it always is the source point
5319 			 * for when we had our first increment. From there on
5320 			 * we only record the round that had a rise.
5321 			 */
5322 			rack->r_ctl.last_rnd_of_gp_rise = rack->r_ctl.current_round;
5323 			rack->r_ctl.last_gpest = rack->r_ctl.gp_bw;
5324 		} else if (gp_est >= rack->r_ctl.last_gpest) {
5325 			/*
5326 			 * Test to see if its gone up enough
5327 			 * to set the round count up to now. Note
5328 			 * that on the seeding of the 4th measurement we
5329 			 */
5330 			gp_est *= 1000;
5331 			gp_est /= rack->r_ctl.last_gpest;
5332 			if ((uint32_t)gp_est > rack->r_ctl.gp_gain_req) {
5333 				/*
5334 				 * We went up enough to record the round.
5335 				 */
5336 				if (tcp_bblogging_on(rack->rc_tp)) {
5337 					union tcp_log_stackspecific log;
5338 					struct timeval tv;
5339 
5340 					memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5341 					log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5342 					log.u_bbr.flex1 = rack->r_ctl.current_round;
5343 					log.u_bbr.flex2 = (uint32_t)gp_est;
5344 					log.u_bbr.flex3 = rack->r_ctl.gp_gain_req;
5345 					log.u_bbr.delRate = gp_est;
5346 					log.u_bbr.cur_del_rate = rack->r_ctl.last_gpest;
5347 					log.u_bbr.flex8 = 42;
5348 					(void)tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
5349 							    0, &log, false, NULL, __func__, __LINE__,&tv);
5350 				}
5351 				rack->r_ctl.last_rnd_of_gp_rise = rack->r_ctl.current_round;
5352 				if (rack->r_ctl.use_gp_not_last == 1)
5353 					rack->r_ctl.last_gpest = rack->r_ctl.gp_bw;
5354 				else
5355 					rack->r_ctl.last_gpest = bytes_ps;
5356 			}
5357 		}
5358 	}
5359 	if ((rack->gp_ready == 0) &&
5360 	    (rack->r_ctl.num_measurements >= rack->r_ctl.req_measurements)) {
5361 		/* We have enough measurements now */
5362 		rack->gp_ready = 1;
5363 		if (rack->dgp_on ||
5364 		    rack->rack_hibeta)
5365 			rack_set_cc_pacing(rack);
5366 		if (rack->defer_options)
5367 			rack_apply_deferred_options(rack);
5368 	}
5369 	rack_log_pacing_delay_calc(rack, subpart, addpart, bytes_ps, stim,
5370 				   rack_get_bw(rack), 22, did_add, NULL, quality);
5371 	/* We do not update any multipliers if we are in or have seen a probe-rtt */
5372 
5373 	if ((rack->measure_saw_probe_rtt == 0) &&
5374 	    rack->rc_gp_rtt_set) {
5375 		if (rack->rc_skip_timely == 0) {
5376 			rack_update_multiplier(rack, timely_says, bytes_ps,
5377 					       rack->r_ctl.rc_gp_srtt,
5378 					       rack->r_ctl.rc_rtt_diff);
5379 		}
5380 	}
5381 	rack_log_pacing_delay_calc(rack, bytes, tim, bytes_ps, stim,
5382 				   rack_get_bw(rack), 3, line, NULL, quality);
5383 	rack_log_pacing_delay_calc(rack,
5384 				   bytes, /* flex2 */
5385 				   tim, /* flex1 */
5386 				   bytes_ps, /* bw_inuse */
5387 				   rack->r_ctl.gp_bw, /* delRate */
5388 				   rack_get_lt_bw(rack), /* rttProp */
5389 				   20, line, NULL, 0);
5390 	/* reset the gp srtt and setup the new prev */
5391 	rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
5392 	/* Record the lost count for the next measurement */
5393 	rack->r_ctl.rc_loss_at_start = rack->r_ctl.rc_loss_count;
5394 skip_measurement:
5395 	/*
5396 	 * We restart our diffs based on the gpsrtt in the
5397 	 * measurement window.
5398 	 */
5399 	rack->rc_gp_rtt_set = 0;
5400 	rack->rc_gp_saw_rec = 0;
5401 	rack->rc_gp_saw_ca = 0;
5402 	rack->rc_gp_saw_ss = 0;
5403 	rack->rc_dragged_bottom = 0;
5404 	if (quality == RACK_QUALITY_HIGH) {
5405 		/*
5406 		 * Gput in the stats world is in kbps where bytes_ps is
5407 		 * bytes per second so we do ((x * 8)/ 1000).
5408 		 */
5409 		gput = (int32_t)((bytes_ps << 3) / (uint64_t)1000);
5410 #ifdef STATS
5411 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_GPUT,
5412 					 gput);
5413 		/*
5414 		 * XXXLAS: This is a temporary hack, and should be
5415 		 * chained off VOI_TCP_GPUT when stats(9) grows an
5416 		 * API to deal with chained VOIs.
5417 		 */
5418 		if (tp->t_stats_gput_prev > 0)
5419 			stats_voi_update_abs_s32(tp->t_stats,
5420 						 VOI_TCP_GPUT_ND,
5421 						 ((gput - tp->t_stats_gput_prev) * 100) /
5422 						 tp->t_stats_gput_prev);
5423 #endif
5424 		tp->t_stats_gput_prev = gput;
5425 	}
5426 	tp->t_flags &= ~TF_GPUTINPROG;
5427 	/*
5428 	 * Now are we app limited now and there is space from where we
5429 	 * were to where we want to go?
5430 	 *
5431 	 * We don't do the other case i.e. non-applimited here since
5432 	 * the next send will trigger us picking up the missing data.
5433 	 */
5434 	if (rack->r_ctl.rc_first_appl &&
5435 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
5436 	    rack->r_ctl.rc_app_limited_cnt &&
5437 	    (SEQ_GT(rack->r_ctl.rc_first_appl->r_start, th_ack)) &&
5438 	    ((rack->r_ctl.rc_first_appl->r_end - th_ack) >
5439 	     max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
5440 		/*
5441 		 * Yep there is enough outstanding to make a measurement here.
5442 		 */
5443 		struct rack_sendmap *rsm;
5444 
5445 		rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
5446 		rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
5447 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
5448 		rack->app_limited_needs_set = 0;
5449 		tp->gput_seq = th_ack;
5450 		if (rack->in_probe_rtt)
5451 			rack->measure_saw_probe_rtt = 1;
5452 		else if ((rack->measure_saw_probe_rtt) &&
5453 			 (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
5454 			rack->measure_saw_probe_rtt = 0;
5455 		if ((rack->r_ctl.rc_first_appl->r_end - th_ack) >= rack_get_measure_window(tp, rack)) {
5456 			/* There is a full window to gain info from */
5457 			tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
5458 		} else {
5459 			/* We can only measure up to the applimited point */
5460 			tp->gput_ack = tp->gput_seq + (rack->r_ctl.rc_first_appl->r_end - th_ack);
5461 			if ((tp->gput_ack - tp->gput_seq) < (MIN_GP_WIN * segsiz)) {
5462 				/*
5463 				 * We don't have enough to make a measurement.
5464 				 */
5465 				tp->t_flags &= ~TF_GPUTINPROG;
5466 				rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
5467 							   0, 0, 0, 6, __LINE__, NULL, quality);
5468 				return;
5469 			}
5470 		}
5471 		if (tp->t_state >= TCPS_FIN_WAIT_1) {
5472 			/*
5473 			 * We will get no more data into the SB
5474 			 * this means we need to have the data available
5475 			 * before we start a measurement.
5476 			 */
5477 			if (sbavail(&tptosocket(tp)->so_snd) < (tp->gput_ack - tp->gput_seq)) {
5478 				/* Nope not enough data. */
5479 				return;
5480 			}
5481 		}
5482 		tp->t_flags |= TF_GPUTINPROG;
5483 		/*
5484 		 * Now we need to find the timestamp of the send at tp->gput_seq
5485 		 * for the send based measurement.
5486 		 */
5487 		rack->r_ctl.rc_gp_cumack_ts = 0;
5488 		rsm = tqhash_find(rack->r_ctl.tqh, tp->gput_seq);
5489 		if (rsm) {
5490 			/* Ok send-based limit is set */
5491 			if (SEQ_LT(rsm->r_start, tp->gput_seq)) {
5492 				/*
5493 				 * Move back to include the earlier part
5494 				 * so our ack time lines up right (this may
5495 				 * make an overlapping measurement but thats
5496 				 * ok).
5497 				 */
5498 				tp->gput_seq = rsm->r_start;
5499 			}
5500 			if (rsm->r_flags & RACK_ACKED) {
5501 				struct rack_sendmap *nrsm;
5502 
5503 				tp->gput_ts = (uint32_t)rsm->r_ack_arrival;
5504 				tp->gput_seq = rsm->r_end;
5505 				nrsm = tqhash_next(rack->r_ctl.tqh, rsm);
5506 				if (nrsm)
5507 					rsm = nrsm;
5508 				else {
5509 					rack->app_limited_needs_set = 1;
5510 				}
5511 			} else
5512 				rack->app_limited_needs_set = 1;
5513 			/* We always go from the first send */
5514 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[0];
5515 		} else {
5516 			/*
5517 			 * If we don't find the rsm due to some
5518 			 * send-limit set the current time, which
5519 			 * basically disables the send-limit.
5520 			 */
5521 			struct timeval tv;
5522 
5523 			microuptime(&tv);
5524 			rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
5525 		}
5526 		rack_tend_gp_marks(tp, rack);
5527 		rack_log_pacing_delay_calc(rack,
5528 					   tp->gput_seq,
5529 					   tp->gput_ack,
5530 					   (uint64_t)rsm,
5531 					   tp->gput_ts,
5532 					   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) | (uint64_t)rack->r_ctl.rc_gp_output_ts),
5533 					   9,
5534 					   __LINE__, rsm, quality);
5535 		rack_log_gpset(rack, tp->gput_ack, 0, 0, __LINE__, 1, NULL);
5536 	} else {
5537 		/*
5538 		 * To make sure proper timestamp merging occurs, we need to clear
5539 		 * all GP marks if we don't start a measurement.
5540 		 */
5541 		rack_clear_gp_marks(tp, rack);
5542 	}
5543 }
5544 
5545 /*
5546  * CC wrapper hook functions
5547  */
5548 static void
rack_ack_received(struct tcpcb * tp,struct tcp_rack * rack,uint32_t th_ack,uint16_t nsegs,uint16_t type,int32_t post_recovery)5549 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack, uint32_t th_ack, uint16_t nsegs,
5550     uint16_t type, int32_t post_recovery)
5551 {
5552 	uint32_t prior_cwnd, acked;
5553 	struct tcp_log_buffer *lgb = NULL;
5554 	uint8_t labc_to_use, quality;
5555 
5556 	INP_WLOCK_ASSERT(tptoinpcb(tp));
5557 	tp->t_ccv.nsegs = nsegs;
5558 	acked = tp->t_ccv.bytes_this_ack = (th_ack - tp->snd_una);
5559 	if ((post_recovery) && (rack->r_ctl.rc_early_recovery_segs)) {
5560 		uint32_t max;
5561 
5562 		max = rack->r_ctl.rc_early_recovery_segs * ctf_fixed_maxseg(tp);
5563 		if (tp->t_ccv.bytes_this_ack > max) {
5564 			tp->t_ccv.bytes_this_ack = max;
5565 		}
5566 	}
5567 #ifdef STATS
5568 	stats_voi_update_abs_s32(tp->t_stats, VOI_TCP_CALCFRWINDIFF,
5569 	    ((int32_t)rack->r_ctl.cwnd_to_use) - tp->snd_wnd);
5570 #endif
5571 	if ((th_ack == tp->snd_max) && rack->lt_bw_up) {
5572 		/*
5573 		 * We will ack all the data, time to end any
5574 		 * lt_bw_up we have running until something
5575 		 * new is sent. Note we need to use the actual
5576 		 * ack_rcv_time which with pacing may be different.
5577 		 */
5578 		uint64_t tmark;
5579 
5580 		rack->r_ctl.lt_bw_bytes += (tp->snd_max - rack->r_ctl.lt_seq);
5581 		rack->r_ctl.lt_seq = tp->snd_max;
5582 		tmark = tcp_tv_to_lusectick(&rack->r_ctl.act_rcv_time);
5583 		if (tmark >= rack->r_ctl.lt_timemark) {
5584 			rack->r_ctl.lt_bw_time += (tmark - rack->r_ctl.lt_timemark);
5585 		}
5586 		rack->r_ctl.lt_timemark = tmark;
5587 		rack->lt_bw_up = 0;
5588 	}
5589 	quality = RACK_QUALITY_NONE;
5590 	if ((tp->t_flags & TF_GPUTINPROG) &&
5591 	    rack_enough_for_measurement(tp, rack, th_ack, &quality)) {
5592 		/* Measure the Goodput */
5593 		rack_do_goodput_measurement(tp, rack, th_ack, __LINE__, quality);
5594 	}
5595 	/* Which way our we limited, if not cwnd limited no advance in CA */
5596 	if (tp->snd_cwnd <= tp->snd_wnd)
5597 		tp->t_ccv.flags |= CCF_CWND_LIMITED;
5598 	else
5599 		tp->t_ccv.flags &= ~CCF_CWND_LIMITED;
5600 	if (tp->snd_cwnd > tp->snd_ssthresh) {
5601 		tp->t_bytes_acked += min(tp->t_ccv.bytes_this_ack,
5602 			 nsegs * V_tcp_abc_l_var * ctf_fixed_maxseg(tp));
5603 		/* For the setting of a window past use the actual scwnd we are using */
5604 		if (tp->t_bytes_acked >= rack->r_ctl.cwnd_to_use) {
5605 			tp->t_bytes_acked -= rack->r_ctl.cwnd_to_use;
5606 			tp->t_ccv.flags |= CCF_ABC_SENTAWND;
5607 		}
5608 	} else {
5609 		tp->t_ccv.flags &= ~CCF_ABC_SENTAWND;
5610 		tp->t_bytes_acked = 0;
5611 	}
5612 	prior_cwnd = tp->snd_cwnd;
5613 	if ((post_recovery == 0) || (rack_max_abc_post_recovery == 0) || rack->r_use_labc_for_rec ||
5614 	    (rack_client_low_buf && rack->client_bufferlvl &&
5615 	    (rack->client_bufferlvl < rack_client_low_buf)))
5616 		labc_to_use = rack->rc_labc;
5617 	else
5618 		labc_to_use = rack_max_abc_post_recovery;
5619 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
5620 		union tcp_log_stackspecific log;
5621 		struct timeval tv;
5622 
5623 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5624 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5625 		log.u_bbr.flex1 = th_ack;
5626 		log.u_bbr.flex2 = tp->t_ccv.flags;
5627 		log.u_bbr.flex3 = tp->t_ccv.bytes_this_ack;
5628 		log.u_bbr.flex4 = tp->t_ccv.nsegs;
5629 		log.u_bbr.flex5 = labc_to_use;
5630 		log.u_bbr.flex6 = prior_cwnd;
5631 		log.u_bbr.flex7 = V_tcp_do_newsack;
5632 		log.u_bbr.flex8 = 1;
5633 		lgb = tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
5634 				     0, &log, false, NULL, __func__, __LINE__,&tv);
5635 	}
5636 	if (CC_ALGO(tp)->ack_received != NULL) {
5637 		/* XXXLAS: Find a way to live without this */
5638 		tp->t_ccv.curack = th_ack;
5639 		tp->t_ccv.labc = labc_to_use;
5640 		tp->t_ccv.flags |= CCF_USE_LOCAL_ABC;
5641 		CC_ALGO(tp)->ack_received(&tp->t_ccv, type);
5642 	}
5643 	if (lgb) {
5644 		lgb->tlb_stackinfo.u_bbr.flex6 = tp->snd_cwnd;
5645 	}
5646 	if (rack->r_must_retran) {
5647 		if (SEQ_GEQ(th_ack, rack->r_ctl.rc_snd_max_at_rto)) {
5648 			/*
5649 			 * We now are beyond the rxt point so lets disable
5650 			 * the flag.
5651 			 */
5652 			rack->r_ctl.rc_out_at_rto = 0;
5653 			rack->r_must_retran = 0;
5654 		} else if ((prior_cwnd + ctf_fixed_maxseg(tp)) <= tp->snd_cwnd) {
5655 			/*
5656 			 * Only decrement the rc_out_at_rto if the cwnd advances
5657 			 * at least a whole segment. Otherwise next time the peer
5658 			 * acks, we won't be able to send this generaly happens
5659 			 * when we are in Congestion Avoidance.
5660 			 */
5661 			if (acked <= rack->r_ctl.rc_out_at_rto){
5662 				rack->r_ctl.rc_out_at_rto -= acked;
5663 			} else {
5664 				rack->r_ctl.rc_out_at_rto = 0;
5665 			}
5666 		}
5667 	}
5668 #ifdef STATS
5669 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_LCWIN, rack->r_ctl.cwnd_to_use);
5670 #endif
5671 	if (rack->r_ctl.rc_rack_largest_cwnd < rack->r_ctl.cwnd_to_use) {
5672 		rack->r_ctl.rc_rack_largest_cwnd = rack->r_ctl.cwnd_to_use;
5673 	}
5674 	if ((rack->rc_initial_ss_comp == 0) &&
5675 	    (tp->snd_cwnd >= tp->snd_ssthresh)) {
5676 		/*
5677 		 * The cwnd has grown beyond ssthresh we have
5678 		 * entered ca and completed our first Slowstart.
5679 		 */
5680 		rack->rc_initial_ss_comp = 1;
5681 	}
5682 }
5683 
5684 static void
tcp_rack_partialack(struct tcpcb * tp)5685 tcp_rack_partialack(struct tcpcb *tp)
5686 {
5687 	struct tcp_rack *rack;
5688 
5689 	rack = (struct tcp_rack *)tp->t_fb_ptr;
5690 	INP_WLOCK_ASSERT(tptoinpcb(tp));
5691 	/*
5692 	 * If we are doing PRR and have enough
5693 	 * room to send <or> we are pacing and prr
5694 	 * is disabled we will want to see if we
5695 	 * can send data (by setting r_wanted_output to
5696 	 * true).
5697 	 */
5698 	if ((rack->r_ctl.rc_prr_sndcnt > 0) ||
5699 	    rack->rack_no_prr)
5700 		rack->r_wanted_output = 1;
5701 }
5702 
5703 static inline uint64_t
rack_get_rxt_per(uint64_t snds,uint64_t rxts)5704 rack_get_rxt_per(uint64_t snds,  uint64_t rxts)
5705 {
5706 	uint64_t rxt_per;
5707 
5708 	if (snds > 0) {
5709 		rxt_per = rxts * 1000;
5710 		rxt_per /= snds;
5711 	} else {
5712 		/* This is an unlikely path */
5713 		if (rxts) {
5714 			/* Its the max it was all re-transmits */
5715 			rxt_per = 0xffffffffffffffff;
5716 		} else {
5717 			rxt_per = 0;
5718 		}
5719 	}
5720 	return (rxt_per);
5721 }
5722 
5723 static void
policer_detection_log(struct tcp_rack * rack,uint32_t flex1,uint32_t flex2,uint32_t flex3,uint32_t flex4,uint8_t flex8)5724 policer_detection_log(struct tcp_rack *rack, uint32_t flex1, uint32_t flex2, uint32_t flex3, uint32_t flex4, uint8_t flex8)
5725 {
5726 	if (tcp_bblogging_on(rack->rc_tp)) {
5727 		union tcp_log_stackspecific log;
5728 		struct timeval tv;
5729 
5730 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5731 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5732 		log.u_bbr.flex1 = flex1;
5733 		log.u_bbr.flex2 = flex2;
5734 		log.u_bbr.flex3 = flex3;
5735 		log.u_bbr.flex4 = flex4;
5736 		log.u_bbr.flex5 = rack->r_ctl.current_policer_bucket;
5737 		log.u_bbr.flex6 = rack->r_ctl.policer_bucket_size;
5738 		log.u_bbr.flex7 = 0;
5739 		log.u_bbr.flex8 = flex8;
5740 		log.u_bbr.bw_inuse = rack->r_ctl.policer_bw;
5741 		log.u_bbr.applimited = rack->r_ctl.current_round;
5742 		log.u_bbr.epoch = rack->r_ctl.policer_max_seg;
5743 		log.u_bbr.delivered = (uint32_t)rack->r_ctl.bytes_acked_in_recovery;
5744 		log.u_bbr.cur_del_rate = rack->rc_tp->t_sndbytes;
5745 		log.u_bbr.delRate = rack->rc_tp->t_snd_rxt_bytes;
5746 		log.u_bbr.rttProp = rack->r_ctl.gp_bw;
5747 		log.u_bbr.bbr_state = rack->rc_policer_detected;
5748 		log.u_bbr.bbr_substate = 0;
5749 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
5750 		log.u_bbr.use_lt_bw = rack->policer_detect_on;
5751 		log.u_bbr.lt_epoch = 0;
5752 		log.u_bbr.pkts_out = 0;
5753 		tcp_log_event(rack->rc_tp, NULL, NULL, NULL, TCP_POLICER_DET, 0,
5754 			      0, &log, false, NULL, NULL, 0, &tv);
5755 	}
5756 
5757 }
5758 
5759 static void
policer_detection(struct tcpcb * tp,struct tcp_rack * rack,int post_recovery)5760 policer_detection(struct tcpcb *tp, struct tcp_rack *rack, int post_recovery)
5761 {
5762 	/*
5763 	 * Rack excess rxt accounting is turned on. If we
5764 	 * are above a threshold of rxt's in at least N
5765 	 * rounds, then back off the cwnd and ssthresh
5766 	 * to fit into the long-term b/w.
5767 	 */
5768 
5769 	uint32_t pkts, mid, med, alt_med, avg, segsiz, tot_retran_pkt_count = 0;
5770 	uint32_t cnt_of_mape_rxt = 0;
5771 	uint64_t snds, rxts, rxt_per, tim, del, del_bw;
5772 	int i;
5773 	struct timeval tv;
5774 
5775 
5776 	/*
5777 	 * First is there enough packets delivered during recovery to make
5778 	 * a determiniation of b/w?
5779 	 */
5780 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
5781 	if ((rack->rc_policer_detected == 0) &&
5782 	    (rack->r_ctl.policer_del_mss > 0) &&
5783 	    ((uint32_t)rack->r_ctl.policer_del_mss > ((rack->r_ctl.bytes_acked_in_recovery + segsiz - 1)/segsiz))) {
5784 		/*
5785 		 * Not enough data sent in recovery for initial detection. Once
5786 		 * we have deteced a policer we allow less than the threshold (polcer_del_mss)
5787 		 * amount of data in a recovery to let us fall through and double check
5788 		 * our policer settings and possibly expand or collapse the bucket size and
5789 		 * the polcier b/w.
5790 		 *
5791 		 * Once you are declared to be policed. this block of code cannot be
5792 		 * reached, instead blocks further down will re-check the policer detection
5793 		 * triggers and possibly reset the measurements if somehow we have let the
5794 		 * policer bucket size grow too large.
5795 		 */
5796 		if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
5797 			policer_detection_log(rack, rack->r_ctl.policer_del_mss,
5798 					      ((rack->r_ctl.bytes_acked_in_recovery + segsiz - 1)/segsiz),
5799 					      rack->r_ctl.bytes_acked_in_recovery, segsiz, 18);
5800 		}
5801 		return;
5802 	}
5803 	tcp_get_usecs(&tv);
5804 	tim = tcp_tv_to_lusectick(&tv) - rack->r_ctl.time_entered_recovery;
5805 	del = rack->r_ctl.bytes_acked_in_recovery;
5806 	if (tim > 0)
5807 		del_bw = (del * (uint64_t)1000000) / tim;
5808 	else
5809 		del_bw = 0;
5810 	/* B/W compensation? */
5811 
5812 	if (rack->r_ctl.pol_bw_comp && ((rack->r_ctl.policer_bw > 0) ||
5813 					(del_bw > 0))) {
5814 		/*
5815 		 * Sanity check now that the data is in. How long does it
5816 		 * take for us to pace out two of our policer_max_seg's?
5817 		 *
5818 		 * If it is longer than the RTT then we are set
5819 		 * too slow, maybe because of not enough data
5820 		 * sent during recovery.
5821 		 */
5822 		uint64_t lentime, res, srtt, max_delbw, alt_bw;
5823 
5824 		srtt = (uint64_t)rack_grab_rtt(tp, rack);
5825 		if ((tp->t_srtt > 0) && (srtt > tp->t_srtt))
5826 			srtt = tp->t_srtt;
5827 		lentime = rack->r_ctl.policer_max_seg * (uint64_t)HPTS_USEC_IN_SEC * 2;
5828 		if (del_bw > rack->r_ctl.policer_bw) {
5829 			max_delbw = del_bw;
5830 		} else {
5831 			max_delbw = rack->r_ctl.policer_bw;
5832 		}
5833 		res = lentime / max_delbw;
5834 		if ((srtt > 0) && (res > srtt)) {
5835 			/*
5836 			 * At this rate we can not get two policer_maxsegs
5837 			 * out before the ack arrives back.
5838 			 *
5839 			 * Lets at least get it raised up so that
5840 			 * we can be a bit faster than that if possible.
5841 			 */
5842 			lentime = (rack->r_ctl.policer_max_seg * 2);
5843 			tim = srtt;
5844 			alt_bw = (lentime * (uint64_t)HPTS_USEC_IN_SEC) / tim;
5845 			if (alt_bw > max_delbw) {
5846 				uint64_t cap_alt_bw;
5847 
5848 				cap_alt_bw = (max_delbw + (max_delbw * rack->r_ctl.pol_bw_comp));
5849 				if ((rack_pol_min_bw > 0) && (cap_alt_bw < rack_pol_min_bw)) {
5850 					/* We place a min on the cap which defaults to 1Mbps */
5851 					cap_alt_bw = rack_pol_min_bw;
5852 				}
5853 				if (alt_bw <= cap_alt_bw) {
5854 					/* It should be */
5855 					del_bw = alt_bw;
5856 					policer_detection_log(rack,
5857 							      (uint32_t)tim,
5858 							      rack->r_ctl.policer_max_seg,
5859 							      0,
5860 							      0,
5861 							      16);
5862 				} else {
5863 					/*
5864 					 * This is an odd case where likely the RTT is very very
5865 					 * low. And yet it is still being policed. We don't want
5866 					 * to get more than (rack_policing_do_bw_comp+1) x del-rate
5867 					 * where del-rate is what we got in recovery for either the
5868 					 * first Policer Detection(PD) or this PD we are on now.
5869 					 */
5870 					del_bw = cap_alt_bw;
5871 					policer_detection_log(rack,
5872 							      (uint32_t)tim,
5873 							      rack->r_ctl.policer_max_seg,
5874 							      (uint32_t)max_delbw,
5875 							      (rack->r_ctl.pol_bw_comp + 1),
5876 							      16);
5877 				}
5878 			}
5879 		}
5880 	}
5881 	snds = tp->t_sndbytes - rack->r_ctl.last_policer_sndbytes;
5882 	rxts = tp->t_snd_rxt_bytes - rack->r_ctl.last_policer_snd_rxt_bytes;
5883 	rxt_per = rack_get_rxt_per(snds,  rxts);
5884 	/* Figure up the average  and median */
5885 	for(i = 0; i < RETRAN_CNT_SIZE; i++) {
5886 		if (rack->r_ctl.rc_cnt_of_retran[i] > 0) {
5887 			tot_retran_pkt_count += (i + 1) * rack->r_ctl.rc_cnt_of_retran[i];
5888 			cnt_of_mape_rxt  += rack->r_ctl.rc_cnt_of_retran[i];
5889 		}
5890 	}
5891 	if (cnt_of_mape_rxt)
5892 		avg = (tot_retran_pkt_count * 10)/cnt_of_mape_rxt;
5893 	else
5894 		avg = 0;
5895 	alt_med = med = 0;
5896 	mid = tot_retran_pkt_count/2;
5897 	for(i = 0; i < RETRAN_CNT_SIZE; i++) {
5898 		pkts = (i + 1) * rack->r_ctl.rc_cnt_of_retran[i];
5899 		if (mid > pkts) {
5900 			mid -= pkts;
5901 			continue;
5902 		}
5903 		med = (i + 1);
5904 		break;
5905 	}
5906 	mid = cnt_of_mape_rxt / 2;
5907 	for(i = 0; i < RETRAN_CNT_SIZE; i++) {
5908 		if (mid > rack->r_ctl.rc_cnt_of_retran[i]) {
5909 			mid -= rack->r_ctl.rc_cnt_of_retran[i];
5910 			continue;
5911 		}
5912 		alt_med = (i + 1);
5913 		break;
5914 	}
5915 	if (rack->r_ctl.policer_alt_median) {
5916 		/* Swap the medians */
5917 		uint32_t swap;
5918 
5919 		swap = med;
5920 		med = alt_med;
5921 		alt_med = swap;
5922 	}
5923 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
5924 		union tcp_log_stackspecific log;
5925 		struct timeval tv;
5926 
5927 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5928 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5929 		log.u_bbr.flex1 = avg;
5930 		log.u_bbr.flex2 = med;
5931 		log.u_bbr.flex3 = (uint32_t)rxt_per;
5932 		log.u_bbr.flex4 = rack->r_ctl.policer_avg_threshold;
5933 		log.u_bbr.flex5 = rack->r_ctl.policer_med_threshold;
5934 		log.u_bbr.flex6 = rack->r_ctl.policer_rxt_threshold;
5935 		log.u_bbr.flex7 = rack->r_ctl.policer_alt_median;
5936 		log.u_bbr.flex8 = 1;
5937 		log.u_bbr.delivered = rack->r_ctl.policer_bucket_size;
5938 		log.u_bbr.applimited = rack->r_ctl.current_round;
5939 		log.u_bbr.epoch = rack->r_ctl.policer_max_seg;
5940 		log.u_bbr.bw_inuse = del_bw;
5941 		log.u_bbr.cur_del_rate = rxts;
5942 		log.u_bbr.delRate = snds;
5943 		log.u_bbr.rttProp = rack->r_ctl.gp_bw;
5944 		log.u_bbr.bbr_state = rack->rc_policer_detected;
5945 		log.u_bbr.bbr_substate = 0;
5946 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
5947 		log.u_bbr.use_lt_bw = rack->policer_detect_on;
5948 		log.u_bbr.lt_epoch = (uint32_t)tim;
5949 		log.u_bbr.pkts_out = rack->r_ctl.bytes_acked_in_recovery;
5950 		tcp_log_event(tp, NULL, NULL, NULL, TCP_POLICER_DET, 0,
5951 			      0, &log, false, NULL, NULL, 0, &tv);
5952 	}
5953 	if (med == RETRAN_CNT_SIZE) {
5954 		/*
5955 		 * If the median is the maximum, then what we
5956 		 * likely have here is a network breakage. Either that
5957 		 * or we are so unlucky that all of our traffic is being
5958 		 * dropped and having to be retransmitted the maximum times
5959 		 * and this just is not how a policer works.
5960 		 *
5961 		 * If it is truely a policer eventually we will come
5962 		 * through and it won't be the maximum.
5963 		 */
5964 		return;
5965 	}
5966 	/* Has enough rounds progressed for us to re-measure? */
5967 	if ((rxt_per >= (uint64_t)rack->r_ctl.policer_rxt_threshold) &&
5968 	    (avg >= rack->r_ctl.policer_avg_threshold) &&
5969 	    (med >= rack->r_ctl.policer_med_threshold)) {
5970 		/*
5971 		 * We hit all thresholds that indicate we are
5972 		 * being policed. Now we may be doing this from a rack timeout
5973 		 * which then means the rest of recovery will hopefully go
5974 		 * smoother as we pace. At the end of recovery we will
5975 		 * fall back in here and reset the values using the
5976 		 * results of the entire recovery episode (we could also
5977 		 * hit this as we exit recovery as well which means only
5978 		 * one time in here).
5979 		 *
5980 		 * This is done explicitly that if we hit the thresholds
5981 		 * again in a second recovery we overwrite the values. We do
5982 		 * that because over time, as we pace the policer_bucket_size may
5983 		 * continue to grow. This then provides more and more times when
5984 		 * we are not pacing to the policer rate. This lets us compensate
5985 		 * for when we hit a false positive and those flows continue to
5986 		 * increase. However if its a real policer we will then get over its
5987 		 * limit, over time, again and thus end up back here hitting the
5988 		 * thresholds again.
5989 		 *
5990 		 * The alternative to this is to instead whenever we pace due to
5991 		 * policing in rack_policed_sending we could add the amount len paced to the
5992 		 * idle_snd_una value (which decreases the amount in last_amount_before_rec
5993 		 * since that is always [th_ack - idle_snd_una]). This would then prevent
5994 		 * the polcier_bucket_size from growing in additional recovery episodes
5995 		 * Which would then mean false  postives would be pretty much stuck
5996 		 * after things got back to normal (assuming that what caused the
5997 		 * false positive was a small network outage).
5998 		 *
5999 		 */
6000 		tcp_trace_point(rack->rc_tp, TCP_TP_POLICER_DET);
6001 		if (rack->rc_policer_detected == 0) {
6002 			/*
6003 			 * Increment the stat that tells us we identified
6004 			 * a policer only once. Note that if we ever allow
6005 			 * the flag to be cleared (reverted) then we need
6006 			 * to adjust this to not do multi-counting.
6007 			 */
6008 			counter_u64_add(tcp_policer_detected, 1);
6009 		}
6010 		rack->r_ctl.last_policer_sndbytes = tp->t_sndbytes;
6011 		rack->r_ctl.last_policer_snd_rxt_bytes = tp->t_snd_rxt_bytes;
6012 		rack->r_ctl.policer_bw = del_bw;
6013 		rack->r_ctl.policer_max_seg = tcp_get_pacing_burst_size_w_divisor(rack->rc_tp,
6014 										  rack->r_ctl.policer_bw,
6015 										  min(ctf_fixed_maxseg(rack->rc_tp),
6016 										      rack->r_ctl.rc_pace_min_segs),
6017 										  0, NULL,
6018 										  NULL, rack->r_ctl.pace_len_divisor);
6019 		/* Now what about the policer bucket size */
6020 		rack->r_ctl.policer_bucket_size = rack->r_ctl.last_amount_before_rec;
6021 		if (rack->r_ctl.policer_bucket_size < rack->r_ctl.policer_max_seg) {
6022 			/* We must be able to send our max-seg or else chaos ensues */
6023 			rack->r_ctl.policer_bucket_size = rack->r_ctl.policer_max_seg * 2;
6024 		}
6025 		if (rack->rc_policer_detected == 0)
6026 			rack->r_ctl.current_policer_bucket = 0;
6027 		if (tcp_bblogging_on(rack->rc_tp)) {
6028 			union tcp_log_stackspecific log;
6029 			struct timeval tv;
6030 
6031 			memset(&log.u_bbr, 0, sizeof(log.u_bbr));
6032 			log.u_bbr.timeStamp = tcp_get_usecs(&tv);
6033 			log.u_bbr.flex1 = avg;
6034 			log.u_bbr.flex2 = med;
6035 			log.u_bbr.flex3 = rxt_per;
6036 			log.u_bbr.flex4 = rack->r_ctl.policer_avg_threshold;
6037 			log.u_bbr.flex5 = rack->r_ctl.policer_med_threshold;
6038 			log.u_bbr.flex6 = rack->r_ctl.policer_rxt_threshold;
6039 			log.u_bbr.flex7 = rack->r_ctl.policer_alt_median;
6040 			log.u_bbr.flex8 = 2;
6041 			log.u_bbr.applimited = rack->r_ctl.current_round;
6042 			log.u_bbr.bw_inuse = del_bw;
6043 			log.u_bbr.delivered = rack->r_ctl.policer_bucket_size;
6044 			log.u_bbr.cur_del_rate = rxts;
6045 			log.u_bbr.delRate = snds;
6046 			log.u_bbr.rttProp = rack->r_ctl.gp_bw;
6047 			log.u_bbr.bbr_state = rack->rc_policer_detected;
6048 			log.u_bbr.bbr_substate = 0;
6049 			log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
6050 			log.u_bbr.use_lt_bw = rack->policer_detect_on;
6051 			log.u_bbr.epoch = rack->r_ctl.policer_max_seg;
6052 			log.u_bbr.lt_epoch = (uint32_t)tim;
6053 			log.u_bbr.pkts_out = rack->r_ctl.bytes_acked_in_recovery;
6054 			tcp_log_event(tp, NULL, NULL, NULL, TCP_POLICER_DET, 0,
6055 				      0, &log, false, NULL, NULL, 0, &tv);
6056 			/*
6057 			 * Put out an added log, 19, for the sole purpose
6058 			 * of getting the txt/rxt so that we can benchmark
6059 			 * in read-bbrlog the ongoing rxt rate after our
6060 			 * policer invocation in the HYSTART announcments.
6061 			 */
6062 			memset(&log.u_bbr, 0, sizeof(log.u_bbr));
6063 			log.u_bbr.timeStamp = tcp_tv_to_usectick(&tv);
6064 			log.u_bbr.flex1 = alt_med;
6065 			log.u_bbr.flex8 = 19;
6066 			log.u_bbr.cur_del_rate = tp->t_sndbytes;
6067 			log.u_bbr.delRate = tp->t_snd_rxt_bytes;
6068 			tcp_log_event(tp, NULL, NULL, NULL, TCP_POLICER_DET, 0,
6069 				      0, &log, false, NULL, NULL, 0, &tv);
6070 		}
6071 		/* Turn off any fast output, thats ended */
6072 		rack->r_fast_output = 0;
6073 		/* Mark the time for credits */
6074 		rack->r_ctl.last_sendtime = tcp_get_u64_usecs(NULL);
6075 		if (rack->r_rr_config < 2) {
6076 			/*
6077 			 * We need to be stricter on the RR config so
6078 			 * the pacing has priority.
6079 			 */
6080 			rack->r_rr_config = 2;
6081 		}
6082 		policer_detection_log(rack,
6083 				      rack->r_ctl.idle_snd_una,
6084 				      rack->r_ctl.ack_for_idle,
6085 				      0,
6086 				      (uint32_t)tim,
6087 				      14);
6088 		rack->rc_policer_detected = 1;
6089 	} else if ((rack->rc_policer_detected == 1) &&
6090 		   (post_recovery == 1)) {
6091 		/*
6092 		 * If we are exiting recovery and have already detected
6093 		 * we need to possibly update the values.
6094 		 *
6095 		 * First: Update the idle -> recovery sent value.
6096 		 */
6097 		uint32_t srtt;
6098 
6099 		if (rack->r_ctl.last_amount_before_rec > rack->r_ctl.policer_bucket_size) {
6100 			rack->r_ctl.policer_bucket_size = rack->r_ctl.last_amount_before_rec;
6101 		}
6102 		srtt = (uint64_t)rack_grab_rtt(tp, rack);
6103 		if ((tp->t_srtt > 0) && (srtt > tp->t_srtt))
6104 			srtt = tp->t_srtt;
6105 		if ((srtt != 0) &&
6106 		    (tim < (uint64_t)srtt)) {
6107 			/*
6108 			 * Not long enough.
6109 			 */
6110 			if (rack_verbose_logging)
6111 				policer_detection_log(rack,
6112 						      (uint32_t)tim,
6113 						      0,
6114 						      0,
6115 						      0,
6116 						      15);
6117 			return;
6118 		}
6119 		/*
6120 		 * Finally update the b/w if its grown.
6121 		 */
6122 		if (del_bw > rack->r_ctl.policer_bw) {
6123 			rack->r_ctl.policer_bw = del_bw;
6124 			rack->r_ctl.policer_max_seg = tcp_get_pacing_burst_size_w_divisor(rack->rc_tp,
6125 											  rack->r_ctl.policer_bw,
6126 											  min(ctf_fixed_maxseg(rack->rc_tp),
6127 											      rack->r_ctl.rc_pace_min_segs),
6128 											  0, NULL,
6129 											  NULL, rack->r_ctl.pace_len_divisor);
6130 			if (rack->r_ctl.policer_bucket_size < rack->r_ctl.policer_max_seg) {
6131 				/* We must be able to send our max-seg or else chaos ensues */
6132 				rack->r_ctl.policer_bucket_size = rack->r_ctl.policer_max_seg * 2;
6133 			}
6134 		}
6135 		policer_detection_log(rack,
6136 				      rack->r_ctl.idle_snd_una,
6137 				      rack->r_ctl.ack_for_idle,
6138 				      0,
6139 				      (uint32_t)tim,
6140 				      3);
6141 	}
6142 }
6143 
6144 static void
rack_exit_recovery(struct tcpcb * tp,struct tcp_rack * rack,int how)6145 rack_exit_recovery(struct tcpcb *tp, struct tcp_rack *rack, int how)
6146 {
6147 	/* now check with the policer if on */
6148 	if (rack->policer_detect_on == 1) {
6149 		policer_detection(tp, rack, 1);
6150 	}
6151 	/*
6152 	 * Now exit recovery, note we must do the idle set after the policer_detection
6153 	 * to get the amount acked prior to recovery correct.
6154 	 */
6155 	rack->r_ctl.idle_snd_una = tp->snd_una;
6156 	EXIT_RECOVERY(tp->t_flags);
6157 }
6158 
6159 static void
rack_post_recovery(struct tcpcb * tp,uint32_t th_ack)6160 rack_post_recovery(struct tcpcb *tp, uint32_t th_ack)
6161 {
6162 	struct tcp_rack *rack;
6163 	uint32_t orig_cwnd;
6164 
6165 	orig_cwnd = tp->snd_cwnd;
6166 	INP_WLOCK_ASSERT(tptoinpcb(tp));
6167 	rack = (struct tcp_rack *)tp->t_fb_ptr;
6168 	/* only alert CC if we alerted when we entered */
6169 	if (CC_ALGO(tp)->post_recovery != NULL) {
6170 		tp->t_ccv.curack = th_ack;
6171 		CC_ALGO(tp)->post_recovery(&tp->t_ccv);
6172 		if (tp->snd_cwnd < tp->snd_ssthresh) {
6173 			/*
6174 			 * Rack has burst control and pacing
6175 			 * so lets not set this any lower than
6176 			 * snd_ssthresh per RFC-6582 (option 2).
6177 			 */
6178 			tp->snd_cwnd = tp->snd_ssthresh;
6179 		}
6180 	}
6181 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
6182 		union tcp_log_stackspecific log;
6183 		struct timeval tv;
6184 
6185 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
6186 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
6187 		log.u_bbr.flex1 = th_ack;
6188 		log.u_bbr.flex2 = tp->t_ccv.flags;
6189 		log.u_bbr.flex3 = tp->t_ccv.bytes_this_ack;
6190 		log.u_bbr.flex4 = tp->t_ccv.nsegs;
6191 		log.u_bbr.flex5 = V_tcp_abc_l_var;
6192 		log.u_bbr.flex6 = orig_cwnd;
6193 		log.u_bbr.flex7 = V_tcp_do_newsack;
6194 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
6195 		log.u_bbr.flex8 = 2;
6196 		tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
6197 			       0, &log, false, NULL, __func__, __LINE__, &tv);
6198 	}
6199 	if ((rack->rack_no_prr == 0) &&
6200 	    (rack->no_prr_addback == 0) &&
6201 	    (rack->r_ctl.rc_prr_sndcnt > 0)) {
6202 		/*
6203 		 * Suck the next prr cnt back into cwnd, but
6204 		 * only do that if we are not application limited.
6205 		 */
6206 		if (ctf_outstanding(tp) <= sbavail(&tptosocket(tp)->so_snd)) {
6207 			/*
6208 			 * We are allowed to add back to the cwnd the amount we did
6209 			 * not get out if:
6210 			 * a) no_prr_addback is off.
6211 			 * b) we are not app limited
6212 			 * c) we are doing prr
6213 			 * <and>
6214 			 * d) it is bounded by rack_prr_addbackmax (if addback is 0, then none).
6215 			 */
6216 			tp->snd_cwnd += min((ctf_fixed_maxseg(tp) * rack_prr_addbackmax),
6217 					    rack->r_ctl.rc_prr_sndcnt);
6218 		}
6219 		rack->r_ctl.rc_prr_sndcnt = 0;
6220 		rack_log_to_prr(rack, 1, 0, __LINE__);
6221 	}
6222 	rack_log_to_prr(rack, 14, orig_cwnd, __LINE__);
6223 	tp->snd_recover = tp->snd_una;
6224 	if (rack->r_ctl.dsack_persist) {
6225 		rack->r_ctl.dsack_persist--;
6226 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
6227 			rack->r_ctl.num_dsack = 0;
6228 		}
6229 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
6230 	}
6231 	if (rack->rto_from_rec == 1) {
6232 		rack->rto_from_rec = 0;
6233 		if (rack->r_ctl.rto_ssthresh > tp->snd_ssthresh)
6234 			tp->snd_ssthresh = rack->r_ctl.rto_ssthresh;
6235 	}
6236 	rack_exit_recovery(tp, rack, 1);
6237 }
6238 
6239 static void
rack_cong_signal(struct tcpcb * tp,uint32_t type,uint32_t ack,int line)6240 rack_cong_signal(struct tcpcb *tp, uint32_t type, uint32_t ack, int line)
6241 {
6242 	struct tcp_rack *rack;
6243 	uint32_t ssthresh_enter, cwnd_enter, in_rec_at_entry, orig_cwnd;
6244 
6245 	INP_WLOCK_ASSERT(tptoinpcb(tp));
6246 #ifdef STATS
6247 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_CSIG, type);
6248 #endif
6249 	if (IN_RECOVERY(tp->t_flags) == 0) {
6250 		in_rec_at_entry = 0;
6251 		ssthresh_enter = tp->snd_ssthresh;
6252 		cwnd_enter = tp->snd_cwnd;
6253 	} else
6254 		in_rec_at_entry = 1;
6255 	rack = (struct tcp_rack *)tp->t_fb_ptr;
6256 	switch (type) {
6257 	case CC_NDUPACK:
6258 		tp->t_flags &= ~TF_WASFRECOVERY;
6259 		tp->t_flags &= ~TF_WASCRECOVERY;
6260 		if (!IN_FASTRECOVERY(tp->t_flags)) {
6261 			struct rack_sendmap *rsm;
6262 			struct timeval tv;
6263 			uint32_t segsiz;
6264 
6265 			/* Check if this is the end of the initial Start-up i.e. initial slow-start */
6266 			if (rack->rc_initial_ss_comp == 0) {
6267 				/* Yep it is the end of the initial slowstart */
6268 				rack->rc_initial_ss_comp = 1;
6269 			}
6270 			microuptime(&tv);
6271 			rack->r_ctl.time_entered_recovery = tcp_tv_to_lusectick(&tv);
6272 			if (SEQ_GEQ(ack, tp->snd_una)) {
6273 				/*
6274 				 * The ack is above snd_una. Lets see
6275 				 * if we can establish a postive distance from
6276 				 * our idle mark.
6277 				 */
6278 				rack->r_ctl.ack_for_idle = ack;
6279 				if (SEQ_GT(ack, rack->r_ctl.idle_snd_una)) {
6280 					rack->r_ctl.last_amount_before_rec = ack - rack->r_ctl.idle_snd_una;
6281 				} else {
6282 					/* No data thru yet */
6283 					rack->r_ctl.last_amount_before_rec = 0;
6284 				}
6285 			} else if (SEQ_GT(tp->snd_una, rack->r_ctl.idle_snd_una)) {
6286 				/*
6287 				 * The ack is out of order and behind the snd_una. It may
6288 				 * have contained SACK information which we processed else
6289 				 * we would have rejected it.
6290 				 */
6291 				rack->r_ctl.ack_for_idle = tp->snd_una;
6292 				rack->r_ctl.last_amount_before_rec = tp->snd_una - rack->r_ctl.idle_snd_una;
6293 			} else {
6294 				rack->r_ctl.ack_for_idle = ack;
6295 				rack->r_ctl.last_amount_before_rec = 0;
6296 			}
6297 			if (rack->rc_policer_detected) {
6298 				/*
6299 				 * If we are being policed and we have a loss, it
6300 				 * means our bucket is now empty. This can happen
6301 				 * where some other flow on the same host sends
6302 				 * that this connection is not aware of.
6303 				 */
6304 				rack->r_ctl.current_policer_bucket = 0;
6305 				if (rack_verbose_logging)
6306 					policer_detection_log(rack, rack->r_ctl.last_amount_before_rec, 0, 0, 0, 4);
6307 				if (rack->r_ctl.last_amount_before_rec > rack->r_ctl.policer_bucket_size) {
6308 					rack->r_ctl.policer_bucket_size = rack->r_ctl.last_amount_before_rec;
6309 				}
6310 			}
6311 			memset(rack->r_ctl.rc_cnt_of_retran, 0, sizeof(rack->r_ctl.rc_cnt_of_retran));
6312 			segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
6313 			TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
6314 				/*
6315 				 * Go through the outstanding and re-peg
6316 				 * any that should have been left in the
6317 				 * retransmit list (on a double recovery).
6318 				 */
6319 				if (rsm->r_act_rxt_cnt > 0) {
6320 					rack_peg_rxt(rack, rsm, segsiz);
6321 				}
6322 			}
6323 			rack->r_ctl.bytes_acked_in_recovery = 0;
6324 			rack->r_ctl.rc_prr_delivered = 0;
6325 			rack->r_ctl.rc_prr_out = 0;
6326 			rack->r_fast_output = 0;
6327 			if (rack->rack_no_prr == 0) {
6328 				rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
6329 				rack_log_to_prr(rack, 2, in_rec_at_entry, line);
6330 			}
6331 			rack->r_ctl.rc_prr_recovery_fs = tp->snd_max - tp->snd_una;
6332 			tp->snd_recover = tp->snd_max;
6333 			if (tp->t_flags2 & TF2_ECN_PERMIT)
6334 				tp->t_flags2 |= TF2_ECN_SND_CWR;
6335 		}
6336 		break;
6337 	case CC_ECN:
6338 		if (!IN_CONGRECOVERY(tp->t_flags) ||
6339 		    /*
6340 		     * Allow ECN reaction on ACK to CWR, if
6341 		     * that data segment was also CE marked.
6342 		     */
6343 		    SEQ_GEQ(ack, tp->snd_recover)) {
6344 			EXIT_CONGRECOVERY(tp->t_flags);
6345 			KMOD_TCPSTAT_INC(tcps_ecn_rcwnd);
6346 			rack->r_fast_output = 0;
6347 			tp->snd_recover = tp->snd_max + 1;
6348 			if (tp->t_flags2 & TF2_ECN_PERMIT)
6349 				tp->t_flags2 |= TF2_ECN_SND_CWR;
6350 		}
6351 		break;
6352 	case CC_RTO:
6353 		tp->t_dupacks = 0;
6354 		tp->t_bytes_acked = 0;
6355 		rack->r_fast_output = 0;
6356 		if (IN_RECOVERY(tp->t_flags))
6357 			rack_exit_recovery(tp, rack, 2);
6358 		rack->r_ctl.bytes_acked_in_recovery = 0;
6359 		rack->r_ctl.time_entered_recovery = 0;
6360 		orig_cwnd = tp->snd_cwnd;
6361 		rack_log_to_prr(rack, 16, orig_cwnd, line);
6362 		if (CC_ALGO(tp)->cong_signal == NULL) {
6363 			/* TSNH */
6364 			tp->snd_ssthresh = max(2,
6365 			    min(tp->snd_wnd, rack->r_ctl.cwnd_to_use) / 2 /
6366 			    ctf_fixed_maxseg(tp)) * ctf_fixed_maxseg(tp);
6367 			tp->snd_cwnd = ctf_fixed_maxseg(tp);
6368 		}
6369 		if (tp->t_flags2 & TF2_ECN_PERMIT)
6370 			tp->t_flags2 |= TF2_ECN_SND_CWR;
6371 		break;
6372 	case CC_RTO_ERR:
6373 		KMOD_TCPSTAT_INC(tcps_sndrexmitbad);
6374 		/* RTO was unnecessary, so reset everything. */
6375 		tp->snd_cwnd = tp->snd_cwnd_prev;
6376 		tp->snd_ssthresh = tp->snd_ssthresh_prev;
6377 		tp->snd_recover = tp->snd_recover_prev;
6378 		if (tp->t_flags & TF_WASFRECOVERY) {
6379 			ENTER_FASTRECOVERY(tp->t_flags);
6380 			tp->t_flags &= ~TF_WASFRECOVERY;
6381 		}
6382 		if (tp->t_flags & TF_WASCRECOVERY) {
6383 			ENTER_CONGRECOVERY(tp->t_flags);
6384 			tp->t_flags &= ~TF_WASCRECOVERY;
6385 		}
6386 		tp->snd_nxt = tp->snd_max;
6387 		tp->t_badrxtwin = 0;
6388 		break;
6389 	}
6390 	if ((CC_ALGO(tp)->cong_signal != NULL)  &&
6391 	    (type != CC_RTO)){
6392 		tp->t_ccv.curack = ack;
6393 		CC_ALGO(tp)->cong_signal(&tp->t_ccv, type);
6394 	}
6395 	if ((in_rec_at_entry == 0) && IN_RECOVERY(tp->t_flags)) {
6396 		rack_log_to_prr(rack, 15, cwnd_enter, line);
6397 		rack->r_ctl.dsack_byte_cnt = 0;
6398 		rack->r_ctl.retran_during_recovery = 0;
6399 		rack->r_ctl.rc_cwnd_at_erec = cwnd_enter;
6400 		rack->r_ctl.rc_ssthresh_at_erec = ssthresh_enter;
6401 		rack->r_ent_rec_ns = 1;
6402 	}
6403 }
6404 
6405 static inline void
rack_cc_after_idle(struct tcp_rack * rack,struct tcpcb * tp)6406 rack_cc_after_idle(struct tcp_rack *rack, struct tcpcb *tp)
6407 {
6408 	uint32_t i_cwnd;
6409 
6410 	INP_WLOCK_ASSERT(tptoinpcb(tp));
6411 
6412 	if (CC_ALGO(tp)->after_idle != NULL)
6413 		CC_ALGO(tp)->after_idle(&tp->t_ccv);
6414 
6415 	if (tp->snd_cwnd == 1)
6416 		i_cwnd = tp->t_maxseg;		/* SYN(-ACK) lost */
6417 	else
6418 		i_cwnd = rc_init_window(rack);
6419 
6420 	/*
6421 	 * Being idle is no different than the initial window. If the cc
6422 	 * clamps it down below the initial window raise it to the initial
6423 	 * window.
6424 	 */
6425 	if (tp->snd_cwnd < i_cwnd) {
6426 		tp->snd_cwnd = i_cwnd;
6427 	}
6428 }
6429 
6430 /*
6431  * Indicate whether this ack should be delayed.  We can delay the ack if
6432  * following conditions are met:
6433  *	- There is no delayed ack timer in progress.
6434  *	- Our last ack wasn't a 0-sized window. We never want to delay
6435  *	  the ack that opens up a 0-sized window.
6436  *	- LRO wasn't used for this segment. We make sure by checking that the
6437  *	  segment size is not larger than the MSS.
6438  *	- Delayed acks are enabled or this is a half-synchronized T/TCP
6439  *	  connection.
6440  */
6441 #define DELAY_ACK(tp, tlen)			 \
6442 	(((tp->t_flags & TF_RXWIN0SENT) == 0) && \
6443 	((tp->t_flags & TF_DELACK) == 0) &&	 \
6444 	(tlen <= tp->t_maxseg) &&		 \
6445 	(tp->t_delayed_ack || (tp->t_flags & TF_NEEDSYN)))
6446 
6447 static struct rack_sendmap *
rack_find_lowest_rsm(struct tcp_rack * rack)6448 rack_find_lowest_rsm(struct tcp_rack *rack)
6449 {
6450 	struct rack_sendmap *rsm;
6451 
6452 	/*
6453 	 * Walk the time-order transmitted list looking for an rsm that is
6454 	 * not acked. This will be the one that was sent the longest time
6455 	 * ago that is still outstanding.
6456 	 */
6457 	TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
6458 		if (rsm->r_flags & RACK_ACKED) {
6459 			continue;
6460 		}
6461 		goto finish;
6462 	}
6463 finish:
6464 	return (rsm);
6465 }
6466 
6467 static struct rack_sendmap *
rack_find_high_nonack(struct tcp_rack * rack,struct rack_sendmap * rsm)6468 rack_find_high_nonack(struct tcp_rack *rack, struct rack_sendmap *rsm)
6469 {
6470 	struct rack_sendmap *prsm;
6471 
6472 	/*
6473 	 * Walk the sequence order list backward until we hit and arrive at
6474 	 * the highest seq not acked. In theory when this is called it
6475 	 * should be the last segment (which it was not).
6476 	 */
6477 	prsm = rsm;
6478 
6479 	TQHASH_FOREACH_REVERSE_FROM(prsm, rack->r_ctl.tqh) {
6480 		if (prsm->r_flags & (RACK_ACKED | RACK_HAS_FIN)) {
6481 			continue;
6482 		}
6483 		return (prsm);
6484 	}
6485 	return (NULL);
6486 }
6487 
6488 static uint32_t
rack_calc_thresh_rack(struct tcp_rack * rack,uint32_t srtt,uint32_t cts,int line,int log_allowed)6489 rack_calc_thresh_rack(struct tcp_rack *rack, uint32_t srtt, uint32_t cts, int line, int log_allowed)
6490 {
6491 	int32_t lro;
6492 	uint32_t thresh;
6493 
6494 	/*
6495 	 * lro is the flag we use to determine if we have seen reordering.
6496 	 * If it gets set we have seen reordering. The reorder logic either
6497 	 * works in one of two ways:
6498 	 *
6499 	 * If reorder-fade is configured, then we track the last time we saw
6500 	 * re-ordering occur. If we reach the point where enough time as
6501 	 * passed we no longer consider reordering has occuring.
6502 	 *
6503 	 * Or if reorder-face is 0, then once we see reordering we consider
6504 	 * the connection to alway be subject to reordering and just set lro
6505 	 * to 1.
6506 	 *
6507 	 * In the end if lro is non-zero we add the extra time for
6508 	 * reordering in.
6509 	 */
6510 	if (srtt == 0)
6511 		srtt = 1;
6512 	if (rack->r_ctl.rc_reorder_ts) {
6513 		if (rack->r_ctl.rc_reorder_fade) {
6514 			if (SEQ_GEQ(cts, rack->r_ctl.rc_reorder_ts)) {
6515 				lro = cts - rack->r_ctl.rc_reorder_ts;
6516 				if (lro == 0) {
6517 					/*
6518 					 * No time as passed since the last
6519 					 * reorder, mark it as reordering.
6520 					 */
6521 					lro = 1;
6522 				}
6523 			} else {
6524 				/* Negative time? */
6525 				lro = 0;
6526 			}
6527 			if (lro > rack->r_ctl.rc_reorder_fade) {
6528 				/* Turn off reordering seen too */
6529 				rack->r_ctl.rc_reorder_ts = 0;
6530 				lro = 0;
6531 			}
6532 		} else {
6533 			/* Reodering does not fade */
6534 			lro = 1;
6535 		}
6536 	} else {
6537 		lro = 0;
6538 	}
6539 	if (rack->rc_rack_tmr_std_based == 0) {
6540 		thresh = srtt + rack->r_ctl.rc_pkt_delay;
6541 	} else {
6542 		/* Standards based pkt-delay is 1/4 srtt */
6543 		thresh = srtt +  (srtt >> 2);
6544 	}
6545 	if (lro && (rack->rc_rack_tmr_std_based == 0)) {
6546 		/* It must be set, if not you get 1/4 rtt */
6547 		if (rack->r_ctl.rc_reorder_shift)
6548 			thresh += (srtt >> rack->r_ctl.rc_reorder_shift);
6549 		else
6550 			thresh += (srtt >> 2);
6551 	}
6552 	if (rack->rc_rack_use_dsack &&
6553 	    lro &&
6554 	    (rack->r_ctl.num_dsack > 0)) {
6555 		/*
6556 		 * We only increase the reordering window if we
6557 		 * have seen reordering <and> we have a DSACK count.
6558 		 */
6559 		thresh += rack->r_ctl.num_dsack * (srtt >> 2);
6560 		if (log_allowed)
6561 			rack_log_dsack_event(rack, 4, line, srtt, thresh);
6562 	}
6563 	/* SRTT * 2 is the ceiling */
6564 	if (thresh > (srtt * 2)) {
6565 		thresh = srtt * 2;
6566 	}
6567 	/* And we don't want it above the RTO max either */
6568 	if (thresh > rack_rto_max) {
6569 		thresh = rack_rto_max;
6570 	}
6571 	if (log_allowed)
6572 		rack_log_dsack_event(rack, 6, line,  srtt, thresh);
6573 	return (thresh);
6574 }
6575 
6576 static uint32_t
rack_calc_thresh_tlp(struct tcpcb * tp,struct tcp_rack * rack,struct rack_sendmap * rsm,uint32_t srtt)6577 rack_calc_thresh_tlp(struct tcpcb *tp, struct tcp_rack *rack,
6578 		     struct rack_sendmap *rsm, uint32_t srtt)
6579 {
6580 	struct rack_sendmap *prsm;
6581 	uint32_t thresh, len;
6582 	int segsiz;
6583 
6584 	if (srtt == 0)
6585 		srtt = 1;
6586 	if (rack->r_ctl.rc_tlp_threshold)
6587 		thresh = srtt + (srtt / rack->r_ctl.rc_tlp_threshold);
6588 	else
6589 		thresh = (srtt * 2);
6590 
6591 	/* Get the previous sent packet, if any */
6592 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
6593 	len = rsm->r_end - rsm->r_start;
6594 	if (rack->rack_tlp_threshold_use == TLP_USE_ID) {
6595 		/* Exactly like the ID */
6596 		if (((tp->snd_max - tp->snd_una) - rack->r_ctl.rc_sacked + rack->r_ctl.rc_holes_rxt) <= segsiz) {
6597 			uint32_t alt_thresh;
6598 			/*
6599 			 * Compensate for delayed-ack with the d-ack time.
6600 			 */
6601 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
6602 			if (alt_thresh > thresh)
6603 				thresh = alt_thresh;
6604 		}
6605 	} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_ONE) {
6606 		/* 2.1 behavior */
6607 		prsm = TAILQ_PREV(rsm, rack_head, r_tnext);
6608 		if (prsm && (len <= segsiz)) {
6609 			/*
6610 			 * Two packets outstanding, thresh should be (2*srtt) +
6611 			 * possible inter-packet delay (if any).
6612 			 */
6613 			uint32_t inter_gap = 0;
6614 			int idx, nidx;
6615 
6616 			idx = rsm->r_rtr_cnt - 1;
6617 			nidx = prsm->r_rtr_cnt - 1;
6618 			if (rsm->r_tim_lastsent[nidx] >= prsm->r_tim_lastsent[idx]) {
6619 				/* Yes it was sent later (or at the same time) */
6620 				inter_gap = rsm->r_tim_lastsent[idx] - prsm->r_tim_lastsent[nidx];
6621 			}
6622 			thresh += inter_gap;
6623 		} else if (len <= segsiz) {
6624 			/*
6625 			 * Possibly compensate for delayed-ack.
6626 			 */
6627 			uint32_t alt_thresh;
6628 
6629 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
6630 			if (alt_thresh > thresh)
6631 				thresh = alt_thresh;
6632 		}
6633 	} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_TWO) {
6634 		/* 2.2 behavior */
6635 		if (len <= segsiz) {
6636 			uint32_t alt_thresh;
6637 			/*
6638 			 * Compensate for delayed-ack with the d-ack time.
6639 			 */
6640 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
6641 			if (alt_thresh > thresh)
6642 				thresh = alt_thresh;
6643 		}
6644 	}
6645 	/* Not above an RTO */
6646 	if (thresh > tp->t_rxtcur) {
6647 		thresh = tp->t_rxtcur;
6648 	}
6649 	/* Not above a RTO max */
6650 	if (thresh > rack_rto_max) {
6651 		thresh = rack_rto_max;
6652 	}
6653 	/* Apply user supplied min TLP */
6654 	if (thresh < rack_tlp_min) {
6655 		thresh = rack_tlp_min;
6656 	}
6657 	return (thresh);
6658 }
6659 
6660 static uint32_t
rack_grab_rtt(struct tcpcb * tp,struct tcp_rack * rack)6661 rack_grab_rtt(struct tcpcb *tp, struct tcp_rack *rack)
6662 {
6663 	/*
6664 	 * We want the rack_rtt which is the
6665 	 * last rtt we measured. However if that
6666 	 * does not exist we fallback to the srtt (which
6667 	 * we probably will never do) and then as a last
6668 	 * resort we use RACK_INITIAL_RTO if no srtt is
6669 	 * yet set.
6670 	 */
6671 	if (rack->rc_rack_rtt)
6672 		return (rack->rc_rack_rtt);
6673 	else if (tp->t_srtt == 0)
6674 		return (RACK_INITIAL_RTO);
6675 	return (tp->t_srtt);
6676 }
6677 
6678 static struct rack_sendmap *
rack_check_recovery_mode(struct tcpcb * tp,uint32_t tsused)6679 rack_check_recovery_mode(struct tcpcb *tp, uint32_t tsused)
6680 {
6681 	/*
6682 	 * Check to see that we don't need to fall into recovery. We will
6683 	 * need to do so if our oldest transmit is past the time we should
6684 	 * have had an ack.
6685 	 */
6686 	struct tcp_rack *rack;
6687 	struct rack_sendmap *rsm;
6688 	int32_t idx;
6689 	uint32_t srtt, thresh;
6690 
6691 	rack = (struct tcp_rack *)tp->t_fb_ptr;
6692 	if (tqhash_empty(rack->r_ctl.tqh)) {
6693 		return (NULL);
6694 	}
6695 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
6696 	if (rsm == NULL)
6697 		return (NULL);
6698 
6699 
6700 	if (rsm->r_flags & RACK_ACKED) {
6701 		rsm = rack_find_lowest_rsm(rack);
6702 		if (rsm == NULL)
6703 			return (NULL);
6704 	}
6705 	idx = rsm->r_rtr_cnt - 1;
6706 	srtt = rack_grab_rtt(tp, rack);
6707 	thresh = rack_calc_thresh_rack(rack, srtt, tsused, __LINE__, 1);
6708 	if (TSTMP_LT(tsused, ((uint32_t)rsm->r_tim_lastsent[idx]))) {
6709 		return (NULL);
6710 	}
6711 	if ((tsused - ((uint32_t)rsm->r_tim_lastsent[idx])) < thresh) {
6712 		return (NULL);
6713 	}
6714 	/* Ok if we reach here we are over-due and this guy can be sent */
6715 	rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
6716 	return (rsm);
6717 }
6718 
6719 static uint32_t
rack_get_persists_timer_val(struct tcpcb * tp,struct tcp_rack * rack)6720 rack_get_persists_timer_val(struct tcpcb *tp, struct tcp_rack *rack)
6721 {
6722 	int32_t t;
6723 	int32_t tt;
6724 	uint32_t ret_val;
6725 
6726 	t = (tp->t_srtt + (tp->t_rttvar << 2));
6727 	RACK_TCPT_RANGESET(tt, t * tcp_backoff[tp->t_rxtshift],
6728  	    rack_persist_min, rack_persist_max, rack->r_ctl.timer_slop);
6729 	rack->r_ctl.rc_hpts_flags |= PACE_TMR_PERSIT;
6730 	ret_val = (uint32_t)tt;
6731 	return (ret_val);
6732 }
6733 
6734 static uint32_t
rack_timer_start(struct tcpcb * tp,struct tcp_rack * rack,uint32_t cts,int sup_rack)6735 rack_timer_start(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int sup_rack)
6736 {
6737 	/*
6738 	 * Start the FR timer, we do this based on getting the first one in
6739 	 * the rc_tmap. Note that if its NULL we must stop the timer. in all
6740 	 * events we need to stop the running timer (if its running) before
6741 	 * starting the new one.
6742 	 */
6743 	uint32_t thresh, exp, to, srtt, time_since_sent, tstmp_touse;
6744 	uint32_t srtt_cur;
6745 	int32_t idx;
6746 	int32_t is_tlp_timer = 0;
6747 	struct rack_sendmap *rsm;
6748 
6749 	if (rack->t_timers_stopped) {
6750 		/* All timers have been stopped none are to run */
6751 		return (0);
6752 	}
6753 	if (rack->rc_in_persist) {
6754 		/* We can't start any timer in persists */
6755 		return (rack_get_persists_timer_val(tp, rack));
6756 	}
6757 	rack->rc_on_min_to = 0;
6758 	if ((tp->t_state < TCPS_ESTABLISHED) ||
6759 	    ((tp->t_flags & TF_SACK_PERMIT) == 0)) {
6760 		goto activate_rxt;
6761 	}
6762 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
6763 	if ((rsm == NULL) || sup_rack) {
6764 		/* Nothing on the send map or no rack */
6765 activate_rxt:
6766 		time_since_sent = 0;
6767 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
6768 		if (rsm) {
6769 			/*
6770 			 * Should we discount the RTX timer any?
6771 			 *
6772 			 * We want to discount it the smallest amount.
6773 			 * If a timer (Rack/TLP or RXT) has gone off more
6774 			 * recently thats the discount we want to use (now - timer time).
6775 			 * If the retransmit of the oldest packet was more recent then
6776 			 * we want to use that (now - oldest-packet-last_transmit_time).
6777 			 *
6778 			 */
6779 			idx = rsm->r_rtr_cnt - 1;
6780 			if (TSTMP_GEQ(rack->r_ctl.rc_tlp_rxt_last_time, ((uint32_t)rsm->r_tim_lastsent[idx])))
6781 				tstmp_touse = (uint32_t)rack->r_ctl.rc_tlp_rxt_last_time;
6782 			else
6783 				tstmp_touse = (uint32_t)rsm->r_tim_lastsent[idx];
6784 			if (TSTMP_GT(cts, tstmp_touse))
6785 			    time_since_sent = cts - tstmp_touse;
6786 		}
6787 		if (SEQ_LT(tp->snd_una, tp->snd_max) ||
6788 		    sbavail(&tptosocket(tp)->so_snd)) {
6789 			rack->r_ctl.rc_hpts_flags |= PACE_TMR_RXT;
6790 			to = tp->t_rxtcur;
6791 			if (to > time_since_sent)
6792 				to -= time_since_sent;
6793 			else
6794 				to = rack->r_ctl.rc_min_to;
6795 			if (to == 0)
6796 				to = 1;
6797 			/* Special case for KEEPINIT */
6798 			if ((TCPS_HAVEESTABLISHED(tp->t_state) == 0) &&
6799 			    (TP_KEEPINIT(tp) != 0) &&
6800 			    rsm) {
6801 				/*
6802 				 * We have to put a ceiling on the rxt timer
6803 				 * of the keep-init timeout.
6804 				 */
6805 				uint32_t max_time, red;
6806 
6807 				max_time = TICKS_2_USEC(TP_KEEPINIT(tp));
6808 				if (TSTMP_GT(cts, (uint32_t)rsm->r_tim_lastsent[0])) {
6809 					red = (cts - (uint32_t)rsm->r_tim_lastsent[0]);
6810 					if (red < max_time)
6811 						max_time -= red;
6812 					else
6813 						max_time = 1;
6814 				}
6815 				/* Reduce timeout to the keep value if needed */
6816 				if (max_time < to)
6817 					to = max_time;
6818 			}
6819 			return (to);
6820 		}
6821 		return (0);
6822 	}
6823 	if (rsm->r_flags & RACK_ACKED) {
6824 		rsm = rack_find_lowest_rsm(rack);
6825 		if (rsm == NULL) {
6826 			/* No lowest? */
6827 			goto activate_rxt;
6828 		}
6829 	}
6830 	/* Convert from ms to usecs */
6831 	if ((rsm->r_flags & RACK_SACK_PASSED) ||
6832 	    (rsm->r_flags & RACK_RWND_COLLAPSED) ||
6833 	    (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
6834 		if ((tp->t_flags & TF_SENTFIN) &&
6835 		    ((tp->snd_max - tp->snd_una) == 1) &&
6836 		    (rsm->r_flags & RACK_HAS_FIN)) {
6837 			/*
6838 			 * We don't start a rack timer if all we have is a
6839 			 * FIN outstanding.
6840 			 */
6841 			goto activate_rxt;
6842 		}
6843 		if ((rack->use_rack_rr == 0) &&
6844 		    (IN_FASTRECOVERY(tp->t_flags)) &&
6845 		    (rack->rack_no_prr == 0) &&
6846 		     (rack->r_ctl.rc_prr_sndcnt  < ctf_fixed_maxseg(tp))) {
6847 			/*
6848 			 * We are not cheating, in recovery  and
6849 			 * not enough ack's to yet get our next
6850 			 * retransmission out.
6851 			 *
6852 			 * Note that classified attackers do not
6853 			 * get to use the rack-cheat.
6854 			 */
6855 			goto activate_tlp;
6856 		}
6857 		srtt = rack_grab_rtt(tp, rack);
6858 		thresh = rack_calc_thresh_rack(rack, srtt, cts, __LINE__, 1);
6859 		idx = rsm->r_rtr_cnt - 1;
6860 		exp = ((uint32_t)rsm->r_tim_lastsent[idx]) + thresh;
6861 		if (SEQ_GEQ(exp, cts)) {
6862 			to = exp - cts;
6863 			if (to < rack->r_ctl.rc_min_to) {
6864 				to = rack->r_ctl.rc_min_to;
6865 				if (rack->r_rr_config == 3)
6866 					rack->rc_on_min_to = 1;
6867 			}
6868 		} else {
6869 			to = rack->r_ctl.rc_min_to;
6870 			if (rack->r_rr_config == 3)
6871 				rack->rc_on_min_to = 1;
6872 		}
6873 	} else {
6874 		/* Ok we need to do a TLP not RACK */
6875 activate_tlp:
6876 		if ((rack->rc_tlp_in_progress != 0) &&
6877 		    (rack->r_ctl.rc_tlp_cnt_out >= rack_tlp_limit)) {
6878 			/*
6879 			 * The previous send was a TLP and we have sent
6880 			 * N TLP's without sending new data.
6881 			 */
6882 			goto activate_rxt;
6883 		}
6884 		rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
6885 		if (rsm == NULL) {
6886 			/* We found no rsm to TLP with. */
6887 			goto activate_rxt;
6888 		}
6889 		if (rsm->r_flags & RACK_HAS_FIN) {
6890 			/* If its a FIN we dont do TLP */
6891 			rsm = NULL;
6892 			goto activate_rxt;
6893 		}
6894 		idx = rsm->r_rtr_cnt - 1;
6895 		time_since_sent = 0;
6896 		if (TSTMP_GEQ(((uint32_t)rsm->r_tim_lastsent[idx]), rack->r_ctl.rc_tlp_rxt_last_time))
6897 			tstmp_touse = (uint32_t)rsm->r_tim_lastsent[idx];
6898 		else
6899 			tstmp_touse = (uint32_t)rack->r_ctl.rc_tlp_rxt_last_time;
6900 		if (TSTMP_GT(cts, tstmp_touse))
6901 		    time_since_sent = cts - tstmp_touse;
6902 		is_tlp_timer = 1;
6903 		if (tp->t_srtt) {
6904 			if ((rack->rc_srtt_measure_made == 0) &&
6905 			    (tp->t_srtt == 1)) {
6906 				/*
6907 				 * If another stack as run and set srtt to 1,
6908 				 * then the srtt was 0, so lets use the initial.
6909 				 */
6910 				srtt = RACK_INITIAL_RTO;
6911 			} else {
6912 				srtt_cur = tp->t_srtt;
6913 				srtt = srtt_cur;
6914 			}
6915 		} else
6916 			srtt = RACK_INITIAL_RTO;
6917 		/*
6918 		 * If the SRTT is not keeping up and the
6919 		 * rack RTT has spiked we want to use
6920 		 * the last RTT not the smoothed one.
6921 		 */
6922 		if (rack_tlp_use_greater &&
6923 		    tp->t_srtt &&
6924 		    (srtt < rack_grab_rtt(tp, rack))) {
6925 			srtt = rack_grab_rtt(tp, rack);
6926 		}
6927 		thresh = rack_calc_thresh_tlp(tp, rack, rsm, srtt);
6928 		if (thresh > time_since_sent) {
6929 			to = thresh - time_since_sent;
6930 		} else {
6931 			to = rack->r_ctl.rc_min_to;
6932 			rack_log_alt_to_to_cancel(rack,
6933 						  thresh,		/* flex1 */
6934 						  time_since_sent,	/* flex2 */
6935 						  tstmp_touse,		/* flex3 */
6936 						  rack->r_ctl.rc_tlp_rxt_last_time, /* flex4 */
6937 						  (uint32_t)rsm->r_tim_lastsent[idx],
6938 						  srtt,
6939 						  idx, 99);
6940 		}
6941 		if (to < rack_tlp_min) {
6942 			to = rack_tlp_min;
6943 		}
6944 		if (to > TICKS_2_USEC(TCPTV_REXMTMAX)) {
6945 			/*
6946 			 * If the TLP time works out to larger than the max
6947 			 * RTO lets not do TLP.. just RTO.
6948 			 */
6949 			goto activate_rxt;
6950 		}
6951 	}
6952 	if (is_tlp_timer == 0) {
6953 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_RACK;
6954 	} else {
6955 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_TLP;
6956 	}
6957 	if (to == 0)
6958 		to = 1;
6959 	return (to);
6960 }
6961 
6962 static void
rack_enter_persist(struct tcpcb * tp,struct tcp_rack * rack,uint32_t cts,tcp_seq snd_una)6963 rack_enter_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, tcp_seq snd_una)
6964 {
6965 	if (rack->rc_in_persist == 0) {
6966 		if (tp->t_flags & TF_GPUTINPROG) {
6967 			/*
6968 			 * Stop the goodput now, the calling of the
6969 			 * measurement function clears the flag.
6970 			 */
6971 			rack_do_goodput_measurement(tp, rack, tp->snd_una, __LINE__,
6972 						    RACK_QUALITY_PERSIST);
6973 		}
6974 #ifdef NETFLIX_SHARED_CWND
6975 		if (rack->r_ctl.rc_scw) {
6976 			tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
6977 			rack->rack_scwnd_is_idle = 1;
6978 		}
6979 #endif
6980 		rack->r_ctl.rc_went_idle_time = cts;
6981 		if (rack->r_ctl.rc_went_idle_time == 0)
6982 			rack->r_ctl.rc_went_idle_time = 1;
6983 		if (rack->lt_bw_up) {
6984 			/* Suspend our LT BW measurement */
6985 			uint64_t tmark;
6986 
6987 			rack->r_ctl.lt_bw_bytes += (snd_una - rack->r_ctl.lt_seq);
6988 			rack->r_ctl.lt_seq = snd_una;
6989 			tmark = tcp_tv_to_lusectick(&rack->r_ctl.act_rcv_time);
6990 			if (tmark >= rack->r_ctl.lt_timemark) {
6991 				rack->r_ctl.lt_bw_time += (tmark - rack->r_ctl.lt_timemark);
6992 			}
6993 			rack->r_ctl.lt_timemark = tmark;
6994 			rack->lt_bw_up = 0;
6995 			rack->r_persist_lt_bw_off = 1;
6996 		}
6997 		rack_timer_cancel(tp, rack, cts, __LINE__);
6998 		rack->r_ctl.persist_lost_ends = 0;
6999 		rack->probe_not_answered = 0;
7000 		rack->forced_ack = 0;
7001 		tp->t_rxtshift = 0;
7002 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
7003 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
7004 		rack->rc_in_persist = 1;
7005 	}
7006 }
7007 
7008 static void
rack_exit_persist(struct tcpcb * tp,struct tcp_rack * rack,uint32_t cts)7009 rack_exit_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
7010 {
7011 	if (tcp_in_hpts(rack->rc_tp)) {
7012 		tcp_hpts_remove(rack->rc_tp);
7013 		rack->r_ctl.rc_hpts_flags = 0;
7014 	}
7015 #ifdef NETFLIX_SHARED_CWND
7016 	if (rack->r_ctl.rc_scw) {
7017 		tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
7018 		rack->rack_scwnd_is_idle = 0;
7019 	}
7020 #endif
7021 	if (rack->rc_gp_dyn_mul &&
7022 	    (rack->use_fixed_rate == 0) &&
7023 	    (rack->rc_always_pace)) {
7024 		/*
7025 		 * Do we count this as if a probe-rtt just
7026 		 * finished?
7027 		 */
7028 		uint32_t time_idle, idle_min;
7029 
7030 		time_idle = cts - rack->r_ctl.rc_went_idle_time;
7031 		idle_min = rack_min_probertt_hold;
7032 		if (rack_probertt_gpsrtt_cnt_div) {
7033 			uint64_t extra;
7034 			extra = (uint64_t)rack->r_ctl.rc_gp_srtt *
7035 				(uint64_t)rack_probertt_gpsrtt_cnt_mul;
7036 			extra /= (uint64_t)rack_probertt_gpsrtt_cnt_div;
7037 			idle_min += (uint32_t)extra;
7038 		}
7039 		if (time_idle >= idle_min) {
7040 			/* Yes, we count it as a probe-rtt. */
7041 			uint32_t us_cts;
7042 
7043 			us_cts = tcp_get_usecs(NULL);
7044 			if (rack->in_probe_rtt == 0) {
7045 				rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
7046 				rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
7047 				rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
7048 				rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
7049 			} else {
7050 				rack_exit_probertt(rack, us_cts);
7051 			}
7052 		}
7053 	}
7054 	if (rack->r_persist_lt_bw_off) {
7055 		/* Continue where we left off */
7056 		rack->r_ctl.lt_timemark = tcp_get_u64_usecs(NULL);
7057 		rack->lt_bw_up = 1;
7058 		rack->r_persist_lt_bw_off = 0;
7059 	}
7060 	rack->r_ctl.idle_snd_una = tp->snd_una;
7061 	rack->rc_in_persist = 0;
7062 	rack->r_ctl.rc_went_idle_time = 0;
7063 	tp->t_rxtshift = 0;
7064 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
7065 	   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
7066 	rack->r_ctl.rc_agg_delayed = 0;
7067 	rack->r_early = 0;
7068 	rack->r_late = 0;
7069 	rack->r_ctl.rc_agg_early = 0;
7070 }
7071 
7072 static void
rack_log_hpts_diag(struct tcp_rack * rack,uint32_t cts,struct hpts_diag * diag,struct timeval * tv)7073 rack_log_hpts_diag(struct tcp_rack *rack, uint32_t cts,
7074 		   struct hpts_diag *diag, struct timeval *tv)
7075 {
7076 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
7077 		union tcp_log_stackspecific log;
7078 
7079 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
7080 		log.u_bbr.flex1 = diag->p_nxt_slot;
7081 		log.u_bbr.flex2 = diag->p_cur_slot;
7082 		log.u_bbr.flex3 = diag->slot_req;
7083 		log.u_bbr.flex4 = diag->inp_hptsslot;
7084 		log.u_bbr.flex5 = diag->slot_remaining;
7085 		log.u_bbr.flex6 = diag->need_new_to;
7086 		log.u_bbr.flex7 = diag->p_hpts_active;
7087 		log.u_bbr.flex8 = diag->p_on_min_sleep;
7088 		/* Hijack other fields as needed */
7089 		log.u_bbr.epoch = diag->have_slept;
7090 		log.u_bbr.lt_epoch = diag->yet_to_sleep;
7091 		log.u_bbr.pkts_out = diag->co_ret;
7092 		log.u_bbr.applimited = diag->hpts_sleep_time;
7093 		log.u_bbr.delivered = diag->p_prev_slot;
7094 		log.u_bbr.inflight = diag->p_runningslot;
7095 		log.u_bbr.bw_inuse = diag->wheel_slot;
7096 		log.u_bbr.rttProp = diag->wheel_cts;
7097 		log.u_bbr.timeStamp = cts;
7098 		log.u_bbr.delRate = diag->maxslots;
7099 		log.u_bbr.cur_del_rate = diag->p_curtick;
7100 		log.u_bbr.cur_del_rate <<= 32;
7101 		log.u_bbr.cur_del_rate |= diag->p_lasttick;
7102 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
7103 		    &rack->rc_inp->inp_socket->so_rcv,
7104 		    &rack->rc_inp->inp_socket->so_snd,
7105 		    BBR_LOG_HPTSDIAG, 0,
7106 		    0, &log, false, tv);
7107 	}
7108 
7109 }
7110 
7111 static void
rack_log_wakeup(struct tcpcb * tp,struct tcp_rack * rack,struct sockbuf * sb,uint32_t len,int type)7112 rack_log_wakeup(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb, uint32_t len, int type)
7113 {
7114 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
7115 		union tcp_log_stackspecific log;
7116 		struct timeval tv;
7117 
7118 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
7119 		log.u_bbr.flex1 = sb->sb_flags;
7120 		log.u_bbr.flex2 = len;
7121 		log.u_bbr.flex3 = sb->sb_state;
7122 		log.u_bbr.flex8 = type;
7123 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
7124 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
7125 		    &rack->rc_inp->inp_socket->so_rcv,
7126 		    &rack->rc_inp->inp_socket->so_snd,
7127 		    TCP_LOG_SB_WAKE, 0,
7128 		    len, &log, false, &tv);
7129 	}
7130 }
7131 
7132 static void
rack_start_hpts_timer(struct tcp_rack * rack,struct tcpcb * tp,uint32_t cts,int32_t slot,uint32_t tot_len_this_send,int sup_rack)7133 rack_start_hpts_timer (struct tcp_rack *rack, struct tcpcb *tp, uint32_t cts,
7134       int32_t slot, uint32_t tot_len_this_send, int sup_rack)
7135 {
7136 	struct hpts_diag diag;
7137 	struct inpcb *inp = tptoinpcb(tp);
7138 	struct timeval tv;
7139 	uint32_t delayed_ack = 0;
7140 	uint32_t hpts_timeout;
7141 	uint32_t entry_slot = slot;
7142 	uint8_t stopped;
7143 	uint32_t left = 0;
7144 	uint32_t us_cts;
7145 
7146 	if ((tp->t_state == TCPS_CLOSED) ||
7147 	    (tp->t_state == TCPS_LISTEN)) {
7148 		return;
7149 	}
7150 	if (tcp_in_hpts(tp)) {
7151 		/* Already on the pacer */
7152 		return;
7153 	}
7154 	stopped = rack->rc_tmr_stopped;
7155 	if (stopped && TSTMP_GT(rack->r_ctl.rc_timer_exp, cts)) {
7156 		left = rack->r_ctl.rc_timer_exp - cts;
7157 	}
7158 	rack->r_ctl.rc_timer_exp = 0;
7159 	rack->r_ctl.rc_hpts_flags = 0;
7160 	us_cts = tcp_get_usecs(&tv);
7161 	/* Now early/late accounting */
7162 	rack_log_pacing_delay_calc(rack, entry_slot, slot, 0, 0, 0, 26, __LINE__, NULL, 0);
7163 	if (rack->r_early && (rack->rc_ack_can_sendout_data == 0)) {
7164 		/*
7165 		 * We have a early carry over set,
7166 		 * we can always add more time so we
7167 		 * can always make this compensation.
7168 		 *
7169 		 * Note if ack's are allowed to wake us do not
7170 		 * penalize the next timer for being awoke
7171 		 * by an ack aka the rc_agg_early (non-paced mode).
7172 		 */
7173 		slot += rack->r_ctl.rc_agg_early;
7174 		rack->r_early = 0;
7175 		rack->r_ctl.rc_agg_early = 0;
7176 	}
7177 	if ((rack->r_late) &&
7178 	    ((rack->r_use_hpts_min == 0) || (rack->dgp_on == 0))) {
7179 		/*
7180 		 * This is harder, we can
7181 		 * compensate some but it
7182 		 * really depends on what
7183 		 * the current pacing time is.
7184 		 */
7185 		if (rack->r_ctl.rc_agg_delayed >= slot) {
7186 			/*
7187 			 * We can't compensate for it all.
7188 			 * And we have to have some time
7189 			 * on the clock. We always have a min
7190 			 * 10 slots (10 x 10 i.e. 100 usecs).
7191 			 */
7192 			if (slot <= HPTS_TICKS_PER_SLOT) {
7193 				/* We gain delay */
7194 				rack->r_ctl.rc_agg_delayed += (HPTS_TICKS_PER_SLOT - slot);
7195 				slot = HPTS_TICKS_PER_SLOT;
7196 			} else {
7197 				/* We take off some */
7198 				rack->r_ctl.rc_agg_delayed -= (slot - HPTS_TICKS_PER_SLOT);
7199 				slot = HPTS_TICKS_PER_SLOT;
7200 			}
7201 		} else {
7202 			slot -= rack->r_ctl.rc_agg_delayed;
7203 			rack->r_ctl.rc_agg_delayed = 0;
7204 			/* Make sure we have 100 useconds at minimum */
7205 			if (slot < HPTS_TICKS_PER_SLOT) {
7206 				rack->r_ctl.rc_agg_delayed = HPTS_TICKS_PER_SLOT - slot;
7207 				slot = HPTS_TICKS_PER_SLOT;
7208 			}
7209 			if (rack->r_ctl.rc_agg_delayed == 0)
7210 				rack->r_late = 0;
7211 		}
7212 	} else if (rack->r_late) {
7213 		/* r_use_hpts_min is on and so is DGP */
7214 		uint32_t max_red;
7215 
7216 		max_red = (slot * rack->r_ctl.max_reduction) / 100;
7217 		if (max_red >= rack->r_ctl.rc_agg_delayed) {
7218 			slot -= rack->r_ctl.rc_agg_delayed;
7219 			rack->r_ctl.rc_agg_delayed = 0;
7220 		} else {
7221 			slot -= max_red;
7222 			rack->r_ctl.rc_agg_delayed -= max_red;
7223 		}
7224 	}
7225 	if ((rack->r_use_hpts_min == 1) &&
7226 	    (slot > 0) &&
7227 	    (rack->dgp_on == 1)) {
7228 		/*
7229 		 * We are enforcing a min pacing timer
7230 		 * based on our hpts min timeout.
7231 		 */
7232 		uint32_t min;
7233 
7234 		min = get_hpts_min_sleep_time();
7235 		if (min > slot) {
7236 			slot = min;
7237 		}
7238 	}
7239 	hpts_timeout = rack_timer_start(tp, rack, cts, sup_rack);
7240 	if (tp->t_flags & TF_DELACK) {
7241 		delayed_ack = TICKS_2_USEC(tcp_delacktime);
7242 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_DELACK;
7243 	}
7244 	if (delayed_ack && ((hpts_timeout == 0) ||
7245 			    (delayed_ack < hpts_timeout)))
7246 		hpts_timeout = delayed_ack;
7247 	else
7248 		rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
7249 	/*
7250 	 * If no timers are going to run and we will fall off the hptsi
7251 	 * wheel, we resort to a keep-alive timer if its configured.
7252 	 */
7253 	if ((hpts_timeout == 0) &&
7254 	    (slot == 0)) {
7255 		if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
7256 		    (tp->t_state <= TCPS_CLOSING)) {
7257 			/*
7258 			 * Ok we have no timer (persists, rack, tlp, rxt  or
7259 			 * del-ack), we don't have segments being paced. So
7260 			 * all that is left is the keepalive timer.
7261 			 */
7262 			if (TCPS_HAVEESTABLISHED(tp->t_state)) {
7263 				/* Get the established keep-alive time */
7264 				hpts_timeout = TICKS_2_USEC(TP_KEEPIDLE(tp));
7265 			} else {
7266 				/*
7267 				 * Get the initial setup keep-alive time,
7268 				 * note that this is probably not going to
7269 				 * happen, since rack will be running a rxt timer
7270 				 * if a SYN of some sort is outstanding. It is
7271 				 * actually handled in rack_timeout_rxt().
7272 				 */
7273 				hpts_timeout = TICKS_2_USEC(TP_KEEPINIT(tp));
7274 			}
7275 			rack->r_ctl.rc_hpts_flags |= PACE_TMR_KEEP;
7276 			if (rack->in_probe_rtt) {
7277 				/*
7278 				 * We want to instead not wake up a long time from
7279 				 * now but to wake up about the time we would
7280 				 * exit probe-rtt and initiate a keep-alive ack.
7281 				 * This will get us out of probe-rtt and update
7282 				 * our min-rtt.
7283 				 */
7284 				hpts_timeout = rack_min_probertt_hold;
7285 			}
7286 		}
7287 	}
7288 	if (left && (stopped & (PACE_TMR_KEEP | PACE_TMR_DELACK)) ==
7289 	    (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK)) {
7290 		/*
7291 		 * RACK, TLP, persists and RXT timers all are restartable
7292 		 * based on actions input .. i.e we received a packet (ack
7293 		 * or sack) and that changes things (rw, or snd_una etc).
7294 		 * Thus we can restart them with a new value. For
7295 		 * keep-alive, delayed_ack we keep track of what was left
7296 		 * and restart the timer with a smaller value.
7297 		 */
7298 		if (left < hpts_timeout)
7299 			hpts_timeout = left;
7300 	}
7301 	if (hpts_timeout) {
7302 		/*
7303 		 * Hack alert for now we can't time-out over 2,147,483
7304 		 * seconds (a bit more than 596 hours), which is probably ok
7305 		 * :).
7306 		 */
7307 		if (hpts_timeout > 0x7ffffffe)
7308 			hpts_timeout = 0x7ffffffe;
7309 		rack->r_ctl.rc_timer_exp = cts + hpts_timeout;
7310 	}
7311 	rack_log_pacing_delay_calc(rack, entry_slot, slot, hpts_timeout, 0, 0, 27, __LINE__, NULL, 0);
7312 	if ((rack->gp_ready == 0) &&
7313 	    (rack->use_fixed_rate == 0) &&
7314 	    (hpts_timeout < slot) &&
7315 	    (rack->r_ctl.rc_hpts_flags & (PACE_TMR_TLP|PACE_TMR_RXT))) {
7316 		/*
7317 		 * We have no good estimate yet for the
7318 		 * old clunky burst mitigation or the
7319 		 * real pacing. And the tlp or rxt is smaller
7320 		 * than the pacing calculation. Lets not
7321 		 * pace that long since we know the calculation
7322 		 * so far is not accurate.
7323 		 */
7324 		slot = hpts_timeout;
7325 	}
7326 	/**
7327 	 * Turn off all the flags for queuing by default. The
7328 	 * flags have important meanings to what happens when
7329 	 * LRO interacts with the transport. Most likely (by default now)
7330 	 * mbuf_queueing and ack compression are on. So the transport
7331 	 * has a couple of flags that control what happens (if those
7332 	 * are not on then these flags won't have any effect since it
7333 	 * won't go through the queuing LRO path).
7334 	 *
7335 	 * TF2_MBUF_QUEUE_READY - This flags says that I am busy
7336 	 *                        pacing output, so don't disturb. But
7337 	 *                        it also means LRO can wake me if there
7338 	 *                        is a SACK arrival.
7339 	 *
7340 	 * TF2_DONT_SACK_QUEUE - This flag is used in conjunction
7341 	 *                       with the above flag (QUEUE_READY) and
7342 	 *                       when present it says don't even wake me
7343 	 *                       if a SACK arrives.
7344 	 *
7345 	 * The idea behind these flags is that if we are pacing we
7346 	 * set the MBUF_QUEUE_READY and only get woken up if
7347 	 * a SACK arrives (which could change things) or if
7348 	 * our pacing timer expires. If, however, we have a rack
7349 	 * timer running, then we don't even want a sack to wake
7350 	 * us since the rack timer has to expire before we can send.
7351 	 *
7352 	 * Other cases should usually have none of the flags set
7353 	 * so LRO can call into us.
7354 	 */
7355 	tp->t_flags2 &= ~(TF2_DONT_SACK_QUEUE|TF2_MBUF_QUEUE_READY);
7356 	if (slot) {
7357 		rack->r_ctl.rc_hpts_flags |= PACE_PKT_OUTPUT;
7358 		rack->r_ctl.rc_last_output_to = us_cts + slot;
7359 		/*
7360 		 * A pacing timer (slot) is being set, in
7361 		 * such a case we cannot send (we are blocked by
7362 		 * the timer). So lets tell LRO that it should not
7363 		 * wake us unless there is a SACK. Note this only
7364 		 * will be effective if mbuf queueing is on or
7365 		 * compressed acks are being processed.
7366 		 */
7367 		tp->t_flags2 |= TF2_MBUF_QUEUE_READY;
7368 		/*
7369 		 * But wait if we have a Rack timer running
7370 		 * even a SACK should not disturb us (with
7371 		 * the exception of r_rr_config 3).
7372 		 */
7373 		if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK) ||
7374 		    (IN_RECOVERY(tp->t_flags))) {
7375 			if (rack->r_rr_config != 3)
7376 				tp->t_flags2 |= TF2_DONT_SACK_QUEUE;
7377 			else if (rack->rc_pace_dnd) {
7378 				/*
7379 				 * When DND is on, we only let a sack
7380 				 * interrupt us if we are not in recovery.
7381 				 *
7382 				 * If DND is off, then we never hit here
7383 				 * and let all sacks wake us up.
7384 				 *
7385 				 */
7386 				tp->t_flags2 |= TF2_DONT_SACK_QUEUE;
7387 			}
7388 		}
7389 		if (rack->rc_ack_can_sendout_data) {
7390 			/*
7391 			 * Ahh but wait, this is that special case
7392 			 * where the pacing timer can be disturbed
7393 			 * backout the changes (used for non-paced
7394 			 * burst limiting).
7395 			 */
7396 			tp->t_flags2 &= ~(TF2_DONT_SACK_QUEUE |
7397 			    TF2_MBUF_QUEUE_READY);
7398 		}
7399 		if ((rack->use_rack_rr) &&
7400 		    (rack->r_rr_config < 2) &&
7401 		    ((hpts_timeout) && (hpts_timeout < slot))) {
7402 			/*
7403 			 * Arrange for the hpts to kick back in after the
7404 			 * t-o if the t-o does not cause a send.
7405 			 */
7406 			(void)tcp_hpts_insert_diag(tp, HPTS_USEC_TO_SLOTS(hpts_timeout),
7407 						   __LINE__, &diag);
7408 			rack_log_hpts_diag(rack, us_cts, &diag, &tv);
7409 			rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
7410 		} else {
7411 			(void)tcp_hpts_insert_diag(tp, HPTS_USEC_TO_SLOTS(slot),
7412 						   __LINE__, &diag);
7413 			rack_log_hpts_diag(rack, us_cts, &diag, &tv);
7414 			rack_log_to_start(rack, cts, hpts_timeout, slot, 1);
7415 		}
7416 	} else if (hpts_timeout) {
7417 		/*
7418 		 * With respect to t_flags2(?) here, lets let any new acks wake
7419 		 * us up here. Since we are not pacing (no pacing timer), output
7420 		 * can happen so we should let it. If its a Rack timer, then any inbound
7421 		 * packet probably won't change the sending (we will be blocked)
7422 		 * but it may change the prr stats so letting it in (the set defaults
7423 		 * at the start of this block) are good enough.
7424 		 */
7425 		rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
7426 		(void)tcp_hpts_insert_diag(tp, HPTS_USEC_TO_SLOTS(hpts_timeout),
7427 					   __LINE__, &diag);
7428 		rack_log_hpts_diag(rack, us_cts, &diag, &tv);
7429 		rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
7430 	} else {
7431 		/* No timer starting */
7432 #ifdef INVARIANTS
7433 		if (SEQ_GT(tp->snd_max, tp->snd_una)) {
7434 			panic("tp:%p rack:%p tlts:%d cts:%u slot:%u pto:%u -- no timer started?",
7435 			    tp, rack, tot_len_this_send, cts, slot, hpts_timeout);
7436 		}
7437 #endif
7438 	}
7439 	rack->rc_tmr_stopped = 0;
7440 	if (slot)
7441 		rack_log_type_bbrsnd(rack, tot_len_this_send, slot, us_cts, &tv, __LINE__);
7442 }
7443 
7444 static void
rack_mark_lost(struct tcpcb * tp,struct tcp_rack * rack,struct rack_sendmap * rsm,uint32_t cts)7445 rack_mark_lost(struct tcpcb *tp,
7446     struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t cts)
7447 {
7448 	struct rack_sendmap *nrsm;
7449 	uint32_t thresh,  exp;
7450 
7451 	thresh = rack_calc_thresh_rack(rack, rack_grab_rtt(tp, rack), cts, __LINE__, 0);
7452 	nrsm = rsm;
7453 	TAILQ_FOREACH_FROM(nrsm, &rack->r_ctl.rc_tmap, r_tnext) {
7454 		if ((nrsm->r_flags & RACK_SACK_PASSED) == 0) {
7455 			/* Got up to all that were marked sack-passed */
7456 			break;
7457 		}
7458 		if ((nrsm->r_flags & RACK_WAS_LOST) == 0) {
7459 			exp = ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]) + thresh;
7460 			if (TSTMP_LT(exp, cts) || (exp == cts)) {
7461 				/* We now consider it lost */
7462 				nrsm->r_flags |= RACK_WAS_LOST;
7463 				rack->r_ctl.rc_considered_lost += nrsm->r_end - nrsm->r_start;
7464 			} else {
7465 				/* Past here it won't be lost so stop */
7466 				break;
7467 			}
7468 		}
7469 	}
7470 }
7471 
7472 /*
7473  * RACK Timer, here we simply do logging and house keeping.
7474  * the normal rack_output() function will call the
7475  * appropriate thing to check if we need to do a RACK retransmit.
7476  * We return 1, saying don't proceed with rack_output only
7477  * when all timers have been stopped (destroyed PCB?).
7478  */
7479 static int
rack_timeout_rack(struct tcpcb * tp,struct tcp_rack * rack,uint32_t cts)7480 rack_timeout_rack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
7481 {
7482 	/*
7483 	 * This timer simply provides an internal trigger to send out data.
7484 	 * The check_recovery_mode call will see if there are needed
7485 	 * retransmissions, if so we will enter fast-recovery. The output
7486 	 * call may or may not do the same thing depending on sysctl
7487 	 * settings.
7488 	 */
7489 	struct rack_sendmap *rsm;
7490 
7491 	counter_u64_add(rack_to_tot, 1);
7492 	if (rack->r_state && (rack->r_state != tp->t_state))
7493 		rack_set_state(tp, rack);
7494 	rack->rc_on_min_to = 0;
7495 	rsm = rack_check_recovery_mode(tp, cts);
7496 	rack_log_to_event(rack, RACK_TO_FRM_RACK, rsm);
7497 	if (rsm) {
7498 		/* We need to stroke any lost that are now declared as lost */
7499 		rack_mark_lost(tp, rack, rsm, cts);
7500 		rack->r_ctl.rc_resend = rsm;
7501 		rack->r_timer_override = 1;
7502 		if (rack->use_rack_rr) {
7503 			/*
7504 			 * Don't accumulate extra pacing delay
7505 			 * we are allowing the rack timer to
7506 			 * over-ride pacing i.e. rrr takes precedence
7507 			 * if the pacing interval is longer than the rrr
7508 			 * time (in other words we get the min pacing
7509 			 * time versus rrr pacing time).
7510 			 */
7511 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
7512 		}
7513 	}
7514 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RACK;
7515 	if (rsm == NULL) {
7516 		/* restart a timer and return 1 */
7517 		rack_start_hpts_timer(rack, tp, cts,
7518 				      0, 0, 0);
7519 		return (1);
7520 	}
7521 	if ((rack->policer_detect_on == 1) &&
7522 	    (rack->rc_policer_detected == 0)) {
7523 		/*
7524 		 * We do this early if we have not
7525 		 * deteceted to attempt to detect
7526 		 * quicker. Normally we want to do this
7527 		 * as recovery exits (and we will again).
7528 		 */
7529 		policer_detection(tp, rack, 0);
7530 	}
7531 	return (0);
7532 }
7533 
7534 
7535 
7536 static void
rack_adjust_orig_mlen(struct rack_sendmap * rsm)7537 rack_adjust_orig_mlen(struct rack_sendmap *rsm)
7538 {
7539 
7540 	if ((M_TRAILINGROOM(rsm->m) != rsm->orig_t_space)) {
7541 		/*
7542 		 * The trailing space changed, mbufs can grow
7543 		 * at the tail but they can't shrink from
7544 		 * it, KASSERT that. Adjust the orig_m_len to
7545 		 * compensate for this change.
7546 		 */
7547 		KASSERT((rsm->orig_t_space > M_TRAILINGROOM(rsm->m)),
7548 			("mbuf:%p rsm:%p trailing_space:%jd ots:%u oml:%u mlen:%u\n",
7549 			 rsm->m,
7550 			 rsm,
7551 			 (intmax_t)M_TRAILINGROOM(rsm->m),
7552 			 rsm->orig_t_space,
7553 			 rsm->orig_m_len,
7554 			 rsm->m->m_len));
7555 		rsm->orig_m_len += (rsm->orig_t_space - M_TRAILINGROOM(rsm->m));
7556 		rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
7557 	}
7558 	if (rsm->m->m_len < rsm->orig_m_len) {
7559 		/*
7560 		 * Mbuf shrank, trimmed off the top by an ack, our
7561 		 * offset changes.
7562 		 */
7563 		KASSERT((rsm->soff >= (rsm->orig_m_len - rsm->m->m_len)),
7564 			("mbuf:%p len:%u rsm:%p oml:%u soff:%u\n",
7565 			 rsm->m, rsm->m->m_len,
7566 			 rsm, rsm->orig_m_len,
7567 			 rsm->soff));
7568 		if (rsm->soff >= (rsm->orig_m_len - rsm->m->m_len))
7569 			rsm->soff -= (rsm->orig_m_len - rsm->m->m_len);
7570 		else
7571 			rsm->soff = 0;
7572 		rsm->orig_m_len = rsm->m->m_len;
7573 #ifdef INVARIANTS
7574 	} else if (rsm->m->m_len > rsm->orig_m_len) {
7575 		panic("rsm:%p m:%p m_len grew outside of t_space compensation",
7576 		      rsm, rsm->m);
7577 #endif
7578 	}
7579 }
7580 
7581 static void
rack_setup_offset_for_rsm(struct tcp_rack * rack,struct rack_sendmap * src_rsm,struct rack_sendmap * rsm)7582 rack_setup_offset_for_rsm(struct tcp_rack *rack, struct rack_sendmap *src_rsm, struct rack_sendmap *rsm)
7583 {
7584 	struct mbuf *m;
7585 	uint32_t soff;
7586 
7587 	if (src_rsm->m &&
7588 	    ((src_rsm->orig_m_len != src_rsm->m->m_len) ||
7589 	     (M_TRAILINGROOM(src_rsm->m) != src_rsm->orig_t_space))) {
7590 		/* Fix up the orig_m_len and possibly the mbuf offset */
7591 		rack_adjust_orig_mlen(src_rsm);
7592 	}
7593 	m = src_rsm->m;
7594 	soff = src_rsm->soff + (src_rsm->r_end - src_rsm->r_start);
7595 	while (soff >= m->m_len) {
7596 		/* Move out past this mbuf */
7597 		soff -= m->m_len;
7598 		m = m->m_next;
7599 		KASSERT((m != NULL),
7600 			("rsm:%p nrsm:%p hit at soff:%u null m",
7601 			 src_rsm, rsm, soff));
7602 		if (m == NULL) {
7603 			/* This should *not* happen which is why there is a kassert */
7604 			src_rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd,
7605 					       (src_rsm->r_start - rack->rc_tp->snd_una),
7606 					       &src_rsm->soff);
7607 			src_rsm->orig_m_len = src_rsm->m->m_len;
7608 			src_rsm->orig_t_space = M_TRAILINGROOM(src_rsm->m);
7609 			rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd,
7610 					   (rsm->r_start - rack->rc_tp->snd_una),
7611 					   &rsm->soff);
7612 			rsm->orig_m_len = rsm->m->m_len;
7613 			rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
7614 			return;
7615 		}
7616 	}
7617 	rsm->m = m;
7618 	rsm->soff = soff;
7619 	rsm->orig_m_len = m->m_len;
7620 	rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
7621 }
7622 
7623 static __inline void
rack_clone_rsm(struct tcp_rack * rack,struct rack_sendmap * nrsm,struct rack_sendmap * rsm,uint32_t start)7624 rack_clone_rsm(struct tcp_rack *rack, struct rack_sendmap *nrsm,
7625 	       struct rack_sendmap *rsm, uint32_t start)
7626 {
7627 	int idx;
7628 
7629 	nrsm->r_start = start;
7630 	nrsm->r_end = rsm->r_end;
7631 	nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
7632 	nrsm->r_act_rxt_cnt = rsm->r_act_rxt_cnt;
7633 	nrsm->r_flags = rsm->r_flags;
7634 	nrsm->r_dupack = rsm->r_dupack;
7635 	nrsm->r_no_rtt_allowed = rsm->r_no_rtt_allowed;
7636 	nrsm->r_rtr_bytes = 0;
7637 	nrsm->r_fas = rsm->r_fas;
7638 	nrsm->r_bas = rsm->r_bas;
7639 	tqhash_update_end(rack->r_ctl.tqh, rsm, nrsm->r_start);
7640 	nrsm->r_just_ret = rsm->r_just_ret;
7641 	for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
7642 		nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
7643 	}
7644 	/* Now if we have SYN flag we keep it on the left edge */
7645 	if (nrsm->r_flags & RACK_HAS_SYN)
7646 		nrsm->r_flags &= ~RACK_HAS_SYN;
7647 	/* Now if we have a FIN flag we keep it on the right edge */
7648 	if (rsm->r_flags & RACK_HAS_FIN)
7649 		rsm->r_flags &= ~RACK_HAS_FIN;
7650 	/* Push bit must go to the right edge as well */
7651 	if (rsm->r_flags & RACK_HAD_PUSH)
7652 		rsm->r_flags &= ~RACK_HAD_PUSH;
7653 	/* Clone over the state of the hw_tls flag */
7654 	nrsm->r_hw_tls = rsm->r_hw_tls;
7655 	/*
7656 	 * Now we need to find nrsm's new location in the mbuf chain
7657 	 * we basically calculate a new offset, which is soff +
7658 	 * how much is left in original rsm. Then we walk out the mbuf
7659 	 * chain to find the righ position, it may be the same mbuf
7660 	 * or maybe not.
7661 	 */
7662 	KASSERT(((rsm->m != NULL) ||
7663 		 (rsm->r_flags & (RACK_HAS_SYN|RACK_HAS_FIN))),
7664 		("rsm:%p nrsm:%p rack:%p -- rsm->m is NULL?", rsm, nrsm, rack));
7665 	if (rsm->m)
7666 		rack_setup_offset_for_rsm(rack, rsm, nrsm);
7667 }
7668 
7669 static struct rack_sendmap *
rack_merge_rsm(struct tcp_rack * rack,struct rack_sendmap * l_rsm,struct rack_sendmap * r_rsm)7670 rack_merge_rsm(struct tcp_rack *rack,
7671 	       struct rack_sendmap *l_rsm,
7672 	       struct rack_sendmap *r_rsm)
7673 {
7674 	/*
7675 	 * We are merging two ack'd RSM's,
7676 	 * the l_rsm is on the left (lower seq
7677 	 * values) and the r_rsm is on the right
7678 	 * (higher seq value). The simplest way
7679 	 * to merge these is to move the right
7680 	 * one into the left. I don't think there
7681 	 * is any reason we need to try to find
7682 	 * the oldest (or last oldest retransmitted).
7683 	 */
7684 	rack_log_map_chg(rack->rc_tp, rack, NULL,
7685 			 l_rsm, r_rsm, MAP_MERGE, r_rsm->r_end, __LINE__);
7686 	tqhash_update_end(rack->r_ctl.tqh, l_rsm, r_rsm->r_end);
7687 	if (l_rsm->r_dupack < r_rsm->r_dupack)
7688 		l_rsm->r_dupack = r_rsm->r_dupack;
7689 	if (r_rsm->r_rtr_bytes)
7690 		l_rsm->r_rtr_bytes += r_rsm->r_rtr_bytes;
7691 	if (r_rsm->r_in_tmap) {
7692 		/* This really should not happen */
7693 		TAILQ_REMOVE(&rack->r_ctl.rc_tmap, r_rsm, r_tnext);
7694 		r_rsm->r_in_tmap = 0;
7695 	}
7696 
7697 	/* Now the flags */
7698 	if (r_rsm->r_flags & RACK_HAS_FIN)
7699 		l_rsm->r_flags |= RACK_HAS_FIN;
7700 	if (r_rsm->r_flags & RACK_TLP)
7701 		l_rsm->r_flags |= RACK_TLP;
7702 	if (r_rsm->r_flags & RACK_RWND_COLLAPSED)
7703 		l_rsm->r_flags |= RACK_RWND_COLLAPSED;
7704 	if ((r_rsm->r_flags & RACK_APP_LIMITED)  &&
7705 	    ((l_rsm->r_flags & RACK_APP_LIMITED) == 0)) {
7706 		/*
7707 		 * If both are app-limited then let the
7708 		 * free lower the count. If right is app
7709 		 * limited and left is not, transfer.
7710 		 */
7711 		l_rsm->r_flags |= RACK_APP_LIMITED;
7712 		r_rsm->r_flags &= ~RACK_APP_LIMITED;
7713 		if (r_rsm == rack->r_ctl.rc_first_appl)
7714 			rack->r_ctl.rc_first_appl = l_rsm;
7715 	}
7716 	tqhash_remove(rack->r_ctl.tqh, r_rsm, REMOVE_TYPE_MERGE);
7717 	/*
7718 	 * We keep the largest value, which is the newest
7719 	 * send. We do this in case a segment that is
7720 	 * joined together and not part of a GP estimate
7721 	 * later gets expanded into the GP estimate.
7722 	 *
7723 	 * We prohibit the merging of unlike kinds i.e.
7724 	 * all pieces that are in the GP estimate can be
7725 	 * merged and all pieces that are not in a GP estimate
7726 	 * can be merged, but not disimilar pieces. Combine
7727 	 * this with taking the highest here and we should
7728 	 * be ok unless of course the client reneges. Then
7729 	 * all bets are off.
7730 	 */
7731 	if(l_rsm->r_tim_lastsent[(l_rsm->r_rtr_cnt-1)] <
7732 	   r_rsm->r_tim_lastsent[(r_rsm->r_rtr_cnt-1)]) {
7733 		l_rsm->r_tim_lastsent[(l_rsm->r_rtr_cnt-1)] = r_rsm->r_tim_lastsent[(r_rsm->r_rtr_cnt-1)];
7734 	}
7735 	/*
7736 	 * When merging two RSM's we also need to consider the ack time and keep
7737 	 * newest. If the ack gets merged into a measurement then that is the
7738 	 * one we will want to be using.
7739 	 */
7740 	if(l_rsm->r_ack_arrival	 < r_rsm->r_ack_arrival)
7741 		l_rsm->r_ack_arrival = r_rsm->r_ack_arrival;
7742 
7743 	if ((r_rsm->r_limit_type == 0) && (l_rsm->r_limit_type != 0)) {
7744 		/* Transfer the split limit to the map we free */
7745 		r_rsm->r_limit_type = l_rsm->r_limit_type;
7746 		l_rsm->r_limit_type = 0;
7747 	}
7748 	rack_free(rack, r_rsm);
7749 	l_rsm->r_flags |= RACK_MERGED;
7750 	return (l_rsm);
7751 }
7752 
7753 /*
7754  * TLP Timer, here we simply setup what segment we want to
7755  * have the TLP expire on, the normal rack_output() will then
7756  * send it out.
7757  *
7758  * We return 1, saying don't proceed with rack_output only
7759  * when all timers have been stopped (destroyed PCB?).
7760  */
7761 static int
rack_timeout_tlp(struct tcpcb * tp,struct tcp_rack * rack,uint32_t cts,uint8_t * doing_tlp)7762 rack_timeout_tlp(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t *doing_tlp)
7763 {
7764 	/*
7765 	 * Tail Loss Probe.
7766 	 */
7767 	struct rack_sendmap *rsm = NULL;
7768 	int insret __diagused;
7769 	struct socket *so = tptosocket(tp);
7770 	uint32_t amm;
7771 	uint32_t out, avail;
7772 	int collapsed_win = 0;
7773 
7774 	if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
7775 		/* Its not time yet */
7776 		return (0);
7777 	}
7778 	if (ctf_progress_timeout_check(tp, true)) {
7779 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
7780 		return (-ETIMEDOUT);	/* tcp_drop() */
7781 	}
7782 	/*
7783 	 * A TLP timer has expired. We have been idle for 2 rtts. So we now
7784 	 * need to figure out how to force a full MSS segment out.
7785 	 */
7786 	rack_log_to_event(rack, RACK_TO_FRM_TLP, NULL);
7787 	rack->r_ctl.retran_during_recovery = 0;
7788 	rack->r_might_revert = 0;
7789 	rack->r_ctl.dsack_byte_cnt = 0;
7790 	counter_u64_add(rack_tlp_tot, 1);
7791 	if (rack->r_state && (rack->r_state != tp->t_state))
7792 		rack_set_state(tp, rack);
7793 	avail = sbavail(&so->so_snd);
7794 	out = tp->snd_max - tp->snd_una;
7795 	if ((out > tp->snd_wnd) || rack->rc_has_collapsed) {
7796 		/* special case, we need a retransmission */
7797 		collapsed_win = 1;
7798 		goto need_retran;
7799 	}
7800 	if (rack->r_ctl.dsack_persist && (rack->r_ctl.rc_tlp_cnt_out >= 1)) {
7801 		rack->r_ctl.dsack_persist--;
7802 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
7803 			rack->r_ctl.num_dsack = 0;
7804 		}
7805 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
7806 	}
7807 	if ((tp->t_flags & TF_GPUTINPROG) &&
7808 	    (rack->r_ctl.rc_tlp_cnt_out == 1)) {
7809 		/*
7810 		 * If this is the second in a row
7811 		 * TLP and we are doing a measurement
7812 		 * its time to abandon the measurement.
7813 		 * Something is likely broken on
7814 		 * the clients network and measuring a
7815 		 * broken network does us no good.
7816 		 */
7817 		tp->t_flags &= ~TF_GPUTINPROG;
7818 		rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
7819 					   rack->r_ctl.rc_gp_srtt /*flex1*/,
7820 					   tp->gput_seq,
7821 					   0, 0, 18, __LINE__, NULL, 0);
7822 	}
7823 	/*
7824 	 * Check our send oldest always settings, and if
7825 	 * there is an oldest to send jump to the need_retran.
7826 	 */
7827 	if (rack_always_send_oldest && (TAILQ_EMPTY(&rack->r_ctl.rc_tmap) == 0))
7828 		goto need_retran;
7829 
7830 	if (avail > out) {
7831 		/* New data is available */
7832 		amm = avail - out;
7833 		if (amm > ctf_fixed_maxseg(tp)) {
7834 			amm = ctf_fixed_maxseg(tp);
7835 			if ((amm + out) > tp->snd_wnd) {
7836 				/* We are rwnd limited */
7837 				goto need_retran;
7838 			}
7839 		} else if (amm < ctf_fixed_maxseg(tp)) {
7840 			/* not enough to fill a MTU */
7841 			goto need_retran;
7842 		}
7843 		if (IN_FASTRECOVERY(tp->t_flags)) {
7844 			/* Unlikely */
7845 			if (rack->rack_no_prr == 0) {
7846 				if (out + amm <= tp->snd_wnd) {
7847 					rack->r_ctl.rc_prr_sndcnt = amm;
7848 					rack->r_ctl.rc_tlp_new_data = amm;
7849 					rack_log_to_prr(rack, 4, 0, __LINE__);
7850 				}
7851 			} else
7852 				goto need_retran;
7853 		} else {
7854 			/* Set the send-new override */
7855 			if (out + amm <= tp->snd_wnd)
7856 				rack->r_ctl.rc_tlp_new_data = amm;
7857 			else
7858 				goto need_retran;
7859 		}
7860 		rack->r_ctl.rc_tlpsend = NULL;
7861 		counter_u64_add(rack_tlp_newdata, 1);
7862 		goto send;
7863 	}
7864 need_retran:
7865 	/*
7866 	 * Ok we need to arrange the last un-acked segment to be re-sent, or
7867 	 * optionally the first un-acked segment.
7868 	 */
7869 	if (collapsed_win == 0) {
7870 		if (rack_always_send_oldest)
7871 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
7872 		else {
7873 			rsm = tqhash_max(rack->r_ctl.tqh);
7874 			if (rsm && (rsm->r_flags & (RACK_ACKED | RACK_HAS_FIN))) {
7875 				rsm = rack_find_high_nonack(rack, rsm);
7876 			}
7877 		}
7878 		if (rsm == NULL) {
7879 #ifdef TCP_BLACKBOX
7880 			tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
7881 #endif
7882 			goto out;
7883 		}
7884 	} else {
7885 		/*
7886 		 * We had a collapsed window, lets find
7887 		 * the point before the collapse.
7888 		 */
7889 		if (SEQ_GT((rack->r_ctl.last_collapse_point - 1), rack->rc_tp->snd_una))
7890 			rsm = tqhash_find(rack->r_ctl.tqh, (rack->r_ctl.last_collapse_point - 1));
7891 		else {
7892 			rsm = tqhash_min(rack->r_ctl.tqh);
7893 		}
7894 		if (rsm == NULL) {
7895 			/* Huh */
7896 			goto out;
7897 		}
7898 	}
7899 	if ((rsm->r_end - rsm->r_start) > ctf_fixed_maxseg(tp)) {
7900 		/*
7901 		 * We need to split this the last segment in two.
7902 		 */
7903 		struct rack_sendmap *nrsm;
7904 
7905 		nrsm = rack_alloc_full_limit(rack);
7906 		if (nrsm == NULL) {
7907 			/*
7908 			 * No memory to split, we will just exit and punt
7909 			 * off to the RXT timer.
7910 			 */
7911 			goto out;
7912 		}
7913 		rack_clone_rsm(rack, nrsm, rsm,
7914 			       (rsm->r_end - ctf_fixed_maxseg(tp)));
7915 		rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
7916 #ifndef INVARIANTS
7917 		(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
7918 #else
7919 		if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
7920 			panic("Insert in tailq_hash of %p fails ret:%d rack:%p rsm:%p",
7921 			      nrsm, insret, rack, rsm);
7922 		}
7923 #endif
7924 		if (rsm->r_in_tmap) {
7925 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7926 			nrsm->r_in_tmap = 1;
7927 		}
7928 		rsm = nrsm;
7929 	}
7930 	rack->r_ctl.rc_tlpsend = rsm;
7931 send:
7932 	/* Make sure output path knows we are doing a TLP */
7933 	*doing_tlp = 1;
7934 	rack->r_timer_override = 1;
7935 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
7936 	return (0);
7937 out:
7938 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
7939 	return (0);
7940 }
7941 
7942 /*
7943  * Delayed ack Timer, here we simply need to setup the
7944  * ACK_NOW flag and remove the DELACK flag. From there
7945  * the output routine will send the ack out.
7946  *
7947  * We only return 1, saying don't proceed, if all timers
7948  * are stopped (destroyed PCB?).
7949  */
7950 static int
rack_timeout_delack(struct tcpcb * tp,struct tcp_rack * rack,uint32_t cts)7951 rack_timeout_delack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
7952 {
7953 
7954 	rack_log_to_event(rack, RACK_TO_FRM_DELACK, NULL);
7955 	tp->t_flags &= ~TF_DELACK;
7956 	tp->t_flags |= TF_ACKNOW;
7957 	KMOD_TCPSTAT_INC(tcps_delack);
7958 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
7959 	return (0);
7960 }
7961 
7962 static inline int
rack_send_ack_challange(struct tcp_rack * rack)7963 rack_send_ack_challange(struct tcp_rack *rack)
7964 {
7965 	struct tcptemp *t_template;
7966 
7967 	t_template = tcpip_maketemplate(rack->rc_inp);
7968 	if (t_template) {
7969 		if (rack->forced_ack == 0) {
7970 			rack->forced_ack = 1;
7971 			rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
7972 		} else {
7973 			rack->probe_not_answered = 1;
7974 		}
7975 		tcp_respond(rack->rc_tp, t_template->tt_ipgen,
7976 			    &t_template->tt_t, (struct mbuf *)NULL,
7977 			    rack->rc_tp->rcv_nxt, rack->rc_tp->snd_una - 1, 0);
7978 		free(t_template, M_TEMP);
7979 		/* This does send an ack so kill any D-ack timer */
7980 		if (rack->rc_tp->t_flags & TF_DELACK)
7981 			rack->rc_tp->t_flags &= ~TF_DELACK;
7982 		return(1);
7983 	} else
7984 		return (0);
7985 
7986 }
7987 
7988 /*
7989  * Persists timer, here we simply send the
7990  * same thing as a keepalive will.
7991  * the one byte send.
7992  *
7993  * We only return 1, saying don't proceed, if all timers
7994  * are stopped (destroyed PCB?).
7995  */
7996 static int
rack_timeout_persist(struct tcpcb * tp,struct tcp_rack * rack,uint32_t cts)7997 rack_timeout_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
7998 {
7999 	int32_t retval = 1;
8000 
8001 	if (rack->rc_in_persist == 0)
8002 		return (0);
8003 	if (ctf_progress_timeout_check(tp, false)) {
8004 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
8005 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
8006 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
8007 		return (-ETIMEDOUT);	/* tcp_drop() */
8008 	}
8009 	/*
8010 	 * Persistence timer into zero window. Force a byte to be output, if
8011 	 * possible.
8012 	 */
8013 	KMOD_TCPSTAT_INC(tcps_persisttimeo);
8014 	/*
8015 	 * Hack: if the peer is dead/unreachable, we do not time out if the
8016 	 * window is closed.  After a full backoff, drop the connection if
8017 	 * the idle time (no responses to probes) reaches the maximum
8018 	 * backoff that we would use if retransmitting.
8019 	 */
8020 	if (tp->t_rxtshift >= V_tcp_retries &&
8021 	    (ticks - tp->t_rcvtime >= tcp_maxpersistidle ||
8022 	     TICKS_2_USEC(ticks - tp->t_rcvtime) >= RACK_REXMTVAL(tp) * tcp_totbackoff)) {
8023 		KMOD_TCPSTAT_INC(tcps_persistdrop);
8024 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
8025 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
8026 		retval = -ETIMEDOUT;	/* tcp_drop() */
8027 		goto out;
8028 	}
8029 	if ((sbavail(&rack->rc_inp->inp_socket->so_snd) == 0) &&
8030 	    tp->snd_una == tp->snd_max)
8031 		rack_exit_persist(tp, rack, cts);
8032 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_PERSIT;
8033 	/*
8034 	 * If the user has closed the socket then drop a persisting
8035 	 * connection after a much reduced timeout.
8036 	 */
8037 	if (tp->t_state > TCPS_CLOSE_WAIT &&
8038 	    (ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) {
8039 		KMOD_TCPSTAT_INC(tcps_persistdrop);
8040 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
8041 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
8042 		retval = -ETIMEDOUT;	/* tcp_drop() */
8043 		goto out;
8044 	}
8045 	if (rack_send_ack_challange(rack)) {
8046 		/* only set it if we were answered */
8047 		if (rack->probe_not_answered) {
8048 			counter_u64_add(rack_persists_loss, 1);
8049 			rack->r_ctl.persist_lost_ends++;
8050 		}
8051 		counter_u64_add(rack_persists_sends, 1);
8052 		counter_u64_add(rack_out_size[TCP_MSS_ACCT_PERSIST], 1);
8053 	}
8054 	if (tp->t_rxtshift < V_tcp_retries)
8055 		tp->t_rxtshift++;
8056 out:
8057 	rack_log_to_event(rack, RACK_TO_FRM_PERSIST, NULL);
8058 	rack_start_hpts_timer(rack, tp, cts,
8059 			      0, 0, 0);
8060 	return (retval);
8061 }
8062 
8063 /*
8064  * If a keepalive goes off, we had no other timers
8065  * happening. We always return 1 here since this
8066  * routine either drops the connection or sends
8067  * out a segment with respond.
8068  */
8069 static int
rack_timeout_keepalive(struct tcpcb * tp,struct tcp_rack * rack,uint32_t cts)8070 rack_timeout_keepalive(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
8071 {
8072 	struct inpcb *inp = tptoinpcb(tp);
8073 
8074 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_KEEP;
8075 	rack_log_to_event(rack, RACK_TO_FRM_KEEP, NULL);
8076 	/*
8077 	 * Keep-alive timer went off; send something or drop connection if
8078 	 * idle for too long.
8079 	 */
8080 	KMOD_TCPSTAT_INC(tcps_keeptimeo);
8081 	if (tp->t_state < TCPS_ESTABLISHED)
8082 		goto dropit;
8083 	if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
8084 	    tp->t_state <= TCPS_CLOSING) {
8085 		if (ticks - tp->t_rcvtime >= TP_KEEPIDLE(tp) + TP_MAXIDLE(tp))
8086 			goto dropit;
8087 		/*
8088 		 * Send a packet designed to force a response if the peer is
8089 		 * up and reachable: either an ACK if the connection is
8090 		 * still alive, or an RST if the peer has closed the
8091 		 * connection due to timeout or reboot. Using sequence
8092 		 * number tp->snd_una-1 causes the transmitted zero-length
8093 		 * segment to lie outside the receive window; by the
8094 		 * protocol spec, this requires the correspondent TCP to
8095 		 * respond.
8096 		 */
8097 		KMOD_TCPSTAT_INC(tcps_keepprobe);
8098 		rack_send_ack_challange(rack);
8099 	}
8100 	rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
8101 	return (1);
8102 dropit:
8103 	KMOD_TCPSTAT_INC(tcps_keepdrops);
8104 	tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
8105 	return (-ETIMEDOUT);	/* tcp_drop() */
8106 }
8107 
8108 /*
8109  * Retransmit helper function, clear up all the ack
8110  * flags and take care of important book keeping.
8111  */
8112 static void
rack_remxt_tmr(struct tcpcb * tp)8113 rack_remxt_tmr(struct tcpcb *tp)
8114 {
8115 	/*
8116 	 * The retransmit timer went off, all sack'd blocks must be
8117 	 * un-acked.
8118 	 */
8119 	struct rack_sendmap *rsm, *trsm = NULL;
8120 	struct tcp_rack *rack;
8121 
8122 	rack = (struct tcp_rack *)tp->t_fb_ptr;
8123 	rack_timer_cancel(tp, rack, tcp_get_usecs(NULL), __LINE__);
8124 	rack_log_to_event(rack, RACK_TO_FRM_TMR, NULL);
8125 	rack->r_timer_override = 1;
8126 	rack->r_ctl.rc_snd_max_at_rto = tp->snd_max;
8127 	rack->r_ctl.rc_last_timeout_snduna = tp->snd_una;
8128 	rack->r_late = 0;
8129 	rack->r_early = 0;
8130 	rack->r_ctl.rc_agg_delayed = 0;
8131 	rack->r_ctl.rc_agg_early = 0;
8132 	if (rack->r_state && (rack->r_state != tp->t_state))
8133 		rack_set_state(tp, rack);
8134 	if (tp->t_rxtshift <= rack_rxt_scoreboard_clear_thresh) {
8135 		/*
8136 		 * We do not clear the scoreboard until we have had
8137 		 * more than rack_rxt_scoreboard_clear_thresh time-outs.
8138 		 */
8139 		rack->r_ctl.rc_resend = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
8140 		if (rack->r_ctl.rc_resend != NULL)
8141 			rack->r_ctl.rc_resend->r_flags |= RACK_TO_REXT;
8142 
8143 		return;
8144 	}
8145 	/*
8146 	 * Ideally we would like to be able to
8147 	 * mark SACK-PASS on anything not acked here.
8148 	 *
8149 	 * However, if we do that we would burst out
8150 	 * all that data 1ms apart. This would be unwise,
8151 	 * so for now we will just let the normal rxt timer
8152 	 * and tlp timer take care of it.
8153 	 *
8154 	 * Also we really need to stick them back in sequence
8155 	 * order. This way we send in the proper order and any
8156 	 * sacks that come floating in will "re-ack" the data.
8157 	 * To do this we zap the tmap with an INIT and then
8158 	 * walk through and place every rsm in the tail queue
8159 	 * hash table back in its seq ordered place.
8160 	 */
8161 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
8162 
8163 	TQHASH_FOREACH(rsm, rack->r_ctl.tqh)  {
8164 		rsm->r_dupack = 0;
8165 		if (rack_verbose_logging)
8166 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
8167 		/* We must re-add it back to the tlist */
8168 		if (trsm == NULL) {
8169 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8170 		} else {
8171 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, trsm, rsm, r_tnext);
8172 		}
8173 		rsm->r_in_tmap = 1;
8174 		trsm = rsm;
8175 		if (rsm->r_flags & RACK_ACKED)
8176 			rsm->r_flags |= RACK_WAS_ACKED;
8177 		rsm->r_flags &= ~(RACK_ACKED | RACK_SACK_PASSED | RACK_WAS_SACKPASS | RACK_RWND_COLLAPSED | RACK_WAS_LOST);
8178 		rsm->r_flags |= RACK_MUST_RXT;
8179 	}
8180 	/* zero the lost since it's all gone */
8181 	rack->r_ctl.rc_considered_lost = 0;
8182 	/* Clear the count (we just un-acked them) */
8183 	rack->r_ctl.rc_sacked = 0;
8184 	rack->r_ctl.rc_sacklast = NULL;
8185 	/* Clear the tlp rtx mark */
8186 	rack->r_ctl.rc_resend = tqhash_min(rack->r_ctl.tqh);
8187 	if (rack->r_ctl.rc_resend != NULL)
8188 		rack->r_ctl.rc_resend->r_flags |= RACK_TO_REXT;
8189 	rack->r_ctl.rc_prr_sndcnt = 0;
8190 	rack_log_to_prr(rack, 6, 0, __LINE__);
8191 	rack->r_ctl.rc_resend = tqhash_min(rack->r_ctl.tqh);
8192 	if (rack->r_ctl.rc_resend != NULL)
8193 		rack->r_ctl.rc_resend->r_flags |= RACK_TO_REXT;
8194 	if (((tp->t_flags & TF_SACK_PERMIT) == 0) &&
8195 	    ((tp->t_flags & TF_SENTFIN) == 0)) {
8196 		/*
8197 		 * For non-sack customers new data
8198 		 * needs to go out as retransmits until
8199 		 * we retransmit up to snd_max.
8200 		 */
8201 		rack->r_must_retran = 1;
8202 		rack->r_ctl.rc_out_at_rto = ctf_flight_size(rack->rc_tp,
8203 							    rack->r_ctl.rc_sacked);
8204 	}
8205 }
8206 
8207 static void
rack_convert_rtts(struct tcpcb * tp)8208 rack_convert_rtts(struct tcpcb *tp)
8209 {
8210 	tcp_change_time_units(tp, TCP_TMR_GRANULARITY_USEC);
8211 	tp->t_rxtcur = RACK_REXMTVAL(tp);
8212 	if (TCPS_HAVEESTABLISHED(tp->t_state)) {
8213 		tp->t_rxtcur += TICKS_2_USEC(tcp_rexmit_slop);
8214 	}
8215 	if (tp->t_rxtcur > rack_rto_max) {
8216 		tp->t_rxtcur = rack_rto_max;
8217 	}
8218 }
8219 
8220 static void
rack_cc_conn_init(struct tcpcb * tp)8221 rack_cc_conn_init(struct tcpcb *tp)
8222 {
8223 	struct tcp_rack *rack;
8224 	uint32_t srtt;
8225 
8226 	rack = (struct tcp_rack *)tp->t_fb_ptr;
8227 	srtt = tp->t_srtt;
8228 	cc_conn_init(tp);
8229 	/*
8230 	 * Now convert to rack's internal format,
8231 	 * if required.
8232 	 */
8233 	if ((srtt == 0) && (tp->t_srtt != 0))
8234 		rack_convert_rtts(tp);
8235 	/*
8236 	 * We want a chance to stay in slowstart as
8237 	 * we create a connection. TCP spec says that
8238 	 * initially ssthresh is infinite. For our
8239 	 * purposes that is the snd_wnd.
8240 	 */
8241 	if (tp->snd_ssthresh < tp->snd_wnd) {
8242 		tp->snd_ssthresh = tp->snd_wnd;
8243 	}
8244 	/*
8245 	 * We also want to assure a IW worth of
8246 	 * data can get inflight.
8247 	 */
8248 	if (rc_init_window(rack) < tp->snd_cwnd)
8249 		tp->snd_cwnd = rc_init_window(rack);
8250 }
8251 
8252 /*
8253  * Re-transmit timeout! If we drop the PCB we will return 1, otherwise
8254  * we will setup to retransmit the lowest seq number outstanding.
8255  */
8256 static int
rack_timeout_rxt(struct tcpcb * tp,struct tcp_rack * rack,uint32_t cts)8257 rack_timeout_rxt(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
8258 {
8259 	struct inpcb *inp = tptoinpcb(tp);
8260 	int32_t rexmt;
8261 	int32_t retval = 0;
8262 	bool isipv6;
8263 
8264 	if ((tp->t_flags & TF_GPUTINPROG) &&
8265 	    (tp->t_rxtshift)) {
8266 		/*
8267 		 * We have had a second timeout
8268 		 * measurements on successive rxt's are not profitable.
8269 		 * It is unlikely to be of any use (the network is
8270 		 * broken or the client went away).
8271 		 */
8272 		tp->t_flags &= ~TF_GPUTINPROG;
8273 		rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
8274 					   rack->r_ctl.rc_gp_srtt /*flex1*/,
8275 					   tp->gput_seq,
8276 					   0, 0, 18, __LINE__, NULL, 0);
8277 	}
8278 	if (ctf_progress_timeout_check(tp, false)) {
8279 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
8280 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
8281 		return (-ETIMEDOUT);	/* tcp_drop() */
8282 	}
8283 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RXT;
8284 	rack->r_ctl.retran_during_recovery = 0;
8285 	rack->rc_ack_required = 1;
8286 	rack->r_ctl.dsack_byte_cnt = 0;
8287 	if (IN_RECOVERY(tp->t_flags) &&
8288 	    (rack->rto_from_rec == 0)) {
8289 		/*
8290 		 * Mark that we had a rto while in recovery
8291 		 * and save the ssthresh so if we go back
8292 		 * into recovery we will have a chance
8293 		 * to slowstart back to the level.
8294 		 */
8295 		rack->rto_from_rec = 1;
8296 		rack->r_ctl.rto_ssthresh = tp->snd_ssthresh;
8297 	}
8298 	if (IN_FASTRECOVERY(tp->t_flags))
8299 		tp->t_flags |= TF_WASFRECOVERY;
8300 	else
8301 		tp->t_flags &= ~TF_WASFRECOVERY;
8302 	if (IN_CONGRECOVERY(tp->t_flags))
8303 		tp->t_flags |= TF_WASCRECOVERY;
8304 	else
8305 		tp->t_flags &= ~TF_WASCRECOVERY;
8306 	if (TCPS_HAVEESTABLISHED(tp->t_state) &&
8307 	    (tp->snd_una == tp->snd_max)) {
8308 		/* Nothing outstanding .. nothing to do */
8309 		return (0);
8310 	}
8311 	if (rack->r_ctl.dsack_persist) {
8312 		rack->r_ctl.dsack_persist--;
8313 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
8314 			rack->r_ctl.num_dsack = 0;
8315 		}
8316 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
8317 	}
8318 	/*
8319 	 * Rack can only run one timer  at a time, so we cannot
8320 	 * run a KEEPINIT (gating SYN sending) and a retransmit
8321 	 * timer for the SYN. So if we are in a front state and
8322 	 * have a KEEPINIT timer we need to check the first transmit
8323 	 * against now to see if we have exceeded the KEEPINIT time
8324 	 * (if one is set).
8325 	 */
8326 	if ((TCPS_HAVEESTABLISHED(tp->t_state) == 0) &&
8327 	    (TP_KEEPINIT(tp) != 0)) {
8328 		struct rack_sendmap *rsm;
8329 
8330 		rsm = tqhash_min(rack->r_ctl.tqh);
8331 		if (rsm) {
8332 			/* Ok we have something outstanding to test keepinit with */
8333 			if ((TSTMP_GT(cts, (uint32_t)rsm->r_tim_lastsent[0])) &&
8334 			    ((cts - (uint32_t)rsm->r_tim_lastsent[0]) >= TICKS_2_USEC(TP_KEEPINIT(tp)))) {
8335 				/* We have exceeded the KEEPINIT time */
8336 				tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
8337 				goto drop_it;
8338 			}
8339 		}
8340 	}
8341 	/*
8342 	 * Retransmission timer went off.  Message has not been acked within
8343 	 * retransmit interval.  Back off to a longer retransmit interval
8344 	 * and retransmit one segment.
8345 	 */
8346 	if ((rack->r_ctl.rc_resend == NULL) ||
8347 	    ((rack->r_ctl.rc_resend->r_flags & RACK_RWND_COLLAPSED) == 0)) {
8348 		/*
8349 		 * If the rwnd collapsed on
8350 		 * the one we are retransmitting
8351 		 * it does not count against the
8352 		 * rxt count.
8353 		 */
8354 		tp->t_rxtshift++;
8355 	}
8356 	rack_remxt_tmr(tp);
8357 	if (tp->t_rxtshift > V_tcp_retries) {
8358 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
8359 drop_it:
8360 		tp->t_rxtshift = V_tcp_retries;
8361 		KMOD_TCPSTAT_INC(tcps_timeoutdrop);
8362 		/* XXXGL: previously t_softerror was casted to uint16_t */
8363 		MPASS(tp->t_softerror >= 0);
8364 		retval = tp->t_softerror ? -tp->t_softerror : -ETIMEDOUT;
8365 		goto out;	/* tcp_drop() */
8366 	}
8367 	if (tp->t_state == TCPS_SYN_SENT) {
8368 		/*
8369 		 * If the SYN was retransmitted, indicate CWND to be limited
8370 		 * to 1 segment in cc_conn_init().
8371 		 */
8372 		tp->snd_cwnd = 1;
8373 	} else if (tp->t_rxtshift == 1) {
8374 		/*
8375 		 * first retransmit; record ssthresh and cwnd so they can be
8376 		 * recovered if this turns out to be a "bad" retransmit. A
8377 		 * retransmit is considered "bad" if an ACK for this segment
8378 		 * is received within RTT/2 interval; the assumption here is
8379 		 * that the ACK was already in flight.  See "On Estimating
8380 		 * End-to-End Network Path Properties" by Allman and Paxson
8381 		 * for more details.
8382 		 */
8383 		tp->snd_cwnd_prev = tp->snd_cwnd;
8384 		tp->snd_ssthresh_prev = tp->snd_ssthresh;
8385 		tp->snd_recover_prev = tp->snd_recover;
8386 		tp->t_badrxtwin = ticks + (USEC_2_TICKS(tp->t_srtt)/2);
8387 		tp->t_flags |= TF_PREVVALID;
8388 	} else if ((tp->t_flags & TF_RCVD_TSTMP) == 0)
8389 		tp->t_flags &= ~TF_PREVVALID;
8390 	KMOD_TCPSTAT_INC(tcps_rexmttimeo);
8391 	if ((tp->t_state == TCPS_SYN_SENT) ||
8392 	    (tp->t_state == TCPS_SYN_RECEIVED))
8393 		rexmt = RACK_INITIAL_RTO * tcp_backoff[tp->t_rxtshift];
8394 	else
8395 		rexmt = max(rack_rto_min, (tp->t_srtt + (tp->t_rttvar << 2))) * tcp_backoff[tp->t_rxtshift];
8396 
8397 	RACK_TCPT_RANGESET(tp->t_rxtcur, rexmt,
8398 	   max(rack_rto_min, rexmt), rack_rto_max, rack->r_ctl.timer_slop);
8399 	/*
8400 	 * We enter the path for PLMTUD if connection is established or, if
8401 	 * connection is FIN_WAIT_1 status, reason for the last is that if
8402 	 * amount of data we send is very small, we could send it in couple
8403 	 * of packets and process straight to FIN. In that case we won't
8404 	 * catch ESTABLISHED state.
8405 	 */
8406 #ifdef INET6
8407 	isipv6 = (inp->inp_vflag & INP_IPV6) ? true : false;
8408 #else
8409 	isipv6 = false;
8410 #endif
8411 	if (((V_tcp_pmtud_blackhole_detect == 1) ||
8412 	    (V_tcp_pmtud_blackhole_detect == 2 && !isipv6) ||
8413 	    (V_tcp_pmtud_blackhole_detect == 3 && isipv6)) &&
8414 	    ((tp->t_state == TCPS_ESTABLISHED) ||
8415 	    (tp->t_state == TCPS_FIN_WAIT_1))) {
8416 		/*
8417 		 * Idea here is that at each stage of mtu probe (usually,
8418 		 * 1448 -> 1188 -> 524) should be given 2 chances to recover
8419 		 * before further clamping down. 'tp->t_rxtshift % 2 == 0'
8420 		 * should take care of that.
8421 		 */
8422 		if (((tp->t_flags2 & (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) ==
8423 		    (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) &&
8424 		    (tp->t_rxtshift >= 2 && tp->t_rxtshift < 6 &&
8425 		    tp->t_rxtshift % 2 == 0)) {
8426 			/*
8427 			 * Enter Path MTU Black-hole Detection mechanism: -
8428 			 * Disable Path MTU Discovery (IP "DF" bit). -
8429 			 * Reduce MTU to lower value than what we negotiated
8430 			 * with peer.
8431 			 */
8432 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) == 0) {
8433 				/* Record that we may have found a black hole. */
8434 				tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE;
8435 				/* Keep track of previous MSS. */
8436 				tp->t_pmtud_saved_maxseg = tp->t_maxseg;
8437 			}
8438 
8439 			/*
8440 			 * Reduce the MSS to blackhole value or to the
8441 			 * default in an attempt to retransmit.
8442 			 */
8443 #ifdef INET6
8444 			if (isipv6 &&
8445 			    tp->t_maxseg > V_tcp_v6pmtud_blackhole_mss) {
8446 				/* Use the sysctl tuneable blackhole MSS. */
8447 				tp->t_maxseg = V_tcp_v6pmtud_blackhole_mss;
8448 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
8449 			} else if (isipv6) {
8450 				/* Use the default MSS. */
8451 				tp->t_maxseg = V_tcp_v6mssdflt;
8452 				/*
8453 				 * Disable Path MTU Discovery when we switch
8454 				 * to minmss.
8455 				 */
8456 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
8457 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
8458 			}
8459 #endif
8460 #if defined(INET6) && defined(INET)
8461 			else
8462 #endif
8463 #ifdef INET
8464 			if (tp->t_maxseg > V_tcp_pmtud_blackhole_mss) {
8465 				/* Use the sysctl tuneable blackhole MSS. */
8466 				tp->t_maxseg = V_tcp_pmtud_blackhole_mss;
8467 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
8468 			} else {
8469 				/* Use the default MSS. */
8470 				tp->t_maxseg = V_tcp_mssdflt;
8471 				/*
8472 				 * Disable Path MTU Discovery when we switch
8473 				 * to minmss.
8474 				 */
8475 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
8476 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
8477 			}
8478 #endif
8479 		} else {
8480 			/*
8481 			 * If further retransmissions are still unsuccessful
8482 			 * with a lowered MTU, maybe this isn't a blackhole
8483 			 * and we restore the previous MSS and blackhole
8484 			 * detection flags. The limit '6' is determined by
8485 			 * giving each probe stage (1448, 1188, 524) 2
8486 			 * chances to recover.
8487 			 */
8488 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) &&
8489 			    (tp->t_rxtshift >= 6)) {
8490 				tp->t_flags2 |= TF2_PLPMTU_PMTUD;
8491 				tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE;
8492 				tp->t_maxseg = tp->t_pmtud_saved_maxseg;
8493 				if (tp->t_maxseg < V_tcp_mssdflt) {
8494 					/*
8495 					 * The MSS is so small we should not
8496 					 * process incoming SACK's since we are
8497 					 * subject to attack in such a case.
8498 					 */
8499 					tp->t_flags2 |= TF2_PROC_SACK_PROHIBIT;
8500 				} else {
8501 					tp->t_flags2 &= ~TF2_PROC_SACK_PROHIBIT;
8502 				}
8503 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_failed);
8504 			}
8505 		}
8506 	}
8507 	/*
8508 	 * Disable RFC1323 and SACK if we haven't got any response to
8509 	 * our third SYN to work-around some broken terminal servers
8510 	 * (most of which have hopefully been retired) that have bad VJ
8511 	 * header compression code which trashes TCP segments containing
8512 	 * unknown-to-them TCP options.
8513 	 */
8514 	if (tcp_rexmit_drop_options && (tp->t_state == TCPS_SYN_SENT) &&
8515 	    (tp->t_rxtshift == 3))
8516 		tp->t_flags &= ~(TF_REQ_SCALE|TF_REQ_TSTMP|TF_SACK_PERMIT);
8517 	/*
8518 	 * If we backed off this far, our srtt estimate is probably bogus.
8519 	 * Clobber it so we'll take the next rtt measurement as our srtt;
8520 	 * move the current srtt into rttvar to keep the current retransmit
8521 	 * times until then.
8522 	 */
8523 	if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
8524 #ifdef INET6
8525 		if ((inp->inp_vflag & INP_IPV6) != 0)
8526 			in6_losing(inp);
8527 		else
8528 #endif
8529 			in_losing(inp);
8530 		tp->t_rttvar += tp->t_srtt;
8531 		tp->t_srtt = 0;
8532 	}
8533 	sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
8534 	tp->snd_recover = tp->snd_max;
8535 	tp->t_flags |= TF_ACKNOW;
8536 	tp->t_rtttime = 0;
8537 	rack_cong_signal(tp, CC_RTO, tp->snd_una, __LINE__);
8538 out:
8539 	return (retval);
8540 }
8541 
8542 static int
rack_process_timers(struct tcpcb * tp,struct tcp_rack * rack,uint32_t cts,uint8_t hpts_calling,uint8_t * doing_tlp)8543 rack_process_timers(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t hpts_calling, uint8_t *doing_tlp)
8544 {
8545 	int32_t ret = 0;
8546 	int32_t timers = (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK);
8547 
8548 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
8549 	    (tp->t_flags & TF_GPUTINPROG)) {
8550 		/*
8551 		 * We have a goodput in progress
8552 		 * and we have entered a late state.
8553 		 * Do we have enough data in the sb
8554 		 * to handle the GPUT request?
8555 		 */
8556 		uint32_t bytes;
8557 
8558 		bytes = tp->gput_ack - tp->gput_seq;
8559 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
8560 			bytes += tp->gput_seq - tp->snd_una;
8561 		if (bytes > sbavail(&tptosocket(tp)->so_snd)) {
8562 			/*
8563 			 * There are not enough bytes in the socket
8564 			 * buffer that have been sent to cover this
8565 			 * measurement. Cancel it.
8566 			 */
8567 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
8568 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
8569 						   tp->gput_seq,
8570 						   0, 0, 18, __LINE__, NULL, 0);
8571 			tp->t_flags &= ~TF_GPUTINPROG;
8572 		}
8573 	}
8574 	if (timers == 0) {
8575 		return (0);
8576 	}
8577 	if (tp->t_state == TCPS_LISTEN) {
8578 		/* no timers on listen sockets */
8579 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)
8580 			return (0);
8581 		return (1);
8582 	}
8583 	if ((timers & PACE_TMR_RACK) &&
8584 	    rack->rc_on_min_to) {
8585 		/*
8586 		 * For the rack timer when we
8587 		 * are on a min-timeout (which means rrr_conf = 3)
8588 		 * we don't want to check the timer. It may
8589 		 * be going off for a pace and thats ok we
8590 		 * want to send the retransmit (if its ready).
8591 		 *
8592 		 * If its on a normal rack timer (non-min) then
8593 		 * we will check if its expired.
8594 		 */
8595 		goto skip_time_check;
8596 	}
8597 	if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
8598 		uint32_t left;
8599 
8600 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
8601 			ret = -1;
8602 			rack_log_to_processing(rack, cts, ret, 0);
8603 			return (0);
8604 		}
8605 		if (hpts_calling == 0) {
8606 			/*
8607 			 * A user send or queued mbuf (sack) has called us? We
8608 			 * return 0 and let the pacing guards
8609 			 * deal with it if they should or
8610 			 * should not cause a send.
8611 			 */
8612 			ret = -2;
8613 			rack_log_to_processing(rack, cts, ret, 0);
8614 			return (0);
8615 		}
8616 		/*
8617 		 * Ok our timer went off early and we are not paced false
8618 		 * alarm, go back to sleep. We make sure we don't have
8619 		 * no-sack wakeup on since we no longer have a PKT_OUTPUT
8620 		 * flag in place.
8621 		 */
8622 		rack->rc_tp->t_flags2 &= ~TF2_DONT_SACK_QUEUE;
8623 		ret = -3;
8624 		left = rack->r_ctl.rc_timer_exp - cts;
8625 		tcp_hpts_insert(tp, HPTS_MS_TO_SLOTS(left));
8626 		rack_log_to_processing(rack, cts, ret, left);
8627 		return (1);
8628 	}
8629 skip_time_check:
8630 	rack->rc_tmr_stopped = 0;
8631 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_MASK;
8632 	if (timers & PACE_TMR_DELACK) {
8633 		ret = rack_timeout_delack(tp, rack, cts);
8634 	} else if (timers & PACE_TMR_RACK) {
8635 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
8636 		rack->r_fast_output = 0;
8637 		ret = rack_timeout_rack(tp, rack, cts);
8638 	} else if (timers & PACE_TMR_TLP) {
8639 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
8640 		ret = rack_timeout_tlp(tp, rack, cts, doing_tlp);
8641 	} else if (timers & PACE_TMR_RXT) {
8642 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
8643 		rack->r_fast_output = 0;
8644 		ret = rack_timeout_rxt(tp, rack, cts);
8645 	} else if (timers & PACE_TMR_PERSIT) {
8646 		ret = rack_timeout_persist(tp, rack, cts);
8647 	} else if (timers & PACE_TMR_KEEP) {
8648 		ret = rack_timeout_keepalive(tp, rack, cts);
8649 	}
8650 	rack_log_to_processing(rack, cts, ret, timers);
8651 	return (ret);
8652 }
8653 
8654 static void
rack_timer_cancel(struct tcpcb * tp,struct tcp_rack * rack,uint32_t cts,int line)8655 rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line)
8656 {
8657 	struct timeval tv;
8658 	uint32_t us_cts, flags_on_entry;
8659 	uint8_t hpts_removed = 0;
8660 
8661 	flags_on_entry = rack->r_ctl.rc_hpts_flags;
8662 	us_cts = tcp_get_usecs(&tv);
8663 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
8664 	    ((TSTMP_GEQ(us_cts, rack->r_ctl.rc_last_output_to)) ||
8665 	     ((tp->snd_max - tp->snd_una) == 0))) {
8666 		tcp_hpts_remove(rack->rc_tp);
8667 		hpts_removed = 1;
8668 		/* If we were not delayed cancel out the flag. */
8669 		if ((tp->snd_max - tp->snd_una) == 0)
8670 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
8671 		rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
8672 	}
8673 	if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
8674 		rack->rc_tmr_stopped = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
8675 		if (tcp_in_hpts(rack->rc_tp) &&
8676 		    ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)) {
8677 			/*
8678 			 * Canceling timer's when we have no output being
8679 			 * paced. We also must remove ourselves from the
8680 			 * hpts.
8681 			 */
8682 			tcp_hpts_remove(rack->rc_tp);
8683 			hpts_removed = 1;
8684 		}
8685 		rack->r_ctl.rc_hpts_flags &= ~(PACE_TMR_MASK);
8686 	}
8687 	if (hpts_removed == 0)
8688 		rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
8689 }
8690 
8691 static int
rack_stopall(struct tcpcb * tp)8692 rack_stopall(struct tcpcb *tp)
8693 {
8694 	struct tcp_rack *rack;
8695 
8696 	rack = (struct tcp_rack *)tp->t_fb_ptr;
8697 	rack->t_timers_stopped = 1;
8698 
8699 	tcp_hpts_remove(tp);
8700 
8701 	return (0);
8702 }
8703 
8704 static void
rack_stop_all_timers(struct tcpcb * tp,struct tcp_rack * rack)8705 rack_stop_all_timers(struct tcpcb *tp, struct tcp_rack *rack)
8706 {
8707 	/*
8708 	 * Assure no timers are running.
8709 	 */
8710 	if (tcp_timer_active(tp, TT_PERSIST)) {
8711 		/* We enter in persists, set the flag appropriately */
8712 		rack->rc_in_persist = 1;
8713 	}
8714 	if (tcp_in_hpts(rack->rc_tp)) {
8715 		tcp_hpts_remove(rack->rc_tp);
8716 	}
8717 }
8718 
8719 /*
8720  * We maintain an array fo 16 (RETRAN_CNT_SIZE) entries. This
8721  * array is zeroed at the start of recovery. Each time a segment
8722  * is retransmitted, we translate that into a number of packets
8723  * (based on segsiz) and based on how many times its been retransmitted
8724  * increment by the number of packets the counter that represents
8725  * retansmitted N times. Index 0 is retransmitted 1 time, index 1
8726  * is retransmitted 2 times etc.
8727  *
8728  * So for example when we send a 4344 byte transmission with a 1448
8729  * byte segsize, and its the third time we have retransmitted this
8730  * segment, we would add to the rc_cnt_of_retran[2] the value of
8731  * 3. That represents 3 MSS were retransmitted 3 times (index is
8732  * the number of times retranmitted minus 1).
8733  */
8734 static void
rack_peg_rxt(struct tcp_rack * rack,struct rack_sendmap * rsm,uint32_t segsiz)8735 rack_peg_rxt(struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t segsiz)
8736 {
8737 	int idx;
8738 	uint32_t peg;
8739 
8740 	peg = ((rsm->r_end - rsm->r_start) + segsiz) - 1;
8741 	peg /= segsiz;
8742 	idx = rsm->r_act_rxt_cnt - 1;
8743 	if (idx >= RETRAN_CNT_SIZE)
8744 		idx = RETRAN_CNT_SIZE - 1;
8745 	/* Max of a uint16_t retransmits in a bucket */
8746 	if ((rack->r_ctl.rc_cnt_of_retran[idx] + peg) < 0xffff)
8747 		rack->r_ctl.rc_cnt_of_retran[idx] += peg;
8748 	else
8749 		rack->r_ctl.rc_cnt_of_retran[idx] = 0xffff;
8750 }
8751 
8752 /*
8753  * We maintain an array fo 16 (RETRAN_CNT_SIZE) entries. This
8754  * array is zeroed at the start of recovery. Each time a segment
8755  * is retransmitted, we translate that into a number of packets
8756  * (based on segsiz) and based on how many times its been retransmitted
8757  * increment by the number of packets the counter that represents
8758  * retansmitted N times. Index 0 is retransmitted 1 time, index 1
8759  * is retransmitted 2 times etc.
8760  *
8761  * The rack_unpeg_rxt is used when we go to retransmit a segment
8762  * again. Basically if the segment had previously been retransmitted
8763  * say 3 times (as our previous example illustrated in the comment
8764  * above rack_peg_rxt() prior to calling that and incrementing
8765  * r_ack_rxt_cnt we would have called rack_unpeg_rxt() that would
8766  * subtract back the previous add from its last rxt (in this
8767  * example r_act_cnt would have been 2 for 2 retransmissions. So
8768  * we would have subtracted 3 from rc_cnt_of_reetran[1] to remove
8769  * those 3 segments. You will see this in the rack_update_rsm()
8770  * below where we do:
8771  *	if (rsm->r_act_rxt_cnt > 0) {
8772  *		rack_unpeg_rxt(rack, rsm, segsiz);
8773  *	}
8774  *	rsm->r_act_rxt_cnt++;
8775  *	rack_peg_rxt(rack, rsm, segsiz);
8776  *
8777  * This effectively moves the count from rc_cnt_of_retran[1] to
8778  * rc_cnt_of_retran[2].
8779  */
8780 static void
rack_unpeg_rxt(struct tcp_rack * rack,struct rack_sendmap * rsm,uint32_t segsiz)8781 rack_unpeg_rxt(struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t segsiz)
8782 {
8783 	int idx;
8784 	uint32_t peg;
8785 
8786 	idx = rsm->r_act_rxt_cnt - 1;
8787 	if (idx >= RETRAN_CNT_SIZE)
8788 		idx = RETRAN_CNT_SIZE - 1;
8789 	peg = ((rsm->r_end - rsm->r_start) + segsiz) - 1;
8790 	peg /= segsiz;
8791 	if (peg < rack->r_ctl.rc_cnt_of_retran[idx])
8792 		rack->r_ctl.rc_cnt_of_retran[idx] -= peg;
8793 	else {
8794 		/* TSNH */
8795 		rack->r_ctl.rc_cnt_of_retran[idx] = 0;
8796 	}
8797 }
8798 
8799 static void
rack_update_rsm(struct tcpcb * tp,struct tcp_rack * rack,struct rack_sendmap * rsm,uint64_t ts,uint32_t add_flag,int segsiz)8800 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
8801     struct rack_sendmap *rsm, uint64_t ts, uint32_t add_flag, int segsiz)
8802 {
8803 	int32_t idx;
8804 
8805 	rsm->r_rtr_cnt++;
8806 	if (rsm->r_rtr_cnt > RACK_NUM_OF_RETRANS) {
8807 		rsm->r_rtr_cnt = RACK_NUM_OF_RETRANS;
8808 		rsm->r_flags |= RACK_OVERMAX;
8809 	}
8810 	if (rsm->r_act_rxt_cnt > 0) {
8811 		/* Drop the count back for this, its retransmitting again */
8812 		rack_unpeg_rxt(rack, rsm, segsiz);
8813 	}
8814 	rsm->r_act_rxt_cnt++;
8815 	/* Peg the count/index */
8816 	rack_peg_rxt(rack, rsm, segsiz);
8817 	rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
8818 	rsm->r_dupack = 0;
8819 	if ((rsm->r_rtr_cnt > 1) && ((rsm->r_flags & RACK_TLP) == 0)) {
8820 		rack->r_ctl.rc_holes_rxt += (rsm->r_end - rsm->r_start);
8821 		rsm->r_rtr_bytes += (rsm->r_end - rsm->r_start);
8822 	}
8823 	if (rsm->r_flags & RACK_WAS_LOST) {
8824 		/*
8825 		 * We retransmitted it putting it back in flight
8826 		 * remove the lost desgination and reduce the
8827 		 * bytes considered lost.
8828 		 */
8829 		rsm->r_flags  &= ~RACK_WAS_LOST;
8830 		KASSERT((rack->r_ctl.rc_considered_lost >= (rsm->r_end - rsm->r_start)),
8831 			("rsm:%p rack:%p rc_considered_lost goes negative", rsm,  rack));
8832 		if (rack->r_ctl.rc_considered_lost >= (rsm->r_end - rsm->r_start))
8833 			rack->r_ctl.rc_considered_lost -= rsm->r_end - rsm->r_start;
8834 		else
8835 			rack->r_ctl.rc_considered_lost = 0;
8836 	}
8837 	idx = rsm->r_rtr_cnt - 1;
8838 	rsm->r_tim_lastsent[idx] = ts;
8839 	/*
8840 	 * Here we don't add in the len of send, since its already
8841 	 * in snduna <->snd_max.
8842 	 */
8843 	rsm->r_fas = ctf_flight_size(rack->rc_tp,
8844 				     rack->r_ctl.rc_sacked);
8845 	if (rsm->r_flags & RACK_ACKED) {
8846 		/* Problably MTU discovery messing with us */
8847 		rsm->r_flags &= ~RACK_ACKED;
8848 		rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
8849 	}
8850 	if (rsm->r_in_tmap) {
8851 		TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8852 		rsm->r_in_tmap = 0;
8853 	}
8854 	/* Lets make sure it really is in or not the GP window */
8855 	rack_mark_in_gp_win(tp, rsm);
8856 	TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8857 	rsm->r_in_tmap = 1;
8858 	rsm->r_bas = (uint8_t)(((rsm->r_end - rsm->r_start) + segsiz - 1) / segsiz);
8859 	/* Take off the must retransmit flag, if its on */
8860 	if (rsm->r_flags & RACK_MUST_RXT) {
8861 		if (rack->r_must_retran)
8862 			rack->r_ctl.rc_out_at_rto -= (rsm->r_end - rsm->r_start);
8863 		if (SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) {
8864 			/*
8865 			 * We have retransmitted all we need. Clear
8866 			 * any must retransmit flags.
8867 			 */
8868 			rack->r_must_retran = 0;
8869 			rack->r_ctl.rc_out_at_rto = 0;
8870 		}
8871 		rsm->r_flags &= ~RACK_MUST_RXT;
8872 	}
8873 	/* Remove any collapsed flag */
8874 	rsm->r_flags &= ~RACK_RWND_COLLAPSED;
8875 	if (rsm->r_flags & RACK_SACK_PASSED) {
8876 		/* We have retransmitted due to the SACK pass */
8877 		rsm->r_flags &= ~RACK_SACK_PASSED;
8878 		rsm->r_flags |= RACK_WAS_SACKPASS;
8879 	}
8880 }
8881 
8882 static uint32_t
rack_update_entry(struct tcpcb * tp,struct tcp_rack * rack,struct rack_sendmap * rsm,uint64_t ts,int32_t * lenp,uint32_t add_flag,int segsiz)8883 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
8884     struct rack_sendmap *rsm, uint64_t ts, int32_t *lenp, uint32_t add_flag, int segsiz)
8885 {
8886 	/*
8887 	 * We (re-)transmitted starting at rsm->r_start for some length
8888 	 * (possibly less than r_end.
8889 	 */
8890 	struct rack_sendmap *nrsm;
8891 	int insret __diagused;
8892 	uint32_t c_end;
8893 	int32_t len;
8894 
8895 	len = *lenp;
8896 	c_end = rsm->r_start + len;
8897 	if (SEQ_GEQ(c_end, rsm->r_end)) {
8898 		/*
8899 		 * We retransmitted the whole piece or more than the whole
8900 		 * slopping into the next rsm.
8901 		 */
8902 		rack_update_rsm(tp, rack, rsm, ts, add_flag, segsiz);
8903 		if (c_end == rsm->r_end) {
8904 			*lenp = 0;
8905 			return (0);
8906 		} else {
8907 			int32_t act_len;
8908 
8909 			/* Hangs over the end return whats left */
8910 			act_len = rsm->r_end - rsm->r_start;
8911 			*lenp = (len - act_len);
8912 			return (rsm->r_end);
8913 		}
8914 		/* We don't get out of this block. */
8915 	}
8916 	/*
8917 	 * Here we retransmitted less than the whole thing which means we
8918 	 * have to split this into what was transmitted and what was not.
8919 	 */
8920 	nrsm = rack_alloc_full_limit(rack);
8921 	if (nrsm == NULL) {
8922 		/*
8923 		 * We can't get memory, so lets not proceed.
8924 		 */
8925 		*lenp = 0;
8926 		return (0);
8927 	}
8928 	/*
8929 	 * So here we are going to take the original rsm and make it what we
8930 	 * retransmitted. nrsm will be the tail portion we did not
8931 	 * retransmit. For example say the chunk was 1, 11 (10 bytes). And
8932 	 * we retransmitted 5 bytes i.e. 1, 5. The original piece shrinks to
8933 	 * 1, 6 and the new piece will be 6, 11.
8934 	 */
8935 	rack_clone_rsm(rack, nrsm, rsm, c_end);
8936 	nrsm->r_dupack = 0;
8937 	rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
8938 #ifndef INVARIANTS
8939 	(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
8940 #else
8941 	if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
8942 		panic("Insert in tailq_hash of %p fails ret:%d rack:%p rsm:%p",
8943 		      nrsm, insret, rack, rsm);
8944 	}
8945 #endif
8946 	if (rsm->r_in_tmap) {
8947 		TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8948 		nrsm->r_in_tmap = 1;
8949 	}
8950 	rsm->r_flags &= (~RACK_HAS_FIN);
8951 	rack_update_rsm(tp, rack, rsm, ts, add_flag, segsiz);
8952 	/* Log a split of rsm into rsm and nrsm */
8953 	rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
8954 	*lenp = 0;
8955 	return (0);
8956 }
8957 
8958 static void
rack_log_output(struct tcpcb * tp,struct tcpopt * to,int32_t len,uint32_t seq_out,uint16_t th_flags,int32_t err,uint64_t cts,struct rack_sendmap * hintrsm,uint32_t add_flag,struct mbuf * s_mb,uint32_t s_moff,int hw_tls,int segsiz)8959 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
8960 		uint32_t seq_out, uint16_t th_flags, int32_t err, uint64_t cts,
8961 		struct rack_sendmap *hintrsm, uint32_t add_flag, struct mbuf *s_mb,
8962 		uint32_t s_moff, int hw_tls, int segsiz)
8963 {
8964 	struct tcp_rack *rack;
8965 	struct rack_sendmap *rsm, *nrsm;
8966 	int insret __diagused;
8967 
8968 	register uint32_t snd_max, snd_una;
8969 
8970 	/*
8971 	 * Add to the RACK log of packets in flight or retransmitted. If
8972 	 * there is a TS option we will use the TS echoed, if not we will
8973 	 * grab a TS.
8974 	 *
8975 	 * Retransmissions will increment the count and move the ts to its
8976 	 * proper place. Note that if options do not include TS's then we
8977 	 * won't be able to effectively use the ACK for an RTT on a retran.
8978 	 *
8979 	 * Notes about r_start and r_end. Lets consider a send starting at
8980 	 * sequence 1 for 10 bytes. In such an example the r_start would be
8981 	 * 1 (starting sequence) but the r_end would be r_start+len i.e. 11.
8982 	 * This means that r_end is actually the first sequence for the next
8983 	 * slot (11).
8984 	 *
8985 	 */
8986 	/*
8987 	 * If err is set what do we do XXXrrs? should we not add the thing?
8988 	 * -- i.e. return if err != 0 or should we pretend we sent it? --
8989 	 * i.e. proceed with add ** do this for now.
8990 	 */
8991 	INP_WLOCK_ASSERT(tptoinpcb(tp));
8992 	if (err)
8993 		/*
8994 		 * We don't log errors -- we could but snd_max does not
8995 		 * advance in this case either.
8996 		 */
8997 		return;
8998 
8999 	if (th_flags & TH_RST) {
9000 		/*
9001 		 * We don't log resets and we return immediately from
9002 		 * sending
9003 		 */
9004 		return;
9005 	}
9006 	rack = (struct tcp_rack *)tp->t_fb_ptr;
9007 	snd_una = tp->snd_una;
9008 	snd_max = tp->snd_max;
9009 	if (th_flags & (TH_SYN | TH_FIN)) {
9010 		/*
9011 		 * The call to rack_log_output is made before bumping
9012 		 * snd_max. This means we can record one extra byte on a SYN
9013 		 * or FIN if seq_out is adding more on and a FIN is present
9014 		 * (and we are not resending).
9015 		 */
9016 		if ((th_flags & TH_SYN) && (seq_out == tp->iss))
9017 			len++;
9018 		if (th_flags & TH_FIN)
9019 			len++;
9020 	}
9021 	if (SEQ_LEQ((seq_out + len), snd_una)) {
9022 		/* Are sending an old segment to induce an ack (keep-alive)? */
9023 		return;
9024 	}
9025 	if (SEQ_LT(seq_out, snd_una)) {
9026 		/* huh? should we panic? */
9027 		uint32_t end;
9028 
9029 		end = seq_out + len;
9030 		seq_out = snd_una;
9031 		if (SEQ_GEQ(end, seq_out))
9032 			len = end - seq_out;
9033 		else
9034 			len = 0;
9035 	}
9036 	if (len == 0) {
9037 		/* We don't log zero window probes */
9038 		return;
9039 	}
9040 	if (IN_FASTRECOVERY(tp->t_flags)) {
9041 		rack->r_ctl.rc_prr_out += len;
9042 	}
9043 	/* First question is it a retransmission or new? */
9044 	if (seq_out == snd_max) {
9045 		/* Its new */
9046 		rack_chk_req_and_hybrid_on_out(rack, seq_out, len, cts);
9047 again:
9048 		rsm = rack_alloc(rack);
9049 		if (rsm == NULL) {
9050 			/*
9051 			 * Hmm out of memory and the tcb got destroyed while
9052 			 * we tried to wait.
9053 			 */
9054 			return;
9055 		}
9056 		if (th_flags & TH_FIN) {
9057 			rsm->r_flags = RACK_HAS_FIN|add_flag;
9058 		} else {
9059 			rsm->r_flags = add_flag;
9060 		}
9061 		if (hw_tls)
9062 			rsm->r_hw_tls = 1;
9063 		rsm->r_tim_lastsent[0] = cts;
9064 		rsm->r_rtr_cnt = 1;
9065  		rsm->r_act_rxt_cnt = 0;
9066 		rsm->r_rtr_bytes = 0;
9067 		if (th_flags & TH_SYN) {
9068 			/* The data space is one beyond snd_una */
9069 			rsm->r_flags |= RACK_HAS_SYN;
9070 		}
9071 		rsm->r_start = seq_out;
9072 		rsm->r_end = rsm->r_start + len;
9073 		rack_mark_in_gp_win(tp, rsm);
9074 		rsm->r_dupack = 0;
9075 		/*
9076 		 * save off the mbuf location that
9077 		 * sndmbuf_noadv returned (which is
9078 		 * where we started copying from)..
9079 		 */
9080 		rsm->m = s_mb;
9081 		rsm->soff = s_moff;
9082 		/*
9083 		 * Here we do add in the len of send, since its not yet
9084 		 * reflected in in snduna <->snd_max
9085 		 */
9086 		rsm->r_fas = (ctf_flight_size(rack->rc_tp,
9087 					      rack->r_ctl.rc_sacked) +
9088 			      (rsm->r_end - rsm->r_start));
9089 		if ((rack->rc_initial_ss_comp == 0) &&
9090 		    (rack->r_ctl.ss_hi_fs < rsm->r_fas)) {
9091 			   rack->r_ctl.ss_hi_fs = rsm->r_fas;
9092 		}
9093 		/* rsm->m will be NULL if RACK_HAS_SYN or RACK_HAS_FIN is set */
9094 		if (rsm->m) {
9095 			if (rsm->m->m_len <= rsm->soff) {
9096 				/*
9097 				 * XXXrrs Question, will this happen?
9098 				 *
9099 				 * If sbsndptr is set at the correct place
9100 				 * then s_moff should always be somewhere
9101 				 * within rsm->m. But if the sbsndptr was
9102 				 * off then that won't be true. If it occurs
9103 				 * we need to walkout to the correct location.
9104 				 */
9105 				struct mbuf *lm;
9106 
9107 				lm = rsm->m;
9108 				while (lm->m_len <= rsm->soff) {
9109 					rsm->soff -= lm->m_len;
9110 					lm = lm->m_next;
9111 					KASSERT(lm != NULL, ("%s rack:%p lm goes null orig_off:%u origmb:%p rsm->soff:%u",
9112 							     __func__, rack, s_moff, s_mb, rsm->soff));
9113 				}
9114 				rsm->m = lm;
9115 			}
9116 			rsm->orig_m_len = rsm->m->m_len;
9117 			rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
9118 		} else {
9119 			rsm->orig_m_len = 0;
9120 			rsm->orig_t_space = 0;
9121 		}
9122 		rsm->r_bas = (uint8_t)((len + segsiz - 1) / segsiz);
9123 		rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
9124 		/* Log a new rsm */
9125 		rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_NEW, 0, __LINE__);
9126 #ifndef INVARIANTS
9127 		(void)tqhash_insert(rack->r_ctl.tqh, rsm);
9128 #else
9129 		if ((insret = tqhash_insert(rack->r_ctl.tqh, rsm)) != 0) {
9130 			panic("Insert in tailq_hash of %p fails ret:%d rack:%p rsm:%p",
9131 			      nrsm, insret, rack, rsm);
9132 		}
9133 #endif
9134 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
9135 		rsm->r_in_tmap = 1;
9136 		if (rsm->r_flags & RACK_IS_PCM) {
9137 			rack->r_ctl.pcm_i.send_time = cts;
9138 			rack->r_ctl.pcm_i.eseq = rsm->r_end;
9139 			/* First time through we set the start too */
9140 			if (rack->pcm_in_progress == 0)
9141 				rack->r_ctl.pcm_i.sseq = rsm->r_start;
9142 		}
9143 		/*
9144 		 * Special case detection, is there just a single
9145 		 * packet outstanding when we are not in recovery?
9146 		 *
9147 		 * If this is true mark it so.
9148 		 */
9149 		if ((IN_FASTRECOVERY(tp->t_flags) == 0) &&
9150 		    (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) == ctf_fixed_maxseg(tp))) {
9151 			struct rack_sendmap *prsm;
9152 
9153 			prsm = tqhash_prev(rack->r_ctl.tqh, rsm);
9154 			if (prsm)
9155 				prsm->r_one_out_nr = 1;
9156 		}
9157 		return;
9158 	}
9159 	/*
9160 	 * If we reach here its a retransmission and we need to find it.
9161 	 */
9162 more:
9163 	if (hintrsm && (hintrsm->r_start == seq_out)) {
9164 		rsm = hintrsm;
9165 		hintrsm = NULL;
9166 	} else {
9167 		/* No hints sorry */
9168 		rsm = NULL;
9169 	}
9170 	if ((rsm) && (rsm->r_start == seq_out)) {
9171 		seq_out = rack_update_entry(tp, rack, rsm, cts, &len, add_flag, segsiz);
9172 		if (len == 0) {
9173 			return;
9174 		} else {
9175 			goto more;
9176 		}
9177 	}
9178 	/* Ok it was not the last pointer go through it the hard way. */
9179 refind:
9180 	rsm = tqhash_find(rack->r_ctl.tqh, seq_out);
9181 	if (rsm) {
9182 		if (rsm->r_start == seq_out) {
9183 			seq_out = rack_update_entry(tp, rack, rsm, cts, &len, add_flag, segsiz);
9184 			if (len == 0) {
9185 				return;
9186 			} else {
9187 				goto refind;
9188 			}
9189 		}
9190 		if (SEQ_GEQ(seq_out, rsm->r_start) && SEQ_LT(seq_out, rsm->r_end)) {
9191 			/* Transmitted within this piece */
9192 			/*
9193 			 * Ok we must split off the front and then let the
9194 			 * update do the rest
9195 			 */
9196 			nrsm = rack_alloc_full_limit(rack);
9197 			if (nrsm == NULL) {
9198 				rack_update_rsm(tp, rack, rsm, cts, add_flag, segsiz);
9199 				return;
9200 			}
9201 			/*
9202 			 * copy rsm to nrsm and then trim the front of rsm
9203 			 * to not include this part.
9204 			 */
9205 			rack_clone_rsm(rack, nrsm, rsm, seq_out);
9206 			rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
9207 #ifndef INVARIANTS
9208 			(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
9209 #else
9210 			if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
9211 				panic("Insert in tailq_hash of %p fails ret:%d rack:%p rsm:%p",
9212 				      nrsm, insret, rack, rsm);
9213 			}
9214 #endif
9215 			if (rsm->r_in_tmap) {
9216 				TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
9217 				nrsm->r_in_tmap = 1;
9218 			}
9219 			rsm->r_flags &= (~RACK_HAS_FIN);
9220 			seq_out = rack_update_entry(tp, rack, nrsm, cts, &len, add_flag, segsiz);
9221 			if (len == 0) {
9222 				return;
9223 			} else if (len > 0)
9224 				goto refind;
9225 		}
9226 	}
9227 	/*
9228 	 * Hmm not found in map did they retransmit both old and on into the
9229 	 * new?
9230 	 */
9231 	if (seq_out == tp->snd_max) {
9232 		goto again;
9233 	} else if (SEQ_LT(seq_out, tp->snd_max)) {
9234 #ifdef INVARIANTS
9235 		printf("seq_out:%u len:%d snd_una:%u snd_max:%u -- but rsm not found?\n",
9236 		       seq_out, len, tp->snd_una, tp->snd_max);
9237 		printf("Starting Dump of all rack entries\n");
9238 		TQHASH_FOREACH(rsm, rack->r_ctl.tqh)  {
9239 			printf("rsm:%p start:%u end:%u\n",
9240 			       rsm, rsm->r_start, rsm->r_end);
9241 		}
9242 		printf("Dump complete\n");
9243 		panic("seq_out not found rack:%p tp:%p",
9244 		      rack, tp);
9245 #endif
9246 	} else {
9247 #ifdef INVARIANTS
9248 		/*
9249 		 * Hmm beyond sndmax? (only if we are using the new rtt-pack
9250 		 * flag)
9251 		 */
9252 		panic("seq_out:%u(%d) is beyond snd_max:%u tp:%p",
9253 		      seq_out, len, tp->snd_max, tp);
9254 #endif
9255 	}
9256 }
9257 
9258 /*
9259  * Record one of the RTT updates from an ack into
9260  * our sample structure.
9261  */
9262 
9263 static void
tcp_rack_xmit_timer(struct tcp_rack * rack,int32_t rtt,uint32_t len,uint32_t us_rtt,int confidence,struct rack_sendmap * rsm,uint16_t rtrcnt)9264 tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt, uint32_t len, uint32_t us_rtt,
9265 		    int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt)
9266 {
9267 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
9268 	    (rack->r_ctl.rack_rs.rs_rtt_lowest > rtt)) {
9269 		rack->r_ctl.rack_rs.rs_rtt_lowest = rtt;
9270 	}
9271 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
9272 	    (rack->r_ctl.rack_rs.rs_rtt_highest < rtt)) {
9273 		rack->r_ctl.rack_rs.rs_rtt_highest = rtt;
9274 	}
9275 	if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
9276 	    if (us_rtt < rack->r_ctl.rc_gp_lowrtt)
9277 		rack->r_ctl.rc_gp_lowrtt = us_rtt;
9278 	    if (rack->rc_tp->snd_wnd > rack->r_ctl.rc_gp_high_rwnd)
9279 		    rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
9280 	}
9281 	if ((confidence == 1) &&
9282 	    ((rsm == NULL) ||
9283 	     (rsm->r_just_ret) ||
9284 	     (rsm->r_one_out_nr &&
9285 	      len < (ctf_fixed_maxseg(rack->rc_tp) * 2)))) {
9286 		/*
9287 		 * If the rsm had a just return
9288 		 * hit it then we can't trust the
9289 		 * rtt measurement for buffer deterimination
9290 		 * Note that a confidence of 2, indicates
9291 		 * SACK'd which overrides the r_just_ret or
9292 		 * the r_one_out_nr. If it was a CUM-ACK and
9293 		 * we had only two outstanding, but get an
9294 		 * ack for only 1. Then that also lowers our
9295 		 * confidence.
9296 		 */
9297 		confidence = 0;
9298 	}
9299 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
9300 	    (rack->r_ctl.rack_rs.rs_us_rtt > us_rtt)) {
9301 		if (rack->r_ctl.rack_rs.confidence == 0) {
9302 			/*
9303 			 * We take anything with no current confidence
9304 			 * saved.
9305 			 */
9306 			rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
9307 			rack->r_ctl.rack_rs.confidence = confidence;
9308 			rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
9309 		} else if (confidence != 0) {
9310 			/*
9311 			 * Once we have a confident number,
9312 			 * we can update it with a smaller
9313 			 * value since this confident number
9314 			 * may include the DSACK time until
9315 			 * the next segment (the second one) arrived.
9316 			 */
9317 			rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
9318 			rack->r_ctl.rack_rs.confidence = confidence;
9319 			rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
9320 		}
9321 	}
9322 	rack_log_rtt_upd(rack->rc_tp, rack, us_rtt, len, rsm, confidence);
9323 	rack->r_ctl.rack_rs.rs_flags = RACK_RTT_VALID;
9324 	rack->r_ctl.rack_rs.rs_rtt_tot += rtt;
9325 	rack->r_ctl.rack_rs.rs_rtt_cnt++;
9326 }
9327 
9328 /*
9329  * Collect new round-trip time estimate
9330  * and update averages and current timeout.
9331  */
9332 static void
tcp_rack_xmit_timer_commit(struct tcp_rack * rack,struct tcpcb * tp)9333 tcp_rack_xmit_timer_commit(struct tcp_rack *rack, struct tcpcb *tp)
9334 {
9335 	int32_t delta;
9336 	int32_t rtt;
9337 
9338 	if (rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY)
9339 		/* No valid sample */
9340 		return;
9341 	if (rack->r_ctl.rc_rate_sample_method == USE_RTT_LOW) {
9342 		/* We are to use the lowest RTT seen in a single ack */
9343 		rtt = rack->r_ctl.rack_rs.rs_rtt_lowest;
9344 	} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_HIGH) {
9345 		/* We are to use the highest RTT seen in a single ack */
9346 		rtt = rack->r_ctl.rack_rs.rs_rtt_highest;
9347 	} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_AVG) {
9348 		/* We are to use the average RTT seen in a single ack */
9349 		rtt = (int32_t)(rack->r_ctl.rack_rs.rs_rtt_tot /
9350 				(uint64_t)rack->r_ctl.rack_rs.rs_rtt_cnt);
9351 	} else {
9352 #ifdef INVARIANTS
9353 		panic("Unknown rtt variant %d", rack->r_ctl.rc_rate_sample_method);
9354 #endif
9355 		return;
9356 	}
9357 	if (rtt == 0)
9358 		rtt = 1;
9359 	if (rack->rc_gp_rtt_set == 0) {
9360 		/*
9361 		 * With no RTT we have to accept
9362 		 * even one we are not confident of.
9363 		 */
9364 		rack->r_ctl.rc_gp_srtt = rack->r_ctl.rack_rs.rs_us_rtt;
9365 		rack->rc_gp_rtt_set = 1;
9366 	} else if (rack->r_ctl.rack_rs.confidence) {
9367 		/* update the running gp srtt */
9368 		rack->r_ctl.rc_gp_srtt -= (rack->r_ctl.rc_gp_srtt/8);
9369 		rack->r_ctl.rc_gp_srtt += rack->r_ctl.rack_rs.rs_us_rtt / 8;
9370 	}
9371 	if (rack->r_ctl.rack_rs.confidence) {
9372 		/*
9373 		 * record the low and high for highly buffered path computation,
9374 		 * we only do this if we are confident (not a retransmission).
9375 		 */
9376 		if (rack->r_ctl.rc_highest_us_rtt < rack->r_ctl.rack_rs.rs_us_rtt) {
9377 			rack->r_ctl.rc_highest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
9378 		}
9379 		if (rack->rc_highly_buffered == 0) {
9380 			/*
9381 			 * Currently once we declare a path has
9382 			 * highly buffered there is no going
9383 			 * back, which may be a problem...
9384 			 */
9385 			if ((rack->r_ctl.rc_highest_us_rtt / rack->r_ctl.rc_lowest_us_rtt) > rack_hbp_thresh) {
9386 				rack_log_rtt_shrinks(rack, rack->r_ctl.rack_rs.rs_us_rtt,
9387 						     rack->r_ctl.rc_highest_us_rtt,
9388 						     rack->r_ctl.rc_lowest_us_rtt,
9389 						     RACK_RTTS_SEEHBP);
9390 				rack->rc_highly_buffered = 1;
9391 			}
9392 		}
9393 	}
9394 	if ((rack->r_ctl.rack_rs.confidence) ||
9395 	    (rack->r_ctl.rack_rs.rs_us_rtrcnt == 1)) {
9396 		/*
9397 		 * If we are highly confident of it <or> it was
9398 		 * never retransmitted we accept it as the last us_rtt.
9399 		 */
9400 		rack->r_ctl.rc_last_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
9401 		/* The lowest rtt can be set if its was not retransmited */
9402 		if (rack->r_ctl.rc_lowest_us_rtt > rack->r_ctl.rack_rs.rs_us_rtt) {
9403 			rack->r_ctl.rc_lowest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
9404 			if (rack->r_ctl.rc_lowest_us_rtt == 0)
9405 				rack->r_ctl.rc_lowest_us_rtt = 1;
9406 		}
9407 	}
9408 	rack = (struct tcp_rack *)tp->t_fb_ptr;
9409 	if (tp->t_srtt != 0) {
9410 		/*
9411 		 * We keep a simple srtt in microseconds, like our rtt
9412 		 * measurement. We don't need to do any tricks with shifting
9413 		 * etc. Instead we just add in 1/8th of the new measurement
9414 		 * and subtract out 1/8 of the old srtt. We do the same with
9415 		 * the variance after finding the absolute value of the
9416 		 * difference between this sample and the current srtt.
9417 		 */
9418 		delta = tp->t_srtt - rtt;
9419 		/* Take off 1/8th of the current sRTT */
9420 		tp->t_srtt -= (tp->t_srtt >> 3);
9421 		/* Add in 1/8th of the new RTT just measured */
9422 		tp->t_srtt += (rtt >> 3);
9423 		if (tp->t_srtt <= 0)
9424 			tp->t_srtt = 1;
9425 		/* Now lets make the absolute value of the variance */
9426 		if (delta < 0)
9427 			delta = -delta;
9428 		/* Subtract out 1/8th */
9429 		tp->t_rttvar -= (tp->t_rttvar >> 3);
9430 		/* Add in 1/8th of the new variance we just saw */
9431 		tp->t_rttvar += (delta >> 3);
9432 		if (tp->t_rttvar <= 0)
9433 			tp->t_rttvar = 1;
9434 	} else {
9435 		/*
9436 		 * No rtt measurement yet - use the unsmoothed rtt. Set the
9437 		 * variance to half the rtt (so our first retransmit happens
9438 		 * at 3*rtt).
9439 		 */
9440 		tp->t_srtt = rtt;
9441 		tp->t_rttvar = rtt >> 1;
9442 	}
9443 	rack->rc_srtt_measure_made = 1;
9444 	KMOD_TCPSTAT_INC(tcps_rttupdated);
9445 	if (tp->t_rttupdated < UCHAR_MAX)
9446 		tp->t_rttupdated++;
9447 #ifdef STATS
9448 	if (rack_stats_gets_ms_rtt == 0) {
9449 		/* Send in the microsecond rtt used for rxt timeout purposes */
9450 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rtt));
9451 	} else if (rack_stats_gets_ms_rtt == 1) {
9452 		/* Send in the millisecond rtt used for rxt timeout purposes */
9453 		int32_t ms_rtt;
9454 
9455 		/* Round up */
9456 		ms_rtt = (rtt + HPTS_USEC_IN_MSEC - 1) / HPTS_USEC_IN_MSEC;
9457 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, ms_rtt));
9458 	} else if (rack_stats_gets_ms_rtt == 2) {
9459 		/* Send in the millisecond rtt has close to the path RTT as we can get  */
9460 		int32_t ms_rtt;
9461 
9462 		/* Round up */
9463 		ms_rtt = (rack->r_ctl.rack_rs.rs_us_rtt + HPTS_USEC_IN_MSEC - 1) / HPTS_USEC_IN_MSEC;
9464 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, ms_rtt));
9465 	}  else {
9466 		/* Send in the microsecond rtt has close to the path RTT as we can get  */
9467 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rack->r_ctl.rack_rs.rs_us_rtt));
9468 	}
9469 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_PATHRTT, imax(0, rack->r_ctl.rack_rs.rs_us_rtt));
9470 #endif
9471 	rack->r_ctl.last_rcv_tstmp_for_rtt = tcp_tv_to_mssectick(&rack->r_ctl.act_rcv_time);
9472 	/*
9473 	 * the retransmit should happen at rtt + 4 * rttvar. Because of the
9474 	 * way we do the smoothing, srtt and rttvar will each average +1/2
9475 	 * tick of bias.  When we compute the retransmit timer, we want 1/2
9476 	 * tick of rounding and 1 extra tick because of +-1/2 tick
9477 	 * uncertainty in the firing of the timer.  The bias will give us
9478 	 * exactly the 1.5 tick we need.  But, because the bias is
9479 	 * statistical, we have to test that we don't drop below the minimum
9480 	 * feasible timer (which is 2 ticks).
9481 	 */
9482 	tp->t_rxtshift = 0;
9483 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
9484 		      max(rack_rto_min, rtt + 2), rack_rto_max, rack->r_ctl.timer_slop);
9485 	rack_log_rtt_sample(rack, rtt);
9486 	tp->t_softerror = 0;
9487 }
9488 
9489 
9490 static void
rack_apply_updated_usrtt(struct tcp_rack * rack,uint32_t us_rtt,uint32_t us_cts)9491 rack_apply_updated_usrtt(struct tcp_rack *rack, uint32_t us_rtt, uint32_t us_cts)
9492 {
9493 	/*
9494 	 * Apply to filter the inbound us-rtt at us_cts.
9495 	 */
9496 	uint32_t old_rtt;
9497 
9498 	old_rtt = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
9499 	apply_filter_min_small(&rack->r_ctl.rc_gp_min_rtt,
9500 			       us_rtt, us_cts);
9501 	if (old_rtt > us_rtt) {
9502 		/* We just hit a new lower rtt time */
9503 		rack_log_rtt_shrinks(rack,  us_cts,  old_rtt,
9504 				     __LINE__, RACK_RTTS_NEWRTT);
9505 		/*
9506 		 * Only count it if its lower than what we saw within our
9507 		 * calculated range.
9508 		 */
9509 		if ((old_rtt - us_rtt) > rack_min_rtt_movement) {
9510 			if (rack_probertt_lower_within &&
9511 			    rack->rc_gp_dyn_mul &&
9512 			    (rack->use_fixed_rate == 0) &&
9513 			    (rack->rc_always_pace)) {
9514 				/*
9515 				 * We are seeing a new lower rtt very close
9516 				 * to the time that we would have entered probe-rtt.
9517 				 * This is probably due to the fact that a peer flow
9518 				 * has entered probe-rtt. Lets go in now too.
9519 				 */
9520 				uint32_t val;
9521 
9522 				val = rack_probertt_lower_within * rack_time_between_probertt;
9523 				val /= 100;
9524 				if ((rack->in_probe_rtt == 0)  &&
9525 				    (rack->rc_skip_timely == 0) &&
9526 				    ((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= (rack_time_between_probertt - val)))	{
9527 					rack_enter_probertt(rack, us_cts);
9528 				}
9529 			}
9530 			rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
9531 		}
9532 	}
9533 }
9534 
9535 static int
rack_update_rtt(struct tcpcb * tp,struct tcp_rack * rack,struct rack_sendmap * rsm,struct tcpopt * to,uint32_t cts,int32_t ack_type,tcp_seq th_ack)9536 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
9537     struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack)
9538 {
9539 	uint32_t us_rtt;
9540 	int32_t i, all;
9541 	uint32_t t, len_acked;
9542 
9543 	if ((rsm->r_flags & RACK_ACKED) ||
9544 	    (rsm->r_flags & RACK_WAS_ACKED))
9545 		/* Already done */
9546 		return (0);
9547 	if (rsm->r_no_rtt_allowed) {
9548 		/* Not allowed */
9549 		return (0);
9550 	}
9551 	if (ack_type == CUM_ACKED) {
9552 		if (SEQ_GT(th_ack, rsm->r_end)) {
9553 			len_acked = rsm->r_end - rsm->r_start;
9554 			all = 1;
9555 		} else {
9556 			len_acked = th_ack - rsm->r_start;
9557 			all = 0;
9558 		}
9559 	} else {
9560 		len_acked = rsm->r_end - rsm->r_start;
9561 		all = 0;
9562 	}
9563 	if (rsm->r_rtr_cnt == 1) {
9564 
9565 		t = cts - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
9566 		if ((int)t <= 0)
9567 			t = 1;
9568 		if (!tp->t_rttlow || tp->t_rttlow > t)
9569 			tp->t_rttlow = t;
9570 		if (!rack->r_ctl.rc_rack_min_rtt ||
9571 		    SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
9572 			rack->r_ctl.rc_rack_min_rtt = t;
9573 			if (rack->r_ctl.rc_rack_min_rtt == 0) {
9574 				rack->r_ctl.rc_rack_min_rtt = 1;
9575 			}
9576 		}
9577 		if (TSTMP_GT(tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time), rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]))
9578 			us_rtt = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
9579 		else
9580 			us_rtt = tcp_get_usecs(NULL) - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
9581 		if (us_rtt == 0)
9582 			us_rtt = 1;
9583 		if (CC_ALGO(tp)->rttsample != NULL) {
9584 			/* Kick the RTT to the CC */
9585 			CC_ALGO(tp)->rttsample(&tp->t_ccv, us_rtt, 1, rsm->r_fas);
9586 		}
9587 		rack_apply_updated_usrtt(rack, us_rtt, tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time));
9588 		if (ack_type == SACKED) {
9589 			rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)], cts, 1);
9590 			tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt, 2 , rsm, rsm->r_rtr_cnt);
9591 		} else {
9592 			/*
9593 			 * We need to setup what our confidence
9594 			 * is in this ack.
9595 			 *
9596 			 * If the rsm was app limited and it is
9597 			 * less than a mss in length (the end
9598 			 * of the send) then we have a gap. If we
9599 			 * were app limited but say we were sending
9600 			 * multiple MSS's then we are more confident
9601 			 * int it.
9602 			 *
9603 			 * When we are not app-limited then we see if
9604 			 * the rsm is being included in the current
9605 			 * measurement, we tell this by the app_limited_needs_set
9606 			 * flag.
9607 			 *
9608 			 * Note that being cwnd blocked is not applimited
9609 			 * as well as the pacing delay between packets which
9610 			 * are sending only 1 or 2 MSS's also will show up
9611 			 * in the RTT. We probably need to examine this algorithm
9612 			 * a bit more and enhance it to account for the delay
9613 			 * between rsm's. We could do that by saving off the
9614 			 * pacing delay of each rsm (in an rsm) and then
9615 			 * factoring that in somehow though for now I am
9616 			 * not sure how :)
9617 			 */
9618 			int calc_conf = 0;
9619 
9620 			if (rsm->r_flags & RACK_APP_LIMITED) {
9621 				if (all && (len_acked <= ctf_fixed_maxseg(tp)))
9622 					calc_conf = 0;
9623 				else
9624 					calc_conf = 1;
9625 			} else if (rack->app_limited_needs_set == 0) {
9626 				calc_conf = 1;
9627 			} else {
9628 				calc_conf = 0;
9629 			}
9630 			rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)], cts, 2);
9631 			tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt,
9632 					    calc_conf, rsm, rsm->r_rtr_cnt);
9633 		}
9634 		if ((rsm->r_flags & RACK_TLP) &&
9635 		    (!IN_FASTRECOVERY(tp->t_flags))) {
9636 			/* Segment was a TLP and our retrans matched */
9637 			if (rack->r_ctl.rc_tlp_cwnd_reduce) {
9638 				rack_cong_signal(tp, CC_NDUPACK, th_ack, __LINE__);
9639 			}
9640 		}
9641 		if ((rack->r_ctl.rc_rack_tmit_time == 0) ||
9642 		    (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
9643 			    (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]))) {
9644 			/* New more recent rack_tmit_time */
9645 			rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
9646 			if (rack->r_ctl.rc_rack_tmit_time == 0)
9647 				rack->r_ctl.rc_rack_tmit_time = 1;
9648 			rack->rc_rack_rtt = t;
9649 		}
9650 		return (1);
9651 	}
9652 	/*
9653 	 * We clear the soft/rxtshift since we got an ack.
9654 	 * There is no assurance we will call the commit() function
9655 	 * so we need to clear these to avoid incorrect handling.
9656 	 */
9657 	tp->t_rxtshift = 0;
9658 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
9659 		      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
9660 	tp->t_softerror = 0;
9661 	if (to && (to->to_flags & TOF_TS) &&
9662 	    (ack_type == CUM_ACKED) &&
9663 	    (to->to_tsecr) &&
9664 	    ((rsm->r_flags & RACK_OVERMAX) == 0)) {
9665 		/*
9666 		 * Now which timestamp does it match? In this block the ACK
9667 		 * must be coming from a previous transmission.
9668 		 */
9669 		for (i = 0; i < rsm->r_rtr_cnt; i++) {
9670 			if (rack_ts_to_msec(rsm->r_tim_lastsent[i]) == to->to_tsecr) {
9671 				t = cts - (uint32_t)rsm->r_tim_lastsent[i];
9672 				if ((int)t <= 0)
9673 					t = 1;
9674 				if (CC_ALGO(tp)->rttsample != NULL) {
9675 					/*
9676 					 * Kick the RTT to the CC, here
9677 					 * we lie a bit in that we know the
9678 					 * retransmission is correct even though
9679 					 * we retransmitted. This is because
9680 					 * we match the timestamps.
9681 					 */
9682 					if (TSTMP_GT(tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time), rsm->r_tim_lastsent[i]))
9683 						us_rtt = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - (uint32_t)rsm->r_tim_lastsent[i];
9684 					else
9685 						us_rtt = tcp_get_usecs(NULL) - (uint32_t)rsm->r_tim_lastsent[i];
9686 					CC_ALGO(tp)->rttsample(&tp->t_ccv, us_rtt, 1, rsm->r_fas);
9687 				}
9688 				if ((i + 1) < rsm->r_rtr_cnt) {
9689 					/*
9690 					 * The peer ack'd from our previous
9691 					 * transmission. We have a spurious
9692 					 * retransmission and thus we dont
9693 					 * want to update our rack_rtt.
9694 					 *
9695 					 * Hmm should there be a CC revert here?
9696 					 *
9697 					 */
9698 					return (0);
9699 				}
9700 				if (!tp->t_rttlow || tp->t_rttlow > t)
9701 					tp->t_rttlow = t;
9702 				if (!rack->r_ctl.rc_rack_min_rtt || SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
9703 					rack->r_ctl.rc_rack_min_rtt = t;
9704 					if (rack->r_ctl.rc_rack_min_rtt == 0) {
9705 						rack->r_ctl.rc_rack_min_rtt = 1;
9706 					}
9707 				}
9708 				if ((rack->r_ctl.rc_rack_tmit_time == 0) ||
9709 				    (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
9710 					    (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]))) {
9711 					/* New more recent rack_tmit_time */
9712 					rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
9713 					if (rack->r_ctl.rc_rack_tmit_time == 0)
9714 						rack->r_ctl.rc_rack_tmit_time = 1;
9715 					rack->rc_rack_rtt = t;
9716 				}
9717 				rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[i], cts, 3);
9718 				tcp_rack_xmit_timer(rack, t + 1, len_acked, t, 0, rsm,
9719 						    rsm->r_rtr_cnt);
9720 				return (1);
9721 			}
9722 		}
9723 		/* If we are logging log out the sendmap */
9724 		if (tcp_bblogging_on(rack->rc_tp)) {
9725 			for (i = 0; i < rsm->r_rtr_cnt; i++) {
9726 				rack_log_rtt_sendmap(rack, i, rsm->r_tim_lastsent[i], to->to_tsecr);
9727 			}
9728 		}
9729 		goto ts_not_found;
9730 	} else {
9731 		/*
9732 		 * Ok its a SACK block that we retransmitted. or a windows
9733 		 * machine without timestamps. We can tell nothing from the
9734 		 * time-stamp since its not there or the time the peer last
9735 		 * received a segment that moved forward its cum-ack point.
9736 		 */
9737 ts_not_found:
9738 		i = rsm->r_rtr_cnt - 1;
9739 		t = cts - (uint32_t)rsm->r_tim_lastsent[i];
9740 		if ((int)t <= 0)
9741 			t = 1;
9742 		if (rack->r_ctl.rc_rack_min_rtt && SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
9743 			/*
9744 			 * We retransmitted and the ack came back in less
9745 			 * than the smallest rtt we have observed. We most
9746 			 * likely did an improper retransmit as outlined in
9747 			 * 6.2 Step 2 point 2 in the rack-draft so we
9748 			 * don't want to update our rack_rtt. We in
9749 			 * theory (in future) might want to think about reverting our
9750 			 * cwnd state but we won't for now.
9751 			 */
9752 			return (0);
9753 		} else if (rack->r_ctl.rc_rack_min_rtt) {
9754 			/*
9755 			 * We retransmitted it and the retransmit did the
9756 			 * job.
9757 			 */
9758 			if (!rack->r_ctl.rc_rack_min_rtt ||
9759 			    SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
9760 				rack->r_ctl.rc_rack_min_rtt = t;
9761 				if (rack->r_ctl.rc_rack_min_rtt == 0) {
9762 					rack->r_ctl.rc_rack_min_rtt = 1;
9763 				}
9764 			}
9765 			if ((rack->r_ctl.rc_rack_tmit_time == 0) ||
9766 			    (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
9767 				    (uint32_t)rsm->r_tim_lastsent[i]))) {
9768 				/* New more recent rack_tmit_time */
9769 				rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[i];
9770 				if (rack->r_ctl.rc_rack_tmit_time == 0)
9771 					rack->r_ctl.rc_rack_tmit_time = 1;
9772 				rack->rc_rack_rtt = t;
9773 			}
9774 			return (1);
9775 		}
9776 	}
9777 	return (0);
9778 }
9779 
9780 /*
9781  * Mark the SACK_PASSED flag on all entries prior to rsm send wise.
9782  */
9783 static void
rack_log_sack_passed(struct tcpcb * tp,struct tcp_rack * rack,struct rack_sendmap * rsm,uint32_t cts)9784 rack_log_sack_passed(struct tcpcb *tp,
9785     struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t cts)
9786 {
9787 	struct rack_sendmap *nrsm;
9788 	uint32_t thresh;
9789 
9790 	/* Get our rxt threshold for lost consideration */
9791 	thresh = rack_calc_thresh_rack(rack, rack_grab_rtt(tp, rack), cts, __LINE__, 0);
9792 	/* Now start looking at rsm's */
9793 	nrsm = rsm;
9794 	TAILQ_FOREACH_REVERSE_FROM(nrsm, &rack->r_ctl.rc_tmap,
9795 	    rack_head, r_tnext) {
9796 		if (nrsm == rsm) {
9797 			/* Skip original segment he is acked */
9798 			continue;
9799 		}
9800 		if (nrsm->r_flags & RACK_ACKED) {
9801 			/*
9802 			 * Skip ack'd segments, though we
9803 			 * should not see these, since tmap
9804 			 * should not have ack'd segments.
9805 			 */
9806 			continue;
9807 		}
9808 		if (nrsm->r_flags & RACK_RWND_COLLAPSED) {
9809 			/*
9810 			 * If the peer dropped the rwnd on
9811 			 * these then we don't worry about them.
9812 			 */
9813 			continue;
9814 		}
9815 		/* Check lost state */
9816 		if ((nrsm->r_flags & RACK_WAS_LOST) == 0) {
9817 			uint32_t exp;
9818 
9819 			exp = ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]) + thresh;
9820 			if (TSTMP_LT(exp, cts) || (exp == cts)) {
9821 				/* We consider it lost */
9822 				nrsm->r_flags |= RACK_WAS_LOST;
9823 				rack->r_ctl.rc_considered_lost += nrsm->r_end - nrsm->r_start;
9824 			}
9825 		}
9826 		if (nrsm->r_flags & RACK_SACK_PASSED) {
9827 			/*
9828 			 * We found one that is already marked
9829 			 * passed, we have been here before and
9830 			 * so all others below this are marked.
9831 			 */
9832 			break;
9833 		}
9834 		nrsm->r_flags |= RACK_SACK_PASSED;
9835 		nrsm->r_flags &= ~RACK_WAS_SACKPASS;
9836 	}
9837 }
9838 
9839 static void
rack_need_set_test(struct tcpcb * tp,struct tcp_rack * rack,struct rack_sendmap * rsm,tcp_seq th_ack,int line,int use_which)9840 rack_need_set_test(struct tcpcb *tp,
9841 		   struct tcp_rack *rack,
9842 		   struct rack_sendmap *rsm,
9843 		   tcp_seq th_ack,
9844 		   int line,
9845 		   int use_which)
9846 {
9847 	struct rack_sendmap *s_rsm;
9848 
9849 	if ((tp->t_flags & TF_GPUTINPROG) &&
9850 	    SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
9851 		/*
9852 		 * We were app limited, and this ack
9853 		 * butts up or goes beyond the point where we want
9854 		 * to start our next measurement. We need
9855 		 * to record the new gput_ts as here and
9856 		 * possibly update the start sequence.
9857 		 */
9858 		uint32_t seq, ts;
9859 
9860 		if (rsm->r_rtr_cnt > 1) {
9861 			/*
9862 			 * This is a retransmit, can we
9863 			 * really make any assessment at this
9864 			 * point?  We are not really sure of
9865 			 * the timestamp, is it this or the
9866 			 * previous transmission?
9867 			 *
9868 			 * Lets wait for something better that
9869 			 * is not retransmitted.
9870 			 */
9871 			return;
9872 		}
9873 		seq = tp->gput_seq;
9874 		ts = tp->gput_ts;
9875 		rack->app_limited_needs_set = 0;
9876 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
9877 		/* Do we start at a new end? */
9878 		if ((use_which == RACK_USE_BEG) &&
9879 		    SEQ_GEQ(rsm->r_start, tp->gput_seq)) {
9880 			/*
9881 			 * When we get an ACK that just eats
9882 			 * up some of the rsm, we set RACK_USE_BEG
9883 			 * since whats at r_start (i.e. th_ack)
9884 			 * is left unacked and thats where the
9885 			 * measurement now starts.
9886 			 */
9887 			tp->gput_seq = rsm->r_start;
9888 		}
9889 		if ((use_which == RACK_USE_END) &&
9890 		    SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
9891 			/*
9892 			 * We use the end when the cumack
9893 			 * is moving forward and completely
9894 			 * deleting the rsm passed so basically
9895 			 * r_end holds th_ack.
9896 			 *
9897 			 * For SACK's we also want to use the end
9898 			 * since this piece just got sacked and
9899 			 * we want to target anything after that
9900 			 * in our measurement.
9901 			 */
9902 			tp->gput_seq = rsm->r_end;
9903 		}
9904 		if (use_which == RACK_USE_END_OR_THACK) {
9905 			/*
9906 			 * special case for ack moving forward,
9907 			 * not a sack, we need to move all the
9908 			 * way up to where this ack cum-ack moves
9909 			 * to.
9910 			 */
9911 			if (SEQ_GT(th_ack, rsm->r_end))
9912 				tp->gput_seq = th_ack;
9913 			else
9914 				tp->gput_seq = rsm->r_end;
9915 		}
9916 		if (SEQ_LT(tp->gput_seq, tp->snd_max))
9917 			s_rsm = tqhash_find(rack->r_ctl.tqh, tp->gput_seq);
9918 		else
9919 			s_rsm = NULL;
9920 		/*
9921 		 * Pick up the correct send time if we can the rsm passed in
9922 		 * may be equal to s_rsm if the RACK_USE_BEG was set. For the other
9923 		 * two cases (RACK_USE_THACK or RACK_USE_END) most likely we will
9924 		 * find a different seq i.e. the next send up.
9925 		 *
9926 		 * If that has not been sent, s_rsm will be NULL and we must
9927 		 * arrange it so this function will get called again by setting
9928 		 * app_limited_needs_set.
9929 		 */
9930 		if (s_rsm)
9931 			rack->r_ctl.rc_gp_output_ts = s_rsm->r_tim_lastsent[0];
9932 		else {
9933 			/* If we hit here we have to have *not* sent tp->gput_seq */
9934 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[0];
9935 			/* Set it up so we will go through here again */
9936 			rack->app_limited_needs_set = 1;
9937 		}
9938 		if (SEQ_GT(tp->gput_seq, tp->gput_ack)) {
9939 			/*
9940 			 * We moved beyond this guy's range, re-calculate
9941 			 * the new end point.
9942 			 */
9943 			if (rack->rc_gp_filled == 0) {
9944 				tp->gput_ack = tp->gput_seq + max(rc_init_window(rack), (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
9945 			} else {
9946 				tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
9947 			}
9948 		}
9949 		/*
9950 		 * We are moving the goal post, we may be able to clear the
9951 		 * measure_saw_probe_rtt flag.
9952 		 */
9953 		if ((rack->in_probe_rtt == 0) &&
9954 		    (rack->measure_saw_probe_rtt) &&
9955 		    (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
9956 			rack->measure_saw_probe_rtt = 0;
9957 		rack_log_pacing_delay_calc(rack, ts, tp->gput_ts,
9958 					   seq, tp->gput_seq,
9959 					   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) |
9960 					    (uint64_t)rack->r_ctl.rc_gp_output_ts),
9961 					   5, line, NULL, 0);
9962 		if (rack->rc_gp_filled &&
9963 		    ((tp->gput_ack - tp->gput_seq) <
9964 		     max(rc_init_window(rack), (MIN_GP_WIN *
9965 						ctf_fixed_maxseg(tp))))) {
9966 			uint32_t ideal_amount;
9967 
9968 			ideal_amount = rack_get_measure_window(tp, rack);
9969 			if (ideal_amount > sbavail(&tptosocket(tp)->so_snd)) {
9970 				/*
9971 				 * There is no sense of continuing this measurement
9972 				 * because its too small to gain us anything we
9973 				 * trust. Skip it and that way we can start a new
9974 				 * measurement quicker.
9975 				 */
9976 				tp->t_flags &= ~TF_GPUTINPROG;
9977 				rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
9978 							   0, 0,
9979 							   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) |
9980 							    (uint64_t)rack->r_ctl.rc_gp_output_ts),
9981 							   6, __LINE__, NULL, 0);
9982 			} else {
9983 				/*
9984 				 * Reset the window further out.
9985 				 */
9986 				tp->gput_ack = tp->gput_seq + ideal_amount;
9987 			}
9988 		}
9989 		rack_tend_gp_marks(tp, rack);
9990 		rack_log_gpset(rack, tp->gput_ack, 0, 0, line, 2, rsm);
9991 	}
9992 }
9993 
9994 static inline int
is_rsm_inside_declared_tlp_block(struct tcp_rack * rack,struct rack_sendmap * rsm)9995 is_rsm_inside_declared_tlp_block(struct tcp_rack *rack, struct rack_sendmap *rsm)
9996 {
9997 	if (SEQ_LT(rsm->r_end, rack->r_ctl.last_tlp_acked_start)) {
9998 		/* Behind our TLP definition or right at */
9999 		return (0);
10000 	}
10001 	if (SEQ_GT(rsm->r_start, rack->r_ctl.last_tlp_acked_end)) {
10002 		/* The start is beyond or right at our end of TLP definition */
10003 		return (0);
10004 	}
10005 	/* It has to be a sub-part of the original TLP recorded */
10006 	return (1);
10007 }
10008 
10009 static uint32_t
rack_proc_sack_blk(struct tcpcb * tp,struct tcp_rack * rack,struct sackblk * sack,struct tcpopt * to,struct rack_sendmap ** prsm,uint32_t cts,uint32_t segsiz)10010 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack, struct sackblk *sack,
10011 		   struct tcpopt *to, struct rack_sendmap **prsm, uint32_t cts,
10012 		   uint32_t segsiz)
10013 {
10014 	uint32_t start, end, changed = 0;
10015 	struct rack_sendmap stack_map;
10016 	struct rack_sendmap *rsm, *nrsm, *prev, *next;
10017 	int insret __diagused;
10018 	int32_t used_ref = 1;
10019 	int can_use_hookery = 0;
10020 
10021 	start = sack->start;
10022 	end = sack->end;
10023 	rsm = *prsm;
10024 
10025 do_rest_ofb:
10026 	if ((rsm == NULL) ||
10027 	    (SEQ_LT(end, rsm->r_start)) ||
10028 	    (SEQ_GEQ(start, rsm->r_end)) ||
10029 	    (SEQ_LT(start, rsm->r_start))) {
10030 		/*
10031 		 * We are not in the right spot,
10032 		 * find the correct spot in the tree.
10033 		 */
10034 		used_ref = 0;
10035 		rsm = tqhash_find(rack->r_ctl.tqh, start);
10036 	}
10037 	if (rsm == NULL) {
10038 		/* TSNH */
10039 		goto out;
10040 	}
10041 	/* Ok we have an ACK for some piece of this rsm */
10042 	if (rsm->r_start != start) {
10043 		if ((rsm->r_flags & RACK_ACKED) == 0) {
10044 			/*
10045 			 * Before any splitting or hookery is
10046 			 * done is it a TLP of interest i.e. rxt?
10047 			 */
10048 			if ((rsm->r_flags & RACK_TLP) &&
10049 			    (rsm->r_rtr_cnt > 1)) {
10050 				/*
10051 				 * We are splitting a rxt TLP, check
10052 				 * if we need to save off the start/end
10053 				 */
10054 				if (rack->rc_last_tlp_acked_set &&
10055 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
10056 					/*
10057 					 * We already turned this on since we are inside
10058 					 * the previous one was a partially sack now we
10059 					 * are getting another one (maybe all of it).
10060 					 *
10061 					 */
10062 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
10063 					/*
10064 					 * Lets make sure we have all of it though.
10065 					 */
10066 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
10067 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
10068 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
10069 								     rack->r_ctl.last_tlp_acked_end);
10070 					}
10071 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
10072 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
10073 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
10074 								     rack->r_ctl.last_tlp_acked_end);
10075 					}
10076 				} else {
10077 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
10078 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
10079 					rack->rc_last_tlp_past_cumack = 0;
10080 					rack->rc_last_tlp_acked_set = 1;
10081 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
10082 				}
10083 			}
10084 			/**
10085 			 * Need to split this in two pieces the before and after,
10086 			 * the before remains in the map, the after must be
10087 			 * added. In other words we have:
10088 			 * rsm        |--------------|
10089 			 * sackblk        |------->
10090 			 * rsm will become
10091 			 *     rsm    |---|
10092 			 * and nrsm will be  the sacked piece
10093 			 *     nrsm       |----------|
10094 			 *
10095 			 * But before we start down that path lets
10096 			 * see if the sack spans over on top of
10097 			 * the next guy and it is already sacked.
10098 			 *
10099 			 */
10100 			/*
10101 			 * Hookery can only be used if the two entries
10102 			 * are in the same bucket and neither one of
10103 			 * them staddle the bucket line.
10104 			 */
10105 			next = tqhash_next(rack->r_ctl.tqh, rsm);
10106 			if (next &&
10107 			    (rsm->bindex == next->bindex) &&
10108 			    ((rsm->r_flags & RACK_STRADDLE) == 0) &&
10109 			    ((next->r_flags & RACK_STRADDLE) == 0) &&
10110 			    ((rsm->r_flags & RACK_IS_PCM) == 0) &&
10111 			    ((next->r_flags & RACK_IS_PCM) == 0) &&
10112 			    (rsm->r_flags & RACK_IN_GP_WIN) &&
10113 			    (next->r_flags & RACK_IN_GP_WIN))
10114 				can_use_hookery = 1;
10115 			else
10116 				can_use_hookery = 0;
10117 			if (next && can_use_hookery &&
10118 			    (next->r_flags & RACK_ACKED) &&
10119 			    SEQ_GEQ(end, next->r_start)) {
10120 				/**
10121 				 * So the next one is already acked, and
10122 				 * we can thus by hookery use our stack_map
10123 				 * to reflect the piece being sacked and
10124 				 * then adjust the two tree entries moving
10125 				 * the start and ends around. So we start like:
10126 				 *  rsm     |------------|             (not-acked)
10127 				 *  next                 |-----------| (acked)
10128 				 *  sackblk        |-------->
10129 				 *  We want to end like so:
10130 				 *  rsm     |------|                   (not-acked)
10131 				 *  next           |-----------------| (acked)
10132 				 *  nrsm           |-----|
10133 				 * Where nrsm is a temporary stack piece we
10134 				 * use to update all the gizmos.
10135 				 */
10136 				/* Copy up our fudge block */
10137 				nrsm = &stack_map;
10138 				memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
10139 				/* Now adjust our tree blocks */
10140 				tqhash_update_end(rack->r_ctl.tqh, rsm, start);
10141 				next->r_start = start;
10142  				rsm->r_flags |= RACK_SHUFFLED;
10143 				next->r_flags |= RACK_SHUFFLED;
10144 				/* Now we must adjust back where next->m is */
10145 				rack_setup_offset_for_rsm(rack, rsm, next);
10146 				/*
10147 				 * Which timestamp do we keep? It is rather
10148 				 * important in GP measurements to have the
10149 				 * accurate end of the send window.
10150 				 *
10151 				 * We keep the largest value, which is the newest
10152 				 * send. We do this in case a segment that is
10153 				 * joined together and not part of a GP estimate
10154 				 * later gets expanded into the GP estimate.
10155 				 *
10156 				 * We prohibit the merging of unlike kinds i.e.
10157 				 * all pieces that are in the GP estimate can be
10158 				 * merged and all pieces that are not in a GP estimate
10159 				 * can be merged, but not disimilar pieces. Combine
10160 				 * this with taking the highest here and we should
10161 				 * be ok unless of course the client reneges. Then
10162 				 * all bets are off.
10163 				 */
10164 				if (next->r_tim_lastsent[(next->r_rtr_cnt-1)] <
10165 				    nrsm->r_tim_lastsent[(nrsm->r_rtr_cnt-1)])
10166 					next->r_tim_lastsent[(next->r_rtr_cnt-1)] = nrsm->r_tim_lastsent[(nrsm->r_rtr_cnt-1)];
10167 				/*
10168 				 * And we must keep the newest ack arrival time.
10169 				 */
10170 				if (next->r_ack_arrival <
10171 				    rack_to_usec_ts(&rack->r_ctl.act_rcv_time))
10172 					next->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
10173 
10174 
10175 				/* We don't need to adjust rsm, it did not change */
10176 				/* Clear out the dup ack count of the remainder */
10177 				rsm->r_dupack = 0;
10178 				rsm->r_just_ret = 0;
10179 				rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
10180 				/* Now lets make sure our fudge block is right */
10181 				nrsm->r_start = start;
10182 				/* Now lets update all the stats and such */
10183 				rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
10184 				if (rack->app_limited_needs_set)
10185 					rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
10186 				changed += (nrsm->r_end - nrsm->r_start);
10187 				rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
10188 				if (rsm->r_flags & RACK_WAS_LOST) {
10189 					int my_chg;
10190 
10191 					my_chg = (nrsm->r_end - nrsm->r_start);
10192 					KASSERT((rack->r_ctl.rc_considered_lost >= my_chg),
10193 						("rsm:%p rack:%p rc_considered_lost goes negative", rsm,  rack));
10194 					if (my_chg <= rack->r_ctl.rc_considered_lost)
10195 						rack->r_ctl.rc_considered_lost -= my_chg;
10196 					else
10197 						rack->r_ctl.rc_considered_lost = 0;
10198 				}
10199 				if (nrsm->r_flags & RACK_SACK_PASSED) {
10200 					rack->r_ctl.rc_reorder_ts = cts;
10201 					if (rack->r_ctl.rc_reorder_ts == 0)
10202 						rack->r_ctl.rc_reorder_ts = 1;
10203 				}
10204 				/*
10205 				 * Now we want to go up from rsm (the
10206 				 * one left un-acked) to the next one
10207 				 * in the tmap. We do this so when
10208 				 * we walk backwards we include marking
10209 				 * sack-passed on rsm (The one passed in
10210 				 * is skipped since it is generally called
10211 				 * on something sacked before removing it
10212 				 * from the tmap).
10213 				 */
10214 				if (rsm->r_in_tmap) {
10215 					nrsm = TAILQ_NEXT(rsm, r_tnext);
10216 					/*
10217 					 * Now that we have the next
10218 					 * one walk backwards from there.
10219 					 */
10220 					if (nrsm && nrsm->r_in_tmap)
10221 						rack_log_sack_passed(tp, rack, nrsm, cts);
10222 				}
10223 				/* Now are we done? */
10224 				if (SEQ_LT(end, next->r_end) ||
10225 				    (end == next->r_end)) {
10226 					/* Done with block */
10227 					goto out;
10228 				}
10229 				rack_log_map_chg(tp, rack, &stack_map, rsm, next, MAP_SACK_M1, end, __LINE__);
10230 				counter_u64_add(rack_sack_used_next_merge, 1);
10231 				/* Postion for the next block */
10232 				start = next->r_end;
10233 				rsm = tqhash_next(rack->r_ctl.tqh, next);
10234 				if (rsm == NULL)
10235 					goto out;
10236 			} else {
10237 				/**
10238 				 * We can't use any hookery here, so we
10239 				 * need to split the map. We enter like
10240 				 * so:
10241 				 *  rsm      |--------|
10242 				 *  sackblk       |----->
10243 				 * We will add the new block nrsm and
10244 				 * that will be the new portion, and then
10245 				 * fall through after reseting rsm. So we
10246 				 * split and look like this:
10247 				 *  rsm      |----|
10248 				 *  sackblk       |----->
10249 				 *  nrsm          |---|
10250 				 * We then fall through reseting
10251 				 * rsm to nrsm, so the next block
10252 				 * picks it up.
10253 				 */
10254 				nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
10255 				if (nrsm == NULL) {
10256 					/*
10257 					 * failed XXXrrs what can we do but loose the sack
10258 					 * info?
10259 					 */
10260 					goto out;
10261 				}
10262 				counter_u64_add(rack_sack_splits, 1);
10263 				rack_clone_rsm(rack, nrsm, rsm, start);
10264 				rsm->r_just_ret = 0;
10265 #ifndef INVARIANTS
10266 				(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
10267 #else
10268 				if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
10269 					panic("Insert in tailq_hash of %p fails ret:%d rack:%p rsm:%p",
10270 					      nrsm, insret, rack, rsm);
10271 				}
10272 #endif
10273 				if (rsm->r_in_tmap) {
10274 					TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
10275 					nrsm->r_in_tmap = 1;
10276 				}
10277 				rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SACK_M2, end, __LINE__);
10278 				rsm->r_flags &= (~RACK_HAS_FIN);
10279 				/* Position us to point to the new nrsm that starts the sack blk */
10280 				rsm = nrsm;
10281 			}
10282 		} else {
10283 			/* Already sacked this piece */
10284 			counter_u64_add(rack_sack_skipped_acked, 1);
10285 			if (end == rsm->r_end) {
10286 				/* Done with block */
10287 				rsm = tqhash_next(rack->r_ctl.tqh, rsm);
10288 				goto out;
10289 			} else if (SEQ_LT(end, rsm->r_end)) {
10290 				/* A partial sack to a already sacked block */
10291 				rsm = tqhash_next(rack->r_ctl.tqh, rsm);
10292 				goto out;
10293 			} else {
10294 				/*
10295 				 * The end goes beyond this guy
10296 				 * reposition the start to the
10297 				 * next block.
10298 				 */
10299 				start = rsm->r_end;
10300 				rsm = tqhash_next(rack->r_ctl.tqh, rsm);
10301 				if (rsm == NULL)
10302 					goto out;
10303 			}
10304 		}
10305 	}
10306 	if (SEQ_GEQ(end, rsm->r_end)) {
10307 		/**
10308 		 * The end of this block is either beyond this guy or right
10309 		 * at this guy. I.e.:
10310 		 *  rsm ---                 |-----|
10311 		 *  end                     |-----|
10312 		 *  <or>
10313 		 *  end                     |---------|
10314 		 */
10315 		if ((rsm->r_flags & RACK_ACKED) == 0) {
10316 			/*
10317 			 * Is it a TLP of interest?
10318 			 */
10319 			if ((rsm->r_flags & RACK_TLP) &&
10320 			    (rsm->r_rtr_cnt > 1)) {
10321 				/*
10322 				 * We are splitting a rxt TLP, check
10323 				 * if we need to save off the start/end
10324 				 */
10325 				if (rack->rc_last_tlp_acked_set &&
10326 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
10327 					/*
10328 					 * We already turned this on since we are inside
10329 					 * the previous one was a partially sack now we
10330 					 * are getting another one (maybe all of it).
10331 					 */
10332 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
10333 					/*
10334 					 * Lets make sure we have all of it though.
10335 					 */
10336 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
10337 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
10338 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
10339 								     rack->r_ctl.last_tlp_acked_end);
10340 					}
10341 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
10342 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
10343 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
10344 								     rack->r_ctl.last_tlp_acked_end);
10345 					}
10346 				} else {
10347 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
10348 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
10349 					rack->rc_last_tlp_past_cumack = 0;
10350 					rack->rc_last_tlp_acked_set = 1;
10351 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
10352 				}
10353 			}
10354 			rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
10355 			changed += (rsm->r_end - rsm->r_start);
10356 			/* You get a count for acking a whole segment or more */
10357 			if (rsm->r_flags & RACK_WAS_LOST) {
10358 				int my_chg;
10359 
10360 				my_chg = (rsm->r_end - rsm->r_start);
10361 				rsm->r_flags &= ~RACK_WAS_LOST;
10362 				KASSERT((rack->r_ctl.rc_considered_lost >= my_chg),
10363 					("rsm:%p rack:%p rc_considered_lost goes negative", rsm,  rack));
10364 				if (my_chg <= rack->r_ctl.rc_considered_lost)
10365 					rack->r_ctl.rc_considered_lost -= my_chg;
10366 				else
10367 					rack->r_ctl.rc_considered_lost = 0;
10368 			}
10369 			rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
10370 			if (rsm->r_in_tmap) /* should be true */
10371 				rack_log_sack_passed(tp, rack, rsm, cts);
10372 			/* Is Reordering occuring? */
10373 			if (rsm->r_flags & RACK_SACK_PASSED) {
10374 				rsm->r_flags &= ~RACK_SACK_PASSED;
10375 				rack->r_ctl.rc_reorder_ts = cts;
10376 				if (rack->r_ctl.rc_reorder_ts == 0)
10377 					rack->r_ctl.rc_reorder_ts = 1;
10378 			}
10379 			if (rack->app_limited_needs_set)
10380 				rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
10381 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
10382 			rsm->r_flags |= RACK_ACKED;
10383 			rack_update_pcm_ack(rack, 0, rsm->r_start, rsm->r_end);
10384 			if (rsm->r_in_tmap) {
10385 				TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
10386 				rsm->r_in_tmap = 0;
10387 			}
10388 			rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_SACK_M3, end, __LINE__);
10389 		} else {
10390 			counter_u64_add(rack_sack_skipped_acked, 1);
10391 		}
10392 		if (end == rsm->r_end) {
10393 			/* This block only - done, setup for next */
10394 			goto out;
10395 		}
10396 		/*
10397 		 * There is more not coverend by this rsm move on
10398 		 * to the next block in the tail queue hash table.
10399 		 */
10400 		nrsm = tqhash_next(rack->r_ctl.tqh, rsm);
10401 		start = rsm->r_end;
10402 		rsm = nrsm;
10403 		if (rsm == NULL)
10404 			goto out;
10405 		goto do_rest_ofb;
10406 	}
10407 	/**
10408 	 * The end of this sack block is smaller than
10409 	 * our rsm i.e.:
10410 	 *  rsm ---                 |-----|
10411 	 *  end                     |--|
10412 	 */
10413 	if ((rsm->r_flags & RACK_ACKED) == 0) {
10414 		/*
10415 		 * Is it a TLP of interest?
10416 		 */
10417 		if ((rsm->r_flags & RACK_TLP) &&
10418 		    (rsm->r_rtr_cnt > 1)) {
10419 			/*
10420 			 * We are splitting a rxt TLP, check
10421 			 * if we need to save off the start/end
10422 			 */
10423 			if (rack->rc_last_tlp_acked_set &&
10424 			    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
10425 				/*
10426 				 * We already turned this on since we are inside
10427 				 * the previous one was a partially sack now we
10428 				 * are getting another one (maybe all of it).
10429 				 */
10430 				rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
10431 				/*
10432 				 * Lets make sure we have all of it though.
10433 				 */
10434 				if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
10435 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
10436 					rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
10437 							     rack->r_ctl.last_tlp_acked_end);
10438 				}
10439 				if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
10440 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
10441 					rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
10442 							     rack->r_ctl.last_tlp_acked_end);
10443 				}
10444 			} else {
10445 				rack->r_ctl.last_tlp_acked_start = rsm->r_start;
10446 				rack->r_ctl.last_tlp_acked_end = rsm->r_end;
10447 				rack->rc_last_tlp_past_cumack = 0;
10448 				rack->rc_last_tlp_acked_set = 1;
10449 				rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
10450 			}
10451 		}
10452 		/*
10453 		 * Hookery can only be used if the two entries
10454 		 * are in the same bucket and neither one of
10455 		 * them staddle the bucket line.
10456 		 */
10457 		prev = tqhash_prev(rack->r_ctl.tqh, rsm);
10458 		if (prev &&
10459 		    (rsm->bindex == prev->bindex) &&
10460 		    ((rsm->r_flags & RACK_STRADDLE) == 0) &&
10461 		    ((prev->r_flags & RACK_STRADDLE) == 0) &&
10462 		    ((rsm->r_flags & RACK_IS_PCM) == 0) &&
10463 		    ((prev->r_flags & RACK_IS_PCM) == 0) &&
10464 		    (rsm->r_flags & RACK_IN_GP_WIN) &&
10465 		    (prev->r_flags & RACK_IN_GP_WIN))
10466 			can_use_hookery = 1;
10467 		else
10468 			can_use_hookery = 0;
10469 		if (prev && can_use_hookery &&
10470 		    (prev->r_flags & RACK_ACKED)) {
10471 			/**
10472 			 * Goal, we want the right remainder of rsm to shrink
10473 			 * in place and span from (rsm->r_start = end) to rsm->r_end.
10474 			 * We want to expand prev to go all the way
10475 			 * to prev->r_end <- end.
10476 			 * so in the tree we have before:
10477 			 *   prev     |--------|         (acked)
10478 			 *   rsm               |-------| (non-acked)
10479 			 *   sackblk           |-|
10480 			 * We churn it so we end up with
10481 			 *   prev     |----------|       (acked)
10482 			 *   rsm                 |-----| (non-acked)
10483 			 *   nrsm              |-| (temporary)
10484 			 *
10485 			 * Note if either prev/rsm is a TLP we don't
10486 			 * do this.
10487 			 */
10488 			nrsm = &stack_map;
10489 			memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
10490 			tqhash_update_end(rack->r_ctl.tqh, prev, end);
10491 			rsm->r_start = end;
10492 			rsm->r_flags |= RACK_SHUFFLED;
10493 			prev->r_flags |= RACK_SHUFFLED;
10494 			/* Now adjust nrsm (stack copy) to be
10495 			 * the one that is the small
10496 			 * piece that was "sacked".
10497 			 */
10498 			nrsm->r_end = end;
10499 			rsm->r_dupack = 0;
10500 			/*
10501 			 * Which timestamp do we keep? It is rather
10502 			 * important in GP measurements to have the
10503 			 * accurate end of the send window.
10504 			 *
10505 			 * We keep the largest value, which is the newest
10506 			 * send. We do this in case a segment that is
10507 			 * joined together and not part of a GP estimate
10508 			 * later gets expanded into the GP estimate.
10509 			 *
10510 			 * We prohibit the merging of unlike kinds i.e.
10511 			 * all pieces that are in the GP estimate can be
10512 			 * merged and all pieces that are not in a GP estimate
10513 			 * can be merged, but not disimilar pieces. Combine
10514 			 * this with taking the highest here and we should
10515 			 * be ok unless of course the client reneges. Then
10516 			 * all bets are off.
10517 			 */
10518 			if(prev->r_tim_lastsent[(prev->r_rtr_cnt-1)] <
10519 			   nrsm->r_tim_lastsent[(nrsm->r_rtr_cnt-1)]) {
10520 				prev->r_tim_lastsent[(prev->r_rtr_cnt-1)] = nrsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
10521 			}
10522 			/*
10523 			 * And we must keep the newest ack arrival time.
10524 			 */
10525 
10526 			if(prev->r_ack_arrival <
10527 			   rack_to_usec_ts(&rack->r_ctl.act_rcv_time))
10528 				prev->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
10529 
10530 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
10531 			/*
10532 			 * Now that the rsm has had its start moved forward
10533 			 * lets go ahead and get its new place in the world.
10534 			 */
10535 			rack_setup_offset_for_rsm(rack, prev, rsm);
10536 			/*
10537 			 * Now nrsm is our new little piece
10538 			 * that is acked (which was merged
10539 			 * to prev). Update the rtt and changed
10540 			 * based on that. Also check for reordering.
10541 			 */
10542 			rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
10543 			if (rack->app_limited_needs_set)
10544 				rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
10545 			changed += (nrsm->r_end - nrsm->r_start);
10546 			rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
10547 			if (rsm->r_flags & RACK_WAS_LOST) {
10548 				int my_chg;
10549 
10550 				my_chg = (nrsm->r_end - nrsm->r_start);
10551 				KASSERT((rack->r_ctl.rc_considered_lost >= my_chg),
10552 					("rsm:%p rack:%p rc_considered_lost goes negative", rsm,  rack));
10553 				if (my_chg <= rack->r_ctl.rc_considered_lost)
10554 					rack->r_ctl.rc_considered_lost -= my_chg;
10555 				else
10556 					rack->r_ctl.rc_considered_lost = 0;
10557 			}
10558 			if (nrsm->r_flags & RACK_SACK_PASSED) {
10559 				rack->r_ctl.rc_reorder_ts = cts;
10560 				if (rack->r_ctl.rc_reorder_ts == 0)
10561 					rack->r_ctl.rc_reorder_ts = 1;
10562 			}
10563 			rack_log_map_chg(tp, rack, prev, &stack_map, rsm, MAP_SACK_M4, end, __LINE__);
10564 			rsm = prev;
10565 			counter_u64_add(rack_sack_used_prev_merge, 1);
10566 		} else {
10567 			/**
10568 			 * This is the case where our previous
10569 			 * block is not acked either, so we must
10570 			 * split the block in two.
10571 			 */
10572 			nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
10573 			if (nrsm == NULL) {
10574 				/* failed rrs what can we do but loose the sack info? */
10575 				goto out;
10576 			}
10577 			if ((rsm->r_flags & RACK_TLP) &&
10578 			    (rsm->r_rtr_cnt > 1)) {
10579 				/*
10580 				 * We are splitting a rxt TLP, check
10581 				 * if we need to save off the start/end
10582 				 */
10583 				if (rack->rc_last_tlp_acked_set &&
10584 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
10585 					/*
10586 					 * We already turned this on since this block is inside
10587 					 * the previous one was a partially sack now we
10588 					 * are getting another one (maybe all of it).
10589 					 */
10590 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
10591 					/*
10592 					 * Lets make sure we have all of it though.
10593 					 */
10594 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
10595 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
10596 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
10597 								     rack->r_ctl.last_tlp_acked_end);
10598 					}
10599 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
10600 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
10601 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
10602 								     rack->r_ctl.last_tlp_acked_end);
10603 					}
10604 				} else {
10605 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
10606 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
10607 					rack->rc_last_tlp_acked_set = 1;
10608 					rack->rc_last_tlp_past_cumack = 0;
10609 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
10610 				}
10611 			}
10612 			/**
10613 			 * In this case nrsm becomes
10614 			 * nrsm->r_start = end;
10615 			 * nrsm->r_end = rsm->r_end;
10616 			 * which is un-acked.
10617 			 * <and>
10618 			 * rsm->r_end = nrsm->r_start;
10619 			 * i.e. the remaining un-acked
10620 			 * piece is left on the left
10621 			 * hand side.
10622 			 *
10623 			 * So we start like this
10624 			 * rsm      |----------| (not acked)
10625 			 * sackblk  |---|
10626 			 * build it so we have
10627 			 * rsm      |---|         (acked)
10628 			 * nrsm         |------|  (not acked)
10629 			 */
10630 			counter_u64_add(rack_sack_splits, 1);
10631 			rack_clone_rsm(rack, nrsm, rsm, end);
10632 			rsm->r_flags &= (~RACK_HAS_FIN);
10633 			rsm->r_just_ret = 0;
10634 #ifndef INVARIANTS
10635 			(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
10636 #else
10637 			if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
10638 				panic("Insert in tailq_hash of %p fails ret:% rack:%p rsm:%p",
10639 				      nrsm, insret, rack, rsm);
10640 			}
10641 #endif
10642 			if (rsm->r_in_tmap) {
10643 				TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
10644 				nrsm->r_in_tmap = 1;
10645 			}
10646 			nrsm->r_dupack = 0;
10647 			rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
10648 			rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
10649 			changed += (rsm->r_end - rsm->r_start);
10650 			if (rsm->r_flags & RACK_WAS_LOST) {
10651 				int my_chg;
10652 
10653 				my_chg = (rsm->r_end - rsm->r_start);
10654 				rsm->r_flags &= ~RACK_WAS_LOST;
10655 				KASSERT((rack->r_ctl.rc_considered_lost >= my_chg),
10656 					("rsm:%p rack:%p rc_considered_lost goes negative", rsm,  rack));
10657 				if (my_chg <= rack->r_ctl.rc_considered_lost)
10658 					rack->r_ctl.rc_considered_lost -= my_chg;
10659 				else
10660 					rack->r_ctl.rc_considered_lost = 0;
10661 			}
10662 			rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
10663 
10664 			if (rsm->r_in_tmap) /* should be true */
10665 				rack_log_sack_passed(tp, rack, rsm, cts);
10666 			/* Is Reordering occuring? */
10667 			if (rsm->r_flags & RACK_SACK_PASSED) {
10668 				rsm->r_flags &= ~RACK_SACK_PASSED;
10669 				rack->r_ctl.rc_reorder_ts = cts;
10670 				if (rack->r_ctl.rc_reorder_ts == 0)
10671 					rack->r_ctl.rc_reorder_ts = 1;
10672 			}
10673 			if (rack->app_limited_needs_set)
10674 				rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
10675 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
10676 			rsm->r_flags |= RACK_ACKED;
10677 			rack_update_pcm_ack(rack, 0, rsm->r_start, rsm->r_end);
10678 			rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SACK_M5, end, __LINE__);
10679 			if (rsm->r_in_tmap) {
10680 				TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
10681 				rsm->r_in_tmap = 0;
10682 			}
10683 		}
10684 	} else if (start != end){
10685 		/*
10686 		 * The block was already acked.
10687 		 */
10688 		counter_u64_add(rack_sack_skipped_acked, 1);
10689 	}
10690 out:
10691 	if (rsm &&
10692 	    ((rsm->r_flags & RACK_TLP) == 0) &&
10693 	    (rsm->r_flags & RACK_ACKED)) {
10694 		/*
10695 		 * Now can we merge where we worked
10696 		 * with either the previous or
10697 		 * next block?
10698 		 */
10699 		next = tqhash_next(rack->r_ctl.tqh, rsm);
10700 		while (next) {
10701 			if (next->r_flags & RACK_TLP)
10702 				break;
10703 			/* Only allow merges between ones in or out of GP window */
10704 			if ((next->r_flags & RACK_IN_GP_WIN) &&
10705 			    ((rsm->r_flags & RACK_IN_GP_WIN) == 0)) {
10706 				break;
10707 			}
10708 			if ((rsm->r_flags & RACK_IN_GP_WIN) &&
10709 			    ((next->r_flags & RACK_IN_GP_WIN) == 0)) {
10710 				break;
10711 			}
10712 			if (rsm->bindex != next->bindex)
10713 				break;
10714 			if (rsm->r_flags & RACK_STRADDLE)
10715 				break;
10716 			if (rsm->r_flags & RACK_IS_PCM)
10717 				break;
10718 			if (next->r_flags & RACK_STRADDLE)
10719 				break;
10720 			if (next->r_flags & RACK_IS_PCM)
10721 				break;
10722 			if (next->r_flags & RACK_ACKED) {
10723 				/* yep this and next can be merged */
10724 				rsm = rack_merge_rsm(rack, rsm, next);
10725 				next = tqhash_next(rack->r_ctl.tqh, rsm);
10726 			} else
10727 				break;
10728 		}
10729 		/* Now what about the previous? */
10730 		prev = tqhash_prev(rack->r_ctl.tqh, rsm);
10731 		while (prev) {
10732 			if (prev->r_flags & RACK_TLP)
10733 				break;
10734 			/* Only allow merges between ones in or out of GP window */
10735 			if ((prev->r_flags & RACK_IN_GP_WIN) &&
10736 			    ((rsm->r_flags & RACK_IN_GP_WIN) == 0)) {
10737 				break;
10738 			}
10739 			if ((rsm->r_flags & RACK_IN_GP_WIN) &&
10740 			    ((prev->r_flags & RACK_IN_GP_WIN) == 0)) {
10741 				break;
10742 			}
10743 			if (rsm->bindex != prev->bindex)
10744 				break;
10745 			if (rsm->r_flags & RACK_STRADDLE)
10746 				break;
10747 			if (rsm->r_flags & RACK_IS_PCM)
10748 				break;
10749 			if (prev->r_flags & RACK_STRADDLE)
10750 				break;
10751 			if (prev->r_flags & RACK_IS_PCM)
10752 				break;
10753 			if (prev->r_flags & RACK_ACKED) {
10754 				/* yep the previous and this can be merged */
10755 				rsm = rack_merge_rsm(rack, prev, rsm);
10756 				prev = tqhash_prev(rack->r_ctl.tqh, rsm);
10757 			} else
10758 				break;
10759 		}
10760 	}
10761 	if (used_ref == 0) {
10762 		counter_u64_add(rack_sack_proc_all, 1);
10763 	} else {
10764 		counter_u64_add(rack_sack_proc_short, 1);
10765 	}
10766 	/* Save off the next one for quick reference. */
10767 	nrsm = tqhash_find(rack->r_ctl.tqh, end);
10768 	*prsm = rack->r_ctl.rc_sacklast = nrsm;
10769 	if (IN_RECOVERY(tp->t_flags)) {
10770 		rack->r_ctl.bytes_acked_in_recovery += changed;
10771 	}
10772 	return (changed);
10773 }
10774 
10775 static void inline
rack_peer_reneges(struct tcp_rack * rack,struct rack_sendmap * rsm,tcp_seq th_ack)10776 rack_peer_reneges(struct tcp_rack *rack, struct rack_sendmap *rsm, tcp_seq th_ack)
10777 {
10778 	struct rack_sendmap *tmap;
10779 
10780 	tmap = NULL;
10781 	while (rsm && (rsm->r_flags & RACK_ACKED)) {
10782 		/* Its no longer sacked, mark it so */
10783 		rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
10784 #ifdef INVARIANTS
10785 		if (rsm->r_in_tmap) {
10786 			panic("rack:%p rsm:%p flags:0x%x in tmap?",
10787 			      rack, rsm, rsm->r_flags);
10788 		}
10789 #endif
10790 		rsm->r_flags &= ~(RACK_ACKED|RACK_SACK_PASSED|RACK_WAS_SACKPASS);
10791 		/* Rebuild it into our tmap */
10792 		if (tmap == NULL) {
10793 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
10794 			tmap = rsm;
10795 		} else {
10796 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, tmap, rsm, r_tnext);
10797 			tmap = rsm;
10798 		}
10799 		tmap->r_in_tmap = 1;
10800 		rsm = tqhash_next(rack->r_ctl.tqh, rsm);
10801 	}
10802 	/*
10803 	 * Now lets possibly clear the sack filter so we start
10804 	 * recognizing sacks that cover this area.
10805 	 */
10806 	sack_filter_clear(&rack->r_ctl.rack_sf, th_ack);
10807 
10808 }
10809 
10810 
10811 static void inline
rack_rsm_sender_update(struct tcp_rack * rack,struct tcpcb * tp,struct rack_sendmap * rsm,uint8_t from)10812 rack_rsm_sender_update(struct tcp_rack *rack, struct tcpcb *tp, struct rack_sendmap *rsm, uint8_t from)
10813 {
10814 	/*
10815 	 * We look at advancing the end send time for our GP
10816 	 * measurement tracking only as the cumulative acknowledgment
10817 	 * moves forward. You might wonder about this, why not
10818 	 * at every transmission or retransmission within the
10819 	 * GP window update the rc_gp_cumack_ts? Well its rather
10820 	 * nuanced but basically the GP window *may* expand (as
10821 	 * it does below) or worse and harder to track it may shrink.
10822 	 *
10823 	 * This last makes it impossible to track at the time of
10824 	 * the send, since you may set forward your rc_gp_cumack_ts
10825 	 * when you send, because that send *is* in your currently
10826 	 * "guessed" window, but then it shrinks. Now which was
10827 	 * the send time of the last bytes in the window, by the
10828 	 * time you ask that question that part of the sendmap
10829 	 * is freed. So you don't know and you will have too
10830 	 * long of send window. Instead by updating the time
10831 	 * marker only when the cumack advances this assures us
10832 	 * that we will have only the sends in the window of our
10833 	 * GP measurement.
10834 	 *
10835 	 * Another complication from this is the
10836 	 * merging of sendmap entries. During SACK processing this
10837 	 * can happen to conserve the sendmap size. That breaks
10838 	 * everything down in tracking the send window of the GP
10839 	 * estimate. So to prevent that and keep it working with
10840 	 * a tiny bit more limited merging, we only allow like
10841 	 * types to be merged. I.e. if two sends are in the GP window
10842 	 * then its ok to merge them together. If two sends are not
10843 	 * in the GP window its ok to merge them together too. Though
10844 	 * one send in and one send out cannot be merged. We combine
10845 	 * this with never allowing the shrinking of the GP window when
10846 	 * we are in recovery so that we can properly calculate the
10847 	 * sending times.
10848 	 *
10849 	 * This all of course seems complicated, because it is.. :)
10850 	 *
10851 	 * The cum-ack is being advanced upon the sendmap.
10852 	 * If we are not doing a GP estimate don't
10853 	 * proceed.
10854 	 */
10855 	uint64_t ts;
10856 
10857 	if ((tp->t_flags & TF_GPUTINPROG) == 0)
10858 		return;
10859 	/*
10860 	 * If this sendmap entry is going
10861 	 * beyond the measurement window we had picked,
10862 	 * expand the measurement window by that much.
10863 	 */
10864 	if (SEQ_GT(rsm->r_end, tp->gput_ack)) {
10865 		tp->gput_ack = rsm->r_end;
10866 	}
10867 	/*
10868 	 * If we have not setup a ack, then we
10869 	 * have no idea if the newly acked pieces
10870 	 * will be "in our seq measurement range". If
10871 	 * it is when we clear the app_limited_needs_set
10872 	 * flag the timestamp will be updated.
10873 	 */
10874 	if (rack->app_limited_needs_set)
10875 		return;
10876 	/*
10877 	 * Finally, we grab out the latest timestamp
10878 	 * that this packet was sent and then see
10879 	 * if:
10880 	 *  a) The packet touches are newly defined GP range.
10881 	 *  b) The time is greater than (newer) than the
10882 	 *     one we currently have. If so we update
10883 	 *     our sending end time window.
10884 	 *
10885 	 * Note we *do not* do this at send time. The reason
10886 	 * is that if you do you *may* pick up a newer timestamp
10887 	 * for a range you are not going to measure. We project
10888 	 * out how far and then sometimes modify that to be
10889 	 * smaller. If that occurs then you will have a send
10890 	 * that does not belong to the range included.
10891 	 */
10892 	if ((ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]) <=
10893 	    rack->r_ctl.rc_gp_cumack_ts)
10894 		return;
10895 	if (rack_in_gp_window(tp, rsm)) {
10896 		rack->r_ctl.rc_gp_cumack_ts = ts;
10897 		rack_log_gpset(rack, tp->gput_ack, (uint32_t)ts, rsm->r_end,
10898 			       __LINE__, from, rsm);
10899 	}
10900 }
10901 
10902 static void
rack_process_to_cumack(struct tcpcb * tp,struct tcp_rack * rack,register uint32_t th_ack,uint32_t cts,struct tcpopt * to,uint64_t acktime)10903 rack_process_to_cumack(struct tcpcb *tp, struct tcp_rack *rack, register uint32_t th_ack, uint32_t cts, struct tcpopt *to, uint64_t acktime)
10904 {
10905 	struct rack_sendmap *rsm;
10906 	/*
10907 	 * The ACK point is advancing to th_ack, we must drop off
10908 	 * the packets in the rack log and calculate any eligble
10909 	 * RTT's.
10910 	 */
10911 
10912 	if (sack_filter_blks_used(&rack->r_ctl.rack_sf)) {
10913 		/*
10914 		 * If we have some sack blocks in the filter
10915 		 * lets prune them out by calling sfb with no blocks.
10916 		 */
10917 		sack_filter_blks(tp, &rack->r_ctl.rack_sf, NULL, 0, th_ack);
10918 	}
10919 	if (SEQ_GT(th_ack, tp->snd_una)) {
10920 		/* Clear any app ack remembered settings */
10921 		rack->r_ctl.cleared_app_ack = 0;
10922 	}
10923 	rack->r_wanted_output = 1;
10924 	if (SEQ_GT(th_ack, tp->snd_una))
10925 		rack->r_ctl.last_cumack_advance = acktime;
10926 
10927 	/* Tend any TLP that has been marked for 1/2 the seq space (its old)  */
10928 	if ((rack->rc_last_tlp_acked_set == 1)&&
10929 	    (rack->rc_last_tlp_past_cumack == 1) &&
10930 	    (SEQ_GT(rack->r_ctl.last_tlp_acked_start, th_ack))) {
10931 		/*
10932 		 * We have reached the point where our last rack
10933 		 * tlp retransmit sequence is ahead of the cum-ack.
10934 		 * This can only happen when the cum-ack moves all
10935 		 * the way around (its been a full 2^^31+1 bytes
10936 		 * or more since we sent a retransmitted TLP). Lets
10937 		 * turn off the valid flag since its not really valid.
10938 		 *
10939 		 * Note since sack's also turn on this event we have
10940 		 * a complication, we have to wait to age it out until
10941 		 * the cum-ack is by the TLP before checking which is
10942 		 * what the next else clause does.
10943 		 */
10944 		rack_log_dsack_event(rack, 9, __LINE__,
10945 				     rack->r_ctl.last_tlp_acked_start,
10946 				     rack->r_ctl.last_tlp_acked_end);
10947 		rack->rc_last_tlp_acked_set = 0;
10948 		rack->rc_last_tlp_past_cumack = 0;
10949 	} else if ((rack->rc_last_tlp_acked_set == 1) &&
10950 		   (rack->rc_last_tlp_past_cumack == 0) &&
10951 		   (SEQ_GEQ(th_ack, rack->r_ctl.last_tlp_acked_end))) {
10952 		/*
10953 		 * It is safe to start aging TLP's out.
10954 		 */
10955 		rack->rc_last_tlp_past_cumack = 1;
10956 	}
10957 	/* We do the same for the tlp send seq as well */
10958 	if ((rack->rc_last_sent_tlp_seq_valid == 1) &&
10959 	    (rack->rc_last_sent_tlp_past_cumack == 1) &&
10960 	    (SEQ_GT(rack->r_ctl.last_sent_tlp_seq,  th_ack))) {
10961 		rack_log_dsack_event(rack, 9, __LINE__,
10962 				     rack->r_ctl.last_sent_tlp_seq,
10963 				     (rack->r_ctl.last_sent_tlp_seq +
10964 				      rack->r_ctl.last_sent_tlp_len));
10965 		rack->rc_last_sent_tlp_seq_valid = 0;
10966 		rack->rc_last_sent_tlp_past_cumack = 0;
10967 	} else if ((rack->rc_last_sent_tlp_seq_valid == 1) &&
10968 		   (rack->rc_last_sent_tlp_past_cumack == 0) &&
10969 		   (SEQ_GEQ(th_ack, rack->r_ctl.last_sent_tlp_seq))) {
10970 		/*
10971 		 * It is safe to start aging TLP's send.
10972 		 */
10973 		rack->rc_last_sent_tlp_past_cumack = 1;
10974 	}
10975 more:
10976 	rsm = tqhash_min(rack->r_ctl.tqh);
10977 	if (rsm == NULL) {
10978 		if ((th_ack - 1) == tp->iss) {
10979 			/*
10980 			 * For the SYN incoming case we will not
10981 			 * have called tcp_output for the sending of
10982 			 * the SYN, so there will be no map. All
10983 			 * other cases should probably be a panic.
10984 			 */
10985 			return;
10986 		}
10987 		if (tp->t_flags & TF_SENTFIN) {
10988 			/* if we sent a FIN we often will not have map */
10989 			return;
10990 		}
10991 #ifdef INVARIANTS
10992 		panic("No rack map tp:%p for state:%d ack:%u rack:%p snd_una:%u snd_max:%u\n",
10993 		      tp,
10994 		      tp->t_state, th_ack, rack,
10995 		      tp->snd_una, tp->snd_max);
10996 #endif
10997 		return;
10998 	}
10999 	if (SEQ_LT(th_ack, rsm->r_start)) {
11000 		/* Huh map is missing this */
11001 #ifdef INVARIANTS
11002 		printf("Rack map starts at r_start:%u for th_ack:%u huh? ts:%d rs:%d\n",
11003 		       rsm->r_start,
11004 		       th_ack, tp->t_state, rack->r_state);
11005 #endif
11006 		return;
11007 	}
11008 	rack_update_rtt(tp, rack, rsm, to, cts, CUM_ACKED, th_ack);
11009 
11010 	/* Now was it a retransmitted TLP? */
11011 	if ((rsm->r_flags & RACK_TLP) &&
11012 	    (rsm->r_rtr_cnt > 1)) {
11013 		/*
11014 		 * Yes, this rsm was a TLP and retransmitted, remember that
11015 		 * since if a DSACK comes back on this we don't want
11016 		 * to think of it as a reordered segment. This may
11017 		 * get updated again with possibly even other TLPs
11018 		 * in flight, but thats ok. Only when we don't send
11019 		 * a retransmitted TLP for 1/2 the sequences space
11020 		 * will it get turned off (above).
11021 		 */
11022 		if (rack->rc_last_tlp_acked_set &&
11023 		    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
11024 			/*
11025 			 * We already turned this on since the end matches,
11026 			 * the previous one was a partially ack now we
11027 			 * are getting another one (maybe all of it).
11028 			 */
11029 			rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
11030 			/*
11031 			 * Lets make sure we have all of it though.
11032 			 */
11033 			if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
11034 				rack->r_ctl.last_tlp_acked_start = rsm->r_start;
11035 				rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
11036 						     rack->r_ctl.last_tlp_acked_end);
11037 			}
11038 			if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
11039 				rack->r_ctl.last_tlp_acked_end = rsm->r_end;
11040 				rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
11041 						     rack->r_ctl.last_tlp_acked_end);
11042 			}
11043 		} else {
11044 			rack->rc_last_tlp_past_cumack = 1;
11045 			rack->r_ctl.last_tlp_acked_start = rsm->r_start;
11046 			rack->r_ctl.last_tlp_acked_end = rsm->r_end;
11047 			rack->rc_last_tlp_acked_set = 1;
11048 			rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
11049 		}
11050 	}
11051 	/* Now do we consume the whole thing? */
11052 	rack->r_ctl.last_tmit_time_acked = rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
11053 	if (SEQ_GEQ(th_ack, rsm->r_end)) {
11054 		/* Its all consumed. */
11055 		uint32_t left;
11056 		uint8_t newly_acked;
11057 
11058 		if (rsm->r_flags & RACK_WAS_LOST) {
11059 			/*
11060 			 * This can happen when we marked it as lost
11061 			 * and yet before retransmitting we get an ack
11062 			 * which can happen due to reordering.
11063 			 */
11064 			rsm->r_flags  &= ~RACK_WAS_LOST;
11065 			KASSERT((rack->r_ctl.rc_considered_lost >= (rsm->r_end - rsm->r_start)),
11066 				("rsm:%p rack:%p rc_considered_lost goes negative", rsm,  rack));
11067 			if (rack->r_ctl.rc_considered_lost >= (rsm->r_end - rsm->r_start))
11068 				rack->r_ctl.rc_considered_lost -= rsm->r_end - rsm->r_start;
11069 			else
11070 				rack->r_ctl.rc_considered_lost = 0;
11071 		}
11072 		rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_FREE, rsm->r_end, __LINE__);
11073 		rack->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
11074 		rsm->r_rtr_bytes = 0;
11075 		/*
11076 		 * Record the time of highest cumack sent if its in our measurement
11077 		 * window and possibly bump out the end.
11078 		 */
11079 		rack_rsm_sender_update(rack, tp, rsm, 4);
11080 		tqhash_remove(rack->r_ctl.tqh, rsm, REMOVE_TYPE_CUMACK);
11081 		if (rsm->r_in_tmap) {
11082 			TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
11083 			rsm->r_in_tmap = 0;
11084 		}
11085 		newly_acked = 1;
11086 		if (((rsm->r_flags & RACK_ACKED) == 0) &&
11087 		    (IN_RECOVERY(tp->t_flags))) {
11088 			rack->r_ctl.bytes_acked_in_recovery += (rsm->r_end - rsm->r_start);
11089 		}
11090 		if (rsm->r_flags & RACK_ACKED) {
11091 			/*
11092 			 * It was acked on the scoreboard -- remove
11093 			 * it from total
11094 			 */
11095 			rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
11096 			newly_acked = 0;
11097 		} else if (rsm->r_flags & RACK_SACK_PASSED) {
11098 			/*
11099 			 * There are segments ACKED on the
11100 			 * scoreboard further up. We are seeing
11101 			 * reordering.
11102 			 */
11103 			rsm->r_flags &= ~RACK_SACK_PASSED;
11104 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
11105 			rsm->r_flags |= RACK_ACKED;
11106 			rack->r_ctl.rc_reorder_ts = cts;
11107 			if (rack->r_ctl.rc_reorder_ts == 0)
11108 				rack->r_ctl.rc_reorder_ts = 1;
11109 			if (rack->r_ent_rec_ns) {
11110 				/*
11111 				 * We have sent no more, and we saw an sack
11112 				 * then ack arrive.
11113 				 */
11114 				rack->r_might_revert = 1;
11115 			}
11116 			rack_update_pcm_ack(rack, 1, rsm->r_start, rsm->r_end);
11117 		} else {
11118 			rack_update_pcm_ack(rack, 1, rsm->r_start, rsm->r_end);
11119 		}
11120 		if ((rsm->r_flags & RACK_TO_REXT) &&
11121 		    (tp->t_flags & TF_RCVD_TSTMP) &&
11122 		    (to->to_flags & TOF_TS) &&
11123 		    (to->to_tsecr != 0) &&
11124 		    (tp->t_flags & TF_PREVVALID)) {
11125 			/*
11126 			 * We can use the timestamp to see
11127 			 * if this retransmission was from the
11128 			 * first transmit. If so we made a mistake.
11129 			 */
11130 			tp->t_flags &= ~TF_PREVVALID;
11131 			if (to->to_tsecr == rack_ts_to_msec(rsm->r_tim_lastsent[0])) {
11132 				/* The first transmit is what this ack is for */
11133 				rack_cong_signal(tp, CC_RTO_ERR, th_ack, __LINE__);
11134 			}
11135 		}
11136 		left = th_ack - rsm->r_end;
11137 		if (rack->app_limited_needs_set && newly_acked)
11138 			rack_need_set_test(tp, rack, rsm, th_ack, __LINE__, RACK_USE_END_OR_THACK);
11139 		/* Free back to zone */
11140 		rack_free(rack, rsm);
11141 		if (left) {
11142 			goto more;
11143 		}
11144 		/* Check for reneging */
11145 		rsm = tqhash_min(rack->r_ctl.tqh);
11146 		if (rsm && (rsm->r_flags & RACK_ACKED) && (th_ack == rsm->r_start)) {
11147 			/*
11148 			 * The peer has moved snd_una up to
11149 			 * the edge of this send, i.e. one
11150 			 * that it had previously acked. The only
11151 			 * way that can be true if the peer threw
11152 			 * away data (space issues) that it had
11153 			 * previously sacked (else it would have
11154 			 * given us snd_una up to (rsm->r_end).
11155 			 * We need to undo the acked markings here.
11156 			 *
11157 			 * Note we have to look to make sure th_ack is
11158 			 * our rsm->r_start in case we get an old ack
11159 			 * where th_ack is behind snd_una.
11160 			 */
11161 			rack_peer_reneges(rack, rsm, th_ack);
11162 		}
11163 		return;
11164 	}
11165 	if (rsm->r_flags & RACK_ACKED) {
11166 		/*
11167 		 * It was acked on the scoreboard -- remove it from
11168 		 * total for the part being cum-acked.
11169 		 */
11170 		rack->r_ctl.rc_sacked -= (th_ack - rsm->r_start);
11171 	} else {
11172 		if (((rsm->r_flags & RACK_ACKED) == 0) &&
11173 		    (IN_RECOVERY(tp->t_flags))) {
11174 			rack->r_ctl.bytes_acked_in_recovery += (th_ack - rsm->r_start);
11175 		}
11176 		rack_update_pcm_ack(rack, 1, rsm->r_start, th_ack);
11177 	}
11178 	/* And what about the lost flag? */
11179 	if (rsm->r_flags & RACK_WAS_LOST) {
11180 		/*
11181 		 * This can happen when we marked it as lost
11182 		 * and yet before retransmitting we get an ack
11183 		 * which can happen due to reordering. In this
11184 		 * case its only a partial ack of the send.
11185 		 */
11186 		KASSERT((rack->r_ctl.rc_considered_lost >= (th_ack - rsm->r_start)),
11187 			("rsm:%p rack:%p rc_considered_lost goes negative th_ack:%u", rsm,  rack, th_ack));
11188 		if (rack->r_ctl.rc_considered_lost >= (th_ack - rsm->r_start))
11189 			rack->r_ctl.rc_considered_lost -= th_ack - rsm->r_start;
11190 		else
11191 			rack->r_ctl.rc_considered_lost = 0;
11192 	}
11193 	/*
11194 	 * Clear the dup ack count for
11195 	 * the piece that remains.
11196 	 */
11197 	rsm->r_dupack = 0;
11198 	rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
11199 	if (rsm->r_rtr_bytes) {
11200 		/*
11201 		 * It was retransmitted adjust the
11202 		 * sack holes for what was acked.
11203 		 */
11204 		int ack_am;
11205 
11206 		ack_am = (th_ack - rsm->r_start);
11207 		if (ack_am >= rsm->r_rtr_bytes) {
11208 			rack->r_ctl.rc_holes_rxt -= ack_am;
11209 			rsm->r_rtr_bytes -= ack_am;
11210 		}
11211 	}
11212 	/*
11213 	 * Update where the piece starts and record
11214 	 * the time of send of highest cumack sent if
11215 	 * its in our GP range.
11216 	 */
11217 	rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_TRIM_HEAD, th_ack, __LINE__);
11218 	/* Now we need to move our offset forward too */
11219 	if (rsm->m &&
11220 	    ((rsm->orig_m_len != rsm->m->m_len) ||
11221 	     (M_TRAILINGROOM(rsm->m) != rsm->orig_t_space))) {
11222 		/* Fix up the orig_m_len and possibly the mbuf offset */
11223 		rack_adjust_orig_mlen(rsm);
11224 	}
11225 	rsm->soff += (th_ack - rsm->r_start);
11226 	rack_rsm_sender_update(rack, tp, rsm, 5);
11227 	/* The trim will move th_ack into r_start for us */
11228 	tqhash_trim(rack->r_ctl.tqh, th_ack);
11229 	/* Now do we need to move the mbuf fwd too? */
11230 	{
11231 		struct mbuf *m;
11232 		uint32_t soff;
11233 
11234 		m = rsm->m;
11235 		soff = rsm->soff;
11236 		if (m) {
11237 			while (soff >= m->m_len) {
11238 				soff -= m->m_len;
11239 				KASSERT((m->m_next != NULL),
11240 					(" rsm:%p  off:%u soff:%u m:%p",
11241 					 rsm, rsm->soff, soff, m));
11242 				m = m->m_next;
11243 				if (m == NULL) {
11244 					/*
11245 					 * This is a fall-back that prevents a panic. In reality
11246 					 * we should be able to walk the mbuf's and find our place.
11247 					 * At this point snd_una has not been updated with the sbcut() yet
11248 					 * but tqhash_trim did update rsm->r_start so the offset calcuation
11249 					 * should work fine. This is undesirable since we will take cache
11250 					 * hits to access the socket buffer. And even more puzzling is that
11251 					 * it happens occasionally. It should not :(
11252 					 */
11253 					m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd,
11254 						      (rsm->r_start - tp->snd_una),
11255 						      &soff);
11256 					break;
11257 				}
11258 			}
11259 			/*
11260 			 * Now save in our updated values.
11261 			 */
11262 			rsm->m = m;
11263 			rsm->soff = soff;
11264 			rsm->orig_m_len = rsm->m->m_len;
11265 			rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
11266 		}
11267 	}
11268 	if (rack->app_limited_needs_set &&
11269 	    SEQ_GEQ(th_ack, tp->gput_seq))
11270 		rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_BEG);
11271 }
11272 
11273 static void
rack_handle_might_revert(struct tcpcb * tp,struct tcp_rack * rack)11274 rack_handle_might_revert(struct tcpcb *tp, struct tcp_rack *rack)
11275 {
11276 	struct rack_sendmap *rsm;
11277 	int sack_pass_fnd = 0;
11278 
11279 	if (rack->r_might_revert) {
11280 		/*
11281 		 * Ok we have reordering, have not sent anything, we
11282 		 * might want to revert the congestion state if nothing
11283 		 * further has SACK_PASSED on it. Lets check.
11284 		 *
11285 		 * We also get here when we have DSACKs come in for
11286 		 * all the data that we FR'd. Note that a rxt or tlp
11287 		 * timer clears this from happening.
11288 		 */
11289 
11290 		TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
11291 			if (rsm->r_flags & RACK_SACK_PASSED) {
11292 				sack_pass_fnd = 1;
11293 				break;
11294 			}
11295 		}
11296 		if (sack_pass_fnd == 0) {
11297 			/*
11298 			 * We went into recovery
11299 			 * incorrectly due to reordering!
11300 			 */
11301 			int orig_cwnd;
11302 
11303 			rack->r_ent_rec_ns = 0;
11304 			orig_cwnd = tp->snd_cwnd;
11305 			tp->snd_ssthresh = rack->r_ctl.rc_ssthresh_at_erec;
11306 			tp->snd_recover = tp->snd_una;
11307 			rack_log_to_prr(rack, 14, orig_cwnd, __LINE__);
11308 			if (IN_RECOVERY(tp->t_flags)) {
11309 				rack_exit_recovery(tp, rack, 3);
11310 				if ((rack->rto_from_rec == 1) && (rack_ssthresh_rest_rto_rec != 0) ){
11311 					/*
11312 					 * We were in recovery, had an RTO
11313 					 * and then re-entered recovery (more sack's arrived)
11314 					 * and we have properly recorded the old ssthresh from
11315 					 * the first recovery. We want to be able to slow-start
11316 					 * back to this level. The ssthresh from the timeout
11317 					 * and then back into recovery will end up most likely
11318 					 * to be min(cwnd=1mss, 2mss). Which makes it basically
11319 					 * so we get no slow-start after our RTO.
11320 					 */
11321 					rack->rto_from_rec = 0;
11322 					if (rack->r_ctl.rto_ssthresh > tp->snd_ssthresh)
11323 						tp->snd_ssthresh = rack->r_ctl.rto_ssthresh;
11324 				}
11325 			}
11326 			rack->r_ctl.bytes_acked_in_recovery = 0;
11327 			rack->r_ctl.time_entered_recovery = 0;
11328 		}
11329 		rack->r_might_revert = 0;
11330 	}
11331 }
11332 
11333 
11334 static int
rack_note_dsack(struct tcp_rack * rack,tcp_seq start,tcp_seq end)11335 rack_note_dsack(struct tcp_rack *rack, tcp_seq start, tcp_seq end)
11336 {
11337 
11338 	uint32_t am, l_end;
11339 	int was_tlp = 0;
11340 
11341 	if (SEQ_GT(end, start))
11342 		am = end - start;
11343 	else
11344 		am = 0;
11345 	if ((rack->rc_last_tlp_acked_set ) &&
11346 	    (SEQ_GEQ(start, rack->r_ctl.last_tlp_acked_start)) &&
11347 	    (SEQ_LEQ(end, rack->r_ctl.last_tlp_acked_end))) {
11348 		/*
11349 		 * The DSACK is because of a TLP which we don't
11350 		 * do anything with the reordering window over since
11351 		 * it was not reordering that caused the DSACK but
11352 		 * our previous retransmit TLP.
11353 		 */
11354 		rack_log_dsack_event(rack, 7, __LINE__, start, end);
11355 		was_tlp = 1;
11356 		goto skip_dsack_round;
11357 	}
11358 	if (rack->rc_last_sent_tlp_seq_valid) {
11359 		l_end = rack->r_ctl.last_sent_tlp_seq + rack->r_ctl.last_sent_tlp_len;
11360 		if (SEQ_GEQ(start, rack->r_ctl.last_sent_tlp_seq) &&
11361 		    (SEQ_LEQ(end, l_end))) {
11362 			/*
11363 			 * This dsack is from the last sent TLP, ignore it
11364 			 * for reordering purposes.
11365 			 */
11366 			rack_log_dsack_event(rack, 7, __LINE__, start, end);
11367 			was_tlp = 1;
11368 			goto skip_dsack_round;
11369 		}
11370 	}
11371 	if (rack->rc_dsack_round_seen == 0) {
11372 		rack->rc_dsack_round_seen = 1;
11373 		rack->r_ctl.dsack_round_end = rack->rc_tp->snd_max;
11374 		rack->r_ctl.num_dsack++;
11375 		rack->r_ctl.dsack_persist = 16;	/* 16 is from the standard */
11376 		rack_log_dsack_event(rack, 2, __LINE__, 0, 0);
11377 	}
11378 skip_dsack_round:
11379 	/*
11380 	 * We keep track of how many DSACK blocks we get
11381 	 * after a recovery incident.
11382 	 */
11383 	rack->r_ctl.dsack_byte_cnt += am;
11384 	if (!IN_FASTRECOVERY(rack->rc_tp->t_flags) &&
11385 	    rack->r_ctl.retran_during_recovery &&
11386 	    (rack->r_ctl.dsack_byte_cnt >= rack->r_ctl.retran_during_recovery)) {
11387 		/*
11388 		 * False recovery most likely culprit is reordering. If
11389 		 * nothing else is missing we need to revert.
11390 		 */
11391 		rack->r_might_revert = 1;
11392 		rack_handle_might_revert(rack->rc_tp, rack);
11393 		rack->r_might_revert = 0;
11394 		rack->r_ctl.retran_during_recovery = 0;
11395 		rack->r_ctl.dsack_byte_cnt = 0;
11396 	}
11397 	return (was_tlp);
11398 }
11399 
11400 static uint32_t
do_rack_compute_pipe(struct tcpcb * tp,struct tcp_rack * rack,uint32_t snd_una)11401 do_rack_compute_pipe(struct tcpcb *tp, struct tcp_rack *rack, uint32_t snd_una)
11402 {
11403 	return (((tp->snd_max - snd_una) -
11404 		 (rack->r_ctl.rc_sacked + rack->r_ctl.rc_considered_lost)) + rack->r_ctl.rc_holes_rxt);
11405 }
11406 
11407 static int32_t
rack_compute_pipe(struct tcpcb * tp)11408 rack_compute_pipe(struct tcpcb *tp)
11409 {
11410 	return ((int32_t)do_rack_compute_pipe(tp,
11411 					      (struct tcp_rack *)tp->t_fb_ptr,
11412 					      tp->snd_una));
11413 }
11414 
11415 static void
rack_update_prr(struct tcpcb * tp,struct tcp_rack * rack,uint32_t changed,tcp_seq th_ack)11416 rack_update_prr(struct tcpcb *tp, struct tcp_rack *rack, uint32_t changed, tcp_seq th_ack)
11417 {
11418 	/* Deal with changed and PRR here (in recovery only) */
11419 	uint32_t pipe, snd_una;
11420 
11421 	rack->r_ctl.rc_prr_delivered += changed;
11422 
11423 	if (sbavail(&rack->rc_inp->inp_socket->so_snd) <= (tp->snd_max - tp->snd_una)) {
11424 		/*
11425 		 * It is all outstanding, we are application limited
11426 		 * and thus we don't need more room to send anything.
11427 		 * Note we use tp->snd_una here and not th_ack because
11428 		 * the data as yet not been cut from the sb.
11429 		 */
11430 		rack->r_ctl.rc_prr_sndcnt = 0;
11431 		return;
11432 	}
11433 	/* Compute prr_sndcnt */
11434 	if (SEQ_GT(tp->snd_una, th_ack)) {
11435 		snd_una = tp->snd_una;
11436 	} else {
11437 		snd_una = th_ack;
11438 	}
11439 	pipe = do_rack_compute_pipe(tp, rack, snd_una);
11440 	if (pipe > tp->snd_ssthresh) {
11441 		long sndcnt;
11442 
11443 		sndcnt = rack->r_ctl.rc_prr_delivered * tp->snd_ssthresh;
11444 		if (rack->r_ctl.rc_prr_recovery_fs > 0)
11445 			sndcnt /= (long)rack->r_ctl.rc_prr_recovery_fs;
11446 		else {
11447 			rack->r_ctl.rc_prr_sndcnt = 0;
11448 			rack_log_to_prr(rack, 9, 0, __LINE__);
11449 			sndcnt = 0;
11450 		}
11451 		sndcnt++;
11452 		if (sndcnt > (long)rack->r_ctl.rc_prr_out)
11453 			sndcnt -= rack->r_ctl.rc_prr_out;
11454 		else
11455 			sndcnt = 0;
11456 		rack->r_ctl.rc_prr_sndcnt = sndcnt;
11457 		rack_log_to_prr(rack, 10, 0, __LINE__);
11458 	} else {
11459 		uint32_t limit;
11460 
11461 		if (rack->r_ctl.rc_prr_delivered > rack->r_ctl.rc_prr_out)
11462 			limit = (rack->r_ctl.rc_prr_delivered - rack->r_ctl.rc_prr_out);
11463 		else
11464 			limit = 0;
11465 		if (changed > limit)
11466 			limit = changed;
11467 		limit += ctf_fixed_maxseg(tp);
11468 		if (tp->snd_ssthresh > pipe) {
11469 			rack->r_ctl.rc_prr_sndcnt = min((tp->snd_ssthresh - pipe), limit);
11470 			rack_log_to_prr(rack, 11, 0, __LINE__);
11471 		} else {
11472 			rack->r_ctl.rc_prr_sndcnt = min(0, limit);
11473 			rack_log_to_prr(rack, 12, 0, __LINE__);
11474 		}
11475 	}
11476 }
11477 
11478 static void
rack_log_ack(struct tcpcb * tp,struct tcpopt * to,struct tcphdr * th,int entered_recovery,int dup_ack_struck,int * dsack_seen,int * sacks_seen)11479 rack_log_ack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th, int entered_recovery, int dup_ack_struck,
11480 	     int *dsack_seen, int *sacks_seen)
11481 {
11482 	uint32_t changed;
11483 	struct tcp_rack *rack;
11484 	struct rack_sendmap *rsm;
11485 	struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1];
11486 	register uint32_t th_ack;
11487 	int32_t i, j, k, num_sack_blks = 0;
11488 	uint32_t cts, acked, ack_point;
11489 	int loop_start = 0;
11490 	uint32_t tsused;
11491 	uint32_t segsiz;
11492 
11493 
11494 	INP_WLOCK_ASSERT(tptoinpcb(tp));
11495 	if (tcp_get_flags(th) & TH_RST) {
11496 		/* We don't log resets */
11497 		return;
11498 	}
11499 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11500 	cts = tcp_get_usecs(NULL);
11501 	rsm = tqhash_min(rack->r_ctl.tqh);
11502 	changed = 0;
11503 	th_ack = th->th_ack;
11504 	segsiz = ctf_fixed_maxseg(rack->rc_tp);
11505 	if (BYTES_THIS_ACK(tp, th) >=  segsiz) {
11506 		/*
11507 		 * You only get credit for
11508 		 * MSS and greater (and you get extra
11509 		 * credit for larger cum-ack moves).
11510 		 */
11511 		int ac;
11512 
11513 		ac = BYTES_THIS_ACK(tp, th) / ctf_fixed_maxseg(rack->rc_tp);
11514 		counter_u64_add(rack_ack_total, ac);
11515 	}
11516 	if (SEQ_GT(th_ack, tp->snd_una)) {
11517 		rack_log_progress_event(rack, tp, ticks, PROGRESS_UPDATE, __LINE__);
11518 		tp->t_acktime = ticks;
11519 	}
11520 	if (rsm && SEQ_GT(th_ack, rsm->r_start))
11521 		changed = th_ack - rsm->r_start;
11522 	if (changed) {
11523 		rack_process_to_cumack(tp, rack, th_ack, cts, to,
11524 				       tcp_tv_to_lusectick(&rack->r_ctl.act_rcv_time));
11525 	}
11526 	if ((to->to_flags & TOF_SACK) == 0) {
11527 		/* We are done nothing left and no sack. */
11528 		rack_handle_might_revert(tp, rack);
11529 		/*
11530 		 * For cases where we struck a dup-ack
11531 		 * with no SACK, add to the changes so
11532 		 * PRR will work right.
11533 		 */
11534 		if (dup_ack_struck && (changed == 0)) {
11535 			changed += ctf_fixed_maxseg(rack->rc_tp);
11536 		}
11537 		goto out;
11538 	}
11539 	/* Sack block processing */
11540 	if (SEQ_GT(th_ack, tp->snd_una))
11541 		ack_point = th_ack;
11542 	else
11543 		ack_point = tp->snd_una;
11544 	for (i = 0; i < to->to_nsacks; i++) {
11545 		bcopy((to->to_sacks + i * TCPOLEN_SACK),
11546 		      &sack, sizeof(sack));
11547 		sack.start = ntohl(sack.start);
11548 		sack.end = ntohl(sack.end);
11549 		if (SEQ_GT(sack.end, sack.start) &&
11550 		    SEQ_GT(sack.start, ack_point) &&
11551 		    SEQ_LT(sack.start, tp->snd_max) &&
11552 		    SEQ_GT(sack.end, ack_point) &&
11553 		    SEQ_LEQ(sack.end, tp->snd_max)) {
11554 			sack_blocks[num_sack_blks] = sack;
11555 			num_sack_blks++;
11556 		} else if (SEQ_LEQ(sack.start, th_ack) &&
11557 			   SEQ_LEQ(sack.end, th_ack)) {
11558 			int was_tlp;
11559 
11560 			if (dsack_seen != NULL)
11561 				*dsack_seen = 1;
11562 			was_tlp = rack_note_dsack(rack, sack.start, sack.end);
11563 			/*
11564 			 * Its a D-SACK block.
11565 			 */
11566 			tcp_record_dsack(tp, sack.start, sack.end, was_tlp);
11567 		}
11568 	}
11569 	if (rack->rc_dsack_round_seen) {
11570 		/* Is the dsack roound over? */
11571 		if (SEQ_GEQ(th_ack, rack->r_ctl.dsack_round_end)) {
11572 			/* Yes it is */
11573 			rack->rc_dsack_round_seen = 0;
11574 			rack_log_dsack_event(rack, 3, __LINE__, 0, 0);
11575 		}
11576 	}
11577 	/*
11578 	 * Sort the SACK blocks so we can update the rack scoreboard with
11579 	 * just one pass.
11580 	 */
11581 	num_sack_blks = sack_filter_blks(tp, &rack->r_ctl.rack_sf, sack_blocks,
11582 					 num_sack_blks, th->th_ack);
11583 	ctf_log_sack_filter(rack->rc_tp, num_sack_blks, sack_blocks);
11584 	if (sacks_seen != NULL)
11585 		*sacks_seen = num_sack_blks;
11586 	if (num_sack_blks == 0) {
11587 		/* Nothing to sack, but we need to update counts */
11588 		goto out_with_totals;
11589 	}
11590 	/* Its a sack of some sort */
11591 	if (num_sack_blks < 2) {
11592 		/* Only one, we don't need to sort */
11593 		goto do_sack_work;
11594 	}
11595 	/* Sort the sacks */
11596 	for (i = 0; i < num_sack_blks; i++) {
11597 		for (j = i + 1; j < num_sack_blks; j++) {
11598 			if (SEQ_GT(sack_blocks[i].end, sack_blocks[j].end)) {
11599 				sack = sack_blocks[i];
11600 				sack_blocks[i] = sack_blocks[j];
11601 				sack_blocks[j] = sack;
11602 			}
11603 		}
11604 	}
11605 	/*
11606 	 * Now are any of the sack block ends the same (yes some
11607 	 * implementations send these)?
11608 	 */
11609 again:
11610 	if (num_sack_blks == 0)
11611 		goto out_with_totals;
11612 	if (num_sack_blks > 1) {
11613 		for (i = 0; i < num_sack_blks; i++) {
11614 			for (j = i + 1; j < num_sack_blks; j++) {
11615 				if (sack_blocks[i].end == sack_blocks[j].end) {
11616 					/*
11617 					 * Ok these two have the same end we
11618 					 * want the smallest end and then
11619 					 * throw away the larger and start
11620 					 * again.
11621 					 */
11622 					if (SEQ_LT(sack_blocks[j].start, sack_blocks[i].start)) {
11623 						/*
11624 						 * The second block covers
11625 						 * more area use that
11626 						 */
11627 						sack_blocks[i].start = sack_blocks[j].start;
11628 					}
11629 					/*
11630 					 * Now collapse out the dup-sack and
11631 					 * lower the count
11632 					 */
11633 					for (k = (j + 1); k < num_sack_blks; k++) {
11634 						sack_blocks[j].start = sack_blocks[k].start;
11635 						sack_blocks[j].end = sack_blocks[k].end;
11636 						j++;
11637 					}
11638 					num_sack_blks--;
11639 					goto again;
11640 				}
11641 			}
11642 		}
11643 	}
11644 do_sack_work:
11645 	/*
11646 	 * First lets look to see if
11647 	 * we have retransmitted and
11648 	 * can use the transmit next?
11649 	 */
11650 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
11651 	if (rsm &&
11652 	    SEQ_GT(sack_blocks[0].end, rsm->r_start) &&
11653 	    SEQ_LT(sack_blocks[0].start, rsm->r_end)) {
11654 		/*
11655 		 * We probably did the FR and the next
11656 		 * SACK in continues as we would expect.
11657 		 */
11658 		acked = rack_proc_sack_blk(tp, rack, &sack_blocks[0], to, &rsm, cts, segsiz);
11659 		if (acked) {
11660 			rack->r_wanted_output = 1;
11661 			changed += acked;
11662 		}
11663 		if (num_sack_blks == 1) {
11664 			/*
11665 			 * This is what we would expect from
11666 			 * a normal implementation to happen
11667 			 * after we have retransmitted the FR,
11668 			 * i.e the sack-filter pushes down
11669 			 * to 1 block and the next to be retransmitted
11670 			 * is the sequence in the sack block (has more
11671 			 * are acked). Count this as ACK'd data to boost
11672 			 * up the chances of recovering any false positives.
11673 			 */
11674 			counter_u64_add(rack_ack_total, (acked / ctf_fixed_maxseg(rack->rc_tp)));
11675 			counter_u64_add(rack_express_sack, 1);
11676 			goto out_with_totals;
11677 		} else {
11678 			/*
11679 			 * Start the loop through the
11680 			 * rest of blocks, past the first block.
11681 			 */
11682 			loop_start = 1;
11683 		}
11684 	}
11685 	counter_u64_add(rack_sack_total, 1);
11686 	rsm = rack->r_ctl.rc_sacklast;
11687 	for (i = loop_start; i < num_sack_blks; i++) {
11688 		acked = rack_proc_sack_blk(tp, rack, &sack_blocks[i], to, &rsm, cts,  segsiz);
11689 		if (acked) {
11690 			rack->r_wanted_output = 1;
11691 			changed += acked;
11692 		}
11693 	}
11694 out_with_totals:
11695 	if (num_sack_blks > 1) {
11696 		/*
11697 		 * You get an extra stroke if
11698 		 * you have more than one sack-blk, this
11699 		 * could be where we are skipping forward
11700 		 * and the sack-filter is still working, or
11701 		 * it could be an attacker constantly
11702 		 * moving us.
11703 		 */
11704 		counter_u64_add(rack_move_some, 1);
11705 	}
11706 out:
11707 	if (changed) {
11708 		/* Something changed cancel the rack timer */
11709 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
11710 	}
11711 	tsused = tcp_get_usecs(NULL);
11712 	rsm = tcp_rack_output(tp, rack, tsused);
11713 	if ((!IN_FASTRECOVERY(tp->t_flags)) &&
11714 	    rsm &&
11715 	    ((rsm->r_flags & RACK_MUST_RXT) == 0)) {
11716 		/* Enter recovery */
11717 		entered_recovery = 1;
11718 		rack_cong_signal(tp, CC_NDUPACK, th_ack, __LINE__);
11719 		/*
11720 		 * When we enter recovery we need to assure we send
11721 		 * one packet.
11722 		 */
11723 		if (rack->rack_no_prr == 0) {
11724 			rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
11725 			rack_log_to_prr(rack, 8, 0, __LINE__);
11726 		}
11727 		rack->r_timer_override = 1;
11728 		rack->r_early = 0;
11729 		rack->r_ctl.rc_agg_early = 0;
11730 	} else if (IN_FASTRECOVERY(tp->t_flags) &&
11731 		   rsm &&
11732 		   (rack->r_rr_config == 3)) {
11733 		/*
11734 		 * Assure we can output and we get no
11735 		 * remembered pace time except the retransmit.
11736 		 */
11737 		rack->r_timer_override = 1;
11738 		rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
11739 		rack->r_ctl.rc_resend = rsm;
11740 	}
11741 	if (IN_FASTRECOVERY(tp->t_flags) &&
11742 	    (rack->rack_no_prr == 0) &&
11743 	    (entered_recovery == 0)) {
11744 		rack_update_prr(tp, rack, changed, th_ack);
11745 		if ((rsm && (rack->r_ctl.rc_prr_sndcnt >= ctf_fixed_maxseg(tp)) &&
11746 		     ((tcp_in_hpts(rack->rc_tp) == 0) &&
11747 		      ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)))) {
11748 			/*
11749 			 * If you are pacing output you don't want
11750 			 * to override.
11751 			 */
11752 			rack->r_early = 0;
11753 			rack->r_ctl.rc_agg_early = 0;
11754 			rack->r_timer_override = 1;
11755 		}
11756 	}
11757 }
11758 
11759 static void
rack_strike_dupack(struct tcp_rack * rack,tcp_seq th_ack)11760 rack_strike_dupack(struct tcp_rack *rack, tcp_seq th_ack)
11761 {
11762 	struct rack_sendmap *rsm;
11763 
11764 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
11765 	while (rsm) {
11766 		/*
11767 		 * We need to skip anything already set
11768 		 * to be retransmitted.
11769 		 */
11770 		if ((rsm->r_dupack >= DUP_ACK_THRESHOLD)  ||
11771 		    (rsm->r_flags & RACK_MUST_RXT)) {
11772 			rsm = TAILQ_NEXT(rsm, r_tnext);
11773 			continue;
11774 		}
11775 		break;
11776 	}
11777 	if (rsm && (rsm->r_dupack < 0xff)) {
11778 		rsm->r_dupack++;
11779 		if (rsm->r_dupack >= DUP_ACK_THRESHOLD) {
11780 			struct timeval tv;
11781 			uint32_t cts;
11782 			/*
11783 			 * Here we see if we need to retransmit. For
11784 			 * a SACK type connection if enough time has passed
11785 			 * we will get a return of the rsm. For a non-sack
11786 			 * connection we will get the rsm returned if the
11787 			 * dupack value is 3 or more.
11788 			 */
11789 			cts = tcp_get_usecs(&tv);
11790 			rack->r_ctl.rc_resend = tcp_rack_output(rack->rc_tp, rack, cts);
11791 			if (rack->r_ctl.rc_resend != NULL) {
11792 				if (!IN_FASTRECOVERY(rack->rc_tp->t_flags)) {
11793 					rack_cong_signal(rack->rc_tp, CC_NDUPACK,
11794 							 th_ack,  __LINE__);
11795 				}
11796 				rack->r_wanted_output = 1;
11797 				rack->r_timer_override = 1;
11798 				rack_log_retran_reason(rack, rsm, __LINE__, 1, 3);
11799 			}
11800 		} else {
11801 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 3);
11802 		}
11803 	}
11804 }
11805 
11806 static void
rack_check_bottom_drag(struct tcpcb * tp,struct tcp_rack * rack,struct socket * so)11807 rack_check_bottom_drag(struct tcpcb *tp,
11808 		       struct tcp_rack *rack,
11809 		       struct socket *so)
11810 {
11811 	/*
11812 	 * So what is dragging bottom?
11813 	 *
11814 	 * Dragging bottom means you were under pacing and had a
11815 	 * delay in processing inbound acks waiting on our pacing
11816 	 * timer to expire. While you were waiting all of the acknowledgments
11817 	 * for the packets you sent have arrived. This means we are pacing
11818 	 * way underneath the bottleneck to the point where our Goodput
11819 	 * measurements stop working, since they require more than one
11820 	 * ack (usually at least 8 packets worth with multiple acks so we can
11821 	 * gauge the inter-ack times). If that occurs we have a real problem
11822 	 * since we are stuck in a hole that we can't get out of without
11823 	 * something speeding us up.
11824 	 *
11825 	 * We also check to see if we are widdling down to just one segment
11826 	 * outstanding. If this occurs and we have room to send in our cwnd/rwnd
11827 	 * then we are adding the delayed ack interval into our measurments and
11828 	 * we need to speed up slightly.
11829 	 */
11830 	uint32_t segsiz, minseg;
11831 
11832 	segsiz = ctf_fixed_maxseg(tp);
11833 	minseg = segsiz;
11834 	if (tp->snd_max == tp->snd_una) {
11835 		/*
11836 		 * We are doing dynamic pacing and we are way
11837 		 * under. Basically everything got acked while
11838 		 * we were still waiting on the pacer to expire.
11839 		 *
11840 		 * This means we need to boost the b/w in
11841 		 * addition to any earlier boosting of
11842 		 * the multiplier.
11843 		 */
11844 		uint64_t lt_bw;
11845 
11846 		tcp_trace_point(rack->rc_tp, TCP_TP_PACED_BOTTOM);
11847 		lt_bw = rack_get_lt_bw(rack);
11848 		rack->rc_dragged_bottom = 1;
11849 		rack_validate_multipliers_at_or_above100(rack);
11850 		if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_VALID) &&
11851 		    (rack->dis_lt_bw == 0) &&
11852 		    (rack->use_lesser_lt_bw == 0) &&
11853 		    (lt_bw > 0)) {
11854 			/*
11855 			 * Lets use the long-term b/w we have
11856 			 * been getting as a base.
11857 			 */
11858 			if (rack->rc_gp_filled == 0) {
11859 				if (lt_bw > ONE_POINT_TWO_MEG) {
11860 					/*
11861 					 * If we have no measurement
11862 					 * don't let us set in more than
11863 					 * 1.2Mbps. If we are still too
11864 					 * low after pacing with this we
11865 					 * will hopefully have a max b/w
11866 					 * available to sanity check things.
11867 					 */
11868 					lt_bw = ONE_POINT_TWO_MEG;
11869 				}
11870 				rack->r_ctl.rc_rtt_diff = 0;
11871 				rack->r_ctl.gp_bw = lt_bw;
11872 				rack->rc_gp_filled = 1;
11873 				if (rack->r_ctl.num_measurements < RACK_REQ_AVG)
11874 					rack->r_ctl.num_measurements = RACK_REQ_AVG;
11875 				rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
11876 			} else if (lt_bw > rack->r_ctl.gp_bw) {
11877 				rack->r_ctl.rc_rtt_diff = 0;
11878 				if (rack->r_ctl.num_measurements < RACK_REQ_AVG)
11879 					rack->r_ctl.num_measurements = RACK_REQ_AVG;
11880 				rack->r_ctl.gp_bw = lt_bw;
11881 				rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
11882 			} else
11883 				rack_increase_bw_mul(rack, -1, 0, 0, 1);
11884 			if ((rack->gp_ready == 0) &&
11885 			    (rack->r_ctl.num_measurements >= rack->r_ctl.req_measurements)) {
11886 				/* We have enough measurements now */
11887 				rack->gp_ready = 1;
11888 				if (rack->dgp_on ||
11889 				    rack->rack_hibeta)
11890 					rack_set_cc_pacing(rack);
11891 				if (rack->defer_options)
11892 					rack_apply_deferred_options(rack);
11893 			}
11894 		} else {
11895 			/*
11896 			 * zero rtt possibly?, settle for just an old increase.
11897 			 */
11898 			rack_increase_bw_mul(rack, -1, 0, 0, 1);
11899 		}
11900 	} else if ((IN_FASTRECOVERY(tp->t_flags) == 0) &&
11901 		   (sbavail(&so->so_snd) > max((segsiz * (4 + rack_req_segs)),
11902 					       minseg)) &&
11903 		   (rack->r_ctl.cwnd_to_use > max((segsiz * (rack_req_segs + 2)), minseg)) &&
11904 		   (tp->snd_wnd > max((segsiz * (rack_req_segs + 2)), minseg)) &&
11905 		   (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) <=
11906 		    (segsiz * rack_req_segs))) {
11907 		/*
11908 		 * We are doing dynamic GP pacing and
11909 		 * we have everything except 1MSS or less
11910 		 * bytes left out. We are still pacing away.
11911 		 * And there is data that could be sent, This
11912 		 * means we are inserting delayed ack time in
11913 		 * our measurements because we are pacing too slow.
11914 		 */
11915 		rack_validate_multipliers_at_or_above100(rack);
11916 		rack->rc_dragged_bottom = 1;
11917 		rack_increase_bw_mul(rack, -1, 0, 0, 1);
11918 	}
11919 }
11920 
11921 #ifdef TCP_REQUEST_TRK
11922 static void
rack_log_hybrid(struct tcp_rack * rack,uint32_t seq,struct tcp_sendfile_track * cur,uint8_t mod,int line,int err)11923 rack_log_hybrid(struct tcp_rack *rack, uint32_t seq,
11924 		struct tcp_sendfile_track *cur, uint8_t mod, int line, int err)
11925 {
11926 	int do_log;
11927 
11928 	do_log = tcp_bblogging_on(rack->rc_tp);
11929 	if (do_log == 0) {
11930 		if ((do_log = tcp_bblogging_point_on(rack->rc_tp, TCP_BBPOINT_REQ_LEVEL_LOGGING) )== 0)
11931 			return;
11932 		/* We only allow the three below with point logging on */
11933 		if ((mod != HYBRID_LOG_RULES_APP) &&
11934 		    (mod != HYBRID_LOG_RULES_SET) &&
11935 		    (mod != HYBRID_LOG_REQ_COMP))
11936 			return;
11937 
11938 	}
11939 	if (do_log) {
11940 		union tcp_log_stackspecific log;
11941 		struct timeval tv;
11942 
11943 		/* Convert our ms to a microsecond */
11944 		memset(&log, 0, sizeof(log));
11945 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
11946 		log.u_bbr.flex1 = seq;
11947 		log.u_bbr.cwnd_gain = line;
11948 		if (cur != NULL) {
11949 			uint64_t off;
11950 
11951 			log.u_bbr.flex2 = cur->start_seq;
11952 			log.u_bbr.flex3 = cur->end_seq;
11953 			log.u_bbr.flex4 = (uint32_t)((cur->localtime >> 32) & 0x00000000ffffffff);
11954 			log.u_bbr.flex5 = (uint32_t)(cur->localtime & 0x00000000ffffffff);
11955 			log.u_bbr.flex6 = cur->flags;
11956 			log.u_bbr.pkts_out = cur->hybrid_flags;
11957 			log.u_bbr.rttProp = cur->timestamp;
11958 			log.u_bbr.cur_del_rate = cur->cspr;
11959 			log.u_bbr.bw_inuse = cur->start;
11960 			log.u_bbr.applimited = (uint32_t)(cur->end & 0x00000000ffffffff);
11961 			log.u_bbr.delivered = (uint32_t)((cur->end >> 32) & 0x00000000ffffffff) ;
11962 			log.u_bbr.epoch = (uint32_t)(cur->deadline & 0x00000000ffffffff);
11963 			log.u_bbr.lt_epoch = (uint32_t)((cur->deadline >> 32) & 0x00000000ffffffff) ;
11964 			log.u_bbr.inhpts = 1;
11965 #ifdef TCP_REQUEST_TRK
11966 			off = (uint64_t)(cur) - (uint64_t)(&rack->rc_tp->t_tcpreq_info[0]);
11967 			log.u_bbr.use_lt_bw = (uint8_t)(off / sizeof(struct tcp_sendfile_track));
11968 #endif
11969 		} else {
11970 			log.u_bbr.flex2 = err;
11971 		}
11972 		/*
11973 		 * Fill in flex7 to be CHD (catchup|hybrid|DGP)
11974 		 */
11975 		log.u_bbr.flex7 = rack->rc_catch_up;
11976 		log.u_bbr.flex7 <<= 1;
11977 		log.u_bbr.flex7 |= rack->rc_hybrid_mode;
11978 		log.u_bbr.flex7 <<= 1;
11979 		log.u_bbr.flex7 |= rack->dgp_on;
11980 		/*
11981 		 * Compose bbr_state to be a bit wise 0000ADHF
11982 		 * where A is the always_pace flag
11983 		 * where D is the dgp_on flag
11984 		 * where H is the hybrid_mode on flag
11985 		 * where F is the use_fixed_rate flag.
11986 		 */
11987 		log.u_bbr.bbr_state = rack->rc_always_pace;
11988 		log.u_bbr.bbr_state <<= 1;
11989 		log.u_bbr.bbr_state |= rack->dgp_on;
11990 		log.u_bbr.bbr_state <<= 1;
11991 		log.u_bbr.bbr_state |= rack->rc_hybrid_mode;
11992 		log.u_bbr.bbr_state <<= 1;
11993 		log.u_bbr.bbr_state |= rack->use_fixed_rate;
11994 		log.u_bbr.flex8 = mod;
11995 		log.u_bbr.delRate = rack->r_ctl.bw_rate_cap;
11996 		log.u_bbr.bbr_substate = rack->r_ctl.client_suggested_maxseg;
11997 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
11998 		log.u_bbr.pkt_epoch = rack->rc_tp->tcp_hybrid_start;
11999 		log.u_bbr.lost = rack->rc_tp->tcp_hybrid_error;
12000 		log.u_bbr.pacing_gain = (uint16_t)rack->rc_tp->tcp_hybrid_stop;
12001 		tcp_log_event(rack->rc_tp, NULL,
12002 		    &rack->rc_inp->inp_socket->so_rcv,
12003 		    &rack->rc_inp->inp_socket->so_snd,
12004 		    TCP_HYBRID_PACING_LOG, 0,
12005 	            0, &log, false, NULL, __func__, __LINE__, &tv);
12006 	}
12007 }
12008 #endif
12009 
12010 #ifdef TCP_REQUEST_TRK
12011 static void
rack_set_dgp_hybrid_mode(struct tcp_rack * rack,tcp_seq seq,uint32_t len,uint64_t cts)12012 rack_set_dgp_hybrid_mode(struct tcp_rack *rack, tcp_seq seq, uint32_t len, uint64_t cts)
12013 {
12014 	struct tcp_sendfile_track *rc_cur, *orig_ent;
12015 	struct tcpcb *tp;
12016 	int err = 0;
12017 
12018 	orig_ent = rack->r_ctl.rc_last_sft;
12019 	rc_cur = tcp_req_find_req_for_seq(rack->rc_tp, seq);
12020 	if (rc_cur == NULL) {
12021 		/* If not in the beginning what about the end piece */
12022 		if (rack->rc_hybrid_mode)
12023 			rack_log_hybrid(rack, seq, NULL, HYBRID_LOG_NO_RANGE, __LINE__, err);
12024 		rc_cur = tcp_req_find_req_for_seq(rack->rc_tp, (seq + len - 1));
12025 	} else {
12026 		err = 12345;
12027 	}
12028 	/* If we find no parameters we are in straight DGP mode */
12029 	if(rc_cur == NULL) {
12030 		/* None found for this seq, just DGP for now */
12031 		if (rack->rc_hybrid_mode) {
12032 			rack->r_ctl.client_suggested_maxseg = 0;
12033 			rack->rc_catch_up = 0;
12034 			if (rack->cspr_is_fcc == 0)
12035 				rack->r_ctl.bw_rate_cap = 0;
12036 			else
12037 				rack->r_ctl.fillcw_cap = rack_fillcw_bw_cap;
12038 		}
12039 		if (rack->rc_hybrid_mode) {
12040 			rack_log_hybrid(rack, (seq + len - 1), NULL, HYBRID_LOG_NO_RANGE, __LINE__, err);
12041 		}
12042 		if (rack->r_ctl.rc_last_sft) {
12043 			rack->r_ctl.rc_last_sft = NULL;
12044 		}
12045 		return;
12046 	}
12047 	if ((rc_cur->hybrid_flags & TCP_HYBRID_PACING_WASSET) == 0) {
12048 		/* This entry was never setup for hybrid pacing on/off etc */
12049 		if (rack->rc_hybrid_mode) {
12050 			rack->r_ctl.client_suggested_maxseg = 0;
12051 			rack->rc_catch_up = 0;
12052 			rack->r_ctl.bw_rate_cap = 0;
12053 		}
12054 		if (rack->r_ctl.rc_last_sft) {
12055 			rack->r_ctl.rc_last_sft = NULL;
12056 		}
12057 		if ((rc_cur->flags & TCP_TRK_TRACK_FLG_FSND) == 0) {
12058 			rc_cur->flags |= TCP_TRK_TRACK_FLG_FSND;
12059 			rc_cur->first_send = cts;
12060 			rc_cur->sent_at_fs = rack->rc_tp->t_sndbytes;
12061 			rc_cur->rxt_at_fs = rack->rc_tp->t_snd_rxt_bytes;
12062 		}
12063 		return;
12064 	}
12065 	/*
12066 	 * Ok if we have a new entry *or* have never
12067 	 * set up an entry we need to proceed. If
12068 	 * we have already set it up this entry we
12069 	 * just continue along with what we already
12070 	 * setup.
12071 	 */
12072 	tp = rack->rc_tp;
12073 	if ((rack->r_ctl.rc_last_sft != NULL) &&
12074 	    (rack->r_ctl.rc_last_sft == rc_cur)) {
12075 		/* Its already in place */
12076 		if (rack->rc_hybrid_mode)
12077 			rack_log_hybrid(rack, seq, rc_cur, HYBRID_LOG_ISSAME, __LINE__, 0);
12078 		return;
12079 	}
12080 	if (rack->rc_hybrid_mode == 0) {
12081 		rack->r_ctl.rc_last_sft = rc_cur;
12082 		if (orig_ent) {
12083 			orig_ent->sent_at_ls = rack->rc_tp->t_sndbytes;
12084 			orig_ent->rxt_at_ls = rack->rc_tp->t_snd_rxt_bytes;
12085 			orig_ent->flags |= TCP_TRK_TRACK_FLG_LSND;
12086 		}
12087 		rack_log_hybrid(rack, seq, rc_cur, HYBRID_LOG_RULES_APP, __LINE__, 0);
12088 		return;
12089 	}
12090 	if ((rc_cur->hybrid_flags & TCP_HYBRID_PACING_CSPR) && rc_cur->cspr){
12091 		/* Compensate for all the header overhead's */
12092 		if (rack->cspr_is_fcc == 0)
12093 			rack->r_ctl.bw_rate_cap	= rack_compensate_for_linerate(rack, rc_cur->cspr);
12094 		else
12095 			rack->r_ctl.fillcw_cap =  rack_compensate_for_linerate(rack, rc_cur->cspr);
12096 	} else {
12097 		if (rack->rc_hybrid_mode) {
12098 			if (rack->cspr_is_fcc == 0)
12099 				rack->r_ctl.bw_rate_cap = 0;
12100 			else
12101 				rack->r_ctl.fillcw_cap = rack_fillcw_bw_cap;
12102 		}
12103 	}
12104 	if (rc_cur->hybrid_flags & TCP_HYBRID_PACING_H_MS)
12105 		rack->r_ctl.client_suggested_maxseg = rc_cur->hint_maxseg;
12106 	else
12107 		rack->r_ctl.client_suggested_maxseg = 0;
12108 	if (rc_cur->timestamp == rack->r_ctl.last_tm_mark) {
12109 		/*
12110 		 * It is the same timestamp as the previous one
12111 		 * add the hybrid flag that will indicate we use
12112 		 * sendtime not arrival time for catch-up mode.
12113 		 */
12114 		rc_cur->hybrid_flags |= TCP_HYBRID_PACING_SENDTIME;
12115 	}
12116 	if ((rc_cur->hybrid_flags & TCP_HYBRID_PACING_CU) &&
12117 	    (rc_cur->cspr > 0)) {
12118 		uint64_t len;
12119 
12120 		rack->rc_catch_up = 1;
12121 		/*
12122 		 * Calculate the deadline time, first set the
12123 		 * time to when the request arrived.
12124 		 */
12125 		if (rc_cur->hybrid_flags & TCP_HYBRID_PACING_SENDTIME) {
12126 			/*
12127 			 * For cases where its a duplicate tm (we received more
12128 			 * than one request for a tm) we want to use now, the point
12129 			 * where we are just sending the first bit of the request.
12130 			 */
12131 			rc_cur->deadline = cts;
12132 		} else {
12133 			/*
12134 			 * Here we have a different tm from the last request
12135 			 * so we want to use arrival time as our base.
12136 			 */
12137 			rc_cur->deadline = rc_cur->localtime;
12138 		}
12139 		/*
12140 		 * Next calculate the length and compensate for
12141 		 * TLS if need be.
12142 		 */
12143 		len = rc_cur->end - rc_cur->start;
12144 		if (tp->t_inpcb.inp_socket->so_snd.sb_tls_info) {
12145 			/*
12146 			 * This session is doing TLS. Take a swag guess
12147 			 * at the overhead.
12148 			 */
12149 			len += tcp_estimate_tls_overhead(tp->t_inpcb.inp_socket, len);
12150 		}
12151 		/*
12152 		 * Now considering the size, and the cspr, what is the time that
12153 		 * would be required at the cspr rate. Here we use the raw
12154 		 * cspr value since the client only looks at the raw data. We
12155 		 * do use len which includes TLS overhead, but not the TCP/IP etc.
12156 		 * That will get made up for in the CU pacing rate set.
12157 		 */
12158 		len *= HPTS_USEC_IN_SEC;
12159 		len /= rc_cur->cspr;
12160 		rc_cur->deadline += len;
12161 	} else {
12162 		rack->rc_catch_up = 0;
12163 		rc_cur->deadline = 0;
12164 	}
12165 	if (rack->r_ctl.client_suggested_maxseg != 0) {
12166 		/*
12167 		 * We need to reset the max pace segs if we have a
12168 		 * client_suggested_maxseg.
12169 		 */
12170 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
12171 	}
12172 	if (orig_ent) {
12173 		orig_ent->sent_at_ls = rack->rc_tp->t_sndbytes;
12174 		orig_ent->rxt_at_ls = rack->rc_tp->t_snd_rxt_bytes;
12175 		orig_ent->flags |= TCP_TRK_TRACK_FLG_LSND;
12176 	}
12177 	rack_log_hybrid(rack, seq, rc_cur, HYBRID_LOG_RULES_APP, __LINE__, 0);
12178 	/* Remember it for next time and for CU mode */
12179 	rack->r_ctl.rc_last_sft = rc_cur;
12180 	rack->r_ctl.last_tm_mark = rc_cur->timestamp;
12181 }
12182 #endif
12183 
12184 static void
rack_chk_req_and_hybrid_on_out(struct tcp_rack * rack,tcp_seq seq,uint32_t len,uint64_t cts)12185 rack_chk_req_and_hybrid_on_out(struct tcp_rack *rack, tcp_seq seq, uint32_t len, uint64_t cts)
12186 {
12187 #ifdef TCP_REQUEST_TRK
12188 	struct tcp_sendfile_track *ent;
12189 
12190 	ent = rack->r_ctl.rc_last_sft;
12191 	if ((ent == NULL) ||
12192 	    (ent->flags == TCP_TRK_TRACK_FLG_EMPTY) ||
12193 	    (SEQ_GEQ(seq, ent->end_seq))) {
12194 		/* Time to update the track. */
12195 		rack_set_dgp_hybrid_mode(rack, seq, len, cts);
12196 		ent = rack->r_ctl.rc_last_sft;
12197 	}
12198 	/* Out of all */
12199 	if (ent == NULL) {
12200 		return;
12201 	}
12202 	if (SEQ_LT(ent->end_seq, (seq + len))) {
12203 		/*
12204 		 * This is the case where our end_seq guess
12205 		 * was wrong. This is usually due to TLS having
12206 		 * more bytes then our guess. It could also be the
12207 		 * case that the client sent in two requests closely
12208 		 * and the SB is full of both so we are sending part
12209 		 * of each (end|beg). In such a case lets move this
12210 		 * guys end to match the end of this send. That
12211 		 * way it will complete when all of it is acked.
12212 		 */
12213 		ent->end_seq = (seq + len);
12214 		if (rack->rc_hybrid_mode)
12215 			rack_log_hybrid_bw(rack, seq, len, 0, 0, HYBRID_LOG_EXTEND, 0, ent, __LINE__);
12216 	}
12217 	/* Now validate we have set the send time of this one */
12218 	if ((ent->flags & TCP_TRK_TRACK_FLG_FSND) == 0) {
12219 		ent->flags |= TCP_TRK_TRACK_FLG_FSND;
12220 		ent->first_send = cts;
12221 		ent->sent_at_fs = rack->rc_tp->t_sndbytes;
12222 		ent->rxt_at_fs = rack->rc_tp->t_snd_rxt_bytes;
12223 	}
12224 #endif
12225 }
12226 
12227 static void
rack_gain_for_fastoutput(struct tcp_rack * rack,struct tcpcb * tp,struct socket * so,uint32_t acked_amount)12228 rack_gain_for_fastoutput(struct tcp_rack *rack, struct tcpcb *tp, struct socket *so, uint32_t acked_amount)
12229 {
12230 	/*
12231 	 * The fast output path is enabled and we
12232 	 * have moved the cumack forward. Lets see if
12233 	 * we can expand forward the fast path length by
12234 	 * that amount. What we would ideally like to
12235 	 * do is increase the number of bytes in the
12236 	 * fast path block (left_to_send) by the
12237 	 * acked amount. However we have to gate that
12238 	 * by two factors:
12239 	 * 1) The amount outstanding and the rwnd of the peer
12240 	 *    (i.e. we don't want to exceed the rwnd of the peer).
12241 	 *    <and>
12242 	 * 2) The amount of data left in the socket buffer (i.e.
12243 	 *    we can't send beyond what is in the buffer).
12244 	 *
12245 	 * Note that this does not take into account any increase
12246 	 * in the cwnd. We will only extend the fast path by
12247 	 * what was acked.
12248 	 */
12249 	uint32_t new_total, gating_val;
12250 
12251 	new_total = acked_amount + rack->r_ctl.fsb.left_to_send;
12252 	gating_val = min((sbavail(&so->so_snd) - (tp->snd_max - tp->snd_una)),
12253 			 (tp->snd_wnd - (tp->snd_max - tp->snd_una)));
12254 	if (new_total <= gating_val) {
12255 		/* We can increase left_to_send by the acked amount */
12256 		counter_u64_add(rack_extended_rfo, 1);
12257 		rack->r_ctl.fsb.left_to_send = new_total;
12258 		KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(&rack->rc_inp->inp_socket->so_snd) - (tp->snd_max - tp->snd_una))),
12259 			("rack:%p left_to_send:%u sbavail:%u out:%u",
12260 			 rack, rack->r_ctl.fsb.left_to_send,
12261 			 sbavail(&rack->rc_inp->inp_socket->so_snd),
12262 			 (tp->snd_max - tp->snd_una)));
12263 
12264 	}
12265 }
12266 
12267 static void
rack_adjust_sendmap_head(struct tcp_rack * rack,struct sockbuf * sb)12268 rack_adjust_sendmap_head(struct tcp_rack *rack, struct sockbuf *sb)
12269 {
12270 	/*
12271 	 * Here any sendmap entry that points to the
12272 	 * beginning mbuf must be adjusted to the correct
12273 	 * offset. This must be called with:
12274 	 * 1) The socket buffer locked
12275 	 * 2) snd_una adjusted to its new position.
12276 	 *
12277 	 * Note that (2) implies rack_ack_received has also
12278 	 * been called and all the sbcut's have been done.
12279 	 *
12280 	 * We grab the first mbuf in the socket buffer and
12281 	 * then go through the front of the sendmap, recalculating
12282 	 * the stored offset for any sendmap entry that has
12283 	 * that mbuf. We must use the sb functions to do this
12284 	 * since its possible an add was done has well as
12285 	 * the subtraction we may have just completed. This should
12286 	 * not be a penalty though, since we just referenced the sb
12287 	 * to go in and trim off the mbufs that we freed (of course
12288 	 * there will be a penalty for the sendmap references though).
12289 	 *
12290 	 * Note also with INVARIANT on, we validate with a KASSERT
12291 	 * that the first sendmap entry has a soff of 0.
12292 	 *
12293 	 */
12294 	struct mbuf *m;
12295 	struct rack_sendmap *rsm;
12296 	tcp_seq snd_una;
12297 #ifdef INVARIANTS
12298 	int first_processed = 0;
12299 #endif
12300 
12301 	snd_una = rack->rc_tp->snd_una;
12302 	SOCKBUF_LOCK_ASSERT(sb);
12303 	m = sb->sb_mb;
12304 	rsm = tqhash_min(rack->r_ctl.tqh);
12305 	if ((rsm == NULL) || (m == NULL)) {
12306 		/* Nothing outstanding */
12307 		return;
12308 	}
12309 	/* The very first RSM's mbuf must point to the head mbuf in the sb */
12310 	KASSERT((rsm->m == m),
12311 		("Rack:%p sb:%p rsm:%p -- first rsm mbuf not aligned to sb",
12312 		 rack, sb, rsm));
12313 	while (rsm->m && (rsm->m == m)) {
12314 		/* one to adjust */
12315 #ifdef INVARIANTS
12316 		struct mbuf *tm;
12317 		uint32_t soff;
12318 
12319 		tm = sbsndmbuf(sb, (rsm->r_start - snd_una), &soff);
12320 		if ((rsm->orig_m_len != m->m_len) ||
12321 		    (rsm->orig_t_space != M_TRAILINGROOM(m))){
12322 			rack_adjust_orig_mlen(rsm);
12323 		}
12324 		if (first_processed == 0) {
12325 			KASSERT((rsm->soff == 0),
12326 				("Rack:%p rsm:%p -- rsm at head but soff not zero",
12327 				 rack, rsm));
12328 			first_processed = 1;
12329 		}
12330 		if ((rsm->soff != soff) || (rsm->m != tm)) {
12331 			/*
12332 			 * This is not a fatal error, we anticipate it
12333 			 * might happen (the else code), so we count it here
12334 			 * so that under invariant we can see that it really
12335 			 * does happen.
12336 			 */
12337 			counter_u64_add(rack_adjust_map_bw, 1);
12338 		}
12339 		rsm->m = tm;
12340 		rsm->soff = soff;
12341 		if (tm) {
12342 			rsm->orig_m_len = rsm->m->m_len;
12343 			rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
12344 		} else {
12345 			rsm->orig_m_len = 0;
12346 			rsm->orig_t_space = 0;
12347 		}
12348 #else
12349 		rsm->m = sbsndmbuf(sb, (rsm->r_start - snd_una), &rsm->soff);
12350 		if (rsm->m) {
12351 			rsm->orig_m_len = rsm->m->m_len;
12352 			rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
12353 		} else {
12354 			rsm->orig_m_len = 0;
12355 			rsm->orig_t_space = 0;
12356 		}
12357 #endif
12358 		rsm = tqhash_next(rack->r_ctl.tqh, rsm);
12359 		if (rsm == NULL)
12360 			break;
12361 	}
12362 }
12363 
12364 #ifdef TCP_REQUEST_TRK
12365 static inline void
rack_req_check_for_comp(struct tcp_rack * rack,tcp_seq th_ack)12366 rack_req_check_for_comp(struct tcp_rack *rack, tcp_seq th_ack)
12367 {
12368 	struct tcp_sendfile_track *ent;
12369 	int i;
12370 
12371 	if ((rack->rc_hybrid_mode == 0) &&
12372 	    (tcp_bblogging_point_on(rack->rc_tp, TCP_BBPOINT_REQ_LEVEL_LOGGING) == 0)) {
12373 		/*
12374 		 * Just do normal completions hybrid pacing is not on
12375 		 * and CLDL is off as well.
12376 		 */
12377 		tcp_req_check_for_comp(rack->rc_tp, th_ack);
12378 		return;
12379 	}
12380 	/*
12381 	 * Originally I was just going to find the th_ack associated
12382 	 * with an entry. But then I realized a large strech ack could
12383 	 * in theory ack two or more requests at once. So instead we
12384 	 * need to find all entries that are completed by th_ack not
12385 	 * just a single entry and do our logging.
12386 	 */
12387 	ent = tcp_req_find_a_req_that_is_completed_by(rack->rc_tp, th_ack, &i);
12388 	while (ent != NULL) {
12389 		/*
12390 		 * We may be doing hybrid pacing or CLDL and need more details possibly
12391 		 * so we do it manually instead of calling
12392 		 * tcp_req_check_for_comp()
12393 		 */
12394 		uint64_t laa, tim, data, cbw, ftim;
12395 
12396 		/* Ok this ack frees it */
12397 		rack_log_hybrid(rack, th_ack,
12398 				ent, HYBRID_LOG_REQ_COMP, __LINE__, 0);
12399 		rack_log_hybrid_sends(rack, ent, __LINE__);
12400 		/* calculate the time based on the ack arrival */
12401 		data = ent->end - ent->start;
12402 		laa = tcp_tv_to_lusectick(&rack->r_ctl.act_rcv_time);
12403 		if (ent->flags & TCP_TRK_TRACK_FLG_FSND) {
12404 			if (ent->first_send > ent->localtime)
12405 				ftim = ent->first_send;
12406 			else
12407 				ftim = ent->localtime;
12408 		} else {
12409 			/* TSNH */
12410 			ftim = ent->localtime;
12411 		}
12412 		if (laa > ent->localtime)
12413 			tim = laa - ftim;
12414 		else
12415 			tim = 0;
12416 		cbw = data * HPTS_USEC_IN_SEC;
12417 		if (tim > 0)
12418 			cbw /= tim;
12419 		else
12420 			cbw = 0;
12421 		rack_log_hybrid_bw(rack, th_ack, cbw, tim, data, HYBRID_LOG_BW_MEASURE, 0, ent, __LINE__);
12422 		/*
12423 		 * Check to see if we are freeing what we are pointing to send wise
12424 		 * if so be sure to NULL the pointer so we know we are no longer
12425 		 * set to anything.
12426 		 */
12427 		if (ent == rack->r_ctl.rc_last_sft) {
12428 			rack->r_ctl.rc_last_sft = NULL;
12429 			if (rack->rc_hybrid_mode) {
12430 				rack->rc_catch_up = 0;
12431 				if (rack->cspr_is_fcc == 0)
12432 					rack->r_ctl.bw_rate_cap = 0;
12433 				else
12434 					rack->r_ctl.fillcw_cap = rack_fillcw_bw_cap;
12435 				rack->r_ctl.client_suggested_maxseg = 0;
12436 			}
12437 		}
12438 		/* Generate the log that the tcp_netflix call would have */
12439 		tcp_req_log_req_info(rack->rc_tp, ent,
12440 				      i, TCP_TRK_REQ_LOG_FREED, 0, 0);
12441 		/* Free it and see if there is another one */
12442 		tcp_req_free_a_slot(rack->rc_tp, ent);
12443 		ent = tcp_req_find_a_req_that_is_completed_by(rack->rc_tp, th_ack, &i);
12444 	}
12445 }
12446 #endif
12447 
12448 
12449 /*
12450  * Return value of 1, we do not need to call rack_process_data().
12451  * return value of 0, rack_process_data can be called.
12452  * For ret_val if its 0 the TCP is locked, if its non-zero
12453  * its unlocked and probably unsafe to touch the TCB.
12454  */
12455 static int
rack_process_ack(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,uint32_t tiwin,int32_t tlen,int32_t * ofia,int32_t thflags,int32_t * ret_val,int32_t orig_tlen)12456 rack_process_ack(struct mbuf *m, struct tcphdr *th, struct socket *so,
12457     struct tcpcb *tp, struct tcpopt *to,
12458     uint32_t tiwin, int32_t tlen,
12459     int32_t * ofia, int32_t thflags, int32_t *ret_val, int32_t orig_tlen)
12460 {
12461 	int32_t ourfinisacked = 0;
12462 	int32_t nsegs, acked_amount;
12463 	int32_t acked;
12464 	struct mbuf *mfree;
12465 	struct tcp_rack *rack;
12466 	int32_t under_pacing = 0;
12467 	int32_t post_recovery = 0;
12468 	uint32_t p_cwnd;
12469 
12470 	INP_WLOCK_ASSERT(tptoinpcb(tp));
12471 
12472 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12473 	if (SEQ_GT(th->th_ack, tp->snd_max)) {
12474 		__ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val,
12475 				      &rack->r_ctl.challenge_ack_ts,
12476 				      &rack->r_ctl.challenge_ack_cnt);
12477 		rack->r_wanted_output = 1;
12478 		return (1);
12479 	}
12480 	if (rack->gp_ready &&
12481 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
12482 		under_pacing = 1;
12483 	}
12484 	if (SEQ_GEQ(th->th_ack, tp->snd_una) || to->to_nsacks) {
12485 		int in_rec, dup_ack_struck = 0;
12486 		int dsack_seen = 0, sacks_seen = 0;
12487 
12488 		in_rec = IN_FASTRECOVERY(tp->t_flags);
12489 		if (rack->rc_in_persist) {
12490 			tp->t_rxtshift = 0;
12491 			RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
12492 				      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
12493 		}
12494 
12495 		if ((th->th_ack == tp->snd_una) &&
12496 		    (tiwin == tp->snd_wnd) &&
12497 		    (orig_tlen == 0) &&
12498 		    ((to->to_flags & TOF_SACK) == 0)) {
12499 			rack_strike_dupack(rack, th->th_ack);
12500 			dup_ack_struck = 1;
12501 		}
12502 		rack_log_ack(tp, to, th, ((in_rec == 0) && IN_FASTRECOVERY(tp->t_flags)),
12503 			     dup_ack_struck, &dsack_seen, &sacks_seen);
12504 
12505 	}
12506 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
12507 		/*
12508 		 * Old ack, behind (or duplicate to) the last one rcv'd
12509 		 * Note: We mark reordering is occuring if its
12510 		 * less than and we have not closed our window.
12511 		 */
12512 		if (SEQ_LT(th->th_ack, tp->snd_una) && (sbspace(&so->so_rcv) > ctf_fixed_maxseg(tp))) {
12513 			rack->r_ctl.rc_reorder_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
12514 			if (rack->r_ctl.rc_reorder_ts == 0)
12515 				rack->r_ctl.rc_reorder_ts = 1;
12516 		}
12517 		return (0);
12518 	}
12519 	/*
12520 	 * If we reach this point, ACK is not a duplicate, i.e., it ACKs
12521 	 * something we sent.
12522 	 */
12523 	if (tp->t_flags & TF_NEEDSYN) {
12524 		/*
12525 		 * T/TCP: Connection was half-synchronized, and our SYN has
12526 		 * been ACK'd (so connection is now fully synchronized).  Go
12527 		 * to non-starred state, increment snd_una for ACK of SYN,
12528 		 * and check if we can do window scaling.
12529 		 */
12530 		tp->t_flags &= ~TF_NEEDSYN;
12531 		tp->snd_una++;
12532 		/* Do window scaling? */
12533 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
12534 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
12535 			tp->rcv_scale = tp->request_r_scale;
12536 			/* Send window already scaled. */
12537 		}
12538 	}
12539 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
12540 
12541 	acked = BYTES_THIS_ACK(tp, th);
12542 	if (acked) {
12543 		/*
12544 		 * Any time we move the cum-ack forward clear
12545 		 * keep-alive tied probe-not-answered. The
12546 		 * persists clears its own on entry.
12547 		 */
12548 		rack->probe_not_answered = 0;
12549 	}
12550 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
12551 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
12552 	/*
12553 	 * If we just performed our first retransmit, and the ACK arrives
12554 	 * within our recovery window, then it was a mistake to do the
12555 	 * retransmit in the first place.  Recover our original cwnd and
12556 	 * ssthresh, and proceed to transmit where we left off.
12557 	 */
12558 	if ((tp->t_flags & TF_PREVVALID) &&
12559 	    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
12560 		tp->t_flags &= ~TF_PREVVALID;
12561 		if (tp->t_rxtshift == 1 &&
12562 		    (int)(ticks - tp->t_badrxtwin) < 0)
12563 			rack_cong_signal(tp, CC_RTO_ERR, th->th_ack, __LINE__);
12564 	}
12565 	if (acked) {
12566 		/* assure we are not backed off */
12567 		tp->t_rxtshift = 0;
12568 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
12569 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
12570 		rack->rc_tlp_in_progress = 0;
12571 		rack->r_ctl.rc_tlp_cnt_out = 0;
12572 		/*
12573 		 * If it is the RXT timer we want to
12574 		 * stop it, so we can restart a TLP.
12575 		 */
12576 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
12577 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
12578 #ifdef TCP_REQUEST_TRK
12579 		rack_req_check_for_comp(rack, th->th_ack);
12580 #endif
12581 	}
12582 	/*
12583 	 * If we have a timestamp reply, update smoothed round trip time. If
12584 	 * no timestamp is present but transmit timer is running and timed
12585 	 * sequence number was acked, update smoothed round trip time. Since
12586 	 * we now have an rtt measurement, cancel the timer backoff (cf.,
12587 	 * Phil Karn's retransmit alg.). Recompute the initial retransmit
12588 	 * timer.
12589 	 *
12590 	 * Some boxes send broken timestamp replies during the SYN+ACK
12591 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
12592 	 * and blow up the retransmit timer.
12593 	 */
12594 	/*
12595 	 * If all outstanding data is acked, stop retransmit timer and
12596 	 * remember to restart (more output or persist). If there is more
12597 	 * data to be acked, restart retransmit timer, using current
12598 	 * (possibly backed-off) value.
12599 	 */
12600 	if (acked == 0) {
12601 		if (ofia)
12602 			*ofia = ourfinisacked;
12603 		return (0);
12604 	}
12605 	if (IN_RECOVERY(tp->t_flags)) {
12606 		if (SEQ_LT(th->th_ack, tp->snd_recover) &&
12607 		    (SEQ_LT(th->th_ack, tp->snd_max))) {
12608 			tcp_rack_partialack(tp);
12609 		} else {
12610 			rack_post_recovery(tp, th->th_ack);
12611 			post_recovery = 1;
12612 			/*
12613 			 * Grab the segsiz, multiply by 2 and add the snd_cwnd
12614 			 * that is the max the CC should add if we are exiting
12615 			 * recovery and doing a late add.
12616 			 */
12617 			p_cwnd = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
12618 			p_cwnd <<= 1;
12619 			p_cwnd += tp->snd_cwnd;
12620 		}
12621 	} else if ((rack->rto_from_rec == 1) &&
12622 		   SEQ_GEQ(th->th_ack, tp->snd_recover)) {
12623 		/*
12624 		 * We were in recovery, hit a rxt timeout
12625 		 * and never re-entered recovery. The timeout(s)
12626 		 * made up all the lost data. In such a case
12627 		 * we need to clear the rto_from_rec flag.
12628 		 */
12629 		rack->rto_from_rec = 0;
12630 	}
12631 	/*
12632 	 * Let the congestion control algorithm update congestion control
12633 	 * related information. This typically means increasing the
12634 	 * congestion window.
12635 	 */
12636 	rack_ack_received(tp, rack, th->th_ack, nsegs, CC_ACK, post_recovery);
12637 	if (post_recovery &&
12638 	    (tp->snd_cwnd > p_cwnd)) {
12639 		/* Must be non-newreno (cubic) getting too ahead of itself */
12640 		tp->snd_cwnd = p_cwnd;
12641 	}
12642 	SOCKBUF_LOCK(&so->so_snd);
12643 	acked_amount = min(acked, (int)sbavail(&so->so_snd));
12644 	tp->snd_wnd -= acked_amount;
12645 	mfree = sbcut_locked(&so->so_snd, acked_amount);
12646 	if ((sbused(&so->so_snd) == 0) &&
12647 	    (acked > acked_amount) &&
12648 	    (tp->t_state >= TCPS_FIN_WAIT_1) &&
12649 	    (tp->t_flags & TF_SENTFIN)) {
12650 		/*
12651 		 * We must be sure our fin
12652 		 * was sent and acked (we can be
12653 		 * in FIN_WAIT_1 without having
12654 		 * sent the fin).
12655 		 */
12656 		ourfinisacked = 1;
12657 	}
12658 	tp->snd_una = th->th_ack;
12659 	/* wakeups? */
12660 	if (acked_amount && sbavail(&so->so_snd))
12661 		rack_adjust_sendmap_head(rack, &so->so_snd);
12662 	rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
12663 	/* NB: sowwakeup_locked() does an implicit unlock. */
12664 	sowwakeup_locked(so);
12665 	m_freem(mfree);
12666 	if (SEQ_GT(tp->snd_una, tp->snd_recover))
12667 		tp->snd_recover = tp->snd_una;
12668 
12669 	if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
12670 		tp->snd_nxt = tp->snd_max;
12671 	}
12672 	if (under_pacing &&
12673 	    (rack->use_fixed_rate == 0) &&
12674 	    (rack->in_probe_rtt == 0) &&
12675 	    rack->rc_gp_dyn_mul &&
12676 	    rack->rc_always_pace) {
12677 		/* Check if we are dragging bottom */
12678 		rack_check_bottom_drag(tp, rack, so);
12679 	}
12680 	if (tp->snd_una == tp->snd_max) {
12681 		/* Nothing left outstanding */
12682 		tp->t_flags &= ~TF_PREVVALID;
12683 		rack->r_ctl.idle_snd_una = tp->snd_una;
12684 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
12685 		if (rack->r_ctl.rc_went_idle_time == 0)
12686 			rack->r_ctl.rc_went_idle_time = 1;
12687 		rack->r_ctl.retran_during_recovery = 0;
12688 		rack->r_ctl.dsack_byte_cnt = 0;
12689 		rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
12690 		if (sbavail(&tptosocket(tp)->so_snd) == 0)
12691 			tp->t_acktime = 0;
12692 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
12693 		rack->rc_suspicious = 0;
12694 		/* Set need output so persist might get set */
12695 		rack->r_wanted_output = 1;
12696 		sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
12697 		if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
12698 		    (sbavail(&so->so_snd) == 0) &&
12699 		    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
12700 			/*
12701 			 * The socket was gone and the
12702 			 * peer sent data (now or in the past), time to
12703 			 * reset him.
12704 			 */
12705 			*ret_val = 1;
12706 			/* tcp_close will kill the inp pre-log the Reset */
12707 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
12708 			tp = tcp_close(tp);
12709 			ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, tlen);
12710 			return (1);
12711 		}
12712 	}
12713 	if (ofia)
12714 		*ofia = ourfinisacked;
12715 	return (0);
12716 }
12717 
12718 
12719 static void
rack_log_collapse(struct tcp_rack * rack,uint32_t cnt,uint32_t split,uint32_t out,int line,int dir,uint32_t flags,struct rack_sendmap * rsm)12720 rack_log_collapse(struct tcp_rack *rack, uint32_t cnt, uint32_t split, uint32_t out, int line,
12721 		  int dir, uint32_t flags, struct rack_sendmap *rsm)
12722 {
12723 	if (tcp_bblogging_on(rack->rc_tp)) {
12724 		union tcp_log_stackspecific log;
12725 		struct timeval tv;
12726 
12727 		memset(&log, 0, sizeof(log));
12728 		log.u_bbr.flex1 = cnt;
12729 		log.u_bbr.flex2 = split;
12730 		log.u_bbr.flex3 = out;
12731 		log.u_bbr.flex4 = line;
12732 		log.u_bbr.flex5 = rack->r_must_retran;
12733 		log.u_bbr.flex6 = flags;
12734 		log.u_bbr.flex7 = rack->rc_has_collapsed;
12735 		log.u_bbr.flex8 = dir;	/*
12736 					 * 1 is collapsed, 0 is uncollapsed,
12737 					 * 2 is log of a rsm being marked, 3 is a split.
12738 					 */
12739 		if (rsm == NULL)
12740 			log.u_bbr.rttProp = 0;
12741 		else
12742 			log.u_bbr.rttProp = (uint64_t)rsm;
12743 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
12744 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
12745 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
12746 		    &rack->rc_inp->inp_socket->so_rcv,
12747 		    &rack->rc_inp->inp_socket->so_snd,
12748 		    TCP_RACK_LOG_COLLAPSE, 0,
12749 		    0, &log, false, &tv);
12750 	}
12751 }
12752 
12753 static void
rack_collapsed_window(struct tcp_rack * rack,uint32_t out,tcp_seq th_ack,int line)12754 rack_collapsed_window(struct tcp_rack *rack, uint32_t out, tcp_seq th_ack, int line)
12755 {
12756 	/*
12757 	 * Here all we do is mark the collapsed point and set the flag.
12758 	 * This may happen again and again, but there is no
12759 	 * sense splitting our map until we know where the
12760 	 * peer finally lands in the collapse.
12761 	 */
12762 	tcp_trace_point(rack->rc_tp, TCP_TP_COLLAPSED_WND);
12763 	if ((rack->rc_has_collapsed == 0) ||
12764 	    (rack->r_ctl.last_collapse_point != (th_ack + rack->rc_tp->snd_wnd)))
12765 		counter_u64_add(rack_collapsed_win_seen, 1);
12766 	rack->r_ctl.last_collapse_point = th_ack + rack->rc_tp->snd_wnd;
12767 	rack->r_ctl.high_collapse_point = rack->rc_tp->snd_max;
12768 	rack->rc_has_collapsed = 1;
12769 	rack->r_collapse_point_valid = 1;
12770 	rack_log_collapse(rack, 0, th_ack, rack->r_ctl.last_collapse_point, line, 1, 0, NULL);
12771 }
12772 
12773 static void
rack_un_collapse_window(struct tcp_rack * rack,int line)12774 rack_un_collapse_window(struct tcp_rack *rack, int line)
12775 {
12776 	struct rack_sendmap *nrsm, *rsm;
12777 	int cnt = 0, split = 0;
12778 	int insret __diagused;
12779 
12780 
12781 	tcp_trace_point(rack->rc_tp, TCP_TP_COLLAPSED_WND);
12782 	rack->rc_has_collapsed = 0;
12783 	rsm = tqhash_find(rack->r_ctl.tqh, rack->r_ctl.last_collapse_point);
12784 	if (rsm == NULL) {
12785 		/* Nothing to do maybe the peer ack'ed it all */
12786 		rack_log_collapse(rack, 0, 0, ctf_outstanding(rack->rc_tp), line, 0, 0, NULL);
12787 		return;
12788 	}
12789 	/* Now do we need to split this one? */
12790 	if (SEQ_GT(rack->r_ctl.last_collapse_point, rsm->r_start)) {
12791 		rack_log_collapse(rack, rsm->r_start, rsm->r_end,
12792 				  rack->r_ctl.last_collapse_point, line, 3, rsm->r_flags, rsm);
12793 		nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
12794 		if (nrsm == NULL) {
12795 			/* We can't get a rsm, mark all? */
12796 			nrsm = rsm;
12797 			goto no_split;
12798 		}
12799 		/* Clone it */
12800 		split = 1;
12801 		rack_clone_rsm(rack, nrsm, rsm, rack->r_ctl.last_collapse_point);
12802 #ifndef INVARIANTS
12803 		(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
12804 #else
12805 		if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
12806 			panic("Insert in tailq_hash of %p fails ret:%d rack:%p rsm:%p",
12807 			      nrsm, insret, rack, rsm);
12808 		}
12809 #endif
12810 		rack_log_map_chg(rack->rc_tp, rack, NULL, rsm, nrsm, MAP_SPLIT,
12811 				 rack->r_ctl.last_collapse_point, __LINE__);
12812 		if (rsm->r_in_tmap) {
12813 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
12814 			nrsm->r_in_tmap = 1;
12815 		}
12816 		/*
12817 		 * Set in the new RSM as the
12818 		 * collapsed starting point
12819 		 */
12820 		rsm = nrsm;
12821 	}
12822 
12823 no_split:
12824 	TQHASH_FOREACH_FROM(nrsm, rack->r_ctl.tqh, rsm)  {
12825 		cnt++;
12826 		nrsm->r_flags |= RACK_RWND_COLLAPSED;
12827 		rack_log_collapse(rack, nrsm->r_start, nrsm->r_end, 0, line, 4, nrsm->r_flags, nrsm);
12828 		cnt++;
12829 	}
12830 	if (cnt) {
12831 		counter_u64_add(rack_collapsed_win, 1);
12832 	}
12833 	rack_log_collapse(rack, cnt, split, ctf_outstanding(rack->rc_tp), line, 0, 0, NULL);
12834 }
12835 
12836 static void
rack_handle_delayed_ack(struct tcpcb * tp,struct tcp_rack * rack,int32_t tlen,int32_t tfo_syn)12837 rack_handle_delayed_ack(struct tcpcb *tp, struct tcp_rack *rack,
12838 			int32_t tlen, int32_t tfo_syn)
12839 {
12840 	if (DELAY_ACK(tp, tlen) || tfo_syn) {
12841 		rack_timer_cancel(tp, rack,
12842 				  rack->r_ctl.rc_rcvtime, __LINE__);
12843 		tp->t_flags |= TF_DELACK;
12844 	} else {
12845 		rack->r_wanted_output = 1;
12846 		tp->t_flags |= TF_ACKNOW;
12847 	}
12848 }
12849 
12850 static void
rack_validate_fo_sendwin_up(struct tcpcb * tp,struct tcp_rack * rack)12851 rack_validate_fo_sendwin_up(struct tcpcb *tp, struct tcp_rack *rack)
12852 {
12853 	/*
12854 	 * If fast output is in progress, lets validate that
12855 	 * the new window did not shrink on us and make it
12856 	 * so fast output should end.
12857 	 */
12858 	if (rack->r_fast_output) {
12859 		uint32_t out;
12860 
12861 		/*
12862 		 * Calculate what we will send if left as is
12863 		 * and compare that to our send window.
12864 		 */
12865 		out = ctf_outstanding(tp);
12866 		if ((out + rack->r_ctl.fsb.left_to_send) > tp->snd_wnd) {
12867 			/* ok we have an issue */
12868 			if (out >= tp->snd_wnd) {
12869 				/* Turn off fast output the window is met or collapsed */
12870 				rack->r_fast_output = 0;
12871 			} else {
12872 				/* we have some room left */
12873 				rack->r_ctl.fsb.left_to_send = tp->snd_wnd - out;
12874 				if (rack->r_ctl.fsb.left_to_send < ctf_fixed_maxseg(tp)) {
12875 					/* If not at least 1 full segment never mind */
12876 					rack->r_fast_output = 0;
12877 				}
12878 			}
12879 		}
12880 	}
12881 }
12882 
12883 /*
12884  * Return value of 1, the TCB is unlocked and most
12885  * likely gone, return value of 0, the TCP is still
12886  * locked.
12887  */
12888 static int
rack_process_data(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt)12889 rack_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so,
12890     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
12891     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
12892 {
12893 	/*
12894 	 * Update window information. Don't look at window if no ACK: TAC's
12895 	 * send garbage on first SYN.
12896 	 */
12897 	int32_t nsegs;
12898 	int32_t tfo_syn;
12899 	struct tcp_rack *rack;
12900 
12901 	INP_WLOCK_ASSERT(tptoinpcb(tp));
12902 
12903 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12904 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
12905 	if ((thflags & TH_ACK) &&
12906 	    (SEQ_LT(tp->snd_wl1, th->th_seq) ||
12907 	    (tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) ||
12908 	    (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) {
12909 		/* keep track of pure window updates */
12910 		if (tlen == 0 &&
12911 		    tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd)
12912 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
12913 		tp->snd_wnd = tiwin;
12914 		rack_validate_fo_sendwin_up(tp, rack);
12915 		tp->snd_wl1 = th->th_seq;
12916 		tp->snd_wl2 = th->th_ack;
12917 		if (tp->snd_wnd > tp->max_sndwnd)
12918 			tp->max_sndwnd = tp->snd_wnd;
12919 		rack->r_wanted_output = 1;
12920 	} else if (thflags & TH_ACK) {
12921 		if ((tp->snd_wl2 == th->th_ack) && (tiwin < tp->snd_wnd)) {
12922 			tp->snd_wnd = tiwin;
12923 			rack_validate_fo_sendwin_up(tp, rack);
12924 			tp->snd_wl1 = th->th_seq;
12925 			tp->snd_wl2 = th->th_ack;
12926 		}
12927 	}
12928 	if (tp->snd_wnd < ctf_outstanding(tp))
12929 		/* The peer collapsed the window */
12930 		rack_collapsed_window(rack, ctf_outstanding(tp), th->th_ack, __LINE__);
12931 	else if (rack->rc_has_collapsed)
12932 		rack_un_collapse_window(rack, __LINE__);
12933 	if ((rack->r_collapse_point_valid) &&
12934 	    (SEQ_GT(th->th_ack, rack->r_ctl.high_collapse_point)))
12935 		rack->r_collapse_point_valid = 0;
12936 	/* Was persist timer active and now we have window space? */
12937 	if ((rack->rc_in_persist != 0) &&
12938 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
12939 				rack->r_ctl.rc_pace_min_segs))) {
12940 		rack_exit_persist(tp, rack, rack->r_ctl.rc_rcvtime);
12941 		tp->snd_nxt = tp->snd_max;
12942 		/* Make sure we output to start the timer */
12943 		rack->r_wanted_output = 1;
12944 	}
12945 	/* Do we enter persists? */
12946 	if ((rack->rc_in_persist == 0) &&
12947 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
12948 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
12949 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
12950 	    sbavail(&tptosocket(tp)->so_snd) &&
12951 	    (sbavail(&tptosocket(tp)->so_snd) > tp->snd_wnd)) {
12952 		/*
12953 		 * Here the rwnd is less than
12954 		 * the pacing size, we are established,
12955 		 * nothing is outstanding, and there is
12956 		 * data to send. Enter persists.
12957 		 */
12958 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime, tp->snd_una);
12959 	}
12960 	if (tp->t_flags2 & TF2_DROP_AF_DATA) {
12961 		m_freem(m);
12962 		return (0);
12963 	}
12964 	/*
12965 	 * don't process the URG bit, ignore them drag
12966 	 * along the up.
12967 	 */
12968 	tp->rcv_up = tp->rcv_nxt;
12969 
12970 	/*
12971 	 * Process the segment text, merging it into the TCP sequencing
12972 	 * queue, and arranging for acknowledgment of receipt if necessary.
12973 	 * This process logically involves adjusting tp->rcv_wnd as data is
12974 	 * presented to the user (this happens in tcp_usrreq.c, case
12975 	 * PRU_RCVD).  If a FIN has already been received on this connection
12976 	 * then we just ignore the text.
12977 	 */
12978 	tfo_syn = ((tp->t_state == TCPS_SYN_RECEIVED) &&
12979 	    (tp->t_flags & TF_FASTOPEN));
12980 	if ((tlen || (thflags & TH_FIN) || (tfo_syn && tlen > 0)) &&
12981 	    TCPS_HAVERCVDFIN(tp->t_state) == 0) {
12982 		tcp_seq save_start = th->th_seq;
12983 		tcp_seq save_rnxt  = tp->rcv_nxt;
12984 		int     save_tlen  = tlen;
12985 
12986 		m_adj(m, drop_hdrlen);	/* delayed header drop */
12987 		/*
12988 		 * Insert segment which includes th into TCP reassembly
12989 		 * queue with control block tp.  Set thflags to whether
12990 		 * reassembly now includes a segment with FIN.  This handles
12991 		 * the common case inline (segment is the next to be
12992 		 * received on an established connection, and the queue is
12993 		 * empty), avoiding linkage into and removal from the queue
12994 		 * and repetition of various conversions. Set DELACK for
12995 		 * segments received in order, but ack immediately when
12996 		 * segments are out of order (so fast retransmit can work).
12997 		 */
12998 		if (th->th_seq == tp->rcv_nxt &&
12999 		    SEGQ_EMPTY(tp) &&
13000 		    (TCPS_HAVEESTABLISHED(tp->t_state) ||
13001 		    tfo_syn)) {
13002 #ifdef NETFLIX_SB_LIMITS
13003 			u_int mcnt, appended;
13004 
13005 			if (so->so_rcv.sb_shlim) {
13006 				mcnt = m_memcnt(m);
13007 				appended = 0;
13008 				if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
13009 				    CFO_NOSLEEP, NULL) == false) {
13010 					counter_u64_add(tcp_sb_shlim_fails, 1);
13011 					m_freem(m);
13012 					return (0);
13013 				}
13014 			}
13015 #endif
13016 			rack_handle_delayed_ack(tp, rack, tlen, tfo_syn);
13017 			tp->rcv_nxt += tlen;
13018 			if (tlen &&
13019 			    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
13020 			    (tp->t_fbyte_in == 0)) {
13021 				tp->t_fbyte_in = ticks;
13022 				if (tp->t_fbyte_in == 0)
13023 					tp->t_fbyte_in = 1;
13024 				if (tp->t_fbyte_out && tp->t_fbyte_in)
13025 					tp->t_flags2 |= TF2_FBYTES_COMPLETE;
13026 			}
13027 			thflags = tcp_get_flags(th) & TH_FIN;
13028 			KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
13029 			KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
13030 			SOCKBUF_LOCK(&so->so_rcv);
13031 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13032 				m_freem(m);
13033 			} else {
13034 				int32_t newsize;
13035 
13036 				if (tlen > 0) {
13037 					newsize = tcp_autorcvbuf(m, th, so, tp, tlen);
13038 					if (newsize)
13039 						if (!sbreserve_locked(so, SO_RCV, newsize, NULL))
13040 							so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
13041 				}
13042 #ifdef NETFLIX_SB_LIMITS
13043 				appended =
13044 #endif
13045 					sbappendstream_locked(&so->so_rcv, m, 0);
13046 			}
13047 			rack_log_wakeup(tp,rack, &so->so_rcv, tlen, 1);
13048 			/* NB: sorwakeup_locked() does an implicit unlock. */
13049 			sorwakeup_locked(so);
13050 #ifdef NETFLIX_SB_LIMITS
13051 			if (so->so_rcv.sb_shlim && appended != mcnt)
13052 				counter_fo_release(so->so_rcv.sb_shlim,
13053 				    mcnt - appended);
13054 #endif
13055 		} else {
13056 			/*
13057 			 * XXX: Due to the header drop above "th" is
13058 			 * theoretically invalid by now.  Fortunately
13059 			 * m_adj() doesn't actually frees any mbufs when
13060 			 * trimming from the head.
13061 			 */
13062 			tcp_seq temp = save_start;
13063 
13064 			thflags = tcp_reass(tp, th, &temp, &tlen, m);
13065 			tp->t_flags |= TF_ACKNOW;
13066 			if (tp->t_flags & TF_WAKESOR) {
13067 				tp->t_flags &= ~TF_WAKESOR;
13068 				/* NB: sorwakeup_locked() does an implicit unlock. */
13069 				sorwakeup_locked(so);
13070 			}
13071 		}
13072 		if ((tp->t_flags & TF_SACK_PERMIT) &&
13073 		    (save_tlen > 0) &&
13074 		    TCPS_HAVEESTABLISHED(tp->t_state)) {
13075 			if ((tlen == 0) && (SEQ_LT(save_start, save_rnxt))) {
13076 				/*
13077 				 * DSACK actually handled in the fastpath
13078 				 * above.
13079 				 */
13080 				tcp_update_sack_list(tp, save_start,
13081 				    save_start + save_tlen);
13082 			} else if ((tlen > 0) && SEQ_GT(tp->rcv_nxt, save_rnxt)) {
13083 				if ((tp->rcv_numsacks >= 1) &&
13084 				    (tp->sackblks[0].end == save_start)) {
13085 					/*
13086 					 * Partial overlap, recorded at todrop
13087 					 * above.
13088 					 */
13089 					tcp_update_sack_list(tp,
13090 					    tp->sackblks[0].start,
13091 					    tp->sackblks[0].end);
13092 				} else {
13093 					tcp_update_dsack_list(tp, save_start,
13094 					    save_start + save_tlen);
13095 				}
13096 			} else if (tlen >= save_tlen) {
13097 				/* Update of sackblks. */
13098 				tcp_update_dsack_list(tp, save_start,
13099 				    save_start + save_tlen);
13100 			} else if (tlen > 0) {
13101 				tcp_update_dsack_list(tp, save_start,
13102 				    save_start + tlen);
13103 			}
13104 		}
13105 	} else {
13106 		m_freem(m);
13107 		thflags &= ~TH_FIN;
13108 	}
13109 
13110 	/*
13111 	 * If FIN is received ACK the FIN and let the user know that the
13112 	 * connection is closing.
13113 	 */
13114 	if (thflags & TH_FIN) {
13115 		if (TCPS_HAVERCVDFIN(tp->t_state) == 0) {
13116 			/* The socket upcall is handled by socantrcvmore. */
13117 			socantrcvmore(so);
13118 			/*
13119 			 * If connection is half-synchronized (ie NEEDSYN
13120 			 * flag on) then delay ACK, so it may be piggybacked
13121 			 * when SYN is sent. Otherwise, since we received a
13122 			 * FIN then no more input can be expected, send ACK
13123 			 * now.
13124 			 */
13125 			if (tp->t_flags & TF_NEEDSYN) {
13126 				rack_timer_cancel(tp, rack,
13127 				    rack->r_ctl.rc_rcvtime, __LINE__);
13128 				tp->t_flags |= TF_DELACK;
13129 			} else {
13130 				tp->t_flags |= TF_ACKNOW;
13131 			}
13132 			tp->rcv_nxt++;
13133 		}
13134 		switch (tp->t_state) {
13135 			/*
13136 			 * In SYN_RECEIVED and ESTABLISHED STATES enter the
13137 			 * CLOSE_WAIT state.
13138 			 */
13139 		case TCPS_SYN_RECEIVED:
13140 			tp->t_starttime = ticks;
13141 			/* FALLTHROUGH */
13142 		case TCPS_ESTABLISHED:
13143 			rack_timer_cancel(tp, rack,
13144 			    rack->r_ctl.rc_rcvtime, __LINE__);
13145 			tcp_state_change(tp, TCPS_CLOSE_WAIT);
13146 			break;
13147 
13148 			/*
13149 			 * If still in FIN_WAIT_1 STATE FIN has not been
13150 			 * acked so enter the CLOSING state.
13151 			 */
13152 		case TCPS_FIN_WAIT_1:
13153 			rack_timer_cancel(tp, rack,
13154 			    rack->r_ctl.rc_rcvtime, __LINE__);
13155 			tcp_state_change(tp, TCPS_CLOSING);
13156 			break;
13157 
13158 			/*
13159 			 * In FIN_WAIT_2 state enter the TIME_WAIT state,
13160 			 * starting the time-wait timer, turning off the
13161 			 * other standard timers.
13162 			 */
13163 		case TCPS_FIN_WAIT_2:
13164 			rack_timer_cancel(tp, rack,
13165 			    rack->r_ctl.rc_rcvtime, __LINE__);
13166 			tcp_twstart(tp);
13167 			return (1);
13168 		}
13169 	}
13170 	/*
13171 	 * Return any desired output.
13172 	 */
13173 	if ((tp->t_flags & TF_ACKNOW) ||
13174 	    (sbavail(&so->so_snd) > (tp->snd_max - tp->snd_una))) {
13175 		rack->r_wanted_output = 1;
13176 	}
13177 	return (0);
13178 }
13179 
13180 /*
13181  * Here nothing is really faster, its just that we
13182  * have broken out the fast-data path also just like
13183  * the fast-ack.
13184  */
13185 static int
rack_do_fastnewdata(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t nxt_pkt,uint8_t iptos)13186 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th, struct socket *so,
13187     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13188     uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos)
13189 {
13190 	int32_t nsegs;
13191 	int32_t newsize = 0;	/* automatic sockbuf scaling */
13192 	struct tcp_rack *rack;
13193 #ifdef NETFLIX_SB_LIMITS
13194 	u_int mcnt, appended;
13195 #endif
13196 
13197 	/*
13198 	 * If last ACK falls within this segment's sequence numbers, record
13199 	 * the timestamp. NOTE that the test is modified according to the
13200 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
13201 	 */
13202 	if (__predict_false(th->th_seq != tp->rcv_nxt)) {
13203 		return (0);
13204 	}
13205 	if (tiwin && tiwin != tp->snd_wnd) {
13206 		return (0);
13207 	}
13208 	if (__predict_false((tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN)))) {
13209 		return (0);
13210 	}
13211 	if (__predict_false((to->to_flags & TOF_TS) &&
13212 	    (TSTMP_LT(to->to_tsval, tp->ts_recent)))) {
13213 		return (0);
13214 	}
13215 	if (__predict_false((th->th_ack != tp->snd_una))) {
13216 		return (0);
13217 	}
13218 	if (__predict_false(tlen > sbspace(&so->so_rcv))) {
13219 		return (0);
13220 	}
13221 	if ((to->to_flags & TOF_TS) != 0 &&
13222 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
13223 		tp->ts_recent_age = tcp_ts_getticks();
13224 		tp->ts_recent = to->to_tsval;
13225 	}
13226 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13227 	/*
13228 	 * This is a pure, in-sequence data packet with nothing on the
13229 	 * reassembly queue and we have enough buffer space to take it.
13230 	 */
13231 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
13232 
13233 #ifdef NETFLIX_SB_LIMITS
13234 	if (so->so_rcv.sb_shlim) {
13235 		mcnt = m_memcnt(m);
13236 		appended = 0;
13237 		if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
13238 		    CFO_NOSLEEP, NULL) == false) {
13239 			counter_u64_add(tcp_sb_shlim_fails, 1);
13240 			m_freem(m);
13241 			return (1);
13242 		}
13243 	}
13244 #endif
13245 	/* Clean receiver SACK report if present */
13246 	if (tp->rcv_numsacks)
13247 		tcp_clean_sackreport(tp);
13248 	KMOD_TCPSTAT_INC(tcps_preddat);
13249 	tp->rcv_nxt += tlen;
13250 	if (tlen &&
13251 	    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
13252 	    (tp->t_fbyte_in == 0)) {
13253 		tp->t_fbyte_in = ticks;
13254 		if (tp->t_fbyte_in == 0)
13255 			tp->t_fbyte_in = 1;
13256 		if (tp->t_fbyte_out && tp->t_fbyte_in)
13257 			tp->t_flags2 |= TF2_FBYTES_COMPLETE;
13258 	}
13259 	/*
13260 	 * Pull snd_wl1 up to prevent seq wrap relative to th_seq.
13261 	 */
13262 	tp->snd_wl1 = th->th_seq;
13263 	/*
13264 	 * Pull rcv_up up to prevent seq wrap relative to rcv_nxt.
13265 	 */
13266 	tp->rcv_up = tp->rcv_nxt;
13267 	KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
13268 	KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
13269 	newsize = tcp_autorcvbuf(m, th, so, tp, tlen);
13270 
13271 	/* Add data to socket buffer. */
13272 	SOCKBUF_LOCK(&so->so_rcv);
13273 	if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13274 		m_freem(m);
13275 	} else {
13276 		/*
13277 		 * Set new socket buffer size. Give up when limit is
13278 		 * reached.
13279 		 */
13280 		if (newsize)
13281 			if (!sbreserve_locked(so, SO_RCV, newsize, NULL))
13282 				so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
13283 		m_adj(m, drop_hdrlen);	/* delayed header drop */
13284 #ifdef NETFLIX_SB_LIMITS
13285 		appended =
13286 #endif
13287 			sbappendstream_locked(&so->so_rcv, m, 0);
13288 		ctf_calc_rwin(so, tp);
13289 	}
13290 	rack_log_wakeup(tp,rack, &so->so_rcv, tlen, 1);
13291 	/* NB: sorwakeup_locked() does an implicit unlock. */
13292 	sorwakeup_locked(so);
13293 #ifdef NETFLIX_SB_LIMITS
13294 	if (so->so_rcv.sb_shlim && mcnt != appended)
13295 		counter_fo_release(so->so_rcv.sb_shlim, mcnt - appended);
13296 #endif
13297 	rack_handle_delayed_ack(tp, rack, tlen, 0);
13298 	if (tp->snd_una == tp->snd_max)
13299 		sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
13300 	return (1);
13301 }
13302 
13303 /*
13304  * This subfunction is used to try to highly optimize the
13305  * fast path. We again allow window updates that are
13306  * in sequence to remain in the fast-path. We also add
13307  * in the __predict's to attempt to help the compiler.
13308  * Note that if we return a 0, then we can *not* process
13309  * it and the caller should push the packet into the
13310  * slow-path.
13311  */
13312 static int
rack_fastack(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t nxt_pkt,uint32_t cts)13313 rack_fastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
13314     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13315     uint32_t tiwin, int32_t nxt_pkt, uint32_t cts)
13316 {
13317 	int32_t acked;
13318 	int32_t nsegs;
13319 	int32_t under_pacing = 0;
13320 	struct tcp_rack *rack;
13321 
13322 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
13323 		/* Old ack, behind (or duplicate to) the last one rcv'd */
13324 		return (0);
13325 	}
13326 	if (__predict_false(SEQ_GT(th->th_ack, tp->snd_max))) {
13327 		/* Above what we have sent? */
13328 		return (0);
13329 	}
13330 	if (__predict_false(tiwin == 0)) {
13331 		/* zero window */
13332 		return (0);
13333 	}
13334 	if (__predict_false(tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN))) {
13335 		/* We need a SYN or a FIN, unlikely.. */
13336 		return (0);
13337 	}
13338 	if ((to->to_flags & TOF_TS) && __predict_false(TSTMP_LT(to->to_tsval, tp->ts_recent))) {
13339 		/* Timestamp is behind .. old ack with seq wrap? */
13340 		return (0);
13341 	}
13342 	if (__predict_false(IN_RECOVERY(tp->t_flags))) {
13343 		/* Still recovering */
13344 		return (0);
13345 	}
13346 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13347 	if (rack->r_ctl.rc_sacked) {
13348 		/* We have sack holes on our scoreboard */
13349 		return (0);
13350 	}
13351 	/* Ok if we reach here, we can process a fast-ack */
13352 	if (rack->gp_ready &&
13353 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
13354 		under_pacing = 1;
13355 	}
13356 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
13357 	rack_log_ack(tp, to, th, 0, 0, NULL, NULL);
13358 	/* Did the window get updated? */
13359 	if (tiwin != tp->snd_wnd) {
13360 		tp->snd_wnd = tiwin;
13361 		rack_validate_fo_sendwin_up(tp, rack);
13362 		tp->snd_wl1 = th->th_seq;
13363 		if (tp->snd_wnd > tp->max_sndwnd)
13364 			tp->max_sndwnd = tp->snd_wnd;
13365 	}
13366 	/* Do we exit persists? */
13367 	if ((rack->rc_in_persist != 0) &&
13368 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
13369 			       rack->r_ctl.rc_pace_min_segs))) {
13370 		rack_exit_persist(tp, rack, cts);
13371 	}
13372 	/* Do we enter persists? */
13373 	if ((rack->rc_in_persist == 0) &&
13374 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
13375 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
13376 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
13377 	    sbavail(&tptosocket(tp)->so_snd) &&
13378 	    (sbavail(&tptosocket(tp)->so_snd) > tp->snd_wnd)) {
13379 		/*
13380 		 * Here the rwnd is less than
13381 		 * the pacing size, we are established,
13382 		 * nothing is outstanding, and there is
13383 		 * data to send. Enter persists.
13384 		 */
13385 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime, th->th_ack);
13386 	}
13387 	/*
13388 	 * If last ACK falls within this segment's sequence numbers, record
13389 	 * the timestamp. NOTE that the test is modified according to the
13390 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
13391 	 */
13392 	if ((to->to_flags & TOF_TS) != 0 &&
13393 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
13394 		tp->ts_recent_age = tcp_ts_getticks();
13395 		tp->ts_recent = to->to_tsval;
13396 	}
13397 	/*
13398 	 * This is a pure ack for outstanding data.
13399 	 */
13400 	KMOD_TCPSTAT_INC(tcps_predack);
13401 
13402 	/*
13403 	 * "bad retransmit" recovery.
13404 	 */
13405 	if ((tp->t_flags & TF_PREVVALID) &&
13406 	    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
13407 		tp->t_flags &= ~TF_PREVVALID;
13408 		if (tp->t_rxtshift == 1 &&
13409 		    (int)(ticks - tp->t_badrxtwin) < 0)
13410 			rack_cong_signal(tp, CC_RTO_ERR, th->th_ack, __LINE__);
13411 	}
13412 	/*
13413 	 * Recalculate the transmit timer / rtt.
13414 	 *
13415 	 * Some boxes send broken timestamp replies during the SYN+ACK
13416 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
13417 	 * and blow up the retransmit timer.
13418 	 */
13419 	acked = BYTES_THIS_ACK(tp, th);
13420 
13421 #ifdef TCP_HHOOK
13422 	/* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */
13423 	hhook_run_tcp_est_in(tp, th, to);
13424 #endif
13425 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
13426 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
13427 	if (acked) {
13428 		struct mbuf *mfree;
13429 
13430 		rack_ack_received(tp, rack, th->th_ack, nsegs, CC_ACK, 0);
13431 		SOCKBUF_LOCK(&so->so_snd);
13432 		mfree = sbcut_locked(&so->so_snd, acked);
13433 		tp->snd_una = th->th_ack;
13434 		/* Note we want to hold the sb lock through the sendmap adjust */
13435 		rack_adjust_sendmap_head(rack, &so->so_snd);
13436 		/* Wake up the socket if we have room to write more */
13437 		rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
13438 		sowwakeup_locked(so);
13439 		m_freem(mfree);
13440 		tp->t_rxtshift = 0;
13441 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
13442 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
13443 		rack->rc_tlp_in_progress = 0;
13444 		rack->r_ctl.rc_tlp_cnt_out = 0;
13445 		/*
13446 		 * If it is the RXT timer we want to
13447 		 * stop it, so we can restart a TLP.
13448 		 */
13449 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
13450 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13451 
13452 #ifdef TCP_REQUEST_TRK
13453 		rack_req_check_for_comp(rack, th->th_ack);
13454 #endif
13455 	}
13456 	/*
13457 	 * Let the congestion control algorithm update congestion control
13458 	 * related information. This typically means increasing the
13459 	 * congestion window.
13460 	 */
13461 	if (tp->snd_wnd < ctf_outstanding(tp)) {
13462 		/* The peer collapsed the window */
13463 		rack_collapsed_window(rack, ctf_outstanding(tp), th->th_ack, __LINE__);
13464 	} else if (rack->rc_has_collapsed)
13465 		rack_un_collapse_window(rack, __LINE__);
13466 	if ((rack->r_collapse_point_valid) &&
13467 	    (SEQ_GT(tp->snd_una, rack->r_ctl.high_collapse_point)))
13468 		rack->r_collapse_point_valid = 0;
13469 	/*
13470 	 * Pull snd_wl2 up to prevent seq wrap relative to th_ack.
13471 	 */
13472 	tp->snd_wl2 = th->th_ack;
13473 	tp->t_dupacks = 0;
13474 	m_freem(m);
13475 	/* ND6_HINT(tp);	 *//* Some progress has been made. */
13476 
13477 	/*
13478 	 * If all outstanding data are acked, stop retransmit timer,
13479 	 * otherwise restart timer using current (possibly backed-off)
13480 	 * value. If process is waiting for space, wakeup/selwakeup/signal.
13481 	 * If data are ready to send, let tcp_output decide between more
13482 	 * output or persist.
13483 	 */
13484 	if (under_pacing &&
13485 	    (rack->use_fixed_rate == 0) &&
13486 	    (rack->in_probe_rtt == 0) &&
13487 	    rack->rc_gp_dyn_mul &&
13488 	    rack->rc_always_pace) {
13489 		/* Check if we are dragging bottom */
13490 		rack_check_bottom_drag(tp, rack, so);
13491 	}
13492 	if (tp->snd_una == tp->snd_max) {
13493 		tp->t_flags &= ~TF_PREVVALID;
13494 		rack->r_ctl.retran_during_recovery = 0;
13495 		rack->rc_suspicious = 0;
13496 		rack->r_ctl.dsack_byte_cnt = 0;
13497 		rack->r_ctl.idle_snd_una = tp->snd_una;
13498 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
13499 		if (rack->r_ctl.rc_went_idle_time == 0)
13500 			rack->r_ctl.rc_went_idle_time = 1;
13501 		rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
13502 		if (sbavail(&tptosocket(tp)->so_snd) == 0)
13503 			tp->t_acktime = 0;
13504 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13505 	}
13506 	if (acked && rack->r_fast_output)
13507 		rack_gain_for_fastoutput(rack, tp, so, (uint32_t)acked);
13508 	if (sbavail(&so->so_snd)) {
13509 		rack->r_wanted_output = 1;
13510 	}
13511 	return (1);
13512 }
13513 
13514 /*
13515  * Return value of 1, the TCB is unlocked and most
13516  * likely gone, return value of 0, the TCP is still
13517  * locked.
13518  */
13519 static int
rack_do_syn_sent(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)13520 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th, struct socket *so,
13521     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13522     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13523 {
13524 	int32_t ret_val = 0;
13525 	int32_t orig_tlen = tlen;
13526 	int32_t todrop;
13527 	int32_t ourfinisacked = 0;
13528 	struct tcp_rack *rack;
13529 
13530 	INP_WLOCK_ASSERT(tptoinpcb(tp));
13531 
13532 	ctf_calc_rwin(so, tp);
13533 	/*
13534 	 * If the state is SYN_SENT: if seg contains an ACK, but not for our
13535 	 * SYN, drop the input. if seg contains a RST, then drop the
13536 	 * connection. if seg does not contain SYN, then drop it. Otherwise
13537 	 * this is an acceptable SYN segment initialize tp->rcv_nxt and
13538 	 * tp->irs if seg contains ack then advance tp->snd_una if seg
13539 	 * contains an ECE and ECN support is enabled, the stream is ECN
13540 	 * capable. if SYN has been acked change to ESTABLISHED else
13541 	 * SYN_RCVD state arrange for segment to be acked (eventually)
13542 	 * continue processing rest of data/controls.
13543 	 */
13544 	if ((thflags & TH_ACK) &&
13545 	    (SEQ_LEQ(th->th_ack, tp->iss) ||
13546 	    SEQ_GT(th->th_ack, tp->snd_max))) {
13547 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
13548 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
13549 		return (1);
13550 	}
13551 	if ((thflags & (TH_ACK | TH_RST)) == (TH_ACK | TH_RST)) {
13552 		TCP_PROBE5(connect__refused, NULL, tp,
13553 		    mtod(m, const char *), tp, th);
13554 		tp = tcp_drop(tp, ECONNREFUSED);
13555 		ctf_do_drop(m, tp);
13556 		return (1);
13557 	}
13558 	if (thflags & TH_RST) {
13559 		ctf_do_drop(m, tp);
13560 		return (1);
13561 	}
13562 	if (!(thflags & TH_SYN)) {
13563 		ctf_do_drop(m, tp);
13564 		return (1);
13565 	}
13566 	tp->irs = th->th_seq;
13567 	tcp_rcvseqinit(tp);
13568 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13569 	if (thflags & TH_ACK) {
13570 		int tfo_partial = 0;
13571 
13572 		KMOD_TCPSTAT_INC(tcps_connects);
13573 		soisconnected(so);
13574 #ifdef MAC
13575 		mac_socketpeer_set_from_mbuf(m, so);
13576 #endif
13577 		/* Do window scaling on this connection? */
13578 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
13579 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
13580 			tp->rcv_scale = tp->request_r_scale;
13581 		}
13582 		tp->rcv_adv += min(tp->rcv_wnd,
13583 		    TCP_MAXWIN << tp->rcv_scale);
13584 		/*
13585 		 * If not all the data that was sent in the TFO SYN
13586 		 * has been acked, resend the remainder right away.
13587 		 */
13588 		if ((tp->t_flags & TF_FASTOPEN) &&
13589 		    (tp->snd_una != tp->snd_max)) {
13590 			/* Was it a partial ack? */
13591 			if (SEQ_LT(th->th_ack, tp->snd_max))
13592 				tfo_partial = 1;
13593 		}
13594 		/*
13595 		 * If there's data, delay ACK; if there's also a FIN ACKNOW
13596 		 * will be turned on later.
13597 		 */
13598 		if (DELAY_ACK(tp, tlen) && tlen != 0 && !tfo_partial) {
13599 			rack_timer_cancel(tp, rack,
13600 					  rack->r_ctl.rc_rcvtime, __LINE__);
13601 			tp->t_flags |= TF_DELACK;
13602 		} else {
13603 			rack->r_wanted_output = 1;
13604 			tp->t_flags |= TF_ACKNOW;
13605 		}
13606 
13607 		tcp_ecn_input_syn_sent(tp, thflags, iptos);
13608 
13609 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
13610 			/*
13611 			 * We advance snd_una for the
13612 			 * fast open case. If th_ack is
13613 			 * acknowledging data beyond
13614 			 * snd_una we can't just call
13615 			 * ack-processing since the
13616 			 * data stream in our send-map
13617 			 * will start at snd_una + 1 (one
13618 			 * beyond the SYN). If its just
13619 			 * equal we don't need to do that
13620 			 * and there is no send_map.
13621 			 */
13622 			tp->snd_una++;
13623 			if (tfo_partial && (SEQ_GT(tp->snd_max, tp->snd_una))) {
13624 				/*
13625 				 * We sent a SYN with data, and thus have a
13626 				 * sendmap entry with a SYN set. Lets find it
13627 				 * and take off the send bit and the byte and
13628 				 * set it up to be what we send (send it next).
13629 				 */
13630 				struct rack_sendmap *rsm;
13631 
13632 				rsm = tqhash_min(rack->r_ctl.tqh);
13633 				if (rsm) {
13634 					if (rsm->r_flags & RACK_HAS_SYN) {
13635 						rsm->r_flags &= ~RACK_HAS_SYN;
13636 						rsm->r_start++;
13637 					}
13638 					rack->r_ctl.rc_resend = rsm;
13639 				}
13640 			}
13641 		}
13642 		/*
13643 		 * Received <SYN,ACK> in SYN_SENT[*] state. Transitions:
13644 		 * SYN_SENT  --> ESTABLISHED SYN_SENT* --> FIN_WAIT_1
13645 		 */
13646 		tp->t_starttime = ticks;
13647 		if (tp->t_flags & TF_NEEDFIN) {
13648 			tcp_state_change(tp, TCPS_FIN_WAIT_1);
13649 			tp->t_flags &= ~TF_NEEDFIN;
13650 			thflags &= ~TH_SYN;
13651 		} else {
13652 			tcp_state_change(tp, TCPS_ESTABLISHED);
13653 			TCP_PROBE5(connect__established, NULL, tp,
13654 			    mtod(m, const char *), tp, th);
13655 			rack_cc_conn_init(tp);
13656 		}
13657 	} else {
13658 		/*
13659 		 * Received initial SYN in SYN-SENT[*] state => simultaneous
13660 		 * open.  If segment contains CC option and there is a
13661 		 * cached CC, apply TAO test. If it succeeds, connection is *
13662 		 * half-synchronized. Otherwise, do 3-way handshake:
13663 		 * SYN-SENT -> SYN-RECEIVED SYN-SENT* -> SYN-RECEIVED* If
13664 		 * there was no CC option, clear cached CC value.
13665 		 */
13666 		tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN | TF_SONOTCONN);
13667 		tcp_state_change(tp, TCPS_SYN_RECEIVED);
13668 	}
13669 	/*
13670 	 * Advance th->th_seq to correspond to first data byte. If data,
13671 	 * trim to stay within window, dropping FIN if necessary.
13672 	 */
13673 	th->th_seq++;
13674 	if (tlen > tp->rcv_wnd) {
13675 		todrop = tlen - tp->rcv_wnd;
13676 		m_adj(m, -todrop);
13677 		tlen = tp->rcv_wnd;
13678 		thflags &= ~TH_FIN;
13679 		KMOD_TCPSTAT_INC(tcps_rcvpackafterwin);
13680 		KMOD_TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop);
13681 	}
13682 	tp->snd_wl1 = th->th_seq - 1;
13683 	tp->rcv_up = th->th_seq;
13684 	/*
13685 	 * Client side of transaction: already sent SYN and data. If the
13686 	 * remote host used T/TCP to validate the SYN, our data will be
13687 	 * ACK'd; if so, enter normal data segment processing in the middle
13688 	 * of step 5, ack processing. Otherwise, goto step 6.
13689 	 */
13690 	if (thflags & TH_ACK) {
13691 		/* For syn-sent we need to possibly update the rtt */
13692 		if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
13693 			uint32_t t, mcts;
13694 
13695 			mcts = tcp_ts_getticks();
13696 			t = (mcts - to->to_tsecr) * HPTS_USEC_IN_MSEC;
13697 			if (!tp->t_rttlow || tp->t_rttlow > t)
13698 				tp->t_rttlow = t;
13699 			rack_log_rtt_sample_calc(rack, t, (to->to_tsecr * 1000), (mcts * 1000), 4);
13700 			tcp_rack_xmit_timer(rack, t + 1, 1, t, 0, NULL, 2);
13701 			tcp_rack_xmit_timer_commit(rack, tp);
13702 		}
13703 		if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val, orig_tlen))
13704 			return (ret_val);
13705 		/* We may have changed to FIN_WAIT_1 above */
13706 		if (tp->t_state == TCPS_FIN_WAIT_1) {
13707 			/*
13708 			 * In FIN_WAIT_1 STATE in addition to the processing
13709 			 * for the ESTABLISHED state if our FIN is now
13710 			 * acknowledged then enter FIN_WAIT_2.
13711 			 */
13712 			if (ourfinisacked) {
13713 				/*
13714 				 * If we can't receive any more data, then
13715 				 * closing user can proceed. Starting the
13716 				 * timer is contrary to the specification,
13717 				 * but if we don't get a FIN we'll hang
13718 				 * forever.
13719 				 *
13720 				 * XXXjl: we should release the tp also, and
13721 				 * use a compressed state.
13722 				 */
13723 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13724 					soisdisconnected(so);
13725 					tcp_timer_activate(tp, TT_2MSL,
13726 					    (tcp_fast_finwait2_recycle ?
13727 					    tcp_finwait2_timeout :
13728 					    TP_MAXIDLE(tp)));
13729 				}
13730 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
13731 			}
13732 		}
13733 	}
13734 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13735 	   tiwin, thflags, nxt_pkt));
13736 }
13737 
13738 /*
13739  * Return value of 1, the TCB is unlocked and most
13740  * likely gone, return value of 0, the TCP is still
13741  * locked.
13742  */
13743 static int
rack_do_syn_recv(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)13744 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
13745     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13746     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13747 {
13748 	struct tcp_rack *rack;
13749 	int32_t orig_tlen = tlen;
13750 	int32_t ret_val = 0;
13751 	int32_t ourfinisacked = 0;
13752 
13753 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13754 	ctf_calc_rwin(so, tp);
13755 	if ((thflags & TH_RST) ||
13756 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13757 		return (__ctf_process_rst(m, th, so, tp,
13758 					  &rack->r_ctl.challenge_ack_ts,
13759 					  &rack->r_ctl.challenge_ack_cnt));
13760 	if ((thflags & TH_ACK) &&
13761 	    (SEQ_LEQ(th->th_ack, tp->snd_una) ||
13762 	    SEQ_GT(th->th_ack, tp->snd_max))) {
13763 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
13764 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
13765 		return (1);
13766 	}
13767 	if (tp->t_flags & TF_FASTOPEN) {
13768 		/*
13769 		 * When a TFO connection is in SYN_RECEIVED, the
13770 		 * only valid packets are the initial SYN, a
13771 		 * retransmit/copy of the initial SYN (possibly with
13772 		 * a subset of the original data), a valid ACK, a
13773 		 * FIN, or a RST.
13774 		 */
13775 		if ((thflags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
13776 			tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
13777 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
13778 			return (1);
13779 		} else if (thflags & TH_SYN) {
13780 			/* non-initial SYN is ignored */
13781 			if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT) ||
13782 			    (rack->r_ctl.rc_hpts_flags & PACE_TMR_TLP) ||
13783 			    (rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK)) {
13784 				ctf_do_drop(m, NULL);
13785 				return (0);
13786 			}
13787 		} else if (!(thflags & (TH_ACK | TH_FIN | TH_RST))) {
13788 			ctf_do_drop(m, NULL);
13789 			return (0);
13790 		}
13791 	}
13792 
13793 	/*
13794 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
13795 	 * it's less than ts_recent, drop it.
13796 	 */
13797 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
13798 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
13799 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13800 			return (ret_val);
13801 	}
13802 	/*
13803 	 * In the SYN-RECEIVED state, validate that the packet belongs to
13804 	 * this connection before trimming the data to fit the receive
13805 	 * window.  Check the sequence number versus IRS since we know the
13806 	 * sequence numbers haven't wrapped.  This is a partial fix for the
13807 	 * "LAND" DoS attack.
13808 	 */
13809 	if (SEQ_LT(th->th_seq, tp->irs)) {
13810 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
13811 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
13812 		return (1);
13813 	}
13814 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
13815 			      &rack->r_ctl.challenge_ack_ts,
13816 			      &rack->r_ctl.challenge_ack_cnt)) {
13817 		return (ret_val);
13818 	}
13819 	/*
13820 	 * If last ACK falls within this segment's sequence numbers, record
13821 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
13822 	 * from the latest proposal of the tcplw@cray.com list (Braden
13823 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
13824 	 * with our earlier PAWS tests, so this check should be solely
13825 	 * predicated on the sequence space of this segment. 3) That we
13826 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
13827 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
13828 	 * SEG.Len, This modified check allows us to overcome RFC1323's
13829 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
13830 	 * p.869. In such cases, we can still calculate the RTT correctly
13831 	 * when RCV.NXT == Last.ACK.Sent.
13832 	 */
13833 	if ((to->to_flags & TOF_TS) != 0 &&
13834 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
13835 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
13836 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
13837 		tp->ts_recent_age = tcp_ts_getticks();
13838 		tp->ts_recent = to->to_tsval;
13839 	}
13840 	tp->snd_wnd = tiwin;
13841 	rack_validate_fo_sendwin_up(tp, rack);
13842 	/*
13843 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
13844 	 * is on (half-synchronized state), then queue data for later
13845 	 * processing; else drop segment and return.
13846 	 */
13847 	if ((thflags & TH_ACK) == 0) {
13848 		if (tp->t_flags & TF_FASTOPEN) {
13849 			rack_cc_conn_init(tp);
13850 		}
13851 		return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13852 		    tiwin, thflags, nxt_pkt));
13853 	}
13854 	KMOD_TCPSTAT_INC(tcps_connects);
13855 	if (tp->t_flags & TF_SONOTCONN) {
13856 		tp->t_flags &= ~TF_SONOTCONN;
13857 		soisconnected(so);
13858 	}
13859 	/* Do window scaling? */
13860 	if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
13861 	    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
13862 		tp->rcv_scale = tp->request_r_scale;
13863 	}
13864 	/*
13865 	 * Make transitions: SYN-RECEIVED  -> ESTABLISHED SYN-RECEIVED* ->
13866 	 * FIN-WAIT-1
13867 	 */
13868 	tp->t_starttime = ticks;
13869 	if ((tp->t_flags & TF_FASTOPEN) && tp->t_tfo_pending) {
13870 		tcp_fastopen_decrement_counter(tp->t_tfo_pending);
13871 		tp->t_tfo_pending = NULL;
13872 	}
13873 	if (tp->t_flags & TF_NEEDFIN) {
13874 		tcp_state_change(tp, TCPS_FIN_WAIT_1);
13875 		tp->t_flags &= ~TF_NEEDFIN;
13876 	} else {
13877 		tcp_state_change(tp, TCPS_ESTABLISHED);
13878 		TCP_PROBE5(accept__established, NULL, tp,
13879 		    mtod(m, const char *), tp, th);
13880 		/*
13881 		 * TFO connections call cc_conn_init() during SYN
13882 		 * processing.  Calling it again here for such connections
13883 		 * is not harmless as it would undo the snd_cwnd reduction
13884 		 * that occurs when a TFO SYN|ACK is retransmitted.
13885 		 */
13886 		if (!(tp->t_flags & TF_FASTOPEN))
13887 			rack_cc_conn_init(tp);
13888 	}
13889 	/*
13890 	 * Account for the ACK of our SYN prior to
13891 	 * regular ACK processing below, except for
13892 	 * simultaneous SYN, which is handled later.
13893 	 */
13894 	if (SEQ_GT(th->th_ack, tp->snd_una) && !(tp->t_flags & TF_NEEDSYN))
13895 		tp->snd_una++;
13896 	/*
13897 	 * If segment contains data or ACK, will call tcp_reass() later; if
13898 	 * not, do so now to pass queued data to user.
13899 	 */
13900 	if (tlen == 0 && (thflags & TH_FIN) == 0) {
13901 		(void) tcp_reass(tp, (struct tcphdr *)0, NULL, 0,
13902 		    (struct mbuf *)0);
13903 		if (tp->t_flags & TF_WAKESOR) {
13904 			tp->t_flags &= ~TF_WAKESOR;
13905 			/* NB: sorwakeup_locked() does an implicit unlock. */
13906 			sorwakeup_locked(so);
13907 		}
13908 	}
13909 	tp->snd_wl1 = th->th_seq - 1;
13910 	/* For syn-recv we need to possibly update the rtt */
13911 	if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
13912 		uint32_t t, mcts;
13913 
13914 		mcts = tcp_ts_getticks();
13915 		t = (mcts - to->to_tsecr) * HPTS_USEC_IN_MSEC;
13916 		if (!tp->t_rttlow || tp->t_rttlow > t)
13917 			tp->t_rttlow = t;
13918 		rack_log_rtt_sample_calc(rack, t, (to->to_tsecr * 1000), (mcts * 1000), 5);
13919 		tcp_rack_xmit_timer(rack, t + 1, 1, t, 0, NULL, 2);
13920 		tcp_rack_xmit_timer_commit(rack, tp);
13921 	}
13922 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val, orig_tlen)) {
13923 		return (ret_val);
13924 	}
13925 	if (tp->t_state == TCPS_FIN_WAIT_1) {
13926 		/* We could have went to FIN_WAIT_1 (or EST) above */
13927 		/*
13928 		 * In FIN_WAIT_1 STATE in addition to the processing for the
13929 		 * ESTABLISHED state if our FIN is now acknowledged then
13930 		 * enter FIN_WAIT_2.
13931 		 */
13932 		if (ourfinisacked) {
13933 			/*
13934 			 * If we can't receive any more data, then closing
13935 			 * user can proceed. Starting the timer is contrary
13936 			 * to the specification, but if we don't get a FIN
13937 			 * we'll hang forever.
13938 			 *
13939 			 * XXXjl: we should release the tp also, and use a
13940 			 * compressed state.
13941 			 */
13942 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13943 				soisdisconnected(so);
13944 				tcp_timer_activate(tp, TT_2MSL,
13945 				    (tcp_fast_finwait2_recycle ?
13946 				    tcp_finwait2_timeout :
13947 				    TP_MAXIDLE(tp)));
13948 			}
13949 			tcp_state_change(tp, TCPS_FIN_WAIT_2);
13950 		}
13951 	}
13952 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13953 	    tiwin, thflags, nxt_pkt));
13954 }
13955 
13956 /*
13957  * Return value of 1, the TCB is unlocked and most
13958  * likely gone, return value of 0, the TCP is still
13959  * locked.
13960  */
13961 static int
rack_do_established(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)13962 rack_do_established(struct mbuf *m, struct tcphdr *th, struct socket *so,
13963     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13964     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13965 {
13966 	int32_t ret_val = 0;
13967 	int32_t orig_tlen = tlen;
13968 	struct tcp_rack *rack;
13969 
13970 	/*
13971 	 * Header prediction: check for the two common cases of a
13972 	 * uni-directional data xfer.  If the packet has no control flags,
13973 	 * is in-sequence, the window didn't change and we're not
13974 	 * retransmitting, it's a candidate.  If the length is zero and the
13975 	 * ack moved forward, we're the sender side of the xfer.  Just free
13976 	 * the data acked & wake any higher level process that was blocked
13977 	 * waiting for space.  If the length is non-zero and the ack didn't
13978 	 * move, we're the receiver side.  If we're getting packets in-order
13979 	 * (the reassembly queue is empty), add the data toc The socket
13980 	 * buffer and note that we need a delayed ack. Make sure that the
13981 	 * hidden state-flags are also off. Since we check for
13982 	 * TCPS_ESTABLISHED first, it can only be TH_NEEDSYN.
13983 	 */
13984 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13985 	if (__predict_true(((to->to_flags & TOF_SACK) == 0)) &&
13986 	    __predict_true((thflags & (TH_SYN | TH_FIN | TH_RST | TH_ACK)) == TH_ACK) &&
13987 	    __predict_true(SEGQ_EMPTY(tp)) &&
13988 	    __predict_true(th->th_seq == tp->rcv_nxt)) {
13989 		if (tlen == 0) {
13990 			if (rack_fastack(m, th, so, tp, to, drop_hdrlen, tlen,
13991 			    tiwin, nxt_pkt, rack->r_ctl.rc_rcvtime)) {
13992 				return (0);
13993 			}
13994 		} else {
13995 			if (rack_do_fastnewdata(m, th, so, tp, to, drop_hdrlen, tlen,
13996 			    tiwin, nxt_pkt, iptos)) {
13997 				return (0);
13998 			}
13999 		}
14000 	}
14001 	ctf_calc_rwin(so, tp);
14002 
14003 	if ((thflags & TH_RST) ||
14004 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
14005 		return (__ctf_process_rst(m, th, so, tp,
14006 					  &rack->r_ctl.challenge_ack_ts,
14007 					  &rack->r_ctl.challenge_ack_cnt));
14008 
14009 	/*
14010 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
14011 	 * synchronized state.
14012 	 */
14013 	if (thflags & TH_SYN) {
14014 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
14015 		return (ret_val);
14016 	}
14017 	/*
14018 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
14019 	 * it's less than ts_recent, drop it.
14020 	 */
14021 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
14022 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
14023 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
14024 			return (ret_val);
14025 	}
14026 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
14027 			      &rack->r_ctl.challenge_ack_ts,
14028 			      &rack->r_ctl.challenge_ack_cnt)) {
14029 		return (ret_val);
14030 	}
14031 	/*
14032 	 * If last ACK falls within this segment's sequence numbers, record
14033 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
14034 	 * from the latest proposal of the tcplw@cray.com list (Braden
14035 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
14036 	 * with our earlier PAWS tests, so this check should be solely
14037 	 * predicated on the sequence space of this segment. 3) That we
14038 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
14039 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
14040 	 * SEG.Len, This modified check allows us to overcome RFC1323's
14041 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
14042 	 * p.869. In such cases, we can still calculate the RTT correctly
14043 	 * when RCV.NXT == Last.ACK.Sent.
14044 	 */
14045 	if ((to->to_flags & TOF_TS) != 0 &&
14046 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
14047 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
14048 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
14049 		tp->ts_recent_age = tcp_ts_getticks();
14050 		tp->ts_recent = to->to_tsval;
14051 	}
14052 	/*
14053 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
14054 	 * is on (half-synchronized state), then queue data for later
14055 	 * processing; else drop segment and return.
14056 	 */
14057 	if ((thflags & TH_ACK) == 0) {
14058 		if (tp->t_flags & TF_NEEDSYN) {
14059 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
14060 			    tiwin, thflags, nxt_pkt));
14061 
14062 		} else if (tp->t_flags & TF_ACKNOW) {
14063 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
14064 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
14065 			return (ret_val);
14066 		} else {
14067 			ctf_do_drop(m, NULL);
14068 			return (0);
14069 		}
14070 	}
14071 	/*
14072 	 * Ack processing.
14073 	 */
14074 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val, orig_tlen)) {
14075 		return (ret_val);
14076 	}
14077 	if (sbavail(&so->so_snd)) {
14078 		if (ctf_progress_timeout_check(tp, true)) {
14079 			rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
14080 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
14081 			return (1);
14082 		}
14083 	}
14084 	/* State changes only happen in rack_process_data() */
14085 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
14086 	    tiwin, thflags, nxt_pkt));
14087 }
14088 
14089 /*
14090  * Return value of 1, the TCB is unlocked and most
14091  * likely gone, return value of 0, the TCP is still
14092  * locked.
14093  */
14094 static int
rack_do_close_wait(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)14095 rack_do_close_wait(struct mbuf *m, struct tcphdr *th, struct socket *so,
14096     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
14097     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
14098 {
14099 	int32_t ret_val = 0;
14100 	int32_t orig_tlen = tlen;
14101 	struct tcp_rack *rack;
14102 
14103 	rack = (struct tcp_rack *)tp->t_fb_ptr;
14104 	ctf_calc_rwin(so, tp);
14105 	if ((thflags & TH_RST) ||
14106 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
14107 		return (__ctf_process_rst(m, th, so, tp,
14108 					  &rack->r_ctl.challenge_ack_ts,
14109 					  &rack->r_ctl.challenge_ack_cnt));
14110 	/*
14111 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
14112 	 * synchronized state.
14113 	 */
14114 	if (thflags & TH_SYN) {
14115 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
14116 		return (ret_val);
14117 	}
14118 	/*
14119 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
14120 	 * it's less than ts_recent, drop it.
14121 	 */
14122 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
14123 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
14124 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
14125 			return (ret_val);
14126 	}
14127 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
14128 			      &rack->r_ctl.challenge_ack_ts,
14129 			      &rack->r_ctl.challenge_ack_cnt)) {
14130 		return (ret_val);
14131 	}
14132 	/*
14133 	 * If last ACK falls within this segment's sequence numbers, record
14134 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
14135 	 * from the latest proposal of the tcplw@cray.com list (Braden
14136 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
14137 	 * with our earlier PAWS tests, so this check should be solely
14138 	 * predicated on the sequence space of this segment. 3) That we
14139 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
14140 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
14141 	 * SEG.Len, This modified check allows us to overcome RFC1323's
14142 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
14143 	 * p.869. In such cases, we can still calculate the RTT correctly
14144 	 * when RCV.NXT == Last.ACK.Sent.
14145 	 */
14146 	if ((to->to_flags & TOF_TS) != 0 &&
14147 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
14148 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
14149 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
14150 		tp->ts_recent_age = tcp_ts_getticks();
14151 		tp->ts_recent = to->to_tsval;
14152 	}
14153 	/*
14154 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
14155 	 * is on (half-synchronized state), then queue data for later
14156 	 * processing; else drop segment and return.
14157 	 */
14158 	if ((thflags & TH_ACK) == 0) {
14159 		if (tp->t_flags & TF_NEEDSYN) {
14160 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
14161 			    tiwin, thflags, nxt_pkt));
14162 
14163 		} else if (tp->t_flags & TF_ACKNOW) {
14164 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
14165 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
14166 			return (ret_val);
14167 		} else {
14168 			ctf_do_drop(m, NULL);
14169 			return (0);
14170 		}
14171 	}
14172 	/*
14173 	 * Ack processing.
14174 	 */
14175 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val, orig_tlen)) {
14176 		return (ret_val);
14177 	}
14178 	if (sbavail(&so->so_snd)) {
14179 		if (ctf_progress_timeout_check(tp, true)) {
14180 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
14181 						tp, tick, PROGRESS_DROP, __LINE__);
14182 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
14183 			return (1);
14184 		}
14185 	}
14186 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
14187 	    tiwin, thflags, nxt_pkt));
14188 }
14189 
14190 static int
rack_check_data_after_close(struct mbuf * m,struct tcpcb * tp,int32_t * tlen,struct tcphdr * th,struct socket * so)14191 rack_check_data_after_close(struct mbuf *m,
14192     struct tcpcb *tp, int32_t *tlen, struct tcphdr *th, struct socket *so)
14193 {
14194 	struct tcp_rack *rack;
14195 
14196 	rack = (struct tcp_rack *)tp->t_fb_ptr;
14197 	if (rack->rc_allow_data_af_clo == 0) {
14198 	close_now:
14199 		tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
14200 		/* tcp_close will kill the inp pre-log the Reset */
14201 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
14202 		tp = tcp_close(tp);
14203 		KMOD_TCPSTAT_INC(tcps_rcvafterclose);
14204 		ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, (*tlen));
14205 		return (1);
14206 	}
14207 	if (sbavail(&so->so_snd) == 0)
14208 		goto close_now;
14209 	/* Ok we allow data that is ignored and a followup reset */
14210 	tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
14211 	tp->rcv_nxt = th->th_seq + *tlen;
14212 	tp->t_flags2 |= TF2_DROP_AF_DATA;
14213 	rack->r_wanted_output = 1;
14214 	*tlen = 0;
14215 	return (0);
14216 }
14217 
14218 /*
14219  * Return value of 1, the TCB is unlocked and most
14220  * likely gone, return value of 0, the TCP is still
14221  * locked.
14222  */
14223 static int
rack_do_fin_wait_1(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)14224 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, struct socket *so,
14225     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
14226     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
14227 {
14228 	int32_t ret_val = 0;
14229 	int32_t orig_tlen = tlen;
14230 	int32_t ourfinisacked = 0;
14231 	struct tcp_rack *rack;
14232 
14233 	rack = (struct tcp_rack *)tp->t_fb_ptr;
14234 	ctf_calc_rwin(so, tp);
14235 
14236 	if ((thflags & TH_RST) ||
14237 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
14238 		return (__ctf_process_rst(m, th, so, tp,
14239 					  &rack->r_ctl.challenge_ack_ts,
14240 					  &rack->r_ctl.challenge_ack_cnt));
14241 	/*
14242 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
14243 	 * synchronized state.
14244 	 */
14245 	if (thflags & TH_SYN) {
14246 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
14247 		return (ret_val);
14248 	}
14249 	/*
14250 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
14251 	 * it's less than ts_recent, drop it.
14252 	 */
14253 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
14254 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
14255 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
14256 			return (ret_val);
14257 	}
14258 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
14259 			      &rack->r_ctl.challenge_ack_ts,
14260 			      &rack->r_ctl.challenge_ack_cnt)) {
14261 		return (ret_val);
14262 	}
14263 	/*
14264 	 * If new data are received on a connection after the user processes
14265 	 * are gone, then RST the other end.
14266 	 */
14267 	if ((tp->t_flags & TF_CLOSED) && tlen &&
14268 	    rack_check_data_after_close(m, tp, &tlen, th, so))
14269 		return (1);
14270 	/*
14271 	 * If last ACK falls within this segment's sequence numbers, record
14272 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
14273 	 * from the latest proposal of the tcplw@cray.com list (Braden
14274 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
14275 	 * with our earlier PAWS tests, so this check should be solely
14276 	 * predicated on the sequence space of this segment. 3) That we
14277 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
14278 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
14279 	 * SEG.Len, This modified check allows us to overcome RFC1323's
14280 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
14281 	 * p.869. In such cases, we can still calculate the RTT correctly
14282 	 * when RCV.NXT == Last.ACK.Sent.
14283 	 */
14284 	if ((to->to_flags & TOF_TS) != 0 &&
14285 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
14286 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
14287 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
14288 		tp->ts_recent_age = tcp_ts_getticks();
14289 		tp->ts_recent = to->to_tsval;
14290 	}
14291 	/*
14292 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
14293 	 * is on (half-synchronized state), then queue data for later
14294 	 * processing; else drop segment and return.
14295 	 */
14296 	if ((thflags & TH_ACK) == 0) {
14297 		if (tp->t_flags & TF_NEEDSYN) {
14298 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
14299 			    tiwin, thflags, nxt_pkt));
14300 		} else if (tp->t_flags & TF_ACKNOW) {
14301 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
14302 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
14303 			return (ret_val);
14304 		} else {
14305 			ctf_do_drop(m, NULL);
14306 			return (0);
14307 		}
14308 	}
14309 	/*
14310 	 * Ack processing.
14311 	 */
14312 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val, orig_tlen)) {
14313 		return (ret_val);
14314 	}
14315 	if (ourfinisacked) {
14316 		/*
14317 		 * If we can't receive any more data, then closing user can
14318 		 * proceed. Starting the timer is contrary to the
14319 		 * specification, but if we don't get a FIN we'll hang
14320 		 * forever.
14321 		 *
14322 		 * XXXjl: we should release the tp also, and use a
14323 		 * compressed state.
14324 		 */
14325 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
14326 			soisdisconnected(so);
14327 			tcp_timer_activate(tp, TT_2MSL,
14328 			    (tcp_fast_finwait2_recycle ?
14329 			    tcp_finwait2_timeout :
14330 			    TP_MAXIDLE(tp)));
14331 		}
14332 		tcp_state_change(tp, TCPS_FIN_WAIT_2);
14333 	}
14334 	if (sbavail(&so->so_snd)) {
14335 		if (ctf_progress_timeout_check(tp, true)) {
14336 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
14337 						tp, tick, PROGRESS_DROP, __LINE__);
14338 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
14339 			return (1);
14340 		}
14341 	}
14342 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
14343 	    tiwin, thflags, nxt_pkt));
14344 }
14345 
14346 /*
14347  * Return value of 1, the TCB is unlocked and most
14348  * likely gone, return value of 0, the TCP is still
14349  * locked.
14350  */
14351 static int
rack_do_closing(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)14352 rack_do_closing(struct mbuf *m, struct tcphdr *th, struct socket *so,
14353     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
14354     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
14355 {
14356 	int32_t ret_val = 0;
14357 	int32_t orig_tlen = tlen;
14358 	int32_t ourfinisacked = 0;
14359 	struct tcp_rack *rack;
14360 
14361 	rack = (struct tcp_rack *)tp->t_fb_ptr;
14362 	ctf_calc_rwin(so, tp);
14363 
14364 	if ((thflags & TH_RST) ||
14365 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
14366 		return (__ctf_process_rst(m, th, so, tp,
14367 					  &rack->r_ctl.challenge_ack_ts,
14368 					  &rack->r_ctl.challenge_ack_cnt));
14369 	/*
14370 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
14371 	 * synchronized state.
14372 	 */
14373 	if (thflags & TH_SYN) {
14374 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
14375 		return (ret_val);
14376 	}
14377 	/*
14378 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
14379 	 * it's less than ts_recent, drop it.
14380 	 */
14381 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
14382 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
14383 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
14384 			return (ret_val);
14385 	}
14386 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
14387 			      &rack->r_ctl.challenge_ack_ts,
14388 			      &rack->r_ctl.challenge_ack_cnt)) {
14389 		return (ret_val);
14390 	}
14391 	/*
14392 	 * If last ACK falls within this segment's sequence numbers, record
14393 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
14394 	 * from the latest proposal of the tcplw@cray.com list (Braden
14395 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
14396 	 * with our earlier PAWS tests, so this check should be solely
14397 	 * predicated on the sequence space of this segment. 3) That we
14398 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
14399 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
14400 	 * SEG.Len, This modified check allows us to overcome RFC1323's
14401 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
14402 	 * p.869. In such cases, we can still calculate the RTT correctly
14403 	 * when RCV.NXT == Last.ACK.Sent.
14404 	 */
14405 	if ((to->to_flags & TOF_TS) != 0 &&
14406 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
14407 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
14408 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
14409 		tp->ts_recent_age = tcp_ts_getticks();
14410 		tp->ts_recent = to->to_tsval;
14411 	}
14412 	/*
14413 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
14414 	 * is on (half-synchronized state), then queue data for later
14415 	 * processing; else drop segment and return.
14416 	 */
14417 	if ((thflags & TH_ACK) == 0) {
14418 		if (tp->t_flags & TF_NEEDSYN) {
14419 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
14420 			    tiwin, thflags, nxt_pkt));
14421 		} else if (tp->t_flags & TF_ACKNOW) {
14422 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
14423 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
14424 			return (ret_val);
14425 		} else {
14426 			ctf_do_drop(m, NULL);
14427 			return (0);
14428 		}
14429 	}
14430 	/*
14431 	 * Ack processing.
14432 	 */
14433 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val, orig_tlen)) {
14434 		return (ret_val);
14435 	}
14436 	if (ourfinisacked) {
14437 		tcp_twstart(tp);
14438 		m_freem(m);
14439 		return (1);
14440 	}
14441 	if (sbavail(&so->so_snd)) {
14442 		if (ctf_progress_timeout_check(tp, true)) {
14443 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
14444 						tp, tick, PROGRESS_DROP, __LINE__);
14445 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
14446 			return (1);
14447 		}
14448 	}
14449 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
14450 	    tiwin, thflags, nxt_pkt));
14451 }
14452 
14453 /*
14454  * Return value of 1, the TCB is unlocked and most
14455  * likely gone, return value of 0, the TCP is still
14456  * locked.
14457  */
14458 static int
rack_do_lastack(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)14459 rack_do_lastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
14460     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
14461     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
14462 {
14463 	int32_t ret_val = 0;
14464 	int32_t orig_tlen;
14465 	int32_t ourfinisacked = 0;
14466 	struct tcp_rack *rack;
14467 
14468 	rack = (struct tcp_rack *)tp->t_fb_ptr;
14469 	ctf_calc_rwin(so, tp);
14470 
14471 	if ((thflags & TH_RST) ||
14472 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
14473 		return (__ctf_process_rst(m, th, so, tp,
14474 					  &rack->r_ctl.challenge_ack_ts,
14475 					  &rack->r_ctl.challenge_ack_cnt));
14476 	/*
14477 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
14478 	 * synchronized state.
14479 	 */
14480 	if (thflags & TH_SYN) {
14481 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
14482 		return (ret_val);
14483 	}
14484 	/*
14485 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
14486 	 * it's less than ts_recent, drop it.
14487 	 */
14488 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
14489 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
14490 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
14491 			return (ret_val);
14492 	}
14493 	orig_tlen = tlen;
14494 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
14495 			      &rack->r_ctl.challenge_ack_ts,
14496 			      &rack->r_ctl.challenge_ack_cnt)) {
14497 		return (ret_val);
14498 	}
14499 	/*
14500 	 * If last ACK falls within this segment's sequence numbers, record
14501 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
14502 	 * from the latest proposal of the tcplw@cray.com list (Braden
14503 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
14504 	 * with our earlier PAWS tests, so this check should be solely
14505 	 * predicated on the sequence space of this segment. 3) That we
14506 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
14507 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
14508 	 * SEG.Len, This modified check allows us to overcome RFC1323's
14509 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
14510 	 * p.869. In such cases, we can still calculate the RTT correctly
14511 	 * when RCV.NXT == Last.ACK.Sent.
14512 	 */
14513 	if ((to->to_flags & TOF_TS) != 0 &&
14514 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
14515 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
14516 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
14517 		tp->ts_recent_age = tcp_ts_getticks();
14518 		tp->ts_recent = to->to_tsval;
14519 	}
14520 	/*
14521 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
14522 	 * is on (half-synchronized state), then queue data for later
14523 	 * processing; else drop segment and return.
14524 	 */
14525 	if ((thflags & TH_ACK) == 0) {
14526 		if (tp->t_flags & TF_NEEDSYN) {
14527 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
14528 			    tiwin, thflags, nxt_pkt));
14529 		} else if (tp->t_flags & TF_ACKNOW) {
14530 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
14531 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
14532 			return (ret_val);
14533 		} else {
14534 			ctf_do_drop(m, NULL);
14535 			return (0);
14536 		}
14537 	}
14538 	/*
14539 	 * case TCPS_LAST_ACK: Ack processing.
14540 	 */
14541 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val, orig_tlen)) {
14542 		return (ret_val);
14543 	}
14544 	if (ourfinisacked) {
14545 		tp = tcp_close(tp);
14546 		ctf_do_drop(m, tp);
14547 		return (1);
14548 	}
14549 	if (sbavail(&so->so_snd)) {
14550 		if (ctf_progress_timeout_check(tp, true)) {
14551 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
14552 						tp, tick, PROGRESS_DROP, __LINE__);
14553 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
14554 			return (1);
14555 		}
14556 	}
14557 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
14558 	    tiwin, thflags, nxt_pkt));
14559 }
14560 
14561 /*
14562  * Return value of 1, the TCB is unlocked and most
14563  * likely gone, return value of 0, the TCP is still
14564  * locked.
14565  */
14566 static int
rack_do_fin_wait_2(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)14567 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, struct socket *so,
14568     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
14569     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
14570 {
14571 	int32_t ret_val = 0;
14572 	int32_t orig_tlen = tlen;
14573 	int32_t ourfinisacked = 0;
14574 	struct tcp_rack *rack;
14575 
14576 	rack = (struct tcp_rack *)tp->t_fb_ptr;
14577 	ctf_calc_rwin(so, tp);
14578 
14579 	/* Reset receive buffer auto scaling when not in bulk receive mode. */
14580 	if ((thflags & TH_RST) ||
14581 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
14582 		return (__ctf_process_rst(m, th, so, tp,
14583 					  &rack->r_ctl.challenge_ack_ts,
14584 					  &rack->r_ctl.challenge_ack_cnt));
14585 	/*
14586 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
14587 	 * synchronized state.
14588 	 */
14589 	if (thflags & TH_SYN) {
14590 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
14591 		return (ret_val);
14592 	}
14593 	/*
14594 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
14595 	 * it's less than ts_recent, drop it.
14596 	 */
14597 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
14598 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
14599 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
14600 			return (ret_val);
14601 	}
14602 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
14603 			      &rack->r_ctl.challenge_ack_ts,
14604 			      &rack->r_ctl.challenge_ack_cnt)) {
14605 		return (ret_val);
14606 	}
14607 	/*
14608 	 * If new data are received on a connection after the user processes
14609 	 * are gone, then RST the other end.
14610 	 */
14611 	if ((tp->t_flags & TF_CLOSED) && tlen &&
14612 	    rack_check_data_after_close(m, tp, &tlen, th, so))
14613 		return (1);
14614 	/*
14615 	 * If last ACK falls within this segment's sequence numbers, record
14616 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
14617 	 * from the latest proposal of the tcplw@cray.com list (Braden
14618 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
14619 	 * with our earlier PAWS tests, so this check should be solely
14620 	 * predicated on the sequence space of this segment. 3) That we
14621 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
14622 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
14623 	 * SEG.Len, This modified check allows us to overcome RFC1323's
14624 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
14625 	 * p.869. In such cases, we can still calculate the RTT correctly
14626 	 * when RCV.NXT == Last.ACK.Sent.
14627 	 */
14628 	if ((to->to_flags & TOF_TS) != 0 &&
14629 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
14630 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
14631 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
14632 		tp->ts_recent_age = tcp_ts_getticks();
14633 		tp->ts_recent = to->to_tsval;
14634 	}
14635 	/*
14636 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
14637 	 * is on (half-synchronized state), then queue data for later
14638 	 * processing; else drop segment and return.
14639 	 */
14640 	if ((thflags & TH_ACK) == 0) {
14641 		if (tp->t_flags & TF_NEEDSYN) {
14642 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
14643 			    tiwin, thflags, nxt_pkt));
14644 		} else if (tp->t_flags & TF_ACKNOW) {
14645 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
14646 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
14647 			return (ret_val);
14648 		} else {
14649 			ctf_do_drop(m, NULL);
14650 			return (0);
14651 		}
14652 	}
14653 	/*
14654 	 * Ack processing.
14655 	 */
14656 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val, orig_tlen)) {
14657 		return (ret_val);
14658 	}
14659 	if (sbavail(&so->so_snd)) {
14660 		if (ctf_progress_timeout_check(tp, true)) {
14661 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
14662 						tp, tick, PROGRESS_DROP, __LINE__);
14663 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
14664 			return (1);
14665 		}
14666 	}
14667 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
14668 	    tiwin, thflags, nxt_pkt));
14669 }
14670 
14671 static void inline
rack_clear_rate_sample(struct tcp_rack * rack)14672 rack_clear_rate_sample(struct tcp_rack *rack)
14673 {
14674 	rack->r_ctl.rack_rs.rs_flags = RACK_RTT_EMPTY;
14675 	rack->r_ctl.rack_rs.rs_rtt_cnt = 0;
14676 	rack->r_ctl.rack_rs.rs_rtt_tot = 0;
14677 }
14678 
14679 static void
rack_set_pace_segments(struct tcpcb * tp,struct tcp_rack * rack,uint32_t line,uint64_t * fill_override)14680 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line, uint64_t *fill_override)
14681 {
14682 	uint64_t bw_est, rate_wanted;
14683 	int chged = 0;
14684 	uint32_t user_max, orig_min, orig_max;
14685 
14686 #ifdef TCP_REQUEST_TRK
14687 	if (rack->rc_hybrid_mode &&
14688 	    (rack->r_ctl.rc_pace_max_segs != 0) &&
14689 	    (rack_hybrid_allow_set_maxseg == 1) &&
14690 	    (rack->r_ctl.rc_last_sft != NULL)) {
14691 		rack->r_ctl.rc_last_sft->hybrid_flags &= ~TCP_HYBRID_PACING_SETMSS;
14692 		return;
14693 	}
14694 #endif
14695 	orig_min = rack->r_ctl.rc_pace_min_segs;
14696 	orig_max = rack->r_ctl.rc_pace_max_segs;
14697 	user_max = ctf_fixed_maxseg(tp) * rack->rc_user_set_max_segs;
14698 	if (ctf_fixed_maxseg(tp) != rack->r_ctl.rc_pace_min_segs)
14699 		chged = 1;
14700 	rack->r_ctl.rc_pace_min_segs = ctf_fixed_maxseg(tp);
14701 	if (rack->use_fixed_rate || rack->rc_force_max_seg) {
14702 		if (user_max != rack->r_ctl.rc_pace_max_segs)
14703 			chged = 1;
14704 	}
14705 	if (rack->rc_force_max_seg) {
14706 		rack->r_ctl.rc_pace_max_segs = user_max;
14707 	} else if (rack->use_fixed_rate) {
14708 		bw_est = rack_get_bw(rack);
14709 		if ((rack->r_ctl.crte == NULL) ||
14710 		    (bw_est != rack->r_ctl.crte->rate)) {
14711 			rack->r_ctl.rc_pace_max_segs = user_max;
14712 		} else {
14713 			/* We are pacing right at the hardware rate */
14714 			uint32_t segsiz, pace_one;
14715 
14716 			if (rack_pace_one_seg ||
14717 			    (rack->r_ctl.rc_user_set_min_segs == 1))
14718 				pace_one = 1;
14719 			else
14720 				pace_one = 0;
14721 			segsiz = min(ctf_fixed_maxseg(tp),
14722 				     rack->r_ctl.rc_pace_min_segs);
14723 			rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size_w_divisor(
14724 				tp, bw_est, segsiz, pace_one,
14725 				rack->r_ctl.crte, NULL, rack->r_ctl.pace_len_divisor);
14726 		}
14727 	} else if (rack->rc_always_pace) {
14728 		if (rack->r_ctl.gp_bw ||
14729 		    rack->r_ctl.init_rate) {
14730 			/* We have a rate of some sort set */
14731 			uint32_t  orig;
14732 
14733 			bw_est = rack_get_bw(rack);
14734 			orig = rack->r_ctl.rc_pace_max_segs;
14735 			if (fill_override)
14736 				rate_wanted = *fill_override;
14737 			else
14738 				rate_wanted = rack_get_gp_est(rack);
14739 			if (rate_wanted) {
14740 				/* We have something */
14741 				rack->r_ctl.rc_pace_max_segs = rack_get_pacing_len(rack,
14742 										   rate_wanted,
14743 										   ctf_fixed_maxseg(rack->rc_tp));
14744 			} else
14745 				rack->r_ctl.rc_pace_max_segs = rack->r_ctl.rc_pace_min_segs;
14746 			if (orig != rack->r_ctl.rc_pace_max_segs)
14747 				chged = 1;
14748 		} else if ((rack->r_ctl.gp_bw == 0) &&
14749 			   (rack->r_ctl.rc_pace_max_segs == 0)) {
14750 			/*
14751 			 * If we have nothing limit us to bursting
14752 			 * out IW sized pieces.
14753 			 */
14754 			chged = 1;
14755 			rack->r_ctl.rc_pace_max_segs = rc_init_window(rack);
14756 		}
14757 	}
14758 	if (rack->r_ctl.rc_pace_max_segs > PACE_MAX_IP_BYTES) {
14759 		chged = 1;
14760 		rack->r_ctl.rc_pace_max_segs = PACE_MAX_IP_BYTES;
14761 	}
14762 	if (chged)
14763 		rack_log_type_pacing_sizes(tp, rack, orig_min, orig_max, line, 2);
14764 }
14765 
14766 
14767 static void
rack_init_fsb_block(struct tcpcb * tp,struct tcp_rack * rack,int32_t flags)14768 rack_init_fsb_block(struct tcpcb *tp, struct tcp_rack *rack, int32_t flags)
14769 {
14770 #ifdef INET6
14771 	struct ip6_hdr *ip6 = NULL;
14772 #endif
14773 #ifdef INET
14774 	struct ip *ip = NULL;
14775 #endif
14776 	struct udphdr *udp = NULL;
14777 
14778 	/* Ok lets fill in the fast block, it can only be used with no IP options! */
14779 #ifdef INET6
14780 	if (rack->r_is_v6) {
14781 		rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
14782 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
14783 		if (tp->t_port) {
14784 			rack->r_ctl.fsb.tcp_ip_hdr_len += sizeof(struct udphdr);
14785 			udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
14786 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
14787 			udp->uh_dport = tp->t_port;
14788 			rack->r_ctl.fsb.udp = udp;
14789 			rack->r_ctl.fsb.th = (struct tcphdr *)(udp + 1);
14790 		} else
14791 		{
14792 			rack->r_ctl.fsb.th = (struct tcphdr *)(ip6 + 1);
14793 			rack->r_ctl.fsb.udp = NULL;
14794 		}
14795 		tcpip_fillheaders(rack->rc_inp,
14796 				  tp->t_port,
14797 				  ip6, rack->r_ctl.fsb.th);
14798 		rack->r_ctl.fsb.hoplimit = in6_selecthlim(rack->rc_inp, NULL);
14799 	} else
14800 #endif				/* INET6 */
14801 #ifdef INET
14802 	{
14803 		rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct tcpiphdr);
14804 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
14805 		if (tp->t_port) {
14806 			rack->r_ctl.fsb.tcp_ip_hdr_len += sizeof(struct udphdr);
14807 			udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
14808 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
14809 			udp->uh_dport = tp->t_port;
14810 			rack->r_ctl.fsb.udp = udp;
14811 			rack->r_ctl.fsb.th = (struct tcphdr *)(udp + 1);
14812 		} else
14813 		{
14814 			rack->r_ctl.fsb.udp = NULL;
14815 			rack->r_ctl.fsb.th = (struct tcphdr *)(ip + 1);
14816 		}
14817 		tcpip_fillheaders(rack->rc_inp,
14818 				  tp->t_port,
14819 				  ip, rack->r_ctl.fsb.th);
14820 		rack->r_ctl.fsb.hoplimit = tptoinpcb(tp)->inp_ip_ttl;
14821 	}
14822 #endif
14823 	rack->r_ctl.fsb.recwin = lmin(lmax(sbspace(&tptosocket(tp)->so_rcv), 0),
14824 	    (long)TCP_MAXWIN << tp->rcv_scale);
14825 	rack->r_fsb_inited = 1;
14826 }
14827 
14828 static int
rack_init_fsb(struct tcpcb * tp,struct tcp_rack * rack)14829 rack_init_fsb(struct tcpcb *tp, struct tcp_rack *rack)
14830 {
14831 	/*
14832 	 * Allocate the larger of spaces V6 if available else just
14833 	 * V4 and include udphdr (overbook)
14834 	 */
14835 #ifdef INET6
14836 	rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + sizeof(struct udphdr);
14837 #else
14838 	rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct tcpiphdr) + sizeof(struct udphdr);
14839 #endif
14840 	rack->r_ctl.fsb.tcp_ip_hdr = malloc(rack->r_ctl.fsb.tcp_ip_hdr_len,
14841 					    M_TCPFSB, M_NOWAIT|M_ZERO);
14842 	if (rack->r_ctl.fsb.tcp_ip_hdr == NULL) {
14843 		return (ENOMEM);
14844 	}
14845 	rack->r_fsb_inited = 0;
14846 	return (0);
14847 }
14848 
14849 static void
rack_log_hystart_event(struct tcp_rack * rack,uint32_t high_seq,uint8_t mod)14850 rack_log_hystart_event(struct tcp_rack *rack, uint32_t high_seq, uint8_t mod)
14851 {
14852 	/*
14853 	 * Types of logs (mod value)
14854 	 * 20 - Initial round setup
14855 	 * 21 - Rack declares a new round.
14856 	 */
14857 	struct tcpcb *tp;
14858 
14859 	tp = rack->rc_tp;
14860 	if (tcp_bblogging_on(tp)) {
14861 		union tcp_log_stackspecific log;
14862 		struct timeval tv;
14863 
14864 		memset(&log, 0, sizeof(log));
14865 		log.u_bbr.flex1 = rack->r_ctl.current_round;
14866 		log.u_bbr.flex2 = rack->r_ctl.roundends;
14867 		log.u_bbr.flex3 = high_seq;
14868 		log.u_bbr.flex4 = tp->snd_max;
14869 		log.u_bbr.flex8 = mod;
14870 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
14871 		log.u_bbr.cur_del_rate = rack->rc_tp->t_sndbytes;
14872 		log.u_bbr.delRate = rack->rc_tp->t_snd_rxt_bytes;
14873 		TCP_LOG_EVENTP(tp, NULL,
14874 		    &tptosocket(tp)->so_rcv,
14875 		    &tptosocket(tp)->so_snd,
14876 		    TCP_HYSTART, 0,
14877 		    0, &log, false, &tv);
14878 	}
14879 }
14880 
14881 static void
rack_deferred_init(struct tcpcb * tp,struct tcp_rack * rack)14882 rack_deferred_init(struct tcpcb *tp, struct tcp_rack *rack)
14883 {
14884 	rack->rack_deferred_inited = 1;
14885 	rack->r_ctl.roundends = tp->snd_max;
14886 	rack->r_ctl.rc_high_rwnd = tp->snd_wnd;
14887 	rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
14888 }
14889 
14890 static void
rack_init_retransmit_value(struct tcp_rack * rack,int ctl)14891 rack_init_retransmit_value(struct tcp_rack *rack, int ctl)
14892 {
14893 	/* Retransmit bit controls.
14894 	 *
14895 	 * The setting of these values control one of
14896 	 * three settings you can have and dictate
14897 	 * how rack does retransmissions. Note this
14898 	 * is in *any* mode i.e. pacing on or off DGP
14899 	 * fixed rate pacing, or just bursting rack.
14900 	 *
14901 	 * 1 - Use full sized retransmits i.e. limit
14902 	 *     the size to whatever the pace_max_segments
14903 	 *     size is.
14904 	 *
14905 	 * 2 - Use pacer min granularity as a guide to
14906 	 *     the size combined with the current calculated
14907 	 *     goodput b/w measurement. So for example if
14908 	 *     the goodput is measured at 20Mbps we would
14909 	 *     calculate 8125 (pacer minimum 250usec in
14910 	 *     that b/w) and then round it up to the next
14911 	 *     MSS i.e. for 1448 mss 6 MSS or 8688 bytes.
14912 	 *
14913 	 * 0 - The rack default 1 MSS (anything not 0/1/2
14914 	 *     fall here too if we are setting via rack_init()).
14915 	 *
14916 	 */
14917 	if (ctl == 1) {
14918 		rack->full_size_rxt = 1;
14919 		rack->shape_rxt_to_pacing_min  = 0;
14920 	} else if (ctl == 2) {
14921 		rack->full_size_rxt = 0;
14922 		rack->shape_rxt_to_pacing_min  = 1;
14923 	} else {
14924 		rack->full_size_rxt = 0;
14925 		rack->shape_rxt_to_pacing_min  = 0;
14926 	}
14927 }
14928 
14929 static void
rack_log_chg_info(struct tcpcb * tp,struct tcp_rack * rack,uint8_t mod,uint32_t flex1,uint32_t flex2,uint32_t flex3)14930 rack_log_chg_info(struct tcpcb *tp, struct tcp_rack *rack, uint8_t mod,
14931 		  uint32_t flex1,
14932 		  uint32_t flex2,
14933 		  uint32_t flex3)
14934 {
14935 	if (tcp_bblogging_on(rack->rc_tp)) {
14936 		union tcp_log_stackspecific log;
14937 		struct timeval tv;
14938 
14939 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
14940 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
14941 		log.u_bbr.flex8 = mod;
14942 		log.u_bbr.flex1 = flex1;
14943 		log.u_bbr.flex2 = flex2;
14944 		log.u_bbr.flex3 = flex3;
14945 		tcp_log_event(tp, NULL, NULL, NULL, TCP_CHG_QUERY, 0,
14946 			       0, &log, false, NULL, __func__, __LINE__, &tv);
14947 	}
14948 }
14949 
14950 static int
rack_chg_query(struct tcpcb * tp,struct tcp_query_resp * reqr)14951 rack_chg_query(struct tcpcb *tp, struct tcp_query_resp *reqr)
14952 {
14953 	struct tcp_rack *rack;
14954 	struct rack_sendmap *rsm;
14955 	int i;
14956 
14957 
14958 	rack = (struct tcp_rack *)tp->t_fb_ptr;
14959 	switch (reqr->req) {
14960 	case TCP_QUERY_SENDMAP:
14961 		if ((reqr->req_param == tp->snd_max) ||
14962 		    (tp->snd_max == tp->snd_una)){
14963 			/* Unlikely */
14964 			return (0);
14965 		}
14966 		rsm = tqhash_find(rack->r_ctl.tqh, reqr->req_param);
14967 		if (rsm == NULL) {
14968 			/* Can't find that seq -- unlikely */
14969 			return (0);
14970 		}
14971 		reqr->sendmap_start = rsm->r_start;
14972 		reqr->sendmap_end = rsm->r_end;
14973 		reqr->sendmap_send_cnt = rsm->r_rtr_cnt;
14974 		reqr->sendmap_fas = rsm->r_fas;
14975 		if (reqr->sendmap_send_cnt > SNDMAP_NRTX)
14976 			reqr->sendmap_send_cnt = SNDMAP_NRTX;
14977 		for(i=0; i<reqr->sendmap_send_cnt; i++)
14978 			reqr->sendmap_time[i] = rsm->r_tim_lastsent[i];
14979 		reqr->sendmap_ack_arrival = rsm->r_ack_arrival;
14980 		reqr->sendmap_flags = rsm->r_flags & SNDMAP_MASK;
14981 		reqr->sendmap_r_rtr_bytes = rsm->r_rtr_bytes;
14982 		reqr->sendmap_dupacks = rsm->r_dupack;
14983 		rack_log_chg_info(tp, rack, 1,
14984 				  rsm->r_start,
14985 				  rsm->r_end,
14986 				  rsm->r_flags);
14987 		return(1);
14988 		break;
14989 	case TCP_QUERY_TIMERS_UP:
14990 		if (rack->r_ctl.rc_hpts_flags == 0) {
14991 			/* no timers up */
14992 			return (0);
14993 		}
14994 		reqr->timer_hpts_flags = rack->r_ctl.rc_hpts_flags;
14995 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
14996 			reqr->timer_pacing_to = rack->r_ctl.rc_last_output_to;
14997 		}
14998 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
14999 			reqr->timer_timer_exp = rack->r_ctl.rc_timer_exp;
15000 		}
15001 		rack_log_chg_info(tp, rack, 2,
15002 				  rack->r_ctl.rc_hpts_flags,
15003 				  rack->r_ctl.rc_last_output_to,
15004 				  rack->r_ctl.rc_timer_exp);
15005 		return (1);
15006 		break;
15007 	case TCP_QUERY_RACK_TIMES:
15008 		/* Reordering items */
15009 		reqr->rack_num_dsacks = rack->r_ctl.num_dsack;
15010 		reqr->rack_reorder_ts = rack->r_ctl.rc_reorder_ts;
15011 		/* Timerstamps and timers */
15012 		reqr->rack_rxt_last_time = rack->r_ctl.rc_tlp_rxt_last_time;
15013 		reqr->rack_min_rtt = rack->r_ctl.rc_rack_min_rtt;
15014 		reqr->rack_rtt = rack->rc_rack_rtt;
15015 		reqr->rack_tmit_time = rack->r_ctl.rc_rack_tmit_time;
15016 		reqr->rack_srtt_measured = rack->rc_srtt_measure_made;
15017 		/* PRR data */
15018 		reqr->rack_sacked = rack->r_ctl.rc_sacked;
15019 		reqr->rack_holes_rxt = rack->r_ctl.rc_holes_rxt;
15020 		reqr->rack_prr_delivered = rack->r_ctl.rc_prr_delivered;
15021 		reqr->rack_prr_recovery_fs = rack->r_ctl.rc_prr_recovery_fs;
15022 		reqr->rack_prr_sndcnt = rack->r_ctl.rc_prr_sndcnt;
15023 		reqr->rack_prr_out = rack->r_ctl.rc_prr_out;
15024 		/* TLP and persists info */
15025 		reqr->rack_tlp_out = rack->rc_tlp_in_progress;
15026 		reqr->rack_tlp_cnt_out = rack->r_ctl.rc_tlp_cnt_out;
15027 		if (rack->rc_in_persist) {
15028 			reqr->rack_time_went_idle = rack->r_ctl.rc_went_idle_time;
15029 			reqr->rack_in_persist = 1;
15030 		} else {
15031 			reqr->rack_time_went_idle = 0;
15032 			reqr->rack_in_persist = 0;
15033 		}
15034 		if (rack->r_wanted_output)
15035 			reqr->rack_wanted_output = 1;
15036 		else
15037 			reqr->rack_wanted_output = 0;
15038 		return (1);
15039 		break;
15040 	default:
15041 		return (-EINVAL);
15042 	}
15043 }
15044 
15045 static void
rack_switch_failed(struct tcpcb * tp)15046 rack_switch_failed(struct tcpcb *tp)
15047 {
15048 	/*
15049 	 * This method gets called if a stack switch was
15050 	 * attempted and it failed. We are left
15051 	 * but our hpts timers were stopped and we
15052 	 * need to validate time units and t_flags2.
15053 	 */
15054 	struct tcp_rack *rack;
15055 	struct timeval tv;
15056 	uint32_t cts;
15057 	uint32_t toval;
15058 	struct hpts_diag diag;
15059 
15060 	rack = (struct tcp_rack *)tp->t_fb_ptr;
15061 	tcp_change_time_units(tp, TCP_TMR_GRANULARITY_USEC);
15062 	if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
15063 		tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
15064 	else
15065 		tp->t_flags2 &= ~TF2_SUPPORTS_MBUFQ;
15066 	if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
15067 		tp->t_flags2 |= TF2_MBUF_ACKCMP;
15068 	if (tp->t_in_hpts > IHPTS_NONE) {
15069 		/* Strange */
15070 		return;
15071 	}
15072 	cts = tcp_get_usecs(&tv);
15073 	if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
15074 		if (TSTMP_GT(rack->r_ctl.rc_last_output_to, cts)) {
15075 			toval = rack->r_ctl.rc_last_output_to - cts;
15076 		} else {
15077 			/* one slot please */
15078 			toval = HPTS_TICKS_PER_SLOT;
15079 		}
15080 	} else if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
15081 		if (TSTMP_GT(rack->r_ctl.rc_timer_exp, cts)) {
15082 			toval = rack->r_ctl.rc_timer_exp - cts;
15083 		} else {
15084 			/* one slot please */
15085 			toval = HPTS_TICKS_PER_SLOT;
15086 		}
15087 	} else
15088 		toval = HPTS_TICKS_PER_SLOT;
15089 	(void)tcp_hpts_insert_diag(tp, HPTS_USEC_TO_SLOTS(toval),
15090 				   __LINE__, &diag);
15091 	rack_log_hpts_diag(rack, cts, &diag, &tv);
15092 }
15093 
15094 static int
rack_init_outstanding(struct tcpcb * tp,struct tcp_rack * rack,uint32_t us_cts,void * ptr)15095 rack_init_outstanding(struct tcpcb *tp, struct tcp_rack *rack, uint32_t us_cts, void *ptr)
15096 {
15097 	struct rack_sendmap *rsm, *ersm;
15098 	int insret __diagused;
15099 	/*
15100 	 * When initing outstanding, we must be quite careful
15101 	 * to not refer to tp->t_fb_ptr. This has the old rack
15102 	 * pointer in it, not the "new" one (when we are doing
15103 	 * a stack switch).
15104 	 */
15105 
15106 
15107 	if (tp->t_fb->tfb_chg_query == NULL) {
15108 		/* Create a send map for the current outstanding data */
15109 
15110 		rsm = rack_alloc(rack);
15111 		if (rsm == NULL) {
15112 			uma_zfree(rack_pcb_zone, ptr);
15113 			return (ENOMEM);
15114 		}
15115 		rsm->r_no_rtt_allowed = 1;
15116 		rsm->r_tim_lastsent[0] = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
15117 		rsm->r_rtr_cnt = 1;
15118 		rsm->r_rtr_bytes = 0;
15119 		if (tp->t_flags & TF_SENTFIN)
15120 			rsm->r_flags |= RACK_HAS_FIN;
15121 		rsm->r_end = tp->snd_max;
15122 		if (tp->snd_una == tp->iss) {
15123 			/* The data space is one beyond snd_una */
15124 			rsm->r_flags |= RACK_HAS_SYN;
15125 			rsm->r_start = tp->iss;
15126 			rsm->r_end = rsm->r_start + (tp->snd_max - tp->snd_una);
15127 		} else
15128 			rsm->r_start = tp->snd_una;
15129 		rsm->r_dupack = 0;
15130 		if (rack->rc_inp->inp_socket->so_snd.sb_mb != NULL) {
15131 			rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd, 0, &rsm->soff);
15132 			if (rsm->m) {
15133 				rsm->orig_m_len = rsm->m->m_len;
15134 				rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
15135 			} else {
15136 				rsm->orig_m_len = 0;
15137 				rsm->orig_t_space = 0;
15138 			}
15139 		} else {
15140 			/*
15141 			 * This can happen if we have a stand-alone FIN or
15142 			 *  SYN.
15143 			 */
15144 			rsm->m = NULL;
15145 			rsm->orig_m_len = 0;
15146 			rsm->orig_t_space = 0;
15147 			rsm->soff = 0;
15148 		}
15149 #ifdef INVARIANTS
15150 		if ((insret = tqhash_insert(rack->r_ctl.tqh, rsm)) != 0) {
15151 			panic("Insert in tailq_hash fails ret:%d rack:%p rsm:%p",
15152 			      insret, rack, rsm);
15153 		}
15154 #else
15155 		(void)tqhash_insert(rack->r_ctl.tqh, rsm);
15156 #endif
15157 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
15158 		rsm->r_in_tmap = 1;
15159 	} else {
15160 		/* We have a query mechanism, lets use it */
15161 		struct tcp_query_resp qr;
15162 		int i;
15163 		tcp_seq at;
15164 
15165 		at = tp->snd_una;
15166 		while (at != tp->snd_max) {
15167 			memset(&qr, 0, sizeof(qr));
15168 			qr.req = TCP_QUERY_SENDMAP;
15169 			qr.req_param = at;
15170 			if ((*tp->t_fb->tfb_chg_query)(tp, &qr) == 0)
15171 				break;
15172 			/* Move forward */
15173 			at = qr.sendmap_end;
15174 			/* Now lets build the entry for this one */
15175 			rsm = rack_alloc(rack);
15176 			if (rsm == NULL) {
15177 				uma_zfree(rack_pcb_zone, ptr);
15178 				return (ENOMEM);
15179 			}
15180 			memset(rsm, 0, sizeof(struct rack_sendmap));
15181 			/* Now configure the rsm and insert it */
15182 			rsm->r_dupack = qr.sendmap_dupacks;
15183 			rsm->r_start = qr.sendmap_start;
15184 			rsm->r_end = qr.sendmap_end;
15185 			if (qr.sendmap_fas)
15186 				rsm->r_fas = qr.sendmap_end;
15187 			else
15188 				rsm->r_fas = rsm->r_start - tp->snd_una;
15189 			/*
15190 			 * We have carefully aligned the bits
15191 			 * so that all we have to do is copy over
15192 			 * the bits with the mask.
15193 			 */
15194 			rsm->r_flags = qr.sendmap_flags & SNDMAP_MASK;
15195 			rsm->r_rtr_bytes = qr.sendmap_r_rtr_bytes;
15196 			rsm->r_rtr_cnt = qr.sendmap_send_cnt;
15197 			rsm->r_ack_arrival = qr.sendmap_ack_arrival;
15198 			for (i=0 ; i<rsm->r_rtr_cnt; i++)
15199 				rsm->r_tim_lastsent[i]	= qr.sendmap_time[i];
15200 			rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd,
15201 					   (rsm->r_start - tp->snd_una), &rsm->soff);
15202 			if (rsm->m) {
15203 				rsm->orig_m_len = rsm->m->m_len;
15204 				rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
15205 			} else {
15206 				rsm->orig_m_len = 0;
15207 				rsm->orig_t_space = 0;
15208 			}
15209 #ifdef INVARIANTS
15210 			if ((insret = tqhash_insert(rack->r_ctl.tqh, rsm)) != 0) {
15211 				panic("Insert in tailq_hash fails ret:%d rack:%p rsm:%p",
15212 				      insret, rack, rsm);
15213 			}
15214 #else
15215 			(void)tqhash_insert(rack->r_ctl.tqh, rsm);
15216 #endif
15217 			if ((rsm->r_flags & RACK_ACKED) == 0)  {
15218 				TAILQ_FOREACH(ersm, &rack->r_ctl.rc_tmap, r_tnext) {
15219 					if (ersm->r_tim_lastsent[(ersm->r_rtr_cnt-1)] >
15220 					    rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]) {
15221 						/*
15222 						 * If the existing ersm was sent at
15223 						 * a later time than the new one, then
15224 						 * the new one should appear ahead of this
15225 						 * ersm.
15226 						 */
15227 						rsm->r_in_tmap = 1;
15228 						TAILQ_INSERT_BEFORE(ersm, rsm, r_tnext);
15229 						break;
15230 					}
15231 				}
15232 				if (rsm->r_in_tmap == 0) {
15233 					/*
15234 					 * Not found so shove it on the tail.
15235 					 */
15236 					TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
15237 					rsm->r_in_tmap = 1;
15238 				}
15239  			} else {
15240 				if ((rack->r_ctl.rc_sacklast == NULL) ||
15241 				    (SEQ_GT(rsm->r_end, rack->r_ctl.rc_sacklast->r_end))) {
15242 					rack->r_ctl.rc_sacklast = rsm;
15243 				}
15244 			}
15245 			rack_log_chg_info(tp, rack, 3,
15246 					  rsm->r_start,
15247 					  rsm->r_end,
15248 					  rsm->r_flags);
15249 		}
15250 	}
15251 	return (0);
15252 }
15253 
15254 static void
rack_translate_policer_detect(struct tcp_rack * rack,uint32_t optval)15255 rack_translate_policer_detect(struct tcp_rack *rack, uint32_t optval)
15256 {
15257 	/*
15258 	 * P = Percent of retransmits 499 = 49.9%
15259 	 * A = Average number 1 (.1%) -> 169 (16.9%)
15260 	 * M = Median number of retrans 1 - 16
15261 	 * MMMM MMMM AAAA AAAA PPPP PPPP PPPP PPPP
15262 	 *
15263 	 */
15264 	uint16_t per, upp;
15265 
15266 	per = optval & 0x0000ffff;
15267 	rack->r_ctl.policer_rxt_threshold = (uint32_t)(per & 0xffff);
15268 	upp = ((optval & 0xffff0000) >> 16);
15269 	rack->r_ctl.policer_avg_threshold = (0x00ff & upp);
15270 	rack->r_ctl.policer_med_threshold = ((upp >> 8) & 0x00ff);
15271 	if ((rack->r_ctl.policer_rxt_threshold > 0) &&
15272 	    (rack->r_ctl.policer_avg_threshold > 0) &&
15273 	    (rack->r_ctl.policer_med_threshold > 0)) {
15274 		rack->policer_detect_on = 1;
15275 	} else {
15276 		rack->policer_detect_on = 0;
15277 	}
15278 	rack->r_ctl.saved_policer_val = optval;
15279 	policer_detection_log(rack, optval,
15280 			      rack->r_ctl.policer_avg_threshold,
15281 			      rack->r_ctl.policer_med_threshold,
15282 			      rack->r_ctl.policer_rxt_threshold, 11);
15283 }
15284 
15285 static int32_t
rack_init(struct tcpcb * tp,void ** ptr)15286 rack_init(struct tcpcb *tp, void **ptr)
15287 {
15288 	struct inpcb *inp = tptoinpcb(tp);
15289 	struct tcp_rack *rack = NULL;
15290 	uint32_t iwin, snt, us_cts;
15291 	size_t sz;
15292 	int err, no_query;
15293 
15294 	tcp_hpts_init(tp);
15295 
15296 	/*
15297 	 * First are we the initial or are we a switched stack?
15298 	 * If we are initing via tcp_newtcppcb the ptr passed
15299 	 * will be tp->t_fb_ptr. If its a stack switch that
15300 	 * has a previous stack we can query it will be a local
15301 	 * var that will in the end be set into t_fb_ptr.
15302 	 */
15303 	if (ptr == &tp->t_fb_ptr)
15304 		no_query = 1;
15305 	else
15306 		no_query = 0;
15307 	*ptr = uma_zalloc(rack_pcb_zone, M_NOWAIT);
15308 	if (*ptr == NULL) {
15309 		/*
15310 		 * We need to allocate memory but cant. The INP and INP_INFO
15311 		 * locks and they are recursive (happens during setup. So a
15312 		 * scheme to drop the locks fails :(
15313 		 *
15314 		 */
15315 		return(ENOMEM);
15316 	}
15317 	memset(*ptr, 0, sizeof(struct tcp_rack));
15318 	rack = (struct tcp_rack *)*ptr;
15319 	rack->r_ctl.tqh = malloc(sizeof(struct tailq_hash), M_TCPFSB, M_NOWAIT);
15320 	if (rack->r_ctl.tqh == NULL) {
15321 		uma_zfree(rack_pcb_zone, rack);
15322 		return(ENOMEM);
15323 	}
15324 	tqhash_init(rack->r_ctl.tqh);
15325 	TAILQ_INIT(&rack->r_ctl.rc_free);
15326 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
15327 	rack->rc_tp = tp;
15328 	rack->rc_inp = inp;
15329 	/* Set the flag */
15330 	rack->r_is_v6 = (inp->inp_vflag & INP_IPV6) != 0;
15331 	/* Probably not needed but lets be sure */
15332 	rack_clear_rate_sample(rack);
15333 	/*
15334 	 * Save off the default values, socket options will poke
15335 	 * at these if pacing is not on or we have not yet
15336 	 * reached where pacing is on (gp_ready/fixed enabled).
15337 	 * When they get set into the CC module (when gp_ready
15338 	 * is enabled or we enable fixed) then we will set these
15339 	 * values into the CC and place in here the old values
15340 	 * so we have a restoral. Then we will set the flag
15341 	 * rc_pacing_cc_set. That way whenever we turn off pacing
15342 	 * or switch off this stack, we will know to go restore
15343 	 * the saved values.
15344 	 *
15345 	 * We specifically put into the beta the ecn value for pacing.
15346 	 */
15347 	rack->rc_new_rnd_needed = 1;
15348 	rack->r_ctl.rc_split_limit = V_tcp_map_split_limit;
15349 	/* We want abe like behavior as well */
15350 
15351 	rack->r_ctl.rc_saved_beta.newreno_flags |= CC_NEWRENO_BETA_ECN_ENABLED;
15352 	rack->r_ctl.rc_reorder_fade = rack_reorder_fade;
15353 	rack->rc_allow_data_af_clo = rack_ignore_data_after_close;
15354 	rack->r_ctl.rc_tlp_threshold = rack_tlp_thresh;
15355 	rack->r_ctl.policer_del_mss = rack_req_del_mss;
15356 	if ((rack_policer_rxt_thresh > 0) &&
15357 	    (rack_policer_avg_thresh > 0) &&
15358 	    (rack_policer_med_thresh > 0)) {
15359 		rack->r_ctl.policer_rxt_threshold = rack_policer_rxt_thresh;
15360 		rack->r_ctl.policer_avg_threshold = rack_policer_avg_thresh;
15361 		rack->r_ctl.policer_med_threshold = rack_policer_med_thresh;
15362 		rack->policer_detect_on = 1;
15363 	} else {
15364 		rack->policer_detect_on = 0;
15365 	}
15366 	if (rack_fill_cw_state)
15367 		rack->rc_pace_to_cwnd = 1;
15368 	if (rack_pacing_min_seg)
15369 		rack->r_ctl.rc_user_set_min_segs = rack_pacing_min_seg;
15370 	if (use_rack_rr)
15371 		rack->use_rack_rr = 1;
15372 	if (rack_dnd_default) {
15373 		rack->rc_pace_dnd = 1;
15374 	}
15375 	if (V_tcp_delack_enabled)
15376 		tp->t_delayed_ack = 1;
15377 	else
15378 		tp->t_delayed_ack = 0;
15379 #ifdef TCP_ACCOUNTING
15380 	if (rack_tcp_accounting) {
15381 		tp->t_flags2 |= TF2_TCP_ACCOUNTING;
15382 	}
15383 #endif
15384 	rack->r_ctl.pcm_i.cnt_alloc = RACK_DEFAULT_PCM_ARRAY;
15385 	sz = (sizeof(struct rack_pcm_stats) * rack->r_ctl.pcm_i.cnt_alloc);
15386 	rack->r_ctl.pcm_s = malloc(sz,M_TCPPCM, M_NOWAIT);
15387 	if (rack->r_ctl.pcm_s == NULL) {
15388 		rack->r_ctl.pcm_i.cnt_alloc = 0;
15389 	}
15390 #ifdef NETFLIX_STATS
15391 	rack->r_ctl.side_chan_dis_mask = tcp_sidechannel_disable_mask;
15392 #endif
15393 	rack->r_ctl.rack_per_upper_bound_ss = (uint8_t)rack_per_upper_bound_ss;
15394 	rack->r_ctl.rack_per_upper_bound_ca = (uint8_t)rack_per_upper_bound_ca;
15395 	if (rack_enable_shared_cwnd)
15396 		rack->rack_enable_scwnd = 1;
15397 	rack->r_ctl.pace_len_divisor = rack_default_pacing_divisor;
15398 	rack->rc_user_set_max_segs = rack_hptsi_segments;
15399 	rack->r_ctl.max_reduction = rack_max_reduce;
15400 	rack->rc_force_max_seg = 0;
15401 	TAILQ_INIT(&rack->r_ctl.opt_list);
15402 	rack->r_ctl.rc_saved_beta.beta = V_newreno_beta_ecn;
15403 	rack->r_ctl.rc_saved_beta.beta_ecn = V_newreno_beta_ecn;
15404 	if (rack_hibeta_setting) {
15405 		rack->rack_hibeta = 1;
15406 		if ((rack_hibeta_setting >= 50) &&
15407 		    (rack_hibeta_setting <= 100)) {
15408 			rack->r_ctl.rc_saved_beta.beta = rack_hibeta_setting;
15409 			rack->r_ctl.saved_hibeta = rack_hibeta_setting;
15410 		}
15411 	} else {
15412 		rack->r_ctl.saved_hibeta = 50;
15413 	}
15414 	/*
15415 	 * We initialize to all ones so we never match 0
15416 	 * just in case the client sends in 0, it hopefully
15417 	 * will never have all 1's in ms :-)
15418 	 */
15419 	rack->r_ctl.last_tm_mark = 0xffffffffffffffff;
15420 	rack->r_ctl.rc_reorder_shift = rack_reorder_thresh;
15421 	rack->r_ctl.rc_pkt_delay = rack_pkt_delay;
15422 	rack->r_ctl.pol_bw_comp = rack_policing_do_bw_comp;
15423 	rack->r_ctl.rc_tlp_cwnd_reduce = rack_lower_cwnd_at_tlp;
15424 	rack->r_ctl.rc_lowest_us_rtt = 0xffffffff;
15425 	rack->r_ctl.rc_highest_us_rtt = 0;
15426 	rack->r_ctl.bw_rate_cap = rack_bw_rate_cap;
15427 	rack->pcm_enabled = rack_pcm_is_enabled;
15428 	if (rack_fillcw_bw_cap)
15429 		rack->r_ctl.fillcw_cap = rack_fillcw_bw_cap;
15430 	rack->r_ctl.timer_slop = TICKS_2_USEC(tcp_rexmit_slop);
15431 	if (rack_use_cmp_acks)
15432 		rack->r_use_cmp_ack = 1;
15433 	if (rack_disable_prr)
15434 		rack->rack_no_prr = 1;
15435 	if (rack_gp_no_rec_chg)
15436 		rack->rc_gp_no_rec_chg = 1;
15437 	if (rack_pace_every_seg && tcp_can_enable_pacing()) {
15438 		rack->r_ctl.pacing_method |= RACK_REG_PACING;
15439 		rack->rc_always_pace = 1;
15440 		if (rack->rack_hibeta)
15441 			rack_set_cc_pacing(rack);
15442 	} else
15443 		rack->rc_always_pace = 0;
15444 	if (rack_enable_mqueue_for_nonpaced || rack->r_use_cmp_ack)
15445 		rack->r_mbuf_queue = 1;
15446 	else
15447 		rack->r_mbuf_queue = 0;
15448 	rack_set_pace_segments(tp, rack, __LINE__, NULL);
15449 	if (rack_limits_scwnd)
15450 		rack->r_limit_scw = 1;
15451 	else
15452 		rack->r_limit_scw = 0;
15453 	rack_init_retransmit_value(rack, rack_rxt_controls);
15454 	rack->rc_labc = V_tcp_abc_l_var;
15455 	if (rack_honors_hpts_min_to)
15456 		rack->r_use_hpts_min = 1;
15457 	if (tp->snd_una != 0) {
15458 		rack->r_ctl.idle_snd_una = tp->snd_una;
15459 		rack->rc_sendvars_notset = 0;
15460 		/*
15461 		 * Make sure any TCP timers are not running.
15462 		 */
15463 		tcp_timer_stop(tp);
15464 	} else {
15465 		/*
15466 		 * Server side, we are called from the
15467 		 * syn-cache. This means none of the
15468 		 * snd_una/max are set yet so we have
15469 		 * to defer this until the first send.
15470 		 */
15471 		rack->rc_sendvars_notset = 1;
15472 	}
15473 
15474 	rack->r_ctl.rc_rate_sample_method = rack_rate_sample_method;
15475 	rack->rack_tlp_threshold_use = rack_tlp_threshold_use;
15476 	rack->r_ctl.rc_prr_sendalot = rack_send_a_lot_in_prr;
15477 	rack->r_ctl.rc_min_to = rack_min_to;
15478 	microuptime(&rack->r_ctl.act_rcv_time);
15479 	rack->r_ctl.rc_last_time_decay = rack->r_ctl.act_rcv_time;
15480 	rack->r_ctl.rack_per_of_gp_ss = rack_per_of_gp_ss;
15481 	if (rack_hw_up_only)
15482 		rack->r_up_only = 1;
15483 	if (rack_do_dyn_mul) {
15484 		/* When dynamic adjustment is on CA needs to start at 100% */
15485 		rack->rc_gp_dyn_mul = 1;
15486 		if (rack_do_dyn_mul >= 100)
15487 			rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
15488 	} else
15489 		rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
15490 	rack->r_ctl.rack_per_of_gp_rec = rack_per_of_gp_rec;
15491 	if (rack_timely_off) {
15492 		rack->rc_skip_timely = 1;
15493 	}
15494 	if (rack->rc_skip_timely) {
15495 		rack->r_ctl.rack_per_of_gp_rec = 90;
15496 		rack->r_ctl.rack_per_of_gp_ca = 100;
15497 		rack->r_ctl.rack_per_of_gp_ss = 250;
15498 	}
15499 	rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
15500 	rack->r_ctl.rc_tlp_rxt_last_time = tcp_tv_to_mssectick(&rack->r_ctl.act_rcv_time);
15501 	rack->r_ctl.last_rcv_tstmp_for_rtt = tcp_tv_to_mssectick(&rack->r_ctl.act_rcv_time);
15502 
15503 	setup_time_filter_small(&rack->r_ctl.rc_gp_min_rtt, FILTER_TYPE_MIN,
15504 				rack_probertt_filter_life);
15505 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
15506 	rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
15507 	rack->r_ctl.rc_time_of_last_probertt = us_cts;
15508 	rack->r_ctl.rc_went_idle_time = us_cts;
15509 	rack->r_ctl.challenge_ack_ts = tcp_ts_getticks() - (tcp_ack_war_time_window + 1);
15510 	rack->r_ctl.rc_time_probertt_starts = 0;
15511 
15512 	rack->r_ctl.gp_rnd_thresh = rack_rnd_cnt_req & 0xff;
15513 	if (rack_rnd_cnt_req  & 0x10000)
15514 		rack->r_ctl.gate_to_fs = 1;
15515 	rack->r_ctl.gp_gain_req = rack_gp_gain_req;
15516 	if ((rack_rnd_cnt_req & 0x100) > 0) {
15517 
15518 	}
15519 	if (rack_dsack_std_based & 0x1) {
15520 		/* Basically this means all rack timers are at least (srtt + 1/4 srtt) */
15521 		rack->rc_rack_tmr_std_based = 1;
15522 	}
15523 	if (rack_dsack_std_based & 0x2) {
15524 		/* Basically this means  rack timers are extended based on dsack by up to (2 * srtt) */
15525 		rack->rc_rack_use_dsack = 1;
15526 	}
15527 	/* We require at least one measurement, even if the sysctl is 0 */
15528 	if (rack_req_measurements)
15529 		rack->r_ctl.req_measurements = rack_req_measurements;
15530 	else
15531 		rack->r_ctl.req_measurements = 1;
15532 	if (rack_enable_hw_pacing)
15533 		rack->rack_hdw_pace_ena = 1;
15534 	if (rack_hw_rate_caps)
15535 		rack->r_rack_hw_rate_caps = 1;
15536 	if (rack_non_rxt_use_cr)
15537 		rack->rack_rec_nonrxt_use_cr = 1;
15538 	/* Lets setup the fsb block */
15539 	err = rack_init_fsb(tp, rack);
15540 	if (err) {
15541 		uma_zfree(rack_pcb_zone, *ptr);
15542 		*ptr = NULL;
15543 		return (err);
15544 	}
15545 	if (rack_do_hystart) {
15546 		tp->t_ccv.flags |= CCF_HYSTART_ALLOWED;
15547 		if (rack_do_hystart > 1)
15548 			tp->t_ccv.flags |= CCF_HYSTART_CAN_SH_CWND;
15549 		if (rack_do_hystart > 2)
15550 			tp->t_ccv.flags |= CCF_HYSTART_CONS_SSTH;
15551 	}
15552 	/* Log what we will do with queries */
15553 	rack_log_chg_info(tp, rack, 7,
15554 			  no_query, 0, 0);
15555 	if (rack_def_profile)
15556 		rack_set_profile(rack, rack_def_profile);
15557 	/* Cancel the GP measurement in progress */
15558 	tp->t_flags &= ~TF_GPUTINPROG;
15559 	if ((tp->t_state != TCPS_CLOSED) &&
15560 	    (tp->t_state != TCPS_TIME_WAIT)) {
15561 		/*
15562 		 * We are already open, we may
15563 		 * need to adjust a few things.
15564 		 */
15565 		if (SEQ_GT(tp->snd_max, tp->iss))
15566 			snt = tp->snd_max - tp->iss;
15567 		else
15568 			snt = 0;
15569 		iwin = rc_init_window(rack);
15570 		if ((snt < iwin) &&
15571 		    (no_query == 1)) {
15572 			/* We are not past the initial window
15573 			 * on the first init (i.e. a stack switch
15574 			 * has not yet occured) so we need to make
15575 			 * sure cwnd and ssthresh is correct.
15576 			 */
15577 			if (tp->snd_cwnd < iwin)
15578 				tp->snd_cwnd = iwin;
15579 			/*
15580 			 * If we are within the initial window
15581 			 * we want ssthresh to be unlimited. Setting
15582 			 * it to the rwnd (which the default stack does
15583 			 * and older racks) is not really a good idea
15584 			 * since we want to be in SS and grow both the
15585 			 * cwnd and the rwnd (via dynamic rwnd growth). If
15586 			 * we set it to the rwnd then as the peer grows its
15587 			 * rwnd we will be stuck in CA and never hit SS.
15588 			 *
15589 			 * Its far better to raise it up high (this takes the
15590 			 * risk that there as been a loss already, probably
15591 			 * we should have an indicator in all stacks of loss
15592 			 * but we don't), but considering the normal use this
15593 			 * is a risk worth taking. The consequences of not
15594 			 * hitting SS are far worse than going one more time
15595 			 * into it early on (before we have sent even a IW).
15596 			 * It is highly unlikely that we will have had a loss
15597 			 * before getting the IW out.
15598 			 */
15599 			tp->snd_ssthresh = 0xffffffff;
15600 		}
15601 		/*
15602 		 * Any init based on sequence numbers
15603 		 * should be done in the deferred init path
15604 		 * since we can be CLOSED and not have them
15605 		 * inited when rack_init() is called. We
15606 		 * are not closed so lets call it.
15607 		 */
15608 		rack_deferred_init(tp, rack);
15609 	}
15610 	if ((tp->t_state != TCPS_CLOSED) &&
15611 	    (tp->t_state != TCPS_TIME_WAIT) &&
15612 	    (no_query == 0) &&
15613 	    (tp->snd_una != tp->snd_max))  {
15614 		err = rack_init_outstanding(tp, rack, us_cts, *ptr);
15615 		if (err) {
15616 			*ptr = NULL;
15617 			return(err);
15618 		}
15619 	}
15620 	rack_stop_all_timers(tp, rack);
15621 	/* Setup all the t_flags2 */
15622 	if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
15623 		tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
15624 	else
15625 		tp->t_flags2 &= ~TF2_SUPPORTS_MBUFQ;
15626 	if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
15627 		tp->t_flags2 |= TF2_MBUF_ACKCMP;
15628 	/*
15629 	 * Timers in Rack are kept in microseconds so lets
15630 	 * convert any initial incoming variables
15631 	 * from ticks into usecs. Note that we
15632 	 * also change the values of t_srtt and t_rttvar, if
15633 	 * they are non-zero. They are kept with a 5
15634 	 * bit decimal so we have to carefully convert
15635 	 * these to get the full precision.
15636 	 */
15637 	rack_convert_rtts(tp);
15638 	rack_log_hystart_event(rack, rack->r_ctl.roundends, 20);
15639 	if ((tptoinpcb(tp)->inp_flags & INP_DROPPED) == 0) {
15640 		/* We do not start any timers on DROPPED connections */
15641 		if (tp->t_fb->tfb_chg_query == NULL) {
15642 			rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
15643 		} else {
15644 			struct tcp_query_resp qr;
15645 			int ret;
15646 
15647 			memset(&qr, 0, sizeof(qr));
15648 
15649 			/* Get the misc time stamps and such for rack */
15650 			qr.req = TCP_QUERY_RACK_TIMES;
15651 			ret = (*tp->t_fb->tfb_chg_query)(tp, &qr);
15652 			if (ret == 1) {
15653 				rack->r_ctl.rc_reorder_ts = qr.rack_reorder_ts;
15654 				rack->r_ctl.num_dsack  = qr.rack_num_dsacks;
15655 				rack->r_ctl.rc_tlp_rxt_last_time = qr.rack_rxt_last_time;
15656 				rack->r_ctl.rc_rack_min_rtt = qr.rack_min_rtt;
15657 				rack->rc_rack_rtt = qr.rack_rtt;
15658 				rack->r_ctl.rc_rack_tmit_time = qr.rack_tmit_time;
15659 				rack->r_ctl.rc_sacked = qr.rack_sacked;
15660 				rack->r_ctl.rc_holes_rxt = qr.rack_holes_rxt;
15661 				rack->r_ctl.rc_prr_delivered = qr.rack_prr_delivered;
15662 				rack->r_ctl.rc_prr_recovery_fs = qr.rack_prr_recovery_fs;
15663 				rack->r_ctl.rc_prr_sndcnt = qr.rack_prr_sndcnt;
15664 				rack->r_ctl.rc_prr_out = qr.rack_prr_out;
15665 				if (qr.rack_tlp_out) {
15666 					rack->rc_tlp_in_progress = 1;
15667 					rack->r_ctl.rc_tlp_cnt_out = qr.rack_tlp_cnt_out;
15668 				} else {
15669 					rack->rc_tlp_in_progress = 0;
15670 					rack->r_ctl.rc_tlp_cnt_out = 0;
15671 				}
15672 				if (qr.rack_srtt_measured)
15673 					rack->rc_srtt_measure_made = 1;
15674 				if (qr.rack_in_persist == 1) {
15675 					rack->r_ctl.rc_went_idle_time = qr.rack_time_went_idle;
15676 #ifdef NETFLIX_SHARED_CWND
15677 					if (rack->r_ctl.rc_scw) {
15678 						tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
15679 						rack->rack_scwnd_is_idle = 1;
15680 					}
15681 #endif
15682 					rack->r_ctl.persist_lost_ends = 0;
15683 					rack->probe_not_answered = 0;
15684 					rack->forced_ack = 0;
15685 					tp->t_rxtshift = 0;
15686 					rack->rc_in_persist = 1;
15687 					RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
15688 							   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
15689 				}
15690 				if (qr.rack_wanted_output)
15691 					rack->r_wanted_output = 1;
15692 				rack_log_chg_info(tp, rack, 6,
15693 						  qr.rack_min_rtt,
15694 						  qr.rack_rtt,
15695 						  qr.rack_reorder_ts);
15696 			}
15697 			/* Get the old stack timers */
15698 			qr.req_param = 0;
15699 			qr.req = TCP_QUERY_TIMERS_UP;
15700 			ret = (*tp->t_fb->tfb_chg_query)(tp, &qr);
15701 			if (ret) {
15702 				/*
15703 				 * non-zero return means we have a timer('s)
15704 				 * to start. Zero means no timer (no keepalive
15705 				 * I suppose).
15706 				 */
15707 				uint32_t tov = 0;
15708 
15709 				rack->r_ctl.rc_hpts_flags = qr.timer_hpts_flags;
15710 				if (qr.timer_hpts_flags & PACE_PKT_OUTPUT) {
15711 					rack->r_ctl.rc_last_output_to = qr.timer_pacing_to;
15712 					if (TSTMP_GT(qr.timer_pacing_to, us_cts))
15713 						tov = qr.timer_pacing_to - us_cts;
15714 					else
15715 						tov = HPTS_TICKS_PER_SLOT;
15716 				}
15717 				if (qr.timer_hpts_flags & PACE_TMR_MASK) {
15718 					rack->r_ctl.rc_timer_exp = qr.timer_timer_exp;
15719 					if (tov == 0) {
15720 						if (TSTMP_GT(qr.timer_timer_exp, us_cts))
15721 							tov = qr.timer_timer_exp - us_cts;
15722 						else
15723 							tov = HPTS_TICKS_PER_SLOT;
15724 					}
15725 				}
15726 				rack_log_chg_info(tp, rack, 4,
15727 						  rack->r_ctl.rc_hpts_flags,
15728 						  rack->r_ctl.rc_last_output_to,
15729 						  rack->r_ctl.rc_timer_exp);
15730 				if (tov) {
15731 					struct hpts_diag diag;
15732 
15733 					(void)tcp_hpts_insert_diag(tp, HPTS_USEC_TO_SLOTS(tov),
15734 								   __LINE__, &diag);
15735 					rack_log_hpts_diag(rack, us_cts, &diag, &rack->r_ctl.act_rcv_time);
15736 				}
15737 			}
15738 		}
15739 		rack_log_rtt_shrinks(rack,  us_cts,  tp->t_rxtcur,
15740 				     __LINE__, RACK_RTTS_INIT);
15741 	}
15742 	return (0);
15743 }
15744 
15745 static int
rack_handoff_ok(struct tcpcb * tp)15746 rack_handoff_ok(struct tcpcb *tp)
15747 {
15748 	if ((tp->t_state == TCPS_CLOSED) ||
15749 	    (tp->t_state == TCPS_LISTEN)) {
15750 		/* Sure no problem though it may not stick */
15751 		return (0);
15752 	}
15753 	if ((tp->t_state == TCPS_SYN_SENT) ||
15754 	    (tp->t_state == TCPS_SYN_RECEIVED)) {
15755 		/*
15756 		 * We really don't know if you support sack,
15757 		 * you have to get to ESTAB or beyond to tell.
15758 		 */
15759 		return (EAGAIN);
15760 	}
15761 	if ((tp->t_flags & TF_SENTFIN) && ((tp->snd_max - tp->snd_una) > 1)) {
15762 		/*
15763 		 * Rack will only send a FIN after all data is acknowledged.
15764 		 * So in this case we have more data outstanding. We can't
15765 		 * switch stacks until either all data and only the FIN
15766 		 * is left (in which case rack_init() now knows how
15767 		 * to deal with that) <or> all is acknowledged and we
15768 		 * are only left with incoming data, though why you
15769 		 * would want to switch to rack after all data is acknowledged
15770 		 * I have no idea (rrs)!
15771 		 */
15772 		return (EAGAIN);
15773 	}
15774 	if ((tp->t_flags & TF_SACK_PERMIT) || rack_sack_not_required){
15775 		return (0);
15776 	}
15777 	/*
15778 	 * If we reach here we don't do SACK on this connection so we can
15779 	 * never do rack.
15780 	 */
15781 	return (EINVAL);
15782 }
15783 
15784 static void
rack_fini(struct tcpcb * tp,int32_t tcb_is_purged)15785 rack_fini(struct tcpcb *tp, int32_t tcb_is_purged)
15786 {
15787 
15788 	if (tp->t_fb_ptr) {
15789 		uint32_t cnt_free = 0;
15790 		struct tcp_rack *rack;
15791 		struct rack_sendmap *rsm;
15792 
15793 		tcp_handle_orphaned_packets(tp);
15794 		tp->t_flags &= ~TF_FORCEDATA;
15795 		rack = (struct tcp_rack *)tp->t_fb_ptr;
15796 		rack_log_pacing_delay_calc(rack,
15797 					   0,
15798 					   0,
15799 					   0,
15800 					   rack_get_gp_est(rack), /* delRate */
15801 					   rack_get_lt_bw(rack), /* rttProp */
15802 					   20, __LINE__, NULL, 0);
15803 #ifdef NETFLIX_SHARED_CWND
15804 		if (rack->r_ctl.rc_scw) {
15805 			uint32_t limit;
15806 
15807 			if (rack->r_limit_scw)
15808 				limit = max(1, rack->r_ctl.rc_lowest_us_rtt);
15809 			else
15810 				limit = 0;
15811 			tcp_shared_cwnd_free_full(tp, rack->r_ctl.rc_scw,
15812 						  rack->r_ctl.rc_scw_index,
15813 						  limit);
15814 			rack->r_ctl.rc_scw = NULL;
15815 		}
15816 #endif
15817 		if (rack->r_ctl.fsb.tcp_ip_hdr) {
15818 			free(rack->r_ctl.fsb.tcp_ip_hdr, M_TCPFSB);
15819 			rack->r_ctl.fsb.tcp_ip_hdr = NULL;
15820 			rack->r_ctl.fsb.th = NULL;
15821 		}
15822 		if (rack->rc_always_pace == 1) {
15823 			rack_remove_pacing(rack);
15824 		}
15825 		/* Clean up any options if they were not applied */
15826 		while (!TAILQ_EMPTY(&rack->r_ctl.opt_list)) {
15827 			struct deferred_opt_list *dol;
15828 
15829 			dol = TAILQ_FIRST(&rack->r_ctl.opt_list);
15830 			TAILQ_REMOVE(&rack->r_ctl.opt_list, dol, next);
15831 			free(dol, M_TCPDO);
15832 		}
15833 		/* rack does not use force data but other stacks may clear it */
15834 		if (rack->r_ctl.crte != NULL) {
15835 			tcp_rel_pacing_rate(rack->r_ctl.crte, tp);
15836 			rack->rack_hdrw_pacing = 0;
15837 			rack->r_ctl.crte = NULL;
15838 		}
15839 #ifdef TCP_BLACKBOX
15840 		tcp_log_flowend(tp);
15841 #endif
15842 		/*
15843 		 * Lets take a different approach to purging just
15844 		 * get each one and free it like a cum-ack would and
15845 		 * not use a foreach loop.
15846 		 */
15847 		rsm = tqhash_min(rack->r_ctl.tqh);
15848 		while (rsm) {
15849 			tqhash_remove(rack->r_ctl.tqh, rsm, REMOVE_TYPE_CUMACK);
15850 			rack->r_ctl.rc_num_maps_alloced--;
15851 			uma_zfree(rack_zone, rsm);
15852 			rsm = tqhash_min(rack->r_ctl.tqh);
15853 		}
15854 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
15855 		while (rsm) {
15856 			TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
15857 			rack->r_ctl.rc_num_maps_alloced--;
15858 			rack->rc_free_cnt--;
15859 			cnt_free++;
15860 			uma_zfree(rack_zone, rsm);
15861 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
15862 		}
15863 		if (rack->r_ctl.pcm_s != NULL) {
15864 			free(rack->r_ctl.pcm_s, M_TCPPCM);
15865 			rack->r_ctl.pcm_s = NULL;
15866 			rack->r_ctl.pcm_i.cnt_alloc = 0;
15867 			rack->r_ctl.pcm_i.cnt = 0;
15868 		}
15869 		if ((rack->r_ctl.rc_num_maps_alloced > 0) &&
15870 		    (tcp_bblogging_on(tp))) {
15871 			union tcp_log_stackspecific log;
15872 			struct timeval tv;
15873 
15874 			memset(&log.u_bbr, 0, sizeof(log.u_bbr));
15875 			log.u_bbr.flex8 = 10;
15876 			log.u_bbr.flex1 = rack->r_ctl.rc_num_maps_alloced;
15877 			log.u_bbr.flex2 = rack->rc_free_cnt;
15878 			log.u_bbr.flex3 = cnt_free;
15879 			log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
15880 			rsm = tqhash_min(rack->r_ctl.tqh);
15881 			log.u_bbr.delRate = (uint64_t)rsm;
15882 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
15883 			log.u_bbr.cur_del_rate = (uint64_t)rsm;
15884 			log.u_bbr.timeStamp = tcp_get_usecs(&tv);
15885 			log.u_bbr.pkt_epoch = __LINE__;
15886 			(void)tcp_log_event(tp, NULL, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
15887 					     0, &log, false, NULL, NULL, 0, &tv);
15888 		}
15889 		KASSERT((rack->r_ctl.rc_num_maps_alloced == 0),
15890 			("rack:%p num_aloc:%u after freeing all?",
15891 			 rack,
15892 			 rack->r_ctl.rc_num_maps_alloced));
15893 		rack->rc_free_cnt = 0;
15894 		free(rack->r_ctl.tqh, M_TCPFSB);
15895 		rack->r_ctl.tqh = NULL;
15896 		uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
15897 		tp->t_fb_ptr = NULL;
15898 	}
15899 	/* Make sure snd_nxt is correctly set */
15900 	tp->snd_nxt = tp->snd_max;
15901 }
15902 
15903 static void
rack_set_state(struct tcpcb * tp,struct tcp_rack * rack)15904 rack_set_state(struct tcpcb *tp, struct tcp_rack *rack)
15905 {
15906 	if ((rack->r_state == TCPS_CLOSED) && (tp->t_state != TCPS_CLOSED)) {
15907 		rack->r_is_v6 = (tptoinpcb(tp)->inp_vflag & INP_IPV6) != 0;
15908 	}
15909 	switch (tp->t_state) {
15910 	case TCPS_SYN_SENT:
15911 		rack->r_state = TCPS_SYN_SENT;
15912 		rack->r_substate = rack_do_syn_sent;
15913 		break;
15914 	case TCPS_SYN_RECEIVED:
15915 		rack->r_state = TCPS_SYN_RECEIVED;
15916 		rack->r_substate = rack_do_syn_recv;
15917 		break;
15918 	case TCPS_ESTABLISHED:
15919 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
15920 		rack->r_state = TCPS_ESTABLISHED;
15921 		rack->r_substate = rack_do_established;
15922 		break;
15923 	case TCPS_CLOSE_WAIT:
15924 		rack->r_state = TCPS_CLOSE_WAIT;
15925 		rack->r_substate = rack_do_close_wait;
15926 		break;
15927 	case TCPS_FIN_WAIT_1:
15928 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
15929 		rack->r_state = TCPS_FIN_WAIT_1;
15930 		rack->r_substate = rack_do_fin_wait_1;
15931 		break;
15932 	case TCPS_CLOSING:
15933 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
15934 		rack->r_state = TCPS_CLOSING;
15935 		rack->r_substate = rack_do_closing;
15936 		break;
15937 	case TCPS_LAST_ACK:
15938 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
15939 		rack->r_state = TCPS_LAST_ACK;
15940 		rack->r_substate = rack_do_lastack;
15941 		break;
15942 	case TCPS_FIN_WAIT_2:
15943 		rack->r_state = TCPS_FIN_WAIT_2;
15944 		rack->r_substate = rack_do_fin_wait_2;
15945 		break;
15946 	case TCPS_LISTEN:
15947 	case TCPS_CLOSED:
15948 	case TCPS_TIME_WAIT:
15949 	default:
15950 		break;
15951 	};
15952 	if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
15953 		rack->rc_tp->t_flags2 |= TF2_MBUF_ACKCMP;
15954 
15955 }
15956 
15957 static void
rack_timer_audit(struct tcpcb * tp,struct tcp_rack * rack,struct sockbuf * sb)15958 rack_timer_audit(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb)
15959 {
15960 	/*
15961 	 * We received an ack, and then did not
15962 	 * call send or were bounced out due to the
15963 	 * hpts was running. Now a timer is up as well, is
15964 	 * it the right timer?
15965 	 */
15966 	struct rack_sendmap *rsm;
15967 	int tmr_up;
15968 
15969 	tmr_up = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
15970 	if (tcp_in_hpts(rack->rc_tp) == 0) {
15971 		/*
15972 		 * Ok we probably need some timer up, but no
15973 		 * matter what the mask we are not in hpts. We
15974 		 * may have received an old ack and thus did nothing.
15975 		 */
15976 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
15977 		rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
15978 		return;
15979 	}
15980 	if (rack->rc_in_persist && (tmr_up == PACE_TMR_PERSIT))
15981 		return;
15982 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
15983 	if (((rsm == NULL) || (tp->t_state < TCPS_ESTABLISHED)) &&
15984 	    (tmr_up == PACE_TMR_RXT)) {
15985 		/* Should be an RXT */
15986 		return;
15987 	}
15988 	if (rsm == NULL) {
15989 		/* Nothing outstanding? */
15990 		if (tp->t_flags & TF_DELACK) {
15991 			if (tmr_up == PACE_TMR_DELACK)
15992 				/* We are supposed to have delayed ack up and we do */
15993 				return;
15994 		} else if (sbavail(&tptosocket(tp)->so_snd) && (tmr_up == PACE_TMR_RXT)) {
15995 			/*
15996 			 * if we hit enobufs then we would expect the possibility
15997 			 * of nothing outstanding and the RXT up (and the hptsi timer).
15998 			 */
15999 			return;
16000 		} else if (((V_tcp_always_keepalive ||
16001 			     rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
16002 			    (tp->t_state <= TCPS_CLOSING)) &&
16003 			   (tmr_up == PACE_TMR_KEEP) &&
16004 			   (tp->snd_max == tp->snd_una)) {
16005 			/* We should have keep alive up and we do */
16006 			return;
16007 		}
16008 	}
16009 	if (SEQ_GT(tp->snd_max, tp->snd_una) &&
16010 		   ((tmr_up == PACE_TMR_TLP) ||
16011 		    (tmr_up == PACE_TMR_RACK) ||
16012 		    (tmr_up == PACE_TMR_RXT))) {
16013 		/*
16014 		 * Either a Rack, TLP or RXT is fine if  we
16015 		 * have outstanding data.
16016 		 */
16017 		return;
16018 	} else if (tmr_up == PACE_TMR_DELACK) {
16019 		/*
16020 		 * If the delayed ack was going to go off
16021 		 * before the rtx/tlp/rack timer were going to
16022 		 * expire, then that would be the timer in control.
16023 		 * Note we don't check the time here trusting the
16024 		 * code is correct.
16025 		 */
16026 		return;
16027 	}
16028 	/*
16029 	 * Ok the timer originally started is not what we want now.
16030 	 * We will force the hpts to be stopped if any, and restart
16031 	 * with the slot set to what was in the saved slot.
16032 	 */
16033 	if (tcp_in_hpts(rack->rc_tp)) {
16034 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
16035 			uint32_t us_cts;
16036 
16037 			us_cts = tcp_get_usecs(NULL);
16038 			if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
16039 				rack->r_early = 1;
16040 				rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
16041 			}
16042 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
16043 		}
16044 		tcp_hpts_remove(rack->rc_tp);
16045 	}
16046 	rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
16047 	rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
16048 }
16049 
16050 
16051 static void
rack_do_win_updates(struct tcpcb * tp,struct tcp_rack * rack,uint32_t tiwin,uint32_t seq,uint32_t ack,uint32_t cts)16052 rack_do_win_updates(struct tcpcb *tp, struct tcp_rack *rack, uint32_t tiwin, uint32_t seq, uint32_t ack, uint32_t cts)
16053 {
16054 	if ((SEQ_LT(tp->snd_wl1, seq) ||
16055 	    (tp->snd_wl1 == seq && (SEQ_LT(tp->snd_wl2, ack) ||
16056 	    (tp->snd_wl2 == ack && tiwin > tp->snd_wnd))))) {
16057 		/* keep track of pure window updates */
16058 		if ((tp->snd_wl2 == ack) && (tiwin > tp->snd_wnd))
16059 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
16060 		tp->snd_wnd = tiwin;
16061 		rack_validate_fo_sendwin_up(tp, rack);
16062 		tp->snd_wl1 = seq;
16063 		tp->snd_wl2 = ack;
16064 		if (tp->snd_wnd > tp->max_sndwnd)
16065 			tp->max_sndwnd = tp->snd_wnd;
16066 	    rack->r_wanted_output = 1;
16067 	} else if ((tp->snd_wl2 == ack) && (tiwin < tp->snd_wnd)) {
16068 		tp->snd_wnd = tiwin;
16069 		rack_validate_fo_sendwin_up(tp, rack);
16070 		tp->snd_wl1 = seq;
16071 		tp->snd_wl2 = ack;
16072 	} else {
16073 		/* Not a valid win update */
16074 		return;
16075 	}
16076 	if (tp->snd_wnd > tp->max_sndwnd)
16077 		tp->max_sndwnd = tp->snd_wnd;
16078 	/* Do we exit persists? */
16079 	if ((rack->rc_in_persist != 0) &&
16080 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
16081 				rack->r_ctl.rc_pace_min_segs))) {
16082 		rack_exit_persist(tp, rack, cts);
16083 	}
16084 	/* Do we enter persists? */
16085 	if ((rack->rc_in_persist == 0) &&
16086 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
16087 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
16088 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
16089 	    sbavail(&tptosocket(tp)->so_snd) &&
16090 	    (sbavail(&tptosocket(tp)->so_snd) > tp->snd_wnd)) {
16091 		/*
16092 		 * Here the rwnd is less than
16093 		 * the pacing size, we are established,
16094 		 * nothing is outstanding, and there is
16095 		 * data to send. Enter persists.
16096 		 */
16097 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime, ack);
16098 	}
16099 }
16100 
16101 static void
rack_log_input_packet(struct tcpcb * tp,struct tcp_rack * rack,struct tcp_ackent * ae,int ackval,uint32_t high_seq)16102 rack_log_input_packet(struct tcpcb *tp, struct tcp_rack *rack, struct tcp_ackent *ae, int ackval, uint32_t high_seq)
16103 {
16104 
16105 	if (tcp_bblogging_on(rack->rc_tp)) {
16106 		struct inpcb *inp = tptoinpcb(tp);
16107 		union tcp_log_stackspecific log;
16108 		struct timeval ltv;
16109 		char tcp_hdr_buf[60];
16110 		struct tcphdr *th;
16111 		struct timespec ts;
16112 		uint32_t orig_snd_una;
16113 		uint8_t xx = 0;
16114 
16115 #ifdef TCP_REQUEST_TRK
16116 		struct tcp_sendfile_track *tcp_req;
16117 
16118 		if (SEQ_GT(ae->ack, tp->snd_una)) {
16119 			tcp_req = tcp_req_find_req_for_seq(tp, (ae->ack-1));
16120 		} else {
16121 			tcp_req = tcp_req_find_req_for_seq(tp, ae->ack);
16122 		}
16123 #endif
16124 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
16125 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
16126 		if (rack->rack_no_prr == 0)
16127 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
16128 		else
16129 			log.u_bbr.flex1 = 0;
16130 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
16131 		log.u_bbr.use_lt_bw <<= 1;
16132 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
16133 		log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
16134 		log.u_bbr.bbr_state = rack->rc_free_cnt;
16135 		log.u_bbr.inflight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
16136 		log.u_bbr.pkts_out = tp->t_maxseg;
16137 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
16138 		log.u_bbr.flex7 = 1;
16139 		log.u_bbr.lost = ae->flags;
16140 		log.u_bbr.cwnd_gain = ackval;
16141 		log.u_bbr.pacing_gain = 0x2;
16142 		if (ae->flags & TSTMP_HDWR) {
16143 			/* Record the hardware timestamp if present */
16144 			log.u_bbr.flex3 = M_TSTMP;
16145 			ts.tv_sec = ae->timestamp / 1000000000;
16146 			ts.tv_nsec = ae->timestamp % 1000000000;
16147 			ltv.tv_sec = ts.tv_sec;
16148 			ltv.tv_usec = ts.tv_nsec / 1000;
16149 			log.u_bbr.lt_epoch = tcp_tv_to_usectick(&ltv);
16150 		} else if (ae->flags & TSTMP_LRO) {
16151 			/* Record the LRO the arrival timestamp */
16152 			log.u_bbr.flex3 = M_TSTMP_LRO;
16153 			ts.tv_sec = ae->timestamp / 1000000000;
16154 			ts.tv_nsec = ae->timestamp % 1000000000;
16155 			ltv.tv_sec = ts.tv_sec;
16156 			ltv.tv_usec = ts.tv_nsec / 1000;
16157 			log.u_bbr.flex5 = tcp_tv_to_usectick(&ltv);
16158 		}
16159 		log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
16160 		/* Log the rcv time */
16161 		log.u_bbr.delRate = ae->timestamp;
16162 #ifdef TCP_REQUEST_TRK
16163 		log.u_bbr.applimited = tp->t_tcpreq_closed;
16164 		log.u_bbr.applimited <<= 8;
16165 		log.u_bbr.applimited |= tp->t_tcpreq_open;
16166 		log.u_bbr.applimited <<= 8;
16167 		log.u_bbr.applimited |= tp->t_tcpreq_req;
16168 		if (tcp_req) {
16169 			/* Copy out any client req info */
16170 			/* seconds */
16171 			log.u_bbr.pkt_epoch = (tcp_req->localtime / HPTS_USEC_IN_SEC);
16172 			/* useconds */
16173 			log.u_bbr.delivered = (tcp_req->localtime % HPTS_USEC_IN_SEC);
16174 			log.u_bbr.rttProp = tcp_req->timestamp;
16175 			log.u_bbr.cur_del_rate = tcp_req->start;
16176 			if (tcp_req->flags & TCP_TRK_TRACK_FLG_OPEN) {
16177 				log.u_bbr.flex8 |= 1;
16178 			} else {
16179 				log.u_bbr.flex8 |= 2;
16180 				log.u_bbr.bw_inuse = tcp_req->end;
16181 			}
16182 			log.u_bbr.flex6 = tcp_req->start_seq;
16183 			if (tcp_req->flags & TCP_TRK_TRACK_FLG_COMP) {
16184 				log.u_bbr.flex8 |= 4;
16185 				log.u_bbr.epoch = tcp_req->end_seq;
16186 			}
16187 		}
16188 #endif
16189 		memset(tcp_hdr_buf, 0, sizeof(tcp_hdr_buf));
16190 		th = (struct tcphdr *)tcp_hdr_buf;
16191 		th->th_seq = ae->seq;
16192 		th->th_ack = ae->ack;
16193 		th->th_win = ae->win;
16194 		/* Now fill in the ports */
16195 		th->th_sport = inp->inp_fport;
16196 		th->th_dport = inp->inp_lport;
16197 		tcp_set_flags(th, ae->flags);
16198 		/* Now do we have a timestamp option? */
16199 		if (ae->flags & HAS_TSTMP) {
16200 			u_char *cp;
16201 			uint32_t val;
16202 
16203 			th->th_off = ((sizeof(struct tcphdr) + TCPOLEN_TSTAMP_APPA) >> 2);
16204 			cp = (u_char *)(th + 1);
16205 			*cp = TCPOPT_NOP;
16206 			cp++;
16207 			*cp = TCPOPT_NOP;
16208 			cp++;
16209 			*cp = TCPOPT_TIMESTAMP;
16210 			cp++;
16211 			*cp = TCPOLEN_TIMESTAMP;
16212 			cp++;
16213 			val = htonl(ae->ts_value);
16214 			bcopy((char *)&val,
16215 			      (char *)cp, sizeof(uint32_t));
16216 			val = htonl(ae->ts_echo);
16217 			bcopy((char *)&val,
16218 			      (char *)(cp + 4), sizeof(uint32_t));
16219 		} else
16220 			th->th_off = (sizeof(struct tcphdr) >> 2);
16221 
16222 		/*
16223 		 * For sane logging we need to play a little trick.
16224 		 * If the ack were fully processed we would have moved
16225 		 * snd_una to high_seq, but since compressed acks are
16226 		 * processed in two phases, at this point (logging) snd_una
16227 		 * won't be advanced. So we would see multiple acks showing
16228 		 * the advancement. We can prevent that by "pretending" that
16229 		 * snd_una was advanced and then un-advancing it so that the
16230 		 * logging code has the right value for tlb_snd_una.
16231 		 */
16232 		if (tp->snd_una != high_seq) {
16233 			orig_snd_una = tp->snd_una;
16234 			tp->snd_una = high_seq;
16235 			xx = 1;
16236 		} else
16237 			xx = 0;
16238 		TCP_LOG_EVENTP(tp, th,
16239 			       &tptosocket(tp)->so_rcv,
16240 			       &tptosocket(tp)->so_snd, TCP_LOG_IN, 0,
16241 			       0, &log, true, &ltv);
16242 		if (xx) {
16243 			tp->snd_una = orig_snd_una;
16244 		}
16245 	}
16246 
16247 }
16248 
16249 static void
rack_handle_probe_response(struct tcp_rack * rack,uint32_t tiwin,uint32_t us_cts)16250 rack_handle_probe_response(struct tcp_rack *rack, uint32_t tiwin, uint32_t us_cts)
16251 {
16252 	uint32_t us_rtt;
16253 	/*
16254 	 * A persist or keep-alive was forced out, update our
16255 	 * min rtt time. Note now worry about lost responses.
16256 	 * When a subsequent keep-alive or persist times out
16257 	 * and forced_ack is still on, then the last probe
16258 	 * was not responded to. In such cases we have a
16259 	 * sysctl that controls the behavior. Either we apply
16260 	 * the rtt but with reduced confidence (0). Or we just
16261 	 * plain don't apply the rtt estimate. Having data flow
16262 	 * will clear the probe_not_answered flag i.e. cum-ack
16263 	 * move forward <or> exiting and reentering persists.
16264 	 */
16265 
16266 	rack->forced_ack = 0;
16267 	rack->rc_tp->t_rxtshift = 0;
16268 	if ((rack->rc_in_persist &&
16269 	     (tiwin == rack->rc_tp->snd_wnd)) ||
16270 	    (rack->rc_in_persist == 0)) {
16271 		/*
16272 		 * In persists only apply the RTT update if this is
16273 		 * a response to our window probe. And that
16274 		 * means the rwnd sent must match the current
16275 		 * snd_wnd. If it does not, then we got a
16276 		 * window update ack instead. For keepalive
16277 		 * we allow the answer no matter what the window.
16278 		 *
16279 		 * Note that if the probe_not_answered is set then
16280 		 * the forced_ack_ts is the oldest one i.e. the first
16281 		 * probe sent that might have been lost. This assures
16282 		 * us that if we do calculate an RTT it is longer not
16283 		 * some short thing.
16284 		 */
16285 		if (rack->rc_in_persist)
16286 			counter_u64_add(rack_persists_acks, 1);
16287 		us_rtt = us_cts - rack->r_ctl.forced_ack_ts;
16288 		if (us_rtt == 0)
16289 			us_rtt = 1;
16290 		if (rack->probe_not_answered == 0) {
16291 			rack_apply_updated_usrtt(rack, us_rtt, us_cts);
16292 			tcp_rack_xmit_timer(rack, us_rtt, 0, us_rtt, 3, NULL, 1);
16293 		} else {
16294 			/* We have a retransmitted probe here too */
16295 			if (rack_apply_rtt_with_reduced_conf) {
16296 				rack_apply_updated_usrtt(rack, us_rtt, us_cts);
16297 				tcp_rack_xmit_timer(rack, us_rtt, 0, us_rtt, 0, NULL, 1);
16298 			}
16299 		}
16300 	}
16301 }
16302 
16303 static void
rack_new_round_starts(struct tcpcb * tp,struct tcp_rack * rack,uint32_t high_seq)16304 rack_new_round_starts(struct tcpcb *tp, struct tcp_rack *rack, uint32_t high_seq)
16305 {
16306 	/*
16307 	 * The next send has occurred mark the end of the round
16308 	 * as when that data gets acknowledged. We can
16309 	 * also do common things we might need to do when
16310 	 * a round begins.
16311 	 */
16312 	rack->r_ctl.roundends = tp->snd_max;
16313 	rack->rc_new_rnd_needed = 0;
16314 	rack_log_hystart_event(rack, tp->snd_max, 4);
16315 }
16316 
16317 
16318 static void
rack_log_pcm(struct tcp_rack * rack,uint8_t mod,uint32_t flex1,uint32_t flex2,uint32_t flex3)16319 rack_log_pcm(struct tcp_rack *rack, uint8_t mod, uint32_t flex1, uint32_t flex2,
16320 	     uint32_t flex3)
16321 {
16322 	if (tcp_bblogging_on(rack->rc_tp)) {
16323 		union tcp_log_stackspecific log;
16324 		struct timeval tv;
16325 
16326 		(void)tcp_get_usecs(&tv);
16327 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
16328 		log.u_bbr.timeStamp = tcp_tv_to_usectick(&tv);
16329 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
16330 		log.u_bbr.flex8 = mod;
16331 		log.u_bbr.flex1 = flex1;
16332 		log.u_bbr.flex2 = flex2;
16333 		log.u_bbr.flex3 = flex3;
16334 		log.u_bbr.flex4 = rack_pcm_every_n_rounds;
16335 		log.u_bbr.flex5 = rack->r_ctl.pcm_idle_rounds;
16336 		log.u_bbr.bbr_substate = rack->pcm_needed;
16337 		log.u_bbr.bbr_substate <<= 1;
16338 		log.u_bbr.bbr_substate |= rack->pcm_in_progress;
16339 		log.u_bbr.bbr_substate <<= 1;
16340 		log.u_bbr.bbr_substate |= rack->pcm_enabled; /* bits are NIE for Needed, Inprogress, Enabled */
16341 		(void)tcp_log_event(rack->rc_tp, NULL, NULL, NULL, TCP_PCM_MEASURE, ERRNO_UNK,
16342 				    0, &log, false, NULL, NULL, 0, &tv);
16343 	}
16344 }
16345 
16346 static void
rack_new_round_setup(struct tcpcb * tp,struct tcp_rack * rack,uint32_t high_seq)16347 rack_new_round_setup(struct tcpcb *tp, struct tcp_rack *rack, uint32_t high_seq)
16348 {
16349 	/*
16350 	 * The round (current_round) has ended. We now
16351 	 * setup for the next round by incrementing the
16352 	 * round numnber and doing any round specific
16353 	 * things.
16354 	 */
16355 	rack_log_hystart_event(rack, high_seq, 21);
16356 	rack->r_ctl.current_round++;
16357 	/* New round (current_round) begins at next send */
16358 	rack->rc_new_rnd_needed = 1;
16359 	if ((rack->pcm_enabled == 1) &&
16360 	    (rack->pcm_needed == 0) &&
16361 	    (rack->pcm_in_progress == 0)) {
16362 		/*
16363 		 * If we have enabled PCM, then we need to
16364 		 * check if the round has adanced to the state
16365 		 * where one is required.
16366 		 */
16367 		int rnds;
16368 
16369 		rnds = rack->r_ctl.current_round - rack->r_ctl.last_pcm_round;
16370 		if ((rnds + rack->r_ctl.pcm_idle_rounds) >= rack_pcm_every_n_rounds) {
16371 			rack->pcm_needed = 1;
16372 			rack_log_pcm(rack, 3, rack->r_ctl.last_pcm_round, rack_pcm_every_n_rounds, rack->r_ctl.current_round );
16373 		} else if (rack_verbose_logging) {
16374 			rack_log_pcm(rack, 3, rack->r_ctl.last_pcm_round, rack_pcm_every_n_rounds, rack->r_ctl.current_round );
16375 		}
16376 	}
16377 	if (tp->t_ccv.flags & CCF_HYSTART_ALLOWED) {
16378 		/* We have hystart enabled send the round info in */
16379 		if (CC_ALGO(tp)->newround != NULL) {
16380 			CC_ALGO(tp)->newround(&tp->t_ccv, rack->r_ctl.current_round);
16381 		}
16382 	}
16383 	/*
16384 	 * For DGP an initial startup check. We want to validate
16385 	 * that we are not just pushing on slow-start and just
16386 	 * not gaining.. i.e. filling buffers without getting any
16387 	 * boost in b/w during the inital slow-start.
16388 	 */
16389 	if (rack->dgp_on &&
16390 	    (rack->rc_initial_ss_comp == 0) &&
16391 	    (tp->snd_cwnd < tp->snd_ssthresh) &&
16392 	    (rack->r_ctl.num_measurements >= RACK_REQ_AVG) &&
16393 	    (rack->r_ctl.gp_rnd_thresh > 0) &&
16394 	    ((rack->r_ctl.current_round - rack->r_ctl.last_rnd_of_gp_rise) >= rack->r_ctl.gp_rnd_thresh)) {
16395 
16396 		/*
16397 		 * We are in the initial SS and we have hd rack_rnd_cnt_req rounds(def:5) where
16398 		 * we have not gained the required amount in the gp_est (120.0% aka 1200). Lets
16399 		 * exit SS.
16400 		 *
16401 		 * Pick up the flight size now as we enter slowstart (not the
16402 		 * cwnd which may be inflated).
16403 		 */
16404 		rack->rc_initial_ss_comp = 1;
16405 
16406 		if (tcp_bblogging_on(rack->rc_tp)) {
16407 			union tcp_log_stackspecific log;
16408 			struct timeval tv;
16409 
16410 			memset(&log.u_bbr, 0, sizeof(log.u_bbr));
16411 			log.u_bbr.timeStamp = tcp_get_usecs(&tv);
16412 			log.u_bbr.flex1 = rack->r_ctl.current_round;
16413 			log.u_bbr.flex2 = rack->r_ctl.last_rnd_of_gp_rise;
16414 			log.u_bbr.flex3 = rack->r_ctl.gp_rnd_thresh;
16415 			log.u_bbr.flex4 = rack->r_ctl.gate_to_fs;
16416 			log.u_bbr.flex5 = rack->r_ctl.ss_hi_fs;
16417 			log.u_bbr.flex8 = 40;
16418 			(void)tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
16419 					    0, &log, false, NULL, __func__, __LINE__,&tv);
16420 		}
16421 		if ((rack->r_ctl.gate_to_fs == 1) &&
16422 		     (tp->snd_cwnd > rack->r_ctl.ss_hi_fs)) {
16423 			tp->snd_cwnd = rack->r_ctl.ss_hi_fs;
16424 		}
16425 		tp->snd_ssthresh = tp->snd_cwnd - 1;
16426 		/* Turn off any fast output running */
16427 		rack->r_fast_output = 0;
16428 	}
16429 }
16430 
16431 static int
rack_do_compressed_ack_processing(struct tcpcb * tp,struct socket * so,struct mbuf * m,int nxt_pkt,struct timeval * tv)16432 rack_do_compressed_ack_processing(struct tcpcb *tp, struct socket *so, struct mbuf *m, int nxt_pkt, struct timeval *tv)
16433 {
16434 	/*
16435 	 * Handle a "special" compressed ack mbuf. Each incoming
16436 	 * ack has only four possible dispositions:
16437 	 *
16438 	 * A) It moves the cum-ack forward
16439 	 * B) It is behind the cum-ack.
16440 	 * C) It is a window-update ack.
16441 	 * D) It is a dup-ack.
16442 	 *
16443 	 * Note that we can have between 1 -> TCP_COMP_ACK_ENTRIES
16444 	 * in the incoming mbuf. We also need to still pay attention
16445 	 * to nxt_pkt since there may be another packet after this
16446 	 * one.
16447 	 */
16448 #ifdef TCP_ACCOUNTING
16449 	uint64_t ts_val;
16450 	uint64_t rdstc;
16451 #endif
16452 	int segsiz;
16453 	struct timespec ts;
16454 	struct tcp_rack *rack;
16455 	struct tcp_ackent *ae;
16456 	uint32_t tiwin, ms_cts, cts, acked, acked_amount, high_seq, win_seq, the_win, win_upd_ack;
16457 	int cnt, i, did_out, ourfinisacked = 0;
16458 	struct tcpopt to_holder, *to = NULL;
16459 #ifdef TCP_ACCOUNTING
16460 	int win_up_req = 0;
16461 #endif
16462 	int nsegs = 0;
16463 	int under_pacing = 0;
16464 	int post_recovery = 0;
16465 #ifdef TCP_ACCOUNTING
16466 	sched_pin();
16467 #endif
16468 	rack = (struct tcp_rack *)tp->t_fb_ptr;
16469 	if (rack->gp_ready &&
16470 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT))
16471 		under_pacing = 1;
16472 
16473 	if (rack->r_state != tp->t_state)
16474 		rack_set_state(tp, rack);
16475 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
16476 	    (tp->t_flags & TF_GPUTINPROG)) {
16477 		/*
16478 		 * We have a goodput in progress
16479 		 * and we have entered a late state.
16480 		 * Do we have enough data in the sb
16481 		 * to handle the GPUT request?
16482 		 */
16483 		uint32_t bytes;
16484 
16485 		bytes = tp->gput_ack - tp->gput_seq;
16486 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
16487 			bytes += tp->gput_seq - tp->snd_una;
16488 		if (bytes > sbavail(&tptosocket(tp)->so_snd)) {
16489 			/*
16490 			 * There are not enough bytes in the socket
16491 			 * buffer that have been sent to cover this
16492 			 * measurement. Cancel it.
16493 			 */
16494 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
16495 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
16496 						   tp->gput_seq,
16497 						   0, 0, 18, __LINE__, NULL, 0);
16498 			tp->t_flags &= ~TF_GPUTINPROG;
16499 		}
16500 	}
16501 	to = &to_holder;
16502 	to->to_flags = 0;
16503 	KASSERT((m->m_len >= sizeof(struct tcp_ackent)),
16504 		("tp:%p m_cmpack:%p with invalid len:%u", tp, m, m->m_len));
16505 	cnt = m->m_len / sizeof(struct tcp_ackent);
16506 	counter_u64_add(rack_multi_single_eq, cnt);
16507 	high_seq = tp->snd_una;
16508 	the_win = tp->snd_wnd;
16509 	win_seq = tp->snd_wl1;
16510 	win_upd_ack = tp->snd_wl2;
16511 	cts = tcp_tv_to_usectick(tv);
16512 	ms_cts = tcp_tv_to_mssectick(tv);
16513 	rack->r_ctl.rc_rcvtime = cts;
16514 	segsiz = ctf_fixed_maxseg(tp);
16515 	if ((rack->rc_gp_dyn_mul) &&
16516 	    (rack->use_fixed_rate == 0) &&
16517 	    (rack->rc_always_pace)) {
16518 		/* Check in on probertt */
16519 		rack_check_probe_rtt(rack, cts);
16520 	}
16521 	for (i = 0; i < cnt; i++) {
16522 #ifdef TCP_ACCOUNTING
16523 		ts_val = get_cyclecount();
16524 #endif
16525 		rack_clear_rate_sample(rack);
16526 		ae = ((mtod(m, struct tcp_ackent *)) + i);
16527 		if (ae->flags & TH_FIN)
16528 			rack_log_pacing_delay_calc(rack,
16529 						   0,
16530 						   0,
16531 						   0,
16532 						   rack_get_gp_est(rack), /* delRate */
16533 						   rack_get_lt_bw(rack), /* rttProp */
16534 						   20, __LINE__, NULL, 0);
16535 		/* Setup the window */
16536 		tiwin = ae->win << tp->snd_scale;
16537 		if (tiwin > rack->r_ctl.rc_high_rwnd)
16538 			rack->r_ctl.rc_high_rwnd = tiwin;
16539 		/* figure out the type of ack */
16540 		if (SEQ_LT(ae->ack, high_seq)) {
16541 			/* Case B*/
16542 			ae->ack_val_set = ACK_BEHIND;
16543 		} else if (SEQ_GT(ae->ack, high_seq)) {
16544 			/* Case A */
16545 			ae->ack_val_set = ACK_CUMACK;
16546 		} else if ((tiwin == the_win) && (rack->rc_in_persist == 0)){
16547 			/* Case D */
16548 			ae->ack_val_set = ACK_DUPACK;
16549 		} else {
16550 			/* Case C */
16551 			ae->ack_val_set = ACK_RWND;
16552 		}
16553 		rack_log_type_bbrsnd(rack, 0, 0, cts, tv, __LINE__);
16554 		rack_log_input_packet(tp, rack, ae, ae->ack_val_set, high_seq);
16555 		/* Validate timestamp */
16556 		if (ae->flags & HAS_TSTMP) {
16557 			/* Setup for a timestamp */
16558 			to->to_flags = TOF_TS;
16559 			ae->ts_echo -= tp->ts_offset;
16560 			to->to_tsecr = ae->ts_echo;
16561 			to->to_tsval = ae->ts_value;
16562 			/*
16563 			 * If echoed timestamp is later than the current time, fall back to
16564 			 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
16565 			 * were used when this connection was established.
16566 			 */
16567 			if (TSTMP_GT(ae->ts_echo, ms_cts))
16568 				to->to_tsecr = 0;
16569 			if (tp->ts_recent &&
16570 			    TSTMP_LT(ae->ts_value, tp->ts_recent)) {
16571 				if (ctf_ts_check_ac(tp, (ae->flags & 0xff))) {
16572 #ifdef TCP_ACCOUNTING
16573 					rdstc = get_cyclecount();
16574 					if (rdstc > ts_val) {
16575 						if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16576 							tp->tcp_proc_time[ae->ack_val_set] += (rdstc - ts_val);
16577 						}
16578 					}
16579 #endif
16580 					continue;
16581 				}
16582 			}
16583 			if (SEQ_LEQ(ae->seq, tp->last_ack_sent) &&
16584 			    SEQ_LEQ(tp->last_ack_sent, ae->seq)) {
16585 				tp->ts_recent_age = tcp_ts_getticks();
16586 				tp->ts_recent = ae->ts_value;
16587 			}
16588 		} else {
16589 			/* Setup for a no options */
16590 			to->to_flags = 0;
16591 		}
16592 		/* Update the rcv time and perform idle reduction possibly */
16593 		if  (tp->t_idle_reduce &&
16594 		     (tp->snd_max == tp->snd_una) &&
16595 		     (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
16596 			counter_u64_add(rack_input_idle_reduces, 1);
16597 			rack_cc_after_idle(rack, tp);
16598 		}
16599 		tp->t_rcvtime = ticks;
16600 		/* Now what about ECN of a chain of pure ACKs? */
16601 		if (tcp_ecn_input_segment(tp, ae->flags, 0,
16602 			tcp_packets_this_ack(tp, ae->ack),
16603 			ae->codepoint))
16604 			rack_cong_signal(tp, CC_ECN, ae->ack, __LINE__);
16605 #ifdef TCP_ACCOUNTING
16606 		/* Count for the specific type of ack in */
16607 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16608 			tp->tcp_cnt_counters[ae->ack_val_set]++;
16609 		}
16610 #endif
16611 		/*
16612 		 * Note how we could move up these in the determination
16613 		 * above, but we don't so that way the timestamp checks (and ECN)
16614 		 * is done first before we do any processing on the ACK.
16615 		 * The non-compressed path through the code has this
16616 		 * weakness (noted by @jtl) that it actually does some
16617 		 * processing before verifying the timestamp information.
16618 		 * We don't take that path here which is why we set
16619 		 * the ack_val_set first, do the timestamp and ecn
16620 		 * processing, and then look at what we have setup.
16621 		 */
16622 		if (ae->ack_val_set == ACK_BEHIND) {
16623 			/*
16624 			 * Case B flag reordering, if window is not closed
16625 			 * or it could be a keep-alive or persists
16626 			 */
16627 			if (SEQ_LT(ae->ack, tp->snd_una) && (sbspace(&so->so_rcv) > segsiz)) {
16628 				rack->r_ctl.rc_reorder_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
16629 				if (rack->r_ctl.rc_reorder_ts == 0)
16630 					rack->r_ctl.rc_reorder_ts = 1;
16631 			}
16632 		} else if (ae->ack_val_set == ACK_DUPACK) {
16633 			/* Case D */
16634 			rack_strike_dupack(rack, ae->ack);
16635 		} else if (ae->ack_val_set == ACK_RWND) {
16636 			/* Case C */
16637 			if ((ae->flags & TSTMP_LRO) || (ae->flags & TSTMP_HDWR)) {
16638 				ts.tv_sec = ae->timestamp / 1000000000;
16639 				ts.tv_nsec = ae->timestamp % 1000000000;
16640 				rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
16641 				rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
16642 			} else {
16643 				rack->r_ctl.act_rcv_time = *tv;
16644 			}
16645 			if (rack->forced_ack) {
16646 				rack_handle_probe_response(rack, tiwin,
16647 							   tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time));
16648 			}
16649 #ifdef TCP_ACCOUNTING
16650 			win_up_req = 1;
16651 #endif
16652 			win_upd_ack = ae->ack;
16653 			win_seq = ae->seq;
16654 			the_win = tiwin;
16655 			rack_do_win_updates(tp, rack, the_win, win_seq, win_upd_ack, cts);
16656 		} else {
16657 			/* Case A */
16658 			if (SEQ_GT(ae->ack, tp->snd_max)) {
16659 				/*
16660 				 * We just send an ack since the incoming
16661 				 * ack is beyond the largest seq we sent.
16662 				 */
16663 				if ((tp->t_flags & TF_ACKNOW) == 0) {
16664 					ctf_ack_war_checks(tp, &rack->r_ctl.challenge_ack_ts, &rack->r_ctl.challenge_ack_cnt);
16665 					if (tp->t_flags && TF_ACKNOW)
16666 						rack->r_wanted_output = 1;
16667 				}
16668 			} else {
16669 				nsegs++;
16670 				/* If the window changed setup to update */
16671 				if (tiwin != tp->snd_wnd) {
16672 					win_upd_ack = ae->ack;
16673 					win_seq = ae->seq;
16674 					the_win = tiwin;
16675 					rack_do_win_updates(tp, rack, the_win, win_seq, win_upd_ack, cts);
16676 				}
16677 #ifdef TCP_ACCOUNTING
16678 				/* Account for the acks */
16679 				if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16680 					tp->tcp_cnt_counters[CNT_OF_ACKS_IN] += (((ae->ack - high_seq) + segsiz - 1) / segsiz);
16681 				}
16682 #endif
16683 				high_seq = ae->ack;
16684 				/* Setup our act_rcv_time */
16685 				if ((ae->flags & TSTMP_LRO) || (ae->flags & TSTMP_HDWR)) {
16686 					ts.tv_sec = ae->timestamp / 1000000000;
16687 					ts.tv_nsec = ae->timestamp % 1000000000;
16688 					rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
16689 					rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
16690 				} else {
16691 					rack->r_ctl.act_rcv_time = *tv;
16692 				}
16693 				rack_process_to_cumack(tp, rack, ae->ack, cts, to,
16694 						       tcp_tv_to_lusectick(&rack->r_ctl.act_rcv_time));
16695 #ifdef TCP_REQUEST_TRK
16696 				rack_req_check_for_comp(rack, high_seq);
16697 #endif
16698 				if (rack->rc_dsack_round_seen) {
16699 					/* Is the dsack round over? */
16700 					if (SEQ_GEQ(ae->ack, rack->r_ctl.dsack_round_end)) {
16701 						/* Yes it is */
16702 						rack->rc_dsack_round_seen = 0;
16703 						rack_log_dsack_event(rack, 3, __LINE__, 0, 0);
16704 					}
16705 				}
16706 			}
16707 		}
16708 		/* And lets be sure to commit the rtt measurements for this ack */
16709 		tcp_rack_xmit_timer_commit(rack, tp);
16710 #ifdef TCP_ACCOUNTING
16711 		rdstc = get_cyclecount();
16712 		if (rdstc > ts_val) {
16713 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16714 				tp->tcp_proc_time[ae->ack_val_set] += (rdstc - ts_val);
16715 				if (ae->ack_val_set == ACK_CUMACK)
16716 					tp->tcp_proc_time[CYC_HANDLE_MAP] += (rdstc - ts_val);
16717 			}
16718 		}
16719 #endif
16720 	}
16721 #ifdef TCP_ACCOUNTING
16722 	ts_val = get_cyclecount();
16723 #endif
16724 	/* Tend to any collapsed window */
16725 	if (SEQ_GT(tp->snd_max, high_seq) && (tp->snd_wnd < (tp->snd_max - high_seq))) {
16726 		/* The peer collapsed the window */
16727 		rack_collapsed_window(rack, (tp->snd_max - high_seq), high_seq, __LINE__);
16728 	} else if (rack->rc_has_collapsed)
16729 		rack_un_collapse_window(rack, __LINE__);
16730 	if ((rack->r_collapse_point_valid) &&
16731 	    (SEQ_GT(high_seq, rack->r_ctl.high_collapse_point)))
16732 		rack->r_collapse_point_valid = 0;
16733 	acked_amount = acked = (high_seq - tp->snd_una);
16734 	if (acked) {
16735 		/*
16736 		 * The draft (v3) calls for us to use SEQ_GEQ, but that
16737 		 * causes issues when we are just going app limited. Lets
16738 		 * instead use SEQ_GT <or> where its equal but more data
16739 		 * is outstanding.
16740 		 *
16741 		 * Also make sure we are on the last ack of a series. We
16742 		 * have to have all the ack's processed in queue to know
16743 		 * if there is something left outstanding.
16744 		 *
16745 		 */
16746 		if (SEQ_GEQ(high_seq, rack->r_ctl.roundends) &&
16747 		    (rack->rc_new_rnd_needed == 0) &&
16748 		    (nxt_pkt == 0)) {
16749 			/*
16750 			 * We have crossed into a new round with
16751 			 * this th_ack value.
16752 			 */
16753 			rack_new_round_setup(tp, rack, high_seq);
16754 		}
16755 		/*
16756 		 * Clear the probe not answered flag
16757 		 * since cum-ack moved forward.
16758 		 */
16759 		rack->probe_not_answered = 0;
16760 		if (tp->t_flags & TF_NEEDSYN) {
16761 			/*
16762 			 * T/TCP: Connection was half-synchronized, and our SYN has
16763 			 * been ACK'd (so connection is now fully synchronized).  Go
16764 			 * to non-starred state, increment snd_una for ACK of SYN,
16765 			 * and check if we can do window scaling.
16766 			 */
16767 			tp->t_flags &= ~TF_NEEDSYN;
16768 			tp->snd_una++;
16769 			acked_amount = acked = (high_seq - tp->snd_una);
16770 		}
16771 		if (acked > sbavail(&so->so_snd))
16772 			acked_amount = sbavail(&so->so_snd);
16773 		if (IN_FASTRECOVERY(tp->t_flags) &&
16774 		    (rack->rack_no_prr == 0))
16775 			rack_update_prr(tp, rack, acked_amount, high_seq);
16776 		if (IN_RECOVERY(tp->t_flags)) {
16777 			if (SEQ_LT(high_seq, tp->snd_recover) &&
16778 			    (SEQ_LT(high_seq, tp->snd_max))) {
16779 				tcp_rack_partialack(tp);
16780 			} else {
16781 				rack_post_recovery(tp, high_seq);
16782 				post_recovery = 1;
16783 			}
16784 		}  else if ((rack->rto_from_rec == 1) &&
16785 			    SEQ_GEQ(high_seq, tp->snd_recover)) {
16786 			/*
16787 			 * We were in recovery, hit a rxt timeout
16788 			 * and never re-entered recovery. The timeout(s)
16789 			 * made up all the lost data. In such a case
16790 			 * we need to clear the rto_from_rec flag.
16791 			 */
16792 			rack->rto_from_rec = 0;
16793 		}
16794 		/* Handle the rack-log-ack part (sendmap) */
16795 		if ((sbused(&so->so_snd) == 0) &&
16796 		    (acked > acked_amount) &&
16797 		    (tp->t_state >= TCPS_FIN_WAIT_1) &&
16798 		    (tp->t_flags & TF_SENTFIN)) {
16799 			/*
16800 			 * We must be sure our fin
16801 			 * was sent and acked (we can be
16802 			 * in FIN_WAIT_1 without having
16803 			 * sent the fin).
16804 			 */
16805 			ourfinisacked = 1;
16806 			/*
16807 			 * Lets make sure snd_una is updated
16808 			 * since most likely acked_amount = 0 (it
16809 			 * should be).
16810 			 */
16811 			tp->snd_una = high_seq;
16812 		}
16813 		/* Did we make a RTO error? */
16814 		if ((tp->t_flags & TF_PREVVALID) &&
16815 		    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
16816 			tp->t_flags &= ~TF_PREVVALID;
16817 			if (tp->t_rxtshift == 1 &&
16818 			    (int)(ticks - tp->t_badrxtwin) < 0)
16819 				rack_cong_signal(tp, CC_RTO_ERR, high_seq, __LINE__);
16820 		}
16821 		/* Handle the data in the socket buffer */
16822 		KMOD_TCPSTAT_ADD(tcps_rcvackpack, 1);
16823 		KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
16824 		if (acked_amount > 0) {
16825 			uint32_t p_cwnd;
16826 			struct mbuf *mfree;
16827 
16828 			if (post_recovery) {
16829 				/*
16830 				 * Grab the segsiz, multiply by 2 and add the snd_cwnd
16831 				 * that is the max the CC should add if we are exiting
16832 				 * recovery and doing a late add.
16833 				 */
16834 				p_cwnd = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
16835 				p_cwnd <<= 1;
16836 				p_cwnd += tp->snd_cwnd;
16837 			}
16838 			rack_ack_received(tp, rack, high_seq, nsegs, CC_ACK, post_recovery);
16839 			if (post_recovery && (tp->snd_cwnd > p_cwnd)) {
16840 				/* Must be non-newreno (cubic) getting too ahead of itself */
16841 				tp->snd_cwnd = p_cwnd;
16842 			}
16843 			SOCKBUF_LOCK(&so->so_snd);
16844 			mfree = sbcut_locked(&so->so_snd, acked_amount);
16845 			tp->snd_una = high_seq;
16846 			/* Note we want to hold the sb lock through the sendmap adjust */
16847 			rack_adjust_sendmap_head(rack, &so->so_snd);
16848 			/* Wake up the socket if we have room to write more */
16849 			rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
16850 			sowwakeup_locked(so);
16851 			m_freem(mfree);
16852 		}
16853 		/* update progress */
16854 		tp->t_acktime = ticks;
16855 		rack_log_progress_event(rack, tp, tp->t_acktime,
16856 					PROGRESS_UPDATE, __LINE__);
16857 		/* Clear out shifts and such */
16858 		tp->t_rxtshift = 0;
16859 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
16860 				   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
16861 		rack->rc_tlp_in_progress = 0;
16862 		rack->r_ctl.rc_tlp_cnt_out = 0;
16863 		/* Send recover and snd_nxt must be dragged along */
16864 		if (SEQ_GT(tp->snd_una, tp->snd_recover))
16865 			tp->snd_recover = tp->snd_una;
16866 		if (SEQ_LT(tp->snd_nxt, tp->snd_max))
16867 			tp->snd_nxt = tp->snd_max;
16868 		/*
16869 		 * If the RXT timer is running we want to
16870 		 * stop it, so we can restart a TLP (or new RXT).
16871 		 */
16872 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
16873 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
16874 		tp->snd_wl2 = high_seq;
16875 		tp->t_dupacks = 0;
16876 		if (under_pacing &&
16877 		    (rack->use_fixed_rate == 0) &&
16878 		    (rack->in_probe_rtt == 0) &&
16879 		    rack->rc_gp_dyn_mul &&
16880 		    rack->rc_always_pace) {
16881 			/* Check if we are dragging bottom */
16882 			rack_check_bottom_drag(tp, rack, so);
16883 		}
16884 		if (tp->snd_una == tp->snd_max) {
16885 			tp->t_flags &= ~TF_PREVVALID;
16886 			rack->r_ctl.retran_during_recovery = 0;
16887 			rack->rc_suspicious = 0;
16888 			rack->r_ctl.dsack_byte_cnt = 0;
16889 			rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
16890 			if (rack->r_ctl.rc_went_idle_time == 0)
16891 				rack->r_ctl.rc_went_idle_time = 1;
16892 			rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
16893 			if (sbavail(&tptosocket(tp)->so_snd) == 0)
16894 				tp->t_acktime = 0;
16895 			/* Set so we might enter persists... */
16896 			rack->r_wanted_output = 1;
16897 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
16898 			sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
16899 			if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
16900 			    (sbavail(&so->so_snd) == 0) &&
16901 			    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
16902 				/*
16903 				 * The socket was gone and the
16904 				 * peer sent data (not now in the past), time to
16905 				 * reset him.
16906 				 */
16907 				rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
16908 				/* tcp_close will kill the inp pre-log the Reset */
16909 				tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
16910 #ifdef TCP_ACCOUNTING
16911 				rdstc = get_cyclecount();
16912 				if (rdstc > ts_val) {
16913 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16914 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16915 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16916 					}
16917 				}
16918 #endif
16919 				m_freem(m);
16920 				tp = tcp_close(tp);
16921 				if (tp == NULL) {
16922 #ifdef TCP_ACCOUNTING
16923 					sched_unpin();
16924 #endif
16925 					return (1);
16926 				}
16927 				/*
16928 				 * We would normally do drop-with-reset which would
16929 				 * send back a reset. We can't since we don't have
16930 				 * all the needed bits. Instead lets arrange for
16931 				 * a call to tcp_output(). That way since we
16932 				 * are in the closed state we will generate a reset.
16933 				 *
16934 				 * Note if tcp_accounting is on we don't unpin since
16935 				 * we do that after the goto label.
16936 				 */
16937 				goto send_out_a_rst;
16938 			}
16939 			if ((sbused(&so->so_snd) == 0) &&
16940 			    (tp->t_state >= TCPS_FIN_WAIT_1) &&
16941 			    (tp->t_flags & TF_SENTFIN)) {
16942 				/*
16943 				 * If we can't receive any more data, then closing user can
16944 				 * proceed. Starting the timer is contrary to the
16945 				 * specification, but if we don't get a FIN we'll hang
16946 				 * forever.
16947 				 *
16948 				 */
16949 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
16950 					soisdisconnected(so);
16951 					tcp_timer_activate(tp, TT_2MSL,
16952 							   (tcp_fast_finwait2_recycle ?
16953 							    tcp_finwait2_timeout :
16954 							    TP_MAXIDLE(tp)));
16955 				}
16956 				if (ourfinisacked == 0) {
16957 					/*
16958 					 * We don't change to fin-wait-2 if we have our fin acked
16959 					 * which means we are probably in TCPS_CLOSING.
16960 					 */
16961 					tcp_state_change(tp, TCPS_FIN_WAIT_2);
16962 				}
16963 			}
16964 		}
16965 		/* Wake up the socket if we have room to write more */
16966 		if (sbavail(&so->so_snd)) {
16967 			rack->r_wanted_output = 1;
16968 			if (ctf_progress_timeout_check(tp, true)) {
16969 				rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
16970 							tp, tick, PROGRESS_DROP, __LINE__);
16971 				/*
16972 				 * We cheat here and don't send a RST, we should send one
16973 				 * when the pacer drops the connection.
16974 				 */
16975 #ifdef TCP_ACCOUNTING
16976 				rdstc = get_cyclecount();
16977 				if (rdstc > ts_val) {
16978 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16979 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16980 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16981 					}
16982 				}
16983 				sched_unpin();
16984 #endif
16985 				(void)tcp_drop(tp, ETIMEDOUT);
16986 				m_freem(m);
16987 				return (1);
16988 			}
16989 		}
16990 		if (ourfinisacked) {
16991 			switch(tp->t_state) {
16992 			case TCPS_CLOSING:
16993 #ifdef TCP_ACCOUNTING
16994 				rdstc = get_cyclecount();
16995 				if (rdstc > ts_val) {
16996 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16997 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16998 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16999 					}
17000 				}
17001 				sched_unpin();
17002 #endif
17003 				tcp_twstart(tp);
17004 				m_freem(m);
17005 				return (1);
17006 				break;
17007 			case TCPS_LAST_ACK:
17008 #ifdef TCP_ACCOUNTING
17009 				rdstc = get_cyclecount();
17010 				if (rdstc > ts_val) {
17011 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17012 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
17013 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
17014 					}
17015 				}
17016 				sched_unpin();
17017 #endif
17018 				tp = tcp_close(tp);
17019 				ctf_do_drop(m, tp);
17020 				return (1);
17021 				break;
17022 			case TCPS_FIN_WAIT_1:
17023 #ifdef TCP_ACCOUNTING
17024 				rdstc = get_cyclecount();
17025 				if (rdstc > ts_val) {
17026 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17027 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
17028 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
17029 					}
17030 				}
17031 #endif
17032 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
17033 					soisdisconnected(so);
17034 					tcp_timer_activate(tp, TT_2MSL,
17035 							   (tcp_fast_finwait2_recycle ?
17036 							    tcp_finwait2_timeout :
17037 							    TP_MAXIDLE(tp)));
17038 				}
17039 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
17040 				break;
17041 			default:
17042 				break;
17043 			}
17044 		}
17045 		if (rack->r_fast_output) {
17046 			/*
17047 			 * We re doing fast output.. can we expand that?
17048 			 */
17049 			rack_gain_for_fastoutput(rack, tp, so, acked_amount);
17050 		}
17051 #ifdef TCP_ACCOUNTING
17052 		rdstc = get_cyclecount();
17053 		if (rdstc > ts_val) {
17054 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17055 				tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
17056 				tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
17057 			}
17058 		}
17059 
17060 	} else if (win_up_req) {
17061 		rdstc = get_cyclecount();
17062 		if (rdstc > ts_val) {
17063 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17064 				tp->tcp_proc_time[ACK_RWND] += (rdstc - ts_val);
17065 			}
17066 		}
17067 #endif
17068 	}
17069 	/* Now is there a next packet, if so we are done */
17070 	m_freem(m);
17071 	did_out = 0;
17072 	if (nxt_pkt) {
17073 #ifdef TCP_ACCOUNTING
17074 		sched_unpin();
17075 #endif
17076 		rack_log_doseg_done(rack, cts, nxt_pkt, did_out, 5, nsegs);
17077 		return (0);
17078 	}
17079 	rack_handle_might_revert(tp, rack);
17080 	ctf_calc_rwin(so, tp);
17081 	if ((rack->r_wanted_output != 0) ||
17082 	    (rack->r_fast_output != 0) ||
17083 	    (tp->t_flags & TF_ACKNOW )) {
17084 	send_out_a_rst:
17085 		if (tcp_output(tp) < 0) {
17086 #ifdef TCP_ACCOUNTING
17087 			sched_unpin();
17088 #endif
17089 			return (1);
17090 		}
17091 		did_out = 1;
17092 	}
17093 	if (tp->t_flags2 & TF2_HPTS_CALLS)
17094 		tp->t_flags2 &= ~TF2_HPTS_CALLS;
17095 	rack_free_trim(rack);
17096 #ifdef TCP_ACCOUNTING
17097 	sched_unpin();
17098 #endif
17099 	rack_timer_audit(tp, rack, &so->so_snd);
17100 	rack_log_doseg_done(rack, cts, nxt_pkt, did_out, 6, nsegs);
17101 	return (0);
17102 }
17103 
17104 #define	TCP_LRO_TS_OPTION \
17105     ntohl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | \
17106 	  (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP)
17107 
17108 static int
rack_do_segment_nounlock(struct tcpcb * tp,struct mbuf * m,struct tcphdr * th,int32_t drop_hdrlen,int32_t tlen,uint8_t iptos,int32_t nxt_pkt,struct timeval * tv)17109 rack_do_segment_nounlock(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
17110     int32_t drop_hdrlen, int32_t tlen, uint8_t iptos, int32_t nxt_pkt,
17111     struct timeval *tv)
17112 {
17113 	struct inpcb *inp = tptoinpcb(tp);
17114 	struct socket *so = tptosocket(tp);
17115 #ifdef TCP_ACCOUNTING
17116 	uint64_t ts_val;
17117 #endif
17118 	int32_t thflags, retval, did_out = 0;
17119 	int32_t way_out = 0;
17120 	/*
17121 	 * cts - is the current time from tv (caller gets ts) in microseconds.
17122 	 * ms_cts - is the current time from tv in milliseconds.
17123 	 * us_cts - is the time that LRO or hardware actually got the packet in microseconds.
17124 	 */
17125 	uint32_t cts, us_cts, ms_cts;
17126 	uint32_t tiwin;
17127 	struct timespec ts;
17128 	struct tcpopt to;
17129 	struct tcp_rack *rack;
17130 	struct rack_sendmap *rsm;
17131 	int32_t prev_state = 0;
17132 	int no_output = 0;
17133 	int slot_remaining = 0;
17134 #ifdef TCP_ACCOUNTING
17135 	int ack_val_set = 0xf;
17136 #endif
17137 	int nsegs;
17138 
17139 	NET_EPOCH_ASSERT();
17140 	INP_WLOCK_ASSERT(inp);
17141 
17142 	/*
17143 	 * tv passed from common code is from either M_TSTMP_LRO or
17144 	 * tcp_get_usecs() if no LRO m_pkthdr timestamp is present.
17145 	 */
17146 	rack = (struct tcp_rack *)tp->t_fb_ptr;
17147 	if (rack->rack_deferred_inited == 0) {
17148 		/*
17149 		 * If we are the connecting socket we will
17150 		 * hit rack_init() when no sequence numbers
17151 		 * are setup. This makes it so we must defer
17152 		 * some initialization. Call that now.
17153 		 */
17154 		rack_deferred_init(tp, rack);
17155 	}
17156 	/*
17157 	 * Check to see if we need to skip any output plans. This
17158 	 * can happen in the non-LRO path where we are pacing and
17159 	 * must process the ack coming in but need to defer sending
17160 	 * anything becase a pacing timer is running.
17161 	 */
17162 	us_cts = tcp_tv_to_usectick(tv);
17163 	if (m->m_flags & M_ACKCMP) {
17164 		/*
17165 		 * All compressed ack's are ack's by definition so
17166 		 * remove any ack required flag and then do the processing.
17167 		 */
17168 		rack->rc_ack_required = 0;
17169 		return (rack_do_compressed_ack_processing(tp, so, m, nxt_pkt, tv));
17170 	}
17171 	thflags = tcp_get_flags(th);
17172 	if ((rack->rc_always_pace == 1) &&
17173 	    (rack->rc_ack_can_sendout_data == 0) &&
17174 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
17175 	    (TSTMP_LT(us_cts, rack->r_ctl.rc_last_output_to))) {
17176 		/*
17177 		 * Ok conditions are right for queuing the packets
17178 		 * but we do have to check the flags in the inp, it
17179 		 * could be, if a sack is present, we want to be awoken and
17180 		 * so should process the packets.
17181 		 */
17182 		slot_remaining = rack->r_ctl.rc_last_output_to - us_cts;
17183 		if (rack->rc_tp->t_flags2 & TF2_DONT_SACK_QUEUE) {
17184 			no_output = 1;
17185 		} else {
17186 			/*
17187 			 * If there is no options, or just a
17188 			 * timestamp option, we will want to queue
17189 			 * the packets. This is the same that LRO does
17190 			 * and will need to change with accurate ECN.
17191 			 */
17192 			uint32_t *ts_ptr;
17193 			int optlen;
17194 
17195 			optlen = (th->th_off << 2) - sizeof(struct tcphdr);
17196 			ts_ptr = (uint32_t *)(th + 1);
17197 			if ((optlen == 0) ||
17198 			    ((optlen == TCPOLEN_TSTAMP_APPA) &&
17199 			     (*ts_ptr == TCP_LRO_TS_OPTION)))
17200 				no_output = 1;
17201 		}
17202 		if ((no_output == 1) && (slot_remaining < tcp_min_hptsi_time)) {
17203 			/*
17204 			 * It is unrealistic to think we can pace in less than
17205 			 * the minimum granularity of the pacer (def:250usec). So
17206 			 * if we have less than that time remaining we should go
17207 			 * ahead and allow output to be "early". We will attempt to
17208 			 * make up for it in any pacing time we try to apply on
17209 			 * the outbound packet.
17210 			 */
17211 			no_output = 0;
17212 		}
17213 	}
17214 	/*
17215 	 * If there is a RST or FIN lets dump out the bw
17216 	 * with a FIN the connection may go on but we
17217 	 * may not.
17218 	 */
17219 	if ((thflags & TH_FIN) || (thflags & TH_RST))
17220 		rack_log_pacing_delay_calc(rack,
17221 					   rack->r_ctl.gp_bw,
17222 					   0,
17223 					   0,
17224 					   rack_get_gp_est(rack), /* delRate */
17225 					   rack_get_lt_bw(rack), /* rttProp */
17226 					   20, __LINE__, NULL, 0);
17227 	if (m->m_flags & M_ACKCMP) {
17228 		panic("Impossible reach m has ackcmp? m:%p tp:%p", m, tp);
17229 	}
17230 	cts = tcp_tv_to_usectick(tv);
17231 	ms_cts =  tcp_tv_to_mssectick(tv);
17232 	nsegs = m->m_pkthdr.lro_nsegs;
17233 	counter_u64_add(rack_proc_non_comp_ack, 1);
17234 #ifdef TCP_ACCOUNTING
17235 	sched_pin();
17236 	if (thflags & TH_ACK)
17237 		ts_val = get_cyclecount();
17238 #endif
17239 	if ((m->m_flags & M_TSTMP) ||
17240 	    (m->m_flags & M_TSTMP_LRO)) {
17241 		mbuf_tstmp2timespec(m, &ts);
17242 		rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
17243 		rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
17244 	} else
17245 		rack->r_ctl.act_rcv_time = *tv;
17246 	kern_prefetch(rack, &prev_state);
17247 	prev_state = 0;
17248 	/*
17249 	 * Unscale the window into a 32-bit value. For the SYN_SENT state
17250 	 * the scale is zero.
17251 	 */
17252 	tiwin = th->th_win << tp->snd_scale;
17253 #ifdef TCP_ACCOUNTING
17254 	if (thflags & TH_ACK) {
17255 		/*
17256 		 * We have a tradeoff here. We can either do what we are
17257 		 * doing i.e. pinning to this CPU and then doing the accounting
17258 		 * <or> we could do a critical enter, setup the rdtsc and cpu
17259 		 * as in below, and then validate we are on the same CPU on
17260 		 * exit. I have choosen to not do the critical enter since
17261 		 * that often will gain you a context switch, and instead lock
17262 		 * us (line above this if) to the same CPU with sched_pin(). This
17263 		 * means we may be context switched out for a higher priority
17264 		 * interupt but we won't be moved to another CPU.
17265 		 *
17266 		 * If this occurs (which it won't very often since we most likely
17267 		 * are running this code in interupt context and only a higher
17268 		 * priority will bump us ... clock?) we will falsely add in
17269 		 * to the time the interupt processing time plus the ack processing
17270 		 * time. This is ok since its a rare event.
17271 		 */
17272 		ack_val_set = tcp_do_ack_accounting(tp, th, &to, tiwin,
17273 						    ctf_fixed_maxseg(tp));
17274 	}
17275 #endif
17276 	/*
17277 	 * Parse options on any incoming segment.
17278 	 */
17279 	memset(&to, 0, sizeof(to));
17280 	tcp_dooptions(&to, (u_char *)(th + 1),
17281 	    (th->th_off << 2) - sizeof(struct tcphdr),
17282 	    (thflags & TH_SYN) ? TO_SYN : 0);
17283 	KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN",
17284 	    __func__));
17285 	KASSERT(tp->t_state != TCPS_TIME_WAIT, ("%s: TCPS_TIME_WAIT",
17286 	    __func__));
17287 	if (tp->t_flags2 & TF2_PROC_SACK_PROHIBIT) {
17288 		/*
17289 		 * We don't look at sack's from the
17290 		 * peer because the MSS is too small which
17291 		 * can subject us to an attack.
17292 		 */
17293 		to.to_flags &= ~TOF_SACK;
17294 	}
17295 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
17296 	    (tp->t_flags & TF_GPUTINPROG)) {
17297 		/*
17298 		 * We have a goodput in progress
17299 		 * and we have entered a late state.
17300 		 * Do we have enough data in the sb
17301 		 * to handle the GPUT request?
17302 		 */
17303 		uint32_t bytes;
17304 
17305 		bytes = tp->gput_ack - tp->gput_seq;
17306 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
17307 			bytes += tp->gput_seq - tp->snd_una;
17308 		if (bytes > sbavail(&tptosocket(tp)->so_snd)) {
17309 			/*
17310 			 * There are not enough bytes in the socket
17311 			 * buffer that have been sent to cover this
17312 			 * measurement. Cancel it.
17313 			 */
17314 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
17315 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
17316 						   tp->gput_seq,
17317 						   0, 0, 18, __LINE__, NULL, 0);
17318 			tp->t_flags &= ~TF_GPUTINPROG;
17319 		}
17320 	}
17321 	if (tcp_bblogging_on(rack->rc_tp)) {
17322 		union tcp_log_stackspecific log;
17323 		struct timeval ltv;
17324 #ifdef TCP_REQUEST_TRK
17325 		struct tcp_sendfile_track *tcp_req;
17326 
17327 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
17328 			tcp_req = tcp_req_find_req_for_seq(tp, (th->th_ack-1));
17329 		} else {
17330 			tcp_req = tcp_req_find_req_for_seq(tp, th->th_ack);
17331 		}
17332 #endif
17333 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
17334 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
17335 		if (rack->rack_no_prr == 0)
17336 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
17337 		else
17338 			log.u_bbr.flex1 = 0;
17339 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
17340 		log.u_bbr.use_lt_bw <<= 1;
17341 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
17342 		log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
17343 		log.u_bbr.bbr_state = rack->rc_free_cnt;
17344 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
17345 		log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
17346 		log.u_bbr.flex3 = m->m_flags;
17347 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
17348 		log.u_bbr.lost = thflags;
17349 		log.u_bbr.pacing_gain = 0x1;
17350 #ifdef TCP_ACCOUNTING
17351 		log.u_bbr.cwnd_gain = ack_val_set;
17352 #endif
17353 		log.u_bbr.flex7 = 2;
17354 		if (m->m_flags & M_TSTMP) {
17355 			/* Record the hardware timestamp if present */
17356 			mbuf_tstmp2timespec(m, &ts);
17357 			ltv.tv_sec = ts.tv_sec;
17358 			ltv.tv_usec = ts.tv_nsec / 1000;
17359 			log.u_bbr.lt_epoch = tcp_tv_to_usectick(&ltv);
17360 		} else if (m->m_flags & M_TSTMP_LRO) {
17361 			/* Record the LRO the arrival timestamp */
17362 			mbuf_tstmp2timespec(m, &ts);
17363 			ltv.tv_sec = ts.tv_sec;
17364 			ltv.tv_usec = ts.tv_nsec / 1000;
17365 			log.u_bbr.flex5 = tcp_tv_to_usectick(&ltv);
17366 		}
17367 		log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
17368 		/* Log the rcv time */
17369 		log.u_bbr.delRate = m->m_pkthdr.rcv_tstmp;
17370 #ifdef TCP_REQUEST_TRK
17371 		log.u_bbr.applimited = tp->t_tcpreq_closed;
17372 		log.u_bbr.applimited <<= 8;
17373 		log.u_bbr.applimited |= tp->t_tcpreq_open;
17374 		log.u_bbr.applimited <<= 8;
17375 		log.u_bbr.applimited |= tp->t_tcpreq_req;
17376 		if (tcp_req) {
17377 			/* Copy out any client req info */
17378 			/* seconds */
17379 			log.u_bbr.pkt_epoch = (tcp_req->localtime / HPTS_USEC_IN_SEC);
17380 			/* useconds */
17381 			log.u_bbr.delivered = (tcp_req->localtime % HPTS_USEC_IN_SEC);
17382 			log.u_bbr.rttProp = tcp_req->timestamp;
17383 			log.u_bbr.cur_del_rate = tcp_req->start;
17384 			if (tcp_req->flags & TCP_TRK_TRACK_FLG_OPEN) {
17385 				log.u_bbr.flex8 |= 1;
17386 			} else {
17387 				log.u_bbr.flex8 |= 2;
17388 				log.u_bbr.bw_inuse = tcp_req->end;
17389 			}
17390 			log.u_bbr.flex6 = tcp_req->start_seq;
17391 			if (tcp_req->flags & TCP_TRK_TRACK_FLG_COMP) {
17392 				log.u_bbr.flex8 |= 4;
17393 				log.u_bbr.epoch = tcp_req->end_seq;
17394 			}
17395 		}
17396 #endif
17397 		TCP_LOG_EVENTP(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_IN, 0,
17398 		    tlen, &log, true, &ltv);
17399 	}
17400 	/* Remove ack required flag if set, we have one  */
17401 	if (thflags & TH_ACK)
17402 		rack->rc_ack_required = 0;
17403 	rack_log_type_bbrsnd(rack, 0, 0, cts, tv, __LINE__);
17404 	if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) {
17405 		way_out = 4;
17406 		retval = 0;
17407 		m_freem(m);
17408 		goto done_with_input;
17409 	}
17410 	/*
17411 	 * If a segment with the ACK-bit set arrives in the SYN-SENT state
17412 	 * check SEQ.ACK first as described on page 66 of RFC 793, section 3.9.
17413 	 */
17414 	if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) &&
17415 	    (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) {
17416 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
17417 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
17418 #ifdef TCP_ACCOUNTING
17419 		sched_unpin();
17420 #endif
17421 		return (1);
17422 	}
17423 	/*
17424 	 * If timestamps were negotiated during SYN/ACK and a
17425 	 * segment without a timestamp is received, silently drop
17426 	 * the segment, unless it is a RST segment or missing timestamps are
17427 	 * tolerated.
17428 	 * See section 3.2 of RFC 7323.
17429 	 */
17430 	if ((tp->t_flags & TF_RCVD_TSTMP) && !(to.to_flags & TOF_TS) &&
17431 	    ((thflags & TH_RST) == 0) && (V_tcp_tolerate_missing_ts == 0)) {
17432 		way_out = 5;
17433 		retval = 0;
17434 		m_freem(m);
17435 		goto done_with_input;
17436 	}
17437 	/*
17438 	 * Segment received on connection. Reset idle time and keep-alive
17439 	 * timer. XXX: This should be done after segment validation to
17440 	 * ignore broken/spoofed segs.
17441 	 */
17442 	if  (tp->t_idle_reduce &&
17443 	     (tp->snd_max == tp->snd_una) &&
17444 	     (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
17445 		counter_u64_add(rack_input_idle_reduces, 1);
17446 		rack_cc_after_idle(rack, tp);
17447 	}
17448 	tp->t_rcvtime = ticks;
17449 #ifdef STATS
17450 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_FRWIN, tiwin);
17451 #endif
17452 	if (tiwin > rack->r_ctl.rc_high_rwnd)
17453 		rack->r_ctl.rc_high_rwnd = tiwin;
17454 	/*
17455 	 * TCP ECN processing. XXXJTL: If we ever use ECN, we need to move
17456 	 * this to occur after we've validated the segment.
17457 	 */
17458 	if (tcp_ecn_input_segment(tp, thflags, tlen,
17459 	    tcp_packets_this_ack(tp, th->th_ack),
17460 	    iptos))
17461 		rack_cong_signal(tp, CC_ECN, th->th_ack, __LINE__);
17462 
17463 	/*
17464 	 * If echoed timestamp is later than the current time, fall back to
17465 	 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
17466 	 * were used when this connection was established.
17467 	 */
17468 	if ((to.to_flags & TOF_TS) && (to.to_tsecr != 0)) {
17469 		to.to_tsecr -= tp->ts_offset;
17470 		if (TSTMP_GT(to.to_tsecr, ms_cts))
17471 			to.to_tsecr = 0;
17472 	}
17473 	if ((rack->r_rcvpath_rtt_up == 1) &&
17474 	    (to.to_flags & TOF_TS) &&
17475 	    (TSTMP_GEQ(to.to_tsecr, rack->r_ctl.last_rcv_tstmp_for_rtt))) {
17476 		uint32_t rtt = 0;
17477 
17478 		/*
17479 		 * We are receiving only and thus not sending
17480 		 * data to do an RTT. We set a flag when we first
17481 		 * sent this TS to the peer. We now have it back
17482 		 * and have an RTT to share. We log it as a conf
17483 		 * 4, we are not so sure about it.. since we
17484 		 * may have lost an ack.
17485 		 */
17486 		if (TSTMP_GT(cts, rack->r_ctl.last_time_of_arm_rcv))
17487 		    rtt = (cts - rack->r_ctl.last_time_of_arm_rcv);
17488 		rack->r_rcvpath_rtt_up = 0;
17489 		/* Submit and commit the timer */
17490 		if (rtt > 0) {
17491 			tcp_rack_xmit_timer(rack, rtt, 0, rtt, 4, NULL, 1);
17492 			tcp_rack_xmit_timer_commit(rack, tp);
17493 		}
17494 	}
17495 	/*
17496 	 * If its the first time in we need to take care of options and
17497 	 * verify we can do SACK for rack!
17498 	 */
17499 	if (rack->r_state == 0) {
17500 		/* Should be init'd by rack_init() */
17501 		KASSERT(rack->rc_inp != NULL,
17502 		    ("%s: rack->rc_inp unexpectedly NULL", __func__));
17503 		if (rack->rc_inp == NULL) {
17504 			rack->rc_inp = inp;
17505 		}
17506 
17507 		/*
17508 		 * Process options only when we get SYN/ACK back. The SYN
17509 		 * case for incoming connections is handled in tcp_syncache.
17510 		 * According to RFC1323 the window field in a SYN (i.e., a
17511 		 * <SYN> or <SYN,ACK>) segment itself is never scaled. XXX
17512 		 * this is traditional behavior, may need to be cleaned up.
17513 		 */
17514 		if (tp->t_state == TCPS_SYN_SENT && (thflags & TH_SYN)) {
17515 			/* Handle parallel SYN for ECN */
17516 			tcp_ecn_input_parallel_syn(tp, thflags, iptos);
17517 			if ((to.to_flags & TOF_SCALE) &&
17518 			    (tp->t_flags & TF_REQ_SCALE)) {
17519 				tp->t_flags |= TF_RCVD_SCALE;
17520 				tp->snd_scale = to.to_wscale;
17521 			} else
17522 				tp->t_flags &= ~TF_REQ_SCALE;
17523 			/*
17524 			 * Initial send window.  It will be updated with the
17525 			 * next incoming segment to the scaled value.
17526 			 */
17527 			tp->snd_wnd = th->th_win;
17528 			rack_validate_fo_sendwin_up(tp, rack);
17529 			if ((to.to_flags & TOF_TS) &&
17530 			    (tp->t_flags & TF_REQ_TSTMP)) {
17531 				tp->t_flags |= TF_RCVD_TSTMP;
17532 				tp->ts_recent = to.to_tsval;
17533 				tp->ts_recent_age = cts;
17534 			} else
17535 				tp->t_flags &= ~TF_REQ_TSTMP;
17536 			if (to.to_flags & TOF_MSS) {
17537 				tcp_mss(tp, to.to_mss);
17538 			}
17539 			if ((tp->t_flags & TF_SACK_PERMIT) &&
17540 			    (to.to_flags & TOF_SACKPERM) == 0)
17541 				tp->t_flags &= ~TF_SACK_PERMIT;
17542 			if (tp->t_flags & TF_FASTOPEN) {
17543 				if (to.to_flags & TOF_FASTOPEN) {
17544 					uint16_t mss;
17545 
17546 					if (to.to_flags & TOF_MSS)
17547 						mss = to.to_mss;
17548 					else
17549 						if ((inp->inp_vflag & INP_IPV6) != 0)
17550 							mss = TCP6_MSS;
17551 						else
17552 							mss = TCP_MSS;
17553 					tcp_fastopen_update_cache(tp, mss,
17554 					    to.to_tfo_len, to.to_tfo_cookie);
17555 				} else
17556 					tcp_fastopen_disable_path(tp);
17557 			}
17558 		}
17559 		/*
17560 		 * At this point we are at the initial call. Here we decide
17561 		 * if we are doing RACK or not. We do this by seeing if
17562 		 * TF_SACK_PERMIT is set and the sack-not-required is clear.
17563 		 * The code now does do dup-ack counting so if you don't
17564 		 * switch back you won't get rack & TLP, but you will still
17565 		 * get this stack.
17566 		 */
17567 
17568 		if ((rack_sack_not_required == 0) &&
17569 		    ((tp->t_flags & TF_SACK_PERMIT) == 0)) {
17570 			tcp_switch_back_to_default(tp);
17571 			(*tp->t_fb->tfb_tcp_do_segment)(tp, m, th, drop_hdrlen,
17572 			    tlen, iptos);
17573 #ifdef TCP_ACCOUNTING
17574 			sched_unpin();
17575 #endif
17576 			return (1);
17577 		}
17578 		tcp_set_hpts(tp);
17579 		sack_filter_clear(&rack->r_ctl.rack_sf, th->th_ack);
17580 	}
17581 	if (thflags & TH_FIN)
17582 		tcp_log_end_status(tp, TCP_EI_STATUS_CLIENT_FIN);
17583 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
17584 	if ((rack->rc_gp_dyn_mul) &&
17585 	    (rack->use_fixed_rate == 0) &&
17586 	    (rack->rc_always_pace)) {
17587 		/* Check in on probertt */
17588 		rack_check_probe_rtt(rack, cts);
17589 	}
17590 	rack_clear_rate_sample(rack);
17591 	if ((rack->forced_ack) &&
17592 	    ((tcp_get_flags(th) & TH_RST) == 0)) {
17593 		rack_handle_probe_response(rack, tiwin, us_cts);
17594 	}
17595 	/*
17596 	 * This is the one exception case where we set the rack state
17597 	 * always. All other times (timers etc) we must have a rack-state
17598 	 * set (so we assure we have done the checks above for SACK).
17599 	 */
17600 	rack->r_ctl.rc_rcvtime = cts;
17601 	if (rack->r_state != tp->t_state)
17602 		rack_set_state(tp, rack);
17603 	if (SEQ_GT(th->th_ack, tp->snd_una) &&
17604 	    (rsm = tqhash_min(rack->r_ctl.tqh)) != NULL)
17605 		kern_prefetch(rsm, &prev_state);
17606 	prev_state = rack->r_state;
17607 	if ((thflags & TH_RST) &&
17608 	    ((SEQ_GEQ(th->th_seq, tp->last_ack_sent) &&
17609 	      SEQ_LT(th->th_seq, tp->last_ack_sent + tp->rcv_wnd)) ||
17610 	     (tp->rcv_wnd == 0 && tp->last_ack_sent == th->th_seq))) {
17611 		/* The connection will be killed by a reset check the tracepoint */
17612 		tcp_trace_point(rack->rc_tp, TCP_TP_RESET_RCV);
17613 	}
17614 	retval = (*rack->r_substate) (m, th, so,
17615 	    tp, &to, drop_hdrlen,
17616 	    tlen, tiwin, thflags, nxt_pkt, iptos);
17617 	if (retval == 0) {
17618 		/*
17619 		 * If retval is 1 the tcb is unlocked and most likely the tp
17620 		 * is gone.
17621 		 */
17622 		INP_WLOCK_ASSERT(inp);
17623 		if ((rack->rc_gp_dyn_mul) &&
17624 		    (rack->rc_always_pace) &&
17625 		    (rack->use_fixed_rate == 0) &&
17626 		    rack->in_probe_rtt &&
17627 		    (rack->r_ctl.rc_time_probertt_starts == 0)) {
17628 			/*
17629 			 * If we are going for target, lets recheck before
17630 			 * we output.
17631 			 */
17632 			rack_check_probe_rtt(rack, cts);
17633 		}
17634 		if (rack->set_pacing_done_a_iw == 0) {
17635 			/* How much has been acked? */
17636 			if ((tp->snd_una - tp->iss) > (ctf_fixed_maxseg(tp) * 10)) {
17637 				/* We have enough to set in the pacing segment size */
17638 				rack->set_pacing_done_a_iw = 1;
17639 				rack_set_pace_segments(tp, rack, __LINE__, NULL);
17640 			}
17641 		}
17642 		tcp_rack_xmit_timer_commit(rack, tp);
17643 #ifdef TCP_ACCOUNTING
17644 		/*
17645 		 * If we set the ack_val_se to what ack processing we are doing
17646 		 * we also want to track how many cycles we burned. Note
17647 		 * the bits after tcp_output we let be "free". This is because
17648 		 * we are also tracking the tcp_output times as well. Note the
17649 		 * use of 0xf here since we only have 11 counter (0 - 0xa) and
17650 		 * 0xf cannot be returned and is what we initialize it too to
17651 		 * indicate we are not doing the tabulations.
17652 		 */
17653 		if (ack_val_set != 0xf) {
17654 			uint64_t crtsc;
17655 
17656 			crtsc = get_cyclecount();
17657 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17658 				tp->tcp_proc_time[ack_val_set] += (crtsc - ts_val);
17659 			}
17660 		}
17661 #endif
17662 		if ((nxt_pkt == 0) && (no_output == 0)) {
17663 			if ((rack->r_wanted_output != 0) ||
17664 			    (tp->t_flags & TF_ACKNOW) ||
17665 			    (rack->r_fast_output != 0)) {
17666 
17667 do_output_now:
17668 				if (tcp_output(tp) < 0) {
17669 #ifdef TCP_ACCOUNTING
17670 					sched_unpin();
17671 #endif
17672 					return (1);
17673 				}
17674 				did_out = 1;
17675 			}
17676 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
17677 			rack_free_trim(rack);
17678 		} else if ((nxt_pkt == 0) && (tp->t_flags & TF_ACKNOW)) {
17679 			goto do_output_now;
17680 		} else if ((no_output == 1) &&
17681 			   (nxt_pkt == 0)  &&
17682 			   (tcp_in_hpts(rack->rc_tp) == 0)) {
17683 			/*
17684 			 * We are not in hpts and we had a pacing timer up. Use
17685 			 * the remaining time (slot_remaining) to restart the timer.
17686 			 */
17687 			KASSERT ((slot_remaining != 0), ("slot remaining is zero for rack:%p tp:%p", rack, tp));
17688 			rack_start_hpts_timer(rack, tp, cts, slot_remaining, 0, 0);
17689 			rack_free_trim(rack);
17690 		}
17691 		/* Clear the flag, it may have been cleared by output but we may not have  */
17692 		if ((nxt_pkt == 0) && (tp->t_flags2 & TF2_HPTS_CALLS))
17693 			tp->t_flags2 &= ~TF2_HPTS_CALLS;
17694 		/*
17695 		 * The draft (v3) calls for us to use SEQ_GEQ, but that
17696 		 * causes issues when we are just going app limited. Lets
17697 		 * instead use SEQ_GT <or> where its equal but more data
17698 		 * is outstanding.
17699 		 *
17700 		 * Also make sure we are on the last ack of a series. We
17701 		 * have to have all the ack's processed in queue to know
17702 		 * if there is something left outstanding.
17703 		 */
17704 		if (SEQ_GEQ(tp->snd_una, rack->r_ctl.roundends) &&
17705 		    (rack->rc_new_rnd_needed == 0) &&
17706 		    (nxt_pkt == 0)) {
17707 			/*
17708 			 * We have crossed into a new round with
17709 			 * the new snd_unae.
17710 			 */
17711 			rack_new_round_setup(tp, rack, tp->snd_una);
17712 		}
17713 		if ((nxt_pkt == 0) &&
17714 		    ((rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) == 0) &&
17715 		    (SEQ_GT(tp->snd_max, tp->snd_una) ||
17716 		     (tp->t_flags & TF_DELACK) ||
17717 		     ((V_tcp_always_keepalive || rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
17718 		      (tp->t_state <= TCPS_CLOSING)))) {
17719 			/* We could not send (probably in the hpts but stopped the timer earlier)? */
17720 			if ((tp->snd_max == tp->snd_una) &&
17721 			    ((tp->t_flags & TF_DELACK) == 0) &&
17722 			    (tcp_in_hpts(rack->rc_tp)) &&
17723 			    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
17724 				/* keep alive not needed if we are hptsi output yet */
17725 				;
17726 			} else {
17727 				int late = 0;
17728 				if (tcp_in_hpts(tp)) {
17729 					if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
17730 						us_cts = tcp_get_usecs(NULL);
17731 						if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
17732 							rack->r_early = 1;
17733 							rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
17734 						} else
17735 							late = 1;
17736 						rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
17737 					}
17738 					tcp_hpts_remove(tp);
17739 				}
17740 				if (late && (did_out == 0)) {
17741 					/*
17742 					 * We are late in the sending
17743 					 * and we did not call the output
17744 					 * (this probably should not happen).
17745 					 */
17746 					goto do_output_now;
17747 				}
17748 				rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
17749 			}
17750 			way_out = 1;
17751 		} else if (nxt_pkt == 0) {
17752 			/* Do we have the correct timer running? */
17753 			rack_timer_audit(tp, rack, &so->so_snd);
17754 			way_out = 2;
17755 		}
17756 	done_with_input:
17757 		rack_log_doseg_done(rack, cts, nxt_pkt, did_out, way_out, max(1, nsegs));
17758 		if (did_out)
17759 			rack->r_wanted_output = 0;
17760 	}
17761 
17762 #ifdef TCP_ACCOUNTING
17763 	sched_unpin();
17764 #endif
17765 	return (retval);
17766 }
17767 
17768 static void
rack_do_segment(struct tcpcb * tp,struct mbuf * m,struct tcphdr * th,int32_t drop_hdrlen,int32_t tlen,uint8_t iptos)17769 rack_do_segment(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
17770     int32_t drop_hdrlen, int32_t tlen, uint8_t iptos)
17771 {
17772 	struct timeval tv;
17773 
17774 	/* First lets see if we have old packets */
17775 	if (!STAILQ_EMPTY(&tp->t_inqueue)) {
17776 		if (ctf_do_queued_segments(tp, 1)) {
17777 			m_freem(m);
17778 			return;
17779 		}
17780 	}
17781 	if (m->m_flags & M_TSTMP_LRO) {
17782 		mbuf_tstmp2timeval(m, &tv);
17783 	} else {
17784 		/* Should not be should we kassert instead? */
17785 		tcp_get_usecs(&tv);
17786 	}
17787 	if (rack_do_segment_nounlock(tp, m, th, drop_hdrlen, tlen, iptos, 0,
17788 	    &tv) == 0) {
17789 		INP_WUNLOCK(tptoinpcb(tp));
17790 	}
17791 }
17792 
17793 struct rack_sendmap *
tcp_rack_output(struct tcpcb * tp,struct tcp_rack * rack,uint32_t tsused)17794 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack, uint32_t tsused)
17795 {
17796 	struct rack_sendmap *rsm = NULL;
17797 	int32_t idx;
17798 	uint32_t srtt = 0, thresh = 0, ts_low = 0;
17799 
17800 	/* Return the next guy to be re-transmitted */
17801 	if (tqhash_empty(rack->r_ctl.tqh)) {
17802 		return (NULL);
17803 	}
17804 	if (tp->t_flags & TF_SENTFIN) {
17805 		/* retran the end FIN? */
17806 		return (NULL);
17807 	}
17808 	/* ok lets look at this one */
17809 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
17810 	if (rack->r_must_retran && rsm && (rsm->r_flags & RACK_MUST_RXT)) {
17811 		return (rsm);
17812 	}
17813 	if (rsm && ((rsm->r_flags & RACK_ACKED) == 0)) {
17814 		goto check_it;
17815 	}
17816 	rsm = rack_find_lowest_rsm(rack);
17817 	if (rsm == NULL) {
17818 		return (NULL);
17819 	}
17820 check_it:
17821 	if (((rack->rc_tp->t_flags & TF_SACK_PERMIT) == 0) &&
17822 	    (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
17823 		/*
17824 		 * No sack so we automatically do the 3 strikes and
17825 		 * retransmit (no rack timer would be started).
17826 		 */
17827 		return (rsm);
17828 	}
17829 	if (rsm->r_flags & RACK_ACKED) {
17830 		return (NULL);
17831 	}
17832 	if (((rsm->r_flags & RACK_SACK_PASSED) == 0) &&
17833 	    (rsm->r_dupack < DUP_ACK_THRESHOLD)) {
17834 		/* Its not yet ready */
17835 		return (NULL);
17836 	}
17837 	srtt = rack_grab_rtt(tp, rack);
17838 	idx = rsm->r_rtr_cnt - 1;
17839 	ts_low = (uint32_t)rsm->r_tim_lastsent[idx];
17840 	thresh = rack_calc_thresh_rack(rack, srtt, tsused, __LINE__, 1);
17841 	if ((tsused == ts_low) ||
17842 	    (TSTMP_LT(tsused, ts_low))) {
17843 		/* No time since sending */
17844 		return (NULL);
17845 	}
17846 	if ((tsused - ts_low) < thresh) {
17847 		/* It has not been long enough yet */
17848 		return (NULL);
17849 	}
17850 	if ((rsm->r_dupack >= DUP_ACK_THRESHOLD) ||
17851 	    ((rsm->r_flags & RACK_SACK_PASSED))) {
17852 		/*
17853 		 * We have passed the dup-ack threshold <or>
17854 		 * a SACK has indicated this is missing.
17855 		 * Note that if you are a declared attacker
17856 		 * it is only the dup-ack threshold that
17857 		 * will cause retransmits.
17858 		 */
17859 		/* log retransmit reason */
17860 		rack_log_retran_reason(rack, rsm, (tsused - ts_low), thresh, 1);
17861 		rack->r_fast_output = 0;
17862 		return (rsm);
17863 	}
17864 	return (NULL);
17865 }
17866 
17867 static void
rack_log_pacing_delay_calc(struct tcp_rack * rack,uint32_t len,uint32_t slot,uint64_t bw_est,uint64_t bw,uint64_t len_time,int method,int line,struct rack_sendmap * rsm,uint8_t quality)17868 rack_log_pacing_delay_calc (struct tcp_rack *rack, uint32_t len, uint32_t slot,
17869 			   uint64_t bw_est, uint64_t bw, uint64_t len_time, int method,
17870 			   int line, struct rack_sendmap *rsm, uint8_t quality)
17871 {
17872 	if (tcp_bblogging_on(rack->rc_tp)) {
17873 		union tcp_log_stackspecific log;
17874 		struct timeval tv;
17875 
17876 		if (rack_verbose_logging == 0) {
17877 			/*
17878 			 * We are not verbose screen out all but
17879 			 * ones we always want.
17880 			 */
17881 			if ((method != 2) &&
17882 			    (method != 3) &&
17883 			    (method != 7) &&
17884 			    (method != 89) &&
17885 			    (method != 14) &&
17886 			    (method != 20)) {
17887 				return;
17888 			}
17889 		}
17890 		memset(&log, 0, sizeof(log));
17891 		log.u_bbr.flex1 = slot;
17892 		log.u_bbr.flex2 = len;
17893 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_min_segs;
17894 		log.u_bbr.flex4 = rack->r_ctl.rc_pace_max_segs;
17895 		log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ss;
17896 		log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_ca;
17897 		log.u_bbr.use_lt_bw = rack->rc_ack_can_sendout_data;
17898 		log.u_bbr.use_lt_bw <<= 1;
17899 		log.u_bbr.use_lt_bw |= rack->r_late;
17900 		log.u_bbr.use_lt_bw <<= 1;
17901 		log.u_bbr.use_lt_bw |= rack->r_early;
17902 		log.u_bbr.use_lt_bw <<= 1;
17903 		log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
17904 		log.u_bbr.use_lt_bw <<= 1;
17905 		log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
17906 		log.u_bbr.use_lt_bw <<= 1;
17907 		log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
17908 		log.u_bbr.use_lt_bw <<= 1;
17909 		log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
17910 		log.u_bbr.use_lt_bw <<= 1;
17911 		log.u_bbr.use_lt_bw |= rack->gp_ready;
17912 		log.u_bbr.pkt_epoch = line;
17913 		log.u_bbr.epoch = rack->r_ctl.rc_agg_delayed;
17914 		log.u_bbr.lt_epoch = rack->r_ctl.rc_agg_early;
17915 		log.u_bbr.applimited = rack->r_ctl.rack_per_of_gp_rec;
17916 		log.u_bbr.bw_inuse = bw_est;
17917 		log.u_bbr.delRate = bw;
17918 		if (rack->r_ctl.gp_bw == 0)
17919 			log.u_bbr.cur_del_rate = 0;
17920 		else
17921 			log.u_bbr.cur_del_rate = rack_get_bw(rack);
17922 		log.u_bbr.rttProp = len_time;
17923 		log.u_bbr.pkts_out = rack->r_ctl.rc_rack_min_rtt;
17924 		log.u_bbr.lost = rack->r_ctl.rc_probertt_sndmax_atexit;
17925 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
17926 		if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh) {
17927 			/* We are in slow start */
17928 			log.u_bbr.flex7 = 1;
17929 		} else {
17930 			/* we are on congestion avoidance */
17931 			log.u_bbr.flex7 = 0;
17932 		}
17933 		log.u_bbr.flex8 = method;
17934 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
17935 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
17936 		log.u_bbr.cwnd_gain = rack->rc_gp_saw_rec;
17937 		log.u_bbr.cwnd_gain <<= 1;
17938 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
17939 		log.u_bbr.cwnd_gain <<= 1;
17940 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
17941 		log.u_bbr.bbr_substate = quality;
17942 		log.u_bbr.bbr_state = rack->dgp_on;
17943 		log.u_bbr.bbr_state <<= 1;
17944 		log.u_bbr.bbr_state |= rack->rc_pace_to_cwnd;
17945 		log.u_bbr.bbr_state <<= 2;
17946 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
17947 		    &rack->rc_inp->inp_socket->so_rcv,
17948 		    &rack->rc_inp->inp_socket->so_snd,
17949 		    BBR_LOG_HPTSI_CALC, 0,
17950 		    0, &log, false, &tv);
17951 	}
17952 }
17953 
17954 static uint32_t
rack_get_pacing_len(struct tcp_rack * rack,uint64_t bw,uint32_t mss)17955 rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss)
17956 {
17957 	uint32_t new_tso, user_max, pace_one;
17958 
17959 	user_max = rack->rc_user_set_max_segs * mss;
17960 	if (rack->rc_force_max_seg) {
17961 		return (user_max);
17962 	}
17963 	if (rack->use_fixed_rate &&
17964 	    ((rack->r_ctl.crte == NULL) ||
17965 	     (bw != rack->r_ctl.crte->rate))) {
17966 		/* Use the user mss since we are not exactly matched */
17967 		return (user_max);
17968 	}
17969 	if (rack_pace_one_seg ||
17970 	    (rack->r_ctl.rc_user_set_min_segs == 1))
17971 		pace_one = 1;
17972 	else
17973 		pace_one = 0;
17974 
17975 	new_tso = tcp_get_pacing_burst_size_w_divisor(rack->rc_tp, bw, mss,
17976 		     pace_one, rack->r_ctl.crte, NULL, rack->r_ctl.pace_len_divisor);
17977 	if (new_tso > user_max)
17978 		new_tso = user_max;
17979 	if (rack->rc_hybrid_mode && rack->r_ctl.client_suggested_maxseg) {
17980 		if (((uint32_t)rack->r_ctl.client_suggested_maxseg * mss) > new_tso)
17981 			new_tso = (uint32_t)rack->r_ctl.client_suggested_maxseg * mss;
17982 	}
17983 	if (rack->r_ctl.rc_user_set_min_segs &&
17984 	    ((rack->r_ctl.rc_user_set_min_segs * mss) > new_tso))
17985 	    new_tso = rack->r_ctl.rc_user_set_min_segs * mss;
17986 	return (new_tso);
17987 }
17988 
17989 static uint64_t
rack_arrive_at_discounted_rate(struct tcp_rack * rack,uint64_t window_input,uint32_t * rate_set,uint32_t * gain_b)17990 rack_arrive_at_discounted_rate(struct tcp_rack *rack, uint64_t window_input, uint32_t *rate_set, uint32_t *gain_b)
17991 {
17992 	uint64_t reduced_win;
17993 	uint32_t gain;
17994 
17995 	if (window_input < rc_init_window(rack)) {
17996 		/*
17997 		 * The cwnd is collapsed to
17998 		 * nearly zero, maybe because of a time-out?
17999 		 * Lets drop back to the lt-bw.
18000 		 */
18001 		reduced_win = rack_get_lt_bw(rack);
18002 		/* Set the flag so the caller knows its a rate and not a reduced window */
18003 		*rate_set = 1;
18004 		gain = 100;
18005 	} else if  (IN_RECOVERY(rack->rc_tp->t_flags)) {
18006 		/*
18007 		 * If we are in recover our cwnd needs to be less for
18008 		 * our pacing consideration.
18009 		 */
18010 		if (rack->rack_hibeta == 0) {
18011 			reduced_win = window_input / 2;
18012 			gain = 50;
18013 		} else {
18014 			reduced_win = window_input * rack->r_ctl.saved_hibeta;
18015 			reduced_win /= 100;
18016 			gain = rack->r_ctl.saved_hibeta;
18017 		}
18018 	} else {
18019 		/*
18020 		 * Apply Timely factor to increase/decrease the
18021 		 * amount we are pacing at.
18022 		 */
18023 		gain = rack_get_output_gain(rack, NULL);
18024 		if (gain > rack_gain_p5_ub) {
18025 			gain = rack_gain_p5_ub;
18026 		}
18027 		reduced_win = window_input * gain;
18028 		reduced_win /= 100;
18029 	}
18030 	if (gain_b != NULL)
18031 		*gain_b = gain;
18032 	/*
18033 	 * What is being returned here is a trimmed down
18034 	 * window values in all cases where rate_set is left
18035 	 * at 0. In one case we actually return the rate (lt_bw).
18036 	 * the "reduced_win" is returned as a slimmed down cwnd that
18037 	 * is then calculated by the caller into a rate when rate_set
18038 	 * is 0.
18039 	 */
18040 	return (reduced_win);
18041 }
18042 
18043 static int32_t
pace_to_fill_cwnd(struct tcp_rack * rack,int32_t slot,uint32_t len,uint32_t segsiz,int * capped,uint64_t * rate_wanted,uint8_t non_paced)18044 pace_to_fill_cwnd(struct tcp_rack *rack, int32_t slot, uint32_t len, uint32_t segsiz, int *capped, uint64_t *rate_wanted, uint8_t non_paced)
18045 {
18046 	uint64_t lentim, fill_bw;
18047 
18048 	rack->r_via_fill_cw = 0;
18049 	if (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.cwnd_to_use)
18050 		return (slot);
18051 	if ((ctf_outstanding(rack->rc_tp) + (segsiz-1)) > rack->rc_tp->snd_wnd)
18052 		return (slot);
18053 	if (rack->r_ctl.rc_last_us_rtt == 0)
18054 		return (slot);
18055 	if (rack->rc_pace_fill_if_rttin_range &&
18056 	    (rack->r_ctl.rc_last_us_rtt >=
18057 	     (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack->rtt_limit_mul))) {
18058 		/* The rtt is huge, N * smallest, lets not fill */
18059 		return (slot);
18060 	}
18061 	if (rack->r_ctl.fillcw_cap && *rate_wanted >= rack->r_ctl.fillcw_cap)
18062 		return (slot);
18063 	/*
18064 	 * first lets calculate the b/w based on the last us-rtt
18065 	 * and the the smallest send window.
18066 	 */
18067 	fill_bw = min(rack->rc_tp->snd_cwnd, rack->r_ctl.cwnd_to_use);
18068 	if (rack->rc_fillcw_apply_discount) {
18069 		uint32_t rate_set = 0;
18070 
18071 		fill_bw = rack_arrive_at_discounted_rate(rack, fill_bw, &rate_set, NULL);
18072 		if (rate_set) {
18073 			goto at_lt_bw;
18074 		}
18075 	}
18076 	/* Take the rwnd if its smaller */
18077 	if (fill_bw > rack->rc_tp->snd_wnd)
18078 		fill_bw = rack->rc_tp->snd_wnd;
18079 	/* Now lets make it into a b/w */
18080 	fill_bw *= (uint64_t)HPTS_USEC_IN_SEC;
18081 	fill_bw /= (uint64_t)rack->r_ctl.rc_last_us_rtt;
18082 	/* Adjust to any cap */
18083 	if (rack->r_ctl.fillcw_cap && fill_bw >= rack->r_ctl.fillcw_cap)
18084 		fill_bw = rack->r_ctl.fillcw_cap;
18085 
18086 at_lt_bw:
18087 	if (rack_bw_multipler > 0) {
18088 		/*
18089 		 * We want to limit fill-cw to the some multiplier
18090 		 * of the max(lt_bw, gp_est). The normal default
18091 		 * is 0 for off, so a sysctl has enabled it.
18092 		 */
18093 		uint64_t lt_bw, gp, rate;
18094 
18095 		gp = rack_get_gp_est(rack);
18096 		lt_bw = rack_get_lt_bw(rack);
18097 		if (lt_bw > gp)
18098 			rate = lt_bw;
18099 		else
18100 			rate = gp;
18101 		rate *= rack_bw_multipler;
18102 		rate /= 100;
18103 		if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
18104 			union tcp_log_stackspecific log;
18105 			struct timeval tv;
18106 
18107 			memset(&log.u_bbr, 0, sizeof(log.u_bbr));
18108 			log.u_bbr.timeStamp = tcp_get_usecs(&tv);
18109 			log.u_bbr.flex1 = rack_bw_multipler;
18110 			log.u_bbr.flex2 = len;
18111 			log.u_bbr.cur_del_rate = gp;
18112 			log.u_bbr.delRate = lt_bw;
18113 			log.u_bbr.bw_inuse = rate;
18114 			log.u_bbr.rttProp = fill_bw;
18115 			log.u_bbr.flex8 = 44;
18116 			tcp_log_event(rack->rc_tp, NULL, NULL, NULL,
18117 				      BBR_LOG_CWND, 0,
18118 				      0, &log, false, NULL,
18119 				      __func__, __LINE__, &tv);
18120 		}
18121 		if (fill_bw > rate)
18122 			fill_bw = rate;
18123 	}
18124 	/* We are below the min b/w */
18125 	if (non_paced)
18126 		*rate_wanted = fill_bw;
18127 	if ((fill_bw < RACK_MIN_BW) || (fill_bw < *rate_wanted))
18128 		return (slot);
18129 	rack->r_via_fill_cw = 1;
18130 	if (rack->r_rack_hw_rate_caps &&
18131 	    (rack->r_ctl.crte != NULL)) {
18132 		uint64_t high_rate;
18133 
18134 		high_rate = tcp_hw_highest_rate(rack->r_ctl.crte);
18135 		if (fill_bw > high_rate) {
18136 			/* We are capping bw at the highest rate table entry */
18137 			if (*rate_wanted > high_rate) {
18138 				/* The original rate was also capped */
18139 				rack->r_via_fill_cw = 0;
18140 			}
18141 			rack_log_hdwr_pacing(rack,
18142 					     fill_bw, high_rate, __LINE__,
18143 					     0, 3);
18144 			fill_bw = high_rate;
18145 			if (capped)
18146 				*capped = 1;
18147 		}
18148 	} else if ((rack->r_ctl.crte == NULL) &&
18149 		   (rack->rack_hdrw_pacing == 0) &&
18150 		   (rack->rack_hdw_pace_ena) &&
18151 		   rack->r_rack_hw_rate_caps &&
18152 		   (rack->rack_attempt_hdwr_pace == 0) &&
18153 		   (rack->rc_inp->inp_route.ro_nh != NULL) &&
18154 		   (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
18155 		/*
18156 		 * Ok we may have a first attempt that is greater than our top rate
18157 		 * lets check.
18158 		 */
18159 		uint64_t high_rate;
18160 
18161 		high_rate = tcp_hw_highest_rate_ifp(rack->rc_inp->inp_route.ro_nh->nh_ifp, rack->rc_inp);
18162 		if (high_rate) {
18163 			if (fill_bw > high_rate) {
18164 				fill_bw = high_rate;
18165 				if (capped)
18166 					*capped = 1;
18167 			}
18168 		}
18169 	}
18170 	if (rack->r_ctl.bw_rate_cap && (fill_bw > rack->r_ctl.bw_rate_cap)) {
18171 		rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
18172 				   fill_bw, 0, 0, HYBRID_LOG_RATE_CAP, 2, NULL, __LINE__);
18173 		fill_bw = rack->r_ctl.bw_rate_cap;
18174 	}
18175 	/*
18176 	 * Ok fill_bw holds our mythical b/w to fill the cwnd
18177 	 * in an rtt (unless it was capped), what does that
18178 	 * time wise equate too?
18179 	 */
18180 	lentim = (uint64_t)(len) * (uint64_t)HPTS_USEC_IN_SEC;
18181 	lentim /= fill_bw;
18182 	*rate_wanted = fill_bw;
18183 	if (non_paced || (lentim < slot)) {
18184 		rack_log_pacing_delay_calc(rack, len, slot, fill_bw,
18185 					   0, lentim, 12, __LINE__, NULL, 0);
18186 		return ((int32_t)lentim);
18187 	} else
18188 		return (slot);
18189 }
18190 
18191 static uint32_t
rack_policer_check_send(struct tcp_rack * rack,uint32_t len,uint32_t segsiz,uint32_t * needs)18192 rack_policer_check_send(struct tcp_rack *rack, uint32_t len, uint32_t segsiz, uint32_t *needs)
18193 {
18194 	uint64_t calc;
18195 
18196 	rack->rc_policer_should_pace = 0;
18197 	calc = rack_policer_bucket_reserve * rack->r_ctl.policer_bucket_size;
18198 	calc /= 100;
18199 	/*
18200 	 * Now lets look at if we want more than is in the bucket <or>
18201 	 * we want more than is reserved in the bucket.
18202 	 */
18203 	if (rack_verbose_logging > 0)
18204 		policer_detection_log(rack, len, segsiz, calc, rack->r_ctl.current_policer_bucket, 8);
18205 	if ((calc > rack->r_ctl.current_policer_bucket) ||
18206 	    (len >= (rack->r_ctl.current_policer_bucket - calc))) {
18207 		/*
18208 		 * We may want to pace depending on if we are going
18209 		 * into the reserve or not.
18210 		 */
18211 		uint32_t newlen;
18212 
18213 		if (calc > rack->r_ctl.current_policer_bucket) {
18214 			/*
18215 			 * This will eat into the reserve if we
18216 			 * don't have room at all some lines
18217 			 * below will catch it.
18218 			 */
18219 			newlen = rack->r_ctl.policer_max_seg;
18220 			rack->rc_policer_should_pace = 1;
18221 		} else {
18222 			/*
18223 			 * We have all of the reserve plus something in the bucket
18224 			 * that we can give out.
18225 			 */
18226 			newlen = rack->r_ctl.current_policer_bucket - calc;
18227 			if (newlen < rack->r_ctl.policer_max_seg) {
18228 				/*
18229 				 * Into the reserve to get a full policer_max_seg
18230 				 * so we set the len to that and eat into
18231 				 * the reserve. If we go over the code
18232 				 * below will make us wait.
18233 				 */
18234 				newlen = rack->r_ctl.policer_max_seg;
18235 				rack->rc_policer_should_pace = 1;
18236 			}
18237 		}
18238 		if (newlen > rack->r_ctl.current_policer_bucket) {
18239 			/* We have to wait some */
18240 			*needs = newlen - rack->r_ctl.current_policer_bucket;
18241 			return (0);
18242 		}
18243 		if (rack_verbose_logging > 0)
18244 			policer_detection_log(rack, len, segsiz, newlen, 0, 9);
18245 		len = newlen;
18246 	} /* else we have all len available above the reserve */
18247 	if (rack_verbose_logging > 0)
18248 		policer_detection_log(rack, len, segsiz, calc, 0, 10);
18249 	return (len);
18250 }
18251 
18252 static uint32_t
rack_policed_sending(struct tcp_rack * rack,struct tcpcb * tp,uint32_t len,uint32_t segsiz,int call_line)18253 rack_policed_sending(struct tcp_rack *rack, struct tcpcb *tp, uint32_t len, uint32_t segsiz, int call_line)
18254 {
18255 	/*
18256 	 * Given a send of len, and a token bucket set at current_policer_bucket_size
18257 	 * are we close enough to the end of the bucket that we need to pace? If so
18258 	 * calculate out a time and return it. Otherwise subtract the tokens from
18259 	 * the bucket.
18260 	 */
18261 	uint64_t calc;
18262 
18263 	if ((rack->r_ctl.policer_bw == 0) ||
18264 	    (rack->r_ctl.policer_bucket_size < segsiz)) {
18265 		/*
18266 		 * We should have an estimate here...
18267 		 */
18268 		return (0);
18269 	}
18270 	calc = (uint64_t)rack_policer_bucket_reserve * (uint64_t)rack->r_ctl.policer_bucket_size;
18271 	calc /= 100;
18272 	if ((rack->r_ctl.current_policer_bucket < len) ||
18273 	    (rack->rc_policer_should_pace == 1) ||
18274 	    ((rack->r_ctl.current_policer_bucket - len) <= (uint32_t)calc)) {
18275 		/* we need to pace */
18276 		uint64_t lentim, res;
18277 		uint32_t slot;
18278 
18279 		lentim = (uint64_t)len * (uint64_t)HPTS_USEC_IN_SEC;
18280 		res = lentim / rack->r_ctl.policer_bw;
18281 		slot = (uint32_t)res;
18282 		if (rack->r_ctl.current_policer_bucket > len)
18283 			rack->r_ctl.current_policer_bucket -= len;
18284 		else
18285 			rack->r_ctl.current_policer_bucket = 0;
18286 		policer_detection_log(rack, len, slot, (uint32_t)rack_policer_bucket_reserve, call_line, 5);
18287 		rack->rc_policer_should_pace = 0;
18288 		return(slot);
18289 	}
18290 	/* Just take tokens out of the bucket and let rack do whatever it would have */
18291 	policer_detection_log(rack, len, 0, (uint32_t)rack_policer_bucket_reserve, call_line, 6);
18292 	if (len < rack->r_ctl.current_policer_bucket) {
18293 		rack->r_ctl.current_policer_bucket -= len;
18294 	} else {
18295 		rack->r_ctl.current_policer_bucket = 0;
18296 	}
18297 	return (0);
18298 }
18299 
18300 
18301 static int32_t
rack_get_pacing_delay(struct tcp_rack * rack,struct tcpcb * tp,uint32_t len,struct rack_sendmap * rsm,uint32_t segsiz,int line)18302 rack_get_pacing_delay(struct tcp_rack *rack, struct tcpcb *tp, uint32_t len, struct rack_sendmap *rsm, uint32_t segsiz, int line)
18303 {
18304 	uint64_t srtt;
18305 	int32_t slot = 0;
18306 	int32_t minslot = 0;
18307 	int can_start_hw_pacing = 1;
18308 	int err;
18309 	int pace_one;
18310 
18311 	if (rack_pace_one_seg ||
18312 	    (rack->r_ctl.rc_user_set_min_segs == 1))
18313 		pace_one = 1;
18314 	else
18315 		pace_one = 0;
18316 	if (rack->rc_policer_detected == 1) {
18317 		/*
18318 		 * A policer has been detected and we
18319 		 * have all of our data (policer-bw and
18320 		 * policer bucket size) calculated. Call
18321 		 * into the function to find out if we are
18322 		 * overriding the time.
18323 		 */
18324 		slot = rack_policed_sending(rack, tp, len, segsiz, line);
18325 		if (slot) {
18326 			uint64_t logbw;
18327 
18328 			logbw = rack->r_ctl.current_policer_bucket;
18329 			logbw <<= 32;
18330 			logbw |= rack->r_ctl.policer_bucket_size;
18331 			rack_log_pacing_delay_calc(rack, len, slot, rack->r_ctl.policer_bw, logbw, 0, 89, __LINE__, NULL, 0);
18332 			return(slot);
18333 		}
18334 	}
18335 	if (rack->rc_always_pace == 0) {
18336 		/*
18337 		 * We use the most optimistic possible cwnd/srtt for
18338 		 * sending calculations. This will make our
18339 		 * calculation anticipate getting more through
18340 		 * quicker then possible. But thats ok we don't want
18341 		 * the peer to have a gap in data sending.
18342 		 */
18343 		uint64_t cwnd, tr_perms = 0;
18344 		int32_t reduce = 0;
18345 
18346 	old_method:
18347 		/*
18348 		 * We keep no precise pacing with the old method
18349 		 * instead we use the pacer to mitigate bursts.
18350 		 */
18351 		if (rack->r_ctl.rc_rack_min_rtt)
18352 			srtt = rack->r_ctl.rc_rack_min_rtt;
18353 		else
18354 			srtt = max(tp->t_srtt, 1);
18355 		if (rack->r_ctl.rc_rack_largest_cwnd)
18356 			cwnd = rack->r_ctl.rc_rack_largest_cwnd;
18357 		else
18358 			cwnd = rack->r_ctl.cwnd_to_use;
18359 		/* Inflate cwnd by 1000 so srtt of usecs is in ms */
18360 		tr_perms = (cwnd * 1000) / srtt;
18361 		if (tr_perms == 0) {
18362 			tr_perms = ctf_fixed_maxseg(tp);
18363 		}
18364 		/*
18365 		 * Calculate how long this will take to drain, if
18366 		 * the calculation comes out to zero, thats ok we
18367 		 * will use send_a_lot to possibly spin around for
18368 		 * more increasing tot_len_this_send to the point
18369 		 * that its going to require a pace, or we hit the
18370 		 * cwnd. Which in that case we are just waiting for
18371 		 * a ACK.
18372 		 */
18373 		slot = len / tr_perms;
18374 		/* Now do we reduce the time so we don't run dry? */
18375 		if (slot && rack_slot_reduction) {
18376 			reduce = (slot / rack_slot_reduction);
18377 			if (reduce < slot) {
18378 				slot -= reduce;
18379 			} else
18380 				slot = 0;
18381 		}
18382 		slot *= HPTS_USEC_IN_MSEC;
18383 		if (rack->rc_pace_to_cwnd) {
18384 			uint64_t rate_wanted = 0;
18385 
18386 			slot = pace_to_fill_cwnd(rack, slot, len, segsiz, NULL, &rate_wanted, 1);
18387 			rack->rc_ack_can_sendout_data = 1;
18388 			rack_log_pacing_delay_calc(rack, len, slot, rate_wanted, 0, 0, 14, __LINE__, NULL, 0);
18389 		} else
18390 			rack_log_pacing_delay_calc(rack, len, slot, tr_perms, reduce, 0, 7, __LINE__, NULL, 0);
18391 		/*******************************************************/
18392 		/* RRS: We insert non-paced call to stats here for len */
18393 		/*******************************************************/
18394 	} else {
18395 		uint64_t bw_est, res, lentim, rate_wanted;
18396 		uint32_t segs, oh;
18397 		int capped = 0;
18398 		int prev_fill;
18399 
18400 		if ((rack->r_rr_config == 1) && rsm) {
18401 			return (rack->r_ctl.rc_min_to);
18402 		}
18403 		if (rack->use_fixed_rate) {
18404 			rate_wanted = bw_est = rack_get_fixed_pacing_bw(rack);
18405 		} else if ((rack->r_ctl.init_rate == 0) &&
18406 			   (rack->r_ctl.gp_bw == 0)) {
18407 			/* no way to yet do an estimate */
18408 			bw_est = rate_wanted = 0;
18409 		} else if (rack->dgp_on) {
18410 			bw_est = rack_get_bw(rack);
18411 			rate_wanted = rack_get_output_bw(rack, bw_est, rsm, &capped);
18412 		} else {
18413 			uint32_t gain, rate_set = 0;
18414 
18415 			rate_wanted = min(rack->rc_tp->snd_cwnd, rack->r_ctl.cwnd_to_use);
18416 			rate_wanted = rack_arrive_at_discounted_rate(rack, rate_wanted, &rate_set, &gain);
18417 			if (rate_set == 0) {
18418 				if (rate_wanted > rack->rc_tp->snd_wnd)
18419 					rate_wanted = rack->rc_tp->snd_wnd;
18420 				/* Now lets make it into a b/w */
18421 				rate_wanted *= (uint64_t)HPTS_USEC_IN_SEC;
18422 				rate_wanted /= (uint64_t)rack->r_ctl.rc_last_us_rtt;
18423 			}
18424 			bw_est = rate_wanted;
18425 			rack_log_pacing_delay_calc(rack, rack->rc_tp->snd_cwnd,
18426 						   rack->r_ctl.cwnd_to_use,
18427 						   rate_wanted, bw_est,
18428 						   rack->r_ctl.rc_last_us_rtt,
18429 						   88, __LINE__, NULL, gain);
18430 		}
18431 		if ((bw_est == 0) || (rate_wanted == 0) ||
18432 		    ((rack->gp_ready == 0) && (rack->use_fixed_rate == 0))) {
18433 			/*
18434 			 * No way yet to make a b/w estimate or
18435 			 * our raise is set incorrectly.
18436 			 */
18437 			goto old_method;
18438 		}
18439 		rack_rate_cap_bw(rack, &rate_wanted, &capped);
18440 		/* We need to account for all the overheads */
18441 		segs = (len + segsiz - 1) / segsiz;
18442 		/*
18443 		 * We need the diff between 1514 bytes (e-mtu with e-hdr)
18444 		 * and how much data we put in each packet. Yes this
18445 		 * means we may be off if we are larger than 1500 bytes
18446 		 * or smaller. But this just makes us more conservative.
18447 		 */
18448 
18449 		oh =  (tp->t_maxseg - segsiz) + sizeof(struct tcphdr);
18450 		if (rack->r_is_v6) {
18451 #ifdef INET6
18452 			oh += sizeof(struct ip6_hdr);
18453 #endif
18454 		} else {
18455 #ifdef INET
18456 			oh += sizeof(struct ip);
18457 #endif
18458 		}
18459 		/* We add a fixed 14 for the ethernet header */
18460 		oh += 14;
18461 		segs *= oh;
18462 		lentim = (uint64_t)(len + segs) * (uint64_t)HPTS_USEC_IN_SEC;
18463 		res = lentim / rate_wanted;
18464 		slot = (uint32_t)res;
18465 		if (rack_hw_rate_min &&
18466 		    (rate_wanted < rack_hw_rate_min)) {
18467 			can_start_hw_pacing = 0;
18468 			if (rack->r_ctl.crte) {
18469 				/*
18470 				 * Ok we need to release it, we
18471 				 * have fallen too low.
18472 				 */
18473 				tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
18474 				rack->r_ctl.crte = NULL;
18475 				rack->rack_attempt_hdwr_pace = 0;
18476 				rack->rack_hdrw_pacing = 0;
18477 			}
18478 		}
18479 		if (rack->r_ctl.crte &&
18480 		    (tcp_hw_highest_rate(rack->r_ctl.crte) < rate_wanted)) {
18481 			/*
18482 			 * We want more than the hardware can give us,
18483 			 * don't start any hw pacing.
18484 			 */
18485 			can_start_hw_pacing = 0;
18486 			if (rack->r_rack_hw_rate_caps == 0) {
18487 				/*
18488 				 * Ok we need to release it, we
18489 				 * want more than the card can give us and
18490 				 * no rate cap is in place. Set it up so
18491 				 * when we want less we can retry.
18492 				 */
18493 				tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
18494 				rack->r_ctl.crte = NULL;
18495 				rack->rack_attempt_hdwr_pace = 0;
18496 				rack->rack_hdrw_pacing = 0;
18497 			}
18498 		}
18499 		if ((rack->r_ctl.crte != NULL) && (rack->rc_inp->inp_snd_tag == NULL)) {
18500 			/*
18501 			 * We lost our rate somehow, this can happen
18502 			 * if the interface changed underneath us.
18503 			 */
18504 			tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
18505 			rack->r_ctl.crte = NULL;
18506 			/* Lets re-allow attempting to setup pacing */
18507 			rack->rack_hdrw_pacing = 0;
18508 			rack->rack_attempt_hdwr_pace = 0;
18509 			rack_log_hdwr_pacing(rack,
18510 					     rate_wanted, bw_est, __LINE__,
18511 					     0, 6);
18512 		}
18513 		prev_fill = rack->r_via_fill_cw;
18514 		if ((rack->rc_pace_to_cwnd) &&
18515 		    (capped == 0) &&
18516 		    (rack->dgp_on == 1) &&
18517 		    (rack->use_fixed_rate == 0) &&
18518 		    (rack->in_probe_rtt == 0) &&
18519 		    (IN_FASTRECOVERY(rack->rc_tp->t_flags) == 0)) {
18520 			/*
18521 			 * We want to pace at our rate *or* faster to
18522 			 * fill the cwnd to the max if its not full.
18523 			 */
18524 			slot = pace_to_fill_cwnd(rack, slot, (len+segs), segsiz, &capped, &rate_wanted, 0);
18525 			/* Re-check to make sure we are not exceeding our max b/w */
18526 			if ((rack->r_ctl.crte != NULL) &&
18527 			    (tcp_hw_highest_rate(rack->r_ctl.crte) < rate_wanted)) {
18528 				/*
18529 				 * We want more than the hardware can give us,
18530 				 * don't start any hw pacing.
18531 				 */
18532 				can_start_hw_pacing = 0;
18533 				if (rack->r_rack_hw_rate_caps == 0) {
18534 					/*
18535 					 * Ok we need to release it, we
18536 					 * want more than the card can give us and
18537 					 * no rate cap is in place. Set it up so
18538 					 * when we want less we can retry.
18539 					 */
18540 					tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
18541 					rack->r_ctl.crte = NULL;
18542 					rack->rack_attempt_hdwr_pace = 0;
18543 					rack->rack_hdrw_pacing = 0;
18544 					rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
18545 				}
18546 			}
18547 		}
18548 		if ((rack->rc_inp->inp_route.ro_nh != NULL) &&
18549 		    (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
18550 			if ((rack->rack_hdw_pace_ena) &&
18551 			    (can_start_hw_pacing > 0) &&
18552 			    (rack->rack_hdrw_pacing == 0) &&
18553 			    (rack->rack_attempt_hdwr_pace == 0)) {
18554 				/*
18555 				 * Lets attempt to turn on hardware pacing
18556 				 * if we can.
18557 				 */
18558 				rack->rack_attempt_hdwr_pace = 1;
18559 				rack->r_ctl.crte = tcp_set_pacing_rate(rack->rc_tp,
18560 								       rack->rc_inp->inp_route.ro_nh->nh_ifp,
18561 								       rate_wanted,
18562 								       RS_PACING_GEQ,
18563 								       &err, &rack->r_ctl.crte_prev_rate);
18564 				if (rack->r_ctl.crte) {
18565 					rack->rack_hdrw_pacing = 1;
18566 					rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size_w_divisor(tp, rate_wanted, segsiz,
18567 													   pace_one, rack->r_ctl.crte,
18568 													   NULL, rack->r_ctl.pace_len_divisor);
18569 					rack_log_hdwr_pacing(rack,
18570 							     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
18571 							     err, 0);
18572 					rack->r_ctl.last_hw_bw_req = rate_wanted;
18573 				} else {
18574 					counter_u64_add(rack_hw_pace_init_fail, 1);
18575 				}
18576 			} else if (rack->rack_hdrw_pacing &&
18577 				   (rack->r_ctl.last_hw_bw_req != rate_wanted)) {
18578 				/* Do we need to adjust our rate? */
18579 				const struct tcp_hwrate_limit_table *nrte;
18580 
18581 				if (rack->r_up_only &&
18582 				    (rate_wanted < rack->r_ctl.crte->rate)) {
18583 					/**
18584 					 * We have four possible states here
18585 					 * having to do with the previous time
18586 					 * and this time.
18587 					 *   previous  |  this-time
18588 					 * A)     0      |     0   -- fill_cw not in the picture
18589 					 * B)     1      |     0   -- we were doing a fill-cw but now are not
18590 					 * C)     1      |     1   -- all rates from fill_cw
18591 					 * D)     0      |     1   -- we were doing non-fill and now we are filling
18592 					 *
18593 					 * For case A, C and D we don't allow a drop. But for
18594 					 * case B where we now our on our steady rate we do
18595 					 * allow a drop.
18596 					 *
18597 					 */
18598 					if (!((prev_fill == 1) && (rack->r_via_fill_cw == 0)))
18599 						goto done_w_hdwr;
18600 				}
18601 				if ((rate_wanted > rack->r_ctl.crte->rate) ||
18602 				    (rate_wanted <= rack->r_ctl.crte_prev_rate)) {
18603 					if (rack_hw_rate_to_low &&
18604 					    (bw_est < rack_hw_rate_to_low)) {
18605 						/*
18606 						 * The pacing rate is too low for hardware, but
18607 						 * do allow hardware pacing to be restarted.
18608 						 */
18609 						rack_log_hdwr_pacing(rack,
18610 								     bw_est, rack->r_ctl.crte->rate, __LINE__,
18611 								     0, 5);
18612 						tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
18613 						rack->r_ctl.crte = NULL;
18614 						rack->rack_attempt_hdwr_pace = 0;
18615 						rack->rack_hdrw_pacing = 0;
18616 						rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
18617 						goto done_w_hdwr;
18618 					}
18619 					nrte = tcp_chg_pacing_rate(rack->r_ctl.crte,
18620 								   rack->rc_tp,
18621 								   rack->rc_inp->inp_route.ro_nh->nh_ifp,
18622 								   rate_wanted,
18623 								   RS_PACING_GEQ,
18624 								   &err, &rack->r_ctl.crte_prev_rate);
18625 					if (nrte == NULL) {
18626 						/*
18627 						 * Lost the rate, lets drop hardware pacing
18628 						 * period.
18629 						 */
18630 						rack->rack_hdrw_pacing = 0;
18631 						rack->r_ctl.crte = NULL;
18632 						rack_log_hdwr_pacing(rack,
18633 								     rate_wanted, 0, __LINE__,
18634 								     err, 1);
18635 						rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
18636 						counter_u64_add(rack_hw_pace_lost, 1);
18637 					} else if (nrte != rack->r_ctl.crte) {
18638 						rack->r_ctl.crte = nrte;
18639 						rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size_w_divisor(tp, rate_wanted,
18640 														   segsiz, pace_one, rack->r_ctl.crte,
18641 														   NULL, rack->r_ctl.pace_len_divisor);
18642 						rack_log_hdwr_pacing(rack,
18643 								     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
18644 								     err, 2);
18645 						rack->r_ctl.last_hw_bw_req = rate_wanted;
18646 					}
18647 				} else {
18648 					/* We just need to adjust the segment size */
18649 					rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
18650 					rack_log_hdwr_pacing(rack,
18651 							     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
18652 							     0, 4);
18653 					rack->r_ctl.last_hw_bw_req = rate_wanted;
18654 				}
18655 			}
18656 		}
18657 		if (minslot && (minslot > slot)) {
18658 			rack_log_pacing_delay_calc(rack, minslot, slot, rack->r_ctl.crte->rate, bw_est, lentim,
18659 						   98, __LINE__, NULL, 0);
18660 			slot = minslot;
18661 		}
18662 	done_w_hdwr:
18663 		if (rack_limit_time_with_srtt &&
18664 		    (rack->use_fixed_rate == 0) &&
18665 		    (rack->rack_hdrw_pacing == 0)) {
18666 			/*
18667 			 * Sanity check, we do not allow the pacing delay
18668 			 * to be longer than the SRTT of the path. If it is
18669 			 * a slow path, then adding a packet should increase
18670 			 * the RTT and compensate for this i.e. the srtt will
18671 			 * be greater so the allowed pacing time will be greater.
18672 			 *
18673 			 * Note this restriction is not for where a peak rate
18674 			 * is set, we are doing fixed pacing or hardware pacing.
18675 			 */
18676 			if (rack->rc_tp->t_srtt)
18677 				srtt = rack->rc_tp->t_srtt;
18678 			else
18679 				srtt = RACK_INITIAL_RTO * HPTS_USEC_IN_MSEC;	/* its in ms convert */
18680 			if (srtt < (uint64_t)slot) {
18681 				rack_log_pacing_delay_calc(rack, srtt, slot, rate_wanted, bw_est, lentim, 99, __LINE__, NULL, 0);
18682 				slot = srtt;
18683 			}
18684 		}
18685 		/*******************************************************************/
18686 		/* RRS: We insert paced call to stats here for len and rate_wanted */
18687 		/*******************************************************************/
18688 		rack_log_pacing_delay_calc(rack, len, slot, rate_wanted, bw_est, lentim, 2, __LINE__, rsm, 0);
18689 	}
18690 	if (rack->r_ctl.crte && (rack->r_ctl.crte->rs_num_enobufs > 0)) {
18691 		/*
18692 		 * If this rate is seeing enobufs when it
18693 		 * goes to send then either the nic is out
18694 		 * of gas or we are mis-estimating the time
18695 		 * somehow and not letting the queue empty
18696 		 * completely. Lets add to the pacing time.
18697 		 */
18698 		int hw_boost_delay;
18699 
18700 		hw_boost_delay = rack->r_ctl.crte->time_between * rack_enobuf_hw_boost_mult;
18701 		if (hw_boost_delay > rack_enobuf_hw_max)
18702 			hw_boost_delay = rack_enobuf_hw_max;
18703 		else if (hw_boost_delay < rack_enobuf_hw_min)
18704 			hw_boost_delay = rack_enobuf_hw_min;
18705 		slot += hw_boost_delay;
18706 	}
18707 	return (slot);
18708 }
18709 
18710 static void
rack_start_gp_measurement(struct tcpcb * tp,struct tcp_rack * rack,tcp_seq startseq,uint32_t sb_offset)18711 rack_start_gp_measurement(struct tcpcb *tp, struct tcp_rack *rack,
18712     tcp_seq startseq, uint32_t sb_offset)
18713 {
18714 	struct rack_sendmap *my_rsm = NULL;
18715 
18716 	if (tp->t_state < TCPS_ESTABLISHED) {
18717 		/*
18718 		 * We don't start any measurements if we are
18719 		 * not at least established.
18720 		 */
18721 		return;
18722 	}
18723 	if (tp->t_state >= TCPS_FIN_WAIT_1) {
18724 		/*
18725 		 * We will get no more data into the SB
18726 		 * this means we need to have the data available
18727 		 * before we start a measurement.
18728 		 */
18729 
18730 		if (sbavail(&tptosocket(tp)->so_snd) <
18731 		    max(rc_init_window(rack),
18732 			(MIN_GP_WIN * ctf_fixed_maxseg(tp)))) {
18733 			/* Nope not enough data */
18734 			return;
18735 		}
18736 	}
18737 	tp->t_flags |= TF_GPUTINPROG;
18738 	rack->r_ctl.rc_gp_cumack_ts = 0;
18739 	rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
18740 	rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
18741 	tp->gput_seq = startseq;
18742 	rack->app_limited_needs_set = 0;
18743 	if (rack->in_probe_rtt)
18744 		rack->measure_saw_probe_rtt = 1;
18745 	else if ((rack->measure_saw_probe_rtt) &&
18746 		 (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
18747 		rack->measure_saw_probe_rtt = 0;
18748 	if (rack->rc_gp_filled)
18749 		tp->gput_ts = rack->r_ctl.last_cumack_advance;
18750 	else {
18751 		/* Special case initial measurement */
18752 		struct timeval tv;
18753 
18754 		tp->gput_ts = tcp_get_usecs(&tv);
18755 		rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
18756 	}
18757 	/*
18758 	 * We take a guess out into the future,
18759 	 * if we have no measurement and no
18760 	 * initial rate, we measure the first
18761 	 * initial-windows worth of data to
18762 	 * speed up getting some GP measurement and
18763 	 * thus start pacing.
18764 	 */
18765 	if ((rack->rc_gp_filled == 0) && (rack->r_ctl.init_rate == 0)) {
18766 		rack->app_limited_needs_set = 1;
18767 		tp->gput_ack = startseq + max(rc_init_window(rack),
18768 					      (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
18769 		rack_log_pacing_delay_calc(rack,
18770 					   tp->gput_seq,
18771 					   tp->gput_ack,
18772 					   0,
18773 					   tp->gput_ts,
18774 					   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) | (uint64_t)rack->r_ctl.rc_gp_output_ts),
18775 					   9,
18776 					   __LINE__, NULL, 0);
18777 		rack_tend_gp_marks(tp, rack);
18778 		rack_log_gpset(rack, tp->gput_ack, 0, 0, __LINE__, 1, NULL);
18779 		return;
18780 	}
18781 	if (sb_offset) {
18782 		/*
18783 		 * We are out somewhere in the sb
18784 		 * can we use the already outstanding data?
18785 		 */
18786 
18787 		if (rack->r_ctl.rc_app_limited_cnt == 0) {
18788 			/*
18789 			 * Yes first one is good and in this case
18790 			 * the tp->gput_ts is correctly set based on
18791 			 * the last ack that arrived (no need to
18792 			 * set things up when an ack comes in).
18793 			 */
18794 			my_rsm = tqhash_min(rack->r_ctl.tqh);
18795 			if ((my_rsm == NULL) ||
18796 			    (my_rsm->r_rtr_cnt != 1)) {
18797 				/* retransmission? */
18798 				goto use_latest;
18799 			}
18800 		} else {
18801 			if (rack->r_ctl.rc_first_appl == NULL) {
18802 				/*
18803 				 * If rc_first_appl is NULL
18804 				 * then the cnt should be 0.
18805 				 * This is probably an error, maybe
18806 				 * a KASSERT would be approprate.
18807 				 */
18808 				goto use_latest;
18809 			}
18810 			/*
18811 			 * If we have a marker pointer to the last one that is
18812 			 * app limited we can use that, but we need to set
18813 			 * things up so that when it gets ack'ed we record
18814 			 * the ack time (if its not already acked).
18815 			 */
18816 			rack->app_limited_needs_set = 1;
18817 			/*
18818 			 * We want to get to the rsm that is either
18819 			 * next with space i.e. over 1 MSS or the one
18820 			 * after that (after the app-limited).
18821 			 */
18822 			my_rsm = tqhash_next(rack->r_ctl.tqh, rack->r_ctl.rc_first_appl);
18823 			if (my_rsm) {
18824 				if ((my_rsm->r_end - my_rsm->r_start) <= ctf_fixed_maxseg(tp))
18825 					/* Have to use the next one */
18826 					my_rsm = tqhash_next(rack->r_ctl.tqh, my_rsm);
18827 				else {
18828 					/* Use after the first MSS of it is acked */
18829 					tp->gput_seq = my_rsm->r_start + ctf_fixed_maxseg(tp);
18830 					goto start_set;
18831 				}
18832 			}
18833 			if ((my_rsm == NULL) ||
18834 			    (my_rsm->r_rtr_cnt != 1)) {
18835 				/*
18836 				 * Either its a retransmit or
18837 				 * the last is the app-limited one.
18838 				 */
18839 				goto use_latest;
18840 			}
18841 		}
18842 		tp->gput_seq = my_rsm->r_start;
18843 start_set:
18844 		if (my_rsm->r_flags & RACK_ACKED) {
18845 			/*
18846 			 * This one has been acked use the arrival ack time
18847 			 */
18848 			struct rack_sendmap *nrsm;
18849 
18850 			tp->gput_ts = (uint32_t)my_rsm->r_ack_arrival;
18851 			rack->app_limited_needs_set = 0;
18852 			/*
18853 			 * Ok in this path we need to use the r_end now
18854 			 * since this guy is the starting ack.
18855 			 */
18856 			tp->gput_seq = my_rsm->r_end;
18857 			/*
18858 			 * We also need to adjust up the sendtime
18859 			 * to the send of the next data after my_rsm.
18860 			 */
18861 			nrsm = tqhash_next(rack->r_ctl.tqh, my_rsm);
18862 			if (nrsm != NULL)
18863 				my_rsm = nrsm;
18864 			else {
18865 				/*
18866 				 * The next as not been sent, thats the
18867 				 * case for using the latest.
18868 				 */
18869 				goto use_latest;
18870 			}
18871 		}
18872 		rack->r_ctl.rc_gp_output_ts = my_rsm->r_tim_lastsent[0];
18873 		tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
18874 		rack->r_ctl.rc_gp_cumack_ts = 0;
18875 		if ((rack->r_ctl.cleared_app_ack == 1) &&
18876 		    (SEQ_GEQ(rack->r_ctl.cleared_app_ack, tp->gput_seq))) {
18877 			/*
18878 			 * We just cleared an application limited period
18879 			 * so the next seq out needs to skip the first
18880 			 * ack.
18881 			 */
18882 			rack->app_limited_needs_set = 1;
18883 			rack->r_ctl.cleared_app_ack = 0;
18884 		}
18885 		rack_log_pacing_delay_calc(rack,
18886 					   tp->gput_seq,
18887 					   tp->gput_ack,
18888 					   (uint64_t)my_rsm,
18889 					   tp->gput_ts,
18890 					   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) | (uint64_t)rack->r_ctl.rc_gp_output_ts),
18891 					   9,
18892 					   __LINE__, my_rsm, 0);
18893 		/* Now lets make sure all are marked as they should be */
18894 		rack_tend_gp_marks(tp, rack);
18895 		rack_log_gpset(rack, tp->gput_ack, 0, 0, __LINE__, 1, NULL);
18896 		return;
18897 	}
18898 
18899 use_latest:
18900 	/*
18901 	 * We don't know how long we may have been
18902 	 * idle or if this is the first-send. Lets
18903 	 * setup the flag so we will trim off
18904 	 * the first ack'd data so we get a true
18905 	 * measurement.
18906 	 */
18907 	rack->app_limited_needs_set = 1;
18908 	tp->gput_ack = startseq + rack_get_measure_window(tp, rack);
18909 	rack->r_ctl.rc_gp_cumack_ts = 0;
18910 	/* Find this guy so we can pull the send time */
18911 	my_rsm = tqhash_find(rack->r_ctl.tqh, startseq);
18912 	if (my_rsm) {
18913 		rack->r_ctl.rc_gp_output_ts = my_rsm->r_tim_lastsent[0];
18914 		if (my_rsm->r_flags & RACK_ACKED) {
18915 			/*
18916 			 * Unlikely since its probably what was
18917 			 * just transmitted (but I am paranoid).
18918 			 */
18919 			tp->gput_ts = (uint32_t)my_rsm->r_ack_arrival;
18920 			rack->app_limited_needs_set = 0;
18921 		}
18922 		if (SEQ_LT(my_rsm->r_start, tp->gput_seq)) {
18923 			/* This also is unlikely */
18924 			tp->gput_seq = my_rsm->r_start;
18925 		}
18926 	} else {
18927 		/*
18928 		 * TSNH unless we have some send-map limit,
18929 		 * and even at that it should not be hitting
18930 		 * that limit (we should have stopped sending).
18931 		 */
18932 		struct timeval tv;
18933 
18934 		microuptime(&tv);
18935 		rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
18936 	}
18937 	rack_tend_gp_marks(tp, rack);
18938 	rack_log_pacing_delay_calc(rack,
18939 				   tp->gput_seq,
18940 				   tp->gput_ack,
18941 				   (uint64_t)my_rsm,
18942 				   tp->gput_ts,
18943 				   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) | (uint64_t)rack->r_ctl.rc_gp_output_ts),
18944 				   9, __LINE__, NULL, 0);
18945 	rack_log_gpset(rack, tp->gput_ack, 0, 0, __LINE__, 1, NULL);
18946 }
18947 
18948 static inline uint32_t
rack_what_can_we_send(struct tcpcb * tp,struct tcp_rack * rack,uint32_t cwnd_to_use,uint32_t avail,int32_t sb_offset)18949 rack_what_can_we_send(struct tcpcb *tp, struct tcp_rack *rack,  uint32_t cwnd_to_use,
18950     uint32_t avail, int32_t sb_offset)
18951 {
18952 	uint32_t len;
18953 	uint32_t sendwin;
18954 
18955 	if (tp->snd_wnd > cwnd_to_use)
18956 		sendwin = cwnd_to_use;
18957 	else
18958 		sendwin = tp->snd_wnd;
18959 	if (ctf_outstanding(tp) >= tp->snd_wnd) {
18960 		/* We never want to go over our peers rcv-window */
18961 		len = 0;
18962 	} else {
18963 		uint32_t flight;
18964 
18965 		flight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
18966 		if (flight >= sendwin) {
18967 			/*
18968 			 * We have in flight what we are allowed by cwnd (if
18969 			 * it was rwnd blocking it would have hit above out
18970 			 * >= tp->snd_wnd).
18971 			 */
18972 			return (0);
18973 		}
18974 		len = sendwin - flight;
18975 		if ((len + ctf_outstanding(tp)) > tp->snd_wnd) {
18976 			/* We would send too much (beyond the rwnd) */
18977 			len = tp->snd_wnd - ctf_outstanding(tp);
18978 		}
18979 		if ((len + sb_offset) > avail) {
18980 			/*
18981 			 * We don't have that much in the SB, how much is
18982 			 * there?
18983 			 */
18984 			len = avail - sb_offset;
18985 		}
18986 	}
18987 	return (len);
18988 }
18989 
18990 static void
rack_log_fsb(struct tcp_rack * rack,struct tcpcb * tp,struct socket * so,uint32_t flags,unsigned ipoptlen,int32_t orig_len,int32_t len,int error,int rsm_is_null,int optlen,int line,uint16_t mode)18991 rack_log_fsb(struct tcp_rack *rack, struct tcpcb *tp, struct socket *so, uint32_t flags,
18992 	     unsigned ipoptlen, int32_t orig_len, int32_t len, int error,
18993 	     int rsm_is_null, int optlen, int line, uint16_t mode)
18994 {
18995 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
18996 		union tcp_log_stackspecific log;
18997 		struct timeval tv;
18998 
18999 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
19000 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
19001 		log.u_bbr.flex1 = error;
19002 		log.u_bbr.flex2 = flags;
19003 		log.u_bbr.flex3 = rsm_is_null;
19004 		log.u_bbr.flex4 = ipoptlen;
19005 		log.u_bbr.flex5 = tp->rcv_numsacks;
19006 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
19007 		log.u_bbr.flex7 = optlen;
19008 		log.u_bbr.flex8 = rack->r_fsb_inited;
19009 		log.u_bbr.applimited = rack->r_fast_output;
19010 		log.u_bbr.bw_inuse = rack_get_bw(rack);
19011 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
19012 		log.u_bbr.cwnd_gain = mode;
19013 		log.u_bbr.pkts_out = orig_len;
19014 		log.u_bbr.lt_epoch = len;
19015 		log.u_bbr.delivered = line;
19016 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
19017 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
19018 		tcp_log_event(tp, NULL, &so->so_rcv, &so->so_snd, TCP_LOG_FSB, 0,
19019 			       len, &log, false, NULL, __func__, __LINE__, &tv);
19020 	}
19021 }
19022 
19023 
19024 static struct mbuf *
rack_fo_base_copym(struct mbuf * the_m,uint32_t the_off,int32_t * plen,struct rack_fast_send_blk * fsb,int32_t seglimit,int32_t segsize,int hw_tls)19025 rack_fo_base_copym(struct mbuf *the_m, uint32_t the_off, int32_t *plen,
19026 		   struct rack_fast_send_blk *fsb,
19027 		   int32_t seglimit, int32_t segsize, int hw_tls)
19028 {
19029 #ifdef KERN_TLS
19030 	struct ktls_session *tls, *ntls;
19031 #ifdef INVARIANTS
19032 	struct mbuf *start;
19033 #endif
19034 #endif
19035 	struct mbuf *m, *n, **np, *smb;
19036 	struct mbuf *top;
19037 	int32_t off, soff;
19038 	int32_t len = *plen;
19039 	int32_t fragsize;
19040 	int32_t len_cp = 0;
19041 	uint32_t mlen, frags;
19042 
19043 	soff = off = the_off;
19044 	smb = m = the_m;
19045 	np = &top;
19046 	top = NULL;
19047 #ifdef KERN_TLS
19048 	if (hw_tls && (m->m_flags & M_EXTPG))
19049 		tls = m->m_epg_tls;
19050 	else
19051 		tls = NULL;
19052 #ifdef INVARIANTS
19053 	start = m;
19054 #endif
19055 #endif
19056 	while (len > 0) {
19057 		if (m == NULL) {
19058 			*plen = len_cp;
19059 			break;
19060 		}
19061 #ifdef KERN_TLS
19062 		if (hw_tls) {
19063 			if (m->m_flags & M_EXTPG)
19064 				ntls = m->m_epg_tls;
19065 			else
19066 				ntls = NULL;
19067 
19068 			/*
19069 			 * Avoid mixing TLS records with handshake
19070 			 * data or TLS records from different
19071 			 * sessions.
19072 			 */
19073 			if (tls != ntls) {
19074 				MPASS(m != start);
19075 				*plen = len_cp;
19076 				break;
19077 			}
19078 		}
19079 #endif
19080 		mlen = min(len, m->m_len - off);
19081 		if (seglimit) {
19082 			/*
19083 			 * For M_EXTPG mbufs, add 3 segments
19084 			 * + 1 in case we are crossing page boundaries
19085 			 * + 2 in case the TLS hdr/trailer are used
19086 			 * It is cheaper to just add the segments
19087 			 * than it is to take the cache miss to look
19088 			 * at the mbuf ext_pgs state in detail.
19089 			 */
19090 			if (m->m_flags & M_EXTPG) {
19091 				fragsize = min(segsize, PAGE_SIZE);
19092 				frags = 3;
19093 			} else {
19094 				fragsize = segsize;
19095 				frags = 0;
19096 			}
19097 
19098 			/* Break if we really can't fit anymore. */
19099 			if ((frags + 1) >= seglimit) {
19100 				*plen =	len_cp;
19101 				break;
19102 			}
19103 
19104 			/*
19105 			 * Reduce size if you can't copy the whole
19106 			 * mbuf. If we can't copy the whole mbuf, also
19107 			 * adjust len so the loop will end after this
19108 			 * mbuf.
19109 			 */
19110 			if ((frags + howmany(mlen, fragsize)) >= seglimit) {
19111 				mlen = (seglimit - frags - 1) * fragsize;
19112 				len = mlen;
19113 				*plen = len_cp + len;
19114 			}
19115 			frags += howmany(mlen, fragsize);
19116 			if (frags == 0)
19117 				frags++;
19118 			seglimit -= frags;
19119 			KASSERT(seglimit > 0,
19120 			    ("%s: seglimit went too low", __func__));
19121 		}
19122 		n = m_get(M_NOWAIT, m->m_type);
19123 		*np = n;
19124 		if (n == NULL)
19125 			goto nospace;
19126 		n->m_len = mlen;
19127 		soff += mlen;
19128 		len_cp += n->m_len;
19129 		if (m->m_flags & (M_EXT | M_EXTPG)) {
19130 			n->m_data = m->m_data + off;
19131 			mb_dupcl(n, m);
19132 		} else {
19133 			bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t),
19134 			    (u_int)n->m_len);
19135 		}
19136 		len -= n->m_len;
19137 		off = 0;
19138 		m = m->m_next;
19139 		np = &n->m_next;
19140 		if (len || (soff == smb->m_len)) {
19141 			/*
19142 			 * We have more so we move forward  or
19143 			 * we have consumed the entire mbuf and
19144 			 * len has fell to 0.
19145 			 */
19146 			soff = 0;
19147 			smb = m;
19148 		}
19149 
19150 	}
19151 	if (fsb != NULL) {
19152 		fsb->m = smb;
19153 		fsb->off = soff;
19154 		if (smb) {
19155 			/*
19156 			 * Save off the size of the mbuf. We do
19157 			 * this so that we can recognize when it
19158 			 * has been trimmed by sbcut() as acks
19159 			 * come in.
19160 			 */
19161 			fsb->o_m_len = smb->m_len;
19162 			fsb->o_t_len = M_TRAILINGROOM(smb);
19163 		} else {
19164 			/*
19165 			 * This is the case where the next mbuf went to NULL. This
19166 			 * means with this copy we have sent everything in the sb.
19167 			 * In theory we could clear the fast_output flag, but lets
19168 			 * not since its possible that we could get more added
19169 			 * and acks that call the extend function which would let
19170 			 * us send more.
19171 			 */
19172 			fsb->o_m_len = 0;
19173 			fsb->o_t_len = 0;
19174 		}
19175 	}
19176 	return (top);
19177 nospace:
19178 	if (top)
19179 		m_freem(top);
19180 	return (NULL);
19181 
19182 }
19183 
19184 /*
19185  * This is a copy of m_copym(), taking the TSO segment size/limit
19186  * constraints into account, and advancing the sndptr as it goes.
19187  */
19188 static struct mbuf *
rack_fo_m_copym(struct tcp_rack * rack,int32_t * plen,int32_t seglimit,int32_t segsize,struct mbuf ** s_mb,int * s_soff)19189 rack_fo_m_copym(struct tcp_rack *rack, int32_t *plen,
19190 		int32_t seglimit, int32_t segsize, struct mbuf **s_mb, int *s_soff)
19191 {
19192 	struct mbuf *m, *n;
19193 	int32_t soff;
19194 
19195 	m = rack->r_ctl.fsb.m;
19196 	if (M_TRAILINGROOM(m) != rack->r_ctl.fsb.o_t_len) {
19197 		/*
19198 		 * The trailing space changed, mbufs can grow
19199 		 * at the tail but they can't shrink from
19200 		 * it, KASSERT that. Adjust the orig_m_len to
19201 		 * compensate for this change.
19202 		 */
19203 		KASSERT((rack->r_ctl.fsb.o_t_len > M_TRAILINGROOM(m)),
19204 			("mbuf:%p rack:%p trailing_space:%jd ots:%u oml:%u mlen:%u\n",
19205 			 m,
19206 			 rack,
19207 			 (intmax_t)M_TRAILINGROOM(m),
19208 			 rack->r_ctl.fsb.o_t_len,
19209 			 rack->r_ctl.fsb.o_m_len,
19210 			 m->m_len));
19211 		rack->r_ctl.fsb.o_m_len += (rack->r_ctl.fsb.o_t_len - M_TRAILINGROOM(m));
19212 		rack->r_ctl.fsb.o_t_len = M_TRAILINGROOM(m);
19213 	}
19214 	if (m->m_len < rack->r_ctl.fsb.o_m_len) {
19215 		/*
19216 		 * Mbuf shrank, trimmed off the top by an ack, our
19217 		 * offset changes.
19218 		 */
19219 		KASSERT((rack->r_ctl.fsb.off >= (rack->r_ctl.fsb.o_m_len - m->m_len)),
19220 			("mbuf:%p len:%u rack:%p oml:%u soff:%u\n",
19221 			 m, m->m_len,
19222 			 rack, rack->r_ctl.fsb.o_m_len,
19223 			 rack->r_ctl.fsb.off));
19224 
19225 		if (rack->r_ctl.fsb.off >= (rack->r_ctl.fsb.o_m_len- m->m_len))
19226 			rack->r_ctl.fsb.off -= (rack->r_ctl.fsb.o_m_len - m->m_len);
19227 		else
19228 			rack->r_ctl.fsb.off = 0;
19229 		rack->r_ctl.fsb.o_m_len = m->m_len;
19230 #ifdef INVARIANTS
19231 	} else if (m->m_len > rack->r_ctl.fsb.o_m_len) {
19232 		panic("rack:%p m:%p m_len grew outside of t_space compensation",
19233 		      rack, m);
19234 #endif
19235 	}
19236 	soff = rack->r_ctl.fsb.off;
19237 	KASSERT(soff >= 0, ("%s, negative off %d", __FUNCTION__, soff));
19238 	KASSERT(*plen >= 0, ("%s, negative len %d", __FUNCTION__, *plen));
19239 	KASSERT(soff < m->m_len, ("%s rack:%p len:%u m:%p m->m_len:%u < off?",
19240 				 __FUNCTION__,
19241 				 rack, *plen, m, m->m_len));
19242 	/* Save off the right location before we copy and advance */
19243 	*s_soff = soff;
19244 	*s_mb = rack->r_ctl.fsb.m;
19245 	n = rack_fo_base_copym(m, soff, plen,
19246 			       &rack->r_ctl.fsb,
19247 			       seglimit, segsize, rack->r_ctl.fsb.hw_tls);
19248 	return (n);
19249 }
19250 
19251 /* Log the buffer level */
19252 static void
rack_log_queue_level(struct tcpcb * tp,struct tcp_rack * rack,int len,struct timeval * tv,uint32_t cts)19253 rack_log_queue_level(struct tcpcb *tp, struct tcp_rack *rack,
19254 		     int len, struct timeval *tv,
19255 		     uint32_t cts)
19256 {
19257 	uint32_t p_rate = 0, p_queue = 0, err = 0;
19258 	union tcp_log_stackspecific log;
19259 
19260 #ifdef RATELIMIT
19261 	err = in_pcbquery_txrlevel(rack->rc_inp, &p_queue);
19262 	err = in_pcbquery_txrtlmt(rack->rc_inp,	&p_rate);
19263 #endif
19264 	memset(&log.u_bbr, 0, sizeof(log.u_bbr));
19265 	log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
19266 	log.u_bbr.flex1 = p_rate;
19267 	log.u_bbr.flex2 = p_queue;
19268 	log.u_bbr.flex4 = (uint32_t)rack->r_ctl.crte->using;
19269 	log.u_bbr.flex5 = (uint32_t)rack->r_ctl.crte->rs_num_enobufs;
19270 	log.u_bbr.flex6 = rack->r_ctl.crte->time_between;
19271 	log.u_bbr.flex7 = 99;
19272 	log.u_bbr.flex8 = 0;
19273 	log.u_bbr.pkts_out = err;
19274 	log.u_bbr.delRate = rack->r_ctl.crte->rate;
19275 	log.u_bbr.timeStamp = cts;
19276 	log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
19277 	tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_HDWR_PACE, 0,
19278 		       len, &log, false, NULL, __func__, __LINE__, tv);
19279 
19280 }
19281 
19282 static uint32_t
rack_check_queue_level(struct tcp_rack * rack,struct tcpcb * tp,struct timeval * tv,uint32_t cts,int len,uint32_t segsiz)19283 rack_check_queue_level(struct tcp_rack *rack, struct tcpcb *tp,
19284 		       struct timeval *tv, uint32_t cts, int len, uint32_t segsiz)
19285 {
19286 	uint64_t lentime = 0;
19287 #ifdef RATELIMIT
19288 	uint32_t p_rate = 0, p_queue = 0, err;
19289 	union tcp_log_stackspecific log;
19290 	uint64_t bw;
19291 
19292 	err = in_pcbquery_txrlevel(rack->rc_inp, &p_queue);
19293 	/* Failed or queue is zero */
19294 	if (err || (p_queue == 0)) {
19295 		lentime = 0;
19296 		goto out;
19297 	}
19298 	err = in_pcbquery_txrtlmt(rack->rc_inp, &p_rate);
19299 	if (err) {
19300 		lentime = 0;
19301 		goto out;
19302 	}
19303 	/*
19304 	 * If we reach here we have some bytes in
19305 	 * the queue. The number returned is a value
19306 	 * between 0 and 0xffff where ffff is full
19307 	 * and 0 is empty. So how best to make this into
19308 	 * something usable?
19309 	 *
19310 	 * The "safer" way is lets take the b/w gotten
19311 	 * from the query (which should be our b/w rate)
19312 	 * and pretend that a full send (our rc_pace_max_segs)
19313 	 * is outstanding. We factor it so its as if a full
19314 	 * number of our MSS segment is terms of full
19315 	 * ethernet segments are outstanding.
19316 	 */
19317 	bw = p_rate / 8;
19318 	if (bw) {
19319 		lentime = (rack->r_ctl.rc_pace_max_segs / segsiz);
19320 		lentime *= ETHERNET_SEGMENT_SIZE;
19321 		lentime *= (uint64_t)HPTS_USEC_IN_SEC;
19322 		lentime /= bw;
19323 	} else {
19324 		/* TSNH -- KASSERT? */
19325 		lentime = 0;
19326 	}
19327 out:
19328 	if (tcp_bblogging_on(tp)) {
19329 		memset(&log, 0, sizeof(log));
19330 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
19331 		log.u_bbr.flex1 = p_rate;
19332 		log.u_bbr.flex2 = p_queue;
19333 		log.u_bbr.flex4 = (uint32_t)rack->r_ctl.crte->using;
19334 		log.u_bbr.flex5 = (uint32_t)rack->r_ctl.crte->rs_num_enobufs;
19335 		log.u_bbr.flex6 = rack->r_ctl.crte->time_between;
19336 		log.u_bbr.flex7 = 99;
19337 		log.u_bbr.flex8 = 0;
19338 		log.u_bbr.pkts_out = err;
19339 		log.u_bbr.delRate = rack->r_ctl.crte->rate;
19340 		log.u_bbr.cur_del_rate = lentime;
19341 		log.u_bbr.timeStamp = cts;
19342 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
19343 		tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_HDWR_PACE, 0,
19344 			       len, &log, false, NULL, __func__, __LINE__,tv);
19345 	}
19346 #endif
19347 	return ((uint32_t)lentime);
19348 }
19349 
19350 static int
rack_fast_rsm_output(struct tcpcb * tp,struct tcp_rack * rack,struct rack_sendmap * rsm,uint64_t ts_val,uint32_t cts,uint32_t ms_cts,struct timeval * tv,int len,uint8_t doing_tlp)19351 rack_fast_rsm_output(struct tcpcb *tp, struct tcp_rack *rack, struct rack_sendmap *rsm,
19352 		     uint64_t ts_val, uint32_t cts, uint32_t ms_cts, struct timeval *tv, int len, uint8_t doing_tlp)
19353 {
19354 	/*
19355 	 * Enter the fast retransmit path. We are given that a sched_pin is
19356 	 * in place (if accounting is compliled in) and the cycle count taken
19357 	 * at the entry is in the ts_val. The concept her is that the rsm
19358 	 * now holds the mbuf offsets and such so we can directly transmit
19359 	 * without a lot of overhead, the len field is already set for
19360 	 * us to prohibit us from sending too much (usually its 1MSS).
19361 	 */
19362 	struct ip *ip = NULL;
19363 	struct udphdr *udp = NULL;
19364 	struct tcphdr *th = NULL;
19365 	struct mbuf *m = NULL;
19366 	struct inpcb *inp;
19367 	uint8_t *cpto;
19368 	struct tcp_log_buffer *lgb;
19369 #ifdef TCP_ACCOUNTING
19370 	uint64_t crtsc;
19371 	int cnt_thru = 1;
19372 #endif
19373 	struct tcpopt to;
19374 	u_char opt[TCP_MAXOLEN];
19375 	uint32_t hdrlen, optlen;
19376 	int32_t slot, segsiz, max_val, tso = 0, error = 0, ulen = 0;
19377 	uint16_t flags;
19378 	uint32_t if_hw_tsomaxsegcount = 0, startseq;
19379 	uint32_t if_hw_tsomaxsegsize;
19380 	int32_t ip_sendflag = IP_NO_SND_TAG_RL;
19381 
19382 #ifdef INET6
19383 	struct ip6_hdr *ip6 = NULL;
19384 
19385 	if (rack->r_is_v6) {
19386 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
19387 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
19388 	} else
19389 #endif				/* INET6 */
19390 	{
19391 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
19392 		hdrlen = sizeof(struct tcpiphdr);
19393 	}
19394 	if (tp->t_port && (V_tcp_udp_tunneling_port == 0)) {
19395 		goto failed;
19396 	}
19397 	if (doing_tlp) {
19398 		/* Its a TLP add the flag, it may already be there but be sure */
19399 		rsm->r_flags |= RACK_TLP;
19400 	} else {
19401 		/* If it was a TLP it is not not on this retransmit */
19402 		rsm->r_flags &= ~RACK_TLP;
19403 	}
19404 	startseq = rsm->r_start;
19405 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
19406 	inp = rack->rc_inp;
19407 	to.to_flags = 0;
19408 	flags = tcp_outflags[tp->t_state];
19409 	if (flags & (TH_SYN|TH_RST)) {
19410 		goto failed;
19411 	}
19412 	if (rsm->r_flags & RACK_HAS_FIN) {
19413 		/* We can't send a FIN here */
19414 		goto failed;
19415 	}
19416 	if (flags & TH_FIN) {
19417 		/* We never send a FIN */
19418 		flags &= ~TH_FIN;
19419 	}
19420 	if (tp->t_flags & TF_RCVD_TSTMP) {
19421 		to.to_tsval = ms_cts + tp->ts_offset;
19422 		to.to_tsecr = tp->ts_recent;
19423 		to.to_flags = TOF_TS;
19424 	}
19425 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
19426 	/* TCP-MD5 (RFC2385). */
19427 	if (tp->t_flags & TF_SIGNATURE)
19428 		to.to_flags |= TOF_SIGNATURE;
19429 #endif
19430 	optlen = tcp_addoptions(&to, opt);
19431 	hdrlen += optlen;
19432 	udp = rack->r_ctl.fsb.udp;
19433 	if (udp)
19434 		hdrlen += sizeof(struct udphdr);
19435 	if (rack->r_ctl.rc_pace_max_segs)
19436 		max_val = rack->r_ctl.rc_pace_max_segs;
19437 	else if (rack->rc_user_set_max_segs)
19438 		max_val = rack->rc_user_set_max_segs * segsiz;
19439 	else
19440 		max_val = len;
19441 	if ((tp->t_flags & TF_TSO) &&
19442 	    V_tcp_do_tso &&
19443 	    (len > segsiz) &&
19444 	    (tp->t_port == 0))
19445 		tso = 1;
19446 #ifdef INET6
19447 	if (MHLEN < hdrlen + max_linkhdr)
19448 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
19449 	else
19450 #endif
19451 		m = m_gethdr(M_NOWAIT, MT_DATA);
19452 	if (m == NULL)
19453 		goto failed;
19454 	m->m_data += max_linkhdr;
19455 	m->m_len = hdrlen;
19456 	th = rack->r_ctl.fsb.th;
19457 	/* Establish the len to send */
19458 	if (len > max_val)
19459 		len = max_val;
19460 	if ((tso) && (len + optlen > segsiz)) {
19461 		uint32_t if_hw_tsomax;
19462 		int32_t max_len;
19463 
19464 		/* extract TSO information */
19465 		if_hw_tsomax = tp->t_tsomax;
19466 		if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
19467 		if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
19468 		/*
19469 		 * Check if we should limit by maximum payload
19470 		 * length:
19471 		 */
19472 		if (if_hw_tsomax != 0) {
19473 			/* compute maximum TSO length */
19474 			max_len = (if_hw_tsomax - hdrlen -
19475 				   max_linkhdr);
19476 			if (max_len <= 0) {
19477 				goto failed;
19478 			} else if (len > max_len) {
19479 				len = max_len;
19480 			}
19481 		}
19482 		if (len <= segsiz) {
19483 			/*
19484 			 * In case there are too many small fragments don't
19485 			 * use TSO:
19486 			 */
19487 			tso = 0;
19488 		}
19489 	} else {
19490 		tso = 0;
19491 	}
19492 	if ((tso == 0) && (len > segsiz))
19493 		len = segsiz;
19494 	(void)tcp_get_usecs(tv);
19495 	if ((len == 0) ||
19496 	    (len <= MHLEN - hdrlen - max_linkhdr)) {
19497 		goto failed;
19498 	}
19499 	th->th_seq = htonl(rsm->r_start);
19500 	th->th_ack = htonl(tp->rcv_nxt);
19501 	/*
19502 	 * The PUSH bit should only be applied
19503 	 * if the full retransmission is made. If
19504 	 * we are sending less than this is the
19505 	 * left hand edge and should not have
19506 	 * the PUSH bit.
19507 	 */
19508 	if ((rsm->r_flags & RACK_HAD_PUSH) &&
19509 	    (len == (rsm->r_end - rsm->r_start)))
19510 		flags |= TH_PUSH;
19511 	th->th_win = htons((u_short)(rack->r_ctl.fsb.recwin >> tp->rcv_scale));
19512 	if (th->th_win == 0) {
19513 		tp->t_sndzerowin++;
19514 		tp->t_flags |= TF_RXWIN0SENT;
19515 	} else
19516 		tp->t_flags &= ~TF_RXWIN0SENT;
19517 	if (rsm->r_flags & RACK_TLP) {
19518 		/*
19519 		 * TLP should not count in retran count, but
19520 		 * in its own bin
19521 		 */
19522 		counter_u64_add(rack_tlp_retran, 1);
19523 		counter_u64_add(rack_tlp_retran_bytes, len);
19524 	} else {
19525 		tp->t_sndrexmitpack++;
19526 		KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
19527 		KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
19528 	}
19529 #ifdef STATS
19530 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
19531 				 len);
19532 #endif
19533 	if (rsm->m == NULL)
19534 		goto failed;
19535 	if (rsm->m &&
19536 	    ((rsm->orig_m_len != rsm->m->m_len) ||
19537 	     (M_TRAILINGROOM(rsm->m) != rsm->orig_t_space))) {
19538 		/* Fix up the orig_m_len and possibly the mbuf offset */
19539 		rack_adjust_orig_mlen(rsm);
19540 	}
19541 	m->m_next = rack_fo_base_copym(rsm->m, rsm->soff, &len, NULL, if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, rsm->r_hw_tls);
19542 	if (len <= segsiz) {
19543 		/*
19544 		 * Must have ran out of mbufs for the copy
19545 		 * shorten it to no longer need tso. Lets
19546 		 * not put on sendalot since we are low on
19547 		 * mbufs.
19548 		 */
19549 		tso = 0;
19550 	}
19551 	if ((m->m_next == NULL) || (len <= 0)){
19552 		goto failed;
19553 	}
19554 	if (udp) {
19555 		if (rack->r_is_v6)
19556 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
19557 		else
19558 			ulen = hdrlen + len - sizeof(struct ip);
19559 		udp->uh_ulen = htons(ulen);
19560 	}
19561 	m->m_pkthdr.rcvif = (struct ifnet *)0;
19562 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
19563 	    (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))) {
19564 		int ect = tcp_ecn_output_established(tp, &flags, len, true);
19565 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
19566 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
19567 		    tp->t_flags2 &= ~TF2_ECN_SND_ECE;
19568 #ifdef INET6
19569 		if (rack->r_is_v6) {
19570 		    ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
19571 		    ip6->ip6_flow |= htonl(ect << 20);
19572 		}
19573 		else
19574 #endif
19575 		{
19576 		    ip->ip_tos &= ~IPTOS_ECN_MASK;
19577 		    ip->ip_tos |= ect;
19578 		}
19579 	}
19580 	if (rack->r_ctl.crte != NULL) {
19581 		/* See if we can send via the hw queue */
19582 		slot = rack_check_queue_level(rack, tp, tv, cts, len, segsiz);
19583 		/* If there is nothing in queue (no pacing time) we can send via the hw queue */
19584 		if (slot == 0)
19585 			ip_sendflag = 0;
19586 	}
19587 	tcp_set_flags(th, flags);
19588 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
19589 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
19590 	if (to.to_flags & TOF_SIGNATURE) {
19591 		/*
19592 		 * Calculate MD5 signature and put it into the place
19593 		 * determined before.
19594 		 * NOTE: since TCP options buffer doesn't point into
19595 		 * mbuf's data, calculate offset and use it.
19596 		 */
19597 		if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
19598 						       (u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
19599 			/*
19600 			 * Do not send segment if the calculation of MD5
19601 			 * digest has failed.
19602 			 */
19603 			goto failed;
19604 		}
19605 	}
19606 #endif
19607 #ifdef INET6
19608 	if (rack->r_is_v6) {
19609 		if (tp->t_port) {
19610 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
19611 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
19612 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
19613 			th->th_sum = htons(0);
19614 			UDPSTAT_INC(udps_opackets);
19615 		} else {
19616 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
19617 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
19618 			th->th_sum = in6_cksum_pseudo(ip6,
19619 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
19620 						      0);
19621 		}
19622 	}
19623 #endif
19624 #if defined(INET6) && defined(INET)
19625 	else
19626 #endif
19627 #ifdef INET
19628 	{
19629 		if (tp->t_port) {
19630 			m->m_pkthdr.csum_flags = CSUM_UDP;
19631 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
19632 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
19633 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
19634 			th->th_sum = htons(0);
19635 			UDPSTAT_INC(udps_opackets);
19636 		} else {
19637 			m->m_pkthdr.csum_flags = CSUM_TCP;
19638 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
19639 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
19640 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
19641 									IPPROTO_TCP + len + optlen));
19642 		}
19643 		/* IP version must be set here for ipv4/ipv6 checking later */
19644 		KASSERT(ip->ip_v == IPVERSION,
19645 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
19646 	}
19647 #endif
19648 	if (tso) {
19649 		/*
19650 		 * Here we use segsiz since we have no added options besides
19651 		 * any standard timestamp options (no DSACKs or SACKS are sent
19652 		 * via either fast-path).
19653 		 */
19654 		KASSERT(len > segsiz,
19655 			("%s: len <= tso_segsz tp:%p", __func__, tp));
19656 		m->m_pkthdr.csum_flags |= CSUM_TSO;
19657 		m->m_pkthdr.tso_segsz = segsiz;
19658 	}
19659 #ifdef INET6
19660 	if (rack->r_is_v6) {
19661 		ip6->ip6_hlim = rack->r_ctl.fsb.hoplimit;
19662 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
19663 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
19664 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
19665 		else
19666 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
19667 	}
19668 #endif
19669 #if defined(INET) && defined(INET6)
19670 	else
19671 #endif
19672 #ifdef INET
19673 	{
19674 		ip->ip_len = htons(m->m_pkthdr.len);
19675 		ip->ip_ttl = rack->r_ctl.fsb.hoplimit;
19676 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
19677 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
19678 			if (tp->t_port == 0 || len < V_tcp_minmss) {
19679 				ip->ip_off |= htons(IP_DF);
19680 			}
19681 		} else {
19682 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
19683 		}
19684 	}
19685 #endif
19686 	if (doing_tlp == 0) {
19687 		/* Set we retransmitted */
19688 		rack->rc_gp_saw_rec = 1;
19689 	} else {
19690 		/* Its a TLP set ca or ss */
19691 		if (tp->snd_cwnd > tp->snd_ssthresh) {
19692 			/* Set we sent in CA */
19693 			rack->rc_gp_saw_ca = 1;
19694 		} else {
19695 			/* Set we sent in SS */
19696 			rack->rc_gp_saw_ss = 1;
19697 		}
19698 	}
19699 	/* Time to copy in our header */
19700 	cpto = mtod(m, uint8_t *);
19701 	memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
19702 	th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
19703 	if (optlen) {
19704 		bcopy(opt, th + 1, optlen);
19705 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
19706 	} else {
19707 		th->th_off = sizeof(struct tcphdr) >> 2;
19708 	}
19709 	if (tcp_bblogging_on(rack->rc_tp)) {
19710 		union tcp_log_stackspecific log;
19711 
19712 		if (rsm->r_flags & RACK_RWND_COLLAPSED) {
19713 			rack_log_collapse(rack, rsm->r_start, rsm->r_end, 0, __LINE__, 5, rsm->r_flags, rsm);
19714 			counter_u64_add(rack_collapsed_win_rxt, 1);
19715 			counter_u64_add(rack_collapsed_win_rxt_bytes, (rsm->r_end - rsm->r_start));
19716 		}
19717 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
19718 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
19719 		if (rack->rack_no_prr)
19720 			log.u_bbr.flex1 = 0;
19721 		else
19722 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
19723 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
19724 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
19725 		log.u_bbr.flex4 = max_val;
19726 		/* Save off the early/late values */
19727 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
19728 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
19729 		log.u_bbr.bw_inuse = rack_get_bw(rack);
19730 		log.u_bbr.cur_del_rate = rack->r_ctl.gp_bw;
19731 		if (doing_tlp == 0)
19732 			log.u_bbr.flex8 = 1;
19733 		else
19734 			log.u_bbr.flex8 = 2;
19735 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
19736 		log.u_bbr.flex7 = 55;
19737 		log.u_bbr.pkts_out = tp->t_maxseg;
19738 		log.u_bbr.timeStamp = cts;
19739 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
19740 		if (rsm && (rsm->r_rtr_cnt > 0)) {
19741 			/*
19742 			 * When we have a retransmit we want to log the
19743 			 * burst at send and flight at send from before.
19744 			 */
19745 			log.u_bbr.flex5 = rsm->r_fas;
19746 			log.u_bbr.bbr_substate = rsm->r_bas;
19747 		} else {
19748 			/*
19749 			 * This is currently unlikely until we do the
19750 			 * packet pair probes but I will add it for completeness.
19751 			 */
19752 			log.u_bbr.flex5 = log.u_bbr.inflight;
19753 			log.u_bbr.bbr_substate = (uint8_t)((len + segsiz - 1)/segsiz);
19754 		}
19755 		log.u_bbr.lt_epoch = rack->r_ctl.cwnd_to_use;
19756 		log.u_bbr.delivered = 0;
19757 		log.u_bbr.rttProp = (uint64_t)rsm;
19758 		log.u_bbr.delRate = rsm->r_flags;
19759 		log.u_bbr.delRate <<= 31;
19760 		log.u_bbr.delRate |= rack->r_must_retran;
19761 		log.u_bbr.delRate <<= 1;
19762 		log.u_bbr.delRate |= 1;
19763 		log.u_bbr.pkt_epoch = __LINE__;
19764 		lgb = tcp_log_event(tp, th, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
19765 				     len, &log, false, NULL, __func__, __LINE__, tv);
19766 	} else
19767 		lgb = NULL;
19768 	if ((rack->r_ctl.crte != NULL) &&
19769 	    tcp_bblogging_on(tp)) {
19770 		rack_log_queue_level(tp, rack, len, tv, cts);
19771 	}
19772 #ifdef INET6
19773 	if (rack->r_is_v6) {
19774 		error = ip6_output(m, inp->in6p_outputopts,
19775 				   &inp->inp_route6,
19776 				   ip_sendflag, NULL, NULL, inp);
19777 	}
19778 	else
19779 #endif
19780 #ifdef INET
19781 	{
19782 		error = ip_output(m, NULL,
19783 				  &inp->inp_route,
19784 				  ip_sendflag, 0, inp);
19785 	}
19786 #endif
19787 	m = NULL;
19788 	if (lgb) {
19789 		lgb->tlb_errno = error;
19790 		lgb = NULL;
19791 	}
19792 	/* Move snd_nxt to snd_max so we don't have false retransmissions */
19793 	tp->snd_nxt = tp->snd_max;
19794 	if (error) {
19795 		goto failed;
19796 	} else if (rack->rc_hw_nobuf && (ip_sendflag != IP_NO_SND_TAG_RL)) {
19797 		rack->rc_hw_nobuf = 0;
19798 		rack->r_ctl.rc_agg_delayed = 0;
19799 		rack->r_early = 0;
19800 		rack->r_late = 0;
19801 		rack->r_ctl.rc_agg_early = 0;
19802 	}
19803 	rack_log_output(tp, &to, len, rsm->r_start, flags, error, rack_to_usec_ts(tv),
19804 			rsm, RACK_SENT_FP, rsm->m, rsm->soff, rsm->r_hw_tls, segsiz);
19805 	if (doing_tlp) {
19806 		rack->rc_tlp_in_progress = 1;
19807 		rack->r_ctl.rc_tlp_cnt_out++;
19808 	}
19809 	if (error == 0) {
19810 		counter_u64_add(rack_total_bytes, len);
19811 		tcp_account_for_send(tp, len, 1, doing_tlp, rsm->r_hw_tls);
19812 		if (doing_tlp) {
19813 			rack->rc_last_sent_tlp_past_cumack = 0;
19814 			rack->rc_last_sent_tlp_seq_valid = 1;
19815 			rack->r_ctl.last_sent_tlp_seq = rsm->r_start;
19816 			rack->r_ctl.last_sent_tlp_len = rsm->r_end - rsm->r_start;
19817 		}
19818 		if (rack->r_ctl.rc_prr_sndcnt >= len)
19819 			rack->r_ctl.rc_prr_sndcnt -= len;
19820 		else
19821 			rack->r_ctl.rc_prr_sndcnt = 0;
19822 	}
19823 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
19824 	rack->forced_ack = 0;	/* If we send something zap the FA flag */
19825 	if (IN_FASTRECOVERY(tp->t_flags) && rsm)
19826 		rack->r_ctl.retran_during_recovery += len;
19827 	{
19828 		int idx;
19829 
19830 		idx = (len / segsiz) + 3;
19831 		if (idx >= TCP_MSS_ACCT_ATIMER)
19832 			counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
19833 		else
19834 			counter_u64_add(rack_out_size[idx], 1);
19835 	}
19836 	if (tp->t_rtttime == 0) {
19837 		tp->t_rtttime = ticks;
19838 		tp->t_rtseq = startseq;
19839 		KMOD_TCPSTAT_INC(tcps_segstimed);
19840 	}
19841 	counter_u64_add(rack_fto_rsm_send, 1);
19842 	if (error && (error == ENOBUFS)) {
19843 		if (rack->r_ctl.crte != NULL) {
19844 			tcp_trace_point(rack->rc_tp, TCP_TP_HWENOBUF);
19845 			if (tcp_bblogging_on(rack->rc_tp))
19846 				rack_log_queue_level(tp, rack, len, tv, cts);
19847 		} else
19848 			tcp_trace_point(rack->rc_tp, TCP_TP_ENOBUF);
19849 		slot = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
19850 		if (rack->rc_enobuf < 0x7f)
19851 			rack->rc_enobuf++;
19852 		if (slot < (10 * HPTS_USEC_IN_MSEC))
19853 			slot = 10 * HPTS_USEC_IN_MSEC;
19854 		if (rack->r_ctl.crte != NULL) {
19855 			counter_u64_add(rack_saw_enobuf_hw, 1);
19856 			tcp_rl_log_enobuf(rack->r_ctl.crte);
19857 		}
19858 		counter_u64_add(rack_saw_enobuf, 1);
19859 	} else {
19860 		slot = rack_get_pacing_delay(rack, tp, len, NULL, segsiz, __LINE__);
19861 	}
19862 	rack_start_hpts_timer(rack, tp, cts, slot, len, 0);
19863 #ifdef TCP_ACCOUNTING
19864 	crtsc = get_cyclecount();
19865 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19866 		tp->tcp_cnt_counters[SND_OUT_DATA] += cnt_thru;
19867 	}
19868 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19869 		tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
19870 	}
19871 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19872 		tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((len + segsiz - 1) / segsiz);
19873 	}
19874 	sched_unpin();
19875 #endif
19876 	return (0);
19877 failed:
19878 	if (m)
19879 		m_free(m);
19880 	return (-1);
19881 }
19882 
19883 static void
rack_sndbuf_autoscale(struct tcp_rack * rack)19884 rack_sndbuf_autoscale(struct tcp_rack *rack)
19885 {
19886 	/*
19887 	 * Automatic sizing of send socket buffer.  Often the send buffer
19888 	 * size is not optimally adjusted to the actual network conditions
19889 	 * at hand (delay bandwidth product).  Setting the buffer size too
19890 	 * small limits throughput on links with high bandwidth and high
19891 	 * delay (eg. trans-continental/oceanic links).  Setting the
19892 	 * buffer size too big consumes too much real kernel memory,
19893 	 * especially with many connections on busy servers.
19894 	 *
19895 	 * The criteria to step up the send buffer one notch are:
19896 	 *  1. receive window of remote host is larger than send buffer
19897 	 *     (with a fudge factor of 5/4th);
19898 	 *  2. send buffer is filled to 7/8th with data (so we actually
19899 	 *     have data to make use of it);
19900 	 *  3. send buffer fill has not hit maximal automatic size;
19901 	 *  4. our send window (slow start and cogestion controlled) is
19902 	 *     larger than sent but unacknowledged data in send buffer.
19903 	 *
19904 	 * Note that the rack version moves things much faster since
19905 	 * we want to avoid hitting cache lines in the rack_fast_output()
19906 	 * path so this is called much less often and thus moves
19907 	 * the SB forward by a percentage.
19908 	 */
19909 	struct socket *so;
19910 	struct tcpcb *tp;
19911 	uint32_t sendwin, scaleup;
19912 
19913 	tp = rack->rc_tp;
19914 	so = rack->rc_inp->inp_socket;
19915 	sendwin = min(rack->r_ctl.cwnd_to_use, tp->snd_wnd);
19916 	if (V_tcp_do_autosndbuf && so->so_snd.sb_flags & SB_AUTOSIZE) {
19917 		if ((tp->snd_wnd / 4 * 5) >= so->so_snd.sb_hiwat &&
19918 		    sbused(&so->so_snd) >=
19919 		    (so->so_snd.sb_hiwat / 8 * 7) &&
19920 		    sbused(&so->so_snd) < V_tcp_autosndbuf_max &&
19921 		    sendwin >= (sbused(&so->so_snd) -
19922 		    (tp->snd_max - tp->snd_una))) {
19923 			if (rack_autosndbuf_inc)
19924 				scaleup = (rack_autosndbuf_inc * so->so_snd.sb_hiwat) / 100;
19925 			else
19926 				scaleup = V_tcp_autosndbuf_inc;
19927 			if (scaleup < V_tcp_autosndbuf_inc)
19928 				scaleup = V_tcp_autosndbuf_inc;
19929 			scaleup += so->so_snd.sb_hiwat;
19930 			if (scaleup > V_tcp_autosndbuf_max)
19931 				scaleup = V_tcp_autosndbuf_max;
19932 			if (!sbreserve_locked(so, SO_SND, scaleup, curthread))
19933 				so->so_snd.sb_flags &= ~SB_AUTOSIZE;
19934 		}
19935 	}
19936 }
19937 
19938 static int
rack_fast_output(struct tcpcb * tp,struct tcp_rack * rack,uint64_t ts_val,uint32_t cts,uint32_t ms_cts,struct timeval * tv,long tot_len,int * send_err)19939 rack_fast_output(struct tcpcb *tp, struct tcp_rack *rack, uint64_t ts_val,
19940 		 uint32_t cts, uint32_t ms_cts, struct timeval *tv, long tot_len, int *send_err)
19941 {
19942 	/*
19943 	 * Enter to do fast output. We are given that the sched_pin is
19944 	 * in place (if accounting is compiled in) and the cycle count taken
19945 	 * at entry is in place in ts_val. The idea here is that
19946 	 * we know how many more bytes needs to be sent (presumably either
19947 	 * during pacing or to fill the cwnd and that was greater than
19948 	 * the max-burst). We have how much to send and all the info we
19949 	 * need to just send.
19950 	 */
19951 #ifdef INET
19952 	struct ip *ip = NULL;
19953 #endif
19954 	struct udphdr *udp = NULL;
19955 	struct tcphdr *th = NULL;
19956 	struct mbuf *m, *s_mb;
19957 	struct inpcb *inp;
19958 	uint8_t *cpto;
19959 	struct tcp_log_buffer *lgb;
19960 #ifdef TCP_ACCOUNTING
19961 	uint64_t crtsc;
19962 #endif
19963 	struct tcpopt to;
19964 	u_char opt[TCP_MAXOLEN];
19965 	uint32_t hdrlen, optlen;
19966 #ifdef TCP_ACCOUNTING
19967 	int cnt_thru = 1;
19968 #endif
19969 	int32_t slot, segsiz, len, max_val, tso = 0, sb_offset, error, ulen = 0;
19970 	uint16_t flags;
19971 	uint32_t s_soff;
19972 	uint32_t if_hw_tsomaxsegcount = 0, startseq;
19973 	uint32_t if_hw_tsomaxsegsize;
19974 	uint32_t add_flag = RACK_SENT_FP;
19975 #ifdef INET6
19976 	struct ip6_hdr *ip6 = NULL;
19977 
19978 	if (rack->r_is_v6) {
19979 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
19980 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
19981 	} else
19982 #endif				/* INET6 */
19983 	{
19984 #ifdef INET
19985 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
19986 		hdrlen = sizeof(struct tcpiphdr);
19987 #endif
19988 	}
19989 	if (tp->t_port && (V_tcp_udp_tunneling_port == 0)) {
19990 		m = NULL;
19991 		goto failed;
19992 	}
19993 	rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
19994 	startseq = tp->snd_max;
19995 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
19996 	inp = rack->rc_inp;
19997 	len = rack->r_ctl.fsb.left_to_send;
19998 	to.to_flags = 0;
19999 	flags = rack->r_ctl.fsb.tcp_flags;
20000 	if (tp->t_flags & TF_RCVD_TSTMP) {
20001 		to.to_tsval = ms_cts + tp->ts_offset;
20002 		to.to_tsecr = tp->ts_recent;
20003 		to.to_flags = TOF_TS;
20004 	}
20005 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
20006 	/* TCP-MD5 (RFC2385). */
20007 	if (tp->t_flags & TF_SIGNATURE)
20008 		to.to_flags |= TOF_SIGNATURE;
20009 #endif
20010 	optlen = tcp_addoptions(&to, opt);
20011 	hdrlen += optlen;
20012 	udp = rack->r_ctl.fsb.udp;
20013 	if (udp)
20014 		hdrlen += sizeof(struct udphdr);
20015 	if (rack->r_ctl.rc_pace_max_segs)
20016 		max_val = rack->r_ctl.rc_pace_max_segs;
20017 	else if (rack->rc_user_set_max_segs)
20018 		max_val = rack->rc_user_set_max_segs * segsiz;
20019 	else
20020 		max_val = len;
20021 	if ((tp->t_flags & TF_TSO) &&
20022 	    V_tcp_do_tso &&
20023 	    (len > segsiz) &&
20024 	    (tp->t_port == 0))
20025 		tso = 1;
20026 again:
20027 #ifdef INET6
20028 	if (MHLEN < hdrlen + max_linkhdr)
20029 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
20030 	else
20031 #endif
20032 		m = m_gethdr(M_NOWAIT, MT_DATA);
20033 	if (m == NULL)
20034 		goto failed;
20035 	m->m_data += max_linkhdr;
20036 	m->m_len = hdrlen;
20037 	th = rack->r_ctl.fsb.th;
20038 	/* Establish the len to send */
20039 	if (len > max_val)
20040 		len = max_val;
20041 	if ((tso) && (len + optlen > segsiz)) {
20042 		uint32_t if_hw_tsomax;
20043 		int32_t max_len;
20044 
20045 		/* extract TSO information */
20046 		if_hw_tsomax = tp->t_tsomax;
20047 		if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
20048 		if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
20049 		/*
20050 		 * Check if we should limit by maximum payload
20051 		 * length:
20052 		 */
20053 		if (if_hw_tsomax != 0) {
20054 			/* compute maximum TSO length */
20055 			max_len = (if_hw_tsomax - hdrlen -
20056 				   max_linkhdr);
20057 			if (max_len <= 0) {
20058 				goto failed;
20059 			} else if (len > max_len) {
20060 				len = max_len;
20061 			}
20062 		}
20063 		if (len <= segsiz) {
20064 			/*
20065 			 * In case there are too many small fragments don't
20066 			 * use TSO:
20067 			 */
20068 			tso = 0;
20069 		}
20070 	} else {
20071 		tso = 0;
20072 	}
20073 	if ((tso == 0) && (len > segsiz))
20074 		len = segsiz;
20075 	(void)tcp_get_usecs(tv);
20076 	if ((len == 0) ||
20077 	    (len <= MHLEN - hdrlen - max_linkhdr)) {
20078 		goto failed;
20079 	}
20080 	sb_offset = tp->snd_max - tp->snd_una;
20081 	th->th_seq = htonl(tp->snd_max);
20082 	th->th_ack = htonl(tp->rcv_nxt);
20083 	th->th_win = htons((u_short)(rack->r_ctl.fsb.recwin >> tp->rcv_scale));
20084 	if (th->th_win == 0) {
20085 		tp->t_sndzerowin++;
20086 		tp->t_flags |= TF_RXWIN0SENT;
20087 	} else
20088 		tp->t_flags &= ~TF_RXWIN0SENT;
20089 	tp->snd_up = tp->snd_una;	/* drag it along, its deprecated */
20090 	KMOD_TCPSTAT_INC(tcps_sndpack);
20091 	KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
20092 #ifdef STATS
20093 	stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
20094 				 len);
20095 #endif
20096 	if (rack->r_ctl.fsb.m == NULL)
20097 		goto failed;
20098 
20099 	/* s_mb and s_soff are saved for rack_log_output */
20100 	m->m_next = rack_fo_m_copym(rack, &len, if_hw_tsomaxsegcount, if_hw_tsomaxsegsize,
20101 				    &s_mb, &s_soff);
20102 	if (len <= segsiz) {
20103 		/*
20104 		 * Must have ran out of mbufs for the copy
20105 		 * shorten it to no longer need tso. Lets
20106 		 * not put on sendalot since we are low on
20107 		 * mbufs.
20108 		 */
20109 		tso = 0;
20110 	}
20111 	if (rack->r_ctl.fsb.rfo_apply_push &&
20112 	    (len == rack->r_ctl.fsb.left_to_send)) {
20113 		tcp_set_flags(th, flags | TH_PUSH);
20114 		add_flag |= RACK_HAD_PUSH;
20115 	}
20116 	if ((m->m_next == NULL) || (len <= 0)){
20117 		goto failed;
20118 	}
20119 	if (udp) {
20120 		if (rack->r_is_v6)
20121 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
20122 		else
20123 			ulen = hdrlen + len - sizeof(struct ip);
20124 		udp->uh_ulen = htons(ulen);
20125 	}
20126 	m->m_pkthdr.rcvif = (struct ifnet *)0;
20127 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
20128 	    (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))) {
20129 		int ect = tcp_ecn_output_established(tp, &flags, len, false);
20130 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
20131 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
20132 			tp->t_flags2 &= ~TF2_ECN_SND_ECE;
20133 #ifdef INET6
20134 		if (rack->r_is_v6) {
20135 			ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
20136 			ip6->ip6_flow |= htonl(ect << 20);
20137 		}
20138 		else
20139 #endif
20140 		{
20141 #ifdef INET
20142 			ip->ip_tos &= ~IPTOS_ECN_MASK;
20143 			ip->ip_tos |= ect;
20144 #endif
20145 		}
20146 	}
20147 	tcp_set_flags(th, flags);
20148 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
20149 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
20150 	if (to.to_flags & TOF_SIGNATURE) {
20151 		/*
20152 		 * Calculate MD5 signature and put it into the place
20153 		 * determined before.
20154 		 * NOTE: since TCP options buffer doesn't point into
20155 		 * mbuf's data, calculate offset and use it.
20156 		 */
20157 		if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
20158 						       (u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
20159 			/*
20160 			 * Do not send segment if the calculation of MD5
20161 			 * digest has failed.
20162 			 */
20163 			goto failed;
20164 		}
20165 	}
20166 #endif
20167 #ifdef INET6
20168 	if (rack->r_is_v6) {
20169 		if (tp->t_port) {
20170 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
20171 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
20172 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
20173 			th->th_sum = htons(0);
20174 			UDPSTAT_INC(udps_opackets);
20175 		} else {
20176 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
20177 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
20178 			th->th_sum = in6_cksum_pseudo(ip6,
20179 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
20180 						      0);
20181 		}
20182 	}
20183 #endif
20184 #if defined(INET6) && defined(INET)
20185 	else
20186 #endif
20187 #ifdef INET
20188 	{
20189 		if (tp->t_port) {
20190 			m->m_pkthdr.csum_flags = CSUM_UDP;
20191 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
20192 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
20193 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
20194 			th->th_sum = htons(0);
20195 			UDPSTAT_INC(udps_opackets);
20196 		} else {
20197 			m->m_pkthdr.csum_flags = CSUM_TCP;
20198 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
20199 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
20200 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
20201 									IPPROTO_TCP + len + optlen));
20202 		}
20203 		/* IP version must be set here for ipv4/ipv6 checking later */
20204 		KASSERT(ip->ip_v == IPVERSION,
20205 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
20206 	}
20207 #endif
20208 	if (tso) {
20209 		/*
20210 		 * Here we use segsiz since we have no added options besides
20211 		 * any standard timestamp options (no DSACKs or SACKS are sent
20212 		 * via either fast-path).
20213 		 */
20214 		KASSERT(len > segsiz,
20215 			("%s: len <= tso_segsz tp:%p", __func__, tp));
20216 		m->m_pkthdr.csum_flags |= CSUM_TSO;
20217 		m->m_pkthdr.tso_segsz = segsiz;
20218 	}
20219 #ifdef INET6
20220 	if (rack->r_is_v6) {
20221 		ip6->ip6_hlim = rack->r_ctl.fsb.hoplimit;
20222 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
20223 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
20224 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
20225 		else
20226 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
20227 	}
20228 #endif
20229 #if defined(INET) && defined(INET6)
20230 	else
20231 #endif
20232 #ifdef INET
20233 	{
20234 		ip->ip_len = htons(m->m_pkthdr.len);
20235 		ip->ip_ttl = rack->r_ctl.fsb.hoplimit;
20236 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
20237 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
20238 			if (tp->t_port == 0 || len < V_tcp_minmss) {
20239 				ip->ip_off |= htons(IP_DF);
20240 			}
20241 		} else {
20242 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
20243 		}
20244 	}
20245 #endif
20246 	if (tp->snd_cwnd > tp->snd_ssthresh) {
20247 		/* Set we sent in CA */
20248 		rack->rc_gp_saw_ca = 1;
20249 	} else {
20250 		/* Set we sent in SS */
20251 		rack->rc_gp_saw_ss = 1;
20252 	}
20253 	/* Time to copy in our header */
20254 	cpto = mtod(m, uint8_t *);
20255 	memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
20256 	th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
20257 	if (optlen) {
20258 		bcopy(opt, th + 1, optlen);
20259 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
20260 	} else {
20261 		th->th_off = sizeof(struct tcphdr) >> 2;
20262 	}
20263 	if ((rack->r_ctl.crte != NULL) &&
20264 	    tcp_bblogging_on(tp)) {
20265 		rack_log_queue_level(tp, rack, len, tv, cts);
20266 	}
20267 	if (tcp_bblogging_on(rack->rc_tp)) {
20268 		union tcp_log_stackspecific log;
20269 
20270 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
20271 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
20272 		if (rack->rack_no_prr)
20273 			log.u_bbr.flex1 = 0;
20274 		else
20275 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
20276 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
20277 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
20278 		log.u_bbr.flex4 = max_val;
20279 		/* Save off the early/late values */
20280 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
20281 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
20282 		log.u_bbr.bw_inuse = rack_get_bw(rack);
20283 		log.u_bbr.cur_del_rate = rack->r_ctl.gp_bw;
20284 		log.u_bbr.flex8 = 0;
20285 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
20286 		log.u_bbr.flex7 = 44;
20287 		log.u_bbr.pkts_out = tp->t_maxseg;
20288 		log.u_bbr.timeStamp = cts;
20289 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
20290 		log.u_bbr.flex5 = log.u_bbr.inflight;
20291 		log.u_bbr.lt_epoch = rack->r_ctl.cwnd_to_use;
20292 		log.u_bbr.delivered = 0;
20293 		log.u_bbr.rttProp = 0;
20294 		log.u_bbr.delRate = rack->r_must_retran;
20295 		log.u_bbr.delRate <<= 1;
20296 		log.u_bbr.pkt_epoch = __LINE__;
20297 		/* For fast output no retrans so just inflight and how many mss we send */
20298 		log.u_bbr.flex5 = log.u_bbr.inflight;
20299 		log.u_bbr.bbr_substate = (uint8_t)((len + segsiz - 1)/segsiz);
20300 		lgb = tcp_log_event(tp, th, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
20301 				     len, &log, false, NULL, __func__, __LINE__, tv);
20302 	} else
20303 		lgb = NULL;
20304 #ifdef INET6
20305 	if (rack->r_is_v6) {
20306 		error = ip6_output(m, inp->in6p_outputopts,
20307 				   &inp->inp_route6,
20308 				   0, NULL, NULL, inp);
20309 	}
20310 #endif
20311 #if defined(INET) && defined(INET6)
20312 	else
20313 #endif
20314 #ifdef INET
20315 	{
20316 		error = ip_output(m, NULL,
20317 				  &inp->inp_route,
20318 				  0, 0, inp);
20319 	}
20320 #endif
20321 	if (lgb) {
20322 		lgb->tlb_errno = error;
20323 		lgb = NULL;
20324 	}
20325 	if (error) {
20326 		*send_err = error;
20327 		m = NULL;
20328 		goto failed;
20329 	} else if (rack->rc_hw_nobuf) {
20330 		rack->rc_hw_nobuf = 0;
20331 		rack->r_ctl.rc_agg_delayed = 0;
20332 		rack->r_early = 0;
20333 		rack->r_late = 0;
20334 		rack->r_ctl.rc_agg_early = 0;
20335 	}
20336 	if ((error == 0) && (rack->lt_bw_up == 0)) {
20337 		/* Unlikely */
20338 		rack->r_ctl.lt_timemark = tcp_tv_to_lusectick(tv);
20339 		rack->r_ctl.lt_seq = tp->snd_una;
20340 		rack->lt_bw_up = 1;
20341 	} else if ((error == 0) &&
20342 		   (((tp->snd_max + len) - rack->r_ctl.lt_seq) > 0x7fffffff)) {
20343 		/*
20344 		 * Need to record what we have since we are
20345 		 * approaching seq wrap.
20346 		 */
20347 		struct timeval tv;
20348 		uint64_t tmark;
20349 
20350 		rack->r_ctl.lt_bw_bytes += (tp->snd_una - rack->r_ctl.lt_seq);
20351 		rack->r_ctl.lt_seq = tp->snd_una;
20352 		tmark = tcp_get_u64_usecs(&tv);
20353 		if (tmark > rack->r_ctl.lt_timemark) {
20354 			rack->r_ctl.lt_bw_time += (tmark - rack->r_ctl.lt_timemark);
20355 			rack->r_ctl.lt_timemark = tmark;
20356 		}
20357 	}
20358 	rack_log_output(tp, &to, len, tp->snd_max, flags, error, rack_to_usec_ts(tv),
20359 			NULL, add_flag, s_mb, s_soff, rack->r_ctl.fsb.hw_tls, segsiz);
20360 	m = NULL;
20361 	if (tp->snd_una == tp->snd_max) {
20362 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
20363 		rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
20364 		tp->t_acktime = ticks;
20365 	}
20366 	counter_u64_add(rack_total_bytes, len);
20367 	tcp_account_for_send(tp, len, 0, 0, rack->r_ctl.fsb.hw_tls);
20368 
20369 	rack->forced_ack = 0;	/* If we send something zap the FA flag */
20370 	tot_len += len;
20371 	if ((tp->t_flags & TF_GPUTINPROG) == 0)
20372 		rack_start_gp_measurement(tp, rack, tp->snd_max, sb_offset);
20373 	tp->snd_max += len;
20374 	tp->snd_nxt = tp->snd_max;
20375 	if (rack->rc_new_rnd_needed) {
20376 		rack_new_round_starts(tp, rack, tp->snd_max);
20377 	}
20378 	{
20379 		int idx;
20380 
20381 		idx = (len / segsiz) + 3;
20382 		if (idx >= TCP_MSS_ACCT_ATIMER)
20383 			counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
20384 		else
20385 			counter_u64_add(rack_out_size[idx], 1);
20386 	}
20387 	if (len <= rack->r_ctl.fsb.left_to_send)
20388 		rack->r_ctl.fsb.left_to_send -= len;
20389 	else
20390 		rack->r_ctl.fsb.left_to_send = 0;
20391 	if (rack->r_ctl.fsb.left_to_send < segsiz) {
20392 		rack->r_fast_output = 0;
20393 		rack->r_ctl.fsb.left_to_send = 0;
20394 		/* At the end of fast_output scale up the sb */
20395 		SOCKBUF_LOCK(&rack->rc_inp->inp_socket->so_snd);
20396 		rack_sndbuf_autoscale(rack);
20397 		SOCKBUF_UNLOCK(&rack->rc_inp->inp_socket->so_snd);
20398 	}
20399 	if (tp->t_rtttime == 0) {
20400 		tp->t_rtttime = ticks;
20401 		tp->t_rtseq = startseq;
20402 		KMOD_TCPSTAT_INC(tcps_segstimed);
20403 	}
20404 	if ((rack->r_ctl.fsb.left_to_send >= segsiz) &&
20405 	    (max_val > len) &&
20406 	    (tso == 0)) {
20407 		max_val -= len;
20408 		len = segsiz;
20409 		th = rack->r_ctl.fsb.th;
20410 #ifdef TCP_ACCOUNTING
20411 		cnt_thru++;
20412 #endif
20413 		goto again;
20414 	}
20415 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
20416 	counter_u64_add(rack_fto_send, 1);
20417 	slot = rack_get_pacing_delay(rack, tp, tot_len, NULL, segsiz, __LINE__);
20418 	rack_start_hpts_timer(rack, tp, cts, slot, tot_len, 0);
20419 #ifdef TCP_ACCOUNTING
20420 	crtsc = get_cyclecount();
20421 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
20422 		tp->tcp_cnt_counters[SND_OUT_DATA] += cnt_thru;
20423 	}
20424 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
20425 		tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
20426 	}
20427 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
20428 		tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len + segsiz - 1) / segsiz);
20429 	}
20430 	sched_unpin();
20431 #endif
20432 	return (0);
20433 failed:
20434 	if (m)
20435 		m_free(m);
20436 	rack->r_fast_output = 0;
20437 	return (-1);
20438 }
20439 
20440 static inline void
rack_setup_fast_output(struct tcpcb * tp,struct tcp_rack * rack,struct sockbuf * sb,int len,int orig_len,int segsiz,uint32_t pace_max_seg,bool hw_tls,uint16_t flags)20441 rack_setup_fast_output(struct tcpcb *tp, struct tcp_rack *rack,
20442 		       struct sockbuf *sb,
20443 		       int len, int orig_len, int segsiz, uint32_t pace_max_seg,
20444 		       bool hw_tls,
20445 		       uint16_t flags)
20446 {
20447 	rack->r_fast_output = 1;
20448 	rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
20449 	rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
20450 	rack->r_ctl.fsb.o_t_len = M_TRAILINGROOM(rack->r_ctl.fsb.m);
20451 	rack->r_ctl.fsb.tcp_flags = flags;
20452 	rack->r_ctl.fsb.left_to_send = orig_len - len;
20453 	if (rack->r_ctl.fsb.left_to_send < pace_max_seg) {
20454 		/* Less than a full sized pace, lets not  */
20455 		rack->r_fast_output = 0;
20456 		return;
20457 	} else {
20458 		/* Round down to the nearest pace_max_seg */
20459 		rack->r_ctl.fsb.left_to_send = rounddown(rack->r_ctl.fsb.left_to_send, pace_max_seg);
20460 	}
20461 	if (hw_tls)
20462 		rack->r_ctl.fsb.hw_tls = 1;
20463 	else
20464 		rack->r_ctl.fsb.hw_tls = 0;
20465 	KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
20466 		("rack:%p left_to_send:%u sbavail:%u out:%u",
20467 		 rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
20468 		 (tp->snd_max - tp->snd_una)));
20469 	if (rack->r_ctl.fsb.left_to_send < segsiz)
20470 		rack->r_fast_output = 0;
20471 	else {
20472 		if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
20473 			rack->r_ctl.fsb.rfo_apply_push = 1;
20474 		else
20475 			rack->r_ctl.fsb.rfo_apply_push = 0;
20476 	}
20477 }
20478 
20479 static uint32_t
rack_get_hpts_pacing_min_for_bw(struct tcp_rack * rack,int32_t segsiz)20480 rack_get_hpts_pacing_min_for_bw(struct tcp_rack *rack, int32_t segsiz)
20481 {
20482 	uint64_t min_time;
20483 	uint32_t maxlen;
20484 
20485 	min_time = (uint64_t)get_hpts_min_sleep_time();
20486 	maxlen = (uint32_t)((rack->r_ctl.gp_bw * min_time) / (uint64_t)HPTS_USEC_IN_SEC);
20487 	maxlen = roundup(maxlen, segsiz);
20488 	return (maxlen);
20489 }
20490 
20491 static struct rack_sendmap *
rack_check_collapsed(struct tcp_rack * rack,uint32_t cts)20492 rack_check_collapsed(struct tcp_rack *rack, uint32_t cts)
20493 {
20494 	struct rack_sendmap *rsm = NULL;
20495 	int thresh;
20496 
20497 restart:
20498 	rsm = tqhash_find(rack->r_ctl.tqh, rack->r_ctl.last_collapse_point);
20499 	if ((rsm == NULL) || ((rsm->r_flags & RACK_RWND_COLLAPSED) == 0)) {
20500 		/* Nothing, strange turn off validity  */
20501 		rack->r_collapse_point_valid = 0;
20502 		return (NULL);
20503 	}
20504 	/* Can we send it yet? */
20505 	if (rsm->r_end > (rack->rc_tp->snd_una + rack->rc_tp->snd_wnd)) {
20506 		/*
20507 		 * Receiver window has not grown enough for
20508 		 * the segment to be put on the wire.
20509 		 */
20510 		return (NULL);
20511 	}
20512 	if (rsm->r_flags & RACK_ACKED) {
20513 		/*
20514 		 * It has been sacked, lets move to the
20515 		 * next one if possible.
20516 		 */
20517 		rack->r_ctl.last_collapse_point = rsm->r_end;
20518 		/* Are we done? */
20519 		if (SEQ_GEQ(rack->r_ctl.last_collapse_point,
20520 			    rack->r_ctl.high_collapse_point)) {
20521 			rack->r_collapse_point_valid = 0;
20522 			return (NULL);
20523 		}
20524 		goto restart;
20525 	}
20526 	/* Now has it been long enough ? */
20527 	thresh = rack_calc_thresh_rack(rack, rack_grab_rtt(rack->rc_tp, rack), cts, __LINE__, 1);
20528 	if ((cts - ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)])) > thresh) {
20529 		rack_log_collapse(rack, rsm->r_start,
20530 				  (cts - ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)])),
20531 				  thresh, __LINE__, 6, rsm->r_flags, rsm);
20532 		return (rsm);
20533 	}
20534 	/* Not enough time */
20535 	rack_log_collapse(rack, rsm->r_start,
20536 			  (cts - ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)])),
20537 			  thresh, __LINE__, 7, rsm->r_flags, rsm);
20538 	return (NULL);
20539 }
20540 
20541 static void
rack_credit_back_policer_idle_time(struct tcp_rack * rack,uint64_t idle_t,int line)20542 rack_credit_back_policer_idle_time(struct tcp_rack *rack, uint64_t idle_t, int line)
20543 {
20544 	/*
20545 	 * We were idle some time (idle_t) and so our policer bucket
20546 	 * needs to grow. It can go no higher than policer_bucket_size.
20547 	 */
20548 	uint64_t len;
20549 
20550 	len = idle_t * rack->r_ctl.policer_bw;
20551 	len /= HPTS_USEC_IN_SEC;
20552 	rack->r_ctl.current_policer_bucket += (uint32_t)len;
20553 	if (rack->r_ctl.policer_bucket_size < rack->r_ctl.current_policer_bucket) {
20554 		rack->r_ctl.current_policer_bucket = rack->r_ctl.policer_bucket_size;
20555 	}
20556 	if (rack_verbose_logging > 0)
20557 		policer_detection_log(rack, (uint32_t)len, line, (uint32_t)idle_t, 0, 7);
20558 }
20559 
20560 static inline void
rack_validate_sizes(struct tcp_rack * rack,int32_t * len,int32_t segsiz,uint32_t pace_max_seg)20561 rack_validate_sizes(struct tcp_rack *rack, int32_t *len, int32_t segsiz, uint32_t pace_max_seg)
20562 {
20563 	if ((rack->full_size_rxt == 0) &&
20564 	    (rack->shape_rxt_to_pacing_min == 0) &&
20565 	    (*len >= segsiz)) {
20566 		*len = segsiz;
20567 	} else if (rack->shape_rxt_to_pacing_min &&
20568 		 rack->gp_ready) {
20569 		/* We use pacing min as shaping len req */
20570 		uint32_t maxlen;
20571 
20572 		maxlen = rack_get_hpts_pacing_min_for_bw(rack, segsiz);
20573 		if (*len > maxlen)
20574 			*len = maxlen;
20575 	} else {
20576 		/*
20577 		 * The else is full_size_rxt is on so send it all
20578 		 * note we do need to check this for exceeding
20579 		 * our max segment size due to the fact that
20580 		 * we do sometimes merge chunks together i.e.
20581 		 * we cannot just assume that we will never have
20582 		 * a chunk greater than pace_max_seg
20583 		 */
20584 		if (*len > pace_max_seg)
20585 			*len = pace_max_seg;
20586 	}
20587 }
20588 
20589 static int
rack_output(struct tcpcb * tp)20590 rack_output(struct tcpcb *tp)
20591 {
20592 	struct socket *so;
20593 	uint32_t recwin;
20594 	uint32_t sb_offset, s_moff = 0;
20595 	int32_t len, error = 0;
20596 	uint16_t flags;
20597 	struct mbuf *m, *s_mb = NULL;
20598 	struct mbuf *mb;
20599 	uint32_t if_hw_tsomaxsegcount = 0;
20600 	uint32_t if_hw_tsomaxsegsize;
20601 	int32_t segsiz, minseg;
20602 	long tot_len_this_send = 0;
20603 #ifdef INET
20604 	struct ip *ip = NULL;
20605 #endif
20606 	struct udphdr *udp = NULL;
20607 	struct tcp_rack *rack;
20608 	struct tcphdr *th;
20609 	uint8_t pass = 0;
20610 	uint8_t mark = 0;
20611 	uint8_t check_done = 0;
20612 	uint8_t wanted_cookie = 0;
20613 	u_char opt[TCP_MAXOLEN];
20614 	unsigned ipoptlen, optlen, hdrlen, ulen=0;
20615 	uint32_t rack_seq;
20616 
20617 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
20618 	unsigned ipsec_optlen = 0;
20619 
20620 #endif
20621 	int32_t idle, sendalot;
20622 	uint32_t tot_idle;
20623 	int32_t sub_from_prr = 0;
20624 	volatile int32_t sack_rxmit;
20625 	struct rack_sendmap *rsm = NULL;
20626 	int32_t tso, mtu;
20627 	struct tcpopt to;
20628 	int32_t slot = 0;
20629 	int32_t sup_rack = 0;
20630 	uint32_t cts, ms_cts, delayed, early;
20631 	uint32_t add_flag = RACK_SENT_SP;
20632 	/* The doing_tlp flag will be set by the actual rack_timeout_tlp() */
20633 	uint8_t doing_tlp = 0;
20634 	uint32_t cwnd_to_use, pace_max_seg;
20635 	int32_t do_a_prefetch = 0;
20636 	int32_t prefetch_rsm = 0;
20637 	int32_t orig_len = 0;
20638 	struct timeval tv;
20639 	int32_t prefetch_so_done = 0;
20640 	struct tcp_log_buffer *lgb;
20641 	struct inpcb *inp = tptoinpcb(tp);
20642 	struct sockbuf *sb;
20643 	uint64_t ts_val = 0;
20644 #ifdef TCP_ACCOUNTING
20645 	uint64_t crtsc;
20646 #endif
20647 #ifdef INET6
20648 	struct ip6_hdr *ip6 = NULL;
20649 	int32_t isipv6;
20650 #endif
20651 	bool hpts_calling, hw_tls = false;
20652 
20653 	NET_EPOCH_ASSERT();
20654 	INP_WLOCK_ASSERT(inp);
20655 
20656 	/* setup and take the cache hits here */
20657 	rack = (struct tcp_rack *)tp->t_fb_ptr;
20658 #ifdef TCP_ACCOUNTING
20659 	sched_pin();
20660 	ts_val = get_cyclecount();
20661 #endif
20662 	hpts_calling = !!(tp->t_flags2 & TF2_HPTS_CALLS);
20663 	tp->t_flags2 &= ~TF2_HPTS_CALLS;
20664 #ifdef TCP_OFFLOAD
20665 	if (tp->t_flags & TF_TOE) {
20666 #ifdef TCP_ACCOUNTING
20667 		sched_unpin();
20668 #endif
20669 		return (tcp_offload_output(tp));
20670 	}
20671 #endif
20672 	if (rack->rack_deferred_inited == 0) {
20673 		/*
20674 		 * If we are the connecting socket we will
20675 		 * hit rack_init() when no sequence numbers
20676 		 * are setup. This makes it so we must defer
20677 		 * some initialization. Call that now.
20678 		 */
20679 		rack_deferred_init(tp, rack);
20680 	}
20681 	/*
20682 	 * For TFO connections in SYN_RECEIVED, only allow the initial
20683 	 * SYN|ACK and those sent by the retransmit timer.
20684 	 */
20685 	if ((tp->t_flags & TF_FASTOPEN) &&
20686 	    (tp->t_state == TCPS_SYN_RECEIVED) &&
20687 	    SEQ_GT(tp->snd_max, tp->snd_una) &&    /* initial SYN|ACK sent */
20688 	    (rack->r_ctl.rc_resend == NULL)) {         /* not a retransmit */
20689 #ifdef TCP_ACCOUNTING
20690 		sched_unpin();
20691 #endif
20692 		return (0);
20693 	}
20694 #ifdef INET6
20695 	if (rack->r_state) {
20696 		/* Use the cache line loaded if possible */
20697 		isipv6 = rack->r_is_v6;
20698 	} else {
20699 		isipv6 = (rack->rc_inp->inp_vflag & INP_IPV6) != 0;
20700 	}
20701 #endif
20702 	early = 0;
20703 	cts = tcp_get_usecs(&tv);
20704 	ms_cts = tcp_tv_to_mssectick(&tv);
20705 	if (((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) &&
20706 	    tcp_in_hpts(rack->rc_tp)) {
20707 		/*
20708 		 * We are on the hpts for some timer but not hptsi output.
20709 		 * Remove from the hpts unconditionally.
20710 		 */
20711 		rack_timer_cancel(tp, rack, cts, __LINE__);
20712 	}
20713 	/* Are we pacing and late? */
20714 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
20715 	    TSTMP_GEQ(cts, rack->r_ctl.rc_last_output_to)) {
20716 		/* We are delayed */
20717 		delayed = cts - rack->r_ctl.rc_last_output_to;
20718 	} else {
20719 		delayed = 0;
20720 	}
20721 	/* Do the timers, which may override the pacer */
20722 	if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
20723 		int retval;
20724 
20725 		retval = rack_process_timers(tp, rack, cts, hpts_calling,
20726 					     &doing_tlp);
20727 		if (retval != 0) {
20728 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_ATIMER], 1);
20729 #ifdef TCP_ACCOUNTING
20730 			sched_unpin();
20731 #endif
20732 			/*
20733 			 * If timers want tcp_drop(), then pass error out,
20734 			 * otherwise suppress it.
20735 			 */
20736 			return (retval < 0 ? retval : 0);
20737 		}
20738 	}
20739 	if (rack->rc_in_persist) {
20740 		if (tcp_in_hpts(rack->rc_tp) == 0) {
20741 			/* Timer is not running */
20742 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
20743 		}
20744 #ifdef TCP_ACCOUNTING
20745 		sched_unpin();
20746 #endif
20747 		return (0);
20748 	}
20749 	if ((rack->rc_ack_required == 1) &&
20750 	    (rack->r_timer_override == 0)){
20751 		/* A timeout occurred and no ack has arrived */
20752 		if (tcp_in_hpts(rack->rc_tp) == 0) {
20753 			/* Timer is not running */
20754 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
20755 		}
20756 #ifdef TCP_ACCOUNTING
20757 		sched_unpin();
20758 #endif
20759 		return (0);
20760 	}
20761 	if ((rack->r_timer_override) ||
20762 	    (rack->rc_ack_can_sendout_data) ||
20763 	    (delayed) ||
20764 	    (tp->t_state < TCPS_ESTABLISHED)) {
20765 		rack->rc_ack_can_sendout_data = 0;
20766 		if (tcp_in_hpts(rack->rc_tp))
20767 			tcp_hpts_remove(rack->rc_tp);
20768 	} else if (tcp_in_hpts(rack->rc_tp)) {
20769 		/*
20770 		 * On the hpts you can't pass even if ACKNOW is on, we will
20771 		 * when the hpts fires.
20772 		 */
20773 #ifdef TCP_ACCOUNTING
20774 		crtsc = get_cyclecount();
20775 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
20776 			tp->tcp_proc_time[SND_BLOCKED] += (crtsc - ts_val);
20777 		}
20778 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
20779 			tp->tcp_cnt_counters[SND_BLOCKED]++;
20780 		}
20781 		sched_unpin();
20782 #endif
20783 		counter_u64_add(rack_out_size[TCP_MSS_ACCT_INPACE], 1);
20784 		return (0);
20785 	}
20786 	/* Finish out both pacing early and late accounting */
20787 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
20788 	    TSTMP_GT(rack->r_ctl.rc_last_output_to, cts)) {
20789 		early = rack->r_ctl.rc_last_output_to - cts;
20790 	} else
20791 		early = 0;
20792 	if (delayed && (rack->rc_always_pace == 1)) {
20793 		rack->r_ctl.rc_agg_delayed += delayed;
20794 		rack->r_late = 1;
20795 	} else if (early && (rack->rc_always_pace == 1)) {
20796 		rack->r_ctl.rc_agg_early += early;
20797 		rack->r_early = 1;
20798 	} else if (rack->rc_always_pace == 0) {
20799 		/* Non-paced we are not late */
20800 		rack->r_ctl.rc_agg_delayed = rack->r_ctl.rc_agg_early = 0;
20801 		rack->r_early = rack->r_late = 0;
20802 	}
20803 	/* Now that early/late accounting is done turn off the flag */
20804 	rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
20805 	rack->r_wanted_output = 0;
20806 	rack->r_timer_override = 0;
20807 	if ((tp->t_state != rack->r_state) &&
20808 	    TCPS_HAVEESTABLISHED(tp->t_state)) {
20809 		rack_set_state(tp, rack);
20810 	}
20811 	if ((rack->r_fast_output) &&
20812 	    (doing_tlp == 0) &&
20813 	    (tp->rcv_numsacks == 0)) {
20814 		int ret;
20815 
20816 		error = 0;
20817 		ret = rack_fast_output(tp, rack, ts_val, cts, ms_cts, &tv, tot_len_this_send, &error);
20818 		if (ret >= 0)
20819 			return(ret);
20820 		else if (error) {
20821 			inp = rack->rc_inp;
20822 			so = inp->inp_socket;
20823 			sb = &so->so_snd;
20824 			goto nomore;
20825 		}
20826 	}
20827 	inp = rack->rc_inp;
20828 	/*
20829 	 * For TFO connections in SYN_SENT or SYN_RECEIVED,
20830 	 * only allow the initial SYN or SYN|ACK and those sent
20831 	 * by the retransmit timer.
20832 	 */
20833 	if ((tp->t_flags & TF_FASTOPEN) &&
20834 	    ((tp->t_state == TCPS_SYN_RECEIVED) ||
20835 	     (tp->t_state == TCPS_SYN_SENT)) &&
20836 	    SEQ_GT(tp->snd_max, tp->snd_una) && /* initial SYN or SYN|ACK sent */
20837 	    (tp->t_rxtshift == 0)) {              /* not a retransmit */
20838 		cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
20839 		so = inp->inp_socket;
20840 		sb = &so->so_snd;
20841 		goto just_return_nolock;
20842 	}
20843 	/*
20844 	 * Determine length of data that should be transmitted, and flags
20845 	 * that will be used. If there is some data or critical controls
20846 	 * (SYN, RST) to send, then transmit; otherwise, investigate
20847 	 * further.
20848 	 */
20849 	idle = (tp->t_flags & TF_LASTIDLE) || (tp->snd_max == tp->snd_una);
20850 	if (tp->t_idle_reduce) {
20851 		if (idle && (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur))
20852 			rack_cc_after_idle(rack, tp);
20853 	}
20854 	tp->t_flags &= ~TF_LASTIDLE;
20855 	if (idle) {
20856 		if (tp->t_flags & TF_MORETOCOME) {
20857 			tp->t_flags |= TF_LASTIDLE;
20858 			idle = 0;
20859 		}
20860 	}
20861 	if ((tp->snd_una == tp->snd_max) &&
20862 	    rack->r_ctl.rc_went_idle_time &&
20863 	    (cts > rack->r_ctl.rc_went_idle_time)) {
20864 		tot_idle = (cts - rack->r_ctl.rc_went_idle_time);
20865 		if (tot_idle > rack_min_probertt_hold) {
20866 			/* Count as a probe rtt */
20867 			if (rack->in_probe_rtt == 0) {
20868 				rack->r_ctl.rc_lower_rtt_us_cts = cts;
20869 				rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
20870 				rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
20871 				rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
20872 			} else {
20873 				rack_exit_probertt(rack, cts);
20874 			}
20875 		}
20876 	}
20877 	if(rack->policer_detect_on) {
20878 		/*
20879 		 * If we are doing policer detetion we at a minium
20880 		 * record the time but if possible add back to
20881 		 * the bucket based on the idle time.
20882 		 */
20883 		uint64_t idle_t, u64_cts;
20884 
20885 		segsiz = min(ctf_fixed_maxseg(tp),
20886 			     rack->r_ctl.rc_pace_min_segs);
20887 		u64_cts = tcp_tv_to_lusectick(&tv);
20888 		if ((rack->rc_policer_detected == 1) &&
20889 		    (rack->r_ctl.policer_bucket_size > segsiz) &&
20890 		    (rack->r_ctl.policer_bw > 0) &&
20891 		    (u64_cts > rack->r_ctl.last_sendtime)) {
20892 			/* We are being policed add back the time */
20893 			idle_t = u64_cts - rack->r_ctl.last_sendtime;
20894 			rack_credit_back_policer_idle_time(rack, idle_t, __LINE__);
20895 		}
20896 		rack->r_ctl.last_sendtime = u64_cts;
20897 	}
20898 	if (rack_use_fsb &&
20899 	    (rack->r_ctl.fsb.tcp_ip_hdr) &&
20900 	    (rack->r_fsb_inited == 0) &&
20901 	    (rack->r_state != TCPS_CLOSED))
20902 		rack_init_fsb_block(tp, rack, tcp_outflags[tp->t_state]);
20903 	if (rack->rc_sendvars_notset == 1) {
20904 		rack->r_ctl.idle_snd_una = tp->snd_una;
20905 		rack->rc_sendvars_notset = 0;
20906 		/*
20907 		 * Make sure any TCP timers (keep-alive) is not running.
20908 		 */
20909 		tcp_timer_stop(tp);
20910 	}
20911 	if ((rack->rack_no_prr == 1) &&
20912 	    (rack->rc_always_pace == 0)) {
20913 		/*
20914 		 * Sanity check before sending, if we have
20915 		 * no-pacing enabled and prr is turned off that
20916 		 * is a logistics error. Correct this by turnning
20917 		 * prr back on. A user *must* set some form of
20918 		 * pacing in order to turn PRR off. We do this
20919 		 * in the output path so that we can avoid socket
20920 		 * option ordering issues that would occur if we
20921 		 * tried to do it while setting rack_no_prr on.
20922 		 */
20923 		rack->rack_no_prr = 0;
20924 	}
20925 	if ((rack->pcm_enabled == 1) &&
20926 	    (rack->pcm_needed == 0) &&
20927 	    (tot_idle > 0)) {
20928 		/*
20929 		 * We have been idle some micro seconds. We need
20930 		 * to factor this in to see if a PCM is needed.
20931 		 */
20932 		uint32_t rtts_idle, rnds;
20933 
20934 		if (tp->t_srtt)
20935 			rtts_idle = tot_idle / tp->t_srtt;
20936 		else
20937 			rtts_idle = 0;
20938 		rnds = rack->r_ctl.current_round - rack->r_ctl.last_pcm_round;
20939 		rack->r_ctl.pcm_idle_rounds += rtts_idle;
20940 		if ((rnds + rack->r_ctl.pcm_idle_rounds)  >= rack_pcm_every_n_rounds) {
20941 			rack->pcm_needed = 1;
20942 			rack_log_pcm(rack, 8, rack->r_ctl.last_pcm_round, rtts_idle, rack->r_ctl.current_round );
20943 		}
20944 	}
20945 again:
20946 	sendalot = 0;
20947 	cts = tcp_get_usecs(&tv);
20948 	ms_cts = tcp_tv_to_mssectick(&tv);
20949 	tso = 0;
20950 	mtu = 0;
20951 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
20952 	minseg = segsiz;
20953 	if (rack->r_ctl.rc_pace_max_segs == 0)
20954 		pace_max_seg = rack->rc_user_set_max_segs * segsiz;
20955 	else
20956 		pace_max_seg = rack->r_ctl.rc_pace_max_segs;
20957 	if (TCPS_HAVEESTABLISHED(tp->t_state) &&
20958 	    (rack->r_ctl.pcm_max_seg == 0)) {
20959 		/*
20960 		 * We set in our first send so we know that the ctf_fixed_maxseg
20961 		 * has been fully set. If we do it in rack_init() we most likely
20962 		 * see 512 bytes so we end up at 5120, not desirable.
20963 		 */
20964 		rack->r_ctl.pcm_max_seg = rc_init_window(rack);
20965 		if (rack->r_ctl.pcm_max_seg < (ctf_fixed_maxseg(tp) * 10)) {
20966 			/*
20967 			 * Assure our initial PCM probe is at least 10 MSS.
20968 			 */
20969 			rack->r_ctl.pcm_max_seg = ctf_fixed_maxseg(tp) * 10;
20970 		}
20971 	}
20972 	if ((rack->r_ctl.pcm_max_seg != 0)  && (rack->pcm_needed == 1)) {
20973 		uint32_t rw_avail, cwa;
20974 
20975 		if (tp->snd_wnd > ctf_outstanding(tp))
20976 			rw_avail = tp->snd_wnd - ctf_outstanding(tp);
20977 		else
20978 			rw_avail = 0;
20979 		if (tp->snd_cwnd > ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked))
20980 			cwa = tp->snd_cwnd -ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
20981 		else
20982 			cwa = 0;
20983 		if ((cwa >= rack->r_ctl.pcm_max_seg) &&
20984 		    (rw_avail > rack->r_ctl.pcm_max_seg)) {
20985 			/* Raise up the max seg for this trip through */
20986 			pace_max_seg = rack->r_ctl.pcm_max_seg;
20987 			/* Disable any fast output */
20988 			rack->r_fast_output = 0;
20989 		}
20990 		if (rack_verbose_logging) {
20991 			rack_log_pcm(rack, 4,
20992 				     cwa, rack->r_ctl.pcm_max_seg, rw_avail);
20993 		}
20994 	}
20995 	sb_offset = tp->snd_max - tp->snd_una;
20996 	cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
20997 	flags = tcp_outflags[tp->t_state];
20998 	while (rack->rc_free_cnt < rack_free_cache) {
20999 		rsm = rack_alloc(rack);
21000 		if (rsm == NULL) {
21001 			if (hpts_calling)
21002 				/* Retry in a ms */
21003 				slot = (1 * HPTS_USEC_IN_MSEC);
21004 			so = inp->inp_socket;
21005 			sb = &so->so_snd;
21006 			goto just_return_nolock;
21007 		}
21008 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_free, rsm, r_tnext);
21009 		rack->rc_free_cnt++;
21010 		rsm = NULL;
21011 	}
21012 	sack_rxmit = 0;
21013 	len = 0;
21014 	rsm = NULL;
21015 	if (flags & TH_RST) {
21016 		SOCKBUF_LOCK(&inp->inp_socket->so_snd);
21017 		so = inp->inp_socket;
21018 		sb = &so->so_snd;
21019 		goto send;
21020 	}
21021 	if (rack->r_ctl.rc_resend) {
21022 		/* Retransmit timer */
21023 		rsm = rack->r_ctl.rc_resend;
21024 		rack->r_ctl.rc_resend = NULL;
21025 		len = rsm->r_end - rsm->r_start;
21026 		sack_rxmit = 1;
21027 		sendalot = 0;
21028 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
21029 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
21030 			 __func__, __LINE__,
21031 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
21032 		sb_offset = rsm->r_start - tp->snd_una;
21033 		rack_validate_sizes(rack, &len, segsiz, pace_max_seg);
21034 	} else if (rack->r_collapse_point_valid &&
21035 		   ((rsm = rack_check_collapsed(rack, cts)) != NULL)) {
21036 		/*
21037 		 * If an RSM is returned then enough time has passed
21038 		 * for us to retransmit it. Move up the collapse point,
21039 		 * since this rsm has its chance to retransmit now.
21040 		 */
21041 		tcp_trace_point(rack->rc_tp, TCP_TP_COLLAPSED_RXT);
21042 		rack->r_ctl.last_collapse_point = rsm->r_end;
21043 		/* Are we done? */
21044 		if (SEQ_GEQ(rack->r_ctl.last_collapse_point,
21045 			    rack->r_ctl.high_collapse_point))
21046 			rack->r_collapse_point_valid = 0;
21047 		sack_rxmit = 1;
21048 		/* We are not doing a TLP */
21049 		doing_tlp = 0;
21050 		len = rsm->r_end - rsm->r_start;
21051 		sb_offset = rsm->r_start - tp->snd_una;
21052 		sendalot = 0;
21053 		rack_validate_sizes(rack, &len, segsiz, pace_max_seg);
21054 	} else if ((rsm = tcp_rack_output(tp, rack, cts)) != NULL) {
21055 		/* We have a retransmit that takes precedence */
21056 		if ((!IN_FASTRECOVERY(tp->t_flags)) &&
21057 		    ((rsm->r_flags & RACK_MUST_RXT) == 0) &&
21058 		    ((tp->t_flags & TF_WASFRECOVERY) == 0)) {
21059 			/* Enter recovery if not induced by a time-out */
21060 			rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
21061 		}
21062 #ifdef INVARIANTS
21063 		if (SEQ_LT(rsm->r_start, tp->snd_una)) {
21064 			panic("Huh, tp:%p rack:%p rsm:%p start:%u < snd_una:%u\n",
21065 			      tp, rack, rsm, rsm->r_start, tp->snd_una);
21066 		}
21067 #endif
21068 		len = rsm->r_end - rsm->r_start;
21069 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
21070 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
21071 			 __func__, __LINE__,
21072 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
21073 		sb_offset = rsm->r_start - tp->snd_una;
21074 		sendalot = 0;
21075 		rack_validate_sizes(rack, &len, segsiz, pace_max_seg);
21076 		if (len > 0) {
21077 			sack_rxmit = 1;
21078 			KMOD_TCPSTAT_INC(tcps_sack_rexmits);
21079 			KMOD_TCPSTAT_ADD(tcps_sack_rexmit_bytes,
21080 					 min(len, segsiz));
21081 		}
21082 	} else if (rack->r_ctl.rc_tlpsend) {
21083 		/* Tail loss probe */
21084 		long cwin;
21085 		long tlen;
21086 
21087 		/*
21088 		 * Check if we can do a TLP with a RACK'd packet
21089 		 * this can happen if we are not doing the rack
21090 		 * cheat and we skipped to a TLP and it
21091 		 * went off.
21092 		 */
21093 		rsm = rack->r_ctl.rc_tlpsend;
21094 		/* We are doing a TLP make sure the flag is preent */
21095 		rsm->r_flags |= RACK_TLP;
21096 		rack->r_ctl.rc_tlpsend = NULL;
21097 		sack_rxmit = 1;
21098 		tlen = rsm->r_end - rsm->r_start;
21099 		if (tlen > segsiz)
21100 			tlen = segsiz;
21101 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
21102 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
21103 			 __func__, __LINE__,
21104 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
21105 		sb_offset = rsm->r_start - tp->snd_una;
21106 		cwin = min(tp->snd_wnd, tlen);
21107 		len = cwin;
21108 	}
21109 	if (rack->r_must_retran &&
21110 	    (doing_tlp == 0) &&
21111 	    (SEQ_GT(tp->snd_max, tp->snd_una)) &&
21112 	    (rsm == NULL)) {
21113 		/*
21114 		 * There are two different ways that we
21115 		 * can get into this block:
21116 		 * a) This is a non-sack connection, we had a time-out
21117 		 *    and thus r_must_retran was set and everything
21118 		 *    left outstanding as been marked for retransmit.
21119 		 * b) The MTU of the path shrank, so that everything
21120 		 *    was marked to be retransmitted with the smaller
21121 		 *    mtu and r_must_retran was set.
21122 		 *
21123 		 * This means that we expect the sendmap (outstanding)
21124 		 * to all be marked must. We can use the tmap to
21125 		 * look at them.
21126 		 *
21127 		 */
21128 		int sendwin, flight;
21129 
21130 		sendwin = min(tp->snd_wnd, tp->snd_cwnd);
21131 		flight = ctf_flight_size(tp, rack->r_ctl.rc_out_at_rto);
21132 		if (flight >= sendwin) {
21133 			/*
21134 			 * We can't send yet.
21135 			 */
21136 			so = inp->inp_socket;
21137 			sb = &so->so_snd;
21138 			goto just_return_nolock;
21139 		}
21140 		/*
21141 		 * This is the case a/b mentioned above. All
21142 		 * outstanding/not-acked should be marked.
21143 		 * We can use the tmap to find them.
21144 		 */
21145 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
21146 		if (rsm == NULL) {
21147 			/* TSNH */
21148 			rack->r_must_retran = 0;
21149 			rack->r_ctl.rc_out_at_rto = 0;
21150 			so = inp->inp_socket;
21151 			sb = &so->so_snd;
21152 			goto just_return_nolock;
21153 		}
21154 		if ((rsm->r_flags & RACK_MUST_RXT) == 0) {
21155 			/*
21156 			 * The first one does not have the flag, did we collapse
21157 			 * further up in our list?
21158 			 */
21159 			rack->r_must_retran = 0;
21160 			rack->r_ctl.rc_out_at_rto = 0;
21161 			rsm = NULL;
21162 			sack_rxmit = 0;
21163 		} else {
21164 			sack_rxmit = 1;
21165 			len = rsm->r_end - rsm->r_start;
21166 			sb_offset = rsm->r_start - tp->snd_una;
21167 			sendalot = 0;
21168 			if ((rack->full_size_rxt == 0) &&
21169 			    (rack->shape_rxt_to_pacing_min == 0) &&
21170 			    (len >= segsiz))
21171 				len = segsiz;
21172 			else if (rack->shape_rxt_to_pacing_min &&
21173 				 rack->gp_ready) {
21174 				/* We use pacing min as shaping len req */
21175 				uint32_t maxlen;
21176 
21177 				maxlen = rack_get_hpts_pacing_min_for_bw(rack, segsiz);
21178 				if (len > maxlen)
21179 					len = maxlen;
21180 			}
21181 			/*
21182 			 * Delay removing the flag RACK_MUST_RXT so
21183 			 * that the fastpath for retransmit will
21184 			 * work with this rsm.
21185 			 */
21186 		}
21187 	}
21188 	/*
21189 	 * Enforce a connection sendmap count limit if set
21190 	 * as long as we are not retransmiting.
21191 	 */
21192 	if ((rsm == NULL) &&
21193 	    (V_tcp_map_entries_limit > 0) &&
21194 	    (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
21195 		counter_u64_add(rack_to_alloc_limited, 1);
21196 		if (!rack->alloc_limit_reported) {
21197 			rack->alloc_limit_reported = 1;
21198 			counter_u64_add(rack_alloc_limited_conns, 1);
21199 		}
21200 		so = inp->inp_socket;
21201 		sb = &so->so_snd;
21202 		goto just_return_nolock;
21203 	}
21204 	if (rsm && (rsm->r_flags & RACK_HAS_FIN)) {
21205 		/* we are retransmitting the fin */
21206 		len--;
21207 		if (len) {
21208 			/*
21209 			 * When retransmitting data do *not* include the
21210 			 * FIN. This could happen from a TLP probe.
21211 			 */
21212 			flags &= ~TH_FIN;
21213 		}
21214 	}
21215 	if (rsm && rack->r_fsb_inited &&
21216 	    rack_use_rsm_rfo &&
21217 	    ((rsm->r_flags & RACK_HAS_FIN) == 0)) {
21218 		int ret;
21219 
21220 		if ((rack->rc_policer_detected == 1) &&
21221 		    (rack->r_ctl.policer_bucket_size > segsiz) &&
21222 		    (rack->r_ctl.policer_bw > 0)) {
21223 			/* Check to see if there is room */
21224 			if (rack->r_ctl.current_policer_bucket < len) {
21225 				goto skip_fast_output;
21226 			}
21227 		}
21228 		ret = rack_fast_rsm_output(tp, rack, rsm, ts_val, cts, ms_cts, &tv, len, doing_tlp);
21229 		if (ret == 0)
21230 			return (0);
21231 	}
21232 skip_fast_output:
21233 	so = inp->inp_socket;
21234 	sb = &so->so_snd;
21235 	if (do_a_prefetch == 0) {
21236 		kern_prefetch(sb, &do_a_prefetch);
21237 		do_a_prefetch = 1;
21238 	}
21239 #ifdef NETFLIX_SHARED_CWND
21240 	if ((tp->t_flags2 & TF2_TCP_SCWND_ALLOWED) &&
21241 	    rack->rack_enable_scwnd) {
21242 		/* We are doing cwnd sharing */
21243 		if (rack->gp_ready &&
21244 		    (rack->rack_attempted_scwnd == 0) &&
21245 		    (rack->r_ctl.rc_scw == NULL) &&
21246 		    tp->t_lib) {
21247 			/* The pcbid is in, lets make an attempt */
21248 			counter_u64_add(rack_try_scwnd, 1);
21249 			rack->rack_attempted_scwnd = 1;
21250 			rack->r_ctl.rc_scw = tcp_shared_cwnd_alloc(tp,
21251 								   &rack->r_ctl.rc_scw_index,
21252 								   segsiz);
21253 		}
21254 		if (rack->r_ctl.rc_scw &&
21255 		    (rack->rack_scwnd_is_idle == 1) &&
21256 		    sbavail(&so->so_snd)) {
21257 			/* we are no longer out of data */
21258 			tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
21259 			rack->rack_scwnd_is_idle = 0;
21260 		}
21261 		if (rack->r_ctl.rc_scw) {
21262 			/* First lets update and get the cwnd */
21263 			rack->r_ctl.cwnd_to_use = cwnd_to_use = tcp_shared_cwnd_update(rack->r_ctl.rc_scw,
21264 										       rack->r_ctl.rc_scw_index,
21265 										       tp->snd_cwnd, tp->snd_wnd, segsiz);
21266 		}
21267 	}
21268 #endif
21269 	/*
21270 	 * Get standard flags, and add SYN or FIN if requested by 'hidden'
21271 	 * state flags.
21272 	 */
21273 	if (tp->t_flags & TF_NEEDFIN)
21274 		flags |= TH_FIN;
21275 	if (tp->t_flags & TF_NEEDSYN)
21276 		flags |= TH_SYN;
21277 	if ((sack_rxmit == 0) && (prefetch_rsm == 0)) {
21278 		void *end_rsm;
21279 		end_rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
21280 		if (end_rsm)
21281 			kern_prefetch(end_rsm, &prefetch_rsm);
21282 		prefetch_rsm = 1;
21283 	}
21284 	SOCKBUF_LOCK(sb);
21285 	if ((sack_rxmit == 0) &&
21286 	    (TCPS_HAVEESTABLISHED(tp->t_state) ||
21287 	    (tp->t_flags & TF_FASTOPEN))) {
21288 		/*
21289 		 * We are not retransmitting (sack_rxmit is 0) so we
21290 		 * are sending new data. This is always based on snd_max.
21291 		 * Now in theory snd_max may be equal to snd_una, if so
21292 		 * then nothing is outstanding and the offset would be 0.
21293 		 */
21294 		uint32_t avail;
21295 
21296 		avail = sbavail(sb);
21297 		if (SEQ_GT(tp->snd_max, tp->snd_una) && avail)
21298 			sb_offset = tp->snd_max - tp->snd_una;
21299 		else
21300 			sb_offset = 0;
21301 		if ((IN_FASTRECOVERY(tp->t_flags) == 0) || rack->rack_no_prr) {
21302 			if (rack->r_ctl.rc_tlp_new_data) {
21303 				/* TLP is forcing out new data */
21304 				if (rack->r_ctl.rc_tlp_new_data > (uint32_t) (avail - sb_offset)) {
21305 					rack->r_ctl.rc_tlp_new_data = (uint32_t) (avail - sb_offset);
21306 				}
21307 				if ((rack->r_ctl.rc_tlp_new_data + sb_offset) > tp->snd_wnd) {
21308 					if (tp->snd_wnd > sb_offset)
21309 						len = tp->snd_wnd - sb_offset;
21310 					else
21311 						len = 0;
21312 				} else {
21313 					len = rack->r_ctl.rc_tlp_new_data;
21314 				}
21315 				rack->r_ctl.rc_tlp_new_data = 0;
21316 			}  else {
21317 				len = rack_what_can_we_send(tp, rack, cwnd_to_use, avail, sb_offset);
21318 			}
21319 			if ((rack->r_ctl.crte == NULL) &&
21320 			    IN_FASTRECOVERY(tp->t_flags) &&
21321 			    (rack->full_size_rxt == 0) &&
21322 			    (rack->shape_rxt_to_pacing_min == 0) &&
21323 			    (len > segsiz)) {
21324 				/*
21325 				 * For prr=off, we need to send only 1 MSS
21326 				 * at a time. We do this because another sack could
21327 				 * be arriving that causes us to send retransmits and
21328 				 * we don't want to be on a long pace due to a larger send
21329 				 * that keeps us from sending out the retransmit.
21330 				 */
21331 				len = segsiz;
21332 			} else if (rack->shape_rxt_to_pacing_min &&
21333 				   rack->gp_ready) {
21334 				/* We use pacing min as shaping len req */
21335 				uint32_t maxlen;
21336 
21337 				maxlen = rack_get_hpts_pacing_min_for_bw(rack, segsiz);
21338 				if (len > maxlen)
21339 					len = maxlen;
21340 			}/* The else is full_size_rxt is on so send it all */
21341 		} else {
21342 			uint32_t outstanding;
21343 			/*
21344 			 * We are inside of a Fast recovery episode, this
21345 			 * is caused by a SACK or 3 dup acks. At this point
21346 			 * we have sent all the retransmissions and we rely
21347 			 * on PRR to dictate what we will send in the form of
21348 			 * new data.
21349 			 */
21350 
21351 			outstanding = tp->snd_max - tp->snd_una;
21352 			if ((rack->r_ctl.rc_prr_sndcnt + outstanding) > tp->snd_wnd) {
21353 				if (tp->snd_wnd > outstanding) {
21354 					len = tp->snd_wnd - outstanding;
21355 					/* Check to see if we have the data */
21356 					if ((sb_offset + len) > avail) {
21357 						/* It does not all fit */
21358 						if (avail > sb_offset)
21359 							len = avail - sb_offset;
21360 						else
21361 							len = 0;
21362 					}
21363 				} else {
21364 					len = 0;
21365 				}
21366 			} else if (avail > sb_offset) {
21367 				len = avail - sb_offset;
21368 			} else {
21369 				len = 0;
21370 			}
21371 			if (len > 0) {
21372 				if (len > rack->r_ctl.rc_prr_sndcnt) {
21373 					len = rack->r_ctl.rc_prr_sndcnt;
21374 				}
21375 				if (len > 0) {
21376 					sub_from_prr = 1;
21377 				}
21378 			}
21379 			if (len > segsiz) {
21380 				/*
21381 				 * We should never send more than a MSS when
21382 				 * retransmitting or sending new data in prr
21383 				 * mode unless the override flag is on. Most
21384 				 * likely the PRR algorithm is not going to
21385 				 * let us send a lot as well :-)
21386 				 */
21387 				if (rack->r_ctl.rc_prr_sendalot == 0) {
21388 					len = segsiz;
21389 				}
21390 			} else if (len < segsiz) {
21391 				/*
21392 				 * Do we send any? The idea here is if the
21393 				 * send empty's the socket buffer we want to
21394 				 * do it. However if not then lets just wait
21395 				 * for our prr_sndcnt to get bigger.
21396 				 */
21397 				long leftinsb;
21398 
21399 				leftinsb = sbavail(sb) - sb_offset;
21400 				if (leftinsb > len) {
21401 					/* This send does not empty the sb */
21402 					len = 0;
21403 				}
21404 			}
21405 		}
21406 	} else if (!TCPS_HAVEESTABLISHED(tp->t_state)) {
21407 		/*
21408 		 * If you have not established
21409 		 * and are not doing FAST OPEN
21410 		 * no data please.
21411 		 */
21412 		if ((sack_rxmit == 0) &&
21413 		    !(tp->t_flags & TF_FASTOPEN)) {
21414 			len = 0;
21415 			sb_offset = 0;
21416 		}
21417 	}
21418 	if (prefetch_so_done == 0) {
21419 		kern_prefetch(so, &prefetch_so_done);
21420 		prefetch_so_done = 1;
21421 	}
21422 	orig_len = len;
21423 	if ((rack->rc_policer_detected == 1) &&
21424 	    (rack->r_ctl.policer_bucket_size > segsiz) &&
21425 	    (rack->r_ctl.policer_bw > 0) &&
21426 	    (len > 0)) {
21427 		/*
21428 		 * Ok we believe we have a policer watching
21429 		 * what we send, can we send len? If not can
21430 		 * we tune it down to a smaller value?
21431 		 */
21432 		uint32_t plen, buck_needs;
21433 
21434 		plen = rack_policer_check_send(rack, len, segsiz, &buck_needs);
21435 		if (plen == 0) {
21436 			/*
21437 			 * We are not allowed to send. How long
21438 			 * do we need to pace for i.e. how long
21439 			 * before len is available to send?
21440 			 */
21441 			uint64_t lentime;
21442 
21443 			lentime = buck_needs;
21444 			lentime *= HPTS_USEC_IN_SEC;
21445 			lentime /= rack->r_ctl.policer_bw;
21446 			slot = (uint32_t)lentime;
21447 			tot_len_this_send = 0;
21448 			SOCKBUF_UNLOCK(sb);
21449 			if (rack_verbose_logging > 0)
21450 				policer_detection_log(rack, len, slot, buck_needs, 0, 12);
21451 			rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
21452 			rack_log_type_just_return(rack, cts, 0, slot, hpts_calling, 0, cwnd_to_use);
21453 			goto just_return_clean;
21454 		}
21455 		if (plen < len) {
21456 			sendalot = 0;
21457 			len = plen;
21458 		}
21459 	}
21460 	/*
21461 	 * Lop off SYN bit if it has already been sent.  However, if this is
21462 	 * SYN-SENT state and if segment contains data and if we don't know
21463 	 * that foreign host supports TAO, suppress sending segment.
21464 	 */
21465 	if ((flags & TH_SYN) &&
21466 	    SEQ_GT(tp->snd_max, tp->snd_una) &&
21467 	    ((sack_rxmit == 0) &&
21468 	     (tp->t_rxtshift == 0))) {
21469 		/*
21470 		 * When sending additional segments following a TFO SYN|ACK,
21471 		 * do not include the SYN bit.
21472 		 */
21473 		if ((tp->t_flags & TF_FASTOPEN) &&
21474 		    (tp->t_state == TCPS_SYN_RECEIVED))
21475 			flags &= ~TH_SYN;
21476 	}
21477 	/*
21478 	 * Be careful not to send data and/or FIN on SYN segments. This
21479 	 * measure is needed to prevent interoperability problems with not
21480 	 * fully conformant TCP implementations.
21481 	 */
21482 	if ((flags & TH_SYN) && (tp->t_flags & TF_NOOPT)) {
21483 		len = 0;
21484 		flags &= ~TH_FIN;
21485 	}
21486 	/*
21487 	 * On TFO sockets, ensure no data is sent in the following cases:
21488 	 *
21489 	 *  - When retransmitting SYN|ACK on a passively-created socket
21490 	 *
21491 	 *  - When retransmitting SYN on an actively created socket
21492 	 *
21493 	 *  - When sending a zero-length cookie (cookie request) on an
21494 	 *    actively created socket
21495 	 *
21496 	 *  - When the socket is in the CLOSED state (RST is being sent)
21497 	 */
21498 	if ((tp->t_flags & TF_FASTOPEN) &&
21499 	    (((flags & TH_SYN) && (tp->t_rxtshift > 0)) ||
21500 	     ((tp->t_state == TCPS_SYN_SENT) &&
21501 	      (tp->t_tfo_client_cookie_len == 0)) ||
21502 	     (flags & TH_RST))) {
21503 		sack_rxmit = 0;
21504 		len = 0;
21505 	}
21506 	/* Without fast-open there should never be data sent on a SYN */
21507 	if ((flags & TH_SYN) && !(tp->t_flags & TF_FASTOPEN)) {
21508 		len = 0;
21509 	}
21510 	if ((len > segsiz) && (tcp_dsack_block_exists(tp))) {
21511 		/* We only send 1 MSS if we have a DSACK block */
21512 		add_flag |= RACK_SENT_W_DSACK;
21513 		len = segsiz;
21514 	}
21515 	if (len <= 0) {
21516 		/*
21517 		 * We have nothing to send, or the window shrank, or
21518 		 * is closed, do we need to go into persists?
21519 		 */
21520 		len = 0;
21521 		if ((tp->snd_wnd == 0) &&
21522 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
21523 		    (tp->snd_una == tp->snd_max) &&
21524 		    (sb_offset < (int)sbavail(sb))) {
21525 			rack_enter_persist(tp, rack, cts, tp->snd_una);
21526 		}
21527 	} else if ((rsm == NULL) &&
21528 		   (doing_tlp == 0) &&
21529 		   (len < pace_max_seg)) {
21530 		/*
21531 		 * We are not sending a maximum sized segment for
21532 		 * some reason. Should we not send anything (think
21533 		 * sws or persists)?
21534 		 */
21535 		if ((tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
21536 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
21537 		    (len < minseg) &&
21538 		    (len < (int)(sbavail(sb) - sb_offset))) {
21539 			/*
21540 			 * Here the rwnd is less than
21541 			 * the minimum pacing size, this is not a retransmit,
21542 			 * we are established and
21543 			 * the send is not the last in the socket buffer
21544 			 * we send nothing, and we may enter persists
21545 			 * if nothing is outstanding.
21546 			 */
21547 			len = 0;
21548 			if (tp->snd_max == tp->snd_una) {
21549 				/*
21550 				 * Nothing out we can
21551 				 * go into persists.
21552 				 */
21553 				rack_enter_persist(tp, rack, cts, tp->snd_una);
21554 			}
21555 		} else if ((cwnd_to_use >= max(minseg, (segsiz * 4))) &&
21556 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
21557 			   (len < (int)(sbavail(sb) - sb_offset)) &&
21558 			   (len < minseg)) {
21559 			/*
21560 			 * Here we are not retransmitting, and
21561 			 * the cwnd is not so small that we could
21562 			 * not send at least a min size (rxt timer
21563 			 * not having gone off), We have 2 segments or
21564 			 * more already in flight, its not the tail end
21565 			 * of the socket buffer  and the cwnd is blocking
21566 			 * us from sending out a minimum pacing segment size.
21567 			 * Lets not send anything.
21568 			 */
21569 			len = 0;
21570 		} else if (((tp->snd_wnd - ctf_outstanding(tp)) <
21571 			    min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
21572 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
21573 			   (len < (int)(sbavail(sb) - sb_offset)) &&
21574 			   (TCPS_HAVEESTABLISHED(tp->t_state))) {
21575 			/*
21576 			 * Here we have a send window but we have
21577 			 * filled it up and we can't send another pacing segment.
21578 			 * We also have in flight more than 2 segments
21579 			 * and we are not completing the sb i.e. we allow
21580 			 * the last bytes of the sb to go out even if
21581 			 * its not a full pacing segment.
21582 			 */
21583 			len = 0;
21584 		} else if ((rack->r_ctl.crte != NULL) &&
21585 			   (tp->snd_wnd >= (pace_max_seg * max(1, rack_hw_rwnd_factor))) &&
21586 			   (cwnd_to_use >= (pace_max_seg + (4 * segsiz))) &&
21587 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) >= (2 * segsiz)) &&
21588 			   (len < (int)(sbavail(sb) - sb_offset))) {
21589 			/*
21590 			 * Here we are doing hardware pacing, this is not a TLP,
21591 			 * we are not sending a pace max segment size, there is rwnd
21592 			 * room to send at least N pace_max_seg, the cwnd is greater
21593 			 * than or equal to a full pacing segments plus 4 mss and we have 2 or
21594 			 * more segments in flight and its not the tail of the socket buffer.
21595 			 *
21596 			 * We don't want to send instead we need to get more ack's in to
21597 			 * allow us to send a full pacing segment. Normally, if we are pacing
21598 			 * about the right speed, we should have finished our pacing
21599 			 * send as most of the acks have come back if we are at the
21600 			 * right rate. This is a bit fuzzy since return path delay
21601 			 * can delay the acks, which is why we want to make sure we
21602 			 * have cwnd space to have a bit more than a max pace segments in flight.
21603 			 *
21604 			 * If we have not gotten our acks back we are pacing at too high a
21605 			 * rate delaying will not hurt and will bring our GP estimate down by
21606 			 * injecting the delay. If we don't do this we will send
21607 			 * 2 MSS out in response to the acks being clocked in which
21608 			 * defeats the point of hw-pacing (i.e. to help us get
21609 			 * larger TSO's out).
21610 			 */
21611 			len = 0;
21612 		}
21613 
21614 	}
21615 	/* len will be >= 0 after this point. */
21616 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
21617 	rack_sndbuf_autoscale(rack);
21618 	/*
21619 	 * Decide if we can use TCP Segmentation Offloading (if supported by
21620 	 * hardware).
21621 	 *
21622 	 * TSO may only be used if we are in a pure bulk sending state.  The
21623 	 * presence of TCP-MD5, SACK retransmits, SACK advertizements and IP
21624 	 * options prevent using TSO.  With TSO the TCP header is the same
21625 	 * (except for the sequence number) for all generated packets.  This
21626 	 * makes it impossible to transmit any options which vary per
21627 	 * generated segment or packet.
21628 	 *
21629 	 * IPv4 handling has a clear separation of ip options and ip header
21630 	 * flags while IPv6 combines both in in6p_outputopts. ip6_optlen() does
21631 	 * the right thing below to provide length of just ip options and thus
21632 	 * checking for ipoptlen is enough to decide if ip options are present.
21633 	 */
21634 	ipoptlen = 0;
21635 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
21636 	/*
21637 	 * Pre-calculate here as we save another lookup into the darknesses
21638 	 * of IPsec that way and can actually decide if TSO is ok.
21639 	 */
21640 #ifdef INET6
21641 	if (isipv6 && IPSEC_ENABLED(ipv6))
21642 		ipsec_optlen = IPSEC_HDRSIZE(ipv6, inp);
21643 #ifdef INET
21644 	else
21645 #endif
21646 #endif				/* INET6 */
21647 #ifdef INET
21648 		if (IPSEC_ENABLED(ipv4))
21649 			ipsec_optlen = IPSEC_HDRSIZE(ipv4, inp);
21650 #endif				/* INET */
21651 #endif
21652 
21653 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
21654 	ipoptlen += ipsec_optlen;
21655 #endif
21656 	if ((tp->t_flags & TF_TSO) && V_tcp_do_tso && len > segsiz &&
21657 	    (tp->t_port == 0) &&
21658 	    ((tp->t_flags & TF_SIGNATURE) == 0) &&
21659 	    tp->rcv_numsacks == 0 && sack_rxmit == 0 &&
21660 	    ipoptlen == 0)
21661 		tso = 1;
21662 	{
21663 		uint32_t outstanding __unused;
21664 
21665 		outstanding = tp->snd_max - tp->snd_una;
21666 		if (tp->t_flags & TF_SENTFIN) {
21667 			/*
21668 			 * If we sent a fin, snd_max is 1 higher than
21669 			 * snd_una
21670 			 */
21671 			outstanding--;
21672 		}
21673 		if (sack_rxmit) {
21674 			if ((rsm->r_flags & RACK_HAS_FIN) == 0)
21675 				flags &= ~TH_FIN;
21676 		}
21677 	}
21678 	recwin = lmin(lmax(sbspace(&so->so_rcv), 0),
21679 		      (long)TCP_MAXWIN << tp->rcv_scale);
21680 
21681 	/*
21682 	 * Sender silly window avoidance.   We transmit under the following
21683 	 * conditions when len is non-zero:
21684 	 *
21685 	 * - We have a full segment (or more with TSO) - This is the last
21686 	 * buffer in a write()/send() and we are either idle or running
21687 	 * NODELAY - we've timed out (e.g. persist timer) - we have more
21688 	 * then 1/2 the maximum send window's worth of data (receiver may be
21689 	 * limited the window size) - we need to retransmit
21690 	 */
21691 	if (len) {
21692 		if (len >= segsiz) {
21693 			goto send;
21694 		}
21695 		/*
21696 		 * NOTE! on localhost connections an 'ack' from the remote
21697 		 * end may occur synchronously with the output and cause us
21698 		 * to flush a buffer queued with moretocome.  XXX
21699 		 *
21700 		 */
21701 		if (!(tp->t_flags & TF_MORETOCOME) &&	/* normal case */
21702 		    (idle || (tp->t_flags & TF_NODELAY)) &&
21703 		    ((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
21704 		    (tp->t_flags & TF_NOPUSH) == 0) {
21705 			pass = 2;
21706 			goto send;
21707 		}
21708 		if ((tp->snd_una == tp->snd_max) && len) {	/* Nothing outstanding */
21709 			pass = 22;
21710 			goto send;
21711 		}
21712 		if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0) {
21713 			pass = 4;
21714 			goto send;
21715 		}
21716 		if (sack_rxmit) {
21717 			pass = 6;
21718 			goto send;
21719 		}
21720 		if (((tp->snd_wnd - ctf_outstanding(tp)) < segsiz) &&
21721 		    (ctf_outstanding(tp) < (segsiz * 2))) {
21722 			/*
21723 			 * We have less than two MSS outstanding (delayed ack)
21724 			 * and our rwnd will not let us send a full sized
21725 			 * MSS. Lets go ahead and let this small segment
21726 			 * out because we want to try to have at least two
21727 			 * packets inflight to not be caught by delayed ack.
21728 			 */
21729 			pass = 12;
21730 			goto send;
21731 		}
21732 	}
21733 	/*
21734 	 * Sending of standalone window updates.
21735 	 *
21736 	 * Window updates are important when we close our window due to a
21737 	 * full socket buffer and are opening it again after the application
21738 	 * reads data from it.  Once the window has opened again and the
21739 	 * remote end starts to send again the ACK clock takes over and
21740 	 * provides the most current window information.
21741 	 *
21742 	 * We must avoid the silly window syndrome whereas every read from
21743 	 * the receive buffer, no matter how small, causes a window update
21744 	 * to be sent.  We also should avoid sending a flurry of window
21745 	 * updates when the socket buffer had queued a lot of data and the
21746 	 * application is doing small reads.
21747 	 *
21748 	 * Prevent a flurry of pointless window updates by only sending an
21749 	 * update when we can increase the advertized window by more than
21750 	 * 1/4th of the socket buffer capacity.  When the buffer is getting
21751 	 * full or is very small be more aggressive and send an update
21752 	 * whenever we can increase by two mss sized segments. In all other
21753 	 * situations the ACK's to new incoming data will carry further
21754 	 * window increases.
21755 	 *
21756 	 * Don't send an independent window update if a delayed ACK is
21757 	 * pending (it will get piggy-backed on it) or the remote side
21758 	 * already has done a half-close and won't send more data.  Skip
21759 	 * this if the connection is in T/TCP half-open state.
21760 	 */
21761 	if (recwin > 0 && !(tp->t_flags & TF_NEEDSYN) &&
21762 	    !(tp->t_flags & TF_DELACK) &&
21763 	    !TCPS_HAVERCVDFIN(tp->t_state)) {
21764 		/*
21765 		 * "adv" is the amount we could increase the window, taking
21766 		 * into account that we are limited by TCP_MAXWIN <<
21767 		 * tp->rcv_scale.
21768 		 */
21769 		int32_t adv;
21770 		int oldwin;
21771 
21772 		adv = recwin;
21773 		if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt)) {
21774 			oldwin = (tp->rcv_adv - tp->rcv_nxt);
21775 			if (adv > oldwin)
21776 				adv -= oldwin;
21777 			else {
21778 				/* We can't increase the window */
21779 				adv = 0;
21780 			}
21781 		} else
21782 			oldwin = 0;
21783 
21784 		/*
21785 		 * If the new window size ends up being the same as or less
21786 		 * than the old size when it is scaled, then don't force
21787 		 * a window update.
21788 		 */
21789 		if (oldwin >> tp->rcv_scale >= (adv + oldwin) >> tp->rcv_scale)
21790 			goto dontupdate;
21791 
21792 		if (adv >= (int32_t)(2 * segsiz) &&
21793 		    (adv >= (int32_t)(so->so_rcv.sb_hiwat / 4) ||
21794 		     recwin <= (int32_t)(so->so_rcv.sb_hiwat / 8) ||
21795 		     so->so_rcv.sb_hiwat <= 8 * segsiz)) {
21796 			pass = 7;
21797 			goto send;
21798 		}
21799 		if (2 * adv >= (int32_t) so->so_rcv.sb_hiwat) {
21800 			pass = 23;
21801 			goto send;
21802 		}
21803 	}
21804 dontupdate:
21805 
21806 	/*
21807 	 * Send if we owe the peer an ACK, RST, SYN, or urgent data.  ACKNOW
21808 	 * is also a catch-all for the retransmit timer timeout case.
21809 	 */
21810 	if (tp->t_flags & TF_ACKNOW) {
21811 		pass = 8;
21812 		goto send;
21813 	}
21814 	if (((flags & TH_SYN) && (tp->t_flags & TF_NEEDSYN) == 0)) {
21815 		pass = 9;
21816 		goto send;
21817 	}
21818 	/*
21819 	 * If our state indicates that FIN should be sent and we have not
21820 	 * yet done so, then we need to send.
21821 	 */
21822 	if ((flags & TH_FIN) &&
21823 	    (tp->snd_max == tp->snd_una)) {
21824 		pass = 11;
21825 		goto send;
21826 	}
21827 	/*
21828 	 * No reason to send a segment, just return.
21829 	 */
21830 just_return:
21831 	SOCKBUF_UNLOCK(sb);
21832 just_return_nolock:
21833 	{
21834 		int app_limited = CTF_JR_SENT_DATA;
21835 
21836 		if ((tp->t_flags & TF_FASTOPEN) == 0 &&
21837 		    (flags & TH_FIN) &&
21838 		    (len == 0) &&
21839 		    (sbused(sb) == (tp->snd_max - tp->snd_una)) &&
21840 		    ((tp->snd_max - tp->snd_una) <= segsiz)) {
21841 			/*
21842 			 * Ok less than or right at a MSS is
21843 			 * outstanding. The original FreeBSD stack would
21844 			 * have sent a FIN, which can speed things up for
21845 			 * a transactional application doing a MSG_WAITALL.
21846 			 * To speed things up since we do *not* send a FIN
21847 			 * if data is outstanding, we send a "challenge ack".
21848 			 * The idea behind that is instead of having to have
21849 			 * the peer wait for the delayed-ack timer to run off
21850 			 * we send an ack that makes the peer send us an ack.
21851 			 */
21852 			rack_send_ack_challange(rack);
21853 		}
21854 		if (tot_len_this_send > 0) {
21855 			rack->r_ctl.fsb.recwin = recwin;
21856 			slot = rack_get_pacing_delay(rack, tp, tot_len_this_send, NULL, segsiz, __LINE__);
21857 			if ((error == 0) &&
21858 			    (rack->rc_policer_detected == 0)  &&
21859 			    rack_use_rfo &&
21860 			    ((flags & (TH_SYN|TH_FIN)) == 0) &&
21861 			    (ipoptlen == 0) &&
21862 			    (tp->rcv_numsacks == 0) &&
21863 			    rack->r_fsb_inited &&
21864 			    TCPS_HAVEESTABLISHED(tp->t_state) &&
21865 			    ((IN_RECOVERY(tp->t_flags)) == 0) &&
21866 			    (rack->r_must_retran == 0) &&
21867 			    ((tp->t_flags & TF_NEEDFIN) == 0) &&
21868 			    (len > 0) && (orig_len > 0) &&
21869 			    (orig_len > len) &&
21870 			    ((orig_len - len) >= segsiz) &&
21871 			    ((optlen == 0) ||
21872 			     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
21873 				/* We can send at least one more MSS using our fsb */
21874 				rack_setup_fast_output(tp, rack, sb, len, orig_len,
21875 						       segsiz, pace_max_seg, hw_tls, flags);
21876 			} else
21877 				rack->r_fast_output = 0;
21878 			rack_log_fsb(rack, tp, so, flags,
21879 				     ipoptlen, orig_len, len, 0,
21880 				     1, optlen, __LINE__, 1);
21881 			/* Assure when we leave that snd_nxt will point to top */
21882 			if (SEQ_GT(tp->snd_max, tp->snd_nxt))
21883 				tp->snd_nxt = tp->snd_max;
21884 		} else {
21885 			int end_window = 0;
21886 			uint32_t seq = tp->gput_ack;
21887 
21888 			rsm = tqhash_max(rack->r_ctl.tqh);
21889 			if (rsm) {
21890 				/*
21891 				 * Mark the last sent that we just-returned (hinting
21892 				 * that delayed ack may play a role in any rtt measurement).
21893 				 */
21894 				rsm->r_just_ret = 1;
21895 			}
21896 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_JUSTRET], 1);
21897 			rack->r_ctl.rc_agg_delayed = 0;
21898 			rack->r_early = 0;
21899 			rack->r_late = 0;
21900 			rack->r_ctl.rc_agg_early = 0;
21901 			if ((ctf_outstanding(tp) +
21902 			     min(max(segsiz, (rack->r_ctl.rc_high_rwnd/2)),
21903 				 minseg)) >= tp->snd_wnd) {
21904 				/* We are limited by the rwnd */
21905 				app_limited = CTF_JR_RWND_LIMITED;
21906 				if (IN_FASTRECOVERY(tp->t_flags))
21907 					rack->r_ctl.rc_prr_sndcnt = 0;
21908 			} else if (ctf_outstanding(tp) >= sbavail(sb)) {
21909 				/* We are limited by whats available -- app limited */
21910 				app_limited = CTF_JR_APP_LIMITED;
21911 				if (IN_FASTRECOVERY(tp->t_flags))
21912 					rack->r_ctl.rc_prr_sndcnt = 0;
21913 			} else if ((idle == 0) &&
21914 				   ((tp->t_flags & TF_NODELAY) == 0) &&
21915 				   ((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
21916 				   (len < segsiz)) {
21917 				/*
21918 				 * No delay is not on and the
21919 				 * user is sending less than 1MSS. This
21920 				 * brings out SWS avoidance so we
21921 				 * don't send. Another app-limited case.
21922 				 */
21923 				app_limited = CTF_JR_APP_LIMITED;
21924 			} else if (tp->t_flags & TF_NOPUSH) {
21925 				/*
21926 				 * The user has requested no push of
21927 				 * the last segment and we are
21928 				 * at the last segment. Another app
21929 				 * limited case.
21930 				 */
21931 				app_limited = CTF_JR_APP_LIMITED;
21932 			} else if ((ctf_outstanding(tp) + minseg) > cwnd_to_use) {
21933 				/* Its the cwnd */
21934 				app_limited = CTF_JR_CWND_LIMITED;
21935 			} else if (IN_FASTRECOVERY(tp->t_flags) &&
21936 				   (rack->rack_no_prr == 0) &&
21937 				   (rack->r_ctl.rc_prr_sndcnt < segsiz)) {
21938 				app_limited = CTF_JR_PRR;
21939 			} else {
21940 				/* Now why here are we not sending? */
21941 #ifdef NOW
21942 #ifdef INVARIANTS
21943 				panic("rack:%p hit JR_ASSESSING case cwnd_to_use:%u?", rack, cwnd_to_use);
21944 #endif
21945 #endif
21946 				app_limited = CTF_JR_ASSESSING;
21947 			}
21948 			/*
21949 			 * App limited in some fashion, for our pacing GP
21950 			 * measurements we don't want any gap (even cwnd).
21951 			 * Close  down the measurement window.
21952 			 */
21953 			if (rack_cwnd_block_ends_measure &&
21954 			    ((app_limited == CTF_JR_CWND_LIMITED) ||
21955 			     (app_limited == CTF_JR_PRR))) {
21956 				/*
21957 				 * The reason we are not sending is
21958 				 * the cwnd (or prr). We have been configured
21959 				 * to end the measurement window in
21960 				 * this case.
21961 				 */
21962 				end_window = 1;
21963 			} else if (rack_rwnd_block_ends_measure &&
21964 				   (app_limited == CTF_JR_RWND_LIMITED)) {
21965 				/*
21966 				 * We are rwnd limited and have been
21967 				 * configured to end the measurement
21968 				 * window in this case.
21969 				 */
21970 				end_window = 1;
21971 			} else if (app_limited == CTF_JR_APP_LIMITED) {
21972 				/*
21973 				 * A true application limited period, we have
21974 				 * ran out of data.
21975 				 */
21976 				end_window = 1;
21977 			} else if (app_limited == CTF_JR_ASSESSING) {
21978 				/*
21979 				 * In the assessing case we hit the end of
21980 				 * the if/else and had no known reason
21981 				 * This will panic us under invariants..
21982 				 *
21983 				 * If we get this out in logs we need to
21984 				 * investagate which reason we missed.
21985 				 */
21986 				end_window = 1;
21987 			}
21988 			if (end_window) {
21989 				uint8_t log = 0;
21990 
21991 				/* Adjust the Gput measurement */
21992 				if ((tp->t_flags & TF_GPUTINPROG) &&
21993 				    SEQ_GT(tp->gput_ack, tp->snd_max)) {
21994 					tp->gput_ack = tp->snd_max;
21995 					if ((tp->gput_ack - tp->gput_seq) < (MIN_GP_WIN * segsiz)) {
21996 						/*
21997 						 * There is not enough to measure.
21998 						 */
21999 						tp->t_flags &= ~TF_GPUTINPROG;
22000 						rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
22001 									   rack->r_ctl.rc_gp_srtt /*flex1*/,
22002 									   tp->gput_seq,
22003 									   0, 0, 18, __LINE__, NULL, 0);
22004 					} else
22005 						log = 1;
22006 				}
22007 				/* Mark the last packet has app limited */
22008 				rsm = tqhash_max(rack->r_ctl.tqh);
22009 				if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
22010 					if (rack->r_ctl.rc_app_limited_cnt == 0)
22011 						rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
22012 					else {
22013 						/*
22014 						 * Go out to the end app limited and mark
22015 						 * this new one as next and move the end_appl up
22016 						 * to this guy.
22017 						 */
22018 						if (rack->r_ctl.rc_end_appl)
22019 							rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
22020 						rack->r_ctl.rc_end_appl = rsm;
22021 					}
22022 					rsm->r_flags |= RACK_APP_LIMITED;
22023 					rack->r_ctl.rc_app_limited_cnt++;
22024 				}
22025 				if (log)
22026 					rack_log_pacing_delay_calc(rack,
22027 								   rack->r_ctl.rc_app_limited_cnt, seq,
22028 								   tp->gput_ack, 0, 0, 4, __LINE__, NULL, 0);
22029 			}
22030 		}
22031 		/* Check if we need to go into persists or not */
22032 		if ((tp->snd_max == tp->snd_una) &&
22033 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
22034 		    sbavail(sb) &&
22035 		    (sbavail(sb) > tp->snd_wnd) &&
22036 		    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg))) {
22037 			/* Yes lets make sure to move to persist before timer-start */
22038 			rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime, tp->snd_una);
22039 		}
22040 		rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, sup_rack);
22041 		rack_log_type_just_return(rack, cts, tot_len_this_send, slot, hpts_calling, app_limited, cwnd_to_use);
22042 	}
22043 just_return_clean:
22044 #ifdef NETFLIX_SHARED_CWND
22045 	if ((sbavail(sb) == 0) &&
22046 	    rack->r_ctl.rc_scw) {
22047 		tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
22048 		rack->rack_scwnd_is_idle = 1;
22049 	}
22050 #endif
22051 #ifdef TCP_ACCOUNTING
22052 	if (tot_len_this_send > 0) {
22053 		crtsc = get_cyclecount();
22054 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22055 			tp->tcp_cnt_counters[SND_OUT_DATA]++;
22056 		}
22057 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22058 			tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
22059 		}
22060 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22061 			tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len_this_send + segsiz - 1) / segsiz);
22062 		}
22063 	} else {
22064 		crtsc = get_cyclecount();
22065 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22066 			tp->tcp_cnt_counters[SND_LIMITED]++;
22067 		}
22068 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22069 			tp->tcp_proc_time[SND_LIMITED] += (crtsc - ts_val);
22070 		}
22071 	}
22072 	sched_unpin();
22073 #endif
22074 	return (0);
22075 
22076 send:
22077 	if ((rack->r_ctl.crte != NULL) &&
22078 	    (rsm == NULL) &&
22079 	    ((rack->rc_hw_nobuf == 1) ||
22080 	     (rack_hw_check_queue && (check_done == 0)))) {
22081 		/*
22082 		 * We only want to do this once with the hw_check_queue,
22083 		 * for the enobuf case we would only do it once if
22084 		 * we come around to again, the flag will be clear.
22085 		 */
22086 		check_done = 1;
22087 		slot = rack_check_queue_level(rack, tp, &tv, cts, len, segsiz);
22088 		if (slot) {
22089 			rack->r_ctl.rc_agg_delayed = 0;
22090 			rack->r_ctl.rc_agg_early = 0;
22091 			rack->r_early = 0;
22092 			rack->r_late = 0;
22093 			SOCKBUF_UNLOCK(&so->so_snd);
22094 			goto skip_all_send;
22095 		}
22096 	}
22097 	if (rsm || sack_rxmit)
22098 		counter_u64_add(rack_nfto_resend, 1);
22099 	else
22100 		counter_u64_add(rack_non_fto_send, 1);
22101 	if ((flags & TH_FIN) &&
22102 	    sbavail(sb)) {
22103 		/*
22104 		 * We do not transmit a FIN
22105 		 * with data outstanding. We
22106 		 * need to make it so all data
22107 		 * is acked first.
22108 		 */
22109 		flags &= ~TH_FIN;
22110 		if (TCPS_HAVEESTABLISHED(tp->t_state) &&
22111 		    (sbused(sb) == (tp->snd_max - tp->snd_una)) &&
22112 		    ((tp->snd_max - tp->snd_una) <= segsiz)) {
22113 			/*
22114 			 * Ok less than or right at a MSS is
22115 			 * outstanding. The original FreeBSD stack would
22116 			 * have sent a FIN, which can speed things up for
22117 			 * a transactional application doing a MSG_WAITALL.
22118 			 * To speed things up since we do *not* send a FIN
22119 			 * if data is outstanding, we send a "challenge ack".
22120 			 * The idea behind that is instead of having to have
22121 			 * the peer wait for the delayed-ack timer to run off
22122 			 * we send an ack that makes the peer send us an ack.
22123 			 */
22124 			rack_send_ack_challange(rack);
22125 		}
22126 	}
22127 	/* Enforce stack imposed max seg size if we have one */
22128 	if (pace_max_seg &&
22129 	    (len > pace_max_seg)) {
22130 		mark = 1;
22131 		len = pace_max_seg;
22132 	}
22133 	if ((rsm == NULL) &&
22134 	    (rack->pcm_in_progress == 0) &&
22135 	    (rack->r_ctl.pcm_max_seg > 0) &&
22136 	    (len >= rack->r_ctl.pcm_max_seg)) {
22137 		/* It is large enough for a measurement */
22138 		add_flag |= RACK_IS_PCM;
22139 		rack_log_pcm(rack, 5, len, rack->r_ctl.pcm_max_seg,  add_flag);
22140 	} else if (rack_verbose_logging) {
22141 		rack_log_pcm(rack, 6, len, rack->r_ctl.pcm_max_seg,  add_flag);
22142 	}
22143 
22144 	SOCKBUF_LOCK_ASSERT(sb);
22145 	if (len > 0) {
22146 		if (len >= segsiz)
22147 			tp->t_flags2 |= TF2_PLPMTU_MAXSEGSNT;
22148 		else
22149 			tp->t_flags2 &= ~TF2_PLPMTU_MAXSEGSNT;
22150 	}
22151 	/*
22152 	 * Before ESTABLISHED, force sending of initial options unless TCP
22153 	 * set not to do any options. NOTE: we assume that the IP/TCP header
22154 	 * plus TCP options always fit in a single mbuf, leaving room for a
22155 	 * maximum link header, i.e. max_linkhdr + sizeof (struct tcpiphdr)
22156 	 * + optlen <= MCLBYTES
22157 	 */
22158 	optlen = 0;
22159 #ifdef INET6
22160 	if (isipv6)
22161 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
22162 	else
22163 #endif
22164 		hdrlen = sizeof(struct tcpiphdr);
22165 
22166 	/*
22167 	 * Ok what seq are we sending from. If we have
22168 	 * no rsm to use, then we look at various bits,
22169 	 * if we are putting out a SYN it will be ISS.
22170 	 * If we are retransmitting a FIN it will
22171 	 * be snd_max-1 else its snd_max.
22172 	 */
22173 	if (rsm == NULL) {
22174 		if (flags & TH_SYN)
22175 			rack_seq = tp->iss;
22176 		else if ((flags & TH_FIN) &&
22177 			 (tp->t_flags & TF_SENTFIN))
22178 			rack_seq = tp->snd_max - 1;
22179 		else
22180 			rack_seq = tp->snd_max;
22181 	} else {
22182 		rack_seq = rsm->r_start;
22183 	}
22184 	/*
22185 	 * Compute options for segment. We only have to care about SYN and
22186 	 * established connection segments.  Options for SYN-ACK segments
22187 	 * are handled in TCP syncache.
22188 	 */
22189 	to.to_flags = 0;
22190 	if ((tp->t_flags & TF_NOOPT) == 0) {
22191 		/* Maximum segment size. */
22192 		if (flags & TH_SYN) {
22193 			to.to_mss = tcp_mssopt(&inp->inp_inc);
22194 			if (tp->t_port)
22195 				to.to_mss -= V_tcp_udp_tunneling_overhead;
22196 			to.to_flags |= TOF_MSS;
22197 
22198 			/*
22199 			 * On SYN or SYN|ACK transmits on TFO connections,
22200 			 * only include the TFO option if it is not a
22201 			 * retransmit, as the presence of the TFO option may
22202 			 * have caused the original SYN or SYN|ACK to have
22203 			 * been dropped by a middlebox.
22204 			 */
22205 			if ((tp->t_flags & TF_FASTOPEN) &&
22206 			    (tp->t_rxtshift == 0)) {
22207 				if (tp->t_state == TCPS_SYN_RECEIVED) {
22208 					to.to_tfo_len = TCP_FASTOPEN_COOKIE_LEN;
22209 					to.to_tfo_cookie =
22210 						(u_int8_t *)&tp->t_tfo_cookie.server;
22211 					to.to_flags |= TOF_FASTOPEN;
22212 					wanted_cookie = 1;
22213 				} else if (tp->t_state == TCPS_SYN_SENT) {
22214 					to.to_tfo_len =
22215 						tp->t_tfo_client_cookie_len;
22216 					to.to_tfo_cookie =
22217 						tp->t_tfo_cookie.client;
22218 					to.to_flags |= TOF_FASTOPEN;
22219 					wanted_cookie = 1;
22220 					/*
22221 					 * If we wind up having more data to
22222 					 * send with the SYN than can fit in
22223 					 * one segment, don't send any more
22224 					 * until the SYN|ACK comes back from
22225 					 * the other end.
22226 					 */
22227 					sendalot = 0;
22228 				}
22229 			}
22230 		}
22231 		/* Window scaling. */
22232 		if ((flags & TH_SYN) && (tp->t_flags & TF_REQ_SCALE)) {
22233 			to.to_wscale = tp->request_r_scale;
22234 			to.to_flags |= TOF_SCALE;
22235 		}
22236 		/* Timestamps. */
22237 		if ((tp->t_flags & TF_RCVD_TSTMP) ||
22238 		    ((flags & TH_SYN) && (tp->t_flags & TF_REQ_TSTMP))) {
22239 			uint32_t ts_to_use;
22240 
22241 			if ((rack->r_rcvpath_rtt_up == 1) &&
22242 			    (ms_cts == rack->r_ctl.last_rcv_tstmp_for_rtt)) {
22243 				/*
22244 				 * When we are doing a rcv_rtt probe all
22245 				 * other timestamps use the next msec. This
22246 				 * is safe since our previous ack is in the
22247 				 * air and we will just have a few more
22248 				 * on the next ms. This assures that only
22249 				 * the one ack has the ms_cts that was on
22250 				 * our ack-probe.
22251 				 */
22252 				ts_to_use = ms_cts + 1;
22253 			} else {
22254 				ts_to_use = ms_cts;
22255 			}
22256 			to.to_tsval = ts_to_use + tp->ts_offset;
22257 			to.to_tsecr = tp->ts_recent;
22258 			to.to_flags |= TOF_TS;
22259 			if ((len == 0) &&
22260 			    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
22261 			    ((ms_cts - rack->r_ctl.last_rcv_tstmp_for_rtt) > RCV_PATH_RTT_MS) &&
22262 			    (tp->snd_una == tp->snd_max) &&
22263 			    (flags & TH_ACK) &&
22264 			    (sbavail(sb) == 0) &&
22265 			    (rack->r_ctl.current_round != 0) &&
22266 			    ((flags & (TH_SYN|TH_FIN)) == 0) &&
22267 			    (rack->r_rcvpath_rtt_up == 0)) {
22268 				rack->r_ctl.last_rcv_tstmp_for_rtt = ms_cts;
22269 				rack->r_ctl.last_time_of_arm_rcv = cts;
22270 				rack->r_rcvpath_rtt_up = 1;
22271 				/* Subtract 1 from seq to force a response */
22272 				rack_seq--;
22273 			}
22274 		}
22275 		/* Set receive buffer autosizing timestamp. */
22276 		if (tp->rfbuf_ts == 0 &&
22277 		    (so->so_rcv.sb_flags & SB_AUTOSIZE)) {
22278 			tp->rfbuf_ts = ms_cts;
22279 		}
22280 		/* Selective ACK's. */
22281 		if (tp->t_flags & TF_SACK_PERMIT) {
22282 			if (flags & TH_SYN)
22283 				to.to_flags |= TOF_SACKPERM;
22284 			else if (TCPS_HAVEESTABLISHED(tp->t_state) &&
22285 				 tp->rcv_numsacks > 0) {
22286 				to.to_flags |= TOF_SACK;
22287 				to.to_nsacks = tp->rcv_numsacks;
22288 				to.to_sacks = (u_char *)tp->sackblks;
22289 			}
22290 		}
22291 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
22292 		/* TCP-MD5 (RFC2385). */
22293 		if (tp->t_flags & TF_SIGNATURE)
22294 			to.to_flags |= TOF_SIGNATURE;
22295 #endif
22296 
22297 		/* Processing the options. */
22298 		hdrlen += optlen = tcp_addoptions(&to, opt);
22299 		/*
22300 		 * If we wanted a TFO option to be added, but it was unable
22301 		 * to fit, ensure no data is sent.
22302 		 */
22303 		if ((tp->t_flags & TF_FASTOPEN) && wanted_cookie &&
22304 		    !(to.to_flags & TOF_FASTOPEN))
22305 			len = 0;
22306 	}
22307 	if (tp->t_port) {
22308 		if (V_tcp_udp_tunneling_port == 0) {
22309 			/* The port was removed?? */
22310 			SOCKBUF_UNLOCK(&so->so_snd);
22311 #ifdef TCP_ACCOUNTING
22312 			crtsc = get_cyclecount();
22313 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22314 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
22315 			}
22316 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22317 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
22318 			}
22319 			sched_unpin();
22320 #endif
22321 			return (EHOSTUNREACH);
22322 		}
22323 		hdrlen += sizeof(struct udphdr);
22324 	}
22325 #ifdef INET6
22326 	if (isipv6)
22327 		ipoptlen = ip6_optlen(inp);
22328 	else
22329 #endif
22330 		if (inp->inp_options)
22331 			ipoptlen = inp->inp_options->m_len -
22332 				offsetof(struct ipoption, ipopt_list);
22333 		else
22334 			ipoptlen = 0;
22335 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
22336 	ipoptlen += ipsec_optlen;
22337 #endif
22338 
22339 	/*
22340 	 * Adjust data length if insertion of options will bump the packet
22341 	 * length beyond the t_maxseg length. Clear the FIN bit because we
22342 	 * cut off the tail of the segment.
22343 	 */
22344 	if (len + optlen + ipoptlen > tp->t_maxseg) {
22345 		if (tso) {
22346 			uint32_t if_hw_tsomax;
22347 			uint32_t moff;
22348 			int32_t max_len;
22349 
22350 			/* extract TSO information */
22351 			if_hw_tsomax = tp->t_tsomax;
22352 			if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
22353 			if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
22354 			KASSERT(ipoptlen == 0,
22355 				("%s: TSO can't do IP options", __func__));
22356 
22357 			/*
22358 			 * Check if we should limit by maximum payload
22359 			 * length:
22360 			 */
22361 			if (if_hw_tsomax != 0) {
22362 				/* compute maximum TSO length */
22363 				max_len = (if_hw_tsomax - hdrlen -
22364 					   max_linkhdr);
22365 				if (max_len <= 0) {
22366 					len = 0;
22367 				} else if (len > max_len) {
22368 					sendalot = 1;
22369 					len = max_len;
22370 					mark = 2;
22371 				}
22372 			}
22373 			/*
22374 			 * Prevent the last segment from being fractional
22375 			 * unless the send sockbuf can be emptied:
22376 			 */
22377 			max_len = (tp->t_maxseg - optlen);
22378 			if ((sb_offset + len) < sbavail(sb)) {
22379 				moff = len % (u_int)max_len;
22380 				if (moff != 0) {
22381 					mark = 3;
22382 					len -= moff;
22383 				}
22384 			}
22385 			/*
22386 			 * In case there are too many small fragments don't
22387 			 * use TSO:
22388 			 */
22389 			if (len <= max_len) {
22390 				mark = 4;
22391 				tso = 0;
22392 			}
22393 			/*
22394 			 * Send the FIN in a separate segment after the bulk
22395 			 * sending is done. We don't trust the TSO
22396 			 * implementations to clear the FIN flag on all but
22397 			 * the last segment.
22398 			 */
22399 			if (tp->t_flags & TF_NEEDFIN) {
22400 				sendalot = 4;
22401 			}
22402 		} else {
22403 			mark = 5;
22404 			if (optlen + ipoptlen >= tp->t_maxseg) {
22405 				/*
22406 				 * Since we don't have enough space to put
22407 				 * the IP header chain and the TCP header in
22408 				 * one packet as required by RFC 7112, don't
22409 				 * send it. Also ensure that at least one
22410 				 * byte of the payload can be put into the
22411 				 * TCP segment.
22412 				 */
22413 				SOCKBUF_UNLOCK(&so->so_snd);
22414 				error = EMSGSIZE;
22415 				sack_rxmit = 0;
22416 				goto out;
22417 			}
22418 			len = tp->t_maxseg - optlen - ipoptlen;
22419 			sendalot = 5;
22420 		}
22421 	} else {
22422 		tso = 0;
22423 		mark = 6;
22424 	}
22425 	KASSERT(len + hdrlen + ipoptlen <= IP_MAXPACKET,
22426 		("%s: len > IP_MAXPACKET", __func__));
22427 #ifdef DIAGNOSTIC
22428 #ifdef INET6
22429 	if (max_linkhdr + hdrlen > MCLBYTES)
22430 #else
22431 		if (max_linkhdr + hdrlen > MHLEN)
22432 #endif
22433 			panic("tcphdr too big");
22434 #endif
22435 
22436 	/*
22437 	 * This KASSERT is here to catch edge cases at a well defined place.
22438 	 * Before, those had triggered (random) panic conditions further
22439 	 * down.
22440 	 */
22441 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
22442 	if ((len == 0) &&
22443 	    (flags & TH_FIN) &&
22444 	    (sbused(sb))) {
22445 		/*
22446 		 * We have outstanding data, don't send a fin by itself!.
22447 		 *
22448 		 * Check to see if we need to send a challenge ack.
22449 		 */
22450 		if ((sbused(sb) == (tp->snd_max - tp->snd_una)) &&
22451 		    ((tp->snd_max - tp->snd_una) <= segsiz)) {
22452 			/*
22453 			 * Ok less than or right at a MSS is
22454 			 * outstanding. The original FreeBSD stack would
22455 			 * have sent a FIN, which can speed things up for
22456 			 * a transactional application doing a MSG_WAITALL.
22457 			 * To speed things up since we do *not* send a FIN
22458 			 * if data is outstanding, we send a "challenge ack".
22459 			 * The idea behind that is instead of having to have
22460 			 * the peer wait for the delayed-ack timer to run off
22461 			 * we send an ack that makes the peer send us an ack.
22462 			 */
22463 			rack_send_ack_challange(rack);
22464 		}
22465 		goto just_return;
22466 	}
22467 	/*
22468 	 * Grab a header mbuf, attaching a copy of data to be transmitted,
22469 	 * and initialize the header from the template for sends on this
22470 	 * connection.
22471 	 */
22472 	hw_tls = tp->t_nic_ktls_xmit != 0;
22473 	if (len) {
22474 		uint32_t max_val;
22475 		uint32_t moff;
22476 
22477 		if (pace_max_seg)
22478 			max_val = pace_max_seg;
22479 		else
22480 			max_val = len;
22481 		/*
22482 		 * We allow a limit on sending with hptsi.
22483 		 */
22484 		if (len > max_val) {
22485 			mark = 7;
22486 			len = max_val;
22487 		}
22488 #ifdef INET6
22489 		if (MHLEN < hdrlen + max_linkhdr)
22490 			m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
22491 		else
22492 #endif
22493 			m = m_gethdr(M_NOWAIT, MT_DATA);
22494 
22495 		if (m == NULL) {
22496 			SOCKBUF_UNLOCK(sb);
22497 			error = ENOBUFS;
22498 			sack_rxmit = 0;
22499 			goto out;
22500 		}
22501 		m->m_data += max_linkhdr;
22502 		m->m_len = hdrlen;
22503 
22504 		/*
22505 		 * Start the m_copy functions from the closest mbuf to the
22506 		 * sb_offset in the socket buffer chain.
22507 		 */
22508 		mb = sbsndptr_noadv(sb, sb_offset, &moff);
22509 		s_mb = mb;
22510 		s_moff = moff;
22511 		if (len <= MHLEN - hdrlen - max_linkhdr && !hw_tls) {
22512 			m_copydata(mb, moff, (int)len,
22513 				   mtod(m, caddr_t)+hdrlen);
22514 			/*
22515 			 * If we are not retransmitting advance the
22516 			 * sndptr to help remember the next place in
22517 			 * the sb.
22518 			 */
22519 			if (rsm == NULL)
22520 				sbsndptr_adv(sb, mb, len);
22521 			m->m_len += len;
22522 		} else {
22523 			struct sockbuf *msb;
22524 
22525 			/*
22526 			 * If we are not retransmitting pass in msb so
22527 			 * the socket buffer can be advanced. Otherwise
22528 			 * set it to NULL if its a retransmission since
22529 			 * we don't want to change the sb remembered
22530 			 * location.
22531 			 */
22532 			if (rsm == NULL)
22533 				msb = sb;
22534 			else
22535 				msb = NULL;
22536 			m->m_next = tcp_m_copym(
22537 				mb, moff, &len,
22538 				if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, msb,
22539 				((rsm == NULL) ? hw_tls : 0)
22540 #ifdef NETFLIX_COPY_ARGS
22541 				, &s_mb, &s_moff
22542 #endif
22543 				);
22544 			if (len <= (tp->t_maxseg - optlen)) {
22545 				/*
22546 				 * Must have ran out of mbufs for the copy
22547 				 * shorten it to no longer need tso. Lets
22548 				 * not put on sendalot since we are low on
22549 				 * mbufs.
22550 				 */
22551 				tso = 0;
22552 			}
22553 			if (m->m_next == NULL) {
22554 				SOCKBUF_UNLOCK(sb);
22555 				(void)m_free(m);
22556 				error = ENOBUFS;
22557 				sack_rxmit = 0;
22558 				goto out;
22559 			}
22560 		}
22561 		if (sack_rxmit) {
22562 			if (rsm && (rsm->r_flags & RACK_TLP)) {
22563 				/*
22564 				 * TLP should not count in retran count, but
22565 				 * in its own bin
22566 				 */
22567 				counter_u64_add(rack_tlp_retran, 1);
22568 				counter_u64_add(rack_tlp_retran_bytes, len);
22569 			} else {
22570 				tp->t_sndrexmitpack++;
22571 				KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
22572 				KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
22573 			}
22574 #ifdef STATS
22575 			stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
22576 						 len);
22577 #endif
22578 		} else {
22579 			KMOD_TCPSTAT_INC(tcps_sndpack);
22580 			KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
22581 #ifdef STATS
22582 			stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
22583 						 len);
22584 #endif
22585 		}
22586 		/*
22587 		 * If we're sending everything we've got, set PUSH. (This
22588 		 * will keep happy those implementations which only give
22589 		 * data to the user when a buffer fills or a PUSH comes in.)
22590 		 */
22591 		if (sb_offset + len == sbused(sb) &&
22592 		    sbused(sb) &&
22593 		    !(flags & TH_SYN)) {
22594 			flags |= TH_PUSH;
22595 			add_flag |= RACK_HAD_PUSH;
22596 		}
22597 
22598 		SOCKBUF_UNLOCK(sb);
22599 	} else {
22600 		SOCKBUF_UNLOCK(sb);
22601 		if (tp->t_flags & TF_ACKNOW)
22602 			KMOD_TCPSTAT_INC(tcps_sndacks);
22603 		else if (flags & (TH_SYN | TH_FIN | TH_RST))
22604 			KMOD_TCPSTAT_INC(tcps_sndctrl);
22605 		else
22606 			KMOD_TCPSTAT_INC(tcps_sndwinup);
22607 
22608 		m = m_gethdr(M_NOWAIT, MT_DATA);
22609 		if (m == NULL) {
22610 			error = ENOBUFS;
22611 			sack_rxmit = 0;
22612 			goto out;
22613 		}
22614 #ifdef INET6
22615 		if (isipv6 && (MHLEN < hdrlen + max_linkhdr) &&
22616 		    MHLEN >= hdrlen) {
22617 			M_ALIGN(m, hdrlen);
22618 		} else
22619 #endif
22620 			m->m_data += max_linkhdr;
22621 		m->m_len = hdrlen;
22622 	}
22623 	SOCKBUF_UNLOCK_ASSERT(sb);
22624 	m->m_pkthdr.rcvif = (struct ifnet *)0;
22625 #ifdef MAC
22626 	mac_inpcb_create_mbuf(inp, m);
22627 #endif
22628 	if ((ipoptlen == 0) && (rack->r_ctl.fsb.tcp_ip_hdr) &&  rack->r_fsb_inited) {
22629 #ifdef INET6
22630 		if (isipv6)
22631 			ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
22632 		else
22633 #endif				/* INET6 */
22634 #ifdef INET
22635 			ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
22636 #endif
22637 		th = rack->r_ctl.fsb.th;
22638 		udp = rack->r_ctl.fsb.udp;
22639 		if (udp) {
22640 #ifdef INET6
22641 			if (isipv6)
22642 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
22643 			else
22644 #endif				/* INET6 */
22645 				ulen = hdrlen + len - sizeof(struct ip);
22646 			udp->uh_ulen = htons(ulen);
22647 		}
22648 	} else {
22649 #ifdef INET6
22650 		if (isipv6) {
22651 			ip6 = mtod(m, struct ip6_hdr *);
22652 			if (tp->t_port) {
22653 				udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
22654 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
22655 				udp->uh_dport = tp->t_port;
22656 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
22657 				udp->uh_ulen = htons(ulen);
22658 				th = (struct tcphdr *)(udp + 1);
22659 			} else
22660 				th = (struct tcphdr *)(ip6 + 1);
22661 			tcpip_fillheaders(inp, tp->t_port, ip6, th);
22662 		} else
22663 #endif				/* INET6 */
22664 		{
22665 #ifdef INET
22666 			ip = mtod(m, struct ip *);
22667 			if (tp->t_port) {
22668 				udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
22669 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
22670 				udp->uh_dport = tp->t_port;
22671 				ulen = hdrlen + len - sizeof(struct ip);
22672 				udp->uh_ulen = htons(ulen);
22673 				th = (struct tcphdr *)(udp + 1);
22674 			} else
22675 				th = (struct tcphdr *)(ip + 1);
22676 			tcpip_fillheaders(inp, tp->t_port, ip, th);
22677 #endif
22678 		}
22679 	}
22680 	/*
22681 	 * If we are starting a connection, send ECN setup SYN packet. If we
22682 	 * are on a retransmit, we may resend those bits a number of times
22683 	 * as per RFC 3168.
22684 	 */
22685 	if (tp->t_state == TCPS_SYN_SENT && V_tcp_do_ecn) {
22686 		flags |= tcp_ecn_output_syn_sent(tp);
22687 	}
22688 	/* Also handle parallel SYN for ECN */
22689 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
22690 	    (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))) {
22691 		int ect = tcp_ecn_output_established(tp, &flags, len, sack_rxmit);
22692 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
22693 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
22694 			tp->t_flags2 &= ~TF2_ECN_SND_ECE;
22695 #ifdef INET6
22696 		if (isipv6) {
22697 			ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
22698 			ip6->ip6_flow |= htonl(ect << 20);
22699 		}
22700 		else
22701 #endif
22702 		{
22703 #ifdef INET
22704 			ip->ip_tos &= ~IPTOS_ECN_MASK;
22705 			ip->ip_tos |= ect;
22706 #endif
22707 		}
22708 	}
22709 	th->th_seq = htonl(rack_seq);
22710 	th->th_ack = htonl(tp->rcv_nxt);
22711 	tcp_set_flags(th, flags);
22712 	/*
22713 	 * Calculate receive window.  Don't shrink window, but avoid silly
22714 	 * window syndrome.
22715 	 * If a RST segment is sent, advertise a window of zero.
22716 	 */
22717 	if (flags & TH_RST) {
22718 		recwin = 0;
22719 	} else {
22720 		if (recwin < (long)(so->so_rcv.sb_hiwat / 4) &&
22721 		    recwin < (long)segsiz) {
22722 			recwin = 0;
22723 		}
22724 		if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) &&
22725 		    recwin < (long)(tp->rcv_adv - tp->rcv_nxt))
22726 			recwin = (long)(tp->rcv_adv - tp->rcv_nxt);
22727 	}
22728 
22729 	/*
22730 	 * According to RFC1323 the window field in a SYN (i.e., a <SYN> or
22731 	 * <SYN,ACK>) segment itself is never scaled.  The <SYN,ACK> case is
22732 	 * handled in syncache.
22733 	 */
22734 	if (flags & TH_SYN)
22735 		th->th_win = htons((u_short)
22736 				   (min(sbspace(&so->so_rcv), TCP_MAXWIN)));
22737 	else {
22738 		/* Avoid shrinking window with window scaling. */
22739 		recwin = roundup2(recwin, 1 << tp->rcv_scale);
22740 		th->th_win = htons((u_short)(recwin >> tp->rcv_scale));
22741 	}
22742 	/*
22743 	 * Adjust the RXWIN0SENT flag - indicate that we have advertised a 0
22744 	 * window.  This may cause the remote transmitter to stall.  This
22745 	 * flag tells soreceive() to disable delayed acknowledgements when
22746 	 * draining the buffer.  This can occur if the receiver is
22747 	 * attempting to read more data than can be buffered prior to
22748 	 * transmitting on the connection.
22749 	 */
22750 	if (th->th_win == 0) {
22751 		tp->t_sndzerowin++;
22752 		tp->t_flags |= TF_RXWIN0SENT;
22753 	} else
22754 		tp->t_flags &= ~TF_RXWIN0SENT;
22755 	tp->snd_up = tp->snd_una;	/* drag it along, its deprecated */
22756 	/* Now are we using fsb?, if so copy the template data to the mbuf */
22757 	if ((ipoptlen == 0) && (rack->r_ctl.fsb.tcp_ip_hdr) && rack->r_fsb_inited) {
22758 		uint8_t *cpto;
22759 
22760 		cpto = mtod(m, uint8_t *);
22761 		memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
22762 		/*
22763 		 * We have just copied in:
22764 		 * IP/IP6
22765 		 * <optional udphdr>
22766 		 * tcphdr (no options)
22767 		 *
22768 		 * We need to grab the correct pointers into the mbuf
22769 		 * for both the tcp header, and possibly the udp header (if tunneling).
22770 		 * We do this by using the offset in the copy buffer and adding it
22771 		 * to the mbuf base pointer (cpto).
22772 		 */
22773 #ifdef INET6
22774 		if (isipv6)
22775 			ip6 = mtod(m, struct ip6_hdr *);
22776 		else
22777 #endif				/* INET6 */
22778 #ifdef INET
22779 			ip = mtod(m, struct ip *);
22780 #endif
22781 		th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
22782 		/* If we have a udp header lets set it into the mbuf as well */
22783 		if (udp)
22784 			udp = (struct udphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.udp - rack->r_ctl.fsb.tcp_ip_hdr));
22785 	}
22786 	if (optlen) {
22787 		bcopy(opt, th + 1, optlen);
22788 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
22789 	}
22790 	/*
22791 	 * Put TCP length in extended header, and then checksum extended
22792 	 * header and data.
22793 	 */
22794 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
22795 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
22796 	if (to.to_flags & TOF_SIGNATURE) {
22797 		/*
22798 		 * Calculate MD5 signature and put it into the place
22799 		 * determined before.
22800 		 * NOTE: since TCP options buffer doesn't point into
22801 		 * mbuf's data, calculate offset and use it.
22802 		 */
22803 		if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
22804 						       (u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
22805 			/*
22806 			 * Do not send segment if the calculation of MD5
22807 			 * digest has failed.
22808 			 */
22809 			goto out;
22810 		}
22811 	}
22812 #endif
22813 #ifdef INET6
22814 	if (isipv6) {
22815 		/*
22816 		 * ip6_plen is not need to be filled now, and will be filled
22817 		 * in ip6_output.
22818 		 */
22819 		if (tp->t_port) {
22820 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
22821 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
22822 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
22823 			th->th_sum = htons(0);
22824 			UDPSTAT_INC(udps_opackets);
22825 		} else {
22826 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
22827 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
22828 			th->th_sum = in6_cksum_pseudo(ip6,
22829 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
22830 						      0);
22831 		}
22832 	}
22833 #endif
22834 #if defined(INET6) && defined(INET)
22835 	else
22836 #endif
22837 #ifdef INET
22838 	{
22839 		if (tp->t_port) {
22840 			m->m_pkthdr.csum_flags = CSUM_UDP;
22841 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
22842 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
22843 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
22844 			th->th_sum = htons(0);
22845 			UDPSTAT_INC(udps_opackets);
22846 		} else {
22847 			m->m_pkthdr.csum_flags = CSUM_TCP;
22848 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
22849 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
22850 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
22851 									IPPROTO_TCP + len + optlen));
22852 		}
22853 		/* IP version must be set here for ipv4/ipv6 checking later */
22854 		KASSERT(ip->ip_v == IPVERSION,
22855 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
22856 	}
22857 #endif
22858 	/*
22859 	 * Enable TSO and specify the size of the segments. The TCP pseudo
22860 	 * header checksum is always provided. XXX: Fixme: This is currently
22861 	 * not the case for IPv6.
22862 	 */
22863 	if (tso) {
22864 		/*
22865 		 * Here we must use t_maxseg and the optlen since
22866 		 * the optlen may include SACK's (or DSACK).
22867 		 */
22868 		KASSERT(len > tp->t_maxseg - optlen,
22869 			("%s: len <= tso_segsz", __func__));
22870 		m->m_pkthdr.csum_flags |= CSUM_TSO;
22871 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
22872 	}
22873 	KASSERT(len + hdrlen == m_length(m, NULL),
22874 		("%s: mbuf chain different than expected: %d + %u != %u",
22875 		 __func__, len, hdrlen, m_length(m, NULL)));
22876 
22877 #ifdef TCP_HHOOK
22878 	/* Run HHOOK_TCP_ESTABLISHED_OUT helper hooks. */
22879 	hhook_run_tcp_est_out(tp, th, &to, len, tso);
22880 #endif
22881 	if ((rack->r_ctl.crte != NULL) &&
22882 	    (rack->rc_hw_nobuf == 0) &&
22883 	    tcp_bblogging_on(tp)) {
22884 		rack_log_queue_level(tp, rack, len, &tv, cts);
22885 	}
22886 	/* We're getting ready to send; log now. */
22887 	if (tcp_bblogging_on(rack->rc_tp)) {
22888 		union tcp_log_stackspecific log;
22889 
22890 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
22891 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
22892 		if (rack->rack_no_prr)
22893 			log.u_bbr.flex1 = 0;
22894 		else
22895 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
22896 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
22897 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
22898 		log.u_bbr.flex4 = orig_len;
22899 		/* Save off the early/late values */
22900 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
22901 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
22902 		log.u_bbr.bw_inuse = rack_get_bw(rack);
22903 		log.u_bbr.cur_del_rate = rack->r_ctl.gp_bw;
22904 		log.u_bbr.flex8 = 0;
22905 		if (rsm) {
22906 			if (rsm->r_flags & RACK_RWND_COLLAPSED) {
22907 				rack_log_collapse(rack, rsm->r_start, rsm->r_end, 0, __LINE__, 5, rsm->r_flags, rsm);
22908 				counter_u64_add(rack_collapsed_win_rxt, 1);
22909 				counter_u64_add(rack_collapsed_win_rxt_bytes, (rsm->r_end - rsm->r_start));
22910 			}
22911 			if (doing_tlp)
22912 				log.u_bbr.flex8 = 2;
22913 			else
22914 				log.u_bbr.flex8 = 1;
22915 		} else {
22916 			if (doing_tlp)
22917 				log.u_bbr.flex8 = 3;
22918 		}
22919 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
22920 		log.u_bbr.flex7 = mark;
22921 		log.u_bbr.flex7 <<= 8;
22922 		log.u_bbr.flex7 |= pass;
22923 		log.u_bbr.pkts_out = tp->t_maxseg;
22924 		log.u_bbr.timeStamp = cts;
22925 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
22926 		if (rsm && (rsm->r_rtr_cnt > 0)) {
22927 			/*
22928 			 * When we have a retransmit we want to log the
22929 			 * burst at send and flight at send from before.
22930 			 */
22931 			log.u_bbr.flex5 = rsm->r_fas;
22932 			log.u_bbr.bbr_substate = rsm->r_bas;
22933 		} else {
22934 			/*
22935 			 * New transmits we log in flex5 the inflight again as
22936 			 * well as the number of segments in our send in the
22937 			 * substate field.
22938 			 */
22939 			log.u_bbr.flex5 = log.u_bbr.inflight;
22940 			log.u_bbr.bbr_substate = (uint8_t)((len + segsiz - 1)/segsiz);
22941 		}
22942 		log.u_bbr.lt_epoch = cwnd_to_use;
22943 		log.u_bbr.delivered = sendalot;
22944 		log.u_bbr.rttProp = (uint64_t)rsm;
22945 		log.u_bbr.pkt_epoch = __LINE__;
22946 		if (rsm) {
22947 			log.u_bbr.delRate = rsm->r_flags;
22948 			log.u_bbr.delRate <<= 31;
22949 			log.u_bbr.delRate |= rack->r_must_retran;
22950 			log.u_bbr.delRate <<= 1;
22951 			log.u_bbr.delRate |= (sack_rxmit & 0x00000001);
22952 		} else {
22953 			log.u_bbr.delRate = rack->r_must_retran;
22954 			log.u_bbr.delRate <<= 1;
22955 			log.u_bbr.delRate |= (sack_rxmit & 0x00000001);
22956 		}
22957 		lgb = tcp_log_event(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_OUT, ERRNO_UNK,
22958 				    len, &log, false, NULL, __func__, __LINE__, &tv);
22959 	} else
22960 		lgb = NULL;
22961 
22962 	/*
22963 	 * Fill in IP length and desired time to live and send to IP level.
22964 	 * There should be a better way to handle ttl and tos; we could keep
22965 	 * them in the template, but need a way to checksum without them.
22966 	 */
22967 	/*
22968 	 * m->m_pkthdr.len should have been set before cksum calcuration,
22969 	 * because in6_cksum() need it.
22970 	 */
22971 #ifdef INET6
22972 	if (isipv6) {
22973 		/*
22974 		 * we separately set hoplimit for every segment, since the
22975 		 * user might want to change the value via setsockopt. Also,
22976 		 * desired default hop limit might be changed via Neighbor
22977 		 * Discovery.
22978 		 */
22979 		rack->r_ctl.fsb.hoplimit = ip6->ip6_hlim = in6_selecthlim(inp, NULL);
22980 
22981 		/*
22982 		 * Set the packet size here for the benefit of DTrace
22983 		 * probes. ip6_output() will set it properly; it's supposed
22984 		 * to include the option header lengths as well.
22985 		 */
22986 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
22987 
22988 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
22989 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
22990 		else
22991 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
22992 
22993 		if (tp->t_state == TCPS_SYN_SENT)
22994 			TCP_PROBE5(connect__request, NULL, tp, ip6, tp, th);
22995 
22996 		TCP_PROBE5(send, NULL, tp, ip6, tp, th);
22997 		/* TODO: IPv6 IP6TOS_ECT bit on */
22998 		error = ip6_output(m,
22999 				   inp->in6p_outputopts,
23000 				   &inp->inp_route6,
23001 				   ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0),
23002 				   NULL, NULL, inp);
23003 
23004 		if (error == EMSGSIZE && inp->inp_route6.ro_nh != NULL)
23005 			mtu = inp->inp_route6.ro_nh->nh_mtu;
23006 	}
23007 #endif				/* INET6 */
23008 #if defined(INET) && defined(INET6)
23009 	else
23010 #endif
23011 #ifdef INET
23012 	{
23013 		ip->ip_len = htons(m->m_pkthdr.len);
23014 #ifdef INET6
23015 		if (inp->inp_vflag & INP_IPV6PROTO)
23016 			ip->ip_ttl = in6_selecthlim(inp, NULL);
23017 #endif				/* INET6 */
23018 		rack->r_ctl.fsb.hoplimit = ip->ip_ttl;
23019 		/*
23020 		 * If we do path MTU discovery, then we set DF on every
23021 		 * packet. This might not be the best thing to do according
23022 		 * to RFC3390 Section 2. However the tcp hostcache migitates
23023 		 * the problem so it affects only the first tcp connection
23024 		 * with a host.
23025 		 *
23026 		 * NB: Don't set DF on small MTU/MSS to have a safe
23027 		 * fallback.
23028 		 */
23029 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
23030 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
23031 			if (tp->t_port == 0 || len < V_tcp_minmss) {
23032 				ip->ip_off |= htons(IP_DF);
23033 			}
23034 		} else {
23035 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
23036 		}
23037 
23038 		if (tp->t_state == TCPS_SYN_SENT)
23039 			TCP_PROBE5(connect__request, NULL, tp, ip, tp, th);
23040 
23041 		TCP_PROBE5(send, NULL, tp, ip, tp, th);
23042 
23043 		error = ip_output(m,
23044 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
23045 				  inp->inp_options,
23046 #else
23047 				  NULL,
23048 #endif
23049 				  &inp->inp_route,
23050 				  ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0), 0,
23051 				  inp);
23052 		if (error == EMSGSIZE && inp->inp_route.ro_nh != NULL)
23053 			mtu = inp->inp_route.ro_nh->nh_mtu;
23054 	}
23055 #endif				/* INET */
23056 	if (lgb) {
23057 		lgb->tlb_errno = error;
23058 		lgb = NULL;
23059 	}
23060 
23061 out:
23062 	/*
23063 	 * In transmit state, time the transmission and arrange for the
23064 	 * retransmit.  In persist state, just set snd_max.
23065 	 */
23066 	rack_log_output(tp, &to, len, rack_seq, (uint8_t) flags, error,
23067 			rack_to_usec_ts(&tv),
23068 			rsm, add_flag, s_mb, s_moff, hw_tls, segsiz);
23069 	if (error == 0) {
23070 		if (add_flag & RACK_IS_PCM) {
23071 			/* We just launched a PCM */
23072 			/* rrs here log */
23073 			rack->pcm_in_progress = 1;
23074 			rack->pcm_needed = 0;
23075 			rack_log_pcm(rack, 7, len, rack->r_ctl.pcm_max_seg,  add_flag);
23076 		}
23077 		if (rsm == NULL) {
23078 			if (rack->lt_bw_up == 0) {
23079 				rack->r_ctl.lt_timemark = tcp_tv_to_lusectick(&tv);
23080 				rack->r_ctl.lt_seq = tp->snd_una;
23081 				rack->lt_bw_up = 1;
23082 			} else if (((rack_seq + len) - rack->r_ctl.lt_seq) > 0x7fffffff) {
23083 				/*
23084 				 * Need to record what we have since we are
23085 				 * approaching seq wrap.
23086 				 */
23087 				uint64_t tmark;
23088 
23089 				rack->r_ctl.lt_bw_bytes += (tp->snd_una - rack->r_ctl.lt_seq);
23090 				rack->r_ctl.lt_seq = tp->snd_una;
23091 				tmark = tcp_get_u64_usecs(&tv);
23092 				if (tmark > rack->r_ctl.lt_timemark) {
23093 					rack->r_ctl.lt_bw_time += (tmark - rack->r_ctl.lt_timemark);
23094 					rack->r_ctl.lt_timemark = tmark;
23095 				}
23096 			}
23097 		}
23098 		rack->forced_ack = 0;	/* If we send something zap the FA flag */
23099 		counter_u64_add(rack_total_bytes, len);
23100 		tcp_account_for_send(tp, len, (rsm != NULL), doing_tlp, hw_tls);
23101 		if (rsm && doing_tlp) {
23102 			rack->rc_last_sent_tlp_past_cumack = 0;
23103 			rack->rc_last_sent_tlp_seq_valid = 1;
23104 			rack->r_ctl.last_sent_tlp_seq = rsm->r_start;
23105 			rack->r_ctl.last_sent_tlp_len = rsm->r_end - rsm->r_start;
23106 		}
23107 		if (rack->rc_hw_nobuf) {
23108 			rack->rc_hw_nobuf = 0;
23109 			rack->r_ctl.rc_agg_delayed = 0;
23110 			rack->r_early = 0;
23111 			rack->r_late = 0;
23112 			rack->r_ctl.rc_agg_early = 0;
23113 		}
23114 		if (rsm && (doing_tlp == 0)) {
23115 			/* Set we retransmitted */
23116 			rack->rc_gp_saw_rec = 1;
23117 		} else {
23118 			if (cwnd_to_use > tp->snd_ssthresh) {
23119 				/* Set we sent in CA */
23120 				rack->rc_gp_saw_ca = 1;
23121 			} else {
23122 				/* Set we sent in SS */
23123 				rack->rc_gp_saw_ss = 1;
23124 			}
23125 		}
23126 		if (TCPS_HAVEESTABLISHED(tp->t_state) &&
23127 		    (tp->t_flags & TF_SACK_PERMIT) &&
23128 		    tp->rcv_numsacks > 0)
23129 			tcp_clean_dsack_blocks(tp);
23130 		tot_len_this_send += len;
23131 		if (len == 0) {
23132 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_SNDACK], 1);
23133 		} else {
23134 			int idx;
23135 
23136 			idx = (len / segsiz) + 3;
23137 			if (idx >= TCP_MSS_ACCT_ATIMER)
23138 				counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
23139 			else
23140 				counter_u64_add(rack_out_size[idx], 1);
23141 		}
23142 	}
23143 	if ((rack->rack_no_prr == 0) &&
23144 	    sub_from_prr &&
23145 	    (error == 0)) {
23146 		if (rack->r_ctl.rc_prr_sndcnt >= len)
23147 			rack->r_ctl.rc_prr_sndcnt -= len;
23148 		else
23149 			rack->r_ctl.rc_prr_sndcnt = 0;
23150 	}
23151 	sub_from_prr = 0;
23152 	if (doing_tlp) {
23153 		/* Make sure the TLP is added */
23154 		add_flag |= RACK_TLP;
23155 	} else if (rsm) {
23156 		/* If its a resend without TLP then it must not have the flag */
23157 		rsm->r_flags &= ~RACK_TLP;
23158 	}
23159 
23160 
23161 	if ((error == 0) &&
23162 	    (len > 0) &&
23163 	    (tp->snd_una == tp->snd_max))
23164 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
23165 
23166 	{
23167 		/*
23168 		 * This block is not associated with the above error == 0 test.
23169 		 * It is used to advance snd_max if we have a new transmit.
23170 		 */
23171 		tcp_seq startseq = tp->snd_max;
23172 
23173 
23174 		if (rsm && (doing_tlp == 0))
23175 			rack->r_ctl.rc_loss_count += rsm->r_end - rsm->r_start;
23176 		if (error)
23177 			/* We don't log or do anything with errors */
23178 			goto nomore;
23179 		if (doing_tlp == 0) {
23180 			if (rsm == NULL) {
23181 				/*
23182 				 * Not a retransmission of some
23183 				 * sort, new data is going out so
23184 				 * clear our TLP count and flag.
23185 				 */
23186 				rack->rc_tlp_in_progress = 0;
23187 				rack->r_ctl.rc_tlp_cnt_out = 0;
23188 			}
23189 		} else {
23190 			/*
23191 			 * We have just sent a TLP, mark that it is true
23192 			 * and make sure our in progress is set so we
23193 			 * continue to check the count.
23194 			 */
23195 			rack->rc_tlp_in_progress = 1;
23196 			rack->r_ctl.rc_tlp_cnt_out++;
23197 		}
23198 		/*
23199 		 * If we are retransmitting we are done, snd_max
23200 		 * does not get updated.
23201 		 */
23202 		if (sack_rxmit)
23203 			goto nomore;
23204 		if ((tp->snd_una == tp->snd_max) && (len > 0)) {
23205 			/*
23206 			 * Update the time we just added data since
23207 			 * nothing was outstanding.
23208 			 */
23209 			rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
23210 			tp->t_acktime = ticks;
23211 		}
23212 		/*
23213 		 * Now for special SYN/FIN handling.
23214 		 */
23215 		if (flags & (TH_SYN | TH_FIN)) {
23216 			if ((flags & TH_SYN) &&
23217 			    ((tp->t_flags & TF_SENTSYN) == 0)) {
23218 				tp->snd_max++;
23219 				tp->t_flags |= TF_SENTSYN;
23220 			}
23221 			if ((flags & TH_FIN) &&
23222 			    ((tp->t_flags & TF_SENTFIN) == 0)) {
23223 				tp->snd_max++;
23224 				tp->t_flags |= TF_SENTFIN;
23225 			}
23226 		}
23227 		tp->snd_max += len;
23228 		if (rack->rc_new_rnd_needed) {
23229 			rack_new_round_starts(tp, rack, tp->snd_max);
23230 		}
23231 		/*
23232 		 * Time this transmission if not a retransmission and
23233 		 * not currently timing anything.
23234 		 * This is only relevant in case of switching back to
23235 		 * the base stack.
23236 		 */
23237 		if (tp->t_rtttime == 0) {
23238 			tp->t_rtttime = ticks;
23239 			tp->t_rtseq = startseq;
23240 			KMOD_TCPSTAT_INC(tcps_segstimed);
23241 		}
23242 		if (len &&
23243 		    ((tp->t_flags & TF_GPUTINPROG) == 0))
23244 			rack_start_gp_measurement(tp, rack, startseq, sb_offset);
23245 		/*
23246 		 * If we are doing FO we need to update the mbuf position and subtract
23247 		 * this happens when the peer sends us duplicate information and
23248 		 * we thus want to send a DSACK.
23249 		 *
23250 		 * XXXRRS: This brings to mind a ?, when we send a DSACK block is TSO
23251 		 * turned off? If not then we are going to echo multiple DSACK blocks
23252 		 * out (with the TSO), which we should not be doing.
23253 		 */
23254 		if (rack->r_fast_output && len) {
23255 			if (rack->r_ctl.fsb.left_to_send > len)
23256 				rack->r_ctl.fsb.left_to_send -= len;
23257 			else
23258 				rack->r_ctl.fsb.left_to_send = 0;
23259 			if (rack->r_ctl.fsb.left_to_send < segsiz)
23260 				rack->r_fast_output = 0;
23261 			if (rack->r_fast_output) {
23262 				rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
23263 				rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
23264 				rack->r_ctl.fsb.o_t_len = M_TRAILINGROOM(rack->r_ctl.fsb.m);
23265 			}
23266 		}
23267 		if (rack_pcm_blast == 0) {
23268 			if ((orig_len > len) &&
23269 			    (add_flag & RACK_IS_PCM) &&
23270 			    (len < pace_max_seg) &&
23271 			    ((pace_max_seg - len) > segsiz)) {
23272 				/*
23273 				 * We are doing a PCM measurement and we did
23274 				 * not get enough data in the TSO to meet the
23275 				 * burst requirement.
23276 				 */
23277 				uint32_t n_len;
23278 
23279 				n_len = (orig_len - len);
23280 				orig_len -= len;
23281 				pace_max_seg -= len;
23282 				len = n_len;
23283 				sb_offset = tp->snd_max - tp->snd_una;
23284 				/* Re-lock for the next spin */
23285 				SOCKBUF_LOCK(sb);
23286 				goto send;
23287 			}
23288 		} else {
23289 			if ((orig_len > len) &&
23290 			    (add_flag & RACK_IS_PCM) &&
23291 			    ((orig_len - len) > segsiz)) {
23292 				/*
23293 				 * We are doing a PCM measurement and we did
23294 				 * not get enough data in the TSO to meet the
23295 				 * burst requirement.
23296 				 */
23297 				uint32_t n_len;
23298 
23299 				n_len = (orig_len - len);
23300 				orig_len -= len;
23301 				len = n_len;
23302 				sb_offset = tp->snd_max - tp->snd_una;
23303 				/* Re-lock for the next spin */
23304 				SOCKBUF_LOCK(sb);
23305 				goto send;
23306 			}
23307 		}
23308 	}
23309 nomore:
23310 	if (error) {
23311 		rack->r_ctl.rc_agg_delayed = 0;
23312 		rack->r_early = 0;
23313 		rack->r_late = 0;
23314 		rack->r_ctl.rc_agg_early = 0;
23315 		SOCKBUF_UNLOCK_ASSERT(sb);	/* Check gotos. */
23316 		/*
23317 		 * Failures do not advance the seq counter above. For the
23318 		 * case of ENOBUFS we will fall out and retry in 1ms with
23319 		 * the hpts. Everything else will just have to retransmit
23320 		 * with the timer.
23321 		 *
23322 		 * In any case, we do not want to loop around for another
23323 		 * send without a good reason.
23324 		 */
23325 		sendalot = 0;
23326 		switch (error) {
23327 		case EPERM:
23328 		case EACCES:
23329 			tp->t_softerror = error;
23330 #ifdef TCP_ACCOUNTING
23331 			crtsc = get_cyclecount();
23332 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
23333 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
23334 			}
23335 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
23336 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
23337 			}
23338 			sched_unpin();
23339 #endif
23340 			return (error);
23341 		case ENOBUFS:
23342 			/*
23343 			 * Pace us right away to retry in a some
23344 			 * time
23345 			 */
23346 			if (rack->r_ctl.crte != NULL) {
23347 				tcp_trace_point(rack->rc_tp, TCP_TP_HWENOBUF);
23348 				if (tcp_bblogging_on(rack->rc_tp))
23349 					rack_log_queue_level(tp, rack, len, &tv, cts);
23350 			} else
23351 				tcp_trace_point(rack->rc_tp, TCP_TP_ENOBUF);
23352 			slot = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
23353 			if (rack->rc_enobuf < 0x7f)
23354 				rack->rc_enobuf++;
23355 			if (slot < (10 * HPTS_USEC_IN_MSEC))
23356 				slot = 10 * HPTS_USEC_IN_MSEC;
23357 			if (rack->r_ctl.crte != NULL) {
23358 				counter_u64_add(rack_saw_enobuf_hw, 1);
23359 				tcp_rl_log_enobuf(rack->r_ctl.crte);
23360 			}
23361 			counter_u64_add(rack_saw_enobuf, 1);
23362 			goto enobufs;
23363 		case EMSGSIZE:
23364 			/*
23365 			 * For some reason the interface we used initially
23366 			 * to send segments changed to another or lowered
23367 			 * its MTU. If TSO was active we either got an
23368 			 * interface without TSO capabilits or TSO was
23369 			 * turned off. If we obtained mtu from ip_output()
23370 			 * then update it and try again.
23371 			 */
23372 			if (tso)
23373 				tp->t_flags &= ~TF_TSO;
23374 			if (mtu != 0) {
23375 				int saved_mtu;
23376 
23377 				saved_mtu = tp->t_maxseg;
23378 				tcp_mss_update(tp, -1, mtu, NULL, NULL);
23379 				if (saved_mtu > tp->t_maxseg) {
23380 					goto again;
23381 				}
23382 			}
23383 			slot = 10 * HPTS_USEC_IN_MSEC;
23384 			rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
23385 #ifdef TCP_ACCOUNTING
23386 			crtsc = get_cyclecount();
23387 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
23388 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
23389 			}
23390 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
23391 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
23392 			}
23393 			sched_unpin();
23394 #endif
23395 			return (error);
23396 		case ENETUNREACH:
23397 			counter_u64_add(rack_saw_enetunreach, 1);
23398 		case EHOSTDOWN:
23399 		case EHOSTUNREACH:
23400 		case ENETDOWN:
23401 			if (TCPS_HAVERCVDSYN(tp->t_state)) {
23402 				tp->t_softerror = error;
23403 			}
23404 			/* FALLTHROUGH */
23405 		default:
23406 			slot = 10 * HPTS_USEC_IN_MSEC;
23407 			rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
23408 #ifdef TCP_ACCOUNTING
23409 			crtsc = get_cyclecount();
23410 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
23411 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
23412 			}
23413 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
23414 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
23415 			}
23416 			sched_unpin();
23417 #endif
23418 			return (error);
23419 		}
23420 	} else {
23421 		rack->rc_enobuf = 0;
23422 		if (IN_FASTRECOVERY(tp->t_flags) && rsm)
23423 			rack->r_ctl.retran_during_recovery += len;
23424 	}
23425 	KMOD_TCPSTAT_INC(tcps_sndtotal);
23426 
23427 	/*
23428 	 * Data sent (as far as we can tell). If this advertises a larger
23429 	 * window than any other segment, then remember the size of the
23430 	 * advertised window. Any pending ACK has now been sent.
23431 	 */
23432 	if (recwin > 0 && SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv))
23433 		tp->rcv_adv = tp->rcv_nxt + recwin;
23434 
23435 	tp->last_ack_sent = tp->rcv_nxt;
23436 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
23437 enobufs:
23438 	if (sendalot) {
23439 		/* Do we need to turn off sendalot? */
23440 		if (pace_max_seg &&
23441 		    (tot_len_this_send >= pace_max_seg)) {
23442 			/* We hit our max. */
23443 			sendalot = 0;
23444 		}
23445 	}
23446 	if ((error == 0) && (flags & TH_FIN))
23447 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_FIN);
23448 	if (flags & TH_RST) {
23449 		/*
23450 		 * We don't send again after sending a RST.
23451 		 */
23452 		slot = 0;
23453 		sendalot = 0;
23454 		if (error == 0)
23455 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
23456 	} else if ((slot == 0) && (sendalot == 0) && tot_len_this_send) {
23457 		/*
23458 		 * Get our pacing rate, if an error
23459 		 * occurred in sending (ENOBUF) we would
23460 		 * hit the else if with slot preset. Other
23461 		 * errors return.
23462 		 */
23463 		slot = rack_get_pacing_delay(rack, tp, tot_len_this_send, rsm, segsiz, __LINE__);
23464 	}
23465 	/* We have sent clear the flag */
23466 	rack->r_ent_rec_ns = 0;
23467 	if (rack->r_must_retran) {
23468 		if (rsm) {
23469 			rack->r_ctl.rc_out_at_rto -= (rsm->r_end - rsm->r_start);
23470 			if (SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) {
23471 				/*
23472 				 * We have retransmitted all.
23473 				 */
23474 				rack->r_must_retran = 0;
23475 				rack->r_ctl.rc_out_at_rto = 0;
23476 			}
23477 		} else if (SEQ_GEQ(tp->snd_max, rack->r_ctl.rc_snd_max_at_rto)) {
23478 			/*
23479 			 * Sending new data will also kill
23480 			 * the loop.
23481 			 */
23482 			rack->r_must_retran = 0;
23483 			rack->r_ctl.rc_out_at_rto = 0;
23484 		}
23485 	}
23486 	rack->r_ctl.fsb.recwin = recwin;
23487 	if ((tp->t_flags & (TF_WASCRECOVERY|TF_WASFRECOVERY)) &&
23488 	    SEQ_GT(tp->snd_max, rack->r_ctl.rc_snd_max_at_rto)) {
23489 		/*
23490 		 * We hit an RTO and now have past snd_max at the RTO
23491 		 * clear all the WAS flags.
23492 		 */
23493 		tp->t_flags &= ~(TF_WASCRECOVERY|TF_WASFRECOVERY);
23494 	}
23495 	if (slot) {
23496 		/* set the rack tcb into the slot N */
23497 		if ((error == 0) &&
23498 		    rack_use_rfo &&
23499 		    ((flags & (TH_SYN|TH_FIN)) == 0) &&
23500 		    (rsm == NULL) &&
23501 		    (ipoptlen == 0) &&
23502 		    (tp->rcv_numsacks == 0) &&
23503 		    (rack->rc_policer_detected == 0)  &&
23504 		    rack->r_fsb_inited &&
23505 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
23506 		    ((IN_RECOVERY(tp->t_flags)) == 0) &&
23507 		    (rack->r_must_retran == 0) &&
23508 		    ((tp->t_flags & TF_NEEDFIN) == 0) &&
23509 		    (len > 0) && (orig_len > 0) &&
23510 		    (orig_len > len) &&
23511 		    ((orig_len - len) >= segsiz) &&
23512 		    ((optlen == 0) ||
23513 		     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
23514 			/* We can send at least one more MSS using our fsb */
23515 			rack_setup_fast_output(tp, rack, sb, len, orig_len,
23516 					       segsiz, pace_max_seg, hw_tls, flags);
23517 		} else
23518 			rack->r_fast_output = 0;
23519 		rack_log_fsb(rack, tp, so, flags,
23520 			     ipoptlen, orig_len, len, error,
23521 			     (rsm == NULL), optlen, __LINE__, 2);
23522 	} else if (sendalot) {
23523 		int ret;
23524 
23525 		sack_rxmit = 0;
23526 		if ((error == 0) &&
23527 		    rack_use_rfo &&
23528 		    ((flags & (TH_SYN|TH_FIN)) == 0) &&
23529 		    (rsm == NULL) &&
23530 		    (ipoptlen == 0) &&
23531 		    (tp->rcv_numsacks == 0) &&
23532 		    (rack->r_must_retran == 0) &&
23533 		    rack->r_fsb_inited &&
23534 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
23535 		    ((IN_RECOVERY(tp->t_flags)) == 0) &&
23536 		    ((tp->t_flags & TF_NEEDFIN) == 0) &&
23537 		    (len > 0) && (orig_len > 0) &&
23538 		    (orig_len > len) &&
23539 		    ((orig_len - len) >= segsiz) &&
23540 		    ((optlen == 0) ||
23541 		     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
23542 			/* we can use fast_output for more */
23543 			rack_setup_fast_output(tp, rack, sb, len, orig_len,
23544 					       segsiz, pace_max_seg, hw_tls, flags);
23545 			if (rack->r_fast_output) {
23546 				error = 0;
23547 				ret = rack_fast_output(tp, rack, ts_val, cts, ms_cts, &tv, tot_len_this_send, &error);
23548 				if (ret >= 0)
23549 					return (ret);
23550 			        else if (error)
23551 					goto nomore;
23552 
23553 			}
23554 		}
23555 		goto again;
23556 	}
23557 skip_all_send:
23558 	/* Assure when we leave that snd_nxt will point to top */
23559 	if (SEQ_GT(tp->snd_max, tp->snd_nxt))
23560 		tp->snd_nxt = tp->snd_max;
23561 	rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, 0);
23562 #ifdef TCP_ACCOUNTING
23563 	crtsc = get_cyclecount() - ts_val;
23564 	if (tot_len_this_send) {
23565 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
23566 			tp->tcp_cnt_counters[SND_OUT_DATA]++;
23567 		}
23568 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
23569 			tp->tcp_proc_time[SND_OUT_DATA] += crtsc;
23570 		}
23571 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
23572 			tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len_this_send + segsiz - 1) /segsiz);
23573 		}
23574 	} else {
23575 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
23576 			tp->tcp_cnt_counters[SND_OUT_ACK]++;
23577 		}
23578 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
23579 			tp->tcp_proc_time[SND_OUT_ACK] += crtsc;
23580 		}
23581 	}
23582 	sched_unpin();
23583 #endif
23584 	if (error == ENOBUFS)
23585 		error = 0;
23586 	return (error);
23587 }
23588 
23589 static void
rack_update_seg(struct tcp_rack * rack)23590 rack_update_seg(struct tcp_rack *rack)
23591 {
23592 	uint32_t orig_val;
23593 
23594 	orig_val = rack->r_ctl.rc_pace_max_segs;
23595 	rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
23596 	if (orig_val != rack->r_ctl.rc_pace_max_segs)
23597 		rack_log_pacing_delay_calc(rack, 0, 0, orig_val, 0, 0, 15, __LINE__, NULL, 0);
23598 }
23599 
23600 static void
rack_mtu_change(struct tcpcb * tp)23601 rack_mtu_change(struct tcpcb *tp)
23602 {
23603 	/*
23604 	 * The MSS may have changed
23605 	 */
23606 	struct tcp_rack *rack;
23607 	struct rack_sendmap *rsm;
23608 
23609 	rack = (struct tcp_rack *)tp->t_fb_ptr;
23610 	if (rack->r_ctl.rc_pace_min_segs != ctf_fixed_maxseg(tp)) {
23611 		/*
23612 		 * The MTU has changed we need to resend everything
23613 		 * since all we have sent is lost. We first fix
23614 		 * up the mtu though.
23615 		 */
23616 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
23617 		/* We treat this like a full retransmit timeout without the cwnd adjustment */
23618 		rack_remxt_tmr(tp);
23619 		rack->r_fast_output = 0;
23620 		rack->r_ctl.rc_out_at_rto = ctf_flight_size(tp,
23621 						rack->r_ctl.rc_sacked);
23622 		rack->r_ctl.rc_snd_max_at_rto = tp->snd_max;
23623 		rack->r_must_retran = 1;
23624 		/* Mark all inflight to needing to be rxt'd */
23625 		TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
23626 			rsm->r_flags |= (RACK_MUST_RXT|RACK_PMTU_CHG);
23627 		}
23628 	}
23629 	sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
23630 	/* We don't use snd_nxt to retransmit */
23631 	tp->snd_nxt = tp->snd_max;
23632 }
23633 
23634 static int
rack_set_dgp(struct tcp_rack * rack)23635 rack_set_dgp(struct tcp_rack *rack)
23636 {
23637 	if (rack->dgp_on == 1)
23638 		return(0);
23639 	if ((rack->use_fixed_rate == 1) &&
23640 	    (rack->rc_always_pace == 1)) {
23641 		/*
23642 		 * We are already pacing another
23643 		 * way.
23644 		 */
23645 		return (EBUSY);
23646 	}
23647 	if (rack->rc_always_pace == 1) {
23648 		rack_remove_pacing(rack);
23649 	}
23650 	if (tcp_incr_dgp_pacing_cnt() == 0)
23651 		return (ENOSPC);
23652 	rack->r_ctl.pacing_method |= RACK_DGP_PACING;
23653 	rack->rc_fillcw_apply_discount = 0;
23654 	rack->dgp_on = 1;
23655 	rack->rc_always_pace = 1;
23656 	rack->rc_pace_dnd = 1;
23657 	rack->use_fixed_rate = 0;
23658 	if (rack->gp_ready)
23659 		rack_set_cc_pacing(rack);
23660 	rack->rc_tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
23661 	rack->rack_attempt_hdwr_pace = 0;
23662 	/* rxt settings */
23663 	rack->full_size_rxt = 1;
23664 	rack->shape_rxt_to_pacing_min  = 0;
23665 	/* cmpack=1 */
23666 	rack->r_use_cmp_ack = 1;
23667 	if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state) &&
23668 	    rack->r_use_cmp_ack)
23669 		rack->rc_tp->t_flags2 |= TF2_MBUF_ACKCMP;
23670 	/* scwnd=1 */
23671 	rack->rack_enable_scwnd = 1;
23672 	/* dynamic=100 */
23673 	rack->rc_gp_dyn_mul = 1;
23674 	/* gp_inc_ca */
23675 	rack->r_ctl.rack_per_of_gp_ca = 100;
23676 	/* rrr_conf=3 */
23677 	rack->r_rr_config = 3;
23678 	/* npush=2 */
23679 	rack->r_ctl.rc_no_push_at_mrtt = 2;
23680 	/* fillcw=1 */
23681 	rack->rc_pace_to_cwnd = 1;
23682 	rack->rc_pace_fill_if_rttin_range = 0;
23683 	rack->rtt_limit_mul = 0;
23684 	/* noprr=1 */
23685 	rack->rack_no_prr = 1;
23686 	/* lscwnd=1 */
23687 	rack->r_limit_scw = 1;
23688 	/* gp_inc_rec */
23689 	rack->r_ctl.rack_per_of_gp_rec = 90;
23690 	return (0);
23691 }
23692 
23693 static int
rack_set_profile(struct tcp_rack * rack,int prof)23694 rack_set_profile(struct tcp_rack *rack, int prof)
23695 {
23696 	int err = EINVAL;
23697 	if (prof == 1) {
23698 		/*
23699 		 * Profile 1 is "standard" DGP. It ignores
23700 		 * client buffer level.
23701 		 */
23702 		err = rack_set_dgp(rack);
23703 		if (err)
23704 			return (err);
23705 	} else if (prof == 6) {
23706 		err = rack_set_dgp(rack);
23707 		if (err)
23708 			return (err);
23709 		/*
23710 		 * Profile 6 tweaks DGP so that it will apply to
23711 		 * fill-cw the same settings that profile5 does
23712 		 * to replace DGP. It gets then the max(dgp-rate, fillcw(discounted).
23713 		 */
23714 		rack->rc_fillcw_apply_discount = 1;
23715 	} else if (prof == 0) {
23716 		/* This changes things back to the default settings */
23717 		if (rack->rc_always_pace == 1) {
23718 			rack_remove_pacing(rack);
23719 		} else {
23720 			/* Make sure any stray flags are off */
23721 			rack->dgp_on = 0;
23722 			rack->rc_hybrid_mode = 0;
23723 			rack->use_fixed_rate = 0;
23724 		}
23725 		err = 0;
23726 		if (rack_fill_cw_state)
23727 			rack->rc_pace_to_cwnd = 1;
23728 		else
23729 			rack->rc_pace_to_cwnd = 0;
23730 
23731 		if (rack_pace_every_seg && tcp_can_enable_pacing()) {
23732 			rack->r_ctl.pacing_method |= RACK_REG_PACING;
23733 			rack->rc_always_pace = 1;
23734 			if (rack->rack_hibeta)
23735 				rack_set_cc_pacing(rack);
23736 		} else
23737 			rack->rc_always_pace = 0;
23738 		if (rack_dsack_std_based & 0x1) {
23739 			/* Basically this means all rack timers are at least (srtt + 1/4 srtt) */
23740 			rack->rc_rack_tmr_std_based = 1;
23741 		}
23742 		if (rack_dsack_std_based & 0x2) {
23743 			/* Basically this means  rack timers are extended based on dsack by up to (2 * srtt) */
23744 			rack->rc_rack_use_dsack = 1;
23745 		}
23746 		if (rack_use_cmp_acks)
23747 			rack->r_use_cmp_ack = 1;
23748 		else
23749 			rack->r_use_cmp_ack = 0;
23750 		if (rack_disable_prr)
23751 			rack->rack_no_prr = 1;
23752 		else
23753 			rack->rack_no_prr = 0;
23754 		if (rack_gp_no_rec_chg)
23755 			rack->rc_gp_no_rec_chg = 1;
23756 		else
23757 			rack->rc_gp_no_rec_chg = 0;
23758 		if (rack_enable_mqueue_for_nonpaced || rack->r_use_cmp_ack) {
23759 			rack->r_mbuf_queue = 1;
23760 			if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state))
23761 				rack->rc_tp->t_flags2 |= TF2_MBUF_ACKCMP;
23762 			rack->rc_tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
23763 		} else {
23764 			rack->r_mbuf_queue = 0;
23765 			rack->rc_tp->t_flags2 &= ~TF2_SUPPORTS_MBUFQ;
23766 		}
23767 		if (rack_enable_shared_cwnd)
23768 			rack->rack_enable_scwnd = 1;
23769 		else
23770 			rack->rack_enable_scwnd = 0;
23771 		if (rack_do_dyn_mul) {
23772 			/* When dynamic adjustment is on CA needs to start at 100% */
23773 			rack->rc_gp_dyn_mul = 1;
23774 			if (rack_do_dyn_mul >= 100)
23775 				rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
23776 		} else {
23777 			rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
23778 			rack->rc_gp_dyn_mul = 0;
23779 		}
23780 		rack->r_rr_config = 0;
23781 		rack->r_ctl.rc_no_push_at_mrtt = 0;
23782 		rack->rc_pace_fill_if_rttin_range = 0;
23783 		rack->rtt_limit_mul = 0;
23784 
23785 		if (rack_enable_hw_pacing)
23786 			rack->rack_hdw_pace_ena = 1;
23787 		else
23788 			rack->rack_hdw_pace_ena = 0;
23789 		if (rack_disable_prr)
23790 			rack->rack_no_prr = 1;
23791 		else
23792 			rack->rack_no_prr = 0;
23793 		if (rack_limits_scwnd)
23794 			rack->r_limit_scw  = 1;
23795 		else
23796 			rack->r_limit_scw  = 0;
23797 		rack_init_retransmit_value(rack, rack_rxt_controls);
23798 		err = 0;
23799 	}
23800 	return (err);
23801 }
23802 
23803 static int
rack_add_deferred_option(struct tcp_rack * rack,int sopt_name,uint64_t loptval)23804 rack_add_deferred_option(struct tcp_rack *rack, int sopt_name, uint64_t loptval)
23805 {
23806 	struct deferred_opt_list *dol;
23807 
23808 	dol = malloc(sizeof(struct deferred_opt_list),
23809 		     M_TCPDO, M_NOWAIT|M_ZERO);
23810 	if (dol == NULL) {
23811 		/*
23812 		 * No space yikes -- fail out..
23813 		 */
23814 		return (0);
23815 	}
23816 	dol->optname = sopt_name;
23817 	dol->optval = loptval;
23818 	TAILQ_INSERT_TAIL(&rack->r_ctl.opt_list, dol, next);
23819 	return (1);
23820 }
23821 
23822 static int
process_hybrid_pacing(struct tcp_rack * rack,struct tcp_hybrid_req * hybrid)23823 process_hybrid_pacing(struct tcp_rack *rack, struct tcp_hybrid_req *hybrid)
23824 {
23825 #ifdef TCP_REQUEST_TRK
23826 	struct tcp_sendfile_track *sft;
23827 	struct timeval tv;
23828 	tcp_seq seq;
23829 	int err;
23830 
23831 	microuptime(&tv);
23832 
23833 	/* Make sure no fixed rate is on */
23834 	rack->use_fixed_rate = 0;
23835 	rack->r_ctl.rc_fixed_pacing_rate_rec = 0;
23836 	rack->r_ctl.rc_fixed_pacing_rate_ca = 0;
23837 	rack->r_ctl.rc_fixed_pacing_rate_ss = 0;
23838 	/* Now allocate or find our entry that will have these settings */
23839 	sft = tcp_req_alloc_req_full(rack->rc_tp, &hybrid->req, tcp_tv_to_lusectick(&tv), 0);
23840 	if (sft == NULL) {
23841 		rack->rc_tp->tcp_hybrid_error++;
23842 		/* no space, where would it have gone? */
23843 		seq = rack->rc_tp->snd_una + rack->rc_tp->t_inpcb.inp_socket->so_snd.sb_ccc;
23844 		rack_log_hybrid(rack, seq, NULL, HYBRID_LOG_NO_ROOM, __LINE__, 0);
23845 		return (ENOSPC);
23846 	}
23847 	/* mask our internal flags */
23848 	hybrid->hybrid_flags &= TCP_HYBRID_PACING_USER_MASK;
23849 	/* The seq will be snd_una + everything in the buffer */
23850 	seq = sft->start_seq;
23851 	if ((hybrid->hybrid_flags & TCP_HYBRID_PACING_ENABLE) == 0) {
23852 		/* Disabling hybrid pacing */
23853 		if (rack->rc_hybrid_mode) {
23854 			rack_set_profile(rack, 0);
23855 			rack->rc_tp->tcp_hybrid_stop++;
23856 		}
23857 		rack_log_hybrid(rack, seq, sft, HYBRID_LOG_TURNED_OFF, __LINE__, 0);
23858 		return (0);
23859 	}
23860 	if (rack->dgp_on == 0) {
23861 		/*
23862 		 * If we have not yet turned DGP on, do so
23863 		 * now setting pure DGP mode, no buffer level
23864 		 * response.
23865 		 */
23866 		if ((err = rack_set_profile(rack, 1)) != 0){
23867 			/* Failed to turn pacing on */
23868 			rack->rc_tp->tcp_hybrid_error++;
23869 			rack_log_hybrid(rack, seq, sft, HYBRID_LOG_NO_PACING, __LINE__, 0);
23870 			return (err);
23871 		}
23872 	}
23873 	/*
23874 	 * Now we must switch to hybrid mode as well which also
23875 	 * means moving to regular pacing.
23876 	 */
23877 	if (rack->rc_hybrid_mode == 0) {
23878 		/* First time */
23879 		if (tcp_can_enable_pacing()) {
23880 			rack->r_ctl.pacing_method |= RACK_REG_PACING;
23881 			rack->rc_hybrid_mode = 1;
23882 		} else {
23883 			return (ENOSPC);
23884 		}
23885 		if (rack->r_ctl.pacing_method & RACK_DGP_PACING) {
23886 			/*
23887 			 * This should be true.
23888 			 */
23889 			tcp_dec_dgp_pacing_cnt();
23890 			rack->r_ctl.pacing_method &= ~RACK_DGP_PACING;
23891 		}
23892 	}
23893 	/* Now set in our flags */
23894 	sft->hybrid_flags = hybrid->hybrid_flags | TCP_HYBRID_PACING_WASSET;
23895 	if (hybrid->hybrid_flags & TCP_HYBRID_PACING_CSPR)
23896 		sft->cspr = hybrid->cspr;
23897 	else
23898 		sft->cspr = 0;
23899 	if (hybrid->hybrid_flags & TCP_HYBRID_PACING_H_MS)
23900 		sft->hint_maxseg = hybrid->hint_maxseg;
23901 	else
23902 		sft->hint_maxseg = 0;
23903 	rack->rc_tp->tcp_hybrid_start++;
23904 	rack_log_hybrid(rack, seq, sft, HYBRID_LOG_RULES_SET, __LINE__,0);
23905 	return (0);
23906 #else
23907 	return (ENOTSUP);
23908 #endif
23909 }
23910 
23911 static int
rack_stack_information(struct tcpcb * tp,struct stack_specific_info * si)23912 rack_stack_information(struct tcpcb *tp, struct stack_specific_info *si)
23913 {
23914 	/*
23915 	 * Gather rack specific information.
23916 	 */
23917 	struct tcp_rack *rack;
23918 
23919 	rack = (struct tcp_rack *)tp->t_fb_ptr;
23920 	/* We pulled a SSI info log out what was there */
23921 	policer_detection_log(rack, rack->rc_highly_buffered, 0, 0, 0, 20);
23922 	if (rack->policer_detect_on) {
23923 		si->policer_detection_enabled = 1;
23924 		if (rack->rc_policer_detected) {
23925 			si->policer_detected = 1;
23926 			si->policer_bucket_size = rack->r_ctl.policer_bucket_size;
23927 			si->policer_last_bw = rack->r_ctl.policer_bw;
23928 		} else {
23929 			si->policer_detected = 0;
23930 			si->policer_bucket_size = 0;
23931 			si->policer_last_bw = 0;
23932 		}
23933 		si->current_round = rack->r_ctl.current_round;
23934 		si->highly_buffered = rack->rc_highly_buffered;
23935 	}
23936 	si->bytes_transmitted = tp->t_sndbytes;
23937 	si->bytes_retransmitted = tp->t_snd_rxt_bytes;
23938 	return (0);
23939 }
23940 
23941 static int
rack_process_option(struct tcpcb * tp,struct tcp_rack * rack,int sopt_name,uint32_t optval,uint64_t loptval,struct tcp_hybrid_req * hybrid)23942 rack_process_option(struct tcpcb *tp, struct tcp_rack *rack, int sopt_name,
23943 		    uint32_t optval, uint64_t loptval, struct tcp_hybrid_req *hybrid)
23944 
23945 {
23946 	struct epoch_tracker et;
23947 	struct sockopt sopt;
23948 	struct cc_newreno_opts opt;
23949 	uint64_t val;
23950 	int error = 0;
23951 	uint16_t ca, ss;
23952 
23953 	switch (sopt_name) {
23954 	case TCP_RACK_SET_RXT_OPTIONS:
23955 		if ((optval >= 0) && (optval <= 2)) {
23956 			rack_init_retransmit_value(rack, optval);
23957 		} else {
23958 			/*
23959 			 * You must send in 0, 1 or 2 all else is
23960 			 * invalid.
23961 			 */
23962 			error = EINVAL;
23963 		}
23964 		break;
23965 	case TCP_RACK_DSACK_OPT:
23966 		RACK_OPTS_INC(tcp_rack_dsack_opt);
23967 		if (optval & 0x1) {
23968 			rack->rc_rack_tmr_std_based = 1;
23969 		} else {
23970 			rack->rc_rack_tmr_std_based = 0;
23971 		}
23972 		if (optval & 0x2) {
23973 			rack->rc_rack_use_dsack = 1;
23974 		} else {
23975 			rack->rc_rack_use_dsack = 0;
23976 		}
23977 		rack_log_dsack_event(rack, 5, __LINE__, 0, 0);
23978 		break;
23979 	case TCP_RACK_PACING_DIVISOR:
23980 		RACK_OPTS_INC(tcp_rack_pacing_divisor);
23981 		if (optval == 0) {
23982 			rack->r_ctl.pace_len_divisor = rack_default_pacing_divisor;
23983 		} else {
23984 			if (optval < RL_MIN_DIVISOR)
23985 				rack->r_ctl.pace_len_divisor = RL_MIN_DIVISOR;
23986 			else
23987 				rack->r_ctl.pace_len_divisor = optval;
23988 		}
23989 		break;
23990 	case TCP_RACK_HI_BETA:
23991 		RACK_OPTS_INC(tcp_rack_hi_beta);
23992 		if (optval > 0) {
23993 			rack->rack_hibeta = 1;
23994 			if ((optval >= 50) &&
23995 			    (optval <= 100)) {
23996 				/*
23997 				 * User wants to set a custom beta.
23998 				 */
23999 				rack->r_ctl.saved_hibeta = optval;
24000 				if (rack->rc_pacing_cc_set)
24001 					rack_undo_cc_pacing(rack);
24002 				rack->r_ctl.rc_saved_beta.beta = optval;
24003 			}
24004 			if (rack->rc_pacing_cc_set == 0)
24005 				rack_set_cc_pacing(rack);
24006 		} else {
24007 			rack->rack_hibeta = 0;
24008 			if (rack->rc_pacing_cc_set)
24009 				rack_undo_cc_pacing(rack);
24010 		}
24011 		break;
24012 	case TCP_RACK_PACING_BETA:
24013 		error = EINVAL;
24014 		break;
24015 	case TCP_RACK_TIMER_SLOP:
24016 		RACK_OPTS_INC(tcp_rack_timer_slop);
24017 		rack->r_ctl.timer_slop = optval;
24018 		if (rack->rc_tp->t_srtt) {
24019 			/*
24020 			 * If we have an SRTT lets update t_rxtcur
24021 			 * to have the new slop.
24022 			 */
24023 			RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
24024 					   rack_rto_min, rack_rto_max,
24025 					   rack->r_ctl.timer_slop);
24026 		}
24027 		break;
24028 	case TCP_RACK_PACING_BETA_ECN:
24029 		RACK_OPTS_INC(tcp_rack_beta_ecn);
24030 		if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0) {
24031 			/* This only works for newreno. */
24032 			error = EINVAL;
24033 			break;
24034 		}
24035 		if (rack->rc_pacing_cc_set) {
24036 			/*
24037 			 * Set them into the real CC module
24038 			 * whats in the rack pcb is the old values
24039 			 * to be used on restoral/
24040 			 */
24041 			sopt.sopt_dir = SOPT_SET;
24042 			opt.name = CC_NEWRENO_BETA_ECN;
24043 			opt.val = optval;
24044 			if (CC_ALGO(tp)->ctl_output != NULL)
24045 				error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
24046 			else
24047 				error = ENOENT;
24048 		} else {
24049 			/*
24050 			 * Not pacing yet so set it into our local
24051 			 * rack pcb storage.
24052 			 */
24053 			rack->r_ctl.rc_saved_beta.beta_ecn = optval;
24054 			rack->r_ctl.rc_saved_beta.newreno_flags = CC_NEWRENO_BETA_ECN_ENABLED;
24055 		}
24056 		break;
24057 	case TCP_DEFER_OPTIONS:
24058 		RACK_OPTS_INC(tcp_defer_opt);
24059 		if (optval) {
24060 			if (rack->gp_ready) {
24061 				/* Too late */
24062 				error = EINVAL;
24063 				break;
24064 			}
24065 			rack->defer_options = 1;
24066 		} else
24067 			rack->defer_options = 0;
24068 		break;
24069 	case TCP_RACK_MEASURE_CNT:
24070 		RACK_OPTS_INC(tcp_rack_measure_cnt);
24071 		if (optval && (optval <= 0xff)) {
24072 			rack->r_ctl.req_measurements = optval;
24073 		} else
24074 			error = EINVAL;
24075 		break;
24076 	case TCP_REC_ABC_VAL:
24077 		RACK_OPTS_INC(tcp_rec_abc_val);
24078 		if (optval > 0)
24079 			rack->r_use_labc_for_rec = 1;
24080 		else
24081 			rack->r_use_labc_for_rec = 0;
24082 		break;
24083 	case TCP_RACK_ABC_VAL:
24084 		RACK_OPTS_INC(tcp_rack_abc_val);
24085 		if ((optval > 0) && (optval < 255))
24086 			rack->rc_labc = optval;
24087 		else
24088 			error = EINVAL;
24089 		break;
24090 	case TCP_HDWR_UP_ONLY:
24091 		RACK_OPTS_INC(tcp_pacing_up_only);
24092 		if (optval)
24093 			rack->r_up_only = 1;
24094 		else
24095 			rack->r_up_only = 0;
24096 		break;
24097 	case TCP_FILLCW_RATE_CAP:		/*  URL:fillcw_cap */
24098 		RACK_OPTS_INC(tcp_fillcw_rate_cap);
24099 		rack->r_ctl.fillcw_cap = loptval;
24100 		break;
24101 	case TCP_PACING_RATE_CAP:
24102 		RACK_OPTS_INC(tcp_pacing_rate_cap);
24103 		if ((rack->dgp_on == 1) &&
24104 		    (rack->r_ctl.pacing_method & RACK_DGP_PACING)) {
24105 			/*
24106 			 * If we are doing DGP we need to switch
24107 			 * to using the pacing limit.
24108 			 */
24109 			if (tcp_can_enable_pacing() == 0) {
24110 				error = ENOSPC;
24111 				break;
24112 			}
24113 			/*
24114 			 * Now change up the flags and counts to be correct.
24115 			 */
24116 			rack->r_ctl.pacing_method |= RACK_REG_PACING;
24117 			tcp_dec_dgp_pacing_cnt();
24118 			rack->r_ctl.pacing_method &= ~RACK_DGP_PACING;
24119 		}
24120 		rack->r_ctl.bw_rate_cap = loptval;
24121 		break;
24122 	case TCP_HYBRID_PACING:
24123 		if (hybrid == NULL) {
24124 			error = EINVAL;
24125 			break;
24126 		}
24127 		if (rack->r_ctl.side_chan_dis_mask & HYBRID_DIS_MASK) {
24128 			error = EPERM;
24129 			break;
24130 		}
24131 		error = process_hybrid_pacing(rack, hybrid);
24132 		break;
24133 	case TCP_SIDECHAN_DIS:			/*  URL:scodm */
24134 		if (optval)
24135 			rack->r_ctl.side_chan_dis_mask = optval;
24136 		else
24137 			rack->r_ctl.side_chan_dis_mask = 0;
24138 		break;
24139 	case TCP_RACK_PROFILE:
24140 		RACK_OPTS_INC(tcp_profile);
24141 		error = rack_set_profile(rack, optval);
24142 		break;
24143 	case TCP_USE_CMP_ACKS:
24144 		RACK_OPTS_INC(tcp_use_cmp_acks);
24145 		if ((optval == 0) && (tp->t_flags2 & TF2_MBUF_ACKCMP)) {
24146 			/* You can't turn it off once its on! */
24147 			error = EINVAL;
24148 		} else if ((optval == 1) && (rack->r_use_cmp_ack == 0)) {
24149 			rack->r_use_cmp_ack = 1;
24150 			rack->r_mbuf_queue = 1;
24151 			tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
24152 		}
24153 		if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
24154 			tp->t_flags2 |= TF2_MBUF_ACKCMP;
24155 		break;
24156 	case TCP_SHARED_CWND_TIME_LIMIT:
24157 		RACK_OPTS_INC(tcp_lscwnd);
24158 		if (optval)
24159 			rack->r_limit_scw = 1;
24160 		else
24161 			rack->r_limit_scw = 0;
24162 		break;
24163 	case TCP_RACK_DGP_IN_REC:
24164 		error = EINVAL;
24165 		break;
24166 	case TCP_POLICER_DETECT:		/*  URL:pol_det */
24167 		RACK_OPTS_INC(tcp_pol_detect);
24168 		rack_translate_policer_detect(rack, optval);
24169 		break;
24170 	case TCP_POLICER_MSS:
24171 		RACK_OPTS_INC(tcp_pol_mss);
24172 		rack->r_ctl.policer_del_mss = (uint8_t)optval;
24173 		if (optval & 0x00000100) {
24174 			/*
24175 			 * Value is setup like so:
24176 			 * VVVV VVVV VVVV VVVV VVVV VVAI MMMM MMMM
24177 			 * Where MMMM MMMM is MSS setting
24178 			 * I (9th bit) is the Postive value that
24179 			 * says it is being set (if its 0 then the
24180 			 * upper bits 11 - 32 have no meaning.
24181 			 * This allows setting it off with
24182 			 * 0x000001MM.
24183 			 *
24184 			 * The 10th bit is used to turn on the
24185 			 * alternate median (not the expanded one).
24186 			 *
24187 			 */
24188 			rack->r_ctl.pol_bw_comp = (optval >> 10);
24189 		}
24190 		if (optval & 0x00000200) {
24191 			rack->r_ctl.policer_alt_median = 1;
24192 		} else {
24193 			rack->r_ctl.policer_alt_median = 0;
24194 		}
24195 		break;
24196  	case TCP_RACK_PACE_TO_FILL:
24197 		RACK_OPTS_INC(tcp_fillcw);
24198 		if (optval == 0)
24199 			rack->rc_pace_to_cwnd = 0;
24200 		else {
24201 			rack->rc_pace_to_cwnd = 1;
24202 		}
24203 		if ((optval >= rack_gp_rtt_maxmul) &&
24204 		    rack_gp_rtt_maxmul &&
24205 		    (optval < 0xf)) {
24206 			rack->rc_pace_fill_if_rttin_range = 1;
24207 			rack->rtt_limit_mul = optval;
24208 		} else {
24209 			rack->rc_pace_fill_if_rttin_range = 0;
24210 			rack->rtt_limit_mul = 0;
24211 		}
24212 		break;
24213 	case TCP_RACK_NO_PUSH_AT_MAX:
24214 		RACK_OPTS_INC(tcp_npush);
24215 		if (optval == 0)
24216 			rack->r_ctl.rc_no_push_at_mrtt = 0;
24217 		else if (optval < 0xff)
24218 			rack->r_ctl.rc_no_push_at_mrtt = optval;
24219 		else
24220 			error = EINVAL;
24221 		break;
24222 	case TCP_SHARED_CWND_ENABLE:
24223 		RACK_OPTS_INC(tcp_rack_scwnd);
24224 		if (optval == 0)
24225 			rack->rack_enable_scwnd = 0;
24226 		else
24227 			rack->rack_enable_scwnd = 1;
24228 		break;
24229 	case TCP_RACK_MBUF_QUEUE:
24230 		/* Now do we use the LRO mbuf-queue feature */
24231 		RACK_OPTS_INC(tcp_rack_mbufq);
24232 		if (optval || rack->r_use_cmp_ack)
24233 			rack->r_mbuf_queue = 1;
24234 		else
24235 			rack->r_mbuf_queue = 0;
24236 		if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
24237 			tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
24238 		else
24239 			tp->t_flags2 &= ~TF2_SUPPORTS_MBUFQ;
24240 		break;
24241 	case TCP_RACK_NONRXT_CFG_RATE:
24242 		RACK_OPTS_INC(tcp_rack_cfg_rate);
24243 		if (optval == 0)
24244 			rack->rack_rec_nonrxt_use_cr = 0;
24245 		else
24246 			rack->rack_rec_nonrxt_use_cr = 1;
24247 		break;
24248 	case TCP_NO_PRR:
24249 		RACK_OPTS_INC(tcp_rack_noprr);
24250 		if (optval == 0)
24251 			rack->rack_no_prr = 0;
24252 		else if (optval == 1)
24253 			rack->rack_no_prr = 1;
24254 		else if (optval == 2)
24255 			rack->no_prr_addback = 1;
24256 		else
24257 			error = EINVAL;
24258 		break;
24259 	case RACK_CSPR_IS_FCC:			/*  URL:csprisfcc */
24260 		if (optval > 0)
24261 			rack->cspr_is_fcc = 1;
24262 		else
24263 			rack->cspr_is_fcc = 0;
24264 		break;
24265 	case TCP_TIMELY_DYN_ADJ:
24266 		RACK_OPTS_INC(tcp_timely_dyn);
24267 		if (optval == 0)
24268 			rack->rc_gp_dyn_mul = 0;
24269 		else {
24270 			rack->rc_gp_dyn_mul = 1;
24271 			if (optval >= 100) {
24272 				/*
24273 				 * If the user sets something 100 or more
24274 				 * its the gp_ca value.
24275 				 */
24276 				rack->r_ctl.rack_per_of_gp_ca  = optval;
24277 			}
24278 		}
24279 		break;
24280 	case TCP_RACK_DO_DETECTION:
24281 		error = EINVAL;
24282 		break;
24283 	case TCP_RACK_TLP_USE:
24284 		if ((optval < TLP_USE_ID) || (optval > TLP_USE_TWO_TWO)) {
24285 			error = EINVAL;
24286 			break;
24287 		}
24288 		RACK_OPTS_INC(tcp_tlp_use);
24289 		rack->rack_tlp_threshold_use = optval;
24290 		break;
24291 	case TCP_RACK_TLP_REDUCE:
24292 		/* RACK TLP cwnd reduction (bool) */
24293 		RACK_OPTS_INC(tcp_rack_tlp_reduce);
24294 		rack->r_ctl.rc_tlp_cwnd_reduce = optval;
24295 		break;
24296 		/*  Pacing related ones */
24297 	case TCP_RACK_PACE_ALWAYS:
24298 		/*
24299 		 * zero is old rack method, 1 is new
24300 		 * method using a pacing rate.
24301 		 */
24302 		RACK_OPTS_INC(tcp_rack_pace_always);
24303 		if (rack->r_ctl.side_chan_dis_mask & CCSP_DIS_MASK) {
24304 			error = EPERM;
24305 			break;
24306 		}
24307 		if (optval > 0) {
24308 			if (rack->rc_always_pace) {
24309 				error = EALREADY;
24310 				break;
24311 			} else if (tcp_can_enable_pacing()) {
24312 				rack->r_ctl.pacing_method |= RACK_REG_PACING;
24313 				rack->rc_always_pace = 1;
24314 				if (rack->rack_hibeta)
24315 					rack_set_cc_pacing(rack);
24316 			}
24317 			else {
24318 				error = ENOSPC;
24319 				break;
24320 			}
24321 		} else {
24322 			if (rack->rc_always_pace == 1) {
24323 				rack_remove_pacing(rack);
24324 			}
24325 		}
24326 		if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
24327 			tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
24328 		else
24329 			tp->t_flags2 &= ~TF2_SUPPORTS_MBUFQ;
24330 		/* A rate may be set irate or other, if so set seg size */
24331 		rack_update_seg(rack);
24332 		break;
24333 	case TCP_BBR_RACK_INIT_RATE:
24334 		RACK_OPTS_INC(tcp_initial_rate);
24335 		val = optval;
24336 		/* Change from kbits per second to bytes per second */
24337 		val *= 1000;
24338 		val /= 8;
24339 		rack->r_ctl.init_rate = val;
24340 		if (rack->rc_always_pace)
24341 			rack_update_seg(rack);
24342 		break;
24343 	case TCP_BBR_IWINTSO:
24344 		error = EINVAL;
24345 		break;
24346 	case TCP_RACK_FORCE_MSEG:
24347 		RACK_OPTS_INC(tcp_rack_force_max_seg);
24348 		if (optval)
24349 			rack->rc_force_max_seg = 1;
24350 		else
24351 			rack->rc_force_max_seg = 0;
24352 		break;
24353 	case TCP_RACK_PACE_MIN_SEG:
24354 		RACK_OPTS_INC(tcp_rack_min_seg);
24355 		rack->r_ctl.rc_user_set_min_segs = (0x0000ffff & optval);
24356 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
24357 		break;
24358 	case TCP_RACK_PACE_MAX_SEG:
24359 		/* Max segments size in a pace in bytes */
24360 		RACK_OPTS_INC(tcp_rack_max_seg);
24361 		if ((rack->dgp_on == 1) &&
24362 		    (rack->r_ctl.pacing_method & RACK_DGP_PACING)) {
24363 			/*
24364 			 * If we set a max-seg and are doing DGP then
24365 			 * we now fall under the pacing limits not the
24366 			 * DGP ones.
24367 			 */
24368 			if (tcp_can_enable_pacing() == 0) {
24369 				error = ENOSPC;
24370 				break;
24371 			}
24372 			/*
24373 			 * Now change up the flags and counts to be correct.
24374 			 */
24375 			rack->r_ctl.pacing_method |= RACK_REG_PACING;
24376 			tcp_dec_dgp_pacing_cnt();
24377 			rack->r_ctl.pacing_method &= ~RACK_DGP_PACING;
24378 		}
24379 		if (optval <= MAX_USER_SET_SEG)
24380 			rack->rc_user_set_max_segs = optval;
24381 		else
24382 			rack->rc_user_set_max_segs = MAX_USER_SET_SEG;
24383 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
24384 		break;
24385 	case TCP_RACK_PACE_RATE_REC:
24386 		/* Set the fixed pacing rate in Bytes per second ca */
24387 		RACK_OPTS_INC(tcp_rack_pace_rate_rec);
24388 		if (rack->r_ctl.side_chan_dis_mask & CCSP_DIS_MASK) {
24389 			error = EPERM;
24390 			break;
24391 		}
24392 		if (rack->dgp_on) {
24393 			/*
24394 			 * We are already pacing another
24395 			 * way.
24396 			 */
24397 			error = EBUSY;
24398 			break;
24399 		}
24400 		rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
24401 		if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
24402 			rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
24403 		if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
24404 			rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
24405 		rack->use_fixed_rate = 1;
24406 		if (rack->rack_hibeta)
24407 			rack_set_cc_pacing(rack);
24408 		rack_log_pacing_delay_calc(rack,
24409 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
24410 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
24411 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
24412 					   __LINE__, NULL,0);
24413 		break;
24414 
24415 	case TCP_RACK_PACE_RATE_SS:
24416 		/* Set the fixed pacing rate in Bytes per second ca */
24417 		RACK_OPTS_INC(tcp_rack_pace_rate_ss);
24418 		if (rack->r_ctl.side_chan_dis_mask & CCSP_DIS_MASK) {
24419 			error = EPERM;
24420 			break;
24421 		}
24422 		if (rack->dgp_on) {
24423 			/*
24424 			 * We are already pacing another
24425 			 * way.
24426 			 */
24427 			error = EBUSY;
24428 			break;
24429 		}
24430 		rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
24431 		if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
24432 			rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
24433 		if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
24434 			rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
24435 		rack->use_fixed_rate = 1;
24436 		if (rack->rack_hibeta)
24437 			rack_set_cc_pacing(rack);
24438 		rack_log_pacing_delay_calc(rack,
24439 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
24440 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
24441 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
24442 					   __LINE__, NULL, 0);
24443 		break;
24444 
24445 	case TCP_RACK_PACE_RATE_CA:
24446 		/* Set the fixed pacing rate in Bytes per second ca */
24447 		RACK_OPTS_INC(tcp_rack_pace_rate_ca);
24448 		if (rack->r_ctl.side_chan_dis_mask & CCSP_DIS_MASK) {
24449 			error = EPERM;
24450 			break;
24451 		}
24452 		if (rack->dgp_on) {
24453 			/*
24454 			 * We are already pacing another
24455 			 * way.
24456 			 */
24457 			error = EBUSY;
24458 			break;
24459 		}
24460 		rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
24461 		if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
24462 			rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
24463 		if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
24464 			rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
24465 		rack->use_fixed_rate = 1;
24466 		if (rack->rack_hibeta)
24467 			rack_set_cc_pacing(rack);
24468 		rack_log_pacing_delay_calc(rack,
24469 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
24470 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
24471 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
24472 					   __LINE__, NULL, 0);
24473 		break;
24474 	case TCP_RACK_GP_INCREASE_REC:
24475 		RACK_OPTS_INC(tcp_gp_inc_rec);
24476 		rack->r_ctl.rack_per_of_gp_rec = optval;
24477 		rack_log_pacing_delay_calc(rack,
24478 					   rack->r_ctl.rack_per_of_gp_ss,
24479 					   rack->r_ctl.rack_per_of_gp_ca,
24480 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
24481 					   __LINE__, NULL, 0);
24482 		break;
24483 	case TCP_RACK_GP_INCREASE_CA:
24484 		RACK_OPTS_INC(tcp_gp_inc_ca);
24485 		ca = optval;
24486 		if (ca < 100) {
24487 			/*
24488 			 * We don't allow any reduction
24489 			 * over the GP b/w.
24490 			 */
24491 			error = EINVAL;
24492 			break;
24493 		}
24494 		rack->r_ctl.rack_per_of_gp_ca = ca;
24495 		rack_log_pacing_delay_calc(rack,
24496 					   rack->r_ctl.rack_per_of_gp_ss,
24497 					   rack->r_ctl.rack_per_of_gp_ca,
24498 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
24499 					   __LINE__, NULL, 0);
24500 		break;
24501 	case TCP_RACK_GP_INCREASE_SS:
24502 		RACK_OPTS_INC(tcp_gp_inc_ss);
24503 		ss = optval;
24504 		if (ss < 100) {
24505 			/*
24506 			 * We don't allow any reduction
24507 			 * over the GP b/w.
24508 			 */
24509 			error = EINVAL;
24510 			break;
24511 		}
24512 		rack->r_ctl.rack_per_of_gp_ss = ss;
24513 		rack_log_pacing_delay_calc(rack,
24514 					   rack->r_ctl.rack_per_of_gp_ss,
24515 					   rack->r_ctl.rack_per_of_gp_ca,
24516 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
24517 					   __LINE__, NULL, 0);
24518 		break;
24519 	case TCP_RACK_RR_CONF:
24520 		RACK_OPTS_INC(tcp_rack_rrr_no_conf_rate);
24521 		if (optval && optval <= 3)
24522 			rack->r_rr_config = optval;
24523 		else
24524 			rack->r_rr_config = 0;
24525 		break;
24526 	case TCP_PACING_DND:			/*  URL:dnd */
24527 		if (optval > 0)
24528 			rack->rc_pace_dnd = 1;
24529 		else
24530 			rack->rc_pace_dnd = 0;
24531 		break;
24532 	case TCP_HDWR_RATE_CAP:
24533 		RACK_OPTS_INC(tcp_hdwr_rate_cap);
24534 		if (optval) {
24535 			if (rack->r_rack_hw_rate_caps == 0)
24536 				rack->r_rack_hw_rate_caps = 1;
24537 			else
24538 				error = EALREADY;
24539 		} else {
24540 			rack->r_rack_hw_rate_caps = 0;
24541 		}
24542 		break;
24543 	case TCP_DGP_UPPER_BOUNDS:
24544 	{
24545 		uint8_t val;
24546 		val = optval & 0x0000ff;
24547 		rack->r_ctl.rack_per_upper_bound_ca = val;
24548 		val = (optval >> 16) & 0x0000ff;
24549 		rack->r_ctl.rack_per_upper_bound_ss = val;
24550 		break;
24551 	}
24552 	case TCP_SS_EEXIT:			/*  URL:eexit */
24553 		if (optval > 0) {
24554 			rack->r_ctl.gp_rnd_thresh =  optval & 0x0ff;
24555 			if (optval & 0x10000) {
24556 				rack->r_ctl.gate_to_fs = 1;
24557 			} else {
24558 				rack->r_ctl.gate_to_fs = 0;
24559 			}
24560 			if (optval & 0x20000) {
24561 				rack->r_ctl.use_gp_not_last = 1;
24562 			} else {
24563 				rack->r_ctl.use_gp_not_last = 0;
24564 			}
24565 			if (optval & 0xfffc0000) {
24566 				uint32_t v;
24567 
24568 				v = (optval >> 18) & 0x00003fff;
24569 				if (v >= 1000)
24570 					rack->r_ctl.gp_gain_req = v;
24571 			}
24572 		} else {
24573 			/* We do not do ss early exit at all */
24574 			rack->rc_initial_ss_comp = 1;
24575 			rack->r_ctl.gp_rnd_thresh = 0;
24576 		}
24577 		break;
24578 	case TCP_RACK_SPLIT_LIMIT:
24579 		RACK_OPTS_INC(tcp_split_limit);
24580 		rack->r_ctl.rc_split_limit = optval;
24581 		break;
24582 	case TCP_BBR_HDWR_PACE:
24583 		RACK_OPTS_INC(tcp_hdwr_pacing);
24584 		if (optval){
24585 			if (rack->rack_hdrw_pacing == 0) {
24586 				rack->rack_hdw_pace_ena = 1;
24587 				rack->rack_attempt_hdwr_pace = 0;
24588 			} else
24589 				error = EALREADY;
24590 		} else {
24591 			rack->rack_hdw_pace_ena = 0;
24592 #ifdef RATELIMIT
24593 			if (rack->r_ctl.crte != NULL) {
24594 				rack->rack_hdrw_pacing = 0;
24595 				rack->rack_attempt_hdwr_pace = 0;
24596 				tcp_rel_pacing_rate(rack->r_ctl.crte, tp);
24597 				rack->r_ctl.crte = NULL;
24598 			}
24599 #endif
24600 		}
24601 		break;
24602 		/*  End Pacing related ones */
24603 	case TCP_RACK_PRR_SENDALOT:
24604 		/* Allow PRR to send more than one seg */
24605 		RACK_OPTS_INC(tcp_rack_prr_sendalot);
24606 		rack->r_ctl.rc_prr_sendalot = optval;
24607 		break;
24608 	case TCP_RACK_MIN_TO:
24609 		/* Minimum time between rack t-o's in ms */
24610 		RACK_OPTS_INC(tcp_rack_min_to);
24611 		rack->r_ctl.rc_min_to = optval;
24612 		break;
24613 	case TCP_RACK_EARLY_SEG:
24614 		/* If early recovery max segments */
24615 		RACK_OPTS_INC(tcp_rack_early_seg);
24616 		rack->r_ctl.rc_early_recovery_segs = optval;
24617 		break;
24618 	case TCP_RACK_ENABLE_HYSTART:
24619 	{
24620 		if (optval) {
24621 			tp->t_ccv.flags |= CCF_HYSTART_ALLOWED;
24622 			if (rack_do_hystart > RACK_HYSTART_ON)
24623 				tp->t_ccv.flags |= CCF_HYSTART_CAN_SH_CWND;
24624 			if (rack_do_hystart > RACK_HYSTART_ON_W_SC)
24625 				tp->t_ccv.flags |= CCF_HYSTART_CONS_SSTH;
24626 		} else {
24627 			tp->t_ccv.flags &= ~(CCF_HYSTART_ALLOWED|CCF_HYSTART_CAN_SH_CWND|CCF_HYSTART_CONS_SSTH);
24628 		}
24629 	}
24630 	break;
24631 	case TCP_RACK_REORD_THRESH:
24632 		/* RACK reorder threshold (shift amount) */
24633 		RACK_OPTS_INC(tcp_rack_reord_thresh);
24634 		if ((optval > 0) && (optval < 31))
24635 			rack->r_ctl.rc_reorder_shift = optval;
24636 		else
24637 			error = EINVAL;
24638 		break;
24639 	case TCP_RACK_REORD_FADE:
24640 		/* Does reordering fade after ms time */
24641 		RACK_OPTS_INC(tcp_rack_reord_fade);
24642 		rack->r_ctl.rc_reorder_fade = optval;
24643 		break;
24644 	case TCP_RACK_TLP_THRESH:
24645 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
24646 		RACK_OPTS_INC(tcp_rack_tlp_thresh);
24647 		if (optval)
24648 			rack->r_ctl.rc_tlp_threshold = optval;
24649 		else
24650 			error = EINVAL;
24651 		break;
24652 	case TCP_BBR_USE_RACK_RR:
24653 		RACK_OPTS_INC(tcp_rack_rr);
24654 		if (optval)
24655 			rack->use_rack_rr = 1;
24656 		else
24657 			rack->use_rack_rr = 0;
24658 		break;
24659 	case TCP_RACK_PKT_DELAY:
24660 		/* RACK added ms i.e. rack-rtt + reord + N */
24661 		RACK_OPTS_INC(tcp_rack_pkt_delay);
24662 		rack->r_ctl.rc_pkt_delay = optval;
24663 		break;
24664 	case TCP_DELACK:
24665 		RACK_OPTS_INC(tcp_rack_delayed_ack);
24666 		if (optval == 0)
24667 			tp->t_delayed_ack = 0;
24668 		else
24669 			tp->t_delayed_ack = 1;
24670 		if (tp->t_flags & TF_DELACK) {
24671 			tp->t_flags &= ~TF_DELACK;
24672 			tp->t_flags |= TF_ACKNOW;
24673 			NET_EPOCH_ENTER(et);
24674 			rack_output(tp);
24675 			NET_EPOCH_EXIT(et);
24676 		}
24677 		break;
24678 
24679 	case TCP_BBR_RACK_RTT_USE:
24680 		RACK_OPTS_INC(tcp_rack_rtt_use);
24681 		if ((optval != USE_RTT_HIGH) &&
24682 		    (optval != USE_RTT_LOW) &&
24683 		    (optval != USE_RTT_AVG))
24684 			error = EINVAL;
24685 		else
24686 			rack->r_ctl.rc_rate_sample_method = optval;
24687 		break;
24688 	case TCP_HONOR_HPTS_MIN:
24689 		RACK_OPTS_INC(tcp_honor_hpts);
24690 		if (optval) {
24691 			rack->r_use_hpts_min = 1;
24692 			/*
24693 			 * Must be between 2 - 80% to be a reduction else
24694 			 * we keep the default (10%).
24695 			 */
24696 			if ((optval > 1) && (optval <= 80)) {
24697 				rack->r_ctl.max_reduction = optval;
24698 			}
24699 		} else
24700 			rack->r_use_hpts_min = 0;
24701 		break;
24702 	case TCP_REC_IS_DYN:			/*  URL:dynrec */
24703 		RACK_OPTS_INC(tcp_dyn_rec);
24704 		if (optval)
24705 			rack->rc_gp_no_rec_chg = 1;
24706 		else
24707 			rack->rc_gp_no_rec_chg = 0;
24708 		break;
24709 	case TCP_NO_TIMELY:
24710 		RACK_OPTS_INC(tcp_notimely);
24711 		if (optval) {
24712 			rack->rc_skip_timely = 1;
24713 			rack->r_ctl.rack_per_of_gp_rec = 90;
24714 			rack->r_ctl.rack_per_of_gp_ca = 100;
24715 			rack->r_ctl.rack_per_of_gp_ss = 250;
24716 		} else {
24717 			rack->rc_skip_timely = 0;
24718 		}
24719 		break;
24720 	case TCP_GP_USE_LTBW:
24721 		if (optval == 0) {
24722 			rack->use_lesser_lt_bw = 0;
24723 			rack->dis_lt_bw = 1;
24724 		} else if (optval == 1) {
24725 			rack->use_lesser_lt_bw = 1;
24726 			rack->dis_lt_bw = 0;
24727 		} else if (optval == 2) {
24728 			rack->use_lesser_lt_bw = 0;
24729 			rack->dis_lt_bw = 0;
24730 		}
24731 		break;
24732 	case TCP_DATA_AFTER_CLOSE:
24733 		RACK_OPTS_INC(tcp_data_after_close);
24734 		if (optval)
24735 			rack->rc_allow_data_af_clo = 1;
24736 		else
24737 			rack->rc_allow_data_af_clo = 0;
24738 		break;
24739 	default:
24740 		break;
24741 	}
24742 	tcp_log_socket_option(tp, sopt_name, optval, error);
24743 	return (error);
24744 }
24745 
24746 static void
rack_inherit(struct tcpcb * tp,struct inpcb * parent)24747 rack_inherit(struct tcpcb *tp, struct inpcb *parent)
24748 {
24749 	/*
24750 	 * A new connection has been created (tp) and
24751 	 * the parent is the inpcb given. We want to
24752 	 * apply a read-lock to the parent (we are already
24753 	 * holding a write lock on the tp) and copy anything
24754 	 * out of the rack specific data as long as its tfb is
24755 	 * the same as ours i.e. we are the same stack. Otherwise
24756 	 * we just return.
24757 	 */
24758 	struct tcpcb *par;
24759 	struct tcp_rack *dest, *src;
24760 	int cnt = 0;
24761 
24762 	par = intotcpcb(parent);
24763 	if (par->t_fb != tp->t_fb) {
24764 		/* Not the same stack */
24765 		tcp_log_socket_option(tp, 0, 0, 1);
24766 		return;
24767 	}
24768 	/* Ok if we reach here lets setup the two rack pointers */
24769 	dest = (struct tcp_rack *)tp->t_fb_ptr;
24770 	src = (struct tcp_rack *)par->t_fb_ptr;
24771 	if ((src == NULL) || (dest == NULL)) {
24772 		/* Huh? */
24773 		tcp_log_socket_option(tp, 0, 0, 2);
24774 		return;
24775 	}
24776 	/* Now copy out anything we wish to inherit i.e. things in socket-options */
24777 	/* TCP_RACK_PROFILE we can't know but we can set DGP if its on */
24778 	if ((src->dgp_on) && (dest->dgp_on == 0)) {
24779 		/* Profile 1 had to be set via sock opt */
24780 		rack_set_dgp(dest);
24781 		cnt++;
24782 	}
24783 	/* TCP_RACK_SET_RXT_OPTIONS */
24784 	if (dest->full_size_rxt != src->full_size_rxt) {
24785 		dest->full_size_rxt = src->full_size_rxt;
24786 		cnt++;
24787 	}
24788 	if (dest->shape_rxt_to_pacing_min  != src->shape_rxt_to_pacing_min) {
24789 		dest->shape_rxt_to_pacing_min = src->shape_rxt_to_pacing_min;
24790 		cnt++;
24791 	}
24792 	/* TCP_RACK_DSACK_OPT */
24793 	if (dest->rc_rack_tmr_std_based != src->rc_rack_tmr_std_based) {
24794 		dest->rc_rack_tmr_std_based = src->rc_rack_tmr_std_based;
24795 		cnt++;
24796 	}
24797 	if (dest->rc_rack_use_dsack != src->rc_rack_use_dsack) {
24798 		dest->rc_rack_use_dsack = src->rc_rack_use_dsack;
24799 		cnt++;
24800 	}
24801 	/* TCP_RACK_PACING_DIVISOR */
24802 	if (dest->r_ctl.pace_len_divisor != src->r_ctl.pace_len_divisor) {
24803 		dest->r_ctl.pace_len_divisor = src->r_ctl.pace_len_divisor;
24804 		cnt++;
24805 	}
24806 	/* TCP_RACK_HI_BETA */
24807 	if (src->rack_hibeta != dest->rack_hibeta) {
24808 		cnt++;
24809 		if (src->rack_hibeta) {
24810 			dest->r_ctl.rc_saved_beta.beta = src->r_ctl.rc_saved_beta.beta;
24811 			dest->rack_hibeta = 1;
24812 		} else {
24813 			dest->rack_hibeta = 0;
24814 		}
24815 	}
24816 	/* TCP_RACK_TIMER_SLOP */
24817 	if (dest->r_ctl.timer_slop != src->r_ctl.timer_slop) {
24818 		dest->r_ctl.timer_slop = src->r_ctl.timer_slop;
24819 		cnt++;
24820 	}
24821 	/* TCP_RACK_PACING_BETA_ECN */
24822 	if (dest->r_ctl.rc_saved_beta.beta_ecn != src->r_ctl.rc_saved_beta.beta_ecn) {
24823 		dest->r_ctl.rc_saved_beta.beta_ecn = src->r_ctl.rc_saved_beta.beta_ecn;
24824 		cnt++;
24825 	}
24826 	if (dest->r_ctl.rc_saved_beta.newreno_flags != src->r_ctl.rc_saved_beta.newreno_flags) {
24827 		dest->r_ctl.rc_saved_beta.newreno_flags = src->r_ctl.rc_saved_beta.newreno_flags;
24828 		cnt++;
24829 	}
24830 	/* We do not do TCP_DEFER_OPTIONS */
24831 	/* TCP_RACK_MEASURE_CNT */
24832 	if (dest->r_ctl.req_measurements != src->r_ctl.req_measurements) {
24833 		dest->r_ctl.req_measurements = src->r_ctl.req_measurements;
24834 		cnt++;
24835 	}
24836 	/* TCP_HDWR_UP_ONLY */
24837 	if (dest->r_up_only != src->r_up_only) {
24838 		dest->r_up_only = src->r_up_only;
24839 		cnt++;
24840 	}
24841 	/* TCP_FILLCW_RATE_CAP */
24842 	if (dest->r_ctl.fillcw_cap != src->r_ctl.fillcw_cap) {
24843 		dest->r_ctl.fillcw_cap = src->r_ctl.fillcw_cap;
24844 		cnt++;
24845 	}
24846 	/* TCP_PACING_RATE_CAP */
24847 	if (dest->r_ctl.bw_rate_cap != src->r_ctl.bw_rate_cap) {
24848 		dest->r_ctl.bw_rate_cap = src->r_ctl.bw_rate_cap;
24849 		cnt++;
24850 	}
24851 	/* A listener can't set TCP_HYBRID_PACING */
24852 	/* TCP_SIDECHAN_DIS */
24853 	if (dest->r_ctl.side_chan_dis_mask != src->r_ctl.side_chan_dis_mask) {
24854 		dest->r_ctl.side_chan_dis_mask = src->r_ctl.side_chan_dis_mask;
24855 		cnt++;
24856 	}
24857 	/* TCP_SHARED_CWND_TIME_LIMIT */
24858 	if (dest->r_limit_scw != src->r_limit_scw) {
24859 		dest->r_limit_scw = src->r_limit_scw;
24860 		cnt++;
24861 	}
24862 	/* TCP_POLICER_DETECT */
24863 	if (dest->r_ctl.policer_rxt_threshold != src->r_ctl.policer_rxt_threshold) {
24864 		dest->r_ctl.policer_rxt_threshold = src->r_ctl.policer_rxt_threshold;
24865 		cnt++;
24866 	}
24867 	if (dest->r_ctl.policer_avg_threshold != src->r_ctl.policer_avg_threshold) {
24868 		dest->r_ctl.policer_avg_threshold = src->r_ctl.policer_avg_threshold;
24869 		cnt++;
24870 	}
24871 	if (dest->r_ctl.policer_med_threshold != src->r_ctl.policer_med_threshold) {
24872 		dest->r_ctl.policer_med_threshold = src->r_ctl.policer_med_threshold;
24873 		cnt++;
24874 	}
24875 	if (dest->policer_detect_on != src->policer_detect_on) {
24876 		dest->policer_detect_on = src->policer_detect_on;
24877 		cnt++;
24878 	}
24879 
24880 	if (dest->r_ctl.saved_policer_val != src->r_ctl.saved_policer_val) {
24881 		dest->r_ctl.saved_policer_val = src->r_ctl.saved_policer_val;
24882 		cnt++;
24883 	}
24884 	/* TCP_POLICER_MSS */
24885 	if (dest->r_ctl.policer_del_mss != src->r_ctl.policer_del_mss) {
24886 		dest->r_ctl.policer_del_mss = src->r_ctl.policer_del_mss;
24887 		cnt++;
24888 	}
24889 
24890 	if (dest->r_ctl.pol_bw_comp != src->r_ctl.pol_bw_comp) {
24891 		dest->r_ctl.pol_bw_comp = src->r_ctl.pol_bw_comp;
24892 		cnt++;
24893 	}
24894 
24895 	if (dest->r_ctl.policer_alt_median != src->r_ctl.policer_alt_median) {
24896 		dest->r_ctl.policer_alt_median = src->r_ctl.policer_alt_median;
24897 		cnt++;
24898 	}
24899 	/* TCP_RACK_PACE_TO_FILL */
24900 	if (dest->rc_pace_to_cwnd != src->rc_pace_to_cwnd) {
24901 		dest->rc_pace_to_cwnd = src->rc_pace_to_cwnd;
24902 		cnt++;
24903 	}
24904 	if (dest->rc_pace_fill_if_rttin_range != src->rc_pace_fill_if_rttin_range) {
24905 		dest->rc_pace_fill_if_rttin_range = src->rc_pace_fill_if_rttin_range;
24906 		cnt++;
24907 	}
24908 	if (dest->rtt_limit_mul != src->rtt_limit_mul) {
24909 		dest->rtt_limit_mul = src->rtt_limit_mul;
24910 		cnt++;
24911 	}
24912 	/* TCP_RACK_NO_PUSH_AT_MAX */
24913 	if (dest->r_ctl.rc_no_push_at_mrtt != src->r_ctl.rc_no_push_at_mrtt) {
24914 		dest->r_ctl.rc_no_push_at_mrtt = src->r_ctl.rc_no_push_at_mrtt;
24915 		cnt++;
24916 	}
24917 	/* TCP_SHARED_CWND_ENABLE */
24918 	if (dest->rack_enable_scwnd != src->rack_enable_scwnd) {
24919 		dest->rack_enable_scwnd = src->rack_enable_scwnd;
24920 		cnt++;
24921 	}
24922 	/* TCP_USE_CMP_ACKS */
24923 	if (dest->r_use_cmp_ack != src->r_use_cmp_ack) {
24924 		dest->r_use_cmp_ack = src->r_use_cmp_ack;
24925 		cnt++;
24926 	}
24927 
24928 	if (dest->r_mbuf_queue != src->r_mbuf_queue) {
24929 		dest->r_mbuf_queue = src->r_mbuf_queue;
24930 		cnt++;
24931 	}
24932 	/* TCP_RACK_MBUF_QUEUE */
24933 	if (dest->r_mbuf_queue != src->r_mbuf_queue) {
24934 		dest->r_mbuf_queue = src->r_mbuf_queue;
24935 		cnt++;
24936 	}
24937 	if  (dest->r_mbuf_queue || dest->rc_always_pace || dest->r_use_cmp_ack) {
24938 		tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
24939 	} else {
24940 		tp->t_flags2 &= ~TF2_SUPPORTS_MBUFQ;
24941 	}
24942 	if (dest->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state)) {
24943 		tp->t_flags2 |= TF2_MBUF_ACKCMP;
24944 	}
24945 	/* TCP_RACK_NONRXT_CFG_RATE */
24946 	if (dest->rack_rec_nonrxt_use_cr != src->rack_rec_nonrxt_use_cr) {
24947 		dest->rack_rec_nonrxt_use_cr = src->rack_rec_nonrxt_use_cr;
24948 		cnt++;
24949 	}
24950 	/* TCP_NO_PRR */
24951 	if (dest->rack_no_prr != src->rack_no_prr) {
24952 		dest->rack_no_prr = src->rack_no_prr;
24953 		cnt++;
24954 	}
24955 	if (dest->no_prr_addback != src->no_prr_addback) {
24956 		dest->no_prr_addback = src->no_prr_addback;
24957 		cnt++;
24958 	}
24959 	/* RACK_CSPR_IS_FCC */
24960 	if (dest->cspr_is_fcc != src->cspr_is_fcc) {
24961 		dest->cspr_is_fcc = src->cspr_is_fcc;
24962 		cnt++;
24963 	}
24964 	/* TCP_TIMELY_DYN_ADJ */
24965 	if (dest->rc_gp_dyn_mul != src->rc_gp_dyn_mul) {
24966 		dest->rc_gp_dyn_mul = src->rc_gp_dyn_mul;
24967 		cnt++;
24968 	}
24969 	if (dest->r_ctl.rack_per_of_gp_ca != src->r_ctl.rack_per_of_gp_ca) {
24970 		dest->r_ctl.rack_per_of_gp_ca = src->r_ctl.rack_per_of_gp_ca;
24971 		cnt++;
24972 	}
24973 	/* TCP_RACK_TLP_USE */
24974 	if (dest->rack_tlp_threshold_use != src->rack_tlp_threshold_use) {
24975 		dest->rack_tlp_threshold_use = src->rack_tlp_threshold_use;
24976 		cnt++;
24977 	}
24978 	/* we don't allow inheritence of TCP_RACK_PACE_ALWAYS */
24979 	/* TCP_BBR_RACK_INIT_RATE */
24980 	if (dest->r_ctl.init_rate != src->r_ctl.init_rate) {
24981 		dest->r_ctl.init_rate = src->r_ctl.init_rate;
24982 		cnt++;
24983 	}
24984 	/* TCP_RACK_FORCE_MSEG */
24985 	if (dest->rc_force_max_seg != src->rc_force_max_seg) {
24986 		dest->rc_force_max_seg = src->rc_force_max_seg;
24987 		cnt++;
24988 	}
24989 	/* TCP_RACK_PACE_MIN_SEG */
24990 	if (dest->r_ctl.rc_user_set_min_segs != src->r_ctl.rc_user_set_min_segs) {
24991 		dest->r_ctl.rc_user_set_min_segs = src->r_ctl.rc_user_set_min_segs;
24992 		cnt++;
24993 	}
24994 	/* we don't allow TCP_RACK_PACE_MAX_SEG */
24995 	/* TCP_RACK_PACE_RATE_REC, TCP_RACK_PACE_RATE_SS,  TCP_RACK_PACE_RATE_CA */
24996 	if (dest->r_ctl.rc_fixed_pacing_rate_ca != src->r_ctl.rc_fixed_pacing_rate_ca) {
24997 		dest->r_ctl.rc_fixed_pacing_rate_ca = src->r_ctl.rc_fixed_pacing_rate_ca;
24998 		cnt++;
24999 	}
25000 	if (dest->r_ctl.rc_fixed_pacing_rate_ss != src->r_ctl.rc_fixed_pacing_rate_ss) {
25001 		dest->r_ctl.rc_fixed_pacing_rate_ss = src->r_ctl.rc_fixed_pacing_rate_ss;
25002 		cnt++;
25003 	}
25004 	if (dest->r_ctl.rc_fixed_pacing_rate_rec != src->r_ctl.rc_fixed_pacing_rate_rec) {
25005 		dest->r_ctl.rc_fixed_pacing_rate_rec = src->r_ctl.rc_fixed_pacing_rate_rec;
25006 		cnt++;
25007 	}
25008 	/* TCP_RACK_GP_INCREASE_REC, TCP_RACK_GP_INCREASE_CA, TCP_RACK_GP_INCREASE_SS */
25009 	if (dest->r_ctl.rack_per_of_gp_rec != src->r_ctl.rack_per_of_gp_rec) {
25010 		dest->r_ctl.rack_per_of_gp_rec = src->r_ctl.rack_per_of_gp_rec;
25011 		cnt++;
25012 	}
25013 	if (dest->r_ctl.rack_per_of_gp_ca != src->r_ctl.rack_per_of_gp_ca) {
25014 		dest->r_ctl.rack_per_of_gp_ca = src->r_ctl.rack_per_of_gp_ca;
25015 		cnt++;
25016 	}
25017 
25018 	if (dest->r_ctl.rack_per_of_gp_ss != src->r_ctl.rack_per_of_gp_ss) {
25019 		dest->r_ctl.rack_per_of_gp_ss = src->r_ctl.rack_per_of_gp_ss;
25020 		cnt++;
25021 	}
25022 	/* TCP_RACK_RR_CONF */
25023 	if (dest->r_rr_config != src->r_rr_config) {
25024 		dest->r_rr_config = src->r_rr_config;
25025 		cnt++;
25026 	}
25027 	/* TCP_PACING_DND */
25028 	if (dest->rc_pace_dnd != src->rc_pace_dnd) {
25029 		dest->rc_pace_dnd = src->rc_pace_dnd;
25030 		cnt++;
25031 	}
25032 	/* TCP_HDWR_RATE_CAP */
25033 	if (dest->r_rack_hw_rate_caps != src->r_rack_hw_rate_caps) {
25034 		dest->r_rack_hw_rate_caps = src->r_rack_hw_rate_caps;
25035 		cnt++;
25036 	}
25037 	/* TCP_DGP_UPPER_BOUNDS */
25038 	if (dest->r_ctl.rack_per_upper_bound_ca != src->r_ctl.rack_per_upper_bound_ca) {
25039 		dest->r_ctl.rack_per_upper_bound_ca = src->r_ctl.rack_per_upper_bound_ca;
25040 		cnt++;
25041 	}
25042 	if (dest->r_ctl.rack_per_upper_bound_ss != src->r_ctl.rack_per_upper_bound_ss) {
25043 		dest->r_ctl.rack_per_upper_bound_ss = src->r_ctl.rack_per_upper_bound_ss;
25044 		cnt++;
25045 	}
25046 	/* TCP_SS_EEXIT */
25047 	if (dest->r_ctl.gp_rnd_thresh != src->r_ctl.gp_rnd_thresh) {
25048 		dest->r_ctl.gp_rnd_thresh = src->r_ctl.gp_rnd_thresh;
25049 		cnt++;
25050 	}
25051 	if (dest->r_ctl.gate_to_fs != src->r_ctl.gate_to_fs) {
25052 		dest->r_ctl.gate_to_fs = src->r_ctl.gate_to_fs;
25053 		cnt++;
25054 	}
25055 	if (dest->r_ctl.use_gp_not_last != src->r_ctl.use_gp_not_last) {
25056 		dest->r_ctl.use_gp_not_last = src->r_ctl.use_gp_not_last;
25057 		cnt++;
25058 	}
25059 	if (dest->r_ctl.gp_gain_req != src->r_ctl.gp_gain_req) {
25060 		dest->r_ctl.gp_gain_req = src->r_ctl.gp_gain_req;
25061 		cnt++;
25062 	}
25063 	/* TCP_BBR_HDWR_PACE */
25064 	if (dest->rack_hdw_pace_ena != src->rack_hdw_pace_ena) {
25065 		dest->rack_hdw_pace_ena = src->rack_hdw_pace_ena;
25066 		cnt++;
25067 	}
25068 	if (dest->rack_attempt_hdwr_pace != src->rack_attempt_hdwr_pace) {
25069 		dest->rack_attempt_hdwr_pace = src->rack_attempt_hdwr_pace;
25070 		cnt++;
25071 	}
25072 	/* TCP_RACK_PRR_SENDALOT */
25073 	if (dest->r_ctl.rc_prr_sendalot != src->r_ctl.rc_prr_sendalot) {
25074 		dest->r_ctl.rc_prr_sendalot = src->r_ctl.rc_prr_sendalot;
25075 		cnt++;
25076 	}
25077 	/* TCP_RACK_MIN_TO */
25078 	if (dest->r_ctl.rc_min_to != src->r_ctl.rc_min_to) {
25079 		dest->r_ctl.rc_min_to = src->r_ctl.rc_min_to;
25080 		cnt++;
25081 	}
25082 	/* TCP_RACK_EARLY_SEG */
25083 	if (dest->r_ctl.rc_early_recovery_segs != src->r_ctl.rc_early_recovery_segs) {
25084 		dest->r_ctl.rc_early_recovery_segs = src->r_ctl.rc_early_recovery_segs;
25085 		cnt++;
25086 	}
25087 	/* TCP_RACK_ENABLE_HYSTART */
25088 	if (par->t_ccv.flags != tp->t_ccv.flags) {
25089 		cnt++;
25090 		if (par->t_ccv.flags & CCF_HYSTART_ALLOWED) {
25091 			tp->t_ccv.flags |= CCF_HYSTART_ALLOWED;
25092 			if (rack_do_hystart > RACK_HYSTART_ON)
25093 				tp->t_ccv.flags |= CCF_HYSTART_CAN_SH_CWND;
25094 			if (rack_do_hystart > RACK_HYSTART_ON_W_SC)
25095 				tp->t_ccv.flags |= CCF_HYSTART_CONS_SSTH;
25096 		} else {
25097 			tp->t_ccv.flags &= ~(CCF_HYSTART_ALLOWED|CCF_HYSTART_CAN_SH_CWND|CCF_HYSTART_CONS_SSTH);
25098 		}
25099 	}
25100 	/* TCP_RACK_REORD_THRESH */
25101 	if (dest->r_ctl.rc_reorder_shift != src->r_ctl.rc_reorder_shift) {
25102 		dest->r_ctl.rc_reorder_shift = src->r_ctl.rc_reorder_shift;
25103 		cnt++;
25104 	}
25105 	/* TCP_RACK_REORD_FADE */
25106 	if (dest->r_ctl.rc_reorder_fade != src->r_ctl.rc_reorder_fade) {
25107 		dest->r_ctl.rc_reorder_fade = src->r_ctl.rc_reorder_fade;
25108 		cnt++;
25109 	}
25110 	/* TCP_RACK_TLP_THRESH */
25111 	if (dest->r_ctl.rc_tlp_threshold != src->r_ctl.rc_tlp_threshold) {
25112 		dest->r_ctl.rc_tlp_threshold = src->r_ctl.rc_tlp_threshold;
25113 		cnt++;
25114 	}
25115 	/* TCP_BBR_USE_RACK_RR */
25116 	if (dest->use_rack_rr != src->use_rack_rr) {
25117 		dest->use_rack_rr = src->use_rack_rr;
25118 		cnt++;
25119 	}
25120 	/* TCP_RACK_PKT_DELAY */
25121 	if (dest->r_ctl.rc_pkt_delay != src->r_ctl.rc_pkt_delay) {
25122 		dest->r_ctl.rc_pkt_delay = src->r_ctl.rc_pkt_delay;
25123 		cnt++;
25124 	}
25125 	/* TCP_DELACK will get copied via the main code if applicable */
25126 	/* TCP_BBR_RACK_RTT_USE */
25127 	if (dest->r_ctl.rc_rate_sample_method != src->r_ctl.rc_rate_sample_method) {
25128 		dest->r_ctl.rc_rate_sample_method = src->r_ctl.rc_rate_sample_method;
25129 		cnt++;
25130 	}
25131 	/* TCP_HONOR_HPTS_MIN */
25132 	if (dest->r_use_hpts_min != src->r_use_hpts_min) {
25133 		dest->r_use_hpts_min = src->r_use_hpts_min;
25134 		cnt++;
25135 	}
25136 	if (dest->r_ctl.max_reduction != src->r_ctl.max_reduction) {
25137 		dest->r_ctl.max_reduction = src->r_ctl.max_reduction;
25138 		cnt++;
25139 	}
25140 	/* TCP_REC_IS_DYN */
25141 	if (dest->rc_gp_no_rec_chg != src->rc_gp_no_rec_chg) {
25142 		dest->rc_gp_no_rec_chg = src->rc_gp_no_rec_chg;
25143 		cnt++;
25144 	}
25145 	if (dest->rc_skip_timely != src->rc_skip_timely) {
25146 		dest->rc_skip_timely = src->rc_skip_timely;
25147 		cnt++;
25148 	}
25149 	/* TCP_DATA_AFTER_CLOSE */
25150 	if (dest->rc_allow_data_af_clo != src->rc_allow_data_af_clo) {
25151 		dest->rc_allow_data_af_clo = src->rc_allow_data_af_clo;
25152 		cnt++;
25153 	}
25154 	/* TCP_GP_USE_LTBW */
25155 	if (src->use_lesser_lt_bw != dest->use_lesser_lt_bw) {
25156 		dest->use_lesser_lt_bw = src->use_lesser_lt_bw;
25157 		cnt++;
25158 	}
25159 	if (dest->dis_lt_bw != src->dis_lt_bw) {
25160 		dest->dis_lt_bw = src->dis_lt_bw;
25161 		cnt++;
25162 	}
25163 	tcp_log_socket_option(tp, 0, cnt, 0);
25164 }
25165 
25166 
25167 static void
rack_apply_deferred_options(struct tcp_rack * rack)25168 rack_apply_deferred_options(struct tcp_rack *rack)
25169 {
25170 	struct deferred_opt_list *dol, *sdol;
25171 	uint32_t s_optval;
25172 
25173 	TAILQ_FOREACH_SAFE(dol, &rack->r_ctl.opt_list, next, sdol) {
25174 		TAILQ_REMOVE(&rack->r_ctl.opt_list, dol, next);
25175 		/* Disadvantage of deferal is you loose the error return */
25176 		s_optval = (uint32_t)dol->optval;
25177 		(void)rack_process_option(rack->rc_tp, rack, dol->optname, s_optval, dol->optval, NULL);
25178 		free(dol, M_TCPDO);
25179 	}
25180 }
25181 
25182 static void
rack_hw_tls_change(struct tcpcb * tp,int chg)25183 rack_hw_tls_change(struct tcpcb *tp, int chg)
25184 {
25185 	/* Update HW tls state */
25186 	struct tcp_rack *rack;
25187 
25188 	rack = (struct tcp_rack *)tp->t_fb_ptr;
25189 	if (chg)
25190 		rack->r_ctl.fsb.hw_tls = 1;
25191 	else
25192 		rack->r_ctl.fsb.hw_tls = 0;
25193 }
25194 
25195 static int
rack_pru_options(struct tcpcb * tp,int flags)25196 rack_pru_options(struct tcpcb *tp, int flags)
25197 {
25198 	if (flags & PRUS_OOB)
25199 		return (EOPNOTSUPP);
25200 	return (0);
25201 }
25202 
25203 static bool
rack_wake_check(struct tcpcb * tp)25204 rack_wake_check(struct tcpcb *tp)
25205 {
25206 	struct tcp_rack *rack;
25207 	struct timeval tv;
25208 	uint32_t cts;
25209 
25210 	rack = (struct tcp_rack *)tp->t_fb_ptr;
25211 	if (rack->r_ctl.rc_hpts_flags) {
25212 		cts = tcp_get_usecs(&tv);
25213 		if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == PACE_PKT_OUTPUT){
25214 			/*
25215 			 * Pacing timer is up, check if we are ready.
25216 			 */
25217 			if (TSTMP_GEQ(cts, rack->r_ctl.rc_last_output_to))
25218 				return (true);
25219 		} else if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) != 0) {
25220 			/*
25221 			 * A timer is up, check if we are ready.
25222 			 */
25223 			if (TSTMP_GEQ(cts, rack->r_ctl.rc_timer_exp))
25224 				return (true);
25225 		}
25226 	}
25227 	return (false);
25228 }
25229 
25230 static struct tcp_function_block __tcp_rack = {
25231 	.tfb_tcp_block_name = __XSTRING(STACKNAME),
25232 	.tfb_tcp_output = rack_output,
25233 	.tfb_do_queued_segments = ctf_do_queued_segments,
25234 	.tfb_do_segment_nounlock = rack_do_segment_nounlock,
25235 	.tfb_tcp_do_segment = rack_do_segment,
25236 	.tfb_tcp_ctloutput = rack_ctloutput,
25237 	.tfb_tcp_fb_init = rack_init,
25238 	.tfb_tcp_fb_fini = rack_fini,
25239 	.tfb_tcp_timer_stop_all = rack_stopall,
25240 	.tfb_tcp_rexmit_tmr = rack_remxt_tmr,
25241 	.tfb_tcp_handoff_ok = rack_handoff_ok,
25242 	.tfb_tcp_mtu_chg = rack_mtu_change,
25243 	.tfb_pru_options = rack_pru_options,
25244 	.tfb_hwtls_change = rack_hw_tls_change,
25245 	.tfb_chg_query = rack_chg_query,
25246 	.tfb_switch_failed = rack_switch_failed,
25247 	.tfb_early_wake_check = rack_wake_check,
25248 	.tfb_compute_pipe = rack_compute_pipe,
25249 	.tfb_stack_info = rack_stack_information,
25250 	.tfb_inherit = rack_inherit,
25251 	.tfb_flags = TCP_FUNC_OUTPUT_CANDROP,
25252 
25253 };
25254 
25255 /*
25256  * rack_ctloutput() must drop the inpcb lock before performing copyin on
25257  * socket option arguments.  When it re-acquires the lock after the copy, it
25258  * has to revalidate that the connection is still valid for the socket
25259  * option.
25260  */
25261 static int
rack_set_sockopt(struct tcpcb * tp,struct sockopt * sopt)25262 rack_set_sockopt(struct tcpcb *tp, struct sockopt *sopt)
25263 {
25264 	struct inpcb *inp = tptoinpcb(tp);
25265 #ifdef INET
25266 	struct ip *ip;
25267 #endif
25268 	struct tcp_rack *rack;
25269 	struct tcp_hybrid_req hybrid;
25270 	uint64_t loptval;
25271 	int32_t error = 0, optval;
25272 
25273 	rack = (struct tcp_rack *)tp->t_fb_ptr;
25274 	if (rack == NULL) {
25275 		INP_WUNLOCK(inp);
25276 		return (EINVAL);
25277 	}
25278 #ifdef INET
25279 	ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
25280 #endif
25281 
25282 	switch (sopt->sopt_level) {
25283 #ifdef INET6
25284 	case IPPROTO_IPV6:
25285 		MPASS(inp->inp_vflag & INP_IPV6PROTO);
25286 		switch (sopt->sopt_name) {
25287 		case IPV6_USE_MIN_MTU:
25288 			tcp6_use_min_mtu(tp);
25289 			break;
25290 		}
25291 		INP_WUNLOCK(inp);
25292 		return (0);
25293 #endif
25294 #ifdef INET
25295 	case IPPROTO_IP:
25296 		switch (sopt->sopt_name) {
25297 		case IP_TOS:
25298 			/*
25299 			 * The DSCP codepoint has changed, update the fsb.
25300 			 */
25301 			ip->ip_tos = rack->rc_inp->inp_ip_tos;
25302 			break;
25303 		case IP_TTL:
25304 			/*
25305 			 * The TTL has changed, update the fsb.
25306 			 */
25307 			ip->ip_ttl = rack->rc_inp->inp_ip_ttl;
25308 			break;
25309 		}
25310 		INP_WUNLOCK(inp);
25311 		return (0);
25312 #endif
25313 #ifdef SO_PEERPRIO
25314 	case SOL_SOCKET:
25315 		switch (sopt->sopt_name) {
25316 		case SO_PEERPRIO:			/*  SC-URL:bs */
25317 			/* Already read in and sanity checked in sosetopt(). */
25318 			if (inp->inp_socket) {
25319 				rack->client_bufferlvl = inp->inp_socket->so_peerprio;
25320 			}
25321 			break;
25322 		}
25323 		INP_WUNLOCK(inp);
25324 		return (0);
25325 #endif
25326 	case IPPROTO_TCP:
25327 		switch (sopt->sopt_name) {
25328 		case TCP_RACK_TLP_REDUCE:		/*  URL:tlp_reduce */
25329 		/*  Pacing related ones */
25330 		case TCP_RACK_PACE_ALWAYS:		/*  URL:pace_always */
25331 		case TCP_BBR_RACK_INIT_RATE:		/*  URL:irate */
25332 		case TCP_RACK_PACE_MIN_SEG:		/*  URL:pace_min_seg */
25333 		case TCP_RACK_PACE_MAX_SEG:		/*  URL:pace_max_seg */
25334 		case TCP_RACK_FORCE_MSEG:		/*  URL:force_max_seg */
25335 		case TCP_RACK_PACE_RATE_CA:		/*  URL:pr_ca */
25336 		case TCP_RACK_PACE_RATE_SS:		/*  URL:pr_ss*/
25337 		case TCP_RACK_PACE_RATE_REC:		/*  URL:pr_rec */
25338 		case TCP_RACK_GP_INCREASE_CA:		/*  URL:gp_inc_ca */
25339 		case TCP_RACK_GP_INCREASE_SS:		/*  URL:gp_inc_ss */
25340 		case TCP_RACK_GP_INCREASE_REC:		/*  URL:gp_inc_rec */
25341 		case TCP_RACK_RR_CONF:			/*  URL:rrr_conf */
25342 		case TCP_BBR_HDWR_PACE:			/*  URL:hdwrpace */
25343 		case TCP_HDWR_RATE_CAP:			/*  URL:hdwrcap boolean */
25344 		case TCP_PACING_RATE_CAP:		/*  URL:cap  -- used by side-channel */
25345 		case TCP_HDWR_UP_ONLY:			/*  URL:uponly -- hardware pacing  boolean */
25346 		case TCP_FILLCW_RATE_CAP:		/*  URL:fillcw_cap */
25347 		case TCP_RACK_PACING_BETA_ECN:		/*  URL:pacing_beta_ecn */
25348 		case TCP_RACK_PACE_TO_FILL:		/*  URL:fillcw */
25349 			/* End pacing related */
25350 		case TCP_POLICER_DETECT:		/*  URL:pol_det */
25351 		case TCP_POLICER_MSS:			/*  URL:pol_mss */
25352 		case TCP_DELACK:			/*  URL:delack (in base TCP i.e. tcp_hints along with cc etc ) */
25353 		case TCP_RACK_PRR_SENDALOT:		/*  URL:prr_sendalot */
25354 		case TCP_RACK_MIN_TO:			/*  URL:min_to */
25355 		case TCP_RACK_EARLY_SEG:		/*  URL:early_seg */
25356 		case TCP_RACK_REORD_THRESH:		/*  URL:reord_thresh */
25357 		case TCP_RACK_REORD_FADE:		/*  URL:reord_fade */
25358 		case TCP_RACK_TLP_THRESH:		/*  URL:tlp_thresh */
25359 		case TCP_RACK_PKT_DELAY:		/*  URL:pkt_delay */
25360 		case TCP_RACK_TLP_USE:			/*  URL:tlp_use */
25361 		case TCP_BBR_RACK_RTT_USE:		/*  URL:rttuse */
25362 		case TCP_BBR_USE_RACK_RR:		/*  URL:rackrr */
25363 		case TCP_NO_PRR:			/*  URL:noprr */
25364 		case TCP_TIMELY_DYN_ADJ:      		/*  URL:dynamic */
25365 		case TCP_DATA_AFTER_CLOSE:		/*  no URL */
25366 		case TCP_RACK_NONRXT_CFG_RATE:		/*  URL:nonrxtcr */
25367 		case TCP_SHARED_CWND_ENABLE:		/*  URL:scwnd */
25368 		case TCP_RACK_MBUF_QUEUE:		/*  URL:mqueue */
25369 		case TCP_RACK_NO_PUSH_AT_MAX:		/*  URL:npush */
25370 		case TCP_SHARED_CWND_TIME_LIMIT:	/*  URL:lscwnd */
25371 		case TCP_RACK_PROFILE:			/*  URL:profile */
25372 		case TCP_SIDECHAN_DIS:			/*  URL:scodm */
25373 		case TCP_HYBRID_PACING:			/*  URL:pacing=hybrid */
25374 		case TCP_USE_CMP_ACKS:			/*  URL:cmpack */
25375 		case TCP_RACK_ABC_VAL:			/*  URL:labc */
25376 		case TCP_REC_ABC_VAL:			/*  URL:reclabc */
25377 		case TCP_RACK_MEASURE_CNT:		/*  URL:measurecnt */
25378 		case TCP_DEFER_OPTIONS:			/*  URL:defer */
25379 		case TCP_RACK_DSACK_OPT:		/*  URL:dsack */
25380 		case TCP_RACK_TIMER_SLOP:		/*  URL:timer_slop */
25381 		case TCP_RACK_ENABLE_HYSTART:		/*  URL:hystart */
25382 		case TCP_RACK_SET_RXT_OPTIONS:		/*  URL:rxtsz */
25383 		case TCP_RACK_HI_BETA:			/*  URL:hibeta */
25384 		case TCP_RACK_SPLIT_LIMIT:		/*  URL:split */
25385 		case TCP_SS_EEXIT:			/*  URL:eexit */
25386 		case TCP_DGP_UPPER_BOUNDS:		/*  URL:upper */
25387 		case TCP_RACK_PACING_DIVISOR:		/*  URL:divisor */
25388 		case TCP_PACING_DND:			/*  URL:dnd */
25389 		case TCP_NO_TIMELY:			/*  URL:notimely */
25390 		case RACK_CSPR_IS_FCC:			/*  URL:csprisfcc */
25391 		case TCP_HONOR_HPTS_MIN:		/*  URL:hptsmin */
25392 		case TCP_REC_IS_DYN:			/*  URL:dynrec */
25393 		case TCP_GP_USE_LTBW:			/*  URL:useltbw */
25394 			goto process_opt;
25395 			break;
25396 		default:
25397 			/* Filter off all unknown options to the base stack */
25398 			return (tcp_default_ctloutput(tp, sopt));
25399 			break;
25400 		}
25401 	default:
25402 		INP_WUNLOCK(inp);
25403 		return (0);
25404 	}
25405 process_opt:
25406 	INP_WUNLOCK(inp);
25407 	if ((sopt->sopt_name == TCP_PACING_RATE_CAP) ||
25408 	    (sopt->sopt_name == TCP_FILLCW_RATE_CAP)) {
25409 		error = sooptcopyin(sopt, &loptval, sizeof(loptval), sizeof(loptval));
25410 		/*
25411 		 * We truncate it down to 32 bits for the socket-option trace this
25412 		 * means rates > 34Gbps won't show right, but thats probably ok.
25413 		 */
25414 		optval = (uint32_t)loptval;
25415 	} else if (sopt->sopt_name == TCP_HYBRID_PACING) {
25416 		error = sooptcopyin(sopt, &hybrid, sizeof(hybrid), sizeof(hybrid));
25417 	} else {
25418 		error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval));
25419 		/* Save it in 64 bit form too */
25420 		loptval = optval;
25421 	}
25422 	if (error)
25423 		return (error);
25424 	INP_WLOCK(inp);
25425 	if (tp->t_fb != &__tcp_rack) {
25426 		INP_WUNLOCK(inp);
25427 		return (ENOPROTOOPT);
25428 	}
25429 	if (rack->defer_options && (rack->gp_ready == 0) &&
25430 	    (sopt->sopt_name != TCP_DEFER_OPTIONS) &&
25431 	    (sopt->sopt_name != TCP_HYBRID_PACING) &&
25432 	    (sopt->sopt_name != TCP_RACK_SET_RXT_OPTIONS) &&
25433 	    (sopt->sopt_name != TCP_RACK_PACING_BETA_ECN) &&
25434 	    (sopt->sopt_name != TCP_RACK_MEASURE_CNT)) {
25435 		/* Options are being deferred */
25436 		if (rack_add_deferred_option(rack, sopt->sopt_name, loptval)) {
25437 			INP_WUNLOCK(inp);
25438 			return (0);
25439 		} else {
25440 			/* No memory to defer, fail */
25441 			INP_WUNLOCK(inp);
25442 			return (ENOMEM);
25443 		}
25444 	}
25445 	error = rack_process_option(tp, rack, sopt->sopt_name, optval, loptval, &hybrid);
25446 	INP_WUNLOCK(inp);
25447 	return (error);
25448 }
25449 
25450 static void
rack_fill_info(struct tcpcb * tp,struct tcp_info * ti)25451 rack_fill_info(struct tcpcb *tp, struct tcp_info *ti)
25452 {
25453 
25454 	INP_WLOCK_ASSERT(tptoinpcb(tp));
25455 	bzero(ti, sizeof(*ti));
25456 
25457 	ti->tcpi_state = tp->t_state;
25458 	if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
25459 		ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
25460 	if (tp->t_flags & TF_SACK_PERMIT)
25461 		ti->tcpi_options |= TCPI_OPT_SACK;
25462 	if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
25463 		ti->tcpi_options |= TCPI_OPT_WSCALE;
25464 		ti->tcpi_snd_wscale = tp->snd_scale;
25465 		ti->tcpi_rcv_wscale = tp->rcv_scale;
25466 	}
25467 	if (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))
25468 		ti->tcpi_options |= TCPI_OPT_ECN;
25469 	if (tp->t_flags & TF_FASTOPEN)
25470 		ti->tcpi_options |= TCPI_OPT_TFO;
25471 	/* still kept in ticks is t_rcvtime */
25472 	ti->tcpi_last_data_recv = ((uint32_t)ticks - tp->t_rcvtime) * tick;
25473 	/* Since we hold everything in precise useconds this is easy */
25474 	ti->tcpi_rtt = tp->t_srtt;
25475 	ti->tcpi_rttvar = tp->t_rttvar;
25476 	ti->tcpi_rto = tp->t_rxtcur;
25477 	ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
25478 	ti->tcpi_snd_cwnd = tp->snd_cwnd;
25479 	/*
25480 	 * FreeBSD-specific extension fields for tcp_info.
25481 	 */
25482 	ti->tcpi_rcv_space = tp->rcv_wnd;
25483 	ti->tcpi_rcv_nxt = tp->rcv_nxt;
25484 	ti->tcpi_snd_wnd = tp->snd_wnd;
25485 	ti->tcpi_snd_bwnd = 0;		/* Unused, kept for compat. */
25486 	ti->tcpi_snd_nxt = tp->snd_nxt;
25487 	ti->tcpi_snd_mss = tp->t_maxseg;
25488 	ti->tcpi_rcv_mss = tp->t_maxseg;
25489 	ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;
25490 	ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
25491 	ti->tcpi_snd_zerowin = tp->t_sndzerowin;
25492 	ti->tcpi_total_tlp = tp->t_sndtlppack;
25493 	ti->tcpi_total_tlp_bytes = tp->t_sndtlpbyte;
25494 	ti->tcpi_rttmin = tp->t_rttlow;
25495 #ifdef NETFLIX_STATS
25496 	memcpy(&ti->tcpi_rxsyninfo, &tp->t_rxsyninfo, sizeof(struct tcpsyninfo));
25497 #endif
25498 #ifdef TCP_OFFLOAD
25499 	if (tp->t_flags & TF_TOE) {
25500 		ti->tcpi_options |= TCPI_OPT_TOE;
25501 		tcp_offload_tcp_info(tp, ti);
25502 	}
25503 #endif
25504 }
25505 
25506 static int
rack_get_sockopt(struct tcpcb * tp,struct sockopt * sopt)25507 rack_get_sockopt(struct tcpcb *tp, struct sockopt *sopt)
25508 {
25509 	struct inpcb *inp = tptoinpcb(tp);
25510 	struct tcp_rack *rack;
25511 	int32_t error, optval;
25512 	uint64_t val, loptval;
25513 	struct	tcp_info ti;
25514 	/*
25515 	 * Because all our options are either boolean or an int, we can just
25516 	 * pull everything into optval and then unlock and copy. If we ever
25517 	 * add a option that is not a int, then this will have quite an
25518 	 * impact to this routine.
25519 	 */
25520 	error = 0;
25521 	rack = (struct tcp_rack *)tp->t_fb_ptr;
25522 	if (rack == NULL) {
25523 		INP_WUNLOCK(inp);
25524 		return (EINVAL);
25525 	}
25526 	switch (sopt->sopt_name) {
25527 	case TCP_INFO:
25528 		/* First get the info filled */
25529 		rack_fill_info(tp, &ti);
25530 		/* Fix up the rtt related fields if needed */
25531 		INP_WUNLOCK(inp);
25532 		error = sooptcopyout(sopt, &ti, sizeof ti);
25533 		return (error);
25534 	/*
25535 	 * Beta is the congestion control value for NewReno that influences how
25536 	 * much of a backoff happens when loss is detected. It is normally set
25537 	 * to 50 for 50% i.e. the cwnd is reduced to 50% of its previous value
25538 	 * when you exit recovery.
25539 	 */
25540 	case TCP_RACK_PACING_BETA:
25541 		break;
25542 		/*
25543 		 * Beta_ecn is the congestion control value for NewReno that influences how
25544 		 * much of a backoff happens when a ECN mark is detected. It is normally set
25545 		 * to 80 for 80% i.e. the cwnd is reduced by 20% of its previous value when
25546 		 * you exit recovery. Note that classic ECN has a beta of 50, it is only
25547 		 * ABE Ecn that uses this "less" value, but we do too with pacing :)
25548 		 */
25549 
25550 	case TCP_RACK_PACING_BETA_ECN:
25551 		if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0)
25552 			error = EINVAL;
25553 		else if (rack->rc_pacing_cc_set == 0)
25554 			optval = rack->r_ctl.rc_saved_beta.beta_ecn;
25555 		else {
25556 			/*
25557 			 * Reach out into the CC data and report back what
25558 			 * I have previously set. Yeah it looks hackish but
25559 			 * we don't want to report the saved values.
25560 			 */
25561 			if (tp->t_ccv.cc_data)
25562 				optval = ((struct newreno *)tp->t_ccv.cc_data)->beta_ecn;
25563 			else
25564 				error = EINVAL;
25565 		}
25566 		break;
25567 	case TCP_RACK_DSACK_OPT:
25568 		optval = 0;
25569 		if (rack->rc_rack_tmr_std_based) {
25570 			optval |= 1;
25571 		}
25572 		if (rack->rc_rack_use_dsack) {
25573 			optval |= 2;
25574 		}
25575 		break;
25576 	case TCP_RACK_ENABLE_HYSTART:
25577 	{
25578 		if (tp->t_ccv.flags & CCF_HYSTART_ALLOWED) {
25579 			optval = RACK_HYSTART_ON;
25580 			if (tp->t_ccv.flags & CCF_HYSTART_CAN_SH_CWND)
25581 				optval = RACK_HYSTART_ON_W_SC;
25582 			if (tp->t_ccv.flags & CCF_HYSTART_CONS_SSTH)
25583 				optval = RACK_HYSTART_ON_W_SC_C;
25584 		} else {
25585 			optval = RACK_HYSTART_OFF;
25586 		}
25587 	}
25588 	break;
25589 	case TCP_RACK_DGP_IN_REC:
25590 		error = EINVAL;
25591 		break;
25592 	case TCP_RACK_HI_BETA:
25593 		optval = rack->rack_hibeta;
25594 		break;
25595 	case TCP_POLICER_MSS:
25596 		optval = rack->r_ctl.policer_del_mss;
25597 		break;
25598 	case TCP_POLICER_DETECT:
25599 		optval = rack->r_ctl.saved_policer_val;
25600 		break;
25601 	case TCP_DEFER_OPTIONS:
25602 		optval = rack->defer_options;
25603 		break;
25604 	case TCP_RACK_MEASURE_CNT:
25605 		optval = rack->r_ctl.req_measurements;
25606 		break;
25607 	case TCP_REC_ABC_VAL:
25608 		optval = rack->r_use_labc_for_rec;
25609 		break;
25610 	case TCP_RACK_ABC_VAL:
25611 		optval = rack->rc_labc;
25612 		break;
25613 	case TCP_HDWR_UP_ONLY:
25614 		optval= rack->r_up_only;
25615 		break;
25616 	case TCP_FILLCW_RATE_CAP:
25617 		loptval = rack->r_ctl.fillcw_cap;
25618 		break;
25619 	case TCP_PACING_RATE_CAP:
25620 		loptval = rack->r_ctl.bw_rate_cap;
25621 		break;
25622 	case TCP_RACK_PROFILE:
25623 		/* You cannot retrieve a profile, its write only */
25624 		error = EINVAL;
25625 		break;
25626 	case TCP_SIDECHAN_DIS:
25627 		optval = rack->r_ctl.side_chan_dis_mask;
25628 		break;
25629 	case TCP_HYBRID_PACING:
25630 		/* You cannot retrieve hybrid pacing information, its write only */
25631 		error = EINVAL;
25632 		break;
25633 	case TCP_USE_CMP_ACKS:
25634 		optval = rack->r_use_cmp_ack;
25635 		break;
25636 	case TCP_RACK_PACE_TO_FILL:
25637 		optval = rack->rc_pace_to_cwnd;
25638 		break;
25639 	case TCP_RACK_NO_PUSH_AT_MAX:
25640 		optval = rack->r_ctl.rc_no_push_at_mrtt;
25641 		break;
25642 	case TCP_SHARED_CWND_ENABLE:
25643 		optval = rack->rack_enable_scwnd;
25644 		break;
25645 	case TCP_RACK_NONRXT_CFG_RATE:
25646 		optval = rack->rack_rec_nonrxt_use_cr;
25647 		break;
25648 	case TCP_NO_PRR:
25649 		if (rack->rack_no_prr  == 1)
25650 			optval = 1;
25651 		else if (rack->no_prr_addback == 1)
25652 			optval = 2;
25653 		else
25654 			optval = 0;
25655 		break;
25656 	case TCP_GP_USE_LTBW:
25657 		if (rack->dis_lt_bw) {
25658 			/* It is not used */
25659 			optval = 0;
25660 		} else if (rack->use_lesser_lt_bw) {
25661 			/* we use min() */
25662 			optval = 1;
25663 		} else {
25664 			/* we use max() */
25665 			optval = 2;
25666 		}
25667 		break;
25668 	case TCP_RACK_DO_DETECTION:
25669 		error = EINVAL;
25670 		break;
25671 	case TCP_RACK_MBUF_QUEUE:
25672 		/* Now do we use the LRO mbuf-queue feature */
25673 		optval = rack->r_mbuf_queue;
25674 		break;
25675 	case RACK_CSPR_IS_FCC:
25676 		optval = rack->cspr_is_fcc;
25677 		break;
25678 	case TCP_TIMELY_DYN_ADJ:
25679 		optval = rack->rc_gp_dyn_mul;
25680 		break;
25681 	case TCP_BBR_IWINTSO:
25682 		error = EINVAL;
25683 		break;
25684 	case TCP_RACK_TLP_REDUCE:
25685 		/* RACK TLP cwnd reduction (bool) */
25686 		optval = rack->r_ctl.rc_tlp_cwnd_reduce;
25687 		break;
25688 	case TCP_BBR_RACK_INIT_RATE:
25689 		val = rack->r_ctl.init_rate;
25690 		/* convert to kbits per sec */
25691 		val *= 8;
25692 		val /= 1000;
25693 		optval = (uint32_t)val;
25694 		break;
25695 	case TCP_RACK_FORCE_MSEG:
25696 		optval = rack->rc_force_max_seg;
25697 		break;
25698 	case TCP_RACK_PACE_MIN_SEG:
25699 		optval = rack->r_ctl.rc_user_set_min_segs;
25700 		break;
25701 	case TCP_RACK_PACE_MAX_SEG:
25702 		/* Max segments in a pace */
25703 		optval = rack->rc_user_set_max_segs;
25704 		break;
25705 	case TCP_RACK_PACE_ALWAYS:
25706 		/* Use the always pace method */
25707 		optval = rack->rc_always_pace;
25708 		break;
25709 	case TCP_RACK_PRR_SENDALOT:
25710 		/* Allow PRR to send more than one seg */
25711 		optval = rack->r_ctl.rc_prr_sendalot;
25712 		break;
25713 	case TCP_RACK_MIN_TO:
25714 		/* Minimum time between rack t-o's in ms */
25715 		optval = rack->r_ctl.rc_min_to;
25716 		break;
25717 	case TCP_RACK_SPLIT_LIMIT:
25718 		optval = rack->r_ctl.rc_split_limit;
25719 		break;
25720 	case TCP_RACK_EARLY_SEG:
25721 		/* If early recovery max segments */
25722 		optval = rack->r_ctl.rc_early_recovery_segs;
25723 		break;
25724 	case TCP_RACK_REORD_THRESH:
25725 		/* RACK reorder threshold (shift amount) */
25726 		optval = rack->r_ctl.rc_reorder_shift;
25727 		break;
25728 	case TCP_SS_EEXIT:
25729 		if (rack->r_ctl.gp_rnd_thresh) {
25730 			uint32_t v;
25731 
25732 			v = rack->r_ctl.gp_gain_req;
25733 			v <<= 17;
25734 			optval = v | (rack->r_ctl.gp_rnd_thresh & 0xff);
25735 			if (rack->r_ctl.gate_to_fs == 1)
25736 				optval |= 0x10000;
25737 		} else
25738 			optval = 0;
25739 		break;
25740 	case TCP_RACK_REORD_FADE:
25741 		/* Does reordering fade after ms time */
25742 		optval = rack->r_ctl.rc_reorder_fade;
25743 		break;
25744 	case TCP_BBR_USE_RACK_RR:
25745 		/* Do we use the rack cheat for rxt */
25746 		optval = rack->use_rack_rr;
25747 		break;
25748 	case TCP_RACK_RR_CONF:
25749 		optval = rack->r_rr_config;
25750 		break;
25751 	case TCP_HDWR_RATE_CAP:
25752 		optval = rack->r_rack_hw_rate_caps;
25753 		break;
25754 	case TCP_BBR_HDWR_PACE:
25755 		optval = rack->rack_hdw_pace_ena;
25756 		break;
25757 	case TCP_RACK_TLP_THRESH:
25758 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
25759 		optval = rack->r_ctl.rc_tlp_threshold;
25760 		break;
25761 	case TCP_RACK_PKT_DELAY:
25762 		/* RACK added ms i.e. rack-rtt + reord + N */
25763 		optval = rack->r_ctl.rc_pkt_delay;
25764 		break;
25765 	case TCP_RACK_TLP_USE:
25766 		optval = rack->rack_tlp_threshold_use;
25767 		break;
25768 	case TCP_PACING_DND:
25769 		optval = rack->rc_pace_dnd;
25770 		break;
25771 	case TCP_RACK_PACE_RATE_CA:
25772 		optval = rack->r_ctl.rc_fixed_pacing_rate_ca;
25773 		break;
25774 	case TCP_RACK_PACE_RATE_SS:
25775 		optval = rack->r_ctl.rc_fixed_pacing_rate_ss;
25776 		break;
25777 	case TCP_RACK_PACE_RATE_REC:
25778 		optval = rack->r_ctl.rc_fixed_pacing_rate_rec;
25779 		break;
25780 	case TCP_DGP_UPPER_BOUNDS:
25781 		optval = rack->r_ctl.rack_per_upper_bound_ss;
25782 		optval <<= 16;
25783 		optval |= rack->r_ctl.rack_per_upper_bound_ca;
25784 		break;
25785 	case TCP_RACK_GP_INCREASE_SS:
25786 		optval = rack->r_ctl.rack_per_of_gp_ca;
25787 		break;
25788 	case TCP_RACK_GP_INCREASE_CA:
25789 		optval = rack->r_ctl.rack_per_of_gp_ss;
25790 		break;
25791 	case TCP_RACK_PACING_DIVISOR:
25792 		optval = rack->r_ctl.pace_len_divisor;
25793 		break;
25794 	case TCP_BBR_RACK_RTT_USE:
25795 		optval = rack->r_ctl.rc_rate_sample_method;
25796 		break;
25797 	case TCP_DELACK:
25798 		optval = tp->t_delayed_ack;
25799 		break;
25800 	case TCP_DATA_AFTER_CLOSE:
25801 		optval = rack->rc_allow_data_af_clo;
25802 		break;
25803 	case TCP_SHARED_CWND_TIME_LIMIT:
25804 		optval = rack->r_limit_scw;
25805 		break;
25806 	case TCP_HONOR_HPTS_MIN:
25807 		if (rack->r_use_hpts_min)
25808 			optval = rack->r_ctl.max_reduction;
25809 		else
25810 			optval = 0;
25811 		break;
25812 	case TCP_REC_IS_DYN:
25813 		optval = rack->rc_gp_no_rec_chg;
25814 		break;
25815 	case TCP_NO_TIMELY:
25816 		optval = rack->rc_skip_timely;
25817 		break;
25818 	case TCP_RACK_TIMER_SLOP:
25819 		optval = rack->r_ctl.timer_slop;
25820 		break;
25821 	default:
25822 		return (tcp_default_ctloutput(tp, sopt));
25823 		break;
25824 	}
25825 	INP_WUNLOCK(inp);
25826 	if (error == 0) {
25827 		if ((sopt->sopt_name == TCP_PACING_RATE_CAP) ||
25828 		    (sopt->sopt_name == TCP_FILLCW_RATE_CAP))
25829 			error = sooptcopyout(sopt, &loptval, sizeof loptval);
25830 		else
25831 			error = sooptcopyout(sopt, &optval, sizeof optval);
25832 	}
25833 	return (error);
25834 }
25835 
25836 static int
rack_ctloutput(struct tcpcb * tp,struct sockopt * sopt)25837 rack_ctloutput(struct tcpcb *tp, struct sockopt *sopt)
25838 {
25839 	if (sopt->sopt_dir == SOPT_SET) {
25840 		return (rack_set_sockopt(tp, sopt));
25841 	} else if (sopt->sopt_dir == SOPT_GET) {
25842 		return (rack_get_sockopt(tp, sopt));
25843 	} else {
25844 		panic("%s: sopt_dir $%d", __func__, sopt->sopt_dir);
25845 	}
25846 }
25847 
25848 static const char *rack_stack_names[] = {
25849 	__XSTRING(STACKNAME),
25850 #ifdef STACKALIAS
25851 	__XSTRING(STACKALIAS),
25852 #endif
25853 };
25854 
25855 static int
rack_ctor(void * mem,int32_t size,void * arg,int32_t how)25856 rack_ctor(void *mem, int32_t size, void *arg, int32_t how)
25857 {
25858 	memset(mem, 0, size);
25859 	return (0);
25860 }
25861 
25862 static void
rack_dtor(void * mem,int32_t size,void * arg)25863 rack_dtor(void *mem, int32_t size, void *arg)
25864 {
25865 
25866 }
25867 
25868 static bool rack_mod_inited = false;
25869 
25870 static int
tcp_addrack(module_t mod,int32_t type,void * data)25871 tcp_addrack(module_t mod, int32_t type, void *data)
25872 {
25873 	int32_t err = 0;
25874 	int num_stacks;
25875 
25876 	switch (type) {
25877 	case MOD_LOAD:
25878 		rack_zone = uma_zcreate(__XSTRING(MODNAME) "_map",
25879 		    sizeof(struct rack_sendmap),
25880 		    rack_ctor, rack_dtor, NULL, NULL, UMA_ALIGN_PTR, 0);
25881 
25882 		rack_pcb_zone = uma_zcreate(__XSTRING(MODNAME) "_pcb",
25883 		    sizeof(struct tcp_rack),
25884 		    rack_ctor, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
25885 
25886 		sysctl_ctx_init(&rack_sysctl_ctx);
25887 		rack_sysctl_root = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
25888 		    SYSCTL_STATIC_CHILDREN(_net_inet_tcp),
25889 		    OID_AUTO,
25890 #ifdef STACKALIAS
25891 		    __XSTRING(STACKALIAS),
25892 #else
25893 		    __XSTRING(STACKNAME),
25894 #endif
25895 		    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
25896 		    "");
25897 		if (rack_sysctl_root == NULL) {
25898 			printf("Failed to add sysctl node\n");
25899 			err = EFAULT;
25900 			goto free_uma;
25901 		}
25902 		rack_init_sysctls();
25903 		num_stacks = nitems(rack_stack_names);
25904 		err = register_tcp_functions_as_names(&__tcp_rack, M_WAITOK,
25905 		    rack_stack_names, &num_stacks);
25906 		if (err) {
25907 			printf("Failed to register %s stack name for "
25908 			    "%s module\n", rack_stack_names[num_stacks],
25909 			    __XSTRING(MODNAME));
25910 			sysctl_ctx_free(&rack_sysctl_ctx);
25911 free_uma:
25912 			uma_zdestroy(rack_zone);
25913 			uma_zdestroy(rack_pcb_zone);
25914 			rack_counter_destroy();
25915 			printf("Failed to register rack module -- err:%d\n", err);
25916 			return (err);
25917 		}
25918 		tcp_lro_reg_mbufq();
25919 		rack_mod_inited = true;
25920 		break;
25921 	case MOD_QUIESCE:
25922 		err = deregister_tcp_functions(&__tcp_rack, true, false);
25923 		break;
25924 	case MOD_UNLOAD:
25925 		err = deregister_tcp_functions(&__tcp_rack, false, true);
25926 		if (err == EBUSY)
25927 			break;
25928 		if (rack_mod_inited) {
25929 			uma_zdestroy(rack_zone);
25930 			uma_zdestroy(rack_pcb_zone);
25931 			sysctl_ctx_free(&rack_sysctl_ctx);
25932 			rack_counter_destroy();
25933 			rack_mod_inited = false;
25934 		}
25935 		tcp_lro_dereg_mbufq();
25936 		err = 0;
25937 		break;
25938 	default:
25939 		return (EOPNOTSUPP);
25940 	}
25941 	return (err);
25942 }
25943 
25944 static moduledata_t tcp_rack = {
25945 	.name = __XSTRING(MODNAME),
25946 	.evhand = tcp_addrack,
25947 	.priv = 0
25948 };
25949 
25950 MODULE_VERSION(MODNAME, 1);
25951 DECLARE_MODULE(MODNAME, tcp_rack, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
25952 MODULE_DEPEND(MODNAME, tcphpts, 1, 1, 1);
25953 
25954 #endif /* #if !defined(INET) && !defined(INET6) */
25955