xref: /freebsd/sys/netinet/tcp_stacks/rack.c (revision 2b833162) 
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 __FBSDID("$FreeBSD$");
29 
30 #include "opt_inet.h"
31 #include "opt_inet6.h"
32 #include "opt_ipsec.h"
33 #include "opt_ratelimit.h"
34 #include "opt_kern_tls.h"
35 #if defined(INET) || defined(INET6)
36 #include <sys/param.h>
37 #include <sys/arb.h>
38 #include <sys/module.h>
39 #include <sys/kernel.h>
40 #ifdef TCP_HHOOK
41 #include <sys/hhook.h>
42 #endif
43 #include <sys/lock.h>
44 #include <sys/malloc.h>
45 #include <sys/lock.h>
46 #include <sys/mutex.h>
47 #include <sys/mbuf.h>
48 #include <sys/proc.h>		/* for proc0 declaration */
49 #include <sys/socket.h>
50 #include <sys/socketvar.h>
51 #include <sys/sysctl.h>
52 #include <sys/systm.h>
53 #ifdef STATS
54 #include <sys/qmath.h>
55 #include <sys/tree.h>
56 #include <sys/stats.h> /* Must come after qmath.h and tree.h */
57 #else
58 #include <sys/tree.h>
59 #endif
60 #include <sys/refcount.h>
61 #include <sys/queue.h>
62 #include <sys/tim_filter.h>
63 #include <sys/smp.h>
64 #include <sys/kthread.h>
65 #include <sys/kern_prefetch.h>
66 #include <sys/protosw.h>
67 #ifdef TCP_ACCOUNTING
68 #include <sys/sched.h>
69 #include <machine/cpu.h>
70 #endif
71 #include <vm/uma.h>
72 
73 #include <net/route.h>
74 #include <net/route/nhop.h>
75 #include <net/vnet.h>
76 
77 #define TCPSTATES		/* for logging */
78 
79 #include <netinet/in.h>
80 #include <netinet/in_kdtrace.h>
81 #include <netinet/in_pcb.h>
82 #include <netinet/ip.h>
83 #include <netinet/ip_icmp.h>	/* required for icmp_var.h */
84 #include <netinet/icmp_var.h>	/* for ICMP_BANDLIM */
85 #include <netinet/ip_var.h>
86 #include <netinet/ip6.h>
87 #include <netinet6/in6_pcb.h>
88 #include <netinet6/ip6_var.h>
89 #include <netinet/tcp.h>
90 #define	TCPOUTFLAGS
91 #include <netinet/tcp_fsm.h>
92 #include <netinet/tcp_seq.h>
93 #include <netinet/tcp_timer.h>
94 #include <netinet/tcp_var.h>
95 #include <netinet/tcp_log_buf.h>
96 #include <netinet/tcp_syncache.h>
97 #include <netinet/tcp_hpts.h>
98 #include <netinet/tcp_ratelimit.h>
99 #include <netinet/tcp_accounting.h>
100 #include <netinet/tcpip.h>
101 #include <netinet/cc/cc.h>
102 #include <netinet/cc/cc_newreno.h>
103 #include <netinet/tcp_fastopen.h>
104 #include <netinet/tcp_lro.h>
105 #ifdef NETFLIX_SHARED_CWND
106 #include <netinet/tcp_shared_cwnd.h>
107 #endif
108 #ifdef TCP_OFFLOAD
109 #include <netinet/tcp_offload.h>
110 #endif
111 #ifdef INET6
112 #include <netinet6/tcp6_var.h>
113 #endif
114 #include <netinet/tcp_ecn.h>
115 
116 #include <netipsec/ipsec_support.h>
117 
118 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
119 #include <netipsec/ipsec.h>
120 #include <netipsec/ipsec6.h>
121 #endif				/* IPSEC */
122 
123 #include <netinet/udp.h>
124 #include <netinet/udp_var.h>
125 #include <machine/in_cksum.h>
126 
127 #ifdef MAC
128 #include <security/mac/mac_framework.h>
129 #endif
130 #include "sack_filter.h"
131 #include "tcp_rack.h"
132 #include "tailq_hash.h"
133 #include "rack_bbr_common.h"
134 
135 uma_zone_t rack_zone;
136 uma_zone_t rack_pcb_zone;
137 
138 #ifndef TICKS2SBT
139 #define	TICKS2SBT(__t)	(tick_sbt * ((sbintime_t)(__t)))
140 #endif
141 
142 VNET_DECLARE(uint32_t, newreno_beta);
143 VNET_DECLARE(uint32_t, newreno_beta_ecn);
144 #define V_newreno_beta VNET(newreno_beta)
145 #define V_newreno_beta_ecn VNET(newreno_beta_ecn)
146 
147 
148 MALLOC_DEFINE(M_TCPFSB, "tcp_fsb", "TCP fast send block");
149 MALLOC_DEFINE(M_TCPDO, "tcp_do", "TCP deferred options");
150 
151 struct sysctl_ctx_list rack_sysctl_ctx;
152 struct sysctl_oid *rack_sysctl_root;
153 
154 #define CUM_ACKED 1
155 #define SACKED 2
156 
157 /*
158  * The RACK module incorporates a number of
159  * TCP ideas that have been put out into the IETF
160  * over the last few years:
161  * - Matt Mathis's Rate Halving which slowly drops
162  *    the congestion window so that the ack clock can
163  *    be maintained during a recovery.
164  * - Yuchung Cheng's RACK TCP (for which its named) that
165  *    will stop us using the number of dup acks and instead
166  *    use time as the gage of when we retransmit.
167  * - Reorder Detection of RFC4737 and the Tail-Loss probe draft
168  *    of Dukkipati et.al.
169  * RACK depends on SACK, so if an endpoint arrives that
170  * cannot do SACK the state machine below will shuttle the
171  * connection back to using the "default" TCP stack that is
172  * in FreeBSD.
173  *
174  * To implement RACK the original TCP stack was first decomposed
175  * into a functional state machine with individual states
176  * for each of the possible TCP connection states. The do_segment
177  * functions role in life is to mandate the connection supports SACK
178  * initially and then assure that the RACK state matches the conenction
179  * state before calling the states do_segment function. Each
180  * state is simplified due to the fact that the original do_segment
181  * has been decomposed and we *know* what state we are in (no
182  * switches on the state) and all tests for SACK are gone. This
183  * greatly simplifies what each state does.
184  *
185  * TCP output is also over-written with a new version since it
186  * must maintain the new rack scoreboard.
187  *
188  */
189 static int32_t rack_tlp_thresh = 1;
190 static int32_t rack_tlp_limit = 2;	/* No more than 2 TLPs w-out new data */
191 static int32_t rack_tlp_use_greater = 1;
192 static int32_t rack_reorder_thresh = 2;
193 static int32_t rack_reorder_fade = 60000000;	/* 0 - never fade, def 60,000,000
194 						 * - 60 seconds */
195 static uint32_t rack_clamp_ss_upper = 110;
196 static uint32_t rack_clamp_ca_upper = 105;
197 static uint32_t rack_rxt_min_rnds = 10;	/* Min rounds if drastic rxt clamp is in place */
198 static uint32_t rack_unclamp_round_thresh = 100;	/* number of perfect rounds before we unclamp */
199 static uint32_t rack_unclamp_rxt_thresh = 5;	/* .5%  and under */
200 static uint64_t rack_rxt_clamp_thresh = 0;	/* Do we do the rxt clamp thing */
201 static int32_t rack_dnd_default = 0;		/* For rr_conf = 3, what is the default for dnd */
202 static int32_t rack_rxt_controls = 0;
203 static int32_t rack_fill_cw_state = 0;
204 static uint8_t rack_req_measurements = 1;
205 /* Attack threshold detections */
206 static uint32_t rack_highest_sack_thresh_seen = 0;
207 static uint32_t rack_highest_move_thresh_seen = 0;
208 static uint32_t rack_merge_out_sacks_on_attack = 0;
209 static int32_t rack_enable_hw_pacing = 0; /* Due to CCSP keep it off by default */
210 static int32_t rack_hw_pace_extra_slots = 0;	/* 2 extra MSS time betweens */
211 static int32_t rack_hw_rate_caps = 0; /* 1; */
212 static int32_t rack_hw_rate_cap_per = 0;	/* 0 -- off  */
213 static int32_t rack_hw_rate_min = 0; /* 1500000;*/
214 static int32_t rack_hw_rate_to_low = 0; /* 1200000; */
215 static int32_t rack_hw_up_only = 0;
216 static int32_t rack_stats_gets_ms_rtt = 1;
217 static int32_t rack_prr_addbackmax = 2;
218 static int32_t rack_do_hystart = 0;
219 static int32_t rack_apply_rtt_with_reduced_conf = 0;
220 static int32_t rack_hibeta_setting = 0;
221 static int32_t rack_default_pacing_divisor = 250;
222 static int32_t rack_uses_full_dgp_in_rec = 1;
223 static uint16_t rack_pacing_min_seg = 0;
224 
225 
226 static uint32_t sad_seg_size_per = 800;	/* 80.0 % */
227 static int32_t rack_pkt_delay = 1000;
228 static int32_t rack_send_a_lot_in_prr = 1;
229 static int32_t rack_min_to = 1000;	/* Number of microsecond  min timeout */
230 static int32_t rack_verbose_logging = 0;
231 static int32_t rack_ignore_data_after_close = 1;
232 static int32_t rack_enable_shared_cwnd = 1;
233 static int32_t rack_use_cmp_acks = 1;
234 static int32_t rack_use_fsb = 1;
235 static int32_t rack_use_rfo = 1;
236 static int32_t rack_use_rsm_rfo = 1;
237 static int32_t rack_max_abc_post_recovery = 2;
238 static int32_t rack_client_low_buf = 0;
239 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 */
240 static int32_t rack_bw_multipler = 2;		/* Limit on fill cw's jump up to be this x gp_est */
241 #ifdef TCP_ACCOUNTING
242 static int32_t rack_tcp_accounting = 0;
243 #endif
244 static int32_t rack_limits_scwnd = 1;
245 static int32_t rack_enable_mqueue_for_nonpaced = 0;
246 static int32_t rack_hybrid_allow_set_maxseg = 0;
247 static int32_t rack_disable_prr = 0;
248 static int32_t use_rack_rr = 1;
249 static int32_t rack_non_rxt_use_cr = 0; /* does a non-rxt in recovery use the configured rate (ss/ca)? */
250 static int32_t rack_persist_min = 250000;	/* 250usec */
251 static int32_t rack_persist_max = 2000000;	/* 2 Second in usec's */
252 static int32_t rack_sack_not_required = 1;	/* set to one to allow non-sack to use rack */
253 static int32_t rack_default_init_window = 0;	/* Use system default */
254 static int32_t rack_limit_time_with_srtt = 0;
255 static int32_t rack_autosndbuf_inc = 20;	/* In percentage form */
256 static int32_t rack_enobuf_hw_boost_mult = 0;	/* How many times the hw rate we boost slot using time_between */
257 static int32_t rack_enobuf_hw_max = 12000;	/* 12 ms in usecs */
258 static int32_t rack_enobuf_hw_min = 10000;	/* 10 ms in usecs */
259 static int32_t rack_hw_rwnd_factor = 2;		/* How many max_segs the rwnd must be before we hold off sending */
260 static int32_t rack_hw_check_queue = 0;		/* Do we always pre-check queue depth of a hw queue */
261 static int32_t rack_full_buffer_discount = 10;
262 /*
263  * Currently regular tcp has a rto_min of 30ms
264  * the backoff goes 12 times so that ends up
265  * being a total of 122.850 seconds before a
266  * connection is killed.
267  */
268 static uint32_t rack_def_data_window = 20;
269 static uint32_t rack_goal_bdp = 2;
270 static uint32_t rack_min_srtts = 1;
271 static uint32_t rack_min_measure_usec = 0;
272 static int32_t rack_tlp_min = 10000;	/* 10ms */
273 static int32_t rack_rto_min = 30000;	/* 30,000 usec same as main freebsd */
274 static int32_t rack_rto_max = 4000000;	/* 4 seconds in usec's */
275 static const int32_t rack_free_cache = 2;
276 static int32_t rack_hptsi_segments = 40;
277 static int32_t rack_rate_sample_method = USE_RTT_LOW;
278 static int32_t rack_pace_every_seg = 0;
279 static int32_t rack_delayed_ack_time = 40000;	/* 40ms in usecs */
280 static int32_t rack_slot_reduction = 4;
281 static int32_t rack_wma_divisor = 8;		/* For WMA calculation */
282 static int32_t rack_cwnd_block_ends_measure = 0;
283 static int32_t rack_rwnd_block_ends_measure = 0;
284 static int32_t rack_def_profile = 0;
285 
286 static int32_t rack_lower_cwnd_at_tlp = 0;
287 static int32_t rack_limited_retran = 0;
288 static int32_t rack_always_send_oldest = 0;
289 static int32_t rack_tlp_threshold_use = TLP_USE_TWO_ONE;
290 
291 static uint16_t rack_per_of_gp_ss = 250;	/* 250 % slow-start */
292 static uint16_t rack_per_of_gp_ca = 200;	/* 200 % congestion-avoidance */
293 static uint16_t rack_per_of_gp_rec = 200;	/* 200 % of bw */
294 
295 /* Probertt */
296 static uint16_t rack_per_of_gp_probertt = 60;	/* 60% of bw */
297 static uint16_t rack_per_of_gp_lowthresh = 40;	/* 40% is bottom */
298 static uint16_t rack_per_of_gp_probertt_reduce = 10; /* 10% reduction */
299 static uint16_t rack_atexit_prtt_hbp = 130;	/* Clamp to 130% on exit prtt if highly buffered path */
300 static uint16_t rack_atexit_prtt = 130;	/* Clamp to 100% on exit prtt if non highly buffered path */
301 
302 static uint32_t rack_max_drain_wait = 2;	/* How man gp srtt's before we give up draining */
303 static uint32_t rack_must_drain = 1;		/* How many GP srtt's we *must* wait */
304 static uint32_t rack_probertt_use_min_rtt_entry = 1;	/* Use the min to calculate the goal else gp_srtt */
305 static uint32_t rack_probertt_use_min_rtt_exit = 0;
306 static uint32_t rack_probe_rtt_sets_cwnd = 0;
307 static uint32_t rack_probe_rtt_safety_val = 2000000;	/* No more than 2 sec in probe-rtt */
308 static uint32_t rack_time_between_probertt = 9600000;	/* 9.6 sec in usecs */
309 static uint32_t rack_probertt_gpsrtt_cnt_mul = 0;	/* How many srtt periods does probe-rtt last top fraction */
310 static uint32_t rack_probertt_gpsrtt_cnt_div = 0;	/* How many srtt periods does probe-rtt last bottom fraction */
311 static uint32_t rack_min_probertt_hold = 40000;		/* Equal to delayed ack time */
312 static uint32_t rack_probertt_filter_life = 10000000;
313 static uint32_t rack_probertt_lower_within = 10;
314 static uint32_t rack_min_rtt_movement = 250000;	/* Must move at least 250ms (in microseconds)  to count as a lowering */
315 static int32_t rack_pace_one_seg = 0;		/* Shall we pace for less than 1.4Meg 1MSS at a time */
316 static int32_t rack_probertt_clear_is = 1;
317 static int32_t rack_max_drain_hbp = 1;		/* Extra drain times gpsrtt for highly buffered paths */
318 static int32_t rack_hbp_thresh = 3;		/* what is the divisor max_rtt/min_rtt to decided a hbp */
319 
320 /* Part of pacing */
321 static int32_t rack_max_per_above = 30;		/* When we go to increment stop if above 100+this% */
322 
323 /* Timely information */
324 /* Combine these two gives the range of 'no change' to bw */
325 /* ie the up/down provide the upper and lower bound */
326 static int32_t rack_gp_per_bw_mul_up = 2;	/* 2% */
327 static int32_t rack_gp_per_bw_mul_down = 4;	/* 4% */
328 static int32_t rack_gp_rtt_maxmul = 3;		/* 3 x maxmin */
329 static int32_t rack_gp_rtt_minmul = 1;		/* minrtt + (minrtt/mindiv) is lower rtt */
330 static int32_t rack_gp_rtt_mindiv = 4;		/* minrtt + (minrtt * minmul/mindiv) is lower rtt */
331 static int32_t rack_gp_decrease_per = 20;	/* 20% decrease in multiplier */
332 static int32_t rack_gp_increase_per = 2;	/* 2% increase in multiplier */
333 static int32_t rack_per_lower_bound = 50;	/* Don't allow to drop below this multiplier */
334 static int32_t rack_per_upper_bound_ss = 0;	/* Don't allow SS to grow above this */
335 static int32_t rack_per_upper_bound_ca = 0;	/* Don't allow CA to grow above this */
336 static int32_t rack_do_dyn_mul = 0;		/* Are the rack gp multipliers dynamic */
337 static int32_t rack_gp_no_rec_chg = 1;		/* Prohibit recovery from reducing it's multiplier */
338 static int32_t rack_timely_dec_clear = 6;	/* Do we clear decrement count at a value (6)? */
339 static int32_t rack_timely_max_push_rise = 3;	/* One round of pushing */
340 static int32_t rack_timely_max_push_drop = 3;	/* Three round of pushing */
341 static int32_t rack_timely_min_segs = 4;	/* 4 segment minimum */
342 static int32_t rack_use_max_for_nobackoff = 0;
343 static int32_t rack_timely_int_timely_only = 0;	/* do interim timely's only use the timely algo (no b/w changes)? */
344 static int32_t rack_timely_no_stopping = 0;
345 static int32_t rack_down_raise_thresh = 100;
346 static int32_t rack_req_segs = 1;
347 static uint64_t rack_bw_rate_cap = 0;
348 
349 
350 /* Rack specific counters */
351 counter_u64_t rack_saw_enobuf;
352 counter_u64_t rack_saw_enobuf_hw;
353 counter_u64_t rack_saw_enetunreach;
354 counter_u64_t rack_persists_sends;
355 counter_u64_t rack_persists_acks;
356 counter_u64_t rack_persists_loss;
357 counter_u64_t rack_persists_lost_ends;
358 counter_u64_t rack_total_bytes;
359 #ifdef INVARIANTS
360 counter_u64_t rack_adjust_map_bw;
361 #endif
362 /* Tail loss probe counters */
363 counter_u64_t rack_tlp_tot;
364 counter_u64_t rack_tlp_newdata;
365 counter_u64_t rack_tlp_retran;
366 counter_u64_t rack_tlp_retran_bytes;
367 counter_u64_t rack_to_tot;
368 counter_u64_t rack_hot_alloc;
369 counter_u64_t rack_to_alloc;
370 counter_u64_t rack_to_alloc_hard;
371 counter_u64_t rack_to_alloc_emerg;
372 counter_u64_t rack_to_alloc_limited;
373 counter_u64_t rack_alloc_limited_conns;
374 counter_u64_t rack_split_limited;
375 counter_u64_t rack_rxt_clamps_cwnd;
376 counter_u64_t rack_rxt_clamps_cwnd_uniq;
377 
378 counter_u64_t rack_multi_single_eq;
379 counter_u64_t rack_proc_non_comp_ack;
380 
381 counter_u64_t rack_fto_send;
382 counter_u64_t rack_fto_rsm_send;
383 counter_u64_t rack_nfto_resend;
384 counter_u64_t rack_non_fto_send;
385 counter_u64_t rack_extended_rfo;
386 
387 counter_u64_t rack_sack_proc_all;
388 counter_u64_t rack_sack_proc_short;
389 counter_u64_t rack_sack_proc_restart;
390 counter_u64_t rack_sack_attacks_detected;
391 counter_u64_t rack_sack_attacks_reversed;
392 counter_u64_t rack_sack_attacks_suspect;
393 counter_u64_t rack_sack_used_next_merge;
394 counter_u64_t rack_sack_splits;
395 counter_u64_t rack_sack_used_prev_merge;
396 counter_u64_t rack_sack_skipped_acked;
397 counter_u64_t rack_ack_total;
398 counter_u64_t rack_express_sack;
399 counter_u64_t rack_sack_total;
400 counter_u64_t rack_move_none;
401 counter_u64_t rack_move_some;
402 
403 counter_u64_t rack_input_idle_reduces;
404 counter_u64_t rack_collapsed_win;
405 counter_u64_t rack_collapsed_win_seen;
406 counter_u64_t rack_collapsed_win_rxt;
407 counter_u64_t rack_collapsed_win_rxt_bytes;
408 counter_u64_t rack_try_scwnd;
409 counter_u64_t rack_hw_pace_init_fail;
410 counter_u64_t rack_hw_pace_lost;
411 
412 counter_u64_t rack_out_size[TCP_MSS_ACCT_SIZE];
413 counter_u64_t rack_opts_arry[RACK_OPTS_SIZE];
414 
415 
416 #define	RACK_REXMTVAL(tp) max(rack_rto_min, ((tp)->t_srtt + ((tp)->t_rttvar << 2)))
417 
418 #define	RACK_TCPT_RANGESET(tv, value, tvmin, tvmax, slop) do {	\
419 	(tv) = (value) + slop;	 \
420 	if ((u_long)(tv) < (u_long)(tvmin)) \
421 		(tv) = (tvmin); \
422 	if ((u_long)(tv) > (u_long)(tvmax)) \
423 		(tv) = (tvmax); \
424 } while (0)
425 
426 static void
427 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick,  int event, int line);
428 
429 static int
430 rack_process_ack(struct mbuf *m, struct tcphdr *th,
431     struct socket *so, struct tcpcb *tp, struct tcpopt *to,
432     uint32_t tiwin, int32_t tlen, int32_t * ofia, int32_t thflags, int32_t * ret_val);
433 static int
434 rack_process_data(struct mbuf *m, struct tcphdr *th,
435     struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
436     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt);
437 static void
438 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack,
439    uint32_t th_ack, uint16_t nsegs, uint16_t type, int32_t recovery);
440 static struct rack_sendmap *rack_alloc(struct tcp_rack *rack);
441 static struct rack_sendmap *rack_alloc_limit(struct tcp_rack *rack,
442     uint8_t limit_type);
443 static struct rack_sendmap *
444 rack_check_recovery_mode(struct tcpcb *tp,
445     uint32_t tsused);
446 static void
447 rack_cong_signal(struct tcpcb *tp,
448 		 uint32_t type, uint32_t ack, int );
449 static void rack_counter_destroy(void);
450 static int
451 rack_ctloutput(struct tcpcb *tp, struct sockopt *sopt);
452 static int32_t rack_ctor(void *mem, int32_t size, void *arg, int32_t how);
453 static void
454 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line, uint64_t *fill_override);
455 static void
456 rack_do_segment(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
457     int32_t drop_hdrlen, int32_t tlen, uint8_t iptos);
458 static void rack_dtor(void *mem, int32_t size, void *arg);
459 static void
460 rack_log_alt_to_to_cancel(struct tcp_rack *rack,
461     uint32_t flex1, uint32_t flex2,
462     uint32_t flex3, uint32_t flex4,
463     uint32_t flex5, uint32_t flex6,
464     uint16_t flex7, uint8_t mod);
465 
466 static void
467 rack_log_pacing_delay_calc(struct tcp_rack *rack, uint32_t len, uint32_t slot,
468    uint64_t bw_est, uint64_t bw, uint64_t len_time, int method, int line,
469    struct rack_sendmap *rsm, uint8_t quality);
470 static struct rack_sendmap *
471 rack_find_high_nonack(struct tcp_rack *rack,
472     struct rack_sendmap *rsm);
473 static struct rack_sendmap *rack_find_lowest_rsm(struct tcp_rack *rack);
474 static void rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm);
475 static void rack_fini(struct tcpcb *tp, int32_t tcb_is_purged);
476 static int rack_get_sockopt(struct tcpcb *tp, struct sockopt *sopt);
477 static void
478 rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
479 			    tcp_seq th_ack, int line, uint8_t quality);
480 static void
481 rack_log_type_pacing_sizes(struct tcpcb *tp, struct tcp_rack *rack, uint32_t arg1, uint32_t arg2, uint32_t arg3, uint8_t frm);
482 
483 static uint32_t
484 rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss);
485 static int32_t rack_handoff_ok(struct tcpcb *tp);
486 static int32_t rack_init(struct tcpcb *tp, void **ptr);
487 static void rack_init_sysctls(void);
488 
489 static void
490 rack_log_ack(struct tcpcb *tp, struct tcpopt *to,
491     struct tcphdr *th, int entered_rec, int dup_ack_struck,
492     int *dsack_seen, int *sacks_seen);
493 static void
494 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
495     uint32_t seq_out, uint16_t th_flags, int32_t err, uint64_t ts,
496     struct rack_sendmap *hintrsm, uint16_t add_flags, struct mbuf *s_mb, uint32_t s_moff, int hw_tls, int segsiz);
497 
498 static uint64_t rack_get_gp_est(struct tcp_rack *rack);
499 
500 static void
501 rack_log_sack_passed(struct tcpcb *tp, struct tcp_rack *rack,
502     struct rack_sendmap *rsm);
503 static void rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm);
504 static int32_t rack_output(struct tcpcb *tp);
505 
506 static uint32_t
507 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack,
508     struct sackblk *sack, struct tcpopt *to, struct rack_sendmap **prsm,
509     uint32_t cts, int *no_extra, int *moved_two, uint32_t segsiz);
510 static void rack_post_recovery(struct tcpcb *tp, uint32_t th_seq);
511 static void rack_remxt_tmr(struct tcpcb *tp);
512 static int rack_set_sockopt(struct tcpcb *tp, struct sockopt *sopt);
513 static void rack_set_state(struct tcpcb *tp, struct tcp_rack *rack);
514 static int32_t rack_stopall(struct tcpcb *tp);
515 static void rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line);
516 static uint32_t
517 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
518     struct rack_sendmap *rsm, uint64_t ts, int32_t * lenp, uint16_t add_flag, int segsiz);
519 static void
520 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
521     struct rack_sendmap *rsm, uint64_t ts, uint16_t add_flag, int segsiz);
522 static int
523 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
524     struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack);
525 static int32_t tcp_addrack(module_t mod, int32_t type, void *data);
526 static int
527 rack_do_close_wait(struct mbuf *m, struct tcphdr *th,
528     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
529     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
530 static int
531 rack_do_closing(struct mbuf *m, struct tcphdr *th,
532     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
533     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
534 static int
535 rack_do_established(struct mbuf *m, struct tcphdr *th,
536     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
537     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
538 static int
539 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th,
540     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
541     int32_t tlen, uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos);
542 static int
543 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th,
544     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
545     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
546 static int
547 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th,
548     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
549     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
550 static int
551 rack_do_lastack(struct mbuf *m, struct tcphdr *th,
552     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
553     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
554 static int
555 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th,
556     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
557     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
558 static int
559 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th,
560     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
561     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
562 static void rack_chk_http_and_hybrid_on_out(struct tcp_rack *rack, tcp_seq seq, uint32_t len, uint64_t cts);
563 struct rack_sendmap *
564 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack,
565     uint32_t tsused);
566 static void tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt,
567     uint32_t len, uint32_t us_tim, int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt);
568 static void
569      tcp_rack_partialack(struct tcpcb *tp);
570 static int
571 rack_set_profile(struct tcp_rack *rack, int prof);
572 static void
573 rack_apply_deferred_options(struct tcp_rack *rack);
574 
575 int32_t rack_clear_counter=0;
576 
577 static uint64_t
578 rack_get_lt_bw(struct tcp_rack *rack)
579 {
580 	struct timeval tv;
581 	uint64_t tim, bytes;
582 
583 	tim = rack->r_ctl.lt_bw_time;
584 	bytes = rack->r_ctl.lt_bw_bytes;
585 	if (rack->lt_bw_up) {
586 		/* Include all the current bytes too */
587 		microuptime(&tv);
588 		bytes += (rack->rc_tp->snd_una - rack->r_ctl.lt_seq);
589 		tim += (tcp_tv_to_lusectick(&tv) - rack->r_ctl.lt_timemark);
590 	}
591 	if ((bytes != 0) && (tim != 0))
592 		return ((bytes * (uint64_t)1000000) / tim);
593 	else
594 		return (0);
595 }
596 
597 static void
598 rack_swap_beta_values(struct tcp_rack *rack, uint8_t flex8)
599 {
600 	struct sockopt sopt;
601 	struct cc_newreno_opts opt;
602 	struct newreno old;
603 	struct tcpcb *tp;
604 	int error, failed = 0;
605 
606 	tp = rack->rc_tp;
607 	if (tp->t_cc == NULL) {
608 		/* Tcb is leaving */
609 		return;
610 	}
611 	rack->rc_pacing_cc_set = 1;
612 	if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0) {
613 		/* Not new-reno we can't play games with beta! */
614 		failed = 1;
615 		goto out;
616 
617 	}
618 	if (CC_ALGO(tp)->ctl_output == NULL)  {
619 		/* Huh, not using new-reno so no swaps.? */
620 		failed = 2;
621 		goto out;
622 	}
623 	/* Get the current values out */
624 	sopt.sopt_valsize = sizeof(struct cc_newreno_opts);
625 	sopt.sopt_dir = SOPT_GET;
626 	opt.name = CC_NEWRENO_BETA;
627 	error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
628 	if (error)  {
629 		failed = 3;
630 		goto out;
631 	}
632 	old.beta = opt.val;
633 	opt.name = CC_NEWRENO_BETA_ECN;
634 	error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
635 	if (error)  {
636 		failed = 4;
637 		goto out;
638 	}
639 	old.beta_ecn = opt.val;
640 
641 	/* Now lets set in the values we have stored */
642 	sopt.sopt_dir = SOPT_SET;
643 	opt.name = CC_NEWRENO_BETA;
644 	opt.val = rack->r_ctl.rc_saved_beta.beta;
645 	error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
646 	if (error)  {
647 		failed = 5;
648 		goto out;
649 	}
650 	opt.name = CC_NEWRENO_BETA_ECN;
651 	opt.val = rack->r_ctl.rc_saved_beta.beta_ecn;
652 	error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
653 	if (error) {
654 		failed = 6;
655 		goto out;
656 	}
657 	/* Save off the values for restoral */
658 	memcpy(&rack->r_ctl.rc_saved_beta, &old, sizeof(struct newreno));
659 out:
660 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
661 		union tcp_log_stackspecific log;
662 		struct timeval tv;
663 		struct newreno *ptr;
664 
665 		ptr = ((struct newreno *)tp->t_ccv.cc_data);
666 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
667 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
668 		log.u_bbr.flex1 = ptr->beta;
669 		log.u_bbr.flex2 = ptr->beta_ecn;
670 		log.u_bbr.flex3 = ptr->newreno_flags;
671 		log.u_bbr.flex4 = rack->r_ctl.rc_saved_beta.beta;
672 		log.u_bbr.flex5 = rack->r_ctl.rc_saved_beta.beta_ecn;
673 		log.u_bbr.flex6 = failed;
674 		log.u_bbr.flex7 = rack->gp_ready;
675 		log.u_bbr.flex7 <<= 1;
676 		log.u_bbr.flex7 |= rack->use_fixed_rate;
677 		log.u_bbr.flex7 <<= 1;
678 		log.u_bbr.flex7 |= rack->rc_pacing_cc_set;
679 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
680 		log.u_bbr.flex8 = flex8;
681 		tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, error,
682 			       0, &log, false, NULL, NULL, 0, &tv);
683 	}
684 }
685 
686 static void
687 rack_set_cc_pacing(struct tcp_rack *rack)
688 {
689 	if (rack->rc_pacing_cc_set)
690 		return;
691 	/*
692 	 * Use the swap utility placing in 3 for flex8 to id a
693 	 * set of a new set of values.
694 	 */
695 	rack->rc_pacing_cc_set = 1;
696 	rack_swap_beta_values(rack, 3);
697 }
698 
699 static void
700 rack_undo_cc_pacing(struct tcp_rack *rack)
701 {
702 	if (rack->rc_pacing_cc_set == 0)
703 		return;
704 	/*
705 	 * Use the swap utility placing in 4 for flex8 to id a
706 	 * restoral of the old values.
707 	 */
708 	rack->rc_pacing_cc_set = 0;
709 	rack_swap_beta_values(rack, 4);
710 }
711 
712 static void
713 rack_log_gpset(struct tcp_rack *rack, uint32_t seq_end, uint32_t ack_end_t,
714 	       uint32_t send_end_t, int line, uint8_t mode, struct rack_sendmap *rsm)
715 {
716 	if (tcp_bblogging_on(rack->rc_tp)) {
717 		union tcp_log_stackspecific log;
718 		struct timeval tv;
719 
720 		memset(&log, 0, sizeof(log));
721 		log.u_bbr.flex1 = seq_end;
722 		log.u_bbr.flex2 = rack->rc_tp->gput_seq;
723 		log.u_bbr.flex3 = ack_end_t;
724 		log.u_bbr.flex4 = rack->rc_tp->gput_ts;
725 		log.u_bbr.flex5 = send_end_t;
726 		log.u_bbr.flex6 = rack->rc_tp->gput_ack;
727 		log.u_bbr.flex7 = mode;
728 		log.u_bbr.flex8 = 69;
729 		log.u_bbr.rttProp = rack->r_ctl.rc_gp_cumack_ts;
730 		log.u_bbr.delRate = rack->r_ctl.rc_gp_output_ts;
731 		log.u_bbr.pkts_out = line;
732 		log.u_bbr.cwnd_gain = rack->app_limited_needs_set;
733 		log.u_bbr.pkt_epoch = rack->r_ctl.rc_app_limited_cnt;
734 		if (rsm != NULL) {
735 			log.u_bbr.applimited = rsm->r_start;
736 			log.u_bbr.delivered = rsm->r_end;
737 			log.u_bbr.epoch = rsm->r_flags;
738 		}
739 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
740 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
741 		    &rack->rc_inp->inp_socket->so_rcv,
742 		    &rack->rc_inp->inp_socket->so_snd,
743 		    BBR_LOG_HPTSI_CALC, 0,
744 		    0, &log, false, &tv);
745 	}
746 }
747 
748 static int
749 sysctl_rack_clear(SYSCTL_HANDLER_ARGS)
750 {
751 	uint32_t stat;
752 	int32_t error;
753 
754 	error = SYSCTL_OUT(req, &rack_clear_counter, sizeof(uint32_t));
755 	if (error || req->newptr == NULL)
756 		return error;
757 
758 	error = SYSCTL_IN(req, &stat, sizeof(uint32_t));
759 	if (error)
760 		return (error);
761 	if (stat == 1) {
762 #ifdef INVARIANTS
763 		printf("Clearing RACK counters\n");
764 #endif
765 		counter_u64_zero(rack_tlp_tot);
766 		counter_u64_zero(rack_tlp_newdata);
767 		counter_u64_zero(rack_tlp_retran);
768 		counter_u64_zero(rack_tlp_retran_bytes);
769 		counter_u64_zero(rack_to_tot);
770 		counter_u64_zero(rack_saw_enobuf);
771 		counter_u64_zero(rack_saw_enobuf_hw);
772 		counter_u64_zero(rack_saw_enetunreach);
773 		counter_u64_zero(rack_persists_sends);
774 		counter_u64_zero(rack_total_bytes);
775 		counter_u64_zero(rack_persists_acks);
776 		counter_u64_zero(rack_persists_loss);
777 		counter_u64_zero(rack_persists_lost_ends);
778 #ifdef INVARIANTS
779 		counter_u64_zero(rack_adjust_map_bw);
780 #endif
781 		counter_u64_zero(rack_to_alloc_hard);
782 		counter_u64_zero(rack_to_alloc_emerg);
783 		counter_u64_zero(rack_sack_proc_all);
784 		counter_u64_zero(rack_fto_send);
785 		counter_u64_zero(rack_fto_rsm_send);
786 		counter_u64_zero(rack_extended_rfo);
787 		counter_u64_zero(rack_hw_pace_init_fail);
788 		counter_u64_zero(rack_hw_pace_lost);
789 		counter_u64_zero(rack_non_fto_send);
790 		counter_u64_zero(rack_nfto_resend);
791 		counter_u64_zero(rack_sack_proc_short);
792 		counter_u64_zero(rack_sack_proc_restart);
793 		counter_u64_zero(rack_to_alloc);
794 		counter_u64_zero(rack_to_alloc_limited);
795 		counter_u64_zero(rack_alloc_limited_conns);
796 		counter_u64_zero(rack_split_limited);
797 		counter_u64_zero(rack_rxt_clamps_cwnd);
798 		counter_u64_zero(rack_rxt_clamps_cwnd_uniq);
799 		counter_u64_zero(rack_multi_single_eq);
800 		counter_u64_zero(rack_proc_non_comp_ack);
801 		counter_u64_zero(rack_sack_attacks_detected);
802 		counter_u64_zero(rack_sack_attacks_reversed);
803 		counter_u64_zero(rack_sack_attacks_suspect);
804 		counter_u64_zero(rack_sack_used_next_merge);
805 		counter_u64_zero(rack_sack_used_prev_merge);
806 		counter_u64_zero(rack_sack_splits);
807 		counter_u64_zero(rack_sack_skipped_acked);
808 		counter_u64_zero(rack_ack_total);
809 		counter_u64_zero(rack_express_sack);
810 		counter_u64_zero(rack_sack_total);
811 		counter_u64_zero(rack_move_none);
812 		counter_u64_zero(rack_move_some);
813 		counter_u64_zero(rack_try_scwnd);
814 		counter_u64_zero(rack_collapsed_win);
815 		counter_u64_zero(rack_collapsed_win_rxt);
816 		counter_u64_zero(rack_collapsed_win_seen);
817 		counter_u64_zero(rack_collapsed_win_rxt_bytes);
818 	} else if (stat == 2) {
819 #ifdef INVARIANTS
820 		printf("Clearing RACK option array\n");
821 #endif
822 		COUNTER_ARRAY_ZERO(rack_opts_arry, RACK_OPTS_SIZE);
823 	} else if (stat == 3) {
824 		printf("Rack has no stats counters to clear (use 1 to clear all stats in sysctl node)\n");
825 	} else if (stat == 4) {
826 #ifdef INVARIANTS
827 		printf("Clearing RACK out size array\n");
828 #endif
829 		COUNTER_ARRAY_ZERO(rack_out_size, TCP_MSS_ACCT_SIZE);
830 	}
831 	rack_clear_counter = 0;
832 	return (0);
833 }
834 
835 static void
836 rack_init_sysctls(void)
837 {
838 	struct sysctl_oid *rack_counters;
839 	struct sysctl_oid *rack_attack;
840 	struct sysctl_oid *rack_pacing;
841 	struct sysctl_oid *rack_timely;
842 	struct sysctl_oid *rack_timers;
843 	struct sysctl_oid *rack_tlp;
844 	struct sysctl_oid *rack_misc;
845 	struct sysctl_oid *rack_features;
846 	struct sysctl_oid *rack_measure;
847 	struct sysctl_oid *rack_probertt;
848 	struct sysctl_oid *rack_hw_pacing;
849 
850 	rack_attack = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
851 	    SYSCTL_CHILDREN(rack_sysctl_root),
852 	    OID_AUTO,
853 	    "sack_attack",
854 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
855 	    "Rack Sack Attack Counters and Controls");
856 	rack_counters = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
857 	    SYSCTL_CHILDREN(rack_sysctl_root),
858 	    OID_AUTO,
859 	    "stats",
860 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
861 	    "Rack Counters");
862 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
863 	    SYSCTL_CHILDREN(rack_sysctl_root),
864 	    OID_AUTO, "rate_sample_method", CTLFLAG_RW,
865 	    &rack_rate_sample_method , USE_RTT_LOW,
866 	    "What method should we use for rate sampling 0=high, 1=low ");
867 	/* Probe rtt related controls */
868 	rack_probertt = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
869 	    SYSCTL_CHILDREN(rack_sysctl_root),
870 	    OID_AUTO,
871 	    "probertt",
872 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
873 	    "ProbeRTT related Controls");
874 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
875 	    SYSCTL_CHILDREN(rack_probertt),
876 	    OID_AUTO, "exit_per_hpb", CTLFLAG_RW,
877 	    &rack_atexit_prtt_hbp, 130,
878 	    "What percentage above goodput do we clamp CA/SS to at exit on high-BDP path 110%");
879 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
880 	    SYSCTL_CHILDREN(rack_probertt),
881 	    OID_AUTO, "exit_per_nonhpb", CTLFLAG_RW,
882 	    &rack_atexit_prtt, 130,
883 	    "What percentage above goodput do we clamp CA/SS to at exit on a non high-BDP path 100%");
884 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
885 	    SYSCTL_CHILDREN(rack_probertt),
886 	    OID_AUTO, "gp_per_mul", CTLFLAG_RW,
887 	    &rack_per_of_gp_probertt, 60,
888 	    "What percentage of goodput do we pace at in probertt");
889 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
890 	    SYSCTL_CHILDREN(rack_probertt),
891 	    OID_AUTO, "gp_per_reduce", CTLFLAG_RW,
892 	    &rack_per_of_gp_probertt_reduce, 10,
893 	    "What percentage of goodput do we reduce every gp_srtt");
894 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
895 	    SYSCTL_CHILDREN(rack_probertt),
896 	    OID_AUTO, "gp_per_low", CTLFLAG_RW,
897 	    &rack_per_of_gp_lowthresh, 40,
898 	    "What percentage of goodput do we allow the multiplier to fall to");
899 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
900 	    SYSCTL_CHILDREN(rack_probertt),
901 	    OID_AUTO, "time_between", CTLFLAG_RW,
902 	    & rack_time_between_probertt, 96000000,
903 	    "How many useconds between the lowest rtt falling must past before we enter probertt");
904 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
905 	    SYSCTL_CHILDREN(rack_probertt),
906 	    OID_AUTO, "safety", CTLFLAG_RW,
907 	    &rack_probe_rtt_safety_val, 2000000,
908 	    "If not zero, provides a maximum usecond that you can stay in probertt (2sec = 2000000)");
909 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
910 	    SYSCTL_CHILDREN(rack_probertt),
911 	    OID_AUTO, "sets_cwnd", CTLFLAG_RW,
912 	    &rack_probe_rtt_sets_cwnd, 0,
913 	    "Do we set the cwnd too (if always_lower is on)");
914 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
915 	    SYSCTL_CHILDREN(rack_probertt),
916 	    OID_AUTO, "maxdrainsrtts", CTLFLAG_RW,
917 	    &rack_max_drain_wait, 2,
918 	    "Maximum number of gp_srtt's to hold in drain waiting for flight to reach goal");
919 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
920 	    SYSCTL_CHILDREN(rack_probertt),
921 	    OID_AUTO, "mustdrainsrtts", CTLFLAG_RW,
922 	    &rack_must_drain, 1,
923 	    "We must drain this many gp_srtt's waiting for flight to reach goal");
924 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
925 	    SYSCTL_CHILDREN(rack_probertt),
926 	    OID_AUTO, "goal_use_min_entry", CTLFLAG_RW,
927 	    &rack_probertt_use_min_rtt_entry, 1,
928 	    "Should we use the min-rtt to calculate the goal rtt (else gp_srtt) at entry");
929 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
930 	    SYSCTL_CHILDREN(rack_probertt),
931 	    OID_AUTO, "goal_use_min_exit", CTLFLAG_RW,
932 	    &rack_probertt_use_min_rtt_exit, 0,
933 	    "How to set cwnd at exit, 0 - dynamic, 1 - use min-rtt, 2 - use curgprtt, 3 - entry gp-rtt");
934 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
935 	    SYSCTL_CHILDREN(rack_probertt),
936 	    OID_AUTO, "length_div", CTLFLAG_RW,
937 	    &rack_probertt_gpsrtt_cnt_div, 0,
938 	    "How many recent goodput srtt periods plus hold tim does probertt last (bottom of fraction)");
939 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
940 	    SYSCTL_CHILDREN(rack_probertt),
941 	    OID_AUTO, "length_mul", CTLFLAG_RW,
942 	    &rack_probertt_gpsrtt_cnt_mul, 0,
943 	    "How many recent goodput srtt periods plus hold tim does probertt last (top of fraction)");
944 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
945 	    SYSCTL_CHILDREN(rack_probertt),
946 	    OID_AUTO, "holdtim_at_target", CTLFLAG_RW,
947 	    &rack_min_probertt_hold, 200000,
948 	    "What is the minimum time we hold probertt at target");
949 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
950 	    SYSCTL_CHILDREN(rack_probertt),
951 	    OID_AUTO, "filter_life", CTLFLAG_RW,
952 	    &rack_probertt_filter_life, 10000000,
953 	    "What is the time for the filters life in useconds");
954 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
955 	    SYSCTL_CHILDREN(rack_probertt),
956 	    OID_AUTO, "lower_within", CTLFLAG_RW,
957 	    &rack_probertt_lower_within, 10,
958 	    "If the rtt goes lower within this percentage of the time, go into probe-rtt");
959 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
960 	    SYSCTL_CHILDREN(rack_probertt),
961 	    OID_AUTO, "must_move", CTLFLAG_RW,
962 	    &rack_min_rtt_movement, 250,
963 	    "How much is the minimum movement in rtt to count as a drop for probertt purposes");
964 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
965 	    SYSCTL_CHILDREN(rack_probertt),
966 	    OID_AUTO, "clear_is_cnts", CTLFLAG_RW,
967 	    &rack_probertt_clear_is, 1,
968 	    "Do we clear I/S counts on exiting probe-rtt");
969 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
970 	    SYSCTL_CHILDREN(rack_probertt),
971 	    OID_AUTO, "hbp_extra_drain", CTLFLAG_RW,
972 	    &rack_max_drain_hbp, 1,
973 	    "How many extra drain gpsrtt's do we get in highly buffered paths");
974 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
975 	    SYSCTL_CHILDREN(rack_probertt),
976 	    OID_AUTO, "hbp_threshold", CTLFLAG_RW,
977 	    &rack_hbp_thresh, 3,
978 	    "We are highly buffered if min_rtt_seen / max_rtt_seen > this-threshold");
979 	/* Pacing related sysctls */
980 	rack_pacing = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
981 	    SYSCTL_CHILDREN(rack_sysctl_root),
982 	    OID_AUTO,
983 	    "pacing",
984 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
985 	    "Pacing related Controls");
986 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
987 	    SYSCTL_CHILDREN(rack_pacing),
988 	    OID_AUTO, "fulldgpinrec", CTLFLAG_RW,
989 	    &rack_uses_full_dgp_in_rec, 1,
990 	    "Do we use all DGP features in recovery (fillcw, timely et.al.)?");
991 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
992 	    SYSCTL_CHILDREN(rack_pacing),
993 	    OID_AUTO, "fullbufdisc", CTLFLAG_RW,
994 	    &rack_full_buffer_discount, 10,
995 	    "What percentage b/w reduction over the GP estimate for a full buffer (default=0 off)?");
996 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
997 	    SYSCTL_CHILDREN(rack_pacing),
998 	    OID_AUTO, "fillcw", CTLFLAG_RW,
999 	    &rack_fill_cw_state, 0,
1000 	    "Enable fillcw on new connections (default=0 off)?");
1001 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1002 	    SYSCTL_CHILDREN(rack_pacing),
1003 	    OID_AUTO, "min_burst", CTLFLAG_RW,
1004 	    &rack_pacing_min_seg, 0,
1005 	    "What is the min burst size for pacing (0 disables)?");
1006 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1007 	    SYSCTL_CHILDREN(rack_pacing),
1008 	    OID_AUTO, "divisor", CTLFLAG_RW,
1009 	    &rack_default_pacing_divisor, 4,
1010 	    "What is the default divisor given to the rl code?");
1011 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1012 	    SYSCTL_CHILDREN(rack_pacing),
1013 	    OID_AUTO, "fillcw_max_mult", CTLFLAG_RW,
1014 	    &rack_bw_multipler, 2,
1015 	    "What is the multiplier of the current gp_est that fillcw can increase the b/w too?");
1016 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1017 	    SYSCTL_CHILDREN(rack_pacing),
1018 	    OID_AUTO, "max_pace_over", CTLFLAG_RW,
1019 	    &rack_max_per_above, 30,
1020 	    "What is the maximum allowable percentage that we can pace above (so 30 = 130% of our goal)");
1021 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1022 	    SYSCTL_CHILDREN(rack_pacing),
1023 	    OID_AUTO, "allow1mss", CTLFLAG_RW,
1024 	    &rack_pace_one_seg, 0,
1025 	    "Do we allow low b/w pacing of 1MSS instead of two (1.2Meg and less)?");
1026 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1027 	    SYSCTL_CHILDREN(rack_pacing),
1028 	    OID_AUTO, "limit_wsrtt", CTLFLAG_RW,
1029 	    &rack_limit_time_with_srtt, 0,
1030 	    "Do we limit pacing time based on srtt");
1031 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1032 	    SYSCTL_CHILDREN(rack_pacing),
1033 	    OID_AUTO, "init_win", CTLFLAG_RW,
1034 	    &rack_default_init_window, 0,
1035 	    "Do we have a rack initial window 0 = system default");
1036 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1037 	    SYSCTL_CHILDREN(rack_pacing),
1038 	    OID_AUTO, "gp_per_ss", CTLFLAG_RW,
1039 	    &rack_per_of_gp_ss, 250,
1040 	    "If non zero, what percentage of goodput to pace at in slow start");
1041 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1042 	    SYSCTL_CHILDREN(rack_pacing),
1043 	    OID_AUTO, "gp_per_ca", CTLFLAG_RW,
1044 	    &rack_per_of_gp_ca, 150,
1045 	    "If non zero, what percentage of goodput to pace at in congestion avoidance");
1046 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1047 	    SYSCTL_CHILDREN(rack_pacing),
1048 	    OID_AUTO, "gp_per_rec", CTLFLAG_RW,
1049 	    &rack_per_of_gp_rec, 200,
1050 	    "If non zero, what percentage of goodput to pace at in recovery");
1051 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1052 	    SYSCTL_CHILDREN(rack_pacing),
1053 	    OID_AUTO, "pace_max_seg", CTLFLAG_RW,
1054 	    &rack_hptsi_segments, 40,
1055 	    "What size is the max for TSO segments in pacing and burst mitigation");
1056 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1057 	    SYSCTL_CHILDREN(rack_pacing),
1058 	    OID_AUTO, "burst_reduces", CTLFLAG_RW,
1059 	    &rack_slot_reduction, 4,
1060 	    "When doing only burst mitigation what is the reduce divisor");
1061 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1062 	    SYSCTL_CHILDREN(rack_sysctl_root),
1063 	    OID_AUTO, "use_pacing", CTLFLAG_RW,
1064 	    &rack_pace_every_seg, 0,
1065 	    "If set we use pacing, if clear we use only the original burst mitigation");
1066 	SYSCTL_ADD_U64(&rack_sysctl_ctx,
1067 	    SYSCTL_CHILDREN(rack_pacing),
1068 	    OID_AUTO, "rate_cap", CTLFLAG_RW,
1069 	    &rack_bw_rate_cap, 0,
1070 	    "If set we apply this value to the absolute rate cap used by pacing");
1071 	SYSCTL_ADD_U8(&rack_sysctl_ctx,
1072 	    SYSCTL_CHILDREN(rack_sysctl_root),
1073 	    OID_AUTO, "req_measure_cnt", CTLFLAG_RW,
1074 	    &rack_req_measurements, 1,
1075 	    "If doing dynamic pacing, how many measurements must be in before we start pacing?");
1076 	/* Hardware pacing */
1077 	rack_hw_pacing = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1078 	    SYSCTL_CHILDREN(rack_sysctl_root),
1079 	    OID_AUTO,
1080 	    "hdwr_pacing",
1081 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1082 	    "Pacing related Controls");
1083 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1084 	    SYSCTL_CHILDREN(rack_hw_pacing),
1085 	    OID_AUTO, "rwnd_factor", CTLFLAG_RW,
1086 	    &rack_hw_rwnd_factor, 2,
1087 	    "How many times does snd_wnd need to be bigger than pace_max_seg so we will hold off and get more acks?");
1088 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1089 	    SYSCTL_CHILDREN(rack_hw_pacing),
1090 	    OID_AUTO, "precheck", CTLFLAG_RW,
1091 	    &rack_hw_check_queue, 0,
1092 	    "Do we always precheck the hdwr pacing queue to avoid ENOBUF's?");
1093 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1094 	    SYSCTL_CHILDREN(rack_hw_pacing),
1095 	    OID_AUTO, "pace_enobuf_mult", CTLFLAG_RW,
1096 	    &rack_enobuf_hw_boost_mult, 0,
1097 	    "By how many time_betweens should we boost the pacing time if we see a ENOBUFS?");
1098 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1099 	    SYSCTL_CHILDREN(rack_hw_pacing),
1100 	    OID_AUTO, "pace_enobuf_max", CTLFLAG_RW,
1101 	    &rack_enobuf_hw_max, 2,
1102 	    "What is the max boost the pacing time if we see a ENOBUFS?");
1103 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1104 	    SYSCTL_CHILDREN(rack_hw_pacing),
1105 	    OID_AUTO, "pace_enobuf_min", CTLFLAG_RW,
1106 	    &rack_enobuf_hw_min, 2,
1107 	    "What is the min boost the pacing time if we see a ENOBUFS?");
1108 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1109 	    SYSCTL_CHILDREN(rack_hw_pacing),
1110 	    OID_AUTO, "enable", CTLFLAG_RW,
1111 	    &rack_enable_hw_pacing, 0,
1112 	    "Should RACK attempt to use hw pacing?");
1113 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1114 	    SYSCTL_CHILDREN(rack_hw_pacing),
1115 	    OID_AUTO, "rate_cap", CTLFLAG_RW,
1116 	    &rack_hw_rate_caps, 0,
1117 	    "Does the highest hardware pacing rate cap the rate we will send at??");
1118 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1119 	    SYSCTL_CHILDREN(rack_hw_pacing),
1120 	    OID_AUTO, "uncap_per", CTLFLAG_RW,
1121 	    &rack_hw_rate_cap_per, 0,
1122 	    "If you go over b/w by this amount you will be uncapped (0 = never)");
1123 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1124 	    SYSCTL_CHILDREN(rack_hw_pacing),
1125 	    OID_AUTO, "rate_min", CTLFLAG_RW,
1126 	    &rack_hw_rate_min, 0,
1127 	    "Do we need a minimum estimate of this many bytes per second in order to engage hw pacing?");
1128 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1129 	    SYSCTL_CHILDREN(rack_hw_pacing),
1130 	    OID_AUTO, "rate_to_low", CTLFLAG_RW,
1131 	    &rack_hw_rate_to_low, 0,
1132 	    "If we fall below this rate, dis-engage hw pacing?");
1133 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1134 	    SYSCTL_CHILDREN(rack_hw_pacing),
1135 	    OID_AUTO, "up_only", CTLFLAG_RW,
1136 	    &rack_hw_up_only, 0,
1137 	    "Do we allow hw pacing to lower the rate selected?");
1138 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1139 	    SYSCTL_CHILDREN(rack_hw_pacing),
1140 	    OID_AUTO, "extra_mss_precise", CTLFLAG_RW,
1141 	    &rack_hw_pace_extra_slots, 0,
1142 	    "If the rates between software and hardware match precisely how many extra time_betweens do we get?");
1143 	rack_timely = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1144 	    SYSCTL_CHILDREN(rack_sysctl_root),
1145 	    OID_AUTO,
1146 	    "timely",
1147 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1148 	    "Rack Timely RTT Controls");
1149 	/* Timely based GP dynmics */
1150 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1151 	    SYSCTL_CHILDREN(rack_timely),
1152 	    OID_AUTO, "upper", CTLFLAG_RW,
1153 	    &rack_gp_per_bw_mul_up, 2,
1154 	    "Rack timely upper range for equal b/w (in percentage)");
1155 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1156 	    SYSCTL_CHILDREN(rack_timely),
1157 	    OID_AUTO, "lower", CTLFLAG_RW,
1158 	    &rack_gp_per_bw_mul_down, 4,
1159 	    "Rack timely lower range for equal b/w (in percentage)");
1160 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1161 	    SYSCTL_CHILDREN(rack_timely),
1162 	    OID_AUTO, "rtt_max_mul", CTLFLAG_RW,
1163 	    &rack_gp_rtt_maxmul, 3,
1164 	    "Rack timely multiplier of lowest rtt for rtt_max");
1165 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1166 	    SYSCTL_CHILDREN(rack_timely),
1167 	    OID_AUTO, "rtt_min_div", CTLFLAG_RW,
1168 	    &rack_gp_rtt_mindiv, 4,
1169 	    "Rack timely divisor used for rtt + (rtt * mul/divisor) for check for lower rtt");
1170 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1171 	    SYSCTL_CHILDREN(rack_timely),
1172 	    OID_AUTO, "rtt_min_mul", CTLFLAG_RW,
1173 	    &rack_gp_rtt_minmul, 1,
1174 	    "Rack timely multiplier used for rtt + (rtt * mul/divisor) for check for lower rtt");
1175 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1176 	    SYSCTL_CHILDREN(rack_timely),
1177 	    OID_AUTO, "decrease", CTLFLAG_RW,
1178 	    &rack_gp_decrease_per, 20,
1179 	    "Rack timely decrease percentage of our GP multiplication factor");
1180 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1181 	    SYSCTL_CHILDREN(rack_timely),
1182 	    OID_AUTO, "increase", CTLFLAG_RW,
1183 	    &rack_gp_increase_per, 2,
1184 	    "Rack timely increase perentage of our GP multiplication factor");
1185 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1186 	    SYSCTL_CHILDREN(rack_timely),
1187 	    OID_AUTO, "lowerbound", CTLFLAG_RW,
1188 	    &rack_per_lower_bound, 50,
1189 	    "Rack timely lowest percentage we allow GP multiplier to fall to");
1190 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1191 	    SYSCTL_CHILDREN(rack_timely),
1192 	    OID_AUTO, "upperboundss", CTLFLAG_RW,
1193 	    &rack_per_upper_bound_ss, 0,
1194 	    "Rack timely highest percentage we allow GP multiplier in SS to raise to (0 is no upperbound)");
1195 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1196 	    SYSCTL_CHILDREN(rack_timely),
1197 	    OID_AUTO, "upperboundca", CTLFLAG_RW,
1198 	    &rack_per_upper_bound_ca, 0,
1199 	    "Rack timely highest percentage we allow GP multiplier to CA raise to (0 is no upperbound)");
1200 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1201 	    SYSCTL_CHILDREN(rack_timely),
1202 	    OID_AUTO, "dynamicgp", CTLFLAG_RW,
1203 	    &rack_do_dyn_mul, 0,
1204 	    "Rack timely do we enable dynmaic timely goodput by default");
1205 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1206 	    SYSCTL_CHILDREN(rack_timely),
1207 	    OID_AUTO, "no_rec_red", CTLFLAG_RW,
1208 	    &rack_gp_no_rec_chg, 1,
1209 	    "Rack timely do we prohibit the recovery multiplier from being lowered");
1210 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1211 	    SYSCTL_CHILDREN(rack_timely),
1212 	    OID_AUTO, "red_clear_cnt", CTLFLAG_RW,
1213 	    &rack_timely_dec_clear, 6,
1214 	    "Rack timely what threshold do we count to before another boost during b/w decent");
1215 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1216 	    SYSCTL_CHILDREN(rack_timely),
1217 	    OID_AUTO, "max_push_rise", CTLFLAG_RW,
1218 	    &rack_timely_max_push_rise, 3,
1219 	    "Rack timely how many times do we push up with b/w increase");
1220 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1221 	    SYSCTL_CHILDREN(rack_timely),
1222 	    OID_AUTO, "max_push_drop", CTLFLAG_RW,
1223 	    &rack_timely_max_push_drop, 3,
1224 	    "Rack timely how many times do we push back on b/w decent");
1225 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1226 	    SYSCTL_CHILDREN(rack_timely),
1227 	    OID_AUTO, "min_segs", CTLFLAG_RW,
1228 	    &rack_timely_min_segs, 4,
1229 	    "Rack timely when setting the cwnd what is the min num segments");
1230 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1231 	    SYSCTL_CHILDREN(rack_timely),
1232 	    OID_AUTO, "noback_max", CTLFLAG_RW,
1233 	    &rack_use_max_for_nobackoff, 0,
1234 	    "Rack timely when deciding if to backoff on a loss, do we use under max rtt else min");
1235 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1236 	    SYSCTL_CHILDREN(rack_timely),
1237 	    OID_AUTO, "interim_timely_only", CTLFLAG_RW,
1238 	    &rack_timely_int_timely_only, 0,
1239 	    "Rack timely when doing interim timely's do we only do timely (no b/w consideration)");
1240 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1241 	    SYSCTL_CHILDREN(rack_timely),
1242 	    OID_AUTO, "nonstop", CTLFLAG_RW,
1243 	    &rack_timely_no_stopping, 0,
1244 	    "Rack timely don't stop increase");
1245 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1246 	    SYSCTL_CHILDREN(rack_timely),
1247 	    OID_AUTO, "dec_raise_thresh", CTLFLAG_RW,
1248 	    &rack_down_raise_thresh, 100,
1249 	    "If the CA or SS is below this threshold raise on the first 3 b/w lowers (0=always)");
1250 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1251 	    SYSCTL_CHILDREN(rack_timely),
1252 	    OID_AUTO, "bottom_drag_segs", CTLFLAG_RW,
1253 	    &rack_req_segs, 1,
1254 	    "Bottom dragging if not these many segments outstanding and room");
1255 
1256 	/* TLP and Rack related parameters */
1257 	rack_tlp = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1258 	    SYSCTL_CHILDREN(rack_sysctl_root),
1259 	    OID_AUTO,
1260 	    "tlp",
1261 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1262 	    "TLP and Rack related Controls");
1263 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1264 	    SYSCTL_CHILDREN(rack_tlp),
1265 	    OID_AUTO, "use_rrr", CTLFLAG_RW,
1266 	    &use_rack_rr, 1,
1267 	    "Do we use Rack Rapid Recovery");
1268 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1269 	    SYSCTL_CHILDREN(rack_tlp),
1270 	    OID_AUTO, "post_rec_labc", CTLFLAG_RW,
1271 	    &rack_max_abc_post_recovery, 2,
1272 	    "Since we do early recovery, do we override the l_abc to a value, if so what?");
1273 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1274 	    SYSCTL_CHILDREN(rack_tlp),
1275 	    OID_AUTO, "nonrxt_use_cr", CTLFLAG_RW,
1276 	    &rack_non_rxt_use_cr, 0,
1277 	    "Do we use ss/ca rate if in recovery we are transmitting a new data chunk");
1278 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1279 	    SYSCTL_CHILDREN(rack_tlp),
1280 	    OID_AUTO, "tlpmethod", CTLFLAG_RW,
1281 	    &rack_tlp_threshold_use, TLP_USE_TWO_ONE,
1282 	    "What method do we do for TLP time calc 0=no-de-ack-comp, 1=ID, 2=2.1, 3=2.2");
1283 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1284 	    SYSCTL_CHILDREN(rack_tlp),
1285 	    OID_AUTO, "limit", CTLFLAG_RW,
1286 	    &rack_tlp_limit, 2,
1287 	    "How many TLP's can be sent without sending new data");
1288 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1289 	    SYSCTL_CHILDREN(rack_tlp),
1290 	    OID_AUTO, "use_greater", CTLFLAG_RW,
1291 	    &rack_tlp_use_greater, 1,
1292 	    "Should we use the rack_rtt time if its greater than srtt");
1293 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1294 	    SYSCTL_CHILDREN(rack_tlp),
1295 	    OID_AUTO, "tlpminto", CTLFLAG_RW,
1296 	    &rack_tlp_min, 10000,
1297 	    "TLP minimum timeout per the specification (in microseconds)");
1298 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1299 	    SYSCTL_CHILDREN(rack_tlp),
1300 	    OID_AUTO, "send_oldest", CTLFLAG_RW,
1301 	    &rack_always_send_oldest, 0,
1302 	    "Should we always send the oldest TLP and RACK-TLP");
1303 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1304 	    SYSCTL_CHILDREN(rack_tlp),
1305 	    OID_AUTO, "rack_tlimit", CTLFLAG_RW,
1306 	    &rack_limited_retran, 0,
1307 	    "How many times can a rack timeout drive out sends");
1308 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1309 	    SYSCTL_CHILDREN(rack_tlp),
1310 	    OID_AUTO, "tlp_cwnd_flag", CTLFLAG_RW,
1311 	    &rack_lower_cwnd_at_tlp, 0,
1312 	    "When a TLP completes a retran should we enter recovery");
1313 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1314 	    SYSCTL_CHILDREN(rack_tlp),
1315 	    OID_AUTO, "reorder_thresh", CTLFLAG_RW,
1316 	    &rack_reorder_thresh, 2,
1317 	    "What factor for rack will be added when seeing reordering (shift right)");
1318 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1319 	    SYSCTL_CHILDREN(rack_tlp),
1320 	    OID_AUTO, "rtt_tlp_thresh", CTLFLAG_RW,
1321 	    &rack_tlp_thresh, 1,
1322 	    "What divisor for TLP rtt/retran will be added (1=rtt, 2=1/2 rtt etc)");
1323 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1324 	    SYSCTL_CHILDREN(rack_tlp),
1325 	    OID_AUTO, "reorder_fade", CTLFLAG_RW,
1326 	    &rack_reorder_fade, 60000000,
1327 	    "Does reorder detection fade, if so how many microseconds (0 means never)");
1328 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1329 	    SYSCTL_CHILDREN(rack_tlp),
1330 	    OID_AUTO, "pktdelay", CTLFLAG_RW,
1331 	    &rack_pkt_delay, 1000,
1332 	    "Extra RACK time (in microseconds) besides reordering thresh");
1333 
1334 	/* Timer related controls */
1335 	rack_timers = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1336 	    SYSCTL_CHILDREN(rack_sysctl_root),
1337 	    OID_AUTO,
1338 	    "timers",
1339 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1340 	    "Timer related controls");
1341 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1342 	    SYSCTL_CHILDREN(rack_timers),
1343 	    OID_AUTO, "persmin", CTLFLAG_RW,
1344 	    &rack_persist_min, 250000,
1345 	    "What is the minimum time in microseconds between persists");
1346 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1347 	    SYSCTL_CHILDREN(rack_timers),
1348 	    OID_AUTO, "persmax", CTLFLAG_RW,
1349 	    &rack_persist_max, 2000000,
1350 	    "What is the largest delay in microseconds between persists");
1351 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1352 	    SYSCTL_CHILDREN(rack_timers),
1353 	    OID_AUTO, "delayed_ack", CTLFLAG_RW,
1354 	    &rack_delayed_ack_time, 40000,
1355 	    "Delayed ack time (40ms in microseconds)");
1356 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1357 	    SYSCTL_CHILDREN(rack_timers),
1358 	    OID_AUTO, "minrto", CTLFLAG_RW,
1359 	    &rack_rto_min, 30000,
1360 	    "Minimum RTO in microseconds -- set with caution below 1000 due to TLP");
1361 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1362 	    SYSCTL_CHILDREN(rack_timers),
1363 	    OID_AUTO, "maxrto", CTLFLAG_RW,
1364 	    &rack_rto_max, 4000000,
1365 	    "Maximum RTO in microseconds -- should be at least as large as min_rto");
1366 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1367 	    SYSCTL_CHILDREN(rack_timers),
1368 	    OID_AUTO, "minto", CTLFLAG_RW,
1369 	    &rack_min_to, 1000,
1370 	    "Minimum rack timeout in microseconds");
1371 	/* Measure controls */
1372 	rack_measure = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1373 	    SYSCTL_CHILDREN(rack_sysctl_root),
1374 	    OID_AUTO,
1375 	    "measure",
1376 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1377 	    "Measure related controls");
1378 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1379 	    SYSCTL_CHILDREN(rack_measure),
1380 	    OID_AUTO, "wma_divisor", CTLFLAG_RW,
1381 	    &rack_wma_divisor, 8,
1382 	    "When doing b/w calculation what is the  divisor for the WMA");
1383 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1384 	    SYSCTL_CHILDREN(rack_measure),
1385 	    OID_AUTO, "end_cwnd", CTLFLAG_RW,
1386 	    &rack_cwnd_block_ends_measure, 0,
1387 	    "Does a cwnd just-return end the measurement window (app limited)");
1388 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1389 	    SYSCTL_CHILDREN(rack_measure),
1390 	    OID_AUTO, "end_rwnd", CTLFLAG_RW,
1391 	    &rack_rwnd_block_ends_measure, 0,
1392 	    "Does an rwnd just-return end the measurement window (app limited -- not persists)");
1393 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1394 	    SYSCTL_CHILDREN(rack_measure),
1395 	    OID_AUTO, "min_target", CTLFLAG_RW,
1396 	    &rack_def_data_window, 20,
1397 	    "What is the minimum target window (in mss) for a GP measurements");
1398 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1399 	    SYSCTL_CHILDREN(rack_measure),
1400 	    OID_AUTO, "goal_bdp", CTLFLAG_RW,
1401 	    &rack_goal_bdp, 2,
1402 	    "What is the goal BDP to measure");
1403 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1404 	    SYSCTL_CHILDREN(rack_measure),
1405 	    OID_AUTO, "min_srtts", CTLFLAG_RW,
1406 	    &rack_min_srtts, 1,
1407 	    "What is the goal BDP to measure");
1408 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1409 	    SYSCTL_CHILDREN(rack_measure),
1410 	    OID_AUTO, "min_measure_tim", CTLFLAG_RW,
1411 	    &rack_min_measure_usec, 0,
1412 	    "What is the Minimum time time for a measurement if 0, this is off");
1413 	/* Features */
1414 	rack_features = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1415 	    SYSCTL_CHILDREN(rack_sysctl_root),
1416 	    OID_AUTO,
1417 	    "features",
1418 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1419 	    "Feature controls");
1420 	SYSCTL_ADD_U64(&rack_sysctl_ctx,
1421 	    SYSCTL_CHILDREN(rack_features),
1422 	    OID_AUTO, "rxt_clamp_thresh", CTLFLAG_RW,
1423 	    &rack_rxt_clamp_thresh, 0,
1424 	    "Bit encoded clamping setup bits CCCC CCCCC UUUU UULF PPPP PPPP PPPP PPPP");
1425 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1426 	    SYSCTL_CHILDREN(rack_features),
1427 	    OID_AUTO, "hybrid_set_maxseg", CTLFLAG_RW,
1428 	    &rack_hybrid_allow_set_maxseg, 0,
1429 	    "Should hybrid pacing allow the setmss command");
1430 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1431 	    SYSCTL_CHILDREN(rack_features),
1432 	    OID_AUTO, "cmpack", CTLFLAG_RW,
1433 	    &rack_use_cmp_acks, 1,
1434 	    "Should RACK have LRO send compressed acks");
1435 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1436 	    SYSCTL_CHILDREN(rack_features),
1437 	    OID_AUTO, "fsb", CTLFLAG_RW,
1438 	    &rack_use_fsb, 1,
1439 	    "Should RACK use the fast send block?");
1440 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1441 	    SYSCTL_CHILDREN(rack_features),
1442 	    OID_AUTO, "rfo", CTLFLAG_RW,
1443 	    &rack_use_rfo, 1,
1444 	    "Should RACK use rack_fast_output()?");
1445 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1446 	    SYSCTL_CHILDREN(rack_features),
1447 	    OID_AUTO, "rsmrfo", CTLFLAG_RW,
1448 	    &rack_use_rsm_rfo, 1,
1449 	    "Should RACK use rack_fast_rsm_output()?");
1450 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1451 	    SYSCTL_CHILDREN(rack_features),
1452 	    OID_AUTO, "non_paced_lro_queue", CTLFLAG_RW,
1453 	    &rack_enable_mqueue_for_nonpaced, 0,
1454 	    "Should RACK use mbuf queuing for non-paced connections");
1455 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1456 	    SYSCTL_CHILDREN(rack_features),
1457 	    OID_AUTO, "hystartplusplus", CTLFLAG_RW,
1458 	    &rack_do_hystart, 0,
1459 	    "Should RACK enable HyStart++ on connections?");
1460 	/* Misc rack controls */
1461 	rack_misc = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1462 	    SYSCTL_CHILDREN(rack_sysctl_root),
1463 	    OID_AUTO,
1464 	    "misc",
1465 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1466 	    "Misc related controls");
1467 #ifdef TCP_ACCOUNTING
1468 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1469 	    SYSCTL_CHILDREN(rack_misc),
1470 	    OID_AUTO, "tcp_acct", CTLFLAG_RW,
1471 	    &rack_tcp_accounting, 0,
1472 	    "Should we turn on TCP accounting for all rack sessions?");
1473 #endif
1474 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1475 	    SYSCTL_CHILDREN(rack_misc),
1476 	    OID_AUTO, "dnd", CTLFLAG_RW,
1477 	    &rack_dnd_default, 0,
1478 	    "Do not disturb default for rack_rrr = 3");
1479 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1480 	    SYSCTL_CHILDREN(rack_misc),
1481 	    OID_AUTO, "sad_seg_per", CTLFLAG_RW,
1482 	    &sad_seg_size_per, 800,
1483 	    "Percentage of segment size needed in a sack 800 = 80.0?");
1484 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1485 	    SYSCTL_CHILDREN(rack_misc),
1486 	    OID_AUTO, "rxt_controls", CTLFLAG_RW,
1487 	    &rack_rxt_controls, 0,
1488 	    "Retransmit sending size controls (valid  values 0, 1, 2 default=1)?");
1489 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1490 	    SYSCTL_CHILDREN(rack_misc),
1491 	    OID_AUTO, "rack_hibeta", CTLFLAG_RW,
1492 	    &rack_hibeta_setting, 0,
1493 	    "Do we ue a high beta (80 instead of 50)?");
1494 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1495 	    SYSCTL_CHILDREN(rack_misc),
1496 	    OID_AUTO, "apply_rtt_with_low_conf", CTLFLAG_RW,
1497 	    &rack_apply_rtt_with_reduced_conf, 0,
1498 	    "When a persist or keep-alive probe is not answered do we calculate rtt on subsequent answers?");
1499 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1500 	    SYSCTL_CHILDREN(rack_misc),
1501 	    OID_AUTO, "rack_dsack_ctl", CTLFLAG_RW,
1502 	    &rack_dsack_std_based, 3,
1503 	    "How do we process dsack with respect to rack timers, bit field, 3 is standards based?");
1504 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1505 	    SYSCTL_CHILDREN(rack_misc),
1506 	    OID_AUTO, "prr_addback_max", CTLFLAG_RW,
1507 	    &rack_prr_addbackmax, 2,
1508 	    "What is the maximum number of MSS we allow to be added back if prr can't send all its data?");
1509 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1510 	    SYSCTL_CHILDREN(rack_misc),
1511 	    OID_AUTO, "stats_gets_ms", CTLFLAG_RW,
1512 	    &rack_stats_gets_ms_rtt, 1,
1513 	    "What do we feed the stats framework (1 = ms_rtt, 0 = us_rtt, 2 = ms_rtt from hdwr, > 2 usec rtt from hdwr)?");
1514 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1515 	    SYSCTL_CHILDREN(rack_misc),
1516 	    OID_AUTO, "clientlowbuf", CTLFLAG_RW,
1517 	    &rack_client_low_buf, 0,
1518 	    "Client low buffer level (below this we are more aggressive in DGP exiting recovery (0 = off)?");
1519 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1520 	    SYSCTL_CHILDREN(rack_misc),
1521 	    OID_AUTO, "defprofile", CTLFLAG_RW,
1522 	    &rack_def_profile, 0,
1523 	    "Should RACK use a default profile (0=no, num == profile num)?");
1524 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1525 	    SYSCTL_CHILDREN(rack_misc),
1526 	    OID_AUTO, "shared_cwnd", CTLFLAG_RW,
1527 	    &rack_enable_shared_cwnd, 1,
1528 	    "Should RACK try to use the shared cwnd on connections where allowed");
1529 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1530 	    SYSCTL_CHILDREN(rack_misc),
1531 	    OID_AUTO, "limits_on_scwnd", CTLFLAG_RW,
1532 	    &rack_limits_scwnd, 1,
1533 	    "Should RACK place low end time limits on the shared cwnd feature");
1534 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1535 	    SYSCTL_CHILDREN(rack_misc),
1536 	    OID_AUTO, "no_prr", CTLFLAG_RW,
1537 	    &rack_disable_prr, 0,
1538 	    "Should RACK not use prr and only pace (must have pacing on)");
1539 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1540 	    SYSCTL_CHILDREN(rack_misc),
1541 	    OID_AUTO, "bb_verbose", CTLFLAG_RW,
1542 	    &rack_verbose_logging, 0,
1543 	    "Should RACK black box logging be verbose");
1544 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1545 	    SYSCTL_CHILDREN(rack_misc),
1546 	    OID_AUTO, "data_after_close", CTLFLAG_RW,
1547 	    &rack_ignore_data_after_close, 1,
1548 	    "Do we hold off sending a RST until all pending data is ack'd");
1549 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1550 	    SYSCTL_CHILDREN(rack_misc),
1551 	    OID_AUTO, "no_sack_needed", CTLFLAG_RW,
1552 	    &rack_sack_not_required, 1,
1553 	    "Do we allow rack to run on connections not supporting SACK");
1554 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1555 	    SYSCTL_CHILDREN(rack_misc),
1556 	    OID_AUTO, "prr_sendalot", CTLFLAG_RW,
1557 	    &rack_send_a_lot_in_prr, 1,
1558 	    "Send a lot in prr");
1559 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1560 	    SYSCTL_CHILDREN(rack_misc),
1561 	    OID_AUTO, "autoscale", CTLFLAG_RW,
1562 	    &rack_autosndbuf_inc, 20,
1563 	    "What percentage should rack scale up its snd buffer by?");
1564 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1565 	    SYSCTL_CHILDREN(rack_misc),
1566 	    OID_AUTO, "rnds_for_rxt_clamp", CTLFLAG_RW,
1567 	    &rack_rxt_min_rnds, 10,
1568 	    "Number of rounds needed between RTT clamps due to high loss rates");
1569 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1570 	    SYSCTL_CHILDREN(rack_misc),
1571 	    OID_AUTO, "rnds_for_unclamp", CTLFLAG_RW,
1572 	    &rack_unclamp_round_thresh, 100,
1573 	    "Number of rounds needed with no loss to unclamp");
1574 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1575 	    SYSCTL_CHILDREN(rack_misc),
1576 	    OID_AUTO, "rxt_threshs_for_unclamp", CTLFLAG_RW,
1577 	    &rack_unclamp_rxt_thresh, 5,
1578 	   "Percentage of retransmits we need to be under to unclamp (5 = .5 percent)\n");
1579 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1580 	    SYSCTL_CHILDREN(rack_misc),
1581 	    OID_AUTO, "clamp_ss_upper", CTLFLAG_RW,
1582 	    &rack_clamp_ss_upper, 110,
1583 	    "Clamp percentage ceiling in SS?");
1584 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1585 	    SYSCTL_CHILDREN(rack_misc),
1586 	    OID_AUTO, "clamp_ca_upper", CTLFLAG_RW,
1587 	    &rack_clamp_ca_upper, 110,
1588 	    "Clamp percentage ceiling in CA?");
1589 	/* Sack Attacker detection stuff */
1590 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1591 	    SYSCTL_CHILDREN(rack_attack),
1592 	    OID_AUTO, "merge_out", CTLFLAG_RW,
1593 	    &rack_merge_out_sacks_on_attack, 0,
1594 	    "Do we merge the sendmap when we decide we are being attacked?");
1595 
1596 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1597 	    SYSCTL_CHILDREN(rack_attack),
1598 	    OID_AUTO, "detect_highsackratio", CTLFLAG_RW,
1599 	    &rack_highest_sack_thresh_seen, 0,
1600 	    "Highest sack to ack ratio seen");
1601 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1602 	    SYSCTL_CHILDREN(rack_attack),
1603 	    OID_AUTO, "detect_highmoveratio", CTLFLAG_RW,
1604 	    &rack_highest_move_thresh_seen, 0,
1605 	    "Highest move to non-move ratio seen");
1606 	rack_ack_total = counter_u64_alloc(M_WAITOK);
1607 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1608 	    SYSCTL_CHILDREN(rack_attack),
1609 	    OID_AUTO, "acktotal", CTLFLAG_RD,
1610 	    &rack_ack_total,
1611 	    "Total number of Ack's");
1612 	rack_express_sack = counter_u64_alloc(M_WAITOK);
1613 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1614 	    SYSCTL_CHILDREN(rack_attack),
1615 	    OID_AUTO, "exp_sacktotal", CTLFLAG_RD,
1616 	    &rack_express_sack,
1617 	    "Total expresss number of Sack's");
1618 	rack_sack_total = counter_u64_alloc(M_WAITOK);
1619 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1620 	    SYSCTL_CHILDREN(rack_attack),
1621 	    OID_AUTO, "sacktotal", CTLFLAG_RD,
1622 	    &rack_sack_total,
1623 	    "Total number of SACKs");
1624 	rack_move_none = counter_u64_alloc(M_WAITOK);
1625 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1626 	    SYSCTL_CHILDREN(rack_attack),
1627 	    OID_AUTO, "move_none", CTLFLAG_RD,
1628 	    &rack_move_none,
1629 	    "Total number of SACK index reuse of positions under threshold");
1630 	rack_move_some = counter_u64_alloc(M_WAITOK);
1631 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1632 	    SYSCTL_CHILDREN(rack_attack),
1633 	    OID_AUTO, "move_some", CTLFLAG_RD,
1634 	    &rack_move_some,
1635 	    "Total number of SACK index reuse of positions over threshold");
1636 	rack_sack_attacks_detected = counter_u64_alloc(M_WAITOK);
1637 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1638 	    SYSCTL_CHILDREN(rack_attack),
1639 	    OID_AUTO, "attacks", CTLFLAG_RD,
1640 	    &rack_sack_attacks_detected,
1641 	    "Total number of SACK attackers that had sack disabled");
1642 	rack_sack_attacks_reversed = counter_u64_alloc(M_WAITOK);
1643 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1644 	    SYSCTL_CHILDREN(rack_attack),
1645 	    OID_AUTO, "reversed", CTLFLAG_RD,
1646 	    &rack_sack_attacks_reversed,
1647 	    "Total number of SACK attackers that were later determined false positive");
1648 	rack_sack_attacks_suspect = counter_u64_alloc(M_WAITOK);
1649 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1650 	    SYSCTL_CHILDREN(rack_attack),
1651 	    OID_AUTO, "suspect", CTLFLAG_RD,
1652 	    &rack_sack_attacks_suspect,
1653 	    "Total number of SACKs that triggered early detection");
1654 
1655 	rack_sack_used_next_merge = counter_u64_alloc(M_WAITOK);
1656 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1657 	    SYSCTL_CHILDREN(rack_attack),
1658 	    OID_AUTO, "nextmerge", CTLFLAG_RD,
1659 	    &rack_sack_used_next_merge,
1660 	    "Total number of times we used the next merge");
1661 	rack_sack_used_prev_merge = counter_u64_alloc(M_WAITOK);
1662 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1663 	    SYSCTL_CHILDREN(rack_attack),
1664 	    OID_AUTO, "prevmerge", CTLFLAG_RD,
1665 	    &rack_sack_used_prev_merge,
1666 	    "Total number of times we used the prev merge");
1667 	/* Counters */
1668 	rack_total_bytes = counter_u64_alloc(M_WAITOK);
1669 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1670 	    SYSCTL_CHILDREN(rack_counters),
1671 	    OID_AUTO, "totalbytes", CTLFLAG_RD,
1672 	    &rack_total_bytes,
1673 	    "Total number of bytes sent");
1674 	rack_fto_send = counter_u64_alloc(M_WAITOK);
1675 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1676 	    SYSCTL_CHILDREN(rack_counters),
1677 	    OID_AUTO, "fto_send", CTLFLAG_RD,
1678 	    &rack_fto_send, "Total number of rack_fast_output sends");
1679 	rack_fto_rsm_send = counter_u64_alloc(M_WAITOK);
1680 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1681 	    SYSCTL_CHILDREN(rack_counters),
1682 	    OID_AUTO, "fto_rsm_send", CTLFLAG_RD,
1683 	    &rack_fto_rsm_send, "Total number of rack_fast_rsm_output sends");
1684 	rack_nfto_resend = counter_u64_alloc(M_WAITOK);
1685 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1686 	    SYSCTL_CHILDREN(rack_counters),
1687 	    OID_AUTO, "nfto_resend", CTLFLAG_RD,
1688 	    &rack_nfto_resend, "Total number of rack_output retransmissions");
1689 	rack_non_fto_send = counter_u64_alloc(M_WAITOK);
1690 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1691 	    SYSCTL_CHILDREN(rack_counters),
1692 	    OID_AUTO, "nfto_send", CTLFLAG_RD,
1693 	    &rack_non_fto_send, "Total number of rack_output first sends");
1694 	rack_extended_rfo = counter_u64_alloc(M_WAITOK);
1695 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1696 	    SYSCTL_CHILDREN(rack_counters),
1697 	    OID_AUTO, "rfo_extended", CTLFLAG_RD,
1698 	    &rack_extended_rfo, "Total number of times we extended rfo");
1699 
1700 	rack_hw_pace_init_fail = counter_u64_alloc(M_WAITOK);
1701 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1702 	    SYSCTL_CHILDREN(rack_counters),
1703 	    OID_AUTO, "hwpace_init_fail", CTLFLAG_RD,
1704 	    &rack_hw_pace_init_fail, "Total number of times we failed to initialize hw pacing");
1705 	rack_hw_pace_lost = counter_u64_alloc(M_WAITOK);
1706 
1707 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1708 	    SYSCTL_CHILDREN(rack_counters),
1709 	    OID_AUTO, "hwpace_lost", CTLFLAG_RD,
1710 	    &rack_hw_pace_lost, "Total number of times we failed to initialize hw pacing");
1711 	rack_tlp_tot = counter_u64_alloc(M_WAITOK);
1712 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1713 	    SYSCTL_CHILDREN(rack_counters),
1714 	    OID_AUTO, "tlp_to_total", CTLFLAG_RD,
1715 	    &rack_tlp_tot,
1716 	    "Total number of tail loss probe expirations");
1717 	rack_tlp_newdata = counter_u64_alloc(M_WAITOK);
1718 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1719 	    SYSCTL_CHILDREN(rack_counters),
1720 	    OID_AUTO, "tlp_new", CTLFLAG_RD,
1721 	    &rack_tlp_newdata,
1722 	    "Total number of tail loss probe sending new data");
1723 	rack_tlp_retran = counter_u64_alloc(M_WAITOK);
1724 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1725 	    SYSCTL_CHILDREN(rack_counters),
1726 	    OID_AUTO, "tlp_retran", CTLFLAG_RD,
1727 	    &rack_tlp_retran,
1728 	    "Total number of tail loss probe sending retransmitted data");
1729 	rack_tlp_retran_bytes = counter_u64_alloc(M_WAITOK);
1730 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1731 	    SYSCTL_CHILDREN(rack_counters),
1732 	    OID_AUTO, "tlp_retran_bytes", CTLFLAG_RD,
1733 	    &rack_tlp_retran_bytes,
1734 	    "Total bytes of tail loss probe sending retransmitted data");
1735 	rack_to_tot = counter_u64_alloc(M_WAITOK);
1736 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1737 	    SYSCTL_CHILDREN(rack_counters),
1738 	    OID_AUTO, "rack_to_tot", CTLFLAG_RD,
1739 	    &rack_to_tot,
1740 	    "Total number of times the rack to expired");
1741 	rack_saw_enobuf = counter_u64_alloc(M_WAITOK);
1742 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1743 	    SYSCTL_CHILDREN(rack_counters),
1744 	    OID_AUTO, "saw_enobufs", CTLFLAG_RD,
1745 	    &rack_saw_enobuf,
1746 	    "Total number of times a sends returned enobuf for non-hdwr paced connections");
1747 	rack_saw_enobuf_hw = counter_u64_alloc(M_WAITOK);
1748 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1749 	    SYSCTL_CHILDREN(rack_counters),
1750 	    OID_AUTO, "saw_enobufs_hw", CTLFLAG_RD,
1751 	    &rack_saw_enobuf_hw,
1752 	    "Total number of times a send returned enobuf for hdwr paced connections");
1753 	rack_saw_enetunreach = counter_u64_alloc(M_WAITOK);
1754 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1755 	    SYSCTL_CHILDREN(rack_counters),
1756 	    OID_AUTO, "saw_enetunreach", CTLFLAG_RD,
1757 	    &rack_saw_enetunreach,
1758 	    "Total number of times a send received a enetunreachable");
1759 	rack_hot_alloc = counter_u64_alloc(M_WAITOK);
1760 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1761 	    SYSCTL_CHILDREN(rack_counters),
1762 	    OID_AUTO, "alloc_hot", CTLFLAG_RD,
1763 	    &rack_hot_alloc,
1764 	    "Total allocations from the top of our list");
1765 	rack_to_alloc = counter_u64_alloc(M_WAITOK);
1766 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1767 	    SYSCTL_CHILDREN(rack_counters),
1768 	    OID_AUTO, "allocs", CTLFLAG_RD,
1769 	    &rack_to_alloc,
1770 	    "Total allocations of tracking structures");
1771 	rack_to_alloc_hard = counter_u64_alloc(M_WAITOK);
1772 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1773 	    SYSCTL_CHILDREN(rack_counters),
1774 	    OID_AUTO, "allochard", CTLFLAG_RD,
1775 	    &rack_to_alloc_hard,
1776 	    "Total allocations done with sleeping the hard way");
1777 	rack_to_alloc_emerg = counter_u64_alloc(M_WAITOK);
1778 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1779 	    SYSCTL_CHILDREN(rack_counters),
1780 	    OID_AUTO, "allocemerg", CTLFLAG_RD,
1781 	    &rack_to_alloc_emerg,
1782 	    "Total allocations done from emergency cache");
1783 	rack_to_alloc_limited = counter_u64_alloc(M_WAITOK);
1784 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1785 	    SYSCTL_CHILDREN(rack_counters),
1786 	    OID_AUTO, "alloc_limited", CTLFLAG_RD,
1787 	    &rack_to_alloc_limited,
1788 	    "Total allocations dropped due to limit");
1789 	rack_alloc_limited_conns = counter_u64_alloc(M_WAITOK);
1790 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1791 	    SYSCTL_CHILDREN(rack_counters),
1792 	    OID_AUTO, "alloc_limited_conns", CTLFLAG_RD,
1793 	    &rack_alloc_limited_conns,
1794 	    "Connections with allocations dropped due to limit");
1795 	rack_split_limited = counter_u64_alloc(M_WAITOK);
1796 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1797 	    SYSCTL_CHILDREN(rack_counters),
1798 	    OID_AUTO, "split_limited", CTLFLAG_RD,
1799 	    &rack_split_limited,
1800 	    "Split allocations dropped due to limit");
1801 	rack_rxt_clamps_cwnd = counter_u64_alloc(M_WAITOK);
1802 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1803 	    SYSCTL_CHILDREN(rack_counters),
1804 	    OID_AUTO, "rxt_clamps_cwnd", CTLFLAG_RD,
1805 	    &rack_rxt_clamps_cwnd,
1806 	    "Number of times that excessive rxt clamped the cwnd down");
1807 	rack_rxt_clamps_cwnd_uniq = counter_u64_alloc(M_WAITOK);
1808 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1809 	    SYSCTL_CHILDREN(rack_counters),
1810 	    OID_AUTO, "rxt_clamps_cwnd_uniq", CTLFLAG_RD,
1811 	    &rack_rxt_clamps_cwnd_uniq,
1812 	    "Number of connections that have had excessive rxt clamped the cwnd down");
1813 	rack_persists_sends = counter_u64_alloc(M_WAITOK);
1814 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1815 	    SYSCTL_CHILDREN(rack_counters),
1816 	    OID_AUTO, "persist_sends", CTLFLAG_RD,
1817 	    &rack_persists_sends,
1818 	    "Number of times we sent a persist probe");
1819 	rack_persists_acks = counter_u64_alloc(M_WAITOK);
1820 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1821 	    SYSCTL_CHILDREN(rack_counters),
1822 	    OID_AUTO, "persist_acks", CTLFLAG_RD,
1823 	    &rack_persists_acks,
1824 	    "Number of times a persist probe was acked");
1825 	rack_persists_loss = counter_u64_alloc(M_WAITOK);
1826 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1827 	    SYSCTL_CHILDREN(rack_counters),
1828 	    OID_AUTO, "persist_loss", CTLFLAG_RD,
1829 	    &rack_persists_loss,
1830 	    "Number of times we detected a lost persist probe (no ack)");
1831 	rack_persists_lost_ends = counter_u64_alloc(M_WAITOK);
1832 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1833 	    SYSCTL_CHILDREN(rack_counters),
1834 	    OID_AUTO, "persist_loss_ends", CTLFLAG_RD,
1835 	    &rack_persists_lost_ends,
1836 	    "Number of lost persist probe (no ack) that the run ended with a PERSIST abort");
1837 #ifdef INVARIANTS
1838 	rack_adjust_map_bw = counter_u64_alloc(M_WAITOK);
1839 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1840 	    SYSCTL_CHILDREN(rack_counters),
1841 	    OID_AUTO, "map_adjust_req", CTLFLAG_RD,
1842 	    &rack_adjust_map_bw,
1843 	    "Number of times we hit the case where the sb went up and down on a sendmap entry");
1844 #endif
1845 	rack_multi_single_eq = counter_u64_alloc(M_WAITOK);
1846 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1847 	    SYSCTL_CHILDREN(rack_counters),
1848 	    OID_AUTO, "cmp_ack_equiv", CTLFLAG_RD,
1849 	    &rack_multi_single_eq,
1850 	    "Number of compressed acks total represented");
1851 	rack_proc_non_comp_ack = counter_u64_alloc(M_WAITOK);
1852 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1853 	    SYSCTL_CHILDREN(rack_counters),
1854 	    OID_AUTO, "cmp_ack_not", CTLFLAG_RD,
1855 	    &rack_proc_non_comp_ack,
1856 	    "Number of non compresseds acks that we processed");
1857 
1858 
1859 	rack_sack_proc_all = counter_u64_alloc(M_WAITOK);
1860 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1861 	    SYSCTL_CHILDREN(rack_counters),
1862 	    OID_AUTO, "sack_long", CTLFLAG_RD,
1863 	    &rack_sack_proc_all,
1864 	    "Total times we had to walk whole list for sack processing");
1865 	rack_sack_proc_restart = counter_u64_alloc(M_WAITOK);
1866 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1867 	    SYSCTL_CHILDREN(rack_counters),
1868 	    OID_AUTO, "sack_restart", CTLFLAG_RD,
1869 	    &rack_sack_proc_restart,
1870 	    "Total times we had to walk whole list due to a restart");
1871 	rack_sack_proc_short = counter_u64_alloc(M_WAITOK);
1872 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1873 	    SYSCTL_CHILDREN(rack_counters),
1874 	    OID_AUTO, "sack_short", CTLFLAG_RD,
1875 	    &rack_sack_proc_short,
1876 	    "Total times we took shortcut for sack processing");
1877 	rack_sack_skipped_acked = counter_u64_alloc(M_WAITOK);
1878 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1879 	    SYSCTL_CHILDREN(rack_attack),
1880 	    OID_AUTO, "skipacked", CTLFLAG_RD,
1881 	    &rack_sack_skipped_acked,
1882 	    "Total number of times we skipped previously sacked");
1883 	rack_sack_splits = counter_u64_alloc(M_WAITOK);
1884 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1885 	    SYSCTL_CHILDREN(rack_attack),
1886 	    OID_AUTO, "ofsplit", CTLFLAG_RD,
1887 	    &rack_sack_splits,
1888 	    "Total number of times we did the old fashion tree split");
1889 	rack_input_idle_reduces = counter_u64_alloc(M_WAITOK);
1890 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1891 	    SYSCTL_CHILDREN(rack_counters),
1892 	    OID_AUTO, "idle_reduce_oninput", CTLFLAG_RD,
1893 	    &rack_input_idle_reduces,
1894 	    "Total number of idle reductions on input");
1895 	rack_collapsed_win_seen = counter_u64_alloc(M_WAITOK);
1896 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1897 	    SYSCTL_CHILDREN(rack_counters),
1898 	    OID_AUTO, "collapsed_win_seen", CTLFLAG_RD,
1899 	    &rack_collapsed_win_seen,
1900 	    "Total number of collapsed window events seen (where our window shrinks)");
1901 
1902 	rack_collapsed_win = counter_u64_alloc(M_WAITOK);
1903 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1904 	    SYSCTL_CHILDREN(rack_counters),
1905 	    OID_AUTO, "collapsed_win", CTLFLAG_RD,
1906 	    &rack_collapsed_win,
1907 	    "Total number of collapsed window events where we mark packets");
1908 	rack_collapsed_win_rxt = counter_u64_alloc(M_WAITOK);
1909 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1910 	    SYSCTL_CHILDREN(rack_counters),
1911 	    OID_AUTO, "collapsed_win_rxt", CTLFLAG_RD,
1912 	    &rack_collapsed_win_rxt,
1913 	    "Total number of packets that were retransmitted");
1914 	rack_collapsed_win_rxt_bytes = counter_u64_alloc(M_WAITOK);
1915 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1916 	    SYSCTL_CHILDREN(rack_counters),
1917 	    OID_AUTO, "collapsed_win_bytes", CTLFLAG_RD,
1918 	    &rack_collapsed_win_rxt_bytes,
1919 	    "Total number of bytes that were retransmitted");
1920 	rack_try_scwnd = counter_u64_alloc(M_WAITOK);
1921 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1922 	    SYSCTL_CHILDREN(rack_counters),
1923 	    OID_AUTO, "tried_scwnd", CTLFLAG_RD,
1924 	    &rack_try_scwnd,
1925 	    "Total number of scwnd attempts");
1926 	COUNTER_ARRAY_ALLOC(rack_out_size, TCP_MSS_ACCT_SIZE, M_WAITOK);
1927 	SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
1928 	    OID_AUTO, "outsize", CTLFLAG_RD,
1929 	    rack_out_size, TCP_MSS_ACCT_SIZE, "MSS send sizes");
1930 	COUNTER_ARRAY_ALLOC(rack_opts_arry, RACK_OPTS_SIZE, M_WAITOK);
1931 	SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
1932 	    OID_AUTO, "opts", CTLFLAG_RD,
1933 	    rack_opts_arry, RACK_OPTS_SIZE, "RACK Option Stats");
1934 	SYSCTL_ADD_PROC(&rack_sysctl_ctx,
1935 	    SYSCTL_CHILDREN(rack_sysctl_root),
1936 	    OID_AUTO, "clear", CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE,
1937 	    &rack_clear_counter, 0, sysctl_rack_clear, "IU", "Clear counters");
1938 }
1939 
1940 static uint32_t
1941 rc_init_window(struct tcp_rack *rack)
1942 {
1943 	uint32_t win;
1944 
1945 	if (rack->rc_init_win == 0) {
1946 		/*
1947 		 * Nothing set by the user, use the system stack
1948 		 * default.
1949 		 */
1950 		return (tcp_compute_initwnd(tcp_maxseg(rack->rc_tp)));
1951 	}
1952 	win = ctf_fixed_maxseg(rack->rc_tp) * rack->rc_init_win;
1953 	return (win);
1954 }
1955 
1956 static uint64_t
1957 rack_get_fixed_pacing_bw(struct tcp_rack *rack)
1958 {
1959 	if (IN_FASTRECOVERY(rack->rc_tp->t_flags))
1960 		return (rack->r_ctl.rc_fixed_pacing_rate_rec);
1961 	else if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
1962 		return (rack->r_ctl.rc_fixed_pacing_rate_ss);
1963 	else
1964 		return (rack->r_ctl.rc_fixed_pacing_rate_ca);
1965 }
1966 
1967 static void
1968 rack_log_hybrid_bw(struct tcp_rack *rack, uint32_t seq, uint64_t cbw, uint64_t tim,
1969 	uint64_t data, uint8_t mod, uint16_t aux,
1970 	struct http_sendfile_track *cur)
1971 {
1972 #ifdef TCP_REQUEST_TRK
1973 	int do_log = 0;
1974 
1975 	/*
1976 	 * The rate cap one is noisy and only should come out when normal BB logging
1977 	 * is enabled, the other logs (not RATE_CAP and NOT CAP_CALC) only come out
1978 	 * once per chunk and make up the BBpoint that can be turned on by the client.
1979 	 */
1980 	if ((mod == HYBRID_LOG_RATE_CAP) || (mod == HYBRID_LOG_CAP_CALC)) {
1981 		if (rack_verbose_logging != 0)
1982 			do_log = tcp_bblogging_on(rack->rc_tp);
1983 		else
1984 			do_log = 0;
1985 	} else
1986 		do_log = tcp_bblogging_point_on(rack->rc_tp, TCP_BBPOINT_REQ_LEVEL_LOGGING);
1987 
1988 	if (do_log) {
1989 		union tcp_log_stackspecific log;
1990 		struct timeval tv;
1991 		uint64_t lt_bw;
1992 
1993 		/* Convert our ms to a microsecond */
1994 		memset(&log, 0, sizeof(log));
1995 
1996 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
1997 		log.u_bbr.rttProp = tim;
1998 		log.u_bbr.bw_inuse = cbw;
1999 		log.u_bbr.delRate = rack_get_gp_est(rack);
2000 		lt_bw = rack_get_lt_bw(rack);
2001 		log.u_bbr.flex1 = seq;
2002 		log.u_bbr.pacing_gain = aux;
2003 		/* lt_bw = < flex3 | flex2 > */
2004 		log.u_bbr.flex2 = (uint32_t)(lt_bw & 0x00000000ffffffff);
2005 		log.u_bbr.flex3 = (uint32_t)((lt_bw >> 32) & 0x00000000ffffffff);
2006 		/* Record the last obtained us rtt in inflight */
2007 		if (cur == NULL) {
2008 			/* Make sure we are looking at the right log if an overide comes in */
2009 			cur = rack->r_ctl.rc_last_sft;
2010 		}
2011 		if (rack->r_ctl.rack_rs.rs_flags != RACK_RTT_EMPTY)
2012 			log.u_bbr.inflight = rack->r_ctl.rack_rs.rs_us_rtt;
2013 		else {
2014 			/* Use the last known rtt i.e. the rack-rtt */
2015 			log.u_bbr.inflight = rack->rc_rack_rtt;
2016 		}
2017 		if (cur != NULL) {
2018 			uint64_t off;
2019 
2020 			log.u_bbr.cur_del_rate = cur->deadline;
2021 			if ((mod == HYBRID_LOG_RATE_CAP) || (mod == HYBRID_LOG_CAP_CALC)) {
2022 				/* start = < lost | pkt_epoch > */
2023 				log.u_bbr.pkt_epoch = (uint32_t)(cur->start & 0x00000000ffffffff);
2024 				log.u_bbr.lost = (uint32_t)((cur->start >> 32) & 0x00000000ffffffff);
2025 				log.u_bbr.flex6 = cur->start_seq;
2026 				log.u_bbr.pkts_out = cur->end_seq;
2027 			} else {
2028 				/* start = < lost | pkt_epoch > */
2029 				log.u_bbr.pkt_epoch = (uint32_t)(cur->start & 0x00000000ffffffff);
2030 				log.u_bbr.lost = (uint32_t)((cur->start >> 32) & 0x00000000ffffffff);
2031 				/* end = < pkts_out | flex6 > */
2032 				log.u_bbr.flex6 = (uint32_t)(cur->end & 0x00000000ffffffff);
2033 				log.u_bbr.pkts_out = (uint32_t)((cur->end >> 32) & 0x00000000ffffffff);
2034 			}
2035 			/* first_send = <lt_epoch | epoch> */
2036 			log.u_bbr.epoch = (uint32_t)(cur->first_send & 0x00000000ffffffff);
2037 			log.u_bbr.lt_epoch = (uint32_t)((cur->first_send >> 32) & 0x00000000ffffffff);
2038 			/* localtime = <delivered | applimited>*/
2039 			log.u_bbr.applimited = (uint32_t)(cur->localtime & 0x00000000ffffffff);
2040 			log.u_bbr.delivered = (uint32_t)((cur->localtime >> 32) & 0x00000000ffffffff);
2041 			off = (uint64_t)(cur) - (uint64_t)(&rack->rc_tp->t_http_info[0]);
2042 			log.u_bbr.bbr_substate = (uint8_t)(off / sizeof(struct http_sendfile_track));
2043 			log.u_bbr.flex4 = (uint32_t)(rack->rc_tp->t_sndbytes - cur->sent_at_fs);
2044 			log.u_bbr.flex5 = (uint32_t)(rack->rc_tp->t_snd_rxt_bytes - cur->rxt_at_fs);
2045 			log.u_bbr.flex7 = (uint16_t)cur->hybrid_flags;
2046 		} else {
2047 			log.u_bbr.flex7 = 0xffff;
2048 			log.u_bbr.cur_del_rate = 0xffffffffffffffff;
2049 		}
2050 		/*
2051 		 * Compose bbr_state to be a bit wise 0000ADHF
2052 		 * where A is the always_pace flag
2053 		 * where D is the dgp_on flag
2054 		 * where H is the hybrid_mode on flag
2055 		 * where F is the use_fixed_rate flag.
2056 		 */
2057 		log.u_bbr.bbr_state = rack->rc_always_pace;
2058 		log.u_bbr.bbr_state <<= 1;
2059 		log.u_bbr.bbr_state |= rack->dgp_on;
2060 		log.u_bbr.bbr_state <<= 1;
2061 		log.u_bbr.bbr_state |= rack->rc_hybrid_mode;
2062 		log.u_bbr.bbr_state <<= 1;
2063 		log.u_bbr.bbr_state |= rack->use_fixed_rate;
2064 		log.u_bbr.flex8 = mod;
2065 		tcp_log_event(rack->rc_tp, NULL,
2066 		    &rack->rc_inp->inp_socket->so_rcv,
2067 		    &rack->rc_inp->inp_socket->so_snd,
2068 		    TCP_HYBRID_PACING_LOG, 0,
2069 		    0, &log, false, NULL, __func__, __LINE__, &tv);
2070 
2071 	}
2072 #endif
2073 }
2074 
2075 static inline uint64_t
2076 rack_compensate_for_linerate(struct tcp_rack *rack, uint64_t bw)
2077 {
2078 	uint64_t ret_bw, ether;
2079 	uint64_t u_segsiz;
2080 
2081 	ether = rack->rc_tp->t_maxseg + sizeof(struct tcphdr);
2082 	if (rack->r_is_v6){
2083 #ifdef INET6
2084 		ether += sizeof(struct ip6_hdr);
2085 #endif
2086 		ether += 14;	/* eheader size 6+6+2 */
2087 	} else {
2088 #ifdef INET
2089 		ether += sizeof(struct ip);
2090 #endif
2091 		ether += 14;	/* eheader size 6+6+2 */
2092 	}
2093 	u_segsiz = (uint64_t)min(ctf_fixed_maxseg(rack->rc_tp), rack->r_ctl.rc_pace_min_segs);
2094 	ret_bw = bw;
2095 	ret_bw *= ether;
2096 	ret_bw /= u_segsiz;
2097 	return (ret_bw);
2098 }
2099 
2100 static void
2101 rack_rate_cap_bw(struct tcp_rack *rack, uint64_t *bw, int *capped)
2102 {
2103 #ifdef TCP_REQUEST_TRK
2104 	struct timeval tv;
2105 	uint64_t timenow, timeleft, lenleft, lengone, calcbw;
2106 #endif
2107 
2108 	if (rack->r_ctl.bw_rate_cap == 0)
2109 		return;
2110 #ifdef TCP_REQUEST_TRK
2111 	if (rack->rc_catch_up && rack->rc_hybrid_mode &&
2112 	    (rack->r_ctl.rc_last_sft != NULL)) {
2113 		/*
2114 		 * We have a dynamic cap. The original target
2115 		 * is in bw_rate_cap, but we need to look at
2116 		 * how long it is until we hit the deadline.
2117 		 */
2118 		struct http_sendfile_track *ent;
2119 
2120 		ent = rack->r_ctl.rc_last_sft;
2121 		microuptime(&tv);
2122 		timenow = tcp_tv_to_lusectick(&tv);
2123 		if (timenow >= ent->deadline) {
2124 			/* No time left we do DGP only */
2125 			rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2126 					   0, 0, 0, HYBRID_LOG_OUTOFTIME, 0, ent);
2127 			rack->r_ctl.bw_rate_cap = 0;
2128 			return;
2129 		}
2130 		/* We have the time */
2131 		timeleft = rack->r_ctl.rc_last_sft->deadline - timenow;
2132 		if (timeleft < HPTS_MSEC_IN_SEC) {
2133 			/* If there is less than a ms left just use DGPs rate */
2134 			rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2135 					   0, timeleft, 0, HYBRID_LOG_OUTOFTIME, 0, ent);
2136 			rack->r_ctl.bw_rate_cap = 0;
2137 			return;
2138 		}
2139 		/*
2140 		 * Now lets find the amount of data left to send.
2141 		 *
2142 		 * Now ideally we want to use the end_seq to figure out how much more
2143 		 * but it might not be possible (only if we have the TRACK_FG_COMP on the entry..
2144 		 */
2145 		if (ent->flags & TCP_HTTP_TRACK_FLG_COMP) {
2146 			if (SEQ_GT(ent->end_seq, rack->rc_tp->snd_una))
2147 				lenleft = ent->end_seq - rack->rc_tp->snd_una;
2148 			else {
2149 				/* TSNH, we should catch it at the send */
2150 				rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2151 						   0, timeleft, 0, HYBRID_LOG_CAPERROR, 0, ent);
2152 				rack->r_ctl.bw_rate_cap = 0;
2153 				return;
2154 			}
2155 		} else {
2156 			/*
2157 			 * The hard way, figure out how much is gone and then
2158 			 * take that away from the total the client asked for
2159 			 * (thats off by tls overhead if this is tls).
2160 			 */
2161 			if (SEQ_GT(rack->rc_tp->snd_una, ent->start_seq))
2162 				lengone = rack->rc_tp->snd_una - ent->start_seq;
2163 			else
2164 				lengone = 0;
2165 			if (lengone < (ent->end - ent->start))
2166 				lenleft = (ent->end - ent->start) - lengone;
2167 			else {
2168 				/* TSNH, we should catch it at the send */
2169 				rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2170 						   0, timeleft, lengone, HYBRID_LOG_CAPERROR, 0, ent);
2171 				rack->r_ctl.bw_rate_cap = 0;
2172 				return;
2173 			}
2174 		}
2175 		if (lenleft == 0) {
2176 			/* We have it all sent */
2177 			rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2178 					   0, timeleft, lenleft, HYBRID_LOG_ALLSENT, 0, ent);
2179 			if (rack->r_ctl.bw_rate_cap)
2180 				goto normal_ratecap;
2181 			else
2182 				return;
2183 		}
2184 		calcbw = lenleft * HPTS_USEC_IN_SEC;
2185 		calcbw /= timeleft;
2186 		/* Now we must compensate for IP/TCP overhead */
2187 		calcbw = rack_compensate_for_linerate(rack, calcbw);
2188 		/* Update the bit rate cap */
2189 		rack->r_ctl.bw_rate_cap = calcbw;
2190 		if ((rack->r_ctl.rc_last_sft->hybrid_flags & TCP_HYBRID_PACING_S_MSS) &&
2191 		    (rack_hybrid_allow_set_maxseg == 1) &&
2192 		    ((rack->r_ctl.rc_last_sft->hybrid_flags & TCP_HYBRID_PACING_SETMSS) == 0)) {
2193 			/* Lets set in a smaller mss possibly here to match our rate-cap */
2194 			uint32_t orig_max;
2195 
2196 			orig_max = rack->r_ctl.rc_pace_max_segs;
2197 			rack->r_ctl.rc_last_sft->hybrid_flags |= TCP_HYBRID_PACING_SETMSS;
2198 			rack->r_ctl.rc_pace_max_segs = rack_get_pacing_len(rack, calcbw, ctf_fixed_maxseg(rack->rc_tp));
2199 			rack_log_type_pacing_sizes(rack->rc_tp, rack, rack->r_ctl.client_suggested_maxseg, orig_max, __LINE__, 5);
2200 		}
2201 		rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2202 				   calcbw, timeleft, lenleft, HYBRID_LOG_CAP_CALC, 0, ent);
2203 		if ((calcbw > 0) && (*bw > calcbw)) {
2204 			rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2205 					   *bw, ent->deadline, lenleft, HYBRID_LOG_RATE_CAP, 0, ent);
2206 			*capped = 1;
2207 			*bw = calcbw;
2208 		}
2209 		return;
2210 	}
2211 normal_ratecap:
2212 #endif
2213 	if ((rack->r_ctl.bw_rate_cap > 0) && (*bw > rack->r_ctl.bw_rate_cap)) {
2214 #ifdef TCP_REQUEST_TRK
2215 		if (rack->rc_hybrid_mode &&
2216 		    rack->rc_catch_up &&
2217 		    (rack->r_ctl.rc_last_sft->hybrid_flags & TCP_HYBRID_PACING_S_MSS) &&
2218 		    (rack_hybrid_allow_set_maxseg == 1) &&
2219 		    ((rack->r_ctl.rc_last_sft->hybrid_flags & TCP_HYBRID_PACING_SETMSS) == 0)) {
2220 			/* Lets set in a smaller mss possibly here to match our rate-cap */
2221 			uint32_t orig_max;
2222 
2223 			orig_max = rack->r_ctl.rc_pace_max_segs;
2224 			rack->r_ctl.rc_last_sft->hybrid_flags |= TCP_HYBRID_PACING_SETMSS;
2225 			rack->r_ctl.rc_pace_max_segs = rack_get_pacing_len(rack, rack->r_ctl.bw_rate_cap, ctf_fixed_maxseg(rack->rc_tp));
2226 			rack_log_type_pacing_sizes(rack->rc_tp, rack, rack->r_ctl.client_suggested_maxseg, orig_max, __LINE__, 5);
2227 		}
2228 #endif
2229 		*capped = 1;
2230 		*bw = rack->r_ctl.bw_rate_cap;
2231 		rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2232 				   *bw, 0, 0,
2233 				   HYBRID_LOG_RATE_CAP, 1, NULL);
2234 	}
2235 }
2236 
2237 static uint64_t
2238 rack_get_gp_est(struct tcp_rack *rack)
2239 {
2240 	uint64_t bw, lt_bw, ret_bw;
2241 
2242 	if (rack->rc_gp_filled == 0) {
2243 		/*
2244 		 * We have yet no b/w measurement,
2245 		 * if we have a user set initial bw
2246 		 * return it. If we don't have that and
2247 		 * we have an srtt, use the tcp IW (10) to
2248 		 * calculate a fictional b/w over the SRTT
2249 		 * which is more or less a guess. Note
2250 		 * we don't use our IW from rack on purpose
2251 		 * so if we have like IW=30, we are not
2252 		 * calculating a "huge" b/w.
2253 		 */
2254 		uint64_t srtt;
2255 
2256 		lt_bw = rack_get_lt_bw(rack);
2257 		if (lt_bw) {
2258 			/*
2259 			 * No goodput bw but a long-term b/w does exist
2260 			 * lets use that.
2261 			 */
2262 			ret_bw = lt_bw;
2263 			goto compensate;
2264 		}
2265 		if (rack->r_ctl.init_rate)
2266 			return (rack->r_ctl.init_rate);
2267 
2268 		/* Ok lets come up with the IW guess, if we have a srtt */
2269 		if (rack->rc_tp->t_srtt == 0) {
2270 			/*
2271 			 * Go with old pacing method
2272 			 * i.e. burst mitigation only.
2273 			 */
2274 			return (0);
2275 		}
2276 		/* Ok lets get the initial TCP win (not racks) */
2277 		bw = tcp_compute_initwnd(tcp_maxseg(rack->rc_tp));
2278 		srtt = (uint64_t)rack->rc_tp->t_srtt;
2279 		bw *= (uint64_t)USECS_IN_SECOND;
2280 		bw /= srtt;
2281 		ret_bw = bw;
2282 		goto compensate;
2283 
2284 	}
2285 	if (rack->r_ctl.num_measurements >= RACK_REQ_AVG) {
2286 		/* Averaging is done, we can return the value */
2287 		bw = rack->r_ctl.gp_bw;
2288 	} else {
2289 		/* Still doing initial average must calculate */
2290 		bw = rack->r_ctl.gp_bw / max(rack->r_ctl.num_measurements, 1);
2291 	}
2292 	lt_bw = rack_get_lt_bw(rack);
2293 	if (lt_bw == 0) {
2294 		/* If we don't have one then equate it to the gp_bw */
2295 		lt_bw = rack->r_ctl.gp_bw;
2296 	}
2297 	if ((rack->r_cwnd_was_clamped == 1) && (rack->r_clamped_gets_lower > 0)){
2298 		/*  if clamped take the lowest */
2299 		if (lt_bw < bw)
2300 			ret_bw = lt_bw;
2301 		else
2302 			ret_bw = bw;
2303 	} else {
2304 		/* If not set for clamped to get lowest, take the highest */
2305 		if (lt_bw > bw)
2306 			ret_bw = lt_bw;
2307 		else
2308 			ret_bw = bw;
2309 	}
2310 	/*
2311 	 * Now lets compensate based on the TCP/IP overhead. Our
2312 	 * Goodput estimate does not include this so we must pace out
2313 	 * a bit faster since our pacing calculations do. The pacing
2314 	 * calculations use the base ETHERNET_SEGMENT_SIZE and the segsiz
2315 	 * we are using to do this, so we do that here in the opposite
2316 	 * direction as well. This means that if we are tunneled and the
2317 	 * segsiz is say 1200 bytes we will get quite a boost, but its
2318 	 * compensated for in the pacing time the opposite way.
2319 	 */
2320 compensate:
2321 	ret_bw = rack_compensate_for_linerate(rack, ret_bw);
2322 	return(ret_bw);
2323 }
2324 
2325 
2326 static uint64_t
2327 rack_get_bw(struct tcp_rack *rack)
2328 {
2329 	uint64_t bw;
2330 
2331 	if (rack->use_fixed_rate) {
2332 		/* Return the fixed pacing rate */
2333 		return (rack_get_fixed_pacing_bw(rack));
2334 	}
2335 	bw = rack_get_gp_est(rack);
2336 	return (bw);
2337 }
2338 
2339 static uint16_t
2340 rack_get_output_gain(struct tcp_rack *rack, struct rack_sendmap *rsm)
2341 {
2342 	if (rack->use_fixed_rate) {
2343 		return (100);
2344 	} else if (rack->in_probe_rtt && (rsm == NULL))
2345 		return (rack->r_ctl.rack_per_of_gp_probertt);
2346 	else if ((IN_FASTRECOVERY(rack->rc_tp->t_flags) &&
2347 		  rack->r_ctl.rack_per_of_gp_rec)) {
2348 		if (rsm) {
2349 			/* a retransmission always use the recovery rate */
2350 			return (rack->r_ctl.rack_per_of_gp_rec);
2351 		} else if (rack->rack_rec_nonrxt_use_cr) {
2352 			/* Directed to use the configured rate */
2353 			goto configured_rate;
2354 		} else if (rack->rack_no_prr &&
2355 			   (rack->r_ctl.rack_per_of_gp_rec > 100)) {
2356 			/* No PRR, lets just use the b/w estimate only */
2357 			return (100);
2358 		} else {
2359 			/*
2360 			 * Here we may have a non-retransmit but we
2361 			 * have no overrides, so just use the recovery
2362 			 * rate (prr is in effect).
2363 			 */
2364 			return (rack->r_ctl.rack_per_of_gp_rec);
2365 		}
2366 	}
2367 configured_rate:
2368 	/* For the configured rate we look at our cwnd vs the ssthresh */
2369 	if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
2370 		return (rack->r_ctl.rack_per_of_gp_ss);
2371 	else
2372 		return (rack->r_ctl.rack_per_of_gp_ca);
2373 }
2374 
2375 static void
2376 rack_log_dsack_event(struct tcp_rack *rack, uint8_t mod, uint32_t flex4, uint32_t flex5, uint32_t flex6)
2377 {
2378 	/*
2379 	 * Types of logs (mod value)
2380 	 * 1 = dsack_persists reduced by 1 via T-O or fast recovery exit.
2381 	 * 2 = a dsack round begins, persist is reset to 16.
2382 	 * 3 = a dsack round ends
2383 	 * 4 = Dsack option increases rack rtt flex5 is the srtt input, flex6 is thresh
2384 	 * 5 = Socket option set changing the control flags rc_rack_tmr_std_based, rc_rack_use_dsack
2385 	 * 6 = Final rack rtt, flex4 is srtt and flex6 is final limited thresh.
2386 	 */
2387 	if (tcp_bblogging_on(rack->rc_tp)) {
2388 		union tcp_log_stackspecific log;
2389 		struct timeval tv;
2390 
2391 		memset(&log, 0, sizeof(log));
2392 		log.u_bbr.flex1 = rack->rc_rack_tmr_std_based;
2393 		log.u_bbr.flex1 <<= 1;
2394 		log.u_bbr.flex1 |= rack->rc_rack_use_dsack;
2395 		log.u_bbr.flex1 <<= 1;
2396 		log.u_bbr.flex1 |= rack->rc_dsack_round_seen;
2397 		log.u_bbr.flex2 = rack->r_ctl.dsack_round_end;
2398 		log.u_bbr.flex3 = rack->r_ctl.num_dsack;
2399 		log.u_bbr.flex4 = flex4;
2400 		log.u_bbr.flex5 = flex5;
2401 		log.u_bbr.flex6 = flex6;
2402 		log.u_bbr.flex7 = rack->r_ctl.dsack_persist;
2403 		log.u_bbr.flex8 = mod;
2404 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2405 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2406 		    &rack->rc_inp->inp_socket->so_rcv,
2407 		    &rack->rc_inp->inp_socket->so_snd,
2408 		    RACK_DSACK_HANDLING, 0,
2409 		    0, &log, false, &tv);
2410 	}
2411 }
2412 
2413 static void
2414 rack_log_hdwr_pacing(struct tcp_rack *rack,
2415 		     uint64_t rate, uint64_t hw_rate, int line,
2416 		     int error, uint16_t mod)
2417 {
2418 	if (tcp_bblogging_on(rack->rc_tp)) {
2419 		union tcp_log_stackspecific log;
2420 		struct timeval tv;
2421 		const struct ifnet *ifp;
2422 
2423 		memset(&log, 0, sizeof(log));
2424 		log.u_bbr.flex1 = ((hw_rate >> 32) & 0x00000000ffffffff);
2425 		log.u_bbr.flex2 = (hw_rate & 0x00000000ffffffff);
2426 		if (rack->r_ctl.crte) {
2427 			ifp = rack->r_ctl.crte->ptbl->rs_ifp;
2428 		} else if (rack->rc_inp->inp_route.ro_nh &&
2429 			   rack->rc_inp->inp_route.ro_nh->nh_ifp) {
2430 			ifp = rack->rc_inp->inp_route.ro_nh->nh_ifp;
2431 		} else
2432 			ifp = NULL;
2433 		if (ifp) {
2434 			log.u_bbr.flex3 = (((uint64_t)ifp  >> 32) & 0x00000000ffffffff);
2435 			log.u_bbr.flex4 = ((uint64_t)ifp & 0x00000000ffffffff);
2436 		}
2437 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2438 		log.u_bbr.bw_inuse = rate;
2439 		log.u_bbr.flex5 = line;
2440 		log.u_bbr.flex6 = error;
2441 		log.u_bbr.flex7 = mod;
2442 		log.u_bbr.applimited = rack->r_ctl.rc_pace_max_segs;
2443 		log.u_bbr.flex8 = rack->use_fixed_rate;
2444 		log.u_bbr.flex8 <<= 1;
2445 		log.u_bbr.flex8 |= rack->rack_hdrw_pacing;
2446 		log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
2447 		log.u_bbr.delRate = rack->r_ctl.crte_prev_rate;
2448 		if (rack->r_ctl.crte)
2449 			log.u_bbr.cur_del_rate = rack->r_ctl.crte->rate;
2450 		else
2451 			log.u_bbr.cur_del_rate = 0;
2452 		log.u_bbr.rttProp = rack->r_ctl.last_hw_bw_req;
2453 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2454 		    &rack->rc_inp->inp_socket->so_rcv,
2455 		    &rack->rc_inp->inp_socket->so_snd,
2456 		    BBR_LOG_HDWR_PACE, 0,
2457 		    0, &log, false, &tv);
2458 	}
2459 }
2460 
2461 static uint64_t
2462 rack_get_output_bw(struct tcp_rack *rack, uint64_t bw, struct rack_sendmap *rsm, int *capped)
2463 {
2464 	/*
2465 	 * We allow rack_per_of_gp_xx to dictate our bw rate we want.
2466 	 */
2467 	uint64_t bw_est, high_rate;
2468 	uint64_t gain;
2469 
2470 	if ((rack->r_pacing_discount == 0) ||
2471 	    (rack_full_buffer_discount == 0)) {
2472 		/*
2473 		 * No buffer level based discount from client buffer
2474 		 * level is enabled or the feature is disabled.
2475 		 */
2476 		gain = (uint64_t)rack_get_output_gain(rack, rsm);
2477 		bw_est = bw * gain;
2478 		bw_est /= (uint64_t)100;
2479 	} else {
2480 		/*
2481 		 * We have a discount in place apply it with
2482 		 * just a 100% gain (we get no boost if the buffer
2483 		 * is full).
2484 		 */
2485 		uint64_t discount;
2486 
2487 		discount = bw * (uint64_t)(rack_full_buffer_discount * rack->r_ctl.pacing_discount_amm);
2488 		discount /= 100;
2489 		/* What %% of the b/w do we discount */
2490 		bw_est = bw - discount;
2491 	}
2492 	/* Never fall below the minimum (def 64kbps) */
2493 	if (bw_est < RACK_MIN_BW)
2494 		bw_est = RACK_MIN_BW;
2495 	if (rack->r_rack_hw_rate_caps) {
2496 		/* Rate caps are in place */
2497 		if (rack->r_ctl.crte != NULL) {
2498 			/* We have a hdwr rate already */
2499 			high_rate = tcp_hw_highest_rate(rack->r_ctl.crte);
2500 			if (bw_est >= high_rate) {
2501 				/* We are capping bw at the highest rate table entry */
2502 				if (rack_hw_rate_cap_per &&
2503 				    (((high_rate * (100 + rack_hw_rate_cap_per)) / 100) < bw_est)) {
2504 					rack->r_rack_hw_rate_caps = 0;
2505 					goto done;
2506 				}
2507 				rack_log_hdwr_pacing(rack,
2508 						     bw_est, high_rate, __LINE__,
2509 						     0, 3);
2510 				bw_est = high_rate;
2511 				if (capped)
2512 					*capped = 1;
2513 			}
2514 		} else if ((rack->rack_hdrw_pacing == 0) &&
2515 			   (rack->rack_hdw_pace_ena) &&
2516 			   (rack->rack_attempt_hdwr_pace == 0) &&
2517 			   (rack->rc_inp->inp_route.ro_nh != NULL) &&
2518 			   (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
2519 			/*
2520 			 * Special case, we have not yet attempted hardware
2521 			 * pacing, and yet we may, when we do, find out if we are
2522 			 * above the highest rate. We need to know the maxbw for the interface
2523 			 * in question (if it supports ratelimiting). We get back
2524 			 * a 0, if the interface is not found in the RL lists.
2525 			 */
2526 			high_rate = tcp_hw_highest_rate_ifp(rack->rc_inp->inp_route.ro_nh->nh_ifp, rack->rc_inp);
2527 			if (high_rate) {
2528 				/* Yep, we have a rate is it above this rate? */
2529 				if (bw_est > high_rate) {
2530 					bw_est = high_rate;
2531 					if (capped)
2532 						*capped = 1;
2533 				}
2534 			}
2535 		}
2536 	}
2537 done:
2538 	return (bw_est);
2539 }
2540 
2541 static void
2542 rack_log_retran_reason(struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t tsused, uint32_t thresh, int mod)
2543 {
2544 	if (tcp_bblogging_on(rack->rc_tp)) {
2545 		union tcp_log_stackspecific log;
2546 		struct timeval tv;
2547 
2548 		if (rack->sack_attack_disable > 0)
2549 			goto log_anyway;
2550 		if ((mod != 1) && (rack_verbose_logging == 0))  {
2551 			/*
2552 			 * We get 3 values currently for mod
2553 			 * 1 - We are retransmitting and this tells the reason.
2554 			 * 2 - We are clearing a dup-ack count.
2555 			 * 3 - We are incrementing a dup-ack count.
2556 			 *
2557 			 * The clear/increment are only logged
2558 			 * if you have BBverbose on.
2559 			 */
2560 			return;
2561 		}
2562 log_anyway:
2563 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2564 		log.u_bbr.flex1 = tsused;
2565 		log.u_bbr.flex2 = thresh;
2566 		log.u_bbr.flex3 = rsm->r_flags;
2567 		log.u_bbr.flex4 = rsm->r_dupack;
2568 		log.u_bbr.flex5 = rsm->r_start;
2569 		log.u_bbr.flex6 = rsm->r_end;
2570 		log.u_bbr.flex8 = mod;
2571 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2572 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2573 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2574 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2575 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2576 		log.u_bbr.pacing_gain = rack->r_must_retran;
2577 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2578 		    &rack->rc_inp->inp_socket->so_rcv,
2579 		    &rack->rc_inp->inp_socket->so_snd,
2580 		    BBR_LOG_SETTINGS_CHG, 0,
2581 		    0, &log, false, &tv);
2582 	}
2583 }
2584 
2585 static void
2586 rack_log_to_start(struct tcp_rack *rack, uint32_t cts, uint32_t to, int32_t slot, uint8_t which)
2587 {
2588 	if (tcp_bblogging_on(rack->rc_tp)) {
2589 		union tcp_log_stackspecific log;
2590 		struct timeval tv;
2591 
2592 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2593 		log.u_bbr.flex1 = rack->rc_tp->t_srtt;
2594 		log.u_bbr.flex2 = to;
2595 		log.u_bbr.flex3 = rack->r_ctl.rc_hpts_flags;
2596 		log.u_bbr.flex4 = slot;
2597 		log.u_bbr.flex5 = rack->rc_inp->inp_hptsslot;
2598 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2599 		log.u_bbr.flex7 = rack->rc_in_persist;
2600 		log.u_bbr.flex8 = which;
2601 		if (rack->rack_no_prr)
2602 			log.u_bbr.pkts_out = 0;
2603 		else
2604 			log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
2605 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2606 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2607 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2608 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2609 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2610 		log.u_bbr.pacing_gain = rack->r_must_retran;
2611 		log.u_bbr.cwnd_gain = rack->rack_deferred_inited;
2612 		log.u_bbr.pkt_epoch = rack->rc_has_collapsed;
2613 		log.u_bbr.lt_epoch = rack->rc_tp->t_rxtshift;
2614 		log.u_bbr.lost = rack_rto_min;
2615 		log.u_bbr.epoch = rack->r_ctl.roundends;
2616 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2617 		    &rack->rc_inp->inp_socket->so_rcv,
2618 		    &rack->rc_inp->inp_socket->so_snd,
2619 		    BBR_LOG_TIMERSTAR, 0,
2620 		    0, &log, false, &tv);
2621 	}
2622 }
2623 
2624 static void
2625 rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm)
2626 {
2627 	if (tcp_bblogging_on(rack->rc_tp)) {
2628 		union tcp_log_stackspecific log;
2629 		struct timeval tv;
2630 
2631 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2632 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2633 		log.u_bbr.flex8 = to_num;
2634 		log.u_bbr.flex1 = rack->r_ctl.rc_rack_min_rtt;
2635 		log.u_bbr.flex2 = rack->rc_rack_rtt;
2636 		if (rsm == NULL)
2637 			log.u_bbr.flex3 = 0;
2638 		else
2639 			log.u_bbr.flex3 = rsm->r_end - rsm->r_start;
2640 		if (rack->rack_no_prr)
2641 			log.u_bbr.flex5 = 0;
2642 		else
2643 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2644 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2645 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2646 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2647 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2648 		log.u_bbr.pacing_gain = rack->r_must_retran;
2649 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2650 		    &rack->rc_inp->inp_socket->so_rcv,
2651 		    &rack->rc_inp->inp_socket->so_snd,
2652 		    BBR_LOG_RTO, 0,
2653 		    0, &log, false, &tv);
2654 	}
2655 }
2656 
2657 static void
2658 rack_log_map_chg(struct tcpcb *tp, struct tcp_rack *rack,
2659 		 struct rack_sendmap *prev,
2660 		 struct rack_sendmap *rsm,
2661 		 struct rack_sendmap *next,
2662 		 int flag, uint32_t th_ack, int line)
2663 {
2664 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
2665 		union tcp_log_stackspecific log;
2666 		struct timeval tv;
2667 
2668 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2669 		log.u_bbr.flex8 = flag;
2670 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2671 		log.u_bbr.cur_del_rate = (uint64_t)prev;
2672 		log.u_bbr.delRate = (uint64_t)rsm;
2673 		log.u_bbr.rttProp = (uint64_t)next;
2674 		log.u_bbr.flex7 = 0;
2675 		if (prev) {
2676 			log.u_bbr.flex1 = prev->r_start;
2677 			log.u_bbr.flex2 = prev->r_end;
2678 			log.u_bbr.flex7 |= 0x4;
2679 		}
2680 		if (rsm) {
2681 			log.u_bbr.flex3 = rsm->r_start;
2682 			log.u_bbr.flex4 = rsm->r_end;
2683 			log.u_bbr.flex7 |= 0x2;
2684 		}
2685 		if (next) {
2686 			log.u_bbr.flex5 = next->r_start;
2687 			log.u_bbr.flex6 = next->r_end;
2688 			log.u_bbr.flex7 |= 0x1;
2689 		}
2690 		log.u_bbr.applimited = line;
2691 		log.u_bbr.pkts_out = th_ack;
2692 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2693 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2694 		if (rack->rack_no_prr)
2695 			log.u_bbr.lost = 0;
2696 		else
2697 			log.u_bbr.lost = rack->r_ctl.rc_prr_sndcnt;
2698 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2699 		    &rack->rc_inp->inp_socket->so_rcv,
2700 		    &rack->rc_inp->inp_socket->so_snd,
2701 		    TCP_LOG_MAPCHG, 0,
2702 		    0, &log, false, &tv);
2703 	}
2704 }
2705 
2706 static void
2707 rack_log_rtt_upd(struct tcpcb *tp, struct tcp_rack *rack, uint32_t t, uint32_t len,
2708 		 struct rack_sendmap *rsm, int conf)
2709 {
2710 	if (tcp_bblogging_on(tp)) {
2711 		union tcp_log_stackspecific log;
2712 		struct timeval tv;
2713 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2714 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2715 		log.u_bbr.flex1 = t;
2716 		log.u_bbr.flex2 = len;
2717 		log.u_bbr.flex3 = rack->r_ctl.rc_rack_min_rtt;
2718 		log.u_bbr.flex4 = rack->r_ctl.rack_rs.rs_rtt_lowest;
2719 		log.u_bbr.flex5 = rack->r_ctl.rack_rs.rs_rtt_highest;
2720 		log.u_bbr.flex6 = rack->r_ctl.rack_rs.rs_us_rtrcnt;
2721 		log.u_bbr.flex7 = conf;
2722 		log.u_bbr.rttProp = (uint64_t)rack->r_ctl.rack_rs.rs_rtt_tot;
2723 		log.u_bbr.flex8 = rack->r_ctl.rc_rate_sample_method;
2724 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2725 		log.u_bbr.delivered = rack->r_ctl.rack_rs.rs_us_rtrcnt;
2726 		log.u_bbr.pkts_out = rack->r_ctl.rack_rs.rs_flags;
2727 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2728 		if (rsm) {
2729 			log.u_bbr.pkt_epoch = rsm->r_start;
2730 			log.u_bbr.lost = rsm->r_end;
2731 			log.u_bbr.cwnd_gain = rsm->r_rtr_cnt;
2732 			/* We loose any upper of the 24 bits */
2733 			log.u_bbr.pacing_gain = (uint16_t)rsm->r_flags;
2734 		} else {
2735 			/* Its a SYN */
2736 			log.u_bbr.pkt_epoch = rack->rc_tp->iss;
2737 			log.u_bbr.lost = 0;
2738 			log.u_bbr.cwnd_gain = 0;
2739 			log.u_bbr.pacing_gain = 0;
2740 		}
2741 		/* Write out general bits of interest rrs here */
2742 		log.u_bbr.use_lt_bw = rack->rc_highly_buffered;
2743 		log.u_bbr.use_lt_bw <<= 1;
2744 		log.u_bbr.use_lt_bw |= rack->forced_ack;
2745 		log.u_bbr.use_lt_bw <<= 1;
2746 		log.u_bbr.use_lt_bw |= rack->rc_gp_dyn_mul;
2747 		log.u_bbr.use_lt_bw <<= 1;
2748 		log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
2749 		log.u_bbr.use_lt_bw <<= 1;
2750 		log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
2751 		log.u_bbr.use_lt_bw <<= 1;
2752 		log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
2753 		log.u_bbr.use_lt_bw <<= 1;
2754 		log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
2755 		log.u_bbr.use_lt_bw <<= 1;
2756 		log.u_bbr.use_lt_bw |= rack->rc_dragged_bottom;
2757 		log.u_bbr.applimited = rack->r_ctl.rc_target_probertt_flight;
2758 		log.u_bbr.epoch = rack->r_ctl.rc_time_probertt_starts;
2759 		log.u_bbr.lt_epoch = rack->r_ctl.rc_time_probertt_entered;
2760 		log.u_bbr.cur_del_rate = rack->r_ctl.rc_lower_rtt_us_cts;
2761 		log.u_bbr.delRate = rack->r_ctl.rc_gp_srtt;
2762 		log.u_bbr.bw_inuse = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
2763 		log.u_bbr.bw_inuse <<= 32;
2764 		if (rsm)
2765 			log.u_bbr.bw_inuse |= ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]);
2766 		TCP_LOG_EVENTP(tp, NULL,
2767 		    &rack->rc_inp->inp_socket->so_rcv,
2768 		    &rack->rc_inp->inp_socket->so_snd,
2769 		    BBR_LOG_BBRRTT, 0,
2770 		    0, &log, false, &tv);
2771 
2772 
2773 	}
2774 }
2775 
2776 static void
2777 rack_log_rtt_sample(struct tcp_rack *rack, uint32_t rtt)
2778 {
2779 	/*
2780 	 * Log the rtt sample we are
2781 	 * applying to the srtt algorithm in
2782 	 * useconds.
2783 	 */
2784 	if (tcp_bblogging_on(rack->rc_tp)) {
2785 		union tcp_log_stackspecific log;
2786 		struct timeval tv;
2787 
2788 		/* Convert our ms to a microsecond */
2789 		memset(&log, 0, sizeof(log));
2790 		log.u_bbr.flex1 = rtt;
2791 		log.u_bbr.flex2 = rack->r_ctl.ack_count;
2792 		log.u_bbr.flex3 = rack->r_ctl.sack_count;
2793 		log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move;
2794 		log.u_bbr.flex5 = rack->r_ctl.sack_moved_extra;
2795 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2796 		log.u_bbr.flex7 = 1;
2797 		log.u_bbr.flex8 = rack->sack_attack_disable;
2798 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2799 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2800 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2801 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2802 		log.u_bbr.pacing_gain = rack->r_must_retran;
2803 		/*
2804 		 * We capture in delRate the upper 32 bits as
2805 		 * the confidence level we had declared, and the
2806 		 * lower 32 bits as the actual RTT using the arrival
2807 		 * timestamp.
2808 		 */
2809 		log.u_bbr.delRate = rack->r_ctl.rack_rs.confidence;
2810 		log.u_bbr.delRate <<= 32;
2811 		log.u_bbr.delRate |= rack->r_ctl.rack_rs.rs_us_rtt;
2812 		/* Lets capture all the things that make up t_rtxcur */
2813 		log.u_bbr.applimited = rack_rto_min;
2814 		log.u_bbr.epoch = rack_rto_max;
2815 		log.u_bbr.lt_epoch = rack->r_ctl.timer_slop;
2816 		log.u_bbr.lost = rack_rto_min;
2817 		log.u_bbr.pkt_epoch = TICKS_2_USEC(tcp_rexmit_slop);
2818 		log.u_bbr.rttProp = RACK_REXMTVAL(rack->rc_tp);
2819 		log.u_bbr.bw_inuse = rack->r_ctl.act_rcv_time.tv_sec;
2820 		log.u_bbr.bw_inuse *= HPTS_USEC_IN_SEC;
2821 		log.u_bbr.bw_inuse += rack->r_ctl.act_rcv_time.tv_usec;
2822 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2823 		    &rack->rc_inp->inp_socket->so_rcv,
2824 		    &rack->rc_inp->inp_socket->so_snd,
2825 		    TCP_LOG_RTT, 0,
2826 		    0, &log, false, &tv);
2827 	}
2828 }
2829 
2830 static void
2831 rack_log_rtt_sample_calc(struct tcp_rack *rack, uint32_t rtt, uint32_t send_time, uint32_t ack_time, int where)
2832 {
2833 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
2834 		union tcp_log_stackspecific log;
2835 		struct timeval tv;
2836 
2837 		/* Convert our ms to a microsecond */
2838 		memset(&log, 0, sizeof(log));
2839 		log.u_bbr.flex1 = rtt;
2840 		log.u_bbr.flex2 = send_time;
2841 		log.u_bbr.flex3 = ack_time;
2842 		log.u_bbr.flex4 = where;
2843 		log.u_bbr.flex7 = 2;
2844 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2845 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2846 		    &rack->rc_inp->inp_socket->so_rcv,
2847 		    &rack->rc_inp->inp_socket->so_snd,
2848 		    TCP_LOG_RTT, 0,
2849 		    0, &log, false, &tv);
2850 	}
2851 }
2852 
2853 
2854 static void
2855 rack_log_rtt_sendmap(struct tcp_rack *rack, uint32_t idx, uint64_t tsv, uint32_t tsecho)
2856 {
2857 	if (tcp_bblogging_on(rack->rc_tp)) {
2858 		union tcp_log_stackspecific log;
2859 		struct timeval tv;
2860 
2861 		/* Convert our ms to a microsecond */
2862 		memset(&log, 0, sizeof(log));
2863 		log.u_bbr.flex1 = idx;
2864 		log.u_bbr.flex2 = rack_ts_to_msec(tsv);
2865 		log.u_bbr.flex3 = tsecho;
2866 		log.u_bbr.flex7 = 3;
2867 		log.u_bbr.rttProp = tsv;
2868 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2869 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2870 		    &rack->rc_inp->inp_socket->so_rcv,
2871 		    &rack->rc_inp->inp_socket->so_snd,
2872 		    TCP_LOG_RTT, 0,
2873 		    0, &log, false, &tv);
2874 	}
2875 }
2876 
2877 
2878 static inline void
2879 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick,  int event, int line)
2880 {
2881 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
2882 		union tcp_log_stackspecific log;
2883 		struct timeval tv;
2884 
2885 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2886 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2887 		log.u_bbr.flex1 = line;
2888 		log.u_bbr.flex2 = tick;
2889 		log.u_bbr.flex3 = tp->t_maxunacktime;
2890 		log.u_bbr.flex4 = tp->t_acktime;
2891 		log.u_bbr.flex8 = event;
2892 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2893 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2894 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2895 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2896 		log.u_bbr.pacing_gain = rack->r_must_retran;
2897 		TCP_LOG_EVENTP(tp, NULL,
2898 		    &rack->rc_inp->inp_socket->so_rcv,
2899 		    &rack->rc_inp->inp_socket->so_snd,
2900 		    BBR_LOG_PROGRESS, 0,
2901 		    0, &log, false, &tv);
2902 	}
2903 }
2904 
2905 static void
2906 rack_log_type_bbrsnd(struct tcp_rack *rack, uint32_t len, uint32_t slot, uint32_t cts, struct timeval *tv, int line)
2907 {
2908 	if (tcp_bblogging_on(rack->rc_tp)) {
2909 		union tcp_log_stackspecific log;
2910 
2911 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2912 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2913 		log.u_bbr.flex1 = slot;
2914 		if (rack->rack_no_prr)
2915 			log.u_bbr.flex2 = 0;
2916 		else
2917 			log.u_bbr.flex2 = rack->r_ctl.rc_prr_sndcnt;
2918 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
2919 		log.u_bbr.flex5 = rack->r_ctl.ack_during_sd;
2920 		log.u_bbr.flex6 = line;
2921 		log.u_bbr.flex7 = (0x0000ffff & rack->r_ctl.rc_hpts_flags);
2922 		log.u_bbr.flex8 = rack->rc_in_persist;
2923 		log.u_bbr.timeStamp = cts;
2924 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2925 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2926 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2927 		log.u_bbr.pacing_gain = rack->r_must_retran;
2928 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2929 		    &rack->rc_inp->inp_socket->so_rcv,
2930 		    &rack->rc_inp->inp_socket->so_snd,
2931 		    BBR_LOG_BBRSND, 0,
2932 		    0, &log, false, tv);
2933 	}
2934 }
2935 
2936 static void
2937 rack_log_doseg_done(struct tcp_rack *rack, uint32_t cts, int32_t nxt_pkt, int32_t did_out, int way_out, int nsegs)
2938 {
2939 	if (tcp_bblogging_on(rack->rc_tp)) {
2940 		union tcp_log_stackspecific log;
2941 		struct timeval tv;
2942 
2943 		memset(&log, 0, sizeof(log));
2944 		log.u_bbr.flex1 = did_out;
2945 		log.u_bbr.flex2 = nxt_pkt;
2946 		log.u_bbr.flex3 = way_out;
2947 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
2948 		if (rack->rack_no_prr)
2949 			log.u_bbr.flex5 = 0;
2950 		else
2951 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2952 		log.u_bbr.flex6 = nsegs;
2953 		log.u_bbr.applimited = rack->r_ctl.rc_pace_min_segs;
2954 		log.u_bbr.flex7 = rack->rc_ack_can_sendout_data;	/* Do we have ack-can-send set */
2955 		log.u_bbr.flex7 <<= 1;
2956 		log.u_bbr.flex7 |= rack->r_fast_output;	/* is fast output primed */
2957 		log.u_bbr.flex7 <<= 1;
2958 		log.u_bbr.flex7 |= rack->r_wanted_output;	/* Do we want output */
2959 		log.u_bbr.flex8 = rack->rc_in_persist;
2960 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2961 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2962 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2963 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
2964 		log.u_bbr.use_lt_bw <<= 1;
2965 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
2966 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2967 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2968 		log.u_bbr.pacing_gain = rack->r_must_retran;
2969 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2970 		    &rack->rc_inp->inp_socket->so_rcv,
2971 		    &rack->rc_inp->inp_socket->so_snd,
2972 		    BBR_LOG_DOSEG_DONE, 0,
2973 		    0, &log, false, &tv);
2974 	}
2975 }
2976 
2977 static void
2978 rack_log_type_pacing_sizes(struct tcpcb *tp, struct tcp_rack *rack, uint32_t arg1, uint32_t arg2, uint32_t arg3, uint8_t frm)
2979 {
2980 	if (tcp_bblogging_on(rack->rc_tp)) {
2981 		union tcp_log_stackspecific log;
2982 		struct timeval tv;
2983 
2984 		memset(&log, 0, sizeof(log));
2985 		log.u_bbr.flex1 = rack->r_ctl.rc_pace_min_segs;
2986 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
2987 		log.u_bbr.flex4 = arg1;
2988 		log.u_bbr.flex5 = arg2;
2989 		log.u_bbr.flex7 = rack->r_ctl.rc_user_set_min_segs;
2990 		log.u_bbr.flex6 = arg3;
2991 		log.u_bbr.flex8 = frm;
2992 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2993 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2994 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2995 		log.u_bbr.applimited = rack->r_ctl.rc_sacked;
2996 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2997 		log.u_bbr.pacing_gain = rack->r_must_retran;
2998 		TCP_LOG_EVENTP(tp, NULL, &tptosocket(tp)->so_rcv,
2999 		    &tptosocket(tp)->so_snd,
3000 		    TCP_HDWR_PACE_SIZE, 0, 0, &log, false, &tv);
3001 	}
3002 }
3003 
3004 static void
3005 rack_log_type_just_return(struct tcp_rack *rack, uint32_t cts, uint32_t tlen, uint32_t slot,
3006 			  uint8_t hpts_calling, int reason, uint32_t cwnd_to_use)
3007 {
3008 	if (tcp_bblogging_on(rack->rc_tp)) {
3009 		union tcp_log_stackspecific log;
3010 		struct timeval tv;
3011 
3012 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3013 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
3014 		log.u_bbr.flex1 = slot;
3015 		log.u_bbr.flex2 = rack->r_ctl.rc_hpts_flags;
3016 		log.u_bbr.flex4 = reason;
3017 		if (rack->rack_no_prr)
3018 			log.u_bbr.flex5 = 0;
3019 		else
3020 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
3021 		log.u_bbr.flex7 = hpts_calling;
3022 		log.u_bbr.flex8 = rack->rc_in_persist;
3023 		log.u_bbr.lt_epoch = cwnd_to_use;
3024 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3025 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3026 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
3027 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
3028 		log.u_bbr.pacing_gain = rack->r_must_retran;
3029 		log.u_bbr.cwnd_gain = rack->rc_has_collapsed;
3030 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3031 		    &rack->rc_inp->inp_socket->so_rcv,
3032 		    &rack->rc_inp->inp_socket->so_snd,
3033 		    BBR_LOG_JUSTRET, 0,
3034 		    tlen, &log, false, &tv);
3035 	}
3036 }
3037 
3038 static void
3039 rack_log_to_cancel(struct tcp_rack *rack, int32_t hpts_removed, int line, uint32_t us_cts,
3040 		   struct timeval *tv, uint32_t flags_on_entry)
3041 {
3042 	if (tcp_bblogging_on(rack->rc_tp)) {
3043 		union tcp_log_stackspecific log;
3044 
3045 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3046 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
3047 		log.u_bbr.flex1 = line;
3048 		log.u_bbr.flex2 = rack->r_ctl.rc_last_output_to;
3049 		log.u_bbr.flex3 = flags_on_entry;
3050 		log.u_bbr.flex4 = us_cts;
3051 		if (rack->rack_no_prr)
3052 			log.u_bbr.flex5 = 0;
3053 		else
3054 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
3055 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
3056 		log.u_bbr.flex7 = hpts_removed;
3057 		log.u_bbr.flex8 = 1;
3058 		log.u_bbr.applimited = rack->r_ctl.rc_hpts_flags;
3059 		log.u_bbr.timeStamp = us_cts;
3060 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3061 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
3062 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
3063 		log.u_bbr.pacing_gain = rack->r_must_retran;
3064 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3065 		    &rack->rc_inp->inp_socket->so_rcv,
3066 		    &rack->rc_inp->inp_socket->so_snd,
3067 		    BBR_LOG_TIMERCANC, 0,
3068 		    0, &log, false, tv);
3069 	}
3070 }
3071 
3072 static void
3073 rack_log_alt_to_to_cancel(struct tcp_rack *rack,
3074 			  uint32_t flex1, uint32_t flex2,
3075 			  uint32_t flex3, uint32_t flex4,
3076 			  uint32_t flex5, uint32_t flex6,
3077 			  uint16_t flex7, uint8_t mod)
3078 {
3079 	if (tcp_bblogging_on(rack->rc_tp)) {
3080 		union tcp_log_stackspecific log;
3081 		struct timeval tv;
3082 
3083 		if (mod == 1) {
3084 			/* No you can't use 1, its for the real to cancel */
3085 			return;
3086 		}
3087 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3088 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3089 		log.u_bbr.flex1 = flex1;
3090 		log.u_bbr.flex2 = flex2;
3091 		log.u_bbr.flex3 = flex3;
3092 		log.u_bbr.flex4 = flex4;
3093 		log.u_bbr.flex5 = flex5;
3094 		log.u_bbr.flex6 = flex6;
3095 		log.u_bbr.flex7 = flex7;
3096 		log.u_bbr.flex8 = mod;
3097 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3098 		    &rack->rc_inp->inp_socket->so_rcv,
3099 		    &rack->rc_inp->inp_socket->so_snd,
3100 		    BBR_LOG_TIMERCANC, 0,
3101 		    0, &log, false, &tv);
3102 	}
3103 }
3104 
3105 static void
3106 rack_log_to_processing(struct tcp_rack *rack, uint32_t cts, int32_t ret, int32_t timers)
3107 {
3108 	if (tcp_bblogging_on(rack->rc_tp)) {
3109 		union tcp_log_stackspecific log;
3110 		struct timeval tv;
3111 
3112 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3113 		log.u_bbr.flex1 = timers;
3114 		log.u_bbr.flex2 = ret;
3115 		log.u_bbr.flex3 = rack->r_ctl.rc_timer_exp;
3116 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
3117 		log.u_bbr.flex5 = cts;
3118 		if (rack->rack_no_prr)
3119 			log.u_bbr.flex6 = 0;
3120 		else
3121 			log.u_bbr.flex6 = rack->r_ctl.rc_prr_sndcnt;
3122 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
3123 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
3124 		log.u_bbr.pacing_gain = rack->r_must_retran;
3125 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3126 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3127 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3128 		    &rack->rc_inp->inp_socket->so_rcv,
3129 		    &rack->rc_inp->inp_socket->so_snd,
3130 		    BBR_LOG_TO_PROCESS, 0,
3131 		    0, &log, false, &tv);
3132 	}
3133 }
3134 
3135 static void
3136 rack_log_to_prr(struct tcp_rack *rack, int frm, int orig_cwnd, int line)
3137 {
3138 	if (tcp_bblogging_on(rack->rc_tp)) {
3139 		union tcp_log_stackspecific log;
3140 		struct timeval tv;
3141 
3142 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3143 		log.u_bbr.flex1 = rack->r_ctl.rc_prr_out;
3144 		log.u_bbr.flex2 = rack->r_ctl.rc_prr_recovery_fs;
3145 		if (rack->rack_no_prr)
3146 			log.u_bbr.flex3 = 0;
3147 		else
3148 			log.u_bbr.flex3 = rack->r_ctl.rc_prr_sndcnt;
3149 		log.u_bbr.flex4 = rack->r_ctl.rc_prr_delivered;
3150 		log.u_bbr.flex5 = rack->r_ctl.rc_sacked;
3151 		log.u_bbr.flex6 = rack->r_ctl.rc_holes_rxt;
3152 		log.u_bbr.flex7 = line;
3153 		log.u_bbr.flex8 = frm;
3154 		log.u_bbr.pkts_out = orig_cwnd;
3155 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3156 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3157 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
3158 		log.u_bbr.use_lt_bw <<= 1;
3159 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
3160 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3161 		    &rack->rc_inp->inp_socket->so_rcv,
3162 		    &rack->rc_inp->inp_socket->so_snd,
3163 		    BBR_LOG_BBRUPD, 0,
3164 		    0, &log, false, &tv);
3165 	}
3166 }
3167 
3168 #ifdef TCP_SAD_DETECTION
3169 static void
3170 rack_log_sad(struct tcp_rack *rack, int event)
3171 {
3172 	if (tcp_bblogging_on(rack->rc_tp)) {
3173 		union tcp_log_stackspecific log;
3174 		struct timeval tv;
3175 
3176 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3177 		log.u_bbr.flex1 = rack->r_ctl.sack_count;
3178 		log.u_bbr.flex2 = rack->r_ctl.ack_count;
3179 		log.u_bbr.flex3 = rack->r_ctl.sack_moved_extra;
3180 		log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move;
3181 		log.u_bbr.flex5 = rack->r_ctl.rc_num_maps_alloced;
3182 		log.u_bbr.flex6 = tcp_sack_to_ack_thresh;
3183 		log.u_bbr.pkts_out = tcp_sack_to_move_thresh;
3184 		log.u_bbr.lt_epoch = (tcp_force_detection << 8);
3185 		log.u_bbr.lt_epoch |= rack->do_detection;
3186 		log.u_bbr.applimited = tcp_map_minimum;
3187 		log.u_bbr.flex7 = rack->sack_attack_disable;
3188 		log.u_bbr.flex8 = event;
3189 		log.u_bbr.bbr_state = rack->rc_suspicious;
3190 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3191 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3192 		log.u_bbr.delivered = tcp_sad_decay_val;
3193 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3194 		    &rack->rc_inp->inp_socket->so_rcv,
3195 		    &rack->rc_inp->inp_socket->so_snd,
3196 		    TCP_SAD_DETECT, 0,
3197 		    0, &log, false, &tv);
3198 	}
3199 }
3200 #endif
3201 
3202 static void
3203 rack_counter_destroy(void)
3204 {
3205 	counter_u64_free(rack_total_bytes);
3206 	counter_u64_free(rack_fto_send);
3207 	counter_u64_free(rack_fto_rsm_send);
3208 	counter_u64_free(rack_nfto_resend);
3209 	counter_u64_free(rack_hw_pace_init_fail);
3210 	counter_u64_free(rack_hw_pace_lost);
3211 	counter_u64_free(rack_non_fto_send);
3212 	counter_u64_free(rack_extended_rfo);
3213 	counter_u64_free(rack_ack_total);
3214 	counter_u64_free(rack_express_sack);
3215 	counter_u64_free(rack_sack_total);
3216 	counter_u64_free(rack_move_none);
3217 	counter_u64_free(rack_move_some);
3218 	counter_u64_free(rack_sack_attacks_detected);
3219 	counter_u64_free(rack_sack_attacks_reversed);
3220 	counter_u64_free(rack_sack_attacks_suspect);
3221 	counter_u64_free(rack_sack_used_next_merge);
3222 	counter_u64_free(rack_sack_used_prev_merge);
3223 	counter_u64_free(rack_tlp_tot);
3224 	counter_u64_free(rack_tlp_newdata);
3225 	counter_u64_free(rack_tlp_retran);
3226 	counter_u64_free(rack_tlp_retran_bytes);
3227 	counter_u64_free(rack_to_tot);
3228 	counter_u64_free(rack_saw_enobuf);
3229 	counter_u64_free(rack_saw_enobuf_hw);
3230 	counter_u64_free(rack_saw_enetunreach);
3231 	counter_u64_free(rack_hot_alloc);
3232 	counter_u64_free(rack_to_alloc);
3233 	counter_u64_free(rack_to_alloc_hard);
3234 	counter_u64_free(rack_to_alloc_emerg);
3235 	counter_u64_free(rack_to_alloc_limited);
3236 	counter_u64_free(rack_alloc_limited_conns);
3237 	counter_u64_free(rack_split_limited);
3238 	counter_u64_free(rack_multi_single_eq);
3239 	counter_u64_free(rack_rxt_clamps_cwnd);
3240 	counter_u64_free(rack_rxt_clamps_cwnd_uniq);
3241 	counter_u64_free(rack_proc_non_comp_ack);
3242 	counter_u64_free(rack_sack_proc_all);
3243 	counter_u64_free(rack_sack_proc_restart);
3244 	counter_u64_free(rack_sack_proc_short);
3245 	counter_u64_free(rack_sack_skipped_acked);
3246 	counter_u64_free(rack_sack_splits);
3247 	counter_u64_free(rack_input_idle_reduces);
3248 	counter_u64_free(rack_collapsed_win);
3249 	counter_u64_free(rack_collapsed_win_rxt);
3250 	counter_u64_free(rack_collapsed_win_rxt_bytes);
3251 	counter_u64_free(rack_collapsed_win_seen);
3252 	counter_u64_free(rack_try_scwnd);
3253 	counter_u64_free(rack_persists_sends);
3254 	counter_u64_free(rack_persists_acks);
3255 	counter_u64_free(rack_persists_loss);
3256 	counter_u64_free(rack_persists_lost_ends);
3257 #ifdef INVARIANTS
3258 	counter_u64_free(rack_adjust_map_bw);
3259 #endif
3260 	COUNTER_ARRAY_FREE(rack_out_size, TCP_MSS_ACCT_SIZE);
3261 	COUNTER_ARRAY_FREE(rack_opts_arry, RACK_OPTS_SIZE);
3262 }
3263 
3264 static struct rack_sendmap *
3265 rack_alloc(struct tcp_rack *rack)
3266 {
3267 	struct rack_sendmap *rsm;
3268 
3269 	/*
3270 	 * First get the top of the list it in
3271 	 * theory is the "hottest" rsm we have,
3272 	 * possibly just freed by ack processing.
3273 	 */
3274 	if (rack->rc_free_cnt > rack_free_cache) {
3275 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
3276 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
3277 		counter_u64_add(rack_hot_alloc, 1);
3278 		rack->rc_free_cnt--;
3279 		return (rsm);
3280 	}
3281 	/*
3282 	 * Once we get under our free cache we probably
3283 	 * no longer have a "hot" one available. Lets
3284 	 * get one from UMA.
3285 	 */
3286 	rsm = uma_zalloc(rack_zone, M_NOWAIT);
3287 	if (rsm) {
3288 		rack->r_ctl.rc_num_maps_alloced++;
3289 		counter_u64_add(rack_to_alloc, 1);
3290 		return (rsm);
3291 	}
3292 	/*
3293 	 * Dig in to our aux rsm's (the last two) since
3294 	 * UMA failed to get us one.
3295 	 */
3296 	if (rack->rc_free_cnt) {
3297 		counter_u64_add(rack_to_alloc_emerg, 1);
3298 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
3299 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
3300 		rack->rc_free_cnt--;
3301 		return (rsm);
3302 	}
3303 	return (NULL);
3304 }
3305 
3306 static struct rack_sendmap *
3307 rack_alloc_full_limit(struct tcp_rack *rack)
3308 {
3309 	if ((V_tcp_map_entries_limit > 0) &&
3310 	    (rack->do_detection == 0) &&
3311 	    (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
3312 		counter_u64_add(rack_to_alloc_limited, 1);
3313 		if (!rack->alloc_limit_reported) {
3314 			rack->alloc_limit_reported = 1;
3315 			counter_u64_add(rack_alloc_limited_conns, 1);
3316 		}
3317 		return (NULL);
3318 	}
3319 	return (rack_alloc(rack));
3320 }
3321 
3322 /* wrapper to allocate a sendmap entry, subject to a specific limit */
3323 static struct rack_sendmap *
3324 rack_alloc_limit(struct tcp_rack *rack, uint8_t limit_type)
3325 {
3326 	struct rack_sendmap *rsm;
3327 
3328 	if (limit_type) {
3329 		/* currently there is only one limit type */
3330 		if (rack->r_ctl.rc_split_limit > 0 &&
3331 		    (rack->do_detection == 0) &&
3332 		    rack->r_ctl.rc_num_split_allocs >= rack->r_ctl.rc_split_limit) {
3333 			counter_u64_add(rack_split_limited, 1);
3334 			if (!rack->alloc_limit_reported) {
3335 				rack->alloc_limit_reported = 1;
3336 				counter_u64_add(rack_alloc_limited_conns, 1);
3337 			}
3338 			return (NULL);
3339 #ifdef TCP_SAD_DETECTION
3340 		} else if ((tcp_sad_limit != 0) &&
3341 			   (rack->do_detection == 1) &&
3342 			   (rack->r_ctl.rc_num_split_allocs >= tcp_sad_limit)) {
3343 			counter_u64_add(rack_split_limited, 1);
3344 			if (!rack->alloc_limit_reported) {
3345 				rack->alloc_limit_reported = 1;
3346 				counter_u64_add(rack_alloc_limited_conns, 1);
3347 			}
3348 			return (NULL);
3349 #endif
3350 		}
3351 	}
3352 
3353 	/* allocate and mark in the limit type, if set */
3354 	rsm = rack_alloc(rack);
3355 	if (rsm != NULL && limit_type) {
3356 		rsm->r_limit_type = limit_type;
3357 		rack->r_ctl.rc_num_split_allocs++;
3358 	}
3359 	return (rsm);
3360 }
3361 
3362 static void
3363 rack_free_trim(struct tcp_rack *rack)
3364 {
3365 	struct rack_sendmap *rsm;
3366 
3367 	/*
3368 	 * Free up all the tail entries until
3369 	 * we get our list down to the limit.
3370 	 */
3371 	while (rack->rc_free_cnt > rack_free_cache) {
3372 		rsm = TAILQ_LAST(&rack->r_ctl.rc_free, rack_head);
3373 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
3374 		rack->rc_free_cnt--;
3375 		rack->r_ctl.rc_num_maps_alloced--;
3376 		uma_zfree(rack_zone, rsm);
3377 	}
3378 }
3379 
3380 static void
3381 rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm)
3382 {
3383 	if (rsm->r_flags & RACK_APP_LIMITED) {
3384 		if (rack->r_ctl.rc_app_limited_cnt > 0) {
3385 			rack->r_ctl.rc_app_limited_cnt--;
3386 		}
3387 	}
3388 	if (rsm->r_limit_type) {
3389 		/* currently there is only one limit type */
3390 		rack->r_ctl.rc_num_split_allocs--;
3391 	}
3392 	if (rsm == rack->r_ctl.rc_first_appl) {
3393 		if (rack->r_ctl.rc_app_limited_cnt == 0)
3394 			rack->r_ctl.rc_first_appl = NULL;
3395 		else
3396 			rack->r_ctl.rc_first_appl = tqhash_find(rack->r_ctl.tqh, rsm->r_nseq_appl);
3397 	}
3398 	if (rsm == rack->r_ctl.rc_resend)
3399 		rack->r_ctl.rc_resend = NULL;
3400 	if (rsm == rack->r_ctl.rc_end_appl)
3401 		rack->r_ctl.rc_end_appl = NULL;
3402 	if (rack->r_ctl.rc_tlpsend == rsm)
3403 		rack->r_ctl.rc_tlpsend = NULL;
3404 	if (rack->r_ctl.rc_sacklast == rsm)
3405 		rack->r_ctl.rc_sacklast = NULL;
3406 	memset(rsm, 0, sizeof(struct rack_sendmap));
3407 	/* Make sure we are not going to overrun our count limit of 0xff */
3408 	if ((rack->rc_free_cnt + 1) > 0xff) {
3409 		rack_free_trim(rack);
3410 	}
3411 	TAILQ_INSERT_HEAD(&rack->r_ctl.rc_free, rsm, r_tnext);
3412 	rack->rc_free_cnt++;
3413 }
3414 
3415 static uint32_t
3416 rack_get_measure_window(struct tcpcb *tp, struct tcp_rack *rack)
3417 {
3418 	uint64_t srtt, bw, len, tim;
3419 	uint32_t segsiz, def_len, minl;
3420 
3421 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
3422 	def_len = rack_def_data_window * segsiz;
3423 	if (rack->rc_gp_filled == 0) {
3424 		/*
3425 		 * We have no measurement (IW is in flight?) so
3426 		 * we can only guess using our data_window sysctl
3427 		 * value (usually 20MSS).
3428 		 */
3429 		return (def_len);
3430 	}
3431 	/*
3432 	 * Now we have a number of factors to consider.
3433 	 *
3434 	 * 1) We have a desired BDP which is usually
3435 	 *    at least 2.
3436 	 * 2) We have a minimum number of rtt's usually 1 SRTT
3437 	 *    but we allow it too to be more.
3438 	 * 3) We want to make sure a measurement last N useconds (if
3439 	 *    we have set rack_min_measure_usec.
3440 	 *
3441 	 * We handle the first concern here by trying to create a data
3442 	 * window of max(rack_def_data_window, DesiredBDP). The
3443 	 * second concern we handle in not letting the measurement
3444 	 * window end normally until at least the required SRTT's
3445 	 * have gone by which is done further below in
3446 	 * rack_enough_for_measurement(). Finally the third concern
3447 	 * we also handle here by calculating how long that time
3448 	 * would take at the current BW and then return the
3449 	 * max of our first calculation and that length. Note
3450 	 * that if rack_min_measure_usec is 0, we don't deal
3451 	 * with concern 3. Also for both Concern 1 and 3 an
3452 	 * application limited period could end the measurement
3453 	 * earlier.
3454 	 *
3455 	 * So lets calculate the BDP with the "known" b/w using
3456 	 * the SRTT has our rtt and then multiply it by the
3457 	 * goal.
3458 	 */
3459 	bw = rack_get_bw(rack);
3460 	srtt = (uint64_t)tp->t_srtt;
3461 	len = bw * srtt;
3462 	len /= (uint64_t)HPTS_USEC_IN_SEC;
3463 	len *= max(1, rack_goal_bdp);
3464 	/* Now we need to round up to the nearest MSS */
3465 	len = roundup(len, segsiz);
3466 	if (rack_min_measure_usec) {
3467 		/* Now calculate our min length for this b/w */
3468 		tim = rack_min_measure_usec;
3469 		minl = (tim * bw) / (uint64_t)HPTS_USEC_IN_SEC;
3470 		if (minl == 0)
3471 			minl = 1;
3472 		minl = roundup(minl, segsiz);
3473 		if (len < minl)
3474 			len = minl;
3475 	}
3476 	/*
3477 	 * Now if we have a very small window we want
3478 	 * to attempt to get the window that is
3479 	 * as small as possible. This happens on
3480 	 * low b/w connections and we don't want to
3481 	 * span huge numbers of rtt's between measurements.
3482 	 *
3483 	 * We basically include 2 over our "MIN window" so
3484 	 * that the measurement can be shortened (possibly) by
3485 	 * an ack'ed packet.
3486 	 */
3487 	if (len < def_len)
3488 		return (max((uint32_t)len, ((MIN_GP_WIN+2) * segsiz)));
3489 	else
3490 		return (max((uint32_t)len, def_len));
3491 
3492 }
3493 
3494 static int
3495 rack_enough_for_measurement(struct tcpcb *tp, struct tcp_rack *rack, tcp_seq th_ack, uint8_t *quality)
3496 {
3497 	uint32_t tim, srtts, segsiz;
3498 
3499 	/*
3500 	 * Has enough time passed for the GP measurement to be valid?
3501 	 */
3502 	if (SEQ_LT(th_ack, tp->gput_seq)) {
3503 		/* Not enough bytes yet */
3504 		return (0);
3505 	}
3506 	if ((tp->snd_max == tp->snd_una) ||
3507 	    (th_ack == tp->snd_max)){
3508 		/*
3509 		 * All is acked quality of all acked is
3510 		 * usually low or medium, but we in theory could split
3511 		 * all acked into two cases, where you got
3512 		 * a signifigant amount of your window and
3513 		 * where you did not. For now we leave it
3514 		 * but it is something to contemplate in the
3515 		 * future. The danger here is that delayed ack
3516 		 * is effecting the last byte (which is a 50:50 chance).
3517 		 */
3518 		*quality = RACK_QUALITY_ALLACKED;
3519 		return (1);
3520 	}
3521 	if (SEQ_GEQ(th_ack,  tp->gput_ack)) {
3522 		/*
3523 		 * We obtained our entire window of data we wanted
3524 		 * no matter if we are in recovery or not then
3525 		 * its ok since expanding the window does not
3526 		 * make things fuzzy (or at least not as much).
3527 		 */
3528 		*quality = RACK_QUALITY_HIGH;
3529 		return (1);
3530 	}
3531 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
3532 	if (SEQ_LT(th_ack, tp->gput_ack) &&
3533 	    ((th_ack - tp->gput_seq) < max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
3534 		/* Not enough bytes yet */
3535 		return (0);
3536 	}
3537 	if (rack->r_ctl.rc_first_appl &&
3538 	    (SEQ_GEQ(th_ack, rack->r_ctl.rc_first_appl->r_end))) {
3539 		/*
3540 		 * We are up to the app limited send point
3541 		 * we have to measure irrespective of the time..
3542 		 */
3543 		*quality = RACK_QUALITY_APPLIMITED;
3544 		return (1);
3545 	}
3546 	/* Now what about time? */
3547 	srtts = (rack->r_ctl.rc_gp_srtt * rack_min_srtts);
3548 	tim = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - tp->gput_ts;
3549 	if ((tim >= srtts) && (IN_RECOVERY(rack->rc_tp->t_flags) == 0)) {
3550 		/*
3551 		 * We do not allow a measurement if we are in recovery
3552 		 * that would shrink the goodput window we wanted.
3553 		 * This is to prevent cloudyness of when the last send
3554 		 * was actually made.
3555 		 */
3556 		*quality = RACK_QUALITY_HIGH;
3557 		return (1);
3558 	}
3559 	/* Nope not even a full SRTT has passed */
3560 	return (0);
3561 }
3562 
3563 static void
3564 rack_log_timely(struct tcp_rack *rack,
3565 		uint32_t logged, uint64_t cur_bw, uint64_t low_bnd,
3566 		uint64_t up_bnd, int line, uint8_t method)
3567 {
3568 	if (tcp_bblogging_on(rack->rc_tp)) {
3569 		union tcp_log_stackspecific log;
3570 		struct timeval tv;
3571 
3572 		memset(&log, 0, sizeof(log));
3573 		log.u_bbr.flex1 = logged;
3574 		log.u_bbr.flex2 = rack->rc_gp_timely_inc_cnt;
3575 		log.u_bbr.flex2 <<= 4;
3576 		log.u_bbr.flex2 |= rack->rc_gp_timely_dec_cnt;
3577 		log.u_bbr.flex2 <<= 4;
3578 		log.u_bbr.flex2 |= rack->rc_gp_incr;
3579 		log.u_bbr.flex2 <<= 4;
3580 		log.u_bbr.flex2 |= rack->rc_gp_bwred;
3581 		log.u_bbr.flex3 = rack->rc_gp_incr;
3582 		log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
3583 		log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ca;
3584 		log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_rec;
3585 		log.u_bbr.flex7 = rack->rc_gp_bwred;
3586 		log.u_bbr.flex8 = method;
3587 		log.u_bbr.cur_del_rate = cur_bw;
3588 		log.u_bbr.delRate = low_bnd;
3589 		log.u_bbr.bw_inuse = up_bnd;
3590 		log.u_bbr.rttProp = rack_get_bw(rack);
3591 		log.u_bbr.pkt_epoch = line;
3592 		log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
3593 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3594 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3595 		log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
3596 		log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
3597 		log.u_bbr.cwnd_gain = rack->rc_dragged_bottom;
3598 		log.u_bbr.cwnd_gain <<= 1;
3599 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_rec;
3600 		log.u_bbr.cwnd_gain <<= 1;
3601 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
3602 		log.u_bbr.cwnd_gain <<= 1;
3603 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
3604 		log.u_bbr.lost = rack->r_ctl.rc_loss_count;
3605 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3606 		    &rack->rc_inp->inp_socket->so_rcv,
3607 		    &rack->rc_inp->inp_socket->so_snd,
3608 		    TCP_TIMELY_WORK, 0,
3609 		    0, &log, false, &tv);
3610 	}
3611 }
3612 
3613 static int
3614 rack_bw_can_be_raised(struct tcp_rack *rack, uint64_t cur_bw, uint64_t last_bw_est, uint16_t mult)
3615 {
3616 	/*
3617 	 * Before we increase we need to know if
3618 	 * the estimate just made was less than
3619 	 * our pacing goal (i.e. (cur_bw * mult) > last_bw_est)
3620 	 *
3621 	 * If we already are pacing at a fast enough
3622 	 * rate to push us faster there is no sense of
3623 	 * increasing.
3624 	 *
3625 	 * We first caculate our actual pacing rate (ss or ca multiplier
3626 	 * times our cur_bw).
3627 	 *
3628 	 * Then we take the last measured rate and multipy by our
3629 	 * maximum pacing overage to give us a max allowable rate.
3630 	 *
3631 	 * If our act_rate is smaller than our max_allowable rate
3632 	 * then we should increase. Else we should hold steady.
3633 	 *
3634 	 */
3635 	uint64_t act_rate, max_allow_rate;
3636 
3637 	if (rack_timely_no_stopping)
3638 		return (1);
3639 
3640 	if ((cur_bw == 0) || (last_bw_est == 0)) {
3641 		/*
3642 		 * Initial startup case or
3643 		 * everything is acked case.
3644 		 */
3645 		rack_log_timely(rack,  mult, cur_bw, 0, 0,
3646 				__LINE__, 9);
3647 		return (1);
3648 	}
3649 	if (mult <= 100) {
3650 		/*
3651 		 * We can always pace at or slightly above our rate.
3652 		 */
3653 		rack_log_timely(rack,  mult, cur_bw, 0, 0,
3654 				__LINE__, 9);
3655 		return (1);
3656 	}
3657 	act_rate = cur_bw * (uint64_t)mult;
3658 	act_rate /= 100;
3659 	max_allow_rate = last_bw_est * ((uint64_t)rack_max_per_above + (uint64_t)100);
3660 	max_allow_rate /= 100;
3661 	if (act_rate < max_allow_rate) {
3662 		/*
3663 		 * Here the rate we are actually pacing at
3664 		 * is smaller than 10% above our last measurement.
3665 		 * This means we are pacing below what we would
3666 		 * like to try to achieve (plus some wiggle room).
3667 		 */
3668 		rack_log_timely(rack,  mult, cur_bw, act_rate, max_allow_rate,
3669 				__LINE__, 9);
3670 		return (1);
3671 	} else {
3672 		/*
3673 		 * Here we are already pacing at least rack_max_per_above(10%)
3674 		 * what we are getting back. This indicates most likely
3675 		 * that we are being limited (cwnd/rwnd/app) and can't
3676 		 * get any more b/w. There is no sense of trying to
3677 		 * raise up the pacing rate its not speeding us up
3678 		 * and we already are pacing faster than we are getting.
3679 		 */
3680 		rack_log_timely(rack,  mult, cur_bw, act_rate, max_allow_rate,
3681 				__LINE__, 8);
3682 		return (0);
3683 	}
3684 }
3685 
3686 static void
3687 rack_validate_multipliers_at_or_above100(struct tcp_rack *rack)
3688 {
3689 	/*
3690 	 * When we drag bottom, we want to assure
3691 	 * that no multiplier is below 1.0, if so
3692 	 * we want to restore it to at least that.
3693 	 */
3694 	if (rack->r_ctl.rack_per_of_gp_rec  < 100) {
3695 		/* This is unlikely we usually do not touch recovery */
3696 		rack->r_ctl.rack_per_of_gp_rec = 100;
3697 	}
3698 	if (rack->r_ctl.rack_per_of_gp_ca < 100) {
3699 		rack->r_ctl.rack_per_of_gp_ca = 100;
3700 	}
3701 	if (rack->r_ctl.rack_per_of_gp_ss < 100) {
3702 		rack->r_ctl.rack_per_of_gp_ss = 100;
3703 	}
3704 }
3705 
3706 static void
3707 rack_validate_multipliers_at_or_below_100(struct tcp_rack *rack)
3708 {
3709 	if (rack->r_ctl.rack_per_of_gp_ca > 100) {
3710 		rack->r_ctl.rack_per_of_gp_ca = 100;
3711 	}
3712 	if (rack->r_ctl.rack_per_of_gp_ss > 100) {
3713 		rack->r_ctl.rack_per_of_gp_ss = 100;
3714 	}
3715 }
3716 
3717 static void
3718 rack_increase_bw_mul(struct tcp_rack *rack, int timely_says, uint64_t cur_bw, uint64_t last_bw_est, int override)
3719 {
3720 	int32_t  calc, logged, plus;
3721 
3722 	logged = 0;
3723 
3724 	if (override) {
3725 		/*
3726 		 * override is passed when we are
3727 		 * loosing b/w and making one last
3728 		 * gasp at trying to not loose out
3729 		 * to a new-reno flow.
3730 		 */
3731 		goto extra_boost;
3732 	}
3733 	/* In classic timely we boost by 5x if we have 5 increases in a row, lets not */
3734 	if (rack->rc_gp_incr &&
3735 	    ((rack->rc_gp_timely_inc_cnt + 1) >= RACK_TIMELY_CNT_BOOST)) {
3736 		/*
3737 		 * Reset and get 5 strokes more before the boost. Note
3738 		 * that the count is 0 based so we have to add one.
3739 		 */
3740 extra_boost:
3741 		plus = (uint32_t)rack_gp_increase_per * RACK_TIMELY_CNT_BOOST;
3742 		rack->rc_gp_timely_inc_cnt = 0;
3743 	} else
3744 		plus = (uint32_t)rack_gp_increase_per;
3745 	/* Must be at least 1% increase for true timely increases */
3746 	if ((plus < 1) &&
3747 	    ((rack->r_ctl.rc_rtt_diff <= 0) || (timely_says <= 0)))
3748 		plus = 1;
3749 	if (rack->rc_gp_saw_rec &&
3750 	    (rack->rc_gp_no_rec_chg == 0) &&
3751 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3752 				  rack->r_ctl.rack_per_of_gp_rec)) {
3753 		/* We have been in recovery ding it too */
3754 		calc = rack->r_ctl.rack_per_of_gp_rec + plus;
3755 		if (calc > 0xffff)
3756 			calc = 0xffff;
3757 		logged |= 1;
3758 		rack->r_ctl.rack_per_of_gp_rec = (uint16_t)calc;
3759 		if (rack->r_ctl.rack_per_upper_bound_ca &&
3760 		    (rack->rc_dragged_bottom == 0) &&
3761 		    (rack->r_ctl.rack_per_of_gp_rec > rack->r_ctl.rack_per_upper_bound_ca))
3762 			rack->r_ctl.rack_per_of_gp_rec = rack->r_ctl.rack_per_upper_bound_ca;
3763 	}
3764 	if (rack->rc_gp_saw_ca &&
3765 	    (rack->rc_gp_saw_ss == 0) &&
3766 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3767 				  rack->r_ctl.rack_per_of_gp_ca)) {
3768 		/* In CA */
3769 		calc = rack->r_ctl.rack_per_of_gp_ca + plus;
3770 		if (calc > 0xffff)
3771 			calc = 0xffff;
3772 		logged |= 2;
3773 		rack->r_ctl.rack_per_of_gp_ca = (uint16_t)calc;
3774 		if (rack->r_ctl.rack_per_upper_bound_ca &&
3775 		    (rack->rc_dragged_bottom == 0) &&
3776 		    (rack->r_ctl.rack_per_of_gp_ca > rack->r_ctl.rack_per_upper_bound_ca))
3777 			rack->r_ctl.rack_per_of_gp_ca = rack->r_ctl.rack_per_upper_bound_ca;
3778 	}
3779 	if (rack->rc_gp_saw_ss &&
3780 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3781 				  rack->r_ctl.rack_per_of_gp_ss)) {
3782 		/* In SS */
3783 		calc = rack->r_ctl.rack_per_of_gp_ss + plus;
3784 		if (calc > 0xffff)
3785 			calc = 0xffff;
3786 		rack->r_ctl.rack_per_of_gp_ss = (uint16_t)calc;
3787 		if (rack->r_ctl.rack_per_upper_bound_ss &&
3788 		    (rack->rc_dragged_bottom == 0) &&
3789 		    (rack->r_ctl.rack_per_of_gp_ss > rack->r_ctl.rack_per_upper_bound_ss))
3790 			rack->r_ctl.rack_per_of_gp_ss = rack->r_ctl.rack_per_upper_bound_ss;
3791 		logged |= 4;
3792 	}
3793 	if (logged &&
3794 	    (rack->rc_gp_incr == 0)){
3795 		/* Go into increment mode */
3796 		rack->rc_gp_incr = 1;
3797 		rack->rc_gp_timely_inc_cnt = 0;
3798 	}
3799 	if (rack->rc_gp_incr &&
3800 	    logged &&
3801 	    (rack->rc_gp_timely_inc_cnt < RACK_TIMELY_CNT_BOOST)) {
3802 		rack->rc_gp_timely_inc_cnt++;
3803 	}
3804 	rack_log_timely(rack,  logged, plus, 0, 0,
3805 			__LINE__, 1);
3806 }
3807 
3808 static uint32_t
3809 rack_get_decrease(struct tcp_rack *rack, uint32_t curper, int32_t rtt_diff)
3810 {
3811 	/*
3812 	 * norm_grad = rtt_diff / minrtt;
3813 	 * new_per = curper * (1 - B * norm_grad)
3814 	 *
3815 	 * B = rack_gp_decrease_per (default 10%)
3816 	 * rtt_dif = input var current rtt-diff
3817 	 * curper = input var current percentage
3818 	 * minrtt = from rack filter
3819 	 *
3820 	 */
3821 	uint64_t perf;
3822 
3823 	perf = (((uint64_t)curper * ((uint64_t)1000000 -
3824 		    ((uint64_t)rack_gp_decrease_per * (uint64_t)10000 *
3825 		     (((uint64_t)rtt_diff * (uint64_t)1000000)/
3826 		      (uint64_t)get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt)))/
3827 		     (uint64_t)1000000)) /
3828 		(uint64_t)1000000);
3829 	if (perf > curper) {
3830 		/* TSNH */
3831 		perf = curper - 1;
3832 	}
3833 	return ((uint32_t)perf);
3834 }
3835 
3836 static uint32_t
3837 rack_decrease_highrtt(struct tcp_rack *rack, uint32_t curper, uint32_t rtt)
3838 {
3839 	/*
3840 	 *                                   highrttthresh
3841 	 * result = curper * (1 - (B * ( 1 -  ------          ))
3842 	 *                                     gp_srtt
3843 	 *
3844 	 * B = rack_gp_decrease_per (default 10%)
3845 	 * highrttthresh = filter_min * rack_gp_rtt_maxmul
3846 	 */
3847 	uint64_t perf;
3848 	uint32_t highrttthresh;
3849 
3850 	highrttthresh = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
3851 
3852 	perf = (((uint64_t)curper * ((uint64_t)1000000 -
3853 				     ((uint64_t)rack_gp_decrease_per * ((uint64_t)1000000 -
3854 					((uint64_t)highrttthresh * (uint64_t)1000000) /
3855 						    (uint64_t)rtt)) / 100)) /(uint64_t)1000000);
3856 	return (perf);
3857 }
3858 
3859 static void
3860 rack_decrease_bw_mul(struct tcp_rack *rack, int timely_says, uint32_t rtt, int32_t rtt_diff)
3861 {
3862 	uint64_t logvar, logvar2, logvar3;
3863 	uint32_t logged, new_per, ss_red, ca_red, rec_red, alt, val;
3864 
3865 	if (rack->rc_gp_incr) {
3866 		/* Turn off increment counting */
3867 		rack->rc_gp_incr = 0;
3868 		rack->rc_gp_timely_inc_cnt = 0;
3869 	}
3870 	ss_red = ca_red = rec_red = 0;
3871 	logged = 0;
3872 	/* Calculate the reduction value */
3873 	if (rtt_diff < 0) {
3874 		rtt_diff *= -1;
3875 	}
3876 	/* Must be at least 1% reduction */
3877 	if (rack->rc_gp_saw_rec && (rack->rc_gp_no_rec_chg == 0)) {
3878 		/* We have been in recovery ding it too */
3879 		if (timely_says == 2) {
3880 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_rec, rtt);
3881 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3882 			if (alt < new_per)
3883 				val = alt;
3884 			else
3885 				val = new_per;
3886 		} else
3887 			 val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3888 		if (rack->r_ctl.rack_per_of_gp_rec > val) {
3889 			rec_red = (rack->r_ctl.rack_per_of_gp_rec - val);
3890 			rack->r_ctl.rack_per_of_gp_rec = (uint16_t)val;
3891 		} else {
3892 			rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
3893 			rec_red = 0;
3894 		}
3895 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_rec)
3896 			rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
3897 		logged |= 1;
3898 	}
3899 	if (rack->rc_gp_saw_ss) {
3900 		/* Sent in SS */
3901 		if (timely_says == 2) {
3902 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ss, rtt);
3903 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3904 			if (alt < new_per)
3905 				val = alt;
3906 			else
3907 				val = new_per;
3908 		} else
3909 			val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ss, rtt_diff);
3910 		if (rack->r_ctl.rack_per_of_gp_ss > new_per) {
3911 			ss_red = rack->r_ctl.rack_per_of_gp_ss - val;
3912 			rack->r_ctl.rack_per_of_gp_ss = (uint16_t)val;
3913 		} else {
3914 			ss_red = new_per;
3915 			rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
3916 			logvar = new_per;
3917 			logvar <<= 32;
3918 			logvar |= alt;
3919 			logvar2 = (uint32_t)rtt;
3920 			logvar2 <<= 32;
3921 			logvar2 |= (uint32_t)rtt_diff;
3922 			logvar3 = rack_gp_rtt_maxmul;
3923 			logvar3 <<= 32;
3924 			logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3925 			rack_log_timely(rack, timely_says,
3926 					logvar2, logvar3,
3927 					logvar, __LINE__, 10);
3928 		}
3929 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ss)
3930 			rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
3931 		logged |= 4;
3932 	} else if (rack->rc_gp_saw_ca) {
3933 		/* Sent in CA */
3934 		if (timely_says == 2) {
3935 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ca, rtt);
3936 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3937 			if (alt < new_per)
3938 				val = alt;
3939 			else
3940 				val = new_per;
3941 		} else
3942 			val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ca, rtt_diff);
3943 		if (rack->r_ctl.rack_per_of_gp_ca > val) {
3944 			ca_red = rack->r_ctl.rack_per_of_gp_ca - val;
3945 			rack->r_ctl.rack_per_of_gp_ca = (uint16_t)val;
3946 		} else {
3947 			rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
3948 			ca_red = 0;
3949 			logvar = new_per;
3950 			logvar <<= 32;
3951 			logvar |= alt;
3952 			logvar2 = (uint32_t)rtt;
3953 			logvar2 <<= 32;
3954 			logvar2 |= (uint32_t)rtt_diff;
3955 			logvar3 = rack_gp_rtt_maxmul;
3956 			logvar3 <<= 32;
3957 			logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3958 			rack_log_timely(rack, timely_says,
3959 					logvar2, logvar3,
3960 					logvar, __LINE__, 10);
3961 		}
3962 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ca)
3963 			rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
3964 		logged |= 2;
3965 	}
3966 	if (rack->rc_gp_timely_dec_cnt < 0x7) {
3967 		rack->rc_gp_timely_dec_cnt++;
3968 		if (rack_timely_dec_clear &&
3969 		    (rack->rc_gp_timely_dec_cnt == rack_timely_dec_clear))
3970 			rack->rc_gp_timely_dec_cnt = 0;
3971 	}
3972 	logvar = ss_red;
3973 	logvar <<= 32;
3974 	logvar |= ca_red;
3975 	rack_log_timely(rack,  logged, rec_red, rack_per_lower_bound, logvar,
3976 			__LINE__, 2);
3977 }
3978 
3979 static void
3980 rack_log_rtt_shrinks(struct tcp_rack *rack, uint32_t us_cts,
3981 		     uint32_t rtt, uint32_t line, uint8_t reas)
3982 {
3983 	if (tcp_bblogging_on(rack->rc_tp)) {
3984 		union tcp_log_stackspecific log;
3985 		struct timeval tv;
3986 
3987 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3988 		log.u_bbr.flex1 = line;
3989 		log.u_bbr.flex2 = rack->r_ctl.rc_time_probertt_starts;
3990 		log.u_bbr.flex3 = rack->r_ctl.rc_lower_rtt_us_cts;
3991 		log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
3992 		log.u_bbr.flex5 = rtt;
3993 		log.u_bbr.flex6 = rack->rc_highly_buffered;
3994 		log.u_bbr.flex6 <<= 1;
3995 		log.u_bbr.flex6 |= rack->forced_ack;
3996 		log.u_bbr.flex6 <<= 1;
3997 		log.u_bbr.flex6 |= rack->rc_gp_dyn_mul;
3998 		log.u_bbr.flex6 <<= 1;
3999 		log.u_bbr.flex6 |= rack->in_probe_rtt;
4000 		log.u_bbr.flex6 <<= 1;
4001 		log.u_bbr.flex6 |= rack->measure_saw_probe_rtt;
4002 		log.u_bbr.flex7 = rack->r_ctl.rack_per_of_gp_probertt;
4003 		log.u_bbr.pacing_gain = rack->r_ctl.rack_per_of_gp_ca;
4004 		log.u_bbr.cwnd_gain = rack->r_ctl.rack_per_of_gp_rec;
4005 		log.u_bbr.flex8 = reas;
4006 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
4007 		log.u_bbr.delRate = rack_get_bw(rack);
4008 		log.u_bbr.cur_del_rate = rack->r_ctl.rc_highest_us_rtt;
4009 		log.u_bbr.cur_del_rate <<= 32;
4010 		log.u_bbr.cur_del_rate |= rack->r_ctl.rc_lowest_us_rtt;
4011 		log.u_bbr.applimited = rack->r_ctl.rc_time_probertt_entered;
4012 		log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
4013 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
4014 		log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
4015 		log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
4016 		log.u_bbr.pkt_epoch = rack->r_ctl.rc_lower_rtt_us_cts;
4017 		log.u_bbr.delivered = rack->r_ctl.rc_target_probertt_flight;
4018 		log.u_bbr.lost = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
4019 		log.u_bbr.rttProp = us_cts;
4020 		log.u_bbr.rttProp <<= 32;
4021 		log.u_bbr.rttProp |= rack->r_ctl.rc_entry_gp_rtt;
4022 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
4023 		    &rack->rc_inp->inp_socket->so_rcv,
4024 		    &rack->rc_inp->inp_socket->so_snd,
4025 		    BBR_LOG_RTT_SHRINKS, 0,
4026 		    0, &log, false, &rack->r_ctl.act_rcv_time);
4027 	}
4028 }
4029 
4030 static void
4031 rack_set_prtt_target(struct tcp_rack *rack, uint32_t segsiz, uint32_t rtt)
4032 {
4033 	uint64_t bwdp;
4034 
4035 	bwdp = rack_get_bw(rack);
4036 	bwdp *= (uint64_t)rtt;
4037 	bwdp /= (uint64_t)HPTS_USEC_IN_SEC;
4038 	rack->r_ctl.rc_target_probertt_flight = roundup((uint32_t)bwdp, segsiz);
4039 	if (rack->r_ctl.rc_target_probertt_flight < (segsiz * rack_timely_min_segs)) {
4040 		/*
4041 		 * A window protocol must be able to have 4 packets
4042 		 * outstanding as the floor in order to function
4043 		 * (especially considering delayed ack :D).
4044 		 */
4045 		rack->r_ctl.rc_target_probertt_flight = (segsiz * rack_timely_min_segs);
4046 	}
4047 }
4048 
4049 static void
4050 rack_enter_probertt(struct tcp_rack *rack, uint32_t us_cts)
4051 {
4052 	/**
4053 	 * ProbeRTT is a bit different in rack_pacing than in
4054 	 * BBR. It is like BBR in that it uses the lowering of
4055 	 * the RTT as a signal that we saw something new and
4056 	 * counts from there for how long between. But it is
4057 	 * different in that its quite simple. It does not
4058 	 * play with the cwnd and wait until we get down
4059 	 * to N segments outstanding and hold that for
4060 	 * 200ms. Instead it just sets the pacing reduction
4061 	 * rate to a set percentage (70 by default) and hold
4062 	 * that for a number of recent GP Srtt's.
4063 	 */
4064 	uint32_t segsiz;
4065 
4066 	if (rack->rc_gp_dyn_mul == 0)
4067 		return;
4068 
4069 	if (rack->rc_tp->snd_max == rack->rc_tp->snd_una) {
4070 		/* We are idle */
4071 		return;
4072 	}
4073 	if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
4074 	    SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
4075 		/*
4076 		 * Stop the goodput now, the idea here is
4077 		 * that future measurements with in_probe_rtt
4078 		 * won't register if they are not greater so
4079 		 * we want to get what info (if any) is available
4080 		 * now.
4081 		 */
4082 		rack_do_goodput_measurement(rack->rc_tp, rack,
4083 					    rack->rc_tp->snd_una, __LINE__,
4084 					    RACK_QUALITY_PROBERTT);
4085 	}
4086 	rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
4087 	rack->r_ctl.rc_time_probertt_entered = us_cts;
4088 	segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
4089 		     rack->r_ctl.rc_pace_min_segs);
4090 	rack->in_probe_rtt = 1;
4091 	rack->measure_saw_probe_rtt = 1;
4092 	rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
4093 	rack->r_ctl.rc_time_probertt_starts = 0;
4094 	rack->r_ctl.rc_entry_gp_rtt = rack->r_ctl.rc_gp_srtt;
4095 	if (rack_probertt_use_min_rtt_entry)
4096 		rack_set_prtt_target(rack, segsiz, get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
4097 	else
4098 		rack_set_prtt_target(rack, segsiz, rack->r_ctl.rc_gp_srtt);
4099 	rack_log_rtt_shrinks(rack,  us_cts,  get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4100 			     __LINE__, RACK_RTTS_ENTERPROBE);
4101 }
4102 
4103 static void
4104 rack_exit_probertt(struct tcp_rack *rack, uint32_t us_cts)
4105 {
4106 	struct rack_sendmap *rsm;
4107 	uint32_t segsiz;
4108 
4109 	segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
4110 		     rack->r_ctl.rc_pace_min_segs);
4111 	rack->in_probe_rtt = 0;
4112 	if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
4113 	    SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
4114 		/*
4115 		 * Stop the goodput now, the idea here is
4116 		 * that future measurements with in_probe_rtt
4117 		 * won't register if they are not greater so
4118 		 * we want to get what info (if any) is available
4119 		 * now.
4120 		 */
4121 		rack_do_goodput_measurement(rack->rc_tp, rack,
4122 					    rack->rc_tp->snd_una, __LINE__,
4123 					    RACK_QUALITY_PROBERTT);
4124 	} else if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
4125 		/*
4126 		 * We don't have enough data to make a measurement.
4127 		 * So lets just stop and start here after exiting
4128 		 * probe-rtt. We probably are not interested in
4129 		 * the results anyway.
4130 		 */
4131 		rack->rc_tp->t_flags &= ~TF_GPUTINPROG;
4132 	}
4133 	/*
4134 	 * Measurements through the current snd_max are going
4135 	 * to be limited by the slower pacing rate.
4136 	 *
4137 	 * We need to mark these as app-limited so we
4138 	 * don't collapse the b/w.
4139 	 */
4140 	rsm = tqhash_max(rack->r_ctl.tqh);
4141 	if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
4142 		if (rack->r_ctl.rc_app_limited_cnt == 0)
4143 			rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
4144 		else {
4145 			/*
4146 			 * Go out to the end app limited and mark
4147 			 * this new one as next and move the end_appl up
4148 			 * to this guy.
4149 			 */
4150 			if (rack->r_ctl.rc_end_appl)
4151 				rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
4152 			rack->r_ctl.rc_end_appl = rsm;
4153 		}
4154 		rsm->r_flags |= RACK_APP_LIMITED;
4155 		rack->r_ctl.rc_app_limited_cnt++;
4156 	}
4157 	/*
4158 	 * Now, we need to examine our pacing rate multipliers.
4159 	 * If its under 100%, we need to kick it back up to
4160 	 * 100%. We also don't let it be over our "max" above
4161 	 * the actual rate i.e. 100% + rack_clamp_atexit_prtt.
4162 	 * Note setting clamp_atexit_prtt to 0 has the effect
4163 	 * of setting CA/SS to 100% always at exit (which is
4164 	 * the default behavior).
4165 	 */
4166 	if (rack_probertt_clear_is) {
4167 		rack->rc_gp_incr = 0;
4168 		rack->rc_gp_bwred = 0;
4169 		rack->rc_gp_timely_inc_cnt = 0;
4170 		rack->rc_gp_timely_dec_cnt = 0;
4171 	}
4172 	/* Do we do any clamping at exit? */
4173 	if (rack->rc_highly_buffered && rack_atexit_prtt_hbp) {
4174 		rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt_hbp;
4175 		rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt_hbp;
4176 	}
4177 	if ((rack->rc_highly_buffered == 0) && rack_atexit_prtt) {
4178 		rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt;
4179 		rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt;
4180 	}
4181 	/*
4182 	 * Lets set rtt_diff to 0, so that we will get a "boost"
4183 	 * after exiting.
4184 	 */
4185 	rack->r_ctl.rc_rtt_diff = 0;
4186 
4187 	/* Clear all flags so we start fresh */
4188 	rack->rc_tp->t_bytes_acked = 0;
4189 	rack->rc_tp->t_ccv.flags &= ~CCF_ABC_SENTAWND;
4190 	/*
4191 	 * If configured to, set the cwnd and ssthresh to
4192 	 * our targets.
4193 	 */
4194 	if (rack_probe_rtt_sets_cwnd) {
4195 		uint64_t ebdp;
4196 		uint32_t setto;
4197 
4198 		/* Set ssthresh so we get into CA once we hit our target */
4199 		if (rack_probertt_use_min_rtt_exit == 1) {
4200 			/* Set to min rtt */
4201 			rack_set_prtt_target(rack, segsiz,
4202 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
4203 		} else if (rack_probertt_use_min_rtt_exit == 2) {
4204 			/* Set to current gp rtt */
4205 			rack_set_prtt_target(rack, segsiz,
4206 					     rack->r_ctl.rc_gp_srtt);
4207 		} else if (rack_probertt_use_min_rtt_exit == 3) {
4208 			/* Set to entry gp rtt */
4209 			rack_set_prtt_target(rack, segsiz,
4210 					     rack->r_ctl.rc_entry_gp_rtt);
4211 		} else {
4212 			uint64_t sum;
4213 			uint32_t setval;
4214 
4215 			sum = rack->r_ctl.rc_entry_gp_rtt;
4216 			sum *= 10;
4217 			sum /= (uint64_t)(max(1, rack->r_ctl.rc_gp_srtt));
4218 			if (sum >= 20) {
4219 				/*
4220 				 * A highly buffered path needs
4221 				 * cwnd space for timely to work.
4222 				 * Lets set things up as if
4223 				 * we are heading back here again.
4224 				 */
4225 				setval = rack->r_ctl.rc_entry_gp_rtt;
4226 			} else if (sum >= 15) {
4227 				/*
4228 				 * Lets take the smaller of the
4229 				 * two since we are just somewhat
4230 				 * buffered.
4231 				 */
4232 				setval = rack->r_ctl.rc_gp_srtt;
4233 				if (setval > rack->r_ctl.rc_entry_gp_rtt)
4234 					setval = rack->r_ctl.rc_entry_gp_rtt;
4235 			} else {
4236 				/*
4237 				 * Here we are not highly buffered
4238 				 * and should pick the min we can to
4239 				 * keep from causing loss.
4240 				 */
4241 				setval = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
4242 			}
4243 			rack_set_prtt_target(rack, segsiz,
4244 					     setval);
4245 		}
4246 		if (rack_probe_rtt_sets_cwnd > 1) {
4247 			/* There is a percentage here to boost */
4248 			ebdp = rack->r_ctl.rc_target_probertt_flight;
4249 			ebdp *= rack_probe_rtt_sets_cwnd;
4250 			ebdp /= 100;
4251 			setto = rack->r_ctl.rc_target_probertt_flight + ebdp;
4252 		} else
4253 			setto = rack->r_ctl.rc_target_probertt_flight;
4254 		rack->rc_tp->snd_cwnd = roundup(setto, segsiz);
4255 		if (rack->rc_tp->snd_cwnd < (segsiz * rack_timely_min_segs)) {
4256 			/* Enforce a min */
4257 			rack->rc_tp->snd_cwnd = segsiz * rack_timely_min_segs;
4258 		}
4259 		/* If we set in the cwnd also set the ssthresh point so we are in CA */
4260 		rack->rc_tp->snd_ssthresh = (rack->rc_tp->snd_cwnd - 1);
4261 	}
4262 	rack_log_rtt_shrinks(rack,  us_cts,
4263 			     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4264 			     __LINE__, RACK_RTTS_EXITPROBE);
4265 	/* Clear times last so log has all the info */
4266 	rack->r_ctl.rc_probertt_sndmax_atexit = rack->rc_tp->snd_max;
4267 	rack->r_ctl.rc_time_probertt_entered = us_cts;
4268 	rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
4269 	rack->r_ctl.rc_time_of_last_probertt = us_cts;
4270 }
4271 
4272 static void
4273 rack_check_probe_rtt(struct tcp_rack *rack, uint32_t us_cts)
4274 {
4275 	/* Check in on probe-rtt */
4276 	if (rack->rc_gp_filled == 0) {
4277 		/* We do not do p-rtt unless we have gp measurements */
4278 		return;
4279 	}
4280 	if (rack->in_probe_rtt) {
4281 		uint64_t no_overflow;
4282 		uint32_t endtime, must_stay;
4283 
4284 		if (rack->r_ctl.rc_went_idle_time &&
4285 		    ((us_cts - rack->r_ctl.rc_went_idle_time) > rack_min_probertt_hold)) {
4286 			/*
4287 			 * We went idle during prtt, just exit now.
4288 			 */
4289 			rack_exit_probertt(rack, us_cts);
4290 		} else if (rack_probe_rtt_safety_val &&
4291 		    TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered) &&
4292 		    ((us_cts - rack->r_ctl.rc_time_probertt_entered) > rack_probe_rtt_safety_val)) {
4293 			/*
4294 			 * Probe RTT safety value triggered!
4295 			 */
4296 			rack_log_rtt_shrinks(rack,  us_cts,
4297 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4298 					     __LINE__, RACK_RTTS_SAFETY);
4299 			rack_exit_probertt(rack, us_cts);
4300 		}
4301 		/* Calculate the max we will wait */
4302 		endtime = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_max_drain_wait);
4303 		if (rack->rc_highly_buffered)
4304 			endtime += (rack->r_ctl.rc_gp_srtt * rack_max_drain_hbp);
4305 		/* Calculate the min we must wait */
4306 		must_stay = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_must_drain);
4307 		if ((ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.rc_target_probertt_flight) &&
4308 		    TSTMP_LT(us_cts, endtime)) {
4309 			uint32_t calc;
4310 			/* Do we lower more? */
4311 no_exit:
4312 			if (TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered))
4313 				calc = us_cts - rack->r_ctl.rc_time_probertt_entered;
4314 			else
4315 				calc = 0;
4316 			calc /= max(rack->r_ctl.rc_gp_srtt, 1);
4317 			if (calc) {
4318 				/* Maybe */
4319 				calc *= rack_per_of_gp_probertt_reduce;
4320 				rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt - calc;
4321 				/* Limit it too */
4322 				if (rack->r_ctl.rack_per_of_gp_probertt < rack_per_of_gp_lowthresh)
4323 					rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_lowthresh;
4324 			}
4325 			/* We must reach target or the time set */
4326 			return;
4327 		}
4328 		if (rack->r_ctl.rc_time_probertt_starts == 0) {
4329 			if ((TSTMP_LT(us_cts, must_stay) &&
4330 			     rack->rc_highly_buffered) ||
4331 			     (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) >
4332 			      rack->r_ctl.rc_target_probertt_flight)) {
4333 				/* We are not past the must_stay time */
4334 				goto no_exit;
4335 			}
4336 			rack_log_rtt_shrinks(rack,  us_cts,
4337 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4338 					     __LINE__, RACK_RTTS_REACHTARGET);
4339 			rack->r_ctl.rc_time_probertt_starts = us_cts;
4340 			if (rack->r_ctl.rc_time_probertt_starts == 0)
4341 				rack->r_ctl.rc_time_probertt_starts = 1;
4342 			/* Restore back to our rate we want to pace at in prtt */
4343 			rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
4344 		}
4345 		/*
4346 		 * Setup our end time, some number of gp_srtts plus 200ms.
4347 		 */
4348 		no_overflow = ((uint64_t)rack->r_ctl.rc_gp_srtt *
4349 			       (uint64_t)rack_probertt_gpsrtt_cnt_mul);
4350 		if (rack_probertt_gpsrtt_cnt_div)
4351 			endtime = (uint32_t)(no_overflow / (uint64_t)rack_probertt_gpsrtt_cnt_div);
4352 		else
4353 			endtime = 0;
4354 		endtime += rack_min_probertt_hold;
4355 		endtime += rack->r_ctl.rc_time_probertt_starts;
4356 		if (TSTMP_GEQ(us_cts,  endtime)) {
4357 			/* yes, exit probertt */
4358 			rack_exit_probertt(rack, us_cts);
4359 		}
4360 
4361 	} else if ((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= rack_time_between_probertt) {
4362 		/* Go into probertt, its been too long since we went lower */
4363 		rack_enter_probertt(rack, us_cts);
4364 	}
4365 }
4366 
4367 static void
4368 rack_update_multiplier(struct tcp_rack *rack, int32_t timely_says, uint64_t last_bw_est,
4369 		       uint32_t rtt, int32_t rtt_diff)
4370 {
4371 	uint64_t cur_bw, up_bnd, low_bnd, subfr;
4372 	uint32_t losses;
4373 
4374 	if ((rack->rc_gp_dyn_mul == 0) ||
4375 	    (rack->use_fixed_rate) ||
4376 	    (rack->in_probe_rtt) ||
4377 	    (rack->rc_always_pace == 0)) {
4378 		/* No dynamic GP multiplier in play */
4379 		return;
4380 	}
4381 	losses = rack->r_ctl.rc_loss_count - rack->r_ctl.rc_loss_at_start;
4382 	cur_bw = rack_get_bw(rack);
4383 	/* Calculate our up and down range */
4384 	up_bnd = rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_up;
4385 	up_bnd /= 100;
4386 	up_bnd += rack->r_ctl.last_gp_comp_bw;
4387 
4388 	subfr = (uint64_t)rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_down;
4389 	subfr /= 100;
4390 	low_bnd = rack->r_ctl.last_gp_comp_bw - subfr;
4391 	if ((timely_says == 2) && (rack->r_ctl.rc_no_push_at_mrtt)) {
4392 		/*
4393 		 * This is the case where our RTT is above
4394 		 * the max target and we have been configured
4395 		 * to just do timely no bonus up stuff in that case.
4396 		 *
4397 		 * There are two configurations, set to 1, and we
4398 		 * just do timely if we are over our max. If its
4399 		 * set above 1 then we slam the multipliers down
4400 		 * to 100 and then decrement per timely.
4401 		 */
4402 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4403 				__LINE__, 3);
4404 		if (rack->r_ctl.rc_no_push_at_mrtt > 1)
4405 			rack_validate_multipliers_at_or_below_100(rack);
4406 		rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
4407 	} else if ((timely_says != 0) && (last_bw_est < low_bnd) && !losses) {
4408 		/*
4409 		 * We are decreasing this is a bit complicated this
4410 		 * means we are loosing ground. This could be
4411 		 * because another flow entered and we are competing
4412 		 * for b/w with it. This will push the RTT up which
4413 		 * makes timely unusable unless we want to get shoved
4414 		 * into a corner and just be backed off (the age
4415 		 * old problem with delay based CC).
4416 		 *
4417 		 * On the other hand if it was a route change we
4418 		 * would like to stay somewhat contained and not
4419 		 * blow out the buffers.
4420 		 */
4421 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4422 				__LINE__, 3);
4423 		rack->r_ctl.last_gp_comp_bw = cur_bw;
4424 		if (rack->rc_gp_bwred == 0) {
4425 			/* Go into reduction counting */
4426 			rack->rc_gp_bwred = 1;
4427 			rack->rc_gp_timely_dec_cnt = 0;
4428 		}
4429 		if (rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) {
4430 			/*
4431 			 * Push another time with a faster pacing
4432 			 * to try to gain back (we include override to
4433 			 * get a full raise factor).
4434 			 */
4435 			if ((rack->rc_gp_saw_ca && rack->r_ctl.rack_per_of_gp_ca <= rack_down_raise_thresh) ||
4436 			    (rack->rc_gp_saw_ss && rack->r_ctl.rack_per_of_gp_ss <= rack_down_raise_thresh) ||
4437 			    (timely_says == 0) ||
4438 			    (rack_down_raise_thresh == 0)) {
4439 				/*
4440 				 * Do an override up in b/w if we were
4441 				 * below the threshold or if the threshold
4442 				 * is zero we always do the raise.
4443 				 */
4444 				rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 1);
4445 			} else {
4446 				/* Log it stays the same */
4447 				rack_log_timely(rack,  0, last_bw_est, low_bnd, 0,
4448 						__LINE__, 11);
4449 			}
4450 			rack->rc_gp_timely_dec_cnt++;
4451 			/* We are not incrementing really no-count */
4452 			rack->rc_gp_incr = 0;
4453 			rack->rc_gp_timely_inc_cnt = 0;
4454 		} else {
4455 			/*
4456 			 * Lets just use the RTT
4457 			 * information and give up
4458 			 * pushing.
4459 			 */
4460 			goto use_timely;
4461 		}
4462 	} else if ((timely_says != 2) &&
4463 		    !losses &&
4464 		    (last_bw_est > up_bnd)) {
4465 		/*
4466 		 * We are increasing b/w lets keep going, updating
4467 		 * our b/w and ignoring any timely input, unless
4468 		 * of course we are at our max raise (if there is one).
4469 		 */
4470 
4471 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4472 				__LINE__, 3);
4473 		rack->r_ctl.last_gp_comp_bw = cur_bw;
4474 		if (rack->rc_gp_saw_ss &&
4475 		    rack->r_ctl.rack_per_upper_bound_ss &&
4476 		     (rack->r_ctl.rack_per_of_gp_ss == rack->r_ctl.rack_per_upper_bound_ss)) {
4477 			    /*
4478 			     * In cases where we can't go higher
4479 			     * we should just use timely.
4480 			     */
4481 			    goto use_timely;
4482 		}
4483 		if (rack->rc_gp_saw_ca &&
4484 		    rack->r_ctl.rack_per_upper_bound_ca &&
4485 		    (rack->r_ctl.rack_per_of_gp_ca == rack->r_ctl.rack_per_upper_bound_ca)) {
4486 			    /*
4487 			     * In cases where we can't go higher
4488 			     * we should just use timely.
4489 			     */
4490 			    goto use_timely;
4491 		}
4492 		rack->rc_gp_bwred = 0;
4493 		rack->rc_gp_timely_dec_cnt = 0;
4494 		/* You get a set number of pushes if timely is trying to reduce */
4495 		if ((rack->rc_gp_incr < rack_timely_max_push_rise) || (timely_says == 0)) {
4496 			rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4497 		} else {
4498 			/* Log it stays the same */
4499 			rack_log_timely(rack,  0, last_bw_est, up_bnd, 0,
4500 			    __LINE__, 12);
4501 		}
4502 		return;
4503 	} else {
4504 		/*
4505 		 * We are staying between the lower and upper range bounds
4506 		 * so use timely to decide.
4507 		 */
4508 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4509 				__LINE__, 3);
4510 use_timely:
4511 		if (timely_says) {
4512 			rack->rc_gp_incr = 0;
4513 			rack->rc_gp_timely_inc_cnt = 0;
4514 			if ((rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) &&
4515 			    !losses &&
4516 			    (last_bw_est < low_bnd)) {
4517 				/* We are loosing ground */
4518 				rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4519 				rack->rc_gp_timely_dec_cnt++;
4520 				/* We are not incrementing really no-count */
4521 				rack->rc_gp_incr = 0;
4522 				rack->rc_gp_timely_inc_cnt = 0;
4523 			} else
4524 				rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
4525 		} else {
4526 			rack->rc_gp_bwred = 0;
4527 			rack->rc_gp_timely_dec_cnt = 0;
4528 			rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4529 		}
4530 	}
4531 }
4532 
4533 static int32_t
4534 rack_make_timely_judgement(struct tcp_rack *rack, uint32_t rtt, int32_t rtt_diff, uint32_t prev_rtt)
4535 {
4536 	int32_t timely_says;
4537 	uint64_t log_mult, log_rtt_a_diff;
4538 
4539 	log_rtt_a_diff = rtt;
4540 	log_rtt_a_diff <<= 32;
4541 	log_rtt_a_diff |= (uint32_t)rtt_diff;
4542 	if (rtt >= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) *
4543 		    rack_gp_rtt_maxmul)) {
4544 		/* Reduce the b/w multiplier */
4545 		timely_says = 2;
4546 		log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
4547 		log_mult <<= 32;
4548 		log_mult |= prev_rtt;
4549 		rack_log_timely(rack,  timely_says, log_mult,
4550 				get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4551 				log_rtt_a_diff, __LINE__, 4);
4552 	} else if (rtt <= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
4553 			   ((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
4554 			    max(rack_gp_rtt_mindiv , 1)))) {
4555 		/* Increase the b/w multiplier */
4556 		log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
4557 			((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
4558 			 max(rack_gp_rtt_mindiv , 1));
4559 		log_mult <<= 32;
4560 		log_mult |= prev_rtt;
4561 		timely_says = 0;
4562 		rack_log_timely(rack,  timely_says, log_mult ,
4563 				get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4564 				log_rtt_a_diff, __LINE__, 5);
4565 	} else {
4566 		/*
4567 		 * Use a gradient to find it the timely gradient
4568 		 * is:
4569 		 * grad = rc_rtt_diff / min_rtt;
4570 		 *
4571 		 * anything below or equal to 0 will be
4572 		 * a increase indication. Anything above
4573 		 * zero is a decrease. Note we take care
4574 		 * of the actual gradient calculation
4575 		 * in the reduction (its not needed for
4576 		 * increase).
4577 		 */
4578 		log_mult = prev_rtt;
4579 		if (rtt_diff <= 0) {
4580 			/*
4581 			 * Rttdiff is less than zero, increase the
4582 			 * b/w multiplier (its 0 or negative)
4583 			 */
4584 			timely_says = 0;
4585 			rack_log_timely(rack,  timely_says, log_mult,
4586 					get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 6);
4587 		} else {
4588 			/* Reduce the b/w multiplier */
4589 			timely_says = 1;
4590 			rack_log_timely(rack,  timely_says, log_mult,
4591 					get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 7);
4592 		}
4593 	}
4594 	return (timely_says);
4595 }
4596 
4597 static __inline int
4598 rack_in_gp_window(struct tcpcb *tp, struct rack_sendmap *rsm)
4599 {
4600 	if (SEQ_GEQ(rsm->r_start, tp->gput_seq) &&
4601 	    SEQ_LEQ(rsm->r_end, tp->gput_ack)) {
4602 		/**
4603 		 * This covers the case that the
4604 		 * resent is completely inside
4605 		 * the gp range or up to it.
4606 		 *      |----------------|
4607 		 *      |-----| <or>
4608 		 *            |----|
4609 		 *            <or>   |---|
4610 		 */
4611 		return (1);
4612 	} else if (SEQ_LT(rsm->r_start, tp->gput_seq) &&
4613 		   SEQ_GT(rsm->r_end, tp->gput_seq)){
4614 		/**
4615 		 * This covers the case of
4616 		 *      |--------------|
4617 		 *  |-------->|
4618 		 */
4619 		return (1);
4620 	} else if (SEQ_GEQ(rsm->r_start, tp->gput_seq) &&
4621 		   SEQ_LT(rsm->r_start, tp->gput_ack) &&
4622 		   SEQ_GEQ(rsm->r_end, tp->gput_ack)) {
4623 
4624 		/**
4625 		 * This covers the case of
4626 		 *      |--------------|
4627 		 *              |-------->|
4628 		 */
4629 		return (1);
4630 	}
4631 	return (0);
4632 }
4633 
4634 static __inline void
4635 rack_mark_in_gp_win(struct tcpcb *tp, struct rack_sendmap *rsm)
4636 {
4637 
4638 	if ((tp->t_flags & TF_GPUTINPROG) == 0)
4639 		return;
4640 	/*
4641 	 * We have a Goodput measurement in progress. Mark
4642 	 * the send if its within the window. If its not
4643 	 * in the window make sure it does not have the mark.
4644 	 */
4645 	if (rack_in_gp_window(tp, rsm))
4646 		rsm->r_flags |= RACK_IN_GP_WIN;
4647 	else
4648 		rsm->r_flags &= ~RACK_IN_GP_WIN;
4649 }
4650 
4651 static __inline void
4652 rack_clear_gp_marks(struct tcpcb *tp, struct tcp_rack *rack)
4653 {
4654 	/* A GP measurement is ending, clear all marks on the send map*/
4655 	struct rack_sendmap *rsm = NULL;
4656 
4657 	rsm = tqhash_find(rack->r_ctl.tqh, tp->gput_seq);
4658 	if (rsm == NULL) {
4659 		rsm = tqhash_min(rack->r_ctl.tqh);
4660 	}
4661 	/* Nothing left? */
4662 	while ((rsm != NULL) && (SEQ_GEQ(tp->gput_ack, rsm->r_start))){
4663 		rsm->r_flags &= ~RACK_IN_GP_WIN;
4664 		rsm = tqhash_next(rack->r_ctl.tqh, rsm);
4665 	}
4666 }
4667 
4668 
4669 static __inline void
4670 rack_tend_gp_marks(struct tcpcb *tp, struct tcp_rack *rack)
4671 {
4672 	struct rack_sendmap *rsm = NULL;
4673 
4674 	if (tp->snd_una == tp->snd_max) {
4675 		/* Nothing outstanding yet, nothing to do here */
4676 		return;
4677 	}
4678 	if (SEQ_GT(tp->gput_seq, tp->snd_una)) {
4679 		/*
4680 		 * We are measuring ahead of some outstanding
4681 		 * data. We need to walk through up until we get
4682 		 * to gp_seq marking so that no rsm is set incorrectly
4683 		 * with RACK_IN_GP_WIN.
4684 		 */
4685 		rsm = tqhash_min(rack->r_ctl.tqh);
4686 		while (rsm != NULL) {
4687 			rack_mark_in_gp_win(tp, rsm);
4688 			if (SEQ_GEQ(rsm->r_end, tp->gput_seq))
4689 				break;
4690 			rsm = tqhash_next(rack->r_ctl.tqh, rsm);
4691 		}
4692 	}
4693 	if (rsm == NULL) {
4694 		/*
4695 		 * Need to find the GP seq, if rsm is
4696 		 * set we stopped as we hit it.
4697 		 */
4698 		rsm = tqhash_find(rack->r_ctl.tqh, tp->gput_seq);
4699 		if (rsm == NULL)
4700 			return;
4701 		rack_mark_in_gp_win(tp, rsm);
4702 	}
4703 	/*
4704 	 * Now we may need to mark already sent rsm, ahead of
4705 	 * gput_seq in the window since they may have been sent
4706 	 * *before* we started our measurment. The rsm, if non-null
4707 	 * has been marked (note if rsm would have been NULL we would have
4708 	 * returned in the previous block). So we go to the next, and continue
4709 	 * until we run out of entries or we exceed the gp_ack value.
4710 	 */
4711 	rsm = tqhash_next(rack->r_ctl.tqh, rsm);
4712 	while (rsm) {
4713 		rack_mark_in_gp_win(tp, rsm);
4714 		if (SEQ_GT(rsm->r_end, tp->gput_ack))
4715 			break;
4716 		rsm = tqhash_next(rack->r_ctl.tqh, rsm);
4717 	}
4718 }
4719 
4720 static void
4721 rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
4722 			    tcp_seq th_ack, int line, uint8_t quality)
4723 {
4724 	uint64_t tim, bytes_ps, stim, utim;
4725 	uint32_t segsiz, bytes, reqbytes, us_cts;
4726 	int32_t gput, new_rtt_diff, timely_says;
4727 	uint64_t  resid_bw, subpart = 0, addpart = 0, srtt;
4728 	int did_add = 0;
4729 
4730 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
4731 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
4732 	if (TSTMP_GEQ(us_cts, tp->gput_ts))
4733 		tim = us_cts - tp->gput_ts;
4734 	else
4735 		tim = 0;
4736 	if (rack->r_ctl.rc_gp_cumack_ts > rack->r_ctl.rc_gp_output_ts)
4737 		stim = rack->r_ctl.rc_gp_cumack_ts - rack->r_ctl.rc_gp_output_ts;
4738 	else
4739 		stim = 0;
4740 	/*
4741 	 * Use the larger of the send time or ack time. This prevents us
4742 	 * from being influenced by ack artifacts to come up with too
4743 	 * high of measurement. Note that since we are spanning over many more
4744 	 * bytes in most of our measurements hopefully that is less likely to
4745 	 * occur.
4746 	 */
4747 	if (tim > stim)
4748 		utim = max(tim, 1);
4749 	else
4750 		utim = max(stim, 1);
4751 	reqbytes = min(rc_init_window(rack), (MIN_GP_WIN * segsiz));
4752 	rack_log_gpset(rack, th_ack, us_cts, rack->r_ctl.rc_gp_cumack_ts, __LINE__, 3, NULL);
4753 	if ((tim == 0) && (stim == 0)) {
4754 		/*
4755 		 * Invalid measurement time, maybe
4756 		 * all on one ack/one send?
4757 		 */
4758 		bytes = 0;
4759 		bytes_ps = 0;
4760 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4761 					   0, 0, 0, 10, __LINE__, NULL, quality);
4762 		goto skip_measurement;
4763 	}
4764 	if (rack->r_ctl.rc_gp_lowrtt == 0xffffffff) {
4765 		/* We never made a us_rtt measurement? */
4766 		bytes = 0;
4767 		bytes_ps = 0;
4768 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4769 					   0, 0, 0, 10, __LINE__, NULL, quality);
4770 		goto skip_measurement;
4771 	}
4772 	/*
4773 	 * Calculate the maximum possible b/w this connection
4774 	 * could have. We base our calculation on the lowest
4775 	 * rtt we have seen during the measurement and the
4776 	 * largest rwnd the client has given us in that time. This
4777 	 * forms a BDP that is the maximum that we could ever
4778 	 * get to the client. Anything larger is not valid.
4779 	 *
4780 	 * I originally had code here that rejected measurements
4781 	 * where the time was less than 1/2 the latest us_rtt.
4782 	 * But after thinking on that I realized its wrong since
4783 	 * say you had a 150Mbps or even 1Gbps link, and you
4784 	 * were a long way away.. example I am in Europe (100ms rtt)
4785 	 * talking to my 1Gbps link in S.C. Now measuring say 150,000
4786 	 * bytes my time would be 1.2ms, and yet my rtt would say
4787 	 * the measurement was invalid the time was < 50ms. The
4788 	 * same thing is true for 150Mb (8ms of time).
4789 	 *
4790 	 * A better way I realized is to look at what the maximum
4791 	 * the connection could possibly do. This is gated on
4792 	 * the lowest RTT we have seen and the highest rwnd.
4793 	 * We should in theory never exceed that, if we are
4794 	 * then something on the path is storing up packets
4795 	 * and then feeding them all at once to our endpoint
4796 	 * messing up our measurement.
4797 	 */
4798 	rack->r_ctl.last_max_bw = rack->r_ctl.rc_gp_high_rwnd;
4799 	rack->r_ctl.last_max_bw *= HPTS_USEC_IN_SEC;
4800 	rack->r_ctl.last_max_bw /= rack->r_ctl.rc_gp_lowrtt;
4801 	if (SEQ_LT(th_ack, tp->gput_seq)) {
4802 		/* No measurement can be made */
4803 		bytes = 0;
4804 		bytes_ps = 0;
4805 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4806 					   0, 0, 0, 10, __LINE__, NULL, quality);
4807 		goto skip_measurement;
4808 	} else
4809 		bytes = (th_ack - tp->gput_seq);
4810 	bytes_ps = (uint64_t)bytes;
4811 	/*
4812 	 * Don't measure a b/w for pacing unless we have gotten at least
4813 	 * an initial windows worth of data in this measurement interval.
4814 	 *
4815 	 * Small numbers of bytes get badly influenced by delayed ack and
4816 	 * other artifacts. Note we take the initial window or our
4817 	 * defined minimum GP (defaulting to 10 which hopefully is the
4818 	 * IW).
4819 	 */
4820 	if (rack->rc_gp_filled == 0) {
4821 		/*
4822 		 * The initial estimate is special. We
4823 		 * have blasted out an IW worth of packets
4824 		 * without a real valid ack ts results. We
4825 		 * then setup the app_limited_needs_set flag,
4826 		 * this should get the first ack in (probably 2
4827 		 * MSS worth) to be recorded as the timestamp.
4828 		 * We thus allow a smaller number of bytes i.e.
4829 		 * IW - 2MSS.
4830 		 */
4831 		reqbytes -= (2 * segsiz);
4832 		/* Also lets fill previous for our first measurement to be neutral */
4833 		rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
4834 	}
4835 	if ((bytes_ps < reqbytes) || rack->app_limited_needs_set) {
4836 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4837 					   rack->r_ctl.rc_app_limited_cnt,
4838 					   0, 0, 10, __LINE__, NULL, quality);
4839 		goto skip_measurement;
4840 	}
4841 	/*
4842 	 * We now need to calculate the Timely like status so
4843 	 * we can update (possibly) the b/w multipliers.
4844 	 */
4845 	new_rtt_diff = (int32_t)rack->r_ctl.rc_gp_srtt - (int32_t)rack->r_ctl.rc_prev_gp_srtt;
4846 	if (rack->rc_gp_filled == 0) {
4847 		/* No previous reading */
4848 		rack->r_ctl.rc_rtt_diff = new_rtt_diff;
4849 	} else {
4850 		if (rack->measure_saw_probe_rtt == 0) {
4851 			/*
4852 			 * We don't want a probertt to be counted
4853 			 * since it will be negative incorrectly. We
4854 			 * expect to be reducing the RTT when we
4855 			 * pace at a slower rate.
4856 			 */
4857 			rack->r_ctl.rc_rtt_diff -= (rack->r_ctl.rc_rtt_diff / 8);
4858 			rack->r_ctl.rc_rtt_diff += (new_rtt_diff / 8);
4859 		}
4860 	}
4861 	timely_says = rack_make_timely_judgement(rack,
4862 	    rack->r_ctl.rc_gp_srtt,
4863 	    rack->r_ctl.rc_rtt_diff,
4864 	    rack->r_ctl.rc_prev_gp_srtt
4865 	);
4866 	bytes_ps *= HPTS_USEC_IN_SEC;
4867 	bytes_ps /= utim;
4868 	if (bytes_ps > rack->r_ctl.last_max_bw) {
4869 		/*
4870 		 * Something is on path playing
4871 		 * since this b/w is not possible based
4872 		 * on our BDP (highest rwnd and lowest rtt
4873 		 * we saw in the measurement window).
4874 		 *
4875 		 * Another option here would be to
4876 		 * instead skip the measurement.
4877 		 */
4878 		rack_log_pacing_delay_calc(rack, bytes, reqbytes,
4879 					   bytes_ps, rack->r_ctl.last_max_bw, 0,
4880 					   11, __LINE__, NULL, quality);
4881 		bytes_ps = rack->r_ctl.last_max_bw;
4882 	}
4883 	/* We store gp for b/w in bytes per second */
4884 	if (rack->rc_gp_filled == 0) {
4885 		/* Initial measurement */
4886 		if (bytes_ps) {
4887 			rack->r_ctl.gp_bw = bytes_ps;
4888 			rack->rc_gp_filled = 1;
4889 			rack->r_ctl.num_measurements = 1;
4890 			rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
4891 		} else {
4892 			rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4893 						   rack->r_ctl.rc_app_limited_cnt,
4894 						   0, 0, 10, __LINE__, NULL, quality);
4895 		}
4896 		if (tcp_in_hpts(rack->rc_inp) &&
4897 		    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
4898 			/*
4899 			 * Ok we can't trust the pacer in this case
4900 			 * where we transition from un-paced to paced.
4901 			 * Or for that matter when the burst mitigation
4902 			 * was making a wild guess and got it wrong.
4903 			 * Stop the pacer and clear up all the aggregate
4904 			 * delays etc.
4905 			 */
4906 			tcp_hpts_remove(rack->rc_inp);
4907 			rack->r_ctl.rc_hpts_flags = 0;
4908 			rack->r_ctl.rc_last_output_to = 0;
4909 		}
4910 		did_add = 2;
4911 	} else if (rack->r_ctl.num_measurements < RACK_REQ_AVG) {
4912 		/* Still a small number run an average */
4913 		rack->r_ctl.gp_bw += bytes_ps;
4914 		addpart = rack->r_ctl.num_measurements;
4915 		rack->r_ctl.num_measurements++;
4916 		if (rack->r_ctl.num_measurements >= RACK_REQ_AVG) {
4917 			/* We have collected enough to move forward */
4918 			rack->r_ctl.gp_bw /= (uint64_t)rack->r_ctl.num_measurements;
4919 		}
4920 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
4921 		did_add = 3;
4922 	} else {
4923 		/*
4924 		 * We want to take 1/wma of the goodput and add in to 7/8th
4925 		 * of the old value weighted by the srtt. So if your measurement
4926 		 * period is say 2 SRTT's long you would get 1/4 as the
4927 		 * value, if it was like 1/2 SRTT then you would get 1/16th.
4928 		 *
4929 		 * But we must be careful not to take too much i.e. if the
4930 		 * srtt is say 20ms and the measurement is taken over
4931 		 * 400ms our weight would be 400/20 i.e. 20. On the
4932 		 * other hand if we get a measurement over 1ms with a
4933 		 * 10ms rtt we only want to take a much smaller portion.
4934 		 */
4935 		if (rack->r_ctl.num_measurements < 0xff) {
4936 			rack->r_ctl.num_measurements++;
4937 		}
4938 		srtt = (uint64_t)tp->t_srtt;
4939 		if (srtt == 0) {
4940 			/*
4941 			 * Strange why did t_srtt go back to zero?
4942 			 */
4943 			if (rack->r_ctl.rc_rack_min_rtt)
4944 				srtt = rack->r_ctl.rc_rack_min_rtt;
4945 			else
4946 				srtt = HPTS_USEC_IN_MSEC;
4947 		}
4948 		/*
4949 		 * XXXrrs: Note for reviewers, in playing with
4950 		 * dynamic pacing I discovered this GP calculation
4951 		 * as done originally leads to some undesired results.
4952 		 * Basically you can get longer measurements contributing
4953 		 * too much to the WMA. Thus I changed it if you are doing
4954 		 * dynamic adjustments to only do the aportioned adjustment
4955 		 * if we have a very small (time wise) measurement. Longer
4956 		 * measurements just get there weight (defaulting to 1/8)
4957 		 * add to the WMA. We may want to think about changing
4958 		 * this to always do that for both sides i.e. dynamic
4959 		 * and non-dynamic... but considering lots of folks
4960 		 * were playing with this I did not want to change the
4961 		 * calculation per.se. without your thoughts.. Lawerence?
4962 		 * Peter??
4963 		 */
4964 		if (rack->rc_gp_dyn_mul == 0) {
4965 			subpart = rack->r_ctl.gp_bw * utim;
4966 			subpart /= (srtt * 8);
4967 			if (subpart < (rack->r_ctl.gp_bw / 2)) {
4968 				/*
4969 				 * The b/w update takes no more
4970 				 * away then 1/2 our running total
4971 				 * so factor it in.
4972 				 */
4973 				addpart = bytes_ps * utim;
4974 				addpart /= (srtt * 8);
4975 			} else {
4976 				/*
4977 				 * Don't allow a single measurement
4978 				 * to account for more than 1/2 of the
4979 				 * WMA. This could happen on a retransmission
4980 				 * where utim becomes huge compared to
4981 				 * srtt (multiple retransmissions when using
4982 				 * the sending rate which factors in all the
4983 				 * transmissions from the first one).
4984 				 */
4985 				subpart = rack->r_ctl.gp_bw / 2;
4986 				addpart = bytes_ps / 2;
4987 			}
4988 			resid_bw = rack->r_ctl.gp_bw - subpart;
4989 			rack->r_ctl.gp_bw = resid_bw + addpart;
4990 			did_add = 1;
4991 		} else {
4992 			if ((utim / srtt) <= 1) {
4993 				/*
4994 				 * The b/w update was over a small period
4995 				 * of time. The idea here is to prevent a small
4996 				 * measurement time period from counting
4997 				 * too much. So we scale it based on the
4998 				 * time so it attributes less than 1/rack_wma_divisor
4999 				 * of its measurement.
5000 				 */
5001 				subpart = rack->r_ctl.gp_bw * utim;
5002 				subpart /= (srtt * rack_wma_divisor);
5003 				addpart = bytes_ps * utim;
5004 				addpart /= (srtt * rack_wma_divisor);
5005 			} else {
5006 				/*
5007 				 * The scaled measurement was long
5008 				 * enough so lets just add in the
5009 				 * portion of the measurement i.e. 1/rack_wma_divisor
5010 				 */
5011 				subpart = rack->r_ctl.gp_bw / rack_wma_divisor;
5012 				addpart = bytes_ps / rack_wma_divisor;
5013 			}
5014 			if ((rack->measure_saw_probe_rtt == 0) ||
5015 		            (bytes_ps > rack->r_ctl.gp_bw)) {
5016 				/*
5017 				 * For probe-rtt we only add it in
5018 				 * if its larger, all others we just
5019 				 * add in.
5020 				 */
5021 				did_add = 1;
5022 				resid_bw = rack->r_ctl.gp_bw - subpart;
5023 				rack->r_ctl.gp_bw = resid_bw + addpart;
5024 			}
5025 		}
5026 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
5027 	}
5028 	if ((rack->gp_ready == 0) &&
5029 	    (rack->r_ctl.num_measurements >= rack->r_ctl.req_measurements)) {
5030 		/* We have enough measurements now */
5031 		rack->gp_ready = 1;
5032 		if ((rack->rc_always_pace && (rack->use_fixed_rate == 0)) ||
5033 		    rack->rack_hibeta)
5034 			rack_set_cc_pacing(rack);
5035 		if (rack->defer_options)
5036 			rack_apply_deferred_options(rack);
5037 	}
5038 	rack_log_pacing_delay_calc(rack, subpart, addpart, bytes_ps, stim,
5039 				   rack_get_bw(rack), 22, did_add, NULL, quality);
5040 	/* We do not update any multipliers if we are in or have seen a probe-rtt */
5041 	if ((rack->measure_saw_probe_rtt == 0) && rack->rc_gp_rtt_set)
5042 		rack_update_multiplier(rack, timely_says, bytes_ps,
5043 				       rack->r_ctl.rc_gp_srtt,
5044 				       rack->r_ctl.rc_rtt_diff);
5045 	rack_log_pacing_delay_calc(rack, bytes, tim, bytes_ps, stim,
5046 				   rack_get_bw(rack), 3, line, NULL, quality);
5047 	rack_log_pacing_delay_calc(rack,
5048 				   bytes, /* flex2 */
5049 				   tim, /* flex1 */
5050 				   bytes_ps, /* bw_inuse */
5051 				   rack->r_ctl.gp_bw, /* delRate */
5052 				   rack_get_lt_bw(rack), /* rttProp */
5053 				   20, line, NULL, 0);
5054 	/* reset the gp srtt and setup the new prev */
5055 	rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
5056 	/* Record the lost count for the next measurement */
5057 	rack->r_ctl.rc_loss_at_start = rack->r_ctl.rc_loss_count;
5058 skip_measurement:
5059 	/*
5060 	 * We restart our diffs based on the gpsrtt in the
5061 	 * measurement window.
5062 	 */
5063 	rack->rc_gp_rtt_set = 0;
5064 	rack->rc_gp_saw_rec = 0;
5065 	rack->rc_gp_saw_ca = 0;
5066 	rack->rc_gp_saw_ss = 0;
5067 	rack->rc_dragged_bottom = 0;
5068 
5069 	if (quality == RACK_QUALITY_HIGH) {
5070 		/*
5071 		 * Gput in the stats world is in kbps where bytes_ps is
5072 		 * bytes per second so we do ((x * 8)/ 1000).
5073 		 */
5074 		gput = (int32_t)((bytes_ps << 3) / (uint64_t)1000);
5075 #ifdef STATS
5076 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_GPUT,
5077 					 gput);
5078 		/*
5079 		 * XXXLAS: This is a temporary hack, and should be
5080 		 * chained off VOI_TCP_GPUT when stats(9) grows an
5081 		 * API to deal with chained VOIs.
5082 		 */
5083 		if (tp->t_stats_gput_prev > 0)
5084 			stats_voi_update_abs_s32(tp->t_stats,
5085 						 VOI_TCP_GPUT_ND,
5086 						 ((gput - tp->t_stats_gput_prev) * 100) /
5087 						 tp->t_stats_gput_prev);
5088 #endif
5089 		tp->t_stats_gput_prev = gput;
5090 	}
5091 	tp->t_flags &= ~TF_GPUTINPROG;
5092 	/*
5093 	 * Now are we app limited now and there is space from where we
5094 	 * were to where we want to go?
5095 	 *
5096 	 * We don't do the other case i.e. non-applimited here since
5097 	 * the next send will trigger us picking up the missing data.
5098 	 */
5099 	if (rack->r_ctl.rc_first_appl &&
5100 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
5101 	    rack->r_ctl.rc_app_limited_cnt &&
5102 	    (SEQ_GT(rack->r_ctl.rc_first_appl->r_start, th_ack)) &&
5103 	    ((rack->r_ctl.rc_first_appl->r_end - th_ack) >
5104 	     max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
5105 		/*
5106 		 * Yep there is enough outstanding to make a measurement here.
5107 		 */
5108 		struct rack_sendmap *rsm;
5109 
5110 		rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
5111 		rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
5112 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
5113 		rack->app_limited_needs_set = 0;
5114 		tp->gput_seq = th_ack;
5115 		if (rack->in_probe_rtt)
5116 			rack->measure_saw_probe_rtt = 1;
5117 		else if ((rack->measure_saw_probe_rtt) &&
5118 			 (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
5119 			rack->measure_saw_probe_rtt = 0;
5120 		if ((rack->r_ctl.rc_first_appl->r_end - th_ack) >= rack_get_measure_window(tp, rack)) {
5121 			/* There is a full window to gain info from */
5122 			tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
5123 		} else {
5124 			/* We can only measure up to the applimited point */
5125 			tp->gput_ack = tp->gput_seq + (rack->r_ctl.rc_first_appl->r_end - th_ack);
5126 			if ((tp->gput_ack - tp->gput_seq) < (MIN_GP_WIN * segsiz)) {
5127 				/*
5128 				 * We don't have enough to make a measurement.
5129 				 */
5130 				tp->t_flags &= ~TF_GPUTINPROG;
5131 				rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
5132 							   0, 0, 0, 6, __LINE__, NULL, quality);
5133 				return;
5134 			}
5135 		}
5136 		if (tp->t_state >= TCPS_FIN_WAIT_1) {
5137 			/*
5138 			 * We will get no more data into the SB
5139 			 * this means we need to have the data available
5140 			 * before we start a measurement.
5141 			 */
5142 			if (sbavail(&tptosocket(tp)->so_snd) < (tp->gput_ack - tp->gput_seq)) {
5143 				/* Nope not enough data. */
5144 				return;
5145 			}
5146 		}
5147 		tp->t_flags |= TF_GPUTINPROG;
5148 		/*
5149 		 * Now we need to find the timestamp of the send at tp->gput_seq
5150 		 * for the send based measurement.
5151 		 */
5152 		rack->r_ctl.rc_gp_cumack_ts = 0;
5153 		rsm = tqhash_find(rack->r_ctl.tqh, tp->gput_seq);
5154 		if (rsm) {
5155 			/* Ok send-based limit is set */
5156 			if (SEQ_LT(rsm->r_start, tp->gput_seq)) {
5157 				/*
5158 				 * Move back to include the earlier part
5159 				 * so our ack time lines up right (this may
5160 				 * make an overlapping measurement but thats
5161 				 * ok).
5162 				 */
5163 				tp->gput_seq = rsm->r_start;
5164 			}
5165 			if (rsm->r_flags & RACK_ACKED) {
5166 				struct rack_sendmap *nrsm;
5167 
5168 				tp->gput_ts = (uint32_t)rsm->r_ack_arrival;
5169 				tp->gput_seq = rsm->r_end;
5170 				nrsm = tqhash_next(rack->r_ctl.tqh, rsm);
5171 				if (nrsm)
5172 					rsm = nrsm;
5173 				else {
5174 					rack->app_limited_needs_set = 1;
5175 				}
5176 			} else
5177 				rack->app_limited_needs_set = 1;
5178 			/* We always go from the first send */
5179 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[0];
5180 		} else {
5181 			/*
5182 			 * If we don't find the rsm due to some
5183 			 * send-limit set the current time, which
5184 			 * basically disables the send-limit.
5185 			 */
5186 			struct timeval tv;
5187 
5188 			microuptime(&tv);
5189 			rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
5190 		}
5191 		rack_tend_gp_marks(tp, rack);
5192 		rack_log_pacing_delay_calc(rack,
5193 					   tp->gput_seq,
5194 					   tp->gput_ack,
5195 					   (uint64_t)rsm,
5196 					   tp->gput_ts,
5197 					   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) | (uint64_t)rack->r_ctl.rc_gp_output_ts),
5198 					   9,
5199 					   __LINE__, rsm, quality);
5200 		rack_log_gpset(rack, tp->gput_ack, 0, 0, __LINE__, 1, NULL);
5201 	} else {
5202 		/*
5203 		 * To make sure proper timestamp merging occurs, we need to clear
5204 		 * all GP marks if we don't start a measurement.
5205 		 */
5206 		rack_clear_gp_marks(tp, rack);
5207 	}
5208 }
5209 
5210 /*
5211  * CC wrapper hook functions
5212  */
5213 static void
5214 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack, uint32_t th_ack, uint16_t nsegs,
5215     uint16_t type, int32_t recovery)
5216 {
5217 	uint32_t prior_cwnd, acked;
5218 	struct tcp_log_buffer *lgb = NULL;
5219 	uint8_t labc_to_use, quality;
5220 
5221 	INP_WLOCK_ASSERT(tptoinpcb(tp));
5222 	tp->t_ccv.nsegs = nsegs;
5223 	acked = tp->t_ccv.bytes_this_ack = (th_ack - tp->snd_una);
5224 	if ((recovery) && (rack->r_ctl.rc_early_recovery_segs)) {
5225 		uint32_t max;
5226 
5227 		max = rack->r_ctl.rc_early_recovery_segs * ctf_fixed_maxseg(tp);
5228 		if (tp->t_ccv.bytes_this_ack > max) {
5229 			tp->t_ccv.bytes_this_ack = max;
5230 		}
5231 	}
5232 #ifdef STATS
5233 	stats_voi_update_abs_s32(tp->t_stats, VOI_TCP_CALCFRWINDIFF,
5234 	    ((int32_t)rack->r_ctl.cwnd_to_use) - tp->snd_wnd);
5235 #endif
5236 	if ((th_ack == tp->snd_max) && rack->lt_bw_up) {
5237 		/* We will ack all, time
5238 		 * to end any lt_bw_up we
5239 		 * have running until something
5240 		 * new is sent.
5241 		 */
5242 		struct timeval tv;
5243 
5244 		rack->r_ctl.lt_bw_bytes += (tp->snd_max - rack->r_ctl.lt_seq);
5245 		rack->r_ctl.lt_seq = tp->snd_max;
5246 		(void)tcp_get_usecs(&tv);
5247 		rack->r_ctl.lt_bw_time += (tcp_tv_to_lusectick(&tv) - rack->r_ctl.lt_timemark);
5248 		rack->lt_bw_up = 0;
5249 	}
5250 	quality = RACK_QUALITY_NONE;
5251 	if ((tp->t_flags & TF_GPUTINPROG) &&
5252 	    rack_enough_for_measurement(tp, rack, th_ack, &quality)) {
5253 		/* Measure the Goodput */
5254 		rack_do_goodput_measurement(tp, rack, th_ack, __LINE__, quality);
5255 	}
5256 	/* Which way our we limited, if not cwnd limited no advance in CA */
5257 	if (tp->snd_cwnd <= tp->snd_wnd)
5258 		tp->t_ccv.flags |= CCF_CWND_LIMITED;
5259 	else
5260 		tp->t_ccv.flags &= ~CCF_CWND_LIMITED;
5261 	if (tp->snd_cwnd > tp->snd_ssthresh) {
5262 		tp->t_bytes_acked += min(tp->t_ccv.bytes_this_ack,
5263 			 nsegs * V_tcp_abc_l_var * ctf_fixed_maxseg(tp));
5264 		/* For the setting of a window past use the actual scwnd we are using */
5265 		if (tp->t_bytes_acked >= rack->r_ctl.cwnd_to_use) {
5266 			tp->t_bytes_acked -= rack->r_ctl.cwnd_to_use;
5267 			tp->t_ccv.flags |= CCF_ABC_SENTAWND;
5268 		}
5269 	} else {
5270 		tp->t_ccv.flags &= ~CCF_ABC_SENTAWND;
5271 		tp->t_bytes_acked = 0;
5272 	}
5273 	prior_cwnd = tp->snd_cwnd;
5274 	if ((recovery == 0) || (rack_max_abc_post_recovery == 0) || rack->r_use_labc_for_rec ||
5275 	    (rack_client_low_buf && rack->client_bufferlvl &&
5276 	    (rack->client_bufferlvl < rack_client_low_buf)))
5277 		labc_to_use = rack->rc_labc;
5278 	else
5279 		labc_to_use = rack_max_abc_post_recovery;
5280 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
5281 		union tcp_log_stackspecific log;
5282 		struct timeval tv;
5283 
5284 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5285 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5286 		log.u_bbr.flex1 = th_ack;
5287 		log.u_bbr.flex2 = tp->t_ccv.flags;
5288 		log.u_bbr.flex3 = tp->t_ccv.bytes_this_ack;
5289 		log.u_bbr.flex4 = tp->t_ccv.nsegs;
5290 		log.u_bbr.flex5 = labc_to_use;
5291 		log.u_bbr.flex6 = prior_cwnd;
5292 		log.u_bbr.flex7 = V_tcp_do_newsack;
5293 		log.u_bbr.flex8 = 1;
5294 		lgb = tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
5295 				     0, &log, false, NULL, __func__, __LINE__,&tv);
5296 	}
5297 	if (CC_ALGO(tp)->ack_received != NULL) {
5298 		/* XXXLAS: Find a way to live without this */
5299 		tp->t_ccv.curack = th_ack;
5300 		tp->t_ccv.labc = labc_to_use;
5301 		tp->t_ccv.flags |= CCF_USE_LOCAL_ABC;
5302 		CC_ALGO(tp)->ack_received(&tp->t_ccv, type);
5303 	}
5304 	if (lgb) {
5305 		lgb->tlb_stackinfo.u_bbr.flex6 = tp->snd_cwnd;
5306 	}
5307 	if (rack->r_must_retran) {
5308 		if (SEQ_GEQ(th_ack, rack->r_ctl.rc_snd_max_at_rto)) {
5309 			/*
5310 			 * We now are beyond the rxt point so lets disable
5311 			 * the flag.
5312 			 */
5313 			rack->r_ctl.rc_out_at_rto = 0;
5314 			rack->r_must_retran = 0;
5315 		} else if ((prior_cwnd + ctf_fixed_maxseg(tp)) <= tp->snd_cwnd) {
5316 			/*
5317 			 * Only decrement the rc_out_at_rto if the cwnd advances
5318 			 * at least a whole segment. Otherwise next time the peer
5319 			 * acks, we won't be able to send this generaly happens
5320 			 * when we are in Congestion Avoidance.
5321 			 */
5322 			if (acked <= rack->r_ctl.rc_out_at_rto){
5323 				rack->r_ctl.rc_out_at_rto -= acked;
5324 			} else {
5325 				rack->r_ctl.rc_out_at_rto = 0;
5326 			}
5327 		}
5328 	}
5329 #ifdef STATS
5330 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_LCWIN, rack->r_ctl.cwnd_to_use);
5331 #endif
5332 	if (rack->r_ctl.rc_rack_largest_cwnd < rack->r_ctl.cwnd_to_use) {
5333 		rack->r_ctl.rc_rack_largest_cwnd = rack->r_ctl.cwnd_to_use;
5334 	}
5335 }
5336 
5337 static void
5338 tcp_rack_partialack(struct tcpcb *tp)
5339 {
5340 	struct tcp_rack *rack;
5341 
5342 	rack = (struct tcp_rack *)tp->t_fb_ptr;
5343 	INP_WLOCK_ASSERT(tptoinpcb(tp));
5344 	/*
5345 	 * If we are doing PRR and have enough
5346 	 * room to send <or> we are pacing and prr
5347 	 * is disabled we will want to see if we
5348 	 * can send data (by setting r_wanted_output to
5349 	 * true).
5350 	 */
5351 	if ((rack->r_ctl.rc_prr_sndcnt > 0) ||
5352 	    rack->rack_no_prr)
5353 		rack->r_wanted_output = 1;
5354 }
5355 
5356 static inline void
5357 rack_set_most_aggr(struct tcp_rack *rack)
5358 {
5359 	rack->r_fill_less_agg = 0;
5360 	/* Once the cwnd as been clamped we don't do fill_cw */
5361 	if (rack->r_cwnd_was_clamped == 0)
5362 		rack->rc_pace_to_cwnd = 1;
5363 	rack->r_pacing_discount = 0;
5364 }
5365 
5366 static inline void
5367 rack_limit_fillcw(struct tcp_rack *rack)
5368 {
5369 	rack->r_fill_less_agg = 1;
5370 	/* Once the cwnd as been clamped we don't do fill_cw */
5371 	if (rack->r_cwnd_was_clamped == 0)
5372 		rack->rc_pace_to_cwnd = 1;
5373 	rack->r_pacing_discount = 0;
5374 }
5375 
5376 static inline void
5377 rack_disable_fillcw(struct tcp_rack *rack)
5378 {
5379 	rack->r_fill_less_agg = 1;
5380 	rack->rc_pace_to_cwnd = 0;
5381 	rack->r_pacing_discount = 0;
5382 }
5383 
5384 static void
5385 rack_client_buffer_level_set(struct tcp_rack *rack)
5386 {
5387 	/*
5388 	 * Only if DGP is on do we do anything that
5389 	 * changes stack behavior. If DGP is off all
5390 	 * we will do is issue a BB log (if BB logging is
5391 	 * on) and return.
5392 	 */
5393 	if (rack->dgp_on == 0) {
5394 		rack_log_pacing_delay_calc(rack, 0, rack->client_bufferlvl,
5395 					   0, 0, 0, 30, __LINE__, NULL, 0);
5396 		return;
5397 	}
5398 	if (IN_RECOVERY(rack->rc_tp->t_flags) && rack->r_ctl.full_dgp_in_rec) {
5399 		goto set_most_agg;
5400 	}
5401 	/*
5402 	 * We are in DGP so what setting should we
5403 	 * apply based on where the client is?
5404 	 */
5405 	switch(rack->r_ctl.rc_dgp_bl_agg) {
5406 	default:
5407 	case DGP_LEVEL0:
5408 set_most_agg:
5409 		rack_set_most_aggr(rack);
5410 		break;
5411 	case DGP_LEVEL1:
5412 		if (rack->client_bufferlvl == 4)
5413 			rack_limit_fillcw(rack);
5414 		else if (rack->client_bufferlvl == 5)
5415 			rack_disable_fillcw(rack);
5416 		else
5417 			rack_set_most_aggr(rack);
5418 		break;
5419 	case DGP_LEVEL2:
5420 		if (rack->client_bufferlvl == 3)
5421 			rack_limit_fillcw(rack);
5422 		else if (rack->client_bufferlvl == 4)
5423 			rack_disable_fillcw(rack);
5424 		else if (rack->client_bufferlvl == 5) {
5425 			rack_disable_fillcw(rack);
5426 			rack->r_pacing_discount = 1;
5427 			rack->r_ctl.pacing_discount_amm = 1;
5428 		} else
5429 			rack_set_most_aggr(rack);
5430 		break;
5431 	case DGP_LEVEL3:
5432 		if (rack->client_bufferlvl == 2)
5433 			rack_limit_fillcw(rack);
5434 		else if (rack->client_bufferlvl == 3)
5435 			rack_disable_fillcw(rack);
5436 		else if (rack->client_bufferlvl == 4) {
5437 			rack_disable_fillcw(rack);
5438 			rack->r_pacing_discount = 1;
5439 			rack->r_ctl.pacing_discount_amm = 1;
5440 		} else if (rack->client_bufferlvl == 5) {
5441 			rack_disable_fillcw(rack);
5442 			rack->r_pacing_discount = 1;
5443 			rack->r_ctl.pacing_discount_amm = 2;
5444 		} else
5445 			rack_set_most_aggr(rack);
5446 		break;
5447 	}
5448 	rack_log_pacing_delay_calc(rack, rack->r_ctl.rc_dgp_bl_agg, rack->client_bufferlvl, 0,
5449 				   0, 0, 30, __LINE__, NULL, 0);
5450 }
5451 
5452 static void
5453 do_rack_check_for_unclamp(struct tcpcb *tp, struct tcp_rack *rack)
5454 {
5455 	/*
5456 	 * Can we unclamp. We unclamp if more than
5457 	 * N rounds have transpired with no loss.
5458 	 */
5459 	uint64_t snds, rxts, rxt_per;
5460 	uint32_t rnds;
5461 
5462 	rnds = rack->r_ctl.current_round - rack->r_ctl.last_rnd_rxt_clamped;
5463 	if ((rack_unclamp_round_thresh > 0) &&
5464 	    (rnds >= rack_unclamp_round_thresh)) {
5465 		snds = tp->t_sndbytes - rack->r_ctl.last_sndbytes;
5466 		KASSERT ((snds > 0), ("rack:%p tp:%p snds:%ju is 0", rack, tp,
5467 		    (uintmax_t)snds));
5468 		rxts = tp->t_snd_rxt_bytes - rack->r_ctl.last_snd_rxt_bytes;
5469 		rxt_per = rxts * 1000;
5470 		rxt_per /= snds;
5471 		if ((uint32_t)rxt_per <= rack_unclamp_rxt_thresh) {
5472 			/* Unclamp */
5473 			if (tcp_bblogging_on(rack->rc_tp)) {
5474 				union tcp_log_stackspecific log;
5475 				struct timeval tv;
5476 
5477 				memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5478 				log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5479 				log.u_bbr.flex3 = rnds;
5480 				log.u_bbr.flex4 = rack_unclamp_round_thresh;
5481 				log.u_bbr.flex5 = (uint32_t)rxt_per;
5482 				log.u_bbr.flex8 = 6;
5483 				log.u_bbr.pkt_epoch = rack->r_ctl.rc_pace_max_segs;
5484 				log.u_bbr.bbr_state = rack->rc_pace_to_cwnd;
5485 				log.u_bbr.delivered = rack->r_ctl.num_of_clamps_applied;
5486 				log.u_bbr.applimited = rack->r_ctl.max_clamps;
5487 				log.u_bbr.epoch = rack->r_ctl.clamp_options;
5488 				log.u_bbr.cur_del_rate = rxts;
5489 				log.u_bbr.bw_inuse = rack_get_lt_bw(rack);
5490 				log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
5491 				log.u_bbr.lt_epoch = (uint32_t)((rack->r_ctl.gp_bw >> 32) & 0x00000000ffffffff);
5492 				log.u_bbr.pkts_out = (uint32_t)(rack->r_ctl.gp_bw & 0x00000000ffffffff);
5493 				tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
5494 					      0, &log, false, NULL, NULL, 0, &tv);
5495 			}
5496 			rack->r_ctl.num_of_clamps_applied = 0;
5497 			rack->r_cwnd_was_clamped = 0;
5498 			rack->excess_rxt_on = 1;
5499 			if (rack->r_ctl.clamp_options) {
5500 				/*
5501 				 * We only allow fillcw to be toggled
5502 				 * if you are setting a max seg too.
5503 				 */
5504 				if (rack->r_ctl.clamp_options & 0x1) {
5505 					if ((rack->rc_pace_to_cwnd == 0) && (rack->dgp_on == 0)) {
5506 						/* turn on fill cw  for non-dgp*/
5507 						rack->rc_pace_to_cwnd = 0;
5508 					} else if ((rack->dgp_on == 1) && (rack->rc_pace_to_cwnd == 1)) {
5509 						/* For DGP we want it off */
5510 						rack->rc_pace_to_cwnd = 1;
5511 					}
5512 				}
5513 			}
5514 			if (rack->dgp_on) {
5515 				/* Reset all multipliers to 100.0 so just the measured bw */
5516 				/* Crash any per boosts down to 100% */
5517 				rack->r_ctl.rack_per_of_gp_rec = 100;
5518 				rack->r_ctl.rack_per_of_gp_ss = 100;
5519 				rack->r_ctl.rack_per_of_gp_ca = 100;
5520 				/* Set in an upper bound for ss/ca % increase */
5521 				rack->r_ctl.rack_per_upper_bound_ss = (uint8_t)rack_per_upper_bound_ss;
5522 				rack->r_ctl.rack_per_upper_bound_ca = (uint8_t)rack_per_upper_bound_ca;
5523 			}
5524 		}
5525 	}
5526 }
5527 
5528 static void
5529 do_rack_excess_rxt(struct tcpcb *tp, struct tcp_rack *rack)
5530 {
5531 	/*
5532 	 * Rack excess rxt accounting is turned on. If we
5533 	 * are above a threshold of rxt's in at least N
5534 	 * rounds, then back off the cwnd and ssthresh
5535 	 * to fit into the long-term b/w.
5536 	 */
5537 	uint64_t snds, rxts, rxt_per, lt_bw, bdp;
5538 	uint32_t rnds, new_cwnd, new_ssthresh, rtt, shared_cwnd_was_enabled = 0;
5539 
5540 	/* Is it shut off by 0 rounds? */
5541 	if (rack_rxt_min_rnds == 0)
5542 		return;
5543 	if ((rack->r_ctl.max_clamps > 0) &&
5544 	    (rack->r_ctl.num_of_clamps_applied >= rack->r_ctl.max_clamps)) {
5545 		/*
5546 		 * The idea, if max_clamps is set, is that if clamping it
5547 		 * N times did not work again, then there is no sense
5548 		 * clamping it again. The link is just a lossy link and
5549 		 * our clamps are doing no good. Turn it off so we don't come
5550 		 * back here again.
5551 		 */
5552 		rack->excess_rxt_on = 0;
5553 		rack->r_cwnd_was_clamped = 0;
5554 		rack->r_ctl.num_of_clamps_applied = 0;
5555 		return;
5556 	}
5557 	snds = tp->t_sndbytes - rack->r_ctl.last_sndbytes;
5558 	rxts = tp->t_snd_rxt_bytes - rack->r_ctl.last_snd_rxt_bytes;
5559 	rnds = rack->r_ctl.current_round - rack->r_ctl.last_rnd_rxt_clamped;
5560 	/* Has enough rounds progressed for us to re-measure? */
5561 	if ((rnds >= rack_rxt_min_rnds) &&
5562 	    (rack->r_ctl.rxt_threshold > 0)){
5563 		rxt_per = rxts * 1000;
5564 		rxt_per /= snds;
5565 		if (rxt_per >= rack->r_ctl.rxt_threshold) {
5566 			/*
5567 			 * Action required:
5568 			 *  We are above our excess retransmit level, lets
5569 			 *  cut down the cwnd and ssthresh to match the long-term
5570 			 *  b/w we are getting.
5571 			 */
5572 			/* First disable scwnd if enabled */
5573 #ifdef NETFLIX_SHARED_CWND
5574 			rack->rack_enable_scwnd = 0;
5575 			if (rack->r_ctl.rc_scw) {
5576 				uint32_t limit;
5577 
5578 				shared_cwnd_was_enabled = 1;
5579 				if (rack->r_limit_scw)
5580 					limit = max(1, rack->r_ctl.rc_lowest_us_rtt);
5581 				else
5582 					limit = 0;
5583 				tcp_shared_cwnd_free_full(tp, rack->r_ctl.rc_scw,
5584 							  rack->r_ctl.rc_scw_index,
5585 							  limit);
5586 				rack->r_ctl.rc_scw = NULL;
5587 			}
5588 
5589 #endif
5590 			/* Calculate what the cwnd and ssthresh should be */
5591 			tcp_trace_point(rack->rc_tp, TCP_TP_EXCESS_RXT);
5592 			lt_bw = rack_get_lt_bw(rack);
5593 			if (lt_bw == 0) {
5594 				/*
5595 				 * No lt_bw, lets chop things to one MSS
5596 				 * and the ssthresh to the iwnd.
5597 				 */
5598 reset_to_iw:
5599 				new_cwnd = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
5600 				new_ssthresh = tcp_compute_initwnd(tcp_maxseg(tp));
5601 			} else {
5602 				rtt = rack->rc_rack_rtt;
5603 				if (rtt == 0) {
5604 					/* If we have no rack_rtt drop to the IW situation */
5605 					goto reset_to_iw;
5606 				}
5607 				bdp = lt_bw * (uint64_t)rtt;
5608 				bdp /= HPTS_USEC_IN_SEC;
5609 				new_cwnd = (uint32_t)bdp;
5610 				new_ssthresh = new_cwnd - 1;
5611 				if (new_cwnd < ctf_fixed_maxseg(tp)) {
5612 					/* Rock bottom, goto IW settings  */
5613 					goto reset_to_iw;
5614 				}
5615 			}
5616 			rack->r_cwnd_was_clamped = 1;
5617 			rack->r_ctl.num_of_clamps_applied++;
5618 			/* Reset the counter fromn now */
5619 			tp->t_bytes_acked = 0;
5620 			/*
5621 			 * Now what about options?
5622 			 * We look at the bottom  8 bits:
5623 			 * F = fill cw bit (toggle it if set)
5624 			 * S = Segment bits
5625 			 * M = set max segment bit
5626 			 *
5627 			 * SSSS SSMF
5628 			 */
5629 			if (rack->r_ctl.clamp_options) {
5630 				if (rack->r_ctl.clamp_options & 0x1) {
5631 					if ((rack->rc_pace_to_cwnd == 0) && (rack->dgp_on == 0)) {
5632 						/* turn on fill cw  for non-dgp*/
5633 						rack->rc_pace_to_cwnd = 1;
5634 					} else if ((rack->dgp_on == 1) && (rack->rc_pace_to_cwnd == 1)) {
5635 						/* For DGP we want it off */
5636 						rack->rc_pace_to_cwnd = 0;
5637 					}
5638 				}
5639 			}
5640 			if (rack->dgp_on) {
5641 				/* Reset all multipliers to 100.0 so just the measured bw */
5642 				/* Crash any per boosts down to 100% */
5643 				rack->r_ctl.rack_per_of_gp_rec = 100;
5644 				rack->r_ctl.rack_per_of_gp_ss = 100;
5645 				rack->r_ctl.rack_per_of_gp_ca = 100;
5646 				/* Set in an upper bound for ss/ca % increase */
5647 				rack->r_ctl.rack_per_upper_bound_ss = (uint8_t)rack_clamp_ss_upper;
5648 				rack->r_ctl.rack_per_upper_bound_ca = (uint8_t)rack_clamp_ca_upper;
5649 				/* Now move to the lt_bw */
5650 				rack->r_ctl.gp_bw = lt_bw;
5651 				rack->rc_gp_filled = 1;
5652 				rack->r_ctl.num_measurements = RACK_REQ_AVG;
5653 			}
5654 			if (tcp_bblogging_on(rack->rc_tp)) {
5655 				union tcp_log_stackspecific log;
5656 				struct timeval tv;
5657 
5658 				memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5659 				log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5660 				log.u_bbr.flex1 = new_cwnd;
5661 				log.u_bbr.flex2 = new_ssthresh;
5662 				log.u_bbr.flex3 = rnds;
5663 				log.u_bbr.flex4 = rack_rxt_min_rnds;
5664 				log.u_bbr.flex5 = rtt;
5665 				log.u_bbr.flex6 = shared_cwnd_was_enabled;
5666 				log.u_bbr.flex8 = 5;
5667 				log.u_bbr.pkt_epoch = rack->r_ctl.rc_pace_max_segs;
5668 				log.u_bbr.bbr_state = rack->rc_pace_to_cwnd;
5669 				log.u_bbr.delivered = rack->r_ctl.num_of_clamps_applied;
5670 				log.u_bbr.applimited = rack->r_ctl.max_clamps;
5671 				log.u_bbr.epoch = rack->r_ctl.clamp_options;
5672 				log.u_bbr.cur_del_rate = rxts;
5673 				log.u_bbr.delRate = snds;
5674 				log.u_bbr.rttProp = rack->r_ctl.rxt_threshold;
5675 				log.u_bbr.bw_inuse = lt_bw;
5676 				log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
5677 				log.u_bbr.lt_epoch = (uint32_t)((rack->r_ctl.gp_bw >> 32) & 0x00000000ffffffff);
5678 				log.u_bbr.pkts_out = (uint32_t)(rack->r_ctl.gp_bw & 0x00000000ffffffff);
5679 				tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
5680 					       0, &log, false, NULL, NULL, 0, &tv);
5681 			}
5682 			/* Update our point where we did it */
5683 			if (rack->r_ctl.already_had_a_excess == 0) {
5684 				rack->r_ctl.already_had_a_excess = 1;
5685 				counter_u64_add(rack_rxt_clamps_cwnd_uniq, 1);
5686 			}
5687 			counter_u64_add(rack_rxt_clamps_cwnd, 1);
5688 			rack->r_ctl.last_sndbytes = tp->t_sndbytes;
5689 			rack->r_ctl.last_snd_rxt_bytes = tp->t_snd_rxt_bytes;
5690 			rack->r_ctl.last_rnd_rxt_clamped = rack->r_ctl.current_round;
5691 			if (new_cwnd < tp->snd_cwnd)
5692 				tp->snd_cwnd = new_cwnd;
5693 			if (new_ssthresh < tp->snd_ssthresh)
5694 				tp->snd_ssthresh = new_ssthresh;
5695 		}
5696 	}
5697 }
5698 
5699 static void
5700 rack_post_recovery(struct tcpcb *tp, uint32_t th_ack)
5701 {
5702 	struct tcp_rack *rack;
5703 	uint32_t orig_cwnd;
5704 
5705 	orig_cwnd = tp->snd_cwnd;
5706 	INP_WLOCK_ASSERT(tptoinpcb(tp));
5707 	rack = (struct tcp_rack *)tp->t_fb_ptr;
5708 	/* only alert CC if we alerted when we entered */
5709 	if (CC_ALGO(tp)->post_recovery != NULL) {
5710 		tp->t_ccv.curack = th_ack;
5711 		CC_ALGO(tp)->post_recovery(&tp->t_ccv);
5712 		if (tp->snd_cwnd < tp->snd_ssthresh) {
5713 			/*
5714 			 * Rack has burst control and pacing
5715 			 * so lets not set this any lower than
5716 			 * snd_ssthresh per RFC-6582 (option 2).
5717 			 */
5718 			tp->snd_cwnd = tp->snd_ssthresh;
5719 		}
5720 	}
5721 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
5722 		union tcp_log_stackspecific log;
5723 		struct timeval tv;
5724 
5725 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5726 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5727 		log.u_bbr.flex1 = th_ack;
5728 		log.u_bbr.flex2 = tp->t_ccv.flags;
5729 		log.u_bbr.flex3 = tp->t_ccv.bytes_this_ack;
5730 		log.u_bbr.flex4 = tp->t_ccv.nsegs;
5731 		log.u_bbr.flex5 = V_tcp_abc_l_var;
5732 		log.u_bbr.flex6 = orig_cwnd;
5733 		log.u_bbr.flex7 = V_tcp_do_newsack;
5734 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
5735 		log.u_bbr.flex8 = 2;
5736 		tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
5737 			       0, &log, false, NULL, __func__, __LINE__, &tv);
5738 	}
5739 	if ((rack->rack_no_prr == 0) &&
5740 	    (rack->no_prr_addback == 0) &&
5741 	    (rack->r_ctl.rc_prr_sndcnt > 0)) {
5742 		/*
5743 		 * Suck the next prr cnt back into cwnd, but
5744 		 * only do that if we are not application limited.
5745 		 */
5746 		if (ctf_outstanding(tp) <= sbavail(&tptosocket(tp)->so_snd)) {
5747 			/*
5748 			 * We are allowed to add back to the cwnd the amount we did
5749 			 * not get out if:
5750 			 * a) no_prr_addback is off.
5751 			 * b) we are not app limited
5752 			 * c) we are doing prr
5753 			 * <and>
5754 			 * d) it is bounded by rack_prr_addbackmax (if addback is 0, then none).
5755 			 */
5756 			tp->snd_cwnd += min((ctf_fixed_maxseg(tp) * rack_prr_addbackmax),
5757 					    rack->r_ctl.rc_prr_sndcnt);
5758 		}
5759 		rack->r_ctl.rc_prr_sndcnt = 0;
5760 		rack_log_to_prr(rack, 1, 0, __LINE__);
5761 	}
5762 	rack_log_to_prr(rack, 14, orig_cwnd, __LINE__);
5763 	tp->snd_recover = tp->snd_una;
5764 	if (rack->r_ctl.dsack_persist) {
5765 		rack->r_ctl.dsack_persist--;
5766 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
5767 			rack->r_ctl.num_dsack = 0;
5768 		}
5769 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
5770 	}
5771 	EXIT_RECOVERY(tp->t_flags);
5772 	if (rack->r_ctl.full_dgp_in_rec)
5773 		rack_client_buffer_level_set(rack);
5774 }
5775 
5776 static void
5777 rack_cong_signal(struct tcpcb *tp, uint32_t type, uint32_t ack, int line)
5778 {
5779 	struct tcp_rack *rack;
5780 	uint32_t ssthresh_enter, cwnd_enter, in_rec_at_entry, orig_cwnd;
5781 
5782 	INP_WLOCK_ASSERT(tptoinpcb(tp));
5783 #ifdef STATS
5784 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_CSIG, type);
5785 #endif
5786 	if (IN_RECOVERY(tp->t_flags) == 0) {
5787 		in_rec_at_entry = 0;
5788 		ssthresh_enter = tp->snd_ssthresh;
5789 		cwnd_enter = tp->snd_cwnd;
5790 	} else
5791 		in_rec_at_entry = 1;
5792 	rack = (struct tcp_rack *)tp->t_fb_ptr;
5793 	switch (type) {
5794 	case CC_NDUPACK:
5795 		tp->t_flags &= ~TF_WASFRECOVERY;
5796 		tp->t_flags &= ~TF_WASCRECOVERY;
5797 		if (!IN_FASTRECOVERY(tp->t_flags)) {
5798 			if (rack->dgp_on && rack->r_cwnd_was_clamped) {
5799 				/* Reset the gains so that on exit we will be softer longer */
5800 				rack->r_ctl.rack_per_of_gp_rec = 100;
5801 				rack->r_ctl.rack_per_of_gp_ss = 98;
5802 				rack->r_ctl.rack_per_of_gp_ca = 98;
5803 			}
5804 			rack->r_ctl.rc_prr_delivered = 0;
5805 			rack->r_ctl.rc_prr_out = 0;
5806 			rack->r_fast_output = 0;
5807 			if (rack->rack_no_prr == 0) {
5808 				rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
5809 				rack_log_to_prr(rack, 2, in_rec_at_entry, line);
5810 			}
5811 			rack->r_ctl.rc_prr_recovery_fs = tp->snd_max - tp->snd_una;
5812 			tp->snd_recover = tp->snd_max;
5813 			if (tp->t_flags2 & TF2_ECN_PERMIT)
5814 				tp->t_flags2 |= TF2_ECN_SND_CWR;
5815 		}
5816 		break;
5817 	case CC_ECN:
5818 		if (!IN_CONGRECOVERY(tp->t_flags) ||
5819 		    /*
5820 		     * Allow ECN reaction on ACK to CWR, if
5821 		     * that data segment was also CE marked.
5822 		     */
5823 		    SEQ_GEQ(ack, tp->snd_recover)) {
5824 			EXIT_CONGRECOVERY(tp->t_flags);
5825 			KMOD_TCPSTAT_INC(tcps_ecn_rcwnd);
5826 			rack->r_fast_output = 0;
5827 			tp->snd_recover = tp->snd_max + 1;
5828 			if (tp->t_flags2 & TF2_ECN_PERMIT)
5829 				tp->t_flags2 |= TF2_ECN_SND_CWR;
5830 		}
5831 		break;
5832 	case CC_RTO:
5833 		tp->t_dupacks = 0;
5834 		tp->t_bytes_acked = 0;
5835 		rack->r_fast_output = 0;
5836 		EXIT_RECOVERY(tp->t_flags);
5837 		tp->snd_ssthresh = max(2, min(tp->snd_wnd, rack->r_ctl.cwnd_to_use) / 2 /
5838 		    ctf_fixed_maxseg(tp)) * ctf_fixed_maxseg(tp);
5839 		orig_cwnd = tp->snd_cwnd;
5840 		tp->snd_cwnd = ctf_fixed_maxseg(tp);
5841 		rack_log_to_prr(rack, 16, orig_cwnd, line);
5842 		if (tp->t_flags2 & TF2_ECN_PERMIT)
5843 			tp->t_flags2 |= TF2_ECN_SND_CWR;
5844 		break;
5845 	case CC_RTO_ERR:
5846 		KMOD_TCPSTAT_INC(tcps_sndrexmitbad);
5847 		/* RTO was unnecessary, so reset everything. */
5848 		tp->snd_cwnd = tp->snd_cwnd_prev;
5849 		tp->snd_ssthresh = tp->snd_ssthresh_prev;
5850 		tp->snd_recover = tp->snd_recover_prev;
5851 		if (tp->t_flags & TF_WASFRECOVERY) {
5852 			ENTER_FASTRECOVERY(tp->t_flags);
5853 			tp->t_flags &= ~TF_WASFRECOVERY;
5854 		}
5855 		if (tp->t_flags & TF_WASCRECOVERY) {
5856 			ENTER_CONGRECOVERY(tp->t_flags);
5857 			tp->t_flags &= ~TF_WASCRECOVERY;
5858 		}
5859 		tp->snd_nxt = tp->snd_max;
5860 		tp->t_badrxtwin = 0;
5861 		break;
5862 	}
5863 	if ((CC_ALGO(tp)->cong_signal != NULL)  &&
5864 	    (type != CC_RTO)){
5865 		tp->t_ccv.curack = ack;
5866 		CC_ALGO(tp)->cong_signal(&tp->t_ccv, type);
5867 	}
5868 	if ((in_rec_at_entry == 0) && IN_RECOVERY(tp->t_flags)) {
5869 		rack_log_to_prr(rack, 15, cwnd_enter, line);
5870 		if (rack->r_ctl.full_dgp_in_rec)
5871 			rack_client_buffer_level_set(rack);
5872 		rack->r_ctl.dsack_byte_cnt = 0;
5873 		rack->r_ctl.retran_during_recovery = 0;
5874 		rack->r_ctl.rc_cwnd_at_erec = cwnd_enter;
5875 		rack->r_ctl.rc_ssthresh_at_erec = ssthresh_enter;
5876 		rack->r_ent_rec_ns = 1;
5877 	}
5878 }
5879 
5880 static inline void
5881 rack_cc_after_idle(struct tcp_rack *rack, struct tcpcb *tp)
5882 {
5883 	uint32_t i_cwnd;
5884 
5885 	INP_WLOCK_ASSERT(tptoinpcb(tp));
5886 
5887 	if (CC_ALGO(tp)->after_idle != NULL)
5888 		CC_ALGO(tp)->after_idle(&tp->t_ccv);
5889 
5890 	if (tp->snd_cwnd == 1)
5891 		i_cwnd = tp->t_maxseg;		/* SYN(-ACK) lost */
5892 	else
5893 		i_cwnd = rc_init_window(rack);
5894 
5895 	/*
5896 	 * Being idle is no different than the initial window. If the cc
5897 	 * clamps it down below the initial window raise it to the initial
5898 	 * window.
5899 	 */
5900 	if (tp->snd_cwnd < i_cwnd) {
5901 		tp->snd_cwnd = i_cwnd;
5902 	}
5903 }
5904 
5905 /*
5906  * Indicate whether this ack should be delayed.  We can delay the ack if
5907  * following conditions are met:
5908  *	- There is no delayed ack timer in progress.
5909  *	- Our last ack wasn't a 0-sized window. We never want to delay
5910  *	  the ack that opens up a 0-sized window.
5911  *	- LRO wasn't used for this segment. We make sure by checking that the
5912  *	  segment size is not larger than the MSS.
5913  *	- Delayed acks are enabled or this is a half-synchronized T/TCP
5914  *	  connection.
5915  */
5916 #define DELAY_ACK(tp, tlen)			 \
5917 	(((tp->t_flags & TF_RXWIN0SENT) == 0) && \
5918 	((tp->t_flags & TF_DELACK) == 0) &&	 \
5919 	(tlen <= tp->t_maxseg) &&		 \
5920 	(tp->t_delayed_ack || (tp->t_flags & TF_NEEDSYN)))
5921 
5922 static struct rack_sendmap *
5923 rack_find_lowest_rsm(struct tcp_rack *rack)
5924 {
5925 	struct rack_sendmap *rsm;
5926 
5927 	/*
5928 	 * Walk the time-order transmitted list looking for an rsm that is
5929 	 * not acked. This will be the one that was sent the longest time
5930 	 * ago that is still outstanding.
5931 	 */
5932 	TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
5933 		if (rsm->r_flags & RACK_ACKED) {
5934 			continue;
5935 		}
5936 		goto finish;
5937 	}
5938 finish:
5939 	return (rsm);
5940 }
5941 
5942 static struct rack_sendmap *
5943 rack_find_high_nonack(struct tcp_rack *rack, struct rack_sendmap *rsm)
5944 {
5945 	struct rack_sendmap *prsm;
5946 
5947 	/*
5948 	 * Walk the sequence order list backward until we hit and arrive at
5949 	 * the highest seq not acked. In theory when this is called it
5950 	 * should be the last segment (which it was not).
5951 	 */
5952 	prsm = rsm;
5953 
5954 	TQHASH_FOREACH_REVERSE_FROM(prsm, rack->r_ctl.tqh) {
5955 		if (prsm->r_flags & (RACK_ACKED | RACK_HAS_FIN)) {
5956 			continue;
5957 		}
5958 		return (prsm);
5959 	}
5960 	return (NULL);
5961 }
5962 
5963 static uint32_t
5964 rack_calc_thresh_rack(struct tcp_rack *rack, uint32_t srtt, uint32_t cts)
5965 {
5966 	int32_t lro;
5967 	uint32_t thresh;
5968 
5969 	/*
5970 	 * lro is the flag we use to determine if we have seen reordering.
5971 	 * If it gets set we have seen reordering. The reorder logic either
5972 	 * works in one of two ways:
5973 	 *
5974 	 * If reorder-fade is configured, then we track the last time we saw
5975 	 * re-ordering occur. If we reach the point where enough time as
5976 	 * passed we no longer consider reordering has occuring.
5977 	 *
5978 	 * Or if reorder-face is 0, then once we see reordering we consider
5979 	 * the connection to alway be subject to reordering and just set lro
5980 	 * to 1.
5981 	 *
5982 	 * In the end if lro is non-zero we add the extra time for
5983 	 * reordering in.
5984 	 */
5985 	if (srtt == 0)
5986 		srtt = 1;
5987 	if (rack->r_ctl.rc_reorder_ts) {
5988 		if (rack->r_ctl.rc_reorder_fade) {
5989 			if (SEQ_GEQ(cts, rack->r_ctl.rc_reorder_ts)) {
5990 				lro = cts - rack->r_ctl.rc_reorder_ts;
5991 				if (lro == 0) {
5992 					/*
5993 					 * No time as passed since the last
5994 					 * reorder, mark it as reordering.
5995 					 */
5996 					lro = 1;
5997 				}
5998 			} else {
5999 				/* Negative time? */
6000 				lro = 0;
6001 			}
6002 			if (lro > rack->r_ctl.rc_reorder_fade) {
6003 				/* Turn off reordering seen too */
6004 				rack->r_ctl.rc_reorder_ts = 0;
6005 				lro = 0;
6006 			}
6007 		} else {
6008 			/* Reodering does not fade */
6009 			lro = 1;
6010 		}
6011 	} else {
6012 		lro = 0;
6013 	}
6014 	if (rack->rc_rack_tmr_std_based == 0) {
6015 		thresh = srtt + rack->r_ctl.rc_pkt_delay;
6016 	} else {
6017 		/* Standards based pkt-delay is 1/4 srtt */
6018 		thresh = srtt +  (srtt >> 2);
6019 	}
6020 	if (lro && (rack->rc_rack_tmr_std_based == 0)) {
6021 		/* It must be set, if not you get 1/4 rtt */
6022 		if (rack->r_ctl.rc_reorder_shift)
6023 			thresh += (srtt >> rack->r_ctl.rc_reorder_shift);
6024 		else
6025 			thresh += (srtt >> 2);
6026 	}
6027 	if (rack->rc_rack_use_dsack &&
6028 	    lro &&
6029 	    (rack->r_ctl.num_dsack > 0)) {
6030 		/*
6031 		 * We only increase the reordering window if we
6032 		 * have seen reordering <and> we have a DSACK count.
6033 		 */
6034 		thresh += rack->r_ctl.num_dsack * (srtt >> 2);
6035 		rack_log_dsack_event(rack, 4, __LINE__, srtt, thresh);
6036 	}
6037 	/* SRTT * 2 is the ceiling */
6038 	if (thresh > (srtt * 2)) {
6039 		thresh = srtt * 2;
6040 	}
6041 	/* And we don't want it above the RTO max either */
6042 	if (thresh > rack_rto_max) {
6043 		thresh = rack_rto_max;
6044 	}
6045 	rack_log_dsack_event(rack, 6, __LINE__, srtt, thresh);
6046 	return (thresh);
6047 }
6048 
6049 static uint32_t
6050 rack_calc_thresh_tlp(struct tcpcb *tp, struct tcp_rack *rack,
6051 		     struct rack_sendmap *rsm, uint32_t srtt)
6052 {
6053 	struct rack_sendmap *prsm;
6054 	uint32_t thresh, len;
6055 	int segsiz;
6056 
6057 	if (srtt == 0)
6058 		srtt = 1;
6059 	if (rack->r_ctl.rc_tlp_threshold)
6060 		thresh = srtt + (srtt / rack->r_ctl.rc_tlp_threshold);
6061 	else
6062 		thresh = (srtt * 2);
6063 
6064 	/* Get the previous sent packet, if any */
6065 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
6066 	len = rsm->r_end - rsm->r_start;
6067 	if (rack->rack_tlp_threshold_use == TLP_USE_ID) {
6068 		/* Exactly like the ID */
6069 		if (((tp->snd_max - tp->snd_una) - rack->r_ctl.rc_sacked + rack->r_ctl.rc_holes_rxt) <= segsiz) {
6070 			uint32_t alt_thresh;
6071 			/*
6072 			 * Compensate for delayed-ack with the d-ack time.
6073 			 */
6074 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
6075 			if (alt_thresh > thresh)
6076 				thresh = alt_thresh;
6077 		}
6078 	} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_ONE) {
6079 		/* 2.1 behavior */
6080 		prsm = TAILQ_PREV(rsm, rack_head, r_tnext);
6081 		if (prsm && (len <= segsiz)) {
6082 			/*
6083 			 * Two packets outstanding, thresh should be (2*srtt) +
6084 			 * possible inter-packet delay (if any).
6085 			 */
6086 			uint32_t inter_gap = 0;
6087 			int idx, nidx;
6088 
6089 			idx = rsm->r_rtr_cnt - 1;
6090 			nidx = prsm->r_rtr_cnt - 1;
6091 			if (rsm->r_tim_lastsent[nidx] >= prsm->r_tim_lastsent[idx]) {
6092 				/* Yes it was sent later (or at the same time) */
6093 				inter_gap = rsm->r_tim_lastsent[idx] - prsm->r_tim_lastsent[nidx];
6094 			}
6095 			thresh += inter_gap;
6096 		} else if (len <= segsiz) {
6097 			/*
6098 			 * Possibly compensate for delayed-ack.
6099 			 */
6100 			uint32_t alt_thresh;
6101 
6102 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
6103 			if (alt_thresh > thresh)
6104 				thresh = alt_thresh;
6105 		}
6106 	} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_TWO) {
6107 		/* 2.2 behavior */
6108 		if (len <= segsiz) {
6109 			uint32_t alt_thresh;
6110 			/*
6111 			 * Compensate for delayed-ack with the d-ack time.
6112 			 */
6113 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
6114 			if (alt_thresh > thresh)
6115 				thresh = alt_thresh;
6116 		}
6117 	}
6118 	/* Not above an RTO */
6119 	if (thresh > tp->t_rxtcur) {
6120 		thresh = tp->t_rxtcur;
6121 	}
6122 	/* Not above a RTO max */
6123 	if (thresh > rack_rto_max) {
6124 		thresh = rack_rto_max;
6125 	}
6126 	/* Apply user supplied min TLP */
6127 	if (thresh < rack_tlp_min) {
6128 		thresh = rack_tlp_min;
6129 	}
6130 	return (thresh);
6131 }
6132 
6133 static uint32_t
6134 rack_grab_rtt(struct tcpcb *tp, struct tcp_rack *rack)
6135 {
6136 	/*
6137 	 * We want the rack_rtt which is the
6138 	 * last rtt we measured. However if that
6139 	 * does not exist we fallback to the srtt (which
6140 	 * we probably will never do) and then as a last
6141 	 * resort we use RACK_INITIAL_RTO if no srtt is
6142 	 * yet set.
6143 	 */
6144 	if (rack->rc_rack_rtt)
6145 		return (rack->rc_rack_rtt);
6146 	else if (tp->t_srtt == 0)
6147 		return (RACK_INITIAL_RTO);
6148 	return (tp->t_srtt);
6149 }
6150 
6151 static struct rack_sendmap *
6152 rack_check_recovery_mode(struct tcpcb *tp, uint32_t tsused)
6153 {
6154 	/*
6155 	 * Check to see that we don't need to fall into recovery. We will
6156 	 * need to do so if our oldest transmit is past the time we should
6157 	 * have had an ack.
6158 	 */
6159 	struct tcp_rack *rack;
6160 	struct rack_sendmap *rsm;
6161 	int32_t idx;
6162 	uint32_t srtt, thresh;
6163 
6164 	rack = (struct tcp_rack *)tp->t_fb_ptr;
6165 	if (tqhash_empty(rack->r_ctl.tqh)) {
6166 		return (NULL);
6167 	}
6168 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
6169 	if (rsm == NULL)
6170 		return (NULL);
6171 
6172 
6173 	if (rsm->r_flags & RACK_ACKED) {
6174 		rsm = rack_find_lowest_rsm(rack);
6175 		if (rsm == NULL)
6176 			return (NULL);
6177 	}
6178 	idx = rsm->r_rtr_cnt - 1;
6179 	srtt = rack_grab_rtt(tp, rack);
6180 	thresh = rack_calc_thresh_rack(rack, srtt, tsused);
6181 	if (TSTMP_LT(tsused, ((uint32_t)rsm->r_tim_lastsent[idx]))) {
6182 		return (NULL);
6183 	}
6184 	if ((tsused - ((uint32_t)rsm->r_tim_lastsent[idx])) < thresh) {
6185 		return (NULL);
6186 	}
6187 	/* Ok if we reach here we are over-due and this guy can be sent */
6188 	rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
6189 	return (rsm);
6190 }
6191 
6192 static uint32_t
6193 rack_get_persists_timer_val(struct tcpcb *tp, struct tcp_rack *rack)
6194 {
6195 	int32_t t;
6196 	int32_t tt;
6197 	uint32_t ret_val;
6198 
6199 	t = (tp->t_srtt + (tp->t_rttvar << 2));
6200 	RACK_TCPT_RANGESET(tt, t * tcp_backoff[tp->t_rxtshift],
6201  	    rack_persist_min, rack_persist_max, rack->r_ctl.timer_slop);
6202 	rack->r_ctl.rc_hpts_flags |= PACE_TMR_PERSIT;
6203 	ret_val = (uint32_t)tt;
6204 	return (ret_val);
6205 }
6206 
6207 static uint32_t
6208 rack_timer_start(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int sup_rack)
6209 {
6210 	/*
6211 	 * Start the FR timer, we do this based on getting the first one in
6212 	 * the rc_tmap. Note that if its NULL we must stop the timer. in all
6213 	 * events we need to stop the running timer (if its running) before
6214 	 * starting the new one.
6215 	 */
6216 	uint32_t thresh, exp, to, srtt, time_since_sent, tstmp_touse;
6217 	uint32_t srtt_cur;
6218 	int32_t idx;
6219 	int32_t is_tlp_timer = 0;
6220 	struct rack_sendmap *rsm;
6221 
6222 	if (rack->t_timers_stopped) {
6223 		/* All timers have been stopped none are to run */
6224 		return (0);
6225 	}
6226 	if (rack->rc_in_persist) {
6227 		/* We can't start any timer in persists */
6228 		return (rack_get_persists_timer_val(tp, rack));
6229 	}
6230 	rack->rc_on_min_to = 0;
6231 	if ((tp->t_state < TCPS_ESTABLISHED) ||
6232 	    (rack->sack_attack_disable > 0) ||
6233 	    ((tp->t_flags & TF_SACK_PERMIT) == 0)) {
6234 		goto activate_rxt;
6235 	}
6236 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
6237 	if ((rsm == NULL) || sup_rack) {
6238 		/* Nothing on the send map or no rack */
6239 activate_rxt:
6240 		time_since_sent = 0;
6241 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
6242 		if (rsm) {
6243 			/*
6244 			 * Should we discount the RTX timer any?
6245 			 *
6246 			 * We want to discount it the smallest amount.
6247 			 * If a timer (Rack/TLP or RXT) has gone off more
6248 			 * recently thats the discount we want to use (now - timer time).
6249 			 * If the retransmit of the oldest packet was more recent then
6250 			 * we want to use that (now - oldest-packet-last_transmit_time).
6251 			 *
6252 			 */
6253 			idx = rsm->r_rtr_cnt - 1;
6254 			if (TSTMP_GEQ(rack->r_ctl.rc_tlp_rxt_last_time, ((uint32_t)rsm->r_tim_lastsent[idx])))
6255 				tstmp_touse = (uint32_t)rack->r_ctl.rc_tlp_rxt_last_time;
6256 			else
6257 				tstmp_touse = (uint32_t)rsm->r_tim_lastsent[idx];
6258 			if (TSTMP_GT(cts, tstmp_touse))
6259 			    time_since_sent = cts - tstmp_touse;
6260 		}
6261 		if (SEQ_LT(tp->snd_una, tp->snd_max) ||
6262 		    sbavail(&tptosocket(tp)->so_snd)) {
6263 			rack->r_ctl.rc_hpts_flags |= PACE_TMR_RXT;
6264 			to = tp->t_rxtcur;
6265 			if (to > time_since_sent)
6266 				to -= time_since_sent;
6267 			else
6268 				to = rack->r_ctl.rc_min_to;
6269 			if (to == 0)
6270 				to = 1;
6271 			/* Special case for KEEPINIT */
6272 			if ((TCPS_HAVEESTABLISHED(tp->t_state) == 0) &&
6273 			    (TP_KEEPINIT(tp) != 0) &&
6274 			    rsm) {
6275 				/*
6276 				 * We have to put a ceiling on the rxt timer
6277 				 * of the keep-init timeout.
6278 				 */
6279 				uint32_t max_time, red;
6280 
6281 				max_time = TICKS_2_USEC(TP_KEEPINIT(tp));
6282 				if (TSTMP_GT(cts, (uint32_t)rsm->r_tim_lastsent[0])) {
6283 					red = (cts - (uint32_t)rsm->r_tim_lastsent[0]);
6284 					if (red < max_time)
6285 						max_time -= red;
6286 					else
6287 						max_time = 1;
6288 				}
6289 				/* Reduce timeout to the keep value if needed */
6290 				if (max_time < to)
6291 					to = max_time;
6292 			}
6293 			return (to);
6294 		}
6295 		return (0);
6296 	}
6297 	if (rsm->r_flags & RACK_ACKED) {
6298 		rsm = rack_find_lowest_rsm(rack);
6299 		if (rsm == NULL) {
6300 			/* No lowest? */
6301 			goto activate_rxt;
6302 		}
6303 	}
6304 	if (rack->sack_attack_disable) {
6305 		/*
6306 		 * We don't want to do
6307 		 * any TLP's if you are an attacker.
6308 		 * Though if you are doing what
6309 		 * is expected you may still have
6310 		 * SACK-PASSED marks.
6311 		 */
6312 		goto activate_rxt;
6313 	}
6314 	/* Convert from ms to usecs */
6315 	if ((rsm->r_flags & RACK_SACK_PASSED) ||
6316 	    (rsm->r_flags & RACK_RWND_COLLAPSED) ||
6317 	    (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
6318 		if ((tp->t_flags & TF_SENTFIN) &&
6319 		    ((tp->snd_max - tp->snd_una) == 1) &&
6320 		    (rsm->r_flags & RACK_HAS_FIN)) {
6321 			/*
6322 			 * We don't start a rack timer if all we have is a
6323 			 * FIN outstanding.
6324 			 */
6325 			goto activate_rxt;
6326 		}
6327 		if ((rack->use_rack_rr == 0) &&
6328 		    (IN_FASTRECOVERY(tp->t_flags)) &&
6329 		    (rack->rack_no_prr == 0) &&
6330 		     (rack->r_ctl.rc_prr_sndcnt  < ctf_fixed_maxseg(tp))) {
6331 			/*
6332 			 * We are not cheating, in recovery  and
6333 			 * not enough ack's to yet get our next
6334 			 * retransmission out.
6335 			 *
6336 			 * Note that classified attackers do not
6337 			 * get to use the rack-cheat.
6338 			 */
6339 			goto activate_tlp;
6340 		}
6341 		srtt = rack_grab_rtt(tp, rack);
6342 		thresh = rack_calc_thresh_rack(rack, srtt, cts);
6343 		idx = rsm->r_rtr_cnt - 1;
6344 		exp = ((uint32_t)rsm->r_tim_lastsent[idx]) + thresh;
6345 		if (SEQ_GEQ(exp, cts)) {
6346 			to = exp - cts;
6347 			if (to < rack->r_ctl.rc_min_to) {
6348 				to = rack->r_ctl.rc_min_to;
6349 				if (rack->r_rr_config == 3)
6350 					rack->rc_on_min_to = 1;
6351 			}
6352 		} else {
6353 			to = rack->r_ctl.rc_min_to;
6354 			if (rack->r_rr_config == 3)
6355 				rack->rc_on_min_to = 1;
6356 		}
6357 	} else {
6358 		/* Ok we need to do a TLP not RACK */
6359 activate_tlp:
6360 		if ((rack->rc_tlp_in_progress != 0) &&
6361 		    (rack->r_ctl.rc_tlp_cnt_out >= rack_tlp_limit)) {
6362 			/*
6363 			 * The previous send was a TLP and we have sent
6364 			 * N TLP's without sending new data.
6365 			 */
6366 			goto activate_rxt;
6367 		}
6368 		rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
6369 		if (rsm == NULL) {
6370 			/* We found no rsm to TLP with. */
6371 			goto activate_rxt;
6372 		}
6373 		if (rsm->r_flags & RACK_HAS_FIN) {
6374 			/* If its a FIN we dont do TLP */
6375 			rsm = NULL;
6376 			goto activate_rxt;
6377 		}
6378 		idx = rsm->r_rtr_cnt - 1;
6379 		time_since_sent = 0;
6380 		if (TSTMP_GEQ(((uint32_t)rsm->r_tim_lastsent[idx]), rack->r_ctl.rc_tlp_rxt_last_time))
6381 			tstmp_touse = (uint32_t)rsm->r_tim_lastsent[idx];
6382 		else
6383 			tstmp_touse = (uint32_t)rack->r_ctl.rc_tlp_rxt_last_time;
6384 		if (TSTMP_GT(cts, tstmp_touse))
6385 		    time_since_sent = cts - tstmp_touse;
6386 		is_tlp_timer = 1;
6387 		if (tp->t_srtt) {
6388 			if ((rack->rc_srtt_measure_made == 0) &&
6389 			    (tp->t_srtt == 1)) {
6390 				/*
6391 				 * If another stack as run and set srtt to 1,
6392 				 * then the srtt was 0, so lets use the initial.
6393 				 */
6394 				srtt = RACK_INITIAL_RTO;
6395 			} else {
6396 				srtt_cur = tp->t_srtt;
6397 				srtt = srtt_cur;
6398 			}
6399 		} else
6400 			srtt = RACK_INITIAL_RTO;
6401 		/*
6402 		 * If the SRTT is not keeping up and the
6403 		 * rack RTT has spiked we want to use
6404 		 * the last RTT not the smoothed one.
6405 		 */
6406 		if (rack_tlp_use_greater &&
6407 		    tp->t_srtt &&
6408 		    (srtt < rack_grab_rtt(tp, rack))) {
6409 			srtt = rack_grab_rtt(tp, rack);
6410 		}
6411 		thresh = rack_calc_thresh_tlp(tp, rack, rsm, srtt);
6412 		if (thresh > time_since_sent) {
6413 			to = thresh - time_since_sent;
6414 		} else {
6415 			to = rack->r_ctl.rc_min_to;
6416 			rack_log_alt_to_to_cancel(rack,
6417 						  thresh,		/* flex1 */
6418 						  time_since_sent,	/* flex2 */
6419 						  tstmp_touse,		/* flex3 */
6420 						  rack->r_ctl.rc_tlp_rxt_last_time, /* flex4 */
6421 						  (uint32_t)rsm->r_tim_lastsent[idx],
6422 						  srtt,
6423 						  idx, 99);
6424 		}
6425 		if (to < rack_tlp_min) {
6426 			to = rack_tlp_min;
6427 		}
6428 		if (to > TICKS_2_USEC(TCPTV_REXMTMAX)) {
6429 			/*
6430 			 * If the TLP time works out to larger than the max
6431 			 * RTO lets not do TLP.. just RTO.
6432 			 */
6433 			goto activate_rxt;
6434 		}
6435 	}
6436 	if (is_tlp_timer == 0) {
6437 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_RACK;
6438 	} else {
6439 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_TLP;
6440 	}
6441 	if (to == 0)
6442 		to = 1;
6443 	return (to);
6444 }
6445 
6446 static void
6447 rack_enter_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, tcp_seq snd_una)
6448 {
6449 	struct timeval tv;
6450 
6451 	if (rack->rc_in_persist == 0) {
6452 		if (tp->t_flags & TF_GPUTINPROG) {
6453 			/*
6454 			 * Stop the goodput now, the calling of the
6455 			 * measurement function clears the flag.
6456 			 */
6457 			rack_do_goodput_measurement(tp, rack, tp->snd_una, __LINE__,
6458 						    RACK_QUALITY_PERSIST);
6459 		}
6460 #ifdef NETFLIX_SHARED_CWND
6461 		if (rack->r_ctl.rc_scw) {
6462 			tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
6463 			rack->rack_scwnd_is_idle = 1;
6464 		}
6465 #endif
6466 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(&tv);
6467 		if (rack->lt_bw_up) {
6468 			/* Suspend our LT BW measurement */
6469 			uint64_t tmark;
6470 
6471 			rack->r_ctl.lt_bw_bytes += (snd_una - rack->r_ctl.lt_seq);
6472 			rack->r_ctl.lt_seq = snd_una;
6473 			tmark = tcp_tv_to_lusectick(&tv);
6474 			rack->r_ctl.lt_bw_time += (tmark - rack->r_ctl.lt_timemark);
6475 			rack->r_ctl.lt_timemark = tmark;
6476 			rack->lt_bw_up = 0;
6477 			rack->r_persist_lt_bw_off = 1;
6478 		}
6479 		if (rack->r_ctl.rc_went_idle_time == 0)
6480 			rack->r_ctl.rc_went_idle_time = 1;
6481 		rack_timer_cancel(tp, rack, cts, __LINE__);
6482 		rack->r_ctl.persist_lost_ends = 0;
6483 		rack->probe_not_answered = 0;
6484 		rack->forced_ack = 0;
6485 		tp->t_rxtshift = 0;
6486 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
6487 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
6488 		rack->rc_in_persist = 1;
6489 	}
6490 }
6491 
6492 static void
6493 rack_exit_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6494 {
6495 	struct timeval tv;
6496 	uint32_t t_time;
6497 
6498 	if (tcp_in_hpts(rack->rc_inp)) {
6499 		tcp_hpts_remove(rack->rc_inp);
6500 		rack->r_ctl.rc_hpts_flags = 0;
6501 	}
6502 #ifdef NETFLIX_SHARED_CWND
6503 	if (rack->r_ctl.rc_scw) {
6504 		tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
6505 		rack->rack_scwnd_is_idle = 0;
6506 	}
6507 #endif
6508 	t_time = tcp_get_usecs(&tv);
6509 	if (rack->rc_gp_dyn_mul &&
6510 	    (rack->use_fixed_rate == 0) &&
6511 	    (rack->rc_always_pace)) {
6512 		/*
6513 		 * Do we count this as if a probe-rtt just
6514 		 * finished?
6515 		 */
6516 		uint32_t time_idle, idle_min;
6517 
6518 		time_idle = t_time - rack->r_ctl.rc_went_idle_time;
6519 		idle_min = rack_min_probertt_hold;
6520 		if (rack_probertt_gpsrtt_cnt_div) {
6521 			uint64_t extra;
6522 			extra = (uint64_t)rack->r_ctl.rc_gp_srtt *
6523 				(uint64_t)rack_probertt_gpsrtt_cnt_mul;
6524 			extra /= (uint64_t)rack_probertt_gpsrtt_cnt_div;
6525 			idle_min += (uint32_t)extra;
6526 		}
6527 		if (time_idle >= idle_min) {
6528 			/* Yes, we count it as a probe-rtt. */
6529 			uint32_t us_cts;
6530 
6531 			us_cts = tcp_get_usecs(NULL);
6532 			if (rack->in_probe_rtt == 0) {
6533 				rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
6534 				rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
6535 				rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
6536 				rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
6537 			} else {
6538 				rack_exit_probertt(rack, us_cts);
6539 			}
6540 		}
6541 	}
6542 	if (rack->r_persist_lt_bw_off) {
6543 		/* Continue where we left off */
6544 		rack->r_ctl.lt_timemark = tcp_tv_to_lusectick(&tv);
6545 		rack->lt_bw_up = 1;
6546 		rack->r_persist_lt_bw_off = 0;
6547 	}
6548 	rack->rc_in_persist = 0;
6549 	rack->r_ctl.rc_went_idle_time = 0;
6550 	tp->t_rxtshift = 0;
6551 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
6552 	   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
6553 	rack->r_ctl.rc_agg_delayed = 0;
6554 	rack->r_early = 0;
6555 	rack->r_late = 0;
6556 	rack->r_ctl.rc_agg_early = 0;
6557 }
6558 
6559 static void
6560 rack_log_hpts_diag(struct tcp_rack *rack, uint32_t cts,
6561 		   struct hpts_diag *diag, struct timeval *tv)
6562 {
6563 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
6564 		union tcp_log_stackspecific log;
6565 
6566 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
6567 		log.u_bbr.flex1 = diag->p_nxt_slot;
6568 		log.u_bbr.flex2 = diag->p_cur_slot;
6569 		log.u_bbr.flex3 = diag->slot_req;
6570 		log.u_bbr.flex4 = diag->inp_hptsslot;
6571 		log.u_bbr.flex5 = diag->slot_remaining;
6572 		log.u_bbr.flex6 = diag->need_new_to;
6573 		log.u_bbr.flex7 = diag->p_hpts_active;
6574 		log.u_bbr.flex8 = diag->p_on_min_sleep;
6575 		/* Hijack other fields as needed */
6576 		log.u_bbr.epoch = diag->have_slept;
6577 		log.u_bbr.lt_epoch = diag->yet_to_sleep;
6578 		log.u_bbr.pkts_out = diag->co_ret;
6579 		log.u_bbr.applimited = diag->hpts_sleep_time;
6580 		log.u_bbr.delivered = diag->p_prev_slot;
6581 		log.u_bbr.inflight = diag->p_runningslot;
6582 		log.u_bbr.bw_inuse = diag->wheel_slot;
6583 		log.u_bbr.rttProp = diag->wheel_cts;
6584 		log.u_bbr.timeStamp = cts;
6585 		log.u_bbr.delRate = diag->maxslots;
6586 		log.u_bbr.cur_del_rate = diag->p_curtick;
6587 		log.u_bbr.cur_del_rate <<= 32;
6588 		log.u_bbr.cur_del_rate |= diag->p_lasttick;
6589 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
6590 		    &rack->rc_inp->inp_socket->so_rcv,
6591 		    &rack->rc_inp->inp_socket->so_snd,
6592 		    BBR_LOG_HPTSDIAG, 0,
6593 		    0, &log, false, tv);
6594 	}
6595 
6596 }
6597 
6598 static void
6599 rack_log_wakeup(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb, uint32_t len, int type)
6600 {
6601 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
6602 		union tcp_log_stackspecific log;
6603 		struct timeval tv;
6604 
6605 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
6606 		log.u_bbr.flex1 = sb->sb_flags;
6607 		log.u_bbr.flex2 = len;
6608 		log.u_bbr.flex3 = sb->sb_state;
6609 		log.u_bbr.flex8 = type;
6610 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
6611 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
6612 		    &rack->rc_inp->inp_socket->so_rcv,
6613 		    &rack->rc_inp->inp_socket->so_snd,
6614 		    TCP_LOG_SB_WAKE, 0,
6615 		    len, &log, false, &tv);
6616 	}
6617 }
6618 
6619 static void
6620 rack_start_hpts_timer(struct tcp_rack *rack, struct tcpcb *tp, uint32_t cts,
6621       int32_t slot, uint32_t tot_len_this_send, int sup_rack)
6622 {
6623 	struct hpts_diag diag;
6624 	struct inpcb *inp = tptoinpcb(tp);
6625 	struct timeval tv;
6626 	uint32_t delayed_ack = 0;
6627 	uint32_t hpts_timeout;
6628 	uint32_t entry_slot = slot;
6629 	uint8_t stopped;
6630 	uint32_t left = 0;
6631 	uint32_t us_cts;
6632 
6633 	if ((tp->t_state == TCPS_CLOSED) ||
6634 	    (tp->t_state == TCPS_LISTEN)) {
6635 		return;
6636 	}
6637 	if (tcp_in_hpts(inp)) {
6638 		/* Already on the pacer */
6639 		return;
6640 	}
6641 	stopped = rack->rc_tmr_stopped;
6642 	if (stopped && TSTMP_GT(rack->r_ctl.rc_timer_exp, cts)) {
6643 		left = rack->r_ctl.rc_timer_exp - cts;
6644 	}
6645 	rack->r_ctl.rc_timer_exp = 0;
6646 	rack->r_ctl.rc_hpts_flags = 0;
6647 	us_cts = tcp_get_usecs(&tv);
6648 	/* Now early/late accounting */
6649 	rack_log_pacing_delay_calc(rack, entry_slot, slot, 0, 0, 0, 26, __LINE__, NULL, 0);
6650 	if (rack->r_early && (rack->rc_ack_can_sendout_data == 0)) {
6651 		/*
6652 		 * We have a early carry over set,
6653 		 * we can always add more time so we
6654 		 * can always make this compensation.
6655 		 *
6656 		 * Note if ack's are allowed to wake us do not
6657 		 * penalize the next timer for being awoke
6658 		 * by an ack aka the rc_agg_early (non-paced mode).
6659 		 */
6660 		slot += rack->r_ctl.rc_agg_early;
6661 		rack->r_early = 0;
6662 		rack->r_ctl.rc_agg_early = 0;
6663 	}
6664 	if (rack->r_late) {
6665 		/*
6666 		 * This is harder, we can
6667 		 * compensate some but it
6668 		 * really depends on what
6669 		 * the current pacing time is.
6670 		 */
6671 		if (rack->r_ctl.rc_agg_delayed >= slot) {
6672 			/*
6673 			 * We can't compensate for it all.
6674 			 * And we have to have some time
6675 			 * on the clock. We always have a min
6676 			 * 10 slots (10 x 10 i.e. 100 usecs).
6677 			 */
6678 			if (slot <= HPTS_TICKS_PER_SLOT) {
6679 				/* We gain delay */
6680 				rack->r_ctl.rc_agg_delayed += (HPTS_TICKS_PER_SLOT - slot);
6681 				slot = HPTS_TICKS_PER_SLOT;
6682 			} else {
6683 				/* We take off some */
6684 				rack->r_ctl.rc_agg_delayed -= (slot - HPTS_TICKS_PER_SLOT);
6685 				slot = HPTS_TICKS_PER_SLOT;
6686 			}
6687 		} else {
6688 			slot -= rack->r_ctl.rc_agg_delayed;
6689 			rack->r_ctl.rc_agg_delayed = 0;
6690 			/* Make sure we have 100 useconds at minimum */
6691 			if (slot < HPTS_TICKS_PER_SLOT) {
6692 				rack->r_ctl.rc_agg_delayed = HPTS_TICKS_PER_SLOT - slot;
6693 				slot = HPTS_TICKS_PER_SLOT;
6694 			}
6695 			if (rack->r_ctl.rc_agg_delayed == 0)
6696 				rack->r_late = 0;
6697 		}
6698 	}
6699 	hpts_timeout = rack_timer_start(tp, rack, cts, sup_rack);
6700 #ifdef TCP_SAD_DETECTION
6701 	if (rack->sack_attack_disable &&
6702 	    (rack->r_ctl.ack_during_sd > 0) &&
6703 	    (slot < tcp_sad_pacing_interval)) {
6704 		/*
6705 		 * We have a potential attacker on
6706 		 * the line. We have possibly some
6707 		 * (or now) pacing time set. We want to
6708 		 * slow down the processing of sacks by some
6709 		 * amount (if it is an attacker). Set the default
6710 		 * slot for attackers in place (unless the original
6711 		 * interval is longer). Its stored in
6712 		 * micro-seconds, so lets convert to msecs.
6713 		 */
6714 		slot = tcp_sad_pacing_interval;
6715 		rack_log_type_bbrsnd(rack, tot_len_this_send, slot, us_cts, &tv, __LINE__);
6716 		rack->r_ctl.ack_during_sd = 0;
6717 	}
6718 #endif
6719 	if (tp->t_flags & TF_DELACK) {
6720 		delayed_ack = TICKS_2_USEC(tcp_delacktime);
6721 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_DELACK;
6722 	}
6723 	if (delayed_ack && ((hpts_timeout == 0) ||
6724 			    (delayed_ack < hpts_timeout)))
6725 		hpts_timeout = delayed_ack;
6726 	else
6727 		rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
6728 	/*
6729 	 * If no timers are going to run and we will fall off the hptsi
6730 	 * wheel, we resort to a keep-alive timer if its configured.
6731 	 */
6732 	if ((hpts_timeout == 0) &&
6733 	    (slot == 0)) {
6734 		if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
6735 		    (tp->t_state <= TCPS_CLOSING)) {
6736 			/*
6737 			 * Ok we have no timer (persists, rack, tlp, rxt  or
6738 			 * del-ack), we don't have segments being paced. So
6739 			 * all that is left is the keepalive timer.
6740 			 */
6741 			if (TCPS_HAVEESTABLISHED(tp->t_state)) {
6742 				/* Get the established keep-alive time */
6743 				hpts_timeout = TICKS_2_USEC(TP_KEEPIDLE(tp));
6744 			} else {
6745 				/*
6746 				 * Get the initial setup keep-alive time,
6747 				 * note that this is probably not going to
6748 				 * happen, since rack will be running a rxt timer
6749 				 * if a SYN of some sort is outstanding. It is
6750 				 * actually handled in rack_timeout_rxt().
6751 				 */
6752 				hpts_timeout = TICKS_2_USEC(TP_KEEPINIT(tp));
6753 			}
6754 			rack->r_ctl.rc_hpts_flags |= PACE_TMR_KEEP;
6755 			if (rack->in_probe_rtt) {
6756 				/*
6757 				 * We want to instead not wake up a long time from
6758 				 * now but to wake up about the time we would
6759 				 * exit probe-rtt and initiate a keep-alive ack.
6760 				 * This will get us out of probe-rtt and update
6761 				 * our min-rtt.
6762 				 */
6763 				hpts_timeout = rack_min_probertt_hold;
6764 			}
6765 		}
6766 	}
6767 	if (left && (stopped & (PACE_TMR_KEEP | PACE_TMR_DELACK)) ==
6768 	    (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK)) {
6769 		/*
6770 		 * RACK, TLP, persists and RXT timers all are restartable
6771 		 * based on actions input .. i.e we received a packet (ack
6772 		 * or sack) and that changes things (rw, or snd_una etc).
6773 		 * Thus we can restart them with a new value. For
6774 		 * keep-alive, delayed_ack we keep track of what was left
6775 		 * and restart the timer with a smaller value.
6776 		 */
6777 		if (left < hpts_timeout)
6778 			hpts_timeout = left;
6779 	}
6780 	if (hpts_timeout) {
6781 		/*
6782 		 * Hack alert for now we can't time-out over 2,147,483
6783 		 * seconds (a bit more than 596 hours), which is probably ok
6784 		 * :).
6785 		 */
6786 		if (hpts_timeout > 0x7ffffffe)
6787 			hpts_timeout = 0x7ffffffe;
6788 		rack->r_ctl.rc_timer_exp = cts + hpts_timeout;
6789 	}
6790 	rack_log_pacing_delay_calc(rack, entry_slot, slot, hpts_timeout, 0, 0, 27, __LINE__, NULL, 0);
6791 	if ((rack->gp_ready == 0) &&
6792 	    (rack->use_fixed_rate == 0) &&
6793 	    (hpts_timeout < slot) &&
6794 	    (rack->r_ctl.rc_hpts_flags & (PACE_TMR_TLP|PACE_TMR_RXT))) {
6795 		/*
6796 		 * We have no good estimate yet for the
6797 		 * old clunky burst mitigation or the
6798 		 * real pacing. And the tlp or rxt is smaller
6799 		 * than the pacing calculation. Lets not
6800 		 * pace that long since we know the calculation
6801 		 * so far is not accurate.
6802 		 */
6803 		slot = hpts_timeout;
6804 	}
6805 	/**
6806 	 * Turn off all the flags for queuing by default. The
6807 	 * flags have important meanings to what happens when
6808 	 * LRO interacts with the transport. Most likely (by default now)
6809 	 * mbuf_queueing and ack compression are on. So the transport
6810 	 * has a couple of flags that control what happens (if those
6811 	 * are not on then these flags won't have any effect since it
6812 	 * won't go through the queuing LRO path).
6813 	 *
6814 	 * INP_MBUF_QUEUE_READY - This flags says that I am busy
6815 	 *                        pacing output, so don't disturb. But
6816 	 *                        it also means LRO can wake me if there
6817 	 *                        is a SACK arrival.
6818 	 *
6819 	 * INP_DONT_SACK_QUEUE - This flag is used in conjunction
6820 	 *                       with the above flag (QUEUE_READY) and
6821 	 *                       when present it says don't even wake me
6822 	 *                       if a SACK arrives.
6823 	 *
6824 	 * The idea behind these flags is that if we are pacing we
6825 	 * set the MBUF_QUEUE_READY and only get woken up if
6826 	 * a SACK arrives (which could change things) or if
6827 	 * our pacing timer expires. If, however, we have a rack
6828 	 * timer running, then we don't even want a sack to wake
6829 	 * us since the rack timer has to expire before we can send.
6830 	 *
6831 	 * Other cases should usually have none of the flags set
6832 	 * so LRO can call into us.
6833 	 */
6834 	inp->inp_flags2 &= ~(INP_DONT_SACK_QUEUE|INP_MBUF_QUEUE_READY);
6835 	if (slot) {
6836 		rack->r_ctl.rc_hpts_flags |= PACE_PKT_OUTPUT;
6837 		rack->r_ctl.rc_last_output_to = us_cts + slot;
6838 		/*
6839 		 * A pacing timer (slot) is being set, in
6840 		 * such a case we cannot send (we are blocked by
6841 		 * the timer). So lets tell LRO that it should not
6842 		 * wake us unless there is a SACK. Note this only
6843 		 * will be effective if mbuf queueing is on or
6844 		 * compressed acks are being processed.
6845 		 */
6846 		inp->inp_flags2 |= INP_MBUF_QUEUE_READY;
6847 		/*
6848 		 * But wait if we have a Rack timer running
6849 		 * even a SACK should not disturb us (with
6850 		 * the exception of r_rr_config 3).
6851 		 */
6852 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK) {
6853 			if (rack->r_rr_config != 3)
6854 				inp->inp_flags2 |= INP_DONT_SACK_QUEUE;
6855 			else if (rack->rc_pace_dnd) {
6856 				if (IN_RECOVERY(tp->t_flags)) {
6857 					/*
6858 					 * When DND is on, we only let a sack
6859 					 * interrupt us if we are not in recovery.
6860 					 *
6861 					 * If DND is off, then we never hit here
6862 					 * and let all sacks wake us up.
6863 					 *
6864 					 */
6865 					inp->inp_flags2 |= INP_DONT_SACK_QUEUE;
6866 				}
6867 			}
6868 		}
6869 		/* For sack attackers we want to ignore sack */
6870 		if (rack->sack_attack_disable == 1) {
6871 			inp->inp_flags2 |= (INP_DONT_SACK_QUEUE|INP_MBUF_QUEUE_READY);
6872 		} else if (rack->rc_ack_can_sendout_data) {
6873 			/*
6874 			 * Ahh but wait, this is that special case
6875 			 * where the pacing timer can be disturbed
6876 			 * backout the changes (used for non-paced
6877 			 * burst limiting).
6878 			 */
6879 			inp->inp_flags2 &= ~(INP_DONT_SACK_QUEUE|INP_MBUF_QUEUE_READY);
6880 		}
6881 		if ((rack->use_rack_rr) &&
6882 		    (rack->r_rr_config < 2) &&
6883 		    ((hpts_timeout) && (hpts_timeout < slot))) {
6884 			/*
6885 			 * Arrange for the hpts to kick back in after the
6886 			 * t-o if the t-o does not cause a send.
6887 			 */
6888 			(void)tcp_hpts_insert_diag(inp, HPTS_USEC_TO_SLOTS(hpts_timeout),
6889 						   __LINE__, &diag);
6890 			rack_log_hpts_diag(rack, us_cts, &diag, &tv);
6891 			rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
6892 		} else {
6893 			(void)tcp_hpts_insert_diag(inp, HPTS_USEC_TO_SLOTS(slot),
6894 						   __LINE__, &diag);
6895 			rack_log_hpts_diag(rack, us_cts, &diag, &tv);
6896 			rack_log_to_start(rack, cts, hpts_timeout, slot, 1);
6897 		}
6898 	} else if (hpts_timeout) {
6899 		/*
6900 		 * With respect to inp_flags2 here, lets let any new acks wake
6901 		 * us up here. Since we are not pacing (no pacing timer), output
6902 		 * can happen so we should let it. If its a Rack timer, then any inbound
6903 		 * packet probably won't change the sending (we will be blocked)
6904 		 * but it may change the prr stats so letting it in (the set defaults
6905 		 * at the start of this block) are good enough.
6906 		 */
6907 		rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
6908 		(void)tcp_hpts_insert_diag(inp, HPTS_USEC_TO_SLOTS(hpts_timeout),
6909 					   __LINE__, &diag);
6910 		rack_log_hpts_diag(rack, us_cts, &diag, &tv);
6911 		rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
6912 	} else {
6913 		/* No timer starting */
6914 #ifdef INVARIANTS
6915 		if (SEQ_GT(tp->snd_max, tp->snd_una)) {
6916 			panic("tp:%p rack:%p tlts:%d cts:%u slot:%u pto:%u -- no timer started?",
6917 			    tp, rack, tot_len_this_send, cts, slot, hpts_timeout);
6918 		}
6919 #endif
6920 	}
6921 	rack->rc_tmr_stopped = 0;
6922 	if (slot)
6923 		rack_log_type_bbrsnd(rack, tot_len_this_send, slot, us_cts, &tv, __LINE__);
6924 }
6925 
6926 /*
6927  * RACK Timer, here we simply do logging and house keeping.
6928  * the normal rack_output() function will call the
6929  * appropriate thing to check if we need to do a RACK retransmit.
6930  * We return 1, saying don't proceed with rack_output only
6931  * when all timers have been stopped (destroyed PCB?).
6932  */
6933 static int
6934 rack_timeout_rack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6935 {
6936 	/*
6937 	 * This timer simply provides an internal trigger to send out data.
6938 	 * The check_recovery_mode call will see if there are needed
6939 	 * retransmissions, if so we will enter fast-recovery. The output
6940 	 * call may or may not do the same thing depending on sysctl
6941 	 * settings.
6942 	 */
6943 	struct rack_sendmap *rsm;
6944 
6945 	counter_u64_add(rack_to_tot, 1);
6946 	if (rack->r_state && (rack->r_state != tp->t_state))
6947 		rack_set_state(tp, rack);
6948 	rack->rc_on_min_to = 0;
6949 	rsm = rack_check_recovery_mode(tp, cts);
6950 	rack_log_to_event(rack, RACK_TO_FRM_RACK, rsm);
6951 	if (rsm) {
6952 		rack->r_ctl.rc_resend = rsm;
6953 		rack->r_timer_override = 1;
6954 		if (rack->use_rack_rr) {
6955 			/*
6956 			 * Don't accumulate extra pacing delay
6957 			 * we are allowing the rack timer to
6958 			 * over-ride pacing i.e. rrr takes precedence
6959 			 * if the pacing interval is longer than the rrr
6960 			 * time (in other words we get the min pacing
6961 			 * time versus rrr pacing time).
6962 			 */
6963 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
6964 		}
6965 	}
6966 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RACK;
6967 	if (rsm == NULL) {
6968 		/* restart a timer and return 1 */
6969 		rack_start_hpts_timer(rack, tp, cts,
6970 				      0, 0, 0);
6971 		return (1);
6972 	}
6973 	return (0);
6974 }
6975 
6976 
6977 
6978 static void
6979 rack_adjust_orig_mlen(struct rack_sendmap *rsm)
6980 {
6981 
6982 	if ((M_TRAILINGROOM(rsm->m) != rsm->orig_t_space)) {
6983 		/*
6984 		 * The trailing space changed, mbufs can grow
6985 		 * at the tail but they can't shrink from
6986 		 * it, KASSERT that. Adjust the orig_m_len to
6987 		 * compensate for this change.
6988 		 */
6989 		KASSERT((rsm->orig_t_space > M_TRAILINGROOM(rsm->m)),
6990 			("mbuf:%p rsm:%p trailing_space:%jd ots:%u oml:%u mlen:%u\n",
6991 			 rsm->m,
6992 			 rsm,
6993 			 (intmax_t)M_TRAILINGROOM(rsm->m),
6994 			 rsm->orig_t_space,
6995 			 rsm->orig_m_len,
6996 			 rsm->m->m_len));
6997 		rsm->orig_m_len += (rsm->orig_t_space - M_TRAILINGROOM(rsm->m));
6998 		rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
6999 	}
7000 	if (rsm->m->m_len < rsm->orig_m_len) {
7001 		/*
7002 		 * Mbuf shrank, trimmed off the top by an ack, our
7003 		 * offset changes.
7004 		 */
7005 		KASSERT((rsm->soff >= (rsm->orig_m_len - rsm->m->m_len)),
7006 			("mbuf:%p len:%u rsm:%p oml:%u soff:%u\n",
7007 			 rsm->m, rsm->m->m_len,
7008 			 rsm, rsm->orig_m_len,
7009 			 rsm->soff));
7010 		if (rsm->soff >= (rsm->orig_m_len - rsm->m->m_len))
7011 			rsm->soff -= (rsm->orig_m_len - rsm->m->m_len);
7012 		else
7013 			rsm->soff = 0;
7014 		rsm->orig_m_len = rsm->m->m_len;
7015 #ifdef INVARIANTS
7016 	} else if (rsm->m->m_len > rsm->orig_m_len) {
7017 		panic("rsm:%p m:%p m_len grew outside of t_space compensation",
7018 		      rsm, rsm->m);
7019 #endif
7020 	}
7021 }
7022 
7023 static void
7024 rack_setup_offset_for_rsm(struct tcp_rack *rack, struct rack_sendmap *src_rsm, struct rack_sendmap *rsm)
7025 {
7026 	struct mbuf *m;
7027 	uint32_t soff;
7028 
7029 	if (src_rsm->m &&
7030 	    ((src_rsm->orig_m_len != src_rsm->m->m_len) ||
7031 	     (M_TRAILINGROOM(src_rsm->m) != src_rsm->orig_t_space))) {
7032 		/* Fix up the orig_m_len and possibly the mbuf offset */
7033 		rack_adjust_orig_mlen(src_rsm);
7034 	}
7035 	m = src_rsm->m;
7036 	soff = src_rsm->soff + (src_rsm->r_end - src_rsm->r_start);
7037 	while (soff >= m->m_len) {
7038 		/* Move out past this mbuf */
7039 		soff -= m->m_len;
7040 		m = m->m_next;
7041 		KASSERT((m != NULL),
7042 			("rsm:%p nrsm:%p hit at soff:%u null m",
7043 			 src_rsm, rsm, soff));
7044 		if (m == NULL) {
7045 			/* This should *not* happen which is why there is a kassert */
7046 			src_rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd,
7047 					       (src_rsm->r_start - rack->rc_tp->snd_una),
7048 					       &src_rsm->soff);
7049 			src_rsm->orig_m_len = src_rsm->m->m_len;
7050 			src_rsm->orig_t_space = M_TRAILINGROOM(src_rsm->m);
7051 			rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd,
7052 					   (rsm->r_start - rack->rc_tp->snd_una),
7053 					   &rsm->soff);
7054 			rsm->orig_m_len = rsm->m->m_len;
7055 			rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
7056 			return;
7057 		}
7058 	}
7059 	rsm->m = m;
7060 	rsm->soff = soff;
7061 	rsm->orig_m_len = m->m_len;
7062 	rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
7063 }
7064 
7065 static __inline void
7066 rack_clone_rsm(struct tcp_rack *rack, struct rack_sendmap *nrsm,
7067 	       struct rack_sendmap *rsm, uint32_t start)
7068 {
7069 	int idx;
7070 
7071 	nrsm->r_start = start;
7072 	nrsm->r_end = rsm->r_end;
7073 	nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
7074 	nrsm->r_flags = rsm->r_flags;
7075 	nrsm->r_dupack = rsm->r_dupack;
7076 	nrsm->r_no_rtt_allowed = rsm->r_no_rtt_allowed;
7077 	nrsm->r_rtr_bytes = 0;
7078 	nrsm->r_fas = rsm->r_fas;
7079 	nrsm->r_bas = rsm->r_bas;
7080 	rsm->r_end = nrsm->r_start;
7081 	nrsm->r_just_ret = rsm->r_just_ret;
7082 	for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
7083 		nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
7084 	}
7085 	/* Now if we have SYN flag we keep it on the left edge */
7086 	if (nrsm->r_flags & RACK_HAS_SYN)
7087 		nrsm->r_flags &= ~RACK_HAS_SYN;
7088 	/* Now if we have a FIN flag we keep it on the right edge */
7089 	if (rsm->r_flags & RACK_HAS_FIN)
7090 		rsm->r_flags &= ~RACK_HAS_FIN;
7091 	/* Push bit must go to the right edge as well */
7092 	if (rsm->r_flags & RACK_HAD_PUSH)
7093 		rsm->r_flags &= ~RACK_HAD_PUSH;
7094 	/* Clone over the state of the hw_tls flag */
7095 	nrsm->r_hw_tls = rsm->r_hw_tls;
7096 	/*
7097 	 * Now we need to find nrsm's new location in the mbuf chain
7098 	 * we basically calculate a new offset, which is soff +
7099 	 * how much is left in original rsm. Then we walk out the mbuf
7100 	 * chain to find the righ position, it may be the same mbuf
7101 	 * or maybe not.
7102 	 */
7103 	KASSERT(((rsm->m != NULL) ||
7104 		 (rsm->r_flags & (RACK_HAS_SYN|RACK_HAS_FIN))),
7105 		("rsm:%p nrsm:%p rack:%p -- rsm->m is NULL?", rsm, nrsm, rack));
7106 	if (rsm->m)
7107 		rack_setup_offset_for_rsm(rack, rsm, nrsm);
7108 }
7109 
7110 static struct rack_sendmap *
7111 rack_merge_rsm(struct tcp_rack *rack,
7112 	       struct rack_sendmap *l_rsm,
7113 	       struct rack_sendmap *r_rsm)
7114 {
7115 	/*
7116 	 * We are merging two ack'd RSM's,
7117 	 * the l_rsm is on the left (lower seq
7118 	 * values) and the r_rsm is on the right
7119 	 * (higher seq value). The simplest way
7120 	 * to merge these is to move the right
7121 	 * one into the left. I don't think there
7122 	 * is any reason we need to try to find
7123 	 * the oldest (or last oldest retransmitted).
7124 	 */
7125 	rack_log_map_chg(rack->rc_tp, rack, NULL,
7126 			 l_rsm, r_rsm, MAP_MERGE, r_rsm->r_end, __LINE__);
7127 	l_rsm->r_end = r_rsm->r_end;
7128 	if (l_rsm->r_dupack < r_rsm->r_dupack)
7129 		l_rsm->r_dupack = r_rsm->r_dupack;
7130 	if (r_rsm->r_rtr_bytes)
7131 		l_rsm->r_rtr_bytes += r_rsm->r_rtr_bytes;
7132 	if (r_rsm->r_in_tmap) {
7133 		/* This really should not happen */
7134 		TAILQ_REMOVE(&rack->r_ctl.rc_tmap, r_rsm, r_tnext);
7135 		r_rsm->r_in_tmap = 0;
7136 	}
7137 
7138 	/* Now the flags */
7139 	if (r_rsm->r_flags & RACK_HAS_FIN)
7140 		l_rsm->r_flags |= RACK_HAS_FIN;
7141 	if (r_rsm->r_flags & RACK_TLP)
7142 		l_rsm->r_flags |= RACK_TLP;
7143 	if (r_rsm->r_flags & RACK_RWND_COLLAPSED)
7144 		l_rsm->r_flags |= RACK_RWND_COLLAPSED;
7145 	if ((r_rsm->r_flags & RACK_APP_LIMITED)  &&
7146 	    ((l_rsm->r_flags & RACK_APP_LIMITED) == 0)) {
7147 		/*
7148 		 * If both are app-limited then let the
7149 		 * free lower the count. If right is app
7150 		 * limited and left is not, transfer.
7151 		 */
7152 		l_rsm->r_flags |= RACK_APP_LIMITED;
7153 		r_rsm->r_flags &= ~RACK_APP_LIMITED;
7154 		if (r_rsm == rack->r_ctl.rc_first_appl)
7155 			rack->r_ctl.rc_first_appl = l_rsm;
7156 	}
7157 	tqhash_remove(rack->r_ctl.tqh, r_rsm, REMOVE_TYPE_MERGE);
7158 	/*
7159 	 * We keep the largest value, which is the newest
7160 	 * send. We do this in case a segment that is
7161 	 * joined together and not part of a GP estimate
7162 	 * later gets expanded into the GP estimate.
7163 	 *
7164 	 * We prohibit the merging of unlike kinds i.e.
7165 	 * all pieces that are in the GP estimate can be
7166 	 * merged and all pieces that are not in a GP estimate
7167 	 * can be merged, but not disimilar pieces. Combine
7168 	 * this with taking the highest here and we should
7169 	 * be ok unless of course the client reneges. Then
7170 	 * all bets are off.
7171 	 */
7172 	if(l_rsm->r_tim_lastsent[(l_rsm->r_rtr_cnt-1)] <
7173 	   r_rsm->r_tim_lastsent[(r_rsm->r_rtr_cnt-1)]) {
7174 		l_rsm->r_tim_lastsent[(l_rsm->r_rtr_cnt-1)] = r_rsm->r_tim_lastsent[(r_rsm->r_rtr_cnt-1)];
7175 	}
7176 	/*
7177 	 * When merging two RSM's we also need to consider the ack time and keep
7178 	 * newest. If the ack gets merged into a measurement then that is the
7179 	 * one we will want to be using.
7180 	 */
7181 	if(l_rsm->r_ack_arrival	 < r_rsm->r_ack_arrival)
7182 		l_rsm->r_ack_arrival = r_rsm->r_ack_arrival;
7183 
7184 	if ((r_rsm->r_limit_type == 0) && (l_rsm->r_limit_type != 0)) {
7185 		/* Transfer the split limit to the map we free */
7186 		r_rsm->r_limit_type = l_rsm->r_limit_type;
7187 		l_rsm->r_limit_type = 0;
7188 	}
7189 	rack_free(rack, r_rsm);
7190 	l_rsm->r_flags |= RACK_MERGED;
7191 	return (l_rsm);
7192 }
7193 
7194 /*
7195  * TLP Timer, here we simply setup what segment we want to
7196  * have the TLP expire on, the normal rack_output() will then
7197  * send it out.
7198  *
7199  * We return 1, saying don't proceed with rack_output only
7200  * when all timers have been stopped (destroyed PCB?).
7201  */
7202 static int
7203 rack_timeout_tlp(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t *doing_tlp)
7204 {
7205 	/*
7206 	 * Tail Loss Probe.
7207 	 */
7208 	struct rack_sendmap *rsm = NULL;
7209 	int insret __diagused;
7210 	struct socket *so = tptosocket(tp);
7211 	uint32_t amm;
7212 	uint32_t out, avail;
7213 	int collapsed_win = 0;
7214 
7215 	if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
7216 		/* Its not time yet */
7217 		return (0);
7218 	}
7219 	if (ctf_progress_timeout_check(tp, true)) {
7220 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
7221 		return (-ETIMEDOUT);	/* tcp_drop() */
7222 	}
7223 	/*
7224 	 * A TLP timer has expired. We have been idle for 2 rtts. So we now
7225 	 * need to figure out how to force a full MSS segment out.
7226 	 */
7227 	rack_log_to_event(rack, RACK_TO_FRM_TLP, NULL);
7228 	rack->r_ctl.retran_during_recovery = 0;
7229 	rack->r_ctl.dsack_byte_cnt = 0;
7230 	counter_u64_add(rack_tlp_tot, 1);
7231 	if (rack->r_state && (rack->r_state != tp->t_state))
7232 		rack_set_state(tp, rack);
7233 	avail = sbavail(&so->so_snd);
7234 	out = tp->snd_max - tp->snd_una;
7235 	if ((out > tp->snd_wnd) || rack->rc_has_collapsed) {
7236 		/* special case, we need a retransmission */
7237 		collapsed_win = 1;
7238 		goto need_retran;
7239 	}
7240 	if (rack->r_ctl.dsack_persist && (rack->r_ctl.rc_tlp_cnt_out >= 1)) {
7241 		rack->r_ctl.dsack_persist--;
7242 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
7243 			rack->r_ctl.num_dsack = 0;
7244 		}
7245 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
7246 	}
7247 	if ((tp->t_flags & TF_GPUTINPROG) &&
7248 	    (rack->r_ctl.rc_tlp_cnt_out == 1)) {
7249 		/*
7250 		 * If this is the second in a row
7251 		 * TLP and we are doing a measurement
7252 		 * its time to abandon the measurement.
7253 		 * Something is likely broken on
7254 		 * the clients network and measuring a
7255 		 * broken network does us no good.
7256 		 */
7257 		tp->t_flags &= ~TF_GPUTINPROG;
7258 		rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
7259 					   rack->r_ctl.rc_gp_srtt /*flex1*/,
7260 					   tp->gput_seq,
7261 					   0, 0, 18, __LINE__, NULL, 0);
7262 	}
7263 	/*
7264 	 * Check our send oldest always settings, and if
7265 	 * there is an oldest to send jump to the need_retran.
7266 	 */
7267 	if (rack_always_send_oldest && (TAILQ_EMPTY(&rack->r_ctl.rc_tmap) == 0))
7268 		goto need_retran;
7269 
7270 	if (avail > out) {
7271 		/* New data is available */
7272 		amm = avail - out;
7273 		if (amm > ctf_fixed_maxseg(tp)) {
7274 			amm = ctf_fixed_maxseg(tp);
7275 			if ((amm + out) > tp->snd_wnd) {
7276 				/* We are rwnd limited */
7277 				goto need_retran;
7278 			}
7279 		} else if (amm < ctf_fixed_maxseg(tp)) {
7280 			/* not enough to fill a MTU */
7281 			goto need_retran;
7282 		}
7283 		if (IN_FASTRECOVERY(tp->t_flags)) {
7284 			/* Unlikely */
7285 			if (rack->rack_no_prr == 0) {
7286 				if (out + amm <= tp->snd_wnd) {
7287 					rack->r_ctl.rc_prr_sndcnt = amm;
7288 					rack->r_ctl.rc_tlp_new_data = amm;
7289 					rack_log_to_prr(rack, 4, 0, __LINE__);
7290 				}
7291 			} else
7292 				goto need_retran;
7293 		} else {
7294 			/* Set the send-new override */
7295 			if (out + amm <= tp->snd_wnd)
7296 				rack->r_ctl.rc_tlp_new_data = amm;
7297 			else
7298 				goto need_retran;
7299 		}
7300 		rack->r_ctl.rc_tlpsend = NULL;
7301 		counter_u64_add(rack_tlp_newdata, 1);
7302 		goto send;
7303 	}
7304 need_retran:
7305 	/*
7306 	 * Ok we need to arrange the last un-acked segment to be re-sent, or
7307 	 * optionally the first un-acked segment.
7308 	 */
7309 	if (collapsed_win == 0) {
7310 		if (rack_always_send_oldest)
7311 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
7312 		else {
7313 			rsm = tqhash_max(rack->r_ctl.tqh);
7314 			if (rsm && (rsm->r_flags & (RACK_ACKED | RACK_HAS_FIN))) {
7315 				rsm = rack_find_high_nonack(rack, rsm);
7316 			}
7317 		}
7318 		if (rsm == NULL) {
7319 #ifdef TCP_BLACKBOX
7320 			tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
7321 #endif
7322 			goto out;
7323 		}
7324 	} else {
7325 		/*
7326 		 * We had a collapsed window, lets find
7327 		 * the point before the collapse.
7328 		 */
7329 		if (SEQ_GT((rack->r_ctl.last_collapse_point - 1), rack->rc_tp->snd_una))
7330 			rsm = tqhash_find(rack->r_ctl.tqh, (rack->r_ctl.last_collapse_point - 1));
7331 		else {
7332 			rsm = tqhash_min(rack->r_ctl.tqh);
7333 		}
7334 		if (rsm == NULL) {
7335 			/* Huh */
7336 			goto out;
7337 		}
7338 	}
7339 	if ((rsm->r_end - rsm->r_start) > ctf_fixed_maxseg(tp)) {
7340 		/*
7341 		 * We need to split this the last segment in two.
7342 		 */
7343 		struct rack_sendmap *nrsm;
7344 
7345 		nrsm = rack_alloc_full_limit(rack);
7346 		if (nrsm == NULL) {
7347 			/*
7348 			 * No memory to split, we will just exit and punt
7349 			 * off to the RXT timer.
7350 			 */
7351 			goto out;
7352 		}
7353 		rack_clone_rsm(rack, nrsm, rsm,
7354 			       (rsm->r_end - ctf_fixed_maxseg(tp)));
7355 		rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
7356 #ifndef INVARIANTS
7357 		(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
7358 #else
7359 		if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
7360 			panic("Insert in rb tree of %p fails ret:%d rack:%p rsm:%p",
7361 			      nrsm, insret, rack, rsm);
7362 		}
7363 #endif
7364 		if (rsm->r_in_tmap) {
7365 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7366 			nrsm->r_in_tmap = 1;
7367 		}
7368 		rsm = nrsm;
7369 	}
7370 	rack->r_ctl.rc_tlpsend = rsm;
7371 send:
7372 	/* Make sure output path knows we are doing a TLP */
7373 	*doing_tlp = 1;
7374 	rack->r_timer_override = 1;
7375 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
7376 	return (0);
7377 out:
7378 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
7379 	return (0);
7380 }
7381 
7382 /*
7383  * Delayed ack Timer, here we simply need to setup the
7384  * ACK_NOW flag and remove the DELACK flag. From there
7385  * the output routine will send the ack out.
7386  *
7387  * We only return 1, saying don't proceed, if all timers
7388  * are stopped (destroyed PCB?).
7389  */
7390 static int
7391 rack_timeout_delack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
7392 {
7393 
7394 	rack_log_to_event(rack, RACK_TO_FRM_DELACK, NULL);
7395 	tp->t_flags &= ~TF_DELACK;
7396 	tp->t_flags |= TF_ACKNOW;
7397 	KMOD_TCPSTAT_INC(tcps_delack);
7398 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
7399 	return (0);
7400 }
7401 
7402 /*
7403  * Persists timer, here we simply send the
7404  * same thing as a keepalive will.
7405  * the one byte send.
7406  *
7407  * We only return 1, saying don't proceed, if all timers
7408  * are stopped (destroyed PCB?).
7409  */
7410 static int
7411 rack_timeout_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
7412 {
7413 	struct tcptemp *t_template;
7414 	int32_t retval = 1;
7415 
7416 	if (rack->rc_in_persist == 0)
7417 		return (0);
7418 	if (ctf_progress_timeout_check(tp, false)) {
7419 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
7420 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
7421 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
7422 		return (-ETIMEDOUT);	/* tcp_drop() */
7423 	}
7424 	/*
7425 	 * Persistence timer into zero window. Force a byte to be output, if
7426 	 * possible.
7427 	 */
7428 	KMOD_TCPSTAT_INC(tcps_persisttimeo);
7429 	/*
7430 	 * Hack: if the peer is dead/unreachable, we do not time out if the
7431 	 * window is closed.  After a full backoff, drop the connection if
7432 	 * the idle time (no responses to probes) reaches the maximum
7433 	 * backoff that we would use if retransmitting.
7434 	 */
7435 	if (tp->t_rxtshift == TCP_MAXRXTSHIFT &&
7436 	    (ticks - tp->t_rcvtime >= tcp_maxpersistidle ||
7437 	     TICKS_2_USEC(ticks - tp->t_rcvtime) >= RACK_REXMTVAL(tp) * tcp_totbackoff)) {
7438 		KMOD_TCPSTAT_INC(tcps_persistdrop);
7439 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
7440 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
7441 		retval = -ETIMEDOUT;	/* tcp_drop() */
7442 		goto out;
7443 	}
7444 	if ((sbavail(&rack->rc_inp->inp_socket->so_snd) == 0) &&
7445 	    tp->snd_una == tp->snd_max)
7446 		rack_exit_persist(tp, rack, cts);
7447 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_PERSIT;
7448 	/*
7449 	 * If the user has closed the socket then drop a persisting
7450 	 * connection after a much reduced timeout.
7451 	 */
7452 	if (tp->t_state > TCPS_CLOSE_WAIT &&
7453 	    (ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) {
7454 		KMOD_TCPSTAT_INC(tcps_persistdrop);
7455 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
7456 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
7457 		retval = -ETIMEDOUT;	/* tcp_drop() */
7458 		goto out;
7459 	}
7460 	t_template = tcpip_maketemplate(rack->rc_inp);
7461 	if (t_template) {
7462 		/* only set it if we were answered */
7463 		if (rack->forced_ack == 0) {
7464 			rack->forced_ack = 1;
7465 			rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
7466 		} else {
7467 			rack->probe_not_answered = 1;
7468 			counter_u64_add(rack_persists_loss, 1);
7469 			rack->r_ctl.persist_lost_ends++;
7470 		}
7471 		counter_u64_add(rack_persists_sends, 1);
7472 		counter_u64_add(rack_out_size[TCP_MSS_ACCT_PERSIST], 1);
7473 		tcp_respond(tp, t_template->tt_ipgen,
7474 			    &t_template->tt_t, (struct mbuf *)NULL,
7475 			    tp->rcv_nxt, tp->snd_una - 1, 0);
7476 		/* This sends an ack */
7477 		if (tp->t_flags & TF_DELACK)
7478 			tp->t_flags &= ~TF_DELACK;
7479 		free(t_template, M_TEMP);
7480 	}
7481 	if (tp->t_rxtshift < TCP_MAXRXTSHIFT)
7482 		tp->t_rxtshift++;
7483 out:
7484 	rack_log_to_event(rack, RACK_TO_FRM_PERSIST, NULL);
7485 	rack_start_hpts_timer(rack, tp, cts,
7486 			      0, 0, 0);
7487 	return (retval);
7488 }
7489 
7490 /*
7491  * If a keepalive goes off, we had no other timers
7492  * happening. We always return 1 here since this
7493  * routine either drops the connection or sends
7494  * out a segment with respond.
7495  */
7496 static int
7497 rack_timeout_keepalive(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
7498 {
7499 	struct tcptemp *t_template;
7500 	struct inpcb *inp = tptoinpcb(tp);
7501 
7502 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_KEEP;
7503 	rack_log_to_event(rack, RACK_TO_FRM_KEEP, NULL);
7504 	/*
7505 	 * Keep-alive timer went off; send something or drop connection if
7506 	 * idle for too long.
7507 	 */
7508 	KMOD_TCPSTAT_INC(tcps_keeptimeo);
7509 	if (tp->t_state < TCPS_ESTABLISHED)
7510 		goto dropit;
7511 	if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
7512 	    tp->t_state <= TCPS_CLOSING) {
7513 		if (ticks - tp->t_rcvtime >= TP_KEEPIDLE(tp) + TP_MAXIDLE(tp))
7514 			goto dropit;
7515 		/*
7516 		 * Send a packet designed to force a response if the peer is
7517 		 * up and reachable: either an ACK if the connection is
7518 		 * still alive, or an RST if the peer has closed the
7519 		 * connection due to timeout or reboot. Using sequence
7520 		 * number tp->snd_una-1 causes the transmitted zero-length
7521 		 * segment to lie outside the receive window; by the
7522 		 * protocol spec, this requires the correspondent TCP to
7523 		 * respond.
7524 		 */
7525 		KMOD_TCPSTAT_INC(tcps_keepprobe);
7526 		t_template = tcpip_maketemplate(inp);
7527 		if (t_template) {
7528 			if (rack->forced_ack == 0) {
7529 				rack->forced_ack = 1;
7530 				rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
7531 			} else {
7532 				rack->probe_not_answered = 1;
7533 			}
7534 			tcp_respond(tp, t_template->tt_ipgen,
7535 			    &t_template->tt_t, (struct mbuf *)NULL,
7536 			    tp->rcv_nxt, tp->snd_una - 1, 0);
7537 			free(t_template, M_TEMP);
7538 		}
7539 	}
7540 	rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
7541 	return (1);
7542 dropit:
7543 	KMOD_TCPSTAT_INC(tcps_keepdrops);
7544 	tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
7545 	return (-ETIMEDOUT);	/* tcp_drop() */
7546 }
7547 
7548 /*
7549  * Retransmit helper function, clear up all the ack
7550  * flags and take care of important book keeping.
7551  */
7552 static void
7553 rack_remxt_tmr(struct tcpcb *tp)
7554 {
7555 	/*
7556 	 * The retransmit timer went off, all sack'd blocks must be
7557 	 * un-acked.
7558 	 */
7559 	struct rack_sendmap *rsm, *trsm = NULL;
7560 	struct tcp_rack *rack;
7561 
7562 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7563 	rack_timer_cancel(tp, rack, tcp_get_usecs(NULL), __LINE__);
7564 	rack_log_to_event(rack, RACK_TO_FRM_TMR, NULL);
7565 	if (rack->r_state && (rack->r_state != tp->t_state))
7566 		rack_set_state(tp, rack);
7567 	/*
7568 	 * Ideally we would like to be able to
7569 	 * mark SACK-PASS on anything not acked here.
7570 	 *
7571 	 * However, if we do that we would burst out
7572 	 * all that data 1ms apart. This would be unwise,
7573 	 * so for now we will just let the normal rxt timer
7574 	 * and tlp timer take care of it.
7575 	 *
7576 	 * Also we really need to stick them back in sequence
7577 	 * order. This way we send in the proper order and any
7578 	 * sacks that come floating in will "re-ack" the data.
7579 	 * To do this we zap the tmap with an INIT and then
7580 	 * walk through and place every rsm in the RB tree
7581 	 * back in its seq ordered place.
7582 	 */
7583 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
7584 
7585 	TQHASH_FOREACH(rsm, rack->r_ctl.tqh)  {
7586 		rsm->r_dupack = 0;
7587 		if (rack_verbose_logging)
7588 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
7589 		/* We must re-add it back to the tlist */
7590 		if (trsm == NULL) {
7591 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7592 		} else {
7593 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, trsm, rsm, r_tnext);
7594 		}
7595 		rsm->r_in_tmap = 1;
7596 		trsm = rsm;
7597 		if (rsm->r_flags & RACK_ACKED)
7598 			rsm->r_flags |= RACK_WAS_ACKED;
7599 		rsm->r_flags &= ~(RACK_ACKED | RACK_SACK_PASSED | RACK_WAS_SACKPASS | RACK_RWND_COLLAPSED);
7600 		rsm->r_flags |= RACK_MUST_RXT;
7601 	}
7602 	/* Clear the count (we just un-acked them) */
7603 	rack->r_ctl.rc_last_timeout_snduna = tp->snd_una;
7604 	rack->r_ctl.rc_sacked = 0;
7605 	rack->r_ctl.rc_sacklast = NULL;
7606 	rack->r_ctl.rc_agg_delayed = 0;
7607 	rack->r_early = 0;
7608 	rack->r_ctl.rc_agg_early = 0;
7609 	rack->r_late = 0;
7610 	/* Clear the tlp rtx mark */
7611 	rack->r_ctl.rc_resend = tqhash_min(rack->r_ctl.tqh);
7612 	if (rack->r_ctl.rc_resend != NULL)
7613 		rack->r_ctl.rc_resend->r_flags |= RACK_TO_REXT;
7614 	rack->r_ctl.rc_prr_sndcnt = 0;
7615 	rack_log_to_prr(rack, 6, 0, __LINE__);
7616 	rack->r_timer_override = 1;
7617 	if ((((tp->t_flags & TF_SACK_PERMIT) == 0)
7618 #ifdef TCP_SAD_DETECTION
7619 	    || (rack->sack_attack_disable != 0)
7620 #endif
7621 		    ) && ((tp->t_flags & TF_SENTFIN) == 0)) {
7622 		/*
7623 		 * For non-sack customers new data
7624 		 * needs to go out as retransmits until
7625 		 * we retransmit up to snd_max.
7626 		 */
7627 		rack->r_must_retran = 1;
7628 		rack->r_ctl.rc_out_at_rto = ctf_flight_size(rack->rc_tp,
7629 						rack->r_ctl.rc_sacked);
7630 	}
7631 	rack->r_ctl.rc_snd_max_at_rto = tp->snd_max;
7632 }
7633 
7634 static void
7635 rack_convert_rtts(struct tcpcb *tp)
7636 {
7637 	tcp_change_time_units(tp, TCP_TMR_GRANULARITY_USEC);
7638 	tp->t_rxtcur = RACK_REXMTVAL(tp);
7639 	if (TCPS_HAVEESTABLISHED(tp->t_state)) {
7640 		tp->t_rxtcur += TICKS_2_USEC(tcp_rexmit_slop);
7641 	}
7642 	if (tp->t_rxtcur > rack_rto_max) {
7643 		tp->t_rxtcur = rack_rto_max;
7644 	}
7645 }
7646 
7647 static void
7648 rack_cc_conn_init(struct tcpcb *tp)
7649 {
7650 	struct tcp_rack *rack;
7651 	uint32_t srtt;
7652 
7653 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7654 	srtt = tp->t_srtt;
7655 	cc_conn_init(tp);
7656 	/*
7657 	 * Now convert to rack's internal format,
7658 	 * if required.
7659 	 */
7660 	if ((srtt == 0) && (tp->t_srtt != 0))
7661 		rack_convert_rtts(tp);
7662 	/*
7663 	 * We want a chance to stay in slowstart as
7664 	 * we create a connection. TCP spec says that
7665 	 * initially ssthresh is infinite. For our
7666 	 * purposes that is the snd_wnd.
7667 	 */
7668 	if (tp->snd_ssthresh < tp->snd_wnd) {
7669 		tp->snd_ssthresh = tp->snd_wnd;
7670 	}
7671 	/*
7672 	 * We also want to assure a IW worth of
7673 	 * data can get inflight.
7674 	 */
7675 	if (rc_init_window(rack) < tp->snd_cwnd)
7676 		tp->snd_cwnd = rc_init_window(rack);
7677 }
7678 
7679 /*
7680  * Re-transmit timeout! If we drop the PCB we will return 1, otherwise
7681  * we will setup to retransmit the lowest seq number outstanding.
7682  */
7683 static int
7684 rack_timeout_rxt(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
7685 {
7686 	struct inpcb *inp = tptoinpcb(tp);
7687 	int32_t rexmt;
7688 	int32_t retval = 0;
7689 	bool isipv6;
7690 
7691 	if ((tp->t_flags & TF_GPUTINPROG) &&
7692 	    (tp->t_rxtshift)) {
7693 		/*
7694 		 * We have had a second timeout
7695 		 * measurements on successive rxt's are not profitable.
7696 		 * It is unlikely to be of any use (the network is
7697 		 * broken or the client went away).
7698 		 */
7699 		tp->t_flags &= ~TF_GPUTINPROG;
7700 		rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
7701 					   rack->r_ctl.rc_gp_srtt /*flex1*/,
7702 					   tp->gput_seq,
7703 					   0, 0, 18, __LINE__, NULL, 0);
7704 	}
7705 	if (ctf_progress_timeout_check(tp, false)) {
7706 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
7707 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
7708 		return (-ETIMEDOUT);	/* tcp_drop() */
7709 	}
7710 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RXT;
7711 	rack->r_ctl.retran_during_recovery = 0;
7712 	rack->rc_ack_required = 1;
7713 	rack->r_ctl.dsack_byte_cnt = 0;
7714 	if (IN_FASTRECOVERY(tp->t_flags))
7715 		tp->t_flags |= TF_WASFRECOVERY;
7716 	else
7717 		tp->t_flags &= ~TF_WASFRECOVERY;
7718 	if (IN_CONGRECOVERY(tp->t_flags))
7719 		tp->t_flags |= TF_WASCRECOVERY;
7720 	else
7721 		tp->t_flags &= ~TF_WASCRECOVERY;
7722 	if (TCPS_HAVEESTABLISHED(tp->t_state) &&
7723 	    (tp->snd_una == tp->snd_max)) {
7724 		/* Nothing outstanding .. nothing to do */
7725 		return (0);
7726 	}
7727 	if (rack->r_ctl.dsack_persist) {
7728 		rack->r_ctl.dsack_persist--;
7729 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
7730 			rack->r_ctl.num_dsack = 0;
7731 		}
7732 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
7733 	}
7734 	/*
7735 	 * Rack can only run one timer  at a time, so we cannot
7736 	 * run a KEEPINIT (gating SYN sending) and a retransmit
7737 	 * timer for the SYN. So if we are in a front state and
7738 	 * have a KEEPINIT timer we need to check the first transmit
7739 	 * against now to see if we have exceeded the KEEPINIT time
7740 	 * (if one is set).
7741 	 */
7742 	if ((TCPS_HAVEESTABLISHED(tp->t_state) == 0) &&
7743 	    (TP_KEEPINIT(tp) != 0)) {
7744 		struct rack_sendmap *rsm;
7745 
7746 		rsm = tqhash_min(rack->r_ctl.tqh);
7747 		if (rsm) {
7748 			/* Ok we have something outstanding to test keepinit with */
7749 			if ((TSTMP_GT(cts, (uint32_t)rsm->r_tim_lastsent[0])) &&
7750 			    ((cts - (uint32_t)rsm->r_tim_lastsent[0]) >= TICKS_2_USEC(TP_KEEPINIT(tp)))) {
7751 				/* We have exceeded the KEEPINIT time */
7752 				tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
7753 				goto drop_it;
7754 			}
7755 		}
7756 	}
7757 	/*
7758 	 * Retransmission timer went off.  Message has not been acked within
7759 	 * retransmit interval.  Back off to a longer retransmit interval
7760 	 * and retransmit one segment.
7761 	 */
7762 	rack_remxt_tmr(tp);
7763 	if ((rack->r_ctl.rc_resend == NULL) ||
7764 	    ((rack->r_ctl.rc_resend->r_flags & RACK_RWND_COLLAPSED) == 0)) {
7765 		/*
7766 		 * If the rwnd collapsed on
7767 		 * the one we are retransmitting
7768 		 * it does not count against the
7769 		 * rxt count.
7770 		 */
7771 		tp->t_rxtshift++;
7772 	}
7773 	if (tp->t_rxtshift > TCP_MAXRXTSHIFT) {
7774 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
7775 drop_it:
7776 		tp->t_rxtshift = TCP_MAXRXTSHIFT;
7777 		KMOD_TCPSTAT_INC(tcps_timeoutdrop);
7778 		/* XXXGL: previously t_softerror was casted to uint16_t */
7779 		MPASS(tp->t_softerror >= 0);
7780 		retval = tp->t_softerror ? -tp->t_softerror : -ETIMEDOUT;
7781 		goto out;	/* tcp_drop() */
7782 	}
7783 	if (tp->t_state == TCPS_SYN_SENT) {
7784 		/*
7785 		 * If the SYN was retransmitted, indicate CWND to be limited
7786 		 * to 1 segment in cc_conn_init().
7787 		 */
7788 		tp->snd_cwnd = 1;
7789 	} else if (tp->t_rxtshift == 1) {
7790 		/*
7791 		 * first retransmit; record ssthresh and cwnd so they can be
7792 		 * recovered if this turns out to be a "bad" retransmit. A
7793 		 * retransmit is considered "bad" if an ACK for this segment
7794 		 * is received within RTT/2 interval; the assumption here is
7795 		 * that the ACK was already in flight.  See "On Estimating
7796 		 * End-to-End Network Path Properties" by Allman and Paxson
7797 		 * for more details.
7798 		 */
7799 		tp->snd_cwnd_prev = tp->snd_cwnd;
7800 		tp->snd_ssthresh_prev = tp->snd_ssthresh;
7801 		tp->snd_recover_prev = tp->snd_recover;
7802 		tp->t_badrxtwin = ticks + (USEC_2_TICKS(tp->t_srtt)/2);
7803 		tp->t_flags |= TF_PREVVALID;
7804 	} else if ((tp->t_flags & TF_RCVD_TSTMP) == 0)
7805 		tp->t_flags &= ~TF_PREVVALID;
7806 	KMOD_TCPSTAT_INC(tcps_rexmttimeo);
7807 	if ((tp->t_state == TCPS_SYN_SENT) ||
7808 	    (tp->t_state == TCPS_SYN_RECEIVED))
7809 		rexmt = RACK_INITIAL_RTO * tcp_backoff[tp->t_rxtshift];
7810 	else
7811 		rexmt = max(rack_rto_min, (tp->t_srtt + (tp->t_rttvar << 2))) * tcp_backoff[tp->t_rxtshift];
7812 
7813 	RACK_TCPT_RANGESET(tp->t_rxtcur, rexmt,
7814 	   max(rack_rto_min, rexmt), rack_rto_max, rack->r_ctl.timer_slop);
7815 	/*
7816 	 * We enter the path for PLMTUD if connection is established or, if
7817 	 * connection is FIN_WAIT_1 status, reason for the last is that if
7818 	 * amount of data we send is very small, we could send it in couple
7819 	 * of packets and process straight to FIN. In that case we won't
7820 	 * catch ESTABLISHED state.
7821 	 */
7822 #ifdef INET6
7823 	isipv6 = (inp->inp_vflag & INP_IPV6) ? true : false;
7824 #else
7825 	isipv6 = false;
7826 #endif
7827 	if (((V_tcp_pmtud_blackhole_detect == 1) ||
7828 	    (V_tcp_pmtud_blackhole_detect == 2 && !isipv6) ||
7829 	    (V_tcp_pmtud_blackhole_detect == 3 && isipv6)) &&
7830 	    ((tp->t_state == TCPS_ESTABLISHED) ||
7831 	    (tp->t_state == TCPS_FIN_WAIT_1))) {
7832 		/*
7833 		 * Idea here is that at each stage of mtu probe (usually,
7834 		 * 1448 -> 1188 -> 524) should be given 2 chances to recover
7835 		 * before further clamping down. 'tp->t_rxtshift % 2 == 0'
7836 		 * should take care of that.
7837 		 */
7838 		if (((tp->t_flags2 & (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) ==
7839 		    (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) &&
7840 		    (tp->t_rxtshift >= 2 && tp->t_rxtshift < 6 &&
7841 		    tp->t_rxtshift % 2 == 0)) {
7842 			/*
7843 			 * Enter Path MTU Black-hole Detection mechanism: -
7844 			 * Disable Path MTU Discovery (IP "DF" bit). -
7845 			 * Reduce MTU to lower value than what we negotiated
7846 			 * with peer.
7847 			 */
7848 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) == 0) {
7849 				/* Record that we may have found a black hole. */
7850 				tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE;
7851 				/* Keep track of previous MSS. */
7852 				tp->t_pmtud_saved_maxseg = tp->t_maxseg;
7853 			}
7854 
7855 			/*
7856 			 * Reduce the MSS to blackhole value or to the
7857 			 * default in an attempt to retransmit.
7858 			 */
7859 #ifdef INET6
7860 			if (isipv6 &&
7861 			    tp->t_maxseg > V_tcp_v6pmtud_blackhole_mss) {
7862 				/* Use the sysctl tuneable blackhole MSS. */
7863 				tp->t_maxseg = V_tcp_v6pmtud_blackhole_mss;
7864 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
7865 			} else if (isipv6) {
7866 				/* Use the default MSS. */
7867 				tp->t_maxseg = V_tcp_v6mssdflt;
7868 				/*
7869 				 * Disable Path MTU Discovery when we switch
7870 				 * to minmss.
7871 				 */
7872 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
7873 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
7874 			}
7875 #endif
7876 #if defined(INET6) && defined(INET)
7877 			else
7878 #endif
7879 #ifdef INET
7880 			if (tp->t_maxseg > V_tcp_pmtud_blackhole_mss) {
7881 				/* Use the sysctl tuneable blackhole MSS. */
7882 				tp->t_maxseg = V_tcp_pmtud_blackhole_mss;
7883 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
7884 			} else {
7885 				/* Use the default MSS. */
7886 				tp->t_maxseg = V_tcp_mssdflt;
7887 				/*
7888 				 * Disable Path MTU Discovery when we switch
7889 				 * to minmss.
7890 				 */
7891 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
7892 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
7893 			}
7894 #endif
7895 		} else {
7896 			/*
7897 			 * If further retransmissions are still unsuccessful
7898 			 * with a lowered MTU, maybe this isn't a blackhole
7899 			 * and we restore the previous MSS and blackhole
7900 			 * detection flags. The limit '6' is determined by
7901 			 * giving each probe stage (1448, 1188, 524) 2
7902 			 * chances to recover.
7903 			 */
7904 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) &&
7905 			    (tp->t_rxtshift >= 6)) {
7906 				tp->t_flags2 |= TF2_PLPMTU_PMTUD;
7907 				tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE;
7908 				tp->t_maxseg = tp->t_pmtud_saved_maxseg;
7909 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_failed);
7910 			}
7911 		}
7912 	}
7913 	/*
7914 	 * Disable RFC1323 and SACK if we haven't got any response to
7915 	 * our third SYN to work-around some broken terminal servers
7916 	 * (most of which have hopefully been retired) that have bad VJ
7917 	 * header compression code which trashes TCP segments containing
7918 	 * unknown-to-them TCP options.
7919 	 */
7920 	if (tcp_rexmit_drop_options && (tp->t_state == TCPS_SYN_SENT) &&
7921 	    (tp->t_rxtshift == 3))
7922 		tp->t_flags &= ~(TF_REQ_SCALE|TF_REQ_TSTMP|TF_SACK_PERMIT);
7923 	/*
7924 	 * If we backed off this far, our srtt estimate is probably bogus.
7925 	 * Clobber it so we'll take the next rtt measurement as our srtt;
7926 	 * move the current srtt into rttvar to keep the current retransmit
7927 	 * times until then.
7928 	 */
7929 	if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
7930 #ifdef INET6
7931 		if ((inp->inp_vflag & INP_IPV6) != 0)
7932 			in6_losing(inp);
7933 		else
7934 #endif
7935 			in_losing(inp);
7936 		tp->t_rttvar += tp->t_srtt;
7937 		tp->t_srtt = 0;
7938 	}
7939 	sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
7940 	tp->snd_recover = tp->snd_max;
7941 	tp->t_flags |= TF_ACKNOW;
7942 	tp->t_rtttime = 0;
7943 	rack_cong_signal(tp, CC_RTO, tp->snd_una, __LINE__);
7944 out:
7945 	return (retval);
7946 }
7947 
7948 static int
7949 rack_process_timers(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t hpts_calling, uint8_t *doing_tlp)
7950 {
7951 	int32_t ret = 0;
7952 	int32_t timers = (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK);
7953 
7954 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
7955 	    (tp->t_flags & TF_GPUTINPROG)) {
7956 		/*
7957 		 * We have a goodput in progress
7958 		 * and we have entered a late state.
7959 		 * Do we have enough data in the sb
7960 		 * to handle the GPUT request?
7961 		 */
7962 		uint32_t bytes;
7963 
7964 		bytes = tp->gput_ack - tp->gput_seq;
7965 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
7966 			bytes += tp->gput_seq - tp->snd_una;
7967 		if (bytes > sbavail(&tptosocket(tp)->so_snd)) {
7968 			/*
7969 			 * There are not enough bytes in the socket
7970 			 * buffer that have been sent to cover this
7971 			 * measurement. Cancel it.
7972 			 */
7973 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
7974 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
7975 						   tp->gput_seq,
7976 						   0, 0, 18, __LINE__, NULL, 0);
7977 			tp->t_flags &= ~TF_GPUTINPROG;
7978 		}
7979 	}
7980 	if (timers == 0) {
7981 		return (0);
7982 	}
7983 	if (tp->t_state == TCPS_LISTEN) {
7984 		/* no timers on listen sockets */
7985 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)
7986 			return (0);
7987 		return (1);
7988 	}
7989 	if ((timers & PACE_TMR_RACK) &&
7990 	    rack->rc_on_min_to) {
7991 		/*
7992 		 * For the rack timer when we
7993 		 * are on a min-timeout (which means rrr_conf = 3)
7994 		 * we don't want to check the timer. It may
7995 		 * be going off for a pace and thats ok we
7996 		 * want to send the retransmit (if its ready).
7997 		 *
7998 		 * If its on a normal rack timer (non-min) then
7999 		 * we will check if its expired.
8000 		 */
8001 		goto skip_time_check;
8002 	}
8003 	if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
8004 		uint32_t left;
8005 
8006 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
8007 			ret = -1;
8008 			rack_log_to_processing(rack, cts, ret, 0);
8009 			return (0);
8010 		}
8011 		if (hpts_calling == 0) {
8012 			/*
8013 			 * A user send or queued mbuf (sack) has called us? We
8014 			 * return 0 and let the pacing guards
8015 			 * deal with it if they should or
8016 			 * should not cause a send.
8017 			 */
8018 			ret = -2;
8019 			rack_log_to_processing(rack, cts, ret, 0);
8020 			return (0);
8021 		}
8022 		/*
8023 		 * Ok our timer went off early and we are not paced false
8024 		 * alarm, go back to sleep. We make sure we don't have
8025 		 * no-sack wakeup on since we no longer have a PKT_OUTPUT
8026 		 * flag in place.
8027 		 */
8028 		rack->rc_inp->inp_flags2 &= ~INP_DONT_SACK_QUEUE;
8029 		ret = -3;
8030 		left = rack->r_ctl.rc_timer_exp - cts;
8031 		tcp_hpts_insert(tptoinpcb(tp), HPTS_MS_TO_SLOTS(left));
8032 		rack_log_to_processing(rack, cts, ret, left);
8033 		return (1);
8034 	}
8035 skip_time_check:
8036 	rack->rc_tmr_stopped = 0;
8037 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_MASK;
8038 	if (timers & PACE_TMR_DELACK) {
8039 		ret = rack_timeout_delack(tp, rack, cts);
8040 	} else if (timers & PACE_TMR_RACK) {
8041 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
8042 		rack->r_fast_output = 0;
8043 		ret = rack_timeout_rack(tp, rack, cts);
8044 	} else if (timers & PACE_TMR_TLP) {
8045 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
8046 		ret = rack_timeout_tlp(tp, rack, cts, doing_tlp);
8047 	} else if (timers & PACE_TMR_RXT) {
8048 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
8049 		rack->r_fast_output = 0;
8050 		ret = rack_timeout_rxt(tp, rack, cts);
8051 	} else if (timers & PACE_TMR_PERSIT) {
8052 		ret = rack_timeout_persist(tp, rack, cts);
8053 	} else if (timers & PACE_TMR_KEEP) {
8054 		ret = rack_timeout_keepalive(tp, rack, cts);
8055 	}
8056 	rack_log_to_processing(rack, cts, ret, timers);
8057 	return (ret);
8058 }
8059 
8060 static void
8061 rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line)
8062 {
8063 	struct timeval tv;
8064 	uint32_t us_cts, flags_on_entry;
8065 	uint8_t hpts_removed = 0;
8066 
8067 	flags_on_entry = rack->r_ctl.rc_hpts_flags;
8068 	us_cts = tcp_get_usecs(&tv);
8069 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
8070 	    ((TSTMP_GEQ(us_cts, rack->r_ctl.rc_last_output_to)) ||
8071 	     ((tp->snd_max - tp->snd_una) == 0))) {
8072 		tcp_hpts_remove(rack->rc_inp);
8073 		hpts_removed = 1;
8074 		/* If we were not delayed cancel out the flag. */
8075 		if ((tp->snd_max - tp->snd_una) == 0)
8076 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
8077 		rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
8078 	}
8079 	if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
8080 		rack->rc_tmr_stopped = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
8081 		if (tcp_in_hpts(rack->rc_inp) &&
8082 		    ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)) {
8083 			/*
8084 			 * Canceling timer's when we have no output being
8085 			 * paced. We also must remove ourselves from the
8086 			 * hpts.
8087 			 */
8088 			tcp_hpts_remove(rack->rc_inp);
8089 			hpts_removed = 1;
8090 		}
8091 		rack->r_ctl.rc_hpts_flags &= ~(PACE_TMR_MASK);
8092 	}
8093 	if (hpts_removed == 0)
8094 		rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
8095 }
8096 
8097 static int
8098 rack_stopall(struct tcpcb *tp)
8099 {
8100 	struct tcp_rack *rack;
8101 	rack = (struct tcp_rack *)tp->t_fb_ptr;
8102 	rack->t_timers_stopped = 1;
8103 	return (0);
8104 }
8105 
8106 static void
8107 rack_stop_all_timers(struct tcpcb *tp, struct tcp_rack *rack)
8108 {
8109 	/*
8110 	 * Assure no timers are running.
8111 	 */
8112 	if (tcp_timer_active(tp, TT_PERSIST)) {
8113 		/* We enter in persists, set the flag appropriately */
8114 		rack->rc_in_persist = 1;
8115 	}
8116 	if (tcp_in_hpts(rack->rc_inp)) {
8117 		tcp_hpts_remove(rack->rc_inp);
8118 	}
8119 }
8120 
8121 static void
8122 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
8123     struct rack_sendmap *rsm, uint64_t ts, uint16_t add_flag, int segsiz)
8124 {
8125 	int32_t idx;
8126 
8127 	rsm->r_rtr_cnt++;
8128 	rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
8129 	rsm->r_dupack = 0;
8130 	if (rsm->r_rtr_cnt > RACK_NUM_OF_RETRANS) {
8131 		rsm->r_rtr_cnt = RACK_NUM_OF_RETRANS;
8132 		rsm->r_flags |= RACK_OVERMAX;
8133 	}
8134 	if ((rsm->r_rtr_cnt > 1) && ((rsm->r_flags & RACK_TLP) == 0)) {
8135 		rack->r_ctl.rc_holes_rxt += (rsm->r_end - rsm->r_start);
8136 		rsm->r_rtr_bytes += (rsm->r_end - rsm->r_start);
8137 	}
8138 	idx = rsm->r_rtr_cnt - 1;
8139 	rsm->r_tim_lastsent[idx] = ts;
8140 	/*
8141 	 * Here we don't add in the len of send, since its already
8142 	 * in snduna <->snd_max.
8143 	 */
8144 	rsm->r_fas = ctf_flight_size(rack->rc_tp,
8145 				     rack->r_ctl.rc_sacked);
8146 	if (rsm->r_flags & RACK_ACKED) {
8147 		/* Problably MTU discovery messing with us */
8148 		rsm->r_flags &= ~RACK_ACKED;
8149 		rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
8150 	}
8151 	if (rsm->r_in_tmap) {
8152 		TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8153 		rsm->r_in_tmap = 0;
8154 	}
8155 	/* Lets make sure it really is in or not the GP window */
8156 	rack_mark_in_gp_win(tp, rsm);
8157 	TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8158 	rsm->r_in_tmap = 1;
8159 	rsm->r_bas = (uint8_t)(((rsm->r_end - rsm->r_start) + segsiz - 1) / segsiz);
8160 	/* Take off the must retransmit flag, if its on */
8161 	if (rsm->r_flags & RACK_MUST_RXT) {
8162 		if (rack->r_must_retran)
8163 			rack->r_ctl.rc_out_at_rto -= (rsm->r_end - rsm->r_start);
8164 		if (SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) {
8165 			/*
8166 			 * We have retransmitted all we need. Clear
8167 			 * any must retransmit flags.
8168 			 */
8169 			rack->r_must_retran = 0;
8170 			rack->r_ctl.rc_out_at_rto = 0;
8171 		}
8172 		rsm->r_flags &= ~RACK_MUST_RXT;
8173 	}
8174 	/* Remove any collapsed flag */
8175 	rsm->r_flags &= ~RACK_RWND_COLLAPSED;
8176 	if (rsm->r_flags & RACK_SACK_PASSED) {
8177 		/* We have retransmitted due to the SACK pass */
8178 		rsm->r_flags &= ~RACK_SACK_PASSED;
8179 		rsm->r_flags |= RACK_WAS_SACKPASS;
8180 	}
8181 }
8182 
8183 static uint32_t
8184 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
8185     struct rack_sendmap *rsm, uint64_t ts, int32_t *lenp, uint16_t add_flag, int segsiz)
8186 {
8187 	/*
8188 	 * We (re-)transmitted starting at rsm->r_start for some length
8189 	 * (possibly less than r_end.
8190 	 */
8191 	struct rack_sendmap *nrsm;
8192 	int insret __diagused;
8193 	uint32_t c_end;
8194 	int32_t len;
8195 
8196 	len = *lenp;
8197 	c_end = rsm->r_start + len;
8198 	if (SEQ_GEQ(c_end, rsm->r_end)) {
8199 		/*
8200 		 * We retransmitted the whole piece or more than the whole
8201 		 * slopping into the next rsm.
8202 		 */
8203 		rack_update_rsm(tp, rack, rsm, ts, add_flag, segsiz);
8204 		if (c_end == rsm->r_end) {
8205 			*lenp = 0;
8206 			return (0);
8207 		} else {
8208 			int32_t act_len;
8209 
8210 			/* Hangs over the end return whats left */
8211 			act_len = rsm->r_end - rsm->r_start;
8212 			*lenp = (len - act_len);
8213 			return (rsm->r_end);
8214 		}
8215 		/* We don't get out of this block. */
8216 	}
8217 	/*
8218 	 * Here we retransmitted less than the whole thing which means we
8219 	 * have to split this into what was transmitted and what was not.
8220 	 */
8221 	nrsm = rack_alloc_full_limit(rack);
8222 	if (nrsm == NULL) {
8223 		/*
8224 		 * We can't get memory, so lets not proceed.
8225 		 */
8226 		*lenp = 0;
8227 		return (0);
8228 	}
8229 	/*
8230 	 * So here we are going to take the original rsm and make it what we
8231 	 * retransmitted. nrsm will be the tail portion we did not
8232 	 * retransmit. For example say the chunk was 1, 11 (10 bytes). And
8233 	 * we retransmitted 5 bytes i.e. 1, 5. The original piece shrinks to
8234 	 * 1, 6 and the new piece will be 6, 11.
8235 	 */
8236 	rack_clone_rsm(rack, nrsm, rsm, c_end);
8237 	nrsm->r_dupack = 0;
8238 	rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
8239 #ifndef INVARIANTS
8240 	(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
8241 #else
8242 	if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
8243 		panic("Insert in rb tree of %p fails ret:%d rack:%p rsm:%p",
8244 		      nrsm, insret, rack, rsm);
8245 	}
8246 #endif
8247 	if (rsm->r_in_tmap) {
8248 		TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8249 		nrsm->r_in_tmap = 1;
8250 	}
8251 	rsm->r_flags &= (~RACK_HAS_FIN);
8252 	rack_update_rsm(tp, rack, rsm, ts, add_flag, segsiz);
8253 	/* Log a split of rsm into rsm and nrsm */
8254 	rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
8255 	*lenp = 0;
8256 	return (0);
8257 }
8258 
8259 static void
8260 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
8261 		uint32_t seq_out, uint16_t th_flags, int32_t err, uint64_t cts,
8262 		struct rack_sendmap *hintrsm, uint16_t add_flag, struct mbuf *s_mb,
8263 		uint32_t s_moff, int hw_tls, int segsiz)
8264 {
8265 	struct tcp_rack *rack;
8266 	struct rack_sendmap *rsm, *nrsm;
8267 	int insret __diagused;
8268 
8269 	register uint32_t snd_max, snd_una;
8270 
8271 	/*
8272 	 * Add to the RACK log of packets in flight or retransmitted. If
8273 	 * there is a TS option we will use the TS echoed, if not we will
8274 	 * grab a TS.
8275 	 *
8276 	 * Retransmissions will increment the count and move the ts to its
8277 	 * proper place. Note that if options do not include TS's then we
8278 	 * won't be able to effectively use the ACK for an RTT on a retran.
8279 	 *
8280 	 * Notes about r_start and r_end. Lets consider a send starting at
8281 	 * sequence 1 for 10 bytes. In such an example the r_start would be
8282 	 * 1 (starting sequence) but the r_end would be r_start+len i.e. 11.
8283 	 * This means that r_end is actually the first sequence for the next
8284 	 * slot (11).
8285 	 *
8286 	 */
8287 	/*
8288 	 * If err is set what do we do XXXrrs? should we not add the thing?
8289 	 * -- i.e. return if err != 0 or should we pretend we sent it? --
8290 	 * i.e. proceed with add ** do this for now.
8291 	 */
8292 	INP_WLOCK_ASSERT(tptoinpcb(tp));
8293 	if (err)
8294 		/*
8295 		 * We don't log errors -- we could but snd_max does not
8296 		 * advance in this case either.
8297 		 */
8298 		return;
8299 
8300 	if (th_flags & TH_RST) {
8301 		/*
8302 		 * We don't log resets and we return immediately from
8303 		 * sending
8304 		 */
8305 		return;
8306 	}
8307 	rack = (struct tcp_rack *)tp->t_fb_ptr;
8308 	snd_una = tp->snd_una;
8309 	snd_max = tp->snd_max;
8310 	if (th_flags & (TH_SYN | TH_FIN)) {
8311 		/*
8312 		 * The call to rack_log_output is made before bumping
8313 		 * snd_max. This means we can record one extra byte on a SYN
8314 		 * or FIN if seq_out is adding more on and a FIN is present
8315 		 * (and we are not resending).
8316 		 */
8317 		if ((th_flags & TH_SYN) && (seq_out == tp->iss))
8318 			len++;
8319 		if (th_flags & TH_FIN)
8320 			len++;
8321 		if (SEQ_LT(snd_max, tp->snd_nxt)) {
8322 			/*
8323 			 * The add/update as not been done for the FIN/SYN
8324 			 * yet.
8325 			 */
8326 			snd_max = tp->snd_nxt;
8327 		}
8328 	}
8329 	if (SEQ_LEQ((seq_out + len), snd_una)) {
8330 		/* Are sending an old segment to induce an ack (keep-alive)? */
8331 		return;
8332 	}
8333 	if (SEQ_LT(seq_out, snd_una)) {
8334 		/* huh? should we panic? */
8335 		uint32_t end;
8336 
8337 		end = seq_out + len;
8338 		seq_out = snd_una;
8339 		if (SEQ_GEQ(end, seq_out))
8340 			len = end - seq_out;
8341 		else
8342 			len = 0;
8343 	}
8344 	if (len == 0) {
8345 		/* We don't log zero window probes */
8346 		return;
8347 	}
8348 	if (IN_FASTRECOVERY(tp->t_flags)) {
8349 		rack->r_ctl.rc_prr_out += len;
8350 	}
8351 	/* First question is it a retransmission or new? */
8352 	if (seq_out == snd_max) {
8353 		/* Its new */
8354 		rack_chk_http_and_hybrid_on_out(rack, seq_out, len, cts);
8355 again:
8356 		rsm = rack_alloc(rack);
8357 		if (rsm == NULL) {
8358 			/*
8359 			 * Hmm out of memory and the tcb got destroyed while
8360 			 * we tried to wait.
8361 			 */
8362 			return;
8363 		}
8364 		if (th_flags & TH_FIN) {
8365 			rsm->r_flags = RACK_HAS_FIN|add_flag;
8366 		} else {
8367 			rsm->r_flags = add_flag;
8368 		}
8369 		if (hw_tls)
8370 			rsm->r_hw_tls = 1;
8371 		rsm->r_tim_lastsent[0] = cts;
8372 		rsm->r_rtr_cnt = 1;
8373 		rsm->r_rtr_bytes = 0;
8374 		if (th_flags & TH_SYN) {
8375 			/* The data space is one beyond snd_una */
8376 			rsm->r_flags |= RACK_HAS_SYN;
8377 		}
8378 		rsm->r_start = seq_out;
8379 		rsm->r_end = rsm->r_start + len;
8380 		rack_mark_in_gp_win(tp, rsm);
8381 		rsm->r_dupack = 0;
8382 		/*
8383 		 * save off the mbuf location that
8384 		 * sndmbuf_noadv returned (which is
8385 		 * where we started copying from)..
8386 		 */
8387 		rsm->m = s_mb;
8388 		rsm->soff = s_moff;
8389 		/*
8390 		 * Here we do add in the len of send, since its not yet
8391 		 * reflected in in snduna <->snd_max
8392 		 */
8393 		rsm->r_fas = (ctf_flight_size(rack->rc_tp,
8394 					      rack->r_ctl.rc_sacked) +
8395 			      (rsm->r_end - rsm->r_start));
8396 		/* rsm->m will be NULL if RACK_HAS_SYN or RACK_HAS_FIN is set */
8397 		if (rsm->m) {
8398 			if (rsm->m->m_len <= rsm->soff) {
8399 				/*
8400 				 * XXXrrs Question, will this happen?
8401 				 *
8402 				 * If sbsndptr is set at the correct place
8403 				 * then s_moff should always be somewhere
8404 				 * within rsm->m. But if the sbsndptr was
8405 				 * off then that won't be true. If it occurs
8406 				 * we need to walkout to the correct location.
8407 				 */
8408 				struct mbuf *lm;
8409 
8410 				lm = rsm->m;
8411 				while (lm->m_len <= rsm->soff) {
8412 					rsm->soff -= lm->m_len;
8413 					lm = lm->m_next;
8414 					KASSERT(lm != NULL, ("%s rack:%p lm goes null orig_off:%u origmb:%p rsm->soff:%u",
8415 							     __func__, rack, s_moff, s_mb, rsm->soff));
8416 				}
8417 				rsm->m = lm;
8418 			}
8419 			rsm->orig_m_len = rsm->m->m_len;
8420 			rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
8421 		} else {
8422 			rsm->orig_m_len = 0;
8423 			rsm->orig_t_space = 0;
8424 		}
8425 		rsm->r_bas = (uint8_t)((len + segsiz - 1) / segsiz);
8426 		rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
8427 		/* Log a new rsm */
8428 		rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_NEW, 0, __LINE__);
8429 #ifndef INVARIANTS
8430 		(void)tqhash_insert(rack->r_ctl.tqh, rsm);
8431 #else
8432 		if ((insret = tqhash_insert(rack->r_ctl.tqh, rsm)) != 0) {
8433 			panic("Insert in rb tree of %p fails ret:%d rack:%p rsm:%p",
8434 			      nrsm, insret, rack, rsm);
8435 		}
8436 #endif
8437 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8438 		rsm->r_in_tmap = 1;
8439 		/*
8440 		 * Special case detection, is there just a single
8441 		 * packet outstanding when we are not in recovery?
8442 		 *
8443 		 * If this is true mark it so.
8444 		 */
8445 		if ((IN_FASTRECOVERY(tp->t_flags) == 0) &&
8446 		    (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) == ctf_fixed_maxseg(tp))) {
8447 			struct rack_sendmap *prsm;
8448 
8449 			prsm = tqhash_prev(rack->r_ctl.tqh, rsm);
8450 			if (prsm)
8451 				prsm->r_one_out_nr = 1;
8452 		}
8453 		return;
8454 	}
8455 	/*
8456 	 * If we reach here its a retransmission and we need to find it.
8457 	 */
8458 more:
8459 	if (hintrsm && (hintrsm->r_start == seq_out)) {
8460 		rsm = hintrsm;
8461 		hintrsm = NULL;
8462 	} else {
8463 		/* No hints sorry */
8464 		rsm = NULL;
8465 	}
8466 	if ((rsm) && (rsm->r_start == seq_out)) {
8467 		seq_out = rack_update_entry(tp, rack, rsm, cts, &len, add_flag, segsiz);
8468 		if (len == 0) {
8469 			return;
8470 		} else {
8471 			goto more;
8472 		}
8473 	}
8474 	/* Ok it was not the last pointer go through it the hard way. */
8475 refind:
8476 	rsm = tqhash_find(rack->r_ctl.tqh, seq_out);
8477 	if (rsm) {
8478 		if (rsm->r_start == seq_out) {
8479 			seq_out = rack_update_entry(tp, rack, rsm, cts, &len, add_flag, segsiz);
8480 			if (len == 0) {
8481 				return;
8482 			} else {
8483 				goto refind;
8484 			}
8485 		}
8486 		if (SEQ_GEQ(seq_out, rsm->r_start) && SEQ_LT(seq_out, rsm->r_end)) {
8487 			/* Transmitted within this piece */
8488 			/*
8489 			 * Ok we must split off the front and then let the
8490 			 * update do the rest
8491 			 */
8492 			nrsm = rack_alloc_full_limit(rack);
8493 			if (nrsm == NULL) {
8494 				rack_update_rsm(tp, rack, rsm, cts, add_flag, segsiz);
8495 				return;
8496 			}
8497 			/*
8498 			 * copy rsm to nrsm and then trim the front of rsm
8499 			 * to not include this part.
8500 			 */
8501 			rack_clone_rsm(rack, nrsm, rsm, seq_out);
8502 			rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
8503 #ifndef INVARIANTS
8504 			(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
8505 #else
8506 			if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
8507 				panic("Insert in rb tree of %p fails ret:%d rack:%p rsm:%p",
8508 				      nrsm, insret, rack, rsm);
8509 			}
8510 #endif
8511 			if (rsm->r_in_tmap) {
8512 				TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8513 				nrsm->r_in_tmap = 1;
8514 			}
8515 			rsm->r_flags &= (~RACK_HAS_FIN);
8516 			seq_out = rack_update_entry(tp, rack, nrsm, cts, &len, add_flag, segsiz);
8517 			if (len == 0) {
8518 				return;
8519 			} else if (len > 0)
8520 				goto refind;
8521 		}
8522 	}
8523 	/*
8524 	 * Hmm not found in map did they retransmit both old and on into the
8525 	 * new?
8526 	 */
8527 	if (seq_out == tp->snd_max) {
8528 		goto again;
8529 	} else if (SEQ_LT(seq_out, tp->snd_max)) {
8530 #ifdef INVARIANTS
8531 		printf("seq_out:%u len:%d snd_una:%u snd_max:%u -- but rsm not found?\n",
8532 		       seq_out, len, tp->snd_una, tp->snd_max);
8533 		printf("Starting Dump of all rack entries\n");
8534 		TQHASH_FOREACH(rsm, rack->r_ctl.tqh)  {
8535 			printf("rsm:%p start:%u end:%u\n",
8536 			       rsm, rsm->r_start, rsm->r_end);
8537 		}
8538 		printf("Dump complete\n");
8539 		panic("seq_out not found rack:%p tp:%p",
8540 		      rack, tp);
8541 #endif
8542 	} else {
8543 #ifdef INVARIANTS
8544 		/*
8545 		 * Hmm beyond sndmax? (only if we are using the new rtt-pack
8546 		 * flag)
8547 		 */
8548 		panic("seq_out:%u(%d) is beyond snd_max:%u tp:%p",
8549 		      seq_out, len, tp->snd_max, tp);
8550 #endif
8551 	}
8552 }
8553 
8554 /*
8555  * Record one of the RTT updates from an ack into
8556  * our sample structure.
8557  */
8558 
8559 static void
8560 tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt, uint32_t len, uint32_t us_rtt,
8561 		    int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt)
8562 {
8563 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
8564 	    (rack->r_ctl.rack_rs.rs_rtt_lowest > rtt)) {
8565 		rack->r_ctl.rack_rs.rs_rtt_lowest = rtt;
8566 	}
8567 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
8568 	    (rack->r_ctl.rack_rs.rs_rtt_highest < rtt)) {
8569 		rack->r_ctl.rack_rs.rs_rtt_highest = rtt;
8570 	}
8571 	if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
8572 	    if (us_rtt < rack->r_ctl.rc_gp_lowrtt)
8573 		rack->r_ctl.rc_gp_lowrtt = us_rtt;
8574 	    if (rack->rc_tp->snd_wnd > rack->r_ctl.rc_gp_high_rwnd)
8575 		    rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
8576 	}
8577 	if ((confidence == 1) &&
8578 	    ((rsm == NULL) ||
8579 	     (rsm->r_just_ret) ||
8580 	     (rsm->r_one_out_nr &&
8581 	      len < (ctf_fixed_maxseg(rack->rc_tp) * 2)))) {
8582 		/*
8583 		 * If the rsm had a just return
8584 		 * hit it then we can't trust the
8585 		 * rtt measurement for buffer deterimination
8586 		 * Note that a confidence of 2, indicates
8587 		 * SACK'd which overrides the r_just_ret or
8588 		 * the r_one_out_nr. If it was a CUM-ACK and
8589 		 * we had only two outstanding, but get an
8590 		 * ack for only 1. Then that also lowers our
8591 		 * confidence.
8592 		 */
8593 		confidence = 0;
8594 	}
8595 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
8596 	    (rack->r_ctl.rack_rs.rs_us_rtt > us_rtt)) {
8597 		if (rack->r_ctl.rack_rs.confidence == 0) {
8598 			/*
8599 			 * We take anything with no current confidence
8600 			 * saved.
8601 			 */
8602 			rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
8603 			rack->r_ctl.rack_rs.confidence = confidence;
8604 			rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
8605 		} else if (confidence != 0) {
8606 			/*
8607 			 * Once we have a confident number,
8608 			 * we can update it with a smaller
8609 			 * value since this confident number
8610 			 * may include the DSACK time until
8611 			 * the next segment (the second one) arrived.
8612 			 */
8613 			rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
8614 			rack->r_ctl.rack_rs.confidence = confidence;
8615 			rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
8616 		}
8617 	}
8618 	rack_log_rtt_upd(rack->rc_tp, rack, us_rtt, len, rsm, confidence);
8619 	rack->r_ctl.rack_rs.rs_flags = RACK_RTT_VALID;
8620 	rack->r_ctl.rack_rs.rs_rtt_tot += rtt;
8621 	rack->r_ctl.rack_rs.rs_rtt_cnt++;
8622 }
8623 
8624 /*
8625  * Collect new round-trip time estimate
8626  * and update averages and current timeout.
8627  */
8628 static void
8629 tcp_rack_xmit_timer_commit(struct tcp_rack *rack, struct tcpcb *tp)
8630 {
8631 	int32_t delta;
8632 	int32_t rtt;
8633 
8634 	if (rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY)
8635 		/* No valid sample */
8636 		return;
8637 	if (rack->r_ctl.rc_rate_sample_method == USE_RTT_LOW) {
8638 		/* We are to use the lowest RTT seen in a single ack */
8639 		rtt = rack->r_ctl.rack_rs.rs_rtt_lowest;
8640 	} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_HIGH) {
8641 		/* We are to use the highest RTT seen in a single ack */
8642 		rtt = rack->r_ctl.rack_rs.rs_rtt_highest;
8643 	} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_AVG) {
8644 		/* We are to use the average RTT seen in a single ack */
8645 		rtt = (int32_t)(rack->r_ctl.rack_rs.rs_rtt_tot /
8646 				(uint64_t)rack->r_ctl.rack_rs.rs_rtt_cnt);
8647 	} else {
8648 #ifdef INVARIANTS
8649 		panic("Unknown rtt variant %d", rack->r_ctl.rc_rate_sample_method);
8650 #endif
8651 		return;
8652 	}
8653 	if (rtt == 0)
8654 		rtt = 1;
8655 	if (rack->rc_gp_rtt_set == 0) {
8656 		/*
8657 		 * With no RTT we have to accept
8658 		 * even one we are not confident of.
8659 		 */
8660 		rack->r_ctl.rc_gp_srtt = rack->r_ctl.rack_rs.rs_us_rtt;
8661 		rack->rc_gp_rtt_set = 1;
8662 	} else if (rack->r_ctl.rack_rs.confidence) {
8663 		/* update the running gp srtt */
8664 		rack->r_ctl.rc_gp_srtt -= (rack->r_ctl.rc_gp_srtt/8);
8665 		rack->r_ctl.rc_gp_srtt += rack->r_ctl.rack_rs.rs_us_rtt / 8;
8666 	}
8667 	if (rack->r_ctl.rack_rs.confidence) {
8668 		/*
8669 		 * record the low and high for highly buffered path computation,
8670 		 * we only do this if we are confident (not a retransmission).
8671 		 */
8672 		if (rack->r_ctl.rc_highest_us_rtt < rack->r_ctl.rack_rs.rs_us_rtt) {
8673 			rack->r_ctl.rc_highest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
8674 		}
8675 		if (rack->rc_highly_buffered == 0) {
8676 			/*
8677 			 * Currently once we declare a path has
8678 			 * highly buffered there is no going
8679 			 * back, which may be a problem...
8680 			 */
8681 			if ((rack->r_ctl.rc_highest_us_rtt / rack->r_ctl.rc_lowest_us_rtt) > rack_hbp_thresh) {
8682 				rack_log_rtt_shrinks(rack, rack->r_ctl.rack_rs.rs_us_rtt,
8683 						     rack->r_ctl.rc_highest_us_rtt,
8684 						     rack->r_ctl.rc_lowest_us_rtt,
8685 						     RACK_RTTS_SEEHBP);
8686 				rack->rc_highly_buffered = 1;
8687 			}
8688 		}
8689 	}
8690 	if ((rack->r_ctl.rack_rs.confidence) ||
8691 	    (rack->r_ctl.rack_rs.rs_us_rtrcnt == 1)) {
8692 		/*
8693 		 * If we are highly confident of it <or> it was
8694 		 * never retransmitted we accept it as the last us_rtt.
8695 		 */
8696 		rack->r_ctl.rc_last_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
8697 		/* The lowest rtt can be set if its was not retransmited */
8698 		if (rack->r_ctl.rc_lowest_us_rtt > rack->r_ctl.rack_rs.rs_us_rtt) {
8699 			rack->r_ctl.rc_lowest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
8700 			if (rack->r_ctl.rc_lowest_us_rtt == 0)
8701 				rack->r_ctl.rc_lowest_us_rtt = 1;
8702 		}
8703 	}
8704 	rack = (struct tcp_rack *)tp->t_fb_ptr;
8705 	if (tp->t_srtt != 0) {
8706 		/*
8707 		 * We keep a simple srtt in microseconds, like our rtt
8708 		 * measurement. We don't need to do any tricks with shifting
8709 		 * etc. Instead we just add in 1/8th of the new measurement
8710 		 * and subtract out 1/8 of the old srtt. We do the same with
8711 		 * the variance after finding the absolute value of the
8712 		 * difference between this sample and the current srtt.
8713 		 */
8714 		delta = tp->t_srtt - rtt;
8715 		/* Take off 1/8th of the current sRTT */
8716 		tp->t_srtt -= (tp->t_srtt >> 3);
8717 		/* Add in 1/8th of the new RTT just measured */
8718 		tp->t_srtt += (rtt >> 3);
8719 		if (tp->t_srtt <= 0)
8720 			tp->t_srtt = 1;
8721 		/* Now lets make the absolute value of the variance */
8722 		if (delta < 0)
8723 			delta = -delta;
8724 		/* Subtract out 1/8th */
8725 		tp->t_rttvar -= (tp->t_rttvar >> 3);
8726 		/* Add in 1/8th of the new variance we just saw */
8727 		tp->t_rttvar += (delta >> 3);
8728 		if (tp->t_rttvar <= 0)
8729 			tp->t_rttvar = 1;
8730 	} else {
8731 		/*
8732 		 * No rtt measurement yet - use the unsmoothed rtt. Set the
8733 		 * variance to half the rtt (so our first retransmit happens
8734 		 * at 3*rtt).
8735 		 */
8736 		tp->t_srtt = rtt;
8737 		tp->t_rttvar = rtt >> 1;
8738 	}
8739 	rack->rc_srtt_measure_made = 1;
8740 	KMOD_TCPSTAT_INC(tcps_rttupdated);
8741 	if (tp->t_rttupdated < UCHAR_MAX)
8742 		tp->t_rttupdated++;
8743 #ifdef STATS
8744 	if (rack_stats_gets_ms_rtt == 0) {
8745 		/* Send in the microsecond rtt used for rxt timeout purposes */
8746 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rtt));
8747 	} else if (rack_stats_gets_ms_rtt == 1) {
8748 		/* Send in the millisecond rtt used for rxt timeout purposes */
8749 		int32_t ms_rtt;
8750 
8751 		/* Round up */
8752 		ms_rtt = (rtt + HPTS_USEC_IN_MSEC - 1) / HPTS_USEC_IN_MSEC;
8753 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, ms_rtt));
8754 	} else if (rack_stats_gets_ms_rtt == 2) {
8755 		/* Send in the millisecond rtt has close to the path RTT as we can get  */
8756 		int32_t ms_rtt;
8757 
8758 		/* Round up */
8759 		ms_rtt = (rack->r_ctl.rack_rs.rs_us_rtt + HPTS_USEC_IN_MSEC - 1) / HPTS_USEC_IN_MSEC;
8760 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, ms_rtt));
8761 	}  else {
8762 		/* Send in the microsecond rtt has close to the path RTT as we can get  */
8763 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rack->r_ctl.rack_rs.rs_us_rtt));
8764 	}
8765 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_PATHRTT, imax(0, rack->r_ctl.rack_rs.rs_us_rtt));
8766 #endif
8767 	/*
8768 	 * the retransmit should happen at rtt + 4 * rttvar. Because of the
8769 	 * way we do the smoothing, srtt and rttvar will each average +1/2
8770 	 * tick of bias.  When we compute the retransmit timer, we want 1/2
8771 	 * tick of rounding and 1 extra tick because of +-1/2 tick
8772 	 * uncertainty in the firing of the timer.  The bias will give us
8773 	 * exactly the 1.5 tick we need.  But, because the bias is
8774 	 * statistical, we have to test that we don't drop below the minimum
8775 	 * feasible timer (which is 2 ticks).
8776 	 */
8777 	tp->t_rxtshift = 0;
8778 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
8779 		      max(rack_rto_min, rtt + 2), rack_rto_max, rack->r_ctl.timer_slop);
8780 	rack_log_rtt_sample(rack, rtt);
8781 	tp->t_softerror = 0;
8782 }
8783 
8784 
8785 static void
8786 rack_apply_updated_usrtt(struct tcp_rack *rack, uint32_t us_rtt, uint32_t us_cts)
8787 {
8788 	/*
8789 	 * Apply to filter the inbound us-rtt at us_cts.
8790 	 */
8791 	uint32_t old_rtt;
8792 
8793 	old_rtt = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
8794 	apply_filter_min_small(&rack->r_ctl.rc_gp_min_rtt,
8795 			       us_rtt, us_cts);
8796 	if (old_rtt > us_rtt) {
8797 		/* We just hit a new lower rtt time */
8798 		rack_log_rtt_shrinks(rack,  us_cts,  old_rtt,
8799 				     __LINE__, RACK_RTTS_NEWRTT);
8800 		/*
8801 		 * Only count it if its lower than what we saw within our
8802 		 * calculated range.
8803 		 */
8804 		if ((old_rtt - us_rtt) > rack_min_rtt_movement) {
8805 			if (rack_probertt_lower_within &&
8806 			    rack->rc_gp_dyn_mul &&
8807 			    (rack->use_fixed_rate == 0) &&
8808 			    (rack->rc_always_pace)) {
8809 				/*
8810 				 * We are seeing a new lower rtt very close
8811 				 * to the time that we would have entered probe-rtt.
8812 				 * This is probably due to the fact that a peer flow
8813 				 * has entered probe-rtt. Lets go in now too.
8814 				 */
8815 				uint32_t val;
8816 
8817 				val = rack_probertt_lower_within * rack_time_between_probertt;
8818 				val /= 100;
8819 				if ((rack->in_probe_rtt == 0)  &&
8820 				    ((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= (rack_time_between_probertt - val)))	{
8821 					rack_enter_probertt(rack, us_cts);
8822 				}
8823 			}
8824 			rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
8825 		}
8826 	}
8827 }
8828 
8829 static int
8830 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
8831     struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack)
8832 {
8833 	uint32_t us_rtt;
8834 	int32_t i, all;
8835 	uint32_t t, len_acked;
8836 
8837 	if ((rsm->r_flags & RACK_ACKED) ||
8838 	    (rsm->r_flags & RACK_WAS_ACKED))
8839 		/* Already done */
8840 		return (0);
8841 	if (rsm->r_no_rtt_allowed) {
8842 		/* Not allowed */
8843 		return (0);
8844 	}
8845 	if (ack_type == CUM_ACKED) {
8846 		if (SEQ_GT(th_ack, rsm->r_end)) {
8847 			len_acked = rsm->r_end - rsm->r_start;
8848 			all = 1;
8849 		} else {
8850 			len_acked = th_ack - rsm->r_start;
8851 			all = 0;
8852 		}
8853 	} else {
8854 		len_acked = rsm->r_end - rsm->r_start;
8855 		all = 0;
8856 	}
8857 	if (rsm->r_rtr_cnt == 1) {
8858 
8859 		t = cts - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
8860 		if ((int)t <= 0)
8861 			t = 1;
8862 		if (!tp->t_rttlow || tp->t_rttlow > t)
8863 			tp->t_rttlow = t;
8864 		if (!rack->r_ctl.rc_rack_min_rtt ||
8865 		    SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
8866 			rack->r_ctl.rc_rack_min_rtt = t;
8867 			if (rack->r_ctl.rc_rack_min_rtt == 0) {
8868 				rack->r_ctl.rc_rack_min_rtt = 1;
8869 			}
8870 		}
8871 		if (TSTMP_GT(tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time), rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]))
8872 			us_rtt = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8873 		else
8874 			us_rtt = tcp_get_usecs(NULL) - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8875 		if (us_rtt == 0)
8876 			us_rtt = 1;
8877 		if (CC_ALGO(tp)->rttsample != NULL) {
8878 			/* Kick the RTT to the CC */
8879 			CC_ALGO(tp)->rttsample(&tp->t_ccv, us_rtt, 1, rsm->r_fas);
8880 		}
8881 		rack_apply_updated_usrtt(rack, us_rtt, tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time));
8882 		if (ack_type == SACKED) {
8883 			rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)], cts, 1);
8884 			tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt, 2 , rsm, rsm->r_rtr_cnt);
8885 		} else {
8886 			/*
8887 			 * We need to setup what our confidence
8888 			 * is in this ack.
8889 			 *
8890 			 * If the rsm was app limited and it is
8891 			 * less than a mss in length (the end
8892 			 * of the send) then we have a gap. If we
8893 			 * were app limited but say we were sending
8894 			 * multiple MSS's then we are more confident
8895 			 * int it.
8896 			 *
8897 			 * When we are not app-limited then we see if
8898 			 * the rsm is being included in the current
8899 			 * measurement, we tell this by the app_limited_needs_set
8900 			 * flag.
8901 			 *
8902 			 * Note that being cwnd blocked is not applimited
8903 			 * as well as the pacing delay between packets which
8904 			 * are sending only 1 or 2 MSS's also will show up
8905 			 * in the RTT. We probably need to examine this algorithm
8906 			 * a bit more and enhance it to account for the delay
8907 			 * between rsm's. We could do that by saving off the
8908 			 * pacing delay of each rsm (in an rsm) and then
8909 			 * factoring that in somehow though for now I am
8910 			 * not sure how :)
8911 			 */
8912 			int calc_conf = 0;
8913 
8914 			if (rsm->r_flags & RACK_APP_LIMITED) {
8915 				if (all && (len_acked <= ctf_fixed_maxseg(tp)))
8916 					calc_conf = 0;
8917 				else
8918 					calc_conf = 1;
8919 			} else if (rack->app_limited_needs_set == 0) {
8920 				calc_conf = 1;
8921 			} else {
8922 				calc_conf = 0;
8923 			}
8924 			rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)], cts, 2);
8925 			tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt,
8926 					    calc_conf, rsm, rsm->r_rtr_cnt);
8927 		}
8928 		if ((rsm->r_flags & RACK_TLP) &&
8929 		    (!IN_FASTRECOVERY(tp->t_flags))) {
8930 			/* Segment was a TLP and our retrans matched */
8931 			if (rack->r_ctl.rc_tlp_cwnd_reduce) {
8932 				rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
8933 			}
8934 		}
8935 		if ((rack->r_ctl.rc_rack_tmit_time == 0) ||
8936 		    (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
8937 			    (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]))) {
8938 			/* New more recent rack_tmit_time */
8939 			rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
8940 			if (rack->r_ctl.rc_rack_tmit_time == 0)
8941 				rack->r_ctl.rc_rack_tmit_time = 1;
8942 			rack->rc_rack_rtt = t;
8943 		}
8944 		return (1);
8945 	}
8946 	/*
8947 	 * We clear the soft/rxtshift since we got an ack.
8948 	 * There is no assurance we will call the commit() function
8949 	 * so we need to clear these to avoid incorrect handling.
8950 	 */
8951 	tp->t_rxtshift = 0;
8952 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
8953 		      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
8954 	tp->t_softerror = 0;
8955 	if (to && (to->to_flags & TOF_TS) &&
8956 	    (ack_type == CUM_ACKED) &&
8957 	    (to->to_tsecr) &&
8958 	    ((rsm->r_flags & RACK_OVERMAX) == 0)) {
8959 		/*
8960 		 * Now which timestamp does it match? In this block the ACK
8961 		 * must be coming from a previous transmission.
8962 		 */
8963 		for (i = 0; i < rsm->r_rtr_cnt; i++) {
8964 			if (rack_ts_to_msec(rsm->r_tim_lastsent[i]) == to->to_tsecr) {
8965 				t = cts - (uint32_t)rsm->r_tim_lastsent[i];
8966 				if ((int)t <= 0)
8967 					t = 1;
8968 				if (CC_ALGO(tp)->rttsample != NULL) {
8969 					/*
8970 					 * Kick the RTT to the CC, here
8971 					 * we lie a bit in that we know the
8972 					 * retransmission is correct even though
8973 					 * we retransmitted. This is because
8974 					 * we match the timestamps.
8975 					 */
8976 					if (TSTMP_GT(tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time), rsm->r_tim_lastsent[i]))
8977 						us_rtt = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - (uint32_t)rsm->r_tim_lastsent[i];
8978 					else
8979 						us_rtt = tcp_get_usecs(NULL) - (uint32_t)rsm->r_tim_lastsent[i];
8980 					CC_ALGO(tp)->rttsample(&tp->t_ccv, us_rtt, 1, rsm->r_fas);
8981 				}
8982 				if ((i + 1) < rsm->r_rtr_cnt) {
8983 					/*
8984 					 * The peer ack'd from our previous
8985 					 * transmission. We have a spurious
8986 					 * retransmission and thus we dont
8987 					 * want to update our rack_rtt.
8988 					 *
8989 					 * Hmm should there be a CC revert here?
8990 					 *
8991 					 */
8992 					return (0);
8993 				}
8994 				if (!tp->t_rttlow || tp->t_rttlow > t)
8995 					tp->t_rttlow = t;
8996 				if (!rack->r_ctl.rc_rack_min_rtt || SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
8997 					rack->r_ctl.rc_rack_min_rtt = t;
8998 					if (rack->r_ctl.rc_rack_min_rtt == 0) {
8999 						rack->r_ctl.rc_rack_min_rtt = 1;
9000 					}
9001 				}
9002 				if ((rack->r_ctl.rc_rack_tmit_time == 0) ||
9003 				    (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
9004 					    (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]))) {
9005 					/* New more recent rack_tmit_time */
9006 					rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
9007 					if (rack->r_ctl.rc_rack_tmit_time == 0)
9008 						rack->r_ctl.rc_rack_tmit_time = 1;
9009 					rack->rc_rack_rtt = t;
9010 				}
9011 				rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[i], cts, 3);
9012 				tcp_rack_xmit_timer(rack, t + 1, len_acked, t, 0, rsm,
9013 						    rsm->r_rtr_cnt);
9014 				return (1);
9015 			}
9016 		}
9017 		/* If we are logging log out the sendmap */
9018 		if (tcp_bblogging_on(rack->rc_tp)) {
9019 			for (i = 0; i < rsm->r_rtr_cnt; i++) {
9020 				rack_log_rtt_sendmap(rack, i, rsm->r_tim_lastsent[i], to->to_tsecr);
9021 			}
9022 		}
9023 		goto ts_not_found;
9024 	} else {
9025 		/*
9026 		 * Ok its a SACK block that we retransmitted. or a windows
9027 		 * machine without timestamps. We can tell nothing from the
9028 		 * time-stamp since its not there or the time the peer last
9029 		 * recieved a segment that moved forward its cum-ack point.
9030 		 */
9031 ts_not_found:
9032 		i = rsm->r_rtr_cnt - 1;
9033 		t = cts - (uint32_t)rsm->r_tim_lastsent[i];
9034 		if ((int)t <= 0)
9035 			t = 1;
9036 		if (rack->r_ctl.rc_rack_min_rtt && SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
9037 			/*
9038 			 * We retransmitted and the ack came back in less
9039 			 * than the smallest rtt we have observed. We most
9040 			 * likely did an improper retransmit as outlined in
9041 			 * 6.2 Step 2 point 2 in the rack-draft so we
9042 			 * don't want to update our rack_rtt. We in
9043 			 * theory (in future) might want to think about reverting our
9044 			 * cwnd state but we won't for now.
9045 			 */
9046 			return (0);
9047 		} else if (rack->r_ctl.rc_rack_min_rtt) {
9048 			/*
9049 			 * We retransmitted it and the retransmit did the
9050 			 * job.
9051 			 */
9052 			if (!rack->r_ctl.rc_rack_min_rtt ||
9053 			    SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
9054 				rack->r_ctl.rc_rack_min_rtt = t;
9055 				if (rack->r_ctl.rc_rack_min_rtt == 0) {
9056 					rack->r_ctl.rc_rack_min_rtt = 1;
9057 				}
9058 			}
9059 			if ((rack->r_ctl.rc_rack_tmit_time == 0) ||
9060 			    (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
9061 				    (uint32_t)rsm->r_tim_lastsent[i]))) {
9062 				/* New more recent rack_tmit_time */
9063 				rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[i];
9064 				if (rack->r_ctl.rc_rack_tmit_time == 0)
9065 					rack->r_ctl.rc_rack_tmit_time = 1;
9066 				rack->rc_rack_rtt = t;
9067 			}
9068 			return (1);
9069 		}
9070 	}
9071 	return (0);
9072 }
9073 
9074 /*
9075  * Mark the SACK_PASSED flag on all entries prior to rsm send wise.
9076  */
9077 static void
9078 rack_log_sack_passed(struct tcpcb *tp,
9079     struct tcp_rack *rack, struct rack_sendmap *rsm)
9080 {
9081 	struct rack_sendmap *nrsm;
9082 
9083 	nrsm = rsm;
9084 	TAILQ_FOREACH_REVERSE_FROM(nrsm, &rack->r_ctl.rc_tmap,
9085 	    rack_head, r_tnext) {
9086 		if (nrsm == rsm) {
9087 			/* Skip original segment he is acked */
9088 			continue;
9089 		}
9090 		if (nrsm->r_flags & RACK_ACKED) {
9091 			/*
9092 			 * Skip ack'd segments, though we
9093 			 * should not see these, since tmap
9094 			 * should not have ack'd segments.
9095 			 */
9096 			continue;
9097 		}
9098 		if (nrsm->r_flags & RACK_RWND_COLLAPSED) {
9099 			/*
9100 			 * If the peer dropped the rwnd on
9101 			 * these then we don't worry about them.
9102 			 */
9103 			continue;
9104 		}
9105 		if (nrsm->r_flags & RACK_SACK_PASSED) {
9106 			/*
9107 			 * We found one that is already marked
9108 			 * passed, we have been here before and
9109 			 * so all others below this are marked.
9110 			 */
9111 			break;
9112 		}
9113 		nrsm->r_flags |= RACK_SACK_PASSED;
9114 		nrsm->r_flags &= ~RACK_WAS_SACKPASS;
9115 	}
9116 }
9117 
9118 static void
9119 rack_need_set_test(struct tcpcb *tp,
9120 		   struct tcp_rack *rack,
9121 		   struct rack_sendmap *rsm,
9122 		   tcp_seq th_ack,
9123 		   int line,
9124 		   int use_which)
9125 {
9126 	struct rack_sendmap *s_rsm;
9127 
9128 	if ((tp->t_flags & TF_GPUTINPROG) &&
9129 	    SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
9130 		/*
9131 		 * We were app limited, and this ack
9132 		 * butts up or goes beyond the point where we want
9133 		 * to start our next measurement. We need
9134 		 * to record the new gput_ts as here and
9135 		 * possibly update the start sequence.
9136 		 */
9137 		uint32_t seq, ts;
9138 
9139 		if (rsm->r_rtr_cnt > 1) {
9140 			/*
9141 			 * This is a retransmit, can we
9142 			 * really make any assessment at this
9143 			 * point?  We are not really sure of
9144 			 * the timestamp, is it this or the
9145 			 * previous transmission?
9146 			 *
9147 			 * Lets wait for something better that
9148 			 * is not retransmitted.
9149 			 */
9150 			return;
9151 		}
9152 		seq = tp->gput_seq;
9153 		ts = tp->gput_ts;
9154 		rack->app_limited_needs_set = 0;
9155 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
9156 		/* Do we start at a new end? */
9157 		if ((use_which == RACK_USE_BEG) &&
9158 		    SEQ_GEQ(rsm->r_start, tp->gput_seq)) {
9159 			/*
9160 			 * When we get an ACK that just eats
9161 			 * up some of the rsm, we set RACK_USE_BEG
9162 			 * since whats at r_start (i.e. th_ack)
9163 			 * is left unacked and thats where the
9164 			 * measurement now starts.
9165 			 */
9166 			tp->gput_seq = rsm->r_start;
9167 		}
9168 		if ((use_which == RACK_USE_END) &&
9169 		    SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
9170 			/*
9171 			 * We use the end when the cumack
9172 			 * is moving forward and completely
9173 			 * deleting the rsm passed so basically
9174 			 * r_end holds th_ack.
9175 			 *
9176 			 * For SACK's we also want to use the end
9177 			 * since this piece just got sacked and
9178 			 * we want to target anything after that
9179 			 * in our measurement.
9180 			 */
9181 			tp->gput_seq = rsm->r_end;
9182 		}
9183 		if (use_which == RACK_USE_END_OR_THACK) {
9184 			/*
9185 			 * special case for ack moving forward,
9186 			 * not a sack, we need to move all the
9187 			 * way up to where this ack cum-ack moves
9188 			 * to.
9189 			 */
9190 			if (SEQ_GT(th_ack, rsm->r_end))
9191 				tp->gput_seq = th_ack;
9192 			else
9193 				tp->gput_seq = rsm->r_end;
9194 		}
9195 		if (SEQ_LT(tp->gput_seq, tp->snd_max))
9196 			s_rsm = tqhash_find(rack->r_ctl.tqh, tp->gput_seq);
9197 		else
9198 			s_rsm = NULL;
9199 		/*
9200 		 * Pick up the correct send time if we can the rsm passed in
9201 		 * may be equal to s_rsm if the RACK_USE_BEG was set. For the other
9202 		 * two cases (RACK_USE_THACK or RACK_USE_END) most likely we will
9203 		 * find a different seq i.e. the next send up.
9204 		 *
9205 		 * If that has not been sent, s_rsm will be NULL and we must
9206 		 * arrange it so this function will get called again by setting
9207 		 * app_limited_needs_set.
9208 		 */
9209 		if (s_rsm)
9210 			rack->r_ctl.rc_gp_output_ts = s_rsm->r_tim_lastsent[0];
9211 		else {
9212 			/* If we hit here we have to have *not* sent tp->gput_seq */
9213 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[0];
9214 			/* Set it up so we will go through here again */
9215 			rack->app_limited_needs_set = 1;
9216 		}
9217 		if (SEQ_GT(tp->gput_seq, tp->gput_ack)) {
9218 			/*
9219 			 * We moved beyond this guy's range, re-calculate
9220 			 * the new end point.
9221 			 */
9222 			if (rack->rc_gp_filled == 0) {
9223 				tp->gput_ack = tp->gput_seq + max(rc_init_window(rack), (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
9224 			} else {
9225 				tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
9226 			}
9227 		}
9228 		/*
9229 		 * We are moving the goal post, we may be able to clear the
9230 		 * measure_saw_probe_rtt flag.
9231 		 */
9232 		if ((rack->in_probe_rtt == 0) &&
9233 		    (rack->measure_saw_probe_rtt) &&
9234 		    (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
9235 			rack->measure_saw_probe_rtt = 0;
9236 		rack_log_pacing_delay_calc(rack, ts, tp->gput_ts,
9237 					   seq, tp->gput_seq,
9238 					   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) |
9239 					    (uint64_t)rack->r_ctl.rc_gp_output_ts),
9240 					   5, line, NULL, 0);
9241 		if (rack->rc_gp_filled &&
9242 		    ((tp->gput_ack - tp->gput_seq) <
9243 		     max(rc_init_window(rack), (MIN_GP_WIN *
9244 						ctf_fixed_maxseg(tp))))) {
9245 			uint32_t ideal_amount;
9246 
9247 			ideal_amount = rack_get_measure_window(tp, rack);
9248 			if (ideal_amount > sbavail(&tptosocket(tp)->so_snd)) {
9249 				/*
9250 				 * There is no sense of continuing this measurement
9251 				 * because its too small to gain us anything we
9252 				 * trust. Skip it and that way we can start a new
9253 				 * measurement quicker.
9254 				 */
9255 				tp->t_flags &= ~TF_GPUTINPROG;
9256 				rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
9257 							   0, 0,
9258 							   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) |
9259 							    (uint64_t)rack->r_ctl.rc_gp_output_ts),
9260 							   6, __LINE__, NULL, 0);
9261 			} else {
9262 				/*
9263 				 * Reset the window further out.
9264 				 */
9265 				tp->gput_ack = tp->gput_seq + ideal_amount;
9266 			}
9267 		}
9268 		rack_tend_gp_marks(tp, rack);
9269 		rack_log_gpset(rack, tp->gput_ack, 0, 0, line, 2, rsm);
9270 	}
9271 }
9272 
9273 static inline int
9274 is_rsm_inside_declared_tlp_block(struct tcp_rack *rack, struct rack_sendmap *rsm)
9275 {
9276 	if (SEQ_LT(rsm->r_end, rack->r_ctl.last_tlp_acked_start)) {
9277 		/* Behind our TLP definition or right at */
9278 		return (0);
9279 	}
9280 	if (SEQ_GT(rsm->r_start, rack->r_ctl.last_tlp_acked_end)) {
9281 		/* The start is beyond or right at our end of TLP definition */
9282 		return (0);
9283 	}
9284 	/* It has to be a sub-part of the original TLP recorded */
9285 	return (1);
9286 }
9287 
9288 
9289 
9290 static uint32_t
9291 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack, struct sackblk *sack,
9292 		   struct tcpopt *to, struct rack_sendmap **prsm, uint32_t cts,
9293 		   int *no_extra,
9294 		   int *moved_two, uint32_t segsiz)
9295 {
9296 	uint32_t start, end, changed = 0;
9297 	struct rack_sendmap stack_map;
9298 	struct rack_sendmap *rsm, *nrsm, *prev, *next;
9299 	int insret __diagused;
9300 	int32_t used_ref = 1;
9301 	int moved = 0;
9302 #ifdef TCP_SAD_DETECTION
9303 	int allow_segsiz;
9304 	int first_time_through = 1;
9305 #endif
9306 	int noextra = 0;
9307 	int can_use_hookery = 0;
9308 
9309 	start = sack->start;
9310 	end = sack->end;
9311 	rsm = *prsm;
9312 
9313 #ifdef TCP_SAD_DETECTION
9314 	/*
9315 	 * There are a strange number of proxys and meddle boxes in the world
9316 	 * that seem to cut up segments on different boundaries. This gets us
9317 	 * smaller sacks that are still ok in terms of it being an attacker.
9318 	 * We use the base segsiz to calculate an allowable smallness but
9319 	 * also enforce a min on the segsiz in case it is an attacker playing
9320 	 * games with MSS. So basically if the sack arrives and it is
9321 	 * larger than a worse case 960 bytes, we don't classify the guy
9322 	 * as supicious.
9323 	 */
9324 	allow_segsiz = max(segsiz, 1200) * sad_seg_size_per;
9325 	allow_segsiz /= 1000;
9326 #endif
9327 do_rest_ofb:
9328 	if ((rsm == NULL) ||
9329 	    (SEQ_LT(end, rsm->r_start)) ||
9330 	    (SEQ_GEQ(start, rsm->r_end)) ||
9331 	    (SEQ_LT(start, rsm->r_start))) {
9332 		/*
9333 		 * We are not in the right spot,
9334 		 * find the correct spot in the tree.
9335 		 */
9336 		used_ref = 0;
9337 		rsm = tqhash_find(rack->r_ctl.tqh, start);
9338 		moved++;
9339 	}
9340 	if (rsm == NULL) {
9341 		/* TSNH */
9342 		goto out;
9343 	}
9344 #ifdef TCP_SAD_DETECTION
9345 	/* Now we must check for suspicous activity */
9346 	if ((first_time_through == 1) &&
9347 	    ((end - start) < min((rsm->r_end - rsm->r_start), allow_segsiz)) &&
9348 	    ((rsm->r_flags & RACK_PMTU_CHG) == 0) &&
9349 	    ((rsm->r_flags & RACK_TLP) == 0)) {
9350 		/*
9351 		 * Its less than a full MSS or the segment being acked
9352 		 * this should only happen if the rsm in question had the
9353 		 * r_just_ret flag set <and> the end matches the end of
9354 		 * the rsm block.
9355 		 *
9356 		 * Note we do not look at segments that have had TLP's on
9357 		 * them since we can get un-reported rwnd collapses that
9358 		 * basically we TLP on and then we get back a sack block
9359 		 * that goes from the start to only a small way.
9360 		 *
9361 		 */
9362 		int loss, ok;
9363 
9364 		ok = 0;
9365 		if (SEQ_GEQ(end, rsm->r_end)) {
9366 			if (rsm->r_just_ret == 1) {
9367 				/* This was at the end of a send which is ok */
9368 				ok = 1;
9369 			} else {
9370 				/* A bit harder was it the end of our segment */
9371 				int segs, len;
9372 
9373 				len = (rsm->r_end - rsm->r_start);
9374 				segs = len / segsiz;
9375 				segs *= segsiz;
9376 				if ((segs + (rsm->r_end - start)) == len) {
9377 					/*
9378 					 * So this last bit was the
9379 					 * end of our send if we cut it
9380 					 * up into segsiz pieces so its ok.
9381 					 */
9382 					ok = 1;
9383 				}
9384 			}
9385 		}
9386 		if (ok == 0) {
9387 			/*
9388 			 * This guy is doing something suspicious
9389 			 * lets start detection.
9390 			 */
9391 			if (rack->rc_suspicious == 0) {
9392 				tcp_trace_point(rack->rc_tp, TCP_TP_SAD_SUSPECT);
9393 				counter_u64_add(rack_sack_attacks_suspect, 1);
9394 				rack->rc_suspicious = 1;
9395 				rack_log_sad(rack, 4);
9396 				if (tcp_bblogging_on(rack->rc_tp)) {
9397 					union tcp_log_stackspecific log;
9398 					struct timeval tv;
9399 
9400 					memset(&log.u_bbr, 0, sizeof(log.u_bbr));
9401 					log.u_bbr.flex1 = end;
9402 					log.u_bbr.flex2 = start;
9403 					log.u_bbr.flex3 = rsm->r_end;
9404 					log.u_bbr.flex4 = rsm->r_start;
9405 					log.u_bbr.flex5 = segsiz;
9406 					log.u_bbr.flex6 = rsm->r_fas;
9407 					log.u_bbr.flex7 = rsm->r_bas;
9408 					log.u_bbr.flex8 = 5;
9409 					log.u_bbr.pkts_out = rsm->r_flags;
9410 					log.u_bbr.bbr_state = rack->rc_suspicious;
9411 					log.u_bbr.bbr_substate = rsm->r_just_ret;
9412 					log.u_bbr.timeStamp = tcp_get_usecs(&tv);
9413 					log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
9414 					TCP_LOG_EVENTP(rack->rc_tp, NULL,
9415 						       &rack->rc_inp->inp_socket->so_rcv,
9416 						       &rack->rc_inp->inp_socket->so_snd,
9417 						       TCP_SAD_DETECTION, 0,
9418 						       0, &log, false, &tv);
9419 				}
9420 			}
9421 			/* You loose some ack count every time you sack
9422 			 * a small bit that is not butting to the end of
9423 			 * what we have sent. This is because we never
9424 			 * send small bits unless its the end of the sb.
9425 			 * Anyone sending a sack that is not at the end
9426 			 * is thus very very suspicious.
9427 			 */
9428 			loss = (segsiz/2) / (end - start);
9429 			if (loss < rack->r_ctl.ack_count)
9430 				rack->r_ctl.ack_count -= loss;
9431 			else
9432 				rack->r_ctl.ack_count = 0;
9433 		}
9434 	}
9435 	first_time_through = 0;
9436 #endif
9437 	/* Ok we have an ACK for some piece of this rsm */
9438 	if (rsm->r_start != start) {
9439 		if ((rsm->r_flags & RACK_ACKED) == 0) {
9440 			/*
9441 			 * Before any splitting or hookery is
9442 			 * done is it a TLP of interest i.e. rxt?
9443 			 */
9444 			if ((rsm->r_flags & RACK_TLP) &&
9445 			    (rsm->r_rtr_cnt > 1)) {
9446 				/*
9447 				 * We are splitting a rxt TLP, check
9448 				 * if we need to save off the start/end
9449 				 */
9450 				if (rack->rc_last_tlp_acked_set &&
9451 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
9452 					/*
9453 					 * We already turned this on since we are inside
9454 					 * the previous one was a partially sack now we
9455 					 * are getting another one (maybe all of it).
9456 					 *
9457 					 */
9458 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
9459 					/*
9460 					 * Lets make sure we have all of it though.
9461 					 */
9462 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
9463 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9464 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9465 								     rack->r_ctl.last_tlp_acked_end);
9466 					}
9467 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
9468 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9469 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9470 								     rack->r_ctl.last_tlp_acked_end);
9471 					}
9472 				} else {
9473 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9474 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9475 					rack->rc_last_tlp_past_cumack = 0;
9476 					rack->rc_last_tlp_acked_set = 1;
9477 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
9478 				}
9479 			}
9480 			/**
9481 			 * Need to split this in two pieces the before and after,
9482 			 * the before remains in the map, the after must be
9483 			 * added. In other words we have:
9484 			 * rsm        |--------------|
9485 			 * sackblk        |------->
9486 			 * rsm will become
9487 			 *     rsm    |---|
9488 			 * and nrsm will be  the sacked piece
9489 			 *     nrsm       |----------|
9490 			 *
9491 			 * But before we start down that path lets
9492 			 * see if the sack spans over on top of
9493 			 * the next guy and it is already sacked.
9494 			 *
9495 			 */
9496 			/*
9497 			 * Hookery can only be used if the two entries
9498 			 * are in the same bucket and neither one of
9499 			 * them staddle the bucket line.
9500 			 */
9501 			next = tqhash_next(rack->r_ctl.tqh, rsm);
9502 			if (next &&
9503 			    (rsm->bindex == next->bindex) &&
9504 			    ((rsm->r_flags & RACK_STRADDLE) == 0) &&
9505 			    ((next->r_flags & RACK_STRADDLE) == 0) &&
9506 			    (rsm->r_flags & RACK_IN_GP_WIN) &&
9507 			    (next->r_flags & RACK_IN_GP_WIN))
9508 				can_use_hookery = 1;
9509 			else if (next &&
9510 				 (rsm->bindex == next->bindex) &&
9511 				 ((rsm->r_flags & RACK_STRADDLE) == 0) &&
9512 				 ((next->r_flags & RACK_STRADDLE) == 0) &&
9513 				 ((rsm->r_flags & RACK_IN_GP_WIN) == 0) &&
9514 				 ((next->r_flags & RACK_IN_GP_WIN) == 0))
9515 				can_use_hookery = 1;
9516 			else
9517 				can_use_hookery = 0;
9518 			if (next && can_use_hookery &&
9519 			    (next->r_flags & RACK_ACKED) &&
9520 			    SEQ_GEQ(end, next->r_start)) {
9521 				/**
9522 				 * So the next one is already acked, and
9523 				 * we can thus by hookery use our stack_map
9524 				 * to reflect the piece being sacked and
9525 				 * then adjust the two tree entries moving
9526 				 * the start and ends around. So we start like:
9527 				 *  rsm     |------------|             (not-acked)
9528 				 *  next                 |-----------| (acked)
9529 				 *  sackblk        |-------->
9530 				 *  We want to end like so:
9531 				 *  rsm     |------|                   (not-acked)
9532 				 *  next           |-----------------| (acked)
9533 				 *  nrsm           |-----|
9534 				 * Where nrsm is a temporary stack piece we
9535 				 * use to update all the gizmos.
9536 				 */
9537 				/* Copy up our fudge block */
9538 				noextra++;
9539 				nrsm = &stack_map;
9540 				memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
9541 				/* Now adjust our tree blocks */
9542 				rsm->r_end = start;
9543 				next->r_start = start;
9544  				rsm->r_flags |= RACK_SHUFFLED;
9545 				next->r_flags |= RACK_SHUFFLED;
9546 				/* Now we must adjust back where next->m is */
9547 				rack_setup_offset_for_rsm(rack, rsm, next);
9548 				/*
9549 				 * Which timestamp do we keep? It is rather
9550 				 * important in GP measurements to have the
9551 				 * accurate end of the send window.
9552 				 *
9553 				 * We keep the largest value, which is the newest
9554 				 * send. We do this in case a segment that is
9555 				 * joined together and not part of a GP estimate
9556 				 * later gets expanded into the GP estimate.
9557 				 *
9558 				 * We prohibit the merging of unlike kinds i.e.
9559 				 * all pieces that are in the GP estimate can be
9560 				 * merged and all pieces that are not in a GP estimate
9561 				 * can be merged, but not disimilar pieces. Combine
9562 				 * this with taking the highest here and we should
9563 				 * be ok unless of course the client reneges. Then
9564 				 * all bets are off.
9565 				 */
9566 				if (next->r_tim_lastsent[(next->r_rtr_cnt-1)] <
9567 				    nrsm->r_tim_lastsent[(nrsm->r_rtr_cnt-1)])
9568 					next->r_tim_lastsent[(next->r_rtr_cnt-1)] = nrsm->r_tim_lastsent[(nrsm->r_rtr_cnt-1)];
9569 				/*
9570 				 * And we must keep the newest ack arrival time.
9571 				 */
9572 				if (next->r_ack_arrival <
9573 				    rack_to_usec_ts(&rack->r_ctl.act_rcv_time))
9574 					next->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
9575 
9576 
9577 				/* We don't need to adjust rsm, it did not change */
9578 				/* Clear out the dup ack count of the remainder */
9579 				rsm->r_dupack = 0;
9580 				rsm->r_just_ret = 0;
9581 				rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
9582 				/* Now lets make sure our fudge block is right */
9583 				nrsm->r_start = start;
9584 				/* Now lets update all the stats and such */
9585 				rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
9586 				if (rack->app_limited_needs_set)
9587 					rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
9588 				changed += (nrsm->r_end - nrsm->r_start);
9589 				/* You get a count for acking a whole segment or more */
9590 				if ((nrsm->r_end - nrsm->r_start) >= segsiz)
9591 					rack->r_ctl.ack_count += ((nrsm->r_end - nrsm->r_start) / segsiz);
9592 				rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
9593 				if (nrsm->r_flags & RACK_SACK_PASSED) {
9594 					rack->r_ctl.rc_reorder_ts = cts;
9595 					if (rack->r_ctl.rc_reorder_ts == 0)
9596 						rack->r_ctl.rc_reorder_ts = 1;
9597 				}
9598 				/*
9599 				 * Now we want to go up from rsm (the
9600 				 * one left un-acked) to the next one
9601 				 * in the tmap. We do this so when
9602 				 * we walk backwards we include marking
9603 				 * sack-passed on rsm (The one passed in
9604 				 * is skipped since it is generally called
9605 				 * on something sacked before removing it
9606 				 * from the tmap).
9607 				 */
9608 				if (rsm->r_in_tmap) {
9609 					nrsm = TAILQ_NEXT(rsm, r_tnext);
9610 					/*
9611 					 * Now that we have the next
9612 					 * one walk backwards from there.
9613 					 */
9614 					if (nrsm && nrsm->r_in_tmap)
9615 						rack_log_sack_passed(tp, rack, nrsm);
9616 				}
9617 				/* Now are we done? */
9618 				if (SEQ_LT(end, next->r_end) ||
9619 				    (end == next->r_end)) {
9620 					/* Done with block */
9621 					goto out;
9622 				}
9623 				rack_log_map_chg(tp, rack, &stack_map, rsm, next, MAP_SACK_M1, end, __LINE__);
9624 				counter_u64_add(rack_sack_used_next_merge, 1);
9625 				/* Postion for the next block */
9626 				start = next->r_end;
9627 				rsm = tqhash_next(rack->r_ctl.tqh, next);
9628 				if (rsm == NULL)
9629 					goto out;
9630 			} else {
9631 				/**
9632 				 * We can't use any hookery here, so we
9633 				 * need to split the map. We enter like
9634 				 * so:
9635 				 *  rsm      |--------|
9636 				 *  sackblk       |----->
9637 				 * We will add the new block nrsm and
9638 				 * that will be the new portion, and then
9639 				 * fall through after reseting rsm. So we
9640 				 * split and look like this:
9641 				 *  rsm      |----|
9642 				 *  sackblk       |----->
9643 				 *  nrsm          |---|
9644 				 * We then fall through reseting
9645 				 * rsm to nrsm, so the next block
9646 				 * picks it up.
9647 				 */
9648 				nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
9649 				if (nrsm == NULL) {
9650 					/*
9651 					 * failed XXXrrs what can we do but loose the sack
9652 					 * info?
9653 					 */
9654 					goto out;
9655 				}
9656 				counter_u64_add(rack_sack_splits, 1);
9657 				rack_clone_rsm(rack, nrsm, rsm, start);
9658 				moved++;
9659 				rsm->r_just_ret = 0;
9660 #ifndef INVARIANTS
9661 				(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
9662 #else
9663 				if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
9664 					panic("Insert in rb tree of %p fails ret:%d rack:%p rsm:%p",
9665 					      nrsm, insret, rack, rsm);
9666 				}
9667 #endif
9668 				if (rsm->r_in_tmap) {
9669 					TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
9670 					nrsm->r_in_tmap = 1;
9671 				}
9672 				rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SACK_M2, end, __LINE__);
9673 				rsm->r_flags &= (~RACK_HAS_FIN);
9674 				/* Position us to point to the new nrsm that starts the sack blk */
9675 				rsm = nrsm;
9676 			}
9677 		} else {
9678 			/* Already sacked this piece */
9679 			counter_u64_add(rack_sack_skipped_acked, 1);
9680 			moved++;
9681 			if (end == rsm->r_end) {
9682 				/* Done with block */
9683 				rsm = tqhash_next(rack->r_ctl.tqh, rsm);
9684 				goto out;
9685 			} else if (SEQ_LT(end, rsm->r_end)) {
9686 				/* A partial sack to a already sacked block */
9687 				moved++;
9688 				rsm = tqhash_next(rack->r_ctl.tqh, rsm);
9689 				goto out;
9690 			} else {
9691 				/*
9692 				 * The end goes beyond this guy
9693 				 * reposition the start to the
9694 				 * next block.
9695 				 */
9696 				start = rsm->r_end;
9697 				rsm = tqhash_next(rack->r_ctl.tqh, rsm);
9698 				if (rsm == NULL)
9699 					goto out;
9700 			}
9701 		}
9702 	}
9703 	if (SEQ_GEQ(end, rsm->r_end)) {
9704 		/**
9705 		 * The end of this block is either beyond this guy or right
9706 		 * at this guy. I.e.:
9707 		 *  rsm ---                 |-----|
9708 		 *  end                     |-----|
9709 		 *  <or>
9710 		 *  end                     |---------|
9711 		 */
9712 		if ((rsm->r_flags & RACK_ACKED) == 0) {
9713 			/*
9714 			 * Is it a TLP of interest?
9715 			 */
9716 			if ((rsm->r_flags & RACK_TLP) &&
9717 			    (rsm->r_rtr_cnt > 1)) {
9718 				/*
9719 				 * We are splitting a rxt TLP, check
9720 				 * if we need to save off the start/end
9721 				 */
9722 				if (rack->rc_last_tlp_acked_set &&
9723 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
9724 					/*
9725 					 * We already turned this on since we are inside
9726 					 * the previous one was a partially sack now we
9727 					 * are getting another one (maybe all of it).
9728 					 */
9729 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
9730 					/*
9731 					 * Lets make sure we have all of it though.
9732 					 */
9733 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
9734 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9735 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9736 								     rack->r_ctl.last_tlp_acked_end);
9737 					}
9738 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
9739 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9740 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9741 								     rack->r_ctl.last_tlp_acked_end);
9742 					}
9743 				} else {
9744 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9745 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9746 					rack->rc_last_tlp_past_cumack = 0;
9747 					rack->rc_last_tlp_acked_set = 1;
9748 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
9749 				}
9750 			}
9751 			rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
9752 			changed += (rsm->r_end - rsm->r_start);
9753 			/* You get a count for acking a whole segment or more */
9754 			if ((rsm->r_end - rsm->r_start) >= segsiz)
9755 				rack->r_ctl.ack_count += ((rsm->r_end - rsm->r_start) / segsiz);
9756 			rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
9757 			if (rsm->r_in_tmap) /* should be true */
9758 				rack_log_sack_passed(tp, rack, rsm);
9759 			/* Is Reordering occuring? */
9760 			if (rsm->r_flags & RACK_SACK_PASSED) {
9761 				rsm->r_flags &= ~RACK_SACK_PASSED;
9762 				rack->r_ctl.rc_reorder_ts = cts;
9763 				if (rack->r_ctl.rc_reorder_ts == 0)
9764 					rack->r_ctl.rc_reorder_ts = 1;
9765 			}
9766 			if (rack->app_limited_needs_set)
9767 				rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
9768 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
9769 			rsm->r_flags |= RACK_ACKED;
9770 			if (rsm->r_in_tmap) {
9771 				TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
9772 				rsm->r_in_tmap = 0;
9773 			}
9774 			rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_SACK_M3, end, __LINE__);
9775 		} else {
9776 			counter_u64_add(rack_sack_skipped_acked, 1);
9777 			moved++;
9778 		}
9779 		if (end == rsm->r_end) {
9780 			/* This block only - done, setup for next */
9781 			goto out;
9782 		}
9783 		/*
9784 		 * There is more not coverend by this rsm move on
9785 		 * to the next block in the RB tree.
9786 		 */
9787 		nrsm = tqhash_next(rack->r_ctl.tqh, rsm);
9788 		start = rsm->r_end;
9789 		rsm = nrsm;
9790 		if (rsm == NULL)
9791 			goto out;
9792 		goto do_rest_ofb;
9793 	}
9794 	/**
9795 	 * The end of this sack block is smaller than
9796 	 * our rsm i.e.:
9797 	 *  rsm ---                 |-----|
9798 	 *  end                     |--|
9799 	 */
9800 	if ((rsm->r_flags & RACK_ACKED) == 0) {
9801 		/*
9802 		 * Is it a TLP of interest?
9803 		 */
9804 		if ((rsm->r_flags & RACK_TLP) &&
9805 		    (rsm->r_rtr_cnt > 1)) {
9806 			/*
9807 			 * We are splitting a rxt TLP, check
9808 			 * if we need to save off the start/end
9809 			 */
9810 			if (rack->rc_last_tlp_acked_set &&
9811 			    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
9812 				/*
9813 				 * We already turned this on since we are inside
9814 				 * the previous one was a partially sack now we
9815 				 * are getting another one (maybe all of it).
9816 				 */
9817 				rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
9818 				/*
9819 				 * Lets make sure we have all of it though.
9820 				 */
9821 				if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
9822 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9823 					rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9824 							     rack->r_ctl.last_tlp_acked_end);
9825 				}
9826 				if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
9827 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9828 					rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9829 							     rack->r_ctl.last_tlp_acked_end);
9830 				}
9831 			} else {
9832 				rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9833 				rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9834 				rack->rc_last_tlp_past_cumack = 0;
9835 				rack->rc_last_tlp_acked_set = 1;
9836 				rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
9837 			}
9838 		}
9839 		/*
9840 		 * Hookery can only be used if the two entries
9841 		 * are in the same bucket and neither one of
9842 		 * them staddle the bucket line.
9843 		 */
9844 		prev = tqhash_prev(rack->r_ctl.tqh, rsm);
9845 		if (prev &&
9846 		    (rsm->bindex == prev->bindex) &&
9847 		    ((rsm->r_flags & RACK_STRADDLE) == 0) &&
9848 		    ((prev->r_flags & RACK_STRADDLE) == 0) &&
9849 		    (rsm->r_flags & RACK_IN_GP_WIN) &&
9850 		    (prev->r_flags & RACK_IN_GP_WIN))
9851 			can_use_hookery = 1;
9852 		else if (prev &&
9853 			 (rsm->bindex == prev->bindex) &&
9854 			 ((rsm->r_flags & RACK_STRADDLE) == 0) &&
9855 			 ((prev->r_flags & RACK_STRADDLE) == 0) &&
9856 			 ((rsm->r_flags & RACK_IN_GP_WIN) == 0) &&
9857 			 ((prev->r_flags & RACK_IN_GP_WIN) == 0))
9858 			can_use_hookery = 1;
9859 		else
9860 			can_use_hookery = 0;
9861 
9862 		if (prev && can_use_hookery &&
9863 		    (prev->r_flags & RACK_ACKED)) {
9864 			/**
9865 			 * Goal, we want the right remainder of rsm to shrink
9866 			 * in place and span from (rsm->r_start = end) to rsm->r_end.
9867 			 * We want to expand prev to go all the way
9868 			 * to prev->r_end <- end.
9869 			 * so in the tree we have before:
9870 			 *   prev     |--------|         (acked)
9871 			 *   rsm               |-------| (non-acked)
9872 			 *   sackblk           |-|
9873 			 * We churn it so we end up with
9874 			 *   prev     |----------|       (acked)
9875 			 *   rsm                 |-----| (non-acked)
9876 			 *   nrsm              |-| (temporary)
9877 			 *
9878 			 * Note if either prev/rsm is a TLP we don't
9879 			 * do this.
9880 			 */
9881 			noextra++;
9882 			nrsm = &stack_map;
9883 			memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
9884 			prev->r_end = end;
9885 			rsm->r_start = end;
9886 			rsm->r_flags |= RACK_SHUFFLED;
9887 			prev->r_flags |= RACK_SHUFFLED;
9888 			/* Now adjust nrsm (stack copy) to be
9889 			 * the one that is the small
9890 			 * piece that was "sacked".
9891 			 */
9892 			nrsm->r_end = end;
9893 			rsm->r_dupack = 0;
9894 			/*
9895 			 * Which timestamp do we keep? It is rather
9896 			 * important in GP measurements to have the
9897 			 * accurate end of the send window.
9898 			 *
9899 			 * We keep the largest value, which is the newest
9900 			 * send. We do this in case a segment that is
9901 			 * joined together and not part of a GP estimate
9902 			 * later gets expanded into the GP estimate.
9903 			 *
9904 			 * We prohibit the merging of unlike kinds i.e.
9905 			 * all pieces that are in the GP estimate can be
9906 			 * merged and all pieces that are not in a GP estimate
9907 			 * can be merged, but not disimilar pieces. Combine
9908 			 * this with taking the highest here and we should
9909 			 * be ok unless of course the client reneges. Then
9910 			 * all bets are off.
9911 			 */
9912 			if(prev->r_tim_lastsent[(prev->r_rtr_cnt-1)] <
9913 			   nrsm->r_tim_lastsent[(nrsm->r_rtr_cnt-1)]) {
9914 				prev->r_tim_lastsent[(prev->r_rtr_cnt-1)] = nrsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
9915 			}
9916 			/*
9917 			 * And we must keep the newest ack arrival time.
9918 			 */
9919 
9920 			if(prev->r_ack_arrival <
9921 			   rack_to_usec_ts(&rack->r_ctl.act_rcv_time))
9922 				prev->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
9923 
9924 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
9925 			/*
9926 			 * Now that the rsm has had its start moved forward
9927 			 * lets go ahead and get its new place in the world.
9928 			 */
9929 			rack_setup_offset_for_rsm(rack, prev, rsm);
9930 			/*
9931 			 * Now nrsm is our new little piece
9932 			 * that is acked (which was merged
9933 			 * to prev). Update the rtt and changed
9934 			 * based on that. Also check for reordering.
9935 			 */
9936 			rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
9937 			if (rack->app_limited_needs_set)
9938 				rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
9939 			changed += (nrsm->r_end - nrsm->r_start);
9940 			/* You get a count for acking a whole segment or more */
9941 			if ((nrsm->r_end - nrsm->r_start) >= segsiz)
9942 				rack->r_ctl.ack_count += ((nrsm->r_end - nrsm->r_start) / segsiz);
9943 
9944 			rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
9945 			if (nrsm->r_flags & RACK_SACK_PASSED) {
9946 				rack->r_ctl.rc_reorder_ts = cts;
9947 				if (rack->r_ctl.rc_reorder_ts == 0)
9948 					rack->r_ctl.rc_reorder_ts = 1;
9949 			}
9950 			rack_log_map_chg(tp, rack, prev, &stack_map, rsm, MAP_SACK_M4, end, __LINE__);
9951 			rsm = prev;
9952 			counter_u64_add(rack_sack_used_prev_merge, 1);
9953 		} else {
9954 			/**
9955 			 * This is the case where our previous
9956 			 * block is not acked either, so we must
9957 			 * split the block in two.
9958 			 */
9959 			nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
9960 			if (nrsm == NULL) {
9961 				/* failed rrs what can we do but loose the sack info? */
9962 				goto out;
9963 			}
9964 			if ((rsm->r_flags & RACK_TLP) &&
9965 			    (rsm->r_rtr_cnt > 1)) {
9966 				/*
9967 				 * We are splitting a rxt TLP, check
9968 				 * if we need to save off the start/end
9969 				 */
9970 				if (rack->rc_last_tlp_acked_set &&
9971 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
9972 					/*
9973 					 * We already turned this on since this block is inside
9974 					 * the previous one was a partially sack now we
9975 					 * are getting another one (maybe all of it).
9976 					 */
9977 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
9978 					/*
9979 					 * Lets make sure we have all of it though.
9980 					 */
9981 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
9982 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9983 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9984 								     rack->r_ctl.last_tlp_acked_end);
9985 					}
9986 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
9987 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9988 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9989 								     rack->r_ctl.last_tlp_acked_end);
9990 					}
9991 				} else {
9992 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9993 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9994 					rack->rc_last_tlp_acked_set = 1;
9995 					rack->rc_last_tlp_past_cumack = 0;
9996 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
9997 				}
9998 			}
9999 			/**
10000 			 * In this case nrsm becomes
10001 			 * nrsm->r_start = end;
10002 			 * nrsm->r_end = rsm->r_end;
10003 			 * which is un-acked.
10004 			 * <and>
10005 			 * rsm->r_end = nrsm->r_start;
10006 			 * i.e. the remaining un-acked
10007 			 * piece is left on the left
10008 			 * hand side.
10009 			 *
10010 			 * So we start like this
10011 			 * rsm      |----------| (not acked)
10012 			 * sackblk  |---|
10013 			 * build it so we have
10014 			 * rsm      |---|         (acked)
10015 			 * nrsm         |------|  (not acked)
10016 			 */
10017 			counter_u64_add(rack_sack_splits, 1);
10018 			rack_clone_rsm(rack, nrsm, rsm, end);
10019 			moved++;
10020 			rsm->r_flags &= (~RACK_HAS_FIN);
10021 			rsm->r_just_ret = 0;
10022 #ifndef INVARIANTS
10023 			(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
10024 #else
10025 			if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
10026 				panic("Insert in rb tree of %p fails ret:% rack:%p rsm:%p",
10027 				      nrsm, insret, rack, rsm);
10028 			}
10029 #endif
10030 			if (rsm->r_in_tmap) {
10031 				TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
10032 				nrsm->r_in_tmap = 1;
10033 			}
10034 			nrsm->r_dupack = 0;
10035 			rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
10036 			rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
10037 			changed += (rsm->r_end - rsm->r_start);
10038 			/* You get a count for acking a whole segment or more */
10039 			if ((rsm->r_end - rsm->r_start) >= segsiz)
10040 				rack->r_ctl.ack_count += ((rsm->r_end - rsm->r_start) / segsiz);
10041 
10042 			rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
10043 			if (rsm->r_in_tmap) /* should be true */
10044 				rack_log_sack_passed(tp, rack, rsm);
10045 			/* Is Reordering occuring? */
10046 			if (rsm->r_flags & RACK_SACK_PASSED) {
10047 				rsm->r_flags &= ~RACK_SACK_PASSED;
10048 				rack->r_ctl.rc_reorder_ts = cts;
10049 				if (rack->r_ctl.rc_reorder_ts == 0)
10050 					rack->r_ctl.rc_reorder_ts = 1;
10051 			}
10052 			if (rack->app_limited_needs_set)
10053 				rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
10054 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
10055 			rsm->r_flags |= RACK_ACKED;
10056 			rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SACK_M5, end, __LINE__);
10057 			if (rsm->r_in_tmap) {
10058 				TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
10059 				rsm->r_in_tmap = 0;
10060 			}
10061 		}
10062 	} else if (start != end){
10063 		/*
10064 		 * The block was already acked.
10065 		 */
10066 		counter_u64_add(rack_sack_skipped_acked, 1);
10067 		moved++;
10068 	}
10069 out:
10070 	if (rsm &&
10071 	    ((rsm->r_flags & RACK_TLP) == 0) &&
10072 	    (rsm->r_flags & RACK_ACKED)) {
10073 		/*
10074 		 * Now can we merge where we worked
10075 		 * with either the previous or
10076 		 * next block?
10077 		 */
10078 		next = tqhash_next(rack->r_ctl.tqh, rsm);
10079 		while (next) {
10080 			if (next->r_flags & RACK_TLP)
10081 				break;
10082 			/* Only allow merges between ones in or out of GP window */
10083 			if ((next->r_flags & RACK_IN_GP_WIN) &&
10084 			    ((rsm->r_flags & RACK_IN_GP_WIN) == 0)) {
10085 				break;
10086 			}
10087 			if ((rsm->r_flags & RACK_IN_GP_WIN) &&
10088 			    ((next->r_flags & RACK_IN_GP_WIN) == 0)) {
10089 				break;
10090 			}
10091 			if (rsm->bindex != next->bindex)
10092 				break;
10093 			if (rsm->r_flags & RACK_STRADDLE)
10094 				break;
10095 			if (next->r_flags & RACK_STRADDLE)
10096 				break;
10097 			if (next->r_flags & RACK_ACKED) {
10098 				/* yep this and next can be merged */
10099 				rsm = rack_merge_rsm(rack, rsm, next);
10100 				noextra++;
10101 				next = tqhash_next(rack->r_ctl.tqh, rsm);
10102 			} else
10103 				break;
10104 		}
10105 		/* Now what about the previous? */
10106 		prev = tqhash_prev(rack->r_ctl.tqh, rsm);
10107 		while (prev) {
10108 			if (prev->r_flags & RACK_TLP)
10109 				break;
10110 			/* Only allow merges between ones in or out of GP window */
10111 			if ((prev->r_flags & RACK_IN_GP_WIN) &&
10112 			    ((rsm->r_flags & RACK_IN_GP_WIN) == 0)) {
10113 				break;
10114 			}
10115 			if ((rsm->r_flags & RACK_IN_GP_WIN) &&
10116 			    ((prev->r_flags & RACK_IN_GP_WIN) == 0)) {
10117 				break;
10118 			}
10119 			if (rsm->bindex != prev->bindex)
10120 				break;
10121 			if (rsm->r_flags & RACK_STRADDLE)
10122 				break;
10123 			if (prev->r_flags & RACK_STRADDLE)
10124 				break;
10125 			if (prev->r_flags & RACK_ACKED) {
10126 				/* yep the previous and this can be merged */
10127 				rsm = rack_merge_rsm(rack, prev, rsm);
10128 				noextra++;
10129 				prev = tqhash_prev(rack->r_ctl.tqh, rsm);
10130 			} else
10131 				break;
10132 		}
10133 	}
10134 	if (used_ref == 0) {
10135 		counter_u64_add(rack_sack_proc_all, 1);
10136 	} else {
10137 		counter_u64_add(rack_sack_proc_short, 1);
10138 	}
10139 	/* Save off the next one for quick reference. */
10140 	nrsm = tqhash_find(rack->r_ctl.tqh, end);
10141 	*prsm = rack->r_ctl.rc_sacklast = nrsm;
10142 	/* Pass back the moved. */
10143 	*moved_two = moved;
10144 	*no_extra = noextra;
10145 	return (changed);
10146 }
10147 
10148 static void inline
10149 rack_peer_reneges(struct tcp_rack *rack, struct rack_sendmap *rsm, tcp_seq th_ack)
10150 {
10151 	struct rack_sendmap *tmap;
10152 
10153 	tmap = NULL;
10154 	while (rsm && (rsm->r_flags & RACK_ACKED)) {
10155 		/* Its no longer sacked, mark it so */
10156 		rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
10157 #ifdef INVARIANTS
10158 		if (rsm->r_in_tmap) {
10159 			panic("rack:%p rsm:%p flags:0x%x in tmap?",
10160 			      rack, rsm, rsm->r_flags);
10161 		}
10162 #endif
10163 		rsm->r_flags &= ~(RACK_ACKED|RACK_SACK_PASSED|RACK_WAS_SACKPASS);
10164 		/* Rebuild it into our tmap */
10165 		if (tmap == NULL) {
10166 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
10167 			tmap = rsm;
10168 		} else {
10169 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, tmap, rsm, r_tnext);
10170 			tmap = rsm;
10171 		}
10172 		tmap->r_in_tmap = 1;
10173 		rsm = tqhash_next(rack->r_ctl.tqh, rsm);
10174 	}
10175 	/*
10176 	 * Now lets possibly clear the sack filter so we start
10177 	 * recognizing sacks that cover this area.
10178 	 */
10179 	sack_filter_clear(&rack->r_ctl.rack_sf, th_ack);
10180 
10181 }
10182 
10183 static void
10184 rack_do_decay(struct tcp_rack *rack)
10185 {
10186 	struct timeval res;
10187 
10188 #define	timersub(tvp, uvp, vvp)						\
10189 	do {								\
10190 		(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;		\
10191 		(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;	\
10192 		if ((vvp)->tv_usec < 0) {				\
10193 			(vvp)->tv_sec--;				\
10194 			(vvp)->tv_usec += 1000000;			\
10195 		}							\
10196 	} while (0)
10197 
10198 	timersub(&rack->r_ctl.act_rcv_time, &rack->r_ctl.rc_last_time_decay, &res);
10199 #undef timersub
10200 
10201 	rack->r_ctl.input_pkt++;
10202 	if ((rack->rc_in_persist) ||
10203 	    (res.tv_sec >= 1) ||
10204 	    (rack->rc_tp->snd_max == rack->rc_tp->snd_una)) {
10205 		/*
10206 		 * Check for decay of non-SAD,
10207 		 * we want all SAD detection metrics to
10208 		 * decay 1/4 per second (or more) passed.
10209 		 * Current default is 800 so it decays
10210 		 * 80% every second.
10211 		 */
10212 #ifdef TCP_SAD_DETECTION
10213 		uint32_t pkt_delta;
10214 
10215 		pkt_delta = rack->r_ctl.input_pkt - rack->r_ctl.saved_input_pkt;
10216 #endif
10217 		/* Update our saved tracking values */
10218 		rack->r_ctl.saved_input_pkt = rack->r_ctl.input_pkt;
10219 		rack->r_ctl.rc_last_time_decay = rack->r_ctl.act_rcv_time;
10220 		/* Now do we escape without decay? */
10221 #ifdef TCP_SAD_DETECTION
10222 		if (rack->rc_in_persist ||
10223 		    (rack->rc_tp->snd_max == rack->rc_tp->snd_una) ||
10224 		    (pkt_delta < tcp_sad_low_pps)){
10225 			/*
10226 			 * We don't decay idle connections
10227 			 * or ones that have a low input pps.
10228 			 */
10229 			return;
10230 		}
10231 		/* Decay the counters */
10232 		rack->r_ctl.ack_count = ctf_decay_count(rack->r_ctl.ack_count,
10233 							tcp_sad_decay_val);
10234 		rack->r_ctl.sack_count = ctf_decay_count(rack->r_ctl.sack_count,
10235 							 tcp_sad_decay_val);
10236 		rack->r_ctl.sack_moved_extra = ctf_decay_count(rack->r_ctl.sack_moved_extra,
10237 							       tcp_sad_decay_val);
10238 		rack->r_ctl.sack_noextra_move = ctf_decay_count(rack->r_ctl.sack_noextra_move,
10239 								tcp_sad_decay_val);
10240 #endif
10241 	}
10242 }
10243 
10244 static void inline
10245 rack_rsm_sender_update(struct tcp_rack *rack, struct tcpcb *tp, struct rack_sendmap *rsm, uint8_t from)
10246 {
10247 	/*
10248 	 * We look at advancing the end send time for our GP
10249 	 * measurement tracking only as the cumulative acknowledgment
10250 	 * moves forward. You might wonder about this, why not
10251 	 * at every transmission or retransmission within the
10252 	 * GP window update the rc_gp_cumack_ts? Well its rather
10253 	 * nuanced but basically the GP window *may* expand (as
10254 	 * it does below) or worse and harder to track it may shrink.
10255 	 *
10256 	 * This last makes it impossible to track at the time of
10257 	 * the send, since you may set forward your rc_gp_cumack_ts
10258 	 * when you send, because that send *is* in your currently
10259 	 * "guessed" window, but then it shrinks. Now which was
10260 	 * the send time of the last bytes in the window, by the
10261 	 * time you ask that question that part of the sendmap
10262 	 * is freed. So you don't know and you will have too
10263 	 * long of send window. Instead by updating the time
10264 	 * marker only when the cumack advances this assures us
10265 	 * that we will have only the sends in the window of our
10266 	 * GP measurement.
10267 	 *
10268 	 * Another complication from this is the
10269 	 * merging of sendmap entries. During SACK processing this
10270 	 * can happen to conserve the sendmap size. That breaks
10271 	 * everything down in tracking the send window of the GP
10272 	 * estimate. So to prevent that and keep it working with
10273 	 * a tiny bit more limited merging, we only allow like
10274 	 * types to be merged. I.e. if two sends are in the GP window
10275 	 * then its ok to merge them together. If two sends are not
10276 	 * in the GP window its ok to merge them together too. Though
10277 	 * one send in and one send out cannot be merged. We combine
10278 	 * this with never allowing the shrinking of the GP window when
10279 	 * we are in recovery so that we can properly calculate the
10280 	 * sending times.
10281 	 *
10282 	 * This all of course seems complicated, because it is.. :)
10283 	 *
10284 	 * The cum-ack is being advanced upon the sendmap.
10285 	 * If we are not doing a GP estimate don't
10286 	 * proceed.
10287 	 */
10288 	uint64_t ts;
10289 
10290 	if ((tp->t_flags & TF_GPUTINPROG) == 0)
10291 		return;
10292 	/*
10293 	 * If this sendmap entry is going
10294 	 * beyond the measurement window we had picked,
10295 	 * expand the measurement window by that much.
10296 	 */
10297 	if (SEQ_GT(rsm->r_end, tp->gput_ack)) {
10298 		tp->gput_ack = rsm->r_end;
10299 	}
10300 	/*
10301 	 * If we have not setup a ack, then we
10302 	 * have no idea if the newly acked pieces
10303 	 * will be "in our seq measurement range". If
10304 	 * it is when we clear the app_limited_needs_set
10305 	 * flag the timestamp will be updated.
10306 	 */
10307 	if (rack->app_limited_needs_set)
10308 		return;
10309 	/*
10310 	 * Finally, we grab out the latest timestamp
10311 	 * that this packet was sent and then see
10312 	 * if:
10313 	 *  a) The packet touches are newly defined GP range.
10314 	 *  b) The time is greater than (newer) than the
10315 	 *     one we currently have. If so we update
10316 	 *     our sending end time window.
10317 	 *
10318 	 * Note we *do not* do this at send time. The reason
10319 	 * is that if you do you *may* pick up a newer timestamp
10320 	 * for a range you are not going to measure. We project
10321 	 * out how far and then sometimes modify that to be
10322 	 * smaller. If that occurs then you will have a send
10323 	 * that does not belong to the range included.
10324 	 */
10325 	if ((ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]) <=
10326 	    rack->r_ctl.rc_gp_cumack_ts)
10327 		return;
10328 	if (rack_in_gp_window(tp, rsm)) {
10329 		rack->r_ctl.rc_gp_cumack_ts = ts;
10330 		rack_log_gpset(rack, tp->gput_ack, (uint32_t)ts, rsm->r_end,
10331 			       __LINE__, from, rsm);
10332 	}
10333 }
10334 
10335 static void
10336 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)
10337 {
10338 	struct rack_sendmap *rsm;
10339 	/*
10340 	 * The ACK point is advancing to th_ack, we must drop off
10341 	 * the packets in the rack log and calculate any eligble
10342 	 * RTT's.
10343 	 */
10344 
10345 	rack->r_wanted_output = 1;
10346 	if (SEQ_GT(th_ack, tp->snd_una))
10347 	    rack->r_ctl.last_cumack_advance = acktime;
10348 
10349 	/* Tend any TLP that has been marked for 1/2 the seq space (its old)  */
10350 	if ((rack->rc_last_tlp_acked_set == 1)&&
10351 	    (rack->rc_last_tlp_past_cumack == 1) &&
10352 	    (SEQ_GT(rack->r_ctl.last_tlp_acked_start, th_ack))) {
10353 		/*
10354 		 * We have reached the point where our last rack
10355 		 * tlp retransmit sequence is ahead of the cum-ack.
10356 		 * This can only happen when the cum-ack moves all
10357 		 * the way around (its been a full 2^^31+1 bytes
10358 		 * or more since we sent a retransmitted TLP). Lets
10359 		 * turn off the valid flag since its not really valid.
10360 		 *
10361 		 * Note since sack's also turn on this event we have
10362 		 * a complication, we have to wait to age it out until
10363 		 * the cum-ack is by the TLP before checking which is
10364 		 * what the next else clause does.
10365 		 */
10366 		rack_log_dsack_event(rack, 9, __LINE__,
10367 				     rack->r_ctl.last_tlp_acked_start,
10368 				     rack->r_ctl.last_tlp_acked_end);
10369 		rack->rc_last_tlp_acked_set = 0;
10370 		rack->rc_last_tlp_past_cumack = 0;
10371 	} else if ((rack->rc_last_tlp_acked_set == 1) &&
10372 		   (rack->rc_last_tlp_past_cumack == 0) &&
10373 		   (SEQ_GEQ(th_ack, rack->r_ctl.last_tlp_acked_end))) {
10374 		/*
10375 		 * It is safe to start aging TLP's out.
10376 		 */
10377 		rack->rc_last_tlp_past_cumack = 1;
10378 	}
10379 	/* We do the same for the tlp send seq as well */
10380 	if ((rack->rc_last_sent_tlp_seq_valid == 1) &&
10381 	    (rack->rc_last_sent_tlp_past_cumack == 1) &&
10382 	    (SEQ_GT(rack->r_ctl.last_sent_tlp_seq,  th_ack))) {
10383 		rack_log_dsack_event(rack, 9, __LINE__,
10384 				     rack->r_ctl.last_sent_tlp_seq,
10385 				     (rack->r_ctl.last_sent_tlp_seq +
10386 				      rack->r_ctl.last_sent_tlp_len));
10387 		rack->rc_last_sent_tlp_seq_valid = 0;
10388 		rack->rc_last_sent_tlp_past_cumack = 0;
10389 	} else if ((rack->rc_last_sent_tlp_seq_valid == 1) &&
10390 		   (rack->rc_last_sent_tlp_past_cumack == 0) &&
10391 		   (SEQ_GEQ(th_ack, rack->r_ctl.last_sent_tlp_seq))) {
10392 		/*
10393 		 * It is safe to start aging TLP's send.
10394 		 */
10395 		rack->rc_last_sent_tlp_past_cumack = 1;
10396 	}
10397 more:
10398 	rsm = tqhash_min(rack->r_ctl.tqh);
10399 	if (rsm == NULL) {
10400 		if ((th_ack - 1) == tp->iss) {
10401 			/*
10402 			 * For the SYN incoming case we will not
10403 			 * have called tcp_output for the sending of
10404 			 * the SYN, so there will be no map. All
10405 			 * other cases should probably be a panic.
10406 			 */
10407 			return;
10408 		}
10409 		if (tp->t_flags & TF_SENTFIN) {
10410 			/* if we sent a FIN we often will not have map */
10411 			return;
10412 		}
10413 #ifdef INVARIANTS
10414 		panic("No rack map tp:%p for state:%d ack:%u rack:%p snd_una:%u snd_max:%u snd_nxt:%u\n",
10415 		      tp,
10416 		      tp->t_state, th_ack, rack,
10417 		      tp->snd_una, tp->snd_max, tp->snd_nxt);
10418 #endif
10419 		return;
10420 	}
10421 	if (SEQ_LT(th_ack, rsm->r_start)) {
10422 		/* Huh map is missing this */
10423 #ifdef INVARIANTS
10424 		printf("Rack map starts at r_start:%u for th_ack:%u huh? ts:%d rs:%d\n",
10425 		       rsm->r_start,
10426 		       th_ack, tp->t_state, rack->r_state);
10427 #endif
10428 		return;
10429 	}
10430 	rack_update_rtt(tp, rack, rsm, to, cts, CUM_ACKED, th_ack);
10431 
10432 	/* Now was it a retransmitted TLP? */
10433 	if ((rsm->r_flags & RACK_TLP) &&
10434 	    (rsm->r_rtr_cnt > 1)) {
10435 		/*
10436 		 * Yes, this rsm was a TLP and retransmitted, remember that
10437 		 * since if a DSACK comes back on this we don't want
10438 		 * to think of it as a reordered segment. This may
10439 		 * get updated again with possibly even other TLPs
10440 		 * in flight, but thats ok. Only when we don't send
10441 		 * a retransmitted TLP for 1/2 the sequences space
10442 		 * will it get turned off (above).
10443 		 */
10444 		if (rack->rc_last_tlp_acked_set &&
10445 		    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
10446 			/*
10447 			 * We already turned this on since the end matches,
10448 			 * the previous one was a partially ack now we
10449 			 * are getting another one (maybe all of it).
10450 			 */
10451 			rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
10452 			/*
10453 			 * Lets make sure we have all of it though.
10454 			 */
10455 			if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
10456 				rack->r_ctl.last_tlp_acked_start = rsm->r_start;
10457 				rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
10458 						     rack->r_ctl.last_tlp_acked_end);
10459 			}
10460 			if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
10461 				rack->r_ctl.last_tlp_acked_end = rsm->r_end;
10462 				rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
10463 						     rack->r_ctl.last_tlp_acked_end);
10464 			}
10465 		} else {
10466 			rack->rc_last_tlp_past_cumack = 1;
10467 			rack->r_ctl.last_tlp_acked_start = rsm->r_start;
10468 			rack->r_ctl.last_tlp_acked_end = rsm->r_end;
10469 			rack->rc_last_tlp_acked_set = 1;
10470 			rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
10471 		}
10472 	}
10473 	/* Now do we consume the whole thing? */
10474 	if (SEQ_GEQ(th_ack, rsm->r_end)) {
10475 		/* Its all consumed. */
10476 		uint32_t left;
10477 		uint8_t newly_acked;
10478 
10479 		rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_FREE, rsm->r_end, __LINE__);
10480 		rack->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
10481 		rsm->r_rtr_bytes = 0;
10482 		/*
10483 		 * Record the time of highest cumack sent if its in our measurement
10484 		 * window and possibly bump out the end.
10485 		 */
10486 		rack_rsm_sender_update(rack, tp, rsm, 4);
10487 		tqhash_remove(rack->r_ctl.tqh, rsm, REMOVE_TYPE_CUMACK);
10488 		if (rsm->r_in_tmap) {
10489 			TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
10490 			rsm->r_in_tmap = 0;
10491 		}
10492 		newly_acked = 1;
10493 		if (rsm->r_flags & RACK_ACKED) {
10494 			/*
10495 			 * It was acked on the scoreboard -- remove
10496 			 * it from total
10497 			 */
10498 			rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
10499 			newly_acked = 0;
10500 		} else if (rsm->r_flags & RACK_SACK_PASSED) {
10501 			/*
10502 			 * There are segments ACKED on the
10503 			 * scoreboard further up. We are seeing
10504 			 * reordering.
10505 			 */
10506 			rsm->r_flags &= ~RACK_SACK_PASSED;
10507 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
10508 			rsm->r_flags |= RACK_ACKED;
10509 			rack->r_ctl.rc_reorder_ts = cts;
10510 			if (rack->r_ctl.rc_reorder_ts == 0)
10511 				rack->r_ctl.rc_reorder_ts = 1;
10512 			if (rack->r_ent_rec_ns) {
10513 				/*
10514 				 * We have sent no more, and we saw an sack
10515 				 * then ack arrive.
10516 				 */
10517 				rack->r_might_revert = 1;
10518 			}
10519 		}
10520 		if ((rsm->r_flags & RACK_TO_REXT) &&
10521 		    (tp->t_flags & TF_RCVD_TSTMP) &&
10522 		    (to->to_flags & TOF_TS) &&
10523 		    (to->to_tsecr != 0) &&
10524 		    (tp->t_flags & TF_PREVVALID)) {
10525 			/*
10526 			 * We can use the timestamp to see
10527 			 * if this retransmission was from the
10528 			 * first transmit. If so we made a mistake.
10529 			 */
10530 			tp->t_flags &= ~TF_PREVVALID;
10531 			if (to->to_tsecr == rack_ts_to_msec(rsm->r_tim_lastsent[0])) {
10532 				/* The first transmit is what this ack is for */
10533 				rack_cong_signal(tp, CC_RTO_ERR, th_ack, __LINE__);
10534 			}
10535 		}
10536 		left = th_ack - rsm->r_end;
10537 		if (rack->app_limited_needs_set && newly_acked)
10538 			rack_need_set_test(tp, rack, rsm, th_ack, __LINE__, RACK_USE_END_OR_THACK);
10539 		/* Free back to zone */
10540 		rack_free(rack, rsm);
10541 		if (left) {
10542 			goto more;
10543 		}
10544 		/* Check for reneging */
10545 		rsm = tqhash_min(rack->r_ctl.tqh);
10546 		if (rsm && (rsm->r_flags & RACK_ACKED) && (th_ack == rsm->r_start)) {
10547 			/*
10548 			 * The peer has moved snd_una up to
10549 			 * the edge of this send, i.e. one
10550 			 * that it had previously acked. The only
10551 			 * way that can be true if the peer threw
10552 			 * away data (space issues) that it had
10553 			 * previously sacked (else it would have
10554 			 * given us snd_una up to (rsm->r_end).
10555 			 * We need to undo the acked markings here.
10556 			 *
10557 			 * Note we have to look to make sure th_ack is
10558 			 * our rsm->r_start in case we get an old ack
10559 			 * where th_ack is behind snd_una.
10560 			 */
10561 			rack_peer_reneges(rack, rsm, th_ack);
10562 		}
10563 		return;
10564 	}
10565 	if (rsm->r_flags & RACK_ACKED) {
10566 		/*
10567 		 * It was acked on the scoreboard -- remove it from
10568 		 * total for the part being cum-acked.
10569 		 */
10570 		rack->r_ctl.rc_sacked -= (th_ack - rsm->r_start);
10571 	}
10572 	/*
10573 	 * Clear the dup ack count for
10574 	 * the piece that remains.
10575 	 */
10576 	rsm->r_dupack = 0;
10577 	rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
10578 	if (rsm->r_rtr_bytes) {
10579 		/*
10580 		 * It was retransmitted adjust the
10581 		 * sack holes for what was acked.
10582 		 */
10583 		int ack_am;
10584 
10585 		ack_am = (th_ack - rsm->r_start);
10586 		if (ack_am >= rsm->r_rtr_bytes) {
10587 			rack->r_ctl.rc_holes_rxt -= ack_am;
10588 			rsm->r_rtr_bytes -= ack_am;
10589 		}
10590 	}
10591 	/*
10592 	 * Update where the piece starts and record
10593 	 * the time of send of highest cumack sent if
10594 	 * its in our GP range.
10595 	 */
10596 	rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_TRIM_HEAD, th_ack, __LINE__);
10597 	/* Now we need to move our offset forward too */
10598 	if (rsm->m &&
10599 	    ((rsm->orig_m_len != rsm->m->m_len) ||
10600 	     (M_TRAILINGROOM(rsm->m) != rsm->orig_t_space))) {
10601 		/* Fix up the orig_m_len and possibly the mbuf offset */
10602 		rack_adjust_orig_mlen(rsm);
10603 	}
10604 	rsm->soff += (th_ack - rsm->r_start);
10605 	rack_rsm_sender_update(rack, tp, rsm, 5);
10606 	/* The trim will move th_ack into r_start for us */
10607 	tqhash_trim(rack->r_ctl.tqh, th_ack);
10608 	/* Now do we need to move the mbuf fwd too? */
10609 	if (rsm->m) {
10610 		while (rsm->soff >= rsm->m->m_len) {
10611 			rsm->soff -= rsm->m->m_len;
10612 			rsm->m = rsm->m->m_next;
10613 			KASSERT((rsm->m != NULL),
10614 				(" nrsm:%p hit at soff:%u null m",
10615 				 rsm, rsm->soff));
10616 		}
10617 		rsm->orig_m_len = rsm->m->m_len;
10618 		rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
10619 	}
10620 	if (rack->app_limited_needs_set &&
10621 	    SEQ_GEQ(th_ack, tp->gput_seq))
10622 		rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_BEG);
10623 }
10624 
10625 static void
10626 rack_handle_might_revert(struct tcpcb *tp, struct tcp_rack *rack)
10627 {
10628 	struct rack_sendmap *rsm;
10629 	int sack_pass_fnd = 0;
10630 
10631 	if (rack->r_might_revert) {
10632 		/*
10633 		 * Ok we have reordering, have not sent anything, we
10634 		 * might want to revert the congestion state if nothing
10635 		 * further has SACK_PASSED on it. Lets check.
10636 		 *
10637 		 * We also get here when we have DSACKs come in for
10638 		 * all the data that we FR'd. Note that a rxt or tlp
10639 		 * timer clears this from happening.
10640 		 */
10641 
10642 		TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
10643 			if (rsm->r_flags & RACK_SACK_PASSED) {
10644 				sack_pass_fnd = 1;
10645 				break;
10646 			}
10647 		}
10648 		if (sack_pass_fnd == 0) {
10649 			/*
10650 			 * We went into recovery
10651 			 * incorrectly due to reordering!
10652 			 */
10653 			int orig_cwnd;
10654 
10655 			rack->r_ent_rec_ns = 0;
10656 			orig_cwnd = tp->snd_cwnd;
10657 			tp->snd_ssthresh = rack->r_ctl.rc_ssthresh_at_erec;
10658 			tp->snd_recover = tp->snd_una;
10659 			rack_log_to_prr(rack, 14, orig_cwnd, __LINE__);
10660 			EXIT_RECOVERY(tp->t_flags);
10661 		}
10662 		rack->r_might_revert = 0;
10663 	}
10664 }
10665 
10666 #ifdef TCP_SAD_DETECTION
10667 
10668 static void
10669 rack_merge_out_sacks(struct tcp_rack *rack)
10670 {
10671 	struct rack_sendmap *cur, *next, *rsm, *trsm = NULL;
10672 
10673 	cur = tqhash_min(rack->r_ctl.tqh);
10674 	while(cur) {
10675 		next = tqhash_next(rack->r_ctl.tqh, cur);
10676 		/*
10677 		 * The idea is to go through all and merge back
10678 		 * together the pieces sent together,
10679 		 */
10680 		if ((next != NULL) &&
10681 		    (cur->r_tim_lastsent[0] == next->r_tim_lastsent[0])) {
10682 			rack_merge_rsm(rack, cur, next);
10683 		} else {
10684 			cur = next;
10685 		}
10686 	}
10687 	/*
10688 	 * now treat it like a rxt event, everything is outstanding
10689 	 * and sent nothing acvked and dupacks are all zero. If this
10690 	 * is not an attacker it will have to dupack its way through
10691 	 * it all.
10692 	 */
10693 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
10694 	TQHASH_FOREACH(rsm, rack->r_ctl.tqh)  {
10695 		rsm->r_dupack = 0;
10696 		/* We must re-add it back to the tlist */
10697 		if (trsm == NULL) {
10698 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
10699 		} else {
10700 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, trsm, rsm, r_tnext);
10701 		}
10702 		rsm->r_in_tmap = 1;
10703 		trsm = rsm;
10704 		rsm->r_flags &= ~(RACK_ACKED | RACK_SACK_PASSED | RACK_WAS_SACKPASS | RACK_RWND_COLLAPSED);
10705 	}
10706 	sack_filter_clear(&rack->r_ctl.rack_sf, rack->rc_tp->snd_una);
10707 }
10708 
10709 static void
10710 rack_do_detection(struct tcpcb *tp, struct tcp_rack *rack,  uint32_t bytes_this_ack, uint32_t segsiz)
10711 {
10712 	int do_detection = 0;
10713 
10714 	if (rack->sack_attack_disable || rack->rc_suspicious) {
10715 		/*
10716 		 * If we have been disabled we must detect
10717 		 * to possibly reverse it. Or if the guy has
10718 		 * sent in suspicious sacks we want to do detection too.
10719 		 */
10720 		do_detection = 1;
10721 
10722 	} else if  ((rack->do_detection || tcp_force_detection) &&
10723 		    (tcp_sack_to_ack_thresh > 0) &&
10724 		    (tcp_sack_to_move_thresh > 0) &&
10725 		    (rack->r_ctl.rc_num_maps_alloced > tcp_map_minimum)) {
10726 		/*
10727 		 * We only detect here if:
10728 		 * 1) System wide forcing is on <or> do_detection is on
10729 		 *   <and>
10730 		 * 2) We have thresholds for move and ack (set one to 0 and we are off)
10731 		 *   <and>
10732 		 * 3) We have maps allocated larger than our min (500).
10733 		 */
10734 		do_detection = 1;
10735 	}
10736 	if (do_detection > 0) {
10737 		/*
10738 		 * We have thresholds set to find
10739 		 * possible attackers and disable sack.
10740 		 * Check them.
10741 		 */
10742 		uint64_t ackratio, moveratio, movetotal;
10743 
10744 		/* Log detecting */
10745 		rack_log_sad(rack, 1);
10746 		/* Do we establish a ack ratio */
10747 		if ((rack->r_ctl.sack_count > tcp_map_minimum)  ||
10748 		    (rack->rc_suspicious == 1) ||
10749 		    (rack->sack_attack_disable > 0)) {
10750 			ackratio = (uint64_t)(rack->r_ctl.sack_count);
10751 			ackratio *= (uint64_t)(1000);
10752 			if (rack->r_ctl.ack_count)
10753 				ackratio /= (uint64_t)(rack->r_ctl.ack_count);
10754 			else {
10755 				/* We can hit this due to ack totals degregation (via small sacks) */
10756 				ackratio = 1000;
10757 			}
10758 		} else {
10759 			/*
10760 			 * No ack ratio needed if we have not
10761 			 * seen more sacks then the number of map entries.
10762 			 * The exception to that is if we have disabled sack then
10763 			 * we need to find a ratio.
10764 			 */
10765 			ackratio = 0;
10766 		}
10767 
10768 		if ((rack->sack_attack_disable == 0) &&
10769 		    (ackratio > rack_highest_sack_thresh_seen))
10770 			rack_highest_sack_thresh_seen = (uint32_t)ackratio;
10771 		/* Do we establish a move ratio? */
10772 		if ((rack->r_ctl.sack_moved_extra > tcp_map_minimum) ||
10773 		    (rack->rc_suspicious == 1) ||
10774 		    (rack->sack_attack_disable > 0)) {
10775 			/*
10776 			 * We need to have more sack moves than maps
10777 			 * allocated to have a move ratio considered.
10778 			 */
10779 			movetotal = rack->r_ctl.sack_moved_extra;
10780 			movetotal += rack->r_ctl.sack_noextra_move;
10781 			moveratio = rack->r_ctl.sack_moved_extra;
10782 			moveratio *= (uint64_t)1000;
10783 			if (movetotal)
10784 				moveratio /= movetotal;
10785 			else {
10786 				/* No moves, thats pretty good */
10787 				moveratio = 0;
10788 			}
10789 		} else {
10790 			/*
10791 			 * Not enough moves have occured to consider
10792 			 * if we are out of whack in that ratio.
10793 			 * The exception to that is if we have disabled sack then
10794 			 * we need to find a ratio.
10795 			 */
10796 			moveratio = 0;
10797 		}
10798 		if ((rack->sack_attack_disable == 0) &&
10799 		    (moveratio > rack_highest_move_thresh_seen))
10800 			rack_highest_move_thresh_seen = (uint32_t)moveratio;
10801 		/* Now the tests */
10802 		if (rack->sack_attack_disable == 0) {
10803 			/* Not disabled, do we need to disable? */
10804 			if ((ackratio > tcp_sack_to_ack_thresh) &&
10805 			    (moveratio > tcp_sack_to_move_thresh)) {
10806 				/* Disable sack processing */
10807 				tcp_trace_point(rack->rc_tp, TCP_TP_SAD_TRIGGERED);
10808 				rack->sack_attack_disable = 1;
10809 				/* set it so we have the built in delay */
10810 				rack->r_ctl.ack_during_sd = 1;
10811 				if (rack_merge_out_sacks_on_attack)
10812 					rack_merge_out_sacks(rack);
10813 				counter_u64_add(rack_sack_attacks_detected, 1);
10814 				tcp_trace_point(rack->rc_tp, TCP_TP_SAD_TRIGGERED);
10815 				/* Clamp the cwnd at flight size */
10816 				rack->r_ctl.rc_saved_cwnd = rack->rc_tp->snd_cwnd;
10817 				rack->rc_tp->snd_cwnd = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
10818 				rack_log_sad(rack, 2);
10819 			}
10820 		} else {
10821 			/* We are sack-disabled check for false positives */
10822 			if ((ackratio <= tcp_restoral_thresh) ||
10823 			    ((rack_merge_out_sacks_on_attack == 0) &&
10824 			     (rack->rc_suspicious == 0) &&
10825 			     (rack->r_ctl.rc_num_maps_alloced <= (tcp_map_minimum/2)))) {
10826 				rack->sack_attack_disable = 0;
10827 				rack_log_sad(rack, 3);
10828 				/* Restart counting */
10829 				rack->r_ctl.sack_count = 0;
10830 				rack->r_ctl.sack_moved_extra = 0;
10831 				rack->r_ctl.sack_noextra_move = 1;
10832 				rack->rc_suspicious = 0;
10833 				rack->r_ctl.ack_count = max(1,
10834 							    (bytes_this_ack / segsiz));
10835 
10836 				counter_u64_add(rack_sack_attacks_reversed, 1);
10837 				/* Restore the cwnd */
10838 				if (rack->r_ctl.rc_saved_cwnd > rack->rc_tp->snd_cwnd)
10839 					rack->rc_tp->snd_cwnd = rack->r_ctl.rc_saved_cwnd;
10840 			}
10841 		}
10842 	}
10843 }
10844 #endif
10845 
10846 static int
10847 rack_note_dsack(struct tcp_rack *rack, tcp_seq start, tcp_seq end)
10848 {
10849 
10850 	uint32_t am, l_end;
10851 	int was_tlp = 0;
10852 
10853 	if (SEQ_GT(end, start))
10854 		am = end - start;
10855 	else
10856 		am = 0;
10857 	if ((rack->rc_last_tlp_acked_set ) &&
10858 	    (SEQ_GEQ(start, rack->r_ctl.last_tlp_acked_start)) &&
10859 	    (SEQ_LEQ(end, rack->r_ctl.last_tlp_acked_end))) {
10860 		/*
10861 		 * The DSACK is because of a TLP which we don't
10862 		 * do anything with the reordering window over since
10863 		 * it was not reordering that caused the DSACK but
10864 		 * our previous retransmit TLP.
10865 		 */
10866 		rack_log_dsack_event(rack, 7, __LINE__, start, end);
10867 		was_tlp = 1;
10868 		goto skip_dsack_round;
10869 	}
10870 	if (rack->rc_last_sent_tlp_seq_valid) {
10871 		l_end = rack->r_ctl.last_sent_tlp_seq + rack->r_ctl.last_sent_tlp_len;
10872 		if (SEQ_GEQ(start, rack->r_ctl.last_sent_tlp_seq) &&
10873 		    (SEQ_LEQ(end, l_end))) {
10874 			/*
10875 			 * This dsack is from the last sent TLP, ignore it
10876 			 * for reordering purposes.
10877 			 */
10878 			rack_log_dsack_event(rack, 7, __LINE__, start, end);
10879 			was_tlp = 1;
10880 			goto skip_dsack_round;
10881 		}
10882 	}
10883 	if (rack->rc_dsack_round_seen == 0) {
10884 		rack->rc_dsack_round_seen = 1;
10885 		rack->r_ctl.dsack_round_end = rack->rc_tp->snd_max;
10886 		rack->r_ctl.num_dsack++;
10887 		rack->r_ctl.dsack_persist = 16;	/* 16 is from the standard */
10888 		rack_log_dsack_event(rack, 2, __LINE__, 0, 0);
10889 	}
10890 skip_dsack_round:
10891 	/*
10892 	 * We keep track of how many DSACK blocks we get
10893 	 * after a recovery incident.
10894 	 */
10895 	rack->r_ctl.dsack_byte_cnt += am;
10896 	if (!IN_FASTRECOVERY(rack->rc_tp->t_flags) &&
10897 	    rack->r_ctl.retran_during_recovery &&
10898 	    (rack->r_ctl.dsack_byte_cnt >= rack->r_ctl.retran_during_recovery)) {
10899 		/*
10900 		 * False recovery most likely culprit is reordering. If
10901 		 * nothing else is missing we need to revert.
10902 		 */
10903 		rack->r_might_revert = 1;
10904 		rack_handle_might_revert(rack->rc_tp, rack);
10905 		rack->r_might_revert = 0;
10906 		rack->r_ctl.retran_during_recovery = 0;
10907 		rack->r_ctl.dsack_byte_cnt = 0;
10908 	}
10909 	return (was_tlp);
10910 }
10911 
10912 static uint32_t
10913 do_rack_compute_pipe(struct tcpcb *tp, struct tcp_rack *rack, uint32_t snd_una)
10914 {
10915 	return (((tp->snd_max - snd_una) - rack->r_ctl.rc_sacked) + rack->r_ctl.rc_holes_rxt);
10916 }
10917 
10918 static int32_t
10919 rack_compute_pipe(struct tcpcb *tp)
10920 {
10921 	return ((int32_t)do_rack_compute_pipe(tp,
10922 					      (struct tcp_rack *)tp->t_fb_ptr,
10923 					      tp->snd_una));
10924 }
10925 
10926 static void
10927 rack_update_prr(struct tcpcb *tp, struct tcp_rack *rack, uint32_t changed, tcp_seq th_ack)
10928 {
10929 	/* Deal with changed and PRR here (in recovery only) */
10930 	uint32_t pipe, snd_una;
10931 
10932 	rack->r_ctl.rc_prr_delivered += changed;
10933 
10934 	if (sbavail(&rack->rc_inp->inp_socket->so_snd) <= (tp->snd_max - tp->snd_una)) {
10935 		/*
10936 		 * It is all outstanding, we are application limited
10937 		 * and thus we don't need more room to send anything.
10938 		 * Note we use tp->snd_una here and not th_ack because
10939 		 * the data as yet not been cut from the sb.
10940 		 */
10941 		rack->r_ctl.rc_prr_sndcnt = 0;
10942 		return;
10943 	}
10944 	/* Compute prr_sndcnt */
10945 	if (SEQ_GT(tp->snd_una, th_ack)) {
10946 		snd_una = tp->snd_una;
10947 	} else {
10948 		snd_una = th_ack;
10949 	}
10950 	pipe = do_rack_compute_pipe(tp, rack, snd_una);
10951 	if (pipe > tp->snd_ssthresh) {
10952 		long sndcnt;
10953 
10954 		sndcnt = rack->r_ctl.rc_prr_delivered * tp->snd_ssthresh;
10955 		if (rack->r_ctl.rc_prr_recovery_fs > 0)
10956 			sndcnt /= (long)rack->r_ctl.rc_prr_recovery_fs;
10957 		else {
10958 			rack->r_ctl.rc_prr_sndcnt = 0;
10959 			rack_log_to_prr(rack, 9, 0, __LINE__);
10960 			sndcnt = 0;
10961 		}
10962 		sndcnt++;
10963 		if (sndcnt > (long)rack->r_ctl.rc_prr_out)
10964 			sndcnt -= rack->r_ctl.rc_prr_out;
10965 		else
10966 			sndcnt = 0;
10967 		rack->r_ctl.rc_prr_sndcnt = sndcnt;
10968 		rack_log_to_prr(rack, 10, 0, __LINE__);
10969 	} else {
10970 		uint32_t limit;
10971 
10972 		if (rack->r_ctl.rc_prr_delivered > rack->r_ctl.rc_prr_out)
10973 			limit = (rack->r_ctl.rc_prr_delivered - rack->r_ctl.rc_prr_out);
10974 		else
10975 			limit = 0;
10976 		if (changed > limit)
10977 			limit = changed;
10978 		limit += ctf_fixed_maxseg(tp);
10979 		if (tp->snd_ssthresh > pipe) {
10980 			rack->r_ctl.rc_prr_sndcnt = min((tp->snd_ssthresh - pipe), limit);
10981 			rack_log_to_prr(rack, 11, 0, __LINE__);
10982 		} else {
10983 			rack->r_ctl.rc_prr_sndcnt = min(0, limit);
10984 			rack_log_to_prr(rack, 12, 0, __LINE__);
10985 		}
10986 	}
10987 }
10988 
10989 static void
10990 rack_log_ack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th, int entered_recovery, int dup_ack_struck,
10991 	     int *dsack_seen, int *sacks_seen)
10992 {
10993 	uint32_t changed;
10994 	struct tcp_rack *rack;
10995 	struct rack_sendmap *rsm;
10996 	struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1];
10997 	register uint32_t th_ack;
10998 	int32_t i, j, k, num_sack_blks = 0;
10999 	uint32_t cts, acked, ack_point;
11000 	int loop_start = 0, moved_two = 0, no_extra = 0;
11001 	uint32_t tsused;
11002 	uint32_t segsiz, o_cnt;
11003 
11004 
11005 	INP_WLOCK_ASSERT(tptoinpcb(tp));
11006 	if (tcp_get_flags(th) & TH_RST) {
11007 		/* We don't log resets */
11008 		return;
11009 	}
11010 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11011 	cts = tcp_get_usecs(NULL);
11012 	rsm = tqhash_min(rack->r_ctl.tqh);
11013 	changed = 0;
11014 	th_ack = th->th_ack;
11015 	if (rack->sack_attack_disable == 0)
11016 		rack_do_decay(rack);
11017 	segsiz = ctf_fixed_maxseg(rack->rc_tp);
11018 	if (BYTES_THIS_ACK(tp, th) >=  segsiz) {
11019 		/*
11020 		 * You only get credit for
11021 		 * MSS and greater (and you get extra
11022 		 * credit for larger cum-ack moves).
11023 		 */
11024 		int ac;
11025 
11026 		ac = BYTES_THIS_ACK(tp, th) / ctf_fixed_maxseg(rack->rc_tp);
11027 		rack->r_ctl.ack_count += ac;
11028 		counter_u64_add(rack_ack_total, ac);
11029 	}
11030 	if (rack->r_ctl.ack_count > 0xfff00000) {
11031 		/*
11032 		 * reduce the number to keep us under
11033 		 * a uint32_t.
11034 		 */
11035 		rack->r_ctl.ack_count /= 2;
11036 		rack->r_ctl.sack_count /= 2;
11037 	}
11038 	if (SEQ_GT(th_ack, tp->snd_una)) {
11039 		rack_log_progress_event(rack, tp, ticks, PROGRESS_UPDATE, __LINE__);
11040 		tp->t_acktime = ticks;
11041 	}
11042 	if (rsm && SEQ_GT(th_ack, rsm->r_start))
11043 		changed = th_ack - rsm->r_start;
11044 	if (changed) {
11045 		rack_process_to_cumack(tp, rack, th_ack, cts, to,
11046 				       tcp_tv_to_lusectick(&rack->r_ctl.act_rcv_time));
11047 	}
11048 	if ((to->to_flags & TOF_SACK) == 0) {
11049 		/* We are done nothing left and no sack. */
11050 		rack_handle_might_revert(tp, rack);
11051 		/*
11052 		 * For cases where we struck a dup-ack
11053 		 * with no SACK, add to the changes so
11054 		 * PRR will work right.
11055 		 */
11056 		if (dup_ack_struck && (changed == 0)) {
11057 			changed += ctf_fixed_maxseg(rack->rc_tp);
11058 		}
11059 		goto out;
11060 	}
11061 	/* Sack block processing */
11062 	if (SEQ_GT(th_ack, tp->snd_una))
11063 		ack_point = th_ack;
11064 	else
11065 		ack_point = tp->snd_una;
11066 	for (i = 0; i < to->to_nsacks; i++) {
11067 		bcopy((to->to_sacks + i * TCPOLEN_SACK),
11068 		      &sack, sizeof(sack));
11069 		sack.start = ntohl(sack.start);
11070 		sack.end = ntohl(sack.end);
11071 		if (SEQ_GT(sack.end, sack.start) &&
11072 		    SEQ_GT(sack.start, ack_point) &&
11073 		    SEQ_LT(sack.start, tp->snd_max) &&
11074 		    SEQ_GT(sack.end, ack_point) &&
11075 		    SEQ_LEQ(sack.end, tp->snd_max)) {
11076 			sack_blocks[num_sack_blks] = sack;
11077 			num_sack_blks++;
11078 		} else if (SEQ_LEQ(sack.start, th_ack) &&
11079 			   SEQ_LEQ(sack.end, th_ack)) {
11080 			int was_tlp;
11081 
11082 			if (dsack_seen != NULL)
11083 				*dsack_seen = 1;
11084 			was_tlp = rack_note_dsack(rack, sack.start, sack.end);
11085 			/*
11086 			 * Its a D-SACK block.
11087 			 */
11088 			tcp_record_dsack(tp, sack.start, sack.end, was_tlp);
11089 		}
11090 	}
11091 	if (rack->rc_dsack_round_seen) {
11092 		/* Is the dsack roound over? */
11093 		if (SEQ_GEQ(th_ack, rack->r_ctl.dsack_round_end)) {
11094 			/* Yes it is */
11095 			rack->rc_dsack_round_seen = 0;
11096 			rack_log_dsack_event(rack, 3, __LINE__, 0, 0);
11097 		}
11098 	}
11099 	/*
11100 	 * Sort the SACK blocks so we can update the rack scoreboard with
11101 	 * just one pass.
11102 	 */
11103 	o_cnt = num_sack_blks;
11104 	num_sack_blks = sack_filter_blks(&rack->r_ctl.rack_sf, sack_blocks,
11105 					 num_sack_blks, th->th_ack);
11106 	ctf_log_sack_filter(rack->rc_tp, num_sack_blks, sack_blocks);
11107 	if (sacks_seen != NULL)
11108 		*sacks_seen = num_sack_blks;
11109 	if (num_sack_blks == 0) {
11110 		/* Nothing to sack, but we need to update counts */
11111 		if ((o_cnt == 1) &&
11112 		    (*dsack_seen != 1))
11113 			rack->r_ctl.sack_count++;
11114 		else if (o_cnt > 1)
11115 			rack->r_ctl.sack_count++;
11116 		goto out_with_totals;
11117 	}
11118 	if (rack->sack_attack_disable) {
11119 		/*
11120 		 * An attacker disablement is in place, for
11121 		 * every sack block that is not at least a full MSS
11122 		 * count up sack_count.
11123 		 */
11124 		for (i = 0; i < num_sack_blks; i++) {
11125 			if ((sack_blocks[i].end - sack_blocks[i].start) < segsiz) {
11126 				rack->r_ctl.sack_count++;
11127 			}
11128 			if (rack->r_ctl.sack_count > 0xfff00000) {
11129 				/*
11130 				 * reduce the number to keep us under
11131 				 * a uint32_t.
11132 				 */
11133 				rack->r_ctl.ack_count /= 2;
11134 				rack->r_ctl.sack_count /= 2;
11135 			}
11136 		}
11137 		goto out;
11138 	}
11139 	/* Its a sack of some sort */
11140 	rack->r_ctl.sack_count += num_sack_blks;
11141 	if (rack->r_ctl.sack_count > 0xfff00000) {
11142 		/*
11143 		 * reduce the number to keep us under
11144 		 * a uint32_t.
11145 		 */
11146 		rack->r_ctl.ack_count /= 2;
11147 		rack->r_ctl.sack_count /= 2;
11148 	}
11149 	if (num_sack_blks < 2) {
11150 		/* Only one, we don't need to sort */
11151 		goto do_sack_work;
11152 	}
11153 	/* Sort the sacks */
11154 	for (i = 0; i < num_sack_blks; i++) {
11155 		for (j = i + 1; j < num_sack_blks; j++) {
11156 			if (SEQ_GT(sack_blocks[i].end, sack_blocks[j].end)) {
11157 				sack = sack_blocks[i];
11158 				sack_blocks[i] = sack_blocks[j];
11159 				sack_blocks[j] = sack;
11160 			}
11161 		}
11162 	}
11163 	/*
11164 	 * Now are any of the sack block ends the same (yes some
11165 	 * implementations send these)?
11166 	 */
11167 again:
11168 	if (num_sack_blks == 0)
11169 		goto out_with_totals;
11170 	if (num_sack_blks > 1) {
11171 		for (i = 0; i < num_sack_blks; i++) {
11172 			for (j = i + 1; j < num_sack_blks; j++) {
11173 				if (sack_blocks[i].end == sack_blocks[j].end) {
11174 					/*
11175 					 * Ok these two have the same end we
11176 					 * want the smallest end and then
11177 					 * throw away the larger and start
11178 					 * again.
11179 					 */
11180 					if (SEQ_LT(sack_blocks[j].start, sack_blocks[i].start)) {
11181 						/*
11182 						 * The second block covers
11183 						 * more area use that
11184 						 */
11185 						sack_blocks[i].start = sack_blocks[j].start;
11186 					}
11187 					/*
11188 					 * Now collapse out the dup-sack and
11189 					 * lower the count
11190 					 */
11191 					for (k = (j + 1); k < num_sack_blks; k++) {
11192 						sack_blocks[j].start = sack_blocks[k].start;
11193 						sack_blocks[j].end = sack_blocks[k].end;
11194 						j++;
11195 					}
11196 					num_sack_blks--;
11197 					goto again;
11198 				}
11199 			}
11200 		}
11201 	}
11202 do_sack_work:
11203 	/*
11204 	 * First lets look to see if
11205 	 * we have retransmitted and
11206 	 * can use the transmit next?
11207 	 */
11208 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
11209 	if (rsm &&
11210 	    SEQ_GT(sack_blocks[0].end, rsm->r_start) &&
11211 	    SEQ_LT(sack_blocks[0].start, rsm->r_end)) {
11212 		/*
11213 		 * We probably did the FR and the next
11214 		 * SACK in continues as we would expect.
11215 		 */
11216 		acked = rack_proc_sack_blk(tp, rack, &sack_blocks[0], to, &rsm, cts, &no_extra, &moved_two, segsiz);
11217 		if (acked) {
11218 			rack->r_wanted_output = 1;
11219 			changed += acked;
11220 		}
11221 		if (num_sack_blks == 1) {
11222 			/*
11223 			 * This is what we would expect from
11224 			 * a normal implementation to happen
11225 			 * after we have retransmitted the FR,
11226 			 * i.e the sack-filter pushes down
11227 			 * to 1 block and the next to be retransmitted
11228 			 * is the sequence in the sack block (has more
11229 			 * are acked). Count this as ACK'd data to boost
11230 			 * up the chances of recovering any false positives.
11231 			 */
11232 			rack->r_ctl.ack_count += (acked / ctf_fixed_maxseg(rack->rc_tp));
11233 			counter_u64_add(rack_ack_total, (acked / ctf_fixed_maxseg(rack->rc_tp)));
11234 			counter_u64_add(rack_express_sack, 1);
11235 			if (rack->r_ctl.ack_count > 0xfff00000) {
11236 				/*
11237 				 * reduce the number to keep us under
11238 				 * a uint32_t.
11239 				 */
11240 				rack->r_ctl.ack_count /= 2;
11241 				rack->r_ctl.sack_count /= 2;
11242 			}
11243 			if (moved_two) {
11244 				/*
11245 				 * If we did not get a SACK for at least a MSS and
11246 				 * had to move at all, or if we moved more than our
11247 				 * threshold, it counts against the "extra" move.
11248 				 */
11249 				rack->r_ctl.sack_moved_extra += moved_two;
11250 				rack->r_ctl.sack_noextra_move += no_extra;
11251 				counter_u64_add(rack_move_some, 1);
11252 			} else {
11253 				/*
11254 				 * else we did not have to move
11255 				 * any more than we would expect.
11256 				 */
11257 				rack->r_ctl.sack_noextra_move += no_extra;
11258 				rack->r_ctl.sack_noextra_move++;
11259 				counter_u64_add(rack_move_none, 1);
11260 			}
11261 			if ((rack->r_ctl.sack_moved_extra > 0xfff00000) ||
11262 			    (rack->r_ctl.sack_noextra_move > 0xfff00000)) {
11263 				rack->r_ctl.sack_moved_extra /= 2;
11264 				rack->r_ctl.sack_noextra_move /= 2;
11265 			}
11266 			goto out_with_totals;
11267 		} else {
11268 			/*
11269 			 * Start the loop through the
11270 			 * rest of blocks, past the first block.
11271 			 */
11272 			loop_start = 1;
11273 		}
11274 	}
11275 	counter_u64_add(rack_sack_total, 1);
11276 	rsm = rack->r_ctl.rc_sacklast;
11277 	for (i = loop_start; i < num_sack_blks; i++) {
11278 		acked = rack_proc_sack_blk(tp, rack, &sack_blocks[i], to, &rsm, cts, &no_extra, &moved_two, segsiz);
11279 		if (acked) {
11280 			rack->r_wanted_output = 1;
11281 			changed += acked;
11282 		}
11283 		if (moved_two) {
11284 			/*
11285 			 * If we did not get a SACK for at least a MSS and
11286 			 * had to move at all, or if we moved more than our
11287 			 * threshold, it counts against the "extra" move.
11288 			 */
11289 			rack->r_ctl.sack_moved_extra += moved_two;
11290 			rack->r_ctl.sack_noextra_move += no_extra;
11291 			counter_u64_add(rack_move_some, 1);
11292 		} else {
11293 			/*
11294 			 * else we did not have to move
11295 			 * any more than we would expect.
11296 			 */
11297 			rack->r_ctl.sack_noextra_move += no_extra;
11298 			rack->r_ctl.sack_noextra_move++;
11299 			counter_u64_add(rack_move_none, 1);
11300 		}
11301 		if ((rack->r_ctl.sack_moved_extra > 0xfff00000) ||
11302 		    (rack->r_ctl.sack_noextra_move > 0xfff00000)) {
11303 			rack->r_ctl.sack_moved_extra /= 2;
11304 			rack->r_ctl.sack_noextra_move /= 2;
11305 		}
11306 		if (moved_two && (acked < ctf_fixed_maxseg(rack->rc_tp))) {
11307 			/*
11308 			 * If the SACK was not a full MSS then
11309 			 * we add to sack_count the number of
11310 			 * MSS's (or possibly more than
11311 			 * a MSS if its a TSO send) we had to skip by.
11312 			 */
11313 			rack->r_ctl.sack_count += moved_two;
11314 			if (rack->r_ctl.sack_count > 0xfff00000) {
11315 				rack->r_ctl.ack_count /= 2;
11316 				rack->r_ctl.sack_count /= 2;
11317 			}
11318 			counter_u64_add(rack_sack_total, moved_two);
11319 		}
11320 		/*
11321 		 * Now we need to setup for the next
11322 		 * round. First we make sure we won't
11323 		 * exceed the size of our uint32_t on
11324 		 * the various counts, and then clear out
11325 		 * moved_two.
11326 		 */
11327 		moved_two = 0;
11328 		no_extra = 0;
11329 	}
11330 out_with_totals:
11331 	if (num_sack_blks > 1) {
11332 		/*
11333 		 * You get an extra stroke if
11334 		 * you have more than one sack-blk, this
11335 		 * could be where we are skipping forward
11336 		 * and the sack-filter is still working, or
11337 		 * it could be an attacker constantly
11338 		 * moving us.
11339 		 */
11340 		rack->r_ctl.sack_moved_extra++;
11341 		counter_u64_add(rack_move_some, 1);
11342 	}
11343 out:
11344 #ifdef TCP_SAD_DETECTION
11345 	rack_do_detection(tp, rack, BYTES_THIS_ACK(tp, th), ctf_fixed_maxseg(rack->rc_tp));
11346 #endif
11347 	if (changed) {
11348 		/* Something changed cancel the rack timer */
11349 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
11350 	}
11351 	tsused = tcp_get_usecs(NULL);
11352 	rsm = tcp_rack_output(tp, rack, tsused);
11353 	if ((!IN_FASTRECOVERY(tp->t_flags)) &&
11354 	    rsm &&
11355 	    ((rsm->r_flags & RACK_MUST_RXT) == 0)) {
11356 		/* Enter recovery */
11357 		entered_recovery = 1;
11358 		rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
11359 		/*
11360 		 * When we enter recovery we need to assure we send
11361 		 * one packet.
11362 		 */
11363 		if (rack->rack_no_prr == 0) {
11364 			rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
11365 			rack_log_to_prr(rack, 8, 0, __LINE__);
11366 		}
11367 		rack->r_timer_override = 1;
11368 		rack->r_early = 0;
11369 		rack->r_ctl.rc_agg_early = 0;
11370 	} else if (IN_FASTRECOVERY(tp->t_flags) &&
11371 		   rsm &&
11372 		   (rack->r_rr_config == 3)) {
11373 		/*
11374 		 * Assure we can output and we get no
11375 		 * remembered pace time except the retransmit.
11376 		 */
11377 		rack->r_timer_override = 1;
11378 		rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
11379 		rack->r_ctl.rc_resend = rsm;
11380 	}
11381 	if (IN_FASTRECOVERY(tp->t_flags) &&
11382 	    (rack->rack_no_prr == 0) &&
11383 	    (entered_recovery == 0)) {
11384 		rack_update_prr(tp, rack, changed, th_ack);
11385 		if ((rsm && (rack->r_ctl.rc_prr_sndcnt >= ctf_fixed_maxseg(tp)) &&
11386 		     ((tcp_in_hpts(rack->rc_inp) == 0) &&
11387 		      ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)))) {
11388 			/*
11389 			 * If you are pacing output you don't want
11390 			 * to override.
11391 			 */
11392 			rack->r_early = 0;
11393 			rack->r_ctl.rc_agg_early = 0;
11394 			rack->r_timer_override = 1;
11395 		}
11396 	}
11397 }
11398 
11399 static void
11400 rack_strike_dupack(struct tcp_rack *rack)
11401 {
11402 	struct rack_sendmap *rsm;
11403 
11404 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
11405 	while (rsm) {
11406 		/*
11407 		 * We need to skip anything already set
11408 		 * to be retransmitted.
11409 		 */
11410 		if ((rsm->r_dupack >= DUP_ACK_THRESHOLD)  ||
11411 		    (rsm->r_flags & RACK_MUST_RXT)) {
11412 			rsm = TAILQ_NEXT(rsm, r_tnext);
11413 			continue;
11414 		}
11415 		break;
11416 	}
11417 	if (rsm && (rsm->r_dupack < 0xff)) {
11418 		rsm->r_dupack++;
11419 		if (rsm->r_dupack >= DUP_ACK_THRESHOLD) {
11420 			struct timeval tv;
11421 			uint32_t cts;
11422 			/*
11423 			 * Here we see if we need to retransmit. For
11424 			 * a SACK type connection if enough time has passed
11425 			 * we will get a return of the rsm. For a non-sack
11426 			 * connection we will get the rsm returned if the
11427 			 * dupack value is 3 or more.
11428 			 */
11429 			cts = tcp_get_usecs(&tv);
11430 			rack->r_ctl.rc_resend = tcp_rack_output(rack->rc_tp, rack, cts);
11431 			if (rack->r_ctl.rc_resend != NULL) {
11432 				if (!IN_FASTRECOVERY(rack->rc_tp->t_flags)) {
11433 					rack_cong_signal(rack->rc_tp, CC_NDUPACK,
11434 							 rack->rc_tp->snd_una, __LINE__);
11435 				}
11436 				rack->r_wanted_output = 1;
11437 				rack->r_timer_override = 1;
11438 				rack_log_retran_reason(rack, rsm, __LINE__, 1, 3);
11439 			}
11440 		} else {
11441 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 3);
11442 		}
11443 	}
11444 }
11445 
11446 static void
11447 rack_check_bottom_drag(struct tcpcb *tp,
11448 		       struct tcp_rack *rack,
11449 		       struct socket *so)
11450 {
11451 	uint32_t segsiz, minseg;
11452 
11453 	segsiz = ctf_fixed_maxseg(tp);
11454 	minseg = segsiz;
11455 	if (tp->snd_max == tp->snd_una) {
11456 		/*
11457 		 * We are doing dynamic pacing and we are way
11458 		 * under. Basically everything got acked while
11459 		 * we were still waiting on the pacer to expire.
11460 		 *
11461 		 * This means we need to boost the b/w in
11462 		 * addition to any earlier boosting of
11463 		 * the multiplier.
11464 		 */
11465 		uint64_t lt_bw;
11466 
11467 		lt_bw = rack_get_lt_bw(rack);
11468 		rack->rc_dragged_bottom = 1;
11469 		rack_validate_multipliers_at_or_above100(rack);
11470 		if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_VALID) &&
11471 		    (lt_bw > 0)) {
11472 			/*
11473 			 * Lets use the long-term b/w we have
11474 			 * been getting as a base.
11475 			 */
11476 			if (rack->rc_gp_filled == 0) {
11477 				if (lt_bw > ONE_POINT_TWO_MEG) {
11478 					/*
11479 					 * If we have no measurement
11480 					 * don't let us set in more than
11481 					 * 1.2Mbps. If we are still too
11482 					 * low after pacing with this we
11483 					 * will hopefully have a max b/w
11484 					 * available to sanity check things.
11485 					 */
11486 					lt_bw = ONE_POINT_TWO_MEG;
11487 				}
11488 				rack->r_ctl.rc_rtt_diff = 0;
11489 				rack->r_ctl.gp_bw = lt_bw;
11490 				rack->rc_gp_filled = 1;
11491 				if (rack->r_ctl.num_measurements < RACK_REQ_AVG)
11492 					rack->r_ctl.num_measurements = RACK_REQ_AVG;
11493 				rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
11494 			} else if (lt_bw > rack->r_ctl.gp_bw) {
11495 				rack->r_ctl.rc_rtt_diff = 0;
11496 				if (rack->r_ctl.num_measurements < RACK_REQ_AVG)
11497 					rack->r_ctl.num_measurements = RACK_REQ_AVG;
11498 				rack->r_ctl.gp_bw = lt_bw;
11499 				rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
11500 			} else
11501 				rack_increase_bw_mul(rack, -1, 0, 0, 1);
11502 			if ((rack->gp_ready == 0) &&
11503 			    (rack->r_ctl.num_measurements >= rack->r_ctl.req_measurements)) {
11504 				/* We have enough measurements now */
11505 				rack->gp_ready = 1;
11506 				if ((rack->rc_always_pace && (rack->use_fixed_rate == 0)) ||
11507 				    rack->rack_hibeta)
11508 					rack_set_cc_pacing(rack);
11509 				if (rack->defer_options)
11510 					rack_apply_deferred_options(rack);
11511 			}
11512 		} else {
11513 			/*
11514 			 * zero rtt possibly?, settle for just an old increase.
11515 			 */
11516 			rack_increase_bw_mul(rack, -1, 0, 0, 1);
11517 		}
11518 	} else if ((IN_FASTRECOVERY(tp->t_flags) == 0) &&
11519 		   (sbavail(&so->so_snd) > max((segsiz * (4 + rack_req_segs)),
11520 					       minseg)) &&
11521 		   (rack->r_ctl.cwnd_to_use > max((segsiz * (rack_req_segs + 2)), minseg)) &&
11522 		   (tp->snd_wnd > max((segsiz * (rack_req_segs + 2)), minseg)) &&
11523 		   (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) <=
11524 		    (segsiz * rack_req_segs))) {
11525 		/*
11526 		 * We are doing dynamic GP pacing and
11527 		 * we have everything except 1MSS or less
11528 		 * bytes left out. We are still pacing away.
11529 		 * And there is data that could be sent, This
11530 		 * means we are inserting delayed ack time in
11531 		 * our measurements because we are pacing too slow.
11532 		 */
11533 		rack_validate_multipliers_at_or_above100(rack);
11534 		rack->rc_dragged_bottom = 1;
11535 		rack_increase_bw_mul(rack, -1, 0, 0, 1);
11536 	}
11537 }
11538 
11539 #ifdef TCP_REQUEST_TRK
11540 static void
11541 rack_log_hybrid(struct tcp_rack *rack, uint32_t seq,
11542 		struct http_sendfile_track *cur, uint8_t mod, int line, int err)
11543 {
11544 	int do_log;
11545 
11546 	do_log = tcp_bblogging_on(rack->rc_tp);
11547 	if (do_log == 0) {
11548 		if ((do_log = tcp_bblogging_point_on(rack->rc_tp, TCP_BBPOINT_REQ_LEVEL_LOGGING) )== 0)
11549 			return;
11550 		/* We only allow the three below with point logging on */
11551 		if ((mod != HYBRID_LOG_RULES_APP) &&
11552 		    (mod != HYBRID_LOG_RULES_SET) &&
11553 		    (mod != HYBRID_LOG_REQ_COMP))
11554 			return;
11555 
11556 	}
11557 	if (do_log) {
11558 		union tcp_log_stackspecific log;
11559 		struct timeval tv;
11560 
11561 		/* Convert our ms to a microsecond */
11562 		memset(&log, 0, sizeof(log));
11563 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
11564 		log.u_bbr.flex1 = seq;
11565 		log.u_bbr.cwnd_gain = line;
11566 		if (cur != NULL) {
11567 			uint64_t off;
11568 
11569 			log.u_bbr.flex2 = cur->start_seq;
11570 			log.u_bbr.flex3 = cur->end_seq;
11571 			log.u_bbr.flex4 = (uint32_t)((cur->localtime >> 32) & 0x00000000ffffffff);
11572 			log.u_bbr.flex5 = (uint32_t)(cur->localtime & 0x00000000ffffffff);
11573 			log.u_bbr.flex6 = cur->flags;
11574 			log.u_bbr.pkts_out = cur->hybrid_flags;
11575 			log.u_bbr.rttProp = cur->timestamp;
11576 			log.u_bbr.cur_del_rate = cur->cspr;
11577 			log.u_bbr.bw_inuse = cur->start;
11578 			log.u_bbr.applimited = (uint32_t)(cur->end & 0x00000000ffffffff);
11579 			log.u_bbr.delivered = (uint32_t)((cur->end >> 32) & 0x00000000ffffffff) ;
11580 			log.u_bbr.epoch = (uint32_t)(cur->deadline & 0x00000000ffffffff);
11581 			log.u_bbr.lt_epoch = (uint32_t)((cur->deadline >> 32) & 0x00000000ffffffff) ;
11582 			log.u_bbr.bbr_state = 1;
11583 			off = (uint64_t)(cur) - (uint64_t)(&rack->rc_tp->t_http_info[0]);
11584 			log.u_bbr.use_lt_bw = (uint8_t)(off / sizeof(struct http_sendfile_track));
11585 		} else {
11586 			log.u_bbr.flex2 = err;
11587 		}
11588 		/*
11589 		 * Fill in flex7 to be CHD (catchup|hybrid|DGP)
11590 		 */
11591 		log.u_bbr.flex7 = rack->rc_catch_up;
11592 		log.u_bbr.flex7 <<= 1;
11593 		log.u_bbr.flex7 |= rack->rc_hybrid_mode;
11594 		log.u_bbr.flex7 <<= 1;
11595 		log.u_bbr.flex7 |= rack->dgp_on;
11596 		log.u_bbr.flex8 = mod;
11597 		log.u_bbr.delRate = rack->r_ctl.bw_rate_cap;
11598 		log.u_bbr.bbr_substate = rack->r_ctl.client_suggested_maxseg;
11599 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
11600 		log.u_bbr.pkt_epoch = rack->rc_tp->tcp_hybrid_start;
11601 		log.u_bbr.lost = rack->rc_tp->tcp_hybrid_error;
11602 		log.u_bbr.pacing_gain = (uint16_t)rack->rc_tp->tcp_hybrid_stop;
11603 		tcp_log_event(rack->rc_tp, NULL,
11604 		    &rack->rc_inp->inp_socket->so_rcv,
11605 		    &rack->rc_inp->inp_socket->so_snd,
11606 		    TCP_HYBRID_PACING_LOG, 0,
11607 	            0, &log, false, NULL, __func__, __LINE__, &tv);
11608 	}
11609 }
11610 #endif
11611 
11612 #ifdef TCP_REQUEST_TRK
11613 static void
11614 rack_set_dgp_hybrid_mode(struct tcp_rack *rack, tcp_seq seq, uint32_t len)
11615 {
11616 	struct http_sendfile_track *rc_cur;
11617 	struct tcpcb *tp;
11618 	int err = 0;
11619 
11620 	rc_cur = tcp_http_find_req_for_seq(rack->rc_tp, seq);
11621 	if (rc_cur == NULL) {
11622 		/* If not in the beginning what about the end piece */
11623 		rack_log_hybrid(rack, seq, NULL, HYBRID_LOG_NO_RANGE, __LINE__, err);
11624 		rc_cur = tcp_http_find_req_for_seq(rack->rc_tp, (seq + len - 1));
11625 	} else {
11626 		err = 12345;
11627 	}
11628 	/* If we find no parameters we are in straight DGP mode */
11629 	if(rc_cur == NULL) {
11630 		/* None found for this seq, just DGP for now */
11631 		rack->r_ctl.client_suggested_maxseg = 0;
11632 		rack->rc_catch_up = 0;
11633 		rack->r_ctl.bw_rate_cap = 0;
11634 		rack_log_hybrid(rack, (seq + len - 1), NULL, HYBRID_LOG_NO_RANGE, __LINE__, err);
11635 		if (rack->r_ctl.rc_last_sft) {
11636 			rack->r_ctl.rc_last_sft = NULL;
11637 		}
11638 		return;
11639 	}
11640 	/*
11641 	 * Ok if we have a new entry *or* have never
11642 	 * set up an entry we need to proceed. If
11643 	 * we have already set it up this entry we
11644 	 * just continue along with what we already
11645 	 * setup.
11646 	 */
11647 	tp = rack->rc_tp;
11648 	if ((rack->r_ctl.rc_last_sft != NULL) &&
11649 	    (rack->r_ctl.rc_last_sft == rc_cur)) {
11650 		/* Its already in place */
11651 		rack_log_hybrid(rack, seq, rc_cur, HYBRID_LOG_ISSAME, __LINE__, 0);
11652 		return;
11653 	}
11654 	if (rack->rc_hybrid_mode == 0) {
11655 		rack->r_ctl.rc_last_sft = rc_cur;
11656 		rack_log_hybrid(rack, seq, rc_cur, HYBRID_LOG_RULES_APP, __LINE__, 0);
11657 		return;
11658 	}
11659 	if ((rc_cur->hybrid_flags & TCP_HYBRID_PACING_CSPR) && rc_cur->cspr){
11660 		/* Compensate for all the header overhead's */
11661 		rack->r_ctl.bw_rate_cap	= rack_compensate_for_linerate(rack, rc_cur->cspr);
11662 	} else
11663 		rack->r_ctl.bw_rate_cap = 0;
11664 	if (rc_cur->hybrid_flags & TCP_HYBRID_PACING_H_MS)
11665 		rack->r_ctl.client_suggested_maxseg = rc_cur->hint_maxseg;
11666 	else
11667 		rack->r_ctl.client_suggested_maxseg = 0;
11668 	if ((rc_cur->hybrid_flags & TCP_HYBRID_PACING_CU) &&
11669 	    (rc_cur->cspr > 0)) {
11670 		uint64_t len;
11671 
11672 		rack->rc_catch_up = 1;
11673 		/*
11674 		 * Calculate the deadline time, first set the
11675 		 * time to when the request arrived.
11676 		 */
11677 		rc_cur->deadline = rc_cur->localtime;
11678 		/*
11679 		 * Next calculate the length and compensate for
11680 		 * TLS if need be.
11681 		 */
11682 		len = rc_cur->end - rc_cur->start;
11683 		if (tp->t_inpcb.inp_socket->so_snd.sb_tls_info) {
11684 			/*
11685 			 * This session is doing TLS. Take a swag guess
11686 			 * at the overhead.
11687 			 */
11688 			len += tcp_estimate_tls_overhead(tp->t_inpcb.inp_socket, len);
11689 		}
11690 		/*
11691 		 * Now considering the size, and the cspr, what is the time that
11692 		 * would be required at the cspr rate. Here we use the raw
11693 		 * cspr value since the client only looks at the raw data. We
11694 		 * do use len which includes TLS overhead, but not the TCP/IP etc.
11695 		 * That will get made up for in the CU pacing rate set.
11696 		 */
11697 		len *= HPTS_USEC_IN_SEC;
11698 		len /= rc_cur->cspr;
11699 		rc_cur->deadline += len;
11700 	} else {
11701 		rack->rc_catch_up = 0;
11702 		rc_cur->deadline = 0;
11703 	}
11704 	if (rack->r_ctl.client_suggested_maxseg != 0) {
11705 		/*
11706 		 * We need to reset the max pace segs if we have a
11707 		 * client_suggested_maxseg.
11708 		 */
11709 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
11710 	}
11711 	rack_log_hybrid(rack, seq, rc_cur, HYBRID_LOG_RULES_APP, __LINE__, 0);
11712 	/* Remember it for next time and for CU mode */
11713 	rack->r_ctl.rc_last_sft = rc_cur;
11714 }
11715 #endif
11716 
11717 static void
11718 rack_chk_http_and_hybrid_on_out(struct tcp_rack *rack, tcp_seq seq, uint32_t len, uint64_t cts)
11719 {
11720 #ifdef TCP_REQUEST_TRK
11721 	struct http_sendfile_track *ent;
11722 
11723 	ent = rack->r_ctl.rc_last_sft;
11724 	if ((ent == NULL) ||
11725 	    (ent->flags == TCP_HTTP_TRACK_FLG_EMPTY) ||
11726 	    (SEQ_GEQ(seq, ent->end_seq))) {
11727 		/* Time to update the track. */
11728 		rack_set_dgp_hybrid_mode(rack, seq, len);
11729 		ent = rack->r_ctl.rc_last_sft;
11730 	}
11731 	/* Out of all */
11732 	if (ent == NULL) {
11733 		return;
11734 	}
11735 	if (SEQ_LT(ent->end_seq, (seq + len))) {
11736 		/*
11737 		 * This is the case where our end_seq guess
11738 		 * was wrong. This is usually due to TLS having
11739 		 * more bytes then our guess. It could also be the
11740 		 * case that the client sent in two requests closely
11741 		 * and the SB is full of both so we are sending part
11742 		 * of each (end|beg). In such a case lets move this
11743 		 * guys end to match the end of this send. That
11744 		 * way it will complete when all of it is acked.
11745 		 */
11746 		ent->end_seq = (seq + len);
11747 		rack_log_hybrid_bw(rack, seq, len, 0, 0, HYBRID_LOG_EXTEND, 0, ent);
11748 	}
11749 	/* Now validate we have set the send time of this one */
11750 	if ((ent->flags & TCP_HTTP_TRACK_FLG_FSND) == 0) {
11751 		ent->flags |= TCP_HTTP_TRACK_FLG_FSND;
11752 		ent->first_send = cts;
11753 		ent->sent_at_fs = rack->rc_tp->t_sndbytes;
11754 		ent->rxt_at_fs = rack->rc_tp->t_snd_rxt_bytes;
11755 	}
11756 #endif
11757 }
11758 
11759 static void
11760 rack_gain_for_fastoutput(struct tcp_rack *rack, struct tcpcb *tp, struct socket *so, uint32_t acked_amount)
11761 {
11762 	/*
11763 	 * The fast output path is enabled and we
11764 	 * have moved the cumack forward. Lets see if
11765 	 * we can expand forward the fast path length by
11766 	 * that amount. What we would ideally like to
11767 	 * do is increase the number of bytes in the
11768 	 * fast path block (left_to_send) by the
11769 	 * acked amount. However we have to gate that
11770 	 * by two factors:
11771 	 * 1) The amount outstanding and the rwnd of the peer
11772 	 *    (i.e. we don't want to exceed the rwnd of the peer).
11773 	 *    <and>
11774 	 * 2) The amount of data left in the socket buffer (i.e.
11775 	 *    we can't send beyond what is in the buffer).
11776 	 *
11777 	 * Note that this does not take into account any increase
11778 	 * in the cwnd. We will only extend the fast path by
11779 	 * what was acked.
11780 	 */
11781 	uint32_t new_total, gating_val;
11782 
11783 	new_total = acked_amount + rack->r_ctl.fsb.left_to_send;
11784 	gating_val = min((sbavail(&so->so_snd) - (tp->snd_max - tp->snd_una)),
11785 			 (tp->snd_wnd - (tp->snd_max - tp->snd_una)));
11786 	if (new_total <= gating_val) {
11787 		/* We can increase left_to_send by the acked amount */
11788 		counter_u64_add(rack_extended_rfo, 1);
11789 		rack->r_ctl.fsb.left_to_send = new_total;
11790 		KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(&rack->rc_inp->inp_socket->so_snd) - (tp->snd_max - tp->snd_una))),
11791 			("rack:%p left_to_send:%u sbavail:%u out:%u",
11792 			 rack, rack->r_ctl.fsb.left_to_send,
11793 			 sbavail(&rack->rc_inp->inp_socket->so_snd),
11794 			 (tp->snd_max - tp->snd_una)));
11795 
11796 	}
11797 }
11798 
11799 static void
11800 rack_adjust_sendmap_head(struct tcp_rack *rack, struct sockbuf *sb)
11801 {
11802 	/*
11803 	 * Here any sendmap entry that points to the
11804 	 * beginning mbuf must be adjusted to the correct
11805 	 * offset. This must be called with:
11806 	 * 1) The socket buffer locked
11807 	 * 2) snd_una adjusted to its new position.
11808 	 *
11809 	 * Note that (2) implies rack_ack_received has also
11810 	 * been called and all the sbcut's have been done.
11811 	 *
11812 	 * We grab the first mbuf in the socket buffer and
11813 	 * then go through the front of the sendmap, recalculating
11814 	 * the stored offset for any sendmap entry that has
11815 	 * that mbuf. We must use the sb functions to do this
11816 	 * since its possible an add was done has well as
11817 	 * the subtraction we may have just completed. This should
11818 	 * not be a penalty though, since we just referenced the sb
11819 	 * to go in and trim off the mbufs that we freed (of course
11820 	 * there will be a penalty for the sendmap references though).
11821 	 *
11822 	 * Note also with INVARIANT on, we validate with a KASSERT
11823 	 * that the first sendmap entry has a soff of 0.
11824 	 *
11825 	 */
11826 	struct mbuf *m;
11827 	struct rack_sendmap *rsm;
11828 	tcp_seq snd_una;
11829 #ifdef INVARIANTS
11830 	int first_processed = 0;
11831 #endif
11832 
11833 	snd_una = rack->rc_tp->snd_una;
11834 	SOCKBUF_LOCK_ASSERT(sb);
11835 	m = sb->sb_mb;
11836 	rsm = tqhash_min(rack->r_ctl.tqh);
11837 	if ((rsm == NULL) || (m == NULL)) {
11838 		/* Nothing outstanding */
11839 		return;
11840 	}
11841 	/* The very first RSM's mbuf must point to the head mbuf in the sb */
11842 	KASSERT((rsm->m == m),
11843 		("Rack:%p sb:%p rsm:%p -- first rsm mbuf not aligned to sb",
11844 		 rack, sb, rsm));
11845 	while (rsm->m && (rsm->m == m)) {
11846 		/* one to adjust */
11847 #ifdef INVARIANTS
11848 		struct mbuf *tm;
11849 		uint32_t soff;
11850 
11851 		tm = sbsndmbuf(sb, (rsm->r_start - snd_una), &soff);
11852 		if ((rsm->orig_m_len != m->m_len) ||
11853 		    (rsm->orig_t_space != M_TRAILINGROOM(m))){
11854 			rack_adjust_orig_mlen(rsm);
11855 		}
11856 		if (first_processed == 0) {
11857 			KASSERT((rsm->soff == 0),
11858 				("Rack:%p rsm:%p -- rsm at head but soff not zero",
11859 				 rack, rsm));
11860 			first_processed = 1;
11861 		}
11862 		if ((rsm->soff != soff) || (rsm->m != tm)) {
11863 			/*
11864 			 * This is not a fatal error, we anticipate it
11865 			 * might happen (the else code), so we count it here
11866 			 * so that under invariant we can see that it really
11867 			 * does happen.
11868 			 */
11869 			counter_u64_add(rack_adjust_map_bw, 1);
11870 		}
11871 		rsm->m = tm;
11872 		rsm->soff = soff;
11873 		if (tm) {
11874 			rsm->orig_m_len = rsm->m->m_len;
11875 			rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
11876 		} else {
11877 			rsm->orig_m_len = 0;
11878 			rsm->orig_t_space = 0;
11879 		}
11880 #else
11881 		rsm->m = sbsndmbuf(sb, (rsm->r_start - snd_una), &rsm->soff);
11882 		if (rsm->m) {
11883 			rsm->orig_m_len = rsm->m->m_len;
11884 			rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
11885 		} else {
11886 			rsm->orig_m_len = 0;
11887 			rsm->orig_t_space = 0;
11888 		}
11889 #endif
11890 		rsm = tqhash_next(rack->r_ctl.tqh, rsm);
11891 		if (rsm == NULL)
11892 			break;
11893 	}
11894 }
11895 
11896 #ifdef TCP_REQUEST_TRK
11897 static inline void
11898 rack_http_check_for_comp(struct tcp_rack *rack, tcp_seq th_ack)
11899 {
11900 	struct http_sendfile_track *ent;
11901 	int i;
11902 
11903 	if ((rack->rc_hybrid_mode == 0) &&
11904 	    (tcp_bblogging_point_on(rack->rc_tp, TCP_BBPOINT_REQ_LEVEL_LOGGING) == 0)) {
11905 		/*
11906 		 * Just do normal completions hybrid pacing is not on
11907 		 * and CLDL is off as well.
11908 		 */
11909 		tcp_http_check_for_comp(rack->rc_tp, th_ack);
11910 		return;
11911 	}
11912 	/*
11913 	 * Originally I was just going to find the th_ack associated
11914 	 * with an entry. But then I realized a large strech ack could
11915 	 * in theory ack two or more requests at once. So instead we
11916 	 * need to find all entries that are completed by th_ack not
11917 	 * just a single entry and do our logging.
11918 	 */
11919 	ent = tcp_http_find_a_req_that_is_completed_by(rack->rc_tp, th_ack, &i);
11920 	while (ent != NULL) {
11921 		/*
11922 		 * We may be doing hybrid pacing or CLDL and need more details possibly
11923 		 * so we do it manually instead of calling
11924 		 * tcp_http_check_for_comp()
11925 		 */
11926 		uint64_t laa, tim, data, cbw, ftim;
11927 
11928 		/* Ok this ack frees it */
11929 		rack_log_hybrid(rack, th_ack,
11930 				ent, HYBRID_LOG_REQ_COMP, __LINE__, 0);
11931 		/* calculate the time based on the ack arrival */
11932 		data = ent->end - ent->start;
11933 		laa = tcp_tv_to_lusectick(&rack->r_ctl.act_rcv_time);
11934 		if (ent->flags & TCP_HTTP_TRACK_FLG_FSND) {
11935 			if (ent->first_send > ent->localtime)
11936 				ftim = ent->first_send;
11937 			else
11938 				ftim = ent->localtime;
11939 		} else {
11940 			/* TSNH */
11941 			ftim = ent->localtime;
11942 		}
11943 		if (laa > ent->localtime)
11944 			tim = laa - ftim;
11945 		else
11946 			tim = 0;
11947 		cbw = data * HPTS_USEC_IN_SEC;
11948 		if (tim > 0)
11949 			cbw /= tim;
11950 		else
11951 			cbw = 0;
11952 		rack_log_hybrid_bw(rack, th_ack, cbw, tim, data, HYBRID_LOG_BW_MEASURE, 0, ent);
11953 		/*
11954 		 * Check to see if we are freeing what we are pointing to send wise
11955 		 * if so be sure to NULL the pointer so we know we are no longer
11956 		 * set to anything.
11957 		 */
11958 		if (ent == rack->r_ctl.rc_last_sft)
11959 			rack->r_ctl.rc_last_sft = NULL;
11960 		/* Generate the log that the tcp_netflix call would have */
11961 		tcp_http_log_req_info(rack->rc_tp, ent,
11962 				      i, TCP_HTTP_REQ_LOG_FREED, 0, 0);
11963 		/* Free it and see if there is another one */
11964 		tcp_http_free_a_slot(rack->rc_tp, ent);
11965 		ent = tcp_http_find_a_req_that_is_completed_by(rack->rc_tp, th_ack, &i);
11966 	}
11967 }
11968 #endif
11969 
11970 
11971 /*
11972  * Return value of 1, we do not need to call rack_process_data().
11973  * return value of 0, rack_process_data can be called.
11974  * For ret_val if its 0 the TCP is locked, if its non-zero
11975  * its unlocked and probably unsafe to touch the TCB.
11976  */
11977 static int
11978 rack_process_ack(struct mbuf *m, struct tcphdr *th, struct socket *so,
11979     struct tcpcb *tp, struct tcpopt *to,
11980     uint32_t tiwin, int32_t tlen,
11981     int32_t * ofia, int32_t thflags, int32_t *ret_val)
11982 {
11983 	int32_t ourfinisacked = 0;
11984 	int32_t nsegs, acked_amount;
11985 	int32_t acked;
11986 	struct mbuf *mfree;
11987 	struct tcp_rack *rack;
11988 	int32_t under_pacing = 0;
11989 	int32_t recovery = 0;
11990 
11991 	INP_WLOCK_ASSERT(tptoinpcb(tp));
11992 
11993 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11994 	if (SEQ_GT(th->th_ack, tp->snd_max)) {
11995 		__ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val,
11996 				      &rack->r_ctl.challenge_ack_ts,
11997 				      &rack->r_ctl.challenge_ack_cnt);
11998 		rack->r_wanted_output = 1;
11999 		return (1);
12000 	}
12001 	if (rack->gp_ready &&
12002 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
12003 		under_pacing = 1;
12004 	}
12005 	if (SEQ_GEQ(th->th_ack, tp->snd_una) || to->to_nsacks) {
12006 		int in_rec, dup_ack_struck = 0;
12007 		int dsack_seen = 0, sacks_seen = 0;
12008 
12009 		in_rec = IN_FASTRECOVERY(tp->t_flags);
12010 		if (rack->rc_in_persist) {
12011 			tp->t_rxtshift = 0;
12012 			RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
12013 				      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
12014 		}
12015 
12016 		if ((th->th_ack == tp->snd_una) &&
12017 		    (tiwin == tp->snd_wnd) &&
12018 		    ((to->to_flags & TOF_SACK) == 0)) {
12019 			rack_strike_dupack(rack);
12020 			dup_ack_struck = 1;
12021 		}
12022 		rack_log_ack(tp, to, th, ((in_rec == 0) && IN_FASTRECOVERY(tp->t_flags)),
12023 			     dup_ack_struck, &dsack_seen, &sacks_seen);
12024 		if ((rack->sack_attack_disable > 0) &&
12025 		    (th->th_ack == tp->snd_una) &&
12026 		    (tiwin == tp->snd_wnd) &&
12027 		    (dsack_seen == 0) &&
12028 		    (sacks_seen > 0)) {
12029 			/*
12030 			 * If sacks have been disabled we may
12031 			 * want to strike a dup-ack "ignoring" the
12032 			 * sack as long as the sack was not a "dsack". Note
12033 			 * that if no sack is sent (TOF_SACK is off) then the
12034 			 * normal dsack code above rack_log_ack() would have
12035 			 * already struck. So this is just to catch the case
12036 			 * were we are ignoring sacks from this guy due to
12037 			 * it being a suspected attacker.
12038 			 */
12039 			rack_strike_dupack(rack);
12040 		}
12041 
12042 	}
12043 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
12044 		/*
12045 		 * Old ack, behind (or duplicate to) the last one rcv'd
12046 		 * Note: We mark reordering is occuring if its
12047 		 * less than and we have not closed our window.
12048 		 */
12049 		if (SEQ_LT(th->th_ack, tp->snd_una) && (sbspace(&so->so_rcv) > ctf_fixed_maxseg(tp))) {
12050 			rack->r_ctl.rc_reorder_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
12051 			if (rack->r_ctl.rc_reorder_ts == 0)
12052 				rack->r_ctl.rc_reorder_ts = 1;
12053 		}
12054 		return (0);
12055 	}
12056 	/*
12057 	 * If we reach this point, ACK is not a duplicate, i.e., it ACKs
12058 	 * something we sent.
12059 	 */
12060 	if (tp->t_flags & TF_NEEDSYN) {
12061 		/*
12062 		 * T/TCP: Connection was half-synchronized, and our SYN has
12063 		 * been ACK'd (so connection is now fully synchronized).  Go
12064 		 * to non-starred state, increment snd_una for ACK of SYN,
12065 		 * and check if we can do window scaling.
12066 		 */
12067 		tp->t_flags &= ~TF_NEEDSYN;
12068 		tp->snd_una++;
12069 		/* Do window scaling? */
12070 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
12071 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
12072 			tp->rcv_scale = tp->request_r_scale;
12073 			/* Send window already scaled. */
12074 		}
12075 	}
12076 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
12077 
12078 	acked = BYTES_THIS_ACK(tp, th);
12079 	if (acked) {
12080 		/*
12081 		 * Any time we move the cum-ack forward clear
12082 		 * keep-alive tied probe-not-answered. The
12083 		 * persists clears its own on entry.
12084 		 */
12085 		rack->probe_not_answered = 0;
12086 	}
12087 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
12088 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
12089 	/*
12090 	 * If we just performed our first retransmit, and the ACK arrives
12091 	 * within our recovery window, then it was a mistake to do the
12092 	 * retransmit in the first place.  Recover our original cwnd and
12093 	 * ssthresh, and proceed to transmit where we left off.
12094 	 */
12095 	if ((tp->t_flags & TF_PREVVALID) &&
12096 	    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
12097 		tp->t_flags &= ~TF_PREVVALID;
12098 		if (tp->t_rxtshift == 1 &&
12099 		    (int)(ticks - tp->t_badrxtwin) < 0)
12100 			rack_cong_signal(tp, CC_RTO_ERR, th->th_ack, __LINE__);
12101 	}
12102 	if (acked) {
12103 		/* assure we are not backed off */
12104 		tp->t_rxtshift = 0;
12105 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
12106 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
12107 		rack->rc_tlp_in_progress = 0;
12108 		rack->r_ctl.rc_tlp_cnt_out = 0;
12109 		/*
12110 		 * If it is the RXT timer we want to
12111 		 * stop it, so we can restart a TLP.
12112 		 */
12113 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
12114 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
12115 #ifdef TCP_REQUEST_TRK
12116 		rack_http_check_for_comp(rack, th->th_ack);
12117 #endif
12118 	}
12119 	/*
12120 	 * If we have a timestamp reply, update smoothed round trip time. If
12121 	 * no timestamp is present but transmit timer is running and timed
12122 	 * sequence number was acked, update smoothed round trip time. Since
12123 	 * we now have an rtt measurement, cancel the timer backoff (cf.,
12124 	 * Phil Karn's retransmit alg.). Recompute the initial retransmit
12125 	 * timer.
12126 	 *
12127 	 * Some boxes send broken timestamp replies during the SYN+ACK
12128 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
12129 	 * and blow up the retransmit timer.
12130 	 */
12131 	/*
12132 	 * If all outstanding data is acked, stop retransmit timer and
12133 	 * remember to restart (more output or persist). If there is more
12134 	 * data to be acked, restart retransmit timer, using current
12135 	 * (possibly backed-off) value.
12136 	 */
12137 	if (acked == 0) {
12138 		if (ofia)
12139 			*ofia = ourfinisacked;
12140 		return (0);
12141 	}
12142 	if (IN_RECOVERY(tp->t_flags)) {
12143 		if (SEQ_LT(th->th_ack, tp->snd_recover) &&
12144 		    (SEQ_LT(th->th_ack, tp->snd_max))) {
12145 			tcp_rack_partialack(tp);
12146 		} else {
12147 			rack_post_recovery(tp, th->th_ack);
12148 			recovery = 1;
12149 		}
12150 	}
12151 	/*
12152 	 * Let the congestion control algorithm update congestion control
12153 	 * related information. This typically means increasing the
12154 	 * congestion window.
12155 	 */
12156 	rack_ack_received(tp, rack, th->th_ack, nsegs, CC_ACK, recovery);
12157 	SOCKBUF_LOCK(&so->so_snd);
12158 	acked_amount = min(acked, (int)sbavail(&so->so_snd));
12159 	tp->snd_wnd -= acked_amount;
12160 	mfree = sbcut_locked(&so->so_snd, acked_amount);
12161 	if ((sbused(&so->so_snd) == 0) &&
12162 	    (acked > acked_amount) &&
12163 	    (tp->t_state >= TCPS_FIN_WAIT_1) &&
12164 	    (tp->t_flags & TF_SENTFIN)) {
12165 		/*
12166 		 * We must be sure our fin
12167 		 * was sent and acked (we can be
12168 		 * in FIN_WAIT_1 without having
12169 		 * sent the fin).
12170 		 */
12171 		ourfinisacked = 1;
12172 	}
12173 	tp->snd_una = th->th_ack;
12174 	/* wakeups? */
12175 	if (acked_amount && sbavail(&so->so_snd))
12176 		rack_adjust_sendmap_head(rack, &so->so_snd);
12177 	rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
12178 	/* NB: sowwakeup_locked() does an implicit unlock. */
12179 	sowwakeup_locked(so);
12180 	/* now check the rxt clamps */
12181 	if ((recovery == 1) &&
12182 	    (rack->excess_rxt_on) &&
12183 	    (rack->r_cwnd_was_clamped == 0))  {
12184 		do_rack_excess_rxt(tp, rack);
12185 	} else if (rack->r_cwnd_was_clamped)
12186 		do_rack_check_for_unclamp(tp, rack);
12187 	m_freem(mfree);
12188 	if (SEQ_GT(tp->snd_una, tp->snd_recover))
12189 		tp->snd_recover = tp->snd_una;
12190 
12191 	if (SEQ_LT(tp->snd_nxt, tp->snd_una)) {
12192 		tp->snd_nxt = tp->snd_una;
12193 	}
12194 	if (under_pacing &&
12195 	    (rack->use_fixed_rate == 0) &&
12196 	    (rack->in_probe_rtt == 0) &&
12197 	    rack->rc_gp_dyn_mul &&
12198 	    rack->rc_always_pace) {
12199 		/* Check if we are dragging bottom */
12200 		rack_check_bottom_drag(tp, rack, so);
12201 	}
12202 	if (tp->snd_una == tp->snd_max) {
12203 		/* Nothing left outstanding */
12204 		tp->t_flags &= ~TF_PREVVALID;
12205 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
12206 		rack->r_ctl.retran_during_recovery = 0;
12207 		rack->r_ctl.dsack_byte_cnt = 0;
12208 		if (rack->r_ctl.rc_went_idle_time == 0)
12209 			rack->r_ctl.rc_went_idle_time = 1;
12210 		rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
12211 		if (sbavail(&tptosocket(tp)->so_snd) == 0)
12212 			tp->t_acktime = 0;
12213 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
12214 		rack->rc_suspicious = 0;
12215 		/* Set need output so persist might get set */
12216 		rack->r_wanted_output = 1;
12217 		sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
12218 		if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
12219 		    (sbavail(&so->so_snd) == 0) &&
12220 		    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
12221 			/*
12222 			 * The socket was gone and the
12223 			 * peer sent data (now or in the past), time to
12224 			 * reset him.
12225 			 */
12226 			*ret_val = 1;
12227 			/* tcp_close will kill the inp pre-log the Reset */
12228 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
12229 			tp = tcp_close(tp);
12230 			ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, tlen);
12231 			return (1);
12232 		}
12233 	}
12234 	if (ofia)
12235 		*ofia = ourfinisacked;
12236 	return (0);
12237 }
12238 
12239 
12240 static void
12241 rack_log_collapse(struct tcp_rack *rack, uint32_t cnt, uint32_t split, uint32_t out, int line,
12242 		  int dir, uint32_t flags, struct rack_sendmap *rsm)
12243 {
12244 	if (tcp_bblogging_on(rack->rc_tp)) {
12245 		union tcp_log_stackspecific log;
12246 		struct timeval tv;
12247 
12248 		memset(&log, 0, sizeof(log));
12249 		log.u_bbr.flex1 = cnt;
12250 		log.u_bbr.flex2 = split;
12251 		log.u_bbr.flex3 = out;
12252 		log.u_bbr.flex4 = line;
12253 		log.u_bbr.flex5 = rack->r_must_retran;
12254 		log.u_bbr.flex6 = flags;
12255 		log.u_bbr.flex7 = rack->rc_has_collapsed;
12256 		log.u_bbr.flex8 = dir;	/*
12257 					 * 1 is collapsed, 0 is uncollapsed,
12258 					 * 2 is log of a rsm being marked, 3 is a split.
12259 					 */
12260 		if (rsm == NULL)
12261 			log.u_bbr.rttProp = 0;
12262 		else
12263 			log.u_bbr.rttProp = (uint64_t)rsm;
12264 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
12265 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
12266 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
12267 		    &rack->rc_inp->inp_socket->so_rcv,
12268 		    &rack->rc_inp->inp_socket->so_snd,
12269 		    TCP_RACK_LOG_COLLAPSE, 0,
12270 		    0, &log, false, &tv);
12271 	}
12272 }
12273 
12274 static void
12275 rack_collapsed_window(struct tcp_rack *rack, uint32_t out, tcp_seq th_ack, int line)
12276 {
12277 	/*
12278 	 * Here all we do is mark the collapsed point and set the flag.
12279 	 * This may happen again and again, but there is no
12280 	 * sense splitting our map until we know where the
12281 	 * peer finally lands in the collapse.
12282 	 */
12283 	tcp_trace_point(rack->rc_tp, TCP_TP_COLLAPSED_WND);
12284 	if ((rack->rc_has_collapsed == 0) ||
12285 	    (rack->r_ctl.last_collapse_point != (th_ack + rack->rc_tp->snd_wnd)))
12286 		counter_u64_add(rack_collapsed_win_seen, 1);
12287 	rack->r_ctl.last_collapse_point = th_ack + rack->rc_tp->snd_wnd;
12288 	rack->r_ctl.high_collapse_point = rack->rc_tp->snd_max;
12289 	rack->rc_has_collapsed = 1;
12290 	rack->r_collapse_point_valid = 1;
12291 	rack_log_collapse(rack, 0, th_ack, rack->r_ctl.last_collapse_point, line, 1, 0, NULL);
12292 }
12293 
12294 static void
12295 rack_un_collapse_window(struct tcp_rack *rack, int line)
12296 {
12297 	struct rack_sendmap *nrsm, *rsm;
12298 	int cnt = 0, split = 0;
12299 	int insret __diagused;
12300 
12301 
12302 	tcp_trace_point(rack->rc_tp, TCP_TP_COLLAPSED_WND);
12303 	rack->rc_has_collapsed = 0;
12304 	rsm = tqhash_find(rack->r_ctl.tqh, rack->r_ctl.last_collapse_point);
12305 	if (rsm == NULL) {
12306 		/* Nothing to do maybe the peer ack'ed it all */
12307 		rack_log_collapse(rack, 0, 0, ctf_outstanding(rack->rc_tp), line, 0, 0, NULL);
12308 		return;
12309 	}
12310 	/* Now do we need to split this one? */
12311 	if (SEQ_GT(rack->r_ctl.last_collapse_point, rsm->r_start)) {
12312 		rack_log_collapse(rack, rsm->r_start, rsm->r_end,
12313 				  rack->r_ctl.last_collapse_point, line, 3, rsm->r_flags, rsm);
12314 		nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
12315 		if (nrsm == NULL) {
12316 			/* We can't get a rsm, mark all? */
12317 			nrsm = rsm;
12318 			goto no_split;
12319 		}
12320 		/* Clone it */
12321 		split = 1;
12322 		rack_clone_rsm(rack, nrsm, rsm, rack->r_ctl.last_collapse_point);
12323 #ifndef INVARIANTS
12324 		(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
12325 #else
12326 		if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
12327 			panic("Insert in rb tree of %p fails ret:%d rack:%p rsm:%p",
12328 			      nrsm, insret, rack, rsm);
12329 		}
12330 #endif
12331 		rack_log_map_chg(rack->rc_tp, rack, NULL, rsm, nrsm, MAP_SPLIT,
12332 				 rack->r_ctl.last_collapse_point, __LINE__);
12333 		if (rsm->r_in_tmap) {
12334 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
12335 			nrsm->r_in_tmap = 1;
12336 		}
12337 		/*
12338 		 * Set in the new RSM as the
12339 		 * collapsed starting point
12340 		 */
12341 		rsm = nrsm;
12342 	}
12343 
12344 no_split:
12345 	TQHASH_FOREACH_FROM(nrsm, rack->r_ctl.tqh, rsm)  {
12346 		cnt++;
12347 		nrsm->r_flags |= RACK_RWND_COLLAPSED;
12348 		rack_log_collapse(rack, nrsm->r_start, nrsm->r_end, 0, line, 4, nrsm->r_flags, nrsm);
12349 		cnt++;
12350 	}
12351 	if (cnt) {
12352 		counter_u64_add(rack_collapsed_win, 1);
12353 	}
12354 	rack_log_collapse(rack, cnt, split, ctf_outstanding(rack->rc_tp), line, 0, 0, NULL);
12355 }
12356 
12357 static void
12358 rack_handle_delayed_ack(struct tcpcb *tp, struct tcp_rack *rack,
12359 			int32_t tlen, int32_t tfo_syn)
12360 {
12361 	if (DELAY_ACK(tp, tlen) || tfo_syn) {
12362 		rack_timer_cancel(tp, rack,
12363 				  rack->r_ctl.rc_rcvtime, __LINE__);
12364 		tp->t_flags |= TF_DELACK;
12365 	} else {
12366 		rack->r_wanted_output = 1;
12367 		tp->t_flags |= TF_ACKNOW;
12368 	}
12369 }
12370 
12371 static void
12372 rack_validate_fo_sendwin_up(struct tcpcb *tp, struct tcp_rack *rack)
12373 {
12374 	/*
12375 	 * If fast output is in progress, lets validate that
12376 	 * the new window did not shrink on us and make it
12377 	 * so fast output should end.
12378 	 */
12379 	if (rack->r_fast_output) {
12380 		uint32_t out;
12381 
12382 		/*
12383 		 * Calculate what we will send if left as is
12384 		 * and compare that to our send window.
12385 		 */
12386 		out = ctf_outstanding(tp);
12387 		if ((out + rack->r_ctl.fsb.left_to_send) > tp->snd_wnd) {
12388 			/* ok we have an issue */
12389 			if (out >= tp->snd_wnd) {
12390 				/* Turn off fast output the window is met or collapsed */
12391 				rack->r_fast_output = 0;
12392 			} else {
12393 				/* we have some room left */
12394 				rack->r_ctl.fsb.left_to_send = tp->snd_wnd - out;
12395 				if (rack->r_ctl.fsb.left_to_send < ctf_fixed_maxseg(tp)) {
12396 					/* If not at least 1 full segment never mind */
12397 					rack->r_fast_output = 0;
12398 				}
12399 			}
12400 		}
12401 	}
12402 }
12403 
12404 
12405 /*
12406  * Return value of 1, the TCB is unlocked and most
12407  * likely gone, return value of 0, the TCP is still
12408  * locked.
12409  */
12410 static int
12411 rack_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so,
12412     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
12413     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
12414 {
12415 	/*
12416 	 * Update window information. Don't look at window if no ACK: TAC's
12417 	 * send garbage on first SYN.
12418 	 */
12419 	int32_t nsegs;
12420 	int32_t tfo_syn;
12421 	struct tcp_rack *rack;
12422 
12423 	INP_WLOCK_ASSERT(tptoinpcb(tp));
12424 
12425 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12426 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
12427 	if ((thflags & TH_ACK) &&
12428 	    (SEQ_LT(tp->snd_wl1, th->th_seq) ||
12429 	    (tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) ||
12430 	    (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) {
12431 		/* keep track of pure window updates */
12432 		if (tlen == 0 &&
12433 		    tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd)
12434 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
12435 		tp->snd_wnd = tiwin;
12436 		rack_validate_fo_sendwin_up(tp, rack);
12437 		tp->snd_wl1 = th->th_seq;
12438 		tp->snd_wl2 = th->th_ack;
12439 		if (tp->snd_wnd > tp->max_sndwnd)
12440 			tp->max_sndwnd = tp->snd_wnd;
12441 		rack->r_wanted_output = 1;
12442 	} else if (thflags & TH_ACK) {
12443 		if ((tp->snd_wl2 == th->th_ack) && (tiwin < tp->snd_wnd)) {
12444 			tp->snd_wnd = tiwin;
12445 			rack_validate_fo_sendwin_up(tp, rack);
12446 			tp->snd_wl1 = th->th_seq;
12447 			tp->snd_wl2 = th->th_ack;
12448 		}
12449 	}
12450 	if (tp->snd_wnd < ctf_outstanding(tp))
12451 		/* The peer collapsed the window */
12452 		rack_collapsed_window(rack, ctf_outstanding(tp), th->th_ack, __LINE__);
12453 	else if (rack->rc_has_collapsed)
12454 		rack_un_collapse_window(rack, __LINE__);
12455 	if ((rack->r_collapse_point_valid) &&
12456 	    (SEQ_GT(th->th_ack, rack->r_ctl.high_collapse_point)))
12457 		rack->r_collapse_point_valid = 0;
12458 	/* Was persist timer active and now we have window space? */
12459 	if ((rack->rc_in_persist != 0) &&
12460 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
12461 				rack->r_ctl.rc_pace_min_segs))) {
12462 		rack_exit_persist(tp, rack, rack->r_ctl.rc_rcvtime);
12463 		tp->snd_nxt = tp->snd_max;
12464 		/* Make sure we output to start the timer */
12465 		rack->r_wanted_output = 1;
12466 	}
12467 	/* Do we enter persists? */
12468 	if ((rack->rc_in_persist == 0) &&
12469 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
12470 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
12471 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
12472 	    sbavail(&tptosocket(tp)->so_snd) &&
12473 	    (sbavail(&tptosocket(tp)->so_snd) > tp->snd_wnd)) {
12474 		/*
12475 		 * Here the rwnd is less than
12476 		 * the pacing size, we are established,
12477 		 * nothing is outstanding, and there is
12478 		 * data to send. Enter persists.
12479 		 */
12480 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime, tp->snd_una);
12481 	}
12482 	if (tp->t_flags2 & TF2_DROP_AF_DATA) {
12483 		m_freem(m);
12484 		return (0);
12485 	}
12486 	/*
12487 	 * don't process the URG bit, ignore them drag
12488 	 * along the up.
12489 	 */
12490 	tp->rcv_up = tp->rcv_nxt;
12491 
12492 	/*
12493 	 * Process the segment text, merging it into the TCP sequencing
12494 	 * queue, and arranging for acknowledgment of receipt if necessary.
12495 	 * This process logically involves adjusting tp->rcv_wnd as data is
12496 	 * presented to the user (this happens in tcp_usrreq.c, case
12497 	 * PRU_RCVD).  If a FIN has already been received on this connection
12498 	 * then we just ignore the text.
12499 	 */
12500 	tfo_syn = ((tp->t_state == TCPS_SYN_RECEIVED) &&
12501 		   IS_FASTOPEN(tp->t_flags));
12502 	if ((tlen || (thflags & TH_FIN) || (tfo_syn && tlen > 0)) &&
12503 	    TCPS_HAVERCVDFIN(tp->t_state) == 0) {
12504 		tcp_seq save_start = th->th_seq;
12505 		tcp_seq save_rnxt  = tp->rcv_nxt;
12506 		int     save_tlen  = tlen;
12507 
12508 		m_adj(m, drop_hdrlen);	/* delayed header drop */
12509 		/*
12510 		 * Insert segment which includes th into TCP reassembly
12511 		 * queue with control block tp.  Set thflags to whether
12512 		 * reassembly now includes a segment with FIN.  This handles
12513 		 * the common case inline (segment is the next to be
12514 		 * received on an established connection, and the queue is
12515 		 * empty), avoiding linkage into and removal from the queue
12516 		 * and repetition of various conversions. Set DELACK for
12517 		 * segments received in order, but ack immediately when
12518 		 * segments are out of order (so fast retransmit can work).
12519 		 */
12520 		if (th->th_seq == tp->rcv_nxt &&
12521 		    SEGQ_EMPTY(tp) &&
12522 		    (TCPS_HAVEESTABLISHED(tp->t_state) ||
12523 		    tfo_syn)) {
12524 #ifdef NETFLIX_SB_LIMITS
12525 			u_int mcnt, appended;
12526 
12527 			if (so->so_rcv.sb_shlim) {
12528 				mcnt = m_memcnt(m);
12529 				appended = 0;
12530 				if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
12531 				    CFO_NOSLEEP, NULL) == false) {
12532 					counter_u64_add(tcp_sb_shlim_fails, 1);
12533 					m_freem(m);
12534 					return (0);
12535 				}
12536 			}
12537 #endif
12538 			rack_handle_delayed_ack(tp, rack, tlen, tfo_syn);
12539 			tp->rcv_nxt += tlen;
12540 			if (tlen &&
12541 			    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
12542 			    (tp->t_fbyte_in == 0)) {
12543 				tp->t_fbyte_in = ticks;
12544 				if (tp->t_fbyte_in == 0)
12545 					tp->t_fbyte_in = 1;
12546 				if (tp->t_fbyte_out && tp->t_fbyte_in)
12547 					tp->t_flags2 |= TF2_FBYTES_COMPLETE;
12548 			}
12549 			thflags = tcp_get_flags(th) & TH_FIN;
12550 			KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
12551 			KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
12552 			SOCKBUF_LOCK(&so->so_rcv);
12553 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
12554 				m_freem(m);
12555 			} else
12556 #ifdef NETFLIX_SB_LIMITS
12557 				appended =
12558 #endif
12559 					sbappendstream_locked(&so->so_rcv, m, 0);
12560 
12561 			rack_log_wakeup(tp,rack, &so->so_rcv, tlen, 1);
12562 			/* NB: sorwakeup_locked() does an implicit unlock. */
12563 			sorwakeup_locked(so);
12564 #ifdef NETFLIX_SB_LIMITS
12565 			if (so->so_rcv.sb_shlim && appended != mcnt)
12566 				counter_fo_release(so->so_rcv.sb_shlim,
12567 				    mcnt - appended);
12568 #endif
12569 		} else {
12570 			/*
12571 			 * XXX: Due to the header drop above "th" is
12572 			 * theoretically invalid by now.  Fortunately
12573 			 * m_adj() doesn't actually frees any mbufs when
12574 			 * trimming from the head.
12575 			 */
12576 			tcp_seq temp = save_start;
12577 
12578 			thflags = tcp_reass(tp, th, &temp, &tlen, m);
12579 			tp->t_flags |= TF_ACKNOW;
12580 			if (tp->t_flags & TF_WAKESOR) {
12581 				tp->t_flags &= ~TF_WAKESOR;
12582 				/* NB: sorwakeup_locked() does an implicit unlock. */
12583 				sorwakeup_locked(so);
12584 			}
12585 		}
12586 		if ((tp->t_flags & TF_SACK_PERMIT) &&
12587 		    (save_tlen > 0) &&
12588 		    TCPS_HAVEESTABLISHED(tp->t_state)) {
12589 			if ((tlen == 0) && (SEQ_LT(save_start, save_rnxt))) {
12590 				/*
12591 				 * DSACK actually handled in the fastpath
12592 				 * above.
12593 				 */
12594 				tcp_update_sack_list(tp, save_start,
12595 				    save_start + save_tlen);
12596 			} else if ((tlen > 0) && SEQ_GT(tp->rcv_nxt, save_rnxt)) {
12597 				if ((tp->rcv_numsacks >= 1) &&
12598 				    (tp->sackblks[0].end == save_start)) {
12599 					/*
12600 					 * Partial overlap, recorded at todrop
12601 					 * above.
12602 					 */
12603 					tcp_update_sack_list(tp,
12604 					    tp->sackblks[0].start,
12605 					    tp->sackblks[0].end);
12606 				} else {
12607 					tcp_update_dsack_list(tp, save_start,
12608 					    save_start + save_tlen);
12609 				}
12610 			} else if (tlen >= save_tlen) {
12611 				/* Update of sackblks. */
12612 				tcp_update_dsack_list(tp, save_start,
12613 				    save_start + save_tlen);
12614 			} else if (tlen > 0) {
12615 				tcp_update_dsack_list(tp, save_start,
12616 				    save_start + tlen);
12617 			}
12618 		}
12619 	} else {
12620 		m_freem(m);
12621 		thflags &= ~TH_FIN;
12622 	}
12623 
12624 	/*
12625 	 * If FIN is received ACK the FIN and let the user know that the
12626 	 * connection is closing.
12627 	 */
12628 	if (thflags & TH_FIN) {
12629 		if (TCPS_HAVERCVDFIN(tp->t_state) == 0) {
12630 			/* The socket upcall is handled by socantrcvmore. */
12631 			socantrcvmore(so);
12632 			/*
12633 			 * If connection is half-synchronized (ie NEEDSYN
12634 			 * flag on) then delay ACK, so it may be piggybacked
12635 			 * when SYN is sent. Otherwise, since we received a
12636 			 * FIN then no more input can be expected, send ACK
12637 			 * now.
12638 			 */
12639 			if (tp->t_flags & TF_NEEDSYN) {
12640 				rack_timer_cancel(tp, rack,
12641 				    rack->r_ctl.rc_rcvtime, __LINE__);
12642 				tp->t_flags |= TF_DELACK;
12643 			} else {
12644 				tp->t_flags |= TF_ACKNOW;
12645 			}
12646 			tp->rcv_nxt++;
12647 		}
12648 		switch (tp->t_state) {
12649 			/*
12650 			 * In SYN_RECEIVED and ESTABLISHED STATES enter the
12651 			 * CLOSE_WAIT state.
12652 			 */
12653 		case TCPS_SYN_RECEIVED:
12654 			tp->t_starttime = ticks;
12655 			/* FALLTHROUGH */
12656 		case TCPS_ESTABLISHED:
12657 			rack_timer_cancel(tp, rack,
12658 			    rack->r_ctl.rc_rcvtime, __LINE__);
12659 			tcp_state_change(tp, TCPS_CLOSE_WAIT);
12660 			break;
12661 
12662 			/*
12663 			 * If still in FIN_WAIT_1 STATE FIN has not been
12664 			 * acked so enter the CLOSING state.
12665 			 */
12666 		case TCPS_FIN_WAIT_1:
12667 			rack_timer_cancel(tp, rack,
12668 			    rack->r_ctl.rc_rcvtime, __LINE__);
12669 			tcp_state_change(tp, TCPS_CLOSING);
12670 			break;
12671 
12672 			/*
12673 			 * In FIN_WAIT_2 state enter the TIME_WAIT state,
12674 			 * starting the time-wait timer, turning off the
12675 			 * other standard timers.
12676 			 */
12677 		case TCPS_FIN_WAIT_2:
12678 			rack_timer_cancel(tp, rack,
12679 			    rack->r_ctl.rc_rcvtime, __LINE__);
12680 			tcp_twstart(tp);
12681 			return (1);
12682 		}
12683 	}
12684 	/*
12685 	 * Return any desired output.
12686 	 */
12687 	if ((tp->t_flags & TF_ACKNOW) ||
12688 	    (sbavail(&so->so_snd) > (tp->snd_max - tp->snd_una))) {
12689 		rack->r_wanted_output = 1;
12690 	}
12691 	return (0);
12692 }
12693 
12694 /*
12695  * Here nothing is really faster, its just that we
12696  * have broken out the fast-data path also just like
12697  * the fast-ack.
12698  */
12699 static int
12700 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th, struct socket *so,
12701     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12702     uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos)
12703 {
12704 	int32_t nsegs;
12705 	int32_t newsize = 0;	/* automatic sockbuf scaling */
12706 	struct tcp_rack *rack;
12707 #ifdef NETFLIX_SB_LIMITS
12708 	u_int mcnt, appended;
12709 #endif
12710 
12711 	/*
12712 	 * If last ACK falls within this segment's sequence numbers, record
12713 	 * the timestamp. NOTE that the test is modified according to the
12714 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
12715 	 */
12716 	if (__predict_false(th->th_seq != tp->rcv_nxt)) {
12717 		return (0);
12718 	}
12719 	if (__predict_false(tp->snd_nxt != tp->snd_max)) {
12720 		return (0);
12721 	}
12722 	if (tiwin && tiwin != tp->snd_wnd) {
12723 		return (0);
12724 	}
12725 	if (__predict_false((tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN)))) {
12726 		return (0);
12727 	}
12728 	if (__predict_false((to->to_flags & TOF_TS) &&
12729 	    (TSTMP_LT(to->to_tsval, tp->ts_recent)))) {
12730 		return (0);
12731 	}
12732 	if (__predict_false((th->th_ack != tp->snd_una))) {
12733 		return (0);
12734 	}
12735 	if (__predict_false(tlen > sbspace(&so->so_rcv))) {
12736 		return (0);
12737 	}
12738 	if ((to->to_flags & TOF_TS) != 0 &&
12739 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
12740 		tp->ts_recent_age = tcp_ts_getticks();
12741 		tp->ts_recent = to->to_tsval;
12742 	}
12743 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12744 	/*
12745 	 * This is a pure, in-sequence data packet with nothing on the
12746 	 * reassembly queue and we have enough buffer space to take it.
12747 	 */
12748 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
12749 
12750 #ifdef NETFLIX_SB_LIMITS
12751 	if (so->so_rcv.sb_shlim) {
12752 		mcnt = m_memcnt(m);
12753 		appended = 0;
12754 		if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
12755 		    CFO_NOSLEEP, NULL) == false) {
12756 			counter_u64_add(tcp_sb_shlim_fails, 1);
12757 			m_freem(m);
12758 			return (1);
12759 		}
12760 	}
12761 #endif
12762 	/* Clean receiver SACK report if present */
12763 	if (tp->rcv_numsacks)
12764 		tcp_clean_sackreport(tp);
12765 	KMOD_TCPSTAT_INC(tcps_preddat);
12766 	tp->rcv_nxt += tlen;
12767 	if (tlen &&
12768 	    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
12769 	    (tp->t_fbyte_in == 0)) {
12770 		tp->t_fbyte_in = ticks;
12771 		if (tp->t_fbyte_in == 0)
12772 			tp->t_fbyte_in = 1;
12773 		if (tp->t_fbyte_out && tp->t_fbyte_in)
12774 			tp->t_flags2 |= TF2_FBYTES_COMPLETE;
12775 	}
12776 	/*
12777 	 * Pull snd_wl1 up to prevent seq wrap relative to th_seq.
12778 	 */
12779 	tp->snd_wl1 = th->th_seq;
12780 	/*
12781 	 * Pull rcv_up up to prevent seq wrap relative to rcv_nxt.
12782 	 */
12783 	tp->rcv_up = tp->rcv_nxt;
12784 	KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
12785 	KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
12786 	newsize = tcp_autorcvbuf(m, th, so, tp, tlen);
12787 
12788 	/* Add data to socket buffer. */
12789 	SOCKBUF_LOCK(&so->so_rcv);
12790 	if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
12791 		m_freem(m);
12792 	} else {
12793 		/*
12794 		 * Set new socket buffer size. Give up when limit is
12795 		 * reached.
12796 		 */
12797 		if (newsize)
12798 			if (!sbreserve_locked(so, SO_RCV, newsize, NULL))
12799 				so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
12800 		m_adj(m, drop_hdrlen);	/* delayed header drop */
12801 #ifdef NETFLIX_SB_LIMITS
12802 		appended =
12803 #endif
12804 			sbappendstream_locked(&so->so_rcv, m, 0);
12805 		ctf_calc_rwin(so, tp);
12806 	}
12807 	rack_log_wakeup(tp,rack, &so->so_rcv, tlen, 1);
12808 	/* NB: sorwakeup_locked() does an implicit unlock. */
12809 	sorwakeup_locked(so);
12810 #ifdef NETFLIX_SB_LIMITS
12811 	if (so->so_rcv.sb_shlim && mcnt != appended)
12812 		counter_fo_release(so->so_rcv.sb_shlim, mcnt - appended);
12813 #endif
12814 	rack_handle_delayed_ack(tp, rack, tlen, 0);
12815 	if (tp->snd_una == tp->snd_max)
12816 		sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
12817 	return (1);
12818 }
12819 
12820 /*
12821  * This subfunction is used to try to highly optimize the
12822  * fast path. We again allow window updates that are
12823  * in sequence to remain in the fast-path. We also add
12824  * in the __predict's to attempt to help the compiler.
12825  * Note that if we return a 0, then we can *not* process
12826  * it and the caller should push the packet into the
12827  * slow-path.
12828  */
12829 static int
12830 rack_fastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
12831     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12832     uint32_t tiwin, int32_t nxt_pkt, uint32_t cts)
12833 {
12834 	int32_t acked;
12835 	int32_t nsegs;
12836 	int32_t under_pacing = 0;
12837 	struct tcp_rack *rack;
12838 
12839 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
12840 		/* Old ack, behind (or duplicate to) the last one rcv'd */
12841 		return (0);
12842 	}
12843 	if (__predict_false(SEQ_GT(th->th_ack, tp->snd_max))) {
12844 		/* Above what we have sent? */
12845 		return (0);
12846 	}
12847 	if (__predict_false(tp->snd_nxt != tp->snd_max)) {
12848 		/* We are retransmitting */
12849 		return (0);
12850 	}
12851 	if (__predict_false(tiwin == 0)) {
12852 		/* zero window */
12853 		return (0);
12854 	}
12855 	if (__predict_false(tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN))) {
12856 		/* We need a SYN or a FIN, unlikely.. */
12857 		return (0);
12858 	}
12859 	if ((to->to_flags & TOF_TS) && __predict_false(TSTMP_LT(to->to_tsval, tp->ts_recent))) {
12860 		/* Timestamp is behind .. old ack with seq wrap? */
12861 		return (0);
12862 	}
12863 	if (__predict_false(IN_RECOVERY(tp->t_flags))) {
12864 		/* Still recovering */
12865 		return (0);
12866 	}
12867 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12868 	if (rack->r_ctl.rc_sacked) {
12869 		/* We have sack holes on our scoreboard */
12870 		return (0);
12871 	}
12872 	/* Ok if we reach here, we can process a fast-ack */
12873 	if (rack->gp_ready &&
12874 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
12875 		under_pacing = 1;
12876 	}
12877 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
12878 	rack_log_ack(tp, to, th, 0, 0, NULL, NULL);
12879 	/* Did the window get updated? */
12880 	if (tiwin != tp->snd_wnd) {
12881 		tp->snd_wnd = tiwin;
12882 		rack_validate_fo_sendwin_up(tp, rack);
12883 		tp->snd_wl1 = th->th_seq;
12884 		if (tp->snd_wnd > tp->max_sndwnd)
12885 			tp->max_sndwnd = tp->snd_wnd;
12886 	}
12887 	/* Do we exit persists? */
12888 	if ((rack->rc_in_persist != 0) &&
12889 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
12890 			       rack->r_ctl.rc_pace_min_segs))) {
12891 		rack_exit_persist(tp, rack, cts);
12892 	}
12893 	/* Do we enter persists? */
12894 	if ((rack->rc_in_persist == 0) &&
12895 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
12896 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
12897 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
12898 	    sbavail(&tptosocket(tp)->so_snd) &&
12899 	    (sbavail(&tptosocket(tp)->so_snd) > tp->snd_wnd)) {
12900 		/*
12901 		 * Here the rwnd is less than
12902 		 * the pacing size, we are established,
12903 		 * nothing is outstanding, and there is
12904 		 * data to send. Enter persists.
12905 		 */
12906 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime, th->th_ack);
12907 	}
12908 	/*
12909 	 * If last ACK falls within this segment's sequence numbers, record
12910 	 * the timestamp. NOTE that the test is modified according to the
12911 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
12912 	 */
12913 	if ((to->to_flags & TOF_TS) != 0 &&
12914 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
12915 		tp->ts_recent_age = tcp_ts_getticks();
12916 		tp->ts_recent = to->to_tsval;
12917 	}
12918 	/*
12919 	 * This is a pure ack for outstanding data.
12920 	 */
12921 	KMOD_TCPSTAT_INC(tcps_predack);
12922 
12923 	/*
12924 	 * "bad retransmit" recovery.
12925 	 */
12926 	if ((tp->t_flags & TF_PREVVALID) &&
12927 	    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
12928 		tp->t_flags &= ~TF_PREVVALID;
12929 		if (tp->t_rxtshift == 1 &&
12930 		    (int)(ticks - tp->t_badrxtwin) < 0)
12931 			rack_cong_signal(tp, CC_RTO_ERR, th->th_ack, __LINE__);
12932 	}
12933 	/*
12934 	 * Recalculate the transmit timer / rtt.
12935 	 *
12936 	 * Some boxes send broken timestamp replies during the SYN+ACK
12937 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
12938 	 * and blow up the retransmit timer.
12939 	 */
12940 	acked = BYTES_THIS_ACK(tp, th);
12941 
12942 #ifdef TCP_HHOOK
12943 	/* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */
12944 	hhook_run_tcp_est_in(tp, th, to);
12945 #endif
12946 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
12947 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
12948 	if (acked) {
12949 		struct mbuf *mfree;
12950 
12951 		rack_ack_received(tp, rack, th->th_ack, nsegs, CC_ACK, 0);
12952 		SOCKBUF_LOCK(&so->so_snd);
12953 		mfree = sbcut_locked(&so->so_snd, acked);
12954 		tp->snd_una = th->th_ack;
12955 		/* Note we want to hold the sb lock through the sendmap adjust */
12956 		rack_adjust_sendmap_head(rack, &so->so_snd);
12957 		/* Wake up the socket if we have room to write more */
12958 		rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
12959 		sowwakeup_locked(so);
12960 		m_freem(mfree);
12961 		tp->t_rxtshift = 0;
12962 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
12963 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
12964 		rack->rc_tlp_in_progress = 0;
12965 		rack->r_ctl.rc_tlp_cnt_out = 0;
12966 		/*
12967 		 * If it is the RXT timer we want to
12968 		 * stop it, so we can restart a TLP.
12969 		 */
12970 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
12971 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
12972 
12973 #ifdef TCP_REQUEST_TRK
12974 		rack_http_check_for_comp(rack, th->th_ack);
12975 #endif
12976 	}
12977 	/*
12978 	 * Let the congestion control algorithm update congestion control
12979 	 * related information. This typically means increasing the
12980 	 * congestion window.
12981 	 */
12982 	if (tp->snd_wnd < ctf_outstanding(tp)) {
12983 		/* The peer collapsed the window */
12984 		rack_collapsed_window(rack, ctf_outstanding(tp), th->th_ack, __LINE__);
12985 	} else if (rack->rc_has_collapsed)
12986 		rack_un_collapse_window(rack, __LINE__);
12987 	if ((rack->r_collapse_point_valid) &&
12988 	    (SEQ_GT(tp->snd_una, rack->r_ctl.high_collapse_point)))
12989 		rack->r_collapse_point_valid = 0;
12990 	/*
12991 	 * Pull snd_wl2 up to prevent seq wrap relative to th_ack.
12992 	 */
12993 	tp->snd_wl2 = th->th_ack;
12994 	tp->t_dupacks = 0;
12995 	m_freem(m);
12996 	/* ND6_HINT(tp);	 *//* Some progress has been made. */
12997 
12998 	/*
12999 	 * If all outstanding data are acked, stop retransmit timer,
13000 	 * otherwise restart timer using current (possibly backed-off)
13001 	 * value. If process is waiting for space, wakeup/selwakeup/signal.
13002 	 * If data are ready to send, let tcp_output decide between more
13003 	 * output or persist.
13004 	 */
13005 	if (under_pacing &&
13006 	    (rack->use_fixed_rate == 0) &&
13007 	    (rack->in_probe_rtt == 0) &&
13008 	    rack->rc_gp_dyn_mul &&
13009 	    rack->rc_always_pace) {
13010 		/* Check if we are dragging bottom */
13011 		rack_check_bottom_drag(tp, rack, so);
13012 	}
13013 	if (tp->snd_una == tp->snd_max) {
13014 		tp->t_flags &= ~TF_PREVVALID;
13015 		rack->r_ctl.retran_during_recovery = 0;
13016 		rack->rc_suspicious = 0;
13017 		rack->r_ctl.dsack_byte_cnt = 0;
13018 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
13019 		if (rack->r_ctl.rc_went_idle_time == 0)
13020 			rack->r_ctl.rc_went_idle_time = 1;
13021 		rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
13022 		if (sbavail(&tptosocket(tp)->so_snd) == 0)
13023 			tp->t_acktime = 0;
13024 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13025 	}
13026 	if (acked && rack->r_fast_output)
13027 		rack_gain_for_fastoutput(rack, tp, so, (uint32_t)acked);
13028 	if (sbavail(&so->so_snd)) {
13029 		rack->r_wanted_output = 1;
13030 	}
13031 	return (1);
13032 }
13033 
13034 /*
13035  * Return value of 1, the TCB is unlocked and most
13036  * likely gone, return value of 0, the TCP is still
13037  * locked.
13038  */
13039 static int
13040 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th, struct socket *so,
13041     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13042     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13043 {
13044 	int32_t ret_val = 0;
13045 	int32_t todrop;
13046 	int32_t ourfinisacked = 0;
13047 	struct tcp_rack *rack;
13048 
13049 	INP_WLOCK_ASSERT(tptoinpcb(tp));
13050 
13051 	ctf_calc_rwin(so, tp);
13052 	/*
13053 	 * If the state is SYN_SENT: if seg contains an ACK, but not for our
13054 	 * SYN, drop the input. if seg contains a RST, then drop the
13055 	 * connection. if seg does not contain SYN, then drop it. Otherwise
13056 	 * this is an acceptable SYN segment initialize tp->rcv_nxt and
13057 	 * tp->irs if seg contains ack then advance tp->snd_una if seg
13058 	 * contains an ECE and ECN support is enabled, the stream is ECN
13059 	 * capable. if SYN has been acked change to ESTABLISHED else
13060 	 * SYN_RCVD state arrange for segment to be acked (eventually)
13061 	 * continue processing rest of data/controls.
13062 	 */
13063 	if ((thflags & TH_ACK) &&
13064 	    (SEQ_LEQ(th->th_ack, tp->iss) ||
13065 	    SEQ_GT(th->th_ack, tp->snd_max))) {
13066 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
13067 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
13068 		return (1);
13069 	}
13070 	if ((thflags & (TH_ACK | TH_RST)) == (TH_ACK | TH_RST)) {
13071 		TCP_PROBE5(connect__refused, NULL, tp,
13072 		    mtod(m, const char *), tp, th);
13073 		tp = tcp_drop(tp, ECONNREFUSED);
13074 		ctf_do_drop(m, tp);
13075 		return (1);
13076 	}
13077 	if (thflags & TH_RST) {
13078 		ctf_do_drop(m, tp);
13079 		return (1);
13080 	}
13081 	if (!(thflags & TH_SYN)) {
13082 		ctf_do_drop(m, tp);
13083 		return (1);
13084 	}
13085 	tp->irs = th->th_seq;
13086 	tcp_rcvseqinit(tp);
13087 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13088 	if (thflags & TH_ACK) {
13089 		int tfo_partial = 0;
13090 
13091 		KMOD_TCPSTAT_INC(tcps_connects);
13092 		soisconnected(so);
13093 #ifdef MAC
13094 		mac_socketpeer_set_from_mbuf(m, so);
13095 #endif
13096 		/* Do window scaling on this connection? */
13097 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
13098 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
13099 			tp->rcv_scale = tp->request_r_scale;
13100 		}
13101 		tp->rcv_adv += min(tp->rcv_wnd,
13102 		    TCP_MAXWIN << tp->rcv_scale);
13103 		/*
13104 		 * If not all the data that was sent in the TFO SYN
13105 		 * has been acked, resend the remainder right away.
13106 		 */
13107 		if (IS_FASTOPEN(tp->t_flags) &&
13108 		    (tp->snd_una != tp->snd_max)) {
13109 			tp->snd_nxt = th->th_ack;
13110 			tfo_partial = 1;
13111 		}
13112 		/*
13113 		 * If there's data, delay ACK; if there's also a FIN ACKNOW
13114 		 * will be turned on later.
13115 		 */
13116 		if (DELAY_ACK(tp, tlen) && tlen != 0 && !tfo_partial) {
13117 			rack_timer_cancel(tp, rack,
13118 					  rack->r_ctl.rc_rcvtime, __LINE__);
13119 			tp->t_flags |= TF_DELACK;
13120 		} else {
13121 			rack->r_wanted_output = 1;
13122 			tp->t_flags |= TF_ACKNOW;
13123 		}
13124 
13125 		tcp_ecn_input_syn_sent(tp, thflags, iptos);
13126 
13127 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
13128 			/*
13129 			 * We advance snd_una for the
13130 			 * fast open case. If th_ack is
13131 			 * acknowledging data beyond
13132 			 * snd_una we can't just call
13133 			 * ack-processing since the
13134 			 * data stream in our send-map
13135 			 * will start at snd_una + 1 (one
13136 			 * beyond the SYN). If its just
13137 			 * equal we don't need to do that
13138 			 * and there is no send_map.
13139 			 */
13140 			tp->snd_una++;
13141 		}
13142 		/*
13143 		 * Received <SYN,ACK> in SYN_SENT[*] state. Transitions:
13144 		 * SYN_SENT  --> ESTABLISHED SYN_SENT* --> FIN_WAIT_1
13145 		 */
13146 		tp->t_starttime = ticks;
13147 		if (tp->t_flags & TF_NEEDFIN) {
13148 			tcp_state_change(tp, TCPS_FIN_WAIT_1);
13149 			tp->t_flags &= ~TF_NEEDFIN;
13150 			thflags &= ~TH_SYN;
13151 		} else {
13152 			tcp_state_change(tp, TCPS_ESTABLISHED);
13153 			TCP_PROBE5(connect__established, NULL, tp,
13154 			    mtod(m, const char *), tp, th);
13155 			rack_cc_conn_init(tp);
13156 		}
13157 	} else {
13158 		/*
13159 		 * Received initial SYN in SYN-SENT[*] state => simultaneous
13160 		 * open.  If segment contains CC option and there is a
13161 		 * cached CC, apply TAO test. If it succeeds, connection is *
13162 		 * half-synchronized. Otherwise, do 3-way handshake:
13163 		 * SYN-SENT -> SYN-RECEIVED SYN-SENT* -> SYN-RECEIVED* If
13164 		 * there was no CC option, clear cached CC value.
13165 		 */
13166 		tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN | TF_SONOTCONN);
13167 		tcp_state_change(tp, TCPS_SYN_RECEIVED);
13168 	}
13169 	/*
13170 	 * Advance th->th_seq to correspond to first data byte. If data,
13171 	 * trim to stay within window, dropping FIN if necessary.
13172 	 */
13173 	th->th_seq++;
13174 	if (tlen > tp->rcv_wnd) {
13175 		todrop = tlen - tp->rcv_wnd;
13176 		m_adj(m, -todrop);
13177 		tlen = tp->rcv_wnd;
13178 		thflags &= ~TH_FIN;
13179 		KMOD_TCPSTAT_INC(tcps_rcvpackafterwin);
13180 		KMOD_TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop);
13181 	}
13182 	tp->snd_wl1 = th->th_seq - 1;
13183 	tp->rcv_up = th->th_seq;
13184 	/*
13185 	 * Client side of transaction: already sent SYN and data. If the
13186 	 * remote host used T/TCP to validate the SYN, our data will be
13187 	 * ACK'd; if so, enter normal data segment processing in the middle
13188 	 * of step 5, ack processing. Otherwise, goto step 6.
13189 	 */
13190 	if (thflags & TH_ACK) {
13191 		/* For syn-sent we need to possibly update the rtt */
13192 		if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
13193 			uint32_t t, mcts;
13194 
13195 			mcts = tcp_ts_getticks();
13196 			t = (mcts - to->to_tsecr) * HPTS_USEC_IN_MSEC;
13197 			if (!tp->t_rttlow || tp->t_rttlow > t)
13198 				tp->t_rttlow = t;
13199 			rack_log_rtt_sample_calc(rack, t, (to->to_tsecr * 1000), (mcts * 1000), 4);
13200 			tcp_rack_xmit_timer(rack, t + 1, 1, t, 0, NULL, 2);
13201 			tcp_rack_xmit_timer_commit(rack, tp);
13202 		}
13203 		if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val))
13204 			return (ret_val);
13205 		/* We may have changed to FIN_WAIT_1 above */
13206 		if (tp->t_state == TCPS_FIN_WAIT_1) {
13207 			/*
13208 			 * In FIN_WAIT_1 STATE in addition to the processing
13209 			 * for the ESTABLISHED state if our FIN is now
13210 			 * acknowledged then enter FIN_WAIT_2.
13211 			 */
13212 			if (ourfinisacked) {
13213 				/*
13214 				 * If we can't receive any more data, then
13215 				 * closing user can proceed. Starting the
13216 				 * timer is contrary to the specification,
13217 				 * but if we don't get a FIN we'll hang
13218 				 * forever.
13219 				 *
13220 				 * XXXjl: we should release the tp also, and
13221 				 * use a compressed state.
13222 				 */
13223 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13224 					soisdisconnected(so);
13225 					tcp_timer_activate(tp, TT_2MSL,
13226 					    (tcp_fast_finwait2_recycle ?
13227 					    tcp_finwait2_timeout :
13228 					    TP_MAXIDLE(tp)));
13229 				}
13230 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
13231 			}
13232 		}
13233 	}
13234 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13235 	   tiwin, thflags, nxt_pkt));
13236 }
13237 
13238 /*
13239  * Return value of 1, the TCB is unlocked and most
13240  * likely gone, return value of 0, the TCP is still
13241  * locked.
13242  */
13243 static int
13244 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
13245     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13246     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13247 {
13248 	struct tcp_rack *rack;
13249 	int32_t ret_val = 0;
13250 	int32_t ourfinisacked = 0;
13251 
13252 	ctf_calc_rwin(so, tp);
13253 	if ((thflags & TH_ACK) &&
13254 	    (SEQ_LEQ(th->th_ack, tp->snd_una) ||
13255 	    SEQ_GT(th->th_ack, tp->snd_max))) {
13256 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
13257 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
13258 		return (1);
13259 	}
13260 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13261 	if (IS_FASTOPEN(tp->t_flags)) {
13262 		/*
13263 		 * When a TFO connection is in SYN_RECEIVED, the
13264 		 * only valid packets are the initial SYN, a
13265 		 * retransmit/copy of the initial SYN (possibly with
13266 		 * a subset of the original data), a valid ACK, a
13267 		 * FIN, or a RST.
13268 		 */
13269 		if ((thflags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
13270 			tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
13271 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
13272 			return (1);
13273 		} else if (thflags & TH_SYN) {
13274 			/* non-initial SYN is ignored */
13275 			if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT) ||
13276 			    (rack->r_ctl.rc_hpts_flags & PACE_TMR_TLP) ||
13277 			    (rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK)) {
13278 				ctf_do_drop(m, NULL);
13279 				return (0);
13280 			}
13281 		} else if (!(thflags & (TH_ACK | TH_FIN | TH_RST))) {
13282 			ctf_do_drop(m, NULL);
13283 			return (0);
13284 		}
13285 	}
13286 
13287 	if ((thflags & TH_RST) ||
13288 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13289 		return (__ctf_process_rst(m, th, so, tp,
13290 					  &rack->r_ctl.challenge_ack_ts,
13291 					  &rack->r_ctl.challenge_ack_cnt));
13292 	/*
13293 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
13294 	 * it's less than ts_recent, drop it.
13295 	 */
13296 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
13297 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
13298 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13299 			return (ret_val);
13300 	}
13301 	/*
13302 	 * In the SYN-RECEIVED state, validate that the packet belongs to
13303 	 * this connection before trimming the data to fit the receive
13304 	 * window.  Check the sequence number versus IRS since we know the
13305 	 * sequence numbers haven't wrapped.  This is a partial fix for the
13306 	 * "LAND" DoS attack.
13307 	 */
13308 	if (SEQ_LT(th->th_seq, tp->irs)) {
13309 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
13310 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
13311 		return (1);
13312 	}
13313 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
13314 			      &rack->r_ctl.challenge_ack_ts,
13315 			      &rack->r_ctl.challenge_ack_cnt)) {
13316 		return (ret_val);
13317 	}
13318 	/*
13319 	 * If last ACK falls within this segment's sequence numbers, record
13320 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
13321 	 * from the latest proposal of the tcplw@cray.com list (Braden
13322 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
13323 	 * with our earlier PAWS tests, so this check should be solely
13324 	 * predicated on the sequence space of this segment. 3) That we
13325 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
13326 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
13327 	 * SEG.Len, This modified check allows us to overcome RFC1323's
13328 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
13329 	 * p.869. In such cases, we can still calculate the RTT correctly
13330 	 * when RCV.NXT == Last.ACK.Sent.
13331 	 */
13332 	if ((to->to_flags & TOF_TS) != 0 &&
13333 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
13334 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
13335 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
13336 		tp->ts_recent_age = tcp_ts_getticks();
13337 		tp->ts_recent = to->to_tsval;
13338 	}
13339 	tp->snd_wnd = tiwin;
13340 	rack_validate_fo_sendwin_up(tp, rack);
13341 	/*
13342 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
13343 	 * is on (half-synchronized state), then queue data for later
13344 	 * processing; else drop segment and return.
13345 	 */
13346 	if ((thflags & TH_ACK) == 0) {
13347 		if (IS_FASTOPEN(tp->t_flags)) {
13348 			rack_cc_conn_init(tp);
13349 		}
13350 		return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13351 		    tiwin, thflags, nxt_pkt));
13352 	}
13353 	KMOD_TCPSTAT_INC(tcps_connects);
13354 	if (tp->t_flags & TF_SONOTCONN) {
13355 		tp->t_flags &= ~TF_SONOTCONN;
13356 		soisconnected(so);
13357 	}
13358 	/* Do window scaling? */
13359 	if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
13360 	    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
13361 		tp->rcv_scale = tp->request_r_scale;
13362 	}
13363 	/*
13364 	 * Make transitions: SYN-RECEIVED  -> ESTABLISHED SYN-RECEIVED* ->
13365 	 * FIN-WAIT-1
13366 	 */
13367 	tp->t_starttime = ticks;
13368 	if (IS_FASTOPEN(tp->t_flags) && tp->t_tfo_pending) {
13369 		tcp_fastopen_decrement_counter(tp->t_tfo_pending);
13370 		tp->t_tfo_pending = NULL;
13371 	}
13372 	if (tp->t_flags & TF_NEEDFIN) {
13373 		tcp_state_change(tp, TCPS_FIN_WAIT_1);
13374 		tp->t_flags &= ~TF_NEEDFIN;
13375 	} else {
13376 		tcp_state_change(tp, TCPS_ESTABLISHED);
13377 		TCP_PROBE5(accept__established, NULL, tp,
13378 		    mtod(m, const char *), tp, th);
13379 		/*
13380 		 * TFO connections call cc_conn_init() during SYN
13381 		 * processing.  Calling it again here for such connections
13382 		 * is not harmless as it would undo the snd_cwnd reduction
13383 		 * that occurs when a TFO SYN|ACK is retransmitted.
13384 		 */
13385 		if (!IS_FASTOPEN(tp->t_flags))
13386 			rack_cc_conn_init(tp);
13387 	}
13388 	/*
13389 	 * Account for the ACK of our SYN prior to
13390 	 * regular ACK processing below, except for
13391 	 * simultaneous SYN, which is handled later.
13392 	 */
13393 	if (SEQ_GT(th->th_ack, tp->snd_una) && !(tp->t_flags & TF_NEEDSYN))
13394 		tp->snd_una++;
13395 	/*
13396 	 * If segment contains data or ACK, will call tcp_reass() later; if
13397 	 * not, do so now to pass queued data to user.
13398 	 */
13399 	if (tlen == 0 && (thflags & TH_FIN) == 0) {
13400 		(void) tcp_reass(tp, (struct tcphdr *)0, NULL, 0,
13401 		    (struct mbuf *)0);
13402 		if (tp->t_flags & TF_WAKESOR) {
13403 			tp->t_flags &= ~TF_WAKESOR;
13404 			/* NB: sorwakeup_locked() does an implicit unlock. */
13405 			sorwakeup_locked(so);
13406 		}
13407 	}
13408 	tp->snd_wl1 = th->th_seq - 1;
13409 	/* For syn-recv we need to possibly update the rtt */
13410 	if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
13411 		uint32_t t, mcts;
13412 
13413 		mcts = tcp_ts_getticks();
13414 		t = (mcts - to->to_tsecr) * HPTS_USEC_IN_MSEC;
13415 		if (!tp->t_rttlow || tp->t_rttlow > t)
13416 			tp->t_rttlow = t;
13417 		rack_log_rtt_sample_calc(rack, t, (to->to_tsecr * 1000), (mcts * 1000), 5);
13418 		tcp_rack_xmit_timer(rack, t + 1, 1, t, 0, NULL, 2);
13419 		tcp_rack_xmit_timer_commit(rack, tp);
13420 	}
13421 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
13422 		return (ret_val);
13423 	}
13424 	if (tp->t_state == TCPS_FIN_WAIT_1) {
13425 		/* We could have went to FIN_WAIT_1 (or EST) above */
13426 		/*
13427 		 * In FIN_WAIT_1 STATE in addition to the processing for the
13428 		 * ESTABLISHED state if our FIN is now acknowledged then
13429 		 * enter FIN_WAIT_2.
13430 		 */
13431 		if (ourfinisacked) {
13432 			/*
13433 			 * If we can't receive any more data, then closing
13434 			 * user can proceed. Starting the timer is contrary
13435 			 * to the specification, but if we don't get a FIN
13436 			 * we'll hang forever.
13437 			 *
13438 			 * XXXjl: we should release the tp also, and use a
13439 			 * compressed state.
13440 			 */
13441 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13442 				soisdisconnected(so);
13443 				tcp_timer_activate(tp, TT_2MSL,
13444 				    (tcp_fast_finwait2_recycle ?
13445 				    tcp_finwait2_timeout :
13446 				    TP_MAXIDLE(tp)));
13447 			}
13448 			tcp_state_change(tp, TCPS_FIN_WAIT_2);
13449 		}
13450 	}
13451 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13452 	    tiwin, thflags, nxt_pkt));
13453 }
13454 
13455 /*
13456  * Return value of 1, the TCB is unlocked and most
13457  * likely gone, return value of 0, the TCP is still
13458  * locked.
13459  */
13460 static int
13461 rack_do_established(struct mbuf *m, struct tcphdr *th, struct socket *so,
13462     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13463     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13464 {
13465 	int32_t ret_val = 0;
13466 	struct tcp_rack *rack;
13467 
13468 	/*
13469 	 * Header prediction: check for the two common cases of a
13470 	 * uni-directional data xfer.  If the packet has no control flags,
13471 	 * is in-sequence, the window didn't change and we're not
13472 	 * retransmitting, it's a candidate.  If the length is zero and the
13473 	 * ack moved forward, we're the sender side of the xfer.  Just free
13474 	 * the data acked & wake any higher level process that was blocked
13475 	 * waiting for space.  If the length is non-zero and the ack didn't
13476 	 * move, we're the receiver side.  If we're getting packets in-order
13477 	 * (the reassembly queue is empty), add the data toc The socket
13478 	 * buffer and note that we need a delayed ack. Make sure that the
13479 	 * hidden state-flags are also off. Since we check for
13480 	 * TCPS_ESTABLISHED first, it can only be TH_NEEDSYN.
13481 	 */
13482 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13483 	if (__predict_true(((to->to_flags & TOF_SACK) == 0)) &&
13484 	    __predict_true((thflags & (TH_SYN | TH_FIN | TH_RST | TH_ACK)) == TH_ACK) &&
13485 	    __predict_true(SEGQ_EMPTY(tp)) &&
13486 	    __predict_true(th->th_seq == tp->rcv_nxt)) {
13487 		if (tlen == 0) {
13488 			if (rack_fastack(m, th, so, tp, to, drop_hdrlen, tlen,
13489 			    tiwin, nxt_pkt, rack->r_ctl.rc_rcvtime)) {
13490 				return (0);
13491 			}
13492 		} else {
13493 			if (rack_do_fastnewdata(m, th, so, tp, to, drop_hdrlen, tlen,
13494 			    tiwin, nxt_pkt, iptos)) {
13495 				return (0);
13496 			}
13497 		}
13498 	}
13499 	ctf_calc_rwin(so, tp);
13500 
13501 	if ((thflags & TH_RST) ||
13502 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13503 		return (__ctf_process_rst(m, th, so, tp,
13504 					  &rack->r_ctl.challenge_ack_ts,
13505 					  &rack->r_ctl.challenge_ack_cnt));
13506 
13507 	/*
13508 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
13509 	 * synchronized state.
13510 	 */
13511 	if (thflags & TH_SYN) {
13512 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
13513 		return (ret_val);
13514 	}
13515 	/*
13516 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
13517 	 * it's less than ts_recent, drop it.
13518 	 */
13519 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
13520 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
13521 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13522 			return (ret_val);
13523 	}
13524 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
13525 			      &rack->r_ctl.challenge_ack_ts,
13526 			      &rack->r_ctl.challenge_ack_cnt)) {
13527 		return (ret_val);
13528 	}
13529 	/*
13530 	 * If last ACK falls within this segment's sequence numbers, record
13531 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
13532 	 * from the latest proposal of the tcplw@cray.com list (Braden
13533 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
13534 	 * with our earlier PAWS tests, so this check should be solely
13535 	 * predicated on the sequence space of this segment. 3) That we
13536 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
13537 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
13538 	 * SEG.Len, This modified check allows us to overcome RFC1323's
13539 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
13540 	 * p.869. In such cases, we can still calculate the RTT correctly
13541 	 * when RCV.NXT == Last.ACK.Sent.
13542 	 */
13543 	if ((to->to_flags & TOF_TS) != 0 &&
13544 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
13545 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
13546 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
13547 		tp->ts_recent_age = tcp_ts_getticks();
13548 		tp->ts_recent = to->to_tsval;
13549 	}
13550 	/*
13551 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
13552 	 * is on (half-synchronized state), then queue data for later
13553 	 * processing; else drop segment and return.
13554 	 */
13555 	if ((thflags & TH_ACK) == 0) {
13556 		if (tp->t_flags & TF_NEEDSYN) {
13557 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13558 			    tiwin, thflags, nxt_pkt));
13559 
13560 		} else if (tp->t_flags & TF_ACKNOW) {
13561 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
13562 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
13563 			return (ret_val);
13564 		} else {
13565 			ctf_do_drop(m, NULL);
13566 			return (0);
13567 		}
13568 	}
13569 	/*
13570 	 * Ack processing.
13571 	 */
13572 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
13573 		return (ret_val);
13574 	}
13575 	if (sbavail(&so->so_snd)) {
13576 		if (ctf_progress_timeout_check(tp, true)) {
13577 			rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
13578 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
13579 			return (1);
13580 		}
13581 	}
13582 	/* State changes only happen in rack_process_data() */
13583 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13584 	    tiwin, thflags, nxt_pkt));
13585 }
13586 
13587 /*
13588  * Return value of 1, the TCB is unlocked and most
13589  * likely gone, return value of 0, the TCP is still
13590  * locked.
13591  */
13592 static int
13593 rack_do_close_wait(struct mbuf *m, struct tcphdr *th, struct socket *so,
13594     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13595     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13596 {
13597 	int32_t ret_val = 0;
13598 	struct tcp_rack *rack;
13599 
13600 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13601 	ctf_calc_rwin(so, tp);
13602 	if ((thflags & TH_RST) ||
13603 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13604 		return (__ctf_process_rst(m, th, so, tp,
13605 					  &rack->r_ctl.challenge_ack_ts,
13606 					  &rack->r_ctl.challenge_ack_cnt));
13607 	/*
13608 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
13609 	 * synchronized state.
13610 	 */
13611 	if (thflags & TH_SYN) {
13612 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
13613 		return (ret_val);
13614 	}
13615 	/*
13616 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
13617 	 * it's less than ts_recent, drop it.
13618 	 */
13619 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
13620 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
13621 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13622 			return (ret_val);
13623 	}
13624 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
13625 			      &rack->r_ctl.challenge_ack_ts,
13626 			      &rack->r_ctl.challenge_ack_cnt)) {
13627 		return (ret_val);
13628 	}
13629 	/*
13630 	 * If last ACK falls within this segment's sequence numbers, record
13631 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
13632 	 * from the latest proposal of the tcplw@cray.com list (Braden
13633 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
13634 	 * with our earlier PAWS tests, so this check should be solely
13635 	 * predicated on the sequence space of this segment. 3) That we
13636 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
13637 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
13638 	 * SEG.Len, This modified check allows us to overcome RFC1323's
13639 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
13640 	 * p.869. In such cases, we can still calculate the RTT correctly
13641 	 * when RCV.NXT == Last.ACK.Sent.
13642 	 */
13643 	if ((to->to_flags & TOF_TS) != 0 &&
13644 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
13645 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
13646 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
13647 		tp->ts_recent_age = tcp_ts_getticks();
13648 		tp->ts_recent = to->to_tsval;
13649 	}
13650 	/*
13651 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
13652 	 * is on (half-synchronized state), then queue data for later
13653 	 * processing; else drop segment and return.
13654 	 */
13655 	if ((thflags & TH_ACK) == 0) {
13656 		if (tp->t_flags & TF_NEEDSYN) {
13657 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13658 			    tiwin, thflags, nxt_pkt));
13659 
13660 		} else if (tp->t_flags & TF_ACKNOW) {
13661 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
13662 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
13663 			return (ret_val);
13664 		} else {
13665 			ctf_do_drop(m, NULL);
13666 			return (0);
13667 		}
13668 	}
13669 	/*
13670 	 * Ack processing.
13671 	 */
13672 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
13673 		return (ret_val);
13674 	}
13675 	if (sbavail(&so->so_snd)) {
13676 		if (ctf_progress_timeout_check(tp, true)) {
13677 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
13678 						tp, tick, PROGRESS_DROP, __LINE__);
13679 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
13680 			return (1);
13681 		}
13682 	}
13683 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13684 	    tiwin, thflags, nxt_pkt));
13685 }
13686 
13687 static int
13688 rack_check_data_after_close(struct mbuf *m,
13689     struct tcpcb *tp, int32_t *tlen, struct tcphdr *th, struct socket *so)
13690 {
13691 	struct tcp_rack *rack;
13692 
13693 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13694 	if (rack->rc_allow_data_af_clo == 0) {
13695 	close_now:
13696 		tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
13697 		/* tcp_close will kill the inp pre-log the Reset */
13698 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
13699 		tp = tcp_close(tp);
13700 		KMOD_TCPSTAT_INC(tcps_rcvafterclose);
13701 		ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, (*tlen));
13702 		return (1);
13703 	}
13704 	if (sbavail(&so->so_snd) == 0)
13705 		goto close_now;
13706 	/* Ok we allow data that is ignored and a followup reset */
13707 	tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
13708 	tp->rcv_nxt = th->th_seq + *tlen;
13709 	tp->t_flags2 |= TF2_DROP_AF_DATA;
13710 	rack->r_wanted_output = 1;
13711 	*tlen = 0;
13712 	return (0);
13713 }
13714 
13715 /*
13716  * Return value of 1, the TCB is unlocked and most
13717  * likely gone, return value of 0, the TCP is still
13718  * locked.
13719  */
13720 static int
13721 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, struct socket *so,
13722     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13723     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13724 {
13725 	int32_t ret_val = 0;
13726 	int32_t ourfinisacked = 0;
13727 	struct tcp_rack *rack;
13728 
13729 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13730 	ctf_calc_rwin(so, tp);
13731 
13732 	if ((thflags & TH_RST) ||
13733 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13734 		return (__ctf_process_rst(m, th, so, tp,
13735 					  &rack->r_ctl.challenge_ack_ts,
13736 					  &rack->r_ctl.challenge_ack_cnt));
13737 	/*
13738 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
13739 	 * synchronized state.
13740 	 */
13741 	if (thflags & TH_SYN) {
13742 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
13743 		return (ret_val);
13744 	}
13745 	/*
13746 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
13747 	 * it's less than ts_recent, drop it.
13748 	 */
13749 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
13750 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
13751 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13752 			return (ret_val);
13753 	}
13754 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
13755 			      &rack->r_ctl.challenge_ack_ts,
13756 			      &rack->r_ctl.challenge_ack_cnt)) {
13757 		return (ret_val);
13758 	}
13759 	/*
13760 	 * If new data are received on a connection after the user processes
13761 	 * are gone, then RST the other end.
13762 	 */
13763 	if ((tp->t_flags & TF_CLOSED) && tlen &&
13764 	    rack_check_data_after_close(m, tp, &tlen, th, so))
13765 		return (1);
13766 	/*
13767 	 * If last ACK falls within this segment's sequence numbers, record
13768 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
13769 	 * from the latest proposal of the tcplw@cray.com list (Braden
13770 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
13771 	 * with our earlier PAWS tests, so this check should be solely
13772 	 * predicated on the sequence space of this segment. 3) That we
13773 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
13774 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
13775 	 * SEG.Len, This modified check allows us to overcome RFC1323's
13776 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
13777 	 * p.869. In such cases, we can still calculate the RTT correctly
13778 	 * when RCV.NXT == Last.ACK.Sent.
13779 	 */
13780 	if ((to->to_flags & TOF_TS) != 0 &&
13781 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
13782 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
13783 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
13784 		tp->ts_recent_age = tcp_ts_getticks();
13785 		tp->ts_recent = to->to_tsval;
13786 	}
13787 	/*
13788 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
13789 	 * is on (half-synchronized state), then queue data for later
13790 	 * processing; else drop segment and return.
13791 	 */
13792 	if ((thflags & TH_ACK) == 0) {
13793 		if (tp->t_flags & TF_NEEDSYN) {
13794 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13795 			    tiwin, thflags, nxt_pkt));
13796 		} else if (tp->t_flags & TF_ACKNOW) {
13797 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
13798 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
13799 			return (ret_val);
13800 		} else {
13801 			ctf_do_drop(m, NULL);
13802 			return (0);
13803 		}
13804 	}
13805 	/*
13806 	 * Ack processing.
13807 	 */
13808 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
13809 		return (ret_val);
13810 	}
13811 	if (ourfinisacked) {
13812 		/*
13813 		 * If we can't receive any more data, then closing user can
13814 		 * proceed. Starting the timer is contrary to the
13815 		 * specification, but if we don't get a FIN we'll hang
13816 		 * forever.
13817 		 *
13818 		 * XXXjl: we should release the tp also, and use a
13819 		 * compressed state.
13820 		 */
13821 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13822 			soisdisconnected(so);
13823 			tcp_timer_activate(tp, TT_2MSL,
13824 			    (tcp_fast_finwait2_recycle ?
13825 			    tcp_finwait2_timeout :
13826 			    TP_MAXIDLE(tp)));
13827 		}
13828 		tcp_state_change(tp, TCPS_FIN_WAIT_2);
13829 	}
13830 	if (sbavail(&so->so_snd)) {
13831 		if (ctf_progress_timeout_check(tp, true)) {
13832 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
13833 						tp, tick, PROGRESS_DROP, __LINE__);
13834 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
13835 			return (1);
13836 		}
13837 	}
13838 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13839 	    tiwin, thflags, nxt_pkt));
13840 }
13841 
13842 /*
13843  * Return value of 1, the TCB is unlocked and most
13844  * likely gone, return value of 0, the TCP is still
13845  * locked.
13846  */
13847 static int
13848 rack_do_closing(struct mbuf *m, struct tcphdr *th, struct socket *so,
13849     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13850     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13851 {
13852 	int32_t ret_val = 0;
13853 	int32_t ourfinisacked = 0;
13854 	struct tcp_rack *rack;
13855 
13856 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13857 	ctf_calc_rwin(so, tp);
13858 
13859 	if ((thflags & TH_RST) ||
13860 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13861 		return (__ctf_process_rst(m, th, so, tp,
13862 					  &rack->r_ctl.challenge_ack_ts,
13863 					  &rack->r_ctl.challenge_ack_cnt));
13864 	/*
13865 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
13866 	 * synchronized state.
13867 	 */
13868 	if (thflags & TH_SYN) {
13869 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
13870 		return (ret_val);
13871 	}
13872 	/*
13873 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
13874 	 * it's less than ts_recent, drop it.
13875 	 */
13876 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
13877 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
13878 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13879 			return (ret_val);
13880 	}
13881 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
13882 			      &rack->r_ctl.challenge_ack_ts,
13883 			      &rack->r_ctl.challenge_ack_cnt)) {
13884 		return (ret_val);
13885 	}
13886 	/*
13887 	 * If new data are received on a connection after the user processes
13888 	 * are gone, then RST the other end.
13889 	 */
13890 	if ((tp->t_flags & TF_CLOSED) && tlen &&
13891 	    rack_check_data_after_close(m, tp, &tlen, th, so))
13892 		return (1);
13893 	/*
13894 	 * If last ACK falls within this segment's sequence numbers, record
13895 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
13896 	 * from the latest proposal of the tcplw@cray.com list (Braden
13897 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
13898 	 * with our earlier PAWS tests, so this check should be solely
13899 	 * predicated on the sequence space of this segment. 3) That we
13900 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
13901 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
13902 	 * SEG.Len, This modified check allows us to overcome RFC1323's
13903 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
13904 	 * p.869. In such cases, we can still calculate the RTT correctly
13905 	 * when RCV.NXT == Last.ACK.Sent.
13906 	 */
13907 	if ((to->to_flags & TOF_TS) != 0 &&
13908 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
13909 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
13910 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
13911 		tp->ts_recent_age = tcp_ts_getticks();
13912 		tp->ts_recent = to->to_tsval;
13913 	}
13914 	/*
13915 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
13916 	 * is on (half-synchronized state), then queue data for later
13917 	 * processing; else drop segment and return.
13918 	 */
13919 	if ((thflags & TH_ACK) == 0) {
13920 		if (tp->t_flags & TF_NEEDSYN) {
13921 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13922 			    tiwin, thflags, nxt_pkt));
13923 		} else if (tp->t_flags & TF_ACKNOW) {
13924 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
13925 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
13926 			return (ret_val);
13927 		} else {
13928 			ctf_do_drop(m, NULL);
13929 			return (0);
13930 		}
13931 	}
13932 	/*
13933 	 * Ack processing.
13934 	 */
13935 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
13936 		return (ret_val);
13937 	}
13938 	if (ourfinisacked) {
13939 		tcp_twstart(tp);
13940 		m_freem(m);
13941 		return (1);
13942 	}
13943 	if (sbavail(&so->so_snd)) {
13944 		if (ctf_progress_timeout_check(tp, true)) {
13945 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
13946 						tp, tick, PROGRESS_DROP, __LINE__);
13947 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
13948 			return (1);
13949 		}
13950 	}
13951 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13952 	    tiwin, thflags, nxt_pkt));
13953 }
13954 
13955 /*
13956  * Return value of 1, the TCB is unlocked and most
13957  * likely gone, return value of 0, the TCP is still
13958  * locked.
13959  */
13960 static int
13961 rack_do_lastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
13962     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13963     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13964 {
13965 	int32_t ret_val = 0;
13966 	int32_t ourfinisacked = 0;
13967 	struct tcp_rack *rack;
13968 
13969 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13970 	ctf_calc_rwin(so, tp);
13971 
13972 	if ((thflags & TH_RST) ||
13973 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13974 		return (__ctf_process_rst(m, th, so, tp,
13975 					  &rack->r_ctl.challenge_ack_ts,
13976 					  &rack->r_ctl.challenge_ack_cnt));
13977 	/*
13978 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
13979 	 * synchronized state.
13980 	 */
13981 	if (thflags & TH_SYN) {
13982 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
13983 		return (ret_val);
13984 	}
13985 	/*
13986 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
13987 	 * it's less than ts_recent, drop it.
13988 	 */
13989 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
13990 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
13991 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13992 			return (ret_val);
13993 	}
13994 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
13995 			      &rack->r_ctl.challenge_ack_ts,
13996 			      &rack->r_ctl.challenge_ack_cnt)) {
13997 		return (ret_val);
13998 	}
13999 	/*
14000 	 * If new data are received on a connection after the user processes
14001 	 * are gone, then RST the other end.
14002 	 */
14003 	if ((tp->t_flags & TF_CLOSED) && tlen &&
14004 	    rack_check_data_after_close(m, tp, &tlen, th, so))
14005 		return (1);
14006 	/*
14007 	 * If last ACK falls within this segment's sequence numbers, record
14008 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
14009 	 * from the latest proposal of the tcplw@cray.com list (Braden
14010 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
14011 	 * with our earlier PAWS tests, so this check should be solely
14012 	 * predicated on the sequence space of this segment. 3) That we
14013 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
14014 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
14015 	 * SEG.Len, This modified check allows us to overcome RFC1323's
14016 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
14017 	 * p.869. In such cases, we can still calculate the RTT correctly
14018 	 * when RCV.NXT == Last.ACK.Sent.
14019 	 */
14020 	if ((to->to_flags & TOF_TS) != 0 &&
14021 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
14022 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
14023 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
14024 		tp->ts_recent_age = tcp_ts_getticks();
14025 		tp->ts_recent = to->to_tsval;
14026 	}
14027 	/*
14028 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
14029 	 * is on (half-synchronized state), then queue data for later
14030 	 * processing; else drop segment and return.
14031 	 */
14032 	if ((thflags & TH_ACK) == 0) {
14033 		if (tp->t_flags & TF_NEEDSYN) {
14034 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
14035 			    tiwin, thflags, nxt_pkt));
14036 		} else if (tp->t_flags & TF_ACKNOW) {
14037 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
14038 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
14039 			return (ret_val);
14040 		} else {
14041 			ctf_do_drop(m, NULL);
14042 			return (0);
14043 		}
14044 	}
14045 	/*
14046 	 * case TCPS_LAST_ACK: Ack processing.
14047 	 */
14048 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
14049 		return (ret_val);
14050 	}
14051 	if (ourfinisacked) {
14052 		tp = tcp_close(tp);
14053 		ctf_do_drop(m, tp);
14054 		return (1);
14055 	}
14056 	if (sbavail(&so->so_snd)) {
14057 		if (ctf_progress_timeout_check(tp, true)) {
14058 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
14059 						tp, tick, PROGRESS_DROP, __LINE__);
14060 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
14061 			return (1);
14062 		}
14063 	}
14064 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
14065 	    tiwin, thflags, nxt_pkt));
14066 }
14067 
14068 /*
14069  * Return value of 1, the TCB is unlocked and most
14070  * likely gone, return value of 0, the TCP is still
14071  * locked.
14072  */
14073 static int
14074 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, struct socket *so,
14075     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
14076     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
14077 {
14078 	int32_t ret_val = 0;
14079 	int32_t ourfinisacked = 0;
14080 	struct tcp_rack *rack;
14081 
14082 	rack = (struct tcp_rack *)tp->t_fb_ptr;
14083 	ctf_calc_rwin(so, tp);
14084 
14085 	/* Reset receive buffer auto scaling when not in bulk receive mode. */
14086 	if ((thflags & TH_RST) ||
14087 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
14088 		return (__ctf_process_rst(m, th, so, tp,
14089 					  &rack->r_ctl.challenge_ack_ts,
14090 					  &rack->r_ctl.challenge_ack_cnt));
14091 	/*
14092 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
14093 	 * synchronized state.
14094 	 */
14095 	if (thflags & TH_SYN) {
14096 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
14097 		return (ret_val);
14098 	}
14099 	/*
14100 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
14101 	 * it's less than ts_recent, drop it.
14102 	 */
14103 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
14104 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
14105 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
14106 			return (ret_val);
14107 	}
14108 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
14109 			      &rack->r_ctl.challenge_ack_ts,
14110 			      &rack->r_ctl.challenge_ack_cnt)) {
14111 		return (ret_val);
14112 	}
14113 	/*
14114 	 * If new data are received on a connection after the user processes
14115 	 * are gone, then RST the other end.
14116 	 */
14117 	if ((tp->t_flags & TF_CLOSED) && tlen &&
14118 	    rack_check_data_after_close(m, tp, &tlen, th, so))
14119 		return (1);
14120 	/*
14121 	 * If last ACK falls within this segment's sequence numbers, record
14122 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
14123 	 * from the latest proposal of the tcplw@cray.com list (Braden
14124 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
14125 	 * with our earlier PAWS tests, so this check should be solely
14126 	 * predicated on the sequence space of this segment. 3) That we
14127 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
14128 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
14129 	 * SEG.Len, This modified check allows us to overcome RFC1323's
14130 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
14131 	 * p.869. In such cases, we can still calculate the RTT correctly
14132 	 * when RCV.NXT == Last.ACK.Sent.
14133 	 */
14134 	if ((to->to_flags & TOF_TS) != 0 &&
14135 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
14136 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
14137 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
14138 		tp->ts_recent_age = tcp_ts_getticks();
14139 		tp->ts_recent = to->to_tsval;
14140 	}
14141 	/*
14142 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
14143 	 * is on (half-synchronized state), then queue data for later
14144 	 * processing; else drop segment and return.
14145 	 */
14146 	if ((thflags & TH_ACK) == 0) {
14147 		if (tp->t_flags & TF_NEEDSYN) {
14148 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
14149 			    tiwin, thflags, nxt_pkt));
14150 		} else if (tp->t_flags & TF_ACKNOW) {
14151 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
14152 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
14153 			return (ret_val);
14154 		} else {
14155 			ctf_do_drop(m, NULL);
14156 			return (0);
14157 		}
14158 	}
14159 	/*
14160 	 * Ack processing.
14161 	 */
14162 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
14163 		return (ret_val);
14164 	}
14165 	if (sbavail(&so->so_snd)) {
14166 		if (ctf_progress_timeout_check(tp, true)) {
14167 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
14168 						tp, tick, PROGRESS_DROP, __LINE__);
14169 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
14170 			return (1);
14171 		}
14172 	}
14173 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
14174 	    tiwin, thflags, nxt_pkt));
14175 }
14176 
14177 static void inline
14178 rack_clear_rate_sample(struct tcp_rack *rack)
14179 {
14180 	rack->r_ctl.rack_rs.rs_flags = RACK_RTT_EMPTY;
14181 	rack->r_ctl.rack_rs.rs_rtt_cnt = 0;
14182 	rack->r_ctl.rack_rs.rs_rtt_tot = 0;
14183 }
14184 
14185 static void
14186 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line, uint64_t *fill_override)
14187 {
14188 	uint64_t bw_est, rate_wanted;
14189 	int chged = 0;
14190 	uint32_t user_max, orig_min, orig_max;
14191 
14192 #ifdef TCP_REQUEST_TRK
14193 	if (rack->rc_hybrid_mode &&
14194 	    (rack->r_ctl.rc_pace_max_segs != 0) &&
14195 	    (rack_hybrid_allow_set_maxseg == 1) &&
14196 	    (rack->r_ctl.rc_last_sft != NULL)) {
14197 		rack->r_ctl.rc_last_sft->hybrid_flags &= ~TCP_HYBRID_PACING_SETMSS;
14198 		return;
14199 	}
14200 #endif
14201 	orig_min = rack->r_ctl.rc_pace_min_segs;
14202 	orig_max = rack->r_ctl.rc_pace_max_segs;
14203 	user_max = ctf_fixed_maxseg(tp) * rack->rc_user_set_max_segs;
14204 	if (ctf_fixed_maxseg(tp) != rack->r_ctl.rc_pace_min_segs)
14205 		chged = 1;
14206 	rack->r_ctl.rc_pace_min_segs = ctf_fixed_maxseg(tp);
14207 	if (rack->use_fixed_rate || rack->rc_force_max_seg) {
14208 		if (user_max != rack->r_ctl.rc_pace_max_segs)
14209 			chged = 1;
14210 	}
14211 	if (rack->rc_force_max_seg) {
14212 		rack->r_ctl.rc_pace_max_segs = user_max;
14213 	} else if (rack->use_fixed_rate) {
14214 		bw_est = rack_get_bw(rack);
14215 		if ((rack->r_ctl.crte == NULL) ||
14216 		    (bw_est != rack->r_ctl.crte->rate)) {
14217 			rack->r_ctl.rc_pace_max_segs = user_max;
14218 		} else {
14219 			/* We are pacing right at the hardware rate */
14220 			uint32_t segsiz, pace_one;
14221 
14222 			if (rack_pace_one_seg ||
14223 			    (rack->r_ctl.rc_user_set_min_segs == 1))
14224 				pace_one = 1;
14225 			else
14226 				pace_one = 0;
14227 			segsiz = min(ctf_fixed_maxseg(tp),
14228 				     rack->r_ctl.rc_pace_min_segs);
14229 			rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size_w_divisor(
14230 				tp, bw_est, segsiz, pace_one,
14231 				rack->r_ctl.crte, NULL, rack->r_ctl.pace_len_divisor);
14232 		}
14233 	} else if (rack->rc_always_pace) {
14234 		if (rack->r_ctl.gp_bw ||
14235 		    rack->r_ctl.init_rate) {
14236 			/* We have a rate of some sort set */
14237 			uint32_t  orig;
14238 
14239 			bw_est = rack_get_bw(rack);
14240 			orig = rack->r_ctl.rc_pace_max_segs;
14241 			if (fill_override)
14242 				rate_wanted = *fill_override;
14243 			else
14244 				rate_wanted = rack_get_output_bw(rack, bw_est, NULL, NULL);
14245 			if (rate_wanted) {
14246 				/* We have something */
14247 				rack->r_ctl.rc_pace_max_segs = rack_get_pacing_len(rack,
14248 										   rate_wanted,
14249 										   ctf_fixed_maxseg(rack->rc_tp));
14250 			} else
14251 				rack->r_ctl.rc_pace_max_segs = rack->r_ctl.rc_pace_min_segs;
14252 			if (orig != rack->r_ctl.rc_pace_max_segs)
14253 				chged = 1;
14254 		} else if ((rack->r_ctl.gp_bw == 0) &&
14255 			   (rack->r_ctl.rc_pace_max_segs == 0)) {
14256 			/*
14257 			 * If we have nothing limit us to bursting
14258 			 * out IW sized pieces.
14259 			 */
14260 			chged = 1;
14261 			rack->r_ctl.rc_pace_max_segs = rc_init_window(rack);
14262 		}
14263 	}
14264 	if (rack->r_ctl.rc_pace_max_segs > PACE_MAX_IP_BYTES) {
14265 		chged = 1;
14266 		rack->r_ctl.rc_pace_max_segs = PACE_MAX_IP_BYTES;
14267 	}
14268 	if (chged)
14269 		rack_log_type_pacing_sizes(tp, rack, orig_min, orig_max, line, 2);
14270 }
14271 
14272 
14273 static void
14274 rack_init_fsb_block(struct tcpcb *tp, struct tcp_rack *rack, int32_t flags)
14275 {
14276 #ifdef INET6
14277 	struct ip6_hdr *ip6 = NULL;
14278 #endif
14279 #ifdef INET
14280 	struct ip *ip = NULL;
14281 #endif
14282 	struct udphdr *udp = NULL;
14283 
14284 	/* Ok lets fill in the fast block, it can only be used with no IP options! */
14285 #ifdef INET6
14286 	if (rack->r_is_v6) {
14287 		rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
14288 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
14289 		if (tp->t_port) {
14290 			rack->r_ctl.fsb.tcp_ip_hdr_len += sizeof(struct udphdr);
14291 			udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
14292 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
14293 			udp->uh_dport = tp->t_port;
14294 			rack->r_ctl.fsb.udp = udp;
14295 			rack->r_ctl.fsb.th = (struct tcphdr *)(udp + 1);
14296 		} else
14297 		{
14298 			rack->r_ctl.fsb.th = (struct tcphdr *)(ip6 + 1);
14299 			rack->r_ctl.fsb.udp = NULL;
14300 		}
14301 		tcpip_fillheaders(rack->rc_inp,
14302 				  tp->t_port,
14303 				  ip6, rack->r_ctl.fsb.th);
14304 		rack->r_ctl.fsb.hoplimit = in6_selecthlim(rack->rc_inp, NULL);
14305 	} else
14306 #endif				/* INET6 */
14307 #ifdef INET
14308 	{
14309 		rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct tcpiphdr);
14310 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
14311 		if (tp->t_port) {
14312 			rack->r_ctl.fsb.tcp_ip_hdr_len += sizeof(struct udphdr);
14313 			udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
14314 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
14315 			udp->uh_dport = tp->t_port;
14316 			rack->r_ctl.fsb.udp = udp;
14317 			rack->r_ctl.fsb.th = (struct tcphdr *)(udp + 1);
14318 		} else
14319 		{
14320 			rack->r_ctl.fsb.udp = NULL;
14321 			rack->r_ctl.fsb.th = (struct tcphdr *)(ip + 1);
14322 		}
14323 		tcpip_fillheaders(rack->rc_inp,
14324 				  tp->t_port,
14325 				  ip, rack->r_ctl.fsb.th);
14326 		rack->r_ctl.fsb.hoplimit = tptoinpcb(tp)->inp_ip_ttl;
14327 	}
14328 #endif
14329 	rack->r_ctl.fsb.recwin = lmin(lmax(sbspace(&tptosocket(tp)->so_rcv), 0),
14330 	    (long)TCP_MAXWIN << tp->rcv_scale);
14331 	rack->r_fsb_inited = 1;
14332 }
14333 
14334 static int
14335 rack_init_fsb(struct tcpcb *tp, struct tcp_rack *rack)
14336 {
14337 	/*
14338 	 * Allocate the larger of spaces V6 if available else just
14339 	 * V4 and include udphdr (overbook)
14340 	 */
14341 #ifdef INET6
14342 	rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + sizeof(struct udphdr);
14343 #else
14344 	rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct tcpiphdr) + sizeof(struct udphdr);
14345 #endif
14346 	rack->r_ctl.fsb.tcp_ip_hdr = malloc(rack->r_ctl.fsb.tcp_ip_hdr_len,
14347 					    M_TCPFSB, M_NOWAIT|M_ZERO);
14348 	if (rack->r_ctl.fsb.tcp_ip_hdr == NULL) {
14349 		return (ENOMEM);
14350 	}
14351 	rack->r_fsb_inited = 0;
14352 	return (0);
14353 }
14354 
14355 static void
14356 rack_log_hystart_event(struct tcp_rack *rack, uint32_t high_seq, uint8_t mod)
14357 {
14358 	/*
14359 	 * Types of logs (mod value)
14360 	 * 20 - Initial round setup
14361 	 * 21 - Rack declares a new round.
14362 	 */
14363 	struct tcpcb *tp;
14364 
14365 	tp = rack->rc_tp;
14366 	if (tcp_bblogging_on(tp)) {
14367 		union tcp_log_stackspecific log;
14368 		struct timeval tv;
14369 
14370 		memset(&log, 0, sizeof(log));
14371 		log.u_bbr.flex1 = rack->r_ctl.current_round;
14372 		log.u_bbr.flex2 = rack->r_ctl.roundends;
14373 		log.u_bbr.flex3 = high_seq;
14374 		log.u_bbr.flex4 = tp->snd_max;
14375 		log.u_bbr.flex8 = mod;
14376 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
14377 		log.u_bbr.cur_del_rate = rack->rc_tp->t_sndbytes;
14378 		log.u_bbr.delRate = rack->rc_tp->t_snd_rxt_bytes;
14379 		TCP_LOG_EVENTP(tp, NULL,
14380 		    &tptosocket(tp)->so_rcv,
14381 		    &tptosocket(tp)->so_snd,
14382 		    TCP_HYSTART, 0,
14383 		    0, &log, false, &tv);
14384 	}
14385 }
14386 
14387 static void
14388 rack_deferred_init(struct tcpcb *tp, struct tcp_rack *rack)
14389 {
14390 	rack->rack_deferred_inited = 1;
14391 	rack->r_ctl.roundends = tp->snd_max;
14392 	rack->r_ctl.rc_high_rwnd = tp->snd_wnd;
14393 	rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
14394 }
14395 
14396 static void
14397 rack_init_retransmit_value(struct tcp_rack *rack, int ctl)
14398 {
14399 	/* Retransmit bit controls.
14400 	 *
14401 	 * The setting of these values control one of
14402 	 * three settings you can have and dictate
14403 	 * how rack does retransmissions. Note this
14404 	 * is in *any* mode i.e. pacing on or off DGP
14405 	 * fixed rate pacing, or just bursting rack.
14406 	 *
14407 	 * 1 - Use full sized retransmits i.e. limit
14408 	 *     the size to whatever the pace_max_segments
14409 	 *     size is.
14410 	 *
14411 	 * 2 - Use pacer min granularity as a guide to
14412 	 *     the size combined with the current calculated
14413 	 *     goodput b/w measurement. So for example if
14414 	 *     the goodput is measured at 20Mbps we would
14415 	 *     calculate 8125 (pacer minimum 250usec in
14416 	 *     that b/w) and then round it up to the next
14417 	 *     MSS i.e. for 1448 mss 6 MSS or 8688 bytes.
14418 	 *
14419 	 * 0 - The rack default 1 MSS (anything not 0/1/2
14420 	 *     fall here too if we are setting via rack_init()).
14421 	 *
14422 	 */
14423 	if (ctl == 1) {
14424 		rack->full_size_rxt = 1;
14425 		rack->shape_rxt_to_pacing_min  = 0;
14426 	} else if (ctl == 2) {
14427 		rack->full_size_rxt = 0;
14428 		rack->shape_rxt_to_pacing_min  = 1;
14429 	} else {
14430 		rack->full_size_rxt = 0;
14431 		rack->shape_rxt_to_pacing_min  = 0;
14432 	}
14433 }
14434 
14435 static void
14436 rack_log_chg_info(struct tcpcb *tp, struct tcp_rack *rack, uint8_t mod,
14437 		  uint32_t flex1,
14438 		  uint32_t flex2,
14439 		  uint32_t flex3)
14440 {
14441 	if (tcp_bblogging_on(rack->rc_tp)) {
14442 		union tcp_log_stackspecific log;
14443 		struct timeval tv;
14444 
14445 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
14446 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
14447 		log.u_bbr.flex8 = mod;
14448 		log.u_bbr.flex1 = flex1;
14449 		log.u_bbr.flex2 = flex2;
14450 		log.u_bbr.flex3 = flex3;
14451 		tcp_log_event(tp, NULL, NULL, NULL, TCP_CHG_QUERY, 0,
14452 			       0, &log, false, NULL, __func__, __LINE__, &tv);
14453 	}
14454 }
14455 
14456 static int
14457 rack_chg_query(struct tcpcb *tp, struct tcp_query_resp *reqr)
14458 {
14459 	struct tcp_rack *rack;
14460 	struct rack_sendmap *rsm;
14461 	int i;
14462 
14463 
14464 	rack = (struct tcp_rack *)tp->t_fb_ptr;
14465 	switch (reqr->req) {
14466 	case TCP_QUERY_SENDMAP:
14467 		if ((reqr->req_param == tp->snd_max) ||
14468 		    (tp->snd_max == tp->snd_una)){
14469 			/* Unlikely */
14470 			return (0);
14471 		}
14472 		rsm = tqhash_find(rack->r_ctl.tqh, reqr->req_param);
14473 		if (rsm == NULL) {
14474 			/* Can't find that seq -- unlikely */
14475 			return (0);
14476 		}
14477 		reqr->sendmap_start = rsm->r_start;
14478 		reqr->sendmap_end = rsm->r_end;
14479 		reqr->sendmap_send_cnt = rsm->r_rtr_cnt;
14480 		reqr->sendmap_fas = rsm->r_fas;
14481 		if (reqr->sendmap_send_cnt > SNDMAP_NRTX)
14482 			reqr->sendmap_send_cnt = SNDMAP_NRTX;
14483 		for(i=0; i<reqr->sendmap_send_cnt; i++)
14484 			reqr->sendmap_time[i] = rsm->r_tim_lastsent[i];
14485 		reqr->sendmap_ack_arrival = rsm->r_ack_arrival;
14486 		reqr->sendmap_flags = rsm->r_flags & SNDMAP_MASK;
14487 		reqr->sendmap_r_rtr_bytes = rsm->r_rtr_bytes;
14488 		reqr->sendmap_dupacks = rsm->r_dupack;
14489 		rack_log_chg_info(tp, rack, 1,
14490 				  rsm->r_start,
14491 				  rsm->r_end,
14492 				  rsm->r_flags);
14493 		return(1);
14494 		break;
14495 	case TCP_QUERY_TIMERS_UP:
14496 		if (rack->r_ctl.rc_hpts_flags == 0) {
14497 			/* no timers up */
14498 			return (0);
14499 		}
14500 		reqr->timer_hpts_flags = rack->r_ctl.rc_hpts_flags;
14501 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
14502 			reqr->timer_pacing_to = rack->r_ctl.rc_last_output_to;
14503 		}
14504 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
14505 			reqr->timer_timer_exp = rack->r_ctl.rc_timer_exp;
14506 		}
14507 		rack_log_chg_info(tp, rack, 2,
14508 				  rack->r_ctl.rc_hpts_flags,
14509 				  rack->r_ctl.rc_last_output_to,
14510 				  rack->r_ctl.rc_timer_exp);
14511 		return (1);
14512 		break;
14513 	case TCP_QUERY_RACK_TIMES:
14514 		/* Reordering items */
14515 		reqr->rack_num_dsacks = rack->r_ctl.num_dsack;
14516 		reqr->rack_reorder_ts = rack->r_ctl.rc_reorder_ts;
14517 		/* Timerstamps and timers */
14518 		reqr->rack_rxt_last_time = rack->r_ctl.rc_tlp_rxt_last_time;
14519 		reqr->rack_min_rtt = rack->r_ctl.rc_rack_min_rtt;
14520 		reqr->rack_rtt = rack->rc_rack_rtt;
14521 		reqr->rack_tmit_time = rack->r_ctl.rc_rack_tmit_time;
14522 		reqr->rack_srtt_measured = rack->rc_srtt_measure_made;
14523 		/* PRR data */
14524 		reqr->rack_sacked = rack->r_ctl.rc_sacked;
14525 		reqr->rack_holes_rxt = rack->r_ctl.rc_holes_rxt;
14526 		reqr->rack_prr_delivered = rack->r_ctl.rc_prr_delivered;
14527 		reqr->rack_prr_recovery_fs = rack->r_ctl.rc_prr_recovery_fs;
14528 		reqr->rack_prr_sndcnt = rack->r_ctl.rc_prr_sndcnt;
14529 		reqr->rack_prr_out = rack->r_ctl.rc_prr_out;
14530 		/* TLP and persists info */
14531 		reqr->rack_tlp_out = rack->rc_tlp_in_progress;
14532 		reqr->rack_tlp_cnt_out = rack->r_ctl.rc_tlp_cnt_out;
14533 		if (rack->rc_in_persist) {
14534 			reqr->rack_time_went_idle = rack->r_ctl.rc_went_idle_time;
14535 			reqr->rack_in_persist = 1;
14536 		} else {
14537 			reqr->rack_time_went_idle = 0;
14538 			reqr->rack_in_persist = 0;
14539 		}
14540 		if (rack->r_wanted_output)
14541 			reqr->rack_wanted_output = 1;
14542 		else
14543 			reqr->rack_wanted_output = 0;
14544 		return (1);
14545 		break;
14546 	default:
14547 		return (-EINVAL);
14548 	}
14549 }
14550 
14551 static void
14552 rack_switch_failed(struct tcpcb *tp)
14553 {
14554 	/*
14555 	 * This method gets called if a stack switch was
14556 	 * attempted and it failed. We are left
14557 	 * but our hpts timers were stopped and we
14558 	 * need to validate time units and inp_flags2.
14559 	 */
14560 	struct inpcb *inp = tptoinpcb(tp);
14561 	struct tcp_rack *rack;
14562 	struct timeval tv;
14563 	uint32_t cts;
14564 	uint32_t toval;
14565 	struct hpts_diag diag;
14566 
14567 	rack = (struct tcp_rack *)tp->t_fb_ptr;
14568 	tcp_change_time_units(tp, TCP_TMR_GRANULARITY_USEC);
14569 	if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
14570 		inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
14571 	else
14572 		inp->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
14573 	if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
14574 		rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
14575 	if (inp->inp_in_hpts) {
14576 		/* Strange */
14577 		return;
14578 	}
14579 	cts = tcp_get_usecs(&tv);
14580 	if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
14581 		if (TSTMP_GT(rack->r_ctl.rc_last_output_to, cts)) {
14582 			toval = rack->r_ctl.rc_last_output_to - cts;
14583 		} else {
14584 			/* one slot please */
14585 			toval = HPTS_TICKS_PER_SLOT;
14586 		}
14587 	} else if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
14588 		if (TSTMP_GT(rack->r_ctl.rc_timer_exp, cts)) {
14589 			toval = rack->r_ctl.rc_timer_exp - cts;
14590 		} else {
14591 			/* one slot please */
14592 			toval = HPTS_TICKS_PER_SLOT;
14593 		}
14594 	} else
14595 		toval = HPTS_TICKS_PER_SLOT;
14596 	(void)tcp_hpts_insert_diag(inp, HPTS_USEC_TO_SLOTS(toval),
14597 				   __LINE__, &diag);
14598 	rack_log_hpts_diag(rack, cts, &diag, &tv);
14599 }
14600 
14601 static int
14602 rack_init_outstanding(struct tcpcb *tp, struct tcp_rack *rack, uint32_t us_cts, void *ptr)
14603 {
14604 	struct rack_sendmap *rsm, *ersm;
14605 	int insret __diagused;
14606 	/*
14607 	 * When initing outstanding, we must be quite careful
14608 	 * to not refer to tp->t_fb_ptr. This has the old rack
14609 	 * pointer in it, not the "new" one (when we are doing
14610 	 * a stack switch).
14611 	 */
14612 
14613 
14614 	if (tp->t_fb->tfb_chg_query == NULL) {
14615 		/* Create a send map for the current outstanding data */
14616 
14617 		rsm = rack_alloc(rack);
14618 		if (rsm == NULL) {
14619 			uma_zfree(rack_pcb_zone, ptr);
14620 			return (ENOMEM);
14621 		}
14622 		rsm->r_no_rtt_allowed = 1;
14623 		rsm->r_tim_lastsent[0] = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
14624 		rsm->r_rtr_cnt = 1;
14625 		rsm->r_rtr_bytes = 0;
14626 		if (tp->t_flags & TF_SENTFIN)
14627 			rsm->r_flags |= RACK_HAS_FIN;
14628 		rsm->r_end = tp->snd_max;
14629 		if (tp->snd_una == tp->iss) {
14630 			/* The data space is one beyond snd_una */
14631 			rsm->r_flags |= RACK_HAS_SYN;
14632 			rsm->r_start = tp->iss;
14633 			rsm->r_end = rsm->r_start + (tp->snd_max - tp->snd_una);
14634 		} else
14635 			rsm->r_start = tp->snd_una;
14636 		rsm->r_dupack = 0;
14637 		if (rack->rc_inp->inp_socket->so_snd.sb_mb != NULL) {
14638 			rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd, 0, &rsm->soff);
14639 			if (rsm->m) {
14640 				rsm->orig_m_len = rsm->m->m_len;
14641 				rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
14642 			} else {
14643 				rsm->orig_m_len = 0;
14644 				rsm->orig_t_space = 0;
14645 			}
14646 		} else {
14647 			/*
14648 			 * This can happen if we have a stand-alone FIN or
14649 			 *  SYN.
14650 			 */
14651 			rsm->m = NULL;
14652 			rsm->orig_m_len = 0;
14653 			rsm->orig_t_space = 0;
14654 			rsm->soff = 0;
14655 		}
14656 #ifdef INVARIANTS
14657 		if ((insret = tqhash_insert(rack->r_ctl.tqh, rsm)) != 0) {
14658 			panic("Insert in rb tree fails ret:%d rack:%p rsm:%p",
14659 			      insret, rack, rsm);
14660 		}
14661 #else
14662 		(void)tqhash_insert(rack->r_ctl.tqh, rsm);
14663 #endif
14664 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
14665 		rsm->r_in_tmap = 1;
14666 	} else {
14667 		/* We have a query mechanism, lets use it */
14668 		struct tcp_query_resp qr;
14669 		int i;
14670 		tcp_seq at;
14671 
14672 		at = tp->snd_una;
14673 		while (at != tp->snd_max) {
14674 			memset(&qr, 0, sizeof(qr));
14675 			qr.req = TCP_QUERY_SENDMAP;
14676 			qr.req_param = at;
14677 			if ((*tp->t_fb->tfb_chg_query)(tp, &qr) == 0)
14678 				break;
14679 			/* Move forward */
14680 			at = qr.sendmap_end;
14681 			/* Now lets build the entry for this one */
14682 			rsm = rack_alloc(rack);
14683 			if (rsm == NULL) {
14684 				uma_zfree(rack_pcb_zone, ptr);
14685 				return (ENOMEM);
14686 			}
14687 			memset(rsm, 0, sizeof(struct rack_sendmap));
14688 			/* Now configure the rsm and insert it */
14689 			rsm->r_dupack = qr.sendmap_dupacks;
14690 			rsm->r_start = qr.sendmap_start;
14691 			rsm->r_end = qr.sendmap_end;
14692 			if (qr.sendmap_fas)
14693 				rsm->r_fas = qr.sendmap_end;
14694 			else
14695 				rsm->r_fas = rsm->r_start - tp->snd_una;
14696 			/*
14697 			 * We have carefully aligned the bits
14698 			 * so that all we have to do is copy over
14699 			 * the bits with the mask.
14700 			 */
14701 			rsm->r_flags = qr.sendmap_flags & SNDMAP_MASK;
14702 			rsm->r_rtr_bytes = qr.sendmap_r_rtr_bytes;
14703 			rsm->r_rtr_cnt = qr.sendmap_send_cnt;
14704 			rsm->r_ack_arrival = qr.sendmap_ack_arrival;
14705 			for (i=0 ; i<rsm->r_rtr_cnt; i++)
14706 				rsm->r_tim_lastsent[i]	= qr.sendmap_time[i];
14707 			rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd,
14708 					   (rsm->r_start - tp->snd_una), &rsm->soff);
14709 			if (rsm->m) {
14710 				rsm->orig_m_len = rsm->m->m_len;
14711 				rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
14712 			} else {
14713 				rsm->orig_m_len = 0;
14714 				rsm->orig_t_space = 0;
14715 			}
14716 #ifdef INVARIANTS
14717 			if ((insret = tqhash_insert(rack->r_ctl.tqh, rsm)) != 0) {
14718 				panic("Insert in rb tree fails ret:%d rack:%p rsm:%p",
14719 				      insret, rack, rsm);
14720 			}
14721 #else
14722 			(void)tqhash_insert(rack->r_ctl.tqh, rsm);
14723 #endif
14724 			if ((rsm->r_flags & RACK_ACKED) == 0)  {
14725 				TAILQ_FOREACH(ersm, &rack->r_ctl.rc_tmap, r_tnext) {
14726 					if (ersm->r_tim_lastsent[(ersm->r_rtr_cnt-1)] >
14727 					    rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]) {
14728 						/*
14729 						 * If the existing ersm was sent at
14730 						 * a later time than the new one, then
14731 						 * the new one should appear ahead of this
14732 						 * ersm.
14733 						 */
14734 						rsm->r_in_tmap = 1;
14735 						TAILQ_INSERT_BEFORE(ersm, rsm, r_tnext);
14736 						break;
14737 					}
14738 				}
14739 				if (rsm->r_in_tmap == 0) {
14740 					/*
14741 					 * Not found so shove it on the tail.
14742 					 */
14743 					TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
14744 					rsm->r_in_tmap = 1;
14745 				}
14746  			} else {
14747 				if ((rack->r_ctl.rc_sacklast == NULL) ||
14748 				    (SEQ_GT(rsm->r_end, rack->r_ctl.rc_sacklast->r_end))) {
14749 					rack->r_ctl.rc_sacklast = rsm;
14750 				}
14751 			}
14752 			rack_log_chg_info(tp, rack, 3,
14753 					  rsm->r_start,
14754 					  rsm->r_end,
14755 					  rsm->r_flags);
14756 		}
14757 	}
14758 	return (0);
14759 }
14760 
14761 static void
14762 rack_translate_clamp_value(struct tcp_rack *rack, uint32_t optval)
14763 {
14764 	/*
14765 	 * P = percent bits
14766 	 * F = fill cw bit -- Toggle fillcw if this bit is set.
14767 	 * S = Segment bits
14768 	 * M = set max segment bit
14769 	 * U = Unclamined
14770 	 * C = If set to non-zero override the max number of clamps.
14771 	 * L = Bit to indicate if clamped gets lower.
14772 	 *
14773 	 * CCCC CCCCC UUUU UULF PPPP PPPP PPPP PPPP
14774 	 *
14775 	 * The lowest 3 nibbles is the perentage .1 - 6553.5%
14776 	 * where 10.1 = 101, max 6553.5
14777 	 * The upper 16 bits  holds some options.
14778 	 * The F bit will turn on fill-cw on if you are
14779 	 * not pacing, it will turn it off if dgp is on.
14780 	 * The L bit will change it so when clamped we get
14781 	 * the min(gp, lt-bw) for dgp.
14782 	 */
14783 	uint16_t per;
14784 
14785 	rack->r_ctl.saved_rxt_clamp_val = optval;
14786 	per = optval & 0x0000ffff;
14787 	rack->r_ctl.rxt_threshold = (uint64_t)(per & 0xffff);
14788 	if (optval > 0) {
14789 		uint16_t clamp_opt;
14790 
14791 		rack->excess_rxt_on = 1;
14792 		clamp_opt = ((optval & 0xffff0000) >> 16);
14793 		rack->r_ctl.clamp_options = clamp_opt & 0x00ff;
14794 		if (clamp_opt & 0xff00) {
14795 			/* A max clamps is also present */
14796 			rack->r_ctl.max_clamps = (clamp_opt >> 8);
14797 		} else {
14798 			/* No specified clamps means no limit */
14799 			rack->r_ctl.max_clamps = 0;
14800 		}
14801 		if (rack->r_ctl.clamp_options & 0x0002) {
14802 			rack->r_clamped_gets_lower  = 1;
14803 		} else {
14804 			rack->r_clamped_gets_lower  = 0;
14805 		}
14806 	} else {
14807 		/* Turn it off back to default */
14808 		rack->excess_rxt_on = 0;
14809 		rack->r_clamped_gets_lower  = 0;
14810 	}
14811 
14812 }
14813 
14814 
14815 static int32_t
14816 rack_init(struct tcpcb *tp, void **ptr)
14817 {
14818 	struct inpcb *inp = tptoinpcb(tp);
14819 	struct tcp_rack *rack = NULL;
14820 	uint32_t iwin, snt, us_cts;
14821 	int err, no_query;
14822 
14823 	/*
14824 	 * First are we the initial or are we a switched stack?
14825 	 * If we are initing via tcp_newtcppcb the ptr passed
14826 	 * will be tp->t_fb_ptr. If its a stack switch that
14827 	 * has a previous stack we can query it will be a local
14828 	 * var that will in the end be set into t_fb_ptr.
14829 	 */
14830 	if (ptr == &tp->t_fb_ptr)
14831 		no_query = 1;
14832 	else
14833 		no_query = 0;
14834 	*ptr = uma_zalloc(rack_pcb_zone, M_NOWAIT);
14835 	if (*ptr == NULL) {
14836 		/*
14837 		 * We need to allocate memory but cant. The INP and INP_INFO
14838 		 * locks and they are recursive (happens during setup. So a
14839 		 * scheme to drop the locks fails :(
14840 		 *
14841 		 */
14842 		return(ENOMEM);
14843 	}
14844 	memset(*ptr, 0, sizeof(struct tcp_rack));
14845 	rack = (struct tcp_rack *)*ptr;
14846 	rack->r_ctl.tqh = malloc(sizeof(struct tailq_hash), M_TCPFSB, M_NOWAIT);
14847 	if (rack->r_ctl.tqh == NULL) {
14848 		uma_zfree(rack_pcb_zone, rack);
14849 		return(ENOMEM);
14850 	}
14851 	tqhash_init(rack->r_ctl.tqh);
14852 	TAILQ_INIT(&rack->r_ctl.rc_free);
14853 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
14854 	rack->rc_tp = tp;
14855 	rack->rc_inp = inp;
14856 	/* Set the flag */
14857 	rack->r_is_v6 = (inp->inp_vflag & INP_IPV6) != 0;
14858 	/* Probably not needed but lets be sure */
14859 	rack_clear_rate_sample(rack);
14860 	/*
14861 	 * Save off the default values, socket options will poke
14862 	 * at these if pacing is not on or we have not yet
14863 	 * reached where pacing is on (gp_ready/fixed enabled).
14864 	 * When they get set into the CC module (when gp_ready
14865 	 * is enabled or we enable fixed) then we will set these
14866 	 * values into the CC and place in here the old values
14867 	 * so we have a restoral. Then we will set the flag
14868 	 * rc_pacing_cc_set. That way whenever we turn off pacing
14869 	 * or switch off this stack, we will know to go restore
14870 	 * the saved values.
14871 	 *
14872 	 * We specifically put into the beta the ecn value for pacing.
14873 	 */
14874 	rack->rc_new_rnd_needed = 1;
14875 	rack->r_ctl.rc_split_limit = V_tcp_map_split_limit;
14876 	rack->r_ctl.rc_saved_beta.beta = V_newreno_beta_ecn;
14877 	rack->r_ctl.rc_saved_beta.beta_ecn = V_newreno_beta_ecn;
14878 	/* We want abe like behavior as well */
14879 	rack->r_ctl.rc_saved_beta.newreno_flags |= CC_NEWRENO_BETA_ECN_ENABLED;
14880 	rack->r_ctl.rc_reorder_fade = rack_reorder_fade;
14881 	rack->rc_allow_data_af_clo = rack_ignore_data_after_close;
14882 	rack->r_ctl.rc_tlp_threshold = rack_tlp_thresh;
14883 	if (rack_rxt_clamp_thresh) {
14884 		rack_translate_clamp_value(rack, rack_rxt_clamp_thresh);
14885 		rack->excess_rxt_on = 1;
14886 	}
14887 	if (rack_uses_full_dgp_in_rec)
14888 		rack->r_ctl.full_dgp_in_rec = 1;
14889 	if (rack_fill_cw_state)
14890 		rack->rc_pace_to_cwnd = 1;
14891 	if (rack_pacing_min_seg)
14892 		rack->r_ctl.rc_user_set_min_segs = rack_pacing_min_seg;
14893 	if (use_rack_rr)
14894 		rack->use_rack_rr = 1;
14895 	if (rack_dnd_default) {
14896 		rack->rc_pace_dnd = 1;
14897 	}
14898 	if (V_tcp_delack_enabled)
14899 		tp->t_delayed_ack = 1;
14900 	else
14901 		tp->t_delayed_ack = 0;
14902 #ifdef TCP_ACCOUNTING
14903 	if (rack_tcp_accounting) {
14904 		tp->t_flags2 |= TF2_TCP_ACCOUNTING;
14905 	}
14906 #endif
14907 	rack->r_ctl.rack_per_upper_bound_ss = (uint8_t)rack_per_upper_bound_ss;
14908 	rack->r_ctl.rack_per_upper_bound_ca = (uint8_t)rack_per_upper_bound_ca;
14909 	if (rack_enable_shared_cwnd)
14910 		rack->rack_enable_scwnd = 1;
14911 	rack->r_ctl.pace_len_divisor = rack_default_pacing_divisor;
14912 	rack->rc_user_set_max_segs = rack_hptsi_segments;
14913 	rack->rc_force_max_seg = 0;
14914 	TAILQ_INIT(&rack->r_ctl.opt_list);
14915 	if (rack_hibeta_setting)
14916 		rack->rack_hibeta = 1;
14917 	rack->r_ctl.rc_reorder_shift = rack_reorder_thresh;
14918 	rack->r_ctl.rc_pkt_delay = rack_pkt_delay;
14919 	rack->r_ctl.rc_tlp_cwnd_reduce = rack_lower_cwnd_at_tlp;
14920 	rack->r_ctl.rc_lowest_us_rtt = 0xffffffff;
14921 	rack->r_ctl.rc_highest_us_rtt = 0;
14922 	rack->r_ctl.bw_rate_cap = rack_bw_rate_cap;
14923 	rack->r_ctl.timer_slop = TICKS_2_USEC(tcp_rexmit_slop);
14924 	if (rack_use_cmp_acks)
14925 		rack->r_use_cmp_ack = 1;
14926 	if (rack_disable_prr)
14927 		rack->rack_no_prr = 1;
14928 	if (rack_gp_no_rec_chg)
14929 		rack->rc_gp_no_rec_chg = 1;
14930 	if (rack_pace_every_seg && tcp_can_enable_pacing()) {
14931 		rack->rc_always_pace = 1;
14932 		if ((rack->gp_ready) && (rack->rc_always_pace && (rack->use_fixed_rate == 0)))
14933 			rack_set_cc_pacing(rack);
14934 	} else
14935 		rack->rc_always_pace = 0;
14936 	if (rack_enable_mqueue_for_nonpaced || rack->r_use_cmp_ack)
14937 		rack->r_mbuf_queue = 1;
14938 	else
14939 		rack->r_mbuf_queue = 0;
14940 	rack_set_pace_segments(tp, rack, __LINE__, NULL);
14941 	if (rack_limits_scwnd)
14942 		rack->r_limit_scw = 1;
14943 	else
14944 		rack->r_limit_scw = 0;
14945 	rack_init_retransmit_value(rack, rack_rxt_controls);
14946 	rack->rc_labc = V_tcp_abc_l_var;
14947 	rack->r_ctl.rc_rate_sample_method = rack_rate_sample_method;
14948 	rack->rack_tlp_threshold_use = rack_tlp_threshold_use;
14949 	rack->r_ctl.rc_prr_sendalot = rack_send_a_lot_in_prr;
14950 	rack->r_ctl.rc_min_to = rack_min_to;
14951 	microuptime(&rack->r_ctl.act_rcv_time);
14952 	rack->r_ctl.rc_last_time_decay = rack->r_ctl.act_rcv_time;
14953 	rack->rc_init_win = rack_default_init_window;
14954 	rack->r_ctl.rack_per_of_gp_ss = rack_per_of_gp_ss;
14955 	if (rack_hw_up_only)
14956 		rack->r_up_only = 1;
14957 	if (rack_do_dyn_mul) {
14958 		/* When dynamic adjustment is on CA needs to start at 100% */
14959 		rack->rc_gp_dyn_mul = 1;
14960 		if (rack_do_dyn_mul >= 100)
14961 			rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
14962 	} else
14963 		rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
14964 	rack->r_ctl.rack_per_of_gp_rec = rack_per_of_gp_rec;
14965 	rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
14966 	rack->r_ctl.rc_tlp_rxt_last_time = tcp_tv_to_mssectick(&rack->r_ctl.act_rcv_time);
14967 	setup_time_filter_small(&rack->r_ctl.rc_gp_min_rtt, FILTER_TYPE_MIN,
14968 				rack_probertt_filter_life);
14969 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
14970 	rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
14971 	rack->r_ctl.rc_time_of_last_probertt = us_cts;
14972 	rack->r_ctl.challenge_ack_ts = tcp_ts_getticks();
14973 	rack->r_ctl.rc_time_probertt_starts = 0;
14974 	if (rack_dsack_std_based & 0x1) {
14975 		/* Basically this means all rack timers are at least (srtt + 1/4 srtt) */
14976 		rack->rc_rack_tmr_std_based = 1;
14977 	}
14978 	if (rack_dsack_std_based & 0x2) {
14979 		/* Basically this means  rack timers are extended based on dsack by up to (2 * srtt) */
14980 		rack->rc_rack_use_dsack = 1;
14981 	}
14982 	/* We require at least one measurement, even if the sysctl is 0 */
14983 	if (rack_req_measurements)
14984 		rack->r_ctl.req_measurements = rack_req_measurements;
14985 	else
14986 		rack->r_ctl.req_measurements = 1;
14987 	if (rack_enable_hw_pacing)
14988 		rack->rack_hdw_pace_ena = 1;
14989 	if (rack_hw_rate_caps)
14990 		rack->r_rack_hw_rate_caps = 1;
14991 #ifdef TCP_SAD_DETECTION
14992 	rack->do_detection = 1;
14993 #else
14994 	rack->do_detection = 0;
14995 #endif
14996 	if (rack_non_rxt_use_cr)
14997 		rack->rack_rec_nonrxt_use_cr = 1;
14998 	/* Lets setup the fsb block */
14999 	err = rack_init_fsb(tp, rack);
15000 	if (err) {
15001 		uma_zfree(rack_pcb_zone, *ptr);
15002 		*ptr = NULL;
15003 		return (err);
15004 	}
15005 	if (rack_do_hystart) {
15006 		tp->t_ccv.flags |= CCF_HYSTART_ALLOWED;
15007 		if (rack_do_hystart > 1)
15008 			tp->t_ccv.flags |= CCF_HYSTART_CAN_SH_CWND;
15009 		if (rack_do_hystart > 2)
15010 			tp->t_ccv.flags |= CCF_HYSTART_CONS_SSTH;
15011 	}
15012 	/* Log what we will do with queries */
15013 	rack_log_chg_info(tp, rack, 7,
15014 			  no_query, 0, 0);
15015 	if (rack_def_profile)
15016 		rack_set_profile(rack, rack_def_profile);
15017 	/* Cancel the GP measurement in progress */
15018 	tp->t_flags &= ~TF_GPUTINPROG;
15019 	if ((tp->t_state != TCPS_CLOSED) &&
15020 	    (tp->t_state != TCPS_TIME_WAIT)) {
15021 		/*
15022 		 * We are already open, we may
15023 		 * need to adjust a few things.
15024 		 */
15025 		if (SEQ_GT(tp->snd_max, tp->iss))
15026 			snt = tp->snd_max - tp->iss;
15027 		else
15028 			snt = 0;
15029 		iwin = rc_init_window(rack);
15030 		if ((snt < iwin) &&
15031 		    (no_query == 1)) {
15032 			/* We are not past the initial window
15033 			 * on the first init (i.e. a stack switch
15034 			 * has not yet occured) so we need to make
15035 			 * sure cwnd and ssthresh is correct.
15036 			 */
15037 			if (tp->snd_cwnd < iwin)
15038 				tp->snd_cwnd = iwin;
15039 			/*
15040 			 * If we are within the initial window
15041 			 * we want ssthresh to be unlimited. Setting
15042 			 * it to the rwnd (which the default stack does
15043 			 * and older racks) is not really a good idea
15044 			 * since we want to be in SS and grow both the
15045 			 * cwnd and the rwnd (via dynamic rwnd growth). If
15046 			 * we set it to the rwnd then as the peer grows its
15047 			 * rwnd we will be stuck in CA and never hit SS.
15048 			 *
15049 			 * Its far better to raise it up high (this takes the
15050 			 * risk that there as been a loss already, probably
15051 			 * we should have an indicator in all stacks of loss
15052 			 * but we don't), but considering the normal use this
15053 			 * is a risk worth taking. The consequences of not
15054 			 * hitting SS are far worse than going one more time
15055 			 * into it early on (before we have sent even a IW).
15056 			 * It is highly unlikely that we will have had a loss
15057 			 * before getting the IW out.
15058 			 */
15059 			tp->snd_ssthresh = 0xffffffff;
15060 		}
15061 		/*
15062 		 * Any init based on sequence numbers
15063 		 * should be done in the deferred init path
15064 		 * since we can be CLOSED and not have them
15065 		 * inited when rack_init() is called. We
15066 		 * are not closed so lets call it.
15067 		 */
15068 		rack_deferred_init(tp, rack);
15069 	}
15070 	if ((tp->t_state != TCPS_CLOSED) &&
15071 	    (tp->t_state != TCPS_TIME_WAIT) &&
15072 	    (no_query == 0) &&
15073 	    (tp->snd_una != tp->snd_max))  {
15074 		err = rack_init_outstanding(tp, rack, us_cts, *ptr);
15075 		if (err) {
15076 			*ptr = NULL;
15077 			return(err);
15078 		}
15079 	}
15080 	rack_stop_all_timers(tp, rack);
15081 	/* Setup all the inp_flags2 */
15082 	if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
15083 		tptoinpcb(tp)->inp_flags2 |= INP_SUPPORTS_MBUFQ;
15084 	else
15085 		tptoinpcb(tp)->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
15086 	if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
15087 		rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
15088 	/*
15089 	 * Timers in Rack are kept in microseconds so lets
15090 	 * convert any initial incoming variables
15091 	 * from ticks into usecs. Note that we
15092 	 * also change the values of t_srtt and t_rttvar, if
15093 	 * they are non-zero. They are kept with a 5
15094 	 * bit decimal so we have to carefully convert
15095 	 * these to get the full precision.
15096 	 */
15097 	rack_convert_rtts(tp);
15098 	rack_log_hystart_event(rack, rack->r_ctl.roundends, 20);
15099 	if ((tptoinpcb(tp)->inp_flags & INP_DROPPED) == 0) {
15100 		/* We do not start any timers on DROPPED connections */
15101 		if (tp->t_fb->tfb_chg_query == NULL) {
15102 			rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
15103 		} else {
15104 			struct tcp_query_resp qr;
15105 			int ret;
15106 
15107 			memset(&qr, 0, sizeof(qr));
15108 
15109 			/* Get the misc time stamps and such for rack */
15110 			qr.req = TCP_QUERY_RACK_TIMES;
15111 			ret = (*tp->t_fb->tfb_chg_query)(tp, &qr);
15112 			if (ret == 1) {
15113 				rack->r_ctl.rc_reorder_ts = qr.rack_reorder_ts;
15114 				rack->r_ctl.num_dsack  = qr.rack_num_dsacks;
15115 				rack->r_ctl.rc_tlp_rxt_last_time = qr.rack_rxt_last_time;
15116 				rack->r_ctl.rc_rack_min_rtt = qr.rack_min_rtt;
15117 				rack->rc_rack_rtt = qr.rack_rtt;
15118 				rack->r_ctl.rc_rack_tmit_time = qr.rack_tmit_time;
15119 				rack->r_ctl.rc_sacked = qr.rack_sacked;
15120 				rack->r_ctl.rc_holes_rxt = qr.rack_holes_rxt;
15121 				rack->r_ctl.rc_prr_delivered = qr.rack_prr_delivered;
15122 				rack->r_ctl.rc_prr_recovery_fs = qr.rack_prr_recovery_fs;
15123 				rack->r_ctl.rc_prr_sndcnt = qr.rack_prr_sndcnt;
15124 				rack->r_ctl.rc_prr_out = qr.rack_prr_out;
15125 				if (qr.rack_tlp_out) {
15126 					rack->rc_tlp_in_progress = 1;
15127 					rack->r_ctl.rc_tlp_cnt_out = qr.rack_tlp_cnt_out;
15128 				} else {
15129 					rack->rc_tlp_in_progress = 0;
15130 					rack->r_ctl.rc_tlp_cnt_out = 0;
15131 				}
15132 				if (qr.rack_srtt_measured)
15133 					rack->rc_srtt_measure_made = 1;
15134 				if (qr.rack_in_persist == 1) {
15135 					rack->r_ctl.rc_went_idle_time = qr.rack_time_went_idle;
15136 #ifdef NETFLIX_SHARED_CWND
15137 					if (rack->r_ctl.rc_scw) {
15138 						tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
15139 						rack->rack_scwnd_is_idle = 1;
15140 					}
15141 #endif
15142 					rack->r_ctl.persist_lost_ends = 0;
15143 					rack->probe_not_answered = 0;
15144 					rack->forced_ack = 0;
15145 					tp->t_rxtshift = 0;
15146 					rack->rc_in_persist = 1;
15147 					RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
15148 							   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
15149 				}
15150 				if (qr.rack_wanted_output)
15151 					rack->r_wanted_output = 1;
15152 				rack_log_chg_info(tp, rack, 6,
15153 						  qr.rack_min_rtt,
15154 						  qr.rack_rtt,
15155 						  qr.rack_reorder_ts);
15156 			}
15157 			/* Get the old stack timers */
15158 			qr.req_param = 0;
15159 			qr.req = TCP_QUERY_TIMERS_UP;
15160 			ret = (*tp->t_fb->tfb_chg_query)(tp, &qr);
15161 			if (ret) {
15162 				/*
15163 				 * non-zero return means we have a timer('s)
15164 				 * to start. Zero means no timer (no keepalive
15165 				 * I suppose).
15166 				 */
15167 				uint32_t tov = 0;
15168 
15169 				rack->r_ctl.rc_hpts_flags = qr.timer_hpts_flags;
15170 				if (qr.timer_hpts_flags & PACE_PKT_OUTPUT) {
15171 					rack->r_ctl.rc_last_output_to = qr.timer_pacing_to;
15172 					if (TSTMP_GT(qr.timer_pacing_to, us_cts))
15173 						tov = qr.timer_pacing_to - us_cts;
15174 					else
15175 						tov = HPTS_TICKS_PER_SLOT;
15176 				}
15177 				if (qr.timer_hpts_flags & PACE_TMR_MASK) {
15178 					rack->r_ctl.rc_timer_exp = qr.timer_timer_exp;
15179 					if (tov == 0) {
15180 						if (TSTMP_GT(qr.timer_timer_exp, us_cts))
15181 							tov = qr.timer_timer_exp - us_cts;
15182 						else
15183 							tov = HPTS_TICKS_PER_SLOT;
15184 					}
15185 				}
15186 				rack_log_chg_info(tp, rack, 4,
15187 						  rack->r_ctl.rc_hpts_flags,
15188 						  rack->r_ctl.rc_last_output_to,
15189 						  rack->r_ctl.rc_timer_exp);
15190 				if (tov) {
15191 					struct hpts_diag diag;
15192 
15193 					(void)tcp_hpts_insert_diag(rack->rc_inp, HPTS_USEC_TO_SLOTS(tov),
15194 								   __LINE__, &diag);
15195 					rack_log_hpts_diag(rack, us_cts, &diag, &rack->r_ctl.act_rcv_time);
15196 				}
15197 			}
15198 		}
15199 		rack_log_rtt_shrinks(rack,  us_cts,  tp->t_rxtcur,
15200 				     __LINE__, RACK_RTTS_INIT);
15201 	}
15202 	return (0);
15203 }
15204 
15205 static int
15206 rack_handoff_ok(struct tcpcb *tp)
15207 {
15208 	if ((tp->t_state == TCPS_CLOSED) ||
15209 	    (tp->t_state == TCPS_LISTEN)) {
15210 		/* Sure no problem though it may not stick */
15211 		return (0);
15212 	}
15213 	if ((tp->t_state == TCPS_SYN_SENT) ||
15214 	    (tp->t_state == TCPS_SYN_RECEIVED)) {
15215 		/*
15216 		 * We really don't know if you support sack,
15217 		 * you have to get to ESTAB or beyond to tell.
15218 		 */
15219 		return (EAGAIN);
15220 	}
15221 	if ((tp->t_flags & TF_SENTFIN) && ((tp->snd_max - tp->snd_una) > 1)) {
15222 		/*
15223 		 * Rack will only send a FIN after all data is acknowledged.
15224 		 * So in this case we have more data outstanding. We can't
15225 		 * switch stacks until either all data and only the FIN
15226 		 * is left (in which case rack_init() now knows how
15227 		 * to deal with that) <or> all is acknowledged and we
15228 		 * are only left with incoming data, though why you
15229 		 * would want to switch to rack after all data is acknowledged
15230 		 * I have no idea (rrs)!
15231 		 */
15232 		return (EAGAIN);
15233 	}
15234 	if ((tp->t_flags & TF_SACK_PERMIT) || rack_sack_not_required){
15235 		return (0);
15236 	}
15237 	/*
15238 	 * If we reach here we don't do SACK on this connection so we can
15239 	 * never do rack.
15240 	 */
15241 	return (EINVAL);
15242 }
15243 
15244 static void
15245 rack_fini(struct tcpcb *tp, int32_t tcb_is_purged)
15246 {
15247 
15248 	if (tp->t_fb_ptr) {
15249 		uint32_t cnt_free = 0;
15250 		struct tcp_rack *rack;
15251 		struct rack_sendmap *rsm;
15252 
15253 		tcp_handle_orphaned_packets(tp);
15254 		tp->t_flags &= ~TF_FORCEDATA;
15255 		rack = (struct tcp_rack *)tp->t_fb_ptr;
15256 		rack_log_pacing_delay_calc(rack,
15257 					   0,
15258 					   0,
15259 					   0,
15260 					   rack_get_gp_est(rack), /* delRate */
15261 					   rack_get_lt_bw(rack), /* rttProp */
15262 					   20, __LINE__, NULL, 0);
15263 #ifdef NETFLIX_SHARED_CWND
15264 		if (rack->r_ctl.rc_scw) {
15265 			uint32_t limit;
15266 
15267 			if (rack->r_limit_scw)
15268 				limit = max(1, rack->r_ctl.rc_lowest_us_rtt);
15269 			else
15270 				limit = 0;
15271 			tcp_shared_cwnd_free_full(tp, rack->r_ctl.rc_scw,
15272 						  rack->r_ctl.rc_scw_index,
15273 						  limit);
15274 			rack->r_ctl.rc_scw = NULL;
15275 		}
15276 #endif
15277 		if (rack->r_ctl.fsb.tcp_ip_hdr) {
15278 			free(rack->r_ctl.fsb.tcp_ip_hdr, M_TCPFSB);
15279 			rack->r_ctl.fsb.tcp_ip_hdr = NULL;
15280 			rack->r_ctl.fsb.th = NULL;
15281 		}
15282 		if (rack->rc_always_pace) {
15283 			tcp_decrement_paced_conn();
15284 			rack_undo_cc_pacing(rack);
15285 			rack->rc_always_pace = 0;
15286 		}
15287 		/* Clean up any options if they were not applied */
15288 		while (!TAILQ_EMPTY(&rack->r_ctl.opt_list)) {
15289 			struct deferred_opt_list *dol;
15290 
15291 			dol = TAILQ_FIRST(&rack->r_ctl.opt_list);
15292 			TAILQ_REMOVE(&rack->r_ctl.opt_list, dol, next);
15293 			free(dol, M_TCPDO);
15294 		}
15295 		/* rack does not use force data but other stacks may clear it */
15296 		if (rack->r_ctl.crte != NULL) {
15297 			tcp_rel_pacing_rate(rack->r_ctl.crte, tp);
15298 			rack->rack_hdrw_pacing = 0;
15299 			rack->r_ctl.crte = NULL;
15300 		}
15301 #ifdef TCP_BLACKBOX
15302 		tcp_log_flowend(tp);
15303 #endif
15304 		/*
15305 		 * Lets take a different approach to purging just
15306 		 * get each one and free it like a cum-ack would and
15307 		 * not use a foreach loop.
15308 		 */
15309 		rsm = tqhash_min(rack->r_ctl.tqh);
15310 		while (rsm) {
15311 			tqhash_remove(rack->r_ctl.tqh, rsm, REMOVE_TYPE_CUMACK);
15312 			rack->r_ctl.rc_num_maps_alloced--;
15313 			uma_zfree(rack_zone, rsm);
15314 			rsm = tqhash_min(rack->r_ctl.tqh);
15315 		}
15316 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
15317 		while (rsm) {
15318 			TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
15319 			rack->r_ctl.rc_num_maps_alloced--;
15320 			rack->rc_free_cnt--;
15321 			cnt_free++;
15322 			uma_zfree(rack_zone, rsm);
15323 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
15324 		}
15325 		if ((rack->r_ctl.rc_num_maps_alloced > 0) &&
15326 		    (tcp_bblogging_on(tp))) {
15327 			union tcp_log_stackspecific log;
15328 			struct timeval tv;
15329 
15330 			memset(&log.u_bbr, 0, sizeof(log.u_bbr));
15331 			log.u_bbr.flex8 = 10;
15332 			log.u_bbr.flex1 = rack->r_ctl.rc_num_maps_alloced;
15333 			log.u_bbr.flex2 = rack->rc_free_cnt;
15334 			log.u_bbr.flex3 = cnt_free;
15335 			log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
15336 			rsm = tqhash_min(rack->r_ctl.tqh);
15337 			log.u_bbr.delRate = (uint64_t)rsm;
15338 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
15339 			log.u_bbr.cur_del_rate = (uint64_t)rsm;
15340 			log.u_bbr.timeStamp = tcp_get_usecs(&tv);
15341 			log.u_bbr.pkt_epoch = __LINE__;
15342 			(void)tcp_log_event(tp, NULL, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
15343 					     0, &log, false, NULL, NULL, 0, &tv);
15344 		}
15345 		KASSERT((rack->r_ctl.rc_num_maps_alloced == 0),
15346 			("rack:%p num_aloc:%u after freeing all?",
15347 			 rack,
15348 			 rack->r_ctl.rc_num_maps_alloced));
15349 		rack->rc_free_cnt = 0;
15350 		free(rack->r_ctl.tqh, M_TCPFSB);
15351 		rack->r_ctl.tqh = NULL;
15352 		uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
15353 		tp->t_fb_ptr = NULL;
15354 	}
15355 	/* Make sure snd_nxt is correctly set */
15356 	tp->snd_nxt = tp->snd_max;
15357 }
15358 
15359 static void
15360 rack_set_state(struct tcpcb *tp, struct tcp_rack *rack)
15361 {
15362 	if ((rack->r_state == TCPS_CLOSED) && (tp->t_state != TCPS_CLOSED)) {
15363 		rack->r_is_v6 = (tptoinpcb(tp)->inp_vflag & INP_IPV6) != 0;
15364 	}
15365 	switch (tp->t_state) {
15366 	case TCPS_SYN_SENT:
15367 		rack->r_state = TCPS_SYN_SENT;
15368 		rack->r_substate = rack_do_syn_sent;
15369 		break;
15370 	case TCPS_SYN_RECEIVED:
15371 		rack->r_state = TCPS_SYN_RECEIVED;
15372 		rack->r_substate = rack_do_syn_recv;
15373 		break;
15374 	case TCPS_ESTABLISHED:
15375 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
15376 		rack->r_state = TCPS_ESTABLISHED;
15377 		rack->r_substate = rack_do_established;
15378 		break;
15379 	case TCPS_CLOSE_WAIT:
15380 		rack->r_state = TCPS_CLOSE_WAIT;
15381 		rack->r_substate = rack_do_close_wait;
15382 		break;
15383 	case TCPS_FIN_WAIT_1:
15384 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
15385 		rack->r_state = TCPS_FIN_WAIT_1;
15386 		rack->r_substate = rack_do_fin_wait_1;
15387 		break;
15388 	case TCPS_CLOSING:
15389 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
15390 		rack->r_state = TCPS_CLOSING;
15391 		rack->r_substate = rack_do_closing;
15392 		break;
15393 	case TCPS_LAST_ACK:
15394 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
15395 		rack->r_state = TCPS_LAST_ACK;
15396 		rack->r_substate = rack_do_lastack;
15397 		break;
15398 	case TCPS_FIN_WAIT_2:
15399 		rack->r_state = TCPS_FIN_WAIT_2;
15400 		rack->r_substate = rack_do_fin_wait_2;
15401 		break;
15402 	case TCPS_LISTEN:
15403 	case TCPS_CLOSED:
15404 	case TCPS_TIME_WAIT:
15405 	default:
15406 		break;
15407 	};
15408 	if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
15409 		rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
15410 
15411 }
15412 
15413 static void
15414 rack_timer_audit(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb)
15415 {
15416 	/*
15417 	 * We received an ack, and then did not
15418 	 * call send or were bounced out due to the
15419 	 * hpts was running. Now a timer is up as well, is
15420 	 * it the right timer?
15421 	 */
15422 	struct rack_sendmap *rsm;
15423 	int tmr_up;
15424 
15425 	tmr_up = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
15426 	if (rack->rc_in_persist && (tmr_up == PACE_TMR_PERSIT))
15427 		return;
15428 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
15429 	if (((rsm == NULL) || (tp->t_state < TCPS_ESTABLISHED)) &&
15430 	    (tmr_up == PACE_TMR_RXT)) {
15431 		/* Should be an RXT */
15432 		return;
15433 	}
15434 	if (rsm == NULL) {
15435 		/* Nothing outstanding? */
15436 		if (tp->t_flags & TF_DELACK) {
15437 			if (tmr_up == PACE_TMR_DELACK)
15438 				/* We are supposed to have delayed ack up and we do */
15439 				return;
15440 		} else if (sbavail(&tptosocket(tp)->so_snd) && (tmr_up == PACE_TMR_RXT)) {
15441 			/*
15442 			 * if we hit enobufs then we would expect the possibility
15443 			 * of nothing outstanding and the RXT up (and the hptsi timer).
15444 			 */
15445 			return;
15446 		} else if (((V_tcp_always_keepalive ||
15447 			     rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
15448 			    (tp->t_state <= TCPS_CLOSING)) &&
15449 			   (tmr_up == PACE_TMR_KEEP) &&
15450 			   (tp->snd_max == tp->snd_una)) {
15451 			/* We should have keep alive up and we do */
15452 			return;
15453 		}
15454 	}
15455 	if (SEQ_GT(tp->snd_max, tp->snd_una) &&
15456 		   ((tmr_up == PACE_TMR_TLP) ||
15457 		    (tmr_up == PACE_TMR_RACK) ||
15458 		    (tmr_up == PACE_TMR_RXT))) {
15459 		/*
15460 		 * Either a Rack, TLP or RXT is fine if  we
15461 		 * have outstanding data.
15462 		 */
15463 		return;
15464 	} else if (tmr_up == PACE_TMR_DELACK) {
15465 		/*
15466 		 * If the delayed ack was going to go off
15467 		 * before the rtx/tlp/rack timer were going to
15468 		 * expire, then that would be the timer in control.
15469 		 * Note we don't check the time here trusting the
15470 		 * code is correct.
15471 		 */
15472 		return;
15473 	}
15474 	/*
15475 	 * Ok the timer originally started is not what we want now.
15476 	 * We will force the hpts to be stopped if any, and restart
15477 	 * with the slot set to what was in the saved slot.
15478 	 */
15479 	if (tcp_in_hpts(rack->rc_inp)) {
15480 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
15481 			uint32_t us_cts;
15482 
15483 			us_cts = tcp_get_usecs(NULL);
15484 			if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
15485 				rack->r_early = 1;
15486 				rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
15487 			}
15488 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
15489 		}
15490 		tcp_hpts_remove(rack->rc_inp);
15491 	}
15492 	rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
15493 	rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
15494 }
15495 
15496 
15497 static void
15498 rack_do_win_updates(struct tcpcb *tp, struct tcp_rack *rack, uint32_t tiwin, uint32_t seq, uint32_t ack, uint32_t cts)
15499 {
15500 	if ((SEQ_LT(tp->snd_wl1, seq) ||
15501 	    (tp->snd_wl1 == seq && (SEQ_LT(tp->snd_wl2, ack) ||
15502 	    (tp->snd_wl2 == ack && tiwin > tp->snd_wnd))))) {
15503 		/* keep track of pure window updates */
15504 		if ((tp->snd_wl2 == ack) && (tiwin > tp->snd_wnd))
15505 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
15506 		tp->snd_wnd = tiwin;
15507 		rack_validate_fo_sendwin_up(tp, rack);
15508 		tp->snd_wl1 = seq;
15509 		tp->snd_wl2 = ack;
15510 		if (tp->snd_wnd > tp->max_sndwnd)
15511 			tp->max_sndwnd = tp->snd_wnd;
15512 	    rack->r_wanted_output = 1;
15513 	} else if ((tp->snd_wl2 == ack) && (tiwin < tp->snd_wnd)) {
15514 		tp->snd_wnd = tiwin;
15515 		rack_validate_fo_sendwin_up(tp, rack);
15516 		tp->snd_wl1 = seq;
15517 		tp->snd_wl2 = ack;
15518 	} else {
15519 		/* Not a valid win update */
15520 		return;
15521 	}
15522 	if (tp->snd_wnd > tp->max_sndwnd)
15523 		tp->max_sndwnd = tp->snd_wnd;
15524 	/* Do we exit persists? */
15525 	if ((rack->rc_in_persist != 0) &&
15526 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
15527 				rack->r_ctl.rc_pace_min_segs))) {
15528 		rack_exit_persist(tp, rack, cts);
15529 	}
15530 	/* Do we enter persists? */
15531 	if ((rack->rc_in_persist == 0) &&
15532 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
15533 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
15534 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
15535 	    sbavail(&tptosocket(tp)->so_snd) &&
15536 	    (sbavail(&tptosocket(tp)->so_snd) > tp->snd_wnd)) {
15537 		/*
15538 		 * Here the rwnd is less than
15539 		 * the pacing size, we are established,
15540 		 * nothing is outstanding, and there is
15541 		 * data to send. Enter persists.
15542 		 */
15543 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime, ack);
15544 	}
15545 }
15546 
15547 static void
15548 rack_log_input_packet(struct tcpcb *tp, struct tcp_rack *rack, struct tcp_ackent *ae, int ackval, uint32_t high_seq)
15549 {
15550 
15551 	if (tcp_bblogging_on(rack->rc_tp)) {
15552 		struct inpcb *inp = tptoinpcb(tp);
15553 		union tcp_log_stackspecific log;
15554 		struct timeval ltv;
15555 		char tcp_hdr_buf[60];
15556 		struct tcphdr *th;
15557 		struct timespec ts;
15558 		uint32_t orig_snd_una;
15559 		uint8_t xx = 0;
15560 
15561 #ifdef TCP_REQUEST_TRK
15562 		struct http_sendfile_track *http_req;
15563 
15564 		if (SEQ_GT(ae->ack, tp->snd_una)) {
15565 			http_req = tcp_http_find_req_for_seq(tp, (ae->ack-1));
15566 		} else {
15567 			http_req = tcp_http_find_req_for_seq(tp, ae->ack);
15568 		}
15569 #endif
15570 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
15571 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
15572 		if (rack->rack_no_prr == 0)
15573 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
15574 		else
15575 			log.u_bbr.flex1 = 0;
15576 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
15577 		log.u_bbr.use_lt_bw <<= 1;
15578 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
15579 		log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
15580 		log.u_bbr.bbr_state = rack->rc_free_cnt;
15581 		log.u_bbr.inflight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
15582 		log.u_bbr.pkts_out = tp->t_maxseg;
15583 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
15584 		log.u_bbr.flex7 = 1;
15585 		log.u_bbr.lost = ae->flags;
15586 		log.u_bbr.cwnd_gain = ackval;
15587 		log.u_bbr.pacing_gain = 0x2;
15588 		if (ae->flags & TSTMP_HDWR) {
15589 			/* Record the hardware timestamp if present */
15590 			log.u_bbr.flex3 = M_TSTMP;
15591 			ts.tv_sec = ae->timestamp / 1000000000;
15592 			ts.tv_nsec = ae->timestamp % 1000000000;
15593 			ltv.tv_sec = ts.tv_sec;
15594 			ltv.tv_usec = ts.tv_nsec / 1000;
15595 			log.u_bbr.lt_epoch = tcp_tv_to_usectick(&ltv);
15596 		} else if (ae->flags & TSTMP_LRO) {
15597 			/* Record the LRO the arrival timestamp */
15598 			log.u_bbr.flex3 = M_TSTMP_LRO;
15599 			ts.tv_sec = ae->timestamp / 1000000000;
15600 			ts.tv_nsec = ae->timestamp % 1000000000;
15601 			ltv.tv_sec = ts.tv_sec;
15602 			ltv.tv_usec = ts.tv_nsec / 1000;
15603 			log.u_bbr.flex5 = tcp_tv_to_usectick(&ltv);
15604 		}
15605 		log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
15606 		/* Log the rcv time */
15607 		log.u_bbr.delRate = ae->timestamp;
15608 #ifdef TCP_REQUEST_TRK
15609 		log.u_bbr.applimited = tp->t_http_closed;
15610 		log.u_bbr.applimited <<= 8;
15611 		log.u_bbr.applimited |= tp->t_http_open;
15612 		log.u_bbr.applimited <<= 8;
15613 		log.u_bbr.applimited |= tp->t_http_req;
15614 		if (http_req) {
15615 			/* Copy out any client req info */
15616 			/* seconds */
15617 			log.u_bbr.pkt_epoch = (http_req->localtime / HPTS_USEC_IN_SEC);
15618 			/* useconds */
15619 			log.u_bbr.delivered = (http_req->localtime % HPTS_USEC_IN_SEC);
15620 			log.u_bbr.rttProp = http_req->timestamp;
15621 			log.u_bbr.cur_del_rate = http_req->start;
15622 			if (http_req->flags & TCP_HTTP_TRACK_FLG_OPEN) {
15623 				log.u_bbr.flex8 |= 1;
15624 			} else {
15625 				log.u_bbr.flex8 |= 2;
15626 				log.u_bbr.bw_inuse = http_req->end;
15627 			}
15628 			log.u_bbr.flex6 = http_req->start_seq;
15629 			if (http_req->flags & TCP_HTTP_TRACK_FLG_COMP) {
15630 				log.u_bbr.flex8 |= 4;
15631 				log.u_bbr.epoch = http_req->end_seq;
15632 			}
15633 		}
15634 #endif
15635 		memset(tcp_hdr_buf, 0, sizeof(tcp_hdr_buf));
15636 		th = (struct tcphdr *)tcp_hdr_buf;
15637 		th->th_seq = ae->seq;
15638 		th->th_ack = ae->ack;
15639 		th->th_win = ae->win;
15640 		/* Now fill in the ports */
15641 		th->th_sport = inp->inp_fport;
15642 		th->th_dport = inp->inp_lport;
15643 		tcp_set_flags(th, ae->flags);
15644 		/* Now do we have a timestamp option? */
15645 		if (ae->flags & HAS_TSTMP) {
15646 			u_char *cp;
15647 			uint32_t val;
15648 
15649 			th->th_off = ((sizeof(struct tcphdr) + TCPOLEN_TSTAMP_APPA) >> 2);
15650 			cp = (u_char *)(th + 1);
15651 			*cp = TCPOPT_NOP;
15652 			cp++;
15653 			*cp = TCPOPT_NOP;
15654 			cp++;
15655 			*cp = TCPOPT_TIMESTAMP;
15656 			cp++;
15657 			*cp = TCPOLEN_TIMESTAMP;
15658 			cp++;
15659 			val = htonl(ae->ts_value);
15660 			bcopy((char *)&val,
15661 			      (char *)cp, sizeof(uint32_t));
15662 			val = htonl(ae->ts_echo);
15663 			bcopy((char *)&val,
15664 			      (char *)(cp + 4), sizeof(uint32_t));
15665 		} else
15666 			th->th_off = (sizeof(struct tcphdr) >> 2);
15667 
15668 		/*
15669 		 * For sane logging we need to play a little trick.
15670 		 * If the ack were fully processed we would have moved
15671 		 * snd_una to high_seq, but since compressed acks are
15672 		 * processed in two phases, at this point (logging) snd_una
15673 		 * won't be advanced. So we would see multiple acks showing
15674 		 * the advancement. We can prevent that by "pretending" that
15675 		 * snd_una was advanced and then un-advancing it so that the
15676 		 * logging code has the right value for tlb_snd_una.
15677 		 */
15678 		if (tp->snd_una != high_seq) {
15679 			orig_snd_una = tp->snd_una;
15680 			tp->snd_una = high_seq;
15681 			xx = 1;
15682 		} else
15683 			xx = 0;
15684 		TCP_LOG_EVENTP(tp, th,
15685 			       &tptosocket(tp)->so_rcv,
15686 			       &tptosocket(tp)->so_snd, TCP_LOG_IN, 0,
15687 			       0, &log, true, &ltv);
15688 		if (xx) {
15689 			tp->snd_una = orig_snd_una;
15690 		}
15691 	}
15692 
15693 }
15694 
15695 static void
15696 rack_handle_probe_response(struct tcp_rack *rack, uint32_t tiwin, uint32_t us_cts)
15697 {
15698 	uint32_t us_rtt;
15699 	/*
15700 	 * A persist or keep-alive was forced out, update our
15701 	 * min rtt time. Note now worry about lost responses.
15702 	 * When a subsequent keep-alive or persist times out
15703 	 * and forced_ack is still on, then the last probe
15704 	 * was not responded to. In such cases we have a
15705 	 * sysctl that controls the behavior. Either we apply
15706 	 * the rtt but with reduced confidence (0). Or we just
15707 	 * plain don't apply the rtt estimate. Having data flow
15708 	 * will clear the probe_not_answered flag i.e. cum-ack
15709 	 * move forward <or> exiting and reentering persists.
15710 	 */
15711 
15712 	rack->forced_ack = 0;
15713 	rack->rc_tp->t_rxtshift = 0;
15714 	if ((rack->rc_in_persist &&
15715 	     (tiwin == rack->rc_tp->snd_wnd)) ||
15716 	    (rack->rc_in_persist == 0)) {
15717 		/*
15718 		 * In persists only apply the RTT update if this is
15719 		 * a response to our window probe. And that
15720 		 * means the rwnd sent must match the current
15721 		 * snd_wnd. If it does not, then we got a
15722 		 * window update ack instead. For keepalive
15723 		 * we allow the answer no matter what the window.
15724 		 *
15725 		 * Note that if the probe_not_answered is set then
15726 		 * the forced_ack_ts is the oldest one i.e. the first
15727 		 * probe sent that might have been lost. This assures
15728 		 * us that if we do calculate an RTT it is longer not
15729 		 * some short thing.
15730 		 */
15731 		if (rack->rc_in_persist)
15732 			counter_u64_add(rack_persists_acks, 1);
15733 		us_rtt = us_cts - rack->r_ctl.forced_ack_ts;
15734 		if (us_rtt == 0)
15735 			us_rtt = 1;
15736 		if (rack->probe_not_answered == 0) {
15737 			rack_apply_updated_usrtt(rack, us_rtt, us_cts);
15738 			tcp_rack_xmit_timer(rack, us_rtt, 0, us_rtt, 3, NULL, 1);
15739 		} else {
15740 			/* We have a retransmitted probe here too */
15741 			if (rack_apply_rtt_with_reduced_conf) {
15742 				rack_apply_updated_usrtt(rack, us_rtt, us_cts);
15743 				tcp_rack_xmit_timer(rack, us_rtt, 0, us_rtt, 0, NULL, 1);
15744 			}
15745 		}
15746 	}
15747 }
15748 
15749 static int
15750 rack_do_compressed_ack_processing(struct tcpcb *tp, struct socket *so, struct mbuf *m, int nxt_pkt, struct timeval *tv)
15751 {
15752 	/*
15753 	 * Handle a "special" compressed ack mbuf. Each incoming
15754 	 * ack has only four possible dispositions:
15755 	 *
15756 	 * A) It moves the cum-ack forward
15757 	 * B) It is behind the cum-ack.
15758 	 * C) It is a window-update ack.
15759 	 * D) It is a dup-ack.
15760 	 *
15761 	 * Note that we can have between 1 -> TCP_COMP_ACK_ENTRIES
15762 	 * in the incoming mbuf. We also need to still pay attention
15763 	 * to nxt_pkt since there may be another packet after this
15764 	 * one.
15765 	 */
15766 #ifdef TCP_ACCOUNTING
15767 	uint64_t ts_val;
15768 	uint64_t rdstc;
15769 #endif
15770 	int segsiz;
15771 	struct timespec ts;
15772 	struct tcp_rack *rack;
15773 	struct tcp_ackent *ae;
15774 	uint32_t tiwin, ms_cts, cts, acked, acked_amount, high_seq, win_seq, the_win, win_upd_ack;
15775 	int cnt, i, did_out, ourfinisacked = 0;
15776 	struct tcpopt to_holder, *to = NULL;
15777 #ifdef TCP_ACCOUNTING
15778 	int win_up_req = 0;
15779 #endif
15780 	int nsegs = 0;
15781 	int under_pacing = 0;
15782 	int recovery = 0;
15783 #ifdef TCP_ACCOUNTING
15784 	sched_pin();
15785 #endif
15786 	rack = (struct tcp_rack *)tp->t_fb_ptr;
15787 	if (rack->gp_ready &&
15788 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT))
15789 		under_pacing = 1;
15790 
15791 	if (rack->r_state != tp->t_state)
15792 		rack_set_state(tp, rack);
15793 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
15794 	    (tp->t_flags & TF_GPUTINPROG)) {
15795 		/*
15796 		 * We have a goodput in progress
15797 		 * and we have entered a late state.
15798 		 * Do we have enough data in the sb
15799 		 * to handle the GPUT request?
15800 		 */
15801 		uint32_t bytes;
15802 
15803 		bytes = tp->gput_ack - tp->gput_seq;
15804 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
15805 			bytes += tp->gput_seq - tp->snd_una;
15806 		if (bytes > sbavail(&tptosocket(tp)->so_snd)) {
15807 			/*
15808 			 * There are not enough bytes in the socket
15809 			 * buffer that have been sent to cover this
15810 			 * measurement. Cancel it.
15811 			 */
15812 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
15813 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
15814 						   tp->gput_seq,
15815 						   0, 0, 18, __LINE__, NULL, 0);
15816 			tp->t_flags &= ~TF_GPUTINPROG;
15817 		}
15818 	}
15819 	to = &to_holder;
15820 	to->to_flags = 0;
15821 	KASSERT((m->m_len >= sizeof(struct tcp_ackent)),
15822 		("tp:%p m_cmpack:%p with invalid len:%u", tp, m, m->m_len));
15823 	cnt = m->m_len / sizeof(struct tcp_ackent);
15824 	counter_u64_add(rack_multi_single_eq, cnt);
15825 	high_seq = tp->snd_una;
15826 	the_win = tp->snd_wnd;
15827 	win_seq = tp->snd_wl1;
15828 	win_upd_ack = tp->snd_wl2;
15829 	cts = tcp_tv_to_usectick(tv);
15830 	ms_cts = tcp_tv_to_mssectick(tv);
15831 	rack->r_ctl.rc_rcvtime = cts;
15832 	segsiz = ctf_fixed_maxseg(tp);
15833 	if ((rack->rc_gp_dyn_mul) &&
15834 	    (rack->use_fixed_rate == 0) &&
15835 	    (rack->rc_always_pace)) {
15836 		/* Check in on probertt */
15837 		rack_check_probe_rtt(rack, cts);
15838 	}
15839 	for (i = 0; i < cnt; i++) {
15840 #ifdef TCP_ACCOUNTING
15841 		ts_val = get_cyclecount();
15842 #endif
15843 		rack_clear_rate_sample(rack);
15844 		ae = ((mtod(m, struct tcp_ackent *)) + i);
15845 		if (ae->flags & TH_FIN)
15846 			rack_log_pacing_delay_calc(rack,
15847 						   0,
15848 						   0,
15849 						   0,
15850 						   rack_get_gp_est(rack), /* delRate */
15851 						   rack_get_lt_bw(rack), /* rttProp */
15852 						   20, __LINE__, NULL, 0);
15853 		/* Setup the window */
15854 		tiwin = ae->win << tp->snd_scale;
15855 		if (tiwin > rack->r_ctl.rc_high_rwnd)
15856 			rack->r_ctl.rc_high_rwnd = tiwin;
15857 		/* figure out the type of ack */
15858 		if (SEQ_LT(ae->ack, high_seq)) {
15859 			/* Case B*/
15860 			ae->ack_val_set = ACK_BEHIND;
15861 		} else if (SEQ_GT(ae->ack, high_seq)) {
15862 			/* Case A */
15863 			ae->ack_val_set = ACK_CUMACK;
15864 		} else if ((tiwin == the_win) && (rack->rc_in_persist == 0)){
15865 			/* Case D */
15866 			ae->ack_val_set = ACK_DUPACK;
15867 		} else {
15868 			/* Case C */
15869 			ae->ack_val_set = ACK_RWND;
15870 		}
15871 		if (rack->sack_attack_disable > 0) {
15872 			rack_log_type_bbrsnd(rack, 0, 0, cts, tv, __LINE__);
15873 			rack->r_ctl.ack_during_sd++;
15874 		}
15875 		rack_log_input_packet(tp, rack, ae, ae->ack_val_set, high_seq);
15876 		/* Validate timestamp */
15877 		if (ae->flags & HAS_TSTMP) {
15878 			/* Setup for a timestamp */
15879 			to->to_flags = TOF_TS;
15880 			ae->ts_echo -= tp->ts_offset;
15881 			to->to_tsecr = ae->ts_echo;
15882 			to->to_tsval = ae->ts_value;
15883 			/*
15884 			 * If echoed timestamp is later than the current time, fall back to
15885 			 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
15886 			 * were used when this connection was established.
15887 			 */
15888 			if (TSTMP_GT(ae->ts_echo, ms_cts))
15889 				to->to_tsecr = 0;
15890 			if (tp->ts_recent &&
15891 			    TSTMP_LT(ae->ts_value, tp->ts_recent)) {
15892 				if (ctf_ts_check_ac(tp, (ae->flags & 0xff))) {
15893 #ifdef TCP_ACCOUNTING
15894 					rdstc = get_cyclecount();
15895 					if (rdstc > ts_val) {
15896 						if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
15897 							tp->tcp_proc_time[ae->ack_val_set] += (rdstc - ts_val);
15898 						}
15899 					}
15900 #endif
15901 					continue;
15902 				}
15903 			}
15904 			if (SEQ_LEQ(ae->seq, tp->last_ack_sent) &&
15905 			    SEQ_LEQ(tp->last_ack_sent, ae->seq)) {
15906 				tp->ts_recent_age = tcp_ts_getticks();
15907 				tp->ts_recent = ae->ts_value;
15908 			}
15909 		} else {
15910 			/* Setup for a no options */
15911 			to->to_flags = 0;
15912 		}
15913 		/* Update the rcv time and perform idle reduction possibly */
15914 		if  (tp->t_idle_reduce &&
15915 		     (tp->snd_max == tp->snd_una) &&
15916 		     (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
15917 			counter_u64_add(rack_input_idle_reduces, 1);
15918 			rack_cc_after_idle(rack, tp);
15919 		}
15920 		tp->t_rcvtime = ticks;
15921 		/* Now what about ECN of a chain of pure ACKs? */
15922 		if (tcp_ecn_input_segment(tp, ae->flags, 0,
15923 			tcp_packets_this_ack(tp, ae->ack),
15924 			ae->codepoint))
15925 			rack_cong_signal(tp, CC_ECN, ae->ack, __LINE__);
15926 #ifdef TCP_ACCOUNTING
15927 		/* Count for the specific type of ack in */
15928 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
15929 			tp->tcp_cnt_counters[ae->ack_val_set]++;
15930 		}
15931 #endif
15932 		/*
15933 		 * Note how we could move up these in the determination
15934 		 * above, but we don't so that way the timestamp checks (and ECN)
15935 		 * is done first before we do any processing on the ACK.
15936 		 * The non-compressed path through the code has this
15937 		 * weakness (noted by @jtl) that it actually does some
15938 		 * processing before verifying the timestamp information.
15939 		 * We don't take that path here which is why we set
15940 		 * the ack_val_set first, do the timestamp and ecn
15941 		 * processing, and then look at what we have setup.
15942 		 */
15943 		if (ae->ack_val_set == ACK_BEHIND) {
15944 			/*
15945 			 * Case B flag reordering, if window is not closed
15946 			 * or it could be a keep-alive or persists
15947 			 */
15948 			if (SEQ_LT(ae->ack, tp->snd_una) && (sbspace(&so->so_rcv) > segsiz)) {
15949 				rack->r_ctl.rc_reorder_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
15950 				if (rack->r_ctl.rc_reorder_ts == 0)
15951 					rack->r_ctl.rc_reorder_ts = 1;
15952 			}
15953 		} else if (ae->ack_val_set == ACK_DUPACK) {
15954 			/* Case D */
15955 			rack_strike_dupack(rack);
15956 		} else if (ae->ack_val_set == ACK_RWND) {
15957 			/* Case C */
15958 			if ((ae->flags & TSTMP_LRO) || (ae->flags & TSTMP_HDWR)) {
15959 				ts.tv_sec = ae->timestamp / 1000000000;
15960 				ts.tv_nsec = ae->timestamp % 1000000000;
15961 				rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
15962 				rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
15963 			} else {
15964 				rack->r_ctl.act_rcv_time = *tv;
15965 			}
15966 			if (rack->forced_ack) {
15967 				rack_handle_probe_response(rack, tiwin,
15968 							   tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time));
15969 			}
15970 #ifdef TCP_ACCOUNTING
15971 			win_up_req = 1;
15972 #endif
15973 			win_upd_ack = ae->ack;
15974 			win_seq = ae->seq;
15975 			the_win = tiwin;
15976 			rack_do_win_updates(tp, rack, the_win, win_seq, win_upd_ack, cts);
15977 		} else {
15978 			/* Case A */
15979 			if (SEQ_GT(ae->ack, tp->snd_max)) {
15980 				/*
15981 				 * We just send an ack since the incoming
15982 				 * ack is beyond the largest seq we sent.
15983 				 */
15984 				if ((tp->t_flags & TF_ACKNOW) == 0) {
15985 					ctf_ack_war_checks(tp, &rack->r_ctl.challenge_ack_ts, &rack->r_ctl.challenge_ack_cnt);
15986 					if (tp->t_flags && TF_ACKNOW)
15987 						rack->r_wanted_output = 1;
15988 				}
15989 			} else {
15990 				nsegs++;
15991 				/* If the window changed setup to update */
15992 				if (tiwin != tp->snd_wnd) {
15993 					win_upd_ack = ae->ack;
15994 					win_seq = ae->seq;
15995 					the_win = tiwin;
15996 					rack_do_win_updates(tp, rack, the_win, win_seq, win_upd_ack, cts);
15997 				}
15998 #ifdef TCP_ACCOUNTING
15999 				/* Account for the acks */
16000 				if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16001 					tp->tcp_cnt_counters[CNT_OF_ACKS_IN] += (((ae->ack - high_seq) + segsiz - 1) / segsiz);
16002 				}
16003 #endif
16004 				high_seq = ae->ack;
16005 				if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp))
16006 					rack_log_hystart_event(rack, high_seq, 8);
16007 				/* Setup our act_rcv_time */
16008 				if ((ae->flags & TSTMP_LRO) || (ae->flags & TSTMP_HDWR)) {
16009 					ts.tv_sec = ae->timestamp / 1000000000;
16010 					ts.tv_nsec = ae->timestamp % 1000000000;
16011 					rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
16012 					rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
16013 				} else {
16014 					rack->r_ctl.act_rcv_time = *tv;
16015 				}
16016 				rack_process_to_cumack(tp, rack, ae->ack, cts, to,
16017 						       tcp_tv_to_lusectick(&rack->r_ctl.act_rcv_time));
16018 #ifdef TCP_REQUEST_TRK
16019 				rack_http_check_for_comp(rack, high_seq);
16020 #endif
16021 				if (rack->rc_dsack_round_seen) {
16022 					/* Is the dsack round over? */
16023 					if (SEQ_GEQ(ae->ack, rack->r_ctl.dsack_round_end)) {
16024 						/* Yes it is */
16025 						rack->rc_dsack_round_seen = 0;
16026 						rack_log_dsack_event(rack, 3, __LINE__, 0, 0);
16027 					}
16028 				}
16029 			}
16030 		}
16031 		/* And lets be sure to commit the rtt measurements for this ack */
16032 		tcp_rack_xmit_timer_commit(rack, tp);
16033 #ifdef TCP_ACCOUNTING
16034 		rdstc = get_cyclecount();
16035 		if (rdstc > ts_val) {
16036 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16037 				tp->tcp_proc_time[ae->ack_val_set] += (rdstc - ts_val);
16038 				if (ae->ack_val_set == ACK_CUMACK)
16039 					tp->tcp_proc_time[CYC_HANDLE_MAP] += (rdstc - ts_val);
16040 			}
16041 		}
16042 #endif
16043 	}
16044 #ifdef TCP_ACCOUNTING
16045 	ts_val = get_cyclecount();
16046 #endif
16047 	/* Tend to any collapsed window */
16048 	if (SEQ_GT(tp->snd_max, high_seq) && (tp->snd_wnd < (tp->snd_max - high_seq))) {
16049 		/* The peer collapsed the window */
16050 		rack_collapsed_window(rack, (tp->snd_max - high_seq), high_seq, __LINE__);
16051 	} else if (rack->rc_has_collapsed)
16052 		rack_un_collapse_window(rack, __LINE__);
16053 	if ((rack->r_collapse_point_valid) &&
16054 	    (SEQ_GT(high_seq, rack->r_ctl.high_collapse_point)))
16055 		rack->r_collapse_point_valid = 0;
16056 	acked_amount = acked = (high_seq - tp->snd_una);
16057 	if (acked) {
16058 		/*
16059 		 * The draft (v3) calls for us to use SEQ_GEQ, but that
16060 		 * causes issues when we are just going app limited. Lets
16061 		 * instead use SEQ_GT <or> where its equal but more data
16062 		 * is outstanding.
16063 		 *
16064 		 * Also make sure we are on the last ack of a series. We
16065 		 * have to have all the ack's processed in queue to know
16066 		 * if there is something left outstanding.
16067 		 *
16068 		 */
16069 		if (SEQ_GEQ(high_seq, rack->r_ctl.roundends) &&
16070 		    (rack->rc_new_rnd_needed == 0) &&
16071 		    (nxt_pkt == 0)) {
16072 			rack_log_hystart_event(rack, high_seq, 21);
16073 			rack->r_ctl.current_round++;
16074 			/* Force the next send to setup the next round */
16075 			rack->rc_new_rnd_needed = 1;
16076 			if (CC_ALGO(tp)->newround != NULL) {
16077 				CC_ALGO(tp)->newround(&tp->t_ccv, rack->r_ctl.current_round);
16078 			}
16079 		}
16080 		/*
16081 		 * Clear the probe not answered flag
16082 		 * since cum-ack moved forward.
16083 		 */
16084 		rack->probe_not_answered = 0;
16085 		if (rack->sack_attack_disable == 0)
16086 			rack_do_decay(rack);
16087 		if (acked >= segsiz) {
16088 			/*
16089 			 * You only get credit for
16090 			 * MSS and greater (and you get extra
16091 			 * credit for larger cum-ack moves).
16092 			 */
16093 			int ac;
16094 
16095 			ac = acked / segsiz;
16096 			rack->r_ctl.ack_count += ac;
16097 			counter_u64_add(rack_ack_total, ac);
16098 		}
16099 		if (rack->r_ctl.ack_count > 0xfff00000) {
16100 			/*
16101 			 * reduce the number to keep us under
16102 			 * a uint32_t.
16103 			 */
16104 			rack->r_ctl.ack_count /= 2;
16105 			rack->r_ctl.sack_count /= 2;
16106 		}
16107 		if (tp->t_flags & TF_NEEDSYN) {
16108 			/*
16109 			 * T/TCP: Connection was half-synchronized, and our SYN has
16110 			 * been ACK'd (so connection is now fully synchronized).  Go
16111 			 * to non-starred state, increment snd_una for ACK of SYN,
16112 			 * and check if we can do window scaling.
16113 			 */
16114 			tp->t_flags &= ~TF_NEEDSYN;
16115 			tp->snd_una++;
16116 			acked_amount = acked = (high_seq - tp->snd_una);
16117 		}
16118 		if (acked > sbavail(&so->so_snd))
16119 			acked_amount = sbavail(&so->so_snd);
16120 #ifdef TCP_SAD_DETECTION
16121 		/*
16122 		 * We only care on a cum-ack move if we are in a sack-disabled
16123 		 * state. We have already added in to the ack_count, and we never
16124 		 * would disable on a cum-ack move, so we only care to do the
16125 		 * detection if it may "undo" it, i.e. we were in disabled already.
16126 		 */
16127 		if (rack->sack_attack_disable)
16128 			rack_do_detection(tp, rack, acked_amount, segsiz);
16129 #endif
16130 		if (IN_FASTRECOVERY(tp->t_flags) &&
16131 		    (rack->rack_no_prr == 0))
16132 			rack_update_prr(tp, rack, acked_amount, high_seq);
16133 		if (IN_RECOVERY(tp->t_flags)) {
16134 			if (SEQ_LT(high_seq, tp->snd_recover) &&
16135 			    (SEQ_LT(high_seq, tp->snd_max))) {
16136 				tcp_rack_partialack(tp);
16137 			} else {
16138 				rack_post_recovery(tp, high_seq);
16139 				recovery = 1;
16140 			}
16141 		}
16142 		/* Handle the rack-log-ack part (sendmap) */
16143 		if ((sbused(&so->so_snd) == 0) &&
16144 		    (acked > acked_amount) &&
16145 		    (tp->t_state >= TCPS_FIN_WAIT_1) &&
16146 		    (tp->t_flags & TF_SENTFIN)) {
16147 			/*
16148 			 * We must be sure our fin
16149 			 * was sent and acked (we can be
16150 			 * in FIN_WAIT_1 without having
16151 			 * sent the fin).
16152 			 */
16153 			ourfinisacked = 1;
16154 			/*
16155 			 * Lets make sure snd_una is updated
16156 			 * since most likely acked_amount = 0 (it
16157 			 * should be).
16158 			 */
16159 			tp->snd_una = high_seq;
16160 		}
16161 		/* Did we make a RTO error? */
16162 		if ((tp->t_flags & TF_PREVVALID) &&
16163 		    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
16164 			tp->t_flags &= ~TF_PREVVALID;
16165 			if (tp->t_rxtshift == 1 &&
16166 			    (int)(ticks - tp->t_badrxtwin) < 0)
16167 				rack_cong_signal(tp, CC_RTO_ERR, high_seq, __LINE__);
16168 		}
16169 		/* Handle the data in the socket buffer */
16170 		KMOD_TCPSTAT_ADD(tcps_rcvackpack, 1);
16171 		KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
16172 		if (acked_amount > 0) {
16173 			struct mbuf *mfree;
16174 
16175 			rack_ack_received(tp, rack, high_seq, nsegs, CC_ACK, recovery);
16176 			SOCKBUF_LOCK(&so->so_snd);
16177 			mfree = sbcut_locked(&so->so_snd, acked_amount);
16178 			tp->snd_una = high_seq;
16179 			/* Note we want to hold the sb lock through the sendmap adjust */
16180 			rack_adjust_sendmap_head(rack, &so->so_snd);
16181 			/* Wake up the socket if we have room to write more */
16182 			rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
16183 			sowwakeup_locked(so);
16184 			if ((recovery == 1) &&
16185 			    (rack->excess_rxt_on) &&
16186 			    (rack->r_cwnd_was_clamped == 0)) {
16187 				do_rack_excess_rxt(tp, rack);
16188 			} else if (rack->r_cwnd_was_clamped)
16189 				do_rack_check_for_unclamp(tp, rack);
16190 			m_freem(mfree);
16191 		}
16192 		/* update progress */
16193 		tp->t_acktime = ticks;
16194 		rack_log_progress_event(rack, tp, tp->t_acktime,
16195 					PROGRESS_UPDATE, __LINE__);
16196 		/* Clear out shifts and such */
16197 		tp->t_rxtshift = 0;
16198 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
16199 				   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
16200 		rack->rc_tlp_in_progress = 0;
16201 		rack->r_ctl.rc_tlp_cnt_out = 0;
16202 		/* Send recover and snd_nxt must be dragged along */
16203 		if (SEQ_GT(tp->snd_una, tp->snd_recover))
16204 			tp->snd_recover = tp->snd_una;
16205 		if (SEQ_LT(tp->snd_nxt, tp->snd_una))
16206 			tp->snd_nxt = tp->snd_una;
16207 		/*
16208 		 * If the RXT timer is running we want to
16209 		 * stop it, so we can restart a TLP (or new RXT).
16210 		 */
16211 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
16212 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
16213 		tp->snd_wl2 = high_seq;
16214 		tp->t_dupacks = 0;
16215 		if (under_pacing &&
16216 		    (rack->use_fixed_rate == 0) &&
16217 		    (rack->in_probe_rtt == 0) &&
16218 		    rack->rc_gp_dyn_mul &&
16219 		    rack->rc_always_pace) {
16220 			/* Check if we are dragging bottom */
16221 			rack_check_bottom_drag(tp, rack, so);
16222 		}
16223 		if (tp->snd_una == tp->snd_max) {
16224 			tp->t_flags &= ~TF_PREVVALID;
16225 			rack->r_ctl.retran_during_recovery = 0;
16226 			rack->rc_suspicious = 0;
16227 			rack->r_ctl.dsack_byte_cnt = 0;
16228 			rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
16229 			if (rack->r_ctl.rc_went_idle_time == 0)
16230 				rack->r_ctl.rc_went_idle_time = 1;
16231 			rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
16232 			if (sbavail(&tptosocket(tp)->so_snd) == 0)
16233 				tp->t_acktime = 0;
16234 			/* Set so we might enter persists... */
16235 			rack->r_wanted_output = 1;
16236 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
16237 			sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
16238 			if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
16239 			    (sbavail(&so->so_snd) == 0) &&
16240 			    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
16241 				/*
16242 				 * The socket was gone and the
16243 				 * peer sent data (not now in the past), time to
16244 				 * reset him.
16245 				 */
16246 				rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
16247 				/* tcp_close will kill the inp pre-log the Reset */
16248 				tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
16249 #ifdef TCP_ACCOUNTING
16250 				rdstc = get_cyclecount();
16251 				if (rdstc > ts_val) {
16252 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16253 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16254 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16255 					}
16256 				}
16257 #endif
16258 				m_freem(m);
16259 				tp = tcp_close(tp);
16260 				if (tp == NULL) {
16261 #ifdef TCP_ACCOUNTING
16262 					sched_unpin();
16263 #endif
16264 					return (1);
16265 				}
16266 				/*
16267 				 * We would normally do drop-with-reset which would
16268 				 * send back a reset. We can't since we don't have
16269 				 * all the needed bits. Instead lets arrange for
16270 				 * a call to tcp_output(). That way since we
16271 				 * are in the closed state we will generate a reset.
16272 				 *
16273 				 * Note if tcp_accounting is on we don't unpin since
16274 				 * we do that after the goto label.
16275 				 */
16276 				goto send_out_a_rst;
16277 			}
16278 			if ((sbused(&so->so_snd) == 0) &&
16279 			    (tp->t_state >= TCPS_FIN_WAIT_1) &&
16280 			    (tp->t_flags & TF_SENTFIN)) {
16281 				/*
16282 				 * If we can't receive any more data, then closing user can
16283 				 * proceed. Starting the timer is contrary to the
16284 				 * specification, but if we don't get a FIN we'll hang
16285 				 * forever.
16286 				 *
16287 				 */
16288 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
16289 					soisdisconnected(so);
16290 					tcp_timer_activate(tp, TT_2MSL,
16291 							   (tcp_fast_finwait2_recycle ?
16292 							    tcp_finwait2_timeout :
16293 							    TP_MAXIDLE(tp)));
16294 				}
16295 				if (ourfinisacked == 0) {
16296 					/*
16297 					 * We don't change to fin-wait-2 if we have our fin acked
16298 					 * which means we are probably in TCPS_CLOSING.
16299 					 */
16300 					tcp_state_change(tp, TCPS_FIN_WAIT_2);
16301 				}
16302 			}
16303 		}
16304 		/* Wake up the socket if we have room to write more */
16305 		if (sbavail(&so->so_snd)) {
16306 			rack->r_wanted_output = 1;
16307 			if (ctf_progress_timeout_check(tp, true)) {
16308 				rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
16309 							tp, tick, PROGRESS_DROP, __LINE__);
16310 				/*
16311 				 * We cheat here and don't send a RST, we should send one
16312 				 * when the pacer drops the connection.
16313 				 */
16314 #ifdef TCP_ACCOUNTING
16315 				rdstc = get_cyclecount();
16316 				if (rdstc > ts_val) {
16317 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16318 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16319 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16320 					}
16321 				}
16322 				sched_unpin();
16323 #endif
16324 				(void)tcp_drop(tp, ETIMEDOUT);
16325 				m_freem(m);
16326 				return (1);
16327 			}
16328 		}
16329 		if (ourfinisacked) {
16330 			switch(tp->t_state) {
16331 			case TCPS_CLOSING:
16332 #ifdef TCP_ACCOUNTING
16333 				rdstc = get_cyclecount();
16334 				if (rdstc > ts_val) {
16335 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16336 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16337 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16338 					}
16339 				}
16340 				sched_unpin();
16341 #endif
16342 				tcp_twstart(tp);
16343 				m_freem(m);
16344 				return (1);
16345 				break;
16346 			case TCPS_LAST_ACK:
16347 #ifdef TCP_ACCOUNTING
16348 				rdstc = get_cyclecount();
16349 				if (rdstc > ts_val) {
16350 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16351 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16352 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16353 					}
16354 				}
16355 				sched_unpin();
16356 #endif
16357 				tp = tcp_close(tp);
16358 				ctf_do_drop(m, tp);
16359 				return (1);
16360 				break;
16361 			case TCPS_FIN_WAIT_1:
16362 #ifdef TCP_ACCOUNTING
16363 				rdstc = get_cyclecount();
16364 				if (rdstc > ts_val) {
16365 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16366 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16367 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16368 					}
16369 				}
16370 #endif
16371 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
16372 					soisdisconnected(so);
16373 					tcp_timer_activate(tp, TT_2MSL,
16374 							   (tcp_fast_finwait2_recycle ?
16375 							    tcp_finwait2_timeout :
16376 							    TP_MAXIDLE(tp)));
16377 				}
16378 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
16379 				break;
16380 			default:
16381 				break;
16382 			}
16383 		}
16384 		if (rack->r_fast_output) {
16385 			/*
16386 			 * We re doing fast output.. can we expand that?
16387 			 */
16388 			rack_gain_for_fastoutput(rack, tp, so, acked_amount);
16389 		}
16390 #ifdef TCP_ACCOUNTING
16391 		rdstc = get_cyclecount();
16392 		if (rdstc > ts_val) {
16393 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16394 				tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16395 				tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16396 			}
16397 		}
16398 
16399 	} else if (win_up_req) {
16400 		rdstc = get_cyclecount();
16401 		if (rdstc > ts_val) {
16402 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16403 				tp->tcp_proc_time[ACK_RWND] += (rdstc - ts_val);
16404 			}
16405 		}
16406 #endif
16407 	}
16408 	/* Now is there a next packet, if so we are done */
16409 	m_freem(m);
16410 	did_out = 0;
16411 	if (nxt_pkt) {
16412 #ifdef TCP_ACCOUNTING
16413 		sched_unpin();
16414 #endif
16415 		rack_log_doseg_done(rack, cts, nxt_pkt, did_out, 5, nsegs);
16416 		return (0);
16417 	}
16418 	rack_handle_might_revert(tp, rack);
16419 	ctf_calc_rwin(so, tp);
16420 	if ((rack->r_wanted_output != 0) || (rack->r_fast_output != 0)) {
16421 	send_out_a_rst:
16422 		if (tcp_output(tp) < 0) {
16423 #ifdef TCP_ACCOUNTING
16424 			sched_unpin();
16425 #endif
16426 			return (1);
16427 		}
16428 		did_out = 1;
16429 	}
16430 	rack_free_trim(rack);
16431 #ifdef TCP_ACCOUNTING
16432 	sched_unpin();
16433 #endif
16434 	rack_timer_audit(tp, rack, &so->so_snd);
16435 	rack_log_doseg_done(rack, cts, nxt_pkt, did_out, 6, nsegs);
16436 	return (0);
16437 }
16438 
16439 #define	TCP_LRO_TS_OPTION \
16440     ntohl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | \
16441 	  (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP)
16442 
16443 static int
16444 rack_do_segment_nounlock(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
16445     int32_t drop_hdrlen, int32_t tlen, uint8_t iptos, int32_t nxt_pkt,
16446     struct timeval *tv)
16447 {
16448 	struct inpcb *inp = tptoinpcb(tp);
16449 	struct socket *so = tptosocket(tp);
16450 #ifdef TCP_ACCOUNTING
16451 	uint64_t ts_val;
16452 #endif
16453 	int32_t thflags, retval, did_out = 0;
16454 	int32_t way_out = 0;
16455 	/*
16456 	 * cts - is the current time from tv (caller gets ts) in microseconds.
16457 	 * ms_cts - is the current time from tv in milliseconds.
16458 	 * us_cts - is the time that LRO or hardware actually got the packet in microseconds.
16459 	 */
16460 	uint32_t cts, us_cts, ms_cts;
16461 	uint32_t tiwin, high_seq;
16462 	struct timespec ts;
16463 	struct tcpopt to;
16464 	struct tcp_rack *rack;
16465 	struct rack_sendmap *rsm;
16466 	int32_t prev_state = 0;
16467 	int no_output = 0;
16468 	int slot_remaining = 0;
16469 #ifdef TCP_ACCOUNTING
16470 	int ack_val_set = 0xf;
16471 #endif
16472 	int nsegs;
16473 
16474 	NET_EPOCH_ASSERT();
16475 	INP_WLOCK_ASSERT(inp);
16476 
16477 	/*
16478 	 * tv passed from common code is from either M_TSTMP_LRO or
16479 	 * tcp_get_usecs() if no LRO m_pkthdr timestamp is present.
16480 	 */
16481 	rack = (struct tcp_rack *)tp->t_fb_ptr;
16482 	if (rack->rack_deferred_inited == 0) {
16483 		/*
16484 		 * If we are the connecting socket we will
16485 		 * hit rack_init() when no sequence numbers
16486 		 * are setup. This makes it so we must defer
16487 		 * some initialization. Call that now.
16488 		 */
16489 		rack_deferred_init(tp, rack);
16490 	}
16491 	/*
16492 	 * Check to see if we need to skip any output plans. This
16493 	 * can happen in the non-LRO path where we are pacing and
16494 	 * must process the ack coming in but need to defer sending
16495 	 * anything becase a pacing timer is running.
16496 	 */
16497 	us_cts = tcp_tv_to_usectick(tv);
16498 	if ((rack->rc_always_pace == 1) &&
16499 	    (rack->rc_ack_can_sendout_data == 0) &&
16500 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
16501 	    (TSTMP_LT(us_cts, rack->r_ctl.rc_last_output_to))) {
16502 		/*
16503 		 * Ok conditions are right for queuing the packets
16504 		 * but we do have to check the flags in the inp, it
16505 		 * could be, if a sack is present, we want to be awoken and
16506 		 * so should process the packets.
16507 		 */
16508 		slot_remaining = rack->r_ctl.rc_last_output_to - us_cts;
16509 		if (rack->rc_inp->inp_flags2 & INP_DONT_SACK_QUEUE) {
16510 			no_output = 1;
16511 		} else {
16512 			/*
16513 			 * If there is no options, or just a
16514 			 * timestamp option, we will want to queue
16515 			 * the packets. This is the same that LRO does
16516 			 * and will need to change with accurate ECN.
16517 			 */
16518 			uint32_t *ts_ptr;
16519 			int optlen;
16520 
16521 			optlen = (th->th_off << 2) - sizeof(struct tcphdr);
16522 			ts_ptr = (uint32_t *)(th + 1);
16523 			if ((optlen == 0) ||
16524 			    ((optlen == TCPOLEN_TSTAMP_APPA) &&
16525 			     (*ts_ptr == TCP_LRO_TS_OPTION)))
16526 				no_output = 1;
16527 		}
16528 	}
16529 	if (m->m_flags & M_ACKCMP) {
16530 		/*
16531 		 * All compressed ack's are ack's by definition so
16532 		 * remove any ack required flag and then do the processing.
16533 		 */
16534 		rack->rc_ack_required = 0;
16535 		return (rack_do_compressed_ack_processing(tp, so, m, nxt_pkt, tv));
16536 	}
16537 	thflags = tcp_get_flags(th);
16538 	/*
16539 	 * If there is a RST or FIN lets dump out the bw
16540 	 * with a FIN the connection may go on but we
16541 	 * may not.
16542 	 */
16543 	if ((thflags & TH_FIN) || (thflags & TH_RST))
16544 		rack_log_pacing_delay_calc(rack,
16545 					   rack->r_ctl.gp_bw,
16546 					   0,
16547 					   0,
16548 					   rack_get_gp_est(rack), /* delRate */
16549 					   rack_get_lt_bw(rack), /* rttProp */
16550 					   20, __LINE__, NULL, 0);
16551 	if (m->m_flags & M_ACKCMP) {
16552 		panic("Impossible reach m has ackcmp? m:%p tp:%p", m, tp);
16553 	}
16554 	cts = tcp_tv_to_usectick(tv);
16555 	ms_cts =  tcp_tv_to_mssectick(tv);
16556 	nsegs = m->m_pkthdr.lro_nsegs;
16557 	counter_u64_add(rack_proc_non_comp_ack, 1);
16558 #ifdef TCP_ACCOUNTING
16559 	sched_pin();
16560 	if (thflags & TH_ACK)
16561 		ts_val = get_cyclecount();
16562 #endif
16563 	if ((m->m_flags & M_TSTMP) ||
16564 	    (m->m_flags & M_TSTMP_LRO)) {
16565 		mbuf_tstmp2timespec(m, &ts);
16566 		rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
16567 		rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
16568 	} else
16569 		rack->r_ctl.act_rcv_time = *tv;
16570 	kern_prefetch(rack, &prev_state);
16571 	prev_state = 0;
16572 	/*
16573 	 * Unscale the window into a 32-bit value. For the SYN_SENT state
16574 	 * the scale is zero.
16575 	 */
16576 	tiwin = th->th_win << tp->snd_scale;
16577 #ifdef TCP_ACCOUNTING
16578 	if (thflags & TH_ACK) {
16579 		/*
16580 		 * We have a tradeoff here. We can either do what we are
16581 		 * doing i.e. pinning to this CPU and then doing the accounting
16582 		 * <or> we could do a critical enter, setup the rdtsc and cpu
16583 		 * as in below, and then validate we are on the same CPU on
16584 		 * exit. I have choosen to not do the critical enter since
16585 		 * that often will gain you a context switch, and instead lock
16586 		 * us (line above this if) to the same CPU with sched_pin(). This
16587 		 * means we may be context switched out for a higher priority
16588 		 * interupt but we won't be moved to another CPU.
16589 		 *
16590 		 * If this occurs (which it won't very often since we most likely
16591 		 * are running this code in interupt context and only a higher
16592 		 * priority will bump us ... clock?) we will falsely add in
16593 		 * to the time the interupt processing time plus the ack processing
16594 		 * time. This is ok since its a rare event.
16595 		 */
16596 		ack_val_set = tcp_do_ack_accounting(tp, th, &to, tiwin,
16597 						    ctf_fixed_maxseg(tp));
16598 	}
16599 #endif
16600 	/*
16601 	 * Parse options on any incoming segment.
16602 	 */
16603 	memset(&to, 0, sizeof(to));
16604 	tcp_dooptions(&to, (u_char *)(th + 1),
16605 	    (th->th_off << 2) - sizeof(struct tcphdr),
16606 	    (thflags & TH_SYN) ? TO_SYN : 0);
16607 	KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN",
16608 	    __func__));
16609 	KASSERT(tp->t_state != TCPS_TIME_WAIT, ("%s: TCPS_TIME_WAIT",
16610 	    __func__));
16611 
16612 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
16613 	    (tp->t_flags & TF_GPUTINPROG)) {
16614 		/*
16615 		 * We have a goodput in progress
16616 		 * and we have entered a late state.
16617 		 * Do we have enough data in the sb
16618 		 * to handle the GPUT request?
16619 		 */
16620 		uint32_t bytes;
16621 
16622 		bytes = tp->gput_ack - tp->gput_seq;
16623 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
16624 			bytes += tp->gput_seq - tp->snd_una;
16625 		if (bytes > sbavail(&tptosocket(tp)->so_snd)) {
16626 			/*
16627 			 * There are not enough bytes in the socket
16628 			 * buffer that have been sent to cover this
16629 			 * measurement. Cancel it.
16630 			 */
16631 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
16632 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
16633 						   tp->gput_seq,
16634 						   0, 0, 18, __LINE__, NULL, 0);
16635 			tp->t_flags &= ~TF_GPUTINPROG;
16636 		}
16637 	}
16638 	high_seq = th->th_ack;
16639 	if (tcp_bblogging_on(rack->rc_tp)) {
16640 		union tcp_log_stackspecific log;
16641 		struct timeval ltv;
16642 #ifdef TCP_REQUEST_TRK
16643 		struct http_sendfile_track *http_req;
16644 
16645 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
16646 			http_req = tcp_http_find_req_for_seq(tp, (th->th_ack-1));
16647 		} else {
16648 			http_req = tcp_http_find_req_for_seq(tp, th->th_ack);
16649 		}
16650 #endif
16651 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
16652 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
16653 		if (rack->rack_no_prr == 0)
16654 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
16655 		else
16656 			log.u_bbr.flex1 = 0;
16657 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
16658 		log.u_bbr.use_lt_bw <<= 1;
16659 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
16660 		log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
16661 		log.u_bbr.bbr_state = rack->rc_free_cnt;
16662 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
16663 		log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
16664 		log.u_bbr.flex3 = m->m_flags;
16665 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
16666 		log.u_bbr.lost = thflags;
16667 		log.u_bbr.pacing_gain = 0x1;
16668 #ifdef TCP_ACCOUNTING
16669 		log.u_bbr.cwnd_gain = ack_val_set;
16670 #endif
16671 		log.u_bbr.flex7 = 2;
16672 		if (m->m_flags & M_TSTMP) {
16673 			/* Record the hardware timestamp if present */
16674 			mbuf_tstmp2timespec(m, &ts);
16675 			ltv.tv_sec = ts.tv_sec;
16676 			ltv.tv_usec = ts.tv_nsec / 1000;
16677 			log.u_bbr.lt_epoch = tcp_tv_to_usectick(&ltv);
16678 		} else if (m->m_flags & M_TSTMP_LRO) {
16679 			/* Record the LRO the arrival timestamp */
16680 			mbuf_tstmp2timespec(m, &ts);
16681 			ltv.tv_sec = ts.tv_sec;
16682 			ltv.tv_usec = ts.tv_nsec / 1000;
16683 			log.u_bbr.flex5 = tcp_tv_to_usectick(&ltv);
16684 		}
16685 		log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
16686 		/* Log the rcv time */
16687 		log.u_bbr.delRate = m->m_pkthdr.rcv_tstmp;
16688 #ifdef TCP_REQUEST_TRK
16689 		log.u_bbr.applimited = tp->t_http_closed;
16690 		log.u_bbr.applimited <<= 8;
16691 		log.u_bbr.applimited |= tp->t_http_open;
16692 		log.u_bbr.applimited <<= 8;
16693 		log.u_bbr.applimited |= tp->t_http_req;
16694 		if (http_req) {
16695 			/* Copy out any client req info */
16696 			/* seconds */
16697 			log.u_bbr.pkt_epoch = (http_req->localtime / HPTS_USEC_IN_SEC);
16698 			/* useconds */
16699 			log.u_bbr.delivered = (http_req->localtime % HPTS_USEC_IN_SEC);
16700 			log.u_bbr.rttProp = http_req->timestamp;
16701 			log.u_bbr.cur_del_rate = http_req->start;
16702 			if (http_req->flags & TCP_HTTP_TRACK_FLG_OPEN) {
16703 				log.u_bbr.flex8 |= 1;
16704 			} else {
16705 				log.u_bbr.flex8 |= 2;
16706 				log.u_bbr.bw_inuse = http_req->end;
16707 			}
16708 			log.u_bbr.flex6 = http_req->start_seq;
16709 			if (http_req->flags & TCP_HTTP_TRACK_FLG_COMP) {
16710 				log.u_bbr.flex8 |= 4;
16711 				log.u_bbr.epoch = http_req->end_seq;
16712 			}
16713 		}
16714 #endif
16715 		TCP_LOG_EVENTP(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_IN, 0,
16716 		    tlen, &log, true, &ltv);
16717 	}
16718 	/* Remove ack required flag if set, we have one  */
16719 	if (thflags & TH_ACK)
16720 		rack->rc_ack_required = 0;
16721 	if (rack->sack_attack_disable > 0) {
16722 		rack->r_ctl.ack_during_sd++;
16723 		rack_log_type_bbrsnd(rack, 0, 0, cts, tv, __LINE__);
16724 	}
16725 	if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) {
16726 		way_out = 4;
16727 		retval = 0;
16728 		m_freem(m);
16729 		goto done_with_input;
16730 	}
16731 	/*
16732 	 * If a segment with the ACK-bit set arrives in the SYN-SENT state
16733 	 * check SEQ.ACK first as described on page 66 of RFC 793, section 3.9.
16734 	 */
16735 	if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) &&
16736 	    (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) {
16737 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
16738 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
16739 #ifdef TCP_ACCOUNTING
16740 		sched_unpin();
16741 #endif
16742 		return (1);
16743 	}
16744 	/*
16745 	 * If timestamps were negotiated during SYN/ACK and a
16746 	 * segment without a timestamp is received, silently drop
16747 	 * the segment, unless it is a RST segment or missing timestamps are
16748 	 * tolerated.
16749 	 * See section 3.2 of RFC 7323.
16750 	 */
16751 	if ((tp->t_flags & TF_RCVD_TSTMP) && !(to.to_flags & TOF_TS) &&
16752 	    ((thflags & TH_RST) == 0) && (V_tcp_tolerate_missing_ts == 0)) {
16753 		way_out = 5;
16754 		retval = 0;
16755 		m_freem(m);
16756 		goto done_with_input;
16757 	}
16758 
16759 	/*
16760 	 * Segment received on connection. Reset idle time and keep-alive
16761 	 * timer. XXX: This should be done after segment validation to
16762 	 * ignore broken/spoofed segs.
16763 	 */
16764 	if  (tp->t_idle_reduce &&
16765 	     (tp->snd_max == tp->snd_una) &&
16766 	     (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
16767 		counter_u64_add(rack_input_idle_reduces, 1);
16768 		rack_cc_after_idle(rack, tp);
16769 	}
16770 	tp->t_rcvtime = ticks;
16771 #ifdef STATS
16772 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_FRWIN, tiwin);
16773 #endif
16774 	if (tiwin > rack->r_ctl.rc_high_rwnd)
16775 		rack->r_ctl.rc_high_rwnd = tiwin;
16776 	/*
16777 	 * TCP ECN processing. XXXJTL: If we ever use ECN, we need to move
16778 	 * this to occur after we've validated the segment.
16779 	 */
16780 	if (tcp_ecn_input_segment(tp, thflags, tlen,
16781 	    tcp_packets_this_ack(tp, th->th_ack),
16782 	    iptos))
16783 		rack_cong_signal(tp, CC_ECN, th->th_ack, __LINE__);
16784 
16785 	/*
16786 	 * If echoed timestamp is later than the current time, fall back to
16787 	 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
16788 	 * were used when this connection was established.
16789 	 */
16790 	if ((to.to_flags & TOF_TS) && (to.to_tsecr != 0)) {
16791 		to.to_tsecr -= tp->ts_offset;
16792 		if (TSTMP_GT(to.to_tsecr, ms_cts))
16793 			to.to_tsecr = 0;
16794 	}
16795 
16796 	/*
16797 	 * If its the first time in we need to take care of options and
16798 	 * verify we can do SACK for rack!
16799 	 */
16800 	if (rack->r_state == 0) {
16801 		/* Should be init'd by rack_init() */
16802 		KASSERT(rack->rc_inp != NULL,
16803 		    ("%s: rack->rc_inp unexpectedly NULL", __func__));
16804 		if (rack->rc_inp == NULL) {
16805 			rack->rc_inp = inp;
16806 		}
16807 
16808 		/*
16809 		 * Process options only when we get SYN/ACK back. The SYN
16810 		 * case for incoming connections is handled in tcp_syncache.
16811 		 * According to RFC1323 the window field in a SYN (i.e., a
16812 		 * <SYN> or <SYN,ACK>) segment itself is never scaled. XXX
16813 		 * this is traditional behavior, may need to be cleaned up.
16814 		 */
16815 		if (tp->t_state == TCPS_SYN_SENT && (thflags & TH_SYN)) {
16816 			/* Handle parallel SYN for ECN */
16817 			tcp_ecn_input_parallel_syn(tp, thflags, iptos);
16818 			if ((to.to_flags & TOF_SCALE) &&
16819 			    (tp->t_flags & TF_REQ_SCALE)) {
16820 				tp->t_flags |= TF_RCVD_SCALE;
16821 				tp->snd_scale = to.to_wscale;
16822 			} else
16823 				tp->t_flags &= ~TF_REQ_SCALE;
16824 			/*
16825 			 * Initial send window.  It will be updated with the
16826 			 * next incoming segment to the scaled value.
16827 			 */
16828 			tp->snd_wnd = th->th_win;
16829 			rack_validate_fo_sendwin_up(tp, rack);
16830 			if ((to.to_flags & TOF_TS) &&
16831 			    (tp->t_flags & TF_REQ_TSTMP)) {
16832 				tp->t_flags |= TF_RCVD_TSTMP;
16833 				tp->ts_recent = to.to_tsval;
16834 				tp->ts_recent_age = cts;
16835 			} else
16836 				tp->t_flags &= ~TF_REQ_TSTMP;
16837 			if (to.to_flags & TOF_MSS) {
16838 				tcp_mss(tp, to.to_mss);
16839 			}
16840 			if ((tp->t_flags & TF_SACK_PERMIT) &&
16841 			    (to.to_flags & TOF_SACKPERM) == 0)
16842 				tp->t_flags &= ~TF_SACK_PERMIT;
16843 			if (IS_FASTOPEN(tp->t_flags)) {
16844 				if (to.to_flags & TOF_FASTOPEN) {
16845 					uint16_t mss;
16846 
16847 					if (to.to_flags & TOF_MSS)
16848 						mss = to.to_mss;
16849 					else
16850 						if ((inp->inp_vflag & INP_IPV6) != 0)
16851 							mss = TCP6_MSS;
16852 						else
16853 							mss = TCP_MSS;
16854 					tcp_fastopen_update_cache(tp, mss,
16855 					    to.to_tfo_len, to.to_tfo_cookie);
16856 				} else
16857 					tcp_fastopen_disable_path(tp);
16858 			}
16859 		}
16860 		/*
16861 		 * At this point we are at the initial call. Here we decide
16862 		 * if we are doing RACK or not. We do this by seeing if
16863 		 * TF_SACK_PERMIT is set and the sack-not-required is clear.
16864 		 * The code now does do dup-ack counting so if you don't
16865 		 * switch back you won't get rack & TLP, but you will still
16866 		 * get this stack.
16867 		 */
16868 
16869 		if ((rack_sack_not_required == 0) &&
16870 		    ((tp->t_flags & TF_SACK_PERMIT) == 0)) {
16871 			tcp_switch_back_to_default(tp);
16872 			(*tp->t_fb->tfb_tcp_do_segment)(tp, m, th, drop_hdrlen,
16873 			    tlen, iptos);
16874 #ifdef TCP_ACCOUNTING
16875 			sched_unpin();
16876 #endif
16877 			return (1);
16878 		}
16879 		tcp_set_hpts(inp);
16880 		sack_filter_clear(&rack->r_ctl.rack_sf, th->th_ack);
16881 	}
16882 	if (thflags & TH_FIN)
16883 		tcp_log_end_status(tp, TCP_EI_STATUS_CLIENT_FIN);
16884 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
16885 	if ((rack->rc_gp_dyn_mul) &&
16886 	    (rack->use_fixed_rate == 0) &&
16887 	    (rack->rc_always_pace)) {
16888 		/* Check in on probertt */
16889 		rack_check_probe_rtt(rack, us_cts);
16890 	}
16891 	rack_clear_rate_sample(rack);
16892 	if ((rack->forced_ack) &&
16893 	    ((tcp_get_flags(th) & TH_RST) == 0)) {
16894 		rack_handle_probe_response(rack, tiwin, us_cts);
16895 	}
16896 	/*
16897 	 * This is the one exception case where we set the rack state
16898 	 * always. All other times (timers etc) we must have a rack-state
16899 	 * set (so we assure we have done the checks above for SACK).
16900 	 */
16901 	rack->r_ctl.rc_rcvtime = cts;
16902 	if (rack->r_state != tp->t_state)
16903 		rack_set_state(tp, rack);
16904 	if (SEQ_GT(th->th_ack, tp->snd_una) &&
16905 	    (rsm = tqhash_min(rack->r_ctl.tqh)) != NULL)
16906 		kern_prefetch(rsm, &prev_state);
16907 	prev_state = rack->r_state;
16908 	if ((thflags & TH_RST) &&
16909 	    ((SEQ_GEQ(th->th_seq, tp->last_ack_sent) &&
16910 	      SEQ_LT(th->th_seq, tp->last_ack_sent + tp->rcv_wnd)) ||
16911 	     (tp->rcv_wnd == 0 && tp->last_ack_sent == th->th_seq))) {
16912 		/* The connection will be killed by a reset check the tracepoint */
16913 		tcp_trace_point(rack->rc_tp, TCP_TP_RESET_RCV);
16914 	}
16915 	retval = (*rack->r_substate) (m, th, so,
16916 	    tp, &to, drop_hdrlen,
16917 	    tlen, tiwin, thflags, nxt_pkt, iptos);
16918 	if (retval == 0) {
16919 		/*
16920 		 * If retval is 1 the tcb is unlocked and most likely the tp
16921 		 * is gone.
16922 		 */
16923 		INP_WLOCK_ASSERT(inp);
16924 		if ((rack->rc_gp_dyn_mul) &&
16925 		    (rack->rc_always_pace) &&
16926 		    (rack->use_fixed_rate == 0) &&
16927 		    rack->in_probe_rtt &&
16928 		    (rack->r_ctl.rc_time_probertt_starts == 0)) {
16929 			/*
16930 			 * If we are going for target, lets recheck before
16931 			 * we output.
16932 			 */
16933 			rack_check_probe_rtt(rack, us_cts);
16934 		}
16935 		if (rack->set_pacing_done_a_iw == 0) {
16936 			/* How much has been acked? */
16937 			if ((tp->snd_una - tp->iss) > (ctf_fixed_maxseg(tp) * 10)) {
16938 				/* We have enough to set in the pacing segment size */
16939 				rack->set_pacing_done_a_iw = 1;
16940 				rack_set_pace_segments(tp, rack, __LINE__, NULL);
16941 			}
16942 		}
16943 		tcp_rack_xmit_timer_commit(rack, tp);
16944 #ifdef TCP_ACCOUNTING
16945 		/*
16946 		 * If we set the ack_val_se to what ack processing we are doing
16947 		 * we also want to track how many cycles we burned. Note
16948 		 * the bits after tcp_output we let be "free". This is because
16949 		 * we are also tracking the tcp_output times as well. Note the
16950 		 * use of 0xf here since we only have 11 counter (0 - 0xa) and
16951 		 * 0xf cannot be returned and is what we initialize it too to
16952 		 * indicate we are not doing the tabulations.
16953 		 */
16954 		if (ack_val_set != 0xf) {
16955 			uint64_t crtsc;
16956 
16957 			crtsc = get_cyclecount();
16958 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16959 				tp->tcp_proc_time[ack_val_set] += (crtsc - ts_val);
16960 			}
16961 		}
16962 #endif
16963 		if ((nxt_pkt == 0) && (no_output == 0)) {
16964 			if ((rack->r_wanted_output != 0) || (rack->r_fast_output != 0)) {
16965 do_output_now:
16966 				if (tcp_output(tp) < 0) {
16967 #ifdef TCP_ACCOUNTING
16968 					sched_unpin();
16969 #endif
16970 					return (1);
16971 				}
16972 				did_out = 1;
16973 			}
16974 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
16975 			rack_free_trim(rack);
16976 		} else if ((no_output == 1) &&
16977 			   (nxt_pkt == 0)  &&
16978 			   (tcp_in_hpts(rack->rc_inp) == 0)) {
16979 			/*
16980 			 * We are not in hpts and we had a pacing timer up. Use
16981 			 * the remaining time (slot_remaining) to restart the timer.
16982 			 */
16983 			KASSERT ((slot_remaining != 0), ("slot remaining is zero for rack:%p tp:%p", rack, tp));
16984 			rack_start_hpts_timer(rack, tp, cts, slot_remaining, 0, 0);
16985 			rack_free_trim(rack);
16986 		}
16987 		/* Update any rounds needed */
16988 		if (rack_verbose_logging &&  tcp_bblogging_on(rack->rc_tp))
16989 			rack_log_hystart_event(rack, high_seq, 8);
16990 		/*
16991 		 * The draft (v3) calls for us to use SEQ_GEQ, but that
16992 		 * causes issues when we are just going app limited. Lets
16993 		 * instead use SEQ_GT <or> where its equal but more data
16994 		 * is outstanding.
16995 		 *
16996 		 * Also make sure we are on the last ack of a series. We
16997 		 * have to have all the ack's processed in queue to know
16998 		 * if there is something left outstanding.
16999 		 */
17000 		if (SEQ_GEQ(tp->snd_una, rack->r_ctl.roundends) &&
17001 		    (rack->rc_new_rnd_needed == 0) &&
17002 		    (nxt_pkt == 0)) {
17003 			rack_log_hystart_event(rack, tp->snd_una, 21);
17004 			rack->r_ctl.current_round++;
17005 			/* Force the next send to setup the next round */
17006 			rack->rc_new_rnd_needed = 1;
17007 			if (CC_ALGO(tp)->newround != NULL) {
17008 				CC_ALGO(tp)->newround(&tp->t_ccv, rack->r_ctl.current_round);
17009 			}
17010 		}
17011 		if ((nxt_pkt == 0) &&
17012 		    ((rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) == 0) &&
17013 		    (SEQ_GT(tp->snd_max, tp->snd_una) ||
17014 		     (tp->t_flags & TF_DELACK) ||
17015 		     ((V_tcp_always_keepalive || rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
17016 		      (tp->t_state <= TCPS_CLOSING)))) {
17017 			/* We could not send (probably in the hpts but stopped the timer earlier)? */
17018 			if ((tp->snd_max == tp->snd_una) &&
17019 			    ((tp->t_flags & TF_DELACK) == 0) &&
17020 			    (tcp_in_hpts(rack->rc_inp)) &&
17021 			    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
17022 				/* keep alive not needed if we are hptsi output yet */
17023 				;
17024 			} else {
17025 				int late = 0;
17026 				if (tcp_in_hpts(inp)) {
17027 					if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
17028 						us_cts = tcp_get_usecs(NULL);
17029 						if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
17030 							rack->r_early = 1;
17031 							rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
17032 						} else
17033 							late = 1;
17034 						rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
17035 					}
17036 					tcp_hpts_remove(inp);
17037 				}
17038 				if (late && (did_out == 0)) {
17039 					/*
17040 					 * We are late in the sending
17041 					 * and we did not call the output
17042 					 * (this probably should not happen).
17043 					 */
17044 					goto do_output_now;
17045 				}
17046 				rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
17047 			}
17048 			way_out = 1;
17049 		} else if (nxt_pkt == 0) {
17050 			/* Do we have the correct timer running? */
17051 			rack_timer_audit(tp, rack, &so->so_snd);
17052 			way_out = 2;
17053 		}
17054 	done_with_input:
17055 		rack_log_doseg_done(rack, cts, nxt_pkt, did_out, way_out, max(1, nsegs));
17056 		if (did_out)
17057 			rack->r_wanted_output = 0;
17058 	}
17059 #ifdef TCP_ACCOUNTING
17060 	sched_unpin();
17061 #endif
17062 	return (retval);
17063 }
17064 
17065 static void
17066 rack_do_segment(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
17067     int32_t drop_hdrlen, int32_t tlen, uint8_t iptos)
17068 {
17069 	struct timeval tv;
17070 
17071 	/* First lets see if we have old packets */
17072 	if (tp->t_in_pkt) {
17073 		if (ctf_do_queued_segments(tp, 1)) {
17074 			m_freem(m);
17075 			return;
17076 		}
17077 	}
17078 	if (m->m_flags & M_TSTMP_LRO) {
17079 		mbuf_tstmp2timeval(m, &tv);
17080 	} else {
17081 		/* Should not be should we kassert instead? */
17082 		tcp_get_usecs(&tv);
17083 	}
17084 	if (rack_do_segment_nounlock(tp, m, th, drop_hdrlen, tlen, iptos, 0,
17085 	    &tv) == 0) {
17086 		INP_WUNLOCK(tptoinpcb(tp));
17087 	}
17088 }
17089 
17090 struct rack_sendmap *
17091 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack, uint32_t tsused)
17092 {
17093 	struct rack_sendmap *rsm = NULL;
17094 	int32_t idx;
17095 	uint32_t srtt = 0, thresh = 0, ts_low = 0;
17096 	int no_sack = 0;
17097 
17098 	/* Return the next guy to be re-transmitted */
17099 	if (tqhash_empty(rack->r_ctl.tqh)) {
17100 		return (NULL);
17101 	}
17102 	if (tp->t_flags & TF_SENTFIN) {
17103 		/* retran the end FIN? */
17104 		return (NULL);
17105 	}
17106 	/* ok lets look at this one */
17107 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
17108 	if (rack->r_must_retran && rsm && (rsm->r_flags & RACK_MUST_RXT)) {
17109 		return (rsm);
17110 	}
17111 	if (rsm && ((rsm->r_flags & RACK_ACKED) == 0)) {
17112 		goto check_it;
17113 	}
17114 	rsm = rack_find_lowest_rsm(rack);
17115 	if (rsm == NULL) {
17116 		return (NULL);
17117 	}
17118 check_it:
17119 	if (((rack->rc_tp->t_flags & TF_SACK_PERMIT) == 0) ||
17120 	    (rack->sack_attack_disable > 0)) {
17121 		no_sack = 1;
17122 	}
17123 	if ((no_sack > 0) &&
17124 	    (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
17125 		/*
17126 		 * No sack so we automatically do the 3 strikes and
17127 		 * retransmit (no rack timer would be started).
17128 		 */
17129 		return (rsm);
17130 	}
17131 	if (rsm->r_flags & RACK_ACKED) {
17132 		return (NULL);
17133 	}
17134 	if (((rsm->r_flags & RACK_SACK_PASSED) == 0) &&
17135 	    (rsm->r_dupack < DUP_ACK_THRESHOLD)) {
17136 		/* Its not yet ready */
17137 		return (NULL);
17138 	}
17139 	srtt = rack_grab_rtt(tp, rack);
17140 	idx = rsm->r_rtr_cnt - 1;
17141 	ts_low = (uint32_t)rsm->r_tim_lastsent[idx];
17142 	thresh = rack_calc_thresh_rack(rack, srtt, tsused);
17143 	if ((tsused == ts_low) ||
17144 	    (TSTMP_LT(tsused, ts_low))) {
17145 		/* No time since sending */
17146 		return (NULL);
17147 	}
17148 	if ((tsused - ts_low) < thresh) {
17149 		/* It has not been long enough yet */
17150 		return (NULL);
17151 	}
17152 	if ((rsm->r_dupack >= DUP_ACK_THRESHOLD) ||
17153 	    ((rsm->r_flags & RACK_SACK_PASSED) &&
17154 	     (rack->sack_attack_disable == 0))) {
17155 		/*
17156 		 * We have passed the dup-ack threshold <or>
17157 		 * a SACK has indicated this is missing.
17158 		 * Note that if you are a declared attacker
17159 		 * it is only the dup-ack threshold that
17160 		 * will cause retransmits.
17161 		 */
17162 		/* log retransmit reason */
17163 		rack_log_retran_reason(rack, rsm, (tsused - ts_low), thresh, 1);
17164 		rack->r_fast_output = 0;
17165 		return (rsm);
17166 	}
17167 	return (NULL);
17168 }
17169 
17170 static void
17171 rack_log_pacing_delay_calc(struct tcp_rack *rack, uint32_t len, uint32_t slot,
17172 			   uint64_t bw_est, uint64_t bw, uint64_t len_time, int method,
17173 			   int line, struct rack_sendmap *rsm, uint8_t quality)
17174 {
17175 	if (tcp_bblogging_on(rack->rc_tp)) {
17176 		union tcp_log_stackspecific log;
17177 		struct timeval tv;
17178 
17179 		memset(&log, 0, sizeof(log));
17180 		log.u_bbr.flex1 = slot;
17181 		log.u_bbr.flex2 = len;
17182 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_min_segs;
17183 		log.u_bbr.flex4 = rack->r_ctl.rc_pace_max_segs;
17184 		log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ss;
17185 		log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_ca;
17186 		log.u_bbr.use_lt_bw = rack->rc_ack_can_sendout_data;
17187 		log.u_bbr.use_lt_bw <<= 1;
17188 		log.u_bbr.use_lt_bw |= rack->r_late;
17189 		log.u_bbr.use_lt_bw <<= 1;
17190 		log.u_bbr.use_lt_bw |= rack->r_early;
17191 		log.u_bbr.use_lt_bw <<= 1;
17192 		log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
17193 		log.u_bbr.use_lt_bw <<= 1;
17194 		log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
17195 		log.u_bbr.use_lt_bw <<= 1;
17196 		log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
17197 		log.u_bbr.use_lt_bw <<= 1;
17198 		log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
17199 		log.u_bbr.use_lt_bw <<= 1;
17200 		log.u_bbr.use_lt_bw |= rack->gp_ready;
17201 		log.u_bbr.pkt_epoch = line;
17202 		log.u_bbr.epoch = rack->r_ctl.rc_agg_delayed;
17203 		log.u_bbr.lt_epoch = rack->r_ctl.rc_agg_early;
17204 		log.u_bbr.applimited = rack->r_ctl.rack_per_of_gp_rec;
17205 		log.u_bbr.bw_inuse = bw_est;
17206 		log.u_bbr.delRate = bw;
17207 		if (rack->r_ctl.gp_bw == 0)
17208 			log.u_bbr.cur_del_rate = 0;
17209 		else
17210 			log.u_bbr.cur_del_rate = rack_get_bw(rack);
17211 		log.u_bbr.rttProp = len_time;
17212 		log.u_bbr.pkts_out = rack->r_ctl.rc_rack_min_rtt;
17213 		log.u_bbr.lost = rack->r_ctl.rc_probertt_sndmax_atexit;
17214 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
17215 		if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh) {
17216 			/* We are in slow start */
17217 			log.u_bbr.flex7 = 1;
17218 		} else {
17219 			/* we are on congestion avoidance */
17220 			log.u_bbr.flex7 = 0;
17221 		}
17222 		log.u_bbr.flex8 = method;
17223 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
17224 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
17225 		log.u_bbr.cwnd_gain = rack->rc_gp_saw_rec;
17226 		log.u_bbr.cwnd_gain <<= 1;
17227 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
17228 		log.u_bbr.cwnd_gain <<= 1;
17229 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
17230 		log.u_bbr.bbr_substate = quality;
17231 		log.u_bbr.bbr_state = rack->dgp_on;
17232 		log.u_bbr.bbr_state <<= 1;
17233 		log.u_bbr.bbr_state |= rack->r_fill_less_agg;
17234 		log.u_bbr.bbr_state <<= 1;
17235 		log.u_bbr.bbr_state |= rack->rc_pace_to_cwnd;
17236 		log.u_bbr.bbr_state <<= 2;
17237 		log.u_bbr.bbr_state |= rack->r_pacing_discount;
17238 		log.u_bbr.flex7 = ((rack->r_ctl.pacing_discount_amm << 1) | log.u_bbr.flex7);
17239 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
17240 		    &rack->rc_inp->inp_socket->so_rcv,
17241 		    &rack->rc_inp->inp_socket->so_snd,
17242 		    BBR_LOG_HPTSI_CALC, 0,
17243 		    0, &log, false, &tv);
17244 	}
17245 }
17246 
17247 static uint32_t
17248 rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss)
17249 {
17250 	uint32_t new_tso, user_max, pace_one;
17251 
17252 	user_max = rack->rc_user_set_max_segs * mss;
17253 	if (rack->rc_force_max_seg) {
17254 		return (user_max);
17255 	}
17256 	if (rack->use_fixed_rate &&
17257 	    ((rack->r_ctl.crte == NULL) ||
17258 	     (bw != rack->r_ctl.crte->rate))) {
17259 		/* Use the user mss since we are not exactly matched */
17260 		return (user_max);
17261 	}
17262 	if (rack_pace_one_seg ||
17263 	    (rack->r_ctl.rc_user_set_min_segs == 1))
17264 		pace_one = 1;
17265 	else
17266 		pace_one = 0;
17267 
17268 	new_tso = tcp_get_pacing_burst_size_w_divisor(rack->rc_tp, bw, mss,
17269 		     pace_one, rack->r_ctl.crte, NULL, rack->r_ctl.pace_len_divisor);
17270 	if (new_tso > user_max)
17271 		new_tso = user_max;
17272 	if (rack->rc_hybrid_mode && rack->r_ctl.client_suggested_maxseg) {
17273 		if (((uint32_t)rack->r_ctl.client_suggested_maxseg * mss) > new_tso)
17274 			new_tso = (uint32_t)rack->r_ctl.client_suggested_maxseg * mss;
17275 	}
17276 	if (rack->r_ctl.rc_user_set_min_segs &&
17277 	    ((rack->r_ctl.rc_user_set_min_segs * mss) > new_tso))
17278 	    new_tso = rack->r_ctl.rc_user_set_min_segs * mss;
17279 	return (new_tso);
17280 }
17281 
17282 static int32_t
17283 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)
17284 {
17285 	uint64_t lentim, fill_bw;
17286 
17287 	/* Lets first see if we are full, if so continue with normal rate */
17288 	rack->r_via_fill_cw = 0;
17289 	if (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.cwnd_to_use)
17290 		return (slot);
17291 	if ((ctf_outstanding(rack->rc_tp) + (segsiz-1)) > rack->rc_tp->snd_wnd)
17292 		return (slot);
17293 	if (rack->r_ctl.rc_last_us_rtt == 0)
17294 		return (slot);
17295 	if (rack->rc_pace_fill_if_rttin_range &&
17296 	    (rack->r_ctl.rc_last_us_rtt >=
17297 	     (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack->rtt_limit_mul))) {
17298 		/* The rtt is huge, N * smallest, lets not fill */
17299 		return (slot);
17300 	}
17301 	/*
17302 	 * first lets calculate the b/w based on the last us-rtt
17303 	 * and the the smallest send window.
17304 	 */
17305 	fill_bw = min(rack->rc_tp->snd_cwnd, rack->r_ctl.cwnd_to_use);
17306 	/* Take the rwnd if its smaller */
17307 	if (fill_bw > rack->rc_tp->snd_wnd)
17308 		fill_bw = rack->rc_tp->snd_wnd;
17309 	/* Now lets make it into a b/w */
17310 	fill_bw *= (uint64_t)HPTS_USEC_IN_SEC;
17311 	fill_bw /= (uint64_t)rack->r_ctl.rc_last_us_rtt;
17312 	if (rack->r_fill_less_agg) {
17313 		/*
17314 		 * We want the average of the rate_wanted
17315 		 * and our fill-cw calculated bw. We also want
17316 		 * to cap any increase to be no more than
17317 		 * X times the lt_bw (where X is the rack_bw_multipler).
17318 		 */
17319 		uint64_t lt_bw, rate;
17320 
17321 		lt_bw = rack_get_lt_bw(rack);
17322 		if (lt_bw > *rate_wanted)
17323 			rate = lt_bw;
17324 		else
17325 			rate = *rate_wanted;
17326 		fill_bw += rate;
17327 		fill_bw /= 2;
17328 		if (rack_bw_multipler && (fill_bw > (rate * rack_bw_multipler))) {
17329 			fill_bw = rate * rack_bw_multipler;
17330 		}
17331 	}
17332 	/* We are below the min b/w */
17333 	if (non_paced)
17334 		*rate_wanted = fill_bw;
17335 	if ((fill_bw < RACK_MIN_BW) || (fill_bw < *rate_wanted))
17336 		return (slot);
17337 	rack->r_via_fill_cw = 1;
17338 	if (rack->r_rack_hw_rate_caps &&
17339 	    (rack->r_ctl.crte != NULL)) {
17340 		uint64_t high_rate;
17341 
17342 		high_rate = tcp_hw_highest_rate(rack->r_ctl.crte);
17343 		if (fill_bw > high_rate) {
17344 			/* We are capping bw at the highest rate table entry */
17345 			if (*rate_wanted > high_rate) {
17346 				/* The original rate was also capped */
17347 				rack->r_via_fill_cw = 0;
17348 			}
17349 			rack_log_hdwr_pacing(rack,
17350 					     fill_bw, high_rate, __LINE__,
17351 					     0, 3);
17352 			fill_bw = high_rate;
17353 			if (capped)
17354 				*capped = 1;
17355 		}
17356 	} else if ((rack->r_ctl.crte == NULL) &&
17357 		   (rack->rack_hdrw_pacing == 0) &&
17358 		   (rack->rack_hdw_pace_ena) &&
17359 		   rack->r_rack_hw_rate_caps &&
17360 		   (rack->rack_attempt_hdwr_pace == 0) &&
17361 		   (rack->rc_inp->inp_route.ro_nh != NULL) &&
17362 		   (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
17363 		/*
17364 		 * Ok we may have a first attempt that is greater than our top rate
17365 		 * lets check.
17366 		 */
17367 		uint64_t high_rate;
17368 
17369 		high_rate = tcp_hw_highest_rate_ifp(rack->rc_inp->inp_route.ro_nh->nh_ifp, rack->rc_inp);
17370 		if (high_rate) {
17371 			if (fill_bw > high_rate) {
17372 				fill_bw = high_rate;
17373 				if (capped)
17374 					*capped = 1;
17375 			}
17376 		}
17377 	}
17378 	if (rack->r_ctl.bw_rate_cap && (fill_bw > rack->r_ctl.bw_rate_cap)) {
17379 		rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
17380 				   fill_bw, 0, 0, HYBRID_LOG_RATE_CAP, 2, NULL);
17381 		fill_bw = rack->r_ctl.bw_rate_cap;
17382 	}
17383 	/*
17384 	 * Ok fill_bw holds our mythical b/w to fill the cwnd
17385 	 * in an rtt (unless it was capped), what does that
17386 	 * time wise equate too?
17387 	 */
17388 	lentim = (uint64_t)(len) * (uint64_t)HPTS_USEC_IN_SEC;
17389 	lentim /= fill_bw;
17390 	*rate_wanted = fill_bw;
17391 	if (non_paced || (lentim < slot)) {
17392 		rack_log_pacing_delay_calc(rack, len, slot, fill_bw,
17393 					   0, lentim, 12, __LINE__, NULL, 0);
17394 		return ((int32_t)lentim);
17395 	} else
17396 		return (slot);
17397 }
17398 
17399 static int32_t
17400 rack_get_pacing_delay(struct tcp_rack *rack, struct tcpcb *tp, uint32_t len, struct rack_sendmap *rsm, uint32_t segsiz)
17401 {
17402 	uint64_t srtt;
17403 	int32_t slot = 0;
17404 	int32_t minslot = 0;
17405 	int can_start_hw_pacing = 1;
17406 	int err;
17407 	int pace_one;
17408 
17409 	if (rack_pace_one_seg ||
17410 	    (rack->r_ctl.rc_user_set_min_segs == 1))
17411 		pace_one = 1;
17412 	else
17413 		pace_one = 0;
17414 	if (rack->rc_always_pace == 0) {
17415 		/*
17416 		 * We use the most optimistic possible cwnd/srtt for
17417 		 * sending calculations. This will make our
17418 		 * calculation anticipate getting more through
17419 		 * quicker then possible. But thats ok we don't want
17420 		 * the peer to have a gap in data sending.
17421 		 */
17422 		uint64_t cwnd, tr_perms = 0;
17423 		int32_t reduce = 0;
17424 
17425 	old_method:
17426 		/*
17427 		 * We keep no precise pacing with the old method
17428 		 * instead we use the pacer to mitigate bursts.
17429 		 */
17430 		if (rack->r_ctl.rc_rack_min_rtt)
17431 			srtt = rack->r_ctl.rc_rack_min_rtt;
17432 		else
17433 			srtt = max(tp->t_srtt, 1);
17434 		if (rack->r_ctl.rc_rack_largest_cwnd)
17435 			cwnd = rack->r_ctl.rc_rack_largest_cwnd;
17436 		else
17437 			cwnd = rack->r_ctl.cwnd_to_use;
17438 		/* Inflate cwnd by 1000 so srtt of usecs is in ms */
17439 		tr_perms = (cwnd * 1000) / srtt;
17440 		if (tr_perms == 0) {
17441 			tr_perms = ctf_fixed_maxseg(tp);
17442 		}
17443 		/*
17444 		 * Calculate how long this will take to drain, if
17445 		 * the calculation comes out to zero, thats ok we
17446 		 * will use send_a_lot to possibly spin around for
17447 		 * more increasing tot_len_this_send to the point
17448 		 * that its going to require a pace, or we hit the
17449 		 * cwnd. Which in that case we are just waiting for
17450 		 * a ACK.
17451 		 */
17452 		slot = len / tr_perms;
17453 		/* Now do we reduce the time so we don't run dry? */
17454 		if (slot && rack_slot_reduction) {
17455 			reduce = (slot / rack_slot_reduction);
17456 			if (reduce < slot) {
17457 				slot -= reduce;
17458 			} else
17459 				slot = 0;
17460 		}
17461 		slot *= HPTS_USEC_IN_MSEC;
17462 		if (rack->rc_pace_to_cwnd) {
17463 			uint64_t rate_wanted = 0;
17464 
17465 			slot = pace_to_fill_cwnd(rack, slot, len, segsiz, NULL, &rate_wanted, 1);
17466 			rack->rc_ack_can_sendout_data = 1;
17467 			rack_log_pacing_delay_calc(rack, len, slot, rate_wanted, 0, 0, 14, __LINE__, NULL, 0);
17468 		} else
17469 			rack_log_pacing_delay_calc(rack, len, slot, tr_perms, reduce, 0, 7, __LINE__, NULL, 0);
17470 		/*******************************************************/
17471 		/* RRS: We insert non-paced call to stats here for len */
17472 		/*******************************************************/
17473 	} else {
17474 		uint64_t bw_est, res, lentim, rate_wanted;
17475 		uint32_t segs, oh;
17476 		int capped = 0;
17477 		int prev_fill;
17478 
17479 		if ((rack->r_rr_config == 1) && rsm) {
17480 			return (rack->r_ctl.rc_min_to);
17481 		}
17482 		if (rack->use_fixed_rate) {
17483 			rate_wanted = bw_est = rack_get_fixed_pacing_bw(rack);
17484 		} else if ((rack->r_ctl.init_rate == 0) &&
17485 			   (rack->r_ctl.gp_bw == 0)) {
17486 			/* no way to yet do an estimate */
17487 			bw_est = rate_wanted = 0;
17488 		} else {
17489 			bw_est = rack_get_bw(rack);
17490 			rate_wanted = rack_get_output_bw(rack, bw_est, rsm, &capped);
17491 		}
17492 		if ((bw_est == 0) || (rate_wanted == 0) ||
17493 		    ((rack->gp_ready == 0) && (rack->use_fixed_rate == 0))) {
17494 			/*
17495 			 * No way yet to make a b/w estimate or
17496 			 * our raise is set incorrectly.
17497 			 */
17498 			goto old_method;
17499 		}
17500 		rack_rate_cap_bw(rack, &rate_wanted, &capped);
17501 		/* We need to account for all the overheads */
17502 		segs = (len + segsiz - 1) / segsiz;
17503 		/*
17504 		 * We need the diff between 1514 bytes (e-mtu with e-hdr)
17505 		 * and how much data we put in each packet. Yes this
17506 		 * means we may be off if we are larger than 1500 bytes
17507 		 * or smaller. But this just makes us more conservative.
17508 		 */
17509 
17510 		oh =  (tp->t_maxseg - segsiz) + sizeof(struct tcphdr);
17511 		if (rack->r_is_v6) {
17512 #ifdef INET6
17513 			oh += sizeof(struct ip6_hdr);
17514 #endif
17515 		} else {
17516 #ifdef INET
17517 			oh += sizeof(struct ip);
17518 #endif
17519 		}
17520 		/* We add a fixed 14 for the ethernet header */
17521 		oh += 14;
17522 		segs *= oh;
17523 		lentim = (uint64_t)(len + segs) * (uint64_t)HPTS_USEC_IN_SEC;
17524 		res = lentim / rate_wanted;
17525 		slot = (uint32_t)res;
17526 		if (rack_hw_rate_min &&
17527 		    (rate_wanted < rack_hw_rate_min)) {
17528 			can_start_hw_pacing = 0;
17529 			if (rack->r_ctl.crte) {
17530 				/*
17531 				 * Ok we need to release it, we
17532 				 * have fallen too low.
17533 				 */
17534 				tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
17535 				rack->r_ctl.crte = NULL;
17536 				rack->rack_attempt_hdwr_pace = 0;
17537 				rack->rack_hdrw_pacing = 0;
17538 			}
17539 		}
17540 		if (rack->r_ctl.crte &&
17541 		    (tcp_hw_highest_rate(rack->r_ctl.crte) < rate_wanted)) {
17542 			/*
17543 			 * We want more than the hardware can give us,
17544 			 * don't start any hw pacing.
17545 			 */
17546 			can_start_hw_pacing = 0;
17547 			if (rack->r_rack_hw_rate_caps == 0) {
17548 				/*
17549 				 * Ok we need to release it, we
17550 				 * want more than the card can give us and
17551 				 * no rate cap is in place. Set it up so
17552 				 * when we want less we can retry.
17553 				 */
17554 				tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
17555 				rack->r_ctl.crte = NULL;
17556 				rack->rack_attempt_hdwr_pace = 0;
17557 				rack->rack_hdrw_pacing = 0;
17558 			}
17559 		}
17560 		if ((rack->r_ctl.crte != NULL) && (rack->rc_inp->inp_snd_tag == NULL)) {
17561 			/*
17562 			 * We lost our rate somehow, this can happen
17563 			 * if the interface changed underneath us.
17564 			 */
17565 			tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
17566 			rack->r_ctl.crte = NULL;
17567 			/* Lets re-allow attempting to setup pacing */
17568 			rack->rack_hdrw_pacing = 0;
17569 			rack->rack_attempt_hdwr_pace = 0;
17570 			rack_log_hdwr_pacing(rack,
17571 					     rate_wanted, bw_est, __LINE__,
17572 					     0, 6);
17573 		}
17574 		prev_fill = rack->r_via_fill_cw;
17575 		if ((rack->rc_pace_to_cwnd) &&
17576 		    (capped == 0) &&
17577 		    (rack->use_fixed_rate == 0) &&
17578 		    (rack->in_probe_rtt == 0) &&
17579 		    (IN_FASTRECOVERY(rack->rc_tp->t_flags) == 0)) {
17580 			/*
17581 			 * We want to pace at our rate *or* faster to
17582 			 * fill the cwnd to the max if its not full.
17583 			 */
17584 			slot = pace_to_fill_cwnd(rack, slot, (len+segs), segsiz, &capped, &rate_wanted, 0);
17585 			/* Re-check to make sure we are not exceeding our max b/w */
17586 			if ((rack->r_ctl.crte != NULL) &&
17587 			    (tcp_hw_highest_rate(rack->r_ctl.crte) < rate_wanted)) {
17588 				/*
17589 				 * We want more than the hardware can give us,
17590 				 * don't start any hw pacing.
17591 				 */
17592 				can_start_hw_pacing = 0;
17593 				if (rack->r_rack_hw_rate_caps == 0) {
17594 					/*
17595 					 * Ok we need to release it, we
17596 					 * want more than the card can give us and
17597 					 * no rate cap is in place. Set it up so
17598 					 * when we want less we can retry.
17599 					 */
17600 					tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
17601 					rack->r_ctl.crte = NULL;
17602 					rack->rack_attempt_hdwr_pace = 0;
17603 					rack->rack_hdrw_pacing = 0;
17604 					rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
17605 				}
17606 			}
17607 		}
17608 		if ((rack->rc_inp->inp_route.ro_nh != NULL) &&
17609 		    (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
17610 			if ((rack->rack_hdw_pace_ena) &&
17611 			    (can_start_hw_pacing > 0) &&
17612 			    (rack->rack_hdrw_pacing == 0) &&
17613 			    (rack->rack_attempt_hdwr_pace == 0)) {
17614 				/*
17615 				 * Lets attempt to turn on hardware pacing
17616 				 * if we can.
17617 				 */
17618 				rack->rack_attempt_hdwr_pace = 1;
17619 				rack->r_ctl.crte = tcp_set_pacing_rate(rack->rc_tp,
17620 								       rack->rc_inp->inp_route.ro_nh->nh_ifp,
17621 								       rate_wanted,
17622 								       RS_PACING_GEQ,
17623 								       &err, &rack->r_ctl.crte_prev_rate);
17624 				if (rack->r_ctl.crte) {
17625 					rack->rack_hdrw_pacing = 1;
17626 					rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size_w_divisor(tp, rate_wanted, segsiz,
17627 									  pace_one, rack->r_ctl.crte,
17628 									  NULL, rack->r_ctl.pace_len_divisor);
17629 					rack_log_hdwr_pacing(rack,
17630 							     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
17631 							     err, 0);
17632 					rack->r_ctl.last_hw_bw_req = rate_wanted;
17633 				} else {
17634 					counter_u64_add(rack_hw_pace_init_fail, 1);
17635 				}
17636 			} else if (rack->rack_hdrw_pacing &&
17637 				   (rack->r_ctl.last_hw_bw_req != rate_wanted)) {
17638 				/* Do we need to adjust our rate? */
17639 				const struct tcp_hwrate_limit_table *nrte;
17640 
17641 				if (rack->r_up_only &&
17642 				    (rate_wanted < rack->r_ctl.crte->rate)) {
17643 					/**
17644 					 * We have four possible states here
17645 					 * having to do with the previous time
17646 					 * and this time.
17647 					 *   previous  |  this-time
17648 					 * A)     0      |     0   -- fill_cw not in the picture
17649 					 * B)     1      |     0   -- we were doing a fill-cw but now are not
17650 					 * C)     1      |     1   -- all rates from fill_cw
17651 					 * D)     0      |     1   -- we were doing non-fill and now we are filling
17652 					 *
17653 					 * For case A, C and D we don't allow a drop. But for
17654 					 * case B where we now our on our steady rate we do
17655 					 * allow a drop.
17656 					 *
17657 					 */
17658 					if (!((prev_fill == 1) && (rack->r_via_fill_cw == 0)))
17659 						goto done_w_hdwr;
17660 				}
17661 				if ((rate_wanted > rack->r_ctl.crte->rate) ||
17662 				    (rate_wanted <= rack->r_ctl.crte_prev_rate)) {
17663 					if (rack_hw_rate_to_low &&
17664 					    (bw_est < rack_hw_rate_to_low)) {
17665 						/*
17666 						 * The pacing rate is too low for hardware, but
17667 						 * do allow hardware pacing to be restarted.
17668 						 */
17669 						rack_log_hdwr_pacing(rack,
17670 							     bw_est, rack->r_ctl.crte->rate, __LINE__,
17671 							     0, 5);
17672 						tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
17673 						rack->r_ctl.crte = NULL;
17674 						rack->rack_attempt_hdwr_pace = 0;
17675 						rack->rack_hdrw_pacing = 0;
17676 						rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
17677 						goto done_w_hdwr;
17678 					}
17679 					nrte = tcp_chg_pacing_rate(rack->r_ctl.crte,
17680 									    rack->rc_tp,
17681 									    rack->rc_inp->inp_route.ro_nh->nh_ifp,
17682 									    rate_wanted,
17683 									    RS_PACING_GEQ,
17684 									    &err, &rack->r_ctl.crte_prev_rate);
17685 					if (nrte == NULL) {
17686 						/*
17687 						 * Lost the rate, lets drop hardware pacing
17688 						 * period.
17689 						 */
17690 						rack->rack_hdrw_pacing = 0;
17691 						rack->r_ctl.crte = NULL;
17692 						rack_log_hdwr_pacing(rack,
17693 								     rate_wanted, 0, __LINE__,
17694 								     err, 1);
17695 						rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
17696 						counter_u64_add(rack_hw_pace_lost, 1);
17697 					} else if (nrte != rack->r_ctl.crte) {
17698 						rack->r_ctl.crte = nrte;
17699 						rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size_w_divisor(tp, rate_wanted,
17700 										 segsiz, pace_one, rack->r_ctl.crte,
17701 										 NULL, rack->r_ctl.pace_len_divisor);
17702 						rack_log_hdwr_pacing(rack,
17703 								     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
17704 								     err, 2);
17705 						rack->r_ctl.last_hw_bw_req = rate_wanted;
17706 					}
17707 				} else {
17708 					/* We just need to adjust the segment size */
17709 					rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
17710 					rack_log_hdwr_pacing(rack,
17711 							     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
17712 							     0, 4);
17713 					rack->r_ctl.last_hw_bw_req = rate_wanted;
17714 				}
17715 			}
17716 		}
17717 		if (minslot && (minslot > slot)) {
17718 			rack_log_pacing_delay_calc(rack, minslot, slot, rack->r_ctl.crte->rate, bw_est, lentim,
17719 						   98, __LINE__, NULL, 0);
17720 			slot = minslot;
17721 		}
17722 done_w_hdwr:
17723 		if (rack_limit_time_with_srtt &&
17724 		    (rack->use_fixed_rate == 0) &&
17725 		    (rack->rack_hdrw_pacing == 0)) {
17726 			/*
17727 			 * Sanity check, we do not allow the pacing delay
17728 			 * to be longer than the SRTT of the path. If it is
17729 			 * a slow path, then adding a packet should increase
17730 			 * the RTT and compensate for this i.e. the srtt will
17731 			 * be greater so the allowed pacing time will be greater.
17732 			 *
17733 			 * Note this restriction is not for where a peak rate
17734 			 * is set, we are doing fixed pacing or hardware pacing.
17735 			 */
17736 			if (rack->rc_tp->t_srtt)
17737 				srtt = rack->rc_tp->t_srtt;
17738 			else
17739 				srtt = RACK_INITIAL_RTO * HPTS_USEC_IN_MSEC;	/* its in ms convert */
17740 			if (srtt < (uint64_t)slot) {
17741 				rack_log_pacing_delay_calc(rack, srtt, slot, rate_wanted, bw_est, lentim, 99, __LINE__, NULL, 0);
17742 				slot = srtt;
17743 			}
17744 		}
17745 		/*******************************************************************/
17746 		/* RRS: We insert paced call to stats here for len and rate_wanted */
17747 		/*******************************************************************/
17748 		rack_log_pacing_delay_calc(rack, len, slot, rate_wanted, bw_est, lentim, 2, __LINE__, rsm, 0);
17749 	}
17750 	if (rack->r_ctl.crte && (rack->r_ctl.crte->rs_num_enobufs > 0)) {
17751 		/*
17752 		 * If this rate is seeing enobufs when it
17753 		 * goes to send then either the nic is out
17754 		 * of gas or we are mis-estimating the time
17755 		 * somehow and not letting the queue empty
17756 		 * completely. Lets add to the pacing time.
17757 		 */
17758 		int hw_boost_delay;
17759 
17760 		hw_boost_delay = rack->r_ctl.crte->time_between * rack_enobuf_hw_boost_mult;
17761 		if (hw_boost_delay > rack_enobuf_hw_max)
17762 			hw_boost_delay = rack_enobuf_hw_max;
17763 		else if (hw_boost_delay < rack_enobuf_hw_min)
17764 			hw_boost_delay = rack_enobuf_hw_min;
17765 		slot += hw_boost_delay;
17766 	}
17767 	return (slot);
17768 }
17769 
17770 static void
17771 rack_start_gp_measurement(struct tcpcb *tp, struct tcp_rack *rack,
17772     tcp_seq startseq, uint32_t sb_offset)
17773 {
17774 	struct rack_sendmap *my_rsm = NULL;
17775 
17776 	if (tp->t_state < TCPS_ESTABLISHED) {
17777 		/*
17778 		 * We don't start any measurements if we are
17779 		 * not at least established.
17780 		 */
17781 		return;
17782 	}
17783 	if (tp->t_state >= TCPS_FIN_WAIT_1) {
17784 		/*
17785 		 * We will get no more data into the SB
17786 		 * this means we need to have the data available
17787 		 * before we start a measurement.
17788 		 */
17789 
17790 		if (sbavail(&tptosocket(tp)->so_snd) <
17791 		    max(rc_init_window(rack),
17792 			(MIN_GP_WIN * ctf_fixed_maxseg(tp)))) {
17793 			/* Nope not enough data */
17794 			return;
17795 		}
17796 	}
17797 	tp->t_flags |= TF_GPUTINPROG;
17798 	rack->r_ctl.rc_gp_cumack_ts = 0;
17799 	rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
17800 	rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
17801 	tp->gput_seq = startseq;
17802 	rack->app_limited_needs_set = 0;
17803 	if (rack->in_probe_rtt)
17804 		rack->measure_saw_probe_rtt = 1;
17805 	else if ((rack->measure_saw_probe_rtt) &&
17806 		 (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
17807 		rack->measure_saw_probe_rtt = 0;
17808 	if (rack->rc_gp_filled)
17809 		tp->gput_ts = rack->r_ctl.last_cumack_advance;
17810 	else {
17811 		/* Special case initial measurement */
17812 		struct timeval tv;
17813 
17814 		tp->gput_ts = tcp_get_usecs(&tv);
17815 		rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
17816 	}
17817 	/*
17818 	 * We take a guess out into the future,
17819 	 * if we have no measurement and no
17820 	 * initial rate, we measure the first
17821 	 * initial-windows worth of data to
17822 	 * speed up getting some GP measurement and
17823 	 * thus start pacing.
17824 	 */
17825 	if ((rack->rc_gp_filled == 0) && (rack->r_ctl.init_rate == 0)) {
17826 		rack->app_limited_needs_set = 1;
17827 		tp->gput_ack = startseq + max(rc_init_window(rack),
17828 					      (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
17829 		rack_log_pacing_delay_calc(rack,
17830 					   tp->gput_seq,
17831 					   tp->gput_ack,
17832 					   0,
17833 					   tp->gput_ts,
17834 					   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) | (uint64_t)rack->r_ctl.rc_gp_output_ts),
17835 					   9,
17836 					   __LINE__, NULL, 0);
17837 		rack_tend_gp_marks(tp, rack);
17838 		rack_log_gpset(rack, tp->gput_ack, 0, 0, __LINE__, 1, NULL);
17839 		return;
17840 	}
17841 	if (sb_offset) {
17842 		/*
17843 		 * We are out somewhere in the sb
17844 		 * can we use the already outstanding data?
17845 		 */
17846 
17847 		if (rack->r_ctl.rc_app_limited_cnt == 0) {
17848 			/*
17849 			 * Yes first one is good and in this case
17850 			 * the tp->gput_ts is correctly set based on
17851 			 * the last ack that arrived (no need to
17852 			 * set things up when an ack comes in).
17853 			 */
17854 			my_rsm = tqhash_min(rack->r_ctl.tqh);
17855 			if ((my_rsm == NULL) ||
17856 			    (my_rsm->r_rtr_cnt != 1)) {
17857 				/* retransmission? */
17858 				goto use_latest;
17859 			}
17860 		} else {
17861 			if (rack->r_ctl.rc_first_appl == NULL) {
17862 				/*
17863 				 * If rc_first_appl is NULL
17864 				 * then the cnt should be 0.
17865 				 * This is probably an error, maybe
17866 				 * a KASSERT would be approprate.
17867 				 */
17868 				goto use_latest;
17869 			}
17870 			/*
17871 			 * If we have a marker pointer to the last one that is
17872 			 * app limited we can use that, but we need to set
17873 			 * things up so that when it gets ack'ed we record
17874 			 * the ack time (if its not already acked).
17875 			 */
17876 			rack->app_limited_needs_set = 1;
17877 			/*
17878 			 * We want to get to the rsm that is either
17879 			 * next with space i.e. over 1 MSS or the one
17880 			 * after that (after the app-limited).
17881 			 */
17882 			my_rsm = tqhash_next(rack->r_ctl.tqh, rack->r_ctl.rc_first_appl);
17883 			if (my_rsm) {
17884 				if ((my_rsm->r_end - my_rsm->r_start) <= ctf_fixed_maxseg(tp))
17885 					/* Have to use the next one */
17886 					my_rsm = tqhash_next(rack->r_ctl.tqh, my_rsm);
17887 				else {
17888 					/* Use after the first MSS of it is acked */
17889 					tp->gput_seq = my_rsm->r_start + ctf_fixed_maxseg(tp);
17890 					goto start_set;
17891 				}
17892 			}
17893 			if ((my_rsm == NULL) ||
17894 			    (my_rsm->r_rtr_cnt != 1)) {
17895 				/*
17896 				 * Either its a retransmit or
17897 				 * the last is the app-limited one.
17898 				 */
17899 				goto use_latest;
17900 			}
17901 		}
17902 		tp->gput_seq = my_rsm->r_start;
17903 start_set:
17904 		if (my_rsm->r_flags & RACK_ACKED) {
17905 			/*
17906 			 * This one has been acked use the arrival ack time
17907 			 */
17908 			struct rack_sendmap *nrsm;
17909 
17910 			tp->gput_ts = (uint32_t)my_rsm->r_ack_arrival;
17911 			rack->app_limited_needs_set = 0;
17912 			/*
17913 			 * Ok in this path we need to use the r_end now
17914 			 * since this guy is the starting ack.
17915 			 */
17916 			tp->gput_seq = my_rsm->r_end;
17917 			/*
17918 			 * We also need to adjust up the sendtime
17919 			 * to the send of the next data after my_rsm.
17920 			 */
17921 			nrsm = tqhash_next(rack->r_ctl.tqh, my_rsm);
17922 			if (nrsm != NULL)
17923 				my_rsm = nrsm;
17924 			else {
17925 				/*
17926 				 * The next as not been sent, thats the
17927 				 * case for using the latest.
17928 				 */
17929 				goto use_latest;
17930 			}
17931 		}
17932 		rack->r_ctl.rc_gp_output_ts = my_rsm->r_tim_lastsent[0];
17933 		tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
17934 		rack->r_ctl.rc_gp_cumack_ts = 0;
17935 		rack_log_pacing_delay_calc(rack,
17936 					   tp->gput_seq,
17937 					   tp->gput_ack,
17938 					   (uint64_t)my_rsm,
17939 					   tp->gput_ts,
17940 					   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) | (uint64_t)rack->r_ctl.rc_gp_output_ts),
17941 					   9,
17942 					   __LINE__, my_rsm, 0);
17943 		/* Now lets make sure all are marked as they should be */
17944 		rack_tend_gp_marks(tp, rack);
17945 		rack_log_gpset(rack, tp->gput_ack, 0, 0, __LINE__, 1, NULL);
17946 		return;
17947 	}
17948 
17949 use_latest:
17950 	/*
17951 	 * We don't know how long we may have been
17952 	 * idle or if this is the first-send. Lets
17953 	 * setup the flag so we will trim off
17954 	 * the first ack'd data so we get a true
17955 	 * measurement.
17956 	 */
17957 	rack->app_limited_needs_set = 1;
17958 	tp->gput_ack = startseq + rack_get_measure_window(tp, rack);
17959 	rack->r_ctl.rc_gp_cumack_ts = 0;
17960 	/* Find this guy so we can pull the send time */
17961 	my_rsm = tqhash_find(rack->r_ctl.tqh, startseq);
17962 	if (my_rsm) {
17963 		rack->r_ctl.rc_gp_output_ts = my_rsm->r_tim_lastsent[0];
17964 		if (my_rsm->r_flags & RACK_ACKED) {
17965 			/*
17966 			 * Unlikely since its probably what was
17967 			 * just transmitted (but I am paranoid).
17968 			 */
17969 			tp->gput_ts = (uint32_t)my_rsm->r_ack_arrival;
17970 			rack->app_limited_needs_set = 0;
17971 		}
17972 		if (SEQ_LT(my_rsm->r_start, tp->gput_seq)) {
17973 			/* This also is unlikely */
17974 			tp->gput_seq = my_rsm->r_start;
17975 		}
17976 	} else {
17977 		/*
17978 		 * TSNH unless we have some send-map limit,
17979 		 * and even at that it should not be hitting
17980 		 * that limit (we should have stopped sending).
17981 		 */
17982 		struct timeval tv;
17983 
17984 		microuptime(&tv);
17985 		rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
17986 	}
17987 	rack_tend_gp_marks(tp, rack);
17988 	rack_log_pacing_delay_calc(rack,
17989 				   tp->gput_seq,
17990 				   tp->gput_ack,
17991 				   (uint64_t)my_rsm,
17992 				   tp->gput_ts,
17993 				   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) | (uint64_t)rack->r_ctl.rc_gp_output_ts),
17994 				   9, __LINE__, NULL, 0);
17995 	rack_log_gpset(rack, tp->gput_ack, 0, 0, __LINE__, 1, NULL);
17996 }
17997 
17998 static inline uint32_t
17999 rack_what_can_we_send(struct tcpcb *tp, struct tcp_rack *rack,  uint32_t cwnd_to_use,
18000     uint32_t avail, int32_t sb_offset)
18001 {
18002 	uint32_t len;
18003 	uint32_t sendwin;
18004 
18005 	if (tp->snd_wnd > cwnd_to_use)
18006 		sendwin = cwnd_to_use;
18007 	else
18008 		sendwin = tp->snd_wnd;
18009 	if (ctf_outstanding(tp) >= tp->snd_wnd) {
18010 		/* We never want to go over our peers rcv-window */
18011 		len = 0;
18012 	} else {
18013 		uint32_t flight;
18014 
18015 		flight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
18016 		if (flight >= sendwin) {
18017 			/*
18018 			 * We have in flight what we are allowed by cwnd (if
18019 			 * it was rwnd blocking it would have hit above out
18020 			 * >= tp->snd_wnd).
18021 			 */
18022 			return (0);
18023 		}
18024 		len = sendwin - flight;
18025 		if ((len + ctf_outstanding(tp)) > tp->snd_wnd) {
18026 			/* We would send too much (beyond the rwnd) */
18027 			len = tp->snd_wnd - ctf_outstanding(tp);
18028 		}
18029 		if ((len + sb_offset) > avail) {
18030 			/*
18031 			 * We don't have that much in the SB, how much is
18032 			 * there?
18033 			 */
18034 			len = avail - sb_offset;
18035 		}
18036 	}
18037 	return (len);
18038 }
18039 
18040 static void
18041 rack_log_fsb(struct tcp_rack *rack, struct tcpcb *tp, struct socket *so, uint32_t flags,
18042 	     unsigned ipoptlen, int32_t orig_len, int32_t len, int error,
18043 	     int rsm_is_null, int optlen, int line, uint16_t mode)
18044 {
18045 	if (tcp_bblogging_on(rack->rc_tp)) {
18046 		union tcp_log_stackspecific log;
18047 		struct timeval tv;
18048 
18049 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
18050 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
18051 		log.u_bbr.flex1 = error;
18052 		log.u_bbr.flex2 = flags;
18053 		log.u_bbr.flex3 = rsm_is_null;
18054 		log.u_bbr.flex4 = ipoptlen;
18055 		log.u_bbr.flex5 = tp->rcv_numsacks;
18056 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
18057 		log.u_bbr.flex7 = optlen;
18058 		log.u_bbr.flex8 = rack->r_fsb_inited;
18059 		log.u_bbr.applimited = rack->r_fast_output;
18060 		log.u_bbr.bw_inuse = rack_get_bw(rack);
18061 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
18062 		log.u_bbr.cwnd_gain = mode;
18063 		log.u_bbr.pkts_out = orig_len;
18064 		log.u_bbr.lt_epoch = len;
18065 		log.u_bbr.delivered = line;
18066 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
18067 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
18068 		tcp_log_event(tp, NULL, &so->so_rcv, &so->so_snd, TCP_LOG_FSB, 0,
18069 			       len, &log, false, NULL, __func__, __LINE__, &tv);
18070 	}
18071 }
18072 
18073 
18074 static struct mbuf *
18075 rack_fo_base_copym(struct mbuf *the_m, uint32_t the_off, int32_t *plen,
18076 		   struct rack_fast_send_blk *fsb,
18077 		   int32_t seglimit, int32_t segsize, int hw_tls)
18078 {
18079 #ifdef KERN_TLS
18080 	struct ktls_session *tls, *ntls;
18081 #ifdef INVARIANTS
18082 	struct mbuf *start;
18083 #endif
18084 #endif
18085 	struct mbuf *m, *n, **np, *smb;
18086 	struct mbuf *top;
18087 	int32_t off, soff;
18088 	int32_t len = *plen;
18089 	int32_t fragsize;
18090 	int32_t len_cp = 0;
18091 	uint32_t mlen, frags;
18092 
18093 	soff = off = the_off;
18094 	smb = m = the_m;
18095 	np = &top;
18096 	top = NULL;
18097 #ifdef KERN_TLS
18098 	if (hw_tls && (m->m_flags & M_EXTPG))
18099 		tls = m->m_epg_tls;
18100 	else
18101 		tls = NULL;
18102 #ifdef INVARIANTS
18103 	start = m;
18104 #endif
18105 #endif
18106 	while (len > 0) {
18107 		if (m == NULL) {
18108 			*plen = len_cp;
18109 			break;
18110 		}
18111 #ifdef KERN_TLS
18112 		if (hw_tls) {
18113 			if (m->m_flags & M_EXTPG)
18114 				ntls = m->m_epg_tls;
18115 			else
18116 				ntls = NULL;
18117 
18118 			/*
18119 			 * Avoid mixing TLS records with handshake
18120 			 * data or TLS records from different
18121 			 * sessions.
18122 			 */
18123 			if (tls != ntls) {
18124 				MPASS(m != start);
18125 				*plen = len_cp;
18126 				break;
18127 			}
18128 		}
18129 #endif
18130 		mlen = min(len, m->m_len - off);
18131 		if (seglimit) {
18132 			/*
18133 			 * For M_EXTPG mbufs, add 3 segments
18134 			 * + 1 in case we are crossing page boundaries
18135 			 * + 2 in case the TLS hdr/trailer are used
18136 			 * It is cheaper to just add the segments
18137 			 * than it is to take the cache miss to look
18138 			 * at the mbuf ext_pgs state in detail.
18139 			 */
18140 			if (m->m_flags & M_EXTPG) {
18141 				fragsize = min(segsize, PAGE_SIZE);
18142 				frags = 3;
18143 			} else {
18144 				fragsize = segsize;
18145 				frags = 0;
18146 			}
18147 
18148 			/* Break if we really can't fit anymore. */
18149 			if ((frags + 1) >= seglimit) {
18150 				*plen =	len_cp;
18151 				break;
18152 			}
18153 
18154 			/*
18155 			 * Reduce size if you can't copy the whole
18156 			 * mbuf. If we can't copy the whole mbuf, also
18157 			 * adjust len so the loop will end after this
18158 			 * mbuf.
18159 			 */
18160 			if ((frags + howmany(mlen, fragsize)) >= seglimit) {
18161 				mlen = (seglimit - frags - 1) * fragsize;
18162 				len = mlen;
18163 				*plen = len_cp + len;
18164 			}
18165 			frags += howmany(mlen, fragsize);
18166 			if (frags == 0)
18167 				frags++;
18168 			seglimit -= frags;
18169 			KASSERT(seglimit > 0,
18170 			    ("%s: seglimit went too low", __func__));
18171 		}
18172 		n = m_get(M_NOWAIT, m->m_type);
18173 		*np = n;
18174 		if (n == NULL)
18175 			goto nospace;
18176 		n->m_len = mlen;
18177 		soff += mlen;
18178 		len_cp += n->m_len;
18179 		if (m->m_flags & (M_EXT|M_EXTPG)) {
18180 			n->m_data = m->m_data + off;
18181 			mb_dupcl(n, m);
18182 		} else {
18183 			bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t),
18184 			    (u_int)n->m_len);
18185 		}
18186 		len -= n->m_len;
18187 		off = 0;
18188 		m = m->m_next;
18189 		np = &n->m_next;
18190 		if (len || (soff == smb->m_len)) {
18191 			/*
18192 			 * We have more so we move forward  or
18193 			 * we have consumed the entire mbuf and
18194 			 * len has fell to 0.
18195 			 */
18196 			soff = 0;
18197 			smb = m;
18198 		}
18199 
18200 	}
18201 	if (fsb != NULL) {
18202 		fsb->m = smb;
18203 		fsb->off = soff;
18204 		if (smb) {
18205 			/*
18206 			 * Save off the size of the mbuf. We do
18207 			 * this so that we can recognize when it
18208 			 * has been trimmed by sbcut() as acks
18209 			 * come in.
18210 			 */
18211 			fsb->o_m_len = smb->m_len;
18212 			fsb->o_t_len = M_TRAILINGROOM(smb);
18213 		} else {
18214 			/*
18215 			 * This is the case where the next mbuf went to NULL. This
18216 			 * means with this copy we have sent everything in the sb.
18217 			 * In theory we could clear the fast_output flag, but lets
18218 			 * not since its possible that we could get more added
18219 			 * and acks that call the extend function which would let
18220 			 * us send more.
18221 			 */
18222 			fsb->o_m_len = 0;
18223 			fsb->o_t_len = 0;
18224 		}
18225 	}
18226 	return (top);
18227 nospace:
18228 	if (top)
18229 		m_freem(top);
18230 	return (NULL);
18231 
18232 }
18233 
18234 /*
18235  * This is a copy of m_copym(), taking the TSO segment size/limit
18236  * constraints into account, and advancing the sndptr as it goes.
18237  */
18238 static struct mbuf *
18239 rack_fo_m_copym(struct tcp_rack *rack, int32_t *plen,
18240 		int32_t seglimit, int32_t segsize, struct mbuf **s_mb, int *s_soff)
18241 {
18242 	struct mbuf *m, *n;
18243 	int32_t soff;
18244 
18245 	m = rack->r_ctl.fsb.m;
18246 	if (M_TRAILINGROOM(m) != rack->r_ctl.fsb.o_t_len) {
18247 		/*
18248 		 * The trailing space changed, mbufs can grow
18249 		 * at the tail but they can't shrink from
18250 		 * it, KASSERT that. Adjust the orig_m_len to
18251 		 * compensate for this change.
18252 		 */
18253 		KASSERT((rack->r_ctl.fsb.o_t_len > M_TRAILINGROOM(m)),
18254 			("mbuf:%p rack:%p trailing_space:%jd ots:%u oml:%u mlen:%u\n",
18255 			 m,
18256 			 rack,
18257 			 (intmax_t)M_TRAILINGROOM(m),
18258 			 rack->r_ctl.fsb.o_t_len,
18259 			 rack->r_ctl.fsb.o_m_len,
18260 			 m->m_len));
18261 		rack->r_ctl.fsb.o_m_len += (rack->r_ctl.fsb.o_t_len - M_TRAILINGROOM(m));
18262 		rack->r_ctl.fsb.o_t_len = M_TRAILINGROOM(m);
18263 	}
18264 	if (m->m_len < rack->r_ctl.fsb.o_m_len) {
18265 		/*
18266 		 * Mbuf shrank, trimmed off the top by an ack, our
18267 		 * offset changes.
18268 		 */
18269 		KASSERT((rack->r_ctl.fsb.off >= (rack->r_ctl.fsb.o_m_len - m->m_len)),
18270 			("mbuf:%p len:%u rack:%p oml:%u soff:%u\n",
18271 			 m, m->m_len,
18272 			 rack, rack->r_ctl.fsb.o_m_len,
18273 			 rack->r_ctl.fsb.off));
18274 
18275 		if (rack->r_ctl.fsb.off >= (rack->r_ctl.fsb.o_m_len- m->m_len))
18276 			rack->r_ctl.fsb.off -= (rack->r_ctl.fsb.o_m_len - m->m_len);
18277 		else
18278 			rack->r_ctl.fsb.off = 0;
18279 		rack->r_ctl.fsb.o_m_len = m->m_len;
18280 #ifdef INVARIANTS
18281 	} else if (m->m_len > rack->r_ctl.fsb.o_m_len) {
18282 		panic("rack:%p m:%p m_len grew outside of t_space compensation",
18283 		      rack, m);
18284 #endif
18285 	}
18286 	soff = rack->r_ctl.fsb.off;
18287 	KASSERT(soff >= 0, ("%s, negative off %d", __FUNCTION__, soff));
18288 	KASSERT(*plen >= 0, ("%s, negative len %d", __FUNCTION__, *plen));
18289 	KASSERT(soff < m->m_len, ("%s rack:%p len:%u m:%p m->m_len:%u < off?",
18290 				 __FUNCTION__,
18291 				 rack, *plen, m, m->m_len));
18292 	/* Save off the right location before we copy and advance */
18293 	*s_soff = soff;
18294 	*s_mb = rack->r_ctl.fsb.m;
18295 	n = rack_fo_base_copym(m, soff, plen,
18296 			       &rack->r_ctl.fsb,
18297 			       seglimit, segsize, rack->r_ctl.fsb.hw_tls);
18298 	return (n);
18299 }
18300 
18301 /* Log the buffer level */
18302 static void
18303 rack_log_queue_level(struct tcpcb *tp, struct tcp_rack *rack,
18304 		     int len, struct timeval *tv,
18305 		     uint32_t cts)
18306 {
18307 	uint32_t p_rate = 0, p_queue = 0, err = 0;
18308 	union tcp_log_stackspecific log;
18309 
18310 #ifdef RATELIMIT
18311 	err = in_pcbquery_txrlevel(rack->rc_inp, &p_queue);
18312 	err = in_pcbquery_txrtlmt(rack->rc_inp,	&p_rate);
18313 #endif
18314 	memset(&log.u_bbr, 0, sizeof(log.u_bbr));
18315 	log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
18316 	log.u_bbr.flex1 = p_rate;
18317 	log.u_bbr.flex2 = p_queue;
18318 	log.u_bbr.flex4 = (uint32_t)rack->r_ctl.crte->using;
18319 	log.u_bbr.flex5 = (uint32_t)rack->r_ctl.crte->rs_num_enobufs;
18320 	log.u_bbr.flex6 = rack->r_ctl.crte->time_between;
18321 	log.u_bbr.flex7 = 99;
18322 	log.u_bbr.flex8 = 0;
18323 	log.u_bbr.pkts_out = err;
18324 	log.u_bbr.delRate = rack->r_ctl.crte->rate;
18325 	log.u_bbr.timeStamp = cts;
18326 	log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
18327 	tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_HDWR_PACE, 0,
18328 		       len, &log, false, NULL, __func__, __LINE__, tv);
18329 
18330 }
18331 
18332 static uint32_t
18333 rack_check_queue_level(struct tcp_rack *rack, struct tcpcb *tp,
18334 		       struct timeval *tv, uint32_t cts, int len, uint32_t segsiz)
18335 {
18336 	uint64_t lentime = 0;
18337 #ifdef RATELIMIT
18338 	uint32_t p_rate = 0, p_queue = 0, err;
18339 	union tcp_log_stackspecific log;
18340 	uint64_t bw;
18341 
18342 	err = in_pcbquery_txrlevel(rack->rc_inp, &p_queue);
18343 	/* Failed or queue is zero */
18344 	if (err || (p_queue == 0)) {
18345 		lentime = 0;
18346 		goto out;
18347 	}
18348 	err = in_pcbquery_txrtlmt(rack->rc_inp, &p_rate);
18349 	if (err) {
18350 		lentime = 0;
18351 		goto out;
18352 	}
18353 	/*
18354 	 * If we reach here we have some bytes in
18355 	 * the queue. The number returned is a value
18356 	 * between 0 and 0xffff where ffff is full
18357 	 * and 0 is empty. So how best to make this into
18358 	 * something usable?
18359 	 *
18360 	 * The "safer" way is lets take the b/w gotten
18361 	 * from the query (which should be our b/w rate)
18362 	 * and pretend that a full send (our rc_pace_max_segs)
18363 	 * is outstanding. We factor it so its as if a full
18364 	 * number of our MSS segment is terms of full
18365 	 * ethernet segments are outstanding.
18366 	 */
18367 	bw = p_rate / 8;
18368 	if (bw) {
18369 		lentime = (rack->r_ctl.rc_pace_max_segs / segsiz);
18370 		lentime *= ETHERNET_SEGMENT_SIZE;
18371 		lentime *= (uint64_t)HPTS_USEC_IN_SEC;
18372 		lentime /= bw;
18373 	} else {
18374 		/* TSNH -- KASSERT? */
18375 		lentime = 0;
18376 	}
18377 out:
18378 	if (tcp_bblogging_on(tp)) {
18379 		memset(&log, 0, sizeof(log));
18380 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
18381 		log.u_bbr.flex1 = p_rate;
18382 		log.u_bbr.flex2 = p_queue;
18383 		log.u_bbr.flex4 = (uint32_t)rack->r_ctl.crte->using;
18384 		log.u_bbr.flex5 = (uint32_t)rack->r_ctl.crte->rs_num_enobufs;
18385 		log.u_bbr.flex6 = rack->r_ctl.crte->time_between;
18386 		log.u_bbr.flex7 = 99;
18387 		log.u_bbr.flex8 = 0;
18388 		log.u_bbr.pkts_out = err;
18389 		log.u_bbr.delRate = rack->r_ctl.crte->rate;
18390 		log.u_bbr.cur_del_rate = lentime;
18391 		log.u_bbr.timeStamp = cts;
18392 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
18393 		tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_HDWR_PACE, 0,
18394 			       len, &log, false, NULL, __func__, __LINE__,tv);
18395 	}
18396 #endif
18397 	return ((uint32_t)lentime);
18398 }
18399 
18400 static int
18401 rack_fast_rsm_output(struct tcpcb *tp, struct tcp_rack *rack, struct rack_sendmap *rsm,
18402 		     uint64_t ts_val, uint32_t cts, uint32_t ms_cts, struct timeval *tv, int len, uint8_t doing_tlp)
18403 {
18404 	/*
18405 	 * Enter the fast retransmit path. We are given that a sched_pin is
18406 	 * in place (if accounting is compliled in) and the cycle count taken
18407 	 * at the entry is in the ts_val. The concept her is that the rsm
18408 	 * now holds the mbuf offsets and such so we can directly transmit
18409 	 * without a lot of overhead, the len field is already set for
18410 	 * us to prohibit us from sending too much (usually its 1MSS).
18411 	 */
18412 	struct ip *ip = NULL;
18413 	struct udphdr *udp = NULL;
18414 	struct tcphdr *th = NULL;
18415 	struct mbuf *m = NULL;
18416 	struct inpcb *inp;
18417 	uint8_t *cpto;
18418 	struct tcp_log_buffer *lgb;
18419 #ifdef TCP_ACCOUNTING
18420 	uint64_t crtsc;
18421 	int cnt_thru = 1;
18422 #endif
18423 	struct tcpopt to;
18424 	u_char opt[TCP_MAXOLEN];
18425 	uint32_t hdrlen, optlen;
18426 	int32_t slot, segsiz, max_val, tso = 0, error = 0, ulen = 0;
18427 	uint16_t flags;
18428 	uint32_t if_hw_tsomaxsegcount = 0, startseq;
18429 	uint32_t if_hw_tsomaxsegsize;
18430 	int32_t ip_sendflag = IP_NO_SND_TAG_RL;
18431 
18432 #ifdef INET6
18433 	struct ip6_hdr *ip6 = NULL;
18434 
18435 	if (rack->r_is_v6) {
18436 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
18437 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
18438 	} else
18439 #endif				/* INET6 */
18440 	{
18441 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
18442 		hdrlen = sizeof(struct tcpiphdr);
18443 	}
18444 	if (tp->t_port && (V_tcp_udp_tunneling_port == 0)) {
18445 		goto failed;
18446 	}
18447 	if (doing_tlp) {
18448 		/* Its a TLP add the flag, it may already be there but be sure */
18449 		rsm->r_flags |= RACK_TLP;
18450 	} else {
18451 		/* If it was a TLP it is not not on this retransmit */
18452 		rsm->r_flags &= ~RACK_TLP;
18453 	}
18454 	startseq = rsm->r_start;
18455 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
18456 	inp = rack->rc_inp;
18457 	to.to_flags = 0;
18458 	flags = tcp_outflags[tp->t_state];
18459 	if (flags & (TH_SYN|TH_RST)) {
18460 		goto failed;
18461 	}
18462 	if (rsm->r_flags & RACK_HAS_FIN) {
18463 		/* We can't send a FIN here */
18464 		goto failed;
18465 	}
18466 	if (flags & TH_FIN) {
18467 		/* We never send a FIN */
18468 		flags &= ~TH_FIN;
18469 	}
18470 	if (tp->t_flags & TF_RCVD_TSTMP) {
18471 		to.to_tsval = ms_cts + tp->ts_offset;
18472 		to.to_tsecr = tp->ts_recent;
18473 		to.to_flags = TOF_TS;
18474 	}
18475 	optlen = tcp_addoptions(&to, opt);
18476 	hdrlen += optlen;
18477 	udp = rack->r_ctl.fsb.udp;
18478 	if (udp)
18479 		hdrlen += sizeof(struct udphdr);
18480 	if (rack->r_ctl.rc_pace_max_segs)
18481 		max_val = rack->r_ctl.rc_pace_max_segs;
18482 	else if (rack->rc_user_set_max_segs)
18483 		max_val = rack->rc_user_set_max_segs * segsiz;
18484 	else
18485 		max_val = len;
18486 	if ((tp->t_flags & TF_TSO) &&
18487 	    V_tcp_do_tso &&
18488 	    (len > segsiz) &&
18489 	    (tp->t_port == 0))
18490 		tso = 1;
18491 #ifdef INET6
18492 	if (MHLEN < hdrlen + max_linkhdr)
18493 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
18494 	else
18495 #endif
18496 		m = m_gethdr(M_NOWAIT, MT_DATA);
18497 	if (m == NULL)
18498 		goto failed;
18499 	m->m_data += max_linkhdr;
18500 	m->m_len = hdrlen;
18501 	th = rack->r_ctl.fsb.th;
18502 	/* Establish the len to send */
18503 	if (len > max_val)
18504 		len = max_val;
18505 	if ((tso) && (len + optlen > segsiz)) {
18506 		uint32_t if_hw_tsomax;
18507 		int32_t max_len;
18508 
18509 		/* extract TSO information */
18510 		if_hw_tsomax = tp->t_tsomax;
18511 		if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
18512 		if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
18513 		/*
18514 		 * Check if we should limit by maximum payload
18515 		 * length:
18516 		 */
18517 		if (if_hw_tsomax != 0) {
18518 			/* compute maximum TSO length */
18519 			max_len = (if_hw_tsomax - hdrlen -
18520 				   max_linkhdr);
18521 			if (max_len <= 0) {
18522 				goto failed;
18523 			} else if (len > max_len) {
18524 				len = max_len;
18525 			}
18526 		}
18527 		if (len <= segsiz) {
18528 			/*
18529 			 * In case there are too many small fragments don't
18530 			 * use TSO:
18531 			 */
18532 			tso = 0;
18533 		}
18534 	} else {
18535 		tso = 0;
18536 	}
18537 	if ((tso == 0) && (len > segsiz))
18538 		len = segsiz;
18539 	(void)tcp_get_usecs(tv);
18540 	if ((len == 0) ||
18541 	    (len <= MHLEN - hdrlen - max_linkhdr)) {
18542 		goto failed;
18543 	}
18544 	th->th_seq = htonl(rsm->r_start);
18545 	th->th_ack = htonl(tp->rcv_nxt);
18546 	/*
18547 	 * The PUSH bit should only be applied
18548 	 * if the full retransmission is made. If
18549 	 * we are sending less than this is the
18550 	 * left hand edge and should not have
18551 	 * the PUSH bit.
18552 	 */
18553 	if ((rsm->r_flags & RACK_HAD_PUSH) &&
18554 	    (len == (rsm->r_end - rsm->r_start)))
18555 		flags |= TH_PUSH;
18556 	th->th_win = htons((u_short)(rack->r_ctl.fsb.recwin >> tp->rcv_scale));
18557 	if (th->th_win == 0) {
18558 		tp->t_sndzerowin++;
18559 		tp->t_flags |= TF_RXWIN0SENT;
18560 	} else
18561 		tp->t_flags &= ~TF_RXWIN0SENT;
18562 	if (rsm->r_flags & RACK_TLP) {
18563 		/*
18564 		 * TLP should not count in retran count, but
18565 		 * in its own bin
18566 		 */
18567 		counter_u64_add(rack_tlp_retran, 1);
18568 		counter_u64_add(rack_tlp_retran_bytes, len);
18569 	} else {
18570 		tp->t_sndrexmitpack++;
18571 		KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
18572 		KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
18573 	}
18574 #ifdef STATS
18575 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
18576 				 len);
18577 #endif
18578 	if (rsm->m == NULL)
18579 		goto failed;
18580 	if (rsm->m &&
18581 	    ((rsm->orig_m_len != rsm->m->m_len) ||
18582 	     (M_TRAILINGROOM(rsm->m) != rsm->orig_t_space))) {
18583 		/* Fix up the orig_m_len and possibly the mbuf offset */
18584 		rack_adjust_orig_mlen(rsm);
18585 	}
18586 	m->m_next = rack_fo_base_copym(rsm->m, rsm->soff, &len, NULL, if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, rsm->r_hw_tls);
18587 	if (len <= segsiz) {
18588 		/*
18589 		 * Must have ran out of mbufs for the copy
18590 		 * shorten it to no longer need tso. Lets
18591 		 * not put on sendalot since we are low on
18592 		 * mbufs.
18593 		 */
18594 		tso = 0;
18595 	}
18596 	if ((m->m_next == NULL) || (len <= 0)){
18597 		goto failed;
18598 	}
18599 	if (udp) {
18600 		if (rack->r_is_v6)
18601 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
18602 		else
18603 			ulen = hdrlen + len - sizeof(struct ip);
18604 		udp->uh_ulen = htons(ulen);
18605 	}
18606 	m->m_pkthdr.rcvif = (struct ifnet *)0;
18607 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
18608 	    (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))) {
18609 		int ect = tcp_ecn_output_established(tp, &flags, len, true);
18610 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
18611 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
18612 		    tp->t_flags2 &= ~TF2_ECN_SND_ECE;
18613 #ifdef INET6
18614 		if (rack->r_is_v6) {
18615 		    ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
18616 		    ip6->ip6_flow |= htonl(ect << 20);
18617 		}
18618 		else
18619 #endif
18620 		{
18621 		    ip->ip_tos &= ~IPTOS_ECN_MASK;
18622 		    ip->ip_tos |= ect;
18623 		}
18624 	}
18625 	if (rack->r_ctl.crte != NULL) {
18626 		/* See if we can send via the hw queue */
18627 		slot = rack_check_queue_level(rack, tp, tv, cts, len, segsiz);
18628 		/* If there is nothing in queue (no pacing time) we can send via the hw queue */
18629 		if (slot == 0)
18630 			ip_sendflag = 0;
18631 	}
18632 	tcp_set_flags(th, flags);
18633 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
18634 #ifdef INET6
18635 	if (rack->r_is_v6) {
18636 		if (tp->t_port) {
18637 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
18638 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
18639 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
18640 			th->th_sum = htons(0);
18641 			UDPSTAT_INC(udps_opackets);
18642 		} else {
18643 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
18644 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
18645 			th->th_sum = in6_cksum_pseudo(ip6,
18646 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
18647 						      0);
18648 		}
18649 	}
18650 #endif
18651 #if defined(INET6) && defined(INET)
18652 	else
18653 #endif
18654 #ifdef INET
18655 	{
18656 		if (tp->t_port) {
18657 			m->m_pkthdr.csum_flags = CSUM_UDP;
18658 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
18659 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
18660 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
18661 			th->th_sum = htons(0);
18662 			UDPSTAT_INC(udps_opackets);
18663 		} else {
18664 			m->m_pkthdr.csum_flags = CSUM_TCP;
18665 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
18666 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
18667 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
18668 									IPPROTO_TCP + len + optlen));
18669 		}
18670 		/* IP version must be set here for ipv4/ipv6 checking later */
18671 		KASSERT(ip->ip_v == IPVERSION,
18672 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
18673 	}
18674 #endif
18675 	if (tso) {
18676 		/*
18677 		 * Here we use segsiz since we have no added options besides
18678 		 * any standard timestamp options (no DSACKs or SACKS are sent
18679 		 * via either fast-path).
18680 		 */
18681 		KASSERT(len > segsiz,
18682 			("%s: len <= tso_segsz tp:%p", __func__, tp));
18683 		m->m_pkthdr.csum_flags |= CSUM_TSO;
18684 		m->m_pkthdr.tso_segsz = segsiz;
18685 	}
18686 #ifdef INET6
18687 	if (rack->r_is_v6) {
18688 		ip6->ip6_hlim = rack->r_ctl.fsb.hoplimit;
18689 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
18690 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
18691 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
18692 		else
18693 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
18694 	}
18695 #endif
18696 #if defined(INET) && defined(INET6)
18697 	else
18698 #endif
18699 #ifdef INET
18700 	{
18701 		ip->ip_len = htons(m->m_pkthdr.len);
18702 		ip->ip_ttl = rack->r_ctl.fsb.hoplimit;
18703 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
18704 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
18705 			if (tp->t_port == 0 || len < V_tcp_minmss) {
18706 				ip->ip_off |= htons(IP_DF);
18707 			}
18708 		} else {
18709 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
18710 		}
18711 	}
18712 #endif
18713 	if (doing_tlp == 0) {
18714 		/* Set we retransmitted */
18715 		rack->rc_gp_saw_rec = 1;
18716 	} else {
18717 		/* Its a TLP set ca or ss */
18718 		if (tp->snd_cwnd > tp->snd_ssthresh) {
18719 			/* Set we sent in CA */
18720 			rack->rc_gp_saw_ca = 1;
18721 		} else {
18722 			/* Set we sent in SS */
18723 			rack->rc_gp_saw_ss = 1;
18724 		}
18725 	}
18726 	/* Time to copy in our header */
18727 	cpto = mtod(m, uint8_t *);
18728 	memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
18729 	th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
18730 	if (optlen) {
18731 		bcopy(opt, th + 1, optlen);
18732 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
18733 	} else {
18734 		th->th_off = sizeof(struct tcphdr) >> 2;
18735 	}
18736 	if (tcp_bblogging_on(rack->rc_tp)) {
18737 		union tcp_log_stackspecific log;
18738 
18739 		if (rsm->r_flags & RACK_RWND_COLLAPSED) {
18740 			rack_log_collapse(rack, rsm->r_start, rsm->r_end, 0, __LINE__, 5, rsm->r_flags, rsm);
18741 			counter_u64_add(rack_collapsed_win_rxt, 1);
18742 			counter_u64_add(rack_collapsed_win_rxt_bytes, (rsm->r_end - rsm->r_start));
18743 		}
18744 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
18745 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
18746 		if (rack->rack_no_prr)
18747 			log.u_bbr.flex1 = 0;
18748 		else
18749 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
18750 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
18751 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
18752 		log.u_bbr.flex4 = max_val;
18753 		/* Save off the early/late values */
18754 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
18755 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
18756 		log.u_bbr.bw_inuse = rack_get_bw(rack);
18757 		log.u_bbr.cur_del_rate = rack->r_ctl.gp_bw;
18758 		if (doing_tlp == 0)
18759 			log.u_bbr.flex8 = 1;
18760 		else
18761 			log.u_bbr.flex8 = 2;
18762 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
18763 		log.u_bbr.flex7 = 55;
18764 		log.u_bbr.pkts_out = tp->t_maxseg;
18765 		log.u_bbr.timeStamp = cts;
18766 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
18767 		if (rsm && (rsm->r_rtr_cnt > 0)) {
18768 			/*
18769 			 * When we have a retransmit we want to log the
18770 			 * burst at send and flight at send from before.
18771 			 */
18772 			log.u_bbr.flex5 = rsm->r_fas;
18773 			log.u_bbr.bbr_substate = rsm->r_bas;
18774 		} else {
18775 			/*
18776 			 * This is currently unlikely until we do the
18777 			 * packet pair probes but I will add it for completeness.
18778 			 */
18779 			log.u_bbr.flex5 = log.u_bbr.inflight;
18780 			log.u_bbr.bbr_substate = (uint8_t)((len + segsiz - 1)/segsiz);
18781 		}
18782 		log.u_bbr.lt_epoch = rack->r_ctl.cwnd_to_use;
18783 		log.u_bbr.delivered = 0;
18784 		log.u_bbr.rttProp = (uint64_t)rsm;
18785 		log.u_bbr.delRate = rsm->r_flags;
18786 		log.u_bbr.delRate <<= 31;
18787 		log.u_bbr.delRate |= rack->r_must_retran;
18788 		log.u_bbr.delRate <<= 1;
18789 		log.u_bbr.delRate |= 1;
18790 		log.u_bbr.pkt_epoch = __LINE__;
18791 		lgb = tcp_log_event(tp, th, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
18792 				     len, &log, false, NULL, __func__, __LINE__, tv);
18793 	} else
18794 		lgb = NULL;
18795 	if ((rack->r_ctl.crte != NULL) &&
18796 	    tcp_bblogging_on(tp)) {
18797 		rack_log_queue_level(tp, rack, len, tv, cts);
18798 	}
18799 #ifdef INET6
18800 	if (rack->r_is_v6) {
18801 		error = ip6_output(m, NULL,
18802 				   &inp->inp_route6,
18803 				   ip_sendflag, NULL, NULL, inp);
18804 	}
18805 	else
18806 #endif
18807 #ifdef INET
18808 	{
18809 		error = ip_output(m, NULL,
18810 				  &inp->inp_route,
18811 				  ip_sendflag, 0, inp);
18812 	}
18813 #endif
18814 	m = NULL;
18815 	if (lgb) {
18816 		lgb->tlb_errno = error;
18817 		lgb = NULL;
18818 	}
18819 	if (error) {
18820 		goto failed;
18821 	} else if (rack->rc_hw_nobuf && (ip_sendflag != IP_NO_SND_TAG_RL)) {
18822 		rack->rc_hw_nobuf = 0;
18823 		rack->r_ctl.rc_agg_delayed = 0;
18824 		rack->r_early = 0;
18825 		rack->r_late = 0;
18826 		rack->r_ctl.rc_agg_early = 0;
18827 	}
18828 
18829 	rack_log_output(tp, &to, len, rsm->r_start, flags, error, rack_to_usec_ts(tv),
18830 			rsm, RACK_SENT_FP, rsm->m, rsm->soff, rsm->r_hw_tls, segsiz);
18831 	if (doing_tlp) {
18832 		rack->rc_tlp_in_progress = 1;
18833 		rack->r_ctl.rc_tlp_cnt_out++;
18834 	}
18835 	if (error == 0) {
18836 		counter_u64_add(rack_total_bytes, len);
18837 		tcp_account_for_send(tp, len, 1, doing_tlp, rsm->r_hw_tls);
18838 		if (doing_tlp) {
18839 			rack->rc_last_sent_tlp_past_cumack = 0;
18840 			rack->rc_last_sent_tlp_seq_valid = 1;
18841 			rack->r_ctl.last_sent_tlp_seq = rsm->r_start;
18842 			rack->r_ctl.last_sent_tlp_len = rsm->r_end - rsm->r_start;
18843 		}
18844 	}
18845 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
18846 	rack->forced_ack = 0;	/* If we send something zap the FA flag */
18847 	if (IN_FASTRECOVERY(tp->t_flags) && rsm)
18848 		rack->r_ctl.retran_during_recovery += len;
18849 	{
18850 		int idx;
18851 
18852 		idx = (len / segsiz) + 3;
18853 		if (idx >= TCP_MSS_ACCT_ATIMER)
18854 			counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
18855 		else
18856 			counter_u64_add(rack_out_size[idx], 1);
18857 	}
18858 	if (tp->t_rtttime == 0) {
18859 		tp->t_rtttime = ticks;
18860 		tp->t_rtseq = startseq;
18861 		KMOD_TCPSTAT_INC(tcps_segstimed);
18862 	}
18863 	counter_u64_add(rack_fto_rsm_send, 1);
18864 	if (error && (error == ENOBUFS)) {
18865 		if (rack->r_ctl.crte != NULL) {
18866 			tcp_trace_point(rack->rc_tp, TCP_TP_HWENOBUF);
18867 			if (tcp_bblogging_on(rack->rc_tp))
18868 				rack_log_queue_level(tp, rack, len, tv, cts);
18869 		} else
18870 			tcp_trace_point(rack->rc_tp, TCP_TP_ENOBUF);
18871 		slot = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
18872 		if (rack->rc_enobuf < 0x7f)
18873 			rack->rc_enobuf++;
18874 		if (slot < (10 * HPTS_USEC_IN_MSEC))
18875 			slot = 10 * HPTS_USEC_IN_MSEC;
18876 		if (rack->r_ctl.crte != NULL) {
18877 			counter_u64_add(rack_saw_enobuf_hw, 1);
18878 			tcp_rl_log_enobuf(rack->r_ctl.crte);
18879 		}
18880 		counter_u64_add(rack_saw_enobuf, 1);
18881 	} else
18882 		slot = rack_get_pacing_delay(rack, tp, len, NULL, segsiz);
18883 	if ((slot == 0) ||
18884 	    (rack->rc_always_pace == 0) ||
18885 	    (rack->r_rr_config == 1)) {
18886 		/*
18887 		 * We have no pacing set or we
18888 		 * are using old-style rack or
18889 		 * we are overridden to use the old 1ms pacing.
18890 		 */
18891 		slot = rack->r_ctl.rc_min_to;
18892 	}
18893 	rack_start_hpts_timer(rack, tp, cts, slot, len, 0);
18894 #ifdef TCP_ACCOUNTING
18895 	crtsc = get_cyclecount();
18896 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18897 		tp->tcp_cnt_counters[SND_OUT_DATA] += cnt_thru;
18898 	}
18899 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18900 		tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
18901 	}
18902 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18903 		tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((len + segsiz - 1) / segsiz);
18904 	}
18905 	sched_unpin();
18906 #endif
18907 	return (0);
18908 failed:
18909 	if (m)
18910 		m_free(m);
18911 	return (-1);
18912 }
18913 
18914 static void
18915 rack_sndbuf_autoscale(struct tcp_rack *rack)
18916 {
18917 	/*
18918 	 * Automatic sizing of send socket buffer.  Often the send buffer
18919 	 * size is not optimally adjusted to the actual network conditions
18920 	 * at hand (delay bandwidth product).  Setting the buffer size too
18921 	 * small limits throughput on links with high bandwidth and high
18922 	 * delay (eg. trans-continental/oceanic links).  Setting the
18923 	 * buffer size too big consumes too much real kernel memory,
18924 	 * especially with many connections on busy servers.
18925 	 *
18926 	 * The criteria to step up the send buffer one notch are:
18927 	 *  1. receive window of remote host is larger than send buffer
18928 	 *     (with a fudge factor of 5/4th);
18929 	 *  2. send buffer is filled to 7/8th with data (so we actually
18930 	 *     have data to make use of it);
18931 	 *  3. send buffer fill has not hit maximal automatic size;
18932 	 *  4. our send window (slow start and cogestion controlled) is
18933 	 *     larger than sent but unacknowledged data in send buffer.
18934 	 *
18935 	 * Note that the rack version moves things much faster since
18936 	 * we want to avoid hitting cache lines in the rack_fast_output()
18937 	 * path so this is called much less often and thus moves
18938 	 * the SB forward by a percentage.
18939 	 */
18940 	struct socket *so;
18941 	struct tcpcb *tp;
18942 	uint32_t sendwin, scaleup;
18943 
18944 	tp = rack->rc_tp;
18945 	so = rack->rc_inp->inp_socket;
18946 	sendwin = min(rack->r_ctl.cwnd_to_use, tp->snd_wnd);
18947 	if (V_tcp_do_autosndbuf && so->so_snd.sb_flags & SB_AUTOSIZE) {
18948 		if ((tp->snd_wnd / 4 * 5) >= so->so_snd.sb_hiwat &&
18949 		    sbused(&so->so_snd) >=
18950 		    (so->so_snd.sb_hiwat / 8 * 7) &&
18951 		    sbused(&so->so_snd) < V_tcp_autosndbuf_max &&
18952 		    sendwin >= (sbused(&so->so_snd) -
18953 		    (tp->snd_nxt - tp->snd_una))) {
18954 			if (rack_autosndbuf_inc)
18955 				scaleup = (rack_autosndbuf_inc * so->so_snd.sb_hiwat) / 100;
18956 			else
18957 				scaleup = V_tcp_autosndbuf_inc;
18958 			if (scaleup < V_tcp_autosndbuf_inc)
18959 				scaleup = V_tcp_autosndbuf_inc;
18960 			scaleup += so->so_snd.sb_hiwat;
18961 			if (scaleup > V_tcp_autosndbuf_max)
18962 				scaleup = V_tcp_autosndbuf_max;
18963 			if (!sbreserve_locked(so, SO_SND, scaleup, curthread))
18964 				so->so_snd.sb_flags &= ~SB_AUTOSIZE;
18965 		}
18966 	}
18967 }
18968 
18969 static int
18970 rack_fast_output(struct tcpcb *tp, struct tcp_rack *rack, uint64_t ts_val,
18971 		 uint32_t cts, uint32_t ms_cts, struct timeval *tv, long tot_len, int *send_err)
18972 {
18973 	/*
18974 	 * Enter to do fast output. We are given that the sched_pin is
18975 	 * in place (if accounting is compiled in) and the cycle count taken
18976 	 * at entry is in place in ts_val. The idea here is that
18977 	 * we know how many more bytes needs to be sent (presumably either
18978 	 * during pacing or to fill the cwnd and that was greater than
18979 	 * the max-burst). We have how much to send and all the info we
18980 	 * need to just send.
18981 	 */
18982 #ifdef INET
18983 	struct ip *ip = NULL;
18984 #endif
18985 	struct udphdr *udp = NULL;
18986 	struct tcphdr *th = NULL;
18987 	struct mbuf *m, *s_mb;
18988 	struct inpcb *inp;
18989 	uint8_t *cpto;
18990 	struct tcp_log_buffer *lgb;
18991 #ifdef TCP_ACCOUNTING
18992 	uint64_t crtsc;
18993 #endif
18994 	struct tcpopt to;
18995 	u_char opt[TCP_MAXOLEN];
18996 	uint32_t hdrlen, optlen;
18997 #ifdef TCP_ACCOUNTING
18998 	int cnt_thru = 1;
18999 #endif
19000 	int32_t slot, segsiz, len, max_val, tso = 0, sb_offset, error, ulen = 0;
19001 	uint16_t flags;
19002 	uint32_t s_soff;
19003 	uint32_t if_hw_tsomaxsegcount = 0, startseq;
19004 	uint32_t if_hw_tsomaxsegsize;
19005 	uint16_t add_flag = RACK_SENT_FP;
19006 #ifdef INET6
19007 	struct ip6_hdr *ip6 = NULL;
19008 
19009 	if (rack->r_is_v6) {
19010 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
19011 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
19012 	} else
19013 #endif				/* INET6 */
19014 	{
19015 #ifdef INET
19016 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
19017 		hdrlen = sizeof(struct tcpiphdr);
19018 #endif
19019 	}
19020 	if (tp->t_port && (V_tcp_udp_tunneling_port == 0)) {
19021 		m = NULL;
19022 		goto failed;
19023 	}
19024 	startseq = tp->snd_max;
19025 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
19026 	inp = rack->rc_inp;
19027 	len = rack->r_ctl.fsb.left_to_send;
19028 	to.to_flags = 0;
19029 	flags = rack->r_ctl.fsb.tcp_flags;
19030 	if (tp->t_flags & TF_RCVD_TSTMP) {
19031 		to.to_tsval = ms_cts + tp->ts_offset;
19032 		to.to_tsecr = tp->ts_recent;
19033 		to.to_flags = TOF_TS;
19034 	}
19035 	optlen = tcp_addoptions(&to, opt);
19036 	hdrlen += optlen;
19037 	udp = rack->r_ctl.fsb.udp;
19038 	if (udp)
19039 		hdrlen += sizeof(struct udphdr);
19040 	if (rack->r_ctl.rc_pace_max_segs)
19041 		max_val = rack->r_ctl.rc_pace_max_segs;
19042 	else if (rack->rc_user_set_max_segs)
19043 		max_val = rack->rc_user_set_max_segs * segsiz;
19044 	else
19045 		max_val = len;
19046 	if ((tp->t_flags & TF_TSO) &&
19047 	    V_tcp_do_tso &&
19048 	    (len > segsiz) &&
19049 	    (tp->t_port == 0))
19050 		tso = 1;
19051 again:
19052 #ifdef INET6
19053 	if (MHLEN < hdrlen + max_linkhdr)
19054 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
19055 	else
19056 #endif
19057 		m = m_gethdr(M_NOWAIT, MT_DATA);
19058 	if (m == NULL)
19059 		goto failed;
19060 	m->m_data += max_linkhdr;
19061 	m->m_len = hdrlen;
19062 	th = rack->r_ctl.fsb.th;
19063 	/* Establish the len to send */
19064 	if (len > max_val)
19065 		len = max_val;
19066 	if ((tso) && (len + optlen > segsiz)) {
19067 		uint32_t if_hw_tsomax;
19068 		int32_t max_len;
19069 
19070 		/* extract TSO information */
19071 		if_hw_tsomax = tp->t_tsomax;
19072 		if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
19073 		if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
19074 		/*
19075 		 * Check if we should limit by maximum payload
19076 		 * length:
19077 		 */
19078 		if (if_hw_tsomax != 0) {
19079 			/* compute maximum TSO length */
19080 			max_len = (if_hw_tsomax - hdrlen -
19081 				   max_linkhdr);
19082 			if (max_len <= 0) {
19083 				goto failed;
19084 			} else if (len > max_len) {
19085 				len = max_len;
19086 			}
19087 		}
19088 		if (len <= segsiz) {
19089 			/*
19090 			 * In case there are too many small fragments don't
19091 			 * use TSO:
19092 			 */
19093 			tso = 0;
19094 		}
19095 	} else {
19096 		tso = 0;
19097 	}
19098 	if ((tso == 0) && (len > segsiz))
19099 		len = segsiz;
19100 	(void)tcp_get_usecs(tv);
19101 	if ((len == 0) ||
19102 	    (len <= MHLEN - hdrlen - max_linkhdr)) {
19103 		goto failed;
19104 	}
19105 	sb_offset = tp->snd_max - tp->snd_una;
19106 	th->th_seq = htonl(tp->snd_max);
19107 	th->th_ack = htonl(tp->rcv_nxt);
19108 	th->th_win = htons((u_short)(rack->r_ctl.fsb.recwin >> tp->rcv_scale));
19109 	if (th->th_win == 0) {
19110 		tp->t_sndzerowin++;
19111 		tp->t_flags |= TF_RXWIN0SENT;
19112 	} else
19113 		tp->t_flags &= ~TF_RXWIN0SENT;
19114 	tp->snd_up = tp->snd_una;	/* drag it along, its deprecated */
19115 	KMOD_TCPSTAT_INC(tcps_sndpack);
19116 	KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
19117 #ifdef STATS
19118 	stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
19119 				 len);
19120 #endif
19121 	if (rack->r_ctl.fsb.m == NULL)
19122 		goto failed;
19123 
19124 	/* s_mb and s_soff are saved for rack_log_output */
19125 	m->m_next = rack_fo_m_copym(rack, &len, if_hw_tsomaxsegcount, if_hw_tsomaxsegsize,
19126 				    &s_mb, &s_soff);
19127 	if (len <= segsiz) {
19128 		/*
19129 		 * Must have ran out of mbufs for the copy
19130 		 * shorten it to no longer need tso. Lets
19131 		 * not put on sendalot since we are low on
19132 		 * mbufs.
19133 		 */
19134 		tso = 0;
19135 	}
19136 	if (rack->r_ctl.fsb.rfo_apply_push &&
19137 	    (len == rack->r_ctl.fsb.left_to_send)) {
19138 		tcp_set_flags(th, flags | TH_PUSH);
19139 		add_flag |= RACK_HAD_PUSH;
19140 	}
19141 	if ((m->m_next == NULL) || (len <= 0)){
19142 		goto failed;
19143 	}
19144 	if (udp) {
19145 		if (rack->r_is_v6)
19146 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
19147 		else
19148 			ulen = hdrlen + len - sizeof(struct ip);
19149 		udp->uh_ulen = htons(ulen);
19150 	}
19151 	m->m_pkthdr.rcvif = (struct ifnet *)0;
19152 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
19153 	    (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))) {
19154 		int ect = tcp_ecn_output_established(tp, &flags, len, false);
19155 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
19156 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
19157 			tp->t_flags2 &= ~TF2_ECN_SND_ECE;
19158 #ifdef INET6
19159 		if (rack->r_is_v6) {
19160 			ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
19161 			ip6->ip6_flow |= htonl(ect << 20);
19162 		}
19163 		else
19164 #endif
19165 		{
19166 #ifdef INET
19167 			ip->ip_tos &= ~IPTOS_ECN_MASK;
19168 			ip->ip_tos |= ect;
19169 #endif
19170 		}
19171 	}
19172 	tcp_set_flags(th, flags);
19173 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
19174 #ifdef INET6
19175 	if (rack->r_is_v6) {
19176 		if (tp->t_port) {
19177 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
19178 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
19179 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
19180 			th->th_sum = htons(0);
19181 			UDPSTAT_INC(udps_opackets);
19182 		} else {
19183 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
19184 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
19185 			th->th_sum = in6_cksum_pseudo(ip6,
19186 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
19187 						      0);
19188 		}
19189 	}
19190 #endif
19191 #if defined(INET6) && defined(INET)
19192 	else
19193 #endif
19194 #ifdef INET
19195 	{
19196 		if (tp->t_port) {
19197 			m->m_pkthdr.csum_flags = CSUM_UDP;
19198 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
19199 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
19200 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
19201 			th->th_sum = htons(0);
19202 			UDPSTAT_INC(udps_opackets);
19203 		} else {
19204 			m->m_pkthdr.csum_flags = CSUM_TCP;
19205 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
19206 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
19207 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
19208 									IPPROTO_TCP + len + optlen));
19209 		}
19210 		/* IP version must be set here for ipv4/ipv6 checking later */
19211 		KASSERT(ip->ip_v == IPVERSION,
19212 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
19213 	}
19214 #endif
19215 	if (tso) {
19216 		/*
19217 		 * Here we use segsiz since we have no added options besides
19218 		 * any standard timestamp options (no DSACKs or SACKS are sent
19219 		 * via either fast-path).
19220 		 */
19221 		KASSERT(len > segsiz,
19222 			("%s: len <= tso_segsz tp:%p", __func__, tp));
19223 		m->m_pkthdr.csum_flags |= CSUM_TSO;
19224 		m->m_pkthdr.tso_segsz = segsiz;
19225 	}
19226 #ifdef INET6
19227 	if (rack->r_is_v6) {
19228 		ip6->ip6_hlim = rack->r_ctl.fsb.hoplimit;
19229 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
19230 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
19231 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
19232 		else
19233 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
19234 	}
19235 #endif
19236 #if defined(INET) && defined(INET6)
19237 	else
19238 #endif
19239 #ifdef INET
19240 	{
19241 		ip->ip_len = htons(m->m_pkthdr.len);
19242 		ip->ip_ttl = rack->r_ctl.fsb.hoplimit;
19243 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
19244 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
19245 			if (tp->t_port == 0 || len < V_tcp_minmss) {
19246 				ip->ip_off |= htons(IP_DF);
19247 			}
19248 		} else {
19249 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
19250 		}
19251 	}
19252 #endif
19253 	if (tp->snd_cwnd > tp->snd_ssthresh) {
19254 		/* Set we sent in CA */
19255 		rack->rc_gp_saw_ca = 1;
19256 	} else {
19257 		/* Set we sent in SS */
19258 		rack->rc_gp_saw_ss = 1;
19259 	}
19260 	/* Time to copy in our header */
19261 	cpto = mtod(m, uint8_t *);
19262 	memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
19263 	th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
19264 	if (optlen) {
19265 		bcopy(opt, th + 1, optlen);
19266 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
19267 	} else {
19268 		th->th_off = sizeof(struct tcphdr) >> 2;
19269 	}
19270 	if ((rack->r_ctl.crte != NULL) &&
19271 	    tcp_bblogging_on(tp)) {
19272 		rack_log_queue_level(tp, rack, len, tv, cts);
19273 	}
19274 	if (tcp_bblogging_on(rack->rc_tp)) {
19275 		union tcp_log_stackspecific log;
19276 
19277 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
19278 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
19279 		if (rack->rack_no_prr)
19280 			log.u_bbr.flex1 = 0;
19281 		else
19282 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
19283 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
19284 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
19285 		log.u_bbr.flex4 = max_val;
19286 		/* Save off the early/late values */
19287 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
19288 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
19289 		log.u_bbr.bw_inuse = rack_get_bw(rack);
19290 		log.u_bbr.cur_del_rate = rack->r_ctl.gp_bw;
19291 		log.u_bbr.flex8 = 0;
19292 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
19293 		log.u_bbr.flex7 = 44;
19294 		log.u_bbr.pkts_out = tp->t_maxseg;
19295 		log.u_bbr.timeStamp = cts;
19296 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
19297 		log.u_bbr.flex5 = log.u_bbr.inflight;
19298 		log.u_bbr.lt_epoch = rack->r_ctl.cwnd_to_use;
19299 		log.u_bbr.delivered = 0;
19300 		log.u_bbr.rttProp = 0;
19301 		log.u_bbr.delRate = rack->r_must_retran;
19302 		log.u_bbr.delRate <<= 1;
19303 		log.u_bbr.pkt_epoch = __LINE__;
19304 		/* For fast output no retrans so just inflight and how many mss we send */
19305 		log.u_bbr.flex5 = log.u_bbr.inflight;
19306 		log.u_bbr.bbr_substate = (uint8_t)((len + segsiz - 1)/segsiz);
19307 		lgb = tcp_log_event(tp, th, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
19308 				     len, &log, false, NULL, __func__, __LINE__, tv);
19309 	} else
19310 		lgb = NULL;
19311 #ifdef INET6
19312 	if (rack->r_is_v6) {
19313 		error = ip6_output(m, NULL,
19314 				   &inp->inp_route6,
19315 				   0, NULL, NULL, inp);
19316 	}
19317 #endif
19318 #if defined(INET) && defined(INET6)
19319 	else
19320 #endif
19321 #ifdef INET
19322 	{
19323 		error = ip_output(m, NULL,
19324 				  &inp->inp_route,
19325 				  0, 0, inp);
19326 	}
19327 #endif
19328 	if (lgb) {
19329 		lgb->tlb_errno = error;
19330 		lgb = NULL;
19331 	}
19332 	if (error) {
19333 		*send_err = error;
19334 		m = NULL;
19335 		goto failed;
19336 	} else if (rack->rc_hw_nobuf) {
19337 		rack->rc_hw_nobuf = 0;
19338 		rack->r_ctl.rc_agg_delayed = 0;
19339 		rack->r_early = 0;
19340 		rack->r_late = 0;
19341 		rack->r_ctl.rc_agg_early = 0;
19342 	}
19343 	if ((error == 0) && (rack->lt_bw_up == 0)) {
19344 		/* Unlikely */
19345 		rack->r_ctl.lt_timemark = tcp_tv_to_lusectick(tv);
19346 		rack->r_ctl.lt_seq = tp->snd_una;
19347 		rack->lt_bw_up = 1;
19348 	}
19349 	rack_log_output(tp, &to, len, tp->snd_max, flags, error, rack_to_usec_ts(tv),
19350 			NULL, add_flag, s_mb, s_soff, rack->r_ctl.fsb.hw_tls, segsiz);
19351 	m = NULL;
19352 	if (tp->snd_una == tp->snd_max) {
19353 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
19354 		rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
19355 		tp->t_acktime = ticks;
19356 	}
19357 	counter_u64_add(rack_total_bytes, len);
19358 	tcp_account_for_send(tp, len, 0, 0, rack->r_ctl.fsb.hw_tls);
19359 
19360 	rack->forced_ack = 0;	/* If we send something zap the FA flag */
19361 	tot_len += len;
19362 	if ((tp->t_flags & TF_GPUTINPROG) == 0)
19363 		rack_start_gp_measurement(tp, rack, tp->snd_max, sb_offset);
19364 	tp->snd_max += len;
19365 	tp->snd_nxt = tp->snd_max;
19366 	if (rack->rc_new_rnd_needed) {
19367 		/*
19368 		 * Update the rnd to start ticking not
19369 		 * that from a time perspective all of
19370 		 * the preceding idle time is "in the round"
19371 		 */
19372 		rack->rc_new_rnd_needed = 0;
19373 		rack->r_ctl.roundends = tp->snd_max;
19374 	}
19375 	{
19376 		int idx;
19377 
19378 		idx = (len / segsiz) + 3;
19379 		if (idx >= TCP_MSS_ACCT_ATIMER)
19380 			counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
19381 		else
19382 			counter_u64_add(rack_out_size[idx], 1);
19383 	}
19384 	if (len <= rack->r_ctl.fsb.left_to_send)
19385 		rack->r_ctl.fsb.left_to_send -= len;
19386 	else
19387 		rack->r_ctl.fsb.left_to_send = 0;
19388 	if (rack->r_ctl.fsb.left_to_send < segsiz) {
19389 		rack->r_fast_output = 0;
19390 		rack->r_ctl.fsb.left_to_send = 0;
19391 		/* At the end of fast_output scale up the sb */
19392 		SOCKBUF_LOCK(&rack->rc_inp->inp_socket->so_snd);
19393 		rack_sndbuf_autoscale(rack);
19394 		SOCKBUF_UNLOCK(&rack->rc_inp->inp_socket->so_snd);
19395 	}
19396 	if (tp->t_rtttime == 0) {
19397 		tp->t_rtttime = ticks;
19398 		tp->t_rtseq = startseq;
19399 		KMOD_TCPSTAT_INC(tcps_segstimed);
19400 	}
19401 	if ((rack->r_ctl.fsb.left_to_send >= segsiz) &&
19402 	    (max_val > len) &&
19403 	    (tso == 0)) {
19404 		max_val -= len;
19405 		len = segsiz;
19406 		th = rack->r_ctl.fsb.th;
19407 #ifdef TCP_ACCOUNTING
19408 		cnt_thru++;
19409 #endif
19410 		goto again;
19411 	}
19412 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
19413 	counter_u64_add(rack_fto_send, 1);
19414 	slot = rack_get_pacing_delay(rack, tp, tot_len, NULL, segsiz);
19415 	rack_start_hpts_timer(rack, tp, cts, slot, tot_len, 0);
19416 #ifdef TCP_ACCOUNTING
19417 	crtsc = get_cyclecount();
19418 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19419 		tp->tcp_cnt_counters[SND_OUT_DATA] += cnt_thru;
19420 	}
19421 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19422 		tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
19423 	}
19424 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19425 		tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len + segsiz - 1) / segsiz);
19426 	}
19427 	sched_unpin();
19428 #endif
19429 	return (0);
19430 failed:
19431 	if (m)
19432 		m_free(m);
19433 	rack->r_fast_output = 0;
19434 	return (-1);
19435 }
19436 
19437 static inline void
19438 rack_setup_fast_output(struct tcpcb *tp, struct tcp_rack *rack,
19439 		       struct sockbuf *sb,
19440 		       int len, int orig_len, int segsiz, uint32_t pace_max_seg,
19441 		       bool hw_tls,
19442 		       uint16_t flags)
19443 {
19444 	rack->r_fast_output = 1;
19445 	rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
19446 	rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
19447 	rack->r_ctl.fsb.o_t_len = M_TRAILINGROOM(rack->r_ctl.fsb.m);
19448 	rack->r_ctl.fsb.tcp_flags = flags;
19449 	rack->r_ctl.fsb.left_to_send = orig_len - len;
19450 	if (rack->r_ctl.fsb.left_to_send < pace_max_seg) {
19451 		/* Less than a full sized pace, lets not  */
19452 		rack->r_fast_output = 0;
19453 		return;
19454 	} else {
19455 		/* Round down to the nearest pace_max_seg */
19456 		rack->r_ctl.fsb.left_to_send = rounddown(rack->r_ctl.fsb.left_to_send, pace_max_seg);
19457 	}
19458 	if (hw_tls)
19459 		rack->r_ctl.fsb.hw_tls = 1;
19460 	else
19461 		rack->r_ctl.fsb.hw_tls = 0;
19462 	KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
19463 		("rack:%p left_to_send:%u sbavail:%u out:%u",
19464 		 rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
19465 		 (tp->snd_max - tp->snd_una)));
19466 	if (rack->r_ctl.fsb.left_to_send < segsiz)
19467 		rack->r_fast_output = 0;
19468 	else {
19469 		if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
19470 			rack->r_ctl.fsb.rfo_apply_push = 1;
19471 		else
19472 			rack->r_ctl.fsb.rfo_apply_push = 0;
19473 	}
19474 }
19475 
19476 static uint32_t
19477 rack_get_hpts_pacing_min_for_bw(struct tcp_rack *rack, int32_t segsiz)
19478 {
19479 	uint64_t min_time;
19480 	uint32_t maxlen;
19481 
19482 	min_time = (uint64_t)get_hpts_min_sleep_time();
19483 	maxlen = (uint32_t)((rack->r_ctl.gp_bw * min_time) / (uint64_t)HPTS_USEC_IN_SEC);
19484 	maxlen = roundup(maxlen, segsiz);
19485 	return (maxlen);
19486 }
19487 
19488 static struct rack_sendmap *
19489 rack_check_collapsed(struct tcp_rack *rack, uint32_t cts)
19490 {
19491 	struct rack_sendmap *rsm = NULL;
19492 	int thresh;
19493 
19494 restart:
19495 	rsm = tqhash_find(rack->r_ctl.tqh, rack->r_ctl.last_collapse_point);
19496 	if ((rsm == NULL) || ((rsm->r_flags & RACK_RWND_COLLAPSED) == 0)) {
19497 		/* Nothing, strange turn off validity  */
19498 		rack->r_collapse_point_valid = 0;
19499 		return (NULL);
19500 	}
19501 	/* Can we send it yet? */
19502 	if (rsm->r_end > (rack->rc_tp->snd_una + rack->rc_tp->snd_wnd)) {
19503 		/*
19504 		 * Receiver window has not grown enough for
19505 		 * the segment to be put on the wire.
19506 		 */
19507 		return (NULL);
19508 	}
19509 	if (rsm->r_flags & RACK_ACKED) {
19510 		/*
19511 		 * It has been sacked, lets move to the
19512 		 * next one if possible.
19513 		 */
19514 		rack->r_ctl.last_collapse_point = rsm->r_end;
19515 		/* Are we done? */
19516 		if (SEQ_GEQ(rack->r_ctl.last_collapse_point,
19517 			    rack->r_ctl.high_collapse_point)) {
19518 			rack->r_collapse_point_valid = 0;
19519 			return (NULL);
19520 		}
19521 		goto restart;
19522 	}
19523 	/* Now has it been long enough ? */
19524 	thresh = rack_calc_thresh_rack(rack, rack_grab_rtt(rack->rc_tp, rack), cts);
19525 	if ((cts - ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)])) > thresh) {
19526 		rack_log_collapse(rack, rsm->r_start,
19527 				  (cts - ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)])),
19528 				  thresh, __LINE__, 6, rsm->r_flags, rsm);
19529 		return (rsm);
19530 	}
19531 	/* Not enough time */
19532 	rack_log_collapse(rack, rsm->r_start,
19533 			  (cts - ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)])),
19534 			  thresh, __LINE__, 7, rsm->r_flags, rsm);
19535 	return (NULL);
19536 }
19537 
19538 static inline void
19539 rack_validate_sizes(struct tcp_rack *rack, int32_t *len, int32_t segsiz, uint32_t pace_max_seg)
19540 {
19541 	if ((rack->full_size_rxt == 0) &&
19542 	    (rack->shape_rxt_to_pacing_min == 0) &&
19543 	    (*len >= segsiz)) {
19544 		*len = segsiz;
19545 	} else if (rack->shape_rxt_to_pacing_min &&
19546 		 rack->gp_ready) {
19547 		/* We use pacing min as shaping len req */
19548 		uint32_t maxlen;
19549 
19550 		maxlen = rack_get_hpts_pacing_min_for_bw(rack, segsiz);
19551 		if (*len > maxlen)
19552 			*len = maxlen;
19553 	} else {
19554 		/*
19555 		 * The else is full_size_rxt is on so send it all
19556 		 * note we do need to check this for exceeding
19557 		 * our max segment size due to the fact that
19558 		 * we do sometimes merge chunks together i.e.
19559 		 * we cannot just assume that we will never have
19560 		 * a chunk greater than pace_max_seg
19561 		 */
19562 		if (*len > pace_max_seg)
19563 			*len = pace_max_seg;
19564 	}
19565 }
19566 
19567 static int
19568 rack_output(struct tcpcb *tp)
19569 {
19570 	struct socket *so;
19571 	uint32_t recwin;
19572 	uint32_t sb_offset, s_moff = 0;
19573 	int32_t len, error = 0;
19574 	uint16_t flags;
19575 	struct mbuf *m, *s_mb = NULL;
19576 	struct mbuf *mb;
19577 	uint32_t if_hw_tsomaxsegcount = 0;
19578 	uint32_t if_hw_tsomaxsegsize;
19579 	int32_t segsiz, minseg;
19580 	long tot_len_this_send = 0;
19581 #ifdef INET
19582 	struct ip *ip = NULL;
19583 #endif
19584 	struct udphdr *udp = NULL;
19585 	struct tcp_rack *rack;
19586 	struct tcphdr *th;
19587 	uint8_t pass = 0;
19588 	uint8_t mark = 0;
19589 	uint8_t check_done = 0;
19590 	uint8_t wanted_cookie = 0;
19591 	u_char opt[TCP_MAXOLEN];
19592 	unsigned ipoptlen, optlen, hdrlen, ulen=0;
19593 	uint32_t rack_seq;
19594 
19595 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
19596 	unsigned ipsec_optlen = 0;
19597 
19598 #endif
19599 	int32_t idle, sendalot;
19600 	int32_t sub_from_prr = 0;
19601 	volatile int32_t sack_rxmit;
19602 	struct rack_sendmap *rsm = NULL;
19603 	int32_t tso, mtu;
19604 	struct tcpopt to;
19605 	int32_t slot = 0;
19606 	int32_t sup_rack = 0;
19607 	uint32_t cts, ms_cts, delayed, early;
19608 	uint16_t add_flag = RACK_SENT_SP;
19609 	/* The doing_tlp flag will be set by the actual rack_timeout_tlp() */
19610 	uint8_t hpts_calling,  doing_tlp = 0;
19611 	uint32_t cwnd_to_use, pace_max_seg;
19612 	int32_t do_a_prefetch = 0;
19613 	int32_t prefetch_rsm = 0;
19614 	int32_t orig_len = 0;
19615 	struct timeval tv;
19616 	int32_t prefetch_so_done = 0;
19617 	struct tcp_log_buffer *lgb;
19618 	struct inpcb *inp = tptoinpcb(tp);
19619 	struct sockbuf *sb;
19620 	uint64_t ts_val = 0;
19621 #ifdef TCP_ACCOUNTING
19622 	uint64_t crtsc;
19623 #endif
19624 #ifdef INET6
19625 	struct ip6_hdr *ip6 = NULL;
19626 	int32_t isipv6;
19627 #endif
19628 	bool hw_tls = false;
19629 
19630 	NET_EPOCH_ASSERT();
19631 	INP_WLOCK_ASSERT(inp);
19632 
19633 	/* setup and take the cache hits here */
19634 	rack = (struct tcp_rack *)tp->t_fb_ptr;
19635 #ifdef TCP_ACCOUNTING
19636 	sched_pin();
19637 	ts_val = get_cyclecount();
19638 #endif
19639 	hpts_calling = inp->inp_hpts_calls;
19640 #ifdef TCP_OFFLOAD
19641 	if (tp->t_flags & TF_TOE) {
19642 #ifdef TCP_ACCOUNTING
19643 		sched_unpin();
19644 #endif
19645 		return (tcp_offload_output(tp));
19646 	}
19647 #endif
19648 	if (rack->rack_deferred_inited == 0) {
19649 		/*
19650 		 * If we are the connecting socket we will
19651 		 * hit rack_init() when no sequence numbers
19652 		 * are setup. This makes it so we must defer
19653 		 * some initialization. Call that now.
19654 		 */
19655 		rack_deferred_init(tp, rack);
19656 	}
19657 	/*
19658 	 * For TFO connections in SYN_RECEIVED, only allow the initial
19659 	 * SYN|ACK and those sent by the retransmit timer.
19660 	 */
19661 	if (IS_FASTOPEN(tp->t_flags) &&
19662 	    (tp->t_state == TCPS_SYN_RECEIVED) &&
19663 	    SEQ_GT(tp->snd_max, tp->snd_una) &&    /* initial SYN|ACK sent */
19664 	    (rack->r_ctl.rc_resend == NULL)) {         /* not a retransmit */
19665 #ifdef TCP_ACCOUNTING
19666 		sched_unpin();
19667 #endif
19668 		return (0);
19669 	}
19670 #ifdef INET6
19671 	if (rack->r_state) {
19672 		/* Use the cache line loaded if possible */
19673 		isipv6 = rack->r_is_v6;
19674 	} else {
19675 		isipv6 = (rack->rc_inp->inp_vflag & INP_IPV6) != 0;
19676 	}
19677 #endif
19678 	early = 0;
19679 	cts = tcp_get_usecs(&tv);
19680 	ms_cts = tcp_tv_to_mssectick(&tv);
19681 	if (((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) &&
19682 	    tcp_in_hpts(rack->rc_inp)) {
19683 		/*
19684 		 * We are on the hpts for some timer but not hptsi output.
19685 		 * Remove from the hpts unconditionally.
19686 		 */
19687 		rack_timer_cancel(tp, rack, cts, __LINE__);
19688 	}
19689 	/* Are we pacing and late? */
19690 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
19691 	    TSTMP_GEQ(cts, rack->r_ctl.rc_last_output_to)) {
19692 		/* We are delayed */
19693 		delayed = cts - rack->r_ctl.rc_last_output_to;
19694 	} else {
19695 		delayed = 0;
19696 	}
19697 	/* Do the timers, which may override the pacer */
19698 	if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
19699 		int retval;
19700 
19701 		retval = rack_process_timers(tp, rack, cts, hpts_calling,
19702 					     &doing_tlp);
19703 		if (retval != 0) {
19704 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_ATIMER], 1);
19705 #ifdef TCP_ACCOUNTING
19706 			sched_unpin();
19707 #endif
19708 			/*
19709 			 * If timers want tcp_drop(), then pass error out,
19710 			 * otherwise suppress it.
19711 			 */
19712 			return (retval < 0 ? retval : 0);
19713 		}
19714 	}
19715 	if (rack->rc_in_persist) {
19716 		if (tcp_in_hpts(rack->rc_inp) == 0) {
19717 			/* Timer is not running */
19718 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
19719 		}
19720 #ifdef TCP_ACCOUNTING
19721 		sched_unpin();
19722 #endif
19723 		return (0);
19724 	}
19725 	if ((rack->rc_ack_required == 1) &&
19726 	    (rack->r_timer_override == 0)){
19727 		/* A timeout occurred and no ack has arrived */
19728 		if (tcp_in_hpts(rack->rc_inp) == 0) {
19729 			/* Timer is not running */
19730 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
19731 		}
19732 #ifdef TCP_ACCOUNTING
19733 		sched_unpin();
19734 #endif
19735 		return (0);
19736 	}
19737 	if ((rack->r_timer_override) ||
19738 	    (rack->rc_ack_can_sendout_data) ||
19739 	    (delayed) ||
19740 	    (tp->t_state < TCPS_ESTABLISHED)) {
19741 		rack->rc_ack_can_sendout_data = 0;
19742 		if (tcp_in_hpts(rack->rc_inp))
19743 			tcp_hpts_remove(rack->rc_inp);
19744 	} else if (tcp_in_hpts(rack->rc_inp)) {
19745 		/*
19746 		 * On the hpts you can't pass even if ACKNOW is on, we will
19747 		 * when the hpts fires.
19748 		 */
19749 #ifdef TCP_ACCOUNTING
19750 		crtsc = get_cyclecount();
19751 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19752 			tp->tcp_proc_time[SND_BLOCKED] += (crtsc - ts_val);
19753 		}
19754 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19755 			tp->tcp_cnt_counters[SND_BLOCKED]++;
19756 		}
19757 		sched_unpin();
19758 #endif
19759 		counter_u64_add(rack_out_size[TCP_MSS_ACCT_INPACE], 1);
19760 		return (0);
19761 	}
19762 	rack->rc_inp->inp_hpts_calls = 0;
19763 	/* Finish out both pacing early and late accounting */
19764 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
19765 	    TSTMP_GT(rack->r_ctl.rc_last_output_to, cts)) {
19766 		early = rack->r_ctl.rc_last_output_to - cts;
19767 	} else
19768 		early = 0;
19769 	if (delayed) {
19770 		rack->r_ctl.rc_agg_delayed += delayed;
19771 		rack->r_late = 1;
19772 	} else if (early) {
19773 		rack->r_ctl.rc_agg_early += early;
19774 		rack->r_early = 1;
19775 	}
19776 	/* Now that early/late accounting is done turn off the flag */
19777 	rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
19778 	rack->r_wanted_output = 0;
19779 	rack->r_timer_override = 0;
19780 	if ((tp->t_state != rack->r_state) &&
19781 	    TCPS_HAVEESTABLISHED(tp->t_state)) {
19782 		rack_set_state(tp, rack);
19783 	}
19784 	if ((rack->r_fast_output) &&
19785 	    (doing_tlp == 0) &&
19786 	    (tp->rcv_numsacks == 0)) {
19787 		int ret;
19788 
19789 		error = 0;
19790 		ret = rack_fast_output(tp, rack, ts_val, cts, ms_cts, &tv, tot_len_this_send, &error);
19791 		if (ret >= 0)
19792 			return(ret);
19793 		else if (error) {
19794 			inp = rack->rc_inp;
19795 			so = inp->inp_socket;
19796 			sb = &so->so_snd;
19797 			goto nomore;
19798 		}
19799 	}
19800 	inp = rack->rc_inp;
19801 	/*
19802 	 * For TFO connections in SYN_SENT or SYN_RECEIVED,
19803 	 * only allow the initial SYN or SYN|ACK and those sent
19804 	 * by the retransmit timer.
19805 	 */
19806 	if (IS_FASTOPEN(tp->t_flags) &&
19807 	    ((tp->t_state == TCPS_SYN_RECEIVED) ||
19808 	     (tp->t_state == TCPS_SYN_SENT)) &&
19809 	    SEQ_GT(tp->snd_max, tp->snd_una) && /* initial SYN or SYN|ACK sent */
19810 	    (tp->t_rxtshift == 0)) {              /* not a retransmit */
19811 		cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
19812 		so = inp->inp_socket;
19813 		sb = &so->so_snd;
19814 		goto just_return_nolock;
19815 	}
19816 	/*
19817 	 * Determine length of data that should be transmitted, and flags
19818 	 * that will be used. If there is some data or critical controls
19819 	 * (SYN, RST) to send, then transmit; otherwise, investigate
19820 	 * further.
19821 	 */
19822 	idle = (tp->t_flags & TF_LASTIDLE) || (tp->snd_max == tp->snd_una);
19823 	if (tp->t_idle_reduce) {
19824 		if (idle && (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur))
19825 			rack_cc_after_idle(rack, tp);
19826 	}
19827 	tp->t_flags &= ~TF_LASTIDLE;
19828 	if (idle) {
19829 		if (tp->t_flags & TF_MORETOCOME) {
19830 			tp->t_flags |= TF_LASTIDLE;
19831 			idle = 0;
19832 		}
19833 	}
19834 	if ((tp->snd_una == tp->snd_max) &&
19835 	    rack->r_ctl.rc_went_idle_time &&
19836 	    TSTMP_GT(cts, rack->r_ctl.rc_went_idle_time)) {
19837 		idle = cts - rack->r_ctl.rc_went_idle_time;
19838 		if (idle > rack_min_probertt_hold) {
19839 			/* Count as a probe rtt */
19840 			if (rack->in_probe_rtt == 0) {
19841 				rack->r_ctl.rc_lower_rtt_us_cts = cts;
19842 				rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
19843 				rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
19844 				rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
19845 			} else {
19846 				rack_exit_probertt(rack, cts);
19847 			}
19848 		}
19849 		idle = 0;
19850 	}
19851 	if (rack_use_fsb &&
19852 	    (rack->r_ctl.fsb.tcp_ip_hdr) &&
19853 	    (rack->r_fsb_inited == 0) &&
19854 	    (rack->r_state != TCPS_CLOSED))
19855 		rack_init_fsb_block(tp, rack, tcp_outflags[tp->t_state]);
19856 again:
19857 	/*
19858 	 * If we've recently taken a timeout, snd_max will be greater than
19859 	 * snd_nxt.  There may be SACK information that allows us to avoid
19860 	 * resending already delivered data.  Adjust snd_nxt accordingly.
19861 	 */
19862 	sendalot = 0;
19863 	cts = tcp_get_usecs(&tv);
19864 	ms_cts = tcp_tv_to_mssectick(&tv);
19865 	tso = 0;
19866 	mtu = 0;
19867 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
19868 	minseg = segsiz;
19869 	if (rack->r_ctl.rc_pace_max_segs == 0)
19870 		pace_max_seg = rack->rc_user_set_max_segs * segsiz;
19871 	else
19872 		pace_max_seg = rack->r_ctl.rc_pace_max_segs;
19873 	sb_offset = tp->snd_max - tp->snd_una;
19874 	cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
19875 	flags = tcp_outflags[tp->t_state];
19876 	while (rack->rc_free_cnt < rack_free_cache) {
19877 		rsm = rack_alloc(rack);
19878 		if (rsm == NULL) {
19879 			if (inp->inp_hpts_calls)
19880 				/* Retry in a ms */
19881 				slot = (1 * HPTS_USEC_IN_MSEC);
19882 			so = inp->inp_socket;
19883 			sb = &so->so_snd;
19884 			goto just_return_nolock;
19885 		}
19886 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_free, rsm, r_tnext);
19887 		rack->rc_free_cnt++;
19888 		rsm = NULL;
19889 	}
19890 	if (inp->inp_hpts_calls)
19891 		inp->inp_hpts_calls = 0;
19892 	sack_rxmit = 0;
19893 	len = 0;
19894 	rsm = NULL;
19895 	if (flags & TH_RST) {
19896 		SOCKBUF_LOCK(&inp->inp_socket->so_snd);
19897 		so = inp->inp_socket;
19898 		sb = &so->so_snd;
19899 		goto send;
19900 	}
19901 	if (rack->r_ctl.rc_resend) {
19902 		/* Retransmit timer */
19903 		rsm = rack->r_ctl.rc_resend;
19904 		rack->r_ctl.rc_resend = NULL;
19905 		len = rsm->r_end - rsm->r_start;
19906 		sack_rxmit = 1;
19907 		sendalot = 0;
19908 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
19909 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
19910 			 __func__, __LINE__,
19911 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
19912 		sb_offset = rsm->r_start - tp->snd_una;
19913 		rack_validate_sizes(rack, &len, segsiz, pace_max_seg);
19914 	} else if (rack->r_collapse_point_valid &&
19915 		   ((rsm = rack_check_collapsed(rack, cts)) != NULL)) {
19916 		/*
19917 		 * If an RSM is returned then enough time has passed
19918 		 * for us to retransmit it. Move up the collapse point,
19919 		 * since this rsm has its chance to retransmit now.
19920 		 */
19921 		tcp_trace_point(rack->rc_tp, TCP_TP_COLLAPSED_RXT);
19922 		rack->r_ctl.last_collapse_point = rsm->r_end;
19923 		/* Are we done? */
19924 		if (SEQ_GEQ(rack->r_ctl.last_collapse_point,
19925 			    rack->r_ctl.high_collapse_point))
19926 			rack->r_collapse_point_valid = 0;
19927 		sack_rxmit = 1;
19928 		/* We are not doing a TLP */
19929 		doing_tlp = 0;
19930 		len = rsm->r_end - rsm->r_start;
19931 		sb_offset = rsm->r_start - tp->snd_una;
19932 		sendalot = 0;
19933 		rack_validate_sizes(rack, &len, segsiz, pace_max_seg);
19934 	} else if ((rsm = tcp_rack_output(tp, rack, cts)) != NULL) {
19935 		/* We have a retransmit that takes precedence */
19936 		if ((!IN_FASTRECOVERY(tp->t_flags)) &&
19937 		    ((rsm->r_flags & RACK_MUST_RXT) == 0) &&
19938 		    ((tp->t_flags & TF_WASFRECOVERY) == 0)) {
19939 			/* Enter recovery if not induced by a time-out */
19940 			rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
19941 		}
19942 #ifdef INVARIANTS
19943 		if (SEQ_LT(rsm->r_start, tp->snd_una)) {
19944 			panic("Huh, tp:%p rack:%p rsm:%p start:%u < snd_una:%u\n",
19945 			      tp, rack, rsm, rsm->r_start, tp->snd_una);
19946 		}
19947 #endif
19948 		len = rsm->r_end - rsm->r_start;
19949 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
19950 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
19951 			 __func__, __LINE__,
19952 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
19953 		sb_offset = rsm->r_start - tp->snd_una;
19954 		sendalot = 0;
19955 		rack_validate_sizes(rack, &len, segsiz, pace_max_seg);
19956 		if (len > 0) {
19957 			sack_rxmit = 1;
19958 			KMOD_TCPSTAT_INC(tcps_sack_rexmits);
19959 			KMOD_TCPSTAT_ADD(tcps_sack_rexmit_bytes,
19960 					 min(len, segsiz));
19961 		}
19962 	} else if (rack->r_ctl.rc_tlpsend) {
19963 		/* Tail loss probe */
19964 		long cwin;
19965 		long tlen;
19966 
19967 		/*
19968 		 * Check if we can do a TLP with a RACK'd packet
19969 		 * this can happen if we are not doing the rack
19970 		 * cheat and we skipped to a TLP and it
19971 		 * went off.
19972 		 */
19973 		rsm = rack->r_ctl.rc_tlpsend;
19974 		/* We are doing a TLP make sure the flag is preent */
19975 		rsm->r_flags |= RACK_TLP;
19976 		rack->r_ctl.rc_tlpsend = NULL;
19977 		sack_rxmit = 1;
19978 		tlen = rsm->r_end - rsm->r_start;
19979 		if (tlen > segsiz)
19980 			tlen = segsiz;
19981 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
19982 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
19983 			 __func__, __LINE__,
19984 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
19985 		sb_offset = rsm->r_start - tp->snd_una;
19986 		cwin = min(tp->snd_wnd, tlen);
19987 		len = cwin;
19988 	}
19989 	if (rack->r_must_retran &&
19990 	    (doing_tlp == 0) &&
19991 	    (SEQ_GT(tp->snd_max, tp->snd_una)) &&
19992 	    (rsm == NULL)) {
19993 		/*
19994 		 * There are two different ways that we
19995 		 * can get into this block:
19996 		 * a) This is a non-sack connection, we had a time-out
19997 		 *    and thus r_must_retran was set and everything
19998 		 *    left outstanding as been marked for retransmit.
19999 		 * b) The MTU of the path shrank, so that everything
20000 		 *    was marked to be retransmitted with the smaller
20001 		 *    mtu and r_must_retran was set.
20002 		 *
20003 		 * This means that we expect the sendmap (outstanding)
20004 		 * to all be marked must. We can use the tmap to
20005 		 * look at them.
20006 		 *
20007 		 */
20008 		int sendwin, flight;
20009 
20010 		sendwin = min(tp->snd_wnd, tp->snd_cwnd);
20011 		flight = ctf_flight_size(tp, rack->r_ctl.rc_out_at_rto);
20012 		if (flight >= sendwin) {
20013 			/*
20014 			 * We can't send yet.
20015 			 */
20016 			so = inp->inp_socket;
20017 			sb = &so->so_snd;
20018 			goto just_return_nolock;
20019 		}
20020 		/*
20021 		 * This is the case a/b mentioned above. All
20022 		 * outstanding/not-acked should be marked.
20023 		 * We can use the tmap to find them.
20024 		 */
20025 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
20026 		if (rsm == NULL) {
20027 			/* TSNH */
20028 			rack->r_must_retran = 0;
20029 			rack->r_ctl.rc_out_at_rto = 0;
20030 			so = inp->inp_socket;
20031 			sb = &so->so_snd;
20032 			goto just_return_nolock;
20033 		}
20034 		if ((rsm->r_flags & RACK_MUST_RXT) == 0) {
20035 			/*
20036 			 * The first one does not have the flag, did we collapse
20037 			 * further up in our list?
20038 			 */
20039 			rack->r_must_retran = 0;
20040 			rack->r_ctl.rc_out_at_rto = 0;
20041 			rsm = NULL;
20042 			sack_rxmit = 0;
20043 		} else {
20044 			sack_rxmit = 1;
20045 			len = rsm->r_end - rsm->r_start;
20046 			sb_offset = rsm->r_start - tp->snd_una;
20047 			sendalot = 0;
20048 			if ((rack->full_size_rxt == 0) &&
20049 			    (rack->shape_rxt_to_pacing_min == 0) &&
20050 			    (len >= segsiz))
20051 				len = segsiz;
20052 			else if (rack->shape_rxt_to_pacing_min &&
20053 				 rack->gp_ready) {
20054 				/* We use pacing min as shaping len req */
20055 				uint32_t maxlen;
20056 
20057 				maxlen = rack_get_hpts_pacing_min_for_bw(rack, segsiz);
20058 				if (len > maxlen)
20059 					len = maxlen;
20060 			}
20061 			/*
20062 			 * Delay removing the flag RACK_MUST_RXT so
20063 			 * that the fastpath for retransmit will
20064 			 * work with this rsm.
20065 			 */
20066 		}
20067 	}
20068 	/*
20069 	 * Enforce a connection sendmap count limit if set
20070 	 * as long as we are not retransmiting.
20071 	 */
20072 	if ((rsm == NULL) &&
20073 	    (rack->do_detection == 0) &&
20074 	    (V_tcp_map_entries_limit > 0) &&
20075 	    (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
20076 		counter_u64_add(rack_to_alloc_limited, 1);
20077 		if (!rack->alloc_limit_reported) {
20078 			rack->alloc_limit_reported = 1;
20079 			counter_u64_add(rack_alloc_limited_conns, 1);
20080 		}
20081 		so = inp->inp_socket;
20082 		sb = &so->so_snd;
20083 		goto just_return_nolock;
20084 	}
20085 	if (rsm && (rsm->r_flags & RACK_HAS_FIN)) {
20086 		/* we are retransmitting the fin */
20087 		len--;
20088 		if (len) {
20089 			/*
20090 			 * When retransmitting data do *not* include the
20091 			 * FIN. This could happen from a TLP probe.
20092 			 */
20093 			flags &= ~TH_FIN;
20094 		}
20095 	}
20096 	if (rsm && rack->r_fsb_inited &&
20097 	    rack_use_rsm_rfo &&
20098 	    ((rsm->r_flags & RACK_HAS_FIN) == 0)) {
20099 		int ret;
20100 
20101 		ret = rack_fast_rsm_output(tp, rack, rsm, ts_val, cts, ms_cts, &tv, len, doing_tlp);
20102 		if (ret == 0)
20103 			return (0);
20104 	}
20105 	so = inp->inp_socket;
20106 	sb = &so->so_snd;
20107 	if (do_a_prefetch == 0) {
20108 		kern_prefetch(sb, &do_a_prefetch);
20109 		do_a_prefetch = 1;
20110 	}
20111 #ifdef NETFLIX_SHARED_CWND
20112 	if ((tp->t_flags2 & TF2_TCP_SCWND_ALLOWED) &&
20113 	    rack->rack_enable_scwnd) {
20114 		/* We are doing cwnd sharing */
20115 		if (rack->gp_ready &&
20116 		    (rack->rack_attempted_scwnd == 0) &&
20117 		    (rack->r_ctl.rc_scw == NULL) &&
20118 		    tp->t_lib) {
20119 			/* The pcbid is in, lets make an attempt */
20120 			counter_u64_add(rack_try_scwnd, 1);
20121 			rack->rack_attempted_scwnd = 1;
20122 			rack->r_ctl.rc_scw = tcp_shared_cwnd_alloc(tp,
20123 								   &rack->r_ctl.rc_scw_index,
20124 								   segsiz);
20125 		}
20126 		if (rack->r_ctl.rc_scw &&
20127 		    (rack->rack_scwnd_is_idle == 1) &&
20128 		    sbavail(&so->so_snd)) {
20129 			/* we are no longer out of data */
20130 			tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
20131 			rack->rack_scwnd_is_idle = 0;
20132 		}
20133 		if (rack->r_ctl.rc_scw) {
20134 			/* First lets update and get the cwnd */
20135 			rack->r_ctl.cwnd_to_use = cwnd_to_use = tcp_shared_cwnd_update(rack->r_ctl.rc_scw,
20136 										       rack->r_ctl.rc_scw_index,
20137 										       tp->snd_cwnd, tp->snd_wnd, segsiz);
20138 		}
20139 	}
20140 #endif
20141 	/*
20142 	 * Get standard flags, and add SYN or FIN if requested by 'hidden'
20143 	 * state flags.
20144 	 */
20145 	if (tp->t_flags & TF_NEEDFIN)
20146 		flags |= TH_FIN;
20147 	if (tp->t_flags & TF_NEEDSYN)
20148 		flags |= TH_SYN;
20149 	if ((sack_rxmit == 0) && (prefetch_rsm == 0)) {
20150 		void *end_rsm;
20151 		end_rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
20152 		if (end_rsm)
20153 			kern_prefetch(end_rsm, &prefetch_rsm);
20154 		prefetch_rsm = 1;
20155 	}
20156 	SOCKBUF_LOCK(sb);
20157 	/*
20158 	 * If snd_nxt == snd_max and we have transmitted a FIN, the
20159 	 * sb_offset will be > 0 even if so_snd.sb_cc is 0, resulting in a
20160 	 * negative length.  This can also occur when TCP opens up its
20161 	 * congestion window while receiving additional duplicate acks after
20162 	 * fast-retransmit because TCP will reset snd_nxt to snd_max after
20163 	 * the fast-retransmit.
20164 	 *
20165 	 * In the normal retransmit-FIN-only case, however, snd_nxt will be
20166 	 * set to snd_una, the sb_offset will be 0, and the length may wind
20167 	 * up 0.
20168 	 *
20169 	 * If sack_rxmit is true we are retransmitting from the scoreboard
20170 	 * in which case len is already set.
20171 	 */
20172 	if ((sack_rxmit == 0) &&
20173 	    (TCPS_HAVEESTABLISHED(tp->t_state) || IS_FASTOPEN(tp->t_flags))) {
20174 		uint32_t avail;
20175 
20176 		avail = sbavail(sb);
20177 		if (SEQ_GT(tp->snd_nxt, tp->snd_una) && avail)
20178 			sb_offset = tp->snd_nxt - tp->snd_una;
20179 		else
20180 			sb_offset = 0;
20181 		if ((IN_FASTRECOVERY(tp->t_flags) == 0) || rack->rack_no_prr) {
20182 			if (rack->r_ctl.rc_tlp_new_data) {
20183 				/* TLP is forcing out new data */
20184 				if (rack->r_ctl.rc_tlp_new_data > (uint32_t) (avail - sb_offset)) {
20185 					rack->r_ctl.rc_tlp_new_data = (uint32_t) (avail - sb_offset);
20186 				}
20187 				if ((rack->r_ctl.rc_tlp_new_data + sb_offset) > tp->snd_wnd) {
20188 					if (tp->snd_wnd > sb_offset)
20189 						len = tp->snd_wnd - sb_offset;
20190 					else
20191 						len = 0;
20192 				} else {
20193 					len = rack->r_ctl.rc_tlp_new_data;
20194 				}
20195 				rack->r_ctl.rc_tlp_new_data = 0;
20196 			}  else {
20197 				len = rack_what_can_we_send(tp, rack, cwnd_to_use, avail, sb_offset);
20198 			}
20199 			if ((rack->r_ctl.crte == NULL) &&
20200 			    IN_FASTRECOVERY(tp->t_flags) &&
20201 			    (rack->full_size_rxt == 0) &&
20202 			    (rack->shape_rxt_to_pacing_min == 0) &&
20203 			    (len > segsiz)) {
20204 				/*
20205 				 * For prr=off, we need to send only 1 MSS
20206 				 * at a time. We do this because another sack could
20207 				 * be arriving that causes us to send retransmits and
20208 				 * we don't want to be on a long pace due to a larger send
20209 				 * that keeps us from sending out the retransmit.
20210 				 */
20211 				len = segsiz;
20212 			} else if (rack->shape_rxt_to_pacing_min &&
20213 				   rack->gp_ready) {
20214 				/* We use pacing min as shaping len req */
20215 				uint32_t maxlen;
20216 
20217 				maxlen = rack_get_hpts_pacing_min_for_bw(rack, segsiz);
20218 				if (len > maxlen)
20219 					len = maxlen;
20220 			}/* The else is full_size_rxt is on so send it all */
20221 		} else {
20222 			uint32_t outstanding;
20223 			/*
20224 			 * We are inside of a Fast recovery episode, this
20225 			 * is caused by a SACK or 3 dup acks. At this point
20226 			 * we have sent all the retransmissions and we rely
20227 			 * on PRR to dictate what we will send in the form of
20228 			 * new data.
20229 			 */
20230 
20231 			outstanding = tp->snd_max - tp->snd_una;
20232 			if ((rack->r_ctl.rc_prr_sndcnt + outstanding) > tp->snd_wnd) {
20233 				if (tp->snd_wnd > outstanding) {
20234 					len = tp->snd_wnd - outstanding;
20235 					/* Check to see if we have the data */
20236 					if ((sb_offset + len) > avail) {
20237 						/* It does not all fit */
20238 						if (avail > sb_offset)
20239 							len = avail - sb_offset;
20240 						else
20241 							len = 0;
20242 					}
20243 				} else {
20244 					len = 0;
20245 				}
20246 			} else if (avail > sb_offset) {
20247 				len = avail - sb_offset;
20248 			} else {
20249 				len = 0;
20250 			}
20251 			if (len > 0) {
20252 				if (len > rack->r_ctl.rc_prr_sndcnt) {
20253 					len = rack->r_ctl.rc_prr_sndcnt;
20254 				}
20255 				if (len > 0) {
20256 					sub_from_prr = 1;
20257 				}
20258 			}
20259 			if (len > segsiz) {
20260 				/*
20261 				 * We should never send more than a MSS when
20262 				 * retransmitting or sending new data in prr
20263 				 * mode unless the override flag is on. Most
20264 				 * likely the PRR algorithm is not going to
20265 				 * let us send a lot as well :-)
20266 				 */
20267 				if (rack->r_ctl.rc_prr_sendalot == 0) {
20268 					len = segsiz;
20269 				}
20270 			} else if (len < segsiz) {
20271 				/*
20272 				 * Do we send any? The idea here is if the
20273 				 * send empty's the socket buffer we want to
20274 				 * do it. However if not then lets just wait
20275 				 * for our prr_sndcnt to get bigger.
20276 				 */
20277 				long leftinsb;
20278 
20279 				leftinsb = sbavail(sb) - sb_offset;
20280 				if (leftinsb > len) {
20281 					/* This send does not empty the sb */
20282 					len = 0;
20283 				}
20284 			}
20285 		}
20286 	} else if (!TCPS_HAVEESTABLISHED(tp->t_state)) {
20287 		/*
20288 		 * If you have not established
20289 		 * and are not doing FAST OPEN
20290 		 * no data please.
20291 		 */
20292 		if ((sack_rxmit == 0) &&
20293 		    (!IS_FASTOPEN(tp->t_flags))){
20294 			len = 0;
20295 			sb_offset = 0;
20296 		}
20297 	}
20298 	if (prefetch_so_done == 0) {
20299 		kern_prefetch(so, &prefetch_so_done);
20300 		prefetch_so_done = 1;
20301 	}
20302 	/*
20303 	 * Lop off SYN bit if it has already been sent.  However, if this is
20304 	 * SYN-SENT state and if segment contains data and if we don't know
20305 	 * that foreign host supports TAO, suppress sending segment.
20306 	 */
20307 	if ((flags & TH_SYN) && SEQ_GT(tp->snd_nxt, tp->snd_una) &&
20308 	    ((sack_rxmit == 0) && (tp->t_rxtshift == 0))) {
20309 		/*
20310 		 * When sending additional segments following a TFO SYN|ACK,
20311 		 * do not include the SYN bit.
20312 		 */
20313 		if (IS_FASTOPEN(tp->t_flags) &&
20314 		    (tp->t_state == TCPS_SYN_RECEIVED))
20315 			flags &= ~TH_SYN;
20316 	}
20317 	/*
20318 	 * Be careful not to send data and/or FIN on SYN segments. This
20319 	 * measure is needed to prevent interoperability problems with not
20320 	 * fully conformant TCP implementations.
20321 	 */
20322 	if ((flags & TH_SYN) && (tp->t_flags & TF_NOOPT)) {
20323 		len = 0;
20324 		flags &= ~TH_FIN;
20325 	}
20326 	/*
20327 	 * On TFO sockets, ensure no data is sent in the following cases:
20328 	 *
20329 	 *  - When retransmitting SYN|ACK on a passively-created socket
20330 	 *
20331 	 *  - When retransmitting SYN on an actively created socket
20332 	 *
20333 	 *  - When sending a zero-length cookie (cookie request) on an
20334 	 *    actively created socket
20335 	 *
20336 	 *  - When the socket is in the CLOSED state (RST is being sent)
20337 	 */
20338 	if (IS_FASTOPEN(tp->t_flags) &&
20339 	    (((flags & TH_SYN) && (tp->t_rxtshift > 0)) ||
20340 	     ((tp->t_state == TCPS_SYN_SENT) &&
20341 	      (tp->t_tfo_client_cookie_len == 0)) ||
20342 	     (flags & TH_RST))) {
20343 		sack_rxmit = 0;
20344 		len = 0;
20345 	}
20346 	/* Without fast-open there should never be data sent on a SYN */
20347 	if ((flags & TH_SYN) && (!IS_FASTOPEN(tp->t_flags))) {
20348 		tp->snd_nxt = tp->iss;
20349 		len = 0;
20350 	}
20351 	if ((len > segsiz) && (tcp_dsack_block_exists(tp))) {
20352 		/* We only send 1 MSS if we have a DSACK block */
20353 		add_flag |= RACK_SENT_W_DSACK;
20354 		len = segsiz;
20355 	}
20356 	orig_len = len;
20357 	if (len <= 0) {
20358 		/*
20359 		 * If FIN has been sent but not acked, but we haven't been
20360 		 * called to retransmit, len will be < 0.  Otherwise, window
20361 		 * shrank after we sent into it.  If window shrank to 0,
20362 		 * cancel pending retransmit, pull snd_nxt back to (closed)
20363 		 * window, and set the persist timer if it isn't already
20364 		 * going.  If the window didn't close completely, just wait
20365 		 * for an ACK.
20366 		 *
20367 		 * We also do a general check here to ensure that we will
20368 		 * set the persist timer when we have data to send, but a
20369 		 * 0-byte window. This makes sure the persist timer is set
20370 		 * even if the packet hits one of the "goto send" lines
20371 		 * below.
20372 		 */
20373 		len = 0;
20374 		if ((tp->snd_wnd == 0) &&
20375 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
20376 		    (tp->snd_una == tp->snd_max) &&
20377 		    (sb_offset < (int)sbavail(sb))) {
20378 			rack_enter_persist(tp, rack, cts, tp->snd_una);
20379 		}
20380 	} else if ((rsm == NULL) &&
20381 		   (doing_tlp == 0) &&
20382 		   (len < pace_max_seg)) {
20383 		/*
20384 		 * We are not sending a maximum sized segment for
20385 		 * some reason. Should we not send anything (think
20386 		 * sws or persists)?
20387 		 */
20388 		if ((tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
20389 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
20390 		    (len < minseg) &&
20391 		    (len < (int)(sbavail(sb) - sb_offset))) {
20392 			/*
20393 			 * Here the rwnd is less than
20394 			 * the minimum pacing size, this is not a retransmit,
20395 			 * we are established and
20396 			 * the send is not the last in the socket buffer
20397 			 * we send nothing, and we may enter persists
20398 			 * if nothing is outstanding.
20399 			 */
20400 			len = 0;
20401 			if (tp->snd_max == tp->snd_una) {
20402 				/*
20403 				 * Nothing out we can
20404 				 * go into persists.
20405 				 */
20406 				rack_enter_persist(tp, rack, cts, tp->snd_una);
20407 			}
20408 		} else if ((cwnd_to_use >= max(minseg, (segsiz * 4))) &&
20409 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
20410 			   (len < (int)(sbavail(sb) - sb_offset)) &&
20411 			   (len < minseg)) {
20412 			/*
20413 			 * Here we are not retransmitting, and
20414 			 * the cwnd is not so small that we could
20415 			 * not send at least a min size (rxt timer
20416 			 * not having gone off), We have 2 segments or
20417 			 * more already in flight, its not the tail end
20418 			 * of the socket buffer  and the cwnd is blocking
20419 			 * us from sending out a minimum pacing segment size.
20420 			 * Lets not send anything.
20421 			 */
20422 			len = 0;
20423 		} else if (((tp->snd_wnd - ctf_outstanding(tp)) <
20424 			    min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
20425 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
20426 			   (len < (int)(sbavail(sb) - sb_offset)) &&
20427 			   (TCPS_HAVEESTABLISHED(tp->t_state))) {
20428 			/*
20429 			 * Here we have a send window but we have
20430 			 * filled it up and we can't send another pacing segment.
20431 			 * We also have in flight more than 2 segments
20432 			 * and we are not completing the sb i.e. we allow
20433 			 * the last bytes of the sb to go out even if
20434 			 * its not a full pacing segment.
20435 			 */
20436 			len = 0;
20437 		} else if ((rack->r_ctl.crte != NULL) &&
20438 			   (tp->snd_wnd >= (pace_max_seg * max(1, rack_hw_rwnd_factor))) &&
20439 			   (cwnd_to_use >= (pace_max_seg + (4 * segsiz))) &&
20440 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) >= (2 * segsiz)) &&
20441 			   (len < (int)(sbavail(sb) - sb_offset))) {
20442 			/*
20443 			 * Here we are doing hardware pacing, this is not a TLP,
20444 			 * we are not sending a pace max segment size, there is rwnd
20445 			 * room to send at least N pace_max_seg, the cwnd is greater
20446 			 * than or equal to a full pacing segments plus 4 mss and we have 2 or
20447 			 * more segments in flight and its not the tail of the socket buffer.
20448 			 *
20449 			 * We don't want to send instead we need to get more ack's in to
20450 			 * allow us to send a full pacing segment. Normally, if we are pacing
20451 			 * about the right speed, we should have finished our pacing
20452 			 * send as most of the acks have come back if we are at the
20453 			 * right rate. This is a bit fuzzy since return path delay
20454 			 * can delay the acks, which is why we want to make sure we
20455 			 * have cwnd space to have a bit more than a max pace segments in flight.
20456 			 *
20457 			 * If we have not gotten our acks back we are pacing at too high a
20458 			 * rate delaying will not hurt and will bring our GP estimate down by
20459 			 * injecting the delay. If we don't do this we will send
20460 			 * 2 MSS out in response to the acks being clocked in which
20461 			 * defeats the point of hw-pacing (i.e. to help us get
20462 			 * larger TSO's out).
20463 			 */
20464 			len = 0;
20465 		}
20466 
20467 	}
20468 	/* len will be >= 0 after this point. */
20469 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
20470 	rack_sndbuf_autoscale(rack);
20471 	/*
20472 	 * Decide if we can use TCP Segmentation Offloading (if supported by
20473 	 * hardware).
20474 	 *
20475 	 * TSO may only be used if we are in a pure bulk sending state.  The
20476 	 * presence of TCP-MD5, SACK retransmits, SACK advertizements and IP
20477 	 * options prevent using TSO.  With TSO the TCP header is the same
20478 	 * (except for the sequence number) for all generated packets.  This
20479 	 * makes it impossible to transmit any options which vary per
20480 	 * generated segment or packet.
20481 	 *
20482 	 * IPv4 handling has a clear separation of ip options and ip header
20483 	 * flags while IPv6 combines both in in6p_outputopts. ip6_optlen() does
20484 	 * the right thing below to provide length of just ip options and thus
20485 	 * checking for ipoptlen is enough to decide if ip options are present.
20486 	 */
20487 	ipoptlen = 0;
20488 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
20489 	/*
20490 	 * Pre-calculate here as we save another lookup into the darknesses
20491 	 * of IPsec that way and can actually decide if TSO is ok.
20492 	 */
20493 #ifdef INET6
20494 	if (isipv6 && IPSEC_ENABLED(ipv6))
20495 		ipsec_optlen = IPSEC_HDRSIZE(ipv6, inp);
20496 #ifdef INET
20497 	else
20498 #endif
20499 #endif				/* INET6 */
20500 #ifdef INET
20501 		if (IPSEC_ENABLED(ipv4))
20502 			ipsec_optlen = IPSEC_HDRSIZE(ipv4, inp);
20503 #endif				/* INET */
20504 #endif
20505 
20506 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
20507 	ipoptlen += ipsec_optlen;
20508 #endif
20509 	if ((tp->t_flags & TF_TSO) && V_tcp_do_tso && len > segsiz &&
20510 	    (tp->t_port == 0) &&
20511 	    ((tp->t_flags & TF_SIGNATURE) == 0) &&
20512 	    tp->rcv_numsacks == 0 && sack_rxmit == 0 &&
20513 	    ipoptlen == 0)
20514 		tso = 1;
20515 	{
20516 		uint32_t outstanding __unused;
20517 
20518 		outstanding = tp->snd_max - tp->snd_una;
20519 		if (tp->t_flags & TF_SENTFIN) {
20520 			/*
20521 			 * If we sent a fin, snd_max is 1 higher than
20522 			 * snd_una
20523 			 */
20524 			outstanding--;
20525 		}
20526 		if (sack_rxmit) {
20527 			if ((rsm->r_flags & RACK_HAS_FIN) == 0)
20528 				flags &= ~TH_FIN;
20529 		} else {
20530 			if (SEQ_LT(tp->snd_nxt + len, tp->snd_una +
20531 				   sbused(sb)))
20532 				flags &= ~TH_FIN;
20533 		}
20534 	}
20535 	recwin = lmin(lmax(sbspace(&so->so_rcv), 0),
20536 		      (long)TCP_MAXWIN << tp->rcv_scale);
20537 
20538 	/*
20539 	 * Sender silly window avoidance.   We transmit under the following
20540 	 * conditions when len is non-zero:
20541 	 *
20542 	 * - We have a full segment (or more with TSO) - This is the last
20543 	 * buffer in a write()/send() and we are either idle or running
20544 	 * NODELAY - we've timed out (e.g. persist timer) - we have more
20545 	 * then 1/2 the maximum send window's worth of data (receiver may be
20546 	 * limited the window size) - we need to retransmit
20547 	 */
20548 	if (len) {
20549 		if (len >= segsiz) {
20550 			goto send;
20551 		}
20552 		/*
20553 		 * NOTE! on localhost connections an 'ack' from the remote
20554 		 * end may occur synchronously with the output and cause us
20555 		 * to flush a buffer queued with moretocome.  XXX
20556 		 *
20557 		 */
20558 		if (!(tp->t_flags & TF_MORETOCOME) &&	/* normal case */
20559 		    (idle || (tp->t_flags & TF_NODELAY)) &&
20560 		    ((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
20561 		    (tp->t_flags & TF_NOPUSH) == 0) {
20562 			pass = 2;
20563 			goto send;
20564 		}
20565 		if ((tp->snd_una == tp->snd_max) && len) {	/* Nothing outstanding */
20566 			pass = 22;
20567 			goto send;
20568 		}
20569 		if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0) {
20570 			pass = 4;
20571 			goto send;
20572 		}
20573 		if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {	/* retransmit case */
20574 			pass = 5;
20575 			goto send;
20576 		}
20577 		if (sack_rxmit) {
20578 			pass = 6;
20579 			goto send;
20580 		}
20581 		if (((tp->snd_wnd - ctf_outstanding(tp)) < segsiz) &&
20582 		    (ctf_outstanding(tp) < (segsiz * 2))) {
20583 			/*
20584 			 * We have less than two MSS outstanding (delayed ack)
20585 			 * and our rwnd will not let us send a full sized
20586 			 * MSS. Lets go ahead and let this small segment
20587 			 * out because we want to try to have at least two
20588 			 * packets inflight to not be caught by delayed ack.
20589 			 */
20590 			pass = 12;
20591 			goto send;
20592 		}
20593 	}
20594 	/*
20595 	 * Sending of standalone window updates.
20596 	 *
20597 	 * Window updates are important when we close our window due to a
20598 	 * full socket buffer and are opening it again after the application
20599 	 * reads data from it.  Once the window has opened again and the
20600 	 * remote end starts to send again the ACK clock takes over and
20601 	 * provides the most current window information.
20602 	 *
20603 	 * We must avoid the silly window syndrome whereas every read from
20604 	 * the receive buffer, no matter how small, causes a window update
20605 	 * to be sent.  We also should avoid sending a flurry of window
20606 	 * updates when the socket buffer had queued a lot of data and the
20607 	 * application is doing small reads.
20608 	 *
20609 	 * Prevent a flurry of pointless window updates by only sending an
20610 	 * update when we can increase the advertized window by more than
20611 	 * 1/4th of the socket buffer capacity.  When the buffer is getting
20612 	 * full or is very small be more aggressive and send an update
20613 	 * whenever we can increase by two mss sized segments. In all other
20614 	 * situations the ACK's to new incoming data will carry further
20615 	 * window increases.
20616 	 *
20617 	 * Don't send an independent window update if a delayed ACK is
20618 	 * pending (it will get piggy-backed on it) or the remote side
20619 	 * already has done a half-close and won't send more data.  Skip
20620 	 * this if the connection is in T/TCP half-open state.
20621 	 */
20622 	if (recwin > 0 && !(tp->t_flags & TF_NEEDSYN) &&
20623 	    !(tp->t_flags & TF_DELACK) &&
20624 	    !TCPS_HAVERCVDFIN(tp->t_state)) {
20625 		/*
20626 		 * "adv" is the amount we could increase the window, taking
20627 		 * into account that we are limited by TCP_MAXWIN <<
20628 		 * tp->rcv_scale.
20629 		 */
20630 		int32_t adv;
20631 		int oldwin;
20632 
20633 		adv = recwin;
20634 		if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt)) {
20635 			oldwin = (tp->rcv_adv - tp->rcv_nxt);
20636 			if (adv > oldwin)
20637 				adv -= oldwin;
20638 			else {
20639 				/* We can't increase the window */
20640 				adv = 0;
20641 			}
20642 		} else
20643 			oldwin = 0;
20644 
20645 		/*
20646 		 * If the new window size ends up being the same as or less
20647 		 * than the old size when it is scaled, then don't force
20648 		 * a window update.
20649 		 */
20650 		if (oldwin >> tp->rcv_scale >= (adv + oldwin) >> tp->rcv_scale)
20651 			goto dontupdate;
20652 
20653 		if (adv >= (int32_t)(2 * segsiz) &&
20654 		    (adv >= (int32_t)(so->so_rcv.sb_hiwat / 4) ||
20655 		     recwin <= (int32_t)(so->so_rcv.sb_hiwat / 8) ||
20656 		     so->so_rcv.sb_hiwat <= 8 * segsiz)) {
20657 			pass = 7;
20658 			goto send;
20659 		}
20660 		if (2 * adv >= (int32_t) so->so_rcv.sb_hiwat) {
20661 			pass = 23;
20662 			goto send;
20663 		}
20664 	}
20665 dontupdate:
20666 
20667 	/*
20668 	 * Send if we owe the peer an ACK, RST, SYN, or urgent data.  ACKNOW
20669 	 * is also a catch-all for the retransmit timer timeout case.
20670 	 */
20671 	if (tp->t_flags & TF_ACKNOW) {
20672 		pass = 8;
20673 		goto send;
20674 	}
20675 	if (((flags & TH_SYN) && (tp->t_flags & TF_NEEDSYN) == 0)) {
20676 		pass = 9;
20677 		goto send;
20678 	}
20679 	/*
20680 	 * If our state indicates that FIN should be sent and we have not
20681 	 * yet done so, then we need to send.
20682 	 */
20683 	if ((flags & TH_FIN) &&
20684 	    (tp->snd_nxt == tp->snd_una)) {
20685 		pass = 11;
20686 		goto send;
20687 	}
20688 	/*
20689 	 * No reason to send a segment, just return.
20690 	 */
20691 just_return:
20692 	SOCKBUF_UNLOCK(sb);
20693 just_return_nolock:
20694 	{
20695 		int app_limited = CTF_JR_SENT_DATA;
20696 
20697 		if (tot_len_this_send > 0) {
20698 			/* Make sure snd_nxt is up to max */
20699 			rack->r_ctl.fsb.recwin = recwin;
20700 			slot = rack_get_pacing_delay(rack, tp, tot_len_this_send, NULL, segsiz);
20701 			if ((error == 0) &&
20702 			    rack_use_rfo &&
20703 			    ((flags & (TH_SYN|TH_FIN)) == 0) &&
20704 			    (ipoptlen == 0) &&
20705 			    (tp->snd_nxt == tp->snd_max) &&
20706 			    (tp->rcv_numsacks == 0) &&
20707 			    rack->r_fsb_inited &&
20708 			    TCPS_HAVEESTABLISHED(tp->t_state) &&
20709 			    ((IN_RECOVERY(tp->t_flags)) == 0) &&
20710 			    (rack->r_must_retran == 0) &&
20711 			    ((tp->t_flags & TF_NEEDFIN) == 0) &&
20712 			    (len > 0) && (orig_len > 0) &&
20713 			    (orig_len > len) &&
20714 			    ((orig_len - len) >= segsiz) &&
20715 			    ((optlen == 0) ||
20716 			     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
20717 				/* We can send at least one more MSS using our fsb */
20718 				rack_setup_fast_output(tp, rack, sb, len, orig_len,
20719 						       segsiz, pace_max_seg, hw_tls, flags);
20720 			} else
20721 				rack->r_fast_output = 0;
20722 
20723 
20724 			rack_log_fsb(rack, tp, so, flags,
20725 				     ipoptlen, orig_len, len, 0,
20726 				     1, optlen, __LINE__, 1);
20727 			if (SEQ_GT(tp->snd_max, tp->snd_nxt))
20728 				tp->snd_nxt = tp->snd_max;
20729 		} else {
20730 			int end_window = 0;
20731 			uint32_t seq = tp->gput_ack;
20732 
20733 			rsm = tqhash_max(rack->r_ctl.tqh);
20734 			if (rsm) {
20735 				/*
20736 				 * Mark the last sent that we just-returned (hinting
20737 				 * that delayed ack may play a role in any rtt measurement).
20738 				 */
20739 				rsm->r_just_ret = 1;
20740 			}
20741 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_JUSTRET], 1);
20742 			rack->r_ctl.rc_agg_delayed = 0;
20743 			rack->r_early = 0;
20744 			rack->r_late = 0;
20745 			rack->r_ctl.rc_agg_early = 0;
20746 			if ((ctf_outstanding(tp) +
20747 			     min(max(segsiz, (rack->r_ctl.rc_high_rwnd/2)),
20748 				 minseg)) >= tp->snd_wnd) {
20749 				/* We are limited by the rwnd */
20750 				app_limited = CTF_JR_RWND_LIMITED;
20751 				if (IN_FASTRECOVERY(tp->t_flags))
20752 					rack->r_ctl.rc_prr_sndcnt = 0;
20753 			} else if (ctf_outstanding(tp) >= sbavail(sb)) {
20754 				/* We are limited by whats available -- app limited */
20755 				app_limited = CTF_JR_APP_LIMITED;
20756 				if (IN_FASTRECOVERY(tp->t_flags))
20757 					rack->r_ctl.rc_prr_sndcnt = 0;
20758 			} else if ((idle == 0) &&
20759 				   ((tp->t_flags & TF_NODELAY) == 0) &&
20760 				   ((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
20761 				   (len < segsiz)) {
20762 				/*
20763 				 * No delay is not on and the
20764 				 * user is sending less than 1MSS. This
20765 				 * brings out SWS avoidance so we
20766 				 * don't send. Another app-limited case.
20767 				 */
20768 				app_limited = CTF_JR_APP_LIMITED;
20769 			} else if (tp->t_flags & TF_NOPUSH) {
20770 				/*
20771 				 * The user has requested no push of
20772 				 * the last segment and we are
20773 				 * at the last segment. Another app
20774 				 * limited case.
20775 				 */
20776 				app_limited = CTF_JR_APP_LIMITED;
20777 			} else if ((ctf_outstanding(tp) + minseg) > cwnd_to_use) {
20778 				/* Its the cwnd */
20779 				app_limited = CTF_JR_CWND_LIMITED;
20780 			} else if (IN_FASTRECOVERY(tp->t_flags) &&
20781 				   (rack->rack_no_prr == 0) &&
20782 				   (rack->r_ctl.rc_prr_sndcnt < segsiz)) {
20783 				app_limited = CTF_JR_PRR;
20784 			} else {
20785 				/* Now why here are we not sending? */
20786 #ifdef NOW
20787 #ifdef INVARIANTS
20788 				panic("rack:%p hit JR_ASSESSING case cwnd_to_use:%u?", rack, cwnd_to_use);
20789 #endif
20790 #endif
20791 				app_limited = CTF_JR_ASSESSING;
20792 			}
20793 			/*
20794 			 * App limited in some fashion, for our pacing GP
20795 			 * measurements we don't want any gap (even cwnd).
20796 			 * Close  down the measurement window.
20797 			 */
20798 			if (rack_cwnd_block_ends_measure &&
20799 			    ((app_limited == CTF_JR_CWND_LIMITED) ||
20800 			     (app_limited == CTF_JR_PRR))) {
20801 				/*
20802 				 * The reason we are not sending is
20803 				 * the cwnd (or prr). We have been configured
20804 				 * to end the measurement window in
20805 				 * this case.
20806 				 */
20807 				end_window = 1;
20808 			} else if (rack_rwnd_block_ends_measure &&
20809 				   (app_limited == CTF_JR_RWND_LIMITED)) {
20810 				/*
20811 				 * We are rwnd limited and have been
20812 				 * configured to end the measurement
20813 				 * window in this case.
20814 				 */
20815 				end_window = 1;
20816 			} else if (app_limited == CTF_JR_APP_LIMITED) {
20817 				/*
20818 				 * A true application limited period, we have
20819 				 * ran out of data.
20820 				 */
20821 				end_window = 1;
20822 			} else if (app_limited == CTF_JR_ASSESSING) {
20823 				/*
20824 				 * In the assessing case we hit the end of
20825 				 * the if/else and had no known reason
20826 				 * This will panic us under invariants..
20827 				 *
20828 				 * If we get this out in logs we need to
20829 				 * investagate which reason we missed.
20830 				 */
20831 				end_window = 1;
20832 			}
20833 			if (end_window) {
20834 				uint8_t log = 0;
20835 
20836 				/* Adjust the Gput measurement */
20837 				if ((tp->t_flags & TF_GPUTINPROG) &&
20838 				    SEQ_GT(tp->gput_ack, tp->snd_max)) {
20839 					tp->gput_ack = tp->snd_max;
20840 					if ((tp->gput_ack - tp->gput_seq) < (MIN_GP_WIN * segsiz)) {
20841 						/*
20842 						 * There is not enough to measure.
20843 						 */
20844 						tp->t_flags &= ~TF_GPUTINPROG;
20845 						rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
20846 									   rack->r_ctl.rc_gp_srtt /*flex1*/,
20847 									   tp->gput_seq,
20848 									   0, 0, 18, __LINE__, NULL, 0);
20849 					} else
20850 						log = 1;
20851 				}
20852 				/* Mark the last packet has app limited */
20853 				rsm = tqhash_max(rack->r_ctl.tqh);
20854 				if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
20855 					if (rack->r_ctl.rc_app_limited_cnt == 0)
20856 						rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
20857 					else {
20858 						/*
20859 						 * Go out to the end app limited and mark
20860 						 * this new one as next and move the end_appl up
20861 						 * to this guy.
20862 						 */
20863 						if (rack->r_ctl.rc_end_appl)
20864 							rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
20865 						rack->r_ctl.rc_end_appl = rsm;
20866 					}
20867 					rsm->r_flags |= RACK_APP_LIMITED;
20868 					rack->r_ctl.rc_app_limited_cnt++;
20869 				}
20870 				if (log)
20871 					rack_log_pacing_delay_calc(rack,
20872 								   rack->r_ctl.rc_app_limited_cnt, seq,
20873 								   tp->gput_ack, 0, 0, 4, __LINE__, NULL, 0);
20874 			}
20875 		}
20876 		/* Check if we need to go into persists or not */
20877 		if ((tp->snd_max == tp->snd_una) &&
20878 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
20879 		    sbavail(sb) &&
20880 		    (sbavail(sb) > tp->snd_wnd) &&
20881 		    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg))) {
20882 			/* Yes lets make sure to move to persist before timer-start */
20883 			rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime, tp->snd_una);
20884 		}
20885 		rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, sup_rack);
20886 		rack_log_type_just_return(rack, cts, tot_len_this_send, slot, hpts_calling, app_limited, cwnd_to_use);
20887 	}
20888 #ifdef NETFLIX_SHARED_CWND
20889 	if ((sbavail(sb) == 0) &&
20890 	    rack->r_ctl.rc_scw) {
20891 		tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
20892 		rack->rack_scwnd_is_idle = 1;
20893 	}
20894 #endif
20895 #ifdef TCP_ACCOUNTING
20896 	if (tot_len_this_send > 0) {
20897 		crtsc = get_cyclecount();
20898 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
20899 			tp->tcp_cnt_counters[SND_OUT_DATA]++;
20900 		}
20901 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
20902 			tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
20903 		}
20904 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
20905 			tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len_this_send + segsiz - 1) / segsiz);
20906 		}
20907 	} else {
20908 		crtsc = get_cyclecount();
20909 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
20910 			tp->tcp_cnt_counters[SND_LIMITED]++;
20911 		}
20912 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
20913 			tp->tcp_proc_time[SND_LIMITED] += (crtsc - ts_val);
20914 		}
20915 	}
20916 	sched_unpin();
20917 #endif
20918 	return (0);
20919 
20920 send:
20921 	if ((rack->r_ctl.crte != NULL) &&
20922 	    (rsm == NULL) &&
20923 	    ((rack->rc_hw_nobuf == 1) ||
20924 	     (rack_hw_check_queue && (check_done == 0)))) {
20925 		/*
20926 		 * We only want to do this once with the hw_check_queue,
20927 		 * for the enobuf case we would only do it once if
20928 		 * we come around to again, the flag will be clear.
20929 		 */
20930 		check_done = 1;
20931 		slot = rack_check_queue_level(rack, tp, &tv, cts, len, segsiz);
20932 		if (slot) {
20933 			rack->r_ctl.rc_agg_delayed = 0;
20934 			rack->r_ctl.rc_agg_early = 0;
20935 			rack->r_early = 0;
20936 			rack->r_late = 0;
20937 			SOCKBUF_UNLOCK(&so->so_snd);
20938 			goto skip_all_send;
20939 		}
20940 	}
20941 	if (rsm || sack_rxmit)
20942 		counter_u64_add(rack_nfto_resend, 1);
20943 	else
20944 		counter_u64_add(rack_non_fto_send, 1);
20945 	if ((flags & TH_FIN) &&
20946 	    sbavail(sb)) {
20947 		/*
20948 		 * We do not transmit a FIN
20949 		 * with data outstanding. We
20950 		 * need to make it so all data
20951 		 * is acked first.
20952 		 */
20953 		flags &= ~TH_FIN;
20954 	}
20955 	/* Enforce stack imposed max seg size if we have one */
20956 	if (rack->r_ctl.rc_pace_max_segs &&
20957 	    (len > rack->r_ctl.rc_pace_max_segs)) {
20958 		mark = 1;
20959 		len = rack->r_ctl.rc_pace_max_segs;
20960 	}
20961 	SOCKBUF_LOCK_ASSERT(sb);
20962 	if (len > 0) {
20963 		if (len >= segsiz)
20964 			tp->t_flags2 |= TF2_PLPMTU_MAXSEGSNT;
20965 		else
20966 			tp->t_flags2 &= ~TF2_PLPMTU_MAXSEGSNT;
20967 	}
20968 	/*
20969 	 * Before ESTABLISHED, force sending of initial options unless TCP
20970 	 * set not to do any options. NOTE: we assume that the IP/TCP header
20971 	 * plus TCP options always fit in a single mbuf, leaving room for a
20972 	 * maximum link header, i.e. max_linkhdr + sizeof (struct tcpiphdr)
20973 	 * + optlen <= MCLBYTES
20974 	 */
20975 	optlen = 0;
20976 #ifdef INET6
20977 	if (isipv6)
20978 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
20979 	else
20980 #endif
20981 		hdrlen = sizeof(struct tcpiphdr);
20982 
20983 	/*
20984 	 * Compute options for segment. We only have to care about SYN and
20985 	 * established connection segments.  Options for SYN-ACK segments
20986 	 * are handled in TCP syncache.
20987 	 */
20988 	to.to_flags = 0;
20989 	if ((tp->t_flags & TF_NOOPT) == 0) {
20990 		/* Maximum segment size. */
20991 		if (flags & TH_SYN) {
20992 			tp->snd_nxt = tp->iss;
20993 			to.to_mss = tcp_mssopt(&inp->inp_inc);
20994 			if (tp->t_port)
20995 				to.to_mss -= V_tcp_udp_tunneling_overhead;
20996 			to.to_flags |= TOF_MSS;
20997 
20998 			/*
20999 			 * On SYN or SYN|ACK transmits on TFO connections,
21000 			 * only include the TFO option if it is not a
21001 			 * retransmit, as the presence of the TFO option may
21002 			 * have caused the original SYN or SYN|ACK to have
21003 			 * been dropped by a middlebox.
21004 			 */
21005 			if (IS_FASTOPEN(tp->t_flags) &&
21006 			    (tp->t_rxtshift == 0)) {
21007 				if (tp->t_state == TCPS_SYN_RECEIVED) {
21008 					to.to_tfo_len = TCP_FASTOPEN_COOKIE_LEN;
21009 					to.to_tfo_cookie =
21010 						(u_int8_t *)&tp->t_tfo_cookie.server;
21011 					to.to_flags |= TOF_FASTOPEN;
21012 					wanted_cookie = 1;
21013 				} else if (tp->t_state == TCPS_SYN_SENT) {
21014 					to.to_tfo_len =
21015 						tp->t_tfo_client_cookie_len;
21016 					to.to_tfo_cookie =
21017 						tp->t_tfo_cookie.client;
21018 					to.to_flags |= TOF_FASTOPEN;
21019 					wanted_cookie = 1;
21020 					/*
21021 					 * If we wind up having more data to
21022 					 * send with the SYN than can fit in
21023 					 * one segment, don't send any more
21024 					 * until the SYN|ACK comes back from
21025 					 * the other end.
21026 					 */
21027 					sendalot = 0;
21028 				}
21029 			}
21030 		}
21031 		/* Window scaling. */
21032 		if ((flags & TH_SYN) && (tp->t_flags & TF_REQ_SCALE)) {
21033 			to.to_wscale = tp->request_r_scale;
21034 			to.to_flags |= TOF_SCALE;
21035 		}
21036 		/* Timestamps. */
21037 		if ((tp->t_flags & TF_RCVD_TSTMP) ||
21038 		    ((flags & TH_SYN) && (tp->t_flags & TF_REQ_TSTMP))) {
21039 			to.to_tsval = ms_cts + tp->ts_offset;
21040 			to.to_tsecr = tp->ts_recent;
21041 			to.to_flags |= TOF_TS;
21042 		}
21043 		/* Set receive buffer autosizing timestamp. */
21044 		if (tp->rfbuf_ts == 0 &&
21045 		    (so->so_rcv.sb_flags & SB_AUTOSIZE))
21046 			tp->rfbuf_ts = tcp_ts_getticks();
21047 		/* Selective ACK's. */
21048 		if (tp->t_flags & TF_SACK_PERMIT) {
21049 			if (flags & TH_SYN)
21050 				to.to_flags |= TOF_SACKPERM;
21051 			else if (TCPS_HAVEESTABLISHED(tp->t_state) &&
21052 				 tp->rcv_numsacks > 0) {
21053 				to.to_flags |= TOF_SACK;
21054 				to.to_nsacks = tp->rcv_numsacks;
21055 				to.to_sacks = (u_char *)tp->sackblks;
21056 			}
21057 		}
21058 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
21059 		/* TCP-MD5 (RFC2385). */
21060 		if (tp->t_flags & TF_SIGNATURE)
21061 			to.to_flags |= TOF_SIGNATURE;
21062 #endif				/* TCP_SIGNATURE */
21063 
21064 		/* Processing the options. */
21065 		hdrlen += optlen = tcp_addoptions(&to, opt);
21066 		/*
21067 		 * If we wanted a TFO option to be added, but it was unable
21068 		 * to fit, ensure no data is sent.
21069 		 */
21070 		if (IS_FASTOPEN(tp->t_flags) && wanted_cookie &&
21071 		    !(to.to_flags & TOF_FASTOPEN))
21072 			len = 0;
21073 	}
21074 	if (tp->t_port) {
21075 		if (V_tcp_udp_tunneling_port == 0) {
21076 			/* The port was removed?? */
21077 			SOCKBUF_UNLOCK(&so->so_snd);
21078 #ifdef TCP_ACCOUNTING
21079 			crtsc = get_cyclecount();
21080 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
21081 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
21082 			}
21083 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
21084 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
21085 			}
21086 			sched_unpin();
21087 #endif
21088 			return (EHOSTUNREACH);
21089 		}
21090 		hdrlen += sizeof(struct udphdr);
21091 	}
21092 #ifdef INET6
21093 	if (isipv6)
21094 		ipoptlen = ip6_optlen(inp);
21095 	else
21096 #endif
21097 		if (inp->inp_options)
21098 			ipoptlen = inp->inp_options->m_len -
21099 				offsetof(struct ipoption, ipopt_list);
21100 		else
21101 			ipoptlen = 0;
21102 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
21103 	ipoptlen += ipsec_optlen;
21104 #endif
21105 
21106 	/*
21107 	 * Adjust data length if insertion of options will bump the packet
21108 	 * length beyond the t_maxseg length. Clear the FIN bit because we
21109 	 * cut off the tail of the segment.
21110 	 */
21111 	if (len + optlen + ipoptlen > tp->t_maxseg) {
21112 		if (tso) {
21113 			uint32_t if_hw_tsomax;
21114 			uint32_t moff;
21115 			int32_t max_len;
21116 
21117 			/* extract TSO information */
21118 			if_hw_tsomax = tp->t_tsomax;
21119 			if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
21120 			if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
21121 			KASSERT(ipoptlen == 0,
21122 				("%s: TSO can't do IP options", __func__));
21123 
21124 			/*
21125 			 * Check if we should limit by maximum payload
21126 			 * length:
21127 			 */
21128 			if (if_hw_tsomax != 0) {
21129 				/* compute maximum TSO length */
21130 				max_len = (if_hw_tsomax - hdrlen -
21131 					   max_linkhdr);
21132 				if (max_len <= 0) {
21133 					len = 0;
21134 				} else if (len > max_len) {
21135 					sendalot = 1;
21136 					len = max_len;
21137 					mark = 2;
21138 				}
21139 			}
21140 			/*
21141 			 * Prevent the last segment from being fractional
21142 			 * unless the send sockbuf can be emptied:
21143 			 */
21144 			max_len = (tp->t_maxseg - optlen);
21145 			if ((sb_offset + len) < sbavail(sb)) {
21146 				moff = len % (u_int)max_len;
21147 				if (moff != 0) {
21148 					mark = 3;
21149 					len -= moff;
21150 				}
21151 			}
21152 			/*
21153 			 * In case there are too many small fragments don't
21154 			 * use TSO:
21155 			 */
21156 			if (len <= max_len) {
21157 				mark = 4;
21158 				tso = 0;
21159 			}
21160 			/*
21161 			 * Send the FIN in a separate segment after the bulk
21162 			 * sending is done. We don't trust the TSO
21163 			 * implementations to clear the FIN flag on all but
21164 			 * the last segment.
21165 			 */
21166 			if (tp->t_flags & TF_NEEDFIN) {
21167 				sendalot = 4;
21168 			}
21169 		} else {
21170 			mark = 5;
21171 			if (optlen + ipoptlen >= tp->t_maxseg) {
21172 				/*
21173 				 * Since we don't have enough space to put
21174 				 * the IP header chain and the TCP header in
21175 				 * one packet as required by RFC 7112, don't
21176 				 * send it. Also ensure that at least one
21177 				 * byte of the payload can be put into the
21178 				 * TCP segment.
21179 				 */
21180 				SOCKBUF_UNLOCK(&so->so_snd);
21181 				error = EMSGSIZE;
21182 				sack_rxmit = 0;
21183 				goto out;
21184 			}
21185 			len = tp->t_maxseg - optlen - ipoptlen;
21186 			sendalot = 5;
21187 		}
21188 	} else {
21189 		tso = 0;
21190 		mark = 6;
21191 	}
21192 	KASSERT(len + hdrlen + ipoptlen <= IP_MAXPACKET,
21193 		("%s: len > IP_MAXPACKET", __func__));
21194 #ifdef DIAGNOSTIC
21195 #ifdef INET6
21196 	if (max_linkhdr + hdrlen > MCLBYTES)
21197 #else
21198 		if (max_linkhdr + hdrlen > MHLEN)
21199 #endif
21200 			panic("tcphdr too big");
21201 #endif
21202 
21203 	/*
21204 	 * This KASSERT is here to catch edge cases at a well defined place.
21205 	 * Before, those had triggered (random) panic conditions further
21206 	 * down.
21207 	 */
21208 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
21209 	if ((len == 0) &&
21210 	    (flags & TH_FIN) &&
21211 	    (sbused(sb))) {
21212 		/*
21213 		 * We have outstanding data, don't send a fin by itself!.
21214 		 */
21215 		goto just_return;
21216 	}
21217 	/*
21218 	 * Grab a header mbuf, attaching a copy of data to be transmitted,
21219 	 * and initialize the header from the template for sends on this
21220 	 * connection.
21221 	 */
21222 	hw_tls = tp->t_nic_ktls_xmit != 0;
21223 	if (len) {
21224 		uint32_t max_val;
21225 		uint32_t moff;
21226 
21227 		if (rack->r_ctl.rc_pace_max_segs)
21228 			max_val = rack->r_ctl.rc_pace_max_segs;
21229 		else if (rack->rc_user_set_max_segs)
21230 			max_val = rack->rc_user_set_max_segs * segsiz;
21231 		else
21232 			max_val = len;
21233 		/*
21234 		 * We allow a limit on sending with hptsi.
21235 		 */
21236 		if (len > max_val) {
21237 			mark = 7;
21238 			len = max_val;
21239 		}
21240 #ifdef INET6
21241 		if (MHLEN < hdrlen + max_linkhdr)
21242 			m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
21243 		else
21244 #endif
21245 			m = m_gethdr(M_NOWAIT, MT_DATA);
21246 
21247 		if (m == NULL) {
21248 			SOCKBUF_UNLOCK(sb);
21249 			error = ENOBUFS;
21250 			sack_rxmit = 0;
21251 			goto out;
21252 		}
21253 		m->m_data += max_linkhdr;
21254 		m->m_len = hdrlen;
21255 
21256 		/*
21257 		 * Start the m_copy functions from the closest mbuf to the
21258 		 * sb_offset in the socket buffer chain.
21259 		 */
21260 		mb = sbsndptr_noadv(sb, sb_offset, &moff);
21261 		s_mb = mb;
21262 		s_moff = moff;
21263 		if (len <= MHLEN - hdrlen - max_linkhdr && !hw_tls) {
21264 			m_copydata(mb, moff, (int)len,
21265 				   mtod(m, caddr_t)+hdrlen);
21266 			if (SEQ_LT(tp->snd_nxt, tp->snd_max))
21267 				sbsndptr_adv(sb, mb, len);
21268 			m->m_len += len;
21269 		} else {
21270 			struct sockbuf *msb;
21271 
21272 			if (SEQ_LT(tp->snd_nxt, tp->snd_max))
21273 				msb = NULL;
21274 			else
21275 				msb = sb;
21276 			m->m_next = tcp_m_copym(
21277 				mb, moff, &len,
21278 				if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, msb,
21279 				((rsm == NULL) ? hw_tls : 0)
21280 #ifdef NETFLIX_COPY_ARGS
21281 				, &s_mb, &s_moff
21282 #endif
21283 				);
21284 			if (len <= (tp->t_maxseg - optlen)) {
21285 				/*
21286 				 * Must have ran out of mbufs for the copy
21287 				 * shorten it to no longer need tso. Lets
21288 				 * not put on sendalot since we are low on
21289 				 * mbufs.
21290 				 */
21291 				tso = 0;
21292 			}
21293 			if (m->m_next == NULL) {
21294 				SOCKBUF_UNLOCK(sb);
21295 				(void)m_free(m);
21296 				error = ENOBUFS;
21297 				sack_rxmit = 0;
21298 				goto out;
21299 			}
21300 		}
21301 		if (SEQ_LT(tp->snd_nxt, tp->snd_max) || sack_rxmit) {
21302 			if (rsm && (rsm->r_flags & RACK_TLP)) {
21303 				/*
21304 				 * TLP should not count in retran count, but
21305 				 * in its own bin
21306 				 */
21307 				counter_u64_add(rack_tlp_retran, 1);
21308 				counter_u64_add(rack_tlp_retran_bytes, len);
21309 			} else {
21310 				tp->t_sndrexmitpack++;
21311 				KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
21312 				KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
21313 			}
21314 #ifdef STATS
21315 			stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
21316 						 len);
21317 #endif
21318 		} else {
21319 			KMOD_TCPSTAT_INC(tcps_sndpack);
21320 			KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
21321 #ifdef STATS
21322 			stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
21323 						 len);
21324 #endif
21325 		}
21326 		/*
21327 		 * If we're sending everything we've got, set PUSH. (This
21328 		 * will keep happy those implementations which only give
21329 		 * data to the user when a buffer fills or a PUSH comes in.)
21330 		 */
21331 		if (sb_offset + len == sbused(sb) &&
21332 		    sbused(sb) &&
21333 		    !(flags & TH_SYN)) {
21334 			flags |= TH_PUSH;
21335 			add_flag |= RACK_HAD_PUSH;
21336 		}
21337 
21338 		SOCKBUF_UNLOCK(sb);
21339 	} else {
21340 		SOCKBUF_UNLOCK(sb);
21341 		if (tp->t_flags & TF_ACKNOW)
21342 			KMOD_TCPSTAT_INC(tcps_sndacks);
21343 		else if (flags & (TH_SYN | TH_FIN | TH_RST))
21344 			KMOD_TCPSTAT_INC(tcps_sndctrl);
21345 		else
21346 			KMOD_TCPSTAT_INC(tcps_sndwinup);
21347 
21348 		m = m_gethdr(M_NOWAIT, MT_DATA);
21349 		if (m == NULL) {
21350 			error = ENOBUFS;
21351 			sack_rxmit = 0;
21352 			goto out;
21353 		}
21354 #ifdef INET6
21355 		if (isipv6 && (MHLEN < hdrlen + max_linkhdr) &&
21356 		    MHLEN >= hdrlen) {
21357 			M_ALIGN(m, hdrlen);
21358 		} else
21359 #endif
21360 			m->m_data += max_linkhdr;
21361 		m->m_len = hdrlen;
21362 	}
21363 	SOCKBUF_UNLOCK_ASSERT(sb);
21364 	m->m_pkthdr.rcvif = (struct ifnet *)0;
21365 #ifdef MAC
21366 	mac_inpcb_create_mbuf(inp, m);
21367 #endif
21368 	if ((ipoptlen == 0) && (rack->r_ctl.fsb.tcp_ip_hdr) &&  rack->r_fsb_inited) {
21369 #ifdef INET6
21370 		if (isipv6)
21371 			ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
21372 		else
21373 #endif				/* INET6 */
21374 #ifdef INET
21375 			ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
21376 #endif
21377 		th = rack->r_ctl.fsb.th;
21378 		udp = rack->r_ctl.fsb.udp;
21379 		if (udp) {
21380 #ifdef INET6
21381 			if (isipv6)
21382 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
21383 			else
21384 #endif				/* INET6 */
21385 				ulen = hdrlen + len - sizeof(struct ip);
21386 			udp->uh_ulen = htons(ulen);
21387 		}
21388 	} else {
21389 #ifdef INET6
21390 		if (isipv6) {
21391 			ip6 = mtod(m, struct ip6_hdr *);
21392 			if (tp->t_port) {
21393 				udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
21394 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
21395 				udp->uh_dport = tp->t_port;
21396 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
21397 				udp->uh_ulen = htons(ulen);
21398 				th = (struct tcphdr *)(udp + 1);
21399 			} else
21400 				th = (struct tcphdr *)(ip6 + 1);
21401 			tcpip_fillheaders(inp, tp->t_port, ip6, th);
21402 		} else
21403 #endif				/* INET6 */
21404 		{
21405 #ifdef INET
21406 			ip = mtod(m, struct ip *);
21407 			if (tp->t_port) {
21408 				udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
21409 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
21410 				udp->uh_dport = tp->t_port;
21411 				ulen = hdrlen + len - sizeof(struct ip);
21412 				udp->uh_ulen = htons(ulen);
21413 				th = (struct tcphdr *)(udp + 1);
21414 			} else
21415 				th = (struct tcphdr *)(ip + 1);
21416 			tcpip_fillheaders(inp, tp->t_port, ip, th);
21417 #endif
21418 		}
21419 	}
21420 	/*
21421 	 * Fill in fields, remembering maximum advertised window for use in
21422 	 * delaying messages about window sizes. If resending a FIN, be sure
21423 	 * not to use a new sequence number.
21424 	 */
21425 	if (flags & TH_FIN && tp->t_flags & TF_SENTFIN &&
21426 	    tp->snd_nxt == tp->snd_max)
21427 		tp->snd_nxt--;
21428 	/*
21429 	 * If we are starting a connection, send ECN setup SYN packet. If we
21430 	 * are on a retransmit, we may resend those bits a number of times
21431 	 * as per RFC 3168.
21432 	 */
21433 	if (tp->t_state == TCPS_SYN_SENT && V_tcp_do_ecn) {
21434 		flags |= tcp_ecn_output_syn_sent(tp);
21435 	}
21436 	/* Also handle parallel SYN for ECN */
21437 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
21438 	    (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))) {
21439 		int ect = tcp_ecn_output_established(tp, &flags, len, sack_rxmit);
21440 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
21441 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
21442 			tp->t_flags2 &= ~TF2_ECN_SND_ECE;
21443 #ifdef INET6
21444 		if (isipv6) {
21445 			ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
21446 			ip6->ip6_flow |= htonl(ect << 20);
21447 		}
21448 		else
21449 #endif
21450 		{
21451 #ifdef INET
21452 			ip->ip_tos &= ~IPTOS_ECN_MASK;
21453 			ip->ip_tos |= ect;
21454 #endif
21455 		}
21456 	}
21457 	/*
21458 	 * If we are doing retransmissions, then snd_nxt will not reflect
21459 	 * the first unsent octet.  For ACK only packets, we do not want the
21460 	 * sequence number of the retransmitted packet, we want the sequence
21461 	 * number of the next unsent octet.  So, if there is no data (and no
21462 	 * SYN or FIN), use snd_max instead of snd_nxt when filling in
21463 	 * ti_seq.  But if we are in persist state, snd_max might reflect
21464 	 * one byte beyond the right edge of the window, so use snd_nxt in
21465 	 * that case, since we know we aren't doing a retransmission.
21466 	 * (retransmit and persist are mutually exclusive...)
21467 	 */
21468 	if (sack_rxmit == 0) {
21469 		if (len || (flags & (TH_SYN | TH_FIN))) {
21470 			th->th_seq = htonl(tp->snd_nxt);
21471 			rack_seq = tp->snd_nxt;
21472 		} else {
21473 			th->th_seq = htonl(tp->snd_max);
21474 			rack_seq = tp->snd_max;
21475 		}
21476 	} else {
21477 		th->th_seq = htonl(rsm->r_start);
21478 		rack_seq = rsm->r_start;
21479 	}
21480 	th->th_ack = htonl(tp->rcv_nxt);
21481 	tcp_set_flags(th, flags);
21482 	/*
21483 	 * Calculate receive window.  Don't shrink window, but avoid silly
21484 	 * window syndrome.
21485 	 * If a RST segment is sent, advertise a window of zero.
21486 	 */
21487 	if (flags & TH_RST) {
21488 		recwin = 0;
21489 	} else {
21490 		if (recwin < (long)(so->so_rcv.sb_hiwat / 4) &&
21491 		    recwin < (long)segsiz) {
21492 			recwin = 0;
21493 		}
21494 		if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) &&
21495 		    recwin < (long)(tp->rcv_adv - tp->rcv_nxt))
21496 			recwin = (long)(tp->rcv_adv - tp->rcv_nxt);
21497 	}
21498 
21499 	/*
21500 	 * According to RFC1323 the window field in a SYN (i.e., a <SYN> or
21501 	 * <SYN,ACK>) segment itself is never scaled.  The <SYN,ACK> case is
21502 	 * handled in syncache.
21503 	 */
21504 	if (flags & TH_SYN)
21505 		th->th_win = htons((u_short)
21506 				   (min(sbspace(&so->so_rcv), TCP_MAXWIN)));
21507 	else {
21508 		/* Avoid shrinking window with window scaling. */
21509 		recwin = roundup2(recwin, 1 << tp->rcv_scale);
21510 		th->th_win = htons((u_short)(recwin >> tp->rcv_scale));
21511 	}
21512 	/*
21513 	 * Adjust the RXWIN0SENT flag - indicate that we have advertised a 0
21514 	 * window.  This may cause the remote transmitter to stall.  This
21515 	 * flag tells soreceive() to disable delayed acknowledgements when
21516 	 * draining the buffer.  This can occur if the receiver is
21517 	 * attempting to read more data than can be buffered prior to
21518 	 * transmitting on the connection.
21519 	 */
21520 	if (th->th_win == 0) {
21521 		tp->t_sndzerowin++;
21522 		tp->t_flags |= TF_RXWIN0SENT;
21523 	} else
21524 		tp->t_flags &= ~TF_RXWIN0SENT;
21525 	tp->snd_up = tp->snd_una;	/* drag it along, its deprecated */
21526 	/* Now are we using fsb?, if so copy the template data to the mbuf */
21527 	if ((ipoptlen == 0) && (rack->r_ctl.fsb.tcp_ip_hdr) && rack->r_fsb_inited) {
21528 		uint8_t *cpto;
21529 
21530 		cpto = mtod(m, uint8_t *);
21531 		memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
21532 		/*
21533 		 * We have just copied in:
21534 		 * IP/IP6
21535 		 * <optional udphdr>
21536 		 * tcphdr (no options)
21537 		 *
21538 		 * We need to grab the correct pointers into the mbuf
21539 		 * for both the tcp header, and possibly the udp header (if tunneling).
21540 		 * We do this by using the offset in the copy buffer and adding it
21541 		 * to the mbuf base pointer (cpto).
21542 		 */
21543 #ifdef INET6
21544 		if (isipv6)
21545 			ip6 = mtod(m, struct ip6_hdr *);
21546 		else
21547 #endif				/* INET6 */
21548 #ifdef INET
21549 			ip = mtod(m, struct ip *);
21550 #endif
21551 		th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
21552 		/* If we have a udp header lets set it into the mbuf as well */
21553 		if (udp)
21554 			udp = (struct udphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.udp - rack->r_ctl.fsb.tcp_ip_hdr));
21555 	}
21556 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
21557 	if (to.to_flags & TOF_SIGNATURE) {
21558 		/*
21559 		 * Calculate MD5 signature and put it into the place
21560 		 * determined before.
21561 		 * NOTE: since TCP options buffer doesn't point into
21562 		 * mbuf's data, calculate offset and use it.
21563 		 */
21564 		if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
21565 						       (u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
21566 			/*
21567 			 * Do not send segment if the calculation of MD5
21568 			 * digest has failed.
21569 			 */
21570 			goto out;
21571 		}
21572 	}
21573 #endif
21574 	if (optlen) {
21575 		bcopy(opt, th + 1, optlen);
21576 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
21577 	}
21578 	/*
21579 	 * Put TCP length in extended header, and then checksum extended
21580 	 * header and data.
21581 	 */
21582 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
21583 #ifdef INET6
21584 	if (isipv6) {
21585 		/*
21586 		 * ip6_plen is not need to be filled now, and will be filled
21587 		 * in ip6_output.
21588 		 */
21589 		if (tp->t_port) {
21590 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
21591 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
21592 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
21593 			th->th_sum = htons(0);
21594 			UDPSTAT_INC(udps_opackets);
21595 		} else {
21596 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
21597 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
21598 			th->th_sum = in6_cksum_pseudo(ip6,
21599 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
21600 						      0);
21601 		}
21602 	}
21603 #endif
21604 #if defined(INET6) && defined(INET)
21605 	else
21606 #endif
21607 #ifdef INET
21608 	{
21609 		if (tp->t_port) {
21610 			m->m_pkthdr.csum_flags = CSUM_UDP;
21611 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
21612 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
21613 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
21614 			th->th_sum = htons(0);
21615 			UDPSTAT_INC(udps_opackets);
21616 		} else {
21617 			m->m_pkthdr.csum_flags = CSUM_TCP;
21618 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
21619 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
21620 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
21621 									IPPROTO_TCP + len + optlen));
21622 		}
21623 		/* IP version must be set here for ipv4/ipv6 checking later */
21624 		KASSERT(ip->ip_v == IPVERSION,
21625 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
21626 	}
21627 #endif
21628 	/*
21629 	 * Enable TSO and specify the size of the segments. The TCP pseudo
21630 	 * header checksum is always provided. XXX: Fixme: This is currently
21631 	 * not the case for IPv6.
21632 	 */
21633 	if (tso) {
21634 		/*
21635 		 * Here we must use t_maxseg and the optlen since
21636 		 * the optlen may include SACK's (or DSACK).
21637 		 */
21638 		KASSERT(len > tp->t_maxseg - optlen,
21639 			("%s: len <= tso_segsz", __func__));
21640 		m->m_pkthdr.csum_flags |= CSUM_TSO;
21641 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
21642 	}
21643 	KASSERT(len + hdrlen == m_length(m, NULL),
21644 		("%s: mbuf chain different than expected: %d + %u != %u",
21645 		 __func__, len, hdrlen, m_length(m, NULL)));
21646 
21647 #ifdef TCP_HHOOK
21648 	/* Run HHOOK_TCP_ESTABLISHED_OUT helper hooks. */
21649 	hhook_run_tcp_est_out(tp, th, &to, len, tso);
21650 #endif
21651 	if ((rack->r_ctl.crte != NULL) &&
21652 	    (rack->rc_hw_nobuf == 0) &&
21653 	    tcp_bblogging_on(tp)) {
21654 		rack_log_queue_level(tp, rack, len, &tv, cts);
21655 	}
21656 	/* We're getting ready to send; log now. */
21657 	if (tcp_bblogging_on(rack->rc_tp)) {
21658 		union tcp_log_stackspecific log;
21659 
21660 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
21661 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
21662 		if (rack->rack_no_prr)
21663 			log.u_bbr.flex1 = 0;
21664 		else
21665 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
21666 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
21667 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
21668 		log.u_bbr.flex4 = orig_len;
21669 		/* Save off the early/late values */
21670 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
21671 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
21672 		log.u_bbr.bw_inuse = rack_get_bw(rack);
21673 		log.u_bbr.cur_del_rate = rack->r_ctl.gp_bw;
21674 		log.u_bbr.flex8 = 0;
21675 		if (rsm) {
21676 			if (rsm->r_flags & RACK_RWND_COLLAPSED) {
21677 				rack_log_collapse(rack, rsm->r_start, rsm->r_end, 0, __LINE__, 5, rsm->r_flags, rsm);
21678 				counter_u64_add(rack_collapsed_win_rxt, 1);
21679 				counter_u64_add(rack_collapsed_win_rxt_bytes, (rsm->r_end - rsm->r_start));
21680 			}
21681 			if (doing_tlp)
21682 				log.u_bbr.flex8 = 2;
21683 			else
21684 				log.u_bbr.flex8 = 1;
21685 		} else {
21686 			if (doing_tlp)
21687 				log.u_bbr.flex8 = 3;
21688 		}
21689 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
21690 		log.u_bbr.flex7 = mark;
21691 		log.u_bbr.flex7 <<= 8;
21692 		log.u_bbr.flex7 |= pass;
21693 		log.u_bbr.pkts_out = tp->t_maxseg;
21694 		log.u_bbr.timeStamp = cts;
21695 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
21696 		if (rsm && (rsm->r_rtr_cnt > 0)) {
21697 			/*
21698 			 * When we have a retransmit we want to log the
21699 			 * burst at send and flight at send from before.
21700 			 */
21701 			log.u_bbr.flex5 = rsm->r_fas;
21702 			log.u_bbr.bbr_substate = rsm->r_bas;
21703 		} else {
21704 			/*
21705 			 * New transmits we log in flex5 the inflight again as
21706 			 * well as the number of segments in our send in the
21707 			 * substate field.
21708 			 */
21709 			log.u_bbr.flex5 = log.u_bbr.inflight;
21710 			log.u_bbr.bbr_substate = (uint8_t)((len + segsiz - 1)/segsiz);
21711 		}
21712 		log.u_bbr.lt_epoch = cwnd_to_use;
21713 		log.u_bbr.delivered = sendalot;
21714 		log.u_bbr.rttProp = (uint64_t)rsm;
21715 		log.u_bbr.pkt_epoch = __LINE__;
21716 		if (rsm) {
21717 			log.u_bbr.delRate = rsm->r_flags;
21718 			log.u_bbr.delRate <<= 31;
21719 			log.u_bbr.delRate |= rack->r_must_retran;
21720 			log.u_bbr.delRate <<= 1;
21721 			log.u_bbr.delRate |= (sack_rxmit & 0x00000001);
21722 		} else {
21723 			log.u_bbr.delRate = rack->r_must_retran;
21724 			log.u_bbr.delRate <<= 1;
21725 			log.u_bbr.delRate |= (sack_rxmit & 0x00000001);
21726 		}
21727 		lgb = tcp_log_event(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_OUT, ERRNO_UNK,
21728 				    len, &log, false, NULL, __func__, __LINE__, &tv);
21729 	} else
21730 		lgb = NULL;
21731 
21732 	/*
21733 	 * Fill in IP length and desired time to live and send to IP level.
21734 	 * There should be a better way to handle ttl and tos; we could keep
21735 	 * them in the template, but need a way to checksum without them.
21736 	 */
21737 	/*
21738 	 * m->m_pkthdr.len should have been set before cksum calcuration,
21739 	 * because in6_cksum() need it.
21740 	 */
21741 #ifdef INET6
21742 	if (isipv6) {
21743 		/*
21744 		 * we separately set hoplimit for every segment, since the
21745 		 * user might want to change the value via setsockopt. Also,
21746 		 * desired default hop limit might be changed via Neighbor
21747 		 * Discovery.
21748 		 */
21749 		rack->r_ctl.fsb.hoplimit = ip6->ip6_hlim = in6_selecthlim(inp, NULL);
21750 
21751 		/*
21752 		 * Set the packet size here for the benefit of DTrace
21753 		 * probes. ip6_output() will set it properly; it's supposed
21754 		 * to include the option header lengths as well.
21755 		 */
21756 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
21757 
21758 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
21759 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
21760 		else
21761 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
21762 
21763 		if (tp->t_state == TCPS_SYN_SENT)
21764 			TCP_PROBE5(connect__request, NULL, tp, ip6, tp, th);
21765 
21766 		TCP_PROBE5(send, NULL, tp, ip6, tp, th);
21767 		/* TODO: IPv6 IP6TOS_ECT bit on */
21768 		error = ip6_output(m,
21769 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
21770 				   inp->in6p_outputopts,
21771 #else
21772 				   NULL,
21773 #endif
21774 				   &inp->inp_route6,
21775 				   ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0),
21776 				   NULL, NULL, inp);
21777 
21778 		if (error == EMSGSIZE && inp->inp_route6.ro_nh != NULL)
21779 			mtu = inp->inp_route6.ro_nh->nh_mtu;
21780 	}
21781 #endif				/* INET6 */
21782 #if defined(INET) && defined(INET6)
21783 	else
21784 #endif
21785 #ifdef INET
21786 	{
21787 		ip->ip_len = htons(m->m_pkthdr.len);
21788 #ifdef INET6
21789 		if (inp->inp_vflag & INP_IPV6PROTO)
21790 			ip->ip_ttl = in6_selecthlim(inp, NULL);
21791 #endif				/* INET6 */
21792 		rack->r_ctl.fsb.hoplimit = ip->ip_ttl;
21793 		/*
21794 		 * If we do path MTU discovery, then we set DF on every
21795 		 * packet. This might not be the best thing to do according
21796 		 * to RFC3390 Section 2. However the tcp hostcache migitates
21797 		 * the problem so it affects only the first tcp connection
21798 		 * with a host.
21799 		 *
21800 		 * NB: Don't set DF on small MTU/MSS to have a safe
21801 		 * fallback.
21802 		 */
21803 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
21804 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
21805 			if (tp->t_port == 0 || len < V_tcp_minmss) {
21806 				ip->ip_off |= htons(IP_DF);
21807 			}
21808 		} else {
21809 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
21810 		}
21811 
21812 		if (tp->t_state == TCPS_SYN_SENT)
21813 			TCP_PROBE5(connect__request, NULL, tp, ip, tp, th);
21814 
21815 		TCP_PROBE5(send, NULL, tp, ip, tp, th);
21816 
21817 		error = ip_output(m,
21818 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
21819 				  inp->inp_options,
21820 #else
21821 				  NULL,
21822 #endif
21823 				  &inp->inp_route,
21824 				  ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0), 0,
21825 				  inp);
21826 		if (error == EMSGSIZE && inp->inp_route.ro_nh != NULL)
21827 			mtu = inp->inp_route.ro_nh->nh_mtu;
21828 	}
21829 #endif				/* INET */
21830 
21831 out:
21832 	if (lgb) {
21833 		lgb->tlb_errno = error;
21834 		lgb = NULL;
21835 	}
21836 	/*
21837 	 * In transmit state, time the transmission and arrange for the
21838 	 * retransmit.  In persist state, just set snd_max.
21839 	 */
21840 	rack_log_output(tp, &to, len, rack_seq, (uint8_t) flags, error,
21841 			rack_to_usec_ts(&tv),
21842 			rsm, add_flag, s_mb, s_moff, hw_tls, segsiz);
21843 	if (error == 0) {
21844 		if (rsm == NULL) {
21845 			if (rack->lt_bw_up == 0) {
21846 				rack->r_ctl.lt_timemark = tcp_tv_to_lusectick(&tv);
21847 				rack->r_ctl.lt_seq = tp->snd_una;
21848 				rack->lt_bw_up = 1;
21849 			} else if (((rack_seq + len) - rack->r_ctl.lt_seq) > 0x7fffffff) {
21850 				/*
21851 				 * Need to record what we have since we are
21852 				 * approaching seq wrap.
21853 				 */
21854 				uint64_t tmark;
21855 
21856 				rack->r_ctl.lt_bw_bytes += (tp->snd_una - rack->r_ctl.lt_seq);
21857 				rack->r_ctl.lt_seq = tp->snd_una;
21858 				tmark = tcp_tv_to_lusectick(&tv);
21859 				rack->r_ctl.lt_bw_time += (tmark - rack->r_ctl.lt_timemark);
21860 				rack->r_ctl.lt_timemark = tmark;
21861 			}
21862 		}
21863 		rack->forced_ack = 0;	/* If we send something zap the FA flag */
21864 		counter_u64_add(rack_total_bytes, len);
21865 		tcp_account_for_send(tp, len, (rsm != NULL), doing_tlp, hw_tls);
21866 		if (rsm && doing_tlp) {
21867 			rack->rc_last_sent_tlp_past_cumack = 0;
21868 			rack->rc_last_sent_tlp_seq_valid = 1;
21869 			rack->r_ctl.last_sent_tlp_seq = rsm->r_start;
21870 			rack->r_ctl.last_sent_tlp_len = rsm->r_end - rsm->r_start;
21871 		}
21872 		if (rack->rc_hw_nobuf) {
21873 			rack->rc_hw_nobuf = 0;
21874 			rack->r_ctl.rc_agg_delayed = 0;
21875 			rack->r_early = 0;
21876 			rack->r_late = 0;
21877 			rack->r_ctl.rc_agg_early = 0;
21878 		}
21879 		if (rsm && (doing_tlp == 0)) {
21880 			/* Set we retransmitted */
21881 			rack->rc_gp_saw_rec = 1;
21882 		} else {
21883 			if (cwnd_to_use > tp->snd_ssthresh) {
21884 				/* Set we sent in CA */
21885 				rack->rc_gp_saw_ca = 1;
21886 			} else {
21887 				/* Set we sent in SS */
21888 				rack->rc_gp_saw_ss = 1;
21889 			}
21890 		}
21891 		if (TCPS_HAVEESTABLISHED(tp->t_state) &&
21892 		    (tp->t_flags & TF_SACK_PERMIT) &&
21893 		    tp->rcv_numsacks > 0)
21894 			tcp_clean_dsack_blocks(tp);
21895 		tot_len_this_send += len;
21896 		if (len == 0) {
21897 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_SNDACK], 1);
21898 		} else {
21899 			int idx;
21900 
21901 			idx = (len / segsiz) + 3;
21902 			if (idx >= TCP_MSS_ACCT_ATIMER)
21903 				counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
21904 			else
21905 				counter_u64_add(rack_out_size[idx], 1);
21906 		}
21907 	}
21908 	if ((rack->rack_no_prr == 0) &&
21909 	    sub_from_prr &&
21910 	    (error == 0)) {
21911 		if (rack->r_ctl.rc_prr_sndcnt >= len)
21912 			rack->r_ctl.rc_prr_sndcnt -= len;
21913 		else
21914 			rack->r_ctl.rc_prr_sndcnt = 0;
21915 	}
21916 	sub_from_prr = 0;
21917 	if (doing_tlp) {
21918 		/* Make sure the TLP is added */
21919 		add_flag |= RACK_TLP;
21920 	} else if (rsm) {
21921 		/* If its a resend without TLP then it must not have the flag */
21922 		rsm->r_flags &= ~RACK_TLP;
21923 	}
21924 
21925 
21926 	if ((error == 0) &&
21927 	    (len > 0) &&
21928 	    (tp->snd_una == tp->snd_max))
21929 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
21930 	{
21931 		tcp_seq startseq = tp->snd_nxt;
21932 
21933 		/* Track our lost count */
21934 		if (rsm && (doing_tlp == 0))
21935 			rack->r_ctl.rc_loss_count += rsm->r_end - rsm->r_start;
21936 		/*
21937 		 * Advance snd_nxt over sequence space of this segment.
21938 		 */
21939 		if (error)
21940 			/* We don't log or do anything with errors */
21941 			goto nomore;
21942 		if (doing_tlp == 0) {
21943 			if (rsm == NULL) {
21944 				/*
21945 				 * Not a retransmission of some
21946 				 * sort, new data is going out so
21947 				 * clear our TLP count and flag.
21948 				 */
21949 				rack->rc_tlp_in_progress = 0;
21950 				rack->r_ctl.rc_tlp_cnt_out = 0;
21951 			}
21952 		} else {
21953 			/*
21954 			 * We have just sent a TLP, mark that it is true
21955 			 * and make sure our in progress is set so we
21956 			 * continue to check the count.
21957 			 */
21958 			rack->rc_tlp_in_progress = 1;
21959 			rack->r_ctl.rc_tlp_cnt_out++;
21960 		}
21961 		if (flags & (TH_SYN | TH_FIN)) {
21962 			if (flags & TH_SYN)
21963 				tp->snd_nxt++;
21964 			if (flags & TH_FIN) {
21965 				tp->snd_nxt++;
21966 				tp->t_flags |= TF_SENTFIN;
21967 			}
21968 		}
21969 		/* In the ENOBUFS case we do *not* update snd_max */
21970 		if (sack_rxmit)
21971 			goto nomore;
21972 
21973 		tp->snd_nxt += len;
21974 		if (SEQ_GT(tp->snd_nxt, tp->snd_max)) {
21975 			if (tp->snd_una == tp->snd_max) {
21976 				/*
21977 				 * Update the time we just added data since
21978 				 * none was outstanding.
21979 				 */
21980 				rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
21981 				tp->t_acktime = ticks;
21982 			}
21983 			tp->snd_max = tp->snd_nxt;
21984 			if (rack->rc_new_rnd_needed) {
21985 				/*
21986 				 * Update the rnd to start ticking not
21987 				 * that from a time perspective all of
21988 				 * the preceding idle time is "in the round"
21989 				 */
21990 				rack->rc_new_rnd_needed = 0;
21991 				rack->r_ctl.roundends = tp->snd_max;
21992 			}
21993 			/*
21994 			 * Time this transmission if not a retransmission and
21995 			 * not currently timing anything.
21996 			 * This is only relevant in case of switching back to
21997 			 * the base stack.
21998 			 */
21999 			if (tp->t_rtttime == 0) {
22000 				tp->t_rtttime = ticks;
22001 				tp->t_rtseq = startseq;
22002 				KMOD_TCPSTAT_INC(tcps_segstimed);
22003 			}
22004 			if (len &&
22005 			    ((tp->t_flags & TF_GPUTINPROG) == 0))
22006 				rack_start_gp_measurement(tp, rack, startseq, sb_offset);
22007 		}
22008 		/*
22009 		 * If we are doing FO we need to update the mbuf position and subtract
22010 		 * this happens when the peer sends us duplicate information and
22011 		 * we thus want to send a DSACK.
22012 		 *
22013 		 * XXXRRS: This brings to mind a ?, when we send a DSACK block is TSO
22014 		 * turned off? If not then we are going to echo multiple DSACK blocks
22015 		 * out (with the TSO), which we should not be doing.
22016 		 */
22017 		if (rack->r_fast_output && len) {
22018 			if (rack->r_ctl.fsb.left_to_send > len)
22019 				rack->r_ctl.fsb.left_to_send -= len;
22020 			else
22021 				rack->r_ctl.fsb.left_to_send = 0;
22022 			if (rack->r_ctl.fsb.left_to_send < segsiz)
22023 				rack->r_fast_output = 0;
22024 			if (rack->r_fast_output) {
22025 				rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
22026 				rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
22027 				rack->r_ctl.fsb.o_t_len = M_TRAILINGROOM(rack->r_ctl.fsb.m);
22028 			}
22029 		}
22030 	}
22031 nomore:
22032 	if (error) {
22033 		rack->r_ctl.rc_agg_delayed = 0;
22034 		rack->r_early = 0;
22035 		rack->r_late = 0;
22036 		rack->r_ctl.rc_agg_early = 0;
22037 		SOCKBUF_UNLOCK_ASSERT(sb);	/* Check gotos. */
22038 		/*
22039 		 * Failures do not advance the seq counter above. For the
22040 		 * case of ENOBUFS we will fall out and retry in 1ms with
22041 		 * the hpts. Everything else will just have to retransmit
22042 		 * with the timer.
22043 		 *
22044 		 * In any case, we do not want to loop around for another
22045 		 * send without a good reason.
22046 		 */
22047 		sendalot = 0;
22048 		switch (error) {
22049 		case EPERM:
22050 			tp->t_softerror = error;
22051 #ifdef TCP_ACCOUNTING
22052 			crtsc = get_cyclecount();
22053 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22054 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
22055 			}
22056 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22057 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
22058 			}
22059 			sched_unpin();
22060 #endif
22061 			return (error);
22062 		case ENOBUFS:
22063 			/*
22064 			 * Pace us right away to retry in a some
22065 			 * time
22066 			 */
22067 			if (rack->r_ctl.crte != NULL) {
22068 				tcp_trace_point(rack->rc_tp, TCP_TP_HWENOBUF);
22069 				if (tcp_bblogging_on(rack->rc_tp))
22070 					rack_log_queue_level(tp, rack, len, &tv, cts);
22071 			} else
22072 				tcp_trace_point(rack->rc_tp, TCP_TP_ENOBUF);
22073 			slot = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
22074 			if (rack->rc_enobuf < 0x7f)
22075 				rack->rc_enobuf++;
22076 			if (slot < (10 * HPTS_USEC_IN_MSEC))
22077 				slot = 10 * HPTS_USEC_IN_MSEC;
22078 			if (rack->r_ctl.crte != NULL) {
22079 				counter_u64_add(rack_saw_enobuf_hw, 1);
22080 				tcp_rl_log_enobuf(rack->r_ctl.crte);
22081 			}
22082 			counter_u64_add(rack_saw_enobuf, 1);
22083 			goto enobufs;
22084 		case EMSGSIZE:
22085 			/*
22086 			 * For some reason the interface we used initially
22087 			 * to send segments changed to another or lowered
22088 			 * its MTU. If TSO was active we either got an
22089 			 * interface without TSO capabilits or TSO was
22090 			 * turned off. If we obtained mtu from ip_output()
22091 			 * then update it and try again.
22092 			 */
22093 			if (tso)
22094 				tp->t_flags &= ~TF_TSO;
22095 			if (mtu != 0) {
22096 				int saved_mtu;
22097 
22098 				saved_mtu = tp->t_maxseg;
22099 				tcp_mss_update(tp, -1, mtu, NULL, NULL);
22100 				if (saved_mtu > tp->t_maxseg) {
22101 					goto again;
22102 				}
22103 			}
22104 			slot = 10 * HPTS_USEC_IN_MSEC;
22105 			rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
22106 #ifdef TCP_ACCOUNTING
22107 			crtsc = get_cyclecount();
22108 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22109 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
22110 			}
22111 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22112 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
22113 			}
22114 			sched_unpin();
22115 #endif
22116 			return (error);
22117 		case ENETUNREACH:
22118 			counter_u64_add(rack_saw_enetunreach, 1);
22119 		case EHOSTDOWN:
22120 		case EHOSTUNREACH:
22121 		case ENETDOWN:
22122 			if (TCPS_HAVERCVDSYN(tp->t_state)) {
22123 				tp->t_softerror = error;
22124 			}
22125 			/* FALLTHROUGH */
22126 		default:
22127 			slot = 10 * HPTS_USEC_IN_MSEC;
22128 			rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
22129 #ifdef TCP_ACCOUNTING
22130 			crtsc = get_cyclecount();
22131 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22132 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
22133 			}
22134 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22135 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
22136 			}
22137 			sched_unpin();
22138 #endif
22139 			return (error);
22140 		}
22141 	} else {
22142 		rack->rc_enobuf = 0;
22143 		if (IN_FASTRECOVERY(tp->t_flags) && rsm)
22144 			rack->r_ctl.retran_during_recovery += len;
22145 	}
22146 	KMOD_TCPSTAT_INC(tcps_sndtotal);
22147 
22148 	/*
22149 	 * Data sent (as far as we can tell). If this advertises a larger
22150 	 * window than any other segment, then remember the size of the
22151 	 * advertised window. Any pending ACK has now been sent.
22152 	 */
22153 	if (recwin > 0 && SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv))
22154 		tp->rcv_adv = tp->rcv_nxt + recwin;
22155 
22156 	tp->last_ack_sent = tp->rcv_nxt;
22157 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
22158 enobufs:
22159 	if (sendalot) {
22160 		/* Do we need to turn off sendalot? */
22161 		if (rack->r_ctl.rc_pace_max_segs &&
22162 		    (tot_len_this_send >= rack->r_ctl.rc_pace_max_segs)) {
22163 			/* We hit our max. */
22164 			sendalot = 0;
22165 		} else if ((rack->rc_user_set_max_segs) &&
22166 			   (tot_len_this_send >= (rack->rc_user_set_max_segs * segsiz))) {
22167 			/* We hit the user defined max */
22168 			sendalot = 0;
22169 		}
22170 	}
22171 	if ((error == 0) && (flags & TH_FIN))
22172 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_FIN);
22173 	if (flags & TH_RST) {
22174 		/*
22175 		 * We don't send again after sending a RST.
22176 		 */
22177 		slot = 0;
22178 		sendalot = 0;
22179 		if (error == 0)
22180 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
22181 	} else if ((slot == 0) && (sendalot == 0) && tot_len_this_send) {
22182 		/*
22183 		 * Get our pacing rate, if an error
22184 		 * occurred in sending (ENOBUF) we would
22185 		 * hit the else if with slot preset. Other
22186 		 * errors return.
22187 		 */
22188 		slot = rack_get_pacing_delay(rack, tp, tot_len_this_send, rsm, segsiz);
22189 	}
22190 	if (rsm &&
22191 	    (rsm->r_flags & RACK_HAS_SYN) == 0 &&
22192 	    rack->use_rack_rr) {
22193 		/* Its a retransmit and we use the rack cheat? */
22194 		if ((slot == 0) ||
22195 		    (rack->rc_always_pace == 0) ||
22196 		    (rack->r_rr_config == 1)) {
22197 			/*
22198 			 * We have no pacing set or we
22199 			 * are using old-style rack or
22200 			 * we are overridden to use the old 1ms pacing.
22201 			 */
22202 			slot = rack->r_ctl.rc_min_to;
22203 		}
22204 	}
22205 	/* We have sent clear the flag */
22206 	rack->r_ent_rec_ns = 0;
22207 	if (rack->r_must_retran) {
22208 		if (rsm) {
22209 			rack->r_ctl.rc_out_at_rto -= (rsm->r_end - rsm->r_start);
22210 			if (SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) {
22211 				/*
22212 				 * We have retransmitted all.
22213 				 */
22214 				rack->r_must_retran = 0;
22215 				rack->r_ctl.rc_out_at_rto = 0;
22216 			}
22217 		} else if (SEQ_GEQ(tp->snd_max, rack->r_ctl.rc_snd_max_at_rto)) {
22218 			/*
22219 			 * Sending new data will also kill
22220 			 * the loop.
22221 			 */
22222 			rack->r_must_retran = 0;
22223 			rack->r_ctl.rc_out_at_rto = 0;
22224 		}
22225 	}
22226 	rack->r_ctl.fsb.recwin = recwin;
22227 	if ((tp->t_flags & (TF_WASCRECOVERY|TF_WASFRECOVERY)) &&
22228 	    SEQ_GT(tp->snd_max, rack->r_ctl.rc_snd_max_at_rto)) {
22229 		/*
22230 		 * We hit an RTO and now have past snd_max at the RTO
22231 		 * clear all the WAS flags.
22232 		 */
22233 		tp->t_flags &= ~(TF_WASCRECOVERY|TF_WASFRECOVERY);
22234 	}
22235 	if (slot) {
22236 		/* set the rack tcb into the slot N */
22237 		if ((error == 0) &&
22238 		    rack_use_rfo &&
22239 		    ((flags & (TH_SYN|TH_FIN)) == 0) &&
22240 		    (rsm == NULL) &&
22241 		    (tp->snd_nxt == tp->snd_max) &&
22242 		    (ipoptlen == 0) &&
22243 		    (tp->rcv_numsacks == 0) &&
22244 		    rack->r_fsb_inited &&
22245 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
22246 		    ((IN_RECOVERY(tp->t_flags)) == 0) &&
22247 		    (rack->r_must_retran == 0) &&
22248 		    ((tp->t_flags & TF_NEEDFIN) == 0) &&
22249 		    (len > 0) && (orig_len > 0) &&
22250 		    (orig_len > len) &&
22251 		    ((orig_len - len) >= segsiz) &&
22252 		    ((optlen == 0) ||
22253 		     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
22254 			/* We can send at least one more MSS using our fsb */
22255 			rack_setup_fast_output(tp, rack, sb, len, orig_len,
22256 					       segsiz, pace_max_seg, hw_tls, flags);
22257 		} else
22258 			rack->r_fast_output = 0;
22259 		rack_log_fsb(rack, tp, so, flags,
22260 			     ipoptlen, orig_len, len, error,
22261 			     (rsm == NULL), optlen, __LINE__, 2);
22262 	} else if (sendalot) {
22263 		int ret;
22264 
22265 		sack_rxmit = 0;
22266 		if ((error == 0) &&
22267 		    rack_use_rfo &&
22268 		    ((flags & (TH_SYN|TH_FIN)) == 0) &&
22269 		    (rsm == NULL) &&
22270 		    (ipoptlen == 0) &&
22271 		    (tp->rcv_numsacks == 0) &&
22272 		    (tp->snd_nxt == tp->snd_max) &&
22273 		    (rack->r_must_retran == 0) &&
22274 		    rack->r_fsb_inited &&
22275 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
22276 		    ((IN_RECOVERY(tp->t_flags)) == 0) &&
22277 		    ((tp->t_flags & TF_NEEDFIN) == 0) &&
22278 		    (len > 0) && (orig_len > 0) &&
22279 		    (orig_len > len) &&
22280 		    ((orig_len - len) >= segsiz) &&
22281 		    ((optlen == 0) ||
22282 		     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
22283 			/* we can use fast_output for more */
22284 			rack_setup_fast_output(tp, rack, sb, len, orig_len,
22285 					       segsiz, pace_max_seg, hw_tls, flags);
22286 			if (rack->r_fast_output) {
22287 				error = 0;
22288 				ret = rack_fast_output(tp, rack, ts_val, cts, ms_cts, &tv, tot_len_this_send, &error);
22289 				if (ret >= 0)
22290 					return (ret);
22291 			        else if (error)
22292 					goto nomore;
22293 
22294 			}
22295 		}
22296 		goto again;
22297 	}
22298 	/* Assure when we leave that snd_nxt will point to top */
22299 skip_all_send:
22300 	if (SEQ_GT(tp->snd_max, tp->snd_nxt))
22301 		tp->snd_nxt = tp->snd_max;
22302 	rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, 0);
22303 #ifdef TCP_ACCOUNTING
22304 	crtsc = get_cyclecount() - ts_val;
22305 	if (tot_len_this_send) {
22306 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22307 			tp->tcp_cnt_counters[SND_OUT_DATA]++;
22308 		}
22309 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22310 			tp->tcp_proc_time[SND_OUT_DATA] += crtsc;
22311 		}
22312 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22313 			tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len_this_send + segsiz - 1) /segsiz);
22314 		}
22315 	} else {
22316 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22317 			tp->tcp_cnt_counters[SND_OUT_ACK]++;
22318 		}
22319 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22320 			tp->tcp_proc_time[SND_OUT_ACK] += crtsc;
22321 		}
22322 	}
22323 	sched_unpin();
22324 #endif
22325 	if (error == ENOBUFS)
22326 		error = 0;
22327 	return (error);
22328 }
22329 
22330 static void
22331 rack_update_seg(struct tcp_rack *rack)
22332 {
22333 	uint32_t orig_val;
22334 
22335 	orig_val = rack->r_ctl.rc_pace_max_segs;
22336 	rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
22337 	if (orig_val != rack->r_ctl.rc_pace_max_segs)
22338 		rack_log_pacing_delay_calc(rack, 0, 0, orig_val, 0, 0, 15, __LINE__, NULL, 0);
22339 }
22340 
22341 static void
22342 rack_mtu_change(struct tcpcb *tp)
22343 {
22344 	/*
22345 	 * The MSS may have changed
22346 	 */
22347 	struct tcp_rack *rack;
22348 	struct rack_sendmap *rsm;
22349 
22350 	rack = (struct tcp_rack *)tp->t_fb_ptr;
22351 	if (rack->r_ctl.rc_pace_min_segs != ctf_fixed_maxseg(tp)) {
22352 		/*
22353 		 * The MTU has changed we need to resend everything
22354 		 * since all we have sent is lost. We first fix
22355 		 * up the mtu though.
22356 		 */
22357 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
22358 		/* We treat this like a full retransmit timeout without the cwnd adjustment */
22359 		rack_remxt_tmr(tp);
22360 		rack->r_fast_output = 0;
22361 		rack->r_ctl.rc_out_at_rto = ctf_flight_size(tp,
22362 						rack->r_ctl.rc_sacked);
22363 		rack->r_ctl.rc_snd_max_at_rto = tp->snd_max;
22364 		rack->r_must_retran = 1;
22365 		/* Mark all inflight to needing to be rxt'd */
22366 		TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
22367 			rsm->r_flags |= (RACK_MUST_RXT|RACK_PMTU_CHG);
22368 		}
22369 	}
22370 	sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
22371 	/* We don't use snd_nxt to retransmit */
22372 	tp->snd_nxt = tp->snd_max;
22373 }
22374 
22375 static int
22376 rack_set_dgp(struct tcp_rack *rack)
22377 {
22378 	/* pace_always=1 */
22379 	if (rack->rc_always_pace == 0) {
22380 		if (tcp_can_enable_pacing() == 0)
22381 			return (EBUSY);
22382 	}
22383 	rack->dgp_on = 1;
22384 	rack->rc_always_pace = 1;
22385 	rack->use_fixed_rate = 0;
22386 	if (rack->gp_ready)
22387 		rack_set_cc_pacing(rack);
22388 	rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
22389 	rack->rack_attempt_hdwr_pace = 0;
22390 	/* rxt settings */
22391 	rack->full_size_rxt = 1;
22392 	rack->shape_rxt_to_pacing_min  = 0;
22393 	/* cmpack=1 */
22394 	rack->r_use_cmp_ack = 1;
22395 	if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state) &&
22396 	    rack->r_use_cmp_ack)
22397 		rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
22398 	/* scwnd=1 */
22399 	rack->rack_enable_scwnd = 1;
22400 	/* dynamic=100 */
22401 	rack->rc_gp_dyn_mul = 1;
22402 	/* gp_inc_ca */
22403 	rack->r_ctl.rack_per_of_gp_ca = 100;
22404 	/* rrr_conf=3 */
22405 	rack->r_rr_config = 3;
22406 	/* npush=2 */
22407 	rack->r_ctl.rc_no_push_at_mrtt = 2;
22408 	/* fillcw=1 */
22409 	if (rack->r_cwnd_was_clamped == 0) {
22410 		rack->rc_pace_to_cwnd = 1;
22411 	} else {
22412 		rack->rc_pace_to_cwnd = 0;
22413 		/* Reset all multipliers to 100.0 so just the measured bw */
22414 		rack->r_ctl.rack_per_of_gp_ss = 100;
22415 		rack->r_ctl.rack_per_of_gp_ca = 100;
22416 	}
22417 	rack->rc_pace_fill_if_rttin_range = 0;
22418 	rack->rtt_limit_mul = 0;
22419 	/* noprr=1 */
22420 	rack->rack_no_prr = 1;
22421 	/* lscwnd=1 */
22422 	rack->r_limit_scw = 1;
22423 	/* gp_inc_rec */
22424 	rack->r_ctl.rack_per_of_gp_rec = 90;
22425 	rack_client_buffer_level_set(rack);
22426 	return (0);
22427 }
22428 
22429 
22430 
22431 static int
22432 rack_set_profile(struct tcp_rack *rack, int prof)
22433 {
22434 	int err = EINVAL;
22435 	if (prof == 1) {
22436 		/*
22437 		 * Profile 1 is "standard" DGP. It ignores
22438 		 * client buffer level.
22439 		 */
22440 		rack->r_ctl.rc_dgp_bl_agg = DGP_LEVEL0;
22441 		err = rack_set_dgp(rack);
22442 		if (err)
22443 			return (err);
22444 	} else if (prof == 2) {
22445 		/*
22446 		 * Profile 2 is DGP. Less aggressive with
22447 		 * respect to client buffer level.
22448 		 */
22449 		rack->r_ctl.rc_dgp_bl_agg = DGP_LEVEL1;
22450 		err = rack_set_dgp(rack);
22451 		if (err)
22452 			return (err);
22453 	} else if (prof == 3) {
22454 		/*
22455 		 * Profile 3 is DGP. Even Less aggressive with
22456 		 * respect to client buffer level.
22457 		 */
22458 		rack->r_ctl.rc_dgp_bl_agg = DGP_LEVEL2;
22459 		err = rack_set_dgp(rack);
22460 		if (err)
22461 			return (err);
22462 	} else if (prof == 4) {
22463 		/*
22464 		 * Profile 4 is DGP with the most responsiveness
22465 		 * to client buffer level.
22466 		 */
22467 		rack->r_ctl.rc_dgp_bl_agg = DGP_LEVEL3;
22468 		err = rack_set_dgp(rack);
22469 		if (err)
22470 			return (err);
22471 	} else if (prof == 0) {
22472 		/* This changes things back to the default settings */
22473 		rack->dgp_on = 0;
22474 		rack->rc_hybrid_mode = 0;
22475 		err = 0;
22476 		if (rack_fill_cw_state)
22477 			rack->rc_pace_to_cwnd = 1;
22478 		else
22479 			rack->rc_pace_to_cwnd = 0;
22480 		if (rack->rc_always_pace) {
22481 			tcp_decrement_paced_conn();
22482 			rack_undo_cc_pacing(rack);
22483 			rack->rc_always_pace = 0;
22484 		}
22485 		if (rack_pace_every_seg && tcp_can_enable_pacing()) {
22486 			rack->rc_always_pace = 1;
22487 			if ((rack->gp_ready) && (rack->use_fixed_rate == 0))
22488 				rack_set_cc_pacing(rack);
22489 		} else
22490 			rack->rc_always_pace = 0;
22491 		if (rack_dsack_std_based & 0x1) {
22492 			/* Basically this means all rack timers are at least (srtt + 1/4 srtt) */
22493 			rack->rc_rack_tmr_std_based = 1;
22494 		}
22495 		if (rack_dsack_std_based & 0x2) {
22496 			/* Basically this means  rack timers are extended based on dsack by up to (2 * srtt) */
22497 			rack->rc_rack_use_dsack = 1;
22498 		}
22499 		if (rack_use_cmp_acks)
22500 			rack->r_use_cmp_ack = 1;
22501 		else
22502 			rack->r_use_cmp_ack = 0;
22503 		if (rack_disable_prr)
22504 			rack->rack_no_prr = 1;
22505 		else
22506 			rack->rack_no_prr = 0;
22507 		if (rack_gp_no_rec_chg)
22508 			rack->rc_gp_no_rec_chg = 1;
22509 		else
22510 			rack->rc_gp_no_rec_chg = 0;
22511 		if (rack_enable_mqueue_for_nonpaced || rack->r_use_cmp_ack) {
22512 			rack->r_mbuf_queue = 1;
22513 			if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state))
22514 				rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
22515 			rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
22516 		} else {
22517 			rack->r_mbuf_queue = 0;
22518 			rack->rc_inp->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
22519 		}
22520 		if (rack_enable_shared_cwnd)
22521 			rack->rack_enable_scwnd = 1;
22522 		else
22523 			rack->rack_enable_scwnd = 0;
22524 		if (rack_do_dyn_mul) {
22525 			/* When dynamic adjustment is on CA needs to start at 100% */
22526 			rack->rc_gp_dyn_mul = 1;
22527 			if (rack_do_dyn_mul >= 100)
22528 				rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
22529 		} else {
22530 			rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
22531 			rack->rc_gp_dyn_mul = 0;
22532 		}
22533 		rack->r_rr_config = 0;
22534 		rack->r_ctl.rc_no_push_at_mrtt = 0;
22535 		rack->rc_pace_to_cwnd = 0;
22536 		rack->rc_pace_fill_if_rttin_range = 0;
22537 		rack->rtt_limit_mul = 0;
22538 
22539 		if (rack_enable_hw_pacing)
22540 			rack->rack_hdw_pace_ena = 1;
22541 		else
22542 			rack->rack_hdw_pace_ena = 0;
22543 		if (rack_disable_prr)
22544 			rack->rack_no_prr = 1;
22545 		else
22546 			rack->rack_no_prr = 0;
22547 		if (rack_limits_scwnd)
22548 			rack->r_limit_scw  = 1;
22549 		else
22550 			rack->r_limit_scw  = 0;
22551 		rack_init_retransmit_value(rack, rack_rxt_controls);
22552 		err = 0;
22553 	}
22554 	return (err);
22555 }
22556 
22557 static int
22558 rack_add_deferred_option(struct tcp_rack *rack, int sopt_name, uint64_t loptval)
22559 {
22560 	struct deferred_opt_list *dol;
22561 
22562 	dol = malloc(sizeof(struct deferred_opt_list),
22563 		     M_TCPFSB, M_NOWAIT|M_ZERO);
22564 	if (dol == NULL) {
22565 		/*
22566 		 * No space yikes -- fail out..
22567 		 */
22568 		return (0);
22569 	}
22570 	dol->optname = sopt_name;
22571 	dol->optval = loptval;
22572 	TAILQ_INSERT_TAIL(&rack->r_ctl.opt_list, dol, next);
22573 	return (1);
22574 }
22575 
22576 static int
22577 process_hybrid_pacing(struct tcp_rack *rack, struct tcp_hybrid_req *hybrid)
22578 {
22579 #ifdef TCP_REQUEST_TRK
22580 	struct http_sendfile_track *sft;
22581 	struct timeval tv;
22582 	tcp_seq seq;
22583 	int err;
22584 
22585 	microuptime(&tv);
22586 
22587 	/*
22588 	 * If BB logging is not on we need to look at the DTL flag.
22589 	 * If its on already then those reasons override the DTL input.
22590 	 * We do this with any request, you can turn DTL on, but it does
22591 	 * not turn off at least from hybrid pacing requests.
22592 	 */
22593 	if (tcp_bblogging_on(rack->rc_tp) == 0) {
22594 		if (hybrid->hybrid_flags & TCP_HYBRID_PACING_DTL) {
22595 			/* Turn on BB point logging  */
22596 			tcp_set_bblog_state(rack->rc_tp, TCP_LOG_VIA_BBPOINTS,
22597 					    TCP_BBPOINT_REQ_LEVEL_LOGGING);
22598 		}
22599 	}
22600 	/* Make sure no fixed rate is on */
22601 	rack->use_fixed_rate = 0;
22602 	rack->r_ctl.rc_fixed_pacing_rate_rec = 0;
22603 	rack->r_ctl.rc_fixed_pacing_rate_ca = 0;
22604 	rack->r_ctl.rc_fixed_pacing_rate_ss = 0;
22605 	/* Now allocate or find our entry that will have these settings */
22606 	sft = tcp_http_alloc_req_full(rack->rc_tp, &hybrid->req, tcp_tv_to_lusectick(&tv), 0);
22607 	if (sft == NULL) {
22608 		rack->rc_tp->tcp_hybrid_error++;
22609 		/* no space, where would it have gone? */
22610 		seq = rack->rc_tp->snd_una + rack->rc_tp->t_inpcb.inp_socket->so_snd.sb_ccc;
22611 		rack_log_hybrid(rack, seq, NULL, HYBRID_LOG_NO_ROOM, __LINE__, 0);
22612 		return (ENOSPC);
22613 	}
22614 	/* The seq will be snd_una + everything in the buffer */
22615 	seq = sft->start_seq;
22616 	if ((hybrid->hybrid_flags & TCP_HYBRID_PACING_ENABLE) == 0) {
22617 		/* Disabling hybrid pacing */
22618 		if (rack->rc_hybrid_mode) {
22619 			rack_set_profile(rack, 0);
22620 			rack->rc_tp->tcp_hybrid_stop++;
22621 		}
22622 		rack_log_hybrid(rack, seq, sft, HYBRID_LOG_TURNED_OFF, __LINE__, 0);
22623 		return (0);
22624 	}
22625 	if (rack->dgp_on == 0) {
22626 		/*
22627 		 * If we have not yet turned DGP on, do so
22628 		 * now setting pure DGP mode, no buffer level
22629 		 * response.
22630 		 */
22631 		if ((err = rack_set_profile(rack, 1)) != 0){
22632 			/* Failed to turn pacing on */
22633 			rack->rc_tp->tcp_hybrid_error++;
22634 			rack_log_hybrid(rack, seq, sft, HYBRID_LOG_NO_PACING, __LINE__, 0);
22635 			return (err);
22636 		}
22637 	}
22638 	/* Now set in our flags */
22639 	sft->hybrid_flags = hybrid->hybrid_flags;
22640 	if (hybrid->hybrid_flags & TCP_HYBRID_PACING_CSPR)
22641 		sft->cspr = hybrid->cspr;
22642 	else
22643 		sft->cspr = 0;
22644 	if (hybrid->hybrid_flags & TCP_HYBRID_PACING_H_MS)
22645 		sft->hint_maxseg = hybrid->hint_maxseg;
22646 	else
22647 		sft->hint_maxseg = 0;
22648 	rack->rc_hybrid_mode = 1;
22649 	rack->rc_tp->tcp_hybrid_start++;
22650 	rack_log_hybrid(rack, seq, sft, HYBRID_LOG_RULES_SET, __LINE__,0);
22651 	return (0);
22652 #else
22653 	return (ENOTSUP);
22654 #endif
22655 }
22656 
22657 static int
22658 rack_process_option(struct tcpcb *tp, struct tcp_rack *rack, int sopt_name,
22659 		    uint32_t optval, uint64_t loptval, struct tcp_hybrid_req *hybrid)
22660 
22661 {
22662 	struct epoch_tracker et;
22663 	struct sockopt sopt;
22664 	struct cc_newreno_opts opt;
22665 	struct inpcb *inp = tptoinpcb(tp);
22666 	uint64_t val;
22667 	int error = 0;
22668 	uint16_t ca, ss;
22669 
22670 	switch (sopt_name) {
22671 	case TCP_RACK_SET_RXT_OPTIONS:
22672 		if ((optval >= 0) && (optval <= 2)) {
22673 			rack_init_retransmit_value(rack, optval);
22674 		} else {
22675 			/*
22676 			 * You must send in 0, 1 or 2 all else is
22677 			 * invalid.
22678 			 */
22679 			error = EINVAL;
22680 		}
22681 		break;
22682 	case TCP_RACK_DSACK_OPT:
22683 		RACK_OPTS_INC(tcp_rack_dsack_opt);
22684 		if (optval & 0x1) {
22685 			rack->rc_rack_tmr_std_based = 1;
22686 		} else {
22687 			rack->rc_rack_tmr_std_based = 0;
22688 		}
22689 		if (optval & 0x2) {
22690 			rack->rc_rack_use_dsack = 1;
22691 		} else {
22692 			rack->rc_rack_use_dsack = 0;
22693 		}
22694 		rack_log_dsack_event(rack, 5, __LINE__, 0, 0);
22695 		break;
22696 	case TCP_RACK_PACING_DIVISOR:
22697 		RACK_OPTS_INC(tcp_rack_pacing_divisor);
22698 		if (optval == 0) {
22699 			rack->r_ctl.pace_len_divisor = rack_default_pacing_divisor;
22700 		} else {
22701 			if (optval < RL_MIN_DIVISOR)
22702 				rack->r_ctl.pace_len_divisor = RL_MIN_DIVISOR;
22703 			else
22704 				rack->r_ctl.pace_len_divisor = optval;
22705 		}
22706 		break;
22707 	case TCP_RACK_HI_BETA:
22708 		RACK_OPTS_INC(tcp_rack_hi_beta);
22709 		if (optval)
22710 			rack->rack_hibeta = 1;
22711 		else
22712 			rack->rack_hibeta = 0;
22713 		break;
22714 	case TCP_RACK_PACING_BETA:
22715 		RACK_OPTS_INC(tcp_rack_beta);
22716 		if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0) {
22717 			/* This only works for newreno. */
22718 			error = EINVAL;
22719 			break;
22720 		}
22721 		if (rack->rc_pacing_cc_set) {
22722 			/*
22723 			 * Set them into the real CC module
22724 			 * whats in the rack pcb is the old values
22725 			 * to be used on restoral/
22726 			 */
22727 			sopt.sopt_dir = SOPT_SET;
22728 			opt.name = CC_NEWRENO_BETA;
22729 			opt.val = optval;
22730 			if (CC_ALGO(tp)->ctl_output != NULL)
22731 				error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
22732 			else {
22733 				error = ENOENT;
22734 				break;
22735 			}
22736 		} else {
22737 			/*
22738 			 * Not pacing yet so set it into our local
22739 			 * rack pcb storage.
22740 			 */
22741 			rack->r_ctl.rc_saved_beta.beta = optval;
22742 		}
22743 		break;
22744 	case TCP_RACK_TIMER_SLOP:
22745 		RACK_OPTS_INC(tcp_rack_timer_slop);
22746 		rack->r_ctl.timer_slop = optval;
22747 		if (rack->rc_tp->t_srtt) {
22748 			/*
22749 			 * If we have an SRTT lets update t_rxtcur
22750 			 * to have the new slop.
22751 			 */
22752 			RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
22753 					   rack_rto_min, rack_rto_max,
22754 					   rack->r_ctl.timer_slop);
22755 		}
22756 		break;
22757 	case TCP_RACK_PACING_BETA_ECN:
22758 		RACK_OPTS_INC(tcp_rack_beta_ecn);
22759 		if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0) {
22760 			/* This only works for newreno. */
22761 			error = EINVAL;
22762 			break;
22763 		}
22764 		if (rack->rc_pacing_cc_set) {
22765 			/*
22766 			 * Set them into the real CC module
22767 			 * whats in the rack pcb is the old values
22768 			 * to be used on restoral/
22769 			 */
22770 			sopt.sopt_dir = SOPT_SET;
22771 			opt.name = CC_NEWRENO_BETA_ECN;
22772 			opt.val = optval;
22773 			if (CC_ALGO(tp)->ctl_output != NULL)
22774 				error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
22775 			else
22776 				error = ENOENT;
22777 		} else {
22778 			/*
22779 			 * Not pacing yet so set it into our local
22780 			 * rack pcb storage.
22781 			 */
22782 			rack->r_ctl.rc_saved_beta.beta_ecn = optval;
22783 			rack->r_ctl.rc_saved_beta.newreno_flags = CC_NEWRENO_BETA_ECN_ENABLED;
22784 		}
22785 		break;
22786 	case TCP_DEFER_OPTIONS:
22787 		RACK_OPTS_INC(tcp_defer_opt);
22788 		if (optval) {
22789 			if (rack->gp_ready) {
22790 				/* Too late */
22791 				error = EINVAL;
22792 				break;
22793 			}
22794 			rack->defer_options = 1;
22795 		} else
22796 			rack->defer_options = 0;
22797 		break;
22798 	case TCP_RACK_MEASURE_CNT:
22799 		RACK_OPTS_INC(tcp_rack_measure_cnt);
22800 		if (optval && (optval <= 0xff)) {
22801 			rack->r_ctl.req_measurements = optval;
22802 		} else
22803 			error = EINVAL;
22804 		break;
22805 	case TCP_REC_ABC_VAL:
22806 		RACK_OPTS_INC(tcp_rec_abc_val);
22807 		if (optval > 0)
22808 			rack->r_use_labc_for_rec = 1;
22809 		else
22810 			rack->r_use_labc_for_rec = 0;
22811 		break;
22812 	case TCP_RACK_ABC_VAL:
22813 		RACK_OPTS_INC(tcp_rack_abc_val);
22814 		if ((optval > 0) && (optval < 255))
22815 			rack->rc_labc = optval;
22816 		else
22817 			error = EINVAL;
22818 		break;
22819 	case TCP_HDWR_UP_ONLY:
22820 		RACK_OPTS_INC(tcp_pacing_up_only);
22821 		if (optval)
22822 			rack->r_up_only = 1;
22823 		else
22824 			rack->r_up_only = 0;
22825 		break;
22826 	case TCP_PACING_RATE_CAP:
22827 		RACK_OPTS_INC(tcp_pacing_rate_cap);
22828 		rack->r_ctl.bw_rate_cap = loptval;
22829 		break;
22830 	case TCP_HYBRID_PACING:
22831 		if (hybrid == NULL) {
22832 			error = EINVAL;
22833 			break;
22834 		}
22835 		error = process_hybrid_pacing(rack, hybrid);
22836 		break;
22837 	case TCP_RACK_PROFILE:
22838 		RACK_OPTS_INC(tcp_profile);
22839 		error = rack_set_profile(rack, optval);
22840 		break;
22841 	case TCP_USE_CMP_ACKS:
22842 		RACK_OPTS_INC(tcp_use_cmp_acks);
22843 		if ((optval == 0) && (rack->rc_inp->inp_flags2 & INP_MBUF_ACKCMP)) {
22844 			/* You can't turn it off once its on! */
22845 			error = EINVAL;
22846 		} else if ((optval == 1) && (rack->r_use_cmp_ack == 0)) {
22847 			rack->r_use_cmp_ack = 1;
22848 			rack->r_mbuf_queue = 1;
22849 			inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
22850 		}
22851 		if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
22852 			inp->inp_flags2 |= INP_MBUF_ACKCMP;
22853 		break;
22854 	case TCP_SHARED_CWND_TIME_LIMIT:
22855 		RACK_OPTS_INC(tcp_lscwnd);
22856 		if (optval)
22857 			rack->r_limit_scw = 1;
22858 		else
22859 			rack->r_limit_scw = 0;
22860 		break;
22861 	case TCP_RACK_DGP_IN_REC:
22862 		RACK_OPTS_INC(tcp_dgp_in_rec);
22863 		if (optval)
22864 			rack->r_ctl.full_dgp_in_rec = 1;
22865 		else
22866 			rack->r_ctl.full_dgp_in_rec = 0;
22867 		break;
22868 	case TCP_RXT_CLAMP:
22869 		RACK_OPTS_INC(tcp_rxt_clamp);
22870 		rack_translate_clamp_value(rack, optval);
22871 		break;
22872  	case TCP_RACK_PACE_TO_FILL:
22873 		RACK_OPTS_INC(tcp_fillcw);
22874 		if (optval == 0)
22875 			rack->rc_pace_to_cwnd = 0;
22876 		else {
22877 			rack->rc_pace_to_cwnd = 1;
22878 			if (optval > 1)
22879 				rack->r_fill_less_agg = 1;
22880 		}
22881 		if ((optval >= rack_gp_rtt_maxmul) &&
22882 		    rack_gp_rtt_maxmul &&
22883 		    (optval < 0xf)) {
22884 			rack->rc_pace_fill_if_rttin_range = 1;
22885 			rack->rtt_limit_mul = optval;
22886 		} else {
22887 			rack->rc_pace_fill_if_rttin_range = 0;
22888 			rack->rtt_limit_mul = 0;
22889 		}
22890 		break;
22891 	case TCP_RACK_NO_PUSH_AT_MAX:
22892 		RACK_OPTS_INC(tcp_npush);
22893 		if (optval == 0)
22894 			rack->r_ctl.rc_no_push_at_mrtt = 0;
22895 		else if (optval < 0xff)
22896 			rack->r_ctl.rc_no_push_at_mrtt = optval;
22897 		else
22898 			error = EINVAL;
22899 		break;
22900 	case TCP_SHARED_CWND_ENABLE:
22901 		RACK_OPTS_INC(tcp_rack_scwnd);
22902 		if (optval == 0)
22903 			rack->rack_enable_scwnd = 0;
22904 		else
22905 			rack->rack_enable_scwnd = 1;
22906 		break;
22907 	case TCP_RACK_MBUF_QUEUE:
22908 		/* Now do we use the LRO mbuf-queue feature */
22909 		RACK_OPTS_INC(tcp_rack_mbufq);
22910 		if (optval || rack->r_use_cmp_ack)
22911 			rack->r_mbuf_queue = 1;
22912 		else
22913 			rack->r_mbuf_queue = 0;
22914 		if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
22915 			inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
22916 		else
22917 			inp->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
22918 		break;
22919 	case TCP_RACK_NONRXT_CFG_RATE:
22920 		RACK_OPTS_INC(tcp_rack_cfg_rate);
22921 		if (optval == 0)
22922 			rack->rack_rec_nonrxt_use_cr = 0;
22923 		else
22924 			rack->rack_rec_nonrxt_use_cr = 1;
22925 		break;
22926 	case TCP_NO_PRR:
22927 		RACK_OPTS_INC(tcp_rack_noprr);
22928 		if (optval == 0)
22929 			rack->rack_no_prr = 0;
22930 		else if (optval == 1)
22931 			rack->rack_no_prr = 1;
22932 		else if (optval == 2)
22933 			rack->no_prr_addback = 1;
22934 		else
22935 			error = EINVAL;
22936 		break;
22937 	case TCP_TIMELY_DYN_ADJ:
22938 		RACK_OPTS_INC(tcp_timely_dyn);
22939 		if (optval == 0)
22940 			rack->rc_gp_dyn_mul = 0;
22941 		else {
22942 			rack->rc_gp_dyn_mul = 1;
22943 			if (optval >= 100) {
22944 				/*
22945 				 * If the user sets something 100 or more
22946 				 * its the gp_ca value.
22947 				 */
22948 				rack->r_ctl.rack_per_of_gp_ca  = optval;
22949 			}
22950 		}
22951 		break;
22952 	case TCP_RACK_DO_DETECTION:
22953 		RACK_OPTS_INC(tcp_rack_do_detection);
22954 		if (optval == 0)
22955 			rack->do_detection = 0;
22956 		else
22957 			rack->do_detection = 1;
22958 		break;
22959 	case TCP_RACK_TLP_USE:
22960 		if ((optval < TLP_USE_ID) || (optval > TLP_USE_TWO_TWO)) {
22961 			error = EINVAL;
22962 			break;
22963 		}
22964 		RACK_OPTS_INC(tcp_tlp_use);
22965 		rack->rack_tlp_threshold_use = optval;
22966 		break;
22967 	case TCP_RACK_TLP_REDUCE:
22968 		/* RACK TLP cwnd reduction (bool) */
22969 		RACK_OPTS_INC(tcp_rack_tlp_reduce);
22970 		rack->r_ctl.rc_tlp_cwnd_reduce = optval;
22971 		break;
22972 		/*  Pacing related ones */
22973 	case TCP_RACK_PACE_ALWAYS:
22974 		/*
22975 		 * zero is old rack method, 1 is new
22976 		 * method using a pacing rate.
22977 		 */
22978 		RACK_OPTS_INC(tcp_rack_pace_always);
22979 		if (optval > 0) {
22980 			if (rack->rc_always_pace) {
22981 				error = EALREADY;
22982 				break;
22983 			} else if (tcp_can_enable_pacing()) {
22984 				rack->rc_always_pace = 1;
22985 				if ((rack->gp_ready) && (rack->use_fixed_rate == 0))
22986 					rack_set_cc_pacing(rack);
22987 			}
22988 			else {
22989 				error = ENOSPC;
22990 				break;
22991 			}
22992 		} else {
22993 			if (rack->rc_always_pace) {
22994 				tcp_decrement_paced_conn();
22995 				rack->rc_always_pace = 0;
22996 				rack_undo_cc_pacing(rack);
22997 			}
22998 		}
22999 		if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
23000 			inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
23001 		else
23002 			inp->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
23003 		/* A rate may be set irate or other, if so set seg size */
23004 		rack_update_seg(rack);
23005 		break;
23006 	case TCP_BBR_RACK_INIT_RATE:
23007 		RACK_OPTS_INC(tcp_initial_rate);
23008 		val = optval;
23009 		/* Change from kbits per second to bytes per second */
23010 		val *= 1000;
23011 		val /= 8;
23012 		rack->r_ctl.init_rate = val;
23013 		if (rack->rc_init_win != rack_default_init_window) {
23014 			uint32_t win, snt;
23015 
23016 			/*
23017 			 * Options don't always get applied
23018 			 * in the order you think. So in order
23019 			 * to assure we update a cwnd we need
23020 			 * to check and see if we are still
23021 			 * where we should raise the cwnd.
23022 			 */
23023 			win = rc_init_window(rack);
23024 			if (SEQ_GT(tp->snd_max, tp->iss))
23025 				snt = tp->snd_max - tp->iss;
23026 			else
23027 				snt = 0;
23028 			if ((snt < win) &&
23029 			    (tp->snd_cwnd < win))
23030 				tp->snd_cwnd = win;
23031 		}
23032 		if (rack->rc_always_pace)
23033 			rack_update_seg(rack);
23034 		break;
23035 	case TCP_BBR_IWINTSO:
23036 		RACK_OPTS_INC(tcp_initial_win);
23037 		if (optval && (optval <= 0xff)) {
23038 			uint32_t win, snt;
23039 
23040 			rack->rc_init_win = optval;
23041 			win = rc_init_window(rack);
23042 			if (SEQ_GT(tp->snd_max, tp->iss))
23043 				snt = tp->snd_max - tp->iss;
23044 			else
23045 				snt = 0;
23046 			if ((snt < win) &&
23047 			    (tp->t_srtt |
23048 			     rack->r_ctl.init_rate)) {
23049 				/*
23050 				 * We are not past the initial window
23051 				 * and we have some bases for pacing,
23052 				 * so we need to possibly adjust up
23053 				 * the cwnd. Note even if we don't set
23054 				 * the cwnd, its still ok to raise the rc_init_win
23055 				 * which can be used coming out of idle when we
23056 				 * would have a rate.
23057 				 */
23058 				if (tp->snd_cwnd < win)
23059 					tp->snd_cwnd = win;
23060 			}
23061 			if (rack->rc_always_pace)
23062 				rack_update_seg(rack);
23063 		} else
23064 			error = EINVAL;
23065 		break;
23066 	case TCP_RACK_FORCE_MSEG:
23067 		RACK_OPTS_INC(tcp_rack_force_max_seg);
23068 		if (optval)
23069 			rack->rc_force_max_seg = 1;
23070 		else
23071 			rack->rc_force_max_seg = 0;
23072 		break;
23073 	case TCP_RACK_PACE_MIN_SEG:
23074 		RACK_OPTS_INC(tcp_rack_min_seg);
23075 		rack->r_ctl.rc_user_set_min_segs = (0x0000ffff & optval);
23076 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
23077 		break;
23078 	case TCP_RACK_PACE_MAX_SEG:
23079 		/* Max segments size in a pace in bytes */
23080 		RACK_OPTS_INC(tcp_rack_max_seg);
23081 		rack->rc_user_set_max_segs = optval;
23082 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
23083 		break;
23084 	case TCP_RACK_PACE_RATE_REC:
23085 		/* Set the fixed pacing rate in Bytes per second ca */
23086 		RACK_OPTS_INC(tcp_rack_pace_rate_rec);
23087 		rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
23088 		if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
23089 			rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
23090 		if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
23091 			rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
23092 		rack->use_fixed_rate = 1;
23093 		if (rack->rc_always_pace && rack->gp_ready && rack->rack_hibeta)
23094 			rack_set_cc_pacing(rack);
23095 		rack_log_pacing_delay_calc(rack,
23096 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
23097 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
23098 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
23099 					   __LINE__, NULL,0);
23100 		break;
23101 
23102 	case TCP_RACK_PACE_RATE_SS:
23103 		/* Set the fixed pacing rate in Bytes per second ca */
23104 		RACK_OPTS_INC(tcp_rack_pace_rate_ss);
23105 		rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
23106 		if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
23107 			rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
23108 		if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
23109 			rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
23110 		rack->use_fixed_rate = 1;
23111 		if (rack->rc_always_pace && rack->gp_ready && rack->rack_hibeta)
23112 			rack_set_cc_pacing(rack);
23113 		rack_log_pacing_delay_calc(rack,
23114 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
23115 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
23116 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
23117 					   __LINE__, NULL, 0);
23118 		break;
23119 
23120 	case TCP_RACK_PACE_RATE_CA:
23121 		/* Set the fixed pacing rate in Bytes per second ca */
23122 		RACK_OPTS_INC(tcp_rack_pace_rate_ca);
23123 		rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
23124 		if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
23125 			rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
23126 		if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
23127 			rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
23128 		rack->use_fixed_rate = 1;
23129 		if (rack->rc_always_pace && rack->gp_ready && rack->rack_hibeta)
23130 			rack_set_cc_pacing(rack);
23131 		rack_log_pacing_delay_calc(rack,
23132 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
23133 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
23134 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
23135 					   __LINE__, NULL, 0);
23136 		break;
23137 	case TCP_RACK_GP_INCREASE_REC:
23138 		RACK_OPTS_INC(tcp_gp_inc_rec);
23139 		rack->r_ctl.rack_per_of_gp_rec = optval;
23140 		rack_log_pacing_delay_calc(rack,
23141 					   rack->r_ctl.rack_per_of_gp_ss,
23142 					   rack->r_ctl.rack_per_of_gp_ca,
23143 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
23144 					   __LINE__, NULL, 0);
23145 		break;
23146 	case TCP_RACK_GP_INCREASE_CA:
23147 		RACK_OPTS_INC(tcp_gp_inc_ca);
23148 		ca = optval;
23149 		if (ca < 100) {
23150 			/*
23151 			 * We don't allow any reduction
23152 			 * over the GP b/w.
23153 			 */
23154 			error = EINVAL;
23155 			break;
23156 		}
23157 		rack->r_ctl.rack_per_of_gp_ca = ca;
23158 		rack_log_pacing_delay_calc(rack,
23159 					   rack->r_ctl.rack_per_of_gp_ss,
23160 					   rack->r_ctl.rack_per_of_gp_ca,
23161 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
23162 					   __LINE__, NULL, 0);
23163 		break;
23164 	case TCP_RACK_GP_INCREASE_SS:
23165 		RACK_OPTS_INC(tcp_gp_inc_ss);
23166 		ss = optval;
23167 		if (ss < 100) {
23168 			/*
23169 			 * We don't allow any reduction
23170 			 * over the GP b/w.
23171 			 */
23172 			error = EINVAL;
23173 			break;
23174 		}
23175 		rack->r_ctl.rack_per_of_gp_ss = ss;
23176 		rack_log_pacing_delay_calc(rack,
23177 					   rack->r_ctl.rack_per_of_gp_ss,
23178 					   rack->r_ctl.rack_per_of_gp_ca,
23179 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
23180 					   __LINE__, NULL, 0);
23181 		break;
23182 	case TCP_RACK_RR_CONF:
23183 		RACK_OPTS_INC(tcp_rack_rrr_no_conf_rate);
23184 		if (optval && optval <= 3)
23185 			rack->r_rr_config = optval;
23186 		else
23187 			rack->r_rr_config = 0;
23188 		break;
23189 	case TCP_PACING_DND:			/*  URL:dnd */
23190 		if (optval > 0)
23191 			rack->rc_pace_dnd = 1;
23192 		else
23193 			rack->rc_pace_dnd = 0;
23194 		break;
23195 	case TCP_HDWR_RATE_CAP:
23196 		RACK_OPTS_INC(tcp_hdwr_rate_cap);
23197 		if (optval) {
23198 			if (rack->r_rack_hw_rate_caps == 0)
23199 				rack->r_rack_hw_rate_caps = 1;
23200 			else
23201 				error = EALREADY;
23202 		} else {
23203 			rack->r_rack_hw_rate_caps = 0;
23204 		}
23205 		break;
23206 	case TCP_RACK_SPLIT_LIMIT:
23207 		RACK_OPTS_INC(tcp_split_limit);
23208 		rack->r_ctl.rc_split_limit = optval;
23209 		break;
23210 	case TCP_BBR_HDWR_PACE:
23211 		RACK_OPTS_INC(tcp_hdwr_pacing);
23212 		if (optval){
23213 			if (rack->rack_hdrw_pacing == 0) {
23214 				rack->rack_hdw_pace_ena = 1;
23215 				rack->rack_attempt_hdwr_pace = 0;
23216 			} else
23217 				error = EALREADY;
23218 		} else {
23219 			rack->rack_hdw_pace_ena = 0;
23220 #ifdef RATELIMIT
23221 			if (rack->r_ctl.crte != NULL) {
23222 				rack->rack_hdrw_pacing = 0;
23223 				rack->rack_attempt_hdwr_pace = 0;
23224 				tcp_rel_pacing_rate(rack->r_ctl.crte, tp);
23225 				rack->r_ctl.crte = NULL;
23226 			}
23227 #endif
23228 		}
23229 		break;
23230 		/*  End Pacing related ones */
23231 	case TCP_RACK_PRR_SENDALOT:
23232 		/* Allow PRR to send more than one seg */
23233 		RACK_OPTS_INC(tcp_rack_prr_sendalot);
23234 		rack->r_ctl.rc_prr_sendalot = optval;
23235 		break;
23236 	case TCP_RACK_MIN_TO:
23237 		/* Minimum time between rack t-o's in ms */
23238 		RACK_OPTS_INC(tcp_rack_min_to);
23239 		rack->r_ctl.rc_min_to = optval;
23240 		break;
23241 	case TCP_RACK_EARLY_SEG:
23242 		/* If early recovery max segments */
23243 		RACK_OPTS_INC(tcp_rack_early_seg);
23244 		rack->r_ctl.rc_early_recovery_segs = optval;
23245 		break;
23246 	case TCP_RACK_ENABLE_HYSTART:
23247 	{
23248 		if (optval) {
23249 			tp->t_ccv.flags |= CCF_HYSTART_ALLOWED;
23250 			if (rack_do_hystart > RACK_HYSTART_ON)
23251 				tp->t_ccv.flags |= CCF_HYSTART_CAN_SH_CWND;
23252 			if (rack_do_hystart > RACK_HYSTART_ON_W_SC)
23253 				tp->t_ccv.flags |= CCF_HYSTART_CONS_SSTH;
23254 		} else {
23255 			tp->t_ccv.flags &= ~(CCF_HYSTART_ALLOWED|CCF_HYSTART_CAN_SH_CWND|CCF_HYSTART_CONS_SSTH);
23256 		}
23257 	}
23258 	break;
23259 	case TCP_RACK_REORD_THRESH:
23260 		/* RACK reorder threshold (shift amount) */
23261 		RACK_OPTS_INC(tcp_rack_reord_thresh);
23262 		if ((optval > 0) && (optval < 31))
23263 			rack->r_ctl.rc_reorder_shift = optval;
23264 		else
23265 			error = EINVAL;
23266 		break;
23267 	case TCP_RACK_REORD_FADE:
23268 		/* Does reordering fade after ms time */
23269 		RACK_OPTS_INC(tcp_rack_reord_fade);
23270 		rack->r_ctl.rc_reorder_fade = optval;
23271 		break;
23272 	case TCP_RACK_TLP_THRESH:
23273 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
23274 		RACK_OPTS_INC(tcp_rack_tlp_thresh);
23275 		if (optval)
23276 			rack->r_ctl.rc_tlp_threshold = optval;
23277 		else
23278 			error = EINVAL;
23279 		break;
23280 	case TCP_BBR_USE_RACK_RR:
23281 		RACK_OPTS_INC(tcp_rack_rr);
23282 		if (optval)
23283 			rack->use_rack_rr = 1;
23284 		else
23285 			rack->use_rack_rr = 0;
23286 		break;
23287 	case TCP_RACK_PKT_DELAY:
23288 		/* RACK added ms i.e. rack-rtt + reord + N */
23289 		RACK_OPTS_INC(tcp_rack_pkt_delay);
23290 		rack->r_ctl.rc_pkt_delay = optval;
23291 		break;
23292 	case TCP_DELACK:
23293 		RACK_OPTS_INC(tcp_rack_delayed_ack);
23294 		if (optval == 0)
23295 			tp->t_delayed_ack = 0;
23296 		else
23297 			tp->t_delayed_ack = 1;
23298 		if (tp->t_flags & TF_DELACK) {
23299 			tp->t_flags &= ~TF_DELACK;
23300 			tp->t_flags |= TF_ACKNOW;
23301 			NET_EPOCH_ENTER(et);
23302 			rack_output(tp);
23303 			NET_EPOCH_EXIT(et);
23304 		}
23305 		break;
23306 
23307 	case TCP_BBR_RACK_RTT_USE:
23308 		RACK_OPTS_INC(tcp_rack_rtt_use);
23309 		if ((optval != USE_RTT_HIGH) &&
23310 		    (optval != USE_RTT_LOW) &&
23311 		    (optval != USE_RTT_AVG))
23312 			error = EINVAL;
23313 		else
23314 			rack->r_ctl.rc_rate_sample_method = optval;
23315 		break;
23316 	case TCP_DATA_AFTER_CLOSE:
23317 		RACK_OPTS_INC(tcp_data_after_close);
23318 		if (optval)
23319 			rack->rc_allow_data_af_clo = 1;
23320 		else
23321 			rack->rc_allow_data_af_clo = 0;
23322 		break;
23323 	default:
23324 		break;
23325 	}
23326 	tcp_log_socket_option(tp, sopt_name, optval, error);
23327 	return (error);
23328 }
23329 
23330 
23331 static void
23332 rack_apply_deferred_options(struct tcp_rack *rack)
23333 {
23334 	struct deferred_opt_list *dol, *sdol;
23335 	uint32_t s_optval;
23336 
23337 	TAILQ_FOREACH_SAFE(dol, &rack->r_ctl.opt_list, next, sdol) {
23338 		TAILQ_REMOVE(&rack->r_ctl.opt_list, dol, next);
23339 		/* Disadvantage of deferal is you loose the error return */
23340 		s_optval = (uint32_t)dol->optval;
23341 		(void)rack_process_option(rack->rc_tp, rack, dol->optname, s_optval, dol->optval, NULL);
23342 		free(dol, M_TCPDO);
23343 	}
23344 }
23345 
23346 static void
23347 rack_hw_tls_change(struct tcpcb *tp, int chg)
23348 {
23349 	/* Update HW tls state */
23350 	struct tcp_rack *rack;
23351 
23352 	rack = (struct tcp_rack *)tp->t_fb_ptr;
23353 	if (chg)
23354 		rack->r_ctl.fsb.hw_tls = 1;
23355 	else
23356 		rack->r_ctl.fsb.hw_tls = 0;
23357 }
23358 
23359 static int
23360 rack_pru_options(struct tcpcb *tp, int flags)
23361 {
23362 	if (flags & PRUS_OOB)
23363 		return (EOPNOTSUPP);
23364 	return (0);
23365 }
23366 
23367 static bool
23368 rack_wake_check(struct tcpcb *tp)
23369 {
23370 	struct tcp_rack *rack;
23371 	struct timeval tv;
23372 	uint32_t cts;
23373 
23374 	rack = (struct tcp_rack *)tp->t_fb_ptr;
23375 	if (rack->r_ctl.rc_hpts_flags) {
23376 		cts = tcp_get_usecs(&tv);
23377 		if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == PACE_PKT_OUTPUT){
23378 			/*
23379 			 * Pacing timer is up, check if we are ready.
23380 			 */
23381 			if (TSTMP_GEQ(cts, rack->r_ctl.rc_last_output_to))
23382 				return (true);
23383 		} else if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) != 0) {
23384 			/*
23385 			 * A timer is up, check if we are ready.
23386 			 */
23387 			if (TSTMP_GEQ(cts, rack->r_ctl.rc_timer_exp))
23388 				return (true);
23389 		}
23390 	}
23391 	return (false);
23392 }
23393 
23394 static struct tcp_function_block __tcp_rack = {
23395 	.tfb_tcp_block_name = __XSTRING(STACKNAME),
23396 	.tfb_tcp_output = rack_output,
23397 	.tfb_do_queued_segments = ctf_do_queued_segments,
23398 	.tfb_do_segment_nounlock = rack_do_segment_nounlock,
23399 	.tfb_tcp_do_segment = rack_do_segment,
23400 	.tfb_tcp_ctloutput = rack_ctloutput,
23401 	.tfb_tcp_fb_init = rack_init,
23402 	.tfb_tcp_fb_fini = rack_fini,
23403 	.tfb_tcp_timer_stop_all = rack_stopall,
23404 	.tfb_tcp_rexmit_tmr = rack_remxt_tmr,
23405 	.tfb_tcp_handoff_ok = rack_handoff_ok,
23406 	.tfb_tcp_mtu_chg = rack_mtu_change,
23407 	.tfb_pru_options = rack_pru_options,
23408 	.tfb_hwtls_change = rack_hw_tls_change,
23409 	.tfb_chg_query = rack_chg_query,
23410 	.tfb_switch_failed = rack_switch_failed,
23411 	.tfb_early_wake_check = rack_wake_check,
23412 	.tfb_compute_pipe = rack_compute_pipe,
23413 	.tfb_flags = TCP_FUNC_OUTPUT_CANDROP,
23414 };
23415 
23416 /*
23417  * rack_ctloutput() must drop the inpcb lock before performing copyin on
23418  * socket option arguments.  When it re-acquires the lock after the copy, it
23419  * has to revalidate that the connection is still valid for the socket
23420  * option.
23421  */
23422 static int
23423 rack_set_sockopt(struct tcpcb *tp, struct sockopt *sopt)
23424 {
23425 	struct inpcb *inp = tptoinpcb(tp);
23426 #ifdef INET6
23427 	struct ip6_hdr *ip6;
23428 	int32_t mask, tclass;
23429 #endif
23430 #ifdef INET
23431 	struct ip *ip;
23432 #endif
23433 	struct tcp_rack *rack;
23434 	struct tcp_hybrid_req hybrid;
23435 	uint64_t loptval;
23436 	int32_t error = 0, optval;
23437 
23438 	rack = (struct tcp_rack *)tp->t_fb_ptr;
23439 	if (rack == NULL) {
23440 		INP_WUNLOCK(inp);
23441 		return (EINVAL);
23442 	}
23443 #ifdef INET6
23444 	ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
23445 #endif
23446 #ifdef INET
23447 	ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
23448 #endif
23449 
23450 	switch (sopt->sopt_level) {
23451 #ifdef INET6
23452 	case IPPROTO_IPV6:
23453 		MPASS(inp->inp_vflag & INP_IPV6PROTO);
23454 		switch (sopt->sopt_name) {
23455 		case IPV6_USE_MIN_MTU:
23456 			tcp6_use_min_mtu(tp);
23457 			break;
23458 		case IPV6_TCLASS:
23459 			/*
23460 			 * The DSCP codepoint has changed, update the fsb
23461 			 * by overwriting any previous traffic class.
23462 			 */
23463 			if (inp->in6p_outputopts) {
23464 				mask = 0xfc;
23465 				tclass = inp->in6p_outputopts->ip6po_tclass;
23466 				ip6->ip6_flow &= htonl((~mask) << 20);
23467 				ip6->ip6_flow |= htonl((tclass & mask) << 20);
23468 			}
23469 			break;
23470 		}
23471 		INP_WUNLOCK(inp);
23472 		return (0);
23473 #endif
23474 #ifdef INET
23475 	case IPPROTO_IP:
23476 		switch (sopt->sopt_name) {
23477 		case IP_TOS:
23478 			/*
23479 			 * The DSCP codepoint has changed, update the fsb.
23480 			 */
23481 			ip->ip_tos = rack->rc_inp->inp_ip_tos;
23482 			break;
23483 		case IP_TTL:
23484 			/*
23485 			 * The TTL has changed, update the fsb.
23486 			 */
23487 			ip->ip_ttl = rack->rc_inp->inp_ip_ttl;
23488 			break;
23489 		}
23490 		INP_WUNLOCK(inp);
23491 		return (0);
23492 #endif
23493 #ifdef SO_PEERPRIO
23494 	case SOL_SOCKET:
23495 		switch (sopt->sopt_name) {
23496 		case SO_PEERPRIO:			/*  SC-URL:bs */
23497 			/* Already read in and sanity checked in sosetopt(). */
23498 			if (inp->inp_socket) {
23499 				rack->client_bufferlvl = inp->inp_socket->so_peerprio;
23500 				rack_client_buffer_level_set(rack);
23501 			}
23502 			break;
23503 		}
23504 		INP_WUNLOCK(inp);
23505 		return (0);
23506 #endif
23507 	case IPPROTO_TCP:
23508 		switch (sopt->sopt_name) {
23509 		case TCP_RACK_TLP_REDUCE:		/*  URL:tlp_reduce */
23510 		/*  Pacing related ones */
23511 		case TCP_RACK_PACE_ALWAYS:		/*  URL:pace_always */
23512 		case TCP_BBR_RACK_INIT_RATE:		/*  URL:irate */
23513 		case TCP_BBR_IWINTSO:			/*  URL:tso_iwin */
23514 		case TCP_RACK_PACE_MIN_SEG:		/*  URL:pace_min_seg */
23515 		case TCP_RACK_PACE_MAX_SEG:		/*  URL:pace_max_seg */
23516 		case TCP_RACK_FORCE_MSEG:		/*  URL:force_max_seg */
23517 		case TCP_RACK_PACE_RATE_CA:		/*  URL:pr_ca */
23518 		case TCP_RACK_PACE_RATE_SS:		/*  URL:pr_ss*/
23519 		case TCP_RACK_PACE_RATE_REC:		/*  URL:pr_rec */
23520 		case TCP_RACK_GP_INCREASE_CA:		/*  URL:gp_inc_ca */
23521 		case TCP_RACK_GP_INCREASE_SS:		/*  URL:gp_inc_ss */
23522 		case TCP_RACK_GP_INCREASE_REC:		/*  URL:gp_inc_rec */
23523 		case TCP_RACK_RR_CONF:			/*  URL:rrr_conf */
23524 		case TCP_BBR_HDWR_PACE:			/*  URL:hdwrpace */
23525 		case TCP_HDWR_RATE_CAP:			/*  URL:hdwrcap boolean */
23526 		case TCP_PACING_RATE_CAP:		/*  URL:cap  -- used by side-channel */
23527 		case TCP_HDWR_UP_ONLY:			/*  URL:uponly -- hardware pacing  boolean */
23528 		case TCP_RACK_PACING_BETA:		/*  URL:pacing_beta */
23529 		case TCP_RACK_PACING_BETA_ECN:		/*  URL:pacing_beta_ecn */
23530 		case TCP_RACK_PACE_TO_FILL:		/*  URL:fillcw */
23531 		case TCP_RACK_DGP_IN_REC:		/*  URL:dgpinrec */
23532 			/* End pacing related */
23533 		case TCP_RXT_CLAMP:			/*  URL:rxtclamp */
23534 		case TCP_DELACK:			/*  URL:delack (in base TCP i.e. tcp_hints along with cc etc ) */
23535 		case TCP_RACK_PRR_SENDALOT:		/*  URL:prr_sendalot */
23536 		case TCP_RACK_MIN_TO:			/*  URL:min_to */
23537 		case TCP_RACK_EARLY_SEG:		/*  URL:early_seg */
23538 		case TCP_RACK_REORD_THRESH:		/*  URL:reord_thresh */
23539 		case TCP_RACK_REORD_FADE:		/*  URL:reord_fade */
23540 		case TCP_RACK_TLP_THRESH:		/*  URL:tlp_thresh */
23541 		case TCP_RACK_PKT_DELAY:		/*  URL:pkt_delay */
23542 		case TCP_RACK_TLP_USE:			/*  URL:tlp_use */
23543 		case TCP_BBR_RACK_RTT_USE:		/*  URL:rttuse */
23544 		case TCP_BBR_USE_RACK_RR:		/*  URL:rackrr */
23545 		case TCP_RACK_DO_DETECTION:		/*  URL:detect */
23546 		case TCP_NO_PRR:			/*  URL:noprr */
23547 		case TCP_TIMELY_DYN_ADJ:      		/*  URL:dynamic */
23548 		case TCP_DATA_AFTER_CLOSE:		/*  no URL */
23549 		case TCP_RACK_NONRXT_CFG_RATE:		/*  URL:nonrxtcr */
23550 		case TCP_SHARED_CWND_ENABLE:		/*  URL:scwnd */
23551 		case TCP_RACK_MBUF_QUEUE:		/*  URL:mqueue */
23552 		case TCP_RACK_NO_PUSH_AT_MAX:		/*  URL:npush */
23553 		case TCP_SHARED_CWND_TIME_LIMIT:	/*  URL:lscwnd */
23554 		case TCP_RACK_PROFILE:			/*  URL:profile */
23555 		case TCP_HYBRID_PACING:			/*  URL:hybrid */
23556 		case TCP_USE_CMP_ACKS:			/*  URL:cmpack */
23557 		case TCP_RACK_ABC_VAL:			/*  URL:labc */
23558 		case TCP_REC_ABC_VAL:			/*  URL:reclabc */
23559 		case TCP_RACK_MEASURE_CNT:		/*  URL:measurecnt */
23560 		case TCP_DEFER_OPTIONS:			/*  URL:defer */
23561 		case TCP_RACK_DSACK_OPT:		/*  URL:dsack */
23562 		case TCP_RACK_TIMER_SLOP:		/*  URL:timer_slop */
23563 		case TCP_RACK_ENABLE_HYSTART:		/*  URL:hystart */
23564 		case TCP_RACK_SET_RXT_OPTIONS:		/*  URL:rxtsz */
23565 		case TCP_RACK_HI_BETA:			/*  URL:hibeta */
23566 		case TCP_RACK_SPLIT_LIMIT:		/*  URL:split */
23567 		case TCP_RACK_PACING_DIVISOR:		/*  URL:divisor */
23568 		case TCP_PACING_DND:			/*  URL:dnd */
23569 			goto process_opt;
23570 			break;
23571 		default:
23572 			/* Filter off all unknown options to the base stack */
23573 			return (tcp_default_ctloutput(tp, sopt));
23574 			break;
23575 		}
23576 
23577 	default:
23578 		INP_WUNLOCK(inp);
23579 		return (0);
23580 	}
23581 process_opt:
23582 	INP_WUNLOCK(inp);
23583 	if (sopt->sopt_name == TCP_PACING_RATE_CAP) {
23584 		error = sooptcopyin(sopt, &loptval, sizeof(loptval), sizeof(loptval));
23585 		/*
23586 		 * We truncate it down to 32 bits for the socket-option trace this
23587 		 * means rates > 34Gbps won't show right, but thats probably ok.
23588 		 */
23589 		optval = (uint32_t)loptval;
23590 	} else if (sopt->sopt_name == TCP_HYBRID_PACING) {
23591 		error = sooptcopyin(sopt, &hybrid, sizeof(hybrid), sizeof(hybrid));
23592 	} else {
23593 		error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval));
23594 		/* Save it in 64 bit form too */
23595 		loptval = optval;
23596 	}
23597 	if (error)
23598 		return (error);
23599 	INP_WLOCK(inp);
23600 	if (tp->t_fb != &__tcp_rack) {
23601 		INP_WUNLOCK(inp);
23602 		return (ENOPROTOOPT);
23603 	}
23604 	if (rack->defer_options && (rack->gp_ready == 0) &&
23605 	    (sopt->sopt_name != TCP_DEFER_OPTIONS) &&
23606 	    (sopt->sopt_name != TCP_HYBRID_PACING) &&
23607 	    (sopt->sopt_name != TCP_RACK_PACING_BETA) &&
23608 	    (sopt->sopt_name != TCP_RACK_SET_RXT_OPTIONS) &&
23609 	    (sopt->sopt_name != TCP_RACK_PACING_BETA_ECN) &&
23610 	    (sopt->sopt_name != TCP_RACK_MEASURE_CNT)) {
23611 		/* Options are beind deferred */
23612 		if (rack_add_deferred_option(rack, sopt->sopt_name, loptval)) {
23613 			INP_WUNLOCK(inp);
23614 			return (0);
23615 		} else {
23616 			/* No memory to defer, fail */
23617 			INP_WUNLOCK(inp);
23618 			return (ENOMEM);
23619 		}
23620 	}
23621 	error = rack_process_option(tp, rack, sopt->sopt_name, optval, loptval, &hybrid);
23622 	INP_WUNLOCK(inp);
23623 	return (error);
23624 }
23625 
23626 static void
23627 rack_fill_info(struct tcpcb *tp, struct tcp_info *ti)
23628 {
23629 
23630 	INP_WLOCK_ASSERT(tptoinpcb(tp));
23631 	bzero(ti, sizeof(*ti));
23632 
23633 	ti->tcpi_state = tp->t_state;
23634 	if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
23635 		ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
23636 	if (tp->t_flags & TF_SACK_PERMIT)
23637 		ti->tcpi_options |= TCPI_OPT_SACK;
23638 	if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
23639 		ti->tcpi_options |= TCPI_OPT_WSCALE;
23640 		ti->tcpi_snd_wscale = tp->snd_scale;
23641 		ti->tcpi_rcv_wscale = tp->rcv_scale;
23642 	}
23643 	if (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))
23644 		ti->tcpi_options |= TCPI_OPT_ECN;
23645 	if (tp->t_flags & TF_FASTOPEN)
23646 		ti->tcpi_options |= TCPI_OPT_TFO;
23647 	/* still kept in ticks is t_rcvtime */
23648 	ti->tcpi_last_data_recv = ((uint32_t)ticks - tp->t_rcvtime) * tick;
23649 	/* Since we hold everything in precise useconds this is easy */
23650 	ti->tcpi_rtt = tp->t_srtt;
23651 	ti->tcpi_rttvar = tp->t_rttvar;
23652 	ti->tcpi_rto = tp->t_rxtcur;
23653 	ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
23654 	ti->tcpi_snd_cwnd = tp->snd_cwnd;
23655 	/*
23656 	 * FreeBSD-specific extension fields for tcp_info.
23657 	 */
23658 	ti->tcpi_rcv_space = tp->rcv_wnd;
23659 	ti->tcpi_rcv_nxt = tp->rcv_nxt;
23660 	ti->tcpi_snd_wnd = tp->snd_wnd;
23661 	ti->tcpi_snd_bwnd = 0;		/* Unused, kept for compat. */
23662 	ti->tcpi_snd_nxt = tp->snd_nxt;
23663 	ti->tcpi_snd_mss = tp->t_maxseg;
23664 	ti->tcpi_rcv_mss = tp->t_maxseg;
23665 	ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;
23666 	ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
23667 	ti->tcpi_snd_zerowin = tp->t_sndzerowin;
23668 	ti->tcpi_total_tlp = tp->t_sndtlppack;
23669 	ti->tcpi_total_tlp_bytes = tp->t_sndtlpbyte;
23670 #ifdef NETFLIX_STATS
23671 	memcpy(&ti->tcpi_rxsyninfo, &tp->t_rxsyninfo, sizeof(struct tcpsyninfo));
23672 #endif
23673 #ifdef TCP_OFFLOAD
23674 	if (tp->t_flags & TF_TOE) {
23675 		ti->tcpi_options |= TCPI_OPT_TOE;
23676 		tcp_offload_tcp_info(tp, ti);
23677 	}
23678 #endif
23679 }
23680 
23681 static int
23682 rack_get_sockopt(struct tcpcb *tp, struct sockopt *sopt)
23683 {
23684 	struct inpcb *inp = tptoinpcb(tp);
23685 	struct tcp_rack *rack;
23686 	int32_t error, optval;
23687 	uint64_t val, loptval;
23688 	struct	tcp_info ti;
23689 	/*
23690 	 * Because all our options are either boolean or an int, we can just
23691 	 * pull everything into optval and then unlock and copy. If we ever
23692 	 * add a option that is not a int, then this will have quite an
23693 	 * impact to this routine.
23694 	 */
23695 	error = 0;
23696 	rack = (struct tcp_rack *)tp->t_fb_ptr;
23697 	if (rack == NULL) {
23698 		INP_WUNLOCK(inp);
23699 		return (EINVAL);
23700 	}
23701 	switch (sopt->sopt_name) {
23702 	case TCP_INFO:
23703 		/* First get the info filled */
23704 		rack_fill_info(tp, &ti);
23705 		/* Fix up the rtt related fields if needed */
23706 		INP_WUNLOCK(inp);
23707 		error = sooptcopyout(sopt, &ti, sizeof ti);
23708 		return (error);
23709 	/*
23710 	 * Beta is the congestion control value for NewReno that influences how
23711 	 * much of a backoff happens when loss is detected. It is normally set
23712 	 * to 50 for 50% i.e. the cwnd is reduced to 50% of its previous value
23713 	 * when you exit recovery.
23714 	 */
23715 	case TCP_RACK_PACING_BETA:
23716 		if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0)
23717 			error = EINVAL;
23718 		else if (rack->rc_pacing_cc_set == 0)
23719 			optval = rack->r_ctl.rc_saved_beta.beta;
23720 		else {
23721 			/*
23722 			 * Reach out into the CC data and report back what
23723 			 * I have previously set. Yeah it looks hackish but
23724 			 * we don't want to report the saved values.
23725 			 */
23726 			if (tp->t_ccv.cc_data)
23727 				optval = ((struct newreno *)tp->t_ccv.cc_data)->beta;
23728 			else
23729 				error = EINVAL;
23730 		}
23731 		break;
23732 		/*
23733 		 * Beta_ecn is the congestion control value for NewReno that influences how
23734 		 * much of a backoff happens when a ECN mark is detected. It is normally set
23735 		 * to 80 for 80% i.e. the cwnd is reduced by 20% of its previous value when
23736 		 * you exit recovery. Note that classic ECN has a beta of 50, it is only
23737 		 * ABE Ecn that uses this "less" value, but we do too with pacing :)
23738 		 */
23739 
23740 	case TCP_RACK_PACING_BETA_ECN:
23741 		if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0)
23742 			error = EINVAL;
23743 		else if (rack->rc_pacing_cc_set == 0)
23744 			optval = rack->r_ctl.rc_saved_beta.beta_ecn;
23745 		else {
23746 			/*
23747 			 * Reach out into the CC data and report back what
23748 			 * I have previously set. Yeah it looks hackish but
23749 			 * we don't want to report the saved values.
23750 			 */
23751 			if (tp->t_ccv.cc_data)
23752 				optval = ((struct newreno *)tp->t_ccv.cc_data)->beta_ecn;
23753 			else
23754 				error = EINVAL;
23755 		}
23756 		break;
23757 	case TCP_RACK_DSACK_OPT:
23758 		optval = 0;
23759 		if (rack->rc_rack_tmr_std_based) {
23760 			optval |= 1;
23761 		}
23762 		if (rack->rc_rack_use_dsack) {
23763 			optval |= 2;
23764 		}
23765 		break;
23766  	case TCP_RACK_ENABLE_HYSTART:
23767 	{
23768 		if (tp->t_ccv.flags & CCF_HYSTART_ALLOWED) {
23769 			optval = RACK_HYSTART_ON;
23770 			if (tp->t_ccv.flags & CCF_HYSTART_CAN_SH_CWND)
23771 				optval = RACK_HYSTART_ON_W_SC;
23772 			if (tp->t_ccv.flags & CCF_HYSTART_CONS_SSTH)
23773 				optval = RACK_HYSTART_ON_W_SC_C;
23774 		} else {
23775 			optval = RACK_HYSTART_OFF;
23776 		}
23777 	}
23778 	break;
23779 	case TCP_RACK_DGP_IN_REC:
23780 		optval = rack->r_ctl.full_dgp_in_rec;
23781 		break;
23782 	case TCP_RACK_HI_BETA:
23783 		optval = rack->rack_hibeta;
23784 		break;
23785 	case TCP_RXT_CLAMP:
23786 		optval = rack->r_ctl.saved_rxt_clamp_val;
23787 		break;
23788 	case TCP_DEFER_OPTIONS:
23789 		optval = rack->defer_options;
23790 		break;
23791 	case TCP_RACK_MEASURE_CNT:
23792 		optval = rack->r_ctl.req_measurements;
23793 		break;
23794 	case TCP_REC_ABC_VAL:
23795 		optval = rack->r_use_labc_for_rec;
23796 		break;
23797 	case TCP_RACK_ABC_VAL:
23798 		optval = rack->rc_labc;
23799 		break;
23800 	case TCP_HDWR_UP_ONLY:
23801 		optval= rack->r_up_only;
23802 		break;
23803 	case TCP_PACING_RATE_CAP:
23804 		loptval = rack->r_ctl.bw_rate_cap;
23805 		break;
23806 	case TCP_RACK_PROFILE:
23807 		/* You cannot retrieve a profile, its write only */
23808 		error = EINVAL;
23809 		break;
23810 	case TCP_HYBRID_PACING:
23811 		/* You cannot retrieve hybrid pacing information, its write only */
23812 		error = EINVAL;
23813 		break;
23814 	case TCP_USE_CMP_ACKS:
23815 		optval = rack->r_use_cmp_ack;
23816 		break;
23817 	case TCP_RACK_PACE_TO_FILL:
23818 		optval = rack->rc_pace_to_cwnd;
23819 		if (optval && rack->r_fill_less_agg)
23820 			optval++;
23821 		break;
23822 	case TCP_RACK_NO_PUSH_AT_MAX:
23823 		optval = rack->r_ctl.rc_no_push_at_mrtt;
23824 		break;
23825 	case TCP_SHARED_CWND_ENABLE:
23826 		optval = rack->rack_enable_scwnd;
23827 		break;
23828 	case TCP_RACK_NONRXT_CFG_RATE:
23829 		optval = rack->rack_rec_nonrxt_use_cr;
23830 		break;
23831 	case TCP_NO_PRR:
23832 		if (rack->rack_no_prr  == 1)
23833 			optval = 1;
23834 		else if (rack->no_prr_addback == 1)
23835 			optval = 2;
23836 		else
23837 			optval = 0;
23838 		break;
23839 	case TCP_RACK_DO_DETECTION:
23840 		optval = rack->do_detection;
23841 		break;
23842 	case TCP_RACK_MBUF_QUEUE:
23843 		/* Now do we use the LRO mbuf-queue feature */
23844 		optval = rack->r_mbuf_queue;
23845 		break;
23846 	case TCP_TIMELY_DYN_ADJ:
23847 		optval = rack->rc_gp_dyn_mul;
23848 		break;
23849 	case TCP_BBR_IWINTSO:
23850 		optval = rack->rc_init_win;
23851 		break;
23852 	case TCP_RACK_TLP_REDUCE:
23853 		/* RACK TLP cwnd reduction (bool) */
23854 		optval = rack->r_ctl.rc_tlp_cwnd_reduce;
23855 		break;
23856 	case TCP_BBR_RACK_INIT_RATE:
23857 		val = rack->r_ctl.init_rate;
23858 		/* convert to kbits per sec */
23859 		val *= 8;
23860 		val /= 1000;
23861 		optval = (uint32_t)val;
23862 		break;
23863 	case TCP_RACK_FORCE_MSEG:
23864 		optval = rack->rc_force_max_seg;
23865 		break;
23866 	case TCP_RACK_PACE_MIN_SEG:
23867 		optval = rack->r_ctl.rc_user_set_min_segs;
23868 		break;
23869 	case TCP_RACK_PACE_MAX_SEG:
23870 		/* Max segments in a pace */
23871 		optval = rack->rc_user_set_max_segs;
23872 		break;
23873 	case TCP_RACK_PACE_ALWAYS:
23874 		/* Use the always pace method */
23875 		optval = rack->rc_always_pace;
23876 		break;
23877 	case TCP_RACK_PRR_SENDALOT:
23878 		/* Allow PRR to send more than one seg */
23879 		optval = rack->r_ctl.rc_prr_sendalot;
23880 		break;
23881 	case TCP_RACK_MIN_TO:
23882 		/* Minimum time between rack t-o's in ms */
23883 		optval = rack->r_ctl.rc_min_to;
23884 		break;
23885 	case TCP_RACK_SPLIT_LIMIT:
23886 		optval = rack->r_ctl.rc_split_limit;
23887 		break;
23888 	case TCP_RACK_EARLY_SEG:
23889 		/* If early recovery max segments */
23890 		optval = rack->r_ctl.rc_early_recovery_segs;
23891 		break;
23892 	case TCP_RACK_REORD_THRESH:
23893 		/* RACK reorder threshold (shift amount) */
23894 		optval = rack->r_ctl.rc_reorder_shift;
23895 		break;
23896 	case TCP_RACK_REORD_FADE:
23897 		/* Does reordering fade after ms time */
23898 		optval = rack->r_ctl.rc_reorder_fade;
23899 		break;
23900 	case TCP_BBR_USE_RACK_RR:
23901 		/* Do we use the rack cheat for rxt */
23902 		optval = rack->use_rack_rr;
23903 		break;
23904 	case TCP_RACK_RR_CONF:
23905 		optval = rack->r_rr_config;
23906 		break;
23907 	case TCP_HDWR_RATE_CAP:
23908 		optval = rack->r_rack_hw_rate_caps;
23909 		break;
23910 	case TCP_BBR_HDWR_PACE:
23911 		optval = rack->rack_hdw_pace_ena;
23912 		break;
23913 	case TCP_RACK_TLP_THRESH:
23914 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
23915 		optval = rack->r_ctl.rc_tlp_threshold;
23916 		break;
23917 	case TCP_RACK_PKT_DELAY:
23918 		/* RACK added ms i.e. rack-rtt + reord + N */
23919 		optval = rack->r_ctl.rc_pkt_delay;
23920 		break;
23921 	case TCP_RACK_TLP_USE:
23922 		optval = rack->rack_tlp_threshold_use;
23923 		break;
23924 	case TCP_PACING_DND:
23925 		optval = rack->rc_pace_dnd;
23926 		break;
23927 	case TCP_RACK_PACE_RATE_CA:
23928 		optval = rack->r_ctl.rc_fixed_pacing_rate_ca;
23929 		break;
23930 	case TCP_RACK_PACE_RATE_SS:
23931 		optval = rack->r_ctl.rc_fixed_pacing_rate_ss;
23932 		break;
23933 	case TCP_RACK_PACE_RATE_REC:
23934 		optval = rack->r_ctl.rc_fixed_pacing_rate_rec;
23935 		break;
23936 	case TCP_RACK_GP_INCREASE_SS:
23937 		optval = rack->r_ctl.rack_per_of_gp_ca;
23938 		break;
23939 	case TCP_RACK_GP_INCREASE_CA:
23940 		optval = rack->r_ctl.rack_per_of_gp_ss;
23941 		break;
23942 	case TCP_RACK_PACING_DIVISOR:
23943 		optval = rack->r_ctl.pace_len_divisor;
23944 		break;
23945 	case TCP_BBR_RACK_RTT_USE:
23946 		optval = rack->r_ctl.rc_rate_sample_method;
23947 		break;
23948 	case TCP_DELACK:
23949 		optval = tp->t_delayed_ack;
23950 		break;
23951 	case TCP_DATA_AFTER_CLOSE:
23952 		optval = rack->rc_allow_data_af_clo;
23953 		break;
23954 	case TCP_SHARED_CWND_TIME_LIMIT:
23955 		optval = rack->r_limit_scw;
23956 		break;
23957 	case TCP_RACK_TIMER_SLOP:
23958 		optval = rack->r_ctl.timer_slop;
23959 		break;
23960 	default:
23961 		return (tcp_default_ctloutput(tp, sopt));
23962 		break;
23963 	}
23964 	INP_WUNLOCK(inp);
23965 	if (error == 0) {
23966 		if (TCP_PACING_RATE_CAP)
23967 			error = sooptcopyout(sopt, &loptval, sizeof loptval);
23968 		else
23969 			error = sooptcopyout(sopt, &optval, sizeof optval);
23970 	}
23971 	return (error);
23972 }
23973 
23974 static int
23975 rack_ctloutput(struct tcpcb *tp, struct sockopt *sopt)
23976 {
23977 	if (sopt->sopt_dir == SOPT_SET) {
23978 		return (rack_set_sockopt(tp, sopt));
23979 	} else if (sopt->sopt_dir == SOPT_GET) {
23980 		return (rack_get_sockopt(tp, sopt));
23981 	} else {
23982 		panic("%s: sopt_dir $%d", __func__, sopt->sopt_dir);
23983 	}
23984 }
23985 
23986 static const char *rack_stack_names[] = {
23987 	__XSTRING(STACKNAME),
23988 #ifdef STACKALIAS
23989 	__XSTRING(STACKALIAS),
23990 #endif
23991 };
23992 
23993 static int
23994 rack_ctor(void *mem, int32_t size, void *arg, int32_t how)
23995 {
23996 	memset(mem, 0, size);
23997 	return (0);
23998 }
23999 
24000 static void
24001 rack_dtor(void *mem, int32_t size, void *arg)
24002 {
24003 
24004 }
24005 
24006 static bool rack_mod_inited = false;
24007 
24008 static int
24009 tcp_addrack(module_t mod, int32_t type, void *data)
24010 {
24011 	int32_t err = 0;
24012 	int num_stacks;
24013 
24014 	switch (type) {
24015 	case MOD_LOAD:
24016 		rack_zone = uma_zcreate(__XSTRING(MODNAME) "_map",
24017 		    sizeof(struct rack_sendmap),
24018 		    rack_ctor, rack_dtor, NULL, NULL, UMA_ALIGN_PTR, 0);
24019 
24020 		rack_pcb_zone = uma_zcreate(__XSTRING(MODNAME) "_pcb",
24021 		    sizeof(struct tcp_rack),
24022 		    rack_ctor, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
24023 
24024 		sysctl_ctx_init(&rack_sysctl_ctx);
24025 		rack_sysctl_root = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
24026 		    SYSCTL_STATIC_CHILDREN(_net_inet_tcp),
24027 		    OID_AUTO,
24028 #ifdef STACKALIAS
24029 		    __XSTRING(STACKALIAS),
24030 #else
24031 		    __XSTRING(STACKNAME),
24032 #endif
24033 		    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
24034 		    "");
24035 		if (rack_sysctl_root == NULL) {
24036 			printf("Failed to add sysctl node\n");
24037 			err = EFAULT;
24038 			goto free_uma;
24039 		}
24040 		rack_init_sysctls();
24041 		num_stacks = nitems(rack_stack_names);
24042 		err = register_tcp_functions_as_names(&__tcp_rack, M_WAITOK,
24043 		    rack_stack_names, &num_stacks);
24044 		if (err) {
24045 			printf("Failed to register %s stack name for "
24046 			    "%s module\n", rack_stack_names[num_stacks],
24047 			    __XSTRING(MODNAME));
24048 			sysctl_ctx_free(&rack_sysctl_ctx);
24049 free_uma:
24050 			uma_zdestroy(rack_zone);
24051 			uma_zdestroy(rack_pcb_zone);
24052 			rack_counter_destroy();
24053 			printf("Failed to register rack module -- err:%d\n", err);
24054 			return (err);
24055 		}
24056 		tcp_lro_reg_mbufq();
24057 		rack_mod_inited = true;
24058 		break;
24059 	case MOD_QUIESCE:
24060 		err = deregister_tcp_functions(&__tcp_rack, true, false);
24061 		break;
24062 	case MOD_UNLOAD:
24063 		err = deregister_tcp_functions(&__tcp_rack, false, true);
24064 		if (err == EBUSY)
24065 			break;
24066 		if (rack_mod_inited) {
24067 			uma_zdestroy(rack_zone);
24068 			uma_zdestroy(rack_pcb_zone);
24069 			sysctl_ctx_free(&rack_sysctl_ctx);
24070 			rack_counter_destroy();
24071 			rack_mod_inited = false;
24072 		}
24073 		tcp_lro_dereg_mbufq();
24074 		err = 0;
24075 		break;
24076 	default:
24077 		return (EOPNOTSUPP);
24078 	}
24079 	return (err);
24080 }
24081 
24082 static moduledata_t tcp_rack = {
24083 	.name = __XSTRING(MODNAME),
24084 	.evhand = tcp_addrack,
24085 	.priv = 0
24086 };
24087 
24088 MODULE_VERSION(MODNAME, 1);
24089 DECLARE_MODULE(MODNAME, tcp_rack, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
24090 MODULE_DEPEND(MODNAME, tcphpts, 1, 1, 1);
24091 
24092 #endif /* #if !defined(INET) && !defined(INET6) */
24093