xref: /freebsd/sys/netinet/tcp_stacks/rack.c (revision d411c1d6) 
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 		/*
1982 		 * The very noisy two need to only come out when
1983 		 * we have verbose logging on.
1984 		 */
1985 		if (rack_verbose_logging != 0)
1986 			do_log = tcp_bblogging_on(rack->rc_tp);
1987 		else
1988 			do_log = 0;
1989 	} else if (mod != HYBRID_LOG_BW_MEASURE) {
1990 		/*
1991 		 * All other less noisy logs here except the measure which
1992 		 * also needs to come out on the point and the log.
1993 		 */
1994 		do_log = tcp_bblogging_on(rack->rc_tp);
1995 	} else {
1996 		do_log = tcp_bblogging_point_on(rack->rc_tp, TCP_BBPOINT_REQ_LEVEL_LOGGING);
1997 	}
1998 
1999 	if (do_log) {
2000 		union tcp_log_stackspecific log;
2001 		struct timeval tv;
2002 		uint64_t lt_bw;
2003 
2004 		/* Convert our ms to a microsecond */
2005 		memset(&log, 0, sizeof(log));
2006 
2007 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2008 		log.u_bbr.rttProp = tim;
2009 		log.u_bbr.bw_inuse = cbw;
2010 		log.u_bbr.delRate = rack_get_gp_est(rack);
2011 		lt_bw = rack_get_lt_bw(rack);
2012 		log.u_bbr.flex1 = seq;
2013 		log.u_bbr.pacing_gain = aux;
2014 		/* lt_bw = < flex3 | flex2 > */
2015 		log.u_bbr.flex2 = (uint32_t)(lt_bw & 0x00000000ffffffff);
2016 		log.u_bbr.flex3 = (uint32_t)((lt_bw >> 32) & 0x00000000ffffffff);
2017 		/* Record the last obtained us rtt in inflight */
2018 		if (cur == NULL) {
2019 			/* Make sure we are looking at the right log if an overide comes in */
2020 			cur = rack->r_ctl.rc_last_sft;
2021 		}
2022 		if (rack->r_ctl.rack_rs.rs_flags != RACK_RTT_EMPTY)
2023 			log.u_bbr.inflight = rack->r_ctl.rack_rs.rs_us_rtt;
2024 		else {
2025 			/* Use the last known rtt i.e. the rack-rtt */
2026 			log.u_bbr.inflight = rack->rc_rack_rtt;
2027 		}
2028 		if (cur != NULL) {
2029 			uint64_t off;
2030 
2031 			log.u_bbr.cur_del_rate = cur->deadline;
2032 			if ((mod == HYBRID_LOG_RATE_CAP) || (mod == HYBRID_LOG_CAP_CALC)) {
2033 				/* start = < lost | pkt_epoch > */
2034 				log.u_bbr.pkt_epoch = (uint32_t)(cur->start & 0x00000000ffffffff);
2035 				log.u_bbr.lost = (uint32_t)((cur->start >> 32) & 0x00000000ffffffff);
2036 				log.u_bbr.flex6 = cur->start_seq;
2037 				log.u_bbr.pkts_out = cur->end_seq;
2038 			} else {
2039 				/* start = < lost | pkt_epoch > */
2040 				log.u_bbr.pkt_epoch = (uint32_t)(cur->start & 0x00000000ffffffff);
2041 				log.u_bbr.lost = (uint32_t)((cur->start >> 32) & 0x00000000ffffffff);
2042 				/* end = < pkts_out | flex6 > */
2043 				log.u_bbr.flex6 = (uint32_t)(cur->end & 0x00000000ffffffff);
2044 				log.u_bbr.pkts_out = (uint32_t)((cur->end >> 32) & 0x00000000ffffffff);
2045 			}
2046 			/* first_send = <lt_epoch | epoch> */
2047 			log.u_bbr.epoch = (uint32_t)(cur->first_send & 0x00000000ffffffff);
2048 			log.u_bbr.lt_epoch = (uint32_t)((cur->first_send >> 32) & 0x00000000ffffffff);
2049 			/* localtime = <delivered | applimited>*/
2050 			log.u_bbr.applimited = (uint32_t)(cur->localtime & 0x00000000ffffffff);
2051 			log.u_bbr.delivered = (uint32_t)((cur->localtime >> 32) & 0x00000000ffffffff);
2052 			off = (uint64_t)(cur) - (uint64_t)(&rack->rc_tp->t_http_info[0]);
2053 			log.u_bbr.bbr_substate = (uint8_t)(off / sizeof(struct http_sendfile_track));
2054 			log.u_bbr.flex4 = (uint32_t)(rack->rc_tp->t_sndbytes - cur->sent_at_fs);
2055 			log.u_bbr.flex5 = (uint32_t)(rack->rc_tp->t_snd_rxt_bytes - cur->rxt_at_fs);
2056 			log.u_bbr.flex7 = (uint16_t)cur->hybrid_flags;
2057 		} else {
2058 			log.u_bbr.flex7 = 0xffff;
2059 			log.u_bbr.cur_del_rate = 0xffffffffffffffff;
2060 		}
2061 		/*
2062 		 * Compose bbr_state to be a bit wise 0000ADHF
2063 		 * where A is the always_pace flag
2064 		 * where D is the dgp_on flag
2065 		 * where H is the hybrid_mode on flag
2066 		 * where F is the use_fixed_rate flag.
2067 		 */
2068 		log.u_bbr.bbr_state = rack->rc_always_pace;
2069 		log.u_bbr.bbr_state <<= 1;
2070 		log.u_bbr.bbr_state |= rack->dgp_on;
2071 		log.u_bbr.bbr_state <<= 1;
2072 		log.u_bbr.bbr_state |= rack->rc_hybrid_mode;
2073 		log.u_bbr.bbr_state <<= 1;
2074 		log.u_bbr.bbr_state |= rack->use_fixed_rate;
2075 		log.u_bbr.flex8 = mod;
2076 		tcp_log_event(rack->rc_tp, NULL,
2077 		    &rack->rc_inp->inp_socket->so_rcv,
2078 		    &rack->rc_inp->inp_socket->so_snd,
2079 		    TCP_HYBRID_PACING_LOG, 0,
2080 		    0, &log, false, NULL, __func__, __LINE__, &tv);
2081 
2082 	}
2083 #endif
2084 }
2085 
2086 static inline uint64_t
2087 rack_compensate_for_linerate(struct tcp_rack *rack, uint64_t bw)
2088 {
2089 	uint64_t ret_bw, ether;
2090 	uint64_t u_segsiz;
2091 
2092 	ether = rack->rc_tp->t_maxseg + sizeof(struct tcphdr);
2093 	if (rack->r_is_v6){
2094 #ifdef INET6
2095 		ether += sizeof(struct ip6_hdr);
2096 #endif
2097 		ether += 14;	/* eheader size 6+6+2 */
2098 	} else {
2099 #ifdef INET
2100 		ether += sizeof(struct ip);
2101 #endif
2102 		ether += 14;	/* eheader size 6+6+2 */
2103 	}
2104 	u_segsiz = (uint64_t)min(ctf_fixed_maxseg(rack->rc_tp), rack->r_ctl.rc_pace_min_segs);
2105 	ret_bw = bw;
2106 	ret_bw *= ether;
2107 	ret_bw /= u_segsiz;
2108 	return (ret_bw);
2109 }
2110 
2111 static void
2112 rack_rate_cap_bw(struct tcp_rack *rack, uint64_t *bw, int *capped)
2113 {
2114 #ifdef TCP_REQUEST_TRK
2115 	struct timeval tv;
2116 	uint64_t timenow, timeleft, lenleft, lengone, calcbw;
2117 #endif
2118 
2119 	if (rack->r_ctl.bw_rate_cap == 0)
2120 		return;
2121 #ifdef TCP_REQUEST_TRK
2122 	if (rack->rc_catch_up && rack->rc_hybrid_mode &&
2123 	    (rack->r_ctl.rc_last_sft != NULL)) {
2124 		/*
2125 		 * We have a dynamic cap. The original target
2126 		 * is in bw_rate_cap, but we need to look at
2127 		 * how long it is until we hit the deadline.
2128 		 */
2129 		struct http_sendfile_track *ent;
2130 
2131 		ent = rack->r_ctl.rc_last_sft;
2132 		microuptime(&tv);
2133 		timenow = tcp_tv_to_lusectick(&tv);
2134 		if (timenow >= ent->deadline) {
2135 			/* No time left we do DGP only */
2136 			rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2137 					   0, 0, 0, HYBRID_LOG_OUTOFTIME, 0, ent);
2138 			rack->r_ctl.bw_rate_cap = 0;
2139 			return;
2140 		}
2141 		/* We have the time */
2142 		timeleft = rack->r_ctl.rc_last_sft->deadline - timenow;
2143 		if (timeleft < HPTS_MSEC_IN_SEC) {
2144 			/* If there is less than a ms left just use DGPs rate */
2145 			rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2146 					   0, timeleft, 0, HYBRID_LOG_OUTOFTIME, 0, ent);
2147 			rack->r_ctl.bw_rate_cap = 0;
2148 			return;
2149 		}
2150 		/*
2151 		 * Now lets find the amount of data left to send.
2152 		 *
2153 		 * Now ideally we want to use the end_seq to figure out how much more
2154 		 * but it might not be possible (only if we have the TRACK_FG_COMP on the entry..
2155 		 */
2156 		if (ent->flags & TCP_HTTP_TRACK_FLG_COMP) {
2157 			if (SEQ_GT(ent->end_seq, rack->rc_tp->snd_una))
2158 				lenleft = ent->end_seq - rack->rc_tp->snd_una;
2159 			else {
2160 				/* TSNH, we should catch it at the send */
2161 				rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2162 						   0, timeleft, 0, HYBRID_LOG_CAPERROR, 0, ent);
2163 				rack->r_ctl.bw_rate_cap = 0;
2164 				return;
2165 			}
2166 		} else {
2167 			/*
2168 			 * The hard way, figure out how much is gone and then
2169 			 * take that away from the total the client asked for
2170 			 * (thats off by tls overhead if this is tls).
2171 			 */
2172 			if (SEQ_GT(rack->rc_tp->snd_una, ent->start_seq))
2173 				lengone = rack->rc_tp->snd_una - ent->start_seq;
2174 			else
2175 				lengone = 0;
2176 			if (lengone < (ent->end - ent->start))
2177 				lenleft = (ent->end - ent->start) - lengone;
2178 			else {
2179 				/* TSNH, we should catch it at the send */
2180 				rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2181 						   0, timeleft, lengone, HYBRID_LOG_CAPERROR, 0, ent);
2182 				rack->r_ctl.bw_rate_cap = 0;
2183 				return;
2184 			}
2185 		}
2186 		if (lenleft == 0) {
2187 			/* We have it all sent */
2188 			rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2189 					   0, timeleft, lenleft, HYBRID_LOG_ALLSENT, 0, ent);
2190 			if (rack->r_ctl.bw_rate_cap)
2191 				goto normal_ratecap;
2192 			else
2193 				return;
2194 		}
2195 		calcbw = lenleft * HPTS_USEC_IN_SEC;
2196 		calcbw /= timeleft;
2197 		/* Now we must compensate for IP/TCP overhead */
2198 		calcbw = rack_compensate_for_linerate(rack, calcbw);
2199 		/* Update the bit rate cap */
2200 		rack->r_ctl.bw_rate_cap = calcbw;
2201 		if ((rack->r_ctl.rc_last_sft->hybrid_flags & TCP_HYBRID_PACING_S_MSS) &&
2202 		    (rack_hybrid_allow_set_maxseg == 1) &&
2203 		    ((rack->r_ctl.rc_last_sft->hybrid_flags & TCP_HYBRID_PACING_SETMSS) == 0)) {
2204 			/* Lets set in a smaller mss possibly here to match our rate-cap */
2205 			uint32_t orig_max;
2206 
2207 			orig_max = rack->r_ctl.rc_pace_max_segs;
2208 			rack->r_ctl.rc_last_sft->hybrid_flags |= TCP_HYBRID_PACING_SETMSS;
2209 			rack->r_ctl.rc_pace_max_segs = rack_get_pacing_len(rack, calcbw, ctf_fixed_maxseg(rack->rc_tp));
2210 			rack_log_type_pacing_sizes(rack->rc_tp, rack, rack->r_ctl.client_suggested_maxseg, orig_max, __LINE__, 5);
2211 		}
2212 		rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2213 				   calcbw, timeleft, lenleft, HYBRID_LOG_CAP_CALC, 0, ent);
2214 		if ((calcbw > 0) && (*bw > calcbw)) {
2215 			rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2216 					   *bw, ent->deadline, lenleft, HYBRID_LOG_RATE_CAP, 0, ent);
2217 			*capped = 1;
2218 			*bw = calcbw;
2219 		}
2220 		return;
2221 	}
2222 normal_ratecap:
2223 #endif
2224 	if ((rack->r_ctl.bw_rate_cap > 0) && (*bw > rack->r_ctl.bw_rate_cap)) {
2225 #ifdef TCP_REQUEST_TRK
2226 		if (rack->rc_hybrid_mode &&
2227 		    rack->rc_catch_up &&
2228 		    (rack->r_ctl.rc_last_sft->hybrid_flags & TCP_HYBRID_PACING_S_MSS) &&
2229 		    (rack_hybrid_allow_set_maxseg == 1) &&
2230 		    ((rack->r_ctl.rc_last_sft->hybrid_flags & TCP_HYBRID_PACING_SETMSS) == 0)) {
2231 			/* Lets set in a smaller mss possibly here to match our rate-cap */
2232 			uint32_t orig_max;
2233 
2234 			orig_max = rack->r_ctl.rc_pace_max_segs;
2235 			rack->r_ctl.rc_last_sft->hybrid_flags |= TCP_HYBRID_PACING_SETMSS;
2236 			rack->r_ctl.rc_pace_max_segs = rack_get_pacing_len(rack, rack->r_ctl.bw_rate_cap, ctf_fixed_maxseg(rack->rc_tp));
2237 			rack_log_type_pacing_sizes(rack->rc_tp, rack, rack->r_ctl.client_suggested_maxseg, orig_max, __LINE__, 5);
2238 		}
2239 #endif
2240 		*capped = 1;
2241 		*bw = rack->r_ctl.bw_rate_cap;
2242 		rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
2243 				   *bw, 0, 0,
2244 				   HYBRID_LOG_RATE_CAP, 1, NULL);
2245 	}
2246 }
2247 
2248 static uint64_t
2249 rack_get_gp_est(struct tcp_rack *rack)
2250 {
2251 	uint64_t bw, lt_bw, ret_bw;
2252 
2253 	if (rack->rc_gp_filled == 0) {
2254 		/*
2255 		 * We have yet no b/w measurement,
2256 		 * if we have a user set initial bw
2257 		 * return it. If we don't have that and
2258 		 * we have an srtt, use the tcp IW (10) to
2259 		 * calculate a fictional b/w over the SRTT
2260 		 * which is more or less a guess. Note
2261 		 * we don't use our IW from rack on purpose
2262 		 * so if we have like IW=30, we are not
2263 		 * calculating a "huge" b/w.
2264 		 */
2265 		uint64_t srtt;
2266 
2267 		lt_bw = rack_get_lt_bw(rack);
2268 		if (lt_bw) {
2269 			/*
2270 			 * No goodput bw but a long-term b/w does exist
2271 			 * lets use that.
2272 			 */
2273 			ret_bw = lt_bw;
2274 			goto compensate;
2275 		}
2276 		if (rack->r_ctl.init_rate)
2277 			return (rack->r_ctl.init_rate);
2278 
2279 		/* Ok lets come up with the IW guess, if we have a srtt */
2280 		if (rack->rc_tp->t_srtt == 0) {
2281 			/*
2282 			 * Go with old pacing method
2283 			 * i.e. burst mitigation only.
2284 			 */
2285 			return (0);
2286 		}
2287 		/* Ok lets get the initial TCP win (not racks) */
2288 		bw = tcp_compute_initwnd(tcp_maxseg(rack->rc_tp));
2289 		srtt = (uint64_t)rack->rc_tp->t_srtt;
2290 		bw *= (uint64_t)USECS_IN_SECOND;
2291 		bw /= srtt;
2292 		ret_bw = bw;
2293 		goto compensate;
2294 
2295 	}
2296 	if (rack->r_ctl.num_measurements >= RACK_REQ_AVG) {
2297 		/* Averaging is done, we can return the value */
2298 		bw = rack->r_ctl.gp_bw;
2299 	} else {
2300 		/* Still doing initial average must calculate */
2301 		bw = rack->r_ctl.gp_bw / max(rack->r_ctl.num_measurements, 1);
2302 	}
2303 	lt_bw = rack_get_lt_bw(rack);
2304 	if (lt_bw == 0) {
2305 		/* If we don't have one then equate it to the gp_bw */
2306 		lt_bw = rack->r_ctl.gp_bw;
2307 	}
2308 	if ((rack->r_cwnd_was_clamped == 1) && (rack->r_clamped_gets_lower > 0)){
2309 		/*  if clamped take the lowest */
2310 		if (lt_bw < bw)
2311 			ret_bw = lt_bw;
2312 		else
2313 			ret_bw = bw;
2314 	} else {
2315 		/* If not set for clamped to get lowest, take the highest */
2316 		if (lt_bw > bw)
2317 			ret_bw = lt_bw;
2318 		else
2319 			ret_bw = bw;
2320 	}
2321 	/*
2322 	 * Now lets compensate based on the TCP/IP overhead. Our
2323 	 * Goodput estimate does not include this so we must pace out
2324 	 * a bit faster since our pacing calculations do. The pacing
2325 	 * calculations use the base ETHERNET_SEGMENT_SIZE and the segsiz
2326 	 * we are using to do this, so we do that here in the opposite
2327 	 * direction as well. This means that if we are tunneled and the
2328 	 * segsiz is say 1200 bytes we will get quite a boost, but its
2329 	 * compensated for in the pacing time the opposite way.
2330 	 */
2331 compensate:
2332 	ret_bw = rack_compensate_for_linerate(rack, ret_bw);
2333 	return(ret_bw);
2334 }
2335 
2336 
2337 static uint64_t
2338 rack_get_bw(struct tcp_rack *rack)
2339 {
2340 	uint64_t bw;
2341 
2342 	if (rack->use_fixed_rate) {
2343 		/* Return the fixed pacing rate */
2344 		return (rack_get_fixed_pacing_bw(rack));
2345 	}
2346 	bw = rack_get_gp_est(rack);
2347 	return (bw);
2348 }
2349 
2350 static uint16_t
2351 rack_get_output_gain(struct tcp_rack *rack, struct rack_sendmap *rsm)
2352 {
2353 	if (rack->use_fixed_rate) {
2354 		return (100);
2355 	} else if (rack->in_probe_rtt && (rsm == NULL))
2356 		return (rack->r_ctl.rack_per_of_gp_probertt);
2357 	else if ((IN_FASTRECOVERY(rack->rc_tp->t_flags) &&
2358 		  rack->r_ctl.rack_per_of_gp_rec)) {
2359 		if (rsm) {
2360 			/* a retransmission always use the recovery rate */
2361 			return (rack->r_ctl.rack_per_of_gp_rec);
2362 		} else if (rack->rack_rec_nonrxt_use_cr) {
2363 			/* Directed to use the configured rate */
2364 			goto configured_rate;
2365 		} else if (rack->rack_no_prr &&
2366 			   (rack->r_ctl.rack_per_of_gp_rec > 100)) {
2367 			/* No PRR, lets just use the b/w estimate only */
2368 			return (100);
2369 		} else {
2370 			/*
2371 			 * Here we may have a non-retransmit but we
2372 			 * have no overrides, so just use the recovery
2373 			 * rate (prr is in effect).
2374 			 */
2375 			return (rack->r_ctl.rack_per_of_gp_rec);
2376 		}
2377 	}
2378 configured_rate:
2379 	/* For the configured rate we look at our cwnd vs the ssthresh */
2380 	if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
2381 		return (rack->r_ctl.rack_per_of_gp_ss);
2382 	else
2383 		return (rack->r_ctl.rack_per_of_gp_ca);
2384 }
2385 
2386 static void
2387 rack_log_dsack_event(struct tcp_rack *rack, uint8_t mod, uint32_t flex4, uint32_t flex5, uint32_t flex6)
2388 {
2389 	/*
2390 	 * Types of logs (mod value)
2391 	 * 1 = dsack_persists reduced by 1 via T-O or fast recovery exit.
2392 	 * 2 = a dsack round begins, persist is reset to 16.
2393 	 * 3 = a dsack round ends
2394 	 * 4 = Dsack option increases rack rtt flex5 is the srtt input, flex6 is thresh
2395 	 * 5 = Socket option set changing the control flags rc_rack_tmr_std_based, rc_rack_use_dsack
2396 	 * 6 = Final rack rtt, flex4 is srtt and flex6 is final limited thresh.
2397 	 */
2398 	if (tcp_bblogging_on(rack->rc_tp)) {
2399 		union tcp_log_stackspecific log;
2400 		struct timeval tv;
2401 
2402 		memset(&log, 0, sizeof(log));
2403 		log.u_bbr.flex1 = rack->rc_rack_tmr_std_based;
2404 		log.u_bbr.flex1 <<= 1;
2405 		log.u_bbr.flex1 |= rack->rc_rack_use_dsack;
2406 		log.u_bbr.flex1 <<= 1;
2407 		log.u_bbr.flex1 |= rack->rc_dsack_round_seen;
2408 		log.u_bbr.flex2 = rack->r_ctl.dsack_round_end;
2409 		log.u_bbr.flex3 = rack->r_ctl.num_dsack;
2410 		log.u_bbr.flex4 = flex4;
2411 		log.u_bbr.flex5 = flex5;
2412 		log.u_bbr.flex6 = flex6;
2413 		log.u_bbr.flex7 = rack->r_ctl.dsack_persist;
2414 		log.u_bbr.flex8 = mod;
2415 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2416 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2417 		    &rack->rc_inp->inp_socket->so_rcv,
2418 		    &rack->rc_inp->inp_socket->so_snd,
2419 		    RACK_DSACK_HANDLING, 0,
2420 		    0, &log, false, &tv);
2421 	}
2422 }
2423 
2424 static void
2425 rack_log_hdwr_pacing(struct tcp_rack *rack,
2426 		     uint64_t rate, uint64_t hw_rate, int line,
2427 		     int error, uint16_t mod)
2428 {
2429 	if (tcp_bblogging_on(rack->rc_tp)) {
2430 		union tcp_log_stackspecific log;
2431 		struct timeval tv;
2432 		const struct ifnet *ifp;
2433 
2434 		memset(&log, 0, sizeof(log));
2435 		log.u_bbr.flex1 = ((hw_rate >> 32) & 0x00000000ffffffff);
2436 		log.u_bbr.flex2 = (hw_rate & 0x00000000ffffffff);
2437 		if (rack->r_ctl.crte) {
2438 			ifp = rack->r_ctl.crte->ptbl->rs_ifp;
2439 		} else if (rack->rc_inp->inp_route.ro_nh &&
2440 			   rack->rc_inp->inp_route.ro_nh->nh_ifp) {
2441 			ifp = rack->rc_inp->inp_route.ro_nh->nh_ifp;
2442 		} else
2443 			ifp = NULL;
2444 		if (ifp) {
2445 			log.u_bbr.flex3 = (((uint64_t)ifp  >> 32) & 0x00000000ffffffff);
2446 			log.u_bbr.flex4 = ((uint64_t)ifp & 0x00000000ffffffff);
2447 		}
2448 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2449 		log.u_bbr.bw_inuse = rate;
2450 		log.u_bbr.flex5 = line;
2451 		log.u_bbr.flex6 = error;
2452 		log.u_bbr.flex7 = mod;
2453 		log.u_bbr.applimited = rack->r_ctl.rc_pace_max_segs;
2454 		log.u_bbr.flex8 = rack->use_fixed_rate;
2455 		log.u_bbr.flex8 <<= 1;
2456 		log.u_bbr.flex8 |= rack->rack_hdrw_pacing;
2457 		log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
2458 		log.u_bbr.delRate = rack->r_ctl.crte_prev_rate;
2459 		if (rack->r_ctl.crte)
2460 			log.u_bbr.cur_del_rate = rack->r_ctl.crte->rate;
2461 		else
2462 			log.u_bbr.cur_del_rate = 0;
2463 		log.u_bbr.rttProp = rack->r_ctl.last_hw_bw_req;
2464 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2465 		    &rack->rc_inp->inp_socket->so_rcv,
2466 		    &rack->rc_inp->inp_socket->so_snd,
2467 		    BBR_LOG_HDWR_PACE, 0,
2468 		    0, &log, false, &tv);
2469 	}
2470 }
2471 
2472 static uint64_t
2473 rack_get_output_bw(struct tcp_rack *rack, uint64_t bw, struct rack_sendmap *rsm, int *capped)
2474 {
2475 	/*
2476 	 * We allow rack_per_of_gp_xx to dictate our bw rate we want.
2477 	 */
2478 	uint64_t bw_est, high_rate;
2479 	uint64_t gain;
2480 
2481 	if ((rack->r_pacing_discount == 0) ||
2482 	    (rack_full_buffer_discount == 0)) {
2483 		/*
2484 		 * No buffer level based discount from client buffer
2485 		 * level is enabled or the feature is disabled.
2486 		 */
2487 		gain = (uint64_t)rack_get_output_gain(rack, rsm);
2488 		bw_est = bw * gain;
2489 		bw_est /= (uint64_t)100;
2490 	} else {
2491 		/*
2492 		 * We have a discount in place apply it with
2493 		 * just a 100% gain (we get no boost if the buffer
2494 		 * is full).
2495 		 */
2496 		uint64_t discount;
2497 
2498 		discount = bw * (uint64_t)(rack_full_buffer_discount * rack->r_ctl.pacing_discount_amm);
2499 		discount /= 100;
2500 		/* What %% of the b/w do we discount */
2501 		bw_est = bw - discount;
2502 	}
2503 	/* Never fall below the minimum (def 64kbps) */
2504 	if (bw_est < RACK_MIN_BW)
2505 		bw_est = RACK_MIN_BW;
2506 	if (rack->r_rack_hw_rate_caps) {
2507 		/* Rate caps are in place */
2508 		if (rack->r_ctl.crte != NULL) {
2509 			/* We have a hdwr rate already */
2510 			high_rate = tcp_hw_highest_rate(rack->r_ctl.crte);
2511 			if (bw_est >= high_rate) {
2512 				/* We are capping bw at the highest rate table entry */
2513 				if (rack_hw_rate_cap_per &&
2514 				    (((high_rate * (100 + rack_hw_rate_cap_per)) / 100) < bw_est)) {
2515 					rack->r_rack_hw_rate_caps = 0;
2516 					goto done;
2517 				}
2518 				rack_log_hdwr_pacing(rack,
2519 						     bw_est, high_rate, __LINE__,
2520 						     0, 3);
2521 				bw_est = high_rate;
2522 				if (capped)
2523 					*capped = 1;
2524 			}
2525 		} else if ((rack->rack_hdrw_pacing == 0) &&
2526 			   (rack->rack_hdw_pace_ena) &&
2527 			   (rack->rack_attempt_hdwr_pace == 0) &&
2528 			   (rack->rc_inp->inp_route.ro_nh != NULL) &&
2529 			   (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
2530 			/*
2531 			 * Special case, we have not yet attempted hardware
2532 			 * pacing, and yet we may, when we do, find out if we are
2533 			 * above the highest rate. We need to know the maxbw for the interface
2534 			 * in question (if it supports ratelimiting). We get back
2535 			 * a 0, if the interface is not found in the RL lists.
2536 			 */
2537 			high_rate = tcp_hw_highest_rate_ifp(rack->rc_inp->inp_route.ro_nh->nh_ifp, rack->rc_inp);
2538 			if (high_rate) {
2539 				/* Yep, we have a rate is it above this rate? */
2540 				if (bw_est > high_rate) {
2541 					bw_est = high_rate;
2542 					if (capped)
2543 						*capped = 1;
2544 				}
2545 			}
2546 		}
2547 	}
2548 done:
2549 	return (bw_est);
2550 }
2551 
2552 static void
2553 rack_log_retran_reason(struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t tsused, uint32_t thresh, int mod)
2554 {
2555 	if (tcp_bblogging_on(rack->rc_tp)) {
2556 		union tcp_log_stackspecific log;
2557 		struct timeval tv;
2558 
2559 		if (rack->sack_attack_disable > 0)
2560 			goto log_anyway;
2561 		if ((mod != 1) && (rack_verbose_logging == 0))  {
2562 			/*
2563 			 * We get 3 values currently for mod
2564 			 * 1 - We are retransmitting and this tells the reason.
2565 			 * 2 - We are clearing a dup-ack count.
2566 			 * 3 - We are incrementing a dup-ack count.
2567 			 *
2568 			 * The clear/increment are only logged
2569 			 * if you have BBverbose on.
2570 			 */
2571 			return;
2572 		}
2573 log_anyway:
2574 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2575 		log.u_bbr.flex1 = tsused;
2576 		log.u_bbr.flex2 = thresh;
2577 		log.u_bbr.flex3 = rsm->r_flags;
2578 		log.u_bbr.flex4 = rsm->r_dupack;
2579 		log.u_bbr.flex5 = rsm->r_start;
2580 		log.u_bbr.flex6 = rsm->r_end;
2581 		log.u_bbr.flex8 = mod;
2582 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2583 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2584 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2585 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2586 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2587 		log.u_bbr.pacing_gain = rack->r_must_retran;
2588 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2589 		    &rack->rc_inp->inp_socket->so_rcv,
2590 		    &rack->rc_inp->inp_socket->so_snd,
2591 		    BBR_LOG_SETTINGS_CHG, 0,
2592 		    0, &log, false, &tv);
2593 	}
2594 }
2595 
2596 static void
2597 rack_log_to_start(struct tcp_rack *rack, uint32_t cts, uint32_t to, int32_t slot, uint8_t which)
2598 {
2599 	if (tcp_bblogging_on(rack->rc_tp)) {
2600 		union tcp_log_stackspecific log;
2601 		struct timeval tv;
2602 
2603 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2604 		log.u_bbr.flex1 = rack->rc_tp->t_srtt;
2605 		log.u_bbr.flex2 = to;
2606 		log.u_bbr.flex3 = rack->r_ctl.rc_hpts_flags;
2607 		log.u_bbr.flex4 = slot;
2608 		log.u_bbr.flex5 = rack->rc_tp->t_hpts_slot;
2609 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2610 		log.u_bbr.flex7 = rack->rc_in_persist;
2611 		log.u_bbr.flex8 = which;
2612 		if (rack->rack_no_prr)
2613 			log.u_bbr.pkts_out = 0;
2614 		else
2615 			log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
2616 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2617 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2618 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2619 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2620 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2621 		log.u_bbr.pacing_gain = rack->r_must_retran;
2622 		log.u_bbr.cwnd_gain = rack->rack_deferred_inited;
2623 		log.u_bbr.pkt_epoch = rack->rc_has_collapsed;
2624 		log.u_bbr.lt_epoch = rack->rc_tp->t_rxtshift;
2625 		log.u_bbr.lost = rack_rto_min;
2626 		log.u_bbr.epoch = rack->r_ctl.roundends;
2627 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2628 		    &rack->rc_inp->inp_socket->so_rcv,
2629 		    &rack->rc_inp->inp_socket->so_snd,
2630 		    BBR_LOG_TIMERSTAR, 0,
2631 		    0, &log, false, &tv);
2632 	}
2633 }
2634 
2635 static void
2636 rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm)
2637 {
2638 	if (tcp_bblogging_on(rack->rc_tp)) {
2639 		union tcp_log_stackspecific log;
2640 		struct timeval tv;
2641 
2642 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2643 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2644 		log.u_bbr.flex8 = to_num;
2645 		log.u_bbr.flex1 = rack->r_ctl.rc_rack_min_rtt;
2646 		log.u_bbr.flex2 = rack->rc_rack_rtt;
2647 		if (rsm == NULL)
2648 			log.u_bbr.flex3 = 0;
2649 		else
2650 			log.u_bbr.flex3 = rsm->r_end - rsm->r_start;
2651 		if (rack->rack_no_prr)
2652 			log.u_bbr.flex5 = 0;
2653 		else
2654 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2655 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2656 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2657 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2658 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2659 		log.u_bbr.pacing_gain = rack->r_must_retran;
2660 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2661 		    &rack->rc_inp->inp_socket->so_rcv,
2662 		    &rack->rc_inp->inp_socket->so_snd,
2663 		    BBR_LOG_RTO, 0,
2664 		    0, &log, false, &tv);
2665 	}
2666 }
2667 
2668 static void
2669 rack_log_map_chg(struct tcpcb *tp, struct tcp_rack *rack,
2670 		 struct rack_sendmap *prev,
2671 		 struct rack_sendmap *rsm,
2672 		 struct rack_sendmap *next,
2673 		 int flag, uint32_t th_ack, int line)
2674 {
2675 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
2676 		union tcp_log_stackspecific log;
2677 		struct timeval tv;
2678 
2679 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2680 		log.u_bbr.flex8 = flag;
2681 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2682 		log.u_bbr.cur_del_rate = (uint64_t)prev;
2683 		log.u_bbr.delRate = (uint64_t)rsm;
2684 		log.u_bbr.rttProp = (uint64_t)next;
2685 		log.u_bbr.flex7 = 0;
2686 		if (prev) {
2687 			log.u_bbr.flex1 = prev->r_start;
2688 			log.u_bbr.flex2 = prev->r_end;
2689 			log.u_bbr.flex7 |= 0x4;
2690 		}
2691 		if (rsm) {
2692 			log.u_bbr.flex3 = rsm->r_start;
2693 			log.u_bbr.flex4 = rsm->r_end;
2694 			log.u_bbr.flex7 |= 0x2;
2695 		}
2696 		if (next) {
2697 			log.u_bbr.flex5 = next->r_start;
2698 			log.u_bbr.flex6 = next->r_end;
2699 			log.u_bbr.flex7 |= 0x1;
2700 		}
2701 		log.u_bbr.applimited = line;
2702 		log.u_bbr.pkts_out = th_ack;
2703 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2704 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2705 		if (rack->rack_no_prr)
2706 			log.u_bbr.lost = 0;
2707 		else
2708 			log.u_bbr.lost = rack->r_ctl.rc_prr_sndcnt;
2709 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2710 		    &rack->rc_inp->inp_socket->so_rcv,
2711 		    &rack->rc_inp->inp_socket->so_snd,
2712 		    TCP_LOG_MAPCHG, 0,
2713 		    0, &log, false, &tv);
2714 	}
2715 }
2716 
2717 static void
2718 rack_log_rtt_upd(struct tcpcb *tp, struct tcp_rack *rack, uint32_t t, uint32_t len,
2719 		 struct rack_sendmap *rsm, int conf)
2720 {
2721 	if (tcp_bblogging_on(tp)) {
2722 		union tcp_log_stackspecific log;
2723 		struct timeval tv;
2724 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2725 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2726 		log.u_bbr.flex1 = t;
2727 		log.u_bbr.flex2 = len;
2728 		log.u_bbr.flex3 = rack->r_ctl.rc_rack_min_rtt;
2729 		log.u_bbr.flex4 = rack->r_ctl.rack_rs.rs_rtt_lowest;
2730 		log.u_bbr.flex5 = rack->r_ctl.rack_rs.rs_rtt_highest;
2731 		log.u_bbr.flex6 = rack->r_ctl.rack_rs.rs_us_rtrcnt;
2732 		log.u_bbr.flex7 = conf;
2733 		log.u_bbr.rttProp = (uint64_t)rack->r_ctl.rack_rs.rs_rtt_tot;
2734 		log.u_bbr.flex8 = rack->r_ctl.rc_rate_sample_method;
2735 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2736 		log.u_bbr.delivered = rack->r_ctl.rack_rs.rs_us_rtrcnt;
2737 		log.u_bbr.pkts_out = rack->r_ctl.rack_rs.rs_flags;
2738 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2739 		if (rsm) {
2740 			log.u_bbr.pkt_epoch = rsm->r_start;
2741 			log.u_bbr.lost = rsm->r_end;
2742 			log.u_bbr.cwnd_gain = rsm->r_rtr_cnt;
2743 			/* We loose any upper of the 24 bits */
2744 			log.u_bbr.pacing_gain = (uint16_t)rsm->r_flags;
2745 		} else {
2746 			/* Its a SYN */
2747 			log.u_bbr.pkt_epoch = rack->rc_tp->iss;
2748 			log.u_bbr.lost = 0;
2749 			log.u_bbr.cwnd_gain = 0;
2750 			log.u_bbr.pacing_gain = 0;
2751 		}
2752 		/* Write out general bits of interest rrs here */
2753 		log.u_bbr.use_lt_bw = rack->rc_highly_buffered;
2754 		log.u_bbr.use_lt_bw <<= 1;
2755 		log.u_bbr.use_lt_bw |= rack->forced_ack;
2756 		log.u_bbr.use_lt_bw <<= 1;
2757 		log.u_bbr.use_lt_bw |= rack->rc_gp_dyn_mul;
2758 		log.u_bbr.use_lt_bw <<= 1;
2759 		log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
2760 		log.u_bbr.use_lt_bw <<= 1;
2761 		log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
2762 		log.u_bbr.use_lt_bw <<= 1;
2763 		log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
2764 		log.u_bbr.use_lt_bw <<= 1;
2765 		log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
2766 		log.u_bbr.use_lt_bw <<= 1;
2767 		log.u_bbr.use_lt_bw |= rack->rc_dragged_bottom;
2768 		log.u_bbr.applimited = rack->r_ctl.rc_target_probertt_flight;
2769 		log.u_bbr.epoch = rack->r_ctl.rc_time_probertt_starts;
2770 		log.u_bbr.lt_epoch = rack->r_ctl.rc_time_probertt_entered;
2771 		log.u_bbr.cur_del_rate = rack->r_ctl.rc_lower_rtt_us_cts;
2772 		log.u_bbr.delRate = rack->r_ctl.rc_gp_srtt;
2773 		log.u_bbr.bw_inuse = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
2774 		log.u_bbr.bw_inuse <<= 32;
2775 		if (rsm)
2776 			log.u_bbr.bw_inuse |= ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]);
2777 		TCP_LOG_EVENTP(tp, NULL,
2778 		    &rack->rc_inp->inp_socket->so_rcv,
2779 		    &rack->rc_inp->inp_socket->so_snd,
2780 		    BBR_LOG_BBRRTT, 0,
2781 		    0, &log, false, &tv);
2782 
2783 
2784 	}
2785 }
2786 
2787 static void
2788 rack_log_rtt_sample(struct tcp_rack *rack, uint32_t rtt)
2789 {
2790 	/*
2791 	 * Log the rtt sample we are
2792 	 * applying to the srtt algorithm in
2793 	 * useconds.
2794 	 */
2795 	if (tcp_bblogging_on(rack->rc_tp)) {
2796 		union tcp_log_stackspecific log;
2797 		struct timeval tv;
2798 
2799 		/* Convert our ms to a microsecond */
2800 		memset(&log, 0, sizeof(log));
2801 		log.u_bbr.flex1 = rtt;
2802 		log.u_bbr.flex2 = rack->r_ctl.ack_count;
2803 		log.u_bbr.flex3 = rack->r_ctl.sack_count;
2804 		log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move;
2805 		log.u_bbr.flex5 = rack->r_ctl.sack_moved_extra;
2806 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2807 		log.u_bbr.flex7 = 1;
2808 		log.u_bbr.flex8 = rack->sack_attack_disable;
2809 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2810 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2811 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2812 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2813 		log.u_bbr.pacing_gain = rack->r_must_retran;
2814 		/*
2815 		 * We capture in delRate the upper 32 bits as
2816 		 * the confidence level we had declared, and the
2817 		 * lower 32 bits as the actual RTT using the arrival
2818 		 * timestamp.
2819 		 */
2820 		log.u_bbr.delRate = rack->r_ctl.rack_rs.confidence;
2821 		log.u_bbr.delRate <<= 32;
2822 		log.u_bbr.delRate |= rack->r_ctl.rack_rs.rs_us_rtt;
2823 		/* Lets capture all the things that make up t_rtxcur */
2824 		log.u_bbr.applimited = rack_rto_min;
2825 		log.u_bbr.epoch = rack_rto_max;
2826 		log.u_bbr.lt_epoch = rack->r_ctl.timer_slop;
2827 		log.u_bbr.lost = rack_rto_min;
2828 		log.u_bbr.pkt_epoch = TICKS_2_USEC(tcp_rexmit_slop);
2829 		log.u_bbr.rttProp = RACK_REXMTVAL(rack->rc_tp);
2830 		log.u_bbr.bw_inuse = rack->r_ctl.act_rcv_time.tv_sec;
2831 		log.u_bbr.bw_inuse *= HPTS_USEC_IN_SEC;
2832 		log.u_bbr.bw_inuse += rack->r_ctl.act_rcv_time.tv_usec;
2833 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2834 		    &rack->rc_inp->inp_socket->so_rcv,
2835 		    &rack->rc_inp->inp_socket->so_snd,
2836 		    TCP_LOG_RTT, 0,
2837 		    0, &log, false, &tv);
2838 	}
2839 }
2840 
2841 static void
2842 rack_log_rtt_sample_calc(struct tcp_rack *rack, uint32_t rtt, uint32_t send_time, uint32_t ack_time, int where)
2843 {
2844 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
2845 		union tcp_log_stackspecific log;
2846 		struct timeval tv;
2847 
2848 		/* Convert our ms to a microsecond */
2849 		memset(&log, 0, sizeof(log));
2850 		log.u_bbr.flex1 = rtt;
2851 		log.u_bbr.flex2 = send_time;
2852 		log.u_bbr.flex3 = ack_time;
2853 		log.u_bbr.flex4 = where;
2854 		log.u_bbr.flex7 = 2;
2855 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2856 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2857 		    &rack->rc_inp->inp_socket->so_rcv,
2858 		    &rack->rc_inp->inp_socket->so_snd,
2859 		    TCP_LOG_RTT, 0,
2860 		    0, &log, false, &tv);
2861 	}
2862 }
2863 
2864 
2865 static void
2866 rack_log_rtt_sendmap(struct tcp_rack *rack, uint32_t idx, uint64_t tsv, uint32_t tsecho)
2867 {
2868 	if (tcp_bblogging_on(rack->rc_tp)) {
2869 		union tcp_log_stackspecific log;
2870 		struct timeval tv;
2871 
2872 		/* Convert our ms to a microsecond */
2873 		memset(&log, 0, sizeof(log));
2874 		log.u_bbr.flex1 = idx;
2875 		log.u_bbr.flex2 = rack_ts_to_msec(tsv);
2876 		log.u_bbr.flex3 = tsecho;
2877 		log.u_bbr.flex7 = 3;
2878 		log.u_bbr.rttProp = tsv;
2879 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2880 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2881 		    &rack->rc_inp->inp_socket->so_rcv,
2882 		    &rack->rc_inp->inp_socket->so_snd,
2883 		    TCP_LOG_RTT, 0,
2884 		    0, &log, false, &tv);
2885 	}
2886 }
2887 
2888 
2889 static inline void
2890 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick,  int event, int line)
2891 {
2892 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
2893 		union tcp_log_stackspecific log;
2894 		struct timeval tv;
2895 
2896 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2897 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2898 		log.u_bbr.flex1 = line;
2899 		log.u_bbr.flex2 = tick;
2900 		log.u_bbr.flex3 = tp->t_maxunacktime;
2901 		log.u_bbr.flex4 = tp->t_acktime;
2902 		log.u_bbr.flex8 = event;
2903 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2904 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2905 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2906 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2907 		log.u_bbr.pacing_gain = rack->r_must_retran;
2908 		TCP_LOG_EVENTP(tp, NULL,
2909 		    &rack->rc_inp->inp_socket->so_rcv,
2910 		    &rack->rc_inp->inp_socket->so_snd,
2911 		    BBR_LOG_PROGRESS, 0,
2912 		    0, &log, false, &tv);
2913 	}
2914 }
2915 
2916 static void
2917 rack_log_type_bbrsnd(struct tcp_rack *rack, uint32_t len, uint32_t slot, uint32_t cts, struct timeval *tv, int line)
2918 {
2919 	if (tcp_bblogging_on(rack->rc_tp)) {
2920 		union tcp_log_stackspecific log;
2921 
2922 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2923 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2924 		log.u_bbr.flex1 = slot;
2925 		if (rack->rack_no_prr)
2926 			log.u_bbr.flex2 = 0;
2927 		else
2928 			log.u_bbr.flex2 = rack->r_ctl.rc_prr_sndcnt;
2929 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
2930 		log.u_bbr.flex5 = rack->r_ctl.ack_during_sd;
2931 		log.u_bbr.flex6 = line;
2932 		log.u_bbr.flex7 = (0x0000ffff & rack->r_ctl.rc_hpts_flags);
2933 		log.u_bbr.flex8 = rack->rc_in_persist;
2934 		log.u_bbr.timeStamp = cts;
2935 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2936 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2937 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2938 		log.u_bbr.pacing_gain = rack->r_must_retran;
2939 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2940 		    &rack->rc_inp->inp_socket->so_rcv,
2941 		    &rack->rc_inp->inp_socket->so_snd,
2942 		    BBR_LOG_BBRSND, 0,
2943 		    0, &log, false, tv);
2944 	}
2945 }
2946 
2947 static void
2948 rack_log_doseg_done(struct tcp_rack *rack, uint32_t cts, int32_t nxt_pkt, int32_t did_out, int way_out, int nsegs)
2949 {
2950 	if (tcp_bblogging_on(rack->rc_tp)) {
2951 		union tcp_log_stackspecific log;
2952 		struct timeval tv;
2953 
2954 		memset(&log, 0, sizeof(log));
2955 		log.u_bbr.flex1 = did_out;
2956 		log.u_bbr.flex2 = nxt_pkt;
2957 		log.u_bbr.flex3 = way_out;
2958 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
2959 		if (rack->rack_no_prr)
2960 			log.u_bbr.flex5 = 0;
2961 		else
2962 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2963 		log.u_bbr.flex6 = nsegs;
2964 		log.u_bbr.applimited = rack->r_ctl.rc_pace_min_segs;
2965 		log.u_bbr.flex7 = rack->rc_ack_can_sendout_data;	/* Do we have ack-can-send set */
2966 		log.u_bbr.flex7 <<= 1;
2967 		log.u_bbr.flex7 |= rack->r_fast_output;	/* is fast output primed */
2968 		log.u_bbr.flex7 <<= 1;
2969 		log.u_bbr.flex7 |= rack->r_wanted_output;	/* Do we want output */
2970 		log.u_bbr.flex8 = rack->rc_in_persist;
2971 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
2972 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2973 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2974 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
2975 		log.u_bbr.use_lt_bw <<= 1;
2976 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
2977 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2978 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2979 		log.u_bbr.pacing_gain = rack->r_must_retran;
2980 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2981 		    &rack->rc_inp->inp_socket->so_rcv,
2982 		    &rack->rc_inp->inp_socket->so_snd,
2983 		    BBR_LOG_DOSEG_DONE, 0,
2984 		    0, &log, false, &tv);
2985 	}
2986 }
2987 
2988 static void
2989 rack_log_type_pacing_sizes(struct tcpcb *tp, struct tcp_rack *rack, uint32_t arg1, uint32_t arg2, uint32_t arg3, uint8_t frm)
2990 {
2991 	if (tcp_bblogging_on(rack->rc_tp)) {
2992 		union tcp_log_stackspecific log;
2993 		struct timeval tv;
2994 
2995 		memset(&log, 0, sizeof(log));
2996 		log.u_bbr.flex1 = rack->r_ctl.rc_pace_min_segs;
2997 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
2998 		log.u_bbr.flex4 = arg1;
2999 		log.u_bbr.flex5 = arg2;
3000 		log.u_bbr.flex7 = rack->r_ctl.rc_user_set_min_segs;
3001 		log.u_bbr.flex6 = arg3;
3002 		log.u_bbr.flex8 = frm;
3003 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3004 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3005 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
3006 		log.u_bbr.applimited = rack->r_ctl.rc_sacked;
3007 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
3008 		log.u_bbr.pacing_gain = rack->r_must_retran;
3009 		TCP_LOG_EVENTP(tp, NULL, &tptosocket(tp)->so_rcv,
3010 		    &tptosocket(tp)->so_snd,
3011 		    TCP_HDWR_PACE_SIZE, 0, 0, &log, false, &tv);
3012 	}
3013 }
3014 
3015 static void
3016 rack_log_type_just_return(struct tcp_rack *rack, uint32_t cts, uint32_t tlen, uint32_t slot,
3017 			  uint8_t hpts_calling, int reason, uint32_t cwnd_to_use)
3018 {
3019 	if (tcp_bblogging_on(rack->rc_tp)) {
3020 		union tcp_log_stackspecific log;
3021 		struct timeval tv;
3022 
3023 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3024 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
3025 		log.u_bbr.flex1 = slot;
3026 		log.u_bbr.flex2 = rack->r_ctl.rc_hpts_flags;
3027 		log.u_bbr.flex4 = reason;
3028 		if (rack->rack_no_prr)
3029 			log.u_bbr.flex5 = 0;
3030 		else
3031 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
3032 		log.u_bbr.flex7 = hpts_calling;
3033 		log.u_bbr.flex8 = rack->rc_in_persist;
3034 		log.u_bbr.lt_epoch = cwnd_to_use;
3035 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3036 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3037 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
3038 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
3039 		log.u_bbr.pacing_gain = rack->r_must_retran;
3040 		log.u_bbr.cwnd_gain = rack->rc_has_collapsed;
3041 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3042 		    &rack->rc_inp->inp_socket->so_rcv,
3043 		    &rack->rc_inp->inp_socket->so_snd,
3044 		    BBR_LOG_JUSTRET, 0,
3045 		    tlen, &log, false, &tv);
3046 	}
3047 }
3048 
3049 static void
3050 rack_log_to_cancel(struct tcp_rack *rack, int32_t hpts_removed, int line, uint32_t us_cts,
3051 		   struct timeval *tv, uint32_t flags_on_entry)
3052 {
3053 	if (tcp_bblogging_on(rack->rc_tp)) {
3054 		union tcp_log_stackspecific log;
3055 
3056 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3057 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
3058 		log.u_bbr.flex1 = line;
3059 		log.u_bbr.flex2 = rack->r_ctl.rc_last_output_to;
3060 		log.u_bbr.flex3 = flags_on_entry;
3061 		log.u_bbr.flex4 = us_cts;
3062 		if (rack->rack_no_prr)
3063 			log.u_bbr.flex5 = 0;
3064 		else
3065 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
3066 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
3067 		log.u_bbr.flex7 = hpts_removed;
3068 		log.u_bbr.flex8 = 1;
3069 		log.u_bbr.applimited = rack->r_ctl.rc_hpts_flags;
3070 		log.u_bbr.timeStamp = us_cts;
3071 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3072 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
3073 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
3074 		log.u_bbr.pacing_gain = rack->r_must_retran;
3075 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3076 		    &rack->rc_inp->inp_socket->so_rcv,
3077 		    &rack->rc_inp->inp_socket->so_snd,
3078 		    BBR_LOG_TIMERCANC, 0,
3079 		    0, &log, false, tv);
3080 	}
3081 }
3082 
3083 static void
3084 rack_log_alt_to_to_cancel(struct tcp_rack *rack,
3085 			  uint32_t flex1, uint32_t flex2,
3086 			  uint32_t flex3, uint32_t flex4,
3087 			  uint32_t flex5, uint32_t flex6,
3088 			  uint16_t flex7, uint8_t mod)
3089 {
3090 	if (tcp_bblogging_on(rack->rc_tp)) {
3091 		union tcp_log_stackspecific log;
3092 		struct timeval tv;
3093 
3094 		if (mod == 1) {
3095 			/* No you can't use 1, its for the real to cancel */
3096 			return;
3097 		}
3098 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3099 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3100 		log.u_bbr.flex1 = flex1;
3101 		log.u_bbr.flex2 = flex2;
3102 		log.u_bbr.flex3 = flex3;
3103 		log.u_bbr.flex4 = flex4;
3104 		log.u_bbr.flex5 = flex5;
3105 		log.u_bbr.flex6 = flex6;
3106 		log.u_bbr.flex7 = flex7;
3107 		log.u_bbr.flex8 = mod;
3108 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3109 		    &rack->rc_inp->inp_socket->so_rcv,
3110 		    &rack->rc_inp->inp_socket->so_snd,
3111 		    BBR_LOG_TIMERCANC, 0,
3112 		    0, &log, false, &tv);
3113 	}
3114 }
3115 
3116 static void
3117 rack_log_to_processing(struct tcp_rack *rack, uint32_t cts, int32_t ret, int32_t timers)
3118 {
3119 	if (tcp_bblogging_on(rack->rc_tp)) {
3120 		union tcp_log_stackspecific log;
3121 		struct timeval tv;
3122 
3123 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3124 		log.u_bbr.flex1 = timers;
3125 		log.u_bbr.flex2 = ret;
3126 		log.u_bbr.flex3 = rack->r_ctl.rc_timer_exp;
3127 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
3128 		log.u_bbr.flex5 = cts;
3129 		if (rack->rack_no_prr)
3130 			log.u_bbr.flex6 = 0;
3131 		else
3132 			log.u_bbr.flex6 = rack->r_ctl.rc_prr_sndcnt;
3133 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
3134 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
3135 		log.u_bbr.pacing_gain = rack->r_must_retran;
3136 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3137 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3138 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3139 		    &rack->rc_inp->inp_socket->so_rcv,
3140 		    &rack->rc_inp->inp_socket->so_snd,
3141 		    BBR_LOG_TO_PROCESS, 0,
3142 		    0, &log, false, &tv);
3143 	}
3144 }
3145 
3146 static void
3147 rack_log_to_prr(struct tcp_rack *rack, int frm, int orig_cwnd, int line)
3148 {
3149 	if (tcp_bblogging_on(rack->rc_tp)) {
3150 		union tcp_log_stackspecific log;
3151 		struct timeval tv;
3152 
3153 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3154 		log.u_bbr.flex1 = rack->r_ctl.rc_prr_out;
3155 		log.u_bbr.flex2 = rack->r_ctl.rc_prr_recovery_fs;
3156 		if (rack->rack_no_prr)
3157 			log.u_bbr.flex3 = 0;
3158 		else
3159 			log.u_bbr.flex3 = rack->r_ctl.rc_prr_sndcnt;
3160 		log.u_bbr.flex4 = rack->r_ctl.rc_prr_delivered;
3161 		log.u_bbr.flex5 = rack->r_ctl.rc_sacked;
3162 		log.u_bbr.flex6 = rack->r_ctl.rc_holes_rxt;
3163 		log.u_bbr.flex7 = line;
3164 		log.u_bbr.flex8 = frm;
3165 		log.u_bbr.pkts_out = orig_cwnd;
3166 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3167 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3168 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
3169 		log.u_bbr.use_lt_bw <<= 1;
3170 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
3171 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3172 		    &rack->rc_inp->inp_socket->so_rcv,
3173 		    &rack->rc_inp->inp_socket->so_snd,
3174 		    BBR_LOG_BBRUPD, 0,
3175 		    0, &log, false, &tv);
3176 	}
3177 }
3178 
3179 #ifdef TCP_SAD_DETECTION
3180 static void
3181 rack_log_sad(struct tcp_rack *rack, int event)
3182 {
3183 	if (tcp_bblogging_on(rack->rc_tp)) {
3184 		union tcp_log_stackspecific log;
3185 		struct timeval tv;
3186 
3187 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3188 		log.u_bbr.flex1 = rack->r_ctl.sack_count;
3189 		log.u_bbr.flex2 = rack->r_ctl.ack_count;
3190 		log.u_bbr.flex3 = rack->r_ctl.sack_moved_extra;
3191 		log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move;
3192 		log.u_bbr.flex5 = rack->r_ctl.rc_num_maps_alloced;
3193 		log.u_bbr.flex6 = tcp_sack_to_ack_thresh;
3194 		log.u_bbr.pkts_out = tcp_sack_to_move_thresh;
3195 		log.u_bbr.lt_epoch = (tcp_force_detection << 8);
3196 		log.u_bbr.lt_epoch |= rack->do_detection;
3197 		log.u_bbr.applimited = tcp_map_minimum;
3198 		log.u_bbr.flex7 = rack->sack_attack_disable;
3199 		log.u_bbr.flex8 = event;
3200 		log.u_bbr.bbr_state = rack->rc_suspicious;
3201 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3202 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3203 		log.u_bbr.delivered = tcp_sad_decay_val;
3204 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3205 		    &rack->rc_inp->inp_socket->so_rcv,
3206 		    &rack->rc_inp->inp_socket->so_snd,
3207 		    TCP_SAD_DETECT, 0,
3208 		    0, &log, false, &tv);
3209 	}
3210 }
3211 #endif
3212 
3213 static void
3214 rack_counter_destroy(void)
3215 {
3216 	counter_u64_free(rack_total_bytes);
3217 	counter_u64_free(rack_fto_send);
3218 	counter_u64_free(rack_fto_rsm_send);
3219 	counter_u64_free(rack_nfto_resend);
3220 	counter_u64_free(rack_hw_pace_init_fail);
3221 	counter_u64_free(rack_hw_pace_lost);
3222 	counter_u64_free(rack_non_fto_send);
3223 	counter_u64_free(rack_extended_rfo);
3224 	counter_u64_free(rack_ack_total);
3225 	counter_u64_free(rack_express_sack);
3226 	counter_u64_free(rack_sack_total);
3227 	counter_u64_free(rack_move_none);
3228 	counter_u64_free(rack_move_some);
3229 	counter_u64_free(rack_sack_attacks_detected);
3230 	counter_u64_free(rack_sack_attacks_reversed);
3231 	counter_u64_free(rack_sack_attacks_suspect);
3232 	counter_u64_free(rack_sack_used_next_merge);
3233 	counter_u64_free(rack_sack_used_prev_merge);
3234 	counter_u64_free(rack_tlp_tot);
3235 	counter_u64_free(rack_tlp_newdata);
3236 	counter_u64_free(rack_tlp_retran);
3237 	counter_u64_free(rack_tlp_retran_bytes);
3238 	counter_u64_free(rack_to_tot);
3239 	counter_u64_free(rack_saw_enobuf);
3240 	counter_u64_free(rack_saw_enobuf_hw);
3241 	counter_u64_free(rack_saw_enetunreach);
3242 	counter_u64_free(rack_hot_alloc);
3243 	counter_u64_free(rack_to_alloc);
3244 	counter_u64_free(rack_to_alloc_hard);
3245 	counter_u64_free(rack_to_alloc_emerg);
3246 	counter_u64_free(rack_to_alloc_limited);
3247 	counter_u64_free(rack_alloc_limited_conns);
3248 	counter_u64_free(rack_split_limited);
3249 	counter_u64_free(rack_multi_single_eq);
3250 	counter_u64_free(rack_rxt_clamps_cwnd);
3251 	counter_u64_free(rack_rxt_clamps_cwnd_uniq);
3252 	counter_u64_free(rack_proc_non_comp_ack);
3253 	counter_u64_free(rack_sack_proc_all);
3254 	counter_u64_free(rack_sack_proc_restart);
3255 	counter_u64_free(rack_sack_proc_short);
3256 	counter_u64_free(rack_sack_skipped_acked);
3257 	counter_u64_free(rack_sack_splits);
3258 	counter_u64_free(rack_input_idle_reduces);
3259 	counter_u64_free(rack_collapsed_win);
3260 	counter_u64_free(rack_collapsed_win_rxt);
3261 	counter_u64_free(rack_collapsed_win_rxt_bytes);
3262 	counter_u64_free(rack_collapsed_win_seen);
3263 	counter_u64_free(rack_try_scwnd);
3264 	counter_u64_free(rack_persists_sends);
3265 	counter_u64_free(rack_persists_acks);
3266 	counter_u64_free(rack_persists_loss);
3267 	counter_u64_free(rack_persists_lost_ends);
3268 #ifdef INVARIANTS
3269 	counter_u64_free(rack_adjust_map_bw);
3270 #endif
3271 	COUNTER_ARRAY_FREE(rack_out_size, TCP_MSS_ACCT_SIZE);
3272 	COUNTER_ARRAY_FREE(rack_opts_arry, RACK_OPTS_SIZE);
3273 }
3274 
3275 static struct rack_sendmap *
3276 rack_alloc(struct tcp_rack *rack)
3277 {
3278 	struct rack_sendmap *rsm;
3279 
3280 	/*
3281 	 * First get the top of the list it in
3282 	 * theory is the "hottest" rsm we have,
3283 	 * possibly just freed by ack processing.
3284 	 */
3285 	if (rack->rc_free_cnt > rack_free_cache) {
3286 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
3287 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
3288 		counter_u64_add(rack_hot_alloc, 1);
3289 		rack->rc_free_cnt--;
3290 		return (rsm);
3291 	}
3292 	/*
3293 	 * Once we get under our free cache we probably
3294 	 * no longer have a "hot" one available. Lets
3295 	 * get one from UMA.
3296 	 */
3297 	rsm = uma_zalloc(rack_zone, M_NOWAIT);
3298 	if (rsm) {
3299 		rack->r_ctl.rc_num_maps_alloced++;
3300 		counter_u64_add(rack_to_alloc, 1);
3301 		return (rsm);
3302 	}
3303 	/*
3304 	 * Dig in to our aux rsm's (the last two) since
3305 	 * UMA failed to get us one.
3306 	 */
3307 	if (rack->rc_free_cnt) {
3308 		counter_u64_add(rack_to_alloc_emerg, 1);
3309 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
3310 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
3311 		rack->rc_free_cnt--;
3312 		return (rsm);
3313 	}
3314 	return (NULL);
3315 }
3316 
3317 static struct rack_sendmap *
3318 rack_alloc_full_limit(struct tcp_rack *rack)
3319 {
3320 	if ((V_tcp_map_entries_limit > 0) &&
3321 	    (rack->do_detection == 0) &&
3322 	    (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
3323 		counter_u64_add(rack_to_alloc_limited, 1);
3324 		if (!rack->alloc_limit_reported) {
3325 			rack->alloc_limit_reported = 1;
3326 			counter_u64_add(rack_alloc_limited_conns, 1);
3327 		}
3328 		return (NULL);
3329 	}
3330 	return (rack_alloc(rack));
3331 }
3332 
3333 /* wrapper to allocate a sendmap entry, subject to a specific limit */
3334 static struct rack_sendmap *
3335 rack_alloc_limit(struct tcp_rack *rack, uint8_t limit_type)
3336 {
3337 	struct rack_sendmap *rsm;
3338 
3339 	if (limit_type) {
3340 		/* currently there is only one limit type */
3341 		if (rack->r_ctl.rc_split_limit > 0 &&
3342 		    (rack->do_detection == 0) &&
3343 		    rack->r_ctl.rc_num_split_allocs >= rack->r_ctl.rc_split_limit) {
3344 			counter_u64_add(rack_split_limited, 1);
3345 			if (!rack->alloc_limit_reported) {
3346 				rack->alloc_limit_reported = 1;
3347 				counter_u64_add(rack_alloc_limited_conns, 1);
3348 			}
3349 			return (NULL);
3350 #ifdef TCP_SAD_DETECTION
3351 		} else if ((tcp_sad_limit != 0) &&
3352 			   (rack->do_detection == 1) &&
3353 			   (rack->r_ctl.rc_num_split_allocs >= tcp_sad_limit)) {
3354 			counter_u64_add(rack_split_limited, 1);
3355 			if (!rack->alloc_limit_reported) {
3356 				rack->alloc_limit_reported = 1;
3357 				counter_u64_add(rack_alloc_limited_conns, 1);
3358 			}
3359 			return (NULL);
3360 #endif
3361 		}
3362 	}
3363 
3364 	/* allocate and mark in the limit type, if set */
3365 	rsm = rack_alloc(rack);
3366 	if (rsm != NULL && limit_type) {
3367 		rsm->r_limit_type = limit_type;
3368 		rack->r_ctl.rc_num_split_allocs++;
3369 	}
3370 	return (rsm);
3371 }
3372 
3373 static void
3374 rack_free_trim(struct tcp_rack *rack)
3375 {
3376 	struct rack_sendmap *rsm;
3377 
3378 	/*
3379 	 * Free up all the tail entries until
3380 	 * we get our list down to the limit.
3381 	 */
3382 	while (rack->rc_free_cnt > rack_free_cache) {
3383 		rsm = TAILQ_LAST(&rack->r_ctl.rc_free, rack_head);
3384 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
3385 		rack->rc_free_cnt--;
3386 		rack->r_ctl.rc_num_maps_alloced--;
3387 		uma_zfree(rack_zone, rsm);
3388 	}
3389 }
3390 
3391 static void
3392 rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm)
3393 {
3394 	if (rsm->r_flags & RACK_APP_LIMITED) {
3395 		if (rack->r_ctl.rc_app_limited_cnt > 0) {
3396 			rack->r_ctl.rc_app_limited_cnt--;
3397 		}
3398 	}
3399 	if (rsm->r_limit_type) {
3400 		/* currently there is only one limit type */
3401 		rack->r_ctl.rc_num_split_allocs--;
3402 	}
3403 	if (rsm == rack->r_ctl.rc_first_appl) {
3404 		if (rack->r_ctl.rc_app_limited_cnt == 0)
3405 			rack->r_ctl.rc_first_appl = NULL;
3406 		else
3407 			rack->r_ctl.rc_first_appl = tqhash_find(rack->r_ctl.tqh, rsm->r_nseq_appl);
3408 	}
3409 	if (rsm == rack->r_ctl.rc_resend)
3410 		rack->r_ctl.rc_resend = NULL;
3411 	if (rsm == rack->r_ctl.rc_end_appl)
3412 		rack->r_ctl.rc_end_appl = NULL;
3413 	if (rack->r_ctl.rc_tlpsend == rsm)
3414 		rack->r_ctl.rc_tlpsend = NULL;
3415 	if (rack->r_ctl.rc_sacklast == rsm)
3416 		rack->r_ctl.rc_sacklast = NULL;
3417 	memset(rsm, 0, sizeof(struct rack_sendmap));
3418 	/* Make sure we are not going to overrun our count limit of 0xff */
3419 	if ((rack->rc_free_cnt + 1) > 0xff) {
3420 		rack_free_trim(rack);
3421 	}
3422 	TAILQ_INSERT_HEAD(&rack->r_ctl.rc_free, rsm, r_tnext);
3423 	rack->rc_free_cnt++;
3424 }
3425 
3426 static uint32_t
3427 rack_get_measure_window(struct tcpcb *tp, struct tcp_rack *rack)
3428 {
3429 	uint64_t srtt, bw, len, tim;
3430 	uint32_t segsiz, def_len, minl;
3431 
3432 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
3433 	def_len = rack_def_data_window * segsiz;
3434 	if (rack->rc_gp_filled == 0) {
3435 		/*
3436 		 * We have no measurement (IW is in flight?) so
3437 		 * we can only guess using our data_window sysctl
3438 		 * value (usually 20MSS).
3439 		 */
3440 		return (def_len);
3441 	}
3442 	/*
3443 	 * Now we have a number of factors to consider.
3444 	 *
3445 	 * 1) We have a desired BDP which is usually
3446 	 *    at least 2.
3447 	 * 2) We have a minimum number of rtt's usually 1 SRTT
3448 	 *    but we allow it too to be more.
3449 	 * 3) We want to make sure a measurement last N useconds (if
3450 	 *    we have set rack_min_measure_usec.
3451 	 *
3452 	 * We handle the first concern here by trying to create a data
3453 	 * window of max(rack_def_data_window, DesiredBDP). The
3454 	 * second concern we handle in not letting the measurement
3455 	 * window end normally until at least the required SRTT's
3456 	 * have gone by which is done further below in
3457 	 * rack_enough_for_measurement(). Finally the third concern
3458 	 * we also handle here by calculating how long that time
3459 	 * would take at the current BW and then return the
3460 	 * max of our first calculation and that length. Note
3461 	 * that if rack_min_measure_usec is 0, we don't deal
3462 	 * with concern 3. Also for both Concern 1 and 3 an
3463 	 * application limited period could end the measurement
3464 	 * earlier.
3465 	 *
3466 	 * So lets calculate the BDP with the "known" b/w using
3467 	 * the SRTT has our rtt and then multiply it by the
3468 	 * goal.
3469 	 */
3470 	bw = rack_get_bw(rack);
3471 	srtt = (uint64_t)tp->t_srtt;
3472 	len = bw * srtt;
3473 	len /= (uint64_t)HPTS_USEC_IN_SEC;
3474 	len *= max(1, rack_goal_bdp);
3475 	/* Now we need to round up to the nearest MSS */
3476 	len = roundup(len, segsiz);
3477 	if (rack_min_measure_usec) {
3478 		/* Now calculate our min length for this b/w */
3479 		tim = rack_min_measure_usec;
3480 		minl = (tim * bw) / (uint64_t)HPTS_USEC_IN_SEC;
3481 		if (minl == 0)
3482 			minl = 1;
3483 		minl = roundup(minl, segsiz);
3484 		if (len < minl)
3485 			len = minl;
3486 	}
3487 	/*
3488 	 * Now if we have a very small window we want
3489 	 * to attempt to get the window that is
3490 	 * as small as possible. This happens on
3491 	 * low b/w connections and we don't want to
3492 	 * span huge numbers of rtt's between measurements.
3493 	 *
3494 	 * We basically include 2 over our "MIN window" so
3495 	 * that the measurement can be shortened (possibly) by
3496 	 * an ack'ed packet.
3497 	 */
3498 	if (len < def_len)
3499 		return (max((uint32_t)len, ((MIN_GP_WIN+2) * segsiz)));
3500 	else
3501 		return (max((uint32_t)len, def_len));
3502 
3503 }
3504 
3505 static int
3506 rack_enough_for_measurement(struct tcpcb *tp, struct tcp_rack *rack, tcp_seq th_ack, uint8_t *quality)
3507 {
3508 	uint32_t tim, srtts, segsiz;
3509 
3510 	/*
3511 	 * Has enough time passed for the GP measurement to be valid?
3512 	 */
3513 	if (SEQ_LT(th_ack, tp->gput_seq)) {
3514 		/* Not enough bytes yet */
3515 		return (0);
3516 	}
3517 	if ((tp->snd_max == tp->snd_una) ||
3518 	    (th_ack == tp->snd_max)){
3519 		/*
3520 		 * All is acked quality of all acked is
3521 		 * usually low or medium, but we in theory could split
3522 		 * all acked into two cases, where you got
3523 		 * a signifigant amount of your window and
3524 		 * where you did not. For now we leave it
3525 		 * but it is something to contemplate in the
3526 		 * future. The danger here is that delayed ack
3527 		 * is effecting the last byte (which is a 50:50 chance).
3528 		 */
3529 		*quality = RACK_QUALITY_ALLACKED;
3530 		return (1);
3531 	}
3532 	if (SEQ_GEQ(th_ack,  tp->gput_ack)) {
3533 		/*
3534 		 * We obtained our entire window of data we wanted
3535 		 * no matter if we are in recovery or not then
3536 		 * its ok since expanding the window does not
3537 		 * make things fuzzy (or at least not as much).
3538 		 */
3539 		*quality = RACK_QUALITY_HIGH;
3540 		return (1);
3541 	}
3542 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
3543 	if (SEQ_LT(th_ack, tp->gput_ack) &&
3544 	    ((th_ack - tp->gput_seq) < max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
3545 		/* Not enough bytes yet */
3546 		return (0);
3547 	}
3548 	if (rack->r_ctl.rc_first_appl &&
3549 	    (SEQ_GEQ(th_ack, rack->r_ctl.rc_first_appl->r_end))) {
3550 		/*
3551 		 * We are up to the app limited send point
3552 		 * we have to measure irrespective of the time..
3553 		 */
3554 		*quality = RACK_QUALITY_APPLIMITED;
3555 		return (1);
3556 	}
3557 	/* Now what about time? */
3558 	srtts = (rack->r_ctl.rc_gp_srtt * rack_min_srtts);
3559 	tim = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - tp->gput_ts;
3560 	if ((tim >= srtts) && (IN_RECOVERY(rack->rc_tp->t_flags) == 0)) {
3561 		/*
3562 		 * We do not allow a measurement if we are in recovery
3563 		 * that would shrink the goodput window we wanted.
3564 		 * This is to prevent cloudyness of when the last send
3565 		 * was actually made.
3566 		 */
3567 		*quality = RACK_QUALITY_HIGH;
3568 		return (1);
3569 	}
3570 	/* Nope not even a full SRTT has passed */
3571 	return (0);
3572 }
3573 
3574 static void
3575 rack_log_timely(struct tcp_rack *rack,
3576 		uint32_t logged, uint64_t cur_bw, uint64_t low_bnd,
3577 		uint64_t up_bnd, int line, uint8_t method)
3578 {
3579 	if (tcp_bblogging_on(rack->rc_tp)) {
3580 		union tcp_log_stackspecific log;
3581 		struct timeval tv;
3582 
3583 		memset(&log, 0, sizeof(log));
3584 		log.u_bbr.flex1 = logged;
3585 		log.u_bbr.flex2 = rack->rc_gp_timely_inc_cnt;
3586 		log.u_bbr.flex2 <<= 4;
3587 		log.u_bbr.flex2 |= rack->rc_gp_timely_dec_cnt;
3588 		log.u_bbr.flex2 <<= 4;
3589 		log.u_bbr.flex2 |= rack->rc_gp_incr;
3590 		log.u_bbr.flex2 <<= 4;
3591 		log.u_bbr.flex2 |= rack->rc_gp_bwred;
3592 		log.u_bbr.flex3 = rack->rc_gp_incr;
3593 		log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
3594 		log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ca;
3595 		log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_rec;
3596 		log.u_bbr.flex7 = rack->rc_gp_bwred;
3597 		log.u_bbr.flex8 = method;
3598 		log.u_bbr.cur_del_rate = cur_bw;
3599 		log.u_bbr.delRate = low_bnd;
3600 		log.u_bbr.bw_inuse = up_bnd;
3601 		log.u_bbr.rttProp = rack_get_bw(rack);
3602 		log.u_bbr.pkt_epoch = line;
3603 		log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
3604 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3605 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3606 		log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
3607 		log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
3608 		log.u_bbr.cwnd_gain = rack->rc_dragged_bottom;
3609 		log.u_bbr.cwnd_gain <<= 1;
3610 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_rec;
3611 		log.u_bbr.cwnd_gain <<= 1;
3612 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
3613 		log.u_bbr.cwnd_gain <<= 1;
3614 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
3615 		log.u_bbr.lost = rack->r_ctl.rc_loss_count;
3616 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3617 		    &rack->rc_inp->inp_socket->so_rcv,
3618 		    &rack->rc_inp->inp_socket->so_snd,
3619 		    TCP_TIMELY_WORK, 0,
3620 		    0, &log, false, &tv);
3621 	}
3622 }
3623 
3624 static int
3625 rack_bw_can_be_raised(struct tcp_rack *rack, uint64_t cur_bw, uint64_t last_bw_est, uint16_t mult)
3626 {
3627 	/*
3628 	 * Before we increase we need to know if
3629 	 * the estimate just made was less than
3630 	 * our pacing goal (i.e. (cur_bw * mult) > last_bw_est)
3631 	 *
3632 	 * If we already are pacing at a fast enough
3633 	 * rate to push us faster there is no sense of
3634 	 * increasing.
3635 	 *
3636 	 * We first caculate our actual pacing rate (ss or ca multiplier
3637 	 * times our cur_bw).
3638 	 *
3639 	 * Then we take the last measured rate and multipy by our
3640 	 * maximum pacing overage to give us a max allowable rate.
3641 	 *
3642 	 * If our act_rate is smaller than our max_allowable rate
3643 	 * then we should increase. Else we should hold steady.
3644 	 *
3645 	 */
3646 	uint64_t act_rate, max_allow_rate;
3647 
3648 	if (rack_timely_no_stopping)
3649 		return (1);
3650 
3651 	if ((cur_bw == 0) || (last_bw_est == 0)) {
3652 		/*
3653 		 * Initial startup case or
3654 		 * everything is acked case.
3655 		 */
3656 		rack_log_timely(rack,  mult, cur_bw, 0, 0,
3657 				__LINE__, 9);
3658 		return (1);
3659 	}
3660 	if (mult <= 100) {
3661 		/*
3662 		 * We can always pace at or slightly above our rate.
3663 		 */
3664 		rack_log_timely(rack,  mult, cur_bw, 0, 0,
3665 				__LINE__, 9);
3666 		return (1);
3667 	}
3668 	act_rate = cur_bw * (uint64_t)mult;
3669 	act_rate /= 100;
3670 	max_allow_rate = last_bw_est * ((uint64_t)rack_max_per_above + (uint64_t)100);
3671 	max_allow_rate /= 100;
3672 	if (act_rate < max_allow_rate) {
3673 		/*
3674 		 * Here the rate we are actually pacing at
3675 		 * is smaller than 10% above our last measurement.
3676 		 * This means we are pacing below what we would
3677 		 * like to try to achieve (plus some wiggle room).
3678 		 */
3679 		rack_log_timely(rack,  mult, cur_bw, act_rate, max_allow_rate,
3680 				__LINE__, 9);
3681 		return (1);
3682 	} else {
3683 		/*
3684 		 * Here we are already pacing at least rack_max_per_above(10%)
3685 		 * what we are getting back. This indicates most likely
3686 		 * that we are being limited (cwnd/rwnd/app) and can't
3687 		 * get any more b/w. There is no sense of trying to
3688 		 * raise up the pacing rate its not speeding us up
3689 		 * and we already are pacing faster than we are getting.
3690 		 */
3691 		rack_log_timely(rack,  mult, cur_bw, act_rate, max_allow_rate,
3692 				__LINE__, 8);
3693 		return (0);
3694 	}
3695 }
3696 
3697 static void
3698 rack_validate_multipliers_at_or_above100(struct tcp_rack *rack)
3699 {
3700 	/*
3701 	 * When we drag bottom, we want to assure
3702 	 * that no multiplier is below 1.0, if so
3703 	 * we want to restore it to at least that.
3704 	 */
3705 	if (rack->r_ctl.rack_per_of_gp_rec  < 100) {
3706 		/* This is unlikely we usually do not touch recovery */
3707 		rack->r_ctl.rack_per_of_gp_rec = 100;
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_validate_multipliers_at_or_below_100(struct tcp_rack *rack)
3719 {
3720 	if (rack->r_ctl.rack_per_of_gp_ca > 100) {
3721 		rack->r_ctl.rack_per_of_gp_ca = 100;
3722 	}
3723 	if (rack->r_ctl.rack_per_of_gp_ss > 100) {
3724 		rack->r_ctl.rack_per_of_gp_ss = 100;
3725 	}
3726 }
3727 
3728 static void
3729 rack_increase_bw_mul(struct tcp_rack *rack, int timely_says, uint64_t cur_bw, uint64_t last_bw_est, int override)
3730 {
3731 	int32_t  calc, logged, plus;
3732 
3733 	logged = 0;
3734 
3735 	if (override) {
3736 		/*
3737 		 * override is passed when we are
3738 		 * loosing b/w and making one last
3739 		 * gasp at trying to not loose out
3740 		 * to a new-reno flow.
3741 		 */
3742 		goto extra_boost;
3743 	}
3744 	/* In classic timely we boost by 5x if we have 5 increases in a row, lets not */
3745 	if (rack->rc_gp_incr &&
3746 	    ((rack->rc_gp_timely_inc_cnt + 1) >= RACK_TIMELY_CNT_BOOST)) {
3747 		/*
3748 		 * Reset and get 5 strokes more before the boost. Note
3749 		 * that the count is 0 based so we have to add one.
3750 		 */
3751 extra_boost:
3752 		plus = (uint32_t)rack_gp_increase_per * RACK_TIMELY_CNT_BOOST;
3753 		rack->rc_gp_timely_inc_cnt = 0;
3754 	} else
3755 		plus = (uint32_t)rack_gp_increase_per;
3756 	/* Must be at least 1% increase for true timely increases */
3757 	if ((plus < 1) &&
3758 	    ((rack->r_ctl.rc_rtt_diff <= 0) || (timely_says <= 0)))
3759 		plus = 1;
3760 	if (rack->rc_gp_saw_rec &&
3761 	    (rack->rc_gp_no_rec_chg == 0) &&
3762 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3763 				  rack->r_ctl.rack_per_of_gp_rec)) {
3764 		/* We have been in recovery ding it too */
3765 		calc = rack->r_ctl.rack_per_of_gp_rec + plus;
3766 		if (calc > 0xffff)
3767 			calc = 0xffff;
3768 		logged |= 1;
3769 		rack->r_ctl.rack_per_of_gp_rec = (uint16_t)calc;
3770 		if (rack->r_ctl.rack_per_upper_bound_ca &&
3771 		    (rack->rc_dragged_bottom == 0) &&
3772 		    (rack->r_ctl.rack_per_of_gp_rec > rack->r_ctl.rack_per_upper_bound_ca))
3773 			rack->r_ctl.rack_per_of_gp_rec = rack->r_ctl.rack_per_upper_bound_ca;
3774 	}
3775 	if (rack->rc_gp_saw_ca &&
3776 	    (rack->rc_gp_saw_ss == 0) &&
3777 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3778 				  rack->r_ctl.rack_per_of_gp_ca)) {
3779 		/* In CA */
3780 		calc = rack->r_ctl.rack_per_of_gp_ca + plus;
3781 		if (calc > 0xffff)
3782 			calc = 0xffff;
3783 		logged |= 2;
3784 		rack->r_ctl.rack_per_of_gp_ca = (uint16_t)calc;
3785 		if (rack->r_ctl.rack_per_upper_bound_ca &&
3786 		    (rack->rc_dragged_bottom == 0) &&
3787 		    (rack->r_ctl.rack_per_of_gp_ca > rack->r_ctl.rack_per_upper_bound_ca))
3788 			rack->r_ctl.rack_per_of_gp_ca = rack->r_ctl.rack_per_upper_bound_ca;
3789 	}
3790 	if (rack->rc_gp_saw_ss &&
3791 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3792 				  rack->r_ctl.rack_per_of_gp_ss)) {
3793 		/* In SS */
3794 		calc = rack->r_ctl.rack_per_of_gp_ss + plus;
3795 		if (calc > 0xffff)
3796 			calc = 0xffff;
3797 		rack->r_ctl.rack_per_of_gp_ss = (uint16_t)calc;
3798 		if (rack->r_ctl.rack_per_upper_bound_ss &&
3799 		    (rack->rc_dragged_bottom == 0) &&
3800 		    (rack->r_ctl.rack_per_of_gp_ss > rack->r_ctl.rack_per_upper_bound_ss))
3801 			rack->r_ctl.rack_per_of_gp_ss = rack->r_ctl.rack_per_upper_bound_ss;
3802 		logged |= 4;
3803 	}
3804 	if (logged &&
3805 	    (rack->rc_gp_incr == 0)){
3806 		/* Go into increment mode */
3807 		rack->rc_gp_incr = 1;
3808 		rack->rc_gp_timely_inc_cnt = 0;
3809 	}
3810 	if (rack->rc_gp_incr &&
3811 	    logged &&
3812 	    (rack->rc_gp_timely_inc_cnt < RACK_TIMELY_CNT_BOOST)) {
3813 		rack->rc_gp_timely_inc_cnt++;
3814 	}
3815 	rack_log_timely(rack,  logged, plus, 0, 0,
3816 			__LINE__, 1);
3817 }
3818 
3819 static uint32_t
3820 rack_get_decrease(struct tcp_rack *rack, uint32_t curper, int32_t rtt_diff)
3821 {
3822 	/*
3823 	 * norm_grad = rtt_diff / minrtt;
3824 	 * new_per = curper * (1 - B * norm_grad)
3825 	 *
3826 	 * B = rack_gp_decrease_per (default 10%)
3827 	 * rtt_dif = input var current rtt-diff
3828 	 * curper = input var current percentage
3829 	 * minrtt = from rack filter
3830 	 *
3831 	 */
3832 	uint64_t perf;
3833 
3834 	perf = (((uint64_t)curper * ((uint64_t)1000000 -
3835 		    ((uint64_t)rack_gp_decrease_per * (uint64_t)10000 *
3836 		     (((uint64_t)rtt_diff * (uint64_t)1000000)/
3837 		      (uint64_t)get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt)))/
3838 		     (uint64_t)1000000)) /
3839 		(uint64_t)1000000);
3840 	if (perf > curper) {
3841 		/* TSNH */
3842 		perf = curper - 1;
3843 	}
3844 	return ((uint32_t)perf);
3845 }
3846 
3847 static uint32_t
3848 rack_decrease_highrtt(struct tcp_rack *rack, uint32_t curper, uint32_t rtt)
3849 {
3850 	/*
3851 	 *                                   highrttthresh
3852 	 * result = curper * (1 - (B * ( 1 -  ------          ))
3853 	 *                                     gp_srtt
3854 	 *
3855 	 * B = rack_gp_decrease_per (default 10%)
3856 	 * highrttthresh = filter_min * rack_gp_rtt_maxmul
3857 	 */
3858 	uint64_t perf;
3859 	uint32_t highrttthresh;
3860 
3861 	highrttthresh = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
3862 
3863 	perf = (((uint64_t)curper * ((uint64_t)1000000 -
3864 				     ((uint64_t)rack_gp_decrease_per * ((uint64_t)1000000 -
3865 					((uint64_t)highrttthresh * (uint64_t)1000000) /
3866 						    (uint64_t)rtt)) / 100)) /(uint64_t)1000000);
3867 	return (perf);
3868 }
3869 
3870 static void
3871 rack_decrease_bw_mul(struct tcp_rack *rack, int timely_says, uint32_t rtt, int32_t rtt_diff)
3872 {
3873 	uint64_t logvar, logvar2, logvar3;
3874 	uint32_t logged, new_per, ss_red, ca_red, rec_red, alt, val;
3875 
3876 	if (rack->rc_gp_incr) {
3877 		/* Turn off increment counting */
3878 		rack->rc_gp_incr = 0;
3879 		rack->rc_gp_timely_inc_cnt = 0;
3880 	}
3881 	ss_red = ca_red = rec_red = 0;
3882 	logged = 0;
3883 	/* Calculate the reduction value */
3884 	if (rtt_diff < 0) {
3885 		rtt_diff *= -1;
3886 	}
3887 	/* Must be at least 1% reduction */
3888 	if (rack->rc_gp_saw_rec && (rack->rc_gp_no_rec_chg == 0)) {
3889 		/* We have been in recovery ding it too */
3890 		if (timely_says == 2) {
3891 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_rec, rtt);
3892 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3893 			if (alt < new_per)
3894 				val = alt;
3895 			else
3896 				val = new_per;
3897 		} else
3898 			 val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3899 		if (rack->r_ctl.rack_per_of_gp_rec > val) {
3900 			rec_red = (rack->r_ctl.rack_per_of_gp_rec - val);
3901 			rack->r_ctl.rack_per_of_gp_rec = (uint16_t)val;
3902 		} else {
3903 			rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
3904 			rec_red = 0;
3905 		}
3906 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_rec)
3907 			rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
3908 		logged |= 1;
3909 	}
3910 	if (rack->rc_gp_saw_ss) {
3911 		/* Sent in SS */
3912 		if (timely_says == 2) {
3913 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ss, rtt);
3914 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3915 			if (alt < new_per)
3916 				val = alt;
3917 			else
3918 				val = new_per;
3919 		} else
3920 			val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ss, rtt_diff);
3921 		if (rack->r_ctl.rack_per_of_gp_ss > new_per) {
3922 			ss_red = rack->r_ctl.rack_per_of_gp_ss - val;
3923 			rack->r_ctl.rack_per_of_gp_ss = (uint16_t)val;
3924 		} else {
3925 			ss_red = new_per;
3926 			rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
3927 			logvar = new_per;
3928 			logvar <<= 32;
3929 			logvar |= alt;
3930 			logvar2 = (uint32_t)rtt;
3931 			logvar2 <<= 32;
3932 			logvar2 |= (uint32_t)rtt_diff;
3933 			logvar3 = rack_gp_rtt_maxmul;
3934 			logvar3 <<= 32;
3935 			logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3936 			rack_log_timely(rack, timely_says,
3937 					logvar2, logvar3,
3938 					logvar, __LINE__, 10);
3939 		}
3940 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ss)
3941 			rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
3942 		logged |= 4;
3943 	} else if (rack->rc_gp_saw_ca) {
3944 		/* Sent in CA */
3945 		if (timely_says == 2) {
3946 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ca, rtt);
3947 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3948 			if (alt < new_per)
3949 				val = alt;
3950 			else
3951 				val = new_per;
3952 		} else
3953 			val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ca, rtt_diff);
3954 		if (rack->r_ctl.rack_per_of_gp_ca > val) {
3955 			ca_red = rack->r_ctl.rack_per_of_gp_ca - val;
3956 			rack->r_ctl.rack_per_of_gp_ca = (uint16_t)val;
3957 		} else {
3958 			rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
3959 			ca_red = 0;
3960 			logvar = new_per;
3961 			logvar <<= 32;
3962 			logvar |= alt;
3963 			logvar2 = (uint32_t)rtt;
3964 			logvar2 <<= 32;
3965 			logvar2 |= (uint32_t)rtt_diff;
3966 			logvar3 = rack_gp_rtt_maxmul;
3967 			logvar3 <<= 32;
3968 			logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3969 			rack_log_timely(rack, timely_says,
3970 					logvar2, logvar3,
3971 					logvar, __LINE__, 10);
3972 		}
3973 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ca)
3974 			rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
3975 		logged |= 2;
3976 	}
3977 	if (rack->rc_gp_timely_dec_cnt < 0x7) {
3978 		rack->rc_gp_timely_dec_cnt++;
3979 		if (rack_timely_dec_clear &&
3980 		    (rack->rc_gp_timely_dec_cnt == rack_timely_dec_clear))
3981 			rack->rc_gp_timely_dec_cnt = 0;
3982 	}
3983 	logvar = ss_red;
3984 	logvar <<= 32;
3985 	logvar |= ca_red;
3986 	rack_log_timely(rack,  logged, rec_red, rack_per_lower_bound, logvar,
3987 			__LINE__, 2);
3988 }
3989 
3990 static void
3991 rack_log_rtt_shrinks(struct tcp_rack *rack, uint32_t us_cts,
3992 		     uint32_t rtt, uint32_t line, uint8_t reas)
3993 {
3994 	if (tcp_bblogging_on(rack->rc_tp)) {
3995 		union tcp_log_stackspecific log;
3996 		struct timeval tv;
3997 
3998 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3999 		log.u_bbr.flex1 = line;
4000 		log.u_bbr.flex2 = rack->r_ctl.rc_time_probertt_starts;
4001 		log.u_bbr.flex3 = rack->r_ctl.rc_lower_rtt_us_cts;
4002 		log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
4003 		log.u_bbr.flex5 = rtt;
4004 		log.u_bbr.flex6 = rack->rc_highly_buffered;
4005 		log.u_bbr.flex6 <<= 1;
4006 		log.u_bbr.flex6 |= rack->forced_ack;
4007 		log.u_bbr.flex6 <<= 1;
4008 		log.u_bbr.flex6 |= rack->rc_gp_dyn_mul;
4009 		log.u_bbr.flex6 <<= 1;
4010 		log.u_bbr.flex6 |= rack->in_probe_rtt;
4011 		log.u_bbr.flex6 <<= 1;
4012 		log.u_bbr.flex6 |= rack->measure_saw_probe_rtt;
4013 		log.u_bbr.flex7 = rack->r_ctl.rack_per_of_gp_probertt;
4014 		log.u_bbr.pacing_gain = rack->r_ctl.rack_per_of_gp_ca;
4015 		log.u_bbr.cwnd_gain = rack->r_ctl.rack_per_of_gp_rec;
4016 		log.u_bbr.flex8 = reas;
4017 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
4018 		log.u_bbr.delRate = rack_get_bw(rack);
4019 		log.u_bbr.cur_del_rate = rack->r_ctl.rc_highest_us_rtt;
4020 		log.u_bbr.cur_del_rate <<= 32;
4021 		log.u_bbr.cur_del_rate |= rack->r_ctl.rc_lowest_us_rtt;
4022 		log.u_bbr.applimited = rack->r_ctl.rc_time_probertt_entered;
4023 		log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
4024 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
4025 		log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
4026 		log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
4027 		log.u_bbr.pkt_epoch = rack->r_ctl.rc_lower_rtt_us_cts;
4028 		log.u_bbr.delivered = rack->r_ctl.rc_target_probertt_flight;
4029 		log.u_bbr.lost = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
4030 		log.u_bbr.rttProp = us_cts;
4031 		log.u_bbr.rttProp <<= 32;
4032 		log.u_bbr.rttProp |= rack->r_ctl.rc_entry_gp_rtt;
4033 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
4034 		    &rack->rc_inp->inp_socket->so_rcv,
4035 		    &rack->rc_inp->inp_socket->so_snd,
4036 		    BBR_LOG_RTT_SHRINKS, 0,
4037 		    0, &log, false, &rack->r_ctl.act_rcv_time);
4038 	}
4039 }
4040 
4041 static void
4042 rack_set_prtt_target(struct tcp_rack *rack, uint32_t segsiz, uint32_t rtt)
4043 {
4044 	uint64_t bwdp;
4045 
4046 	bwdp = rack_get_bw(rack);
4047 	bwdp *= (uint64_t)rtt;
4048 	bwdp /= (uint64_t)HPTS_USEC_IN_SEC;
4049 	rack->r_ctl.rc_target_probertt_flight = roundup((uint32_t)bwdp, segsiz);
4050 	if (rack->r_ctl.rc_target_probertt_flight < (segsiz * rack_timely_min_segs)) {
4051 		/*
4052 		 * A window protocol must be able to have 4 packets
4053 		 * outstanding as the floor in order to function
4054 		 * (especially considering delayed ack :D).
4055 		 */
4056 		rack->r_ctl.rc_target_probertt_flight = (segsiz * rack_timely_min_segs);
4057 	}
4058 }
4059 
4060 static void
4061 rack_enter_probertt(struct tcp_rack *rack, uint32_t us_cts)
4062 {
4063 	/**
4064 	 * ProbeRTT is a bit different in rack_pacing than in
4065 	 * BBR. It is like BBR in that it uses the lowering of
4066 	 * the RTT as a signal that we saw something new and
4067 	 * counts from there for how long between. But it is
4068 	 * different in that its quite simple. It does not
4069 	 * play with the cwnd and wait until we get down
4070 	 * to N segments outstanding and hold that for
4071 	 * 200ms. Instead it just sets the pacing reduction
4072 	 * rate to a set percentage (70 by default) and hold
4073 	 * that for a number of recent GP Srtt's.
4074 	 */
4075 	uint32_t segsiz;
4076 
4077 	if (rack->rc_gp_dyn_mul == 0)
4078 		return;
4079 
4080 	if (rack->rc_tp->snd_max == rack->rc_tp->snd_una) {
4081 		/* We are idle */
4082 		return;
4083 	}
4084 	if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
4085 	    SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
4086 		/*
4087 		 * Stop the goodput now, the idea here is
4088 		 * that future measurements with in_probe_rtt
4089 		 * won't register if they are not greater so
4090 		 * we want to get what info (if any) is available
4091 		 * now.
4092 		 */
4093 		rack_do_goodput_measurement(rack->rc_tp, rack,
4094 					    rack->rc_tp->snd_una, __LINE__,
4095 					    RACK_QUALITY_PROBERTT);
4096 	}
4097 	rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
4098 	rack->r_ctl.rc_time_probertt_entered = us_cts;
4099 	segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
4100 		     rack->r_ctl.rc_pace_min_segs);
4101 	rack->in_probe_rtt = 1;
4102 	rack->measure_saw_probe_rtt = 1;
4103 	rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
4104 	rack->r_ctl.rc_time_probertt_starts = 0;
4105 	rack->r_ctl.rc_entry_gp_rtt = rack->r_ctl.rc_gp_srtt;
4106 	if (rack_probertt_use_min_rtt_entry)
4107 		rack_set_prtt_target(rack, segsiz, get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
4108 	else
4109 		rack_set_prtt_target(rack, segsiz, rack->r_ctl.rc_gp_srtt);
4110 	rack_log_rtt_shrinks(rack,  us_cts,  get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4111 			     __LINE__, RACK_RTTS_ENTERPROBE);
4112 }
4113 
4114 static void
4115 rack_exit_probertt(struct tcp_rack *rack, uint32_t us_cts)
4116 {
4117 	struct rack_sendmap *rsm;
4118 	uint32_t segsiz;
4119 
4120 	segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
4121 		     rack->r_ctl.rc_pace_min_segs);
4122 	rack->in_probe_rtt = 0;
4123 	if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
4124 	    SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
4125 		/*
4126 		 * Stop the goodput now, the idea here is
4127 		 * that future measurements with in_probe_rtt
4128 		 * won't register if they are not greater so
4129 		 * we want to get what info (if any) is available
4130 		 * now.
4131 		 */
4132 		rack_do_goodput_measurement(rack->rc_tp, rack,
4133 					    rack->rc_tp->snd_una, __LINE__,
4134 					    RACK_QUALITY_PROBERTT);
4135 	} else if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
4136 		/*
4137 		 * We don't have enough data to make a measurement.
4138 		 * So lets just stop and start here after exiting
4139 		 * probe-rtt. We probably are not interested in
4140 		 * the results anyway.
4141 		 */
4142 		rack->rc_tp->t_flags &= ~TF_GPUTINPROG;
4143 	}
4144 	/*
4145 	 * Measurements through the current snd_max are going
4146 	 * to be limited by the slower pacing rate.
4147 	 *
4148 	 * We need to mark these as app-limited so we
4149 	 * don't collapse the b/w.
4150 	 */
4151 	rsm = tqhash_max(rack->r_ctl.tqh);
4152 	if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
4153 		if (rack->r_ctl.rc_app_limited_cnt == 0)
4154 			rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
4155 		else {
4156 			/*
4157 			 * Go out to the end app limited and mark
4158 			 * this new one as next and move the end_appl up
4159 			 * to this guy.
4160 			 */
4161 			if (rack->r_ctl.rc_end_appl)
4162 				rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
4163 			rack->r_ctl.rc_end_appl = rsm;
4164 		}
4165 		rsm->r_flags |= RACK_APP_LIMITED;
4166 		rack->r_ctl.rc_app_limited_cnt++;
4167 	}
4168 	/*
4169 	 * Now, we need to examine our pacing rate multipliers.
4170 	 * If its under 100%, we need to kick it back up to
4171 	 * 100%. We also don't let it be over our "max" above
4172 	 * the actual rate i.e. 100% + rack_clamp_atexit_prtt.
4173 	 * Note setting clamp_atexit_prtt to 0 has the effect
4174 	 * of setting CA/SS to 100% always at exit (which is
4175 	 * the default behavior).
4176 	 */
4177 	if (rack_probertt_clear_is) {
4178 		rack->rc_gp_incr = 0;
4179 		rack->rc_gp_bwred = 0;
4180 		rack->rc_gp_timely_inc_cnt = 0;
4181 		rack->rc_gp_timely_dec_cnt = 0;
4182 	}
4183 	/* Do we do any clamping at exit? */
4184 	if (rack->rc_highly_buffered && rack_atexit_prtt_hbp) {
4185 		rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt_hbp;
4186 		rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt_hbp;
4187 	}
4188 	if ((rack->rc_highly_buffered == 0) && rack_atexit_prtt) {
4189 		rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt;
4190 		rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt;
4191 	}
4192 	/*
4193 	 * Lets set rtt_diff to 0, so that we will get a "boost"
4194 	 * after exiting.
4195 	 */
4196 	rack->r_ctl.rc_rtt_diff = 0;
4197 
4198 	/* Clear all flags so we start fresh */
4199 	rack->rc_tp->t_bytes_acked = 0;
4200 	rack->rc_tp->t_ccv.flags &= ~CCF_ABC_SENTAWND;
4201 	/*
4202 	 * If configured to, set the cwnd and ssthresh to
4203 	 * our targets.
4204 	 */
4205 	if (rack_probe_rtt_sets_cwnd) {
4206 		uint64_t ebdp;
4207 		uint32_t setto;
4208 
4209 		/* Set ssthresh so we get into CA once we hit our target */
4210 		if (rack_probertt_use_min_rtt_exit == 1) {
4211 			/* Set to min rtt */
4212 			rack_set_prtt_target(rack, segsiz,
4213 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
4214 		} else if (rack_probertt_use_min_rtt_exit == 2) {
4215 			/* Set to current gp rtt */
4216 			rack_set_prtt_target(rack, segsiz,
4217 					     rack->r_ctl.rc_gp_srtt);
4218 		} else if (rack_probertt_use_min_rtt_exit == 3) {
4219 			/* Set to entry gp rtt */
4220 			rack_set_prtt_target(rack, segsiz,
4221 					     rack->r_ctl.rc_entry_gp_rtt);
4222 		} else {
4223 			uint64_t sum;
4224 			uint32_t setval;
4225 
4226 			sum = rack->r_ctl.rc_entry_gp_rtt;
4227 			sum *= 10;
4228 			sum /= (uint64_t)(max(1, rack->r_ctl.rc_gp_srtt));
4229 			if (sum >= 20) {
4230 				/*
4231 				 * A highly buffered path needs
4232 				 * cwnd space for timely to work.
4233 				 * Lets set things up as if
4234 				 * we are heading back here again.
4235 				 */
4236 				setval = rack->r_ctl.rc_entry_gp_rtt;
4237 			} else if (sum >= 15) {
4238 				/*
4239 				 * Lets take the smaller of the
4240 				 * two since we are just somewhat
4241 				 * buffered.
4242 				 */
4243 				setval = rack->r_ctl.rc_gp_srtt;
4244 				if (setval > rack->r_ctl.rc_entry_gp_rtt)
4245 					setval = rack->r_ctl.rc_entry_gp_rtt;
4246 			} else {
4247 				/*
4248 				 * Here we are not highly buffered
4249 				 * and should pick the min we can to
4250 				 * keep from causing loss.
4251 				 */
4252 				setval = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
4253 			}
4254 			rack_set_prtt_target(rack, segsiz,
4255 					     setval);
4256 		}
4257 		if (rack_probe_rtt_sets_cwnd > 1) {
4258 			/* There is a percentage here to boost */
4259 			ebdp = rack->r_ctl.rc_target_probertt_flight;
4260 			ebdp *= rack_probe_rtt_sets_cwnd;
4261 			ebdp /= 100;
4262 			setto = rack->r_ctl.rc_target_probertt_flight + ebdp;
4263 		} else
4264 			setto = rack->r_ctl.rc_target_probertt_flight;
4265 		rack->rc_tp->snd_cwnd = roundup(setto, segsiz);
4266 		if (rack->rc_tp->snd_cwnd < (segsiz * rack_timely_min_segs)) {
4267 			/* Enforce a min */
4268 			rack->rc_tp->snd_cwnd = segsiz * rack_timely_min_segs;
4269 		}
4270 		/* If we set in the cwnd also set the ssthresh point so we are in CA */
4271 		rack->rc_tp->snd_ssthresh = (rack->rc_tp->snd_cwnd - 1);
4272 	}
4273 	rack_log_rtt_shrinks(rack,  us_cts,
4274 			     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4275 			     __LINE__, RACK_RTTS_EXITPROBE);
4276 	/* Clear times last so log has all the info */
4277 	rack->r_ctl.rc_probertt_sndmax_atexit = rack->rc_tp->snd_max;
4278 	rack->r_ctl.rc_time_probertt_entered = us_cts;
4279 	rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
4280 	rack->r_ctl.rc_time_of_last_probertt = us_cts;
4281 }
4282 
4283 static void
4284 rack_check_probe_rtt(struct tcp_rack *rack, uint32_t us_cts)
4285 {
4286 	/* Check in on probe-rtt */
4287 	if (rack->rc_gp_filled == 0) {
4288 		/* We do not do p-rtt unless we have gp measurements */
4289 		return;
4290 	}
4291 	if (rack->in_probe_rtt) {
4292 		uint64_t no_overflow;
4293 		uint32_t endtime, must_stay;
4294 
4295 		if (rack->r_ctl.rc_went_idle_time &&
4296 		    ((us_cts - rack->r_ctl.rc_went_idle_time) > rack_min_probertt_hold)) {
4297 			/*
4298 			 * We went idle during prtt, just exit now.
4299 			 */
4300 			rack_exit_probertt(rack, us_cts);
4301 		} else if (rack_probe_rtt_safety_val &&
4302 		    TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered) &&
4303 		    ((us_cts - rack->r_ctl.rc_time_probertt_entered) > rack_probe_rtt_safety_val)) {
4304 			/*
4305 			 * Probe RTT safety value triggered!
4306 			 */
4307 			rack_log_rtt_shrinks(rack,  us_cts,
4308 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4309 					     __LINE__, RACK_RTTS_SAFETY);
4310 			rack_exit_probertt(rack, us_cts);
4311 		}
4312 		/* Calculate the max we will wait */
4313 		endtime = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_max_drain_wait);
4314 		if (rack->rc_highly_buffered)
4315 			endtime += (rack->r_ctl.rc_gp_srtt * rack_max_drain_hbp);
4316 		/* Calculate the min we must wait */
4317 		must_stay = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_must_drain);
4318 		if ((ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.rc_target_probertt_flight) &&
4319 		    TSTMP_LT(us_cts, endtime)) {
4320 			uint32_t calc;
4321 			/* Do we lower more? */
4322 no_exit:
4323 			if (TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered))
4324 				calc = us_cts - rack->r_ctl.rc_time_probertt_entered;
4325 			else
4326 				calc = 0;
4327 			calc /= max(rack->r_ctl.rc_gp_srtt, 1);
4328 			if (calc) {
4329 				/* Maybe */
4330 				calc *= rack_per_of_gp_probertt_reduce;
4331 				rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt - calc;
4332 				/* Limit it too */
4333 				if (rack->r_ctl.rack_per_of_gp_probertt < rack_per_of_gp_lowthresh)
4334 					rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_lowthresh;
4335 			}
4336 			/* We must reach target or the time set */
4337 			return;
4338 		}
4339 		if (rack->r_ctl.rc_time_probertt_starts == 0) {
4340 			if ((TSTMP_LT(us_cts, must_stay) &&
4341 			     rack->rc_highly_buffered) ||
4342 			     (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) >
4343 			      rack->r_ctl.rc_target_probertt_flight)) {
4344 				/* We are not past the must_stay time */
4345 				goto no_exit;
4346 			}
4347 			rack_log_rtt_shrinks(rack,  us_cts,
4348 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4349 					     __LINE__, RACK_RTTS_REACHTARGET);
4350 			rack->r_ctl.rc_time_probertt_starts = us_cts;
4351 			if (rack->r_ctl.rc_time_probertt_starts == 0)
4352 				rack->r_ctl.rc_time_probertt_starts = 1;
4353 			/* Restore back to our rate we want to pace at in prtt */
4354 			rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
4355 		}
4356 		/*
4357 		 * Setup our end time, some number of gp_srtts plus 200ms.
4358 		 */
4359 		no_overflow = ((uint64_t)rack->r_ctl.rc_gp_srtt *
4360 			       (uint64_t)rack_probertt_gpsrtt_cnt_mul);
4361 		if (rack_probertt_gpsrtt_cnt_div)
4362 			endtime = (uint32_t)(no_overflow / (uint64_t)rack_probertt_gpsrtt_cnt_div);
4363 		else
4364 			endtime = 0;
4365 		endtime += rack_min_probertt_hold;
4366 		endtime += rack->r_ctl.rc_time_probertt_starts;
4367 		if (TSTMP_GEQ(us_cts,  endtime)) {
4368 			/* yes, exit probertt */
4369 			rack_exit_probertt(rack, us_cts);
4370 		}
4371 
4372 	} else if ((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= rack_time_between_probertt) {
4373 		/* Go into probertt, its been too long since we went lower */
4374 		rack_enter_probertt(rack, us_cts);
4375 	}
4376 }
4377 
4378 static void
4379 rack_update_multiplier(struct tcp_rack *rack, int32_t timely_says, uint64_t last_bw_est,
4380 		       uint32_t rtt, int32_t rtt_diff)
4381 {
4382 	uint64_t cur_bw, up_bnd, low_bnd, subfr;
4383 	uint32_t losses;
4384 
4385 	if ((rack->rc_gp_dyn_mul == 0) ||
4386 	    (rack->use_fixed_rate) ||
4387 	    (rack->in_probe_rtt) ||
4388 	    (rack->rc_always_pace == 0)) {
4389 		/* No dynamic GP multiplier in play */
4390 		return;
4391 	}
4392 	losses = rack->r_ctl.rc_loss_count - rack->r_ctl.rc_loss_at_start;
4393 	cur_bw = rack_get_bw(rack);
4394 	/* Calculate our up and down range */
4395 	up_bnd = rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_up;
4396 	up_bnd /= 100;
4397 	up_bnd += rack->r_ctl.last_gp_comp_bw;
4398 
4399 	subfr = (uint64_t)rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_down;
4400 	subfr /= 100;
4401 	low_bnd = rack->r_ctl.last_gp_comp_bw - subfr;
4402 	if ((timely_says == 2) && (rack->r_ctl.rc_no_push_at_mrtt)) {
4403 		/*
4404 		 * This is the case where our RTT is above
4405 		 * the max target and we have been configured
4406 		 * to just do timely no bonus up stuff in that case.
4407 		 *
4408 		 * There are two configurations, set to 1, and we
4409 		 * just do timely if we are over our max. If its
4410 		 * set above 1 then we slam the multipliers down
4411 		 * to 100 and then decrement per timely.
4412 		 */
4413 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4414 				__LINE__, 3);
4415 		if (rack->r_ctl.rc_no_push_at_mrtt > 1)
4416 			rack_validate_multipliers_at_or_below_100(rack);
4417 		rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
4418 	} else if ((timely_says != 0) && (last_bw_est < low_bnd) && !losses) {
4419 		/*
4420 		 * We are decreasing this is a bit complicated this
4421 		 * means we are loosing ground. This could be
4422 		 * because another flow entered and we are competing
4423 		 * for b/w with it. This will push the RTT up which
4424 		 * makes timely unusable unless we want to get shoved
4425 		 * into a corner and just be backed off (the age
4426 		 * old problem with delay based CC).
4427 		 *
4428 		 * On the other hand if it was a route change we
4429 		 * would like to stay somewhat contained and not
4430 		 * blow out the buffers.
4431 		 */
4432 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4433 				__LINE__, 3);
4434 		rack->r_ctl.last_gp_comp_bw = cur_bw;
4435 		if (rack->rc_gp_bwred == 0) {
4436 			/* Go into reduction counting */
4437 			rack->rc_gp_bwred = 1;
4438 			rack->rc_gp_timely_dec_cnt = 0;
4439 		}
4440 		if (rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) {
4441 			/*
4442 			 * Push another time with a faster pacing
4443 			 * to try to gain back (we include override to
4444 			 * get a full raise factor).
4445 			 */
4446 			if ((rack->rc_gp_saw_ca && rack->r_ctl.rack_per_of_gp_ca <= rack_down_raise_thresh) ||
4447 			    (rack->rc_gp_saw_ss && rack->r_ctl.rack_per_of_gp_ss <= rack_down_raise_thresh) ||
4448 			    (timely_says == 0) ||
4449 			    (rack_down_raise_thresh == 0)) {
4450 				/*
4451 				 * Do an override up in b/w if we were
4452 				 * below the threshold or if the threshold
4453 				 * is zero we always do the raise.
4454 				 */
4455 				rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 1);
4456 			} else {
4457 				/* Log it stays the same */
4458 				rack_log_timely(rack,  0, last_bw_est, low_bnd, 0,
4459 						__LINE__, 11);
4460 			}
4461 			rack->rc_gp_timely_dec_cnt++;
4462 			/* We are not incrementing really no-count */
4463 			rack->rc_gp_incr = 0;
4464 			rack->rc_gp_timely_inc_cnt = 0;
4465 		} else {
4466 			/*
4467 			 * Lets just use the RTT
4468 			 * information and give up
4469 			 * pushing.
4470 			 */
4471 			goto use_timely;
4472 		}
4473 	} else if ((timely_says != 2) &&
4474 		    !losses &&
4475 		    (last_bw_est > up_bnd)) {
4476 		/*
4477 		 * We are increasing b/w lets keep going, updating
4478 		 * our b/w and ignoring any timely input, unless
4479 		 * of course we are at our max raise (if there is one).
4480 		 */
4481 
4482 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4483 				__LINE__, 3);
4484 		rack->r_ctl.last_gp_comp_bw = cur_bw;
4485 		if (rack->rc_gp_saw_ss &&
4486 		    rack->r_ctl.rack_per_upper_bound_ss &&
4487 		     (rack->r_ctl.rack_per_of_gp_ss == rack->r_ctl.rack_per_upper_bound_ss)) {
4488 			    /*
4489 			     * In cases where we can't go higher
4490 			     * we should just use timely.
4491 			     */
4492 			    goto use_timely;
4493 		}
4494 		if (rack->rc_gp_saw_ca &&
4495 		    rack->r_ctl.rack_per_upper_bound_ca &&
4496 		    (rack->r_ctl.rack_per_of_gp_ca == rack->r_ctl.rack_per_upper_bound_ca)) {
4497 			    /*
4498 			     * In cases where we can't go higher
4499 			     * we should just use timely.
4500 			     */
4501 			    goto use_timely;
4502 		}
4503 		rack->rc_gp_bwred = 0;
4504 		rack->rc_gp_timely_dec_cnt = 0;
4505 		/* You get a set number of pushes if timely is trying to reduce */
4506 		if ((rack->rc_gp_incr < rack_timely_max_push_rise) || (timely_says == 0)) {
4507 			rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4508 		} else {
4509 			/* Log it stays the same */
4510 			rack_log_timely(rack,  0, last_bw_est, up_bnd, 0,
4511 			    __LINE__, 12);
4512 		}
4513 		return;
4514 	} else {
4515 		/*
4516 		 * We are staying between the lower and upper range bounds
4517 		 * so use timely to decide.
4518 		 */
4519 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4520 				__LINE__, 3);
4521 use_timely:
4522 		if (timely_says) {
4523 			rack->rc_gp_incr = 0;
4524 			rack->rc_gp_timely_inc_cnt = 0;
4525 			if ((rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) &&
4526 			    !losses &&
4527 			    (last_bw_est < low_bnd)) {
4528 				/* We are loosing ground */
4529 				rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4530 				rack->rc_gp_timely_dec_cnt++;
4531 				/* We are not incrementing really no-count */
4532 				rack->rc_gp_incr = 0;
4533 				rack->rc_gp_timely_inc_cnt = 0;
4534 			} else
4535 				rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
4536 		} else {
4537 			rack->rc_gp_bwred = 0;
4538 			rack->rc_gp_timely_dec_cnt = 0;
4539 			rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4540 		}
4541 	}
4542 }
4543 
4544 static int32_t
4545 rack_make_timely_judgement(struct tcp_rack *rack, uint32_t rtt, int32_t rtt_diff, uint32_t prev_rtt)
4546 {
4547 	int32_t timely_says;
4548 	uint64_t log_mult, log_rtt_a_diff;
4549 
4550 	log_rtt_a_diff = rtt;
4551 	log_rtt_a_diff <<= 32;
4552 	log_rtt_a_diff |= (uint32_t)rtt_diff;
4553 	if (rtt >= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) *
4554 		    rack_gp_rtt_maxmul)) {
4555 		/* Reduce the b/w multiplier */
4556 		timely_says = 2;
4557 		log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
4558 		log_mult <<= 32;
4559 		log_mult |= prev_rtt;
4560 		rack_log_timely(rack,  timely_says, log_mult,
4561 				get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4562 				log_rtt_a_diff, __LINE__, 4);
4563 	} else if (rtt <= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
4564 			   ((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
4565 			    max(rack_gp_rtt_mindiv , 1)))) {
4566 		/* Increase the b/w multiplier */
4567 		log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
4568 			((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
4569 			 max(rack_gp_rtt_mindiv , 1));
4570 		log_mult <<= 32;
4571 		log_mult |= prev_rtt;
4572 		timely_says = 0;
4573 		rack_log_timely(rack,  timely_says, log_mult ,
4574 				get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4575 				log_rtt_a_diff, __LINE__, 5);
4576 	} else {
4577 		/*
4578 		 * Use a gradient to find it the timely gradient
4579 		 * is:
4580 		 * grad = rc_rtt_diff / min_rtt;
4581 		 *
4582 		 * anything below or equal to 0 will be
4583 		 * a increase indication. Anything above
4584 		 * zero is a decrease. Note we take care
4585 		 * of the actual gradient calculation
4586 		 * in the reduction (its not needed for
4587 		 * increase).
4588 		 */
4589 		log_mult = prev_rtt;
4590 		if (rtt_diff <= 0) {
4591 			/*
4592 			 * Rttdiff is less than zero, increase the
4593 			 * b/w multiplier (its 0 or negative)
4594 			 */
4595 			timely_says = 0;
4596 			rack_log_timely(rack,  timely_says, log_mult,
4597 					get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 6);
4598 		} else {
4599 			/* Reduce the b/w multiplier */
4600 			timely_says = 1;
4601 			rack_log_timely(rack,  timely_says, log_mult,
4602 					get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 7);
4603 		}
4604 	}
4605 	return (timely_says);
4606 }
4607 
4608 static __inline int
4609 rack_in_gp_window(struct tcpcb *tp, struct rack_sendmap *rsm)
4610 {
4611 	if (SEQ_GEQ(rsm->r_start, tp->gput_seq) &&
4612 	    SEQ_LEQ(rsm->r_end, tp->gput_ack)) {
4613 		/**
4614 		 * This covers the case that the
4615 		 * resent is completely inside
4616 		 * the gp range or up to it.
4617 		 *      |----------------|
4618 		 *      |-----| <or>
4619 		 *            |----|
4620 		 *            <or>   |---|
4621 		 */
4622 		return (1);
4623 	} else if (SEQ_LT(rsm->r_start, tp->gput_seq) &&
4624 		   SEQ_GT(rsm->r_end, tp->gput_seq)){
4625 		/**
4626 		 * This covers the case of
4627 		 *      |--------------|
4628 		 *  |-------->|
4629 		 */
4630 		return (1);
4631 	} else if (SEQ_GEQ(rsm->r_start, tp->gput_seq) &&
4632 		   SEQ_LT(rsm->r_start, tp->gput_ack) &&
4633 		   SEQ_GEQ(rsm->r_end, tp->gput_ack)) {
4634 
4635 		/**
4636 		 * This covers the case of
4637 		 *      |--------------|
4638 		 *              |-------->|
4639 		 */
4640 		return (1);
4641 	}
4642 	return (0);
4643 }
4644 
4645 static __inline void
4646 rack_mark_in_gp_win(struct tcpcb *tp, struct rack_sendmap *rsm)
4647 {
4648 
4649 	if ((tp->t_flags & TF_GPUTINPROG) == 0)
4650 		return;
4651 	/*
4652 	 * We have a Goodput measurement in progress. Mark
4653 	 * the send if its within the window. If its not
4654 	 * in the window make sure it does not have the mark.
4655 	 */
4656 	if (rack_in_gp_window(tp, rsm))
4657 		rsm->r_flags |= RACK_IN_GP_WIN;
4658 	else
4659 		rsm->r_flags &= ~RACK_IN_GP_WIN;
4660 }
4661 
4662 static __inline void
4663 rack_clear_gp_marks(struct tcpcb *tp, struct tcp_rack *rack)
4664 {
4665 	/* A GP measurement is ending, clear all marks on the send map*/
4666 	struct rack_sendmap *rsm = NULL;
4667 
4668 	rsm = tqhash_find(rack->r_ctl.tqh, tp->gput_seq);
4669 	if (rsm == NULL) {
4670 		rsm = tqhash_min(rack->r_ctl.tqh);
4671 	}
4672 	/* Nothing left? */
4673 	while ((rsm != NULL) && (SEQ_GEQ(tp->gput_ack, rsm->r_start))){
4674 		rsm->r_flags &= ~RACK_IN_GP_WIN;
4675 		rsm = tqhash_next(rack->r_ctl.tqh, rsm);
4676 	}
4677 }
4678 
4679 
4680 static __inline void
4681 rack_tend_gp_marks(struct tcpcb *tp, struct tcp_rack *rack)
4682 {
4683 	struct rack_sendmap *rsm = NULL;
4684 
4685 	if (tp->snd_una == tp->snd_max) {
4686 		/* Nothing outstanding yet, nothing to do here */
4687 		return;
4688 	}
4689 	if (SEQ_GT(tp->gput_seq, tp->snd_una)) {
4690 		/*
4691 		 * We are measuring ahead of some outstanding
4692 		 * data. We need to walk through up until we get
4693 		 * to gp_seq marking so that no rsm is set incorrectly
4694 		 * with RACK_IN_GP_WIN.
4695 		 */
4696 		rsm = tqhash_min(rack->r_ctl.tqh);
4697 		while (rsm != NULL) {
4698 			rack_mark_in_gp_win(tp, rsm);
4699 			if (SEQ_GEQ(rsm->r_end, tp->gput_seq))
4700 				break;
4701 			rsm = tqhash_next(rack->r_ctl.tqh, rsm);
4702 		}
4703 	}
4704 	if (rsm == NULL) {
4705 		/*
4706 		 * Need to find the GP seq, if rsm is
4707 		 * set we stopped as we hit it.
4708 		 */
4709 		rsm = tqhash_find(rack->r_ctl.tqh, tp->gput_seq);
4710 		if (rsm == NULL)
4711 			return;
4712 		rack_mark_in_gp_win(tp, rsm);
4713 	}
4714 	/*
4715 	 * Now we may need to mark already sent rsm, ahead of
4716 	 * gput_seq in the window since they may have been sent
4717 	 * *before* we started our measurment. The rsm, if non-null
4718 	 * has been marked (note if rsm would have been NULL we would have
4719 	 * returned in the previous block). So we go to the next, and continue
4720 	 * until we run out of entries or we exceed the gp_ack value.
4721 	 */
4722 	rsm = tqhash_next(rack->r_ctl.tqh, rsm);
4723 	while (rsm) {
4724 		rack_mark_in_gp_win(tp, rsm);
4725 		if (SEQ_GT(rsm->r_end, tp->gput_ack))
4726 			break;
4727 		rsm = tqhash_next(rack->r_ctl.tqh, rsm);
4728 	}
4729 }
4730 
4731 static void
4732 rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
4733 			    tcp_seq th_ack, int line, uint8_t quality)
4734 {
4735 	uint64_t tim, bytes_ps, stim, utim;
4736 	uint32_t segsiz, bytes, reqbytes, us_cts;
4737 	int32_t gput, new_rtt_diff, timely_says;
4738 	uint64_t  resid_bw, subpart = 0, addpart = 0, srtt;
4739 	int did_add = 0;
4740 
4741 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
4742 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
4743 	if (TSTMP_GEQ(us_cts, tp->gput_ts))
4744 		tim = us_cts - tp->gput_ts;
4745 	else
4746 		tim = 0;
4747 	if (rack->r_ctl.rc_gp_cumack_ts > rack->r_ctl.rc_gp_output_ts)
4748 		stim = rack->r_ctl.rc_gp_cumack_ts - rack->r_ctl.rc_gp_output_ts;
4749 	else
4750 		stim = 0;
4751 	/*
4752 	 * Use the larger of the send time or ack time. This prevents us
4753 	 * from being influenced by ack artifacts to come up with too
4754 	 * high of measurement. Note that since we are spanning over many more
4755 	 * bytes in most of our measurements hopefully that is less likely to
4756 	 * occur.
4757 	 */
4758 	if (tim > stim)
4759 		utim = max(tim, 1);
4760 	else
4761 		utim = max(stim, 1);
4762 	reqbytes = min(rc_init_window(rack), (MIN_GP_WIN * segsiz));
4763 	rack_log_gpset(rack, th_ack, us_cts, rack->r_ctl.rc_gp_cumack_ts, __LINE__, 3, NULL);
4764 	if ((tim == 0) && (stim == 0)) {
4765 		/*
4766 		 * Invalid measurement time, maybe
4767 		 * all on one ack/one send?
4768 		 */
4769 		bytes = 0;
4770 		bytes_ps = 0;
4771 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4772 					   0, 0, 0, 10, __LINE__, NULL, quality);
4773 		goto skip_measurement;
4774 	}
4775 	if (rack->r_ctl.rc_gp_lowrtt == 0xffffffff) {
4776 		/* We never made a us_rtt measurement? */
4777 		bytes = 0;
4778 		bytes_ps = 0;
4779 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4780 					   0, 0, 0, 10, __LINE__, NULL, quality);
4781 		goto skip_measurement;
4782 	}
4783 	/*
4784 	 * Calculate the maximum possible b/w this connection
4785 	 * could have. We base our calculation on the lowest
4786 	 * rtt we have seen during the measurement and the
4787 	 * largest rwnd the client has given us in that time. This
4788 	 * forms a BDP that is the maximum that we could ever
4789 	 * get to the client. Anything larger is not valid.
4790 	 *
4791 	 * I originally had code here that rejected measurements
4792 	 * where the time was less than 1/2 the latest us_rtt.
4793 	 * But after thinking on that I realized its wrong since
4794 	 * say you had a 150Mbps or even 1Gbps link, and you
4795 	 * were a long way away.. example I am in Europe (100ms rtt)
4796 	 * talking to my 1Gbps link in S.C. Now measuring say 150,000
4797 	 * bytes my time would be 1.2ms, and yet my rtt would say
4798 	 * the measurement was invalid the time was < 50ms. The
4799 	 * same thing is true for 150Mb (8ms of time).
4800 	 *
4801 	 * A better way I realized is to look at what the maximum
4802 	 * the connection could possibly do. This is gated on
4803 	 * the lowest RTT we have seen and the highest rwnd.
4804 	 * We should in theory never exceed that, if we are
4805 	 * then something on the path is storing up packets
4806 	 * and then feeding them all at once to our endpoint
4807 	 * messing up our measurement.
4808 	 */
4809 	rack->r_ctl.last_max_bw = rack->r_ctl.rc_gp_high_rwnd;
4810 	rack->r_ctl.last_max_bw *= HPTS_USEC_IN_SEC;
4811 	rack->r_ctl.last_max_bw /= rack->r_ctl.rc_gp_lowrtt;
4812 	if (SEQ_LT(th_ack, tp->gput_seq)) {
4813 		/* No measurement can be made */
4814 		bytes = 0;
4815 		bytes_ps = 0;
4816 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4817 					   0, 0, 0, 10, __LINE__, NULL, quality);
4818 		goto skip_measurement;
4819 	} else
4820 		bytes = (th_ack - tp->gput_seq);
4821 	bytes_ps = (uint64_t)bytes;
4822 	/*
4823 	 * Don't measure a b/w for pacing unless we have gotten at least
4824 	 * an initial windows worth of data in this measurement interval.
4825 	 *
4826 	 * Small numbers of bytes get badly influenced by delayed ack and
4827 	 * other artifacts. Note we take the initial window or our
4828 	 * defined minimum GP (defaulting to 10 which hopefully is the
4829 	 * IW).
4830 	 */
4831 	if (rack->rc_gp_filled == 0) {
4832 		/*
4833 		 * The initial estimate is special. We
4834 		 * have blasted out an IW worth of packets
4835 		 * without a real valid ack ts results. We
4836 		 * then setup the app_limited_needs_set flag,
4837 		 * this should get the first ack in (probably 2
4838 		 * MSS worth) to be recorded as the timestamp.
4839 		 * We thus allow a smaller number of bytes i.e.
4840 		 * IW - 2MSS.
4841 		 */
4842 		reqbytes -= (2 * segsiz);
4843 		/* Also lets fill previous for our first measurement to be neutral */
4844 		rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
4845 	}
4846 	if ((bytes_ps < reqbytes) || rack->app_limited_needs_set) {
4847 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4848 					   rack->r_ctl.rc_app_limited_cnt,
4849 					   0, 0, 10, __LINE__, NULL, quality);
4850 		goto skip_measurement;
4851 	}
4852 	/*
4853 	 * We now need to calculate the Timely like status so
4854 	 * we can update (possibly) the b/w multipliers.
4855 	 */
4856 	new_rtt_diff = (int32_t)rack->r_ctl.rc_gp_srtt - (int32_t)rack->r_ctl.rc_prev_gp_srtt;
4857 	if (rack->rc_gp_filled == 0) {
4858 		/* No previous reading */
4859 		rack->r_ctl.rc_rtt_diff = new_rtt_diff;
4860 	} else {
4861 		if (rack->measure_saw_probe_rtt == 0) {
4862 			/*
4863 			 * We don't want a probertt to be counted
4864 			 * since it will be negative incorrectly. We
4865 			 * expect to be reducing the RTT when we
4866 			 * pace at a slower rate.
4867 			 */
4868 			rack->r_ctl.rc_rtt_diff -= (rack->r_ctl.rc_rtt_diff / 8);
4869 			rack->r_ctl.rc_rtt_diff += (new_rtt_diff / 8);
4870 		}
4871 	}
4872 	timely_says = rack_make_timely_judgement(rack,
4873 	    rack->r_ctl.rc_gp_srtt,
4874 	    rack->r_ctl.rc_rtt_diff,
4875 	    rack->r_ctl.rc_prev_gp_srtt
4876 	);
4877 	bytes_ps *= HPTS_USEC_IN_SEC;
4878 	bytes_ps /= utim;
4879 	if (bytes_ps > rack->r_ctl.last_max_bw) {
4880 		/*
4881 		 * Something is on path playing
4882 		 * since this b/w is not possible based
4883 		 * on our BDP (highest rwnd and lowest rtt
4884 		 * we saw in the measurement window).
4885 		 *
4886 		 * Another option here would be to
4887 		 * instead skip the measurement.
4888 		 */
4889 		rack_log_pacing_delay_calc(rack, bytes, reqbytes,
4890 					   bytes_ps, rack->r_ctl.last_max_bw, 0,
4891 					   11, __LINE__, NULL, quality);
4892 		bytes_ps = rack->r_ctl.last_max_bw;
4893 	}
4894 	/* We store gp for b/w in bytes per second */
4895 	if (rack->rc_gp_filled == 0) {
4896 		/* Initial measurement */
4897 		if (bytes_ps) {
4898 			rack->r_ctl.gp_bw = bytes_ps;
4899 			rack->rc_gp_filled = 1;
4900 			rack->r_ctl.num_measurements = 1;
4901 			rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
4902 		} else {
4903 			rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4904 						   rack->r_ctl.rc_app_limited_cnt,
4905 						   0, 0, 10, __LINE__, NULL, quality);
4906 		}
4907 		if (tcp_in_hpts(rack->rc_tp) &&
4908 		    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
4909 			/*
4910 			 * Ok we can't trust the pacer in this case
4911 			 * where we transition from un-paced to paced.
4912 			 * Or for that matter when the burst mitigation
4913 			 * was making a wild guess and got it wrong.
4914 			 * Stop the pacer and clear up all the aggregate
4915 			 * delays etc.
4916 			 */
4917 			tcp_hpts_remove(rack->rc_tp);
4918 			rack->r_ctl.rc_hpts_flags = 0;
4919 			rack->r_ctl.rc_last_output_to = 0;
4920 		}
4921 		did_add = 2;
4922 	} else if (rack->r_ctl.num_measurements < RACK_REQ_AVG) {
4923 		/* Still a small number run an average */
4924 		rack->r_ctl.gp_bw += bytes_ps;
4925 		addpart = rack->r_ctl.num_measurements;
4926 		rack->r_ctl.num_measurements++;
4927 		if (rack->r_ctl.num_measurements >= RACK_REQ_AVG) {
4928 			/* We have collected enough to move forward */
4929 			rack->r_ctl.gp_bw /= (uint64_t)rack->r_ctl.num_measurements;
4930 		}
4931 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
4932 		did_add = 3;
4933 	} else {
4934 		/*
4935 		 * We want to take 1/wma of the goodput and add in to 7/8th
4936 		 * of the old value weighted by the srtt. So if your measurement
4937 		 * period is say 2 SRTT's long you would get 1/4 as the
4938 		 * value, if it was like 1/2 SRTT then you would get 1/16th.
4939 		 *
4940 		 * But we must be careful not to take too much i.e. if the
4941 		 * srtt is say 20ms and the measurement is taken over
4942 		 * 400ms our weight would be 400/20 i.e. 20. On the
4943 		 * other hand if we get a measurement over 1ms with a
4944 		 * 10ms rtt we only want to take a much smaller portion.
4945 		 */
4946 		if (rack->r_ctl.num_measurements < 0xff) {
4947 			rack->r_ctl.num_measurements++;
4948 		}
4949 		srtt = (uint64_t)tp->t_srtt;
4950 		if (srtt == 0) {
4951 			/*
4952 			 * Strange why did t_srtt go back to zero?
4953 			 */
4954 			if (rack->r_ctl.rc_rack_min_rtt)
4955 				srtt = rack->r_ctl.rc_rack_min_rtt;
4956 			else
4957 				srtt = HPTS_USEC_IN_MSEC;
4958 		}
4959 		/*
4960 		 * XXXrrs: Note for reviewers, in playing with
4961 		 * dynamic pacing I discovered this GP calculation
4962 		 * as done originally leads to some undesired results.
4963 		 * Basically you can get longer measurements contributing
4964 		 * too much to the WMA. Thus I changed it if you are doing
4965 		 * dynamic adjustments to only do the aportioned adjustment
4966 		 * if we have a very small (time wise) measurement. Longer
4967 		 * measurements just get there weight (defaulting to 1/8)
4968 		 * add to the WMA. We may want to think about changing
4969 		 * this to always do that for both sides i.e. dynamic
4970 		 * and non-dynamic... but considering lots of folks
4971 		 * were playing with this I did not want to change the
4972 		 * calculation per.se. without your thoughts.. Lawerence?
4973 		 * Peter??
4974 		 */
4975 		if (rack->rc_gp_dyn_mul == 0) {
4976 			subpart = rack->r_ctl.gp_bw * utim;
4977 			subpart /= (srtt * 8);
4978 			if (subpart < (rack->r_ctl.gp_bw / 2)) {
4979 				/*
4980 				 * The b/w update takes no more
4981 				 * away then 1/2 our running total
4982 				 * so factor it in.
4983 				 */
4984 				addpart = bytes_ps * utim;
4985 				addpart /= (srtt * 8);
4986 			} else {
4987 				/*
4988 				 * Don't allow a single measurement
4989 				 * to account for more than 1/2 of the
4990 				 * WMA. This could happen on a retransmission
4991 				 * where utim becomes huge compared to
4992 				 * srtt (multiple retransmissions when using
4993 				 * the sending rate which factors in all the
4994 				 * transmissions from the first one).
4995 				 */
4996 				subpart = rack->r_ctl.gp_bw / 2;
4997 				addpart = bytes_ps / 2;
4998 			}
4999 			resid_bw = rack->r_ctl.gp_bw - subpart;
5000 			rack->r_ctl.gp_bw = resid_bw + addpart;
5001 			did_add = 1;
5002 		} else {
5003 			if ((utim / srtt) <= 1) {
5004 				/*
5005 				 * The b/w update was over a small period
5006 				 * of time. The idea here is to prevent a small
5007 				 * measurement time period from counting
5008 				 * too much. So we scale it based on the
5009 				 * time so it attributes less than 1/rack_wma_divisor
5010 				 * of its measurement.
5011 				 */
5012 				subpart = rack->r_ctl.gp_bw * utim;
5013 				subpart /= (srtt * rack_wma_divisor);
5014 				addpart = bytes_ps * utim;
5015 				addpart /= (srtt * rack_wma_divisor);
5016 			} else {
5017 				/*
5018 				 * The scaled measurement was long
5019 				 * enough so lets just add in the
5020 				 * portion of the measurement i.e. 1/rack_wma_divisor
5021 				 */
5022 				subpart = rack->r_ctl.gp_bw / rack_wma_divisor;
5023 				addpart = bytes_ps / rack_wma_divisor;
5024 			}
5025 			if ((rack->measure_saw_probe_rtt == 0) ||
5026 		            (bytes_ps > rack->r_ctl.gp_bw)) {
5027 				/*
5028 				 * For probe-rtt we only add it in
5029 				 * if its larger, all others we just
5030 				 * add in.
5031 				 */
5032 				did_add = 1;
5033 				resid_bw = rack->r_ctl.gp_bw - subpart;
5034 				rack->r_ctl.gp_bw = resid_bw + addpart;
5035 			}
5036 		}
5037 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
5038 	}
5039 	if ((rack->gp_ready == 0) &&
5040 	    (rack->r_ctl.num_measurements >= rack->r_ctl.req_measurements)) {
5041 		/* We have enough measurements now */
5042 		rack->gp_ready = 1;
5043 		if ((rack->rc_always_pace && (rack->use_fixed_rate == 0)) ||
5044 		    rack->rack_hibeta)
5045 			rack_set_cc_pacing(rack);
5046 		if (rack->defer_options)
5047 			rack_apply_deferred_options(rack);
5048 	}
5049 	rack_log_pacing_delay_calc(rack, subpart, addpart, bytes_ps, stim,
5050 				   rack_get_bw(rack), 22, did_add, NULL, quality);
5051 	/* We do not update any multipliers if we are in or have seen a probe-rtt */
5052 	if ((rack->measure_saw_probe_rtt == 0) && rack->rc_gp_rtt_set)
5053 		rack_update_multiplier(rack, timely_says, bytes_ps,
5054 				       rack->r_ctl.rc_gp_srtt,
5055 				       rack->r_ctl.rc_rtt_diff);
5056 	rack_log_pacing_delay_calc(rack, bytes, tim, bytes_ps, stim,
5057 				   rack_get_bw(rack), 3, line, NULL, quality);
5058 	rack_log_pacing_delay_calc(rack,
5059 				   bytes, /* flex2 */
5060 				   tim, /* flex1 */
5061 				   bytes_ps, /* bw_inuse */
5062 				   rack->r_ctl.gp_bw, /* delRate */
5063 				   rack_get_lt_bw(rack), /* rttProp */
5064 				   20, line, NULL, 0);
5065 	/* reset the gp srtt and setup the new prev */
5066 	rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
5067 	/* Record the lost count for the next measurement */
5068 	rack->r_ctl.rc_loss_at_start = rack->r_ctl.rc_loss_count;
5069 skip_measurement:
5070 	/*
5071 	 * We restart our diffs based on the gpsrtt in the
5072 	 * measurement window.
5073 	 */
5074 	rack->rc_gp_rtt_set = 0;
5075 	rack->rc_gp_saw_rec = 0;
5076 	rack->rc_gp_saw_ca = 0;
5077 	rack->rc_gp_saw_ss = 0;
5078 	rack->rc_dragged_bottom = 0;
5079 
5080 	if (quality == RACK_QUALITY_HIGH) {
5081 		/*
5082 		 * Gput in the stats world is in kbps where bytes_ps is
5083 		 * bytes per second so we do ((x * 8)/ 1000).
5084 		 */
5085 		gput = (int32_t)((bytes_ps << 3) / (uint64_t)1000);
5086 #ifdef STATS
5087 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_GPUT,
5088 					 gput);
5089 		/*
5090 		 * XXXLAS: This is a temporary hack, and should be
5091 		 * chained off VOI_TCP_GPUT when stats(9) grows an
5092 		 * API to deal with chained VOIs.
5093 		 */
5094 		if (tp->t_stats_gput_prev > 0)
5095 			stats_voi_update_abs_s32(tp->t_stats,
5096 						 VOI_TCP_GPUT_ND,
5097 						 ((gput - tp->t_stats_gput_prev) * 100) /
5098 						 tp->t_stats_gput_prev);
5099 #endif
5100 		tp->t_stats_gput_prev = gput;
5101 	}
5102 	tp->t_flags &= ~TF_GPUTINPROG;
5103 	/*
5104 	 * Now are we app limited now and there is space from where we
5105 	 * were to where we want to go?
5106 	 *
5107 	 * We don't do the other case i.e. non-applimited here since
5108 	 * the next send will trigger us picking up the missing data.
5109 	 */
5110 	if (rack->r_ctl.rc_first_appl &&
5111 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
5112 	    rack->r_ctl.rc_app_limited_cnt &&
5113 	    (SEQ_GT(rack->r_ctl.rc_first_appl->r_start, th_ack)) &&
5114 	    ((rack->r_ctl.rc_first_appl->r_end - th_ack) >
5115 	     max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
5116 		/*
5117 		 * Yep there is enough outstanding to make a measurement here.
5118 		 */
5119 		struct rack_sendmap *rsm;
5120 
5121 		rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
5122 		rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
5123 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
5124 		rack->app_limited_needs_set = 0;
5125 		tp->gput_seq = th_ack;
5126 		if (rack->in_probe_rtt)
5127 			rack->measure_saw_probe_rtt = 1;
5128 		else if ((rack->measure_saw_probe_rtt) &&
5129 			 (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
5130 			rack->measure_saw_probe_rtt = 0;
5131 		if ((rack->r_ctl.rc_first_appl->r_end - th_ack) >= rack_get_measure_window(tp, rack)) {
5132 			/* There is a full window to gain info from */
5133 			tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
5134 		} else {
5135 			/* We can only measure up to the applimited point */
5136 			tp->gput_ack = tp->gput_seq + (rack->r_ctl.rc_first_appl->r_end - th_ack);
5137 			if ((tp->gput_ack - tp->gput_seq) < (MIN_GP_WIN * segsiz)) {
5138 				/*
5139 				 * We don't have enough to make a measurement.
5140 				 */
5141 				tp->t_flags &= ~TF_GPUTINPROG;
5142 				rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
5143 							   0, 0, 0, 6, __LINE__, NULL, quality);
5144 				return;
5145 			}
5146 		}
5147 		if (tp->t_state >= TCPS_FIN_WAIT_1) {
5148 			/*
5149 			 * We will get no more data into the SB
5150 			 * this means we need to have the data available
5151 			 * before we start a measurement.
5152 			 */
5153 			if (sbavail(&tptosocket(tp)->so_snd) < (tp->gput_ack - tp->gput_seq)) {
5154 				/* Nope not enough data. */
5155 				return;
5156 			}
5157 		}
5158 		tp->t_flags |= TF_GPUTINPROG;
5159 		/*
5160 		 * Now we need to find the timestamp of the send at tp->gput_seq
5161 		 * for the send based measurement.
5162 		 */
5163 		rack->r_ctl.rc_gp_cumack_ts = 0;
5164 		rsm = tqhash_find(rack->r_ctl.tqh, tp->gput_seq);
5165 		if (rsm) {
5166 			/* Ok send-based limit is set */
5167 			if (SEQ_LT(rsm->r_start, tp->gput_seq)) {
5168 				/*
5169 				 * Move back to include the earlier part
5170 				 * so our ack time lines up right (this may
5171 				 * make an overlapping measurement but thats
5172 				 * ok).
5173 				 */
5174 				tp->gput_seq = rsm->r_start;
5175 			}
5176 			if (rsm->r_flags & RACK_ACKED) {
5177 				struct rack_sendmap *nrsm;
5178 
5179 				tp->gput_ts = (uint32_t)rsm->r_ack_arrival;
5180 				tp->gput_seq = rsm->r_end;
5181 				nrsm = tqhash_next(rack->r_ctl.tqh, rsm);
5182 				if (nrsm)
5183 					rsm = nrsm;
5184 				else {
5185 					rack->app_limited_needs_set = 1;
5186 				}
5187 			} else
5188 				rack->app_limited_needs_set = 1;
5189 			/* We always go from the first send */
5190 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[0];
5191 		} else {
5192 			/*
5193 			 * If we don't find the rsm due to some
5194 			 * send-limit set the current time, which
5195 			 * basically disables the send-limit.
5196 			 */
5197 			struct timeval tv;
5198 
5199 			microuptime(&tv);
5200 			rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
5201 		}
5202 		rack_tend_gp_marks(tp, rack);
5203 		rack_log_pacing_delay_calc(rack,
5204 					   tp->gput_seq,
5205 					   tp->gput_ack,
5206 					   (uint64_t)rsm,
5207 					   tp->gput_ts,
5208 					   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) | (uint64_t)rack->r_ctl.rc_gp_output_ts),
5209 					   9,
5210 					   __LINE__, rsm, quality);
5211 		rack_log_gpset(rack, tp->gput_ack, 0, 0, __LINE__, 1, NULL);
5212 	} else {
5213 		/*
5214 		 * To make sure proper timestamp merging occurs, we need to clear
5215 		 * all GP marks if we don't start a measurement.
5216 		 */
5217 		rack_clear_gp_marks(tp, rack);
5218 	}
5219 }
5220 
5221 /*
5222  * CC wrapper hook functions
5223  */
5224 static void
5225 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack, uint32_t th_ack, uint16_t nsegs,
5226     uint16_t type, int32_t recovery)
5227 {
5228 	uint32_t prior_cwnd, acked;
5229 	struct tcp_log_buffer *lgb = NULL;
5230 	uint8_t labc_to_use, quality;
5231 
5232 	INP_WLOCK_ASSERT(tptoinpcb(tp));
5233 	tp->t_ccv.nsegs = nsegs;
5234 	acked = tp->t_ccv.bytes_this_ack = (th_ack - tp->snd_una);
5235 	if ((recovery) && (rack->r_ctl.rc_early_recovery_segs)) {
5236 		uint32_t max;
5237 
5238 		max = rack->r_ctl.rc_early_recovery_segs * ctf_fixed_maxseg(tp);
5239 		if (tp->t_ccv.bytes_this_ack > max) {
5240 			tp->t_ccv.bytes_this_ack = max;
5241 		}
5242 	}
5243 #ifdef STATS
5244 	stats_voi_update_abs_s32(tp->t_stats, VOI_TCP_CALCFRWINDIFF,
5245 	    ((int32_t)rack->r_ctl.cwnd_to_use) - tp->snd_wnd);
5246 #endif
5247 	if ((th_ack == tp->snd_max) && rack->lt_bw_up) {
5248 		/* We will ack all, time
5249 		 * to end any lt_bw_up we
5250 		 * have running until something
5251 		 * new is sent.
5252 		 */
5253 		struct timeval tv;
5254 
5255 		rack->r_ctl.lt_bw_bytes += (tp->snd_max - rack->r_ctl.lt_seq);
5256 		rack->r_ctl.lt_seq = tp->snd_max;
5257 		(void)tcp_get_usecs(&tv);
5258 		rack->r_ctl.lt_bw_time += (tcp_tv_to_lusectick(&tv) - rack->r_ctl.lt_timemark);
5259 		rack->lt_bw_up = 0;
5260 	}
5261 	quality = RACK_QUALITY_NONE;
5262 	if ((tp->t_flags & TF_GPUTINPROG) &&
5263 	    rack_enough_for_measurement(tp, rack, th_ack, &quality)) {
5264 		/* Measure the Goodput */
5265 		rack_do_goodput_measurement(tp, rack, th_ack, __LINE__, quality);
5266 	}
5267 	/* Which way our we limited, if not cwnd limited no advance in CA */
5268 	if (tp->snd_cwnd <= tp->snd_wnd)
5269 		tp->t_ccv.flags |= CCF_CWND_LIMITED;
5270 	else
5271 		tp->t_ccv.flags &= ~CCF_CWND_LIMITED;
5272 	if (tp->snd_cwnd > tp->snd_ssthresh) {
5273 		tp->t_bytes_acked += min(tp->t_ccv.bytes_this_ack,
5274 			 nsegs * V_tcp_abc_l_var * ctf_fixed_maxseg(tp));
5275 		/* For the setting of a window past use the actual scwnd we are using */
5276 		if (tp->t_bytes_acked >= rack->r_ctl.cwnd_to_use) {
5277 			tp->t_bytes_acked -= rack->r_ctl.cwnd_to_use;
5278 			tp->t_ccv.flags |= CCF_ABC_SENTAWND;
5279 		}
5280 	} else {
5281 		tp->t_ccv.flags &= ~CCF_ABC_SENTAWND;
5282 		tp->t_bytes_acked = 0;
5283 	}
5284 	prior_cwnd = tp->snd_cwnd;
5285 	if ((recovery == 0) || (rack_max_abc_post_recovery == 0) || rack->r_use_labc_for_rec ||
5286 	    (rack_client_low_buf && rack->client_bufferlvl &&
5287 	    (rack->client_bufferlvl < rack_client_low_buf)))
5288 		labc_to_use = rack->rc_labc;
5289 	else
5290 		labc_to_use = rack_max_abc_post_recovery;
5291 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
5292 		union tcp_log_stackspecific log;
5293 		struct timeval tv;
5294 
5295 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5296 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5297 		log.u_bbr.flex1 = th_ack;
5298 		log.u_bbr.flex2 = tp->t_ccv.flags;
5299 		log.u_bbr.flex3 = tp->t_ccv.bytes_this_ack;
5300 		log.u_bbr.flex4 = tp->t_ccv.nsegs;
5301 		log.u_bbr.flex5 = labc_to_use;
5302 		log.u_bbr.flex6 = prior_cwnd;
5303 		log.u_bbr.flex7 = V_tcp_do_newsack;
5304 		log.u_bbr.flex8 = 1;
5305 		lgb = tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
5306 				     0, &log, false, NULL, __func__, __LINE__,&tv);
5307 	}
5308 	if (CC_ALGO(tp)->ack_received != NULL) {
5309 		/* XXXLAS: Find a way to live without this */
5310 		tp->t_ccv.curack = th_ack;
5311 		tp->t_ccv.labc = labc_to_use;
5312 		tp->t_ccv.flags |= CCF_USE_LOCAL_ABC;
5313 		CC_ALGO(tp)->ack_received(&tp->t_ccv, type);
5314 	}
5315 	if (lgb) {
5316 		lgb->tlb_stackinfo.u_bbr.flex6 = tp->snd_cwnd;
5317 	}
5318 	if (rack->r_must_retran) {
5319 		if (SEQ_GEQ(th_ack, rack->r_ctl.rc_snd_max_at_rto)) {
5320 			/*
5321 			 * We now are beyond the rxt point so lets disable
5322 			 * the flag.
5323 			 */
5324 			rack->r_ctl.rc_out_at_rto = 0;
5325 			rack->r_must_retran = 0;
5326 		} else if ((prior_cwnd + ctf_fixed_maxseg(tp)) <= tp->snd_cwnd) {
5327 			/*
5328 			 * Only decrement the rc_out_at_rto if the cwnd advances
5329 			 * at least a whole segment. Otherwise next time the peer
5330 			 * acks, we won't be able to send this generaly happens
5331 			 * when we are in Congestion Avoidance.
5332 			 */
5333 			if (acked <= rack->r_ctl.rc_out_at_rto){
5334 				rack->r_ctl.rc_out_at_rto -= acked;
5335 			} else {
5336 				rack->r_ctl.rc_out_at_rto = 0;
5337 			}
5338 		}
5339 	}
5340 #ifdef STATS
5341 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_LCWIN, rack->r_ctl.cwnd_to_use);
5342 #endif
5343 	if (rack->r_ctl.rc_rack_largest_cwnd < rack->r_ctl.cwnd_to_use) {
5344 		rack->r_ctl.rc_rack_largest_cwnd = rack->r_ctl.cwnd_to_use;
5345 	}
5346 }
5347 
5348 static void
5349 tcp_rack_partialack(struct tcpcb *tp)
5350 {
5351 	struct tcp_rack *rack;
5352 
5353 	rack = (struct tcp_rack *)tp->t_fb_ptr;
5354 	INP_WLOCK_ASSERT(tptoinpcb(tp));
5355 	/*
5356 	 * If we are doing PRR and have enough
5357 	 * room to send <or> we are pacing and prr
5358 	 * is disabled we will want to see if we
5359 	 * can send data (by setting r_wanted_output to
5360 	 * true).
5361 	 */
5362 	if ((rack->r_ctl.rc_prr_sndcnt > 0) ||
5363 	    rack->rack_no_prr)
5364 		rack->r_wanted_output = 1;
5365 }
5366 
5367 static inline void
5368 rack_set_most_aggr(struct tcp_rack *rack)
5369 {
5370 	rack->r_fill_less_agg = 0;
5371 	/* Once the cwnd as been clamped we don't do fill_cw */
5372 	if (rack->r_cwnd_was_clamped == 0)
5373 		rack->rc_pace_to_cwnd = 1;
5374 	rack->r_pacing_discount = 0;
5375 }
5376 
5377 static inline void
5378 rack_limit_fillcw(struct tcp_rack *rack)
5379 {
5380 	rack->r_fill_less_agg = 1;
5381 	/* Once the cwnd as been clamped we don't do fill_cw */
5382 	if (rack->r_cwnd_was_clamped == 0)
5383 		rack->rc_pace_to_cwnd = 1;
5384 	rack->r_pacing_discount = 0;
5385 }
5386 
5387 static inline void
5388 rack_disable_fillcw(struct tcp_rack *rack)
5389 {
5390 	rack->r_fill_less_agg = 1;
5391 	rack->rc_pace_to_cwnd = 0;
5392 	rack->r_pacing_discount = 0;
5393 }
5394 
5395 static void
5396 rack_client_buffer_level_set(struct tcp_rack *rack)
5397 {
5398 	/*
5399 	 * Only if DGP is on do we do anything that
5400 	 * changes stack behavior. If DGP is off all
5401 	 * we will do is issue a BB log (if BB logging is
5402 	 * on) and return.
5403 	 */
5404 	if (rack->dgp_on == 0) {
5405 		rack_log_pacing_delay_calc(rack, 0, rack->client_bufferlvl,
5406 					   0, 0, 0, 30, __LINE__, NULL, 0);
5407 		return;
5408 	}
5409 	if (IN_RECOVERY(rack->rc_tp->t_flags) && rack->r_ctl.full_dgp_in_rec) {
5410 		goto set_most_agg;
5411 	}
5412 	/*
5413 	 * We are in DGP so what setting should we
5414 	 * apply based on where the client is?
5415 	 */
5416 	switch(rack->r_ctl.rc_dgp_bl_agg) {
5417 	default:
5418 	case DGP_LEVEL0:
5419 set_most_agg:
5420 		rack_set_most_aggr(rack);
5421 		break;
5422 	case DGP_LEVEL1:
5423 		if (rack->client_bufferlvl == 4)
5424 			rack_limit_fillcw(rack);
5425 		else if (rack->client_bufferlvl == 5)
5426 			rack_disable_fillcw(rack);
5427 		else
5428 			rack_set_most_aggr(rack);
5429 		break;
5430 	case DGP_LEVEL2:
5431 		if (rack->client_bufferlvl == 3)
5432 			rack_limit_fillcw(rack);
5433 		else if (rack->client_bufferlvl == 4)
5434 			rack_disable_fillcw(rack);
5435 		else if (rack->client_bufferlvl == 5) {
5436 			rack_disable_fillcw(rack);
5437 			rack->r_pacing_discount = 1;
5438 			rack->r_ctl.pacing_discount_amm = 1;
5439 		} else
5440 			rack_set_most_aggr(rack);
5441 		break;
5442 	case DGP_LEVEL3:
5443 		if (rack->client_bufferlvl == 2)
5444 			rack_limit_fillcw(rack);
5445 		else if (rack->client_bufferlvl == 3)
5446 			rack_disable_fillcw(rack);
5447 		else if (rack->client_bufferlvl == 4) {
5448 			rack_disable_fillcw(rack);
5449 			rack->r_pacing_discount = 1;
5450 			rack->r_ctl.pacing_discount_amm = 1;
5451 		} else if (rack->client_bufferlvl == 5) {
5452 			rack_disable_fillcw(rack);
5453 			rack->r_pacing_discount = 1;
5454 			rack->r_ctl.pacing_discount_amm = 2;
5455 		} else
5456 			rack_set_most_aggr(rack);
5457 		break;
5458 	}
5459 	rack_log_pacing_delay_calc(rack, rack->r_ctl.rc_dgp_bl_agg, rack->client_bufferlvl, 0,
5460 				   0, 0, 30, __LINE__, NULL, 0);
5461 }
5462 
5463 static void
5464 do_rack_check_for_unclamp(struct tcpcb *tp, struct tcp_rack *rack)
5465 {
5466 	/*
5467 	 * Can we unclamp. We unclamp if more than
5468 	 * N rounds have transpired with no loss.
5469 	 */
5470 	uint64_t snds, rxts, rxt_per;
5471 	uint32_t rnds;
5472 
5473 	rnds = rack->r_ctl.current_round - rack->r_ctl.last_rnd_rxt_clamped;
5474 	if ((rack_unclamp_round_thresh > 0) &&
5475 	    (rnds >= rack_unclamp_round_thresh)) {
5476 		snds = tp->t_sndbytes - rack->r_ctl.last_sndbytes;
5477 		KASSERT ((snds > 0), ("rack:%p tp:%p snds:%ju is 0", rack, tp,
5478 		    (uintmax_t)snds));
5479 		rxts = tp->t_snd_rxt_bytes - rack->r_ctl.last_snd_rxt_bytes;
5480 		rxt_per = rxts * 1000;
5481 		rxt_per /= snds;
5482 		if ((uint32_t)rxt_per <= rack_unclamp_rxt_thresh) {
5483 			/* Unclamp */
5484 			if (tcp_bblogging_on(rack->rc_tp)) {
5485 				union tcp_log_stackspecific log;
5486 				struct timeval tv;
5487 
5488 				memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5489 				log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5490 				log.u_bbr.flex3 = rnds;
5491 				log.u_bbr.flex4 = rack_unclamp_round_thresh;
5492 				log.u_bbr.flex5 = (uint32_t)rxt_per;
5493 				log.u_bbr.flex8 = 6;
5494 				log.u_bbr.pkt_epoch = rack->r_ctl.rc_pace_max_segs;
5495 				log.u_bbr.bbr_state = rack->rc_pace_to_cwnd;
5496 				log.u_bbr.delivered = rack->r_ctl.num_of_clamps_applied;
5497 				log.u_bbr.applimited = rack->r_ctl.max_clamps;
5498 				log.u_bbr.epoch = rack->r_ctl.clamp_options;
5499 				log.u_bbr.cur_del_rate = rxts;
5500 				log.u_bbr.bw_inuse = rack_get_lt_bw(rack);
5501 				log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
5502 				log.u_bbr.lt_epoch = (uint32_t)((rack->r_ctl.gp_bw >> 32) & 0x00000000ffffffff);
5503 				log.u_bbr.pkts_out = (uint32_t)(rack->r_ctl.gp_bw & 0x00000000ffffffff);
5504 				tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
5505 					      0, &log, false, NULL, NULL, 0, &tv);
5506 			}
5507 			rack->r_ctl.num_of_clamps_applied = 0;
5508 			rack->r_cwnd_was_clamped = 0;
5509 			rack->excess_rxt_on = 1;
5510 			if (rack->r_ctl.clamp_options) {
5511 				/*
5512 				 * We only allow fillcw to be toggled
5513 				 * if you are setting a max seg too.
5514 				 */
5515 				if (rack->r_ctl.clamp_options & 0x1) {
5516 					if ((rack->rc_pace_to_cwnd == 0) && (rack->dgp_on == 0)) {
5517 						/* turn on fill cw  for non-dgp*/
5518 						rack->rc_pace_to_cwnd = 0;
5519 					} else if ((rack->dgp_on == 1) && (rack->rc_pace_to_cwnd == 1)) {
5520 						/* For DGP we want it off */
5521 						rack->rc_pace_to_cwnd = 1;
5522 					}
5523 				}
5524 			}
5525 			if (rack->dgp_on) {
5526 				/* Reset all multipliers to 100.0 so just the measured bw */
5527 				/* Crash any per boosts down to 100% */
5528 				rack->r_ctl.rack_per_of_gp_rec = 100;
5529 				rack->r_ctl.rack_per_of_gp_ss = 100;
5530 				rack->r_ctl.rack_per_of_gp_ca = 100;
5531 				/* Set in an upper bound for ss/ca % increase */
5532 				rack->r_ctl.rack_per_upper_bound_ss = (uint8_t)rack_per_upper_bound_ss;
5533 				rack->r_ctl.rack_per_upper_bound_ca = (uint8_t)rack_per_upper_bound_ca;
5534 			}
5535 		}
5536 	}
5537 }
5538 
5539 static void
5540 do_rack_excess_rxt(struct tcpcb *tp, struct tcp_rack *rack)
5541 {
5542 	/*
5543 	 * Rack excess rxt accounting is turned on. If we
5544 	 * are above a threshold of rxt's in at least N
5545 	 * rounds, then back off the cwnd and ssthresh
5546 	 * to fit into the long-term b/w.
5547 	 */
5548 	uint64_t snds, rxts, rxt_per, lt_bw, bdp;
5549 	uint32_t rnds, new_cwnd, new_ssthresh, rtt, shared_cwnd_was_enabled = 0;
5550 
5551 	/* Is it shut off by 0 rounds? */
5552 	if (rack_rxt_min_rnds == 0)
5553 		return;
5554 	if ((rack->r_ctl.max_clamps > 0) &&
5555 	    (rack->r_ctl.num_of_clamps_applied >= rack->r_ctl.max_clamps)) {
5556 		/*
5557 		 * The idea, if max_clamps is set, is that if clamping it
5558 		 * N times did not work again, then there is no sense
5559 		 * clamping it again. The link is just a lossy link and
5560 		 * our clamps are doing no good. Turn it off so we don't come
5561 		 * back here again.
5562 		 */
5563 		rack->excess_rxt_on = 0;
5564 		rack->r_cwnd_was_clamped = 0;
5565 		rack->r_ctl.num_of_clamps_applied = 0;
5566 		return;
5567 	}
5568 	snds = tp->t_sndbytes - rack->r_ctl.last_sndbytes;
5569 	rxts = tp->t_snd_rxt_bytes - rack->r_ctl.last_snd_rxt_bytes;
5570 	rnds = rack->r_ctl.current_round - rack->r_ctl.last_rnd_rxt_clamped;
5571 	/* Has enough rounds progressed for us to re-measure? */
5572 	if ((rnds >= rack_rxt_min_rnds) &&
5573 	    (rack->r_ctl.rxt_threshold > 0)){
5574 		rxt_per = rxts * 1000;
5575 		rxt_per /= snds;
5576 		if (rxt_per >= rack->r_ctl.rxt_threshold) {
5577 			/*
5578 			 * Action required:
5579 			 *  We are above our excess retransmit level, lets
5580 			 *  cut down the cwnd and ssthresh to match the long-term
5581 			 *  b/w we are getting.
5582 			 */
5583 			/* First disable scwnd if enabled */
5584 #ifdef NETFLIX_SHARED_CWND
5585 			rack->rack_enable_scwnd = 0;
5586 			if (rack->r_ctl.rc_scw) {
5587 				uint32_t limit;
5588 
5589 				shared_cwnd_was_enabled = 1;
5590 				if (rack->r_limit_scw)
5591 					limit = max(1, rack->r_ctl.rc_lowest_us_rtt);
5592 				else
5593 					limit = 0;
5594 				tcp_shared_cwnd_free_full(tp, rack->r_ctl.rc_scw,
5595 							  rack->r_ctl.rc_scw_index,
5596 							  limit);
5597 				rack->r_ctl.rc_scw = NULL;
5598 			}
5599 
5600 #endif
5601 			/* Calculate what the cwnd and ssthresh should be */
5602 			tcp_trace_point(rack->rc_tp, TCP_TP_EXCESS_RXT);
5603 			lt_bw = rack_get_lt_bw(rack);
5604 			if (lt_bw == 0) {
5605 				/*
5606 				 * No lt_bw, lets chop things to one MSS
5607 				 * and the ssthresh to the iwnd.
5608 				 */
5609 reset_to_iw:
5610 				new_cwnd = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
5611 				new_ssthresh = tcp_compute_initwnd(tcp_maxseg(tp));
5612 			} else {
5613 				rtt = rack->rc_rack_rtt;
5614 				if (rtt == 0) {
5615 					/* If we have no rack_rtt drop to the IW situation */
5616 					goto reset_to_iw;
5617 				}
5618 				bdp = lt_bw * (uint64_t)rtt;
5619 				bdp /= HPTS_USEC_IN_SEC;
5620 				new_cwnd = (uint32_t)bdp;
5621 				new_ssthresh = new_cwnd - 1;
5622 				if (new_cwnd < ctf_fixed_maxseg(tp)) {
5623 					/* Rock bottom, goto IW settings  */
5624 					goto reset_to_iw;
5625 				}
5626 			}
5627 			rack->r_cwnd_was_clamped = 1;
5628 			rack->r_ctl.num_of_clamps_applied++;
5629 			/* Reset the counter fromn now */
5630 			tp->t_bytes_acked = 0;
5631 			/*
5632 			 * Now what about options?
5633 			 * We look at the bottom  8 bits:
5634 			 * F = fill cw bit (toggle it if set)
5635 			 * S = Segment bits
5636 			 * M = set max segment bit
5637 			 *
5638 			 * SSSS SSMF
5639 			 */
5640 			if (rack->r_ctl.clamp_options) {
5641 				if (rack->r_ctl.clamp_options & 0x1) {
5642 					if ((rack->rc_pace_to_cwnd == 0) && (rack->dgp_on == 0)) {
5643 						/* turn on fill cw  for non-dgp*/
5644 						rack->rc_pace_to_cwnd = 1;
5645 					} else if ((rack->dgp_on == 1) && (rack->rc_pace_to_cwnd == 1)) {
5646 						/* For DGP we want it off */
5647 						rack->rc_pace_to_cwnd = 0;
5648 					}
5649 				}
5650 			}
5651 			if (rack->dgp_on) {
5652 				/* Reset all multipliers to 100.0 so just the measured bw */
5653 				/* Crash any per boosts down to 100% */
5654 				rack->r_ctl.rack_per_of_gp_rec = 100;
5655 				rack->r_ctl.rack_per_of_gp_ss = 100;
5656 				rack->r_ctl.rack_per_of_gp_ca = 100;
5657 				/* Set in an upper bound for ss/ca % increase */
5658 				rack->r_ctl.rack_per_upper_bound_ss = (uint8_t)rack_clamp_ss_upper;
5659 				rack->r_ctl.rack_per_upper_bound_ca = (uint8_t)rack_clamp_ca_upper;
5660 				/* Now move to the lt_bw */
5661 				rack->r_ctl.gp_bw = lt_bw;
5662 				rack->rc_gp_filled = 1;
5663 				rack->r_ctl.num_measurements = RACK_REQ_AVG;
5664 			}
5665 			if (tcp_bblogging_on(rack->rc_tp)) {
5666 				union tcp_log_stackspecific log;
5667 				struct timeval tv;
5668 
5669 				memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5670 				log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5671 				log.u_bbr.flex1 = new_cwnd;
5672 				log.u_bbr.flex2 = new_ssthresh;
5673 				log.u_bbr.flex3 = rnds;
5674 				log.u_bbr.flex4 = rack_rxt_min_rnds;
5675 				log.u_bbr.flex5 = rtt;
5676 				log.u_bbr.flex6 = shared_cwnd_was_enabled;
5677 				log.u_bbr.flex8 = 5;
5678 				log.u_bbr.pkt_epoch = rack->r_ctl.rc_pace_max_segs;
5679 				log.u_bbr.bbr_state = rack->rc_pace_to_cwnd;
5680 				log.u_bbr.delivered = rack->r_ctl.num_of_clamps_applied;
5681 				log.u_bbr.applimited = rack->r_ctl.max_clamps;
5682 				log.u_bbr.epoch = rack->r_ctl.clamp_options;
5683 				log.u_bbr.cur_del_rate = rxts;
5684 				log.u_bbr.delRate = snds;
5685 				log.u_bbr.rttProp = rack->r_ctl.rxt_threshold;
5686 				log.u_bbr.bw_inuse = lt_bw;
5687 				log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
5688 				log.u_bbr.lt_epoch = (uint32_t)((rack->r_ctl.gp_bw >> 32) & 0x00000000ffffffff);
5689 				log.u_bbr.pkts_out = (uint32_t)(rack->r_ctl.gp_bw & 0x00000000ffffffff);
5690 				tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
5691 					       0, &log, false, NULL, NULL, 0, &tv);
5692 			}
5693 			/* Update our point where we did it */
5694 			if (rack->r_ctl.already_had_a_excess == 0) {
5695 				rack->r_ctl.already_had_a_excess = 1;
5696 				counter_u64_add(rack_rxt_clamps_cwnd_uniq, 1);
5697 			}
5698 			counter_u64_add(rack_rxt_clamps_cwnd, 1);
5699 			rack->r_ctl.last_sndbytes = tp->t_sndbytes;
5700 			rack->r_ctl.last_snd_rxt_bytes = tp->t_snd_rxt_bytes;
5701 			rack->r_ctl.last_rnd_rxt_clamped = rack->r_ctl.current_round;
5702 			if (new_cwnd < tp->snd_cwnd)
5703 				tp->snd_cwnd = new_cwnd;
5704 			if (new_ssthresh < tp->snd_ssthresh)
5705 				tp->snd_ssthresh = new_ssthresh;
5706 		}
5707 	}
5708 }
5709 
5710 static void
5711 rack_post_recovery(struct tcpcb *tp, uint32_t th_ack)
5712 {
5713 	struct tcp_rack *rack;
5714 	uint32_t orig_cwnd;
5715 
5716 	orig_cwnd = tp->snd_cwnd;
5717 	INP_WLOCK_ASSERT(tptoinpcb(tp));
5718 	rack = (struct tcp_rack *)tp->t_fb_ptr;
5719 	/* only alert CC if we alerted when we entered */
5720 	if (CC_ALGO(tp)->post_recovery != NULL) {
5721 		tp->t_ccv.curack = th_ack;
5722 		CC_ALGO(tp)->post_recovery(&tp->t_ccv);
5723 		if (tp->snd_cwnd < tp->snd_ssthresh) {
5724 			/*
5725 			 * Rack has burst control and pacing
5726 			 * so lets not set this any lower than
5727 			 * snd_ssthresh per RFC-6582 (option 2).
5728 			 */
5729 			tp->snd_cwnd = tp->snd_ssthresh;
5730 		}
5731 	}
5732 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
5733 		union tcp_log_stackspecific log;
5734 		struct timeval tv;
5735 
5736 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5737 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5738 		log.u_bbr.flex1 = th_ack;
5739 		log.u_bbr.flex2 = tp->t_ccv.flags;
5740 		log.u_bbr.flex3 = tp->t_ccv.bytes_this_ack;
5741 		log.u_bbr.flex4 = tp->t_ccv.nsegs;
5742 		log.u_bbr.flex5 = V_tcp_abc_l_var;
5743 		log.u_bbr.flex6 = orig_cwnd;
5744 		log.u_bbr.flex7 = V_tcp_do_newsack;
5745 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
5746 		log.u_bbr.flex8 = 2;
5747 		tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
5748 			       0, &log, false, NULL, __func__, __LINE__, &tv);
5749 	}
5750 	if ((rack->rack_no_prr == 0) &&
5751 	    (rack->no_prr_addback == 0) &&
5752 	    (rack->r_ctl.rc_prr_sndcnt > 0)) {
5753 		/*
5754 		 * Suck the next prr cnt back into cwnd, but
5755 		 * only do that if we are not application limited.
5756 		 */
5757 		if (ctf_outstanding(tp) <= sbavail(&tptosocket(tp)->so_snd)) {
5758 			/*
5759 			 * We are allowed to add back to the cwnd the amount we did
5760 			 * not get out if:
5761 			 * a) no_prr_addback is off.
5762 			 * b) we are not app limited
5763 			 * c) we are doing prr
5764 			 * <and>
5765 			 * d) it is bounded by rack_prr_addbackmax (if addback is 0, then none).
5766 			 */
5767 			tp->snd_cwnd += min((ctf_fixed_maxseg(tp) * rack_prr_addbackmax),
5768 					    rack->r_ctl.rc_prr_sndcnt);
5769 		}
5770 		rack->r_ctl.rc_prr_sndcnt = 0;
5771 		rack_log_to_prr(rack, 1, 0, __LINE__);
5772 	}
5773 	rack_log_to_prr(rack, 14, orig_cwnd, __LINE__);
5774 	tp->snd_recover = tp->snd_una;
5775 	if (rack->r_ctl.dsack_persist) {
5776 		rack->r_ctl.dsack_persist--;
5777 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
5778 			rack->r_ctl.num_dsack = 0;
5779 		}
5780 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
5781 	}
5782 	EXIT_RECOVERY(tp->t_flags);
5783 	if (rack->r_ctl.full_dgp_in_rec)
5784 		rack_client_buffer_level_set(rack);
5785 }
5786 
5787 static void
5788 rack_cong_signal(struct tcpcb *tp, uint32_t type, uint32_t ack, int line)
5789 {
5790 	struct tcp_rack *rack;
5791 	uint32_t ssthresh_enter, cwnd_enter, in_rec_at_entry, orig_cwnd;
5792 
5793 	INP_WLOCK_ASSERT(tptoinpcb(tp));
5794 #ifdef STATS
5795 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_CSIG, type);
5796 #endif
5797 	if (IN_RECOVERY(tp->t_flags) == 0) {
5798 		in_rec_at_entry = 0;
5799 		ssthresh_enter = tp->snd_ssthresh;
5800 		cwnd_enter = tp->snd_cwnd;
5801 	} else
5802 		in_rec_at_entry = 1;
5803 	rack = (struct tcp_rack *)tp->t_fb_ptr;
5804 	switch (type) {
5805 	case CC_NDUPACK:
5806 		tp->t_flags &= ~TF_WASFRECOVERY;
5807 		tp->t_flags &= ~TF_WASCRECOVERY;
5808 		if (!IN_FASTRECOVERY(tp->t_flags)) {
5809 			if (rack->dgp_on && rack->r_cwnd_was_clamped) {
5810 				/* Reset the gains so that on exit we will be softer longer */
5811 				rack->r_ctl.rack_per_of_gp_rec = 100;
5812 				rack->r_ctl.rack_per_of_gp_ss = 98;
5813 				rack->r_ctl.rack_per_of_gp_ca = 98;
5814 			}
5815 			rack->r_ctl.rc_prr_delivered = 0;
5816 			rack->r_ctl.rc_prr_out = 0;
5817 			rack->r_fast_output = 0;
5818 			if (rack->rack_no_prr == 0) {
5819 				rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
5820 				rack_log_to_prr(rack, 2, in_rec_at_entry, line);
5821 			}
5822 			rack->r_ctl.rc_prr_recovery_fs = tp->snd_max - tp->snd_una;
5823 			tp->snd_recover = tp->snd_max;
5824 			if (tp->t_flags2 & TF2_ECN_PERMIT)
5825 				tp->t_flags2 |= TF2_ECN_SND_CWR;
5826 		}
5827 		break;
5828 	case CC_ECN:
5829 		if (!IN_CONGRECOVERY(tp->t_flags) ||
5830 		    /*
5831 		     * Allow ECN reaction on ACK to CWR, if
5832 		     * that data segment was also CE marked.
5833 		     */
5834 		    SEQ_GEQ(ack, tp->snd_recover)) {
5835 			EXIT_CONGRECOVERY(tp->t_flags);
5836 			KMOD_TCPSTAT_INC(tcps_ecn_rcwnd);
5837 			rack->r_fast_output = 0;
5838 			tp->snd_recover = tp->snd_max + 1;
5839 			if (tp->t_flags2 & TF2_ECN_PERMIT)
5840 				tp->t_flags2 |= TF2_ECN_SND_CWR;
5841 		}
5842 		break;
5843 	case CC_RTO:
5844 		tp->t_dupacks = 0;
5845 		tp->t_bytes_acked = 0;
5846 		rack->r_fast_output = 0;
5847 		EXIT_RECOVERY(tp->t_flags);
5848 		tp->snd_ssthresh = max(2, min(tp->snd_wnd, rack->r_ctl.cwnd_to_use) / 2 /
5849 		    ctf_fixed_maxseg(tp)) * ctf_fixed_maxseg(tp);
5850 		orig_cwnd = tp->snd_cwnd;
5851 		tp->snd_cwnd = ctf_fixed_maxseg(tp);
5852 		rack_log_to_prr(rack, 16, orig_cwnd, line);
5853 		if (tp->t_flags2 & TF2_ECN_PERMIT)
5854 			tp->t_flags2 |= TF2_ECN_SND_CWR;
5855 		break;
5856 	case CC_RTO_ERR:
5857 		KMOD_TCPSTAT_INC(tcps_sndrexmitbad);
5858 		/* RTO was unnecessary, so reset everything. */
5859 		tp->snd_cwnd = tp->snd_cwnd_prev;
5860 		tp->snd_ssthresh = tp->snd_ssthresh_prev;
5861 		tp->snd_recover = tp->snd_recover_prev;
5862 		if (tp->t_flags & TF_WASFRECOVERY) {
5863 			ENTER_FASTRECOVERY(tp->t_flags);
5864 			tp->t_flags &= ~TF_WASFRECOVERY;
5865 		}
5866 		if (tp->t_flags & TF_WASCRECOVERY) {
5867 			ENTER_CONGRECOVERY(tp->t_flags);
5868 			tp->t_flags &= ~TF_WASCRECOVERY;
5869 		}
5870 		tp->snd_nxt = tp->snd_max;
5871 		tp->t_badrxtwin = 0;
5872 		break;
5873 	}
5874 	if ((CC_ALGO(tp)->cong_signal != NULL)  &&
5875 	    (type != CC_RTO)){
5876 		tp->t_ccv.curack = ack;
5877 		CC_ALGO(tp)->cong_signal(&tp->t_ccv, type);
5878 	}
5879 	if ((in_rec_at_entry == 0) && IN_RECOVERY(tp->t_flags)) {
5880 		rack_log_to_prr(rack, 15, cwnd_enter, line);
5881 		if (rack->r_ctl.full_dgp_in_rec)
5882 			rack_client_buffer_level_set(rack);
5883 		rack->r_ctl.dsack_byte_cnt = 0;
5884 		rack->r_ctl.retran_during_recovery = 0;
5885 		rack->r_ctl.rc_cwnd_at_erec = cwnd_enter;
5886 		rack->r_ctl.rc_ssthresh_at_erec = ssthresh_enter;
5887 		rack->r_ent_rec_ns = 1;
5888 	}
5889 }
5890 
5891 static inline void
5892 rack_cc_after_idle(struct tcp_rack *rack, struct tcpcb *tp)
5893 {
5894 	uint32_t i_cwnd;
5895 
5896 	INP_WLOCK_ASSERT(tptoinpcb(tp));
5897 
5898 	if (CC_ALGO(tp)->after_idle != NULL)
5899 		CC_ALGO(tp)->after_idle(&tp->t_ccv);
5900 
5901 	if (tp->snd_cwnd == 1)
5902 		i_cwnd = tp->t_maxseg;		/* SYN(-ACK) lost */
5903 	else
5904 		i_cwnd = rc_init_window(rack);
5905 
5906 	/*
5907 	 * Being idle is no different than the initial window. If the cc
5908 	 * clamps it down below the initial window raise it to the initial
5909 	 * window.
5910 	 */
5911 	if (tp->snd_cwnd < i_cwnd) {
5912 		tp->snd_cwnd = i_cwnd;
5913 	}
5914 }
5915 
5916 /*
5917  * Indicate whether this ack should be delayed.  We can delay the ack if
5918  * following conditions are met:
5919  *	- There is no delayed ack timer in progress.
5920  *	- Our last ack wasn't a 0-sized window. We never want to delay
5921  *	  the ack that opens up a 0-sized window.
5922  *	- LRO wasn't used for this segment. We make sure by checking that the
5923  *	  segment size is not larger than the MSS.
5924  *	- Delayed acks are enabled or this is a half-synchronized T/TCP
5925  *	  connection.
5926  */
5927 #define DELAY_ACK(tp, tlen)			 \
5928 	(((tp->t_flags & TF_RXWIN0SENT) == 0) && \
5929 	((tp->t_flags & TF_DELACK) == 0) &&	 \
5930 	(tlen <= tp->t_maxseg) &&		 \
5931 	(tp->t_delayed_ack || (tp->t_flags & TF_NEEDSYN)))
5932 
5933 static struct rack_sendmap *
5934 rack_find_lowest_rsm(struct tcp_rack *rack)
5935 {
5936 	struct rack_sendmap *rsm;
5937 
5938 	/*
5939 	 * Walk the time-order transmitted list looking for an rsm that is
5940 	 * not acked. This will be the one that was sent the longest time
5941 	 * ago that is still outstanding.
5942 	 */
5943 	TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
5944 		if (rsm->r_flags & RACK_ACKED) {
5945 			continue;
5946 		}
5947 		goto finish;
5948 	}
5949 finish:
5950 	return (rsm);
5951 }
5952 
5953 static struct rack_sendmap *
5954 rack_find_high_nonack(struct tcp_rack *rack, struct rack_sendmap *rsm)
5955 {
5956 	struct rack_sendmap *prsm;
5957 
5958 	/*
5959 	 * Walk the sequence order list backward until we hit and arrive at
5960 	 * the highest seq not acked. In theory when this is called it
5961 	 * should be the last segment (which it was not).
5962 	 */
5963 	prsm = rsm;
5964 
5965 	TQHASH_FOREACH_REVERSE_FROM(prsm, rack->r_ctl.tqh) {
5966 		if (prsm->r_flags & (RACK_ACKED | RACK_HAS_FIN)) {
5967 			continue;
5968 		}
5969 		return (prsm);
5970 	}
5971 	return (NULL);
5972 }
5973 
5974 static uint32_t
5975 rack_calc_thresh_rack(struct tcp_rack *rack, uint32_t srtt, uint32_t cts)
5976 {
5977 	int32_t lro;
5978 	uint32_t thresh;
5979 
5980 	/*
5981 	 * lro is the flag we use to determine if we have seen reordering.
5982 	 * If it gets set we have seen reordering. The reorder logic either
5983 	 * works in one of two ways:
5984 	 *
5985 	 * If reorder-fade is configured, then we track the last time we saw
5986 	 * re-ordering occur. If we reach the point where enough time as
5987 	 * passed we no longer consider reordering has occuring.
5988 	 *
5989 	 * Or if reorder-face is 0, then once we see reordering we consider
5990 	 * the connection to alway be subject to reordering and just set lro
5991 	 * to 1.
5992 	 *
5993 	 * In the end if lro is non-zero we add the extra time for
5994 	 * reordering in.
5995 	 */
5996 	if (srtt == 0)
5997 		srtt = 1;
5998 	if (rack->r_ctl.rc_reorder_ts) {
5999 		if (rack->r_ctl.rc_reorder_fade) {
6000 			if (SEQ_GEQ(cts, rack->r_ctl.rc_reorder_ts)) {
6001 				lro = cts - rack->r_ctl.rc_reorder_ts;
6002 				if (lro == 0) {
6003 					/*
6004 					 * No time as passed since the last
6005 					 * reorder, mark it as reordering.
6006 					 */
6007 					lro = 1;
6008 				}
6009 			} else {
6010 				/* Negative time? */
6011 				lro = 0;
6012 			}
6013 			if (lro > rack->r_ctl.rc_reorder_fade) {
6014 				/* Turn off reordering seen too */
6015 				rack->r_ctl.rc_reorder_ts = 0;
6016 				lro = 0;
6017 			}
6018 		} else {
6019 			/* Reodering does not fade */
6020 			lro = 1;
6021 		}
6022 	} else {
6023 		lro = 0;
6024 	}
6025 	if (rack->rc_rack_tmr_std_based == 0) {
6026 		thresh = srtt + rack->r_ctl.rc_pkt_delay;
6027 	} else {
6028 		/* Standards based pkt-delay is 1/4 srtt */
6029 		thresh = srtt +  (srtt >> 2);
6030 	}
6031 	if (lro && (rack->rc_rack_tmr_std_based == 0)) {
6032 		/* It must be set, if not you get 1/4 rtt */
6033 		if (rack->r_ctl.rc_reorder_shift)
6034 			thresh += (srtt >> rack->r_ctl.rc_reorder_shift);
6035 		else
6036 			thresh += (srtt >> 2);
6037 	}
6038 	if (rack->rc_rack_use_dsack &&
6039 	    lro &&
6040 	    (rack->r_ctl.num_dsack > 0)) {
6041 		/*
6042 		 * We only increase the reordering window if we
6043 		 * have seen reordering <and> we have a DSACK count.
6044 		 */
6045 		thresh += rack->r_ctl.num_dsack * (srtt >> 2);
6046 		rack_log_dsack_event(rack, 4, __LINE__, srtt, thresh);
6047 	}
6048 	/* SRTT * 2 is the ceiling */
6049 	if (thresh > (srtt * 2)) {
6050 		thresh = srtt * 2;
6051 	}
6052 	/* And we don't want it above the RTO max either */
6053 	if (thresh > rack_rto_max) {
6054 		thresh = rack_rto_max;
6055 	}
6056 	rack_log_dsack_event(rack, 6, __LINE__, srtt, thresh);
6057 	return (thresh);
6058 }
6059 
6060 static uint32_t
6061 rack_calc_thresh_tlp(struct tcpcb *tp, struct tcp_rack *rack,
6062 		     struct rack_sendmap *rsm, uint32_t srtt)
6063 {
6064 	struct rack_sendmap *prsm;
6065 	uint32_t thresh, len;
6066 	int segsiz;
6067 
6068 	if (srtt == 0)
6069 		srtt = 1;
6070 	if (rack->r_ctl.rc_tlp_threshold)
6071 		thresh = srtt + (srtt / rack->r_ctl.rc_tlp_threshold);
6072 	else
6073 		thresh = (srtt * 2);
6074 
6075 	/* Get the previous sent packet, if any */
6076 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
6077 	len = rsm->r_end - rsm->r_start;
6078 	if (rack->rack_tlp_threshold_use == TLP_USE_ID) {
6079 		/* Exactly like the ID */
6080 		if (((tp->snd_max - tp->snd_una) - rack->r_ctl.rc_sacked + rack->r_ctl.rc_holes_rxt) <= segsiz) {
6081 			uint32_t alt_thresh;
6082 			/*
6083 			 * Compensate for delayed-ack with the d-ack time.
6084 			 */
6085 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
6086 			if (alt_thresh > thresh)
6087 				thresh = alt_thresh;
6088 		}
6089 	} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_ONE) {
6090 		/* 2.1 behavior */
6091 		prsm = TAILQ_PREV(rsm, rack_head, r_tnext);
6092 		if (prsm && (len <= segsiz)) {
6093 			/*
6094 			 * Two packets outstanding, thresh should be (2*srtt) +
6095 			 * possible inter-packet delay (if any).
6096 			 */
6097 			uint32_t inter_gap = 0;
6098 			int idx, nidx;
6099 
6100 			idx = rsm->r_rtr_cnt - 1;
6101 			nidx = prsm->r_rtr_cnt - 1;
6102 			if (rsm->r_tim_lastsent[nidx] >= prsm->r_tim_lastsent[idx]) {
6103 				/* Yes it was sent later (or at the same time) */
6104 				inter_gap = rsm->r_tim_lastsent[idx] - prsm->r_tim_lastsent[nidx];
6105 			}
6106 			thresh += inter_gap;
6107 		} else if (len <= segsiz) {
6108 			/*
6109 			 * Possibly compensate for delayed-ack.
6110 			 */
6111 			uint32_t alt_thresh;
6112 
6113 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
6114 			if (alt_thresh > thresh)
6115 				thresh = alt_thresh;
6116 		}
6117 	} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_TWO) {
6118 		/* 2.2 behavior */
6119 		if (len <= segsiz) {
6120 			uint32_t alt_thresh;
6121 			/*
6122 			 * Compensate for delayed-ack with the d-ack time.
6123 			 */
6124 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
6125 			if (alt_thresh > thresh)
6126 				thresh = alt_thresh;
6127 		}
6128 	}
6129 	/* Not above an RTO */
6130 	if (thresh > tp->t_rxtcur) {
6131 		thresh = tp->t_rxtcur;
6132 	}
6133 	/* Not above a RTO max */
6134 	if (thresh > rack_rto_max) {
6135 		thresh = rack_rto_max;
6136 	}
6137 	/* Apply user supplied min TLP */
6138 	if (thresh < rack_tlp_min) {
6139 		thresh = rack_tlp_min;
6140 	}
6141 	return (thresh);
6142 }
6143 
6144 static uint32_t
6145 rack_grab_rtt(struct tcpcb *tp, struct tcp_rack *rack)
6146 {
6147 	/*
6148 	 * We want the rack_rtt which is the
6149 	 * last rtt we measured. However if that
6150 	 * does not exist we fallback to the srtt (which
6151 	 * we probably will never do) and then as a last
6152 	 * resort we use RACK_INITIAL_RTO if no srtt is
6153 	 * yet set.
6154 	 */
6155 	if (rack->rc_rack_rtt)
6156 		return (rack->rc_rack_rtt);
6157 	else if (tp->t_srtt == 0)
6158 		return (RACK_INITIAL_RTO);
6159 	return (tp->t_srtt);
6160 }
6161 
6162 static struct rack_sendmap *
6163 rack_check_recovery_mode(struct tcpcb *tp, uint32_t tsused)
6164 {
6165 	/*
6166 	 * Check to see that we don't need to fall into recovery. We will
6167 	 * need to do so if our oldest transmit is past the time we should
6168 	 * have had an ack.
6169 	 */
6170 	struct tcp_rack *rack;
6171 	struct rack_sendmap *rsm;
6172 	int32_t idx;
6173 	uint32_t srtt, thresh;
6174 
6175 	rack = (struct tcp_rack *)tp->t_fb_ptr;
6176 	if (tqhash_empty(rack->r_ctl.tqh)) {
6177 		return (NULL);
6178 	}
6179 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
6180 	if (rsm == NULL)
6181 		return (NULL);
6182 
6183 
6184 	if (rsm->r_flags & RACK_ACKED) {
6185 		rsm = rack_find_lowest_rsm(rack);
6186 		if (rsm == NULL)
6187 			return (NULL);
6188 	}
6189 	idx = rsm->r_rtr_cnt - 1;
6190 	srtt = rack_grab_rtt(tp, rack);
6191 	thresh = rack_calc_thresh_rack(rack, srtt, tsused);
6192 	if (TSTMP_LT(tsused, ((uint32_t)rsm->r_tim_lastsent[idx]))) {
6193 		return (NULL);
6194 	}
6195 	if ((tsused - ((uint32_t)rsm->r_tim_lastsent[idx])) < thresh) {
6196 		return (NULL);
6197 	}
6198 	/* Ok if we reach here we are over-due and this guy can be sent */
6199 	rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
6200 	return (rsm);
6201 }
6202 
6203 static uint32_t
6204 rack_get_persists_timer_val(struct tcpcb *tp, struct tcp_rack *rack)
6205 {
6206 	int32_t t;
6207 	int32_t tt;
6208 	uint32_t ret_val;
6209 
6210 	t = (tp->t_srtt + (tp->t_rttvar << 2));
6211 	RACK_TCPT_RANGESET(tt, t * tcp_backoff[tp->t_rxtshift],
6212  	    rack_persist_min, rack_persist_max, rack->r_ctl.timer_slop);
6213 	rack->r_ctl.rc_hpts_flags |= PACE_TMR_PERSIT;
6214 	ret_val = (uint32_t)tt;
6215 	return (ret_val);
6216 }
6217 
6218 static uint32_t
6219 rack_timer_start(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int sup_rack)
6220 {
6221 	/*
6222 	 * Start the FR timer, we do this based on getting the first one in
6223 	 * the rc_tmap. Note that if its NULL we must stop the timer. in all
6224 	 * events we need to stop the running timer (if its running) before
6225 	 * starting the new one.
6226 	 */
6227 	uint32_t thresh, exp, to, srtt, time_since_sent, tstmp_touse;
6228 	uint32_t srtt_cur;
6229 	int32_t idx;
6230 	int32_t is_tlp_timer = 0;
6231 	struct rack_sendmap *rsm;
6232 
6233 	if (rack->t_timers_stopped) {
6234 		/* All timers have been stopped none are to run */
6235 		return (0);
6236 	}
6237 	if (rack->rc_in_persist) {
6238 		/* We can't start any timer in persists */
6239 		return (rack_get_persists_timer_val(tp, rack));
6240 	}
6241 	rack->rc_on_min_to = 0;
6242 	if ((tp->t_state < TCPS_ESTABLISHED) ||
6243 	    (rack->sack_attack_disable > 0) ||
6244 	    ((tp->t_flags & TF_SACK_PERMIT) == 0)) {
6245 		goto activate_rxt;
6246 	}
6247 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
6248 	if ((rsm == NULL) || sup_rack) {
6249 		/* Nothing on the send map or no rack */
6250 activate_rxt:
6251 		time_since_sent = 0;
6252 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
6253 		if (rsm) {
6254 			/*
6255 			 * Should we discount the RTX timer any?
6256 			 *
6257 			 * We want to discount it the smallest amount.
6258 			 * If a timer (Rack/TLP or RXT) has gone off more
6259 			 * recently thats the discount we want to use (now - timer time).
6260 			 * If the retransmit of the oldest packet was more recent then
6261 			 * we want to use that (now - oldest-packet-last_transmit_time).
6262 			 *
6263 			 */
6264 			idx = rsm->r_rtr_cnt - 1;
6265 			if (TSTMP_GEQ(rack->r_ctl.rc_tlp_rxt_last_time, ((uint32_t)rsm->r_tim_lastsent[idx])))
6266 				tstmp_touse = (uint32_t)rack->r_ctl.rc_tlp_rxt_last_time;
6267 			else
6268 				tstmp_touse = (uint32_t)rsm->r_tim_lastsent[idx];
6269 			if (TSTMP_GT(cts, tstmp_touse))
6270 			    time_since_sent = cts - tstmp_touse;
6271 		}
6272 		if (SEQ_LT(tp->snd_una, tp->snd_max) ||
6273 		    sbavail(&tptosocket(tp)->so_snd)) {
6274 			rack->r_ctl.rc_hpts_flags |= PACE_TMR_RXT;
6275 			to = tp->t_rxtcur;
6276 			if (to > time_since_sent)
6277 				to -= time_since_sent;
6278 			else
6279 				to = rack->r_ctl.rc_min_to;
6280 			if (to == 0)
6281 				to = 1;
6282 			/* Special case for KEEPINIT */
6283 			if ((TCPS_HAVEESTABLISHED(tp->t_state) == 0) &&
6284 			    (TP_KEEPINIT(tp) != 0) &&
6285 			    rsm) {
6286 				/*
6287 				 * We have to put a ceiling on the rxt timer
6288 				 * of the keep-init timeout.
6289 				 */
6290 				uint32_t max_time, red;
6291 
6292 				max_time = TICKS_2_USEC(TP_KEEPINIT(tp));
6293 				if (TSTMP_GT(cts, (uint32_t)rsm->r_tim_lastsent[0])) {
6294 					red = (cts - (uint32_t)rsm->r_tim_lastsent[0]);
6295 					if (red < max_time)
6296 						max_time -= red;
6297 					else
6298 						max_time = 1;
6299 				}
6300 				/* Reduce timeout to the keep value if needed */
6301 				if (max_time < to)
6302 					to = max_time;
6303 			}
6304 			return (to);
6305 		}
6306 		return (0);
6307 	}
6308 	if (rsm->r_flags & RACK_ACKED) {
6309 		rsm = rack_find_lowest_rsm(rack);
6310 		if (rsm == NULL) {
6311 			/* No lowest? */
6312 			goto activate_rxt;
6313 		}
6314 	}
6315 	if (rack->sack_attack_disable) {
6316 		/*
6317 		 * We don't want to do
6318 		 * any TLP's if you are an attacker.
6319 		 * Though if you are doing what
6320 		 * is expected you may still have
6321 		 * SACK-PASSED marks.
6322 		 */
6323 		goto activate_rxt;
6324 	}
6325 	/* Convert from ms to usecs */
6326 	if ((rsm->r_flags & RACK_SACK_PASSED) ||
6327 	    (rsm->r_flags & RACK_RWND_COLLAPSED) ||
6328 	    (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
6329 		if ((tp->t_flags & TF_SENTFIN) &&
6330 		    ((tp->snd_max - tp->snd_una) == 1) &&
6331 		    (rsm->r_flags & RACK_HAS_FIN)) {
6332 			/*
6333 			 * We don't start a rack timer if all we have is a
6334 			 * FIN outstanding.
6335 			 */
6336 			goto activate_rxt;
6337 		}
6338 		if ((rack->use_rack_rr == 0) &&
6339 		    (IN_FASTRECOVERY(tp->t_flags)) &&
6340 		    (rack->rack_no_prr == 0) &&
6341 		     (rack->r_ctl.rc_prr_sndcnt  < ctf_fixed_maxseg(tp))) {
6342 			/*
6343 			 * We are not cheating, in recovery  and
6344 			 * not enough ack's to yet get our next
6345 			 * retransmission out.
6346 			 *
6347 			 * Note that classified attackers do not
6348 			 * get to use the rack-cheat.
6349 			 */
6350 			goto activate_tlp;
6351 		}
6352 		srtt = rack_grab_rtt(tp, rack);
6353 		thresh = rack_calc_thresh_rack(rack, srtt, cts);
6354 		idx = rsm->r_rtr_cnt - 1;
6355 		exp = ((uint32_t)rsm->r_tim_lastsent[idx]) + thresh;
6356 		if (SEQ_GEQ(exp, cts)) {
6357 			to = exp - cts;
6358 			if (to < rack->r_ctl.rc_min_to) {
6359 				to = rack->r_ctl.rc_min_to;
6360 				if (rack->r_rr_config == 3)
6361 					rack->rc_on_min_to = 1;
6362 			}
6363 		} else {
6364 			to = rack->r_ctl.rc_min_to;
6365 			if (rack->r_rr_config == 3)
6366 				rack->rc_on_min_to = 1;
6367 		}
6368 	} else {
6369 		/* Ok we need to do a TLP not RACK */
6370 activate_tlp:
6371 		if ((rack->rc_tlp_in_progress != 0) &&
6372 		    (rack->r_ctl.rc_tlp_cnt_out >= rack_tlp_limit)) {
6373 			/*
6374 			 * The previous send was a TLP and we have sent
6375 			 * N TLP's without sending new data.
6376 			 */
6377 			goto activate_rxt;
6378 		}
6379 		rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
6380 		if (rsm == NULL) {
6381 			/* We found no rsm to TLP with. */
6382 			goto activate_rxt;
6383 		}
6384 		if (rsm->r_flags & RACK_HAS_FIN) {
6385 			/* If its a FIN we dont do TLP */
6386 			rsm = NULL;
6387 			goto activate_rxt;
6388 		}
6389 		idx = rsm->r_rtr_cnt - 1;
6390 		time_since_sent = 0;
6391 		if (TSTMP_GEQ(((uint32_t)rsm->r_tim_lastsent[idx]), rack->r_ctl.rc_tlp_rxt_last_time))
6392 			tstmp_touse = (uint32_t)rsm->r_tim_lastsent[idx];
6393 		else
6394 			tstmp_touse = (uint32_t)rack->r_ctl.rc_tlp_rxt_last_time;
6395 		if (TSTMP_GT(cts, tstmp_touse))
6396 		    time_since_sent = cts - tstmp_touse;
6397 		is_tlp_timer = 1;
6398 		if (tp->t_srtt) {
6399 			if ((rack->rc_srtt_measure_made == 0) &&
6400 			    (tp->t_srtt == 1)) {
6401 				/*
6402 				 * If another stack as run and set srtt to 1,
6403 				 * then the srtt was 0, so lets use the initial.
6404 				 */
6405 				srtt = RACK_INITIAL_RTO;
6406 			} else {
6407 				srtt_cur = tp->t_srtt;
6408 				srtt = srtt_cur;
6409 			}
6410 		} else
6411 			srtt = RACK_INITIAL_RTO;
6412 		/*
6413 		 * If the SRTT is not keeping up and the
6414 		 * rack RTT has spiked we want to use
6415 		 * the last RTT not the smoothed one.
6416 		 */
6417 		if (rack_tlp_use_greater &&
6418 		    tp->t_srtt &&
6419 		    (srtt < rack_grab_rtt(tp, rack))) {
6420 			srtt = rack_grab_rtt(tp, rack);
6421 		}
6422 		thresh = rack_calc_thresh_tlp(tp, rack, rsm, srtt);
6423 		if (thresh > time_since_sent) {
6424 			to = thresh - time_since_sent;
6425 		} else {
6426 			to = rack->r_ctl.rc_min_to;
6427 			rack_log_alt_to_to_cancel(rack,
6428 						  thresh,		/* flex1 */
6429 						  time_since_sent,	/* flex2 */
6430 						  tstmp_touse,		/* flex3 */
6431 						  rack->r_ctl.rc_tlp_rxt_last_time, /* flex4 */
6432 						  (uint32_t)rsm->r_tim_lastsent[idx],
6433 						  srtt,
6434 						  idx, 99);
6435 		}
6436 		if (to < rack_tlp_min) {
6437 			to = rack_tlp_min;
6438 		}
6439 		if (to > TICKS_2_USEC(TCPTV_REXMTMAX)) {
6440 			/*
6441 			 * If the TLP time works out to larger than the max
6442 			 * RTO lets not do TLP.. just RTO.
6443 			 */
6444 			goto activate_rxt;
6445 		}
6446 	}
6447 	if (is_tlp_timer == 0) {
6448 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_RACK;
6449 	} else {
6450 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_TLP;
6451 	}
6452 	if (to == 0)
6453 		to = 1;
6454 	return (to);
6455 }
6456 
6457 static void
6458 rack_enter_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, tcp_seq snd_una)
6459 {
6460 	struct timeval tv;
6461 
6462 	if (rack->rc_in_persist == 0) {
6463 		if (tp->t_flags & TF_GPUTINPROG) {
6464 			/*
6465 			 * Stop the goodput now, the calling of the
6466 			 * measurement function clears the flag.
6467 			 */
6468 			rack_do_goodput_measurement(tp, rack, tp->snd_una, __LINE__,
6469 						    RACK_QUALITY_PERSIST);
6470 		}
6471 #ifdef NETFLIX_SHARED_CWND
6472 		if (rack->r_ctl.rc_scw) {
6473 			tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
6474 			rack->rack_scwnd_is_idle = 1;
6475 		}
6476 #endif
6477 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(&tv);
6478 		if (rack->lt_bw_up) {
6479 			/* Suspend our LT BW measurement */
6480 			uint64_t tmark;
6481 
6482 			rack->r_ctl.lt_bw_bytes += (snd_una - rack->r_ctl.lt_seq);
6483 			rack->r_ctl.lt_seq = snd_una;
6484 			tmark = tcp_tv_to_lusectick(&tv);
6485 			rack->r_ctl.lt_bw_time += (tmark - rack->r_ctl.lt_timemark);
6486 			rack->r_ctl.lt_timemark = tmark;
6487 			rack->lt_bw_up = 0;
6488 			rack->r_persist_lt_bw_off = 1;
6489 		}
6490 		if (rack->r_ctl.rc_went_idle_time == 0)
6491 			rack->r_ctl.rc_went_idle_time = 1;
6492 		rack_timer_cancel(tp, rack, cts, __LINE__);
6493 		rack->r_ctl.persist_lost_ends = 0;
6494 		rack->probe_not_answered = 0;
6495 		rack->forced_ack = 0;
6496 		tp->t_rxtshift = 0;
6497 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
6498 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
6499 		rack->rc_in_persist = 1;
6500 	}
6501 }
6502 
6503 static void
6504 rack_exit_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6505 {
6506 	struct timeval tv;
6507 	uint32_t t_time;
6508 
6509 	if (tcp_in_hpts(rack->rc_tp)) {
6510 		tcp_hpts_remove(rack->rc_tp);
6511 		rack->r_ctl.rc_hpts_flags = 0;
6512 	}
6513 #ifdef NETFLIX_SHARED_CWND
6514 	if (rack->r_ctl.rc_scw) {
6515 		tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
6516 		rack->rack_scwnd_is_idle = 0;
6517 	}
6518 #endif
6519 	t_time = tcp_get_usecs(&tv);
6520 	if (rack->rc_gp_dyn_mul &&
6521 	    (rack->use_fixed_rate == 0) &&
6522 	    (rack->rc_always_pace)) {
6523 		/*
6524 		 * Do we count this as if a probe-rtt just
6525 		 * finished?
6526 		 */
6527 		uint32_t time_idle, idle_min;
6528 
6529 		time_idle = t_time - rack->r_ctl.rc_went_idle_time;
6530 		idle_min = rack_min_probertt_hold;
6531 		if (rack_probertt_gpsrtt_cnt_div) {
6532 			uint64_t extra;
6533 			extra = (uint64_t)rack->r_ctl.rc_gp_srtt *
6534 				(uint64_t)rack_probertt_gpsrtt_cnt_mul;
6535 			extra /= (uint64_t)rack_probertt_gpsrtt_cnt_div;
6536 			idle_min += (uint32_t)extra;
6537 		}
6538 		if (time_idle >= idle_min) {
6539 			/* Yes, we count it as a probe-rtt. */
6540 			uint32_t us_cts;
6541 
6542 			us_cts = tcp_get_usecs(NULL);
6543 			if (rack->in_probe_rtt == 0) {
6544 				rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
6545 				rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
6546 				rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
6547 				rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
6548 			} else {
6549 				rack_exit_probertt(rack, us_cts);
6550 			}
6551 		}
6552 	}
6553 	if (rack->r_persist_lt_bw_off) {
6554 		/* Continue where we left off */
6555 		rack->r_ctl.lt_timemark = tcp_tv_to_lusectick(&tv);
6556 		rack->lt_bw_up = 1;
6557 		rack->r_persist_lt_bw_off = 0;
6558 	}
6559 	rack->rc_in_persist = 0;
6560 	rack->r_ctl.rc_went_idle_time = 0;
6561 	tp->t_rxtshift = 0;
6562 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
6563 	   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
6564 	rack->r_ctl.rc_agg_delayed = 0;
6565 	rack->r_early = 0;
6566 	rack->r_late = 0;
6567 	rack->r_ctl.rc_agg_early = 0;
6568 }
6569 
6570 static void
6571 rack_log_hpts_diag(struct tcp_rack *rack, uint32_t cts,
6572 		   struct hpts_diag *diag, struct timeval *tv)
6573 {
6574 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
6575 		union tcp_log_stackspecific log;
6576 
6577 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
6578 		log.u_bbr.flex1 = diag->p_nxt_slot;
6579 		log.u_bbr.flex2 = diag->p_cur_slot;
6580 		log.u_bbr.flex3 = diag->slot_req;
6581 		log.u_bbr.flex4 = diag->inp_hptsslot;
6582 		log.u_bbr.flex5 = diag->slot_remaining;
6583 		log.u_bbr.flex6 = diag->need_new_to;
6584 		log.u_bbr.flex7 = diag->p_hpts_active;
6585 		log.u_bbr.flex8 = diag->p_on_min_sleep;
6586 		/* Hijack other fields as needed */
6587 		log.u_bbr.epoch = diag->have_slept;
6588 		log.u_bbr.lt_epoch = diag->yet_to_sleep;
6589 		log.u_bbr.pkts_out = diag->co_ret;
6590 		log.u_bbr.applimited = diag->hpts_sleep_time;
6591 		log.u_bbr.delivered = diag->p_prev_slot;
6592 		log.u_bbr.inflight = diag->p_runningslot;
6593 		log.u_bbr.bw_inuse = diag->wheel_slot;
6594 		log.u_bbr.rttProp = diag->wheel_cts;
6595 		log.u_bbr.timeStamp = cts;
6596 		log.u_bbr.delRate = diag->maxslots;
6597 		log.u_bbr.cur_del_rate = diag->p_curtick;
6598 		log.u_bbr.cur_del_rate <<= 32;
6599 		log.u_bbr.cur_del_rate |= diag->p_lasttick;
6600 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
6601 		    &rack->rc_inp->inp_socket->so_rcv,
6602 		    &rack->rc_inp->inp_socket->so_snd,
6603 		    BBR_LOG_HPTSDIAG, 0,
6604 		    0, &log, false, tv);
6605 	}
6606 
6607 }
6608 
6609 static void
6610 rack_log_wakeup(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb, uint32_t len, int type)
6611 {
6612 	if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp)) {
6613 		union tcp_log_stackspecific log;
6614 		struct timeval tv;
6615 
6616 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
6617 		log.u_bbr.flex1 = sb->sb_flags;
6618 		log.u_bbr.flex2 = len;
6619 		log.u_bbr.flex3 = sb->sb_state;
6620 		log.u_bbr.flex8 = type;
6621 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
6622 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
6623 		    &rack->rc_inp->inp_socket->so_rcv,
6624 		    &rack->rc_inp->inp_socket->so_snd,
6625 		    TCP_LOG_SB_WAKE, 0,
6626 		    len, &log, false, &tv);
6627 	}
6628 }
6629 
6630 static void
6631 rack_start_hpts_timer(struct tcp_rack *rack, struct tcpcb *tp, uint32_t cts,
6632       int32_t slot, uint32_t tot_len_this_send, int sup_rack)
6633 {
6634 	struct hpts_diag diag;
6635 	struct inpcb *inp = tptoinpcb(tp);
6636 	struct timeval tv;
6637 	uint32_t delayed_ack = 0;
6638 	uint32_t hpts_timeout;
6639 	uint32_t entry_slot = slot;
6640 	uint8_t stopped;
6641 	uint32_t left = 0;
6642 	uint32_t us_cts;
6643 
6644 	if ((tp->t_state == TCPS_CLOSED) ||
6645 	    (tp->t_state == TCPS_LISTEN)) {
6646 		return;
6647 	}
6648 	if (tcp_in_hpts(tp)) {
6649 		/* Already on the pacer */
6650 		return;
6651 	}
6652 	stopped = rack->rc_tmr_stopped;
6653 	if (stopped && TSTMP_GT(rack->r_ctl.rc_timer_exp, cts)) {
6654 		left = rack->r_ctl.rc_timer_exp - cts;
6655 	}
6656 	rack->r_ctl.rc_timer_exp = 0;
6657 	rack->r_ctl.rc_hpts_flags = 0;
6658 	us_cts = tcp_get_usecs(&tv);
6659 	/* Now early/late accounting */
6660 	rack_log_pacing_delay_calc(rack, entry_slot, slot, 0, 0, 0, 26, __LINE__, NULL, 0);
6661 	if (rack->r_early && (rack->rc_ack_can_sendout_data == 0)) {
6662 		/*
6663 		 * We have a early carry over set,
6664 		 * we can always add more time so we
6665 		 * can always make this compensation.
6666 		 *
6667 		 * Note if ack's are allowed to wake us do not
6668 		 * penalize the next timer for being awoke
6669 		 * by an ack aka the rc_agg_early (non-paced mode).
6670 		 */
6671 		slot += rack->r_ctl.rc_agg_early;
6672 		rack->r_early = 0;
6673 		rack->r_ctl.rc_agg_early = 0;
6674 	}
6675 	if (rack->r_late) {
6676 		/*
6677 		 * This is harder, we can
6678 		 * compensate some but it
6679 		 * really depends on what
6680 		 * the current pacing time is.
6681 		 */
6682 		if (rack->r_ctl.rc_agg_delayed >= slot) {
6683 			/*
6684 			 * We can't compensate for it all.
6685 			 * And we have to have some time
6686 			 * on the clock. We always have a min
6687 			 * 10 slots (10 x 10 i.e. 100 usecs).
6688 			 */
6689 			if (slot <= HPTS_TICKS_PER_SLOT) {
6690 				/* We gain delay */
6691 				rack->r_ctl.rc_agg_delayed += (HPTS_TICKS_PER_SLOT - slot);
6692 				slot = HPTS_TICKS_PER_SLOT;
6693 			} else {
6694 				/* We take off some */
6695 				rack->r_ctl.rc_agg_delayed -= (slot - HPTS_TICKS_PER_SLOT);
6696 				slot = HPTS_TICKS_PER_SLOT;
6697 			}
6698 		} else {
6699 			slot -= rack->r_ctl.rc_agg_delayed;
6700 			rack->r_ctl.rc_agg_delayed = 0;
6701 			/* Make sure we have 100 useconds at minimum */
6702 			if (slot < HPTS_TICKS_PER_SLOT) {
6703 				rack->r_ctl.rc_agg_delayed = HPTS_TICKS_PER_SLOT - slot;
6704 				slot = HPTS_TICKS_PER_SLOT;
6705 			}
6706 			if (rack->r_ctl.rc_agg_delayed == 0)
6707 				rack->r_late = 0;
6708 		}
6709 	}
6710 	hpts_timeout = rack_timer_start(tp, rack, cts, sup_rack);
6711 #ifdef TCP_SAD_DETECTION
6712 	if (rack->sack_attack_disable &&
6713 	    (rack->r_ctl.ack_during_sd > 0) &&
6714 	    (slot < tcp_sad_pacing_interval)) {
6715 		/*
6716 		 * We have a potential attacker on
6717 		 * the line. We have possibly some
6718 		 * (or now) pacing time set. We want to
6719 		 * slow down the processing of sacks by some
6720 		 * amount (if it is an attacker). Set the default
6721 		 * slot for attackers in place (unless the original
6722 		 * interval is longer). Its stored in
6723 		 * micro-seconds, so lets convert to msecs.
6724 		 */
6725 		slot = tcp_sad_pacing_interval;
6726 		rack_log_type_bbrsnd(rack, tot_len_this_send, slot, us_cts, &tv, __LINE__);
6727 		rack->r_ctl.ack_during_sd = 0;
6728 	}
6729 #endif
6730 	if (tp->t_flags & TF_DELACK) {
6731 		delayed_ack = TICKS_2_USEC(tcp_delacktime);
6732 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_DELACK;
6733 	}
6734 	if (delayed_ack && ((hpts_timeout == 0) ||
6735 			    (delayed_ack < hpts_timeout)))
6736 		hpts_timeout = delayed_ack;
6737 	else
6738 		rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
6739 	/*
6740 	 * If no timers are going to run and we will fall off the hptsi
6741 	 * wheel, we resort to a keep-alive timer if its configured.
6742 	 */
6743 	if ((hpts_timeout == 0) &&
6744 	    (slot == 0)) {
6745 		if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
6746 		    (tp->t_state <= TCPS_CLOSING)) {
6747 			/*
6748 			 * Ok we have no timer (persists, rack, tlp, rxt  or
6749 			 * del-ack), we don't have segments being paced. So
6750 			 * all that is left is the keepalive timer.
6751 			 */
6752 			if (TCPS_HAVEESTABLISHED(tp->t_state)) {
6753 				/* Get the established keep-alive time */
6754 				hpts_timeout = TICKS_2_USEC(TP_KEEPIDLE(tp));
6755 			} else {
6756 				/*
6757 				 * Get the initial setup keep-alive time,
6758 				 * note that this is probably not going to
6759 				 * happen, since rack will be running a rxt timer
6760 				 * if a SYN of some sort is outstanding. It is
6761 				 * actually handled in rack_timeout_rxt().
6762 				 */
6763 				hpts_timeout = TICKS_2_USEC(TP_KEEPINIT(tp));
6764 			}
6765 			rack->r_ctl.rc_hpts_flags |= PACE_TMR_KEEP;
6766 			if (rack->in_probe_rtt) {
6767 				/*
6768 				 * We want to instead not wake up a long time from
6769 				 * now but to wake up about the time we would
6770 				 * exit probe-rtt and initiate a keep-alive ack.
6771 				 * This will get us out of probe-rtt and update
6772 				 * our min-rtt.
6773 				 */
6774 				hpts_timeout = rack_min_probertt_hold;
6775 			}
6776 		}
6777 	}
6778 	if (left && (stopped & (PACE_TMR_KEEP | PACE_TMR_DELACK)) ==
6779 	    (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK)) {
6780 		/*
6781 		 * RACK, TLP, persists and RXT timers all are restartable
6782 		 * based on actions input .. i.e we received a packet (ack
6783 		 * or sack) and that changes things (rw, or snd_una etc).
6784 		 * Thus we can restart them with a new value. For
6785 		 * keep-alive, delayed_ack we keep track of what was left
6786 		 * and restart the timer with a smaller value.
6787 		 */
6788 		if (left < hpts_timeout)
6789 			hpts_timeout = left;
6790 	}
6791 	if (hpts_timeout) {
6792 		/*
6793 		 * Hack alert for now we can't time-out over 2,147,483
6794 		 * seconds (a bit more than 596 hours), which is probably ok
6795 		 * :).
6796 		 */
6797 		if (hpts_timeout > 0x7ffffffe)
6798 			hpts_timeout = 0x7ffffffe;
6799 		rack->r_ctl.rc_timer_exp = cts + hpts_timeout;
6800 	}
6801 	rack_log_pacing_delay_calc(rack, entry_slot, slot, hpts_timeout, 0, 0, 27, __LINE__, NULL, 0);
6802 	if ((rack->gp_ready == 0) &&
6803 	    (rack->use_fixed_rate == 0) &&
6804 	    (hpts_timeout < slot) &&
6805 	    (rack->r_ctl.rc_hpts_flags & (PACE_TMR_TLP|PACE_TMR_RXT))) {
6806 		/*
6807 		 * We have no good estimate yet for the
6808 		 * old clunky burst mitigation or the
6809 		 * real pacing. And the tlp or rxt is smaller
6810 		 * than the pacing calculation. Lets not
6811 		 * pace that long since we know the calculation
6812 		 * so far is not accurate.
6813 		 */
6814 		slot = hpts_timeout;
6815 	}
6816 	/**
6817 	 * Turn off all the flags for queuing by default. The
6818 	 * flags have important meanings to what happens when
6819 	 * LRO interacts with the transport. Most likely (by default now)
6820 	 * mbuf_queueing and ack compression are on. So the transport
6821 	 * has a couple of flags that control what happens (if those
6822 	 * are not on then these flags won't have any effect since it
6823 	 * won't go through the queuing LRO path).
6824 	 *
6825 	 * TF2_MBUF_QUEUE_READY - This flags says that I am busy
6826 	 *                        pacing output, so don't disturb. But
6827 	 *                        it also means LRO can wake me if there
6828 	 *                        is a SACK arrival.
6829 	 *
6830 	 * TF2_DONT_SACK_QUEUE - This flag is used in conjunction
6831 	 *                       with the above flag (QUEUE_READY) and
6832 	 *                       when present it says don't even wake me
6833 	 *                       if a SACK arrives.
6834 	 *
6835 	 * The idea behind these flags is that if we are pacing we
6836 	 * set the MBUF_QUEUE_READY and only get woken up if
6837 	 * a SACK arrives (which could change things) or if
6838 	 * our pacing timer expires. If, however, we have a rack
6839 	 * timer running, then we don't even want a sack to wake
6840 	 * us since the rack timer has to expire before we can send.
6841 	 *
6842 	 * Other cases should usually have none of the flags set
6843 	 * so LRO can call into us.
6844 	 */
6845 	tp->t_flags2 &= ~(TF2_DONT_SACK_QUEUE|TF2_MBUF_QUEUE_READY);
6846 	if (slot) {
6847 		rack->r_ctl.rc_hpts_flags |= PACE_PKT_OUTPUT;
6848 		rack->r_ctl.rc_last_output_to = us_cts + slot;
6849 		/*
6850 		 * A pacing timer (slot) is being set, in
6851 		 * such a case we cannot send (we are blocked by
6852 		 * the timer). So lets tell LRO that it should not
6853 		 * wake us unless there is a SACK. Note this only
6854 		 * will be effective if mbuf queueing is on or
6855 		 * compressed acks are being processed.
6856 		 */
6857 		tp->t_flags2 |= TF2_MBUF_QUEUE_READY;
6858 		/*
6859 		 * But wait if we have a Rack timer running
6860 		 * even a SACK should not disturb us (with
6861 		 * the exception of r_rr_config 3).
6862 		 */
6863 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK) {
6864 			if (rack->r_rr_config != 3)
6865 				tp->t_flags2 |= TF2_DONT_SACK_QUEUE;
6866 			else if (rack->rc_pace_dnd) {
6867 				if (IN_RECOVERY(tp->t_flags)) {
6868 					/*
6869 					 * When DND is on, we only let a sack
6870 					 * interrupt us if we are not in recovery.
6871 					 *
6872 					 * If DND is off, then we never hit here
6873 					 * and let all sacks wake us up.
6874 					 *
6875 					 */
6876 					tp->t_flags2 |= TF2_DONT_SACK_QUEUE;
6877 				}
6878 			}
6879 		}
6880 		/* For sack attackers we want to ignore sack */
6881 		if (rack->sack_attack_disable == 1) {
6882 			tp->t_flags2 |= (TF2_DONT_SACK_QUEUE |
6883 			    TF2_MBUF_QUEUE_READY);
6884 		} else if (rack->rc_ack_can_sendout_data) {
6885 			/*
6886 			 * Ahh but wait, this is that special case
6887 			 * where the pacing timer can be disturbed
6888 			 * backout the changes (used for non-paced
6889 			 * burst limiting).
6890 			 */
6891 			tp->t_flags2 &= ~(TF2_DONT_SACK_QUEUE |
6892 			    TF2_MBUF_QUEUE_READY);
6893 		}
6894 		if ((rack->use_rack_rr) &&
6895 		    (rack->r_rr_config < 2) &&
6896 		    ((hpts_timeout) && (hpts_timeout < slot))) {
6897 			/*
6898 			 * Arrange for the hpts to kick back in after the
6899 			 * t-o if the t-o does not cause a send.
6900 			 */
6901 			(void)tcp_hpts_insert_diag(tp, HPTS_USEC_TO_SLOTS(hpts_timeout),
6902 						   __LINE__, &diag);
6903 			rack_log_hpts_diag(rack, us_cts, &diag, &tv);
6904 			rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
6905 		} else {
6906 			(void)tcp_hpts_insert_diag(tp, HPTS_USEC_TO_SLOTS(slot),
6907 						   __LINE__, &diag);
6908 			rack_log_hpts_diag(rack, us_cts, &diag, &tv);
6909 			rack_log_to_start(rack, cts, hpts_timeout, slot, 1);
6910 		}
6911 	} else if (hpts_timeout) {
6912 		/*
6913 		 * With respect to t_flags2(?) here, lets let any new acks wake
6914 		 * us up here. Since we are not pacing (no pacing timer), output
6915 		 * can happen so we should let it. If its a Rack timer, then any inbound
6916 		 * packet probably won't change the sending (we will be blocked)
6917 		 * but it may change the prr stats so letting it in (the set defaults
6918 		 * at the start of this block) are good enough.
6919 		 */
6920 		rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
6921 		(void)tcp_hpts_insert_diag(tp, HPTS_USEC_TO_SLOTS(hpts_timeout),
6922 					   __LINE__, &diag);
6923 		rack_log_hpts_diag(rack, us_cts, &diag, &tv);
6924 		rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
6925 	} else {
6926 		/* No timer starting */
6927 #ifdef INVARIANTS
6928 		if (SEQ_GT(tp->snd_max, tp->snd_una)) {
6929 			panic("tp:%p rack:%p tlts:%d cts:%u slot:%u pto:%u -- no timer started?",
6930 			    tp, rack, tot_len_this_send, cts, slot, hpts_timeout);
6931 		}
6932 #endif
6933 	}
6934 	rack->rc_tmr_stopped = 0;
6935 	if (slot)
6936 		rack_log_type_bbrsnd(rack, tot_len_this_send, slot, us_cts, &tv, __LINE__);
6937 }
6938 
6939 /*
6940  * RACK Timer, here we simply do logging and house keeping.
6941  * the normal rack_output() function will call the
6942  * appropriate thing to check if we need to do a RACK retransmit.
6943  * We return 1, saying don't proceed with rack_output only
6944  * when all timers have been stopped (destroyed PCB?).
6945  */
6946 static int
6947 rack_timeout_rack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6948 {
6949 	/*
6950 	 * This timer simply provides an internal trigger to send out data.
6951 	 * The check_recovery_mode call will see if there are needed
6952 	 * retransmissions, if so we will enter fast-recovery. The output
6953 	 * call may or may not do the same thing depending on sysctl
6954 	 * settings.
6955 	 */
6956 	struct rack_sendmap *rsm;
6957 
6958 	counter_u64_add(rack_to_tot, 1);
6959 	if (rack->r_state && (rack->r_state != tp->t_state))
6960 		rack_set_state(tp, rack);
6961 	rack->rc_on_min_to = 0;
6962 	rsm = rack_check_recovery_mode(tp, cts);
6963 	rack_log_to_event(rack, RACK_TO_FRM_RACK, rsm);
6964 	if (rsm) {
6965 		rack->r_ctl.rc_resend = rsm;
6966 		rack->r_timer_override = 1;
6967 		if (rack->use_rack_rr) {
6968 			/*
6969 			 * Don't accumulate extra pacing delay
6970 			 * we are allowing the rack timer to
6971 			 * over-ride pacing i.e. rrr takes precedence
6972 			 * if the pacing interval is longer than the rrr
6973 			 * time (in other words we get the min pacing
6974 			 * time versus rrr pacing time).
6975 			 */
6976 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
6977 		}
6978 	}
6979 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RACK;
6980 	if (rsm == NULL) {
6981 		/* restart a timer and return 1 */
6982 		rack_start_hpts_timer(rack, tp, cts,
6983 				      0, 0, 0);
6984 		return (1);
6985 	}
6986 	return (0);
6987 }
6988 
6989 
6990 
6991 static void
6992 rack_adjust_orig_mlen(struct rack_sendmap *rsm)
6993 {
6994 
6995 	if ((M_TRAILINGROOM(rsm->m) != rsm->orig_t_space)) {
6996 		/*
6997 		 * The trailing space changed, mbufs can grow
6998 		 * at the tail but they can't shrink from
6999 		 * it, KASSERT that. Adjust the orig_m_len to
7000 		 * compensate for this change.
7001 		 */
7002 		KASSERT((rsm->orig_t_space > M_TRAILINGROOM(rsm->m)),
7003 			("mbuf:%p rsm:%p trailing_space:%jd ots:%u oml:%u mlen:%u\n",
7004 			 rsm->m,
7005 			 rsm,
7006 			 (intmax_t)M_TRAILINGROOM(rsm->m),
7007 			 rsm->orig_t_space,
7008 			 rsm->orig_m_len,
7009 			 rsm->m->m_len));
7010 		rsm->orig_m_len += (rsm->orig_t_space - M_TRAILINGROOM(rsm->m));
7011 		rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
7012 	}
7013 	if (rsm->m->m_len < rsm->orig_m_len) {
7014 		/*
7015 		 * Mbuf shrank, trimmed off the top by an ack, our
7016 		 * offset changes.
7017 		 */
7018 		KASSERT((rsm->soff >= (rsm->orig_m_len - rsm->m->m_len)),
7019 			("mbuf:%p len:%u rsm:%p oml:%u soff:%u\n",
7020 			 rsm->m, rsm->m->m_len,
7021 			 rsm, rsm->orig_m_len,
7022 			 rsm->soff));
7023 		if (rsm->soff >= (rsm->orig_m_len - rsm->m->m_len))
7024 			rsm->soff -= (rsm->orig_m_len - rsm->m->m_len);
7025 		else
7026 			rsm->soff = 0;
7027 		rsm->orig_m_len = rsm->m->m_len;
7028 #ifdef INVARIANTS
7029 	} else if (rsm->m->m_len > rsm->orig_m_len) {
7030 		panic("rsm:%p m:%p m_len grew outside of t_space compensation",
7031 		      rsm, rsm->m);
7032 #endif
7033 	}
7034 }
7035 
7036 static void
7037 rack_setup_offset_for_rsm(struct tcp_rack *rack, struct rack_sendmap *src_rsm, struct rack_sendmap *rsm)
7038 {
7039 	struct mbuf *m;
7040 	uint32_t soff;
7041 
7042 	if (src_rsm->m &&
7043 	    ((src_rsm->orig_m_len != src_rsm->m->m_len) ||
7044 	     (M_TRAILINGROOM(src_rsm->m) != src_rsm->orig_t_space))) {
7045 		/* Fix up the orig_m_len and possibly the mbuf offset */
7046 		rack_adjust_orig_mlen(src_rsm);
7047 	}
7048 	m = src_rsm->m;
7049 	soff = src_rsm->soff + (src_rsm->r_end - src_rsm->r_start);
7050 	while (soff >= m->m_len) {
7051 		/* Move out past this mbuf */
7052 		soff -= m->m_len;
7053 		m = m->m_next;
7054 		KASSERT((m != NULL),
7055 			("rsm:%p nrsm:%p hit at soff:%u null m",
7056 			 src_rsm, rsm, soff));
7057 		if (m == NULL) {
7058 			/* This should *not* happen which is why there is a kassert */
7059 			src_rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd,
7060 					       (src_rsm->r_start - rack->rc_tp->snd_una),
7061 					       &src_rsm->soff);
7062 			src_rsm->orig_m_len = src_rsm->m->m_len;
7063 			src_rsm->orig_t_space = M_TRAILINGROOM(src_rsm->m);
7064 			rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd,
7065 					   (rsm->r_start - rack->rc_tp->snd_una),
7066 					   &rsm->soff);
7067 			rsm->orig_m_len = rsm->m->m_len;
7068 			rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
7069 			return;
7070 		}
7071 	}
7072 	rsm->m = m;
7073 	rsm->soff = soff;
7074 	rsm->orig_m_len = m->m_len;
7075 	rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
7076 }
7077 
7078 static __inline void
7079 rack_clone_rsm(struct tcp_rack *rack, struct rack_sendmap *nrsm,
7080 	       struct rack_sendmap *rsm, uint32_t start)
7081 {
7082 	int idx;
7083 
7084 	nrsm->r_start = start;
7085 	nrsm->r_end = rsm->r_end;
7086 	nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
7087 	nrsm->r_flags = rsm->r_flags;
7088 	nrsm->r_dupack = rsm->r_dupack;
7089 	nrsm->r_no_rtt_allowed = rsm->r_no_rtt_allowed;
7090 	nrsm->r_rtr_bytes = 0;
7091 	nrsm->r_fas = rsm->r_fas;
7092 	nrsm->r_bas = rsm->r_bas;
7093 	rsm->r_end = nrsm->r_start;
7094 	nrsm->r_just_ret = rsm->r_just_ret;
7095 	for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
7096 		nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
7097 	}
7098 	/* Now if we have SYN flag we keep it on the left edge */
7099 	if (nrsm->r_flags & RACK_HAS_SYN)
7100 		nrsm->r_flags &= ~RACK_HAS_SYN;
7101 	/* Now if we have a FIN flag we keep it on the right edge */
7102 	if (rsm->r_flags & RACK_HAS_FIN)
7103 		rsm->r_flags &= ~RACK_HAS_FIN;
7104 	/* Push bit must go to the right edge as well */
7105 	if (rsm->r_flags & RACK_HAD_PUSH)
7106 		rsm->r_flags &= ~RACK_HAD_PUSH;
7107 	/* Clone over the state of the hw_tls flag */
7108 	nrsm->r_hw_tls = rsm->r_hw_tls;
7109 	/*
7110 	 * Now we need to find nrsm's new location in the mbuf chain
7111 	 * we basically calculate a new offset, which is soff +
7112 	 * how much is left in original rsm. Then we walk out the mbuf
7113 	 * chain to find the righ position, it may be the same mbuf
7114 	 * or maybe not.
7115 	 */
7116 	KASSERT(((rsm->m != NULL) ||
7117 		 (rsm->r_flags & (RACK_HAS_SYN|RACK_HAS_FIN))),
7118 		("rsm:%p nrsm:%p rack:%p -- rsm->m is NULL?", rsm, nrsm, rack));
7119 	if (rsm->m)
7120 		rack_setup_offset_for_rsm(rack, rsm, nrsm);
7121 }
7122 
7123 static struct rack_sendmap *
7124 rack_merge_rsm(struct tcp_rack *rack,
7125 	       struct rack_sendmap *l_rsm,
7126 	       struct rack_sendmap *r_rsm)
7127 {
7128 	/*
7129 	 * We are merging two ack'd RSM's,
7130 	 * the l_rsm is on the left (lower seq
7131 	 * values) and the r_rsm is on the right
7132 	 * (higher seq value). The simplest way
7133 	 * to merge these is to move the right
7134 	 * one into the left. I don't think there
7135 	 * is any reason we need to try to find
7136 	 * the oldest (or last oldest retransmitted).
7137 	 */
7138 	rack_log_map_chg(rack->rc_tp, rack, NULL,
7139 			 l_rsm, r_rsm, MAP_MERGE, r_rsm->r_end, __LINE__);
7140 	l_rsm->r_end = r_rsm->r_end;
7141 	if (l_rsm->r_dupack < r_rsm->r_dupack)
7142 		l_rsm->r_dupack = r_rsm->r_dupack;
7143 	if (r_rsm->r_rtr_bytes)
7144 		l_rsm->r_rtr_bytes += r_rsm->r_rtr_bytes;
7145 	if (r_rsm->r_in_tmap) {
7146 		/* This really should not happen */
7147 		TAILQ_REMOVE(&rack->r_ctl.rc_tmap, r_rsm, r_tnext);
7148 		r_rsm->r_in_tmap = 0;
7149 	}
7150 
7151 	/* Now the flags */
7152 	if (r_rsm->r_flags & RACK_HAS_FIN)
7153 		l_rsm->r_flags |= RACK_HAS_FIN;
7154 	if (r_rsm->r_flags & RACK_TLP)
7155 		l_rsm->r_flags |= RACK_TLP;
7156 	if (r_rsm->r_flags & RACK_RWND_COLLAPSED)
7157 		l_rsm->r_flags |= RACK_RWND_COLLAPSED;
7158 	if ((r_rsm->r_flags & RACK_APP_LIMITED)  &&
7159 	    ((l_rsm->r_flags & RACK_APP_LIMITED) == 0)) {
7160 		/*
7161 		 * If both are app-limited then let the
7162 		 * free lower the count. If right is app
7163 		 * limited and left is not, transfer.
7164 		 */
7165 		l_rsm->r_flags |= RACK_APP_LIMITED;
7166 		r_rsm->r_flags &= ~RACK_APP_LIMITED;
7167 		if (r_rsm == rack->r_ctl.rc_first_appl)
7168 			rack->r_ctl.rc_first_appl = l_rsm;
7169 	}
7170 	tqhash_remove(rack->r_ctl.tqh, r_rsm, REMOVE_TYPE_MERGE);
7171 	/*
7172 	 * We keep the largest value, which is the newest
7173 	 * send. We do this in case a segment that is
7174 	 * joined together and not part of a GP estimate
7175 	 * later gets expanded into the GP estimate.
7176 	 *
7177 	 * We prohibit the merging of unlike kinds i.e.
7178 	 * all pieces that are in the GP estimate can be
7179 	 * merged and all pieces that are not in a GP estimate
7180 	 * can be merged, but not disimilar pieces. Combine
7181 	 * this with taking the highest here and we should
7182 	 * be ok unless of course the client reneges. Then
7183 	 * all bets are off.
7184 	 */
7185 	if(l_rsm->r_tim_lastsent[(l_rsm->r_rtr_cnt-1)] <
7186 	   r_rsm->r_tim_lastsent[(r_rsm->r_rtr_cnt-1)]) {
7187 		l_rsm->r_tim_lastsent[(l_rsm->r_rtr_cnt-1)] = r_rsm->r_tim_lastsent[(r_rsm->r_rtr_cnt-1)];
7188 	}
7189 	/*
7190 	 * When merging two RSM's we also need to consider the ack time and keep
7191 	 * newest. If the ack gets merged into a measurement then that is the
7192 	 * one we will want to be using.
7193 	 */
7194 	if(l_rsm->r_ack_arrival	 < r_rsm->r_ack_arrival)
7195 		l_rsm->r_ack_arrival = r_rsm->r_ack_arrival;
7196 
7197 	if ((r_rsm->r_limit_type == 0) && (l_rsm->r_limit_type != 0)) {
7198 		/* Transfer the split limit to the map we free */
7199 		r_rsm->r_limit_type = l_rsm->r_limit_type;
7200 		l_rsm->r_limit_type = 0;
7201 	}
7202 	rack_free(rack, r_rsm);
7203 	l_rsm->r_flags |= RACK_MERGED;
7204 	return (l_rsm);
7205 }
7206 
7207 /*
7208  * TLP Timer, here we simply setup what segment we want to
7209  * have the TLP expire on, the normal rack_output() will then
7210  * send it out.
7211  *
7212  * We return 1, saying don't proceed with rack_output only
7213  * when all timers have been stopped (destroyed PCB?).
7214  */
7215 static int
7216 rack_timeout_tlp(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t *doing_tlp)
7217 {
7218 	/*
7219 	 * Tail Loss Probe.
7220 	 */
7221 	struct rack_sendmap *rsm = NULL;
7222 	int insret __diagused;
7223 	struct socket *so = tptosocket(tp);
7224 	uint32_t amm;
7225 	uint32_t out, avail;
7226 	int collapsed_win = 0;
7227 
7228 	if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
7229 		/* Its not time yet */
7230 		return (0);
7231 	}
7232 	if (ctf_progress_timeout_check(tp, true)) {
7233 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
7234 		return (-ETIMEDOUT);	/* tcp_drop() */
7235 	}
7236 	/*
7237 	 * A TLP timer has expired. We have been idle for 2 rtts. So we now
7238 	 * need to figure out how to force a full MSS segment out.
7239 	 */
7240 	rack_log_to_event(rack, RACK_TO_FRM_TLP, NULL);
7241 	rack->r_ctl.retran_during_recovery = 0;
7242 	rack->r_ctl.dsack_byte_cnt = 0;
7243 	counter_u64_add(rack_tlp_tot, 1);
7244 	if (rack->r_state && (rack->r_state != tp->t_state))
7245 		rack_set_state(tp, rack);
7246 	avail = sbavail(&so->so_snd);
7247 	out = tp->snd_max - tp->snd_una;
7248 	if ((out > tp->snd_wnd) || rack->rc_has_collapsed) {
7249 		/* special case, we need a retransmission */
7250 		collapsed_win = 1;
7251 		goto need_retran;
7252 	}
7253 	if (rack->r_ctl.dsack_persist && (rack->r_ctl.rc_tlp_cnt_out >= 1)) {
7254 		rack->r_ctl.dsack_persist--;
7255 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
7256 			rack->r_ctl.num_dsack = 0;
7257 		}
7258 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
7259 	}
7260 	if ((tp->t_flags & TF_GPUTINPROG) &&
7261 	    (rack->r_ctl.rc_tlp_cnt_out == 1)) {
7262 		/*
7263 		 * If this is the second in a row
7264 		 * TLP and we are doing a measurement
7265 		 * its time to abandon the measurement.
7266 		 * Something is likely broken on
7267 		 * the clients network and measuring a
7268 		 * broken network does us no good.
7269 		 */
7270 		tp->t_flags &= ~TF_GPUTINPROG;
7271 		rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
7272 					   rack->r_ctl.rc_gp_srtt /*flex1*/,
7273 					   tp->gput_seq,
7274 					   0, 0, 18, __LINE__, NULL, 0);
7275 	}
7276 	/*
7277 	 * Check our send oldest always settings, and if
7278 	 * there is an oldest to send jump to the need_retran.
7279 	 */
7280 	if (rack_always_send_oldest && (TAILQ_EMPTY(&rack->r_ctl.rc_tmap) == 0))
7281 		goto need_retran;
7282 
7283 	if (avail > out) {
7284 		/* New data is available */
7285 		amm = avail - out;
7286 		if (amm > ctf_fixed_maxseg(tp)) {
7287 			amm = ctf_fixed_maxseg(tp);
7288 			if ((amm + out) > tp->snd_wnd) {
7289 				/* We are rwnd limited */
7290 				goto need_retran;
7291 			}
7292 		} else if (amm < ctf_fixed_maxseg(tp)) {
7293 			/* not enough to fill a MTU */
7294 			goto need_retran;
7295 		}
7296 		if (IN_FASTRECOVERY(tp->t_flags)) {
7297 			/* Unlikely */
7298 			if (rack->rack_no_prr == 0) {
7299 				if (out + amm <= tp->snd_wnd) {
7300 					rack->r_ctl.rc_prr_sndcnt = amm;
7301 					rack->r_ctl.rc_tlp_new_data = amm;
7302 					rack_log_to_prr(rack, 4, 0, __LINE__);
7303 				}
7304 			} else
7305 				goto need_retran;
7306 		} else {
7307 			/* Set the send-new override */
7308 			if (out + amm <= tp->snd_wnd)
7309 				rack->r_ctl.rc_tlp_new_data = amm;
7310 			else
7311 				goto need_retran;
7312 		}
7313 		rack->r_ctl.rc_tlpsend = NULL;
7314 		counter_u64_add(rack_tlp_newdata, 1);
7315 		goto send;
7316 	}
7317 need_retran:
7318 	/*
7319 	 * Ok we need to arrange the last un-acked segment to be re-sent, or
7320 	 * optionally the first un-acked segment.
7321 	 */
7322 	if (collapsed_win == 0) {
7323 		if (rack_always_send_oldest)
7324 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
7325 		else {
7326 			rsm = tqhash_max(rack->r_ctl.tqh);
7327 			if (rsm && (rsm->r_flags & (RACK_ACKED | RACK_HAS_FIN))) {
7328 				rsm = rack_find_high_nonack(rack, rsm);
7329 			}
7330 		}
7331 		if (rsm == NULL) {
7332 #ifdef TCP_BLACKBOX
7333 			tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
7334 #endif
7335 			goto out;
7336 		}
7337 	} else {
7338 		/*
7339 		 * We had a collapsed window, lets find
7340 		 * the point before the collapse.
7341 		 */
7342 		if (SEQ_GT((rack->r_ctl.last_collapse_point - 1), rack->rc_tp->snd_una))
7343 			rsm = tqhash_find(rack->r_ctl.tqh, (rack->r_ctl.last_collapse_point - 1));
7344 		else {
7345 			rsm = tqhash_min(rack->r_ctl.tqh);
7346 		}
7347 		if (rsm == NULL) {
7348 			/* Huh */
7349 			goto out;
7350 		}
7351 	}
7352 	if ((rsm->r_end - rsm->r_start) > ctf_fixed_maxseg(tp)) {
7353 		/*
7354 		 * We need to split this the last segment in two.
7355 		 */
7356 		struct rack_sendmap *nrsm;
7357 
7358 		nrsm = rack_alloc_full_limit(rack);
7359 		if (nrsm == NULL) {
7360 			/*
7361 			 * No memory to split, we will just exit and punt
7362 			 * off to the RXT timer.
7363 			 */
7364 			goto out;
7365 		}
7366 		rack_clone_rsm(rack, nrsm, rsm,
7367 			       (rsm->r_end - ctf_fixed_maxseg(tp)));
7368 		rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
7369 #ifndef INVARIANTS
7370 		(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
7371 #else
7372 		if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
7373 			panic("Insert in rb tree of %p fails ret:%d rack:%p rsm:%p",
7374 			      nrsm, insret, rack, rsm);
7375 		}
7376 #endif
7377 		if (rsm->r_in_tmap) {
7378 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7379 			nrsm->r_in_tmap = 1;
7380 		}
7381 		rsm = nrsm;
7382 	}
7383 	rack->r_ctl.rc_tlpsend = rsm;
7384 send:
7385 	/* Make sure output path knows we are doing a TLP */
7386 	*doing_tlp = 1;
7387 	rack->r_timer_override = 1;
7388 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
7389 	return (0);
7390 out:
7391 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
7392 	return (0);
7393 }
7394 
7395 /*
7396  * Delayed ack Timer, here we simply need to setup the
7397  * ACK_NOW flag and remove the DELACK flag. From there
7398  * the output routine will send the ack out.
7399  *
7400  * We only return 1, saying don't proceed, if all timers
7401  * are stopped (destroyed PCB?).
7402  */
7403 static int
7404 rack_timeout_delack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
7405 {
7406 
7407 	rack_log_to_event(rack, RACK_TO_FRM_DELACK, NULL);
7408 	tp->t_flags &= ~TF_DELACK;
7409 	tp->t_flags |= TF_ACKNOW;
7410 	KMOD_TCPSTAT_INC(tcps_delack);
7411 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
7412 	return (0);
7413 }
7414 
7415 /*
7416  * Persists timer, here we simply send the
7417  * same thing as a keepalive will.
7418  * the one byte send.
7419  *
7420  * We only return 1, saying don't proceed, if all timers
7421  * are stopped (destroyed PCB?).
7422  */
7423 static int
7424 rack_timeout_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
7425 {
7426 	struct tcptemp *t_template;
7427 	int32_t retval = 1;
7428 
7429 	if (rack->rc_in_persist == 0)
7430 		return (0);
7431 	if (ctf_progress_timeout_check(tp, false)) {
7432 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
7433 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
7434 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
7435 		return (-ETIMEDOUT);	/* tcp_drop() */
7436 	}
7437 	/*
7438 	 * Persistence timer into zero window. Force a byte to be output, if
7439 	 * possible.
7440 	 */
7441 	KMOD_TCPSTAT_INC(tcps_persisttimeo);
7442 	/*
7443 	 * Hack: if the peer is dead/unreachable, we do not time out if the
7444 	 * window is closed.  After a full backoff, drop the connection if
7445 	 * the idle time (no responses to probes) reaches the maximum
7446 	 * backoff that we would use if retransmitting.
7447 	 */
7448 	if (tp->t_rxtshift == TCP_MAXRXTSHIFT &&
7449 	    (ticks - tp->t_rcvtime >= tcp_maxpersistidle ||
7450 	     TICKS_2_USEC(ticks - tp->t_rcvtime) >= RACK_REXMTVAL(tp) * tcp_totbackoff)) {
7451 		KMOD_TCPSTAT_INC(tcps_persistdrop);
7452 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
7453 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
7454 		retval = -ETIMEDOUT;	/* tcp_drop() */
7455 		goto out;
7456 	}
7457 	if ((sbavail(&rack->rc_inp->inp_socket->so_snd) == 0) &&
7458 	    tp->snd_una == tp->snd_max)
7459 		rack_exit_persist(tp, rack, cts);
7460 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_PERSIT;
7461 	/*
7462 	 * If the user has closed the socket then drop a persisting
7463 	 * connection after a much reduced timeout.
7464 	 */
7465 	if (tp->t_state > TCPS_CLOSE_WAIT &&
7466 	    (ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) {
7467 		KMOD_TCPSTAT_INC(tcps_persistdrop);
7468 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
7469 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
7470 		retval = -ETIMEDOUT;	/* tcp_drop() */
7471 		goto out;
7472 	}
7473 	t_template = tcpip_maketemplate(rack->rc_inp);
7474 	if (t_template) {
7475 		/* only set it if we were answered */
7476 		if (rack->forced_ack == 0) {
7477 			rack->forced_ack = 1;
7478 			rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
7479 		} else {
7480 			rack->probe_not_answered = 1;
7481 			counter_u64_add(rack_persists_loss, 1);
7482 			rack->r_ctl.persist_lost_ends++;
7483 		}
7484 		counter_u64_add(rack_persists_sends, 1);
7485 		counter_u64_add(rack_out_size[TCP_MSS_ACCT_PERSIST], 1);
7486 		tcp_respond(tp, t_template->tt_ipgen,
7487 			    &t_template->tt_t, (struct mbuf *)NULL,
7488 			    tp->rcv_nxt, tp->snd_una - 1, 0);
7489 		/* This sends an ack */
7490 		if (tp->t_flags & TF_DELACK)
7491 			tp->t_flags &= ~TF_DELACK;
7492 		free(t_template, M_TEMP);
7493 	}
7494 	if (tp->t_rxtshift < TCP_MAXRXTSHIFT)
7495 		tp->t_rxtshift++;
7496 out:
7497 	rack_log_to_event(rack, RACK_TO_FRM_PERSIST, NULL);
7498 	rack_start_hpts_timer(rack, tp, cts,
7499 			      0, 0, 0);
7500 	return (retval);
7501 }
7502 
7503 /*
7504  * If a keepalive goes off, we had no other timers
7505  * happening. We always return 1 here since this
7506  * routine either drops the connection or sends
7507  * out a segment with respond.
7508  */
7509 static int
7510 rack_timeout_keepalive(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
7511 {
7512 	struct tcptemp *t_template;
7513 	struct inpcb *inp = tptoinpcb(tp);
7514 
7515 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_KEEP;
7516 	rack_log_to_event(rack, RACK_TO_FRM_KEEP, NULL);
7517 	/*
7518 	 * Keep-alive timer went off; send something or drop connection if
7519 	 * idle for too long.
7520 	 */
7521 	KMOD_TCPSTAT_INC(tcps_keeptimeo);
7522 	if (tp->t_state < TCPS_ESTABLISHED)
7523 		goto dropit;
7524 	if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
7525 	    tp->t_state <= TCPS_CLOSING) {
7526 		if (ticks - tp->t_rcvtime >= TP_KEEPIDLE(tp) + TP_MAXIDLE(tp))
7527 			goto dropit;
7528 		/*
7529 		 * Send a packet designed to force a response if the peer is
7530 		 * up and reachable: either an ACK if the connection is
7531 		 * still alive, or an RST if the peer has closed the
7532 		 * connection due to timeout or reboot. Using sequence
7533 		 * number tp->snd_una-1 causes the transmitted zero-length
7534 		 * segment to lie outside the receive window; by the
7535 		 * protocol spec, this requires the correspondent TCP to
7536 		 * respond.
7537 		 */
7538 		KMOD_TCPSTAT_INC(tcps_keepprobe);
7539 		t_template = tcpip_maketemplate(inp);
7540 		if (t_template) {
7541 			if (rack->forced_ack == 0) {
7542 				rack->forced_ack = 1;
7543 				rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
7544 			} else {
7545 				rack->probe_not_answered = 1;
7546 			}
7547 			tcp_respond(tp, t_template->tt_ipgen,
7548 			    &t_template->tt_t, (struct mbuf *)NULL,
7549 			    tp->rcv_nxt, tp->snd_una - 1, 0);
7550 			free(t_template, M_TEMP);
7551 		}
7552 	}
7553 	rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
7554 	return (1);
7555 dropit:
7556 	KMOD_TCPSTAT_INC(tcps_keepdrops);
7557 	tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
7558 	return (-ETIMEDOUT);	/* tcp_drop() */
7559 }
7560 
7561 /*
7562  * Retransmit helper function, clear up all the ack
7563  * flags and take care of important book keeping.
7564  */
7565 static void
7566 rack_remxt_tmr(struct tcpcb *tp)
7567 {
7568 	/*
7569 	 * The retransmit timer went off, all sack'd blocks must be
7570 	 * un-acked.
7571 	 */
7572 	struct rack_sendmap *rsm, *trsm = NULL;
7573 	struct tcp_rack *rack;
7574 
7575 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7576 	rack_timer_cancel(tp, rack, tcp_get_usecs(NULL), __LINE__);
7577 	rack_log_to_event(rack, RACK_TO_FRM_TMR, NULL);
7578 	if (rack->r_state && (rack->r_state != tp->t_state))
7579 		rack_set_state(tp, rack);
7580 	/*
7581 	 * Ideally we would like to be able to
7582 	 * mark SACK-PASS on anything not acked here.
7583 	 *
7584 	 * However, if we do that we would burst out
7585 	 * all that data 1ms apart. This would be unwise,
7586 	 * so for now we will just let the normal rxt timer
7587 	 * and tlp timer take care of it.
7588 	 *
7589 	 * Also we really need to stick them back in sequence
7590 	 * order. This way we send in the proper order and any
7591 	 * sacks that come floating in will "re-ack" the data.
7592 	 * To do this we zap the tmap with an INIT and then
7593 	 * walk through and place every rsm in the RB tree
7594 	 * back in its seq ordered place.
7595 	 */
7596 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
7597 
7598 	TQHASH_FOREACH(rsm, rack->r_ctl.tqh)  {
7599 		rsm->r_dupack = 0;
7600 		if (rack_verbose_logging)
7601 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
7602 		/* We must re-add it back to the tlist */
7603 		if (trsm == NULL) {
7604 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7605 		} else {
7606 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, trsm, rsm, r_tnext);
7607 		}
7608 		rsm->r_in_tmap = 1;
7609 		trsm = rsm;
7610 		if (rsm->r_flags & RACK_ACKED)
7611 			rsm->r_flags |= RACK_WAS_ACKED;
7612 		rsm->r_flags &= ~(RACK_ACKED | RACK_SACK_PASSED | RACK_WAS_SACKPASS | RACK_RWND_COLLAPSED);
7613 		rsm->r_flags |= RACK_MUST_RXT;
7614 	}
7615 	/* Clear the count (we just un-acked them) */
7616 	rack->r_ctl.rc_last_timeout_snduna = tp->snd_una;
7617 	rack->r_ctl.rc_sacked = 0;
7618 	rack->r_ctl.rc_sacklast = NULL;
7619 	rack->r_ctl.rc_agg_delayed = 0;
7620 	rack->r_early = 0;
7621 	rack->r_ctl.rc_agg_early = 0;
7622 	rack->r_late = 0;
7623 	/* Clear the tlp rtx mark */
7624 	rack->r_ctl.rc_resend = tqhash_min(rack->r_ctl.tqh);
7625 	if (rack->r_ctl.rc_resend != NULL)
7626 		rack->r_ctl.rc_resend->r_flags |= RACK_TO_REXT;
7627 	rack->r_ctl.rc_prr_sndcnt = 0;
7628 	rack_log_to_prr(rack, 6, 0, __LINE__);
7629 	rack->r_timer_override = 1;
7630 	if ((((tp->t_flags & TF_SACK_PERMIT) == 0)
7631 #ifdef TCP_SAD_DETECTION
7632 	    || (rack->sack_attack_disable != 0)
7633 #endif
7634 		    ) && ((tp->t_flags & TF_SENTFIN) == 0)) {
7635 		/*
7636 		 * For non-sack customers new data
7637 		 * needs to go out as retransmits until
7638 		 * we retransmit up to snd_max.
7639 		 */
7640 		rack->r_must_retran = 1;
7641 		rack->r_ctl.rc_out_at_rto = ctf_flight_size(rack->rc_tp,
7642 						rack->r_ctl.rc_sacked);
7643 	}
7644 	rack->r_ctl.rc_snd_max_at_rto = tp->snd_max;
7645 }
7646 
7647 static void
7648 rack_convert_rtts(struct tcpcb *tp)
7649 {
7650 	tcp_change_time_units(tp, TCP_TMR_GRANULARITY_USEC);
7651 	tp->t_rxtcur = RACK_REXMTVAL(tp);
7652 	if (TCPS_HAVEESTABLISHED(tp->t_state)) {
7653 		tp->t_rxtcur += TICKS_2_USEC(tcp_rexmit_slop);
7654 	}
7655 	if (tp->t_rxtcur > rack_rto_max) {
7656 		tp->t_rxtcur = rack_rto_max;
7657 	}
7658 }
7659 
7660 static void
7661 rack_cc_conn_init(struct tcpcb *tp)
7662 {
7663 	struct tcp_rack *rack;
7664 	uint32_t srtt;
7665 
7666 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7667 	srtt = tp->t_srtt;
7668 	cc_conn_init(tp);
7669 	/*
7670 	 * Now convert to rack's internal format,
7671 	 * if required.
7672 	 */
7673 	if ((srtt == 0) && (tp->t_srtt != 0))
7674 		rack_convert_rtts(tp);
7675 	/*
7676 	 * We want a chance to stay in slowstart as
7677 	 * we create a connection. TCP spec says that
7678 	 * initially ssthresh is infinite. For our
7679 	 * purposes that is the snd_wnd.
7680 	 */
7681 	if (tp->snd_ssthresh < tp->snd_wnd) {
7682 		tp->snd_ssthresh = tp->snd_wnd;
7683 	}
7684 	/*
7685 	 * We also want to assure a IW worth of
7686 	 * data can get inflight.
7687 	 */
7688 	if (rc_init_window(rack) < tp->snd_cwnd)
7689 		tp->snd_cwnd = rc_init_window(rack);
7690 }
7691 
7692 /*
7693  * Re-transmit timeout! If we drop the PCB we will return 1, otherwise
7694  * we will setup to retransmit the lowest seq number outstanding.
7695  */
7696 static int
7697 rack_timeout_rxt(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
7698 {
7699 	struct inpcb *inp = tptoinpcb(tp);
7700 	int32_t rexmt;
7701 	int32_t retval = 0;
7702 	bool isipv6;
7703 
7704 	if ((tp->t_flags & TF_GPUTINPROG) &&
7705 	    (tp->t_rxtshift)) {
7706 		/*
7707 		 * We have had a second timeout
7708 		 * measurements on successive rxt's are not profitable.
7709 		 * It is unlikely to be of any use (the network is
7710 		 * broken or the client went away).
7711 		 */
7712 		tp->t_flags &= ~TF_GPUTINPROG;
7713 		rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
7714 					   rack->r_ctl.rc_gp_srtt /*flex1*/,
7715 					   tp->gput_seq,
7716 					   0, 0, 18, __LINE__, NULL, 0);
7717 	}
7718 	if (ctf_progress_timeout_check(tp, false)) {
7719 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
7720 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
7721 		return (-ETIMEDOUT);	/* tcp_drop() */
7722 	}
7723 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RXT;
7724 	rack->r_ctl.retran_during_recovery = 0;
7725 	rack->rc_ack_required = 1;
7726 	rack->r_ctl.dsack_byte_cnt = 0;
7727 	if (IN_FASTRECOVERY(tp->t_flags))
7728 		tp->t_flags |= TF_WASFRECOVERY;
7729 	else
7730 		tp->t_flags &= ~TF_WASFRECOVERY;
7731 	if (IN_CONGRECOVERY(tp->t_flags))
7732 		tp->t_flags |= TF_WASCRECOVERY;
7733 	else
7734 		tp->t_flags &= ~TF_WASCRECOVERY;
7735 	if (TCPS_HAVEESTABLISHED(tp->t_state) &&
7736 	    (tp->snd_una == tp->snd_max)) {
7737 		/* Nothing outstanding .. nothing to do */
7738 		return (0);
7739 	}
7740 	if (rack->r_ctl.dsack_persist) {
7741 		rack->r_ctl.dsack_persist--;
7742 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
7743 			rack->r_ctl.num_dsack = 0;
7744 		}
7745 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
7746 	}
7747 	/*
7748 	 * Rack can only run one timer  at a time, so we cannot
7749 	 * run a KEEPINIT (gating SYN sending) and a retransmit
7750 	 * timer for the SYN. So if we are in a front state and
7751 	 * have a KEEPINIT timer we need to check the first transmit
7752 	 * against now to see if we have exceeded the KEEPINIT time
7753 	 * (if one is set).
7754 	 */
7755 	if ((TCPS_HAVEESTABLISHED(tp->t_state) == 0) &&
7756 	    (TP_KEEPINIT(tp) != 0)) {
7757 		struct rack_sendmap *rsm;
7758 
7759 		rsm = tqhash_min(rack->r_ctl.tqh);
7760 		if (rsm) {
7761 			/* Ok we have something outstanding to test keepinit with */
7762 			if ((TSTMP_GT(cts, (uint32_t)rsm->r_tim_lastsent[0])) &&
7763 			    ((cts - (uint32_t)rsm->r_tim_lastsent[0]) >= TICKS_2_USEC(TP_KEEPINIT(tp)))) {
7764 				/* We have exceeded the KEEPINIT time */
7765 				tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
7766 				goto drop_it;
7767 			}
7768 		}
7769 	}
7770 	/*
7771 	 * Retransmission timer went off.  Message has not been acked within
7772 	 * retransmit interval.  Back off to a longer retransmit interval
7773 	 * and retransmit one segment.
7774 	 */
7775 	rack_remxt_tmr(tp);
7776 	if ((rack->r_ctl.rc_resend == NULL) ||
7777 	    ((rack->r_ctl.rc_resend->r_flags & RACK_RWND_COLLAPSED) == 0)) {
7778 		/*
7779 		 * If the rwnd collapsed on
7780 		 * the one we are retransmitting
7781 		 * it does not count against the
7782 		 * rxt count.
7783 		 */
7784 		tp->t_rxtshift++;
7785 	}
7786 	if (tp->t_rxtshift > TCP_MAXRXTSHIFT) {
7787 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
7788 drop_it:
7789 		tp->t_rxtshift = TCP_MAXRXTSHIFT;
7790 		KMOD_TCPSTAT_INC(tcps_timeoutdrop);
7791 		/* XXXGL: previously t_softerror was casted to uint16_t */
7792 		MPASS(tp->t_softerror >= 0);
7793 		retval = tp->t_softerror ? -tp->t_softerror : -ETIMEDOUT;
7794 		goto out;	/* tcp_drop() */
7795 	}
7796 	if (tp->t_state == TCPS_SYN_SENT) {
7797 		/*
7798 		 * If the SYN was retransmitted, indicate CWND to be limited
7799 		 * to 1 segment in cc_conn_init().
7800 		 */
7801 		tp->snd_cwnd = 1;
7802 	} else if (tp->t_rxtshift == 1) {
7803 		/*
7804 		 * first retransmit; record ssthresh and cwnd so they can be
7805 		 * recovered if this turns out to be a "bad" retransmit. A
7806 		 * retransmit is considered "bad" if an ACK for this segment
7807 		 * is received within RTT/2 interval; the assumption here is
7808 		 * that the ACK was already in flight.  See "On Estimating
7809 		 * End-to-End Network Path Properties" by Allman and Paxson
7810 		 * for more details.
7811 		 */
7812 		tp->snd_cwnd_prev = tp->snd_cwnd;
7813 		tp->snd_ssthresh_prev = tp->snd_ssthresh;
7814 		tp->snd_recover_prev = tp->snd_recover;
7815 		tp->t_badrxtwin = ticks + (USEC_2_TICKS(tp->t_srtt)/2);
7816 		tp->t_flags |= TF_PREVVALID;
7817 	} else if ((tp->t_flags & TF_RCVD_TSTMP) == 0)
7818 		tp->t_flags &= ~TF_PREVVALID;
7819 	KMOD_TCPSTAT_INC(tcps_rexmttimeo);
7820 	if ((tp->t_state == TCPS_SYN_SENT) ||
7821 	    (tp->t_state == TCPS_SYN_RECEIVED))
7822 		rexmt = RACK_INITIAL_RTO * tcp_backoff[tp->t_rxtshift];
7823 	else
7824 		rexmt = max(rack_rto_min, (tp->t_srtt + (tp->t_rttvar << 2))) * tcp_backoff[tp->t_rxtshift];
7825 
7826 	RACK_TCPT_RANGESET(tp->t_rxtcur, rexmt,
7827 	   max(rack_rto_min, rexmt), rack_rto_max, rack->r_ctl.timer_slop);
7828 	/*
7829 	 * We enter the path for PLMTUD if connection is established or, if
7830 	 * connection is FIN_WAIT_1 status, reason for the last is that if
7831 	 * amount of data we send is very small, we could send it in couple
7832 	 * of packets and process straight to FIN. In that case we won't
7833 	 * catch ESTABLISHED state.
7834 	 */
7835 #ifdef INET6
7836 	isipv6 = (inp->inp_vflag & INP_IPV6) ? true : false;
7837 #else
7838 	isipv6 = false;
7839 #endif
7840 	if (((V_tcp_pmtud_blackhole_detect == 1) ||
7841 	    (V_tcp_pmtud_blackhole_detect == 2 && !isipv6) ||
7842 	    (V_tcp_pmtud_blackhole_detect == 3 && isipv6)) &&
7843 	    ((tp->t_state == TCPS_ESTABLISHED) ||
7844 	    (tp->t_state == TCPS_FIN_WAIT_1))) {
7845 		/*
7846 		 * Idea here is that at each stage of mtu probe (usually,
7847 		 * 1448 -> 1188 -> 524) should be given 2 chances to recover
7848 		 * before further clamping down. 'tp->t_rxtshift % 2 == 0'
7849 		 * should take care of that.
7850 		 */
7851 		if (((tp->t_flags2 & (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) ==
7852 		    (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) &&
7853 		    (tp->t_rxtshift >= 2 && tp->t_rxtshift < 6 &&
7854 		    tp->t_rxtshift % 2 == 0)) {
7855 			/*
7856 			 * Enter Path MTU Black-hole Detection mechanism: -
7857 			 * Disable Path MTU Discovery (IP "DF" bit). -
7858 			 * Reduce MTU to lower value than what we negotiated
7859 			 * with peer.
7860 			 */
7861 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) == 0) {
7862 				/* Record that we may have found a black hole. */
7863 				tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE;
7864 				/* Keep track of previous MSS. */
7865 				tp->t_pmtud_saved_maxseg = tp->t_maxseg;
7866 			}
7867 
7868 			/*
7869 			 * Reduce the MSS to blackhole value or to the
7870 			 * default in an attempt to retransmit.
7871 			 */
7872 #ifdef INET6
7873 			if (isipv6 &&
7874 			    tp->t_maxseg > V_tcp_v6pmtud_blackhole_mss) {
7875 				/* Use the sysctl tuneable blackhole MSS. */
7876 				tp->t_maxseg = V_tcp_v6pmtud_blackhole_mss;
7877 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
7878 			} else if (isipv6) {
7879 				/* Use the default MSS. */
7880 				tp->t_maxseg = V_tcp_v6mssdflt;
7881 				/*
7882 				 * Disable Path MTU Discovery when we switch
7883 				 * to minmss.
7884 				 */
7885 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
7886 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
7887 			}
7888 #endif
7889 #if defined(INET6) && defined(INET)
7890 			else
7891 #endif
7892 #ifdef INET
7893 			if (tp->t_maxseg > V_tcp_pmtud_blackhole_mss) {
7894 				/* Use the sysctl tuneable blackhole MSS. */
7895 				tp->t_maxseg = V_tcp_pmtud_blackhole_mss;
7896 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
7897 			} else {
7898 				/* Use the default MSS. */
7899 				tp->t_maxseg = V_tcp_mssdflt;
7900 				/*
7901 				 * Disable Path MTU Discovery when we switch
7902 				 * to minmss.
7903 				 */
7904 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
7905 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
7906 			}
7907 #endif
7908 		} else {
7909 			/*
7910 			 * If further retransmissions are still unsuccessful
7911 			 * with a lowered MTU, maybe this isn't a blackhole
7912 			 * and we restore the previous MSS and blackhole
7913 			 * detection flags. The limit '6' is determined by
7914 			 * giving each probe stage (1448, 1188, 524) 2
7915 			 * chances to recover.
7916 			 */
7917 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) &&
7918 			    (tp->t_rxtshift >= 6)) {
7919 				tp->t_flags2 |= TF2_PLPMTU_PMTUD;
7920 				tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE;
7921 				tp->t_maxseg = tp->t_pmtud_saved_maxseg;
7922 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_failed);
7923 			}
7924 		}
7925 	}
7926 	/*
7927 	 * Disable RFC1323 and SACK if we haven't got any response to
7928 	 * our third SYN to work-around some broken terminal servers
7929 	 * (most of which have hopefully been retired) that have bad VJ
7930 	 * header compression code which trashes TCP segments containing
7931 	 * unknown-to-them TCP options.
7932 	 */
7933 	if (tcp_rexmit_drop_options && (tp->t_state == TCPS_SYN_SENT) &&
7934 	    (tp->t_rxtshift == 3))
7935 		tp->t_flags &= ~(TF_REQ_SCALE|TF_REQ_TSTMP|TF_SACK_PERMIT);
7936 	/*
7937 	 * If we backed off this far, our srtt estimate is probably bogus.
7938 	 * Clobber it so we'll take the next rtt measurement as our srtt;
7939 	 * move the current srtt into rttvar to keep the current retransmit
7940 	 * times until then.
7941 	 */
7942 	if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
7943 #ifdef INET6
7944 		if ((inp->inp_vflag & INP_IPV6) != 0)
7945 			in6_losing(inp);
7946 		else
7947 #endif
7948 			in_losing(inp);
7949 		tp->t_rttvar += tp->t_srtt;
7950 		tp->t_srtt = 0;
7951 	}
7952 	sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
7953 	tp->snd_recover = tp->snd_max;
7954 	tp->t_flags |= TF_ACKNOW;
7955 	tp->t_rtttime = 0;
7956 	rack_cong_signal(tp, CC_RTO, tp->snd_una, __LINE__);
7957 out:
7958 	return (retval);
7959 }
7960 
7961 static int
7962 rack_process_timers(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t hpts_calling, uint8_t *doing_tlp)
7963 {
7964 	int32_t ret = 0;
7965 	int32_t timers = (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK);
7966 
7967 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
7968 	    (tp->t_flags & TF_GPUTINPROG)) {
7969 		/*
7970 		 * We have a goodput in progress
7971 		 * and we have entered a late state.
7972 		 * Do we have enough data in the sb
7973 		 * to handle the GPUT request?
7974 		 */
7975 		uint32_t bytes;
7976 
7977 		bytes = tp->gput_ack - tp->gput_seq;
7978 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
7979 			bytes += tp->gput_seq - tp->snd_una;
7980 		if (bytes > sbavail(&tptosocket(tp)->so_snd)) {
7981 			/*
7982 			 * There are not enough bytes in the socket
7983 			 * buffer that have been sent to cover this
7984 			 * measurement. Cancel it.
7985 			 */
7986 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
7987 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
7988 						   tp->gput_seq,
7989 						   0, 0, 18, __LINE__, NULL, 0);
7990 			tp->t_flags &= ~TF_GPUTINPROG;
7991 		}
7992 	}
7993 	if (timers == 0) {
7994 		return (0);
7995 	}
7996 	if (tp->t_state == TCPS_LISTEN) {
7997 		/* no timers on listen sockets */
7998 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)
7999 			return (0);
8000 		return (1);
8001 	}
8002 	if ((timers & PACE_TMR_RACK) &&
8003 	    rack->rc_on_min_to) {
8004 		/*
8005 		 * For the rack timer when we
8006 		 * are on a min-timeout (which means rrr_conf = 3)
8007 		 * we don't want to check the timer. It may
8008 		 * be going off for a pace and thats ok we
8009 		 * want to send the retransmit (if its ready).
8010 		 *
8011 		 * If its on a normal rack timer (non-min) then
8012 		 * we will check if its expired.
8013 		 */
8014 		goto skip_time_check;
8015 	}
8016 	if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
8017 		uint32_t left;
8018 
8019 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
8020 			ret = -1;
8021 			rack_log_to_processing(rack, cts, ret, 0);
8022 			return (0);
8023 		}
8024 		if (hpts_calling == 0) {
8025 			/*
8026 			 * A user send or queued mbuf (sack) has called us? We
8027 			 * return 0 and let the pacing guards
8028 			 * deal with it if they should or
8029 			 * should not cause a send.
8030 			 */
8031 			ret = -2;
8032 			rack_log_to_processing(rack, cts, ret, 0);
8033 			return (0);
8034 		}
8035 		/*
8036 		 * Ok our timer went off early and we are not paced false
8037 		 * alarm, go back to sleep. We make sure we don't have
8038 		 * no-sack wakeup on since we no longer have a PKT_OUTPUT
8039 		 * flag in place.
8040 		 */
8041 		rack->rc_tp->t_flags2 &= ~TF2_DONT_SACK_QUEUE;
8042 		ret = -3;
8043 		left = rack->r_ctl.rc_timer_exp - cts;
8044 		tcp_hpts_insert(tp, HPTS_MS_TO_SLOTS(left));
8045 		rack_log_to_processing(rack, cts, ret, left);
8046 		return (1);
8047 	}
8048 skip_time_check:
8049 	rack->rc_tmr_stopped = 0;
8050 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_MASK;
8051 	if (timers & PACE_TMR_DELACK) {
8052 		ret = rack_timeout_delack(tp, rack, cts);
8053 	} else if (timers & PACE_TMR_RACK) {
8054 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
8055 		rack->r_fast_output = 0;
8056 		ret = rack_timeout_rack(tp, rack, cts);
8057 	} else if (timers & PACE_TMR_TLP) {
8058 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
8059 		ret = rack_timeout_tlp(tp, rack, cts, doing_tlp);
8060 	} else if (timers & PACE_TMR_RXT) {
8061 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
8062 		rack->r_fast_output = 0;
8063 		ret = rack_timeout_rxt(tp, rack, cts);
8064 	} else if (timers & PACE_TMR_PERSIT) {
8065 		ret = rack_timeout_persist(tp, rack, cts);
8066 	} else if (timers & PACE_TMR_KEEP) {
8067 		ret = rack_timeout_keepalive(tp, rack, cts);
8068 	}
8069 	rack_log_to_processing(rack, cts, ret, timers);
8070 	return (ret);
8071 }
8072 
8073 static void
8074 rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line)
8075 {
8076 	struct timeval tv;
8077 	uint32_t us_cts, flags_on_entry;
8078 	uint8_t hpts_removed = 0;
8079 
8080 	flags_on_entry = rack->r_ctl.rc_hpts_flags;
8081 	us_cts = tcp_get_usecs(&tv);
8082 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
8083 	    ((TSTMP_GEQ(us_cts, rack->r_ctl.rc_last_output_to)) ||
8084 	     ((tp->snd_max - tp->snd_una) == 0))) {
8085 		tcp_hpts_remove(rack->rc_tp);
8086 		hpts_removed = 1;
8087 		/* If we were not delayed cancel out the flag. */
8088 		if ((tp->snd_max - tp->snd_una) == 0)
8089 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
8090 		rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
8091 	}
8092 	if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
8093 		rack->rc_tmr_stopped = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
8094 		if (tcp_in_hpts(rack->rc_tp) &&
8095 		    ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)) {
8096 			/*
8097 			 * Canceling timer's when we have no output being
8098 			 * paced. We also must remove ourselves from the
8099 			 * hpts.
8100 			 */
8101 			tcp_hpts_remove(rack->rc_tp);
8102 			hpts_removed = 1;
8103 		}
8104 		rack->r_ctl.rc_hpts_flags &= ~(PACE_TMR_MASK);
8105 	}
8106 	if (hpts_removed == 0)
8107 		rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
8108 }
8109 
8110 static int
8111 rack_stopall(struct tcpcb *tp)
8112 {
8113 	struct tcp_rack *rack;
8114 	rack = (struct tcp_rack *)tp->t_fb_ptr;
8115 	rack->t_timers_stopped = 1;
8116 	return (0);
8117 }
8118 
8119 static void
8120 rack_stop_all_timers(struct tcpcb *tp, struct tcp_rack *rack)
8121 {
8122 	/*
8123 	 * Assure no timers are running.
8124 	 */
8125 	if (tcp_timer_active(tp, TT_PERSIST)) {
8126 		/* We enter in persists, set the flag appropriately */
8127 		rack->rc_in_persist = 1;
8128 	}
8129 	if (tcp_in_hpts(rack->rc_tp)) {
8130 		tcp_hpts_remove(rack->rc_tp);
8131 	}
8132 }
8133 
8134 static void
8135 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
8136     struct rack_sendmap *rsm, uint64_t ts, uint16_t add_flag, int segsiz)
8137 {
8138 	int32_t idx;
8139 
8140 	rsm->r_rtr_cnt++;
8141 	rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
8142 	rsm->r_dupack = 0;
8143 	if (rsm->r_rtr_cnt > RACK_NUM_OF_RETRANS) {
8144 		rsm->r_rtr_cnt = RACK_NUM_OF_RETRANS;
8145 		rsm->r_flags |= RACK_OVERMAX;
8146 	}
8147 	if ((rsm->r_rtr_cnt > 1) && ((rsm->r_flags & RACK_TLP) == 0)) {
8148 		rack->r_ctl.rc_holes_rxt += (rsm->r_end - rsm->r_start);
8149 		rsm->r_rtr_bytes += (rsm->r_end - rsm->r_start);
8150 	}
8151 	idx = rsm->r_rtr_cnt - 1;
8152 	rsm->r_tim_lastsent[idx] = ts;
8153 	/*
8154 	 * Here we don't add in the len of send, since its already
8155 	 * in snduna <->snd_max.
8156 	 */
8157 	rsm->r_fas = ctf_flight_size(rack->rc_tp,
8158 				     rack->r_ctl.rc_sacked);
8159 	if (rsm->r_flags & RACK_ACKED) {
8160 		/* Problably MTU discovery messing with us */
8161 		rsm->r_flags &= ~RACK_ACKED;
8162 		rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
8163 	}
8164 	if (rsm->r_in_tmap) {
8165 		TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8166 		rsm->r_in_tmap = 0;
8167 	}
8168 	/* Lets make sure it really is in or not the GP window */
8169 	rack_mark_in_gp_win(tp, rsm);
8170 	TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8171 	rsm->r_in_tmap = 1;
8172 	rsm->r_bas = (uint8_t)(((rsm->r_end - rsm->r_start) + segsiz - 1) / segsiz);
8173 	/* Take off the must retransmit flag, if its on */
8174 	if (rsm->r_flags & RACK_MUST_RXT) {
8175 		if (rack->r_must_retran)
8176 			rack->r_ctl.rc_out_at_rto -= (rsm->r_end - rsm->r_start);
8177 		if (SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) {
8178 			/*
8179 			 * We have retransmitted all we need. Clear
8180 			 * any must retransmit flags.
8181 			 */
8182 			rack->r_must_retran = 0;
8183 			rack->r_ctl.rc_out_at_rto = 0;
8184 		}
8185 		rsm->r_flags &= ~RACK_MUST_RXT;
8186 	}
8187 	/* Remove any collapsed flag */
8188 	rsm->r_flags &= ~RACK_RWND_COLLAPSED;
8189 	if (rsm->r_flags & RACK_SACK_PASSED) {
8190 		/* We have retransmitted due to the SACK pass */
8191 		rsm->r_flags &= ~RACK_SACK_PASSED;
8192 		rsm->r_flags |= RACK_WAS_SACKPASS;
8193 	}
8194 }
8195 
8196 static uint32_t
8197 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
8198     struct rack_sendmap *rsm, uint64_t ts, int32_t *lenp, uint16_t add_flag, int segsiz)
8199 {
8200 	/*
8201 	 * We (re-)transmitted starting at rsm->r_start for some length
8202 	 * (possibly less than r_end.
8203 	 */
8204 	struct rack_sendmap *nrsm;
8205 	int insret __diagused;
8206 	uint32_t c_end;
8207 	int32_t len;
8208 
8209 	len = *lenp;
8210 	c_end = rsm->r_start + len;
8211 	if (SEQ_GEQ(c_end, rsm->r_end)) {
8212 		/*
8213 		 * We retransmitted the whole piece or more than the whole
8214 		 * slopping into the next rsm.
8215 		 */
8216 		rack_update_rsm(tp, rack, rsm, ts, add_flag, segsiz);
8217 		if (c_end == rsm->r_end) {
8218 			*lenp = 0;
8219 			return (0);
8220 		} else {
8221 			int32_t act_len;
8222 
8223 			/* Hangs over the end return whats left */
8224 			act_len = rsm->r_end - rsm->r_start;
8225 			*lenp = (len - act_len);
8226 			return (rsm->r_end);
8227 		}
8228 		/* We don't get out of this block. */
8229 	}
8230 	/*
8231 	 * Here we retransmitted less than the whole thing which means we
8232 	 * have to split this into what was transmitted and what was not.
8233 	 */
8234 	nrsm = rack_alloc_full_limit(rack);
8235 	if (nrsm == NULL) {
8236 		/*
8237 		 * We can't get memory, so lets not proceed.
8238 		 */
8239 		*lenp = 0;
8240 		return (0);
8241 	}
8242 	/*
8243 	 * So here we are going to take the original rsm and make it what we
8244 	 * retransmitted. nrsm will be the tail portion we did not
8245 	 * retransmit. For example say the chunk was 1, 11 (10 bytes). And
8246 	 * we retransmitted 5 bytes i.e. 1, 5. The original piece shrinks to
8247 	 * 1, 6 and the new piece will be 6, 11.
8248 	 */
8249 	rack_clone_rsm(rack, nrsm, rsm, c_end);
8250 	nrsm->r_dupack = 0;
8251 	rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
8252 #ifndef INVARIANTS
8253 	(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
8254 #else
8255 	if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
8256 		panic("Insert in rb tree of %p fails ret:%d rack:%p rsm:%p",
8257 		      nrsm, insret, rack, rsm);
8258 	}
8259 #endif
8260 	if (rsm->r_in_tmap) {
8261 		TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8262 		nrsm->r_in_tmap = 1;
8263 	}
8264 	rsm->r_flags &= (~RACK_HAS_FIN);
8265 	rack_update_rsm(tp, rack, rsm, ts, add_flag, segsiz);
8266 	/* Log a split of rsm into rsm and nrsm */
8267 	rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
8268 	*lenp = 0;
8269 	return (0);
8270 }
8271 
8272 static void
8273 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
8274 		uint32_t seq_out, uint16_t th_flags, int32_t err, uint64_t cts,
8275 		struct rack_sendmap *hintrsm, uint16_t add_flag, struct mbuf *s_mb,
8276 		uint32_t s_moff, int hw_tls, int segsiz)
8277 {
8278 	struct tcp_rack *rack;
8279 	struct rack_sendmap *rsm, *nrsm;
8280 	int insret __diagused;
8281 
8282 	register uint32_t snd_max, snd_una;
8283 
8284 	/*
8285 	 * Add to the RACK log of packets in flight or retransmitted. If
8286 	 * there is a TS option we will use the TS echoed, if not we will
8287 	 * grab a TS.
8288 	 *
8289 	 * Retransmissions will increment the count and move the ts to its
8290 	 * proper place. Note that if options do not include TS's then we
8291 	 * won't be able to effectively use the ACK for an RTT on a retran.
8292 	 *
8293 	 * Notes about r_start and r_end. Lets consider a send starting at
8294 	 * sequence 1 for 10 bytes. In such an example the r_start would be
8295 	 * 1 (starting sequence) but the r_end would be r_start+len i.e. 11.
8296 	 * This means that r_end is actually the first sequence for the next
8297 	 * slot (11).
8298 	 *
8299 	 */
8300 	/*
8301 	 * If err is set what do we do XXXrrs? should we not add the thing?
8302 	 * -- i.e. return if err != 0 or should we pretend we sent it? --
8303 	 * i.e. proceed with add ** do this for now.
8304 	 */
8305 	INP_WLOCK_ASSERT(tptoinpcb(tp));
8306 	if (err)
8307 		/*
8308 		 * We don't log errors -- we could but snd_max does not
8309 		 * advance in this case either.
8310 		 */
8311 		return;
8312 
8313 	if (th_flags & TH_RST) {
8314 		/*
8315 		 * We don't log resets and we return immediately from
8316 		 * sending
8317 		 */
8318 		return;
8319 	}
8320 	rack = (struct tcp_rack *)tp->t_fb_ptr;
8321 	snd_una = tp->snd_una;
8322 	snd_max = tp->snd_max;
8323 	if (th_flags & (TH_SYN | TH_FIN)) {
8324 		/*
8325 		 * The call to rack_log_output is made before bumping
8326 		 * snd_max. This means we can record one extra byte on a SYN
8327 		 * or FIN if seq_out is adding more on and a FIN is present
8328 		 * (and we are not resending).
8329 		 */
8330 		if ((th_flags & TH_SYN) && (seq_out == tp->iss))
8331 			len++;
8332 		if (th_flags & TH_FIN)
8333 			len++;
8334 		if (SEQ_LT(snd_max, tp->snd_nxt)) {
8335 			/*
8336 			 * The add/update as not been done for the FIN/SYN
8337 			 * yet.
8338 			 */
8339 			snd_max = tp->snd_nxt;
8340 		}
8341 	}
8342 	if (SEQ_LEQ((seq_out + len), snd_una)) {
8343 		/* Are sending an old segment to induce an ack (keep-alive)? */
8344 		return;
8345 	}
8346 	if (SEQ_LT(seq_out, snd_una)) {
8347 		/* huh? should we panic? */
8348 		uint32_t end;
8349 
8350 		end = seq_out + len;
8351 		seq_out = snd_una;
8352 		if (SEQ_GEQ(end, seq_out))
8353 			len = end - seq_out;
8354 		else
8355 			len = 0;
8356 	}
8357 	if (len == 0) {
8358 		/* We don't log zero window probes */
8359 		return;
8360 	}
8361 	if (IN_FASTRECOVERY(tp->t_flags)) {
8362 		rack->r_ctl.rc_prr_out += len;
8363 	}
8364 	/* First question is it a retransmission or new? */
8365 	if (seq_out == snd_max) {
8366 		/* Its new */
8367 		rack_chk_http_and_hybrid_on_out(rack, seq_out, len, cts);
8368 again:
8369 		rsm = rack_alloc(rack);
8370 		if (rsm == NULL) {
8371 			/*
8372 			 * Hmm out of memory and the tcb got destroyed while
8373 			 * we tried to wait.
8374 			 */
8375 			return;
8376 		}
8377 		if (th_flags & TH_FIN) {
8378 			rsm->r_flags = RACK_HAS_FIN|add_flag;
8379 		} else {
8380 			rsm->r_flags = add_flag;
8381 		}
8382 		if (hw_tls)
8383 			rsm->r_hw_tls = 1;
8384 		rsm->r_tim_lastsent[0] = cts;
8385 		rsm->r_rtr_cnt = 1;
8386 		rsm->r_rtr_bytes = 0;
8387 		if (th_flags & TH_SYN) {
8388 			/* The data space is one beyond snd_una */
8389 			rsm->r_flags |= RACK_HAS_SYN;
8390 		}
8391 		rsm->r_start = seq_out;
8392 		rsm->r_end = rsm->r_start + len;
8393 		rack_mark_in_gp_win(tp, rsm);
8394 		rsm->r_dupack = 0;
8395 		/*
8396 		 * save off the mbuf location that
8397 		 * sndmbuf_noadv returned (which is
8398 		 * where we started copying from)..
8399 		 */
8400 		rsm->m = s_mb;
8401 		rsm->soff = s_moff;
8402 		/*
8403 		 * Here we do add in the len of send, since its not yet
8404 		 * reflected in in snduna <->snd_max
8405 		 */
8406 		rsm->r_fas = (ctf_flight_size(rack->rc_tp,
8407 					      rack->r_ctl.rc_sacked) +
8408 			      (rsm->r_end - rsm->r_start));
8409 		/* rsm->m will be NULL if RACK_HAS_SYN or RACK_HAS_FIN is set */
8410 		if (rsm->m) {
8411 			if (rsm->m->m_len <= rsm->soff) {
8412 				/*
8413 				 * XXXrrs Question, will this happen?
8414 				 *
8415 				 * If sbsndptr is set at the correct place
8416 				 * then s_moff should always be somewhere
8417 				 * within rsm->m. But if the sbsndptr was
8418 				 * off then that won't be true. If it occurs
8419 				 * we need to walkout to the correct location.
8420 				 */
8421 				struct mbuf *lm;
8422 
8423 				lm = rsm->m;
8424 				while (lm->m_len <= rsm->soff) {
8425 					rsm->soff -= lm->m_len;
8426 					lm = lm->m_next;
8427 					KASSERT(lm != NULL, ("%s rack:%p lm goes null orig_off:%u origmb:%p rsm->soff:%u",
8428 							     __func__, rack, s_moff, s_mb, rsm->soff));
8429 				}
8430 				rsm->m = lm;
8431 			}
8432 			rsm->orig_m_len = rsm->m->m_len;
8433 			rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
8434 		} else {
8435 			rsm->orig_m_len = 0;
8436 			rsm->orig_t_space = 0;
8437 		}
8438 		rsm->r_bas = (uint8_t)((len + segsiz - 1) / segsiz);
8439 		rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
8440 		/* Log a new rsm */
8441 		rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_NEW, 0, __LINE__);
8442 #ifndef INVARIANTS
8443 		(void)tqhash_insert(rack->r_ctl.tqh, rsm);
8444 #else
8445 		if ((insret = tqhash_insert(rack->r_ctl.tqh, rsm)) != 0) {
8446 			panic("Insert in rb tree of %p fails ret:%d rack:%p rsm:%p",
8447 			      nrsm, insret, rack, rsm);
8448 		}
8449 #endif
8450 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8451 		rsm->r_in_tmap = 1;
8452 		/*
8453 		 * Special case detection, is there just a single
8454 		 * packet outstanding when we are not in recovery?
8455 		 *
8456 		 * If this is true mark it so.
8457 		 */
8458 		if ((IN_FASTRECOVERY(tp->t_flags) == 0) &&
8459 		    (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) == ctf_fixed_maxseg(tp))) {
8460 			struct rack_sendmap *prsm;
8461 
8462 			prsm = tqhash_prev(rack->r_ctl.tqh, rsm);
8463 			if (prsm)
8464 				prsm->r_one_out_nr = 1;
8465 		}
8466 		return;
8467 	}
8468 	/*
8469 	 * If we reach here its a retransmission and we need to find it.
8470 	 */
8471 more:
8472 	if (hintrsm && (hintrsm->r_start == seq_out)) {
8473 		rsm = hintrsm;
8474 		hintrsm = NULL;
8475 	} else {
8476 		/* No hints sorry */
8477 		rsm = NULL;
8478 	}
8479 	if ((rsm) && (rsm->r_start == seq_out)) {
8480 		seq_out = rack_update_entry(tp, rack, rsm, cts, &len, add_flag, segsiz);
8481 		if (len == 0) {
8482 			return;
8483 		} else {
8484 			goto more;
8485 		}
8486 	}
8487 	/* Ok it was not the last pointer go through it the hard way. */
8488 refind:
8489 	rsm = tqhash_find(rack->r_ctl.tqh, seq_out);
8490 	if (rsm) {
8491 		if (rsm->r_start == seq_out) {
8492 			seq_out = rack_update_entry(tp, rack, rsm, cts, &len, add_flag, segsiz);
8493 			if (len == 0) {
8494 				return;
8495 			} else {
8496 				goto refind;
8497 			}
8498 		}
8499 		if (SEQ_GEQ(seq_out, rsm->r_start) && SEQ_LT(seq_out, rsm->r_end)) {
8500 			/* Transmitted within this piece */
8501 			/*
8502 			 * Ok we must split off the front and then let the
8503 			 * update do the rest
8504 			 */
8505 			nrsm = rack_alloc_full_limit(rack);
8506 			if (nrsm == NULL) {
8507 				rack_update_rsm(tp, rack, rsm, cts, add_flag, segsiz);
8508 				return;
8509 			}
8510 			/*
8511 			 * copy rsm to nrsm and then trim the front of rsm
8512 			 * to not include this part.
8513 			 */
8514 			rack_clone_rsm(rack, nrsm, rsm, seq_out);
8515 			rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
8516 #ifndef INVARIANTS
8517 			(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
8518 #else
8519 			if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
8520 				panic("Insert in rb tree of %p fails ret:%d rack:%p rsm:%p",
8521 				      nrsm, insret, rack, rsm);
8522 			}
8523 #endif
8524 			if (rsm->r_in_tmap) {
8525 				TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8526 				nrsm->r_in_tmap = 1;
8527 			}
8528 			rsm->r_flags &= (~RACK_HAS_FIN);
8529 			seq_out = rack_update_entry(tp, rack, nrsm, cts, &len, add_flag, segsiz);
8530 			if (len == 0) {
8531 				return;
8532 			} else if (len > 0)
8533 				goto refind;
8534 		}
8535 	}
8536 	/*
8537 	 * Hmm not found in map did they retransmit both old and on into the
8538 	 * new?
8539 	 */
8540 	if (seq_out == tp->snd_max) {
8541 		goto again;
8542 	} else if (SEQ_LT(seq_out, tp->snd_max)) {
8543 #ifdef INVARIANTS
8544 		printf("seq_out:%u len:%d snd_una:%u snd_max:%u -- but rsm not found?\n",
8545 		       seq_out, len, tp->snd_una, tp->snd_max);
8546 		printf("Starting Dump of all rack entries\n");
8547 		TQHASH_FOREACH(rsm, rack->r_ctl.tqh)  {
8548 			printf("rsm:%p start:%u end:%u\n",
8549 			       rsm, rsm->r_start, rsm->r_end);
8550 		}
8551 		printf("Dump complete\n");
8552 		panic("seq_out not found rack:%p tp:%p",
8553 		      rack, tp);
8554 #endif
8555 	} else {
8556 #ifdef INVARIANTS
8557 		/*
8558 		 * Hmm beyond sndmax? (only if we are using the new rtt-pack
8559 		 * flag)
8560 		 */
8561 		panic("seq_out:%u(%d) is beyond snd_max:%u tp:%p",
8562 		      seq_out, len, tp->snd_max, tp);
8563 #endif
8564 	}
8565 }
8566 
8567 /*
8568  * Record one of the RTT updates from an ack into
8569  * our sample structure.
8570  */
8571 
8572 static void
8573 tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt, uint32_t len, uint32_t us_rtt,
8574 		    int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt)
8575 {
8576 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
8577 	    (rack->r_ctl.rack_rs.rs_rtt_lowest > rtt)) {
8578 		rack->r_ctl.rack_rs.rs_rtt_lowest = rtt;
8579 	}
8580 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
8581 	    (rack->r_ctl.rack_rs.rs_rtt_highest < rtt)) {
8582 		rack->r_ctl.rack_rs.rs_rtt_highest = rtt;
8583 	}
8584 	if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
8585 	    if (us_rtt < rack->r_ctl.rc_gp_lowrtt)
8586 		rack->r_ctl.rc_gp_lowrtt = us_rtt;
8587 	    if (rack->rc_tp->snd_wnd > rack->r_ctl.rc_gp_high_rwnd)
8588 		    rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
8589 	}
8590 	if ((confidence == 1) &&
8591 	    ((rsm == NULL) ||
8592 	     (rsm->r_just_ret) ||
8593 	     (rsm->r_one_out_nr &&
8594 	      len < (ctf_fixed_maxseg(rack->rc_tp) * 2)))) {
8595 		/*
8596 		 * If the rsm had a just return
8597 		 * hit it then we can't trust the
8598 		 * rtt measurement for buffer deterimination
8599 		 * Note that a confidence of 2, indicates
8600 		 * SACK'd which overrides the r_just_ret or
8601 		 * the r_one_out_nr. If it was a CUM-ACK and
8602 		 * we had only two outstanding, but get an
8603 		 * ack for only 1. Then that also lowers our
8604 		 * confidence.
8605 		 */
8606 		confidence = 0;
8607 	}
8608 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
8609 	    (rack->r_ctl.rack_rs.rs_us_rtt > us_rtt)) {
8610 		if (rack->r_ctl.rack_rs.confidence == 0) {
8611 			/*
8612 			 * We take anything with no current confidence
8613 			 * saved.
8614 			 */
8615 			rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
8616 			rack->r_ctl.rack_rs.confidence = confidence;
8617 			rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
8618 		} else if (confidence != 0) {
8619 			/*
8620 			 * Once we have a confident number,
8621 			 * we can update it with a smaller
8622 			 * value since this confident number
8623 			 * may include the DSACK time until
8624 			 * the next segment (the second one) arrived.
8625 			 */
8626 			rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
8627 			rack->r_ctl.rack_rs.confidence = confidence;
8628 			rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
8629 		}
8630 	}
8631 	rack_log_rtt_upd(rack->rc_tp, rack, us_rtt, len, rsm, confidence);
8632 	rack->r_ctl.rack_rs.rs_flags = RACK_RTT_VALID;
8633 	rack->r_ctl.rack_rs.rs_rtt_tot += rtt;
8634 	rack->r_ctl.rack_rs.rs_rtt_cnt++;
8635 }
8636 
8637 /*
8638  * Collect new round-trip time estimate
8639  * and update averages and current timeout.
8640  */
8641 static void
8642 tcp_rack_xmit_timer_commit(struct tcp_rack *rack, struct tcpcb *tp)
8643 {
8644 	int32_t delta;
8645 	int32_t rtt;
8646 
8647 	if (rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY)
8648 		/* No valid sample */
8649 		return;
8650 	if (rack->r_ctl.rc_rate_sample_method == USE_RTT_LOW) {
8651 		/* We are to use the lowest RTT seen in a single ack */
8652 		rtt = rack->r_ctl.rack_rs.rs_rtt_lowest;
8653 	} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_HIGH) {
8654 		/* We are to use the highest RTT seen in a single ack */
8655 		rtt = rack->r_ctl.rack_rs.rs_rtt_highest;
8656 	} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_AVG) {
8657 		/* We are to use the average RTT seen in a single ack */
8658 		rtt = (int32_t)(rack->r_ctl.rack_rs.rs_rtt_tot /
8659 				(uint64_t)rack->r_ctl.rack_rs.rs_rtt_cnt);
8660 	} else {
8661 #ifdef INVARIANTS
8662 		panic("Unknown rtt variant %d", rack->r_ctl.rc_rate_sample_method);
8663 #endif
8664 		return;
8665 	}
8666 	if (rtt == 0)
8667 		rtt = 1;
8668 	if (rack->rc_gp_rtt_set == 0) {
8669 		/*
8670 		 * With no RTT we have to accept
8671 		 * even one we are not confident of.
8672 		 */
8673 		rack->r_ctl.rc_gp_srtt = rack->r_ctl.rack_rs.rs_us_rtt;
8674 		rack->rc_gp_rtt_set = 1;
8675 	} else if (rack->r_ctl.rack_rs.confidence) {
8676 		/* update the running gp srtt */
8677 		rack->r_ctl.rc_gp_srtt -= (rack->r_ctl.rc_gp_srtt/8);
8678 		rack->r_ctl.rc_gp_srtt += rack->r_ctl.rack_rs.rs_us_rtt / 8;
8679 	}
8680 	if (rack->r_ctl.rack_rs.confidence) {
8681 		/*
8682 		 * record the low and high for highly buffered path computation,
8683 		 * we only do this if we are confident (not a retransmission).
8684 		 */
8685 		if (rack->r_ctl.rc_highest_us_rtt < rack->r_ctl.rack_rs.rs_us_rtt) {
8686 			rack->r_ctl.rc_highest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
8687 		}
8688 		if (rack->rc_highly_buffered == 0) {
8689 			/*
8690 			 * Currently once we declare a path has
8691 			 * highly buffered there is no going
8692 			 * back, which may be a problem...
8693 			 */
8694 			if ((rack->r_ctl.rc_highest_us_rtt / rack->r_ctl.rc_lowest_us_rtt) > rack_hbp_thresh) {
8695 				rack_log_rtt_shrinks(rack, rack->r_ctl.rack_rs.rs_us_rtt,
8696 						     rack->r_ctl.rc_highest_us_rtt,
8697 						     rack->r_ctl.rc_lowest_us_rtt,
8698 						     RACK_RTTS_SEEHBP);
8699 				rack->rc_highly_buffered = 1;
8700 			}
8701 		}
8702 	}
8703 	if ((rack->r_ctl.rack_rs.confidence) ||
8704 	    (rack->r_ctl.rack_rs.rs_us_rtrcnt == 1)) {
8705 		/*
8706 		 * If we are highly confident of it <or> it was
8707 		 * never retransmitted we accept it as the last us_rtt.
8708 		 */
8709 		rack->r_ctl.rc_last_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
8710 		/* The lowest rtt can be set if its was not retransmited */
8711 		if (rack->r_ctl.rc_lowest_us_rtt > rack->r_ctl.rack_rs.rs_us_rtt) {
8712 			rack->r_ctl.rc_lowest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
8713 			if (rack->r_ctl.rc_lowest_us_rtt == 0)
8714 				rack->r_ctl.rc_lowest_us_rtt = 1;
8715 		}
8716 	}
8717 	rack = (struct tcp_rack *)tp->t_fb_ptr;
8718 	if (tp->t_srtt != 0) {
8719 		/*
8720 		 * We keep a simple srtt in microseconds, like our rtt
8721 		 * measurement. We don't need to do any tricks with shifting
8722 		 * etc. Instead we just add in 1/8th of the new measurement
8723 		 * and subtract out 1/8 of the old srtt. We do the same with
8724 		 * the variance after finding the absolute value of the
8725 		 * difference between this sample and the current srtt.
8726 		 */
8727 		delta = tp->t_srtt - rtt;
8728 		/* Take off 1/8th of the current sRTT */
8729 		tp->t_srtt -= (tp->t_srtt >> 3);
8730 		/* Add in 1/8th of the new RTT just measured */
8731 		tp->t_srtt += (rtt >> 3);
8732 		if (tp->t_srtt <= 0)
8733 			tp->t_srtt = 1;
8734 		/* Now lets make the absolute value of the variance */
8735 		if (delta < 0)
8736 			delta = -delta;
8737 		/* Subtract out 1/8th */
8738 		tp->t_rttvar -= (tp->t_rttvar >> 3);
8739 		/* Add in 1/8th of the new variance we just saw */
8740 		tp->t_rttvar += (delta >> 3);
8741 		if (tp->t_rttvar <= 0)
8742 			tp->t_rttvar = 1;
8743 	} else {
8744 		/*
8745 		 * No rtt measurement yet - use the unsmoothed rtt. Set the
8746 		 * variance to half the rtt (so our first retransmit happens
8747 		 * at 3*rtt).
8748 		 */
8749 		tp->t_srtt = rtt;
8750 		tp->t_rttvar = rtt >> 1;
8751 	}
8752 	rack->rc_srtt_measure_made = 1;
8753 	KMOD_TCPSTAT_INC(tcps_rttupdated);
8754 	if (tp->t_rttupdated < UCHAR_MAX)
8755 		tp->t_rttupdated++;
8756 #ifdef STATS
8757 	if (rack_stats_gets_ms_rtt == 0) {
8758 		/* Send in the microsecond rtt used for rxt timeout purposes */
8759 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rtt));
8760 	} else if (rack_stats_gets_ms_rtt == 1) {
8761 		/* Send in the millisecond rtt used for rxt timeout purposes */
8762 		int32_t ms_rtt;
8763 
8764 		/* Round up */
8765 		ms_rtt = (rtt + HPTS_USEC_IN_MSEC - 1) / HPTS_USEC_IN_MSEC;
8766 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, ms_rtt));
8767 	} else if (rack_stats_gets_ms_rtt == 2) {
8768 		/* Send in the millisecond rtt has close to the path RTT as we can get  */
8769 		int32_t ms_rtt;
8770 
8771 		/* Round up */
8772 		ms_rtt = (rack->r_ctl.rack_rs.rs_us_rtt + HPTS_USEC_IN_MSEC - 1) / HPTS_USEC_IN_MSEC;
8773 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, ms_rtt));
8774 	}  else {
8775 		/* Send in the microsecond rtt has close to the path RTT as we can get  */
8776 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rack->r_ctl.rack_rs.rs_us_rtt));
8777 	}
8778 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_PATHRTT, imax(0, rack->r_ctl.rack_rs.rs_us_rtt));
8779 #endif
8780 	/*
8781 	 * the retransmit should happen at rtt + 4 * rttvar. Because of the
8782 	 * way we do the smoothing, srtt and rttvar will each average +1/2
8783 	 * tick of bias.  When we compute the retransmit timer, we want 1/2
8784 	 * tick of rounding and 1 extra tick because of +-1/2 tick
8785 	 * uncertainty in the firing of the timer.  The bias will give us
8786 	 * exactly the 1.5 tick we need.  But, because the bias is
8787 	 * statistical, we have to test that we don't drop below the minimum
8788 	 * feasible timer (which is 2 ticks).
8789 	 */
8790 	tp->t_rxtshift = 0;
8791 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
8792 		      max(rack_rto_min, rtt + 2), rack_rto_max, rack->r_ctl.timer_slop);
8793 	rack_log_rtt_sample(rack, rtt);
8794 	tp->t_softerror = 0;
8795 }
8796 
8797 
8798 static void
8799 rack_apply_updated_usrtt(struct tcp_rack *rack, uint32_t us_rtt, uint32_t us_cts)
8800 {
8801 	/*
8802 	 * Apply to filter the inbound us-rtt at us_cts.
8803 	 */
8804 	uint32_t old_rtt;
8805 
8806 	old_rtt = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
8807 	apply_filter_min_small(&rack->r_ctl.rc_gp_min_rtt,
8808 			       us_rtt, us_cts);
8809 	if (old_rtt > us_rtt) {
8810 		/* We just hit a new lower rtt time */
8811 		rack_log_rtt_shrinks(rack,  us_cts,  old_rtt,
8812 				     __LINE__, RACK_RTTS_NEWRTT);
8813 		/*
8814 		 * Only count it if its lower than what we saw within our
8815 		 * calculated range.
8816 		 */
8817 		if ((old_rtt - us_rtt) > rack_min_rtt_movement) {
8818 			if (rack_probertt_lower_within &&
8819 			    rack->rc_gp_dyn_mul &&
8820 			    (rack->use_fixed_rate == 0) &&
8821 			    (rack->rc_always_pace)) {
8822 				/*
8823 				 * We are seeing a new lower rtt very close
8824 				 * to the time that we would have entered probe-rtt.
8825 				 * This is probably due to the fact that a peer flow
8826 				 * has entered probe-rtt. Lets go in now too.
8827 				 */
8828 				uint32_t val;
8829 
8830 				val = rack_probertt_lower_within * rack_time_between_probertt;
8831 				val /= 100;
8832 				if ((rack->in_probe_rtt == 0)  &&
8833 				    ((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= (rack_time_between_probertt - val)))	{
8834 					rack_enter_probertt(rack, us_cts);
8835 				}
8836 			}
8837 			rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
8838 		}
8839 	}
8840 }
8841 
8842 static int
8843 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
8844     struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack)
8845 {
8846 	uint32_t us_rtt;
8847 	int32_t i, all;
8848 	uint32_t t, len_acked;
8849 
8850 	if ((rsm->r_flags & RACK_ACKED) ||
8851 	    (rsm->r_flags & RACK_WAS_ACKED))
8852 		/* Already done */
8853 		return (0);
8854 	if (rsm->r_no_rtt_allowed) {
8855 		/* Not allowed */
8856 		return (0);
8857 	}
8858 	if (ack_type == CUM_ACKED) {
8859 		if (SEQ_GT(th_ack, rsm->r_end)) {
8860 			len_acked = rsm->r_end - rsm->r_start;
8861 			all = 1;
8862 		} else {
8863 			len_acked = th_ack - rsm->r_start;
8864 			all = 0;
8865 		}
8866 	} else {
8867 		len_acked = rsm->r_end - rsm->r_start;
8868 		all = 0;
8869 	}
8870 	if (rsm->r_rtr_cnt == 1) {
8871 
8872 		t = cts - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
8873 		if ((int)t <= 0)
8874 			t = 1;
8875 		if (!tp->t_rttlow || tp->t_rttlow > t)
8876 			tp->t_rttlow = t;
8877 		if (!rack->r_ctl.rc_rack_min_rtt ||
8878 		    SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
8879 			rack->r_ctl.rc_rack_min_rtt = t;
8880 			if (rack->r_ctl.rc_rack_min_rtt == 0) {
8881 				rack->r_ctl.rc_rack_min_rtt = 1;
8882 			}
8883 		}
8884 		if (TSTMP_GT(tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time), rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]))
8885 			us_rtt = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8886 		else
8887 			us_rtt = tcp_get_usecs(NULL) - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8888 		if (us_rtt == 0)
8889 			us_rtt = 1;
8890 		if (CC_ALGO(tp)->rttsample != NULL) {
8891 			/* Kick the RTT to the CC */
8892 			CC_ALGO(tp)->rttsample(&tp->t_ccv, us_rtt, 1, rsm->r_fas);
8893 		}
8894 		rack_apply_updated_usrtt(rack, us_rtt, tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time));
8895 		if (ack_type == SACKED) {
8896 			rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)], cts, 1);
8897 			tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt, 2 , rsm, rsm->r_rtr_cnt);
8898 		} else {
8899 			/*
8900 			 * We need to setup what our confidence
8901 			 * is in this ack.
8902 			 *
8903 			 * If the rsm was app limited and it is
8904 			 * less than a mss in length (the end
8905 			 * of the send) then we have a gap. If we
8906 			 * were app limited but say we were sending
8907 			 * multiple MSS's then we are more confident
8908 			 * int it.
8909 			 *
8910 			 * When we are not app-limited then we see if
8911 			 * the rsm is being included in the current
8912 			 * measurement, we tell this by the app_limited_needs_set
8913 			 * flag.
8914 			 *
8915 			 * Note that being cwnd blocked is not applimited
8916 			 * as well as the pacing delay between packets which
8917 			 * are sending only 1 or 2 MSS's also will show up
8918 			 * in the RTT. We probably need to examine this algorithm
8919 			 * a bit more and enhance it to account for the delay
8920 			 * between rsm's. We could do that by saving off the
8921 			 * pacing delay of each rsm (in an rsm) and then
8922 			 * factoring that in somehow though for now I am
8923 			 * not sure how :)
8924 			 */
8925 			int calc_conf = 0;
8926 
8927 			if (rsm->r_flags & RACK_APP_LIMITED) {
8928 				if (all && (len_acked <= ctf_fixed_maxseg(tp)))
8929 					calc_conf = 0;
8930 				else
8931 					calc_conf = 1;
8932 			} else if (rack->app_limited_needs_set == 0) {
8933 				calc_conf = 1;
8934 			} else {
8935 				calc_conf = 0;
8936 			}
8937 			rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)], cts, 2);
8938 			tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt,
8939 					    calc_conf, rsm, rsm->r_rtr_cnt);
8940 		}
8941 		if ((rsm->r_flags & RACK_TLP) &&
8942 		    (!IN_FASTRECOVERY(tp->t_flags))) {
8943 			/* Segment was a TLP and our retrans matched */
8944 			if (rack->r_ctl.rc_tlp_cwnd_reduce) {
8945 				rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
8946 			}
8947 		}
8948 		if ((rack->r_ctl.rc_rack_tmit_time == 0) ||
8949 		    (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
8950 			    (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]))) {
8951 			/* New more recent rack_tmit_time */
8952 			rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
8953 			if (rack->r_ctl.rc_rack_tmit_time == 0)
8954 				rack->r_ctl.rc_rack_tmit_time = 1;
8955 			rack->rc_rack_rtt = t;
8956 		}
8957 		return (1);
8958 	}
8959 	/*
8960 	 * We clear the soft/rxtshift since we got an ack.
8961 	 * There is no assurance we will call the commit() function
8962 	 * so we need to clear these to avoid incorrect handling.
8963 	 */
8964 	tp->t_rxtshift = 0;
8965 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
8966 		      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
8967 	tp->t_softerror = 0;
8968 	if (to && (to->to_flags & TOF_TS) &&
8969 	    (ack_type == CUM_ACKED) &&
8970 	    (to->to_tsecr) &&
8971 	    ((rsm->r_flags & RACK_OVERMAX) == 0)) {
8972 		/*
8973 		 * Now which timestamp does it match? In this block the ACK
8974 		 * must be coming from a previous transmission.
8975 		 */
8976 		for (i = 0; i < rsm->r_rtr_cnt; i++) {
8977 			if (rack_ts_to_msec(rsm->r_tim_lastsent[i]) == to->to_tsecr) {
8978 				t = cts - (uint32_t)rsm->r_tim_lastsent[i];
8979 				if ((int)t <= 0)
8980 					t = 1;
8981 				if (CC_ALGO(tp)->rttsample != NULL) {
8982 					/*
8983 					 * Kick the RTT to the CC, here
8984 					 * we lie a bit in that we know the
8985 					 * retransmission is correct even though
8986 					 * we retransmitted. This is because
8987 					 * we match the timestamps.
8988 					 */
8989 					if (TSTMP_GT(tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time), rsm->r_tim_lastsent[i]))
8990 						us_rtt = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - (uint32_t)rsm->r_tim_lastsent[i];
8991 					else
8992 						us_rtt = tcp_get_usecs(NULL) - (uint32_t)rsm->r_tim_lastsent[i];
8993 					CC_ALGO(tp)->rttsample(&tp->t_ccv, us_rtt, 1, rsm->r_fas);
8994 				}
8995 				if ((i + 1) < rsm->r_rtr_cnt) {
8996 					/*
8997 					 * The peer ack'd from our previous
8998 					 * transmission. We have a spurious
8999 					 * retransmission and thus we dont
9000 					 * want to update our rack_rtt.
9001 					 *
9002 					 * Hmm should there be a CC revert here?
9003 					 *
9004 					 */
9005 					return (0);
9006 				}
9007 				if (!tp->t_rttlow || tp->t_rttlow > t)
9008 					tp->t_rttlow = t;
9009 				if (!rack->r_ctl.rc_rack_min_rtt || SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
9010 					rack->r_ctl.rc_rack_min_rtt = t;
9011 					if (rack->r_ctl.rc_rack_min_rtt == 0) {
9012 						rack->r_ctl.rc_rack_min_rtt = 1;
9013 					}
9014 				}
9015 				if ((rack->r_ctl.rc_rack_tmit_time == 0) ||
9016 				    (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
9017 					    (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]))) {
9018 					/* New more recent rack_tmit_time */
9019 					rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
9020 					if (rack->r_ctl.rc_rack_tmit_time == 0)
9021 						rack->r_ctl.rc_rack_tmit_time = 1;
9022 					rack->rc_rack_rtt = t;
9023 				}
9024 				rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[i], cts, 3);
9025 				tcp_rack_xmit_timer(rack, t + 1, len_acked, t, 0, rsm,
9026 						    rsm->r_rtr_cnt);
9027 				return (1);
9028 			}
9029 		}
9030 		/* If we are logging log out the sendmap */
9031 		if (tcp_bblogging_on(rack->rc_tp)) {
9032 			for (i = 0; i < rsm->r_rtr_cnt; i++) {
9033 				rack_log_rtt_sendmap(rack, i, rsm->r_tim_lastsent[i], to->to_tsecr);
9034 			}
9035 		}
9036 		goto ts_not_found;
9037 	} else {
9038 		/*
9039 		 * Ok its a SACK block that we retransmitted. or a windows
9040 		 * machine without timestamps. We can tell nothing from the
9041 		 * time-stamp since its not there or the time the peer last
9042 		 * recieved a segment that moved forward its cum-ack point.
9043 		 */
9044 ts_not_found:
9045 		i = rsm->r_rtr_cnt - 1;
9046 		t = cts - (uint32_t)rsm->r_tim_lastsent[i];
9047 		if ((int)t <= 0)
9048 			t = 1;
9049 		if (rack->r_ctl.rc_rack_min_rtt && SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
9050 			/*
9051 			 * We retransmitted and the ack came back in less
9052 			 * than the smallest rtt we have observed. We most
9053 			 * likely did an improper retransmit as outlined in
9054 			 * 6.2 Step 2 point 2 in the rack-draft so we
9055 			 * don't want to update our rack_rtt. We in
9056 			 * theory (in future) might want to think about reverting our
9057 			 * cwnd state but we won't for now.
9058 			 */
9059 			return (0);
9060 		} else if (rack->r_ctl.rc_rack_min_rtt) {
9061 			/*
9062 			 * We retransmitted it and the retransmit did the
9063 			 * job.
9064 			 */
9065 			if (!rack->r_ctl.rc_rack_min_rtt ||
9066 			    SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
9067 				rack->r_ctl.rc_rack_min_rtt = t;
9068 				if (rack->r_ctl.rc_rack_min_rtt == 0) {
9069 					rack->r_ctl.rc_rack_min_rtt = 1;
9070 				}
9071 			}
9072 			if ((rack->r_ctl.rc_rack_tmit_time == 0) ||
9073 			    (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
9074 				    (uint32_t)rsm->r_tim_lastsent[i]))) {
9075 				/* New more recent rack_tmit_time */
9076 				rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[i];
9077 				if (rack->r_ctl.rc_rack_tmit_time == 0)
9078 					rack->r_ctl.rc_rack_tmit_time = 1;
9079 				rack->rc_rack_rtt = t;
9080 			}
9081 			return (1);
9082 		}
9083 	}
9084 	return (0);
9085 }
9086 
9087 /*
9088  * Mark the SACK_PASSED flag on all entries prior to rsm send wise.
9089  */
9090 static void
9091 rack_log_sack_passed(struct tcpcb *tp,
9092     struct tcp_rack *rack, struct rack_sendmap *rsm)
9093 {
9094 	struct rack_sendmap *nrsm;
9095 
9096 	nrsm = rsm;
9097 	TAILQ_FOREACH_REVERSE_FROM(nrsm, &rack->r_ctl.rc_tmap,
9098 	    rack_head, r_tnext) {
9099 		if (nrsm == rsm) {
9100 			/* Skip original segment he is acked */
9101 			continue;
9102 		}
9103 		if (nrsm->r_flags & RACK_ACKED) {
9104 			/*
9105 			 * Skip ack'd segments, though we
9106 			 * should not see these, since tmap
9107 			 * should not have ack'd segments.
9108 			 */
9109 			continue;
9110 		}
9111 		if (nrsm->r_flags & RACK_RWND_COLLAPSED) {
9112 			/*
9113 			 * If the peer dropped the rwnd on
9114 			 * these then we don't worry about them.
9115 			 */
9116 			continue;
9117 		}
9118 		if (nrsm->r_flags & RACK_SACK_PASSED) {
9119 			/*
9120 			 * We found one that is already marked
9121 			 * passed, we have been here before and
9122 			 * so all others below this are marked.
9123 			 */
9124 			break;
9125 		}
9126 		nrsm->r_flags |= RACK_SACK_PASSED;
9127 		nrsm->r_flags &= ~RACK_WAS_SACKPASS;
9128 	}
9129 }
9130 
9131 static void
9132 rack_need_set_test(struct tcpcb *tp,
9133 		   struct tcp_rack *rack,
9134 		   struct rack_sendmap *rsm,
9135 		   tcp_seq th_ack,
9136 		   int line,
9137 		   int use_which)
9138 {
9139 	struct rack_sendmap *s_rsm;
9140 
9141 	if ((tp->t_flags & TF_GPUTINPROG) &&
9142 	    SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
9143 		/*
9144 		 * We were app limited, and this ack
9145 		 * butts up or goes beyond the point where we want
9146 		 * to start our next measurement. We need
9147 		 * to record the new gput_ts as here and
9148 		 * possibly update the start sequence.
9149 		 */
9150 		uint32_t seq, ts;
9151 
9152 		if (rsm->r_rtr_cnt > 1) {
9153 			/*
9154 			 * This is a retransmit, can we
9155 			 * really make any assessment at this
9156 			 * point?  We are not really sure of
9157 			 * the timestamp, is it this or the
9158 			 * previous transmission?
9159 			 *
9160 			 * Lets wait for something better that
9161 			 * is not retransmitted.
9162 			 */
9163 			return;
9164 		}
9165 		seq = tp->gput_seq;
9166 		ts = tp->gput_ts;
9167 		rack->app_limited_needs_set = 0;
9168 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
9169 		/* Do we start at a new end? */
9170 		if ((use_which == RACK_USE_BEG) &&
9171 		    SEQ_GEQ(rsm->r_start, tp->gput_seq)) {
9172 			/*
9173 			 * When we get an ACK that just eats
9174 			 * up some of the rsm, we set RACK_USE_BEG
9175 			 * since whats at r_start (i.e. th_ack)
9176 			 * is left unacked and thats where the
9177 			 * measurement now starts.
9178 			 */
9179 			tp->gput_seq = rsm->r_start;
9180 		}
9181 		if ((use_which == RACK_USE_END) &&
9182 		    SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
9183 			/*
9184 			 * We use the end when the cumack
9185 			 * is moving forward and completely
9186 			 * deleting the rsm passed so basically
9187 			 * r_end holds th_ack.
9188 			 *
9189 			 * For SACK's we also want to use the end
9190 			 * since this piece just got sacked and
9191 			 * we want to target anything after that
9192 			 * in our measurement.
9193 			 */
9194 			tp->gput_seq = rsm->r_end;
9195 		}
9196 		if (use_which == RACK_USE_END_OR_THACK) {
9197 			/*
9198 			 * special case for ack moving forward,
9199 			 * not a sack, we need to move all the
9200 			 * way up to where this ack cum-ack moves
9201 			 * to.
9202 			 */
9203 			if (SEQ_GT(th_ack, rsm->r_end))
9204 				tp->gput_seq = th_ack;
9205 			else
9206 				tp->gput_seq = rsm->r_end;
9207 		}
9208 		if (SEQ_LT(tp->gput_seq, tp->snd_max))
9209 			s_rsm = tqhash_find(rack->r_ctl.tqh, tp->gput_seq);
9210 		else
9211 			s_rsm = NULL;
9212 		/*
9213 		 * Pick up the correct send time if we can the rsm passed in
9214 		 * may be equal to s_rsm if the RACK_USE_BEG was set. For the other
9215 		 * two cases (RACK_USE_THACK or RACK_USE_END) most likely we will
9216 		 * find a different seq i.e. the next send up.
9217 		 *
9218 		 * If that has not been sent, s_rsm will be NULL and we must
9219 		 * arrange it so this function will get called again by setting
9220 		 * app_limited_needs_set.
9221 		 */
9222 		if (s_rsm)
9223 			rack->r_ctl.rc_gp_output_ts = s_rsm->r_tim_lastsent[0];
9224 		else {
9225 			/* If we hit here we have to have *not* sent tp->gput_seq */
9226 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[0];
9227 			/* Set it up so we will go through here again */
9228 			rack->app_limited_needs_set = 1;
9229 		}
9230 		if (SEQ_GT(tp->gput_seq, tp->gput_ack)) {
9231 			/*
9232 			 * We moved beyond this guy's range, re-calculate
9233 			 * the new end point.
9234 			 */
9235 			if (rack->rc_gp_filled == 0) {
9236 				tp->gput_ack = tp->gput_seq + max(rc_init_window(rack), (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
9237 			} else {
9238 				tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
9239 			}
9240 		}
9241 		/*
9242 		 * We are moving the goal post, we may be able to clear the
9243 		 * measure_saw_probe_rtt flag.
9244 		 */
9245 		if ((rack->in_probe_rtt == 0) &&
9246 		    (rack->measure_saw_probe_rtt) &&
9247 		    (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
9248 			rack->measure_saw_probe_rtt = 0;
9249 		rack_log_pacing_delay_calc(rack, ts, tp->gput_ts,
9250 					   seq, tp->gput_seq,
9251 					   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) |
9252 					    (uint64_t)rack->r_ctl.rc_gp_output_ts),
9253 					   5, line, NULL, 0);
9254 		if (rack->rc_gp_filled &&
9255 		    ((tp->gput_ack - tp->gput_seq) <
9256 		     max(rc_init_window(rack), (MIN_GP_WIN *
9257 						ctf_fixed_maxseg(tp))))) {
9258 			uint32_t ideal_amount;
9259 
9260 			ideal_amount = rack_get_measure_window(tp, rack);
9261 			if (ideal_amount > sbavail(&tptosocket(tp)->so_snd)) {
9262 				/*
9263 				 * There is no sense of continuing this measurement
9264 				 * because its too small to gain us anything we
9265 				 * trust. Skip it and that way we can start a new
9266 				 * measurement quicker.
9267 				 */
9268 				tp->t_flags &= ~TF_GPUTINPROG;
9269 				rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
9270 							   0, 0,
9271 							   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) |
9272 							    (uint64_t)rack->r_ctl.rc_gp_output_ts),
9273 							   6, __LINE__, NULL, 0);
9274 			} else {
9275 				/*
9276 				 * Reset the window further out.
9277 				 */
9278 				tp->gput_ack = tp->gput_seq + ideal_amount;
9279 			}
9280 		}
9281 		rack_tend_gp_marks(tp, rack);
9282 		rack_log_gpset(rack, tp->gput_ack, 0, 0, line, 2, rsm);
9283 	}
9284 }
9285 
9286 static inline int
9287 is_rsm_inside_declared_tlp_block(struct tcp_rack *rack, struct rack_sendmap *rsm)
9288 {
9289 	if (SEQ_LT(rsm->r_end, rack->r_ctl.last_tlp_acked_start)) {
9290 		/* Behind our TLP definition or right at */
9291 		return (0);
9292 	}
9293 	if (SEQ_GT(rsm->r_start, rack->r_ctl.last_tlp_acked_end)) {
9294 		/* The start is beyond or right at our end of TLP definition */
9295 		return (0);
9296 	}
9297 	/* It has to be a sub-part of the original TLP recorded */
9298 	return (1);
9299 }
9300 
9301 
9302 
9303 static uint32_t
9304 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack, struct sackblk *sack,
9305 		   struct tcpopt *to, struct rack_sendmap **prsm, uint32_t cts,
9306 		   int *no_extra,
9307 		   int *moved_two, uint32_t segsiz)
9308 {
9309 	uint32_t start, end, changed = 0;
9310 	struct rack_sendmap stack_map;
9311 	struct rack_sendmap *rsm, *nrsm, *prev, *next;
9312 	int insret __diagused;
9313 	int32_t used_ref = 1;
9314 	int moved = 0;
9315 #ifdef TCP_SAD_DETECTION
9316 	int allow_segsiz;
9317 	int first_time_through = 1;
9318 #endif
9319 	int noextra = 0;
9320 	int can_use_hookery = 0;
9321 
9322 	start = sack->start;
9323 	end = sack->end;
9324 	rsm = *prsm;
9325 
9326 #ifdef TCP_SAD_DETECTION
9327 	/*
9328 	 * There are a strange number of proxys and meddle boxes in the world
9329 	 * that seem to cut up segments on different boundaries. This gets us
9330 	 * smaller sacks that are still ok in terms of it being an attacker.
9331 	 * We use the base segsiz to calculate an allowable smallness but
9332 	 * also enforce a min on the segsiz in case it is an attacker playing
9333 	 * games with MSS. So basically if the sack arrives and it is
9334 	 * larger than a worse case 960 bytes, we don't classify the guy
9335 	 * as supicious.
9336 	 */
9337 	allow_segsiz = max(segsiz, 1200) * sad_seg_size_per;
9338 	allow_segsiz /= 1000;
9339 #endif
9340 do_rest_ofb:
9341 	if ((rsm == NULL) ||
9342 	    (SEQ_LT(end, rsm->r_start)) ||
9343 	    (SEQ_GEQ(start, rsm->r_end)) ||
9344 	    (SEQ_LT(start, rsm->r_start))) {
9345 		/*
9346 		 * We are not in the right spot,
9347 		 * find the correct spot in the tree.
9348 		 */
9349 		used_ref = 0;
9350 		rsm = tqhash_find(rack->r_ctl.tqh, start);
9351 		moved++;
9352 	}
9353 	if (rsm == NULL) {
9354 		/* TSNH */
9355 		goto out;
9356 	}
9357 #ifdef TCP_SAD_DETECTION
9358 	/* Now we must check for suspicous activity */
9359 	if ((first_time_through == 1) &&
9360 	    ((end - start) < min((rsm->r_end - rsm->r_start), allow_segsiz)) &&
9361 	    ((rsm->r_flags & RACK_PMTU_CHG) == 0) &&
9362 	    ((rsm->r_flags & RACK_TLP) == 0)) {
9363 		/*
9364 		 * Its less than a full MSS or the segment being acked
9365 		 * this should only happen if the rsm in question had the
9366 		 * r_just_ret flag set <and> the end matches the end of
9367 		 * the rsm block.
9368 		 *
9369 		 * Note we do not look at segments that have had TLP's on
9370 		 * them since we can get un-reported rwnd collapses that
9371 		 * basically we TLP on and then we get back a sack block
9372 		 * that goes from the start to only a small way.
9373 		 *
9374 		 */
9375 		int loss, ok;
9376 
9377 		ok = 0;
9378 		if (SEQ_GEQ(end, rsm->r_end)) {
9379 			if (rsm->r_just_ret == 1) {
9380 				/* This was at the end of a send which is ok */
9381 				ok = 1;
9382 			} else {
9383 				/* A bit harder was it the end of our segment */
9384 				int segs, len;
9385 
9386 				len = (rsm->r_end - rsm->r_start);
9387 				segs = len / segsiz;
9388 				segs *= segsiz;
9389 				if ((segs + (rsm->r_end - start)) == len) {
9390 					/*
9391 					 * So this last bit was the
9392 					 * end of our send if we cut it
9393 					 * up into segsiz pieces so its ok.
9394 					 */
9395 					ok = 1;
9396 				}
9397 			}
9398 		}
9399 		if (ok == 0) {
9400 			/*
9401 			 * This guy is doing something suspicious
9402 			 * lets start detection.
9403 			 */
9404 			if (rack->rc_suspicious == 0) {
9405 				tcp_trace_point(rack->rc_tp, TCP_TP_SAD_SUSPECT);
9406 				counter_u64_add(rack_sack_attacks_suspect, 1);
9407 				rack->rc_suspicious = 1;
9408 				rack_log_sad(rack, 4);
9409 				if (tcp_bblogging_on(rack->rc_tp)) {
9410 					union tcp_log_stackspecific log;
9411 					struct timeval tv;
9412 
9413 					memset(&log.u_bbr, 0, sizeof(log.u_bbr));
9414 					log.u_bbr.flex1 = end;
9415 					log.u_bbr.flex2 = start;
9416 					log.u_bbr.flex3 = rsm->r_end;
9417 					log.u_bbr.flex4 = rsm->r_start;
9418 					log.u_bbr.flex5 = segsiz;
9419 					log.u_bbr.flex6 = rsm->r_fas;
9420 					log.u_bbr.flex7 = rsm->r_bas;
9421 					log.u_bbr.flex8 = 5;
9422 					log.u_bbr.pkts_out = rsm->r_flags;
9423 					log.u_bbr.bbr_state = rack->rc_suspicious;
9424 					log.u_bbr.bbr_substate = rsm->r_just_ret;
9425 					log.u_bbr.timeStamp = tcp_get_usecs(&tv);
9426 					log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
9427 					TCP_LOG_EVENTP(rack->rc_tp, NULL,
9428 						       &rack->rc_inp->inp_socket->so_rcv,
9429 						       &rack->rc_inp->inp_socket->so_snd,
9430 						       TCP_SAD_DETECTION, 0,
9431 						       0, &log, false, &tv);
9432 				}
9433 			}
9434 			/* You loose some ack count every time you sack
9435 			 * a small bit that is not butting to the end of
9436 			 * what we have sent. This is because we never
9437 			 * send small bits unless its the end of the sb.
9438 			 * Anyone sending a sack that is not at the end
9439 			 * is thus very very suspicious.
9440 			 */
9441 			loss = (segsiz/2) / (end - start);
9442 			if (loss < rack->r_ctl.ack_count)
9443 				rack->r_ctl.ack_count -= loss;
9444 			else
9445 				rack->r_ctl.ack_count = 0;
9446 		}
9447 	}
9448 	first_time_through = 0;
9449 #endif
9450 	/* Ok we have an ACK for some piece of this rsm */
9451 	if (rsm->r_start != start) {
9452 		if ((rsm->r_flags & RACK_ACKED) == 0) {
9453 			/*
9454 			 * Before any splitting or hookery is
9455 			 * done is it a TLP of interest i.e. rxt?
9456 			 */
9457 			if ((rsm->r_flags & RACK_TLP) &&
9458 			    (rsm->r_rtr_cnt > 1)) {
9459 				/*
9460 				 * We are splitting a rxt TLP, check
9461 				 * if we need to save off the start/end
9462 				 */
9463 				if (rack->rc_last_tlp_acked_set &&
9464 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
9465 					/*
9466 					 * We already turned this on since we are inside
9467 					 * the previous one was a partially sack now we
9468 					 * are getting another one (maybe all of it).
9469 					 *
9470 					 */
9471 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
9472 					/*
9473 					 * Lets make sure we have all of it though.
9474 					 */
9475 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
9476 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9477 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9478 								     rack->r_ctl.last_tlp_acked_end);
9479 					}
9480 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
9481 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9482 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9483 								     rack->r_ctl.last_tlp_acked_end);
9484 					}
9485 				} else {
9486 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9487 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9488 					rack->rc_last_tlp_past_cumack = 0;
9489 					rack->rc_last_tlp_acked_set = 1;
9490 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
9491 				}
9492 			}
9493 			/**
9494 			 * Need to split this in two pieces the before and after,
9495 			 * the before remains in the map, the after must be
9496 			 * added. In other words we have:
9497 			 * rsm        |--------------|
9498 			 * sackblk        |------->
9499 			 * rsm will become
9500 			 *     rsm    |---|
9501 			 * and nrsm will be  the sacked piece
9502 			 *     nrsm       |----------|
9503 			 *
9504 			 * But before we start down that path lets
9505 			 * see if the sack spans over on top of
9506 			 * the next guy and it is already sacked.
9507 			 *
9508 			 */
9509 			/*
9510 			 * Hookery can only be used if the two entries
9511 			 * are in the same bucket and neither one of
9512 			 * them staddle the bucket line.
9513 			 */
9514 			next = tqhash_next(rack->r_ctl.tqh, rsm);
9515 			if (next &&
9516 			    (rsm->bindex == next->bindex) &&
9517 			    ((rsm->r_flags & RACK_STRADDLE) == 0) &&
9518 			    ((next->r_flags & RACK_STRADDLE) == 0) &&
9519 			    (rsm->r_flags & RACK_IN_GP_WIN) &&
9520 			    (next->r_flags & RACK_IN_GP_WIN))
9521 				can_use_hookery = 1;
9522 			else if (next &&
9523 				 (rsm->bindex == next->bindex) &&
9524 				 ((rsm->r_flags & RACK_STRADDLE) == 0) &&
9525 				 ((next->r_flags & RACK_STRADDLE) == 0) &&
9526 				 ((rsm->r_flags & RACK_IN_GP_WIN) == 0) &&
9527 				 ((next->r_flags & RACK_IN_GP_WIN) == 0))
9528 				can_use_hookery = 1;
9529 			else
9530 				can_use_hookery = 0;
9531 			if (next && can_use_hookery &&
9532 			    (next->r_flags & RACK_ACKED) &&
9533 			    SEQ_GEQ(end, next->r_start)) {
9534 				/**
9535 				 * So the next one is already acked, and
9536 				 * we can thus by hookery use our stack_map
9537 				 * to reflect the piece being sacked and
9538 				 * then adjust the two tree entries moving
9539 				 * the start and ends around. So we start like:
9540 				 *  rsm     |------------|             (not-acked)
9541 				 *  next                 |-----------| (acked)
9542 				 *  sackblk        |-------->
9543 				 *  We want to end like so:
9544 				 *  rsm     |------|                   (not-acked)
9545 				 *  next           |-----------------| (acked)
9546 				 *  nrsm           |-----|
9547 				 * Where nrsm is a temporary stack piece we
9548 				 * use to update all the gizmos.
9549 				 */
9550 				/* Copy up our fudge block */
9551 				noextra++;
9552 				nrsm = &stack_map;
9553 				memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
9554 				/* Now adjust our tree blocks */
9555 				rsm->r_end = start;
9556 				next->r_start = start;
9557  				rsm->r_flags |= RACK_SHUFFLED;
9558 				next->r_flags |= RACK_SHUFFLED;
9559 				/* Now we must adjust back where next->m is */
9560 				rack_setup_offset_for_rsm(rack, rsm, next);
9561 				/*
9562 				 * Which timestamp do we keep? It is rather
9563 				 * important in GP measurements to have the
9564 				 * accurate end of the send window.
9565 				 *
9566 				 * We keep the largest value, which is the newest
9567 				 * send. We do this in case a segment that is
9568 				 * joined together and not part of a GP estimate
9569 				 * later gets expanded into the GP estimate.
9570 				 *
9571 				 * We prohibit the merging of unlike kinds i.e.
9572 				 * all pieces that are in the GP estimate can be
9573 				 * merged and all pieces that are not in a GP estimate
9574 				 * can be merged, but not disimilar pieces. Combine
9575 				 * this with taking the highest here and we should
9576 				 * be ok unless of course the client reneges. Then
9577 				 * all bets are off.
9578 				 */
9579 				if (next->r_tim_lastsent[(next->r_rtr_cnt-1)] <
9580 				    nrsm->r_tim_lastsent[(nrsm->r_rtr_cnt-1)])
9581 					next->r_tim_lastsent[(next->r_rtr_cnt-1)] = nrsm->r_tim_lastsent[(nrsm->r_rtr_cnt-1)];
9582 				/*
9583 				 * And we must keep the newest ack arrival time.
9584 				 */
9585 				if (next->r_ack_arrival <
9586 				    rack_to_usec_ts(&rack->r_ctl.act_rcv_time))
9587 					next->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
9588 
9589 
9590 				/* We don't need to adjust rsm, it did not change */
9591 				/* Clear out the dup ack count of the remainder */
9592 				rsm->r_dupack = 0;
9593 				rsm->r_just_ret = 0;
9594 				rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
9595 				/* Now lets make sure our fudge block is right */
9596 				nrsm->r_start = start;
9597 				/* Now lets update all the stats and such */
9598 				rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
9599 				if (rack->app_limited_needs_set)
9600 					rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
9601 				changed += (nrsm->r_end - nrsm->r_start);
9602 				/* You get a count for acking a whole segment or more */
9603 				if ((nrsm->r_end - nrsm->r_start) >= segsiz)
9604 					rack->r_ctl.ack_count += ((nrsm->r_end - nrsm->r_start) / segsiz);
9605 				rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
9606 				if (nrsm->r_flags & RACK_SACK_PASSED) {
9607 					rack->r_ctl.rc_reorder_ts = cts;
9608 					if (rack->r_ctl.rc_reorder_ts == 0)
9609 						rack->r_ctl.rc_reorder_ts = 1;
9610 				}
9611 				/*
9612 				 * Now we want to go up from rsm (the
9613 				 * one left un-acked) to the next one
9614 				 * in the tmap. We do this so when
9615 				 * we walk backwards we include marking
9616 				 * sack-passed on rsm (The one passed in
9617 				 * is skipped since it is generally called
9618 				 * on something sacked before removing it
9619 				 * from the tmap).
9620 				 */
9621 				if (rsm->r_in_tmap) {
9622 					nrsm = TAILQ_NEXT(rsm, r_tnext);
9623 					/*
9624 					 * Now that we have the next
9625 					 * one walk backwards from there.
9626 					 */
9627 					if (nrsm && nrsm->r_in_tmap)
9628 						rack_log_sack_passed(tp, rack, nrsm);
9629 				}
9630 				/* Now are we done? */
9631 				if (SEQ_LT(end, next->r_end) ||
9632 				    (end == next->r_end)) {
9633 					/* Done with block */
9634 					goto out;
9635 				}
9636 				rack_log_map_chg(tp, rack, &stack_map, rsm, next, MAP_SACK_M1, end, __LINE__);
9637 				counter_u64_add(rack_sack_used_next_merge, 1);
9638 				/* Postion for the next block */
9639 				start = next->r_end;
9640 				rsm = tqhash_next(rack->r_ctl.tqh, next);
9641 				if (rsm == NULL)
9642 					goto out;
9643 			} else {
9644 				/**
9645 				 * We can't use any hookery here, so we
9646 				 * need to split the map. We enter like
9647 				 * so:
9648 				 *  rsm      |--------|
9649 				 *  sackblk       |----->
9650 				 * We will add the new block nrsm and
9651 				 * that will be the new portion, and then
9652 				 * fall through after reseting rsm. So we
9653 				 * split and look like this:
9654 				 *  rsm      |----|
9655 				 *  sackblk       |----->
9656 				 *  nrsm          |---|
9657 				 * We then fall through reseting
9658 				 * rsm to nrsm, so the next block
9659 				 * picks it up.
9660 				 */
9661 				nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
9662 				if (nrsm == NULL) {
9663 					/*
9664 					 * failed XXXrrs what can we do but loose the sack
9665 					 * info?
9666 					 */
9667 					goto out;
9668 				}
9669 				counter_u64_add(rack_sack_splits, 1);
9670 				rack_clone_rsm(rack, nrsm, rsm, start);
9671 				moved++;
9672 				rsm->r_just_ret = 0;
9673 #ifndef INVARIANTS
9674 				(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
9675 #else
9676 				if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
9677 					panic("Insert in rb tree of %p fails ret:%d rack:%p rsm:%p",
9678 					      nrsm, insret, rack, rsm);
9679 				}
9680 #endif
9681 				if (rsm->r_in_tmap) {
9682 					TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
9683 					nrsm->r_in_tmap = 1;
9684 				}
9685 				rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SACK_M2, end, __LINE__);
9686 				rsm->r_flags &= (~RACK_HAS_FIN);
9687 				/* Position us to point to the new nrsm that starts the sack blk */
9688 				rsm = nrsm;
9689 			}
9690 		} else {
9691 			/* Already sacked this piece */
9692 			counter_u64_add(rack_sack_skipped_acked, 1);
9693 			moved++;
9694 			if (end == rsm->r_end) {
9695 				/* Done with block */
9696 				rsm = tqhash_next(rack->r_ctl.tqh, rsm);
9697 				goto out;
9698 			} else if (SEQ_LT(end, rsm->r_end)) {
9699 				/* A partial sack to a already sacked block */
9700 				moved++;
9701 				rsm = tqhash_next(rack->r_ctl.tqh, rsm);
9702 				goto out;
9703 			} else {
9704 				/*
9705 				 * The end goes beyond this guy
9706 				 * reposition the start to the
9707 				 * next block.
9708 				 */
9709 				start = rsm->r_end;
9710 				rsm = tqhash_next(rack->r_ctl.tqh, rsm);
9711 				if (rsm == NULL)
9712 					goto out;
9713 			}
9714 		}
9715 	}
9716 	if (SEQ_GEQ(end, rsm->r_end)) {
9717 		/**
9718 		 * The end of this block is either beyond this guy or right
9719 		 * at this guy. I.e.:
9720 		 *  rsm ---                 |-----|
9721 		 *  end                     |-----|
9722 		 *  <or>
9723 		 *  end                     |---------|
9724 		 */
9725 		if ((rsm->r_flags & RACK_ACKED) == 0) {
9726 			/*
9727 			 * Is it a TLP of interest?
9728 			 */
9729 			if ((rsm->r_flags & RACK_TLP) &&
9730 			    (rsm->r_rtr_cnt > 1)) {
9731 				/*
9732 				 * We are splitting a rxt TLP, check
9733 				 * if we need to save off the start/end
9734 				 */
9735 				if (rack->rc_last_tlp_acked_set &&
9736 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
9737 					/*
9738 					 * We already turned this on since we are inside
9739 					 * the previous one was a partially sack now we
9740 					 * are getting another one (maybe all of it).
9741 					 */
9742 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
9743 					/*
9744 					 * Lets make sure we have all of it though.
9745 					 */
9746 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
9747 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9748 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9749 								     rack->r_ctl.last_tlp_acked_end);
9750 					}
9751 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
9752 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9753 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9754 								     rack->r_ctl.last_tlp_acked_end);
9755 					}
9756 				} else {
9757 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9758 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9759 					rack->rc_last_tlp_past_cumack = 0;
9760 					rack->rc_last_tlp_acked_set = 1;
9761 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
9762 				}
9763 			}
9764 			rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
9765 			changed += (rsm->r_end - rsm->r_start);
9766 			/* You get a count for acking a whole segment or more */
9767 			if ((rsm->r_end - rsm->r_start) >= segsiz)
9768 				rack->r_ctl.ack_count += ((rsm->r_end - rsm->r_start) / segsiz);
9769 			rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
9770 			if (rsm->r_in_tmap) /* should be true */
9771 				rack_log_sack_passed(tp, rack, rsm);
9772 			/* Is Reordering occuring? */
9773 			if (rsm->r_flags & RACK_SACK_PASSED) {
9774 				rsm->r_flags &= ~RACK_SACK_PASSED;
9775 				rack->r_ctl.rc_reorder_ts = cts;
9776 				if (rack->r_ctl.rc_reorder_ts == 0)
9777 					rack->r_ctl.rc_reorder_ts = 1;
9778 			}
9779 			if (rack->app_limited_needs_set)
9780 				rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
9781 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
9782 			rsm->r_flags |= RACK_ACKED;
9783 			if (rsm->r_in_tmap) {
9784 				TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
9785 				rsm->r_in_tmap = 0;
9786 			}
9787 			rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_SACK_M3, end, __LINE__);
9788 		} else {
9789 			counter_u64_add(rack_sack_skipped_acked, 1);
9790 			moved++;
9791 		}
9792 		if (end == rsm->r_end) {
9793 			/* This block only - done, setup for next */
9794 			goto out;
9795 		}
9796 		/*
9797 		 * There is more not coverend by this rsm move on
9798 		 * to the next block in the RB tree.
9799 		 */
9800 		nrsm = tqhash_next(rack->r_ctl.tqh, rsm);
9801 		start = rsm->r_end;
9802 		rsm = nrsm;
9803 		if (rsm == NULL)
9804 			goto out;
9805 		goto do_rest_ofb;
9806 	}
9807 	/**
9808 	 * The end of this sack block is smaller than
9809 	 * our rsm i.e.:
9810 	 *  rsm ---                 |-----|
9811 	 *  end                     |--|
9812 	 */
9813 	if ((rsm->r_flags & RACK_ACKED) == 0) {
9814 		/*
9815 		 * Is it a TLP of interest?
9816 		 */
9817 		if ((rsm->r_flags & RACK_TLP) &&
9818 		    (rsm->r_rtr_cnt > 1)) {
9819 			/*
9820 			 * We are splitting a rxt TLP, check
9821 			 * if we need to save off the start/end
9822 			 */
9823 			if (rack->rc_last_tlp_acked_set &&
9824 			    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
9825 				/*
9826 				 * We already turned this on since we are inside
9827 				 * the previous one was a partially sack now we
9828 				 * are getting another one (maybe all of it).
9829 				 */
9830 				rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
9831 				/*
9832 				 * Lets make sure we have all of it though.
9833 				 */
9834 				if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
9835 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9836 					rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9837 							     rack->r_ctl.last_tlp_acked_end);
9838 				}
9839 				if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
9840 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9841 					rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9842 							     rack->r_ctl.last_tlp_acked_end);
9843 				}
9844 			} else {
9845 				rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9846 				rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9847 				rack->rc_last_tlp_past_cumack = 0;
9848 				rack->rc_last_tlp_acked_set = 1;
9849 				rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
9850 			}
9851 		}
9852 		/*
9853 		 * Hookery can only be used if the two entries
9854 		 * are in the same bucket and neither one of
9855 		 * them staddle the bucket line.
9856 		 */
9857 		prev = tqhash_prev(rack->r_ctl.tqh, rsm);
9858 		if (prev &&
9859 		    (rsm->bindex == prev->bindex) &&
9860 		    ((rsm->r_flags & RACK_STRADDLE) == 0) &&
9861 		    ((prev->r_flags & RACK_STRADDLE) == 0) &&
9862 		    (rsm->r_flags & RACK_IN_GP_WIN) &&
9863 		    (prev->r_flags & RACK_IN_GP_WIN))
9864 			can_use_hookery = 1;
9865 		else if (prev &&
9866 			 (rsm->bindex == prev->bindex) &&
9867 			 ((rsm->r_flags & RACK_STRADDLE) == 0) &&
9868 			 ((prev->r_flags & RACK_STRADDLE) == 0) &&
9869 			 ((rsm->r_flags & RACK_IN_GP_WIN) == 0) &&
9870 			 ((prev->r_flags & RACK_IN_GP_WIN) == 0))
9871 			can_use_hookery = 1;
9872 		else
9873 			can_use_hookery = 0;
9874 
9875 		if (prev && can_use_hookery &&
9876 		    (prev->r_flags & RACK_ACKED)) {
9877 			/**
9878 			 * Goal, we want the right remainder of rsm to shrink
9879 			 * in place and span from (rsm->r_start = end) to rsm->r_end.
9880 			 * We want to expand prev to go all the way
9881 			 * to prev->r_end <- end.
9882 			 * so in the tree we have before:
9883 			 *   prev     |--------|         (acked)
9884 			 *   rsm               |-------| (non-acked)
9885 			 *   sackblk           |-|
9886 			 * We churn it so we end up with
9887 			 *   prev     |----------|       (acked)
9888 			 *   rsm                 |-----| (non-acked)
9889 			 *   nrsm              |-| (temporary)
9890 			 *
9891 			 * Note if either prev/rsm is a TLP we don't
9892 			 * do this.
9893 			 */
9894 			noextra++;
9895 			nrsm = &stack_map;
9896 			memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
9897 			prev->r_end = end;
9898 			rsm->r_start = end;
9899 			rsm->r_flags |= RACK_SHUFFLED;
9900 			prev->r_flags |= RACK_SHUFFLED;
9901 			/* Now adjust nrsm (stack copy) to be
9902 			 * the one that is the small
9903 			 * piece that was "sacked".
9904 			 */
9905 			nrsm->r_end = end;
9906 			rsm->r_dupack = 0;
9907 			/*
9908 			 * Which timestamp do we keep? It is rather
9909 			 * important in GP measurements to have the
9910 			 * accurate end of the send window.
9911 			 *
9912 			 * We keep the largest value, which is the newest
9913 			 * send. We do this in case a segment that is
9914 			 * joined together and not part of a GP estimate
9915 			 * later gets expanded into the GP estimate.
9916 			 *
9917 			 * We prohibit the merging of unlike kinds i.e.
9918 			 * all pieces that are in the GP estimate can be
9919 			 * merged and all pieces that are not in a GP estimate
9920 			 * can be merged, but not disimilar pieces. Combine
9921 			 * this with taking the highest here and we should
9922 			 * be ok unless of course the client reneges. Then
9923 			 * all bets are off.
9924 			 */
9925 			if(prev->r_tim_lastsent[(prev->r_rtr_cnt-1)] <
9926 			   nrsm->r_tim_lastsent[(nrsm->r_rtr_cnt-1)]) {
9927 				prev->r_tim_lastsent[(prev->r_rtr_cnt-1)] = nrsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
9928 			}
9929 			/*
9930 			 * And we must keep the newest ack arrival time.
9931 			 */
9932 
9933 			if(prev->r_ack_arrival <
9934 			   rack_to_usec_ts(&rack->r_ctl.act_rcv_time))
9935 				prev->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
9936 
9937 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
9938 			/*
9939 			 * Now that the rsm has had its start moved forward
9940 			 * lets go ahead and get its new place in the world.
9941 			 */
9942 			rack_setup_offset_for_rsm(rack, prev, rsm);
9943 			/*
9944 			 * Now nrsm is our new little piece
9945 			 * that is acked (which was merged
9946 			 * to prev). Update the rtt and changed
9947 			 * based on that. Also check for reordering.
9948 			 */
9949 			rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
9950 			if (rack->app_limited_needs_set)
9951 				rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
9952 			changed += (nrsm->r_end - nrsm->r_start);
9953 			/* You get a count for acking a whole segment or more */
9954 			if ((nrsm->r_end - nrsm->r_start) >= segsiz)
9955 				rack->r_ctl.ack_count += ((nrsm->r_end - nrsm->r_start) / segsiz);
9956 
9957 			rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
9958 			if (nrsm->r_flags & RACK_SACK_PASSED) {
9959 				rack->r_ctl.rc_reorder_ts = cts;
9960 				if (rack->r_ctl.rc_reorder_ts == 0)
9961 					rack->r_ctl.rc_reorder_ts = 1;
9962 			}
9963 			rack_log_map_chg(tp, rack, prev, &stack_map, rsm, MAP_SACK_M4, end, __LINE__);
9964 			rsm = prev;
9965 			counter_u64_add(rack_sack_used_prev_merge, 1);
9966 		} else {
9967 			/**
9968 			 * This is the case where our previous
9969 			 * block is not acked either, so we must
9970 			 * split the block in two.
9971 			 */
9972 			nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
9973 			if (nrsm == NULL) {
9974 				/* failed rrs what can we do but loose the sack info? */
9975 				goto out;
9976 			}
9977 			if ((rsm->r_flags & RACK_TLP) &&
9978 			    (rsm->r_rtr_cnt > 1)) {
9979 				/*
9980 				 * We are splitting a rxt TLP, check
9981 				 * if we need to save off the start/end
9982 				 */
9983 				if (rack->rc_last_tlp_acked_set &&
9984 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
9985 					/*
9986 					 * We already turned this on since this block is inside
9987 					 * the previous one was a partially sack now we
9988 					 * are getting another one (maybe all of it).
9989 					 */
9990 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
9991 					/*
9992 					 * Lets make sure we have all of it though.
9993 					 */
9994 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
9995 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9996 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9997 								     rack->r_ctl.last_tlp_acked_end);
9998 					}
9999 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
10000 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
10001 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
10002 								     rack->r_ctl.last_tlp_acked_end);
10003 					}
10004 				} else {
10005 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
10006 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
10007 					rack->rc_last_tlp_acked_set = 1;
10008 					rack->rc_last_tlp_past_cumack = 0;
10009 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
10010 				}
10011 			}
10012 			/**
10013 			 * In this case nrsm becomes
10014 			 * nrsm->r_start = end;
10015 			 * nrsm->r_end = rsm->r_end;
10016 			 * which is un-acked.
10017 			 * <and>
10018 			 * rsm->r_end = nrsm->r_start;
10019 			 * i.e. the remaining un-acked
10020 			 * piece is left on the left
10021 			 * hand side.
10022 			 *
10023 			 * So we start like this
10024 			 * rsm      |----------| (not acked)
10025 			 * sackblk  |---|
10026 			 * build it so we have
10027 			 * rsm      |---|         (acked)
10028 			 * nrsm         |------|  (not acked)
10029 			 */
10030 			counter_u64_add(rack_sack_splits, 1);
10031 			rack_clone_rsm(rack, nrsm, rsm, end);
10032 			moved++;
10033 			rsm->r_flags &= (~RACK_HAS_FIN);
10034 			rsm->r_just_ret = 0;
10035 #ifndef INVARIANTS
10036 			(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
10037 #else
10038 			if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
10039 				panic("Insert in rb tree of %p fails ret:% rack:%p rsm:%p",
10040 				      nrsm, insret, rack, rsm);
10041 			}
10042 #endif
10043 			if (rsm->r_in_tmap) {
10044 				TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
10045 				nrsm->r_in_tmap = 1;
10046 			}
10047 			nrsm->r_dupack = 0;
10048 			rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
10049 			rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
10050 			changed += (rsm->r_end - rsm->r_start);
10051 			/* You get a count for acking a whole segment or more */
10052 			if ((rsm->r_end - rsm->r_start) >= segsiz)
10053 				rack->r_ctl.ack_count += ((rsm->r_end - rsm->r_start) / segsiz);
10054 
10055 			rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
10056 			if (rsm->r_in_tmap) /* should be true */
10057 				rack_log_sack_passed(tp, rack, rsm);
10058 			/* Is Reordering occuring? */
10059 			if (rsm->r_flags & RACK_SACK_PASSED) {
10060 				rsm->r_flags &= ~RACK_SACK_PASSED;
10061 				rack->r_ctl.rc_reorder_ts = cts;
10062 				if (rack->r_ctl.rc_reorder_ts == 0)
10063 					rack->r_ctl.rc_reorder_ts = 1;
10064 			}
10065 			if (rack->app_limited_needs_set)
10066 				rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
10067 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
10068 			rsm->r_flags |= RACK_ACKED;
10069 			rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SACK_M5, end, __LINE__);
10070 			if (rsm->r_in_tmap) {
10071 				TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
10072 				rsm->r_in_tmap = 0;
10073 			}
10074 		}
10075 	} else if (start != end){
10076 		/*
10077 		 * The block was already acked.
10078 		 */
10079 		counter_u64_add(rack_sack_skipped_acked, 1);
10080 		moved++;
10081 	}
10082 out:
10083 	if (rsm &&
10084 	    ((rsm->r_flags & RACK_TLP) == 0) &&
10085 	    (rsm->r_flags & RACK_ACKED)) {
10086 		/*
10087 		 * Now can we merge where we worked
10088 		 * with either the previous or
10089 		 * next block?
10090 		 */
10091 		next = tqhash_next(rack->r_ctl.tqh, rsm);
10092 		while (next) {
10093 			if (next->r_flags & RACK_TLP)
10094 				break;
10095 			/* Only allow merges between ones in or out of GP window */
10096 			if ((next->r_flags & RACK_IN_GP_WIN) &&
10097 			    ((rsm->r_flags & RACK_IN_GP_WIN) == 0)) {
10098 				break;
10099 			}
10100 			if ((rsm->r_flags & RACK_IN_GP_WIN) &&
10101 			    ((next->r_flags & RACK_IN_GP_WIN) == 0)) {
10102 				break;
10103 			}
10104 			if (rsm->bindex != next->bindex)
10105 				break;
10106 			if (rsm->r_flags & RACK_STRADDLE)
10107 				break;
10108 			if (next->r_flags & RACK_STRADDLE)
10109 				break;
10110 			if (next->r_flags & RACK_ACKED) {
10111 				/* yep this and next can be merged */
10112 				rsm = rack_merge_rsm(rack, rsm, next);
10113 				noextra++;
10114 				next = tqhash_next(rack->r_ctl.tqh, rsm);
10115 			} else
10116 				break;
10117 		}
10118 		/* Now what about the previous? */
10119 		prev = tqhash_prev(rack->r_ctl.tqh, rsm);
10120 		while (prev) {
10121 			if (prev->r_flags & RACK_TLP)
10122 				break;
10123 			/* Only allow merges between ones in or out of GP window */
10124 			if ((prev->r_flags & RACK_IN_GP_WIN) &&
10125 			    ((rsm->r_flags & RACK_IN_GP_WIN) == 0)) {
10126 				break;
10127 			}
10128 			if ((rsm->r_flags & RACK_IN_GP_WIN) &&
10129 			    ((prev->r_flags & RACK_IN_GP_WIN) == 0)) {
10130 				break;
10131 			}
10132 			if (rsm->bindex != prev->bindex)
10133 				break;
10134 			if (rsm->r_flags & RACK_STRADDLE)
10135 				break;
10136 			if (prev->r_flags & RACK_STRADDLE)
10137 				break;
10138 			if (prev->r_flags & RACK_ACKED) {
10139 				/* yep the previous and this can be merged */
10140 				rsm = rack_merge_rsm(rack, prev, rsm);
10141 				noextra++;
10142 				prev = tqhash_prev(rack->r_ctl.tqh, rsm);
10143 			} else
10144 				break;
10145 		}
10146 	}
10147 	if (used_ref == 0) {
10148 		counter_u64_add(rack_sack_proc_all, 1);
10149 	} else {
10150 		counter_u64_add(rack_sack_proc_short, 1);
10151 	}
10152 	/* Save off the next one for quick reference. */
10153 	nrsm = tqhash_find(rack->r_ctl.tqh, end);
10154 	*prsm = rack->r_ctl.rc_sacklast = nrsm;
10155 	/* Pass back the moved. */
10156 	*moved_two = moved;
10157 	*no_extra = noextra;
10158 	return (changed);
10159 }
10160 
10161 static void inline
10162 rack_peer_reneges(struct tcp_rack *rack, struct rack_sendmap *rsm, tcp_seq th_ack)
10163 {
10164 	struct rack_sendmap *tmap;
10165 
10166 	tmap = NULL;
10167 	while (rsm && (rsm->r_flags & RACK_ACKED)) {
10168 		/* Its no longer sacked, mark it so */
10169 		rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
10170 #ifdef INVARIANTS
10171 		if (rsm->r_in_tmap) {
10172 			panic("rack:%p rsm:%p flags:0x%x in tmap?",
10173 			      rack, rsm, rsm->r_flags);
10174 		}
10175 #endif
10176 		rsm->r_flags &= ~(RACK_ACKED|RACK_SACK_PASSED|RACK_WAS_SACKPASS);
10177 		/* Rebuild it into our tmap */
10178 		if (tmap == NULL) {
10179 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
10180 			tmap = rsm;
10181 		} else {
10182 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, tmap, rsm, r_tnext);
10183 			tmap = rsm;
10184 		}
10185 		tmap->r_in_tmap = 1;
10186 		rsm = tqhash_next(rack->r_ctl.tqh, rsm);
10187 	}
10188 	/*
10189 	 * Now lets possibly clear the sack filter so we start
10190 	 * recognizing sacks that cover this area.
10191 	 */
10192 	sack_filter_clear(&rack->r_ctl.rack_sf, th_ack);
10193 
10194 }
10195 
10196 static void
10197 rack_do_decay(struct tcp_rack *rack)
10198 {
10199 	struct timeval res;
10200 
10201 #define	timersub(tvp, uvp, vvp)						\
10202 	do {								\
10203 		(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;		\
10204 		(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;	\
10205 		if ((vvp)->tv_usec < 0) {				\
10206 			(vvp)->tv_sec--;				\
10207 			(vvp)->tv_usec += 1000000;			\
10208 		}							\
10209 	} while (0)
10210 
10211 	timersub(&rack->r_ctl.act_rcv_time, &rack->r_ctl.rc_last_time_decay, &res);
10212 #undef timersub
10213 
10214 	rack->r_ctl.input_pkt++;
10215 	if ((rack->rc_in_persist) ||
10216 	    (res.tv_sec >= 1) ||
10217 	    (rack->rc_tp->snd_max == rack->rc_tp->snd_una)) {
10218 		/*
10219 		 * Check for decay of non-SAD,
10220 		 * we want all SAD detection metrics to
10221 		 * decay 1/4 per second (or more) passed.
10222 		 * Current default is 800 so it decays
10223 		 * 80% every second.
10224 		 */
10225 #ifdef TCP_SAD_DETECTION
10226 		uint32_t pkt_delta;
10227 
10228 		pkt_delta = rack->r_ctl.input_pkt - rack->r_ctl.saved_input_pkt;
10229 #endif
10230 		/* Update our saved tracking values */
10231 		rack->r_ctl.saved_input_pkt = rack->r_ctl.input_pkt;
10232 		rack->r_ctl.rc_last_time_decay = rack->r_ctl.act_rcv_time;
10233 		/* Now do we escape without decay? */
10234 #ifdef TCP_SAD_DETECTION
10235 		if (rack->rc_in_persist ||
10236 		    (rack->rc_tp->snd_max == rack->rc_tp->snd_una) ||
10237 		    (pkt_delta < tcp_sad_low_pps)){
10238 			/*
10239 			 * We don't decay idle connections
10240 			 * or ones that have a low input pps.
10241 			 */
10242 			return;
10243 		}
10244 		/* Decay the counters */
10245 		rack->r_ctl.ack_count = ctf_decay_count(rack->r_ctl.ack_count,
10246 							tcp_sad_decay_val);
10247 		rack->r_ctl.sack_count = ctf_decay_count(rack->r_ctl.sack_count,
10248 							 tcp_sad_decay_val);
10249 		rack->r_ctl.sack_moved_extra = ctf_decay_count(rack->r_ctl.sack_moved_extra,
10250 							       tcp_sad_decay_val);
10251 		rack->r_ctl.sack_noextra_move = ctf_decay_count(rack->r_ctl.sack_noextra_move,
10252 								tcp_sad_decay_val);
10253 #endif
10254 	}
10255 }
10256 
10257 static void inline
10258 rack_rsm_sender_update(struct tcp_rack *rack, struct tcpcb *tp, struct rack_sendmap *rsm, uint8_t from)
10259 {
10260 	/*
10261 	 * We look at advancing the end send time for our GP
10262 	 * measurement tracking only as the cumulative acknowledgment
10263 	 * moves forward. You might wonder about this, why not
10264 	 * at every transmission or retransmission within the
10265 	 * GP window update the rc_gp_cumack_ts? Well its rather
10266 	 * nuanced but basically the GP window *may* expand (as
10267 	 * it does below) or worse and harder to track it may shrink.
10268 	 *
10269 	 * This last makes it impossible to track at the time of
10270 	 * the send, since you may set forward your rc_gp_cumack_ts
10271 	 * when you send, because that send *is* in your currently
10272 	 * "guessed" window, but then it shrinks. Now which was
10273 	 * the send time of the last bytes in the window, by the
10274 	 * time you ask that question that part of the sendmap
10275 	 * is freed. So you don't know and you will have too
10276 	 * long of send window. Instead by updating the time
10277 	 * marker only when the cumack advances this assures us
10278 	 * that we will have only the sends in the window of our
10279 	 * GP measurement.
10280 	 *
10281 	 * Another complication from this is the
10282 	 * merging of sendmap entries. During SACK processing this
10283 	 * can happen to conserve the sendmap size. That breaks
10284 	 * everything down in tracking the send window of the GP
10285 	 * estimate. So to prevent that and keep it working with
10286 	 * a tiny bit more limited merging, we only allow like
10287 	 * types to be merged. I.e. if two sends are in the GP window
10288 	 * then its ok to merge them together. If two sends are not
10289 	 * in the GP window its ok to merge them together too. Though
10290 	 * one send in and one send out cannot be merged. We combine
10291 	 * this with never allowing the shrinking of the GP window when
10292 	 * we are in recovery so that we can properly calculate the
10293 	 * sending times.
10294 	 *
10295 	 * This all of course seems complicated, because it is.. :)
10296 	 *
10297 	 * The cum-ack is being advanced upon the sendmap.
10298 	 * If we are not doing a GP estimate don't
10299 	 * proceed.
10300 	 */
10301 	uint64_t ts;
10302 
10303 	if ((tp->t_flags & TF_GPUTINPROG) == 0)
10304 		return;
10305 	/*
10306 	 * If this sendmap entry is going
10307 	 * beyond the measurement window we had picked,
10308 	 * expand the measurement window by that much.
10309 	 */
10310 	if (SEQ_GT(rsm->r_end, tp->gput_ack)) {
10311 		tp->gput_ack = rsm->r_end;
10312 	}
10313 	/*
10314 	 * If we have not setup a ack, then we
10315 	 * have no idea if the newly acked pieces
10316 	 * will be "in our seq measurement range". If
10317 	 * it is when we clear the app_limited_needs_set
10318 	 * flag the timestamp will be updated.
10319 	 */
10320 	if (rack->app_limited_needs_set)
10321 		return;
10322 	/*
10323 	 * Finally, we grab out the latest timestamp
10324 	 * that this packet was sent and then see
10325 	 * if:
10326 	 *  a) The packet touches are newly defined GP range.
10327 	 *  b) The time is greater than (newer) than the
10328 	 *     one we currently have. If so we update
10329 	 *     our sending end time window.
10330 	 *
10331 	 * Note we *do not* do this at send time. The reason
10332 	 * is that if you do you *may* pick up a newer timestamp
10333 	 * for a range you are not going to measure. We project
10334 	 * out how far and then sometimes modify that to be
10335 	 * smaller. If that occurs then you will have a send
10336 	 * that does not belong to the range included.
10337 	 */
10338 	if ((ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]) <=
10339 	    rack->r_ctl.rc_gp_cumack_ts)
10340 		return;
10341 	if (rack_in_gp_window(tp, rsm)) {
10342 		rack->r_ctl.rc_gp_cumack_ts = ts;
10343 		rack_log_gpset(rack, tp->gput_ack, (uint32_t)ts, rsm->r_end,
10344 			       __LINE__, from, rsm);
10345 	}
10346 }
10347 
10348 static void
10349 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)
10350 {
10351 	struct rack_sendmap *rsm;
10352 	/*
10353 	 * The ACK point is advancing to th_ack, we must drop off
10354 	 * the packets in the rack log and calculate any eligble
10355 	 * RTT's.
10356 	 */
10357 
10358 	rack->r_wanted_output = 1;
10359 	if (SEQ_GT(th_ack, tp->snd_una))
10360 	    rack->r_ctl.last_cumack_advance = acktime;
10361 
10362 	/* Tend any TLP that has been marked for 1/2 the seq space (its old)  */
10363 	if ((rack->rc_last_tlp_acked_set == 1)&&
10364 	    (rack->rc_last_tlp_past_cumack == 1) &&
10365 	    (SEQ_GT(rack->r_ctl.last_tlp_acked_start, th_ack))) {
10366 		/*
10367 		 * We have reached the point where our last rack
10368 		 * tlp retransmit sequence is ahead of the cum-ack.
10369 		 * This can only happen when the cum-ack moves all
10370 		 * the way around (its been a full 2^^31+1 bytes
10371 		 * or more since we sent a retransmitted TLP). Lets
10372 		 * turn off the valid flag since its not really valid.
10373 		 *
10374 		 * Note since sack's also turn on this event we have
10375 		 * a complication, we have to wait to age it out until
10376 		 * the cum-ack is by the TLP before checking which is
10377 		 * what the next else clause does.
10378 		 */
10379 		rack_log_dsack_event(rack, 9, __LINE__,
10380 				     rack->r_ctl.last_tlp_acked_start,
10381 				     rack->r_ctl.last_tlp_acked_end);
10382 		rack->rc_last_tlp_acked_set = 0;
10383 		rack->rc_last_tlp_past_cumack = 0;
10384 	} else if ((rack->rc_last_tlp_acked_set == 1) &&
10385 		   (rack->rc_last_tlp_past_cumack == 0) &&
10386 		   (SEQ_GEQ(th_ack, rack->r_ctl.last_tlp_acked_end))) {
10387 		/*
10388 		 * It is safe to start aging TLP's out.
10389 		 */
10390 		rack->rc_last_tlp_past_cumack = 1;
10391 	}
10392 	/* We do the same for the tlp send seq as well */
10393 	if ((rack->rc_last_sent_tlp_seq_valid == 1) &&
10394 	    (rack->rc_last_sent_tlp_past_cumack == 1) &&
10395 	    (SEQ_GT(rack->r_ctl.last_sent_tlp_seq,  th_ack))) {
10396 		rack_log_dsack_event(rack, 9, __LINE__,
10397 				     rack->r_ctl.last_sent_tlp_seq,
10398 				     (rack->r_ctl.last_sent_tlp_seq +
10399 				      rack->r_ctl.last_sent_tlp_len));
10400 		rack->rc_last_sent_tlp_seq_valid = 0;
10401 		rack->rc_last_sent_tlp_past_cumack = 0;
10402 	} else if ((rack->rc_last_sent_tlp_seq_valid == 1) &&
10403 		   (rack->rc_last_sent_tlp_past_cumack == 0) &&
10404 		   (SEQ_GEQ(th_ack, rack->r_ctl.last_sent_tlp_seq))) {
10405 		/*
10406 		 * It is safe to start aging TLP's send.
10407 		 */
10408 		rack->rc_last_sent_tlp_past_cumack = 1;
10409 	}
10410 more:
10411 	rsm = tqhash_min(rack->r_ctl.tqh);
10412 	if (rsm == NULL) {
10413 		if ((th_ack - 1) == tp->iss) {
10414 			/*
10415 			 * For the SYN incoming case we will not
10416 			 * have called tcp_output for the sending of
10417 			 * the SYN, so there will be no map. All
10418 			 * other cases should probably be a panic.
10419 			 */
10420 			return;
10421 		}
10422 		if (tp->t_flags & TF_SENTFIN) {
10423 			/* if we sent a FIN we often will not have map */
10424 			return;
10425 		}
10426 #ifdef INVARIANTS
10427 		panic("No rack map tp:%p for state:%d ack:%u rack:%p snd_una:%u snd_max:%u snd_nxt:%u\n",
10428 		      tp,
10429 		      tp->t_state, th_ack, rack,
10430 		      tp->snd_una, tp->snd_max, tp->snd_nxt);
10431 #endif
10432 		return;
10433 	}
10434 	if (SEQ_LT(th_ack, rsm->r_start)) {
10435 		/* Huh map is missing this */
10436 #ifdef INVARIANTS
10437 		printf("Rack map starts at r_start:%u for th_ack:%u huh? ts:%d rs:%d\n",
10438 		       rsm->r_start,
10439 		       th_ack, tp->t_state, rack->r_state);
10440 #endif
10441 		return;
10442 	}
10443 	rack_update_rtt(tp, rack, rsm, to, cts, CUM_ACKED, th_ack);
10444 
10445 	/* Now was it a retransmitted TLP? */
10446 	if ((rsm->r_flags & RACK_TLP) &&
10447 	    (rsm->r_rtr_cnt > 1)) {
10448 		/*
10449 		 * Yes, this rsm was a TLP and retransmitted, remember that
10450 		 * since if a DSACK comes back on this we don't want
10451 		 * to think of it as a reordered segment. This may
10452 		 * get updated again with possibly even other TLPs
10453 		 * in flight, but thats ok. Only when we don't send
10454 		 * a retransmitted TLP for 1/2 the sequences space
10455 		 * will it get turned off (above).
10456 		 */
10457 		if (rack->rc_last_tlp_acked_set &&
10458 		    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
10459 			/*
10460 			 * We already turned this on since the end matches,
10461 			 * the previous one was a partially ack now we
10462 			 * are getting another one (maybe all of it).
10463 			 */
10464 			rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
10465 			/*
10466 			 * Lets make sure we have all of it though.
10467 			 */
10468 			if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
10469 				rack->r_ctl.last_tlp_acked_start = rsm->r_start;
10470 				rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
10471 						     rack->r_ctl.last_tlp_acked_end);
10472 			}
10473 			if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
10474 				rack->r_ctl.last_tlp_acked_end = rsm->r_end;
10475 				rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
10476 						     rack->r_ctl.last_tlp_acked_end);
10477 			}
10478 		} else {
10479 			rack->rc_last_tlp_past_cumack = 1;
10480 			rack->r_ctl.last_tlp_acked_start = rsm->r_start;
10481 			rack->r_ctl.last_tlp_acked_end = rsm->r_end;
10482 			rack->rc_last_tlp_acked_set = 1;
10483 			rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
10484 		}
10485 	}
10486 	/* Now do we consume the whole thing? */
10487 	if (SEQ_GEQ(th_ack, rsm->r_end)) {
10488 		/* Its all consumed. */
10489 		uint32_t left;
10490 		uint8_t newly_acked;
10491 
10492 		rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_FREE, rsm->r_end, __LINE__);
10493 		rack->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
10494 		rsm->r_rtr_bytes = 0;
10495 		/*
10496 		 * Record the time of highest cumack sent if its in our measurement
10497 		 * window and possibly bump out the end.
10498 		 */
10499 		rack_rsm_sender_update(rack, tp, rsm, 4);
10500 		tqhash_remove(rack->r_ctl.tqh, rsm, REMOVE_TYPE_CUMACK);
10501 		if (rsm->r_in_tmap) {
10502 			TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
10503 			rsm->r_in_tmap = 0;
10504 		}
10505 		newly_acked = 1;
10506 		if (rsm->r_flags & RACK_ACKED) {
10507 			/*
10508 			 * It was acked on the scoreboard -- remove
10509 			 * it from total
10510 			 */
10511 			rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
10512 			newly_acked = 0;
10513 		} else if (rsm->r_flags & RACK_SACK_PASSED) {
10514 			/*
10515 			 * There are segments ACKED on the
10516 			 * scoreboard further up. We are seeing
10517 			 * reordering.
10518 			 */
10519 			rsm->r_flags &= ~RACK_SACK_PASSED;
10520 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
10521 			rsm->r_flags |= RACK_ACKED;
10522 			rack->r_ctl.rc_reorder_ts = cts;
10523 			if (rack->r_ctl.rc_reorder_ts == 0)
10524 				rack->r_ctl.rc_reorder_ts = 1;
10525 			if (rack->r_ent_rec_ns) {
10526 				/*
10527 				 * We have sent no more, and we saw an sack
10528 				 * then ack arrive.
10529 				 */
10530 				rack->r_might_revert = 1;
10531 			}
10532 		}
10533 		if ((rsm->r_flags & RACK_TO_REXT) &&
10534 		    (tp->t_flags & TF_RCVD_TSTMP) &&
10535 		    (to->to_flags & TOF_TS) &&
10536 		    (to->to_tsecr != 0) &&
10537 		    (tp->t_flags & TF_PREVVALID)) {
10538 			/*
10539 			 * We can use the timestamp to see
10540 			 * if this retransmission was from the
10541 			 * first transmit. If so we made a mistake.
10542 			 */
10543 			tp->t_flags &= ~TF_PREVVALID;
10544 			if (to->to_tsecr == rack_ts_to_msec(rsm->r_tim_lastsent[0])) {
10545 				/* The first transmit is what this ack is for */
10546 				rack_cong_signal(tp, CC_RTO_ERR, th_ack, __LINE__);
10547 			}
10548 		}
10549 		left = th_ack - rsm->r_end;
10550 		if (rack->app_limited_needs_set && newly_acked)
10551 			rack_need_set_test(tp, rack, rsm, th_ack, __LINE__, RACK_USE_END_OR_THACK);
10552 		/* Free back to zone */
10553 		rack_free(rack, rsm);
10554 		if (left) {
10555 			goto more;
10556 		}
10557 		/* Check for reneging */
10558 		rsm = tqhash_min(rack->r_ctl.tqh);
10559 		if (rsm && (rsm->r_flags & RACK_ACKED) && (th_ack == rsm->r_start)) {
10560 			/*
10561 			 * The peer has moved snd_una up to
10562 			 * the edge of this send, i.e. one
10563 			 * that it had previously acked. The only
10564 			 * way that can be true if the peer threw
10565 			 * away data (space issues) that it had
10566 			 * previously sacked (else it would have
10567 			 * given us snd_una up to (rsm->r_end).
10568 			 * We need to undo the acked markings here.
10569 			 *
10570 			 * Note we have to look to make sure th_ack is
10571 			 * our rsm->r_start in case we get an old ack
10572 			 * where th_ack is behind snd_una.
10573 			 */
10574 			rack_peer_reneges(rack, rsm, th_ack);
10575 		}
10576 		return;
10577 	}
10578 	if (rsm->r_flags & RACK_ACKED) {
10579 		/*
10580 		 * It was acked on the scoreboard -- remove it from
10581 		 * total for the part being cum-acked.
10582 		 */
10583 		rack->r_ctl.rc_sacked -= (th_ack - rsm->r_start);
10584 	}
10585 	/*
10586 	 * Clear the dup ack count for
10587 	 * the piece that remains.
10588 	 */
10589 	rsm->r_dupack = 0;
10590 	rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
10591 	if (rsm->r_rtr_bytes) {
10592 		/*
10593 		 * It was retransmitted adjust the
10594 		 * sack holes for what was acked.
10595 		 */
10596 		int ack_am;
10597 
10598 		ack_am = (th_ack - rsm->r_start);
10599 		if (ack_am >= rsm->r_rtr_bytes) {
10600 			rack->r_ctl.rc_holes_rxt -= ack_am;
10601 			rsm->r_rtr_bytes -= ack_am;
10602 		}
10603 	}
10604 	/*
10605 	 * Update where the piece starts and record
10606 	 * the time of send of highest cumack sent if
10607 	 * its in our GP range.
10608 	 */
10609 	rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_TRIM_HEAD, th_ack, __LINE__);
10610 	/* Now we need to move our offset forward too */
10611 	if (rsm->m &&
10612 	    ((rsm->orig_m_len != rsm->m->m_len) ||
10613 	     (M_TRAILINGROOM(rsm->m) != rsm->orig_t_space))) {
10614 		/* Fix up the orig_m_len and possibly the mbuf offset */
10615 		rack_adjust_orig_mlen(rsm);
10616 	}
10617 	rsm->soff += (th_ack - rsm->r_start);
10618 	rack_rsm_sender_update(rack, tp, rsm, 5);
10619 	/* The trim will move th_ack into r_start for us */
10620 	tqhash_trim(rack->r_ctl.tqh, th_ack);
10621 	/* Now do we need to move the mbuf fwd too? */
10622 	if (rsm->m) {
10623 		while (rsm->soff >= rsm->m->m_len) {
10624 			rsm->soff -= rsm->m->m_len;
10625 			rsm->m = rsm->m->m_next;
10626 			KASSERT((rsm->m != NULL),
10627 				(" nrsm:%p hit at soff:%u null m",
10628 				 rsm, rsm->soff));
10629 		}
10630 		rsm->orig_m_len = rsm->m->m_len;
10631 		rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
10632 	}
10633 	if (rack->app_limited_needs_set &&
10634 	    SEQ_GEQ(th_ack, tp->gput_seq))
10635 		rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_BEG);
10636 }
10637 
10638 static void
10639 rack_handle_might_revert(struct tcpcb *tp, struct tcp_rack *rack)
10640 {
10641 	struct rack_sendmap *rsm;
10642 	int sack_pass_fnd = 0;
10643 
10644 	if (rack->r_might_revert) {
10645 		/*
10646 		 * Ok we have reordering, have not sent anything, we
10647 		 * might want to revert the congestion state if nothing
10648 		 * further has SACK_PASSED on it. Lets check.
10649 		 *
10650 		 * We also get here when we have DSACKs come in for
10651 		 * all the data that we FR'd. Note that a rxt or tlp
10652 		 * timer clears this from happening.
10653 		 */
10654 
10655 		TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
10656 			if (rsm->r_flags & RACK_SACK_PASSED) {
10657 				sack_pass_fnd = 1;
10658 				break;
10659 			}
10660 		}
10661 		if (sack_pass_fnd == 0) {
10662 			/*
10663 			 * We went into recovery
10664 			 * incorrectly due to reordering!
10665 			 */
10666 			int orig_cwnd;
10667 
10668 			rack->r_ent_rec_ns = 0;
10669 			orig_cwnd = tp->snd_cwnd;
10670 			tp->snd_ssthresh = rack->r_ctl.rc_ssthresh_at_erec;
10671 			tp->snd_recover = tp->snd_una;
10672 			rack_log_to_prr(rack, 14, orig_cwnd, __LINE__);
10673 			EXIT_RECOVERY(tp->t_flags);
10674 		}
10675 		rack->r_might_revert = 0;
10676 	}
10677 }
10678 
10679 #ifdef TCP_SAD_DETECTION
10680 
10681 static void
10682 rack_merge_out_sacks(struct tcp_rack *rack)
10683 {
10684 	struct rack_sendmap *cur, *next, *rsm, *trsm = NULL;
10685 
10686 	cur = tqhash_min(rack->r_ctl.tqh);
10687 	while(cur) {
10688 		next = tqhash_next(rack->r_ctl.tqh, cur);
10689 		/*
10690 		 * The idea is to go through all and merge back
10691 		 * together the pieces sent together,
10692 		 */
10693 		if ((next != NULL) &&
10694 		    (cur->r_tim_lastsent[0] == next->r_tim_lastsent[0])) {
10695 			rack_merge_rsm(rack, cur, next);
10696 		} else {
10697 			cur = next;
10698 		}
10699 	}
10700 	/*
10701 	 * now treat it like a rxt event, everything is outstanding
10702 	 * and sent nothing acvked and dupacks are all zero. If this
10703 	 * is not an attacker it will have to dupack its way through
10704 	 * it all.
10705 	 */
10706 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
10707 	TQHASH_FOREACH(rsm, rack->r_ctl.tqh)  {
10708 		rsm->r_dupack = 0;
10709 		/* We must re-add it back to the tlist */
10710 		if (trsm == NULL) {
10711 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
10712 		} else {
10713 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, trsm, rsm, r_tnext);
10714 		}
10715 		rsm->r_in_tmap = 1;
10716 		trsm = rsm;
10717 		rsm->r_flags &= ~(RACK_ACKED | RACK_SACK_PASSED | RACK_WAS_SACKPASS | RACK_RWND_COLLAPSED);
10718 	}
10719 	sack_filter_clear(&rack->r_ctl.rack_sf, rack->rc_tp->snd_una);
10720 }
10721 
10722 static void
10723 rack_do_detection(struct tcpcb *tp, struct tcp_rack *rack,  uint32_t bytes_this_ack, uint32_t segsiz)
10724 {
10725 	int do_detection = 0;
10726 
10727 	if (rack->sack_attack_disable || rack->rc_suspicious) {
10728 		/*
10729 		 * If we have been disabled we must detect
10730 		 * to possibly reverse it. Or if the guy has
10731 		 * sent in suspicious sacks we want to do detection too.
10732 		 */
10733 		do_detection = 1;
10734 
10735 	} else if  ((rack->do_detection || tcp_force_detection) &&
10736 		    (tcp_sack_to_ack_thresh > 0) &&
10737 		    (tcp_sack_to_move_thresh > 0) &&
10738 		    (rack->r_ctl.rc_num_maps_alloced > tcp_map_minimum)) {
10739 		/*
10740 		 * We only detect here if:
10741 		 * 1) System wide forcing is on <or> do_detection is on
10742 		 *   <and>
10743 		 * 2) We have thresholds for move and ack (set one to 0 and we are off)
10744 		 *   <and>
10745 		 * 3) We have maps allocated larger than our min (500).
10746 		 */
10747 		do_detection = 1;
10748 	}
10749 	if (do_detection > 0) {
10750 		/*
10751 		 * We have thresholds set to find
10752 		 * possible attackers and disable sack.
10753 		 * Check them.
10754 		 */
10755 		uint64_t ackratio, moveratio, movetotal;
10756 
10757 		/* Log detecting */
10758 		rack_log_sad(rack, 1);
10759 		/* Do we establish a ack ratio */
10760 		if ((rack->r_ctl.sack_count > tcp_map_minimum)  ||
10761 		    (rack->rc_suspicious == 1) ||
10762 		    (rack->sack_attack_disable > 0)) {
10763 			ackratio = (uint64_t)(rack->r_ctl.sack_count);
10764 			ackratio *= (uint64_t)(1000);
10765 			if (rack->r_ctl.ack_count)
10766 				ackratio /= (uint64_t)(rack->r_ctl.ack_count);
10767 			else {
10768 				/* We can hit this due to ack totals degregation (via small sacks) */
10769 				ackratio = 1000;
10770 			}
10771 		} else {
10772 			/*
10773 			 * No ack ratio needed if we have not
10774 			 * seen more sacks then the number of map entries.
10775 			 * The exception to that is if we have disabled sack then
10776 			 * we need to find a ratio.
10777 			 */
10778 			ackratio = 0;
10779 		}
10780 
10781 		if ((rack->sack_attack_disable == 0) &&
10782 		    (ackratio > rack_highest_sack_thresh_seen))
10783 			rack_highest_sack_thresh_seen = (uint32_t)ackratio;
10784 		/* Do we establish a move ratio? */
10785 		if ((rack->r_ctl.sack_moved_extra > tcp_map_minimum) ||
10786 		    (rack->rc_suspicious == 1) ||
10787 		    (rack->sack_attack_disable > 0)) {
10788 			/*
10789 			 * We need to have more sack moves than maps
10790 			 * allocated to have a move ratio considered.
10791 			 */
10792 			movetotal = rack->r_ctl.sack_moved_extra;
10793 			movetotal += rack->r_ctl.sack_noextra_move;
10794 			moveratio = rack->r_ctl.sack_moved_extra;
10795 			moveratio *= (uint64_t)1000;
10796 			if (movetotal)
10797 				moveratio /= movetotal;
10798 			else {
10799 				/* No moves, thats pretty good */
10800 				moveratio = 0;
10801 			}
10802 		} else {
10803 			/*
10804 			 * Not enough moves have occured to consider
10805 			 * if we are out of whack in that ratio.
10806 			 * The exception to that is if we have disabled sack then
10807 			 * we need to find a ratio.
10808 			 */
10809 			moveratio = 0;
10810 		}
10811 		if ((rack->sack_attack_disable == 0) &&
10812 		    (moveratio > rack_highest_move_thresh_seen))
10813 			rack_highest_move_thresh_seen = (uint32_t)moveratio;
10814 		/* Now the tests */
10815 		if (rack->sack_attack_disable == 0) {
10816 			/* Not disabled, do we need to disable? */
10817 			if ((ackratio > tcp_sack_to_ack_thresh) &&
10818 			    (moveratio > tcp_sack_to_move_thresh)) {
10819 				/* Disable sack processing */
10820 				tcp_trace_point(rack->rc_tp, TCP_TP_SAD_TRIGGERED);
10821 				rack->sack_attack_disable = 1;
10822 				/* set it so we have the built in delay */
10823 				rack->r_ctl.ack_during_sd = 1;
10824 				if (rack_merge_out_sacks_on_attack)
10825 					rack_merge_out_sacks(rack);
10826 				counter_u64_add(rack_sack_attacks_detected, 1);
10827 				tcp_trace_point(rack->rc_tp, TCP_TP_SAD_TRIGGERED);
10828 				/* Clamp the cwnd at flight size */
10829 				rack->r_ctl.rc_saved_cwnd = rack->rc_tp->snd_cwnd;
10830 				rack->rc_tp->snd_cwnd = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
10831 				rack_log_sad(rack, 2);
10832 			}
10833 		} else {
10834 			/* We are sack-disabled check for false positives */
10835 			if ((ackratio <= tcp_restoral_thresh) ||
10836 			    ((rack_merge_out_sacks_on_attack == 0) &&
10837 			     (rack->rc_suspicious == 0) &&
10838 			     (rack->r_ctl.rc_num_maps_alloced <= (tcp_map_minimum/2)))) {
10839 				rack->sack_attack_disable = 0;
10840 				rack_log_sad(rack, 3);
10841 				/* Restart counting */
10842 				rack->r_ctl.sack_count = 0;
10843 				rack->r_ctl.sack_moved_extra = 0;
10844 				rack->r_ctl.sack_noextra_move = 1;
10845 				rack->rc_suspicious = 0;
10846 				rack->r_ctl.ack_count = max(1,
10847 							    (bytes_this_ack / segsiz));
10848 
10849 				counter_u64_add(rack_sack_attacks_reversed, 1);
10850 				/* Restore the cwnd */
10851 				if (rack->r_ctl.rc_saved_cwnd > rack->rc_tp->snd_cwnd)
10852 					rack->rc_tp->snd_cwnd = rack->r_ctl.rc_saved_cwnd;
10853 			}
10854 		}
10855 	}
10856 }
10857 #endif
10858 
10859 static int
10860 rack_note_dsack(struct tcp_rack *rack, tcp_seq start, tcp_seq end)
10861 {
10862 
10863 	uint32_t am, l_end;
10864 	int was_tlp = 0;
10865 
10866 	if (SEQ_GT(end, start))
10867 		am = end - start;
10868 	else
10869 		am = 0;
10870 	if ((rack->rc_last_tlp_acked_set ) &&
10871 	    (SEQ_GEQ(start, rack->r_ctl.last_tlp_acked_start)) &&
10872 	    (SEQ_LEQ(end, rack->r_ctl.last_tlp_acked_end))) {
10873 		/*
10874 		 * The DSACK is because of a TLP which we don't
10875 		 * do anything with the reordering window over since
10876 		 * it was not reordering that caused the DSACK but
10877 		 * our previous retransmit TLP.
10878 		 */
10879 		rack_log_dsack_event(rack, 7, __LINE__, start, end);
10880 		was_tlp = 1;
10881 		goto skip_dsack_round;
10882 	}
10883 	if (rack->rc_last_sent_tlp_seq_valid) {
10884 		l_end = rack->r_ctl.last_sent_tlp_seq + rack->r_ctl.last_sent_tlp_len;
10885 		if (SEQ_GEQ(start, rack->r_ctl.last_sent_tlp_seq) &&
10886 		    (SEQ_LEQ(end, l_end))) {
10887 			/*
10888 			 * This dsack is from the last sent TLP, ignore it
10889 			 * for reordering purposes.
10890 			 */
10891 			rack_log_dsack_event(rack, 7, __LINE__, start, end);
10892 			was_tlp = 1;
10893 			goto skip_dsack_round;
10894 		}
10895 	}
10896 	if (rack->rc_dsack_round_seen == 0) {
10897 		rack->rc_dsack_round_seen = 1;
10898 		rack->r_ctl.dsack_round_end = rack->rc_tp->snd_max;
10899 		rack->r_ctl.num_dsack++;
10900 		rack->r_ctl.dsack_persist = 16;	/* 16 is from the standard */
10901 		rack_log_dsack_event(rack, 2, __LINE__, 0, 0);
10902 	}
10903 skip_dsack_round:
10904 	/*
10905 	 * We keep track of how many DSACK blocks we get
10906 	 * after a recovery incident.
10907 	 */
10908 	rack->r_ctl.dsack_byte_cnt += am;
10909 	if (!IN_FASTRECOVERY(rack->rc_tp->t_flags) &&
10910 	    rack->r_ctl.retran_during_recovery &&
10911 	    (rack->r_ctl.dsack_byte_cnt >= rack->r_ctl.retran_during_recovery)) {
10912 		/*
10913 		 * False recovery most likely culprit is reordering. If
10914 		 * nothing else is missing we need to revert.
10915 		 */
10916 		rack->r_might_revert = 1;
10917 		rack_handle_might_revert(rack->rc_tp, rack);
10918 		rack->r_might_revert = 0;
10919 		rack->r_ctl.retran_during_recovery = 0;
10920 		rack->r_ctl.dsack_byte_cnt = 0;
10921 	}
10922 	return (was_tlp);
10923 }
10924 
10925 static uint32_t
10926 do_rack_compute_pipe(struct tcpcb *tp, struct tcp_rack *rack, uint32_t snd_una)
10927 {
10928 	return (((tp->snd_max - snd_una) - rack->r_ctl.rc_sacked) + rack->r_ctl.rc_holes_rxt);
10929 }
10930 
10931 static int32_t
10932 rack_compute_pipe(struct tcpcb *tp)
10933 {
10934 	return ((int32_t)do_rack_compute_pipe(tp,
10935 					      (struct tcp_rack *)tp->t_fb_ptr,
10936 					      tp->snd_una));
10937 }
10938 
10939 static void
10940 rack_update_prr(struct tcpcb *tp, struct tcp_rack *rack, uint32_t changed, tcp_seq th_ack)
10941 {
10942 	/* Deal with changed and PRR here (in recovery only) */
10943 	uint32_t pipe, snd_una;
10944 
10945 	rack->r_ctl.rc_prr_delivered += changed;
10946 
10947 	if (sbavail(&rack->rc_inp->inp_socket->so_snd) <= (tp->snd_max - tp->snd_una)) {
10948 		/*
10949 		 * It is all outstanding, we are application limited
10950 		 * and thus we don't need more room to send anything.
10951 		 * Note we use tp->snd_una here and not th_ack because
10952 		 * the data as yet not been cut from the sb.
10953 		 */
10954 		rack->r_ctl.rc_prr_sndcnt = 0;
10955 		return;
10956 	}
10957 	/* Compute prr_sndcnt */
10958 	if (SEQ_GT(tp->snd_una, th_ack)) {
10959 		snd_una = tp->snd_una;
10960 	} else {
10961 		snd_una = th_ack;
10962 	}
10963 	pipe = do_rack_compute_pipe(tp, rack, snd_una);
10964 	if (pipe > tp->snd_ssthresh) {
10965 		long sndcnt;
10966 
10967 		sndcnt = rack->r_ctl.rc_prr_delivered * tp->snd_ssthresh;
10968 		if (rack->r_ctl.rc_prr_recovery_fs > 0)
10969 			sndcnt /= (long)rack->r_ctl.rc_prr_recovery_fs;
10970 		else {
10971 			rack->r_ctl.rc_prr_sndcnt = 0;
10972 			rack_log_to_prr(rack, 9, 0, __LINE__);
10973 			sndcnt = 0;
10974 		}
10975 		sndcnt++;
10976 		if (sndcnt > (long)rack->r_ctl.rc_prr_out)
10977 			sndcnt -= rack->r_ctl.rc_prr_out;
10978 		else
10979 			sndcnt = 0;
10980 		rack->r_ctl.rc_prr_sndcnt = sndcnt;
10981 		rack_log_to_prr(rack, 10, 0, __LINE__);
10982 	} else {
10983 		uint32_t limit;
10984 
10985 		if (rack->r_ctl.rc_prr_delivered > rack->r_ctl.rc_prr_out)
10986 			limit = (rack->r_ctl.rc_prr_delivered - rack->r_ctl.rc_prr_out);
10987 		else
10988 			limit = 0;
10989 		if (changed > limit)
10990 			limit = changed;
10991 		limit += ctf_fixed_maxseg(tp);
10992 		if (tp->snd_ssthresh > pipe) {
10993 			rack->r_ctl.rc_prr_sndcnt = min((tp->snd_ssthresh - pipe), limit);
10994 			rack_log_to_prr(rack, 11, 0, __LINE__);
10995 		} else {
10996 			rack->r_ctl.rc_prr_sndcnt = min(0, limit);
10997 			rack_log_to_prr(rack, 12, 0, __LINE__);
10998 		}
10999 	}
11000 }
11001 
11002 static void
11003 rack_log_ack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th, int entered_recovery, int dup_ack_struck,
11004 	     int *dsack_seen, int *sacks_seen)
11005 {
11006 	uint32_t changed;
11007 	struct tcp_rack *rack;
11008 	struct rack_sendmap *rsm;
11009 	struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1];
11010 	register uint32_t th_ack;
11011 	int32_t i, j, k, num_sack_blks = 0;
11012 	uint32_t cts, acked, ack_point;
11013 	int loop_start = 0, moved_two = 0, no_extra = 0;
11014 	uint32_t tsused;
11015 	uint32_t segsiz, o_cnt;
11016 
11017 
11018 	INP_WLOCK_ASSERT(tptoinpcb(tp));
11019 	if (tcp_get_flags(th) & TH_RST) {
11020 		/* We don't log resets */
11021 		return;
11022 	}
11023 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11024 	cts = tcp_get_usecs(NULL);
11025 	rsm = tqhash_min(rack->r_ctl.tqh);
11026 	changed = 0;
11027 	th_ack = th->th_ack;
11028 	if (rack->sack_attack_disable == 0)
11029 		rack_do_decay(rack);
11030 	segsiz = ctf_fixed_maxseg(rack->rc_tp);
11031 	if (BYTES_THIS_ACK(tp, th) >=  segsiz) {
11032 		/*
11033 		 * You only get credit for
11034 		 * MSS and greater (and you get extra
11035 		 * credit for larger cum-ack moves).
11036 		 */
11037 		int ac;
11038 
11039 		ac = BYTES_THIS_ACK(tp, th) / ctf_fixed_maxseg(rack->rc_tp);
11040 		rack->r_ctl.ack_count += ac;
11041 		counter_u64_add(rack_ack_total, ac);
11042 	}
11043 	if (rack->r_ctl.ack_count > 0xfff00000) {
11044 		/*
11045 		 * reduce the number to keep us under
11046 		 * a uint32_t.
11047 		 */
11048 		rack->r_ctl.ack_count /= 2;
11049 		rack->r_ctl.sack_count /= 2;
11050 	}
11051 	if (SEQ_GT(th_ack, tp->snd_una)) {
11052 		rack_log_progress_event(rack, tp, ticks, PROGRESS_UPDATE, __LINE__);
11053 		tp->t_acktime = ticks;
11054 	}
11055 	if (rsm && SEQ_GT(th_ack, rsm->r_start))
11056 		changed = th_ack - rsm->r_start;
11057 	if (changed) {
11058 		rack_process_to_cumack(tp, rack, th_ack, cts, to,
11059 				       tcp_tv_to_lusectick(&rack->r_ctl.act_rcv_time));
11060 	}
11061 	if ((to->to_flags & TOF_SACK) == 0) {
11062 		/* We are done nothing left and no sack. */
11063 		rack_handle_might_revert(tp, rack);
11064 		/*
11065 		 * For cases where we struck a dup-ack
11066 		 * with no SACK, add to the changes so
11067 		 * PRR will work right.
11068 		 */
11069 		if (dup_ack_struck && (changed == 0)) {
11070 			changed += ctf_fixed_maxseg(rack->rc_tp);
11071 		}
11072 		goto out;
11073 	}
11074 	/* Sack block processing */
11075 	if (SEQ_GT(th_ack, tp->snd_una))
11076 		ack_point = th_ack;
11077 	else
11078 		ack_point = tp->snd_una;
11079 	for (i = 0; i < to->to_nsacks; i++) {
11080 		bcopy((to->to_sacks + i * TCPOLEN_SACK),
11081 		      &sack, sizeof(sack));
11082 		sack.start = ntohl(sack.start);
11083 		sack.end = ntohl(sack.end);
11084 		if (SEQ_GT(sack.end, sack.start) &&
11085 		    SEQ_GT(sack.start, ack_point) &&
11086 		    SEQ_LT(sack.start, tp->snd_max) &&
11087 		    SEQ_GT(sack.end, ack_point) &&
11088 		    SEQ_LEQ(sack.end, tp->snd_max)) {
11089 			sack_blocks[num_sack_blks] = sack;
11090 			num_sack_blks++;
11091 		} else if (SEQ_LEQ(sack.start, th_ack) &&
11092 			   SEQ_LEQ(sack.end, th_ack)) {
11093 			int was_tlp;
11094 
11095 			if (dsack_seen != NULL)
11096 				*dsack_seen = 1;
11097 			was_tlp = rack_note_dsack(rack, sack.start, sack.end);
11098 			/*
11099 			 * Its a D-SACK block.
11100 			 */
11101 			tcp_record_dsack(tp, sack.start, sack.end, was_tlp);
11102 		}
11103 	}
11104 	if (rack->rc_dsack_round_seen) {
11105 		/* Is the dsack roound over? */
11106 		if (SEQ_GEQ(th_ack, rack->r_ctl.dsack_round_end)) {
11107 			/* Yes it is */
11108 			rack->rc_dsack_round_seen = 0;
11109 			rack_log_dsack_event(rack, 3, __LINE__, 0, 0);
11110 		}
11111 	}
11112 	/*
11113 	 * Sort the SACK blocks so we can update the rack scoreboard with
11114 	 * just one pass.
11115 	 */
11116 	o_cnt = num_sack_blks;
11117 	num_sack_blks = sack_filter_blks(&rack->r_ctl.rack_sf, sack_blocks,
11118 					 num_sack_blks, th->th_ack);
11119 	ctf_log_sack_filter(rack->rc_tp, num_sack_blks, sack_blocks);
11120 	if (sacks_seen != NULL)
11121 		*sacks_seen = num_sack_blks;
11122 	if (num_sack_blks == 0) {
11123 		/* Nothing to sack, but we need to update counts */
11124 		if ((o_cnt == 1) &&
11125 		    (*dsack_seen != 1))
11126 			rack->r_ctl.sack_count++;
11127 		else if (o_cnt > 1)
11128 			rack->r_ctl.sack_count++;
11129 		goto out_with_totals;
11130 	}
11131 	if (rack->sack_attack_disable) {
11132 		/*
11133 		 * An attacker disablement is in place, for
11134 		 * every sack block that is not at least a full MSS
11135 		 * count up sack_count.
11136 		 */
11137 		for (i = 0; i < num_sack_blks; i++) {
11138 			if ((sack_blocks[i].end - sack_blocks[i].start) < segsiz) {
11139 				rack->r_ctl.sack_count++;
11140 			}
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 		}
11150 		goto out;
11151 	}
11152 	/* Its a sack of some sort */
11153 	rack->r_ctl.sack_count += num_sack_blks;
11154 	if (rack->r_ctl.sack_count > 0xfff00000) {
11155 		/*
11156 		 * reduce the number to keep us under
11157 		 * a uint32_t.
11158 		 */
11159 		rack->r_ctl.ack_count /= 2;
11160 		rack->r_ctl.sack_count /= 2;
11161 	}
11162 	if (num_sack_blks < 2) {
11163 		/* Only one, we don't need to sort */
11164 		goto do_sack_work;
11165 	}
11166 	/* Sort the sacks */
11167 	for (i = 0; i < num_sack_blks; i++) {
11168 		for (j = i + 1; j < num_sack_blks; j++) {
11169 			if (SEQ_GT(sack_blocks[i].end, sack_blocks[j].end)) {
11170 				sack = sack_blocks[i];
11171 				sack_blocks[i] = sack_blocks[j];
11172 				sack_blocks[j] = sack;
11173 			}
11174 		}
11175 	}
11176 	/*
11177 	 * Now are any of the sack block ends the same (yes some
11178 	 * implementations send these)?
11179 	 */
11180 again:
11181 	if (num_sack_blks == 0)
11182 		goto out_with_totals;
11183 	if (num_sack_blks > 1) {
11184 		for (i = 0; i < num_sack_blks; i++) {
11185 			for (j = i + 1; j < num_sack_blks; j++) {
11186 				if (sack_blocks[i].end == sack_blocks[j].end) {
11187 					/*
11188 					 * Ok these two have the same end we
11189 					 * want the smallest end and then
11190 					 * throw away the larger and start
11191 					 * again.
11192 					 */
11193 					if (SEQ_LT(sack_blocks[j].start, sack_blocks[i].start)) {
11194 						/*
11195 						 * The second block covers
11196 						 * more area use that
11197 						 */
11198 						sack_blocks[i].start = sack_blocks[j].start;
11199 					}
11200 					/*
11201 					 * Now collapse out the dup-sack and
11202 					 * lower the count
11203 					 */
11204 					for (k = (j + 1); k < num_sack_blks; k++) {
11205 						sack_blocks[j].start = sack_blocks[k].start;
11206 						sack_blocks[j].end = sack_blocks[k].end;
11207 						j++;
11208 					}
11209 					num_sack_blks--;
11210 					goto again;
11211 				}
11212 			}
11213 		}
11214 	}
11215 do_sack_work:
11216 	/*
11217 	 * First lets look to see if
11218 	 * we have retransmitted and
11219 	 * can use the transmit next?
11220 	 */
11221 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
11222 	if (rsm &&
11223 	    SEQ_GT(sack_blocks[0].end, rsm->r_start) &&
11224 	    SEQ_LT(sack_blocks[0].start, rsm->r_end)) {
11225 		/*
11226 		 * We probably did the FR and the next
11227 		 * SACK in continues as we would expect.
11228 		 */
11229 		acked = rack_proc_sack_blk(tp, rack, &sack_blocks[0], to, &rsm, cts, &no_extra, &moved_two, segsiz);
11230 		if (acked) {
11231 			rack->r_wanted_output = 1;
11232 			changed += acked;
11233 		}
11234 		if (num_sack_blks == 1) {
11235 			/*
11236 			 * This is what we would expect from
11237 			 * a normal implementation to happen
11238 			 * after we have retransmitted the FR,
11239 			 * i.e the sack-filter pushes down
11240 			 * to 1 block and the next to be retransmitted
11241 			 * is the sequence in the sack block (has more
11242 			 * are acked). Count this as ACK'd data to boost
11243 			 * up the chances of recovering any false positives.
11244 			 */
11245 			rack->r_ctl.ack_count += (acked / ctf_fixed_maxseg(rack->rc_tp));
11246 			counter_u64_add(rack_ack_total, (acked / ctf_fixed_maxseg(rack->rc_tp)));
11247 			counter_u64_add(rack_express_sack, 1);
11248 			if (rack->r_ctl.ack_count > 0xfff00000) {
11249 				/*
11250 				 * reduce the number to keep us under
11251 				 * a uint32_t.
11252 				 */
11253 				rack->r_ctl.ack_count /= 2;
11254 				rack->r_ctl.sack_count /= 2;
11255 			}
11256 			if (moved_two) {
11257 				/*
11258 				 * If we did not get a SACK for at least a MSS and
11259 				 * had to move at all, or if we moved more than our
11260 				 * threshold, it counts against the "extra" move.
11261 				 */
11262 				rack->r_ctl.sack_moved_extra += moved_two;
11263 				rack->r_ctl.sack_noextra_move += no_extra;
11264 				counter_u64_add(rack_move_some, 1);
11265 			} else {
11266 				/*
11267 				 * else we did not have to move
11268 				 * any more than we would expect.
11269 				 */
11270 				rack->r_ctl.sack_noextra_move += no_extra;
11271 				rack->r_ctl.sack_noextra_move++;
11272 				counter_u64_add(rack_move_none, 1);
11273 			}
11274 			if ((rack->r_ctl.sack_moved_extra > 0xfff00000) ||
11275 			    (rack->r_ctl.sack_noextra_move > 0xfff00000)) {
11276 				rack->r_ctl.sack_moved_extra /= 2;
11277 				rack->r_ctl.sack_noextra_move /= 2;
11278 			}
11279 			goto out_with_totals;
11280 		} else {
11281 			/*
11282 			 * Start the loop through the
11283 			 * rest of blocks, past the first block.
11284 			 */
11285 			loop_start = 1;
11286 		}
11287 	}
11288 	counter_u64_add(rack_sack_total, 1);
11289 	rsm = rack->r_ctl.rc_sacklast;
11290 	for (i = loop_start; i < num_sack_blks; i++) {
11291 		acked = rack_proc_sack_blk(tp, rack, &sack_blocks[i], to, &rsm, cts, &no_extra, &moved_two, segsiz);
11292 		if (acked) {
11293 			rack->r_wanted_output = 1;
11294 			changed += acked;
11295 		}
11296 		if (moved_two) {
11297 			/*
11298 			 * If we did not get a SACK for at least a MSS and
11299 			 * had to move at all, or if we moved more than our
11300 			 * threshold, it counts against the "extra" move.
11301 			 */
11302 			rack->r_ctl.sack_moved_extra += moved_two;
11303 			rack->r_ctl.sack_noextra_move += no_extra;
11304 			counter_u64_add(rack_move_some, 1);
11305 		} else {
11306 			/*
11307 			 * else we did not have to move
11308 			 * any more than we would expect.
11309 			 */
11310 			rack->r_ctl.sack_noextra_move += no_extra;
11311 			rack->r_ctl.sack_noextra_move++;
11312 			counter_u64_add(rack_move_none, 1);
11313 		}
11314 		if ((rack->r_ctl.sack_moved_extra > 0xfff00000) ||
11315 		    (rack->r_ctl.sack_noextra_move > 0xfff00000)) {
11316 			rack->r_ctl.sack_moved_extra /= 2;
11317 			rack->r_ctl.sack_noextra_move /= 2;
11318 		}
11319 		if (moved_two && (acked < ctf_fixed_maxseg(rack->rc_tp))) {
11320 			/*
11321 			 * If the SACK was not a full MSS then
11322 			 * we add to sack_count the number of
11323 			 * MSS's (or possibly more than
11324 			 * a MSS if its a TSO send) we had to skip by.
11325 			 */
11326 			rack->r_ctl.sack_count += moved_two;
11327 			if (rack->r_ctl.sack_count > 0xfff00000) {
11328 				rack->r_ctl.ack_count /= 2;
11329 				rack->r_ctl.sack_count /= 2;
11330 			}
11331 			counter_u64_add(rack_sack_total, moved_two);
11332 		}
11333 		/*
11334 		 * Now we need to setup for the next
11335 		 * round. First we make sure we won't
11336 		 * exceed the size of our uint32_t on
11337 		 * the various counts, and then clear out
11338 		 * moved_two.
11339 		 */
11340 		moved_two = 0;
11341 		no_extra = 0;
11342 	}
11343 out_with_totals:
11344 	if (num_sack_blks > 1) {
11345 		/*
11346 		 * You get an extra stroke if
11347 		 * you have more than one sack-blk, this
11348 		 * could be where we are skipping forward
11349 		 * and the sack-filter is still working, or
11350 		 * it could be an attacker constantly
11351 		 * moving us.
11352 		 */
11353 		rack->r_ctl.sack_moved_extra++;
11354 		counter_u64_add(rack_move_some, 1);
11355 	}
11356 out:
11357 #ifdef TCP_SAD_DETECTION
11358 	rack_do_detection(tp, rack, BYTES_THIS_ACK(tp, th), ctf_fixed_maxseg(rack->rc_tp));
11359 #endif
11360 	if (changed) {
11361 		/* Something changed cancel the rack timer */
11362 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
11363 	}
11364 	tsused = tcp_get_usecs(NULL);
11365 	rsm = tcp_rack_output(tp, rack, tsused);
11366 	if ((!IN_FASTRECOVERY(tp->t_flags)) &&
11367 	    rsm &&
11368 	    ((rsm->r_flags & RACK_MUST_RXT) == 0)) {
11369 		/* Enter recovery */
11370 		entered_recovery = 1;
11371 		rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
11372 		/*
11373 		 * When we enter recovery we need to assure we send
11374 		 * one packet.
11375 		 */
11376 		if (rack->rack_no_prr == 0) {
11377 			rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
11378 			rack_log_to_prr(rack, 8, 0, __LINE__);
11379 		}
11380 		rack->r_timer_override = 1;
11381 		rack->r_early = 0;
11382 		rack->r_ctl.rc_agg_early = 0;
11383 	} else if (IN_FASTRECOVERY(tp->t_flags) &&
11384 		   rsm &&
11385 		   (rack->r_rr_config == 3)) {
11386 		/*
11387 		 * Assure we can output and we get no
11388 		 * remembered pace time except the retransmit.
11389 		 */
11390 		rack->r_timer_override = 1;
11391 		rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
11392 		rack->r_ctl.rc_resend = rsm;
11393 	}
11394 	if (IN_FASTRECOVERY(tp->t_flags) &&
11395 	    (rack->rack_no_prr == 0) &&
11396 	    (entered_recovery == 0)) {
11397 		rack_update_prr(tp, rack, changed, th_ack);
11398 		if ((rsm && (rack->r_ctl.rc_prr_sndcnt >= ctf_fixed_maxseg(tp)) &&
11399 		     ((tcp_in_hpts(rack->rc_tp) == 0) &&
11400 		      ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)))) {
11401 			/*
11402 			 * If you are pacing output you don't want
11403 			 * to override.
11404 			 */
11405 			rack->r_early = 0;
11406 			rack->r_ctl.rc_agg_early = 0;
11407 			rack->r_timer_override = 1;
11408 		}
11409 	}
11410 }
11411 
11412 static void
11413 rack_strike_dupack(struct tcp_rack *rack)
11414 {
11415 	struct rack_sendmap *rsm;
11416 
11417 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
11418 	while (rsm) {
11419 		/*
11420 		 * We need to skip anything already set
11421 		 * to be retransmitted.
11422 		 */
11423 		if ((rsm->r_dupack >= DUP_ACK_THRESHOLD)  ||
11424 		    (rsm->r_flags & RACK_MUST_RXT)) {
11425 			rsm = TAILQ_NEXT(rsm, r_tnext);
11426 			continue;
11427 		}
11428 		break;
11429 	}
11430 	if (rsm && (rsm->r_dupack < 0xff)) {
11431 		rsm->r_dupack++;
11432 		if (rsm->r_dupack >= DUP_ACK_THRESHOLD) {
11433 			struct timeval tv;
11434 			uint32_t cts;
11435 			/*
11436 			 * Here we see if we need to retransmit. For
11437 			 * a SACK type connection if enough time has passed
11438 			 * we will get a return of the rsm. For a non-sack
11439 			 * connection we will get the rsm returned if the
11440 			 * dupack value is 3 or more.
11441 			 */
11442 			cts = tcp_get_usecs(&tv);
11443 			rack->r_ctl.rc_resend = tcp_rack_output(rack->rc_tp, rack, cts);
11444 			if (rack->r_ctl.rc_resend != NULL) {
11445 				if (!IN_FASTRECOVERY(rack->rc_tp->t_flags)) {
11446 					rack_cong_signal(rack->rc_tp, CC_NDUPACK,
11447 							 rack->rc_tp->snd_una, __LINE__);
11448 				}
11449 				rack->r_wanted_output = 1;
11450 				rack->r_timer_override = 1;
11451 				rack_log_retran_reason(rack, rsm, __LINE__, 1, 3);
11452 			}
11453 		} else {
11454 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 3);
11455 		}
11456 	}
11457 }
11458 
11459 static void
11460 rack_check_bottom_drag(struct tcpcb *tp,
11461 		       struct tcp_rack *rack,
11462 		       struct socket *so)
11463 {
11464 	uint32_t segsiz, minseg;
11465 
11466 	segsiz = ctf_fixed_maxseg(tp);
11467 	minseg = segsiz;
11468 	if (tp->snd_max == tp->snd_una) {
11469 		/*
11470 		 * We are doing dynamic pacing and we are way
11471 		 * under. Basically everything got acked while
11472 		 * we were still waiting on the pacer to expire.
11473 		 *
11474 		 * This means we need to boost the b/w in
11475 		 * addition to any earlier boosting of
11476 		 * the multiplier.
11477 		 */
11478 		uint64_t lt_bw;
11479 
11480 		lt_bw = rack_get_lt_bw(rack);
11481 		rack->rc_dragged_bottom = 1;
11482 		rack_validate_multipliers_at_or_above100(rack);
11483 		if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_VALID) &&
11484 		    (lt_bw > 0)) {
11485 			/*
11486 			 * Lets use the long-term b/w we have
11487 			 * been getting as a base.
11488 			 */
11489 			if (rack->rc_gp_filled == 0) {
11490 				if (lt_bw > ONE_POINT_TWO_MEG) {
11491 					/*
11492 					 * If we have no measurement
11493 					 * don't let us set in more than
11494 					 * 1.2Mbps. If we are still too
11495 					 * low after pacing with this we
11496 					 * will hopefully have a max b/w
11497 					 * available to sanity check things.
11498 					 */
11499 					lt_bw = ONE_POINT_TWO_MEG;
11500 				}
11501 				rack->r_ctl.rc_rtt_diff = 0;
11502 				rack->r_ctl.gp_bw = lt_bw;
11503 				rack->rc_gp_filled = 1;
11504 				if (rack->r_ctl.num_measurements < RACK_REQ_AVG)
11505 					rack->r_ctl.num_measurements = RACK_REQ_AVG;
11506 				rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
11507 			} else if (lt_bw > rack->r_ctl.gp_bw) {
11508 				rack->r_ctl.rc_rtt_diff = 0;
11509 				if (rack->r_ctl.num_measurements < RACK_REQ_AVG)
11510 					rack->r_ctl.num_measurements = RACK_REQ_AVG;
11511 				rack->r_ctl.gp_bw = lt_bw;
11512 				rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
11513 			} else
11514 				rack_increase_bw_mul(rack, -1, 0, 0, 1);
11515 			if ((rack->gp_ready == 0) &&
11516 			    (rack->r_ctl.num_measurements >= rack->r_ctl.req_measurements)) {
11517 				/* We have enough measurements now */
11518 				rack->gp_ready = 1;
11519 				if ((rack->rc_always_pace && (rack->use_fixed_rate == 0)) ||
11520 				    rack->rack_hibeta)
11521 					rack_set_cc_pacing(rack);
11522 				if (rack->defer_options)
11523 					rack_apply_deferred_options(rack);
11524 			}
11525 		} else {
11526 			/*
11527 			 * zero rtt possibly?, settle for just an old increase.
11528 			 */
11529 			rack_increase_bw_mul(rack, -1, 0, 0, 1);
11530 		}
11531 	} else if ((IN_FASTRECOVERY(tp->t_flags) == 0) &&
11532 		   (sbavail(&so->so_snd) > max((segsiz * (4 + rack_req_segs)),
11533 					       minseg)) &&
11534 		   (rack->r_ctl.cwnd_to_use > max((segsiz * (rack_req_segs + 2)), minseg)) &&
11535 		   (tp->snd_wnd > max((segsiz * (rack_req_segs + 2)), minseg)) &&
11536 		   (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) <=
11537 		    (segsiz * rack_req_segs))) {
11538 		/*
11539 		 * We are doing dynamic GP pacing and
11540 		 * we have everything except 1MSS or less
11541 		 * bytes left out. We are still pacing away.
11542 		 * And there is data that could be sent, This
11543 		 * means we are inserting delayed ack time in
11544 		 * our measurements because we are pacing too slow.
11545 		 */
11546 		rack_validate_multipliers_at_or_above100(rack);
11547 		rack->rc_dragged_bottom = 1;
11548 		rack_increase_bw_mul(rack, -1, 0, 0, 1);
11549 	}
11550 }
11551 
11552 #ifdef TCP_REQUEST_TRK
11553 static void
11554 rack_log_hybrid(struct tcp_rack *rack, uint32_t seq,
11555 		struct http_sendfile_track *cur, uint8_t mod, int line, int err)
11556 {
11557 	int do_log;
11558 
11559 	do_log = tcp_bblogging_on(rack->rc_tp);
11560 	if (do_log == 0) {
11561 		if ((do_log = tcp_bblogging_point_on(rack->rc_tp, TCP_BBPOINT_REQ_LEVEL_LOGGING) )== 0)
11562 			return;
11563 		/* We only allow the three below with point logging on */
11564 		if ((mod != HYBRID_LOG_RULES_APP) &&
11565 		    (mod != HYBRID_LOG_RULES_SET) &&
11566 		    (mod != HYBRID_LOG_REQ_COMP))
11567 			return;
11568 
11569 	}
11570 	if (do_log) {
11571 		union tcp_log_stackspecific log;
11572 		struct timeval tv;
11573 
11574 		/* Convert our ms to a microsecond */
11575 		memset(&log, 0, sizeof(log));
11576 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
11577 		log.u_bbr.flex1 = seq;
11578 		log.u_bbr.cwnd_gain = line;
11579 		if (cur != NULL) {
11580 			uint64_t off;
11581 
11582 			log.u_bbr.flex2 = cur->start_seq;
11583 			log.u_bbr.flex3 = cur->end_seq;
11584 			log.u_bbr.flex4 = (uint32_t)((cur->localtime >> 32) & 0x00000000ffffffff);
11585 			log.u_bbr.flex5 = (uint32_t)(cur->localtime & 0x00000000ffffffff);
11586 			log.u_bbr.flex6 = cur->flags;
11587 			log.u_bbr.pkts_out = cur->hybrid_flags;
11588 			log.u_bbr.rttProp = cur->timestamp;
11589 			log.u_bbr.cur_del_rate = cur->cspr;
11590 			log.u_bbr.bw_inuse = cur->start;
11591 			log.u_bbr.applimited = (uint32_t)(cur->end & 0x00000000ffffffff);
11592 			log.u_bbr.delivered = (uint32_t)((cur->end >> 32) & 0x00000000ffffffff) ;
11593 			log.u_bbr.epoch = (uint32_t)(cur->deadline & 0x00000000ffffffff);
11594 			log.u_bbr.lt_epoch = (uint32_t)((cur->deadline >> 32) & 0x00000000ffffffff) ;
11595 			log.u_bbr.bbr_state = 1;
11596 			off = (uint64_t)(cur) - (uint64_t)(&rack->rc_tp->t_http_info[0]);
11597 			log.u_bbr.use_lt_bw = (uint8_t)(off / sizeof(struct http_sendfile_track));
11598 		} else {
11599 			log.u_bbr.flex2 = err;
11600 		}
11601 		/*
11602 		 * Fill in flex7 to be CHD (catchup|hybrid|DGP)
11603 		 */
11604 		log.u_bbr.flex7 = rack->rc_catch_up;
11605 		log.u_bbr.flex7 <<= 1;
11606 		log.u_bbr.flex7 |= rack->rc_hybrid_mode;
11607 		log.u_bbr.flex7 <<= 1;
11608 		log.u_bbr.flex7 |= rack->dgp_on;
11609 		log.u_bbr.flex8 = mod;
11610 		log.u_bbr.delRate = rack->r_ctl.bw_rate_cap;
11611 		log.u_bbr.bbr_substate = rack->r_ctl.client_suggested_maxseg;
11612 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
11613 		log.u_bbr.pkt_epoch = rack->rc_tp->tcp_hybrid_start;
11614 		log.u_bbr.lost = rack->rc_tp->tcp_hybrid_error;
11615 		log.u_bbr.pacing_gain = (uint16_t)rack->rc_tp->tcp_hybrid_stop;
11616 		tcp_log_event(rack->rc_tp, NULL,
11617 		    &rack->rc_inp->inp_socket->so_rcv,
11618 		    &rack->rc_inp->inp_socket->so_snd,
11619 		    TCP_HYBRID_PACING_LOG, 0,
11620 	            0, &log, false, NULL, __func__, __LINE__, &tv);
11621 	}
11622 }
11623 #endif
11624 
11625 #ifdef TCP_REQUEST_TRK
11626 static void
11627 rack_set_dgp_hybrid_mode(struct tcp_rack *rack, tcp_seq seq, uint32_t len)
11628 {
11629 	struct http_sendfile_track *rc_cur;
11630 	struct tcpcb *tp;
11631 	int err = 0;
11632 
11633 	rc_cur = tcp_http_find_req_for_seq(rack->rc_tp, seq);
11634 	if (rc_cur == NULL) {
11635 		/* If not in the beginning what about the end piece */
11636 		rack_log_hybrid(rack, seq, NULL, HYBRID_LOG_NO_RANGE, __LINE__, err);
11637 		rc_cur = tcp_http_find_req_for_seq(rack->rc_tp, (seq + len - 1));
11638 	} else {
11639 		err = 12345;
11640 	}
11641 	/* If we find no parameters we are in straight DGP mode */
11642 	if(rc_cur == NULL) {
11643 		/* None found for this seq, just DGP for now */
11644 		rack->r_ctl.client_suggested_maxseg = 0;
11645 		rack->rc_catch_up = 0;
11646 		rack->r_ctl.bw_rate_cap = 0;
11647 		rack_log_hybrid(rack, (seq + len - 1), NULL, HYBRID_LOG_NO_RANGE, __LINE__, err);
11648 		if (rack->r_ctl.rc_last_sft) {
11649 			rack->r_ctl.rc_last_sft = NULL;
11650 		}
11651 		return;
11652 	}
11653 	/*
11654 	 * Ok if we have a new entry *or* have never
11655 	 * set up an entry we need to proceed. If
11656 	 * we have already set it up this entry we
11657 	 * just continue along with what we already
11658 	 * setup.
11659 	 */
11660 	tp = rack->rc_tp;
11661 	if ((rack->r_ctl.rc_last_sft != NULL) &&
11662 	    (rack->r_ctl.rc_last_sft == rc_cur)) {
11663 		/* Its already in place */
11664 		rack_log_hybrid(rack, seq, rc_cur, HYBRID_LOG_ISSAME, __LINE__, 0);
11665 		return;
11666 	}
11667 	if (rack->rc_hybrid_mode == 0) {
11668 		rack->r_ctl.rc_last_sft = rc_cur;
11669 		rack_log_hybrid(rack, seq, rc_cur, HYBRID_LOG_RULES_APP, __LINE__, 0);
11670 		return;
11671 	}
11672 	if ((rc_cur->hybrid_flags & TCP_HYBRID_PACING_CSPR) && rc_cur->cspr){
11673 		/* Compensate for all the header overhead's */
11674 		rack->r_ctl.bw_rate_cap	= rack_compensate_for_linerate(rack, rc_cur->cspr);
11675 	} else
11676 		rack->r_ctl.bw_rate_cap = 0;
11677 	if (rc_cur->hybrid_flags & TCP_HYBRID_PACING_H_MS)
11678 		rack->r_ctl.client_suggested_maxseg = rc_cur->hint_maxseg;
11679 	else
11680 		rack->r_ctl.client_suggested_maxseg = 0;
11681 	if ((rc_cur->hybrid_flags & TCP_HYBRID_PACING_CU) &&
11682 	    (rc_cur->cspr > 0)) {
11683 		uint64_t len;
11684 
11685 		rack->rc_catch_up = 1;
11686 		/*
11687 		 * Calculate the deadline time, first set the
11688 		 * time to when the request arrived.
11689 		 */
11690 		rc_cur->deadline = rc_cur->localtime;
11691 		/*
11692 		 * Next calculate the length and compensate for
11693 		 * TLS if need be.
11694 		 */
11695 		len = rc_cur->end - rc_cur->start;
11696 		if (tp->t_inpcb.inp_socket->so_snd.sb_tls_info) {
11697 			/*
11698 			 * This session is doing TLS. Take a swag guess
11699 			 * at the overhead.
11700 			 */
11701 			len += tcp_estimate_tls_overhead(tp->t_inpcb.inp_socket, len);
11702 		}
11703 		/*
11704 		 * Now considering the size, and the cspr, what is the time that
11705 		 * would be required at the cspr rate. Here we use the raw
11706 		 * cspr value since the client only looks at the raw data. We
11707 		 * do use len which includes TLS overhead, but not the TCP/IP etc.
11708 		 * That will get made up for in the CU pacing rate set.
11709 		 */
11710 		len *= HPTS_USEC_IN_SEC;
11711 		len /= rc_cur->cspr;
11712 		rc_cur->deadline += len;
11713 	} else {
11714 		rack->rc_catch_up = 0;
11715 		rc_cur->deadline = 0;
11716 	}
11717 	if (rack->r_ctl.client_suggested_maxseg != 0) {
11718 		/*
11719 		 * We need to reset the max pace segs if we have a
11720 		 * client_suggested_maxseg.
11721 		 */
11722 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
11723 	}
11724 	rack_log_hybrid(rack, seq, rc_cur, HYBRID_LOG_RULES_APP, __LINE__, 0);
11725 	/* Remember it for next time and for CU mode */
11726 	rack->r_ctl.rc_last_sft = rc_cur;
11727 }
11728 #endif
11729 
11730 static void
11731 rack_chk_http_and_hybrid_on_out(struct tcp_rack *rack, tcp_seq seq, uint32_t len, uint64_t cts)
11732 {
11733 #ifdef TCP_REQUEST_TRK
11734 	struct http_sendfile_track *ent;
11735 
11736 	ent = rack->r_ctl.rc_last_sft;
11737 	if ((ent == NULL) ||
11738 	    (ent->flags == TCP_HTTP_TRACK_FLG_EMPTY) ||
11739 	    (SEQ_GEQ(seq, ent->end_seq))) {
11740 		/* Time to update the track. */
11741 		rack_set_dgp_hybrid_mode(rack, seq, len);
11742 		ent = rack->r_ctl.rc_last_sft;
11743 	}
11744 	/* Out of all */
11745 	if (ent == NULL) {
11746 		return;
11747 	}
11748 	if (SEQ_LT(ent->end_seq, (seq + len))) {
11749 		/*
11750 		 * This is the case where our end_seq guess
11751 		 * was wrong. This is usually due to TLS having
11752 		 * more bytes then our guess. It could also be the
11753 		 * case that the client sent in two requests closely
11754 		 * and the SB is full of both so we are sending part
11755 		 * of each (end|beg). In such a case lets move this
11756 		 * guys end to match the end of this send. That
11757 		 * way it will complete when all of it is acked.
11758 		 */
11759 		ent->end_seq = (seq + len);
11760 		rack_log_hybrid_bw(rack, seq, len, 0, 0, HYBRID_LOG_EXTEND, 0, ent);
11761 	}
11762 	/* Now validate we have set the send time of this one */
11763 	if ((ent->flags & TCP_HTTP_TRACK_FLG_FSND) == 0) {
11764 		ent->flags |= TCP_HTTP_TRACK_FLG_FSND;
11765 		ent->first_send = cts;
11766 		ent->sent_at_fs = rack->rc_tp->t_sndbytes;
11767 		ent->rxt_at_fs = rack->rc_tp->t_snd_rxt_bytes;
11768 	}
11769 #endif
11770 }
11771 
11772 static void
11773 rack_gain_for_fastoutput(struct tcp_rack *rack, struct tcpcb *tp, struct socket *so, uint32_t acked_amount)
11774 {
11775 	/*
11776 	 * The fast output path is enabled and we
11777 	 * have moved the cumack forward. Lets see if
11778 	 * we can expand forward the fast path length by
11779 	 * that amount. What we would ideally like to
11780 	 * do is increase the number of bytes in the
11781 	 * fast path block (left_to_send) by the
11782 	 * acked amount. However we have to gate that
11783 	 * by two factors:
11784 	 * 1) The amount outstanding and the rwnd of the peer
11785 	 *    (i.e. we don't want to exceed the rwnd of the peer).
11786 	 *    <and>
11787 	 * 2) The amount of data left in the socket buffer (i.e.
11788 	 *    we can't send beyond what is in the buffer).
11789 	 *
11790 	 * Note that this does not take into account any increase
11791 	 * in the cwnd. We will only extend the fast path by
11792 	 * what was acked.
11793 	 */
11794 	uint32_t new_total, gating_val;
11795 
11796 	new_total = acked_amount + rack->r_ctl.fsb.left_to_send;
11797 	gating_val = min((sbavail(&so->so_snd) - (tp->snd_max - tp->snd_una)),
11798 			 (tp->snd_wnd - (tp->snd_max - tp->snd_una)));
11799 	if (new_total <= gating_val) {
11800 		/* We can increase left_to_send by the acked amount */
11801 		counter_u64_add(rack_extended_rfo, 1);
11802 		rack->r_ctl.fsb.left_to_send = new_total;
11803 		KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(&rack->rc_inp->inp_socket->so_snd) - (tp->snd_max - tp->snd_una))),
11804 			("rack:%p left_to_send:%u sbavail:%u out:%u",
11805 			 rack, rack->r_ctl.fsb.left_to_send,
11806 			 sbavail(&rack->rc_inp->inp_socket->so_snd),
11807 			 (tp->snd_max - tp->snd_una)));
11808 
11809 	}
11810 }
11811 
11812 static void
11813 rack_adjust_sendmap_head(struct tcp_rack *rack, struct sockbuf *sb)
11814 {
11815 	/*
11816 	 * Here any sendmap entry that points to the
11817 	 * beginning mbuf must be adjusted to the correct
11818 	 * offset. This must be called with:
11819 	 * 1) The socket buffer locked
11820 	 * 2) snd_una adjusted to its new position.
11821 	 *
11822 	 * Note that (2) implies rack_ack_received has also
11823 	 * been called and all the sbcut's have been done.
11824 	 *
11825 	 * We grab the first mbuf in the socket buffer and
11826 	 * then go through the front of the sendmap, recalculating
11827 	 * the stored offset for any sendmap entry that has
11828 	 * that mbuf. We must use the sb functions to do this
11829 	 * since its possible an add was done has well as
11830 	 * the subtraction we may have just completed. This should
11831 	 * not be a penalty though, since we just referenced the sb
11832 	 * to go in and trim off the mbufs that we freed (of course
11833 	 * there will be a penalty for the sendmap references though).
11834 	 *
11835 	 * Note also with INVARIANT on, we validate with a KASSERT
11836 	 * that the first sendmap entry has a soff of 0.
11837 	 *
11838 	 */
11839 	struct mbuf *m;
11840 	struct rack_sendmap *rsm;
11841 	tcp_seq snd_una;
11842 #ifdef INVARIANTS
11843 	int first_processed = 0;
11844 #endif
11845 
11846 	snd_una = rack->rc_tp->snd_una;
11847 	SOCKBUF_LOCK_ASSERT(sb);
11848 	m = sb->sb_mb;
11849 	rsm = tqhash_min(rack->r_ctl.tqh);
11850 	if ((rsm == NULL) || (m == NULL)) {
11851 		/* Nothing outstanding */
11852 		return;
11853 	}
11854 	/* The very first RSM's mbuf must point to the head mbuf in the sb */
11855 	KASSERT((rsm->m == m),
11856 		("Rack:%p sb:%p rsm:%p -- first rsm mbuf not aligned to sb",
11857 		 rack, sb, rsm));
11858 	while (rsm->m && (rsm->m == m)) {
11859 		/* one to adjust */
11860 #ifdef INVARIANTS
11861 		struct mbuf *tm;
11862 		uint32_t soff;
11863 
11864 		tm = sbsndmbuf(sb, (rsm->r_start - snd_una), &soff);
11865 		if ((rsm->orig_m_len != m->m_len) ||
11866 		    (rsm->orig_t_space != M_TRAILINGROOM(m))){
11867 			rack_adjust_orig_mlen(rsm);
11868 		}
11869 		if (first_processed == 0) {
11870 			KASSERT((rsm->soff == 0),
11871 				("Rack:%p rsm:%p -- rsm at head but soff not zero",
11872 				 rack, rsm));
11873 			first_processed = 1;
11874 		}
11875 		if ((rsm->soff != soff) || (rsm->m != tm)) {
11876 			/*
11877 			 * This is not a fatal error, we anticipate it
11878 			 * might happen (the else code), so we count it here
11879 			 * so that under invariant we can see that it really
11880 			 * does happen.
11881 			 */
11882 			counter_u64_add(rack_adjust_map_bw, 1);
11883 		}
11884 		rsm->m = tm;
11885 		rsm->soff = soff;
11886 		if (tm) {
11887 			rsm->orig_m_len = rsm->m->m_len;
11888 			rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
11889 		} else {
11890 			rsm->orig_m_len = 0;
11891 			rsm->orig_t_space = 0;
11892 		}
11893 #else
11894 		rsm->m = sbsndmbuf(sb, (rsm->r_start - snd_una), &rsm->soff);
11895 		if (rsm->m) {
11896 			rsm->orig_m_len = rsm->m->m_len;
11897 			rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
11898 		} else {
11899 			rsm->orig_m_len = 0;
11900 			rsm->orig_t_space = 0;
11901 		}
11902 #endif
11903 		rsm = tqhash_next(rack->r_ctl.tqh, rsm);
11904 		if (rsm == NULL)
11905 			break;
11906 	}
11907 }
11908 
11909 #ifdef TCP_REQUEST_TRK
11910 static inline void
11911 rack_http_check_for_comp(struct tcp_rack *rack, tcp_seq th_ack)
11912 {
11913 	struct http_sendfile_track *ent;
11914 	int i;
11915 
11916 	if ((rack->rc_hybrid_mode == 0) &&
11917 	    (tcp_bblogging_point_on(rack->rc_tp, TCP_BBPOINT_REQ_LEVEL_LOGGING) == 0)) {
11918 		/*
11919 		 * Just do normal completions hybrid pacing is not on
11920 		 * and CLDL is off as well.
11921 		 */
11922 		tcp_http_check_for_comp(rack->rc_tp, th_ack);
11923 		return;
11924 	}
11925 	/*
11926 	 * Originally I was just going to find the th_ack associated
11927 	 * with an entry. But then I realized a large strech ack could
11928 	 * in theory ack two or more requests at once. So instead we
11929 	 * need to find all entries that are completed by th_ack not
11930 	 * just a single entry and do our logging.
11931 	 */
11932 	ent = tcp_http_find_a_req_that_is_completed_by(rack->rc_tp, th_ack, &i);
11933 	while (ent != NULL) {
11934 		/*
11935 		 * We may be doing hybrid pacing or CLDL and need more details possibly
11936 		 * so we do it manually instead of calling
11937 		 * tcp_http_check_for_comp()
11938 		 */
11939 		uint64_t laa, tim, data, cbw, ftim;
11940 
11941 		/* Ok this ack frees it */
11942 		rack_log_hybrid(rack, th_ack,
11943 				ent, HYBRID_LOG_REQ_COMP, __LINE__, 0);
11944 		/* calculate the time based on the ack arrival */
11945 		data = ent->end - ent->start;
11946 		laa = tcp_tv_to_lusectick(&rack->r_ctl.act_rcv_time);
11947 		if (ent->flags & TCP_HTTP_TRACK_FLG_FSND) {
11948 			if (ent->first_send > ent->localtime)
11949 				ftim = ent->first_send;
11950 			else
11951 				ftim = ent->localtime;
11952 		} else {
11953 			/* TSNH */
11954 			ftim = ent->localtime;
11955 		}
11956 		if (laa > ent->localtime)
11957 			tim = laa - ftim;
11958 		else
11959 			tim = 0;
11960 		cbw = data * HPTS_USEC_IN_SEC;
11961 		if (tim > 0)
11962 			cbw /= tim;
11963 		else
11964 			cbw = 0;
11965 		rack_log_hybrid_bw(rack, th_ack, cbw, tim, data, HYBRID_LOG_BW_MEASURE, 0, ent);
11966 		/*
11967 		 * Check to see if we are freeing what we are pointing to send wise
11968 		 * if so be sure to NULL the pointer so we know we are no longer
11969 		 * set to anything.
11970 		 */
11971 		if (ent == rack->r_ctl.rc_last_sft)
11972 			rack->r_ctl.rc_last_sft = NULL;
11973 		/* Generate the log that the tcp_netflix call would have */
11974 		tcp_http_log_req_info(rack->rc_tp, ent,
11975 				      i, TCP_HTTP_REQ_LOG_FREED, 0, 0);
11976 		/* Free it and see if there is another one */
11977 		tcp_http_free_a_slot(rack->rc_tp, ent);
11978 		ent = tcp_http_find_a_req_that_is_completed_by(rack->rc_tp, th_ack, &i);
11979 	}
11980 }
11981 #endif
11982 
11983 
11984 /*
11985  * Return value of 1, we do not need to call rack_process_data().
11986  * return value of 0, rack_process_data can be called.
11987  * For ret_val if its 0 the TCP is locked, if its non-zero
11988  * its unlocked and probably unsafe to touch the TCB.
11989  */
11990 static int
11991 rack_process_ack(struct mbuf *m, struct tcphdr *th, struct socket *so,
11992     struct tcpcb *tp, struct tcpopt *to,
11993     uint32_t tiwin, int32_t tlen,
11994     int32_t * ofia, int32_t thflags, int32_t *ret_val)
11995 {
11996 	int32_t ourfinisacked = 0;
11997 	int32_t nsegs, acked_amount;
11998 	int32_t acked;
11999 	struct mbuf *mfree;
12000 	struct tcp_rack *rack;
12001 	int32_t under_pacing = 0;
12002 	int32_t recovery = 0;
12003 
12004 	INP_WLOCK_ASSERT(tptoinpcb(tp));
12005 
12006 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12007 	if (SEQ_GT(th->th_ack, tp->snd_max)) {
12008 		__ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val,
12009 				      &rack->r_ctl.challenge_ack_ts,
12010 				      &rack->r_ctl.challenge_ack_cnt);
12011 		rack->r_wanted_output = 1;
12012 		return (1);
12013 	}
12014 	if (rack->gp_ready &&
12015 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
12016 		under_pacing = 1;
12017 	}
12018 	if (SEQ_GEQ(th->th_ack, tp->snd_una) || to->to_nsacks) {
12019 		int in_rec, dup_ack_struck = 0;
12020 		int dsack_seen = 0, sacks_seen = 0;
12021 
12022 		in_rec = IN_FASTRECOVERY(tp->t_flags);
12023 		if (rack->rc_in_persist) {
12024 			tp->t_rxtshift = 0;
12025 			RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
12026 				      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
12027 		}
12028 
12029 		if ((th->th_ack == tp->snd_una) &&
12030 		    (tiwin == tp->snd_wnd) &&
12031 		    ((to->to_flags & TOF_SACK) == 0)) {
12032 			rack_strike_dupack(rack);
12033 			dup_ack_struck = 1;
12034 		}
12035 		rack_log_ack(tp, to, th, ((in_rec == 0) && IN_FASTRECOVERY(tp->t_flags)),
12036 			     dup_ack_struck, &dsack_seen, &sacks_seen);
12037 		if ((rack->sack_attack_disable > 0) &&
12038 		    (th->th_ack == tp->snd_una) &&
12039 		    (tiwin == tp->snd_wnd) &&
12040 		    (dsack_seen == 0) &&
12041 		    (sacks_seen > 0)) {
12042 			/*
12043 			 * If sacks have been disabled we may
12044 			 * want to strike a dup-ack "ignoring" the
12045 			 * sack as long as the sack was not a "dsack". Note
12046 			 * that if no sack is sent (TOF_SACK is off) then the
12047 			 * normal dsack code above rack_log_ack() would have
12048 			 * already struck. So this is just to catch the case
12049 			 * were we are ignoring sacks from this guy due to
12050 			 * it being a suspected attacker.
12051 			 */
12052 			rack_strike_dupack(rack);
12053 		}
12054 
12055 	}
12056 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
12057 		/*
12058 		 * Old ack, behind (or duplicate to) the last one rcv'd
12059 		 * Note: We mark reordering is occuring if its
12060 		 * less than and we have not closed our window.
12061 		 */
12062 		if (SEQ_LT(th->th_ack, tp->snd_una) && (sbspace(&so->so_rcv) > ctf_fixed_maxseg(tp))) {
12063 			rack->r_ctl.rc_reorder_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
12064 			if (rack->r_ctl.rc_reorder_ts == 0)
12065 				rack->r_ctl.rc_reorder_ts = 1;
12066 		}
12067 		return (0);
12068 	}
12069 	/*
12070 	 * If we reach this point, ACK is not a duplicate, i.e., it ACKs
12071 	 * something we sent.
12072 	 */
12073 	if (tp->t_flags & TF_NEEDSYN) {
12074 		/*
12075 		 * T/TCP: Connection was half-synchronized, and our SYN has
12076 		 * been ACK'd (so connection is now fully synchronized).  Go
12077 		 * to non-starred state, increment snd_una for ACK of SYN,
12078 		 * and check if we can do window scaling.
12079 		 */
12080 		tp->t_flags &= ~TF_NEEDSYN;
12081 		tp->snd_una++;
12082 		/* Do window scaling? */
12083 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
12084 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
12085 			tp->rcv_scale = tp->request_r_scale;
12086 			/* Send window already scaled. */
12087 		}
12088 	}
12089 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
12090 
12091 	acked = BYTES_THIS_ACK(tp, th);
12092 	if (acked) {
12093 		/*
12094 		 * Any time we move the cum-ack forward clear
12095 		 * keep-alive tied probe-not-answered. The
12096 		 * persists clears its own on entry.
12097 		 */
12098 		rack->probe_not_answered = 0;
12099 	}
12100 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
12101 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
12102 	/*
12103 	 * If we just performed our first retransmit, and the ACK arrives
12104 	 * within our recovery window, then it was a mistake to do the
12105 	 * retransmit in the first place.  Recover our original cwnd and
12106 	 * ssthresh, and proceed to transmit where we left off.
12107 	 */
12108 	if ((tp->t_flags & TF_PREVVALID) &&
12109 	    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
12110 		tp->t_flags &= ~TF_PREVVALID;
12111 		if (tp->t_rxtshift == 1 &&
12112 		    (int)(ticks - tp->t_badrxtwin) < 0)
12113 			rack_cong_signal(tp, CC_RTO_ERR, th->th_ack, __LINE__);
12114 	}
12115 	if (acked) {
12116 		/* assure we are not backed off */
12117 		tp->t_rxtshift = 0;
12118 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
12119 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
12120 		rack->rc_tlp_in_progress = 0;
12121 		rack->r_ctl.rc_tlp_cnt_out = 0;
12122 		/*
12123 		 * If it is the RXT timer we want to
12124 		 * stop it, so we can restart a TLP.
12125 		 */
12126 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
12127 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
12128 #ifdef TCP_REQUEST_TRK
12129 		rack_http_check_for_comp(rack, th->th_ack);
12130 #endif
12131 	}
12132 	/*
12133 	 * If we have a timestamp reply, update smoothed round trip time. If
12134 	 * no timestamp is present but transmit timer is running and timed
12135 	 * sequence number was acked, update smoothed round trip time. Since
12136 	 * we now have an rtt measurement, cancel the timer backoff (cf.,
12137 	 * Phil Karn's retransmit alg.). Recompute the initial retransmit
12138 	 * timer.
12139 	 *
12140 	 * Some boxes send broken timestamp replies during the SYN+ACK
12141 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
12142 	 * and blow up the retransmit timer.
12143 	 */
12144 	/*
12145 	 * If all outstanding data is acked, stop retransmit timer and
12146 	 * remember to restart (more output or persist). If there is more
12147 	 * data to be acked, restart retransmit timer, using current
12148 	 * (possibly backed-off) value.
12149 	 */
12150 	if (acked == 0) {
12151 		if (ofia)
12152 			*ofia = ourfinisacked;
12153 		return (0);
12154 	}
12155 	if (IN_RECOVERY(tp->t_flags)) {
12156 		if (SEQ_LT(th->th_ack, tp->snd_recover) &&
12157 		    (SEQ_LT(th->th_ack, tp->snd_max))) {
12158 			tcp_rack_partialack(tp);
12159 		} else {
12160 			rack_post_recovery(tp, th->th_ack);
12161 			recovery = 1;
12162 		}
12163 	}
12164 	/*
12165 	 * Let the congestion control algorithm update congestion control
12166 	 * related information. This typically means increasing the
12167 	 * congestion window.
12168 	 */
12169 	rack_ack_received(tp, rack, th->th_ack, nsegs, CC_ACK, recovery);
12170 	SOCKBUF_LOCK(&so->so_snd);
12171 	acked_amount = min(acked, (int)sbavail(&so->so_snd));
12172 	tp->snd_wnd -= acked_amount;
12173 	mfree = sbcut_locked(&so->so_snd, acked_amount);
12174 	if ((sbused(&so->so_snd) == 0) &&
12175 	    (acked > acked_amount) &&
12176 	    (tp->t_state >= TCPS_FIN_WAIT_1) &&
12177 	    (tp->t_flags & TF_SENTFIN)) {
12178 		/*
12179 		 * We must be sure our fin
12180 		 * was sent and acked (we can be
12181 		 * in FIN_WAIT_1 without having
12182 		 * sent the fin).
12183 		 */
12184 		ourfinisacked = 1;
12185 	}
12186 	tp->snd_una = th->th_ack;
12187 	/* wakeups? */
12188 	if (acked_amount && sbavail(&so->so_snd))
12189 		rack_adjust_sendmap_head(rack, &so->so_snd);
12190 	rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
12191 	/* NB: sowwakeup_locked() does an implicit unlock. */
12192 	sowwakeup_locked(so);
12193 	/* now check the rxt clamps */
12194 	if ((recovery == 1) &&
12195 	    (rack->excess_rxt_on) &&
12196 	    (rack->r_cwnd_was_clamped == 0))  {
12197 		do_rack_excess_rxt(tp, rack);
12198 	} else if (rack->r_cwnd_was_clamped)
12199 		do_rack_check_for_unclamp(tp, rack);
12200 	m_freem(mfree);
12201 	if (SEQ_GT(tp->snd_una, tp->snd_recover))
12202 		tp->snd_recover = tp->snd_una;
12203 
12204 	if (SEQ_LT(tp->snd_nxt, tp->snd_una)) {
12205 		tp->snd_nxt = tp->snd_una;
12206 	}
12207 	if (under_pacing &&
12208 	    (rack->use_fixed_rate == 0) &&
12209 	    (rack->in_probe_rtt == 0) &&
12210 	    rack->rc_gp_dyn_mul &&
12211 	    rack->rc_always_pace) {
12212 		/* Check if we are dragging bottom */
12213 		rack_check_bottom_drag(tp, rack, so);
12214 	}
12215 	if (tp->snd_una == tp->snd_max) {
12216 		/* Nothing left outstanding */
12217 		tp->t_flags &= ~TF_PREVVALID;
12218 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
12219 		rack->r_ctl.retran_during_recovery = 0;
12220 		rack->r_ctl.dsack_byte_cnt = 0;
12221 		if (rack->r_ctl.rc_went_idle_time == 0)
12222 			rack->r_ctl.rc_went_idle_time = 1;
12223 		rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
12224 		if (sbavail(&tptosocket(tp)->so_snd) == 0)
12225 			tp->t_acktime = 0;
12226 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
12227 		rack->rc_suspicious = 0;
12228 		/* Set need output so persist might get set */
12229 		rack->r_wanted_output = 1;
12230 		sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
12231 		if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
12232 		    (sbavail(&so->so_snd) == 0) &&
12233 		    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
12234 			/*
12235 			 * The socket was gone and the
12236 			 * peer sent data (now or in the past), time to
12237 			 * reset him.
12238 			 */
12239 			*ret_val = 1;
12240 			/* tcp_close will kill the inp pre-log the Reset */
12241 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
12242 			tp = tcp_close(tp);
12243 			ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, tlen);
12244 			return (1);
12245 		}
12246 	}
12247 	if (ofia)
12248 		*ofia = ourfinisacked;
12249 	return (0);
12250 }
12251 
12252 
12253 static void
12254 rack_log_collapse(struct tcp_rack *rack, uint32_t cnt, uint32_t split, uint32_t out, int line,
12255 		  int dir, uint32_t flags, struct rack_sendmap *rsm)
12256 {
12257 	if (tcp_bblogging_on(rack->rc_tp)) {
12258 		union tcp_log_stackspecific log;
12259 		struct timeval tv;
12260 
12261 		memset(&log, 0, sizeof(log));
12262 		log.u_bbr.flex1 = cnt;
12263 		log.u_bbr.flex2 = split;
12264 		log.u_bbr.flex3 = out;
12265 		log.u_bbr.flex4 = line;
12266 		log.u_bbr.flex5 = rack->r_must_retran;
12267 		log.u_bbr.flex6 = flags;
12268 		log.u_bbr.flex7 = rack->rc_has_collapsed;
12269 		log.u_bbr.flex8 = dir;	/*
12270 					 * 1 is collapsed, 0 is uncollapsed,
12271 					 * 2 is log of a rsm being marked, 3 is a split.
12272 					 */
12273 		if (rsm == NULL)
12274 			log.u_bbr.rttProp = 0;
12275 		else
12276 			log.u_bbr.rttProp = (uint64_t)rsm;
12277 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
12278 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
12279 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
12280 		    &rack->rc_inp->inp_socket->so_rcv,
12281 		    &rack->rc_inp->inp_socket->so_snd,
12282 		    TCP_RACK_LOG_COLLAPSE, 0,
12283 		    0, &log, false, &tv);
12284 	}
12285 }
12286 
12287 static void
12288 rack_collapsed_window(struct tcp_rack *rack, uint32_t out, tcp_seq th_ack, int line)
12289 {
12290 	/*
12291 	 * Here all we do is mark the collapsed point and set the flag.
12292 	 * This may happen again and again, but there is no
12293 	 * sense splitting our map until we know where the
12294 	 * peer finally lands in the collapse.
12295 	 */
12296 	tcp_trace_point(rack->rc_tp, TCP_TP_COLLAPSED_WND);
12297 	if ((rack->rc_has_collapsed == 0) ||
12298 	    (rack->r_ctl.last_collapse_point != (th_ack + rack->rc_tp->snd_wnd)))
12299 		counter_u64_add(rack_collapsed_win_seen, 1);
12300 	rack->r_ctl.last_collapse_point = th_ack + rack->rc_tp->snd_wnd;
12301 	rack->r_ctl.high_collapse_point = rack->rc_tp->snd_max;
12302 	rack->rc_has_collapsed = 1;
12303 	rack->r_collapse_point_valid = 1;
12304 	rack_log_collapse(rack, 0, th_ack, rack->r_ctl.last_collapse_point, line, 1, 0, NULL);
12305 }
12306 
12307 static void
12308 rack_un_collapse_window(struct tcp_rack *rack, int line)
12309 {
12310 	struct rack_sendmap *nrsm, *rsm;
12311 	int cnt = 0, split = 0;
12312 	int insret __diagused;
12313 
12314 
12315 	tcp_trace_point(rack->rc_tp, TCP_TP_COLLAPSED_WND);
12316 	rack->rc_has_collapsed = 0;
12317 	rsm = tqhash_find(rack->r_ctl.tqh, rack->r_ctl.last_collapse_point);
12318 	if (rsm == NULL) {
12319 		/* Nothing to do maybe the peer ack'ed it all */
12320 		rack_log_collapse(rack, 0, 0, ctf_outstanding(rack->rc_tp), line, 0, 0, NULL);
12321 		return;
12322 	}
12323 	/* Now do we need to split this one? */
12324 	if (SEQ_GT(rack->r_ctl.last_collapse_point, rsm->r_start)) {
12325 		rack_log_collapse(rack, rsm->r_start, rsm->r_end,
12326 				  rack->r_ctl.last_collapse_point, line, 3, rsm->r_flags, rsm);
12327 		nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
12328 		if (nrsm == NULL) {
12329 			/* We can't get a rsm, mark all? */
12330 			nrsm = rsm;
12331 			goto no_split;
12332 		}
12333 		/* Clone it */
12334 		split = 1;
12335 		rack_clone_rsm(rack, nrsm, rsm, rack->r_ctl.last_collapse_point);
12336 #ifndef INVARIANTS
12337 		(void)tqhash_insert(rack->r_ctl.tqh, nrsm);
12338 #else
12339 		if ((insret = tqhash_insert(rack->r_ctl.tqh, nrsm)) != 0) {
12340 			panic("Insert in rb tree of %p fails ret:%d rack:%p rsm:%p",
12341 			      nrsm, insret, rack, rsm);
12342 		}
12343 #endif
12344 		rack_log_map_chg(rack->rc_tp, rack, NULL, rsm, nrsm, MAP_SPLIT,
12345 				 rack->r_ctl.last_collapse_point, __LINE__);
12346 		if (rsm->r_in_tmap) {
12347 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
12348 			nrsm->r_in_tmap = 1;
12349 		}
12350 		/*
12351 		 * Set in the new RSM as the
12352 		 * collapsed starting point
12353 		 */
12354 		rsm = nrsm;
12355 	}
12356 
12357 no_split:
12358 	TQHASH_FOREACH_FROM(nrsm, rack->r_ctl.tqh, rsm)  {
12359 		cnt++;
12360 		nrsm->r_flags |= RACK_RWND_COLLAPSED;
12361 		rack_log_collapse(rack, nrsm->r_start, nrsm->r_end, 0, line, 4, nrsm->r_flags, nrsm);
12362 		cnt++;
12363 	}
12364 	if (cnt) {
12365 		counter_u64_add(rack_collapsed_win, 1);
12366 	}
12367 	rack_log_collapse(rack, cnt, split, ctf_outstanding(rack->rc_tp), line, 0, 0, NULL);
12368 }
12369 
12370 static void
12371 rack_handle_delayed_ack(struct tcpcb *tp, struct tcp_rack *rack,
12372 			int32_t tlen, int32_t tfo_syn)
12373 {
12374 	if (DELAY_ACK(tp, tlen) || tfo_syn) {
12375 		rack_timer_cancel(tp, rack,
12376 				  rack->r_ctl.rc_rcvtime, __LINE__);
12377 		tp->t_flags |= TF_DELACK;
12378 	} else {
12379 		rack->r_wanted_output = 1;
12380 		tp->t_flags |= TF_ACKNOW;
12381 	}
12382 }
12383 
12384 static void
12385 rack_validate_fo_sendwin_up(struct tcpcb *tp, struct tcp_rack *rack)
12386 {
12387 	/*
12388 	 * If fast output is in progress, lets validate that
12389 	 * the new window did not shrink on us and make it
12390 	 * so fast output should end.
12391 	 */
12392 	if (rack->r_fast_output) {
12393 		uint32_t out;
12394 
12395 		/*
12396 		 * Calculate what we will send if left as is
12397 		 * and compare that to our send window.
12398 		 */
12399 		out = ctf_outstanding(tp);
12400 		if ((out + rack->r_ctl.fsb.left_to_send) > tp->snd_wnd) {
12401 			/* ok we have an issue */
12402 			if (out >= tp->snd_wnd) {
12403 				/* Turn off fast output the window is met or collapsed */
12404 				rack->r_fast_output = 0;
12405 			} else {
12406 				/* we have some room left */
12407 				rack->r_ctl.fsb.left_to_send = tp->snd_wnd - out;
12408 				if (rack->r_ctl.fsb.left_to_send < ctf_fixed_maxseg(tp)) {
12409 					/* If not at least 1 full segment never mind */
12410 					rack->r_fast_output = 0;
12411 				}
12412 			}
12413 		}
12414 	}
12415 }
12416 
12417 
12418 /*
12419  * Return value of 1, the TCB is unlocked and most
12420  * likely gone, return value of 0, the TCP is still
12421  * locked.
12422  */
12423 static int
12424 rack_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so,
12425     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
12426     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
12427 {
12428 	/*
12429 	 * Update window information. Don't look at window if no ACK: TAC's
12430 	 * send garbage on first SYN.
12431 	 */
12432 	int32_t nsegs;
12433 	int32_t tfo_syn;
12434 	struct tcp_rack *rack;
12435 
12436 	INP_WLOCK_ASSERT(tptoinpcb(tp));
12437 
12438 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12439 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
12440 	if ((thflags & TH_ACK) &&
12441 	    (SEQ_LT(tp->snd_wl1, th->th_seq) ||
12442 	    (tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) ||
12443 	    (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) {
12444 		/* keep track of pure window updates */
12445 		if (tlen == 0 &&
12446 		    tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd)
12447 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
12448 		tp->snd_wnd = tiwin;
12449 		rack_validate_fo_sendwin_up(tp, rack);
12450 		tp->snd_wl1 = th->th_seq;
12451 		tp->snd_wl2 = th->th_ack;
12452 		if (tp->snd_wnd > tp->max_sndwnd)
12453 			tp->max_sndwnd = tp->snd_wnd;
12454 		rack->r_wanted_output = 1;
12455 	} else if (thflags & TH_ACK) {
12456 		if ((tp->snd_wl2 == th->th_ack) && (tiwin < tp->snd_wnd)) {
12457 			tp->snd_wnd = tiwin;
12458 			rack_validate_fo_sendwin_up(tp, rack);
12459 			tp->snd_wl1 = th->th_seq;
12460 			tp->snd_wl2 = th->th_ack;
12461 		}
12462 	}
12463 	if (tp->snd_wnd < ctf_outstanding(tp))
12464 		/* The peer collapsed the window */
12465 		rack_collapsed_window(rack, ctf_outstanding(tp), th->th_ack, __LINE__);
12466 	else if (rack->rc_has_collapsed)
12467 		rack_un_collapse_window(rack, __LINE__);
12468 	if ((rack->r_collapse_point_valid) &&
12469 	    (SEQ_GT(th->th_ack, rack->r_ctl.high_collapse_point)))
12470 		rack->r_collapse_point_valid = 0;
12471 	/* Was persist timer active and now we have window space? */
12472 	if ((rack->rc_in_persist != 0) &&
12473 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
12474 				rack->r_ctl.rc_pace_min_segs))) {
12475 		rack_exit_persist(tp, rack, rack->r_ctl.rc_rcvtime);
12476 		tp->snd_nxt = tp->snd_max;
12477 		/* Make sure we output to start the timer */
12478 		rack->r_wanted_output = 1;
12479 	}
12480 	/* Do we enter persists? */
12481 	if ((rack->rc_in_persist == 0) &&
12482 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
12483 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
12484 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
12485 	    sbavail(&tptosocket(tp)->so_snd) &&
12486 	    (sbavail(&tptosocket(tp)->so_snd) > tp->snd_wnd)) {
12487 		/*
12488 		 * Here the rwnd is less than
12489 		 * the pacing size, we are established,
12490 		 * nothing is outstanding, and there is
12491 		 * data to send. Enter persists.
12492 		 */
12493 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime, tp->snd_una);
12494 	}
12495 	if (tp->t_flags2 & TF2_DROP_AF_DATA) {
12496 		m_freem(m);
12497 		return (0);
12498 	}
12499 	/*
12500 	 * don't process the URG bit, ignore them drag
12501 	 * along the up.
12502 	 */
12503 	tp->rcv_up = tp->rcv_nxt;
12504 
12505 	/*
12506 	 * Process the segment text, merging it into the TCP sequencing
12507 	 * queue, and arranging for acknowledgment of receipt if necessary.
12508 	 * This process logically involves adjusting tp->rcv_wnd as data is
12509 	 * presented to the user (this happens in tcp_usrreq.c, case
12510 	 * PRU_RCVD).  If a FIN has already been received on this connection
12511 	 * then we just ignore the text.
12512 	 */
12513 	tfo_syn = ((tp->t_state == TCPS_SYN_RECEIVED) &&
12514 		   IS_FASTOPEN(tp->t_flags));
12515 	if ((tlen || (thflags & TH_FIN) || (tfo_syn && tlen > 0)) &&
12516 	    TCPS_HAVERCVDFIN(tp->t_state) == 0) {
12517 		tcp_seq save_start = th->th_seq;
12518 		tcp_seq save_rnxt  = tp->rcv_nxt;
12519 		int     save_tlen  = tlen;
12520 
12521 		m_adj(m, drop_hdrlen);	/* delayed header drop */
12522 		/*
12523 		 * Insert segment which includes th into TCP reassembly
12524 		 * queue with control block tp.  Set thflags to whether
12525 		 * reassembly now includes a segment with FIN.  This handles
12526 		 * the common case inline (segment is the next to be
12527 		 * received on an established connection, and the queue is
12528 		 * empty), avoiding linkage into and removal from the queue
12529 		 * and repetition of various conversions. Set DELACK for
12530 		 * segments received in order, but ack immediately when
12531 		 * segments are out of order (so fast retransmit can work).
12532 		 */
12533 		if (th->th_seq == tp->rcv_nxt &&
12534 		    SEGQ_EMPTY(tp) &&
12535 		    (TCPS_HAVEESTABLISHED(tp->t_state) ||
12536 		    tfo_syn)) {
12537 #ifdef NETFLIX_SB_LIMITS
12538 			u_int mcnt, appended;
12539 
12540 			if (so->so_rcv.sb_shlim) {
12541 				mcnt = m_memcnt(m);
12542 				appended = 0;
12543 				if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
12544 				    CFO_NOSLEEP, NULL) == false) {
12545 					counter_u64_add(tcp_sb_shlim_fails, 1);
12546 					m_freem(m);
12547 					return (0);
12548 				}
12549 			}
12550 #endif
12551 			rack_handle_delayed_ack(tp, rack, tlen, tfo_syn);
12552 			tp->rcv_nxt += tlen;
12553 			if (tlen &&
12554 			    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
12555 			    (tp->t_fbyte_in == 0)) {
12556 				tp->t_fbyte_in = ticks;
12557 				if (tp->t_fbyte_in == 0)
12558 					tp->t_fbyte_in = 1;
12559 				if (tp->t_fbyte_out && tp->t_fbyte_in)
12560 					tp->t_flags2 |= TF2_FBYTES_COMPLETE;
12561 			}
12562 			thflags = tcp_get_flags(th) & TH_FIN;
12563 			KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
12564 			KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
12565 			SOCKBUF_LOCK(&so->so_rcv);
12566 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
12567 				m_freem(m);
12568 			} else
12569 #ifdef NETFLIX_SB_LIMITS
12570 				appended =
12571 #endif
12572 					sbappendstream_locked(&so->so_rcv, m, 0);
12573 
12574 			rack_log_wakeup(tp,rack, &so->so_rcv, tlen, 1);
12575 			/* NB: sorwakeup_locked() does an implicit unlock. */
12576 			sorwakeup_locked(so);
12577 #ifdef NETFLIX_SB_LIMITS
12578 			if (so->so_rcv.sb_shlim && appended != mcnt)
12579 				counter_fo_release(so->so_rcv.sb_shlim,
12580 				    mcnt - appended);
12581 #endif
12582 		} else {
12583 			/*
12584 			 * XXX: Due to the header drop above "th" is
12585 			 * theoretically invalid by now.  Fortunately
12586 			 * m_adj() doesn't actually frees any mbufs when
12587 			 * trimming from the head.
12588 			 */
12589 			tcp_seq temp = save_start;
12590 
12591 			thflags = tcp_reass(tp, th, &temp, &tlen, m);
12592 			tp->t_flags |= TF_ACKNOW;
12593 			if (tp->t_flags & TF_WAKESOR) {
12594 				tp->t_flags &= ~TF_WAKESOR;
12595 				/* NB: sorwakeup_locked() does an implicit unlock. */
12596 				sorwakeup_locked(so);
12597 			}
12598 		}
12599 		if ((tp->t_flags & TF_SACK_PERMIT) &&
12600 		    (save_tlen > 0) &&
12601 		    TCPS_HAVEESTABLISHED(tp->t_state)) {
12602 			if ((tlen == 0) && (SEQ_LT(save_start, save_rnxt))) {
12603 				/*
12604 				 * DSACK actually handled in the fastpath
12605 				 * above.
12606 				 */
12607 				tcp_update_sack_list(tp, save_start,
12608 				    save_start + save_tlen);
12609 			} else if ((tlen > 0) && SEQ_GT(tp->rcv_nxt, save_rnxt)) {
12610 				if ((tp->rcv_numsacks >= 1) &&
12611 				    (tp->sackblks[0].end == save_start)) {
12612 					/*
12613 					 * Partial overlap, recorded at todrop
12614 					 * above.
12615 					 */
12616 					tcp_update_sack_list(tp,
12617 					    tp->sackblks[0].start,
12618 					    tp->sackblks[0].end);
12619 				} else {
12620 					tcp_update_dsack_list(tp, save_start,
12621 					    save_start + save_tlen);
12622 				}
12623 			} else if (tlen >= save_tlen) {
12624 				/* Update of sackblks. */
12625 				tcp_update_dsack_list(tp, save_start,
12626 				    save_start + save_tlen);
12627 			} else if (tlen > 0) {
12628 				tcp_update_dsack_list(tp, save_start,
12629 				    save_start + tlen);
12630 			}
12631 		}
12632 	} else {
12633 		m_freem(m);
12634 		thflags &= ~TH_FIN;
12635 	}
12636 
12637 	/*
12638 	 * If FIN is received ACK the FIN and let the user know that the
12639 	 * connection is closing.
12640 	 */
12641 	if (thflags & TH_FIN) {
12642 		if (TCPS_HAVERCVDFIN(tp->t_state) == 0) {
12643 			/* The socket upcall is handled by socantrcvmore. */
12644 			socantrcvmore(so);
12645 			/*
12646 			 * If connection is half-synchronized (ie NEEDSYN
12647 			 * flag on) then delay ACK, so it may be piggybacked
12648 			 * when SYN is sent. Otherwise, since we received a
12649 			 * FIN then no more input can be expected, send ACK
12650 			 * now.
12651 			 */
12652 			if (tp->t_flags & TF_NEEDSYN) {
12653 				rack_timer_cancel(tp, rack,
12654 				    rack->r_ctl.rc_rcvtime, __LINE__);
12655 				tp->t_flags |= TF_DELACK;
12656 			} else {
12657 				tp->t_flags |= TF_ACKNOW;
12658 			}
12659 			tp->rcv_nxt++;
12660 		}
12661 		switch (tp->t_state) {
12662 			/*
12663 			 * In SYN_RECEIVED and ESTABLISHED STATES enter the
12664 			 * CLOSE_WAIT state.
12665 			 */
12666 		case TCPS_SYN_RECEIVED:
12667 			tp->t_starttime = ticks;
12668 			/* FALLTHROUGH */
12669 		case TCPS_ESTABLISHED:
12670 			rack_timer_cancel(tp, rack,
12671 			    rack->r_ctl.rc_rcvtime, __LINE__);
12672 			tcp_state_change(tp, TCPS_CLOSE_WAIT);
12673 			break;
12674 
12675 			/*
12676 			 * If still in FIN_WAIT_1 STATE FIN has not been
12677 			 * acked so enter the CLOSING state.
12678 			 */
12679 		case TCPS_FIN_WAIT_1:
12680 			rack_timer_cancel(tp, rack,
12681 			    rack->r_ctl.rc_rcvtime, __LINE__);
12682 			tcp_state_change(tp, TCPS_CLOSING);
12683 			break;
12684 
12685 			/*
12686 			 * In FIN_WAIT_2 state enter the TIME_WAIT state,
12687 			 * starting the time-wait timer, turning off the
12688 			 * other standard timers.
12689 			 */
12690 		case TCPS_FIN_WAIT_2:
12691 			rack_timer_cancel(tp, rack,
12692 			    rack->r_ctl.rc_rcvtime, __LINE__);
12693 			tcp_twstart(tp);
12694 			return (1);
12695 		}
12696 	}
12697 	/*
12698 	 * Return any desired output.
12699 	 */
12700 	if ((tp->t_flags & TF_ACKNOW) ||
12701 	    (sbavail(&so->so_snd) > (tp->snd_max - tp->snd_una))) {
12702 		rack->r_wanted_output = 1;
12703 	}
12704 	return (0);
12705 }
12706 
12707 /*
12708  * Here nothing is really faster, its just that we
12709  * have broken out the fast-data path also just like
12710  * the fast-ack.
12711  */
12712 static int
12713 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th, struct socket *so,
12714     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12715     uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos)
12716 {
12717 	int32_t nsegs;
12718 	int32_t newsize = 0;	/* automatic sockbuf scaling */
12719 	struct tcp_rack *rack;
12720 #ifdef NETFLIX_SB_LIMITS
12721 	u_int mcnt, appended;
12722 #endif
12723 
12724 	/*
12725 	 * If last ACK falls within this segment's sequence numbers, record
12726 	 * the timestamp. NOTE that the test is modified according to the
12727 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
12728 	 */
12729 	if (__predict_false(th->th_seq != tp->rcv_nxt)) {
12730 		return (0);
12731 	}
12732 	if (__predict_false(tp->snd_nxt != tp->snd_max)) {
12733 		return (0);
12734 	}
12735 	if (tiwin && tiwin != tp->snd_wnd) {
12736 		return (0);
12737 	}
12738 	if (__predict_false((tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN)))) {
12739 		return (0);
12740 	}
12741 	if (__predict_false((to->to_flags & TOF_TS) &&
12742 	    (TSTMP_LT(to->to_tsval, tp->ts_recent)))) {
12743 		return (0);
12744 	}
12745 	if (__predict_false((th->th_ack != tp->snd_una))) {
12746 		return (0);
12747 	}
12748 	if (__predict_false(tlen > sbspace(&so->so_rcv))) {
12749 		return (0);
12750 	}
12751 	if ((to->to_flags & TOF_TS) != 0 &&
12752 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
12753 		tp->ts_recent_age = tcp_ts_getticks();
12754 		tp->ts_recent = to->to_tsval;
12755 	}
12756 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12757 	/*
12758 	 * This is a pure, in-sequence data packet with nothing on the
12759 	 * reassembly queue and we have enough buffer space to take it.
12760 	 */
12761 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
12762 
12763 #ifdef NETFLIX_SB_LIMITS
12764 	if (so->so_rcv.sb_shlim) {
12765 		mcnt = m_memcnt(m);
12766 		appended = 0;
12767 		if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
12768 		    CFO_NOSLEEP, NULL) == false) {
12769 			counter_u64_add(tcp_sb_shlim_fails, 1);
12770 			m_freem(m);
12771 			return (1);
12772 		}
12773 	}
12774 #endif
12775 	/* Clean receiver SACK report if present */
12776 	if (tp->rcv_numsacks)
12777 		tcp_clean_sackreport(tp);
12778 	KMOD_TCPSTAT_INC(tcps_preddat);
12779 	tp->rcv_nxt += tlen;
12780 	if (tlen &&
12781 	    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
12782 	    (tp->t_fbyte_in == 0)) {
12783 		tp->t_fbyte_in = ticks;
12784 		if (tp->t_fbyte_in == 0)
12785 			tp->t_fbyte_in = 1;
12786 		if (tp->t_fbyte_out && tp->t_fbyte_in)
12787 			tp->t_flags2 |= TF2_FBYTES_COMPLETE;
12788 	}
12789 	/*
12790 	 * Pull snd_wl1 up to prevent seq wrap relative to th_seq.
12791 	 */
12792 	tp->snd_wl1 = th->th_seq;
12793 	/*
12794 	 * Pull rcv_up up to prevent seq wrap relative to rcv_nxt.
12795 	 */
12796 	tp->rcv_up = tp->rcv_nxt;
12797 	KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
12798 	KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
12799 	newsize = tcp_autorcvbuf(m, th, so, tp, tlen);
12800 
12801 	/* Add data to socket buffer. */
12802 	SOCKBUF_LOCK(&so->so_rcv);
12803 	if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
12804 		m_freem(m);
12805 	} else {
12806 		/*
12807 		 * Set new socket buffer size. Give up when limit is
12808 		 * reached.
12809 		 */
12810 		if (newsize)
12811 			if (!sbreserve_locked(so, SO_RCV, newsize, NULL))
12812 				so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
12813 		m_adj(m, drop_hdrlen);	/* delayed header drop */
12814 #ifdef NETFLIX_SB_LIMITS
12815 		appended =
12816 #endif
12817 			sbappendstream_locked(&so->so_rcv, m, 0);
12818 		ctf_calc_rwin(so, tp);
12819 	}
12820 	rack_log_wakeup(tp,rack, &so->so_rcv, tlen, 1);
12821 	/* NB: sorwakeup_locked() does an implicit unlock. */
12822 	sorwakeup_locked(so);
12823 #ifdef NETFLIX_SB_LIMITS
12824 	if (so->so_rcv.sb_shlim && mcnt != appended)
12825 		counter_fo_release(so->so_rcv.sb_shlim, mcnt - appended);
12826 #endif
12827 	rack_handle_delayed_ack(tp, rack, tlen, 0);
12828 	if (tp->snd_una == tp->snd_max)
12829 		sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
12830 	return (1);
12831 }
12832 
12833 /*
12834  * This subfunction is used to try to highly optimize the
12835  * fast path. We again allow window updates that are
12836  * in sequence to remain in the fast-path. We also add
12837  * in the __predict's to attempt to help the compiler.
12838  * Note that if we return a 0, then we can *not* process
12839  * it and the caller should push the packet into the
12840  * slow-path.
12841  */
12842 static int
12843 rack_fastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
12844     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12845     uint32_t tiwin, int32_t nxt_pkt, uint32_t cts)
12846 {
12847 	int32_t acked;
12848 	int32_t nsegs;
12849 	int32_t under_pacing = 0;
12850 	struct tcp_rack *rack;
12851 
12852 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
12853 		/* Old ack, behind (or duplicate to) the last one rcv'd */
12854 		return (0);
12855 	}
12856 	if (__predict_false(SEQ_GT(th->th_ack, tp->snd_max))) {
12857 		/* Above what we have sent? */
12858 		return (0);
12859 	}
12860 	if (__predict_false(tp->snd_nxt != tp->snd_max)) {
12861 		/* We are retransmitting */
12862 		return (0);
12863 	}
12864 	if (__predict_false(tiwin == 0)) {
12865 		/* zero window */
12866 		return (0);
12867 	}
12868 	if (__predict_false(tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN))) {
12869 		/* We need a SYN or a FIN, unlikely.. */
12870 		return (0);
12871 	}
12872 	if ((to->to_flags & TOF_TS) && __predict_false(TSTMP_LT(to->to_tsval, tp->ts_recent))) {
12873 		/* Timestamp is behind .. old ack with seq wrap? */
12874 		return (0);
12875 	}
12876 	if (__predict_false(IN_RECOVERY(tp->t_flags))) {
12877 		/* Still recovering */
12878 		return (0);
12879 	}
12880 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12881 	if (rack->r_ctl.rc_sacked) {
12882 		/* We have sack holes on our scoreboard */
12883 		return (0);
12884 	}
12885 	/* Ok if we reach here, we can process a fast-ack */
12886 	if (rack->gp_ready &&
12887 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
12888 		under_pacing = 1;
12889 	}
12890 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
12891 	rack_log_ack(tp, to, th, 0, 0, NULL, NULL);
12892 	/* Did the window get updated? */
12893 	if (tiwin != tp->snd_wnd) {
12894 		tp->snd_wnd = tiwin;
12895 		rack_validate_fo_sendwin_up(tp, rack);
12896 		tp->snd_wl1 = th->th_seq;
12897 		if (tp->snd_wnd > tp->max_sndwnd)
12898 			tp->max_sndwnd = tp->snd_wnd;
12899 	}
12900 	/* Do we exit persists? */
12901 	if ((rack->rc_in_persist != 0) &&
12902 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
12903 			       rack->r_ctl.rc_pace_min_segs))) {
12904 		rack_exit_persist(tp, rack, cts);
12905 	}
12906 	/* Do we enter persists? */
12907 	if ((rack->rc_in_persist == 0) &&
12908 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
12909 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
12910 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
12911 	    sbavail(&tptosocket(tp)->so_snd) &&
12912 	    (sbavail(&tptosocket(tp)->so_snd) > tp->snd_wnd)) {
12913 		/*
12914 		 * Here the rwnd is less than
12915 		 * the pacing size, we are established,
12916 		 * nothing is outstanding, and there is
12917 		 * data to send. Enter persists.
12918 		 */
12919 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime, th->th_ack);
12920 	}
12921 	/*
12922 	 * If last ACK falls within this segment's sequence numbers, record
12923 	 * the timestamp. NOTE that the test is modified according to the
12924 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
12925 	 */
12926 	if ((to->to_flags & TOF_TS) != 0 &&
12927 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
12928 		tp->ts_recent_age = tcp_ts_getticks();
12929 		tp->ts_recent = to->to_tsval;
12930 	}
12931 	/*
12932 	 * This is a pure ack for outstanding data.
12933 	 */
12934 	KMOD_TCPSTAT_INC(tcps_predack);
12935 
12936 	/*
12937 	 * "bad retransmit" recovery.
12938 	 */
12939 	if ((tp->t_flags & TF_PREVVALID) &&
12940 	    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
12941 		tp->t_flags &= ~TF_PREVVALID;
12942 		if (tp->t_rxtshift == 1 &&
12943 		    (int)(ticks - tp->t_badrxtwin) < 0)
12944 			rack_cong_signal(tp, CC_RTO_ERR, th->th_ack, __LINE__);
12945 	}
12946 	/*
12947 	 * Recalculate the transmit timer / rtt.
12948 	 *
12949 	 * Some boxes send broken timestamp replies during the SYN+ACK
12950 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
12951 	 * and blow up the retransmit timer.
12952 	 */
12953 	acked = BYTES_THIS_ACK(tp, th);
12954 
12955 #ifdef TCP_HHOOK
12956 	/* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */
12957 	hhook_run_tcp_est_in(tp, th, to);
12958 #endif
12959 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
12960 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
12961 	if (acked) {
12962 		struct mbuf *mfree;
12963 
12964 		rack_ack_received(tp, rack, th->th_ack, nsegs, CC_ACK, 0);
12965 		SOCKBUF_LOCK(&so->so_snd);
12966 		mfree = sbcut_locked(&so->so_snd, acked);
12967 		tp->snd_una = th->th_ack;
12968 		/* Note we want to hold the sb lock through the sendmap adjust */
12969 		rack_adjust_sendmap_head(rack, &so->so_snd);
12970 		/* Wake up the socket if we have room to write more */
12971 		rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
12972 		sowwakeup_locked(so);
12973 		m_freem(mfree);
12974 		tp->t_rxtshift = 0;
12975 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
12976 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
12977 		rack->rc_tlp_in_progress = 0;
12978 		rack->r_ctl.rc_tlp_cnt_out = 0;
12979 		/*
12980 		 * If it is the RXT timer we want to
12981 		 * stop it, so we can restart a TLP.
12982 		 */
12983 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
12984 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
12985 
12986 #ifdef TCP_REQUEST_TRK
12987 		rack_http_check_for_comp(rack, th->th_ack);
12988 #endif
12989 	}
12990 	/*
12991 	 * Let the congestion control algorithm update congestion control
12992 	 * related information. This typically means increasing the
12993 	 * congestion window.
12994 	 */
12995 	if (tp->snd_wnd < ctf_outstanding(tp)) {
12996 		/* The peer collapsed the window */
12997 		rack_collapsed_window(rack, ctf_outstanding(tp), th->th_ack, __LINE__);
12998 	} else if (rack->rc_has_collapsed)
12999 		rack_un_collapse_window(rack, __LINE__);
13000 	if ((rack->r_collapse_point_valid) &&
13001 	    (SEQ_GT(tp->snd_una, rack->r_ctl.high_collapse_point)))
13002 		rack->r_collapse_point_valid = 0;
13003 	/*
13004 	 * Pull snd_wl2 up to prevent seq wrap relative to th_ack.
13005 	 */
13006 	tp->snd_wl2 = th->th_ack;
13007 	tp->t_dupacks = 0;
13008 	m_freem(m);
13009 	/* ND6_HINT(tp);	 *//* Some progress has been made. */
13010 
13011 	/*
13012 	 * If all outstanding data are acked, stop retransmit timer,
13013 	 * otherwise restart timer using current (possibly backed-off)
13014 	 * value. If process is waiting for space, wakeup/selwakeup/signal.
13015 	 * If data are ready to send, let tcp_output decide between more
13016 	 * output or persist.
13017 	 */
13018 	if (under_pacing &&
13019 	    (rack->use_fixed_rate == 0) &&
13020 	    (rack->in_probe_rtt == 0) &&
13021 	    rack->rc_gp_dyn_mul &&
13022 	    rack->rc_always_pace) {
13023 		/* Check if we are dragging bottom */
13024 		rack_check_bottom_drag(tp, rack, so);
13025 	}
13026 	if (tp->snd_una == tp->snd_max) {
13027 		tp->t_flags &= ~TF_PREVVALID;
13028 		rack->r_ctl.retran_during_recovery = 0;
13029 		rack->rc_suspicious = 0;
13030 		rack->r_ctl.dsack_byte_cnt = 0;
13031 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
13032 		if (rack->r_ctl.rc_went_idle_time == 0)
13033 			rack->r_ctl.rc_went_idle_time = 1;
13034 		rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
13035 		if (sbavail(&tptosocket(tp)->so_snd) == 0)
13036 			tp->t_acktime = 0;
13037 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13038 	}
13039 	if (acked && rack->r_fast_output)
13040 		rack_gain_for_fastoutput(rack, tp, so, (uint32_t)acked);
13041 	if (sbavail(&so->so_snd)) {
13042 		rack->r_wanted_output = 1;
13043 	}
13044 	return (1);
13045 }
13046 
13047 /*
13048  * Return value of 1, the TCB is unlocked and most
13049  * likely gone, return value of 0, the TCP is still
13050  * locked.
13051  */
13052 static int
13053 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th, struct socket *so,
13054     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13055     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13056 {
13057 	int32_t ret_val = 0;
13058 	int32_t todrop;
13059 	int32_t ourfinisacked = 0;
13060 	struct tcp_rack *rack;
13061 
13062 	INP_WLOCK_ASSERT(tptoinpcb(tp));
13063 
13064 	ctf_calc_rwin(so, tp);
13065 	/*
13066 	 * If the state is SYN_SENT: if seg contains an ACK, but not for our
13067 	 * SYN, drop the input. if seg contains a RST, then drop the
13068 	 * connection. if seg does not contain SYN, then drop it. Otherwise
13069 	 * this is an acceptable SYN segment initialize tp->rcv_nxt and
13070 	 * tp->irs if seg contains ack then advance tp->snd_una if seg
13071 	 * contains an ECE and ECN support is enabled, the stream is ECN
13072 	 * capable. if SYN has been acked change to ESTABLISHED else
13073 	 * SYN_RCVD state arrange for segment to be acked (eventually)
13074 	 * continue processing rest of data/controls.
13075 	 */
13076 	if ((thflags & TH_ACK) &&
13077 	    (SEQ_LEQ(th->th_ack, tp->iss) ||
13078 	    SEQ_GT(th->th_ack, tp->snd_max))) {
13079 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
13080 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
13081 		return (1);
13082 	}
13083 	if ((thflags & (TH_ACK | TH_RST)) == (TH_ACK | TH_RST)) {
13084 		TCP_PROBE5(connect__refused, NULL, tp,
13085 		    mtod(m, const char *), tp, th);
13086 		tp = tcp_drop(tp, ECONNREFUSED);
13087 		ctf_do_drop(m, tp);
13088 		return (1);
13089 	}
13090 	if (thflags & TH_RST) {
13091 		ctf_do_drop(m, tp);
13092 		return (1);
13093 	}
13094 	if (!(thflags & TH_SYN)) {
13095 		ctf_do_drop(m, tp);
13096 		return (1);
13097 	}
13098 	tp->irs = th->th_seq;
13099 	tcp_rcvseqinit(tp);
13100 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13101 	if (thflags & TH_ACK) {
13102 		int tfo_partial = 0;
13103 
13104 		KMOD_TCPSTAT_INC(tcps_connects);
13105 		soisconnected(so);
13106 #ifdef MAC
13107 		mac_socketpeer_set_from_mbuf(m, so);
13108 #endif
13109 		/* Do window scaling on this connection? */
13110 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
13111 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
13112 			tp->rcv_scale = tp->request_r_scale;
13113 		}
13114 		tp->rcv_adv += min(tp->rcv_wnd,
13115 		    TCP_MAXWIN << tp->rcv_scale);
13116 		/*
13117 		 * If not all the data that was sent in the TFO SYN
13118 		 * has been acked, resend the remainder right away.
13119 		 */
13120 		if (IS_FASTOPEN(tp->t_flags) &&
13121 		    (tp->snd_una != tp->snd_max)) {
13122 			tp->snd_nxt = th->th_ack;
13123 			tfo_partial = 1;
13124 		}
13125 		/*
13126 		 * If there's data, delay ACK; if there's also a FIN ACKNOW
13127 		 * will be turned on later.
13128 		 */
13129 		if (DELAY_ACK(tp, tlen) && tlen != 0 && !tfo_partial) {
13130 			rack_timer_cancel(tp, rack,
13131 					  rack->r_ctl.rc_rcvtime, __LINE__);
13132 			tp->t_flags |= TF_DELACK;
13133 		} else {
13134 			rack->r_wanted_output = 1;
13135 			tp->t_flags |= TF_ACKNOW;
13136 		}
13137 
13138 		tcp_ecn_input_syn_sent(tp, thflags, iptos);
13139 
13140 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
13141 			/*
13142 			 * We advance snd_una for the
13143 			 * fast open case. If th_ack is
13144 			 * acknowledging data beyond
13145 			 * snd_una we can't just call
13146 			 * ack-processing since the
13147 			 * data stream in our send-map
13148 			 * will start at snd_una + 1 (one
13149 			 * beyond the SYN). If its just
13150 			 * equal we don't need to do that
13151 			 * and there is no send_map.
13152 			 */
13153 			tp->snd_una++;
13154 		}
13155 		/*
13156 		 * Received <SYN,ACK> in SYN_SENT[*] state. Transitions:
13157 		 * SYN_SENT  --> ESTABLISHED SYN_SENT* --> FIN_WAIT_1
13158 		 */
13159 		tp->t_starttime = ticks;
13160 		if (tp->t_flags & TF_NEEDFIN) {
13161 			tcp_state_change(tp, TCPS_FIN_WAIT_1);
13162 			tp->t_flags &= ~TF_NEEDFIN;
13163 			thflags &= ~TH_SYN;
13164 		} else {
13165 			tcp_state_change(tp, TCPS_ESTABLISHED);
13166 			TCP_PROBE5(connect__established, NULL, tp,
13167 			    mtod(m, const char *), tp, th);
13168 			rack_cc_conn_init(tp);
13169 		}
13170 	} else {
13171 		/*
13172 		 * Received initial SYN in SYN-SENT[*] state => simultaneous
13173 		 * open.  If segment contains CC option and there is a
13174 		 * cached CC, apply TAO test. If it succeeds, connection is *
13175 		 * half-synchronized. Otherwise, do 3-way handshake:
13176 		 * SYN-SENT -> SYN-RECEIVED SYN-SENT* -> SYN-RECEIVED* If
13177 		 * there was no CC option, clear cached CC value.
13178 		 */
13179 		tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN | TF_SONOTCONN);
13180 		tcp_state_change(tp, TCPS_SYN_RECEIVED);
13181 	}
13182 	/*
13183 	 * Advance th->th_seq to correspond to first data byte. If data,
13184 	 * trim to stay within window, dropping FIN if necessary.
13185 	 */
13186 	th->th_seq++;
13187 	if (tlen > tp->rcv_wnd) {
13188 		todrop = tlen - tp->rcv_wnd;
13189 		m_adj(m, -todrop);
13190 		tlen = tp->rcv_wnd;
13191 		thflags &= ~TH_FIN;
13192 		KMOD_TCPSTAT_INC(tcps_rcvpackafterwin);
13193 		KMOD_TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop);
13194 	}
13195 	tp->snd_wl1 = th->th_seq - 1;
13196 	tp->rcv_up = th->th_seq;
13197 	/*
13198 	 * Client side of transaction: already sent SYN and data. If the
13199 	 * remote host used T/TCP to validate the SYN, our data will be
13200 	 * ACK'd; if so, enter normal data segment processing in the middle
13201 	 * of step 5, ack processing. Otherwise, goto step 6.
13202 	 */
13203 	if (thflags & TH_ACK) {
13204 		/* For syn-sent we need to possibly update the rtt */
13205 		if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
13206 			uint32_t t, mcts;
13207 
13208 			mcts = tcp_ts_getticks();
13209 			t = (mcts - to->to_tsecr) * HPTS_USEC_IN_MSEC;
13210 			if (!tp->t_rttlow || tp->t_rttlow > t)
13211 				tp->t_rttlow = t;
13212 			rack_log_rtt_sample_calc(rack, t, (to->to_tsecr * 1000), (mcts * 1000), 4);
13213 			tcp_rack_xmit_timer(rack, t + 1, 1, t, 0, NULL, 2);
13214 			tcp_rack_xmit_timer_commit(rack, tp);
13215 		}
13216 		if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val))
13217 			return (ret_val);
13218 		/* We may have changed to FIN_WAIT_1 above */
13219 		if (tp->t_state == TCPS_FIN_WAIT_1) {
13220 			/*
13221 			 * In FIN_WAIT_1 STATE in addition to the processing
13222 			 * for the ESTABLISHED state if our FIN is now
13223 			 * acknowledged then enter FIN_WAIT_2.
13224 			 */
13225 			if (ourfinisacked) {
13226 				/*
13227 				 * If we can't receive any more data, then
13228 				 * closing user can proceed. Starting the
13229 				 * timer is contrary to the specification,
13230 				 * but if we don't get a FIN we'll hang
13231 				 * forever.
13232 				 *
13233 				 * XXXjl: we should release the tp also, and
13234 				 * use a compressed state.
13235 				 */
13236 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13237 					soisdisconnected(so);
13238 					tcp_timer_activate(tp, TT_2MSL,
13239 					    (tcp_fast_finwait2_recycle ?
13240 					    tcp_finwait2_timeout :
13241 					    TP_MAXIDLE(tp)));
13242 				}
13243 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
13244 			}
13245 		}
13246 	}
13247 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13248 	   tiwin, thflags, nxt_pkt));
13249 }
13250 
13251 /*
13252  * Return value of 1, the TCB is unlocked and most
13253  * likely gone, return value of 0, the TCP is still
13254  * locked.
13255  */
13256 static int
13257 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
13258     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13259     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13260 {
13261 	struct tcp_rack *rack;
13262 	int32_t ret_val = 0;
13263 	int32_t ourfinisacked = 0;
13264 
13265 	ctf_calc_rwin(so, tp);
13266 	if ((thflags & TH_ACK) &&
13267 	    (SEQ_LEQ(th->th_ack, tp->snd_una) ||
13268 	    SEQ_GT(th->th_ack, tp->snd_max))) {
13269 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
13270 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
13271 		return (1);
13272 	}
13273 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13274 	if (IS_FASTOPEN(tp->t_flags)) {
13275 		/*
13276 		 * When a TFO connection is in SYN_RECEIVED, the
13277 		 * only valid packets are the initial SYN, a
13278 		 * retransmit/copy of the initial SYN (possibly with
13279 		 * a subset of the original data), a valid ACK, a
13280 		 * FIN, or a RST.
13281 		 */
13282 		if ((thflags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
13283 			tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
13284 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
13285 			return (1);
13286 		} else if (thflags & TH_SYN) {
13287 			/* non-initial SYN is ignored */
13288 			if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT) ||
13289 			    (rack->r_ctl.rc_hpts_flags & PACE_TMR_TLP) ||
13290 			    (rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK)) {
13291 				ctf_do_drop(m, NULL);
13292 				return (0);
13293 			}
13294 		} else if (!(thflags & (TH_ACK | TH_FIN | TH_RST))) {
13295 			ctf_do_drop(m, NULL);
13296 			return (0);
13297 		}
13298 	}
13299 
13300 	if ((thflags & TH_RST) ||
13301 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13302 		return (__ctf_process_rst(m, th, so, tp,
13303 					  &rack->r_ctl.challenge_ack_ts,
13304 					  &rack->r_ctl.challenge_ack_cnt));
13305 	/*
13306 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
13307 	 * it's less than ts_recent, drop it.
13308 	 */
13309 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
13310 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
13311 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13312 			return (ret_val);
13313 	}
13314 	/*
13315 	 * In the SYN-RECEIVED state, validate that the packet belongs to
13316 	 * this connection before trimming the data to fit the receive
13317 	 * window.  Check the sequence number versus IRS since we know the
13318 	 * sequence numbers haven't wrapped.  This is a partial fix for the
13319 	 * "LAND" DoS attack.
13320 	 */
13321 	if (SEQ_LT(th->th_seq, tp->irs)) {
13322 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
13323 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
13324 		return (1);
13325 	}
13326 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
13327 			      &rack->r_ctl.challenge_ack_ts,
13328 			      &rack->r_ctl.challenge_ack_cnt)) {
13329 		return (ret_val);
13330 	}
13331 	/*
13332 	 * If last ACK falls within this segment's sequence numbers, record
13333 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
13334 	 * from the latest proposal of the tcplw@cray.com list (Braden
13335 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
13336 	 * with our earlier PAWS tests, so this check should be solely
13337 	 * predicated on the sequence space of this segment. 3) That we
13338 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
13339 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
13340 	 * SEG.Len, This modified check allows us to overcome RFC1323's
13341 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
13342 	 * p.869. In such cases, we can still calculate the RTT correctly
13343 	 * when RCV.NXT == Last.ACK.Sent.
13344 	 */
13345 	if ((to->to_flags & TOF_TS) != 0 &&
13346 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
13347 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
13348 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
13349 		tp->ts_recent_age = tcp_ts_getticks();
13350 		tp->ts_recent = to->to_tsval;
13351 	}
13352 	tp->snd_wnd = tiwin;
13353 	rack_validate_fo_sendwin_up(tp, rack);
13354 	/*
13355 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
13356 	 * is on (half-synchronized state), then queue data for later
13357 	 * processing; else drop segment and return.
13358 	 */
13359 	if ((thflags & TH_ACK) == 0) {
13360 		if (IS_FASTOPEN(tp->t_flags)) {
13361 			rack_cc_conn_init(tp);
13362 		}
13363 		return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13364 		    tiwin, thflags, nxt_pkt));
13365 	}
13366 	KMOD_TCPSTAT_INC(tcps_connects);
13367 	if (tp->t_flags & TF_SONOTCONN) {
13368 		tp->t_flags &= ~TF_SONOTCONN;
13369 		soisconnected(so);
13370 	}
13371 	/* Do window scaling? */
13372 	if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
13373 	    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
13374 		tp->rcv_scale = tp->request_r_scale;
13375 	}
13376 	/*
13377 	 * Make transitions: SYN-RECEIVED  -> ESTABLISHED SYN-RECEIVED* ->
13378 	 * FIN-WAIT-1
13379 	 */
13380 	tp->t_starttime = ticks;
13381 	if (IS_FASTOPEN(tp->t_flags) && tp->t_tfo_pending) {
13382 		tcp_fastopen_decrement_counter(tp->t_tfo_pending);
13383 		tp->t_tfo_pending = NULL;
13384 	}
13385 	if (tp->t_flags & TF_NEEDFIN) {
13386 		tcp_state_change(tp, TCPS_FIN_WAIT_1);
13387 		tp->t_flags &= ~TF_NEEDFIN;
13388 	} else {
13389 		tcp_state_change(tp, TCPS_ESTABLISHED);
13390 		TCP_PROBE5(accept__established, NULL, tp,
13391 		    mtod(m, const char *), tp, th);
13392 		/*
13393 		 * TFO connections call cc_conn_init() during SYN
13394 		 * processing.  Calling it again here for such connections
13395 		 * is not harmless as it would undo the snd_cwnd reduction
13396 		 * that occurs when a TFO SYN|ACK is retransmitted.
13397 		 */
13398 		if (!IS_FASTOPEN(tp->t_flags))
13399 			rack_cc_conn_init(tp);
13400 	}
13401 	/*
13402 	 * Account for the ACK of our SYN prior to
13403 	 * regular ACK processing below, except for
13404 	 * simultaneous SYN, which is handled later.
13405 	 */
13406 	if (SEQ_GT(th->th_ack, tp->snd_una) && !(tp->t_flags & TF_NEEDSYN))
13407 		tp->snd_una++;
13408 	/*
13409 	 * If segment contains data or ACK, will call tcp_reass() later; if
13410 	 * not, do so now to pass queued data to user.
13411 	 */
13412 	if (tlen == 0 && (thflags & TH_FIN) == 0) {
13413 		(void) tcp_reass(tp, (struct tcphdr *)0, NULL, 0,
13414 		    (struct mbuf *)0);
13415 		if (tp->t_flags & TF_WAKESOR) {
13416 			tp->t_flags &= ~TF_WAKESOR;
13417 			/* NB: sorwakeup_locked() does an implicit unlock. */
13418 			sorwakeup_locked(so);
13419 		}
13420 	}
13421 	tp->snd_wl1 = th->th_seq - 1;
13422 	/* For syn-recv we need to possibly update the rtt */
13423 	if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
13424 		uint32_t t, mcts;
13425 
13426 		mcts = tcp_ts_getticks();
13427 		t = (mcts - to->to_tsecr) * HPTS_USEC_IN_MSEC;
13428 		if (!tp->t_rttlow || tp->t_rttlow > t)
13429 			tp->t_rttlow = t;
13430 		rack_log_rtt_sample_calc(rack, t, (to->to_tsecr * 1000), (mcts * 1000), 5);
13431 		tcp_rack_xmit_timer(rack, t + 1, 1, t, 0, NULL, 2);
13432 		tcp_rack_xmit_timer_commit(rack, tp);
13433 	}
13434 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
13435 		return (ret_val);
13436 	}
13437 	if (tp->t_state == TCPS_FIN_WAIT_1) {
13438 		/* We could have went to FIN_WAIT_1 (or EST) above */
13439 		/*
13440 		 * In FIN_WAIT_1 STATE in addition to the processing for the
13441 		 * ESTABLISHED state if our FIN is now acknowledged then
13442 		 * enter FIN_WAIT_2.
13443 		 */
13444 		if (ourfinisacked) {
13445 			/*
13446 			 * If we can't receive any more data, then closing
13447 			 * user can proceed. Starting the timer is contrary
13448 			 * to the specification, but if we don't get a FIN
13449 			 * we'll hang forever.
13450 			 *
13451 			 * XXXjl: we should release the tp also, and use a
13452 			 * compressed state.
13453 			 */
13454 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13455 				soisdisconnected(so);
13456 				tcp_timer_activate(tp, TT_2MSL,
13457 				    (tcp_fast_finwait2_recycle ?
13458 				    tcp_finwait2_timeout :
13459 				    TP_MAXIDLE(tp)));
13460 			}
13461 			tcp_state_change(tp, TCPS_FIN_WAIT_2);
13462 		}
13463 	}
13464 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13465 	    tiwin, thflags, nxt_pkt));
13466 }
13467 
13468 /*
13469  * Return value of 1, the TCB is unlocked and most
13470  * likely gone, return value of 0, the TCP is still
13471  * locked.
13472  */
13473 static int
13474 rack_do_established(struct mbuf *m, struct tcphdr *th, struct socket *so,
13475     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13476     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13477 {
13478 	int32_t ret_val = 0;
13479 	struct tcp_rack *rack;
13480 
13481 	/*
13482 	 * Header prediction: check for the two common cases of a
13483 	 * uni-directional data xfer.  If the packet has no control flags,
13484 	 * is in-sequence, the window didn't change and we're not
13485 	 * retransmitting, it's a candidate.  If the length is zero and the
13486 	 * ack moved forward, we're the sender side of the xfer.  Just free
13487 	 * the data acked & wake any higher level process that was blocked
13488 	 * waiting for space.  If the length is non-zero and the ack didn't
13489 	 * move, we're the receiver side.  If we're getting packets in-order
13490 	 * (the reassembly queue is empty), add the data toc The socket
13491 	 * buffer and note that we need a delayed ack. Make sure that the
13492 	 * hidden state-flags are also off. Since we check for
13493 	 * TCPS_ESTABLISHED first, it can only be TH_NEEDSYN.
13494 	 */
13495 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13496 	if (__predict_true(((to->to_flags & TOF_SACK) == 0)) &&
13497 	    __predict_true((thflags & (TH_SYN | TH_FIN | TH_RST | TH_ACK)) == TH_ACK) &&
13498 	    __predict_true(SEGQ_EMPTY(tp)) &&
13499 	    __predict_true(th->th_seq == tp->rcv_nxt)) {
13500 		if (tlen == 0) {
13501 			if (rack_fastack(m, th, so, tp, to, drop_hdrlen, tlen,
13502 			    tiwin, nxt_pkt, rack->r_ctl.rc_rcvtime)) {
13503 				return (0);
13504 			}
13505 		} else {
13506 			if (rack_do_fastnewdata(m, th, so, tp, to, drop_hdrlen, tlen,
13507 			    tiwin, nxt_pkt, iptos)) {
13508 				return (0);
13509 			}
13510 		}
13511 	}
13512 	ctf_calc_rwin(so, tp);
13513 
13514 	if ((thflags & TH_RST) ||
13515 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13516 		return (__ctf_process_rst(m, th, so, tp,
13517 					  &rack->r_ctl.challenge_ack_ts,
13518 					  &rack->r_ctl.challenge_ack_cnt));
13519 
13520 	/*
13521 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
13522 	 * synchronized state.
13523 	 */
13524 	if (thflags & TH_SYN) {
13525 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
13526 		return (ret_val);
13527 	}
13528 	/*
13529 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
13530 	 * it's less than ts_recent, drop it.
13531 	 */
13532 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
13533 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
13534 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13535 			return (ret_val);
13536 	}
13537 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
13538 			      &rack->r_ctl.challenge_ack_ts,
13539 			      &rack->r_ctl.challenge_ack_cnt)) {
13540 		return (ret_val);
13541 	}
13542 	/*
13543 	 * If last ACK falls within this segment's sequence numbers, record
13544 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
13545 	 * from the latest proposal of the tcplw@cray.com list (Braden
13546 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
13547 	 * with our earlier PAWS tests, so this check should be solely
13548 	 * predicated on the sequence space of this segment. 3) That we
13549 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
13550 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
13551 	 * SEG.Len, This modified check allows us to overcome RFC1323's
13552 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
13553 	 * p.869. In such cases, we can still calculate the RTT correctly
13554 	 * when RCV.NXT == Last.ACK.Sent.
13555 	 */
13556 	if ((to->to_flags & TOF_TS) != 0 &&
13557 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
13558 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
13559 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
13560 		tp->ts_recent_age = tcp_ts_getticks();
13561 		tp->ts_recent = to->to_tsval;
13562 	}
13563 	/*
13564 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
13565 	 * is on (half-synchronized state), then queue data for later
13566 	 * processing; else drop segment and return.
13567 	 */
13568 	if ((thflags & TH_ACK) == 0) {
13569 		if (tp->t_flags & TF_NEEDSYN) {
13570 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13571 			    tiwin, thflags, nxt_pkt));
13572 
13573 		} else if (tp->t_flags & TF_ACKNOW) {
13574 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
13575 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
13576 			return (ret_val);
13577 		} else {
13578 			ctf_do_drop(m, NULL);
13579 			return (0);
13580 		}
13581 	}
13582 	/*
13583 	 * Ack processing.
13584 	 */
13585 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
13586 		return (ret_val);
13587 	}
13588 	if (sbavail(&so->so_snd)) {
13589 		if (ctf_progress_timeout_check(tp, true)) {
13590 			rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
13591 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
13592 			return (1);
13593 		}
13594 	}
13595 	/* State changes only happen in rack_process_data() */
13596 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13597 	    tiwin, thflags, nxt_pkt));
13598 }
13599 
13600 /*
13601  * Return value of 1, the TCB is unlocked and most
13602  * likely gone, return value of 0, the TCP is still
13603  * locked.
13604  */
13605 static int
13606 rack_do_close_wait(struct mbuf *m, struct tcphdr *th, struct socket *so,
13607     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13608     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13609 {
13610 	int32_t ret_val = 0;
13611 	struct tcp_rack *rack;
13612 
13613 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13614 	ctf_calc_rwin(so, tp);
13615 	if ((thflags & TH_RST) ||
13616 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13617 		return (__ctf_process_rst(m, th, so, tp,
13618 					  &rack->r_ctl.challenge_ack_ts,
13619 					  &rack->r_ctl.challenge_ack_cnt));
13620 	/*
13621 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
13622 	 * synchronized state.
13623 	 */
13624 	if (thflags & TH_SYN) {
13625 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
13626 		return (ret_val);
13627 	}
13628 	/*
13629 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
13630 	 * it's less than ts_recent, drop it.
13631 	 */
13632 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
13633 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
13634 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13635 			return (ret_val);
13636 	}
13637 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
13638 			      &rack->r_ctl.challenge_ack_ts,
13639 			      &rack->r_ctl.challenge_ack_cnt)) {
13640 		return (ret_val);
13641 	}
13642 	/*
13643 	 * If last ACK falls within this segment's sequence numbers, record
13644 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
13645 	 * from the latest proposal of the tcplw@cray.com list (Braden
13646 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
13647 	 * with our earlier PAWS tests, so this check should be solely
13648 	 * predicated on the sequence space of this segment. 3) That we
13649 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
13650 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
13651 	 * SEG.Len, This modified check allows us to overcome RFC1323's
13652 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
13653 	 * p.869. In such cases, we can still calculate the RTT correctly
13654 	 * when RCV.NXT == Last.ACK.Sent.
13655 	 */
13656 	if ((to->to_flags & TOF_TS) != 0 &&
13657 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
13658 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
13659 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
13660 		tp->ts_recent_age = tcp_ts_getticks();
13661 		tp->ts_recent = to->to_tsval;
13662 	}
13663 	/*
13664 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
13665 	 * is on (half-synchronized state), then queue data for later
13666 	 * processing; else drop segment and return.
13667 	 */
13668 	if ((thflags & TH_ACK) == 0) {
13669 		if (tp->t_flags & TF_NEEDSYN) {
13670 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13671 			    tiwin, thflags, nxt_pkt));
13672 
13673 		} else if (tp->t_flags & TF_ACKNOW) {
13674 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
13675 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
13676 			return (ret_val);
13677 		} else {
13678 			ctf_do_drop(m, NULL);
13679 			return (0);
13680 		}
13681 	}
13682 	/*
13683 	 * Ack processing.
13684 	 */
13685 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
13686 		return (ret_val);
13687 	}
13688 	if (sbavail(&so->so_snd)) {
13689 		if (ctf_progress_timeout_check(tp, true)) {
13690 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
13691 						tp, tick, PROGRESS_DROP, __LINE__);
13692 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
13693 			return (1);
13694 		}
13695 	}
13696 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13697 	    tiwin, thflags, nxt_pkt));
13698 }
13699 
13700 static int
13701 rack_check_data_after_close(struct mbuf *m,
13702     struct tcpcb *tp, int32_t *tlen, struct tcphdr *th, struct socket *so)
13703 {
13704 	struct tcp_rack *rack;
13705 
13706 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13707 	if (rack->rc_allow_data_af_clo == 0) {
13708 	close_now:
13709 		tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
13710 		/* tcp_close will kill the inp pre-log the Reset */
13711 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
13712 		tp = tcp_close(tp);
13713 		KMOD_TCPSTAT_INC(tcps_rcvafterclose);
13714 		ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, (*tlen));
13715 		return (1);
13716 	}
13717 	if (sbavail(&so->so_snd) == 0)
13718 		goto close_now;
13719 	/* Ok we allow data that is ignored and a followup reset */
13720 	tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
13721 	tp->rcv_nxt = th->th_seq + *tlen;
13722 	tp->t_flags2 |= TF2_DROP_AF_DATA;
13723 	rack->r_wanted_output = 1;
13724 	*tlen = 0;
13725 	return (0);
13726 }
13727 
13728 /*
13729  * Return value of 1, the TCB is unlocked and most
13730  * likely gone, return value of 0, the TCP is still
13731  * locked.
13732  */
13733 static int
13734 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, struct socket *so,
13735     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13736     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13737 {
13738 	int32_t ret_val = 0;
13739 	int32_t ourfinisacked = 0;
13740 	struct tcp_rack *rack;
13741 
13742 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13743 	ctf_calc_rwin(so, tp);
13744 
13745 	if ((thflags & TH_RST) ||
13746 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13747 		return (__ctf_process_rst(m, th, so, tp,
13748 					  &rack->r_ctl.challenge_ack_ts,
13749 					  &rack->r_ctl.challenge_ack_cnt));
13750 	/*
13751 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
13752 	 * synchronized state.
13753 	 */
13754 	if (thflags & TH_SYN) {
13755 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
13756 		return (ret_val);
13757 	}
13758 	/*
13759 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
13760 	 * it's less than ts_recent, drop it.
13761 	 */
13762 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
13763 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
13764 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13765 			return (ret_val);
13766 	}
13767 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
13768 			      &rack->r_ctl.challenge_ack_ts,
13769 			      &rack->r_ctl.challenge_ack_cnt)) {
13770 		return (ret_val);
13771 	}
13772 	/*
13773 	 * If new data are received on a connection after the user processes
13774 	 * are gone, then RST the other end.
13775 	 */
13776 	if ((tp->t_flags & TF_CLOSED) && tlen &&
13777 	    rack_check_data_after_close(m, tp, &tlen, th, so))
13778 		return (1);
13779 	/*
13780 	 * If last ACK falls within this segment's sequence numbers, record
13781 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
13782 	 * from the latest proposal of the tcplw@cray.com list (Braden
13783 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
13784 	 * with our earlier PAWS tests, so this check should be solely
13785 	 * predicated on the sequence space of this segment. 3) That we
13786 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
13787 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
13788 	 * SEG.Len, This modified check allows us to overcome RFC1323's
13789 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
13790 	 * p.869. In such cases, we can still calculate the RTT correctly
13791 	 * when RCV.NXT == Last.ACK.Sent.
13792 	 */
13793 	if ((to->to_flags & TOF_TS) != 0 &&
13794 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
13795 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
13796 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
13797 		tp->ts_recent_age = tcp_ts_getticks();
13798 		tp->ts_recent = to->to_tsval;
13799 	}
13800 	/*
13801 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
13802 	 * is on (half-synchronized state), then queue data for later
13803 	 * processing; else drop segment and return.
13804 	 */
13805 	if ((thflags & TH_ACK) == 0) {
13806 		if (tp->t_flags & TF_NEEDSYN) {
13807 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13808 			    tiwin, thflags, nxt_pkt));
13809 		} else if (tp->t_flags & TF_ACKNOW) {
13810 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
13811 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
13812 			return (ret_val);
13813 		} else {
13814 			ctf_do_drop(m, NULL);
13815 			return (0);
13816 		}
13817 	}
13818 	/*
13819 	 * Ack processing.
13820 	 */
13821 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
13822 		return (ret_val);
13823 	}
13824 	if (ourfinisacked) {
13825 		/*
13826 		 * If we can't receive any more data, then closing user can
13827 		 * proceed. Starting the timer is contrary to the
13828 		 * specification, but if we don't get a FIN we'll hang
13829 		 * forever.
13830 		 *
13831 		 * XXXjl: we should release the tp also, and use a
13832 		 * compressed state.
13833 		 */
13834 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13835 			soisdisconnected(so);
13836 			tcp_timer_activate(tp, TT_2MSL,
13837 			    (tcp_fast_finwait2_recycle ?
13838 			    tcp_finwait2_timeout :
13839 			    TP_MAXIDLE(tp)));
13840 		}
13841 		tcp_state_change(tp, TCPS_FIN_WAIT_2);
13842 	}
13843 	if (sbavail(&so->so_snd)) {
13844 		if (ctf_progress_timeout_check(tp, true)) {
13845 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
13846 						tp, tick, PROGRESS_DROP, __LINE__);
13847 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
13848 			return (1);
13849 		}
13850 	}
13851 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13852 	    tiwin, thflags, nxt_pkt));
13853 }
13854 
13855 /*
13856  * Return value of 1, the TCB is unlocked and most
13857  * likely gone, return value of 0, the TCP is still
13858  * locked.
13859  */
13860 static int
13861 rack_do_closing(struct mbuf *m, struct tcphdr *th, struct socket *so,
13862     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13863     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13864 {
13865 	int32_t ret_val = 0;
13866 	int32_t ourfinisacked = 0;
13867 	struct tcp_rack *rack;
13868 
13869 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13870 	ctf_calc_rwin(so, tp);
13871 
13872 	if ((thflags & TH_RST) ||
13873 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13874 		return (__ctf_process_rst(m, th, so, tp,
13875 					  &rack->r_ctl.challenge_ack_ts,
13876 					  &rack->r_ctl.challenge_ack_cnt));
13877 	/*
13878 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
13879 	 * synchronized state.
13880 	 */
13881 	if (thflags & TH_SYN) {
13882 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
13883 		return (ret_val);
13884 	}
13885 	/*
13886 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
13887 	 * it's less than ts_recent, drop it.
13888 	 */
13889 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
13890 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
13891 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
13892 			return (ret_val);
13893 	}
13894 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
13895 			      &rack->r_ctl.challenge_ack_ts,
13896 			      &rack->r_ctl.challenge_ack_cnt)) {
13897 		return (ret_val);
13898 	}
13899 	/*
13900 	 * If new data are received on a connection after the user processes
13901 	 * are gone, then RST the other end.
13902 	 */
13903 	if ((tp->t_flags & TF_CLOSED) && tlen &&
13904 	    rack_check_data_after_close(m, tp, &tlen, th, so))
13905 		return (1);
13906 	/*
13907 	 * If last ACK falls within this segment's sequence numbers, record
13908 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
13909 	 * from the latest proposal of the tcplw@cray.com list (Braden
13910 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
13911 	 * with our earlier PAWS tests, so this check should be solely
13912 	 * predicated on the sequence space of this segment. 3) That we
13913 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
13914 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
13915 	 * SEG.Len, This modified check allows us to overcome RFC1323's
13916 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
13917 	 * p.869. In such cases, we can still calculate the RTT correctly
13918 	 * when RCV.NXT == Last.ACK.Sent.
13919 	 */
13920 	if ((to->to_flags & TOF_TS) != 0 &&
13921 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
13922 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
13923 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
13924 		tp->ts_recent_age = tcp_ts_getticks();
13925 		tp->ts_recent = to->to_tsval;
13926 	}
13927 	/*
13928 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
13929 	 * is on (half-synchronized state), then queue data for later
13930 	 * processing; else drop segment and return.
13931 	 */
13932 	if ((thflags & TH_ACK) == 0) {
13933 		if (tp->t_flags & TF_NEEDSYN) {
13934 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13935 			    tiwin, thflags, nxt_pkt));
13936 		} else if (tp->t_flags & TF_ACKNOW) {
13937 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
13938 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
13939 			return (ret_val);
13940 		} else {
13941 			ctf_do_drop(m, NULL);
13942 			return (0);
13943 		}
13944 	}
13945 	/*
13946 	 * Ack processing.
13947 	 */
13948 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
13949 		return (ret_val);
13950 	}
13951 	if (ourfinisacked) {
13952 		tcp_twstart(tp);
13953 		m_freem(m);
13954 		return (1);
13955 	}
13956 	if (sbavail(&so->so_snd)) {
13957 		if (ctf_progress_timeout_check(tp, true)) {
13958 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
13959 						tp, tick, PROGRESS_DROP, __LINE__);
13960 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
13961 			return (1);
13962 		}
13963 	}
13964 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
13965 	    tiwin, thflags, nxt_pkt));
13966 }
13967 
13968 /*
13969  * Return value of 1, the TCB is unlocked and most
13970  * likely gone, return value of 0, the TCP is still
13971  * locked.
13972  */
13973 static int
13974 rack_do_lastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
13975     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
13976     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
13977 {
13978 	int32_t ret_val = 0;
13979 	int32_t ourfinisacked = 0;
13980 	struct tcp_rack *rack;
13981 
13982 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13983 	ctf_calc_rwin(so, tp);
13984 
13985 	if ((thflags & TH_RST) ||
13986 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
13987 		return (__ctf_process_rst(m, th, so, tp,
13988 					  &rack->r_ctl.challenge_ack_ts,
13989 					  &rack->r_ctl.challenge_ack_cnt));
13990 	/*
13991 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
13992 	 * synchronized state.
13993 	 */
13994 	if (thflags & TH_SYN) {
13995 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
13996 		return (ret_val);
13997 	}
13998 	/*
13999 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
14000 	 * it's less than ts_recent, drop it.
14001 	 */
14002 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
14003 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
14004 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
14005 			return (ret_val);
14006 	}
14007 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
14008 			      &rack->r_ctl.challenge_ack_ts,
14009 			      &rack->r_ctl.challenge_ack_cnt)) {
14010 		return (ret_val);
14011 	}
14012 	/*
14013 	 * If new data are received on a connection after the user processes
14014 	 * are gone, then RST the other end.
14015 	 */
14016 	if ((tp->t_flags & TF_CLOSED) && tlen &&
14017 	    rack_check_data_after_close(m, tp, &tlen, th, so))
14018 		return (1);
14019 	/*
14020 	 * If last ACK falls within this segment's sequence numbers, record
14021 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
14022 	 * from the latest proposal of the tcplw@cray.com list (Braden
14023 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
14024 	 * with our earlier PAWS tests, so this check should be solely
14025 	 * predicated on the sequence space of this segment. 3) That we
14026 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
14027 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
14028 	 * SEG.Len, This modified check allows us to overcome RFC1323's
14029 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
14030 	 * p.869. In such cases, we can still calculate the RTT correctly
14031 	 * when RCV.NXT == Last.ACK.Sent.
14032 	 */
14033 	if ((to->to_flags & TOF_TS) != 0 &&
14034 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
14035 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
14036 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
14037 		tp->ts_recent_age = tcp_ts_getticks();
14038 		tp->ts_recent = to->to_tsval;
14039 	}
14040 	/*
14041 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
14042 	 * is on (half-synchronized state), then queue data for later
14043 	 * processing; else drop segment and return.
14044 	 */
14045 	if ((thflags & TH_ACK) == 0) {
14046 		if (tp->t_flags & TF_NEEDSYN) {
14047 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
14048 			    tiwin, thflags, nxt_pkt));
14049 		} else if (tp->t_flags & TF_ACKNOW) {
14050 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
14051 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
14052 			return (ret_val);
14053 		} else {
14054 			ctf_do_drop(m, NULL);
14055 			return (0);
14056 		}
14057 	}
14058 	/*
14059 	 * case TCPS_LAST_ACK: Ack processing.
14060 	 */
14061 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
14062 		return (ret_val);
14063 	}
14064 	if (ourfinisacked) {
14065 		tp = tcp_close(tp);
14066 		ctf_do_drop(m, tp);
14067 		return (1);
14068 	}
14069 	if (sbavail(&so->so_snd)) {
14070 		if (ctf_progress_timeout_check(tp, true)) {
14071 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
14072 						tp, tick, PROGRESS_DROP, __LINE__);
14073 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
14074 			return (1);
14075 		}
14076 	}
14077 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
14078 	    tiwin, thflags, nxt_pkt));
14079 }
14080 
14081 /*
14082  * Return value of 1, the TCB is unlocked and most
14083  * likely gone, return value of 0, the TCP is still
14084  * locked.
14085  */
14086 static int
14087 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, struct socket *so,
14088     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
14089     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
14090 {
14091 	int32_t ret_val = 0;
14092 	int32_t ourfinisacked = 0;
14093 	struct tcp_rack *rack;
14094 
14095 	rack = (struct tcp_rack *)tp->t_fb_ptr;
14096 	ctf_calc_rwin(so, tp);
14097 
14098 	/* Reset receive buffer auto scaling when not in bulk receive mode. */
14099 	if ((thflags & TH_RST) ||
14100 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
14101 		return (__ctf_process_rst(m, th, so, tp,
14102 					  &rack->r_ctl.challenge_ack_ts,
14103 					  &rack->r_ctl.challenge_ack_cnt));
14104 	/*
14105 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
14106 	 * synchronized state.
14107 	 */
14108 	if (thflags & TH_SYN) {
14109 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
14110 		return (ret_val);
14111 	}
14112 	/*
14113 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
14114 	 * it's less than ts_recent, drop it.
14115 	 */
14116 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
14117 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
14118 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
14119 			return (ret_val);
14120 	}
14121 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
14122 			      &rack->r_ctl.challenge_ack_ts,
14123 			      &rack->r_ctl.challenge_ack_cnt)) {
14124 		return (ret_val);
14125 	}
14126 	/*
14127 	 * If new data are received on a connection after the user processes
14128 	 * are gone, then RST the other end.
14129 	 */
14130 	if ((tp->t_flags & TF_CLOSED) && tlen &&
14131 	    rack_check_data_after_close(m, tp, &tlen, th, so))
14132 		return (1);
14133 	/*
14134 	 * If last ACK falls within this segment's sequence numbers, record
14135 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
14136 	 * from the latest proposal of the tcplw@cray.com list (Braden
14137 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
14138 	 * with our earlier PAWS tests, so this check should be solely
14139 	 * predicated on the sequence space of this segment. 3) That we
14140 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
14141 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
14142 	 * SEG.Len, This modified check allows us to overcome RFC1323's
14143 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
14144 	 * p.869. In such cases, we can still calculate the RTT correctly
14145 	 * when RCV.NXT == Last.ACK.Sent.
14146 	 */
14147 	if ((to->to_flags & TOF_TS) != 0 &&
14148 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
14149 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
14150 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
14151 		tp->ts_recent_age = tcp_ts_getticks();
14152 		tp->ts_recent = to->to_tsval;
14153 	}
14154 	/*
14155 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
14156 	 * is on (half-synchronized state), then queue data for later
14157 	 * processing; else drop segment and return.
14158 	 */
14159 	if ((thflags & TH_ACK) == 0) {
14160 		if (tp->t_flags & TF_NEEDSYN) {
14161 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
14162 			    tiwin, thflags, nxt_pkt));
14163 		} else if (tp->t_flags & TF_ACKNOW) {
14164 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
14165 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
14166 			return (ret_val);
14167 		} else {
14168 			ctf_do_drop(m, NULL);
14169 			return (0);
14170 		}
14171 	}
14172 	/*
14173 	 * Ack processing.
14174 	 */
14175 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
14176 		return (ret_val);
14177 	}
14178 	if (sbavail(&so->so_snd)) {
14179 		if (ctf_progress_timeout_check(tp, true)) {
14180 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
14181 						tp, tick, PROGRESS_DROP, __LINE__);
14182 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
14183 			return (1);
14184 		}
14185 	}
14186 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
14187 	    tiwin, thflags, nxt_pkt));
14188 }
14189 
14190 static void inline
14191 rack_clear_rate_sample(struct tcp_rack *rack)
14192 {
14193 	rack->r_ctl.rack_rs.rs_flags = RACK_RTT_EMPTY;
14194 	rack->r_ctl.rack_rs.rs_rtt_cnt = 0;
14195 	rack->r_ctl.rack_rs.rs_rtt_tot = 0;
14196 }
14197 
14198 static void
14199 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line, uint64_t *fill_override)
14200 {
14201 	uint64_t bw_est, rate_wanted;
14202 	int chged = 0;
14203 	uint32_t user_max, orig_min, orig_max;
14204 
14205 #ifdef TCP_REQUEST_TRK
14206 	if (rack->rc_hybrid_mode &&
14207 	    (rack->r_ctl.rc_pace_max_segs != 0) &&
14208 	    (rack_hybrid_allow_set_maxseg == 1) &&
14209 	    (rack->r_ctl.rc_last_sft != NULL)) {
14210 		rack->r_ctl.rc_last_sft->hybrid_flags &= ~TCP_HYBRID_PACING_SETMSS;
14211 		return;
14212 	}
14213 #endif
14214 	orig_min = rack->r_ctl.rc_pace_min_segs;
14215 	orig_max = rack->r_ctl.rc_pace_max_segs;
14216 	user_max = ctf_fixed_maxseg(tp) * rack->rc_user_set_max_segs;
14217 	if (ctf_fixed_maxseg(tp) != rack->r_ctl.rc_pace_min_segs)
14218 		chged = 1;
14219 	rack->r_ctl.rc_pace_min_segs = ctf_fixed_maxseg(tp);
14220 	if (rack->use_fixed_rate || rack->rc_force_max_seg) {
14221 		if (user_max != rack->r_ctl.rc_pace_max_segs)
14222 			chged = 1;
14223 	}
14224 	if (rack->rc_force_max_seg) {
14225 		rack->r_ctl.rc_pace_max_segs = user_max;
14226 	} else if (rack->use_fixed_rate) {
14227 		bw_est = rack_get_bw(rack);
14228 		if ((rack->r_ctl.crte == NULL) ||
14229 		    (bw_est != rack->r_ctl.crte->rate)) {
14230 			rack->r_ctl.rc_pace_max_segs = user_max;
14231 		} else {
14232 			/* We are pacing right at the hardware rate */
14233 			uint32_t segsiz, pace_one;
14234 
14235 			if (rack_pace_one_seg ||
14236 			    (rack->r_ctl.rc_user_set_min_segs == 1))
14237 				pace_one = 1;
14238 			else
14239 				pace_one = 0;
14240 			segsiz = min(ctf_fixed_maxseg(tp),
14241 				     rack->r_ctl.rc_pace_min_segs);
14242 			rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size_w_divisor(
14243 				tp, bw_est, segsiz, pace_one,
14244 				rack->r_ctl.crte, NULL, rack->r_ctl.pace_len_divisor);
14245 		}
14246 	} else if (rack->rc_always_pace) {
14247 		if (rack->r_ctl.gp_bw ||
14248 		    rack->r_ctl.init_rate) {
14249 			/* We have a rate of some sort set */
14250 			uint32_t  orig;
14251 
14252 			bw_est = rack_get_bw(rack);
14253 			orig = rack->r_ctl.rc_pace_max_segs;
14254 			if (fill_override)
14255 				rate_wanted = *fill_override;
14256 			else
14257 				rate_wanted = rack_get_output_bw(rack, bw_est, NULL, NULL);
14258 			if (rate_wanted) {
14259 				/* We have something */
14260 				rack->r_ctl.rc_pace_max_segs = rack_get_pacing_len(rack,
14261 										   rate_wanted,
14262 										   ctf_fixed_maxseg(rack->rc_tp));
14263 			} else
14264 				rack->r_ctl.rc_pace_max_segs = rack->r_ctl.rc_pace_min_segs;
14265 			if (orig != rack->r_ctl.rc_pace_max_segs)
14266 				chged = 1;
14267 		} else if ((rack->r_ctl.gp_bw == 0) &&
14268 			   (rack->r_ctl.rc_pace_max_segs == 0)) {
14269 			/*
14270 			 * If we have nothing limit us to bursting
14271 			 * out IW sized pieces.
14272 			 */
14273 			chged = 1;
14274 			rack->r_ctl.rc_pace_max_segs = rc_init_window(rack);
14275 		}
14276 	}
14277 	if (rack->r_ctl.rc_pace_max_segs > PACE_MAX_IP_BYTES) {
14278 		chged = 1;
14279 		rack->r_ctl.rc_pace_max_segs = PACE_MAX_IP_BYTES;
14280 	}
14281 	if (chged)
14282 		rack_log_type_pacing_sizes(tp, rack, orig_min, orig_max, line, 2);
14283 }
14284 
14285 
14286 static void
14287 rack_init_fsb_block(struct tcpcb *tp, struct tcp_rack *rack, int32_t flags)
14288 {
14289 #ifdef INET6
14290 	struct ip6_hdr *ip6 = NULL;
14291 #endif
14292 #ifdef INET
14293 	struct ip *ip = NULL;
14294 #endif
14295 	struct udphdr *udp = NULL;
14296 
14297 	/* Ok lets fill in the fast block, it can only be used with no IP options! */
14298 #ifdef INET6
14299 	if (rack->r_is_v6) {
14300 		rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
14301 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
14302 		if (tp->t_port) {
14303 			rack->r_ctl.fsb.tcp_ip_hdr_len += sizeof(struct udphdr);
14304 			udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
14305 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
14306 			udp->uh_dport = tp->t_port;
14307 			rack->r_ctl.fsb.udp = udp;
14308 			rack->r_ctl.fsb.th = (struct tcphdr *)(udp + 1);
14309 		} else
14310 		{
14311 			rack->r_ctl.fsb.th = (struct tcphdr *)(ip6 + 1);
14312 			rack->r_ctl.fsb.udp = NULL;
14313 		}
14314 		tcpip_fillheaders(rack->rc_inp,
14315 				  tp->t_port,
14316 				  ip6, rack->r_ctl.fsb.th);
14317 		rack->r_ctl.fsb.hoplimit = in6_selecthlim(rack->rc_inp, NULL);
14318 	} else
14319 #endif				/* INET6 */
14320 #ifdef INET
14321 	{
14322 		rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct tcpiphdr);
14323 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
14324 		if (tp->t_port) {
14325 			rack->r_ctl.fsb.tcp_ip_hdr_len += sizeof(struct udphdr);
14326 			udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
14327 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
14328 			udp->uh_dport = tp->t_port;
14329 			rack->r_ctl.fsb.udp = udp;
14330 			rack->r_ctl.fsb.th = (struct tcphdr *)(udp + 1);
14331 		} else
14332 		{
14333 			rack->r_ctl.fsb.udp = NULL;
14334 			rack->r_ctl.fsb.th = (struct tcphdr *)(ip + 1);
14335 		}
14336 		tcpip_fillheaders(rack->rc_inp,
14337 				  tp->t_port,
14338 				  ip, rack->r_ctl.fsb.th);
14339 		rack->r_ctl.fsb.hoplimit = tptoinpcb(tp)->inp_ip_ttl;
14340 	}
14341 #endif
14342 	rack->r_ctl.fsb.recwin = lmin(lmax(sbspace(&tptosocket(tp)->so_rcv), 0),
14343 	    (long)TCP_MAXWIN << tp->rcv_scale);
14344 	rack->r_fsb_inited = 1;
14345 }
14346 
14347 static int
14348 rack_init_fsb(struct tcpcb *tp, struct tcp_rack *rack)
14349 {
14350 	/*
14351 	 * Allocate the larger of spaces V6 if available else just
14352 	 * V4 and include udphdr (overbook)
14353 	 */
14354 #ifdef INET6
14355 	rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + sizeof(struct udphdr);
14356 #else
14357 	rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct tcpiphdr) + sizeof(struct udphdr);
14358 #endif
14359 	rack->r_ctl.fsb.tcp_ip_hdr = malloc(rack->r_ctl.fsb.tcp_ip_hdr_len,
14360 					    M_TCPFSB, M_NOWAIT|M_ZERO);
14361 	if (rack->r_ctl.fsb.tcp_ip_hdr == NULL) {
14362 		return (ENOMEM);
14363 	}
14364 	rack->r_fsb_inited = 0;
14365 	return (0);
14366 }
14367 
14368 static void
14369 rack_log_hystart_event(struct tcp_rack *rack, uint32_t high_seq, uint8_t mod)
14370 {
14371 	/*
14372 	 * Types of logs (mod value)
14373 	 * 20 - Initial round setup
14374 	 * 21 - Rack declares a new round.
14375 	 */
14376 	struct tcpcb *tp;
14377 
14378 	tp = rack->rc_tp;
14379 	if (tcp_bblogging_on(tp)) {
14380 		union tcp_log_stackspecific log;
14381 		struct timeval tv;
14382 
14383 		memset(&log, 0, sizeof(log));
14384 		log.u_bbr.flex1 = rack->r_ctl.current_round;
14385 		log.u_bbr.flex2 = rack->r_ctl.roundends;
14386 		log.u_bbr.flex3 = high_seq;
14387 		log.u_bbr.flex4 = tp->snd_max;
14388 		log.u_bbr.flex8 = mod;
14389 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
14390 		log.u_bbr.cur_del_rate = rack->rc_tp->t_sndbytes;
14391 		log.u_bbr.delRate = rack->rc_tp->t_snd_rxt_bytes;
14392 		TCP_LOG_EVENTP(tp, NULL,
14393 		    &tptosocket(tp)->so_rcv,
14394 		    &tptosocket(tp)->so_snd,
14395 		    TCP_HYSTART, 0,
14396 		    0, &log, false, &tv);
14397 	}
14398 }
14399 
14400 static void
14401 rack_deferred_init(struct tcpcb *tp, struct tcp_rack *rack)
14402 {
14403 	rack->rack_deferred_inited = 1;
14404 	rack->r_ctl.roundends = tp->snd_max;
14405 	rack->r_ctl.rc_high_rwnd = tp->snd_wnd;
14406 	rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
14407 }
14408 
14409 static void
14410 rack_init_retransmit_value(struct tcp_rack *rack, int ctl)
14411 {
14412 	/* Retransmit bit controls.
14413 	 *
14414 	 * The setting of these values control one of
14415 	 * three settings you can have and dictate
14416 	 * how rack does retransmissions. Note this
14417 	 * is in *any* mode i.e. pacing on or off DGP
14418 	 * fixed rate pacing, or just bursting rack.
14419 	 *
14420 	 * 1 - Use full sized retransmits i.e. limit
14421 	 *     the size to whatever the pace_max_segments
14422 	 *     size is.
14423 	 *
14424 	 * 2 - Use pacer min granularity as a guide to
14425 	 *     the size combined with the current calculated
14426 	 *     goodput b/w measurement. So for example if
14427 	 *     the goodput is measured at 20Mbps we would
14428 	 *     calculate 8125 (pacer minimum 250usec in
14429 	 *     that b/w) and then round it up to the next
14430 	 *     MSS i.e. for 1448 mss 6 MSS or 8688 bytes.
14431 	 *
14432 	 * 0 - The rack default 1 MSS (anything not 0/1/2
14433 	 *     fall here too if we are setting via rack_init()).
14434 	 *
14435 	 */
14436 	if (ctl == 1) {
14437 		rack->full_size_rxt = 1;
14438 		rack->shape_rxt_to_pacing_min  = 0;
14439 	} else if (ctl == 2) {
14440 		rack->full_size_rxt = 0;
14441 		rack->shape_rxt_to_pacing_min  = 1;
14442 	} else {
14443 		rack->full_size_rxt = 0;
14444 		rack->shape_rxt_to_pacing_min  = 0;
14445 	}
14446 }
14447 
14448 static void
14449 rack_log_chg_info(struct tcpcb *tp, struct tcp_rack *rack, uint8_t mod,
14450 		  uint32_t flex1,
14451 		  uint32_t flex2,
14452 		  uint32_t flex3)
14453 {
14454 	if (tcp_bblogging_on(rack->rc_tp)) {
14455 		union tcp_log_stackspecific log;
14456 		struct timeval tv;
14457 
14458 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
14459 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
14460 		log.u_bbr.flex8 = mod;
14461 		log.u_bbr.flex1 = flex1;
14462 		log.u_bbr.flex2 = flex2;
14463 		log.u_bbr.flex3 = flex3;
14464 		tcp_log_event(tp, NULL, NULL, NULL, TCP_CHG_QUERY, 0,
14465 			       0, &log, false, NULL, __func__, __LINE__, &tv);
14466 	}
14467 }
14468 
14469 static int
14470 rack_chg_query(struct tcpcb *tp, struct tcp_query_resp *reqr)
14471 {
14472 	struct tcp_rack *rack;
14473 	struct rack_sendmap *rsm;
14474 	int i;
14475 
14476 
14477 	rack = (struct tcp_rack *)tp->t_fb_ptr;
14478 	switch (reqr->req) {
14479 	case TCP_QUERY_SENDMAP:
14480 		if ((reqr->req_param == tp->snd_max) ||
14481 		    (tp->snd_max == tp->snd_una)){
14482 			/* Unlikely */
14483 			return (0);
14484 		}
14485 		rsm = tqhash_find(rack->r_ctl.tqh, reqr->req_param);
14486 		if (rsm == NULL) {
14487 			/* Can't find that seq -- unlikely */
14488 			return (0);
14489 		}
14490 		reqr->sendmap_start = rsm->r_start;
14491 		reqr->sendmap_end = rsm->r_end;
14492 		reqr->sendmap_send_cnt = rsm->r_rtr_cnt;
14493 		reqr->sendmap_fas = rsm->r_fas;
14494 		if (reqr->sendmap_send_cnt > SNDMAP_NRTX)
14495 			reqr->sendmap_send_cnt = SNDMAP_NRTX;
14496 		for(i=0; i<reqr->sendmap_send_cnt; i++)
14497 			reqr->sendmap_time[i] = rsm->r_tim_lastsent[i];
14498 		reqr->sendmap_ack_arrival = rsm->r_ack_arrival;
14499 		reqr->sendmap_flags = rsm->r_flags & SNDMAP_MASK;
14500 		reqr->sendmap_r_rtr_bytes = rsm->r_rtr_bytes;
14501 		reqr->sendmap_dupacks = rsm->r_dupack;
14502 		rack_log_chg_info(tp, rack, 1,
14503 				  rsm->r_start,
14504 				  rsm->r_end,
14505 				  rsm->r_flags);
14506 		return(1);
14507 		break;
14508 	case TCP_QUERY_TIMERS_UP:
14509 		if (rack->r_ctl.rc_hpts_flags == 0) {
14510 			/* no timers up */
14511 			return (0);
14512 		}
14513 		reqr->timer_hpts_flags = rack->r_ctl.rc_hpts_flags;
14514 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
14515 			reqr->timer_pacing_to = rack->r_ctl.rc_last_output_to;
14516 		}
14517 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
14518 			reqr->timer_timer_exp = rack->r_ctl.rc_timer_exp;
14519 		}
14520 		rack_log_chg_info(tp, rack, 2,
14521 				  rack->r_ctl.rc_hpts_flags,
14522 				  rack->r_ctl.rc_last_output_to,
14523 				  rack->r_ctl.rc_timer_exp);
14524 		return (1);
14525 		break;
14526 	case TCP_QUERY_RACK_TIMES:
14527 		/* Reordering items */
14528 		reqr->rack_num_dsacks = rack->r_ctl.num_dsack;
14529 		reqr->rack_reorder_ts = rack->r_ctl.rc_reorder_ts;
14530 		/* Timerstamps and timers */
14531 		reqr->rack_rxt_last_time = rack->r_ctl.rc_tlp_rxt_last_time;
14532 		reqr->rack_min_rtt = rack->r_ctl.rc_rack_min_rtt;
14533 		reqr->rack_rtt = rack->rc_rack_rtt;
14534 		reqr->rack_tmit_time = rack->r_ctl.rc_rack_tmit_time;
14535 		reqr->rack_srtt_measured = rack->rc_srtt_measure_made;
14536 		/* PRR data */
14537 		reqr->rack_sacked = rack->r_ctl.rc_sacked;
14538 		reqr->rack_holes_rxt = rack->r_ctl.rc_holes_rxt;
14539 		reqr->rack_prr_delivered = rack->r_ctl.rc_prr_delivered;
14540 		reqr->rack_prr_recovery_fs = rack->r_ctl.rc_prr_recovery_fs;
14541 		reqr->rack_prr_sndcnt = rack->r_ctl.rc_prr_sndcnt;
14542 		reqr->rack_prr_out = rack->r_ctl.rc_prr_out;
14543 		/* TLP and persists info */
14544 		reqr->rack_tlp_out = rack->rc_tlp_in_progress;
14545 		reqr->rack_tlp_cnt_out = rack->r_ctl.rc_tlp_cnt_out;
14546 		if (rack->rc_in_persist) {
14547 			reqr->rack_time_went_idle = rack->r_ctl.rc_went_idle_time;
14548 			reqr->rack_in_persist = 1;
14549 		} else {
14550 			reqr->rack_time_went_idle = 0;
14551 			reqr->rack_in_persist = 0;
14552 		}
14553 		if (rack->r_wanted_output)
14554 			reqr->rack_wanted_output = 1;
14555 		else
14556 			reqr->rack_wanted_output = 0;
14557 		return (1);
14558 		break;
14559 	default:
14560 		return (-EINVAL);
14561 	}
14562 }
14563 
14564 static void
14565 rack_switch_failed(struct tcpcb *tp)
14566 {
14567 	/*
14568 	 * This method gets called if a stack switch was
14569 	 * attempted and it failed. We are left
14570 	 * but our hpts timers were stopped and we
14571 	 * need to validate time units and t_flags2.
14572 	 */
14573 	struct tcp_rack *rack;
14574 	struct timeval tv;
14575 	uint32_t cts;
14576 	uint32_t toval;
14577 	struct hpts_diag diag;
14578 
14579 	rack = (struct tcp_rack *)tp->t_fb_ptr;
14580 	tcp_change_time_units(tp, TCP_TMR_GRANULARITY_USEC);
14581 	if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
14582 		tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
14583 	else
14584 		tp->t_flags2 &= ~TF2_SUPPORTS_MBUFQ;
14585 	if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
14586 		tp->t_flags2 |= TF2_MBUF_ACKCMP;
14587 	if (tp->t_in_hpts > IHPTS_NONE) {
14588 		/* Strange */
14589 		return;
14590 	}
14591 	cts = tcp_get_usecs(&tv);
14592 	if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
14593 		if (TSTMP_GT(rack->r_ctl.rc_last_output_to, cts)) {
14594 			toval = rack->r_ctl.rc_last_output_to - cts;
14595 		} else {
14596 			/* one slot please */
14597 			toval = HPTS_TICKS_PER_SLOT;
14598 		}
14599 	} else if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
14600 		if (TSTMP_GT(rack->r_ctl.rc_timer_exp, cts)) {
14601 			toval = rack->r_ctl.rc_timer_exp - cts;
14602 		} else {
14603 			/* one slot please */
14604 			toval = HPTS_TICKS_PER_SLOT;
14605 		}
14606 	} else
14607 		toval = HPTS_TICKS_PER_SLOT;
14608 	(void)tcp_hpts_insert_diag(tp, HPTS_USEC_TO_SLOTS(toval),
14609 				   __LINE__, &diag);
14610 	rack_log_hpts_diag(rack, cts, &diag, &tv);
14611 }
14612 
14613 static int
14614 rack_init_outstanding(struct tcpcb *tp, struct tcp_rack *rack, uint32_t us_cts, void *ptr)
14615 {
14616 	struct rack_sendmap *rsm, *ersm;
14617 	int insret __diagused;
14618 	/*
14619 	 * When initing outstanding, we must be quite careful
14620 	 * to not refer to tp->t_fb_ptr. This has the old rack
14621 	 * pointer in it, not the "new" one (when we are doing
14622 	 * a stack switch).
14623 	 */
14624 
14625 
14626 	if (tp->t_fb->tfb_chg_query == NULL) {
14627 		/* Create a send map for the current outstanding data */
14628 
14629 		rsm = rack_alloc(rack);
14630 		if (rsm == NULL) {
14631 			uma_zfree(rack_pcb_zone, ptr);
14632 			return (ENOMEM);
14633 		}
14634 		rsm->r_no_rtt_allowed = 1;
14635 		rsm->r_tim_lastsent[0] = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
14636 		rsm->r_rtr_cnt = 1;
14637 		rsm->r_rtr_bytes = 0;
14638 		if (tp->t_flags & TF_SENTFIN)
14639 			rsm->r_flags |= RACK_HAS_FIN;
14640 		rsm->r_end = tp->snd_max;
14641 		if (tp->snd_una == tp->iss) {
14642 			/* The data space is one beyond snd_una */
14643 			rsm->r_flags |= RACK_HAS_SYN;
14644 			rsm->r_start = tp->iss;
14645 			rsm->r_end = rsm->r_start + (tp->snd_max - tp->snd_una);
14646 		} else
14647 			rsm->r_start = tp->snd_una;
14648 		rsm->r_dupack = 0;
14649 		if (rack->rc_inp->inp_socket->so_snd.sb_mb != NULL) {
14650 			rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd, 0, &rsm->soff);
14651 			if (rsm->m) {
14652 				rsm->orig_m_len = rsm->m->m_len;
14653 				rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
14654 			} else {
14655 				rsm->orig_m_len = 0;
14656 				rsm->orig_t_space = 0;
14657 			}
14658 		} else {
14659 			/*
14660 			 * This can happen if we have a stand-alone FIN or
14661 			 *  SYN.
14662 			 */
14663 			rsm->m = NULL;
14664 			rsm->orig_m_len = 0;
14665 			rsm->orig_t_space = 0;
14666 			rsm->soff = 0;
14667 		}
14668 #ifdef INVARIANTS
14669 		if ((insret = tqhash_insert(rack->r_ctl.tqh, rsm)) != 0) {
14670 			panic("Insert in rb tree fails ret:%d rack:%p rsm:%p",
14671 			      insret, rack, rsm);
14672 		}
14673 #else
14674 		(void)tqhash_insert(rack->r_ctl.tqh, rsm);
14675 #endif
14676 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
14677 		rsm->r_in_tmap = 1;
14678 	} else {
14679 		/* We have a query mechanism, lets use it */
14680 		struct tcp_query_resp qr;
14681 		int i;
14682 		tcp_seq at;
14683 
14684 		at = tp->snd_una;
14685 		while (at != tp->snd_max) {
14686 			memset(&qr, 0, sizeof(qr));
14687 			qr.req = TCP_QUERY_SENDMAP;
14688 			qr.req_param = at;
14689 			if ((*tp->t_fb->tfb_chg_query)(tp, &qr) == 0)
14690 				break;
14691 			/* Move forward */
14692 			at = qr.sendmap_end;
14693 			/* Now lets build the entry for this one */
14694 			rsm = rack_alloc(rack);
14695 			if (rsm == NULL) {
14696 				uma_zfree(rack_pcb_zone, ptr);
14697 				return (ENOMEM);
14698 			}
14699 			memset(rsm, 0, sizeof(struct rack_sendmap));
14700 			/* Now configure the rsm and insert it */
14701 			rsm->r_dupack = qr.sendmap_dupacks;
14702 			rsm->r_start = qr.sendmap_start;
14703 			rsm->r_end = qr.sendmap_end;
14704 			if (qr.sendmap_fas)
14705 				rsm->r_fas = qr.sendmap_end;
14706 			else
14707 				rsm->r_fas = rsm->r_start - tp->snd_una;
14708 			/*
14709 			 * We have carefully aligned the bits
14710 			 * so that all we have to do is copy over
14711 			 * the bits with the mask.
14712 			 */
14713 			rsm->r_flags = qr.sendmap_flags & SNDMAP_MASK;
14714 			rsm->r_rtr_bytes = qr.sendmap_r_rtr_bytes;
14715 			rsm->r_rtr_cnt = qr.sendmap_send_cnt;
14716 			rsm->r_ack_arrival = qr.sendmap_ack_arrival;
14717 			for (i=0 ; i<rsm->r_rtr_cnt; i++)
14718 				rsm->r_tim_lastsent[i]	= qr.sendmap_time[i];
14719 			rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd,
14720 					   (rsm->r_start - tp->snd_una), &rsm->soff);
14721 			if (rsm->m) {
14722 				rsm->orig_m_len = rsm->m->m_len;
14723 				rsm->orig_t_space = M_TRAILINGROOM(rsm->m);
14724 			} else {
14725 				rsm->orig_m_len = 0;
14726 				rsm->orig_t_space = 0;
14727 			}
14728 #ifdef INVARIANTS
14729 			if ((insret = tqhash_insert(rack->r_ctl.tqh, rsm)) != 0) {
14730 				panic("Insert in rb tree fails ret:%d rack:%p rsm:%p",
14731 				      insret, rack, rsm);
14732 			}
14733 #else
14734 			(void)tqhash_insert(rack->r_ctl.tqh, rsm);
14735 #endif
14736 			if ((rsm->r_flags & RACK_ACKED) == 0)  {
14737 				TAILQ_FOREACH(ersm, &rack->r_ctl.rc_tmap, r_tnext) {
14738 					if (ersm->r_tim_lastsent[(ersm->r_rtr_cnt-1)] >
14739 					    rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]) {
14740 						/*
14741 						 * If the existing ersm was sent at
14742 						 * a later time than the new one, then
14743 						 * the new one should appear ahead of this
14744 						 * ersm.
14745 						 */
14746 						rsm->r_in_tmap = 1;
14747 						TAILQ_INSERT_BEFORE(ersm, rsm, r_tnext);
14748 						break;
14749 					}
14750 				}
14751 				if (rsm->r_in_tmap == 0) {
14752 					/*
14753 					 * Not found so shove it on the tail.
14754 					 */
14755 					TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
14756 					rsm->r_in_tmap = 1;
14757 				}
14758  			} else {
14759 				if ((rack->r_ctl.rc_sacklast == NULL) ||
14760 				    (SEQ_GT(rsm->r_end, rack->r_ctl.rc_sacklast->r_end))) {
14761 					rack->r_ctl.rc_sacklast = rsm;
14762 				}
14763 			}
14764 			rack_log_chg_info(tp, rack, 3,
14765 					  rsm->r_start,
14766 					  rsm->r_end,
14767 					  rsm->r_flags);
14768 		}
14769 	}
14770 	return (0);
14771 }
14772 
14773 static void
14774 rack_translate_clamp_value(struct tcp_rack *rack, uint32_t optval)
14775 {
14776 	/*
14777 	 * P = percent bits
14778 	 * F = fill cw bit -- Toggle fillcw if this bit is set.
14779 	 * S = Segment bits
14780 	 * M = set max segment bit
14781 	 * U = Unclamined
14782 	 * C = If set to non-zero override the max number of clamps.
14783 	 * L = Bit to indicate if clamped gets lower.
14784 	 *
14785 	 * CCCC CCCCC UUUU UULF PPPP PPPP PPPP PPPP
14786 	 *
14787 	 * The lowest 3 nibbles is the perentage .1 - 6553.5%
14788 	 * where 10.1 = 101, max 6553.5
14789 	 * The upper 16 bits  holds some options.
14790 	 * The F bit will turn on fill-cw on if you are
14791 	 * not pacing, it will turn it off if dgp is on.
14792 	 * The L bit will change it so when clamped we get
14793 	 * the min(gp, lt-bw) for dgp.
14794 	 */
14795 	uint16_t per;
14796 
14797 	rack->r_ctl.saved_rxt_clamp_val = optval;
14798 	per = optval & 0x0000ffff;
14799 	rack->r_ctl.rxt_threshold = (uint64_t)(per & 0xffff);
14800 	if (optval > 0) {
14801 		uint16_t clamp_opt;
14802 
14803 		rack->excess_rxt_on = 1;
14804 		clamp_opt = ((optval & 0xffff0000) >> 16);
14805 		rack->r_ctl.clamp_options = clamp_opt & 0x00ff;
14806 		if (clamp_opt & 0xff00) {
14807 			/* A max clamps is also present */
14808 			rack->r_ctl.max_clamps = (clamp_opt >> 8);
14809 		} else {
14810 			/* No specified clamps means no limit */
14811 			rack->r_ctl.max_clamps = 0;
14812 		}
14813 		if (rack->r_ctl.clamp_options & 0x0002) {
14814 			rack->r_clamped_gets_lower  = 1;
14815 		} else {
14816 			rack->r_clamped_gets_lower  = 0;
14817 		}
14818 	} else {
14819 		/* Turn it off back to default */
14820 		rack->excess_rxt_on = 0;
14821 		rack->r_clamped_gets_lower  = 0;
14822 	}
14823 
14824 }
14825 
14826 
14827 static int32_t
14828 rack_init(struct tcpcb *tp, void **ptr)
14829 {
14830 	struct inpcb *inp = tptoinpcb(tp);
14831 	struct tcp_rack *rack = NULL;
14832 	uint32_t iwin, snt, us_cts;
14833 	int err, no_query;
14834 
14835 	/*
14836 	 * First are we the initial or are we a switched stack?
14837 	 * If we are initing via tcp_newtcppcb the ptr passed
14838 	 * will be tp->t_fb_ptr. If its a stack switch that
14839 	 * has a previous stack we can query it will be a local
14840 	 * var that will in the end be set into t_fb_ptr.
14841 	 */
14842 	if (ptr == &tp->t_fb_ptr)
14843 		no_query = 1;
14844 	else
14845 		no_query = 0;
14846 	*ptr = uma_zalloc(rack_pcb_zone, M_NOWAIT);
14847 	if (*ptr == NULL) {
14848 		/*
14849 		 * We need to allocate memory but cant. The INP and INP_INFO
14850 		 * locks and they are recursive (happens during setup. So a
14851 		 * scheme to drop the locks fails :(
14852 		 *
14853 		 */
14854 		return(ENOMEM);
14855 	}
14856 	memset(*ptr, 0, sizeof(struct tcp_rack));
14857 	rack = (struct tcp_rack *)*ptr;
14858 	rack->r_ctl.tqh = malloc(sizeof(struct tailq_hash), M_TCPFSB, M_NOWAIT);
14859 	if (rack->r_ctl.tqh == NULL) {
14860 		uma_zfree(rack_pcb_zone, rack);
14861 		return(ENOMEM);
14862 	}
14863 	tqhash_init(rack->r_ctl.tqh);
14864 	TAILQ_INIT(&rack->r_ctl.rc_free);
14865 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
14866 	rack->rc_tp = tp;
14867 	rack->rc_inp = inp;
14868 	/* Set the flag */
14869 	rack->r_is_v6 = (inp->inp_vflag & INP_IPV6) != 0;
14870 	/* Probably not needed but lets be sure */
14871 	rack_clear_rate_sample(rack);
14872 	/*
14873 	 * Save off the default values, socket options will poke
14874 	 * at these if pacing is not on or we have not yet
14875 	 * reached where pacing is on (gp_ready/fixed enabled).
14876 	 * When they get set into the CC module (when gp_ready
14877 	 * is enabled or we enable fixed) then we will set these
14878 	 * values into the CC and place in here the old values
14879 	 * so we have a restoral. Then we will set the flag
14880 	 * rc_pacing_cc_set. That way whenever we turn off pacing
14881 	 * or switch off this stack, we will know to go restore
14882 	 * the saved values.
14883 	 *
14884 	 * We specifically put into the beta the ecn value for pacing.
14885 	 */
14886 	rack->rc_new_rnd_needed = 1;
14887 	rack->r_ctl.rc_split_limit = V_tcp_map_split_limit;
14888 	rack->r_ctl.rc_saved_beta.beta = V_newreno_beta_ecn;
14889 	rack->r_ctl.rc_saved_beta.beta_ecn = V_newreno_beta_ecn;
14890 	/* We want abe like behavior as well */
14891 	rack->r_ctl.rc_saved_beta.newreno_flags |= CC_NEWRENO_BETA_ECN_ENABLED;
14892 	rack->r_ctl.rc_reorder_fade = rack_reorder_fade;
14893 	rack->rc_allow_data_af_clo = rack_ignore_data_after_close;
14894 	rack->r_ctl.rc_tlp_threshold = rack_tlp_thresh;
14895 	if (rack_rxt_clamp_thresh) {
14896 		rack_translate_clamp_value(rack, rack_rxt_clamp_thresh);
14897 		rack->excess_rxt_on = 1;
14898 	}
14899 	if (rack_uses_full_dgp_in_rec)
14900 		rack->r_ctl.full_dgp_in_rec = 1;
14901 	if (rack_fill_cw_state)
14902 		rack->rc_pace_to_cwnd = 1;
14903 	if (rack_pacing_min_seg)
14904 		rack->r_ctl.rc_user_set_min_segs = rack_pacing_min_seg;
14905 	if (use_rack_rr)
14906 		rack->use_rack_rr = 1;
14907 	if (rack_dnd_default) {
14908 		rack->rc_pace_dnd = 1;
14909 	}
14910 	if (V_tcp_delack_enabled)
14911 		tp->t_delayed_ack = 1;
14912 	else
14913 		tp->t_delayed_ack = 0;
14914 #ifdef TCP_ACCOUNTING
14915 	if (rack_tcp_accounting) {
14916 		tp->t_flags2 |= TF2_TCP_ACCOUNTING;
14917 	}
14918 #endif
14919 	rack->r_ctl.rack_per_upper_bound_ss = (uint8_t)rack_per_upper_bound_ss;
14920 	rack->r_ctl.rack_per_upper_bound_ca = (uint8_t)rack_per_upper_bound_ca;
14921 	if (rack_enable_shared_cwnd)
14922 		rack->rack_enable_scwnd = 1;
14923 	rack->r_ctl.pace_len_divisor = rack_default_pacing_divisor;
14924 	rack->rc_user_set_max_segs = rack_hptsi_segments;
14925 	rack->rc_force_max_seg = 0;
14926 	TAILQ_INIT(&rack->r_ctl.opt_list);
14927 	if (rack_hibeta_setting)
14928 		rack->rack_hibeta = 1;
14929 	rack->r_ctl.rc_reorder_shift = rack_reorder_thresh;
14930 	rack->r_ctl.rc_pkt_delay = rack_pkt_delay;
14931 	rack->r_ctl.rc_tlp_cwnd_reduce = rack_lower_cwnd_at_tlp;
14932 	rack->r_ctl.rc_lowest_us_rtt = 0xffffffff;
14933 	rack->r_ctl.rc_highest_us_rtt = 0;
14934 	rack->r_ctl.bw_rate_cap = rack_bw_rate_cap;
14935 	rack->r_ctl.timer_slop = TICKS_2_USEC(tcp_rexmit_slop);
14936 	if (rack_use_cmp_acks)
14937 		rack->r_use_cmp_ack = 1;
14938 	if (rack_disable_prr)
14939 		rack->rack_no_prr = 1;
14940 	if (rack_gp_no_rec_chg)
14941 		rack->rc_gp_no_rec_chg = 1;
14942 	if (rack_pace_every_seg && tcp_can_enable_pacing()) {
14943 		rack->rc_always_pace = 1;
14944 		if ((rack->gp_ready) && (rack->rc_always_pace && (rack->use_fixed_rate == 0)))
14945 			rack_set_cc_pacing(rack);
14946 	} else
14947 		rack->rc_always_pace = 0;
14948 	if (rack_enable_mqueue_for_nonpaced || rack->r_use_cmp_ack)
14949 		rack->r_mbuf_queue = 1;
14950 	else
14951 		rack->r_mbuf_queue = 0;
14952 	rack_set_pace_segments(tp, rack, __LINE__, NULL);
14953 	if (rack_limits_scwnd)
14954 		rack->r_limit_scw = 1;
14955 	else
14956 		rack->r_limit_scw = 0;
14957 	rack_init_retransmit_value(rack, rack_rxt_controls);
14958 	rack->rc_labc = V_tcp_abc_l_var;
14959 	rack->r_ctl.rc_rate_sample_method = rack_rate_sample_method;
14960 	rack->rack_tlp_threshold_use = rack_tlp_threshold_use;
14961 	rack->r_ctl.rc_prr_sendalot = rack_send_a_lot_in_prr;
14962 	rack->r_ctl.rc_min_to = rack_min_to;
14963 	microuptime(&rack->r_ctl.act_rcv_time);
14964 	rack->r_ctl.rc_last_time_decay = rack->r_ctl.act_rcv_time;
14965 	rack->rc_init_win = rack_default_init_window;
14966 	rack->r_ctl.rack_per_of_gp_ss = rack_per_of_gp_ss;
14967 	if (rack_hw_up_only)
14968 		rack->r_up_only = 1;
14969 	if (rack_do_dyn_mul) {
14970 		/* When dynamic adjustment is on CA needs to start at 100% */
14971 		rack->rc_gp_dyn_mul = 1;
14972 		if (rack_do_dyn_mul >= 100)
14973 			rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
14974 	} else
14975 		rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
14976 	rack->r_ctl.rack_per_of_gp_rec = rack_per_of_gp_rec;
14977 	rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
14978 	rack->r_ctl.rc_tlp_rxt_last_time = tcp_tv_to_mssectick(&rack->r_ctl.act_rcv_time);
14979 	setup_time_filter_small(&rack->r_ctl.rc_gp_min_rtt, FILTER_TYPE_MIN,
14980 				rack_probertt_filter_life);
14981 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
14982 	rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
14983 	rack->r_ctl.rc_time_of_last_probertt = us_cts;
14984 	rack->r_ctl.challenge_ack_ts = tcp_ts_getticks();
14985 	rack->r_ctl.rc_time_probertt_starts = 0;
14986 	if (rack_dsack_std_based & 0x1) {
14987 		/* Basically this means all rack timers are at least (srtt + 1/4 srtt) */
14988 		rack->rc_rack_tmr_std_based = 1;
14989 	}
14990 	if (rack_dsack_std_based & 0x2) {
14991 		/* Basically this means  rack timers are extended based on dsack by up to (2 * srtt) */
14992 		rack->rc_rack_use_dsack = 1;
14993 	}
14994 	/* We require at least one measurement, even if the sysctl is 0 */
14995 	if (rack_req_measurements)
14996 		rack->r_ctl.req_measurements = rack_req_measurements;
14997 	else
14998 		rack->r_ctl.req_measurements = 1;
14999 	if (rack_enable_hw_pacing)
15000 		rack->rack_hdw_pace_ena = 1;
15001 	if (rack_hw_rate_caps)
15002 		rack->r_rack_hw_rate_caps = 1;
15003 #ifdef TCP_SAD_DETECTION
15004 	rack->do_detection = 1;
15005 #else
15006 	rack->do_detection = 0;
15007 #endif
15008 	if (rack_non_rxt_use_cr)
15009 		rack->rack_rec_nonrxt_use_cr = 1;
15010 	/* Lets setup the fsb block */
15011 	err = rack_init_fsb(tp, rack);
15012 	if (err) {
15013 		uma_zfree(rack_pcb_zone, *ptr);
15014 		*ptr = NULL;
15015 		return (err);
15016 	}
15017 	if (rack_do_hystart) {
15018 		tp->t_ccv.flags |= CCF_HYSTART_ALLOWED;
15019 		if (rack_do_hystart > 1)
15020 			tp->t_ccv.flags |= CCF_HYSTART_CAN_SH_CWND;
15021 		if (rack_do_hystart > 2)
15022 			tp->t_ccv.flags |= CCF_HYSTART_CONS_SSTH;
15023 	}
15024 	/* Log what we will do with queries */
15025 	rack_log_chg_info(tp, rack, 7,
15026 			  no_query, 0, 0);
15027 	if (rack_def_profile)
15028 		rack_set_profile(rack, rack_def_profile);
15029 	/* Cancel the GP measurement in progress */
15030 	tp->t_flags &= ~TF_GPUTINPROG;
15031 	if ((tp->t_state != TCPS_CLOSED) &&
15032 	    (tp->t_state != TCPS_TIME_WAIT)) {
15033 		/*
15034 		 * We are already open, we may
15035 		 * need to adjust a few things.
15036 		 */
15037 		if (SEQ_GT(tp->snd_max, tp->iss))
15038 			snt = tp->snd_max - tp->iss;
15039 		else
15040 			snt = 0;
15041 		iwin = rc_init_window(rack);
15042 		if ((snt < iwin) &&
15043 		    (no_query == 1)) {
15044 			/* We are not past the initial window
15045 			 * on the first init (i.e. a stack switch
15046 			 * has not yet occured) so we need to make
15047 			 * sure cwnd and ssthresh is correct.
15048 			 */
15049 			if (tp->snd_cwnd < iwin)
15050 				tp->snd_cwnd = iwin;
15051 			/*
15052 			 * If we are within the initial window
15053 			 * we want ssthresh to be unlimited. Setting
15054 			 * it to the rwnd (which the default stack does
15055 			 * and older racks) is not really a good idea
15056 			 * since we want to be in SS and grow both the
15057 			 * cwnd and the rwnd (via dynamic rwnd growth). If
15058 			 * we set it to the rwnd then as the peer grows its
15059 			 * rwnd we will be stuck in CA and never hit SS.
15060 			 *
15061 			 * Its far better to raise it up high (this takes the
15062 			 * risk that there as been a loss already, probably
15063 			 * we should have an indicator in all stacks of loss
15064 			 * but we don't), but considering the normal use this
15065 			 * is a risk worth taking. The consequences of not
15066 			 * hitting SS are far worse than going one more time
15067 			 * into it early on (before we have sent even a IW).
15068 			 * It is highly unlikely that we will have had a loss
15069 			 * before getting the IW out.
15070 			 */
15071 			tp->snd_ssthresh = 0xffffffff;
15072 		}
15073 		/*
15074 		 * Any init based on sequence numbers
15075 		 * should be done in the deferred init path
15076 		 * since we can be CLOSED and not have them
15077 		 * inited when rack_init() is called. We
15078 		 * are not closed so lets call it.
15079 		 */
15080 		rack_deferred_init(tp, rack);
15081 	}
15082 	if ((tp->t_state != TCPS_CLOSED) &&
15083 	    (tp->t_state != TCPS_TIME_WAIT) &&
15084 	    (no_query == 0) &&
15085 	    (tp->snd_una != tp->snd_max))  {
15086 		err = rack_init_outstanding(tp, rack, us_cts, *ptr);
15087 		if (err) {
15088 			*ptr = NULL;
15089 			return(err);
15090 		}
15091 	}
15092 	rack_stop_all_timers(tp, rack);
15093 	/* Setup all the t_flags2 */
15094 	if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
15095 		tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
15096 	else
15097 		tp->t_flags2 &= ~TF2_SUPPORTS_MBUFQ;
15098 	if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
15099 		tp->t_flags2 |= TF2_MBUF_ACKCMP;
15100 	/*
15101 	 * Timers in Rack are kept in microseconds so lets
15102 	 * convert any initial incoming variables
15103 	 * from ticks into usecs. Note that we
15104 	 * also change the values of t_srtt and t_rttvar, if
15105 	 * they are non-zero. They are kept with a 5
15106 	 * bit decimal so we have to carefully convert
15107 	 * these to get the full precision.
15108 	 */
15109 	rack_convert_rtts(tp);
15110 	rack_log_hystart_event(rack, rack->r_ctl.roundends, 20);
15111 	if ((tptoinpcb(tp)->inp_flags & INP_DROPPED) == 0) {
15112 		/* We do not start any timers on DROPPED connections */
15113 		if (tp->t_fb->tfb_chg_query == NULL) {
15114 			rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
15115 		} else {
15116 			struct tcp_query_resp qr;
15117 			int ret;
15118 
15119 			memset(&qr, 0, sizeof(qr));
15120 
15121 			/* Get the misc time stamps and such for rack */
15122 			qr.req = TCP_QUERY_RACK_TIMES;
15123 			ret = (*tp->t_fb->tfb_chg_query)(tp, &qr);
15124 			if (ret == 1) {
15125 				rack->r_ctl.rc_reorder_ts = qr.rack_reorder_ts;
15126 				rack->r_ctl.num_dsack  = qr.rack_num_dsacks;
15127 				rack->r_ctl.rc_tlp_rxt_last_time = qr.rack_rxt_last_time;
15128 				rack->r_ctl.rc_rack_min_rtt = qr.rack_min_rtt;
15129 				rack->rc_rack_rtt = qr.rack_rtt;
15130 				rack->r_ctl.rc_rack_tmit_time = qr.rack_tmit_time;
15131 				rack->r_ctl.rc_sacked = qr.rack_sacked;
15132 				rack->r_ctl.rc_holes_rxt = qr.rack_holes_rxt;
15133 				rack->r_ctl.rc_prr_delivered = qr.rack_prr_delivered;
15134 				rack->r_ctl.rc_prr_recovery_fs = qr.rack_prr_recovery_fs;
15135 				rack->r_ctl.rc_prr_sndcnt = qr.rack_prr_sndcnt;
15136 				rack->r_ctl.rc_prr_out = qr.rack_prr_out;
15137 				if (qr.rack_tlp_out) {
15138 					rack->rc_tlp_in_progress = 1;
15139 					rack->r_ctl.rc_tlp_cnt_out = qr.rack_tlp_cnt_out;
15140 				} else {
15141 					rack->rc_tlp_in_progress = 0;
15142 					rack->r_ctl.rc_tlp_cnt_out = 0;
15143 				}
15144 				if (qr.rack_srtt_measured)
15145 					rack->rc_srtt_measure_made = 1;
15146 				if (qr.rack_in_persist == 1) {
15147 					rack->r_ctl.rc_went_idle_time = qr.rack_time_went_idle;
15148 #ifdef NETFLIX_SHARED_CWND
15149 					if (rack->r_ctl.rc_scw) {
15150 						tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
15151 						rack->rack_scwnd_is_idle = 1;
15152 					}
15153 #endif
15154 					rack->r_ctl.persist_lost_ends = 0;
15155 					rack->probe_not_answered = 0;
15156 					rack->forced_ack = 0;
15157 					tp->t_rxtshift = 0;
15158 					rack->rc_in_persist = 1;
15159 					RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
15160 							   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
15161 				}
15162 				if (qr.rack_wanted_output)
15163 					rack->r_wanted_output = 1;
15164 				rack_log_chg_info(tp, rack, 6,
15165 						  qr.rack_min_rtt,
15166 						  qr.rack_rtt,
15167 						  qr.rack_reorder_ts);
15168 			}
15169 			/* Get the old stack timers */
15170 			qr.req_param = 0;
15171 			qr.req = TCP_QUERY_TIMERS_UP;
15172 			ret = (*tp->t_fb->tfb_chg_query)(tp, &qr);
15173 			if (ret) {
15174 				/*
15175 				 * non-zero return means we have a timer('s)
15176 				 * to start. Zero means no timer (no keepalive
15177 				 * I suppose).
15178 				 */
15179 				uint32_t tov = 0;
15180 
15181 				rack->r_ctl.rc_hpts_flags = qr.timer_hpts_flags;
15182 				if (qr.timer_hpts_flags & PACE_PKT_OUTPUT) {
15183 					rack->r_ctl.rc_last_output_to = qr.timer_pacing_to;
15184 					if (TSTMP_GT(qr.timer_pacing_to, us_cts))
15185 						tov = qr.timer_pacing_to - us_cts;
15186 					else
15187 						tov = HPTS_TICKS_PER_SLOT;
15188 				}
15189 				if (qr.timer_hpts_flags & PACE_TMR_MASK) {
15190 					rack->r_ctl.rc_timer_exp = qr.timer_timer_exp;
15191 					if (tov == 0) {
15192 						if (TSTMP_GT(qr.timer_timer_exp, us_cts))
15193 							tov = qr.timer_timer_exp - us_cts;
15194 						else
15195 							tov = HPTS_TICKS_PER_SLOT;
15196 					}
15197 				}
15198 				rack_log_chg_info(tp, rack, 4,
15199 						  rack->r_ctl.rc_hpts_flags,
15200 						  rack->r_ctl.rc_last_output_to,
15201 						  rack->r_ctl.rc_timer_exp);
15202 				if (tov) {
15203 					struct hpts_diag diag;
15204 
15205 					(void)tcp_hpts_insert_diag(tp, HPTS_USEC_TO_SLOTS(tov),
15206 								   __LINE__, &diag);
15207 					rack_log_hpts_diag(rack, us_cts, &diag, &rack->r_ctl.act_rcv_time);
15208 				}
15209 			}
15210 		}
15211 		rack_log_rtt_shrinks(rack,  us_cts,  tp->t_rxtcur,
15212 				     __LINE__, RACK_RTTS_INIT);
15213 	}
15214 	return (0);
15215 }
15216 
15217 static int
15218 rack_handoff_ok(struct tcpcb *tp)
15219 {
15220 	if ((tp->t_state == TCPS_CLOSED) ||
15221 	    (tp->t_state == TCPS_LISTEN)) {
15222 		/* Sure no problem though it may not stick */
15223 		return (0);
15224 	}
15225 	if ((tp->t_state == TCPS_SYN_SENT) ||
15226 	    (tp->t_state == TCPS_SYN_RECEIVED)) {
15227 		/*
15228 		 * We really don't know if you support sack,
15229 		 * you have to get to ESTAB or beyond to tell.
15230 		 */
15231 		return (EAGAIN);
15232 	}
15233 	if ((tp->t_flags & TF_SENTFIN) && ((tp->snd_max - tp->snd_una) > 1)) {
15234 		/*
15235 		 * Rack will only send a FIN after all data is acknowledged.
15236 		 * So in this case we have more data outstanding. We can't
15237 		 * switch stacks until either all data and only the FIN
15238 		 * is left (in which case rack_init() now knows how
15239 		 * to deal with that) <or> all is acknowledged and we
15240 		 * are only left with incoming data, though why you
15241 		 * would want to switch to rack after all data is acknowledged
15242 		 * I have no idea (rrs)!
15243 		 */
15244 		return (EAGAIN);
15245 	}
15246 	if ((tp->t_flags & TF_SACK_PERMIT) || rack_sack_not_required){
15247 		return (0);
15248 	}
15249 	/*
15250 	 * If we reach here we don't do SACK on this connection so we can
15251 	 * never do rack.
15252 	 */
15253 	return (EINVAL);
15254 }
15255 
15256 static void
15257 rack_fini(struct tcpcb *tp, int32_t tcb_is_purged)
15258 {
15259 
15260 	if (tp->t_fb_ptr) {
15261 		uint32_t cnt_free = 0;
15262 		struct tcp_rack *rack;
15263 		struct rack_sendmap *rsm;
15264 
15265 		tcp_handle_orphaned_packets(tp);
15266 		tp->t_flags &= ~TF_FORCEDATA;
15267 		rack = (struct tcp_rack *)tp->t_fb_ptr;
15268 		rack_log_pacing_delay_calc(rack,
15269 					   0,
15270 					   0,
15271 					   0,
15272 					   rack_get_gp_est(rack), /* delRate */
15273 					   rack_get_lt_bw(rack), /* rttProp */
15274 					   20, __LINE__, NULL, 0);
15275 #ifdef NETFLIX_SHARED_CWND
15276 		if (rack->r_ctl.rc_scw) {
15277 			uint32_t limit;
15278 
15279 			if (rack->r_limit_scw)
15280 				limit = max(1, rack->r_ctl.rc_lowest_us_rtt);
15281 			else
15282 				limit = 0;
15283 			tcp_shared_cwnd_free_full(tp, rack->r_ctl.rc_scw,
15284 						  rack->r_ctl.rc_scw_index,
15285 						  limit);
15286 			rack->r_ctl.rc_scw = NULL;
15287 		}
15288 #endif
15289 		if (rack->r_ctl.fsb.tcp_ip_hdr) {
15290 			free(rack->r_ctl.fsb.tcp_ip_hdr, M_TCPFSB);
15291 			rack->r_ctl.fsb.tcp_ip_hdr = NULL;
15292 			rack->r_ctl.fsb.th = NULL;
15293 		}
15294 		if (rack->rc_always_pace) {
15295 			tcp_decrement_paced_conn();
15296 			rack_undo_cc_pacing(rack);
15297 			rack->rc_always_pace = 0;
15298 		}
15299 		/* Clean up any options if they were not applied */
15300 		while (!TAILQ_EMPTY(&rack->r_ctl.opt_list)) {
15301 			struct deferred_opt_list *dol;
15302 
15303 			dol = TAILQ_FIRST(&rack->r_ctl.opt_list);
15304 			TAILQ_REMOVE(&rack->r_ctl.opt_list, dol, next);
15305 			free(dol, M_TCPDO);
15306 		}
15307 		/* rack does not use force data but other stacks may clear it */
15308 		if (rack->r_ctl.crte != NULL) {
15309 			tcp_rel_pacing_rate(rack->r_ctl.crte, tp);
15310 			rack->rack_hdrw_pacing = 0;
15311 			rack->r_ctl.crte = NULL;
15312 		}
15313 #ifdef TCP_BLACKBOX
15314 		tcp_log_flowend(tp);
15315 #endif
15316 		/*
15317 		 * Lets take a different approach to purging just
15318 		 * get each one and free it like a cum-ack would and
15319 		 * not use a foreach loop.
15320 		 */
15321 		rsm = tqhash_min(rack->r_ctl.tqh);
15322 		while (rsm) {
15323 			tqhash_remove(rack->r_ctl.tqh, rsm, REMOVE_TYPE_CUMACK);
15324 			rack->r_ctl.rc_num_maps_alloced--;
15325 			uma_zfree(rack_zone, rsm);
15326 			rsm = tqhash_min(rack->r_ctl.tqh);
15327 		}
15328 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
15329 		while (rsm) {
15330 			TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
15331 			rack->r_ctl.rc_num_maps_alloced--;
15332 			rack->rc_free_cnt--;
15333 			cnt_free++;
15334 			uma_zfree(rack_zone, rsm);
15335 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
15336 		}
15337 		if ((rack->r_ctl.rc_num_maps_alloced > 0) &&
15338 		    (tcp_bblogging_on(tp))) {
15339 			union tcp_log_stackspecific log;
15340 			struct timeval tv;
15341 
15342 			memset(&log.u_bbr, 0, sizeof(log.u_bbr));
15343 			log.u_bbr.flex8 = 10;
15344 			log.u_bbr.flex1 = rack->r_ctl.rc_num_maps_alloced;
15345 			log.u_bbr.flex2 = rack->rc_free_cnt;
15346 			log.u_bbr.flex3 = cnt_free;
15347 			log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
15348 			rsm = tqhash_min(rack->r_ctl.tqh);
15349 			log.u_bbr.delRate = (uint64_t)rsm;
15350 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
15351 			log.u_bbr.cur_del_rate = (uint64_t)rsm;
15352 			log.u_bbr.timeStamp = tcp_get_usecs(&tv);
15353 			log.u_bbr.pkt_epoch = __LINE__;
15354 			(void)tcp_log_event(tp, NULL, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
15355 					     0, &log, false, NULL, NULL, 0, &tv);
15356 		}
15357 		KASSERT((rack->r_ctl.rc_num_maps_alloced == 0),
15358 			("rack:%p num_aloc:%u after freeing all?",
15359 			 rack,
15360 			 rack->r_ctl.rc_num_maps_alloced));
15361 		rack->rc_free_cnt = 0;
15362 		free(rack->r_ctl.tqh, M_TCPFSB);
15363 		rack->r_ctl.tqh = NULL;
15364 		uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
15365 		tp->t_fb_ptr = NULL;
15366 	}
15367 	/* Make sure snd_nxt is correctly set */
15368 	tp->snd_nxt = tp->snd_max;
15369 }
15370 
15371 static void
15372 rack_set_state(struct tcpcb *tp, struct tcp_rack *rack)
15373 {
15374 	if ((rack->r_state == TCPS_CLOSED) && (tp->t_state != TCPS_CLOSED)) {
15375 		rack->r_is_v6 = (tptoinpcb(tp)->inp_vflag & INP_IPV6) != 0;
15376 	}
15377 	switch (tp->t_state) {
15378 	case TCPS_SYN_SENT:
15379 		rack->r_state = TCPS_SYN_SENT;
15380 		rack->r_substate = rack_do_syn_sent;
15381 		break;
15382 	case TCPS_SYN_RECEIVED:
15383 		rack->r_state = TCPS_SYN_RECEIVED;
15384 		rack->r_substate = rack_do_syn_recv;
15385 		break;
15386 	case TCPS_ESTABLISHED:
15387 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
15388 		rack->r_state = TCPS_ESTABLISHED;
15389 		rack->r_substate = rack_do_established;
15390 		break;
15391 	case TCPS_CLOSE_WAIT:
15392 		rack->r_state = TCPS_CLOSE_WAIT;
15393 		rack->r_substate = rack_do_close_wait;
15394 		break;
15395 	case TCPS_FIN_WAIT_1:
15396 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
15397 		rack->r_state = TCPS_FIN_WAIT_1;
15398 		rack->r_substate = rack_do_fin_wait_1;
15399 		break;
15400 	case TCPS_CLOSING:
15401 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
15402 		rack->r_state = TCPS_CLOSING;
15403 		rack->r_substate = rack_do_closing;
15404 		break;
15405 	case TCPS_LAST_ACK:
15406 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
15407 		rack->r_state = TCPS_LAST_ACK;
15408 		rack->r_substate = rack_do_lastack;
15409 		break;
15410 	case TCPS_FIN_WAIT_2:
15411 		rack->r_state = TCPS_FIN_WAIT_2;
15412 		rack->r_substate = rack_do_fin_wait_2;
15413 		break;
15414 	case TCPS_LISTEN:
15415 	case TCPS_CLOSED:
15416 	case TCPS_TIME_WAIT:
15417 	default:
15418 		break;
15419 	};
15420 	if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
15421 		rack->rc_tp->t_flags2 |= TF2_MBUF_ACKCMP;
15422 
15423 }
15424 
15425 static void
15426 rack_timer_audit(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb)
15427 {
15428 	/*
15429 	 * We received an ack, and then did not
15430 	 * call send or were bounced out due to the
15431 	 * hpts was running. Now a timer is up as well, is
15432 	 * it the right timer?
15433 	 */
15434 	struct rack_sendmap *rsm;
15435 	int tmr_up;
15436 
15437 	tmr_up = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
15438 	if (rack->rc_in_persist && (tmr_up == PACE_TMR_PERSIT))
15439 		return;
15440 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
15441 	if (((rsm == NULL) || (tp->t_state < TCPS_ESTABLISHED)) &&
15442 	    (tmr_up == PACE_TMR_RXT)) {
15443 		/* Should be an RXT */
15444 		return;
15445 	}
15446 	if (rsm == NULL) {
15447 		/* Nothing outstanding? */
15448 		if (tp->t_flags & TF_DELACK) {
15449 			if (tmr_up == PACE_TMR_DELACK)
15450 				/* We are supposed to have delayed ack up and we do */
15451 				return;
15452 		} else if (sbavail(&tptosocket(tp)->so_snd) && (tmr_up == PACE_TMR_RXT)) {
15453 			/*
15454 			 * if we hit enobufs then we would expect the possibility
15455 			 * of nothing outstanding and the RXT up (and the hptsi timer).
15456 			 */
15457 			return;
15458 		} else if (((V_tcp_always_keepalive ||
15459 			     rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
15460 			    (tp->t_state <= TCPS_CLOSING)) &&
15461 			   (tmr_up == PACE_TMR_KEEP) &&
15462 			   (tp->snd_max == tp->snd_una)) {
15463 			/* We should have keep alive up and we do */
15464 			return;
15465 		}
15466 	}
15467 	if (SEQ_GT(tp->snd_max, tp->snd_una) &&
15468 		   ((tmr_up == PACE_TMR_TLP) ||
15469 		    (tmr_up == PACE_TMR_RACK) ||
15470 		    (tmr_up == PACE_TMR_RXT))) {
15471 		/*
15472 		 * Either a Rack, TLP or RXT is fine if  we
15473 		 * have outstanding data.
15474 		 */
15475 		return;
15476 	} else if (tmr_up == PACE_TMR_DELACK) {
15477 		/*
15478 		 * If the delayed ack was going to go off
15479 		 * before the rtx/tlp/rack timer were going to
15480 		 * expire, then that would be the timer in control.
15481 		 * Note we don't check the time here trusting the
15482 		 * code is correct.
15483 		 */
15484 		return;
15485 	}
15486 	/*
15487 	 * Ok the timer originally started is not what we want now.
15488 	 * We will force the hpts to be stopped if any, and restart
15489 	 * with the slot set to what was in the saved slot.
15490 	 */
15491 	if (tcp_in_hpts(rack->rc_tp)) {
15492 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
15493 			uint32_t us_cts;
15494 
15495 			us_cts = tcp_get_usecs(NULL);
15496 			if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
15497 				rack->r_early = 1;
15498 				rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
15499 			}
15500 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
15501 		}
15502 		tcp_hpts_remove(rack->rc_tp);
15503 	}
15504 	rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
15505 	rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
15506 }
15507 
15508 
15509 static void
15510 rack_do_win_updates(struct tcpcb *tp, struct tcp_rack *rack, uint32_t tiwin, uint32_t seq, uint32_t ack, uint32_t cts)
15511 {
15512 	if ((SEQ_LT(tp->snd_wl1, seq) ||
15513 	    (tp->snd_wl1 == seq && (SEQ_LT(tp->snd_wl2, ack) ||
15514 	    (tp->snd_wl2 == ack && tiwin > tp->snd_wnd))))) {
15515 		/* keep track of pure window updates */
15516 		if ((tp->snd_wl2 == ack) && (tiwin > tp->snd_wnd))
15517 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
15518 		tp->snd_wnd = tiwin;
15519 		rack_validate_fo_sendwin_up(tp, rack);
15520 		tp->snd_wl1 = seq;
15521 		tp->snd_wl2 = ack;
15522 		if (tp->snd_wnd > tp->max_sndwnd)
15523 			tp->max_sndwnd = tp->snd_wnd;
15524 	    rack->r_wanted_output = 1;
15525 	} else if ((tp->snd_wl2 == ack) && (tiwin < tp->snd_wnd)) {
15526 		tp->snd_wnd = tiwin;
15527 		rack_validate_fo_sendwin_up(tp, rack);
15528 		tp->snd_wl1 = seq;
15529 		tp->snd_wl2 = ack;
15530 	} else {
15531 		/* Not a valid win update */
15532 		return;
15533 	}
15534 	if (tp->snd_wnd > tp->max_sndwnd)
15535 		tp->max_sndwnd = tp->snd_wnd;
15536 	/* Do we exit persists? */
15537 	if ((rack->rc_in_persist != 0) &&
15538 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
15539 				rack->r_ctl.rc_pace_min_segs))) {
15540 		rack_exit_persist(tp, rack, cts);
15541 	}
15542 	/* Do we enter persists? */
15543 	if ((rack->rc_in_persist == 0) &&
15544 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
15545 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
15546 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
15547 	    sbavail(&tptosocket(tp)->so_snd) &&
15548 	    (sbavail(&tptosocket(tp)->so_snd) > tp->snd_wnd)) {
15549 		/*
15550 		 * Here the rwnd is less than
15551 		 * the pacing size, we are established,
15552 		 * nothing is outstanding, and there is
15553 		 * data to send. Enter persists.
15554 		 */
15555 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime, ack);
15556 	}
15557 }
15558 
15559 static void
15560 rack_log_input_packet(struct tcpcb *tp, struct tcp_rack *rack, struct tcp_ackent *ae, int ackval, uint32_t high_seq)
15561 {
15562 
15563 	if (tcp_bblogging_on(rack->rc_tp)) {
15564 		struct inpcb *inp = tptoinpcb(tp);
15565 		union tcp_log_stackspecific log;
15566 		struct timeval ltv;
15567 		char tcp_hdr_buf[60];
15568 		struct tcphdr *th;
15569 		struct timespec ts;
15570 		uint32_t orig_snd_una;
15571 		uint8_t xx = 0;
15572 
15573 #ifdef TCP_REQUEST_TRK
15574 		struct http_sendfile_track *http_req;
15575 
15576 		if (SEQ_GT(ae->ack, tp->snd_una)) {
15577 			http_req = tcp_http_find_req_for_seq(tp, (ae->ack-1));
15578 		} else {
15579 			http_req = tcp_http_find_req_for_seq(tp, ae->ack);
15580 		}
15581 #endif
15582 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
15583 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
15584 		if (rack->rack_no_prr == 0)
15585 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
15586 		else
15587 			log.u_bbr.flex1 = 0;
15588 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
15589 		log.u_bbr.use_lt_bw <<= 1;
15590 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
15591 		log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
15592 		log.u_bbr.bbr_state = rack->rc_free_cnt;
15593 		log.u_bbr.inflight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
15594 		log.u_bbr.pkts_out = tp->t_maxseg;
15595 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
15596 		log.u_bbr.flex7 = 1;
15597 		log.u_bbr.lost = ae->flags;
15598 		log.u_bbr.cwnd_gain = ackval;
15599 		log.u_bbr.pacing_gain = 0x2;
15600 		if (ae->flags & TSTMP_HDWR) {
15601 			/* Record the hardware timestamp if present */
15602 			log.u_bbr.flex3 = M_TSTMP;
15603 			ts.tv_sec = ae->timestamp / 1000000000;
15604 			ts.tv_nsec = ae->timestamp % 1000000000;
15605 			ltv.tv_sec = ts.tv_sec;
15606 			ltv.tv_usec = ts.tv_nsec / 1000;
15607 			log.u_bbr.lt_epoch = tcp_tv_to_usectick(&ltv);
15608 		} else if (ae->flags & TSTMP_LRO) {
15609 			/* Record the LRO the arrival timestamp */
15610 			log.u_bbr.flex3 = M_TSTMP_LRO;
15611 			ts.tv_sec = ae->timestamp / 1000000000;
15612 			ts.tv_nsec = ae->timestamp % 1000000000;
15613 			ltv.tv_sec = ts.tv_sec;
15614 			ltv.tv_usec = ts.tv_nsec / 1000;
15615 			log.u_bbr.flex5 = tcp_tv_to_usectick(&ltv);
15616 		}
15617 		log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
15618 		/* Log the rcv time */
15619 		log.u_bbr.delRate = ae->timestamp;
15620 #ifdef TCP_REQUEST_TRK
15621 		log.u_bbr.applimited = tp->t_http_closed;
15622 		log.u_bbr.applimited <<= 8;
15623 		log.u_bbr.applimited |= tp->t_http_open;
15624 		log.u_bbr.applimited <<= 8;
15625 		log.u_bbr.applimited |= tp->t_http_req;
15626 		if (http_req) {
15627 			/* Copy out any client req info */
15628 			/* seconds */
15629 			log.u_bbr.pkt_epoch = (http_req->localtime / HPTS_USEC_IN_SEC);
15630 			/* useconds */
15631 			log.u_bbr.delivered = (http_req->localtime % HPTS_USEC_IN_SEC);
15632 			log.u_bbr.rttProp = http_req->timestamp;
15633 			log.u_bbr.cur_del_rate = http_req->start;
15634 			if (http_req->flags & TCP_HTTP_TRACK_FLG_OPEN) {
15635 				log.u_bbr.flex8 |= 1;
15636 			} else {
15637 				log.u_bbr.flex8 |= 2;
15638 				log.u_bbr.bw_inuse = http_req->end;
15639 			}
15640 			log.u_bbr.flex6 = http_req->start_seq;
15641 			if (http_req->flags & TCP_HTTP_TRACK_FLG_COMP) {
15642 				log.u_bbr.flex8 |= 4;
15643 				log.u_bbr.epoch = http_req->end_seq;
15644 			}
15645 		}
15646 #endif
15647 		memset(tcp_hdr_buf, 0, sizeof(tcp_hdr_buf));
15648 		th = (struct tcphdr *)tcp_hdr_buf;
15649 		th->th_seq = ae->seq;
15650 		th->th_ack = ae->ack;
15651 		th->th_win = ae->win;
15652 		/* Now fill in the ports */
15653 		th->th_sport = inp->inp_fport;
15654 		th->th_dport = inp->inp_lport;
15655 		tcp_set_flags(th, ae->flags);
15656 		/* Now do we have a timestamp option? */
15657 		if (ae->flags & HAS_TSTMP) {
15658 			u_char *cp;
15659 			uint32_t val;
15660 
15661 			th->th_off = ((sizeof(struct tcphdr) + TCPOLEN_TSTAMP_APPA) >> 2);
15662 			cp = (u_char *)(th + 1);
15663 			*cp = TCPOPT_NOP;
15664 			cp++;
15665 			*cp = TCPOPT_NOP;
15666 			cp++;
15667 			*cp = TCPOPT_TIMESTAMP;
15668 			cp++;
15669 			*cp = TCPOLEN_TIMESTAMP;
15670 			cp++;
15671 			val = htonl(ae->ts_value);
15672 			bcopy((char *)&val,
15673 			      (char *)cp, sizeof(uint32_t));
15674 			val = htonl(ae->ts_echo);
15675 			bcopy((char *)&val,
15676 			      (char *)(cp + 4), sizeof(uint32_t));
15677 		} else
15678 			th->th_off = (sizeof(struct tcphdr) >> 2);
15679 
15680 		/*
15681 		 * For sane logging we need to play a little trick.
15682 		 * If the ack were fully processed we would have moved
15683 		 * snd_una to high_seq, but since compressed acks are
15684 		 * processed in two phases, at this point (logging) snd_una
15685 		 * won't be advanced. So we would see multiple acks showing
15686 		 * the advancement. We can prevent that by "pretending" that
15687 		 * snd_una was advanced and then un-advancing it so that the
15688 		 * logging code has the right value for tlb_snd_una.
15689 		 */
15690 		if (tp->snd_una != high_seq) {
15691 			orig_snd_una = tp->snd_una;
15692 			tp->snd_una = high_seq;
15693 			xx = 1;
15694 		} else
15695 			xx = 0;
15696 		TCP_LOG_EVENTP(tp, th,
15697 			       &tptosocket(tp)->so_rcv,
15698 			       &tptosocket(tp)->so_snd, TCP_LOG_IN, 0,
15699 			       0, &log, true, &ltv);
15700 		if (xx) {
15701 			tp->snd_una = orig_snd_una;
15702 		}
15703 	}
15704 
15705 }
15706 
15707 static void
15708 rack_handle_probe_response(struct tcp_rack *rack, uint32_t tiwin, uint32_t us_cts)
15709 {
15710 	uint32_t us_rtt;
15711 	/*
15712 	 * A persist or keep-alive was forced out, update our
15713 	 * min rtt time. Note now worry about lost responses.
15714 	 * When a subsequent keep-alive or persist times out
15715 	 * and forced_ack is still on, then the last probe
15716 	 * was not responded to. In such cases we have a
15717 	 * sysctl that controls the behavior. Either we apply
15718 	 * the rtt but with reduced confidence (0). Or we just
15719 	 * plain don't apply the rtt estimate. Having data flow
15720 	 * will clear the probe_not_answered flag i.e. cum-ack
15721 	 * move forward <or> exiting and reentering persists.
15722 	 */
15723 
15724 	rack->forced_ack = 0;
15725 	rack->rc_tp->t_rxtshift = 0;
15726 	if ((rack->rc_in_persist &&
15727 	     (tiwin == rack->rc_tp->snd_wnd)) ||
15728 	    (rack->rc_in_persist == 0)) {
15729 		/*
15730 		 * In persists only apply the RTT update if this is
15731 		 * a response to our window probe. And that
15732 		 * means the rwnd sent must match the current
15733 		 * snd_wnd. If it does not, then we got a
15734 		 * window update ack instead. For keepalive
15735 		 * we allow the answer no matter what the window.
15736 		 *
15737 		 * Note that if the probe_not_answered is set then
15738 		 * the forced_ack_ts is the oldest one i.e. the first
15739 		 * probe sent that might have been lost. This assures
15740 		 * us that if we do calculate an RTT it is longer not
15741 		 * some short thing.
15742 		 */
15743 		if (rack->rc_in_persist)
15744 			counter_u64_add(rack_persists_acks, 1);
15745 		us_rtt = us_cts - rack->r_ctl.forced_ack_ts;
15746 		if (us_rtt == 0)
15747 			us_rtt = 1;
15748 		if (rack->probe_not_answered == 0) {
15749 			rack_apply_updated_usrtt(rack, us_rtt, us_cts);
15750 			tcp_rack_xmit_timer(rack, us_rtt, 0, us_rtt, 3, NULL, 1);
15751 		} else {
15752 			/* We have a retransmitted probe here too */
15753 			if (rack_apply_rtt_with_reduced_conf) {
15754 				rack_apply_updated_usrtt(rack, us_rtt, us_cts);
15755 				tcp_rack_xmit_timer(rack, us_rtt, 0, us_rtt, 0, NULL, 1);
15756 			}
15757 		}
15758 	}
15759 }
15760 
15761 static int
15762 rack_do_compressed_ack_processing(struct tcpcb *tp, struct socket *so, struct mbuf *m, int nxt_pkt, struct timeval *tv)
15763 {
15764 	/*
15765 	 * Handle a "special" compressed ack mbuf. Each incoming
15766 	 * ack has only four possible dispositions:
15767 	 *
15768 	 * A) It moves the cum-ack forward
15769 	 * B) It is behind the cum-ack.
15770 	 * C) It is a window-update ack.
15771 	 * D) It is a dup-ack.
15772 	 *
15773 	 * Note that we can have between 1 -> TCP_COMP_ACK_ENTRIES
15774 	 * in the incoming mbuf. We also need to still pay attention
15775 	 * to nxt_pkt since there may be another packet after this
15776 	 * one.
15777 	 */
15778 #ifdef TCP_ACCOUNTING
15779 	uint64_t ts_val;
15780 	uint64_t rdstc;
15781 #endif
15782 	int segsiz;
15783 	struct timespec ts;
15784 	struct tcp_rack *rack;
15785 	struct tcp_ackent *ae;
15786 	uint32_t tiwin, ms_cts, cts, acked, acked_amount, high_seq, win_seq, the_win, win_upd_ack;
15787 	int cnt, i, did_out, ourfinisacked = 0;
15788 	struct tcpopt to_holder, *to = NULL;
15789 #ifdef TCP_ACCOUNTING
15790 	int win_up_req = 0;
15791 #endif
15792 	int nsegs = 0;
15793 	int under_pacing = 0;
15794 	int recovery = 0;
15795 #ifdef TCP_ACCOUNTING
15796 	sched_pin();
15797 #endif
15798 	rack = (struct tcp_rack *)tp->t_fb_ptr;
15799 	if (rack->gp_ready &&
15800 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT))
15801 		under_pacing = 1;
15802 
15803 	if (rack->r_state != tp->t_state)
15804 		rack_set_state(tp, rack);
15805 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
15806 	    (tp->t_flags & TF_GPUTINPROG)) {
15807 		/*
15808 		 * We have a goodput in progress
15809 		 * and we have entered a late state.
15810 		 * Do we have enough data in the sb
15811 		 * to handle the GPUT request?
15812 		 */
15813 		uint32_t bytes;
15814 
15815 		bytes = tp->gput_ack - tp->gput_seq;
15816 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
15817 			bytes += tp->gput_seq - tp->snd_una;
15818 		if (bytes > sbavail(&tptosocket(tp)->so_snd)) {
15819 			/*
15820 			 * There are not enough bytes in the socket
15821 			 * buffer that have been sent to cover this
15822 			 * measurement. Cancel it.
15823 			 */
15824 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
15825 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
15826 						   tp->gput_seq,
15827 						   0, 0, 18, __LINE__, NULL, 0);
15828 			tp->t_flags &= ~TF_GPUTINPROG;
15829 		}
15830 	}
15831 	to = &to_holder;
15832 	to->to_flags = 0;
15833 	KASSERT((m->m_len >= sizeof(struct tcp_ackent)),
15834 		("tp:%p m_cmpack:%p with invalid len:%u", tp, m, m->m_len));
15835 	cnt = m->m_len / sizeof(struct tcp_ackent);
15836 	counter_u64_add(rack_multi_single_eq, cnt);
15837 	high_seq = tp->snd_una;
15838 	the_win = tp->snd_wnd;
15839 	win_seq = tp->snd_wl1;
15840 	win_upd_ack = tp->snd_wl2;
15841 	cts = tcp_tv_to_usectick(tv);
15842 	ms_cts = tcp_tv_to_mssectick(tv);
15843 	rack->r_ctl.rc_rcvtime = cts;
15844 	segsiz = ctf_fixed_maxseg(tp);
15845 	if ((rack->rc_gp_dyn_mul) &&
15846 	    (rack->use_fixed_rate == 0) &&
15847 	    (rack->rc_always_pace)) {
15848 		/* Check in on probertt */
15849 		rack_check_probe_rtt(rack, cts);
15850 	}
15851 	for (i = 0; i < cnt; i++) {
15852 #ifdef TCP_ACCOUNTING
15853 		ts_val = get_cyclecount();
15854 #endif
15855 		rack_clear_rate_sample(rack);
15856 		ae = ((mtod(m, struct tcp_ackent *)) + i);
15857 		if (ae->flags & TH_FIN)
15858 			rack_log_pacing_delay_calc(rack,
15859 						   0,
15860 						   0,
15861 						   0,
15862 						   rack_get_gp_est(rack), /* delRate */
15863 						   rack_get_lt_bw(rack), /* rttProp */
15864 						   20, __LINE__, NULL, 0);
15865 		/* Setup the window */
15866 		tiwin = ae->win << tp->snd_scale;
15867 		if (tiwin > rack->r_ctl.rc_high_rwnd)
15868 			rack->r_ctl.rc_high_rwnd = tiwin;
15869 		/* figure out the type of ack */
15870 		if (SEQ_LT(ae->ack, high_seq)) {
15871 			/* Case B*/
15872 			ae->ack_val_set = ACK_BEHIND;
15873 		} else if (SEQ_GT(ae->ack, high_seq)) {
15874 			/* Case A */
15875 			ae->ack_val_set = ACK_CUMACK;
15876 		} else if ((tiwin == the_win) && (rack->rc_in_persist == 0)){
15877 			/* Case D */
15878 			ae->ack_val_set = ACK_DUPACK;
15879 		} else {
15880 			/* Case C */
15881 			ae->ack_val_set = ACK_RWND;
15882 		}
15883 		if (rack->sack_attack_disable > 0) {
15884 			rack_log_type_bbrsnd(rack, 0, 0, cts, tv, __LINE__);
15885 			rack->r_ctl.ack_during_sd++;
15886 		}
15887 		rack_log_input_packet(tp, rack, ae, ae->ack_val_set, high_seq);
15888 		/* Validate timestamp */
15889 		if (ae->flags & HAS_TSTMP) {
15890 			/* Setup for a timestamp */
15891 			to->to_flags = TOF_TS;
15892 			ae->ts_echo -= tp->ts_offset;
15893 			to->to_tsecr = ae->ts_echo;
15894 			to->to_tsval = ae->ts_value;
15895 			/*
15896 			 * If echoed timestamp is later than the current time, fall back to
15897 			 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
15898 			 * were used when this connection was established.
15899 			 */
15900 			if (TSTMP_GT(ae->ts_echo, ms_cts))
15901 				to->to_tsecr = 0;
15902 			if (tp->ts_recent &&
15903 			    TSTMP_LT(ae->ts_value, tp->ts_recent)) {
15904 				if (ctf_ts_check_ac(tp, (ae->flags & 0xff))) {
15905 #ifdef TCP_ACCOUNTING
15906 					rdstc = get_cyclecount();
15907 					if (rdstc > ts_val) {
15908 						if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
15909 							tp->tcp_proc_time[ae->ack_val_set] += (rdstc - ts_val);
15910 						}
15911 					}
15912 #endif
15913 					continue;
15914 				}
15915 			}
15916 			if (SEQ_LEQ(ae->seq, tp->last_ack_sent) &&
15917 			    SEQ_LEQ(tp->last_ack_sent, ae->seq)) {
15918 				tp->ts_recent_age = tcp_ts_getticks();
15919 				tp->ts_recent = ae->ts_value;
15920 			}
15921 		} else {
15922 			/* Setup for a no options */
15923 			to->to_flags = 0;
15924 		}
15925 		/* Update the rcv time and perform idle reduction possibly */
15926 		if  (tp->t_idle_reduce &&
15927 		     (tp->snd_max == tp->snd_una) &&
15928 		     (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
15929 			counter_u64_add(rack_input_idle_reduces, 1);
15930 			rack_cc_after_idle(rack, tp);
15931 		}
15932 		tp->t_rcvtime = ticks;
15933 		/* Now what about ECN of a chain of pure ACKs? */
15934 		if (tcp_ecn_input_segment(tp, ae->flags, 0,
15935 			tcp_packets_this_ack(tp, ae->ack),
15936 			ae->codepoint))
15937 			rack_cong_signal(tp, CC_ECN, ae->ack, __LINE__);
15938 #ifdef TCP_ACCOUNTING
15939 		/* Count for the specific type of ack in */
15940 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
15941 			tp->tcp_cnt_counters[ae->ack_val_set]++;
15942 		}
15943 #endif
15944 		/*
15945 		 * Note how we could move up these in the determination
15946 		 * above, but we don't so that way the timestamp checks (and ECN)
15947 		 * is done first before we do any processing on the ACK.
15948 		 * The non-compressed path through the code has this
15949 		 * weakness (noted by @jtl) that it actually does some
15950 		 * processing before verifying the timestamp information.
15951 		 * We don't take that path here which is why we set
15952 		 * the ack_val_set first, do the timestamp and ecn
15953 		 * processing, and then look at what we have setup.
15954 		 */
15955 		if (ae->ack_val_set == ACK_BEHIND) {
15956 			/*
15957 			 * Case B flag reordering, if window is not closed
15958 			 * or it could be a keep-alive or persists
15959 			 */
15960 			if (SEQ_LT(ae->ack, tp->snd_una) && (sbspace(&so->so_rcv) > segsiz)) {
15961 				rack->r_ctl.rc_reorder_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
15962 				if (rack->r_ctl.rc_reorder_ts == 0)
15963 					rack->r_ctl.rc_reorder_ts = 1;
15964 			}
15965 		} else if (ae->ack_val_set == ACK_DUPACK) {
15966 			/* Case D */
15967 			rack_strike_dupack(rack);
15968 		} else if (ae->ack_val_set == ACK_RWND) {
15969 			/* Case C */
15970 			if ((ae->flags & TSTMP_LRO) || (ae->flags & TSTMP_HDWR)) {
15971 				ts.tv_sec = ae->timestamp / 1000000000;
15972 				ts.tv_nsec = ae->timestamp % 1000000000;
15973 				rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
15974 				rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
15975 			} else {
15976 				rack->r_ctl.act_rcv_time = *tv;
15977 			}
15978 			if (rack->forced_ack) {
15979 				rack_handle_probe_response(rack, tiwin,
15980 							   tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time));
15981 			}
15982 #ifdef TCP_ACCOUNTING
15983 			win_up_req = 1;
15984 #endif
15985 			win_upd_ack = ae->ack;
15986 			win_seq = ae->seq;
15987 			the_win = tiwin;
15988 			rack_do_win_updates(tp, rack, the_win, win_seq, win_upd_ack, cts);
15989 		} else {
15990 			/* Case A */
15991 			if (SEQ_GT(ae->ack, tp->snd_max)) {
15992 				/*
15993 				 * We just send an ack since the incoming
15994 				 * ack is beyond the largest seq we sent.
15995 				 */
15996 				if ((tp->t_flags & TF_ACKNOW) == 0) {
15997 					ctf_ack_war_checks(tp, &rack->r_ctl.challenge_ack_ts, &rack->r_ctl.challenge_ack_cnt);
15998 					if (tp->t_flags && TF_ACKNOW)
15999 						rack->r_wanted_output = 1;
16000 				}
16001 			} else {
16002 				nsegs++;
16003 				/* If the window changed setup to update */
16004 				if (tiwin != tp->snd_wnd) {
16005 					win_upd_ack = ae->ack;
16006 					win_seq = ae->seq;
16007 					the_win = tiwin;
16008 					rack_do_win_updates(tp, rack, the_win, win_seq, win_upd_ack, cts);
16009 				}
16010 #ifdef TCP_ACCOUNTING
16011 				/* Account for the acks */
16012 				if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16013 					tp->tcp_cnt_counters[CNT_OF_ACKS_IN] += (((ae->ack - high_seq) + segsiz - 1) / segsiz);
16014 				}
16015 #endif
16016 				high_seq = ae->ack;
16017 				if (rack_verbose_logging && tcp_bblogging_on(rack->rc_tp))
16018 					rack_log_hystart_event(rack, high_seq, 8);
16019 				/* Setup our act_rcv_time */
16020 				if ((ae->flags & TSTMP_LRO) || (ae->flags & TSTMP_HDWR)) {
16021 					ts.tv_sec = ae->timestamp / 1000000000;
16022 					ts.tv_nsec = ae->timestamp % 1000000000;
16023 					rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
16024 					rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
16025 				} else {
16026 					rack->r_ctl.act_rcv_time = *tv;
16027 				}
16028 				rack_process_to_cumack(tp, rack, ae->ack, cts, to,
16029 						       tcp_tv_to_lusectick(&rack->r_ctl.act_rcv_time));
16030 #ifdef TCP_REQUEST_TRK
16031 				rack_http_check_for_comp(rack, high_seq);
16032 #endif
16033 				if (rack->rc_dsack_round_seen) {
16034 					/* Is the dsack round over? */
16035 					if (SEQ_GEQ(ae->ack, rack->r_ctl.dsack_round_end)) {
16036 						/* Yes it is */
16037 						rack->rc_dsack_round_seen = 0;
16038 						rack_log_dsack_event(rack, 3, __LINE__, 0, 0);
16039 					}
16040 				}
16041 			}
16042 		}
16043 		/* And lets be sure to commit the rtt measurements for this ack */
16044 		tcp_rack_xmit_timer_commit(rack, tp);
16045 #ifdef TCP_ACCOUNTING
16046 		rdstc = get_cyclecount();
16047 		if (rdstc > ts_val) {
16048 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16049 				tp->tcp_proc_time[ae->ack_val_set] += (rdstc - ts_val);
16050 				if (ae->ack_val_set == ACK_CUMACK)
16051 					tp->tcp_proc_time[CYC_HANDLE_MAP] += (rdstc - ts_val);
16052 			}
16053 		}
16054 #endif
16055 	}
16056 #ifdef TCP_ACCOUNTING
16057 	ts_val = get_cyclecount();
16058 #endif
16059 	/* Tend to any collapsed window */
16060 	if (SEQ_GT(tp->snd_max, high_seq) && (tp->snd_wnd < (tp->snd_max - high_seq))) {
16061 		/* The peer collapsed the window */
16062 		rack_collapsed_window(rack, (tp->snd_max - high_seq), high_seq, __LINE__);
16063 	} else if (rack->rc_has_collapsed)
16064 		rack_un_collapse_window(rack, __LINE__);
16065 	if ((rack->r_collapse_point_valid) &&
16066 	    (SEQ_GT(high_seq, rack->r_ctl.high_collapse_point)))
16067 		rack->r_collapse_point_valid = 0;
16068 	acked_amount = acked = (high_seq - tp->snd_una);
16069 	if (acked) {
16070 		/*
16071 		 * The draft (v3) calls for us to use SEQ_GEQ, but that
16072 		 * causes issues when we are just going app limited. Lets
16073 		 * instead use SEQ_GT <or> where its equal but more data
16074 		 * is outstanding.
16075 		 *
16076 		 * Also make sure we are on the last ack of a series. We
16077 		 * have to have all the ack's processed in queue to know
16078 		 * if there is something left outstanding.
16079 		 *
16080 		 */
16081 		if (SEQ_GEQ(high_seq, rack->r_ctl.roundends) &&
16082 		    (rack->rc_new_rnd_needed == 0) &&
16083 		    (nxt_pkt == 0)) {
16084 			rack_log_hystart_event(rack, high_seq, 21);
16085 			rack->r_ctl.current_round++;
16086 			/* Force the next send to setup the next round */
16087 			rack->rc_new_rnd_needed = 1;
16088 			if (CC_ALGO(tp)->newround != NULL) {
16089 				CC_ALGO(tp)->newround(&tp->t_ccv, rack->r_ctl.current_round);
16090 			}
16091 		}
16092 		/*
16093 		 * Clear the probe not answered flag
16094 		 * since cum-ack moved forward.
16095 		 */
16096 		rack->probe_not_answered = 0;
16097 		if (rack->sack_attack_disable == 0)
16098 			rack_do_decay(rack);
16099 		if (acked >= segsiz) {
16100 			/*
16101 			 * You only get credit for
16102 			 * MSS and greater (and you get extra
16103 			 * credit for larger cum-ack moves).
16104 			 */
16105 			int ac;
16106 
16107 			ac = acked / segsiz;
16108 			rack->r_ctl.ack_count += ac;
16109 			counter_u64_add(rack_ack_total, ac);
16110 		}
16111 		if (rack->r_ctl.ack_count > 0xfff00000) {
16112 			/*
16113 			 * reduce the number to keep us under
16114 			 * a uint32_t.
16115 			 */
16116 			rack->r_ctl.ack_count /= 2;
16117 			rack->r_ctl.sack_count /= 2;
16118 		}
16119 		if (tp->t_flags & TF_NEEDSYN) {
16120 			/*
16121 			 * T/TCP: Connection was half-synchronized, and our SYN has
16122 			 * been ACK'd (so connection is now fully synchronized).  Go
16123 			 * to non-starred state, increment snd_una for ACK of SYN,
16124 			 * and check if we can do window scaling.
16125 			 */
16126 			tp->t_flags &= ~TF_NEEDSYN;
16127 			tp->snd_una++;
16128 			acked_amount = acked = (high_seq - tp->snd_una);
16129 		}
16130 		if (acked > sbavail(&so->so_snd))
16131 			acked_amount = sbavail(&so->so_snd);
16132 #ifdef TCP_SAD_DETECTION
16133 		/*
16134 		 * We only care on a cum-ack move if we are in a sack-disabled
16135 		 * state. We have already added in to the ack_count, and we never
16136 		 * would disable on a cum-ack move, so we only care to do the
16137 		 * detection if it may "undo" it, i.e. we were in disabled already.
16138 		 */
16139 		if (rack->sack_attack_disable)
16140 			rack_do_detection(tp, rack, acked_amount, segsiz);
16141 #endif
16142 		if (IN_FASTRECOVERY(tp->t_flags) &&
16143 		    (rack->rack_no_prr == 0))
16144 			rack_update_prr(tp, rack, acked_amount, high_seq);
16145 		if (IN_RECOVERY(tp->t_flags)) {
16146 			if (SEQ_LT(high_seq, tp->snd_recover) &&
16147 			    (SEQ_LT(high_seq, tp->snd_max))) {
16148 				tcp_rack_partialack(tp);
16149 			} else {
16150 				rack_post_recovery(tp, high_seq);
16151 				recovery = 1;
16152 			}
16153 		}
16154 		/* Handle the rack-log-ack part (sendmap) */
16155 		if ((sbused(&so->so_snd) == 0) &&
16156 		    (acked > acked_amount) &&
16157 		    (tp->t_state >= TCPS_FIN_WAIT_1) &&
16158 		    (tp->t_flags & TF_SENTFIN)) {
16159 			/*
16160 			 * We must be sure our fin
16161 			 * was sent and acked (we can be
16162 			 * in FIN_WAIT_1 without having
16163 			 * sent the fin).
16164 			 */
16165 			ourfinisacked = 1;
16166 			/*
16167 			 * Lets make sure snd_una is updated
16168 			 * since most likely acked_amount = 0 (it
16169 			 * should be).
16170 			 */
16171 			tp->snd_una = high_seq;
16172 		}
16173 		/* Did we make a RTO error? */
16174 		if ((tp->t_flags & TF_PREVVALID) &&
16175 		    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
16176 			tp->t_flags &= ~TF_PREVVALID;
16177 			if (tp->t_rxtshift == 1 &&
16178 			    (int)(ticks - tp->t_badrxtwin) < 0)
16179 				rack_cong_signal(tp, CC_RTO_ERR, high_seq, __LINE__);
16180 		}
16181 		/* Handle the data in the socket buffer */
16182 		KMOD_TCPSTAT_ADD(tcps_rcvackpack, 1);
16183 		KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
16184 		if (acked_amount > 0) {
16185 			struct mbuf *mfree;
16186 
16187 			rack_ack_received(tp, rack, high_seq, nsegs, CC_ACK, recovery);
16188 			SOCKBUF_LOCK(&so->so_snd);
16189 			mfree = sbcut_locked(&so->so_snd, acked_amount);
16190 			tp->snd_una = high_seq;
16191 			/* Note we want to hold the sb lock through the sendmap adjust */
16192 			rack_adjust_sendmap_head(rack, &so->so_snd);
16193 			/* Wake up the socket if we have room to write more */
16194 			rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
16195 			sowwakeup_locked(so);
16196 			if ((recovery == 1) &&
16197 			    (rack->excess_rxt_on) &&
16198 			    (rack->r_cwnd_was_clamped == 0)) {
16199 				do_rack_excess_rxt(tp, rack);
16200 			} else if (rack->r_cwnd_was_clamped)
16201 				do_rack_check_for_unclamp(tp, rack);
16202 			m_freem(mfree);
16203 		}
16204 		/* update progress */
16205 		tp->t_acktime = ticks;
16206 		rack_log_progress_event(rack, tp, tp->t_acktime,
16207 					PROGRESS_UPDATE, __LINE__);
16208 		/* Clear out shifts and such */
16209 		tp->t_rxtshift = 0;
16210 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
16211 				   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
16212 		rack->rc_tlp_in_progress = 0;
16213 		rack->r_ctl.rc_tlp_cnt_out = 0;
16214 		/* Send recover and snd_nxt must be dragged along */
16215 		if (SEQ_GT(tp->snd_una, tp->snd_recover))
16216 			tp->snd_recover = tp->snd_una;
16217 		if (SEQ_LT(tp->snd_nxt, tp->snd_una))
16218 			tp->snd_nxt = tp->snd_una;
16219 		/*
16220 		 * If the RXT timer is running we want to
16221 		 * stop it, so we can restart a TLP (or new RXT).
16222 		 */
16223 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
16224 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
16225 		tp->snd_wl2 = high_seq;
16226 		tp->t_dupacks = 0;
16227 		if (under_pacing &&
16228 		    (rack->use_fixed_rate == 0) &&
16229 		    (rack->in_probe_rtt == 0) &&
16230 		    rack->rc_gp_dyn_mul &&
16231 		    rack->rc_always_pace) {
16232 			/* Check if we are dragging bottom */
16233 			rack_check_bottom_drag(tp, rack, so);
16234 		}
16235 		if (tp->snd_una == tp->snd_max) {
16236 			tp->t_flags &= ~TF_PREVVALID;
16237 			rack->r_ctl.retran_during_recovery = 0;
16238 			rack->rc_suspicious = 0;
16239 			rack->r_ctl.dsack_byte_cnt = 0;
16240 			rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
16241 			if (rack->r_ctl.rc_went_idle_time == 0)
16242 				rack->r_ctl.rc_went_idle_time = 1;
16243 			rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
16244 			if (sbavail(&tptosocket(tp)->so_snd) == 0)
16245 				tp->t_acktime = 0;
16246 			/* Set so we might enter persists... */
16247 			rack->r_wanted_output = 1;
16248 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
16249 			sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
16250 			if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
16251 			    (sbavail(&so->so_snd) == 0) &&
16252 			    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
16253 				/*
16254 				 * The socket was gone and the
16255 				 * peer sent data (not now in the past), time to
16256 				 * reset him.
16257 				 */
16258 				rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
16259 				/* tcp_close will kill the inp pre-log the Reset */
16260 				tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
16261 #ifdef TCP_ACCOUNTING
16262 				rdstc = get_cyclecount();
16263 				if (rdstc > ts_val) {
16264 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16265 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16266 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16267 					}
16268 				}
16269 #endif
16270 				m_freem(m);
16271 				tp = tcp_close(tp);
16272 				if (tp == NULL) {
16273 #ifdef TCP_ACCOUNTING
16274 					sched_unpin();
16275 #endif
16276 					return (1);
16277 				}
16278 				/*
16279 				 * We would normally do drop-with-reset which would
16280 				 * send back a reset. We can't since we don't have
16281 				 * all the needed bits. Instead lets arrange for
16282 				 * a call to tcp_output(). That way since we
16283 				 * are in the closed state we will generate a reset.
16284 				 *
16285 				 * Note if tcp_accounting is on we don't unpin since
16286 				 * we do that after the goto label.
16287 				 */
16288 				goto send_out_a_rst;
16289 			}
16290 			if ((sbused(&so->so_snd) == 0) &&
16291 			    (tp->t_state >= TCPS_FIN_WAIT_1) &&
16292 			    (tp->t_flags & TF_SENTFIN)) {
16293 				/*
16294 				 * If we can't receive any more data, then closing user can
16295 				 * proceed. Starting the timer is contrary to the
16296 				 * specification, but if we don't get a FIN we'll hang
16297 				 * forever.
16298 				 *
16299 				 */
16300 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
16301 					soisdisconnected(so);
16302 					tcp_timer_activate(tp, TT_2MSL,
16303 							   (tcp_fast_finwait2_recycle ?
16304 							    tcp_finwait2_timeout :
16305 							    TP_MAXIDLE(tp)));
16306 				}
16307 				if (ourfinisacked == 0) {
16308 					/*
16309 					 * We don't change to fin-wait-2 if we have our fin acked
16310 					 * which means we are probably in TCPS_CLOSING.
16311 					 */
16312 					tcp_state_change(tp, TCPS_FIN_WAIT_2);
16313 				}
16314 			}
16315 		}
16316 		/* Wake up the socket if we have room to write more */
16317 		if (sbavail(&so->so_snd)) {
16318 			rack->r_wanted_output = 1;
16319 			if (ctf_progress_timeout_check(tp, true)) {
16320 				rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
16321 							tp, tick, PROGRESS_DROP, __LINE__);
16322 				/*
16323 				 * We cheat here and don't send a RST, we should send one
16324 				 * when the pacer drops the connection.
16325 				 */
16326 #ifdef TCP_ACCOUNTING
16327 				rdstc = get_cyclecount();
16328 				if (rdstc > ts_val) {
16329 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16330 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16331 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16332 					}
16333 				}
16334 				sched_unpin();
16335 #endif
16336 				(void)tcp_drop(tp, ETIMEDOUT);
16337 				m_freem(m);
16338 				return (1);
16339 			}
16340 		}
16341 		if (ourfinisacked) {
16342 			switch(tp->t_state) {
16343 			case TCPS_CLOSING:
16344 #ifdef TCP_ACCOUNTING
16345 				rdstc = get_cyclecount();
16346 				if (rdstc > ts_val) {
16347 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16348 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16349 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16350 					}
16351 				}
16352 				sched_unpin();
16353 #endif
16354 				tcp_twstart(tp);
16355 				m_freem(m);
16356 				return (1);
16357 				break;
16358 			case TCPS_LAST_ACK:
16359 #ifdef TCP_ACCOUNTING
16360 				rdstc = get_cyclecount();
16361 				if (rdstc > ts_val) {
16362 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16363 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16364 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16365 					}
16366 				}
16367 				sched_unpin();
16368 #endif
16369 				tp = tcp_close(tp);
16370 				ctf_do_drop(m, tp);
16371 				return (1);
16372 				break;
16373 			case TCPS_FIN_WAIT_1:
16374 #ifdef TCP_ACCOUNTING
16375 				rdstc = get_cyclecount();
16376 				if (rdstc > ts_val) {
16377 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16378 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16379 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16380 					}
16381 				}
16382 #endif
16383 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
16384 					soisdisconnected(so);
16385 					tcp_timer_activate(tp, TT_2MSL,
16386 							   (tcp_fast_finwait2_recycle ?
16387 							    tcp_finwait2_timeout :
16388 							    TP_MAXIDLE(tp)));
16389 				}
16390 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
16391 				break;
16392 			default:
16393 				break;
16394 			}
16395 		}
16396 		if (rack->r_fast_output) {
16397 			/*
16398 			 * We re doing fast output.. can we expand that?
16399 			 */
16400 			rack_gain_for_fastoutput(rack, tp, so, acked_amount);
16401 		}
16402 #ifdef TCP_ACCOUNTING
16403 		rdstc = get_cyclecount();
16404 		if (rdstc > ts_val) {
16405 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16406 				tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
16407 				tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
16408 			}
16409 		}
16410 
16411 	} else if (win_up_req) {
16412 		rdstc = get_cyclecount();
16413 		if (rdstc > ts_val) {
16414 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16415 				tp->tcp_proc_time[ACK_RWND] += (rdstc - ts_val);
16416 			}
16417 		}
16418 #endif
16419 	}
16420 	/* Now is there a next packet, if so we are done */
16421 	m_freem(m);
16422 	did_out = 0;
16423 	if (nxt_pkt) {
16424 #ifdef TCP_ACCOUNTING
16425 		sched_unpin();
16426 #endif
16427 		rack_log_doseg_done(rack, cts, nxt_pkt, did_out, 5, nsegs);
16428 		return (0);
16429 	}
16430 	rack_handle_might_revert(tp, rack);
16431 	ctf_calc_rwin(so, tp);
16432 	if ((rack->r_wanted_output != 0) || (rack->r_fast_output != 0)) {
16433 	send_out_a_rst:
16434 		if (tcp_output(tp) < 0) {
16435 #ifdef TCP_ACCOUNTING
16436 			sched_unpin();
16437 #endif
16438 			return (1);
16439 		}
16440 		did_out = 1;
16441 	}
16442 	if (tp->t_flags2 & TF2_HPTS_CALLS)
16443 		tp->t_flags2 &= ~TF2_HPTS_CALLS;
16444 	rack_free_trim(rack);
16445 #ifdef TCP_ACCOUNTING
16446 	sched_unpin();
16447 #endif
16448 	rack_timer_audit(tp, rack, &so->so_snd);
16449 	rack_log_doseg_done(rack, cts, nxt_pkt, did_out, 6, nsegs);
16450 	return (0);
16451 }
16452 
16453 #define	TCP_LRO_TS_OPTION \
16454     ntohl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | \
16455 	  (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP)
16456 
16457 static int
16458 rack_do_segment_nounlock(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
16459     int32_t drop_hdrlen, int32_t tlen, uint8_t iptos, int32_t nxt_pkt,
16460     struct timeval *tv)
16461 {
16462 	struct inpcb *inp = tptoinpcb(tp);
16463 	struct socket *so = tptosocket(tp);
16464 #ifdef TCP_ACCOUNTING
16465 	uint64_t ts_val;
16466 #endif
16467 	int32_t thflags, retval, did_out = 0;
16468 	int32_t way_out = 0;
16469 	/*
16470 	 * cts - is the current time from tv (caller gets ts) in microseconds.
16471 	 * ms_cts - is the current time from tv in milliseconds.
16472 	 * us_cts - is the time that LRO or hardware actually got the packet in microseconds.
16473 	 */
16474 	uint32_t cts, us_cts, ms_cts;
16475 	uint32_t tiwin, high_seq;
16476 	struct timespec ts;
16477 	struct tcpopt to;
16478 	struct tcp_rack *rack;
16479 	struct rack_sendmap *rsm;
16480 	int32_t prev_state = 0;
16481 	int no_output = 0;
16482 	int slot_remaining = 0;
16483 #ifdef TCP_ACCOUNTING
16484 	int ack_val_set = 0xf;
16485 #endif
16486 	int nsegs;
16487 
16488 	NET_EPOCH_ASSERT();
16489 	INP_WLOCK_ASSERT(inp);
16490 
16491 	/*
16492 	 * tv passed from common code is from either M_TSTMP_LRO or
16493 	 * tcp_get_usecs() if no LRO m_pkthdr timestamp is present.
16494 	 */
16495 	rack = (struct tcp_rack *)tp->t_fb_ptr;
16496 	if (rack->rack_deferred_inited == 0) {
16497 		/*
16498 		 * If we are the connecting socket we will
16499 		 * hit rack_init() when no sequence numbers
16500 		 * are setup. This makes it so we must defer
16501 		 * some initialization. Call that now.
16502 		 */
16503 		rack_deferred_init(tp, rack);
16504 	}
16505 	/*
16506 	 * Check to see if we need to skip any output plans. This
16507 	 * can happen in the non-LRO path where we are pacing and
16508 	 * must process the ack coming in but need to defer sending
16509 	 * anything becase a pacing timer is running.
16510 	 */
16511 	us_cts = tcp_tv_to_usectick(tv);
16512 	if (m->m_flags & M_ACKCMP) {
16513 		/*
16514 		 * All compressed ack's are ack's by definition so
16515 		 * remove any ack required flag and then do the processing.
16516 		 */
16517 		rack->rc_ack_required = 0;
16518 		return (rack_do_compressed_ack_processing(tp, so, m, nxt_pkt, tv));
16519 	}
16520 	thflags = tcp_get_flags(th);
16521 	if ((rack->rc_always_pace == 1) &&
16522 	    (rack->rc_ack_can_sendout_data == 0) &&
16523 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
16524 	    (TSTMP_LT(us_cts, rack->r_ctl.rc_last_output_to))) {
16525 		/*
16526 		 * Ok conditions are right for queuing the packets
16527 		 * but we do have to check the flags in the inp, it
16528 		 * could be, if a sack is present, we want to be awoken and
16529 		 * so should process the packets.
16530 		 */
16531 		slot_remaining = rack->r_ctl.rc_last_output_to - us_cts;
16532 		if (rack->rc_tp->t_flags2 & TF2_DONT_SACK_QUEUE) {
16533 			no_output = 1;
16534 		} else {
16535 			/*
16536 			 * If there is no options, or just a
16537 			 * timestamp option, we will want to queue
16538 			 * the packets. This is the same that LRO does
16539 			 * and will need to change with accurate ECN.
16540 			 */
16541 			uint32_t *ts_ptr;
16542 			int optlen;
16543 
16544 			optlen = (th->th_off << 2) - sizeof(struct tcphdr);
16545 			ts_ptr = (uint32_t *)(th + 1);
16546 			if ((optlen == 0) ||
16547 			    ((optlen == TCPOLEN_TSTAMP_APPA) &&
16548 			     (*ts_ptr == TCP_LRO_TS_OPTION)))
16549 				no_output = 1;
16550 		}
16551 		if ((no_output == 1) && (slot_remaining < tcp_min_hptsi_time)) {
16552 			/*
16553 			 * It is unrealistic to think we can pace in less than
16554 			 * the minimum granularity of the pacer (def:250usec). So
16555 			 * if we have less than that time remaining we should go
16556 			 * ahead and allow output to be "early". We will attempt to
16557 			 * make up for it in any pacing time we try to apply on
16558 			 * the outbound packet.
16559 			 */
16560 			no_output = 0;
16561 		}
16562 	}
16563 	/*
16564 	 * If there is a RST or FIN lets dump out the bw
16565 	 * with a FIN the connection may go on but we
16566 	 * may not.
16567 	 */
16568 	if ((thflags & TH_FIN) || (thflags & TH_RST))
16569 		rack_log_pacing_delay_calc(rack,
16570 					   rack->r_ctl.gp_bw,
16571 					   0,
16572 					   0,
16573 					   rack_get_gp_est(rack), /* delRate */
16574 					   rack_get_lt_bw(rack), /* rttProp */
16575 					   20, __LINE__, NULL, 0);
16576 	if (m->m_flags & M_ACKCMP) {
16577 		panic("Impossible reach m has ackcmp? m:%p tp:%p", m, tp);
16578 	}
16579 	cts = tcp_tv_to_usectick(tv);
16580 	ms_cts =  tcp_tv_to_mssectick(tv);
16581 	nsegs = m->m_pkthdr.lro_nsegs;
16582 	counter_u64_add(rack_proc_non_comp_ack, 1);
16583 #ifdef TCP_ACCOUNTING
16584 	sched_pin();
16585 	if (thflags & TH_ACK)
16586 		ts_val = get_cyclecount();
16587 #endif
16588 	if ((m->m_flags & M_TSTMP) ||
16589 	    (m->m_flags & M_TSTMP_LRO)) {
16590 		mbuf_tstmp2timespec(m, &ts);
16591 		rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
16592 		rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
16593 	} else
16594 		rack->r_ctl.act_rcv_time = *tv;
16595 	kern_prefetch(rack, &prev_state);
16596 	prev_state = 0;
16597 	/*
16598 	 * Unscale the window into a 32-bit value. For the SYN_SENT state
16599 	 * the scale is zero.
16600 	 */
16601 	tiwin = th->th_win << tp->snd_scale;
16602 #ifdef TCP_ACCOUNTING
16603 	if (thflags & TH_ACK) {
16604 		/*
16605 		 * We have a tradeoff here. We can either do what we are
16606 		 * doing i.e. pinning to this CPU and then doing the accounting
16607 		 * <or> we could do a critical enter, setup the rdtsc and cpu
16608 		 * as in below, and then validate we are on the same CPU on
16609 		 * exit. I have choosen to not do the critical enter since
16610 		 * that often will gain you a context switch, and instead lock
16611 		 * us (line above this if) to the same CPU with sched_pin(). This
16612 		 * means we may be context switched out for a higher priority
16613 		 * interupt but we won't be moved to another CPU.
16614 		 *
16615 		 * If this occurs (which it won't very often since we most likely
16616 		 * are running this code in interupt context and only a higher
16617 		 * priority will bump us ... clock?) we will falsely add in
16618 		 * to the time the interupt processing time plus the ack processing
16619 		 * time. This is ok since its a rare event.
16620 		 */
16621 		ack_val_set = tcp_do_ack_accounting(tp, th, &to, tiwin,
16622 						    ctf_fixed_maxseg(tp));
16623 	}
16624 #endif
16625 	/*
16626 	 * Parse options on any incoming segment.
16627 	 */
16628 	memset(&to, 0, sizeof(to));
16629 	tcp_dooptions(&to, (u_char *)(th + 1),
16630 	    (th->th_off << 2) - sizeof(struct tcphdr),
16631 	    (thflags & TH_SYN) ? TO_SYN : 0);
16632 	KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN",
16633 	    __func__));
16634 	KASSERT(tp->t_state != TCPS_TIME_WAIT, ("%s: TCPS_TIME_WAIT",
16635 	    __func__));
16636 
16637 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
16638 	    (tp->t_flags & TF_GPUTINPROG)) {
16639 		/*
16640 		 * We have a goodput in progress
16641 		 * and we have entered a late state.
16642 		 * Do we have enough data in the sb
16643 		 * to handle the GPUT request?
16644 		 */
16645 		uint32_t bytes;
16646 
16647 		bytes = tp->gput_ack - tp->gput_seq;
16648 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
16649 			bytes += tp->gput_seq - tp->snd_una;
16650 		if (bytes > sbavail(&tptosocket(tp)->so_snd)) {
16651 			/*
16652 			 * There are not enough bytes in the socket
16653 			 * buffer that have been sent to cover this
16654 			 * measurement. Cancel it.
16655 			 */
16656 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
16657 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
16658 						   tp->gput_seq,
16659 						   0, 0, 18, __LINE__, NULL, 0);
16660 			tp->t_flags &= ~TF_GPUTINPROG;
16661 		}
16662 	}
16663 	high_seq = th->th_ack;
16664 	if (tcp_bblogging_on(rack->rc_tp)) {
16665 		union tcp_log_stackspecific log;
16666 		struct timeval ltv;
16667 #ifdef TCP_REQUEST_TRK
16668 		struct http_sendfile_track *http_req;
16669 
16670 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
16671 			http_req = tcp_http_find_req_for_seq(tp, (th->th_ack-1));
16672 		} else {
16673 			http_req = tcp_http_find_req_for_seq(tp, th->th_ack);
16674 		}
16675 #endif
16676 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
16677 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
16678 		if (rack->rack_no_prr == 0)
16679 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
16680 		else
16681 			log.u_bbr.flex1 = 0;
16682 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
16683 		log.u_bbr.use_lt_bw <<= 1;
16684 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
16685 		log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
16686 		log.u_bbr.bbr_state = rack->rc_free_cnt;
16687 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
16688 		log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
16689 		log.u_bbr.flex3 = m->m_flags;
16690 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
16691 		log.u_bbr.lost = thflags;
16692 		log.u_bbr.pacing_gain = 0x1;
16693 #ifdef TCP_ACCOUNTING
16694 		log.u_bbr.cwnd_gain = ack_val_set;
16695 #endif
16696 		log.u_bbr.flex7 = 2;
16697 		if (m->m_flags & M_TSTMP) {
16698 			/* Record the hardware timestamp if present */
16699 			mbuf_tstmp2timespec(m, &ts);
16700 			ltv.tv_sec = ts.tv_sec;
16701 			ltv.tv_usec = ts.tv_nsec / 1000;
16702 			log.u_bbr.lt_epoch = tcp_tv_to_usectick(&ltv);
16703 		} else if (m->m_flags & M_TSTMP_LRO) {
16704 			/* Record the LRO the arrival timestamp */
16705 			mbuf_tstmp2timespec(m, &ts);
16706 			ltv.tv_sec = ts.tv_sec;
16707 			ltv.tv_usec = ts.tv_nsec / 1000;
16708 			log.u_bbr.flex5 = tcp_tv_to_usectick(&ltv);
16709 		}
16710 		log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
16711 		/* Log the rcv time */
16712 		log.u_bbr.delRate = m->m_pkthdr.rcv_tstmp;
16713 #ifdef TCP_REQUEST_TRK
16714 		log.u_bbr.applimited = tp->t_http_closed;
16715 		log.u_bbr.applimited <<= 8;
16716 		log.u_bbr.applimited |= tp->t_http_open;
16717 		log.u_bbr.applimited <<= 8;
16718 		log.u_bbr.applimited |= tp->t_http_req;
16719 		if (http_req) {
16720 			/* Copy out any client req info */
16721 			/* seconds */
16722 			log.u_bbr.pkt_epoch = (http_req->localtime / HPTS_USEC_IN_SEC);
16723 			/* useconds */
16724 			log.u_bbr.delivered = (http_req->localtime % HPTS_USEC_IN_SEC);
16725 			log.u_bbr.rttProp = http_req->timestamp;
16726 			log.u_bbr.cur_del_rate = http_req->start;
16727 			if (http_req->flags & TCP_HTTP_TRACK_FLG_OPEN) {
16728 				log.u_bbr.flex8 |= 1;
16729 			} else {
16730 				log.u_bbr.flex8 |= 2;
16731 				log.u_bbr.bw_inuse = http_req->end;
16732 			}
16733 			log.u_bbr.flex6 = http_req->start_seq;
16734 			if (http_req->flags & TCP_HTTP_TRACK_FLG_COMP) {
16735 				log.u_bbr.flex8 |= 4;
16736 				log.u_bbr.epoch = http_req->end_seq;
16737 			}
16738 		}
16739 #endif
16740 		TCP_LOG_EVENTP(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_IN, 0,
16741 		    tlen, &log, true, &ltv);
16742 	}
16743 	/* Remove ack required flag if set, we have one  */
16744 	if (thflags & TH_ACK)
16745 		rack->rc_ack_required = 0;
16746 	if (rack->sack_attack_disable > 0) {
16747 		rack->r_ctl.ack_during_sd++;
16748 		rack_log_type_bbrsnd(rack, 0, 0, cts, tv, __LINE__);
16749 	}
16750 	if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) {
16751 		way_out = 4;
16752 		retval = 0;
16753 		m_freem(m);
16754 		goto done_with_input;
16755 	}
16756 	/*
16757 	 * If a segment with the ACK-bit set arrives in the SYN-SENT state
16758 	 * check SEQ.ACK first as described on page 66 of RFC 793, section 3.9.
16759 	 */
16760 	if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) &&
16761 	    (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) {
16762 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
16763 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
16764 #ifdef TCP_ACCOUNTING
16765 		sched_unpin();
16766 #endif
16767 		return (1);
16768 	}
16769 	/*
16770 	 * If timestamps were negotiated during SYN/ACK and a
16771 	 * segment without a timestamp is received, silently drop
16772 	 * the segment, unless it is a RST segment or missing timestamps are
16773 	 * tolerated.
16774 	 * See section 3.2 of RFC 7323.
16775 	 */
16776 	if ((tp->t_flags & TF_RCVD_TSTMP) && !(to.to_flags & TOF_TS) &&
16777 	    ((thflags & TH_RST) == 0) && (V_tcp_tolerate_missing_ts == 0)) {
16778 		way_out = 5;
16779 		retval = 0;
16780 		m_freem(m);
16781 		goto done_with_input;
16782 	}
16783 
16784 	/*
16785 	 * Segment received on connection. Reset idle time and keep-alive
16786 	 * timer. XXX: This should be done after segment validation to
16787 	 * ignore broken/spoofed segs.
16788 	 */
16789 	if  (tp->t_idle_reduce &&
16790 	     (tp->snd_max == tp->snd_una) &&
16791 	     (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
16792 		counter_u64_add(rack_input_idle_reduces, 1);
16793 		rack_cc_after_idle(rack, tp);
16794 	}
16795 	tp->t_rcvtime = ticks;
16796 #ifdef STATS
16797 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_FRWIN, tiwin);
16798 #endif
16799 	if (tiwin > rack->r_ctl.rc_high_rwnd)
16800 		rack->r_ctl.rc_high_rwnd = tiwin;
16801 	/*
16802 	 * TCP ECN processing. XXXJTL: If we ever use ECN, we need to move
16803 	 * this to occur after we've validated the segment.
16804 	 */
16805 	if (tcp_ecn_input_segment(tp, thflags, tlen,
16806 	    tcp_packets_this_ack(tp, th->th_ack),
16807 	    iptos))
16808 		rack_cong_signal(tp, CC_ECN, th->th_ack, __LINE__);
16809 
16810 	/*
16811 	 * If echoed timestamp is later than the current time, fall back to
16812 	 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
16813 	 * were used when this connection was established.
16814 	 */
16815 	if ((to.to_flags & TOF_TS) && (to.to_tsecr != 0)) {
16816 		to.to_tsecr -= tp->ts_offset;
16817 		if (TSTMP_GT(to.to_tsecr, ms_cts))
16818 			to.to_tsecr = 0;
16819 	}
16820 
16821 	/*
16822 	 * If its the first time in we need to take care of options and
16823 	 * verify we can do SACK for rack!
16824 	 */
16825 	if (rack->r_state == 0) {
16826 		/* Should be init'd by rack_init() */
16827 		KASSERT(rack->rc_inp != NULL,
16828 		    ("%s: rack->rc_inp unexpectedly NULL", __func__));
16829 		if (rack->rc_inp == NULL) {
16830 			rack->rc_inp = inp;
16831 		}
16832 
16833 		/*
16834 		 * Process options only when we get SYN/ACK back. The SYN
16835 		 * case for incoming connections is handled in tcp_syncache.
16836 		 * According to RFC1323 the window field in a SYN (i.e., a
16837 		 * <SYN> or <SYN,ACK>) segment itself is never scaled. XXX
16838 		 * this is traditional behavior, may need to be cleaned up.
16839 		 */
16840 		if (tp->t_state == TCPS_SYN_SENT && (thflags & TH_SYN)) {
16841 			/* Handle parallel SYN for ECN */
16842 			tcp_ecn_input_parallel_syn(tp, thflags, iptos);
16843 			if ((to.to_flags & TOF_SCALE) &&
16844 			    (tp->t_flags & TF_REQ_SCALE)) {
16845 				tp->t_flags |= TF_RCVD_SCALE;
16846 				tp->snd_scale = to.to_wscale;
16847 			} else
16848 				tp->t_flags &= ~TF_REQ_SCALE;
16849 			/*
16850 			 * Initial send window.  It will be updated with the
16851 			 * next incoming segment to the scaled value.
16852 			 */
16853 			tp->snd_wnd = th->th_win;
16854 			rack_validate_fo_sendwin_up(tp, rack);
16855 			if ((to.to_flags & TOF_TS) &&
16856 			    (tp->t_flags & TF_REQ_TSTMP)) {
16857 				tp->t_flags |= TF_RCVD_TSTMP;
16858 				tp->ts_recent = to.to_tsval;
16859 				tp->ts_recent_age = cts;
16860 			} else
16861 				tp->t_flags &= ~TF_REQ_TSTMP;
16862 			if (to.to_flags & TOF_MSS) {
16863 				tcp_mss(tp, to.to_mss);
16864 			}
16865 			if ((tp->t_flags & TF_SACK_PERMIT) &&
16866 			    (to.to_flags & TOF_SACKPERM) == 0)
16867 				tp->t_flags &= ~TF_SACK_PERMIT;
16868 			if (IS_FASTOPEN(tp->t_flags)) {
16869 				if (to.to_flags & TOF_FASTOPEN) {
16870 					uint16_t mss;
16871 
16872 					if (to.to_flags & TOF_MSS)
16873 						mss = to.to_mss;
16874 					else
16875 						if ((inp->inp_vflag & INP_IPV6) != 0)
16876 							mss = TCP6_MSS;
16877 						else
16878 							mss = TCP_MSS;
16879 					tcp_fastopen_update_cache(tp, mss,
16880 					    to.to_tfo_len, to.to_tfo_cookie);
16881 				} else
16882 					tcp_fastopen_disable_path(tp);
16883 			}
16884 		}
16885 		/*
16886 		 * At this point we are at the initial call. Here we decide
16887 		 * if we are doing RACK or not. We do this by seeing if
16888 		 * TF_SACK_PERMIT is set and the sack-not-required is clear.
16889 		 * The code now does do dup-ack counting so if you don't
16890 		 * switch back you won't get rack & TLP, but you will still
16891 		 * get this stack.
16892 		 */
16893 
16894 		if ((rack_sack_not_required == 0) &&
16895 		    ((tp->t_flags & TF_SACK_PERMIT) == 0)) {
16896 			tcp_switch_back_to_default(tp);
16897 			(*tp->t_fb->tfb_tcp_do_segment)(tp, m, th, drop_hdrlen,
16898 			    tlen, iptos);
16899 #ifdef TCP_ACCOUNTING
16900 			sched_unpin();
16901 #endif
16902 			return (1);
16903 		}
16904 		tcp_set_hpts(tp);
16905 		sack_filter_clear(&rack->r_ctl.rack_sf, th->th_ack);
16906 	}
16907 	if (thflags & TH_FIN)
16908 		tcp_log_end_status(tp, TCP_EI_STATUS_CLIENT_FIN);
16909 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
16910 	if ((rack->rc_gp_dyn_mul) &&
16911 	    (rack->use_fixed_rate == 0) &&
16912 	    (rack->rc_always_pace)) {
16913 		/* Check in on probertt */
16914 		rack_check_probe_rtt(rack, us_cts);
16915 	}
16916 	rack_clear_rate_sample(rack);
16917 	if ((rack->forced_ack) &&
16918 	    ((tcp_get_flags(th) & TH_RST) == 0)) {
16919 		rack_handle_probe_response(rack, tiwin, us_cts);
16920 	}
16921 	/*
16922 	 * This is the one exception case where we set the rack state
16923 	 * always. All other times (timers etc) we must have a rack-state
16924 	 * set (so we assure we have done the checks above for SACK).
16925 	 */
16926 	rack->r_ctl.rc_rcvtime = cts;
16927 	if (rack->r_state != tp->t_state)
16928 		rack_set_state(tp, rack);
16929 	if (SEQ_GT(th->th_ack, tp->snd_una) &&
16930 	    (rsm = tqhash_min(rack->r_ctl.tqh)) != NULL)
16931 		kern_prefetch(rsm, &prev_state);
16932 	prev_state = rack->r_state;
16933 	if ((thflags & TH_RST) &&
16934 	    ((SEQ_GEQ(th->th_seq, tp->last_ack_sent) &&
16935 	      SEQ_LT(th->th_seq, tp->last_ack_sent + tp->rcv_wnd)) ||
16936 	     (tp->rcv_wnd == 0 && tp->last_ack_sent == th->th_seq))) {
16937 		/* The connection will be killed by a reset check the tracepoint */
16938 		tcp_trace_point(rack->rc_tp, TCP_TP_RESET_RCV);
16939 	}
16940 	retval = (*rack->r_substate) (m, th, so,
16941 	    tp, &to, drop_hdrlen,
16942 	    tlen, tiwin, thflags, nxt_pkt, iptos);
16943 	if (retval == 0) {
16944 		/*
16945 		 * If retval is 1 the tcb is unlocked and most likely the tp
16946 		 * is gone.
16947 		 */
16948 		INP_WLOCK_ASSERT(inp);
16949 		if ((rack->rc_gp_dyn_mul) &&
16950 		    (rack->rc_always_pace) &&
16951 		    (rack->use_fixed_rate == 0) &&
16952 		    rack->in_probe_rtt &&
16953 		    (rack->r_ctl.rc_time_probertt_starts == 0)) {
16954 			/*
16955 			 * If we are going for target, lets recheck before
16956 			 * we output.
16957 			 */
16958 			rack_check_probe_rtt(rack, us_cts);
16959 		}
16960 		if (rack->set_pacing_done_a_iw == 0) {
16961 			/* How much has been acked? */
16962 			if ((tp->snd_una - tp->iss) > (ctf_fixed_maxseg(tp) * 10)) {
16963 				/* We have enough to set in the pacing segment size */
16964 				rack->set_pacing_done_a_iw = 1;
16965 				rack_set_pace_segments(tp, rack, __LINE__, NULL);
16966 			}
16967 		}
16968 		tcp_rack_xmit_timer_commit(rack, tp);
16969 #ifdef TCP_ACCOUNTING
16970 		/*
16971 		 * If we set the ack_val_se to what ack processing we are doing
16972 		 * we also want to track how many cycles we burned. Note
16973 		 * the bits after tcp_output we let be "free". This is because
16974 		 * we are also tracking the tcp_output times as well. Note the
16975 		 * use of 0xf here since we only have 11 counter (0 - 0xa) and
16976 		 * 0xf cannot be returned and is what we initialize it too to
16977 		 * indicate we are not doing the tabulations.
16978 		 */
16979 		if (ack_val_set != 0xf) {
16980 			uint64_t crtsc;
16981 
16982 			crtsc = get_cyclecount();
16983 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16984 				tp->tcp_proc_time[ack_val_set] += (crtsc - ts_val);
16985 			}
16986 		}
16987 #endif
16988 		if ((nxt_pkt == 0) && (no_output == 0)) {
16989 			if ((rack->r_wanted_output != 0) || (rack->r_fast_output != 0)) {
16990 do_output_now:
16991 				if (tcp_output(tp) < 0) {
16992 #ifdef TCP_ACCOUNTING
16993 					sched_unpin();
16994 #endif
16995 					return (1);
16996 				}
16997 				did_out = 1;
16998 			}
16999 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
17000 			rack_free_trim(rack);
17001 		} else if ((no_output == 1) &&
17002 			   (nxt_pkt == 0)  &&
17003 			   (tcp_in_hpts(rack->rc_tp) == 0)) {
17004 			/*
17005 			 * We are not in hpts and we had a pacing timer up. Use
17006 			 * the remaining time (slot_remaining) to restart the timer.
17007 			 */
17008 			KASSERT ((slot_remaining != 0), ("slot remaining is zero for rack:%p tp:%p", rack, tp));
17009 			rack_start_hpts_timer(rack, tp, cts, slot_remaining, 0, 0);
17010 			rack_free_trim(rack);
17011 		}
17012 		/* Clear the flag, it may have been cleared by output but we may not have  */
17013 		if ((nxt_pkt == 0) && (tp->t_flags2 & TF2_HPTS_CALLS))
17014 			tp->t_flags2 &= ~TF2_HPTS_CALLS;
17015 		/* Update any rounds needed */
17016 		if (rack_verbose_logging &&  tcp_bblogging_on(rack->rc_tp))
17017 			rack_log_hystart_event(rack, high_seq, 8);
17018 		/*
17019 		 * The draft (v3) calls for us to use SEQ_GEQ, but that
17020 		 * causes issues when we are just going app limited. Lets
17021 		 * instead use SEQ_GT <or> where its equal but more data
17022 		 * is outstanding.
17023 		 *
17024 		 * Also make sure we are on the last ack of a series. We
17025 		 * have to have all the ack's processed in queue to know
17026 		 * if there is something left outstanding.
17027 		 */
17028 		if (SEQ_GEQ(tp->snd_una, rack->r_ctl.roundends) &&
17029 		    (rack->rc_new_rnd_needed == 0) &&
17030 		    (nxt_pkt == 0)) {
17031 			rack_log_hystart_event(rack, tp->snd_una, 21);
17032 			rack->r_ctl.current_round++;
17033 			/* Force the next send to setup the next round */
17034 			rack->rc_new_rnd_needed = 1;
17035 			if (CC_ALGO(tp)->newround != NULL) {
17036 				CC_ALGO(tp)->newround(&tp->t_ccv, rack->r_ctl.current_round);
17037 			}
17038 		}
17039 		if ((nxt_pkt == 0) &&
17040 		    ((rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) == 0) &&
17041 		    (SEQ_GT(tp->snd_max, tp->snd_una) ||
17042 		     (tp->t_flags & TF_DELACK) ||
17043 		     ((V_tcp_always_keepalive || rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
17044 		      (tp->t_state <= TCPS_CLOSING)))) {
17045 			/* We could not send (probably in the hpts but stopped the timer earlier)? */
17046 			if ((tp->snd_max == tp->snd_una) &&
17047 			    ((tp->t_flags & TF_DELACK) == 0) &&
17048 			    (tcp_in_hpts(rack->rc_tp)) &&
17049 			    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
17050 				/* keep alive not needed if we are hptsi output yet */
17051 				;
17052 			} else {
17053 				int late = 0;
17054 				if (tcp_in_hpts(tp)) {
17055 					if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
17056 						us_cts = tcp_get_usecs(NULL);
17057 						if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
17058 							rack->r_early = 1;
17059 							rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
17060 						} else
17061 							late = 1;
17062 						rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
17063 					}
17064 					tcp_hpts_remove(tp);
17065 				}
17066 				if (late && (did_out == 0)) {
17067 					/*
17068 					 * We are late in the sending
17069 					 * and we did not call the output
17070 					 * (this probably should not happen).
17071 					 */
17072 					goto do_output_now;
17073 				}
17074 				rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
17075 			}
17076 			way_out = 1;
17077 		} else if (nxt_pkt == 0) {
17078 			/* Do we have the correct timer running? */
17079 			rack_timer_audit(tp, rack, &so->so_snd);
17080 			way_out = 2;
17081 		}
17082 	done_with_input:
17083 		rack_log_doseg_done(rack, cts, nxt_pkt, did_out, way_out, max(1, nsegs));
17084 		if (did_out)
17085 			rack->r_wanted_output = 0;
17086 	}
17087 #ifdef TCP_ACCOUNTING
17088 	sched_unpin();
17089 #endif
17090 	return (retval);
17091 }
17092 
17093 static void
17094 rack_do_segment(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
17095     int32_t drop_hdrlen, int32_t tlen, uint8_t iptos)
17096 {
17097 	struct timeval tv;
17098 
17099 	/* First lets see if we have old packets */
17100 	if (!STAILQ_EMPTY(&tp->t_inqueue)) {
17101 		if (ctf_do_queued_segments(tp, 1)) {
17102 			m_freem(m);
17103 			return;
17104 		}
17105 	}
17106 	if (m->m_flags & M_TSTMP_LRO) {
17107 		mbuf_tstmp2timeval(m, &tv);
17108 	} else {
17109 		/* Should not be should we kassert instead? */
17110 		tcp_get_usecs(&tv);
17111 	}
17112 	if (rack_do_segment_nounlock(tp, m, th, drop_hdrlen, tlen, iptos, 0,
17113 	    &tv) == 0) {
17114 		INP_WUNLOCK(tptoinpcb(tp));
17115 	}
17116 }
17117 
17118 struct rack_sendmap *
17119 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack, uint32_t tsused)
17120 {
17121 	struct rack_sendmap *rsm = NULL;
17122 	int32_t idx;
17123 	uint32_t srtt = 0, thresh = 0, ts_low = 0;
17124 	int no_sack = 0;
17125 
17126 	/* Return the next guy to be re-transmitted */
17127 	if (tqhash_empty(rack->r_ctl.tqh)) {
17128 		return (NULL);
17129 	}
17130 	if (tp->t_flags & TF_SENTFIN) {
17131 		/* retran the end FIN? */
17132 		return (NULL);
17133 	}
17134 	/* ok lets look at this one */
17135 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
17136 	if (rack->r_must_retran && rsm && (rsm->r_flags & RACK_MUST_RXT)) {
17137 		return (rsm);
17138 	}
17139 	if (rsm && ((rsm->r_flags & RACK_ACKED) == 0)) {
17140 		goto check_it;
17141 	}
17142 	rsm = rack_find_lowest_rsm(rack);
17143 	if (rsm == NULL) {
17144 		return (NULL);
17145 	}
17146 check_it:
17147 	if (((rack->rc_tp->t_flags & TF_SACK_PERMIT) == 0) ||
17148 	    (rack->sack_attack_disable > 0)) {
17149 		no_sack = 1;
17150 	}
17151 	if ((no_sack > 0) &&
17152 	    (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
17153 		/*
17154 		 * No sack so we automatically do the 3 strikes and
17155 		 * retransmit (no rack timer would be started).
17156 		 */
17157 		return (rsm);
17158 	}
17159 	if (rsm->r_flags & RACK_ACKED) {
17160 		return (NULL);
17161 	}
17162 	if (((rsm->r_flags & RACK_SACK_PASSED) == 0) &&
17163 	    (rsm->r_dupack < DUP_ACK_THRESHOLD)) {
17164 		/* Its not yet ready */
17165 		return (NULL);
17166 	}
17167 	srtt = rack_grab_rtt(tp, rack);
17168 	idx = rsm->r_rtr_cnt - 1;
17169 	ts_low = (uint32_t)rsm->r_tim_lastsent[idx];
17170 	thresh = rack_calc_thresh_rack(rack, srtt, tsused);
17171 	if ((tsused == ts_low) ||
17172 	    (TSTMP_LT(tsused, ts_low))) {
17173 		/* No time since sending */
17174 		return (NULL);
17175 	}
17176 	if ((tsused - ts_low) < thresh) {
17177 		/* It has not been long enough yet */
17178 		return (NULL);
17179 	}
17180 	if ((rsm->r_dupack >= DUP_ACK_THRESHOLD) ||
17181 	    ((rsm->r_flags & RACK_SACK_PASSED) &&
17182 	     (rack->sack_attack_disable == 0))) {
17183 		/*
17184 		 * We have passed the dup-ack threshold <or>
17185 		 * a SACK has indicated this is missing.
17186 		 * Note that if you are a declared attacker
17187 		 * it is only the dup-ack threshold that
17188 		 * will cause retransmits.
17189 		 */
17190 		/* log retransmit reason */
17191 		rack_log_retran_reason(rack, rsm, (tsused - ts_low), thresh, 1);
17192 		rack->r_fast_output = 0;
17193 		return (rsm);
17194 	}
17195 	return (NULL);
17196 }
17197 
17198 static void
17199 rack_log_pacing_delay_calc(struct tcp_rack *rack, uint32_t len, uint32_t slot,
17200 			   uint64_t bw_est, uint64_t bw, uint64_t len_time, int method,
17201 			   int line, struct rack_sendmap *rsm, uint8_t quality)
17202 {
17203 	if (tcp_bblogging_on(rack->rc_tp)) {
17204 		union tcp_log_stackspecific log;
17205 		struct timeval tv;
17206 
17207 		memset(&log, 0, sizeof(log));
17208 		log.u_bbr.flex1 = slot;
17209 		log.u_bbr.flex2 = len;
17210 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_min_segs;
17211 		log.u_bbr.flex4 = rack->r_ctl.rc_pace_max_segs;
17212 		log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ss;
17213 		log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_ca;
17214 		log.u_bbr.use_lt_bw = rack->rc_ack_can_sendout_data;
17215 		log.u_bbr.use_lt_bw <<= 1;
17216 		log.u_bbr.use_lt_bw |= rack->r_late;
17217 		log.u_bbr.use_lt_bw <<= 1;
17218 		log.u_bbr.use_lt_bw |= rack->r_early;
17219 		log.u_bbr.use_lt_bw <<= 1;
17220 		log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
17221 		log.u_bbr.use_lt_bw <<= 1;
17222 		log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
17223 		log.u_bbr.use_lt_bw <<= 1;
17224 		log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
17225 		log.u_bbr.use_lt_bw <<= 1;
17226 		log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
17227 		log.u_bbr.use_lt_bw <<= 1;
17228 		log.u_bbr.use_lt_bw |= rack->gp_ready;
17229 		log.u_bbr.pkt_epoch = line;
17230 		log.u_bbr.epoch = rack->r_ctl.rc_agg_delayed;
17231 		log.u_bbr.lt_epoch = rack->r_ctl.rc_agg_early;
17232 		log.u_bbr.applimited = rack->r_ctl.rack_per_of_gp_rec;
17233 		log.u_bbr.bw_inuse = bw_est;
17234 		log.u_bbr.delRate = bw;
17235 		if (rack->r_ctl.gp_bw == 0)
17236 			log.u_bbr.cur_del_rate = 0;
17237 		else
17238 			log.u_bbr.cur_del_rate = rack_get_bw(rack);
17239 		log.u_bbr.rttProp = len_time;
17240 		log.u_bbr.pkts_out = rack->r_ctl.rc_rack_min_rtt;
17241 		log.u_bbr.lost = rack->r_ctl.rc_probertt_sndmax_atexit;
17242 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
17243 		if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh) {
17244 			/* We are in slow start */
17245 			log.u_bbr.flex7 = 1;
17246 		} else {
17247 			/* we are on congestion avoidance */
17248 			log.u_bbr.flex7 = 0;
17249 		}
17250 		log.u_bbr.flex8 = method;
17251 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
17252 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
17253 		log.u_bbr.cwnd_gain = rack->rc_gp_saw_rec;
17254 		log.u_bbr.cwnd_gain <<= 1;
17255 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
17256 		log.u_bbr.cwnd_gain <<= 1;
17257 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
17258 		log.u_bbr.bbr_substate = quality;
17259 		log.u_bbr.bbr_state = rack->dgp_on;
17260 		log.u_bbr.bbr_state <<= 1;
17261 		log.u_bbr.bbr_state |= rack->r_fill_less_agg;
17262 		log.u_bbr.bbr_state <<= 1;
17263 		log.u_bbr.bbr_state |= rack->rc_pace_to_cwnd;
17264 		log.u_bbr.bbr_state <<= 2;
17265 		log.u_bbr.bbr_state |= rack->r_pacing_discount;
17266 		log.u_bbr.flex7 = ((rack->r_ctl.pacing_discount_amm << 1) | log.u_bbr.flex7);
17267 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
17268 		    &rack->rc_inp->inp_socket->so_rcv,
17269 		    &rack->rc_inp->inp_socket->so_snd,
17270 		    BBR_LOG_HPTSI_CALC, 0,
17271 		    0, &log, false, &tv);
17272 	}
17273 }
17274 
17275 static uint32_t
17276 rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss)
17277 {
17278 	uint32_t new_tso, user_max, pace_one;
17279 
17280 	user_max = rack->rc_user_set_max_segs * mss;
17281 	if (rack->rc_force_max_seg) {
17282 		return (user_max);
17283 	}
17284 	if (rack->use_fixed_rate &&
17285 	    ((rack->r_ctl.crte == NULL) ||
17286 	     (bw != rack->r_ctl.crte->rate))) {
17287 		/* Use the user mss since we are not exactly matched */
17288 		return (user_max);
17289 	}
17290 	if (rack_pace_one_seg ||
17291 	    (rack->r_ctl.rc_user_set_min_segs == 1))
17292 		pace_one = 1;
17293 	else
17294 		pace_one = 0;
17295 
17296 	new_tso = tcp_get_pacing_burst_size_w_divisor(rack->rc_tp, bw, mss,
17297 		     pace_one, rack->r_ctl.crte, NULL, rack->r_ctl.pace_len_divisor);
17298 	if (new_tso > user_max)
17299 		new_tso = user_max;
17300 	if (rack->rc_hybrid_mode && rack->r_ctl.client_suggested_maxseg) {
17301 		if (((uint32_t)rack->r_ctl.client_suggested_maxseg * mss) > new_tso)
17302 			new_tso = (uint32_t)rack->r_ctl.client_suggested_maxseg * mss;
17303 	}
17304 	if (rack->r_ctl.rc_user_set_min_segs &&
17305 	    ((rack->r_ctl.rc_user_set_min_segs * mss) > new_tso))
17306 	    new_tso = rack->r_ctl.rc_user_set_min_segs * mss;
17307 	return (new_tso);
17308 }
17309 
17310 static int32_t
17311 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)
17312 {
17313 	uint64_t lentim, fill_bw;
17314 
17315 	/* Lets first see if we are full, if so continue with normal rate */
17316 	rack->r_via_fill_cw = 0;
17317 	if (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.cwnd_to_use)
17318 		return (slot);
17319 	if ((ctf_outstanding(rack->rc_tp) + (segsiz-1)) > rack->rc_tp->snd_wnd)
17320 		return (slot);
17321 	if (rack->r_ctl.rc_last_us_rtt == 0)
17322 		return (slot);
17323 	if (rack->rc_pace_fill_if_rttin_range &&
17324 	    (rack->r_ctl.rc_last_us_rtt >=
17325 	     (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack->rtt_limit_mul))) {
17326 		/* The rtt is huge, N * smallest, lets not fill */
17327 		return (slot);
17328 	}
17329 	/*
17330 	 * first lets calculate the b/w based on the last us-rtt
17331 	 * and the the smallest send window.
17332 	 */
17333 	fill_bw = min(rack->rc_tp->snd_cwnd, rack->r_ctl.cwnd_to_use);
17334 	/* Take the rwnd if its smaller */
17335 	if (fill_bw > rack->rc_tp->snd_wnd)
17336 		fill_bw = rack->rc_tp->snd_wnd;
17337 	/* Now lets make it into a b/w */
17338 	fill_bw *= (uint64_t)HPTS_USEC_IN_SEC;
17339 	fill_bw /= (uint64_t)rack->r_ctl.rc_last_us_rtt;
17340 	if (rack->r_fill_less_agg) {
17341 		/*
17342 		 * We want the average of the rate_wanted
17343 		 * and our fill-cw calculated bw. We also want
17344 		 * to cap any increase to be no more than
17345 		 * X times the lt_bw (where X is the rack_bw_multipler).
17346 		 */
17347 		uint64_t lt_bw, rate;
17348 
17349 		lt_bw = rack_get_lt_bw(rack);
17350 		if (lt_bw > *rate_wanted)
17351 			rate = lt_bw;
17352 		else
17353 			rate = *rate_wanted;
17354 		fill_bw += rate;
17355 		fill_bw /= 2;
17356 		if (rack_bw_multipler && (fill_bw > (rate * rack_bw_multipler))) {
17357 			fill_bw = rate * rack_bw_multipler;
17358 		}
17359 	}
17360 	/* We are below the min b/w */
17361 	if (non_paced)
17362 		*rate_wanted = fill_bw;
17363 	if ((fill_bw < RACK_MIN_BW) || (fill_bw < *rate_wanted))
17364 		return (slot);
17365 	rack->r_via_fill_cw = 1;
17366 	if (rack->r_rack_hw_rate_caps &&
17367 	    (rack->r_ctl.crte != NULL)) {
17368 		uint64_t high_rate;
17369 
17370 		high_rate = tcp_hw_highest_rate(rack->r_ctl.crte);
17371 		if (fill_bw > high_rate) {
17372 			/* We are capping bw at the highest rate table entry */
17373 			if (*rate_wanted > high_rate) {
17374 				/* The original rate was also capped */
17375 				rack->r_via_fill_cw = 0;
17376 			}
17377 			rack_log_hdwr_pacing(rack,
17378 					     fill_bw, high_rate, __LINE__,
17379 					     0, 3);
17380 			fill_bw = high_rate;
17381 			if (capped)
17382 				*capped = 1;
17383 		}
17384 	} else if ((rack->r_ctl.crte == NULL) &&
17385 		   (rack->rack_hdrw_pacing == 0) &&
17386 		   (rack->rack_hdw_pace_ena) &&
17387 		   rack->r_rack_hw_rate_caps &&
17388 		   (rack->rack_attempt_hdwr_pace == 0) &&
17389 		   (rack->rc_inp->inp_route.ro_nh != NULL) &&
17390 		   (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
17391 		/*
17392 		 * Ok we may have a first attempt that is greater than our top rate
17393 		 * lets check.
17394 		 */
17395 		uint64_t high_rate;
17396 
17397 		high_rate = tcp_hw_highest_rate_ifp(rack->rc_inp->inp_route.ro_nh->nh_ifp, rack->rc_inp);
17398 		if (high_rate) {
17399 			if (fill_bw > high_rate) {
17400 				fill_bw = high_rate;
17401 				if (capped)
17402 					*capped = 1;
17403 			}
17404 		}
17405 	}
17406 	if (rack->r_ctl.bw_rate_cap && (fill_bw > rack->r_ctl.bw_rate_cap)) {
17407 		rack_log_hybrid_bw(rack, rack->rc_tp->snd_max,
17408 				   fill_bw, 0, 0, HYBRID_LOG_RATE_CAP, 2, NULL);
17409 		fill_bw = rack->r_ctl.bw_rate_cap;
17410 	}
17411 	/*
17412 	 * Ok fill_bw holds our mythical b/w to fill the cwnd
17413 	 * in an rtt (unless it was capped), what does that
17414 	 * time wise equate too?
17415 	 */
17416 	lentim = (uint64_t)(len) * (uint64_t)HPTS_USEC_IN_SEC;
17417 	lentim /= fill_bw;
17418 	*rate_wanted = fill_bw;
17419 	if (non_paced || (lentim < slot)) {
17420 		rack_log_pacing_delay_calc(rack, len, slot, fill_bw,
17421 					   0, lentim, 12, __LINE__, NULL, 0);
17422 		return ((int32_t)lentim);
17423 	} else
17424 		return (slot);
17425 }
17426 
17427 static int32_t
17428 rack_get_pacing_delay(struct tcp_rack *rack, struct tcpcb *tp, uint32_t len, struct rack_sendmap *rsm, uint32_t segsiz)
17429 {
17430 	uint64_t srtt;
17431 	int32_t slot = 0;
17432 	int32_t minslot = 0;
17433 	int can_start_hw_pacing = 1;
17434 	int err;
17435 	int pace_one;
17436 
17437 	if (rack_pace_one_seg ||
17438 	    (rack->r_ctl.rc_user_set_min_segs == 1))
17439 		pace_one = 1;
17440 	else
17441 		pace_one = 0;
17442 	if (rack->rc_always_pace == 0) {
17443 		/*
17444 		 * We use the most optimistic possible cwnd/srtt for
17445 		 * sending calculations. This will make our
17446 		 * calculation anticipate getting more through
17447 		 * quicker then possible. But thats ok we don't want
17448 		 * the peer to have a gap in data sending.
17449 		 */
17450 		uint64_t cwnd, tr_perms = 0;
17451 		int32_t reduce = 0;
17452 
17453 	old_method:
17454 		/*
17455 		 * We keep no precise pacing with the old method
17456 		 * instead we use the pacer to mitigate bursts.
17457 		 */
17458 		if (rack->r_ctl.rc_rack_min_rtt)
17459 			srtt = rack->r_ctl.rc_rack_min_rtt;
17460 		else
17461 			srtt = max(tp->t_srtt, 1);
17462 		if (rack->r_ctl.rc_rack_largest_cwnd)
17463 			cwnd = rack->r_ctl.rc_rack_largest_cwnd;
17464 		else
17465 			cwnd = rack->r_ctl.cwnd_to_use;
17466 		/* Inflate cwnd by 1000 so srtt of usecs is in ms */
17467 		tr_perms = (cwnd * 1000) / srtt;
17468 		if (tr_perms == 0) {
17469 			tr_perms = ctf_fixed_maxseg(tp);
17470 		}
17471 		/*
17472 		 * Calculate how long this will take to drain, if
17473 		 * the calculation comes out to zero, thats ok we
17474 		 * will use send_a_lot to possibly spin around for
17475 		 * more increasing tot_len_this_send to the point
17476 		 * that its going to require a pace, or we hit the
17477 		 * cwnd. Which in that case we are just waiting for
17478 		 * a ACK.
17479 		 */
17480 		slot = len / tr_perms;
17481 		/* Now do we reduce the time so we don't run dry? */
17482 		if (slot && rack_slot_reduction) {
17483 			reduce = (slot / rack_slot_reduction);
17484 			if (reduce < slot) {
17485 				slot -= reduce;
17486 			} else
17487 				slot = 0;
17488 		}
17489 		slot *= HPTS_USEC_IN_MSEC;
17490 		if (rack->rc_pace_to_cwnd) {
17491 			uint64_t rate_wanted = 0;
17492 
17493 			slot = pace_to_fill_cwnd(rack, slot, len, segsiz, NULL, &rate_wanted, 1);
17494 			rack->rc_ack_can_sendout_data = 1;
17495 			rack_log_pacing_delay_calc(rack, len, slot, rate_wanted, 0, 0, 14, __LINE__, NULL, 0);
17496 		} else
17497 			rack_log_pacing_delay_calc(rack, len, slot, tr_perms, reduce, 0, 7, __LINE__, NULL, 0);
17498 		/*******************************************************/
17499 		/* RRS: We insert non-paced call to stats here for len */
17500 		/*******************************************************/
17501 	} else {
17502 		uint64_t bw_est, res, lentim, rate_wanted;
17503 		uint32_t segs, oh;
17504 		int capped = 0;
17505 		int prev_fill;
17506 
17507 		if ((rack->r_rr_config == 1) && rsm) {
17508 			return (rack->r_ctl.rc_min_to);
17509 		}
17510 		if (rack->use_fixed_rate) {
17511 			rate_wanted = bw_est = rack_get_fixed_pacing_bw(rack);
17512 		} else if ((rack->r_ctl.init_rate == 0) &&
17513 			   (rack->r_ctl.gp_bw == 0)) {
17514 			/* no way to yet do an estimate */
17515 			bw_est = rate_wanted = 0;
17516 		} else {
17517 			bw_est = rack_get_bw(rack);
17518 			rate_wanted = rack_get_output_bw(rack, bw_est, rsm, &capped);
17519 		}
17520 		if ((bw_est == 0) || (rate_wanted == 0) ||
17521 		    ((rack->gp_ready == 0) && (rack->use_fixed_rate == 0))) {
17522 			/*
17523 			 * No way yet to make a b/w estimate or
17524 			 * our raise is set incorrectly.
17525 			 */
17526 			goto old_method;
17527 		}
17528 		rack_rate_cap_bw(rack, &rate_wanted, &capped);
17529 		/* We need to account for all the overheads */
17530 		segs = (len + segsiz - 1) / segsiz;
17531 		/*
17532 		 * We need the diff between 1514 bytes (e-mtu with e-hdr)
17533 		 * and how much data we put in each packet. Yes this
17534 		 * means we may be off if we are larger than 1500 bytes
17535 		 * or smaller. But this just makes us more conservative.
17536 		 */
17537 
17538 		oh =  (tp->t_maxseg - segsiz) + sizeof(struct tcphdr);
17539 		if (rack->r_is_v6) {
17540 #ifdef INET6
17541 			oh += sizeof(struct ip6_hdr);
17542 #endif
17543 		} else {
17544 #ifdef INET
17545 			oh += sizeof(struct ip);
17546 #endif
17547 		}
17548 		/* We add a fixed 14 for the ethernet header */
17549 		oh += 14;
17550 		segs *= oh;
17551 		lentim = (uint64_t)(len + segs) * (uint64_t)HPTS_USEC_IN_SEC;
17552 		res = lentim / rate_wanted;
17553 		slot = (uint32_t)res;
17554 		if (rack_hw_rate_min &&
17555 		    (rate_wanted < rack_hw_rate_min)) {
17556 			can_start_hw_pacing = 0;
17557 			if (rack->r_ctl.crte) {
17558 				/*
17559 				 * Ok we need to release it, we
17560 				 * have fallen too low.
17561 				 */
17562 				tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
17563 				rack->r_ctl.crte = NULL;
17564 				rack->rack_attempt_hdwr_pace = 0;
17565 				rack->rack_hdrw_pacing = 0;
17566 			}
17567 		}
17568 		if (rack->r_ctl.crte &&
17569 		    (tcp_hw_highest_rate(rack->r_ctl.crte) < rate_wanted)) {
17570 			/*
17571 			 * We want more than the hardware can give us,
17572 			 * don't start any hw pacing.
17573 			 */
17574 			can_start_hw_pacing = 0;
17575 			if (rack->r_rack_hw_rate_caps == 0) {
17576 				/*
17577 				 * Ok we need to release it, we
17578 				 * want more than the card can give us and
17579 				 * no rate cap is in place. Set it up so
17580 				 * when we want less we can retry.
17581 				 */
17582 				tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
17583 				rack->r_ctl.crte = NULL;
17584 				rack->rack_attempt_hdwr_pace = 0;
17585 				rack->rack_hdrw_pacing = 0;
17586 			}
17587 		}
17588 		if ((rack->r_ctl.crte != NULL) && (rack->rc_inp->inp_snd_tag == NULL)) {
17589 			/*
17590 			 * We lost our rate somehow, this can happen
17591 			 * if the interface changed underneath us.
17592 			 */
17593 			tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
17594 			rack->r_ctl.crte = NULL;
17595 			/* Lets re-allow attempting to setup pacing */
17596 			rack->rack_hdrw_pacing = 0;
17597 			rack->rack_attempt_hdwr_pace = 0;
17598 			rack_log_hdwr_pacing(rack,
17599 					     rate_wanted, bw_est, __LINE__,
17600 					     0, 6);
17601 		}
17602 		prev_fill = rack->r_via_fill_cw;
17603 		if ((rack->rc_pace_to_cwnd) &&
17604 		    (capped == 0) &&
17605 		    (rack->use_fixed_rate == 0) &&
17606 		    (rack->in_probe_rtt == 0) &&
17607 		    (IN_FASTRECOVERY(rack->rc_tp->t_flags) == 0)) {
17608 			/*
17609 			 * We want to pace at our rate *or* faster to
17610 			 * fill the cwnd to the max if its not full.
17611 			 */
17612 			slot = pace_to_fill_cwnd(rack, slot, (len+segs), segsiz, &capped, &rate_wanted, 0);
17613 			/* Re-check to make sure we are not exceeding our max b/w */
17614 			if ((rack->r_ctl.crte != NULL) &&
17615 			    (tcp_hw_highest_rate(rack->r_ctl.crte) < rate_wanted)) {
17616 				/*
17617 				 * We want more than the hardware can give us,
17618 				 * don't start any hw pacing.
17619 				 */
17620 				can_start_hw_pacing = 0;
17621 				if (rack->r_rack_hw_rate_caps == 0) {
17622 					/*
17623 					 * Ok we need to release it, we
17624 					 * want more than the card can give us and
17625 					 * no rate cap is in place. Set it up so
17626 					 * when we want less we can retry.
17627 					 */
17628 					tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
17629 					rack->r_ctl.crte = NULL;
17630 					rack->rack_attempt_hdwr_pace = 0;
17631 					rack->rack_hdrw_pacing = 0;
17632 					rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
17633 				}
17634 			}
17635 		}
17636 		if ((rack->rc_inp->inp_route.ro_nh != NULL) &&
17637 		    (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
17638 			if ((rack->rack_hdw_pace_ena) &&
17639 			    (can_start_hw_pacing > 0) &&
17640 			    (rack->rack_hdrw_pacing == 0) &&
17641 			    (rack->rack_attempt_hdwr_pace == 0)) {
17642 				/*
17643 				 * Lets attempt to turn on hardware pacing
17644 				 * if we can.
17645 				 */
17646 				rack->rack_attempt_hdwr_pace = 1;
17647 				rack->r_ctl.crte = tcp_set_pacing_rate(rack->rc_tp,
17648 								       rack->rc_inp->inp_route.ro_nh->nh_ifp,
17649 								       rate_wanted,
17650 								       RS_PACING_GEQ,
17651 								       &err, &rack->r_ctl.crte_prev_rate);
17652 				if (rack->r_ctl.crte) {
17653 					rack->rack_hdrw_pacing = 1;
17654 					rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size_w_divisor(tp, rate_wanted, segsiz,
17655 									  pace_one, rack->r_ctl.crte,
17656 									  NULL, rack->r_ctl.pace_len_divisor);
17657 					rack_log_hdwr_pacing(rack,
17658 							     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
17659 							     err, 0);
17660 					rack->r_ctl.last_hw_bw_req = rate_wanted;
17661 				} else {
17662 					counter_u64_add(rack_hw_pace_init_fail, 1);
17663 				}
17664 			} else if (rack->rack_hdrw_pacing &&
17665 				   (rack->r_ctl.last_hw_bw_req != rate_wanted)) {
17666 				/* Do we need to adjust our rate? */
17667 				const struct tcp_hwrate_limit_table *nrte;
17668 
17669 				if (rack->r_up_only &&
17670 				    (rate_wanted < rack->r_ctl.crte->rate)) {
17671 					/**
17672 					 * We have four possible states here
17673 					 * having to do with the previous time
17674 					 * and this time.
17675 					 *   previous  |  this-time
17676 					 * A)     0      |     0   -- fill_cw not in the picture
17677 					 * B)     1      |     0   -- we were doing a fill-cw but now are not
17678 					 * C)     1      |     1   -- all rates from fill_cw
17679 					 * D)     0      |     1   -- we were doing non-fill and now we are filling
17680 					 *
17681 					 * For case A, C and D we don't allow a drop. But for
17682 					 * case B where we now our on our steady rate we do
17683 					 * allow a drop.
17684 					 *
17685 					 */
17686 					if (!((prev_fill == 1) && (rack->r_via_fill_cw == 0)))
17687 						goto done_w_hdwr;
17688 				}
17689 				if ((rate_wanted > rack->r_ctl.crte->rate) ||
17690 				    (rate_wanted <= rack->r_ctl.crte_prev_rate)) {
17691 					if (rack_hw_rate_to_low &&
17692 					    (bw_est < rack_hw_rate_to_low)) {
17693 						/*
17694 						 * The pacing rate is too low for hardware, but
17695 						 * do allow hardware pacing to be restarted.
17696 						 */
17697 						rack_log_hdwr_pacing(rack,
17698 							     bw_est, rack->r_ctl.crte->rate, __LINE__,
17699 							     0, 5);
17700 						tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
17701 						rack->r_ctl.crte = NULL;
17702 						rack->rack_attempt_hdwr_pace = 0;
17703 						rack->rack_hdrw_pacing = 0;
17704 						rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
17705 						goto done_w_hdwr;
17706 					}
17707 					nrte = tcp_chg_pacing_rate(rack->r_ctl.crte,
17708 									    rack->rc_tp,
17709 									    rack->rc_inp->inp_route.ro_nh->nh_ifp,
17710 									    rate_wanted,
17711 									    RS_PACING_GEQ,
17712 									    &err, &rack->r_ctl.crte_prev_rate);
17713 					if (nrte == NULL) {
17714 						/*
17715 						 * Lost the rate, lets drop hardware pacing
17716 						 * period.
17717 						 */
17718 						rack->rack_hdrw_pacing = 0;
17719 						rack->r_ctl.crte = NULL;
17720 						rack_log_hdwr_pacing(rack,
17721 								     rate_wanted, 0, __LINE__,
17722 								     err, 1);
17723 						rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
17724 						counter_u64_add(rack_hw_pace_lost, 1);
17725 					} else if (nrte != rack->r_ctl.crte) {
17726 						rack->r_ctl.crte = nrte;
17727 						rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size_w_divisor(tp, rate_wanted,
17728 										 segsiz, pace_one, rack->r_ctl.crte,
17729 										 NULL, rack->r_ctl.pace_len_divisor);
17730 						rack_log_hdwr_pacing(rack,
17731 								     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
17732 								     err, 2);
17733 						rack->r_ctl.last_hw_bw_req = rate_wanted;
17734 					}
17735 				} else {
17736 					/* We just need to adjust the segment size */
17737 					rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
17738 					rack_log_hdwr_pacing(rack,
17739 							     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
17740 							     0, 4);
17741 					rack->r_ctl.last_hw_bw_req = rate_wanted;
17742 				}
17743 			}
17744 		}
17745 		if (minslot && (minslot > slot)) {
17746 			rack_log_pacing_delay_calc(rack, minslot, slot, rack->r_ctl.crte->rate, bw_est, lentim,
17747 						   98, __LINE__, NULL, 0);
17748 			slot = minslot;
17749 		}
17750 done_w_hdwr:
17751 		if (rack_limit_time_with_srtt &&
17752 		    (rack->use_fixed_rate == 0) &&
17753 		    (rack->rack_hdrw_pacing == 0)) {
17754 			/*
17755 			 * Sanity check, we do not allow the pacing delay
17756 			 * to be longer than the SRTT of the path. If it is
17757 			 * a slow path, then adding a packet should increase
17758 			 * the RTT and compensate for this i.e. the srtt will
17759 			 * be greater so the allowed pacing time will be greater.
17760 			 *
17761 			 * Note this restriction is not for where a peak rate
17762 			 * is set, we are doing fixed pacing or hardware pacing.
17763 			 */
17764 			if (rack->rc_tp->t_srtt)
17765 				srtt = rack->rc_tp->t_srtt;
17766 			else
17767 				srtt = RACK_INITIAL_RTO * HPTS_USEC_IN_MSEC;	/* its in ms convert */
17768 			if (srtt < (uint64_t)slot) {
17769 				rack_log_pacing_delay_calc(rack, srtt, slot, rate_wanted, bw_est, lentim, 99, __LINE__, NULL, 0);
17770 				slot = srtt;
17771 			}
17772 		}
17773 		/*******************************************************************/
17774 		/* RRS: We insert paced call to stats here for len and rate_wanted */
17775 		/*******************************************************************/
17776 		rack_log_pacing_delay_calc(rack, len, slot, rate_wanted, bw_est, lentim, 2, __LINE__, rsm, 0);
17777 	}
17778 	if (rack->r_ctl.crte && (rack->r_ctl.crte->rs_num_enobufs > 0)) {
17779 		/*
17780 		 * If this rate is seeing enobufs when it
17781 		 * goes to send then either the nic is out
17782 		 * of gas or we are mis-estimating the time
17783 		 * somehow and not letting the queue empty
17784 		 * completely. Lets add to the pacing time.
17785 		 */
17786 		int hw_boost_delay;
17787 
17788 		hw_boost_delay = rack->r_ctl.crte->time_between * rack_enobuf_hw_boost_mult;
17789 		if (hw_boost_delay > rack_enobuf_hw_max)
17790 			hw_boost_delay = rack_enobuf_hw_max;
17791 		else if (hw_boost_delay < rack_enobuf_hw_min)
17792 			hw_boost_delay = rack_enobuf_hw_min;
17793 		slot += hw_boost_delay;
17794 	}
17795 	return (slot);
17796 }
17797 
17798 static void
17799 rack_start_gp_measurement(struct tcpcb *tp, struct tcp_rack *rack,
17800     tcp_seq startseq, uint32_t sb_offset)
17801 {
17802 	struct rack_sendmap *my_rsm = NULL;
17803 
17804 	if (tp->t_state < TCPS_ESTABLISHED) {
17805 		/*
17806 		 * We don't start any measurements if we are
17807 		 * not at least established.
17808 		 */
17809 		return;
17810 	}
17811 	if (tp->t_state >= TCPS_FIN_WAIT_1) {
17812 		/*
17813 		 * We will get no more data into the SB
17814 		 * this means we need to have the data available
17815 		 * before we start a measurement.
17816 		 */
17817 
17818 		if (sbavail(&tptosocket(tp)->so_snd) <
17819 		    max(rc_init_window(rack),
17820 			(MIN_GP_WIN * ctf_fixed_maxseg(tp)))) {
17821 			/* Nope not enough data */
17822 			return;
17823 		}
17824 	}
17825 	tp->t_flags |= TF_GPUTINPROG;
17826 	rack->r_ctl.rc_gp_cumack_ts = 0;
17827 	rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
17828 	rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
17829 	tp->gput_seq = startseq;
17830 	rack->app_limited_needs_set = 0;
17831 	if (rack->in_probe_rtt)
17832 		rack->measure_saw_probe_rtt = 1;
17833 	else if ((rack->measure_saw_probe_rtt) &&
17834 		 (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
17835 		rack->measure_saw_probe_rtt = 0;
17836 	if (rack->rc_gp_filled)
17837 		tp->gput_ts = rack->r_ctl.last_cumack_advance;
17838 	else {
17839 		/* Special case initial measurement */
17840 		struct timeval tv;
17841 
17842 		tp->gput_ts = tcp_get_usecs(&tv);
17843 		rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
17844 	}
17845 	/*
17846 	 * We take a guess out into the future,
17847 	 * if we have no measurement and no
17848 	 * initial rate, we measure the first
17849 	 * initial-windows worth of data to
17850 	 * speed up getting some GP measurement and
17851 	 * thus start pacing.
17852 	 */
17853 	if ((rack->rc_gp_filled == 0) && (rack->r_ctl.init_rate == 0)) {
17854 		rack->app_limited_needs_set = 1;
17855 		tp->gput_ack = startseq + max(rc_init_window(rack),
17856 					      (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
17857 		rack_log_pacing_delay_calc(rack,
17858 					   tp->gput_seq,
17859 					   tp->gput_ack,
17860 					   0,
17861 					   tp->gput_ts,
17862 					   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) | (uint64_t)rack->r_ctl.rc_gp_output_ts),
17863 					   9,
17864 					   __LINE__, NULL, 0);
17865 		rack_tend_gp_marks(tp, rack);
17866 		rack_log_gpset(rack, tp->gput_ack, 0, 0, __LINE__, 1, NULL);
17867 		return;
17868 	}
17869 	if (sb_offset) {
17870 		/*
17871 		 * We are out somewhere in the sb
17872 		 * can we use the already outstanding data?
17873 		 */
17874 
17875 		if (rack->r_ctl.rc_app_limited_cnt == 0) {
17876 			/*
17877 			 * Yes first one is good and in this case
17878 			 * the tp->gput_ts is correctly set based on
17879 			 * the last ack that arrived (no need to
17880 			 * set things up when an ack comes in).
17881 			 */
17882 			my_rsm = tqhash_min(rack->r_ctl.tqh);
17883 			if ((my_rsm == NULL) ||
17884 			    (my_rsm->r_rtr_cnt != 1)) {
17885 				/* retransmission? */
17886 				goto use_latest;
17887 			}
17888 		} else {
17889 			if (rack->r_ctl.rc_first_appl == NULL) {
17890 				/*
17891 				 * If rc_first_appl is NULL
17892 				 * then the cnt should be 0.
17893 				 * This is probably an error, maybe
17894 				 * a KASSERT would be approprate.
17895 				 */
17896 				goto use_latest;
17897 			}
17898 			/*
17899 			 * If we have a marker pointer to the last one that is
17900 			 * app limited we can use that, but we need to set
17901 			 * things up so that when it gets ack'ed we record
17902 			 * the ack time (if its not already acked).
17903 			 */
17904 			rack->app_limited_needs_set = 1;
17905 			/*
17906 			 * We want to get to the rsm that is either
17907 			 * next with space i.e. over 1 MSS or the one
17908 			 * after that (after the app-limited).
17909 			 */
17910 			my_rsm = tqhash_next(rack->r_ctl.tqh, rack->r_ctl.rc_first_appl);
17911 			if (my_rsm) {
17912 				if ((my_rsm->r_end - my_rsm->r_start) <= ctf_fixed_maxseg(tp))
17913 					/* Have to use the next one */
17914 					my_rsm = tqhash_next(rack->r_ctl.tqh, my_rsm);
17915 				else {
17916 					/* Use after the first MSS of it is acked */
17917 					tp->gput_seq = my_rsm->r_start + ctf_fixed_maxseg(tp);
17918 					goto start_set;
17919 				}
17920 			}
17921 			if ((my_rsm == NULL) ||
17922 			    (my_rsm->r_rtr_cnt != 1)) {
17923 				/*
17924 				 * Either its a retransmit or
17925 				 * the last is the app-limited one.
17926 				 */
17927 				goto use_latest;
17928 			}
17929 		}
17930 		tp->gput_seq = my_rsm->r_start;
17931 start_set:
17932 		if (my_rsm->r_flags & RACK_ACKED) {
17933 			/*
17934 			 * This one has been acked use the arrival ack time
17935 			 */
17936 			struct rack_sendmap *nrsm;
17937 
17938 			tp->gput_ts = (uint32_t)my_rsm->r_ack_arrival;
17939 			rack->app_limited_needs_set = 0;
17940 			/*
17941 			 * Ok in this path we need to use the r_end now
17942 			 * since this guy is the starting ack.
17943 			 */
17944 			tp->gput_seq = my_rsm->r_end;
17945 			/*
17946 			 * We also need to adjust up the sendtime
17947 			 * to the send of the next data after my_rsm.
17948 			 */
17949 			nrsm = tqhash_next(rack->r_ctl.tqh, my_rsm);
17950 			if (nrsm != NULL)
17951 				my_rsm = nrsm;
17952 			else {
17953 				/*
17954 				 * The next as not been sent, thats the
17955 				 * case for using the latest.
17956 				 */
17957 				goto use_latest;
17958 			}
17959 		}
17960 		rack->r_ctl.rc_gp_output_ts = my_rsm->r_tim_lastsent[0];
17961 		tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
17962 		rack->r_ctl.rc_gp_cumack_ts = 0;
17963 		rack_log_pacing_delay_calc(rack,
17964 					   tp->gput_seq,
17965 					   tp->gput_ack,
17966 					   (uint64_t)my_rsm,
17967 					   tp->gput_ts,
17968 					   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) | (uint64_t)rack->r_ctl.rc_gp_output_ts),
17969 					   9,
17970 					   __LINE__, my_rsm, 0);
17971 		/* Now lets make sure all are marked as they should be */
17972 		rack_tend_gp_marks(tp, rack);
17973 		rack_log_gpset(rack, tp->gput_ack, 0, 0, __LINE__, 1, NULL);
17974 		return;
17975 	}
17976 
17977 use_latest:
17978 	/*
17979 	 * We don't know how long we may have been
17980 	 * idle or if this is the first-send. Lets
17981 	 * setup the flag so we will trim off
17982 	 * the first ack'd data so we get a true
17983 	 * measurement.
17984 	 */
17985 	rack->app_limited_needs_set = 1;
17986 	tp->gput_ack = startseq + rack_get_measure_window(tp, rack);
17987 	rack->r_ctl.rc_gp_cumack_ts = 0;
17988 	/* Find this guy so we can pull the send time */
17989 	my_rsm = tqhash_find(rack->r_ctl.tqh, startseq);
17990 	if (my_rsm) {
17991 		rack->r_ctl.rc_gp_output_ts = my_rsm->r_tim_lastsent[0];
17992 		if (my_rsm->r_flags & RACK_ACKED) {
17993 			/*
17994 			 * Unlikely since its probably what was
17995 			 * just transmitted (but I am paranoid).
17996 			 */
17997 			tp->gput_ts = (uint32_t)my_rsm->r_ack_arrival;
17998 			rack->app_limited_needs_set = 0;
17999 		}
18000 		if (SEQ_LT(my_rsm->r_start, tp->gput_seq)) {
18001 			/* This also is unlikely */
18002 			tp->gput_seq = my_rsm->r_start;
18003 		}
18004 	} else {
18005 		/*
18006 		 * TSNH unless we have some send-map limit,
18007 		 * and even at that it should not be hitting
18008 		 * that limit (we should have stopped sending).
18009 		 */
18010 		struct timeval tv;
18011 
18012 		microuptime(&tv);
18013 		rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
18014 	}
18015 	rack_tend_gp_marks(tp, rack);
18016 	rack_log_pacing_delay_calc(rack,
18017 				   tp->gput_seq,
18018 				   tp->gput_ack,
18019 				   (uint64_t)my_rsm,
18020 				   tp->gput_ts,
18021 				   (((uint64_t)rack->r_ctl.rc_app_limited_cnt << 32) | (uint64_t)rack->r_ctl.rc_gp_output_ts),
18022 				   9, __LINE__, NULL, 0);
18023 	rack_log_gpset(rack, tp->gput_ack, 0, 0, __LINE__, 1, NULL);
18024 }
18025 
18026 static inline uint32_t
18027 rack_what_can_we_send(struct tcpcb *tp, struct tcp_rack *rack,  uint32_t cwnd_to_use,
18028     uint32_t avail, int32_t sb_offset)
18029 {
18030 	uint32_t len;
18031 	uint32_t sendwin;
18032 
18033 	if (tp->snd_wnd > cwnd_to_use)
18034 		sendwin = cwnd_to_use;
18035 	else
18036 		sendwin = tp->snd_wnd;
18037 	if (ctf_outstanding(tp) >= tp->snd_wnd) {
18038 		/* We never want to go over our peers rcv-window */
18039 		len = 0;
18040 	} else {
18041 		uint32_t flight;
18042 
18043 		flight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
18044 		if (flight >= sendwin) {
18045 			/*
18046 			 * We have in flight what we are allowed by cwnd (if
18047 			 * it was rwnd blocking it would have hit above out
18048 			 * >= tp->snd_wnd).
18049 			 */
18050 			return (0);
18051 		}
18052 		len = sendwin - flight;
18053 		if ((len + ctf_outstanding(tp)) > tp->snd_wnd) {
18054 			/* We would send too much (beyond the rwnd) */
18055 			len = tp->snd_wnd - ctf_outstanding(tp);
18056 		}
18057 		if ((len + sb_offset) > avail) {
18058 			/*
18059 			 * We don't have that much in the SB, how much is
18060 			 * there?
18061 			 */
18062 			len = avail - sb_offset;
18063 		}
18064 	}
18065 	return (len);
18066 }
18067 
18068 static void
18069 rack_log_fsb(struct tcp_rack *rack, struct tcpcb *tp, struct socket *so, uint32_t flags,
18070 	     unsigned ipoptlen, int32_t orig_len, int32_t len, int error,
18071 	     int rsm_is_null, int optlen, int line, uint16_t mode)
18072 {
18073 	if (tcp_bblogging_on(rack->rc_tp)) {
18074 		union tcp_log_stackspecific log;
18075 		struct timeval tv;
18076 
18077 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
18078 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
18079 		log.u_bbr.flex1 = error;
18080 		log.u_bbr.flex2 = flags;
18081 		log.u_bbr.flex3 = rsm_is_null;
18082 		log.u_bbr.flex4 = ipoptlen;
18083 		log.u_bbr.flex5 = tp->rcv_numsacks;
18084 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
18085 		log.u_bbr.flex7 = optlen;
18086 		log.u_bbr.flex8 = rack->r_fsb_inited;
18087 		log.u_bbr.applimited = rack->r_fast_output;
18088 		log.u_bbr.bw_inuse = rack_get_bw(rack);
18089 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
18090 		log.u_bbr.cwnd_gain = mode;
18091 		log.u_bbr.pkts_out = orig_len;
18092 		log.u_bbr.lt_epoch = len;
18093 		log.u_bbr.delivered = line;
18094 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
18095 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
18096 		tcp_log_event(tp, NULL, &so->so_rcv, &so->so_snd, TCP_LOG_FSB, 0,
18097 			       len, &log, false, NULL, __func__, __LINE__, &tv);
18098 	}
18099 }
18100 
18101 
18102 static struct mbuf *
18103 rack_fo_base_copym(struct mbuf *the_m, uint32_t the_off, int32_t *plen,
18104 		   struct rack_fast_send_blk *fsb,
18105 		   int32_t seglimit, int32_t segsize, int hw_tls)
18106 {
18107 #ifdef KERN_TLS
18108 	struct ktls_session *tls, *ntls;
18109 #ifdef INVARIANTS
18110 	struct mbuf *start;
18111 #endif
18112 #endif
18113 	struct mbuf *m, *n, **np, *smb;
18114 	struct mbuf *top;
18115 	int32_t off, soff;
18116 	int32_t len = *plen;
18117 	int32_t fragsize;
18118 	int32_t len_cp = 0;
18119 	uint32_t mlen, frags;
18120 
18121 	soff = off = the_off;
18122 	smb = m = the_m;
18123 	np = &top;
18124 	top = NULL;
18125 #ifdef KERN_TLS
18126 	if (hw_tls && (m->m_flags & M_EXTPG))
18127 		tls = m->m_epg_tls;
18128 	else
18129 		tls = NULL;
18130 #ifdef INVARIANTS
18131 	start = m;
18132 #endif
18133 #endif
18134 	while (len > 0) {
18135 		if (m == NULL) {
18136 			*plen = len_cp;
18137 			break;
18138 		}
18139 #ifdef KERN_TLS
18140 		if (hw_tls) {
18141 			if (m->m_flags & M_EXTPG)
18142 				ntls = m->m_epg_tls;
18143 			else
18144 				ntls = NULL;
18145 
18146 			/*
18147 			 * Avoid mixing TLS records with handshake
18148 			 * data or TLS records from different
18149 			 * sessions.
18150 			 */
18151 			if (tls != ntls) {
18152 				MPASS(m != start);
18153 				*plen = len_cp;
18154 				break;
18155 			}
18156 		}
18157 #endif
18158 		mlen = min(len, m->m_len - off);
18159 		if (seglimit) {
18160 			/*
18161 			 * For M_EXTPG mbufs, add 3 segments
18162 			 * + 1 in case we are crossing page boundaries
18163 			 * + 2 in case the TLS hdr/trailer are used
18164 			 * It is cheaper to just add the segments
18165 			 * than it is to take the cache miss to look
18166 			 * at the mbuf ext_pgs state in detail.
18167 			 */
18168 			if (m->m_flags & M_EXTPG) {
18169 				fragsize = min(segsize, PAGE_SIZE);
18170 				frags = 3;
18171 			} else {
18172 				fragsize = segsize;
18173 				frags = 0;
18174 			}
18175 
18176 			/* Break if we really can't fit anymore. */
18177 			if ((frags + 1) >= seglimit) {
18178 				*plen =	len_cp;
18179 				break;
18180 			}
18181 
18182 			/*
18183 			 * Reduce size if you can't copy the whole
18184 			 * mbuf. If we can't copy the whole mbuf, also
18185 			 * adjust len so the loop will end after this
18186 			 * mbuf.
18187 			 */
18188 			if ((frags + howmany(mlen, fragsize)) >= seglimit) {
18189 				mlen = (seglimit - frags - 1) * fragsize;
18190 				len = mlen;
18191 				*plen = len_cp + len;
18192 			}
18193 			frags += howmany(mlen, fragsize);
18194 			if (frags == 0)
18195 				frags++;
18196 			seglimit -= frags;
18197 			KASSERT(seglimit > 0,
18198 			    ("%s: seglimit went too low", __func__));
18199 		}
18200 		n = m_get(M_NOWAIT, m->m_type);
18201 		*np = n;
18202 		if (n == NULL)
18203 			goto nospace;
18204 		n->m_len = mlen;
18205 		soff += mlen;
18206 		len_cp += n->m_len;
18207 		if (m->m_flags & (M_EXT|M_EXTPG)) {
18208 			n->m_data = m->m_data + off;
18209 			mb_dupcl(n, m);
18210 		} else {
18211 			bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t),
18212 			    (u_int)n->m_len);
18213 		}
18214 		len -= n->m_len;
18215 		off = 0;
18216 		m = m->m_next;
18217 		np = &n->m_next;
18218 		if (len || (soff == smb->m_len)) {
18219 			/*
18220 			 * We have more so we move forward  or
18221 			 * we have consumed the entire mbuf and
18222 			 * len has fell to 0.
18223 			 */
18224 			soff = 0;
18225 			smb = m;
18226 		}
18227 
18228 	}
18229 	if (fsb != NULL) {
18230 		fsb->m = smb;
18231 		fsb->off = soff;
18232 		if (smb) {
18233 			/*
18234 			 * Save off the size of the mbuf. We do
18235 			 * this so that we can recognize when it
18236 			 * has been trimmed by sbcut() as acks
18237 			 * come in.
18238 			 */
18239 			fsb->o_m_len = smb->m_len;
18240 			fsb->o_t_len = M_TRAILINGROOM(smb);
18241 		} else {
18242 			/*
18243 			 * This is the case where the next mbuf went to NULL. This
18244 			 * means with this copy we have sent everything in the sb.
18245 			 * In theory we could clear the fast_output flag, but lets
18246 			 * not since its possible that we could get more added
18247 			 * and acks that call the extend function which would let
18248 			 * us send more.
18249 			 */
18250 			fsb->o_m_len = 0;
18251 			fsb->o_t_len = 0;
18252 		}
18253 	}
18254 	return (top);
18255 nospace:
18256 	if (top)
18257 		m_freem(top);
18258 	return (NULL);
18259 
18260 }
18261 
18262 /*
18263  * This is a copy of m_copym(), taking the TSO segment size/limit
18264  * constraints into account, and advancing the sndptr as it goes.
18265  */
18266 static struct mbuf *
18267 rack_fo_m_copym(struct tcp_rack *rack, int32_t *plen,
18268 		int32_t seglimit, int32_t segsize, struct mbuf **s_mb, int *s_soff)
18269 {
18270 	struct mbuf *m, *n;
18271 	int32_t soff;
18272 
18273 	m = rack->r_ctl.fsb.m;
18274 	if (M_TRAILINGROOM(m) != rack->r_ctl.fsb.o_t_len) {
18275 		/*
18276 		 * The trailing space changed, mbufs can grow
18277 		 * at the tail but they can't shrink from
18278 		 * it, KASSERT that. Adjust the orig_m_len to
18279 		 * compensate for this change.
18280 		 */
18281 		KASSERT((rack->r_ctl.fsb.o_t_len > M_TRAILINGROOM(m)),
18282 			("mbuf:%p rack:%p trailing_space:%jd ots:%u oml:%u mlen:%u\n",
18283 			 m,
18284 			 rack,
18285 			 (intmax_t)M_TRAILINGROOM(m),
18286 			 rack->r_ctl.fsb.o_t_len,
18287 			 rack->r_ctl.fsb.o_m_len,
18288 			 m->m_len));
18289 		rack->r_ctl.fsb.o_m_len += (rack->r_ctl.fsb.o_t_len - M_TRAILINGROOM(m));
18290 		rack->r_ctl.fsb.o_t_len = M_TRAILINGROOM(m);
18291 	}
18292 	if (m->m_len < rack->r_ctl.fsb.o_m_len) {
18293 		/*
18294 		 * Mbuf shrank, trimmed off the top by an ack, our
18295 		 * offset changes.
18296 		 */
18297 		KASSERT((rack->r_ctl.fsb.off >= (rack->r_ctl.fsb.o_m_len - m->m_len)),
18298 			("mbuf:%p len:%u rack:%p oml:%u soff:%u\n",
18299 			 m, m->m_len,
18300 			 rack, rack->r_ctl.fsb.o_m_len,
18301 			 rack->r_ctl.fsb.off));
18302 
18303 		if (rack->r_ctl.fsb.off >= (rack->r_ctl.fsb.o_m_len- m->m_len))
18304 			rack->r_ctl.fsb.off -= (rack->r_ctl.fsb.o_m_len - m->m_len);
18305 		else
18306 			rack->r_ctl.fsb.off = 0;
18307 		rack->r_ctl.fsb.o_m_len = m->m_len;
18308 #ifdef INVARIANTS
18309 	} else if (m->m_len > rack->r_ctl.fsb.o_m_len) {
18310 		panic("rack:%p m:%p m_len grew outside of t_space compensation",
18311 		      rack, m);
18312 #endif
18313 	}
18314 	soff = rack->r_ctl.fsb.off;
18315 	KASSERT(soff >= 0, ("%s, negative off %d", __FUNCTION__, soff));
18316 	KASSERT(*plen >= 0, ("%s, negative len %d", __FUNCTION__, *plen));
18317 	KASSERT(soff < m->m_len, ("%s rack:%p len:%u m:%p m->m_len:%u < off?",
18318 				 __FUNCTION__,
18319 				 rack, *plen, m, m->m_len));
18320 	/* Save off the right location before we copy and advance */
18321 	*s_soff = soff;
18322 	*s_mb = rack->r_ctl.fsb.m;
18323 	n = rack_fo_base_copym(m, soff, plen,
18324 			       &rack->r_ctl.fsb,
18325 			       seglimit, segsize, rack->r_ctl.fsb.hw_tls);
18326 	return (n);
18327 }
18328 
18329 /* Log the buffer level */
18330 static void
18331 rack_log_queue_level(struct tcpcb *tp, struct tcp_rack *rack,
18332 		     int len, struct timeval *tv,
18333 		     uint32_t cts)
18334 {
18335 	uint32_t p_rate = 0, p_queue = 0, err = 0;
18336 	union tcp_log_stackspecific log;
18337 
18338 #ifdef RATELIMIT
18339 	err = in_pcbquery_txrlevel(rack->rc_inp, &p_queue);
18340 	err = in_pcbquery_txrtlmt(rack->rc_inp,	&p_rate);
18341 #endif
18342 	memset(&log.u_bbr, 0, sizeof(log.u_bbr));
18343 	log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
18344 	log.u_bbr.flex1 = p_rate;
18345 	log.u_bbr.flex2 = p_queue;
18346 	log.u_bbr.flex4 = (uint32_t)rack->r_ctl.crte->using;
18347 	log.u_bbr.flex5 = (uint32_t)rack->r_ctl.crte->rs_num_enobufs;
18348 	log.u_bbr.flex6 = rack->r_ctl.crte->time_between;
18349 	log.u_bbr.flex7 = 99;
18350 	log.u_bbr.flex8 = 0;
18351 	log.u_bbr.pkts_out = err;
18352 	log.u_bbr.delRate = rack->r_ctl.crte->rate;
18353 	log.u_bbr.timeStamp = cts;
18354 	log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
18355 	tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_HDWR_PACE, 0,
18356 		       len, &log, false, NULL, __func__, __LINE__, tv);
18357 
18358 }
18359 
18360 static uint32_t
18361 rack_check_queue_level(struct tcp_rack *rack, struct tcpcb *tp,
18362 		       struct timeval *tv, uint32_t cts, int len, uint32_t segsiz)
18363 {
18364 	uint64_t lentime = 0;
18365 #ifdef RATELIMIT
18366 	uint32_t p_rate = 0, p_queue = 0, err;
18367 	union tcp_log_stackspecific log;
18368 	uint64_t bw;
18369 
18370 	err = in_pcbquery_txrlevel(rack->rc_inp, &p_queue);
18371 	/* Failed or queue is zero */
18372 	if (err || (p_queue == 0)) {
18373 		lentime = 0;
18374 		goto out;
18375 	}
18376 	err = in_pcbquery_txrtlmt(rack->rc_inp, &p_rate);
18377 	if (err) {
18378 		lentime = 0;
18379 		goto out;
18380 	}
18381 	/*
18382 	 * If we reach here we have some bytes in
18383 	 * the queue. The number returned is a value
18384 	 * between 0 and 0xffff where ffff is full
18385 	 * and 0 is empty. So how best to make this into
18386 	 * something usable?
18387 	 *
18388 	 * The "safer" way is lets take the b/w gotten
18389 	 * from the query (which should be our b/w rate)
18390 	 * and pretend that a full send (our rc_pace_max_segs)
18391 	 * is outstanding. We factor it so its as if a full
18392 	 * number of our MSS segment is terms of full
18393 	 * ethernet segments are outstanding.
18394 	 */
18395 	bw = p_rate / 8;
18396 	if (bw) {
18397 		lentime = (rack->r_ctl.rc_pace_max_segs / segsiz);
18398 		lentime *= ETHERNET_SEGMENT_SIZE;
18399 		lentime *= (uint64_t)HPTS_USEC_IN_SEC;
18400 		lentime /= bw;
18401 	} else {
18402 		/* TSNH -- KASSERT? */
18403 		lentime = 0;
18404 	}
18405 out:
18406 	if (tcp_bblogging_on(tp)) {
18407 		memset(&log, 0, sizeof(log));
18408 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
18409 		log.u_bbr.flex1 = p_rate;
18410 		log.u_bbr.flex2 = p_queue;
18411 		log.u_bbr.flex4 = (uint32_t)rack->r_ctl.crte->using;
18412 		log.u_bbr.flex5 = (uint32_t)rack->r_ctl.crte->rs_num_enobufs;
18413 		log.u_bbr.flex6 = rack->r_ctl.crte->time_between;
18414 		log.u_bbr.flex7 = 99;
18415 		log.u_bbr.flex8 = 0;
18416 		log.u_bbr.pkts_out = err;
18417 		log.u_bbr.delRate = rack->r_ctl.crte->rate;
18418 		log.u_bbr.cur_del_rate = lentime;
18419 		log.u_bbr.timeStamp = cts;
18420 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
18421 		tcp_log_event(tp, NULL, NULL, NULL, BBR_LOG_HDWR_PACE, 0,
18422 			       len, &log, false, NULL, __func__, __LINE__,tv);
18423 	}
18424 #endif
18425 	return ((uint32_t)lentime);
18426 }
18427 
18428 static int
18429 rack_fast_rsm_output(struct tcpcb *tp, struct tcp_rack *rack, struct rack_sendmap *rsm,
18430 		     uint64_t ts_val, uint32_t cts, uint32_t ms_cts, struct timeval *tv, int len, uint8_t doing_tlp)
18431 {
18432 	/*
18433 	 * Enter the fast retransmit path. We are given that a sched_pin is
18434 	 * in place (if accounting is compliled in) and the cycle count taken
18435 	 * at the entry is in the ts_val. The concept her is that the rsm
18436 	 * now holds the mbuf offsets and such so we can directly transmit
18437 	 * without a lot of overhead, the len field is already set for
18438 	 * us to prohibit us from sending too much (usually its 1MSS).
18439 	 */
18440 	struct ip *ip = NULL;
18441 	struct udphdr *udp = NULL;
18442 	struct tcphdr *th = NULL;
18443 	struct mbuf *m = NULL;
18444 	struct inpcb *inp;
18445 	uint8_t *cpto;
18446 	struct tcp_log_buffer *lgb;
18447 #ifdef TCP_ACCOUNTING
18448 	uint64_t crtsc;
18449 	int cnt_thru = 1;
18450 #endif
18451 	struct tcpopt to;
18452 	u_char opt[TCP_MAXOLEN];
18453 	uint32_t hdrlen, optlen;
18454 	int32_t slot, segsiz, max_val, tso = 0, error = 0, ulen = 0;
18455 	uint16_t flags;
18456 	uint32_t if_hw_tsomaxsegcount = 0, startseq;
18457 	uint32_t if_hw_tsomaxsegsize;
18458 	int32_t ip_sendflag = IP_NO_SND_TAG_RL;
18459 
18460 #ifdef INET6
18461 	struct ip6_hdr *ip6 = NULL;
18462 
18463 	if (rack->r_is_v6) {
18464 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
18465 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
18466 	} else
18467 #endif				/* INET6 */
18468 	{
18469 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
18470 		hdrlen = sizeof(struct tcpiphdr);
18471 	}
18472 	if (tp->t_port && (V_tcp_udp_tunneling_port == 0)) {
18473 		goto failed;
18474 	}
18475 	if (doing_tlp) {
18476 		/* Its a TLP add the flag, it may already be there but be sure */
18477 		rsm->r_flags |= RACK_TLP;
18478 	} else {
18479 		/* If it was a TLP it is not not on this retransmit */
18480 		rsm->r_flags &= ~RACK_TLP;
18481 	}
18482 	startseq = rsm->r_start;
18483 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
18484 	inp = rack->rc_inp;
18485 	to.to_flags = 0;
18486 	flags = tcp_outflags[tp->t_state];
18487 	if (flags & (TH_SYN|TH_RST)) {
18488 		goto failed;
18489 	}
18490 	if (rsm->r_flags & RACK_HAS_FIN) {
18491 		/* We can't send a FIN here */
18492 		goto failed;
18493 	}
18494 	if (flags & TH_FIN) {
18495 		/* We never send a FIN */
18496 		flags &= ~TH_FIN;
18497 	}
18498 	if (tp->t_flags & TF_RCVD_TSTMP) {
18499 		to.to_tsval = ms_cts + tp->ts_offset;
18500 		to.to_tsecr = tp->ts_recent;
18501 		to.to_flags = TOF_TS;
18502 	}
18503 	optlen = tcp_addoptions(&to, opt);
18504 	hdrlen += optlen;
18505 	udp = rack->r_ctl.fsb.udp;
18506 	if (udp)
18507 		hdrlen += sizeof(struct udphdr);
18508 	if (rack->r_ctl.rc_pace_max_segs)
18509 		max_val = rack->r_ctl.rc_pace_max_segs;
18510 	else if (rack->rc_user_set_max_segs)
18511 		max_val = rack->rc_user_set_max_segs * segsiz;
18512 	else
18513 		max_val = len;
18514 	if ((tp->t_flags & TF_TSO) &&
18515 	    V_tcp_do_tso &&
18516 	    (len > segsiz) &&
18517 	    (tp->t_port == 0))
18518 		tso = 1;
18519 #ifdef INET6
18520 	if (MHLEN < hdrlen + max_linkhdr)
18521 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
18522 	else
18523 #endif
18524 		m = m_gethdr(M_NOWAIT, MT_DATA);
18525 	if (m == NULL)
18526 		goto failed;
18527 	m->m_data += max_linkhdr;
18528 	m->m_len = hdrlen;
18529 	th = rack->r_ctl.fsb.th;
18530 	/* Establish the len to send */
18531 	if (len > max_val)
18532 		len = max_val;
18533 	if ((tso) && (len + optlen > segsiz)) {
18534 		uint32_t if_hw_tsomax;
18535 		int32_t max_len;
18536 
18537 		/* extract TSO information */
18538 		if_hw_tsomax = tp->t_tsomax;
18539 		if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
18540 		if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
18541 		/*
18542 		 * Check if we should limit by maximum payload
18543 		 * length:
18544 		 */
18545 		if (if_hw_tsomax != 0) {
18546 			/* compute maximum TSO length */
18547 			max_len = (if_hw_tsomax - hdrlen -
18548 				   max_linkhdr);
18549 			if (max_len <= 0) {
18550 				goto failed;
18551 			} else if (len > max_len) {
18552 				len = max_len;
18553 			}
18554 		}
18555 		if (len <= segsiz) {
18556 			/*
18557 			 * In case there are too many small fragments don't
18558 			 * use TSO:
18559 			 */
18560 			tso = 0;
18561 		}
18562 	} else {
18563 		tso = 0;
18564 	}
18565 	if ((tso == 0) && (len > segsiz))
18566 		len = segsiz;
18567 	(void)tcp_get_usecs(tv);
18568 	if ((len == 0) ||
18569 	    (len <= MHLEN - hdrlen - max_linkhdr)) {
18570 		goto failed;
18571 	}
18572 	th->th_seq = htonl(rsm->r_start);
18573 	th->th_ack = htonl(tp->rcv_nxt);
18574 	/*
18575 	 * The PUSH bit should only be applied
18576 	 * if the full retransmission is made. If
18577 	 * we are sending less than this is the
18578 	 * left hand edge and should not have
18579 	 * the PUSH bit.
18580 	 */
18581 	if ((rsm->r_flags & RACK_HAD_PUSH) &&
18582 	    (len == (rsm->r_end - rsm->r_start)))
18583 		flags |= TH_PUSH;
18584 	th->th_win = htons((u_short)(rack->r_ctl.fsb.recwin >> tp->rcv_scale));
18585 	if (th->th_win == 0) {
18586 		tp->t_sndzerowin++;
18587 		tp->t_flags |= TF_RXWIN0SENT;
18588 	} else
18589 		tp->t_flags &= ~TF_RXWIN0SENT;
18590 	if (rsm->r_flags & RACK_TLP) {
18591 		/*
18592 		 * TLP should not count in retran count, but
18593 		 * in its own bin
18594 		 */
18595 		counter_u64_add(rack_tlp_retran, 1);
18596 		counter_u64_add(rack_tlp_retran_bytes, len);
18597 	} else {
18598 		tp->t_sndrexmitpack++;
18599 		KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
18600 		KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
18601 	}
18602 #ifdef STATS
18603 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
18604 				 len);
18605 #endif
18606 	if (rsm->m == NULL)
18607 		goto failed;
18608 	if (rsm->m &&
18609 	    ((rsm->orig_m_len != rsm->m->m_len) ||
18610 	     (M_TRAILINGROOM(rsm->m) != rsm->orig_t_space))) {
18611 		/* Fix up the orig_m_len and possibly the mbuf offset */
18612 		rack_adjust_orig_mlen(rsm);
18613 	}
18614 	m->m_next = rack_fo_base_copym(rsm->m, rsm->soff, &len, NULL, if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, rsm->r_hw_tls);
18615 	if (len <= segsiz) {
18616 		/*
18617 		 * Must have ran out of mbufs for the copy
18618 		 * shorten it to no longer need tso. Lets
18619 		 * not put on sendalot since we are low on
18620 		 * mbufs.
18621 		 */
18622 		tso = 0;
18623 	}
18624 	if ((m->m_next == NULL) || (len <= 0)){
18625 		goto failed;
18626 	}
18627 	if (udp) {
18628 		if (rack->r_is_v6)
18629 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
18630 		else
18631 			ulen = hdrlen + len - sizeof(struct ip);
18632 		udp->uh_ulen = htons(ulen);
18633 	}
18634 	m->m_pkthdr.rcvif = (struct ifnet *)0;
18635 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
18636 	    (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))) {
18637 		int ect = tcp_ecn_output_established(tp, &flags, len, true);
18638 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
18639 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
18640 		    tp->t_flags2 &= ~TF2_ECN_SND_ECE;
18641 #ifdef INET6
18642 		if (rack->r_is_v6) {
18643 		    ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
18644 		    ip6->ip6_flow |= htonl(ect << 20);
18645 		}
18646 		else
18647 #endif
18648 		{
18649 		    ip->ip_tos &= ~IPTOS_ECN_MASK;
18650 		    ip->ip_tos |= ect;
18651 		}
18652 	}
18653 	if (rack->r_ctl.crte != NULL) {
18654 		/* See if we can send via the hw queue */
18655 		slot = rack_check_queue_level(rack, tp, tv, cts, len, segsiz);
18656 		/* If there is nothing in queue (no pacing time) we can send via the hw queue */
18657 		if (slot == 0)
18658 			ip_sendflag = 0;
18659 	}
18660 	tcp_set_flags(th, flags);
18661 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
18662 #ifdef INET6
18663 	if (rack->r_is_v6) {
18664 		if (tp->t_port) {
18665 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
18666 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
18667 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
18668 			th->th_sum = htons(0);
18669 			UDPSTAT_INC(udps_opackets);
18670 		} else {
18671 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
18672 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
18673 			th->th_sum = in6_cksum_pseudo(ip6,
18674 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
18675 						      0);
18676 		}
18677 	}
18678 #endif
18679 #if defined(INET6) && defined(INET)
18680 	else
18681 #endif
18682 #ifdef INET
18683 	{
18684 		if (tp->t_port) {
18685 			m->m_pkthdr.csum_flags = CSUM_UDP;
18686 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
18687 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
18688 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
18689 			th->th_sum = htons(0);
18690 			UDPSTAT_INC(udps_opackets);
18691 		} else {
18692 			m->m_pkthdr.csum_flags = CSUM_TCP;
18693 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
18694 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
18695 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
18696 									IPPROTO_TCP + len + optlen));
18697 		}
18698 		/* IP version must be set here for ipv4/ipv6 checking later */
18699 		KASSERT(ip->ip_v == IPVERSION,
18700 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
18701 	}
18702 #endif
18703 	if (tso) {
18704 		/*
18705 		 * Here we use segsiz since we have no added options besides
18706 		 * any standard timestamp options (no DSACKs or SACKS are sent
18707 		 * via either fast-path).
18708 		 */
18709 		KASSERT(len > segsiz,
18710 			("%s: len <= tso_segsz tp:%p", __func__, tp));
18711 		m->m_pkthdr.csum_flags |= CSUM_TSO;
18712 		m->m_pkthdr.tso_segsz = segsiz;
18713 	}
18714 #ifdef INET6
18715 	if (rack->r_is_v6) {
18716 		ip6->ip6_hlim = rack->r_ctl.fsb.hoplimit;
18717 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
18718 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
18719 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
18720 		else
18721 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
18722 	}
18723 #endif
18724 #if defined(INET) && defined(INET6)
18725 	else
18726 #endif
18727 #ifdef INET
18728 	{
18729 		ip->ip_len = htons(m->m_pkthdr.len);
18730 		ip->ip_ttl = rack->r_ctl.fsb.hoplimit;
18731 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
18732 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
18733 			if (tp->t_port == 0 || len < V_tcp_minmss) {
18734 				ip->ip_off |= htons(IP_DF);
18735 			}
18736 		} else {
18737 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
18738 		}
18739 	}
18740 #endif
18741 	if (doing_tlp == 0) {
18742 		/* Set we retransmitted */
18743 		rack->rc_gp_saw_rec = 1;
18744 	} else {
18745 		/* Its a TLP set ca or ss */
18746 		if (tp->snd_cwnd > tp->snd_ssthresh) {
18747 			/* Set we sent in CA */
18748 			rack->rc_gp_saw_ca = 1;
18749 		} else {
18750 			/* Set we sent in SS */
18751 			rack->rc_gp_saw_ss = 1;
18752 		}
18753 	}
18754 	/* Time to copy in our header */
18755 	cpto = mtod(m, uint8_t *);
18756 	memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
18757 	th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
18758 	if (optlen) {
18759 		bcopy(opt, th + 1, optlen);
18760 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
18761 	} else {
18762 		th->th_off = sizeof(struct tcphdr) >> 2;
18763 	}
18764 	if (tcp_bblogging_on(rack->rc_tp)) {
18765 		union tcp_log_stackspecific log;
18766 
18767 		if (rsm->r_flags & RACK_RWND_COLLAPSED) {
18768 			rack_log_collapse(rack, rsm->r_start, rsm->r_end, 0, __LINE__, 5, rsm->r_flags, rsm);
18769 			counter_u64_add(rack_collapsed_win_rxt, 1);
18770 			counter_u64_add(rack_collapsed_win_rxt_bytes, (rsm->r_end - rsm->r_start));
18771 		}
18772 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
18773 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
18774 		if (rack->rack_no_prr)
18775 			log.u_bbr.flex1 = 0;
18776 		else
18777 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
18778 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
18779 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
18780 		log.u_bbr.flex4 = max_val;
18781 		/* Save off the early/late values */
18782 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
18783 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
18784 		log.u_bbr.bw_inuse = rack_get_bw(rack);
18785 		log.u_bbr.cur_del_rate = rack->r_ctl.gp_bw;
18786 		if (doing_tlp == 0)
18787 			log.u_bbr.flex8 = 1;
18788 		else
18789 			log.u_bbr.flex8 = 2;
18790 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
18791 		log.u_bbr.flex7 = 55;
18792 		log.u_bbr.pkts_out = tp->t_maxseg;
18793 		log.u_bbr.timeStamp = cts;
18794 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
18795 		if (rsm && (rsm->r_rtr_cnt > 0)) {
18796 			/*
18797 			 * When we have a retransmit we want to log the
18798 			 * burst at send and flight at send from before.
18799 			 */
18800 			log.u_bbr.flex5 = rsm->r_fas;
18801 			log.u_bbr.bbr_substate = rsm->r_bas;
18802 		} else {
18803 			/*
18804 			 * This is currently unlikely until we do the
18805 			 * packet pair probes but I will add it for completeness.
18806 			 */
18807 			log.u_bbr.flex5 = log.u_bbr.inflight;
18808 			log.u_bbr.bbr_substate = (uint8_t)((len + segsiz - 1)/segsiz);
18809 		}
18810 		log.u_bbr.lt_epoch = rack->r_ctl.cwnd_to_use;
18811 		log.u_bbr.delivered = 0;
18812 		log.u_bbr.rttProp = (uint64_t)rsm;
18813 		log.u_bbr.delRate = rsm->r_flags;
18814 		log.u_bbr.delRate <<= 31;
18815 		log.u_bbr.delRate |= rack->r_must_retran;
18816 		log.u_bbr.delRate <<= 1;
18817 		log.u_bbr.delRate |= 1;
18818 		log.u_bbr.pkt_epoch = __LINE__;
18819 		lgb = tcp_log_event(tp, th, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
18820 				     len, &log, false, NULL, __func__, __LINE__, tv);
18821 	} else
18822 		lgb = NULL;
18823 	if ((rack->r_ctl.crte != NULL) &&
18824 	    tcp_bblogging_on(tp)) {
18825 		rack_log_queue_level(tp, rack, len, tv, cts);
18826 	}
18827 #ifdef INET6
18828 	if (rack->r_is_v6) {
18829 		error = ip6_output(m, NULL,
18830 				   &inp->inp_route6,
18831 				   ip_sendflag, NULL, NULL, inp);
18832 	}
18833 	else
18834 #endif
18835 #ifdef INET
18836 	{
18837 		error = ip_output(m, NULL,
18838 				  &inp->inp_route,
18839 				  ip_sendflag, 0, inp);
18840 	}
18841 #endif
18842 	m = NULL;
18843 	if (lgb) {
18844 		lgb->tlb_errno = error;
18845 		lgb = NULL;
18846 	}
18847 	if (error) {
18848 		goto failed;
18849 	} else if (rack->rc_hw_nobuf && (ip_sendflag != IP_NO_SND_TAG_RL)) {
18850 		rack->rc_hw_nobuf = 0;
18851 		rack->r_ctl.rc_agg_delayed = 0;
18852 		rack->r_early = 0;
18853 		rack->r_late = 0;
18854 		rack->r_ctl.rc_agg_early = 0;
18855 	}
18856 
18857 	rack_log_output(tp, &to, len, rsm->r_start, flags, error, rack_to_usec_ts(tv),
18858 			rsm, RACK_SENT_FP, rsm->m, rsm->soff, rsm->r_hw_tls, segsiz);
18859 	if (doing_tlp) {
18860 		rack->rc_tlp_in_progress = 1;
18861 		rack->r_ctl.rc_tlp_cnt_out++;
18862 	}
18863 	if (error == 0) {
18864 		counter_u64_add(rack_total_bytes, len);
18865 		tcp_account_for_send(tp, len, 1, doing_tlp, rsm->r_hw_tls);
18866 		if (doing_tlp) {
18867 			rack->rc_last_sent_tlp_past_cumack = 0;
18868 			rack->rc_last_sent_tlp_seq_valid = 1;
18869 			rack->r_ctl.last_sent_tlp_seq = rsm->r_start;
18870 			rack->r_ctl.last_sent_tlp_len = rsm->r_end - rsm->r_start;
18871 		}
18872 	}
18873 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
18874 	rack->forced_ack = 0;	/* If we send something zap the FA flag */
18875 	if (IN_FASTRECOVERY(tp->t_flags) && rsm)
18876 		rack->r_ctl.retran_during_recovery += len;
18877 	{
18878 		int idx;
18879 
18880 		idx = (len / segsiz) + 3;
18881 		if (idx >= TCP_MSS_ACCT_ATIMER)
18882 			counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
18883 		else
18884 			counter_u64_add(rack_out_size[idx], 1);
18885 	}
18886 	if (tp->t_rtttime == 0) {
18887 		tp->t_rtttime = ticks;
18888 		tp->t_rtseq = startseq;
18889 		KMOD_TCPSTAT_INC(tcps_segstimed);
18890 	}
18891 	counter_u64_add(rack_fto_rsm_send, 1);
18892 	if (error && (error == ENOBUFS)) {
18893 		if (rack->r_ctl.crte != NULL) {
18894 			tcp_trace_point(rack->rc_tp, TCP_TP_HWENOBUF);
18895 			if (tcp_bblogging_on(rack->rc_tp))
18896 				rack_log_queue_level(tp, rack, len, tv, cts);
18897 		} else
18898 			tcp_trace_point(rack->rc_tp, TCP_TP_ENOBUF);
18899 		slot = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
18900 		if (rack->rc_enobuf < 0x7f)
18901 			rack->rc_enobuf++;
18902 		if (slot < (10 * HPTS_USEC_IN_MSEC))
18903 			slot = 10 * HPTS_USEC_IN_MSEC;
18904 		if (rack->r_ctl.crte != NULL) {
18905 			counter_u64_add(rack_saw_enobuf_hw, 1);
18906 			tcp_rl_log_enobuf(rack->r_ctl.crte);
18907 		}
18908 		counter_u64_add(rack_saw_enobuf, 1);
18909 	} else
18910 		slot = rack_get_pacing_delay(rack, tp, len, NULL, segsiz);
18911 	if ((slot == 0) ||
18912 	    (rack->rc_always_pace == 0) ||
18913 	    (rack->r_rr_config == 1)) {
18914 		/*
18915 		 * We have no pacing set or we
18916 		 * are using old-style rack or
18917 		 * we are overridden to use the old 1ms pacing.
18918 		 */
18919 		slot = rack->r_ctl.rc_min_to;
18920 	}
18921 	rack_start_hpts_timer(rack, tp, cts, slot, len, 0);
18922 #ifdef TCP_ACCOUNTING
18923 	crtsc = get_cyclecount();
18924 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18925 		tp->tcp_cnt_counters[SND_OUT_DATA] += cnt_thru;
18926 	}
18927 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18928 		tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
18929 	}
18930 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18931 		tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((len + segsiz - 1) / segsiz);
18932 	}
18933 	sched_unpin();
18934 #endif
18935 	return (0);
18936 failed:
18937 	if (m)
18938 		m_free(m);
18939 	return (-1);
18940 }
18941 
18942 static void
18943 rack_sndbuf_autoscale(struct tcp_rack *rack)
18944 {
18945 	/*
18946 	 * Automatic sizing of send socket buffer.  Often the send buffer
18947 	 * size is not optimally adjusted to the actual network conditions
18948 	 * at hand (delay bandwidth product).  Setting the buffer size too
18949 	 * small limits throughput on links with high bandwidth and high
18950 	 * delay (eg. trans-continental/oceanic links).  Setting the
18951 	 * buffer size too big consumes too much real kernel memory,
18952 	 * especially with many connections on busy servers.
18953 	 *
18954 	 * The criteria to step up the send buffer one notch are:
18955 	 *  1. receive window of remote host is larger than send buffer
18956 	 *     (with a fudge factor of 5/4th);
18957 	 *  2. send buffer is filled to 7/8th with data (so we actually
18958 	 *     have data to make use of it);
18959 	 *  3. send buffer fill has not hit maximal automatic size;
18960 	 *  4. our send window (slow start and cogestion controlled) is
18961 	 *     larger than sent but unacknowledged data in send buffer.
18962 	 *
18963 	 * Note that the rack version moves things much faster since
18964 	 * we want to avoid hitting cache lines in the rack_fast_output()
18965 	 * path so this is called much less often and thus moves
18966 	 * the SB forward by a percentage.
18967 	 */
18968 	struct socket *so;
18969 	struct tcpcb *tp;
18970 	uint32_t sendwin, scaleup;
18971 
18972 	tp = rack->rc_tp;
18973 	so = rack->rc_inp->inp_socket;
18974 	sendwin = min(rack->r_ctl.cwnd_to_use, tp->snd_wnd);
18975 	if (V_tcp_do_autosndbuf && so->so_snd.sb_flags & SB_AUTOSIZE) {
18976 		if ((tp->snd_wnd / 4 * 5) >= so->so_snd.sb_hiwat &&
18977 		    sbused(&so->so_snd) >=
18978 		    (so->so_snd.sb_hiwat / 8 * 7) &&
18979 		    sbused(&so->so_snd) < V_tcp_autosndbuf_max &&
18980 		    sendwin >= (sbused(&so->so_snd) -
18981 		    (tp->snd_nxt - tp->snd_una))) {
18982 			if (rack_autosndbuf_inc)
18983 				scaleup = (rack_autosndbuf_inc * so->so_snd.sb_hiwat) / 100;
18984 			else
18985 				scaleup = V_tcp_autosndbuf_inc;
18986 			if (scaleup < V_tcp_autosndbuf_inc)
18987 				scaleup = V_tcp_autosndbuf_inc;
18988 			scaleup += so->so_snd.sb_hiwat;
18989 			if (scaleup > V_tcp_autosndbuf_max)
18990 				scaleup = V_tcp_autosndbuf_max;
18991 			if (!sbreserve_locked(so, SO_SND, scaleup, curthread))
18992 				so->so_snd.sb_flags &= ~SB_AUTOSIZE;
18993 		}
18994 	}
18995 }
18996 
18997 static int
18998 rack_fast_output(struct tcpcb *tp, struct tcp_rack *rack, uint64_t ts_val,
18999 		 uint32_t cts, uint32_t ms_cts, struct timeval *tv, long tot_len, int *send_err)
19000 {
19001 	/*
19002 	 * Enter to do fast output. We are given that the sched_pin is
19003 	 * in place (if accounting is compiled in) and the cycle count taken
19004 	 * at entry is in place in ts_val. The idea here is that
19005 	 * we know how many more bytes needs to be sent (presumably either
19006 	 * during pacing or to fill the cwnd and that was greater than
19007 	 * the max-burst). We have how much to send and all the info we
19008 	 * need to just send.
19009 	 */
19010 #ifdef INET
19011 	struct ip *ip = NULL;
19012 #endif
19013 	struct udphdr *udp = NULL;
19014 	struct tcphdr *th = NULL;
19015 	struct mbuf *m, *s_mb;
19016 	struct inpcb *inp;
19017 	uint8_t *cpto;
19018 	struct tcp_log_buffer *lgb;
19019 #ifdef TCP_ACCOUNTING
19020 	uint64_t crtsc;
19021 #endif
19022 	struct tcpopt to;
19023 	u_char opt[TCP_MAXOLEN];
19024 	uint32_t hdrlen, optlen;
19025 #ifdef TCP_ACCOUNTING
19026 	int cnt_thru = 1;
19027 #endif
19028 	int32_t slot, segsiz, len, max_val, tso = 0, sb_offset, error, ulen = 0;
19029 	uint16_t flags;
19030 	uint32_t s_soff;
19031 	uint32_t if_hw_tsomaxsegcount = 0, startseq;
19032 	uint32_t if_hw_tsomaxsegsize;
19033 	uint16_t add_flag = RACK_SENT_FP;
19034 #ifdef INET6
19035 	struct ip6_hdr *ip6 = NULL;
19036 
19037 	if (rack->r_is_v6) {
19038 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
19039 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
19040 	} else
19041 #endif				/* INET6 */
19042 	{
19043 #ifdef INET
19044 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
19045 		hdrlen = sizeof(struct tcpiphdr);
19046 #endif
19047 	}
19048 	if (tp->t_port && (V_tcp_udp_tunneling_port == 0)) {
19049 		m = NULL;
19050 		goto failed;
19051 	}
19052 	startseq = tp->snd_max;
19053 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
19054 	inp = rack->rc_inp;
19055 	len = rack->r_ctl.fsb.left_to_send;
19056 	to.to_flags = 0;
19057 	flags = rack->r_ctl.fsb.tcp_flags;
19058 	if (tp->t_flags & TF_RCVD_TSTMP) {
19059 		to.to_tsval = ms_cts + tp->ts_offset;
19060 		to.to_tsecr = tp->ts_recent;
19061 		to.to_flags = TOF_TS;
19062 	}
19063 	optlen = tcp_addoptions(&to, opt);
19064 	hdrlen += optlen;
19065 	udp = rack->r_ctl.fsb.udp;
19066 	if (udp)
19067 		hdrlen += sizeof(struct udphdr);
19068 	if (rack->r_ctl.rc_pace_max_segs)
19069 		max_val = rack->r_ctl.rc_pace_max_segs;
19070 	else if (rack->rc_user_set_max_segs)
19071 		max_val = rack->rc_user_set_max_segs * segsiz;
19072 	else
19073 		max_val = len;
19074 	if ((tp->t_flags & TF_TSO) &&
19075 	    V_tcp_do_tso &&
19076 	    (len > segsiz) &&
19077 	    (tp->t_port == 0))
19078 		tso = 1;
19079 again:
19080 #ifdef INET6
19081 	if (MHLEN < hdrlen + max_linkhdr)
19082 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
19083 	else
19084 #endif
19085 		m = m_gethdr(M_NOWAIT, MT_DATA);
19086 	if (m == NULL)
19087 		goto failed;
19088 	m->m_data += max_linkhdr;
19089 	m->m_len = hdrlen;
19090 	th = rack->r_ctl.fsb.th;
19091 	/* Establish the len to send */
19092 	if (len > max_val)
19093 		len = max_val;
19094 	if ((tso) && (len + optlen > segsiz)) {
19095 		uint32_t if_hw_tsomax;
19096 		int32_t max_len;
19097 
19098 		/* extract TSO information */
19099 		if_hw_tsomax = tp->t_tsomax;
19100 		if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
19101 		if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
19102 		/*
19103 		 * Check if we should limit by maximum payload
19104 		 * length:
19105 		 */
19106 		if (if_hw_tsomax != 0) {
19107 			/* compute maximum TSO length */
19108 			max_len = (if_hw_tsomax - hdrlen -
19109 				   max_linkhdr);
19110 			if (max_len <= 0) {
19111 				goto failed;
19112 			} else if (len > max_len) {
19113 				len = max_len;
19114 			}
19115 		}
19116 		if (len <= segsiz) {
19117 			/*
19118 			 * In case there are too many small fragments don't
19119 			 * use TSO:
19120 			 */
19121 			tso = 0;
19122 		}
19123 	} else {
19124 		tso = 0;
19125 	}
19126 	if ((tso == 0) && (len > segsiz))
19127 		len = segsiz;
19128 	(void)tcp_get_usecs(tv);
19129 	if ((len == 0) ||
19130 	    (len <= MHLEN - hdrlen - max_linkhdr)) {
19131 		goto failed;
19132 	}
19133 	sb_offset = tp->snd_max - tp->snd_una;
19134 	th->th_seq = htonl(tp->snd_max);
19135 	th->th_ack = htonl(tp->rcv_nxt);
19136 	th->th_win = htons((u_short)(rack->r_ctl.fsb.recwin >> tp->rcv_scale));
19137 	if (th->th_win == 0) {
19138 		tp->t_sndzerowin++;
19139 		tp->t_flags |= TF_RXWIN0SENT;
19140 	} else
19141 		tp->t_flags &= ~TF_RXWIN0SENT;
19142 	tp->snd_up = tp->snd_una;	/* drag it along, its deprecated */
19143 	KMOD_TCPSTAT_INC(tcps_sndpack);
19144 	KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
19145 #ifdef STATS
19146 	stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
19147 				 len);
19148 #endif
19149 	if (rack->r_ctl.fsb.m == NULL)
19150 		goto failed;
19151 
19152 	/* s_mb and s_soff are saved for rack_log_output */
19153 	m->m_next = rack_fo_m_copym(rack, &len, if_hw_tsomaxsegcount, if_hw_tsomaxsegsize,
19154 				    &s_mb, &s_soff);
19155 	if (len <= segsiz) {
19156 		/*
19157 		 * Must have ran out of mbufs for the copy
19158 		 * shorten it to no longer need tso. Lets
19159 		 * not put on sendalot since we are low on
19160 		 * mbufs.
19161 		 */
19162 		tso = 0;
19163 	}
19164 	if (rack->r_ctl.fsb.rfo_apply_push &&
19165 	    (len == rack->r_ctl.fsb.left_to_send)) {
19166 		tcp_set_flags(th, flags | TH_PUSH);
19167 		add_flag |= RACK_HAD_PUSH;
19168 	}
19169 	if ((m->m_next == NULL) || (len <= 0)){
19170 		goto failed;
19171 	}
19172 	if (udp) {
19173 		if (rack->r_is_v6)
19174 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
19175 		else
19176 			ulen = hdrlen + len - sizeof(struct ip);
19177 		udp->uh_ulen = htons(ulen);
19178 	}
19179 	m->m_pkthdr.rcvif = (struct ifnet *)0;
19180 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
19181 	    (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))) {
19182 		int ect = tcp_ecn_output_established(tp, &flags, len, false);
19183 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
19184 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
19185 			tp->t_flags2 &= ~TF2_ECN_SND_ECE;
19186 #ifdef INET6
19187 		if (rack->r_is_v6) {
19188 			ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
19189 			ip6->ip6_flow |= htonl(ect << 20);
19190 		}
19191 		else
19192 #endif
19193 		{
19194 #ifdef INET
19195 			ip->ip_tos &= ~IPTOS_ECN_MASK;
19196 			ip->ip_tos |= ect;
19197 #endif
19198 		}
19199 	}
19200 	tcp_set_flags(th, flags);
19201 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
19202 #ifdef INET6
19203 	if (rack->r_is_v6) {
19204 		if (tp->t_port) {
19205 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
19206 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
19207 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
19208 			th->th_sum = htons(0);
19209 			UDPSTAT_INC(udps_opackets);
19210 		} else {
19211 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
19212 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
19213 			th->th_sum = in6_cksum_pseudo(ip6,
19214 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
19215 						      0);
19216 		}
19217 	}
19218 #endif
19219 #if defined(INET6) && defined(INET)
19220 	else
19221 #endif
19222 #ifdef INET
19223 	{
19224 		if (tp->t_port) {
19225 			m->m_pkthdr.csum_flags = CSUM_UDP;
19226 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
19227 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
19228 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
19229 			th->th_sum = htons(0);
19230 			UDPSTAT_INC(udps_opackets);
19231 		} else {
19232 			m->m_pkthdr.csum_flags = CSUM_TCP;
19233 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
19234 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
19235 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
19236 									IPPROTO_TCP + len + optlen));
19237 		}
19238 		/* IP version must be set here for ipv4/ipv6 checking later */
19239 		KASSERT(ip->ip_v == IPVERSION,
19240 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
19241 	}
19242 #endif
19243 	if (tso) {
19244 		/*
19245 		 * Here we use segsiz since we have no added options besides
19246 		 * any standard timestamp options (no DSACKs or SACKS are sent
19247 		 * via either fast-path).
19248 		 */
19249 		KASSERT(len > segsiz,
19250 			("%s: len <= tso_segsz tp:%p", __func__, tp));
19251 		m->m_pkthdr.csum_flags |= CSUM_TSO;
19252 		m->m_pkthdr.tso_segsz = segsiz;
19253 	}
19254 #ifdef INET6
19255 	if (rack->r_is_v6) {
19256 		ip6->ip6_hlim = rack->r_ctl.fsb.hoplimit;
19257 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
19258 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
19259 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
19260 		else
19261 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
19262 	}
19263 #endif
19264 #if defined(INET) && defined(INET6)
19265 	else
19266 #endif
19267 #ifdef INET
19268 	{
19269 		ip->ip_len = htons(m->m_pkthdr.len);
19270 		ip->ip_ttl = rack->r_ctl.fsb.hoplimit;
19271 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
19272 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
19273 			if (tp->t_port == 0 || len < V_tcp_minmss) {
19274 				ip->ip_off |= htons(IP_DF);
19275 			}
19276 		} else {
19277 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
19278 		}
19279 	}
19280 #endif
19281 	if (tp->snd_cwnd > tp->snd_ssthresh) {
19282 		/* Set we sent in CA */
19283 		rack->rc_gp_saw_ca = 1;
19284 	} else {
19285 		/* Set we sent in SS */
19286 		rack->rc_gp_saw_ss = 1;
19287 	}
19288 	/* Time to copy in our header */
19289 	cpto = mtod(m, uint8_t *);
19290 	memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
19291 	th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
19292 	if (optlen) {
19293 		bcopy(opt, th + 1, optlen);
19294 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
19295 	} else {
19296 		th->th_off = sizeof(struct tcphdr) >> 2;
19297 	}
19298 	if ((rack->r_ctl.crte != NULL) &&
19299 	    tcp_bblogging_on(tp)) {
19300 		rack_log_queue_level(tp, rack, len, tv, cts);
19301 	}
19302 	if (tcp_bblogging_on(rack->rc_tp)) {
19303 		union tcp_log_stackspecific log;
19304 
19305 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
19306 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
19307 		if (rack->rack_no_prr)
19308 			log.u_bbr.flex1 = 0;
19309 		else
19310 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
19311 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
19312 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
19313 		log.u_bbr.flex4 = max_val;
19314 		/* Save off the early/late values */
19315 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
19316 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
19317 		log.u_bbr.bw_inuse = rack_get_bw(rack);
19318 		log.u_bbr.cur_del_rate = rack->r_ctl.gp_bw;
19319 		log.u_bbr.flex8 = 0;
19320 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
19321 		log.u_bbr.flex7 = 44;
19322 		log.u_bbr.pkts_out = tp->t_maxseg;
19323 		log.u_bbr.timeStamp = cts;
19324 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
19325 		log.u_bbr.flex5 = log.u_bbr.inflight;
19326 		log.u_bbr.lt_epoch = rack->r_ctl.cwnd_to_use;
19327 		log.u_bbr.delivered = 0;
19328 		log.u_bbr.rttProp = 0;
19329 		log.u_bbr.delRate = rack->r_must_retran;
19330 		log.u_bbr.delRate <<= 1;
19331 		log.u_bbr.pkt_epoch = __LINE__;
19332 		/* For fast output no retrans so just inflight and how many mss we send */
19333 		log.u_bbr.flex5 = log.u_bbr.inflight;
19334 		log.u_bbr.bbr_substate = (uint8_t)((len + segsiz - 1)/segsiz);
19335 		lgb = tcp_log_event(tp, th, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
19336 				     len, &log, false, NULL, __func__, __LINE__, tv);
19337 	} else
19338 		lgb = NULL;
19339 #ifdef INET6
19340 	if (rack->r_is_v6) {
19341 		error = ip6_output(m, NULL,
19342 				   &inp->inp_route6,
19343 				   0, NULL, NULL, inp);
19344 	}
19345 #endif
19346 #if defined(INET) && defined(INET6)
19347 	else
19348 #endif
19349 #ifdef INET
19350 	{
19351 		error = ip_output(m, NULL,
19352 				  &inp->inp_route,
19353 				  0, 0, inp);
19354 	}
19355 #endif
19356 	if (lgb) {
19357 		lgb->tlb_errno = error;
19358 		lgb = NULL;
19359 	}
19360 	if (error) {
19361 		*send_err = error;
19362 		m = NULL;
19363 		goto failed;
19364 	} else if (rack->rc_hw_nobuf) {
19365 		rack->rc_hw_nobuf = 0;
19366 		rack->r_ctl.rc_agg_delayed = 0;
19367 		rack->r_early = 0;
19368 		rack->r_late = 0;
19369 		rack->r_ctl.rc_agg_early = 0;
19370 	}
19371 	if ((error == 0) && (rack->lt_bw_up == 0)) {
19372 		/* Unlikely */
19373 		rack->r_ctl.lt_timemark = tcp_tv_to_lusectick(tv);
19374 		rack->r_ctl.lt_seq = tp->snd_una;
19375 		rack->lt_bw_up = 1;
19376 	}
19377 	rack_log_output(tp, &to, len, tp->snd_max, flags, error, rack_to_usec_ts(tv),
19378 			NULL, add_flag, s_mb, s_soff, rack->r_ctl.fsb.hw_tls, segsiz);
19379 	m = NULL;
19380 	if (tp->snd_una == tp->snd_max) {
19381 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
19382 		rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
19383 		tp->t_acktime = ticks;
19384 	}
19385 	counter_u64_add(rack_total_bytes, len);
19386 	tcp_account_for_send(tp, len, 0, 0, rack->r_ctl.fsb.hw_tls);
19387 
19388 	rack->forced_ack = 0;	/* If we send something zap the FA flag */
19389 	tot_len += len;
19390 	if ((tp->t_flags & TF_GPUTINPROG) == 0)
19391 		rack_start_gp_measurement(tp, rack, tp->snd_max, sb_offset);
19392 	tp->snd_max += len;
19393 	tp->snd_nxt = tp->snd_max;
19394 	if (rack->rc_new_rnd_needed) {
19395 		/*
19396 		 * Update the rnd to start ticking not
19397 		 * that from a time perspective all of
19398 		 * the preceding idle time is "in the round"
19399 		 */
19400 		rack->rc_new_rnd_needed = 0;
19401 		rack->r_ctl.roundends = tp->snd_max;
19402 	}
19403 	{
19404 		int idx;
19405 
19406 		idx = (len / segsiz) + 3;
19407 		if (idx >= TCP_MSS_ACCT_ATIMER)
19408 			counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
19409 		else
19410 			counter_u64_add(rack_out_size[idx], 1);
19411 	}
19412 	if (len <= rack->r_ctl.fsb.left_to_send)
19413 		rack->r_ctl.fsb.left_to_send -= len;
19414 	else
19415 		rack->r_ctl.fsb.left_to_send = 0;
19416 	if (rack->r_ctl.fsb.left_to_send < segsiz) {
19417 		rack->r_fast_output = 0;
19418 		rack->r_ctl.fsb.left_to_send = 0;
19419 		/* At the end of fast_output scale up the sb */
19420 		SOCKBUF_LOCK(&rack->rc_inp->inp_socket->so_snd);
19421 		rack_sndbuf_autoscale(rack);
19422 		SOCKBUF_UNLOCK(&rack->rc_inp->inp_socket->so_snd);
19423 	}
19424 	if (tp->t_rtttime == 0) {
19425 		tp->t_rtttime = ticks;
19426 		tp->t_rtseq = startseq;
19427 		KMOD_TCPSTAT_INC(tcps_segstimed);
19428 	}
19429 	if ((rack->r_ctl.fsb.left_to_send >= segsiz) &&
19430 	    (max_val > len) &&
19431 	    (tso == 0)) {
19432 		max_val -= len;
19433 		len = segsiz;
19434 		th = rack->r_ctl.fsb.th;
19435 #ifdef TCP_ACCOUNTING
19436 		cnt_thru++;
19437 #endif
19438 		goto again;
19439 	}
19440 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
19441 	counter_u64_add(rack_fto_send, 1);
19442 	slot = rack_get_pacing_delay(rack, tp, tot_len, NULL, segsiz);
19443 	rack_start_hpts_timer(rack, tp, cts, slot, tot_len, 0);
19444 #ifdef TCP_ACCOUNTING
19445 	crtsc = get_cyclecount();
19446 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19447 		tp->tcp_cnt_counters[SND_OUT_DATA] += cnt_thru;
19448 	}
19449 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19450 		tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
19451 	}
19452 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19453 		tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len + segsiz - 1) / segsiz);
19454 	}
19455 	sched_unpin();
19456 #endif
19457 	return (0);
19458 failed:
19459 	if (m)
19460 		m_free(m);
19461 	rack->r_fast_output = 0;
19462 	return (-1);
19463 }
19464 
19465 static inline void
19466 rack_setup_fast_output(struct tcpcb *tp, struct tcp_rack *rack,
19467 		       struct sockbuf *sb,
19468 		       int len, int orig_len, int segsiz, uint32_t pace_max_seg,
19469 		       bool hw_tls,
19470 		       uint16_t flags)
19471 {
19472 	rack->r_fast_output = 1;
19473 	rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
19474 	rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
19475 	rack->r_ctl.fsb.o_t_len = M_TRAILINGROOM(rack->r_ctl.fsb.m);
19476 	rack->r_ctl.fsb.tcp_flags = flags;
19477 	rack->r_ctl.fsb.left_to_send = orig_len - len;
19478 	if (rack->r_ctl.fsb.left_to_send < pace_max_seg) {
19479 		/* Less than a full sized pace, lets not  */
19480 		rack->r_fast_output = 0;
19481 		return;
19482 	} else {
19483 		/* Round down to the nearest pace_max_seg */
19484 		rack->r_ctl.fsb.left_to_send = rounddown(rack->r_ctl.fsb.left_to_send, pace_max_seg);
19485 	}
19486 	if (hw_tls)
19487 		rack->r_ctl.fsb.hw_tls = 1;
19488 	else
19489 		rack->r_ctl.fsb.hw_tls = 0;
19490 	KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
19491 		("rack:%p left_to_send:%u sbavail:%u out:%u",
19492 		 rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
19493 		 (tp->snd_max - tp->snd_una)));
19494 	if (rack->r_ctl.fsb.left_to_send < segsiz)
19495 		rack->r_fast_output = 0;
19496 	else {
19497 		if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
19498 			rack->r_ctl.fsb.rfo_apply_push = 1;
19499 		else
19500 			rack->r_ctl.fsb.rfo_apply_push = 0;
19501 	}
19502 }
19503 
19504 static uint32_t
19505 rack_get_hpts_pacing_min_for_bw(struct tcp_rack *rack, int32_t segsiz)
19506 {
19507 	uint64_t min_time;
19508 	uint32_t maxlen;
19509 
19510 	min_time = (uint64_t)get_hpts_min_sleep_time();
19511 	maxlen = (uint32_t)((rack->r_ctl.gp_bw * min_time) / (uint64_t)HPTS_USEC_IN_SEC);
19512 	maxlen = roundup(maxlen, segsiz);
19513 	return (maxlen);
19514 }
19515 
19516 static struct rack_sendmap *
19517 rack_check_collapsed(struct tcp_rack *rack, uint32_t cts)
19518 {
19519 	struct rack_sendmap *rsm = NULL;
19520 	int thresh;
19521 
19522 restart:
19523 	rsm = tqhash_find(rack->r_ctl.tqh, rack->r_ctl.last_collapse_point);
19524 	if ((rsm == NULL) || ((rsm->r_flags & RACK_RWND_COLLAPSED) == 0)) {
19525 		/* Nothing, strange turn off validity  */
19526 		rack->r_collapse_point_valid = 0;
19527 		return (NULL);
19528 	}
19529 	/* Can we send it yet? */
19530 	if (rsm->r_end > (rack->rc_tp->snd_una + rack->rc_tp->snd_wnd)) {
19531 		/*
19532 		 * Receiver window has not grown enough for
19533 		 * the segment to be put on the wire.
19534 		 */
19535 		return (NULL);
19536 	}
19537 	if (rsm->r_flags & RACK_ACKED) {
19538 		/*
19539 		 * It has been sacked, lets move to the
19540 		 * next one if possible.
19541 		 */
19542 		rack->r_ctl.last_collapse_point = rsm->r_end;
19543 		/* Are we done? */
19544 		if (SEQ_GEQ(rack->r_ctl.last_collapse_point,
19545 			    rack->r_ctl.high_collapse_point)) {
19546 			rack->r_collapse_point_valid = 0;
19547 			return (NULL);
19548 		}
19549 		goto restart;
19550 	}
19551 	/* Now has it been long enough ? */
19552 	thresh = rack_calc_thresh_rack(rack, rack_grab_rtt(rack->rc_tp, rack), cts);
19553 	if ((cts - ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)])) > thresh) {
19554 		rack_log_collapse(rack, rsm->r_start,
19555 				  (cts - ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)])),
19556 				  thresh, __LINE__, 6, rsm->r_flags, rsm);
19557 		return (rsm);
19558 	}
19559 	/* Not enough time */
19560 	rack_log_collapse(rack, rsm->r_start,
19561 			  (cts - ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)])),
19562 			  thresh, __LINE__, 7, rsm->r_flags, rsm);
19563 	return (NULL);
19564 }
19565 
19566 static inline void
19567 rack_validate_sizes(struct tcp_rack *rack, int32_t *len, int32_t segsiz, uint32_t pace_max_seg)
19568 {
19569 	if ((rack->full_size_rxt == 0) &&
19570 	    (rack->shape_rxt_to_pacing_min == 0) &&
19571 	    (*len >= segsiz)) {
19572 		*len = segsiz;
19573 	} else if (rack->shape_rxt_to_pacing_min &&
19574 		 rack->gp_ready) {
19575 		/* We use pacing min as shaping len req */
19576 		uint32_t maxlen;
19577 
19578 		maxlen = rack_get_hpts_pacing_min_for_bw(rack, segsiz);
19579 		if (*len > maxlen)
19580 			*len = maxlen;
19581 	} else {
19582 		/*
19583 		 * The else is full_size_rxt is on so send it all
19584 		 * note we do need to check this for exceeding
19585 		 * our max segment size due to the fact that
19586 		 * we do sometimes merge chunks together i.e.
19587 		 * we cannot just assume that we will never have
19588 		 * a chunk greater than pace_max_seg
19589 		 */
19590 		if (*len > pace_max_seg)
19591 			*len = pace_max_seg;
19592 	}
19593 }
19594 
19595 static int
19596 rack_output(struct tcpcb *tp)
19597 {
19598 	struct socket *so;
19599 	uint32_t recwin;
19600 	uint32_t sb_offset, s_moff = 0;
19601 	int32_t len, error = 0;
19602 	uint16_t flags;
19603 	struct mbuf *m, *s_mb = NULL;
19604 	struct mbuf *mb;
19605 	uint32_t if_hw_tsomaxsegcount = 0;
19606 	uint32_t if_hw_tsomaxsegsize;
19607 	int32_t segsiz, minseg;
19608 	long tot_len_this_send = 0;
19609 #ifdef INET
19610 	struct ip *ip = NULL;
19611 #endif
19612 	struct udphdr *udp = NULL;
19613 	struct tcp_rack *rack;
19614 	struct tcphdr *th;
19615 	uint8_t pass = 0;
19616 	uint8_t mark = 0;
19617 	uint8_t check_done = 0;
19618 	uint8_t wanted_cookie = 0;
19619 	u_char opt[TCP_MAXOLEN];
19620 	unsigned ipoptlen, optlen, hdrlen, ulen=0;
19621 	uint32_t rack_seq;
19622 
19623 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
19624 	unsigned ipsec_optlen = 0;
19625 
19626 #endif
19627 	int32_t idle, sendalot;
19628 	int32_t sub_from_prr = 0;
19629 	volatile int32_t sack_rxmit;
19630 	struct rack_sendmap *rsm = NULL;
19631 	int32_t tso, mtu;
19632 	struct tcpopt to;
19633 	int32_t slot = 0;
19634 	int32_t sup_rack = 0;
19635 	uint32_t cts, ms_cts, delayed, early;
19636 	uint16_t add_flag = RACK_SENT_SP;
19637 	/* The doing_tlp flag will be set by the actual rack_timeout_tlp() */
19638 	uint8_t doing_tlp = 0;
19639 	uint32_t cwnd_to_use, pace_max_seg;
19640 	int32_t do_a_prefetch = 0;
19641 	int32_t prefetch_rsm = 0;
19642 	int32_t orig_len = 0;
19643 	struct timeval tv;
19644 	int32_t prefetch_so_done = 0;
19645 	struct tcp_log_buffer *lgb;
19646 	struct inpcb *inp = tptoinpcb(tp);
19647 	struct sockbuf *sb;
19648 	uint64_t ts_val = 0;
19649 #ifdef TCP_ACCOUNTING
19650 	uint64_t crtsc;
19651 #endif
19652 #ifdef INET6
19653 	struct ip6_hdr *ip6 = NULL;
19654 	int32_t isipv6;
19655 #endif
19656 	bool hpts_calling, hw_tls = false;
19657 
19658 	NET_EPOCH_ASSERT();
19659 	INP_WLOCK_ASSERT(inp);
19660 
19661 	/* setup and take the cache hits here */
19662 	rack = (struct tcp_rack *)tp->t_fb_ptr;
19663 #ifdef TCP_ACCOUNTING
19664 	sched_pin();
19665 	ts_val = get_cyclecount();
19666 #endif
19667 	hpts_calling = !!(tp->t_flags2 & TF2_HPTS_CALLS);
19668 	tp->t_flags2 &= ~TF2_HPTS_CALLS;
19669 #ifdef TCP_OFFLOAD
19670 	if (tp->t_flags & TF_TOE) {
19671 #ifdef TCP_ACCOUNTING
19672 		sched_unpin();
19673 #endif
19674 		return (tcp_offload_output(tp));
19675 	}
19676 #endif
19677 	if (rack->rack_deferred_inited == 0) {
19678 		/*
19679 		 * If we are the connecting socket we will
19680 		 * hit rack_init() when no sequence numbers
19681 		 * are setup. This makes it so we must defer
19682 		 * some initialization. Call that now.
19683 		 */
19684 		rack_deferred_init(tp, rack);
19685 	}
19686 	/*
19687 	 * For TFO connections in SYN_RECEIVED, only allow the initial
19688 	 * SYN|ACK and those sent by the retransmit timer.
19689 	 */
19690 	if (IS_FASTOPEN(tp->t_flags) &&
19691 	    (tp->t_state == TCPS_SYN_RECEIVED) &&
19692 	    SEQ_GT(tp->snd_max, tp->snd_una) &&    /* initial SYN|ACK sent */
19693 	    (rack->r_ctl.rc_resend == NULL)) {         /* not a retransmit */
19694 #ifdef TCP_ACCOUNTING
19695 		sched_unpin();
19696 #endif
19697 		return (0);
19698 	}
19699 #ifdef INET6
19700 	if (rack->r_state) {
19701 		/* Use the cache line loaded if possible */
19702 		isipv6 = rack->r_is_v6;
19703 	} else {
19704 		isipv6 = (rack->rc_inp->inp_vflag & INP_IPV6) != 0;
19705 	}
19706 #endif
19707 	early = 0;
19708 	cts = tcp_get_usecs(&tv);
19709 	ms_cts = tcp_tv_to_mssectick(&tv);
19710 	if (((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) &&
19711 	    tcp_in_hpts(rack->rc_tp)) {
19712 		/*
19713 		 * We are on the hpts for some timer but not hptsi output.
19714 		 * Remove from the hpts unconditionally.
19715 		 */
19716 		rack_timer_cancel(tp, rack, cts, __LINE__);
19717 	}
19718 	/* Are we pacing and late? */
19719 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
19720 	    TSTMP_GEQ(cts, rack->r_ctl.rc_last_output_to)) {
19721 		/* We are delayed */
19722 		delayed = cts - rack->r_ctl.rc_last_output_to;
19723 	} else {
19724 		delayed = 0;
19725 	}
19726 	/* Do the timers, which may override the pacer */
19727 	if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
19728 		int retval;
19729 
19730 		retval = rack_process_timers(tp, rack, cts, hpts_calling,
19731 					     &doing_tlp);
19732 		if (retval != 0) {
19733 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_ATIMER], 1);
19734 #ifdef TCP_ACCOUNTING
19735 			sched_unpin();
19736 #endif
19737 			/*
19738 			 * If timers want tcp_drop(), then pass error out,
19739 			 * otherwise suppress it.
19740 			 */
19741 			return (retval < 0 ? retval : 0);
19742 		}
19743 	}
19744 	if (rack->rc_in_persist) {
19745 		if (tcp_in_hpts(rack->rc_tp) == 0) {
19746 			/* Timer is not running */
19747 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
19748 		}
19749 #ifdef TCP_ACCOUNTING
19750 		sched_unpin();
19751 #endif
19752 		return (0);
19753 	}
19754 	if ((rack->rc_ack_required == 1) &&
19755 	    (rack->r_timer_override == 0)){
19756 		/* A timeout occurred and no ack has arrived */
19757 		if (tcp_in_hpts(rack->rc_tp) == 0) {
19758 			/* Timer is not running */
19759 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
19760 		}
19761 #ifdef TCP_ACCOUNTING
19762 		sched_unpin();
19763 #endif
19764 		return (0);
19765 	}
19766 	if ((rack->r_timer_override) ||
19767 	    (rack->rc_ack_can_sendout_data) ||
19768 	    (delayed) ||
19769 	    (tp->t_state < TCPS_ESTABLISHED)) {
19770 		rack->rc_ack_can_sendout_data = 0;
19771 		if (tcp_in_hpts(rack->rc_tp))
19772 			tcp_hpts_remove(rack->rc_tp);
19773 	} else if (tcp_in_hpts(rack->rc_tp)) {
19774 		/*
19775 		 * On the hpts you can't pass even if ACKNOW is on, we will
19776 		 * when the hpts fires.
19777 		 */
19778 #ifdef TCP_ACCOUNTING
19779 		crtsc = get_cyclecount();
19780 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19781 			tp->tcp_proc_time[SND_BLOCKED] += (crtsc - ts_val);
19782 		}
19783 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19784 			tp->tcp_cnt_counters[SND_BLOCKED]++;
19785 		}
19786 		sched_unpin();
19787 #endif
19788 		counter_u64_add(rack_out_size[TCP_MSS_ACCT_INPACE], 1);
19789 		return (0);
19790 	}
19791 	/* Finish out both pacing early and late accounting */
19792 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
19793 	    TSTMP_GT(rack->r_ctl.rc_last_output_to, cts)) {
19794 		early = rack->r_ctl.rc_last_output_to - cts;
19795 	} else
19796 		early = 0;
19797 	if (delayed) {
19798 		rack->r_ctl.rc_agg_delayed += delayed;
19799 		rack->r_late = 1;
19800 	} else if (early) {
19801 		rack->r_ctl.rc_agg_early += early;
19802 		rack->r_early = 1;
19803 	}
19804 	/* Now that early/late accounting is done turn off the flag */
19805 	rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
19806 	rack->r_wanted_output = 0;
19807 	rack->r_timer_override = 0;
19808 	if ((tp->t_state != rack->r_state) &&
19809 	    TCPS_HAVEESTABLISHED(tp->t_state)) {
19810 		rack_set_state(tp, rack);
19811 	}
19812 	if ((rack->r_fast_output) &&
19813 	    (doing_tlp == 0) &&
19814 	    (tp->rcv_numsacks == 0)) {
19815 		int ret;
19816 
19817 		error = 0;
19818 		ret = rack_fast_output(tp, rack, ts_val, cts, ms_cts, &tv, tot_len_this_send, &error);
19819 		if (ret >= 0)
19820 			return(ret);
19821 		else if (error) {
19822 			inp = rack->rc_inp;
19823 			so = inp->inp_socket;
19824 			sb = &so->so_snd;
19825 			goto nomore;
19826 		}
19827 	}
19828 	inp = rack->rc_inp;
19829 	/*
19830 	 * For TFO connections in SYN_SENT or SYN_RECEIVED,
19831 	 * only allow the initial SYN or SYN|ACK and those sent
19832 	 * by the retransmit timer.
19833 	 */
19834 	if (IS_FASTOPEN(tp->t_flags) &&
19835 	    ((tp->t_state == TCPS_SYN_RECEIVED) ||
19836 	     (tp->t_state == TCPS_SYN_SENT)) &&
19837 	    SEQ_GT(tp->snd_max, tp->snd_una) && /* initial SYN or SYN|ACK sent */
19838 	    (tp->t_rxtshift == 0)) {              /* not a retransmit */
19839 		cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
19840 		so = inp->inp_socket;
19841 		sb = &so->so_snd;
19842 		goto just_return_nolock;
19843 	}
19844 	/*
19845 	 * Determine length of data that should be transmitted, and flags
19846 	 * that will be used. If there is some data or critical controls
19847 	 * (SYN, RST) to send, then transmit; otherwise, investigate
19848 	 * further.
19849 	 */
19850 	idle = (tp->t_flags & TF_LASTIDLE) || (tp->snd_max == tp->snd_una);
19851 	if (tp->t_idle_reduce) {
19852 		if (idle && (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur))
19853 			rack_cc_after_idle(rack, tp);
19854 	}
19855 	tp->t_flags &= ~TF_LASTIDLE;
19856 	if (idle) {
19857 		if (tp->t_flags & TF_MORETOCOME) {
19858 			tp->t_flags |= TF_LASTIDLE;
19859 			idle = 0;
19860 		}
19861 	}
19862 	if ((tp->snd_una == tp->snd_max) &&
19863 	    rack->r_ctl.rc_went_idle_time &&
19864 	    TSTMP_GT(cts, rack->r_ctl.rc_went_idle_time)) {
19865 		idle = cts - rack->r_ctl.rc_went_idle_time;
19866 		if (idle > rack_min_probertt_hold) {
19867 			/* Count as a probe rtt */
19868 			if (rack->in_probe_rtt == 0) {
19869 				rack->r_ctl.rc_lower_rtt_us_cts = cts;
19870 				rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
19871 				rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
19872 				rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
19873 			} else {
19874 				rack_exit_probertt(rack, cts);
19875 			}
19876 		}
19877 		idle = 0;
19878 	}
19879 	if (rack_use_fsb &&
19880 	    (rack->r_ctl.fsb.tcp_ip_hdr) &&
19881 	    (rack->r_fsb_inited == 0) &&
19882 	    (rack->r_state != TCPS_CLOSED))
19883 		rack_init_fsb_block(tp, rack, tcp_outflags[tp->t_state]);
19884 again:
19885 	/*
19886 	 * If we've recently taken a timeout, snd_max will be greater than
19887 	 * snd_nxt.  There may be SACK information that allows us to avoid
19888 	 * resending already delivered data.  Adjust snd_nxt accordingly.
19889 	 */
19890 	sendalot = 0;
19891 	cts = tcp_get_usecs(&tv);
19892 	ms_cts = tcp_tv_to_mssectick(&tv);
19893 	tso = 0;
19894 	mtu = 0;
19895 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
19896 	minseg = segsiz;
19897 	if (rack->r_ctl.rc_pace_max_segs == 0)
19898 		pace_max_seg = rack->rc_user_set_max_segs * segsiz;
19899 	else
19900 		pace_max_seg = rack->r_ctl.rc_pace_max_segs;
19901 	sb_offset = tp->snd_max - tp->snd_una;
19902 	cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
19903 	flags = tcp_outflags[tp->t_state];
19904 	while (rack->rc_free_cnt < rack_free_cache) {
19905 		rsm = rack_alloc(rack);
19906 		if (rsm == NULL) {
19907 			if (hpts_calling)
19908 				/* Retry in a ms */
19909 				slot = (1 * HPTS_USEC_IN_MSEC);
19910 			so = inp->inp_socket;
19911 			sb = &so->so_snd;
19912 			goto just_return_nolock;
19913 		}
19914 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_free, rsm, r_tnext);
19915 		rack->rc_free_cnt++;
19916 		rsm = NULL;
19917 	}
19918 	sack_rxmit = 0;
19919 	len = 0;
19920 	rsm = NULL;
19921 	if (flags & TH_RST) {
19922 		SOCKBUF_LOCK(&inp->inp_socket->so_snd);
19923 		so = inp->inp_socket;
19924 		sb = &so->so_snd;
19925 		goto send;
19926 	}
19927 	if (rack->r_ctl.rc_resend) {
19928 		/* Retransmit timer */
19929 		rsm = rack->r_ctl.rc_resend;
19930 		rack->r_ctl.rc_resend = NULL;
19931 		len = rsm->r_end - rsm->r_start;
19932 		sack_rxmit = 1;
19933 		sendalot = 0;
19934 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
19935 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
19936 			 __func__, __LINE__,
19937 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
19938 		sb_offset = rsm->r_start - tp->snd_una;
19939 		rack_validate_sizes(rack, &len, segsiz, pace_max_seg);
19940 	} else if (rack->r_collapse_point_valid &&
19941 		   ((rsm = rack_check_collapsed(rack, cts)) != NULL)) {
19942 		/*
19943 		 * If an RSM is returned then enough time has passed
19944 		 * for us to retransmit it. Move up the collapse point,
19945 		 * since this rsm has its chance to retransmit now.
19946 		 */
19947 		tcp_trace_point(rack->rc_tp, TCP_TP_COLLAPSED_RXT);
19948 		rack->r_ctl.last_collapse_point = rsm->r_end;
19949 		/* Are we done? */
19950 		if (SEQ_GEQ(rack->r_ctl.last_collapse_point,
19951 			    rack->r_ctl.high_collapse_point))
19952 			rack->r_collapse_point_valid = 0;
19953 		sack_rxmit = 1;
19954 		/* We are not doing a TLP */
19955 		doing_tlp = 0;
19956 		len = rsm->r_end - rsm->r_start;
19957 		sb_offset = rsm->r_start - tp->snd_una;
19958 		sendalot = 0;
19959 		rack_validate_sizes(rack, &len, segsiz, pace_max_seg);
19960 	} else if ((rsm = tcp_rack_output(tp, rack, cts)) != NULL) {
19961 		/* We have a retransmit that takes precedence */
19962 		if ((!IN_FASTRECOVERY(tp->t_flags)) &&
19963 		    ((rsm->r_flags & RACK_MUST_RXT) == 0) &&
19964 		    ((tp->t_flags & TF_WASFRECOVERY) == 0)) {
19965 			/* Enter recovery if not induced by a time-out */
19966 			rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
19967 		}
19968 #ifdef INVARIANTS
19969 		if (SEQ_LT(rsm->r_start, tp->snd_una)) {
19970 			panic("Huh, tp:%p rack:%p rsm:%p start:%u < snd_una:%u\n",
19971 			      tp, rack, rsm, rsm->r_start, tp->snd_una);
19972 		}
19973 #endif
19974 		len = rsm->r_end - rsm->r_start;
19975 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
19976 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
19977 			 __func__, __LINE__,
19978 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
19979 		sb_offset = rsm->r_start - tp->snd_una;
19980 		sendalot = 0;
19981 		rack_validate_sizes(rack, &len, segsiz, pace_max_seg);
19982 		if (len > 0) {
19983 			sack_rxmit = 1;
19984 			KMOD_TCPSTAT_INC(tcps_sack_rexmits);
19985 			KMOD_TCPSTAT_ADD(tcps_sack_rexmit_bytes,
19986 					 min(len, segsiz));
19987 		}
19988 	} else if (rack->r_ctl.rc_tlpsend) {
19989 		/* Tail loss probe */
19990 		long cwin;
19991 		long tlen;
19992 
19993 		/*
19994 		 * Check if we can do a TLP with a RACK'd packet
19995 		 * this can happen if we are not doing the rack
19996 		 * cheat and we skipped to a TLP and it
19997 		 * went off.
19998 		 */
19999 		rsm = rack->r_ctl.rc_tlpsend;
20000 		/* We are doing a TLP make sure the flag is preent */
20001 		rsm->r_flags |= RACK_TLP;
20002 		rack->r_ctl.rc_tlpsend = NULL;
20003 		sack_rxmit = 1;
20004 		tlen = rsm->r_end - rsm->r_start;
20005 		if (tlen > segsiz)
20006 			tlen = segsiz;
20007 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
20008 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
20009 			 __func__, __LINE__,
20010 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
20011 		sb_offset = rsm->r_start - tp->snd_una;
20012 		cwin = min(tp->snd_wnd, tlen);
20013 		len = cwin;
20014 	}
20015 	if (rack->r_must_retran &&
20016 	    (doing_tlp == 0) &&
20017 	    (SEQ_GT(tp->snd_max, tp->snd_una)) &&
20018 	    (rsm == NULL)) {
20019 		/*
20020 		 * There are two different ways that we
20021 		 * can get into this block:
20022 		 * a) This is a non-sack connection, we had a time-out
20023 		 *    and thus r_must_retran was set and everything
20024 		 *    left outstanding as been marked for retransmit.
20025 		 * b) The MTU of the path shrank, so that everything
20026 		 *    was marked to be retransmitted with the smaller
20027 		 *    mtu and r_must_retran was set.
20028 		 *
20029 		 * This means that we expect the sendmap (outstanding)
20030 		 * to all be marked must. We can use the tmap to
20031 		 * look at them.
20032 		 *
20033 		 */
20034 		int sendwin, flight;
20035 
20036 		sendwin = min(tp->snd_wnd, tp->snd_cwnd);
20037 		flight = ctf_flight_size(tp, rack->r_ctl.rc_out_at_rto);
20038 		if (flight >= sendwin) {
20039 			/*
20040 			 * We can't send yet.
20041 			 */
20042 			so = inp->inp_socket;
20043 			sb = &so->so_snd;
20044 			goto just_return_nolock;
20045 		}
20046 		/*
20047 		 * This is the case a/b mentioned above. All
20048 		 * outstanding/not-acked should be marked.
20049 		 * We can use the tmap to find them.
20050 		 */
20051 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
20052 		if (rsm == NULL) {
20053 			/* TSNH */
20054 			rack->r_must_retran = 0;
20055 			rack->r_ctl.rc_out_at_rto = 0;
20056 			so = inp->inp_socket;
20057 			sb = &so->so_snd;
20058 			goto just_return_nolock;
20059 		}
20060 		if ((rsm->r_flags & RACK_MUST_RXT) == 0) {
20061 			/*
20062 			 * The first one does not have the flag, did we collapse
20063 			 * further up in our list?
20064 			 */
20065 			rack->r_must_retran = 0;
20066 			rack->r_ctl.rc_out_at_rto = 0;
20067 			rsm = NULL;
20068 			sack_rxmit = 0;
20069 		} else {
20070 			sack_rxmit = 1;
20071 			len = rsm->r_end - rsm->r_start;
20072 			sb_offset = rsm->r_start - tp->snd_una;
20073 			sendalot = 0;
20074 			if ((rack->full_size_rxt == 0) &&
20075 			    (rack->shape_rxt_to_pacing_min == 0) &&
20076 			    (len >= segsiz))
20077 				len = segsiz;
20078 			else if (rack->shape_rxt_to_pacing_min &&
20079 				 rack->gp_ready) {
20080 				/* We use pacing min as shaping len req */
20081 				uint32_t maxlen;
20082 
20083 				maxlen = rack_get_hpts_pacing_min_for_bw(rack, segsiz);
20084 				if (len > maxlen)
20085 					len = maxlen;
20086 			}
20087 			/*
20088 			 * Delay removing the flag RACK_MUST_RXT so
20089 			 * that the fastpath for retransmit will
20090 			 * work with this rsm.
20091 			 */
20092 		}
20093 	}
20094 	/*
20095 	 * Enforce a connection sendmap count limit if set
20096 	 * as long as we are not retransmiting.
20097 	 */
20098 	if ((rsm == NULL) &&
20099 	    (rack->do_detection == 0) &&
20100 	    (V_tcp_map_entries_limit > 0) &&
20101 	    (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
20102 		counter_u64_add(rack_to_alloc_limited, 1);
20103 		if (!rack->alloc_limit_reported) {
20104 			rack->alloc_limit_reported = 1;
20105 			counter_u64_add(rack_alloc_limited_conns, 1);
20106 		}
20107 		so = inp->inp_socket;
20108 		sb = &so->so_snd;
20109 		goto just_return_nolock;
20110 	}
20111 	if (rsm && (rsm->r_flags & RACK_HAS_FIN)) {
20112 		/* we are retransmitting the fin */
20113 		len--;
20114 		if (len) {
20115 			/*
20116 			 * When retransmitting data do *not* include the
20117 			 * FIN. This could happen from a TLP probe.
20118 			 */
20119 			flags &= ~TH_FIN;
20120 		}
20121 	}
20122 	if (rsm && rack->r_fsb_inited &&
20123 	    rack_use_rsm_rfo &&
20124 	    ((rsm->r_flags & RACK_HAS_FIN) == 0)) {
20125 		int ret;
20126 
20127 		ret = rack_fast_rsm_output(tp, rack, rsm, ts_val, cts, ms_cts, &tv, len, doing_tlp);
20128 		if (ret == 0)
20129 			return (0);
20130 	}
20131 	so = inp->inp_socket;
20132 	sb = &so->so_snd;
20133 	if (do_a_prefetch == 0) {
20134 		kern_prefetch(sb, &do_a_prefetch);
20135 		do_a_prefetch = 1;
20136 	}
20137 #ifdef NETFLIX_SHARED_CWND
20138 	if ((tp->t_flags2 & TF2_TCP_SCWND_ALLOWED) &&
20139 	    rack->rack_enable_scwnd) {
20140 		/* We are doing cwnd sharing */
20141 		if (rack->gp_ready &&
20142 		    (rack->rack_attempted_scwnd == 0) &&
20143 		    (rack->r_ctl.rc_scw == NULL) &&
20144 		    tp->t_lib) {
20145 			/* The pcbid is in, lets make an attempt */
20146 			counter_u64_add(rack_try_scwnd, 1);
20147 			rack->rack_attempted_scwnd = 1;
20148 			rack->r_ctl.rc_scw = tcp_shared_cwnd_alloc(tp,
20149 								   &rack->r_ctl.rc_scw_index,
20150 								   segsiz);
20151 		}
20152 		if (rack->r_ctl.rc_scw &&
20153 		    (rack->rack_scwnd_is_idle == 1) &&
20154 		    sbavail(&so->so_snd)) {
20155 			/* we are no longer out of data */
20156 			tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
20157 			rack->rack_scwnd_is_idle = 0;
20158 		}
20159 		if (rack->r_ctl.rc_scw) {
20160 			/* First lets update and get the cwnd */
20161 			rack->r_ctl.cwnd_to_use = cwnd_to_use = tcp_shared_cwnd_update(rack->r_ctl.rc_scw,
20162 										       rack->r_ctl.rc_scw_index,
20163 										       tp->snd_cwnd, tp->snd_wnd, segsiz);
20164 		}
20165 	}
20166 #endif
20167 	/*
20168 	 * Get standard flags, and add SYN or FIN if requested by 'hidden'
20169 	 * state flags.
20170 	 */
20171 	if (tp->t_flags & TF_NEEDFIN)
20172 		flags |= TH_FIN;
20173 	if (tp->t_flags & TF_NEEDSYN)
20174 		flags |= TH_SYN;
20175 	if ((sack_rxmit == 0) && (prefetch_rsm == 0)) {
20176 		void *end_rsm;
20177 		end_rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
20178 		if (end_rsm)
20179 			kern_prefetch(end_rsm, &prefetch_rsm);
20180 		prefetch_rsm = 1;
20181 	}
20182 	SOCKBUF_LOCK(sb);
20183 	/*
20184 	 * If snd_nxt == snd_max and we have transmitted a FIN, the
20185 	 * sb_offset will be > 0 even if so_snd.sb_cc is 0, resulting in a
20186 	 * negative length.  This can also occur when TCP opens up its
20187 	 * congestion window while receiving additional duplicate acks after
20188 	 * fast-retransmit because TCP will reset snd_nxt to snd_max after
20189 	 * the fast-retransmit.
20190 	 *
20191 	 * In the normal retransmit-FIN-only case, however, snd_nxt will be
20192 	 * set to snd_una, the sb_offset will be 0, and the length may wind
20193 	 * up 0.
20194 	 *
20195 	 * If sack_rxmit is true we are retransmitting from the scoreboard
20196 	 * in which case len is already set.
20197 	 */
20198 	if ((sack_rxmit == 0) &&
20199 	    (TCPS_HAVEESTABLISHED(tp->t_state) || IS_FASTOPEN(tp->t_flags))) {
20200 		uint32_t avail;
20201 
20202 		avail = sbavail(sb);
20203 		if (SEQ_GT(tp->snd_nxt, tp->snd_una) && avail)
20204 			sb_offset = tp->snd_nxt - tp->snd_una;
20205 		else
20206 			sb_offset = 0;
20207 		if ((IN_FASTRECOVERY(tp->t_flags) == 0) || rack->rack_no_prr) {
20208 			if (rack->r_ctl.rc_tlp_new_data) {
20209 				/* TLP is forcing out new data */
20210 				if (rack->r_ctl.rc_tlp_new_data > (uint32_t) (avail - sb_offset)) {
20211 					rack->r_ctl.rc_tlp_new_data = (uint32_t) (avail - sb_offset);
20212 				}
20213 				if ((rack->r_ctl.rc_tlp_new_data + sb_offset) > tp->snd_wnd) {
20214 					if (tp->snd_wnd > sb_offset)
20215 						len = tp->snd_wnd - sb_offset;
20216 					else
20217 						len = 0;
20218 				} else {
20219 					len = rack->r_ctl.rc_tlp_new_data;
20220 				}
20221 				rack->r_ctl.rc_tlp_new_data = 0;
20222 			}  else {
20223 				len = rack_what_can_we_send(tp, rack, cwnd_to_use, avail, sb_offset);
20224 			}
20225 			if ((rack->r_ctl.crte == NULL) &&
20226 			    IN_FASTRECOVERY(tp->t_flags) &&
20227 			    (rack->full_size_rxt == 0) &&
20228 			    (rack->shape_rxt_to_pacing_min == 0) &&
20229 			    (len > segsiz)) {
20230 				/*
20231 				 * For prr=off, we need to send only 1 MSS
20232 				 * at a time. We do this because another sack could
20233 				 * be arriving that causes us to send retransmits and
20234 				 * we don't want to be on a long pace due to a larger send
20235 				 * that keeps us from sending out the retransmit.
20236 				 */
20237 				len = segsiz;
20238 			} else if (rack->shape_rxt_to_pacing_min &&
20239 				   rack->gp_ready) {
20240 				/* We use pacing min as shaping len req */
20241 				uint32_t maxlen;
20242 
20243 				maxlen = rack_get_hpts_pacing_min_for_bw(rack, segsiz);
20244 				if (len > maxlen)
20245 					len = maxlen;
20246 			}/* The else is full_size_rxt is on so send it all */
20247 		} else {
20248 			uint32_t outstanding;
20249 			/*
20250 			 * We are inside of a Fast recovery episode, this
20251 			 * is caused by a SACK or 3 dup acks. At this point
20252 			 * we have sent all the retransmissions and we rely
20253 			 * on PRR to dictate what we will send in the form of
20254 			 * new data.
20255 			 */
20256 
20257 			outstanding = tp->snd_max - tp->snd_una;
20258 			if ((rack->r_ctl.rc_prr_sndcnt + outstanding) > tp->snd_wnd) {
20259 				if (tp->snd_wnd > outstanding) {
20260 					len = tp->snd_wnd - outstanding;
20261 					/* Check to see if we have the data */
20262 					if ((sb_offset + len) > avail) {
20263 						/* It does not all fit */
20264 						if (avail > sb_offset)
20265 							len = avail - sb_offset;
20266 						else
20267 							len = 0;
20268 					}
20269 				} else {
20270 					len = 0;
20271 				}
20272 			} else if (avail > sb_offset) {
20273 				len = avail - sb_offset;
20274 			} else {
20275 				len = 0;
20276 			}
20277 			if (len > 0) {
20278 				if (len > rack->r_ctl.rc_prr_sndcnt) {
20279 					len = rack->r_ctl.rc_prr_sndcnt;
20280 				}
20281 				if (len > 0) {
20282 					sub_from_prr = 1;
20283 				}
20284 			}
20285 			if (len > segsiz) {
20286 				/*
20287 				 * We should never send more than a MSS when
20288 				 * retransmitting or sending new data in prr
20289 				 * mode unless the override flag is on. Most
20290 				 * likely the PRR algorithm is not going to
20291 				 * let us send a lot as well :-)
20292 				 */
20293 				if (rack->r_ctl.rc_prr_sendalot == 0) {
20294 					len = segsiz;
20295 				}
20296 			} else if (len < segsiz) {
20297 				/*
20298 				 * Do we send any? The idea here is if the
20299 				 * send empty's the socket buffer we want to
20300 				 * do it. However if not then lets just wait
20301 				 * for our prr_sndcnt to get bigger.
20302 				 */
20303 				long leftinsb;
20304 
20305 				leftinsb = sbavail(sb) - sb_offset;
20306 				if (leftinsb > len) {
20307 					/* This send does not empty the sb */
20308 					len = 0;
20309 				}
20310 			}
20311 		}
20312 	} else if (!TCPS_HAVEESTABLISHED(tp->t_state)) {
20313 		/*
20314 		 * If you have not established
20315 		 * and are not doing FAST OPEN
20316 		 * no data please.
20317 		 */
20318 		if ((sack_rxmit == 0) &&
20319 		    (!IS_FASTOPEN(tp->t_flags))){
20320 			len = 0;
20321 			sb_offset = 0;
20322 		}
20323 	}
20324 	if (prefetch_so_done == 0) {
20325 		kern_prefetch(so, &prefetch_so_done);
20326 		prefetch_so_done = 1;
20327 	}
20328 	/*
20329 	 * Lop off SYN bit if it has already been sent.  However, if this is
20330 	 * SYN-SENT state and if segment contains data and if we don't know
20331 	 * that foreign host supports TAO, suppress sending segment.
20332 	 */
20333 	if ((flags & TH_SYN) && SEQ_GT(tp->snd_nxt, tp->snd_una) &&
20334 	    ((sack_rxmit == 0) && (tp->t_rxtshift == 0))) {
20335 		/*
20336 		 * When sending additional segments following a TFO SYN|ACK,
20337 		 * do not include the SYN bit.
20338 		 */
20339 		if (IS_FASTOPEN(tp->t_flags) &&
20340 		    (tp->t_state == TCPS_SYN_RECEIVED))
20341 			flags &= ~TH_SYN;
20342 	}
20343 	/*
20344 	 * Be careful not to send data and/or FIN on SYN segments. This
20345 	 * measure is needed to prevent interoperability problems with not
20346 	 * fully conformant TCP implementations.
20347 	 */
20348 	if ((flags & TH_SYN) && (tp->t_flags & TF_NOOPT)) {
20349 		len = 0;
20350 		flags &= ~TH_FIN;
20351 	}
20352 	/*
20353 	 * On TFO sockets, ensure no data is sent in the following cases:
20354 	 *
20355 	 *  - When retransmitting SYN|ACK on a passively-created socket
20356 	 *
20357 	 *  - When retransmitting SYN on an actively created socket
20358 	 *
20359 	 *  - When sending a zero-length cookie (cookie request) on an
20360 	 *    actively created socket
20361 	 *
20362 	 *  - When the socket is in the CLOSED state (RST is being sent)
20363 	 */
20364 	if (IS_FASTOPEN(tp->t_flags) &&
20365 	    (((flags & TH_SYN) && (tp->t_rxtshift > 0)) ||
20366 	     ((tp->t_state == TCPS_SYN_SENT) &&
20367 	      (tp->t_tfo_client_cookie_len == 0)) ||
20368 	     (flags & TH_RST))) {
20369 		sack_rxmit = 0;
20370 		len = 0;
20371 	}
20372 	/* Without fast-open there should never be data sent on a SYN */
20373 	if ((flags & TH_SYN) && (!IS_FASTOPEN(tp->t_flags))) {
20374 		tp->snd_nxt = tp->iss;
20375 		len = 0;
20376 	}
20377 	if ((len > segsiz) && (tcp_dsack_block_exists(tp))) {
20378 		/* We only send 1 MSS if we have a DSACK block */
20379 		add_flag |= RACK_SENT_W_DSACK;
20380 		len = segsiz;
20381 	}
20382 	orig_len = len;
20383 	if (len <= 0) {
20384 		/*
20385 		 * If FIN has been sent but not acked, but we haven't been
20386 		 * called to retransmit, len will be < 0.  Otherwise, window
20387 		 * shrank after we sent into it.  If window shrank to 0,
20388 		 * cancel pending retransmit, pull snd_nxt back to (closed)
20389 		 * window, and set the persist timer if it isn't already
20390 		 * going.  If the window didn't close completely, just wait
20391 		 * for an ACK.
20392 		 *
20393 		 * We also do a general check here to ensure that we will
20394 		 * set the persist timer when we have data to send, but a
20395 		 * 0-byte window. This makes sure the persist timer is set
20396 		 * even if the packet hits one of the "goto send" lines
20397 		 * below.
20398 		 */
20399 		len = 0;
20400 		if ((tp->snd_wnd == 0) &&
20401 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
20402 		    (tp->snd_una == tp->snd_max) &&
20403 		    (sb_offset < (int)sbavail(sb))) {
20404 			rack_enter_persist(tp, rack, cts, tp->snd_una);
20405 		}
20406 	} else if ((rsm == NULL) &&
20407 		   (doing_tlp == 0) &&
20408 		   (len < pace_max_seg)) {
20409 		/*
20410 		 * We are not sending a maximum sized segment for
20411 		 * some reason. Should we not send anything (think
20412 		 * sws or persists)?
20413 		 */
20414 		if ((tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
20415 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
20416 		    (len < minseg) &&
20417 		    (len < (int)(sbavail(sb) - sb_offset))) {
20418 			/*
20419 			 * Here the rwnd is less than
20420 			 * the minimum pacing size, this is not a retransmit,
20421 			 * we are established and
20422 			 * the send is not the last in the socket buffer
20423 			 * we send nothing, and we may enter persists
20424 			 * if nothing is outstanding.
20425 			 */
20426 			len = 0;
20427 			if (tp->snd_max == tp->snd_una) {
20428 				/*
20429 				 * Nothing out we can
20430 				 * go into persists.
20431 				 */
20432 				rack_enter_persist(tp, rack, cts, tp->snd_una);
20433 			}
20434 		} else if ((cwnd_to_use >= max(minseg, (segsiz * 4))) &&
20435 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
20436 			   (len < (int)(sbavail(sb) - sb_offset)) &&
20437 			   (len < minseg)) {
20438 			/*
20439 			 * Here we are not retransmitting, and
20440 			 * the cwnd is not so small that we could
20441 			 * not send at least a min size (rxt timer
20442 			 * not having gone off), We have 2 segments or
20443 			 * more already in flight, its not the tail end
20444 			 * of the socket buffer  and the cwnd is blocking
20445 			 * us from sending out a minimum pacing segment size.
20446 			 * Lets not send anything.
20447 			 */
20448 			len = 0;
20449 		} else if (((tp->snd_wnd - ctf_outstanding(tp)) <
20450 			    min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
20451 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
20452 			   (len < (int)(sbavail(sb) - sb_offset)) &&
20453 			   (TCPS_HAVEESTABLISHED(tp->t_state))) {
20454 			/*
20455 			 * Here we have a send window but we have
20456 			 * filled it up and we can't send another pacing segment.
20457 			 * We also have in flight more than 2 segments
20458 			 * and we are not completing the sb i.e. we allow
20459 			 * the last bytes of the sb to go out even if
20460 			 * its not a full pacing segment.
20461 			 */
20462 			len = 0;
20463 		} else if ((rack->r_ctl.crte != NULL) &&
20464 			   (tp->snd_wnd >= (pace_max_seg * max(1, rack_hw_rwnd_factor))) &&
20465 			   (cwnd_to_use >= (pace_max_seg + (4 * segsiz))) &&
20466 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) >= (2 * segsiz)) &&
20467 			   (len < (int)(sbavail(sb) - sb_offset))) {
20468 			/*
20469 			 * Here we are doing hardware pacing, this is not a TLP,
20470 			 * we are not sending a pace max segment size, there is rwnd
20471 			 * room to send at least N pace_max_seg, the cwnd is greater
20472 			 * than or equal to a full pacing segments plus 4 mss and we have 2 or
20473 			 * more segments in flight and its not the tail of the socket buffer.
20474 			 *
20475 			 * We don't want to send instead we need to get more ack's in to
20476 			 * allow us to send a full pacing segment. Normally, if we are pacing
20477 			 * about the right speed, we should have finished our pacing
20478 			 * send as most of the acks have come back if we are at the
20479 			 * right rate. This is a bit fuzzy since return path delay
20480 			 * can delay the acks, which is why we want to make sure we
20481 			 * have cwnd space to have a bit more than a max pace segments in flight.
20482 			 *
20483 			 * If we have not gotten our acks back we are pacing at too high a
20484 			 * rate delaying will not hurt and will bring our GP estimate down by
20485 			 * injecting the delay. If we don't do this we will send
20486 			 * 2 MSS out in response to the acks being clocked in which
20487 			 * defeats the point of hw-pacing (i.e. to help us get
20488 			 * larger TSO's out).
20489 			 */
20490 			len = 0;
20491 		}
20492 
20493 	}
20494 	/* len will be >= 0 after this point. */
20495 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
20496 	rack_sndbuf_autoscale(rack);
20497 	/*
20498 	 * Decide if we can use TCP Segmentation Offloading (if supported by
20499 	 * hardware).
20500 	 *
20501 	 * TSO may only be used if we are in a pure bulk sending state.  The
20502 	 * presence of TCP-MD5, SACK retransmits, SACK advertizements and IP
20503 	 * options prevent using TSO.  With TSO the TCP header is the same
20504 	 * (except for the sequence number) for all generated packets.  This
20505 	 * makes it impossible to transmit any options which vary per
20506 	 * generated segment or packet.
20507 	 *
20508 	 * IPv4 handling has a clear separation of ip options and ip header
20509 	 * flags while IPv6 combines both in in6p_outputopts. ip6_optlen() does
20510 	 * the right thing below to provide length of just ip options and thus
20511 	 * checking for ipoptlen is enough to decide if ip options are present.
20512 	 */
20513 	ipoptlen = 0;
20514 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
20515 	/*
20516 	 * Pre-calculate here as we save another lookup into the darknesses
20517 	 * of IPsec that way and can actually decide if TSO is ok.
20518 	 */
20519 #ifdef INET6
20520 	if (isipv6 && IPSEC_ENABLED(ipv6))
20521 		ipsec_optlen = IPSEC_HDRSIZE(ipv6, inp);
20522 #ifdef INET
20523 	else
20524 #endif
20525 #endif				/* INET6 */
20526 #ifdef INET
20527 		if (IPSEC_ENABLED(ipv4))
20528 			ipsec_optlen = IPSEC_HDRSIZE(ipv4, inp);
20529 #endif				/* INET */
20530 #endif
20531 
20532 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
20533 	ipoptlen += ipsec_optlen;
20534 #endif
20535 	if ((tp->t_flags & TF_TSO) && V_tcp_do_tso && len > segsiz &&
20536 	    (tp->t_port == 0) &&
20537 	    ((tp->t_flags & TF_SIGNATURE) == 0) &&
20538 	    tp->rcv_numsacks == 0 && sack_rxmit == 0 &&
20539 	    ipoptlen == 0)
20540 		tso = 1;
20541 	{
20542 		uint32_t outstanding __unused;
20543 
20544 		outstanding = tp->snd_max - tp->snd_una;
20545 		if (tp->t_flags & TF_SENTFIN) {
20546 			/*
20547 			 * If we sent a fin, snd_max is 1 higher than
20548 			 * snd_una
20549 			 */
20550 			outstanding--;
20551 		}
20552 		if (sack_rxmit) {
20553 			if ((rsm->r_flags & RACK_HAS_FIN) == 0)
20554 				flags &= ~TH_FIN;
20555 		} else {
20556 			if (SEQ_LT(tp->snd_nxt + len, tp->snd_una +
20557 				   sbused(sb)))
20558 				flags &= ~TH_FIN;
20559 		}
20560 	}
20561 	recwin = lmin(lmax(sbspace(&so->so_rcv), 0),
20562 		      (long)TCP_MAXWIN << tp->rcv_scale);
20563 
20564 	/*
20565 	 * Sender silly window avoidance.   We transmit under the following
20566 	 * conditions when len is non-zero:
20567 	 *
20568 	 * - We have a full segment (or more with TSO) - This is the last
20569 	 * buffer in a write()/send() and we are either idle or running
20570 	 * NODELAY - we've timed out (e.g. persist timer) - we have more
20571 	 * then 1/2 the maximum send window's worth of data (receiver may be
20572 	 * limited the window size) - we need to retransmit
20573 	 */
20574 	if (len) {
20575 		if (len >= segsiz) {
20576 			goto send;
20577 		}
20578 		/*
20579 		 * NOTE! on localhost connections an 'ack' from the remote
20580 		 * end may occur synchronously with the output and cause us
20581 		 * to flush a buffer queued with moretocome.  XXX
20582 		 *
20583 		 */
20584 		if (!(tp->t_flags & TF_MORETOCOME) &&	/* normal case */
20585 		    (idle || (tp->t_flags & TF_NODELAY)) &&
20586 		    ((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
20587 		    (tp->t_flags & TF_NOPUSH) == 0) {
20588 			pass = 2;
20589 			goto send;
20590 		}
20591 		if ((tp->snd_una == tp->snd_max) && len) {	/* Nothing outstanding */
20592 			pass = 22;
20593 			goto send;
20594 		}
20595 		if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0) {
20596 			pass = 4;
20597 			goto send;
20598 		}
20599 		if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {	/* retransmit case */
20600 			pass = 5;
20601 			goto send;
20602 		}
20603 		if (sack_rxmit) {
20604 			pass = 6;
20605 			goto send;
20606 		}
20607 		if (((tp->snd_wnd - ctf_outstanding(tp)) < segsiz) &&
20608 		    (ctf_outstanding(tp) < (segsiz * 2))) {
20609 			/*
20610 			 * We have less than two MSS outstanding (delayed ack)
20611 			 * and our rwnd will not let us send a full sized
20612 			 * MSS. Lets go ahead and let this small segment
20613 			 * out because we want to try to have at least two
20614 			 * packets inflight to not be caught by delayed ack.
20615 			 */
20616 			pass = 12;
20617 			goto send;
20618 		}
20619 	}
20620 	/*
20621 	 * Sending of standalone window updates.
20622 	 *
20623 	 * Window updates are important when we close our window due to a
20624 	 * full socket buffer and are opening it again after the application
20625 	 * reads data from it.  Once the window has opened again and the
20626 	 * remote end starts to send again the ACK clock takes over and
20627 	 * provides the most current window information.
20628 	 *
20629 	 * We must avoid the silly window syndrome whereas every read from
20630 	 * the receive buffer, no matter how small, causes a window update
20631 	 * to be sent.  We also should avoid sending a flurry of window
20632 	 * updates when the socket buffer had queued a lot of data and the
20633 	 * application is doing small reads.
20634 	 *
20635 	 * Prevent a flurry of pointless window updates by only sending an
20636 	 * update when we can increase the advertized window by more than
20637 	 * 1/4th of the socket buffer capacity.  When the buffer is getting
20638 	 * full or is very small be more aggressive and send an update
20639 	 * whenever we can increase by two mss sized segments. In all other
20640 	 * situations the ACK's to new incoming data will carry further
20641 	 * window increases.
20642 	 *
20643 	 * Don't send an independent window update if a delayed ACK is
20644 	 * pending (it will get piggy-backed on it) or the remote side
20645 	 * already has done a half-close and won't send more data.  Skip
20646 	 * this if the connection is in T/TCP half-open state.
20647 	 */
20648 	if (recwin > 0 && !(tp->t_flags & TF_NEEDSYN) &&
20649 	    !(tp->t_flags & TF_DELACK) &&
20650 	    !TCPS_HAVERCVDFIN(tp->t_state)) {
20651 		/*
20652 		 * "adv" is the amount we could increase the window, taking
20653 		 * into account that we are limited by TCP_MAXWIN <<
20654 		 * tp->rcv_scale.
20655 		 */
20656 		int32_t adv;
20657 		int oldwin;
20658 
20659 		adv = recwin;
20660 		if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt)) {
20661 			oldwin = (tp->rcv_adv - tp->rcv_nxt);
20662 			if (adv > oldwin)
20663 				adv -= oldwin;
20664 			else {
20665 				/* We can't increase the window */
20666 				adv = 0;
20667 			}
20668 		} else
20669 			oldwin = 0;
20670 
20671 		/*
20672 		 * If the new window size ends up being the same as or less
20673 		 * than the old size when it is scaled, then don't force
20674 		 * a window update.
20675 		 */
20676 		if (oldwin >> tp->rcv_scale >= (adv + oldwin) >> tp->rcv_scale)
20677 			goto dontupdate;
20678 
20679 		if (adv >= (int32_t)(2 * segsiz) &&
20680 		    (adv >= (int32_t)(so->so_rcv.sb_hiwat / 4) ||
20681 		     recwin <= (int32_t)(so->so_rcv.sb_hiwat / 8) ||
20682 		     so->so_rcv.sb_hiwat <= 8 * segsiz)) {
20683 			pass = 7;
20684 			goto send;
20685 		}
20686 		if (2 * adv >= (int32_t) so->so_rcv.sb_hiwat) {
20687 			pass = 23;
20688 			goto send;
20689 		}
20690 	}
20691 dontupdate:
20692 
20693 	/*
20694 	 * Send if we owe the peer an ACK, RST, SYN, or urgent data.  ACKNOW
20695 	 * is also a catch-all for the retransmit timer timeout case.
20696 	 */
20697 	if (tp->t_flags & TF_ACKNOW) {
20698 		pass = 8;
20699 		goto send;
20700 	}
20701 	if (((flags & TH_SYN) && (tp->t_flags & TF_NEEDSYN) == 0)) {
20702 		pass = 9;
20703 		goto send;
20704 	}
20705 	/*
20706 	 * If our state indicates that FIN should be sent and we have not
20707 	 * yet done so, then we need to send.
20708 	 */
20709 	if ((flags & TH_FIN) &&
20710 	    (tp->snd_nxt == tp->snd_una)) {
20711 		pass = 11;
20712 		goto send;
20713 	}
20714 	/*
20715 	 * No reason to send a segment, just return.
20716 	 */
20717 just_return:
20718 	SOCKBUF_UNLOCK(sb);
20719 just_return_nolock:
20720 	{
20721 		int app_limited = CTF_JR_SENT_DATA;
20722 
20723 		if (tot_len_this_send > 0) {
20724 			/* Make sure snd_nxt is up to max */
20725 			rack->r_ctl.fsb.recwin = recwin;
20726 			slot = rack_get_pacing_delay(rack, tp, tot_len_this_send, NULL, segsiz);
20727 			if ((error == 0) &&
20728 			    rack_use_rfo &&
20729 			    ((flags & (TH_SYN|TH_FIN)) == 0) &&
20730 			    (ipoptlen == 0) &&
20731 			    (tp->snd_nxt == tp->snd_max) &&
20732 			    (tp->rcv_numsacks == 0) &&
20733 			    rack->r_fsb_inited &&
20734 			    TCPS_HAVEESTABLISHED(tp->t_state) &&
20735 			    ((IN_RECOVERY(tp->t_flags)) == 0) &&
20736 			    (rack->r_must_retran == 0) &&
20737 			    ((tp->t_flags & TF_NEEDFIN) == 0) &&
20738 			    (len > 0) && (orig_len > 0) &&
20739 			    (orig_len > len) &&
20740 			    ((orig_len - len) >= segsiz) &&
20741 			    ((optlen == 0) ||
20742 			     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
20743 				/* We can send at least one more MSS using our fsb */
20744 				rack_setup_fast_output(tp, rack, sb, len, orig_len,
20745 						       segsiz, pace_max_seg, hw_tls, flags);
20746 			} else
20747 				rack->r_fast_output = 0;
20748 
20749 
20750 			rack_log_fsb(rack, tp, so, flags,
20751 				     ipoptlen, orig_len, len, 0,
20752 				     1, optlen, __LINE__, 1);
20753 			if (SEQ_GT(tp->snd_max, tp->snd_nxt))
20754 				tp->snd_nxt = tp->snd_max;
20755 		} else {
20756 			int end_window = 0;
20757 			uint32_t seq = tp->gput_ack;
20758 
20759 			rsm = tqhash_max(rack->r_ctl.tqh);
20760 			if (rsm) {
20761 				/*
20762 				 * Mark the last sent that we just-returned (hinting
20763 				 * that delayed ack may play a role in any rtt measurement).
20764 				 */
20765 				rsm->r_just_ret = 1;
20766 			}
20767 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_JUSTRET], 1);
20768 			rack->r_ctl.rc_agg_delayed = 0;
20769 			rack->r_early = 0;
20770 			rack->r_late = 0;
20771 			rack->r_ctl.rc_agg_early = 0;
20772 			if ((ctf_outstanding(tp) +
20773 			     min(max(segsiz, (rack->r_ctl.rc_high_rwnd/2)),
20774 				 minseg)) >= tp->snd_wnd) {
20775 				/* We are limited by the rwnd */
20776 				app_limited = CTF_JR_RWND_LIMITED;
20777 				if (IN_FASTRECOVERY(tp->t_flags))
20778 					rack->r_ctl.rc_prr_sndcnt = 0;
20779 			} else if (ctf_outstanding(tp) >= sbavail(sb)) {
20780 				/* We are limited by whats available -- app limited */
20781 				app_limited = CTF_JR_APP_LIMITED;
20782 				if (IN_FASTRECOVERY(tp->t_flags))
20783 					rack->r_ctl.rc_prr_sndcnt = 0;
20784 			} else if ((idle == 0) &&
20785 				   ((tp->t_flags & TF_NODELAY) == 0) &&
20786 				   ((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
20787 				   (len < segsiz)) {
20788 				/*
20789 				 * No delay is not on and the
20790 				 * user is sending less than 1MSS. This
20791 				 * brings out SWS avoidance so we
20792 				 * don't send. Another app-limited case.
20793 				 */
20794 				app_limited = CTF_JR_APP_LIMITED;
20795 			} else if (tp->t_flags & TF_NOPUSH) {
20796 				/*
20797 				 * The user has requested no push of
20798 				 * the last segment and we are
20799 				 * at the last segment. Another app
20800 				 * limited case.
20801 				 */
20802 				app_limited = CTF_JR_APP_LIMITED;
20803 			} else if ((ctf_outstanding(tp) + minseg) > cwnd_to_use) {
20804 				/* Its the cwnd */
20805 				app_limited = CTF_JR_CWND_LIMITED;
20806 			} else if (IN_FASTRECOVERY(tp->t_flags) &&
20807 				   (rack->rack_no_prr == 0) &&
20808 				   (rack->r_ctl.rc_prr_sndcnt < segsiz)) {
20809 				app_limited = CTF_JR_PRR;
20810 			} else {
20811 				/* Now why here are we not sending? */
20812 #ifdef NOW
20813 #ifdef INVARIANTS
20814 				panic("rack:%p hit JR_ASSESSING case cwnd_to_use:%u?", rack, cwnd_to_use);
20815 #endif
20816 #endif
20817 				app_limited = CTF_JR_ASSESSING;
20818 			}
20819 			/*
20820 			 * App limited in some fashion, for our pacing GP
20821 			 * measurements we don't want any gap (even cwnd).
20822 			 * Close  down the measurement window.
20823 			 */
20824 			if (rack_cwnd_block_ends_measure &&
20825 			    ((app_limited == CTF_JR_CWND_LIMITED) ||
20826 			     (app_limited == CTF_JR_PRR))) {
20827 				/*
20828 				 * The reason we are not sending is
20829 				 * the cwnd (or prr). We have been configured
20830 				 * to end the measurement window in
20831 				 * this case.
20832 				 */
20833 				end_window = 1;
20834 			} else if (rack_rwnd_block_ends_measure &&
20835 				   (app_limited == CTF_JR_RWND_LIMITED)) {
20836 				/*
20837 				 * We are rwnd limited and have been
20838 				 * configured to end the measurement
20839 				 * window in this case.
20840 				 */
20841 				end_window = 1;
20842 			} else if (app_limited == CTF_JR_APP_LIMITED) {
20843 				/*
20844 				 * A true application limited period, we have
20845 				 * ran out of data.
20846 				 */
20847 				end_window = 1;
20848 			} else if (app_limited == CTF_JR_ASSESSING) {
20849 				/*
20850 				 * In the assessing case we hit the end of
20851 				 * the if/else and had no known reason
20852 				 * This will panic us under invariants..
20853 				 *
20854 				 * If we get this out in logs we need to
20855 				 * investagate which reason we missed.
20856 				 */
20857 				end_window = 1;
20858 			}
20859 			if (end_window) {
20860 				uint8_t log = 0;
20861 
20862 				/* Adjust the Gput measurement */
20863 				if ((tp->t_flags & TF_GPUTINPROG) &&
20864 				    SEQ_GT(tp->gput_ack, tp->snd_max)) {
20865 					tp->gput_ack = tp->snd_max;
20866 					if ((tp->gput_ack - tp->gput_seq) < (MIN_GP_WIN * segsiz)) {
20867 						/*
20868 						 * There is not enough to measure.
20869 						 */
20870 						tp->t_flags &= ~TF_GPUTINPROG;
20871 						rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
20872 									   rack->r_ctl.rc_gp_srtt /*flex1*/,
20873 									   tp->gput_seq,
20874 									   0, 0, 18, __LINE__, NULL, 0);
20875 					} else
20876 						log = 1;
20877 				}
20878 				/* Mark the last packet has app limited */
20879 				rsm = tqhash_max(rack->r_ctl.tqh);
20880 				if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
20881 					if (rack->r_ctl.rc_app_limited_cnt == 0)
20882 						rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
20883 					else {
20884 						/*
20885 						 * Go out to the end app limited and mark
20886 						 * this new one as next and move the end_appl up
20887 						 * to this guy.
20888 						 */
20889 						if (rack->r_ctl.rc_end_appl)
20890 							rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
20891 						rack->r_ctl.rc_end_appl = rsm;
20892 					}
20893 					rsm->r_flags |= RACK_APP_LIMITED;
20894 					rack->r_ctl.rc_app_limited_cnt++;
20895 				}
20896 				if (log)
20897 					rack_log_pacing_delay_calc(rack,
20898 								   rack->r_ctl.rc_app_limited_cnt, seq,
20899 								   tp->gput_ack, 0, 0, 4, __LINE__, NULL, 0);
20900 			}
20901 		}
20902 		/* Check if we need to go into persists or not */
20903 		if ((tp->snd_max == tp->snd_una) &&
20904 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
20905 		    sbavail(sb) &&
20906 		    (sbavail(sb) > tp->snd_wnd) &&
20907 		    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg))) {
20908 			/* Yes lets make sure to move to persist before timer-start */
20909 			rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime, tp->snd_una);
20910 		}
20911 		rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, sup_rack);
20912 		rack_log_type_just_return(rack, cts, tot_len_this_send, slot, hpts_calling, app_limited, cwnd_to_use);
20913 	}
20914 #ifdef NETFLIX_SHARED_CWND
20915 	if ((sbavail(sb) == 0) &&
20916 	    rack->r_ctl.rc_scw) {
20917 		tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
20918 		rack->rack_scwnd_is_idle = 1;
20919 	}
20920 #endif
20921 #ifdef TCP_ACCOUNTING
20922 	if (tot_len_this_send > 0) {
20923 		crtsc = get_cyclecount();
20924 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
20925 			tp->tcp_cnt_counters[SND_OUT_DATA]++;
20926 		}
20927 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
20928 			tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
20929 		}
20930 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
20931 			tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len_this_send + segsiz - 1) / segsiz);
20932 		}
20933 	} else {
20934 		crtsc = get_cyclecount();
20935 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
20936 			tp->tcp_cnt_counters[SND_LIMITED]++;
20937 		}
20938 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
20939 			tp->tcp_proc_time[SND_LIMITED] += (crtsc - ts_val);
20940 		}
20941 	}
20942 	sched_unpin();
20943 #endif
20944 	return (0);
20945 
20946 send:
20947 	if ((rack->r_ctl.crte != NULL) &&
20948 	    (rsm == NULL) &&
20949 	    ((rack->rc_hw_nobuf == 1) ||
20950 	     (rack_hw_check_queue && (check_done == 0)))) {
20951 		/*
20952 		 * We only want to do this once with the hw_check_queue,
20953 		 * for the enobuf case we would only do it once if
20954 		 * we come around to again, the flag will be clear.
20955 		 */
20956 		check_done = 1;
20957 		slot = rack_check_queue_level(rack, tp, &tv, cts, len, segsiz);
20958 		if (slot) {
20959 			rack->r_ctl.rc_agg_delayed = 0;
20960 			rack->r_ctl.rc_agg_early = 0;
20961 			rack->r_early = 0;
20962 			rack->r_late = 0;
20963 			SOCKBUF_UNLOCK(&so->so_snd);
20964 			goto skip_all_send;
20965 		}
20966 	}
20967 	if (rsm || sack_rxmit)
20968 		counter_u64_add(rack_nfto_resend, 1);
20969 	else
20970 		counter_u64_add(rack_non_fto_send, 1);
20971 	if ((flags & TH_FIN) &&
20972 	    sbavail(sb)) {
20973 		/*
20974 		 * We do not transmit a FIN
20975 		 * with data outstanding. We
20976 		 * need to make it so all data
20977 		 * is acked first.
20978 		 */
20979 		flags &= ~TH_FIN;
20980 	}
20981 	/* Enforce stack imposed max seg size if we have one */
20982 	if (rack->r_ctl.rc_pace_max_segs &&
20983 	    (len > rack->r_ctl.rc_pace_max_segs)) {
20984 		mark = 1;
20985 		len = rack->r_ctl.rc_pace_max_segs;
20986 	}
20987 	SOCKBUF_LOCK_ASSERT(sb);
20988 	if (len > 0) {
20989 		if (len >= segsiz)
20990 			tp->t_flags2 |= TF2_PLPMTU_MAXSEGSNT;
20991 		else
20992 			tp->t_flags2 &= ~TF2_PLPMTU_MAXSEGSNT;
20993 	}
20994 	/*
20995 	 * Before ESTABLISHED, force sending of initial options unless TCP
20996 	 * set not to do any options. NOTE: we assume that the IP/TCP header
20997 	 * plus TCP options always fit in a single mbuf, leaving room for a
20998 	 * maximum link header, i.e. max_linkhdr + sizeof (struct tcpiphdr)
20999 	 * + optlen <= MCLBYTES
21000 	 */
21001 	optlen = 0;
21002 #ifdef INET6
21003 	if (isipv6)
21004 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
21005 	else
21006 #endif
21007 		hdrlen = sizeof(struct tcpiphdr);
21008 
21009 	/*
21010 	 * Compute options for segment. We only have to care about SYN and
21011 	 * established connection segments.  Options for SYN-ACK segments
21012 	 * are handled in TCP syncache.
21013 	 */
21014 	to.to_flags = 0;
21015 	if ((tp->t_flags & TF_NOOPT) == 0) {
21016 		/* Maximum segment size. */
21017 		if (flags & TH_SYN) {
21018 			tp->snd_nxt = tp->iss;
21019 			to.to_mss = tcp_mssopt(&inp->inp_inc);
21020 			if (tp->t_port)
21021 				to.to_mss -= V_tcp_udp_tunneling_overhead;
21022 			to.to_flags |= TOF_MSS;
21023 
21024 			/*
21025 			 * On SYN or SYN|ACK transmits on TFO connections,
21026 			 * only include the TFO option if it is not a
21027 			 * retransmit, as the presence of the TFO option may
21028 			 * have caused the original SYN or SYN|ACK to have
21029 			 * been dropped by a middlebox.
21030 			 */
21031 			if (IS_FASTOPEN(tp->t_flags) &&
21032 			    (tp->t_rxtshift == 0)) {
21033 				if (tp->t_state == TCPS_SYN_RECEIVED) {
21034 					to.to_tfo_len = TCP_FASTOPEN_COOKIE_LEN;
21035 					to.to_tfo_cookie =
21036 						(u_int8_t *)&tp->t_tfo_cookie.server;
21037 					to.to_flags |= TOF_FASTOPEN;
21038 					wanted_cookie = 1;
21039 				} else if (tp->t_state == TCPS_SYN_SENT) {
21040 					to.to_tfo_len =
21041 						tp->t_tfo_client_cookie_len;
21042 					to.to_tfo_cookie =
21043 						tp->t_tfo_cookie.client;
21044 					to.to_flags |= TOF_FASTOPEN;
21045 					wanted_cookie = 1;
21046 					/*
21047 					 * If we wind up having more data to
21048 					 * send with the SYN than can fit in
21049 					 * one segment, don't send any more
21050 					 * until the SYN|ACK comes back from
21051 					 * the other end.
21052 					 */
21053 					sendalot = 0;
21054 				}
21055 			}
21056 		}
21057 		/* Window scaling. */
21058 		if ((flags & TH_SYN) && (tp->t_flags & TF_REQ_SCALE)) {
21059 			to.to_wscale = tp->request_r_scale;
21060 			to.to_flags |= TOF_SCALE;
21061 		}
21062 		/* Timestamps. */
21063 		if ((tp->t_flags & TF_RCVD_TSTMP) ||
21064 		    ((flags & TH_SYN) && (tp->t_flags & TF_REQ_TSTMP))) {
21065 			to.to_tsval = ms_cts + tp->ts_offset;
21066 			to.to_tsecr = tp->ts_recent;
21067 			to.to_flags |= TOF_TS;
21068 		}
21069 		/* Set receive buffer autosizing timestamp. */
21070 		if (tp->rfbuf_ts == 0 &&
21071 		    (so->so_rcv.sb_flags & SB_AUTOSIZE))
21072 			tp->rfbuf_ts = tcp_ts_getticks();
21073 		/* Selective ACK's. */
21074 		if (tp->t_flags & TF_SACK_PERMIT) {
21075 			if (flags & TH_SYN)
21076 				to.to_flags |= TOF_SACKPERM;
21077 			else if (TCPS_HAVEESTABLISHED(tp->t_state) &&
21078 				 tp->rcv_numsacks > 0) {
21079 				to.to_flags |= TOF_SACK;
21080 				to.to_nsacks = tp->rcv_numsacks;
21081 				to.to_sacks = (u_char *)tp->sackblks;
21082 			}
21083 		}
21084 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
21085 		/* TCP-MD5 (RFC2385). */
21086 		if (tp->t_flags & TF_SIGNATURE)
21087 			to.to_flags |= TOF_SIGNATURE;
21088 #endif				/* TCP_SIGNATURE */
21089 
21090 		/* Processing the options. */
21091 		hdrlen += optlen = tcp_addoptions(&to, opt);
21092 		/*
21093 		 * If we wanted a TFO option to be added, but it was unable
21094 		 * to fit, ensure no data is sent.
21095 		 */
21096 		if (IS_FASTOPEN(tp->t_flags) && wanted_cookie &&
21097 		    !(to.to_flags & TOF_FASTOPEN))
21098 			len = 0;
21099 	}
21100 	if (tp->t_port) {
21101 		if (V_tcp_udp_tunneling_port == 0) {
21102 			/* The port was removed?? */
21103 			SOCKBUF_UNLOCK(&so->so_snd);
21104 #ifdef TCP_ACCOUNTING
21105 			crtsc = get_cyclecount();
21106 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
21107 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
21108 			}
21109 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
21110 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
21111 			}
21112 			sched_unpin();
21113 #endif
21114 			return (EHOSTUNREACH);
21115 		}
21116 		hdrlen += sizeof(struct udphdr);
21117 	}
21118 #ifdef INET6
21119 	if (isipv6)
21120 		ipoptlen = ip6_optlen(inp);
21121 	else
21122 #endif
21123 		if (inp->inp_options)
21124 			ipoptlen = inp->inp_options->m_len -
21125 				offsetof(struct ipoption, ipopt_list);
21126 		else
21127 			ipoptlen = 0;
21128 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
21129 	ipoptlen += ipsec_optlen;
21130 #endif
21131 
21132 	/*
21133 	 * Adjust data length if insertion of options will bump the packet
21134 	 * length beyond the t_maxseg length. Clear the FIN bit because we
21135 	 * cut off the tail of the segment.
21136 	 */
21137 	if (len + optlen + ipoptlen > tp->t_maxseg) {
21138 		if (tso) {
21139 			uint32_t if_hw_tsomax;
21140 			uint32_t moff;
21141 			int32_t max_len;
21142 
21143 			/* extract TSO information */
21144 			if_hw_tsomax = tp->t_tsomax;
21145 			if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
21146 			if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
21147 			KASSERT(ipoptlen == 0,
21148 				("%s: TSO can't do IP options", __func__));
21149 
21150 			/*
21151 			 * Check if we should limit by maximum payload
21152 			 * length:
21153 			 */
21154 			if (if_hw_tsomax != 0) {
21155 				/* compute maximum TSO length */
21156 				max_len = (if_hw_tsomax - hdrlen -
21157 					   max_linkhdr);
21158 				if (max_len <= 0) {
21159 					len = 0;
21160 				} else if (len > max_len) {
21161 					sendalot = 1;
21162 					len = max_len;
21163 					mark = 2;
21164 				}
21165 			}
21166 			/*
21167 			 * Prevent the last segment from being fractional
21168 			 * unless the send sockbuf can be emptied:
21169 			 */
21170 			max_len = (tp->t_maxseg - optlen);
21171 			if ((sb_offset + len) < sbavail(sb)) {
21172 				moff = len % (u_int)max_len;
21173 				if (moff != 0) {
21174 					mark = 3;
21175 					len -= moff;
21176 				}
21177 			}
21178 			/*
21179 			 * In case there are too many small fragments don't
21180 			 * use TSO:
21181 			 */
21182 			if (len <= max_len) {
21183 				mark = 4;
21184 				tso = 0;
21185 			}
21186 			/*
21187 			 * Send the FIN in a separate segment after the bulk
21188 			 * sending is done. We don't trust the TSO
21189 			 * implementations to clear the FIN flag on all but
21190 			 * the last segment.
21191 			 */
21192 			if (tp->t_flags & TF_NEEDFIN) {
21193 				sendalot = 4;
21194 			}
21195 		} else {
21196 			mark = 5;
21197 			if (optlen + ipoptlen >= tp->t_maxseg) {
21198 				/*
21199 				 * Since we don't have enough space to put
21200 				 * the IP header chain and the TCP header in
21201 				 * one packet as required by RFC 7112, don't
21202 				 * send it. Also ensure that at least one
21203 				 * byte of the payload can be put into the
21204 				 * TCP segment.
21205 				 */
21206 				SOCKBUF_UNLOCK(&so->so_snd);
21207 				error = EMSGSIZE;
21208 				sack_rxmit = 0;
21209 				goto out;
21210 			}
21211 			len = tp->t_maxseg - optlen - ipoptlen;
21212 			sendalot = 5;
21213 		}
21214 	} else {
21215 		tso = 0;
21216 		mark = 6;
21217 	}
21218 	KASSERT(len + hdrlen + ipoptlen <= IP_MAXPACKET,
21219 		("%s: len > IP_MAXPACKET", __func__));
21220 #ifdef DIAGNOSTIC
21221 #ifdef INET6
21222 	if (max_linkhdr + hdrlen > MCLBYTES)
21223 #else
21224 		if (max_linkhdr + hdrlen > MHLEN)
21225 #endif
21226 			panic("tcphdr too big");
21227 #endif
21228 
21229 	/*
21230 	 * This KASSERT is here to catch edge cases at a well defined place.
21231 	 * Before, those had triggered (random) panic conditions further
21232 	 * down.
21233 	 */
21234 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
21235 	if ((len == 0) &&
21236 	    (flags & TH_FIN) &&
21237 	    (sbused(sb))) {
21238 		/*
21239 		 * We have outstanding data, don't send a fin by itself!.
21240 		 */
21241 		goto just_return;
21242 	}
21243 	/*
21244 	 * Grab a header mbuf, attaching a copy of data to be transmitted,
21245 	 * and initialize the header from the template for sends on this
21246 	 * connection.
21247 	 */
21248 	hw_tls = tp->t_nic_ktls_xmit != 0;
21249 	if (len) {
21250 		uint32_t max_val;
21251 		uint32_t moff;
21252 
21253 		if (rack->r_ctl.rc_pace_max_segs)
21254 			max_val = rack->r_ctl.rc_pace_max_segs;
21255 		else if (rack->rc_user_set_max_segs)
21256 			max_val = rack->rc_user_set_max_segs * segsiz;
21257 		else
21258 			max_val = len;
21259 		/*
21260 		 * We allow a limit on sending with hptsi.
21261 		 */
21262 		if (len > max_val) {
21263 			mark = 7;
21264 			len = max_val;
21265 		}
21266 #ifdef INET6
21267 		if (MHLEN < hdrlen + max_linkhdr)
21268 			m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
21269 		else
21270 #endif
21271 			m = m_gethdr(M_NOWAIT, MT_DATA);
21272 
21273 		if (m == NULL) {
21274 			SOCKBUF_UNLOCK(sb);
21275 			error = ENOBUFS;
21276 			sack_rxmit = 0;
21277 			goto out;
21278 		}
21279 		m->m_data += max_linkhdr;
21280 		m->m_len = hdrlen;
21281 
21282 		/*
21283 		 * Start the m_copy functions from the closest mbuf to the
21284 		 * sb_offset in the socket buffer chain.
21285 		 */
21286 		mb = sbsndptr_noadv(sb, sb_offset, &moff);
21287 		s_mb = mb;
21288 		s_moff = moff;
21289 		if (len <= MHLEN - hdrlen - max_linkhdr && !hw_tls) {
21290 			m_copydata(mb, moff, (int)len,
21291 				   mtod(m, caddr_t)+hdrlen);
21292 			if (SEQ_LT(tp->snd_nxt, tp->snd_max))
21293 				sbsndptr_adv(sb, mb, len);
21294 			m->m_len += len;
21295 		} else {
21296 			struct sockbuf *msb;
21297 
21298 			if (SEQ_LT(tp->snd_nxt, tp->snd_max))
21299 				msb = NULL;
21300 			else
21301 				msb = sb;
21302 			m->m_next = tcp_m_copym(
21303 				mb, moff, &len,
21304 				if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, msb,
21305 				((rsm == NULL) ? hw_tls : 0)
21306 #ifdef NETFLIX_COPY_ARGS
21307 				, &s_mb, &s_moff
21308 #endif
21309 				);
21310 			if (len <= (tp->t_maxseg - optlen)) {
21311 				/*
21312 				 * Must have ran out of mbufs for the copy
21313 				 * shorten it to no longer need tso. Lets
21314 				 * not put on sendalot since we are low on
21315 				 * mbufs.
21316 				 */
21317 				tso = 0;
21318 			}
21319 			if (m->m_next == NULL) {
21320 				SOCKBUF_UNLOCK(sb);
21321 				(void)m_free(m);
21322 				error = ENOBUFS;
21323 				sack_rxmit = 0;
21324 				goto out;
21325 			}
21326 		}
21327 		if (SEQ_LT(tp->snd_nxt, tp->snd_max) || sack_rxmit) {
21328 			if (rsm && (rsm->r_flags & RACK_TLP)) {
21329 				/*
21330 				 * TLP should not count in retran count, but
21331 				 * in its own bin
21332 				 */
21333 				counter_u64_add(rack_tlp_retran, 1);
21334 				counter_u64_add(rack_tlp_retran_bytes, len);
21335 			} else {
21336 				tp->t_sndrexmitpack++;
21337 				KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
21338 				KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
21339 			}
21340 #ifdef STATS
21341 			stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
21342 						 len);
21343 #endif
21344 		} else {
21345 			KMOD_TCPSTAT_INC(tcps_sndpack);
21346 			KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
21347 #ifdef STATS
21348 			stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
21349 						 len);
21350 #endif
21351 		}
21352 		/*
21353 		 * If we're sending everything we've got, set PUSH. (This
21354 		 * will keep happy those implementations which only give
21355 		 * data to the user when a buffer fills or a PUSH comes in.)
21356 		 */
21357 		if (sb_offset + len == sbused(sb) &&
21358 		    sbused(sb) &&
21359 		    !(flags & TH_SYN)) {
21360 			flags |= TH_PUSH;
21361 			add_flag |= RACK_HAD_PUSH;
21362 		}
21363 
21364 		SOCKBUF_UNLOCK(sb);
21365 	} else {
21366 		SOCKBUF_UNLOCK(sb);
21367 		if (tp->t_flags & TF_ACKNOW)
21368 			KMOD_TCPSTAT_INC(tcps_sndacks);
21369 		else if (flags & (TH_SYN | TH_FIN | TH_RST))
21370 			KMOD_TCPSTAT_INC(tcps_sndctrl);
21371 		else
21372 			KMOD_TCPSTAT_INC(tcps_sndwinup);
21373 
21374 		m = m_gethdr(M_NOWAIT, MT_DATA);
21375 		if (m == NULL) {
21376 			error = ENOBUFS;
21377 			sack_rxmit = 0;
21378 			goto out;
21379 		}
21380 #ifdef INET6
21381 		if (isipv6 && (MHLEN < hdrlen + max_linkhdr) &&
21382 		    MHLEN >= hdrlen) {
21383 			M_ALIGN(m, hdrlen);
21384 		} else
21385 #endif
21386 			m->m_data += max_linkhdr;
21387 		m->m_len = hdrlen;
21388 	}
21389 	SOCKBUF_UNLOCK_ASSERT(sb);
21390 	m->m_pkthdr.rcvif = (struct ifnet *)0;
21391 #ifdef MAC
21392 	mac_inpcb_create_mbuf(inp, m);
21393 #endif
21394 	if ((ipoptlen == 0) && (rack->r_ctl.fsb.tcp_ip_hdr) &&  rack->r_fsb_inited) {
21395 #ifdef INET6
21396 		if (isipv6)
21397 			ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
21398 		else
21399 #endif				/* INET6 */
21400 #ifdef INET
21401 			ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
21402 #endif
21403 		th = rack->r_ctl.fsb.th;
21404 		udp = rack->r_ctl.fsb.udp;
21405 		if (udp) {
21406 #ifdef INET6
21407 			if (isipv6)
21408 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
21409 			else
21410 #endif				/* INET6 */
21411 				ulen = hdrlen + len - sizeof(struct ip);
21412 			udp->uh_ulen = htons(ulen);
21413 		}
21414 	} else {
21415 #ifdef INET6
21416 		if (isipv6) {
21417 			ip6 = mtod(m, struct ip6_hdr *);
21418 			if (tp->t_port) {
21419 				udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
21420 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
21421 				udp->uh_dport = tp->t_port;
21422 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
21423 				udp->uh_ulen = htons(ulen);
21424 				th = (struct tcphdr *)(udp + 1);
21425 			} else
21426 				th = (struct tcphdr *)(ip6 + 1);
21427 			tcpip_fillheaders(inp, tp->t_port, ip6, th);
21428 		} else
21429 #endif				/* INET6 */
21430 		{
21431 #ifdef INET
21432 			ip = mtod(m, struct ip *);
21433 			if (tp->t_port) {
21434 				udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
21435 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
21436 				udp->uh_dport = tp->t_port;
21437 				ulen = hdrlen + len - sizeof(struct ip);
21438 				udp->uh_ulen = htons(ulen);
21439 				th = (struct tcphdr *)(udp + 1);
21440 			} else
21441 				th = (struct tcphdr *)(ip + 1);
21442 			tcpip_fillheaders(inp, tp->t_port, ip, th);
21443 #endif
21444 		}
21445 	}
21446 	/*
21447 	 * Fill in fields, remembering maximum advertised window for use in
21448 	 * delaying messages about window sizes. If resending a FIN, be sure
21449 	 * not to use a new sequence number.
21450 	 */
21451 	if (flags & TH_FIN && tp->t_flags & TF_SENTFIN &&
21452 	    tp->snd_nxt == tp->snd_max)
21453 		tp->snd_nxt--;
21454 	/*
21455 	 * If we are starting a connection, send ECN setup SYN packet. If we
21456 	 * are on a retransmit, we may resend those bits a number of times
21457 	 * as per RFC 3168.
21458 	 */
21459 	if (tp->t_state == TCPS_SYN_SENT && V_tcp_do_ecn) {
21460 		flags |= tcp_ecn_output_syn_sent(tp);
21461 	}
21462 	/* Also handle parallel SYN for ECN */
21463 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
21464 	    (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))) {
21465 		int ect = tcp_ecn_output_established(tp, &flags, len, sack_rxmit);
21466 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
21467 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
21468 			tp->t_flags2 &= ~TF2_ECN_SND_ECE;
21469 #ifdef INET6
21470 		if (isipv6) {
21471 			ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
21472 			ip6->ip6_flow |= htonl(ect << 20);
21473 		}
21474 		else
21475 #endif
21476 		{
21477 #ifdef INET
21478 			ip->ip_tos &= ~IPTOS_ECN_MASK;
21479 			ip->ip_tos |= ect;
21480 #endif
21481 		}
21482 	}
21483 	/*
21484 	 * If we are doing retransmissions, then snd_nxt will not reflect
21485 	 * the first unsent octet.  For ACK only packets, we do not want the
21486 	 * sequence number of the retransmitted packet, we want the sequence
21487 	 * number of the next unsent octet.  So, if there is no data (and no
21488 	 * SYN or FIN), use snd_max instead of snd_nxt when filling in
21489 	 * ti_seq.  But if we are in persist state, snd_max might reflect
21490 	 * one byte beyond the right edge of the window, so use snd_nxt in
21491 	 * that case, since we know we aren't doing a retransmission.
21492 	 * (retransmit and persist are mutually exclusive...)
21493 	 */
21494 	if (sack_rxmit == 0) {
21495 		if (len || (flags & (TH_SYN | TH_FIN))) {
21496 			th->th_seq = htonl(tp->snd_nxt);
21497 			rack_seq = tp->snd_nxt;
21498 		} else {
21499 			th->th_seq = htonl(tp->snd_max);
21500 			rack_seq = tp->snd_max;
21501 		}
21502 	} else {
21503 		th->th_seq = htonl(rsm->r_start);
21504 		rack_seq = rsm->r_start;
21505 	}
21506 	th->th_ack = htonl(tp->rcv_nxt);
21507 	tcp_set_flags(th, flags);
21508 	/*
21509 	 * Calculate receive window.  Don't shrink window, but avoid silly
21510 	 * window syndrome.
21511 	 * If a RST segment is sent, advertise a window of zero.
21512 	 */
21513 	if (flags & TH_RST) {
21514 		recwin = 0;
21515 	} else {
21516 		if (recwin < (long)(so->so_rcv.sb_hiwat / 4) &&
21517 		    recwin < (long)segsiz) {
21518 			recwin = 0;
21519 		}
21520 		if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) &&
21521 		    recwin < (long)(tp->rcv_adv - tp->rcv_nxt))
21522 			recwin = (long)(tp->rcv_adv - tp->rcv_nxt);
21523 	}
21524 
21525 	/*
21526 	 * According to RFC1323 the window field in a SYN (i.e., a <SYN> or
21527 	 * <SYN,ACK>) segment itself is never scaled.  The <SYN,ACK> case is
21528 	 * handled in syncache.
21529 	 */
21530 	if (flags & TH_SYN)
21531 		th->th_win = htons((u_short)
21532 				   (min(sbspace(&so->so_rcv), TCP_MAXWIN)));
21533 	else {
21534 		/* Avoid shrinking window with window scaling. */
21535 		recwin = roundup2(recwin, 1 << tp->rcv_scale);
21536 		th->th_win = htons((u_short)(recwin >> tp->rcv_scale));
21537 	}
21538 	/*
21539 	 * Adjust the RXWIN0SENT flag - indicate that we have advertised a 0
21540 	 * window.  This may cause the remote transmitter to stall.  This
21541 	 * flag tells soreceive() to disable delayed acknowledgements when
21542 	 * draining the buffer.  This can occur if the receiver is
21543 	 * attempting to read more data than can be buffered prior to
21544 	 * transmitting on the connection.
21545 	 */
21546 	if (th->th_win == 0) {
21547 		tp->t_sndzerowin++;
21548 		tp->t_flags |= TF_RXWIN0SENT;
21549 	} else
21550 		tp->t_flags &= ~TF_RXWIN0SENT;
21551 	tp->snd_up = tp->snd_una;	/* drag it along, its deprecated */
21552 	/* Now are we using fsb?, if so copy the template data to the mbuf */
21553 	if ((ipoptlen == 0) && (rack->r_ctl.fsb.tcp_ip_hdr) && rack->r_fsb_inited) {
21554 		uint8_t *cpto;
21555 
21556 		cpto = mtod(m, uint8_t *);
21557 		memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
21558 		/*
21559 		 * We have just copied in:
21560 		 * IP/IP6
21561 		 * <optional udphdr>
21562 		 * tcphdr (no options)
21563 		 *
21564 		 * We need to grab the correct pointers into the mbuf
21565 		 * for both the tcp header, and possibly the udp header (if tunneling).
21566 		 * We do this by using the offset in the copy buffer and adding it
21567 		 * to the mbuf base pointer (cpto).
21568 		 */
21569 #ifdef INET6
21570 		if (isipv6)
21571 			ip6 = mtod(m, struct ip6_hdr *);
21572 		else
21573 #endif				/* INET6 */
21574 #ifdef INET
21575 			ip = mtod(m, struct ip *);
21576 #endif
21577 		th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
21578 		/* If we have a udp header lets set it into the mbuf as well */
21579 		if (udp)
21580 			udp = (struct udphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.udp - rack->r_ctl.fsb.tcp_ip_hdr));
21581 	}
21582 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
21583 	if (to.to_flags & TOF_SIGNATURE) {
21584 		/*
21585 		 * Calculate MD5 signature and put it into the place
21586 		 * determined before.
21587 		 * NOTE: since TCP options buffer doesn't point into
21588 		 * mbuf's data, calculate offset and use it.
21589 		 */
21590 		if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
21591 						       (u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
21592 			/*
21593 			 * Do not send segment if the calculation of MD5
21594 			 * digest has failed.
21595 			 */
21596 			goto out;
21597 		}
21598 	}
21599 #endif
21600 	if (optlen) {
21601 		bcopy(opt, th + 1, optlen);
21602 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
21603 	}
21604 	/*
21605 	 * Put TCP length in extended header, and then checksum extended
21606 	 * header and data.
21607 	 */
21608 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
21609 #ifdef INET6
21610 	if (isipv6) {
21611 		/*
21612 		 * ip6_plen is not need to be filled now, and will be filled
21613 		 * in ip6_output.
21614 		 */
21615 		if (tp->t_port) {
21616 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
21617 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
21618 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
21619 			th->th_sum = htons(0);
21620 			UDPSTAT_INC(udps_opackets);
21621 		} else {
21622 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
21623 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
21624 			th->th_sum = in6_cksum_pseudo(ip6,
21625 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
21626 						      0);
21627 		}
21628 	}
21629 #endif
21630 #if defined(INET6) && defined(INET)
21631 	else
21632 #endif
21633 #ifdef INET
21634 	{
21635 		if (tp->t_port) {
21636 			m->m_pkthdr.csum_flags = CSUM_UDP;
21637 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
21638 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
21639 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
21640 			th->th_sum = htons(0);
21641 			UDPSTAT_INC(udps_opackets);
21642 		} else {
21643 			m->m_pkthdr.csum_flags = CSUM_TCP;
21644 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
21645 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
21646 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
21647 									IPPROTO_TCP + len + optlen));
21648 		}
21649 		/* IP version must be set here for ipv4/ipv6 checking later */
21650 		KASSERT(ip->ip_v == IPVERSION,
21651 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
21652 	}
21653 #endif
21654 	/*
21655 	 * Enable TSO and specify the size of the segments. The TCP pseudo
21656 	 * header checksum is always provided. XXX: Fixme: This is currently
21657 	 * not the case for IPv6.
21658 	 */
21659 	if (tso) {
21660 		/*
21661 		 * Here we must use t_maxseg and the optlen since
21662 		 * the optlen may include SACK's (or DSACK).
21663 		 */
21664 		KASSERT(len > tp->t_maxseg - optlen,
21665 			("%s: len <= tso_segsz", __func__));
21666 		m->m_pkthdr.csum_flags |= CSUM_TSO;
21667 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
21668 	}
21669 	KASSERT(len + hdrlen == m_length(m, NULL),
21670 		("%s: mbuf chain different than expected: %d + %u != %u",
21671 		 __func__, len, hdrlen, m_length(m, NULL)));
21672 
21673 #ifdef TCP_HHOOK
21674 	/* Run HHOOK_TCP_ESTABLISHED_OUT helper hooks. */
21675 	hhook_run_tcp_est_out(tp, th, &to, len, tso);
21676 #endif
21677 	if ((rack->r_ctl.crte != NULL) &&
21678 	    (rack->rc_hw_nobuf == 0) &&
21679 	    tcp_bblogging_on(tp)) {
21680 		rack_log_queue_level(tp, rack, len, &tv, cts);
21681 	}
21682 	/* We're getting ready to send; log now. */
21683 	if (tcp_bblogging_on(rack->rc_tp)) {
21684 		union tcp_log_stackspecific log;
21685 
21686 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
21687 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_tp);
21688 		if (rack->rack_no_prr)
21689 			log.u_bbr.flex1 = 0;
21690 		else
21691 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
21692 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
21693 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
21694 		log.u_bbr.flex4 = orig_len;
21695 		/* Save off the early/late values */
21696 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
21697 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
21698 		log.u_bbr.bw_inuse = rack_get_bw(rack);
21699 		log.u_bbr.cur_del_rate = rack->r_ctl.gp_bw;
21700 		log.u_bbr.flex8 = 0;
21701 		if (rsm) {
21702 			if (rsm->r_flags & RACK_RWND_COLLAPSED) {
21703 				rack_log_collapse(rack, rsm->r_start, rsm->r_end, 0, __LINE__, 5, rsm->r_flags, rsm);
21704 				counter_u64_add(rack_collapsed_win_rxt, 1);
21705 				counter_u64_add(rack_collapsed_win_rxt_bytes, (rsm->r_end - rsm->r_start));
21706 			}
21707 			if (doing_tlp)
21708 				log.u_bbr.flex8 = 2;
21709 			else
21710 				log.u_bbr.flex8 = 1;
21711 		} else {
21712 			if (doing_tlp)
21713 				log.u_bbr.flex8 = 3;
21714 		}
21715 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
21716 		log.u_bbr.flex7 = mark;
21717 		log.u_bbr.flex7 <<= 8;
21718 		log.u_bbr.flex7 |= pass;
21719 		log.u_bbr.pkts_out = tp->t_maxseg;
21720 		log.u_bbr.timeStamp = cts;
21721 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
21722 		if (rsm && (rsm->r_rtr_cnt > 0)) {
21723 			/*
21724 			 * When we have a retransmit we want to log the
21725 			 * burst at send and flight at send from before.
21726 			 */
21727 			log.u_bbr.flex5 = rsm->r_fas;
21728 			log.u_bbr.bbr_substate = rsm->r_bas;
21729 		} else {
21730 			/*
21731 			 * New transmits we log in flex5 the inflight again as
21732 			 * well as the number of segments in our send in the
21733 			 * substate field.
21734 			 */
21735 			log.u_bbr.flex5 = log.u_bbr.inflight;
21736 			log.u_bbr.bbr_substate = (uint8_t)((len + segsiz - 1)/segsiz);
21737 		}
21738 		log.u_bbr.lt_epoch = cwnd_to_use;
21739 		log.u_bbr.delivered = sendalot;
21740 		log.u_bbr.rttProp = (uint64_t)rsm;
21741 		log.u_bbr.pkt_epoch = __LINE__;
21742 		if (rsm) {
21743 			log.u_bbr.delRate = rsm->r_flags;
21744 			log.u_bbr.delRate <<= 31;
21745 			log.u_bbr.delRate |= rack->r_must_retran;
21746 			log.u_bbr.delRate <<= 1;
21747 			log.u_bbr.delRate |= (sack_rxmit & 0x00000001);
21748 		} else {
21749 			log.u_bbr.delRate = rack->r_must_retran;
21750 			log.u_bbr.delRate <<= 1;
21751 			log.u_bbr.delRate |= (sack_rxmit & 0x00000001);
21752 		}
21753 		lgb = tcp_log_event(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_OUT, ERRNO_UNK,
21754 				    len, &log, false, NULL, __func__, __LINE__, &tv);
21755 	} else
21756 		lgb = NULL;
21757 
21758 	/*
21759 	 * Fill in IP length and desired time to live and send to IP level.
21760 	 * There should be a better way to handle ttl and tos; we could keep
21761 	 * them in the template, but need a way to checksum without them.
21762 	 */
21763 	/*
21764 	 * m->m_pkthdr.len should have been set before cksum calcuration,
21765 	 * because in6_cksum() need it.
21766 	 */
21767 #ifdef INET6
21768 	if (isipv6) {
21769 		/*
21770 		 * we separately set hoplimit for every segment, since the
21771 		 * user might want to change the value via setsockopt. Also,
21772 		 * desired default hop limit might be changed via Neighbor
21773 		 * Discovery.
21774 		 */
21775 		rack->r_ctl.fsb.hoplimit = ip6->ip6_hlim = in6_selecthlim(inp, NULL);
21776 
21777 		/*
21778 		 * Set the packet size here for the benefit of DTrace
21779 		 * probes. ip6_output() will set it properly; it's supposed
21780 		 * to include the option header lengths as well.
21781 		 */
21782 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
21783 
21784 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
21785 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
21786 		else
21787 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
21788 
21789 		if (tp->t_state == TCPS_SYN_SENT)
21790 			TCP_PROBE5(connect__request, NULL, tp, ip6, tp, th);
21791 
21792 		TCP_PROBE5(send, NULL, tp, ip6, tp, th);
21793 		/* TODO: IPv6 IP6TOS_ECT bit on */
21794 		error = ip6_output(m,
21795 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
21796 				   inp->in6p_outputopts,
21797 #else
21798 				   NULL,
21799 #endif
21800 				   &inp->inp_route6,
21801 				   ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0),
21802 				   NULL, NULL, inp);
21803 
21804 		if (error == EMSGSIZE && inp->inp_route6.ro_nh != NULL)
21805 			mtu = inp->inp_route6.ro_nh->nh_mtu;
21806 	}
21807 #endif				/* INET6 */
21808 #if defined(INET) && defined(INET6)
21809 	else
21810 #endif
21811 #ifdef INET
21812 	{
21813 		ip->ip_len = htons(m->m_pkthdr.len);
21814 #ifdef INET6
21815 		if (inp->inp_vflag & INP_IPV6PROTO)
21816 			ip->ip_ttl = in6_selecthlim(inp, NULL);
21817 #endif				/* INET6 */
21818 		rack->r_ctl.fsb.hoplimit = ip->ip_ttl;
21819 		/*
21820 		 * If we do path MTU discovery, then we set DF on every
21821 		 * packet. This might not be the best thing to do according
21822 		 * to RFC3390 Section 2. However the tcp hostcache migitates
21823 		 * the problem so it affects only the first tcp connection
21824 		 * with a host.
21825 		 *
21826 		 * NB: Don't set DF on small MTU/MSS to have a safe
21827 		 * fallback.
21828 		 */
21829 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
21830 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
21831 			if (tp->t_port == 0 || len < V_tcp_minmss) {
21832 				ip->ip_off |= htons(IP_DF);
21833 			}
21834 		} else {
21835 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
21836 		}
21837 
21838 		if (tp->t_state == TCPS_SYN_SENT)
21839 			TCP_PROBE5(connect__request, NULL, tp, ip, tp, th);
21840 
21841 		TCP_PROBE5(send, NULL, tp, ip, tp, th);
21842 
21843 		error = ip_output(m,
21844 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
21845 				  inp->inp_options,
21846 #else
21847 				  NULL,
21848 #endif
21849 				  &inp->inp_route,
21850 				  ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0), 0,
21851 				  inp);
21852 		if (error == EMSGSIZE && inp->inp_route.ro_nh != NULL)
21853 			mtu = inp->inp_route.ro_nh->nh_mtu;
21854 	}
21855 #endif				/* INET */
21856 
21857 out:
21858 	if (lgb) {
21859 		lgb->tlb_errno = error;
21860 		lgb = NULL;
21861 	}
21862 	/*
21863 	 * In transmit state, time the transmission and arrange for the
21864 	 * retransmit.  In persist state, just set snd_max.
21865 	 */
21866 	rack_log_output(tp, &to, len, rack_seq, (uint8_t) flags, error,
21867 			rack_to_usec_ts(&tv),
21868 			rsm, add_flag, s_mb, s_moff, hw_tls, segsiz);
21869 	if (error == 0) {
21870 		if (rsm == NULL) {
21871 			if (rack->lt_bw_up == 0) {
21872 				rack->r_ctl.lt_timemark = tcp_tv_to_lusectick(&tv);
21873 				rack->r_ctl.lt_seq = tp->snd_una;
21874 				rack->lt_bw_up = 1;
21875 			} else if (((rack_seq + len) - rack->r_ctl.lt_seq) > 0x7fffffff) {
21876 				/*
21877 				 * Need to record what we have since we are
21878 				 * approaching seq wrap.
21879 				 */
21880 				uint64_t tmark;
21881 
21882 				rack->r_ctl.lt_bw_bytes += (tp->snd_una - rack->r_ctl.lt_seq);
21883 				rack->r_ctl.lt_seq = tp->snd_una;
21884 				tmark = tcp_tv_to_lusectick(&tv);
21885 				rack->r_ctl.lt_bw_time += (tmark - rack->r_ctl.lt_timemark);
21886 				rack->r_ctl.lt_timemark = tmark;
21887 			}
21888 		}
21889 		rack->forced_ack = 0;	/* If we send something zap the FA flag */
21890 		counter_u64_add(rack_total_bytes, len);
21891 		tcp_account_for_send(tp, len, (rsm != NULL), doing_tlp, hw_tls);
21892 		if (rsm && doing_tlp) {
21893 			rack->rc_last_sent_tlp_past_cumack = 0;
21894 			rack->rc_last_sent_tlp_seq_valid = 1;
21895 			rack->r_ctl.last_sent_tlp_seq = rsm->r_start;
21896 			rack->r_ctl.last_sent_tlp_len = rsm->r_end - rsm->r_start;
21897 		}
21898 		if (rack->rc_hw_nobuf) {
21899 			rack->rc_hw_nobuf = 0;
21900 			rack->r_ctl.rc_agg_delayed = 0;
21901 			rack->r_early = 0;
21902 			rack->r_late = 0;
21903 			rack->r_ctl.rc_agg_early = 0;
21904 		}
21905 		if (rsm && (doing_tlp == 0)) {
21906 			/* Set we retransmitted */
21907 			rack->rc_gp_saw_rec = 1;
21908 		} else {
21909 			if (cwnd_to_use > tp->snd_ssthresh) {
21910 				/* Set we sent in CA */
21911 				rack->rc_gp_saw_ca = 1;
21912 			} else {
21913 				/* Set we sent in SS */
21914 				rack->rc_gp_saw_ss = 1;
21915 			}
21916 		}
21917 		if (TCPS_HAVEESTABLISHED(tp->t_state) &&
21918 		    (tp->t_flags & TF_SACK_PERMIT) &&
21919 		    tp->rcv_numsacks > 0)
21920 			tcp_clean_dsack_blocks(tp);
21921 		tot_len_this_send += len;
21922 		if (len == 0) {
21923 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_SNDACK], 1);
21924 		} else {
21925 			int idx;
21926 
21927 			idx = (len / segsiz) + 3;
21928 			if (idx >= TCP_MSS_ACCT_ATIMER)
21929 				counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
21930 			else
21931 				counter_u64_add(rack_out_size[idx], 1);
21932 		}
21933 	}
21934 	if ((rack->rack_no_prr == 0) &&
21935 	    sub_from_prr &&
21936 	    (error == 0)) {
21937 		if (rack->r_ctl.rc_prr_sndcnt >= len)
21938 			rack->r_ctl.rc_prr_sndcnt -= len;
21939 		else
21940 			rack->r_ctl.rc_prr_sndcnt = 0;
21941 	}
21942 	sub_from_prr = 0;
21943 	if (doing_tlp) {
21944 		/* Make sure the TLP is added */
21945 		add_flag |= RACK_TLP;
21946 	} else if (rsm) {
21947 		/* If its a resend without TLP then it must not have the flag */
21948 		rsm->r_flags &= ~RACK_TLP;
21949 	}
21950 
21951 
21952 	if ((error == 0) &&
21953 	    (len > 0) &&
21954 	    (tp->snd_una == tp->snd_max))
21955 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
21956 	{
21957 		tcp_seq startseq = tp->snd_nxt;
21958 
21959 		/* Track our lost count */
21960 		if (rsm && (doing_tlp == 0))
21961 			rack->r_ctl.rc_loss_count += rsm->r_end - rsm->r_start;
21962 		/*
21963 		 * Advance snd_nxt over sequence space of this segment.
21964 		 */
21965 		if (error)
21966 			/* We don't log or do anything with errors */
21967 			goto nomore;
21968 		if (doing_tlp == 0) {
21969 			if (rsm == NULL) {
21970 				/*
21971 				 * Not a retransmission of some
21972 				 * sort, new data is going out so
21973 				 * clear our TLP count and flag.
21974 				 */
21975 				rack->rc_tlp_in_progress = 0;
21976 				rack->r_ctl.rc_tlp_cnt_out = 0;
21977 			}
21978 		} else {
21979 			/*
21980 			 * We have just sent a TLP, mark that it is true
21981 			 * and make sure our in progress is set so we
21982 			 * continue to check the count.
21983 			 */
21984 			rack->rc_tlp_in_progress = 1;
21985 			rack->r_ctl.rc_tlp_cnt_out++;
21986 		}
21987 		if (flags & (TH_SYN | TH_FIN)) {
21988 			if (flags & TH_SYN)
21989 				tp->snd_nxt++;
21990 			if (flags & TH_FIN) {
21991 				tp->snd_nxt++;
21992 				tp->t_flags |= TF_SENTFIN;
21993 			}
21994 		}
21995 		/* In the ENOBUFS case we do *not* update snd_max */
21996 		if (sack_rxmit)
21997 			goto nomore;
21998 
21999 		tp->snd_nxt += len;
22000 		if (SEQ_GT(tp->snd_nxt, tp->snd_max)) {
22001 			if (tp->snd_una == tp->snd_max) {
22002 				/*
22003 				 * Update the time we just added data since
22004 				 * none was outstanding.
22005 				 */
22006 				rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
22007 				tp->t_acktime = ticks;
22008 			}
22009 			tp->snd_max = tp->snd_nxt;
22010 			if (rack->rc_new_rnd_needed) {
22011 				/*
22012 				 * Update the rnd to start ticking not
22013 				 * that from a time perspective all of
22014 				 * the preceding idle time is "in the round"
22015 				 */
22016 				rack->rc_new_rnd_needed = 0;
22017 				rack->r_ctl.roundends = tp->snd_max;
22018 			}
22019 			/*
22020 			 * Time this transmission if not a retransmission and
22021 			 * not currently timing anything.
22022 			 * This is only relevant in case of switching back to
22023 			 * the base stack.
22024 			 */
22025 			if (tp->t_rtttime == 0) {
22026 				tp->t_rtttime = ticks;
22027 				tp->t_rtseq = startseq;
22028 				KMOD_TCPSTAT_INC(tcps_segstimed);
22029 			}
22030 			if (len &&
22031 			    ((tp->t_flags & TF_GPUTINPROG) == 0))
22032 				rack_start_gp_measurement(tp, rack, startseq, sb_offset);
22033 		}
22034 		/*
22035 		 * If we are doing FO we need to update the mbuf position and subtract
22036 		 * this happens when the peer sends us duplicate information and
22037 		 * we thus want to send a DSACK.
22038 		 *
22039 		 * XXXRRS: This brings to mind a ?, when we send a DSACK block is TSO
22040 		 * turned off? If not then we are going to echo multiple DSACK blocks
22041 		 * out (with the TSO), which we should not be doing.
22042 		 */
22043 		if (rack->r_fast_output && len) {
22044 			if (rack->r_ctl.fsb.left_to_send > len)
22045 				rack->r_ctl.fsb.left_to_send -= len;
22046 			else
22047 				rack->r_ctl.fsb.left_to_send = 0;
22048 			if (rack->r_ctl.fsb.left_to_send < segsiz)
22049 				rack->r_fast_output = 0;
22050 			if (rack->r_fast_output) {
22051 				rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
22052 				rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
22053 				rack->r_ctl.fsb.o_t_len = M_TRAILINGROOM(rack->r_ctl.fsb.m);
22054 			}
22055 		}
22056 	}
22057 nomore:
22058 	if (error) {
22059 		rack->r_ctl.rc_agg_delayed = 0;
22060 		rack->r_early = 0;
22061 		rack->r_late = 0;
22062 		rack->r_ctl.rc_agg_early = 0;
22063 		SOCKBUF_UNLOCK_ASSERT(sb);	/* Check gotos. */
22064 		/*
22065 		 * Failures do not advance the seq counter above. For the
22066 		 * case of ENOBUFS we will fall out and retry in 1ms with
22067 		 * the hpts. Everything else will just have to retransmit
22068 		 * with the timer.
22069 		 *
22070 		 * In any case, we do not want to loop around for another
22071 		 * send without a good reason.
22072 		 */
22073 		sendalot = 0;
22074 		switch (error) {
22075 		case EPERM:
22076 			tp->t_softerror = error;
22077 #ifdef TCP_ACCOUNTING
22078 			crtsc = get_cyclecount();
22079 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22080 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
22081 			}
22082 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22083 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
22084 			}
22085 			sched_unpin();
22086 #endif
22087 			return (error);
22088 		case ENOBUFS:
22089 			/*
22090 			 * Pace us right away to retry in a some
22091 			 * time
22092 			 */
22093 			if (rack->r_ctl.crte != NULL) {
22094 				tcp_trace_point(rack->rc_tp, TCP_TP_HWENOBUF);
22095 				if (tcp_bblogging_on(rack->rc_tp))
22096 					rack_log_queue_level(tp, rack, len, &tv, cts);
22097 			} else
22098 				tcp_trace_point(rack->rc_tp, TCP_TP_ENOBUF);
22099 			slot = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
22100 			if (rack->rc_enobuf < 0x7f)
22101 				rack->rc_enobuf++;
22102 			if (slot < (10 * HPTS_USEC_IN_MSEC))
22103 				slot = 10 * HPTS_USEC_IN_MSEC;
22104 			if (rack->r_ctl.crte != NULL) {
22105 				counter_u64_add(rack_saw_enobuf_hw, 1);
22106 				tcp_rl_log_enobuf(rack->r_ctl.crte);
22107 			}
22108 			counter_u64_add(rack_saw_enobuf, 1);
22109 			goto enobufs;
22110 		case EMSGSIZE:
22111 			/*
22112 			 * For some reason the interface we used initially
22113 			 * to send segments changed to another or lowered
22114 			 * its MTU. If TSO was active we either got an
22115 			 * interface without TSO capabilits or TSO was
22116 			 * turned off. If we obtained mtu from ip_output()
22117 			 * then update it and try again.
22118 			 */
22119 			if (tso)
22120 				tp->t_flags &= ~TF_TSO;
22121 			if (mtu != 0) {
22122 				int saved_mtu;
22123 
22124 				saved_mtu = tp->t_maxseg;
22125 				tcp_mss_update(tp, -1, mtu, NULL, NULL);
22126 				if (saved_mtu > tp->t_maxseg) {
22127 					goto again;
22128 				}
22129 			}
22130 			slot = 10 * HPTS_USEC_IN_MSEC;
22131 			rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
22132 #ifdef TCP_ACCOUNTING
22133 			crtsc = get_cyclecount();
22134 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22135 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
22136 			}
22137 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22138 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
22139 			}
22140 			sched_unpin();
22141 #endif
22142 			return (error);
22143 		case ENETUNREACH:
22144 			counter_u64_add(rack_saw_enetunreach, 1);
22145 		case EHOSTDOWN:
22146 		case EHOSTUNREACH:
22147 		case ENETDOWN:
22148 			if (TCPS_HAVERCVDSYN(tp->t_state)) {
22149 				tp->t_softerror = error;
22150 			}
22151 			/* FALLTHROUGH */
22152 		default:
22153 			slot = 10 * HPTS_USEC_IN_MSEC;
22154 			rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
22155 #ifdef TCP_ACCOUNTING
22156 			crtsc = get_cyclecount();
22157 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22158 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
22159 			}
22160 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22161 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
22162 			}
22163 			sched_unpin();
22164 #endif
22165 			return (error);
22166 		}
22167 	} else {
22168 		rack->rc_enobuf = 0;
22169 		if (IN_FASTRECOVERY(tp->t_flags) && rsm)
22170 			rack->r_ctl.retran_during_recovery += len;
22171 	}
22172 	KMOD_TCPSTAT_INC(tcps_sndtotal);
22173 
22174 	/*
22175 	 * Data sent (as far as we can tell). If this advertises a larger
22176 	 * window than any other segment, then remember the size of the
22177 	 * advertised window. Any pending ACK has now been sent.
22178 	 */
22179 	if (recwin > 0 && SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv))
22180 		tp->rcv_adv = tp->rcv_nxt + recwin;
22181 
22182 	tp->last_ack_sent = tp->rcv_nxt;
22183 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
22184 enobufs:
22185 	if (sendalot) {
22186 		/* Do we need to turn off sendalot? */
22187 		if (rack->r_ctl.rc_pace_max_segs &&
22188 		    (tot_len_this_send >= rack->r_ctl.rc_pace_max_segs)) {
22189 			/* We hit our max. */
22190 			sendalot = 0;
22191 		} else if ((rack->rc_user_set_max_segs) &&
22192 			   (tot_len_this_send >= (rack->rc_user_set_max_segs * segsiz))) {
22193 			/* We hit the user defined max */
22194 			sendalot = 0;
22195 		}
22196 	}
22197 	if ((error == 0) && (flags & TH_FIN))
22198 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_FIN);
22199 	if (flags & TH_RST) {
22200 		/*
22201 		 * We don't send again after sending a RST.
22202 		 */
22203 		slot = 0;
22204 		sendalot = 0;
22205 		if (error == 0)
22206 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
22207 	} else if ((slot == 0) && (sendalot == 0) && tot_len_this_send) {
22208 		/*
22209 		 * Get our pacing rate, if an error
22210 		 * occurred in sending (ENOBUF) we would
22211 		 * hit the else if with slot preset. Other
22212 		 * errors return.
22213 		 */
22214 		slot = rack_get_pacing_delay(rack, tp, tot_len_this_send, rsm, segsiz);
22215 	}
22216 	if (rsm &&
22217 	    (rsm->r_flags & RACK_HAS_SYN) == 0 &&
22218 	    rack->use_rack_rr) {
22219 		/* Its a retransmit and we use the rack cheat? */
22220 		if ((slot == 0) ||
22221 		    (rack->rc_always_pace == 0) ||
22222 		    (rack->r_rr_config == 1)) {
22223 			/*
22224 			 * We have no pacing set or we
22225 			 * are using old-style rack or
22226 			 * we are overridden to use the old 1ms pacing.
22227 			 */
22228 			slot = rack->r_ctl.rc_min_to;
22229 		}
22230 	}
22231 	/* We have sent clear the flag */
22232 	rack->r_ent_rec_ns = 0;
22233 	if (rack->r_must_retran) {
22234 		if (rsm) {
22235 			rack->r_ctl.rc_out_at_rto -= (rsm->r_end - rsm->r_start);
22236 			if (SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) {
22237 				/*
22238 				 * We have retransmitted all.
22239 				 */
22240 				rack->r_must_retran = 0;
22241 				rack->r_ctl.rc_out_at_rto = 0;
22242 			}
22243 		} else if (SEQ_GEQ(tp->snd_max, rack->r_ctl.rc_snd_max_at_rto)) {
22244 			/*
22245 			 * Sending new data will also kill
22246 			 * the loop.
22247 			 */
22248 			rack->r_must_retran = 0;
22249 			rack->r_ctl.rc_out_at_rto = 0;
22250 		}
22251 	}
22252 	rack->r_ctl.fsb.recwin = recwin;
22253 	if ((tp->t_flags & (TF_WASCRECOVERY|TF_WASFRECOVERY)) &&
22254 	    SEQ_GT(tp->snd_max, rack->r_ctl.rc_snd_max_at_rto)) {
22255 		/*
22256 		 * We hit an RTO and now have past snd_max at the RTO
22257 		 * clear all the WAS flags.
22258 		 */
22259 		tp->t_flags &= ~(TF_WASCRECOVERY|TF_WASFRECOVERY);
22260 	}
22261 	if (slot) {
22262 		/* set the rack tcb into the slot N */
22263 		if ((error == 0) &&
22264 		    rack_use_rfo &&
22265 		    ((flags & (TH_SYN|TH_FIN)) == 0) &&
22266 		    (rsm == NULL) &&
22267 		    (tp->snd_nxt == tp->snd_max) &&
22268 		    (ipoptlen == 0) &&
22269 		    (tp->rcv_numsacks == 0) &&
22270 		    rack->r_fsb_inited &&
22271 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
22272 		    ((IN_RECOVERY(tp->t_flags)) == 0) &&
22273 		    (rack->r_must_retran == 0) &&
22274 		    ((tp->t_flags & TF_NEEDFIN) == 0) &&
22275 		    (len > 0) && (orig_len > 0) &&
22276 		    (orig_len > len) &&
22277 		    ((orig_len - len) >= segsiz) &&
22278 		    ((optlen == 0) ||
22279 		     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
22280 			/* We can send at least one more MSS using our fsb */
22281 			rack_setup_fast_output(tp, rack, sb, len, orig_len,
22282 					       segsiz, pace_max_seg, hw_tls, flags);
22283 		} else
22284 			rack->r_fast_output = 0;
22285 		rack_log_fsb(rack, tp, so, flags,
22286 			     ipoptlen, orig_len, len, error,
22287 			     (rsm == NULL), optlen, __LINE__, 2);
22288 	} else if (sendalot) {
22289 		int ret;
22290 
22291 		sack_rxmit = 0;
22292 		if ((error == 0) &&
22293 		    rack_use_rfo &&
22294 		    ((flags & (TH_SYN|TH_FIN)) == 0) &&
22295 		    (rsm == NULL) &&
22296 		    (ipoptlen == 0) &&
22297 		    (tp->rcv_numsacks == 0) &&
22298 		    (tp->snd_nxt == tp->snd_max) &&
22299 		    (rack->r_must_retran == 0) &&
22300 		    rack->r_fsb_inited &&
22301 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
22302 		    ((IN_RECOVERY(tp->t_flags)) == 0) &&
22303 		    ((tp->t_flags & TF_NEEDFIN) == 0) &&
22304 		    (len > 0) && (orig_len > 0) &&
22305 		    (orig_len > len) &&
22306 		    ((orig_len - len) >= segsiz) &&
22307 		    ((optlen == 0) ||
22308 		     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
22309 			/* we can use fast_output for more */
22310 			rack_setup_fast_output(tp, rack, sb, len, orig_len,
22311 					       segsiz, pace_max_seg, hw_tls, flags);
22312 			if (rack->r_fast_output) {
22313 				error = 0;
22314 				ret = rack_fast_output(tp, rack, ts_val, cts, ms_cts, &tv, tot_len_this_send, &error);
22315 				if (ret >= 0)
22316 					return (ret);
22317 			        else if (error)
22318 					goto nomore;
22319 
22320 			}
22321 		}
22322 		goto again;
22323 	}
22324 	/* Assure when we leave that snd_nxt will point to top */
22325 skip_all_send:
22326 	if (SEQ_GT(tp->snd_max, tp->snd_nxt))
22327 		tp->snd_nxt = tp->snd_max;
22328 	rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, 0);
22329 #ifdef TCP_ACCOUNTING
22330 	crtsc = get_cyclecount() - ts_val;
22331 	if (tot_len_this_send) {
22332 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22333 			tp->tcp_cnt_counters[SND_OUT_DATA]++;
22334 		}
22335 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22336 			tp->tcp_proc_time[SND_OUT_DATA] += crtsc;
22337 		}
22338 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22339 			tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len_this_send + segsiz - 1) /segsiz);
22340 		}
22341 	} else {
22342 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22343 			tp->tcp_cnt_counters[SND_OUT_ACK]++;
22344 		}
22345 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
22346 			tp->tcp_proc_time[SND_OUT_ACK] += crtsc;
22347 		}
22348 	}
22349 	sched_unpin();
22350 #endif
22351 	if (error == ENOBUFS)
22352 		error = 0;
22353 	return (error);
22354 }
22355 
22356 static void
22357 rack_update_seg(struct tcp_rack *rack)
22358 {
22359 	uint32_t orig_val;
22360 
22361 	orig_val = rack->r_ctl.rc_pace_max_segs;
22362 	rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
22363 	if (orig_val != rack->r_ctl.rc_pace_max_segs)
22364 		rack_log_pacing_delay_calc(rack, 0, 0, orig_val, 0, 0, 15, __LINE__, NULL, 0);
22365 }
22366 
22367 static void
22368 rack_mtu_change(struct tcpcb *tp)
22369 {
22370 	/*
22371 	 * The MSS may have changed
22372 	 */
22373 	struct tcp_rack *rack;
22374 	struct rack_sendmap *rsm;
22375 
22376 	rack = (struct tcp_rack *)tp->t_fb_ptr;
22377 	if (rack->r_ctl.rc_pace_min_segs != ctf_fixed_maxseg(tp)) {
22378 		/*
22379 		 * The MTU has changed we need to resend everything
22380 		 * since all we have sent is lost. We first fix
22381 		 * up the mtu though.
22382 		 */
22383 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
22384 		/* We treat this like a full retransmit timeout without the cwnd adjustment */
22385 		rack_remxt_tmr(tp);
22386 		rack->r_fast_output = 0;
22387 		rack->r_ctl.rc_out_at_rto = ctf_flight_size(tp,
22388 						rack->r_ctl.rc_sacked);
22389 		rack->r_ctl.rc_snd_max_at_rto = tp->snd_max;
22390 		rack->r_must_retran = 1;
22391 		/* Mark all inflight to needing to be rxt'd */
22392 		TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
22393 			rsm->r_flags |= (RACK_MUST_RXT|RACK_PMTU_CHG);
22394 		}
22395 	}
22396 	sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
22397 	/* We don't use snd_nxt to retransmit */
22398 	tp->snd_nxt = tp->snd_max;
22399 }
22400 
22401 static int
22402 rack_set_dgp(struct tcp_rack *rack)
22403 {
22404 	/* pace_always=1 */
22405 	if (rack->rc_always_pace == 0) {
22406 		if (tcp_can_enable_pacing() == 0)
22407 			return (EBUSY);
22408 	}
22409 	rack->dgp_on = 1;
22410 	rack->rc_always_pace = 1;
22411 	rack->use_fixed_rate = 0;
22412 	if (rack->gp_ready)
22413 		rack_set_cc_pacing(rack);
22414 	rack->rc_tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
22415 	rack->rack_attempt_hdwr_pace = 0;
22416 	/* rxt settings */
22417 	rack->full_size_rxt = 1;
22418 	rack->shape_rxt_to_pacing_min  = 0;
22419 	/* cmpack=1 */
22420 	rack->r_use_cmp_ack = 1;
22421 	if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state) &&
22422 	    rack->r_use_cmp_ack)
22423 		rack->rc_tp->t_flags2 |= TF2_MBUF_ACKCMP;
22424 	/* scwnd=1 */
22425 	rack->rack_enable_scwnd = 1;
22426 	/* dynamic=100 */
22427 	rack->rc_gp_dyn_mul = 1;
22428 	/* gp_inc_ca */
22429 	rack->r_ctl.rack_per_of_gp_ca = 100;
22430 	/* rrr_conf=3 */
22431 	rack->r_rr_config = 3;
22432 	/* npush=2 */
22433 	rack->r_ctl.rc_no_push_at_mrtt = 2;
22434 	/* fillcw=1 */
22435 	if (rack->r_cwnd_was_clamped == 0) {
22436 		rack->rc_pace_to_cwnd = 1;
22437 	} else {
22438 		rack->rc_pace_to_cwnd = 0;
22439 		/* Reset all multipliers to 100.0 so just the measured bw */
22440 		rack->r_ctl.rack_per_of_gp_ss = 100;
22441 		rack->r_ctl.rack_per_of_gp_ca = 100;
22442 	}
22443 	rack->rc_pace_fill_if_rttin_range = 0;
22444 	rack->rtt_limit_mul = 0;
22445 	/* noprr=1 */
22446 	rack->rack_no_prr = 1;
22447 	/* lscwnd=1 */
22448 	rack->r_limit_scw = 1;
22449 	/* gp_inc_rec */
22450 	rack->r_ctl.rack_per_of_gp_rec = 90;
22451 	rack_client_buffer_level_set(rack);
22452 	return (0);
22453 }
22454 
22455 
22456 
22457 static int
22458 rack_set_profile(struct tcp_rack *rack, int prof)
22459 {
22460 	int err = EINVAL;
22461 	if (prof == 1) {
22462 		/*
22463 		 * Profile 1 is "standard" DGP. It ignores
22464 		 * client buffer level.
22465 		 */
22466 		rack->r_ctl.rc_dgp_bl_agg = DGP_LEVEL0;
22467 		err = rack_set_dgp(rack);
22468 		if (err)
22469 			return (err);
22470 	} else if (prof == 2) {
22471 		/*
22472 		 * Profile 2 is DGP. Less aggressive with
22473 		 * respect to client buffer level.
22474 		 */
22475 		rack->r_ctl.rc_dgp_bl_agg = DGP_LEVEL1;
22476 		err = rack_set_dgp(rack);
22477 		if (err)
22478 			return (err);
22479 	} else if (prof == 3) {
22480 		/*
22481 		 * Profile 3 is DGP. Even Less aggressive with
22482 		 * respect to client buffer level.
22483 		 */
22484 		rack->r_ctl.rc_dgp_bl_agg = DGP_LEVEL2;
22485 		err = rack_set_dgp(rack);
22486 		if (err)
22487 			return (err);
22488 	} else if (prof == 4) {
22489 		/*
22490 		 * Profile 4 is DGP with the most responsiveness
22491 		 * to client buffer level.
22492 		 */
22493 		rack->r_ctl.rc_dgp_bl_agg = DGP_LEVEL3;
22494 		err = rack_set_dgp(rack);
22495 		if (err)
22496 			return (err);
22497 	} else if (prof == 0) {
22498 		/* This changes things back to the default settings */
22499 		rack->dgp_on = 0;
22500 		rack->rc_hybrid_mode = 0;
22501 		err = 0;
22502 		if (rack_fill_cw_state)
22503 			rack->rc_pace_to_cwnd = 1;
22504 		else
22505 			rack->rc_pace_to_cwnd = 0;
22506 		if (rack->rc_always_pace) {
22507 			tcp_decrement_paced_conn();
22508 			rack_undo_cc_pacing(rack);
22509 			rack->rc_always_pace = 0;
22510 		}
22511 		if (rack_pace_every_seg && tcp_can_enable_pacing()) {
22512 			rack->rc_always_pace = 1;
22513 			if ((rack->gp_ready) && (rack->use_fixed_rate == 0))
22514 				rack_set_cc_pacing(rack);
22515 		} else
22516 			rack->rc_always_pace = 0;
22517 		if (rack_dsack_std_based & 0x1) {
22518 			/* Basically this means all rack timers are at least (srtt + 1/4 srtt) */
22519 			rack->rc_rack_tmr_std_based = 1;
22520 		}
22521 		if (rack_dsack_std_based & 0x2) {
22522 			/* Basically this means  rack timers are extended based on dsack by up to (2 * srtt) */
22523 			rack->rc_rack_use_dsack = 1;
22524 		}
22525 		if (rack_use_cmp_acks)
22526 			rack->r_use_cmp_ack = 1;
22527 		else
22528 			rack->r_use_cmp_ack = 0;
22529 		if (rack_disable_prr)
22530 			rack->rack_no_prr = 1;
22531 		else
22532 			rack->rack_no_prr = 0;
22533 		if (rack_gp_no_rec_chg)
22534 			rack->rc_gp_no_rec_chg = 1;
22535 		else
22536 			rack->rc_gp_no_rec_chg = 0;
22537 		if (rack_enable_mqueue_for_nonpaced || rack->r_use_cmp_ack) {
22538 			rack->r_mbuf_queue = 1;
22539 			if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state))
22540 				rack->rc_tp->t_flags2 |= TF2_MBUF_ACKCMP;
22541 			rack->rc_tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
22542 		} else {
22543 			rack->r_mbuf_queue = 0;
22544 			rack->rc_tp->t_flags2 &= ~TF2_SUPPORTS_MBUFQ;
22545 		}
22546 		if (rack_enable_shared_cwnd)
22547 			rack->rack_enable_scwnd = 1;
22548 		else
22549 			rack->rack_enable_scwnd = 0;
22550 		if (rack_do_dyn_mul) {
22551 			/* When dynamic adjustment is on CA needs to start at 100% */
22552 			rack->rc_gp_dyn_mul = 1;
22553 			if (rack_do_dyn_mul >= 100)
22554 				rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
22555 		} else {
22556 			rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
22557 			rack->rc_gp_dyn_mul = 0;
22558 		}
22559 		rack->r_rr_config = 0;
22560 		rack->r_ctl.rc_no_push_at_mrtt = 0;
22561 		rack->rc_pace_to_cwnd = 0;
22562 		rack->rc_pace_fill_if_rttin_range = 0;
22563 		rack->rtt_limit_mul = 0;
22564 
22565 		if (rack_enable_hw_pacing)
22566 			rack->rack_hdw_pace_ena = 1;
22567 		else
22568 			rack->rack_hdw_pace_ena = 0;
22569 		if (rack_disable_prr)
22570 			rack->rack_no_prr = 1;
22571 		else
22572 			rack->rack_no_prr = 0;
22573 		if (rack_limits_scwnd)
22574 			rack->r_limit_scw  = 1;
22575 		else
22576 			rack->r_limit_scw  = 0;
22577 		rack_init_retransmit_value(rack, rack_rxt_controls);
22578 		err = 0;
22579 	}
22580 	return (err);
22581 }
22582 
22583 static int
22584 rack_add_deferred_option(struct tcp_rack *rack, int sopt_name, uint64_t loptval)
22585 {
22586 	struct deferred_opt_list *dol;
22587 
22588 	dol = malloc(sizeof(struct deferred_opt_list),
22589 		     M_TCPFSB, M_NOWAIT|M_ZERO);
22590 	if (dol == NULL) {
22591 		/*
22592 		 * No space yikes -- fail out..
22593 		 */
22594 		return (0);
22595 	}
22596 	dol->optname = sopt_name;
22597 	dol->optval = loptval;
22598 	TAILQ_INSERT_TAIL(&rack->r_ctl.opt_list, dol, next);
22599 	return (1);
22600 }
22601 
22602 static int
22603 process_hybrid_pacing(struct tcp_rack *rack, struct tcp_hybrid_req *hybrid)
22604 {
22605 #ifdef TCP_REQUEST_TRK
22606 	struct http_sendfile_track *sft;
22607 	struct timeval tv;
22608 	tcp_seq seq;
22609 	int err;
22610 
22611 	microuptime(&tv);
22612 
22613 	/*
22614 	 * If BB logging is not on we need to look at the DTL flag.
22615 	 * If its on already then those reasons override the DTL input.
22616 	 * We do this with any request, you can turn DTL on, but it does
22617 	 * not turn off at least from hybrid pacing requests.
22618 	 */
22619 	if (tcp_bblogging_on(rack->rc_tp) == 0) {
22620 		if (hybrid->hybrid_flags & TCP_HYBRID_PACING_DTL) {
22621 			/* Turn on BB point logging  */
22622 			tcp_set_bblog_state(rack->rc_tp, TCP_LOG_VIA_BBPOINTS,
22623 					    TCP_BBPOINT_REQ_LEVEL_LOGGING);
22624 		}
22625 	}
22626 	/* Make sure no fixed rate is on */
22627 	rack->use_fixed_rate = 0;
22628 	rack->r_ctl.rc_fixed_pacing_rate_rec = 0;
22629 	rack->r_ctl.rc_fixed_pacing_rate_ca = 0;
22630 	rack->r_ctl.rc_fixed_pacing_rate_ss = 0;
22631 	/* Now allocate or find our entry that will have these settings */
22632 	sft = tcp_http_alloc_req_full(rack->rc_tp, &hybrid->req, tcp_tv_to_lusectick(&tv), 0);
22633 	if (sft == NULL) {
22634 		rack->rc_tp->tcp_hybrid_error++;
22635 		/* no space, where would it have gone? */
22636 		seq = rack->rc_tp->snd_una + rack->rc_tp->t_inpcb.inp_socket->so_snd.sb_ccc;
22637 		rack_log_hybrid(rack, seq, NULL, HYBRID_LOG_NO_ROOM, __LINE__, 0);
22638 		return (ENOSPC);
22639 	}
22640 	/* The seq will be snd_una + everything in the buffer */
22641 	seq = sft->start_seq;
22642 	if ((hybrid->hybrid_flags & TCP_HYBRID_PACING_ENABLE) == 0) {
22643 		/* Disabling hybrid pacing */
22644 		if (rack->rc_hybrid_mode) {
22645 			rack_set_profile(rack, 0);
22646 			rack->rc_tp->tcp_hybrid_stop++;
22647 		}
22648 		rack_log_hybrid(rack, seq, sft, HYBRID_LOG_TURNED_OFF, __LINE__, 0);
22649 		return (0);
22650 	}
22651 	if (rack->dgp_on == 0) {
22652 		/*
22653 		 * If we have not yet turned DGP on, do so
22654 		 * now setting pure DGP mode, no buffer level
22655 		 * response.
22656 		 */
22657 		if ((err = rack_set_profile(rack, 1)) != 0){
22658 			/* Failed to turn pacing on */
22659 			rack->rc_tp->tcp_hybrid_error++;
22660 			rack_log_hybrid(rack, seq, sft, HYBRID_LOG_NO_PACING, __LINE__, 0);
22661 			return (err);
22662 		}
22663 	}
22664 	/* Now set in our flags */
22665 	sft->hybrid_flags = hybrid->hybrid_flags;
22666 	if (hybrid->hybrid_flags & TCP_HYBRID_PACING_CSPR)
22667 		sft->cspr = hybrid->cspr;
22668 	else
22669 		sft->cspr = 0;
22670 	if (hybrid->hybrid_flags & TCP_HYBRID_PACING_H_MS)
22671 		sft->hint_maxseg = hybrid->hint_maxseg;
22672 	else
22673 		sft->hint_maxseg = 0;
22674 	rack->rc_hybrid_mode = 1;
22675 	rack->rc_tp->tcp_hybrid_start++;
22676 	rack_log_hybrid(rack, seq, sft, HYBRID_LOG_RULES_SET, __LINE__,0);
22677 	return (0);
22678 #else
22679 	return (ENOTSUP);
22680 #endif
22681 }
22682 
22683 static int
22684 rack_process_option(struct tcpcb *tp, struct tcp_rack *rack, int sopt_name,
22685 		    uint32_t optval, uint64_t loptval, struct tcp_hybrid_req *hybrid)
22686 
22687 {
22688 	struct epoch_tracker et;
22689 	struct sockopt sopt;
22690 	struct cc_newreno_opts opt;
22691 	uint64_t val;
22692 	int error = 0;
22693 	uint16_t ca, ss;
22694 
22695 	switch (sopt_name) {
22696 	case TCP_RACK_SET_RXT_OPTIONS:
22697 		if ((optval >= 0) && (optval <= 2)) {
22698 			rack_init_retransmit_value(rack, optval);
22699 		} else {
22700 			/*
22701 			 * You must send in 0, 1 or 2 all else is
22702 			 * invalid.
22703 			 */
22704 			error = EINVAL;
22705 		}
22706 		break;
22707 	case TCP_RACK_DSACK_OPT:
22708 		RACK_OPTS_INC(tcp_rack_dsack_opt);
22709 		if (optval & 0x1) {
22710 			rack->rc_rack_tmr_std_based = 1;
22711 		} else {
22712 			rack->rc_rack_tmr_std_based = 0;
22713 		}
22714 		if (optval & 0x2) {
22715 			rack->rc_rack_use_dsack = 1;
22716 		} else {
22717 			rack->rc_rack_use_dsack = 0;
22718 		}
22719 		rack_log_dsack_event(rack, 5, __LINE__, 0, 0);
22720 		break;
22721 	case TCP_RACK_PACING_DIVISOR:
22722 		RACK_OPTS_INC(tcp_rack_pacing_divisor);
22723 		if (optval == 0) {
22724 			rack->r_ctl.pace_len_divisor = rack_default_pacing_divisor;
22725 		} else {
22726 			if (optval < RL_MIN_DIVISOR)
22727 				rack->r_ctl.pace_len_divisor = RL_MIN_DIVISOR;
22728 			else
22729 				rack->r_ctl.pace_len_divisor = optval;
22730 		}
22731 		break;
22732 	case TCP_RACK_HI_BETA:
22733 		RACK_OPTS_INC(tcp_rack_hi_beta);
22734 		if (optval)
22735 			rack->rack_hibeta = 1;
22736 		else
22737 			rack->rack_hibeta = 0;
22738 		break;
22739 	case TCP_RACK_PACING_BETA:
22740 		RACK_OPTS_INC(tcp_rack_beta);
22741 		if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0) {
22742 			/* This only works for newreno. */
22743 			error = EINVAL;
22744 			break;
22745 		}
22746 		if (rack->rc_pacing_cc_set) {
22747 			/*
22748 			 * Set them into the real CC module
22749 			 * whats in the rack pcb is the old values
22750 			 * to be used on restoral/
22751 			 */
22752 			sopt.sopt_dir = SOPT_SET;
22753 			opt.name = CC_NEWRENO_BETA;
22754 			opt.val = optval;
22755 			if (CC_ALGO(tp)->ctl_output != NULL)
22756 				error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
22757 			else {
22758 				error = ENOENT;
22759 				break;
22760 			}
22761 		} else {
22762 			/*
22763 			 * Not pacing yet so set it into our local
22764 			 * rack pcb storage.
22765 			 */
22766 			rack->r_ctl.rc_saved_beta.beta = optval;
22767 		}
22768 		break;
22769 	case TCP_RACK_TIMER_SLOP:
22770 		RACK_OPTS_INC(tcp_rack_timer_slop);
22771 		rack->r_ctl.timer_slop = optval;
22772 		if (rack->rc_tp->t_srtt) {
22773 			/*
22774 			 * If we have an SRTT lets update t_rxtcur
22775 			 * to have the new slop.
22776 			 */
22777 			RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
22778 					   rack_rto_min, rack_rto_max,
22779 					   rack->r_ctl.timer_slop);
22780 		}
22781 		break;
22782 	case TCP_RACK_PACING_BETA_ECN:
22783 		RACK_OPTS_INC(tcp_rack_beta_ecn);
22784 		if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0) {
22785 			/* This only works for newreno. */
22786 			error = EINVAL;
22787 			break;
22788 		}
22789 		if (rack->rc_pacing_cc_set) {
22790 			/*
22791 			 * Set them into the real CC module
22792 			 * whats in the rack pcb is the old values
22793 			 * to be used on restoral/
22794 			 */
22795 			sopt.sopt_dir = SOPT_SET;
22796 			opt.name = CC_NEWRENO_BETA_ECN;
22797 			opt.val = optval;
22798 			if (CC_ALGO(tp)->ctl_output != NULL)
22799 				error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
22800 			else
22801 				error = ENOENT;
22802 		} else {
22803 			/*
22804 			 * Not pacing yet so set it into our local
22805 			 * rack pcb storage.
22806 			 */
22807 			rack->r_ctl.rc_saved_beta.beta_ecn = optval;
22808 			rack->r_ctl.rc_saved_beta.newreno_flags = CC_NEWRENO_BETA_ECN_ENABLED;
22809 		}
22810 		break;
22811 	case TCP_DEFER_OPTIONS:
22812 		RACK_OPTS_INC(tcp_defer_opt);
22813 		if (optval) {
22814 			if (rack->gp_ready) {
22815 				/* Too late */
22816 				error = EINVAL;
22817 				break;
22818 			}
22819 			rack->defer_options = 1;
22820 		} else
22821 			rack->defer_options = 0;
22822 		break;
22823 	case TCP_RACK_MEASURE_CNT:
22824 		RACK_OPTS_INC(tcp_rack_measure_cnt);
22825 		if (optval && (optval <= 0xff)) {
22826 			rack->r_ctl.req_measurements = optval;
22827 		} else
22828 			error = EINVAL;
22829 		break;
22830 	case TCP_REC_ABC_VAL:
22831 		RACK_OPTS_INC(tcp_rec_abc_val);
22832 		if (optval > 0)
22833 			rack->r_use_labc_for_rec = 1;
22834 		else
22835 			rack->r_use_labc_for_rec = 0;
22836 		break;
22837 	case TCP_RACK_ABC_VAL:
22838 		RACK_OPTS_INC(tcp_rack_abc_val);
22839 		if ((optval > 0) && (optval < 255))
22840 			rack->rc_labc = optval;
22841 		else
22842 			error = EINVAL;
22843 		break;
22844 	case TCP_HDWR_UP_ONLY:
22845 		RACK_OPTS_INC(tcp_pacing_up_only);
22846 		if (optval)
22847 			rack->r_up_only = 1;
22848 		else
22849 			rack->r_up_only = 0;
22850 		break;
22851 	case TCP_PACING_RATE_CAP:
22852 		RACK_OPTS_INC(tcp_pacing_rate_cap);
22853 		rack->r_ctl.bw_rate_cap = loptval;
22854 		break;
22855 	case TCP_HYBRID_PACING:
22856 		if (hybrid == NULL) {
22857 			error = EINVAL;
22858 			break;
22859 		}
22860 		error = process_hybrid_pacing(rack, hybrid);
22861 		break;
22862 	case TCP_RACK_PROFILE:
22863 		RACK_OPTS_INC(tcp_profile);
22864 		error = rack_set_profile(rack, optval);
22865 		break;
22866 	case TCP_USE_CMP_ACKS:
22867 		RACK_OPTS_INC(tcp_use_cmp_acks);
22868 		if ((optval == 0) && (tp->t_flags2 & TF2_MBUF_ACKCMP)) {
22869 			/* You can't turn it off once its on! */
22870 			error = EINVAL;
22871 		} else if ((optval == 1) && (rack->r_use_cmp_ack == 0)) {
22872 			rack->r_use_cmp_ack = 1;
22873 			rack->r_mbuf_queue = 1;
22874 			tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
22875 		}
22876 		if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
22877 			tp->t_flags2 |= TF2_MBUF_ACKCMP;
22878 		break;
22879 	case TCP_SHARED_CWND_TIME_LIMIT:
22880 		RACK_OPTS_INC(tcp_lscwnd);
22881 		if (optval)
22882 			rack->r_limit_scw = 1;
22883 		else
22884 			rack->r_limit_scw = 0;
22885 		break;
22886 	case TCP_RACK_DGP_IN_REC:
22887 		RACK_OPTS_INC(tcp_dgp_in_rec);
22888 		if (optval)
22889 			rack->r_ctl.full_dgp_in_rec = 1;
22890 		else
22891 			rack->r_ctl.full_dgp_in_rec = 0;
22892 		break;
22893 	case TCP_RXT_CLAMP:
22894 		RACK_OPTS_INC(tcp_rxt_clamp);
22895 		rack_translate_clamp_value(rack, optval);
22896 		break;
22897  	case TCP_RACK_PACE_TO_FILL:
22898 		RACK_OPTS_INC(tcp_fillcw);
22899 		if (optval == 0)
22900 			rack->rc_pace_to_cwnd = 0;
22901 		else {
22902 			rack->rc_pace_to_cwnd = 1;
22903 			if (optval > 1)
22904 				rack->r_fill_less_agg = 1;
22905 		}
22906 		if ((optval >= rack_gp_rtt_maxmul) &&
22907 		    rack_gp_rtt_maxmul &&
22908 		    (optval < 0xf)) {
22909 			rack->rc_pace_fill_if_rttin_range = 1;
22910 			rack->rtt_limit_mul = optval;
22911 		} else {
22912 			rack->rc_pace_fill_if_rttin_range = 0;
22913 			rack->rtt_limit_mul = 0;
22914 		}
22915 		break;
22916 	case TCP_RACK_NO_PUSH_AT_MAX:
22917 		RACK_OPTS_INC(tcp_npush);
22918 		if (optval == 0)
22919 			rack->r_ctl.rc_no_push_at_mrtt = 0;
22920 		else if (optval < 0xff)
22921 			rack->r_ctl.rc_no_push_at_mrtt = optval;
22922 		else
22923 			error = EINVAL;
22924 		break;
22925 	case TCP_SHARED_CWND_ENABLE:
22926 		RACK_OPTS_INC(tcp_rack_scwnd);
22927 		if (optval == 0)
22928 			rack->rack_enable_scwnd = 0;
22929 		else
22930 			rack->rack_enable_scwnd = 1;
22931 		break;
22932 	case TCP_RACK_MBUF_QUEUE:
22933 		/* Now do we use the LRO mbuf-queue feature */
22934 		RACK_OPTS_INC(tcp_rack_mbufq);
22935 		if (optval || rack->r_use_cmp_ack)
22936 			rack->r_mbuf_queue = 1;
22937 		else
22938 			rack->r_mbuf_queue = 0;
22939 		if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
22940 			tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
22941 		else
22942 			tp->t_flags2 &= ~TF2_SUPPORTS_MBUFQ;
22943 		break;
22944 	case TCP_RACK_NONRXT_CFG_RATE:
22945 		RACK_OPTS_INC(tcp_rack_cfg_rate);
22946 		if (optval == 0)
22947 			rack->rack_rec_nonrxt_use_cr = 0;
22948 		else
22949 			rack->rack_rec_nonrxt_use_cr = 1;
22950 		break;
22951 	case TCP_NO_PRR:
22952 		RACK_OPTS_INC(tcp_rack_noprr);
22953 		if (optval == 0)
22954 			rack->rack_no_prr = 0;
22955 		else if (optval == 1)
22956 			rack->rack_no_prr = 1;
22957 		else if (optval == 2)
22958 			rack->no_prr_addback = 1;
22959 		else
22960 			error = EINVAL;
22961 		break;
22962 	case TCP_TIMELY_DYN_ADJ:
22963 		RACK_OPTS_INC(tcp_timely_dyn);
22964 		if (optval == 0)
22965 			rack->rc_gp_dyn_mul = 0;
22966 		else {
22967 			rack->rc_gp_dyn_mul = 1;
22968 			if (optval >= 100) {
22969 				/*
22970 				 * If the user sets something 100 or more
22971 				 * its the gp_ca value.
22972 				 */
22973 				rack->r_ctl.rack_per_of_gp_ca  = optval;
22974 			}
22975 		}
22976 		break;
22977 	case TCP_RACK_DO_DETECTION:
22978 		RACK_OPTS_INC(tcp_rack_do_detection);
22979 		if (optval == 0)
22980 			rack->do_detection = 0;
22981 		else
22982 			rack->do_detection = 1;
22983 		break;
22984 	case TCP_RACK_TLP_USE:
22985 		if ((optval < TLP_USE_ID) || (optval > TLP_USE_TWO_TWO)) {
22986 			error = EINVAL;
22987 			break;
22988 		}
22989 		RACK_OPTS_INC(tcp_tlp_use);
22990 		rack->rack_tlp_threshold_use = optval;
22991 		break;
22992 	case TCP_RACK_TLP_REDUCE:
22993 		/* RACK TLP cwnd reduction (bool) */
22994 		RACK_OPTS_INC(tcp_rack_tlp_reduce);
22995 		rack->r_ctl.rc_tlp_cwnd_reduce = optval;
22996 		break;
22997 		/*  Pacing related ones */
22998 	case TCP_RACK_PACE_ALWAYS:
22999 		/*
23000 		 * zero is old rack method, 1 is new
23001 		 * method using a pacing rate.
23002 		 */
23003 		RACK_OPTS_INC(tcp_rack_pace_always);
23004 		if (optval > 0) {
23005 			if (rack->rc_always_pace) {
23006 				error = EALREADY;
23007 				break;
23008 			} else if (tcp_can_enable_pacing()) {
23009 				rack->rc_always_pace = 1;
23010 				if ((rack->gp_ready) && (rack->use_fixed_rate == 0))
23011 					rack_set_cc_pacing(rack);
23012 			}
23013 			else {
23014 				error = ENOSPC;
23015 				break;
23016 			}
23017 		} else {
23018 			if (rack->rc_always_pace) {
23019 				tcp_decrement_paced_conn();
23020 				rack->rc_always_pace = 0;
23021 				rack_undo_cc_pacing(rack);
23022 			}
23023 		}
23024 		if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
23025 			tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
23026 		else
23027 			tp->t_flags2 &= ~TF2_SUPPORTS_MBUFQ;
23028 		/* A rate may be set irate or other, if so set seg size */
23029 		rack_update_seg(rack);
23030 		break;
23031 	case TCP_BBR_RACK_INIT_RATE:
23032 		RACK_OPTS_INC(tcp_initial_rate);
23033 		val = optval;
23034 		/* Change from kbits per second to bytes per second */
23035 		val *= 1000;
23036 		val /= 8;
23037 		rack->r_ctl.init_rate = val;
23038 		if (rack->rc_init_win != rack_default_init_window) {
23039 			uint32_t win, snt;
23040 
23041 			/*
23042 			 * Options don't always get applied
23043 			 * in the order you think. So in order
23044 			 * to assure we update a cwnd we need
23045 			 * to check and see if we are still
23046 			 * where we should raise the cwnd.
23047 			 */
23048 			win = rc_init_window(rack);
23049 			if (SEQ_GT(tp->snd_max, tp->iss))
23050 				snt = tp->snd_max - tp->iss;
23051 			else
23052 				snt = 0;
23053 			if ((snt < win) &&
23054 			    (tp->snd_cwnd < win))
23055 				tp->snd_cwnd = win;
23056 		}
23057 		if (rack->rc_always_pace)
23058 			rack_update_seg(rack);
23059 		break;
23060 	case TCP_BBR_IWINTSO:
23061 		RACK_OPTS_INC(tcp_initial_win);
23062 		if (optval && (optval <= 0xff)) {
23063 			uint32_t win, snt;
23064 
23065 			rack->rc_init_win = optval;
23066 			win = rc_init_window(rack);
23067 			if (SEQ_GT(tp->snd_max, tp->iss))
23068 				snt = tp->snd_max - tp->iss;
23069 			else
23070 				snt = 0;
23071 			if ((snt < win) &&
23072 			    (tp->t_srtt |
23073 			     rack->r_ctl.init_rate)) {
23074 				/*
23075 				 * We are not past the initial window
23076 				 * and we have some bases for pacing,
23077 				 * so we need to possibly adjust up
23078 				 * the cwnd. Note even if we don't set
23079 				 * the cwnd, its still ok to raise the rc_init_win
23080 				 * which can be used coming out of idle when we
23081 				 * would have a rate.
23082 				 */
23083 				if (tp->snd_cwnd < win)
23084 					tp->snd_cwnd = win;
23085 			}
23086 			if (rack->rc_always_pace)
23087 				rack_update_seg(rack);
23088 		} else
23089 			error = EINVAL;
23090 		break;
23091 	case TCP_RACK_FORCE_MSEG:
23092 		RACK_OPTS_INC(tcp_rack_force_max_seg);
23093 		if (optval)
23094 			rack->rc_force_max_seg = 1;
23095 		else
23096 			rack->rc_force_max_seg = 0;
23097 		break;
23098 	case TCP_RACK_PACE_MIN_SEG:
23099 		RACK_OPTS_INC(tcp_rack_min_seg);
23100 		rack->r_ctl.rc_user_set_min_segs = (0x0000ffff & optval);
23101 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
23102 		break;
23103 	case TCP_RACK_PACE_MAX_SEG:
23104 		/* Max segments size in a pace in bytes */
23105 		RACK_OPTS_INC(tcp_rack_max_seg);
23106 		rack->rc_user_set_max_segs = optval;
23107 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
23108 		break;
23109 	case TCP_RACK_PACE_RATE_REC:
23110 		/* Set the fixed pacing rate in Bytes per second ca */
23111 		RACK_OPTS_INC(tcp_rack_pace_rate_rec);
23112 		rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
23113 		if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
23114 			rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
23115 		if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
23116 			rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
23117 		rack->use_fixed_rate = 1;
23118 		if (rack->rc_always_pace && rack->gp_ready && rack->rack_hibeta)
23119 			rack_set_cc_pacing(rack);
23120 		rack_log_pacing_delay_calc(rack,
23121 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
23122 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
23123 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
23124 					   __LINE__, NULL,0);
23125 		break;
23126 
23127 	case TCP_RACK_PACE_RATE_SS:
23128 		/* Set the fixed pacing rate in Bytes per second ca */
23129 		RACK_OPTS_INC(tcp_rack_pace_rate_ss);
23130 		rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
23131 		if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
23132 			rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
23133 		if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
23134 			rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
23135 		rack->use_fixed_rate = 1;
23136 		if (rack->rc_always_pace && rack->gp_ready && rack->rack_hibeta)
23137 			rack_set_cc_pacing(rack);
23138 		rack_log_pacing_delay_calc(rack,
23139 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
23140 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
23141 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
23142 					   __LINE__, NULL, 0);
23143 		break;
23144 
23145 	case TCP_RACK_PACE_RATE_CA:
23146 		/* Set the fixed pacing rate in Bytes per second ca */
23147 		RACK_OPTS_INC(tcp_rack_pace_rate_ca);
23148 		rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
23149 		if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
23150 			rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
23151 		if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
23152 			rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
23153 		rack->use_fixed_rate = 1;
23154 		if (rack->rc_always_pace && rack->gp_ready && rack->rack_hibeta)
23155 			rack_set_cc_pacing(rack);
23156 		rack_log_pacing_delay_calc(rack,
23157 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
23158 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
23159 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
23160 					   __LINE__, NULL, 0);
23161 		break;
23162 	case TCP_RACK_GP_INCREASE_REC:
23163 		RACK_OPTS_INC(tcp_gp_inc_rec);
23164 		rack->r_ctl.rack_per_of_gp_rec = optval;
23165 		rack_log_pacing_delay_calc(rack,
23166 					   rack->r_ctl.rack_per_of_gp_ss,
23167 					   rack->r_ctl.rack_per_of_gp_ca,
23168 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
23169 					   __LINE__, NULL, 0);
23170 		break;
23171 	case TCP_RACK_GP_INCREASE_CA:
23172 		RACK_OPTS_INC(tcp_gp_inc_ca);
23173 		ca = optval;
23174 		if (ca < 100) {
23175 			/*
23176 			 * We don't allow any reduction
23177 			 * over the GP b/w.
23178 			 */
23179 			error = EINVAL;
23180 			break;
23181 		}
23182 		rack->r_ctl.rack_per_of_gp_ca = ca;
23183 		rack_log_pacing_delay_calc(rack,
23184 					   rack->r_ctl.rack_per_of_gp_ss,
23185 					   rack->r_ctl.rack_per_of_gp_ca,
23186 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
23187 					   __LINE__, NULL, 0);
23188 		break;
23189 	case TCP_RACK_GP_INCREASE_SS:
23190 		RACK_OPTS_INC(tcp_gp_inc_ss);
23191 		ss = optval;
23192 		if (ss < 100) {
23193 			/*
23194 			 * We don't allow any reduction
23195 			 * over the GP b/w.
23196 			 */
23197 			error = EINVAL;
23198 			break;
23199 		}
23200 		rack->r_ctl.rack_per_of_gp_ss = ss;
23201 		rack_log_pacing_delay_calc(rack,
23202 					   rack->r_ctl.rack_per_of_gp_ss,
23203 					   rack->r_ctl.rack_per_of_gp_ca,
23204 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
23205 					   __LINE__, NULL, 0);
23206 		break;
23207 	case TCP_RACK_RR_CONF:
23208 		RACK_OPTS_INC(tcp_rack_rrr_no_conf_rate);
23209 		if (optval && optval <= 3)
23210 			rack->r_rr_config = optval;
23211 		else
23212 			rack->r_rr_config = 0;
23213 		break;
23214 	case TCP_PACING_DND:			/*  URL:dnd */
23215 		if (optval > 0)
23216 			rack->rc_pace_dnd = 1;
23217 		else
23218 			rack->rc_pace_dnd = 0;
23219 		break;
23220 	case TCP_HDWR_RATE_CAP:
23221 		RACK_OPTS_INC(tcp_hdwr_rate_cap);
23222 		if (optval) {
23223 			if (rack->r_rack_hw_rate_caps == 0)
23224 				rack->r_rack_hw_rate_caps = 1;
23225 			else
23226 				error = EALREADY;
23227 		} else {
23228 			rack->r_rack_hw_rate_caps = 0;
23229 		}
23230 		break;
23231 	case TCP_RACK_SPLIT_LIMIT:
23232 		RACK_OPTS_INC(tcp_split_limit);
23233 		rack->r_ctl.rc_split_limit = optval;
23234 		break;
23235 	case TCP_BBR_HDWR_PACE:
23236 		RACK_OPTS_INC(tcp_hdwr_pacing);
23237 		if (optval){
23238 			if (rack->rack_hdrw_pacing == 0) {
23239 				rack->rack_hdw_pace_ena = 1;
23240 				rack->rack_attempt_hdwr_pace = 0;
23241 			} else
23242 				error = EALREADY;
23243 		} else {
23244 			rack->rack_hdw_pace_ena = 0;
23245 #ifdef RATELIMIT
23246 			if (rack->r_ctl.crte != NULL) {
23247 				rack->rack_hdrw_pacing = 0;
23248 				rack->rack_attempt_hdwr_pace = 0;
23249 				tcp_rel_pacing_rate(rack->r_ctl.crte, tp);
23250 				rack->r_ctl.crte = NULL;
23251 			}
23252 #endif
23253 		}
23254 		break;
23255 		/*  End Pacing related ones */
23256 	case TCP_RACK_PRR_SENDALOT:
23257 		/* Allow PRR to send more than one seg */
23258 		RACK_OPTS_INC(tcp_rack_prr_sendalot);
23259 		rack->r_ctl.rc_prr_sendalot = optval;
23260 		break;
23261 	case TCP_RACK_MIN_TO:
23262 		/* Minimum time between rack t-o's in ms */
23263 		RACK_OPTS_INC(tcp_rack_min_to);
23264 		rack->r_ctl.rc_min_to = optval;
23265 		break;
23266 	case TCP_RACK_EARLY_SEG:
23267 		/* If early recovery max segments */
23268 		RACK_OPTS_INC(tcp_rack_early_seg);
23269 		rack->r_ctl.rc_early_recovery_segs = optval;
23270 		break;
23271 	case TCP_RACK_ENABLE_HYSTART:
23272 	{
23273 		if (optval) {
23274 			tp->t_ccv.flags |= CCF_HYSTART_ALLOWED;
23275 			if (rack_do_hystart > RACK_HYSTART_ON)
23276 				tp->t_ccv.flags |= CCF_HYSTART_CAN_SH_CWND;
23277 			if (rack_do_hystart > RACK_HYSTART_ON_W_SC)
23278 				tp->t_ccv.flags |= CCF_HYSTART_CONS_SSTH;
23279 		} else {
23280 			tp->t_ccv.flags &= ~(CCF_HYSTART_ALLOWED|CCF_HYSTART_CAN_SH_CWND|CCF_HYSTART_CONS_SSTH);
23281 		}
23282 	}
23283 	break;
23284 	case TCP_RACK_REORD_THRESH:
23285 		/* RACK reorder threshold (shift amount) */
23286 		RACK_OPTS_INC(tcp_rack_reord_thresh);
23287 		if ((optval > 0) && (optval < 31))
23288 			rack->r_ctl.rc_reorder_shift = optval;
23289 		else
23290 			error = EINVAL;
23291 		break;
23292 	case TCP_RACK_REORD_FADE:
23293 		/* Does reordering fade after ms time */
23294 		RACK_OPTS_INC(tcp_rack_reord_fade);
23295 		rack->r_ctl.rc_reorder_fade = optval;
23296 		break;
23297 	case TCP_RACK_TLP_THRESH:
23298 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
23299 		RACK_OPTS_INC(tcp_rack_tlp_thresh);
23300 		if (optval)
23301 			rack->r_ctl.rc_tlp_threshold = optval;
23302 		else
23303 			error = EINVAL;
23304 		break;
23305 	case TCP_BBR_USE_RACK_RR:
23306 		RACK_OPTS_INC(tcp_rack_rr);
23307 		if (optval)
23308 			rack->use_rack_rr = 1;
23309 		else
23310 			rack->use_rack_rr = 0;
23311 		break;
23312 	case TCP_RACK_PKT_DELAY:
23313 		/* RACK added ms i.e. rack-rtt + reord + N */
23314 		RACK_OPTS_INC(tcp_rack_pkt_delay);
23315 		rack->r_ctl.rc_pkt_delay = optval;
23316 		break;
23317 	case TCP_DELACK:
23318 		RACK_OPTS_INC(tcp_rack_delayed_ack);
23319 		if (optval == 0)
23320 			tp->t_delayed_ack = 0;
23321 		else
23322 			tp->t_delayed_ack = 1;
23323 		if (tp->t_flags & TF_DELACK) {
23324 			tp->t_flags &= ~TF_DELACK;
23325 			tp->t_flags |= TF_ACKNOW;
23326 			NET_EPOCH_ENTER(et);
23327 			rack_output(tp);
23328 			NET_EPOCH_EXIT(et);
23329 		}
23330 		break;
23331 
23332 	case TCP_BBR_RACK_RTT_USE:
23333 		RACK_OPTS_INC(tcp_rack_rtt_use);
23334 		if ((optval != USE_RTT_HIGH) &&
23335 		    (optval != USE_RTT_LOW) &&
23336 		    (optval != USE_RTT_AVG))
23337 			error = EINVAL;
23338 		else
23339 			rack->r_ctl.rc_rate_sample_method = optval;
23340 		break;
23341 	case TCP_DATA_AFTER_CLOSE:
23342 		RACK_OPTS_INC(tcp_data_after_close);
23343 		if (optval)
23344 			rack->rc_allow_data_af_clo = 1;
23345 		else
23346 			rack->rc_allow_data_af_clo = 0;
23347 		break;
23348 	default:
23349 		break;
23350 	}
23351 	tcp_log_socket_option(tp, sopt_name, optval, error);
23352 	return (error);
23353 }
23354 
23355 
23356 static void
23357 rack_apply_deferred_options(struct tcp_rack *rack)
23358 {
23359 	struct deferred_opt_list *dol, *sdol;
23360 	uint32_t s_optval;
23361 
23362 	TAILQ_FOREACH_SAFE(dol, &rack->r_ctl.opt_list, next, sdol) {
23363 		TAILQ_REMOVE(&rack->r_ctl.opt_list, dol, next);
23364 		/* Disadvantage of deferal is you loose the error return */
23365 		s_optval = (uint32_t)dol->optval;
23366 		(void)rack_process_option(rack->rc_tp, rack, dol->optname, s_optval, dol->optval, NULL);
23367 		free(dol, M_TCPDO);
23368 	}
23369 }
23370 
23371 static void
23372 rack_hw_tls_change(struct tcpcb *tp, int chg)
23373 {
23374 	/* Update HW tls state */
23375 	struct tcp_rack *rack;
23376 
23377 	rack = (struct tcp_rack *)tp->t_fb_ptr;
23378 	if (chg)
23379 		rack->r_ctl.fsb.hw_tls = 1;
23380 	else
23381 		rack->r_ctl.fsb.hw_tls = 0;
23382 }
23383 
23384 static int
23385 rack_pru_options(struct tcpcb *tp, int flags)
23386 {
23387 	if (flags & PRUS_OOB)
23388 		return (EOPNOTSUPP);
23389 	return (0);
23390 }
23391 
23392 static bool
23393 rack_wake_check(struct tcpcb *tp)
23394 {
23395 	struct tcp_rack *rack;
23396 	struct timeval tv;
23397 	uint32_t cts;
23398 
23399 	rack = (struct tcp_rack *)tp->t_fb_ptr;
23400 	if (rack->r_ctl.rc_hpts_flags) {
23401 		cts = tcp_get_usecs(&tv);
23402 		if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == PACE_PKT_OUTPUT){
23403 			/*
23404 			 * Pacing timer is up, check if we are ready.
23405 			 */
23406 			if (TSTMP_GEQ(cts, rack->r_ctl.rc_last_output_to))
23407 				return (true);
23408 		} else if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) != 0) {
23409 			/*
23410 			 * A timer is up, check if we are ready.
23411 			 */
23412 			if (TSTMP_GEQ(cts, rack->r_ctl.rc_timer_exp))
23413 				return (true);
23414 		}
23415 	}
23416 	return (false);
23417 }
23418 
23419 static struct tcp_function_block __tcp_rack = {
23420 	.tfb_tcp_block_name = __XSTRING(STACKNAME),
23421 	.tfb_tcp_output = rack_output,
23422 	.tfb_do_queued_segments = ctf_do_queued_segments,
23423 	.tfb_do_segment_nounlock = rack_do_segment_nounlock,
23424 	.tfb_tcp_do_segment = rack_do_segment,
23425 	.tfb_tcp_ctloutput = rack_ctloutput,
23426 	.tfb_tcp_fb_init = rack_init,
23427 	.tfb_tcp_fb_fini = rack_fini,
23428 	.tfb_tcp_timer_stop_all = rack_stopall,
23429 	.tfb_tcp_rexmit_tmr = rack_remxt_tmr,
23430 	.tfb_tcp_handoff_ok = rack_handoff_ok,
23431 	.tfb_tcp_mtu_chg = rack_mtu_change,
23432 	.tfb_pru_options = rack_pru_options,
23433 	.tfb_hwtls_change = rack_hw_tls_change,
23434 	.tfb_chg_query = rack_chg_query,
23435 	.tfb_switch_failed = rack_switch_failed,
23436 	.tfb_early_wake_check = rack_wake_check,
23437 	.tfb_compute_pipe = rack_compute_pipe,
23438 	.tfb_flags = TCP_FUNC_OUTPUT_CANDROP,
23439 };
23440 
23441 /*
23442  * rack_ctloutput() must drop the inpcb lock before performing copyin on
23443  * socket option arguments.  When it re-acquires the lock after the copy, it
23444  * has to revalidate that the connection is still valid for the socket
23445  * option.
23446  */
23447 static int
23448 rack_set_sockopt(struct tcpcb *tp, struct sockopt *sopt)
23449 {
23450 	struct inpcb *inp = tptoinpcb(tp);
23451 #ifdef INET6
23452 	struct ip6_hdr *ip6;
23453 	int32_t mask, tclass;
23454 #endif
23455 #ifdef INET
23456 	struct ip *ip;
23457 #endif
23458 	struct tcp_rack *rack;
23459 	struct tcp_hybrid_req hybrid;
23460 	uint64_t loptval;
23461 	int32_t error = 0, optval;
23462 
23463 	rack = (struct tcp_rack *)tp->t_fb_ptr;
23464 	if (rack == NULL) {
23465 		INP_WUNLOCK(inp);
23466 		return (EINVAL);
23467 	}
23468 #ifdef INET6
23469 	ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
23470 #endif
23471 #ifdef INET
23472 	ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
23473 #endif
23474 
23475 	switch (sopt->sopt_level) {
23476 #ifdef INET6
23477 	case IPPROTO_IPV6:
23478 		MPASS(inp->inp_vflag & INP_IPV6PROTO);
23479 		switch (sopt->sopt_name) {
23480 		case IPV6_USE_MIN_MTU:
23481 			tcp6_use_min_mtu(tp);
23482 			break;
23483 		case IPV6_TCLASS:
23484 			/*
23485 			 * The DSCP codepoint has changed, update the fsb
23486 			 * by overwriting any previous traffic class.
23487 			 */
23488 			if (inp->in6p_outputopts) {
23489 				mask = 0xfc;
23490 				tclass = inp->in6p_outputopts->ip6po_tclass;
23491 				ip6->ip6_flow &= htonl((~mask) << 20);
23492 				ip6->ip6_flow |= htonl((tclass & mask) << 20);
23493 			}
23494 			break;
23495 		}
23496 		INP_WUNLOCK(inp);
23497 		return (0);
23498 #endif
23499 #ifdef INET
23500 	case IPPROTO_IP:
23501 		switch (sopt->sopt_name) {
23502 		case IP_TOS:
23503 			/*
23504 			 * The DSCP codepoint has changed, update the fsb.
23505 			 */
23506 			ip->ip_tos = rack->rc_inp->inp_ip_tos;
23507 			break;
23508 		case IP_TTL:
23509 			/*
23510 			 * The TTL has changed, update the fsb.
23511 			 */
23512 			ip->ip_ttl = rack->rc_inp->inp_ip_ttl;
23513 			break;
23514 		}
23515 		INP_WUNLOCK(inp);
23516 		return (0);
23517 #endif
23518 #ifdef SO_PEERPRIO
23519 	case SOL_SOCKET:
23520 		switch (sopt->sopt_name) {
23521 		case SO_PEERPRIO:			/*  SC-URL:bs */
23522 			/* Already read in and sanity checked in sosetopt(). */
23523 			if (inp->inp_socket) {
23524 				rack->client_bufferlvl = inp->inp_socket->so_peerprio;
23525 				rack_client_buffer_level_set(rack);
23526 			}
23527 			break;
23528 		}
23529 		INP_WUNLOCK(inp);
23530 		return (0);
23531 #endif
23532 	case IPPROTO_TCP:
23533 		switch (sopt->sopt_name) {
23534 		case TCP_RACK_TLP_REDUCE:		/*  URL:tlp_reduce */
23535 		/*  Pacing related ones */
23536 		case TCP_RACK_PACE_ALWAYS:		/*  URL:pace_always */
23537 		case TCP_BBR_RACK_INIT_RATE:		/*  URL:irate */
23538 		case TCP_BBR_IWINTSO:			/*  URL:tso_iwin */
23539 		case TCP_RACK_PACE_MIN_SEG:		/*  URL:pace_min_seg */
23540 		case TCP_RACK_PACE_MAX_SEG:		/*  URL:pace_max_seg */
23541 		case TCP_RACK_FORCE_MSEG:		/*  URL:force_max_seg */
23542 		case TCP_RACK_PACE_RATE_CA:		/*  URL:pr_ca */
23543 		case TCP_RACK_PACE_RATE_SS:		/*  URL:pr_ss*/
23544 		case TCP_RACK_PACE_RATE_REC:		/*  URL:pr_rec */
23545 		case TCP_RACK_GP_INCREASE_CA:		/*  URL:gp_inc_ca */
23546 		case TCP_RACK_GP_INCREASE_SS:		/*  URL:gp_inc_ss */
23547 		case TCP_RACK_GP_INCREASE_REC:		/*  URL:gp_inc_rec */
23548 		case TCP_RACK_RR_CONF:			/*  URL:rrr_conf */
23549 		case TCP_BBR_HDWR_PACE:			/*  URL:hdwrpace */
23550 		case TCP_HDWR_RATE_CAP:			/*  URL:hdwrcap boolean */
23551 		case TCP_PACING_RATE_CAP:		/*  URL:cap  -- used by side-channel */
23552 		case TCP_HDWR_UP_ONLY:			/*  URL:uponly -- hardware pacing  boolean */
23553 		case TCP_RACK_PACING_BETA:		/*  URL:pacing_beta */
23554 		case TCP_RACK_PACING_BETA_ECN:		/*  URL:pacing_beta_ecn */
23555 		case TCP_RACK_PACE_TO_FILL:		/*  URL:fillcw */
23556 		case TCP_RACK_DGP_IN_REC:		/*  URL:dgpinrec */
23557 			/* End pacing related */
23558 		case TCP_RXT_CLAMP:			/*  URL:rxtclamp */
23559 		case TCP_DELACK:			/*  URL:delack (in base TCP i.e. tcp_hints along with cc etc ) */
23560 		case TCP_RACK_PRR_SENDALOT:		/*  URL:prr_sendalot */
23561 		case TCP_RACK_MIN_TO:			/*  URL:min_to */
23562 		case TCP_RACK_EARLY_SEG:		/*  URL:early_seg */
23563 		case TCP_RACK_REORD_THRESH:		/*  URL:reord_thresh */
23564 		case TCP_RACK_REORD_FADE:		/*  URL:reord_fade */
23565 		case TCP_RACK_TLP_THRESH:		/*  URL:tlp_thresh */
23566 		case TCP_RACK_PKT_DELAY:		/*  URL:pkt_delay */
23567 		case TCP_RACK_TLP_USE:			/*  URL:tlp_use */
23568 		case TCP_BBR_RACK_RTT_USE:		/*  URL:rttuse */
23569 		case TCP_BBR_USE_RACK_RR:		/*  URL:rackrr */
23570 		case TCP_RACK_DO_DETECTION:		/*  URL:detect */
23571 		case TCP_NO_PRR:			/*  URL:noprr */
23572 		case TCP_TIMELY_DYN_ADJ:      		/*  URL:dynamic */
23573 		case TCP_DATA_AFTER_CLOSE:		/*  no URL */
23574 		case TCP_RACK_NONRXT_CFG_RATE:		/*  URL:nonrxtcr */
23575 		case TCP_SHARED_CWND_ENABLE:		/*  URL:scwnd */
23576 		case TCP_RACK_MBUF_QUEUE:		/*  URL:mqueue */
23577 		case TCP_RACK_NO_PUSH_AT_MAX:		/*  URL:npush */
23578 		case TCP_SHARED_CWND_TIME_LIMIT:	/*  URL:lscwnd */
23579 		case TCP_RACK_PROFILE:			/*  URL:profile */
23580 		case TCP_HYBRID_PACING:			/*  URL:hybrid */
23581 		case TCP_USE_CMP_ACKS:			/*  URL:cmpack */
23582 		case TCP_RACK_ABC_VAL:			/*  URL:labc */
23583 		case TCP_REC_ABC_VAL:			/*  URL:reclabc */
23584 		case TCP_RACK_MEASURE_CNT:		/*  URL:measurecnt */
23585 		case TCP_DEFER_OPTIONS:			/*  URL:defer */
23586 		case TCP_RACK_DSACK_OPT:		/*  URL:dsack */
23587 		case TCP_RACK_TIMER_SLOP:		/*  URL:timer_slop */
23588 		case TCP_RACK_ENABLE_HYSTART:		/*  URL:hystart */
23589 		case TCP_RACK_SET_RXT_OPTIONS:		/*  URL:rxtsz */
23590 		case TCP_RACK_HI_BETA:			/*  URL:hibeta */
23591 		case TCP_RACK_SPLIT_LIMIT:		/*  URL:split */
23592 		case TCP_RACK_PACING_DIVISOR:		/*  URL:divisor */
23593 		case TCP_PACING_DND:			/*  URL:dnd */
23594 			goto process_opt;
23595 			break;
23596 		default:
23597 			/* Filter off all unknown options to the base stack */
23598 			return (tcp_default_ctloutput(tp, sopt));
23599 			break;
23600 		}
23601 
23602 	default:
23603 		INP_WUNLOCK(inp);
23604 		return (0);
23605 	}
23606 process_opt:
23607 	INP_WUNLOCK(inp);
23608 	if (sopt->sopt_name == TCP_PACING_RATE_CAP) {
23609 		error = sooptcopyin(sopt, &loptval, sizeof(loptval), sizeof(loptval));
23610 		/*
23611 		 * We truncate it down to 32 bits for the socket-option trace this
23612 		 * means rates > 34Gbps won't show right, but thats probably ok.
23613 		 */
23614 		optval = (uint32_t)loptval;
23615 	} else if (sopt->sopt_name == TCP_HYBRID_PACING) {
23616 		error = sooptcopyin(sopt, &hybrid, sizeof(hybrid), sizeof(hybrid));
23617 	} else {
23618 		error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval));
23619 		/* Save it in 64 bit form too */
23620 		loptval = optval;
23621 	}
23622 	if (error)
23623 		return (error);
23624 	INP_WLOCK(inp);
23625 	if (tp->t_fb != &__tcp_rack) {
23626 		INP_WUNLOCK(inp);
23627 		return (ENOPROTOOPT);
23628 	}
23629 	if (rack->defer_options && (rack->gp_ready == 0) &&
23630 	    (sopt->sopt_name != TCP_DEFER_OPTIONS) &&
23631 	    (sopt->sopt_name != TCP_HYBRID_PACING) &&
23632 	    (sopt->sopt_name != TCP_RACK_PACING_BETA) &&
23633 	    (sopt->sopt_name != TCP_RACK_SET_RXT_OPTIONS) &&
23634 	    (sopt->sopt_name != TCP_RACK_PACING_BETA_ECN) &&
23635 	    (sopt->sopt_name != TCP_RACK_MEASURE_CNT)) {
23636 		/* Options are beind deferred */
23637 		if (rack_add_deferred_option(rack, sopt->sopt_name, loptval)) {
23638 			INP_WUNLOCK(inp);
23639 			return (0);
23640 		} else {
23641 			/* No memory to defer, fail */
23642 			INP_WUNLOCK(inp);
23643 			return (ENOMEM);
23644 		}
23645 	}
23646 	error = rack_process_option(tp, rack, sopt->sopt_name, optval, loptval, &hybrid);
23647 	INP_WUNLOCK(inp);
23648 	return (error);
23649 }
23650 
23651 static void
23652 rack_fill_info(struct tcpcb *tp, struct tcp_info *ti)
23653 {
23654 
23655 	INP_WLOCK_ASSERT(tptoinpcb(tp));
23656 	bzero(ti, sizeof(*ti));
23657 
23658 	ti->tcpi_state = tp->t_state;
23659 	if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
23660 		ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
23661 	if (tp->t_flags & TF_SACK_PERMIT)
23662 		ti->tcpi_options |= TCPI_OPT_SACK;
23663 	if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
23664 		ti->tcpi_options |= TCPI_OPT_WSCALE;
23665 		ti->tcpi_snd_wscale = tp->snd_scale;
23666 		ti->tcpi_rcv_wscale = tp->rcv_scale;
23667 	}
23668 	if (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))
23669 		ti->tcpi_options |= TCPI_OPT_ECN;
23670 	if (tp->t_flags & TF_FASTOPEN)
23671 		ti->tcpi_options |= TCPI_OPT_TFO;
23672 	/* still kept in ticks is t_rcvtime */
23673 	ti->tcpi_last_data_recv = ((uint32_t)ticks - tp->t_rcvtime) * tick;
23674 	/* Since we hold everything in precise useconds this is easy */
23675 	ti->tcpi_rtt = tp->t_srtt;
23676 	ti->tcpi_rttvar = tp->t_rttvar;
23677 	ti->tcpi_rto = tp->t_rxtcur;
23678 	ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
23679 	ti->tcpi_snd_cwnd = tp->snd_cwnd;
23680 	/*
23681 	 * FreeBSD-specific extension fields for tcp_info.
23682 	 */
23683 	ti->tcpi_rcv_space = tp->rcv_wnd;
23684 	ti->tcpi_rcv_nxt = tp->rcv_nxt;
23685 	ti->tcpi_snd_wnd = tp->snd_wnd;
23686 	ti->tcpi_snd_bwnd = 0;		/* Unused, kept for compat. */
23687 	ti->tcpi_snd_nxt = tp->snd_nxt;
23688 	ti->tcpi_snd_mss = tp->t_maxseg;
23689 	ti->tcpi_rcv_mss = tp->t_maxseg;
23690 	ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;
23691 	ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
23692 	ti->tcpi_snd_zerowin = tp->t_sndzerowin;
23693 	ti->tcpi_total_tlp = tp->t_sndtlppack;
23694 	ti->tcpi_total_tlp_bytes = tp->t_sndtlpbyte;
23695 #ifdef NETFLIX_STATS
23696 	memcpy(&ti->tcpi_rxsyninfo, &tp->t_rxsyninfo, sizeof(struct tcpsyninfo));
23697 #endif
23698 #ifdef TCP_OFFLOAD
23699 	if (tp->t_flags & TF_TOE) {
23700 		ti->tcpi_options |= TCPI_OPT_TOE;
23701 		tcp_offload_tcp_info(tp, ti);
23702 	}
23703 #endif
23704 }
23705 
23706 static int
23707 rack_get_sockopt(struct tcpcb *tp, struct sockopt *sopt)
23708 {
23709 	struct inpcb *inp = tptoinpcb(tp);
23710 	struct tcp_rack *rack;
23711 	int32_t error, optval;
23712 	uint64_t val, loptval;
23713 	struct	tcp_info ti;
23714 	/*
23715 	 * Because all our options are either boolean or an int, we can just
23716 	 * pull everything into optval and then unlock and copy. If we ever
23717 	 * add a option that is not a int, then this will have quite an
23718 	 * impact to this routine.
23719 	 */
23720 	error = 0;
23721 	rack = (struct tcp_rack *)tp->t_fb_ptr;
23722 	if (rack == NULL) {
23723 		INP_WUNLOCK(inp);
23724 		return (EINVAL);
23725 	}
23726 	switch (sopt->sopt_name) {
23727 	case TCP_INFO:
23728 		/* First get the info filled */
23729 		rack_fill_info(tp, &ti);
23730 		/* Fix up the rtt related fields if needed */
23731 		INP_WUNLOCK(inp);
23732 		error = sooptcopyout(sopt, &ti, sizeof ti);
23733 		return (error);
23734 	/*
23735 	 * Beta is the congestion control value for NewReno that influences how
23736 	 * much of a backoff happens when loss is detected. It is normally set
23737 	 * to 50 for 50% i.e. the cwnd is reduced to 50% of its previous value
23738 	 * when you exit recovery.
23739 	 */
23740 	case TCP_RACK_PACING_BETA:
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;
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;
23753 			else
23754 				error = EINVAL;
23755 		}
23756 		break;
23757 		/*
23758 		 * Beta_ecn is the congestion control value for NewReno that influences how
23759 		 * much of a backoff happens when a ECN mark is detected. It is normally set
23760 		 * to 80 for 80% i.e. the cwnd is reduced by 20% of its previous value when
23761 		 * you exit recovery. Note that classic ECN has a beta of 50, it is only
23762 		 * ABE Ecn that uses this "less" value, but we do too with pacing :)
23763 		 */
23764 
23765 	case TCP_RACK_PACING_BETA_ECN:
23766 		if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0)
23767 			error = EINVAL;
23768 		else if (rack->rc_pacing_cc_set == 0)
23769 			optval = rack->r_ctl.rc_saved_beta.beta_ecn;
23770 		else {
23771 			/*
23772 			 * Reach out into the CC data and report back what
23773 			 * I have previously set. Yeah it looks hackish but
23774 			 * we don't want to report the saved values.
23775 			 */
23776 			if (tp->t_ccv.cc_data)
23777 				optval = ((struct newreno *)tp->t_ccv.cc_data)->beta_ecn;
23778 			else
23779 				error = EINVAL;
23780 		}
23781 		break;
23782 	case TCP_RACK_DSACK_OPT:
23783 		optval = 0;
23784 		if (rack->rc_rack_tmr_std_based) {
23785 			optval |= 1;
23786 		}
23787 		if (rack->rc_rack_use_dsack) {
23788 			optval |= 2;
23789 		}
23790 		break;
23791  	case TCP_RACK_ENABLE_HYSTART:
23792 	{
23793 		if (tp->t_ccv.flags & CCF_HYSTART_ALLOWED) {
23794 			optval = RACK_HYSTART_ON;
23795 			if (tp->t_ccv.flags & CCF_HYSTART_CAN_SH_CWND)
23796 				optval = RACK_HYSTART_ON_W_SC;
23797 			if (tp->t_ccv.flags & CCF_HYSTART_CONS_SSTH)
23798 				optval = RACK_HYSTART_ON_W_SC_C;
23799 		} else {
23800 			optval = RACK_HYSTART_OFF;
23801 		}
23802 	}
23803 	break;
23804 	case TCP_RACK_DGP_IN_REC:
23805 		optval = rack->r_ctl.full_dgp_in_rec;
23806 		break;
23807 	case TCP_RACK_HI_BETA:
23808 		optval = rack->rack_hibeta;
23809 		break;
23810 	case TCP_RXT_CLAMP:
23811 		optval = rack->r_ctl.saved_rxt_clamp_val;
23812 		break;
23813 	case TCP_DEFER_OPTIONS:
23814 		optval = rack->defer_options;
23815 		break;
23816 	case TCP_RACK_MEASURE_CNT:
23817 		optval = rack->r_ctl.req_measurements;
23818 		break;
23819 	case TCP_REC_ABC_VAL:
23820 		optval = rack->r_use_labc_for_rec;
23821 		break;
23822 	case TCP_RACK_ABC_VAL:
23823 		optval = rack->rc_labc;
23824 		break;
23825 	case TCP_HDWR_UP_ONLY:
23826 		optval= rack->r_up_only;
23827 		break;
23828 	case TCP_PACING_RATE_CAP:
23829 		loptval = rack->r_ctl.bw_rate_cap;
23830 		break;
23831 	case TCP_RACK_PROFILE:
23832 		/* You cannot retrieve a profile, its write only */
23833 		error = EINVAL;
23834 		break;
23835 	case TCP_HYBRID_PACING:
23836 		/* You cannot retrieve hybrid pacing information, its write only */
23837 		error = EINVAL;
23838 		break;
23839 	case TCP_USE_CMP_ACKS:
23840 		optval = rack->r_use_cmp_ack;
23841 		break;
23842 	case TCP_RACK_PACE_TO_FILL:
23843 		optval = rack->rc_pace_to_cwnd;
23844 		if (optval && rack->r_fill_less_agg)
23845 			optval++;
23846 		break;
23847 	case TCP_RACK_NO_PUSH_AT_MAX:
23848 		optval = rack->r_ctl.rc_no_push_at_mrtt;
23849 		break;
23850 	case TCP_SHARED_CWND_ENABLE:
23851 		optval = rack->rack_enable_scwnd;
23852 		break;
23853 	case TCP_RACK_NONRXT_CFG_RATE:
23854 		optval = rack->rack_rec_nonrxt_use_cr;
23855 		break;
23856 	case TCP_NO_PRR:
23857 		if (rack->rack_no_prr  == 1)
23858 			optval = 1;
23859 		else if (rack->no_prr_addback == 1)
23860 			optval = 2;
23861 		else
23862 			optval = 0;
23863 		break;
23864 	case TCP_RACK_DO_DETECTION:
23865 		optval = rack->do_detection;
23866 		break;
23867 	case TCP_RACK_MBUF_QUEUE:
23868 		/* Now do we use the LRO mbuf-queue feature */
23869 		optval = rack->r_mbuf_queue;
23870 		break;
23871 	case TCP_TIMELY_DYN_ADJ:
23872 		optval = rack->rc_gp_dyn_mul;
23873 		break;
23874 	case TCP_BBR_IWINTSO:
23875 		optval = rack->rc_init_win;
23876 		break;
23877 	case TCP_RACK_TLP_REDUCE:
23878 		/* RACK TLP cwnd reduction (bool) */
23879 		optval = rack->r_ctl.rc_tlp_cwnd_reduce;
23880 		break;
23881 	case TCP_BBR_RACK_INIT_RATE:
23882 		val = rack->r_ctl.init_rate;
23883 		/* convert to kbits per sec */
23884 		val *= 8;
23885 		val /= 1000;
23886 		optval = (uint32_t)val;
23887 		break;
23888 	case TCP_RACK_FORCE_MSEG:
23889 		optval = rack->rc_force_max_seg;
23890 		break;
23891 	case TCP_RACK_PACE_MIN_SEG:
23892 		optval = rack->r_ctl.rc_user_set_min_segs;
23893 		break;
23894 	case TCP_RACK_PACE_MAX_SEG:
23895 		/* Max segments in a pace */
23896 		optval = rack->rc_user_set_max_segs;
23897 		break;
23898 	case TCP_RACK_PACE_ALWAYS:
23899 		/* Use the always pace method */
23900 		optval = rack->rc_always_pace;
23901 		break;
23902 	case TCP_RACK_PRR_SENDALOT:
23903 		/* Allow PRR to send more than one seg */
23904 		optval = rack->r_ctl.rc_prr_sendalot;
23905 		break;
23906 	case TCP_RACK_MIN_TO:
23907 		/* Minimum time between rack t-o's in ms */
23908 		optval = rack->r_ctl.rc_min_to;
23909 		break;
23910 	case TCP_RACK_SPLIT_LIMIT:
23911 		optval = rack->r_ctl.rc_split_limit;
23912 		break;
23913 	case TCP_RACK_EARLY_SEG:
23914 		/* If early recovery max segments */
23915 		optval = rack->r_ctl.rc_early_recovery_segs;
23916 		break;
23917 	case TCP_RACK_REORD_THRESH:
23918 		/* RACK reorder threshold (shift amount) */
23919 		optval = rack->r_ctl.rc_reorder_shift;
23920 		break;
23921 	case TCP_RACK_REORD_FADE:
23922 		/* Does reordering fade after ms time */
23923 		optval = rack->r_ctl.rc_reorder_fade;
23924 		break;
23925 	case TCP_BBR_USE_RACK_RR:
23926 		/* Do we use the rack cheat for rxt */
23927 		optval = rack->use_rack_rr;
23928 		break;
23929 	case TCP_RACK_RR_CONF:
23930 		optval = rack->r_rr_config;
23931 		break;
23932 	case TCP_HDWR_RATE_CAP:
23933 		optval = rack->r_rack_hw_rate_caps;
23934 		break;
23935 	case TCP_BBR_HDWR_PACE:
23936 		optval = rack->rack_hdw_pace_ena;
23937 		break;
23938 	case TCP_RACK_TLP_THRESH:
23939 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
23940 		optval = rack->r_ctl.rc_tlp_threshold;
23941 		break;
23942 	case TCP_RACK_PKT_DELAY:
23943 		/* RACK added ms i.e. rack-rtt + reord + N */
23944 		optval = rack->r_ctl.rc_pkt_delay;
23945 		break;
23946 	case TCP_RACK_TLP_USE:
23947 		optval = rack->rack_tlp_threshold_use;
23948 		break;
23949 	case TCP_PACING_DND:
23950 		optval = rack->rc_pace_dnd;
23951 		break;
23952 	case TCP_RACK_PACE_RATE_CA:
23953 		optval = rack->r_ctl.rc_fixed_pacing_rate_ca;
23954 		break;
23955 	case TCP_RACK_PACE_RATE_SS:
23956 		optval = rack->r_ctl.rc_fixed_pacing_rate_ss;
23957 		break;
23958 	case TCP_RACK_PACE_RATE_REC:
23959 		optval = rack->r_ctl.rc_fixed_pacing_rate_rec;
23960 		break;
23961 	case TCP_RACK_GP_INCREASE_SS:
23962 		optval = rack->r_ctl.rack_per_of_gp_ca;
23963 		break;
23964 	case TCP_RACK_GP_INCREASE_CA:
23965 		optval = rack->r_ctl.rack_per_of_gp_ss;
23966 		break;
23967 	case TCP_RACK_PACING_DIVISOR:
23968 		optval = rack->r_ctl.pace_len_divisor;
23969 		break;
23970 	case TCP_BBR_RACK_RTT_USE:
23971 		optval = rack->r_ctl.rc_rate_sample_method;
23972 		break;
23973 	case TCP_DELACK:
23974 		optval = tp->t_delayed_ack;
23975 		break;
23976 	case TCP_DATA_AFTER_CLOSE:
23977 		optval = rack->rc_allow_data_af_clo;
23978 		break;
23979 	case TCP_SHARED_CWND_TIME_LIMIT:
23980 		optval = rack->r_limit_scw;
23981 		break;
23982 	case TCP_RACK_TIMER_SLOP:
23983 		optval = rack->r_ctl.timer_slop;
23984 		break;
23985 	default:
23986 		return (tcp_default_ctloutput(tp, sopt));
23987 		break;
23988 	}
23989 	INP_WUNLOCK(inp);
23990 	if (error == 0) {
23991 		if (TCP_PACING_RATE_CAP)
23992 			error = sooptcopyout(sopt, &loptval, sizeof loptval);
23993 		else
23994 			error = sooptcopyout(sopt, &optval, sizeof optval);
23995 	}
23996 	return (error);
23997 }
23998 
23999 static int
24000 rack_ctloutput(struct tcpcb *tp, struct sockopt *sopt)
24001 {
24002 	if (sopt->sopt_dir == SOPT_SET) {
24003 		return (rack_set_sockopt(tp, sopt));
24004 	} else if (sopt->sopt_dir == SOPT_GET) {
24005 		return (rack_get_sockopt(tp, sopt));
24006 	} else {
24007 		panic("%s: sopt_dir $%d", __func__, sopt->sopt_dir);
24008 	}
24009 }
24010 
24011 static const char *rack_stack_names[] = {
24012 	__XSTRING(STACKNAME),
24013 #ifdef STACKALIAS
24014 	__XSTRING(STACKALIAS),
24015 #endif
24016 };
24017 
24018 static int
24019 rack_ctor(void *mem, int32_t size, void *arg, int32_t how)
24020 {
24021 	memset(mem, 0, size);
24022 	return (0);
24023 }
24024 
24025 static void
24026 rack_dtor(void *mem, int32_t size, void *arg)
24027 {
24028 
24029 }
24030 
24031 static bool rack_mod_inited = false;
24032 
24033 static int
24034 tcp_addrack(module_t mod, int32_t type, void *data)
24035 {
24036 	int32_t err = 0;
24037 	int num_stacks;
24038 
24039 	switch (type) {
24040 	case MOD_LOAD:
24041 		rack_zone = uma_zcreate(__XSTRING(MODNAME) "_map",
24042 		    sizeof(struct rack_sendmap),
24043 		    rack_ctor, rack_dtor, NULL, NULL, UMA_ALIGN_PTR, 0);
24044 
24045 		rack_pcb_zone = uma_zcreate(__XSTRING(MODNAME) "_pcb",
24046 		    sizeof(struct tcp_rack),
24047 		    rack_ctor, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
24048 
24049 		sysctl_ctx_init(&rack_sysctl_ctx);
24050 		rack_sysctl_root = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
24051 		    SYSCTL_STATIC_CHILDREN(_net_inet_tcp),
24052 		    OID_AUTO,
24053 #ifdef STACKALIAS
24054 		    __XSTRING(STACKALIAS),
24055 #else
24056 		    __XSTRING(STACKNAME),
24057 #endif
24058 		    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
24059 		    "");
24060 		if (rack_sysctl_root == NULL) {
24061 			printf("Failed to add sysctl node\n");
24062 			err = EFAULT;
24063 			goto free_uma;
24064 		}
24065 		rack_init_sysctls();
24066 		num_stacks = nitems(rack_stack_names);
24067 		err = register_tcp_functions_as_names(&__tcp_rack, M_WAITOK,
24068 		    rack_stack_names, &num_stacks);
24069 		if (err) {
24070 			printf("Failed to register %s stack name for "
24071 			    "%s module\n", rack_stack_names[num_stacks],
24072 			    __XSTRING(MODNAME));
24073 			sysctl_ctx_free(&rack_sysctl_ctx);
24074 free_uma:
24075 			uma_zdestroy(rack_zone);
24076 			uma_zdestroy(rack_pcb_zone);
24077 			rack_counter_destroy();
24078 			printf("Failed to register rack module -- err:%d\n", err);
24079 			return (err);
24080 		}
24081 		tcp_lro_reg_mbufq();
24082 		rack_mod_inited = true;
24083 		break;
24084 	case MOD_QUIESCE:
24085 		err = deregister_tcp_functions(&__tcp_rack, true, false);
24086 		break;
24087 	case MOD_UNLOAD:
24088 		err = deregister_tcp_functions(&__tcp_rack, false, true);
24089 		if (err == EBUSY)
24090 			break;
24091 		if (rack_mod_inited) {
24092 			uma_zdestroy(rack_zone);
24093 			uma_zdestroy(rack_pcb_zone);
24094 			sysctl_ctx_free(&rack_sysctl_ctx);
24095 			rack_counter_destroy();
24096 			rack_mod_inited = false;
24097 		}
24098 		tcp_lro_dereg_mbufq();
24099 		err = 0;
24100 		break;
24101 	default:
24102 		return (EOPNOTSUPP);
24103 	}
24104 	return (err);
24105 }
24106 
24107 static moduledata_t tcp_rack = {
24108 	.name = __XSTRING(MODNAME),
24109 	.evhand = tcp_addrack,
24110 	.priv = 0
24111 };
24112 
24113 MODULE_VERSION(MODNAME, 1);
24114 DECLARE_MODULE(MODNAME, tcp_rack, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
24115 MODULE_DEPEND(MODNAME, tcphpts, 1, 1, 1);
24116 
24117 #endif /* #if !defined(INET) && !defined(INET6) */
24118