xref: /freebsd/sys/netinet/tcp_stacks/bbr.c (revision dd21556857e8d40f66bf5ad54754d9d52669ebf7)
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  * Author: Randall Stewart <rrs@netflix.com>
28  * This work is based on the ACM Queue paper
29  * BBR - Congestion Based Congestion Control
30  * and also numerous discussions with Neal, Yuchung and Van.
31  */
32 
33 #include <sys/cdefs.h>
34 #include "opt_inet.h"
35 #include "opt_inet6.h"
36 #include "opt_ipsec.h"
37 #include "opt_ratelimit.h"
38 #include <sys/param.h>
39 #include <sys/arb.h>
40 #include <sys/module.h>
41 #include <sys/kernel.h>
42 #include <sys/libkern.h>
43 #ifdef TCP_HHOOK
44 #include <sys/hhook.h>
45 #endif
46 #include <sys/malloc.h>
47 #include <sys/mbuf.h>
48 #include <sys/proc.h>
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 #endif
58 #include <sys/refcount.h>
59 #include <sys/queue.h>
60 #include <sys/eventhandler.h>
61 #include <sys/smp.h>
62 #include <sys/kthread.h>
63 #include <sys/lock.h>
64 #include <sys/mutex.h>
65 #include <sys/tim_filter.h>
66 #include <sys/time.h>
67 #include <sys/protosw.h>
68 #include <vm/uma.h>
69 #include <sys/kern_prefetch.h>
70 
71 #include <net/route.h>
72 #include <net/route/nhop.h>
73 #include <net/vnet.h>
74 
75 #define TCPSTATES		/* for logging */
76 
77 #include <netinet/in.h>
78 #include <netinet/in_kdtrace.h>
79 #include <netinet/in_pcb.h>
80 #include <netinet/ip.h>
81 #include <netinet/ip_icmp.h>	/* required for icmp_var.h */
82 #include <netinet/icmp_var.h>	/* for ICMP_BANDLIM */
83 #include <netinet/ip_var.h>
84 #include <netinet/ip6.h>
85 #include <netinet6/in6_pcb.h>
86 #include <netinet6/ip6_var.h>
87 #define	TCPOUTFLAGS
88 #include <netinet/tcp.h>
89 #include <netinet/tcp_fsm.h>
90 #include <netinet/tcp_seq.h>
91 #include <netinet/tcp_timer.h>
92 #include <netinet/tcp_var.h>
93 #include <netinet/tcpip.h>
94 #include <netinet/tcp_hpts.h>
95 #include <netinet/cc/cc.h>
96 #include <netinet/tcp_log_buf.h>
97 #include <netinet/tcp_ratelimit.h>
98 #include <netinet/tcp_lro.h>
99 #ifdef TCP_OFFLOAD
100 #include <netinet/tcp_offload.h>
101 #endif
102 #ifdef INET6
103 #include <netinet6/tcp6_var.h>
104 #endif
105 #include <netinet/tcp_fastopen.h>
106 
107 #include <netipsec/ipsec_support.h>
108 #include <net/if.h>
109 #include <net/if_var.h>
110 #include <net/ethernet.h>
111 
112 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
113 #include <netipsec/ipsec.h>
114 #include <netipsec/ipsec6.h>
115 #endif				/* IPSEC */
116 
117 #include <netinet/udp.h>
118 #include <netinet/udp_var.h>
119 #include <machine/in_cksum.h>
120 
121 #ifdef MAC
122 #include <security/mac/mac_framework.h>
123 #endif
124 
125 #include "sack_filter.h"
126 #include "tcp_bbr.h"
127 #include "rack_bbr_common.h"
128 uma_zone_t bbr_zone;
129 uma_zone_t bbr_pcb_zone;
130 
131 struct sysctl_ctx_list bbr_sysctl_ctx;
132 struct sysctl_oid *bbr_sysctl_root;
133 
134 #define	TCPT_RANGESET_NOSLOP(tv, value, tvmin, tvmax) do { \
135 	(tv) = (value); \
136 	if ((u_long)(tv) < (u_long)(tvmin)) \
137 		(tv) = (tvmin); \
138 	if ((u_long)(tv) > (u_long)(tvmax)) \
139 		(tv) = (tvmax); \
140 } while(0)
141 
142 /*#define BBR_INVARIANT 1*/
143 
144 /*
145  * initial window
146  */
147 static uint32_t bbr_def_init_win = 10;
148 static int32_t bbr_persist_min = 250000;	/* 250ms */
149 static int32_t bbr_persist_max = 1000000;	/* 1 Second */
150 static int32_t bbr_cwnd_may_shrink = 0;
151 static int32_t bbr_cwndtarget_rtt_touse = BBR_RTT_PROP;
152 static int32_t bbr_num_pktepo_for_del_limit = BBR_NUM_RTTS_FOR_DEL_LIMIT;
153 static int32_t bbr_hardware_pacing_limit = 8000;
154 static int32_t bbr_quanta = 3;	/* How much extra quanta do we get? */
155 static int32_t bbr_no_retran = 0;
156 
157 static int32_t bbr_error_base_paceout = 10000; /* usec to pace */
158 static int32_t bbr_max_net_error_cnt = 10;
159 /* Should the following be dynamic too -- loss wise */
160 static int32_t bbr_rtt_gain_thresh = 0;
161 /* Measurement controls */
162 static int32_t bbr_use_google_algo = 1;
163 static int32_t bbr_ts_limiting = 1;
164 static int32_t bbr_ts_can_raise = 0;
165 static int32_t bbr_do_red = 600;
166 static int32_t bbr_red_scale = 20000;
167 static int32_t bbr_red_mul = 1;
168 static int32_t bbr_red_div = 2;
169 static int32_t bbr_red_growth_restrict = 1;
170 static int32_t  bbr_target_is_bbunit = 0;
171 static int32_t bbr_drop_limit = 0;
172 /*
173  * How much gain do we need to see to
174  * stay in startup?
175  */
176 static int32_t bbr_marks_rxt_sack_passed = 0;
177 static int32_t bbr_start_exit = 25;
178 static int32_t bbr_low_start_exit = 25;	/* When we are in reduced gain */
179 static int32_t bbr_startup_loss_thresh = 2000;	/* 20.00% loss */
180 static int32_t bbr_hptsi_max_mul = 1;	/* These two mul/div assure a min pacing */
181 static int32_t bbr_hptsi_max_div = 2;	/* time, 0 means turned off. We need this
182 					 * if we go back ever to where the pacer
183 					 * has priority over timers.
184 					 */
185 static int32_t bbr_policer_call_from_rack_to = 0;
186 static int32_t bbr_policer_detection_enabled = 1;
187 static int32_t bbr_min_measurements_req = 1;	/* We need at least 2
188 						 * measurements before we are
189 						 * "good" note that 2 == 1.
190 						 * This is because we use a >
191 						 * comparison. This means if
192 						 * min_measure was 0, it takes
193 						 * num-measures > min(0) and
194 						 * you get 1 measurement and
195 						 * you are good. Set to 1, you
196 						 * have to have two
197 						 * measurements (this is done
198 						 * to prevent it from being ok
199 						 * to have no measurements). */
200 static int32_t bbr_no_pacing_until = 4;
201 
202 static int32_t bbr_min_usec_delta = 20000;	/* 20,000 usecs */
203 static int32_t bbr_min_peer_delta = 20;		/* 20 units */
204 static int32_t bbr_delta_percent = 150;		/* 15.0 % */
205 
206 static int32_t bbr_target_cwnd_mult_limit = 8;
207 /*
208  * bbr_cwnd_min_val is the number of
209  * segments we hold to in the RTT probe
210  * state typically 4.
211  */
212 static int32_t bbr_cwnd_min_val = BBR_PROBERTT_NUM_MSS;
213 
214 static int32_t bbr_cwnd_min_val_hs = BBR_HIGHSPEED_NUM_MSS;
215 
216 static int32_t bbr_gain_to_target = 1;
217 static int32_t bbr_gain_gets_extra_too = 1;
218 /*
219  * bbr_high_gain is the 2/ln(2) value we need
220  * to double the sending rate in startup. This
221  * is used for both cwnd and hptsi gain's.
222  */
223 static int32_t bbr_high_gain = BBR_UNIT * 2885 / 1000 + 1;
224 static int32_t bbr_startup_lower = BBR_UNIT * 1500 / 1000 + 1;
225 static int32_t bbr_use_lower_gain_in_startup = 1;
226 
227 /* thresholds for reduction on drain in sub-states/drain */
228 static int32_t bbr_drain_rtt = BBR_SRTT;
229 static int32_t bbr_drain_floor = 88;
230 static int32_t google_allow_early_out = 1;
231 static int32_t google_consider_lost = 1;
232 static int32_t bbr_drain_drop_mul = 4;
233 static int32_t bbr_drain_drop_div = 5;
234 static int32_t bbr_rand_ot = 50;
235 static int32_t bbr_can_force_probertt = 0;
236 static int32_t bbr_can_adjust_probertt = 1;
237 static int32_t bbr_probertt_sets_rtt = 0;
238 static int32_t bbr_can_use_ts_for_rtt = 1;
239 static int32_t bbr_is_ratio = 0;
240 static int32_t bbr_sub_drain_app_limit = 1;
241 static int32_t bbr_prtt_slam_cwnd = 1;
242 static int32_t bbr_sub_drain_slam_cwnd = 1;
243 static int32_t bbr_slam_cwnd_in_main_drain = 1;
244 static int32_t bbr_filter_len_sec = 6;	/* How long does the rttProp filter
245 					 * hold */
246 static uint32_t bbr_rtt_probe_limit = (USECS_IN_SECOND * 4);
247 /*
248  * bbr_drain_gain is the reverse of the high_gain
249  * designed to drain back out the standing queue
250  * that is formed in startup by causing a larger
251  * hptsi gain and thus drainging the packets
252  * in flight.
253  */
254 static int32_t bbr_drain_gain = BBR_UNIT * 1000 / 2885;
255 static int32_t bbr_rttprobe_gain = 192;
256 
257 /*
258  * The cwnd_gain is the default cwnd gain applied when
259  * calculating a target cwnd. Note that the cwnd is
260  * a secondary factor in the way BBR works (see the
261  * paper and think about it, it will take some time).
262  * Basically the hptsi_gain spreads the packets out
263  * so you never get more than BDP to the peer even
264  * if the cwnd is high. In our implemenation that
265  * means in non-recovery/retransmission scenarios
266  * cwnd will never be reached by the flight-size.
267  */
268 static int32_t bbr_cwnd_gain = BBR_UNIT * 2;
269 static int32_t bbr_tlp_type_to_use = BBR_SRTT;
270 static int32_t bbr_delack_time = 100000;	/* 100ms in useconds */
271 static int32_t bbr_sack_not_required = 0;	/* set to one to allow non-sack to use bbr */
272 static int32_t bbr_initial_bw_bps = 62500;	/* 500kbps in bytes ps */
273 static int32_t bbr_ignore_data_after_close = 1;
274 static int16_t bbr_hptsi_gain[] = {
275 	(BBR_UNIT *5 / 4),
276 	(BBR_UNIT * 3 / 4),
277 	BBR_UNIT,
278 	BBR_UNIT,
279 	BBR_UNIT,
280 	BBR_UNIT,
281 	BBR_UNIT,
282 	BBR_UNIT
283 };
284 int32_t bbr_use_rack_resend_cheat = 1;
285 int32_t bbr_sends_full_iwnd = 1;
286 
287 #define BBR_HPTSI_GAIN_MAX 8
288 /*
289  * The BBR module incorporates a number of
290  * TCP ideas that have been put out into the IETF
291  * over the last few years:
292  * - Yuchung Cheng's RACK TCP (for which its named) that
293  *    will stop us using the number of dup acks and instead
294  *    use time as the gage of when we retransmit.
295  * - Reorder Detection of RFC4737 and the Tail-Loss probe draft
296  *    of Dukkipati et.al.
297  * - Van Jacobson's et.al BBR.
298  *
299  * RACK depends on SACK, so if an endpoint arrives that
300  * cannot do SACK the state machine below will shuttle the
301  * connection back to using the "default" TCP stack that is
302  * in FreeBSD.
303  *
304  * To implement BBR and RACK the original TCP stack was first decomposed
305  * into a functional state machine with individual states
306  * for each of the possible TCP connection states. The do_segment
307  * functions role in life is to mandate the connection supports SACK
308  * initially and then assure that the RACK state matches the conenction
309  * state before calling the states do_segment function. Data processing
310  * of inbound segments also now happens in the hpts_do_segment in general
311  * with only one exception. This is so we can keep the connection on
312  * a single CPU.
313  *
314  * Each state is simplified due to the fact that the original do_segment
315  * has been decomposed and we *know* what state we are in (no
316  * switches on the state) and all tests for SACK are gone. This
317  * greatly simplifies what each state does.
318  *
319  * TCP output is also over-written with a new version since it
320  * must maintain the new rack scoreboard and has had hptsi
321  * integrated as a requirment. Still todo is to eliminate the
322  * use of the callout_() system and use the hpts for all
323  * timers as well.
324  */
325 static uint32_t bbr_rtt_probe_time = 200000;	/* 200ms in micro seconds */
326 static uint32_t bbr_rtt_probe_cwndtarg = 4;	/* How many mss's outstanding */
327 static const int32_t bbr_min_req_free = 2;	/* The min we must have on the
328 						 * free list */
329 static int32_t bbr_tlp_thresh = 1;
330 static int32_t bbr_reorder_thresh = 2;
331 static int32_t bbr_reorder_fade = 60000000;	/* 0 - never fade, def
332 						 * 60,000,000 - 60 seconds */
333 static int32_t bbr_pkt_delay = 1000;
334 static int32_t bbr_min_to = 1000;	/* Number of usec's minimum timeout */
335 static int32_t bbr_incr_timers = 1;
336 
337 static int32_t bbr_tlp_min = 10000;	/* 10ms in usecs */
338 static int32_t bbr_delayed_ack_time = 200000;	/* 200ms in usecs */
339 static int32_t bbr_exit_startup_at_loss = 1;
340 
341 /*
342  * bbr_lt_bw_ratio is 1/8th
343  * bbr_lt_bw_diff is  < 4 Kbit/sec
344  */
345 static uint64_t bbr_lt_bw_diff = 4000 / 8;	/* In bytes per second */
346 static uint64_t bbr_lt_bw_ratio = 8;	/* For 1/8th */
347 static uint32_t bbr_lt_bw_max_rtts = 48;	/* How many rtt's do we use
348 						 * the lt_bw for */
349 static uint32_t bbr_lt_intvl_min_rtts = 4;	/* Min num of RTT's to measure
350 						 * lt_bw */
351 static int32_t bbr_lt_intvl_fp = 0;		/* False positive epoch diff */
352 static int32_t bbr_lt_loss_thresh = 196;	/* Lost vs delivered % */
353 static int32_t bbr_lt_fd_thresh = 100;		/* false detection % */
354 
355 static int32_t bbr_verbose_logging = 0;
356 /*
357  * Currently regular tcp has a rto_min of 30ms
358  * the backoff goes 12 times so that ends up
359  * being a total of 122.850 seconds before a
360  * connection is killed.
361  */
362 static int32_t bbr_rto_min_ms = 30;	/* 30ms same as main freebsd */
363 static int32_t bbr_rto_max_sec = 4;	/* 4 seconds */
364 
365 /****************************************************/
366 /* DEFAULT TSO SIZING  (cpu performance impacting)  */
367 /****************************************************/
368 /* What amount is our formula using to get TSO size */
369 static int32_t bbr_hptsi_per_second = 1000;
370 
371 /*
372  * For hptsi under bbr_cross_over connections what is delay
373  * target 7ms (in usec) combined with a seg_max of 2
374  * gets us close to identical google behavior in
375  * TSO size selection (possibly more 1MSS sends).
376  */
377 static int32_t bbr_hptsi_segments_delay_tar = 7000;
378 
379 /* Does pacing delay include overhead's in its time calculations? */
380 static int32_t bbr_include_enet_oh = 0;
381 static int32_t bbr_include_ip_oh = 1;
382 static int32_t bbr_include_tcp_oh = 1;
383 static int32_t bbr_google_discount = 10;
384 
385 /* Do we use (nf mode) pkt-epoch to drive us or rttProp? */
386 static int32_t bbr_state_is_pkt_epoch = 0;
387 static int32_t bbr_state_drain_2_tar = 1;
388 /* What is the max the 0 - bbr_cross_over MBPS TSO target
389  * can reach using our delay target. Note that this
390  * value becomes the floor for the cross over
391  * algorithm.
392  */
393 static int32_t bbr_hptsi_segments_max = 2;
394 static int32_t bbr_hptsi_segments_floor = 1;
395 static int32_t bbr_hptsi_utter_max = 0;
396 
397 /* What is the min the 0 - bbr_cross-over MBPS  TSO target can be */
398 static int32_t bbr_hptsi_bytes_min = 1460;
399 static int32_t bbr_all_get_min = 0;
400 
401 /* Cross over point from algo-a to algo-b */
402 static uint32_t bbr_cross_over = TWENTY_THREE_MBPS;
403 
404 /* Do we deal with our restart state? */
405 static int32_t bbr_uses_idle_restart = 0;
406 static int32_t bbr_idle_restart_threshold = 100000;	/* 100ms in useconds */
407 
408 /* Do we allow hardware pacing? */
409 static int32_t bbr_allow_hdwr_pacing = 0;
410 static int32_t bbr_hdwr_pace_adjust = 2;	/* multipler when we calc the tso size */
411 static int32_t bbr_hdwr_pace_floor = 1;
412 static int32_t bbr_hdwr_pacing_delay_cnt = 10;
413 
414 /****************************************************/
415 static int32_t bbr_resends_use_tso = 0;
416 static int32_t bbr_tlp_max_resend = 2;
417 static int32_t bbr_sack_block_limit = 128;
418 
419 #define  BBR_MAX_STAT 19
420 counter_u64_t bbr_state_time[BBR_MAX_STAT];
421 counter_u64_t bbr_state_lost[BBR_MAX_STAT];
422 counter_u64_t bbr_state_resend[BBR_MAX_STAT];
423 counter_u64_t bbr_stat_arry[BBR_STAT_SIZE];
424 counter_u64_t bbr_opts_arry[BBR_OPTS_SIZE];
425 counter_u64_t bbr_out_size[TCP_MSS_ACCT_SIZE];
426 counter_u64_t bbr_flows_whdwr_pacing;
427 counter_u64_t bbr_flows_nohdwr_pacing;
428 
429 counter_u64_t bbr_nohdwr_pacing_enobuf;
430 counter_u64_t bbr_hdwr_pacing_enobuf;
431 
432 static inline uint64_t bbr_get_bw(struct tcp_bbr *bbr);
433 
434 /*
435  * Static defintions we need for forward declarations.
436  */
437 static uint32_t
438 bbr_get_pacing_length(struct tcp_bbr *bbr, uint16_t gain,
439 		      uint32_t useconds_time, uint64_t bw);
440 static uint32_t
441 bbr_get_a_state_target(struct tcp_bbr *bbr, uint32_t gain);
442 static void
443 bbr_set_state(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t win);
444 static void
445 bbr_set_probebw_gains(struct tcp_bbr *bbr,  uint32_t cts, uint32_t losses);
446 static void
447 bbr_substate_change(struct tcp_bbr *bbr, uint32_t cts, int line,
448 		    int dolog);
449 static uint32_t
450 bbr_get_target_cwnd(struct tcp_bbr *bbr, uint64_t bw, uint32_t gain);
451 static void
452 bbr_state_change(struct tcp_bbr *bbr, uint32_t cts, int32_t epoch,
453 		 int32_t pkt_epoch, uint32_t losses);
454 static uint32_t
455 bbr_calc_thresh_rack(struct tcp_bbr *bbr, uint32_t srtt, uint32_t cts,
456 		     struct bbr_sendmap *rsm);
457 static uint32_t
458 bbr_initial_cwnd(struct tcp_bbr *bbr, struct tcpcb *tp);
459 static uint32_t
460 bbr_calc_thresh_tlp(struct tcpcb *tp, struct tcp_bbr *bbr,
461 		    struct bbr_sendmap *rsm, uint32_t srtt, uint32_t cts);
462 static void
463 bbr_exit_persist(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts,
464 		 int32_t line);
465 static void
466 bbr_set_state_target(struct tcp_bbr *bbr, int line);
467 static void
468 bbr_enter_probe_rtt(struct tcp_bbr *bbr, uint32_t cts, int32_t line);
469 static void
470 bbr_log_progress_event(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t tick,
471 		       int event, int line);
472 static void
473 tcp_bbr_tso_size_check(struct tcp_bbr *bbr, uint32_t cts);
474 static void
475 bbr_setup_red_bw(struct tcp_bbr *bbr, uint32_t cts);
476 static void
477 bbr_log_rtt_shrinks(struct tcp_bbr *bbr, uint32_t cts, uint32_t applied,
478 		    uint32_t rtt, uint32_t line, uint8_t is_start,
479 		    uint16_t set);
480 static struct bbr_sendmap *
481 bbr_find_lowest_rsm(struct tcp_bbr *bbr);
482 static __inline uint32_t
483 bbr_get_rtt(struct tcp_bbr *bbr, int32_t rtt_type);
484 static void
485 bbr_log_to_start(struct tcp_bbr *bbr, uint32_t cts, uint32_t to, int32_t slot,
486 		 uint8_t which);
487 static void
488 bbr_log_timer_var(struct tcp_bbr *bbr, int mode, uint32_t cts,
489 		  uint32_t time_since_sent, uint32_t srtt,
490 		  uint32_t thresh, uint32_t to);
491 static void
492 bbr_log_hpts_diag(struct tcp_bbr *bbr, uint32_t cts, struct hpts_diag *diag);
493 static void
494 bbr_log_type_bbrsnd(struct tcp_bbr *bbr, uint32_t len, uint32_t slot,
495 		    uint32_t del_by, uint32_t cts, uint32_t sloton,
496 		    uint32_t prev_delay);
497 static void
498 bbr_enter_persist(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts,
499 		  int32_t line);
500 static void
501 bbr_stop_all_timers(struct tcpcb *tp, struct tcp_bbr *bbr);
502 static void
503 bbr_exit_probe_rtt(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts);
504 static void
505 bbr_check_probe_rtt_limits(struct tcp_bbr *bbr, uint32_t cts);
506 static void
507 bbr_timer_cancel(struct tcp_bbr *bbr, int32_t line, uint32_t cts);
508 static void
509 bbr_log_pacing_delay_calc(struct tcp_bbr *bbr, uint16_t gain, uint32_t len,
510 			  uint32_t cts, uint32_t usecs, uint64_t bw,
511 			  uint32_t override, int mod);
512 static int bbr_ctloutput(struct tcpcb *tp, struct sockopt *sopt);
513 
514 static inline uint8_t
515 bbr_state_val(struct tcp_bbr *bbr)
516 {
517 	return(bbr->rc_bbr_substate);
518 }
519 
520 static inline uint32_t
521 get_min_cwnd(struct tcp_bbr *bbr)
522 {
523 	int mss;
524 
525 	mss = min((bbr->rc_tp->t_maxseg - bbr->rc_last_options),
526 		  bbr->r_ctl.rc_pace_max_segs);
527 	if (bbr_get_rtt(bbr, BBR_RTT_PROP) < BBR_HIGH_SPEED)
528 		return (bbr_cwnd_min_val_hs * mss);
529 	else
530 		return (bbr_cwnd_min_val * mss);
531 }
532 
533 static uint32_t
534 bbr_get_persists_timer_val(struct tcpcb *tp, struct tcp_bbr *bbr)
535 {
536 	uint64_t srtt, var;
537 	uint64_t ret_val;
538 
539 	bbr->r_ctl.rc_hpts_flags |= PACE_TMR_PERSIT;
540 	if (tp->t_srtt == 0) {
541 		srtt = (uint64_t)BBR_INITIAL_RTO;
542 		var = 0;
543 	} else {
544 		srtt = ((uint64_t)TICKS_2_USEC(tp->t_srtt) >> TCP_RTT_SHIFT);
545 		var = ((uint64_t)TICKS_2_USEC(tp->t_rttvar) >> TCP_RTT_SHIFT);
546 	}
547 	TCPT_RANGESET_NOSLOP(ret_val, ((srtt + var) * tcp_backoff[tp->t_rxtshift]),
548 	    bbr_persist_min, bbr_persist_max);
549 	return ((uint32_t)ret_val);
550 }
551 
552 static uint32_t
553 bbr_timer_start(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
554 {
555 	/*
556 	 * Start the FR timer, we do this based on getting the first one in
557 	 * the rc_tmap. Note that if its NULL we must stop the timer. in all
558 	 * events we need to stop the running timer (if its running) before
559 	 * starting the new one.
560 	 */
561 	uint32_t thresh, exp, to, srtt, time_since_sent, tstmp_touse;
562 	int32_t idx;
563 	int32_t is_tlp_timer = 0;
564 	struct bbr_sendmap *rsm;
565 
566 	if (bbr->rc_all_timers_stopped) {
567 		/* All timers have been stopped none are to run */
568 		return (0);
569 	}
570 	if (bbr->rc_in_persist) {
571 		/* We can't start any timer in persists */
572 		return (bbr_get_persists_timer_val(tp, bbr));
573 	}
574 	rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
575 	if ((rsm == NULL) ||
576 	    ((tp->t_flags & TF_SACK_PERMIT) == 0) ||
577 	    (tp->t_state < TCPS_ESTABLISHED)) {
578 		/* Nothing on the send map */
579 activate_rxt:
580 		if (SEQ_LT(tp->snd_una, tp->snd_max) ||
581 		    sbavail(&tptosocket(tp)->so_snd)) {
582 			uint64_t tov;
583 
584 			time_since_sent = 0;
585 			rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
586 			if (rsm) {
587 				idx = rsm->r_rtr_cnt - 1;
588 				if (TSTMP_GEQ(rsm->r_tim_lastsent[idx], bbr->r_ctl.rc_tlp_rxt_last_time))
589 					tstmp_touse = rsm->r_tim_lastsent[idx];
590 				else
591 					tstmp_touse = bbr->r_ctl.rc_tlp_rxt_last_time;
592 				if (TSTMP_GT(tstmp_touse, cts))
593 				    time_since_sent = cts - tstmp_touse;
594 			}
595 			bbr->r_ctl.rc_hpts_flags |= PACE_TMR_RXT;
596 			if (tp->t_srtt == 0)
597 				tov = BBR_INITIAL_RTO;
598 			else
599 				tov = ((uint64_t)(TICKS_2_USEC(tp->t_srtt) +
600 				    ((uint64_t)TICKS_2_USEC(tp->t_rttvar) * (uint64_t)4)) >> TCP_RTT_SHIFT);
601 			if (tp->t_rxtshift)
602 				tov *= tcp_backoff[tp->t_rxtshift];
603 			if (tov > time_since_sent)
604 				tov -= time_since_sent;
605 			else
606 				tov = bbr->r_ctl.rc_min_to;
607 			TCPT_RANGESET_NOSLOP(to, tov,
608 			    (bbr->r_ctl.rc_min_rto_ms * MS_IN_USEC),
609 			    (bbr->rc_max_rto_sec * USECS_IN_SECOND));
610 			bbr_log_timer_var(bbr, 2, cts, 0, bbr_get_rtt(bbr, BBR_SRTT), 0, to);
611 			return (to);
612 		}
613 		return (0);
614 	}
615 	if (rsm->r_flags & BBR_ACKED) {
616 		rsm = bbr_find_lowest_rsm(bbr);
617 		if (rsm == NULL) {
618 			/* No lowest? */
619 			goto activate_rxt;
620 		}
621 	}
622 	/* Convert from ms to usecs */
623 	if (rsm->r_flags & BBR_SACK_PASSED) {
624 		if ((tp->t_flags & TF_SENTFIN) &&
625 		    ((tp->snd_max - tp->snd_una) == 1) &&
626 		    (rsm->r_flags & BBR_HAS_FIN)) {
627 			/*
628 			 * We don't start a bbr rack timer if all we have is
629 			 * a FIN outstanding.
630 			 */
631 			goto activate_rxt;
632 		}
633 		srtt = bbr_get_rtt(bbr, BBR_RTT_RACK);
634 		thresh = bbr_calc_thresh_rack(bbr, srtt, cts, rsm);
635 		idx = rsm->r_rtr_cnt - 1;
636 		exp = rsm->r_tim_lastsent[idx] + thresh;
637 		if (SEQ_GEQ(exp, cts)) {
638 			to = exp - cts;
639 			if (to < bbr->r_ctl.rc_min_to) {
640 				to = bbr->r_ctl.rc_min_to;
641 			}
642 		} else {
643 			to = bbr->r_ctl.rc_min_to;
644 		}
645 	} else {
646 		/* Ok we need to do a TLP not RACK */
647 		if (bbr->rc_tlp_in_progress != 0) {
648 			/*
649 			 * The previous send was a TLP.
650 			 */
651 			goto activate_rxt;
652 		}
653 		rsm = TAILQ_LAST_FAST(&bbr->r_ctl.rc_tmap, bbr_sendmap, r_tnext);
654 		if (rsm == NULL) {
655 			/* We found no rsm to TLP with. */
656 			goto activate_rxt;
657 		}
658 		if (rsm->r_flags & BBR_HAS_FIN) {
659 			/* If its a FIN we don't do TLP */
660 			rsm = NULL;
661 			goto activate_rxt;
662 		}
663 		time_since_sent = 0;
664 		idx = rsm->r_rtr_cnt - 1;
665 		if (TSTMP_GEQ(rsm->r_tim_lastsent[idx], bbr->r_ctl.rc_tlp_rxt_last_time))
666 			tstmp_touse = rsm->r_tim_lastsent[idx];
667 		else
668 			tstmp_touse = bbr->r_ctl.rc_tlp_rxt_last_time;
669 		if (TSTMP_GT(tstmp_touse, cts))
670 		    time_since_sent = cts - tstmp_touse;
671 		is_tlp_timer = 1;
672 		srtt = bbr_get_rtt(bbr, bbr_tlp_type_to_use);
673 		thresh = bbr_calc_thresh_tlp(tp, bbr, rsm, srtt, cts);
674 		if (thresh > time_since_sent)
675 			to = thresh - time_since_sent;
676 		else
677 			to = bbr->r_ctl.rc_min_to;
678 		if (to > (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND)) {
679 			/*
680 			 * If the TLP time works out to larger than the max
681 			 * RTO lets not do TLP.. just RTO.
682 			 */
683 			goto activate_rxt;
684 		}
685 		if ((bbr->rc_tlp_rtx_out == 1) &&
686 		    (rsm->r_start == bbr->r_ctl.rc_last_tlp_seq)) {
687 			/*
688 			 * Second retransmit of the same TLP
689 			 * lets not.
690 			 */
691 			bbr->rc_tlp_rtx_out = 0;
692 			goto activate_rxt;
693 		}
694 		if (rsm->r_start != bbr->r_ctl.rc_last_tlp_seq) {
695 			/*
696 			 * The tail is no longer the last one I did a probe
697 			 * on
698 			 */
699 			bbr->r_ctl.rc_tlp_seg_send_cnt = 0;
700 			bbr->r_ctl.rc_last_tlp_seq = rsm->r_start;
701 		}
702 	}
703 	if (is_tlp_timer == 0) {
704 		BBR_STAT_INC(bbr_to_arm_rack);
705 		bbr->r_ctl.rc_hpts_flags |= PACE_TMR_RACK;
706 	} else {
707 		bbr_log_timer_var(bbr, 1, cts, time_since_sent, srtt, thresh, to);
708 		if (bbr->r_ctl.rc_tlp_seg_send_cnt > bbr_tlp_max_resend) {
709 			/*
710 			 * We have exceeded how many times we can retran the
711 			 * current TLP timer, switch to the RTO timer.
712 			 */
713 			goto activate_rxt;
714 		} else {
715 			BBR_STAT_INC(bbr_to_arm_tlp);
716 			bbr->r_ctl.rc_hpts_flags |= PACE_TMR_TLP;
717 		}
718 	}
719 	return (to);
720 }
721 
722 static inline int32_t
723 bbr_minseg(struct tcp_bbr *bbr)
724 {
725 	return (bbr->r_ctl.rc_pace_min_segs - bbr->rc_last_options);
726 }
727 
728 static void
729 bbr_start_hpts_timer(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t cts, int32_t frm, int32_t slot, uint32_t tot_len)
730 {
731 	struct inpcb *inp = tptoinpcb(tp);
732 	struct hpts_diag diag;
733 	uint32_t delayed_ack = 0;
734 	uint32_t left = 0;
735 	uint32_t hpts_timeout;
736 	uint8_t stopped;
737 	int32_t delay_calc = 0;
738 	uint32_t prev_delay = 0;
739 
740 	if (tcp_in_hpts(tp)) {
741 		/* A previous call is already set up */
742 		return;
743 	}
744 	if ((tp->t_state == TCPS_CLOSED) ||
745 	    (tp->t_state == TCPS_LISTEN)) {
746 		return;
747 	}
748 	stopped = bbr->rc_tmr_stopped;
749 	if (stopped && TSTMP_GT(bbr->r_ctl.rc_timer_exp, cts)) {
750 		left = bbr->r_ctl.rc_timer_exp - cts;
751 	}
752 	bbr->r_ctl.rc_hpts_flags = 0;
753 	bbr->r_ctl.rc_timer_exp = 0;
754 	prev_delay = bbr->r_ctl.rc_last_delay_val;
755 	if (bbr->r_ctl.rc_last_delay_val &&
756 	    (slot == 0)) {
757 		/*
758 		 * If a previous pacer delay was in place we
759 		 * are not coming from the output side (where
760 		 * we calculate a delay, more likely a timer).
761 		 */
762 		slot = bbr->r_ctl.rc_last_delay_val;
763 		if (TSTMP_GT(cts, bbr->rc_pacer_started)) {
764 			/* Compensate for time passed  */
765 			delay_calc = cts - bbr->rc_pacer_started;
766 			if (delay_calc <= slot)
767 				slot -= delay_calc;
768 		}
769 	}
770 	/* Do we have early to make up for by pushing out the pacing time? */
771 	if (bbr->r_agg_early_set) {
772 		bbr_log_pacing_delay_calc(bbr, 0, bbr->r_ctl.rc_agg_early, cts, slot, 0, bbr->r_agg_early_set, 2);
773 		slot += bbr->r_ctl.rc_agg_early;
774 		bbr->r_ctl.rc_agg_early = 0;
775 		bbr->r_agg_early_set = 0;
776 	}
777 	/* Are we running a total debt that needs to be compensated for? */
778 	if (bbr->r_ctl.rc_hptsi_agg_delay) {
779 		if (slot > bbr->r_ctl.rc_hptsi_agg_delay) {
780 			/* We nuke the delay */
781 			slot -= bbr->r_ctl.rc_hptsi_agg_delay;
782 			bbr->r_ctl.rc_hptsi_agg_delay = 0;
783 		} else {
784 			/* We nuke some of the delay, put in a minimal 100usecs  */
785 			bbr->r_ctl.rc_hptsi_agg_delay -= slot;
786 			bbr->r_ctl.rc_last_delay_val = slot = 100;
787 		}
788 	}
789 	bbr->r_ctl.rc_last_delay_val = slot;
790 	hpts_timeout = bbr_timer_start(tp, bbr, cts);
791 	if (tp->t_flags & TF_DELACK) {
792 		if (bbr->rc_in_persist == 0) {
793 			delayed_ack = bbr_delack_time;
794 		} else {
795 			/*
796 			 * We are in persists and have
797 			 * gotten a new data element.
798 			 */
799 			if (hpts_timeout > bbr_delack_time) {
800 				/*
801 				 * Lets make the persists timer (which acks)
802 				 * be the smaller of hpts_timeout and bbr_delack_time.
803 				 */
804 				hpts_timeout = bbr_delack_time;
805 			}
806 		}
807 	}
808 	if (delayed_ack &&
809 	    ((hpts_timeout == 0) ||
810 	     (delayed_ack < hpts_timeout))) {
811 		/* We need a Delayed ack timer */
812 		bbr->r_ctl.rc_hpts_flags = PACE_TMR_DELACK;
813 		hpts_timeout = delayed_ack;
814 	}
815 	if (slot) {
816 		/* Mark that we have a pacing timer up */
817 		BBR_STAT_INC(bbr_paced_segments);
818 		bbr->r_ctl.rc_hpts_flags |= PACE_PKT_OUTPUT;
819 	}
820 	/*
821 	 * If no timers are going to run and we will fall off thfe hptsi
822 	 * wheel, we resort to a keep-alive timer if its configured.
823 	 */
824 	if ((hpts_timeout == 0) &&
825 	    (slot == 0)) {
826 		if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
827 		    (tp->t_state <= TCPS_CLOSING)) {
828 			/*
829 			 * Ok we have no timer (persists, rack, tlp, rxt  or
830 			 * del-ack), we don't have segments being paced. So
831 			 * all that is left is the keepalive timer.
832 			 */
833 			if (TCPS_HAVEESTABLISHED(tp->t_state)) {
834 				hpts_timeout = TICKS_2_USEC(TP_KEEPIDLE(tp));
835 			} else {
836 				hpts_timeout = TICKS_2_USEC(TP_KEEPINIT(tp));
837 			}
838 			bbr->r_ctl.rc_hpts_flags |= PACE_TMR_KEEP;
839 		}
840 	}
841 	if (left && (stopped & (PACE_TMR_KEEP | PACE_TMR_DELACK)) ==
842 	    (bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK)) {
843 		/*
844 		 * RACK, TLP, persists and RXT timers all are restartable
845 		 * based on actions input .. i.e we received a packet (ack
846 		 * or sack) and that changes things (rw, or snd_una etc).
847 		 * Thus we can restart them with a new value. For
848 		 * keep-alive, delayed_ack we keep track of what was left
849 		 * and restart the timer with a smaller value.
850 		 */
851 		if (left < hpts_timeout)
852 			hpts_timeout = left;
853 	}
854 	if (bbr->r_ctl.rc_incr_tmrs && slot &&
855 	    (bbr->r_ctl.rc_hpts_flags & (PACE_TMR_TLP|PACE_TMR_RXT))) {
856 		/*
857 		 * If configured to do so, and the timer is either
858 		 * the TLP or RXT timer, we need to increase the timeout
859 		 * by the pacing time. Consider the bottleneck at my
860 		 * machine as an example, we are sending something
861 		 * to start a TLP on. The last packet won't be emitted
862 		 * fully until the pacing time (the bottleneck will hold
863 		 * the data in place). Once the packet is emitted that
864 		 * is when we want to start waiting for the TLP. This
865 		 * is most evident with hardware pacing (where the nic
866 		 * is holding the packet(s) before emitting). But it
867 		 * can also show up in the network so we do it for all
868 		 * cases. Technically we would take off one packet from
869 		 * this extra delay but this is easier and being more
870 		 * conservative is probably better.
871 		 */
872 		hpts_timeout += slot;
873 	}
874 	if (hpts_timeout) {
875 		/*
876 		 * Hack alert for now we can't time-out over 2147 seconds (a
877 		 * bit more than 35min)
878 		 */
879 		if (hpts_timeout > 0x7ffffffe)
880 			hpts_timeout = 0x7ffffffe;
881 		bbr->r_ctl.rc_timer_exp = cts + hpts_timeout;
882 	} else
883 		bbr->r_ctl.rc_timer_exp = 0;
884 	if ((slot) &&
885 	    (bbr->rc_use_google ||
886 	     bbr->output_error_seen ||
887 	     (slot <= hpts_timeout))  ) {
888 		/*
889 		 * Tell LRO that it can queue packets while
890 		 * we pace.
891 		 */
892 		bbr->rc_tp->t_flags2 |= TF2_MBUF_QUEUE_READY;
893 		if ((bbr->r_ctl.rc_hpts_flags & PACE_TMR_RACK) &&
894 		    (bbr->rc_cwnd_limited == 0)) {
895 			/*
896 			 * If we are not cwnd limited and we
897 			 * are running a rack timer we put on
898 			 * the do not disturbe even for sack.
899 			 */
900 			tp->t_flags2 |= TF2_DONT_SACK_QUEUE;
901 		} else
902 			tp->t_flags2 &= ~TF2_DONT_SACK_QUEUE;
903 		bbr->rc_pacer_started = cts;
904 
905 		(void)tcp_hpts_insert_diag(tp, HPTS_USEC_TO_SLOTS(slot),
906 					   __LINE__, &diag);
907 		bbr->rc_timer_first = 0;
908 		bbr->bbr_timer_src = frm;
909 		bbr_log_to_start(bbr, cts, hpts_timeout, slot, 1);
910 		bbr_log_hpts_diag(bbr, cts, &diag);
911 	} else if (hpts_timeout) {
912 		(void)tcp_hpts_insert_diag(tp, HPTS_USEC_TO_SLOTS(hpts_timeout),
913 					   __LINE__, &diag);
914 		/*
915 		 * We add the flag here as well if the slot is set,
916 		 * since hpts will call in to clear the queue first before
917 		 * calling the output routine (which does our timers).
918 		 * We don't want to set the flag if its just a timer
919 		 * else the arrival of data might (that causes us
920 		 * to send more) might get delayed. Imagine being
921 		 * on a keep-alive timer and a request comes in for
922 		 * more data.
923 		 */
924 		if (slot)
925 			bbr->rc_pacer_started = cts;
926 		if ((bbr->r_ctl.rc_hpts_flags & PACE_TMR_RACK) &&
927 		    (bbr->rc_cwnd_limited == 0)) {
928 			/*
929 			 * For a rack timer, don't wake us even
930 			 * if a sack arrives as long as we are
931 			 * not cwnd limited.
932 			 */
933 			tp->t_flags2 |= (TF2_MBUF_QUEUE_READY |
934 			    TF2_DONT_SACK_QUEUE);
935 		} else {
936 			/* All other timers wake us up */
937 			tp->t_flags2 &= ~(TF2_MBUF_QUEUE_READY |
938 			    TF2_DONT_SACK_QUEUE);
939 		}
940 		bbr->bbr_timer_src = frm;
941 		bbr_log_to_start(bbr, cts, hpts_timeout, slot, 0);
942 		bbr_log_hpts_diag(bbr, cts, &diag);
943 		bbr->rc_timer_first = 1;
944 	}
945 	bbr->rc_tmr_stopped = 0;
946 	bbr_log_type_bbrsnd(bbr, tot_len, slot, delay_calc, cts, frm, prev_delay);
947 }
948 
949 static void
950 bbr_timer_audit(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts, struct sockbuf *sb)
951 {
952 	/*
953 	 * We received an ack, and then did not call send or were bounced
954 	 * out due to the hpts was running. Now a timer is up as well, is it
955 	 * the right timer?
956 	 */
957 	struct inpcb *inp;
958 	struct bbr_sendmap *rsm;
959 	uint32_t hpts_timeout;
960 	int tmr_up;
961 
962 	tmr_up = bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
963 	if (bbr->rc_in_persist && (tmr_up == PACE_TMR_PERSIT))
964 		return;
965 	rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
966 	if (((rsm == NULL) || (tp->t_state < TCPS_ESTABLISHED)) &&
967 	    (tmr_up == PACE_TMR_RXT)) {
968 		/* Should be an RXT */
969 		return;
970 	}
971 	inp = bbr->rc_inp;
972 	if (rsm == NULL) {
973 		/* Nothing outstanding? */
974 		if (tp->t_flags & TF_DELACK) {
975 			if (tmr_up == PACE_TMR_DELACK)
976 				/*
977 				 * We are supposed to have delayed ack up
978 				 * and we do
979 				 */
980 				return;
981 		} else if (((V_tcp_always_keepalive ||
982 			    inp->inp_socket->so_options & SO_KEEPALIVE) &&
983 			    (tp->t_state <= TCPS_CLOSING)) &&
984 			    (tmr_up == PACE_TMR_KEEP) &&
985 		    (tp->snd_max == tp->snd_una)) {
986 			/* We should have keep alive up and we do */
987 			return;
988 		}
989 	}
990 	if (rsm && (rsm->r_flags & BBR_SACK_PASSED)) {
991 		if ((tp->t_flags & TF_SENTFIN) &&
992 		    ((tp->snd_max - tp->snd_una) == 1) &&
993 		    (rsm->r_flags & BBR_HAS_FIN)) {
994 			/* needs to be a RXT */
995 			if (tmr_up == PACE_TMR_RXT)
996 				return;
997 			else
998 				goto wrong_timer;
999 		} else if (tmr_up == PACE_TMR_RACK)
1000 			return;
1001 		else
1002 			goto wrong_timer;
1003 	} else if (rsm && (tmr_up == PACE_TMR_RACK)) {
1004 		/* Rack timer has priority if we have data out */
1005 		return;
1006 	} else if (SEQ_GT(tp->snd_max, tp->snd_una) &&
1007 		    ((tmr_up == PACE_TMR_TLP) ||
1008 	    (tmr_up == PACE_TMR_RXT))) {
1009 		/*
1010 		 * Either a TLP or RXT is fine if no sack-passed is in place
1011 		 * and data is outstanding.
1012 		 */
1013 		return;
1014 	} else if (tmr_up == PACE_TMR_DELACK) {
1015 		/*
1016 		 * If the delayed ack was going to go off before the
1017 		 * rtx/tlp/rack timer were going to expire, then that would
1018 		 * be the timer in control. Note we don't check the time
1019 		 * here trusting the code is correct.
1020 		 */
1021 		return;
1022 	}
1023 	if (SEQ_GT(tp->snd_max, tp->snd_una) &&
1024 	    ((tmr_up == PACE_TMR_RXT) ||
1025 	     (tmr_up == PACE_TMR_TLP) ||
1026 	     (tmr_up == PACE_TMR_RACK))) {
1027 		/*
1028 		 * We have outstanding data and
1029 		 * we *do* have a RACK, TLP or RXT
1030 		 * timer running. We won't restart
1031 		 * anything here since thats probably ok we
1032 		 * will get called with some timer here shortly.
1033 		 */
1034 		return;
1035 	}
1036 	/*
1037 	 * Ok the timer originally started is not what we want now. We will
1038 	 * force the hpts to be stopped if any, and restart with the slot
1039 	 * set to what was in the saved slot.
1040 	 */
1041 wrong_timer:
1042 	if ((bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) {
1043 		if (tcp_in_hpts(tp))
1044 			tcp_hpts_remove(tp);
1045 		bbr_timer_cancel(bbr, __LINE__, cts);
1046 		bbr_start_hpts_timer(bbr, tp, cts, 1, bbr->r_ctl.rc_last_delay_val,
1047 		    0);
1048 	} else {
1049 		/*
1050 		 * Output is hptsi so we just need to switch the type of
1051 		 * timer. We don't bother with keep-alive, since when we
1052 		 * jump through the output, it will start the keep-alive if
1053 		 * nothing is sent.
1054 		 *
1055 		 * We only need a delayed-ack added and or the hpts_timeout.
1056 		 */
1057 		hpts_timeout = bbr_timer_start(tp, bbr, cts);
1058 		if (tp->t_flags & TF_DELACK) {
1059 			if (hpts_timeout == 0) {
1060 				hpts_timeout = bbr_delack_time;
1061 				bbr->r_ctl.rc_hpts_flags = PACE_TMR_DELACK;
1062 			}
1063 			else if (hpts_timeout > bbr_delack_time) {
1064 				hpts_timeout = bbr_delack_time;
1065 				bbr->r_ctl.rc_hpts_flags = PACE_TMR_DELACK;
1066 			}
1067 		}
1068 		if (hpts_timeout) {
1069 			if (hpts_timeout > 0x7ffffffe)
1070 				hpts_timeout = 0x7ffffffe;
1071 			bbr->r_ctl.rc_timer_exp = cts + hpts_timeout;
1072 		}
1073 	}
1074 }
1075 
1076 int32_t bbr_clear_lost = 0;
1077 
1078 /*
1079  * Considers the two time values now (cts) and earlier.
1080  * If cts is smaller than earlier, we could have
1081  * had a sequence wrap (our counter wraps every
1082  * 70 min or so) or it could be just clock skew
1083  * getting us two different time values. Clock skew
1084  * will show up within 10ms or so. So in such
1085  * a case (where cts is behind earlier time by
1086  * less than 10ms) we return 0. Otherwise we
1087  * return the true difference between them.
1088  */
1089 static inline uint32_t
1090 bbr_calc_time(uint32_t cts, uint32_t earlier_time) {
1091 	/*
1092 	 * Given two timestamps, the current time stamp cts, and some other
1093 	 * time-stamp taken in theory earlier return the difference. The
1094 	 * trick is here sometimes locking will get the other timestamp
1095 	 * after the cts. If this occurs we need to return 0.
1096 	 */
1097 	if (TSTMP_GEQ(cts, earlier_time))
1098 		return (cts - earlier_time);
1099 	/*
1100 	 * cts is behind earlier_time if its less than 10ms consider it 0.
1101 	 * If its more than 10ms difference then we had a time wrap. Else
1102 	 * its just the normal locking foo. I wonder if we should not go to
1103 	 * 64bit TS and get rid of this issue.
1104 	 */
1105 	if (TSTMP_GEQ((cts + 10000), earlier_time))
1106 		return (0);
1107 	/*
1108 	 * Ok the time must have wrapped. So we need to answer a large
1109 	 * amount of time, which the normal subtraction should do.
1110 	 */
1111 	return (cts - earlier_time);
1112 }
1113 
1114 static int
1115 sysctl_bbr_clear_lost(SYSCTL_HANDLER_ARGS)
1116 {
1117 	uint32_t stat;
1118 	int32_t error;
1119 
1120 	error = SYSCTL_OUT(req, &bbr_clear_lost, sizeof(uint32_t));
1121 	if (error || req->newptr == NULL)
1122 		return error;
1123 
1124 	error = SYSCTL_IN(req, &stat, sizeof(uint32_t));
1125 	if (error)
1126 		return (error);
1127 	if (stat == 1) {
1128 #ifdef BBR_INVARIANTS
1129 		printf("Clearing BBR lost counters\n");
1130 #endif
1131 		COUNTER_ARRAY_ZERO(bbr_state_lost, BBR_MAX_STAT);
1132 		COUNTER_ARRAY_ZERO(bbr_state_time, BBR_MAX_STAT);
1133 		COUNTER_ARRAY_ZERO(bbr_state_resend, BBR_MAX_STAT);
1134 	} else if (stat == 2) {
1135 #ifdef BBR_INVARIANTS
1136 		printf("Clearing BBR option counters\n");
1137 #endif
1138 		COUNTER_ARRAY_ZERO(bbr_opts_arry, BBR_OPTS_SIZE);
1139 	} else if (stat == 3) {
1140 #ifdef BBR_INVARIANTS
1141 		printf("Clearing BBR stats counters\n");
1142 #endif
1143 		COUNTER_ARRAY_ZERO(bbr_stat_arry, BBR_STAT_SIZE);
1144 	} else if (stat == 4) {
1145 #ifdef BBR_INVARIANTS
1146 		printf("Clearing BBR out-size counters\n");
1147 #endif
1148 		COUNTER_ARRAY_ZERO(bbr_out_size, TCP_MSS_ACCT_SIZE);
1149 	}
1150 	bbr_clear_lost = 0;
1151 	return (0);
1152 }
1153 
1154 static void
1155 bbr_init_sysctls(void)
1156 {
1157 	struct sysctl_oid *bbr_probertt;
1158 	struct sysctl_oid *bbr_hptsi;
1159 	struct sysctl_oid *bbr_measure;
1160 	struct sysctl_oid *bbr_cwnd;
1161 	struct sysctl_oid *bbr_timeout;
1162 	struct sysctl_oid *bbr_states;
1163 	struct sysctl_oid *bbr_startup;
1164 	struct sysctl_oid *bbr_policer;
1165 
1166 	/* Probe rtt controls */
1167 	bbr_probertt = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1168 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1169 	    OID_AUTO,
1170 	    "probertt",
1171 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1172 	    "");
1173 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1174 	    SYSCTL_CHILDREN(bbr_probertt),
1175 	    OID_AUTO, "gain", CTLFLAG_RW,
1176 	    &bbr_rttprobe_gain, 192,
1177 	    "What is the filter gain drop in probe_rtt (0=disable)?");
1178 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1179 	    SYSCTL_CHILDREN(bbr_probertt),
1180 	    OID_AUTO, "cwnd", CTLFLAG_RW,
1181 	    &bbr_rtt_probe_cwndtarg, 4,
1182 	    "How many mss's are outstanding during probe-rtt");
1183 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1184 	    SYSCTL_CHILDREN(bbr_probertt),
1185 	    OID_AUTO, "int", CTLFLAG_RW,
1186 	    &bbr_rtt_probe_limit, 4000000,
1187 	    "If RTT has not shrank in this many micro-seconds enter probe-rtt");
1188 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1189 	    SYSCTL_CHILDREN(bbr_probertt),
1190 	    OID_AUTO, "mintime", CTLFLAG_RW,
1191 	    &bbr_rtt_probe_time, 200000,
1192 	    "How many microseconds in probe-rtt");
1193 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1194 	    SYSCTL_CHILDREN(bbr_probertt),
1195 	    OID_AUTO, "filter_len_sec", CTLFLAG_RW,
1196 	    &bbr_filter_len_sec, 6,
1197 	    "How long in seconds does the rttProp filter run?");
1198 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1199 	    SYSCTL_CHILDREN(bbr_probertt),
1200 	    OID_AUTO, "drain_rtt", CTLFLAG_RW,
1201 	    &bbr_drain_rtt, BBR_SRTT,
1202 	    "What is the drain rtt to use in probeRTT (rtt_prop=0, rtt_rack=1, rtt_pkt=2, rtt_srtt=3?");
1203 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1204 	    SYSCTL_CHILDREN(bbr_probertt),
1205 	    OID_AUTO, "can_force", CTLFLAG_RW,
1206 	    &bbr_can_force_probertt, 0,
1207 	    "If we keep setting new low rtt's but delay going in probe-rtt can we force in??");
1208 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1209 	    SYSCTL_CHILDREN(bbr_probertt),
1210 	    OID_AUTO, "enter_sets_force", CTLFLAG_RW,
1211 	    &bbr_probertt_sets_rtt, 0,
1212 	    "In NF mode, do we imitate google_mode and set the rttProp on entry to probe-rtt?");
1213 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1214 	    SYSCTL_CHILDREN(bbr_probertt),
1215 	    OID_AUTO, "can_adjust", CTLFLAG_RW,
1216 	    &bbr_can_adjust_probertt, 1,
1217 	    "Can we dynamically adjust the probe-rtt limits and times?");
1218 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1219 	    SYSCTL_CHILDREN(bbr_probertt),
1220 	    OID_AUTO, "is_ratio", CTLFLAG_RW,
1221 	    &bbr_is_ratio, 0,
1222 	    "is the limit to filter a ratio?");
1223 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1224 	    SYSCTL_CHILDREN(bbr_probertt),
1225 	    OID_AUTO, "use_cwnd", CTLFLAG_RW,
1226 	    &bbr_prtt_slam_cwnd, 0,
1227 	    "Should we set/recover cwnd?");
1228 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1229 	    SYSCTL_CHILDREN(bbr_probertt),
1230 	    OID_AUTO, "can_use_ts", CTLFLAG_RW,
1231 	    &bbr_can_use_ts_for_rtt, 1,
1232 	    "Can we use the ms timestamp if available for retransmistted rtt calculations?");
1233 
1234 	/* Pacing controls */
1235 	bbr_hptsi = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1236 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1237 	    OID_AUTO,
1238 	    "pacing",
1239 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1240 	    "");
1241 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1242 	    SYSCTL_CHILDREN(bbr_hptsi),
1243 	    OID_AUTO, "hw_pacing", CTLFLAG_RW,
1244 	    &bbr_allow_hdwr_pacing, 1,
1245 	    "Do we allow hardware pacing?");
1246 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1247 	    SYSCTL_CHILDREN(bbr_hptsi),
1248 	    OID_AUTO, "hw_pacing_limit", CTLFLAG_RW,
1249 	    &bbr_hardware_pacing_limit, 4000,
1250 	    "Do we have a limited number of connections for pacing chelsio (0=no limit)?");
1251 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1252 	    SYSCTL_CHILDREN(bbr_hptsi),
1253 	    OID_AUTO, "hw_pacing_adj", CTLFLAG_RW,
1254 	    &bbr_hdwr_pace_adjust, 2,
1255 	    "Multiplier to calculated tso size?");
1256 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1257 	    SYSCTL_CHILDREN(bbr_hptsi),
1258 	    OID_AUTO, "hw_pacing_floor", CTLFLAG_RW,
1259 	    &bbr_hdwr_pace_floor, 1,
1260 	    "Do we invoke the hardware pacing floor?");
1261 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1262 	    SYSCTL_CHILDREN(bbr_hptsi),
1263 	    OID_AUTO, "hw_pacing_delay_cnt", CTLFLAG_RW,
1264 	    &bbr_hdwr_pacing_delay_cnt, 10,
1265 	    "How many packets must be sent after hdwr pacing is enabled");
1266 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1267 	    SYSCTL_CHILDREN(bbr_hptsi),
1268 	    OID_AUTO, "bw_cross", CTLFLAG_RW,
1269 	    &bbr_cross_over, 3000000,
1270 	    "What is the point where we cross over to linux like TSO size set");
1271 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1272 	    SYSCTL_CHILDREN(bbr_hptsi),
1273 	    OID_AUTO, "seg_deltarg", CTLFLAG_RW,
1274 	    &bbr_hptsi_segments_delay_tar, 7000,
1275 	    "What is the worse case delay target for hptsi < 48Mbp connections");
1276 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1277 	    SYSCTL_CHILDREN(bbr_hptsi),
1278 	    OID_AUTO, "enet_oh", CTLFLAG_RW,
1279 	    &bbr_include_enet_oh, 0,
1280 	    "Do we include the ethernet overhead in calculating pacing delay?");
1281 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1282 	    SYSCTL_CHILDREN(bbr_hptsi),
1283 	    OID_AUTO, "ip_oh", CTLFLAG_RW,
1284 	    &bbr_include_ip_oh, 1,
1285 	    "Do we include the IP overhead in calculating pacing delay?");
1286 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1287 	    SYSCTL_CHILDREN(bbr_hptsi),
1288 	    OID_AUTO, "tcp_oh", CTLFLAG_RW,
1289 	    &bbr_include_tcp_oh, 0,
1290 	    "Do we include the TCP overhead in calculating pacing delay?");
1291 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1292 	    SYSCTL_CHILDREN(bbr_hptsi),
1293 	    OID_AUTO, "google_discount", CTLFLAG_RW,
1294 	    &bbr_google_discount, 10,
1295 	    "What is the default google discount percentage wise for pacing (11 = 1.1%%)?");
1296 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1297 	    SYSCTL_CHILDREN(bbr_hptsi),
1298 	    OID_AUTO, "all_get_min", CTLFLAG_RW,
1299 	    &bbr_all_get_min, 0,
1300 	    "If you are less than a MSS do you just get the min?");
1301 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1302 	    SYSCTL_CHILDREN(bbr_hptsi),
1303 	    OID_AUTO, "tso_min", CTLFLAG_RW,
1304 	    &bbr_hptsi_bytes_min, 1460,
1305 	    "For 0 -> 24Mbps what is floor number of segments for TSO");
1306 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1307 	    SYSCTL_CHILDREN(bbr_hptsi),
1308 	    OID_AUTO, "seg_tso_max", CTLFLAG_RW,
1309 	    &bbr_hptsi_segments_max, 6,
1310 	    "For 0 -> 24Mbps what is top number of segments for TSO");
1311 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1312 	    SYSCTL_CHILDREN(bbr_hptsi),
1313 	    OID_AUTO, "seg_floor", CTLFLAG_RW,
1314 	    &bbr_hptsi_segments_floor, 1,
1315 	    "Minimum TSO size we will fall too in segments");
1316 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1317 	    SYSCTL_CHILDREN(bbr_hptsi),
1318 	    OID_AUTO, "utter_max", CTLFLAG_RW,
1319 	    &bbr_hptsi_utter_max, 0,
1320 	    "The absolute maximum that any pacing (outside of hardware) can be");
1321 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1322 	    SYSCTL_CHILDREN(bbr_hptsi),
1323 	    OID_AUTO, "seg_divisor", CTLFLAG_RW,
1324 	    &bbr_hptsi_per_second, 100,
1325 	    "What is the divisor in our hptsi TSO calculation 512Mbps < X > 24Mbps ");
1326 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1327 	    SYSCTL_CHILDREN(bbr_hptsi),
1328 	    OID_AUTO, "srtt_mul", CTLFLAG_RW,
1329 	    &bbr_hptsi_max_mul, 1,
1330 	    "The multiplier for pace len max");
1331 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1332 	    SYSCTL_CHILDREN(bbr_hptsi),
1333 	    OID_AUTO, "srtt_div", CTLFLAG_RW,
1334 	    &bbr_hptsi_max_div, 2,
1335 	    "The divisor for pace len max");
1336 	/* Measurement controls */
1337 	bbr_measure = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1338 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1339 	    OID_AUTO,
1340 	    "measure",
1341 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1342 	    "Measurement controls");
1343 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1344 	    SYSCTL_CHILDREN(bbr_measure),
1345 	    OID_AUTO, "min_i_bw", CTLFLAG_RW,
1346 	    &bbr_initial_bw_bps, 62500,
1347 	    "Minimum initial b/w in bytes per second");
1348 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1349 	    SYSCTL_CHILDREN(bbr_measure),
1350 	    OID_AUTO, "no_sack_needed", CTLFLAG_RW,
1351 	    &bbr_sack_not_required, 0,
1352 	    "Do we allow bbr to run on connections not supporting SACK?");
1353 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1354 	    SYSCTL_CHILDREN(bbr_measure),
1355 	    OID_AUTO, "use_google", CTLFLAG_RW,
1356 	    &bbr_use_google_algo, 0,
1357 	    "Use has close to google V1.0 has possible?");
1358 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1359 	    SYSCTL_CHILDREN(bbr_measure),
1360 	    OID_AUTO, "ts_limiting", CTLFLAG_RW,
1361 	    &bbr_ts_limiting, 1,
1362 	    "Do we attempt to use the peers timestamp to limit b/w caculations?");
1363 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1364 	    SYSCTL_CHILDREN(bbr_measure),
1365 	    OID_AUTO, "ts_can_raise", CTLFLAG_RW,
1366 	    &bbr_ts_can_raise, 0,
1367 	    "Can we raise the b/w via timestamp b/w calculation?");
1368 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1369 	    SYSCTL_CHILDREN(bbr_measure),
1370 	    OID_AUTO, "ts_delta", CTLFLAG_RW,
1371 	    &bbr_min_usec_delta, 20000,
1372 	    "How long in usec between ts of our sends in ts validation code?");
1373 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1374 	    SYSCTL_CHILDREN(bbr_measure),
1375 	    OID_AUTO, "ts_peer_delta", CTLFLAG_RW,
1376 	    &bbr_min_peer_delta, 20,
1377 	    "What min numerical value should be between the peer deltas?");
1378 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1379 	    SYSCTL_CHILDREN(bbr_measure),
1380 	    OID_AUTO, "ts_delta_percent", CTLFLAG_RW,
1381 	    &bbr_delta_percent, 150,
1382 	    "What percentage (150 = 15.0) do we allow variance for?");
1383 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1384 	    SYSCTL_CHILDREN(bbr_measure),
1385 	    OID_AUTO, "min_measure_good_bw", CTLFLAG_RW,
1386 	    &bbr_min_measurements_req, 1,
1387 	    "What is the minimum measurement count we need before we switch to our b/w estimate");
1388 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1389 	    SYSCTL_CHILDREN(bbr_measure),
1390 	    OID_AUTO, "min_measure_before_pace", CTLFLAG_RW,
1391 	    &bbr_no_pacing_until, 4,
1392 	    "How many pkt-epoch's (0 is off) do we need before pacing is on?");
1393 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1394 	    SYSCTL_CHILDREN(bbr_measure),
1395 	    OID_AUTO, "quanta", CTLFLAG_RW,
1396 	    &bbr_quanta, 2,
1397 	    "Extra quanta to add when calculating the target (ID section 4.2.3.2).");
1398 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1399 	    SYSCTL_CHILDREN(bbr_measure),
1400 	    OID_AUTO, "noretran", CTLFLAG_RW,
1401 	    &bbr_no_retran, 0,
1402 	    "Should google mode not use retransmission measurements for the b/w estimation?");
1403 	/* State controls */
1404 	bbr_states = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1405 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1406 	    OID_AUTO,
1407 	    "states",
1408 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1409 	    "State controls");
1410 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1411 	    SYSCTL_CHILDREN(bbr_states),
1412 	    OID_AUTO, "idle_restart", CTLFLAG_RW,
1413 	    &bbr_uses_idle_restart, 0,
1414 	    "Do we use a new special idle_restart state to ramp back up quickly?");
1415 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1416 	    SYSCTL_CHILDREN(bbr_states),
1417 	    OID_AUTO, "idle_restart_threshold", CTLFLAG_RW,
1418 	    &bbr_idle_restart_threshold, 100000,
1419 	    "How long must we be idle before we restart??");
1420 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1421 	    SYSCTL_CHILDREN(bbr_states),
1422 	    OID_AUTO, "use_pkt_epoch", CTLFLAG_RW,
1423 	    &bbr_state_is_pkt_epoch, 0,
1424 	    "Do we use a pkt-epoch for substate if 0 rttProp?");
1425 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1426 	    SYSCTL_CHILDREN(bbr_states),
1427 	    OID_AUTO, "startup_rtt_gain", CTLFLAG_RW,
1428 	    &bbr_rtt_gain_thresh, 0,
1429 	    "What increase in RTT triggers us to stop ignoring no-loss and possibly exit startup?");
1430 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1431 	    SYSCTL_CHILDREN(bbr_states),
1432 	    OID_AUTO, "drain_floor", CTLFLAG_RW,
1433 	    &bbr_drain_floor, 88,
1434 	    "What is the lowest we can drain (pg) too?");
1435 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1436 	    SYSCTL_CHILDREN(bbr_states),
1437 	    OID_AUTO, "drain_2_target", CTLFLAG_RW,
1438 	    &bbr_state_drain_2_tar, 1,
1439 	    "Do we drain to target in drain substate?");
1440 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1441 	    SYSCTL_CHILDREN(bbr_states),
1442 	    OID_AUTO, "gain_2_target", CTLFLAG_RW,
1443 	    &bbr_gain_to_target, 1,
1444 	    "Does probe bw gain to target??");
1445 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1446 	    SYSCTL_CHILDREN(bbr_states),
1447 	    OID_AUTO, "gain_extra_time", CTLFLAG_RW,
1448 	    &bbr_gain_gets_extra_too, 1,
1449 	    "Does probe bw gain get the extra time too?");
1450 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1451 	    SYSCTL_CHILDREN(bbr_states),
1452 	    OID_AUTO, "ld_div", CTLFLAG_RW,
1453 	    &bbr_drain_drop_div, 5,
1454 	    "Long drain drop divider?");
1455 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1456 	    SYSCTL_CHILDREN(bbr_states),
1457 	    OID_AUTO, "ld_mul", CTLFLAG_RW,
1458 	    &bbr_drain_drop_mul, 4,
1459 	    "Long drain drop multiplier?");
1460 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1461 	    SYSCTL_CHILDREN(bbr_states),
1462 	    OID_AUTO, "rand_ot_disc", CTLFLAG_RW,
1463 	    &bbr_rand_ot, 50,
1464 	    "Random discount of the ot?");
1465 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1466 	    SYSCTL_CHILDREN(bbr_states),
1467 	    OID_AUTO, "dr_filter_life", CTLFLAG_RW,
1468 	    &bbr_num_pktepo_for_del_limit, BBR_NUM_RTTS_FOR_DEL_LIMIT,
1469 	    "How many packet-epochs does the b/w delivery rate last?");
1470 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1471 	    SYSCTL_CHILDREN(bbr_states),
1472 	    OID_AUTO, "subdrain_applimited", CTLFLAG_RW,
1473 	    &bbr_sub_drain_app_limit, 0,
1474 	    "Does our sub-state drain invoke app limited if its long?");
1475 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1476 	    SYSCTL_CHILDREN(bbr_states),
1477 	    OID_AUTO, "use_cwnd_subdrain", CTLFLAG_RW,
1478 	    &bbr_sub_drain_slam_cwnd, 0,
1479 	    "Should we set/recover cwnd for sub-state drain?");
1480 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1481 	    SYSCTL_CHILDREN(bbr_states),
1482 	    OID_AUTO, "use_cwnd_maindrain", CTLFLAG_RW,
1483 	    &bbr_slam_cwnd_in_main_drain, 0,
1484 	    "Should we set/recover cwnd for main-state drain?");
1485 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1486 	    SYSCTL_CHILDREN(bbr_states),
1487 	    OID_AUTO, "google_gets_earlyout", CTLFLAG_RW,
1488 	    &google_allow_early_out, 1,
1489 	    "Should we allow google probe-bw/drain to exit early at flight target?");
1490 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1491 	    SYSCTL_CHILDREN(bbr_states),
1492 	    OID_AUTO, "google_exit_loss", CTLFLAG_RW,
1493 	    &google_consider_lost, 1,
1494 	    "Should we have losses exit gain of probebw in google mode??");
1495 	/* Startup controls */
1496 	bbr_startup = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1497 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1498 	    OID_AUTO,
1499 	    "startup",
1500 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1501 	    "Startup controls");
1502 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1503 	    SYSCTL_CHILDREN(bbr_startup),
1504 	    OID_AUTO, "cheat_iwnd", CTLFLAG_RW,
1505 	    &bbr_sends_full_iwnd, 1,
1506 	    "Do we not pace but burst out initial windows has our TSO size?");
1507 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1508 	    SYSCTL_CHILDREN(bbr_startup),
1509 	    OID_AUTO, "loss_threshold", CTLFLAG_RW,
1510 	    &bbr_startup_loss_thresh, 2000,
1511 	    "In startup what is the loss threshold in a pe that will exit us from startup?");
1512 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1513 	    SYSCTL_CHILDREN(bbr_startup),
1514 	    OID_AUTO, "use_lowerpg", CTLFLAG_RW,
1515 	    &bbr_use_lower_gain_in_startup, 1,
1516 	    "Should we use a lower hptsi gain if we see loss in startup?");
1517 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1518 	    SYSCTL_CHILDREN(bbr_startup),
1519 	    OID_AUTO, "gain", CTLFLAG_RW,
1520 	    &bbr_start_exit, 25,
1521 	    "What gain percent do we need to see to stay in startup??");
1522 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1523 	    SYSCTL_CHILDREN(bbr_startup),
1524 	    OID_AUTO, "low_gain", CTLFLAG_RW,
1525 	    &bbr_low_start_exit, 15,
1526 	    "What gain percent do we need to see to stay in the lower gain startup??");
1527 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1528 	    SYSCTL_CHILDREN(bbr_startup),
1529 	    OID_AUTO, "loss_exit", CTLFLAG_RW,
1530 	    &bbr_exit_startup_at_loss, 1,
1531 	    "Should we exit startup at loss in an epoch if we are not gaining?");
1532 	/* CWND controls */
1533 	bbr_cwnd = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1534 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1535 	    OID_AUTO,
1536 	    "cwnd",
1537 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1538 	    "Cwnd controls");
1539 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1540 	    SYSCTL_CHILDREN(bbr_cwnd),
1541 	    OID_AUTO, "tar_rtt", CTLFLAG_RW,
1542 	    &bbr_cwndtarget_rtt_touse, 0,
1543 	    "Target cwnd rtt measurement to use (0=rtt_prop, 1=rtt_rack, 2=pkt_rtt, 3=srtt)?");
1544 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1545 	    SYSCTL_CHILDREN(bbr_cwnd),
1546 	    OID_AUTO, "may_shrink", CTLFLAG_RW,
1547 	    &bbr_cwnd_may_shrink, 0,
1548 	    "Can the cwnd shrink if it would grow to more than the target?");
1549 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1550 	    SYSCTL_CHILDREN(bbr_cwnd),
1551 	    OID_AUTO, "max_target_limit", CTLFLAG_RW,
1552 	    &bbr_target_cwnd_mult_limit, 8,
1553 	    "Do we limit the cwnd to some multiple of the cwnd target if cwnd can't shrink 0=no?");
1554 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1555 	    SYSCTL_CHILDREN(bbr_cwnd),
1556 	    OID_AUTO, "highspeed_min", CTLFLAG_RW,
1557 	    &bbr_cwnd_min_val_hs, BBR_HIGHSPEED_NUM_MSS,
1558 	    "What is the high-speed min cwnd (rttProp under 1ms)");
1559 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1560 	    SYSCTL_CHILDREN(bbr_cwnd),
1561 	    OID_AUTO, "lowspeed_min", CTLFLAG_RW,
1562 	    &bbr_cwnd_min_val, BBR_PROBERTT_NUM_MSS,
1563 	    "What is the min cwnd (rttProp > 1ms)");
1564 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1565 	    SYSCTL_CHILDREN(bbr_cwnd),
1566 	    OID_AUTO, "initwin", CTLFLAG_RW,
1567 	    &bbr_def_init_win, 10,
1568 	    "What is the BBR initial window, if 0 use tcp version");
1569 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1570 	    SYSCTL_CHILDREN(bbr_cwnd),
1571 	    OID_AUTO, "do_loss_red", CTLFLAG_RW,
1572 	    &bbr_do_red, 600,
1573 	    "Do we reduce the b/w at exit from recovery based on ratio of prop/srtt (800=80.0, 0=off)?");
1574 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1575 	    SYSCTL_CHILDREN(bbr_cwnd),
1576 	    OID_AUTO, "red_scale", CTLFLAG_RW,
1577 	    &bbr_red_scale, 20000,
1578 	    "What RTT do we scale with?");
1579 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1580 	    SYSCTL_CHILDREN(bbr_cwnd),
1581 	    OID_AUTO, "red_growslow", CTLFLAG_RW,
1582 	    &bbr_red_growth_restrict, 1,
1583 	    "Do we restrict cwnd growth for whats in flight?");
1584 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1585 	    SYSCTL_CHILDREN(bbr_cwnd),
1586 	    OID_AUTO, "red_div", CTLFLAG_RW,
1587 	    &bbr_red_div, 2,
1588 	    "If we reduce whats the divisor?");
1589 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1590 	    SYSCTL_CHILDREN(bbr_cwnd),
1591 	    OID_AUTO, "red_mul", CTLFLAG_RW,
1592 	    &bbr_red_mul, 1,
1593 	    "If we reduce whats the mulitiplier?");
1594 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1595 	    SYSCTL_CHILDREN(bbr_cwnd),
1596 	    OID_AUTO, "target_is_unit", CTLFLAG_RW,
1597 	    &bbr_target_is_bbunit, 0,
1598 	    "Is the state target the pacing_gain or BBR_UNIT?");
1599 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1600 	    SYSCTL_CHILDREN(bbr_cwnd),
1601 	    OID_AUTO, "drop_limit", CTLFLAG_RW,
1602 	    &bbr_drop_limit, 0,
1603 	    "Number of segments limit for drop (0=use min_cwnd w/flight)?");
1604 
1605 	/* Timeout controls */
1606 	bbr_timeout = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1607 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1608 	    OID_AUTO,
1609 	    "timeout",
1610 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1611 	    "Time out controls");
1612 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1613 	    SYSCTL_CHILDREN(bbr_timeout),
1614 	    OID_AUTO, "delack", CTLFLAG_RW,
1615 	    &bbr_delack_time, 100000,
1616 	    "BBR's delayed ack time");
1617 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1618 	    SYSCTL_CHILDREN(bbr_timeout),
1619 	    OID_AUTO, "tlp_uses", CTLFLAG_RW,
1620 	    &bbr_tlp_type_to_use, 3,
1621 	    "RTT that TLP uses in its calculations, 0=rttProp, 1=Rack_rtt, 2=pkt_rtt and 3=srtt");
1622 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1623 	    SYSCTL_CHILDREN(bbr_timeout),
1624 	    OID_AUTO, "persmin", CTLFLAG_RW,
1625 	    &bbr_persist_min, 250000,
1626 	    "What is the minimum time in microseconds between persists");
1627 	SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1628 	    SYSCTL_CHILDREN(bbr_timeout),
1629 	    OID_AUTO, "persmax", CTLFLAG_RW,
1630 	    &bbr_persist_max, 1000000,
1631 	    "What is the largest delay in microseconds between persists");
1632 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1633 	    SYSCTL_CHILDREN(bbr_timeout),
1634 	    OID_AUTO, "tlp_minto", CTLFLAG_RW,
1635 	    &bbr_tlp_min, 10000,
1636 	    "TLP Min timeout in usecs");
1637 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1638 	    SYSCTL_CHILDREN(bbr_timeout),
1639 	    OID_AUTO, "tlp_dack_time", CTLFLAG_RW,
1640 	    &bbr_delayed_ack_time, 200000,
1641 	    "TLP delayed ack compensation value");
1642 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1643 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1644 	    OID_AUTO, "minrto", CTLFLAG_RW,
1645 	    &bbr_rto_min_ms, 30,
1646 	    "Minimum RTO in ms");
1647 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1648 	    SYSCTL_CHILDREN(bbr_timeout),
1649 	    OID_AUTO, "maxrto", CTLFLAG_RW,
1650 	    &bbr_rto_max_sec, 4,
1651 	    "Maximum RTO in seconds -- should be at least as large as min_rto");
1652 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1653 	    SYSCTL_CHILDREN(bbr_timeout),
1654 	    OID_AUTO, "tlp_retry", CTLFLAG_RW,
1655 	    &bbr_tlp_max_resend, 2,
1656 	    "How many times does TLP retry a single segment or multiple with no ACK");
1657 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1658 	    SYSCTL_CHILDREN(bbr_timeout),
1659 	    OID_AUTO, "minto", CTLFLAG_RW,
1660 	    &bbr_min_to, 1000,
1661 	    "Minimum rack timeout in useconds");
1662 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1663 	    SYSCTL_CHILDREN(bbr_timeout),
1664 	    OID_AUTO, "pktdelay", CTLFLAG_RW,
1665 	    &bbr_pkt_delay, 1000,
1666 	    "Extra RACK time (in useconds) besides reordering thresh");
1667 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1668 	    SYSCTL_CHILDREN(bbr_timeout),
1669 	    OID_AUTO, "incr_tmrs", CTLFLAG_RW,
1670 	    &bbr_incr_timers, 1,
1671 	    "Increase the RXT/TLP timer by the pacing time used?");
1672 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1673 	    SYSCTL_CHILDREN(bbr_timeout),
1674 	    OID_AUTO, "rxtmark_sackpassed", CTLFLAG_RW,
1675 	    &bbr_marks_rxt_sack_passed, 0,
1676 	    "Mark sack passed on all those not ack'd when a RXT hits?");
1677 	/* Policer controls */
1678 	bbr_policer = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1679 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1680 	    OID_AUTO,
1681 	    "policer",
1682 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1683 	    "Policer controls");
1684 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1685 	    SYSCTL_CHILDREN(bbr_policer),
1686 	    OID_AUTO, "detect_enable", CTLFLAG_RW,
1687 	    &bbr_policer_detection_enabled, 1,
1688 	    "Is policer detection enabled??");
1689 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1690 	    SYSCTL_CHILDREN(bbr_policer),
1691 	    OID_AUTO, "min_pes", CTLFLAG_RW,
1692 	    &bbr_lt_intvl_min_rtts, 4,
1693 	    "Minimum number of PE's?");
1694 	SYSCTL_ADD_U64(&bbr_sysctl_ctx,
1695 	    SYSCTL_CHILDREN(bbr_policer),
1696 	    OID_AUTO, "bwdiff", CTLFLAG_RW,
1697 	    &bbr_lt_bw_diff, (4000/8),
1698 	    "Minimal bw diff?");
1699 	SYSCTL_ADD_U64(&bbr_sysctl_ctx,
1700 	    SYSCTL_CHILDREN(bbr_policer),
1701 	    OID_AUTO, "bwratio", CTLFLAG_RW,
1702 	    &bbr_lt_bw_ratio, 8,
1703 	    "Minimal bw diff?");
1704 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1705 	    SYSCTL_CHILDREN(bbr_policer),
1706 	    OID_AUTO, "from_rack_rxt", CTLFLAG_RW,
1707 	    &bbr_policer_call_from_rack_to, 0,
1708 	    "Do we call the policer detection code from a rack-timeout?");
1709 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1710 	    SYSCTL_CHILDREN(bbr_policer),
1711 	    OID_AUTO, "false_postive", CTLFLAG_RW,
1712 	    &bbr_lt_intvl_fp, 0,
1713 	    "What packet epoch do we do false-positive detection at (0=no)?");
1714 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1715 	    SYSCTL_CHILDREN(bbr_policer),
1716 	    OID_AUTO, "loss_thresh", CTLFLAG_RW,
1717 	    &bbr_lt_loss_thresh, 196,
1718 	    "Loss threshold 196 = 19.6%?");
1719 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1720 	    SYSCTL_CHILDREN(bbr_policer),
1721 	    OID_AUTO, "false_postive_thresh", CTLFLAG_RW,
1722 	    &bbr_lt_fd_thresh, 100,
1723 	    "What percentage is the false detection threshold (150=15.0)?");
1724 	/* All the rest */
1725 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1726 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1727 	    OID_AUTO, "cheat_rxt", CTLFLAG_RW,
1728 	    &bbr_use_rack_resend_cheat, 0,
1729 	    "Do we burst 1ms between sends on retransmissions (like rack)?");
1730 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1731 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1732 	    OID_AUTO, "error_paceout", CTLFLAG_RW,
1733 	    &bbr_error_base_paceout, 10000,
1734 	    "When we hit an error what is the min to pace out in usec's?");
1735 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1736 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1737 	    OID_AUTO, "kill_paceout", CTLFLAG_RW,
1738 	    &bbr_max_net_error_cnt, 10,
1739 	    "When we hit this many errors in a row, kill the session?");
1740 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1741 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1742 	    OID_AUTO, "data_after_close", CTLFLAG_RW,
1743 	    &bbr_ignore_data_after_close, 1,
1744 	    "Do we hold off sending a RST until all pending data is ack'd");
1745 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1746 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1747 	    OID_AUTO, "resend_use_tso", CTLFLAG_RW,
1748 	    &bbr_resends_use_tso, 0,
1749 	    "Can resends use TSO?");
1750 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1751 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1752 	    OID_AUTO, "sblklimit", CTLFLAG_RW,
1753 	    &bbr_sack_block_limit, 128,
1754 	    "When do we start ignoring small sack blocks");
1755 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1756 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1757 	    OID_AUTO, "bb_verbose", CTLFLAG_RW,
1758 	    &bbr_verbose_logging, 0,
1759 	    "Should BBR black box logging be verbose");
1760 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1761 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1762 	    OID_AUTO, "reorder_thresh", CTLFLAG_RW,
1763 	    &bbr_reorder_thresh, 2,
1764 	    "What factor for rack will be added when seeing reordering (shift right)");
1765 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1766 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1767 	    OID_AUTO, "reorder_fade", CTLFLAG_RW,
1768 	    &bbr_reorder_fade, 0,
1769 	    "Does reorder detection fade, if so how many ms (0 means never)");
1770 	SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1771 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1772 	    OID_AUTO, "rtt_tlp_thresh", CTLFLAG_RW,
1773 	    &bbr_tlp_thresh, 1,
1774 	    "what divisor for TLP rtt/retran will be added (1=rtt, 2=1/2 rtt etc)");
1775 	/* Stats and counters */
1776 	/* The pacing counters for hdwr/software can't be in the array */
1777 	bbr_nohdwr_pacing_enobuf = counter_u64_alloc(M_WAITOK);
1778 	bbr_hdwr_pacing_enobuf = counter_u64_alloc(M_WAITOK);
1779 	SYSCTL_ADD_COUNTER_U64(&bbr_sysctl_ctx,
1780 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1781 	    OID_AUTO, "enob_hdwr_pacing", CTLFLAG_RD,
1782 	    &bbr_hdwr_pacing_enobuf,
1783 	    "Total number of enobufs for hardware paced flows");
1784 	SYSCTL_ADD_COUNTER_U64(&bbr_sysctl_ctx,
1785 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1786 	    OID_AUTO, "enob_no_hdwr_pacing", CTLFLAG_RD,
1787 	    &bbr_nohdwr_pacing_enobuf,
1788 	    "Total number of enobufs for non-hardware paced flows");
1789 
1790 	bbr_flows_whdwr_pacing = counter_u64_alloc(M_WAITOK);
1791 	SYSCTL_ADD_COUNTER_U64(&bbr_sysctl_ctx,
1792 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1793 	    OID_AUTO, "hdwr_pacing", CTLFLAG_RD,
1794 	    &bbr_flows_whdwr_pacing,
1795 	    "Total number of hardware paced flows");
1796 	bbr_flows_nohdwr_pacing = counter_u64_alloc(M_WAITOK);
1797 	SYSCTL_ADD_COUNTER_U64(&bbr_sysctl_ctx,
1798 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1799 	    OID_AUTO, "software_pacing", CTLFLAG_RD,
1800 	    &bbr_flows_nohdwr_pacing,
1801 	    "Total number of software paced flows");
1802 	COUNTER_ARRAY_ALLOC(bbr_stat_arry, BBR_STAT_SIZE, M_WAITOK);
1803 	SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
1804 	    OID_AUTO, "stats", CTLFLAG_RD,
1805 	    bbr_stat_arry, BBR_STAT_SIZE, "BBR Stats");
1806 	COUNTER_ARRAY_ALLOC(bbr_opts_arry, BBR_OPTS_SIZE, M_WAITOK);
1807 	SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
1808 	    OID_AUTO, "opts", CTLFLAG_RD,
1809 	    bbr_opts_arry, BBR_OPTS_SIZE, "BBR Option Stats");
1810 	COUNTER_ARRAY_ALLOC(bbr_state_lost, BBR_MAX_STAT, M_WAITOK);
1811 	SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
1812 	    OID_AUTO, "lost", CTLFLAG_RD,
1813 	    bbr_state_lost, BBR_MAX_STAT, "Stats of when losses occur");
1814 	COUNTER_ARRAY_ALLOC(bbr_state_resend, BBR_MAX_STAT, M_WAITOK);
1815 	SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
1816 	    OID_AUTO, "stateresend", CTLFLAG_RD,
1817 	    bbr_state_resend, BBR_MAX_STAT, "Stats of what states resend");
1818 	COUNTER_ARRAY_ALLOC(bbr_state_time, BBR_MAX_STAT, M_WAITOK);
1819 	SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
1820 	    OID_AUTO, "statetime", CTLFLAG_RD,
1821 	    bbr_state_time, BBR_MAX_STAT, "Stats of time spent in the states");
1822 	COUNTER_ARRAY_ALLOC(bbr_out_size, TCP_MSS_ACCT_SIZE, M_WAITOK);
1823 	SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
1824 	    OID_AUTO, "outsize", CTLFLAG_RD,
1825 	    bbr_out_size, TCP_MSS_ACCT_SIZE, "Size of output calls");
1826 	SYSCTL_ADD_PROC(&bbr_sysctl_ctx,
1827 	    SYSCTL_CHILDREN(bbr_sysctl_root),
1828 	    OID_AUTO, "clrlost", CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE,
1829 	    &bbr_clear_lost, 0, sysctl_bbr_clear_lost, "IU", "Clear lost counters");
1830 }
1831 
1832 static void
1833 bbr_counter_destroy(void)
1834 {
1835 	COUNTER_ARRAY_FREE(bbr_stat_arry, BBR_STAT_SIZE);
1836 	COUNTER_ARRAY_FREE(bbr_opts_arry, BBR_OPTS_SIZE);
1837 	COUNTER_ARRAY_FREE(bbr_out_size, TCP_MSS_ACCT_SIZE);
1838 	COUNTER_ARRAY_FREE(bbr_state_lost, BBR_MAX_STAT);
1839 	COUNTER_ARRAY_FREE(bbr_state_time, BBR_MAX_STAT);
1840 	COUNTER_ARRAY_FREE(bbr_state_resend, BBR_MAX_STAT);
1841 	counter_u64_free(bbr_nohdwr_pacing_enobuf);
1842 	counter_u64_free(bbr_hdwr_pacing_enobuf);
1843 	counter_u64_free(bbr_flows_whdwr_pacing);
1844 	counter_u64_free(bbr_flows_nohdwr_pacing);
1845 
1846 }
1847 
1848 static __inline void
1849 bbr_fill_in_logging_data(struct tcp_bbr *bbr, struct tcp_log_bbr *l, uint32_t cts)
1850 {
1851 	memset(l, 0, sizeof(union tcp_log_stackspecific));
1852 	l->cur_del_rate = bbr->r_ctl.rc_bbr_cur_del_rate;
1853 	l->delRate = get_filter_value(&bbr->r_ctl.rc_delrate);
1854 	l->rttProp = get_filter_value_small(&bbr->r_ctl.rc_rttprop);
1855 	l->bw_inuse = bbr_get_bw(bbr);
1856 	l->inflight = ctf_flight_size(bbr->rc_tp,
1857 			  (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
1858 	l->applimited = bbr->r_ctl.r_app_limited_until;
1859 	l->delivered = bbr->r_ctl.rc_delivered;
1860 	l->timeStamp = cts;
1861 	l->lost = bbr->r_ctl.rc_lost;
1862 	l->bbr_state = bbr->rc_bbr_state;
1863 	l->bbr_substate = bbr_state_val(bbr);
1864 	l->epoch = bbr->r_ctl.rc_rtt_epoch;
1865 	l->lt_epoch = bbr->r_ctl.rc_lt_epoch;
1866 	l->pacing_gain = bbr->r_ctl.rc_bbr_hptsi_gain;
1867 	l->cwnd_gain = bbr->r_ctl.rc_bbr_cwnd_gain;
1868 	l->inhpts = tcp_in_hpts(bbr->rc_tp);
1869 	l->use_lt_bw = bbr->rc_lt_use_bw;
1870 	l->pkts_out = bbr->r_ctl.rc_flight_at_input;
1871 	l->pkt_epoch = bbr->r_ctl.rc_pkt_epoch;
1872 }
1873 
1874 static void
1875 bbr_log_type_bw_reduce(struct tcp_bbr *bbr, int reason)
1876 {
1877 	if (tcp_bblogging_on(bbr->rc_tp)) {
1878 		union tcp_log_stackspecific log;
1879 
1880 		bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
1881 		log.u_bbr.flex1 = 0;
1882 		log.u_bbr.flex2 = 0;
1883 		log.u_bbr.flex5 = 0;
1884 		log.u_bbr.flex3 = 0;
1885 		log.u_bbr.flex4 = bbr->r_ctl.rc_pkt_epoch_loss_rate;
1886 		log.u_bbr.flex7 = reason;
1887 		log.u_bbr.flex6 = bbr->r_ctl.rc_bbr_enters_probertt;
1888 		log.u_bbr.flex8 = 0;
1889 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
1890 		    &bbr->rc_inp->inp_socket->so_rcv,
1891 		    &bbr->rc_inp->inp_socket->so_snd,
1892 		    BBR_LOG_BW_RED_EV, 0,
1893 		    0, &log, false, &bbr->rc_tv);
1894 	}
1895 }
1896 
1897 static void
1898 bbr_log_type_rwnd_collapse(struct tcp_bbr *bbr, int seq, int mode, uint32_t count)
1899 {
1900 	if (tcp_bblogging_on(bbr->rc_tp)) {
1901 		union tcp_log_stackspecific log;
1902 
1903 		bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
1904 		log.u_bbr.flex1 = seq;
1905 		log.u_bbr.flex2 = count;
1906 		log.u_bbr.flex8 = mode;
1907 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
1908 		    &bbr->rc_inp->inp_socket->so_rcv,
1909 		    &bbr->rc_inp->inp_socket->so_snd,
1910 		    BBR_LOG_LOWGAIN, 0,
1911 		    0, &log, false, &bbr->rc_tv);
1912 	}
1913 }
1914 
1915 static void
1916 bbr_log_type_just_return(struct tcp_bbr *bbr, uint32_t cts, uint32_t tlen, uint8_t hpts_calling,
1917     uint8_t reason, uint32_t p_maxseg, int len)
1918 {
1919 	if (tcp_bblogging_on(bbr->rc_tp)) {
1920 		union tcp_log_stackspecific log;
1921 
1922 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
1923 		log.u_bbr.flex1 = p_maxseg;
1924 		log.u_bbr.flex2 = bbr->r_ctl.rc_hpts_flags;
1925 		log.u_bbr.flex3 = bbr->r_ctl.rc_timer_exp;
1926 		log.u_bbr.flex4 = reason;
1927 		log.u_bbr.flex5 = bbr->rc_in_persist;
1928 		log.u_bbr.flex6 = bbr->r_ctl.rc_last_delay_val;
1929 		log.u_bbr.flex7 = p_maxseg;
1930 		log.u_bbr.flex8 = bbr->rc_in_persist;
1931 		log.u_bbr.pkts_out = 0;
1932 		log.u_bbr.applimited = len;
1933 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
1934 		    &bbr->rc_inp->inp_socket->so_rcv,
1935 		    &bbr->rc_inp->inp_socket->so_snd,
1936 		    BBR_LOG_JUSTRET, 0,
1937 		    tlen, &log, false, &bbr->rc_tv);
1938 	}
1939 }
1940 
1941 static void
1942 bbr_log_type_enter_rec(struct tcp_bbr *bbr, uint32_t seq)
1943 {
1944 	if (tcp_bblogging_on(bbr->rc_tp)) {
1945 		union tcp_log_stackspecific log;
1946 
1947 		bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
1948 		log.u_bbr.flex1 = seq;
1949 		log.u_bbr.flex2 = bbr->r_ctl.rc_cwnd_on_ent;
1950 		log.u_bbr.flex3 = bbr->r_ctl.rc_recovery_start;
1951 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
1952 		    &bbr->rc_inp->inp_socket->so_rcv,
1953 		    &bbr->rc_inp->inp_socket->so_snd,
1954 		    BBR_LOG_ENTREC, 0,
1955 		    0, &log, false, &bbr->rc_tv);
1956 	}
1957 }
1958 
1959 static void
1960 bbr_log_msgsize_fail(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t len, uint32_t maxseg, uint32_t mtu, int32_t csum_flags, int32_t tso, uint32_t cts)
1961 {
1962 	if (tcp_bblogging_on(tp)) {
1963 		union tcp_log_stackspecific log;
1964 
1965 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
1966 		log.u_bbr.flex1 = tso;
1967 		log.u_bbr.flex2 = maxseg;
1968 		log.u_bbr.flex3 = mtu;
1969 		log.u_bbr.flex4 = csum_flags;
1970 		TCP_LOG_EVENTP(tp, NULL,
1971 		    &bbr->rc_inp->inp_socket->so_rcv,
1972 		    &bbr->rc_inp->inp_socket->so_snd,
1973 		    BBR_LOG_MSGSIZE, 0,
1974 		    0, &log, false, &bbr->rc_tv);
1975 	}
1976 }
1977 
1978 static void
1979 bbr_log_flowend(struct tcp_bbr *bbr)
1980 {
1981 	if (tcp_bblogging_on(bbr->rc_tp)) {
1982 		union tcp_log_stackspecific log;
1983 		struct sockbuf *r, *s;
1984 		struct timeval tv;
1985 
1986 		if (bbr->rc_inp->inp_socket) {
1987 			r = &bbr->rc_inp->inp_socket->so_rcv;
1988 			s = &bbr->rc_inp->inp_socket->so_snd;
1989 		} else {
1990 			r = s = NULL;
1991 		}
1992 		bbr_fill_in_logging_data(bbr, &log.u_bbr, tcp_get_usecs(&tv));
1993 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
1994 		    r, s,
1995 		    TCP_LOG_FLOWEND, 0,
1996 		    0, &log, false, &tv);
1997 	}
1998 }
1999 
2000 static void
2001 bbr_log_pkt_epoch(struct tcp_bbr *bbr, uint32_t cts, uint32_t line,
2002     uint32_t lost, uint32_t del)
2003 {
2004 	if (tcp_bblogging_on(bbr->rc_tp)) {
2005 		union tcp_log_stackspecific log;
2006 
2007 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2008 		log.u_bbr.flex1 = lost;
2009 		log.u_bbr.flex2 = del;
2010 		log.u_bbr.flex3 = bbr->r_ctl.rc_bbr_lastbtlbw;
2011 		log.u_bbr.flex4 = bbr->r_ctl.rc_pkt_epoch_rtt;
2012 		log.u_bbr.flex5 = bbr->r_ctl.rc_bbr_last_startup_epoch;
2013 		log.u_bbr.flex6 = bbr->r_ctl.rc_lost_at_startup;
2014 		log.u_bbr.flex7 = line;
2015 		log.u_bbr.flex8 = 0;
2016 		log.u_bbr.inflight = bbr->r_ctl.r_measurement_count;
2017 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2018 		    &bbr->rc_inp->inp_socket->so_rcv,
2019 		    &bbr->rc_inp->inp_socket->so_snd,
2020 		    BBR_LOG_PKT_EPOCH, 0,
2021 		    0, &log, false, &bbr->rc_tv);
2022 	}
2023 }
2024 
2025 static void
2026 bbr_log_time_epoch(struct tcp_bbr *bbr, uint32_t cts, uint32_t line, uint32_t epoch_time)
2027 {
2028 	if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2029 		union tcp_log_stackspecific log;
2030 
2031 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2032 		log.u_bbr.flex1 = bbr->r_ctl.rc_lost;
2033 		log.u_bbr.flex2 = bbr->rc_inp->inp_socket->so_snd.sb_lowat;
2034 		log.u_bbr.flex3 = bbr->rc_inp->inp_socket->so_snd.sb_hiwat;
2035 		log.u_bbr.flex7 = line;
2036 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2037 		    &bbr->rc_inp->inp_socket->so_rcv,
2038 		    &bbr->rc_inp->inp_socket->so_snd,
2039 		    BBR_LOG_TIME_EPOCH, 0,
2040 		    0, &log, false, &bbr->rc_tv);
2041 	}
2042 }
2043 
2044 static void
2045 bbr_log_set_of_state_target(struct tcp_bbr *bbr, uint32_t new_tar, int line, int meth)
2046 {
2047 	if (tcp_bblogging_on(bbr->rc_tp)) {
2048 		union tcp_log_stackspecific log;
2049 
2050 		bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2051 		log.u_bbr.flex1 = bbr->r_ctl.rc_target_at_state;
2052 		log.u_bbr.flex2 = new_tar;
2053 		log.u_bbr.flex3 = line;
2054 		log.u_bbr.flex4 = bbr->r_ctl.rc_pace_max_segs;
2055 		log.u_bbr.flex5 = bbr_quanta;
2056 		log.u_bbr.flex6 = bbr->r_ctl.rc_pace_min_segs;
2057 		log.u_bbr.flex7 = bbr->rc_last_options;
2058 		log.u_bbr.flex8 = meth;
2059 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2060 		    &bbr->rc_inp->inp_socket->so_rcv,
2061 		    &bbr->rc_inp->inp_socket->so_snd,
2062 		    BBR_LOG_STATE_TARGET, 0,
2063 		    0, &log, false, &bbr->rc_tv);
2064 	}
2065 
2066 }
2067 
2068 static void
2069 bbr_log_type_statechange(struct tcp_bbr *bbr, uint32_t cts, int32_t line)
2070 {
2071 	if (tcp_bblogging_on(bbr->rc_tp)) {
2072 		union tcp_log_stackspecific log;
2073 
2074 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2075 		log.u_bbr.flex1 = line;
2076 		log.u_bbr.flex2 = bbr->r_ctl.rc_rtt_shrinks;
2077 		log.u_bbr.flex3 = bbr->r_ctl.rc_probertt_int;
2078 		if (bbr_state_is_pkt_epoch)
2079 			log.u_bbr.flex4 = bbr_get_rtt(bbr, BBR_RTT_PKTRTT);
2080 		else
2081 			log.u_bbr.flex4 = bbr_get_rtt(bbr, BBR_RTT_PROP);
2082 		log.u_bbr.flex5 = bbr->r_ctl.rc_bbr_last_startup_epoch;
2083 		log.u_bbr.flex6 = bbr->r_ctl.rc_lost_at_startup;
2084 		log.u_bbr.flex7 = (bbr->r_ctl.rc_target_at_state/1000);
2085 		log.u_bbr.lt_epoch = bbr->r_ctl.rc_level_state_extra;
2086 		log.u_bbr.pkts_out = bbr->r_ctl.rc_target_at_state;
2087 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2088 		    &bbr->rc_inp->inp_socket->so_rcv,
2089 		    &bbr->rc_inp->inp_socket->so_snd,
2090 		    BBR_LOG_STATE, 0,
2091 		    0, &log, false, &bbr->rc_tv);
2092 	}
2093 }
2094 
2095 static void
2096 bbr_log_rtt_shrinks(struct tcp_bbr *bbr, uint32_t cts, uint32_t applied,
2097 		    uint32_t rtt, uint32_t line, uint8_t reas, uint16_t cond)
2098 {
2099 	if (tcp_bblogging_on(bbr->rc_tp)) {
2100 		union tcp_log_stackspecific log;
2101 
2102 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2103 		log.u_bbr.flex1 = line;
2104 		log.u_bbr.flex2 = bbr->r_ctl.rc_rtt_shrinks;
2105 		log.u_bbr.flex3 = bbr->r_ctl.last_in_probertt;
2106 		log.u_bbr.flex4 = applied;
2107 		log.u_bbr.flex5 = rtt;
2108 		log.u_bbr.flex6 = bbr->r_ctl.rc_target_at_state;
2109 		log.u_bbr.flex7 = cond;
2110 		log.u_bbr.flex8 = reas;
2111 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2112 		    &bbr->rc_inp->inp_socket->so_rcv,
2113 		    &bbr->rc_inp->inp_socket->so_snd,
2114 		    BBR_LOG_RTT_SHRINKS, 0,
2115 		    0, &log, false, &bbr->rc_tv);
2116 	}
2117 }
2118 
2119 static void
2120 bbr_log_type_exit_rec(struct tcp_bbr *bbr)
2121 {
2122 	if (tcp_bblogging_on(bbr->rc_tp)) {
2123 		union tcp_log_stackspecific log;
2124 
2125 		bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2126 		log.u_bbr.flex1 = bbr->r_ctl.rc_recovery_start;
2127 		log.u_bbr.flex2 = bbr->r_ctl.rc_cwnd_on_ent;
2128 		log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
2129 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2130 		    &bbr->rc_inp->inp_socket->so_rcv,
2131 		    &bbr->rc_inp->inp_socket->so_snd,
2132 		    BBR_LOG_EXITREC, 0,
2133 		    0, &log, false, &bbr->rc_tv);
2134 	}
2135 }
2136 
2137 static void
2138 bbr_log_type_cwndupd(struct tcp_bbr *bbr, uint32_t bytes_this_ack, uint32_t chg,
2139     uint32_t prev_acked, int32_t meth, uint32_t target, uint32_t th_ack, int32_t line)
2140 {
2141 	if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2142 		union tcp_log_stackspecific log;
2143 
2144 		bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2145 		log.u_bbr.flex1 = line;
2146 		log.u_bbr.flex2 = prev_acked;
2147 		log.u_bbr.flex3 = bytes_this_ack;
2148 		log.u_bbr.flex4 = chg;
2149 		log.u_bbr.flex5 = th_ack;
2150 		log.u_bbr.flex6 = target;
2151 		log.u_bbr.flex8 = meth;
2152 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2153 		    &bbr->rc_inp->inp_socket->so_rcv,
2154 		    &bbr->rc_inp->inp_socket->so_snd,
2155 		    BBR_LOG_CWND, 0,
2156 		    0, &log, false, &bbr->rc_tv);
2157 	}
2158 }
2159 
2160 static void
2161 bbr_log_rtt_sample(struct tcp_bbr *bbr, uint32_t rtt, uint32_t tsin)
2162 {
2163 	/*
2164 	 * Log the rtt sample we are applying to the srtt algorithm in
2165 	 * useconds.
2166 	 */
2167 	if (tcp_bblogging_on(bbr->rc_tp)) {
2168 		union tcp_log_stackspecific log;
2169 
2170 		bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2171 		log.u_bbr.flex1 = rtt;
2172 		log.u_bbr.flex2 = bbr->r_ctl.rc_bbr_state_time;
2173 		log.u_bbr.flex3 = bbr->r_ctl.rc_ack_hdwr_delay;
2174 		log.u_bbr.flex4 = bbr->rc_tp->ts_offset;
2175 		log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
2176 		log.u_bbr.pkts_out = tcp_tv_to_mssectick(&bbr->rc_tv);
2177 		log.u_bbr.flex6 = tsin;
2178 		log.u_bbr.flex7 = 0;
2179 		log.u_bbr.flex8 = bbr->rc_ack_was_delayed;
2180 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2181 		    &bbr->rc_inp->inp_socket->so_rcv,
2182 		    &bbr->rc_inp->inp_socket->so_snd,
2183 		    TCP_LOG_RTT, 0,
2184 		    0, &log, false, &bbr->rc_tv);
2185 	}
2186 }
2187 
2188 static void
2189 bbr_log_type_pesist(struct tcp_bbr *bbr, uint32_t cts, uint32_t time_in, int32_t line, uint8_t enter_exit)
2190 {
2191 	if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2192 		union tcp_log_stackspecific log;
2193 
2194 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2195 		log.u_bbr.flex1 = time_in;
2196 		log.u_bbr.flex2 = line;
2197 		log.u_bbr.flex8 = enter_exit;
2198 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2199 		    &bbr->rc_inp->inp_socket->so_rcv,
2200 		    &bbr->rc_inp->inp_socket->so_snd,
2201 		    BBR_LOG_PERSIST, 0,
2202 		    0, &log, false, &bbr->rc_tv);
2203 	}
2204 }
2205 static void
2206 bbr_log_ack_clear(struct tcp_bbr *bbr, uint32_t cts)
2207 {
2208 	if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2209 		union tcp_log_stackspecific log;
2210 
2211 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2212 		log.u_bbr.flex1 = bbr->rc_tp->ts_recent_age;
2213 		log.u_bbr.flex2 = bbr->r_ctl.rc_rtt_shrinks;
2214 		log.u_bbr.flex3 = bbr->r_ctl.rc_probertt_int;
2215 		log.u_bbr.flex4 = bbr->r_ctl.rc_went_idle_time;
2216 		log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
2217 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2218 		    &bbr->rc_inp->inp_socket->so_rcv,
2219 		    &bbr->rc_inp->inp_socket->so_snd,
2220 		    BBR_LOG_ACKCLEAR, 0,
2221 		    0, &log, false, &bbr->rc_tv);
2222 	}
2223 }
2224 
2225 static void
2226 bbr_log_ack_event(struct tcp_bbr *bbr, struct tcphdr *th, struct tcpopt *to, uint32_t tlen,
2227 		  uint16_t nsegs, uint32_t cts, int32_t nxt_pkt, struct mbuf *m)
2228 {
2229 	if (tcp_bblogging_on(bbr->rc_tp)) {
2230 		union tcp_log_stackspecific log;
2231 		struct timeval tv;
2232 
2233 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2234 		log.u_bbr.flex1 = nsegs;
2235 		log.u_bbr.flex2 = bbr->r_ctl.rc_lost_bytes;
2236 		if (m) {
2237 			struct timespec ts;
2238 
2239 			log.u_bbr.flex3 = m->m_flags;
2240 			if (m->m_flags & M_TSTMP) {
2241 				mbuf_tstmp2timespec(m, &ts);
2242 				tv.tv_sec = ts.tv_sec;
2243 				tv.tv_usec = ts.tv_nsec / 1000;
2244 				log.u_bbr.lt_epoch = tcp_tv_to_usectick(&tv);
2245 			} else {
2246 				log.u_bbr.lt_epoch = 0;
2247 			}
2248 			if (m->m_flags & M_TSTMP_LRO) {
2249 				mbuf_tstmp2timeval(m, &tv);
2250 				log.u_bbr.flex5 = tcp_tv_to_usectick(&tv);
2251 			} else {
2252 				/* No arrival timestamp */
2253 				log.u_bbr.flex5 = 0;
2254 			}
2255 
2256 			log.u_bbr.pkts_out = tcp_get_usecs(&tv);
2257 		} else {
2258 			log.u_bbr.flex3 = 0;
2259 			log.u_bbr.flex5 = 0;
2260 			log.u_bbr.flex6 = 0;
2261 			log.u_bbr.pkts_out = 0;
2262 		}
2263 		log.u_bbr.flex4 = bbr->r_ctl.rc_target_at_state;
2264 		log.u_bbr.flex7 = bbr->r_wanted_output;
2265 		log.u_bbr.flex8 = bbr->rc_in_persist;
2266 		TCP_LOG_EVENTP(bbr->rc_tp, th,
2267 		    &bbr->rc_inp->inp_socket->so_rcv,
2268 		    &bbr->rc_inp->inp_socket->so_snd,
2269 		    TCP_LOG_IN, 0,
2270 		    tlen, &log, true, &bbr->rc_tv);
2271 	}
2272 }
2273 
2274 static void
2275 bbr_log_doseg_done(struct tcp_bbr *bbr, uint32_t cts, int32_t nxt_pkt, int32_t did_out)
2276 {
2277 	if (tcp_bblogging_on(bbr->rc_tp)) {
2278 		union tcp_log_stackspecific log;
2279 
2280 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2281 		log.u_bbr.flex1 = did_out;
2282 		log.u_bbr.flex2 = nxt_pkt;
2283 		log.u_bbr.flex3 = bbr->r_ctl.rc_last_delay_val;
2284 		log.u_bbr.flex4 = bbr->r_ctl.rc_hpts_flags;
2285 		log.u_bbr.flex5 = bbr->r_ctl.rc_timer_exp;
2286 		log.u_bbr.flex6 = bbr->r_ctl.rc_lost_bytes;
2287 		log.u_bbr.flex7 = bbr->r_wanted_output;
2288 		log.u_bbr.flex8 = bbr->rc_in_persist;
2289 		log.u_bbr.pkts_out = bbr->r_ctl.highest_hdwr_delay;
2290 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2291 		    &bbr->rc_inp->inp_socket->so_rcv,
2292 		    &bbr->rc_inp->inp_socket->so_snd,
2293 		    BBR_LOG_DOSEG_DONE, 0,
2294 		    0, &log, true, &bbr->rc_tv);
2295 	}
2296 }
2297 
2298 static void
2299 bbr_log_enobuf_jmp(struct tcp_bbr *bbr, uint32_t len, uint32_t cts,
2300     int32_t line, uint32_t o_len, uint32_t segcnt, uint32_t segsiz)
2301 {
2302 	if (tcp_bblogging_on(bbr->rc_tp)) {
2303 		union tcp_log_stackspecific log;
2304 
2305 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2306 		log.u_bbr.flex1 = line;
2307 		log.u_bbr.flex2 = o_len;
2308 		log.u_bbr.flex3 = segcnt;
2309 		log.u_bbr.flex4 = segsiz;
2310 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2311 		    &bbr->rc_inp->inp_socket->so_rcv,
2312 		    &bbr->rc_inp->inp_socket->so_snd,
2313 		    BBR_LOG_ENOBUF_JMP, ENOBUFS,
2314 		    len, &log, true, &bbr->rc_tv);
2315 	}
2316 }
2317 
2318 static void
2319 bbr_log_to_processing(struct tcp_bbr *bbr, uint32_t cts, int32_t ret, int32_t timers, uint8_t hpts_calling)
2320 {
2321 	if (tcp_bblogging_on(bbr->rc_tp)) {
2322 		union tcp_log_stackspecific log;
2323 
2324 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2325 		log.u_bbr.flex1 = timers;
2326 		log.u_bbr.flex2 = ret;
2327 		log.u_bbr.flex3 = bbr->r_ctl.rc_timer_exp;
2328 		log.u_bbr.flex4 = bbr->r_ctl.rc_hpts_flags;
2329 		log.u_bbr.flex5 = cts;
2330 		log.u_bbr.flex6 = bbr->r_ctl.rc_target_at_state;
2331 		log.u_bbr.flex8 = hpts_calling;
2332 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2333 		    &bbr->rc_inp->inp_socket->so_rcv,
2334 		    &bbr->rc_inp->inp_socket->so_snd,
2335 		    BBR_LOG_TO_PROCESS, 0,
2336 		    0, &log, false, &bbr->rc_tv);
2337 	}
2338 }
2339 
2340 static void
2341 bbr_log_to_event(struct tcp_bbr *bbr, uint32_t cts, int32_t to_num)
2342 {
2343 	if (tcp_bblogging_on(bbr->rc_tp)) {
2344 		union tcp_log_stackspecific log;
2345 		uint64_t ar;
2346 
2347 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2348 		log.u_bbr.flex1 = bbr->bbr_timer_src;
2349 		log.u_bbr.flex2 = 0;
2350 		log.u_bbr.flex3 = bbr->r_ctl.rc_hpts_flags;
2351 		ar = (uintptr_t)(bbr->r_ctl.rc_resend);
2352 		ar >>= 32;
2353 		ar &= 0x00000000ffffffff;
2354 		log.u_bbr.flex4 = (uint32_t)ar;
2355 		ar = (uintptr_t)bbr->r_ctl.rc_resend;
2356 		ar &= 0x00000000ffffffff;
2357 		log.u_bbr.flex5 = (uint32_t)ar;
2358 		log.u_bbr.flex6 = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
2359 		log.u_bbr.flex8 = to_num;
2360 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2361 		    &bbr->rc_inp->inp_socket->so_rcv,
2362 		    &bbr->rc_inp->inp_socket->so_snd,
2363 		    BBR_LOG_RTO, 0,
2364 		    0, &log, false, &bbr->rc_tv);
2365 	}
2366 }
2367 
2368 static void
2369 bbr_log_startup_event(struct tcp_bbr *bbr, uint32_t cts, uint32_t flex1, uint32_t flex2, uint32_t flex3, uint8_t reason)
2370 {
2371 	if (tcp_bblogging_on(bbr->rc_tp)) {
2372 		union tcp_log_stackspecific log;
2373 
2374 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2375 		log.u_bbr.flex1 = flex1;
2376 		log.u_bbr.flex2 = flex2;
2377 		log.u_bbr.flex3 = flex3;
2378 		log.u_bbr.flex4 = 0;
2379 		log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
2380 		log.u_bbr.flex6 = bbr->r_ctl.rc_lost_at_startup;
2381 		log.u_bbr.flex8 = reason;
2382 		log.u_bbr.cur_del_rate = bbr->r_ctl.rc_bbr_lastbtlbw;
2383 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2384 		    &bbr->rc_inp->inp_socket->so_rcv,
2385 		    &bbr->rc_inp->inp_socket->so_snd,
2386 		    BBR_LOG_REDUCE, 0,
2387 		    0, &log, false, &bbr->rc_tv);
2388 	}
2389 }
2390 
2391 static void
2392 bbr_log_hpts_diag(struct tcp_bbr *bbr, uint32_t cts, struct hpts_diag *diag)
2393 {
2394 	if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2395 		union tcp_log_stackspecific log;
2396 
2397 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2398 		log.u_bbr.flex1 = diag->p_nxt_slot;
2399 		log.u_bbr.flex2 = diag->p_cur_slot;
2400 		log.u_bbr.flex3 = diag->slot_req;
2401 		log.u_bbr.flex4 = diag->inp_hptsslot;
2402 		log.u_bbr.flex5 = diag->slot_remaining;
2403 		log.u_bbr.flex6 = diag->need_new_to;
2404 		log.u_bbr.flex7 = diag->p_hpts_active;
2405 		log.u_bbr.flex8 = diag->p_on_min_sleep;
2406 		/* Hijack other fields as needed  */
2407 		log.u_bbr.epoch = diag->have_slept;
2408 		log.u_bbr.lt_epoch = diag->yet_to_sleep;
2409 		log.u_bbr.pkts_out = diag->co_ret;
2410 		log.u_bbr.applimited = diag->hpts_sleep_time;
2411 		log.u_bbr.delivered = diag->p_prev_slot;
2412 		log.u_bbr.inflight = diag->p_runningslot;
2413 		log.u_bbr.bw_inuse = diag->wheel_slot;
2414 		log.u_bbr.rttProp = diag->wheel_cts;
2415 		log.u_bbr.delRate = diag->maxslots;
2416 		log.u_bbr.cur_del_rate = diag->p_curtick;
2417 		log.u_bbr.cur_del_rate <<= 32;
2418 		log.u_bbr.cur_del_rate |= diag->p_lasttick;
2419 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2420 		    &bbr->rc_inp->inp_socket->so_rcv,
2421 		    &bbr->rc_inp->inp_socket->so_snd,
2422 		    BBR_LOG_HPTSDIAG, 0,
2423 		    0, &log, false, &bbr->rc_tv);
2424 	}
2425 }
2426 
2427 static void
2428 bbr_log_timer_var(struct tcp_bbr *bbr, int mode, uint32_t cts, uint32_t time_since_sent, uint32_t srtt,
2429     uint32_t thresh, uint32_t to)
2430 {
2431 	if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2432 		union tcp_log_stackspecific log;
2433 
2434 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2435 		log.u_bbr.flex1 = bbr->rc_tp->t_rttvar;
2436 		log.u_bbr.flex2 = time_since_sent;
2437 		log.u_bbr.flex3 = srtt;
2438 		log.u_bbr.flex4 = thresh;
2439 		log.u_bbr.flex5 = to;
2440 		log.u_bbr.flex6 = bbr->rc_tp->t_srtt;
2441 		log.u_bbr.flex8 = mode;
2442 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2443 		    &bbr->rc_inp->inp_socket->so_rcv,
2444 		    &bbr->rc_inp->inp_socket->so_snd,
2445 		    BBR_LOG_TIMERPREP, 0,
2446 		    0, &log, false, &bbr->rc_tv);
2447 	}
2448 }
2449 
2450 static void
2451 bbr_log_pacing_delay_calc(struct tcp_bbr *bbr, uint16_t gain, uint32_t len,
2452     uint32_t cts, uint32_t usecs, uint64_t bw, uint32_t override, int mod)
2453 {
2454 	if (tcp_bblogging_on(bbr->rc_tp)) {
2455 		union tcp_log_stackspecific log;
2456 
2457 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2458 		log.u_bbr.flex1 = usecs;
2459 		log.u_bbr.flex2 = len;
2460 		log.u_bbr.flex3 = (uint32_t)((bw >> 32) & 0x00000000ffffffff);
2461 		log.u_bbr.flex4 = (uint32_t)(bw & 0x00000000ffffffff);
2462 		if (override)
2463 			log.u_bbr.flex5 = (1 << 2);
2464 		else
2465 			log.u_bbr.flex5 = 0;
2466 		log.u_bbr.flex6 = override;
2467 		log.u_bbr.flex7 = gain;
2468 		log.u_bbr.flex8 = mod;
2469 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2470 		    &bbr->rc_inp->inp_socket->so_rcv,
2471 		    &bbr->rc_inp->inp_socket->so_snd,
2472 		    BBR_LOG_HPTSI_CALC, 0,
2473 		    len, &log, false, &bbr->rc_tv);
2474 	}
2475 }
2476 
2477 static void
2478 bbr_log_to_start(struct tcp_bbr *bbr, uint32_t cts, uint32_t to, int32_t slot, uint8_t which)
2479 {
2480 	if (tcp_bblogging_on(bbr->rc_tp)) {
2481 		union tcp_log_stackspecific log;
2482 
2483 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2484 
2485 		log.u_bbr.flex1 = bbr->bbr_timer_src;
2486 		log.u_bbr.flex2 = to;
2487 		log.u_bbr.flex3 = bbr->r_ctl.rc_hpts_flags;
2488 		log.u_bbr.flex4 = slot;
2489 		log.u_bbr.flex5 = bbr->rc_tp->t_hpts_slot;
2490 		log.u_bbr.flex6 = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
2491 		log.u_bbr.pkts_out = bbr->rc_tp->t_flags2;
2492 		log.u_bbr.flex8 = which;
2493 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2494 		    &bbr->rc_inp->inp_socket->so_rcv,
2495 		    &bbr->rc_inp->inp_socket->so_snd,
2496 		    BBR_LOG_TIMERSTAR, 0,
2497 		    0, &log, false, &bbr->rc_tv);
2498 	}
2499 }
2500 
2501 static void
2502 bbr_log_thresh_choice(struct tcp_bbr *bbr, uint32_t cts, uint32_t thresh, uint32_t lro, uint32_t srtt, struct bbr_sendmap *rsm, uint8_t frm)
2503 {
2504 	if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2505 		union tcp_log_stackspecific log;
2506 
2507 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2508 		log.u_bbr.flex1 = thresh;
2509 		log.u_bbr.flex2 = lro;
2510 		log.u_bbr.flex3 = bbr->r_ctl.rc_reorder_ts;
2511 		log.u_bbr.flex4 = rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
2512 		log.u_bbr.flex5 = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
2513 		log.u_bbr.flex6 = srtt;
2514 		log.u_bbr.flex7 = bbr->r_ctl.rc_reorder_shift;
2515 		log.u_bbr.flex8 = frm;
2516 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2517 		    &bbr->rc_inp->inp_socket->so_rcv,
2518 		    &bbr->rc_inp->inp_socket->so_snd,
2519 		    BBR_LOG_THRESH_CALC, 0,
2520 		    0, &log, false, &bbr->rc_tv);
2521 	}
2522 }
2523 
2524 static void
2525 bbr_log_to_cancel(struct tcp_bbr *bbr, int32_t line, uint32_t cts, uint8_t hpts_removed)
2526 {
2527 	if (tcp_bblogging_on(bbr->rc_tp)) {
2528 		union tcp_log_stackspecific log;
2529 
2530 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2531 		log.u_bbr.flex1 = line;
2532 		log.u_bbr.flex2 = bbr->bbr_timer_src;
2533 		log.u_bbr.flex3 = bbr->r_ctl.rc_hpts_flags;
2534 		log.u_bbr.flex4 = bbr->rc_in_persist;
2535 		log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
2536 		log.u_bbr.flex6 = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
2537 		log.u_bbr.flex8 = hpts_removed;
2538 		log.u_bbr.pkts_out = bbr->rc_pacer_started;
2539 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2540 		    &bbr->rc_inp->inp_socket->so_rcv,
2541 		    &bbr->rc_inp->inp_socket->so_snd,
2542 		    BBR_LOG_TIMERCANC, 0,
2543 		    0, &log, false, &bbr->rc_tv);
2544 	}
2545 }
2546 
2547 static void
2548 bbr_log_tstmp_validation(struct tcp_bbr *bbr, uint64_t peer_delta, uint64_t delta)
2549 {
2550 	if (tcp_bblogging_on(bbr->rc_tp)) {
2551 		union tcp_log_stackspecific log;
2552 
2553 		bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2554 		log.u_bbr.flex1 = bbr->r_ctl.bbr_peer_tsratio;
2555 		log.u_bbr.flex2 = (peer_delta >> 32);
2556 		log.u_bbr.flex3 = (peer_delta & 0x00000000ffffffff);
2557 		log.u_bbr.flex4 = (delta >> 32);
2558 		log.u_bbr.flex5 = (delta & 0x00000000ffffffff);
2559 		log.u_bbr.flex7 = bbr->rc_ts_clock_set;
2560 		log.u_bbr.flex8 = bbr->rc_ts_cant_be_used;
2561 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2562 		    &bbr->rc_inp->inp_socket->so_rcv,
2563 		    &bbr->rc_inp->inp_socket->so_snd,
2564 		    BBR_LOG_TSTMP_VAL, 0,
2565 		    0, &log, false, &bbr->rc_tv);
2566 	}
2567 }
2568 
2569 static void
2570 bbr_log_type_tsosize(struct tcp_bbr *bbr, uint32_t cts, uint32_t tsosz, uint32_t tls, uint32_t old_val, uint32_t maxseg, int hdwr)
2571 {
2572 	if (tcp_bblogging_on(bbr->rc_tp)) {
2573 		union tcp_log_stackspecific log;
2574 
2575 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2576 		log.u_bbr.flex1 = tsosz;
2577 		log.u_bbr.flex2 = tls;
2578 		log.u_bbr.flex3 = tcp_min_hptsi_time;
2579 		log.u_bbr.flex4 = bbr->r_ctl.bbr_hptsi_bytes_min;
2580 		log.u_bbr.flex5 = old_val;
2581 		log.u_bbr.flex6 = maxseg;
2582 		log.u_bbr.flex7 = bbr->rc_no_pacing;
2583 		log.u_bbr.flex7 <<= 1;
2584 		log.u_bbr.flex7 |= bbr->rc_past_init_win;
2585 		if (hdwr)
2586 			log.u_bbr.flex8 = 0x80 | bbr->rc_use_google;
2587 		else
2588 			log.u_bbr.flex8 = bbr->rc_use_google;
2589 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2590 		    &bbr->rc_inp->inp_socket->so_rcv,
2591 		    &bbr->rc_inp->inp_socket->so_snd,
2592 		    BBR_LOG_BBRTSO, 0,
2593 		    0, &log, false, &bbr->rc_tv);
2594 	}
2595 }
2596 
2597 static void
2598 bbr_log_type_rsmclear(struct tcp_bbr *bbr, uint32_t cts, struct bbr_sendmap *rsm,
2599 		      uint32_t flags, uint32_t line)
2600 {
2601 	if (tcp_bblogging_on(bbr->rc_tp)) {
2602 		union tcp_log_stackspecific log;
2603 
2604 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2605 		log.u_bbr.flex1 = line;
2606 		log.u_bbr.flex2 = rsm->r_start;
2607 		log.u_bbr.flex3 = rsm->r_end;
2608 		log.u_bbr.flex4 = rsm->r_delivered;
2609 		log.u_bbr.flex5 = rsm->r_rtr_cnt;
2610 		log.u_bbr.flex6 = rsm->r_dupack;
2611 		log.u_bbr.flex7 = rsm->r_tim_lastsent[0];
2612 		log.u_bbr.flex8 = rsm->r_flags;
2613 		/* Hijack the pkts_out fids */
2614 		log.u_bbr.applimited = flags;
2615 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2616 		    &bbr->rc_inp->inp_socket->so_rcv,
2617 		    &bbr->rc_inp->inp_socket->so_snd,
2618 		    BBR_RSM_CLEARED, 0,
2619 		    0, &log, false, &bbr->rc_tv);
2620 	}
2621 }
2622 
2623 static void
2624 bbr_log_type_bbrupd(struct tcp_bbr *bbr, uint8_t flex8, uint32_t cts,
2625     uint32_t flex3, uint32_t flex2, uint32_t flex5,
2626     uint32_t flex6, uint32_t pkts_out, int flex7,
2627     uint32_t flex4, uint32_t flex1)
2628 {
2629 
2630 	if (tcp_bblogging_on(bbr->rc_tp)) {
2631 		union tcp_log_stackspecific log;
2632 
2633 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2634 		log.u_bbr.flex1 = flex1;
2635 		log.u_bbr.flex2 = flex2;
2636 		log.u_bbr.flex3 = flex3;
2637 		log.u_bbr.flex4 = flex4;
2638 		log.u_bbr.flex5 = flex5;
2639 		log.u_bbr.flex6 = flex6;
2640 		log.u_bbr.flex7 = flex7;
2641 		/* Hijack the pkts_out fids */
2642 		log.u_bbr.pkts_out = pkts_out;
2643 		log.u_bbr.flex8 = flex8;
2644 		if (bbr->rc_ack_was_delayed)
2645 			log.u_bbr.epoch = bbr->r_ctl.rc_ack_hdwr_delay;
2646 		else
2647 			log.u_bbr.epoch = 0;
2648 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2649 		    &bbr->rc_inp->inp_socket->so_rcv,
2650 		    &bbr->rc_inp->inp_socket->so_snd,
2651 		    BBR_LOG_BBRUPD, 0,
2652 		    flex2, &log, false, &bbr->rc_tv);
2653 	}
2654 }
2655 
2656 static void
2657 bbr_log_type_ltbw(struct tcp_bbr *bbr, uint32_t cts, int32_t reason,
2658 	uint32_t newbw, uint32_t obw, uint32_t diff,
2659 	uint32_t tim)
2660 {
2661 	if (/*bbr_verbose_logging && */tcp_bblogging_on(bbr->rc_tp)) {
2662 		union tcp_log_stackspecific log;
2663 
2664 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2665 		log.u_bbr.flex1 = reason;
2666 		log.u_bbr.flex2 = newbw;
2667 		log.u_bbr.flex3 = obw;
2668 		log.u_bbr.flex4 = diff;
2669 		log.u_bbr.flex5 = bbr->r_ctl.rc_lt_lost;
2670 		log.u_bbr.flex6 = bbr->r_ctl.rc_lt_del;
2671 		log.u_bbr.flex7 = bbr->rc_lt_is_sampling;
2672 		log.u_bbr.pkts_out = tim;
2673 		log.u_bbr.bw_inuse = bbr->r_ctl.rc_lt_bw;
2674 		if (bbr->rc_lt_use_bw == 0)
2675 			log.u_bbr.epoch = bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_lt_epoch;
2676 		else
2677 			log.u_bbr.epoch = bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_lt_epoch_use;
2678 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2679 		    &bbr->rc_inp->inp_socket->so_rcv,
2680 		    &bbr->rc_inp->inp_socket->so_snd,
2681 		    BBR_LOG_BWSAMP, 0,
2682 		    0, &log, false, &bbr->rc_tv);
2683 	}
2684 }
2685 
2686 static inline void
2687 bbr_log_progress_event(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t tick, int event, int line)
2688 {
2689 	if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2690 		union tcp_log_stackspecific log;
2691 
2692 		bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2693 		log.u_bbr.flex1 = line;
2694 		log.u_bbr.flex2 = tick;
2695 		log.u_bbr.flex3 = tp->t_maxunacktime;
2696 		log.u_bbr.flex4 = tp->t_acktime;
2697 		log.u_bbr.flex8 = event;
2698 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2699 		    &bbr->rc_inp->inp_socket->so_rcv,
2700 		    &bbr->rc_inp->inp_socket->so_snd,
2701 		    BBR_LOG_PROGRESS, 0,
2702 		    0, &log, false, &bbr->rc_tv);
2703 	}
2704 }
2705 
2706 static void
2707 bbr_type_log_hdwr_pacing(struct tcp_bbr *bbr, const struct ifnet *ifp,
2708 			 uint64_t rate, uint64_t hw_rate, int line, uint32_t cts,
2709 			 int error)
2710 {
2711 	if (tcp_bblogging_on(bbr->rc_tp)) {
2712 		union tcp_log_stackspecific log;
2713 		uint64_t ifp64 = (uintptr_t)ifp;
2714 
2715 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2716 		log.u_bbr.flex1 = ((hw_rate >> 32) & 0x00000000ffffffff);
2717 		log.u_bbr.flex2 = (hw_rate & 0x00000000ffffffff);
2718 		log.u_bbr.flex3 = ((ifp64  >> 32) & 0x00000000ffffffff);
2719 		log.u_bbr.flex4 = (ifp64 & 0x00000000ffffffff);
2720 		log.u_bbr.bw_inuse = rate;
2721 		log.u_bbr.flex5 = line;
2722 		log.u_bbr.flex6 = error;
2723 		log.u_bbr.flex8 = bbr->skip_gain;
2724 		log.u_bbr.flex8 <<= 1;
2725 		log.u_bbr.flex8 |= bbr->gain_is_limited;
2726 		log.u_bbr.flex8 <<= 1;
2727 		log.u_bbr.flex8 |= bbr->bbr_hdrw_pacing;
2728 		log.u_bbr.pkts_out = bbr->rc_tp->t_maxseg;
2729 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2730 		    &bbr->rc_inp->inp_socket->so_rcv,
2731 		    &bbr->rc_inp->inp_socket->so_snd,
2732 		    BBR_LOG_HDWR_PACE, 0,
2733 		    0, &log, false, &bbr->rc_tv);
2734 	}
2735 }
2736 
2737 static void
2738 bbr_log_type_bbrsnd(struct tcp_bbr *bbr, uint32_t len, uint32_t slot, uint32_t del_by, uint32_t cts, uint32_t line, uint32_t prev_delay)
2739 {
2740 	if (tcp_bblogging_on(bbr->rc_tp)) {
2741 		union tcp_log_stackspecific log;
2742 
2743 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2744 		log.u_bbr.flex1 = slot;
2745 		log.u_bbr.flex2 = del_by;
2746 		log.u_bbr.flex3 = prev_delay;
2747 		log.u_bbr.flex4 = line;
2748 		log.u_bbr.flex5 = bbr->r_ctl.rc_last_delay_val;
2749 		log.u_bbr.flex6 = bbr->r_ctl.rc_hptsi_agg_delay;
2750 		log.u_bbr.flex7 = (0x0000ffff & bbr->r_ctl.rc_hpts_flags);
2751 		log.u_bbr.flex8 = bbr->rc_in_persist;
2752 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2753 		    &bbr->rc_inp->inp_socket->so_rcv,
2754 		    &bbr->rc_inp->inp_socket->so_snd,
2755 		    BBR_LOG_BBRSND, 0,
2756 		    len, &log, false, &bbr->rc_tv);
2757 	}
2758 }
2759 
2760 static void
2761 bbr_log_type_bbrrttprop(struct tcp_bbr *bbr, uint32_t t, uint32_t end, uint32_t tsconv, uint32_t cts, int32_t match, uint32_t seq, uint8_t flags)
2762 {
2763 	if (tcp_bblogging_on(bbr->rc_tp)) {
2764 		union tcp_log_stackspecific log;
2765 
2766 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2767 		log.u_bbr.flex1 = bbr->r_ctl.rc_delivered;
2768 		log.u_bbr.flex2 = 0;
2769 		log.u_bbr.flex3 = bbr->r_ctl.rc_lowest_rtt;
2770 		log.u_bbr.flex4 = end;
2771 		log.u_bbr.flex5 = seq;
2772 		log.u_bbr.flex6 = t;
2773 		log.u_bbr.flex7 = match;
2774 		log.u_bbr.flex8 = flags;
2775 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2776 		    &bbr->rc_inp->inp_socket->so_rcv,
2777 		    &bbr->rc_inp->inp_socket->so_snd,
2778 		    BBR_LOG_BBRRTT, 0,
2779 		    0, &log, false, &bbr->rc_tv);
2780 	}
2781 }
2782 
2783 static void
2784 bbr_log_exit_gain(struct tcp_bbr *bbr, uint32_t cts, int32_t entry_method)
2785 {
2786 	if (tcp_bblogging_on(bbr->rc_tp)) {
2787 		union tcp_log_stackspecific log;
2788 
2789 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2790 		log.u_bbr.flex1 = bbr->r_ctl.rc_target_at_state;
2791 		log.u_bbr.flex2 = (bbr->rc_tp->t_maxseg - bbr->rc_last_options);
2792 		log.u_bbr.flex3 = bbr->r_ctl.gain_epoch;
2793 		log.u_bbr.flex4 = bbr->r_ctl.rc_pace_max_segs;
2794 		log.u_bbr.flex5 = bbr->r_ctl.rc_pace_min_segs;
2795 		log.u_bbr.flex6 = bbr->r_ctl.rc_bbr_state_atflight;
2796 		log.u_bbr.flex7 = 0;
2797 		log.u_bbr.flex8 = entry_method;
2798 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2799 		    &bbr->rc_inp->inp_socket->so_rcv,
2800 		    &bbr->rc_inp->inp_socket->so_snd,
2801 		    BBR_LOG_EXIT_GAIN, 0,
2802 		    0, &log, false, &bbr->rc_tv);
2803 	}
2804 }
2805 
2806 static void
2807 bbr_log_settings_change(struct tcp_bbr *bbr, int settings_desired)
2808 {
2809 	if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2810 		union tcp_log_stackspecific log;
2811 
2812 		bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2813 		/* R-HU */
2814 		log.u_bbr.flex1 = 0;
2815 		log.u_bbr.flex2 = 0;
2816 		log.u_bbr.flex3 = 0;
2817 		log.u_bbr.flex4 = 0;
2818 		log.u_bbr.flex7 = 0;
2819 		log.u_bbr.flex8 = settings_desired;
2820 
2821 		TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2822 		    &bbr->rc_inp->inp_socket->so_rcv,
2823 		    &bbr->rc_inp->inp_socket->so_snd,
2824 		    BBR_LOG_SETTINGS_CHG, 0,
2825 		    0, &log, false, &bbr->rc_tv);
2826 	}
2827 }
2828 
2829 /*
2830  * Returns the bw from the our filter.
2831  */
2832 static inline uint64_t
2833 bbr_get_full_bw(struct tcp_bbr *bbr)
2834 {
2835 	uint64_t bw;
2836 
2837 	bw = get_filter_value(&bbr->r_ctl.rc_delrate);
2838 
2839 	return (bw);
2840 }
2841 
2842 static inline void
2843 bbr_set_pktepoch(struct tcp_bbr *bbr, uint32_t cts, int32_t line)
2844 {
2845 	uint64_t calclr;
2846 	uint32_t lost, del;
2847 
2848 	if (bbr->r_ctl.rc_lost > bbr->r_ctl.rc_lost_at_pktepoch)
2849 		lost = bbr->r_ctl.rc_lost - bbr->r_ctl.rc_lost_at_pktepoch;
2850 	else
2851 		lost = 0;
2852 	del = bbr->r_ctl.rc_delivered - bbr->r_ctl.rc_pkt_epoch_del;
2853 	if (lost == 0)  {
2854 		calclr = 0;
2855 	} else if (del) {
2856 		calclr = lost;
2857 		calclr *= (uint64_t)1000;
2858 		calclr /= (uint64_t)del;
2859 	} else {
2860 		/* Nothing delivered? 100.0% loss */
2861 		calclr = 1000;
2862 	}
2863 	bbr->r_ctl.rc_pkt_epoch_loss_rate =  (uint32_t)calclr;
2864 	if (IN_RECOVERY(bbr->rc_tp->t_flags))
2865 		bbr->r_ctl.recovery_lr += (uint32_t)calclr;
2866 	bbr->r_ctl.rc_pkt_epoch++;
2867 	if (bbr->rc_no_pacing &&
2868 	    (bbr->r_ctl.rc_pkt_epoch >= bbr->no_pacing_until)) {
2869 		bbr->rc_no_pacing = 0;
2870 		tcp_bbr_tso_size_check(bbr, cts);
2871 	}
2872 	bbr->r_ctl.rc_pkt_epoch_rtt = bbr_calc_time(cts, bbr->r_ctl.rc_pkt_epoch_time);
2873 	bbr->r_ctl.rc_pkt_epoch_time = cts;
2874 	/* What was our loss rate */
2875 	bbr_log_pkt_epoch(bbr, cts, line, lost, del);
2876 	bbr->r_ctl.rc_pkt_epoch_del = bbr->r_ctl.rc_delivered;
2877 	bbr->r_ctl.rc_lost_at_pktepoch = bbr->r_ctl.rc_lost;
2878 }
2879 
2880 static inline void
2881 bbr_set_epoch(struct tcp_bbr *bbr, uint32_t cts, int32_t line)
2882 {
2883 	uint32_t epoch_time;
2884 
2885 	/* Tick the RTT clock */
2886 	bbr->r_ctl.rc_rtt_epoch++;
2887 	epoch_time = cts - bbr->r_ctl.rc_rcv_epoch_start;
2888 	bbr_log_time_epoch(bbr, cts, line, epoch_time);
2889 	bbr->r_ctl.rc_rcv_epoch_start = cts;
2890 }
2891 
2892 static inline void
2893 bbr_isit_a_pkt_epoch(struct tcp_bbr *bbr, uint32_t cts, struct bbr_sendmap *rsm, int32_t line, int32_t cum_acked)
2894 {
2895 	if (SEQ_GEQ(rsm->r_delivered, bbr->r_ctl.rc_pkt_epoch_del)) {
2896 		bbr->rc_is_pkt_epoch_now = 1;
2897 	}
2898 }
2899 
2900 /*
2901  * Returns the bw from either the b/w filter
2902  * or from the lt_bw (if the connection is being
2903  * policed).
2904  */
2905 static inline uint64_t
2906 __bbr_get_bw(struct tcp_bbr *bbr)
2907 {
2908 	uint64_t bw, min_bw;
2909 	uint64_t rtt;
2910 	int gm_measure_cnt = 1;
2911 
2912 	/*
2913 	 * For startup we make, like google, a
2914 	 * minimum b/w. This is generated from the
2915 	 * IW and the rttProp. We do fall back to srtt
2916 	 * if for some reason (initial handshake) we don't
2917 	 * have a rttProp. We, in the worst case, fall back
2918 	 * to the configured min_bw (rc_initial_hptsi_bw).
2919 	 */
2920 	if (bbr->rc_bbr_state == BBR_STATE_STARTUP) {
2921 		/* Attempt first to use rttProp */
2922 		rtt = (uint64_t)get_filter_value_small(&bbr->r_ctl.rc_rttprop);
2923 		if (rtt && (rtt < 0xffffffff)) {
2924 measure:
2925 			min_bw = (uint64_t)(bbr_initial_cwnd(bbr, bbr->rc_tp)) *
2926 				((uint64_t)1000000);
2927 			min_bw /= rtt;
2928 			if (min_bw < bbr->r_ctl.rc_initial_hptsi_bw) {
2929 				min_bw = bbr->r_ctl.rc_initial_hptsi_bw;
2930 			}
2931 
2932 		} else if (bbr->rc_tp->t_srtt != 0) {
2933 			/* No rttProp, use srtt? */
2934 			rtt = bbr_get_rtt(bbr, BBR_SRTT);
2935 			goto measure;
2936 		} else {
2937 			min_bw = bbr->r_ctl.rc_initial_hptsi_bw;
2938 		}
2939 	} else
2940 		min_bw = 0;
2941 
2942 	if ((bbr->rc_past_init_win == 0) &&
2943 	    (bbr->r_ctl.rc_delivered > bbr_initial_cwnd(bbr, bbr->rc_tp)))
2944 		bbr->rc_past_init_win = 1;
2945 	if ((bbr->rc_use_google)  && (bbr->r_ctl.r_measurement_count >= 1))
2946 		gm_measure_cnt = 0;
2947 	if (gm_measure_cnt &&
2948 	    ((bbr->r_ctl.r_measurement_count < bbr_min_measurements_req) ||
2949 	     (bbr->rc_past_init_win == 0))) {
2950 		/* For google we use our guess rate until we get 1 measurement */
2951 
2952 use_initial_window:
2953 		rtt = (uint64_t)get_filter_value_small(&bbr->r_ctl.rc_rttprop);
2954 		if (rtt && (rtt < 0xffffffff)) {
2955 			/*
2956 			 * We have an RTT measurement. Use that in
2957 			 * combination with our initial window to calculate
2958 			 * a b/w.
2959 			 */
2960 			bw = (uint64_t)(bbr_initial_cwnd(bbr, bbr->rc_tp)) *
2961 				((uint64_t)1000000);
2962 			bw /= rtt;
2963 			if (bw < bbr->r_ctl.rc_initial_hptsi_bw) {
2964 				bw = bbr->r_ctl.rc_initial_hptsi_bw;
2965 			}
2966 		} else {
2967 			/* Drop back to the 40 and punt to a default */
2968 			bw = bbr->r_ctl.rc_initial_hptsi_bw;
2969 		}
2970 		if (bw < 1)
2971 			/* Probably should panic */
2972 			bw = 1;
2973 		if (bw > min_bw)
2974 			return (bw);
2975 		else
2976 			return (min_bw);
2977 	}
2978 	if (bbr->rc_lt_use_bw)
2979 		bw = bbr->r_ctl.rc_lt_bw;
2980 	else if (bbr->r_recovery_bw && (bbr->rc_use_google == 0))
2981 		bw = bbr->r_ctl.red_bw;
2982 	else
2983 		bw = get_filter_value(&bbr->r_ctl.rc_delrate);
2984 	if (bw == 0) {
2985 		/* We should not be at 0, go to the initial window then  */
2986 		goto use_initial_window;
2987 	}
2988 	if (bw < min_bw)
2989 		bw = min_bw;
2990 	return (bw);
2991 }
2992 
2993 static inline uint64_t
2994 bbr_get_bw(struct tcp_bbr *bbr)
2995 {
2996 	uint64_t bw;
2997 
2998 	bw = __bbr_get_bw(bbr);
2999 	return (bw);
3000 }
3001 
3002 static inline void
3003 bbr_reset_lt_bw_interval(struct tcp_bbr *bbr, uint32_t cts)
3004 {
3005 	bbr->r_ctl.rc_lt_epoch = bbr->r_ctl.rc_pkt_epoch;
3006 	bbr->r_ctl.rc_lt_time = bbr->r_ctl.rc_del_time;
3007 	bbr->r_ctl.rc_lt_del = bbr->r_ctl.rc_delivered;
3008 	bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
3009 }
3010 
3011 static inline void
3012 bbr_reset_lt_bw_sampling(struct tcp_bbr *bbr, uint32_t cts)
3013 {
3014 	bbr->rc_lt_is_sampling = 0;
3015 	bbr->rc_lt_use_bw = 0;
3016 	bbr->r_ctl.rc_lt_bw = 0;
3017 	bbr_reset_lt_bw_interval(bbr, cts);
3018 }
3019 
3020 static inline void
3021 bbr_lt_bw_samp_done(struct tcp_bbr *bbr, uint64_t bw, uint32_t cts, uint32_t timin)
3022 {
3023 	uint64_t diff;
3024 
3025 	/* Do we have a previous sample? */
3026 	if (bbr->r_ctl.rc_lt_bw) {
3027 		/* Get the diff in bytes per second */
3028 		if (bbr->r_ctl.rc_lt_bw > bw)
3029 			diff = bbr->r_ctl.rc_lt_bw - bw;
3030 		else
3031 			diff = bw - bbr->r_ctl.rc_lt_bw;
3032 		if ((diff <= bbr_lt_bw_diff) ||
3033 		    (diff <= (bbr->r_ctl.rc_lt_bw / bbr_lt_bw_ratio))) {
3034 			/* Consider us policed */
3035 			uint32_t saved_bw;
3036 
3037 			saved_bw = (uint32_t)bbr->r_ctl.rc_lt_bw;
3038 			bbr->r_ctl.rc_lt_bw = (bw + bbr->r_ctl.rc_lt_bw) / 2;	/* average of two */
3039 			bbr->rc_lt_use_bw = 1;
3040 			bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
3041 			/*
3042 			 * Use pkt based epoch for measuring length of
3043 			 * policer up
3044 			 */
3045 			bbr->r_ctl.rc_lt_epoch_use = bbr->r_ctl.rc_pkt_epoch;
3046 			/*
3047 			 * reason 4 is we need to start consider being
3048 			 * policed
3049 			 */
3050 			bbr_log_type_ltbw(bbr, cts, 4, (uint32_t)bw, saved_bw, (uint32_t)diff, timin);
3051 			return;
3052 		}
3053 	}
3054 	bbr->r_ctl.rc_lt_bw = bw;
3055 	bbr_reset_lt_bw_interval(bbr, cts);
3056 	bbr_log_type_ltbw(bbr, cts, 5, 0, (uint32_t)bw, 0, timin);
3057 }
3058 
3059 static void
3060 bbr_randomize_extra_state_time(struct tcp_bbr *bbr)
3061 {
3062 	uint32_t ran, deduct;
3063 
3064 	ran = arc4random_uniform(bbr_rand_ot);
3065 	if (ran) {
3066 		deduct = bbr->r_ctl.rc_level_state_extra / ran;
3067 		bbr->r_ctl.rc_level_state_extra -= deduct;
3068 	}
3069 }
3070 /*
3071  * Return randomly the starting state
3072  * to use in probebw.
3073  */
3074 static uint8_t
3075 bbr_pick_probebw_substate(struct tcp_bbr *bbr, uint32_t cts)
3076 {
3077 	uint32_t ran;
3078 	uint8_t ret_val;
3079 
3080 	/* Initialize the offset to 0 */
3081 	bbr->r_ctl.rc_exta_time_gd = 0;
3082 	bbr->rc_hit_state_1 = 0;
3083 	bbr->r_ctl.rc_level_state_extra = 0;
3084 	ran = arc4random_uniform((BBR_SUBSTATE_COUNT-1));
3085 	/*
3086 	 * The math works funny here :) the return value is used to set the
3087 	 * substate and then the state change is called which increments by
3088 	 * one. So if we return 1 (DRAIN) we will increment to 2 (LEVEL1) when
3089 	 * we fully enter the state. Note that the (8 - 1 - ran) assures that
3090 	 * we return 1 - 7, so we dont return 0 and end up starting in
3091 	 * state 1 (DRAIN).
3092 	 */
3093 	ret_val = BBR_SUBSTATE_COUNT - 1 - ran;
3094 	/* Set an epoch */
3095 	if ((cts - bbr->r_ctl.rc_rcv_epoch_start) >= bbr_get_rtt(bbr, BBR_RTT_PROP))
3096 		bbr_set_epoch(bbr, cts, __LINE__);
3097 
3098 	bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
3099 	return (ret_val);
3100 }
3101 
3102 static void
3103 bbr_lt_bw_sampling(struct tcp_bbr *bbr, uint32_t cts, int32_t loss_detected)
3104 {
3105 	uint32_t diff, d_time;
3106 	uint64_t del_time, bw, lost, delivered;
3107 
3108 	if (bbr->r_use_policer == 0)
3109 		return;
3110 	if (bbr->rc_lt_use_bw) {
3111 		/* We are using lt bw do we stop yet? */
3112 		diff = bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_lt_epoch_use;
3113 		if (diff > bbr_lt_bw_max_rtts) {
3114 			/* Reset it all */
3115 reset_all:
3116 			bbr_reset_lt_bw_sampling(bbr, cts);
3117 			if (bbr->rc_filled_pipe) {
3118 				bbr_set_epoch(bbr, cts, __LINE__);
3119 				bbr->rc_bbr_substate = bbr_pick_probebw_substate(bbr, cts);
3120 				bbr_substate_change(bbr, cts, __LINE__, 0);
3121 				bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
3122 				bbr_log_type_statechange(bbr, cts, __LINE__);
3123 			} else {
3124 				/*
3125 				 * This should not happen really
3126 				 * unless we remove the startup/drain
3127 				 * restrictions above.
3128 				 */
3129 				bbr->rc_bbr_state = BBR_STATE_STARTUP;
3130 				bbr_set_epoch(bbr, cts, __LINE__);
3131 				bbr->r_ctl.rc_bbr_state_time = cts;
3132 				bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
3133 				bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.rc_startup_pg;
3134 				bbr->r_ctl.rc_bbr_cwnd_gain = bbr->r_ctl.rc_startup_pg;
3135 				bbr_set_state_target(bbr, __LINE__);
3136 				bbr_log_type_statechange(bbr, cts, __LINE__);
3137 			}
3138 			/* reason 0 is to stop using lt-bw */
3139 			bbr_log_type_ltbw(bbr, cts, 0, 0, 0, 0, 0);
3140 			return;
3141 		}
3142 		if (bbr_lt_intvl_fp == 0) {
3143 			/* Not doing false-positive detection */
3144 			return;
3145 		}
3146 		/* False positive detection */
3147 		if (diff == bbr_lt_intvl_fp) {
3148 			/* At bbr_lt_intvl_fp we record the lost */
3149 			bbr->r_ctl.rc_lt_del = bbr->r_ctl.rc_delivered;
3150 			bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
3151 		} else if (diff > (bbr_lt_intvl_min_rtts + bbr_lt_intvl_fp)) {
3152 			/* Now is our loss rate still high? */
3153 			lost = bbr->r_ctl.rc_lost - bbr->r_ctl.rc_lt_lost;
3154 			delivered = bbr->r_ctl.rc_delivered - bbr->r_ctl.rc_lt_del;
3155 			if ((delivered == 0) ||
3156 			    (((lost * 1000)/delivered) < bbr_lt_fd_thresh)) {
3157 				/* No still below our threshold */
3158 				bbr_log_type_ltbw(bbr, cts, 7, lost, delivered, 0, 0);
3159 			} else {
3160 				/* Yikes its still high, it must be a false positive */
3161 				bbr_log_type_ltbw(bbr, cts, 8, lost, delivered, 0, 0);
3162 				goto reset_all;
3163 			}
3164 		}
3165 		return;
3166 	}
3167 	/*
3168 	 * Wait for the first loss before sampling, to let the policer
3169 	 * exhaust its tokens and estimate the steady-state rate allowed by
3170 	 * the policer. Starting samples earlier includes bursts that
3171 	 * over-estimate the bw.
3172 	 */
3173 	if (bbr->rc_lt_is_sampling == 0) {
3174 		/* reason 1 is to begin doing the sampling  */
3175 		if (loss_detected == 0)
3176 			return;
3177 		bbr_reset_lt_bw_interval(bbr, cts);
3178 		bbr->rc_lt_is_sampling = 1;
3179 		bbr_log_type_ltbw(bbr, cts, 1, 0, 0, 0, 0);
3180 		return;
3181 	}
3182 	/* Now how long were we delivering long term last> */
3183 	if (TSTMP_GEQ(bbr->r_ctl.rc_del_time, bbr->r_ctl.rc_lt_time))
3184 		d_time = bbr->r_ctl.rc_del_time - bbr->r_ctl.rc_lt_time;
3185 	else
3186 		d_time = 0;
3187 
3188 	/* To avoid underestimates, reset sampling if we run out of data. */
3189 	if (bbr->r_ctl.r_app_limited_until) {
3190 		/* Can not measure in app-limited state */
3191 		bbr_reset_lt_bw_sampling(bbr, cts);
3192 		/* reason 2 is to reset sampling due to app limits  */
3193 		bbr_log_type_ltbw(bbr, cts, 2, 0, 0, 0, d_time);
3194 		return;
3195 	}
3196 	diff = bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_lt_epoch;
3197 	if (diff < bbr_lt_intvl_min_rtts) {
3198 		/*
3199 		 * need more samples (we don't
3200 		 * start on a round like linux so
3201 		 * we need 1 more).
3202 		 */
3203 		/* 6 is not_enough time or no-loss */
3204 		bbr_log_type_ltbw(bbr, cts, 6, 0, 0, 0, d_time);
3205 		return;
3206 	}
3207 	if (diff > (4 * bbr_lt_intvl_min_rtts)) {
3208 		/*
3209 		 * For now if we wait too long, reset all sampling. We need
3210 		 * to do some research here, its possible that we should
3211 		 * base this on how much loss as occurred.. something like
3212 		 * if its under 10% (or some thresh) reset all otherwise
3213 		 * don't.  Thats for phase II I guess.
3214 		 */
3215 		bbr_reset_lt_bw_sampling(bbr, cts);
3216  		/* reason 3 is to reset sampling due too long of sampling */
3217 		bbr_log_type_ltbw(bbr, cts, 3, 0, 0, 0, d_time);
3218 		return;
3219 	}
3220 	/*
3221 	 * End sampling interval when a packet is lost, so we estimate the
3222 	 * policer tokens were exhausted. Stopping the sampling before the
3223 	 * tokens are exhausted under-estimates the policed rate.
3224 	 */
3225 	if (loss_detected == 0) {
3226 		/* 6 is not_enough time or no-loss */
3227 		bbr_log_type_ltbw(bbr, cts, 6, 0, 0, 0, d_time);
3228 		return;
3229 	}
3230 	/* Calculate packets lost and delivered in sampling interval. */
3231 	lost = bbr->r_ctl.rc_lost - bbr->r_ctl.rc_lt_lost;
3232 	delivered = bbr->r_ctl.rc_delivered - bbr->r_ctl.rc_lt_del;
3233 	if ((delivered == 0) ||
3234 	    (((lost * 1000)/delivered) < bbr_lt_loss_thresh)) {
3235 		bbr_log_type_ltbw(bbr, cts, 6, lost, delivered, 0, d_time);
3236 		return;
3237 	}
3238 	if (d_time < 1000) {
3239 		/* Not enough time. wait */
3240 		/* 6 is not_enough time or no-loss */
3241 		bbr_log_type_ltbw(bbr, cts, 6, 0, 0, 0, d_time);
3242 		return;
3243 	}
3244 	if (d_time >= (0xffffffff / USECS_IN_MSEC)) {
3245 		/* Too long */
3246 		bbr_reset_lt_bw_sampling(bbr, cts);
3247  		/* reason 3 is to reset sampling due too long of sampling */
3248 		bbr_log_type_ltbw(bbr, cts, 3, 0, 0, 0, d_time);
3249 		return;
3250 	}
3251 	del_time = d_time;
3252 	bw = delivered;
3253 	bw *= (uint64_t)USECS_IN_SECOND;
3254 	bw /= del_time;
3255 	bbr_lt_bw_samp_done(bbr, bw, cts, d_time);
3256 }
3257 
3258 /*
3259  * Allocate a sendmap from our zone.
3260  */
3261 static struct bbr_sendmap *
3262 bbr_alloc(struct tcp_bbr *bbr)
3263 {
3264 	struct bbr_sendmap *rsm;
3265 
3266 	BBR_STAT_INC(bbr_to_alloc);
3267 	rsm = uma_zalloc(bbr_zone, (M_NOWAIT | M_ZERO));
3268 	if (rsm) {
3269 		bbr->r_ctl.rc_num_maps_alloced++;
3270 		return (rsm);
3271 	}
3272 	if (bbr->r_ctl.rc_free_cnt) {
3273 		BBR_STAT_INC(bbr_to_alloc_emerg);
3274 		rsm = TAILQ_FIRST(&bbr->r_ctl.rc_free);
3275 		TAILQ_REMOVE(&bbr->r_ctl.rc_free, rsm, r_next);
3276 		bbr->r_ctl.rc_free_cnt--;
3277 		return (rsm);
3278 	}
3279 	BBR_STAT_INC(bbr_to_alloc_failed);
3280 	return (NULL);
3281 }
3282 
3283 static struct bbr_sendmap *
3284 bbr_alloc_full_limit(struct tcp_bbr *bbr)
3285 {
3286 	if ((V_tcp_map_entries_limit > 0) &&
3287 	    (bbr->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
3288 		BBR_STAT_INC(bbr_alloc_limited);
3289 		if (!bbr->alloc_limit_reported) {
3290 			bbr->alloc_limit_reported = 1;
3291 			BBR_STAT_INC(bbr_alloc_limited_conns);
3292 		}
3293 		return (NULL);
3294 	}
3295 	return (bbr_alloc(bbr));
3296 }
3297 
3298 /* wrapper to allocate a sendmap entry, subject to a specific limit */
3299 static struct bbr_sendmap *
3300 bbr_alloc_limit(struct tcp_bbr *bbr, uint8_t limit_type)
3301 {
3302 	struct bbr_sendmap *rsm;
3303 
3304 	if (limit_type) {
3305 		/* currently there is only one limit type */
3306 		if (V_tcp_map_split_limit > 0 &&
3307 		    bbr->r_ctl.rc_num_split_allocs >= V_tcp_map_split_limit) {
3308 			BBR_STAT_INC(bbr_split_limited);
3309 			if (!bbr->alloc_limit_reported) {
3310 				bbr->alloc_limit_reported = 1;
3311 				BBR_STAT_INC(bbr_alloc_limited_conns);
3312 			}
3313 			return (NULL);
3314 		}
3315 	}
3316 
3317 	/* allocate and mark in the limit type, if set */
3318 	rsm = bbr_alloc(bbr);
3319 	if (rsm != NULL && limit_type) {
3320 		rsm->r_limit_type = limit_type;
3321 		bbr->r_ctl.rc_num_split_allocs++;
3322 	}
3323 	return (rsm);
3324 }
3325 
3326 static void
3327 bbr_free(struct tcp_bbr *bbr, struct bbr_sendmap *rsm)
3328 {
3329 	if (rsm->r_limit_type) {
3330 		/* currently there is only one limit type */
3331 		bbr->r_ctl.rc_num_split_allocs--;
3332 	}
3333 	if (rsm->r_is_smallmap)
3334 		bbr->r_ctl.rc_num_small_maps_alloced--;
3335 	if (bbr->r_ctl.rc_tlp_send == rsm)
3336 		bbr->r_ctl.rc_tlp_send = NULL;
3337 	if (bbr->r_ctl.rc_resend == rsm) {
3338 		bbr->r_ctl.rc_resend = NULL;
3339 	}
3340 	if (bbr->r_ctl.rc_next == rsm)
3341 		bbr->r_ctl.rc_next = NULL;
3342 	if (bbr->r_ctl.rc_sacklast == rsm)
3343 		bbr->r_ctl.rc_sacklast = NULL;
3344 	if (bbr->r_ctl.rc_free_cnt < bbr_min_req_free) {
3345 		memset(rsm, 0, sizeof(struct bbr_sendmap));
3346 		TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_free, rsm, r_next);
3347 		rsm->r_limit_type = 0;
3348 		bbr->r_ctl.rc_free_cnt++;
3349 		return;
3350 	}
3351 	bbr->r_ctl.rc_num_maps_alloced--;
3352 	uma_zfree(bbr_zone, rsm);
3353 }
3354 
3355 /*
3356  * Returns the BDP.
3357  */
3358 static uint64_t
3359 bbr_get_bw_delay_prod(uint64_t rtt, uint64_t bw) {
3360 	/*
3361 	 * Calculate the bytes in flight needed given the bw (in bytes per
3362 	 * second) and the specifyed rtt in useconds. We need to put out the
3363 	 * returned value per RTT to match that rate. Gain will normally
3364 	 * raise it up from there.
3365 	 *
3366 	 * This should not overflow as long as the bandwidth is below 1
3367 	 * TByte per second (bw < 10**12 = 2**40) and the rtt is smaller
3368 	 * than 1000 seconds (rtt < 10**3 * 10**6 = 10**9 = 2**30).
3369 	 */
3370 	uint64_t usec_per_sec;
3371 
3372 	usec_per_sec = USECS_IN_SECOND;
3373 	return ((rtt * bw) / usec_per_sec);
3374 }
3375 
3376 /*
3377  * Return the initial cwnd.
3378  */
3379 static uint32_t
3380 bbr_initial_cwnd(struct tcp_bbr *bbr, struct tcpcb *tp)
3381 {
3382 	uint32_t i_cwnd;
3383 
3384 	if (bbr->rc_init_win) {
3385 		i_cwnd = bbr->rc_init_win * tp->t_maxseg;
3386 	} else if (V_tcp_initcwnd_segments)
3387 		i_cwnd = min((V_tcp_initcwnd_segments * tp->t_maxseg),
3388 		    max(2 * tp->t_maxseg, 14600));
3389 	else if (V_tcp_do_rfc3390)
3390 		i_cwnd = min(4 * tp->t_maxseg,
3391 		    max(2 * tp->t_maxseg, 4380));
3392 	else {
3393 		/* Per RFC5681 Section 3.1 */
3394 		if (tp->t_maxseg > 2190)
3395 			i_cwnd = 2 * tp->t_maxseg;
3396 		else if (tp->t_maxseg > 1095)
3397 			i_cwnd = 3 * tp->t_maxseg;
3398 		else
3399 			i_cwnd = 4 * tp->t_maxseg;
3400 	}
3401 	return (i_cwnd);
3402 }
3403 
3404 /*
3405  * Given a specified gain, return the target
3406  * cwnd based on that gain.
3407  */
3408 static uint32_t
3409 bbr_get_raw_target_cwnd(struct tcp_bbr *bbr, uint32_t gain, uint64_t bw)
3410 {
3411 	uint64_t bdp, rtt;
3412 	uint32_t cwnd;
3413 
3414 	if ((get_filter_value_small(&bbr->r_ctl.rc_rttprop) == 0xffffffff) ||
3415 	    (bbr_get_full_bw(bbr) == 0)) {
3416 		/* No measurements yet */
3417 		return (bbr_initial_cwnd(bbr, bbr->rc_tp));
3418 	}
3419 	/*
3420 	 * Get bytes per RTT needed (rttProp is normally in
3421 	 * bbr_cwndtarget_rtt_touse)
3422 	 */
3423 	rtt = bbr_get_rtt(bbr, bbr_cwndtarget_rtt_touse);
3424 	/* Get the bdp from the two values */
3425 	bdp = bbr_get_bw_delay_prod(rtt, bw);
3426 	/* Now apply the gain */
3427 	cwnd = (uint32_t)(((bdp * ((uint64_t)gain)) + (uint64_t)(BBR_UNIT - 1)) / ((uint64_t)BBR_UNIT));
3428 
3429 	return (cwnd);
3430 }
3431 
3432 static uint32_t
3433 bbr_get_target_cwnd(struct tcp_bbr *bbr, uint64_t bw, uint32_t gain)
3434 {
3435 	uint32_t cwnd, mss;
3436 
3437 	mss = min((bbr->rc_tp->t_maxseg - bbr->rc_last_options), bbr->r_ctl.rc_pace_max_segs);
3438 	/* Get the base cwnd with gain rounded to a mss */
3439 	cwnd = roundup(bbr_get_raw_target_cwnd(bbr, bw, gain), mss);
3440 	/*
3441 	 * Add in N (2 default since we do not have a
3442 	 * fq layer to trap packets in) quanta's per the I-D
3443 	 * section 4.2.3.2 quanta adjust.
3444 	 */
3445 	cwnd += (bbr_quanta * bbr->r_ctl.rc_pace_max_segs);
3446 	if (bbr->rc_use_google) {
3447 		if((bbr->rc_bbr_state == BBR_STATE_PROBE_BW) &&
3448 		   (bbr_state_val(bbr) == BBR_SUB_GAIN)) {
3449 			/*
3450 			 * The linux implementation adds
3451 			 * an extra 2 x mss in gain cycle which
3452 			 * is documented no-where except in the code.
3453 			 * so we add more for Neal undocumented feature
3454 			 */
3455 			cwnd += 2 * mss;
3456 		}
3457  		if ((cwnd / mss) & 0x1) {
3458 			/* Round up for odd num mss */
3459 			cwnd += mss;
3460 		}
3461 	}
3462 	/* Are we below the min cwnd? */
3463 	if (cwnd < get_min_cwnd(bbr))
3464 		return (get_min_cwnd(bbr));
3465 	return (cwnd);
3466 }
3467 
3468 static uint16_t
3469 bbr_gain_adjust(struct tcp_bbr *bbr, uint16_t gain)
3470 {
3471 	if (gain < 1)
3472 		gain = 1;
3473 	return (gain);
3474 }
3475 
3476 static uint32_t
3477 bbr_get_header_oh(struct tcp_bbr *bbr)
3478 {
3479 	int seg_oh;
3480 
3481 	seg_oh = 0;
3482 	if (bbr->r_ctl.rc_inc_tcp_oh) {
3483 		/* Do we include TCP overhead? */
3484 		seg_oh = (bbr->rc_last_options + sizeof(struct tcphdr));
3485 	}
3486 	if (bbr->r_ctl.rc_inc_ip_oh) {
3487 		/* Do we include IP overhead? */
3488 #ifdef INET6
3489 		if (bbr->r_is_v6) {
3490 			seg_oh += sizeof(struct ip6_hdr);
3491 		} else
3492 #endif
3493 		{
3494 
3495 #ifdef INET
3496 			seg_oh += sizeof(struct ip);
3497 #endif
3498 		}
3499 	}
3500 	if (bbr->r_ctl.rc_inc_enet_oh) {
3501 		/* Do we include the ethernet overhead?  */
3502 		seg_oh += sizeof(struct ether_header);
3503 	}
3504 	return(seg_oh);
3505 }
3506 
3507 static uint32_t
3508 bbr_get_pacing_length(struct tcp_bbr *bbr, uint16_t gain, uint32_t useconds_time, uint64_t bw)
3509 {
3510 	uint64_t divor, res, tim;
3511 
3512 	if (useconds_time == 0)
3513 		return (0);
3514 	gain = bbr_gain_adjust(bbr, gain);
3515 	divor = (uint64_t)USECS_IN_SECOND * (uint64_t)BBR_UNIT;
3516 	tim = useconds_time;
3517 	res = (tim * bw * gain) / divor;
3518 	if (res == 0)
3519 		res = 1;
3520 	return ((uint32_t)res);
3521 }
3522 
3523 /*
3524  * Given a gain and a length return the delay in useconds that
3525  * should be used to evenly space out packets
3526  * on the connection (based on the gain factor).
3527  */
3528 static uint32_t
3529 bbr_get_pacing_delay(struct tcp_bbr *bbr, uint16_t gain, int32_t len, uint32_t cts, int nolog)
3530 {
3531 	uint64_t bw, lentim, res;
3532 	uint32_t usecs, srtt, over = 0;
3533 	uint32_t seg_oh, num_segs, maxseg;
3534 
3535 	if (len == 0)
3536 		return (0);
3537 
3538 	maxseg = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
3539 	num_segs = (len + maxseg - 1) / maxseg;
3540 	if (bbr->rc_use_google == 0) {
3541 		seg_oh = bbr_get_header_oh(bbr);
3542 		len += (num_segs * seg_oh);
3543 	}
3544 	gain = bbr_gain_adjust(bbr, gain);
3545 	bw = bbr_get_bw(bbr);
3546 	if (bbr->rc_use_google) {
3547 		uint64_t cbw;
3548 
3549 		/*
3550 		 * Reduce the b/w by the google discount
3551 		 * factor 10 = 1%.
3552 		 */
3553 		cbw = bw *  (uint64_t)(1000 - bbr->r_ctl.bbr_google_discount);
3554 		cbw /= (uint64_t)1000;
3555 		/* We don't apply a discount if it results in 0 */
3556 		if (cbw > 0)
3557 			bw = cbw;
3558 	}
3559 	lentim = ((uint64_t)len *
3560 		  (uint64_t)USECS_IN_SECOND *
3561 		  (uint64_t)BBR_UNIT);
3562 	res = lentim / ((uint64_t)gain * bw);
3563 	if (res == 0)
3564 		res = 1;
3565 	usecs = (uint32_t)res;
3566 	srtt = bbr_get_rtt(bbr, BBR_SRTT);
3567 	if (bbr_hptsi_max_mul && bbr_hptsi_max_div &&
3568 	    (bbr->rc_use_google == 0) &&
3569 	    (usecs > ((srtt * bbr_hptsi_max_mul) / bbr_hptsi_max_div))) {
3570 		/*
3571 		 * We cannot let the delay be more than 1/2 the srtt time.
3572 		 * Otherwise we cannot pace out or send properly.
3573 		 */
3574 		over = usecs = (srtt * bbr_hptsi_max_mul) / bbr_hptsi_max_div;
3575 		BBR_STAT_INC(bbr_hpts_min_time);
3576 	}
3577 	if (!nolog)
3578 		bbr_log_pacing_delay_calc(bbr, gain, len, cts, usecs, bw, over, 1);
3579 	return (usecs);
3580 }
3581 
3582 static void
3583 bbr_ack_received(struct tcpcb *tp, struct tcp_bbr *bbr, struct tcphdr *th, uint32_t bytes_this_ack,
3584 		 uint32_t sack_changed, uint32_t prev_acked, int32_t line, uint32_t losses)
3585 {
3586 	uint64_t bw;
3587 	uint32_t cwnd, target_cwnd, saved_bytes, maxseg;
3588 	int32_t meth;
3589 
3590 	INP_WLOCK_ASSERT(tptoinpcb(tp));
3591 
3592 #ifdef STATS
3593 	if ((tp->t_flags & TF_GPUTINPROG) &&
3594 	    SEQ_GEQ(th->th_ack, tp->gput_ack)) {
3595 		/*
3596 		 * Strech acks and compressed acks will cause this to
3597 		 * oscillate but we are doing it the same way as the main
3598 		 * stack so it will be compariable (though possibly not
3599 		 * ideal).
3600 		 */
3601 		int32_t cgput;
3602 		int64_t gput, time_stamp;
3603 
3604 		gput = (int64_t) (th->th_ack - tp->gput_seq) * 8;
3605 		time_stamp = max(1, ((bbr->r_ctl.rc_rcvtime - tp->gput_ts) / 1000));
3606 		cgput = gput / time_stamp;
3607 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_GPUT,
3608 					 cgput);
3609 		if (tp->t_stats_gput_prev > 0)
3610 			stats_voi_update_abs_s32(tp->t_stats,
3611 						 VOI_TCP_GPUT_ND,
3612 						 ((gput - tp->t_stats_gput_prev) * 100) /
3613 						 tp->t_stats_gput_prev);
3614 		tp->t_flags &= ~TF_GPUTINPROG;
3615 		tp->t_stats_gput_prev = cgput;
3616 	}
3617 #endif
3618 	if ((bbr->rc_bbr_state == BBR_STATE_PROBE_RTT) &&
3619 	    ((bbr->r_ctl.bbr_rttprobe_gain_val == 0) || bbr->rc_use_google)) {
3620 		/* We don't change anything in probe-rtt */
3621 		return;
3622 	}
3623 	maxseg = tp->t_maxseg - bbr->rc_last_options;
3624 	saved_bytes = bytes_this_ack;
3625 	bytes_this_ack += sack_changed;
3626 	if (bytes_this_ack > prev_acked) {
3627 		bytes_this_ack -= prev_acked;
3628 		/*
3629 		 * A byte ack'd gives us a full mss
3630 		 * to be like linux i.e. they count packets.
3631 		 */
3632 		if ((bytes_this_ack < maxseg) && bbr->rc_use_google)
3633 			bytes_this_ack = maxseg;
3634 	} else {
3635 		/* Unlikely */
3636 		bytes_this_ack = 0;
3637 	}
3638 	cwnd = tp->snd_cwnd;
3639 	bw = get_filter_value(&bbr->r_ctl.rc_delrate);
3640 	if (bw)
3641 		target_cwnd = bbr_get_target_cwnd(bbr,
3642 						  bw,
3643 						  (uint32_t)bbr->r_ctl.rc_bbr_cwnd_gain);
3644 	else
3645 		target_cwnd = bbr_initial_cwnd(bbr, bbr->rc_tp);
3646 	if (IN_RECOVERY(tp->t_flags) &&
3647 	    (bbr->bbr_prev_in_rec == 0)) {
3648 		/*
3649 		 * We are entering recovery and
3650 		 * thus packet conservation.
3651 		 */
3652 		bbr->pkt_conservation = 1;
3653 		bbr->r_ctl.rc_recovery_start = bbr->r_ctl.rc_rcvtime;
3654 		cwnd = ctf_flight_size(tp,
3655 				       (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) +
3656 			bytes_this_ack;
3657 	}
3658 	if (IN_RECOVERY(tp->t_flags)) {
3659 		uint32_t flight;
3660 
3661 		bbr->bbr_prev_in_rec = 1;
3662 		if (cwnd > losses) {
3663 			cwnd -= losses;
3664 			if (cwnd < maxseg)
3665 				cwnd = maxseg;
3666 		} else
3667 			cwnd = maxseg;
3668 		flight = ctf_flight_size(tp,
3669 					 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
3670 		bbr_log_type_cwndupd(bbr, flight, 0,
3671 				     losses, 10, 0, 0, line);
3672 		if (bbr->pkt_conservation) {
3673 			uint32_t time_in;
3674 
3675 			if (TSTMP_GEQ(bbr->r_ctl.rc_rcvtime, bbr->r_ctl.rc_recovery_start))
3676 				time_in = bbr->r_ctl.rc_rcvtime - bbr->r_ctl.rc_recovery_start;
3677 			else
3678 				time_in = 0;
3679 
3680 			if (time_in >= bbr_get_rtt(bbr, BBR_RTT_PROP)) {
3681 				/* Clear packet conservation after an rttProp */
3682 				bbr->pkt_conservation = 0;
3683 			} else {
3684 				if ((flight + bytes_this_ack) > cwnd)
3685 					cwnd = flight + bytes_this_ack;
3686 				if (cwnd < get_min_cwnd(bbr))
3687 					cwnd = get_min_cwnd(bbr);
3688 				tp->snd_cwnd = cwnd;
3689 				bbr_log_type_cwndupd(bbr, saved_bytes, sack_changed,
3690 						     prev_acked, 1, target_cwnd, th->th_ack, line);
3691 				return;
3692 			}
3693 		}
3694 	} else
3695 		bbr->bbr_prev_in_rec = 0;
3696 	if ((bbr->rc_use_google == 0) && bbr->r_ctl.restrict_growth) {
3697 		bbr->r_ctl.restrict_growth--;
3698 		if (bytes_this_ack > maxseg)
3699 			bytes_this_ack = maxseg;
3700 	}
3701 	if (bbr->rc_filled_pipe) {
3702 		/*
3703 		 * Here we have exited startup and filled the pipe. We will
3704 		 * thus allow the cwnd to shrink to the target. We hit here
3705 		 * mostly.
3706 		 */
3707 		uint32_t s_cwnd;
3708 
3709 		meth = 2;
3710 		s_cwnd = min((cwnd + bytes_this_ack), target_cwnd);
3711 		if (s_cwnd > cwnd)
3712 			cwnd = s_cwnd;
3713 		else if (bbr_cwnd_may_shrink || bbr->rc_use_google || bbr->rc_no_pacing)
3714 			cwnd = s_cwnd;
3715 	} else {
3716 		/*
3717 		 * Here we are still in startup, we increase cwnd by what
3718 		 * has been acked.
3719 		 */
3720 		if ((cwnd < target_cwnd) ||
3721 		    (bbr->rc_past_init_win == 0)) {
3722 			meth = 3;
3723 			cwnd += bytes_this_ack;
3724 		} else {
3725 			/*
3726 			 * Method 4 means we are at target so no gain in
3727 			 * startup and past the initial window.
3728 			 */
3729 			meth = 4;
3730 		}
3731 	}
3732 	tp->snd_cwnd = max(cwnd, get_min_cwnd(bbr));
3733 	bbr_log_type_cwndupd(bbr, saved_bytes, sack_changed, prev_acked, meth, target_cwnd, th->th_ack, line);
3734 }
3735 
3736 static void
3737 tcp_bbr_partialack(struct tcpcb *tp)
3738 {
3739 	struct tcp_bbr *bbr;
3740 
3741 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
3742 	INP_WLOCK_ASSERT(tptoinpcb(tp));
3743 	if (ctf_flight_size(tp,
3744 		(bbr->r_ctl.rc_sacked  + bbr->r_ctl.rc_lost_bytes)) <=
3745 	    tp->snd_cwnd) {
3746 		bbr->r_wanted_output = 1;
3747 	}
3748 }
3749 
3750 static void
3751 bbr_post_recovery(struct tcpcb *tp)
3752 {
3753 	struct tcp_bbr *bbr;
3754 	uint32_t  flight;
3755 
3756 	INP_WLOCK_ASSERT(tptoinpcb(tp));
3757 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
3758 	/*
3759 	 * Here we just exit recovery.
3760 	 */
3761 	EXIT_RECOVERY(tp->t_flags);
3762 	/* Lock in our b/w reduction for the specified number of pkt-epochs */
3763 	bbr->r_recovery_bw = 0;
3764 	tp->snd_recover = tp->snd_una;
3765 	tcp_bbr_tso_size_check(bbr, bbr->r_ctl.rc_rcvtime);
3766 	bbr->pkt_conservation = 0;
3767 	if (bbr->rc_use_google == 0) {
3768 		/*
3769 		 * For non-google mode lets
3770 		 * go ahead and make sure we clear
3771 		 * the recovery state so if we
3772 		 * bounce back in to recovery we
3773 		 * will do PC.
3774 		 */
3775 		bbr->bbr_prev_in_rec = 0;
3776 	}
3777 	bbr_log_type_exit_rec(bbr);
3778 	if (bbr->rc_bbr_state != BBR_STATE_PROBE_RTT) {
3779 		tp->snd_cwnd = max(tp->snd_cwnd, bbr->r_ctl.rc_cwnd_on_ent);
3780 		bbr_log_type_cwndupd(bbr, 0, 0, 0, 15, 0, 0, __LINE__);
3781 	} else {
3782 		/* For probe-rtt case lets fix up its saved_cwnd */
3783 		if (bbr->r_ctl.rc_saved_cwnd < bbr->r_ctl.rc_cwnd_on_ent) {
3784 			bbr->r_ctl.rc_saved_cwnd = bbr->r_ctl.rc_cwnd_on_ent;
3785 			bbr_log_type_cwndupd(bbr, 0, 0, 0, 16, 0, 0, __LINE__);
3786 		}
3787 	}
3788 	flight = ctf_flight_size(tp,
3789 		     (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
3790 	if ((bbr->rc_use_google == 0) &&
3791 	    bbr_do_red) {
3792 		uint64_t val, lr2use;
3793 		uint32_t maxseg, newcwnd, acks_inflight, ratio, cwnd;
3794 		uint32_t *cwnd_p;
3795 
3796 		if (bbr_get_rtt(bbr, BBR_SRTT)) {
3797 			val = ((uint64_t)bbr_get_rtt(bbr, BBR_RTT_PROP) * (uint64_t)1000);
3798 			val /= bbr_get_rtt(bbr, BBR_SRTT);
3799 			ratio = (uint32_t)val;
3800 		} else
3801 			ratio = 1000;
3802 
3803 		bbr_log_type_cwndupd(bbr, bbr_red_mul, bbr_red_div,
3804 				     bbr->r_ctl.recovery_lr, 21,
3805 				     ratio,
3806 				     bbr->r_ctl.rc_red_cwnd_pe,
3807 				     __LINE__);
3808 		if ((ratio < bbr_do_red) || (bbr_do_red == 0))
3809 			goto done;
3810 		if (((bbr->rc_bbr_state == BBR_STATE_PROBE_RTT) &&
3811 		     bbr_prtt_slam_cwnd) ||
3812 		    (bbr_sub_drain_slam_cwnd &&
3813 		     (bbr->rc_bbr_state == BBR_STATE_PROBE_BW) &&
3814 		     bbr->rc_hit_state_1 &&
3815 		     (bbr_state_val(bbr) == BBR_SUB_DRAIN)) ||
3816 		    ((bbr->rc_bbr_state == BBR_STATE_DRAIN) &&
3817 		     bbr_slam_cwnd_in_main_drain)) {
3818 			/*
3819 			 * Here we must poke at the saved cwnd
3820 			 * as well as the cwnd.
3821 			 */
3822 			cwnd = bbr->r_ctl.rc_saved_cwnd;
3823 			cwnd_p = &bbr->r_ctl.rc_saved_cwnd;
3824 		} else {
3825  			cwnd = tp->snd_cwnd;
3826 			cwnd_p = &tp->snd_cwnd;
3827 		}
3828 		maxseg = tp->t_maxseg - bbr->rc_last_options;
3829 		/* Add the overall lr with the recovery lr */
3830 		if (bbr->r_ctl.rc_lost == 0)
3831 			lr2use = 0;
3832 		else if (bbr->r_ctl.rc_delivered == 0)
3833 			lr2use = 1000;
3834 		else {
3835 			lr2use = (uint64_t)bbr->r_ctl.rc_lost * (uint64_t)1000;
3836 			lr2use /= bbr->r_ctl.rc_delivered;
3837 		}
3838 		lr2use += bbr->r_ctl.recovery_lr;
3839 		acks_inflight = (flight / (maxseg * 2));
3840 		if (bbr_red_scale) {
3841 			lr2use *= bbr_get_rtt(bbr, BBR_SRTT);
3842 			lr2use /= bbr_red_scale;
3843 			if ((bbr_red_growth_restrict) &&
3844 			    ((bbr_get_rtt(bbr, BBR_SRTT)/bbr_red_scale) > 1))
3845 			    bbr->r_ctl.restrict_growth += acks_inflight;
3846 		}
3847 		if (lr2use) {
3848 			val = (uint64_t)cwnd * lr2use;
3849 			val /= 1000;
3850 			if (cwnd > val)
3851 				newcwnd = roundup((cwnd - val), maxseg);
3852 			else
3853 				newcwnd = maxseg;
3854 		} else {
3855 			val = (uint64_t)cwnd * (uint64_t)bbr_red_mul;
3856 			val /= (uint64_t)bbr_red_div;
3857 			newcwnd = roundup((uint32_t)val, maxseg);
3858 		}
3859 		/* with standard delayed acks how many acks can I expect? */
3860 		if (bbr_drop_limit == 0) {
3861 			/*
3862 			 * Anticpate how much we will
3863 			 * raise the cwnd based on the acks.
3864 			 */
3865 			if ((newcwnd + (acks_inflight * maxseg)) < get_min_cwnd(bbr)) {
3866 				/* We do enforce the min (with the acks) */
3867 				newcwnd = (get_min_cwnd(bbr) - acks_inflight);
3868 			}
3869 		} else {
3870 			/*
3871 			 * A strict drop limit of N is inplace
3872 			 */
3873 			if (newcwnd < (bbr_drop_limit * maxseg)) {
3874 				newcwnd = bbr_drop_limit * maxseg;
3875 			}
3876 		}
3877 		/* For the next N acks do we restrict the growth */
3878 		*cwnd_p = newcwnd;
3879 		if (tp->snd_cwnd > newcwnd)
3880 			tp->snd_cwnd = newcwnd;
3881 		bbr_log_type_cwndupd(bbr, bbr_red_mul, bbr_red_div, val, 22,
3882 				     (uint32_t)lr2use,
3883 				     bbr_get_rtt(bbr, BBR_SRTT), __LINE__);
3884 		bbr->r_ctl.rc_red_cwnd_pe = bbr->r_ctl.rc_pkt_epoch;
3885 	}
3886 done:
3887 	bbr->r_ctl.recovery_lr = 0;
3888 	if (flight <= tp->snd_cwnd) {
3889 		bbr->r_wanted_output = 1;
3890 	}
3891 	tcp_bbr_tso_size_check(bbr, bbr->r_ctl.rc_rcvtime);
3892 }
3893 
3894 static void
3895 bbr_setup_red_bw(struct tcp_bbr *bbr, uint32_t cts)
3896 {
3897 	bbr->r_ctl.red_bw = get_filter_value(&bbr->r_ctl.rc_delrate);
3898 	/* Limit the drop in b/w to 1/2 our current filter. */
3899 	if (bbr->r_ctl.red_bw > bbr->r_ctl.rc_bbr_cur_del_rate)
3900 		bbr->r_ctl.red_bw = bbr->r_ctl.rc_bbr_cur_del_rate;
3901 	if (bbr->r_ctl.red_bw < (get_filter_value(&bbr->r_ctl.rc_delrate) / 2))
3902 		bbr->r_ctl.red_bw = get_filter_value(&bbr->r_ctl.rc_delrate) / 2;
3903 	tcp_bbr_tso_size_check(bbr, cts);
3904 }
3905 
3906 static void
3907 bbr_cong_signal(struct tcpcb *tp, struct tcphdr *th, uint32_t type, struct bbr_sendmap *rsm)
3908 {
3909 	struct tcp_bbr *bbr;
3910 
3911 	INP_WLOCK_ASSERT(tptoinpcb(tp));
3912 #ifdef STATS
3913 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_CSIG, type);
3914 #endif
3915 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
3916 	switch (type) {
3917 	case CC_NDUPACK:
3918 		if (!IN_RECOVERY(tp->t_flags)) {
3919 			tp->snd_recover = tp->snd_max;
3920 			/* Start a new epoch */
3921 			bbr_set_pktepoch(bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
3922 			if (bbr->rc_lt_is_sampling || bbr->rc_lt_use_bw) {
3923 				/*
3924 				 * Move forward the lt epoch
3925 				 * so it won't count the truncated
3926 				 * epoch.
3927 				 */
3928 				bbr->r_ctl.rc_lt_epoch++;
3929 			}
3930 			if (bbr->rc_bbr_state == BBR_STATE_STARTUP) {
3931 				/*
3932 				 * Just like the policer detection code
3933 				 * if we are in startup we must push
3934 				 * forward the last startup epoch
3935 				 * to hide the truncated PE.
3936 				 */
3937 				bbr->r_ctl.rc_bbr_last_startup_epoch++;
3938 			}
3939 			bbr->r_ctl.rc_cwnd_on_ent = tp->snd_cwnd;
3940 			ENTER_RECOVERY(tp->t_flags);
3941 			bbr->rc_tlp_rtx_out = 0;
3942 			bbr->r_ctl.recovery_lr = bbr->r_ctl.rc_pkt_epoch_loss_rate;
3943 			tcp_bbr_tso_size_check(bbr, bbr->r_ctl.rc_rcvtime);
3944 			if (tcp_in_hpts(bbr->rc_tp) &&
3945 			    ((bbr->r_ctl.rc_hpts_flags & PACE_TMR_RACK) == 0)) {
3946 				/*
3947 				 * When we enter recovery, we need to restart
3948 				 * any timers. This may mean we gain an agg
3949 				 * early, which will be made up for at the last
3950 				 * rxt out.
3951 				 */
3952 				bbr->rc_timer_first = 1;
3953 				bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
3954 			}
3955 			/*
3956 			 * Calculate a new cwnd based on to the current
3957 			 * delivery rate with no gain. We get the bdp
3958 			 * without gaining it up like we normally would and
3959 			 * we use the last cur_del_rate.
3960 			 */
3961 			if ((bbr->rc_use_google == 0) &&
3962 			    (bbr->r_ctl.bbr_rttprobe_gain_val ||
3963 			     (bbr->rc_bbr_state != BBR_STATE_PROBE_RTT))) {
3964 				tp->snd_cwnd = ctf_flight_size(tp,
3965 					           (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) +
3966 					(tp->t_maxseg - bbr->rc_last_options);
3967 				if (tp->snd_cwnd < get_min_cwnd(bbr)) {
3968 					/* We always gate to min cwnd */
3969 					tp->snd_cwnd = get_min_cwnd(bbr);
3970 				}
3971 				bbr_log_type_cwndupd(bbr, 0, 0, 0, 14, 0, 0, __LINE__);
3972 			}
3973 			bbr_log_type_enter_rec(bbr, rsm->r_start);
3974 		}
3975 		break;
3976 	case CC_RTO_ERR:
3977 		KMOD_TCPSTAT_INC(tcps_sndrexmitbad);
3978 		/* RTO was unnecessary, so reset everything. */
3979 		bbr_reset_lt_bw_sampling(bbr, bbr->r_ctl.rc_rcvtime);
3980 		if (bbr->rc_bbr_state != BBR_STATE_PROBE_RTT) {
3981 			tp->snd_cwnd = tp->snd_cwnd_prev;
3982 			tp->snd_ssthresh = tp->snd_ssthresh_prev;
3983 			tp->snd_recover = tp->snd_recover_prev;
3984 			tp->snd_cwnd = max(tp->snd_cwnd, bbr->r_ctl.rc_cwnd_on_ent);
3985 			bbr_log_type_cwndupd(bbr, 0, 0, 0, 13, 0, 0, __LINE__);
3986 		}
3987 		tp->t_badrxtwin = 0;
3988 		break;
3989 	}
3990 }
3991 
3992 /*
3993  * Indicate whether this ack should be delayed.  We can delay the ack if
3994  * following conditions are met:
3995  *	- There is no delayed ack timer in progress.
3996  *	- Our last ack wasn't a 0-sized window. We never want to delay
3997  *	  the ack that opens up a 0-sized window.
3998  *	- LRO wasn't used for this segment. We make sure by checking that the
3999  *	  segment size is not larger than the MSS.
4000  *	- Delayed acks are enabled or this is a half-synchronized T/TCP
4001  *	  connection.
4002  *	- The data being acked is less than a full segment (a stretch ack
4003  *        of more than a segment we should ack.
4004  *      - nsegs is 1 (if its more than that we received more than 1 ack).
4005  */
4006 #define DELAY_ACK(tp, bbr, nsegs)				\
4007 	(((tp->t_flags & TF_RXWIN0SENT) == 0) &&		\
4008 	 ((tp->t_flags & TF_DELACK) == 0) && 		 	\
4009 	 ((bbr->bbr_segs_rcvd + nsegs) < tp->t_delayed_ack) &&	\
4010 	 (tp->t_delayed_ack || (tp->t_flags & TF_NEEDSYN)))
4011 
4012 /*
4013  * Return the lowest RSM in the map of
4014  * packets still in flight that is not acked.
4015  * This should normally find on the first one
4016  * since we remove packets from the send
4017  * map after they are marked ACKED.
4018  */
4019 static struct bbr_sendmap *
4020 bbr_find_lowest_rsm(struct tcp_bbr *bbr)
4021 {
4022 	struct bbr_sendmap *rsm;
4023 
4024 	/*
4025 	 * Walk the time-order transmitted list looking for an rsm that is
4026 	 * not acked. This will be the one that was sent the longest time
4027 	 * ago that is still outstanding.
4028 	 */
4029 	TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_tmap, r_tnext) {
4030 		if (rsm->r_flags & BBR_ACKED) {
4031 			continue;
4032 		}
4033 		goto finish;
4034 	}
4035 finish:
4036 	return (rsm);
4037 }
4038 
4039 static struct bbr_sendmap *
4040 bbr_find_high_nonack(struct tcp_bbr *bbr, struct bbr_sendmap *rsm)
4041 {
4042 	struct bbr_sendmap *prsm;
4043 
4044 	/*
4045 	 * Walk the sequence order list backward until we hit and arrive at
4046 	 * the highest seq not acked. In theory when this is called it
4047 	 * should be the last segment (which it was not).
4048 	 */
4049 	prsm = rsm;
4050 	TAILQ_FOREACH_REVERSE_FROM(prsm, &bbr->r_ctl.rc_map, bbr_head, r_next) {
4051 		if (prsm->r_flags & (BBR_ACKED | BBR_HAS_FIN)) {
4052 			continue;
4053 		}
4054 		return (prsm);
4055 	}
4056 	return (NULL);
4057 }
4058 
4059 /*
4060  * Returns to the caller the number of microseconds that
4061  * the packet can be outstanding before we think we
4062  * should have had an ack returned.
4063  */
4064 static uint32_t
4065 bbr_calc_thresh_rack(struct tcp_bbr *bbr, uint32_t srtt, uint32_t cts, struct bbr_sendmap *rsm)
4066 {
4067 	/*
4068 	 * lro is the flag we use to determine if we have seen reordering.
4069 	 * If it gets set we have seen reordering. The reorder logic either
4070 	 * works in one of two ways:
4071 	 *
4072 	 * If reorder-fade is configured, then we track the last time we saw
4073 	 * re-ordering occur. If we reach the point where enough time as
4074 	 * passed we no longer consider reordering has occuring.
4075 	 *
4076 	 * Or if reorder-face is 0, then once we see reordering we consider
4077 	 * the connection to alway be subject to reordering and just set lro
4078 	 * to 1.
4079 	 *
4080 	 * In the end if lro is non-zero we add the extra time for
4081 	 * reordering in.
4082 	 */
4083 	int32_t lro;
4084 	uint32_t thresh, t_rxtcur;
4085 
4086 	if (srtt == 0)
4087 		srtt = 1;
4088 	if (bbr->r_ctl.rc_reorder_ts) {
4089 		if (bbr->r_ctl.rc_reorder_fade) {
4090 			if (SEQ_GEQ(cts, bbr->r_ctl.rc_reorder_ts)) {
4091 				lro = cts - bbr->r_ctl.rc_reorder_ts;
4092 				if (lro == 0) {
4093 					/*
4094 					 * No time as passed since the last
4095 					 * reorder, mark it as reordering.
4096 					 */
4097 					lro = 1;
4098 				}
4099 			} else {
4100 				/* Negative time? */
4101 				lro = 0;
4102 			}
4103 			if (lro > bbr->r_ctl.rc_reorder_fade) {
4104 				/* Turn off reordering seen too */
4105 				bbr->r_ctl.rc_reorder_ts = 0;
4106 				lro = 0;
4107 			}
4108 		} else {
4109 			/* Reodering does not fade */
4110 			lro = 1;
4111 		}
4112 	} else {
4113 		lro = 0;
4114 	}
4115 	thresh = srtt + bbr->r_ctl.rc_pkt_delay;
4116 	if (lro) {
4117 		/* It must be set, if not you get 1/4 rtt */
4118 		if (bbr->r_ctl.rc_reorder_shift)
4119 			thresh += (srtt >> bbr->r_ctl.rc_reorder_shift);
4120 		else
4121 			thresh += (srtt >> 2);
4122 	} else {
4123 		thresh += 1000;
4124 	}
4125 	/* We don't let the rack timeout be above a RTO */
4126 	if ((bbr->rc_tp)->t_srtt == 0)
4127 		t_rxtcur = BBR_INITIAL_RTO;
4128 	else
4129 		t_rxtcur = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
4130 	if (thresh > t_rxtcur) {
4131 		thresh = t_rxtcur;
4132 	}
4133 	/* And we don't want it above the RTO max either */
4134 	if (thresh > (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND)) {
4135 		thresh = (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND);
4136 	}
4137 	bbr_log_thresh_choice(bbr, cts, thresh, lro, srtt, rsm, BBR_TO_FRM_RACK);
4138 	return (thresh);
4139 }
4140 
4141 /*
4142  * Return to the caller the amount of time in mico-seconds
4143  * that should be used for the TLP timer from the last
4144  * send time of this packet.
4145  */
4146 static uint32_t
4147 bbr_calc_thresh_tlp(struct tcpcb *tp, struct tcp_bbr *bbr,
4148     struct bbr_sendmap *rsm, uint32_t srtt,
4149     uint32_t cts)
4150 {
4151 	uint32_t thresh, len, maxseg, t_rxtcur;
4152 	struct bbr_sendmap *prsm;
4153 
4154 	if (srtt == 0)
4155 		srtt = 1;
4156 	if (bbr->rc_tlp_threshold)
4157 		thresh = srtt + (srtt / bbr->rc_tlp_threshold);
4158 	else
4159 		thresh = (srtt * 2);
4160 	maxseg = tp->t_maxseg - bbr->rc_last_options;
4161 	/* Get the previous sent packet, if any  */
4162 	len = rsm->r_end - rsm->r_start;
4163 
4164 	/* 2.1 behavior */
4165 	prsm = TAILQ_PREV(rsm, bbr_head, r_tnext);
4166 	if (prsm && (len <= maxseg)) {
4167 		/*
4168 		 * Two packets outstanding, thresh should be (2*srtt) +
4169 		 * possible inter-packet delay (if any).
4170 		 */
4171 		uint32_t inter_gap = 0;
4172 		int idx, nidx;
4173 
4174 		idx = rsm->r_rtr_cnt - 1;
4175 		nidx = prsm->r_rtr_cnt - 1;
4176 		if (TSTMP_GEQ(rsm->r_tim_lastsent[nidx], prsm->r_tim_lastsent[idx])) {
4177 			/* Yes it was sent later (or at the same time) */
4178 			inter_gap = rsm->r_tim_lastsent[idx] - prsm->r_tim_lastsent[nidx];
4179 		}
4180 		thresh += inter_gap;
4181 	} else if (len <= maxseg) {
4182 		/*
4183 		 * Possibly compensate for delayed-ack.
4184 		 */
4185 		uint32_t alt_thresh;
4186 
4187 		alt_thresh = srtt + (srtt / 2) + bbr_delayed_ack_time;
4188 		if (alt_thresh > thresh)
4189 			thresh = alt_thresh;
4190 	}
4191 	/* Not above the current  RTO */
4192 	if (tp->t_srtt == 0)
4193 		t_rxtcur = BBR_INITIAL_RTO;
4194 	else
4195 		t_rxtcur = TICKS_2_USEC(tp->t_rxtcur);
4196 
4197 	bbr_log_thresh_choice(bbr, cts, thresh, t_rxtcur, srtt, rsm, BBR_TO_FRM_TLP);
4198 	/* Not above an RTO */
4199 	if (thresh > t_rxtcur) {
4200 		thresh = t_rxtcur;
4201 	}
4202 	/* Not above a RTO max */
4203 	if (thresh > (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND)) {
4204 		thresh = (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND);
4205 	}
4206 	/* And now apply the user TLP min */
4207 	if (thresh < bbr_tlp_min) {
4208 		thresh = bbr_tlp_min;
4209 	}
4210 	return (thresh);
4211 }
4212 
4213 /*
4214  * Return one of three RTTs to use (in microseconds).
4215  */
4216 static __inline uint32_t
4217 bbr_get_rtt(struct tcp_bbr *bbr, int32_t rtt_type)
4218 {
4219 	uint32_t f_rtt;
4220 	uint32_t srtt;
4221 
4222 	f_rtt = get_filter_value_small(&bbr->r_ctl.rc_rttprop);
4223 	if (get_filter_value_small(&bbr->r_ctl.rc_rttprop) == 0xffffffff) {
4224 		/* We have no rtt at all */
4225 		if (bbr->rc_tp->t_srtt == 0)
4226 			f_rtt = BBR_INITIAL_RTO;
4227 		else
4228 			f_rtt = (TICKS_2_USEC(bbr->rc_tp->t_srtt) >> TCP_RTT_SHIFT);
4229 		/*
4230 		 * Since we don't know how good the rtt is apply a
4231 		 * delayed-ack min
4232 		 */
4233 		if (f_rtt < bbr_delayed_ack_time) {
4234 			f_rtt = bbr_delayed_ack_time;
4235 		}
4236 	}
4237 	/* Take the filter version or last measured pkt-rtt */
4238 	if (rtt_type == BBR_RTT_PROP) {
4239 		srtt = f_rtt;
4240 	} else if (rtt_type == BBR_RTT_PKTRTT) {
4241 		if (bbr->r_ctl.rc_pkt_epoch_rtt) {
4242 			srtt = bbr->r_ctl.rc_pkt_epoch_rtt;
4243 		} else {
4244 			/* No pkt rtt yet */
4245 			srtt = f_rtt;
4246 		}
4247 	} else if (rtt_type == BBR_RTT_RACK) {
4248 		srtt = bbr->r_ctl.rc_last_rtt;
4249 		/* We need to add in any internal delay for our timer */
4250 		if (bbr->rc_ack_was_delayed)
4251 			srtt += bbr->r_ctl.rc_ack_hdwr_delay;
4252 	} else if (rtt_type == BBR_SRTT) {
4253 		srtt = (TICKS_2_USEC(bbr->rc_tp->t_srtt) >> TCP_RTT_SHIFT);
4254 	} else {
4255 		/* TSNH */
4256 		srtt = f_rtt;
4257 #ifdef BBR_INVARIANTS
4258 		panic("Unknown rtt request type %d", rtt_type);
4259 #endif
4260 	}
4261 	return (srtt);
4262 }
4263 
4264 static int
4265 bbr_is_lost(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, uint32_t cts)
4266 {
4267 	uint32_t thresh;
4268 
4269 	thresh = bbr_calc_thresh_rack(bbr, bbr_get_rtt(bbr, BBR_RTT_RACK),
4270 				      cts, rsm);
4271 	if ((cts - rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]) >= thresh) {
4272 		/* It is lost (past time) */
4273 		return (1);
4274 	}
4275 	return (0);
4276 }
4277 
4278 /*
4279  * Return a sendmap if we need to retransmit something.
4280  */
4281 static struct bbr_sendmap *
4282 bbr_check_recovery_mode(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4283 {
4284 	/*
4285 	 * Check to see that we don't need to fall into recovery. We will
4286 	 * need to do so if our oldest transmit is past the time we should
4287 	 * have had an ack.
4288 	 */
4289 
4290 	struct bbr_sendmap *rsm;
4291 	int32_t idx;
4292 
4293 	if (TAILQ_EMPTY(&bbr->r_ctl.rc_map)) {
4294 		/* Nothing outstanding that we know of */
4295 		return (NULL);
4296 	}
4297 	rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
4298 	if (rsm == NULL) {
4299 		/* Nothing in the transmit map */
4300 		return (NULL);
4301 	}
4302 	if (tp->t_flags & TF_SENTFIN) {
4303 		/* Fin restricted, don't find anything once a fin is sent */
4304 		return (NULL);
4305 	}
4306 	if (rsm->r_flags & BBR_ACKED) {
4307 		/*
4308 		 * Ok the first one is acked (this really should not happen
4309 		 * since we remove the from the tmap once they are acked)
4310 		 */
4311 		rsm = bbr_find_lowest_rsm(bbr);
4312 		if (rsm == NULL)
4313 			return (NULL);
4314 	}
4315 	idx = rsm->r_rtr_cnt - 1;
4316 	if (SEQ_LEQ(cts, rsm->r_tim_lastsent[idx])) {
4317 		/* Send timestamp is the same or less? can't be ready */
4318 		return (NULL);
4319 	}
4320 	/* Get our RTT time */
4321 	if (bbr_is_lost(bbr, rsm, cts) &&
4322 	    ((rsm->r_dupack >= DUP_ACK_THRESHOLD) ||
4323 	     (rsm->r_flags & BBR_SACK_PASSED))) {
4324 		if ((rsm->r_flags & BBR_MARKED_LOST) == 0) {
4325 			rsm->r_flags |= BBR_MARKED_LOST;
4326 			bbr->r_ctl.rc_lost += rsm->r_end - rsm->r_start;
4327 			bbr->r_ctl.rc_lost_bytes += rsm->r_end - rsm->r_start;
4328 		}
4329 		bbr_cong_signal(tp, NULL, CC_NDUPACK, rsm);
4330 #ifdef BBR_INVARIANTS
4331 		if ((rsm->r_end - rsm->r_start) == 0)
4332 			panic("tp:%p bbr:%p rsm:%p length is 0?", tp, bbr, rsm);
4333 #endif
4334 		return (rsm);
4335 	}
4336 	return (NULL);
4337 }
4338 
4339 /*
4340  * RACK Timer, here we simply do logging and house keeping.
4341  * the normal bbr_output_wtime() function will call the
4342  * appropriate thing to check if we need to do a RACK retransmit.
4343  * We return 1, saying don't proceed with bbr_output_wtime only
4344  * when all timers have been stopped (destroyed PCB?).
4345  */
4346 static int
4347 bbr_timeout_rack(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4348 {
4349 	/*
4350 	 * This timer simply provides an internal trigger to send out data.
4351 	 * The check_recovery_mode call will see if there are needed
4352 	 * retransmissions, if so we will enter fast-recovery. The output
4353 	 * call may or may not do the same thing depending on sysctl
4354 	 * settings.
4355 	 */
4356 	uint32_t lost;
4357 
4358 	if (bbr->rc_all_timers_stopped) {
4359 		return (1);
4360 	}
4361 	if (TSTMP_LT(cts, bbr->r_ctl.rc_timer_exp)) {
4362 		/* Its not time yet */
4363 		return (0);
4364 	}
4365 	BBR_STAT_INC(bbr_to_tot);
4366 	lost = bbr->r_ctl.rc_lost;
4367 	if (bbr->r_state && (bbr->r_state != tp->t_state))
4368 		bbr_set_state(tp, bbr, 0);
4369 	bbr_log_to_event(bbr, cts, BBR_TO_FRM_RACK);
4370 	if (bbr->r_ctl.rc_resend == NULL) {
4371 		/* Lets do the check here */
4372 		bbr->r_ctl.rc_resend = bbr_check_recovery_mode(tp, bbr, cts);
4373 	}
4374 	if (bbr_policer_call_from_rack_to)
4375 		bbr_lt_bw_sampling(bbr, cts, (bbr->r_ctl.rc_lost > lost));
4376 	bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_RACK;
4377 	return (0);
4378 }
4379 
4380 static __inline void
4381 bbr_clone_rsm(struct tcp_bbr *bbr, struct bbr_sendmap *nrsm, struct bbr_sendmap *rsm, uint32_t start)
4382 {
4383 	int idx;
4384 
4385 	nrsm->r_start = start;
4386 	nrsm->r_end = rsm->r_end;
4387 	nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
4388 	nrsm-> r_rtt_not_allowed = rsm->r_rtt_not_allowed;
4389 	nrsm->r_flags = rsm->r_flags;
4390 	/* We don't transfer forward the SYN flag */
4391 	nrsm->r_flags &= ~BBR_HAS_SYN;
4392 	/* We move forward the FIN flag, not that this should happen */
4393 	rsm->r_flags &= ~BBR_HAS_FIN;
4394 	nrsm->r_dupack = rsm->r_dupack;
4395 	nrsm->r_rtr_bytes = 0;
4396 	nrsm->r_is_gain = rsm->r_is_gain;
4397 	nrsm->r_is_drain = rsm->r_is_drain;
4398 	nrsm->r_delivered = rsm->r_delivered;
4399 	nrsm->r_ts_valid = rsm->r_ts_valid;
4400 	nrsm->r_del_ack_ts = rsm->r_del_ack_ts;
4401 	nrsm->r_del_time = rsm->r_del_time;
4402 	nrsm->r_app_limited = rsm->r_app_limited;
4403 	nrsm->r_first_sent_time = rsm->r_first_sent_time;
4404 	nrsm->r_flight_at_send = rsm->r_flight_at_send;
4405 	/* We split a piece the lower section looses any just_ret flag. */
4406 	nrsm->r_bbr_state = rsm->r_bbr_state;
4407 	for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
4408 		nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
4409 	}
4410 	rsm->r_end = nrsm->r_start;
4411 	idx = min((bbr->rc_tp->t_maxseg - bbr->rc_last_options), bbr->r_ctl.rc_pace_max_segs);
4412 	idx /= 8;
4413 	/* Check if we got too small */
4414 	if ((rsm->r_is_smallmap == 0) &&
4415 	    ((rsm->r_end - rsm->r_start) <= idx)) {
4416 		bbr->r_ctl.rc_num_small_maps_alloced++;
4417 		rsm->r_is_smallmap = 1;
4418 	}
4419 	/* Check the new one as well */
4420 	if ((nrsm->r_end - nrsm->r_start) <= idx) {
4421 		bbr->r_ctl.rc_num_small_maps_alloced++;
4422 		nrsm->r_is_smallmap = 1;
4423 	}
4424 }
4425 
4426 static int
4427 bbr_sack_mergable(struct bbr_sendmap *at,
4428 		  uint32_t start, uint32_t end)
4429 {
4430 	/*
4431 	 * Given a sack block defined by
4432 	 * start and end, and a current position
4433 	 * at. Return 1 if either side of at
4434 	 * would show that the block is mergable
4435 	 * to that side. A block to be mergable
4436 	 * must have overlap with the start/end
4437 	 * and be in the SACK'd state.
4438 	 */
4439 	struct bbr_sendmap *l_rsm;
4440 	struct bbr_sendmap *r_rsm;
4441 
4442 	/* first get the either side blocks */
4443 	l_rsm = TAILQ_PREV(at, bbr_head, r_next);
4444 	r_rsm = TAILQ_NEXT(at, r_next);
4445 	if (l_rsm && (l_rsm->r_flags & BBR_ACKED)) {
4446 		/* Potentially mergeable */
4447 		if ((l_rsm->r_end == start) ||
4448 		    (SEQ_LT(start, l_rsm->r_end) &&
4449 		     SEQ_GT(end, l_rsm->r_end))) {
4450 			    /*
4451 			     * map blk   |------|
4452 			     * sack blk         |------|
4453 			     * <or>
4454 			     * map blk   |------|
4455 			     * sack blk      |------|
4456 			     */
4457 			    return (1);
4458 		    }
4459 	}
4460 	if (r_rsm && (r_rsm->r_flags & BBR_ACKED)) {
4461 		/* Potentially mergeable */
4462 		if ((r_rsm->r_start == end) ||
4463 		    (SEQ_LT(start, r_rsm->r_start) &&
4464 		     SEQ_GT(end, r_rsm->r_start))) {
4465 			/*
4466 			 * map blk          |---------|
4467 			 * sack blk    |----|
4468 			 * <or>
4469 			 * map blk          |---------|
4470 			 * sack blk    |-------|
4471 			 */
4472 			return (1);
4473 		}
4474 	}
4475 	return (0);
4476 }
4477 
4478 static struct bbr_sendmap *
4479 bbr_merge_rsm(struct tcp_bbr *bbr,
4480 	      struct bbr_sendmap *l_rsm,
4481 	      struct bbr_sendmap *r_rsm)
4482 {
4483 	/*
4484 	 * We are merging two ack'd RSM's,
4485 	 * the l_rsm is on the left (lower seq
4486 	 * values) and the r_rsm is on the right
4487 	 * (higher seq value). The simplest way
4488 	 * to merge these is to move the right
4489 	 * one into the left. I don't think there
4490 	 * is any reason we need to try to find
4491 	 * the oldest (or last oldest retransmitted).
4492 	 */
4493 	l_rsm->r_end = r_rsm->r_end;
4494 	if (l_rsm->r_dupack < r_rsm->r_dupack)
4495 		l_rsm->r_dupack = r_rsm->r_dupack;
4496 	if (r_rsm->r_rtr_bytes)
4497 		l_rsm->r_rtr_bytes += r_rsm->r_rtr_bytes;
4498 	if (r_rsm->r_in_tmap) {
4499 		/* This really should not happen */
4500 		TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, r_rsm, r_tnext);
4501 	}
4502 	if (r_rsm->r_app_limited)
4503 		l_rsm->r_app_limited = r_rsm->r_app_limited;
4504 	/* Now the flags */
4505 	if (r_rsm->r_flags & BBR_HAS_FIN)
4506 		l_rsm->r_flags |= BBR_HAS_FIN;
4507 	if (r_rsm->r_flags & BBR_TLP)
4508 		l_rsm->r_flags |= BBR_TLP;
4509 	if (r_rsm->r_flags & BBR_RWND_COLLAPSED)
4510 		l_rsm->r_flags |= BBR_RWND_COLLAPSED;
4511 	if (r_rsm->r_flags & BBR_MARKED_LOST) {
4512 		/* This really should not happen */
4513 		bbr->r_ctl.rc_lost_bytes -= r_rsm->r_end - r_rsm->r_start;
4514 	}
4515 	TAILQ_REMOVE(&bbr->r_ctl.rc_map, r_rsm, r_next);
4516 	if ((r_rsm->r_limit_type == 0) && (l_rsm->r_limit_type != 0)) {
4517 		/* Transfer the split limit to the map we free */
4518 		r_rsm->r_limit_type = l_rsm->r_limit_type;
4519 		l_rsm->r_limit_type = 0;
4520 	}
4521 	bbr_free(bbr, r_rsm);
4522 	return(l_rsm);
4523 }
4524 
4525 /*
4526  * TLP Timer, here we simply setup what segment we want to
4527  * have the TLP expire on, the normal bbr_output_wtime() will then
4528  * send it out.
4529  *
4530  * We return 1, saying don't proceed with bbr_output_wtime only
4531  * when all timers have been stopped (destroyed PCB?).
4532  */
4533 static int
4534 bbr_timeout_tlp(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4535 {
4536 	/*
4537 	 * Tail Loss Probe.
4538 	 */
4539 	struct bbr_sendmap *rsm = NULL;
4540 	struct socket *so;
4541 	uint32_t amm;
4542 	uint32_t out, avail;
4543 	uint32_t maxseg;
4544 	int collapsed_win = 0;
4545 
4546 	if (bbr->rc_all_timers_stopped) {
4547 		return (1);
4548 	}
4549 	if (TSTMP_LT(cts, bbr->r_ctl.rc_timer_exp)) {
4550 		/* Its not time yet */
4551 		return (0);
4552 	}
4553 	if (ctf_progress_timeout_check(tp, true)) {
4554 		bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
4555 		return (-ETIMEDOUT);	/* tcp_drop() */
4556 	}
4557 	/* Did we somehow get into persists? */
4558 	if (bbr->rc_in_persist) {
4559 		return (0);
4560 	}
4561 	if (bbr->r_state && (bbr->r_state != tp->t_state))
4562 		bbr_set_state(tp, bbr, 0);
4563 	BBR_STAT_INC(bbr_tlp_tot);
4564 	maxseg = tp->t_maxseg - bbr->rc_last_options;
4565 	/*
4566 	 * A TLP timer has expired. We have been idle for 2 rtts. So we now
4567 	 * need to figure out how to force a full MSS segment out.
4568 	 */
4569 	so = tptosocket(tp);
4570 	avail = sbavail(&so->so_snd);
4571 	out = ctf_outstanding(tp);
4572 	if (out > tp->snd_wnd) {
4573 		/* special case, we need a retransmission */
4574 		collapsed_win = 1;
4575 		goto need_retran;
4576 	}
4577 	if (avail > out) {
4578 		/* New data is available */
4579 		amm = avail - out;
4580 		if (amm > maxseg) {
4581 			amm = maxseg;
4582 		} else if ((amm < maxseg) && ((tp->t_flags & TF_NODELAY) == 0)) {
4583 			/* not enough to fill a MTU and no-delay is off */
4584 			goto need_retran;
4585 		}
4586 		/* Set the send-new override */
4587 		if ((out + amm) <= tp->snd_wnd) {
4588 			bbr->rc_tlp_new_data = 1;
4589 		} else {
4590 			goto need_retran;
4591 		}
4592 		bbr->r_ctl.rc_tlp_seg_send_cnt = 0;
4593 		bbr->r_ctl.rc_last_tlp_seq = tp->snd_max;
4594 		bbr->r_ctl.rc_tlp_send = NULL;
4595 		/* cap any slots */
4596 		BBR_STAT_INC(bbr_tlp_newdata);
4597 		goto send;
4598 	}
4599 need_retran:
4600 	/*
4601 	 * Ok we need to arrange the last un-acked segment to be re-sent, or
4602 	 * optionally the first un-acked segment.
4603 	 */
4604 	if (collapsed_win == 0) {
4605 		rsm = TAILQ_LAST_FAST(&bbr->r_ctl.rc_map, bbr_sendmap, r_next);
4606 		if (rsm && (rsm->r_flags & (BBR_ACKED | BBR_HAS_FIN))) {
4607 			rsm = bbr_find_high_nonack(bbr, rsm);
4608 		}
4609 		if (rsm == NULL) {
4610 			goto restore;
4611 		}
4612 	} else {
4613 		/*
4614 		 * We must find the last segment
4615 		 * that was acceptable by the client.
4616 		 */
4617 		TAILQ_FOREACH_REVERSE(rsm, &bbr->r_ctl.rc_map, bbr_head, r_next) {
4618 			if ((rsm->r_flags & BBR_RWND_COLLAPSED) == 0) {
4619 				/* Found one */
4620 				break;
4621 			}
4622 		}
4623 		if (rsm == NULL) {
4624 			/* None? if so send the first */
4625 			rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
4626 			if (rsm == NULL)
4627 				goto restore;
4628 		}
4629 	}
4630 	if ((rsm->r_end - rsm->r_start) > maxseg) {
4631 		/*
4632 		 * We need to split this the last segment in two.
4633 		 */
4634 		struct bbr_sendmap *nrsm;
4635 
4636 		nrsm = bbr_alloc_full_limit(bbr);
4637 		if (nrsm == NULL) {
4638 			/*
4639 			 * We can't get memory to split, we can either just
4640 			 * not split it. Or retransmit the whole piece, lets
4641 			 * do the large send (BTLP :-) ).
4642 			 */
4643 			goto go_for_it;
4644 		}
4645 		bbr_clone_rsm(bbr, nrsm, rsm, (rsm->r_end - maxseg));
4646 		TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
4647 		if (rsm->r_in_tmap) {
4648 			TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
4649 			nrsm->r_in_tmap = 1;
4650 		}
4651 		rsm->r_flags &= (~BBR_HAS_FIN);
4652 		rsm = nrsm;
4653 	}
4654 go_for_it:
4655 	bbr->r_ctl.rc_tlp_send = rsm;
4656 	bbr->rc_tlp_rtx_out = 1;
4657 	if (rsm->r_start == bbr->r_ctl.rc_last_tlp_seq) {
4658 		bbr->r_ctl.rc_tlp_seg_send_cnt++;
4659 		tp->t_rxtshift++;
4660 	} else {
4661 		bbr->r_ctl.rc_last_tlp_seq = rsm->r_start;
4662 		bbr->r_ctl.rc_tlp_seg_send_cnt = 1;
4663 	}
4664 send:
4665 	if (bbr->r_ctl.rc_tlp_seg_send_cnt > bbr_tlp_max_resend) {
4666 		/*
4667 		 * Can't [re]/transmit a segment we have retransmitted the
4668 		 * max times. We need the retransmit timer to take over.
4669 		 */
4670 restore:
4671 		bbr->rc_tlp_new_data = 0;
4672 		bbr->r_ctl.rc_tlp_send = NULL;
4673 		if (rsm)
4674 			rsm->r_flags &= ~BBR_TLP;
4675 		BBR_STAT_INC(bbr_tlp_retran_fail);
4676 		return (0);
4677 	} else if (rsm) {
4678 		rsm->r_flags |= BBR_TLP;
4679 	}
4680 	if (rsm && (rsm->r_start == bbr->r_ctl.rc_last_tlp_seq) &&
4681 	    (bbr->r_ctl.rc_tlp_seg_send_cnt > bbr_tlp_max_resend)) {
4682 		/*
4683 		 * We have retransmitted to many times for TLP. Switch to
4684 		 * the regular RTO timer
4685 		 */
4686 		goto restore;
4687 	}
4688 	bbr_log_to_event(bbr, cts, BBR_TO_FRM_TLP);
4689 	bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
4690 	return (0);
4691 }
4692 
4693 /*
4694  * Delayed ack Timer, here we simply need to setup the
4695  * ACK_NOW flag and remove the DELACK flag. From there
4696  * the output routine will send the ack out.
4697  *
4698  * We only return 1, saying don't proceed, if all timers
4699  * are stopped (destroyed PCB?).
4700  */
4701 static int
4702 bbr_timeout_delack(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4703 {
4704 	if (bbr->rc_all_timers_stopped) {
4705 		return (1);
4706 	}
4707 	bbr_log_to_event(bbr, cts, BBR_TO_FRM_DELACK);
4708 	tp->t_flags &= ~TF_DELACK;
4709 	tp->t_flags |= TF_ACKNOW;
4710 	KMOD_TCPSTAT_INC(tcps_delack);
4711 	bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
4712 	return (0);
4713 }
4714 
4715 /*
4716  * Here we send a KEEP-ALIVE like probe to the
4717  * peer, we do not send data.
4718  *
4719  * We only return 1, saying don't proceed, if all timers
4720  * are stopped (destroyed PCB?).
4721  */
4722 static int
4723 bbr_timeout_persist(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4724 {
4725 	struct tcptemp *t_template;
4726 	int32_t retval = 1;
4727 
4728 	if (bbr->rc_all_timers_stopped) {
4729 		return (1);
4730 	}
4731 	if (bbr->rc_in_persist == 0)
4732 		return (0);
4733 
4734 	/*
4735 	 * Persistence timer into zero window. Force a byte to be output, if
4736 	 * possible.
4737 	 */
4738 	bbr_log_to_event(bbr, cts, BBR_TO_FRM_PERSIST);
4739 	bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_PERSIT;
4740 	KMOD_TCPSTAT_INC(tcps_persisttimeo);
4741 	/*
4742 	 * Have we exceeded the user specified progress time?
4743 	 */
4744 	if (ctf_progress_timeout_check(tp, true)) {
4745 		bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
4746 		return (-ETIMEDOUT);	/* tcp_drop() */
4747 	}
4748 	/*
4749 	 * Hack: if the peer is dead/unreachable, we do not time out if the
4750 	 * window is closed.  After a full backoff, drop the connection if
4751 	 * the idle time (no responses to probes) reaches the maximum
4752 	 * backoff that we would use if retransmitting.
4753 	 */
4754 	if (tp->t_rxtshift >= V_tcp_retries &&
4755 	    (ticks - tp->t_rcvtime >= tcp_maxpersistidle ||
4756 	    ticks - tp->t_rcvtime >= TCP_REXMTVAL(tp) * tcp_totbackoff)) {
4757 		KMOD_TCPSTAT_INC(tcps_persistdrop);
4758 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
4759 		return (-ETIMEDOUT);	/* tcp_drop() */
4760 	}
4761 	if ((sbavail(&bbr->rc_inp->inp_socket->so_snd) == 0) &&
4762 	    tp->snd_una == tp->snd_max) {
4763 		bbr_exit_persist(tp, bbr, cts, __LINE__);
4764 		retval = 0;
4765 		goto out;
4766 	}
4767 	/*
4768 	 * If the user has closed the socket then drop a persisting
4769 	 * connection after a much reduced timeout.
4770 	 */
4771 	if (tp->t_state > TCPS_CLOSE_WAIT &&
4772 	    (ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) {
4773 		KMOD_TCPSTAT_INC(tcps_persistdrop);
4774 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
4775 		return (-ETIMEDOUT);	/* tcp_drop() */
4776 	}
4777 	t_template = tcpip_maketemplate(bbr->rc_inp);
4778 	if (t_template) {
4779 		tcp_respond(tp, t_template->tt_ipgen,
4780 			    &t_template->tt_t, (struct mbuf *)NULL,
4781 			    tp->rcv_nxt, tp->snd_una - 1, 0);
4782 		/* This sends an ack */
4783 		if (tp->t_flags & TF_DELACK)
4784 			tp->t_flags &= ~TF_DELACK;
4785 		free(t_template, M_TEMP);
4786 	}
4787 	if (tp->t_rxtshift < V_tcp_retries)
4788 		tp->t_rxtshift++;
4789 	bbr_start_hpts_timer(bbr, tp, cts, 3, 0, 0);
4790 out:
4791 	return (retval);
4792 }
4793 
4794 /*
4795  * If a keepalive goes off, we had no other timers
4796  * happening. We always return 1 here since this
4797  * routine either drops the connection or sends
4798  * out a segment with respond.
4799  */
4800 static int
4801 bbr_timeout_keepalive(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4802 {
4803 	struct tcptemp *t_template;
4804 	struct inpcb *inp = tptoinpcb(tp);
4805 
4806 	if (bbr->rc_all_timers_stopped) {
4807 		return (1);
4808 	}
4809 	bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_KEEP;
4810 	bbr_log_to_event(bbr, cts, BBR_TO_FRM_KEEP);
4811 	/*
4812 	 * Keep-alive timer went off; send something or drop connection if
4813 	 * idle for too long.
4814 	 */
4815 	KMOD_TCPSTAT_INC(tcps_keeptimeo);
4816 	if (tp->t_state < TCPS_ESTABLISHED)
4817 		goto dropit;
4818 	if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
4819 	    tp->t_state <= TCPS_CLOSING) {
4820 		if (ticks - tp->t_rcvtime >= TP_KEEPIDLE(tp) + TP_MAXIDLE(tp))
4821 			goto dropit;
4822 		/*
4823 		 * Send a packet designed to force a response if the peer is
4824 		 * up and reachable: either an ACK if the connection is
4825 		 * still alive, or an RST if the peer has closed the
4826 		 * connection due to timeout or reboot. Using sequence
4827 		 * number tp->snd_una-1 causes the transmitted zero-length
4828 		 * segment to lie outside the receive window; by the
4829 		 * protocol spec, this requires the correspondent TCP to
4830 		 * respond.
4831 		 */
4832 		KMOD_TCPSTAT_INC(tcps_keepprobe);
4833 		t_template = tcpip_maketemplate(inp);
4834 		if (t_template) {
4835 			tcp_respond(tp, t_template->tt_ipgen,
4836 			    &t_template->tt_t, (struct mbuf *)NULL,
4837 			    tp->rcv_nxt, tp->snd_una - 1, 0);
4838 			free(t_template, M_TEMP);
4839 		}
4840 	}
4841 	bbr_start_hpts_timer(bbr, tp, cts, 4, 0, 0);
4842 	return (1);
4843 dropit:
4844 	KMOD_TCPSTAT_INC(tcps_keepdrops);
4845 	tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
4846 	return (-ETIMEDOUT);	/* tcp_drop() */
4847 }
4848 
4849 /*
4850  * Retransmit helper function, clear up all the ack
4851  * flags and take care of important book keeping.
4852  */
4853 static void
4854 bbr_remxt_tmr(struct tcpcb *tp)
4855 {
4856 	/*
4857 	 * The retransmit timer went off, all sack'd blocks must be
4858 	 * un-acked.
4859 	 */
4860 	struct bbr_sendmap *rsm, *trsm = NULL;
4861 	struct tcp_bbr *bbr;
4862 	uint32_t cts, lost;
4863 
4864 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
4865 	cts = tcp_get_usecs(&bbr->rc_tv);
4866 	lost = bbr->r_ctl.rc_lost;
4867 	if (bbr->r_state && (bbr->r_state != tp->t_state))
4868 		bbr_set_state(tp, bbr, 0);
4869 
4870 	TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_map, r_next) {
4871 		if (rsm->r_flags & BBR_ACKED) {
4872 			uint32_t old_flags;
4873 
4874 			rsm->r_dupack = 0;
4875 			if (rsm->r_in_tmap == 0) {
4876 				/* We must re-add it back to the tlist */
4877 				if (trsm == NULL) {
4878 					TAILQ_INSERT_HEAD(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
4879 				} else {
4880 					TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, trsm, rsm, r_tnext);
4881 				}
4882 				rsm->r_in_tmap = 1;
4883 			}
4884 			old_flags = rsm->r_flags;
4885 			rsm->r_flags |= BBR_RXT_CLEARED;
4886 			rsm->r_flags &= ~(BBR_ACKED | BBR_SACK_PASSED | BBR_WAS_SACKPASS);
4887 			bbr_log_type_rsmclear(bbr, cts, rsm, old_flags, __LINE__);
4888 		} else {
4889 			if ((tp->t_state < TCPS_ESTABLISHED) &&
4890 			    (rsm->r_start == tp->snd_una)) {
4891 				/*
4892 				 * Special case for TCP FO. Where
4893 				 * we sent more data beyond the snd_max.
4894 				 * We don't mark that as lost and stop here.
4895 				 */
4896 				break;
4897 			}
4898 			if ((rsm->r_flags & BBR_MARKED_LOST) == 0) {
4899 				bbr->r_ctl.rc_lost += rsm->r_end - rsm->r_start;
4900 				bbr->r_ctl.rc_lost_bytes += rsm->r_end - rsm->r_start;
4901 			}
4902 			if (bbr_marks_rxt_sack_passed) {
4903 				/*
4904 				 * With this option, we will rack out
4905 				 * in 1ms increments the rest of the packets.
4906 				 */
4907 				rsm->r_flags |= BBR_SACK_PASSED | BBR_MARKED_LOST;
4908 				rsm->r_flags &= ~BBR_WAS_SACKPASS;
4909 			} else {
4910 				/*
4911 				 * With this option we only mark them lost
4912 				 * and remove all sack'd markings. We will run
4913 				 * another RXT or a TLP. This will cause
4914 				 * us to eventually send more based on what
4915 				 * ack's come in.
4916 				 */
4917 				rsm->r_flags |= BBR_MARKED_LOST;
4918 				rsm->r_flags &= ~BBR_WAS_SACKPASS;
4919 				rsm->r_flags &= ~BBR_SACK_PASSED;
4920 			}
4921 		}
4922 		trsm = rsm;
4923 	}
4924 	bbr->r_ctl.rc_resend = TAILQ_FIRST(&bbr->r_ctl.rc_map);
4925 	/* Clear the count (we just un-acked them) */
4926 	bbr_log_to_event(bbr, cts, BBR_TO_FRM_TMR);
4927 	bbr->rc_tlp_new_data = 0;
4928 	bbr->r_ctl.rc_tlp_seg_send_cnt = 0;
4929 	/* zap the behindness on a rxt */
4930 	bbr->r_ctl.rc_hptsi_agg_delay = 0;
4931 	bbr->r_agg_early_set = 0;
4932 	bbr->r_ctl.rc_agg_early = 0;
4933 	bbr->rc_tlp_rtx_out = 0;
4934 	bbr->r_ctl.rc_sacked = 0;
4935 	bbr->r_ctl.rc_sacklast = NULL;
4936 	bbr->r_timer_override = 1;
4937 	bbr_lt_bw_sampling(bbr, cts, (bbr->r_ctl.rc_lost > lost));
4938 }
4939 
4940 /*
4941  * Re-transmit timeout! If we drop the PCB we will return 1, otherwise
4942  * we will setup to retransmit the lowest seq number outstanding.
4943  */
4944 static int
4945 bbr_timeout_rxt(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4946 {
4947 	struct inpcb *inp = tptoinpcb(tp);
4948 	int32_t rexmt;
4949 	int32_t retval = 0;
4950 	bool isipv6;
4951 
4952 	bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_RXT;
4953 	if (bbr->rc_all_timers_stopped) {
4954 		return (1);
4955 	}
4956 	if (TCPS_HAVEESTABLISHED(tp->t_state) &&
4957 	    (tp->snd_una == tp->snd_max)) {
4958 		/* Nothing outstanding .. nothing to do */
4959 		return (0);
4960 	}
4961 	/*
4962 	 * Retransmission timer went off.  Message has not been acked within
4963 	 * retransmit interval.  Back off to a longer retransmit interval
4964 	 * and retransmit one segment.
4965 	 */
4966 	if (ctf_progress_timeout_check(tp, true)) {
4967 		bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
4968 		return (-ETIMEDOUT);	/* tcp_drop() */
4969 	}
4970 	bbr_remxt_tmr(tp);
4971 	if ((bbr->r_ctl.rc_resend == NULL) ||
4972 	    ((bbr->r_ctl.rc_resend->r_flags & BBR_RWND_COLLAPSED) == 0)) {
4973 		/*
4974 		 * If the rwnd collapsed on
4975 		 * the one we are retransmitting
4976 		 * it does not count against the
4977 		 * rxt count.
4978 		 */
4979 		tp->t_rxtshift++;
4980 	}
4981 	if (tp->t_rxtshift > V_tcp_retries) {
4982 		tp->t_rxtshift = V_tcp_retries;
4983 		KMOD_TCPSTAT_INC(tcps_timeoutdrop);
4984 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
4985 		/* XXXGL: previously t_softerror was casted to uint16_t */
4986 		MPASS(tp->t_softerror >= 0);
4987 		retval = tp->t_softerror ? -tp->t_softerror : -ETIMEDOUT;
4988 		return (retval);	/* tcp_drop() */
4989 	}
4990 	if (tp->t_state == TCPS_SYN_SENT) {
4991 		/*
4992 		 * If the SYN was retransmitted, indicate CWND to be limited
4993 		 * to 1 segment in cc_conn_init().
4994 		 */
4995 		tp->snd_cwnd = 1;
4996 	} else if (tp->t_rxtshift == 1) {
4997 		/*
4998 		 * first retransmit; record ssthresh and cwnd so they can be
4999 		 * recovered if this turns out to be a "bad" retransmit. A
5000 		 * retransmit is considered "bad" if an ACK for this segment
5001 		 * is received within RTT/2 interval; the assumption here is
5002 		 * that the ACK was already in flight.  See "On Estimating
5003 		 * End-to-End Network Path Properties" by Allman and Paxson
5004 		 * for more details.
5005 		 */
5006 		tp->snd_cwnd = tp->t_maxseg - bbr->rc_last_options;
5007 		if (!IN_RECOVERY(tp->t_flags)) {
5008 			tp->snd_cwnd_prev = tp->snd_cwnd;
5009 			tp->snd_ssthresh_prev = tp->snd_ssthresh;
5010 			tp->snd_recover_prev = tp->snd_recover;
5011 			tp->t_badrxtwin = ticks + (tp->t_srtt >> (TCP_RTT_SHIFT + 1));
5012 			tp->t_flags |= TF_PREVVALID;
5013 		} else {
5014 			tp->t_flags &= ~TF_PREVVALID;
5015 		}
5016 		tp->snd_cwnd = tp->t_maxseg - bbr->rc_last_options;
5017 	} else {
5018 		tp->snd_cwnd = tp->t_maxseg - bbr->rc_last_options;
5019 		tp->t_flags &= ~TF_PREVVALID;
5020 	}
5021 	KMOD_TCPSTAT_INC(tcps_rexmttimeo);
5022 	if ((tp->t_state == TCPS_SYN_SENT) ||
5023 	    (tp->t_state == TCPS_SYN_RECEIVED))
5024 		rexmt = USEC_2_TICKS(BBR_INITIAL_RTO) * tcp_backoff[tp->t_rxtshift];
5025 	else
5026 		rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift];
5027 	TCPT_RANGESET(tp->t_rxtcur, rexmt,
5028 	    MSEC_2_TICKS(bbr->r_ctl.rc_min_rto_ms),
5029 	    MSEC_2_TICKS(((uint32_t)bbr->rc_max_rto_sec) * 1000));
5030 	/*
5031 	 * We enter the path for PLMTUD if connection is established or, if
5032 	 * connection is FIN_WAIT_1 status, reason for the last is that if
5033 	 * amount of data we send is very small, we could send it in couple
5034 	 * of packets and process straight to FIN. In that case we won't
5035 	 * catch ESTABLISHED state.
5036 	 */
5037 #ifdef INET6
5038 	isipv6 = (inp->inp_vflag & INP_IPV6) ? true : false;
5039 #else
5040 	isipv6 = false;
5041 #endif
5042 	if (((V_tcp_pmtud_blackhole_detect == 1) ||
5043 	    (V_tcp_pmtud_blackhole_detect == 2 && !isipv6) ||
5044 	    (V_tcp_pmtud_blackhole_detect == 3 && isipv6)) &&
5045 	    ((tp->t_state == TCPS_ESTABLISHED) ||
5046 	    (tp->t_state == TCPS_FIN_WAIT_1))) {
5047 		/*
5048 		 * Idea here is that at each stage of mtu probe (usually,
5049 		 * 1448 -> 1188 -> 524) should be given 2 chances to recover
5050 		 * before further clamping down. 'tp->t_rxtshift % 2 == 0'
5051 		 * should take care of that.
5052 		 */
5053 		if (((tp->t_flags2 & (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) ==
5054 		    (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) &&
5055 		    (tp->t_rxtshift >= 2 && tp->t_rxtshift < 6 &&
5056 		    tp->t_rxtshift % 2 == 0)) {
5057 			/*
5058 			 * Enter Path MTU Black-hole Detection mechanism: -
5059 			 * Disable Path MTU Discovery (IP "DF" bit). -
5060 			 * Reduce MTU to lower value than what we negotiated
5061 			 * with peer.
5062 			 */
5063 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) == 0) {
5064 				/*
5065 				 * Record that we may have found a black
5066 				 * hole.
5067 				 */
5068 				tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE;
5069 				/* Keep track of previous MSS. */
5070 				tp->t_pmtud_saved_maxseg = tp->t_maxseg;
5071 			}
5072 			/*
5073 			 * Reduce the MSS to blackhole value or to the
5074 			 * default in an attempt to retransmit.
5075 			 */
5076 #ifdef INET6
5077 			isipv6 = bbr->r_is_v6;
5078 			if (isipv6 &&
5079 			    tp->t_maxseg > V_tcp_v6pmtud_blackhole_mss) {
5080 				/* Use the sysctl tuneable blackhole MSS. */
5081 				tp->t_maxseg = V_tcp_v6pmtud_blackhole_mss;
5082 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
5083 			} else if (isipv6) {
5084 				/* Use the default MSS. */
5085 				tp->t_maxseg = V_tcp_v6mssdflt;
5086 				/*
5087 				 * Disable Path MTU Discovery when we switch
5088 				 * to minmss.
5089 				 */
5090 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
5091 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
5092 			}
5093 #endif
5094 #if defined(INET6) && defined(INET)
5095 			else
5096 #endif
5097 #ifdef INET
5098 			if (tp->t_maxseg > V_tcp_pmtud_blackhole_mss) {
5099 				/* Use the sysctl tuneable blackhole MSS. */
5100 				tp->t_maxseg = V_tcp_pmtud_blackhole_mss;
5101 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
5102 			} else {
5103 				/* Use the default MSS. */
5104 				tp->t_maxseg = V_tcp_mssdflt;
5105 				/*
5106 				 * Disable Path MTU Discovery when we switch
5107 				 * to minmss.
5108 				 */
5109 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
5110 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
5111 			}
5112 #endif
5113 		} else {
5114 			/*
5115 			 * If further retransmissions are still unsuccessful
5116 			 * with a lowered MTU, maybe this isn't a blackhole
5117 			 * and we restore the previous MSS and blackhole
5118 			 * detection flags. The limit '6' is determined by
5119 			 * giving each probe stage (1448, 1188, 524) 2
5120 			 * chances to recover.
5121 			 */
5122 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) &&
5123 			    (tp->t_rxtshift >= 6)) {
5124 				tp->t_flags2 |= TF2_PLPMTU_PMTUD;
5125 				tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE;
5126 				tp->t_maxseg = tp->t_pmtud_saved_maxseg;
5127 				if (tp->t_maxseg < V_tcp_mssdflt) {
5128 					/*
5129 					 * The MSS is so small we should not
5130 					 * process incoming SACK's since we are
5131 					 * subject to attack in such a case.
5132 					 */
5133 					tp->t_flags2 |= TF2_PROC_SACK_PROHIBIT;
5134 				} else {
5135 					tp->t_flags2 &= ~TF2_PROC_SACK_PROHIBIT;
5136 				}
5137 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_failed);
5138 			}
5139 		}
5140 	}
5141 	/*
5142 	 * Disable RFC1323 and SACK if we haven't got any response to our
5143 	 * third SYN to work-around some broken terminal servers (most of
5144 	 * which have hopefully been retired) that have bad VJ header
5145 	 * compression code which trashes TCP segments containing
5146 	 * unknown-to-them TCP options.
5147 	 */
5148 	if (tcp_rexmit_drop_options && (tp->t_state == TCPS_SYN_SENT) &&
5149 	    (tp->t_rxtshift == 3))
5150 		tp->t_flags &= ~(TF_REQ_SCALE | TF_REQ_TSTMP | TF_SACK_PERMIT);
5151 	/*
5152 	 * If we backed off this far, our srtt estimate is probably bogus.
5153 	 * Clobber it so we'll take the next rtt measurement as our srtt;
5154 	 * move the current srtt into rttvar to keep the current retransmit
5155 	 * times until then.
5156 	 */
5157 	if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
5158 #ifdef INET6
5159 		if (bbr->r_is_v6)
5160 			in6_losing(inp);
5161 		else
5162 #endif
5163 			in_losing(inp);
5164 		tp->t_rttvar += (tp->t_srtt >> TCP_RTT_SHIFT);
5165 		tp->t_srtt = 0;
5166 	}
5167 	sack_filter_clear(&bbr->r_ctl.bbr_sf, tp->snd_una);
5168 	tp->snd_recover = tp->snd_max;
5169 	tp->t_flags |= TF_ACKNOW;
5170 	tp->t_rtttime = 0;
5171 
5172 	return (retval);
5173 }
5174 
5175 static int
5176 bbr_process_timers(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts, uint8_t hpts_calling)
5177 {
5178 	int32_t ret = 0;
5179 	int32_t timers = (bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK);
5180 
5181 	if (timers == 0) {
5182 		return (0);
5183 	}
5184 	if (tp->t_state == TCPS_LISTEN) {
5185 		/* no timers on listen sockets */
5186 		if (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)
5187 			return (0);
5188 		return (1);
5189 	}
5190 	if (TSTMP_LT(cts, bbr->r_ctl.rc_timer_exp)) {
5191 		uint32_t left;
5192 
5193 		if (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
5194 			ret = -1;
5195 			bbr_log_to_processing(bbr, cts, ret, 0, hpts_calling);
5196 			return (0);
5197 		}
5198 		if (hpts_calling == 0) {
5199 			ret = -2;
5200 			bbr_log_to_processing(bbr, cts, ret, 0, hpts_calling);
5201 			return (0);
5202 		}
5203 		/*
5204 		 * Ok our timer went off early and we are not paced false
5205 		 * alarm, go back to sleep.
5206 		 */
5207 		left = bbr->r_ctl.rc_timer_exp - cts;
5208 		ret = -3;
5209 		bbr_log_to_processing(bbr, cts, ret, left, hpts_calling);
5210 		tcp_hpts_insert(tp, HPTS_USEC_TO_SLOTS(left));
5211 		return (1);
5212 	}
5213 	bbr->rc_tmr_stopped = 0;
5214 	bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_MASK;
5215 	if (timers & PACE_TMR_DELACK) {
5216 		ret = bbr_timeout_delack(tp, bbr, cts);
5217 	} else if (timers & PACE_TMR_PERSIT) {
5218 		ret = bbr_timeout_persist(tp, bbr, cts);
5219 	} else if (timers & PACE_TMR_RACK) {
5220 		bbr->r_ctl.rc_tlp_rxt_last_time = cts;
5221 		ret = bbr_timeout_rack(tp, bbr, cts);
5222 	} else if (timers & PACE_TMR_TLP) {
5223 		bbr->r_ctl.rc_tlp_rxt_last_time = cts;
5224 		ret = bbr_timeout_tlp(tp, bbr, cts);
5225 	} else if (timers & PACE_TMR_RXT) {
5226 		bbr->r_ctl.rc_tlp_rxt_last_time = cts;
5227 		ret = bbr_timeout_rxt(tp, bbr, cts);
5228 	} else if (timers & PACE_TMR_KEEP) {
5229 		ret = bbr_timeout_keepalive(tp, bbr, cts);
5230 	}
5231 	bbr_log_to_processing(bbr, cts, ret, timers, hpts_calling);
5232 	return (ret);
5233 }
5234 
5235 static void
5236 bbr_timer_cancel(struct tcp_bbr *bbr, int32_t line, uint32_t cts)
5237 {
5238 	if (bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
5239 		uint8_t hpts_removed = 0;
5240 
5241 		if (tcp_in_hpts(bbr->rc_tp) &&
5242 		    (bbr->rc_timer_first == 1)) {
5243 			/*
5244 			 * If we are canceling timer's when we have the
5245 			 * timer ahead of the output being paced. We also
5246 			 * must remove ourselves from the hpts.
5247 			 */
5248 			hpts_removed = 1;
5249 			tcp_hpts_remove(bbr->rc_tp);
5250 			if (bbr->r_ctl.rc_last_delay_val) {
5251 				/* Update the last hptsi delay too */
5252 				uint32_t time_since_send;
5253 
5254 				if (TSTMP_GT(cts, bbr->rc_pacer_started))
5255 					time_since_send = cts - bbr->rc_pacer_started;
5256 				else
5257 					time_since_send = 0;
5258 				if (bbr->r_ctl.rc_last_delay_val > time_since_send) {
5259 					/* Cut down our slot time */
5260 					bbr->r_ctl.rc_last_delay_val -= time_since_send;
5261 				} else {
5262 					bbr->r_ctl.rc_last_delay_val = 0;
5263 				}
5264 				bbr->rc_pacer_started = cts;
5265 			}
5266 		}
5267 		bbr->rc_timer_first = 0;
5268 		bbr_log_to_cancel(bbr, line, cts, hpts_removed);
5269 		bbr->rc_tmr_stopped = bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
5270 		bbr->r_ctl.rc_hpts_flags &= ~(PACE_TMR_MASK);
5271 	}
5272 }
5273 
5274 static int
5275 bbr_stopall(struct tcpcb *tp)
5276 {
5277 	struct tcp_bbr *bbr;
5278 
5279 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
5280 	bbr->rc_all_timers_stopped = 1;
5281 
5282 	tcp_hpts_remove(tp);
5283 
5284 	return (0);
5285 }
5286 
5287 static uint32_t
5288 bbr_get_earliest_send_outstanding(struct tcp_bbr *bbr, struct bbr_sendmap *u_rsm, uint32_t cts)
5289 {
5290 	struct bbr_sendmap *rsm;
5291 
5292 	rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
5293 	if ((rsm == NULL) || (u_rsm == rsm))
5294 		return (cts);
5295 	return(rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]);
5296 }
5297 
5298 static void
5299 bbr_update_rsm(struct tcpcb *tp, struct tcp_bbr *bbr,
5300      struct bbr_sendmap *rsm, uint32_t cts, uint32_t pacing_time)
5301 {
5302 	int32_t idx;
5303 
5304 	rsm->r_rtr_cnt++;
5305 	rsm->r_dupack = 0;
5306 	if (rsm->r_rtr_cnt > BBR_NUM_OF_RETRANS) {
5307 		rsm->r_rtr_cnt = BBR_NUM_OF_RETRANS;
5308 		rsm->r_flags |= BBR_OVERMAX;
5309 	}
5310 	if (rsm->r_flags & BBR_RWND_COLLAPSED) {
5311 		/* Take off the collapsed flag at rxt */
5312 		rsm->r_flags &= ~BBR_RWND_COLLAPSED;
5313 	}
5314 	if (rsm->r_flags & BBR_MARKED_LOST) {
5315 		/* We have retransmitted, its no longer lost */
5316 		rsm->r_flags &= ~BBR_MARKED_LOST;
5317 		bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
5318 	}
5319 	if (rsm->r_flags & BBR_RXT_CLEARED) {
5320 		/*
5321 		 * We hit a RXT timer on it and
5322 		 * we cleared the "acked" flag.
5323 		 * We now have it going back into
5324 		 * flight, we can remove the cleared
5325 		 * flag and possibly do accounting on
5326 		 * this piece.
5327 		 */
5328 		rsm->r_flags &= ~BBR_RXT_CLEARED;
5329 	}
5330 	if ((rsm->r_rtr_cnt > 1) && ((rsm->r_flags & BBR_TLP) == 0)) {
5331 		bbr->r_ctl.rc_holes_rxt += (rsm->r_end - rsm->r_start);
5332 		rsm->r_rtr_bytes += (rsm->r_end - rsm->r_start);
5333 	}
5334 	idx = rsm->r_rtr_cnt - 1;
5335 	rsm->r_tim_lastsent[idx] = cts;
5336 	rsm->r_pacing_delay = pacing_time;
5337 	rsm->r_delivered = bbr->r_ctl.rc_delivered;
5338 	rsm->r_ts_valid = bbr->rc_ts_valid;
5339 	if (bbr->rc_ts_valid)
5340 		rsm->r_del_ack_ts = bbr->r_ctl.last_inbound_ts;
5341 	if (bbr->r_ctl.r_app_limited_until)
5342 		rsm->r_app_limited = 1;
5343 	else
5344 		rsm->r_app_limited = 0;
5345 	if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW)
5346 		rsm->r_bbr_state = bbr_state_val(bbr);
5347 	else
5348 		rsm->r_bbr_state = 8;
5349 	if (rsm->r_flags & BBR_ACKED) {
5350 		/* Problably MTU discovery messing with us */
5351 		uint32_t old_flags;
5352 
5353 		old_flags = rsm->r_flags;
5354 		rsm->r_flags &= ~BBR_ACKED;
5355 		bbr_log_type_rsmclear(bbr, cts, rsm, old_flags, __LINE__);
5356 		bbr->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
5357 		if (bbr->r_ctl.rc_sacked == 0)
5358 			bbr->r_ctl.rc_sacklast = NULL;
5359 	}
5360 	if (rsm->r_in_tmap) {
5361 		TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
5362 	}
5363 	TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
5364 	rsm->r_in_tmap = 1;
5365 	if (rsm->r_flags & BBR_SACK_PASSED) {
5366 		/* We have retransmitted due to the SACK pass */
5367 		rsm->r_flags &= ~BBR_SACK_PASSED;
5368 		rsm->r_flags |= BBR_WAS_SACKPASS;
5369 	}
5370 	rsm->r_first_sent_time = bbr_get_earliest_send_outstanding(bbr, rsm, cts);
5371 	rsm->r_flight_at_send = ctf_flight_size(bbr->rc_tp,
5372 						(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
5373 	bbr->r_ctl.rc_next = TAILQ_NEXT(rsm, r_next);
5374 	if (bbr->r_ctl.rc_bbr_hptsi_gain > BBR_UNIT) {
5375 		rsm->r_is_gain = 1;
5376 		rsm->r_is_drain = 0;
5377 	} else if (bbr->r_ctl.rc_bbr_hptsi_gain < BBR_UNIT) {
5378 		rsm->r_is_drain = 1;
5379 		rsm->r_is_gain = 0;
5380 	} else {
5381 		rsm->r_is_drain = 0;
5382 		rsm->r_is_gain = 0;
5383 	}
5384 	rsm->r_del_time = bbr->r_ctl.rc_del_time; /* TEMP GOOGLE CODE */
5385 }
5386 
5387 /*
5388  * Returns 0, or the sequence where we stopped
5389  * updating. We also update the lenp to be the amount
5390  * of data left.
5391  */
5392 
5393 static uint32_t
5394 bbr_update_entry(struct tcpcb *tp, struct tcp_bbr *bbr,
5395     struct bbr_sendmap *rsm, uint32_t cts, int32_t *lenp, uint32_t pacing_time)
5396 {
5397 	/*
5398 	 * We (re-)transmitted starting at rsm->r_start for some length
5399 	 * (possibly less than r_end.
5400 	 */
5401 	struct bbr_sendmap *nrsm;
5402 	uint32_t c_end;
5403 	int32_t len;
5404 
5405 	len = *lenp;
5406 	c_end = rsm->r_start + len;
5407 	if (SEQ_GEQ(c_end, rsm->r_end)) {
5408 		/*
5409 		 * We retransmitted the whole piece or more than the whole
5410 		 * slopping into the next rsm.
5411 		 */
5412 		bbr_update_rsm(tp, bbr, rsm, cts, pacing_time);
5413 		if (c_end == rsm->r_end) {
5414 			*lenp = 0;
5415 			return (0);
5416 		} else {
5417 			int32_t act_len;
5418 
5419 			/* Hangs over the end return whats left */
5420 			act_len = rsm->r_end - rsm->r_start;
5421 			*lenp = (len - act_len);
5422 			return (rsm->r_end);
5423 		}
5424 		/* We don't get out of this block. */
5425 	}
5426 	/*
5427 	 * Here we retransmitted less than the whole thing which means we
5428 	 * have to split this into what was transmitted and what was not.
5429 	 */
5430 	nrsm = bbr_alloc_full_limit(bbr);
5431 	if (nrsm == NULL) {
5432 		*lenp = 0;
5433 		return (0);
5434 	}
5435 	/*
5436 	 * So here we are going to take the original rsm and make it what we
5437 	 * retransmitted. nrsm will be the tail portion we did not
5438 	 * retransmit. For example say the chunk was 1, 11 (10 bytes). And
5439 	 * we retransmitted 5 bytes i.e. 1, 5. The original piece shrinks to
5440 	 * 1, 6 and the new piece will be 6, 11.
5441 	 */
5442 	bbr_clone_rsm(bbr, nrsm, rsm, c_end);
5443 	TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
5444 	nrsm->r_dupack = 0;
5445 	if (rsm->r_in_tmap) {
5446 		TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
5447 		nrsm->r_in_tmap = 1;
5448 	}
5449 	rsm->r_flags &= (~BBR_HAS_FIN);
5450 	bbr_update_rsm(tp, bbr, rsm, cts, pacing_time);
5451 	*lenp = 0;
5452 	return (0);
5453 }
5454 
5455 static uint64_t
5456 bbr_get_hardware_rate(struct tcp_bbr *bbr)
5457 {
5458 	uint64_t bw;
5459 
5460 	bw = bbr_get_bw(bbr);
5461 	bw *= (uint64_t)bbr_hptsi_gain[BBR_SUB_GAIN];
5462 	bw /= (uint64_t)BBR_UNIT;
5463 	return(bw);
5464 }
5465 
5466 static void
5467 bbr_setup_less_of_rate(struct tcp_bbr *bbr, uint32_t cts,
5468 		       uint64_t act_rate, uint64_t rate_wanted)
5469 {
5470 	/*
5471 	 * We could not get a full gains worth
5472 	 * of rate.
5473 	 */
5474 	if (get_filter_value(&bbr->r_ctl.rc_delrate) >= act_rate) {
5475 		/* we can't even get the real rate */
5476 		uint64_t red;
5477 
5478 		bbr->skip_gain = 1;
5479 		bbr->gain_is_limited = 0;
5480 		red = get_filter_value(&bbr->r_ctl.rc_delrate) - act_rate;
5481 		if (red)
5482 			filter_reduce_by(&bbr->r_ctl.rc_delrate, red, cts);
5483 	} else {
5484 		/* We can use a lower gain */
5485 		bbr->skip_gain = 0;
5486 		bbr->gain_is_limited = 1;
5487 	}
5488 }
5489 
5490 static void
5491 bbr_update_hardware_pacing_rate(struct tcp_bbr *bbr, uint32_t cts)
5492 {
5493 	const struct tcp_hwrate_limit_table *nrte;
5494 	int error, rate = -1;
5495 
5496 	if (bbr->r_ctl.crte == NULL)
5497 		return;
5498 	if ((bbr->rc_inp->inp_route.ro_nh == NULL) ||
5499 	    (bbr->rc_inp->inp_route.ro_nh->nh_ifp == NULL)) {
5500 		/* Lost our routes? */
5501 		/* Clear the way for a re-attempt */
5502 		bbr->bbr_attempt_hdwr_pace = 0;
5503 lost_rate:
5504 		bbr->gain_is_limited = 0;
5505 		bbr->skip_gain = 0;
5506 		bbr->bbr_hdrw_pacing = 0;
5507 		counter_u64_add(bbr_flows_whdwr_pacing, -1);
5508 		counter_u64_add(bbr_flows_nohdwr_pacing, 1);
5509 		tcp_bbr_tso_size_check(bbr, cts);
5510 		return;
5511 	}
5512 	rate = bbr_get_hardware_rate(bbr);
5513 	nrte = tcp_chg_pacing_rate(bbr->r_ctl.crte,
5514 				   bbr->rc_tp,
5515 				   bbr->rc_inp->inp_route.ro_nh->nh_ifp,
5516 				   rate,
5517 				   (RS_PACING_GEQ|RS_PACING_SUB_OK),
5518 				   &error, NULL);
5519 	if (nrte == NULL) {
5520 		goto lost_rate;
5521 	}
5522 	if (nrte != bbr->r_ctl.crte) {
5523 		bbr->r_ctl.crte = nrte;
5524 		if (error == 0)  {
5525 			BBR_STAT_INC(bbr_hdwr_rl_mod_ok);
5526 			if (bbr->r_ctl.crte->rate < rate) {
5527 				/* We have a problem */
5528 				bbr_setup_less_of_rate(bbr, cts,
5529 						       bbr->r_ctl.crte->rate, rate);
5530 			} else {
5531 				/* We are good */
5532 				bbr->gain_is_limited = 0;
5533 				bbr->skip_gain = 0;
5534 			}
5535 		} else {
5536 			/* A failure should release the tag */
5537 			BBR_STAT_INC(bbr_hdwr_rl_mod_fail);
5538 			bbr->gain_is_limited = 0;
5539 			bbr->skip_gain = 0;
5540 			bbr->bbr_hdrw_pacing = 0;
5541 		}
5542 		bbr_type_log_hdwr_pacing(bbr,
5543 					 bbr->r_ctl.crte->ptbl->rs_ifp,
5544 					 rate,
5545 					 bbr->r_ctl.crte->rate,
5546 					 __LINE__,
5547 					 cts,
5548 					 error);
5549 	}
5550 }
5551 
5552 static void
5553 bbr_adjust_for_hw_pacing(struct tcp_bbr *bbr, uint32_t cts)
5554 {
5555 	/*
5556 	 * If we have hardware pacing support
5557 	 * we need to factor that in for our
5558 	 * TSO size.
5559 	 */
5560 	const struct tcp_hwrate_limit_table *rlp;
5561 	uint32_t cur_delay, seg_sz, maxseg, new_tso, delta, hdwr_delay;
5562 
5563 	if ((bbr->bbr_hdrw_pacing == 0) ||
5564 	    (IN_RECOVERY(bbr->rc_tp->t_flags)) ||
5565 	    (bbr->r_ctl.crte == NULL))
5566 		return;
5567 	if (bbr->hw_pacing_set == 0) {
5568 		/* Not yet by the hdwr pacing count delay */
5569 		return;
5570 	}
5571 	if (bbr_hdwr_pace_adjust == 0) {
5572 		/* No adjustment */
5573 		return;
5574 	}
5575 	rlp = bbr->r_ctl.crte;
5576 	if (bbr->rc_tp->t_maxseg > bbr->rc_last_options)
5577 		maxseg = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
5578 	else
5579 		maxseg = BBR_MIN_SEG - bbr->rc_last_options;
5580 	/*
5581 	 * So lets first get the
5582 	 * time we will take between
5583 	 * TSO sized sends currently without
5584 	 * hardware help.
5585 	 */
5586 	cur_delay = bbr_get_pacing_delay(bbr, BBR_UNIT,
5587 		        bbr->r_ctl.rc_pace_max_segs, cts, 1);
5588 	hdwr_delay = bbr->r_ctl.rc_pace_max_segs / maxseg;
5589 	hdwr_delay *= rlp->time_between;
5590 	if (cur_delay > hdwr_delay)
5591 		delta = cur_delay - hdwr_delay;
5592 	else
5593 		delta = 0;
5594 	bbr_log_type_tsosize(bbr, cts, delta, cur_delay, hdwr_delay,
5595 			     (bbr->r_ctl.rc_pace_max_segs / maxseg),
5596 			     1);
5597 	if (delta &&
5598 	    (delta < (max(rlp->time_between,
5599 			  bbr->r_ctl.bbr_hptsi_segments_delay_tar)))) {
5600 		/*
5601 		 * Now lets divide by the pacing
5602 		 * time between each segment the
5603 		 * hardware sends rounding up and
5604 		 * derive a bytes from that. We multiply
5605 		 * that by bbr_hdwr_pace_adjust to get
5606 		 * more bang for our buck.
5607 		 *
5608 		 * The goal is to have the software pacer
5609 		 * waiting no more than an additional
5610 		 * pacing delay if we can (without the
5611 		 * compensation i.e. x bbr_hdwr_pace_adjust).
5612 		 */
5613 		seg_sz = max(((cur_delay + rlp->time_between)/rlp->time_between),
5614 			     (bbr->r_ctl.rc_pace_max_segs/maxseg));
5615 		seg_sz *= bbr_hdwr_pace_adjust;
5616 		if (bbr_hdwr_pace_floor &&
5617 		    (seg_sz < bbr->r_ctl.crte->ptbl->rs_min_seg)) {
5618 			/* Currently hardware paces
5619 			 * out rs_min_seg segments at a time.
5620 			 * We need to make sure we always send at least
5621 			 * a full burst of bbr_hdwr_pace_floor down.
5622 			 */
5623 			seg_sz = bbr->r_ctl.crte->ptbl->rs_min_seg;
5624 		}
5625 		seg_sz *= maxseg;
5626 	} else if (delta == 0) {
5627 		/*
5628 		 * The highest pacing rate is
5629 		 * above our b/w gained. This means
5630 		 * we probably are going quite fast at
5631 		 * the hardware highest rate. Lets just multiply
5632 		 * the calculated TSO size by the
5633 		 * multiplier factor (its probably
5634 		 * 4 segments in the default config for
5635 		 * mlx).
5636 		 */
5637 		seg_sz = bbr->r_ctl.rc_pace_max_segs * bbr_hdwr_pace_adjust;
5638 		if (bbr_hdwr_pace_floor &&
5639 		    (seg_sz < bbr->r_ctl.crte->ptbl->rs_min_seg)) {
5640 			/* Currently hardware paces
5641 			 * out rs_min_seg segments at a time.
5642 			 * We need to make sure we always send at least
5643 			 * a full burst of bbr_hdwr_pace_floor down.
5644 			 */
5645 			seg_sz = bbr->r_ctl.crte->ptbl->rs_min_seg;
5646 		}
5647 	} else {
5648 		/*
5649 		 * The pacing time difference is so
5650 		 * big that the hardware will
5651 		 * pace out more rapidly then we
5652 		 * really want and then we
5653 		 * will have a long delay. Lets just keep
5654 		 * the same TSO size so its as if
5655 		 * we were not using hdwr pacing (we
5656 		 * just gain a bit of spacing from the
5657 		 * hardware if seg_sz > 1).
5658 		 */
5659 		seg_sz = bbr->r_ctl.rc_pace_max_segs;
5660 	}
5661 	if (seg_sz > bbr->r_ctl.rc_pace_max_segs)
5662 		new_tso = seg_sz;
5663 	else
5664 		new_tso = bbr->r_ctl.rc_pace_max_segs;
5665 	if (new_tso >= (PACE_MAX_IP_BYTES-maxseg))
5666 		new_tso = PACE_MAX_IP_BYTES - maxseg;
5667 
5668 	if (new_tso != bbr->r_ctl.rc_pace_max_segs) {
5669 		bbr_log_type_tsosize(bbr, cts, new_tso, 0, bbr->r_ctl.rc_pace_max_segs, maxseg, 0);
5670 		bbr->r_ctl.rc_pace_max_segs = new_tso;
5671 	}
5672 }
5673 
5674 static void
5675 tcp_bbr_tso_size_check(struct tcp_bbr *bbr, uint32_t cts)
5676 {
5677 	uint64_t bw;
5678 	uint32_t old_tso = 0, new_tso;
5679 	uint32_t maxseg, bytes;
5680 	uint32_t tls_seg=0;
5681 	/*
5682 	 * Google/linux uses the following algorithm to determine
5683 	 * the TSO size based on the b/w of the link (from Neal Cardwell email 9/27/18):
5684 	 *
5685 	 *  bytes = bw_in_bytes_per_second / 1000
5686 	 *  bytes = min(bytes, 64k)
5687 	 *  tso_segs = bytes / MSS
5688 	 *  if (bw < 1.2Mbs)
5689 	 *      min_tso_segs = 1
5690 	 *  else
5691 	 *	min_tso_segs = 2
5692 	 * tso_segs = max(tso_segs, min_tso_segs)
5693 	 *
5694 	 * * Note apply a device specific limit (we apply this in the
5695 	 *   tcp_m_copym).
5696 	 * Note that before the initial measurement is made google bursts out
5697 	 * a full iwnd just like new-reno/cubic.
5698 	 *
5699 	 * We do not use this algorithm. Instead we
5700 	 * use a two phased approach:
5701 	 *
5702 	 *  if ( bw <= per-tcb-cross-over)
5703 	 *     goal_tso =  calculate how much with this bw we
5704 	 *                 can send in goal-time seconds.
5705 	 *     if (goal_tso > mss)
5706 	 *         seg = goal_tso / mss
5707 	 *         tso = seg * mss
5708 	 *     else
5709 	 *         tso = mss
5710 	 *     if (tso > per-tcb-max)
5711 	 *         tso = per-tcb-max
5712 	 *  else if ( bw > 512Mbps)
5713 	 *     tso = max-tso (64k/mss)
5714 	 *  else
5715 	 *     goal_tso = bw / per-tcb-divsor
5716 	 *     seg = (goal_tso + mss-1)/mss
5717 	 *     tso = seg * mss
5718 	 *
5719 	 * if (tso < per-tcb-floor)
5720 	 *    tso = per-tcb-floor
5721 	 * if (tso > per-tcb-utter_max)
5722 	 *    tso = per-tcb-utter_max
5723 	 *
5724 	 * Note the default per-tcb-divisor is 1000 (same as google).
5725 	 * the goal cross over is 30Mbps however. To recreate googles
5726 	 * algorithm you need to set:
5727 	 *
5728 	 * cross-over = 23,168,000 bps
5729 	 * goal-time = 18000
5730 	 * per-tcb-max = 2
5731 	 * per-tcb-divisor = 1000
5732 	 * per-tcb-floor = 1
5733 	 *
5734 	 * This will get you "google bbr" behavior with respect to tso size.
5735 	 *
5736 	 * Note we do set anything TSO size until we are past the initial
5737 	 * window. Before that we gnerally use either a single MSS
5738 	 * or we use the full IW size (so we burst a IW at a time)
5739 	 */
5740 
5741 	if (bbr->rc_tp->t_maxseg > bbr->rc_last_options) {
5742 		maxseg = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
5743 	} else {
5744 		maxseg = BBR_MIN_SEG - bbr->rc_last_options;
5745 	}
5746 	old_tso = bbr->r_ctl.rc_pace_max_segs;
5747 	if (bbr->rc_past_init_win == 0) {
5748 		/*
5749 		 * Not enough data has been acknowledged to make a
5750 		 * judgement. Set up the initial TSO based on if we
5751 		 * are sending a full IW at once or not.
5752 		 */
5753 		if (bbr->rc_use_google)
5754 			bbr->r_ctl.rc_pace_max_segs = ((bbr->rc_tp->t_maxseg - bbr->rc_last_options) * 2);
5755 		else if (bbr->bbr_init_win_cheat)
5756 			bbr->r_ctl.rc_pace_max_segs = bbr_initial_cwnd(bbr, bbr->rc_tp);
5757 		else
5758 			bbr->r_ctl.rc_pace_max_segs = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
5759 		if (bbr->r_ctl.rc_pace_min_segs != bbr->rc_tp->t_maxseg)
5760 			bbr->r_ctl.rc_pace_min_segs = bbr->rc_tp->t_maxseg;
5761 		if (bbr->r_ctl.rc_pace_max_segs == 0) {
5762 			bbr->r_ctl.rc_pace_max_segs = maxseg;
5763 		}
5764 		bbr_log_type_tsosize(bbr, cts, bbr->r_ctl.rc_pace_max_segs, tls_seg, old_tso, maxseg, 0);
5765 			bbr_adjust_for_hw_pacing(bbr, cts);
5766 		return;
5767 	}
5768 	/**
5769 	 * Now lets set the TSO goal based on our delivery rate in
5770 	 * bytes per second. Note we only do this if
5771 	 * we have acked at least the initial cwnd worth of data.
5772 	 */
5773 	bw = bbr_get_bw(bbr);
5774 	if (IN_RECOVERY(bbr->rc_tp->t_flags) &&
5775 	     (bbr->rc_use_google == 0)) {
5776 		/* We clamp to one MSS in recovery */
5777 		new_tso = maxseg;
5778 	} else if (bbr->rc_use_google) {
5779 		int min_tso_segs;
5780 
5781 		/* Google considers the gain too */
5782 		if (bbr->r_ctl.rc_bbr_hptsi_gain != BBR_UNIT) {
5783 			bw *= bbr->r_ctl.rc_bbr_hptsi_gain;
5784 			bw /= BBR_UNIT;
5785 		}
5786 		bytes = bw / 1024;
5787 		if (bytes > (64 * 1024))
5788 			bytes = 64 * 1024;
5789 		new_tso = bytes / maxseg;
5790 		if (bw < ONE_POINT_TWO_MEG)
5791 			min_tso_segs = 1;
5792 		else
5793 			min_tso_segs = 2;
5794 		if (new_tso < min_tso_segs)
5795 			new_tso = min_tso_segs;
5796 		new_tso *= maxseg;
5797 	} else if (bbr->rc_no_pacing) {
5798 		new_tso = (PACE_MAX_IP_BYTES / maxseg) * maxseg;
5799 	} else if (bw <= bbr->r_ctl.bbr_cross_over) {
5800 		/*
5801 		 * Calculate the worse case b/w TSO if we are inserting no
5802 		 * more than a delay_target number of TSO's.
5803 		 */
5804 		uint32_t tso_len, min_tso;
5805 
5806 		tso_len = bbr_get_pacing_length(bbr, BBR_UNIT, bbr->r_ctl.bbr_hptsi_segments_delay_tar, bw);
5807 		if (tso_len > maxseg) {
5808 			new_tso = tso_len / maxseg;
5809 			if (new_tso > bbr->r_ctl.bbr_hptsi_segments_max)
5810 				new_tso = bbr->r_ctl.bbr_hptsi_segments_max;
5811 			new_tso *= maxseg;
5812 		} else {
5813 			/*
5814 			 * less than a full sized frame yikes.. long rtt or
5815 			 * low bw?
5816 			 */
5817 			min_tso = bbr_minseg(bbr);
5818 			if ((tso_len > min_tso) && (bbr_all_get_min == 0))
5819 				new_tso = rounddown(tso_len, min_tso);
5820 			else
5821 				new_tso = min_tso;
5822 		}
5823 	} else if (bw > FIVETWELVE_MBPS) {
5824 		/*
5825 		 * This guy is so fast b/w wise that we can TSO as large as
5826 		 * possible of segments that the NIC will allow.
5827 		 */
5828 		new_tso = rounddown(PACE_MAX_IP_BYTES, maxseg);
5829 	} else {
5830 		/*
5831 		 * This formula is based on attempting to send a segment or
5832 		 * more every bbr_hptsi_per_second. The default is 1000
5833 		 * which means you are targeting what you can send every 1ms
5834 		 * based on the peers bw.
5835 		 *
5836 		 * If the number drops to say 500, then you are looking more
5837 		 * at 2ms and you will raise how much we send in a single
5838 		 * TSO thus saving CPU (less bbr_output_wtime() calls). The
5839 		 * trade off of course is you will send more at once and
5840 		 * thus tend to clump up the sends into larger "bursts"
5841 		 * building a queue.
5842 		 */
5843 		bw /= bbr->r_ctl.bbr_hptsi_per_second;
5844 		new_tso = roundup(bw, (uint64_t)maxseg);
5845 		/*
5846 		 * Gate the floor to match what our lower than 48Mbps
5847 		 * algorithm does. The ceiling (bbr_hptsi_segments_max) thus
5848 		 * becomes the floor for this calculation.
5849 		 */
5850 		if (new_tso < (bbr->r_ctl.bbr_hptsi_segments_max * maxseg))
5851 			new_tso = (bbr->r_ctl.bbr_hptsi_segments_max * maxseg);
5852 	}
5853 	if (bbr->r_ctl.bbr_hptsi_segments_floor && (new_tso < (maxseg * bbr->r_ctl.bbr_hptsi_segments_floor)))
5854 		new_tso = maxseg * bbr->r_ctl.bbr_hptsi_segments_floor;
5855 	if (new_tso > PACE_MAX_IP_BYTES)
5856 		new_tso = rounddown(PACE_MAX_IP_BYTES, maxseg);
5857 	/* Enforce an utter maximum. */
5858 	if (bbr->r_ctl.bbr_utter_max && (new_tso > (bbr->r_ctl.bbr_utter_max * maxseg))) {
5859 		new_tso = bbr->r_ctl.bbr_utter_max * maxseg;
5860 	}
5861 	if (old_tso != new_tso) {
5862 		/* Only log changes */
5863 		bbr_log_type_tsosize(bbr, cts, new_tso, tls_seg, old_tso, maxseg, 0);
5864 		bbr->r_ctl.rc_pace_max_segs = new_tso;
5865 	}
5866 	/* We have hardware pacing! */
5867 	bbr_adjust_for_hw_pacing(bbr, cts);
5868 }
5869 
5870 static void
5871 bbr_log_output(struct tcp_bbr *bbr, struct tcpcb *tp, struct tcpopt *to, int32_t len,
5872     uint32_t seq_out, uint16_t th_flags, int32_t err, uint32_t cts,
5873     struct mbuf *mb, int32_t * abandon, struct bbr_sendmap *hintrsm, uint32_t delay_calc,
5874     struct sockbuf *sb)
5875 {
5876 
5877 	struct bbr_sendmap *rsm, *nrsm;
5878 	register uint32_t snd_max, snd_una;
5879 	uint32_t pacing_time;
5880 	/*
5881 	 * Add to the RACK log of packets in flight or retransmitted. If
5882 	 * there is a TS option we will use the TS echoed, if not we will
5883 	 * grab a TS.
5884 	 *
5885 	 * Retransmissions will increment the count and move the ts to its
5886 	 * proper place. Note that if options do not include TS's then we
5887 	 * won't be able to effectively use the ACK for an RTT on a retran.
5888 	 *
5889 	 * Notes about r_start and r_end. Lets consider a send starting at
5890 	 * sequence 1 for 10 bytes. In such an example the r_start would be
5891 	 * 1 (starting sequence) but the r_end would be r_start+len i.e. 11.
5892 	 * This means that r_end is actually the first sequence for the next
5893 	 * slot (11).
5894 	 *
5895 	 */
5896 	INP_WLOCK_ASSERT(tptoinpcb(tp));
5897 	if (err) {
5898 		/*
5899 		 * We don't log errors -- we could but snd_max does not
5900 		 * advance in this case either.
5901 		 */
5902 		return;
5903 	}
5904 	if (th_flags & TH_RST) {
5905 		/*
5906 		 * We don't log resets and we return immediately from
5907 		 * sending
5908 		 */
5909 		*abandon = 1;
5910 		return;
5911 	}
5912 	snd_una = tp->snd_una;
5913 	if (th_flags & (TH_SYN | TH_FIN) && (hintrsm == NULL)) {
5914 		/*
5915 		 * The call to bbr_log_output is made before bumping
5916 		 * snd_max. This means we can record one extra byte on a SYN
5917 		 * or FIN if seq_out is adding more on and a FIN is present
5918 		 * (and we are not resending).
5919 		 */
5920 		if ((th_flags & TH_SYN) && (tp->iss == seq_out))
5921 			len++;
5922 		if (th_flags & TH_FIN)
5923 			len++;
5924 	}
5925 	if (SEQ_LEQ((seq_out + len), snd_una)) {
5926 		/* Are sending an old segment to induce an ack (keep-alive)? */
5927 		return;
5928 	}
5929 	if (SEQ_LT(seq_out, snd_una)) {
5930 		/* huh? should we panic? */
5931 		uint32_t end;
5932 
5933 		end = seq_out + len;
5934 		seq_out = snd_una;
5935 		len = end - seq_out;
5936 	}
5937 	snd_max = tp->snd_max;
5938 	if (len == 0) {
5939 		/* We don't log zero window probes */
5940 		return;
5941 	}
5942 	pacing_time = bbr_get_pacing_delay(bbr, bbr->r_ctl.rc_bbr_hptsi_gain, len, cts, 1);
5943 	/* First question is it a retransmission? */
5944 	if (seq_out == snd_max) {
5945 again:
5946 		rsm = bbr_alloc(bbr);
5947 		if (rsm == NULL) {
5948 			return;
5949 		}
5950 		rsm->r_flags = 0;
5951 		if (th_flags & TH_SYN)
5952 			rsm->r_flags |= BBR_HAS_SYN;
5953 		if (th_flags & TH_FIN)
5954 			rsm->r_flags |= BBR_HAS_FIN;
5955 		rsm->r_tim_lastsent[0] = cts;
5956 		rsm->r_rtr_cnt = 1;
5957 		rsm->r_rtr_bytes = 0;
5958 		rsm->r_start = seq_out;
5959 		rsm->r_end = rsm->r_start + len;
5960 		rsm->r_dupack = 0;
5961 		rsm->r_delivered = bbr->r_ctl.rc_delivered;
5962 		rsm->r_pacing_delay = pacing_time;
5963 		rsm->r_ts_valid = bbr->rc_ts_valid;
5964 		if (bbr->rc_ts_valid)
5965 			rsm->r_del_ack_ts = bbr->r_ctl.last_inbound_ts;
5966 		rsm->r_del_time = bbr->r_ctl.rc_del_time;
5967 		if (bbr->r_ctl.r_app_limited_until)
5968 			rsm->r_app_limited = 1;
5969 		else
5970 			rsm->r_app_limited = 0;
5971 		rsm->r_first_sent_time = bbr_get_earliest_send_outstanding(bbr, rsm, cts);
5972 		rsm->r_flight_at_send = ctf_flight_size(bbr->rc_tp,
5973 						(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
5974 		/*
5975 		 * Here we must also add in this rsm since snd_max
5976 		 * is updated after we return from a new send.
5977 		 */
5978 		rsm->r_flight_at_send += len;
5979 		TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_map, rsm, r_next);
5980 		TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
5981 		rsm->r_in_tmap = 1;
5982 		if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW)
5983 			rsm->r_bbr_state = bbr_state_val(bbr);
5984 		else
5985 			rsm->r_bbr_state = 8;
5986 		if (bbr->r_ctl.rc_bbr_hptsi_gain > BBR_UNIT) {
5987 			rsm->r_is_gain = 1;
5988 			rsm->r_is_drain = 0;
5989 		} else if (bbr->r_ctl.rc_bbr_hptsi_gain < BBR_UNIT) {
5990 			rsm->r_is_drain = 1;
5991 			rsm->r_is_gain = 0;
5992 		} else {
5993 			rsm->r_is_drain = 0;
5994 			rsm->r_is_gain = 0;
5995 		}
5996 		return;
5997 	}
5998 	/*
5999 	 * If we reach here its a retransmission and we need to find it.
6000 	 */
6001 more:
6002 	if (hintrsm && (hintrsm->r_start == seq_out)) {
6003 		rsm = hintrsm;
6004 		hintrsm = NULL;
6005 	} else if (bbr->r_ctl.rc_next) {
6006 		/* We have a hint from a previous run */
6007 		rsm = bbr->r_ctl.rc_next;
6008 	} else {
6009 		/* No hints sorry */
6010 		rsm = NULL;
6011 	}
6012 	if ((rsm) && (rsm->r_start == seq_out)) {
6013 		/*
6014 		 * We used rc_next or hintrsm  to retransmit, hopefully the
6015 		 * likely case.
6016 		 */
6017 		seq_out = bbr_update_entry(tp, bbr, rsm, cts, &len, pacing_time);
6018 		if (len == 0) {
6019 			return;
6020 		} else {
6021 			goto more;
6022 		}
6023 	}
6024 	/* Ok it was not the last pointer go through it the hard way. */
6025 	TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_map, r_next) {
6026 		if (rsm->r_start == seq_out) {
6027 			seq_out = bbr_update_entry(tp, bbr, rsm, cts, &len, pacing_time);
6028 			bbr->r_ctl.rc_next = TAILQ_NEXT(rsm, r_next);
6029 			if (len == 0) {
6030 				return;
6031 			} else {
6032 				continue;
6033 			}
6034 		}
6035 		if (SEQ_GEQ(seq_out, rsm->r_start) && SEQ_LT(seq_out, rsm->r_end)) {
6036 			/* Transmitted within this piece */
6037 			/*
6038 			 * Ok we must split off the front and then let the
6039 			 * update do the rest
6040 			 */
6041 			nrsm = bbr_alloc_full_limit(bbr);
6042 			if (nrsm == NULL) {
6043 				bbr_update_rsm(tp, bbr, rsm, cts, pacing_time);
6044 				return;
6045 			}
6046 			/*
6047 			 * copy rsm to nrsm and then trim the front of rsm
6048 			 * to not include this part.
6049 			 */
6050 			bbr_clone_rsm(bbr, nrsm, rsm, seq_out);
6051 			TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
6052 			if (rsm->r_in_tmap) {
6053 				TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
6054 				nrsm->r_in_tmap = 1;
6055 			}
6056 			rsm->r_flags &= (~BBR_HAS_FIN);
6057 			seq_out = bbr_update_entry(tp, bbr, nrsm, cts, &len, pacing_time);
6058 			if (len == 0) {
6059 				return;
6060 			}
6061 		}
6062 	}
6063 	/*
6064 	 * Hmm not found in map did they retransmit both old and on into the
6065 	 * new?
6066 	 */
6067 	if (seq_out == tp->snd_max) {
6068 		goto again;
6069 	} else if (SEQ_LT(seq_out, tp->snd_max)) {
6070 #ifdef BBR_INVARIANTS
6071 		printf("seq_out:%u len:%d snd_una:%u snd_max:%u -- but rsm not found?\n",
6072 		    seq_out, len, tp->snd_una, tp->snd_max);
6073 		printf("Starting Dump of all rack entries\n");
6074 		TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_map, r_next) {
6075 			printf("rsm:%p start:%u end:%u\n",
6076 			    rsm, rsm->r_start, rsm->r_end);
6077 		}
6078 		printf("Dump complete\n");
6079 		panic("seq_out not found rack:%p tp:%p",
6080 		    bbr, tp);
6081 #endif
6082 	} else {
6083 #ifdef BBR_INVARIANTS
6084 		/*
6085 		 * Hmm beyond sndmax? (only if we are using the new rtt-pack
6086 		 * flag)
6087 		 */
6088 		panic("seq_out:%u(%d) is beyond snd_max:%u tp:%p",
6089 		    seq_out, len, tp->snd_max, tp);
6090 #endif
6091 	}
6092 }
6093 
6094 static void
6095 bbr_collapse_rtt(struct tcpcb *tp, struct tcp_bbr *bbr, int32_t rtt)
6096 {
6097 	/*
6098 	 * Collapse timeout back the cum-ack moved.
6099 	 */
6100 	tp->t_rxtshift = 0;
6101 	tp->t_softerror = 0;
6102 }
6103 
6104 static void
6105 tcp_bbr_xmit_timer(struct tcp_bbr *bbr, uint32_t rtt_usecs, uint32_t rsm_send_time, uint32_t r_start, uint32_t tsin)
6106 {
6107 	bbr->rtt_valid = 1;
6108 	bbr->r_ctl.cur_rtt = rtt_usecs;
6109 	bbr->r_ctl.ts_in = tsin;
6110 	if (rsm_send_time)
6111 		bbr->r_ctl.cur_rtt_send_time = rsm_send_time;
6112 }
6113 
6114 static void
6115 bbr_make_timestamp_determination(struct tcp_bbr *bbr)
6116 {
6117 	/**
6118 	 * We have in our bbr control:
6119 	 * 1) The timestamp we started observing cum-acks (bbr->r_ctl.bbr_ts_check_tstmp).
6120 	 * 2) Our timestamp indicating when we sent that packet (bbr->r_ctl.rsm->bbr_ts_check_our_cts).
6121 	 * 3) The current timestamp that just came in (bbr->r_ctl.last_inbound_ts)
6122 	 * 4) The time that the packet that generated that ack was sent (bbr->r_ctl.cur_rtt_send_time)
6123 	 *
6124 	 * Now we can calculate the time between the sends by doing:
6125 	 *
6126 	 * delta = bbr->r_ctl.cur_rtt_send_time - bbr->r_ctl.bbr_ts_check_our_cts
6127 	 *
6128 	 * And the peer's time between receiving them by doing:
6129 	 *
6130 	 * peer_delta = bbr->r_ctl.last_inbound_ts - bbr->r_ctl.bbr_ts_check_tstmp
6131 	 *
6132 	 * We want to figure out if the timestamp values are in msec, 10msec or usec.
6133 	 * We also may find that we can't use the timestamps if say we see
6134 	 * that the peer_delta indicates that though we may have taken 10ms to
6135 	 * pace out the data, it only saw 1ms between the two packets. This would
6136 	 * indicate that somewhere on the path is a batching entity that is giving
6137 	 * out time-slices of the actual b/w. This would mean we could not use
6138 	 * reliably the peers timestamps.
6139 	 *
6140 	 * We expect delta > peer_delta initially. Until we figure out the
6141 	 * timestamp difference which we will store in bbr->r_ctl.bbr_peer_tsratio.
6142 	 * If we place 1000 there then its a ms vs our usec. If we place 10000 there
6143 	 * then its 10ms vs our usec. If the peer is running a usec clock we would
6144 	 * put a 1 there. If the value is faster then ours, we will disable the
6145 	 * use of timestamps (though we could revist this later if we find it to be not
6146 	 * just an isolated one or two flows)).
6147 	 *
6148 	 * To detect the batching middle boxes we will come up with our compensation and
6149 	 * if with it in place, we find the peer is drastically off (by some margin) in
6150 	 * the smaller direction, then we will assume the worst case and disable use of timestamps.
6151 	 *
6152 	 */
6153 	uint64_t delta, peer_delta, delta_up;
6154 
6155 	delta = bbr->r_ctl.cur_rtt_send_time - bbr->r_ctl.bbr_ts_check_our_cts;
6156 	if (delta < bbr_min_usec_delta) {
6157 		/*
6158 		 * Have not seen a min amount of time
6159 		 * between our send times so we can
6160 		 * make a determination of the timestamp
6161 		 * yet.
6162 		 */
6163 		return;
6164 	}
6165 	peer_delta = bbr->r_ctl.last_inbound_ts - bbr->r_ctl.bbr_ts_check_tstmp;
6166 	if (peer_delta < bbr_min_peer_delta) {
6167 		/*
6168 		 * We may have enough in the form of
6169 		 * our delta but the peers number
6170 		 * has not changed that much. It could
6171 		 * be its clock ratio is such that
6172 		 * we need more data (10ms tick) or
6173 		 * there may be other compression scenarios
6174 		 * going on. In any event we need the
6175 		 * spread to be larger.
6176 		 */
6177 		return;
6178 	}
6179 	/* Ok lets first see which way our delta is going */
6180 	if (peer_delta > delta) {
6181 		/* Very unlikely, the peer without
6182 		 * compensation shows that it saw
6183 		 * the two sends arrive further apart
6184 		 * then we saw then in micro-seconds.
6185 		 */
6186 		if (peer_delta < (delta + ((delta * (uint64_t)1000)/ (uint64_t)bbr_delta_percent))) {
6187 			/* well it looks like the peer is a micro-second clock. */
6188 			bbr->rc_ts_clock_set = 1;
6189 			bbr->r_ctl.bbr_peer_tsratio = 1;
6190 		} else {
6191 			bbr->rc_ts_cant_be_used = 1;
6192 			bbr->rc_ts_clock_set = 1;
6193 		}
6194 		return;
6195 	}
6196 	/* Ok we know that the peer_delta is smaller than our send distance */
6197 	bbr->rc_ts_clock_set = 1;
6198 	/* First question is it within the percentage that they are using usec time? */
6199 	delta_up = (peer_delta * 1000) / (uint64_t)bbr_delta_percent;
6200 	if ((peer_delta + delta_up) >= delta) {
6201 		/* Its a usec clock */
6202 		bbr->r_ctl.bbr_peer_tsratio = 1;
6203 		bbr_log_tstmp_validation(bbr, peer_delta, delta);
6204 		return;
6205 	}
6206 	/* Ok if not usec, what about 10usec (though unlikely)? */
6207 	delta_up = (peer_delta * 1000 * 10) / (uint64_t)bbr_delta_percent;
6208 	if (((peer_delta * 10) + delta_up) >= delta) {
6209 		bbr->r_ctl.bbr_peer_tsratio = 10;
6210 		bbr_log_tstmp_validation(bbr, peer_delta, delta);
6211 		return;
6212 	}
6213 	/* And what about 100usec (though again unlikely)? */
6214 	delta_up = (peer_delta * 1000 * 100) / (uint64_t)bbr_delta_percent;
6215 	if (((peer_delta * 100) + delta_up) >= delta) {
6216 		bbr->r_ctl.bbr_peer_tsratio = 100;
6217 		bbr_log_tstmp_validation(bbr, peer_delta, delta);
6218 		return;
6219 	}
6220 	/* And how about 1 msec (the most likely one)? */
6221 	delta_up = (peer_delta * 1000 * 1000) / (uint64_t)bbr_delta_percent;
6222 	if (((peer_delta * 1000) + delta_up) >= delta) {
6223 		bbr->r_ctl.bbr_peer_tsratio = 1000;
6224 		bbr_log_tstmp_validation(bbr, peer_delta, delta);
6225 		return;
6226 	}
6227 	/* Ok if not msec could it be 10 msec? */
6228 	delta_up = (peer_delta * 1000 * 10000) / (uint64_t)bbr_delta_percent;
6229 	if (((peer_delta * 10000) + delta_up) >= delta) {
6230 		bbr->r_ctl.bbr_peer_tsratio = 10000;
6231 		return;
6232 	}
6233 	/* If we fall down here the clock tick so slowly we can't use it */
6234 	bbr->rc_ts_cant_be_used = 1;
6235 	bbr->r_ctl.bbr_peer_tsratio = 0;
6236 	bbr_log_tstmp_validation(bbr, peer_delta, delta);
6237 }
6238 
6239 /*
6240  * Collect new round-trip time estimate
6241  * and update averages and current timeout.
6242  */
6243 static void
6244 tcp_bbr_xmit_timer_commit(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t cts)
6245 {
6246 	int32_t delta;
6247 	uint32_t rtt, tsin;
6248 	int32_t rtt_ticks;
6249 
6250 	if (bbr->rtt_valid == 0)
6251 		/* No valid sample */
6252 		return;
6253 
6254 	rtt = bbr->r_ctl.cur_rtt;
6255 	tsin = bbr->r_ctl.ts_in;
6256 	if (bbr->rc_prtt_set_ts) {
6257 		/*
6258 		 * We are to force feed the rttProp filter due
6259 		 * to an entry into PROBE_RTT. This assures
6260 		 * that the times are sync'd between when we
6261 		 * go into PROBE_RTT and the filter expiration.
6262 		 *
6263 		 * Google does not use a true filter, so they do
6264 		 * this implicitly since they only keep one value
6265 		 * and when they enter probe-rtt they update the
6266 		 * value to the newest rtt.
6267 		 */
6268 		uint32_t rtt_prop;
6269 
6270 		bbr->rc_prtt_set_ts = 0;
6271 		rtt_prop = get_filter_value_small(&bbr->r_ctl.rc_rttprop);
6272 		if (rtt > rtt_prop)
6273 			filter_increase_by_small(&bbr->r_ctl.rc_rttprop, (rtt - rtt_prop), cts);
6274 		else
6275 			apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, cts);
6276 	}
6277 #ifdef STATS
6278 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_PATHRTT, imax(0, rtt));
6279 #endif
6280 	if (bbr->rc_ack_was_delayed)
6281 		rtt += bbr->r_ctl.rc_ack_hdwr_delay;
6282 
6283 	if (rtt < bbr->r_ctl.rc_lowest_rtt)
6284 		bbr->r_ctl.rc_lowest_rtt = rtt;
6285 	bbr_log_rtt_sample(bbr, rtt, tsin);
6286 	if (bbr->r_init_rtt) {
6287 		/*
6288 		 * The initial rtt is not-trusted, nuke it and lets get
6289 		 * our first valid measurement in.
6290 		 */
6291 		bbr->r_init_rtt = 0;
6292 		tp->t_srtt = 0;
6293 	}
6294 	if ((bbr->rc_ts_clock_set == 0) && bbr->rc_ts_valid) {
6295 		/*
6296 		 * So we have not yet figured out
6297 		 * what the peers TSTMP value is
6298 		 * in (most likely ms). We need a
6299 		 * series of cum-ack's to determine
6300 		 * this reliably.
6301 		 */
6302 		if (bbr->rc_ack_is_cumack) {
6303 			if (bbr->rc_ts_data_set) {
6304 				/* Lets attempt to determine the timestamp granularity. */
6305 				bbr_make_timestamp_determination(bbr);
6306 			} else {
6307 				bbr->rc_ts_data_set = 1;
6308 				bbr->r_ctl.bbr_ts_check_tstmp = bbr->r_ctl.last_inbound_ts;
6309 				bbr->r_ctl.bbr_ts_check_our_cts = bbr->r_ctl.cur_rtt_send_time;
6310 			}
6311 		} else {
6312 			/*
6313 			 * We have to have consecutive acks
6314 			 * reset any "filled" state to none.
6315 			 */
6316 			bbr->rc_ts_data_set = 0;
6317 		}
6318 	}
6319 	/* Round it up */
6320 	rtt_ticks = USEC_2_TICKS((rtt + (USECS_IN_MSEC - 1)));
6321 	if (tp->t_srtt != 0) {
6322 		/*
6323 		 * srtt is stored as fixed point with 5 bits after the
6324 		 * binary point (i.e., scaled by 8).  The following magic is
6325 		 * equivalent to the smoothing algorithm in rfc793 with an
6326 		 * alpha of .875 (srtt = rtt/8 + srtt*7/8 in fixed point).
6327 		 * Adjust rtt to origin 0.
6328 		 */
6329 
6330 		delta = ((rtt_ticks - 1) << TCP_DELTA_SHIFT)
6331 		    - (tp->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT));
6332 
6333 		tp->t_srtt += delta;
6334 		if (tp->t_srtt <= 0)
6335 			tp->t_srtt = 1;
6336 
6337 		/*
6338 		 * We accumulate a smoothed rtt variance (actually, a
6339 		 * smoothed mean difference), then set the retransmit timer
6340 		 * to smoothed rtt + 4 times the smoothed variance. rttvar
6341 		 * is stored as fixed point with 4 bits after the binary
6342 		 * point (scaled by 16).  The following is equivalent to
6343 		 * rfc793 smoothing with an alpha of .75 (rttvar =
6344 		 * rttvar*3/4 + |delta| / 4).  This replaces rfc793's
6345 		 * wired-in beta.
6346 		 */
6347 		if (delta < 0)
6348 			delta = -delta;
6349 		delta -= tp->t_rttvar >> (TCP_RTTVAR_SHIFT - TCP_DELTA_SHIFT);
6350 		tp->t_rttvar += delta;
6351 		if (tp->t_rttvar <= 0)
6352 			tp->t_rttvar = 1;
6353 	} else {
6354 		/*
6355 		 * No rtt measurement yet - use the unsmoothed rtt. Set the
6356 		 * variance to half the rtt (so our first retransmit happens
6357 		 * at 3*rtt).
6358 		 */
6359 		tp->t_srtt = rtt_ticks << TCP_RTT_SHIFT;
6360 		tp->t_rttvar = rtt_ticks << (TCP_RTTVAR_SHIFT - 1);
6361 	}
6362 	KMOD_TCPSTAT_INC(tcps_rttupdated);
6363 	if (tp->t_rttupdated < UCHAR_MAX)
6364 		tp->t_rttupdated++;
6365 #ifdef STATS
6366 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rtt_ticks));
6367 #endif
6368 	/*
6369 	 * the retransmit should happen at rtt + 4 * rttvar. Because of the
6370 	 * way we do the smoothing, srtt and rttvar will each average +1/2
6371 	 * tick of bias.  When we compute the retransmit timer, we want 1/2
6372 	 * tick of rounding and 1 extra tick because of +-1/2 tick
6373 	 * uncertainty in the firing of the timer.  The bias will give us
6374 	 * exactly the 1.5 tick we need.  But, because the bias is
6375 	 * statistical, we have to test that we don't drop below the minimum
6376 	 * feasible timer (which is 2 ticks).
6377 	 */
6378 	TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp),
6379 	    max(MSEC_2_TICKS(bbr->r_ctl.rc_min_rto_ms), rtt_ticks + 2),
6380 	    MSEC_2_TICKS(((uint32_t)bbr->rc_max_rto_sec) * 1000));
6381 
6382 	/*
6383 	 * We received an ack for a packet that wasn't retransmitted; it is
6384 	 * probably safe to discard any error indications we've received
6385 	 * recently.  This isn't quite right, but close enough for now (a
6386 	 * route might have failed after we sent a segment, and the return
6387 	 * path might not be symmetrical).
6388 	 */
6389 	tp->t_softerror = 0;
6390 	rtt = (TICKS_2_USEC(bbr->rc_tp->t_srtt) >> TCP_RTT_SHIFT);
6391 	if (bbr->r_ctl.bbr_smallest_srtt_this_state > rtt)
6392 		bbr->r_ctl.bbr_smallest_srtt_this_state = rtt;
6393 }
6394 
6395 static void
6396 bbr_set_reduced_rtt(struct tcp_bbr *bbr, uint32_t cts, uint32_t line)
6397 {
6398 	bbr->r_ctl.rc_rtt_shrinks = cts;
6399 	if (bbr_can_force_probertt &&
6400 	    (TSTMP_GT(cts, bbr->r_ctl.last_in_probertt)) &&
6401 	    ((cts - bbr->r_ctl.last_in_probertt) > bbr->r_ctl.rc_probertt_int)) {
6402 		/*
6403 		 * We should enter probe-rtt its been too long
6404 		 * since we have been there.
6405 		 */
6406 		bbr_enter_probe_rtt(bbr, cts, __LINE__);
6407 	} else
6408 		bbr_check_probe_rtt_limits(bbr, cts);
6409 }
6410 
6411 static void
6412 tcp_bbr_commit_bw(struct tcp_bbr *bbr, uint32_t cts)
6413 {
6414 	uint64_t orig_bw;
6415 
6416 	if (bbr->r_ctl.rc_bbr_cur_del_rate == 0) {
6417 		/* We never apply a zero measurement */
6418 		bbr_log_type_bbrupd(bbr, 20, cts, 0, 0,
6419 				    0, 0, 0, 0, 0, 0);
6420 		return;
6421 	}
6422 	if (bbr->r_ctl.r_measurement_count < 0xffffffff)
6423 		bbr->r_ctl.r_measurement_count++;
6424 	orig_bw = get_filter_value(&bbr->r_ctl.rc_delrate);
6425 	apply_filter_max(&bbr->r_ctl.rc_delrate, bbr->r_ctl.rc_bbr_cur_del_rate, bbr->r_ctl.rc_pkt_epoch);
6426 	bbr_log_type_bbrupd(bbr, 21, cts, (uint32_t)orig_bw,
6427 			    (uint32_t)get_filter_value(&bbr->r_ctl.rc_delrate),
6428 			    0, 0, 0, 0, 0, 0);
6429 	if (orig_bw &&
6430 	    (orig_bw != get_filter_value(&bbr->r_ctl.rc_delrate))) {
6431 		if (bbr->bbr_hdrw_pacing) {
6432 			/*
6433 			 * Apply a new rate to the hardware
6434 			 * possibly.
6435 			 */
6436 			bbr_update_hardware_pacing_rate(bbr, cts);
6437 		}
6438 		bbr_set_state_target(bbr, __LINE__);
6439 		tcp_bbr_tso_size_check(bbr, cts);
6440 		if (bbr->r_recovery_bw)  {
6441 			bbr_setup_red_bw(bbr, cts);
6442 			bbr_log_type_bw_reduce(bbr, BBR_RED_BW_USELRBW);
6443 		}
6444 	} else if ((orig_bw == 0) && get_filter_value(&bbr->r_ctl.rc_delrate))
6445 		tcp_bbr_tso_size_check(bbr, cts);
6446 }
6447 
6448 static void
6449 bbr_nf_measurement(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, uint32_t rtt, uint32_t cts)
6450 {
6451 	if (bbr->rc_in_persist == 0) {
6452 		/* We log only when not in persist */
6453 		/* Translate to a Bytes Per Second */
6454 		uint64_t tim, bw, ts_diff, ts_bw;
6455 		uint32_t delivered;
6456 
6457 		if (TSTMP_GT(bbr->r_ctl.rc_del_time, rsm->r_del_time))
6458 			tim = (uint64_t)(bbr->r_ctl.rc_del_time - rsm->r_del_time);
6459 		else
6460 			tim = 1;
6461 		/*
6462 		 * Now that we have processed the tim (skipping the sample
6463 		 * or possibly updating the time, go ahead and
6464 		 * calculate the cdr.
6465 		 */
6466 		delivered = (bbr->r_ctl.rc_delivered - rsm->r_delivered);
6467 		bw = (uint64_t)delivered;
6468 		bw *= (uint64_t)USECS_IN_SECOND;
6469 		bw /= tim;
6470 		if (bw == 0) {
6471 			/* We must have a calculatable amount */
6472 			return;
6473 		}
6474 		/*
6475 		 * If we are using this b/w shove it in now so we
6476 		 * can see in the trace viewer if it gets over-ridden.
6477 		 */
6478 		if (rsm->r_ts_valid &&
6479 		    bbr->rc_ts_valid &&
6480 		    bbr->rc_ts_clock_set &&
6481 		    (bbr->rc_ts_cant_be_used == 0) &&
6482 		    bbr->rc_use_ts_limit) {
6483 			ts_diff = max((bbr->r_ctl.last_inbound_ts - rsm->r_del_ack_ts), 1);
6484 			ts_diff *= bbr->r_ctl.bbr_peer_tsratio;
6485 			if ((delivered == 0) ||
6486 			    (rtt < 1000)) {
6487 				/* Can't use the ts */
6488 				bbr_log_type_bbrupd(bbr, 61, cts,
6489 						    ts_diff,
6490 						    bbr->r_ctl.last_inbound_ts,
6491 						    rsm->r_del_ack_ts, 0,
6492 						    0, 0, 0, delivered);
6493 			} else {
6494 				ts_bw = (uint64_t)delivered;
6495 				ts_bw *= (uint64_t)USECS_IN_SECOND;
6496 				ts_bw /= ts_diff;
6497 				bbr_log_type_bbrupd(bbr, 62, cts,
6498 						    (ts_bw >> 32),
6499 						    (ts_bw & 0xffffffff), 0, 0,
6500 						    0, 0, ts_diff, delivered);
6501 				if ((bbr->ts_can_raise) &&
6502 				    (ts_bw > bw)) {
6503 					bbr_log_type_bbrupd(bbr, 8, cts,
6504 							    delivered,
6505 							    ts_diff,
6506 							    (bw >> 32),
6507 							    (bw & 0x00000000ffffffff),
6508 							    0, 0, 0, 0);
6509 					bw = ts_bw;
6510 				} else if (ts_bw && (ts_bw < bw)) {
6511 					bbr_log_type_bbrupd(bbr, 7, cts,
6512 							    delivered,
6513 							    ts_diff,
6514 							    (bw >> 32),
6515 							    (bw & 0x00000000ffffffff),
6516 							    0, 0, 0, 0);
6517 					bw = ts_bw;
6518 				}
6519 			}
6520 		}
6521 		if (rsm->r_first_sent_time &&
6522 		    TSTMP_GT(rsm->r_tim_lastsent[(rsm->r_rtr_cnt -1)],rsm->r_first_sent_time)) {
6523 			uint64_t sbw, sti;
6524 			/*
6525 			 * We use what was in flight at the time of our
6526 			 * send  and the size of this send to figure
6527 			 * out what we have been sending at (amount).
6528 			 * For the time we take from the time of
6529 			 * the send of the first send outstanding
6530 			 * until this send plus this sends pacing
6531 			 * time. This gives us a good calculation
6532 			 * as to the rate we have been sending at.
6533 			 */
6534 
6535 			sbw = (uint64_t)(rsm->r_flight_at_send);
6536 			sbw *= (uint64_t)USECS_IN_SECOND;
6537 			sti = rsm->r_tim_lastsent[(rsm->r_rtr_cnt -1)] - rsm->r_first_sent_time;
6538 			sti += rsm->r_pacing_delay;
6539 			sbw /= sti;
6540 			if (sbw < bw) {
6541 				bbr_log_type_bbrupd(bbr, 6, cts,
6542 						    delivered,
6543 						    (uint32_t)sti,
6544 						    (bw >> 32),
6545 						    (uint32_t)bw,
6546 						    rsm->r_first_sent_time, 0, (sbw >> 32),
6547 						    (uint32_t)sbw);
6548 				bw = sbw;
6549 			}
6550 		}
6551 		/* Use the google algorithm for b/w measurements */
6552 		bbr->r_ctl.rc_bbr_cur_del_rate = bw;
6553 		if ((rsm->r_app_limited == 0) ||
6554 		    (bw > get_filter_value(&bbr->r_ctl.rc_delrate))) {
6555 			tcp_bbr_commit_bw(bbr, cts);
6556 			bbr_log_type_bbrupd(bbr, 10, cts, (uint32_t)tim, delivered,
6557 					    0, 0, 0, 0,  bbr->r_ctl.rc_del_time,  rsm->r_del_time);
6558 		}
6559 	}
6560 }
6561 
6562 static void
6563 bbr_google_measurement(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, uint32_t rtt, uint32_t cts)
6564 {
6565 	if (bbr->rc_in_persist == 0) {
6566 		/* We log only when not in persist */
6567 		/* Translate to a Bytes Per Second */
6568 		uint64_t tim, bw;
6569 		uint32_t delivered;
6570 		int no_apply = 0;
6571 
6572 		if (TSTMP_GT(bbr->r_ctl.rc_del_time, rsm->r_del_time))
6573 			tim = (uint64_t)(bbr->r_ctl.rc_del_time - rsm->r_del_time);
6574 		else
6575 			tim = 1;
6576 		/*
6577 		 * Now that we have processed the tim (skipping the sample
6578 		 * or possibly updating the time, go ahead and
6579 		 * calculate the cdr.
6580 		 */
6581 		delivered = (bbr->r_ctl.rc_delivered - rsm->r_delivered);
6582 		bw = (uint64_t)delivered;
6583 		bw *= (uint64_t)USECS_IN_SECOND;
6584 		bw /= tim;
6585 		if (tim < bbr->r_ctl.rc_lowest_rtt) {
6586 			bbr_log_type_bbrupd(bbr, 99, cts, (uint32_t)tim, delivered,
6587 					    tim, bbr->r_ctl.rc_lowest_rtt, 0, 0, 0, 0);
6588 
6589 			no_apply = 1;
6590 		}
6591 		/*
6592 		 * If we are using this b/w shove it in now so we
6593 		 * can see in the trace viewer if it gets over-ridden.
6594 		 */
6595 		bbr->r_ctl.rc_bbr_cur_del_rate = bw;
6596 		/* Gate by the sending rate */
6597 		if (rsm->r_first_sent_time &&
6598 		    TSTMP_GT(rsm->r_tim_lastsent[(rsm->r_rtr_cnt -1)],rsm->r_first_sent_time)) {
6599 			uint64_t sbw, sti;
6600 			/*
6601 			 * We use what was in flight at the time of our
6602 			 * send  and the size of this send to figure
6603 			 * out what we have been sending at (amount).
6604 			 * For the time we take from the time of
6605 			 * the send of the first send outstanding
6606 			 * until this send plus this sends pacing
6607 			 * time. This gives us a good calculation
6608 			 * as to the rate we have been sending at.
6609 			 */
6610 
6611 			sbw = (uint64_t)(rsm->r_flight_at_send);
6612 			sbw *= (uint64_t)USECS_IN_SECOND;
6613 			sti = rsm->r_tim_lastsent[(rsm->r_rtr_cnt -1)] - rsm->r_first_sent_time;
6614 			sti += rsm->r_pacing_delay;
6615 			sbw /= sti;
6616 			if (sbw < bw) {
6617 				bbr_log_type_bbrupd(bbr, 6, cts,
6618 						    delivered,
6619 						    (uint32_t)sti,
6620 						    (bw >> 32),
6621 						    (uint32_t)bw,
6622 						    rsm->r_first_sent_time, 0, (sbw >> 32),
6623 						    (uint32_t)sbw);
6624 				bw = sbw;
6625 			}
6626 			if ((sti > tim) &&
6627 			    (sti < bbr->r_ctl.rc_lowest_rtt)) {
6628 				bbr_log_type_bbrupd(bbr, 99, cts, (uint32_t)tim, delivered,
6629 						    (uint32_t)sti, bbr->r_ctl.rc_lowest_rtt, 0, 0, 0, 0);
6630 				no_apply = 1;
6631 			} else
6632 				no_apply = 0;
6633 		}
6634 		bbr->r_ctl.rc_bbr_cur_del_rate = bw;
6635 		if ((no_apply == 0) &&
6636 		    ((rsm->r_app_limited == 0) ||
6637 		     (bw > get_filter_value(&bbr->r_ctl.rc_delrate)))) {
6638 			tcp_bbr_commit_bw(bbr, cts);
6639 			bbr_log_type_bbrupd(bbr, 10, cts, (uint32_t)tim, delivered,
6640 					    0, 0, 0, 0, bbr->r_ctl.rc_del_time,  rsm->r_del_time);
6641 		}
6642 	}
6643 }
6644 
6645 static void
6646 bbr_update_bbr_info(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, uint32_t rtt, uint32_t cts, uint32_t tsin,
6647     uint32_t uts, int32_t match, uint32_t rsm_send_time, int32_t ack_type, struct tcpopt *to)
6648 {
6649 	uint64_t old_rttprop;
6650 
6651 	/* Update our delivery time and amount */
6652 	bbr->r_ctl.rc_delivered += (rsm->r_end - rsm->r_start);
6653 	bbr->r_ctl.rc_del_time = cts;
6654 	if (rtt == 0) {
6655 		/*
6656 		 * 0 means its a retransmit, for now we don't use these for
6657 		 * the rest of BBR.
6658 		 */
6659 		return;
6660 	}
6661 	if ((bbr->rc_use_google == 0) &&
6662 	    (match != BBR_RTT_BY_EXACTMATCH) &&
6663 	    (match != BBR_RTT_BY_TIMESTAMP)){
6664 		/*
6665 		 * We get a lot of rtt updates, lets not pay attention to
6666 		 * any that are not an exact match. That way we don't have
6667 		 * to worry about timestamps and the whole nonsense of
6668 		 * unsure if its a retransmission etc (if we ever had the
6669 		 * timestamp fixed to always have the last thing sent this
6670 		 * would not be a issue).
6671 		 */
6672 		return;
6673 	}
6674 	if ((bbr_no_retran && bbr->rc_use_google) &&
6675 	    (match != BBR_RTT_BY_EXACTMATCH) &&
6676 	    (match != BBR_RTT_BY_TIMESTAMP)){
6677 		/*
6678 		 * We only do measurements in google mode
6679 		 * with bbr_no_retran on for sure things.
6680 		 */
6681 		return;
6682 	}
6683 	/* Only update srtt if we know by exact match */
6684 	tcp_bbr_xmit_timer(bbr, rtt, rsm_send_time, rsm->r_start, tsin);
6685 	if (ack_type == BBR_CUM_ACKED)
6686 		bbr->rc_ack_is_cumack = 1;
6687 	else
6688 		bbr->rc_ack_is_cumack = 0;
6689 	old_rttprop = bbr_get_rtt(bbr, BBR_RTT_PROP);
6690 	/*
6691 	 * Note the following code differs to the original
6692 	 * BBR spec. It calls for <= not <. However after a
6693 	 * long discussion in email with Neal, he acknowledged
6694 	 * that it should be < than so that we will have flows
6695 	 * going into probe-rtt (we were seeing cases where that
6696 	 * did not happen and caused ugly things to occur). We
6697 	 * have added this agreed upon fix to our code base.
6698 	 */
6699 	if (rtt < old_rttprop) {
6700 		/* Update when we last saw a rtt drop */
6701 		bbr_log_rtt_shrinks(bbr, cts, 0, rtt, __LINE__, BBR_RTTS_NEWRTT, 0);
6702 		bbr_set_reduced_rtt(bbr, cts, __LINE__);
6703 	}
6704 	bbr_log_type_bbrrttprop(bbr, rtt, rsm->r_end, uts, cts,
6705 	    match, rsm->r_start, rsm->r_flags);
6706 	apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, cts);
6707 	if (old_rttprop != bbr_get_rtt(bbr, BBR_RTT_PROP)) {
6708 		/*
6709 		 * The RTT-prop moved, reset the target (may be a
6710 		 * nop for some states).
6711 		 */
6712 		bbr_set_state_target(bbr, __LINE__);
6713 		if (bbr->rc_bbr_state == BBR_STATE_PROBE_RTT)
6714 			bbr_log_rtt_shrinks(bbr, cts, 0, 0,
6715 					    __LINE__, BBR_RTTS_NEW_TARGET, 0);
6716 		else if (old_rttprop < bbr_get_rtt(bbr, BBR_RTT_PROP))
6717 			/* It went up */
6718 			bbr_check_probe_rtt_limits(bbr, cts);
6719 	}
6720 	if ((bbr->rc_use_google == 0) &&
6721 	    (match == BBR_RTT_BY_TIMESTAMP)) {
6722 		/*
6723 		 * We don't do b/w update with
6724 		 * these since they are not really
6725 		 * reliable.
6726 		 */
6727 		return;
6728 	}
6729 	if (bbr->r_ctl.r_app_limited_until &&
6730 	    (bbr->r_ctl.rc_delivered >= bbr->r_ctl.r_app_limited_until)) {
6731 		/* We are no longer app-limited */
6732 		bbr->r_ctl.r_app_limited_until = 0;
6733 	}
6734 	if (bbr->rc_use_google) {
6735 		bbr_google_measurement(bbr, rsm, rtt, cts);
6736 	} else {
6737 		bbr_nf_measurement(bbr, rsm, rtt, cts);
6738 	}
6739 }
6740 
6741 /*
6742  * Convert a timestamp that the main stack
6743  * uses (milliseconds) into one that bbr uses
6744  * (microseconds). Return that converted timestamp.
6745  */
6746 static uint32_t
6747 bbr_ts_convert(uint32_t cts) {
6748 	uint32_t sec, msec;
6749 
6750 	sec = cts / MS_IN_USEC;
6751 	msec = cts - (MS_IN_USEC * sec);
6752 	return ((sec * USECS_IN_SECOND) + (msec * MS_IN_USEC));
6753 }
6754 
6755 /*
6756  * Return 0 if we did not update the RTT time, return
6757  * 1 if we did.
6758  */
6759 static int
6760 bbr_update_rtt(struct tcpcb *tp, struct tcp_bbr *bbr,
6761     struct bbr_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, uint32_t th_ack)
6762 {
6763 	int32_t i;
6764 	uint32_t t, uts = 0;
6765 
6766 	if ((rsm->r_flags & BBR_ACKED) ||
6767 	    (rsm->r_flags & BBR_WAS_RENEGED) ||
6768 	    (rsm->r_flags & BBR_RXT_CLEARED)) {
6769 		/* Already done */
6770 		return (0);
6771 	}
6772 	if (rsm->r_rtt_not_allowed) {
6773 		/* Not allowed */
6774 		return (0);
6775 	}
6776 	if (rsm->r_rtr_cnt == 1) {
6777 		/*
6778 		 * Only one transmit. Hopefully the normal case.
6779 		 */
6780 		if (TSTMP_GT(cts, rsm->r_tim_lastsent[0]))
6781 			t = cts - rsm->r_tim_lastsent[0];
6782 		else
6783 			t = 1;
6784 		bbr->r_ctl.rc_last_rtt = t;
6785 		bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, 0,
6786 				    BBR_RTT_BY_EXACTMATCH, rsm->r_tim_lastsent[0], ack_type, to);
6787 		return (1);
6788 	}
6789 	/* Convert to usecs */
6790 	if ((bbr_can_use_ts_for_rtt == 1) &&
6791 	    (bbr->rc_use_google == 1) &&
6792 	    (ack_type == BBR_CUM_ACKED) &&
6793 	    (to->to_flags & TOF_TS) &&
6794 	    (to->to_tsecr != 0)) {
6795 		t = tcp_tv_to_mssectick(&bbr->rc_tv) - to->to_tsecr;
6796 		if (t < 1)
6797 			t = 1;
6798 		t *= MS_IN_USEC;
6799 		bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, 0,
6800 				    BBR_RTT_BY_TIMESTAMP,
6801 				    rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)],
6802 				    ack_type, to);
6803 		return (1);
6804 	}
6805 	uts = bbr_ts_convert(to->to_tsecr);
6806 	if ((to->to_flags & TOF_TS) &&
6807 	    (to->to_tsecr != 0) &&
6808 	    (ack_type == BBR_CUM_ACKED) &&
6809 	    ((rsm->r_flags & BBR_OVERMAX) == 0)) {
6810 		/*
6811 		 * Now which timestamp does it match? In this block the ACK
6812 		 * may be coming from a previous transmission.
6813 		 */
6814 		uint32_t fudge;
6815 
6816 		fudge = BBR_TIMER_FUDGE;
6817 		for (i = 0; i < rsm->r_rtr_cnt; i++) {
6818 			if ((SEQ_GEQ(uts, (rsm->r_tim_lastsent[i] - fudge))) &&
6819 			    (SEQ_LEQ(uts, (rsm->r_tim_lastsent[i] + fudge)))) {
6820 				if (TSTMP_GT(cts, rsm->r_tim_lastsent[i]))
6821 					t = cts - rsm->r_tim_lastsent[i];
6822 				else
6823 					t = 1;
6824 				bbr->r_ctl.rc_last_rtt = t;
6825 				bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, uts, BBR_RTT_BY_TSMATCHING,
6826 						    rsm->r_tim_lastsent[i], ack_type, to);
6827 				if ((i + 1) < rsm->r_rtr_cnt) {
6828 					/* Likely */
6829 					return (0);
6830 				} else if (rsm->r_flags & BBR_TLP) {
6831 					bbr->rc_tlp_rtx_out = 0;
6832 				}
6833 				return (1);
6834 			}
6835 		}
6836 		/* Fall through if we can't find a matching timestamp */
6837 	}
6838 	/*
6839 	 * Ok its a SACK block that we retransmitted. or a windows
6840 	 * machine without timestamps. We can tell nothing from the
6841 	 * time-stamp since its not there or the time the peer last
6842 	 * received a segment that moved forward its cum-ack point.
6843 	 *
6844 	 * Lets look at the last retransmit and see what we can tell
6845 	 * (with BBR for space we only keep 2 note we have to keep
6846 	 * at least 2 so the map can not be condensed more).
6847 	 */
6848 	i = rsm->r_rtr_cnt - 1;
6849 	if (TSTMP_GT(cts, rsm->r_tim_lastsent[i]))
6850 		t = cts - rsm->r_tim_lastsent[i];
6851 	else
6852 		goto not_sure;
6853 	if (t < bbr->r_ctl.rc_lowest_rtt) {
6854 		/*
6855 		 * We retransmitted and the ack came back in less
6856 		 * than the smallest rtt we have observed in the
6857 		 * windowed rtt. We most likey did an improper
6858 		 * retransmit as outlined in 4.2 Step 3 point 2 in
6859 		 * the rack-draft.
6860 		 *
6861 		 * Use the prior transmission to update all the
6862 		 * information as long as there is only one prior
6863 		 * transmission.
6864 		 */
6865 		if ((rsm->r_flags & BBR_OVERMAX) == 0) {
6866 #ifdef BBR_INVARIANTS
6867 			if (rsm->r_rtr_cnt == 1)
6868 				panic("rsm:%p bbr:%p rsm has overmax and only 1 retranmit flags:%x?", rsm, bbr, rsm->r_flags);
6869 #endif
6870 			i = rsm->r_rtr_cnt - 2;
6871 			if (TSTMP_GT(cts, rsm->r_tim_lastsent[i]))
6872 				t = cts - rsm->r_tim_lastsent[i];
6873 			else
6874 				t = 1;
6875 			bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, uts, BBR_RTT_BY_EARLIER_RET,
6876 					    rsm->r_tim_lastsent[i], ack_type, to);
6877 			return (0);
6878 		} else {
6879 			/*
6880 			 * Too many prior transmissions, just
6881 			 * updated BBR delivered
6882 			 */
6883 not_sure:
6884 			bbr_update_bbr_info(bbr, rsm, 0, cts, to->to_tsecr, uts,
6885 					    BBR_RTT_BY_SOME_RETRAN, 0, ack_type, to);
6886 		}
6887 	} else {
6888 		/*
6889 		 * We retransmitted it and the retransmit did the
6890 		 * job.
6891 		 */
6892 		if (rsm->r_flags & BBR_TLP)
6893 			bbr->rc_tlp_rtx_out = 0;
6894 		if ((rsm->r_flags & BBR_OVERMAX) == 0)
6895 			bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, uts,
6896 					    BBR_RTT_BY_THIS_RETRAN, 0, ack_type, to);
6897 		else
6898 			bbr_update_bbr_info(bbr, rsm, 0, cts, to->to_tsecr, uts,
6899 					    BBR_RTT_BY_SOME_RETRAN, 0, ack_type, to);
6900 		return (1);
6901 	}
6902 	return (0);
6903 }
6904 
6905 /*
6906  * Mark the SACK_PASSED flag on all entries prior to rsm send wise.
6907  */
6908 static void
6909 bbr_log_sack_passed(struct tcpcb *tp,
6910     struct tcp_bbr *bbr, struct bbr_sendmap *rsm)
6911 {
6912 	struct bbr_sendmap *nrsm;
6913 
6914 	nrsm = rsm;
6915 	TAILQ_FOREACH_REVERSE_FROM(nrsm, &bbr->r_ctl.rc_tmap,
6916 	    bbr_head, r_tnext) {
6917 		if (nrsm == rsm) {
6918 			/* Skip original segment he is acked */
6919 			continue;
6920 		}
6921 		if (nrsm->r_flags & BBR_ACKED) {
6922 			/* Skip ack'd segments */
6923 			continue;
6924 		}
6925 		if (nrsm->r_flags & BBR_SACK_PASSED) {
6926 			/*
6927 			 * We found one that is already marked
6928 			 * passed, we have been here before and
6929 			 * so all others below this are marked.
6930 			 */
6931 			break;
6932 		}
6933 		BBR_STAT_INC(bbr_sack_passed);
6934 		nrsm->r_flags |= BBR_SACK_PASSED;
6935 		if (((nrsm->r_flags & BBR_MARKED_LOST) == 0) &&
6936 		    bbr_is_lost(bbr, nrsm, bbr->r_ctl.rc_rcvtime)) {
6937 			bbr->r_ctl.rc_lost += nrsm->r_end - nrsm->r_start;
6938 			bbr->r_ctl.rc_lost_bytes += nrsm->r_end - nrsm->r_start;
6939 			nrsm->r_flags |= BBR_MARKED_LOST;
6940 		}
6941 		nrsm->r_flags &= ~BBR_WAS_SACKPASS;
6942 	}
6943 }
6944 
6945 /*
6946  * Returns the number of bytes that were
6947  * newly ack'd by sack blocks.
6948  */
6949 static uint32_t
6950 bbr_proc_sack_blk(struct tcpcb *tp, struct tcp_bbr *bbr, struct sackblk *sack,
6951     struct tcpopt *to, struct bbr_sendmap **prsm, uint32_t cts)
6952 {
6953 	int32_t times = 0;
6954 	uint32_t start, end, changed = 0;
6955 	struct bbr_sendmap *rsm, *nrsm;
6956 	int32_t used_ref = 1;
6957 	uint8_t went_back = 0, went_fwd = 0;
6958 
6959 	start = sack->start;
6960 	end = sack->end;
6961 	rsm = *prsm;
6962 	if (rsm == NULL)
6963 		used_ref = 0;
6964 
6965 	/* Do we locate the block behind where we last were? */
6966 	if (rsm && SEQ_LT(start, rsm->r_start)) {
6967 		went_back = 1;
6968 		TAILQ_FOREACH_REVERSE_FROM(rsm, &bbr->r_ctl.rc_map, bbr_head, r_next) {
6969 			if (SEQ_GEQ(start, rsm->r_start) &&
6970 			    SEQ_LT(start, rsm->r_end)) {
6971 				goto do_rest_ofb;
6972 			}
6973 		}
6974 	}
6975 start_at_beginning:
6976 	went_fwd = 1;
6977 	/*
6978 	 * Ok lets locate the block where this guy is fwd from rsm (if its
6979 	 * set)
6980 	 */
6981 	TAILQ_FOREACH_FROM(rsm, &bbr->r_ctl.rc_map, r_next) {
6982 		if (SEQ_GEQ(start, rsm->r_start) &&
6983 		    SEQ_LT(start, rsm->r_end)) {
6984 			break;
6985 		}
6986 	}
6987 do_rest_ofb:
6988 	if (rsm == NULL) {
6989 		/*
6990 		 * This happens when we get duplicate sack blocks with the
6991 		 * same end. For example SACK 4: 100 SACK 3: 100 The sort
6992 		 * will not change there location so we would just start at
6993 		 * the end of the first one and get lost.
6994 		 */
6995 		if (tp->t_flags & TF_SENTFIN) {
6996 			/*
6997 			 * Check to see if we have not logged the FIN that
6998 			 * went out.
6999 			 */
7000 			nrsm = TAILQ_LAST_FAST(&bbr->r_ctl.rc_map, bbr_sendmap, r_next);
7001 			if (nrsm && (nrsm->r_end + 1) == tp->snd_max) {
7002 				/*
7003 				 * Ok we did not get the FIN logged.
7004 				 */
7005 				nrsm->r_end++;
7006 				rsm = nrsm;
7007 				goto do_rest_ofb;
7008 			}
7009 		}
7010 		if (times == 1) {
7011 #ifdef BBR_INVARIANTS
7012 			panic("tp:%p bbr:%p sack:%p to:%p prsm:%p",
7013 			    tp, bbr, sack, to, prsm);
7014 #else
7015 			goto out;
7016 #endif
7017 		}
7018 		times++;
7019 		BBR_STAT_INC(bbr_sack_proc_restart);
7020 		rsm = NULL;
7021 		goto start_at_beginning;
7022 	}
7023 	/* Ok we have an ACK for some piece of rsm */
7024 	if (rsm->r_start != start) {
7025 		/*
7026 		 * Need to split this in two pieces the before and after.
7027 		 */
7028 		if (bbr_sack_mergable(rsm, start, end))
7029 			nrsm = bbr_alloc_full_limit(bbr);
7030 		else
7031 			nrsm = bbr_alloc_limit(bbr, BBR_LIMIT_TYPE_SPLIT);
7032 		if (nrsm == NULL) {
7033 			/* We could not allocate ignore the sack */
7034 			struct sackblk blk;
7035 
7036 			blk.start = start;
7037 			blk.end = end;
7038 			sack_filter_reject(&bbr->r_ctl.bbr_sf, &blk);
7039 			goto out;
7040 		}
7041 		bbr_clone_rsm(bbr, nrsm, rsm, start);
7042 		TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
7043 		if (rsm->r_in_tmap) {
7044 			TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7045 			nrsm->r_in_tmap = 1;
7046 		}
7047 		rsm->r_flags &= (~BBR_HAS_FIN);
7048 		rsm = nrsm;
7049 	}
7050 	if (SEQ_GEQ(end, rsm->r_end)) {
7051 		/*
7052 		 * The end of this block is either beyond this guy or right
7053 		 * at this guy.
7054 		 */
7055 		if ((rsm->r_flags & BBR_ACKED) == 0) {
7056 			bbr_update_rtt(tp, bbr, rsm, to, cts, BBR_SACKED, 0);
7057 			changed += (rsm->r_end - rsm->r_start);
7058 			bbr->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
7059 			bbr_log_sack_passed(tp, bbr, rsm);
7060 			if (rsm->r_flags & BBR_MARKED_LOST) {
7061 				bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
7062 			}
7063 			/* Is Reordering occuring? */
7064 			if (rsm->r_flags & BBR_SACK_PASSED) {
7065 				BBR_STAT_INC(bbr_reorder_seen);
7066 				bbr->r_ctl.rc_reorder_ts = cts;
7067 				if (rsm->r_flags & BBR_MARKED_LOST) {
7068 					bbr->r_ctl.rc_lost -= rsm->r_end - rsm->r_start;
7069 					if (SEQ_GT(bbr->r_ctl.rc_lt_lost, bbr->r_ctl.rc_lost))
7070 						/* LT sampling also needs adjustment */
7071 						bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
7072 				}
7073 			}
7074 			rsm->r_flags |= BBR_ACKED;
7075 			rsm->r_flags &= ~(BBR_TLP|BBR_WAS_RENEGED|BBR_RXT_CLEARED|BBR_MARKED_LOST);
7076 			if (rsm->r_in_tmap) {
7077 				TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
7078 				rsm->r_in_tmap = 0;
7079 			}
7080 		}
7081 		bbr_isit_a_pkt_epoch(bbr, cts, rsm, __LINE__, BBR_SACKED);
7082 		if (end == rsm->r_end) {
7083 			/* This block only - done */
7084 			goto out;
7085 		}
7086 		/* There is more not coverend by this rsm move on */
7087 		start = rsm->r_end;
7088 		nrsm = TAILQ_NEXT(rsm, r_next);
7089 		rsm = nrsm;
7090 		times = 0;
7091 		goto do_rest_ofb;
7092 	}
7093 	if (rsm->r_flags & BBR_ACKED) {
7094 		/* Been here done that */
7095 		goto out;
7096 	}
7097 	/* Ok we need to split off this one at the tail */
7098 	if (bbr_sack_mergable(rsm, start, end))
7099 		nrsm = bbr_alloc_full_limit(bbr);
7100 	else
7101 		nrsm = bbr_alloc_limit(bbr, BBR_LIMIT_TYPE_SPLIT);
7102 	if (nrsm == NULL) {
7103 		/* failed XXXrrs what can we do but loose the sack info? */
7104 		struct sackblk blk;
7105 
7106 		blk.start = start;
7107 		blk.end = end;
7108 		sack_filter_reject(&bbr->r_ctl.bbr_sf, &blk);
7109 		goto out;
7110 	}
7111 	/* Clone it */
7112 	bbr_clone_rsm(bbr, nrsm, rsm, end);
7113 	/* The sack block does not cover this guy fully */
7114 	rsm->r_flags &= (~BBR_HAS_FIN);
7115 	TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
7116 	if (rsm->r_in_tmap) {
7117 		TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7118 		nrsm->r_in_tmap = 1;
7119 	}
7120 	nrsm->r_dupack = 0;
7121 	bbr_update_rtt(tp, bbr, rsm, to, cts, BBR_SACKED, 0);
7122 	bbr_isit_a_pkt_epoch(bbr, cts, rsm, __LINE__, BBR_SACKED);
7123 	changed += (rsm->r_end - rsm->r_start);
7124 	bbr->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
7125 	bbr_log_sack_passed(tp, bbr, rsm);
7126 	/* Is Reordering occuring? */
7127 	if (rsm->r_flags & BBR_MARKED_LOST) {
7128 		bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
7129 	}
7130 	if (rsm->r_flags & BBR_SACK_PASSED) {
7131 		BBR_STAT_INC(bbr_reorder_seen);
7132 		bbr->r_ctl.rc_reorder_ts = cts;
7133 		if (rsm->r_flags & BBR_MARKED_LOST) {
7134 			bbr->r_ctl.rc_lost -= rsm->r_end - rsm->r_start;
7135 			if (SEQ_GT(bbr->r_ctl.rc_lt_lost, bbr->r_ctl.rc_lost))
7136 				/* LT sampling also needs adjustment */
7137 				bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
7138 		}
7139 	}
7140 	rsm->r_flags &= ~(BBR_TLP|BBR_WAS_RENEGED|BBR_RXT_CLEARED|BBR_MARKED_LOST);
7141 	rsm->r_flags |= BBR_ACKED;
7142 	if (rsm->r_in_tmap) {
7143 		TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
7144 		rsm->r_in_tmap = 0;
7145 	}
7146 out:
7147 	if (rsm && (rsm->r_flags & BBR_ACKED)) {
7148 		/*
7149 		 * Now can we merge this newly acked
7150 		 * block with either the previous or
7151 		 * next block?
7152 		 */
7153 		nrsm = TAILQ_NEXT(rsm, r_next);
7154 		if (nrsm &&
7155 		    (nrsm->r_flags & BBR_ACKED)) {
7156 			/* yep this and next can be merged */
7157 			rsm = bbr_merge_rsm(bbr, rsm, nrsm);
7158 		}
7159 		/* Now what about the previous? */
7160 		nrsm = TAILQ_PREV(rsm, bbr_head, r_next);
7161 		if (nrsm &&
7162 		    (nrsm->r_flags & BBR_ACKED)) {
7163 			/* yep the previous and this can be merged */
7164 			rsm = bbr_merge_rsm(bbr, nrsm, rsm);
7165 		}
7166 	}
7167 	if (used_ref == 0) {
7168 		BBR_STAT_INC(bbr_sack_proc_all);
7169 	} else {
7170 		BBR_STAT_INC(bbr_sack_proc_short);
7171 	}
7172 	if (went_fwd && went_back) {
7173 		BBR_STAT_INC(bbr_sack_search_both);
7174 	} else if (went_fwd) {
7175 		BBR_STAT_INC(bbr_sack_search_fwd);
7176 	} else if (went_back) {
7177 		BBR_STAT_INC(bbr_sack_search_back);
7178 	}
7179 	/* Save off where the next seq is */
7180 	if (rsm)
7181 		bbr->r_ctl.rc_sacklast = TAILQ_NEXT(rsm, r_next);
7182 	else
7183 		bbr->r_ctl.rc_sacklast = NULL;
7184 	*prsm = rsm;
7185 	return (changed);
7186 }
7187 
7188 static void inline
7189 bbr_peer_reneges(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, tcp_seq th_ack)
7190 {
7191 	struct bbr_sendmap *tmap;
7192 
7193 	BBR_STAT_INC(bbr_reneges_seen);
7194 	tmap = NULL;
7195 	while (rsm && (rsm->r_flags & BBR_ACKED)) {
7196 		/* Its no longer sacked, mark it so */
7197 		uint32_t oflags;
7198 		bbr->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
7199 #ifdef BBR_INVARIANTS
7200 		if (rsm->r_in_tmap) {
7201 			panic("bbr:%p rsm:%p flags:0x%x in tmap?",
7202 			    bbr, rsm, rsm->r_flags);
7203 		}
7204 #endif
7205 		oflags = rsm->r_flags;
7206 		if (rsm->r_flags & BBR_MARKED_LOST) {
7207 			bbr->r_ctl.rc_lost -= rsm->r_end - rsm->r_start;
7208 			bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
7209 			if (SEQ_GT(bbr->r_ctl.rc_lt_lost, bbr->r_ctl.rc_lost))
7210 				/* LT sampling also needs adjustment */
7211 				bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
7212 		}
7213 		rsm->r_flags &= ~(BBR_ACKED | BBR_SACK_PASSED | BBR_WAS_SACKPASS | BBR_MARKED_LOST);
7214 		rsm->r_flags |= BBR_WAS_RENEGED;
7215 		rsm->r_flags |= BBR_RXT_CLEARED;
7216 		bbr_log_type_rsmclear(bbr, bbr->r_ctl.rc_rcvtime, rsm, oflags, __LINE__);
7217 		/* Rebuild it into our tmap */
7218 		if (tmap == NULL) {
7219 			TAILQ_INSERT_HEAD(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
7220 			tmap = rsm;
7221 		} else {
7222 			TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, tmap, rsm, r_tnext);
7223 			tmap = rsm;
7224 		}
7225 		tmap->r_in_tmap = 1;
7226 		/*
7227 		 * XXXrrs Delivered? Should we do anything here?
7228 		 *
7229 		 * Of course we don't on a rxt timeout so maybe its ok that
7230 		 * we don't?
7231 		 *
7232 		 * For now lets not.
7233 		 */
7234 		rsm = TAILQ_NEXT(rsm, r_next);
7235 	}
7236 	/*
7237 	 * Now lets possibly clear the sack filter so we start recognizing
7238 	 * sacks that cover this area.
7239 	 */
7240 	sack_filter_clear(&bbr->r_ctl.bbr_sf, th_ack);
7241 }
7242 
7243 static void
7244 bbr_log_syn(struct tcpcb *tp, struct tcpopt *to)
7245 {
7246 	struct tcp_bbr *bbr;
7247 	struct bbr_sendmap *rsm;
7248 	uint32_t cts;
7249 
7250 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
7251 	cts = bbr->r_ctl.rc_rcvtime;
7252 	rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
7253 	if (rsm && (rsm->r_flags & BBR_HAS_SYN)) {
7254 		if ((rsm->r_end - rsm->r_start) <= 1) {
7255 			/* Log out the SYN completely */
7256 			bbr->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
7257 			rsm->r_rtr_bytes = 0;
7258 			TAILQ_REMOVE(&bbr->r_ctl.rc_map, rsm, r_next);
7259 			if (rsm->r_in_tmap) {
7260 				TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
7261 				rsm->r_in_tmap = 0;
7262 			}
7263 			if (bbr->r_ctl.rc_next == rsm) {
7264 				/* scoot along the marker */
7265 				bbr->r_ctl.rc_next = TAILQ_FIRST(&bbr->r_ctl.rc_map);
7266 			}
7267 			if (to != NULL)
7268 				bbr_update_rtt(tp, bbr, rsm, to, cts, BBR_CUM_ACKED, 0);
7269 			bbr_free(bbr, rsm);
7270 		} else {
7271 			/* There is more (Fast open)? strip out SYN. */
7272 			rsm->r_flags &= ~BBR_HAS_SYN;
7273 			rsm->r_start++;
7274 		}
7275 	}
7276 }
7277 
7278 /*
7279  * Returns the number of bytes that were
7280  * acknowledged by SACK blocks.
7281  */
7282 
7283 static uint32_t
7284 bbr_log_ack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th,
7285     uint32_t *prev_acked)
7286 {
7287 	uint32_t changed, last_seq, entered_recovery = 0;
7288 	struct tcp_bbr *bbr;
7289 	struct bbr_sendmap *rsm;
7290 	struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1];
7291 	register uint32_t th_ack;
7292 	int32_t i, j, k, new_sb, num_sack_blks = 0;
7293 	uint32_t cts, acked, ack_point, sack_changed = 0;
7294 	uint32_t p_maxseg, maxseg, p_acked = 0;
7295 
7296 	INP_WLOCK_ASSERT(tptoinpcb(tp));
7297 	if (tcp_get_flags(th) & TH_RST) {
7298 		/* We don't log resets */
7299 		return (0);
7300 	}
7301 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
7302 	cts = bbr->r_ctl.rc_rcvtime;
7303 
7304 	rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
7305 	changed = 0;
7306 	maxseg = tp->t_maxseg - bbr->rc_last_options;
7307 	p_maxseg = min(bbr->r_ctl.rc_pace_max_segs, maxseg);
7308 	th_ack = th->th_ack;
7309 	if (SEQ_GT(th_ack, tp->snd_una)) {
7310 		bbr_log_progress_event(bbr, tp, ticks, PROGRESS_UPDATE, __LINE__);
7311 		bbr->rc_tp->t_acktime = ticks;
7312 	}
7313 	if (SEQ_LEQ(th_ack, tp->snd_una)) {
7314 		/* Only sent here for sack processing */
7315 		goto proc_sack;
7316 	}
7317 	if (rsm && SEQ_GT(th_ack, rsm->r_start)) {
7318 		changed = th_ack - rsm->r_start;
7319 	} else if ((rsm == NULL) && ((th_ack - 1) == tp->iss)) {
7320 		/*
7321 		 * For the SYN incoming case we will not have called
7322 		 * tcp_output for the sending of the SYN, so there will be
7323 		 * no map. All other cases should probably be a panic.
7324 		 */
7325 		if ((to->to_flags & TOF_TS) && (to->to_tsecr != 0)) {
7326 			/*
7327 			 * We have a timestamp that can be used to generate
7328 			 * an initial RTT.
7329 			 */
7330 			uint32_t ts, now, rtt;
7331 
7332 			ts = bbr_ts_convert(to->to_tsecr);
7333 			now = bbr_ts_convert(tcp_tv_to_mssectick(&bbr->rc_tv));
7334 			rtt = now - ts;
7335 			if (rtt < 1)
7336 				rtt = 1;
7337 			bbr_log_type_bbrrttprop(bbr, rtt,
7338 						tp->iss, 0, cts,
7339 						BBR_RTT_BY_TIMESTAMP, tp->iss, 0);
7340 			apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, cts);
7341 			changed = 1;
7342 			bbr->r_wanted_output = 1;
7343 			goto out;
7344 		}
7345 		goto proc_sack;
7346 	} else if (rsm == NULL) {
7347 		goto out;
7348 	}
7349 	if (changed) {
7350 		/*
7351 		 * The ACK point is advancing to th_ack, we must drop off
7352 		 * the packets in the rack log and calculate any eligble
7353 		 * RTT's.
7354 		 */
7355 		bbr->r_wanted_output = 1;
7356 more:
7357 		if (rsm == NULL) {
7358 			if (tp->t_flags & TF_SENTFIN) {
7359 				/* if we send a FIN we will not hav a map */
7360 				goto proc_sack;
7361 			}
7362 #ifdef BBR_INVARIANTS
7363 			panic("No rack map tp:%p for th:%p state:%d bbr:%p snd_una:%u snd_max:%u chg:%d\n",
7364 			    tp,
7365 			    th, tp->t_state, bbr,
7366 			    tp->snd_una, tp->snd_max, changed);
7367 #endif
7368 			goto proc_sack;
7369 		}
7370 	}
7371 	if (SEQ_LT(th_ack, rsm->r_start)) {
7372 		/* Huh map is missing this */
7373 #ifdef BBR_INVARIANTS
7374 		printf("Rack map starts at r_start:%u for th_ack:%u huh? ts:%d rs:%d bbr:%p\n",
7375 		    rsm->r_start,
7376 		    th_ack, tp->t_state,
7377 		    bbr->r_state, bbr);
7378 		panic("th-ack is bad bbr:%p tp:%p", bbr, tp);
7379 #endif
7380 		goto proc_sack;
7381 	} else if (th_ack == rsm->r_start) {
7382 		/* None here to ack */
7383 		goto proc_sack;
7384 	}
7385 	/*
7386 	 * Clear the dup ack counter, it will
7387 	 * either be freed or if there is some
7388 	 * remaining we need to start it at zero.
7389 	 */
7390 	rsm->r_dupack = 0;
7391 	/* Now do we consume the whole thing? */
7392 	if (SEQ_GEQ(th_ack, rsm->r_end)) {
7393 		/* Its all consumed. */
7394 		uint32_t left;
7395 
7396 		if (rsm->r_flags & BBR_ACKED) {
7397 			/*
7398 			 * It was acked on the scoreboard -- remove it from
7399 			 * total
7400 			 */
7401 			p_acked += (rsm->r_end - rsm->r_start);
7402 			bbr->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
7403 			if (bbr->r_ctl.rc_sacked == 0)
7404 				bbr->r_ctl.rc_sacklast = NULL;
7405 		} else {
7406 			bbr_update_rtt(tp, bbr, rsm, to, cts, BBR_CUM_ACKED, th_ack);
7407 			if (rsm->r_flags & BBR_MARKED_LOST) {
7408 				bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
7409 			}
7410 			if (rsm->r_flags & BBR_SACK_PASSED) {
7411 				/*
7412 				 * There are acked segments ACKED on the
7413 				 * scoreboard further up. We are seeing
7414 				 * reordering.
7415 				 */
7416 				BBR_STAT_INC(bbr_reorder_seen);
7417 				bbr->r_ctl.rc_reorder_ts = cts;
7418 				if (rsm->r_flags & BBR_MARKED_LOST) {
7419 					bbr->r_ctl.rc_lost -= rsm->r_end - rsm->r_start;
7420 					if (SEQ_GT(bbr->r_ctl.rc_lt_lost, bbr->r_ctl.rc_lost))
7421 						/* LT sampling also needs adjustment */
7422 						bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
7423 				}
7424 			}
7425 			rsm->r_flags &= ~BBR_MARKED_LOST;
7426 		}
7427 		bbr->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
7428 		rsm->r_rtr_bytes = 0;
7429 		TAILQ_REMOVE(&bbr->r_ctl.rc_map, rsm, r_next);
7430 		if (rsm->r_in_tmap) {
7431 			TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
7432 			rsm->r_in_tmap = 0;
7433 		}
7434 		if (bbr->r_ctl.rc_next == rsm) {
7435 			/* scoot along the marker */
7436 			bbr->r_ctl.rc_next = TAILQ_FIRST(&bbr->r_ctl.rc_map);
7437 		}
7438 		bbr_isit_a_pkt_epoch(bbr, cts, rsm, __LINE__, BBR_CUM_ACKED);
7439 		/* Adjust the packet counts */
7440 		left = th_ack - rsm->r_end;
7441 		/* Free back to zone */
7442 		bbr_free(bbr, rsm);
7443 		if (left) {
7444 			rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
7445 			goto more;
7446 		}
7447 		goto proc_sack;
7448 	}
7449 	if (rsm->r_flags & BBR_ACKED) {
7450 		/*
7451 		 * It was acked on the scoreboard -- remove it from total
7452 		 * for the part being cum-acked.
7453 		 */
7454 		p_acked += (rsm->r_end - rsm->r_start);
7455 		bbr->r_ctl.rc_sacked -= (th_ack - rsm->r_start);
7456 		if (bbr->r_ctl.rc_sacked == 0)
7457 			bbr->r_ctl.rc_sacklast = NULL;
7458 	} else {
7459 		/*
7460 		 * It was acked up to th_ack point for the first time
7461 		 */
7462 		struct bbr_sendmap lrsm;
7463 
7464 		memcpy(&lrsm, rsm, sizeof(struct bbr_sendmap));
7465 		lrsm.r_end = th_ack;
7466 		bbr_update_rtt(tp, bbr, &lrsm, to, cts, BBR_CUM_ACKED, th_ack);
7467 	}
7468 	if ((rsm->r_flags & BBR_MARKED_LOST) &&
7469 	    ((rsm->r_flags & BBR_ACKED) == 0)) {
7470 		/*
7471 		 * It was marked lost and partly ack'd now
7472 		 * for the first time. We lower the rc_lost_bytes
7473 		 * and still leave it MARKED.
7474 		 */
7475 		bbr->r_ctl.rc_lost_bytes -= th_ack - rsm->r_start;
7476 	}
7477 	bbr_isit_a_pkt_epoch(bbr, cts, rsm, __LINE__, BBR_CUM_ACKED);
7478 	bbr->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
7479 	rsm->r_rtr_bytes = 0;
7480 	/* adjust packet count */
7481 	rsm->r_start = th_ack;
7482 proc_sack:
7483 	/* Check for reneging */
7484 	rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
7485 	if (rsm && (rsm->r_flags & BBR_ACKED) && (th_ack == rsm->r_start)) {
7486 		/*
7487 		 * The peer has moved snd_una up to the edge of this send,
7488 		 * i.e. one that it had previously acked. The only way that
7489 		 * can be true if the peer threw away data (space issues)
7490 		 * that it had previously sacked (else it would have given
7491 		 * us snd_una up to (rsm->r_end). We need to undo the acked
7492 		 * markings here.
7493 		 *
7494 		 * Note we have to look to make sure th_ack is our
7495 		 * rsm->r_start in case we get an old ack where th_ack is
7496 		 * behind snd_una.
7497 		 */
7498 		bbr_peer_reneges(bbr, rsm, th->th_ack);
7499 	}
7500 	if ((to->to_flags & TOF_SACK) == 0) {
7501 		/* We are done nothing left to log */
7502 		goto out;
7503 	}
7504 	rsm = TAILQ_LAST_FAST(&bbr->r_ctl.rc_map, bbr_sendmap, r_next);
7505 	if (rsm) {
7506 		last_seq = rsm->r_end;
7507 	} else {
7508 		last_seq = tp->snd_max;
7509 	}
7510 	/* Sack block processing */
7511 	if (SEQ_GT(th_ack, tp->snd_una))
7512 		ack_point = th_ack;
7513 	else
7514 		ack_point = tp->snd_una;
7515 	for (i = 0; i < to->to_nsacks; i++) {
7516 		bcopy((to->to_sacks + i * TCPOLEN_SACK),
7517 		    &sack, sizeof(sack));
7518 		sack.start = ntohl(sack.start);
7519 		sack.end = ntohl(sack.end);
7520 		if (SEQ_GT(sack.end, sack.start) &&
7521 		    SEQ_GT(sack.start, ack_point) &&
7522 		    SEQ_LT(sack.start, tp->snd_max) &&
7523 		    SEQ_GT(sack.end, ack_point) &&
7524 		    SEQ_LEQ(sack.end, tp->snd_max)) {
7525 			if ((bbr->r_ctl.rc_num_small_maps_alloced > bbr_sack_block_limit) &&
7526 			    (SEQ_LT(sack.end, last_seq)) &&
7527 			    ((sack.end - sack.start) < (p_maxseg / 8))) {
7528 				/*
7529 				 * Not the last piece and its smaller than
7530 				 * 1/8th of a p_maxseg. We ignore this.
7531 				 */
7532 				BBR_STAT_INC(bbr_runt_sacks);
7533 				continue;
7534 			}
7535 			sack_blocks[num_sack_blks] = sack;
7536 			num_sack_blks++;
7537 		} else if (SEQ_LEQ(sack.start, th_ack) &&
7538 		    SEQ_LEQ(sack.end, th_ack)) {
7539 			/*
7540 			 * Its a D-SACK block.
7541 			 */
7542 			tcp_record_dsack(tp, sack.start, sack.end, 0);
7543 		}
7544 	}
7545 	if (num_sack_blks == 0)
7546 		goto out;
7547 	/*
7548 	 * Sort the SACK blocks so we can update the rack scoreboard with
7549 	 * just one pass.
7550 	 */
7551 	new_sb = sack_filter_blks(tp, &bbr->r_ctl.bbr_sf, sack_blocks,
7552 				  num_sack_blks, th->th_ack);
7553 	ctf_log_sack_filter(bbr->rc_tp, new_sb, sack_blocks);
7554 	BBR_STAT_ADD(bbr_sack_blocks, num_sack_blks);
7555 	BBR_STAT_ADD(bbr_sack_blocks_skip, (num_sack_blks - new_sb));
7556 	num_sack_blks = new_sb;
7557 	if (num_sack_blks < 2) {
7558 		goto do_sack_work;
7559 	}
7560 	/* Sort the sacks */
7561 	for (i = 0; i < num_sack_blks; i++) {
7562 		for (j = i + 1; j < num_sack_blks; j++) {
7563 			if (SEQ_GT(sack_blocks[i].end, sack_blocks[j].end)) {
7564 				sack = sack_blocks[i];
7565 				sack_blocks[i] = sack_blocks[j];
7566 				sack_blocks[j] = sack;
7567 			}
7568 		}
7569 	}
7570 	/*
7571 	 * Now are any of the sack block ends the same (yes some
7572 	 * implememtations send these)?
7573 	 */
7574 again:
7575 	if (num_sack_blks > 1) {
7576 		for (i = 0; i < num_sack_blks; i++) {
7577 			for (j = i + 1; j < num_sack_blks; j++) {
7578 				if (sack_blocks[i].end == sack_blocks[j].end) {
7579 					/*
7580 					 * Ok these two have the same end we
7581 					 * want the smallest end and then
7582 					 * throw away the larger and start
7583 					 * again.
7584 					 */
7585 					if (SEQ_LT(sack_blocks[j].start, sack_blocks[i].start)) {
7586 						/*
7587 						 * The second block covers
7588 						 * more area use that
7589 						 */
7590 						sack_blocks[i].start = sack_blocks[j].start;
7591 					}
7592 					/*
7593 					 * Now collapse out the dup-sack and
7594 					 * lower the count
7595 					 */
7596 					for (k = (j + 1); k < num_sack_blks; k++) {
7597 						sack_blocks[j].start = sack_blocks[k].start;
7598 						sack_blocks[j].end = sack_blocks[k].end;
7599 						j++;
7600 					}
7601 					num_sack_blks--;
7602 					goto again;
7603 				}
7604 			}
7605 		}
7606 	}
7607 do_sack_work:
7608 	rsm = bbr->r_ctl.rc_sacklast;
7609 	for (i = 0; i < num_sack_blks; i++) {
7610 		acked = bbr_proc_sack_blk(tp, bbr, &sack_blocks[i], to, &rsm, cts);
7611 		if (acked) {
7612 			bbr->r_wanted_output = 1;
7613 			changed += acked;
7614 			sack_changed += acked;
7615 		}
7616 	}
7617 out:
7618 	*prev_acked = p_acked;
7619 	if ((sack_changed) && (!IN_RECOVERY(tp->t_flags))) {
7620 		/*
7621 		 * Ok we have a high probability that we need to go in to
7622 		 * recovery since we have data sack'd
7623 		 */
7624 		struct bbr_sendmap *rsm;
7625 
7626 		rsm = bbr_check_recovery_mode(tp, bbr, cts);
7627 		if (rsm) {
7628 			/* Enter recovery */
7629 			entered_recovery = 1;
7630 			bbr->r_wanted_output = 1;
7631 			/*
7632 			 * When we enter recovery we need to assure we send
7633 			 * one packet.
7634 			 */
7635 			if (bbr->r_ctl.rc_resend == NULL) {
7636 				bbr->r_ctl.rc_resend = rsm;
7637 			}
7638 		}
7639 	}
7640 	if (IN_RECOVERY(tp->t_flags) && (entered_recovery == 0)) {
7641 		/*
7642 		 * See if we need to rack-retransmit anything if so set it
7643 		 * up as the thing to resend assuming something else is not
7644 		 * already in that position.
7645 		 */
7646 		if (bbr->r_ctl.rc_resend == NULL) {
7647 			bbr->r_ctl.rc_resend = bbr_check_recovery_mode(tp, bbr, cts);
7648 		}
7649 	}
7650 	/*
7651 	 * We return the amount that changed via sack, this is used by the
7652 	 * ack-received code to augment what was changed between th_ack <->
7653 	 * snd_una.
7654 	 */
7655 	return (sack_changed);
7656 }
7657 
7658 static void
7659 bbr_strike_dupack(struct tcp_bbr *bbr)
7660 {
7661 	struct bbr_sendmap *rsm;
7662 
7663 	rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
7664 	if (rsm && (rsm->r_dupack < 0xff)) {
7665 		rsm->r_dupack++;
7666 		if (rsm->r_dupack >= DUP_ACK_THRESHOLD)
7667 			bbr->r_wanted_output = 1;
7668 	}
7669 }
7670 
7671 /*
7672  * Return value of 1, we do not need to call bbr_process_data().
7673  * return value of 0, bbr_process_data can be called.
7674  * For ret_val if its 0 the TCB is locked and valid, if its non-zero
7675  * its unlocked and probably unsafe to touch the TCB.
7676  */
7677 static int
7678 bbr_process_ack(struct mbuf *m, struct tcphdr *th, struct socket *so,
7679     struct tcpcb *tp, struct tcpopt *to,
7680     uint32_t tiwin, int32_t tlen,
7681     int32_t * ofia, int32_t thflags, int32_t * ret_val)
7682 {
7683 	int32_t ourfinisacked = 0;
7684 	int32_t acked_amount;
7685 	uint16_t nsegs;
7686 	int32_t acked;
7687 	uint32_t lost, sack_changed = 0;
7688 	struct mbuf *mfree;
7689 	struct tcp_bbr *bbr;
7690 	uint32_t prev_acked = 0;
7691 
7692 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
7693 	lost = bbr->r_ctl.rc_lost;
7694 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
7695 	if (SEQ_GEQ(tp->snd_una, tp->iss + (65535 << tp->snd_scale))) {
7696 		/* Checking SEG.ACK against ISS is definitely redundant. */
7697 		tp->t_flags2 |= TF2_NO_ISS_CHECK;
7698 	}
7699 	if (!V_tcp_insecure_ack) {
7700 		tcp_seq seq_min;
7701 		bool ghost_ack_check;
7702 
7703 		if (tp->t_flags2 & TF2_NO_ISS_CHECK) {
7704 			/* Check for too old ACKs (RFC 5961, Section 5.2). */
7705 			seq_min = tp->snd_una - tp->max_sndwnd;
7706 			ghost_ack_check = false;
7707 		} else {
7708 			if (SEQ_GT(tp->iss + 1, tp->snd_una - tp->max_sndwnd)) {
7709 				/* Checking for ghost ACKs is stricter. */
7710 				seq_min = tp->iss + 1;
7711 				ghost_ack_check = true;
7712 			} else {
7713 				/*
7714 				 * Checking for too old ACKs (RFC 5961,
7715 				 * Section 5.2) is stricter.
7716 				 */
7717 				seq_min = tp->snd_una - tp->max_sndwnd;
7718 				ghost_ack_check = false;
7719 			}
7720 		}
7721 		if (SEQ_LT(th->th_ack, seq_min)) {
7722 			if (ghost_ack_check)
7723 				TCPSTAT_INC(tcps_rcvghostack);
7724 			else
7725 				TCPSTAT_INC(tcps_rcvacktooold);
7726 			/* Send challenge ACK. */
7727 			ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val);
7728 			bbr->r_wanted_output = 1;
7729 			return (1);
7730 		}
7731 	}
7732 	if (SEQ_GT(th->th_ack, tp->snd_max)) {
7733 		ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val);
7734 		bbr->r_wanted_output = 1;
7735 		return (1);
7736 	}
7737 	if (SEQ_GEQ(th->th_ack, tp->snd_una) || to->to_nsacks) {
7738 		/* Process the ack */
7739 		if (bbr->rc_in_persist)
7740 			tp->t_rxtshift = 0;
7741 		if ((th->th_ack == tp->snd_una) && (tiwin == tp->snd_wnd))
7742 			bbr_strike_dupack(bbr);
7743 		sack_changed = bbr_log_ack(tp, to, th, &prev_acked);
7744 	}
7745 	bbr_lt_bw_sampling(bbr, bbr->r_ctl.rc_rcvtime, (bbr->r_ctl.rc_lost > lost));
7746 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
7747 		/*
7748 		 * Old ack, behind the last one rcv'd or a duplicate ack
7749 		 * with SACK info.
7750 		 */
7751 		if (th->th_ack == tp->snd_una) {
7752 			bbr_ack_received(tp, bbr, th, 0, sack_changed, prev_acked, __LINE__, 0);
7753 			if (bbr->r_state == TCPS_SYN_SENT) {
7754 				/*
7755 				 * Special case on where we sent SYN. When
7756 				 * the SYN-ACK is processed in syn_sent
7757 				 * state it bumps the snd_una. This causes
7758 				 * us to hit here even though we did ack 1
7759 				 * byte.
7760 				 *
7761 				 * Go through the nothing left case so we
7762 				 * send data.
7763 				 */
7764 				goto nothing_left;
7765 			}
7766 		}
7767 		return (0);
7768 	}
7769 	/*
7770 	 * If we reach this point, ACK is not a duplicate, i.e., it ACKs
7771 	 * something we sent.
7772 	 */
7773 	if (tp->t_flags & TF_NEEDSYN) {
7774 		/*
7775 		 * T/TCP: Connection was half-synchronized, and our SYN has
7776 		 * been ACK'd (so connection is now fully synchronized).  Go
7777 		 * to non-starred state, increment snd_una for ACK of SYN,
7778 		 * and check if we can do window scaling.
7779 		 */
7780 		tp->t_flags &= ~TF_NEEDSYN;
7781 		tp->snd_una++;
7782 		/* Do window scaling? */
7783 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
7784 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
7785 			tp->rcv_scale = tp->request_r_scale;
7786 			/* Send window already scaled. */
7787 		}
7788 	}
7789 	INP_WLOCK_ASSERT(tptoinpcb(tp));
7790 
7791 	acked = BYTES_THIS_ACK(tp, th);
7792 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, (int)nsegs);
7793 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
7794 
7795 	/*
7796 	 * If we just performed our first retransmit, and the ACK arrives
7797 	 * within our recovery window, then it was a mistake to do the
7798 	 * retransmit in the first place.  Recover our original cwnd and
7799 	 * ssthresh, and proceed to transmit where we left off.
7800 	 */
7801 	if (tp->t_flags & TF_PREVVALID) {
7802 		tp->t_flags &= ~TF_PREVVALID;
7803 		if (tp->t_rxtshift == 1 &&
7804 		    (int)(ticks - tp->t_badrxtwin) < 0)
7805 			bbr_cong_signal(tp, th, CC_RTO_ERR, NULL);
7806 	}
7807 	SOCK_SENDBUF_LOCK(so);
7808 	acked_amount = min(acked, (int)sbavail(&so->so_snd));
7809 	tp->snd_wnd -= acked_amount;
7810 	mfree = sbcut_locked(&so->so_snd, acked_amount);
7811 	/* NB: sowwakeup_locked() does an implicit unlock. */
7812 	sowwakeup_locked(so);
7813 	m_freem(mfree);
7814 	if (SEQ_GT(th->th_ack, tp->snd_una)) {
7815 		bbr_collapse_rtt(tp, bbr, TCP_REXMTVAL(tp));
7816 	}
7817 	tp->snd_una = th->th_ack;
7818 	bbr_ack_received(tp, bbr, th, acked, sack_changed, prev_acked, __LINE__, (bbr->r_ctl.rc_lost - lost));
7819 	if (IN_RECOVERY(tp->t_flags)) {
7820 		if (SEQ_LT(th->th_ack, tp->snd_recover) &&
7821 		    (SEQ_LT(th->th_ack, tp->snd_max))) {
7822 			tcp_bbr_partialack(tp);
7823 		} else {
7824 			bbr_post_recovery(tp);
7825 		}
7826 	}
7827 	if (SEQ_GT(tp->snd_una, tp->snd_recover)) {
7828 		tp->snd_recover = tp->snd_una;
7829 	}
7830 	if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
7831 		tp->snd_nxt = tp->snd_max;
7832 	}
7833 	if (tp->snd_una == tp->snd_max) {
7834 		/* Nothing left outstanding */
7835 nothing_left:
7836 		bbr_log_progress_event(bbr, tp, ticks, PROGRESS_CLEAR, __LINE__);
7837 		if (sbavail(&so->so_snd) == 0)
7838 			bbr->rc_tp->t_acktime = 0;
7839 		if ((sbused(&so->so_snd) == 0) &&
7840 		    (tp->t_flags & TF_SENTFIN)) {
7841 			ourfinisacked = 1;
7842 		}
7843 		bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
7844 		if (bbr->rc_in_persist == 0) {
7845 			bbr->r_ctl.rc_went_idle_time = bbr->r_ctl.rc_rcvtime;
7846 		}
7847 		sack_filter_clear(&bbr->r_ctl.bbr_sf, tp->snd_una);
7848 		bbr_log_ack_clear(bbr, bbr->r_ctl.rc_rcvtime);
7849 		/*
7850 		 * We invalidate the last ack here since we
7851 		 * don't want to transfer forward the time
7852 		 * for our sum's calculations.
7853 		 */
7854 		if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
7855 		    (sbavail(&so->so_snd) == 0) &&
7856 		    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
7857 			/*
7858 			 * The socket was gone and the peer sent data, time
7859 			 * to reset him.
7860 			 */
7861 			*ret_val = 1;
7862 			tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
7863 			/* tcp_close will kill the inp pre-log the Reset */
7864 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
7865 			tp = tcp_close(tp);
7866 			ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, tlen);
7867 			BBR_STAT_INC(bbr_dropped_af_data);
7868 			return (1);
7869 		}
7870 		/* Set need output so persist might get set */
7871 		bbr->r_wanted_output = 1;
7872 	}
7873 	if (ofia)
7874 		*ofia = ourfinisacked;
7875 	return (0);
7876 }
7877 
7878 static void
7879 bbr_enter_persist(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts, int32_t line)
7880 {
7881 	if (bbr->rc_in_persist == 0) {
7882 		bbr_timer_cancel(bbr, __LINE__, cts);
7883 		bbr->r_ctl.rc_last_delay_val = 0;
7884 		tp->t_rxtshift = 0;
7885 		bbr->rc_in_persist = 1;
7886 		bbr->r_ctl.rc_went_idle_time = cts;
7887 		/* We should be capped when rw went to 0 but just in case */
7888 		bbr_log_type_pesist(bbr, cts, 0, line, 1);
7889 		/* Time freezes for the state, so do the accounting now */
7890 		if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
7891 			uint32_t time_in;
7892 
7893 			time_in = cts - bbr->r_ctl.rc_bbr_state_time;
7894 			if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW) {
7895 				int32_t idx;
7896 
7897 				idx = bbr_state_val(bbr);
7898 				counter_u64_add(bbr_state_time[(idx + 5)], time_in);
7899 			} else {
7900 				counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
7901 			}
7902 		}
7903 		bbr->r_ctl.rc_bbr_state_time = cts;
7904 	}
7905 }
7906 
7907 static void
7908 bbr_restart_after_idle(struct tcp_bbr *bbr, uint32_t cts, uint32_t idle_time)
7909 {
7910 	/*
7911 	 * Note that if idle time does not exceed our
7912 	 * threshold, we do nothing continuing the state
7913 	 * transitions we were last walking through.
7914 	 */
7915 	if (idle_time >= bbr_idle_restart_threshold) {
7916 		if (bbr->rc_use_idle_restart) {
7917 			bbr->rc_bbr_state = BBR_STATE_IDLE_EXIT;
7918 			/*
7919 			 * Set our target using BBR_UNIT, so
7920 			 * we increase at a dramatic rate but
7921 			 * we stop when we get the pipe
7922 			 * full again for our current b/w estimate.
7923 			 */
7924 			bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
7925 			bbr->r_ctl.rc_bbr_cwnd_gain = BBR_UNIT;
7926 			bbr_set_state_target(bbr, __LINE__);
7927 			/* Now setup our gains to ramp up */
7928 			bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.rc_startup_pg;
7929 			bbr->r_ctl.rc_bbr_cwnd_gain = bbr->r_ctl.rc_startup_pg;
7930 			bbr_log_type_statechange(bbr, cts, __LINE__);
7931 		} else if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW) {
7932 			bbr_substate_change(bbr, cts, __LINE__, 1);
7933 		}
7934 	}
7935 }
7936 
7937 static void
7938 bbr_exit_persist(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts, int32_t line)
7939 {
7940 	uint32_t idle_time;
7941 
7942 	if (bbr->rc_in_persist == 0)
7943 		return;
7944 	idle_time = bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time);
7945 	bbr->rc_in_persist = 0;
7946 	bbr->rc_hit_state_1 = 0;
7947 	bbr->r_ctl.rc_del_time = cts;
7948 	/*
7949 	 * We invalidate the last ack here since we
7950 	 * don't want to transfer forward the time
7951 	 * for our sum's calculations.
7952 	 */
7953 	if (tcp_in_hpts(bbr->rc_tp)) {
7954 		tcp_hpts_remove(bbr->rc_tp);
7955 		bbr->rc_timer_first = 0;
7956 		bbr->r_ctl.rc_hpts_flags = 0;
7957 		bbr->r_ctl.rc_last_delay_val = 0;
7958 		bbr->r_ctl.rc_hptsi_agg_delay = 0;
7959 		bbr->r_agg_early_set = 0;
7960 		bbr->r_ctl.rc_agg_early = 0;
7961 	}
7962 	bbr_log_type_pesist(bbr, cts, idle_time, line, 0);
7963 	if (idle_time >= bbr_rtt_probe_time) {
7964 		/*
7965 		 * This qualifies as a RTT_PROBE session since we drop the
7966 		 * data outstanding to nothing and waited more than
7967 		 * bbr_rtt_probe_time.
7968 		 */
7969 		bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_PERSIST, 0);
7970 		bbr->r_ctl.last_in_probertt = bbr->r_ctl.rc_rtt_shrinks = cts;
7971 	}
7972 	tp->t_rxtshift = 0;
7973 	/*
7974 	 * If in probeBW and we have persisted more than an RTT lets do
7975 	 * special handling.
7976 	 */
7977 	/* Force a time based epoch */
7978 	bbr_set_epoch(bbr, cts, __LINE__);
7979 	/*
7980 	 * Setup the lost so we don't count anything against the guy
7981 	 * we have been stuck with during persists.
7982 	 */
7983 	bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
7984 	/* Time un-freezes for the state */
7985 	bbr->r_ctl.rc_bbr_state_time = cts;
7986 	if ((bbr->rc_bbr_state == BBR_STATE_PROBE_BW) ||
7987 	    (bbr->rc_bbr_state == BBR_STATE_PROBE_RTT)) {
7988 		/*
7989 		 * If we are going back to probe-bw
7990 		 * or probe_rtt, we may need to possibly
7991 		 * do a fast restart.
7992 		 */
7993 		bbr_restart_after_idle(bbr, cts, idle_time);
7994 	}
7995 }
7996 
7997 static void
7998 bbr_collapsed_window(struct tcp_bbr *bbr)
7999 {
8000 	/*
8001 	 * Now we must walk the
8002 	 * send map and divide the
8003 	 * ones left stranded. These
8004 	 * guys can't cause us to abort
8005 	 * the connection and are really
8006 	 * "unsent". However if a buggy
8007 	 * client actually did keep some
8008 	 * of the data i.e. collapsed the win
8009 	 * and refused to ack and then opened
8010 	 * the win and acked that data. We would
8011 	 * get into an ack war, the simplier
8012 	 * method then of just pretending we
8013 	 * did not send those segments something
8014 	 * won't work.
8015 	 */
8016 	struct bbr_sendmap *rsm, *nrsm;
8017 	tcp_seq max_seq;
8018 	uint32_t maxseg;
8019 	int can_split = 0;
8020 	int fnd = 0;
8021 
8022 	maxseg = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
8023 	max_seq = bbr->rc_tp->snd_una + bbr->rc_tp->snd_wnd;
8024 	bbr_log_type_rwnd_collapse(bbr, max_seq, 1, 0);
8025 	TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_map, r_next) {
8026 		/* Find the first seq past or at maxseq */
8027 		if (rsm->r_flags & BBR_RWND_COLLAPSED)
8028 			rsm->r_flags &= ~BBR_RWND_COLLAPSED;
8029 		if (SEQ_GEQ(max_seq, rsm->r_start) &&
8030 		    SEQ_GEQ(rsm->r_end, max_seq)) {
8031 			fnd = 1;
8032 			break;
8033 		}
8034 	}
8035 	bbr->rc_has_collapsed = 0;
8036 	if (!fnd) {
8037 		/* Nothing to do strange */
8038 		return;
8039 	}
8040 	/*
8041 	 * Now can we split?
8042 	 *
8043 	 * We don't want to split if splitting
8044 	 * would generate too many small segments
8045 	 * less we let an attacker fragment our
8046 	 * send_map and leave us out of memory.
8047 	 */
8048 	if ((max_seq != rsm->r_start) &&
8049 	    (max_seq != rsm->r_end)){
8050 		/* can we split? */
8051 		int res1, res2;
8052 
8053 		res1 = max_seq - rsm->r_start;
8054 		res2 = rsm->r_end - max_seq;
8055 		if ((res1 >= (maxseg/8)) &&
8056 		    (res2 >= (maxseg/8))) {
8057 			/* No small pieces here */
8058 			can_split = 1;
8059 		} else if (bbr->r_ctl.rc_num_small_maps_alloced < bbr_sack_block_limit) {
8060 			/* We are under the limit */
8061 			can_split = 1;
8062 		}
8063 	}
8064 	/* Ok do we need to split this rsm? */
8065 	if (max_seq == rsm->r_start) {
8066 		/* It's this guy no split required */
8067 		nrsm = rsm;
8068 	} else if (max_seq == rsm->r_end) {
8069 		/* It's the next one no split required. */
8070 		nrsm = TAILQ_NEXT(rsm, r_next);
8071 		if (nrsm == NULL) {
8072 			/* Huh? */
8073 			return;
8074 		}
8075 	} else if (can_split && SEQ_LT(max_seq, rsm->r_end)) {
8076 		/* yep we need to split it */
8077 		nrsm = bbr_alloc_limit(bbr, BBR_LIMIT_TYPE_SPLIT);
8078 		if (nrsm == NULL) {
8079 			/* failed XXXrrs what can we do mark the whole? */
8080 			nrsm = rsm;
8081 			goto no_split;
8082 		}
8083 		/* Clone it */
8084 		bbr_log_type_rwnd_collapse(bbr, max_seq, 3, 0);
8085 		bbr_clone_rsm(bbr, nrsm, rsm, max_seq);
8086 		TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
8087 		if (rsm->r_in_tmap) {
8088 			TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8089 			nrsm->r_in_tmap = 1;
8090 		}
8091 	} else {
8092 		/*
8093 		 * Split not allowed just start here just
8094 		 * use this guy.
8095 		 */
8096 		nrsm = rsm;
8097 	}
8098 no_split:
8099 	BBR_STAT_INC(bbr_collapsed_win);
8100 	/* reuse fnd as a count */
8101 	fnd = 0;
8102 	TAILQ_FOREACH_FROM(nrsm, &bbr->r_ctl.rc_map, r_next) {
8103 		nrsm->r_flags |= BBR_RWND_COLLAPSED;
8104 		fnd++;
8105 		bbr->rc_has_collapsed = 1;
8106 	}
8107 	bbr_log_type_rwnd_collapse(bbr, max_seq, 4, fnd);
8108 }
8109 
8110 static void
8111 bbr_un_collapse_window(struct tcp_bbr *bbr)
8112 {
8113 	struct bbr_sendmap *rsm;
8114 	int cleared = 0;
8115 
8116 	TAILQ_FOREACH_REVERSE(rsm, &bbr->r_ctl.rc_map, bbr_head, r_next) {
8117 		if (rsm->r_flags & BBR_RWND_COLLAPSED) {
8118 			/* Clear the flag */
8119 			rsm->r_flags &= ~BBR_RWND_COLLAPSED;
8120 			cleared++;
8121 		} else
8122 			break;
8123 	}
8124 	bbr_log_type_rwnd_collapse(bbr,
8125 				   (bbr->rc_tp->snd_una + bbr->rc_tp->snd_wnd), 0, cleared);
8126 	bbr->rc_has_collapsed = 0;
8127 }
8128 
8129 /*
8130  * Return value of 1, the TCB is unlocked and most
8131  * likely gone, return value of 0, the TCB is still
8132  * locked.
8133  */
8134 static int
8135 bbr_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so,
8136     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
8137     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
8138 {
8139 	/*
8140 	 * Update window information. Don't look at window if no ACK: TAC's
8141 	 * send garbage on first SYN.
8142 	 */
8143 	uint16_t nsegs;
8144 	int32_t tfo_syn;
8145 	struct tcp_bbr *bbr;
8146 
8147 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
8148 	INP_WLOCK_ASSERT(tptoinpcb(tp));
8149 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
8150 	if ((thflags & TH_ACK) &&
8151 	    (SEQ_LT(tp->snd_wl1, th->th_seq) ||
8152 	    (tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) ||
8153 	    (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) {
8154 		/* keep track of pure window updates */
8155 		if (tlen == 0 &&
8156 		    tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd)
8157 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
8158 		tp->snd_wnd = tiwin;
8159 		tp->snd_wl1 = th->th_seq;
8160 		tp->snd_wl2 = th->th_ack;
8161 		if (tp->snd_wnd > tp->max_sndwnd)
8162 			tp->max_sndwnd = tp->snd_wnd;
8163 		bbr->r_wanted_output = 1;
8164 	} else if (thflags & TH_ACK) {
8165 		if ((tp->snd_wl2 == th->th_ack) && (tiwin < tp->snd_wnd)) {
8166 			tp->snd_wnd = tiwin;
8167 			tp->snd_wl1 = th->th_seq;
8168 			tp->snd_wl2 = th->th_ack;
8169 		}
8170 	}
8171 	if (tp->snd_wnd < ctf_outstanding(tp))
8172 		/* The peer collapsed its window on us */
8173 		bbr_collapsed_window(bbr);
8174  	else if (bbr->rc_has_collapsed)
8175 		bbr_un_collapse_window(bbr);
8176 	/* Was persist timer active and now we have window space? */
8177 	if ((bbr->rc_in_persist != 0) &&
8178 	    (tp->snd_wnd >= min((bbr->r_ctl.rc_high_rwnd/2),
8179 				bbr_minseg(bbr)))) {
8180 		/*
8181 		 * Make the rate persist at end of persist mode if idle long
8182 		 * enough
8183 		 */
8184 		bbr_exit_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
8185 
8186 		/* Make sure we output to start the timer */
8187 		bbr->r_wanted_output = 1;
8188 	}
8189 	/* Do we need to enter persist? */
8190 	if ((bbr->rc_in_persist == 0) &&
8191 	    (tp->snd_wnd < min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) &&
8192 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
8193 	    (tp->snd_max == tp->snd_una) &&
8194 	    sbavail(&so->so_snd) &&
8195 	    (sbavail(&so->so_snd) > tp->snd_wnd)) {
8196 		/* No send window.. we must enter persist */
8197 		bbr_enter_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
8198 	}
8199 	if (tp->t_flags2 & TF2_DROP_AF_DATA) {
8200 		m_freem(m);
8201 		return (0);
8202 	}
8203 	/*
8204 	 * We don't support urgent data but
8205 	 * drag along the up just to make sure
8206 	 * if there is a stack switch no one
8207 	 * is surprised.
8208 	 */
8209 	tp->rcv_up = tp->rcv_nxt;
8210 
8211 	/*
8212 	 * Process the segment text, merging it into the TCP sequencing
8213 	 * queue, and arranging for acknowledgment of receipt if necessary.
8214 	 * This process logically involves adjusting tp->rcv_wnd as data is
8215 	 * presented to the user (this happens in tcp_usrreq.c, case
8216 	 * PRU_RCVD).  If a FIN has already been received on this connection
8217 	 * then we just ignore the text.
8218 	 */
8219 	tfo_syn = ((tp->t_state == TCPS_SYN_RECEIVED) &&
8220 	    (tp->t_flags & TF_FASTOPEN));
8221 	if ((tlen || (thflags & TH_FIN) || (tfo_syn && tlen > 0)) &&
8222 	    TCPS_HAVERCVDFIN(tp->t_state) == 0) {
8223 		tcp_seq save_start = th->th_seq;
8224 		tcp_seq save_rnxt  = tp->rcv_nxt;
8225 		int     save_tlen  = tlen;
8226 
8227 		m_adj(m, drop_hdrlen);	/* delayed header drop */
8228 		/*
8229 		 * Insert segment which includes th into TCP reassembly
8230 		 * queue with control block tp.  Set thflags to whether
8231 		 * reassembly now includes a segment with FIN.  This handles
8232 		 * the common case inline (segment is the next to be
8233 		 * received on an established connection, and the queue is
8234 		 * empty), avoiding linkage into and removal from the queue
8235 		 * and repetition of various conversions. Set DELACK for
8236 		 * segments received in order, but ack immediately when
8237 		 * segments are out of order (so fast retransmit can work).
8238 		 */
8239 		if (th->th_seq == tp->rcv_nxt &&
8240 		    SEGQ_EMPTY(tp) &&
8241 		    (TCPS_HAVEESTABLISHED(tp->t_state) ||
8242 		    tfo_syn)) {
8243 #ifdef NETFLIX_SB_LIMITS
8244 			u_int mcnt, appended;
8245 
8246 			if (so->so_rcv.sb_shlim) {
8247 				mcnt = m_memcnt(m);
8248 				appended = 0;
8249 				if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
8250 				    CFO_NOSLEEP, NULL) == false) {
8251 					counter_u64_add(tcp_sb_shlim_fails, 1);
8252 					m_freem(m);
8253 					return (0);
8254 				}
8255 			}
8256 
8257 #endif
8258 			if (DELAY_ACK(tp, bbr, nsegs) || tfo_syn) {
8259 				bbr->bbr_segs_rcvd += max(1, nsegs);
8260 				tp->t_flags |= TF_DELACK;
8261 				bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
8262 			} else {
8263 				bbr->r_wanted_output = 1;
8264 				tp->t_flags |= TF_ACKNOW;
8265 			}
8266 			tp->rcv_nxt += tlen;
8267 			if (tlen &&
8268 			    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
8269 			    (tp->t_fbyte_in == 0)) {
8270 				tp->t_fbyte_in = ticks;
8271 				if (tp->t_fbyte_in == 0)
8272 					tp->t_fbyte_in = 1;
8273 				if (tp->t_fbyte_out && tp->t_fbyte_in)
8274 					tp->t_flags2 |= TF2_FBYTES_COMPLETE;
8275 			}
8276 			thflags = tcp_get_flags(th) & TH_FIN;
8277 			KMOD_TCPSTAT_ADD(tcps_rcvpack, (int)nsegs);
8278 			KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
8279 			SOCK_RECVBUF_LOCK(so);
8280 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE)
8281 				m_freem(m);
8282 			else
8283 #ifdef NETFLIX_SB_LIMITS
8284 				appended =
8285 #endif
8286 					sbappendstream_locked(&so->so_rcv, m, 0);
8287 			/* NB: sorwakeup_locked() does an implicit unlock. */
8288 			sorwakeup_locked(so);
8289 #ifdef NETFLIX_SB_LIMITS
8290 			if (so->so_rcv.sb_shlim && appended != mcnt)
8291 				counter_fo_release(so->so_rcv.sb_shlim,
8292 				    mcnt - appended);
8293 #endif
8294 
8295 		} else {
8296 			/*
8297 			 * XXX: Due to the header drop above "th" is
8298 			 * theoretically invalid by now.  Fortunately
8299 			 * m_adj() doesn't actually frees any mbufs when
8300 			 * trimming from the head.
8301 			 */
8302 			tcp_seq temp = save_start;
8303 
8304 			thflags = tcp_reass(tp, th, &temp, &tlen, m);
8305 			tp->t_flags |= TF_ACKNOW;
8306 			if (tp->t_flags & TF_WAKESOR) {
8307 				tp->t_flags &= ~TF_WAKESOR;
8308 				/* NB: sorwakeup_locked() does an implicit unlock. */
8309 				sorwakeup_locked(so);
8310 			}
8311 		}
8312 		if ((tp->t_flags & TF_SACK_PERMIT) &&
8313 		    (save_tlen > 0) &&
8314 		    TCPS_HAVEESTABLISHED(tp->t_state)) {
8315 			if ((tlen == 0) && (SEQ_LT(save_start, save_rnxt))) {
8316 				/*
8317 				 * DSACK actually handled in the fastpath
8318 				 * above.
8319 				 */
8320 				tcp_update_sack_list(tp, save_start,
8321 				    save_start + save_tlen);
8322 			} else if ((tlen > 0) && SEQ_GT(tp->rcv_nxt, save_rnxt)) {
8323 				if ((tp->rcv_numsacks >= 1) &&
8324 				    (tp->sackblks[0].end == save_start)) {
8325 					/*
8326 					 * Partial overlap, recorded at todrop
8327 					 * above.
8328 					 */
8329 					tcp_update_sack_list(tp,
8330 					    tp->sackblks[0].start,
8331 					    tp->sackblks[0].end);
8332 				} else {
8333 					tcp_update_dsack_list(tp, save_start,
8334 					    save_start + save_tlen);
8335 				}
8336 			} else if (tlen >= save_tlen) {
8337 				/* Update of sackblks. */
8338 				tcp_update_dsack_list(tp, save_start,
8339 				    save_start + save_tlen);
8340 			} else if (tlen > 0) {
8341 				tcp_update_dsack_list(tp, save_start,
8342 				    save_start + tlen);
8343 			}
8344 		}
8345 	} else {
8346 		m_freem(m);
8347 		thflags &= ~TH_FIN;
8348 	}
8349 
8350 	/*
8351 	 * If FIN is received ACK the FIN and let the user know that the
8352 	 * connection is closing.
8353 	 */
8354 	if (thflags & TH_FIN) {
8355 		if (TCPS_HAVERCVDFIN(tp->t_state) == 0) {
8356 			/* The socket upcall is handled by socantrcvmore. */
8357 			socantrcvmore(so);
8358 			/*
8359 			 * If connection is half-synchronized (ie NEEDSYN
8360 			 * flag on) then delay ACK, so it may be piggybacked
8361 			 * when SYN is sent. Otherwise, since we received a
8362 			 * FIN then no more input can be expected, send ACK
8363 			 * now.
8364 			 */
8365 			if (tp->t_flags & TF_NEEDSYN) {
8366 				tp->t_flags |= TF_DELACK;
8367 				bbr_timer_cancel(bbr,
8368 				    __LINE__, bbr->r_ctl.rc_rcvtime);
8369 			} else {
8370 				tp->t_flags |= TF_ACKNOW;
8371 			}
8372 			tp->rcv_nxt++;
8373 		}
8374 		switch (tp->t_state) {
8375 			/*
8376 			 * In SYN_RECEIVED and ESTABLISHED STATES enter the
8377 			 * CLOSE_WAIT state.
8378 			 */
8379 		case TCPS_SYN_RECEIVED:
8380 			tp->t_starttime = ticks;
8381 			/* FALLTHROUGH */
8382 		case TCPS_ESTABLISHED:
8383 			tcp_state_change(tp, TCPS_CLOSE_WAIT);
8384 			break;
8385 
8386 			/*
8387 			 * If still in FIN_WAIT_1 STATE FIN has not been
8388 			 * acked so enter the CLOSING state.
8389 			 */
8390 		case TCPS_FIN_WAIT_1:
8391 			tcp_state_change(tp, TCPS_CLOSING);
8392 			break;
8393 
8394 			/*
8395 			 * In FIN_WAIT_2 state enter the TIME_WAIT state,
8396 			 * starting the time-wait timer, turning off the
8397 			 * other standard timers.
8398 			 */
8399 		case TCPS_FIN_WAIT_2:
8400 			bbr->rc_timer_first = 1;
8401 			bbr_timer_cancel(bbr,
8402 			    __LINE__, bbr->r_ctl.rc_rcvtime);
8403 			tcp_twstart(tp);
8404 			return (1);
8405 		}
8406 	}
8407 	/*
8408 	 * Return any desired output.
8409 	 */
8410 	if ((tp->t_flags & TF_ACKNOW) ||
8411 	    (sbavail(&so->so_snd) > ctf_outstanding(tp))) {
8412 		bbr->r_wanted_output = 1;
8413 	}
8414 	return (0);
8415 }
8416 
8417 /*
8418  * Here nothing is really faster, its just that we
8419  * have broken out the fast-data path also just like
8420  * the fast-ack. Return 1 if we processed the packet
8421  * return 0 if you need to take the "slow-path".
8422  */
8423 static int
8424 bbr_do_fastnewdata(struct mbuf *m, struct tcphdr *th, struct socket *so,
8425     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
8426     uint32_t tiwin, int32_t nxt_pkt)
8427 {
8428 	uint16_t nsegs;
8429 	int32_t newsize = 0;	/* automatic sockbuf scaling */
8430 	struct tcp_bbr *bbr;
8431 #ifdef NETFLIX_SB_LIMITS
8432 	u_int mcnt, appended;
8433 #endif
8434 
8435 	/* On the hpts and we would have called output */
8436 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
8437 
8438 	/*
8439 	 * If last ACK falls within this segment's sequence numbers, record
8440 	 * the timestamp. NOTE that the test is modified according to the
8441 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
8442 	 */
8443 	if (bbr->r_ctl.rc_resend != NULL) {
8444 		return (0);
8445 	}
8446 	if (tiwin && tiwin != tp->snd_wnd) {
8447 		return (0);
8448 	}
8449 	if (__predict_false((tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN)))) {
8450 		return (0);
8451 	}
8452 	if (__predict_false((to->to_flags & TOF_TS) &&
8453 	    (TSTMP_LT(to->to_tsval, tp->ts_recent)))) {
8454 		return (0);
8455 	}
8456 	if (__predict_false((th->th_ack != tp->snd_una))) {
8457 		return (0);
8458 	}
8459 	if (__predict_false(tlen > sbspace(&so->so_rcv))) {
8460 		return (0);
8461 	}
8462 	if ((to->to_flags & TOF_TS) != 0 &&
8463 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
8464 		tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
8465 		tp->ts_recent = to->to_tsval;
8466 	}
8467 	/*
8468 	 * This is a pure, in-sequence data packet with nothing on the
8469 	 * reassembly queue and we have enough buffer space to take it.
8470 	 */
8471 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
8472 
8473 #ifdef NETFLIX_SB_LIMITS
8474 	if (so->so_rcv.sb_shlim) {
8475 		mcnt = m_memcnt(m);
8476 		appended = 0;
8477 		if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
8478 		    CFO_NOSLEEP, NULL) == false) {
8479 			counter_u64_add(tcp_sb_shlim_fails, 1);
8480 			m_freem(m);
8481 			return (1);
8482 		}
8483 	}
8484 #endif
8485 	/* Clean receiver SACK report if present */
8486 	if (tp->rcv_numsacks)
8487 		tcp_clean_sackreport(tp);
8488 	KMOD_TCPSTAT_INC(tcps_preddat);
8489 	tp->rcv_nxt += tlen;
8490 	if (tlen &&
8491 	    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
8492 	    (tp->t_fbyte_in == 0)) {
8493 		tp->t_fbyte_in = ticks;
8494 		if (tp->t_fbyte_in == 0)
8495 			tp->t_fbyte_in = 1;
8496 		if (tp->t_fbyte_out && tp->t_fbyte_in)
8497 			tp->t_flags2 |= TF2_FBYTES_COMPLETE;
8498 	}
8499 	/*
8500 	 * Pull snd_wl1 up to prevent seq wrap relative to th_seq.
8501 	 */
8502 	tp->snd_wl1 = th->th_seq;
8503 	/*
8504 	 * Pull rcv_up up to prevent seq wrap relative to rcv_nxt.
8505 	 */
8506 	tp->rcv_up = tp->rcv_nxt;
8507 	KMOD_TCPSTAT_ADD(tcps_rcvpack, (int)nsegs);
8508 	KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
8509 	newsize = tcp_autorcvbuf(m, th, so, tp, tlen);
8510 
8511 	/* Add data to socket buffer. */
8512 	SOCK_RECVBUF_LOCK(so);
8513 	if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
8514 		m_freem(m);
8515 	} else {
8516 		/*
8517 		 * Set new socket buffer size. Give up when limit is
8518 		 * reached.
8519 		 */
8520 		if (newsize)
8521 			if (!sbreserve_locked(so, SO_RCV, newsize, NULL))
8522 				so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
8523 		m_adj(m, drop_hdrlen);	/* delayed header drop */
8524 
8525 #ifdef NETFLIX_SB_LIMITS
8526 		appended =
8527 #endif
8528 			sbappendstream_locked(&so->so_rcv, m, 0);
8529 		ctf_calc_rwin(so, tp);
8530 	}
8531 	/* NB: sorwakeup_locked() does an implicit unlock. */
8532 	sorwakeup_locked(so);
8533 #ifdef NETFLIX_SB_LIMITS
8534 	if (so->so_rcv.sb_shlim && mcnt != appended)
8535 		counter_fo_release(so->so_rcv.sb_shlim, mcnt - appended);
8536 #endif
8537 	if (DELAY_ACK(tp, bbr, nsegs)) {
8538 		bbr->bbr_segs_rcvd += max(1, nsegs);
8539 		tp->t_flags |= TF_DELACK;
8540 		bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
8541 	} else {
8542 		bbr->r_wanted_output = 1;
8543 		tp->t_flags |= TF_ACKNOW;
8544 	}
8545 	return (1);
8546 }
8547 
8548 /*
8549  * This subfunction is used to try to highly optimize the
8550  * fast path. We again allow window updates that are
8551  * in sequence to remain in the fast-path. We also add
8552  * in the __predict's to attempt to help the compiler.
8553  * Note that if we return a 0, then we can *not* process
8554  * it and the caller should push the packet into the
8555  * slow-path. If we return 1, then all is well and
8556  * the packet is fully processed.
8557  */
8558 static int
8559 bbr_fastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
8560     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
8561     uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos)
8562 {
8563 	int32_t acked;
8564 	uint16_t nsegs;
8565 	uint32_t sack_changed;
8566 	uint32_t prev_acked = 0;
8567 	struct tcp_bbr *bbr;
8568 
8569 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
8570 		/* Old ack, behind (or duplicate to) the last one rcv'd */
8571 		return (0);
8572 	}
8573 	if (__predict_false(SEQ_GT(th->th_ack, tp->snd_max))) {
8574 		/* Above what we have sent? */
8575 		return (0);
8576 	}
8577 	if (__predict_false(tiwin == 0)) {
8578 		/* zero window */
8579 		return (0);
8580 	}
8581 	if (__predict_false(tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN))) {
8582 		/* We need a SYN or a FIN, unlikely.. */
8583 		return (0);
8584 	}
8585 	if ((to->to_flags & TOF_TS) && __predict_false(TSTMP_LT(to->to_tsval, tp->ts_recent))) {
8586 		/* Timestamp is behind .. old ack with seq wrap? */
8587 		return (0);
8588 	}
8589 	if (__predict_false(IN_RECOVERY(tp->t_flags))) {
8590 		/* Still recovering */
8591 		return (0);
8592 	}
8593 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
8594 	if (__predict_false(bbr->r_ctl.rc_resend != NULL)) {
8595 		/* We are retransmitting */
8596 		return (0);
8597 	}
8598 	if (__predict_false(bbr->rc_in_persist != 0)) {
8599 		/* In persist mode */
8600 		return (0);
8601 	}
8602 	if (bbr->r_ctl.rc_sacked) {
8603 		/* We have sack holes on our scoreboard */
8604 		return (0);
8605 	}
8606 	/* Ok if we reach here, we can process a fast-ack */
8607 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
8608 	sack_changed = bbr_log_ack(tp, to, th, &prev_acked);
8609 	/*
8610 	 * We never detect loss in fast ack [we can't
8611 	 * have a sack and can't be in recovery so
8612 	 * we always pass 0 (nothing detected)].
8613 	 */
8614 	bbr_lt_bw_sampling(bbr, bbr->r_ctl.rc_rcvtime, 0);
8615 	/* Did the window get updated? */
8616 	if (tiwin != tp->snd_wnd) {
8617 		tp->snd_wnd = tiwin;
8618 		tp->snd_wl1 = th->th_seq;
8619 		if (tp->snd_wnd > tp->max_sndwnd)
8620 			tp->max_sndwnd = tp->snd_wnd;
8621 	}
8622 	/* Do we need to exit persists? */
8623 	if ((bbr->rc_in_persist != 0) &&
8624 	    (tp->snd_wnd >= min((bbr->r_ctl.rc_high_rwnd/2),
8625 			       bbr_minseg(bbr)))) {
8626 		bbr_exit_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
8627 		bbr->r_wanted_output = 1;
8628 	}
8629 	/* Do we need to enter persists? */
8630 	if ((bbr->rc_in_persist == 0) &&
8631 	    (tp->snd_wnd < min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) &&
8632 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
8633 	    (tp->snd_max == tp->snd_una) &&
8634 	    sbavail(&so->so_snd) &&
8635 	    (sbavail(&so->so_snd) > tp->snd_wnd)) {
8636 		/* No send window.. we must enter persist */
8637 		bbr_enter_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
8638 	}
8639 	/*
8640 	 * If last ACK falls within this segment's sequence numbers, record
8641 	 * the timestamp. NOTE that the test is modified according to the
8642 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
8643 	 */
8644 	if ((to->to_flags & TOF_TS) != 0 &&
8645 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
8646 		tp->ts_recent_age = bbr->r_ctl.rc_rcvtime;
8647 		tp->ts_recent = to->to_tsval;
8648 	}
8649 	/*
8650 	 * This is a pure ack for outstanding data.
8651 	 */
8652 	KMOD_TCPSTAT_INC(tcps_predack);
8653 
8654 	/*
8655 	 * "bad retransmit" recovery.
8656 	 */
8657 	if (tp->t_flags & TF_PREVVALID) {
8658 		tp->t_flags &= ~TF_PREVVALID;
8659 		if (tp->t_rxtshift == 1 &&
8660 		    (int)(ticks - tp->t_badrxtwin) < 0)
8661 			bbr_cong_signal(tp, th, CC_RTO_ERR, NULL);
8662 	}
8663 	/*
8664 	 * Recalculate the transmit timer / rtt.
8665 	 *
8666 	 * Some boxes send broken timestamp replies during the SYN+ACK
8667 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
8668 	 * and blow up the retransmit timer.
8669 	 */
8670 	acked = BYTES_THIS_ACK(tp, th);
8671 
8672 #ifdef TCP_HHOOK
8673 	/* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */
8674 	hhook_run_tcp_est_in(tp, th, to);
8675 #endif
8676 
8677 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, (int)nsegs);
8678 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
8679 	sbdrop(&so->so_snd, acked);
8680 
8681 	if (SEQ_GT(th->th_ack, tp->snd_una))
8682 		bbr_collapse_rtt(tp, bbr, TCP_REXMTVAL(tp));
8683 	tp->snd_una = th->th_ack;
8684 	if (tp->snd_wnd < ctf_outstanding(tp))
8685 		/* The peer collapsed its window on us */
8686 		bbr_collapsed_window(bbr);
8687 	else if (bbr->rc_has_collapsed)
8688 		bbr_un_collapse_window(bbr);
8689 
8690 	if (SEQ_GT(tp->snd_una, tp->snd_recover)) {
8691 		tp->snd_recover = tp->snd_una;
8692 	}
8693 	bbr_ack_received(tp, bbr, th, acked, sack_changed, prev_acked, __LINE__, 0);
8694 	/*
8695 	 * Pull snd_wl2 up to prevent seq wrap relative to th_ack.
8696 	 */
8697 	tp->snd_wl2 = th->th_ack;
8698 	m_freem(m);
8699 	/*
8700 	 * If all outstanding data are acked, stop retransmit timer,
8701 	 * otherwise restart timer using current (possibly backed-off)
8702 	 * value. If process is waiting for space, wakeup/selwakeup/signal.
8703 	 * If data are ready to send, let tcp_output decide between more
8704 	 * output or persist.
8705 	 * Wake up the socket if we have room to write more.
8706 	 */
8707 	sowwakeup(so);
8708 	if (tp->snd_una == tp->snd_max) {
8709 		/* Nothing left outstanding */
8710 		bbr_log_progress_event(bbr, tp, ticks, PROGRESS_CLEAR, __LINE__);
8711 		if (sbavail(&so->so_snd) == 0)
8712 			bbr->rc_tp->t_acktime = 0;
8713 		bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
8714 		if (bbr->rc_in_persist == 0) {
8715 			bbr->r_ctl.rc_went_idle_time = bbr->r_ctl.rc_rcvtime;
8716 		}
8717 		sack_filter_clear(&bbr->r_ctl.bbr_sf, tp->snd_una);
8718 		bbr_log_ack_clear(bbr, bbr->r_ctl.rc_rcvtime);
8719 		/*
8720 		 * We invalidate the last ack here since we
8721 		 * don't want to transfer forward the time
8722 		 * for our sum's calculations.
8723 		 */
8724 		bbr->r_wanted_output = 1;
8725 	}
8726 	if (sbavail(&so->so_snd)) {
8727 		bbr->r_wanted_output = 1;
8728 	}
8729 	return (1);
8730 }
8731 
8732 /*
8733  * Return value of 1, the TCB is unlocked and most
8734  * likely gone, return value of 0, the TCB is still
8735  * locked.
8736  */
8737 static int
8738 bbr_do_syn_sent(struct mbuf *m, struct tcphdr *th, struct socket *so,
8739     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
8740     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
8741 {
8742 	int32_t todrop;
8743 	int32_t ourfinisacked = 0;
8744 	struct tcp_bbr *bbr;
8745 	int32_t ret_val = 0;
8746 
8747 	INP_WLOCK_ASSERT(tptoinpcb(tp));
8748 
8749 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
8750 	ctf_calc_rwin(so, tp);
8751 	/*
8752 	 * If the state is SYN_SENT: if seg contains an ACK, but not for our
8753 	 * SYN, drop the input. if seg contains a RST, then drop the
8754 	 * connection. if seg does not contain SYN, then drop it. Otherwise
8755 	 * this is an acceptable SYN segment initialize tp->rcv_nxt and
8756 	 * tp->irs if seg contains ack then advance tp->snd_una. BRR does
8757 	 * not support ECN so we will not say we are capable. if SYN has
8758 	 * been acked change to ESTABLISHED else SYN_RCVD state arrange for
8759 	 * segment to be acked (eventually) continue processing rest of
8760 	 * data/controls, beginning with URG
8761 	 */
8762 	if ((thflags & TH_ACK) &&
8763 	    (SEQ_LEQ(th->th_ack, tp->iss) ||
8764 	    SEQ_GT(th->th_ack, tp->snd_max))) {
8765 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
8766 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
8767 		return (1);
8768 	}
8769 	if ((thflags & (TH_ACK | TH_RST)) == (TH_ACK | TH_RST)) {
8770 		TCP_PROBE5(connect__refused, NULL, tp,
8771 		    mtod(m, const char *), tp, th);
8772 		tp = tcp_drop(tp, ECONNREFUSED);
8773 		ctf_do_drop(m, tp);
8774 		return (1);
8775 	}
8776 	if (thflags & TH_RST) {
8777 		ctf_do_drop(m, tp);
8778 		return (1);
8779 	}
8780 	if (!(thflags & TH_SYN)) {
8781 		ctf_do_drop(m, tp);
8782 		return (1);
8783 	}
8784 	tp->irs = th->th_seq;
8785 	tcp_rcvseqinit(tp);
8786 	if (thflags & TH_ACK) {
8787 		int tfo_partial = 0;
8788 
8789 		KMOD_TCPSTAT_INC(tcps_connects);
8790 		soisconnected(so);
8791 #ifdef MAC
8792 		mac_socketpeer_set_from_mbuf(m, so);
8793 #endif
8794 		/* Do window scaling on this connection? */
8795 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
8796 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
8797 			tp->rcv_scale = tp->request_r_scale;
8798 		}
8799 		tp->rcv_adv += min(tp->rcv_wnd,
8800 		    TCP_MAXWIN << tp->rcv_scale);
8801 		/*
8802 		 * If not all the data that was sent in the TFO SYN
8803 		 * has been acked, resend the remainder right away.
8804 		 */
8805 		if ((tp->t_flags & TF_FASTOPEN) &&
8806 		    (tp->snd_una != tp->snd_max)) {
8807 			tp->snd_nxt = th->th_ack;
8808 			tfo_partial = 1;
8809 		}
8810 		/*
8811 		 * If there's data, delay ACK; if there's also a FIN ACKNOW
8812 		 * will be turned on later.
8813 		 */
8814 		if (DELAY_ACK(tp, bbr, 1) && tlen != 0 && !tfo_partial) {
8815 			bbr->bbr_segs_rcvd += 1;
8816 			tp->t_flags |= TF_DELACK;
8817 			bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
8818 		} else {
8819 			bbr->r_wanted_output = 1;
8820 			tp->t_flags |= TF_ACKNOW;
8821 		}
8822 		if (SEQ_GT(th->th_ack, tp->iss)) {
8823 			/*
8824 			 * The SYN is acked
8825 			 * handle it specially.
8826 			 */
8827 			bbr_log_syn(tp, to);
8828 		}
8829 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
8830 			/*
8831 			 * We advance snd_una for the
8832 			 * fast open case. If th_ack is
8833 			 * acknowledging data beyond
8834 			 * snd_una we can't just call
8835 			 * ack-processing since the
8836 			 * data stream in our send-map
8837 			 * will start at snd_una + 1 (one
8838 			 * beyond the SYN). If its just
8839 			 * equal we don't need to do that
8840 			 * and there is no send_map.
8841 			 */
8842 			tp->snd_una++;
8843 		}
8844 		/*
8845 		 * Received <SYN,ACK> in SYN_SENT[*] state. Transitions:
8846 		 * SYN_SENT  --> ESTABLISHED SYN_SENT* --> FIN_WAIT_1
8847 		 */
8848 		tp->t_starttime = ticks;
8849 		if (tp->t_flags & TF_NEEDFIN) {
8850 			tcp_state_change(tp, TCPS_FIN_WAIT_1);
8851 			tp->t_flags &= ~TF_NEEDFIN;
8852 			thflags &= ~TH_SYN;
8853 		} else {
8854 			tcp_state_change(tp, TCPS_ESTABLISHED);
8855 			TCP_PROBE5(connect__established, NULL, tp,
8856 			    mtod(m, const char *), tp, th);
8857 			cc_conn_init(tp);
8858 		}
8859 	} else {
8860 		/*
8861 		 * Received initial SYN in SYN-SENT[*] state => simultaneous
8862 		 * open.  If segment contains CC option and there is a
8863 		 * cached CC, apply TAO test. If it succeeds, connection is *
8864 		 * half-synchronized. Otherwise, do 3-way handshake:
8865 		 * SYN-SENT -> SYN-RECEIVED SYN-SENT* -> SYN-RECEIVED* If
8866 		 * there was no CC option, clear cached CC value.
8867 		 */
8868 		tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN | TF_SONOTCONN);
8869 		tcp_state_change(tp, TCPS_SYN_RECEIVED);
8870 	}
8871 	/*
8872 	 * Advance th->th_seq to correspond to first data byte. If data,
8873 	 * trim to stay within window, dropping FIN if necessary.
8874 	 */
8875 	th->th_seq++;
8876 	if (tlen > tp->rcv_wnd) {
8877 		todrop = tlen - tp->rcv_wnd;
8878 		m_adj(m, -todrop);
8879 		tlen = tp->rcv_wnd;
8880 		thflags &= ~TH_FIN;
8881 		KMOD_TCPSTAT_INC(tcps_rcvpackafterwin);
8882 		KMOD_TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop);
8883 	}
8884 	tp->snd_wl1 = th->th_seq - 1;
8885 	tp->rcv_up = th->th_seq;
8886 	/*
8887 	 * Client side of transaction: already sent SYN and data. If the
8888 	 * remote host used T/TCP to validate the SYN, our data will be
8889 	 * ACK'd; if so, enter normal data segment processing in the middle
8890 	 * of step 5, ack processing. Otherwise, goto step 6.
8891 	 */
8892 	if (thflags & TH_ACK) {
8893 		if ((to->to_flags & TOF_TS) != 0) {
8894 			uint32_t t, rtt;
8895 
8896 			t = tcp_tv_to_mssectick(&bbr->rc_tv);
8897 			if (TSTMP_GEQ(t, to->to_tsecr)) {
8898 				rtt = t - to->to_tsecr;
8899 				if (rtt == 0) {
8900 					rtt = 1;
8901 				}
8902 				rtt *= MS_IN_USEC;
8903 				tcp_bbr_xmit_timer(bbr, rtt, 0, 0, 0);
8904 				apply_filter_min_small(&bbr->r_ctl.rc_rttprop,
8905 						       rtt, bbr->r_ctl.rc_rcvtime);
8906 			}
8907 		}
8908 		if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val))
8909 			return (ret_val);
8910 		/* We may have changed to FIN_WAIT_1 above */
8911 		if (tp->t_state == TCPS_FIN_WAIT_1) {
8912 			/*
8913 			 * In FIN_WAIT_1 STATE in addition to the processing
8914 			 * for the ESTABLISHED state if our FIN is now
8915 			 * acknowledged then enter FIN_WAIT_2.
8916 			 */
8917 			if (ourfinisacked) {
8918 				/*
8919 				 * If we can't receive any more data, then
8920 				 * closing user can proceed. Starting the
8921 				 * timer is contrary to the specification,
8922 				 * but if we don't get a FIN we'll hang
8923 				 * forever.
8924 				 *
8925 				 * XXXjl: we should release the tp also, and
8926 				 * use a compressed state.
8927 				 */
8928 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
8929 					soisdisconnected(so);
8930 					tcp_timer_activate(tp, TT_2MSL,
8931 					    (tcp_fast_finwait2_recycle ?
8932 					    tcp_finwait2_timeout :
8933 					    TP_MAXIDLE(tp)));
8934 				}
8935 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
8936 			}
8937 		}
8938 	}
8939 	return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
8940 	    tiwin, thflags, nxt_pkt));
8941 }
8942 
8943 /*
8944  * Return value of 1, the TCB is unlocked and most
8945  * likely gone, return value of 0, the TCB is still
8946  * locked.
8947  */
8948 static int
8949 bbr_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
8950 		struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
8951 		uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
8952 {
8953 	int32_t ourfinisacked = 0;
8954 	int32_t ret_val;
8955 	struct tcp_bbr *bbr;
8956 
8957 	INP_WLOCK_ASSERT(tptoinpcb(tp));
8958 
8959 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
8960 	ctf_calc_rwin(so, tp);
8961 	if ((thflags & TH_RST) ||
8962 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
8963 		return (ctf_process_rst(m, th, so, tp));
8964 	if ((thflags & TH_ACK) &&
8965 	    (SEQ_LEQ(th->th_ack, tp->snd_una) ||
8966 	     SEQ_GT(th->th_ack, tp->snd_max))) {
8967 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
8968 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
8969 		return (1);
8970 	}
8971 	if (tp->t_flags & TF_FASTOPEN) {
8972 		/*
8973 		 * When a TFO connection is in SYN_RECEIVED, the only valid
8974 		 * packets are the initial SYN, a retransmit/copy of the
8975 		 * initial SYN (possibly with a subset of the original
8976 		 * data), a valid ACK, a FIN, or a RST.
8977 		 */
8978 		if ((thflags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
8979 			tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
8980 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
8981 			return (1);
8982 		} else if (thflags & TH_SYN) {
8983 			/* non-initial SYN is ignored */
8984 			if ((bbr->r_ctl.rc_hpts_flags & PACE_TMR_RXT) ||
8985 			    (bbr->r_ctl.rc_hpts_flags & PACE_TMR_TLP) ||
8986 			    (bbr->r_ctl.rc_hpts_flags & PACE_TMR_RACK)) {
8987 				ctf_do_drop(m, NULL);
8988 				return (0);
8989 			}
8990 		} else if (!(thflags & (TH_ACK | TH_FIN | TH_RST))) {
8991 			ctf_do_drop(m, NULL);
8992 			return (0);
8993 		}
8994 	}
8995 	/*
8996 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
8997 	 * it's less than ts_recent, drop it.
8998 	 */
8999 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9000 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9001 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9002 			return (ret_val);
9003 	}
9004 	/*
9005 	 * In the SYN-RECEIVED state, validate that the packet belongs to
9006 	 * this connection before trimming the data to fit the receive
9007 	 * window.  Check the sequence number versus IRS since we know the
9008 	 * sequence numbers haven't wrapped.  This is a partial fix for the
9009 	 * "LAND" DoS attack.
9010 	 */
9011 	if (SEQ_LT(th->th_seq, tp->irs)) {
9012 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
9013 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
9014 		return (1);
9015 	}
9016 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9017 		return (ret_val);
9018 	}
9019 	/*
9020 	 * If last ACK falls within this segment's sequence numbers, record
9021 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
9022 	 * from the latest proposal of the tcplw@cray.com list (Braden
9023 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
9024 	 * with our earlier PAWS tests, so this check should be solely
9025 	 * predicated on the sequence space of this segment. 3) That we
9026 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9027 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9028 	 * SEG.Len, This modified check allows us to overcome RFC1323's
9029 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9030 	 * p.869. In such cases, we can still calculate the RTT correctly
9031 	 * when RCV.NXT == Last.ACK.Sent.
9032 	 */
9033 	if ((to->to_flags & TOF_TS) != 0 &&
9034 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9035 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9036 		    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9037 		tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
9038 		tp->ts_recent = to->to_tsval;
9039 	}
9040 	tp->snd_wnd = tiwin;
9041 	/*
9042 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
9043 	 * is on (half-synchronized state), then queue data for later
9044 	 * processing; else drop segment and return.
9045 	 */
9046 	if ((thflags & TH_ACK) == 0) {
9047 		if (tp->t_flags & TF_FASTOPEN) {
9048 			cc_conn_init(tp);
9049 		}
9050 		return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9051 					 tiwin, thflags, nxt_pkt));
9052 	}
9053 	KMOD_TCPSTAT_INC(tcps_connects);
9054 	if (tp->t_flags & TF_SONOTCONN) {
9055 		tp->t_flags &= ~TF_SONOTCONN;
9056 		soisconnected(so);
9057 	}
9058 	/* Do window scaling? */
9059 	if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
9060 	    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
9061 		tp->rcv_scale = tp->request_r_scale;
9062 	}
9063 	/*
9064 	 * ok for the first time in lets see if we can use the ts to figure
9065 	 * out what the initial RTT was.
9066 	 */
9067 	if ((to->to_flags & TOF_TS) != 0) {
9068 		uint32_t t, rtt;
9069 
9070 		t = tcp_tv_to_mssectick(&bbr->rc_tv);
9071 		if (TSTMP_GEQ(t, to->to_tsecr)) {
9072 			rtt = t - to->to_tsecr;
9073 			if (rtt == 0) {
9074 				rtt = 1;
9075 			}
9076 			rtt *= MS_IN_USEC;
9077 			tcp_bbr_xmit_timer(bbr, rtt, 0, 0, 0);
9078 			apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, bbr->r_ctl.rc_rcvtime);
9079 		}
9080 	}
9081 	/* Drop off any SYN in the send map (probably not there)  */
9082 	if (thflags & TH_ACK)
9083 		bbr_log_syn(tp, to);
9084 	if ((tp->t_flags & TF_FASTOPEN) && tp->t_tfo_pending) {
9085 		tcp_fastopen_decrement_counter(tp->t_tfo_pending);
9086 		tp->t_tfo_pending = NULL;
9087 	}
9088 	/*
9089 	 * Make transitions: SYN-RECEIVED  -> ESTABLISHED SYN-RECEIVED* ->
9090 	 * FIN-WAIT-1
9091 	 */
9092 	tp->t_starttime = ticks;
9093 	if (tp->t_flags & TF_NEEDFIN) {
9094 		tcp_state_change(tp, TCPS_FIN_WAIT_1);
9095 		tp->t_flags &= ~TF_NEEDFIN;
9096 	} else {
9097 		tcp_state_change(tp, TCPS_ESTABLISHED);
9098 		TCP_PROBE5(accept__established, NULL, tp,
9099 			   mtod(m, const char *), tp, th);
9100 		/*
9101 		 * TFO connections call cc_conn_init() during SYN
9102 		 * processing.  Calling it again here for such connections
9103 		 * is not harmless as it would undo the snd_cwnd reduction
9104 		 * that occurs when a TFO SYN|ACK is retransmitted.
9105 		 */
9106 		if (!(tp->t_flags & TF_FASTOPEN))
9107 			cc_conn_init(tp);
9108 	}
9109 	/*
9110 	 * Account for the ACK of our SYN prior to
9111 	 * regular ACK processing below, except for
9112 	 * simultaneous SYN, which is handled later.
9113 	 */
9114 	if (SEQ_GT(th->th_ack, tp->snd_una) && !(tp->t_flags & TF_NEEDSYN))
9115 		tp->snd_una++;
9116 	/*
9117 	 * If segment contains data or ACK, will call tcp_reass() later; if
9118 	 * not, do so now to pass queued data to user.
9119 	 */
9120 	if (tlen == 0 && (thflags & TH_FIN) == 0) {
9121 		(void)tcp_reass(tp, (struct tcphdr *)0, NULL, 0,
9122 			(struct mbuf *)0);
9123 		if (tp->t_flags & TF_WAKESOR) {
9124 			tp->t_flags &= ~TF_WAKESOR;
9125 			/* NB: sorwakeup_locked() does an implicit unlock. */
9126 			sorwakeup_locked(so);
9127 		}
9128 	}
9129 	tp->snd_wl1 = th->th_seq - 1;
9130 	if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
9131 		return (ret_val);
9132 	}
9133 	if (tp->t_state == TCPS_FIN_WAIT_1) {
9134 		/* We could have went to FIN_WAIT_1 (or EST) above */
9135 		/*
9136 		 * In FIN_WAIT_1 STATE in addition to the processing for the
9137 		 * ESTABLISHED state if our FIN is now acknowledged then
9138 		 * enter FIN_WAIT_2.
9139 		 */
9140 		if (ourfinisacked) {
9141 			/*
9142 			 * If we can't receive any more data, then closing
9143 			 * user can proceed. Starting the timer is contrary
9144 			 * to the specification, but if we don't get a FIN
9145 			 * we'll hang forever.
9146 			 *
9147 			 * XXXjl: we should release the tp also, and use a
9148 			 * compressed state.
9149 			 */
9150 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
9151 				soisdisconnected(so);
9152 				tcp_timer_activate(tp, TT_2MSL,
9153 						   (tcp_fast_finwait2_recycle ?
9154 						    tcp_finwait2_timeout :
9155 						    TP_MAXIDLE(tp)));
9156 			}
9157 			tcp_state_change(tp, TCPS_FIN_WAIT_2);
9158 		}
9159 	}
9160 	return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9161 				 tiwin, thflags, nxt_pkt));
9162 }
9163 
9164 /*
9165  * Return value of 1, the TCB is unlocked and most
9166  * likely gone, return value of 0, the TCB is still
9167  * locked.
9168  */
9169 static int
9170 bbr_do_established(struct mbuf *m, struct tcphdr *th, struct socket *so,
9171     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9172     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9173 {
9174 	struct tcp_bbr *bbr;
9175 	int32_t ret_val;
9176 
9177 	INP_WLOCK_ASSERT(tptoinpcb(tp));
9178 
9179 	/*
9180 	 * Header prediction: check for the two common cases of a
9181 	 * uni-directional data xfer.  If the packet has no control flags,
9182 	 * is in-sequence, the window didn't change and we're not
9183 	 * retransmitting, it's a candidate.  If the length is zero and the
9184 	 * ack moved forward, we're the sender side of the xfer.  Just free
9185 	 * the data acked & wake any higher level process that was blocked
9186 	 * waiting for space.  If the length is non-zero and the ack didn't
9187 	 * move, we're the receiver side.  If we're getting packets in-order
9188 	 * (the reassembly queue is empty), add the data toc The socket
9189 	 * buffer and note that we need a delayed ack. Make sure that the
9190 	 * hidden state-flags are also off. Since we check for
9191 	 * TCPS_ESTABLISHED first, it can only be TH_NEEDSYN.
9192 	 */
9193 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9194 	if (bbr->r_ctl.rc_delivered < (4 * tp->t_maxseg)) {
9195 		/*
9196 		 * If we have delived under 4 segments increase the initial
9197 		 * window if raised by the peer. We use this to determine
9198 		 * dynamic and static rwnd's at the end of a connection.
9199 		 */
9200 		bbr->r_ctl.rc_init_rwnd = max(tiwin, tp->snd_wnd);
9201 	}
9202 	if (__predict_true(((to->to_flags & TOF_SACK) == 0)) &&
9203 	    __predict_true((thflags & (TH_SYN | TH_FIN | TH_RST | TH_URG | TH_ACK)) == TH_ACK) &&
9204 	    __predict_true(SEGQ_EMPTY(tp)) &&
9205 	    __predict_true(th->th_seq == tp->rcv_nxt)) {
9206 		if (tlen == 0) {
9207 			if (bbr_fastack(m, th, so, tp, to, drop_hdrlen, tlen,
9208 			    tiwin, nxt_pkt, iptos)) {
9209 				return (0);
9210 			}
9211 		} else {
9212 			if (bbr_do_fastnewdata(m, th, so, tp, to, drop_hdrlen, tlen,
9213 			    tiwin, nxt_pkt)) {
9214 				return (0);
9215 			}
9216 		}
9217 	}
9218 	ctf_calc_rwin(so, tp);
9219 
9220 	if ((thflags & TH_RST) ||
9221 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
9222 		return (ctf_process_rst(m, th, so, tp));
9223 	/*
9224 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
9225 	 * synchronized state.
9226 	 */
9227 	if (thflags & TH_SYN) {
9228 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
9229 		return (ret_val);
9230 	}
9231 	/*
9232 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9233 	 * it's less than ts_recent, drop it.
9234 	 */
9235 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9236 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9237 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9238 			return (ret_val);
9239 	}
9240 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9241 		return (ret_val);
9242 	}
9243 	/*
9244 	 * If last ACK falls within this segment's sequence numbers, record
9245 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
9246 	 * from the latest proposal of the tcplw@cray.com list (Braden
9247 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
9248 	 * with our earlier PAWS tests, so this check should be solely
9249 	 * predicated on the sequence space of this segment. 3) That we
9250 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9251 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9252 	 * SEG.Len, This modified check allows us to overcome RFC1323's
9253 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9254 	 * p.869. In such cases, we can still calculate the RTT correctly
9255 	 * when RCV.NXT == Last.ACK.Sent.
9256 	 */
9257 	if ((to->to_flags & TOF_TS) != 0 &&
9258 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9259 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9260 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9261 		tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
9262 		tp->ts_recent = to->to_tsval;
9263 	}
9264 	/*
9265 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
9266 	 * is on (half-synchronized state), then queue data for later
9267 	 * processing; else drop segment and return.
9268 	 */
9269 	if ((thflags & TH_ACK) == 0) {
9270 		if (tp->t_flags & TF_NEEDSYN) {
9271 			return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9272 			    tiwin, thflags, nxt_pkt));
9273 		} else if (tp->t_flags & TF_ACKNOW) {
9274 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
9275 			bbr->r_wanted_output = 1;
9276 			return (ret_val);
9277 		} else {
9278 			ctf_do_drop(m, NULL);
9279 			return (0);
9280 		}
9281 	}
9282 	/*
9283 	 * Ack processing.
9284 	 */
9285 	if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
9286 		return (ret_val);
9287 	}
9288 	if (sbavail(&so->so_snd)) {
9289 		if (ctf_progress_timeout_check(tp, true)) {
9290 			bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
9291 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
9292 			return (1);
9293 		}
9294 	}
9295 	/* State changes only happen in bbr_process_data() */
9296 	return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9297 	    tiwin, thflags, nxt_pkt));
9298 }
9299 
9300 /*
9301  * Return value of 1, the TCB is unlocked and most
9302  * likely gone, return value of 0, the TCB is still
9303  * locked.
9304  */
9305 static int
9306 bbr_do_close_wait(struct mbuf *m, struct tcphdr *th, struct socket *so,
9307     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9308     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9309 {
9310 	struct tcp_bbr *bbr;
9311 	int32_t ret_val;
9312 
9313 	INP_WLOCK_ASSERT(tptoinpcb(tp));
9314 
9315 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9316 	ctf_calc_rwin(so, tp);
9317 	if ((thflags & TH_RST) ||
9318 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
9319 		return (ctf_process_rst(m, th, so, tp));
9320 	/*
9321 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
9322 	 * synchronized state.
9323 	 */
9324 	if (thflags & TH_SYN) {
9325 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
9326 		return (ret_val);
9327 	}
9328 	/*
9329 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9330 	 * it's less than ts_recent, drop it.
9331 	 */
9332 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9333 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9334 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9335 			return (ret_val);
9336 	}
9337 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9338 		return (ret_val);
9339 	}
9340 	/*
9341 	 * If last ACK falls within this segment's sequence numbers, record
9342 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
9343 	 * from the latest proposal of the tcplw@cray.com list (Braden
9344 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
9345 	 * with our earlier PAWS tests, so this check should be solely
9346 	 * predicated on the sequence space of this segment. 3) That we
9347 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9348 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9349 	 * SEG.Len, This modified check allows us to overcome RFC1323's
9350 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9351 	 * p.869. In such cases, we can still calculate the RTT correctly
9352 	 * when RCV.NXT == Last.ACK.Sent.
9353 	 */
9354 	if ((to->to_flags & TOF_TS) != 0 &&
9355 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9356 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9357 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9358 		tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
9359 		tp->ts_recent = to->to_tsval;
9360 	}
9361 	/*
9362 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
9363 	 * is on (half-synchronized state), then queue data for later
9364 	 * processing; else drop segment and return.
9365 	 */
9366 	if ((thflags & TH_ACK) == 0) {
9367 		if (tp->t_flags & TF_NEEDSYN) {
9368 			return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9369 			    tiwin, thflags, nxt_pkt));
9370 		} else if (tp->t_flags & TF_ACKNOW) {
9371 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
9372 			bbr->r_wanted_output = 1;
9373 			return (ret_val);
9374 		} else {
9375 			ctf_do_drop(m, NULL);
9376 			return (0);
9377 		}
9378 	}
9379 	/*
9380 	 * Ack processing.
9381 	 */
9382 	if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
9383 		return (ret_val);
9384 	}
9385 	if (sbavail(&so->so_snd)) {
9386 		if (ctf_progress_timeout_check(tp, true)) {
9387 			bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
9388 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
9389 			return (1);
9390 		}
9391 	}
9392 	return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9393 	    tiwin, thflags, nxt_pkt));
9394 }
9395 
9396 static int
9397 bbr_check_data_after_close(struct mbuf *m, struct tcp_bbr *bbr,
9398     struct tcpcb *tp, int32_t * tlen, struct tcphdr *th, struct socket *so)
9399 {
9400 
9401 	if (bbr->rc_allow_data_af_clo == 0) {
9402 close_now:
9403 		tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
9404 		/* tcp_close will kill the inp pre-log the Reset */
9405 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
9406 		tp = tcp_close(tp);
9407 		KMOD_TCPSTAT_INC(tcps_rcvafterclose);
9408 		ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, (*tlen));
9409 		return (1);
9410 	}
9411 	if (sbavail(&so->so_snd) == 0)
9412 		goto close_now;
9413 	/* Ok we allow data that is ignored and a followup reset */
9414 	tp->rcv_nxt = th->th_seq + *tlen;
9415 	tp->t_flags2 |= TF2_DROP_AF_DATA;
9416 	bbr->r_wanted_output = 1;
9417 	*tlen = 0;
9418 	return (0);
9419 }
9420 
9421 /*
9422  * Return value of 1, the TCB is unlocked and most
9423  * likely gone, return value of 0, the TCB is still
9424  * locked.
9425  */
9426 static int
9427 bbr_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, struct socket *so,
9428     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9429     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9430 {
9431 	int32_t ourfinisacked = 0;
9432 	int32_t ret_val;
9433 	struct tcp_bbr *bbr;
9434 
9435 	INP_WLOCK_ASSERT(tptoinpcb(tp));
9436 
9437 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9438 	ctf_calc_rwin(so, tp);
9439 	if ((thflags & TH_RST) ||
9440 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
9441 		return (ctf_process_rst(m, th, so, tp));
9442 	/*
9443 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
9444 	 * synchronized state.
9445 	 */
9446 	if (thflags & TH_SYN) {
9447 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
9448 		return (ret_val);
9449 	}
9450 	/*
9451 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9452 	 * it's less than ts_recent, drop it.
9453 	 */
9454 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9455 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9456 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9457 			return (ret_val);
9458 	}
9459 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9460 		return (ret_val);
9461 	}
9462 	/*
9463 	 * If new data are received on a connection after the user processes
9464 	 * are gone, then RST the other end.
9465 	 * We call a new function now so we might continue and setup
9466 	 * to reset at all data being ack'd.
9467 	 */
9468 	if ((tp->t_flags & TF_CLOSED) && tlen &&
9469 	    bbr_check_data_after_close(m, bbr, tp, &tlen, th, so))
9470 		return (1);
9471 	/*
9472 	 * If last ACK falls within this segment's sequence numbers, record
9473 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
9474 	 * from the latest proposal of the tcplw@cray.com list (Braden
9475 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
9476 	 * with our earlier PAWS tests, so this check should be solely
9477 	 * predicated on the sequence space of this segment. 3) That we
9478 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9479 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9480 	 * SEG.Len, This modified check allows us to overcome RFC1323's
9481 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9482 	 * p.869. In such cases, we can still calculate the RTT correctly
9483 	 * when RCV.NXT == Last.ACK.Sent.
9484 	 */
9485 	if ((to->to_flags & TOF_TS) != 0 &&
9486 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9487 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9488 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9489 		tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
9490 		tp->ts_recent = to->to_tsval;
9491 	}
9492 	/*
9493 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
9494 	 * is on (half-synchronized state), then queue data for later
9495 	 * processing; else drop segment and return.
9496 	 */
9497 	if ((thflags & TH_ACK) == 0) {
9498 		if (tp->t_flags & TF_NEEDSYN) {
9499 			return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9500 			    tiwin, thflags, nxt_pkt));
9501 		} else if (tp->t_flags & TF_ACKNOW) {
9502 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
9503 			bbr->r_wanted_output = 1;
9504 			return (ret_val);
9505 		} else {
9506 			ctf_do_drop(m, NULL);
9507 			return (0);
9508 		}
9509 	}
9510 	/*
9511 	 * Ack processing.
9512 	 */
9513 	if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
9514 		return (ret_val);
9515 	}
9516 	if (ourfinisacked) {
9517 		/*
9518 		 * If we can't receive any more data, then closing user can
9519 		 * proceed. Starting the timer is contrary to the
9520 		 * specification, but if we don't get a FIN we'll hang
9521 		 * forever.
9522 		 *
9523 		 * XXXjl: we should release the tp also, and use a
9524 		 * compressed state.
9525 		 */
9526 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
9527 			soisdisconnected(so);
9528 			tcp_timer_activate(tp, TT_2MSL,
9529 			    (tcp_fast_finwait2_recycle ?
9530 			    tcp_finwait2_timeout :
9531 			    TP_MAXIDLE(tp)));
9532 		}
9533 		tcp_state_change(tp, TCPS_FIN_WAIT_2);
9534 	}
9535 	if (sbavail(&so->so_snd)) {
9536 		if (ctf_progress_timeout_check(tp, true)) {
9537 			bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
9538 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
9539 			return (1);
9540 		}
9541 	}
9542 	return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9543 	    tiwin, thflags, nxt_pkt));
9544 }
9545 
9546 /*
9547  * Return value of 1, the TCB is unlocked and most
9548  * likely gone, return value of 0, the TCB is still
9549  * locked.
9550  */
9551 static int
9552 bbr_do_closing(struct mbuf *m, struct tcphdr *th, struct socket *so,
9553     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9554     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9555 {
9556 	int32_t ourfinisacked = 0;
9557 	int32_t ret_val;
9558 	struct tcp_bbr *bbr;
9559 
9560 	INP_WLOCK_ASSERT(tptoinpcb(tp));
9561 
9562 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9563 	ctf_calc_rwin(so, tp);
9564 	if ((thflags & TH_RST) ||
9565 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
9566 		return (ctf_process_rst(m, th, so, tp));
9567 	/*
9568 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
9569 	 * synchronized state.
9570 	 */
9571 	if (thflags & TH_SYN) {
9572 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
9573 		return (ret_val);
9574 	}
9575 	/*
9576 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9577 	 * it's less than ts_recent, drop it.
9578 	 */
9579 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9580 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9581 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9582 			return (ret_val);
9583 	}
9584 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9585 		return (ret_val);
9586 	}
9587 	/*
9588 	 * If last ACK falls within this segment's sequence numbers, record
9589 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
9590 	 * from the latest proposal of the tcplw@cray.com list (Braden
9591 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
9592 	 * with our earlier PAWS tests, so this check should be solely
9593 	 * predicated on the sequence space of this segment. 3) That we
9594 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9595 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9596 	 * SEG.Len, This modified check allows us to overcome RFC1323's
9597 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9598 	 * p.869. In such cases, we can still calculate the RTT correctly
9599 	 * when RCV.NXT == Last.ACK.Sent.
9600 	 */
9601 	if ((to->to_flags & TOF_TS) != 0 &&
9602 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9603 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9604 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9605 		tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
9606 		tp->ts_recent = to->to_tsval;
9607 	}
9608 	/*
9609 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
9610 	 * is on (half-synchronized state), then queue data for later
9611 	 * processing; else drop segment and return.
9612 	 */
9613 	if ((thflags & TH_ACK) == 0) {
9614 		if (tp->t_flags & TF_NEEDSYN) {
9615 			return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9616 			    tiwin, thflags, nxt_pkt));
9617 		} else if (tp->t_flags & TF_ACKNOW) {
9618 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
9619 			bbr->r_wanted_output = 1;
9620 			return (ret_val);
9621 		} else {
9622 			ctf_do_drop(m, NULL);
9623 			return (0);
9624 		}
9625 	}
9626 	/*
9627 	 * Ack processing.
9628 	 */
9629 	if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
9630 		return (ret_val);
9631 	}
9632 	if (ourfinisacked) {
9633 		tcp_twstart(tp);
9634 		m_freem(m);
9635 		return (1);
9636 	}
9637 	if (sbavail(&so->so_snd)) {
9638 		if (ctf_progress_timeout_check(tp, true)) {
9639 			bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
9640 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
9641 			return (1);
9642 		}
9643 	}
9644 	return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9645 	    tiwin, thflags, nxt_pkt));
9646 }
9647 
9648 /*
9649  * Return value of 1, the TCB is unlocked and most
9650  * likely gone, return value of 0, the TCB is still
9651  * locked.
9652  */
9653 static int
9654 bbr_do_lastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
9655     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9656     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9657 {
9658 	int32_t ourfinisacked = 0;
9659 	int32_t ret_val;
9660 	struct tcp_bbr *bbr;
9661 
9662 	INP_WLOCK_ASSERT(tptoinpcb(tp));
9663 
9664 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9665 	ctf_calc_rwin(so, tp);
9666 	if ((thflags & TH_RST) ||
9667 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
9668 		return (ctf_process_rst(m, th, so, tp));
9669 	/*
9670 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
9671 	 * synchronized state.
9672 	 */
9673 	if (thflags & TH_SYN) {
9674 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
9675 		return (ret_val);
9676 	}
9677 	/*
9678 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9679 	 * it's less than ts_recent, drop it.
9680 	 */
9681 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9682 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9683 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9684 			return (ret_val);
9685 	}
9686 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9687 		return (ret_val);
9688 	}
9689 	/*
9690 	 * If last ACK falls within this segment's sequence numbers, record
9691 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
9692 	 * from the latest proposal of the tcplw@cray.com list (Braden
9693 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
9694 	 * with our earlier PAWS tests, so this check should be solely
9695 	 * predicated on the sequence space of this segment. 3) That we
9696 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9697 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9698 	 * SEG.Len, This modified check allows us to overcome RFC1323's
9699 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9700 	 * p.869. In such cases, we can still calculate the RTT correctly
9701 	 * when RCV.NXT == Last.ACK.Sent.
9702 	 */
9703 	if ((to->to_flags & TOF_TS) != 0 &&
9704 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9705 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9706 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9707 		tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
9708 		tp->ts_recent = to->to_tsval;
9709 	}
9710 	/*
9711 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
9712 	 * is on (half-synchronized state), then queue data for later
9713 	 * processing; else drop segment and return.
9714 	 */
9715 	if ((thflags & TH_ACK) == 0) {
9716 		if (tp->t_flags & TF_NEEDSYN) {
9717 			return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9718 			    tiwin, thflags, nxt_pkt));
9719 		} else if (tp->t_flags & TF_ACKNOW) {
9720 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
9721 			bbr->r_wanted_output = 1;
9722 			return (ret_val);
9723 		} else {
9724 			ctf_do_drop(m, NULL);
9725 			return (0);
9726 		}
9727 	}
9728 	/*
9729 	 * case TCPS_LAST_ACK: Ack processing.
9730 	 */
9731 	if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
9732 		return (ret_val);
9733 	}
9734 	if (ourfinisacked) {
9735 		tp = tcp_close(tp);
9736 		ctf_do_drop(m, tp);
9737 		return (1);
9738 	}
9739 	if (sbavail(&so->so_snd)) {
9740 		if (ctf_progress_timeout_check(tp, true)) {
9741 			bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
9742 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
9743 			return (1);
9744 		}
9745 	}
9746 	return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9747 	    tiwin, thflags, nxt_pkt));
9748 }
9749 
9750 /*
9751  * Return value of 1, the TCB is unlocked and most
9752  * likely gone, return value of 0, the TCB is still
9753  * locked.
9754  */
9755 static int
9756 bbr_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, struct socket *so,
9757     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9758     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9759 {
9760 	int32_t ourfinisacked = 0;
9761 	int32_t ret_val;
9762 	struct tcp_bbr *bbr;
9763 
9764 	INP_WLOCK_ASSERT(tptoinpcb(tp));
9765 
9766 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9767 	ctf_calc_rwin(so, tp);
9768 	/* Reset receive buffer auto scaling when not in bulk receive mode. */
9769 	if ((thflags & TH_RST) ||
9770 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
9771 		return (ctf_process_rst(m, th, so, tp));
9772 
9773 	/*
9774 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
9775 	 * synchronized state.
9776 	 */
9777 	if (thflags & TH_SYN) {
9778 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
9779 		return (ret_val);
9780 	}
9781 	/*
9782 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9783 	 * it's less than ts_recent, drop it.
9784 	 */
9785 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9786 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9787 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9788 			return (ret_val);
9789 	}
9790 	if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9791 		return (ret_val);
9792 	}
9793 	/*
9794 	 * If new data are received on a connection after the user processes
9795 	 * are gone, then we may RST the other end depending on the outcome
9796 	 * of bbr_check_data_after_close.
9797 	 * We call a new function now so we might continue and setup
9798 	 * to reset at all data being ack'd.
9799 	 */
9800 	if ((tp->t_flags & TF_CLOSED) && tlen &&
9801 	    bbr_check_data_after_close(m, bbr, tp, &tlen, th, so))
9802 		return (1);
9803 	/*
9804 	 * If last ACK falls within this segment's sequence numbers, record
9805 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
9806 	 * from the latest proposal of the tcplw@cray.com list (Braden
9807 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
9808 	 * with our earlier PAWS tests, so this check should be solely
9809 	 * predicated on the sequence space of this segment. 3) That we
9810 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9811 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9812 	 * SEG.Len, This modified check allows us to overcome RFC1323's
9813 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9814 	 * p.869. In such cases, we can still calculate the RTT correctly
9815 	 * when RCV.NXT == Last.ACK.Sent.
9816 	 */
9817 	if ((to->to_flags & TOF_TS) != 0 &&
9818 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9819 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9820 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9821 		tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
9822 		tp->ts_recent = to->to_tsval;
9823 	}
9824 	/*
9825 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
9826 	 * is on (half-synchronized state), then queue data for later
9827 	 * processing; else drop segment and return.
9828 	 */
9829 	if ((thflags & TH_ACK) == 0) {
9830 		if (tp->t_flags & TF_NEEDSYN) {
9831 			return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9832 			    tiwin, thflags, nxt_pkt));
9833 		} else if (tp->t_flags & TF_ACKNOW) {
9834 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
9835 			bbr->r_wanted_output = 1;
9836 			return (ret_val);
9837 		} else {
9838 			ctf_do_drop(m, NULL);
9839 			return (0);
9840 		}
9841 	}
9842 	/*
9843 	 * Ack processing.
9844 	 */
9845 	if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
9846 		return (ret_val);
9847 	}
9848 	if (sbavail(&so->so_snd)) {
9849 		if (ctf_progress_timeout_check(tp, true)) {
9850 			bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
9851 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
9852 			return (1);
9853 		}
9854 	}
9855 	return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9856 	    tiwin, thflags, nxt_pkt));
9857 }
9858 
9859 static void
9860 bbr_stop_all_timers(struct tcpcb *tp, struct tcp_bbr *bbr)
9861 {
9862 	/*
9863 	 * Assure no timers are running.
9864 	 */
9865 	if (tcp_timer_active(tp, TT_PERSIST)) {
9866 		/* We enter in persists, set the flag appropriately */
9867 		bbr->rc_in_persist = 1;
9868 	}
9869 	if (tcp_in_hpts(bbr->rc_tp)) {
9870 		tcp_hpts_remove(bbr->rc_tp);
9871 	}
9872 }
9873 
9874 static void
9875 bbr_google_mode_on(struct tcp_bbr *bbr)
9876 {
9877 	bbr->rc_use_google = 1;
9878 	bbr->rc_no_pacing = 0;
9879 	bbr->r_ctl.bbr_google_discount = bbr_google_discount;
9880 	bbr->r_use_policer = bbr_policer_detection_enabled;
9881 	bbr->r_ctl.rc_probertt_int = (USECS_IN_SECOND * 10);
9882 	bbr->bbr_use_rack_cheat = 0;
9883 	bbr->r_ctl.rc_incr_tmrs = 0;
9884 	bbr->r_ctl.rc_inc_tcp_oh = 0;
9885 	bbr->r_ctl.rc_inc_ip_oh = 0;
9886 	bbr->r_ctl.rc_inc_enet_oh = 0;
9887 	reset_time(&bbr->r_ctl.rc_delrate,
9888 		   BBR_NUM_RTTS_FOR_GOOG_DEL_LIMIT);
9889 	reset_time_small(&bbr->r_ctl.rc_rttprop,
9890 			 (11 * USECS_IN_SECOND));
9891 	tcp_bbr_tso_size_check(bbr, tcp_get_usecs(&bbr->rc_tv));
9892 }
9893 
9894 static void
9895 bbr_google_mode_off(struct tcp_bbr *bbr)
9896 {
9897 	bbr->rc_use_google = 0;
9898 	bbr->r_ctl.bbr_google_discount = 0;
9899 	bbr->no_pacing_until = bbr_no_pacing_until;
9900 	bbr->r_use_policer = 0;
9901 	if (bbr->no_pacing_until)
9902 		bbr->rc_no_pacing = 1;
9903 	else
9904 		bbr->rc_no_pacing = 0;
9905 	if (bbr_use_rack_resend_cheat)
9906 		bbr->bbr_use_rack_cheat = 1;
9907 	else
9908 		bbr->bbr_use_rack_cheat = 0;
9909 	if (bbr_incr_timers)
9910 		bbr->r_ctl.rc_incr_tmrs = 1;
9911 	else
9912 		bbr->r_ctl.rc_incr_tmrs = 0;
9913 	if (bbr_include_tcp_oh)
9914 		bbr->r_ctl.rc_inc_tcp_oh = 1;
9915 	else
9916 		bbr->r_ctl.rc_inc_tcp_oh = 0;
9917 	if (bbr_include_ip_oh)
9918 		bbr->r_ctl.rc_inc_ip_oh = 1;
9919 	else
9920 		bbr->r_ctl.rc_inc_ip_oh = 0;
9921 	if (bbr_include_enet_oh)
9922 		bbr->r_ctl.rc_inc_enet_oh = 1;
9923 	else
9924 		bbr->r_ctl.rc_inc_enet_oh = 0;
9925 	bbr->r_ctl.rc_probertt_int = bbr_rtt_probe_limit;
9926 	reset_time(&bbr->r_ctl.rc_delrate,
9927 		   bbr_num_pktepo_for_del_limit);
9928 	reset_time_small(&bbr->r_ctl.rc_rttprop,
9929 			 (bbr_filter_len_sec * USECS_IN_SECOND));
9930 	tcp_bbr_tso_size_check(bbr, tcp_get_usecs(&bbr->rc_tv));
9931 }
9932 /*
9933  * Return 0 on success, non-zero on failure
9934  * which indicates the error (usually no memory).
9935  */
9936 static int
9937 bbr_init(struct tcpcb *tp, void **ptr)
9938 {
9939 	struct inpcb *inp = tptoinpcb(tp);
9940 	struct tcp_bbr *bbr = NULL;
9941 	uint32_t cts;
9942 
9943 	tcp_hpts_init(tp);
9944 
9945 	*ptr = uma_zalloc(bbr_pcb_zone, (M_NOWAIT | M_ZERO));
9946 	if (*ptr == NULL) {
9947 		/*
9948 		 * We need to allocate memory but cant. The INP and INP_INFO
9949 		 * locks and they are recursive (happens during setup. So a
9950 		 * scheme to drop the locks fails :(
9951 		 *
9952 		 */
9953 		return (ENOMEM);
9954 	}
9955 	bbr = (struct tcp_bbr *)*ptr;
9956 	bbr->rtt_valid = 0;
9957 	tp->t_flags2 |= TF2_CANNOT_DO_ECN;
9958 	tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
9959 	/* Take off any undesired flags */
9960 	tp->t_flags2 &= ~TF2_MBUF_QUEUE_READY;
9961 	tp->t_flags2 &= ~TF2_DONT_SACK_QUEUE;
9962 	tp->t_flags2 &= ~TF2_MBUF_ACKCMP;
9963 	tp->t_flags2 &= ~TF2_MBUF_L_ACKS;
9964 
9965 	TAILQ_INIT(&bbr->r_ctl.rc_map);
9966 	TAILQ_INIT(&bbr->r_ctl.rc_free);
9967 	TAILQ_INIT(&bbr->r_ctl.rc_tmap);
9968 	bbr->rc_tp = tp;
9969 	bbr->rc_inp = inp;
9970 	cts = tcp_get_usecs(&bbr->rc_tv);
9971 	tp->t_acktime = 0;
9972 	bbr->rc_allow_data_af_clo = bbr_ignore_data_after_close;
9973 	bbr->r_ctl.rc_reorder_fade = bbr_reorder_fade;
9974 	bbr->rc_tlp_threshold = bbr_tlp_thresh;
9975 	bbr->r_ctl.rc_reorder_shift = bbr_reorder_thresh;
9976 	bbr->r_ctl.rc_pkt_delay = bbr_pkt_delay;
9977 	bbr->r_ctl.rc_min_to = bbr_min_to;
9978 	bbr->rc_bbr_state = BBR_STATE_STARTUP;
9979 	bbr->r_ctl.bbr_lost_at_state = 0;
9980 	bbr->r_ctl.rc_lost_at_startup = 0;
9981 	bbr->rc_all_timers_stopped = 0;
9982 	bbr->r_ctl.rc_bbr_lastbtlbw = 0;
9983 	bbr->r_ctl.rc_pkt_epoch_del = 0;
9984 	bbr->r_ctl.rc_pkt_epoch = 0;
9985 	bbr->r_ctl.rc_lowest_rtt = 0xffffffff;
9986 	bbr->r_ctl.rc_bbr_hptsi_gain = bbr_high_gain;
9987 	bbr->r_ctl.rc_bbr_cwnd_gain = bbr_high_gain;
9988 	bbr->r_ctl.rc_went_idle_time = cts;
9989 	bbr->rc_pacer_started = cts;
9990 	bbr->r_ctl.rc_pkt_epoch_time = cts;
9991 	bbr->r_ctl.rc_rcvtime = cts;
9992 	bbr->r_ctl.rc_bbr_state_time = cts;
9993 	bbr->r_ctl.rc_del_time = cts;
9994 	bbr->r_ctl.rc_tlp_rxt_last_time = cts;
9995 	bbr->r_ctl.last_in_probertt = cts;
9996 	bbr->skip_gain = 0;
9997 	bbr->gain_is_limited = 0;
9998 	bbr->no_pacing_until = bbr_no_pacing_until;
9999 	if (bbr->no_pacing_until)
10000 		bbr->rc_no_pacing = 1;
10001 	if (bbr_use_google_algo) {
10002 		bbr->rc_no_pacing = 0;
10003 		bbr->rc_use_google = 1;
10004 		bbr->r_ctl.bbr_google_discount = bbr_google_discount;
10005 		bbr->r_use_policer = bbr_policer_detection_enabled;
10006 	} else {
10007 		bbr->rc_use_google = 0;
10008 		bbr->r_ctl.bbr_google_discount = 0;
10009 		bbr->r_use_policer = 0;
10010 	}
10011 	if (bbr_ts_limiting)
10012 		bbr->rc_use_ts_limit = 1;
10013 	else
10014 		bbr->rc_use_ts_limit = 0;
10015 	if (bbr_ts_can_raise)
10016 		bbr->ts_can_raise = 1;
10017 	else
10018 		bbr->ts_can_raise = 0;
10019 	if (V_tcp_delack_enabled == 1)
10020 		tp->t_delayed_ack = 2;
10021 	else if (V_tcp_delack_enabled == 0)
10022 		tp->t_delayed_ack = 0;
10023 	else if (V_tcp_delack_enabled < 100)
10024 		tp->t_delayed_ack = V_tcp_delack_enabled;
10025 	else
10026 		tp->t_delayed_ack = 2;
10027 	if (bbr->rc_use_google == 0)
10028 		bbr->r_ctl.rc_probertt_int = bbr_rtt_probe_limit;
10029 	else
10030 		bbr->r_ctl.rc_probertt_int = (USECS_IN_SECOND * 10);
10031 	bbr->r_ctl.rc_min_rto_ms = bbr_rto_min_ms;
10032 	bbr->rc_max_rto_sec = bbr_rto_max_sec;
10033 	bbr->rc_init_win = bbr_def_init_win;
10034 	if (tp->t_flags & TF_REQ_TSTMP)
10035 		bbr->rc_last_options = TCP_TS_OVERHEAD;
10036 	bbr->r_ctl.rc_pace_max_segs = tp->t_maxseg - bbr->rc_last_options;
10037 	bbr->r_ctl.rc_high_rwnd = tp->snd_wnd;
10038 	bbr->r_init_rtt = 1;
10039 
10040 	counter_u64_add(bbr_flows_nohdwr_pacing, 1);
10041 	if (bbr_allow_hdwr_pacing)
10042 		bbr->bbr_hdw_pace_ena = 1;
10043 	else
10044 		bbr->bbr_hdw_pace_ena = 0;
10045 	if (bbr_sends_full_iwnd)
10046 		bbr->bbr_init_win_cheat = 1;
10047 	else
10048 		bbr->bbr_init_win_cheat = 0;
10049 	bbr->r_ctl.bbr_utter_max = bbr_hptsi_utter_max;
10050 	bbr->r_ctl.rc_drain_pg = bbr_drain_gain;
10051 	bbr->r_ctl.rc_startup_pg = bbr_high_gain;
10052 	bbr->rc_loss_exit = bbr_exit_startup_at_loss;
10053 	bbr->r_ctl.bbr_rttprobe_gain_val = bbr_rttprobe_gain;
10054 	bbr->r_ctl.bbr_hptsi_per_second = bbr_hptsi_per_second;
10055 	bbr->r_ctl.bbr_hptsi_segments_delay_tar = bbr_hptsi_segments_delay_tar;
10056 	bbr->r_ctl.bbr_hptsi_segments_max = bbr_hptsi_segments_max;
10057 	bbr->r_ctl.bbr_hptsi_segments_floor = bbr_hptsi_segments_floor;
10058 	bbr->r_ctl.bbr_hptsi_bytes_min = bbr_hptsi_bytes_min;
10059 	bbr->r_ctl.bbr_cross_over = bbr_cross_over;
10060 	bbr->r_ctl.rc_rtt_shrinks = cts;
10061 	if (bbr->rc_use_google) {
10062 		setup_time_filter(&bbr->r_ctl.rc_delrate,
10063 				  FILTER_TYPE_MAX,
10064 				  BBR_NUM_RTTS_FOR_GOOG_DEL_LIMIT);
10065 		setup_time_filter_small(&bbr->r_ctl.rc_rttprop,
10066 					FILTER_TYPE_MIN, (11 * USECS_IN_SECOND));
10067 	} else {
10068 		setup_time_filter(&bbr->r_ctl.rc_delrate,
10069 				  FILTER_TYPE_MAX,
10070 				  bbr_num_pktepo_for_del_limit);
10071 		setup_time_filter_small(&bbr->r_ctl.rc_rttprop,
10072 					FILTER_TYPE_MIN, (bbr_filter_len_sec * USECS_IN_SECOND));
10073 	}
10074 	bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_INIT, 0);
10075 	if (bbr_uses_idle_restart)
10076 		bbr->rc_use_idle_restart = 1;
10077 	else
10078 		bbr->rc_use_idle_restart = 0;
10079 	bbr->r_ctl.rc_bbr_cur_del_rate = 0;
10080 	bbr->r_ctl.rc_initial_hptsi_bw = bbr_initial_bw_bps;
10081 	if (bbr_resends_use_tso)
10082 		bbr->rc_resends_use_tso = 1;
10083 	if (tp->snd_una != tp->snd_max) {
10084 		/* Create a send map for the current outstanding data */
10085 		struct bbr_sendmap *rsm;
10086 
10087 		rsm = bbr_alloc(bbr);
10088 		if (rsm == NULL) {
10089 			uma_zfree(bbr_pcb_zone, *ptr);
10090 			*ptr = NULL;
10091 			return (ENOMEM);
10092 		}
10093 		rsm->r_rtt_not_allowed = 1;
10094 		rsm->r_tim_lastsent[0] = cts;
10095 		rsm->r_rtr_cnt = 1;
10096 		rsm->r_rtr_bytes = 0;
10097 		rsm->r_start = tp->snd_una;
10098 		rsm->r_end = tp->snd_max;
10099 		rsm->r_dupack = 0;
10100 		rsm->r_delivered = bbr->r_ctl.rc_delivered;
10101 		rsm->r_ts_valid = 0;
10102 		rsm->r_del_ack_ts = tp->ts_recent;
10103 		rsm->r_del_time = cts;
10104 		if (bbr->r_ctl.r_app_limited_until)
10105 			rsm->r_app_limited = 1;
10106 		else
10107 			rsm->r_app_limited = 0;
10108 		TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_map, rsm, r_next);
10109 		TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
10110 		rsm->r_in_tmap = 1;
10111 		if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW)
10112 			rsm->r_bbr_state = bbr_state_val(bbr);
10113 		else
10114 			rsm->r_bbr_state = 8;
10115 	}
10116 	if (bbr_use_rack_resend_cheat && (bbr->rc_use_google == 0))
10117 		bbr->bbr_use_rack_cheat = 1;
10118 	if (bbr_incr_timers && (bbr->rc_use_google == 0))
10119 		bbr->r_ctl.rc_incr_tmrs = 1;
10120 	if (bbr_include_tcp_oh && (bbr->rc_use_google == 0))
10121 		bbr->r_ctl.rc_inc_tcp_oh = 1;
10122 	if (bbr_include_ip_oh && (bbr->rc_use_google == 0))
10123 		bbr->r_ctl.rc_inc_ip_oh = 1;
10124 	if (bbr_include_enet_oh && (bbr->rc_use_google == 0))
10125 		bbr->r_ctl.rc_inc_enet_oh = 1;
10126 
10127 	bbr_log_type_statechange(bbr, cts, __LINE__);
10128 	if (TCPS_HAVEESTABLISHED(tp->t_state) &&
10129 	    (tp->t_srtt)) {
10130 		uint32_t rtt;
10131 
10132 		rtt = (TICKS_2_USEC(tp->t_srtt) >> TCP_RTT_SHIFT);
10133 		apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, cts);
10134 	}
10135 	/* announce the settings and state */
10136 	bbr_log_settings_change(bbr, BBR_RECOVERY_LOWRTT);
10137 	tcp_bbr_tso_size_check(bbr, cts);
10138 	/*
10139 	 * Now call the generic function to start a timer. This will place
10140 	 * the TCB on the hptsi wheel if a timer is needed with appropriate
10141 	 * flags.
10142 	 */
10143 	bbr_stop_all_timers(tp, bbr);
10144 	/*
10145 	 * Validate the timers are not in usec, if they are convert.
10146 	 * BBR should in theory move to USEC and get rid of a
10147 	 * lot of the TICKS_2 calls.. but for now we stay
10148 	 * with tick timers.
10149 	 */
10150 	tcp_change_time_units(tp, TCP_TMR_GRANULARITY_TICKS);
10151 	TCPT_RANGESET(tp->t_rxtcur,
10152 	    ((tp->t_srtt >> 2) + tp->t_rttvar) >> 1,
10153 	    tp->t_rttmin, TCPTV_REXMTMAX);
10154 	bbr_start_hpts_timer(bbr, tp, cts, 5, 0, 0);
10155 	return (0);
10156 }
10157 
10158 /*
10159  * Return 0 if we can accept the connection. Return
10160  * non-zero if we can't handle the connection. A EAGAIN
10161  * means you need to wait until the connection is up.
10162  * a EADDRNOTAVAIL means we can never handle the connection
10163  * (no SACK).
10164  */
10165 static int
10166 bbr_handoff_ok(struct tcpcb *tp)
10167 {
10168 	if ((tp->t_state == TCPS_CLOSED) ||
10169 	    (tp->t_state == TCPS_LISTEN)) {
10170 		/* Sure no problem though it may not stick */
10171 		return (0);
10172 	}
10173 	if ((tp->t_state == TCPS_SYN_SENT) ||
10174 	    (tp->t_state == TCPS_SYN_RECEIVED)) {
10175 		/*
10176 		 * We really don't know you have to get to ESTAB or beyond
10177 		 * to tell.
10178 		 */
10179 		return (EAGAIN);
10180 	}
10181 	if (tp->t_flags & TF_SENTFIN)
10182 		return (EINVAL);
10183 	if ((tp->t_flags & TF_SACK_PERMIT) || bbr_sack_not_required) {
10184 		return (0);
10185 	}
10186 	/*
10187 	 * If we reach here we don't do SACK on this connection so we can
10188 	 * never do rack.
10189 	 */
10190 	return (EINVAL);
10191 }
10192 
10193 static void
10194 bbr_fini(struct tcpcb *tp, int32_t tcb_is_purged)
10195 {
10196 	if (tp->t_fb_ptr) {
10197 		uint32_t calc;
10198 		struct tcp_bbr *bbr;
10199 		struct bbr_sendmap *rsm;
10200 
10201 		bbr = (struct tcp_bbr *)tp->t_fb_ptr;
10202 		if (bbr->r_ctl.crte)
10203 			tcp_rel_pacing_rate(bbr->r_ctl.crte, bbr->rc_tp);
10204 		bbr_log_flowend(bbr);
10205 		bbr->rc_tp = NULL;
10206 		if (bbr->bbr_hdrw_pacing)
10207 			counter_u64_add(bbr_flows_whdwr_pacing, -1);
10208 		else
10209 			counter_u64_add(bbr_flows_nohdwr_pacing, -1);
10210 		if (bbr->r_ctl.crte != NULL) {
10211 			tcp_rel_pacing_rate(bbr->r_ctl.crte, tp);
10212 			bbr->r_ctl.crte = NULL;
10213 		}
10214 		rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
10215 		while (rsm) {
10216 			TAILQ_REMOVE(&bbr->r_ctl.rc_map, rsm, r_next);
10217 			uma_zfree(bbr_zone, rsm);
10218 			rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
10219 		}
10220 		rsm = TAILQ_FIRST(&bbr->r_ctl.rc_free);
10221 		while (rsm) {
10222 			TAILQ_REMOVE(&bbr->r_ctl.rc_free, rsm, r_next);
10223 			uma_zfree(bbr_zone, rsm);
10224 			rsm = TAILQ_FIRST(&bbr->r_ctl.rc_free);
10225 		}
10226 		calc = bbr->r_ctl.rc_high_rwnd - bbr->r_ctl.rc_init_rwnd;
10227 		if (calc > (bbr->r_ctl.rc_init_rwnd / 10))
10228 			BBR_STAT_INC(bbr_dynamic_rwnd);
10229 		else
10230 			BBR_STAT_INC(bbr_static_rwnd);
10231 		bbr->r_ctl.rc_free_cnt = 0;
10232 		uma_zfree(bbr_pcb_zone, tp->t_fb_ptr);
10233 		tp->t_fb_ptr = NULL;
10234 	}
10235 	/* Make sure snd_nxt is correctly set */
10236 	tp->snd_nxt = tp->snd_max;
10237 }
10238 
10239 static void
10240 bbr_set_state(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t win)
10241 {
10242 	switch (tp->t_state) {
10243 	case TCPS_SYN_SENT:
10244 		bbr->r_state = TCPS_SYN_SENT;
10245 		bbr->r_substate = bbr_do_syn_sent;
10246 		break;
10247 	case TCPS_SYN_RECEIVED:
10248 		bbr->r_state = TCPS_SYN_RECEIVED;
10249 		bbr->r_substate = bbr_do_syn_recv;
10250 		break;
10251 	case TCPS_ESTABLISHED:
10252 		bbr->r_ctl.rc_init_rwnd = max(win, bbr->rc_tp->snd_wnd);
10253 		bbr->r_state = TCPS_ESTABLISHED;
10254 		bbr->r_substate = bbr_do_established;
10255 		break;
10256 	case TCPS_CLOSE_WAIT:
10257 		bbr->r_state = TCPS_CLOSE_WAIT;
10258 		bbr->r_substate = bbr_do_close_wait;
10259 		break;
10260 	case TCPS_FIN_WAIT_1:
10261 		bbr->r_state = TCPS_FIN_WAIT_1;
10262 		bbr->r_substate = bbr_do_fin_wait_1;
10263 		break;
10264 	case TCPS_CLOSING:
10265 		bbr->r_state = TCPS_CLOSING;
10266 		bbr->r_substate = bbr_do_closing;
10267 		break;
10268 	case TCPS_LAST_ACK:
10269 		bbr->r_state = TCPS_LAST_ACK;
10270 		bbr->r_substate = bbr_do_lastack;
10271 		break;
10272 	case TCPS_FIN_WAIT_2:
10273 		bbr->r_state = TCPS_FIN_WAIT_2;
10274 		bbr->r_substate = bbr_do_fin_wait_2;
10275 		break;
10276 	case TCPS_LISTEN:
10277 	case TCPS_CLOSED:
10278 	case TCPS_TIME_WAIT:
10279 	default:
10280 		break;
10281 	};
10282 }
10283 
10284 static void
10285 bbr_substate_change(struct tcp_bbr *bbr, uint32_t cts, int32_t line, int dolog)
10286 {
10287 	/*
10288 	 * Now what state are we going into now? Is there adjustments
10289 	 * needed?
10290 	 */
10291 	int32_t old_state;
10292 
10293 	old_state = bbr_state_val(bbr);
10294 	if (bbr_state_val(bbr) == BBR_SUB_LEVEL1) {
10295 		/* Save the lowest srtt we saw in our end of the sub-state */
10296 		bbr->rc_hit_state_1 = 0;
10297 		if (bbr->r_ctl.bbr_smallest_srtt_this_state != 0xffffffff)
10298 			bbr->r_ctl.bbr_smallest_srtt_state2 = bbr->r_ctl.bbr_smallest_srtt_this_state;
10299 	}
10300 	bbr->rc_bbr_substate++;
10301 	if (bbr_state_val(bbr) == BBR_SUB_GAIN) {
10302 		/*
10303 		 * We enter the gain(5/4) cycle (possibly less if
10304 		 * shallow buffer detection is enabled)
10305 		 */
10306 		if (bbr->skip_gain) {
10307 			/*
10308 			 * Hardware pacing has set our rate to
10309 			 * the max and limited our b/w just
10310 			 * do level i.e. no gain.
10311 			 */
10312 			bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[BBR_SUB_LEVEL1];
10313 		} else if (bbr->gain_is_limited &&
10314 			   bbr->bbr_hdrw_pacing &&
10315 			   bbr->r_ctl.crte) {
10316 			/*
10317 			 * We can't gain above the hardware pacing
10318 			 * rate which is less than our rate + the gain
10319 			 * calculate the gain needed to reach the hardware
10320 			 * pacing rate..
10321 			 */
10322 			uint64_t bw, rate, gain_calc;
10323 
10324 			bw = bbr_get_bw(bbr);
10325 			rate = bbr->r_ctl.crte->rate;
10326 			if ((rate > bw) &&
10327 			    (((bw *  (uint64_t)bbr_hptsi_gain[BBR_SUB_GAIN]) / (uint64_t)BBR_UNIT) > rate)) {
10328 				gain_calc = (rate * BBR_UNIT) / bw;
10329 				if (gain_calc < BBR_UNIT)
10330 					gain_calc = BBR_UNIT;
10331 				bbr->r_ctl.rc_bbr_hptsi_gain = (uint16_t)gain_calc;
10332 			} else {
10333 				bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[BBR_SUB_GAIN];
10334 			}
10335 		} else
10336 			bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[BBR_SUB_GAIN];
10337 		if ((bbr->rc_use_google == 0) && (bbr_gain_to_target == 0)) {
10338 			bbr->r_ctl.rc_bbr_state_atflight = cts;
10339 		} else
10340 			bbr->r_ctl.rc_bbr_state_atflight = 0;
10341 	} else if (bbr_state_val(bbr) == BBR_SUB_DRAIN) {
10342 		bbr->rc_hit_state_1 = 1;
10343 		bbr->r_ctl.rc_exta_time_gd = 0;
10344 		bbr->r_ctl.flightsize_at_drain = ctf_flight_size(bbr->rc_tp,
10345 						     (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
10346 		if (bbr_state_drain_2_tar) {
10347 			bbr->r_ctl.rc_bbr_state_atflight = 0;
10348 		} else
10349 			bbr->r_ctl.rc_bbr_state_atflight = cts;
10350 		bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[BBR_SUB_DRAIN];
10351 	} else {
10352 		/* All other cycles hit here 2-7 */
10353 		if ((old_state == BBR_SUB_DRAIN) && bbr->rc_hit_state_1) {
10354 			if (bbr_sub_drain_slam_cwnd &&
10355 			    (bbr->rc_use_google == 0) &&
10356 			    (bbr->rc_tp->snd_cwnd < bbr->r_ctl.rc_saved_cwnd)) {
10357 				bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_saved_cwnd;
10358 				bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10359 			}
10360 			if ((cts - bbr->r_ctl.rc_bbr_state_time) > bbr_get_rtt(bbr, BBR_RTT_PROP))
10361 				bbr->r_ctl.rc_exta_time_gd += ((cts - bbr->r_ctl.rc_bbr_state_time) -
10362 							       bbr_get_rtt(bbr, BBR_RTT_PROP));
10363 			else
10364 				bbr->r_ctl.rc_exta_time_gd = 0;
10365 			if (bbr->r_ctl.rc_exta_time_gd) {
10366 				bbr->r_ctl.rc_level_state_extra = bbr->r_ctl.rc_exta_time_gd;
10367 				/* Now chop up the time for each state (div by 7) */
10368 				bbr->r_ctl.rc_level_state_extra /= 7;
10369 				if (bbr_rand_ot && bbr->r_ctl.rc_level_state_extra) {
10370 					/* Add a randomization */
10371 					bbr_randomize_extra_state_time(bbr);
10372 				}
10373 			}
10374 		}
10375 		bbr->r_ctl.rc_bbr_state_atflight = max(1, cts);
10376 		bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[bbr_state_val(bbr)];
10377 	}
10378 	if (bbr->rc_use_google) {
10379 		bbr->r_ctl.rc_bbr_state_atflight = max(1, cts);
10380 	}
10381 	bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
10382 	bbr->r_ctl.rc_bbr_cwnd_gain = bbr_cwnd_gain;
10383 	if (dolog)
10384 		bbr_log_type_statechange(bbr, cts, line);
10385 
10386 	if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
10387 		uint32_t time_in;
10388 
10389 		time_in = cts - bbr->r_ctl.rc_bbr_state_time;
10390 		if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW) {
10391 			counter_u64_add(bbr_state_time[(old_state + 5)], time_in);
10392 		} else {
10393 			counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
10394 		}
10395 	}
10396 	bbr->r_ctl.bbr_smallest_srtt_this_state = 0xffffffff;
10397 	bbr_set_state_target(bbr, __LINE__);
10398 	if (bbr_sub_drain_slam_cwnd &&
10399 	    (bbr->rc_use_google == 0) &&
10400 	    (bbr_state_val(bbr) == BBR_SUB_DRAIN)) {
10401 		/* Slam down the cwnd */
10402 		bbr->r_ctl.rc_saved_cwnd = bbr->rc_tp->snd_cwnd;
10403 		bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
10404 		if (bbr_sub_drain_app_limit) {
10405 			/* Go app limited if we are on a long drain */
10406 			bbr->r_ctl.r_app_limited_until = (bbr->r_ctl.rc_delivered +
10407 							  ctf_flight_size(bbr->rc_tp,
10408 							      (bbr->r_ctl.rc_sacked +
10409 							       bbr->r_ctl.rc_lost_bytes)));
10410 		}
10411 		bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10412 	}
10413 	if (bbr->rc_lt_use_bw) {
10414 		/* In policed mode we clamp pacing_gain to BBR_UNIT */
10415 		bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
10416 	}
10417 	/* Google changes TSO size every cycle */
10418 	if (bbr->rc_use_google)
10419 		tcp_bbr_tso_size_check(bbr, cts);
10420 	bbr->r_ctl.gain_epoch = cts;
10421 	bbr->r_ctl.rc_bbr_state_time = cts;
10422 	bbr->r_ctl.substate_pe = bbr->r_ctl.rc_pkt_epoch;
10423 }
10424 
10425 static void
10426 bbr_set_probebw_google_gains(struct tcp_bbr *bbr, uint32_t cts, uint32_t losses)
10427 {
10428 	if ((bbr_state_val(bbr) == BBR_SUB_DRAIN) &&
10429 	    (google_allow_early_out == 1) &&
10430 	    (bbr->r_ctl.rc_flight_at_input <= bbr->r_ctl.rc_target_at_state)) {
10431 		/* We have reached out target flight size possibly early */
10432 		goto change_state;
10433 	}
10434 	if (TSTMP_LT(cts, bbr->r_ctl.rc_bbr_state_time)) {
10435 		return;
10436 	}
10437 	if ((cts - bbr->r_ctl.rc_bbr_state_time) < bbr_get_rtt(bbr, BBR_RTT_PROP)) {
10438 		/*
10439 		 * Must be a rttProp movement forward before
10440 		 * we can change states.
10441 		 */
10442 		return;
10443 	}
10444 	if (bbr_state_val(bbr) == BBR_SUB_GAIN) {
10445 		/*
10446 		 * The needed time has passed but for
10447 		 * the gain cycle extra rules apply:
10448 		 * 1) If we have seen loss, we exit
10449 		 * 2) If we have not reached the target
10450 		 *    we stay in GAIN (gain-to-target).
10451 		 */
10452 		if (google_consider_lost && losses)
10453 			goto change_state;
10454 		if (bbr->r_ctl.rc_target_at_state > bbr->r_ctl.rc_flight_at_input) {
10455 			return;
10456 		}
10457 	}
10458 change_state:
10459 	/* For gain we must reach our target, all others last 1 rttProp */
10460 	bbr_substate_change(bbr, cts, __LINE__, 1);
10461 }
10462 
10463 static void
10464 bbr_set_probebw_gains(struct tcp_bbr *bbr, uint32_t cts, uint32_t losses)
10465 {
10466 	uint32_t flight, bbr_cur_cycle_time;
10467 
10468 	if (bbr->rc_use_google) {
10469 		bbr_set_probebw_google_gains(bbr, cts, losses);
10470 		return;
10471 	}
10472 	if (cts == 0) {
10473 		/*
10474 		 * Never alow cts to be 0 we
10475 		 * do this so we can judge if
10476 		 * we have set a timestamp.
10477 		 */
10478 		cts = 1;
10479 	}
10480 	if (bbr_state_is_pkt_epoch)
10481 		bbr_cur_cycle_time = bbr_get_rtt(bbr, BBR_RTT_PKTRTT);
10482 	else
10483 		bbr_cur_cycle_time = bbr_get_rtt(bbr, BBR_RTT_PROP);
10484 
10485 	if (bbr->r_ctl.rc_bbr_state_atflight == 0) {
10486 		if (bbr_state_val(bbr) == BBR_SUB_DRAIN) {
10487 			flight = ctf_flight_size(bbr->rc_tp,
10488 				     (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
10489 			if (bbr_sub_drain_slam_cwnd && bbr->rc_hit_state_1) {
10490 				/* Keep it slam down */
10491 				if (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state) {
10492 					bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
10493 					bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10494 				}
10495 				if (bbr_sub_drain_app_limit) {
10496 					/* Go app limited if we are on a long drain */
10497 					bbr->r_ctl.r_app_limited_until = (bbr->r_ctl.rc_delivered + flight);
10498 				}
10499 			}
10500 			if (TSTMP_GT(cts, bbr->r_ctl.gain_epoch) &&
10501 			    (((cts - bbr->r_ctl.gain_epoch) > bbr_get_rtt(bbr, BBR_RTT_PROP)) ||
10502 			     (flight >= bbr->r_ctl.flightsize_at_drain))) {
10503 				/*
10504 				 * Still here after the same time as
10505 				 * the gain. We need to drain harder
10506 				 * for the next srtt. Reduce by a set amount
10507 				 * the gain drop is capped at DRAIN states
10508 				 * value (88).
10509 				 */
10510 				bbr->r_ctl.flightsize_at_drain = flight;
10511 				if (bbr_drain_drop_mul &&
10512 				    bbr_drain_drop_div &&
10513 				    (bbr_drain_drop_mul < bbr_drain_drop_div)) {
10514 					/* Use your specific drop value (def 4/5 = 20%) */
10515 					bbr->r_ctl.rc_bbr_hptsi_gain *= bbr_drain_drop_mul;
10516 					bbr->r_ctl.rc_bbr_hptsi_gain /= bbr_drain_drop_div;
10517 				} else {
10518 					/* You get drop of 20% */
10519 					bbr->r_ctl.rc_bbr_hptsi_gain *= 4;
10520 					bbr->r_ctl.rc_bbr_hptsi_gain /= 5;
10521 				}
10522 				if (bbr->r_ctl.rc_bbr_hptsi_gain <= bbr_drain_floor) {
10523 					/* Reduce our gain again to the bottom  */
10524 					bbr->r_ctl.rc_bbr_hptsi_gain = max(bbr_drain_floor, 1);
10525 				}
10526 				bbr_log_exit_gain(bbr, cts, 4);
10527 				/*
10528 				 * Extend out so we wait another
10529 				 * epoch before dropping again.
10530 				 */
10531 				bbr->r_ctl.gain_epoch = cts;
10532 			}
10533 			if (flight <= bbr->r_ctl.rc_target_at_state) {
10534 				if (bbr_sub_drain_slam_cwnd &&
10535 				    (bbr->rc_use_google == 0) &&
10536 				    (bbr->rc_tp->snd_cwnd < bbr->r_ctl.rc_saved_cwnd)) {
10537 					bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_saved_cwnd;
10538 					bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10539 				}
10540 				bbr->r_ctl.rc_bbr_state_atflight = max(cts, 1);
10541 				bbr_log_exit_gain(bbr, cts, 3);
10542 			}
10543 		} else {
10544 			/* Its a gain  */
10545 			if (bbr->r_ctl.rc_lost > bbr->r_ctl.bbr_lost_at_state) {
10546 				bbr->r_ctl.rc_bbr_state_atflight = max(cts, 1);
10547 				goto change_state;
10548 			}
10549 			if ((ctf_outstanding(bbr->rc_tp) >= bbr->r_ctl.rc_target_at_state) ||
10550 			    ((ctf_outstanding(bbr->rc_tp) +  bbr->rc_tp->t_maxseg - 1) >=
10551 			     bbr->rc_tp->snd_wnd)) {
10552 				bbr->r_ctl.rc_bbr_state_atflight = max(cts, 1);
10553 				bbr_log_exit_gain(bbr, cts, 2);
10554 			}
10555 		}
10556 		/**
10557 		 * We fall through and return always one of two things has
10558 		 * occurred.
10559 		 * 1) We are still not at target
10560 		 *    <or>
10561 		 * 2) We reached the target and set rc_bbr_state_atflight
10562 		 *    which means we no longer hit this block
10563 		 *    next time we are called.
10564 		 */
10565 		return;
10566 	}
10567 change_state:
10568 	if (TSTMP_LT(cts, bbr->r_ctl.rc_bbr_state_time))
10569 		return;
10570 	if ((cts - bbr->r_ctl.rc_bbr_state_time) < bbr_cur_cycle_time) {
10571 		/* Less than a full time-period has passed */
10572 		return;
10573 	}
10574 	if (bbr->r_ctl.rc_level_state_extra &&
10575 	    (bbr_state_val(bbr) > BBR_SUB_DRAIN) &&
10576 	    ((cts - bbr->r_ctl.rc_bbr_state_time) <
10577 	     (bbr_cur_cycle_time + bbr->r_ctl.rc_level_state_extra))) {
10578 		/* Less than a full time-period + extra has passed */
10579 		return;
10580 	}
10581 	if (bbr_gain_gets_extra_too &&
10582 	    bbr->r_ctl.rc_level_state_extra &&
10583 	    (bbr_state_val(bbr) == BBR_SUB_GAIN) &&
10584 	    ((cts - bbr->r_ctl.rc_bbr_state_time) <
10585 	     (bbr_cur_cycle_time + bbr->r_ctl.rc_level_state_extra))) {
10586 		/* Less than a full time-period + extra has passed */
10587 		return;
10588 	}
10589 	bbr_substate_change(bbr, cts, __LINE__, 1);
10590 }
10591 
10592 static uint32_t
10593 bbr_get_a_state_target(struct tcp_bbr *bbr, uint32_t gain)
10594 {
10595 	uint32_t mss, tar;
10596 
10597 	if (bbr->rc_use_google) {
10598 		/* Google just uses the cwnd target */
10599 		tar = bbr_get_target_cwnd(bbr, bbr_get_bw(bbr), gain);
10600 	} else {
10601 		mss = min((bbr->rc_tp->t_maxseg - bbr->rc_last_options),
10602 			  bbr->r_ctl.rc_pace_max_segs);
10603 		/* Get the base cwnd with gain rounded to a mss */
10604 		tar = roundup(bbr_get_raw_target_cwnd(bbr, bbr_get_bw(bbr),
10605 						      gain), mss);
10606 		/* Make sure it is within our min */
10607 		if (tar < get_min_cwnd(bbr))
10608 			return (get_min_cwnd(bbr));
10609 	}
10610 	return (tar);
10611 }
10612 
10613 static void
10614 bbr_set_state_target(struct tcp_bbr *bbr, int line)
10615 {
10616 	uint32_t tar, meth;
10617 
10618 	if ((bbr->rc_bbr_state == BBR_STATE_PROBE_RTT) &&
10619 	    ((bbr->r_ctl.bbr_rttprobe_gain_val == 0) || bbr->rc_use_google)) {
10620 		/* Special case using old probe-rtt method */
10621 		tar = bbr_rtt_probe_cwndtarg * (bbr->rc_tp->t_maxseg - bbr->rc_last_options);
10622 		meth = 1;
10623 	} else {
10624 		/* Non-probe-rtt case and reduced probe-rtt  */
10625 		if ((bbr->rc_bbr_state == BBR_STATE_PROBE_BW) &&
10626 		    (bbr->r_ctl.rc_bbr_hptsi_gain > BBR_UNIT)) {
10627 			/* For gain cycle we use the hptsi gain */
10628 			tar = bbr_get_a_state_target(bbr, bbr->r_ctl.rc_bbr_hptsi_gain);
10629 			meth = 2;
10630 		} else if ((bbr_target_is_bbunit) || bbr->rc_use_google) {
10631 			/*
10632 			 * If configured, or for google all other states
10633 			 * get BBR_UNIT.
10634 			 */
10635 			tar = bbr_get_a_state_target(bbr, BBR_UNIT);
10636 			meth = 3;
10637 		} else {
10638 			/*
10639 			 * Or we set a target based on the pacing gain
10640 			 * for non-google mode and default (non-configured).
10641 			 * Note we don't set a target goal below drain (192).
10642 			 */
10643 			if (bbr->r_ctl.rc_bbr_hptsi_gain < bbr_hptsi_gain[BBR_SUB_DRAIN])  {
10644 				tar = bbr_get_a_state_target(bbr, bbr_hptsi_gain[BBR_SUB_DRAIN]);
10645 				meth = 4;
10646 			} else {
10647 				tar = bbr_get_a_state_target(bbr, bbr->r_ctl.rc_bbr_hptsi_gain);
10648 				meth = 5;
10649 			}
10650 		}
10651 	}
10652 	bbr_log_set_of_state_target(bbr, tar, line, meth);
10653 	bbr->r_ctl.rc_target_at_state = tar;
10654 }
10655 
10656 static void
10657 bbr_enter_probe_rtt(struct tcp_bbr *bbr, uint32_t cts, int32_t line)
10658 {
10659 	/* Change to probe_rtt */
10660 	uint32_t time_in;
10661 
10662 	bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
10663 	bbr->r_ctl.flightsize_at_drain = ctf_flight_size(bbr->rc_tp,
10664 					     (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
10665 	bbr->r_ctl.r_app_limited_until = (bbr->r_ctl.flightsize_at_drain
10666 					  + bbr->r_ctl.rc_delivered);
10667 	/* Setup so we force feed the filter */
10668 	if (bbr->rc_use_google || bbr_probertt_sets_rtt)
10669 		bbr->rc_prtt_set_ts = 1;
10670 	if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
10671 		time_in = cts - bbr->r_ctl.rc_bbr_state_time;
10672 		counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
10673 	}
10674 	bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_ENTERPROBE, 0);
10675 	bbr->r_ctl.rc_rtt_shrinks = cts;
10676 	bbr->r_ctl.last_in_probertt = cts;
10677 	bbr->r_ctl.rc_probertt_srttchktim = cts;
10678 	bbr->r_ctl.rc_bbr_state_time = cts;
10679 	bbr->rc_bbr_state = BBR_STATE_PROBE_RTT;
10680 	/* We need to force the filter to update */
10681 
10682 	if ((bbr_sub_drain_slam_cwnd) &&
10683 	    bbr->rc_hit_state_1 &&
10684 	    (bbr->rc_use_google == 0) &&
10685 	    (bbr_state_val(bbr) == BBR_SUB_DRAIN)) {
10686 		if (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_saved_cwnd)
10687 			bbr->r_ctl.rc_saved_cwnd = bbr->rc_tp->snd_cwnd;
10688 	} else
10689 		bbr->r_ctl.rc_saved_cwnd = bbr->rc_tp->snd_cwnd;
10690 	/* Update the lost */
10691 	bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
10692 	if ((bbr->r_ctl.bbr_rttprobe_gain_val == 0) || bbr->rc_use_google){
10693 		/* Set to the non-configurable default of 4 (PROBE_RTT_MIN)  */
10694 		bbr->rc_tp->snd_cwnd = bbr_rtt_probe_cwndtarg * (bbr->rc_tp->t_maxseg - bbr->rc_last_options);
10695 		bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10696 		bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
10697 		bbr->r_ctl.rc_bbr_cwnd_gain = BBR_UNIT;
10698 		bbr_log_set_of_state_target(bbr, bbr->rc_tp->snd_cwnd, __LINE__, 6);
10699 		bbr->r_ctl.rc_target_at_state = bbr->rc_tp->snd_cwnd;
10700 	} else {
10701 		/*
10702 		 * We bring it down slowly by using a hptsi gain that is
10703 		 * probably 75%. This will slowly float down our outstanding
10704 		 * without tampering with the cwnd.
10705 		 */
10706 		bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.bbr_rttprobe_gain_val;
10707 		bbr->r_ctl.rc_bbr_cwnd_gain = BBR_UNIT;
10708 		bbr_set_state_target(bbr, __LINE__);
10709 		if (bbr_prtt_slam_cwnd &&
10710 		    (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state)) {
10711 			bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
10712 			bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10713 		}
10714 	}
10715 	if (ctf_flight_size(bbr->rc_tp,
10716 		(bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) <=
10717 	    bbr->r_ctl.rc_target_at_state) {
10718 		/* We are at target */
10719 		bbr->r_ctl.rc_bbr_enters_probertt = cts;
10720 	} else {
10721 		/* We need to come down to reach target before our time begins */
10722 		bbr->r_ctl.rc_bbr_enters_probertt = 0;
10723 	}
10724 	bbr->r_ctl.rc_pe_of_prtt = bbr->r_ctl.rc_pkt_epoch;
10725 	BBR_STAT_INC(bbr_enter_probertt);
10726 	bbr_log_exit_gain(bbr, cts, 0);
10727 	bbr_log_type_statechange(bbr, cts, line);
10728 }
10729 
10730 static void
10731 bbr_check_probe_rtt_limits(struct tcp_bbr *bbr, uint32_t cts)
10732 {
10733 	/*
10734 	 * Sanity check on probe-rtt intervals.
10735 	 * In crazy situations where we are competing
10736 	 * against new-reno flows with huge buffers
10737 	 * our rtt-prop interval could come to dominate
10738 	 * things if we can't get through a full set
10739 	 * of cycles, we need to adjust it.
10740 	 */
10741 	if (bbr_can_adjust_probertt &&
10742 	    (bbr->rc_use_google == 0)) {
10743 		uint16_t val = 0;
10744 		uint32_t cur_rttp, fval, newval, baseval;
10745 
10746 		/* Are we to small and go into probe-rtt to often? */
10747 		baseval = (bbr_get_rtt(bbr, BBR_RTT_PROP) * (BBR_SUBSTATE_COUNT + 1));
10748 		cur_rttp = roundup(baseval, USECS_IN_SECOND);
10749 		fval = bbr_filter_len_sec * USECS_IN_SECOND;
10750 		if (bbr_is_ratio == 0) {
10751 			if (fval > bbr_rtt_probe_limit)
10752 				newval = cur_rttp + (fval - bbr_rtt_probe_limit);
10753 			else
10754 				newval = cur_rttp;
10755 		} else {
10756 			int mul;
10757 
10758 			mul = fval / bbr_rtt_probe_limit;
10759 			newval = cur_rttp * mul;
10760 		}
10761 		if (cur_rttp > 	bbr->r_ctl.rc_probertt_int) {
10762 			bbr->r_ctl.rc_probertt_int = cur_rttp;
10763 			reset_time_small(&bbr->r_ctl.rc_rttprop, newval);
10764 			val = 1;
10765 		} else {
10766 			/*
10767 			 * No adjustments were made
10768 			 * do we need to shrink it?
10769 			 */
10770 			if (bbr->r_ctl.rc_probertt_int > bbr_rtt_probe_limit) {
10771 				if (cur_rttp <= bbr_rtt_probe_limit) {
10772 					/*
10773 					 * Things have calmed down lets
10774 					 * shrink all the way to default
10775 					 */
10776 					bbr->r_ctl.rc_probertt_int = bbr_rtt_probe_limit;
10777 					reset_time_small(&bbr->r_ctl.rc_rttprop,
10778 							 (bbr_filter_len_sec * USECS_IN_SECOND));
10779 					cur_rttp = bbr_rtt_probe_limit;
10780 					newval = (bbr_filter_len_sec * USECS_IN_SECOND);
10781 					val = 2;
10782 				} else {
10783 					/*
10784 					 * Well does some adjustment make sense?
10785 					 */
10786 					if (cur_rttp < bbr->r_ctl.rc_probertt_int) {
10787 						/* We can reduce interval time some */
10788 						bbr->r_ctl.rc_probertt_int = cur_rttp;
10789 						reset_time_small(&bbr->r_ctl.rc_rttprop, newval);
10790 						val = 3;
10791 					}
10792 				}
10793 			}
10794 		}
10795 		if (val)
10796 			bbr_log_rtt_shrinks(bbr, cts, cur_rttp, newval, __LINE__, BBR_RTTS_RESETS_VALUES, val);
10797 	}
10798 }
10799 
10800 static void
10801 bbr_exit_probe_rtt(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
10802 {
10803 	/* Exit probe-rtt */
10804 
10805 	if (tp->snd_cwnd < bbr->r_ctl.rc_saved_cwnd) {
10806 		tp->snd_cwnd = bbr->r_ctl.rc_saved_cwnd;
10807 		bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10808 	}
10809 	bbr_log_exit_gain(bbr, cts, 1);
10810 	bbr->rc_hit_state_1 = 0;
10811 	bbr->r_ctl.rc_rtt_shrinks = cts;
10812 	bbr->r_ctl.last_in_probertt = cts;
10813 	bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_RTTPROBE, 0);
10814 	bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
10815 	bbr->r_ctl.r_app_limited_until = (ctf_flight_size(tp,
10816 					      (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) +
10817 					  bbr->r_ctl.rc_delivered);
10818 	if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
10819 		uint32_t time_in;
10820 
10821 		time_in = cts - bbr->r_ctl.rc_bbr_state_time;
10822 		counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
10823 	}
10824 	if (bbr->rc_filled_pipe) {
10825 		/* Switch to probe_bw */
10826 		bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
10827 		bbr->rc_bbr_substate = bbr_pick_probebw_substate(bbr, cts);
10828 		bbr->r_ctl.rc_bbr_cwnd_gain = bbr_cwnd_gain;
10829 		bbr_substate_change(bbr, cts, __LINE__, 0);
10830 		bbr_log_type_statechange(bbr, cts, __LINE__);
10831 	} else {
10832 		/* Back to startup */
10833 		bbr->rc_bbr_state = BBR_STATE_STARTUP;
10834 		bbr->r_ctl.rc_bbr_state_time = cts;
10835 		/*
10836 		 * We don't want to give a complete free 3
10837 		 * measurements until we exit, so we use
10838 		 * the number of pe's we were in probe-rtt
10839 		 * to add to the startup_epoch. That way
10840 		 * we will still retain the old state.
10841 		 */
10842 		bbr->r_ctl.rc_bbr_last_startup_epoch += (bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_pe_of_prtt);
10843 		bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
10844 		/* Make sure to use the lower pg when shifting back in */
10845 		if (bbr->r_ctl.rc_lost &&
10846 		    bbr_use_lower_gain_in_startup &&
10847 		    (bbr->rc_use_google == 0))
10848 			bbr->r_ctl.rc_bbr_hptsi_gain = bbr_startup_lower;
10849 		else
10850 			bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.rc_startup_pg;
10851 		bbr->r_ctl.rc_bbr_cwnd_gain = bbr->r_ctl.rc_startup_pg;
10852 		/* Probably not needed but set it anyway */
10853 		bbr_set_state_target(bbr, __LINE__);
10854 		bbr_log_type_statechange(bbr, cts, __LINE__);
10855 		bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
10856 		    bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 0);
10857 	}
10858 	bbr_check_probe_rtt_limits(bbr, cts);
10859 }
10860 
10861 static int32_t inline
10862 bbr_should_enter_probe_rtt(struct tcp_bbr *bbr, uint32_t cts)
10863 {
10864 	if ((bbr->rc_past_init_win == 1) &&
10865 	    (bbr->rc_in_persist == 0) &&
10866 	    (bbr_calc_time(cts, bbr->r_ctl.rc_rtt_shrinks) >= bbr->r_ctl.rc_probertt_int)) {
10867 		return (1);
10868 	}
10869 	if (bbr_can_force_probertt &&
10870 	    (bbr->rc_in_persist == 0) &&
10871 	    (TSTMP_GT(cts, bbr->r_ctl.last_in_probertt)) &&
10872 	    ((cts - bbr->r_ctl.last_in_probertt) > bbr->r_ctl.rc_probertt_int)) {
10873 		return (1);
10874 	}
10875 	return (0);
10876 }
10877 
10878 static int32_t
10879 bbr_google_startup(struct tcp_bbr *bbr, uint32_t cts, int32_t  pkt_epoch)
10880 {
10881 	uint64_t btlbw, gain;
10882 	if (pkt_epoch == 0) {
10883 		/*
10884 		 * Need to be on a pkt-epoch to continue.
10885 		 */
10886 		return (0);
10887 	}
10888 	btlbw = bbr_get_full_bw(bbr);
10889 	gain = ((bbr->r_ctl.rc_bbr_lastbtlbw *
10890 		 (uint64_t)bbr_start_exit) / (uint64_t)100) + bbr->r_ctl.rc_bbr_lastbtlbw;
10891 	if (btlbw >= gain) {
10892 		bbr->r_ctl.rc_bbr_last_startup_epoch = bbr->r_ctl.rc_pkt_epoch;
10893 		bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
10894 				      bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 3);
10895 		bbr->r_ctl.rc_bbr_lastbtlbw = btlbw;
10896 	}
10897 	if ((bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_bbr_last_startup_epoch) >= BBR_STARTUP_EPOCHS)
10898 		return (1);
10899 	bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
10900 			      bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 8);
10901 	return(0);
10902 }
10903 
10904 static int32_t inline
10905 bbr_state_startup(struct tcp_bbr *bbr, uint32_t cts, int32_t epoch, int32_t pkt_epoch)
10906 {
10907 	/* Have we gained 25% in the last 3 packet based epoch's? */
10908 	uint64_t btlbw, gain;
10909 	int do_exit;
10910 	int delta, rtt_gain;
10911 
10912 	if ((bbr->rc_tp->snd_una == bbr->rc_tp->snd_max) &&
10913 	    (bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time) >= bbr_rtt_probe_time)) {
10914 		/*
10915 		 * This qualifies as a RTT_PROBE session since we drop the
10916 		 * data outstanding to nothing and waited more than
10917 		 * bbr_rtt_probe_time.
10918 		 */
10919 		bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_WASIDLE, 0);
10920 		bbr_set_reduced_rtt(bbr, cts, __LINE__);
10921 	}
10922 	if (bbr_should_enter_probe_rtt(bbr, cts)) {
10923 		bbr_enter_probe_rtt(bbr, cts, __LINE__);
10924 		return (0);
10925 	}
10926 	if (bbr->rc_use_google)
10927 		return (bbr_google_startup(bbr, cts,  pkt_epoch));
10928 
10929 	if ((bbr->r_ctl.rc_lost > bbr->r_ctl.rc_lost_at_startup) &&
10930 	    (bbr_use_lower_gain_in_startup)) {
10931 		/* Drop to a lower gain 1.5 x since we saw loss */
10932 		bbr->r_ctl.rc_bbr_hptsi_gain = bbr_startup_lower;
10933 	}
10934 	if (pkt_epoch == 0) {
10935 		/*
10936 		 * Need to be on a pkt-epoch to continue.
10937 		 */
10938 		return (0);
10939 	}
10940 	if (bbr_rtt_gain_thresh) {
10941 		/*
10942 		 * Do we allow a flow to stay
10943 		 * in startup with no loss and no
10944 		 * gain in rtt over a set threshold?
10945 		 */
10946 		if (bbr->r_ctl.rc_pkt_epoch_rtt &&
10947 		    bbr->r_ctl.startup_last_srtt &&
10948 		    (bbr->r_ctl.rc_pkt_epoch_rtt > bbr->r_ctl.startup_last_srtt)) {
10949 			delta = bbr->r_ctl.rc_pkt_epoch_rtt - bbr->r_ctl.startup_last_srtt;
10950 			rtt_gain = (delta * 100) / bbr->r_ctl.startup_last_srtt;
10951 		} else
10952 			rtt_gain = 0;
10953 		if ((bbr->r_ctl.startup_last_srtt == 0)  ||
10954 		    (bbr->r_ctl.rc_pkt_epoch_rtt < bbr->r_ctl.startup_last_srtt))
10955 			/* First time or new lower value */
10956 			bbr->r_ctl.startup_last_srtt = bbr->r_ctl.rc_pkt_epoch_rtt;
10957 
10958 		if ((bbr->r_ctl.rc_lost == 0) &&
10959 		    (rtt_gain < bbr_rtt_gain_thresh)) {
10960 			/*
10961 			 * No loss, and we are under
10962 			 * our gain threhold for
10963 			 * increasing RTT.
10964 			 */
10965 			if (bbr->r_ctl.rc_bbr_last_startup_epoch < bbr->r_ctl.rc_pkt_epoch)
10966 				bbr->r_ctl.rc_bbr_last_startup_epoch++;
10967 			bbr_log_startup_event(bbr, cts, rtt_gain,
10968 					      delta, bbr->r_ctl.startup_last_srtt, 10);
10969 			return (0);
10970 		}
10971 	}
10972 	if ((bbr->r_ctl.r_measurement_count == bbr->r_ctl.last_startup_measure) &&
10973 	    (bbr->r_ctl.rc_lost_at_startup == bbr->r_ctl.rc_lost) &&
10974 	    (!IN_RECOVERY(bbr->rc_tp->t_flags))) {
10975 		/*
10976 		 * We only assess if we have a new measurement when
10977 		 * we have no loss and are not in recovery.
10978 		 * Drag up by one our last_startup epoch so we will hold
10979 		 * the number of non-gain we have already accumulated.
10980 		 */
10981 		if (bbr->r_ctl.rc_bbr_last_startup_epoch < bbr->r_ctl.rc_pkt_epoch)
10982 			bbr->r_ctl.rc_bbr_last_startup_epoch++;
10983 		bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
10984 				      bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 9);
10985 		return (0);
10986 	}
10987 	/* Case where we reduced the lost (bad retransmit) */
10988 	if (bbr->r_ctl.rc_lost_at_startup > bbr->r_ctl.rc_lost)
10989 		bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
10990 	bbr->r_ctl.last_startup_measure = bbr->r_ctl.r_measurement_count;
10991 	btlbw = bbr_get_full_bw(bbr);
10992 	if (bbr->r_ctl.rc_bbr_hptsi_gain == bbr_startup_lower)
10993 		gain = ((bbr->r_ctl.rc_bbr_lastbtlbw *
10994 			 (uint64_t)bbr_low_start_exit) / (uint64_t)100) + bbr->r_ctl.rc_bbr_lastbtlbw;
10995 	else
10996 		gain = ((bbr->r_ctl.rc_bbr_lastbtlbw *
10997 			 (uint64_t)bbr_start_exit) / (uint64_t)100) + bbr->r_ctl.rc_bbr_lastbtlbw;
10998 	do_exit = 0;
10999 	if (btlbw > bbr->r_ctl.rc_bbr_lastbtlbw)
11000 		bbr->r_ctl.rc_bbr_lastbtlbw = btlbw;
11001 	if (btlbw >= gain) {
11002 		bbr->r_ctl.rc_bbr_last_startup_epoch = bbr->r_ctl.rc_pkt_epoch;
11003 		/* Update the lost so we won't exit in next set of tests */
11004 		bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
11005 		bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
11006 				      bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 3);
11007 	}
11008 	if ((bbr->rc_loss_exit &&
11009 	     (bbr->r_ctl.rc_lost > bbr->r_ctl.rc_lost_at_startup) &&
11010 	     (bbr->r_ctl.rc_pkt_epoch_loss_rate > bbr_startup_loss_thresh)) &&
11011 	    ((bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_bbr_last_startup_epoch) >= BBR_STARTUP_EPOCHS)) {
11012 		/*
11013 		 * If we had no gain,  we had loss and that loss was above
11014 		 * our threshould, the rwnd is not constrained, and we have
11015 		 * had at least 3 packet epochs exit. Note that this is
11016 		 * switched off by sysctl. Google does not do this by the
11017 		 * way.
11018 		 */
11019 		if ((ctf_flight_size(bbr->rc_tp,
11020 			 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) +
11021 		     (2 * max(bbr->r_ctl.rc_pace_max_segs, bbr->rc_tp->t_maxseg))) <= bbr->rc_tp->snd_wnd) {
11022 			do_exit = 1;
11023 			bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
11024 					      bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 4);
11025 		} else {
11026 			/* Just record an updated loss value */
11027 			bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
11028 			bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
11029 					      bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 5);
11030 		}
11031 	} else
11032 		bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
11033 	if (((bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_bbr_last_startup_epoch) >= BBR_STARTUP_EPOCHS) ||
11034 	    do_exit) {
11035 		/* Return 1 to exit the startup state. */
11036 		return (1);
11037 	}
11038 	/* Stay in startup */
11039 	bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
11040 			      bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 8);
11041 	return (0);
11042 }
11043 
11044 static void
11045 bbr_state_change(struct tcp_bbr *bbr, uint32_t cts, int32_t epoch, int32_t pkt_epoch, uint32_t losses)
11046 {
11047 	/*
11048 	 * A tick occurred in the rtt epoch do we need to do anything?
11049 	 */
11050 #ifdef BBR_INVARIANTS
11051 	if ((bbr->rc_bbr_state != BBR_STATE_STARTUP) &&
11052 	    (bbr->rc_bbr_state != BBR_STATE_DRAIN) &&
11053 	    (bbr->rc_bbr_state != BBR_STATE_PROBE_RTT) &&
11054 	    (bbr->rc_bbr_state != BBR_STATE_IDLE_EXIT) &&
11055 	    (bbr->rc_bbr_state != BBR_STATE_PROBE_BW)) {
11056 		/* Debug code? */
11057 		panic("Unknown BBR state %d?\n", bbr->rc_bbr_state);
11058 	}
11059 #endif
11060 	if (bbr->rc_bbr_state == BBR_STATE_STARTUP) {
11061 		/* Do we exit the startup state? */
11062 		if (bbr_state_startup(bbr, cts, epoch, pkt_epoch)) {
11063 			uint32_t time_in;
11064 
11065 			bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
11066 					      bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 6);
11067 			bbr->rc_filled_pipe = 1;
11068 			bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
11069 			if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
11070 				time_in = cts - bbr->r_ctl.rc_bbr_state_time;
11071 				counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
11072 			} else
11073 				time_in = 0;
11074 			if (bbr->rc_no_pacing)
11075 				bbr->rc_no_pacing = 0;
11076 			bbr->r_ctl.rc_bbr_state_time = cts;
11077 			bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.rc_drain_pg;
11078 			bbr->rc_bbr_state = BBR_STATE_DRAIN;
11079 			bbr_set_state_target(bbr, __LINE__);
11080 			if ((bbr->rc_use_google == 0) &&
11081 			    bbr_slam_cwnd_in_main_drain) {
11082 				/* Here we don't have to worry about probe-rtt */
11083 				bbr->r_ctl.rc_saved_cwnd = bbr->rc_tp->snd_cwnd;
11084 				bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
11085 				bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
11086 			}
11087 			bbr->r_ctl.rc_bbr_cwnd_gain = bbr_high_gain;
11088 			bbr_log_type_statechange(bbr, cts, __LINE__);
11089 			if (ctf_flight_size(bbr->rc_tp,
11090 			        (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) <=
11091 			    bbr->r_ctl.rc_target_at_state) {
11092 				/*
11093 				 * Switch to probe_bw if we are already
11094 				 * there
11095 				 */
11096 				bbr->rc_bbr_substate = bbr_pick_probebw_substate(bbr, cts);
11097 				bbr_substate_change(bbr, cts, __LINE__, 0);
11098 				bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
11099 				bbr_log_type_statechange(bbr, cts, __LINE__);
11100 			}
11101 		}
11102 	} else if (bbr->rc_bbr_state == BBR_STATE_IDLE_EXIT) {
11103 		uint32_t inflight;
11104 		struct tcpcb *tp;
11105 
11106 		tp = bbr->rc_tp;
11107 		inflight = ctf_flight_size(tp,
11108 			      (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
11109 		if (inflight >= bbr->r_ctl.rc_target_at_state) {
11110 			/* We have reached a flight of the cwnd target */
11111 			bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
11112 			bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
11113 			bbr->r_ctl.rc_bbr_cwnd_gain = BBR_UNIT;
11114 			bbr_set_state_target(bbr, __LINE__);
11115 			/*
11116 			 * Rig it so we don't do anything crazy and
11117 			 * start fresh with a new randomization.
11118 			 */
11119 			bbr->r_ctl.bbr_smallest_srtt_this_state = 0xffffffff;
11120 			bbr->rc_bbr_substate = BBR_SUB_LEVEL6;
11121 			bbr_substate_change(bbr, cts, __LINE__, 1);
11122 		}
11123 	} else if (bbr->rc_bbr_state == BBR_STATE_DRAIN) {
11124 		/* Has in-flight reached the bdp (or less)? */
11125 		uint32_t inflight;
11126 		struct tcpcb *tp;
11127 
11128 		tp = bbr->rc_tp;
11129 		inflight = ctf_flight_size(tp,
11130 			      (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
11131 		if ((bbr->rc_use_google == 0) &&
11132 		    bbr_slam_cwnd_in_main_drain &&
11133 		    (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state)) {
11134 			/*
11135 			 * Here we don't have to worry about probe-rtt
11136 			 * re-slam it, but keep it slammed down.
11137 			 */
11138 			bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
11139 			bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
11140 		}
11141 		if (inflight <= bbr->r_ctl.rc_target_at_state) {
11142 			/* We have drained */
11143 			bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
11144 			bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
11145 			if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
11146 				uint32_t time_in;
11147 
11148 				time_in = cts - bbr->r_ctl.rc_bbr_state_time;
11149 				counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
11150 			}
11151 			if ((bbr->rc_use_google == 0) &&
11152 			    bbr_slam_cwnd_in_main_drain &&
11153 			    (tp->snd_cwnd < bbr->r_ctl.rc_saved_cwnd)) {
11154 				/* Restore the cwnd */
11155 				tp->snd_cwnd = bbr->r_ctl.rc_saved_cwnd;
11156 				bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
11157 			}
11158 			/* Setup probe-rtt has being done now RRS-HERE */
11159 			bbr->r_ctl.rc_rtt_shrinks = cts;
11160 			bbr->r_ctl.last_in_probertt = cts;
11161 			bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_LEAVE_DRAIN, 0);
11162 			/* Randomly pick a sub-state */
11163 			bbr->rc_bbr_substate = bbr_pick_probebw_substate(bbr, cts);
11164 			bbr_substate_change(bbr, cts, __LINE__, 0);
11165 			bbr_log_type_statechange(bbr, cts, __LINE__);
11166 		}
11167 	} else if (bbr->rc_bbr_state == BBR_STATE_PROBE_RTT) {
11168 		uint32_t flight;
11169 
11170 		flight = ctf_flight_size(bbr->rc_tp,
11171 			     (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
11172 		bbr->r_ctl.r_app_limited_until = (flight + bbr->r_ctl.rc_delivered);
11173 		if (((bbr->r_ctl.bbr_rttprobe_gain_val == 0) || bbr->rc_use_google) &&
11174 		    (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state)) {
11175 			/*
11176 			 * We must keep cwnd at the desired MSS.
11177 			 */
11178 			bbr->rc_tp->snd_cwnd = bbr_rtt_probe_cwndtarg * (bbr->rc_tp->t_maxseg - bbr->rc_last_options);
11179 			bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
11180 		} else if ((bbr_prtt_slam_cwnd) &&
11181 			   (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state)) {
11182 			/* Re-slam it */
11183 			bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
11184 			bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
11185 		}
11186 		if (bbr->r_ctl.rc_bbr_enters_probertt == 0) {
11187 			/* Has outstanding reached our target? */
11188 			if (flight <= bbr->r_ctl.rc_target_at_state) {
11189 				bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_REACHTAR, 0);
11190 				bbr->r_ctl.rc_bbr_enters_probertt = cts;
11191 				/* If time is exactly 0, be 1usec off */
11192 				if (bbr->r_ctl.rc_bbr_enters_probertt == 0)
11193 					bbr->r_ctl.rc_bbr_enters_probertt = 1;
11194 				if (bbr->rc_use_google == 0) {
11195 					/*
11196 					 * Restore any lowering that as occurred to
11197 					 * reach here
11198 					 */
11199 					if (bbr->r_ctl.bbr_rttprobe_gain_val)
11200 						bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.bbr_rttprobe_gain_val;
11201 					else
11202 						bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
11203 				}
11204 			}
11205 			if ((bbr->r_ctl.rc_bbr_enters_probertt == 0) &&
11206 			    (bbr->rc_use_google == 0) &&
11207 			    bbr->r_ctl.bbr_rttprobe_gain_val &&
11208 			    (((cts - bbr->r_ctl.rc_probertt_srttchktim) > bbr_get_rtt(bbr, bbr_drain_rtt)) ||
11209 			     (flight >= bbr->r_ctl.flightsize_at_drain))) {
11210 				/*
11211 				 * We have doddled with our current hptsi
11212 				 * gain an srtt and have still not made it
11213 				 * to target, or we have increased our flight.
11214 				 * Lets reduce the gain by xx%
11215 				 * flooring the reduce at DRAIN (based on
11216 				 * mul/div)
11217 				 */
11218 				int red;
11219 
11220 				bbr->r_ctl.flightsize_at_drain = flight;
11221 				bbr->r_ctl.rc_probertt_srttchktim = cts;
11222 				red = max((bbr->r_ctl.bbr_rttprobe_gain_val / 10), 1);
11223 				if ((bbr->r_ctl.rc_bbr_hptsi_gain - red) > max(bbr_drain_floor, 1)) {
11224 					/* Reduce our gain again */
11225 					bbr->r_ctl.rc_bbr_hptsi_gain -= red;
11226 					bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_SHRINK_PG, 0);
11227 				} else if (bbr->r_ctl.rc_bbr_hptsi_gain > max(bbr_drain_floor, 1)) {
11228 					/* one more chance before we give up */
11229 					bbr->r_ctl.rc_bbr_hptsi_gain = max(bbr_drain_floor, 1);
11230 					bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_SHRINK_PG_FINAL, 0);
11231 				} else {
11232 					/* At the very bottom */
11233 					bbr->r_ctl.rc_bbr_hptsi_gain = max((bbr_drain_floor-1), 1);
11234 				}
11235 			}
11236 		}
11237 		if (bbr->r_ctl.rc_bbr_enters_probertt &&
11238 		    (TSTMP_GT(cts, bbr->r_ctl.rc_bbr_enters_probertt)) &&
11239 		    ((cts - bbr->r_ctl.rc_bbr_enters_probertt) >= bbr_rtt_probe_time)) {
11240 			/* Time to exit probe RTT normally */
11241 			bbr_exit_probe_rtt(bbr->rc_tp, bbr, cts);
11242 		}
11243 	} else if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW) {
11244 		if ((bbr->rc_tp->snd_una == bbr->rc_tp->snd_max) &&
11245 		    (bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time) >= bbr_rtt_probe_time)) {
11246 			/*
11247 			 * This qualifies as a RTT_PROBE session since we
11248 			 * drop the data outstanding to nothing and waited
11249 			 * more than bbr_rtt_probe_time.
11250 			 */
11251 			bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_WASIDLE, 0);
11252 			bbr_set_reduced_rtt(bbr, cts, __LINE__);
11253 		}
11254 		if (bbr_should_enter_probe_rtt(bbr, cts)) {
11255 			bbr_enter_probe_rtt(bbr, cts, __LINE__);
11256 		} else {
11257 			bbr_set_probebw_gains(bbr, cts, losses);
11258 		}
11259 	}
11260 }
11261 
11262 static void
11263 bbr_check_bbr_for_state(struct tcp_bbr *bbr, uint32_t cts, int32_t line, uint32_t losses)
11264 {
11265 	int32_t epoch = 0;
11266 
11267 	if ((cts - bbr->r_ctl.rc_rcv_epoch_start) >= bbr_get_rtt(bbr, BBR_RTT_PROP)) {
11268 		bbr_set_epoch(bbr, cts, line);
11269 		/* At each epoch doe lt bw sampling */
11270 		epoch = 1;
11271 	}
11272 	bbr_state_change(bbr, cts, epoch, bbr->rc_is_pkt_epoch_now, losses);
11273 }
11274 
11275 static int
11276 bbr_do_segment_nounlock(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
11277     int32_t drop_hdrlen, int32_t tlen, uint8_t iptos, int32_t nxt_pkt,
11278     struct timeval *tv)
11279 {
11280 	struct inpcb *inp = tptoinpcb(tp);
11281 	struct socket *so = tptosocket(tp);
11282 	int32_t thflags, retval;
11283 	uint32_t cts, lcts;
11284 	uint32_t tiwin;
11285 	struct tcpopt to;
11286 	struct tcp_bbr *bbr;
11287 	struct bbr_sendmap *rsm;
11288 	struct timeval ltv;
11289 	int32_t did_out = 0;
11290 	uint16_t nsegs;
11291 	int32_t prev_state;
11292 	uint32_t lost;
11293 
11294 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
11295 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
11296 	/* add in our stats */
11297 	kern_prefetch(bbr, &prev_state);
11298 	prev_state = 0;
11299 	thflags = tcp_get_flags(th);
11300 	/*
11301 	 * If this is either a state-changing packet or current state isn't
11302 	 * established, we require a write lock on tcbinfo.  Otherwise, we
11303 	 * allow the tcbinfo to be in either alocked or unlocked, as the
11304 	 * caller may have unnecessarily acquired a write lock due to a
11305 	 * race.
11306 	 */
11307 	INP_WLOCK_ASSERT(tptoinpcb(tp));
11308 	KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN",
11309 	    __func__));
11310 	KASSERT(tp->t_state != TCPS_TIME_WAIT, ("%s: TCPS_TIME_WAIT",
11311 	    __func__));
11312 
11313 	tp->t_rcvtime = ticks;
11314 	/*
11315 	 * Unscale the window into a 32-bit value. For the SYN_SENT state
11316 	 * the scale is zero.
11317 	 */
11318 	tiwin = th->th_win << tp->snd_scale;
11319 #ifdef STATS
11320 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_FRWIN, tiwin);
11321 #endif
11322 
11323 	if (m->m_flags & M_TSTMP) {
11324 		/* Prefer the hardware timestamp if present */
11325 		struct timespec ts;
11326 
11327 		mbuf_tstmp2timespec(m, &ts);
11328 		bbr->rc_tv.tv_sec = ts.tv_sec;
11329 		bbr->rc_tv.tv_usec = ts.tv_nsec / 1000;
11330 		bbr->r_ctl.rc_rcvtime = cts = tcp_tv_to_usectick(&bbr->rc_tv);
11331 	} else if (m->m_flags & M_TSTMP_LRO) {
11332 		/* Next the arrival timestamp */
11333 		struct timespec ts;
11334 
11335 		mbuf_tstmp2timespec(m, &ts);
11336 		bbr->rc_tv.tv_sec = ts.tv_sec;
11337 		bbr->rc_tv.tv_usec = ts.tv_nsec / 1000;
11338 		bbr->r_ctl.rc_rcvtime = cts = tcp_tv_to_usectick(&bbr->rc_tv);
11339 	} else {
11340 		/*
11341 		 * Ok just get the current time.
11342 		 */
11343 		bbr->r_ctl.rc_rcvtime = lcts = cts = tcp_get_usecs(&bbr->rc_tv);
11344 	}
11345 	/*
11346 	 * Parse options on any incoming segment.
11347 	 */
11348 	tcp_dooptions(&to, (u_char *)(th + 1),
11349 	    (th->th_off << 2) - sizeof(struct tcphdr),
11350 	    (thflags & TH_SYN) ? TO_SYN : 0);
11351 	if (tp->t_flags2 & TF2_PROC_SACK_PROHIBIT) {
11352 		/*
11353 		 * We don't look at sack's from the
11354 		 * peer because the MSS is too small which
11355 		 * can subject us to an attack.
11356 		 */
11357 		to.to_flags &= ~TOF_SACK;
11358 	}
11359 	/*
11360 	 * If timestamps were negotiated during SYN/ACK and a
11361 	 * segment without a timestamp is received, silently drop
11362 	 * the segment, unless it is a RST segment or missing timestamps are
11363 	 * tolerated.
11364 	 * See section 3.2 of RFC 7323.
11365 	 */
11366 	if ((tp->t_flags & TF_RCVD_TSTMP) && !(to.to_flags & TOF_TS) &&
11367 	    ((thflags & TH_RST) == 0) && (V_tcp_tolerate_missing_ts == 0)) {
11368 		retval = 0;
11369 		m_freem(m);
11370 		goto done_with_input;
11371 	}
11372 	/*
11373 	 * If echoed timestamp is later than the current time, fall back to
11374 	 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
11375 	 * were used when this connection was established.
11376 	 */
11377 	if ((to.to_flags & TOF_TS) && (to.to_tsecr != 0)) {
11378 		to.to_tsecr -= tp->ts_offset;
11379 		if (TSTMP_GT(to.to_tsecr, tcp_tv_to_mssectick(&bbr->rc_tv)))
11380 			to.to_tsecr = 0;
11381 	}
11382 	/*
11383 	 * If its the first time in we need to take care of options and
11384 	 * verify we can do SACK for rack!
11385 	 */
11386 	if (bbr->r_state == 0) {
11387 		/*
11388 		 * Process options only when we get SYN/ACK back. The SYN
11389 		 * case for incoming connections is handled in tcp_syncache.
11390 		 * According to RFC1323 the window field in a SYN (i.e., a
11391 		 * <SYN> or <SYN,ACK>) segment itself is never scaled. XXX
11392 		 * this is traditional behavior, may need to be cleaned up.
11393 		 */
11394 		if (bbr->rc_inp == NULL) {
11395 			bbr->rc_inp = inp;
11396 		}
11397 		/*
11398 		 * We need to init rc_inp here since its not init'd when
11399 		 * bbr_init is called
11400 		 */
11401 		if (tp->t_state == TCPS_SYN_SENT && (thflags & TH_SYN)) {
11402 			if ((to.to_flags & TOF_SCALE) &&
11403 			    (tp->t_flags & TF_REQ_SCALE)) {
11404 				tp->t_flags |= TF_RCVD_SCALE;
11405 				tp->snd_scale = to.to_wscale;
11406 			} else
11407 				tp->t_flags &= ~TF_REQ_SCALE;
11408 			/*
11409 			 * Initial send window.  It will be updated with the
11410 			 * next incoming segment to the scaled value.
11411 			 */
11412 			tp->snd_wnd = th->th_win;
11413 			if ((to.to_flags & TOF_TS) &&
11414 			    (tp->t_flags & TF_REQ_TSTMP)) {
11415 				tp->t_flags |= TF_RCVD_TSTMP;
11416 				tp->ts_recent = to.to_tsval;
11417 				tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
11418 			} else
11419 			    tp->t_flags &= ~TF_REQ_TSTMP;
11420 			if (to.to_flags & TOF_MSS)
11421 				tcp_mss(tp, to.to_mss);
11422 			if ((tp->t_flags & TF_SACK_PERMIT) &&
11423 			    (to.to_flags & TOF_SACKPERM) == 0)
11424 				tp->t_flags &= ~TF_SACK_PERMIT;
11425 			if (tp->t_flags & TF_FASTOPEN) {
11426 				if (to.to_flags & TOF_FASTOPEN) {
11427 					uint16_t mss;
11428 
11429 					if (to.to_flags & TOF_MSS)
11430 						mss = to.to_mss;
11431 					else
11432 						if ((inp->inp_vflag & INP_IPV6) != 0)
11433 							mss = TCP6_MSS;
11434 						else
11435 							mss = TCP_MSS;
11436 					tcp_fastopen_update_cache(tp, mss,
11437 					    to.to_tfo_len, to.to_tfo_cookie);
11438 				} else
11439 					tcp_fastopen_disable_path(tp);
11440 			}
11441 		}
11442 		/*
11443 		 * At this point we are at the initial call. Here we decide
11444 		 * if we are doing RACK or not. We do this by seeing if
11445 		 * TF_SACK_PERMIT is set, if not rack is *not* possible and
11446 		 * we switch to the default code.
11447 		 */
11448 		if ((tp->t_flags & TF_SACK_PERMIT) == 0) {
11449 			/* Bail */
11450 			tcp_switch_back_to_default(tp);
11451 			(*tp->t_fb->tfb_tcp_do_segment)(tp, m, th, drop_hdrlen,
11452 			    tlen, iptos);
11453 			return (1);
11454 		}
11455 		/* Set the flag */
11456 		bbr->r_is_v6 = (inp->inp_vflag & INP_IPV6) != 0;
11457 		tcp_set_hpts(tp);
11458 		sack_filter_clear(&bbr->r_ctl.bbr_sf, th->th_ack);
11459 	}
11460 	if (thflags & TH_ACK) {
11461 		/* Track ack types */
11462 		if (to.to_flags & TOF_SACK)
11463 			BBR_STAT_INC(bbr_acks_with_sacks);
11464 		else
11465 			BBR_STAT_INC(bbr_plain_acks);
11466 	}
11467 	/*
11468 	 * This is the one exception case where we set the rack state
11469 	 * always. All other times (timers etc) we must have a rack-state
11470 	 * set (so we assure we have done the checks above for SACK).
11471 	 */
11472 	if (thflags & TH_FIN)
11473 		tcp_log_end_status(tp, TCP_EI_STATUS_CLIENT_FIN);
11474 	if (bbr->r_state != tp->t_state)
11475 		bbr_set_state(tp, bbr, tiwin);
11476 
11477 	if (SEQ_GT(th->th_ack, tp->snd_una) && (rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map)) != NULL)
11478 		kern_prefetch(rsm, &prev_state);
11479 	prev_state = bbr->r_state;
11480 	bbr->rc_ack_was_delayed = 0;
11481 	lost = bbr->r_ctl.rc_lost;
11482 	bbr->rc_is_pkt_epoch_now = 0;
11483 	if (m->m_flags & (M_TSTMP|M_TSTMP_LRO)) {
11484 		/* Get the real time into lcts and figure the real delay */
11485 		lcts = tcp_get_usecs(&ltv);
11486 		if (TSTMP_GT(lcts, cts)) {
11487 			bbr->r_ctl.rc_ack_hdwr_delay = lcts - cts;
11488 			bbr->rc_ack_was_delayed = 1;
11489 			if (TSTMP_GT(bbr->r_ctl.rc_ack_hdwr_delay,
11490 				     bbr->r_ctl.highest_hdwr_delay))
11491 				bbr->r_ctl.highest_hdwr_delay = bbr->r_ctl.rc_ack_hdwr_delay;
11492 		} else {
11493 			bbr->r_ctl.rc_ack_hdwr_delay = 0;
11494 			bbr->rc_ack_was_delayed = 0;
11495 		}
11496 	} else {
11497 		bbr->r_ctl.rc_ack_hdwr_delay = 0;
11498 		bbr->rc_ack_was_delayed = 0;
11499 	}
11500 	bbr_log_ack_event(bbr, th, &to, tlen, nsegs, cts, nxt_pkt, m);
11501 	if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) {
11502 		retval = 0;
11503 		m_freem(m);
11504 		goto done_with_input;
11505 	}
11506 	/*
11507 	 * If a segment with the ACK-bit set arrives in the SYN-SENT state
11508 	 * check SEQ.ACK first as described on page 66 of RFC 793, section 3.9.
11509 	 */
11510 	if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) &&
11511 	    (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) {
11512 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11513 		ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11514 		return (1);
11515 	}
11516 	if (tiwin > bbr->r_ctl.rc_high_rwnd)
11517 		bbr->r_ctl.rc_high_rwnd = tiwin;
11518 	bbr->r_ctl.rc_flight_at_input = ctf_flight_size(tp,
11519 					    (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
11520 	bbr->rtt_valid = 0;
11521 	if (to.to_flags & TOF_TS) {
11522 		bbr->rc_ts_valid = 1;
11523 		bbr->r_ctl.last_inbound_ts = to.to_tsval;
11524 	} else {
11525 		bbr->rc_ts_valid = 0;
11526 		bbr->r_ctl.last_inbound_ts = 0;
11527 	}
11528 	retval = (*bbr->r_substate) (m, th, so,
11529 	    tp, &to, drop_hdrlen,
11530 	    tlen, tiwin, thflags, nxt_pkt, iptos);
11531 	if (nxt_pkt == 0)
11532 		BBR_STAT_INC(bbr_rlock_left_ret0);
11533 	else
11534 		BBR_STAT_INC(bbr_rlock_left_ret1);
11535 	if (retval == 0) {
11536 		/*
11537 		 * If retval is 1 the tcb is unlocked and most likely the tp
11538 		 * is gone.
11539 		 */
11540 		INP_WLOCK_ASSERT(inp);
11541 		tcp_bbr_xmit_timer_commit(bbr, tp, cts);
11542 		if (bbr->rc_is_pkt_epoch_now)
11543 			bbr_set_pktepoch(bbr, cts, __LINE__);
11544 		bbr_check_bbr_for_state(bbr, cts, __LINE__, (bbr->r_ctl.rc_lost - lost));
11545 		if (nxt_pkt == 0) {
11546 			if ((bbr->r_wanted_output != 0) ||
11547 			    (tp->t_flags & TF_ACKNOW)) {
11548 
11549 				bbr->rc_output_starts_timer = 0;
11550 				did_out = 1;
11551 				if (tcp_output(tp) < 0)
11552 					return (1);
11553 			} else
11554 				bbr_start_hpts_timer(bbr, tp, cts, 6, 0, 0);
11555 		}
11556 		if ((nxt_pkt == 0) &&
11557 		    ((bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK) == 0) &&
11558 		    (SEQ_GT(tp->snd_max, tp->snd_una) ||
11559 		     (tp->t_flags & TF_DELACK) ||
11560 		     ((V_tcp_always_keepalive || bbr->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
11561 		      (tp->t_state <= TCPS_CLOSING)))) {
11562 			/*
11563 			 * We could not send (probably in the hpts but
11564 			 * stopped the timer)?
11565 			 */
11566 			if ((tp->snd_max == tp->snd_una) &&
11567 			    ((tp->t_flags & TF_DELACK) == 0) &&
11568 			    (tcp_in_hpts(tp)) &&
11569 			    (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
11570 				/*
11571 				 * keep alive not needed if we are hptsi
11572 				 * output yet
11573 				 */
11574 				;
11575 			} else {
11576 				if (tcp_in_hpts(tp)) {
11577 					tcp_hpts_remove(tp);
11578 					if ((bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
11579 					    (TSTMP_GT(lcts, bbr->rc_pacer_started))) {
11580 						uint32_t del;
11581 
11582 						del = lcts - bbr->rc_pacer_started;
11583 						if (bbr->r_ctl.rc_last_delay_val > del) {
11584 							BBR_STAT_INC(bbr_force_timer_start);
11585 							bbr->r_ctl.rc_last_delay_val -= del;
11586 							bbr->rc_pacer_started = lcts;
11587 						} else {
11588 							/* We are late */
11589 							bbr->r_ctl.rc_last_delay_val = 0;
11590 							BBR_STAT_INC(bbr_force_output);
11591 							if (tcp_output(tp) < 0)
11592 								return (1);
11593 						}
11594 					}
11595 				}
11596 				bbr_start_hpts_timer(bbr, tp, cts, 8, bbr->r_ctl.rc_last_delay_val,
11597 				    0);
11598 			}
11599 		} else if ((bbr->rc_output_starts_timer == 0) && (nxt_pkt == 0)) {
11600 			/* Do we have the correct timer running? */
11601 			bbr_timer_audit(tp, bbr, lcts, &so->so_snd);
11602 		}
11603 		/* Clear the flag, it may have been cleared by output but we may not have  */
11604 		if ((nxt_pkt == 0) && (tp->t_flags2 & TF2_HPTS_CALLS))
11605 			tp->t_flags2 &= ~TF2_HPTS_CALLS;
11606 		/* Do we have a new state */
11607 		if (bbr->r_state != tp->t_state)
11608 			bbr_set_state(tp, bbr, tiwin);
11609 done_with_input:
11610 		bbr_log_doseg_done(bbr, cts, nxt_pkt, did_out);
11611 		if (did_out)
11612 			bbr->r_wanted_output = 0;
11613 	}
11614 	return (retval);
11615 }
11616 
11617 static void
11618 bbr_do_segment(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
11619     int32_t drop_hdrlen, int32_t tlen, uint8_t iptos)
11620 {
11621 	struct timeval tv;
11622 	int retval;
11623 
11624 	/* First lets see if we have old packets */
11625 	if (!STAILQ_EMPTY(&tp->t_inqueue)) {
11626 		if (ctf_do_queued_segments(tp, 1)) {
11627 			m_freem(m);
11628 			return;
11629 		}
11630 	}
11631 	if (m->m_flags & M_TSTMP_LRO) {
11632 		mbuf_tstmp2timeval(m, &tv);
11633 	} else {
11634 		/* Should not be should we kassert instead? */
11635 		tcp_get_usecs(&tv);
11636 	}
11637 	retval = bbr_do_segment_nounlock(tp, m, th, drop_hdrlen, tlen, iptos,
11638 	    0, &tv);
11639 	if (retval == 0) {
11640 		INP_WUNLOCK(tptoinpcb(tp));
11641 	}
11642 }
11643 
11644 /*
11645  * Return how much data can be sent without violating the
11646  * cwnd or rwnd.
11647  */
11648 
11649 static inline uint32_t
11650 bbr_what_can_we_send(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t sendwin,
11651     uint32_t avail, int32_t sb_offset, uint32_t cts)
11652 {
11653 	uint32_t len;
11654 
11655 	if (ctf_outstanding(tp) >= tp->snd_wnd) {
11656 		/* We never want to go over our peers rcv-window */
11657 		len = 0;
11658 	} else {
11659 		uint32_t flight;
11660 
11661 		flight = ctf_flight_size(tp, (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
11662 		if (flight >= sendwin) {
11663 			/*
11664 			 * We have in flight what we are allowed by cwnd (if
11665 			 * it was rwnd blocking it would have hit above out
11666 			 * >= tp->snd_wnd).
11667 			 */
11668 			return (0);
11669 		}
11670 		len = sendwin - flight;
11671 		if ((len + ctf_outstanding(tp)) > tp->snd_wnd) {
11672 			/* We would send too much (beyond the rwnd) */
11673 			len = tp->snd_wnd - ctf_outstanding(tp);
11674 		}
11675 		if ((len + sb_offset) > avail) {
11676 			/*
11677 			 * We don't have that much in the SB, how much is
11678 			 * there?
11679 			 */
11680 			len = avail - sb_offset;
11681 		}
11682 	}
11683 	return (len);
11684 }
11685 
11686 static inline void
11687 bbr_do_send_accounting(struct tcpcb *tp, struct tcp_bbr *bbr, struct bbr_sendmap *rsm, int32_t len, int32_t error)
11688 {
11689 	if (error) {
11690 		return;
11691 	}
11692 	if (rsm) {
11693 		if (rsm->r_flags & BBR_TLP) {
11694 			/*
11695 			 * TLP should not count in retran count, but in its
11696 			 * own bin
11697 			 */
11698 			KMOD_TCPSTAT_INC(tcps_tlpresends);
11699 			KMOD_TCPSTAT_ADD(tcps_tlpresend_bytes, len);
11700 		} else {
11701 			/* Retransmit */
11702 			tp->t_sndrexmitpack++;
11703 			KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
11704 			KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
11705 #ifdef STATS
11706 			stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
11707 			    len);
11708 #endif
11709 		}
11710 		/*
11711 		 * Logs in 0 - 8, 8 is all non probe_bw states 0-7 is
11712 		 * sub-state
11713 		 */
11714 		counter_u64_add(bbr_state_lost[rsm->r_bbr_state], len);
11715 		if (bbr->rc_bbr_state != BBR_STATE_PROBE_BW) {
11716 			/* Non probe_bw log in 1, 2, or 4. */
11717 			counter_u64_add(bbr_state_resend[bbr->rc_bbr_state], len);
11718 		} else {
11719 			/*
11720 			 * Log our probe state 3, and log also 5-13 to show
11721 			 * us the recovery sub-state for the send. This
11722 			 * means that 3 == (5+6+7+8+9+10+11+12+13)
11723 			 */
11724 			counter_u64_add(bbr_state_resend[BBR_STATE_PROBE_BW], len);
11725 			counter_u64_add(bbr_state_resend[(bbr_state_val(bbr) + 5)], len);
11726 		}
11727 		/* Place in both 16's the totals of retransmitted */
11728 		counter_u64_add(bbr_state_lost[16], len);
11729 		counter_u64_add(bbr_state_resend[16], len);
11730 		/* Place in 17's the total sent */
11731 		counter_u64_add(bbr_state_resend[17], len);
11732 		counter_u64_add(bbr_state_lost[17], len);
11733 
11734 	} else {
11735 		/* New sends */
11736 		KMOD_TCPSTAT_INC(tcps_sndpack);
11737 		KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
11738 		/* Place in 17's the total sent */
11739 		counter_u64_add(bbr_state_resend[17], len);
11740 		counter_u64_add(bbr_state_lost[17], len);
11741 #ifdef STATS
11742 		stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
11743 		    len);
11744 #endif
11745 	}
11746 }
11747 
11748 static void
11749 bbr_cwnd_limiting(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t in_level)
11750 {
11751 	if (bbr->rc_filled_pipe && bbr_target_cwnd_mult_limit && (bbr->rc_use_google == 0)) {
11752 		/*
11753 		 * Limit the cwnd to not be above N x the target plus whats
11754 		 * is outstanding. The target is based on the current b/w
11755 		 * estimate.
11756 		 */
11757 		uint32_t target;
11758 
11759 		target = bbr_get_target_cwnd(bbr, bbr_get_bw(bbr), BBR_UNIT);
11760 		target += ctf_outstanding(tp);
11761 		target *= bbr_target_cwnd_mult_limit;
11762 		if (tp->snd_cwnd > target)
11763 			tp->snd_cwnd = target;
11764 		bbr_log_type_cwndupd(bbr, 0, 0, 0, 10, 0, 0, __LINE__);
11765 	}
11766 }
11767 
11768 static int
11769 bbr_window_update_needed(struct tcpcb *tp, struct socket *so, uint32_t recwin, int32_t maxseg)
11770 {
11771 	/*
11772 	 * "adv" is the amount we could increase the window, taking into
11773 	 * account that we are limited by TCP_MAXWIN << tp->rcv_scale.
11774 	 */
11775 	int32_t adv;
11776 	int32_t oldwin;
11777 
11778 	adv = recwin;
11779 	if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt)) {
11780 		oldwin = (tp->rcv_adv - tp->rcv_nxt);
11781 		if (adv > oldwin)
11782 			adv -= oldwin;
11783 		else {
11784 			/* We can't increase the window */
11785 			adv = 0;
11786 		}
11787 	} else
11788 		oldwin = 0;
11789 
11790 	/*
11791 	 * If the new window size ends up being the same as or less
11792 	 * than the old size when it is scaled, then don't force
11793 	 * a window update.
11794 	 */
11795 	if (oldwin >> tp->rcv_scale >= (adv + oldwin) >> tp->rcv_scale)
11796 		return (0);
11797 
11798 	if (adv >= (2 * maxseg) &&
11799 	    (adv >= (so->so_rcv.sb_hiwat / 4) ||
11800 	    recwin <= (so->so_rcv.sb_hiwat / 8) ||
11801 	    so->so_rcv.sb_hiwat <= 8 * maxseg)) {
11802 		return (1);
11803 	}
11804 	if (2 * adv >= (int32_t) so->so_rcv.sb_hiwat)
11805 		return (1);
11806 	return (0);
11807 }
11808 
11809 /*
11810  * Return 0 on success and a errno on failure to send.
11811  * Note that a 0 return may not mean we sent anything
11812  * if the TCB was on the hpts. A non-zero return
11813  * does indicate the error we got from ip[6]_output.
11814  */
11815 static int
11816 bbr_output_wtime(struct tcpcb *tp, const struct timeval *tv)
11817 {
11818 	struct socket *so;
11819 	int32_t len;
11820 	uint32_t cts;
11821 	uint32_t recwin, sendwin;
11822 	int32_t sb_offset;
11823 	int32_t flags, abandon, error = 0;
11824 	struct tcp_log_buffer *lgb;
11825 	struct mbuf *m;
11826 	struct mbuf *mb;
11827 	uint32_t if_hw_tsomaxsegcount = 0;
11828 	uint32_t if_hw_tsomaxsegsize = 0;
11829 	uint32_t if_hw_tsomax = 0;
11830 	struct ip *ip = NULL;
11831 	struct tcp_bbr *bbr;
11832 	struct tcphdr *th;
11833 	struct udphdr *udp = NULL;
11834 	u_char opt[TCP_MAXOLEN];
11835 	unsigned ipoptlen, optlen, hdrlen;
11836 	unsigned ulen;
11837 	uint32_t bbr_seq;
11838 	uint32_t delay_calc=0;
11839 	uint8_t doing_tlp = 0;
11840 	uint8_t local_options;
11841 #ifdef BBR_INVARIANTS
11842 	uint8_t doing_retran_from = 0;
11843 	uint8_t picked_up_retran = 0;
11844 #endif
11845 	uint8_t wanted_cookie = 0;
11846 	uint8_t more_to_rxt=0;
11847 	int32_t prefetch_so_done = 0;
11848 	int32_t prefetch_rsm = 0;
11849 	uint32_t tot_len = 0;
11850 	uint32_t maxseg, pace_max_segs, p_maxseg;
11851 	int32_t csum_flags = 0;
11852  	int32_t hw_tls;
11853 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
11854 	unsigned ipsec_optlen = 0;
11855 
11856 #endif
11857 	volatile int32_t sack_rxmit;
11858 	struct bbr_sendmap *rsm = NULL;
11859 	int32_t tso, mtu;
11860 	struct tcpopt to;
11861 	int32_t slot = 0;
11862 	struct inpcb *inp;
11863 	struct sockbuf *sb;
11864 	bool hpts_calling;
11865 #ifdef INET6
11866 	struct ip6_hdr *ip6 = NULL;
11867 	int32_t isipv6;
11868 #endif
11869 	uint8_t app_limited = BBR_JR_SENT_DATA;
11870 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
11871 	/* We take a cache hit here */
11872 	memcpy(&bbr->rc_tv, tv, sizeof(struct timeval));
11873 	cts = tcp_tv_to_usectick(&bbr->rc_tv);
11874 	inp = bbr->rc_inp;
11875 	hpts_calling = !!(tp->t_flags2 & TF2_HPTS_CALLS);
11876 	tp->t_flags2 &= ~TF2_HPTS_CALLS;
11877 	so = inp->inp_socket;
11878 	sb = &so->so_snd;
11879 	if (tp->t_nic_ktls_xmit)
11880  		hw_tls = 1;
11881  	else
11882  		hw_tls = 0;
11883 	kern_prefetch(sb, &maxseg);
11884 	maxseg = tp->t_maxseg - bbr->rc_last_options;
11885 	if (bbr_minseg(bbr) < maxseg) {
11886 		tcp_bbr_tso_size_check(bbr, cts);
11887 	}
11888 	/* Remove any flags that indicate we are pacing on the inp  */
11889 	pace_max_segs = bbr->r_ctl.rc_pace_max_segs;
11890 	p_maxseg = min(maxseg, pace_max_segs);
11891 	INP_WLOCK_ASSERT(inp);
11892 #ifdef TCP_OFFLOAD
11893 	if (tp->t_flags & TF_TOE)
11894 		return (tcp_offload_output(tp));
11895 #endif
11896 
11897 #ifdef INET6
11898 	if (bbr->r_state) {
11899 		/* Use the cache line loaded if possible */
11900 		isipv6 = bbr->r_is_v6;
11901 	} else {
11902 		isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
11903 	}
11904 #endif
11905 	if (((bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) &&
11906 	    tcp_in_hpts(tp)) {
11907 		/*
11908 		 * We are on the hpts for some timer but not hptsi output.
11909 		 * Possibly remove from the hpts so we can send/recv etc.
11910 		 */
11911 		if ((tp->t_flags & TF_ACKNOW) == 0) {
11912 			/*
11913 			 * No immediate demand right now to send an ack, but
11914 			 * the user may have read, making room for new data
11915 			 * (a window update). If so we may want to cancel
11916 			 * whatever timer is running (KEEP/DEL-ACK?) and
11917 			 * continue to send out a window update. Or we may
11918 			 * have gotten more data into the socket buffer to
11919 			 * send.
11920 			 */
11921 			recwin = lmin(lmax(sbspace(&so->so_rcv), 0),
11922 				      (long)TCP_MAXWIN << tp->rcv_scale);
11923 			if ((bbr_window_update_needed(tp, so, recwin, maxseg) == 0) &&
11924 			    ((tcp_outflags[tp->t_state] & TH_RST) == 0) &&
11925 			    ((sbavail(sb) + ((tcp_outflags[tp->t_state] & TH_FIN) ? 1 : 0)) <=
11926 			    (tp->snd_max - tp->snd_una))) {
11927 				/*
11928 				 * Nothing new to send and no window update
11929 				 * is needed to send. Lets just return and
11930 				 * let the timer-run off.
11931 				 */
11932 				return (0);
11933 			}
11934 		}
11935 		tcp_hpts_remove(tp);
11936 		bbr_timer_cancel(bbr, __LINE__, cts);
11937 	}
11938 	if (bbr->r_ctl.rc_last_delay_val) {
11939 		/* Calculate a rough delay for early escape to sending  */
11940 		if (SEQ_GT(cts, bbr->rc_pacer_started))
11941 			delay_calc = cts - bbr->rc_pacer_started;
11942 		if (delay_calc >= bbr->r_ctl.rc_last_delay_val)
11943 			delay_calc -= bbr->r_ctl.rc_last_delay_val;
11944 		else
11945 			delay_calc = 0;
11946 	}
11947 	/* Mark that we have called bbr_output(). */
11948 	if ((bbr->r_timer_override) ||
11949 	    (tp->t_state < TCPS_ESTABLISHED)) {
11950 		/* Timeouts or early states are exempt */
11951 		if (tcp_in_hpts(tp))
11952 			tcp_hpts_remove(tp);
11953 	} else if (tcp_in_hpts(tp)) {
11954 		if ((bbr->r_ctl.rc_last_delay_val) &&
11955 		    (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
11956 		    delay_calc) {
11957 			/*
11958 			 * We were being paced for output and the delay has
11959 			 * already exceeded when we were supposed to be
11960 			 * called, lets go ahead and pull out of the hpts
11961 			 * and call output.
11962 			 */
11963 			counter_u64_add(bbr_out_size[TCP_MSS_ACCT_LATE], 1);
11964 			bbr->r_ctl.rc_last_delay_val = 0;
11965 			tcp_hpts_remove(tp);
11966 		} else if (tp->t_state == TCPS_CLOSED) {
11967 			bbr->r_ctl.rc_last_delay_val = 0;
11968 			tcp_hpts_remove(tp);
11969 		} else {
11970 			/*
11971 			 * On the hpts, you shall not pass! even if ACKNOW
11972 			 * is on, we will when the hpts fires, unless of
11973 			 * course we are overdue.
11974 			 */
11975 			counter_u64_add(bbr_out_size[TCP_MSS_ACCT_INPACE], 1);
11976 			return (0);
11977 		}
11978 	}
11979 	bbr->rc_cwnd_limited = 0;
11980 	if (bbr->r_ctl.rc_last_delay_val) {
11981 		/* recalculate the real delay and deal with over/under  */
11982 		if (SEQ_GT(cts, bbr->rc_pacer_started))
11983 			delay_calc = cts - bbr->rc_pacer_started;
11984 		else
11985 			delay_calc = 0;
11986 		if (delay_calc >= bbr->r_ctl.rc_last_delay_val)
11987 			/* Setup the delay which will be added in */
11988 			delay_calc -= bbr->r_ctl.rc_last_delay_val;
11989 		else {
11990 			/*
11991 			 * We are early setup to adjust
11992 			 * our slot time.
11993 			 */
11994 			uint64_t merged_val;
11995 
11996 			bbr->r_ctl.rc_agg_early += (bbr->r_ctl.rc_last_delay_val - delay_calc);
11997 			bbr->r_agg_early_set = 1;
11998 			if (bbr->r_ctl.rc_hptsi_agg_delay) {
11999 				if (bbr->r_ctl.rc_hptsi_agg_delay >= bbr->r_ctl.rc_agg_early) {
12000 					/* Nope our previous late cancels out the early */
12001 					bbr->r_ctl.rc_hptsi_agg_delay -= bbr->r_ctl.rc_agg_early;
12002 					bbr->r_agg_early_set = 0;
12003 					bbr->r_ctl.rc_agg_early = 0;
12004 				} else {
12005 					bbr->r_ctl.rc_agg_early -= bbr->r_ctl.rc_hptsi_agg_delay;
12006 					bbr->r_ctl.rc_hptsi_agg_delay = 0;
12007 				}
12008 			}
12009 			merged_val = bbr->rc_pacer_started;
12010 			merged_val <<= 32;
12011 			merged_val |= bbr->r_ctl.rc_last_delay_val;
12012 			bbr_log_pacing_delay_calc(bbr, hpts_calling,
12013 						 bbr->r_ctl.rc_agg_early, cts, delay_calc, merged_val,
12014 						 bbr->r_agg_early_set, 3);
12015 			bbr->r_ctl.rc_last_delay_val = 0;
12016 			BBR_STAT_INC(bbr_early);
12017 			delay_calc = 0;
12018 		}
12019 	} else {
12020 		/* We were not delayed due to hptsi */
12021 		if (bbr->r_agg_early_set)
12022 			bbr->r_ctl.rc_agg_early = 0;
12023 		bbr->r_agg_early_set = 0;
12024 		delay_calc = 0;
12025 	}
12026 	if (delay_calc) {
12027 		/*
12028 		 * We had a hptsi delay which means we are falling behind on
12029 		 * sending at the expected rate. Calculate an extra amount
12030 		 * of data we can send, if any, to put us back on track.
12031 		 */
12032 		if ((bbr->r_ctl.rc_hptsi_agg_delay + delay_calc) < bbr->r_ctl.rc_hptsi_agg_delay)
12033 			bbr->r_ctl.rc_hptsi_agg_delay = 0xffffffff;
12034 		else
12035 			bbr->r_ctl.rc_hptsi_agg_delay += delay_calc;
12036 	}
12037 	sendwin = min(tp->snd_wnd, tp->snd_cwnd);
12038 	if ((tp->snd_una == tp->snd_max) &&
12039 	    (bbr->rc_bbr_state != BBR_STATE_IDLE_EXIT) &&
12040 	    (sbavail(sb))) {
12041 		/*
12042 		 * Ok we have been idle with nothing outstanding
12043 		 * we possibly need to start fresh with either a new
12044 		 * suite of states or a fast-ramp up.
12045 		 */
12046 		bbr_restart_after_idle(bbr,
12047 				       cts, bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time));
12048 	}
12049 	/*
12050 	 * Now was there a hptsi delay where we are behind? We only count
12051 	 * being behind if: a) We are not in recovery. b) There was a delay.
12052 	 * <and> c) We had room to send something.
12053 	 *
12054 	 */
12055 	if (bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
12056 		int retval;
12057 
12058 		retval = bbr_process_timers(tp, bbr, cts, hpts_calling);
12059 		if (retval != 0) {
12060 			counter_u64_add(bbr_out_size[TCP_MSS_ACCT_ATIMER], 1);
12061 			/*
12062 			 * If timers want tcp_drop(), then pass error out,
12063 			 * otherwise suppress it.
12064 			 */
12065 			return (retval < 0 ? retval : 0);
12066 		}
12067 	}
12068 	bbr->rc_tp->t_flags2 &= ~TF2_MBUF_QUEUE_READY;
12069 	if (hpts_calling &&
12070 	    (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
12071 		bbr->r_ctl.rc_last_delay_val = 0;
12072 	}
12073 	bbr->r_timer_override = 0;
12074 	bbr->r_wanted_output = 0;
12075 	/*
12076 	 * For TFO connections in SYN_RECEIVED, only allow the initial
12077 	 * SYN|ACK and those sent by the retransmit timer.
12078 	 */
12079 	if ((tp->t_flags & TF_FASTOPEN) &&
12080 	    ((tp->t_state == TCPS_SYN_RECEIVED) ||
12081 	     (tp->t_state == TCPS_SYN_SENT)) &&
12082 	    SEQ_GT(tp->snd_max, tp->snd_una) &&	/* initial SYN or SYN|ACK sent */
12083 	    (tp->t_rxtshift == 0)) {	/* not a retransmit */
12084 		len = 0;
12085 		goto just_return_nolock;
12086 	}
12087 	/*
12088 	 * Before sending anything check for a state update. For hpts
12089 	 * calling without input this is important. If its input calling
12090 	 * then this was already done.
12091 	 */
12092 	if (bbr->rc_use_google == 0)
12093 		bbr_check_bbr_for_state(bbr, cts, __LINE__, 0);
12094 again:
12095 	/*
12096 	 * If we've recently taken a timeout, snd_max will be greater than
12097 	 * snd_max. BBR in general does not pay much attention to snd_nxt
12098 	 * for historic reasons the persist timer still uses it. This means
12099 	 * we have to look at it. All retransmissions that are not persits
12100 	 * use the rsm that needs to be sent so snd_nxt is ignored. At the
12101 	 * end of this routine we pull snd_nxt always up to snd_max.
12102 	 */
12103 	doing_tlp = 0;
12104 #ifdef BBR_INVARIANTS
12105 	doing_retran_from = picked_up_retran = 0;
12106 #endif
12107 	error = 0;
12108 	tso = 0;
12109 	slot = 0;
12110 	mtu = 0;
12111 	sendwin = min(tp->snd_wnd, tp->snd_cwnd);
12112 	sb_offset = tp->snd_max - tp->snd_una;
12113 	flags = tcp_outflags[tp->t_state];
12114 	sack_rxmit = 0;
12115 	len = 0;
12116 	rsm = NULL;
12117 	if (flags & TH_RST) {
12118 		SOCK_SENDBUF_LOCK(so);
12119 		goto send;
12120 	}
12121 recheck_resend:
12122 	while (bbr->r_ctl.rc_free_cnt < bbr_min_req_free) {
12123 		/* We need to always have one in reserve */
12124 		rsm = bbr_alloc(bbr);
12125 		if (rsm == NULL) {
12126 			error = ENOMEM;
12127 			/* Lie to get on the hpts */
12128 			tot_len = tp->t_maxseg;
12129 			if (hpts_calling)
12130 				/* Retry in a ms */
12131 				slot = 1001;
12132 			goto just_return_nolock;
12133 		}
12134 		TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_free, rsm, r_next);
12135 		bbr->r_ctl.rc_free_cnt++;
12136 		rsm = NULL;
12137 	}
12138 	/* What do we send, a resend? */
12139 	if (bbr->r_ctl.rc_resend == NULL) {
12140 		/* Check for rack timeout */
12141 		bbr->r_ctl.rc_resend = bbr_check_recovery_mode(tp, bbr, cts);
12142 		if (bbr->r_ctl.rc_resend) {
12143 #ifdef BBR_INVARIANTS
12144 			picked_up_retran = 1;
12145 #endif
12146 			bbr_cong_signal(tp, NULL, CC_NDUPACK, bbr->r_ctl.rc_resend);
12147 		}
12148 	}
12149 	if (bbr->r_ctl.rc_resend) {
12150 		rsm = bbr->r_ctl.rc_resend;
12151 #ifdef BBR_INVARIANTS
12152 		doing_retran_from = 1;
12153 #endif
12154 		/* Remove any TLP flags its a RACK or T-O */
12155 		rsm->r_flags &= ~BBR_TLP;
12156 		bbr->r_ctl.rc_resend = NULL;
12157 		if (SEQ_LT(rsm->r_start, tp->snd_una)) {
12158 #ifdef BBR_INVARIANTS
12159 			panic("Huh, tp:%p bbr:%p rsm:%p start:%u < snd_una:%u\n",
12160 			    tp, bbr, rsm, rsm->r_start, tp->snd_una);
12161 			goto recheck_resend;
12162 #else
12163 			/* TSNH */
12164 			rsm = NULL;
12165 			goto recheck_resend;
12166 #endif
12167 		}
12168 		if (rsm->r_flags & BBR_HAS_SYN) {
12169 			/* Only retransmit a SYN by itself */
12170 			len = 0;
12171 			if ((flags & TH_SYN) == 0) {
12172 				/* Huh something is wrong */
12173 				rsm->r_start++;
12174 				if (rsm->r_start == rsm->r_end) {
12175 					/* Clean it up, somehow we missed the ack? */
12176 					bbr_log_syn(tp, NULL);
12177 				} else {
12178 					/* TFO with data? */
12179 					rsm->r_flags &= ~BBR_HAS_SYN;
12180 					len = rsm->r_end - rsm->r_start;
12181 				}
12182 			} else {
12183 				/* Retransmitting SYN */
12184 				rsm = NULL;
12185 				SOCK_SENDBUF_LOCK(so);
12186 				goto send;
12187 			}
12188 		} else
12189 			len = rsm->r_end - rsm->r_start;
12190 		if ((bbr->rc_resends_use_tso == 0) &&
12191 		    (len > maxseg)) {
12192 			len = maxseg;
12193 			more_to_rxt = 1;
12194 		}
12195 		sb_offset = rsm->r_start - tp->snd_una;
12196 		if (len > 0) {
12197 			sack_rxmit = 1;
12198 			KMOD_TCPSTAT_INC(tcps_sack_rexmits);
12199 			KMOD_TCPSTAT_ADD(tcps_sack_rexmit_bytes,
12200 			    min(len, maxseg));
12201 		} else {
12202 			/* I dont think this can happen */
12203 			rsm = NULL;
12204 			goto recheck_resend;
12205 		}
12206 		BBR_STAT_INC(bbr_resends_set);
12207 	} else if (bbr->r_ctl.rc_tlp_send) {
12208 		/*
12209 		 * Tail loss probe
12210 		 */
12211 		doing_tlp = 1;
12212 		rsm = bbr->r_ctl.rc_tlp_send;
12213 		bbr->r_ctl.rc_tlp_send = NULL;
12214 		sack_rxmit = 1;
12215 		len = rsm->r_end - rsm->r_start;
12216 		if ((bbr->rc_resends_use_tso == 0) && (len > maxseg))
12217 			len = maxseg;
12218 
12219 		if (SEQ_GT(tp->snd_una, rsm->r_start)) {
12220 #ifdef BBR_INVARIANTS
12221 			panic("tp:%p bbc:%p snd_una:%u rsm:%p r_start:%u",
12222 			    tp, bbr, tp->snd_una, rsm, rsm->r_start);
12223 #else
12224 			/* TSNH */
12225 			rsm = NULL;
12226 			goto recheck_resend;
12227 #endif
12228 		}
12229 		sb_offset = rsm->r_start - tp->snd_una;
12230 		BBR_STAT_INC(bbr_tlp_set);
12231 	}
12232 	/*
12233 	 * Enforce a connection sendmap count limit if set
12234 	 * as long as we are not retransmiting.
12235 	 */
12236 	if ((rsm == NULL) &&
12237 	    (V_tcp_map_entries_limit > 0) &&
12238 	    (bbr->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
12239 		BBR_STAT_INC(bbr_alloc_limited);
12240 		if (!bbr->alloc_limit_reported) {
12241 			bbr->alloc_limit_reported = 1;
12242 			BBR_STAT_INC(bbr_alloc_limited_conns);
12243 		}
12244 		goto just_return_nolock;
12245 	}
12246 #ifdef BBR_INVARIANTS
12247 	if (rsm && SEQ_LT(rsm->r_start, tp->snd_una)) {
12248 		panic("tp:%p bbr:%p rsm:%p sb_offset:%u len:%u",
12249 		    tp, bbr, rsm, sb_offset, len);
12250 	}
12251 #endif
12252 	/*
12253 	 * Get standard flags, and add SYN or FIN if requested by 'hidden'
12254 	 * state flags.
12255 	 */
12256 	if (tp->t_flags & TF_NEEDFIN && (rsm == NULL))
12257 		flags |= TH_FIN;
12258 	if (tp->t_flags & TF_NEEDSYN)
12259 		flags |= TH_SYN;
12260 
12261 	if (rsm && (rsm->r_flags & BBR_HAS_FIN)) {
12262 		/* we are retransmitting the fin */
12263 		len--;
12264 		if (len) {
12265 			/*
12266 			 * When retransmitting data do *not* include the
12267 			 * FIN. This could happen from a TLP probe if we
12268 			 * allowed data with a FIN.
12269 			 */
12270 			flags &= ~TH_FIN;
12271 		}
12272 	} else if (rsm) {
12273 		if (flags & TH_FIN)
12274 			flags &= ~TH_FIN;
12275 	}
12276 	if ((sack_rxmit == 0) && (prefetch_rsm == 0)) {
12277 		void *end_rsm;
12278 
12279 		end_rsm = TAILQ_LAST_FAST(&bbr->r_ctl.rc_tmap, bbr_sendmap, r_tnext);
12280 		if (end_rsm)
12281 			kern_prefetch(end_rsm, &prefetch_rsm);
12282 		prefetch_rsm = 1;
12283 	}
12284 	SOCK_SENDBUF_LOCK(so);
12285 	/*
12286 	 * If snd_nxt == snd_max and we have transmitted a FIN, the
12287 	 * sb_offset will be > 0 even if so_snd.sb_cc is 0, resulting in a
12288 	 * negative length.  This can also occur when TCP opens up its
12289 	 * congestion window while receiving additional duplicate acks after
12290 	 * fast-retransmit because TCP will reset snd_nxt to snd_max after
12291 	 * the fast-retransmit.
12292 	 *
12293 	 * In the normal retransmit-FIN-only case, however, snd_nxt will be
12294 	 * set to snd_una, the sb_offset will be 0, and the length may wind
12295 	 * up 0.
12296 	 *
12297 	 * If sack_rxmit is true we are retransmitting from the scoreboard
12298 	 * in which case len is already set.
12299 	 */
12300 	if (sack_rxmit == 0) {
12301 		uint32_t avail;
12302 
12303 		avail = sbavail(sb);
12304 		if (SEQ_GT(tp->snd_max, tp->snd_una))
12305 			sb_offset = tp->snd_max - tp->snd_una;
12306 		else
12307 			sb_offset = 0;
12308 		if (bbr->rc_tlp_new_data) {
12309 			/* TLP is forcing out new data */
12310 			uint32_t tlplen;
12311 
12312 			doing_tlp = 1;
12313 			tlplen = maxseg;
12314 
12315 			if (tlplen > (uint32_t)(avail - sb_offset)) {
12316 				tlplen = (uint32_t)(avail - sb_offset);
12317 			}
12318 			if (tlplen > tp->snd_wnd) {
12319 				len = tp->snd_wnd;
12320 			} else {
12321 				len = tlplen;
12322 			}
12323 			bbr->rc_tlp_new_data = 0;
12324 		} else {
12325 			len = bbr_what_can_we_send(tp, bbr, sendwin, avail, sb_offset, cts);
12326 			if ((len < p_maxseg) &&
12327 			    (bbr->rc_in_persist == 0) &&
12328 			    (ctf_outstanding(tp) >= (2 * p_maxseg)) &&
12329 			    ((avail - sb_offset) >= p_maxseg)) {
12330 				/*
12331 				 * We are not completing whats in the socket
12332 				 * buffer (i.e. there is at least a segment
12333 				 * waiting to send) and we have 2 or more
12334 				 * segments outstanding. There is no sense
12335 				 * of sending a little piece. Lets defer and
12336 				 * and wait until we can send a whole
12337 				 * segment.
12338 				 */
12339 				len = 0;
12340 			}
12341 			if (bbr->rc_in_persist) {
12342 				/*
12343 				 * We are in persists, figure out if
12344 				 * a retransmit is available (maybe the previous
12345 				 * persists we sent) or if we have to send new
12346 				 * data.
12347 				 */
12348 				rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
12349 				if (rsm) {
12350 					len = rsm->r_end - rsm->r_start;
12351 					if (rsm->r_flags & BBR_HAS_FIN)
12352 						len--;
12353 					if ((bbr->rc_resends_use_tso == 0) && (len > maxseg))
12354 						len = maxseg;
12355 					if (len > 1)
12356 						BBR_STAT_INC(bbr_persist_reneg);
12357 					/*
12358 					 * XXXrrs we could force the len to
12359 					 * 1 byte here to cause the chunk to
12360 					 * split apart.. but that would then
12361 					 * mean we always retransmit it as
12362 					 * one byte even after the window
12363 					 * opens.
12364 					 */
12365 					sack_rxmit = 1;
12366 					sb_offset = rsm->r_start - tp->snd_una;
12367 				} else {
12368 					/*
12369 					 * First time through in persists or peer
12370 					 * acked our one byte. Though we do have
12371 					 * to have something in the sb.
12372 					 */
12373 					len = 1;
12374 					sb_offset = 0;
12375 					if (avail == 0)
12376 					    len = 0;
12377 				}
12378 			}
12379 		}
12380 	}
12381 	if (prefetch_so_done == 0) {
12382 		kern_prefetch(so, &prefetch_so_done);
12383 		prefetch_so_done = 1;
12384 	}
12385 	/*
12386 	 * Lop off SYN bit if it has already been sent.  However, if this is
12387 	 * SYN-SENT state and if segment contains data and if we don't know
12388 	 * that foreign host supports TAO, suppress sending segment.
12389 	 */
12390 	if ((flags & TH_SYN) && (rsm == NULL) &&
12391 	    SEQ_GT(tp->snd_max, tp->snd_una)) {
12392 		if (tp->t_state != TCPS_SYN_RECEIVED)
12393 			flags &= ~TH_SYN;
12394 		/*
12395 		 * When sending additional segments following a TFO SYN|ACK,
12396 		 * do not include the SYN bit.
12397 		 */
12398 		if ((tp->t_flags & TF_FASTOPEN) &&
12399 		    (tp->t_state == TCPS_SYN_RECEIVED))
12400 			flags &= ~TH_SYN;
12401 		sb_offset--, len++;
12402 		if (sbavail(sb) == 0)
12403 			len = 0;
12404 	} else if ((flags & TH_SYN) && rsm) {
12405 		/*
12406 		 * Subtract one from the len for the SYN being
12407 		 * retransmitted.
12408 		 */
12409 		len--;
12410 	}
12411 	/*
12412 	 * Be careful not to send data and/or FIN on SYN segments. This
12413 	 * measure is needed to prevent interoperability problems with not
12414 	 * fully conformant TCP implementations.
12415 	 */
12416 	if ((flags & TH_SYN) && (tp->t_flags & TF_NOOPT)) {
12417 		len = 0;
12418 		flags &= ~TH_FIN;
12419 	}
12420 	/*
12421 	 * On TFO sockets, ensure no data is sent in the following cases:
12422 	 *
12423 	 *  - When retransmitting SYN|ACK on a passively-created socket
12424 	 *  - When retransmitting SYN on an actively created socket
12425 	 *  - When sending a zero-length cookie (cookie request) on an
12426 	 *    actively created socket
12427 	 *  - When the socket is in the CLOSED state (RST is being sent)
12428 	 */
12429 	if ((tp->t_flags & TF_FASTOPEN) &&
12430 	    (((flags & TH_SYN) && (tp->t_rxtshift > 0)) ||
12431 	     ((tp->t_state == TCPS_SYN_SENT) &&
12432 	      (tp->t_tfo_client_cookie_len == 0)) ||
12433 	     (flags & TH_RST))) {
12434 		len = 0;
12435 		sack_rxmit = 0;
12436 		rsm = NULL;
12437 	}
12438 	/* Without fast-open there should never be data sent on a SYN */
12439 	if ((flags & TH_SYN) && !(tp->t_flags & TF_FASTOPEN))
12440 		len = 0;
12441 	if (len <= 0) {
12442 		/*
12443 		 * If FIN has been sent but not acked, but we haven't been
12444 		 * called to retransmit, len will be < 0.  Otherwise, window
12445 		 * shrank after we sent into it.  If window shrank to 0,
12446 		 * cancel pending retransmit, pull snd_nxt back to (closed)
12447 		 * window, and set the persist timer if it isn't already
12448 		 * going.  If the window didn't close completely, just wait
12449 		 * for an ACK.
12450 		 *
12451 		 * We also do a general check here to ensure that we will
12452 		 * set the persist timer when we have data to send, but a
12453 		 * 0-byte window. This makes sure the persist timer is set
12454 		 * even if the packet hits one of the "goto send" lines
12455 		 * below.
12456 		 */
12457 		len = 0;
12458 		if ((tp->snd_wnd == 0) &&
12459 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
12460 		    (tp->snd_una == tp->snd_max) &&
12461 		    (sb_offset < (int)sbavail(sb))) {
12462 			/*
12463 			 * Not enough room in the rwnd to send
12464 			 * a paced segment out.
12465 			 */
12466 			bbr_enter_persist(tp, bbr, cts, __LINE__);
12467 		}
12468 	} else if ((rsm == NULL) &&
12469 		   (doing_tlp == 0) &&
12470 		   (len < bbr->r_ctl.rc_pace_max_segs)) {
12471 		/*
12472 		 * We are not sending a full segment for
12473 		 * some reason. Should we not send anything (think
12474 		 * sws or persists)?
12475 		 */
12476 		if ((tp->snd_wnd < min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) &&
12477 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
12478 		    (len < (int)(sbavail(sb) - sb_offset))) {
12479 			/*
12480 			 * Here the rwnd is less than
12481 			 * the pacing size, this is not a retransmit,
12482 			 * we are established and
12483 			 * the send is not the last in the socket buffer
12484 			 * lets not send, and possibly enter persists.
12485 			 */
12486 			len = 0;
12487 			if (tp->snd_max == tp->snd_una)
12488 				bbr_enter_persist(tp, bbr, cts, __LINE__);
12489 		} else if ((tp->snd_cwnd >= bbr->r_ctl.rc_pace_max_segs) &&
12490 			   (ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
12491 						 bbr->r_ctl.rc_lost_bytes)) > (2 * maxseg)) &&
12492 			   (len < (int)(sbavail(sb) - sb_offset)) &&
12493 			   (len < bbr_minseg(bbr))) {
12494 			/*
12495 			 * Here we are not retransmitting, and
12496 			 * the cwnd is not so small that we could
12497 			 * not send at least a min size (rxt timer
12498 			 * not having gone off), We have 2 segments or
12499 			 * more already in flight, its not the tail end
12500 			 * of the socket buffer  and the cwnd is blocking
12501 			 * us from sending out minimum pacing segment size.
12502 			 * Lets not send anything.
12503 			 */
12504 			bbr->rc_cwnd_limited = 1;
12505 			len = 0;
12506 		} else if (((tp->snd_wnd - ctf_outstanding(tp)) <
12507 			    min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) &&
12508 			   (ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
12509 						 bbr->r_ctl.rc_lost_bytes)) > (2 * maxseg)) &&
12510 			   (len < (int)(sbavail(sb) - sb_offset)) &&
12511 			   (TCPS_HAVEESTABLISHED(tp->t_state))) {
12512 			/*
12513 			 * Here we have a send window but we have
12514 			 * filled it up and we can't send another pacing segment.
12515 			 * We also have in flight more than 2 segments
12516 			 * and we are not completing the sb i.e. we allow
12517 			 * the last bytes of the sb to go out even if
12518 			 * its not a full pacing segment.
12519 			 */
12520 			len = 0;
12521 		}
12522 	}
12523 	/* len will be >= 0 after this point. */
12524 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
12525 	tcp_sndbuf_autoscale(tp, so, sendwin);
12526 	/*
12527 	 *
12528 	 */
12529 	if (bbr->rc_in_persist &&
12530 	    len &&
12531 	    (rsm == NULL) &&
12532 	    (len < min((bbr->r_ctl.rc_high_rwnd/2), bbr->r_ctl.rc_pace_max_segs))) {
12533 		/*
12534 		 * We are in persist, not doing a retransmit and don't have enough space
12535 		 * yet to send a full TSO. So is it at the end of the sb
12536 		 * if so we need to send else nuke to 0 and don't send.
12537 		 */
12538 		int sbleft;
12539 		if (sbavail(sb) > sb_offset)
12540 			sbleft = sbavail(sb) - sb_offset;
12541 		else
12542 			sbleft = 0;
12543 		if (sbleft >= min((bbr->r_ctl.rc_high_rwnd/2), bbr->r_ctl.rc_pace_max_segs)) {
12544 			/* not at end of sb lets not send */
12545 			len = 0;
12546 		}
12547 	}
12548 	/*
12549 	 * Decide if we can use TCP Segmentation Offloading (if supported by
12550 	 * hardware).
12551 	 *
12552 	 * TSO may only be used if we are in a pure bulk sending state.  The
12553 	 * presence of TCP-MD5, SACK retransmits, SACK advertizements and IP
12554 	 * options prevent using TSO.  With TSO the TCP header is the same
12555 	 * (except for the sequence number) for all generated packets.  This
12556 	 * makes it impossible to transmit any options which vary per
12557 	 * generated segment or packet.
12558 	 *
12559 	 * IPv4 handling has a clear separation of ip options and ip header
12560 	 * flags while IPv6 combines both in in6p_outputopts. ip6_optlen()
12561 	 * does the right thing below to provide length of just ip options
12562 	 * and thus checking for ipoptlen is enough to decide if ip options
12563 	 * are present.
12564 	 */
12565 #ifdef INET6
12566 	if (isipv6)
12567 		ipoptlen = ip6_optlen(inp);
12568 	else
12569 #endif
12570 	if (inp->inp_options)
12571 		ipoptlen = inp->inp_options->m_len -
12572 		    offsetof(struct ipoption, ipopt_list);
12573 	else
12574 		ipoptlen = 0;
12575 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
12576 	/*
12577 	 * Pre-calculate here as we save another lookup into the darknesses
12578 	 * of IPsec that way and can actually decide if TSO is ok.
12579 	 */
12580 #ifdef INET6
12581 	if (isipv6 && IPSEC_ENABLED(ipv6))
12582 		ipsec_optlen = IPSEC_HDRSIZE(ipv6, inp);
12583 #ifdef INET
12584 	else
12585 #endif
12586 #endif				/* INET6 */
12587 #ifdef INET
12588 	if (IPSEC_ENABLED(ipv4))
12589 		ipsec_optlen = IPSEC_HDRSIZE(ipv4, inp);
12590 #endif				/* INET */
12591 #endif				/* IPSEC */
12592 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
12593 	ipoptlen += ipsec_optlen;
12594 #endif
12595 	if ((tp->t_flags & TF_TSO) && V_tcp_do_tso &&
12596 	    (len > maxseg) &&
12597 	    (tp->t_port == 0) &&
12598 	    ((tp->t_flags & TF_SIGNATURE) == 0) &&
12599 	    ipoptlen == 0)
12600 		tso = 1;
12601 
12602 	recwin = lmin(lmax(sbspace(&so->so_rcv), 0),
12603 	    (long)TCP_MAXWIN << tp->rcv_scale);
12604 	/*
12605 	 * Sender silly window avoidance.   We transmit under the following
12606 	 * conditions when len is non-zero:
12607 	 *
12608 	 * - We have a full segment (or more with TSO) - This is the last
12609 	 * buffer in a write()/send() and we are either idle or running
12610 	 * NODELAY - we've timed out (e.g. persist timer) - we have more
12611 	 * then 1/2 the maximum send window's worth of data (receiver may be
12612 	 * limited the window size) - we need to retransmit
12613 	 */
12614 	if (rsm)
12615 		goto send;
12616 	if (len) {
12617 		if (sack_rxmit)
12618 			goto send;
12619 		if (len >= p_maxseg)
12620 			goto send;
12621 		/*
12622 		 * NOTE! on localhost connections an 'ack' from the remote
12623 		 * end may occur synchronously with the output and cause us
12624 		 * to flush a buffer queued with moretocome.  XXX
12625 		 *
12626 		 */
12627 		if (((tp->t_flags & TF_MORETOCOME) == 0) &&	/* normal case */
12628 		    ((tp->t_flags & TF_NODELAY) ||
12629 		    ((uint32_t)len + (uint32_t)sb_offset) >= sbavail(&so->so_snd)) &&
12630 		    (tp->t_flags & TF_NOPUSH) == 0) {
12631 			goto send;
12632 		}
12633 		if ((tp->snd_una == tp->snd_max) && len) {	/* Nothing outstanding */
12634 			goto send;
12635 		}
12636 		if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0) {
12637 			goto send;
12638 		}
12639 	}
12640 	/*
12641 	 * Sending of standalone window updates.
12642 	 *
12643 	 * Window updates are important when we close our window due to a
12644 	 * full socket buffer and are opening it again after the application
12645 	 * reads data from it.  Once the window has opened again and the
12646 	 * remote end starts to send again the ACK clock takes over and
12647 	 * provides the most current window information.
12648 	 *
12649 	 * We must avoid the silly window syndrome whereas every read from
12650 	 * the receive buffer, no matter how small, causes a window update
12651 	 * to be sent.  We also should avoid sending a flurry of window
12652 	 * updates when the socket buffer had queued a lot of data and the
12653 	 * application is doing small reads.
12654 	 *
12655 	 * Prevent a flurry of pointless window updates by only sending an
12656 	 * update when we can increase the advertized window by more than
12657 	 * 1/4th of the socket buffer capacity.  When the buffer is getting
12658 	 * full or is very small be more aggressive and send an update
12659 	 * whenever we can increase by two mss sized segments. In all other
12660 	 * situations the ACK's to new incoming data will carry further
12661 	 * window increases.
12662 	 *
12663 	 * Don't send an independent window update if a delayed ACK is
12664 	 * pending (it will get piggy-backed on it) or the remote side
12665 	 * already has done a half-close and won't send more data.  Skip
12666 	 * this if the connection is in T/TCP half-open state.
12667 	 */
12668 	if (recwin > 0 && !(tp->t_flags & TF_NEEDSYN) &&
12669 	    !(tp->t_flags & TF_DELACK) &&
12670 	    !TCPS_HAVERCVDFIN(tp->t_state)) {
12671 		/* Check to see if we should do a window update */
12672 		if (bbr_window_update_needed(tp, so, recwin, maxseg))
12673 			goto send;
12674 	}
12675 	/*
12676 	 * Send if we owe the peer an ACK, RST, SYN.  ACKNOW
12677 	 * is also a catch-all for the retransmit timer timeout case.
12678 	 */
12679 	if (tp->t_flags & TF_ACKNOW) {
12680 		goto send;
12681 	}
12682 	if (flags & TH_RST) {
12683 		/* Always send a RST if one is due */
12684 		goto send;
12685 	}
12686 	if ((flags & TH_SYN) && (tp->t_flags & TF_NEEDSYN) == 0) {
12687 		goto send;
12688 	}
12689 	/*
12690 	 * If our state indicates that FIN should be sent and we have not
12691 	 * yet done so, then we need to send.
12692 	 */
12693 	if (flags & TH_FIN &&
12694 	    ((tp->t_flags & TF_SENTFIN) == 0)) {
12695 		goto send;
12696 	}
12697 	/*
12698 	 * No reason to send a segment, just return.
12699 	 */
12700 just_return:
12701 	SOCK_SENDBUF_UNLOCK(so);
12702 just_return_nolock:
12703 	if (tot_len)
12704 		slot = bbr_get_pacing_delay(bbr, bbr->r_ctl.rc_bbr_hptsi_gain, tot_len, cts, 0);
12705 	if (bbr->rc_no_pacing)
12706 		slot = 0;
12707 	if (tot_len == 0) {
12708 		if ((ctf_outstanding(tp) + min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) >=
12709 		    tp->snd_wnd) {
12710 			BBR_STAT_INC(bbr_rwnd_limited);
12711 			app_limited = BBR_JR_RWND_LIMITED;
12712 			bbr_cwnd_limiting(tp, bbr, ctf_outstanding(tp));
12713 			if ((bbr->rc_in_persist == 0) &&
12714 			    TCPS_HAVEESTABLISHED(tp->t_state) &&
12715 			    (tp->snd_max == tp->snd_una) &&
12716 			    sbavail(&so->so_snd)) {
12717 				/* No send window.. we must enter persist */
12718 				bbr_enter_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
12719 			}
12720 		} else if (ctf_outstanding(tp) >= sbavail(sb)) {
12721 			BBR_STAT_INC(bbr_app_limited);
12722 			app_limited = BBR_JR_APP_LIMITED;
12723 			bbr_cwnd_limiting(tp, bbr, ctf_outstanding(tp));
12724 		} else if ((ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
12725 						 bbr->r_ctl.rc_lost_bytes)) + p_maxseg) >= tp->snd_cwnd) {
12726 			BBR_STAT_INC(bbr_cwnd_limited);
12727  			app_limited = BBR_JR_CWND_LIMITED;
12728 			bbr_cwnd_limiting(tp, bbr, ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
12729 									bbr->r_ctl.rc_lost_bytes)));
12730 			bbr->rc_cwnd_limited = 1;
12731 		} else {
12732 			BBR_STAT_INC(bbr_app_limited);
12733 			app_limited = BBR_JR_APP_LIMITED;
12734 			bbr_cwnd_limiting(tp, bbr, ctf_outstanding(tp));
12735 		}
12736 		bbr->r_ctl.rc_hptsi_agg_delay = 0;
12737 		bbr->r_agg_early_set = 0;
12738 		bbr->r_ctl.rc_agg_early = 0;
12739 		bbr->r_ctl.rc_last_delay_val = 0;
12740 	} else if (bbr->rc_use_google == 0)
12741 		bbr_check_bbr_for_state(bbr, cts, __LINE__, 0);
12742 	/* Are we app limited? */
12743 	if ((app_limited == BBR_JR_APP_LIMITED) ||
12744 	    (app_limited == BBR_JR_RWND_LIMITED)) {
12745 		/**
12746 		 * We are application limited.
12747 		 */
12748 		bbr->r_ctl.r_app_limited_until = (ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
12749 								       bbr->r_ctl.rc_lost_bytes)) + bbr->r_ctl.rc_delivered);
12750 	}
12751 	if (tot_len == 0)
12752 		counter_u64_add(bbr_out_size[TCP_MSS_ACCT_JUSTRET], 1);
12753 	/* Dont update the time if we did not send */
12754 	bbr->r_ctl.rc_last_delay_val = 0;
12755 	bbr->rc_output_starts_timer = 1;
12756 	bbr_start_hpts_timer(bbr, tp, cts, 9, slot, tot_len);
12757 	bbr_log_type_just_return(bbr, cts, tot_len, hpts_calling, app_limited, p_maxseg, len);
12758 	if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
12759 		/* Make sure snd_nxt is drug up */
12760 		tp->snd_nxt = tp->snd_max;
12761 	}
12762 	return (error);
12763 
12764 send:
12765 	if (doing_tlp == 0) {
12766 		/*
12767 		 * Data not a TLP, and its not the rxt firing. If it is the
12768 		 * rxt firing, we want to leave the tlp_in_progress flag on
12769 		 * so we don't send another TLP. It has to be a rack timer
12770 		 * or normal send (response to acked data) to clear the tlp
12771 		 * in progress flag.
12772 		 */
12773 		bbr->rc_tlp_in_progress = 0;
12774 		bbr->rc_tlp_rtx_out = 0;
12775 	} else {
12776 		/*
12777 		 * Its a TLP.
12778 		 */
12779 		bbr->rc_tlp_in_progress = 1;
12780 	}
12781 	bbr_timer_cancel(bbr, __LINE__, cts);
12782 	if (rsm == NULL) {
12783 		if (sbused(sb) > 0) {
12784 			/*
12785 			 * This is sub-optimal. We only send a stand alone
12786 			 * FIN on its own segment.
12787 			 */
12788 			if (flags & TH_FIN) {
12789 				flags &= ~TH_FIN;
12790 				if ((len == 0) && ((tp->t_flags & TF_ACKNOW) == 0)) {
12791 					/* Lets not send this */
12792 					slot = 0;
12793 					goto just_return;
12794 				}
12795 			}
12796 		}
12797 	} else {
12798 		/*
12799 		 * We do *not* send a FIN on a retransmit if it has data.
12800 		 * The if clause here where len > 1 should never come true.
12801 		 */
12802 		if ((len > 0) &&
12803 		    (((rsm->r_flags & BBR_HAS_FIN) == 0) &&
12804 		    (flags & TH_FIN))) {
12805 			flags &= ~TH_FIN;
12806 			len--;
12807 		}
12808 	}
12809 	SOCK_SENDBUF_LOCK_ASSERT(so);
12810 	if (len > 0) {
12811 		if ((tp->snd_una == tp->snd_max) &&
12812 		    (bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time) >= bbr_rtt_probe_time)) {
12813 			/*
12814 			 * This qualifies as a RTT_PROBE session since we
12815 			 * drop the data outstanding to nothing and waited
12816 			 * more than bbr_rtt_probe_time.
12817 			 */
12818 			bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_WASIDLE, 0);
12819 			bbr_set_reduced_rtt(bbr, cts, __LINE__);
12820 		}
12821 		if (len >= maxseg)
12822 			tp->t_flags2 |= TF2_PLPMTU_MAXSEGSNT;
12823 		else
12824 			tp->t_flags2 &= ~TF2_PLPMTU_MAXSEGSNT;
12825 	}
12826 	/*
12827 	 * Before ESTABLISHED, force sending of initial options unless TCP
12828 	 * set not to do any options. NOTE: we assume that the IP/TCP header
12829 	 * plus TCP options always fit in a single mbuf, leaving room for a
12830 	 * maximum link header, i.e. max_linkhdr + sizeof (struct tcpiphdr)
12831 	 * + optlen <= MCLBYTES
12832 	 */
12833 	optlen = 0;
12834 #ifdef INET6
12835 	if (isipv6)
12836 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
12837 	else
12838 #endif
12839 		hdrlen = sizeof(struct tcpiphdr);
12840 
12841 	/*
12842 	 * Compute options for segment. We only have to care about SYN and
12843 	 * established connection segments.  Options for SYN-ACK segments
12844 	 * are handled in TCP syncache.
12845 	 */
12846 	to.to_flags = 0;
12847 	local_options = 0;
12848 	if ((tp->t_flags & TF_NOOPT) == 0) {
12849 		/* Maximum segment size. */
12850 		if (flags & TH_SYN) {
12851 			to.to_mss = tcp_mssopt(&inp->inp_inc);
12852 			if (tp->t_port)
12853 				to.to_mss -= V_tcp_udp_tunneling_overhead;
12854 			to.to_flags |= TOF_MSS;
12855 			/*
12856 			 * On SYN or SYN|ACK transmits on TFO connections,
12857 			 * only include the TFO option if it is not a
12858 			 * retransmit, as the presence of the TFO option may
12859 			 * have caused the original SYN or SYN|ACK to have
12860 			 * been dropped by a middlebox.
12861 			 */
12862 			if ((tp->t_flags & TF_FASTOPEN) &&
12863 			    (tp->t_rxtshift == 0)) {
12864 				if (tp->t_state == TCPS_SYN_RECEIVED) {
12865 					to.to_tfo_len = TCP_FASTOPEN_COOKIE_LEN;
12866 					to.to_tfo_cookie =
12867 					    (u_int8_t *)&tp->t_tfo_cookie.server;
12868 					to.to_flags |= TOF_FASTOPEN;
12869 					wanted_cookie = 1;
12870 				} else if (tp->t_state == TCPS_SYN_SENT) {
12871 					to.to_tfo_len =
12872 					    tp->t_tfo_client_cookie_len;
12873 					to.to_tfo_cookie =
12874 					    tp->t_tfo_cookie.client;
12875 					to.to_flags |= TOF_FASTOPEN;
12876 					wanted_cookie = 1;
12877 				}
12878 			}
12879 		}
12880 		/* Window scaling. */
12881 		if ((flags & TH_SYN) && (tp->t_flags & TF_REQ_SCALE)) {
12882 			to.to_wscale = tp->request_r_scale;
12883 			to.to_flags |= TOF_SCALE;
12884 		}
12885 		/* Timestamps. */
12886 		if ((tp->t_flags & TF_RCVD_TSTMP) ||
12887 		    ((flags & TH_SYN) && (tp->t_flags & TF_REQ_TSTMP))) {
12888 			to.to_tsval = 	tcp_tv_to_mssectick(&bbr->rc_tv) + tp->ts_offset;
12889 			to.to_tsecr = tp->ts_recent;
12890 			to.to_flags |= TOF_TS;
12891 			local_options += TCPOLEN_TIMESTAMP + 2;
12892 		}
12893 		/* Set receive buffer autosizing timestamp. */
12894 		if (tp->rfbuf_ts == 0 &&
12895 		    (so->so_rcv.sb_flags & SB_AUTOSIZE))
12896 			tp->rfbuf_ts = 	tcp_tv_to_mssectick(&bbr->rc_tv);
12897 		/* Selective ACK's. */
12898 		if (flags & TH_SYN)
12899 			to.to_flags |= TOF_SACKPERM;
12900 		else if (TCPS_HAVEESTABLISHED(tp->t_state) &&
12901 		    tp->rcv_numsacks > 0) {
12902 			to.to_flags |= TOF_SACK;
12903 			to.to_nsacks = tp->rcv_numsacks;
12904 			to.to_sacks = (u_char *)tp->sackblks;
12905 		}
12906 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
12907 		/* TCP-MD5 (RFC2385). */
12908 		if (tp->t_flags & TF_SIGNATURE)
12909 			to.to_flags |= TOF_SIGNATURE;
12910 #endif				/* TCP_SIGNATURE */
12911 
12912 		/* Processing the options. */
12913 		hdrlen += (optlen = tcp_addoptions(&to, opt));
12914 		/*
12915 		 * If we wanted a TFO option to be added, but it was unable
12916 		 * to fit, ensure no data is sent.
12917 		 */
12918 		if ((tp->t_flags & TF_FASTOPEN) && wanted_cookie &&
12919 		    !(to.to_flags & TOF_FASTOPEN))
12920 			len = 0;
12921 	}
12922 	if (tp->t_port) {
12923 		if (V_tcp_udp_tunneling_port == 0) {
12924 			/* The port was removed?? */
12925 			SOCK_SENDBUF_UNLOCK(so);
12926 			return (EHOSTUNREACH);
12927 		}
12928 		hdrlen += sizeof(struct udphdr);
12929 	}
12930 #ifdef INET6
12931 	if (isipv6)
12932 		ipoptlen = ip6_optlen(inp);
12933 	else
12934 #endif
12935 	if (inp->inp_options)
12936 		ipoptlen = inp->inp_options->m_len -
12937 		    offsetof(struct ipoption, ipopt_list);
12938 	else
12939 		ipoptlen = 0;
12940 	ipoptlen = 0;
12941 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
12942 	ipoptlen += ipsec_optlen;
12943 #endif
12944 	if (bbr->rc_last_options != local_options) {
12945 		/*
12946 		 * Cache the options length this generally does not change
12947 		 * on a connection. We use this to calculate TSO.
12948 		 */
12949 		bbr->rc_last_options = local_options;
12950 	}
12951 	maxseg = tp->t_maxseg - (ipoptlen + optlen);
12952 	p_maxseg = min(maxseg, pace_max_segs);
12953 	/*
12954 	 * Adjust data length if insertion of options will bump the packet
12955 	 * length beyond the t_maxseg length. Clear the FIN bit because we
12956 	 * cut off the tail of the segment.
12957 	 */
12958 	if (len > maxseg) {
12959 		if (len != 0 && (flags & TH_FIN)) {
12960 			flags &= ~TH_FIN;
12961 		}
12962 		if (tso) {
12963 			uint32_t moff;
12964 			int32_t max_len;
12965 
12966 			/* extract TSO information */
12967 			if_hw_tsomax = tp->t_tsomax;
12968 			if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
12969 			if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
12970 			KASSERT(ipoptlen == 0,
12971 			    ("%s: TSO can't do IP options", __func__));
12972 
12973 			/*
12974 			 * Check if we should limit by maximum payload
12975 			 * length:
12976 			 */
12977 			if (if_hw_tsomax != 0) {
12978 				/* compute maximum TSO length */
12979 				max_len = (if_hw_tsomax - hdrlen -
12980 				    max_linkhdr);
12981 				if (max_len <= 0) {
12982 					len = 0;
12983 				} else if (len > max_len) {
12984 					len = max_len;
12985 				}
12986 			}
12987 			/*
12988 			 * Prevent the last segment from being fractional
12989 			 * unless the send sockbuf can be emptied:
12990 			 */
12991 			if ((sb_offset + len) < sbavail(sb)) {
12992 				moff = len % (uint32_t)maxseg;
12993 				if (moff != 0) {
12994 					len -= moff;
12995 				}
12996 			}
12997 			/*
12998 			 * In case there are too many small fragments don't
12999 			 * use TSO:
13000 			 */
13001 			if (len <= maxseg) {
13002 				len = maxseg;
13003 				tso = 0;
13004 			}
13005 		} else {
13006 			/* Not doing TSO */
13007 			if (optlen + ipoptlen >= tp->t_maxseg) {
13008 				/*
13009 				 * Since we don't have enough space to put
13010 				 * the IP header chain and the TCP header in
13011 				 * one packet as required by RFC 7112, don't
13012 				 * send it. Also ensure that at least one
13013 				 * byte of the payload can be put into the
13014 				 * TCP segment.
13015 				 */
13016 				SOCK_SENDBUF_UNLOCK(so);
13017 				error = EMSGSIZE;
13018 				sack_rxmit = 0;
13019 				goto out;
13020 			}
13021 			len = maxseg;
13022 		}
13023 	} else {
13024 		/* Not doing TSO */
13025 		if_hw_tsomaxsegcount = 0;
13026 		tso = 0;
13027 	}
13028 	KASSERT(len + hdrlen + ipoptlen <= IP_MAXPACKET,
13029 	    ("%s: len > IP_MAXPACKET", __func__));
13030 #ifdef DIAGNOSTIC
13031 #ifdef INET6
13032 	if (max_linkhdr + hdrlen > MCLBYTES)
13033 #else
13034 	if (max_linkhdr + hdrlen > MHLEN)
13035 #endif
13036 		panic("tcphdr too big");
13037 #endif
13038 	/*
13039 	 * This KASSERT is here to catch edge cases at a well defined place.
13040 	 * Before, those had triggered (random) panic conditions further
13041 	 * down.
13042 	 */
13043 #ifdef BBR_INVARIANTS
13044 	if (sack_rxmit) {
13045 		if (SEQ_LT(rsm->r_start, tp->snd_una)) {
13046 			panic("RSM:%p TP:%p bbr:%p start:%u is < snd_una:%u",
13047 			    rsm, tp, bbr, rsm->r_start, tp->snd_una);
13048 		}
13049 	}
13050 #endif
13051 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
13052 	if ((len == 0) &&
13053 	    (flags & TH_FIN) &&
13054 	    (sbused(sb))) {
13055 		/*
13056 		 * We have outstanding data, don't send a fin by itself!.
13057 		 */
13058 		slot = 0;
13059 		goto just_return;
13060 	}
13061 	/*
13062 	 * Grab a header mbuf, attaching a copy of data to be transmitted,
13063 	 * and initialize the header from the template for sends on this
13064 	 * connection.
13065 	 */
13066 	if (len) {
13067 		uint32_t moff;
13068 
13069 		/*
13070 		 * We place a limit on sending with hptsi.
13071 		 */
13072 		if ((rsm == NULL) && len > pace_max_segs)
13073 			len = pace_max_segs;
13074 		if (len <= maxseg)
13075 			tso = 0;
13076 #ifdef INET6
13077 		if (MHLEN < hdrlen + max_linkhdr)
13078 			m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
13079 		else
13080 #endif
13081 			m = m_gethdr(M_NOWAIT, MT_DATA);
13082 
13083 		if (m == NULL) {
13084 			BBR_STAT_INC(bbr_failed_mbuf_aloc);
13085 			bbr_log_enobuf_jmp(bbr, len, cts, __LINE__, len, 0, 0);
13086 			SOCK_SENDBUF_UNLOCK(so);
13087 			error = ENOBUFS;
13088 			sack_rxmit = 0;
13089 			goto out;
13090 		}
13091 		m->m_data += max_linkhdr;
13092 		m->m_len = hdrlen;
13093 		/*
13094 		 * Start the m_copy functions from the closest mbuf to the
13095 		 * sb_offset in the socket buffer chain.
13096 		 */
13097 		if ((sb_offset > sbavail(sb)) || ((len + sb_offset) > sbavail(sb))) {
13098 #ifdef BBR_INVARIANTS
13099 			if ((len + sb_offset) > (sbavail(sb) + ((flags & (TH_FIN | TH_SYN)) ? 1 : 0)))
13100 				panic("tp:%p bbr:%p len:%u sb_offset:%u sbavail:%u rsm:%p %u:%u:%u",
13101 				    tp, bbr, len, sb_offset, sbavail(sb), rsm,
13102 				    doing_retran_from,
13103 				    picked_up_retran,
13104 				    doing_tlp);
13105 
13106 #endif
13107 			/*
13108 			 * In this messed up situation we have two choices,
13109 			 * a) pretend the send worked, and just start timers
13110 			 * and what not (not good since that may lead us
13111 			 * back here a lot). <or> b) Send the lowest segment
13112 			 * in the map. <or> c) Drop the connection. Lets do
13113 			 * <b> which if it continues to happen will lead to
13114 			 * <c> via timeouts.
13115 			 */
13116 			BBR_STAT_INC(bbr_offset_recovery);
13117 			rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
13118 			sb_offset = 0;
13119 			if (rsm == NULL) {
13120 				sack_rxmit = 0;
13121 				len = sbavail(sb);
13122 			} else {
13123 				sack_rxmit = 1;
13124 				if (rsm->r_start != tp->snd_una) {
13125 					/*
13126 					 * Things are really messed up, <c>
13127 					 * is the only thing to do.
13128 					 */
13129 					BBR_STAT_INC(bbr_offset_drop);
13130 					SOCK_SENDBUF_UNLOCK(so);
13131 					(void)m_free(m);
13132 					return (-EFAULT); /* tcp_drop() */
13133 				}
13134 				len = rsm->r_end - rsm->r_start;
13135 			}
13136 			if (len > sbavail(sb))
13137 				len = sbavail(sb);
13138 			if (len > maxseg)
13139 				len = maxseg;
13140 		}
13141 		mb = sbsndptr_noadv(sb, sb_offset, &moff);
13142 		if (len <= MHLEN - hdrlen - max_linkhdr && !hw_tls) {
13143 			m_copydata(mb, moff, (int)len,
13144 			    mtod(m, caddr_t)+hdrlen);
13145 			if (rsm == NULL)
13146 				sbsndptr_adv(sb, mb, len);
13147 			m->m_len += len;
13148 		} else {
13149 			struct sockbuf *msb;
13150 
13151 			if (rsm)
13152 				msb = NULL;
13153 			else
13154 				msb = sb;
13155 #ifdef BBR_INVARIANTS
13156 			if ((len + moff) > (sbavail(sb) + ((flags & (TH_FIN | TH_SYN)) ? 1 : 0))) {
13157 				if (rsm) {
13158 					panic("tp:%p bbr:%p len:%u moff:%u sbavail:%u rsm:%p snd_una:%u rsm_start:%u flg:%x %u:%u:%u sr:%d ",
13159 					    tp, bbr, len, moff,
13160 					    sbavail(sb), rsm,
13161 					    tp->snd_una, rsm->r_flags, rsm->r_start,
13162 					    doing_retran_from,
13163 					    picked_up_retran,
13164 					    doing_tlp, sack_rxmit);
13165 				} else {
13166 					panic("tp:%p bbr:%p len:%u moff:%u sbavail:%u sb_offset:%u snd_una:%u",
13167 					    tp, bbr, len, moff, sbavail(sb), sb_offset, tp->snd_una);
13168 				}
13169 			}
13170 #endif
13171 			m->m_next = tcp_m_copym(
13172 				mb, moff, &len,
13173 				if_hw_tsomaxsegcount,
13174 				if_hw_tsomaxsegsize, msb,
13175 				((rsm == NULL) ? hw_tls : 0)
13176 #ifdef NETFLIX_COPY_ARGS
13177 				, NULL, NULL
13178 #endif
13179 				);
13180 			if (len <= maxseg) {
13181 				/*
13182 				 * Must have ran out of mbufs for the copy
13183 				 * shorten it to no longer need tso. Lets
13184 				 * not put on sendalot since we are low on
13185 				 * mbufs.
13186 				 */
13187 				tso = 0;
13188 			}
13189 			if (m->m_next == NULL) {
13190 				SOCK_SENDBUF_UNLOCK(so);
13191 				(void)m_free(m);
13192 				error = ENOBUFS;
13193 				sack_rxmit = 0;
13194 				goto out;
13195 			}
13196 		}
13197 #ifdef BBR_INVARIANTS
13198 		if (tso && len < maxseg) {
13199 			panic("tp:%p tso on, but len:%d < maxseg:%d",
13200 			    tp, len, maxseg);
13201 		}
13202 		if (tso && if_hw_tsomaxsegcount) {
13203 			int32_t seg_cnt = 0;
13204 			struct mbuf *foo;
13205 
13206 			foo = m;
13207 			while (foo) {
13208 				seg_cnt++;
13209 				foo = foo->m_next;
13210 			}
13211 			if (seg_cnt > if_hw_tsomaxsegcount) {
13212 				panic("seg_cnt:%d > max:%d", seg_cnt, if_hw_tsomaxsegcount);
13213 			}
13214 		}
13215 #endif
13216 		/*
13217 		 * If we're sending everything we've got, set PUSH. (This
13218 		 * will keep happy those implementations which only give
13219 		 * data to the user when a buffer fills or a PUSH comes in.)
13220 		 */
13221 		if (sb_offset + len == sbused(sb) &&
13222 		    sbused(sb) &&
13223 		    !(flags & TH_SYN)) {
13224 			flags |= TH_PUSH;
13225 		}
13226 		SOCK_SENDBUF_UNLOCK(so);
13227 	} else {
13228 		SOCK_SENDBUF_UNLOCK(so);
13229 		if (tp->t_flags & TF_ACKNOW)
13230 			KMOD_TCPSTAT_INC(tcps_sndacks);
13231 		else if (flags & (TH_SYN | TH_FIN | TH_RST))
13232 			KMOD_TCPSTAT_INC(tcps_sndctrl);
13233 		else
13234 			KMOD_TCPSTAT_INC(tcps_sndwinup);
13235 
13236 		m = m_gethdr(M_NOWAIT, MT_DATA);
13237 		if (m == NULL) {
13238 			BBR_STAT_INC(bbr_failed_mbuf_aloc);
13239 			bbr_log_enobuf_jmp(bbr, len, cts, __LINE__, len, 0, 0);
13240 			error = ENOBUFS;
13241 			/* Fudge the send time since we could not send */
13242 			sack_rxmit = 0;
13243 			goto out;
13244 		}
13245 #ifdef INET6
13246 		if (isipv6 && (MHLEN < hdrlen + max_linkhdr) &&
13247 		    MHLEN >= hdrlen) {
13248 			M_ALIGN(m, hdrlen);
13249 		} else
13250 #endif
13251 			m->m_data += max_linkhdr;
13252 		m->m_len = hdrlen;
13253 	}
13254 	SOCK_SENDBUF_UNLOCK_ASSERT(so);
13255 	m->m_pkthdr.rcvif = (struct ifnet *)0;
13256 #ifdef MAC
13257 	mac_inpcb_create_mbuf(inp, m);
13258 #endif
13259 #ifdef INET6
13260 	if (isipv6) {
13261 		ip6 = mtod(m, struct ip6_hdr *);
13262 		if (tp->t_port) {
13263 			udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
13264 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
13265 			udp->uh_dport = tp->t_port;
13266 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
13267 			udp->uh_ulen = htons(ulen);
13268 			th = (struct tcphdr *)(udp + 1);
13269 		} else {
13270 			th = (struct tcphdr *)(ip6 + 1);
13271 		}
13272 		tcpip_fillheaders(inp, tp->t_port, ip6, th);
13273 	} else
13274 #endif				/* INET6 */
13275 	{
13276 		ip = mtod(m, struct ip *);
13277 		if (tp->t_port) {
13278 			udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
13279 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
13280 			udp->uh_dport = tp->t_port;
13281 			ulen = hdrlen + len - sizeof(struct ip);
13282 			udp->uh_ulen = htons(ulen);
13283 			th = (struct tcphdr *)(udp + 1);
13284 		} else {
13285 			th = (struct tcphdr *)(ip + 1);
13286 		}
13287 		tcpip_fillheaders(inp, tp->t_port, ip, th);
13288 	}
13289 	/*
13290 	 * If we are doing retransmissions, then snd_nxt will not reflect
13291 	 * the first unsent octet.  For ACK only packets, we do not want the
13292 	 * sequence number of the retransmitted packet, we want the sequence
13293 	 * number of the next unsent octet.  So, if there is no data (and no
13294 	 * SYN or FIN), use snd_max instead of snd_nxt when filling in
13295 	 * ti_seq.  But if we are in persist state, snd_max might reflect
13296 	 * one byte beyond the right edge of the window, so use snd_nxt in
13297 	 * that case, since we know we aren't doing a retransmission.
13298 	 * (retransmit and persist are mutually exclusive...)
13299 	 */
13300 	if (sack_rxmit == 0) {
13301 		if (len && ((flags & (TH_FIN | TH_SYN | TH_RST)) == 0)) {
13302 			/* New data (including new persists) */
13303 			th->th_seq = htonl(tp->snd_max);
13304 			bbr_seq = tp->snd_max;
13305 		} else if (flags & TH_SYN) {
13306 			/* Syn's always send from iss */
13307 			th->th_seq = htonl(tp->iss);
13308 			bbr_seq = tp->iss;
13309 		} else if (flags & TH_FIN) {
13310 			if (flags & TH_FIN && tp->t_flags & TF_SENTFIN) {
13311 				/*
13312 				 * If we sent the fin already its 1 minus
13313 				 * snd_max
13314 				 */
13315 				th->th_seq = (htonl(tp->snd_max - 1));
13316 				bbr_seq = (tp->snd_max - 1);
13317 			} else {
13318 				/* First time FIN use snd_max */
13319 				th->th_seq = htonl(tp->snd_max);
13320 				bbr_seq = tp->snd_max;
13321 			}
13322 		} else {
13323 			/*
13324 			 * len == 0 and not persist we use snd_max, sending
13325 			 * an ack unless we have sent the fin then its 1
13326 			 * minus.
13327 			 */
13328 			/*
13329 			 * XXXRRS Question if we are in persists and we have
13330 			 * nothing outstanding to send and we have not sent
13331 			 * a FIN, we will send an ACK. In such a case it
13332 			 * might be better to send (tp->snd_una - 1) which
13333 			 * would force the peer to ack.
13334 			 */
13335 			if (tp->t_flags & TF_SENTFIN) {
13336 				th->th_seq = htonl(tp->snd_max - 1);
13337 				bbr_seq = (tp->snd_max - 1);
13338 			} else {
13339 				th->th_seq = htonl(tp->snd_max);
13340 				bbr_seq = tp->snd_max;
13341 			}
13342 		}
13343 	} else {
13344 		/* All retransmits use the rsm to guide the send */
13345 		th->th_seq = htonl(rsm->r_start);
13346 		bbr_seq = rsm->r_start;
13347 	}
13348 	th->th_ack = htonl(tp->rcv_nxt);
13349 	if (optlen) {
13350 		bcopy(opt, th + 1, optlen);
13351 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
13352 	}
13353 	tcp_set_flags(th, flags);
13354 	/*
13355 	 * Calculate receive window.  Don't shrink window, but avoid silly
13356 	 * window syndrome.
13357 	 */
13358 	if ((flags & TH_RST) || ((recwin < (so->so_rcv.sb_hiwat / 4) &&
13359 				  recwin < maxseg)))
13360 		recwin = 0;
13361 	if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) &&
13362 	    recwin < (tp->rcv_adv - tp->rcv_nxt))
13363 		recwin = (tp->rcv_adv - tp->rcv_nxt);
13364 	if (recwin > TCP_MAXWIN << tp->rcv_scale)
13365 		recwin = TCP_MAXWIN << tp->rcv_scale;
13366 
13367 	/*
13368 	 * According to RFC1323 the window field in a SYN (i.e., a <SYN> or
13369 	 * <SYN,ACK>) segment itself is never scaled.  The <SYN,ACK> case is
13370 	 * handled in syncache.
13371 	 */
13372 	if (flags & TH_SYN)
13373 		th->th_win = htons((u_short)
13374 		    (min(sbspace(&so->so_rcv), TCP_MAXWIN)));
13375 	else {
13376 		/* Avoid shrinking window with window scaling. */
13377 		recwin = roundup2(recwin, 1 << tp->rcv_scale);
13378 		th->th_win = htons((u_short)(recwin >> tp->rcv_scale));
13379 	}
13380 	/*
13381 	 * Adjust the RXWIN0SENT flag - indicate that we have advertised a 0
13382 	 * window.  This may cause the remote transmitter to stall.  This
13383 	 * flag tells soreceive() to disable delayed acknowledgements when
13384 	 * draining the buffer.  This can occur if the receiver is
13385 	 * attempting to read more data than can be buffered prior to
13386 	 * transmitting on the connection.
13387 	 */
13388 	if (th->th_win == 0) {
13389 		tp->t_sndzerowin++;
13390 		tp->t_flags |= TF_RXWIN0SENT;
13391 	} else
13392 		tp->t_flags &= ~TF_RXWIN0SENT;
13393 	/*
13394 	 * We don't support urgent data, but drag along
13395 	 * the pointer in case of a stack switch.
13396 	 */
13397 	tp->snd_up = tp->snd_una;
13398 	/*
13399 	 * Put TCP length in extended header, and then checksum extended
13400 	 * header and data.
13401 	 */
13402 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
13403 
13404 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
13405 	if (to.to_flags & TOF_SIGNATURE) {
13406 		/*
13407 		 * Calculate MD5 signature and put it into the place
13408 		 * determined before. NOTE: since TCP options buffer doesn't
13409 		 * point into mbuf's data, calculate offset and use it.
13410 		 */
13411 		if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
13412 		    (u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
13413 			/*
13414 			 * Do not send segment if the calculation of MD5
13415 			 * digest has failed.
13416 			 */
13417 			goto out;
13418 		}
13419 	}
13420 #endif
13421 
13422 #ifdef INET6
13423 	if (isipv6) {
13424 		/*
13425 		 * ip6_plen is not need to be filled now, and will be filled
13426 		 * in ip6_output.
13427 		 */
13428 		if (tp->t_port) {
13429 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
13430 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
13431 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
13432 			th->th_sum = htons(0);
13433 			UDPSTAT_INC(udps_opackets);
13434 		} else {
13435 			csum_flags = m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
13436 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
13437 			th->th_sum = in6_cksum_pseudo(ip6, sizeof(struct tcphdr) +
13438 			    optlen + len, IPPROTO_TCP, 0);
13439 		}
13440 	}
13441 #endif
13442 #if defined(INET6) && defined(INET)
13443 	else
13444 #endif
13445 #ifdef INET
13446 	{
13447 		if (tp->t_port) {
13448 			m->m_pkthdr.csum_flags = CSUM_UDP;
13449 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
13450 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
13451 			    ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
13452 			th->th_sum = htons(0);
13453 			UDPSTAT_INC(udps_opackets);
13454 		} else {
13455 			csum_flags = m->m_pkthdr.csum_flags = CSUM_TCP;
13456 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
13457 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
13458 			    ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
13459 			    IPPROTO_TCP + len + optlen));
13460 		}
13461 		/* IP version must be set here for ipv4/ipv6 checking later */
13462 		KASSERT(ip->ip_v == IPVERSION,
13463 		    ("%s: IP version incorrect: %d", __func__, ip->ip_v));
13464 	}
13465 #endif
13466 
13467 	/*
13468 	 * Enable TSO and specify the size of the segments. The TCP pseudo
13469 	 * header checksum is always provided. XXX: Fixme: This is currently
13470 	 * not the case for IPv6.
13471 	 */
13472 	if (tso) {
13473 		KASSERT(len > maxseg,
13474 		    ("%s: len:%d <= tso_segsz:%d", __func__, len, maxseg));
13475 		m->m_pkthdr.csum_flags |= CSUM_TSO;
13476 		csum_flags |= CSUM_TSO;
13477 		m->m_pkthdr.tso_segsz = maxseg;
13478 	}
13479 	KASSERT(len + hdrlen == m_length(m, NULL),
13480 	    ("%s: mbuf chain different than expected: %d + %u != %u",
13481 	    __func__, len, hdrlen, m_length(m, NULL)));
13482 
13483 #ifdef TCP_HHOOK
13484 	/* Run HHOOK_TC_ESTABLISHED_OUT helper hooks. */
13485 	hhook_run_tcp_est_out(tp, th, &to, len, tso);
13486 #endif
13487 
13488 	/* Log to the black box */
13489 	if (tcp_bblogging_on(tp)) {
13490 		union tcp_log_stackspecific log;
13491 
13492 		bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
13493 		/* Record info on type of transmission */
13494 		log.u_bbr.flex1 = bbr->r_ctl.rc_hptsi_agg_delay;
13495 		log.u_bbr.flex2 = (bbr->r_recovery_bw << 3);
13496 		log.u_bbr.flex3 = maxseg;
13497 		log.u_bbr.flex4 = delay_calc;
13498 		log.u_bbr.flex5 = bbr->rc_past_init_win;
13499 		log.u_bbr.flex5 <<= 1;
13500 		log.u_bbr.flex5 |= bbr->rc_no_pacing;
13501 		log.u_bbr.flex5 <<= 29;
13502 		log.u_bbr.flex5 |= tp->t_maxseg;
13503 		log.u_bbr.flex6 = bbr->r_ctl.rc_pace_max_segs;
13504 		log.u_bbr.flex7 = (bbr->rc_bbr_state << 8) | bbr_state_val(bbr);
13505 		/* lets poke in the low and the high here for debugging */
13506 		log.u_bbr.pkts_out = bbr->rc_tp->t_maxseg;
13507 		if (rsm || sack_rxmit) {
13508 			if (doing_tlp)
13509 				log.u_bbr.flex8 = 2;
13510 			else
13511 				log.u_bbr.flex8 = 1;
13512 		} else {
13513 			log.u_bbr.flex8 = 0;
13514 		}
13515 		lgb = tcp_log_event(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_OUT, ERRNO_UNK,
13516 		    len, &log, false, NULL, NULL, 0, tv);
13517 	} else {
13518 		lgb = NULL;
13519 	}
13520 	/*
13521 	 * Fill in IP length and desired time to live and send to IP level.
13522 	 * There should be a better way to handle ttl and tos; we could keep
13523 	 * them in the template, but need a way to checksum without them.
13524 	 */
13525 	/*
13526 	 * m->m_pkthdr.len should have been set before cksum calcuration,
13527 	 * because in6_cksum() need it.
13528 	 */
13529 #ifdef INET6
13530 	if (isipv6) {
13531 		/*
13532 		 * we separately set hoplimit for every segment, since the
13533 		 * user might want to change the value via setsockopt. Also,
13534 		 * desired default hop limit might be changed via Neighbor
13535 		 * Discovery.
13536 		 */
13537 		ip6->ip6_hlim = in6_selecthlim(inp, NULL);
13538 
13539 		/*
13540 		 * Set the packet size here for the benefit of DTrace
13541 		 * probes. ip6_output() will set it properly; it's supposed
13542 		 * to include the option header lengths as well.
13543 		 */
13544 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
13545 
13546 		if (V_path_mtu_discovery && maxseg > V_tcp_minmss)
13547 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
13548 		else
13549 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
13550 
13551 		if (tp->t_state == TCPS_SYN_SENT)
13552 			TCP_PROBE5(connect__request, NULL, tp, ip6, tp, th);
13553 
13554 		TCP_PROBE5(send, NULL, tp, ip6, tp, th);
13555 		/* TODO: IPv6 IP6TOS_ECT bit on */
13556 		error = ip6_output(m, inp->in6p_outputopts,
13557 		    &inp->inp_route6,
13558 		    ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0),
13559 		    NULL, NULL, inp);
13560 
13561 		if (error == EMSGSIZE && inp->inp_route6.ro_nh != NULL)
13562 			mtu = inp->inp_route6.ro_nh->nh_mtu;
13563 	}
13564 #endif				/* INET6 */
13565 #if defined(INET) && defined(INET6)
13566 	else
13567 #endif
13568 #ifdef INET
13569 	{
13570 		ip->ip_len = htons(m->m_pkthdr.len);
13571 #ifdef INET6
13572 		if (isipv6)
13573 			ip->ip_ttl = in6_selecthlim(inp, NULL);
13574 #endif				/* INET6 */
13575 		/*
13576 		 * If we do path MTU discovery, then we set DF on every
13577 		 * packet. This might not be the best thing to do according
13578 		 * to RFC3390 Section 2. However the tcp hostcache migitates
13579 		 * the problem so it affects only the first tcp connection
13580 		 * with a host.
13581 		 *
13582 		 * NB: Don't set DF on small MTU/MSS to have a safe
13583 		 * fallback.
13584 		 */
13585 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
13586 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
13587 			if (tp->t_port == 0 || len < V_tcp_minmss) {
13588 				ip->ip_off |= htons(IP_DF);
13589 			}
13590 		} else {
13591 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
13592 		}
13593 
13594 		if (tp->t_state == TCPS_SYN_SENT)
13595 			TCP_PROBE5(connect__request, NULL, tp, ip, tp, th);
13596 
13597 		TCP_PROBE5(send, NULL, tp, ip, tp, th);
13598 
13599 		error = ip_output(m, inp->inp_options, &inp->inp_route,
13600 		    ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0), 0,
13601 		    inp);
13602 		if (error == EMSGSIZE && inp->inp_route.ro_nh != NULL)
13603 			mtu = inp->inp_route.ro_nh->nh_mtu;
13604 	}
13605 #endif				/* INET */
13606 	if (lgb) {
13607 		lgb->tlb_errno = error;
13608 		lgb = NULL;
13609 	}
13610 
13611 out:
13612 	/*
13613 	 * In transmit state, time the transmission and arrange for the
13614 	 * retransmit.  In persist state, just set snd_max.
13615 	 */
13616 	if (error == 0) {
13617 		tcp_account_for_send(tp, len, (rsm != NULL), doing_tlp, hw_tls);
13618 		if (TCPS_HAVEESTABLISHED(tp->t_state) &&
13619 		    (tp->t_flags & TF_SACK_PERMIT) &&
13620 		    tp->rcv_numsacks > 0)
13621 			tcp_clean_dsack_blocks(tp);
13622 		/* We sent an ack clear the bbr_segs_rcvd count */
13623 		bbr->output_error_seen = 0;
13624 		bbr->oerror_cnt = 0;
13625 		bbr->bbr_segs_rcvd = 0;
13626 		if (len == 0)
13627 			counter_u64_add(bbr_out_size[TCP_MSS_ACCT_SNDACK], 1);
13628 		/* Do accounting for new sends */
13629 		if ((len > 0) && (rsm == NULL)) {
13630 			int idx;
13631 			if (tp->snd_una == tp->snd_max) {
13632 				/*
13633 				 * Special case to match google, when
13634 				 * nothing is in flight the delivered
13635 				 * time does get updated to the current
13636 				 * time (see tcp_rate_bsd.c).
13637 				 */
13638 				bbr->r_ctl.rc_del_time = cts;
13639 			}
13640 			if (len >= maxseg) {
13641 				idx = (len / maxseg) + 3;
13642 				if (idx >= TCP_MSS_ACCT_ATIMER)
13643 					counter_u64_add(bbr_out_size[(TCP_MSS_ACCT_ATIMER - 1)], 1);
13644 				else
13645 					counter_u64_add(bbr_out_size[idx], 1);
13646 			} else {
13647 				/* smaller than a MSS */
13648 				idx = len / (bbr_hptsi_bytes_min - bbr->rc_last_options);
13649 				if (idx >= TCP_MSS_SMALL_MAX_SIZE_DIV)
13650 					idx = (TCP_MSS_SMALL_MAX_SIZE_DIV - 1);
13651 				counter_u64_add(bbr_out_size[(idx + TCP_MSS_SMALL_SIZE_OFF)], 1);
13652 			}
13653 		}
13654 	}
13655 	abandon = 0;
13656 	/*
13657 	 * We must do the send accounting before we log the output,
13658 	 * otherwise the state of the rsm could change and we account to the
13659 	 * wrong bucket.
13660 	 */
13661 	if (len > 0) {
13662 		bbr_do_send_accounting(tp, bbr, rsm, len, error);
13663 		if (error == 0) {
13664 			if (tp->snd_una == tp->snd_max)
13665 				bbr->r_ctl.rc_tlp_rxt_last_time = cts;
13666 		}
13667 	}
13668 	bbr_log_output(bbr, tp, &to, len, bbr_seq, (uint8_t) flags, error,
13669 	    cts, mb, &abandon, rsm, 0, sb);
13670 	if (abandon) {
13671 		/*
13672 		 * If bbr_log_output destroys the TCB or sees a TH_RST being
13673 		 * sent we should hit this condition.
13674 		 */
13675 		return (0);
13676 	}
13677 	if (bbr->rc_in_persist == 0) {
13678 		/*
13679 		 * Advance snd_nxt over sequence space of this segment.
13680 		 */
13681 		if (error)
13682 			/* We don't log or do anything with errors */
13683 			goto skip_upd;
13684 
13685 		if (tp->snd_una == tp->snd_max &&
13686 		    (len || (flags & (TH_SYN | TH_FIN)))) {
13687 			/*
13688 			 * Update the time we just added data since none was
13689 			 * outstanding.
13690 			 */
13691 			bbr_log_progress_event(bbr, tp, ticks, PROGRESS_START, __LINE__);
13692 			bbr->rc_tp->t_acktime  = ticks;
13693 		}
13694 		if (flags & (TH_SYN | TH_FIN) && (rsm == NULL)) {
13695 			if (flags & TH_SYN) {
13696 				/*
13697 				 * Smack the snd_max to iss + 1
13698 				 * if its a FO we will add len below.
13699 				 */
13700 				tp->snd_max = tp->iss + 1;
13701 			}
13702 			if ((flags & TH_FIN) && ((tp->t_flags & TF_SENTFIN) == 0)) {
13703 				tp->snd_max++;
13704 				tp->t_flags |= TF_SENTFIN;
13705 			}
13706 		}
13707 		if (sack_rxmit == 0)
13708 			tp->snd_max += len;
13709 skip_upd:
13710 		if ((error == 0) && len)
13711 			tot_len += len;
13712 	} else {
13713 		/* Persists case */
13714 		int32_t xlen = len;
13715 
13716 		if (error)
13717 			goto nomore;
13718 
13719 		if (flags & TH_SYN)
13720 			++xlen;
13721 		if ((flags & TH_FIN) && ((tp->t_flags & TF_SENTFIN) == 0)) {
13722 			++xlen;
13723 			tp->t_flags |= TF_SENTFIN;
13724 		}
13725 		if (xlen && (tp->snd_una == tp->snd_max)) {
13726 			/*
13727 			 * Update the time we just added data since none was
13728 			 * outstanding.
13729 			 */
13730 			bbr_log_progress_event(bbr, tp, ticks, PROGRESS_START, __LINE__);
13731 			bbr->rc_tp->t_acktime = ticks;
13732 		}
13733 		if (sack_rxmit == 0)
13734 			tp->snd_max += xlen;
13735 		tot_len += (len + optlen + ipoptlen);
13736 	}
13737 nomore:
13738 	if (error) {
13739 		/*
13740 		 * Failures do not advance the seq counter above. For the
13741 		 * case of ENOBUFS we will fall out and become ack-clocked.
13742 		 * capping the cwnd at the current flight.
13743 		 * Everything else will just have to retransmit with the timer
13744 		 * (no pacer).
13745 		 */
13746 		SOCK_SENDBUF_UNLOCK_ASSERT(so);
13747 		BBR_STAT_INC(bbr_saw_oerr);
13748 		/* Clear all delay/early tracks */
13749 		bbr->r_ctl.rc_hptsi_agg_delay = 0;
13750 		bbr->r_ctl.rc_agg_early = 0;
13751 		bbr->r_agg_early_set = 0;
13752 		bbr->output_error_seen = 1;
13753 		if (bbr->oerror_cnt < 0xf)
13754 			bbr->oerror_cnt++;
13755 		if (bbr_max_net_error_cnt && (bbr->oerror_cnt >= bbr_max_net_error_cnt)) {
13756 			/* drop the session */
13757 			return (-ENETDOWN);
13758 		}
13759 		switch (error) {
13760 		case ENOBUFS:
13761 			/*
13762 			 * Make this guy have to get ack's to send
13763 			 * more but lets make sure we don't
13764 			 * slam him below a T-O (1MSS).
13765 			 */
13766 			if (bbr->rc_bbr_state != BBR_STATE_PROBE_RTT) {
13767 				tp->snd_cwnd = ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
13768 								    bbr->r_ctl.rc_lost_bytes)) - maxseg;
13769 				if (tp->snd_cwnd < maxseg)
13770 					tp->snd_cwnd = maxseg;
13771 			}
13772 			slot = (bbr_error_base_paceout + 1) << bbr->oerror_cnt;
13773 			BBR_STAT_INC(bbr_saw_enobuf);
13774 			if (bbr->bbr_hdrw_pacing)
13775 				counter_u64_add(bbr_hdwr_pacing_enobuf, 1);
13776 			else
13777 				counter_u64_add(bbr_nohdwr_pacing_enobuf, 1);
13778 			/*
13779 			 * Here even in the enobuf's case we want to do our
13780 			 * state update. The reason being we may have been
13781 			 * called by the input function. If so we have had
13782 			 * things change.
13783 			 */
13784 			error = 0;
13785 			goto enobufs;
13786 		case EMSGSIZE:
13787 			/*
13788 			 * For some reason the interface we used initially
13789 			 * to send segments changed to another or lowered
13790 			 * its MTU. If TSO was active we either got an
13791 			 * interface without TSO capabilits or TSO was
13792 			 * turned off. If we obtained mtu from ip_output()
13793 			 * then update it and try again.
13794 			 */
13795 			/* Turn on tracing (or try to) */
13796 			{
13797 				int old_maxseg;
13798 
13799 				old_maxseg = tp->t_maxseg;
13800 				BBR_STAT_INC(bbr_saw_emsgsiz);
13801 				bbr_log_msgsize_fail(bbr, tp, len, maxseg, mtu, csum_flags, tso, cts);
13802 				if (mtu != 0)
13803 					tcp_mss_update(tp, -1, mtu, NULL, NULL);
13804 				if (old_maxseg <= tp->t_maxseg) {
13805 					/* Huh it did not shrink? */
13806 					tp->t_maxseg = old_maxseg - 40;
13807 					if (tp->t_maxseg < V_tcp_mssdflt) {
13808 						/*
13809 						 * The MSS is so small we should not
13810 						 * process incoming SACK's since we are
13811 						 * subject to attack in such a case.
13812 						 */
13813 						tp->t_flags2 |= TF2_PROC_SACK_PROHIBIT;
13814 					} else {
13815 						tp->t_flags2 &= ~TF2_PROC_SACK_PROHIBIT;
13816 					}
13817 					bbr_log_msgsize_fail(bbr, tp, len, maxseg, mtu, 0, tso, cts);
13818 				}
13819 				/*
13820 				 * Nuke all other things that can interfere
13821 				 * with slot
13822 				 */
13823 				if ((tot_len + len) && (len >= tp->t_maxseg)) {
13824 					slot = bbr_get_pacing_delay(bbr,
13825 					    bbr->r_ctl.rc_bbr_hptsi_gain,
13826 					    (tot_len + len), cts, 0);
13827 					if (slot < bbr_error_base_paceout)
13828 						slot = (bbr_error_base_paceout + 2) << bbr->oerror_cnt;
13829 				} else
13830 					slot = (bbr_error_base_paceout + 2) << bbr->oerror_cnt;
13831 				bbr->rc_output_starts_timer = 1;
13832 				bbr_start_hpts_timer(bbr, tp, cts, 10, slot,
13833 				    tot_len);
13834 				return (error);
13835 			}
13836 		case EPERM:
13837 		case EACCES:
13838 			tp->t_softerror = error;
13839 			/* FALLTHROUGH */
13840 		case EHOSTDOWN:
13841 		case EHOSTUNREACH:
13842 		case ENETDOWN:
13843 		case ENETUNREACH:
13844 			if (TCPS_HAVERCVDSYN(tp->t_state)) {
13845 				tp->t_softerror = error;
13846 				error = 0;
13847 			}
13848 			/* FALLTHROUGH */
13849 		default:
13850 			slot = (bbr_error_base_paceout + 3) << bbr->oerror_cnt;
13851 			bbr->rc_output_starts_timer = 1;
13852 			bbr_start_hpts_timer(bbr, tp, cts, 11, slot, 0);
13853 			return (error);
13854 		}
13855 #ifdef STATS
13856 	} else if (((tp->t_flags & TF_GPUTINPROG) == 0) &&
13857 		    len &&
13858 		    (rsm == NULL) &&
13859 	    (bbr->rc_in_persist == 0)) {
13860 		tp->gput_seq = bbr_seq;
13861 		tp->gput_ack = bbr_seq +
13862 		    min(sbavail(&so->so_snd) - sb_offset, sendwin);
13863 		tp->gput_ts = cts;
13864 		tp->t_flags |= TF_GPUTINPROG;
13865 #endif
13866 	}
13867 	KMOD_TCPSTAT_INC(tcps_sndtotal);
13868 	if ((bbr->bbr_hdw_pace_ena) &&
13869 	    (bbr->bbr_attempt_hdwr_pace == 0) &&
13870 	    (bbr->rc_past_init_win) &&
13871 	    (bbr->rc_bbr_state != BBR_STATE_STARTUP) &&
13872 	    (get_filter_value(&bbr->r_ctl.rc_delrate)) &&
13873 	    (inp->inp_route.ro_nh &&
13874 	     inp->inp_route.ro_nh->nh_ifp)) {
13875 		/*
13876 		 * We are past the initial window and
13877 		 * have at least one measurement so we
13878 		 * could use hardware pacing if its available.
13879 		 * We have an interface and we have not attempted
13880 		 * to setup hardware pacing, lets try to now.
13881 		 */
13882 		uint64_t rate_wanted;
13883 		int err = 0;
13884 
13885 		rate_wanted = bbr_get_hardware_rate(bbr);
13886 		bbr->bbr_attempt_hdwr_pace = 1;
13887 		bbr->r_ctl.crte = tcp_set_pacing_rate(bbr->rc_tp,
13888 						      inp->inp_route.ro_nh->nh_ifp,
13889 						      rate_wanted,
13890 						      (RS_PACING_GEQ|RS_PACING_SUB_OK),
13891 						      &err, NULL);
13892 		if (bbr->r_ctl.crte) {
13893 			bbr_type_log_hdwr_pacing(bbr,
13894 						 bbr->r_ctl.crte->ptbl->rs_ifp,
13895 						 rate_wanted,
13896 						 bbr->r_ctl.crte->rate,
13897 						 __LINE__, cts, err);
13898 			BBR_STAT_INC(bbr_hdwr_rl_add_ok);
13899 			counter_u64_add(bbr_flows_nohdwr_pacing, -1);
13900 			counter_u64_add(bbr_flows_whdwr_pacing, 1);
13901 			bbr->bbr_hdrw_pacing = 1;
13902 			/* Now what is our gain status? */
13903 			if (bbr->r_ctl.crte->rate < rate_wanted) {
13904 				/* We have a problem */
13905 				bbr_setup_less_of_rate(bbr, cts,
13906 						       bbr->r_ctl.crte->rate, rate_wanted);
13907 			} else {
13908 				/* We are good */
13909 				bbr->gain_is_limited = 0;
13910 				bbr->skip_gain = 0;
13911 			}
13912 			tcp_bbr_tso_size_check(bbr, cts);
13913 		} else {
13914 			bbr_type_log_hdwr_pacing(bbr,
13915 						 inp->inp_route.ro_nh->nh_ifp,
13916 						 rate_wanted,
13917 						 0,
13918 						 __LINE__, cts, err);
13919 			BBR_STAT_INC(bbr_hdwr_rl_add_fail);
13920 		}
13921 	}
13922 	if (bbr->bbr_hdrw_pacing) {
13923 		/*
13924 		 * Worry about cases where the route
13925 		 * changes or something happened that we
13926 		 * lost our hardware pacing possibly during
13927 		 * the last ip_output call.
13928 		 */
13929 		if (inp->inp_snd_tag == NULL) {
13930 			/* A change during ip output disabled hw pacing? */
13931 			bbr->bbr_hdrw_pacing = 0;
13932 		} else if ((inp->inp_route.ro_nh == NULL) ||
13933 		    (inp->inp_route.ro_nh->nh_ifp != inp->inp_snd_tag->ifp)) {
13934 			/*
13935 			 * We had an interface or route change,
13936 			 * detach from the current hdwr pacing
13937 			 * and setup to re-attempt next go
13938 			 * round.
13939 			 */
13940 			bbr->bbr_hdrw_pacing = 0;
13941 			bbr->bbr_attempt_hdwr_pace = 0;
13942 			tcp_rel_pacing_rate(bbr->r_ctl.crte, bbr->rc_tp);
13943 			tcp_bbr_tso_size_check(bbr, cts);
13944 		}
13945 	}
13946 	/*
13947 	 * Data sent (as far as we can tell). If this advertises a larger
13948 	 * window than any other segment, then remember the size of the
13949 	 * advertised window. Any pending ACK has now been sent.
13950 	 */
13951 	if (SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv))
13952 		tp->rcv_adv = tp->rcv_nxt + recwin;
13953 
13954 	tp->last_ack_sent = tp->rcv_nxt;
13955 	if ((error == 0) &&
13956 	    (bbr->r_ctl.rc_pace_max_segs > tp->t_maxseg) &&
13957 	    (doing_tlp == 0) &&
13958 	    (tso == 0) &&
13959 	    (len > 0) &&
13960 	    ((flags & TH_RST) == 0) &&
13961 	    ((flags & TH_SYN) == 0) &&
13962 	    (IN_RECOVERY(tp->t_flags) == 0) &&
13963 	    (bbr->rc_in_persist == 0) &&
13964 	    (tot_len < bbr->r_ctl.rc_pace_max_segs)) {
13965 		/*
13966 		 * For non-tso we need to goto again until we have sent out
13967 		 * enough data to match what we are hptsi out every hptsi
13968 		 * interval.
13969 		 */
13970 		if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
13971 			/* Make sure snd_nxt is drug up */
13972 			tp->snd_nxt = tp->snd_max;
13973 		}
13974 		if (rsm != NULL) {
13975 			rsm = NULL;
13976 			goto skip_again;
13977 		}
13978 		rsm = NULL;
13979 		sack_rxmit = 0;
13980 		tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
13981 		goto again;
13982 	}
13983 skip_again:
13984 	if ((error == 0) && (flags & TH_FIN))
13985 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_FIN);
13986 	if ((error == 0) && (flags & TH_RST))
13987 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
13988 	if (((flags & (TH_RST | TH_SYN | TH_FIN)) == 0) && tot_len) {
13989 		/*
13990 		 * Calculate/Re-Calculate the hptsi slot in usecs based on
13991 		 * what we have sent so far
13992 		 */
13993 		slot = bbr_get_pacing_delay(bbr, bbr->r_ctl.rc_bbr_hptsi_gain, tot_len, cts, 0);
13994 		if (bbr->rc_no_pacing)
13995 			slot = 0;
13996 	}
13997 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
13998 enobufs:
13999 	if (bbr->rc_use_google == 0)
14000 		bbr_check_bbr_for_state(bbr, cts, __LINE__, 0);
14001 	bbr_cwnd_limiting(tp, bbr, ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
14002 							bbr->r_ctl.rc_lost_bytes)));
14003 	bbr->rc_output_starts_timer = 1;
14004 	if (bbr->bbr_use_rack_cheat &&
14005 	    (more_to_rxt ||
14006 	     ((bbr->r_ctl.rc_resend = bbr_check_recovery_mode(tp, bbr, cts)) != NULL))) {
14007 		/* Rack cheats and shotguns out all rxt's 1ms apart */
14008 		if (slot > 1000)
14009 			slot = 1000;
14010 	}
14011 	if (bbr->bbr_hdrw_pacing && (bbr->hw_pacing_set == 0)) {
14012 		/*
14013 		 * We don't change the tso size until some number of sends
14014 		 * to give the hardware commands time to get down
14015 		 * to the interface.
14016 		 */
14017 		bbr->r_ctl.bbr_hdwr_cnt_noset_snt++;
14018 		if (bbr->r_ctl.bbr_hdwr_cnt_noset_snt >= bbr_hdwr_pacing_delay_cnt) {
14019 			bbr->hw_pacing_set = 1;
14020 			tcp_bbr_tso_size_check(bbr, cts);
14021 		}
14022 	}
14023 	bbr_start_hpts_timer(bbr, tp, cts, 12, slot, tot_len);
14024 	if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
14025 		/* Make sure snd_nxt is drug up */
14026 		tp->snd_nxt = tp->snd_max;
14027 	}
14028 	return (error);
14029 
14030 }
14031 
14032 /*
14033  * See bbr_output_wtime() for return values.
14034  */
14035 static int
14036 bbr_output(struct tcpcb *tp)
14037 {
14038 	int32_t ret;
14039 	struct timeval tv;
14040 
14041 	NET_EPOCH_ASSERT();
14042 
14043 	INP_WLOCK_ASSERT(tptoinpcb(tp));
14044 	(void)tcp_get_usecs(&tv);
14045 	ret = bbr_output_wtime(tp, &tv);
14046 	return (ret);
14047 }
14048 
14049 static void
14050 bbr_mtu_chg(struct tcpcb *tp)
14051 {
14052 	struct tcp_bbr *bbr;
14053 	struct bbr_sendmap *rsm, *frsm = NULL;
14054 	uint32_t maxseg;
14055 
14056 	/*
14057 	 * The MTU has changed. a) Clear the sack filter. b) Mark everything
14058 	 * over the current size as SACK_PASS so a retransmit will occur.
14059 	 */
14060 
14061 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
14062 	maxseg = tp->t_maxseg - bbr->rc_last_options;
14063 	sack_filter_clear(&bbr->r_ctl.bbr_sf, tp->snd_una);
14064 	TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_map, r_next) {
14065 		/* Don't mess with ones acked (by sack?) */
14066 		if (rsm->r_flags & BBR_ACKED)
14067 			continue;
14068 		if ((rsm->r_end - rsm->r_start) > maxseg) {
14069 			/*
14070 			 * We mark sack-passed on all the previous large
14071 			 * sends we did. This will force them to retransmit.
14072 			 */
14073 			rsm->r_flags |= BBR_SACK_PASSED;
14074 			if (((rsm->r_flags & BBR_MARKED_LOST) == 0) &&
14075 			    bbr_is_lost(bbr, rsm, bbr->r_ctl.rc_rcvtime)) {
14076 				bbr->r_ctl.rc_lost_bytes += rsm->r_end - rsm->r_start;
14077 				bbr->r_ctl.rc_lost += rsm->r_end - rsm->r_start;
14078 				rsm->r_flags |= BBR_MARKED_LOST;
14079 			}
14080 			if (frsm == NULL)
14081 				frsm = rsm;
14082 		}
14083 	}
14084 	if (frsm) {
14085 		bbr->r_ctl.rc_resend = frsm;
14086 	}
14087 }
14088 
14089 static int
14090 bbr_pru_options(struct tcpcb *tp, int flags)
14091 {
14092 	if (flags & PRUS_OOB)
14093 		return (EOPNOTSUPP);
14094 	return (0);
14095 }
14096 
14097 static void
14098 bbr_switch_failed(struct tcpcb *tp)
14099 {
14100 	/*
14101 	 * If a switch fails we only need to
14102 	 * make sure mbuf_queuing is still in place.
14103 	 * We also need to make sure we are still in
14104 	 * ticks granularity (though we should probably
14105 	 * change bbr to go to USECs).
14106 	 *
14107 	 * For timers we need to see if we are still in the
14108 	 * pacer (if our flags are up) if so we are good, if
14109 	 * not we need to get back into the pacer.
14110 	 */
14111 	struct timeval tv;
14112 	uint32_t cts;
14113 	uint32_t toval;
14114 	struct tcp_bbr *bbr;
14115 	struct hpts_diag diag;
14116 
14117 	tp->t_flags2 |= TF2_CANNOT_DO_ECN;
14118 	tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
14119 	tcp_change_time_units(tp, TCP_TMR_GRANULARITY_TICKS);
14120 	if (tp->t_in_hpts > IHPTS_NONE) {
14121 		return;
14122 	}
14123 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
14124 	cts = tcp_get_usecs(&tv);
14125 	if (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
14126 		if (TSTMP_GT(bbr->rc_pacer_started, cts)) {
14127 			toval = bbr->rc_pacer_started - cts;
14128 		} else {
14129 			/* one slot please */
14130 			toval = HPTS_TICKS_PER_SLOT;
14131 		}
14132 	} else if (bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
14133 		if (TSTMP_GT(bbr->r_ctl.rc_timer_exp, cts)) {
14134 			toval = bbr->r_ctl.rc_timer_exp - cts;
14135 		} else {
14136 			/* one slot please */
14137 			toval = HPTS_TICKS_PER_SLOT;
14138 		}
14139 	} else
14140 		toval = HPTS_TICKS_PER_SLOT;
14141 	(void)tcp_hpts_insert_diag(tp, HPTS_USEC_TO_SLOTS(toval),
14142 				   __LINE__, &diag);
14143 	bbr_log_hpts_diag(bbr, cts, &diag);
14144 }
14145 
14146 struct tcp_function_block __tcp_bbr = {
14147 	.tfb_tcp_block_name = __XSTRING(STACKNAME),
14148 	.tfb_tcp_output = bbr_output,
14149 	.tfb_do_queued_segments = ctf_do_queued_segments,
14150 	.tfb_do_segment_nounlock = bbr_do_segment_nounlock,
14151 	.tfb_tcp_do_segment = bbr_do_segment,
14152 	.tfb_tcp_ctloutput = bbr_ctloutput,
14153 	.tfb_tcp_fb_init = bbr_init,
14154 	.tfb_tcp_fb_fini = bbr_fini,
14155 	.tfb_tcp_timer_stop_all = bbr_stopall,
14156 	.tfb_tcp_rexmit_tmr = bbr_remxt_tmr,
14157 	.tfb_tcp_handoff_ok = bbr_handoff_ok,
14158 	.tfb_tcp_mtu_chg = bbr_mtu_chg,
14159 	.tfb_pru_options = bbr_pru_options,
14160 	.tfb_switch_failed = bbr_switch_failed,
14161 	.tfb_flags = TCP_FUNC_OUTPUT_CANDROP | TCP_FUNC_DEFAULT_OK,
14162 };
14163 
14164 /*
14165  * bbr_ctloutput() must drop the inpcb lock before performing copyin on
14166  * socket option arguments.  When it re-acquires the lock after the copy, it
14167  * has to revalidate that the connection is still valid for the socket
14168  * option.
14169  */
14170 static int
14171 bbr_set_sockopt(struct tcpcb *tp, struct sockopt *sopt)
14172 {
14173 	struct epoch_tracker et;
14174 	struct inpcb *inp = tptoinpcb(tp);
14175 	struct tcp_bbr *bbr;
14176 	int32_t error = 0, optval;
14177 
14178 	switch (sopt->sopt_level) {
14179 	case IPPROTO_IPV6:
14180 	case IPPROTO_IP:
14181 		return (tcp_default_ctloutput(tp, sopt));
14182 	}
14183 
14184 	switch (sopt->sopt_name) {
14185 	case TCP_RACK_PACE_MAX_SEG:
14186 	case TCP_RACK_MIN_TO:
14187 	case TCP_RACK_REORD_THRESH:
14188 	case TCP_RACK_REORD_FADE:
14189 	case TCP_RACK_TLP_THRESH:
14190 	case TCP_RACK_PKT_DELAY:
14191 	case TCP_BBR_ALGORITHM:
14192 	case TCP_BBR_TSLIMITS:
14193 	case TCP_BBR_IWINTSO:
14194 	case TCP_BBR_STARTUP_PG:
14195 	case TCP_BBR_DRAIN_PG:
14196 	case TCP_BBR_PROBE_RTT_INT:
14197 	case TCP_BBR_PROBE_RTT_GAIN:
14198 	case TCP_BBR_PROBE_RTT_LEN:
14199 	case TCP_BBR_STARTUP_LOSS_EXIT:
14200 	case TCP_BBR_USEDEL_RATE:
14201 	case TCP_BBR_MIN_RTO:
14202 	case TCP_BBR_MAX_RTO:
14203 	case TCP_BBR_PACE_PER_SEC:
14204 	case TCP_DELACK:
14205 	case TCP_BBR_PACE_DEL_TAR:
14206 	case TCP_BBR_SEND_IWND_IN_TSO:
14207 	case TCP_BBR_EXTRA_STATE:
14208 	case TCP_BBR_UTTER_MAX_TSO:
14209 	case TCP_BBR_MIN_TOPACEOUT:
14210 	case TCP_BBR_FLOOR_MIN_TSO:
14211 	case TCP_BBR_TSTMP_RAISES:
14212 	case TCP_BBR_POLICER_DETECT:
14213 	case TCP_BBR_USE_RACK_CHEAT:
14214 	case TCP_DATA_AFTER_CLOSE:
14215 	case TCP_BBR_HDWR_PACE:
14216 	case TCP_BBR_PACE_SEG_MAX:
14217 	case TCP_BBR_PACE_SEG_MIN:
14218 	case TCP_BBR_PACE_CROSS:
14219 	case TCP_BBR_PACE_OH:
14220 	case TCP_BBR_TMR_PACE_OH:
14221 	case TCP_BBR_RACK_RTT_USE:
14222 	case TCP_BBR_RETRAN_WTSO:
14223 		break;
14224 	default:
14225 		return (tcp_default_ctloutput(tp, sopt));
14226 		break;
14227 	}
14228 	INP_WUNLOCK(inp);
14229 	error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval));
14230 	if (error)
14231 		return (error);
14232 	INP_WLOCK(inp);
14233 	if (inp->inp_flags & INP_DROPPED) {
14234 		INP_WUNLOCK(inp);
14235 		return (ECONNRESET);
14236 	}
14237 	if (tp->t_fb != &__tcp_bbr) {
14238 		INP_WUNLOCK(inp);
14239 		return (ENOPROTOOPT);
14240 	}
14241 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
14242 	switch (sopt->sopt_name) {
14243 	case TCP_BBR_PACE_PER_SEC:
14244 		BBR_OPTS_INC(tcp_bbr_pace_per_sec);
14245 		bbr->r_ctl.bbr_hptsi_per_second = optval;
14246 		break;
14247 	case TCP_BBR_PACE_DEL_TAR:
14248 		BBR_OPTS_INC(tcp_bbr_pace_del_tar);
14249 		bbr->r_ctl.bbr_hptsi_segments_delay_tar = optval;
14250 		break;
14251 	case TCP_BBR_PACE_SEG_MAX:
14252 		BBR_OPTS_INC(tcp_bbr_pace_seg_max);
14253 		bbr->r_ctl.bbr_hptsi_segments_max = optval;
14254 		break;
14255 	case TCP_BBR_PACE_SEG_MIN:
14256 		BBR_OPTS_INC(tcp_bbr_pace_seg_min);
14257 		bbr->r_ctl.bbr_hptsi_bytes_min = optval;
14258 		break;
14259 	case TCP_BBR_PACE_CROSS:
14260 		BBR_OPTS_INC(tcp_bbr_pace_cross);
14261 		bbr->r_ctl.bbr_cross_over = optval;
14262 		break;
14263 	case TCP_BBR_ALGORITHM:
14264 		BBR_OPTS_INC(tcp_bbr_algorithm);
14265 		if (optval && (bbr->rc_use_google == 0)) {
14266 			/* Turn on the google mode */
14267 			bbr_google_mode_on(bbr);
14268 			if ((optval > 3) && (optval < 500)) {
14269 				/*
14270 				 * Must be at least greater than .3%
14271 				 * and must be less than 50.0%.
14272 				 */
14273 				bbr->r_ctl.bbr_google_discount = optval;
14274 			}
14275 		} else if ((optval == 0) && (bbr->rc_use_google == 1)) {
14276 			/* Turn off the google mode */
14277 			bbr_google_mode_off(bbr);
14278 		}
14279 		break;
14280 	case TCP_BBR_TSLIMITS:
14281 		BBR_OPTS_INC(tcp_bbr_tslimits);
14282 		if (optval == 1)
14283 			bbr->rc_use_ts_limit = 1;
14284 		else if (optval == 0)
14285 			bbr->rc_use_ts_limit = 0;
14286 		else
14287 			error = EINVAL;
14288 		break;
14289 
14290 	case TCP_BBR_IWINTSO:
14291 		BBR_OPTS_INC(tcp_bbr_iwintso);
14292 		if ((optval >= 0) && (optval < 128)) {
14293 			uint32_t twin;
14294 
14295 			bbr->rc_init_win = optval;
14296 			twin = bbr_initial_cwnd(bbr, tp);
14297 			if ((bbr->rc_past_init_win == 0) && (twin > tp->snd_cwnd))
14298 				tp->snd_cwnd = twin;
14299 			else
14300 				error = EBUSY;
14301 		} else
14302 			error = EINVAL;
14303 		break;
14304 	case TCP_BBR_STARTUP_PG:
14305 		BBR_OPTS_INC(tcp_bbr_startup_pg);
14306 		if ((optval > 0) && (optval < BBR_MAX_GAIN_VALUE)) {
14307 			bbr->r_ctl.rc_startup_pg = optval;
14308 			if (bbr->rc_bbr_state == BBR_STATE_STARTUP) {
14309 				bbr->r_ctl.rc_bbr_hptsi_gain = optval;
14310 			}
14311 		} else
14312 			error = EINVAL;
14313 		break;
14314 	case TCP_BBR_DRAIN_PG:
14315 		BBR_OPTS_INC(tcp_bbr_drain_pg);
14316 		if ((optval > 0) && (optval < BBR_MAX_GAIN_VALUE))
14317 			bbr->r_ctl.rc_drain_pg = optval;
14318 		else
14319 			error = EINVAL;
14320 		break;
14321 	case TCP_BBR_PROBE_RTT_LEN:
14322 		BBR_OPTS_INC(tcp_bbr_probertt_len);
14323 		if (optval <= 1)
14324 			reset_time_small(&bbr->r_ctl.rc_rttprop, (optval * USECS_IN_SECOND));
14325 		else
14326 			error = EINVAL;
14327 		break;
14328 	case TCP_BBR_PROBE_RTT_GAIN:
14329 		BBR_OPTS_INC(tcp_bbr_probertt_gain);
14330 		if (optval <= BBR_UNIT)
14331 			bbr->r_ctl.bbr_rttprobe_gain_val = optval;
14332 		else
14333 			error = EINVAL;
14334 		break;
14335 	case TCP_BBR_PROBE_RTT_INT:
14336 		BBR_OPTS_INC(tcp_bbr_probe_rtt_int);
14337 		if (optval > 1000)
14338 			bbr->r_ctl.rc_probertt_int = optval;
14339 		else
14340 			error = EINVAL;
14341 		break;
14342 	case TCP_BBR_MIN_TOPACEOUT:
14343 		BBR_OPTS_INC(tcp_bbr_topaceout);
14344 		if (optval == 0) {
14345 			bbr->no_pacing_until = 0;
14346 			bbr->rc_no_pacing = 0;
14347 		} else if (optval <= 0x00ff) {
14348 			bbr->no_pacing_until = optval;
14349 			if ((bbr->r_ctl.rc_pkt_epoch < bbr->no_pacing_until) &&
14350 			    (bbr->rc_bbr_state == BBR_STATE_STARTUP)){
14351 				/* Turn on no pacing */
14352 				bbr->rc_no_pacing = 1;
14353 			}
14354 		} else
14355 			error = EINVAL;
14356 		break;
14357 	case TCP_BBR_STARTUP_LOSS_EXIT:
14358 		BBR_OPTS_INC(tcp_bbr_startup_loss_exit);
14359 		bbr->rc_loss_exit = optval;
14360 		break;
14361 	case TCP_BBR_USEDEL_RATE:
14362 		error = EINVAL;
14363 		break;
14364 	case TCP_BBR_MIN_RTO:
14365 		BBR_OPTS_INC(tcp_bbr_min_rto);
14366 		bbr->r_ctl.rc_min_rto_ms = optval;
14367 		break;
14368 	case TCP_BBR_MAX_RTO:
14369 		BBR_OPTS_INC(tcp_bbr_max_rto);
14370 		bbr->rc_max_rto_sec = optval;
14371 		break;
14372 	case TCP_RACK_MIN_TO:
14373 		/* Minimum time between rack t-o's in ms */
14374 		BBR_OPTS_INC(tcp_rack_min_to);
14375 		bbr->r_ctl.rc_min_to = optval;
14376 		break;
14377 	case TCP_RACK_REORD_THRESH:
14378 		/* RACK reorder threshold (shift amount) */
14379 		BBR_OPTS_INC(tcp_rack_reord_thresh);
14380 		if ((optval > 0) && (optval < 31))
14381 			bbr->r_ctl.rc_reorder_shift = optval;
14382 		else
14383 			error = EINVAL;
14384 		break;
14385 	case TCP_RACK_REORD_FADE:
14386 		/* Does reordering fade after ms time */
14387 		BBR_OPTS_INC(tcp_rack_reord_fade);
14388 		bbr->r_ctl.rc_reorder_fade = optval;
14389 		break;
14390 	case TCP_RACK_TLP_THRESH:
14391 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
14392 		BBR_OPTS_INC(tcp_rack_tlp_thresh);
14393 		if (optval)
14394 			bbr->rc_tlp_threshold = optval;
14395 		else
14396 			error = EINVAL;
14397 		break;
14398 	case TCP_BBR_USE_RACK_CHEAT:
14399 		BBR_OPTS_INC(tcp_use_rackcheat);
14400 		if (bbr->rc_use_google) {
14401 			error = EINVAL;
14402 			break;
14403 		}
14404 		BBR_OPTS_INC(tcp_rack_cheat);
14405 		if (optval)
14406 			bbr->bbr_use_rack_cheat = 1;
14407 		else
14408 			bbr->bbr_use_rack_cheat = 0;
14409 		break;
14410 	case TCP_BBR_FLOOR_MIN_TSO:
14411 		BBR_OPTS_INC(tcp_utter_max_tso);
14412 		if ((optval >= 0) && (optval < 40))
14413 			bbr->r_ctl.bbr_hptsi_segments_floor = optval;
14414 		else
14415 			error = EINVAL;
14416 		break;
14417 	case TCP_BBR_UTTER_MAX_TSO:
14418 		BBR_OPTS_INC(tcp_utter_max_tso);
14419 		if ((optval >= 0) && (optval < 0xffff))
14420 			bbr->r_ctl.bbr_utter_max = optval;
14421 		else
14422 			error = EINVAL;
14423 		break;
14424 
14425 	case TCP_BBR_EXTRA_STATE:
14426 		BBR_OPTS_INC(tcp_extra_state);
14427 		if (optval)
14428 			bbr->rc_use_idle_restart = 1;
14429 		else
14430 			bbr->rc_use_idle_restart = 0;
14431 		break;
14432 	case TCP_BBR_SEND_IWND_IN_TSO:
14433 		BBR_OPTS_INC(tcp_iwnd_tso);
14434 		if (optval) {
14435 			bbr->bbr_init_win_cheat = 1;
14436 			if (bbr->rc_past_init_win == 0) {
14437 				uint32_t cts;
14438 				cts = tcp_get_usecs(&bbr->rc_tv);
14439 				tcp_bbr_tso_size_check(bbr, cts);
14440 			}
14441 		} else
14442 			bbr->bbr_init_win_cheat = 0;
14443 		break;
14444 	case TCP_BBR_HDWR_PACE:
14445 		BBR_OPTS_INC(tcp_hdwr_pacing);
14446 		if (optval){
14447 			bbr->bbr_hdw_pace_ena = 1;
14448 			bbr->bbr_attempt_hdwr_pace = 0;
14449 		} else {
14450 			bbr->bbr_hdw_pace_ena = 0;
14451 #ifdef RATELIMIT
14452 			if (bbr->r_ctl.crte != NULL) {
14453 				tcp_rel_pacing_rate(bbr->r_ctl.crte, tp);
14454 				bbr->r_ctl.crte = NULL;
14455 			}
14456 #endif
14457 		}
14458 		break;
14459 
14460 	case TCP_DELACK:
14461 		BBR_OPTS_INC(tcp_delack);
14462 		if (optval < 100) {
14463 			if (optval == 0) /* off */
14464 				tp->t_delayed_ack = 0;
14465 			else if (optval == 1) /* on which is 2 */
14466 				tp->t_delayed_ack = 2;
14467 			else /* higher than 2 and less than 100 */
14468 				tp->t_delayed_ack = optval;
14469 			if (tp->t_flags & TF_DELACK) {
14470 				tp->t_flags &= ~TF_DELACK;
14471 				tp->t_flags |= TF_ACKNOW;
14472 				NET_EPOCH_ENTER(et);
14473 				bbr_output(tp);
14474 				NET_EPOCH_EXIT(et);
14475 			}
14476 		} else
14477 			error = EINVAL;
14478 		break;
14479 	case TCP_RACK_PKT_DELAY:
14480 		/* RACK added ms i.e. rack-rtt + reord + N */
14481 		BBR_OPTS_INC(tcp_rack_pkt_delay);
14482 		bbr->r_ctl.rc_pkt_delay = optval;
14483 		break;
14484 
14485 	case TCP_BBR_RETRAN_WTSO:
14486 		BBR_OPTS_INC(tcp_retran_wtso);
14487 		if (optval)
14488 			bbr->rc_resends_use_tso = 1;
14489 		else
14490 			bbr->rc_resends_use_tso = 0;
14491 		break;
14492 	case TCP_DATA_AFTER_CLOSE:
14493 		BBR_OPTS_INC(tcp_data_ac);
14494 		if (optval)
14495 			bbr->rc_allow_data_af_clo = 1;
14496 		else
14497 			bbr->rc_allow_data_af_clo = 0;
14498 		break;
14499 	case TCP_BBR_POLICER_DETECT:
14500 		BBR_OPTS_INC(tcp_policer_det);
14501 		if (bbr->rc_use_google == 0)
14502 			error = EINVAL;
14503 		else if (optval)
14504 			bbr->r_use_policer = 1;
14505 		else
14506 			bbr->r_use_policer = 0;
14507 		break;
14508 
14509 	case TCP_BBR_TSTMP_RAISES:
14510 		BBR_OPTS_INC(tcp_ts_raises);
14511 		if (optval)
14512 			bbr->ts_can_raise = 1;
14513 		else
14514 			bbr->ts_can_raise = 0;
14515 		break;
14516 	case TCP_BBR_TMR_PACE_OH:
14517 		BBR_OPTS_INC(tcp_pacing_oh_tmr);
14518 		if (bbr->rc_use_google) {
14519 			error = EINVAL;
14520 		} else {
14521 			if (optval)
14522 				bbr->r_ctl.rc_incr_tmrs = 1;
14523 			else
14524 				bbr->r_ctl.rc_incr_tmrs = 0;
14525 		}
14526 		break;
14527 	case TCP_BBR_PACE_OH:
14528 		BBR_OPTS_INC(tcp_pacing_oh);
14529 		if (bbr->rc_use_google) {
14530 			error = EINVAL;
14531 		} else {
14532 			if (optval > (BBR_INCL_TCP_OH|
14533 				      BBR_INCL_IP_OH|
14534 				      BBR_INCL_ENET_OH)) {
14535 				error = EINVAL;
14536 				break;
14537 			}
14538 			if (optval & BBR_INCL_TCP_OH)
14539 				bbr->r_ctl.rc_inc_tcp_oh = 1;
14540 			else
14541 				bbr->r_ctl.rc_inc_tcp_oh = 0;
14542 			if (optval & BBR_INCL_IP_OH)
14543 				bbr->r_ctl.rc_inc_ip_oh = 1;
14544 			else
14545 				bbr->r_ctl.rc_inc_ip_oh = 0;
14546 			if (optval & BBR_INCL_ENET_OH)
14547 				bbr->r_ctl.rc_inc_enet_oh = 1;
14548 			else
14549 				bbr->r_ctl.rc_inc_enet_oh = 0;
14550 		}
14551 		break;
14552 	default:
14553 		return (tcp_default_ctloutput(tp, sopt));
14554 		break;
14555 	}
14556 	tcp_log_socket_option(tp, sopt->sopt_name, optval, error);
14557 	INP_WUNLOCK(inp);
14558 	return (error);
14559 }
14560 
14561 /*
14562  * return 0 on success, error-num on failure
14563  */
14564 static int
14565 bbr_get_sockopt(struct tcpcb *tp, struct sockopt *sopt)
14566 {
14567 	struct inpcb *inp = tptoinpcb(tp);
14568 	struct tcp_bbr *bbr;
14569 	uint64_t loptval;
14570 	int32_t error, optval;
14571 
14572 	bbr = (struct tcp_bbr *)tp->t_fb_ptr;
14573 	if (bbr == NULL) {
14574 		INP_WUNLOCK(inp);
14575 		return (EINVAL);
14576 	}
14577 	/*
14578 	 * Because all our options are either boolean or an int, we can just
14579 	 * pull everything into optval and then unlock and copy. If we ever
14580 	 * add a option that is not a int, then this will have quite an
14581 	 * impact to this routine.
14582 	 */
14583 	switch (sopt->sopt_name) {
14584 	case TCP_BBR_PACE_PER_SEC:
14585 		optval = bbr->r_ctl.bbr_hptsi_per_second;
14586 		break;
14587 	case TCP_BBR_PACE_DEL_TAR:
14588 		optval = bbr->r_ctl.bbr_hptsi_segments_delay_tar;
14589 		break;
14590 	case TCP_BBR_PACE_SEG_MAX:
14591 		optval = bbr->r_ctl.bbr_hptsi_segments_max;
14592 		break;
14593 	case TCP_BBR_MIN_TOPACEOUT:
14594 		optval = bbr->no_pacing_until;
14595 		break;
14596 	case TCP_BBR_PACE_SEG_MIN:
14597 		optval = bbr->r_ctl.bbr_hptsi_bytes_min;
14598 		break;
14599 	case TCP_BBR_PACE_CROSS:
14600 		optval = bbr->r_ctl.bbr_cross_over;
14601 		break;
14602 	case TCP_BBR_ALGORITHM:
14603 		optval = bbr->rc_use_google;
14604 		break;
14605 	case TCP_BBR_TSLIMITS:
14606 		optval = bbr->rc_use_ts_limit;
14607 		break;
14608 	case TCP_BBR_IWINTSO:
14609 		optval = bbr->rc_init_win;
14610 		break;
14611 	case TCP_BBR_STARTUP_PG:
14612 		optval = bbr->r_ctl.rc_startup_pg;
14613 		break;
14614 	case TCP_BBR_DRAIN_PG:
14615 		optval = bbr->r_ctl.rc_drain_pg;
14616 		break;
14617 	case TCP_BBR_PROBE_RTT_INT:
14618 		optval = bbr->r_ctl.rc_probertt_int;
14619 		break;
14620 	case TCP_BBR_PROBE_RTT_LEN:
14621 		optval = (bbr->r_ctl.rc_rttprop.cur_time_limit / USECS_IN_SECOND);
14622 		break;
14623 	case TCP_BBR_PROBE_RTT_GAIN:
14624 		optval = bbr->r_ctl.bbr_rttprobe_gain_val;
14625 		break;
14626 	case TCP_BBR_STARTUP_LOSS_EXIT:
14627 		optval = bbr->rc_loss_exit;
14628 		break;
14629 	case TCP_BBR_USEDEL_RATE:
14630 		loptval = get_filter_value(&bbr->r_ctl.rc_delrate);
14631 		break;
14632 	case TCP_BBR_MIN_RTO:
14633 		optval = bbr->r_ctl.rc_min_rto_ms;
14634 		break;
14635 	case TCP_BBR_MAX_RTO:
14636 		optval = bbr->rc_max_rto_sec;
14637 		break;
14638 	case TCP_RACK_PACE_MAX_SEG:
14639 		/* Max segments in a pace */
14640 		optval = bbr->r_ctl.rc_pace_max_segs;
14641 		break;
14642 	case TCP_RACK_MIN_TO:
14643 		/* Minimum time between rack t-o's in ms */
14644 		optval = bbr->r_ctl.rc_min_to;
14645 		break;
14646 	case TCP_RACK_REORD_THRESH:
14647 		/* RACK reorder threshold (shift amount) */
14648 		optval = bbr->r_ctl.rc_reorder_shift;
14649 		break;
14650 	case TCP_RACK_REORD_FADE:
14651 		/* Does reordering fade after ms time */
14652 		optval = bbr->r_ctl.rc_reorder_fade;
14653 		break;
14654 	case TCP_BBR_USE_RACK_CHEAT:
14655 		/* Do we use the rack cheat for rxt */
14656 		optval = bbr->bbr_use_rack_cheat;
14657 		break;
14658 	case TCP_BBR_FLOOR_MIN_TSO:
14659 		optval = bbr->r_ctl.bbr_hptsi_segments_floor;
14660 		break;
14661 	case TCP_BBR_UTTER_MAX_TSO:
14662 		optval = bbr->r_ctl.bbr_utter_max;
14663 		break;
14664 	case TCP_BBR_SEND_IWND_IN_TSO:
14665 		/* Do we send TSO size segments initially */
14666 		optval = bbr->bbr_init_win_cheat;
14667 		break;
14668 	case TCP_BBR_EXTRA_STATE:
14669 		optval = bbr->rc_use_idle_restart;
14670 		break;
14671 	case TCP_RACK_TLP_THRESH:
14672 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
14673 		optval = bbr->rc_tlp_threshold;
14674 		break;
14675 	case TCP_RACK_PKT_DELAY:
14676 		/* RACK added ms i.e. rack-rtt + reord + N */
14677 		optval = bbr->r_ctl.rc_pkt_delay;
14678 		break;
14679 	case TCP_BBR_RETRAN_WTSO:
14680 		optval = bbr->rc_resends_use_tso;
14681 		break;
14682 	case TCP_DATA_AFTER_CLOSE:
14683 		optval = bbr->rc_allow_data_af_clo;
14684 		break;
14685 	case TCP_DELACK:
14686 		optval = tp->t_delayed_ack;
14687 		break;
14688 	case TCP_BBR_HDWR_PACE:
14689 		optval = bbr->bbr_hdw_pace_ena;
14690 		break;
14691 	case TCP_BBR_POLICER_DETECT:
14692 		optval = bbr->r_use_policer;
14693 		break;
14694 	case TCP_BBR_TSTMP_RAISES:
14695 		optval = bbr->ts_can_raise;
14696 		break;
14697 	case TCP_BBR_TMR_PACE_OH:
14698 		optval = bbr->r_ctl.rc_incr_tmrs;
14699 		break;
14700 	case TCP_BBR_PACE_OH:
14701 		optval = 0;
14702 		if (bbr->r_ctl.rc_inc_tcp_oh)
14703 			optval |= BBR_INCL_TCP_OH;
14704 		if (bbr->r_ctl.rc_inc_ip_oh)
14705 			optval |= BBR_INCL_IP_OH;
14706 		if (bbr->r_ctl.rc_inc_enet_oh)
14707 			optval |= BBR_INCL_ENET_OH;
14708 		break;
14709 	default:
14710 		return (tcp_default_ctloutput(tp, sopt));
14711 		break;
14712 	}
14713 	INP_WUNLOCK(inp);
14714 	if (sopt->sopt_name == TCP_BBR_USEDEL_RATE)
14715 		error = sooptcopyout(sopt, &loptval, sizeof loptval);
14716 	else
14717 		error = sooptcopyout(sopt, &optval, sizeof optval);
14718 	return (error);
14719 }
14720 
14721 /*
14722  * return 0 on success, error-num on failure
14723  */
14724 static int
14725 bbr_ctloutput(struct tcpcb *tp, struct sockopt *sopt)
14726 {
14727 	if (sopt->sopt_dir == SOPT_SET) {
14728 		return (bbr_set_sockopt(tp, sopt));
14729 	} else if (sopt->sopt_dir == SOPT_GET) {
14730 		return (bbr_get_sockopt(tp, sopt));
14731 	} else {
14732 		panic("%s: sopt_dir $%d", __func__, sopt->sopt_dir);
14733 	}
14734 }
14735 
14736 static const char *bbr_stack_names[] = {
14737 	__XSTRING(STACKNAME),
14738 #ifdef STACKALIAS
14739 	__XSTRING(STACKALIAS),
14740 #endif
14741 };
14742 
14743 static bool bbr_mod_inited = false;
14744 
14745 static int
14746 tcp_addbbr(module_t mod, int32_t type, void *data)
14747 {
14748 	int32_t err = 0;
14749 	int num_stacks;
14750 
14751 	switch (type) {
14752 	case MOD_LOAD:
14753 		printf("Attempting to load " __XSTRING(MODNAME) "\n");
14754 		bbr_zone = uma_zcreate(__XSTRING(MODNAME) "_map",
14755 		    sizeof(struct bbr_sendmap),
14756 		    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
14757 		bbr_pcb_zone = uma_zcreate(__XSTRING(MODNAME) "_pcb",
14758 		    sizeof(struct tcp_bbr),
14759 		    NULL, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
14760 		sysctl_ctx_init(&bbr_sysctl_ctx);
14761 		bbr_sysctl_root = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
14762 		    SYSCTL_STATIC_CHILDREN(_net_inet_tcp),
14763 		    OID_AUTO,
14764 #ifdef STACKALIAS
14765 		    __XSTRING(STACKALIAS),
14766 #else
14767 		    __XSTRING(STACKNAME),
14768 #endif
14769 		    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
14770 		    "");
14771 		if (bbr_sysctl_root == NULL) {
14772 			printf("Failed to add sysctl node\n");
14773 			err = EFAULT;
14774 			goto free_uma;
14775 		}
14776 		bbr_init_sysctls();
14777 		num_stacks = nitems(bbr_stack_names);
14778 		err = register_tcp_functions_as_names(&__tcp_bbr, M_WAITOK,
14779 		    bbr_stack_names, &num_stacks);
14780 		if (err) {
14781 			printf("Failed to register %s stack name for "
14782 			    "%s module\n", bbr_stack_names[num_stacks],
14783 			    __XSTRING(MODNAME));
14784 			sysctl_ctx_free(&bbr_sysctl_ctx);
14785 	free_uma:
14786 			uma_zdestroy(bbr_zone);
14787 			uma_zdestroy(bbr_pcb_zone);
14788 			bbr_counter_destroy();
14789 			printf("Failed to register " __XSTRING(MODNAME)
14790 			    " module err:%d\n", err);
14791 			return (err);
14792 		}
14793 		tcp_lro_reg_mbufq();
14794 		bbr_mod_inited = true;
14795 		printf(__XSTRING(MODNAME) " is now available\n");
14796 		break;
14797 	case MOD_QUIESCE:
14798 		err = deregister_tcp_functions(&__tcp_bbr, true, false);
14799 		break;
14800 	case MOD_UNLOAD:
14801 		err = deregister_tcp_functions(&__tcp_bbr, false, true);
14802 		if (err == EBUSY)
14803 			break;
14804 		if (bbr_mod_inited) {
14805 			uma_zdestroy(bbr_zone);
14806 			uma_zdestroy(bbr_pcb_zone);
14807 			sysctl_ctx_free(&bbr_sysctl_ctx);
14808 			bbr_counter_destroy();
14809 			printf(__XSTRING(MODNAME)
14810 			    " is now no longer available\n");
14811 			bbr_mod_inited = false;
14812 		}
14813 		tcp_lro_dereg_mbufq();
14814 		err = 0;
14815 		break;
14816 	default:
14817 		return (EOPNOTSUPP);
14818 	}
14819 	return (err);
14820 }
14821 
14822 static moduledata_t tcp_bbr = {
14823 	.name = __XSTRING(MODNAME),
14824 	    .evhand = tcp_addbbr,
14825 	    .priv = 0
14826 };
14827 
14828 MODULE_VERSION(MODNAME, 1);
14829 DECLARE_MODULE(MODNAME, tcp_bbr, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
14830 MODULE_DEPEND(MODNAME, tcphpts, 1, 1, 1);
14831