xref: /freebsd/sys/netinet/tcp_stacks/rack.c (revision b11aebff4d4a301bfeac516b5be45080c8a11142) 
1 /*-
2  * Copyright (c) 2016-2020 Netflix, Inc.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  *
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include "opt_inet.h"
31 #include "opt_inet6.h"
32 #include "opt_ipsec.h"
33 #include "opt_tcpdebug.h"
34 #include "opt_ratelimit.h"
35 #include "opt_kern_tls.h"
36 #include <sys/param.h>
37 #include <sys/arb.h>
38 #include <sys/module.h>
39 #include <sys/kernel.h>
40 #ifdef TCP_HHOOK
41 #include <sys/hhook.h>
42 #endif
43 #include <sys/lock.h>
44 #include <sys/malloc.h>
45 #include <sys/lock.h>
46 #include <sys/mutex.h>
47 #include <sys/mbuf.h>
48 #include <sys/proc.h>		/* for proc0 declaration */
49 #include <sys/socket.h>
50 #include <sys/socketvar.h>
51 #include <sys/sysctl.h>
52 #include <sys/systm.h>
53 #ifdef STATS
54 #include <sys/qmath.h>
55 #include <sys/tree.h>
56 #include <sys/stats.h> /* Must come after qmath.h and tree.h */
57 #else
58 #include <sys/tree.h>
59 #endif
60 #include <sys/refcount.h>
61 #include <sys/queue.h>
62 #include <sys/tim_filter.h>
63 #include <sys/smp.h>
64 #include <sys/kthread.h>
65 #include <sys/kern_prefetch.h>
66 #include <sys/protosw.h>
67 #ifdef TCP_ACCOUNTING
68 #include <sys/sched.h>
69 #include <machine/cpu.h>
70 #endif
71 #include <vm/uma.h>
72 
73 #include <net/route.h>
74 #include <net/route/nhop.h>
75 #include <net/vnet.h>
76 
77 #define TCPSTATES		/* for logging */
78 
79 #include <netinet/in.h>
80 #include <netinet/in_kdtrace.h>
81 #include <netinet/in_pcb.h>
82 #include <netinet/ip.h>
83 #include <netinet/ip_icmp.h>	/* required for icmp_var.h */
84 #include <netinet/icmp_var.h>	/* for ICMP_BANDLIM */
85 #include <netinet/ip_var.h>
86 #include <netinet/ip6.h>
87 #include <netinet6/in6_pcb.h>
88 #include <netinet6/ip6_var.h>
89 #include <netinet/tcp.h>
90 #define	TCPOUTFLAGS
91 #include <netinet/tcp_fsm.h>
92 #include <netinet/tcp_log_buf.h>
93 #include <netinet/tcp_seq.h>
94 #include <netinet/tcp_timer.h>
95 #include <netinet/tcp_var.h>
96 #include <netinet/tcp_syncache.h>
97 #include <netinet/tcp_hpts.h>
98 #include <netinet/tcp_ratelimit.h>
99 #include <netinet/tcp_accounting.h>
100 #include <netinet/tcpip.h>
101 #include <netinet/cc/cc.h>
102 #include <netinet/cc/cc_newreno.h>
103 #include <netinet/tcp_fastopen.h>
104 #include <netinet/tcp_lro.h>
105 #ifdef NETFLIX_SHARED_CWND
106 #include <netinet/tcp_shared_cwnd.h>
107 #endif
108 #ifdef TCPDEBUG
109 #include <netinet/tcp_debug.h>
110 #endif				/* TCPDEBUG */
111 #ifdef TCP_OFFLOAD
112 #include <netinet/tcp_offload.h>
113 #endif
114 #ifdef INET6
115 #include <netinet6/tcp6_var.h>
116 #endif
117 #include <netinet/tcp_ecn.h>
118 
119 #include <netipsec/ipsec_support.h>
120 
121 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
122 #include <netipsec/ipsec.h>
123 #include <netipsec/ipsec6.h>
124 #endif				/* IPSEC */
125 
126 #include <netinet/udp.h>
127 #include <netinet/udp_var.h>
128 #include <machine/in_cksum.h>
129 
130 #ifdef MAC
131 #include <security/mac/mac_framework.h>
132 #endif
133 #include "sack_filter.h"
134 #include "tcp_rack.h"
135 #include "rack_bbr_common.h"
136 
137 uma_zone_t rack_zone;
138 uma_zone_t rack_pcb_zone;
139 
140 #ifndef TICKS2SBT
141 #define	TICKS2SBT(__t)	(tick_sbt * ((sbintime_t)(__t)))
142 #endif
143 
144 VNET_DECLARE(uint32_t, newreno_beta);
145 VNET_DECLARE(uint32_t, newreno_beta_ecn);
146 #define V_newreno_beta VNET(newreno_beta)
147 #define V_newreno_beta_ecn VNET(newreno_beta_ecn)
148 
149 
150 MALLOC_DEFINE(M_TCPFSB, "tcp_fsb", "TCP fast send block");
151 MALLOC_DEFINE(M_TCPDO, "tcp_do", "TCP deferred options");
152 
153 struct sysctl_ctx_list rack_sysctl_ctx;
154 struct sysctl_oid *rack_sysctl_root;
155 
156 #define CUM_ACKED 1
157 #define SACKED 2
158 
159 /*
160  * The RACK module incorporates a number of
161  * TCP ideas that have been put out into the IETF
162  * over the last few years:
163  * - Matt Mathis's Rate Halving which slowly drops
164  *    the congestion window so that the ack clock can
165  *    be maintained during a recovery.
166  * - Yuchung Cheng's RACK TCP (for which its named) that
167  *    will stop us using the number of dup acks and instead
168  *    use time as the gage of when we retransmit.
169  * - Reorder Detection of RFC4737 and the Tail-Loss probe draft
170  *    of Dukkipati et.al.
171  * RACK depends on SACK, so if an endpoint arrives that
172  * cannot do SACK the state machine below will shuttle the
173  * connection back to using the "default" TCP stack that is
174  * in FreeBSD.
175  *
176  * To implement RACK the original TCP stack was first decomposed
177  * into a functional state machine with individual states
178  * for each of the possible TCP connection states. The do_segment
179  * functions role in life is to mandate the connection supports SACK
180  * initially and then assure that the RACK state matches the conenction
181  * state before calling the states do_segment function. Each
182  * state is simplified due to the fact that the original do_segment
183  * has been decomposed and we *know* what state we are in (no
184  * switches on the state) and all tests for SACK are gone. This
185  * greatly simplifies what each state does.
186  *
187  * TCP output is also over-written with a new version since it
188  * must maintain the new rack scoreboard.
189  *
190  */
191 static int32_t rack_tlp_thresh = 1;
192 static int32_t rack_tlp_limit = 2;	/* No more than 2 TLPs w-out new data */
193 static int32_t rack_tlp_use_greater = 1;
194 static int32_t rack_reorder_thresh = 2;
195 static int32_t rack_reorder_fade = 60000000;	/* 0 - never fade, def 60,000,000
196 						 * - 60 seconds */
197 static uint8_t rack_req_measurements = 1;
198 /* Attack threshold detections */
199 static uint32_t rack_highest_sack_thresh_seen = 0;
200 static uint32_t rack_highest_move_thresh_seen = 0;
201 static int32_t rack_enable_hw_pacing = 0; /* Due to CCSP keep it off by default */
202 static int32_t rack_hw_pace_extra_slots = 2;	/* 2 extra MSS time betweens */
203 static int32_t rack_hw_rate_caps = 1; /* 1; */
204 static int32_t rack_hw_rate_min = 0; /* 1500000;*/
205 static int32_t rack_hw_rate_to_low = 0; /* 1200000; */
206 static int32_t rack_hw_up_only = 1;
207 static int32_t rack_stats_gets_ms_rtt = 1;
208 static int32_t rack_prr_addbackmax = 2;
209 static int32_t rack_do_hystart = 0;
210 static int32_t rack_apply_rtt_with_reduced_conf = 0;
211 
212 static int32_t rack_pkt_delay = 1000;
213 static int32_t rack_send_a_lot_in_prr = 1;
214 static int32_t rack_min_to = 1000;	/* Number of microsecond  min timeout */
215 static int32_t rack_verbose_logging = 0;
216 static int32_t rack_ignore_data_after_close = 1;
217 static int32_t rack_enable_shared_cwnd = 1;
218 static int32_t rack_use_cmp_acks = 1;
219 static int32_t rack_use_fsb = 1;
220 static int32_t rack_use_rfo = 1;
221 static int32_t rack_use_rsm_rfo = 1;
222 static int32_t rack_max_abc_post_recovery = 2;
223 static int32_t rack_client_low_buf = 0;
224 static int32_t rack_dsack_std_based = 0x3;	/* bit field bit 1 sets rc_rack_tmr_std_based and bit 2 sets rc_rack_use_dsack */
225 #ifdef TCP_ACCOUNTING
226 static int32_t rack_tcp_accounting = 0;
227 #endif
228 static int32_t rack_limits_scwnd = 1;
229 static int32_t rack_enable_mqueue_for_nonpaced = 0;
230 static int32_t rack_disable_prr = 0;
231 static int32_t use_rack_rr = 1;
232 static int32_t rack_non_rxt_use_cr = 0; /* does a non-rxt in recovery use the configured rate (ss/ca)? */
233 static int32_t rack_persist_min = 250000;	/* 250usec */
234 static int32_t rack_persist_max = 2000000;	/* 2 Second in usec's */
235 static int32_t rack_sack_not_required = 1;	/* set to one to allow non-sack to use rack */
236 static int32_t rack_default_init_window = 0;	/* Use system default */
237 static int32_t rack_limit_time_with_srtt = 0;
238 static int32_t rack_autosndbuf_inc = 20;	/* In percentage form */
239 static int32_t rack_enobuf_hw_boost_mult = 2;	/* How many times the hw rate we boost slot using time_between */
240 static int32_t rack_enobuf_hw_max = 12000;	/* 12 ms in usecs */
241 static int32_t rack_enobuf_hw_min = 10000;	/* 10 ms in usecs */
242 static int32_t rack_hw_rwnd_factor = 2;		/* How many max_segs the rwnd must be before we hold off sending */
243 
244 /*
245  * Currently regular tcp has a rto_min of 30ms
246  * the backoff goes 12 times so that ends up
247  * being a total of 122.850 seconds before a
248  * connection is killed.
249  */
250 static uint32_t rack_def_data_window = 20;
251 static uint32_t rack_goal_bdp = 2;
252 static uint32_t rack_min_srtts = 1;
253 static uint32_t rack_min_measure_usec = 0;
254 static int32_t rack_tlp_min = 10000;	/* 10ms */
255 static int32_t rack_rto_min = 30000;	/* 30,000 usec same as main freebsd */
256 static int32_t rack_rto_max = 4000000;	/* 4 seconds in usec's */
257 static const int32_t rack_free_cache = 2;
258 static int32_t rack_hptsi_segments = 40;
259 static int32_t rack_rate_sample_method = USE_RTT_LOW;
260 static int32_t rack_pace_every_seg = 0;
261 static int32_t rack_delayed_ack_time = 40000;	/* 40ms in usecs */
262 static int32_t rack_slot_reduction = 4;
263 static int32_t rack_wma_divisor = 8;		/* For WMA calculation */
264 static int32_t rack_cwnd_block_ends_measure = 0;
265 static int32_t rack_rwnd_block_ends_measure = 0;
266 static int32_t rack_def_profile = 0;
267 
268 static int32_t rack_lower_cwnd_at_tlp = 0;
269 static int32_t rack_limited_retran = 0;
270 static int32_t rack_always_send_oldest = 0;
271 static int32_t rack_tlp_threshold_use = TLP_USE_TWO_ONE;
272 
273 static uint16_t rack_per_of_gp_ss = 250;	/* 250 % slow-start */
274 static uint16_t rack_per_of_gp_ca = 200;	/* 200 % congestion-avoidance */
275 static uint16_t rack_per_of_gp_rec = 200;	/* 200 % of bw */
276 
277 /* Probertt */
278 static uint16_t rack_per_of_gp_probertt = 60;	/* 60% of bw */
279 static uint16_t rack_per_of_gp_lowthresh = 40;	/* 40% is bottom */
280 static uint16_t rack_per_of_gp_probertt_reduce = 10; /* 10% reduction */
281 static uint16_t rack_atexit_prtt_hbp = 130;	/* Clamp to 130% on exit prtt if highly buffered path */
282 static uint16_t rack_atexit_prtt = 130;	/* Clamp to 100% on exit prtt if non highly buffered path */
283 
284 static uint32_t rack_max_drain_wait = 2;	/* How man gp srtt's before we give up draining */
285 static uint32_t rack_must_drain = 1;		/* How many GP srtt's we *must* wait */
286 static uint32_t rack_probertt_use_min_rtt_entry = 1;	/* Use the min to calculate the goal else gp_srtt */
287 static uint32_t rack_probertt_use_min_rtt_exit = 0;
288 static uint32_t rack_probe_rtt_sets_cwnd = 0;
289 static uint32_t rack_probe_rtt_safety_val = 2000000;	/* No more than 2 sec in probe-rtt */
290 static uint32_t rack_time_between_probertt = 9600000;	/* 9.6 sec in usecs */
291 static uint32_t rack_probertt_gpsrtt_cnt_mul = 0;	/* How many srtt periods does probe-rtt last top fraction */
292 static uint32_t rack_probertt_gpsrtt_cnt_div = 0;	/* How many srtt periods does probe-rtt last bottom fraction */
293 static uint32_t rack_min_probertt_hold = 40000;		/* Equal to delayed ack time */
294 static uint32_t rack_probertt_filter_life = 10000000;
295 static uint32_t rack_probertt_lower_within = 10;
296 static uint32_t rack_min_rtt_movement = 250000;	/* Must move at least 250ms (in microseconds)  to count as a lowering */
297 static int32_t rack_pace_one_seg = 0;		/* Shall we pace for less than 1.4Meg 1MSS at a time */
298 static int32_t rack_probertt_clear_is = 1;
299 static int32_t rack_max_drain_hbp = 1;		/* Extra drain times gpsrtt for highly buffered paths */
300 static int32_t rack_hbp_thresh = 3;		/* what is the divisor max_rtt/min_rtt to decided a hbp */
301 
302 /* Part of pacing */
303 static int32_t rack_max_per_above = 30;		/* When we go to increment stop if above 100+this% */
304 
305 /* Timely information */
306 /* Combine these two gives the range of 'no change' to bw */
307 /* ie the up/down provide the upper and lower bound */
308 static int32_t rack_gp_per_bw_mul_up = 2;	/* 2% */
309 static int32_t rack_gp_per_bw_mul_down = 4;	/* 4% */
310 static int32_t rack_gp_rtt_maxmul = 3;		/* 3 x maxmin */
311 static int32_t rack_gp_rtt_minmul = 1;		/* minrtt + (minrtt/mindiv) is lower rtt */
312 static int32_t rack_gp_rtt_mindiv = 4;		/* minrtt + (minrtt * minmul/mindiv) is lower rtt */
313 static int32_t rack_gp_decrease_per = 20;	/* 20% decrease in multiplier */
314 static int32_t rack_gp_increase_per = 2;	/* 2% increase in multiplier */
315 static int32_t rack_per_lower_bound = 50;	/* Don't allow to drop below this multiplier */
316 static int32_t rack_per_upper_bound_ss = 0;	/* Don't allow SS to grow above this */
317 static int32_t rack_per_upper_bound_ca = 0;	/* Don't allow CA to grow above this */
318 static int32_t rack_do_dyn_mul = 0;		/* Are the rack gp multipliers dynamic */
319 static int32_t rack_gp_no_rec_chg = 1;		/* Prohibit recovery from reducing it's multiplier */
320 static int32_t rack_timely_dec_clear = 6;	/* Do we clear decrement count at a value (6)? */
321 static int32_t rack_timely_max_push_rise = 3;	/* One round of pushing */
322 static int32_t rack_timely_max_push_drop = 3;	/* Three round of pushing */
323 static int32_t rack_timely_min_segs = 4;	/* 4 segment minimum */
324 static int32_t rack_use_max_for_nobackoff = 0;
325 static int32_t rack_timely_int_timely_only = 0;	/* do interim timely's only use the timely algo (no b/w changes)? */
326 static int32_t rack_timely_no_stopping = 0;
327 static int32_t rack_down_raise_thresh = 100;
328 static int32_t rack_req_segs = 1;
329 static uint64_t rack_bw_rate_cap = 0;
330 static uint32_t rack_trace_point_config = 0;
331 static uint32_t rack_trace_point_bb_mode = 4;
332 static int32_t rack_trace_point_count = 0;
333 
334 
335 /* Weird delayed ack mode */
336 static int32_t rack_use_imac_dack = 0;
337 /* Rack specific counters */
338 counter_u64_t rack_saw_enobuf;
339 counter_u64_t rack_saw_enobuf_hw;
340 counter_u64_t rack_saw_enetunreach;
341 counter_u64_t rack_persists_sends;
342 counter_u64_t rack_persists_acks;
343 counter_u64_t rack_persists_loss;
344 counter_u64_t rack_persists_lost_ends;
345 #ifdef INVARIANTS
346 counter_u64_t rack_adjust_map_bw;
347 #endif
348 /* Tail loss probe counters */
349 counter_u64_t rack_tlp_tot;
350 counter_u64_t rack_tlp_newdata;
351 counter_u64_t rack_tlp_retran;
352 counter_u64_t rack_tlp_retran_bytes;
353 counter_u64_t rack_to_tot;
354 counter_u64_t rack_hot_alloc;
355 counter_u64_t rack_to_alloc;
356 counter_u64_t rack_to_alloc_hard;
357 counter_u64_t rack_to_alloc_emerg;
358 counter_u64_t rack_to_alloc_limited;
359 counter_u64_t rack_alloc_limited_conns;
360 counter_u64_t rack_split_limited;
361 
362 counter_u64_t rack_multi_single_eq;
363 counter_u64_t rack_proc_non_comp_ack;
364 
365 counter_u64_t rack_fto_send;
366 counter_u64_t rack_fto_rsm_send;
367 counter_u64_t rack_nfto_resend;
368 counter_u64_t rack_non_fto_send;
369 counter_u64_t rack_extended_rfo;
370 
371 counter_u64_t rack_sack_proc_all;
372 counter_u64_t rack_sack_proc_short;
373 counter_u64_t rack_sack_proc_restart;
374 counter_u64_t rack_sack_attacks_detected;
375 counter_u64_t rack_sack_attacks_reversed;
376 counter_u64_t rack_sack_used_next_merge;
377 counter_u64_t rack_sack_splits;
378 counter_u64_t rack_sack_used_prev_merge;
379 counter_u64_t rack_sack_skipped_acked;
380 counter_u64_t rack_ack_total;
381 counter_u64_t rack_express_sack;
382 counter_u64_t rack_sack_total;
383 counter_u64_t rack_move_none;
384 counter_u64_t rack_move_some;
385 
386 counter_u64_t rack_input_idle_reduces;
387 counter_u64_t rack_collapsed_win;
388 counter_u64_t rack_collapsed_win_seen;
389 counter_u64_t rack_collapsed_win_rxt;
390 counter_u64_t rack_collapsed_win_rxt_bytes;
391 counter_u64_t rack_try_scwnd;
392 counter_u64_t rack_hw_pace_init_fail;
393 counter_u64_t rack_hw_pace_lost;
394 
395 counter_u64_t rack_out_size[TCP_MSS_ACCT_SIZE];
396 counter_u64_t rack_opts_arry[RACK_OPTS_SIZE];
397 
398 
399 #define	RACK_REXMTVAL(tp) max(rack_rto_min, ((tp)->t_srtt + ((tp)->t_rttvar << 2)))
400 
401 #define	RACK_TCPT_RANGESET(tv, value, tvmin, tvmax, slop) do {	\
402 	(tv) = (value) + slop;	 \
403 	if ((u_long)(tv) < (u_long)(tvmin)) \
404 		(tv) = (tvmin); \
405 	if ((u_long)(tv) > (u_long)(tvmax)) \
406 		(tv) = (tvmax); \
407 } while (0)
408 
409 static void
410 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick,  int event, int line);
411 
412 static int
413 rack_process_ack(struct mbuf *m, struct tcphdr *th,
414     struct socket *so, struct tcpcb *tp, struct tcpopt *to,
415     uint32_t tiwin, int32_t tlen, int32_t * ofia, int32_t thflags, int32_t * ret_val);
416 static int
417 rack_process_data(struct mbuf *m, struct tcphdr *th,
418     struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
419     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt);
420 static void
421 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack,
422    uint32_t th_ack, uint16_t nsegs, uint16_t type, int32_t recovery);
423 static struct rack_sendmap *rack_alloc(struct tcp_rack *rack);
424 static struct rack_sendmap *rack_alloc_limit(struct tcp_rack *rack,
425     uint8_t limit_type);
426 static struct rack_sendmap *
427 rack_check_recovery_mode(struct tcpcb *tp,
428     uint32_t tsused);
429 static void
430 rack_cong_signal(struct tcpcb *tp,
431 		 uint32_t type, uint32_t ack, int );
432 static void rack_counter_destroy(void);
433 static int
434 rack_ctloutput(struct inpcb *inp, struct sockopt *sopt);
435 static int32_t rack_ctor(void *mem, int32_t size, void *arg, int32_t how);
436 static void
437 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line, uint64_t *fill_override);
438 static void
439 rack_do_segment(struct mbuf *m, struct tcphdr *th,
440     struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
441     uint8_t iptos);
442 static void rack_dtor(void *mem, int32_t size, void *arg);
443 static void
444 rack_log_alt_to_to_cancel(struct tcp_rack *rack,
445     uint32_t flex1, uint32_t flex2,
446     uint32_t flex3, uint32_t flex4,
447     uint32_t flex5, uint32_t flex6,
448     uint16_t flex7, uint8_t mod);
449 
450 static void
451 rack_log_pacing_delay_calc(struct tcp_rack *rack, uint32_t len, uint32_t slot,
452    uint64_t bw_est, uint64_t bw, uint64_t len_time, int method, int line,
453    struct rack_sendmap *rsm, uint8_t quality);
454 static struct rack_sendmap *
455 rack_find_high_nonack(struct tcp_rack *rack,
456     struct rack_sendmap *rsm);
457 static struct rack_sendmap *rack_find_lowest_rsm(struct tcp_rack *rack);
458 static void rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm);
459 static void rack_fini(struct tcpcb *tp, int32_t tcb_is_purged);
460 static int rack_get_sockopt(struct inpcb *inp, struct sockopt *sopt);
461 static void
462 rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
463 			    tcp_seq th_ack, int line, uint8_t quality);
464 static uint32_t
465 rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss);
466 static int32_t rack_handoff_ok(struct tcpcb *tp);
467 static int32_t rack_init(struct tcpcb *tp);
468 static void rack_init_sysctls(void);
469 static void
470 rack_log_ack(struct tcpcb *tp, struct tcpopt *to,
471     struct tcphdr *th, int entered_rec, int dup_ack_struck);
472 static void
473 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
474     uint32_t seq_out, uint16_t th_flags, int32_t err, uint64_t ts,
475     struct rack_sendmap *hintrsm, uint16_t add_flags, struct mbuf *s_mb, uint32_t s_moff, int hw_tls);
476 
477 static void
478 rack_log_sack_passed(struct tcpcb *tp, struct tcp_rack *rack,
479     struct rack_sendmap *rsm);
480 static void rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm);
481 static int32_t rack_output(struct tcpcb *tp);
482 
483 static uint32_t
484 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack,
485     struct sackblk *sack, struct tcpopt *to, struct rack_sendmap **prsm,
486     uint32_t cts, int *moved_two);
487 static void rack_post_recovery(struct tcpcb *tp, uint32_t th_seq);
488 static void rack_remxt_tmr(struct tcpcb *tp);
489 static int rack_set_sockopt(struct inpcb *inp, struct sockopt *sopt);
490 static void rack_set_state(struct tcpcb *tp, struct tcp_rack *rack);
491 static int32_t rack_stopall(struct tcpcb *tp);
492 static void rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line);
493 static void rack_timer_stop(struct tcpcb *tp, uint32_t timer_type);
494 static uint32_t
495 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
496     struct rack_sendmap *rsm, uint64_t ts, int32_t * lenp, uint16_t add_flag);
497 static void
498 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
499     struct rack_sendmap *rsm, uint64_t ts, uint16_t add_flag);
500 static int
501 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
502     struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack);
503 static int32_t tcp_addrack(module_t mod, int32_t type, void *data);
504 static int
505 rack_do_close_wait(struct mbuf *m, struct tcphdr *th,
506     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
507     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
508 static int
509 rack_do_closing(struct mbuf *m, struct tcphdr *th,
510     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
511     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
512 static int
513 rack_do_established(struct mbuf *m, struct tcphdr *th,
514     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
515     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
516 static int
517 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th,
518     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
519     int32_t tlen, uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos);
520 static int
521 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th,
522     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
523     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
524 static int
525 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th,
526     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
527     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
528 static int
529 rack_do_lastack(struct mbuf *m, struct tcphdr *th,
530     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
531     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
532 static int
533 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th,
534     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
535     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
536 static int
537 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th,
538     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
539     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
540 struct rack_sendmap *
541 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack,
542     uint32_t tsused);
543 static void tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt,
544     uint32_t len, uint32_t us_tim, int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt);
545 static void
546      tcp_rack_partialack(struct tcpcb *tp);
547 static int
548 rack_set_profile(struct tcp_rack *rack, int prof);
549 static void
550 rack_apply_deferred_options(struct tcp_rack *rack);
551 
552 int32_t rack_clear_counter=0;
553 
554 static inline void
555 rack_trace_point(struct tcp_rack *rack, int num)
556 {
557 	if (((rack_trace_point_config == num)  ||
558 	     (rack_trace_point_config = 0xffffffff)) &&
559 	    (rack_trace_point_bb_mode != 0) &&
560 	    (rack_trace_point_count > 0) &&
561 	    (rack->rc_tp->t_logstate == 0)) {
562 		int res;
563 		res = atomic_fetchadd_int(&rack_trace_point_count, -1);
564 		if (res > 0) {
565 			rack->rc_tp->t_logstate = rack_trace_point_bb_mode;
566 		} else {
567 			/* Loss a race assure its zero now */
568 			rack_trace_point_count = 0;
569 		}
570 	}
571 }
572 
573 static void
574 rack_set_cc_pacing(struct tcp_rack *rack)
575 {
576 	struct sockopt sopt;
577 	struct cc_newreno_opts opt;
578 	struct newreno old, *ptr;
579 	struct tcpcb *tp;
580 	int error;
581 
582 	if (rack->rc_pacing_cc_set)
583 		return;
584 
585 	tp = rack->rc_tp;
586 	if (tp->t_cc == NULL) {
587 		/* Tcb is leaving */
588 		return;
589 	}
590 	rack->rc_pacing_cc_set = 1;
591 	if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0) {
592 		/* Not new-reno we can't play games with beta! */
593 		goto out;
594 	}
595 	ptr = ((struct newreno *)tp->t_ccv.cc_data);
596 	if (CC_ALGO(tp)->ctl_output == NULL)  {
597 		/* Huh, why does new_reno no longer have a set function? */
598 		goto out;
599 	}
600 	if (ptr == NULL) {
601 		/* Just the default values */
602 		old.beta = V_newreno_beta_ecn;
603 		old.beta_ecn = V_newreno_beta_ecn;
604 		old.newreno_flags = 0;
605 	} else {
606 		old.beta = ptr->beta;
607 		old.beta_ecn = ptr->beta_ecn;
608 		old.newreno_flags = ptr->newreno_flags;
609 	}
610 	sopt.sopt_valsize = sizeof(struct cc_newreno_opts);
611 	sopt.sopt_dir = SOPT_SET;
612 	opt.name = CC_NEWRENO_BETA;
613 	opt.val = rack->r_ctl.rc_saved_beta.beta;
614 	error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
615 	if (error)  {
616 		goto out;
617 	}
618 	/*
619 	 * Hack alert we need to set in our newreno_flags
620 	 * so that Abe behavior is also applied.
621 	 */
622 	((struct newreno *)tp->t_ccv.cc_data)->newreno_flags |= CC_NEWRENO_BETA_ECN_ENABLED;
623 	opt.name = CC_NEWRENO_BETA_ECN;
624 	opt.val = rack->r_ctl.rc_saved_beta.beta_ecn;
625 	error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
626 	if (error) {
627 		goto out;
628 	}
629 	/* Save off the original values for restoral */
630 	memcpy(&rack->r_ctl.rc_saved_beta, &old, sizeof(struct newreno));
631 out:
632 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
633 		union tcp_log_stackspecific log;
634 		struct timeval tv;
635 
636 		ptr = ((struct newreno *)tp->t_ccv.cc_data);
637 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
638 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
639 		if (ptr) {
640 			log.u_bbr.flex1 = ptr->beta;
641 			log.u_bbr.flex2 = ptr->beta_ecn;
642 			log.u_bbr.flex3 = ptr->newreno_flags;
643 		}
644 		log.u_bbr.flex4 = rack->r_ctl.rc_saved_beta.beta;
645 		log.u_bbr.flex5 = rack->r_ctl.rc_saved_beta.beta_ecn;
646 		log.u_bbr.flex6 = rack->r_ctl.rc_saved_beta.newreno_flags;
647 		log.u_bbr.flex7 = rack->gp_ready;
648 		log.u_bbr.flex7 <<= 1;
649 		log.u_bbr.flex7 |= rack->use_fixed_rate;
650 		log.u_bbr.flex7 <<= 1;
651 		log.u_bbr.flex7 |= rack->rc_pacing_cc_set;
652 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
653 		log.u_bbr.flex8 = 3;
654 		tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, error,
655 			       0, &log, false, NULL, NULL, 0, &tv);
656 	}
657 }
658 
659 static void
660 rack_undo_cc_pacing(struct tcp_rack *rack)
661 {
662 	struct newreno old, *ptr;
663 	struct tcpcb *tp;
664 
665 	if (rack->rc_pacing_cc_set == 0)
666 		return;
667 	tp = rack->rc_tp;
668 	rack->rc_pacing_cc_set = 0;
669 	if (tp->t_cc == NULL)
670 		/* Tcb is leaving */
671 		return;
672 	if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0) {
673 		/* Not new-reno nothing to do! */
674 		return;
675 	}
676 	ptr = ((struct newreno *)tp->t_ccv.cc_data);
677 	if (ptr == NULL) {
678 		/*
679 		 * This happens at rack_fini() if the
680 		 * cc module gets freed on us. In that
681 		 * case we loose our "new" settings but
682 		 * thats ok, since the tcb is going away anyway.
683 		 */
684 		return;
685 	}
686 	/* Grab out our set values */
687 	memcpy(&old, ptr, sizeof(struct newreno));
688 	/* Copy back in the original values */
689 	memcpy(ptr, &rack->r_ctl.rc_saved_beta, sizeof(struct newreno));
690 	/* Now save back the values we had set in (for when pacing is restored) */
691 	memcpy(&rack->r_ctl.rc_saved_beta, &old, sizeof(struct newreno));
692 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
693 		union tcp_log_stackspecific log;
694 		struct timeval tv;
695 
696 		ptr = ((struct newreno *)tp->t_ccv.cc_data);
697 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
698 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
699 		log.u_bbr.flex1 = ptr->beta;
700 		log.u_bbr.flex2 = ptr->beta_ecn;
701 		log.u_bbr.flex3 = ptr->newreno_flags;
702 		log.u_bbr.flex4 = rack->r_ctl.rc_saved_beta.beta;
703 		log.u_bbr.flex5 = rack->r_ctl.rc_saved_beta.beta_ecn;
704 		log.u_bbr.flex6 = rack->r_ctl.rc_saved_beta.newreno_flags;
705 		log.u_bbr.flex7 = rack->gp_ready;
706 		log.u_bbr.flex7 <<= 1;
707 		log.u_bbr.flex7 |= rack->use_fixed_rate;
708 		log.u_bbr.flex7 <<= 1;
709 		log.u_bbr.flex7 |= rack->rc_pacing_cc_set;
710 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
711 		log.u_bbr.flex8 = 4;
712 		tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
713 			       0, &log, false, NULL, NULL, 0, &tv);
714 	}
715 }
716 
717 #ifdef NETFLIX_PEAKRATE
718 static inline void
719 rack_update_peakrate_thr(struct tcpcb *tp)
720 {
721 	/* Keep in mind that t_maxpeakrate is in B/s. */
722 	uint64_t peak;
723 	peak = uqmax((tp->t_maxseg * 2),
724 		     (((uint64_t)tp->t_maxpeakrate * (uint64_t)(tp->t_srtt)) / (uint64_t)HPTS_USEC_IN_SEC));
725 	tp->t_peakrate_thr = (uint32_t)uqmin(peak, UINT32_MAX);
726 }
727 #endif
728 
729 static int
730 sysctl_rack_clear(SYSCTL_HANDLER_ARGS)
731 {
732 	uint32_t stat;
733 	int32_t error;
734 
735 	error = SYSCTL_OUT(req, &rack_clear_counter, sizeof(uint32_t));
736 	if (error || req->newptr == NULL)
737 		return error;
738 
739 	error = SYSCTL_IN(req, &stat, sizeof(uint32_t));
740 	if (error)
741 		return (error);
742 	if (stat == 1) {
743 #ifdef INVARIANTS
744 		printf("Clearing RACK counters\n");
745 #endif
746 		counter_u64_zero(rack_tlp_tot);
747 		counter_u64_zero(rack_tlp_newdata);
748 		counter_u64_zero(rack_tlp_retran);
749 		counter_u64_zero(rack_tlp_retran_bytes);
750 		counter_u64_zero(rack_to_tot);
751 		counter_u64_zero(rack_saw_enobuf);
752 		counter_u64_zero(rack_saw_enobuf_hw);
753 		counter_u64_zero(rack_saw_enetunreach);
754 		counter_u64_zero(rack_persists_sends);
755 		counter_u64_zero(rack_persists_acks);
756 		counter_u64_zero(rack_persists_loss);
757 		counter_u64_zero(rack_persists_lost_ends);
758 #ifdef INVARIANTS
759 		counter_u64_zero(rack_adjust_map_bw);
760 #endif
761 		counter_u64_zero(rack_to_alloc_hard);
762 		counter_u64_zero(rack_to_alloc_emerg);
763 		counter_u64_zero(rack_sack_proc_all);
764 		counter_u64_zero(rack_fto_send);
765 		counter_u64_zero(rack_fto_rsm_send);
766 		counter_u64_zero(rack_extended_rfo);
767 		counter_u64_zero(rack_hw_pace_init_fail);
768 		counter_u64_zero(rack_hw_pace_lost);
769 		counter_u64_zero(rack_non_fto_send);
770 		counter_u64_zero(rack_nfto_resend);
771 		counter_u64_zero(rack_sack_proc_short);
772 		counter_u64_zero(rack_sack_proc_restart);
773 		counter_u64_zero(rack_to_alloc);
774 		counter_u64_zero(rack_to_alloc_limited);
775 		counter_u64_zero(rack_alloc_limited_conns);
776 		counter_u64_zero(rack_split_limited);
777 		counter_u64_zero(rack_multi_single_eq);
778 		counter_u64_zero(rack_proc_non_comp_ack);
779 		counter_u64_zero(rack_sack_attacks_detected);
780 		counter_u64_zero(rack_sack_attacks_reversed);
781 		counter_u64_zero(rack_sack_used_next_merge);
782 		counter_u64_zero(rack_sack_used_prev_merge);
783 		counter_u64_zero(rack_sack_splits);
784 		counter_u64_zero(rack_sack_skipped_acked);
785 		counter_u64_zero(rack_ack_total);
786 		counter_u64_zero(rack_express_sack);
787 		counter_u64_zero(rack_sack_total);
788 		counter_u64_zero(rack_move_none);
789 		counter_u64_zero(rack_move_some);
790 		counter_u64_zero(rack_try_scwnd);
791 		counter_u64_zero(rack_collapsed_win);
792 		counter_u64_zero(rack_collapsed_win_rxt);
793 		counter_u64_zero(rack_collapsed_win_seen);
794 		counter_u64_zero(rack_collapsed_win_rxt_bytes);
795 	}
796 	rack_clear_counter = 0;
797 	return (0);
798 }
799 
800 static void
801 rack_init_sysctls(void)
802 {
803 	struct sysctl_oid *rack_counters;
804 	struct sysctl_oid *rack_attack;
805 	struct sysctl_oid *rack_pacing;
806 	struct sysctl_oid *rack_timely;
807 	struct sysctl_oid *rack_timers;
808 	struct sysctl_oid *rack_tlp;
809 	struct sysctl_oid *rack_misc;
810 	struct sysctl_oid *rack_features;
811 	struct sysctl_oid *rack_measure;
812 	struct sysctl_oid *rack_probertt;
813 	struct sysctl_oid *rack_hw_pacing;
814 	struct sysctl_oid *rack_tracepoint;
815 
816 	rack_attack = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
817 	    SYSCTL_CHILDREN(rack_sysctl_root),
818 	    OID_AUTO,
819 	    "sack_attack",
820 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
821 	    "Rack Sack Attack Counters and Controls");
822 	rack_counters = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
823 	    SYSCTL_CHILDREN(rack_sysctl_root),
824 	    OID_AUTO,
825 	    "stats",
826 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
827 	    "Rack Counters");
828 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
829 	    SYSCTL_CHILDREN(rack_sysctl_root),
830 	    OID_AUTO, "rate_sample_method", CTLFLAG_RW,
831 	    &rack_rate_sample_method , USE_RTT_LOW,
832 	    "What method should we use for rate sampling 0=high, 1=low ");
833 	/* Probe rtt related controls */
834 	rack_probertt = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
835 	    SYSCTL_CHILDREN(rack_sysctl_root),
836 	    OID_AUTO,
837 	    "probertt",
838 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
839 	    "ProbeRTT related Controls");
840 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
841 	    SYSCTL_CHILDREN(rack_probertt),
842 	    OID_AUTO, "exit_per_hpb", CTLFLAG_RW,
843 	    &rack_atexit_prtt_hbp, 130,
844 	    "What percentage above goodput do we clamp CA/SS to at exit on high-BDP path 110%");
845 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
846 	    SYSCTL_CHILDREN(rack_probertt),
847 	    OID_AUTO, "exit_per_nonhpb", CTLFLAG_RW,
848 	    &rack_atexit_prtt, 130,
849 	    "What percentage above goodput do we clamp CA/SS to at exit on a non high-BDP path 100%");
850 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
851 	    SYSCTL_CHILDREN(rack_probertt),
852 	    OID_AUTO, "gp_per_mul", CTLFLAG_RW,
853 	    &rack_per_of_gp_probertt, 60,
854 	    "What percentage of goodput do we pace at in probertt");
855 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
856 	    SYSCTL_CHILDREN(rack_probertt),
857 	    OID_AUTO, "gp_per_reduce", CTLFLAG_RW,
858 	    &rack_per_of_gp_probertt_reduce, 10,
859 	    "What percentage of goodput do we reduce every gp_srtt");
860 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
861 	    SYSCTL_CHILDREN(rack_probertt),
862 	    OID_AUTO, "gp_per_low", CTLFLAG_RW,
863 	    &rack_per_of_gp_lowthresh, 40,
864 	    "What percentage of goodput do we allow the multiplier to fall to");
865 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
866 	    SYSCTL_CHILDREN(rack_probertt),
867 	    OID_AUTO, "time_between", CTLFLAG_RW,
868 	    & rack_time_between_probertt, 96000000,
869 	    "How many useconds between the lowest rtt falling must past before we enter probertt");
870 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
871 	    SYSCTL_CHILDREN(rack_probertt),
872 	    OID_AUTO, "safety", CTLFLAG_RW,
873 	    &rack_probe_rtt_safety_val, 2000000,
874 	    "If not zero, provides a maximum usecond that you can stay in probertt (2sec = 2000000)");
875 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
876 	    SYSCTL_CHILDREN(rack_probertt),
877 	    OID_AUTO, "sets_cwnd", CTLFLAG_RW,
878 	    &rack_probe_rtt_sets_cwnd, 0,
879 	    "Do we set the cwnd too (if always_lower is on)");
880 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
881 	    SYSCTL_CHILDREN(rack_probertt),
882 	    OID_AUTO, "maxdrainsrtts", CTLFLAG_RW,
883 	    &rack_max_drain_wait, 2,
884 	    "Maximum number of gp_srtt's to hold in drain waiting for flight to reach goal");
885 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
886 	    SYSCTL_CHILDREN(rack_probertt),
887 	    OID_AUTO, "mustdrainsrtts", CTLFLAG_RW,
888 	    &rack_must_drain, 1,
889 	    "We must drain this many gp_srtt's waiting for flight to reach goal");
890 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
891 	    SYSCTL_CHILDREN(rack_probertt),
892 	    OID_AUTO, "goal_use_min_entry", CTLFLAG_RW,
893 	    &rack_probertt_use_min_rtt_entry, 1,
894 	    "Should we use the min-rtt to calculate the goal rtt (else gp_srtt) at entry");
895 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
896 	    SYSCTL_CHILDREN(rack_probertt),
897 	    OID_AUTO, "goal_use_min_exit", CTLFLAG_RW,
898 	    &rack_probertt_use_min_rtt_exit, 0,
899 	    "How to set cwnd at exit, 0 - dynamic, 1 - use min-rtt, 2 - use curgprtt, 3 - entry gp-rtt");
900 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
901 	    SYSCTL_CHILDREN(rack_probertt),
902 	    OID_AUTO, "length_div", CTLFLAG_RW,
903 	    &rack_probertt_gpsrtt_cnt_div, 0,
904 	    "How many recent goodput srtt periods plus hold tim does probertt last (bottom of fraction)");
905 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
906 	    SYSCTL_CHILDREN(rack_probertt),
907 	    OID_AUTO, "length_mul", CTLFLAG_RW,
908 	    &rack_probertt_gpsrtt_cnt_mul, 0,
909 	    "How many recent goodput srtt periods plus hold tim does probertt last (top of fraction)");
910 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
911 	    SYSCTL_CHILDREN(rack_probertt),
912 	    OID_AUTO, "holdtim_at_target", CTLFLAG_RW,
913 	    &rack_min_probertt_hold, 200000,
914 	    "What is the minimum time we hold probertt at target");
915 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
916 	    SYSCTL_CHILDREN(rack_probertt),
917 	    OID_AUTO, "filter_life", CTLFLAG_RW,
918 	    &rack_probertt_filter_life, 10000000,
919 	    "What is the time for the filters life in useconds");
920 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
921 	    SYSCTL_CHILDREN(rack_probertt),
922 	    OID_AUTO, "lower_within", CTLFLAG_RW,
923 	    &rack_probertt_lower_within, 10,
924 	    "If the rtt goes lower within this percentage of the time, go into probe-rtt");
925 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
926 	    SYSCTL_CHILDREN(rack_probertt),
927 	    OID_AUTO, "must_move", CTLFLAG_RW,
928 	    &rack_min_rtt_movement, 250,
929 	    "How much is the minimum movement in rtt to count as a drop for probertt purposes");
930 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
931 	    SYSCTL_CHILDREN(rack_probertt),
932 	    OID_AUTO, "clear_is_cnts", CTLFLAG_RW,
933 	    &rack_probertt_clear_is, 1,
934 	    "Do we clear I/S counts on exiting probe-rtt");
935 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
936 	    SYSCTL_CHILDREN(rack_probertt),
937 	    OID_AUTO, "hbp_extra_drain", CTLFLAG_RW,
938 	    &rack_max_drain_hbp, 1,
939 	    "How many extra drain gpsrtt's do we get in highly buffered paths");
940 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
941 	    SYSCTL_CHILDREN(rack_probertt),
942 	    OID_AUTO, "hbp_threshold", CTLFLAG_RW,
943 	    &rack_hbp_thresh, 3,
944 	    "We are highly buffered if min_rtt_seen / max_rtt_seen > this-threshold");
945 
946 	rack_tracepoint = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
947 	    SYSCTL_CHILDREN(rack_sysctl_root),
948 	    OID_AUTO,
949 	    "tp",
950 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
951 	    "Rack tracepoint facility");
952 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
953 	    SYSCTL_CHILDREN(rack_tracepoint),
954 	    OID_AUTO, "number", CTLFLAG_RW,
955 	    &rack_trace_point_config, 0,
956 	    "What is the trace point number to activate (0=none, 0xffffffff = all)?");
957 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
958 	    SYSCTL_CHILDREN(rack_tracepoint),
959 	    OID_AUTO, "bbmode", CTLFLAG_RW,
960 	    &rack_trace_point_bb_mode, 4,
961 	    "What is BB logging mode that is activated?");
962 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
963 	    SYSCTL_CHILDREN(rack_tracepoint),
964 	    OID_AUTO, "count", CTLFLAG_RW,
965 	    &rack_trace_point_count, 0,
966 	    "How many connections will have BB logging turned on that hit the tracepoint?");
967 	/* Pacing related sysctls */
968 	rack_pacing = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
969 	    SYSCTL_CHILDREN(rack_sysctl_root),
970 	    OID_AUTO,
971 	    "pacing",
972 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
973 	    "Pacing related Controls");
974 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
975 	    SYSCTL_CHILDREN(rack_pacing),
976 	    OID_AUTO, "max_pace_over", CTLFLAG_RW,
977 	    &rack_max_per_above, 30,
978 	    "What is the maximum allowable percentage that we can pace above (so 30 = 130% of our goal)");
979 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
980 	    SYSCTL_CHILDREN(rack_pacing),
981 	    OID_AUTO, "pace_to_one", CTLFLAG_RW,
982 	    &rack_pace_one_seg, 0,
983 	    "Do we allow low b/w pacing of 1MSS instead of two");
984 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
985 	    SYSCTL_CHILDREN(rack_pacing),
986 	    OID_AUTO, "limit_wsrtt", CTLFLAG_RW,
987 	    &rack_limit_time_with_srtt, 0,
988 	    "Do we limit pacing time based on srtt");
989 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
990 	    SYSCTL_CHILDREN(rack_pacing),
991 	    OID_AUTO, "init_win", CTLFLAG_RW,
992 	    &rack_default_init_window, 0,
993 	    "Do we have a rack initial window 0 = system default");
994 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
995 	    SYSCTL_CHILDREN(rack_pacing),
996 	    OID_AUTO, "gp_per_ss", CTLFLAG_RW,
997 	    &rack_per_of_gp_ss, 250,
998 	    "If non zero, what percentage of goodput to pace at in slow start");
999 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1000 	    SYSCTL_CHILDREN(rack_pacing),
1001 	    OID_AUTO, "gp_per_ca", CTLFLAG_RW,
1002 	    &rack_per_of_gp_ca, 150,
1003 	    "If non zero, what percentage of goodput to pace at in congestion avoidance");
1004 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1005 	    SYSCTL_CHILDREN(rack_pacing),
1006 	    OID_AUTO, "gp_per_rec", CTLFLAG_RW,
1007 	    &rack_per_of_gp_rec, 200,
1008 	    "If non zero, what percentage of goodput to pace at in recovery");
1009 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1010 	    SYSCTL_CHILDREN(rack_pacing),
1011 	    OID_AUTO, "pace_max_seg", CTLFLAG_RW,
1012 	    &rack_hptsi_segments, 40,
1013 	    "What size is the max for TSO segments in pacing and burst mitigation");
1014 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1015 	    SYSCTL_CHILDREN(rack_pacing),
1016 	    OID_AUTO, "burst_reduces", CTLFLAG_RW,
1017 	    &rack_slot_reduction, 4,
1018 	    "When doing only burst mitigation what is the reduce divisor");
1019 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1020 	    SYSCTL_CHILDREN(rack_sysctl_root),
1021 	    OID_AUTO, "use_pacing", CTLFLAG_RW,
1022 	    &rack_pace_every_seg, 0,
1023 	    "If set we use pacing, if clear we use only the original burst mitigation");
1024 	SYSCTL_ADD_U64(&rack_sysctl_ctx,
1025 	    SYSCTL_CHILDREN(rack_pacing),
1026 	    OID_AUTO, "rate_cap", CTLFLAG_RW,
1027 	    &rack_bw_rate_cap, 0,
1028 	    "If set we apply this value to the absolute rate cap used by pacing");
1029 	SYSCTL_ADD_U8(&rack_sysctl_ctx,
1030 	    SYSCTL_CHILDREN(rack_sysctl_root),
1031 	    OID_AUTO, "req_measure_cnt", CTLFLAG_RW,
1032 	    &rack_req_measurements, 1,
1033 	    "If doing dynamic pacing, how many measurements must be in before we start pacing?");
1034 	/* Hardware pacing */
1035 	rack_hw_pacing = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1036 	    SYSCTL_CHILDREN(rack_sysctl_root),
1037 	    OID_AUTO,
1038 	    "hdwr_pacing",
1039 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1040 	    "Pacing related Controls");
1041 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1042 	    SYSCTL_CHILDREN(rack_hw_pacing),
1043 	    OID_AUTO, "rwnd_factor", CTLFLAG_RW,
1044 	    &rack_hw_rwnd_factor, 2,
1045 	    "How many times does snd_wnd need to be bigger than pace_max_seg so we will hold off and get more acks?");
1046 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1047 	    SYSCTL_CHILDREN(rack_hw_pacing),
1048 	    OID_AUTO, "pace_enobuf_mult", CTLFLAG_RW,
1049 	    &rack_enobuf_hw_boost_mult, 2,
1050 	    "By how many time_betweens should we boost the pacing time if we see a ENOBUFS?");
1051 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1052 	    SYSCTL_CHILDREN(rack_hw_pacing),
1053 	    OID_AUTO, "pace_enobuf_max", CTLFLAG_RW,
1054 	    &rack_enobuf_hw_max, 2,
1055 	    "What is the max boost the pacing time if we see a ENOBUFS?");
1056 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1057 	    SYSCTL_CHILDREN(rack_hw_pacing),
1058 	    OID_AUTO, "pace_enobuf_min", CTLFLAG_RW,
1059 	    &rack_enobuf_hw_min, 2,
1060 	    "What is the min boost the pacing time if we see a ENOBUFS?");
1061 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1062 	    SYSCTL_CHILDREN(rack_hw_pacing),
1063 	    OID_AUTO, "enable", CTLFLAG_RW,
1064 	    &rack_enable_hw_pacing, 0,
1065 	    "Should RACK attempt to use hw pacing?");
1066 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1067 	    SYSCTL_CHILDREN(rack_hw_pacing),
1068 	    OID_AUTO, "rate_cap", CTLFLAG_RW,
1069 	    &rack_hw_rate_caps, 1,
1070 	    "Does the highest hardware pacing rate cap the rate we will send at??");
1071 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1072 	    SYSCTL_CHILDREN(rack_hw_pacing),
1073 	    OID_AUTO, "rate_min", CTLFLAG_RW,
1074 	    &rack_hw_rate_min, 0,
1075 	    "Do we need a minimum estimate of this many bytes per second in order to engage hw pacing?");
1076 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1077 	    SYSCTL_CHILDREN(rack_hw_pacing),
1078 	    OID_AUTO, "rate_to_low", CTLFLAG_RW,
1079 	    &rack_hw_rate_to_low, 0,
1080 	    "If we fall below this rate, dis-engage hw pacing?");
1081 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1082 	    SYSCTL_CHILDREN(rack_hw_pacing),
1083 	    OID_AUTO, "up_only", CTLFLAG_RW,
1084 	    &rack_hw_up_only, 1,
1085 	    "Do we allow hw pacing to lower the rate selected?");
1086 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1087 	    SYSCTL_CHILDREN(rack_hw_pacing),
1088 	    OID_AUTO, "extra_mss_precise", CTLFLAG_RW,
1089 	    &rack_hw_pace_extra_slots, 2,
1090 	    "If the rates between software and hardware match precisely how many extra time_betweens do we get?");
1091 	rack_timely = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1092 	    SYSCTL_CHILDREN(rack_sysctl_root),
1093 	    OID_AUTO,
1094 	    "timely",
1095 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1096 	    "Rack Timely RTT Controls");
1097 	/* Timely based GP dynmics */
1098 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1099 	    SYSCTL_CHILDREN(rack_timely),
1100 	    OID_AUTO, "upper", CTLFLAG_RW,
1101 	    &rack_gp_per_bw_mul_up, 2,
1102 	    "Rack timely upper range for equal b/w (in percentage)");
1103 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1104 	    SYSCTL_CHILDREN(rack_timely),
1105 	    OID_AUTO, "lower", CTLFLAG_RW,
1106 	    &rack_gp_per_bw_mul_down, 4,
1107 	    "Rack timely lower range for equal b/w (in percentage)");
1108 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1109 	    SYSCTL_CHILDREN(rack_timely),
1110 	    OID_AUTO, "rtt_max_mul", CTLFLAG_RW,
1111 	    &rack_gp_rtt_maxmul, 3,
1112 	    "Rack timely multiplier of lowest rtt for rtt_max");
1113 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1114 	    SYSCTL_CHILDREN(rack_timely),
1115 	    OID_AUTO, "rtt_min_div", CTLFLAG_RW,
1116 	    &rack_gp_rtt_mindiv, 4,
1117 	    "Rack timely divisor used for rtt + (rtt * mul/divisor) for check for lower rtt");
1118 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1119 	    SYSCTL_CHILDREN(rack_timely),
1120 	    OID_AUTO, "rtt_min_mul", CTLFLAG_RW,
1121 	    &rack_gp_rtt_minmul, 1,
1122 	    "Rack timely multiplier used for rtt + (rtt * mul/divisor) for check for lower rtt");
1123 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1124 	    SYSCTL_CHILDREN(rack_timely),
1125 	    OID_AUTO, "decrease", CTLFLAG_RW,
1126 	    &rack_gp_decrease_per, 20,
1127 	    "Rack timely decrease percentage of our GP multiplication factor");
1128 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1129 	    SYSCTL_CHILDREN(rack_timely),
1130 	    OID_AUTO, "increase", CTLFLAG_RW,
1131 	    &rack_gp_increase_per, 2,
1132 	    "Rack timely increase perentage of our GP multiplication factor");
1133 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1134 	    SYSCTL_CHILDREN(rack_timely),
1135 	    OID_AUTO, "lowerbound", CTLFLAG_RW,
1136 	    &rack_per_lower_bound, 50,
1137 	    "Rack timely lowest percentage we allow GP multiplier to fall to");
1138 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1139 	    SYSCTL_CHILDREN(rack_timely),
1140 	    OID_AUTO, "upperboundss", CTLFLAG_RW,
1141 	    &rack_per_upper_bound_ss, 0,
1142 	    "Rack timely highest percentage we allow GP multiplier in SS to raise to (0 is no upperbound)");
1143 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1144 	    SYSCTL_CHILDREN(rack_timely),
1145 	    OID_AUTO, "upperboundca", CTLFLAG_RW,
1146 	    &rack_per_upper_bound_ca, 0,
1147 	    "Rack timely highest percentage we allow GP multiplier to CA raise to (0 is no upperbound)");
1148 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1149 	    SYSCTL_CHILDREN(rack_timely),
1150 	    OID_AUTO, "dynamicgp", CTLFLAG_RW,
1151 	    &rack_do_dyn_mul, 0,
1152 	    "Rack timely do we enable dynmaic timely goodput by default");
1153 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1154 	    SYSCTL_CHILDREN(rack_timely),
1155 	    OID_AUTO, "no_rec_red", CTLFLAG_RW,
1156 	    &rack_gp_no_rec_chg, 1,
1157 	    "Rack timely do we prohibit the recovery multiplier from being lowered");
1158 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1159 	    SYSCTL_CHILDREN(rack_timely),
1160 	    OID_AUTO, "red_clear_cnt", CTLFLAG_RW,
1161 	    &rack_timely_dec_clear, 6,
1162 	    "Rack timely what threshold do we count to before another boost during b/w decent");
1163 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1164 	    SYSCTL_CHILDREN(rack_timely),
1165 	    OID_AUTO, "max_push_rise", CTLFLAG_RW,
1166 	    &rack_timely_max_push_rise, 3,
1167 	    "Rack timely how many times do we push up with b/w increase");
1168 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1169 	    SYSCTL_CHILDREN(rack_timely),
1170 	    OID_AUTO, "max_push_drop", CTLFLAG_RW,
1171 	    &rack_timely_max_push_drop, 3,
1172 	    "Rack timely how many times do we push back on b/w decent");
1173 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1174 	    SYSCTL_CHILDREN(rack_timely),
1175 	    OID_AUTO, "min_segs", CTLFLAG_RW,
1176 	    &rack_timely_min_segs, 4,
1177 	    "Rack timely when setting the cwnd what is the min num segments");
1178 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1179 	    SYSCTL_CHILDREN(rack_timely),
1180 	    OID_AUTO, "noback_max", CTLFLAG_RW,
1181 	    &rack_use_max_for_nobackoff, 0,
1182 	    "Rack timely when deciding if to backoff on a loss, do we use under max rtt else min");
1183 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1184 	    SYSCTL_CHILDREN(rack_timely),
1185 	    OID_AUTO, "interim_timely_only", CTLFLAG_RW,
1186 	    &rack_timely_int_timely_only, 0,
1187 	    "Rack timely when doing interim timely's do we only do timely (no b/w consideration)");
1188 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1189 	    SYSCTL_CHILDREN(rack_timely),
1190 	    OID_AUTO, "nonstop", CTLFLAG_RW,
1191 	    &rack_timely_no_stopping, 0,
1192 	    "Rack timely don't stop increase");
1193 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1194 	    SYSCTL_CHILDREN(rack_timely),
1195 	    OID_AUTO, "dec_raise_thresh", CTLFLAG_RW,
1196 	    &rack_down_raise_thresh, 100,
1197 	    "If the CA or SS is below this threshold raise on the first 3 b/w lowers (0=always)");
1198 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1199 	    SYSCTL_CHILDREN(rack_timely),
1200 	    OID_AUTO, "bottom_drag_segs", CTLFLAG_RW,
1201 	    &rack_req_segs, 1,
1202 	    "Bottom dragging if not these many segments outstanding and room");
1203 
1204 	/* TLP and Rack related parameters */
1205 	rack_tlp = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1206 	    SYSCTL_CHILDREN(rack_sysctl_root),
1207 	    OID_AUTO,
1208 	    "tlp",
1209 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1210 	    "TLP and Rack related Controls");
1211 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1212 	    SYSCTL_CHILDREN(rack_tlp),
1213 	    OID_AUTO, "use_rrr", CTLFLAG_RW,
1214 	    &use_rack_rr, 1,
1215 	    "Do we use Rack Rapid Recovery");
1216 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1217 	    SYSCTL_CHILDREN(rack_tlp),
1218 	    OID_AUTO, "post_rec_labc", CTLFLAG_RW,
1219 	    &rack_max_abc_post_recovery, 2,
1220 	    "Since we do early recovery, do we override the l_abc to a value, if so what?");
1221 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1222 	    SYSCTL_CHILDREN(rack_tlp),
1223 	    OID_AUTO, "nonrxt_use_cr", CTLFLAG_RW,
1224 	    &rack_non_rxt_use_cr, 0,
1225 	    "Do we use ss/ca rate if in recovery we are transmitting a new data chunk");
1226 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1227 	    SYSCTL_CHILDREN(rack_tlp),
1228 	    OID_AUTO, "tlpmethod", CTLFLAG_RW,
1229 	    &rack_tlp_threshold_use, TLP_USE_TWO_ONE,
1230 	    "What method do we do for TLP time calc 0=no-de-ack-comp, 1=ID, 2=2.1, 3=2.2");
1231 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1232 	    SYSCTL_CHILDREN(rack_tlp),
1233 	    OID_AUTO, "limit", CTLFLAG_RW,
1234 	    &rack_tlp_limit, 2,
1235 	    "How many TLP's can be sent without sending new data");
1236 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1237 	    SYSCTL_CHILDREN(rack_tlp),
1238 	    OID_AUTO, "use_greater", CTLFLAG_RW,
1239 	    &rack_tlp_use_greater, 1,
1240 	    "Should we use the rack_rtt time if its greater than srtt");
1241 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1242 	    SYSCTL_CHILDREN(rack_tlp),
1243 	    OID_AUTO, "tlpminto", CTLFLAG_RW,
1244 	    &rack_tlp_min, 10000,
1245 	    "TLP minimum timeout per the specification (in microseconds)");
1246 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1247 	    SYSCTL_CHILDREN(rack_tlp),
1248 	    OID_AUTO, "send_oldest", CTLFLAG_RW,
1249 	    &rack_always_send_oldest, 0,
1250 	    "Should we always send the oldest TLP and RACK-TLP");
1251 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1252 	    SYSCTL_CHILDREN(rack_tlp),
1253 	    OID_AUTO, "rack_tlimit", CTLFLAG_RW,
1254 	    &rack_limited_retran, 0,
1255 	    "How many times can a rack timeout drive out sends");
1256 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1257 	    SYSCTL_CHILDREN(rack_tlp),
1258 	    OID_AUTO, "tlp_cwnd_flag", CTLFLAG_RW,
1259 	    &rack_lower_cwnd_at_tlp, 0,
1260 	    "When a TLP completes a retran should we enter recovery");
1261 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1262 	    SYSCTL_CHILDREN(rack_tlp),
1263 	    OID_AUTO, "reorder_thresh", CTLFLAG_RW,
1264 	    &rack_reorder_thresh, 2,
1265 	    "What factor for rack will be added when seeing reordering (shift right)");
1266 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1267 	    SYSCTL_CHILDREN(rack_tlp),
1268 	    OID_AUTO, "rtt_tlp_thresh", CTLFLAG_RW,
1269 	    &rack_tlp_thresh, 1,
1270 	    "What divisor for TLP rtt/retran will be added (1=rtt, 2=1/2 rtt etc)");
1271 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1272 	    SYSCTL_CHILDREN(rack_tlp),
1273 	    OID_AUTO, "reorder_fade", CTLFLAG_RW,
1274 	    &rack_reorder_fade, 60000000,
1275 	    "Does reorder detection fade, if so how many microseconds (0 means never)");
1276 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1277 	    SYSCTL_CHILDREN(rack_tlp),
1278 	    OID_AUTO, "pktdelay", CTLFLAG_RW,
1279 	    &rack_pkt_delay, 1000,
1280 	    "Extra RACK time (in microseconds) besides reordering thresh");
1281 
1282 	/* Timer related controls */
1283 	rack_timers = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1284 	    SYSCTL_CHILDREN(rack_sysctl_root),
1285 	    OID_AUTO,
1286 	    "timers",
1287 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1288 	    "Timer related controls");
1289 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1290 	    SYSCTL_CHILDREN(rack_timers),
1291 	    OID_AUTO, "persmin", CTLFLAG_RW,
1292 	    &rack_persist_min, 250000,
1293 	    "What is the minimum time in microseconds between persists");
1294 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1295 	    SYSCTL_CHILDREN(rack_timers),
1296 	    OID_AUTO, "persmax", CTLFLAG_RW,
1297 	    &rack_persist_max, 2000000,
1298 	    "What is the largest delay in microseconds between persists");
1299 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1300 	    SYSCTL_CHILDREN(rack_timers),
1301 	    OID_AUTO, "delayed_ack", CTLFLAG_RW,
1302 	    &rack_delayed_ack_time, 40000,
1303 	    "Delayed ack time (40ms in microseconds)");
1304 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1305 	    SYSCTL_CHILDREN(rack_timers),
1306 	    OID_AUTO, "minrto", CTLFLAG_RW,
1307 	    &rack_rto_min, 30000,
1308 	    "Minimum RTO in microseconds -- set with caution below 1000 due to TLP");
1309 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1310 	    SYSCTL_CHILDREN(rack_timers),
1311 	    OID_AUTO, "maxrto", CTLFLAG_RW,
1312 	    &rack_rto_max, 4000000,
1313 	    "Maximum RTO in microseconds -- should be at least as large as min_rto");
1314 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1315 	    SYSCTL_CHILDREN(rack_timers),
1316 	    OID_AUTO, "minto", CTLFLAG_RW,
1317 	    &rack_min_to, 1000,
1318 	    "Minimum rack timeout in microseconds");
1319 	/* Measure controls */
1320 	rack_measure = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1321 	    SYSCTL_CHILDREN(rack_sysctl_root),
1322 	    OID_AUTO,
1323 	    "measure",
1324 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1325 	    "Measure related controls");
1326 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1327 	    SYSCTL_CHILDREN(rack_measure),
1328 	    OID_AUTO, "wma_divisor", CTLFLAG_RW,
1329 	    &rack_wma_divisor, 8,
1330 	    "When doing b/w calculation what is the  divisor for the WMA");
1331 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1332 	    SYSCTL_CHILDREN(rack_measure),
1333 	    OID_AUTO, "end_cwnd", CTLFLAG_RW,
1334 	    &rack_cwnd_block_ends_measure, 0,
1335 	    "Does a cwnd just-return end the measurement window (app limited)");
1336 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1337 	    SYSCTL_CHILDREN(rack_measure),
1338 	    OID_AUTO, "end_rwnd", CTLFLAG_RW,
1339 	    &rack_rwnd_block_ends_measure, 0,
1340 	    "Does an rwnd just-return end the measurement window (app limited -- not persists)");
1341 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1342 	    SYSCTL_CHILDREN(rack_measure),
1343 	    OID_AUTO, "min_target", CTLFLAG_RW,
1344 	    &rack_def_data_window, 20,
1345 	    "What is the minimum target window (in mss) for a GP measurements");
1346 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1347 	    SYSCTL_CHILDREN(rack_measure),
1348 	    OID_AUTO, "goal_bdp", CTLFLAG_RW,
1349 	    &rack_goal_bdp, 2,
1350 	    "What is the goal BDP to measure");
1351 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1352 	    SYSCTL_CHILDREN(rack_measure),
1353 	    OID_AUTO, "min_srtts", CTLFLAG_RW,
1354 	    &rack_min_srtts, 1,
1355 	    "What is the goal BDP to measure");
1356 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1357 	    SYSCTL_CHILDREN(rack_measure),
1358 	    OID_AUTO, "min_measure_tim", CTLFLAG_RW,
1359 	    &rack_min_measure_usec, 0,
1360 	    "What is the Minimum time time for a measurement if 0, this is off");
1361 	/* Features */
1362 	rack_features = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1363 	    SYSCTL_CHILDREN(rack_sysctl_root),
1364 	    OID_AUTO,
1365 	    "features",
1366 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1367 	    "Feature controls");
1368 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1369 	    SYSCTL_CHILDREN(rack_features),
1370 	    OID_AUTO, "cmpack", CTLFLAG_RW,
1371 	    &rack_use_cmp_acks, 1,
1372 	    "Should RACK have LRO send compressed acks");
1373 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1374 	    SYSCTL_CHILDREN(rack_features),
1375 	    OID_AUTO, "fsb", CTLFLAG_RW,
1376 	    &rack_use_fsb, 1,
1377 	    "Should RACK use the fast send block?");
1378 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1379 	    SYSCTL_CHILDREN(rack_features),
1380 	    OID_AUTO, "rfo", CTLFLAG_RW,
1381 	    &rack_use_rfo, 1,
1382 	    "Should RACK use rack_fast_output()?");
1383 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1384 	    SYSCTL_CHILDREN(rack_features),
1385 	    OID_AUTO, "rsmrfo", CTLFLAG_RW,
1386 	    &rack_use_rsm_rfo, 1,
1387 	    "Should RACK use rack_fast_rsm_output()?");
1388 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1389 	    SYSCTL_CHILDREN(rack_features),
1390 	    OID_AUTO, "non_paced_lro_queue", CTLFLAG_RW,
1391 	    &rack_enable_mqueue_for_nonpaced, 0,
1392 	    "Should RACK use mbuf queuing for non-paced connections");
1393 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1394 	    SYSCTL_CHILDREN(rack_features),
1395 	    OID_AUTO, "hystartplusplus", CTLFLAG_RW,
1396 	    &rack_do_hystart, 0,
1397 	    "Should RACK enable HyStart++ on connections?");
1398 	/* Misc rack controls */
1399 	rack_misc = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1400 	    SYSCTL_CHILDREN(rack_sysctl_root),
1401 	    OID_AUTO,
1402 	    "misc",
1403 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1404 	    "Misc related controls");
1405 #ifdef TCP_ACCOUNTING
1406 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1407 	    SYSCTL_CHILDREN(rack_misc),
1408 	    OID_AUTO, "tcp_acct", CTLFLAG_RW,
1409 	    &rack_tcp_accounting, 0,
1410 	    "Should we turn on TCP accounting for all rack sessions?");
1411 #endif
1412 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1413 	    SYSCTL_CHILDREN(rack_misc),
1414 	    OID_AUTO, "apply_rtt_with_low_conf", CTLFLAG_RW,
1415 	    &rack_apply_rtt_with_reduced_conf, 0,
1416 	    "When a persist or keep-alive probe is not answered do we calculate rtt on subsequent answers?");
1417 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1418 	    SYSCTL_CHILDREN(rack_misc),
1419 	    OID_AUTO, "rack_dsack_ctl", CTLFLAG_RW,
1420 	    &rack_dsack_std_based, 3,
1421 	    "How do we process dsack with respect to rack timers, bit field, 3 is standards based?");
1422 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1423 	    SYSCTL_CHILDREN(rack_misc),
1424 	    OID_AUTO, "prr_addback_max", CTLFLAG_RW,
1425 	    &rack_prr_addbackmax, 2,
1426 	    "What is the maximum number of MSS we allow to be added back if prr can't send all its data?");
1427 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1428 	    SYSCTL_CHILDREN(rack_misc),
1429 	    OID_AUTO, "stats_gets_ms", CTLFLAG_RW,
1430 	    &rack_stats_gets_ms_rtt, 1,
1431 	    "What do we feed the stats framework (1 = ms_rtt, 0 = us_rtt, 2 = ms_rtt from hdwr, > 2 usec rtt from hdwr)?");
1432 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1433 	    SYSCTL_CHILDREN(rack_misc),
1434 	    OID_AUTO, "clientlowbuf", CTLFLAG_RW,
1435 	    &rack_client_low_buf, 0,
1436 	    "Client low buffer level (below this we are more aggressive in DGP exiting recovery (0 = off)?");
1437 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1438 	    SYSCTL_CHILDREN(rack_misc),
1439 	    OID_AUTO, "defprofile", CTLFLAG_RW,
1440 	    &rack_def_profile, 0,
1441 	    "Should RACK use a default profile (0=no, num == profile num)?");
1442 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1443 	    SYSCTL_CHILDREN(rack_misc),
1444 	    OID_AUTO, "shared_cwnd", CTLFLAG_RW,
1445 	    &rack_enable_shared_cwnd, 1,
1446 	    "Should RACK try to use the shared cwnd on connections where allowed");
1447 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1448 	    SYSCTL_CHILDREN(rack_misc),
1449 	    OID_AUTO, "limits_on_scwnd", CTLFLAG_RW,
1450 	    &rack_limits_scwnd, 1,
1451 	    "Should RACK place low end time limits on the shared cwnd feature");
1452 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1453 	    SYSCTL_CHILDREN(rack_misc),
1454 	    OID_AUTO, "iMac_dack", CTLFLAG_RW,
1455 	    &rack_use_imac_dack, 0,
1456 	    "Should RACK try to emulate iMac delayed ack");
1457 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1458 	    SYSCTL_CHILDREN(rack_misc),
1459 	    OID_AUTO, "no_prr", CTLFLAG_RW,
1460 	    &rack_disable_prr, 0,
1461 	    "Should RACK not use prr and only pace (must have pacing on)");
1462 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1463 	    SYSCTL_CHILDREN(rack_misc),
1464 	    OID_AUTO, "bb_verbose", CTLFLAG_RW,
1465 	    &rack_verbose_logging, 0,
1466 	    "Should RACK black box logging be verbose");
1467 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1468 	    SYSCTL_CHILDREN(rack_misc),
1469 	    OID_AUTO, "data_after_close", CTLFLAG_RW,
1470 	    &rack_ignore_data_after_close, 1,
1471 	    "Do we hold off sending a RST until all pending data is ack'd");
1472 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1473 	    SYSCTL_CHILDREN(rack_misc),
1474 	    OID_AUTO, "no_sack_needed", CTLFLAG_RW,
1475 	    &rack_sack_not_required, 1,
1476 	    "Do we allow rack to run on connections not supporting SACK");
1477 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1478 	    SYSCTL_CHILDREN(rack_misc),
1479 	    OID_AUTO, "prr_sendalot", CTLFLAG_RW,
1480 	    &rack_send_a_lot_in_prr, 1,
1481 	    "Send a lot in prr");
1482 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1483 	    SYSCTL_CHILDREN(rack_misc),
1484 	    OID_AUTO, "autoscale", CTLFLAG_RW,
1485 	    &rack_autosndbuf_inc, 20,
1486 	    "What percentage should rack scale up its snd buffer by?");
1487 	/* Sack Attacker detection stuff */
1488 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1489 	    SYSCTL_CHILDREN(rack_attack),
1490 	    OID_AUTO, "detect_highsackratio", CTLFLAG_RW,
1491 	    &rack_highest_sack_thresh_seen, 0,
1492 	    "Highest sack to ack ratio seen");
1493 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1494 	    SYSCTL_CHILDREN(rack_attack),
1495 	    OID_AUTO, "detect_highmoveratio", CTLFLAG_RW,
1496 	    &rack_highest_move_thresh_seen, 0,
1497 	    "Highest move to non-move ratio seen");
1498 	rack_ack_total = counter_u64_alloc(M_WAITOK);
1499 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1500 	    SYSCTL_CHILDREN(rack_attack),
1501 	    OID_AUTO, "acktotal", CTLFLAG_RD,
1502 	    &rack_ack_total,
1503 	    "Total number of Ack's");
1504 	rack_express_sack = counter_u64_alloc(M_WAITOK);
1505 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1506 	    SYSCTL_CHILDREN(rack_attack),
1507 	    OID_AUTO, "exp_sacktotal", CTLFLAG_RD,
1508 	    &rack_express_sack,
1509 	    "Total expresss number of Sack's");
1510 	rack_sack_total = counter_u64_alloc(M_WAITOK);
1511 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1512 	    SYSCTL_CHILDREN(rack_attack),
1513 	    OID_AUTO, "sacktotal", CTLFLAG_RD,
1514 	    &rack_sack_total,
1515 	    "Total number of SACKs");
1516 	rack_move_none = counter_u64_alloc(M_WAITOK);
1517 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1518 	    SYSCTL_CHILDREN(rack_attack),
1519 	    OID_AUTO, "move_none", CTLFLAG_RD,
1520 	    &rack_move_none,
1521 	    "Total number of SACK index reuse of positions under threshold");
1522 	rack_move_some = counter_u64_alloc(M_WAITOK);
1523 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1524 	    SYSCTL_CHILDREN(rack_attack),
1525 	    OID_AUTO, "move_some", CTLFLAG_RD,
1526 	    &rack_move_some,
1527 	    "Total number of SACK index reuse of positions over threshold");
1528 	rack_sack_attacks_detected = counter_u64_alloc(M_WAITOK);
1529 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1530 	    SYSCTL_CHILDREN(rack_attack),
1531 	    OID_AUTO, "attacks", CTLFLAG_RD,
1532 	    &rack_sack_attacks_detected,
1533 	    "Total number of SACK attackers that had sack disabled");
1534 	rack_sack_attacks_reversed = counter_u64_alloc(M_WAITOK);
1535 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1536 	    SYSCTL_CHILDREN(rack_attack),
1537 	    OID_AUTO, "reversed", CTLFLAG_RD,
1538 	    &rack_sack_attacks_reversed,
1539 	    "Total number of SACK attackers that were later determined false positive");
1540 	rack_sack_used_next_merge = counter_u64_alloc(M_WAITOK);
1541 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1542 	    SYSCTL_CHILDREN(rack_attack),
1543 	    OID_AUTO, "nextmerge", CTLFLAG_RD,
1544 	    &rack_sack_used_next_merge,
1545 	    "Total number of times we used the next merge");
1546 	rack_sack_used_prev_merge = counter_u64_alloc(M_WAITOK);
1547 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1548 	    SYSCTL_CHILDREN(rack_attack),
1549 	    OID_AUTO, "prevmerge", CTLFLAG_RD,
1550 	    &rack_sack_used_prev_merge,
1551 	    "Total number of times we used the prev merge");
1552 	/* Counters */
1553 	rack_fto_send = counter_u64_alloc(M_WAITOK);
1554 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1555 	    SYSCTL_CHILDREN(rack_counters),
1556 	    OID_AUTO, "fto_send", CTLFLAG_RD,
1557 	    &rack_fto_send, "Total number of rack_fast_output sends");
1558 	rack_fto_rsm_send = counter_u64_alloc(M_WAITOK);
1559 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1560 	    SYSCTL_CHILDREN(rack_counters),
1561 	    OID_AUTO, "fto_rsm_send", CTLFLAG_RD,
1562 	    &rack_fto_rsm_send, "Total number of rack_fast_rsm_output sends");
1563 	rack_nfto_resend = counter_u64_alloc(M_WAITOK);
1564 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1565 	    SYSCTL_CHILDREN(rack_counters),
1566 	    OID_AUTO, "nfto_resend", CTLFLAG_RD,
1567 	    &rack_nfto_resend, "Total number of rack_output retransmissions");
1568 	rack_non_fto_send = counter_u64_alloc(M_WAITOK);
1569 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1570 	    SYSCTL_CHILDREN(rack_counters),
1571 	    OID_AUTO, "nfto_send", CTLFLAG_RD,
1572 	    &rack_non_fto_send, "Total number of rack_output first sends");
1573 	rack_extended_rfo = counter_u64_alloc(M_WAITOK);
1574 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1575 	    SYSCTL_CHILDREN(rack_counters),
1576 	    OID_AUTO, "rfo_extended", CTLFLAG_RD,
1577 	    &rack_extended_rfo, "Total number of times we extended rfo");
1578 
1579 	rack_hw_pace_init_fail = counter_u64_alloc(M_WAITOK);
1580 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1581 	    SYSCTL_CHILDREN(rack_counters),
1582 	    OID_AUTO, "hwpace_init_fail", CTLFLAG_RD,
1583 	    &rack_hw_pace_init_fail, "Total number of times we failed to initialize hw pacing");
1584 	rack_hw_pace_lost = counter_u64_alloc(M_WAITOK);
1585 
1586 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1587 	    SYSCTL_CHILDREN(rack_counters),
1588 	    OID_AUTO, "hwpace_lost", CTLFLAG_RD,
1589 	    &rack_hw_pace_lost, "Total number of times we failed to initialize hw pacing");
1590 	rack_tlp_tot = counter_u64_alloc(M_WAITOK);
1591 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1592 	    SYSCTL_CHILDREN(rack_counters),
1593 	    OID_AUTO, "tlp_to_total", CTLFLAG_RD,
1594 	    &rack_tlp_tot,
1595 	    "Total number of tail loss probe expirations");
1596 	rack_tlp_newdata = counter_u64_alloc(M_WAITOK);
1597 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1598 	    SYSCTL_CHILDREN(rack_counters),
1599 	    OID_AUTO, "tlp_new", CTLFLAG_RD,
1600 	    &rack_tlp_newdata,
1601 	    "Total number of tail loss probe sending new data");
1602 	rack_tlp_retran = counter_u64_alloc(M_WAITOK);
1603 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1604 	    SYSCTL_CHILDREN(rack_counters),
1605 	    OID_AUTO, "tlp_retran", CTLFLAG_RD,
1606 	    &rack_tlp_retran,
1607 	    "Total number of tail loss probe sending retransmitted data");
1608 	rack_tlp_retran_bytes = counter_u64_alloc(M_WAITOK);
1609 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1610 	    SYSCTL_CHILDREN(rack_counters),
1611 	    OID_AUTO, "tlp_retran_bytes", CTLFLAG_RD,
1612 	    &rack_tlp_retran_bytes,
1613 	    "Total bytes of tail loss probe sending retransmitted data");
1614 	rack_to_tot = counter_u64_alloc(M_WAITOK);
1615 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1616 	    SYSCTL_CHILDREN(rack_counters),
1617 	    OID_AUTO, "rack_to_tot", CTLFLAG_RD,
1618 	    &rack_to_tot,
1619 	    "Total number of times the rack to expired");
1620 	rack_saw_enobuf = counter_u64_alloc(M_WAITOK);
1621 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1622 	    SYSCTL_CHILDREN(rack_counters),
1623 	    OID_AUTO, "saw_enobufs", CTLFLAG_RD,
1624 	    &rack_saw_enobuf,
1625 	    "Total number of times a sends returned enobuf for non-hdwr paced connections");
1626 	rack_saw_enobuf_hw = counter_u64_alloc(M_WAITOK);
1627 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1628 	    SYSCTL_CHILDREN(rack_counters),
1629 	    OID_AUTO, "saw_enobufs_hw", CTLFLAG_RD,
1630 	    &rack_saw_enobuf_hw,
1631 	    "Total number of times a send returned enobuf for hdwr paced connections");
1632 	rack_saw_enetunreach = counter_u64_alloc(M_WAITOK);
1633 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1634 	    SYSCTL_CHILDREN(rack_counters),
1635 	    OID_AUTO, "saw_enetunreach", CTLFLAG_RD,
1636 	    &rack_saw_enetunreach,
1637 	    "Total number of times a send received a enetunreachable");
1638 	rack_hot_alloc = counter_u64_alloc(M_WAITOK);
1639 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1640 	    SYSCTL_CHILDREN(rack_counters),
1641 	    OID_AUTO, "alloc_hot", CTLFLAG_RD,
1642 	    &rack_hot_alloc,
1643 	    "Total allocations from the top of our list");
1644 	rack_to_alloc = counter_u64_alloc(M_WAITOK);
1645 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1646 	    SYSCTL_CHILDREN(rack_counters),
1647 	    OID_AUTO, "allocs", CTLFLAG_RD,
1648 	    &rack_to_alloc,
1649 	    "Total allocations of tracking structures");
1650 	rack_to_alloc_hard = counter_u64_alloc(M_WAITOK);
1651 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1652 	    SYSCTL_CHILDREN(rack_counters),
1653 	    OID_AUTO, "allochard", CTLFLAG_RD,
1654 	    &rack_to_alloc_hard,
1655 	    "Total allocations done with sleeping the hard way");
1656 	rack_to_alloc_emerg = counter_u64_alloc(M_WAITOK);
1657 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1658 	    SYSCTL_CHILDREN(rack_counters),
1659 	    OID_AUTO, "allocemerg", CTLFLAG_RD,
1660 	    &rack_to_alloc_emerg,
1661 	    "Total allocations done from emergency cache");
1662 	rack_to_alloc_limited = counter_u64_alloc(M_WAITOK);
1663 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1664 	    SYSCTL_CHILDREN(rack_counters),
1665 	    OID_AUTO, "alloc_limited", CTLFLAG_RD,
1666 	    &rack_to_alloc_limited,
1667 	    "Total allocations dropped due to limit");
1668 	rack_alloc_limited_conns = counter_u64_alloc(M_WAITOK);
1669 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1670 	    SYSCTL_CHILDREN(rack_counters),
1671 	    OID_AUTO, "alloc_limited_conns", CTLFLAG_RD,
1672 	    &rack_alloc_limited_conns,
1673 	    "Connections with allocations dropped due to limit");
1674 	rack_split_limited = counter_u64_alloc(M_WAITOK);
1675 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1676 	    SYSCTL_CHILDREN(rack_counters),
1677 	    OID_AUTO, "split_limited", CTLFLAG_RD,
1678 	    &rack_split_limited,
1679 	    "Split allocations dropped due to limit");
1680 	rack_persists_sends = counter_u64_alloc(M_WAITOK);
1681 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1682 	    SYSCTL_CHILDREN(rack_counters),
1683 	    OID_AUTO, "persist_sends", CTLFLAG_RD,
1684 	    &rack_persists_sends,
1685 	    "Number of times we sent a persist probe");
1686 	rack_persists_acks = counter_u64_alloc(M_WAITOK);
1687 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1688 	    SYSCTL_CHILDREN(rack_counters),
1689 	    OID_AUTO, "persist_acks", CTLFLAG_RD,
1690 	    &rack_persists_acks,
1691 	    "Number of times a persist probe was acked");
1692 	rack_persists_loss = counter_u64_alloc(M_WAITOK);
1693 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1694 	    SYSCTL_CHILDREN(rack_counters),
1695 	    OID_AUTO, "persist_loss", CTLFLAG_RD,
1696 	    &rack_persists_loss,
1697 	    "Number of times we detected a lost persist probe (no ack)");
1698 	rack_persists_lost_ends = counter_u64_alloc(M_WAITOK);
1699 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1700 	    SYSCTL_CHILDREN(rack_counters),
1701 	    OID_AUTO, "persist_loss_ends", CTLFLAG_RD,
1702 	    &rack_persists_lost_ends,
1703 	    "Number of lost persist probe (no ack) that the run ended with a PERSIST abort");
1704 #ifdef INVARIANTS
1705 	rack_adjust_map_bw = counter_u64_alloc(M_WAITOK);
1706 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1707 	    SYSCTL_CHILDREN(rack_counters),
1708 	    OID_AUTO, "map_adjust_req", CTLFLAG_RD,
1709 	    &rack_adjust_map_bw,
1710 	    "Number of times we hit the case where the sb went up and down on a sendmap entry");
1711 #endif
1712 	rack_multi_single_eq = counter_u64_alloc(M_WAITOK);
1713 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1714 	    SYSCTL_CHILDREN(rack_counters),
1715 	    OID_AUTO, "cmp_ack_equiv", CTLFLAG_RD,
1716 	    &rack_multi_single_eq,
1717 	    "Number of compressed acks total represented");
1718 	rack_proc_non_comp_ack = counter_u64_alloc(M_WAITOK);
1719 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1720 	    SYSCTL_CHILDREN(rack_counters),
1721 	    OID_AUTO, "cmp_ack_not", CTLFLAG_RD,
1722 	    &rack_proc_non_comp_ack,
1723 	    "Number of non compresseds acks that we processed");
1724 
1725 
1726 	rack_sack_proc_all = counter_u64_alloc(M_WAITOK);
1727 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1728 	    SYSCTL_CHILDREN(rack_counters),
1729 	    OID_AUTO, "sack_long", CTLFLAG_RD,
1730 	    &rack_sack_proc_all,
1731 	    "Total times we had to walk whole list for sack processing");
1732 	rack_sack_proc_restart = counter_u64_alloc(M_WAITOK);
1733 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1734 	    SYSCTL_CHILDREN(rack_counters),
1735 	    OID_AUTO, "sack_restart", CTLFLAG_RD,
1736 	    &rack_sack_proc_restart,
1737 	    "Total times we had to walk whole list due to a restart");
1738 	rack_sack_proc_short = counter_u64_alloc(M_WAITOK);
1739 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1740 	    SYSCTL_CHILDREN(rack_counters),
1741 	    OID_AUTO, "sack_short", CTLFLAG_RD,
1742 	    &rack_sack_proc_short,
1743 	    "Total times we took shortcut for sack processing");
1744 	rack_sack_skipped_acked = counter_u64_alloc(M_WAITOK);
1745 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1746 	    SYSCTL_CHILDREN(rack_attack),
1747 	    OID_AUTO, "skipacked", CTLFLAG_RD,
1748 	    &rack_sack_skipped_acked,
1749 	    "Total number of times we skipped previously sacked");
1750 	rack_sack_splits = counter_u64_alloc(M_WAITOK);
1751 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1752 	    SYSCTL_CHILDREN(rack_attack),
1753 	    OID_AUTO, "ofsplit", CTLFLAG_RD,
1754 	    &rack_sack_splits,
1755 	    "Total number of times we did the old fashion tree split");
1756 	rack_input_idle_reduces = counter_u64_alloc(M_WAITOK);
1757 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1758 	    SYSCTL_CHILDREN(rack_counters),
1759 	    OID_AUTO, "idle_reduce_oninput", CTLFLAG_RD,
1760 	    &rack_input_idle_reduces,
1761 	    "Total number of idle reductions on input");
1762 	rack_collapsed_win_seen = counter_u64_alloc(M_WAITOK);
1763 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1764 	    SYSCTL_CHILDREN(rack_counters),
1765 	    OID_AUTO, "collapsed_win_seen", CTLFLAG_RD,
1766 	    &rack_collapsed_win_seen,
1767 	    "Total number of collapsed window events seen (where our window shrinks)");
1768 
1769 	rack_collapsed_win = counter_u64_alloc(M_WAITOK);
1770 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1771 	    SYSCTL_CHILDREN(rack_counters),
1772 	    OID_AUTO, "collapsed_win", CTLFLAG_RD,
1773 	    &rack_collapsed_win,
1774 	    "Total number of collapsed window events where we mark packets");
1775 	rack_collapsed_win_rxt = counter_u64_alloc(M_WAITOK);
1776 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1777 	    SYSCTL_CHILDREN(rack_counters),
1778 	    OID_AUTO, "collapsed_win_rxt", CTLFLAG_RD,
1779 	    &rack_collapsed_win_rxt,
1780 	    "Total number of packets that were retransmitted");
1781 	rack_collapsed_win_rxt_bytes = counter_u64_alloc(M_WAITOK);
1782 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1783 	    SYSCTL_CHILDREN(rack_counters),
1784 	    OID_AUTO, "collapsed_win_bytes", CTLFLAG_RD,
1785 	    &rack_collapsed_win_rxt_bytes,
1786 	    "Total number of bytes that were retransmitted");
1787 	rack_try_scwnd = counter_u64_alloc(M_WAITOK);
1788 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1789 	    SYSCTL_CHILDREN(rack_counters),
1790 	    OID_AUTO, "tried_scwnd", CTLFLAG_RD,
1791 	    &rack_try_scwnd,
1792 	    "Total number of scwnd attempts");
1793 	COUNTER_ARRAY_ALLOC(rack_out_size, TCP_MSS_ACCT_SIZE, M_WAITOK);
1794 	SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
1795 	    OID_AUTO, "outsize", CTLFLAG_RD,
1796 	    rack_out_size, TCP_MSS_ACCT_SIZE, "MSS send sizes");
1797 	COUNTER_ARRAY_ALLOC(rack_opts_arry, RACK_OPTS_SIZE, M_WAITOK);
1798 	SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
1799 	    OID_AUTO, "opts", CTLFLAG_RD,
1800 	    rack_opts_arry, RACK_OPTS_SIZE, "RACK Option Stats");
1801 	SYSCTL_ADD_PROC(&rack_sysctl_ctx,
1802 	    SYSCTL_CHILDREN(rack_sysctl_root),
1803 	    OID_AUTO, "clear", CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE,
1804 	    &rack_clear_counter, 0, sysctl_rack_clear, "IU", "Clear counters");
1805 }
1806 
1807 static __inline int
1808 rb_map_cmp(struct rack_sendmap *b, struct rack_sendmap *a)
1809 {
1810 	if (SEQ_GEQ(b->r_start, a->r_start) &&
1811 	    SEQ_LT(b->r_start, a->r_end)) {
1812 		/*
1813 		 * The entry b is within the
1814 		 * block a. i.e.:
1815 		 * a --   |-------------|
1816 		 * b --   |----|
1817 		 * <or>
1818 		 * b --       |------|
1819 		 * <or>
1820 		 * b --       |-----------|
1821 		 */
1822 		return (0);
1823 	} else if (SEQ_GEQ(b->r_start, a->r_end)) {
1824 		/*
1825 		 * b falls as either the next
1826 		 * sequence block after a so a
1827 		 * is said to be smaller than b.
1828 		 * i.e:
1829 		 * a --   |------|
1830 		 * b --          |--------|
1831 		 * or
1832 		 * b --              |-----|
1833 		 */
1834 		return (1);
1835 	}
1836 	/*
1837 	 * Whats left is where a is
1838 	 * larger than b. i.e:
1839 	 * a --         |-------|
1840 	 * b --  |---|
1841 	 * or even possibly
1842 	 * b --   |--------------|
1843 	 */
1844 	return (-1);
1845 }
1846 
1847 RB_PROTOTYPE(rack_rb_tree_head, rack_sendmap, r_next, rb_map_cmp);
1848 RB_GENERATE(rack_rb_tree_head, rack_sendmap, r_next, rb_map_cmp);
1849 
1850 static uint32_t
1851 rc_init_window(struct tcp_rack *rack)
1852 {
1853 	uint32_t win;
1854 
1855 	if (rack->rc_init_win == 0) {
1856 		/*
1857 		 * Nothing set by the user, use the system stack
1858 		 * default.
1859 		 */
1860 		return (tcp_compute_initwnd(tcp_maxseg(rack->rc_tp)));
1861 	}
1862 	win = ctf_fixed_maxseg(rack->rc_tp) * rack->rc_init_win;
1863 	return (win);
1864 }
1865 
1866 static uint64_t
1867 rack_get_fixed_pacing_bw(struct tcp_rack *rack)
1868 {
1869 	if (IN_FASTRECOVERY(rack->rc_tp->t_flags))
1870 		return (rack->r_ctl.rc_fixed_pacing_rate_rec);
1871 	else if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
1872 		return (rack->r_ctl.rc_fixed_pacing_rate_ss);
1873 	else
1874 		return (rack->r_ctl.rc_fixed_pacing_rate_ca);
1875 }
1876 
1877 static uint64_t
1878 rack_get_bw(struct tcp_rack *rack)
1879 {
1880 	if (rack->use_fixed_rate) {
1881 		/* Return the fixed pacing rate */
1882 		return (rack_get_fixed_pacing_bw(rack));
1883 	}
1884 	if (rack->r_ctl.gp_bw == 0) {
1885 		/*
1886 		 * We have yet no b/w measurement,
1887 		 * if we have a user set initial bw
1888 		 * return it. If we don't have that and
1889 		 * we have an srtt, use the tcp IW (10) to
1890 		 * calculate a fictional b/w over the SRTT
1891 		 * which is more or less a guess. Note
1892 		 * we don't use our IW from rack on purpose
1893 		 * so if we have like IW=30, we are not
1894 		 * calculating a "huge" b/w.
1895 		 */
1896 		uint64_t bw, srtt;
1897 		if (rack->r_ctl.init_rate)
1898 			return (rack->r_ctl.init_rate);
1899 
1900 		/* Has the user set a max peak rate? */
1901 #ifdef NETFLIX_PEAKRATE
1902 		if (rack->rc_tp->t_maxpeakrate)
1903 			return (rack->rc_tp->t_maxpeakrate);
1904 #endif
1905 		/* Ok lets come up with the IW guess, if we have a srtt */
1906 		if (rack->rc_tp->t_srtt == 0) {
1907 			/*
1908 			 * Go with old pacing method
1909 			 * i.e. burst mitigation only.
1910 			 */
1911 			return (0);
1912 		}
1913 		/* Ok lets get the initial TCP win (not racks) */
1914 		bw = tcp_compute_initwnd(tcp_maxseg(rack->rc_tp));
1915 		srtt = (uint64_t)rack->rc_tp->t_srtt;
1916 		bw *= (uint64_t)USECS_IN_SECOND;
1917 		bw /= srtt;
1918 		if (rack->r_ctl.bw_rate_cap && (bw > rack->r_ctl.bw_rate_cap))
1919 			bw = rack->r_ctl.bw_rate_cap;
1920 		return (bw);
1921 	} else {
1922 		uint64_t bw;
1923 
1924 		if (rack->r_ctl.num_measurements >= RACK_REQ_AVG) {
1925 			/* Averaging is done, we can return the value */
1926 			bw = rack->r_ctl.gp_bw;
1927 		} else {
1928 			/* Still doing initial average must calculate */
1929 			bw = rack->r_ctl.gp_bw / rack->r_ctl.num_measurements;
1930 		}
1931 #ifdef NETFLIX_PEAKRATE
1932 		if ((rack->rc_tp->t_maxpeakrate) &&
1933 		    (bw > rack->rc_tp->t_maxpeakrate)) {
1934 			/* The user has set a peak rate to pace at
1935 			 * don't allow us to pace faster than that.
1936 			 */
1937 			return (rack->rc_tp->t_maxpeakrate);
1938 		}
1939 #endif
1940 		if (rack->r_ctl.bw_rate_cap && (bw > rack->r_ctl.bw_rate_cap))
1941 			bw = rack->r_ctl.bw_rate_cap;
1942 		return (bw);
1943 	}
1944 }
1945 
1946 static uint16_t
1947 rack_get_output_gain(struct tcp_rack *rack, struct rack_sendmap *rsm)
1948 {
1949 	if (rack->use_fixed_rate) {
1950 		return (100);
1951 	} else if (rack->in_probe_rtt && (rsm == NULL))
1952 		return (rack->r_ctl.rack_per_of_gp_probertt);
1953 	else if ((IN_FASTRECOVERY(rack->rc_tp->t_flags) &&
1954 		  rack->r_ctl.rack_per_of_gp_rec)) {
1955 		if (rsm) {
1956 			/* a retransmission always use the recovery rate */
1957 			return (rack->r_ctl.rack_per_of_gp_rec);
1958 		} else if (rack->rack_rec_nonrxt_use_cr) {
1959 			/* Directed to use the configured rate */
1960 			goto configured_rate;
1961 		} else if (rack->rack_no_prr &&
1962 			   (rack->r_ctl.rack_per_of_gp_rec > 100)) {
1963 			/* No PRR, lets just use the b/w estimate only */
1964 			return (100);
1965 		} else {
1966 			/*
1967 			 * Here we may have a non-retransmit but we
1968 			 * have no overrides, so just use the recovery
1969 			 * rate (prr is in effect).
1970 			 */
1971 			return (rack->r_ctl.rack_per_of_gp_rec);
1972 		}
1973 	}
1974 configured_rate:
1975 	/* For the configured rate we look at our cwnd vs the ssthresh */
1976 	if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
1977 		return (rack->r_ctl.rack_per_of_gp_ss);
1978 	else
1979 		return (rack->r_ctl.rack_per_of_gp_ca);
1980 }
1981 
1982 static void
1983 rack_log_dsack_event(struct tcp_rack *rack, uint8_t mod, uint32_t flex4, uint32_t flex5, uint32_t flex6)
1984 {
1985 	/*
1986 	 * Types of logs (mod value)
1987 	 * 1 = dsack_persists reduced by 1 via T-O or fast recovery exit.
1988 	 * 2 = a dsack round begins, persist is reset to 16.
1989 	 * 3 = a dsack round ends
1990 	 * 4 = Dsack option increases rack rtt flex5 is the srtt input, flex6 is thresh
1991 	 * 5 = Socket option set changing the control flags rc_rack_tmr_std_based, rc_rack_use_dsack
1992 	 * 6 = Final rack rtt, flex4 is srtt and flex6 is final limited thresh.
1993 	 */
1994 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
1995 		union tcp_log_stackspecific log;
1996 		struct timeval tv;
1997 
1998 		memset(&log, 0, sizeof(log));
1999 		log.u_bbr.flex1 = rack->rc_rack_tmr_std_based;
2000 		log.u_bbr.flex1 <<= 1;
2001 		log.u_bbr.flex1 |= rack->rc_rack_use_dsack;
2002 		log.u_bbr.flex1 <<= 1;
2003 		log.u_bbr.flex1 |= rack->rc_dsack_round_seen;
2004 		log.u_bbr.flex2 = rack->r_ctl.dsack_round_end;
2005 		log.u_bbr.flex3 = rack->r_ctl.num_dsack;
2006 		log.u_bbr.flex4 = flex4;
2007 		log.u_bbr.flex5 = flex5;
2008 		log.u_bbr.flex6 = flex6;
2009 		log.u_bbr.flex7 = rack->r_ctl.dsack_persist;
2010 		log.u_bbr.flex8 = mod;
2011 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2012 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2013 		    &rack->rc_inp->inp_socket->so_rcv,
2014 		    &rack->rc_inp->inp_socket->so_snd,
2015 		    RACK_DSACK_HANDLING, 0,
2016 		    0, &log, false, &tv);
2017 	}
2018 }
2019 
2020 static void
2021 rack_log_hdwr_pacing(struct tcp_rack *rack,
2022 		     uint64_t rate, uint64_t hw_rate, int line,
2023 		     int error, uint16_t mod)
2024 {
2025 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2026 		union tcp_log_stackspecific log;
2027 		struct timeval tv;
2028 		const struct ifnet *ifp;
2029 
2030 		memset(&log, 0, sizeof(log));
2031 		log.u_bbr.flex1 = ((hw_rate >> 32) & 0x00000000ffffffff);
2032 		log.u_bbr.flex2 = (hw_rate & 0x00000000ffffffff);
2033 		if (rack->r_ctl.crte) {
2034 			ifp = rack->r_ctl.crte->ptbl->rs_ifp;
2035 		} else if (rack->rc_inp->inp_route.ro_nh &&
2036 			   rack->rc_inp->inp_route.ro_nh->nh_ifp) {
2037 			ifp = rack->rc_inp->inp_route.ro_nh->nh_ifp;
2038 		} else
2039 			ifp = NULL;
2040 		if (ifp) {
2041 			log.u_bbr.flex3 = (((uint64_t)ifp  >> 32) & 0x00000000ffffffff);
2042 			log.u_bbr.flex4 = ((uint64_t)ifp & 0x00000000ffffffff);
2043 		}
2044 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2045 		log.u_bbr.bw_inuse = rate;
2046 		log.u_bbr.flex5 = line;
2047 		log.u_bbr.flex6 = error;
2048 		log.u_bbr.flex7 = mod;
2049 		log.u_bbr.applimited = rack->r_ctl.rc_pace_max_segs;
2050 		log.u_bbr.flex8 = rack->use_fixed_rate;
2051 		log.u_bbr.flex8 <<= 1;
2052 		log.u_bbr.flex8 |= rack->rack_hdrw_pacing;
2053 		log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
2054 		log.u_bbr.delRate = rack->r_ctl.crte_prev_rate;
2055 		if (rack->r_ctl.crte)
2056 			log.u_bbr.cur_del_rate = rack->r_ctl.crte->rate;
2057 		else
2058 			log.u_bbr.cur_del_rate = 0;
2059 		log.u_bbr.rttProp = rack->r_ctl.last_hw_bw_req;
2060 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2061 		    &rack->rc_inp->inp_socket->so_rcv,
2062 		    &rack->rc_inp->inp_socket->so_snd,
2063 		    BBR_LOG_HDWR_PACE, 0,
2064 		    0, &log, false, &tv);
2065 	}
2066 }
2067 
2068 static uint64_t
2069 rack_get_output_bw(struct tcp_rack *rack, uint64_t bw, struct rack_sendmap *rsm, int *capped)
2070 {
2071 	/*
2072 	 * We allow rack_per_of_gp_xx to dictate our bw rate we want.
2073 	 */
2074 	uint64_t bw_est, high_rate;
2075 	uint64_t gain;
2076 
2077 	gain = (uint64_t)rack_get_output_gain(rack, rsm);
2078 	bw_est = bw * gain;
2079 	bw_est /= (uint64_t)100;
2080 	/* Never fall below the minimum (def 64kbps) */
2081 	if (bw_est < RACK_MIN_BW)
2082 		bw_est = RACK_MIN_BW;
2083 	if (rack->r_rack_hw_rate_caps) {
2084 		/* Rate caps are in place */
2085 		if (rack->r_ctl.crte != NULL) {
2086 			/* We have a hdwr rate already */
2087 			high_rate = tcp_hw_highest_rate(rack->r_ctl.crte);
2088 			if (bw_est >= high_rate) {
2089 				/* We are capping bw at the highest rate table entry */
2090 				rack_log_hdwr_pacing(rack,
2091 						     bw_est, high_rate, __LINE__,
2092 						     0, 3);
2093 				bw_est = high_rate;
2094 				if (capped)
2095 					*capped = 1;
2096 			}
2097 		} else if ((rack->rack_hdrw_pacing == 0) &&
2098 			   (rack->rack_hdw_pace_ena) &&
2099 			   (rack->rack_attempt_hdwr_pace == 0) &&
2100 			   (rack->rc_inp->inp_route.ro_nh != NULL) &&
2101 			   (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
2102 			/*
2103 			 * Special case, we have not yet attempted hardware
2104 			 * pacing, and yet we may, when we do, find out if we are
2105 			 * above the highest rate. We need to know the maxbw for the interface
2106 			 * in question (if it supports ratelimiting). We get back
2107 			 * a 0, if the interface is not found in the RL lists.
2108 			 */
2109 			high_rate = tcp_hw_highest_rate_ifp(rack->rc_inp->inp_route.ro_nh->nh_ifp, rack->rc_inp);
2110 			if (high_rate) {
2111 				/* Yep, we have a rate is it above this rate? */
2112 				if (bw_est > high_rate) {
2113 					bw_est = high_rate;
2114 					if (capped)
2115 						*capped = 1;
2116 				}
2117 			}
2118 		}
2119 	}
2120 	return (bw_est);
2121 }
2122 
2123 static void
2124 rack_log_retran_reason(struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t tsused, uint32_t thresh, int mod)
2125 {
2126 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2127 		union tcp_log_stackspecific log;
2128 		struct timeval tv;
2129 
2130 		if ((mod != 1) && (rack_verbose_logging == 0)) {
2131 			/*
2132 			 * We get 3 values currently for mod
2133 			 * 1 - We are retransmitting and this tells the reason.
2134 			 * 2 - We are clearing a dup-ack count.
2135 			 * 3 - We are incrementing a dup-ack count.
2136 			 *
2137 			 * The clear/increment are only logged
2138 			 * if you have BBverbose on.
2139 			 */
2140 			return;
2141 		}
2142 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2143 		log.u_bbr.flex1 = tsused;
2144 		log.u_bbr.flex2 = thresh;
2145 		log.u_bbr.flex3 = rsm->r_flags;
2146 		log.u_bbr.flex4 = rsm->r_dupack;
2147 		log.u_bbr.flex5 = rsm->r_start;
2148 		log.u_bbr.flex6 = rsm->r_end;
2149 		log.u_bbr.flex8 = mod;
2150 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2151 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2152 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2153 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2154 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2155 		log.u_bbr.pacing_gain = rack->r_must_retran;
2156 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2157 		    &rack->rc_inp->inp_socket->so_rcv,
2158 		    &rack->rc_inp->inp_socket->so_snd,
2159 		    BBR_LOG_SETTINGS_CHG, 0,
2160 		    0, &log, false, &tv);
2161 	}
2162 }
2163 
2164 static void
2165 rack_log_to_start(struct tcp_rack *rack, uint32_t cts, uint32_t to, int32_t slot, uint8_t which)
2166 {
2167 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2168 		union tcp_log_stackspecific log;
2169 		struct timeval tv;
2170 
2171 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2172 		log.u_bbr.flex1 = rack->rc_tp->t_srtt;
2173 		log.u_bbr.flex2 = to;
2174 		log.u_bbr.flex3 = rack->r_ctl.rc_hpts_flags;
2175 		log.u_bbr.flex4 = slot;
2176 		log.u_bbr.flex5 = rack->rc_inp->inp_hptsslot;
2177 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2178 		log.u_bbr.flex7 = rack->rc_in_persist;
2179 		log.u_bbr.flex8 = which;
2180 		if (rack->rack_no_prr)
2181 			log.u_bbr.pkts_out = 0;
2182 		else
2183 			log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
2184 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2185 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2186 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2187 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2188 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2189 		log.u_bbr.pacing_gain = rack->r_must_retran;
2190 		log.u_bbr.cwnd_gain = rack->rc_has_collapsed;
2191 		log.u_bbr.lt_epoch = rack->rc_tp->t_rxtshift;
2192 		log.u_bbr.lost = rack_rto_min;
2193 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2194 		    &rack->rc_inp->inp_socket->so_rcv,
2195 		    &rack->rc_inp->inp_socket->so_snd,
2196 		    BBR_LOG_TIMERSTAR, 0,
2197 		    0, &log, false, &tv);
2198 	}
2199 }
2200 
2201 static void
2202 rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm)
2203 {
2204 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2205 		union tcp_log_stackspecific log;
2206 		struct timeval tv;
2207 
2208 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2209 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2210 		log.u_bbr.flex8 = to_num;
2211 		log.u_bbr.flex1 = rack->r_ctl.rc_rack_min_rtt;
2212 		log.u_bbr.flex2 = rack->rc_rack_rtt;
2213 		if (rsm == NULL)
2214 			log.u_bbr.flex3 = 0;
2215 		else
2216 			log.u_bbr.flex3 = rsm->r_end - rsm->r_start;
2217 		if (rack->rack_no_prr)
2218 			log.u_bbr.flex5 = 0;
2219 		else
2220 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2221 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2222 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2223 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2224 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2225 		log.u_bbr.pacing_gain = rack->r_must_retran;
2226 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2227 		    &rack->rc_inp->inp_socket->so_rcv,
2228 		    &rack->rc_inp->inp_socket->so_snd,
2229 		    BBR_LOG_RTO, 0,
2230 		    0, &log, false, &tv);
2231 	}
2232 }
2233 
2234 static void
2235 rack_log_map_chg(struct tcpcb *tp, struct tcp_rack *rack,
2236 		 struct rack_sendmap *prev,
2237 		 struct rack_sendmap *rsm,
2238 		 struct rack_sendmap *next,
2239 		 int flag, uint32_t th_ack, int line)
2240 {
2241 	if (rack_verbose_logging && (tp->t_logstate != TCP_LOG_STATE_OFF)) {
2242 		union tcp_log_stackspecific log;
2243 		struct timeval tv;
2244 
2245 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2246 		log.u_bbr.flex8 = flag;
2247 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2248 		log.u_bbr.cur_del_rate = (uint64_t)prev;
2249 		log.u_bbr.delRate = (uint64_t)rsm;
2250 		log.u_bbr.rttProp = (uint64_t)next;
2251 		log.u_bbr.flex7 = 0;
2252 		if (prev) {
2253 			log.u_bbr.flex1 = prev->r_start;
2254 			log.u_bbr.flex2 = prev->r_end;
2255 			log.u_bbr.flex7 |= 0x4;
2256 		}
2257 		if (rsm) {
2258 			log.u_bbr.flex3 = rsm->r_start;
2259 			log.u_bbr.flex4 = rsm->r_end;
2260 			log.u_bbr.flex7 |= 0x2;
2261 		}
2262 		if (next) {
2263 			log.u_bbr.flex5 = next->r_start;
2264 			log.u_bbr.flex6 = next->r_end;
2265 			log.u_bbr.flex7 |= 0x1;
2266 		}
2267 		log.u_bbr.applimited = line;
2268 		log.u_bbr.pkts_out = th_ack;
2269 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2270 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2271 		if (rack->rack_no_prr)
2272 			log.u_bbr.lost = 0;
2273 		else
2274 			log.u_bbr.lost = rack->r_ctl.rc_prr_sndcnt;
2275 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2276 		    &rack->rc_inp->inp_socket->so_rcv,
2277 		    &rack->rc_inp->inp_socket->so_snd,
2278 		    TCP_LOG_MAPCHG, 0,
2279 		    0, &log, false, &tv);
2280 	}
2281 }
2282 
2283 static void
2284 rack_log_rtt_upd(struct tcpcb *tp, struct tcp_rack *rack, uint32_t t, uint32_t len,
2285 		 struct rack_sendmap *rsm, int conf)
2286 {
2287 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
2288 		union tcp_log_stackspecific log;
2289 		struct timeval tv;
2290 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2291 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2292 		log.u_bbr.flex1 = t;
2293 		log.u_bbr.flex2 = len;
2294 		log.u_bbr.flex3 = rack->r_ctl.rc_rack_min_rtt;
2295 		log.u_bbr.flex4 = rack->r_ctl.rack_rs.rs_rtt_lowest;
2296 		log.u_bbr.flex5 = rack->r_ctl.rack_rs.rs_rtt_highest;
2297 		log.u_bbr.flex6 = rack->r_ctl.rack_rs.rs_us_rtrcnt;
2298 		log.u_bbr.flex7 = conf;
2299 		log.u_bbr.rttProp = (uint64_t)rack->r_ctl.rack_rs.rs_rtt_tot;
2300 		log.u_bbr.flex8 = rack->r_ctl.rc_rate_sample_method;
2301 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2302 		log.u_bbr.delivered = rack->r_ctl.rack_rs.rs_us_rtrcnt;
2303 		log.u_bbr.pkts_out = rack->r_ctl.rack_rs.rs_flags;
2304 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2305 		if (rsm) {
2306 			log.u_bbr.pkt_epoch = rsm->r_start;
2307 			log.u_bbr.lost = rsm->r_end;
2308 			log.u_bbr.cwnd_gain = rsm->r_rtr_cnt;
2309 			/* We loose any upper of the 24 bits */
2310 			log.u_bbr.pacing_gain = (uint16_t)rsm->r_flags;
2311 		} else {
2312 			/* Its a SYN */
2313 			log.u_bbr.pkt_epoch = rack->rc_tp->iss;
2314 			log.u_bbr.lost = 0;
2315 			log.u_bbr.cwnd_gain = 0;
2316 			log.u_bbr.pacing_gain = 0;
2317 		}
2318 		/* Write out general bits of interest rrs here */
2319 		log.u_bbr.use_lt_bw = rack->rc_highly_buffered;
2320 		log.u_bbr.use_lt_bw <<= 1;
2321 		log.u_bbr.use_lt_bw |= rack->forced_ack;
2322 		log.u_bbr.use_lt_bw <<= 1;
2323 		log.u_bbr.use_lt_bw |= rack->rc_gp_dyn_mul;
2324 		log.u_bbr.use_lt_bw <<= 1;
2325 		log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
2326 		log.u_bbr.use_lt_bw <<= 1;
2327 		log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
2328 		log.u_bbr.use_lt_bw <<= 1;
2329 		log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
2330 		log.u_bbr.use_lt_bw <<= 1;
2331 		log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
2332 		log.u_bbr.use_lt_bw <<= 1;
2333 		log.u_bbr.use_lt_bw |= rack->rc_dragged_bottom;
2334 		log.u_bbr.applimited = rack->r_ctl.rc_target_probertt_flight;
2335 		log.u_bbr.epoch = rack->r_ctl.rc_time_probertt_starts;
2336 		log.u_bbr.lt_epoch = rack->r_ctl.rc_time_probertt_entered;
2337 		log.u_bbr.cur_del_rate = rack->r_ctl.rc_lower_rtt_us_cts;
2338 		log.u_bbr.delRate = rack->r_ctl.rc_gp_srtt;
2339 		log.u_bbr.bw_inuse = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
2340 		log.u_bbr.bw_inuse <<= 32;
2341 		if (rsm)
2342 			log.u_bbr.bw_inuse |= ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]);
2343 		TCP_LOG_EVENTP(tp, NULL,
2344 		    &rack->rc_inp->inp_socket->so_rcv,
2345 		    &rack->rc_inp->inp_socket->so_snd,
2346 		    BBR_LOG_BBRRTT, 0,
2347 		    0, &log, false, &tv);
2348 
2349 
2350 	}
2351 }
2352 
2353 static void
2354 rack_log_rtt_sample(struct tcp_rack *rack, uint32_t rtt)
2355 {
2356 	/*
2357 	 * Log the rtt sample we are
2358 	 * applying to the srtt algorithm in
2359 	 * useconds.
2360 	 */
2361 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2362 		union tcp_log_stackspecific log;
2363 		struct timeval tv;
2364 
2365 		/* Convert our ms to a microsecond */
2366 		memset(&log, 0, sizeof(log));
2367 		log.u_bbr.flex1 = rtt;
2368 		log.u_bbr.flex2 = rack->r_ctl.ack_count;
2369 		log.u_bbr.flex3 = rack->r_ctl.sack_count;
2370 		log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move;
2371 		log.u_bbr.flex5 = rack->r_ctl.sack_moved_extra;
2372 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2373 		log.u_bbr.flex7 = 1;
2374 		log.u_bbr.flex8 = rack->sack_attack_disable;
2375 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2376 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2377 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2378 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2379 		log.u_bbr.pacing_gain = rack->r_must_retran;
2380 		/*
2381 		 * We capture in delRate the upper 32 bits as
2382 		 * the confidence level we had declared, and the
2383 		 * lower 32 bits as the actual RTT using the arrival
2384 		 * timestamp.
2385 		 */
2386 		log.u_bbr.delRate = rack->r_ctl.rack_rs.confidence;
2387 		log.u_bbr.delRate <<= 32;
2388 		log.u_bbr.delRate |= rack->r_ctl.rack_rs.rs_us_rtt;
2389 		/* Lets capture all the things that make up t_rtxcur */
2390 		log.u_bbr.applimited = rack_rto_min;
2391 		log.u_bbr.epoch = rack_rto_max;
2392 		log.u_bbr.lt_epoch = rack->r_ctl.timer_slop;
2393 		log.u_bbr.lost = rack_rto_min;
2394 		log.u_bbr.pkt_epoch = TICKS_2_USEC(tcp_rexmit_slop);
2395 		log.u_bbr.rttProp = RACK_REXMTVAL(rack->rc_tp);
2396 		log.u_bbr.bw_inuse = rack->r_ctl.act_rcv_time.tv_sec;
2397 		log.u_bbr.bw_inuse *= HPTS_USEC_IN_SEC;
2398 		log.u_bbr.bw_inuse += rack->r_ctl.act_rcv_time.tv_usec;
2399 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2400 		    &rack->rc_inp->inp_socket->so_rcv,
2401 		    &rack->rc_inp->inp_socket->so_snd,
2402 		    TCP_LOG_RTT, 0,
2403 		    0, &log, false, &tv);
2404 	}
2405 }
2406 
2407 static void
2408 rack_log_rtt_sample_calc(struct tcp_rack *rack, uint32_t rtt, uint32_t send_time, uint32_t ack_time, int where)
2409 {
2410 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
2411 		union tcp_log_stackspecific log;
2412 		struct timeval tv;
2413 
2414 		/* Convert our ms to a microsecond */
2415 		memset(&log, 0, sizeof(log));
2416 		log.u_bbr.flex1 = rtt;
2417 		log.u_bbr.flex2 = send_time;
2418 		log.u_bbr.flex3 = ack_time;
2419 		log.u_bbr.flex4 = where;
2420 		log.u_bbr.flex7 = 2;
2421 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2422 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2423 		    &rack->rc_inp->inp_socket->so_rcv,
2424 		    &rack->rc_inp->inp_socket->so_snd,
2425 		    TCP_LOG_RTT, 0,
2426 		    0, &log, false, &tv);
2427 	}
2428 }
2429 
2430 
2431 
2432 static inline void
2433 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick,  int event, int line)
2434 {
2435 	if (rack_verbose_logging && (tp->t_logstate != TCP_LOG_STATE_OFF)) {
2436 		union tcp_log_stackspecific log;
2437 		struct timeval tv;
2438 
2439 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2440 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2441 		log.u_bbr.flex1 = line;
2442 		log.u_bbr.flex2 = tick;
2443 		log.u_bbr.flex3 = tp->t_maxunacktime;
2444 		log.u_bbr.flex4 = tp->t_acktime;
2445 		log.u_bbr.flex8 = event;
2446 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2447 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2448 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2449 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2450 		log.u_bbr.pacing_gain = rack->r_must_retran;
2451 		TCP_LOG_EVENTP(tp, NULL,
2452 		    &rack->rc_inp->inp_socket->so_rcv,
2453 		    &rack->rc_inp->inp_socket->so_snd,
2454 		    BBR_LOG_PROGRESS, 0,
2455 		    0, &log, false, &tv);
2456 	}
2457 }
2458 
2459 static void
2460 rack_log_type_bbrsnd(struct tcp_rack *rack, uint32_t len, uint32_t slot, uint32_t cts, struct timeval *tv)
2461 {
2462 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2463 		union tcp_log_stackspecific log;
2464 
2465 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2466 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2467 		log.u_bbr.flex1 = slot;
2468 		if (rack->rack_no_prr)
2469 			log.u_bbr.flex2 = 0;
2470 		else
2471 			log.u_bbr.flex2 = rack->r_ctl.rc_prr_sndcnt;
2472 		log.u_bbr.flex7 = (0x0000ffff & rack->r_ctl.rc_hpts_flags);
2473 		log.u_bbr.flex8 = rack->rc_in_persist;
2474 		log.u_bbr.timeStamp = cts;
2475 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2476 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2477 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2478 		log.u_bbr.pacing_gain = rack->r_must_retran;
2479 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2480 		    &rack->rc_inp->inp_socket->so_rcv,
2481 		    &rack->rc_inp->inp_socket->so_snd,
2482 		    BBR_LOG_BBRSND, 0,
2483 		    0, &log, false, tv);
2484 	}
2485 }
2486 
2487 static void
2488 rack_log_doseg_done(struct tcp_rack *rack, uint32_t cts, int32_t nxt_pkt, int32_t did_out, int way_out, int nsegs)
2489 {
2490 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2491 		union tcp_log_stackspecific log;
2492 		struct timeval tv;
2493 
2494 		memset(&log, 0, sizeof(log));
2495 		log.u_bbr.flex1 = did_out;
2496 		log.u_bbr.flex2 = nxt_pkt;
2497 		log.u_bbr.flex3 = way_out;
2498 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
2499 		if (rack->rack_no_prr)
2500 			log.u_bbr.flex5 = 0;
2501 		else
2502 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2503 		log.u_bbr.flex6 = nsegs;
2504 		log.u_bbr.applimited = rack->r_ctl.rc_pace_min_segs;
2505 		log.u_bbr.flex7 = rack->rc_ack_can_sendout_data;	/* Do we have ack-can-send set */
2506 		log.u_bbr.flex7 <<= 1;
2507 		log.u_bbr.flex7 |= rack->r_fast_output;	/* is fast output primed */
2508 		log.u_bbr.flex7 <<= 1;
2509 		log.u_bbr.flex7 |= rack->r_wanted_output;	/* Do we want output */
2510 		log.u_bbr.flex8 = rack->rc_in_persist;
2511 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2512 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2513 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2514 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
2515 		log.u_bbr.use_lt_bw <<= 1;
2516 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
2517 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2518 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2519 		log.u_bbr.pacing_gain = rack->r_must_retran;
2520 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2521 		    &rack->rc_inp->inp_socket->so_rcv,
2522 		    &rack->rc_inp->inp_socket->so_snd,
2523 		    BBR_LOG_DOSEG_DONE, 0,
2524 		    0, &log, false, &tv);
2525 	}
2526 }
2527 
2528 static void
2529 rack_log_type_pacing_sizes(struct tcpcb *tp, struct tcp_rack *rack, uint32_t arg1, uint32_t arg2, uint32_t arg3, uint8_t frm)
2530 {
2531 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
2532 		union tcp_log_stackspecific log;
2533 		struct timeval tv;
2534 
2535 		memset(&log, 0, sizeof(log));
2536 		log.u_bbr.flex1 = rack->r_ctl.rc_pace_min_segs;
2537 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
2538 		log.u_bbr.flex4 = arg1;
2539 		log.u_bbr.flex5 = arg2;
2540 		log.u_bbr.flex6 = arg3;
2541 		log.u_bbr.flex8 = frm;
2542 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2543 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2544 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2545 		log.u_bbr.applimited = rack->r_ctl.rc_sacked;
2546 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2547 		log.u_bbr.pacing_gain = rack->r_must_retran;
2548 		TCP_LOG_EVENTP(tp, NULL, &tptosocket(tp)->so_rcv,
2549 		    &tptosocket(tp)->so_snd,
2550 		    TCP_HDWR_PACE_SIZE, 0, 0, &log, false, &tv);
2551 	}
2552 }
2553 
2554 static void
2555 rack_log_type_just_return(struct tcp_rack *rack, uint32_t cts, uint32_t tlen, uint32_t slot,
2556 			  uint8_t hpts_calling, int reason, uint32_t cwnd_to_use)
2557 {
2558 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2559 		union tcp_log_stackspecific log;
2560 		struct timeval tv;
2561 
2562 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2563 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2564 		log.u_bbr.flex1 = slot;
2565 		log.u_bbr.flex2 = rack->r_ctl.rc_hpts_flags;
2566 		log.u_bbr.flex4 = reason;
2567 		if (rack->rack_no_prr)
2568 			log.u_bbr.flex5 = 0;
2569 		else
2570 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2571 		log.u_bbr.flex7 = hpts_calling;
2572 		log.u_bbr.flex8 = rack->rc_in_persist;
2573 		log.u_bbr.lt_epoch = cwnd_to_use;
2574 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2575 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2576 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2577 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2578 		log.u_bbr.pacing_gain = rack->r_must_retran;
2579 		log.u_bbr.cwnd_gain = rack->rc_has_collapsed;
2580 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2581 		    &rack->rc_inp->inp_socket->so_rcv,
2582 		    &rack->rc_inp->inp_socket->so_snd,
2583 		    BBR_LOG_JUSTRET, 0,
2584 		    tlen, &log, false, &tv);
2585 	}
2586 }
2587 
2588 static void
2589 rack_log_to_cancel(struct tcp_rack *rack, int32_t hpts_removed, int line, uint32_t us_cts,
2590 		   struct timeval *tv, uint32_t flags_on_entry)
2591 {
2592 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2593 		union tcp_log_stackspecific log;
2594 
2595 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2596 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2597 		log.u_bbr.flex1 = line;
2598 		log.u_bbr.flex2 = rack->r_ctl.rc_last_output_to;
2599 		log.u_bbr.flex3 = flags_on_entry;
2600 		log.u_bbr.flex4 = us_cts;
2601 		if (rack->rack_no_prr)
2602 			log.u_bbr.flex5 = 0;
2603 		else
2604 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2605 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2606 		log.u_bbr.flex7 = hpts_removed;
2607 		log.u_bbr.flex8 = 1;
2608 		log.u_bbr.applimited = rack->r_ctl.rc_hpts_flags;
2609 		log.u_bbr.timeStamp = us_cts;
2610 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2611 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2612 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2613 		log.u_bbr.pacing_gain = rack->r_must_retran;
2614 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2615 		    &rack->rc_inp->inp_socket->so_rcv,
2616 		    &rack->rc_inp->inp_socket->so_snd,
2617 		    BBR_LOG_TIMERCANC, 0,
2618 		    0, &log, false, tv);
2619 	}
2620 }
2621 
2622 static void
2623 rack_log_alt_to_to_cancel(struct tcp_rack *rack,
2624 			  uint32_t flex1, uint32_t flex2,
2625 			  uint32_t flex3, uint32_t flex4,
2626 			  uint32_t flex5, uint32_t flex6,
2627 			  uint16_t flex7, uint8_t mod)
2628 {
2629 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2630 		union tcp_log_stackspecific log;
2631 		struct timeval tv;
2632 
2633 		if (mod == 1) {
2634 			/* No you can't use 1, its for the real to cancel */
2635 			return;
2636 		}
2637 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2638 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2639 		log.u_bbr.flex1 = flex1;
2640 		log.u_bbr.flex2 = flex2;
2641 		log.u_bbr.flex3 = flex3;
2642 		log.u_bbr.flex4 = flex4;
2643 		log.u_bbr.flex5 = flex5;
2644 		log.u_bbr.flex6 = flex6;
2645 		log.u_bbr.flex7 = flex7;
2646 		log.u_bbr.flex8 = mod;
2647 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2648 		    &rack->rc_inp->inp_socket->so_rcv,
2649 		    &rack->rc_inp->inp_socket->so_snd,
2650 		    BBR_LOG_TIMERCANC, 0,
2651 		    0, &log, false, &tv);
2652 	}
2653 }
2654 
2655 static void
2656 rack_log_to_processing(struct tcp_rack *rack, uint32_t cts, int32_t ret, int32_t timers)
2657 {
2658 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2659 		union tcp_log_stackspecific log;
2660 		struct timeval tv;
2661 
2662 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2663 		log.u_bbr.flex1 = timers;
2664 		log.u_bbr.flex2 = ret;
2665 		log.u_bbr.flex3 = rack->r_ctl.rc_timer_exp;
2666 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
2667 		log.u_bbr.flex5 = cts;
2668 		if (rack->rack_no_prr)
2669 			log.u_bbr.flex6 = 0;
2670 		else
2671 			log.u_bbr.flex6 = rack->r_ctl.rc_prr_sndcnt;
2672 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2673 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2674 		log.u_bbr.pacing_gain = rack->r_must_retran;
2675 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2676 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2677 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2678 		    &rack->rc_inp->inp_socket->so_rcv,
2679 		    &rack->rc_inp->inp_socket->so_snd,
2680 		    BBR_LOG_TO_PROCESS, 0,
2681 		    0, &log, false, &tv);
2682 	}
2683 }
2684 
2685 static void
2686 rack_log_to_prr(struct tcp_rack *rack, int frm, int orig_cwnd, int line)
2687 {
2688 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2689 		union tcp_log_stackspecific log;
2690 		struct timeval tv;
2691 
2692 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2693 		log.u_bbr.flex1 = rack->r_ctl.rc_prr_out;
2694 		log.u_bbr.flex2 = rack->r_ctl.rc_prr_recovery_fs;
2695 		if (rack->rack_no_prr)
2696 			log.u_bbr.flex3 = 0;
2697 		else
2698 			log.u_bbr.flex3 = rack->r_ctl.rc_prr_sndcnt;
2699 		log.u_bbr.flex4 = rack->r_ctl.rc_prr_delivered;
2700 		log.u_bbr.flex5 = rack->r_ctl.rc_sacked;
2701 		log.u_bbr.flex6 = rack->r_ctl.rc_holes_rxt;
2702 		log.u_bbr.flex7 = line;
2703 		log.u_bbr.flex8 = frm;
2704 		log.u_bbr.pkts_out = orig_cwnd;
2705 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2706 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2707 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
2708 		log.u_bbr.use_lt_bw <<= 1;
2709 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
2710 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2711 		    &rack->rc_inp->inp_socket->so_rcv,
2712 		    &rack->rc_inp->inp_socket->so_snd,
2713 		    BBR_LOG_BBRUPD, 0,
2714 		    0, &log, false, &tv);
2715 	}
2716 }
2717 
2718 #ifdef NETFLIX_EXP_DETECTION
2719 static void
2720 rack_log_sad(struct tcp_rack *rack, int event)
2721 {
2722 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2723 		union tcp_log_stackspecific log;
2724 		struct timeval tv;
2725 
2726 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2727 		log.u_bbr.flex1 = rack->r_ctl.sack_count;
2728 		log.u_bbr.flex2 = rack->r_ctl.ack_count;
2729 		log.u_bbr.flex3 = rack->r_ctl.sack_moved_extra;
2730 		log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move;
2731 		log.u_bbr.flex5 = rack->r_ctl.rc_num_maps_alloced;
2732 		log.u_bbr.flex6 = tcp_sack_to_ack_thresh;
2733 		log.u_bbr.pkts_out = tcp_sack_to_move_thresh;
2734 		log.u_bbr.lt_epoch = (tcp_force_detection << 8);
2735 		log.u_bbr.lt_epoch |= rack->do_detection;
2736 		log.u_bbr.applimited = tcp_map_minimum;
2737 		log.u_bbr.flex7 = rack->sack_attack_disable;
2738 		log.u_bbr.flex8 = event;
2739 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2740 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2741 		log.u_bbr.delivered = tcp_sad_decay_val;
2742 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2743 		    &rack->rc_inp->inp_socket->so_rcv,
2744 		    &rack->rc_inp->inp_socket->so_snd,
2745 		    TCP_SAD_DETECTION, 0,
2746 		    0, &log, false, &tv);
2747 	}
2748 }
2749 #endif
2750 
2751 static void
2752 rack_counter_destroy(void)
2753 {
2754 	counter_u64_free(rack_fto_send);
2755 	counter_u64_free(rack_fto_rsm_send);
2756 	counter_u64_free(rack_nfto_resend);
2757 	counter_u64_free(rack_hw_pace_init_fail);
2758 	counter_u64_free(rack_hw_pace_lost);
2759 	counter_u64_free(rack_non_fto_send);
2760 	counter_u64_free(rack_extended_rfo);
2761 	counter_u64_free(rack_ack_total);
2762 	counter_u64_free(rack_express_sack);
2763 	counter_u64_free(rack_sack_total);
2764 	counter_u64_free(rack_move_none);
2765 	counter_u64_free(rack_move_some);
2766 	counter_u64_free(rack_sack_attacks_detected);
2767 	counter_u64_free(rack_sack_attacks_reversed);
2768 	counter_u64_free(rack_sack_used_next_merge);
2769 	counter_u64_free(rack_sack_used_prev_merge);
2770 	counter_u64_free(rack_tlp_tot);
2771 	counter_u64_free(rack_tlp_newdata);
2772 	counter_u64_free(rack_tlp_retran);
2773 	counter_u64_free(rack_tlp_retran_bytes);
2774 	counter_u64_free(rack_to_tot);
2775 	counter_u64_free(rack_saw_enobuf);
2776 	counter_u64_free(rack_saw_enobuf_hw);
2777 	counter_u64_free(rack_saw_enetunreach);
2778 	counter_u64_free(rack_hot_alloc);
2779 	counter_u64_free(rack_to_alloc);
2780 	counter_u64_free(rack_to_alloc_hard);
2781 	counter_u64_free(rack_to_alloc_emerg);
2782 	counter_u64_free(rack_to_alloc_limited);
2783 	counter_u64_free(rack_alloc_limited_conns);
2784 	counter_u64_free(rack_split_limited);
2785 	counter_u64_free(rack_multi_single_eq);
2786 	counter_u64_free(rack_proc_non_comp_ack);
2787 	counter_u64_free(rack_sack_proc_all);
2788 	counter_u64_free(rack_sack_proc_restart);
2789 	counter_u64_free(rack_sack_proc_short);
2790 	counter_u64_free(rack_sack_skipped_acked);
2791 	counter_u64_free(rack_sack_splits);
2792 	counter_u64_free(rack_input_idle_reduces);
2793 	counter_u64_free(rack_collapsed_win);
2794 	counter_u64_free(rack_collapsed_win_rxt);
2795 	counter_u64_free(rack_collapsed_win_rxt_bytes);
2796 	counter_u64_free(rack_collapsed_win_seen);
2797 	counter_u64_free(rack_try_scwnd);
2798 	counter_u64_free(rack_persists_sends);
2799 	counter_u64_free(rack_persists_acks);
2800 	counter_u64_free(rack_persists_loss);
2801 	counter_u64_free(rack_persists_lost_ends);
2802 #ifdef INVARIANTS
2803 	counter_u64_free(rack_adjust_map_bw);
2804 #endif
2805 	COUNTER_ARRAY_FREE(rack_out_size, TCP_MSS_ACCT_SIZE);
2806 	COUNTER_ARRAY_FREE(rack_opts_arry, RACK_OPTS_SIZE);
2807 }
2808 
2809 static struct rack_sendmap *
2810 rack_alloc(struct tcp_rack *rack)
2811 {
2812 	struct rack_sendmap *rsm;
2813 
2814 	/*
2815 	 * First get the top of the list it in
2816 	 * theory is the "hottest" rsm we have,
2817 	 * possibly just freed by ack processing.
2818 	 */
2819 	if (rack->rc_free_cnt > rack_free_cache) {
2820 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
2821 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
2822 		counter_u64_add(rack_hot_alloc, 1);
2823 		rack->rc_free_cnt--;
2824 		return (rsm);
2825 	}
2826 	/*
2827 	 * Once we get under our free cache we probably
2828 	 * no longer have a "hot" one available. Lets
2829 	 * get one from UMA.
2830 	 */
2831 	rsm = uma_zalloc(rack_zone, M_NOWAIT);
2832 	if (rsm) {
2833 		rack->r_ctl.rc_num_maps_alloced++;
2834 		counter_u64_add(rack_to_alloc, 1);
2835 		return (rsm);
2836 	}
2837 	/*
2838 	 * Dig in to our aux rsm's (the last two) since
2839 	 * UMA failed to get us one.
2840 	 */
2841 	if (rack->rc_free_cnt) {
2842 		counter_u64_add(rack_to_alloc_emerg, 1);
2843 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
2844 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
2845 		rack->rc_free_cnt--;
2846 		return (rsm);
2847 	}
2848 	return (NULL);
2849 }
2850 
2851 static struct rack_sendmap *
2852 rack_alloc_full_limit(struct tcp_rack *rack)
2853 {
2854 	if ((V_tcp_map_entries_limit > 0) &&
2855 	    (rack->do_detection == 0) &&
2856 	    (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
2857 		counter_u64_add(rack_to_alloc_limited, 1);
2858 		if (!rack->alloc_limit_reported) {
2859 			rack->alloc_limit_reported = 1;
2860 			counter_u64_add(rack_alloc_limited_conns, 1);
2861 		}
2862 		return (NULL);
2863 	}
2864 	return (rack_alloc(rack));
2865 }
2866 
2867 /* wrapper to allocate a sendmap entry, subject to a specific limit */
2868 static struct rack_sendmap *
2869 rack_alloc_limit(struct tcp_rack *rack, uint8_t limit_type)
2870 {
2871 	struct rack_sendmap *rsm;
2872 
2873 	if (limit_type) {
2874 		/* currently there is only one limit type */
2875 		if (V_tcp_map_split_limit > 0 &&
2876 		    (rack->do_detection == 0) &&
2877 		    rack->r_ctl.rc_num_split_allocs >= V_tcp_map_split_limit) {
2878 			counter_u64_add(rack_split_limited, 1);
2879 			if (!rack->alloc_limit_reported) {
2880 				rack->alloc_limit_reported = 1;
2881 				counter_u64_add(rack_alloc_limited_conns, 1);
2882 			}
2883 			return (NULL);
2884 		}
2885 	}
2886 
2887 	/* allocate and mark in the limit type, if set */
2888 	rsm = rack_alloc(rack);
2889 	if (rsm != NULL && limit_type) {
2890 		rsm->r_limit_type = limit_type;
2891 		rack->r_ctl.rc_num_split_allocs++;
2892 	}
2893 	return (rsm);
2894 }
2895 
2896 static void
2897 rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm)
2898 {
2899 	if (rsm->r_flags & RACK_APP_LIMITED) {
2900 		if (rack->r_ctl.rc_app_limited_cnt > 0) {
2901 			rack->r_ctl.rc_app_limited_cnt--;
2902 		}
2903 	}
2904 	if (rsm->r_limit_type) {
2905 		/* currently there is only one limit type */
2906 		rack->r_ctl.rc_num_split_allocs--;
2907 	}
2908 	if (rsm == rack->r_ctl.rc_first_appl) {
2909 		if (rack->r_ctl.rc_app_limited_cnt == 0)
2910 			rack->r_ctl.rc_first_appl = NULL;
2911 		else {
2912 			/* Follow the next one out */
2913 			struct rack_sendmap fe;
2914 
2915 			fe.r_start = rsm->r_nseq_appl;
2916 			rack->r_ctl.rc_first_appl = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
2917 		}
2918 	}
2919 	if (rsm == rack->r_ctl.rc_resend)
2920 		rack->r_ctl.rc_resend = NULL;
2921 	if (rsm == rack->r_ctl.rc_end_appl)
2922 		rack->r_ctl.rc_end_appl = NULL;
2923 	if (rack->r_ctl.rc_tlpsend == rsm)
2924 		rack->r_ctl.rc_tlpsend = NULL;
2925 	if (rack->r_ctl.rc_sacklast == rsm)
2926 		rack->r_ctl.rc_sacklast = NULL;
2927 	memset(rsm, 0, sizeof(struct rack_sendmap));
2928 	TAILQ_INSERT_HEAD(&rack->r_ctl.rc_free, rsm, r_tnext);
2929 	rack->rc_free_cnt++;
2930 }
2931 
2932 static void
2933 rack_free_trim(struct tcp_rack *rack)
2934 {
2935 	struct rack_sendmap *rsm;
2936 
2937 	/*
2938 	 * Free up all the tail entries until
2939 	 * we get our list down to the limit.
2940 	 */
2941 	while (rack->rc_free_cnt > rack_free_cache) {
2942 		rsm = TAILQ_LAST(&rack->r_ctl.rc_free, rack_head);
2943 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
2944 		rack->rc_free_cnt--;
2945 		uma_zfree(rack_zone, rsm);
2946 	}
2947 }
2948 
2949 
2950 static uint32_t
2951 rack_get_measure_window(struct tcpcb *tp, struct tcp_rack *rack)
2952 {
2953 	uint64_t srtt, bw, len, tim;
2954 	uint32_t segsiz, def_len, minl;
2955 
2956 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
2957 	def_len = rack_def_data_window * segsiz;
2958 	if (rack->rc_gp_filled == 0) {
2959 		/*
2960 		 * We have no measurement (IW is in flight?) so
2961 		 * we can only guess using our data_window sysctl
2962 		 * value (usually 20MSS).
2963 		 */
2964 		return (def_len);
2965 	}
2966 	/*
2967 	 * Now we have a number of factors to consider.
2968 	 *
2969 	 * 1) We have a desired BDP which is usually
2970 	 *    at least 2.
2971 	 * 2) We have a minimum number of rtt's usually 1 SRTT
2972 	 *    but we allow it too to be more.
2973 	 * 3) We want to make sure a measurement last N useconds (if
2974 	 *    we have set rack_min_measure_usec.
2975 	 *
2976 	 * We handle the first concern here by trying to create a data
2977 	 * window of max(rack_def_data_window, DesiredBDP). The
2978 	 * second concern we handle in not letting the measurement
2979 	 * window end normally until at least the required SRTT's
2980 	 * have gone by which is done further below in
2981 	 * rack_enough_for_measurement(). Finally the third concern
2982 	 * we also handle here by calculating how long that time
2983 	 * would take at the current BW and then return the
2984 	 * max of our first calculation and that length. Note
2985 	 * that if rack_min_measure_usec is 0, we don't deal
2986 	 * with concern 3. Also for both Concern 1 and 3 an
2987 	 * application limited period could end the measurement
2988 	 * earlier.
2989 	 *
2990 	 * So lets calculate the BDP with the "known" b/w using
2991 	 * the SRTT has our rtt and then multiply it by the
2992 	 * goal.
2993 	 */
2994 	bw = rack_get_bw(rack);
2995 	srtt = (uint64_t)tp->t_srtt;
2996 	len = bw * srtt;
2997 	len /= (uint64_t)HPTS_USEC_IN_SEC;
2998 	len *= max(1, rack_goal_bdp);
2999 	/* Now we need to round up to the nearest MSS */
3000 	len = roundup(len, segsiz);
3001 	if (rack_min_measure_usec) {
3002 		/* Now calculate our min length for this b/w */
3003 		tim = rack_min_measure_usec;
3004 		minl = (tim * bw) / (uint64_t)HPTS_USEC_IN_SEC;
3005 		if (minl == 0)
3006 			minl = 1;
3007 		minl = roundup(minl, segsiz);
3008 		if (len < minl)
3009 			len = minl;
3010 	}
3011 	/*
3012 	 * Now if we have a very small window we want
3013 	 * to attempt to get the window that is
3014 	 * as small as possible. This happens on
3015 	 * low b/w connections and we don't want to
3016 	 * span huge numbers of rtt's between measurements.
3017 	 *
3018 	 * We basically include 2 over our "MIN window" so
3019 	 * that the measurement can be shortened (possibly) by
3020 	 * an ack'ed packet.
3021 	 */
3022 	if (len < def_len)
3023 		return (max((uint32_t)len, ((MIN_GP_WIN+2) * segsiz)));
3024 	else
3025 		return (max((uint32_t)len, def_len));
3026 
3027 }
3028 
3029 static int
3030 rack_enough_for_measurement(struct tcpcb *tp, struct tcp_rack *rack, tcp_seq th_ack, uint8_t *quality)
3031 {
3032 	uint32_t tim, srtts, segsiz;
3033 
3034 	/*
3035 	 * Has enough time passed for the GP measurement to be valid?
3036 	 */
3037 	if ((tp->snd_max == tp->snd_una) ||
3038 	    (th_ack == tp->snd_max)){
3039 		/* All is acked */
3040 		*quality = RACK_QUALITY_ALLACKED;
3041 		return (1);
3042 	}
3043 	if (SEQ_LT(th_ack, tp->gput_seq)) {
3044 		/* Not enough bytes yet */
3045 		return (0);
3046 	}
3047 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
3048 	if (SEQ_LT(th_ack, tp->gput_ack) &&
3049 	    ((th_ack - tp->gput_seq) < max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
3050 		/* Not enough bytes yet */
3051 		return (0);
3052 	}
3053 	if (rack->r_ctl.rc_first_appl &&
3054 	    (SEQ_GEQ(th_ack, rack->r_ctl.rc_first_appl->r_end))) {
3055 		/*
3056 		 * We are up to the app limited send point
3057 		 * we have to measure irrespective of the time..
3058 		 */
3059 		*quality = RACK_QUALITY_APPLIMITED;
3060 		return (1);
3061 	}
3062 	/* Now what about time? */
3063 	srtts = (rack->r_ctl.rc_gp_srtt * rack_min_srtts);
3064 	tim = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - tp->gput_ts;
3065 	if (tim >= srtts) {
3066 		*quality = RACK_QUALITY_HIGH;
3067 		return (1);
3068 	}
3069 	/* Nope not even a full SRTT has passed */
3070 	return (0);
3071 }
3072 
3073 static void
3074 rack_log_timely(struct tcp_rack *rack,
3075 		uint32_t logged, uint64_t cur_bw, uint64_t low_bnd,
3076 		uint64_t up_bnd, int line, uint8_t method)
3077 {
3078 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
3079 		union tcp_log_stackspecific log;
3080 		struct timeval tv;
3081 
3082 		memset(&log, 0, sizeof(log));
3083 		log.u_bbr.flex1 = logged;
3084 		log.u_bbr.flex2 = rack->rc_gp_timely_inc_cnt;
3085 		log.u_bbr.flex2 <<= 4;
3086 		log.u_bbr.flex2 |= rack->rc_gp_timely_dec_cnt;
3087 		log.u_bbr.flex2 <<= 4;
3088 		log.u_bbr.flex2 |= rack->rc_gp_incr;
3089 		log.u_bbr.flex2 <<= 4;
3090 		log.u_bbr.flex2 |= rack->rc_gp_bwred;
3091 		log.u_bbr.flex3 = rack->rc_gp_incr;
3092 		log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
3093 		log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ca;
3094 		log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_rec;
3095 		log.u_bbr.flex7 = rack->rc_gp_bwred;
3096 		log.u_bbr.flex8 = method;
3097 		log.u_bbr.cur_del_rate = cur_bw;
3098 		log.u_bbr.delRate = low_bnd;
3099 		log.u_bbr.bw_inuse = up_bnd;
3100 		log.u_bbr.rttProp = rack_get_bw(rack);
3101 		log.u_bbr.pkt_epoch = line;
3102 		log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
3103 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3104 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3105 		log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
3106 		log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
3107 		log.u_bbr.cwnd_gain = rack->rc_dragged_bottom;
3108 		log.u_bbr.cwnd_gain <<= 1;
3109 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_rec;
3110 		log.u_bbr.cwnd_gain <<= 1;
3111 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
3112 		log.u_bbr.cwnd_gain <<= 1;
3113 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
3114 		log.u_bbr.lost = rack->r_ctl.rc_loss_count;
3115 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3116 		    &rack->rc_inp->inp_socket->so_rcv,
3117 		    &rack->rc_inp->inp_socket->so_snd,
3118 		    TCP_TIMELY_WORK, 0,
3119 		    0, &log, false, &tv);
3120 	}
3121 }
3122 
3123 static int
3124 rack_bw_can_be_raised(struct tcp_rack *rack, uint64_t cur_bw, uint64_t last_bw_est, uint16_t mult)
3125 {
3126 	/*
3127 	 * Before we increase we need to know if
3128 	 * the estimate just made was less than
3129 	 * our pacing goal (i.e. (cur_bw * mult) > last_bw_est)
3130 	 *
3131 	 * If we already are pacing at a fast enough
3132 	 * rate to push us faster there is no sense of
3133 	 * increasing.
3134 	 *
3135 	 * We first caculate our actual pacing rate (ss or ca multiplier
3136 	 * times our cur_bw).
3137 	 *
3138 	 * Then we take the last measured rate and multipy by our
3139 	 * maximum pacing overage to give us a max allowable rate.
3140 	 *
3141 	 * If our act_rate is smaller than our max_allowable rate
3142 	 * then we should increase. Else we should hold steady.
3143 	 *
3144 	 */
3145 	uint64_t act_rate, max_allow_rate;
3146 
3147 	if (rack_timely_no_stopping)
3148 		return (1);
3149 
3150 	if ((cur_bw == 0) || (last_bw_est == 0)) {
3151 		/*
3152 		 * Initial startup case or
3153 		 * everything is acked case.
3154 		 */
3155 		rack_log_timely(rack,  mult, cur_bw, 0, 0,
3156 				__LINE__, 9);
3157 		return (1);
3158 	}
3159 	if (mult <= 100) {
3160 		/*
3161 		 * We can always pace at or slightly above our rate.
3162 		 */
3163 		rack_log_timely(rack,  mult, cur_bw, 0, 0,
3164 				__LINE__, 9);
3165 		return (1);
3166 	}
3167 	act_rate = cur_bw * (uint64_t)mult;
3168 	act_rate /= 100;
3169 	max_allow_rate = last_bw_est * ((uint64_t)rack_max_per_above + (uint64_t)100);
3170 	max_allow_rate /= 100;
3171 	if (act_rate < max_allow_rate) {
3172 		/*
3173 		 * Here the rate we are actually pacing at
3174 		 * is smaller than 10% above our last measurement.
3175 		 * This means we are pacing below what we would
3176 		 * like to try to achieve (plus some wiggle room).
3177 		 */
3178 		rack_log_timely(rack,  mult, cur_bw, act_rate, max_allow_rate,
3179 				__LINE__, 9);
3180 		return (1);
3181 	} else {
3182 		/*
3183 		 * Here we are already pacing at least rack_max_per_above(10%)
3184 		 * what we are getting back. This indicates most likely
3185 		 * that we are being limited (cwnd/rwnd/app) and can't
3186 		 * get any more b/w. There is no sense of trying to
3187 		 * raise up the pacing rate its not speeding us up
3188 		 * and we already are pacing faster than we are getting.
3189 		 */
3190 		rack_log_timely(rack,  mult, cur_bw, act_rate, max_allow_rate,
3191 				__LINE__, 8);
3192 		return (0);
3193 	}
3194 }
3195 
3196 static void
3197 rack_validate_multipliers_at_or_above100(struct tcp_rack *rack)
3198 {
3199 	/*
3200 	 * When we drag bottom, we want to assure
3201 	 * that no multiplier is below 1.0, if so
3202 	 * we want to restore it to at least that.
3203 	 */
3204 	if (rack->r_ctl.rack_per_of_gp_rec  < 100) {
3205 		/* This is unlikely we usually do not touch recovery */
3206 		rack->r_ctl.rack_per_of_gp_rec = 100;
3207 	}
3208 	if (rack->r_ctl.rack_per_of_gp_ca < 100) {
3209 		rack->r_ctl.rack_per_of_gp_ca = 100;
3210 	}
3211 	if (rack->r_ctl.rack_per_of_gp_ss < 100) {
3212 		rack->r_ctl.rack_per_of_gp_ss = 100;
3213 	}
3214 }
3215 
3216 static void
3217 rack_validate_multipliers_at_or_below_100(struct tcp_rack *rack)
3218 {
3219 	if (rack->r_ctl.rack_per_of_gp_ca > 100) {
3220 		rack->r_ctl.rack_per_of_gp_ca = 100;
3221 	}
3222 	if (rack->r_ctl.rack_per_of_gp_ss > 100) {
3223 		rack->r_ctl.rack_per_of_gp_ss = 100;
3224 	}
3225 }
3226 
3227 static void
3228 rack_increase_bw_mul(struct tcp_rack *rack, int timely_says, uint64_t cur_bw, uint64_t last_bw_est, int override)
3229 {
3230 	int32_t  calc, logged, plus;
3231 
3232 	logged = 0;
3233 
3234 	if (override) {
3235 		/*
3236 		 * override is passed when we are
3237 		 * loosing b/w and making one last
3238 		 * gasp at trying to not loose out
3239 		 * to a new-reno flow.
3240 		 */
3241 		goto extra_boost;
3242 	}
3243 	/* In classic timely we boost by 5x if we have 5 increases in a row, lets not */
3244 	if (rack->rc_gp_incr &&
3245 	    ((rack->rc_gp_timely_inc_cnt + 1) >= RACK_TIMELY_CNT_BOOST)) {
3246 		/*
3247 		 * Reset and get 5 strokes more before the boost. Note
3248 		 * that the count is 0 based so we have to add one.
3249 		 */
3250 extra_boost:
3251 		plus = (uint32_t)rack_gp_increase_per * RACK_TIMELY_CNT_BOOST;
3252 		rack->rc_gp_timely_inc_cnt = 0;
3253 	} else
3254 		plus = (uint32_t)rack_gp_increase_per;
3255 	/* Must be at least 1% increase for true timely increases */
3256 	if ((plus < 1) &&
3257 	    ((rack->r_ctl.rc_rtt_diff <= 0) || (timely_says <= 0)))
3258 		plus = 1;
3259 	if (rack->rc_gp_saw_rec &&
3260 	    (rack->rc_gp_no_rec_chg == 0) &&
3261 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3262 				  rack->r_ctl.rack_per_of_gp_rec)) {
3263 		/* We have been in recovery ding it too */
3264 		calc = rack->r_ctl.rack_per_of_gp_rec + plus;
3265 		if (calc > 0xffff)
3266 			calc = 0xffff;
3267 		logged |= 1;
3268 		rack->r_ctl.rack_per_of_gp_rec = (uint16_t)calc;
3269 		if (rack_per_upper_bound_ss &&
3270 		    (rack->rc_dragged_bottom == 0) &&
3271 		    (rack->r_ctl.rack_per_of_gp_rec > rack_per_upper_bound_ss))
3272 			rack->r_ctl.rack_per_of_gp_rec = rack_per_upper_bound_ss;
3273 	}
3274 	if (rack->rc_gp_saw_ca &&
3275 	    (rack->rc_gp_saw_ss == 0) &&
3276 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3277 				  rack->r_ctl.rack_per_of_gp_ca)) {
3278 		/* In CA */
3279 		calc = rack->r_ctl.rack_per_of_gp_ca + plus;
3280 		if (calc > 0xffff)
3281 			calc = 0xffff;
3282 		logged |= 2;
3283 		rack->r_ctl.rack_per_of_gp_ca = (uint16_t)calc;
3284 		if (rack_per_upper_bound_ca &&
3285 		    (rack->rc_dragged_bottom == 0) &&
3286 		    (rack->r_ctl.rack_per_of_gp_ca > rack_per_upper_bound_ca))
3287 			rack->r_ctl.rack_per_of_gp_ca = rack_per_upper_bound_ca;
3288 	}
3289 	if (rack->rc_gp_saw_ss &&
3290 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3291 				  rack->r_ctl.rack_per_of_gp_ss)) {
3292 		/* In SS */
3293 		calc = rack->r_ctl.rack_per_of_gp_ss + plus;
3294 		if (calc > 0xffff)
3295 			calc = 0xffff;
3296 		rack->r_ctl.rack_per_of_gp_ss = (uint16_t)calc;
3297 		if (rack_per_upper_bound_ss &&
3298 		    (rack->rc_dragged_bottom == 0) &&
3299 		    (rack->r_ctl.rack_per_of_gp_ss > rack_per_upper_bound_ss))
3300 			rack->r_ctl.rack_per_of_gp_ss = rack_per_upper_bound_ss;
3301 		logged |= 4;
3302 	}
3303 	if (logged &&
3304 	    (rack->rc_gp_incr == 0)){
3305 		/* Go into increment mode */
3306 		rack->rc_gp_incr = 1;
3307 		rack->rc_gp_timely_inc_cnt = 0;
3308 	}
3309 	if (rack->rc_gp_incr &&
3310 	    logged &&
3311 	    (rack->rc_gp_timely_inc_cnt < RACK_TIMELY_CNT_BOOST)) {
3312 		rack->rc_gp_timely_inc_cnt++;
3313 	}
3314 	rack_log_timely(rack,  logged, plus, 0, 0,
3315 			__LINE__, 1);
3316 }
3317 
3318 static uint32_t
3319 rack_get_decrease(struct tcp_rack *rack, uint32_t curper, int32_t rtt_diff)
3320 {
3321 	/*
3322 	 * norm_grad = rtt_diff / minrtt;
3323 	 * new_per = curper * (1 - B * norm_grad)
3324 	 *
3325 	 * B = rack_gp_decrease_per (default 10%)
3326 	 * rtt_dif = input var current rtt-diff
3327 	 * curper = input var current percentage
3328 	 * minrtt = from rack filter
3329 	 *
3330 	 */
3331 	uint64_t perf;
3332 
3333 	perf = (((uint64_t)curper * ((uint64_t)1000000 -
3334 		    ((uint64_t)rack_gp_decrease_per * (uint64_t)10000 *
3335 		     (((uint64_t)rtt_diff * (uint64_t)1000000)/
3336 		      (uint64_t)get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt)))/
3337 		     (uint64_t)1000000)) /
3338 		(uint64_t)1000000);
3339 	if (perf > curper) {
3340 		/* TSNH */
3341 		perf = curper - 1;
3342 	}
3343 	return ((uint32_t)perf);
3344 }
3345 
3346 static uint32_t
3347 rack_decrease_highrtt(struct tcp_rack *rack, uint32_t curper, uint32_t rtt)
3348 {
3349 	/*
3350 	 *                                   highrttthresh
3351 	 * result = curper * (1 - (B * ( 1 -  ------          ))
3352 	 *                                     gp_srtt
3353 	 *
3354 	 * B = rack_gp_decrease_per (default 10%)
3355 	 * highrttthresh = filter_min * rack_gp_rtt_maxmul
3356 	 */
3357 	uint64_t perf;
3358 	uint32_t highrttthresh;
3359 
3360 	highrttthresh = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
3361 
3362 	perf = (((uint64_t)curper * ((uint64_t)1000000 -
3363 				     ((uint64_t)rack_gp_decrease_per * ((uint64_t)1000000 -
3364 					((uint64_t)highrttthresh * (uint64_t)1000000) /
3365 						    (uint64_t)rtt)) / 100)) /(uint64_t)1000000);
3366 	return (perf);
3367 }
3368 
3369 static void
3370 rack_decrease_bw_mul(struct tcp_rack *rack, int timely_says, uint32_t rtt, int32_t rtt_diff)
3371 {
3372 	uint64_t logvar, logvar2, logvar3;
3373 	uint32_t logged, new_per, ss_red, ca_red, rec_red, alt, val;
3374 
3375 	if (rack->rc_gp_incr) {
3376 		/* Turn off increment counting */
3377 		rack->rc_gp_incr = 0;
3378 		rack->rc_gp_timely_inc_cnt = 0;
3379 	}
3380 	ss_red = ca_red = rec_red = 0;
3381 	logged = 0;
3382 	/* Calculate the reduction value */
3383 	if (rtt_diff < 0) {
3384 		rtt_diff *= -1;
3385 	}
3386 	/* Must be at least 1% reduction */
3387 	if (rack->rc_gp_saw_rec && (rack->rc_gp_no_rec_chg == 0)) {
3388 		/* We have been in recovery ding it too */
3389 		if (timely_says == 2) {
3390 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_rec, rtt);
3391 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3392 			if (alt < new_per)
3393 				val = alt;
3394 			else
3395 				val = new_per;
3396 		} else
3397 			 val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3398 		if (rack->r_ctl.rack_per_of_gp_rec > val) {
3399 			rec_red = (rack->r_ctl.rack_per_of_gp_rec - val);
3400 			rack->r_ctl.rack_per_of_gp_rec = (uint16_t)val;
3401 		} else {
3402 			rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
3403 			rec_red = 0;
3404 		}
3405 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_rec)
3406 			rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
3407 		logged |= 1;
3408 	}
3409 	if (rack->rc_gp_saw_ss) {
3410 		/* Sent in SS */
3411 		if (timely_says == 2) {
3412 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ss, rtt);
3413 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3414 			if (alt < new_per)
3415 				val = alt;
3416 			else
3417 				val = new_per;
3418 		} else
3419 			val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ss, rtt_diff);
3420 		if (rack->r_ctl.rack_per_of_gp_ss > new_per) {
3421 			ss_red = rack->r_ctl.rack_per_of_gp_ss - val;
3422 			rack->r_ctl.rack_per_of_gp_ss = (uint16_t)val;
3423 		} else {
3424 			ss_red = new_per;
3425 			rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
3426 			logvar = new_per;
3427 			logvar <<= 32;
3428 			logvar |= alt;
3429 			logvar2 = (uint32_t)rtt;
3430 			logvar2 <<= 32;
3431 			logvar2 |= (uint32_t)rtt_diff;
3432 			logvar3 = rack_gp_rtt_maxmul;
3433 			logvar3 <<= 32;
3434 			logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3435 			rack_log_timely(rack, timely_says,
3436 					logvar2, logvar3,
3437 					logvar, __LINE__, 10);
3438 		}
3439 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ss)
3440 			rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
3441 		logged |= 4;
3442 	} else if (rack->rc_gp_saw_ca) {
3443 		/* Sent in CA */
3444 		if (timely_says == 2) {
3445 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ca, rtt);
3446 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3447 			if (alt < new_per)
3448 				val = alt;
3449 			else
3450 				val = new_per;
3451 		} else
3452 			val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ca, rtt_diff);
3453 		if (rack->r_ctl.rack_per_of_gp_ca > val) {
3454 			ca_red = rack->r_ctl.rack_per_of_gp_ca - val;
3455 			rack->r_ctl.rack_per_of_gp_ca = (uint16_t)val;
3456 		} else {
3457 			rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
3458 			ca_red = 0;
3459 			logvar = new_per;
3460 			logvar <<= 32;
3461 			logvar |= alt;
3462 			logvar2 = (uint32_t)rtt;
3463 			logvar2 <<= 32;
3464 			logvar2 |= (uint32_t)rtt_diff;
3465 			logvar3 = rack_gp_rtt_maxmul;
3466 			logvar3 <<= 32;
3467 			logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3468 			rack_log_timely(rack, timely_says,
3469 					logvar2, logvar3,
3470 					logvar, __LINE__, 10);
3471 		}
3472 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ca)
3473 			rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
3474 		logged |= 2;
3475 	}
3476 	if (rack->rc_gp_timely_dec_cnt < 0x7) {
3477 		rack->rc_gp_timely_dec_cnt++;
3478 		if (rack_timely_dec_clear &&
3479 		    (rack->rc_gp_timely_dec_cnt == rack_timely_dec_clear))
3480 			rack->rc_gp_timely_dec_cnt = 0;
3481 	}
3482 	logvar = ss_red;
3483 	logvar <<= 32;
3484 	logvar |= ca_red;
3485 	rack_log_timely(rack,  logged, rec_red, rack_per_lower_bound, logvar,
3486 			__LINE__, 2);
3487 }
3488 
3489 static void
3490 rack_log_rtt_shrinks(struct tcp_rack *rack, uint32_t us_cts,
3491 		     uint32_t rtt, uint32_t line, uint8_t reas)
3492 {
3493 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
3494 		union tcp_log_stackspecific log;
3495 		struct timeval tv;
3496 
3497 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3498 		log.u_bbr.flex1 = line;
3499 		log.u_bbr.flex2 = rack->r_ctl.rc_time_probertt_starts;
3500 		log.u_bbr.flex3 = rack->r_ctl.rc_lower_rtt_us_cts;
3501 		log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
3502 		log.u_bbr.flex5 = rtt;
3503 		log.u_bbr.flex6 = rack->rc_highly_buffered;
3504 		log.u_bbr.flex6 <<= 1;
3505 		log.u_bbr.flex6 |= rack->forced_ack;
3506 		log.u_bbr.flex6 <<= 1;
3507 		log.u_bbr.flex6 |= rack->rc_gp_dyn_mul;
3508 		log.u_bbr.flex6 <<= 1;
3509 		log.u_bbr.flex6 |= rack->in_probe_rtt;
3510 		log.u_bbr.flex6 <<= 1;
3511 		log.u_bbr.flex6 |= rack->measure_saw_probe_rtt;
3512 		log.u_bbr.flex7 = rack->r_ctl.rack_per_of_gp_probertt;
3513 		log.u_bbr.pacing_gain = rack->r_ctl.rack_per_of_gp_ca;
3514 		log.u_bbr.cwnd_gain = rack->r_ctl.rack_per_of_gp_rec;
3515 		log.u_bbr.flex8 = reas;
3516 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3517 		log.u_bbr.delRate = rack_get_bw(rack);
3518 		log.u_bbr.cur_del_rate = rack->r_ctl.rc_highest_us_rtt;
3519 		log.u_bbr.cur_del_rate <<= 32;
3520 		log.u_bbr.cur_del_rate |= rack->r_ctl.rc_lowest_us_rtt;
3521 		log.u_bbr.applimited = rack->r_ctl.rc_time_probertt_entered;
3522 		log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
3523 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3524 		log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
3525 		log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
3526 		log.u_bbr.pkt_epoch = rack->r_ctl.rc_lower_rtt_us_cts;
3527 		log.u_bbr.delivered = rack->r_ctl.rc_target_probertt_flight;
3528 		log.u_bbr.lost = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3529 		log.u_bbr.rttProp = us_cts;
3530 		log.u_bbr.rttProp <<= 32;
3531 		log.u_bbr.rttProp |= rack->r_ctl.rc_entry_gp_rtt;
3532 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3533 		    &rack->rc_inp->inp_socket->so_rcv,
3534 		    &rack->rc_inp->inp_socket->so_snd,
3535 		    BBR_LOG_RTT_SHRINKS, 0,
3536 		    0, &log, false, &rack->r_ctl.act_rcv_time);
3537 	}
3538 }
3539 
3540 static void
3541 rack_set_prtt_target(struct tcp_rack *rack, uint32_t segsiz, uint32_t rtt)
3542 {
3543 	uint64_t bwdp;
3544 
3545 	bwdp = rack_get_bw(rack);
3546 	bwdp *= (uint64_t)rtt;
3547 	bwdp /= (uint64_t)HPTS_USEC_IN_SEC;
3548 	rack->r_ctl.rc_target_probertt_flight = roundup((uint32_t)bwdp, segsiz);
3549 	if (rack->r_ctl.rc_target_probertt_flight < (segsiz * rack_timely_min_segs)) {
3550 		/*
3551 		 * A window protocol must be able to have 4 packets
3552 		 * outstanding as the floor in order to function
3553 		 * (especially considering delayed ack :D).
3554 		 */
3555 		rack->r_ctl.rc_target_probertt_flight = (segsiz * rack_timely_min_segs);
3556 	}
3557 }
3558 
3559 static void
3560 rack_enter_probertt(struct tcp_rack *rack, uint32_t us_cts)
3561 {
3562 	/**
3563 	 * ProbeRTT is a bit different in rack_pacing than in
3564 	 * BBR. It is like BBR in that it uses the lowering of
3565 	 * the RTT as a signal that we saw something new and
3566 	 * counts from there for how long between. But it is
3567 	 * different in that its quite simple. It does not
3568 	 * play with the cwnd and wait until we get down
3569 	 * to N segments outstanding and hold that for
3570 	 * 200ms. Instead it just sets the pacing reduction
3571 	 * rate to a set percentage (70 by default) and hold
3572 	 * that for a number of recent GP Srtt's.
3573 	 */
3574 	uint32_t segsiz;
3575 
3576 	if (rack->rc_gp_dyn_mul == 0)
3577 		return;
3578 
3579 	if (rack->rc_tp->snd_max == rack->rc_tp->snd_una) {
3580 		/* We are idle */
3581 		return;
3582 	}
3583 	if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
3584 	    SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
3585 		/*
3586 		 * Stop the goodput now, the idea here is
3587 		 * that future measurements with in_probe_rtt
3588 		 * won't register if they are not greater so
3589 		 * we want to get what info (if any) is available
3590 		 * now.
3591 		 */
3592 		rack_do_goodput_measurement(rack->rc_tp, rack,
3593 					    rack->rc_tp->snd_una, __LINE__,
3594 					    RACK_QUALITY_PROBERTT);
3595 	}
3596 	rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
3597 	rack->r_ctl.rc_time_probertt_entered = us_cts;
3598 	segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
3599 		     rack->r_ctl.rc_pace_min_segs);
3600 	rack->in_probe_rtt = 1;
3601 	rack->measure_saw_probe_rtt = 1;
3602 	rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
3603 	rack->r_ctl.rc_time_probertt_starts = 0;
3604 	rack->r_ctl.rc_entry_gp_rtt = rack->r_ctl.rc_gp_srtt;
3605 	if (rack_probertt_use_min_rtt_entry)
3606 		rack_set_prtt_target(rack, segsiz, get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
3607 	else
3608 		rack_set_prtt_target(rack, segsiz, rack->r_ctl.rc_gp_srtt);
3609 	rack_log_rtt_shrinks(rack,  us_cts,  get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3610 			     __LINE__, RACK_RTTS_ENTERPROBE);
3611 }
3612 
3613 static void
3614 rack_exit_probertt(struct tcp_rack *rack, uint32_t us_cts)
3615 {
3616 	struct rack_sendmap *rsm;
3617 	uint32_t segsiz;
3618 
3619 	segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
3620 		     rack->r_ctl.rc_pace_min_segs);
3621 	rack->in_probe_rtt = 0;
3622 	if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
3623 	    SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
3624 		/*
3625 		 * Stop the goodput now, the idea here is
3626 		 * that future measurements with in_probe_rtt
3627 		 * won't register if they are not greater so
3628 		 * we want to get what info (if any) is available
3629 		 * now.
3630 		 */
3631 		rack_do_goodput_measurement(rack->rc_tp, rack,
3632 					    rack->rc_tp->snd_una, __LINE__,
3633 					    RACK_QUALITY_PROBERTT);
3634 	} else if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
3635 		/*
3636 		 * We don't have enough data to make a measurement.
3637 		 * So lets just stop and start here after exiting
3638 		 * probe-rtt. We probably are not interested in
3639 		 * the results anyway.
3640 		 */
3641 		rack->rc_tp->t_flags &= ~TF_GPUTINPROG;
3642 	}
3643 	/*
3644 	 * Measurements through the current snd_max are going
3645 	 * to be limited by the slower pacing rate.
3646 	 *
3647 	 * We need to mark these as app-limited so we
3648 	 * don't collapse the b/w.
3649 	 */
3650 	rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
3651 	if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
3652 		if (rack->r_ctl.rc_app_limited_cnt == 0)
3653 			rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
3654 		else {
3655 			/*
3656 			 * Go out to the end app limited and mark
3657 			 * this new one as next and move the end_appl up
3658 			 * to this guy.
3659 			 */
3660 			if (rack->r_ctl.rc_end_appl)
3661 				rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
3662 			rack->r_ctl.rc_end_appl = rsm;
3663 		}
3664 		rsm->r_flags |= RACK_APP_LIMITED;
3665 		rack->r_ctl.rc_app_limited_cnt++;
3666 	}
3667 	/*
3668 	 * Now, we need to examine our pacing rate multipliers.
3669 	 * If its under 100%, we need to kick it back up to
3670 	 * 100%. We also don't let it be over our "max" above
3671 	 * the actual rate i.e. 100% + rack_clamp_atexit_prtt.
3672 	 * Note setting clamp_atexit_prtt to 0 has the effect
3673 	 * of setting CA/SS to 100% always at exit (which is
3674 	 * the default behavior).
3675 	 */
3676 	if (rack_probertt_clear_is) {
3677 		rack->rc_gp_incr = 0;
3678 		rack->rc_gp_bwred = 0;
3679 		rack->rc_gp_timely_inc_cnt = 0;
3680 		rack->rc_gp_timely_dec_cnt = 0;
3681 	}
3682 	/* Do we do any clamping at exit? */
3683 	if (rack->rc_highly_buffered && rack_atexit_prtt_hbp) {
3684 		rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt_hbp;
3685 		rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt_hbp;
3686 	}
3687 	if ((rack->rc_highly_buffered == 0) && rack_atexit_prtt) {
3688 		rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt;
3689 		rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt;
3690 	}
3691 	/*
3692 	 * Lets set rtt_diff to 0, so that we will get a "boost"
3693 	 * after exiting.
3694 	 */
3695 	rack->r_ctl.rc_rtt_diff = 0;
3696 
3697 	/* Clear all flags so we start fresh */
3698 	rack->rc_tp->t_bytes_acked = 0;
3699 	rack->rc_tp->t_ccv.flags &= ~CCF_ABC_SENTAWND;
3700 	/*
3701 	 * If configured to, set the cwnd and ssthresh to
3702 	 * our targets.
3703 	 */
3704 	if (rack_probe_rtt_sets_cwnd) {
3705 		uint64_t ebdp;
3706 		uint32_t setto;
3707 
3708 		/* Set ssthresh so we get into CA once we hit our target */
3709 		if (rack_probertt_use_min_rtt_exit == 1) {
3710 			/* Set to min rtt */
3711 			rack_set_prtt_target(rack, segsiz,
3712 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
3713 		} else if (rack_probertt_use_min_rtt_exit == 2) {
3714 			/* Set to current gp rtt */
3715 			rack_set_prtt_target(rack, segsiz,
3716 					     rack->r_ctl.rc_gp_srtt);
3717 		} else if (rack_probertt_use_min_rtt_exit == 3) {
3718 			/* Set to entry gp rtt */
3719 			rack_set_prtt_target(rack, segsiz,
3720 					     rack->r_ctl.rc_entry_gp_rtt);
3721 		} else {
3722 			uint64_t sum;
3723 			uint32_t setval;
3724 
3725 			sum = rack->r_ctl.rc_entry_gp_rtt;
3726 			sum *= 10;
3727 			sum /= (uint64_t)(max(1, rack->r_ctl.rc_gp_srtt));
3728 			if (sum >= 20) {
3729 				/*
3730 				 * A highly buffered path needs
3731 				 * cwnd space for timely to work.
3732 				 * Lets set things up as if
3733 				 * we are heading back here again.
3734 				 */
3735 				setval = rack->r_ctl.rc_entry_gp_rtt;
3736 			} else if (sum >= 15) {
3737 				/*
3738 				 * Lets take the smaller of the
3739 				 * two since we are just somewhat
3740 				 * buffered.
3741 				 */
3742 				setval = rack->r_ctl.rc_gp_srtt;
3743 				if (setval > rack->r_ctl.rc_entry_gp_rtt)
3744 					setval = rack->r_ctl.rc_entry_gp_rtt;
3745 			} else {
3746 				/*
3747 				 * Here we are not highly buffered
3748 				 * and should pick the min we can to
3749 				 * keep from causing loss.
3750 				 */
3751 				setval = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3752 			}
3753 			rack_set_prtt_target(rack, segsiz,
3754 					     setval);
3755 		}
3756 		if (rack_probe_rtt_sets_cwnd > 1) {
3757 			/* There is a percentage here to boost */
3758 			ebdp = rack->r_ctl.rc_target_probertt_flight;
3759 			ebdp *= rack_probe_rtt_sets_cwnd;
3760 			ebdp /= 100;
3761 			setto = rack->r_ctl.rc_target_probertt_flight + ebdp;
3762 		} else
3763 			setto = rack->r_ctl.rc_target_probertt_flight;
3764 		rack->rc_tp->snd_cwnd = roundup(setto, segsiz);
3765 		if (rack->rc_tp->snd_cwnd < (segsiz * rack_timely_min_segs)) {
3766 			/* Enforce a min */
3767 			rack->rc_tp->snd_cwnd = segsiz * rack_timely_min_segs;
3768 		}
3769 		/* If we set in the cwnd also set the ssthresh point so we are in CA */
3770 		rack->rc_tp->snd_ssthresh = (rack->rc_tp->snd_cwnd - 1);
3771 	}
3772 	rack_log_rtt_shrinks(rack,  us_cts,
3773 			     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3774 			     __LINE__, RACK_RTTS_EXITPROBE);
3775 	/* Clear times last so log has all the info */
3776 	rack->r_ctl.rc_probertt_sndmax_atexit = rack->rc_tp->snd_max;
3777 	rack->r_ctl.rc_time_probertt_entered = us_cts;
3778 	rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
3779 	rack->r_ctl.rc_time_of_last_probertt = us_cts;
3780 }
3781 
3782 static void
3783 rack_check_probe_rtt(struct tcp_rack *rack, uint32_t us_cts)
3784 {
3785 	/* Check in on probe-rtt */
3786 	if (rack->rc_gp_filled == 0) {
3787 		/* We do not do p-rtt unless we have gp measurements */
3788 		return;
3789 	}
3790 	if (rack->in_probe_rtt) {
3791 		uint64_t no_overflow;
3792 		uint32_t endtime, must_stay;
3793 
3794 		if (rack->r_ctl.rc_went_idle_time &&
3795 		    ((us_cts - rack->r_ctl.rc_went_idle_time) > rack_min_probertt_hold)) {
3796 			/*
3797 			 * We went idle during prtt, just exit now.
3798 			 */
3799 			rack_exit_probertt(rack, us_cts);
3800 		} else if (rack_probe_rtt_safety_val &&
3801 		    TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered) &&
3802 		    ((us_cts - rack->r_ctl.rc_time_probertt_entered) > rack_probe_rtt_safety_val)) {
3803 			/*
3804 			 * Probe RTT safety value triggered!
3805 			 */
3806 			rack_log_rtt_shrinks(rack,  us_cts,
3807 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3808 					     __LINE__, RACK_RTTS_SAFETY);
3809 			rack_exit_probertt(rack, us_cts);
3810 		}
3811 		/* Calculate the max we will wait */
3812 		endtime = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_max_drain_wait);
3813 		if (rack->rc_highly_buffered)
3814 			endtime += (rack->r_ctl.rc_gp_srtt * rack_max_drain_hbp);
3815 		/* Calculate the min we must wait */
3816 		must_stay = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_must_drain);
3817 		if ((ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.rc_target_probertt_flight) &&
3818 		    TSTMP_LT(us_cts, endtime)) {
3819 			uint32_t calc;
3820 			/* Do we lower more? */
3821 no_exit:
3822 			if (TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered))
3823 				calc = us_cts - rack->r_ctl.rc_time_probertt_entered;
3824 			else
3825 				calc = 0;
3826 			calc /= max(rack->r_ctl.rc_gp_srtt, 1);
3827 			if (calc) {
3828 				/* Maybe */
3829 				calc *= rack_per_of_gp_probertt_reduce;
3830 				rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt - calc;
3831 				/* Limit it too */
3832 				if (rack->r_ctl.rack_per_of_gp_probertt < rack_per_of_gp_lowthresh)
3833 					rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_lowthresh;
3834 			}
3835 			/* We must reach target or the time set */
3836 			return;
3837 		}
3838 		if (rack->r_ctl.rc_time_probertt_starts == 0) {
3839 			if ((TSTMP_LT(us_cts, must_stay) &&
3840 			     rack->rc_highly_buffered) ||
3841 			     (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) >
3842 			      rack->r_ctl.rc_target_probertt_flight)) {
3843 				/* We are not past the must_stay time */
3844 				goto no_exit;
3845 			}
3846 			rack_log_rtt_shrinks(rack,  us_cts,
3847 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3848 					     __LINE__, RACK_RTTS_REACHTARGET);
3849 			rack->r_ctl.rc_time_probertt_starts = us_cts;
3850 			if (rack->r_ctl.rc_time_probertt_starts == 0)
3851 				rack->r_ctl.rc_time_probertt_starts = 1;
3852 			/* Restore back to our rate we want to pace at in prtt */
3853 			rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
3854 		}
3855 		/*
3856 		 * Setup our end time, some number of gp_srtts plus 200ms.
3857 		 */
3858 		no_overflow = ((uint64_t)rack->r_ctl.rc_gp_srtt *
3859 			       (uint64_t)rack_probertt_gpsrtt_cnt_mul);
3860 		if (rack_probertt_gpsrtt_cnt_div)
3861 			endtime = (uint32_t)(no_overflow / (uint64_t)rack_probertt_gpsrtt_cnt_div);
3862 		else
3863 			endtime = 0;
3864 		endtime += rack_min_probertt_hold;
3865 		endtime += rack->r_ctl.rc_time_probertt_starts;
3866 		if (TSTMP_GEQ(us_cts,  endtime)) {
3867 			/* yes, exit probertt */
3868 			rack_exit_probertt(rack, us_cts);
3869 		}
3870 
3871 	} else if ((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= rack_time_between_probertt) {
3872 		/* Go into probertt, its been too long since we went lower */
3873 		rack_enter_probertt(rack, us_cts);
3874 	}
3875 }
3876 
3877 static void
3878 rack_update_multiplier(struct tcp_rack *rack, int32_t timely_says, uint64_t last_bw_est,
3879 		       uint32_t rtt, int32_t rtt_diff)
3880 {
3881 	uint64_t cur_bw, up_bnd, low_bnd, subfr;
3882 	uint32_t losses;
3883 
3884 	if ((rack->rc_gp_dyn_mul == 0) ||
3885 	    (rack->use_fixed_rate) ||
3886 	    (rack->in_probe_rtt) ||
3887 	    (rack->rc_always_pace == 0)) {
3888 		/* No dynamic GP multiplier in play */
3889 		return;
3890 	}
3891 	losses = rack->r_ctl.rc_loss_count - rack->r_ctl.rc_loss_at_start;
3892 	cur_bw = rack_get_bw(rack);
3893 	/* Calculate our up and down range */
3894 	up_bnd = rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_up;
3895 	up_bnd /= 100;
3896 	up_bnd += rack->r_ctl.last_gp_comp_bw;
3897 
3898 	subfr = (uint64_t)rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_down;
3899 	subfr /= 100;
3900 	low_bnd = rack->r_ctl.last_gp_comp_bw - subfr;
3901 	if ((timely_says == 2) && (rack->r_ctl.rc_no_push_at_mrtt)) {
3902 		/*
3903 		 * This is the case where our RTT is above
3904 		 * the max target and we have been configured
3905 		 * to just do timely no bonus up stuff in that case.
3906 		 *
3907 		 * There are two configurations, set to 1, and we
3908 		 * just do timely if we are over our max. If its
3909 		 * set above 1 then we slam the multipliers down
3910 		 * to 100 and then decrement per timely.
3911 		 */
3912 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
3913 				__LINE__, 3);
3914 		if (rack->r_ctl.rc_no_push_at_mrtt > 1)
3915 			rack_validate_multipliers_at_or_below_100(rack);
3916 		rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
3917 	} else if ((last_bw_est < low_bnd) && !losses) {
3918 		/*
3919 		 * We are decreasing this is a bit complicated this
3920 		 * means we are loosing ground. This could be
3921 		 * because another flow entered and we are competing
3922 		 * for b/w with it. This will push the RTT up which
3923 		 * makes timely unusable unless we want to get shoved
3924 		 * into a corner and just be backed off (the age
3925 		 * old problem with delay based CC).
3926 		 *
3927 		 * On the other hand if it was a route change we
3928 		 * would like to stay somewhat contained and not
3929 		 * blow out the buffers.
3930 		 */
3931 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
3932 				__LINE__, 3);
3933 		rack->r_ctl.last_gp_comp_bw = cur_bw;
3934 		if (rack->rc_gp_bwred == 0) {
3935 			/* Go into reduction counting */
3936 			rack->rc_gp_bwred = 1;
3937 			rack->rc_gp_timely_dec_cnt = 0;
3938 		}
3939 		if ((rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) ||
3940 		    (timely_says == 0)) {
3941 			/*
3942 			 * Push another time with a faster pacing
3943 			 * to try to gain back (we include override to
3944 			 * get a full raise factor).
3945 			 */
3946 			if ((rack->rc_gp_saw_ca && rack->r_ctl.rack_per_of_gp_ca <= rack_down_raise_thresh) ||
3947 			    (rack->rc_gp_saw_ss && rack->r_ctl.rack_per_of_gp_ss <= rack_down_raise_thresh) ||
3948 			    (timely_says == 0) ||
3949 			    (rack_down_raise_thresh == 0)) {
3950 				/*
3951 				 * Do an override up in b/w if we were
3952 				 * below the threshold or if the threshold
3953 				 * is zero we always do the raise.
3954 				 */
3955 				rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 1);
3956 			} else {
3957 				/* Log it stays the same */
3958 				rack_log_timely(rack,  0, last_bw_est, low_bnd, 0,
3959 						__LINE__, 11);
3960 			}
3961 			rack->rc_gp_timely_dec_cnt++;
3962 			/* We are not incrementing really no-count */
3963 			rack->rc_gp_incr = 0;
3964 			rack->rc_gp_timely_inc_cnt = 0;
3965 		} else {
3966 			/*
3967 			 * Lets just use the RTT
3968 			 * information and give up
3969 			 * pushing.
3970 			 */
3971 			goto use_timely;
3972 		}
3973 	} else if ((timely_says != 2) &&
3974 		    !losses &&
3975 		    (last_bw_est > up_bnd)) {
3976 		/*
3977 		 * We are increasing b/w lets keep going, updating
3978 		 * our b/w and ignoring any timely input, unless
3979 		 * of course we are at our max raise (if there is one).
3980 		 */
3981 
3982 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
3983 				__LINE__, 3);
3984 		rack->r_ctl.last_gp_comp_bw = cur_bw;
3985 		if (rack->rc_gp_saw_ss &&
3986 		    rack_per_upper_bound_ss &&
3987 		     (rack->r_ctl.rack_per_of_gp_ss == rack_per_upper_bound_ss)) {
3988 			    /*
3989 			     * In cases where we can't go higher
3990 			     * we should just use timely.
3991 			     */
3992 			    goto use_timely;
3993 		}
3994 		if (rack->rc_gp_saw_ca &&
3995 		    rack_per_upper_bound_ca &&
3996 		    (rack->r_ctl.rack_per_of_gp_ca == rack_per_upper_bound_ca)) {
3997 			    /*
3998 			     * In cases where we can't go higher
3999 			     * we should just use timely.
4000 			     */
4001 			    goto use_timely;
4002 		}
4003 		rack->rc_gp_bwred = 0;
4004 		rack->rc_gp_timely_dec_cnt = 0;
4005 		/* You get a set number of pushes if timely is trying to reduce */
4006 		if ((rack->rc_gp_incr < rack_timely_max_push_rise) || (timely_says == 0)) {
4007 			rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4008 		} else {
4009 			/* Log it stays the same */
4010 			rack_log_timely(rack,  0, last_bw_est, up_bnd, 0,
4011 			    __LINE__, 12);
4012 		}
4013 		return;
4014 	} else {
4015 		/*
4016 		 * We are staying between the lower and upper range bounds
4017 		 * so use timely to decide.
4018 		 */
4019 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4020 				__LINE__, 3);
4021 use_timely:
4022 		if (timely_says) {
4023 			rack->rc_gp_incr = 0;
4024 			rack->rc_gp_timely_inc_cnt = 0;
4025 			if ((rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) &&
4026 			    !losses &&
4027 			    (last_bw_est < low_bnd)) {
4028 				/* We are loosing ground */
4029 				rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4030 				rack->rc_gp_timely_dec_cnt++;
4031 				/* We are not incrementing really no-count */
4032 				rack->rc_gp_incr = 0;
4033 				rack->rc_gp_timely_inc_cnt = 0;
4034 			} else
4035 				rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
4036 		} else {
4037 			rack->rc_gp_bwred = 0;
4038 			rack->rc_gp_timely_dec_cnt = 0;
4039 			rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4040 		}
4041 	}
4042 }
4043 
4044 static int32_t
4045 rack_make_timely_judgement(struct tcp_rack *rack, uint32_t rtt, int32_t rtt_diff, uint32_t prev_rtt)
4046 {
4047 	int32_t timely_says;
4048 	uint64_t log_mult, log_rtt_a_diff;
4049 
4050 	log_rtt_a_diff = rtt;
4051 	log_rtt_a_diff <<= 32;
4052 	log_rtt_a_diff |= (uint32_t)rtt_diff;
4053 	if (rtt >= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) *
4054 		    rack_gp_rtt_maxmul)) {
4055 		/* Reduce the b/w multiplier */
4056 		timely_says = 2;
4057 		log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
4058 		log_mult <<= 32;
4059 		log_mult |= prev_rtt;
4060 		rack_log_timely(rack,  timely_says, log_mult,
4061 				get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4062 				log_rtt_a_diff, __LINE__, 4);
4063 	} else if (rtt <= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
4064 			   ((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
4065 			    max(rack_gp_rtt_mindiv , 1)))) {
4066 		/* Increase the b/w multiplier */
4067 		log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
4068 			((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
4069 			 max(rack_gp_rtt_mindiv , 1));
4070 		log_mult <<= 32;
4071 		log_mult |= prev_rtt;
4072 		timely_says = 0;
4073 		rack_log_timely(rack,  timely_says, log_mult ,
4074 				get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4075 				log_rtt_a_diff, __LINE__, 5);
4076 	} else {
4077 		/*
4078 		 * Use a gradient to find it the timely gradient
4079 		 * is:
4080 		 * grad = rc_rtt_diff / min_rtt;
4081 		 *
4082 		 * anything below or equal to 0 will be
4083 		 * a increase indication. Anything above
4084 		 * zero is a decrease. Note we take care
4085 		 * of the actual gradient calculation
4086 		 * in the reduction (its not needed for
4087 		 * increase).
4088 		 */
4089 		log_mult = prev_rtt;
4090 		if (rtt_diff <= 0) {
4091 			/*
4092 			 * Rttdiff is less than zero, increase the
4093 			 * b/w multiplier (its 0 or negative)
4094 			 */
4095 			timely_says = 0;
4096 			rack_log_timely(rack,  timely_says, log_mult,
4097 					get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 6);
4098 		} else {
4099 			/* Reduce the b/w multiplier */
4100 			timely_says = 1;
4101 			rack_log_timely(rack,  timely_says, log_mult,
4102 					get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 7);
4103 		}
4104 	}
4105 	return (timely_says);
4106 }
4107 
4108 static void
4109 rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
4110 			    tcp_seq th_ack, int line, uint8_t quality)
4111 {
4112 	uint64_t tim, bytes_ps, ltim, stim, utim;
4113 	uint32_t segsiz, bytes, reqbytes, us_cts;
4114 	int32_t gput, new_rtt_diff, timely_says;
4115 	uint64_t  resid_bw, subpart = 0, addpart = 0, srtt;
4116 	int did_add = 0;
4117 
4118 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
4119 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
4120 	if (TSTMP_GEQ(us_cts, tp->gput_ts))
4121 		tim = us_cts - tp->gput_ts;
4122 	else
4123 		tim = 0;
4124 	if (rack->r_ctl.rc_gp_cumack_ts > rack->r_ctl.rc_gp_output_ts)
4125 		stim = rack->r_ctl.rc_gp_cumack_ts - rack->r_ctl.rc_gp_output_ts;
4126 	else
4127 		stim = 0;
4128 	/*
4129 	 * Use the larger of the send time or ack time. This prevents us
4130 	 * from being influenced by ack artifacts to come up with too
4131 	 * high of measurement. Note that since we are spanning over many more
4132 	 * bytes in most of our measurements hopefully that is less likely to
4133 	 * occur.
4134 	 */
4135 	if (tim > stim)
4136 		utim = max(tim, 1);
4137 	else
4138 		utim = max(stim, 1);
4139 	/* Lets get a msec time ltim too for the old stuff */
4140 	ltim = max(1, (utim / HPTS_USEC_IN_MSEC));
4141 	gput = (((uint64_t) (th_ack - tp->gput_seq)) << 3) / ltim;
4142 	reqbytes = min(rc_init_window(rack), (MIN_GP_WIN * segsiz));
4143 	if ((tim == 0) && (stim == 0)) {
4144 		/*
4145 		 * Invalid measurement time, maybe
4146 		 * all on one ack/one send?
4147 		 */
4148 		bytes = 0;
4149 		bytes_ps = 0;
4150 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4151 					   0, 0, 0, 10, __LINE__, NULL, quality);
4152 		goto skip_measurement;
4153 	}
4154 	if (rack->r_ctl.rc_gp_lowrtt == 0xffffffff) {
4155 		/* We never made a us_rtt measurement? */
4156 		bytes = 0;
4157 		bytes_ps = 0;
4158 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4159 					   0, 0, 0, 10, __LINE__, NULL, quality);
4160 		goto skip_measurement;
4161 	}
4162 	/*
4163 	 * Calculate the maximum possible b/w this connection
4164 	 * could have. We base our calculation on the lowest
4165 	 * rtt we have seen during the measurement and the
4166 	 * largest rwnd the client has given us in that time. This
4167 	 * forms a BDP that is the maximum that we could ever
4168 	 * get to the client. Anything larger is not valid.
4169 	 *
4170 	 * I originally had code here that rejected measurements
4171 	 * where the time was less than 1/2 the latest us_rtt.
4172 	 * But after thinking on that I realized its wrong since
4173 	 * say you had a 150Mbps or even 1Gbps link, and you
4174 	 * were a long way away.. example I am in Europe (100ms rtt)
4175 	 * talking to my 1Gbps link in S.C. Now measuring say 150,000
4176 	 * bytes my time would be 1.2ms, and yet my rtt would say
4177 	 * the measurement was invalid the time was < 50ms. The
4178 	 * same thing is true for 150Mb (8ms of time).
4179 	 *
4180 	 * A better way I realized is to look at what the maximum
4181 	 * the connection could possibly do. This is gated on
4182 	 * the lowest RTT we have seen and the highest rwnd.
4183 	 * We should in theory never exceed that, if we are
4184 	 * then something on the path is storing up packets
4185 	 * and then feeding them all at once to our endpoint
4186 	 * messing up our measurement.
4187 	 */
4188 	rack->r_ctl.last_max_bw = rack->r_ctl.rc_gp_high_rwnd;
4189 	rack->r_ctl.last_max_bw *= HPTS_USEC_IN_SEC;
4190 	rack->r_ctl.last_max_bw /= rack->r_ctl.rc_gp_lowrtt;
4191 	if (SEQ_LT(th_ack, tp->gput_seq)) {
4192 		/* No measurement can be made */
4193 		bytes = 0;
4194 		bytes_ps = 0;
4195 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4196 					   0, 0, 0, 10, __LINE__, NULL, quality);
4197 		goto skip_measurement;
4198 	} else
4199 		bytes = (th_ack - tp->gput_seq);
4200 	bytes_ps = (uint64_t)bytes;
4201 	/*
4202 	 * Don't measure a b/w for pacing unless we have gotten at least
4203 	 * an initial windows worth of data in this measurement interval.
4204 	 *
4205 	 * Small numbers of bytes get badly influenced by delayed ack and
4206 	 * other artifacts. Note we take the initial window or our
4207 	 * defined minimum GP (defaulting to 10 which hopefully is the
4208 	 * IW).
4209 	 */
4210 	if (rack->rc_gp_filled == 0) {
4211 		/*
4212 		 * The initial estimate is special. We
4213 		 * have blasted out an IW worth of packets
4214 		 * without a real valid ack ts results. We
4215 		 * then setup the app_limited_needs_set flag,
4216 		 * this should get the first ack in (probably 2
4217 		 * MSS worth) to be recorded as the timestamp.
4218 		 * We thus allow a smaller number of bytes i.e.
4219 		 * IW - 2MSS.
4220 		 */
4221 		reqbytes -= (2 * segsiz);
4222 		/* Also lets fill previous for our first measurement to be neutral */
4223 		rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
4224 	}
4225 	if ((bytes_ps < reqbytes) || rack->app_limited_needs_set) {
4226 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4227 					   rack->r_ctl.rc_app_limited_cnt,
4228 					   0, 0, 10, __LINE__, NULL, quality);
4229 		goto skip_measurement;
4230 	}
4231 	/*
4232 	 * We now need to calculate the Timely like status so
4233 	 * we can update (possibly) the b/w multipliers.
4234 	 */
4235 	new_rtt_diff = (int32_t)rack->r_ctl.rc_gp_srtt - (int32_t)rack->r_ctl.rc_prev_gp_srtt;
4236 	if (rack->rc_gp_filled == 0) {
4237 		/* No previous reading */
4238 		rack->r_ctl.rc_rtt_diff = new_rtt_diff;
4239 	} else {
4240 		if (rack->measure_saw_probe_rtt == 0) {
4241 			/*
4242 			 * We don't want a probertt to be counted
4243 			 * since it will be negative incorrectly. We
4244 			 * expect to be reducing the RTT when we
4245 			 * pace at a slower rate.
4246 			 */
4247 			rack->r_ctl.rc_rtt_diff -= (rack->r_ctl.rc_rtt_diff / 8);
4248 			rack->r_ctl.rc_rtt_diff += (new_rtt_diff / 8);
4249 		}
4250 	}
4251 	timely_says = rack_make_timely_judgement(rack,
4252 		rack->r_ctl.rc_gp_srtt,
4253 		rack->r_ctl.rc_rtt_diff,
4254 	        rack->r_ctl.rc_prev_gp_srtt
4255 		);
4256 	bytes_ps *= HPTS_USEC_IN_SEC;
4257 	bytes_ps /= utim;
4258 	if (bytes_ps > rack->r_ctl.last_max_bw) {
4259 		/*
4260 		 * Something is on path playing
4261 		 * since this b/w is not possible based
4262 		 * on our BDP (highest rwnd and lowest rtt
4263 		 * we saw in the measurement window).
4264 		 *
4265 		 * Another option here would be to
4266 		 * instead skip the measurement.
4267 		 */
4268 		rack_log_pacing_delay_calc(rack, bytes, reqbytes,
4269 					   bytes_ps, rack->r_ctl.last_max_bw, 0,
4270 					   11, __LINE__, NULL, quality);
4271 		bytes_ps = rack->r_ctl.last_max_bw;
4272 	}
4273 	/* We store gp for b/w in bytes per second */
4274 	if (rack->rc_gp_filled == 0) {
4275 		/* Initial measurement */
4276 		if (bytes_ps) {
4277 			rack->r_ctl.gp_bw = bytes_ps;
4278 			rack->rc_gp_filled = 1;
4279 			rack->r_ctl.num_measurements = 1;
4280 			rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
4281 		} else {
4282 			rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4283 						   rack->r_ctl.rc_app_limited_cnt,
4284 						   0, 0, 10, __LINE__, NULL, quality);
4285 		}
4286 		if (tcp_in_hpts(rack->rc_inp) &&
4287 		    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
4288 			/*
4289 			 * Ok we can't trust the pacer in this case
4290 			 * where we transition from un-paced to paced.
4291 			 * Or for that matter when the burst mitigation
4292 			 * was making a wild guess and got it wrong.
4293 			 * Stop the pacer and clear up all the aggregate
4294 			 * delays etc.
4295 			 */
4296 			tcp_hpts_remove(rack->rc_inp);
4297 			rack->r_ctl.rc_hpts_flags = 0;
4298 			rack->r_ctl.rc_last_output_to = 0;
4299 		}
4300 		did_add = 2;
4301 	} else if (rack->r_ctl.num_measurements < RACK_REQ_AVG) {
4302 		/* Still a small number run an average */
4303 		rack->r_ctl.gp_bw += bytes_ps;
4304 		addpart = rack->r_ctl.num_measurements;
4305 		rack->r_ctl.num_measurements++;
4306 		if (rack->r_ctl.num_measurements >= RACK_REQ_AVG) {
4307 			/* We have collected enough to move forward */
4308 			rack->r_ctl.gp_bw /= (uint64_t)rack->r_ctl.num_measurements;
4309 		}
4310 		did_add = 3;
4311 	} else {
4312 		/*
4313 		 * We want to take 1/wma of the goodput and add in to 7/8th
4314 		 * of the old value weighted by the srtt. So if your measurement
4315 		 * period is say 2 SRTT's long you would get 1/4 as the
4316 		 * value, if it was like 1/2 SRTT then you would get 1/16th.
4317 		 *
4318 		 * But we must be careful not to take too much i.e. if the
4319 		 * srtt is say 20ms and the measurement is taken over
4320 		 * 400ms our weight would be 400/20 i.e. 20. On the
4321 		 * other hand if we get a measurement over 1ms with a
4322 		 * 10ms rtt we only want to take a much smaller portion.
4323 		 */
4324 		if (rack->r_ctl.num_measurements < 0xff) {
4325 			rack->r_ctl.num_measurements++;
4326 		}
4327 		srtt = (uint64_t)tp->t_srtt;
4328 		if (srtt == 0) {
4329 			/*
4330 			 * Strange why did t_srtt go back to zero?
4331 			 */
4332 			if (rack->r_ctl.rc_rack_min_rtt)
4333 				srtt = rack->r_ctl.rc_rack_min_rtt;
4334 			else
4335 				srtt = HPTS_USEC_IN_MSEC;
4336 		}
4337 		/*
4338 		 * XXXrrs: Note for reviewers, in playing with
4339 		 * dynamic pacing I discovered this GP calculation
4340 		 * as done originally leads to some undesired results.
4341 		 * Basically you can get longer measurements contributing
4342 		 * too much to the WMA. Thus I changed it if you are doing
4343 		 * dynamic adjustments to only do the aportioned adjustment
4344 		 * if we have a very small (time wise) measurement. Longer
4345 		 * measurements just get there weight (defaulting to 1/8)
4346 		 * add to the WMA. We may want to think about changing
4347 		 * this to always do that for both sides i.e. dynamic
4348 		 * and non-dynamic... but considering lots of folks
4349 		 * were playing with this I did not want to change the
4350 		 * calculation per.se. without your thoughts.. Lawerence?
4351 		 * Peter??
4352 		 */
4353 		if (rack->rc_gp_dyn_mul == 0) {
4354 			subpart = rack->r_ctl.gp_bw * utim;
4355 			subpart /= (srtt * 8);
4356 			if (subpart < (rack->r_ctl.gp_bw / 2)) {
4357 				/*
4358 				 * The b/w update takes no more
4359 				 * away then 1/2 our running total
4360 				 * so factor it in.
4361 				 */
4362 				addpart = bytes_ps * utim;
4363 				addpart /= (srtt * 8);
4364 			} else {
4365 				/*
4366 				 * Don't allow a single measurement
4367 				 * to account for more than 1/2 of the
4368 				 * WMA. This could happen on a retransmission
4369 				 * where utim becomes huge compared to
4370 				 * srtt (multiple retransmissions when using
4371 				 * the sending rate which factors in all the
4372 				 * transmissions from the first one).
4373 				 */
4374 				subpart = rack->r_ctl.gp_bw / 2;
4375 				addpart = bytes_ps / 2;
4376 			}
4377 			resid_bw = rack->r_ctl.gp_bw - subpart;
4378 			rack->r_ctl.gp_bw = resid_bw + addpart;
4379 			did_add = 1;
4380 		} else {
4381 			if ((utim / srtt) <= 1) {
4382 				/*
4383 				 * The b/w update was over a small period
4384 				 * of time. The idea here is to prevent a small
4385 				 * measurement time period from counting
4386 				 * too much. So we scale it based on the
4387 				 * time so it attributes less than 1/rack_wma_divisor
4388 				 * of its measurement.
4389 				 */
4390 				subpart = rack->r_ctl.gp_bw * utim;
4391 				subpart /= (srtt * rack_wma_divisor);
4392 				addpart = bytes_ps * utim;
4393 				addpart /= (srtt * rack_wma_divisor);
4394 			} else {
4395 				/*
4396 				 * The scaled measurement was long
4397 				 * enough so lets just add in the
4398 				 * portion of the measurement i.e. 1/rack_wma_divisor
4399 				 */
4400 				subpart = rack->r_ctl.gp_bw / rack_wma_divisor;
4401 				addpart = bytes_ps / rack_wma_divisor;
4402 			}
4403 			if ((rack->measure_saw_probe_rtt == 0) ||
4404 		            (bytes_ps > rack->r_ctl.gp_bw)) {
4405 				/*
4406 				 * For probe-rtt we only add it in
4407 				 * if its larger, all others we just
4408 				 * add in.
4409 				 */
4410 				did_add = 1;
4411 				resid_bw = rack->r_ctl.gp_bw - subpart;
4412 				rack->r_ctl.gp_bw = resid_bw + addpart;
4413 			}
4414 		}
4415 	}
4416 	if ((rack->gp_ready == 0) &&
4417 	    (rack->r_ctl.num_measurements >= rack->r_ctl.req_measurements)) {
4418 		/* We have enough measurements now */
4419 		rack->gp_ready = 1;
4420 		rack_set_cc_pacing(rack);
4421 		if (rack->defer_options)
4422 			rack_apply_deferred_options(rack);
4423 	}
4424 	rack_log_pacing_delay_calc(rack, subpart, addpart, bytes_ps, stim,
4425 				   rack_get_bw(rack), 22, did_add, NULL, quality);
4426 	/* We do not update any multipliers if we are in or have seen a probe-rtt */
4427 	if ((rack->measure_saw_probe_rtt == 0) && rack->rc_gp_rtt_set)
4428 		rack_update_multiplier(rack, timely_says, bytes_ps,
4429 				       rack->r_ctl.rc_gp_srtt,
4430 				       rack->r_ctl.rc_rtt_diff);
4431 	rack_log_pacing_delay_calc(rack, bytes, tim, bytes_ps, stim,
4432 				   rack_get_bw(rack), 3, line, NULL, quality);
4433 	/* reset the gp srtt and setup the new prev */
4434 	rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
4435 	/* Record the lost count for the next measurement */
4436 	rack->r_ctl.rc_loss_at_start = rack->r_ctl.rc_loss_count;
4437 	/*
4438 	 * We restart our diffs based on the gpsrtt in the
4439 	 * measurement window.
4440 	 */
4441 	rack->rc_gp_rtt_set = 0;
4442 	rack->rc_gp_saw_rec = 0;
4443 	rack->rc_gp_saw_ca = 0;
4444 	rack->rc_gp_saw_ss = 0;
4445 	rack->rc_dragged_bottom = 0;
4446 skip_measurement:
4447 
4448 #ifdef STATS
4449 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_GPUT,
4450 				 gput);
4451 	/*
4452 	 * XXXLAS: This is a temporary hack, and should be
4453 	 * chained off VOI_TCP_GPUT when stats(9) grows an
4454 	 * API to deal with chained VOIs.
4455 	 */
4456 	if (tp->t_stats_gput_prev > 0)
4457 		stats_voi_update_abs_s32(tp->t_stats,
4458 					 VOI_TCP_GPUT_ND,
4459 					 ((gput - tp->t_stats_gput_prev) * 100) /
4460 					 tp->t_stats_gput_prev);
4461 #endif
4462 	tp->t_flags &= ~TF_GPUTINPROG;
4463 	tp->t_stats_gput_prev = gput;
4464 	/*
4465 	 * Now are we app limited now and there is space from where we
4466 	 * were to where we want to go?
4467 	 *
4468 	 * We don't do the other case i.e. non-applimited here since
4469 	 * the next send will trigger us picking up the missing data.
4470 	 */
4471 	if (rack->r_ctl.rc_first_appl &&
4472 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
4473 	    rack->r_ctl.rc_app_limited_cnt &&
4474 	    (SEQ_GT(rack->r_ctl.rc_first_appl->r_start, th_ack)) &&
4475 	    ((rack->r_ctl.rc_first_appl->r_end - th_ack) >
4476 	     max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
4477 		/*
4478 		 * Yep there is enough outstanding to make a measurement here.
4479 		 */
4480 		struct rack_sendmap *rsm, fe;
4481 
4482 		rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
4483 		rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
4484 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
4485 		rack->app_limited_needs_set = 0;
4486 		tp->gput_seq = th_ack;
4487 		if (rack->in_probe_rtt)
4488 			rack->measure_saw_probe_rtt = 1;
4489 		else if ((rack->measure_saw_probe_rtt) &&
4490 			 (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
4491 			rack->measure_saw_probe_rtt = 0;
4492 		if ((rack->r_ctl.rc_first_appl->r_end - th_ack) >= rack_get_measure_window(tp, rack)) {
4493 			/* There is a full window to gain info from */
4494 			tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
4495 		} else {
4496 			/* We can only measure up to the applimited point */
4497 			tp->gput_ack = tp->gput_seq + (rack->r_ctl.rc_first_appl->r_end - th_ack);
4498 			if ((tp->gput_ack - tp->gput_seq) < (MIN_GP_WIN * segsiz)) {
4499 				/*
4500 				 * We don't have enough to make a measurement.
4501 				 */
4502 				tp->t_flags &= ~TF_GPUTINPROG;
4503 				rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
4504 							   0, 0, 0, 6, __LINE__, NULL, quality);
4505 				return;
4506 			}
4507 		}
4508 		if (tp->t_state >= TCPS_FIN_WAIT_1) {
4509 			/*
4510 			 * We will get no more data into the SB
4511 			 * this means we need to have the data available
4512 			 * before we start a measurement.
4513 			 */
4514 			if (sbavail(&tptosocket(tp)->so_snd) < (tp->gput_ack - tp->gput_seq)) {
4515 				/* Nope not enough data. */
4516 				return;
4517 			}
4518 		}
4519 		tp->t_flags |= TF_GPUTINPROG;
4520 		/*
4521 		 * Now we need to find the timestamp of the send at tp->gput_seq
4522 		 * for the send based measurement.
4523 		 */
4524 		fe.r_start = tp->gput_seq;
4525 		rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
4526 		if (rsm) {
4527 			/* Ok send-based limit is set */
4528 			if (SEQ_LT(rsm->r_start, tp->gput_seq)) {
4529 				/*
4530 				 * Move back to include the earlier part
4531 				 * so our ack time lines up right (this may
4532 				 * make an overlapping measurement but thats
4533 				 * ok).
4534 				 */
4535 				tp->gput_seq = rsm->r_start;
4536 			}
4537 			if (rsm->r_flags & RACK_ACKED)
4538 				tp->gput_ts = (uint32_t)rsm->r_ack_arrival;
4539 			else
4540 				rack->app_limited_needs_set = 1;
4541 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
4542 		} else {
4543 			/*
4544 			 * If we don't find the rsm due to some
4545 			 * send-limit set the current time, which
4546 			 * basically disables the send-limit.
4547 			 */
4548 			struct timeval tv;
4549 
4550 			microuptime(&tv);
4551 			rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
4552 		}
4553 		rack_log_pacing_delay_calc(rack,
4554 					   tp->gput_seq,
4555 					   tp->gput_ack,
4556 					   (uint64_t)rsm,
4557 					   tp->gput_ts,
4558 					   rack->r_ctl.rc_app_limited_cnt,
4559 					   9,
4560 					   __LINE__, NULL, quality);
4561 	}
4562 }
4563 
4564 /*
4565  * CC wrapper hook functions
4566  */
4567 static void
4568 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack, uint32_t th_ack, uint16_t nsegs,
4569     uint16_t type, int32_t recovery)
4570 {
4571 	uint32_t prior_cwnd, acked;
4572 	struct tcp_log_buffer *lgb = NULL;
4573 	uint8_t labc_to_use, quality;
4574 
4575 	INP_WLOCK_ASSERT(tptoinpcb(tp));
4576 	tp->t_ccv.nsegs = nsegs;
4577 	acked = tp->t_ccv.bytes_this_ack = (th_ack - tp->snd_una);
4578 	if ((recovery) && (rack->r_ctl.rc_early_recovery_segs)) {
4579 		uint32_t max;
4580 
4581 		max = rack->r_ctl.rc_early_recovery_segs * ctf_fixed_maxseg(tp);
4582 		if (tp->t_ccv.bytes_this_ack > max) {
4583 			tp->t_ccv.bytes_this_ack = max;
4584 		}
4585 	}
4586 #ifdef STATS
4587 	stats_voi_update_abs_s32(tp->t_stats, VOI_TCP_CALCFRWINDIFF,
4588 	    ((int32_t)rack->r_ctl.cwnd_to_use) - tp->snd_wnd);
4589 #endif
4590 	quality = RACK_QUALITY_NONE;
4591 	if ((tp->t_flags & TF_GPUTINPROG) &&
4592 	    rack_enough_for_measurement(tp, rack, th_ack, &quality)) {
4593 		/* Measure the Goodput */
4594 		rack_do_goodput_measurement(tp, rack, th_ack, __LINE__, quality);
4595 #ifdef NETFLIX_PEAKRATE
4596 		if ((type == CC_ACK) &&
4597 		    (tp->t_maxpeakrate)) {
4598 			/*
4599 			 * We update t_peakrate_thr. This gives us roughly
4600 			 * one update per round trip time. Note
4601 			 * it will only be used if pace_always is off i.e
4602 			 * we don't do this for paced flows.
4603 			 */
4604 			rack_update_peakrate_thr(tp);
4605 		}
4606 #endif
4607 	}
4608 	/* Which way our we limited, if not cwnd limited no advance in CA */
4609 	if (tp->snd_cwnd <= tp->snd_wnd)
4610 		tp->t_ccv.flags |= CCF_CWND_LIMITED;
4611 	else
4612 		tp->t_ccv.flags &= ~CCF_CWND_LIMITED;
4613 	if (tp->snd_cwnd > tp->snd_ssthresh) {
4614 		tp->t_bytes_acked += min(tp->t_ccv.bytes_this_ack,
4615 			 nsegs * V_tcp_abc_l_var * ctf_fixed_maxseg(tp));
4616 		/* For the setting of a window past use the actual scwnd we are using */
4617 		if (tp->t_bytes_acked >= rack->r_ctl.cwnd_to_use) {
4618 			tp->t_bytes_acked -= rack->r_ctl.cwnd_to_use;
4619 			tp->t_ccv.flags |= CCF_ABC_SENTAWND;
4620 		}
4621 	} else {
4622 		tp->t_ccv.flags &= ~CCF_ABC_SENTAWND;
4623 		tp->t_bytes_acked = 0;
4624 	}
4625 	prior_cwnd = tp->snd_cwnd;
4626 	if ((recovery == 0) || (rack_max_abc_post_recovery == 0) || rack->r_use_labc_for_rec ||
4627 	    (rack_client_low_buf && (rack->client_bufferlvl < rack_client_low_buf)))
4628 		labc_to_use = rack->rc_labc;
4629 	else
4630 		labc_to_use = rack_max_abc_post_recovery;
4631 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
4632 		union tcp_log_stackspecific log;
4633 		struct timeval tv;
4634 
4635 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
4636 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
4637 		log.u_bbr.flex1 = th_ack;
4638 		log.u_bbr.flex2 = tp->t_ccv.flags;
4639 		log.u_bbr.flex3 = tp->t_ccv.bytes_this_ack;
4640 		log.u_bbr.flex4 = tp->t_ccv.nsegs;
4641 		log.u_bbr.flex5 = labc_to_use;
4642 		log.u_bbr.flex6 = prior_cwnd;
4643 		log.u_bbr.flex7 = V_tcp_do_newsack;
4644 		log.u_bbr.flex8 = 1;
4645 		lgb = tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
4646 				     0, &log, false, NULL, NULL, 0, &tv);
4647 	}
4648 	if (CC_ALGO(tp)->ack_received != NULL) {
4649 		/* XXXLAS: Find a way to live without this */
4650 		tp->t_ccv.curack = th_ack;
4651 		tp->t_ccv.labc = labc_to_use;
4652 		tp->t_ccv.flags |= CCF_USE_LOCAL_ABC;
4653 		CC_ALGO(tp)->ack_received(&tp->t_ccv, type);
4654 	}
4655 	if (lgb) {
4656 		lgb->tlb_stackinfo.u_bbr.flex6 = tp->snd_cwnd;
4657 	}
4658 	if (rack->r_must_retran) {
4659 		if (SEQ_GEQ(th_ack, rack->r_ctl.rc_snd_max_at_rto)) {
4660 			/*
4661 			 * We now are beyond the rxt point so lets disable
4662 			 * the flag.
4663 			 */
4664 			rack->r_ctl.rc_out_at_rto = 0;
4665 			rack->r_must_retran = 0;
4666 		} else if ((prior_cwnd + ctf_fixed_maxseg(tp)) <= tp->snd_cwnd) {
4667 			/*
4668 			 * Only decrement the rc_out_at_rto if the cwnd advances
4669 			 * at least a whole segment. Otherwise next time the peer
4670 			 * acks, we won't be able to send this generaly happens
4671 			 * when we are in Congestion Avoidance.
4672 			 */
4673 			if (acked <= rack->r_ctl.rc_out_at_rto){
4674 				rack->r_ctl.rc_out_at_rto -= acked;
4675 			} else {
4676 				rack->r_ctl.rc_out_at_rto = 0;
4677 			}
4678 		}
4679 	}
4680 #ifdef STATS
4681 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_LCWIN, rack->r_ctl.cwnd_to_use);
4682 #endif
4683 	if (rack->r_ctl.rc_rack_largest_cwnd < rack->r_ctl.cwnd_to_use) {
4684 		rack->r_ctl.rc_rack_largest_cwnd = rack->r_ctl.cwnd_to_use;
4685 	}
4686 #ifdef NETFLIX_PEAKRATE
4687 	/* we enforce max peak rate if it is set and we are not pacing */
4688 	if ((rack->rc_always_pace == 0) &&
4689 	    tp->t_peakrate_thr &&
4690 	    (tp->snd_cwnd > tp->t_peakrate_thr)) {
4691 		tp->snd_cwnd = tp->t_peakrate_thr;
4692 	}
4693 #endif
4694 }
4695 
4696 static void
4697 tcp_rack_partialack(struct tcpcb *tp)
4698 {
4699 	struct tcp_rack *rack;
4700 
4701 	rack = (struct tcp_rack *)tp->t_fb_ptr;
4702 	INP_WLOCK_ASSERT(tptoinpcb(tp));
4703 	/*
4704 	 * If we are doing PRR and have enough
4705 	 * room to send <or> we are pacing and prr
4706 	 * is disabled we will want to see if we
4707 	 * can send data (by setting r_wanted_output to
4708 	 * true).
4709 	 */
4710 	if ((rack->r_ctl.rc_prr_sndcnt > 0) ||
4711 	    rack->rack_no_prr)
4712 		rack->r_wanted_output = 1;
4713 }
4714 
4715 static void
4716 rack_post_recovery(struct tcpcb *tp, uint32_t th_ack)
4717 {
4718 	struct tcp_rack *rack;
4719 	uint32_t orig_cwnd;
4720 
4721 	orig_cwnd = tp->snd_cwnd;
4722 	INP_WLOCK_ASSERT(tptoinpcb(tp));
4723 	rack = (struct tcp_rack *)tp->t_fb_ptr;
4724 	/* only alert CC if we alerted when we entered */
4725 	if (CC_ALGO(tp)->post_recovery != NULL) {
4726 		tp->t_ccv.curack = th_ack;
4727 		CC_ALGO(tp)->post_recovery(&tp->t_ccv);
4728 		if (tp->snd_cwnd < tp->snd_ssthresh) {
4729 			/*
4730 			 * Rack has burst control and pacing
4731 			 * so lets not set this any lower than
4732 			 * snd_ssthresh per RFC-6582 (option 2).
4733 			 */
4734 			tp->snd_cwnd = tp->snd_ssthresh;
4735 		}
4736 	}
4737 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
4738 		union tcp_log_stackspecific log;
4739 		struct timeval tv;
4740 
4741 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
4742 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
4743 		log.u_bbr.flex1 = th_ack;
4744 		log.u_bbr.flex2 = tp->t_ccv.flags;
4745 		log.u_bbr.flex3 = tp->t_ccv.bytes_this_ack;
4746 		log.u_bbr.flex4 = tp->t_ccv.nsegs;
4747 		log.u_bbr.flex5 = V_tcp_abc_l_var;
4748 		log.u_bbr.flex6 = orig_cwnd;
4749 		log.u_bbr.flex7 = V_tcp_do_newsack;
4750 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
4751 		log.u_bbr.flex8 = 2;
4752 		tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
4753 			       0, &log, false, NULL, NULL, 0, &tv);
4754 	}
4755 	if ((rack->rack_no_prr == 0) &&
4756 	    (rack->no_prr_addback == 0) &&
4757 	    (rack->r_ctl.rc_prr_sndcnt > 0)) {
4758 		/*
4759 		 * Suck the next prr cnt back into cwnd, but
4760 		 * only do that if we are not application limited.
4761 		 */
4762 		if (ctf_outstanding(tp) <= sbavail(&tptosocket(tp)->so_snd)) {
4763 			/*
4764 			 * We are allowed to add back to the cwnd the amount we did
4765 			 * not get out if:
4766 			 * a) no_prr_addback is off.
4767 			 * b) we are not app limited
4768 			 * c) we are doing prr
4769 			 * <and>
4770 			 * d) it is bounded by rack_prr_addbackmax (if addback is 0, then none).
4771 			 */
4772 			tp->snd_cwnd += min((ctf_fixed_maxseg(tp) * rack_prr_addbackmax),
4773 					    rack->r_ctl.rc_prr_sndcnt);
4774 		}
4775 		rack->r_ctl.rc_prr_sndcnt = 0;
4776 		rack_log_to_prr(rack, 1, 0, __LINE__);
4777 	}
4778 	rack_log_to_prr(rack, 14, orig_cwnd, __LINE__);
4779 	tp->snd_recover = tp->snd_una;
4780 	if (rack->r_ctl.dsack_persist) {
4781 		rack->r_ctl.dsack_persist--;
4782 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
4783 			rack->r_ctl.num_dsack = 0;
4784 		}
4785 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
4786 	}
4787 	EXIT_RECOVERY(tp->t_flags);
4788 }
4789 
4790 static void
4791 rack_cong_signal(struct tcpcb *tp, uint32_t type, uint32_t ack, int line)
4792 {
4793 	struct tcp_rack *rack;
4794 	uint32_t ssthresh_enter, cwnd_enter, in_rec_at_entry, orig_cwnd;
4795 
4796 	INP_WLOCK_ASSERT(tptoinpcb(tp));
4797 #ifdef STATS
4798 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_CSIG, type);
4799 #endif
4800 	if (IN_RECOVERY(tp->t_flags) == 0) {
4801 		in_rec_at_entry = 0;
4802 		ssthresh_enter = tp->snd_ssthresh;
4803 		cwnd_enter = tp->snd_cwnd;
4804 	} else
4805 		in_rec_at_entry = 1;
4806 	rack = (struct tcp_rack *)tp->t_fb_ptr;
4807 	switch (type) {
4808 	case CC_NDUPACK:
4809 		tp->t_flags &= ~TF_WASFRECOVERY;
4810 		tp->t_flags &= ~TF_WASCRECOVERY;
4811 		if (!IN_FASTRECOVERY(tp->t_flags)) {
4812 			rack->r_ctl.rc_prr_delivered = 0;
4813 			rack->r_ctl.rc_prr_out = 0;
4814 			if (rack->rack_no_prr == 0) {
4815 				rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
4816 				rack_log_to_prr(rack, 2, in_rec_at_entry, line);
4817 			}
4818 			rack->r_ctl.rc_prr_recovery_fs = tp->snd_max - tp->snd_una;
4819 			tp->snd_recover = tp->snd_max;
4820 			if (tp->t_flags2 & TF2_ECN_PERMIT)
4821 				tp->t_flags2 |= TF2_ECN_SND_CWR;
4822 		}
4823 		break;
4824 	case CC_ECN:
4825 		if (!IN_CONGRECOVERY(tp->t_flags) ||
4826 		    /*
4827 		     * Allow ECN reaction on ACK to CWR, if
4828 		     * that data segment was also CE marked.
4829 		     */
4830 		    SEQ_GEQ(ack, tp->snd_recover)) {
4831 			EXIT_CONGRECOVERY(tp->t_flags);
4832 			KMOD_TCPSTAT_INC(tcps_ecn_rcwnd);
4833 			tp->snd_recover = tp->snd_max + 1;
4834 			if (tp->t_flags2 & TF2_ECN_PERMIT)
4835 				tp->t_flags2 |= TF2_ECN_SND_CWR;
4836 		}
4837 		break;
4838 	case CC_RTO:
4839 		tp->t_dupacks = 0;
4840 		tp->t_bytes_acked = 0;
4841 		EXIT_RECOVERY(tp->t_flags);
4842 		tp->snd_ssthresh = max(2, min(tp->snd_wnd, rack->r_ctl.cwnd_to_use) / 2 /
4843 		    ctf_fixed_maxseg(tp)) * ctf_fixed_maxseg(tp);
4844 		orig_cwnd = tp->snd_cwnd;
4845 		tp->snd_cwnd = ctf_fixed_maxseg(tp);
4846 		rack_log_to_prr(rack, 16, orig_cwnd, line);
4847 		if (tp->t_flags2 & TF2_ECN_PERMIT)
4848 			tp->t_flags2 |= TF2_ECN_SND_CWR;
4849 		break;
4850 	case CC_RTO_ERR:
4851 		KMOD_TCPSTAT_INC(tcps_sndrexmitbad);
4852 		/* RTO was unnecessary, so reset everything. */
4853 		tp->snd_cwnd = tp->snd_cwnd_prev;
4854 		tp->snd_ssthresh = tp->snd_ssthresh_prev;
4855 		tp->snd_recover = tp->snd_recover_prev;
4856 		if (tp->t_flags & TF_WASFRECOVERY) {
4857 			ENTER_FASTRECOVERY(tp->t_flags);
4858 			tp->t_flags &= ~TF_WASFRECOVERY;
4859 		}
4860 		if (tp->t_flags & TF_WASCRECOVERY) {
4861 			ENTER_CONGRECOVERY(tp->t_flags);
4862 			tp->t_flags &= ~TF_WASCRECOVERY;
4863 		}
4864 		tp->snd_nxt = tp->snd_max;
4865 		tp->t_badrxtwin = 0;
4866 		break;
4867 	}
4868 	if ((CC_ALGO(tp)->cong_signal != NULL)  &&
4869 	    (type != CC_RTO)){
4870 		tp->t_ccv.curack = ack;
4871 		CC_ALGO(tp)->cong_signal(&tp->t_ccv, type);
4872 	}
4873 	if ((in_rec_at_entry == 0) && IN_RECOVERY(tp->t_flags)) {
4874 		rack_log_to_prr(rack, 15, cwnd_enter, line);
4875 		rack->r_ctl.dsack_byte_cnt = 0;
4876 		rack->r_ctl.retran_during_recovery = 0;
4877 		rack->r_ctl.rc_cwnd_at_erec = cwnd_enter;
4878 		rack->r_ctl.rc_ssthresh_at_erec = ssthresh_enter;
4879 		rack->r_ent_rec_ns = 1;
4880 	}
4881 }
4882 
4883 static inline void
4884 rack_cc_after_idle(struct tcp_rack *rack, struct tcpcb *tp)
4885 {
4886 	uint32_t i_cwnd;
4887 
4888 	INP_WLOCK_ASSERT(tptoinpcb(tp));
4889 
4890 #ifdef NETFLIX_STATS
4891 	KMOD_TCPSTAT_INC(tcps_idle_restarts);
4892 	if (tp->t_state == TCPS_ESTABLISHED)
4893 		KMOD_TCPSTAT_INC(tcps_idle_estrestarts);
4894 #endif
4895 	if (CC_ALGO(tp)->after_idle != NULL)
4896 		CC_ALGO(tp)->after_idle(&tp->t_ccv);
4897 
4898 	if (tp->snd_cwnd == 1)
4899 		i_cwnd = tp->t_maxseg;		/* SYN(-ACK) lost */
4900 	else
4901 		i_cwnd = rc_init_window(rack);
4902 
4903 	/*
4904 	 * Being idle is no different than the initial window. If the cc
4905 	 * clamps it down below the initial window raise it to the initial
4906 	 * window.
4907 	 */
4908 	if (tp->snd_cwnd < i_cwnd) {
4909 		tp->snd_cwnd = i_cwnd;
4910 	}
4911 }
4912 
4913 /*
4914  * Indicate whether this ack should be delayed.  We can delay the ack if
4915  * following conditions are met:
4916  *	- There is no delayed ack timer in progress.
4917  *	- Our last ack wasn't a 0-sized window. We never want to delay
4918  *	  the ack that opens up a 0-sized window.
4919  *	- LRO wasn't used for this segment. We make sure by checking that the
4920  *	  segment size is not larger than the MSS.
4921  *	- Delayed acks are enabled or this is a half-synchronized T/TCP
4922  *	  connection.
4923  */
4924 #define DELAY_ACK(tp, tlen)			 \
4925 	(((tp->t_flags & TF_RXWIN0SENT) == 0) && \
4926 	((tp->t_flags & TF_DELACK) == 0) &&	 \
4927 	(tlen <= tp->t_maxseg) &&		 \
4928 	(tp->t_delayed_ack || (tp->t_flags & TF_NEEDSYN)))
4929 
4930 static struct rack_sendmap *
4931 rack_find_lowest_rsm(struct tcp_rack *rack)
4932 {
4933 	struct rack_sendmap *rsm;
4934 
4935 	/*
4936 	 * Walk the time-order transmitted list looking for an rsm that is
4937 	 * not acked. This will be the one that was sent the longest time
4938 	 * ago that is still outstanding.
4939 	 */
4940 	TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
4941 		if (rsm->r_flags & RACK_ACKED) {
4942 			continue;
4943 		}
4944 		goto finish;
4945 	}
4946 finish:
4947 	return (rsm);
4948 }
4949 
4950 static struct rack_sendmap *
4951 rack_find_high_nonack(struct tcp_rack *rack, struct rack_sendmap *rsm)
4952 {
4953 	struct rack_sendmap *prsm;
4954 
4955 	/*
4956 	 * Walk the sequence order list backward until we hit and arrive at
4957 	 * the highest seq not acked. In theory when this is called it
4958 	 * should be the last segment (which it was not).
4959 	 */
4960 	prsm = rsm;
4961 	RB_FOREACH_REVERSE_FROM(prsm, rack_rb_tree_head, rsm) {
4962 		if (prsm->r_flags & (RACK_ACKED | RACK_HAS_FIN)) {
4963 			continue;
4964 		}
4965 		return (prsm);
4966 	}
4967 	return (NULL);
4968 }
4969 
4970 static uint32_t
4971 rack_calc_thresh_rack(struct tcp_rack *rack, uint32_t srtt, uint32_t cts)
4972 {
4973 	int32_t lro;
4974 	uint32_t thresh;
4975 
4976 	/*
4977 	 * lro is the flag we use to determine if we have seen reordering.
4978 	 * If it gets set we have seen reordering. The reorder logic either
4979 	 * works in one of two ways:
4980 	 *
4981 	 * If reorder-fade is configured, then we track the last time we saw
4982 	 * re-ordering occur. If we reach the point where enough time as
4983 	 * passed we no longer consider reordering has occuring.
4984 	 *
4985 	 * Or if reorder-face is 0, then once we see reordering we consider
4986 	 * the connection to alway be subject to reordering and just set lro
4987 	 * to 1.
4988 	 *
4989 	 * In the end if lro is non-zero we add the extra time for
4990 	 * reordering in.
4991 	 */
4992 	if (srtt == 0)
4993 		srtt = 1;
4994 	if (rack->r_ctl.rc_reorder_ts) {
4995 		if (rack->r_ctl.rc_reorder_fade) {
4996 			if (SEQ_GEQ(cts, rack->r_ctl.rc_reorder_ts)) {
4997 				lro = cts - rack->r_ctl.rc_reorder_ts;
4998 				if (lro == 0) {
4999 					/*
5000 					 * No time as passed since the last
5001 					 * reorder, mark it as reordering.
5002 					 */
5003 					lro = 1;
5004 				}
5005 			} else {
5006 				/* Negative time? */
5007 				lro = 0;
5008 			}
5009 			if (lro > rack->r_ctl.rc_reorder_fade) {
5010 				/* Turn off reordering seen too */
5011 				rack->r_ctl.rc_reorder_ts = 0;
5012 				lro = 0;
5013 			}
5014 		} else {
5015 			/* Reodering does not fade */
5016 			lro = 1;
5017 		}
5018 	} else {
5019 		lro = 0;
5020 	}
5021 	if (rack->rc_rack_tmr_std_based == 0) {
5022 		thresh = srtt + rack->r_ctl.rc_pkt_delay;
5023 	} else {
5024 		/* Standards based pkt-delay is 1/4 srtt */
5025 		thresh = srtt +  (srtt >> 2);
5026 	}
5027 	if (lro && (rack->rc_rack_tmr_std_based == 0)) {
5028 		/* It must be set, if not you get 1/4 rtt */
5029 		if (rack->r_ctl.rc_reorder_shift)
5030 			thresh += (srtt >> rack->r_ctl.rc_reorder_shift);
5031 		else
5032 			thresh += (srtt >> 2);
5033 	}
5034 	if (rack->rc_rack_use_dsack &&
5035 	    lro &&
5036 	    (rack->r_ctl.num_dsack > 0)) {
5037 		/*
5038 		 * We only increase the reordering window if we
5039 		 * have seen reordering <and> we have a DSACK count.
5040 		 */
5041 		thresh += rack->r_ctl.num_dsack * (srtt >> 2);
5042 		rack_log_dsack_event(rack, 4, __LINE__, srtt, thresh);
5043 	}
5044 	/* SRTT * 2 is the ceiling */
5045 	if (thresh > (srtt * 2)) {
5046 		thresh = srtt * 2;
5047 	}
5048 	/* And we don't want it above the RTO max either */
5049 	if (thresh > rack_rto_max) {
5050 		thresh = rack_rto_max;
5051 	}
5052 	rack_log_dsack_event(rack, 6, __LINE__, srtt, thresh);
5053 	return (thresh);
5054 }
5055 
5056 static uint32_t
5057 rack_calc_thresh_tlp(struct tcpcb *tp, struct tcp_rack *rack,
5058 		     struct rack_sendmap *rsm, uint32_t srtt)
5059 {
5060 	struct rack_sendmap *prsm;
5061 	uint32_t thresh, len;
5062 	int segsiz;
5063 
5064 	if (srtt == 0)
5065 		srtt = 1;
5066 	if (rack->r_ctl.rc_tlp_threshold)
5067 		thresh = srtt + (srtt / rack->r_ctl.rc_tlp_threshold);
5068 	else
5069 		thresh = (srtt * 2);
5070 
5071 	/* Get the previous sent packet, if any */
5072 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
5073 	len = rsm->r_end - rsm->r_start;
5074 	if (rack->rack_tlp_threshold_use == TLP_USE_ID) {
5075 		/* Exactly like the ID */
5076 		if (((tp->snd_max - tp->snd_una) - rack->r_ctl.rc_sacked + rack->r_ctl.rc_holes_rxt) <= segsiz) {
5077 			uint32_t alt_thresh;
5078 			/*
5079 			 * Compensate for delayed-ack with the d-ack time.
5080 			 */
5081 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5082 			if (alt_thresh > thresh)
5083 				thresh = alt_thresh;
5084 		}
5085 	} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_ONE) {
5086 		/* 2.1 behavior */
5087 		prsm = TAILQ_PREV(rsm, rack_head, r_tnext);
5088 		if (prsm && (len <= segsiz)) {
5089 			/*
5090 			 * Two packets outstanding, thresh should be (2*srtt) +
5091 			 * possible inter-packet delay (if any).
5092 			 */
5093 			uint32_t inter_gap = 0;
5094 			int idx, nidx;
5095 
5096 			idx = rsm->r_rtr_cnt - 1;
5097 			nidx = prsm->r_rtr_cnt - 1;
5098 			if (rsm->r_tim_lastsent[nidx] >= prsm->r_tim_lastsent[idx]) {
5099 				/* Yes it was sent later (or at the same time) */
5100 				inter_gap = rsm->r_tim_lastsent[idx] - prsm->r_tim_lastsent[nidx];
5101 			}
5102 			thresh += inter_gap;
5103 		} else if (len <= segsiz) {
5104 			/*
5105 			 * Possibly compensate for delayed-ack.
5106 			 */
5107 			uint32_t alt_thresh;
5108 
5109 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5110 			if (alt_thresh > thresh)
5111 				thresh = alt_thresh;
5112 		}
5113 	} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_TWO) {
5114 		/* 2.2 behavior */
5115 		if (len <= segsiz) {
5116 			uint32_t alt_thresh;
5117 			/*
5118 			 * Compensate for delayed-ack with the d-ack time.
5119 			 */
5120 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5121 			if (alt_thresh > thresh)
5122 				thresh = alt_thresh;
5123 		}
5124 	}
5125 	/* Not above an RTO */
5126 	if (thresh > tp->t_rxtcur) {
5127 		thresh = tp->t_rxtcur;
5128 	}
5129 	/* Not above a RTO max */
5130 	if (thresh > rack_rto_max) {
5131 		thresh = rack_rto_max;
5132 	}
5133 	/* Apply user supplied min TLP */
5134 	if (thresh < rack_tlp_min) {
5135 		thresh = rack_tlp_min;
5136 	}
5137 	return (thresh);
5138 }
5139 
5140 static uint32_t
5141 rack_grab_rtt(struct tcpcb *tp, struct tcp_rack *rack)
5142 {
5143 	/*
5144 	 * We want the rack_rtt which is the
5145 	 * last rtt we measured. However if that
5146 	 * does not exist we fallback to the srtt (which
5147 	 * we probably will never do) and then as a last
5148 	 * resort we use RACK_INITIAL_RTO if no srtt is
5149 	 * yet set.
5150 	 */
5151 	if (rack->rc_rack_rtt)
5152 		return (rack->rc_rack_rtt);
5153 	else if (tp->t_srtt == 0)
5154 		return (RACK_INITIAL_RTO);
5155 	return (tp->t_srtt);
5156 }
5157 
5158 static struct rack_sendmap *
5159 rack_check_recovery_mode(struct tcpcb *tp, uint32_t tsused)
5160 {
5161 	/*
5162 	 * Check to see that we don't need to fall into recovery. We will
5163 	 * need to do so if our oldest transmit is past the time we should
5164 	 * have had an ack.
5165 	 */
5166 	struct tcp_rack *rack;
5167 	struct rack_sendmap *rsm;
5168 	int32_t idx;
5169 	uint32_t srtt, thresh;
5170 
5171 	rack = (struct tcp_rack *)tp->t_fb_ptr;
5172 	if (RB_EMPTY(&rack->r_ctl.rc_mtree)) {
5173 		return (NULL);
5174 	}
5175 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
5176 	if (rsm == NULL)
5177 		return (NULL);
5178 
5179 
5180 	if (rsm->r_flags & RACK_ACKED) {
5181 		rsm = rack_find_lowest_rsm(rack);
5182 		if (rsm == NULL)
5183 			return (NULL);
5184 	}
5185 	idx = rsm->r_rtr_cnt - 1;
5186 	srtt = rack_grab_rtt(tp, rack);
5187 	thresh = rack_calc_thresh_rack(rack, srtt, tsused);
5188 	if (TSTMP_LT(tsused, ((uint32_t)rsm->r_tim_lastsent[idx]))) {
5189 		return (NULL);
5190 	}
5191 	if ((tsused - ((uint32_t)rsm->r_tim_lastsent[idx])) < thresh) {
5192 		return (NULL);
5193 	}
5194 	/* Ok if we reach here we are over-due and this guy can be sent */
5195 	rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
5196 	return (rsm);
5197 }
5198 
5199 static uint32_t
5200 rack_get_persists_timer_val(struct tcpcb *tp, struct tcp_rack *rack)
5201 {
5202 	int32_t t;
5203 	int32_t tt;
5204 	uint32_t ret_val;
5205 
5206 	t = (tp->t_srtt + (tp->t_rttvar << 2));
5207 	RACK_TCPT_RANGESET(tt, t * tcp_backoff[tp->t_rxtshift],
5208  	    rack_persist_min, rack_persist_max, rack->r_ctl.timer_slop);
5209 	rack->r_ctl.rc_hpts_flags |= PACE_TMR_PERSIT;
5210 	ret_val = (uint32_t)tt;
5211 	return (ret_val);
5212 }
5213 
5214 static uint32_t
5215 rack_timer_start(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int sup_rack)
5216 {
5217 	/*
5218 	 * Start the FR timer, we do this based on getting the first one in
5219 	 * the rc_tmap. Note that if its NULL we must stop the timer. in all
5220 	 * events we need to stop the running timer (if its running) before
5221 	 * starting the new one.
5222 	 */
5223 	uint32_t thresh, exp, to, srtt, time_since_sent, tstmp_touse;
5224 	uint32_t srtt_cur;
5225 	int32_t idx;
5226 	int32_t is_tlp_timer = 0;
5227 	struct rack_sendmap *rsm;
5228 
5229 	if (rack->t_timers_stopped) {
5230 		/* All timers have been stopped none are to run */
5231 		return (0);
5232 	}
5233 	if (rack->rc_in_persist) {
5234 		/* We can't start any timer in persists */
5235 		return (rack_get_persists_timer_val(tp, rack));
5236 	}
5237 	rack->rc_on_min_to = 0;
5238 	if ((tp->t_state < TCPS_ESTABLISHED) ||
5239 	    ((tp->t_flags & TF_SACK_PERMIT) == 0)) {
5240 		goto activate_rxt;
5241 	}
5242 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
5243 	if ((rsm == NULL) || sup_rack) {
5244 		/* Nothing on the send map or no rack */
5245 activate_rxt:
5246 		time_since_sent = 0;
5247 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
5248 		if (rsm) {
5249 			/*
5250 			 * Should we discount the RTX timer any?
5251 			 *
5252 			 * We want to discount it the smallest amount.
5253 			 * If a timer (Rack/TLP or RXT) has gone off more
5254 			 * recently thats the discount we want to use (now - timer time).
5255 			 * If the retransmit of the oldest packet was more recent then
5256 			 * we want to use that (now - oldest-packet-last_transmit_time).
5257 			 *
5258 			 */
5259 			idx = rsm->r_rtr_cnt - 1;
5260 			if (TSTMP_GEQ(rack->r_ctl.rc_tlp_rxt_last_time, ((uint32_t)rsm->r_tim_lastsent[idx])))
5261 				tstmp_touse = (uint32_t)rack->r_ctl.rc_tlp_rxt_last_time;
5262 			else
5263 				tstmp_touse = (uint32_t)rsm->r_tim_lastsent[idx];
5264 			if (TSTMP_GT(cts, tstmp_touse))
5265 			    time_since_sent = cts - tstmp_touse;
5266 		}
5267 		if (SEQ_LT(tp->snd_una, tp->snd_max) ||
5268 		    sbavail(&tptosocket(tp)->so_snd)) {
5269 			rack->r_ctl.rc_hpts_flags |= PACE_TMR_RXT;
5270 			to = tp->t_rxtcur;
5271 			if (to > time_since_sent)
5272 				to -= time_since_sent;
5273 			else
5274 				to = rack->r_ctl.rc_min_to;
5275 			if (to == 0)
5276 				to = 1;
5277 			/* Special case for KEEPINIT */
5278 			if ((TCPS_HAVEESTABLISHED(tp->t_state) == 0) &&
5279 			    (TP_KEEPINIT(tp) != 0) &&
5280 			    rsm) {
5281 				/*
5282 				 * We have to put a ceiling on the rxt timer
5283 				 * of the keep-init timeout.
5284 				 */
5285 				uint32_t max_time, red;
5286 
5287 				max_time = TICKS_2_USEC(TP_KEEPINIT(tp));
5288 				if (TSTMP_GT(cts, (uint32_t)rsm->r_tim_lastsent[0])) {
5289 					red = (cts - (uint32_t)rsm->r_tim_lastsent[0]);
5290 					if (red < max_time)
5291 						max_time -= red;
5292 					else
5293 						max_time = 1;
5294 				}
5295 				/* Reduce timeout to the keep value if needed */
5296 				if (max_time < to)
5297 					to = max_time;
5298 			}
5299 			return (to);
5300 		}
5301 		return (0);
5302 	}
5303 	if (rsm->r_flags & RACK_ACKED) {
5304 		rsm = rack_find_lowest_rsm(rack);
5305 		if (rsm == NULL) {
5306 			/* No lowest? */
5307 			goto activate_rxt;
5308 		}
5309 	}
5310 	if (rack->sack_attack_disable) {
5311 		/*
5312 		 * We don't want to do
5313 		 * any TLP's if you are an attacker.
5314 		 * Though if you are doing what
5315 		 * is expected you may still have
5316 		 * SACK-PASSED marks.
5317 		 */
5318 		goto activate_rxt;
5319 	}
5320 	/* Convert from ms to usecs */
5321 	if ((rsm->r_flags & RACK_SACK_PASSED) ||
5322 	    (rsm->r_flags & RACK_RWND_COLLAPSED) ||
5323 	    (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
5324 		if ((tp->t_flags & TF_SENTFIN) &&
5325 		    ((tp->snd_max - tp->snd_una) == 1) &&
5326 		    (rsm->r_flags & RACK_HAS_FIN)) {
5327 			/*
5328 			 * We don't start a rack timer if all we have is a
5329 			 * FIN outstanding.
5330 			 */
5331 			goto activate_rxt;
5332 		}
5333 		if ((rack->use_rack_rr == 0) &&
5334 		    (IN_FASTRECOVERY(tp->t_flags)) &&
5335 		    (rack->rack_no_prr == 0) &&
5336 		     (rack->r_ctl.rc_prr_sndcnt  < ctf_fixed_maxseg(tp))) {
5337 			/*
5338 			 * We are not cheating, in recovery  and
5339 			 * not enough ack's to yet get our next
5340 			 * retransmission out.
5341 			 *
5342 			 * Note that classified attackers do not
5343 			 * get to use the rack-cheat.
5344 			 */
5345 			goto activate_tlp;
5346 		}
5347 		srtt = rack_grab_rtt(tp, rack);
5348 		thresh = rack_calc_thresh_rack(rack, srtt, cts);
5349 		idx = rsm->r_rtr_cnt - 1;
5350 		exp = ((uint32_t)rsm->r_tim_lastsent[idx]) + thresh;
5351 		if (SEQ_GEQ(exp, cts)) {
5352 			to = exp - cts;
5353 			if (to < rack->r_ctl.rc_min_to) {
5354 				to = rack->r_ctl.rc_min_to;
5355 				if (rack->r_rr_config == 3)
5356 					rack->rc_on_min_to = 1;
5357 			}
5358 		} else {
5359 			to = rack->r_ctl.rc_min_to;
5360 			if (rack->r_rr_config == 3)
5361 				rack->rc_on_min_to = 1;
5362 		}
5363 	} else {
5364 		/* Ok we need to do a TLP not RACK */
5365 activate_tlp:
5366 		if ((rack->rc_tlp_in_progress != 0) &&
5367 		    (rack->r_ctl.rc_tlp_cnt_out >= rack_tlp_limit)) {
5368 			/*
5369 			 * The previous send was a TLP and we have sent
5370 			 * N TLP's without sending new data.
5371 			 */
5372 			goto activate_rxt;
5373 		}
5374 		rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
5375 		if (rsm == NULL) {
5376 			/* We found no rsm to TLP with. */
5377 			goto activate_rxt;
5378 		}
5379 		if (rsm->r_flags & RACK_HAS_FIN) {
5380 			/* If its a FIN we dont do TLP */
5381 			rsm = NULL;
5382 			goto activate_rxt;
5383 		}
5384 		idx = rsm->r_rtr_cnt - 1;
5385 		time_since_sent = 0;
5386 		if (TSTMP_GEQ(((uint32_t)rsm->r_tim_lastsent[idx]), rack->r_ctl.rc_tlp_rxt_last_time))
5387 			tstmp_touse = (uint32_t)rsm->r_tim_lastsent[idx];
5388 		else
5389 			tstmp_touse = (uint32_t)rack->r_ctl.rc_tlp_rxt_last_time;
5390 		if (TSTMP_GT(cts, tstmp_touse))
5391 		    time_since_sent = cts - tstmp_touse;
5392 		is_tlp_timer = 1;
5393 		if (tp->t_srtt) {
5394 			if ((rack->rc_srtt_measure_made == 0) &&
5395 			    (tp->t_srtt == 1)) {
5396 				/*
5397 				 * If another stack as run and set srtt to 1,
5398 				 * then the srtt was 0, so lets use the initial.
5399 				 */
5400 				srtt = RACK_INITIAL_RTO;
5401 			} else {
5402 				srtt_cur = tp->t_srtt;
5403 				srtt = srtt_cur;
5404 			}
5405 		} else
5406 			srtt = RACK_INITIAL_RTO;
5407 		/*
5408 		 * If the SRTT is not keeping up and the
5409 		 * rack RTT has spiked we want to use
5410 		 * the last RTT not the smoothed one.
5411 		 */
5412 		if (rack_tlp_use_greater &&
5413 		    tp->t_srtt &&
5414 		    (srtt < rack_grab_rtt(tp, rack))) {
5415 			srtt = rack_grab_rtt(tp, rack);
5416 		}
5417 		thresh = rack_calc_thresh_tlp(tp, rack, rsm, srtt);
5418 		if (thresh > time_since_sent) {
5419 			to = thresh - time_since_sent;
5420 		} else {
5421 			to = rack->r_ctl.rc_min_to;
5422 			rack_log_alt_to_to_cancel(rack,
5423 						  thresh,		/* flex1 */
5424 						  time_since_sent,	/* flex2 */
5425 						  tstmp_touse,		/* flex3 */
5426 						  rack->r_ctl.rc_tlp_rxt_last_time, /* flex4 */
5427 						  (uint32_t)rsm->r_tim_lastsent[idx],
5428 						  srtt,
5429 						  idx, 99);
5430 		}
5431 		if (to < rack_tlp_min) {
5432 			to = rack_tlp_min;
5433 		}
5434 		if (to > TICKS_2_USEC(TCPTV_REXMTMAX)) {
5435 			/*
5436 			 * If the TLP time works out to larger than the max
5437 			 * RTO lets not do TLP.. just RTO.
5438 			 */
5439 			goto activate_rxt;
5440 		}
5441 	}
5442 	if (is_tlp_timer == 0) {
5443 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_RACK;
5444 	} else {
5445 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_TLP;
5446 	}
5447 	if (to == 0)
5448 		to = 1;
5449 	return (to);
5450 }
5451 
5452 static void
5453 rack_enter_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
5454 {
5455 	if (rack->rc_in_persist == 0) {
5456 		if (tp->t_flags & TF_GPUTINPROG) {
5457 			/*
5458 			 * Stop the goodput now, the calling of the
5459 			 * measurement function clears the flag.
5460 			 */
5461 			rack_do_goodput_measurement(tp, rack, tp->snd_una, __LINE__,
5462 						    RACK_QUALITY_PERSIST);
5463 		}
5464 #ifdef NETFLIX_SHARED_CWND
5465 		if (rack->r_ctl.rc_scw) {
5466 			tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
5467 			rack->rack_scwnd_is_idle = 1;
5468 		}
5469 #endif
5470 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
5471 		if (rack->r_ctl.rc_went_idle_time == 0)
5472 			rack->r_ctl.rc_went_idle_time = 1;
5473 		rack_timer_cancel(tp, rack, cts, __LINE__);
5474 		rack->r_ctl.persist_lost_ends = 0;
5475 		rack->probe_not_answered = 0;
5476 		rack->forced_ack = 0;
5477 		tp->t_rxtshift = 0;
5478 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
5479 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
5480 		rack->rc_in_persist = 1;
5481 	}
5482 }
5483 
5484 static void
5485 rack_exit_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
5486 {
5487 	if (tcp_in_hpts(rack->rc_inp)) {
5488 		tcp_hpts_remove(rack->rc_inp);
5489 		rack->r_ctl.rc_hpts_flags = 0;
5490 	}
5491 #ifdef NETFLIX_SHARED_CWND
5492 	if (rack->r_ctl.rc_scw) {
5493 		tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
5494 		rack->rack_scwnd_is_idle = 0;
5495 	}
5496 #endif
5497 	if (rack->rc_gp_dyn_mul &&
5498 	    (rack->use_fixed_rate == 0) &&
5499 	    (rack->rc_always_pace)) {
5500 		/*
5501 		 * Do we count this as if a probe-rtt just
5502 		 * finished?
5503 		 */
5504 		uint32_t time_idle, idle_min;
5505 
5506 		time_idle = tcp_get_usecs(NULL) - rack->r_ctl.rc_went_idle_time;
5507 		idle_min = rack_min_probertt_hold;
5508 		if (rack_probertt_gpsrtt_cnt_div) {
5509 			uint64_t extra;
5510 			extra = (uint64_t)rack->r_ctl.rc_gp_srtt *
5511 				(uint64_t)rack_probertt_gpsrtt_cnt_mul;
5512 			extra /= (uint64_t)rack_probertt_gpsrtt_cnt_div;
5513 			idle_min += (uint32_t)extra;
5514 		}
5515 		if (time_idle >= idle_min) {
5516 			/* Yes, we count it as a probe-rtt. */
5517 			uint32_t us_cts;
5518 
5519 			us_cts = tcp_get_usecs(NULL);
5520 			if (rack->in_probe_rtt == 0) {
5521 				rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
5522 				rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
5523 				rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
5524 				rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
5525 			} else {
5526 				rack_exit_probertt(rack, us_cts);
5527 			}
5528 		}
5529 	}
5530 	rack->rc_in_persist = 0;
5531 	rack->r_ctl.rc_went_idle_time = 0;
5532 	tp->t_rxtshift = 0;
5533 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
5534 	   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
5535 	rack->r_ctl.rc_agg_delayed = 0;
5536 	rack->r_early = 0;
5537 	rack->r_late = 0;
5538 	rack->r_ctl.rc_agg_early = 0;
5539 }
5540 
5541 static void
5542 rack_log_hpts_diag(struct tcp_rack *rack, uint32_t cts,
5543 		   struct hpts_diag *diag, struct timeval *tv)
5544 {
5545 	if (rack_verbose_logging && rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
5546 		union tcp_log_stackspecific log;
5547 
5548 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5549 		log.u_bbr.flex1 = diag->p_nxt_slot;
5550 		log.u_bbr.flex2 = diag->p_cur_slot;
5551 		log.u_bbr.flex3 = diag->slot_req;
5552 		log.u_bbr.flex4 = diag->inp_hptsslot;
5553 		log.u_bbr.flex5 = diag->slot_remaining;
5554 		log.u_bbr.flex6 = diag->need_new_to;
5555 		log.u_bbr.flex7 = diag->p_hpts_active;
5556 		log.u_bbr.flex8 = diag->p_on_min_sleep;
5557 		/* Hijack other fields as needed */
5558 		log.u_bbr.epoch = diag->have_slept;
5559 		log.u_bbr.lt_epoch = diag->yet_to_sleep;
5560 		log.u_bbr.pkts_out = diag->co_ret;
5561 		log.u_bbr.applimited = diag->hpts_sleep_time;
5562 		log.u_bbr.delivered = diag->p_prev_slot;
5563 		log.u_bbr.inflight = diag->p_runningslot;
5564 		log.u_bbr.bw_inuse = diag->wheel_slot;
5565 		log.u_bbr.rttProp = diag->wheel_cts;
5566 		log.u_bbr.timeStamp = cts;
5567 		log.u_bbr.delRate = diag->maxslots;
5568 		log.u_bbr.cur_del_rate = diag->p_curtick;
5569 		log.u_bbr.cur_del_rate <<= 32;
5570 		log.u_bbr.cur_del_rate |= diag->p_lasttick;
5571 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
5572 		    &rack->rc_inp->inp_socket->so_rcv,
5573 		    &rack->rc_inp->inp_socket->so_snd,
5574 		    BBR_LOG_HPTSDIAG, 0,
5575 		    0, &log, false, tv);
5576 	}
5577 
5578 }
5579 
5580 static void
5581 rack_log_wakeup(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb, uint32_t len, int type)
5582 {
5583 	if (rack_verbose_logging && rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
5584 		union tcp_log_stackspecific log;
5585 		struct timeval tv;
5586 
5587 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5588 		log.u_bbr.flex1 = sb->sb_flags;
5589 		log.u_bbr.flex2 = len;
5590 		log.u_bbr.flex3 = sb->sb_state;
5591 		log.u_bbr.flex8 = type;
5592 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5593 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
5594 		    &rack->rc_inp->inp_socket->so_rcv,
5595 		    &rack->rc_inp->inp_socket->so_snd,
5596 		    TCP_LOG_SB_WAKE, 0,
5597 		    len, &log, false, &tv);
5598 	}
5599 }
5600 
5601 static void
5602 rack_start_hpts_timer(struct tcp_rack *rack, struct tcpcb *tp, uint32_t cts,
5603       int32_t slot, uint32_t tot_len_this_send, int sup_rack)
5604 {
5605 	struct hpts_diag diag;
5606 	struct inpcb *inp = tptoinpcb(tp);
5607 	struct timeval tv;
5608 	uint32_t delayed_ack = 0;
5609 	uint32_t hpts_timeout;
5610 	uint32_t entry_slot = slot;
5611 	uint8_t stopped;
5612 	uint32_t left = 0;
5613 	uint32_t us_cts;
5614 
5615 	if ((tp->t_state == TCPS_CLOSED) ||
5616 	    (tp->t_state == TCPS_LISTEN)) {
5617 		return;
5618 	}
5619 	if (tcp_in_hpts(inp)) {
5620 		/* Already on the pacer */
5621 		return;
5622 	}
5623 	stopped = rack->rc_tmr_stopped;
5624 	if (stopped && TSTMP_GT(rack->r_ctl.rc_timer_exp, cts)) {
5625 		left = rack->r_ctl.rc_timer_exp - cts;
5626 	}
5627 	rack->r_ctl.rc_timer_exp = 0;
5628 	rack->r_ctl.rc_hpts_flags = 0;
5629 	us_cts = tcp_get_usecs(&tv);
5630 	/* Now early/late accounting */
5631 	rack_log_pacing_delay_calc(rack, entry_slot, slot, 0, 0, 0, 26, __LINE__, NULL, 0);
5632 	if (rack->r_early && (rack->rc_ack_can_sendout_data == 0)) {
5633 		/*
5634 		 * We have a early carry over set,
5635 		 * we can always add more time so we
5636 		 * can always make this compensation.
5637 		 *
5638 		 * Note if ack's are allowed to wake us do not
5639 		 * penalize the next timer for being awoke
5640 		 * by an ack aka the rc_agg_early (non-paced mode).
5641 		 */
5642 		slot += rack->r_ctl.rc_agg_early;
5643 		rack->r_early = 0;
5644 		rack->r_ctl.rc_agg_early = 0;
5645 	}
5646 	if (rack->r_late) {
5647 		/*
5648 		 * This is harder, we can
5649 		 * compensate some but it
5650 		 * really depends on what
5651 		 * the current pacing time is.
5652 		 */
5653 		if (rack->r_ctl.rc_agg_delayed >= slot) {
5654 			/*
5655 			 * We can't compensate for it all.
5656 			 * And we have to have some time
5657 			 * on the clock. We always have a min
5658 			 * 10 slots (10 x 10 i.e. 100 usecs).
5659 			 */
5660 			if (slot <= HPTS_TICKS_PER_SLOT) {
5661 				/* We gain delay */
5662 				rack->r_ctl.rc_agg_delayed += (HPTS_TICKS_PER_SLOT - slot);
5663 				slot = HPTS_TICKS_PER_SLOT;
5664 			} else {
5665 				/* We take off some */
5666 				rack->r_ctl.rc_agg_delayed -= (slot - HPTS_TICKS_PER_SLOT);
5667 				slot = HPTS_TICKS_PER_SLOT;
5668 			}
5669 		} else {
5670 			slot -= rack->r_ctl.rc_agg_delayed;
5671 			rack->r_ctl.rc_agg_delayed = 0;
5672 			/* Make sure we have 100 useconds at minimum */
5673 			if (slot < HPTS_TICKS_PER_SLOT) {
5674 				rack->r_ctl.rc_agg_delayed = HPTS_TICKS_PER_SLOT - slot;
5675 				slot = HPTS_TICKS_PER_SLOT;
5676 			}
5677 			if (rack->r_ctl.rc_agg_delayed == 0)
5678 				rack->r_late = 0;
5679 		}
5680 	}
5681 	if (slot) {
5682 		/* We are pacing too */
5683 		rack->r_ctl.rc_hpts_flags |= PACE_PKT_OUTPUT;
5684 	}
5685 	hpts_timeout = rack_timer_start(tp, rack, cts, sup_rack);
5686 #ifdef NETFLIX_EXP_DETECTION
5687 	if (rack->sack_attack_disable &&
5688 	    (slot < tcp_sad_pacing_interval)) {
5689 		/*
5690 		 * We have a potential attacker on
5691 		 * the line. We have possibly some
5692 		 * (or now) pacing time set. We want to
5693 		 * slow down the processing of sacks by some
5694 		 * amount (if it is an attacker). Set the default
5695 		 * slot for attackers in place (unless the orginal
5696 		 * interval is longer). Its stored in
5697 		 * micro-seconds, so lets convert to msecs.
5698 		 */
5699 		slot = tcp_sad_pacing_interval;
5700 	}
5701 #endif
5702 	if (tp->t_flags & TF_DELACK) {
5703 		delayed_ack = TICKS_2_USEC(tcp_delacktime);
5704 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_DELACK;
5705 	}
5706 	if (delayed_ack && ((hpts_timeout == 0) ||
5707 			    (delayed_ack < hpts_timeout)))
5708 		hpts_timeout = delayed_ack;
5709 	else
5710 		rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
5711 	/*
5712 	 * If no timers are going to run and we will fall off the hptsi
5713 	 * wheel, we resort to a keep-alive timer if its configured.
5714 	 */
5715 	if ((hpts_timeout == 0) &&
5716 	    (slot == 0)) {
5717 		if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
5718 		    (tp->t_state <= TCPS_CLOSING)) {
5719 			/*
5720 			 * Ok we have no timer (persists, rack, tlp, rxt  or
5721 			 * del-ack), we don't have segments being paced. So
5722 			 * all that is left is the keepalive timer.
5723 			 */
5724 			if (TCPS_HAVEESTABLISHED(tp->t_state)) {
5725 				/* Get the established keep-alive time */
5726 				hpts_timeout = TICKS_2_USEC(TP_KEEPIDLE(tp));
5727 			} else {
5728 				/*
5729 				 * Get the initial setup keep-alive time,
5730 				 * note that this is probably not going to
5731 				 * happen, since rack will be running a rxt timer
5732 				 * if a SYN of some sort is outstanding. It is
5733 				 * actually handled in rack_timeout_rxt().
5734 				 */
5735 				hpts_timeout = TICKS_2_USEC(TP_KEEPINIT(tp));
5736 			}
5737 			rack->r_ctl.rc_hpts_flags |= PACE_TMR_KEEP;
5738 			if (rack->in_probe_rtt) {
5739 				/*
5740 				 * We want to instead not wake up a long time from
5741 				 * now but to wake up about the time we would
5742 				 * exit probe-rtt and initiate a keep-alive ack.
5743 				 * This will get us out of probe-rtt and update
5744 				 * our min-rtt.
5745 				 */
5746 				hpts_timeout = rack_min_probertt_hold;
5747 			}
5748 		}
5749 	}
5750 	if (left && (stopped & (PACE_TMR_KEEP | PACE_TMR_DELACK)) ==
5751 	    (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK)) {
5752 		/*
5753 		 * RACK, TLP, persists and RXT timers all are restartable
5754 		 * based on actions input .. i.e we received a packet (ack
5755 		 * or sack) and that changes things (rw, or snd_una etc).
5756 		 * Thus we can restart them with a new value. For
5757 		 * keep-alive, delayed_ack we keep track of what was left
5758 		 * and restart the timer with a smaller value.
5759 		 */
5760 		if (left < hpts_timeout)
5761 			hpts_timeout = left;
5762 	}
5763 	if (hpts_timeout) {
5764 		/*
5765 		 * Hack alert for now we can't time-out over 2,147,483
5766 		 * seconds (a bit more than 596 hours), which is probably ok
5767 		 * :).
5768 		 */
5769 		if (hpts_timeout > 0x7ffffffe)
5770 			hpts_timeout = 0x7ffffffe;
5771 		rack->r_ctl.rc_timer_exp = cts + hpts_timeout;
5772 	}
5773 	rack_log_pacing_delay_calc(rack, entry_slot, slot, hpts_timeout, 0, 0, 27, __LINE__, NULL, 0);
5774 	if ((rack->gp_ready == 0) &&
5775 	    (rack->use_fixed_rate == 0) &&
5776 	    (hpts_timeout < slot) &&
5777 	    (rack->r_ctl.rc_hpts_flags & (PACE_TMR_TLP|PACE_TMR_RXT))) {
5778 		/*
5779 		 * We have no good estimate yet for the
5780 		 * old clunky burst mitigation or the
5781 		 * real pacing. And the tlp or rxt is smaller
5782 		 * than the pacing calculation. Lets not
5783 		 * pace that long since we know the calculation
5784 		 * so far is not accurate.
5785 		 */
5786 		slot = hpts_timeout;
5787 	}
5788 	/**
5789 	 * Turn off all the flags for queuing by default. The
5790 	 * flags have important meanings to what happens when
5791 	 * LRO interacts with the transport. Most likely (by default now)
5792 	 * mbuf_queueing and ack compression are on. So the transport
5793 	 * has a couple of flags that control what happens (if those
5794 	 * are not on then these flags won't have any effect since it
5795 	 * won't go through the queuing LRO path).
5796 	 *
5797 	 * INP_MBUF_QUEUE_READY - This flags says that I am busy
5798 	 *                        pacing output, so don't disturb. But
5799 	 *                        it also means LRO can wake me if there
5800 	 *                        is a SACK arrival.
5801 	 *
5802 	 * INP_DONT_SACK_QUEUE - This flag is used in conjunction
5803 	 *                       with the above flag (QUEUE_READY) and
5804 	 *                       when present it says don't even wake me
5805 	 *                       if a SACK arrives.
5806 	 *
5807 	 * The idea behind these flags is that if we are pacing we
5808 	 * set the MBUF_QUEUE_READY and only get woken up if
5809 	 * a SACK arrives (which could change things) or if
5810 	 * our pacing timer expires. If, however, we have a rack
5811 	 * timer running, then we don't even want a sack to wake
5812 	 * us since the rack timer has to expire before we can send.
5813 	 *
5814 	 * Other cases should usually have none of the flags set
5815 	 * so LRO can call into us.
5816 	 */
5817 	inp->inp_flags2 &= ~(INP_DONT_SACK_QUEUE|INP_MBUF_QUEUE_READY);
5818 	if (slot) {
5819 		rack->r_ctl.rc_last_output_to = us_cts + slot;
5820 		/*
5821 		 * A pacing timer (slot) is being set, in
5822 		 * such a case we cannot send (we are blocked by
5823 		 * the timer). So lets tell LRO that it should not
5824 		 * wake us unless there is a SACK. Note this only
5825 		 * will be effective if mbuf queueing is on or
5826 		 * compressed acks are being processed.
5827 		 */
5828 		inp->inp_flags2 |= INP_MBUF_QUEUE_READY;
5829 		/*
5830 		 * But wait if we have a Rack timer running
5831 		 * even a SACK should not disturb us (with
5832 		 * the exception of r_rr_config 3).
5833 		 */
5834 		if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK) &&
5835 		    (rack->r_rr_config != 3))
5836 			inp->inp_flags2 |= INP_DONT_SACK_QUEUE;
5837 		if (rack->rc_ack_can_sendout_data) {
5838 			/*
5839 			 * Ahh but wait, this is that special case
5840 			 * where the pacing timer can be disturbed
5841 			 * backout the changes (used for non-paced
5842 			 * burst limiting).
5843 			 */
5844 			inp->inp_flags2 &= ~(INP_DONT_SACK_QUEUE|INP_MBUF_QUEUE_READY);
5845 		}
5846 		if ((rack->use_rack_rr) &&
5847 		    (rack->r_rr_config < 2) &&
5848 		    ((hpts_timeout) && (hpts_timeout < slot))) {
5849 			/*
5850 			 * Arrange for the hpts to kick back in after the
5851 			 * t-o if the t-o does not cause a send.
5852 			 */
5853 			(void)tcp_hpts_insert_diag(inp, HPTS_USEC_TO_SLOTS(hpts_timeout),
5854 						   __LINE__, &diag);
5855 			rack_log_hpts_diag(rack, us_cts, &diag, &tv);
5856 			rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
5857 		} else {
5858 			(void)tcp_hpts_insert_diag(inp, HPTS_USEC_TO_SLOTS(slot),
5859 						   __LINE__, &diag);
5860 			rack_log_hpts_diag(rack, us_cts, &diag, &tv);
5861 			rack_log_to_start(rack, cts, hpts_timeout, slot, 1);
5862 		}
5863 	} else if (hpts_timeout) {
5864 		/*
5865 		 * With respect to inp_flags2 here, lets let any new acks wake
5866 		 * us up here. Since we are not pacing (no pacing timer), output
5867 		 * can happen so we should let it. If its a Rack timer, then any inbound
5868 		 * packet probably won't change the sending (we will be blocked)
5869 		 * but it may change the prr stats so letting it in (the set defaults
5870 		 * at the start of this block) are good enough.
5871 		 */
5872 		(void)tcp_hpts_insert_diag(inp, HPTS_USEC_TO_SLOTS(hpts_timeout),
5873 					   __LINE__, &diag);
5874 		rack_log_hpts_diag(rack, us_cts, &diag, &tv);
5875 		rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
5876 	} else {
5877 		/* No timer starting */
5878 #ifdef INVARIANTS
5879 		if (SEQ_GT(tp->snd_max, tp->snd_una)) {
5880 			panic("tp:%p rack:%p tlts:%d cts:%u slot:%u pto:%u -- no timer started?",
5881 			    tp, rack, tot_len_this_send, cts, slot, hpts_timeout);
5882 		}
5883 #endif
5884 	}
5885 	rack->rc_tmr_stopped = 0;
5886 	if (slot)
5887 		rack_log_type_bbrsnd(rack, tot_len_this_send, slot, us_cts, &tv);
5888 }
5889 
5890 /*
5891  * RACK Timer, here we simply do logging and house keeping.
5892  * the normal rack_output() function will call the
5893  * appropriate thing to check if we need to do a RACK retransmit.
5894  * We return 1, saying don't proceed with rack_output only
5895  * when all timers have been stopped (destroyed PCB?).
5896  */
5897 static int
5898 rack_timeout_rack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
5899 {
5900 	/*
5901 	 * This timer simply provides an internal trigger to send out data.
5902 	 * The check_recovery_mode call will see if there are needed
5903 	 * retransmissions, if so we will enter fast-recovery. The output
5904 	 * call may or may not do the same thing depending on sysctl
5905 	 * settings.
5906 	 */
5907 	struct rack_sendmap *rsm;
5908 
5909 	counter_u64_add(rack_to_tot, 1);
5910 	if (rack->r_state && (rack->r_state != tp->t_state))
5911 		rack_set_state(tp, rack);
5912 	rack->rc_on_min_to = 0;
5913 	rsm = rack_check_recovery_mode(tp, cts);
5914 	rack_log_to_event(rack, RACK_TO_FRM_RACK, rsm);
5915 	if (rsm) {
5916 		rack->r_ctl.rc_resend = rsm;
5917 		rack->r_timer_override = 1;
5918 		if (rack->use_rack_rr) {
5919 			/*
5920 			 * Don't accumulate extra pacing delay
5921 			 * we are allowing the rack timer to
5922 			 * over-ride pacing i.e. rrr takes precedence
5923 			 * if the pacing interval is longer than the rrr
5924 			 * time (in other words we get the min pacing
5925 			 * time versus rrr pacing time).
5926 			 */
5927 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
5928 		}
5929 	}
5930 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RACK;
5931 	if (rsm == NULL) {
5932 		/* restart a timer and return 1 */
5933 		rack_start_hpts_timer(rack, tp, cts,
5934 				      0, 0, 0);
5935 		return (1);
5936 	}
5937 	return (0);
5938 }
5939 
5940 static void
5941 rack_adjust_orig_mlen(struct rack_sendmap *rsm)
5942 {
5943 	if (rsm->m->m_len > rsm->orig_m_len) {
5944 		/*
5945 		 * Mbuf grew, caused by sbcompress, our offset does
5946 		 * not change.
5947 		 */
5948 		rsm->orig_m_len = rsm->m->m_len;
5949 	} else if (rsm->m->m_len < rsm->orig_m_len) {
5950 		/*
5951 		 * Mbuf shrank, trimmed off the top by an ack, our
5952 		 * offset changes.
5953 		 */
5954 		rsm->soff -= (rsm->orig_m_len - rsm->m->m_len);
5955 		rsm->orig_m_len = rsm->m->m_len;
5956 	}
5957 }
5958 
5959 static void
5960 rack_setup_offset_for_rsm(struct rack_sendmap *src_rsm, struct rack_sendmap *rsm)
5961 {
5962 	struct mbuf *m;
5963 	uint32_t soff;
5964 
5965 	if (src_rsm->m && (src_rsm->orig_m_len != src_rsm->m->m_len)) {
5966 		/* Fix up the orig_m_len and possibly the mbuf offset */
5967 		rack_adjust_orig_mlen(src_rsm);
5968 	}
5969 	m = src_rsm->m;
5970 	soff = src_rsm->soff + (src_rsm->r_end - src_rsm->r_start);
5971 	while (soff >= m->m_len) {
5972 		/* Move out past this mbuf */
5973 		soff -= m->m_len;
5974 		m = m->m_next;
5975 		KASSERT((m != NULL),
5976 			("rsm:%p nrsm:%p hit at soff:%u null m",
5977 			 src_rsm, rsm, soff));
5978 	}
5979 	rsm->m = m;
5980 	rsm->soff = soff;
5981 	rsm->orig_m_len = m->m_len;
5982 }
5983 
5984 static __inline void
5985 rack_clone_rsm(struct tcp_rack *rack, struct rack_sendmap *nrsm,
5986 	       struct rack_sendmap *rsm, uint32_t start)
5987 {
5988 	int idx;
5989 
5990 	nrsm->r_start = start;
5991 	nrsm->r_end = rsm->r_end;
5992 	nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
5993 	nrsm->r_flags = rsm->r_flags;
5994 	nrsm->r_dupack = rsm->r_dupack;
5995 	nrsm->r_no_rtt_allowed = rsm->r_no_rtt_allowed;
5996 	nrsm->r_rtr_bytes = 0;
5997 	nrsm->r_fas = rsm->r_fas;
5998 	rsm->r_end = nrsm->r_start;
5999 	nrsm->r_just_ret = rsm->r_just_ret;
6000 	for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
6001 		nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
6002 	}
6003 	/* Now if we have SYN flag we keep it on the left edge */
6004 	if (nrsm->r_flags & RACK_HAS_SYN)
6005 		nrsm->r_flags &= ~RACK_HAS_SYN;
6006 	/* Now if we have a FIN flag we keep it on the right edge */
6007 	if (rsm->r_flags & RACK_HAS_FIN)
6008 		rsm->r_flags &= ~RACK_HAS_FIN;
6009 	/* Push bit must go to the right edge as well */
6010 	if (rsm->r_flags & RACK_HAD_PUSH)
6011 		rsm->r_flags &= ~RACK_HAD_PUSH;
6012 	/* Clone over the state of the hw_tls flag */
6013 	nrsm->r_hw_tls = rsm->r_hw_tls;
6014 	/*
6015 	 * Now we need to find nrsm's new location in the mbuf chain
6016 	 * we basically calculate a new offset, which is soff +
6017 	 * how much is left in original rsm. Then we walk out the mbuf
6018 	 * chain to find the righ position, it may be the same mbuf
6019 	 * or maybe not.
6020 	 */
6021 	KASSERT(((rsm->m != NULL) ||
6022 		 (rsm->r_flags & (RACK_HAS_SYN|RACK_HAS_FIN))),
6023 		("rsm:%p nrsm:%p rack:%p -- rsm->m is NULL?", rsm, nrsm, rack));
6024 	if (rsm->m)
6025 		rack_setup_offset_for_rsm(rsm, nrsm);
6026 }
6027 
6028 static struct rack_sendmap *
6029 rack_merge_rsm(struct tcp_rack *rack,
6030 	       struct rack_sendmap *l_rsm,
6031 	       struct rack_sendmap *r_rsm)
6032 {
6033 	/*
6034 	 * We are merging two ack'd RSM's,
6035 	 * the l_rsm is on the left (lower seq
6036 	 * values) and the r_rsm is on the right
6037 	 * (higher seq value). The simplest way
6038 	 * to merge these is to move the right
6039 	 * one into the left. I don't think there
6040 	 * is any reason we need to try to find
6041 	 * the oldest (or last oldest retransmitted).
6042 	 */
6043 #ifdef INVARIANTS
6044 	struct rack_sendmap *rm;
6045 #endif
6046 	rack_log_map_chg(rack->rc_tp, rack, NULL,
6047 			 l_rsm, r_rsm, MAP_MERGE, r_rsm->r_end, __LINE__);
6048 	l_rsm->r_end = r_rsm->r_end;
6049 	if (l_rsm->r_dupack < r_rsm->r_dupack)
6050 		l_rsm->r_dupack = r_rsm->r_dupack;
6051 	if (r_rsm->r_rtr_bytes)
6052 		l_rsm->r_rtr_bytes += r_rsm->r_rtr_bytes;
6053 	if (r_rsm->r_in_tmap) {
6054 		/* This really should not happen */
6055 		TAILQ_REMOVE(&rack->r_ctl.rc_tmap, r_rsm, r_tnext);
6056 		r_rsm->r_in_tmap = 0;
6057 	}
6058 
6059 	/* Now the flags */
6060 	if (r_rsm->r_flags & RACK_HAS_FIN)
6061 		l_rsm->r_flags |= RACK_HAS_FIN;
6062 	if (r_rsm->r_flags & RACK_TLP)
6063 		l_rsm->r_flags |= RACK_TLP;
6064 	if (r_rsm->r_flags & RACK_RWND_COLLAPSED)
6065 		l_rsm->r_flags |= RACK_RWND_COLLAPSED;
6066 	if ((r_rsm->r_flags & RACK_APP_LIMITED)  &&
6067 	    ((l_rsm->r_flags & RACK_APP_LIMITED) == 0)) {
6068 		/*
6069 		 * If both are app-limited then let the
6070 		 * free lower the count. If right is app
6071 		 * limited and left is not, transfer.
6072 		 */
6073 		l_rsm->r_flags |= RACK_APP_LIMITED;
6074 		r_rsm->r_flags &= ~RACK_APP_LIMITED;
6075 		if (r_rsm == rack->r_ctl.rc_first_appl)
6076 			rack->r_ctl.rc_first_appl = l_rsm;
6077 	}
6078 #ifndef INVARIANTS
6079 	(void)RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, r_rsm);
6080 #else
6081 	rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, r_rsm);
6082 	if (rm != r_rsm) {
6083 		panic("removing head in rack:%p rsm:%p rm:%p",
6084 		      rack, r_rsm, rm);
6085 	}
6086 #endif
6087 	if ((r_rsm->r_limit_type == 0) && (l_rsm->r_limit_type != 0)) {
6088 		/* Transfer the split limit to the map we free */
6089 		r_rsm->r_limit_type = l_rsm->r_limit_type;
6090 		l_rsm->r_limit_type = 0;
6091 	}
6092 	rack_free(rack, r_rsm);
6093 	return (l_rsm);
6094 }
6095 
6096 /*
6097  * TLP Timer, here we simply setup what segment we want to
6098  * have the TLP expire on, the normal rack_output() will then
6099  * send it out.
6100  *
6101  * We return 1, saying don't proceed with rack_output only
6102  * when all timers have been stopped (destroyed PCB?).
6103  */
6104 static int
6105 rack_timeout_tlp(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t *doing_tlp)
6106 {
6107 	/*
6108 	 * Tail Loss Probe.
6109 	 */
6110 	struct rack_sendmap *rsm = NULL;
6111 #ifdef INVARIANTS
6112 	struct rack_sendmap *insret;
6113 #endif
6114 	struct socket *so = tptosocket(tp);
6115 	uint32_t amm;
6116 	uint32_t out, avail;
6117 	int collapsed_win = 0;
6118 
6119 	if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
6120 		/* Its not time yet */
6121 		return (0);
6122 	}
6123 	if (ctf_progress_timeout_check(tp, true)) {
6124 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
6125 		return (-ETIMEDOUT);	/* tcp_drop() */
6126 	}
6127 	/*
6128 	 * A TLP timer has expired. We have been idle for 2 rtts. So we now
6129 	 * need to figure out how to force a full MSS segment out.
6130 	 */
6131 	rack_log_to_event(rack, RACK_TO_FRM_TLP, NULL);
6132 	rack->r_ctl.retran_during_recovery = 0;
6133 	rack->r_ctl.dsack_byte_cnt = 0;
6134 	counter_u64_add(rack_tlp_tot, 1);
6135 	if (rack->r_state && (rack->r_state != tp->t_state))
6136 		rack_set_state(tp, rack);
6137 	avail = sbavail(&so->so_snd);
6138 	out = tp->snd_max - tp->snd_una;
6139 	if ((out > tp->snd_wnd) || rack->rc_has_collapsed) {
6140 		/* special case, we need a retransmission */
6141 		collapsed_win = 1;
6142 		goto need_retran;
6143 	}
6144 	if (rack->r_ctl.dsack_persist && (rack->r_ctl.rc_tlp_cnt_out >= 1)) {
6145 		rack->r_ctl.dsack_persist--;
6146 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
6147 			rack->r_ctl.num_dsack = 0;
6148 		}
6149 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
6150 	}
6151 	if ((tp->t_flags & TF_GPUTINPROG) &&
6152 	    (rack->r_ctl.rc_tlp_cnt_out == 1)) {
6153 		/*
6154 		 * If this is the second in a row
6155 		 * TLP and we are doing a measurement
6156 		 * its time to abandon the measurement.
6157 		 * Something is likely broken on
6158 		 * the clients network and measuring a
6159 		 * broken network does us no good.
6160 		 */
6161 		tp->t_flags &= ~TF_GPUTINPROG;
6162 		rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
6163 					   rack->r_ctl.rc_gp_srtt /*flex1*/,
6164 					   tp->gput_seq,
6165 					   0, 0, 18, __LINE__, NULL, 0);
6166 	}
6167 	/*
6168 	 * Check our send oldest always settings, and if
6169 	 * there is an oldest to send jump to the need_retran.
6170 	 */
6171 	if (rack_always_send_oldest && (TAILQ_EMPTY(&rack->r_ctl.rc_tmap) == 0))
6172 		goto need_retran;
6173 
6174 	if (avail > out) {
6175 		/* New data is available */
6176 		amm = avail - out;
6177 		if (amm > ctf_fixed_maxseg(tp)) {
6178 			amm = ctf_fixed_maxseg(tp);
6179 			if ((amm + out) > tp->snd_wnd) {
6180 				/* We are rwnd limited */
6181 				goto need_retran;
6182 			}
6183 		} else if (amm < ctf_fixed_maxseg(tp)) {
6184 			/* not enough to fill a MTU */
6185 			goto need_retran;
6186 		}
6187 		if (IN_FASTRECOVERY(tp->t_flags)) {
6188 			/* Unlikely */
6189 			if (rack->rack_no_prr == 0) {
6190 				if (out + amm <= tp->snd_wnd) {
6191 					rack->r_ctl.rc_prr_sndcnt = amm;
6192 					rack->r_ctl.rc_tlp_new_data = amm;
6193 					rack_log_to_prr(rack, 4, 0, __LINE__);
6194 				}
6195 			} else
6196 				goto need_retran;
6197 		} else {
6198 			/* Set the send-new override */
6199 			if (out + amm <= tp->snd_wnd)
6200 				rack->r_ctl.rc_tlp_new_data = amm;
6201 			else
6202 				goto need_retran;
6203 		}
6204 		rack->r_ctl.rc_tlpsend = NULL;
6205 		counter_u64_add(rack_tlp_newdata, 1);
6206 		goto send;
6207 	}
6208 need_retran:
6209 	/*
6210 	 * Ok we need to arrange the last un-acked segment to be re-sent, or
6211 	 * optionally the first un-acked segment.
6212 	 */
6213 	if (collapsed_win == 0) {
6214 		if (rack_always_send_oldest)
6215 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
6216 		else {
6217 			rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6218 			if (rsm && (rsm->r_flags & (RACK_ACKED | RACK_HAS_FIN))) {
6219 				rsm = rack_find_high_nonack(rack, rsm);
6220 			}
6221 		}
6222 		if (rsm == NULL) {
6223 #ifdef TCP_BLACKBOX
6224 			tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
6225 #endif
6226 			goto out;
6227 		}
6228 	} else {
6229 		/*
6230 		 * We must find the last segment
6231 		 * that was acceptable by the client.
6232 		 */
6233 		RB_FOREACH_REVERSE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
6234 			if ((rsm->r_flags & RACK_RWND_COLLAPSED) == 0) {
6235 				/* Found one */
6236 				break;
6237 			}
6238 		}
6239 		if (rsm == NULL) {
6240 			/* None? if so send the first */
6241 			rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6242 			if (rsm == NULL) {
6243 #ifdef TCP_BLACKBOX
6244 				tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
6245 #endif
6246 				goto out;
6247 			}
6248 		}
6249 	}
6250 	if ((rsm->r_end - rsm->r_start) > ctf_fixed_maxseg(tp)) {
6251 		/*
6252 		 * We need to split this the last segment in two.
6253 		 */
6254 		struct rack_sendmap *nrsm;
6255 
6256 		nrsm = rack_alloc_full_limit(rack);
6257 		if (nrsm == NULL) {
6258 			/*
6259 			 * No memory to split, we will just exit and punt
6260 			 * off to the RXT timer.
6261 			 */
6262 			goto out;
6263 		}
6264 		rack_clone_rsm(rack, nrsm, rsm,
6265 			       (rsm->r_end - ctf_fixed_maxseg(tp)));
6266 		rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
6267 #ifndef INVARIANTS
6268 		(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
6269 #else
6270 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
6271 		if (insret != NULL) {
6272 			panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
6273 			      nrsm, insret, rack, rsm);
6274 		}
6275 #endif
6276 		if (rsm->r_in_tmap) {
6277 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
6278 			nrsm->r_in_tmap = 1;
6279 		}
6280 		rsm = nrsm;
6281 	}
6282 	rack->r_ctl.rc_tlpsend = rsm;
6283 send:
6284 	/* Make sure output path knows we are doing a TLP */
6285 	*doing_tlp = 1;
6286 	rack->r_timer_override = 1;
6287 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
6288 	return (0);
6289 out:
6290 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
6291 	return (0);
6292 }
6293 
6294 /*
6295  * Delayed ack Timer, here we simply need to setup the
6296  * ACK_NOW flag and remove the DELACK flag. From there
6297  * the output routine will send the ack out.
6298  *
6299  * We only return 1, saying don't proceed, if all timers
6300  * are stopped (destroyed PCB?).
6301  */
6302 static int
6303 rack_timeout_delack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6304 {
6305 
6306 	rack_log_to_event(rack, RACK_TO_FRM_DELACK, NULL);
6307 	tp->t_flags &= ~TF_DELACK;
6308 	tp->t_flags |= TF_ACKNOW;
6309 	KMOD_TCPSTAT_INC(tcps_delack);
6310 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
6311 	return (0);
6312 }
6313 
6314 /*
6315  * Persists timer, here we simply send the
6316  * same thing as a keepalive will.
6317  * the one byte send.
6318  *
6319  * We only return 1, saying don't proceed, if all timers
6320  * are stopped (destroyed PCB?).
6321  */
6322 static int
6323 rack_timeout_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6324 {
6325 	struct tcptemp *t_template;
6326 	int32_t retval = 1;
6327 
6328 	if (rack->rc_in_persist == 0)
6329 		return (0);
6330 	if (ctf_progress_timeout_check(tp, false)) {
6331 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
6332 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
6333 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
6334 		return (-ETIMEDOUT);	/* tcp_drop() */
6335 	}
6336 	/*
6337 	 * Persistence timer into zero window. Force a byte to be output, if
6338 	 * possible.
6339 	 */
6340 	KMOD_TCPSTAT_INC(tcps_persisttimeo);
6341 	/*
6342 	 * Hack: if the peer is dead/unreachable, we do not time out if the
6343 	 * window is closed.  After a full backoff, drop the connection if
6344 	 * the idle time (no responses to probes) reaches the maximum
6345 	 * backoff that we would use if retransmitting.
6346 	 */
6347 	if (tp->t_rxtshift == TCP_MAXRXTSHIFT &&
6348 	    (ticks - tp->t_rcvtime >= tcp_maxpersistidle ||
6349 	     TICKS_2_USEC(ticks - tp->t_rcvtime) >= RACK_REXMTVAL(tp) * tcp_totbackoff)) {
6350 		KMOD_TCPSTAT_INC(tcps_persistdrop);
6351 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
6352 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
6353 		retval = -ETIMEDOUT;	/* tcp_drop() */
6354 		goto out;
6355 	}
6356 	if ((sbavail(&rack->rc_inp->inp_socket->so_snd) == 0) &&
6357 	    tp->snd_una == tp->snd_max)
6358 		rack_exit_persist(tp, rack, cts);
6359 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_PERSIT;
6360 	/*
6361 	 * If the user has closed the socket then drop a persisting
6362 	 * connection after a much reduced timeout.
6363 	 */
6364 	if (tp->t_state > TCPS_CLOSE_WAIT &&
6365 	    (ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) {
6366 		KMOD_TCPSTAT_INC(tcps_persistdrop);
6367 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
6368 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
6369 		retval = -ETIMEDOUT;	/* tcp_drop() */
6370 		goto out;
6371 	}
6372 	t_template = tcpip_maketemplate(rack->rc_inp);
6373 	if (t_template) {
6374 		/* only set it if we were answered */
6375 		if (rack->forced_ack == 0) {
6376 			rack->forced_ack = 1;
6377 			rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
6378 		} else {
6379 			rack->probe_not_answered = 1;
6380 			counter_u64_add(rack_persists_loss, 1);
6381 			rack->r_ctl.persist_lost_ends++;
6382 		}
6383 		counter_u64_add(rack_persists_sends, 1);
6384 		tcp_respond(tp, t_template->tt_ipgen,
6385 			    &t_template->tt_t, (struct mbuf *)NULL,
6386 			    tp->rcv_nxt, tp->snd_una - 1, 0);
6387 		/* This sends an ack */
6388 		if (tp->t_flags & TF_DELACK)
6389 			tp->t_flags &= ~TF_DELACK;
6390 		free(t_template, M_TEMP);
6391 	}
6392 	if (tp->t_rxtshift < TCP_MAXRXTSHIFT)
6393 		tp->t_rxtshift++;
6394 out:
6395 	rack_log_to_event(rack, RACK_TO_FRM_PERSIST, NULL);
6396 	rack_start_hpts_timer(rack, tp, cts,
6397 			      0, 0, 0);
6398 	return (retval);
6399 }
6400 
6401 /*
6402  * If a keepalive goes off, we had no other timers
6403  * happening. We always return 1 here since this
6404  * routine either drops the connection or sends
6405  * out a segment with respond.
6406  */
6407 static int
6408 rack_timeout_keepalive(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6409 {
6410 	struct tcptemp *t_template;
6411 	struct inpcb *inp = tptoinpcb(tp);
6412 
6413 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_KEEP;
6414 	rack_log_to_event(rack, RACK_TO_FRM_KEEP, NULL);
6415 	/*
6416 	 * Keep-alive timer went off; send something or drop connection if
6417 	 * idle for too long.
6418 	 */
6419 	KMOD_TCPSTAT_INC(tcps_keeptimeo);
6420 	if (tp->t_state < TCPS_ESTABLISHED)
6421 		goto dropit;
6422 	if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
6423 	    tp->t_state <= TCPS_CLOSING) {
6424 		if (ticks - tp->t_rcvtime >= TP_KEEPIDLE(tp) + TP_MAXIDLE(tp))
6425 			goto dropit;
6426 		/*
6427 		 * Send a packet designed to force a response if the peer is
6428 		 * up and reachable: either an ACK if the connection is
6429 		 * still alive, or an RST if the peer has closed the
6430 		 * connection due to timeout or reboot. Using sequence
6431 		 * number tp->snd_una-1 causes the transmitted zero-length
6432 		 * segment to lie outside the receive window; by the
6433 		 * protocol spec, this requires the correspondent TCP to
6434 		 * respond.
6435 		 */
6436 		KMOD_TCPSTAT_INC(tcps_keepprobe);
6437 		t_template = tcpip_maketemplate(inp);
6438 		if (t_template) {
6439 			if (rack->forced_ack == 0) {
6440 				rack->forced_ack = 1;
6441 				rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
6442 			} else {
6443 				rack->probe_not_answered = 1;
6444 			}
6445 			tcp_respond(tp, t_template->tt_ipgen,
6446 			    &t_template->tt_t, (struct mbuf *)NULL,
6447 			    tp->rcv_nxt, tp->snd_una - 1, 0);
6448 			free(t_template, M_TEMP);
6449 		}
6450 	}
6451 	rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
6452 	return (1);
6453 dropit:
6454 	KMOD_TCPSTAT_INC(tcps_keepdrops);
6455 	tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
6456 	return (-ETIMEDOUT);	/* tcp_drop() */
6457 }
6458 
6459 /*
6460  * Retransmit helper function, clear up all the ack
6461  * flags and take care of important book keeping.
6462  */
6463 static void
6464 rack_remxt_tmr(struct tcpcb *tp)
6465 {
6466 	/*
6467 	 * The retransmit timer went off, all sack'd blocks must be
6468 	 * un-acked.
6469 	 */
6470 	struct rack_sendmap *rsm, *trsm = NULL;
6471 	struct tcp_rack *rack;
6472 
6473 	rack = (struct tcp_rack *)tp->t_fb_ptr;
6474 	rack_timer_cancel(tp, rack, tcp_get_usecs(NULL), __LINE__);
6475 	rack_log_to_event(rack, RACK_TO_FRM_TMR, NULL);
6476 	if (rack->r_state && (rack->r_state != tp->t_state))
6477 		rack_set_state(tp, rack);
6478 	/*
6479 	 * Ideally we would like to be able to
6480 	 * mark SACK-PASS on anything not acked here.
6481 	 *
6482 	 * However, if we do that we would burst out
6483 	 * all that data 1ms apart. This would be unwise,
6484 	 * so for now we will just let the normal rxt timer
6485 	 * and tlp timer take care of it.
6486 	 *
6487 	 * Also we really need to stick them back in sequence
6488 	 * order. This way we send in the proper order and any
6489 	 * sacks that come floating in will "re-ack" the data.
6490 	 * To do this we zap the tmap with an INIT and then
6491 	 * walk through and place every rsm in the RB tree
6492 	 * back in its seq ordered place.
6493 	 */
6494 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
6495 	RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
6496 		rsm->r_dupack = 0;
6497 		rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
6498 		/* We must re-add it back to the tlist */
6499 		if (trsm == NULL) {
6500 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
6501 		} else {
6502 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, trsm, rsm, r_tnext);
6503 		}
6504 		rsm->r_in_tmap = 1;
6505 		trsm = rsm;
6506 		if (rsm->r_flags & RACK_ACKED)
6507 			rsm->r_flags |= RACK_WAS_ACKED;
6508 		rsm->r_flags &= ~(RACK_ACKED | RACK_SACK_PASSED | RACK_WAS_SACKPASS | RACK_RWND_COLLAPSED);
6509 		rsm->r_flags |= RACK_MUST_RXT;
6510 	}
6511 	/* Clear the count (we just un-acked them) */
6512 	rack->r_ctl.rc_last_timeout_snduna = tp->snd_una;
6513 	rack->r_ctl.rc_sacked = 0;
6514 	rack->r_ctl.rc_sacklast = NULL;
6515 	rack->r_ctl.rc_agg_delayed = 0;
6516 	rack->r_early = 0;
6517 	rack->r_ctl.rc_agg_early = 0;
6518 	rack->r_late = 0;
6519 	/* Clear the tlp rtx mark */
6520 	rack->r_ctl.rc_resend = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6521 	if (rack->r_ctl.rc_resend != NULL)
6522 		rack->r_ctl.rc_resend->r_flags |= RACK_TO_REXT;
6523 	rack->r_ctl.rc_prr_sndcnt = 0;
6524 	rack_log_to_prr(rack, 6, 0, __LINE__);
6525 	rack->r_timer_override = 1;
6526 	if ((((tp->t_flags & TF_SACK_PERMIT) == 0)
6527 #ifdef NETFLIX_EXP_DETECTION
6528 	    || (rack->sack_attack_disable != 0)
6529 #endif
6530 		    ) && ((tp->t_flags & TF_SENTFIN) == 0)) {
6531 		/*
6532 		 * For non-sack customers new data
6533 		 * needs to go out as retransmits until
6534 		 * we retransmit up to snd_max.
6535 		 */
6536 		rack->r_must_retran = 1;
6537 		rack->r_ctl.rc_out_at_rto = ctf_flight_size(rack->rc_tp,
6538 						rack->r_ctl.rc_sacked);
6539 	}
6540 	rack->r_ctl.rc_snd_max_at_rto = tp->snd_max;
6541 }
6542 
6543 static void
6544 rack_convert_rtts(struct tcpcb *tp)
6545 {
6546 	if (tp->t_srtt > 1) {
6547 		uint32_t val, frac;
6548 
6549 		val = tp->t_srtt >> TCP_RTT_SHIFT;
6550 		frac = tp->t_srtt & 0x1f;
6551 		tp->t_srtt = TICKS_2_USEC(val);
6552 		/*
6553 		 * frac is the fractional part of the srtt (if any)
6554 		 * but its in ticks and every bit represents
6555 		 * 1/32nd of a hz.
6556 		 */
6557 		if (frac) {
6558 			if (hz == 1000) {
6559 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_MSEC) / (uint64_t)TCP_RTT_SCALE);
6560 			} else {
6561 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_SEC) / ((uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE));
6562 			}
6563 			tp->t_srtt += frac;
6564 		}
6565 	}
6566 	if (tp->t_rttvar) {
6567 		uint32_t val, frac;
6568 
6569 		val = tp->t_rttvar >> TCP_RTTVAR_SHIFT;
6570 		frac = tp->t_rttvar & 0x1f;
6571 		tp->t_rttvar = TICKS_2_USEC(val);
6572 		/*
6573 		 * frac is the fractional part of the srtt (if any)
6574 		 * but its in ticks and every bit represents
6575 		 * 1/32nd of a hz.
6576 		 */
6577 		if (frac) {
6578 			if (hz == 1000) {
6579 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_MSEC) / (uint64_t)TCP_RTT_SCALE);
6580 			} else {
6581 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_SEC) / ((uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE));
6582 			}
6583 			tp->t_rttvar += frac;
6584 		}
6585 	}
6586 	tp->t_rxtcur = RACK_REXMTVAL(tp);
6587 	if (TCPS_HAVEESTABLISHED(tp->t_state)) {
6588 		tp->t_rxtcur += TICKS_2_USEC(tcp_rexmit_slop);
6589 	}
6590 	if (tp->t_rxtcur > rack_rto_max) {
6591 		tp->t_rxtcur = rack_rto_max;
6592 	}
6593 }
6594 
6595 static void
6596 rack_cc_conn_init(struct tcpcb *tp)
6597 {
6598 	struct tcp_rack *rack;
6599 	uint32_t srtt;
6600 
6601 	rack = (struct tcp_rack *)tp->t_fb_ptr;
6602 	srtt = tp->t_srtt;
6603 	cc_conn_init(tp);
6604 	/*
6605 	 * Now convert to rack's internal format,
6606 	 * if required.
6607 	 */
6608 	if ((srtt == 0) && (tp->t_srtt != 0))
6609 		rack_convert_rtts(tp);
6610 	/*
6611 	 * We want a chance to stay in slowstart as
6612 	 * we create a connection. TCP spec says that
6613 	 * initially ssthresh is infinite. For our
6614 	 * purposes that is the snd_wnd.
6615 	 */
6616 	if (tp->snd_ssthresh < tp->snd_wnd) {
6617 		tp->snd_ssthresh = tp->snd_wnd;
6618 	}
6619 	/*
6620 	 * We also want to assure a IW worth of
6621 	 * data can get inflight.
6622 	 */
6623 	if (rc_init_window(rack) < tp->snd_cwnd)
6624 		tp->snd_cwnd = rc_init_window(rack);
6625 }
6626 
6627 /*
6628  * Re-transmit timeout! If we drop the PCB we will return 1, otherwise
6629  * we will setup to retransmit the lowest seq number outstanding.
6630  */
6631 static int
6632 rack_timeout_rxt(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6633 {
6634 	struct inpcb *inp = tptoinpcb(tp);
6635 	int32_t rexmt;
6636 	int32_t retval = 0;
6637 	bool isipv6;
6638 
6639 	if ((tp->t_flags & TF_GPUTINPROG) &&
6640 	    (tp->t_rxtshift)) {
6641 		/*
6642 		 * We have had a second timeout
6643 		 * measurements on successive rxt's are not profitable.
6644 		 * It is unlikely to be of any use (the network is
6645 		 * broken or the client went away).
6646 		 */
6647 		tp->t_flags &= ~TF_GPUTINPROG;
6648 		rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
6649 					   rack->r_ctl.rc_gp_srtt /*flex1*/,
6650 					   tp->gput_seq,
6651 					   0, 0, 18, __LINE__, NULL, 0);
6652 	}
6653 	if (ctf_progress_timeout_check(tp, false)) {
6654 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
6655 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
6656 		return (-ETIMEDOUT);	/* tcp_drop() */
6657 	}
6658 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RXT;
6659 	rack->r_ctl.retran_during_recovery = 0;
6660 	rack->rc_ack_required = 1;
6661 	rack->r_ctl.dsack_byte_cnt = 0;
6662 	if (IN_FASTRECOVERY(tp->t_flags))
6663 		tp->t_flags |= TF_WASFRECOVERY;
6664 	else
6665 		tp->t_flags &= ~TF_WASFRECOVERY;
6666 	if (IN_CONGRECOVERY(tp->t_flags))
6667 		tp->t_flags |= TF_WASCRECOVERY;
6668 	else
6669 		tp->t_flags &= ~TF_WASCRECOVERY;
6670 	if (TCPS_HAVEESTABLISHED(tp->t_state) &&
6671 	    (tp->snd_una == tp->snd_max)) {
6672 		/* Nothing outstanding .. nothing to do */
6673 		return (0);
6674 	}
6675 	if (rack->r_ctl.dsack_persist) {
6676 		rack->r_ctl.dsack_persist--;
6677 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
6678 			rack->r_ctl.num_dsack = 0;
6679 		}
6680 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
6681 	}
6682 	/*
6683 	 * Rack can only run one timer  at a time, so we cannot
6684 	 * run a KEEPINIT (gating SYN sending) and a retransmit
6685 	 * timer for the SYN. So if we are in a front state and
6686 	 * have a KEEPINIT timer we need to check the first transmit
6687 	 * against now to see if we have exceeded the KEEPINIT time
6688 	 * (if one is set).
6689 	 */
6690 	if ((TCPS_HAVEESTABLISHED(tp->t_state) == 0) &&
6691 	    (TP_KEEPINIT(tp) != 0)) {
6692 		struct rack_sendmap *rsm;
6693 
6694 		rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6695 		if (rsm) {
6696 			/* Ok we have something outstanding to test keepinit with */
6697 			if ((TSTMP_GT(cts, (uint32_t)rsm->r_tim_lastsent[0])) &&
6698 			    ((cts - (uint32_t)rsm->r_tim_lastsent[0]) >= TICKS_2_USEC(TP_KEEPINIT(tp)))) {
6699 				/* We have exceeded the KEEPINIT time */
6700 				tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
6701 				goto drop_it;
6702 			}
6703 		}
6704 	}
6705 	/*
6706 	 * Retransmission timer went off.  Message has not been acked within
6707 	 * retransmit interval.  Back off to a longer retransmit interval
6708 	 * and retransmit one segment.
6709 	 */
6710 	rack_remxt_tmr(tp);
6711 	if ((rack->r_ctl.rc_resend == NULL) ||
6712 	    ((rack->r_ctl.rc_resend->r_flags & RACK_RWND_COLLAPSED) == 0)) {
6713 		/*
6714 		 * If the rwnd collapsed on
6715 		 * the one we are retransmitting
6716 		 * it does not count against the
6717 		 * rxt count.
6718 		 */
6719 		tp->t_rxtshift++;
6720 	}
6721 	if (tp->t_rxtshift > TCP_MAXRXTSHIFT) {
6722 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
6723 drop_it:
6724 		tp->t_rxtshift = TCP_MAXRXTSHIFT;
6725 		KMOD_TCPSTAT_INC(tcps_timeoutdrop);
6726 		/* XXXGL: previously t_softerror was casted to uint16_t */
6727 		MPASS(tp->t_softerror >= 0);
6728 		retval = tp->t_softerror ? -tp->t_softerror : -ETIMEDOUT;
6729 		goto out;	/* tcp_drop() */
6730 	}
6731 	if (tp->t_state == TCPS_SYN_SENT) {
6732 		/*
6733 		 * If the SYN was retransmitted, indicate CWND to be limited
6734 		 * to 1 segment in cc_conn_init().
6735 		 */
6736 		tp->snd_cwnd = 1;
6737 	} else if (tp->t_rxtshift == 1) {
6738 		/*
6739 		 * first retransmit; record ssthresh and cwnd so they can be
6740 		 * recovered if this turns out to be a "bad" retransmit. A
6741 		 * retransmit is considered "bad" if an ACK for this segment
6742 		 * is received within RTT/2 interval; the assumption here is
6743 		 * that the ACK was already in flight.  See "On Estimating
6744 		 * End-to-End Network Path Properties" by Allman and Paxson
6745 		 * for more details.
6746 		 */
6747 		tp->snd_cwnd_prev = tp->snd_cwnd;
6748 		tp->snd_ssthresh_prev = tp->snd_ssthresh;
6749 		tp->snd_recover_prev = tp->snd_recover;
6750 		tp->t_badrxtwin = ticks + (USEC_2_TICKS(tp->t_srtt)/2);
6751 		tp->t_flags |= TF_PREVVALID;
6752 	} else if ((tp->t_flags & TF_RCVD_TSTMP) == 0)
6753 		tp->t_flags &= ~TF_PREVVALID;
6754 	KMOD_TCPSTAT_INC(tcps_rexmttimeo);
6755 	if ((tp->t_state == TCPS_SYN_SENT) ||
6756 	    (tp->t_state == TCPS_SYN_RECEIVED))
6757 		rexmt = RACK_INITIAL_RTO * tcp_backoff[tp->t_rxtshift];
6758 	else
6759 		rexmt = max(rack_rto_min, (tp->t_srtt + (tp->t_rttvar << 2))) * tcp_backoff[tp->t_rxtshift];
6760 
6761 	RACK_TCPT_RANGESET(tp->t_rxtcur, rexmt,
6762 	   max(rack_rto_min, rexmt), rack_rto_max, rack->r_ctl.timer_slop);
6763 	/*
6764 	 * We enter the path for PLMTUD if connection is established or, if
6765 	 * connection is FIN_WAIT_1 status, reason for the last is that if
6766 	 * amount of data we send is very small, we could send it in couple
6767 	 * of packets and process straight to FIN. In that case we won't
6768 	 * catch ESTABLISHED state.
6769 	 */
6770 #ifdef INET6
6771 	isipv6 = (inp->inp_vflag & INP_IPV6) ? true : false;
6772 #else
6773 	isipv6 = false;
6774 #endif
6775 	if (((V_tcp_pmtud_blackhole_detect == 1) ||
6776 	    (V_tcp_pmtud_blackhole_detect == 2 && !isipv6) ||
6777 	    (V_tcp_pmtud_blackhole_detect == 3 && isipv6)) &&
6778 	    ((tp->t_state == TCPS_ESTABLISHED) ||
6779 	    (tp->t_state == TCPS_FIN_WAIT_1))) {
6780 		/*
6781 		 * Idea here is that at each stage of mtu probe (usually,
6782 		 * 1448 -> 1188 -> 524) should be given 2 chances to recover
6783 		 * before further clamping down. 'tp->t_rxtshift % 2 == 0'
6784 		 * should take care of that.
6785 		 */
6786 		if (((tp->t_flags2 & (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) ==
6787 		    (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) &&
6788 		    (tp->t_rxtshift >= 2 && tp->t_rxtshift < 6 &&
6789 		    tp->t_rxtshift % 2 == 0)) {
6790 			/*
6791 			 * Enter Path MTU Black-hole Detection mechanism: -
6792 			 * Disable Path MTU Discovery (IP "DF" bit). -
6793 			 * Reduce MTU to lower value than what we negotiated
6794 			 * with peer.
6795 			 */
6796 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) == 0) {
6797 				/* Record that we may have found a black hole. */
6798 				tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE;
6799 				/* Keep track of previous MSS. */
6800 				tp->t_pmtud_saved_maxseg = tp->t_maxseg;
6801 			}
6802 
6803 			/*
6804 			 * Reduce the MSS to blackhole value or to the
6805 			 * default in an attempt to retransmit.
6806 			 */
6807 #ifdef INET6
6808 			if (isipv6 &&
6809 			    tp->t_maxseg > V_tcp_v6pmtud_blackhole_mss) {
6810 				/* Use the sysctl tuneable blackhole MSS. */
6811 				tp->t_maxseg = V_tcp_v6pmtud_blackhole_mss;
6812 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
6813 			} else if (isipv6) {
6814 				/* Use the default MSS. */
6815 				tp->t_maxseg = V_tcp_v6mssdflt;
6816 				/*
6817 				 * Disable Path MTU Discovery when we switch
6818 				 * to minmss.
6819 				 */
6820 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
6821 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
6822 			}
6823 #endif
6824 #if defined(INET6) && defined(INET)
6825 			else
6826 #endif
6827 #ifdef INET
6828 			if (tp->t_maxseg > V_tcp_pmtud_blackhole_mss) {
6829 				/* Use the sysctl tuneable blackhole MSS. */
6830 				tp->t_maxseg = V_tcp_pmtud_blackhole_mss;
6831 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
6832 			} else {
6833 				/* Use the default MSS. */
6834 				tp->t_maxseg = V_tcp_mssdflt;
6835 				/*
6836 				 * Disable Path MTU Discovery when we switch
6837 				 * to minmss.
6838 				 */
6839 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
6840 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
6841 			}
6842 #endif
6843 		} else {
6844 			/*
6845 			 * If further retransmissions are still unsuccessful
6846 			 * with a lowered MTU, maybe this isn't a blackhole
6847 			 * and we restore the previous MSS and blackhole
6848 			 * detection flags. The limit '6' is determined by
6849 			 * giving each probe stage (1448, 1188, 524) 2
6850 			 * chances to recover.
6851 			 */
6852 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) &&
6853 			    (tp->t_rxtshift >= 6)) {
6854 				tp->t_flags2 |= TF2_PLPMTU_PMTUD;
6855 				tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE;
6856 				tp->t_maxseg = tp->t_pmtud_saved_maxseg;
6857 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_failed);
6858 			}
6859 		}
6860 	}
6861 	/*
6862 	 * Disable RFC1323 and SACK if we haven't got any response to
6863 	 * our third SYN to work-around some broken terminal servers
6864 	 * (most of which have hopefully been retired) that have bad VJ
6865 	 * header compression code which trashes TCP segments containing
6866 	 * unknown-to-them TCP options.
6867 	 */
6868 	if (tcp_rexmit_drop_options && (tp->t_state == TCPS_SYN_SENT) &&
6869 	    (tp->t_rxtshift == 3))
6870 		tp->t_flags &= ~(TF_REQ_SCALE|TF_REQ_TSTMP|TF_SACK_PERMIT);
6871 	/*
6872 	 * If we backed off this far, our srtt estimate is probably bogus.
6873 	 * Clobber it so we'll take the next rtt measurement as our srtt;
6874 	 * move the current srtt into rttvar to keep the current retransmit
6875 	 * times until then.
6876 	 */
6877 	if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
6878 #ifdef INET6
6879 		if ((inp->inp_vflag & INP_IPV6) != 0)
6880 			in6_losing(inp);
6881 		else
6882 #endif
6883 			in_losing(inp);
6884 		tp->t_rttvar += tp->t_srtt;
6885 		tp->t_srtt = 0;
6886 	}
6887 	sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
6888 	tp->snd_recover = tp->snd_max;
6889 	tp->t_flags |= TF_ACKNOW;
6890 	tp->t_rtttime = 0;
6891 	rack_cong_signal(tp, CC_RTO, tp->snd_una, __LINE__);
6892 out:
6893 	return (retval);
6894 }
6895 
6896 static int
6897 rack_process_timers(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t hpts_calling, uint8_t *doing_tlp)
6898 {
6899 	int32_t ret = 0;
6900 	int32_t timers = (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK);
6901 
6902 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
6903 	    (tp->t_flags & TF_GPUTINPROG)) {
6904 		/*
6905 		 * We have a goodput in progress
6906 		 * and we have entered a late state.
6907 		 * Do we have enough data in the sb
6908 		 * to handle the GPUT request?
6909 		 */
6910 		uint32_t bytes;
6911 
6912 		bytes = tp->gput_ack - tp->gput_seq;
6913 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
6914 			bytes += tp->gput_seq - tp->snd_una;
6915 		if (bytes > sbavail(&tptosocket(tp)->so_snd)) {
6916 			/*
6917 			 * There are not enough bytes in the socket
6918 			 * buffer that have been sent to cover this
6919 			 * measurement. Cancel it.
6920 			 */
6921 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
6922 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
6923 						   tp->gput_seq,
6924 						   0, 0, 18, __LINE__, NULL, 0);
6925 			tp->t_flags &= ~TF_GPUTINPROG;
6926 		}
6927 	}
6928 	if (timers == 0) {
6929 		return (0);
6930 	}
6931 	if (tp->t_state == TCPS_LISTEN) {
6932 		/* no timers on listen sockets */
6933 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)
6934 			return (0);
6935 		return (1);
6936 	}
6937 	if ((timers & PACE_TMR_RACK) &&
6938 	    rack->rc_on_min_to) {
6939 		/*
6940 		 * For the rack timer when we
6941 		 * are on a min-timeout (which means rrr_conf = 3)
6942 		 * we don't want to check the timer. It may
6943 		 * be going off for a pace and thats ok we
6944 		 * want to send the retransmit (if its ready).
6945 		 *
6946 		 * If its on a normal rack timer (non-min) then
6947 		 * we will check if its expired.
6948 		 */
6949 		goto skip_time_check;
6950 	}
6951 	if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
6952 		uint32_t left;
6953 
6954 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
6955 			ret = -1;
6956 			rack_log_to_processing(rack, cts, ret, 0);
6957 			return (0);
6958 		}
6959 		if (hpts_calling == 0) {
6960 			/*
6961 			 * A user send or queued mbuf (sack) has called us? We
6962 			 * return 0 and let the pacing guards
6963 			 * deal with it if they should or
6964 			 * should not cause a send.
6965 			 */
6966 			ret = -2;
6967 			rack_log_to_processing(rack, cts, ret, 0);
6968 			return (0);
6969 		}
6970 		/*
6971 		 * Ok our timer went off early and we are not paced false
6972 		 * alarm, go back to sleep.
6973 		 */
6974 		ret = -3;
6975 		left = rack->r_ctl.rc_timer_exp - cts;
6976 		tcp_hpts_insert(tptoinpcb(tp), HPTS_MS_TO_SLOTS(left));
6977 		rack_log_to_processing(rack, cts, ret, left);
6978 		return (1);
6979 	}
6980 skip_time_check:
6981 	rack->rc_tmr_stopped = 0;
6982 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_MASK;
6983 	if (timers & PACE_TMR_DELACK) {
6984 		ret = rack_timeout_delack(tp, rack, cts);
6985 	} else if (timers & PACE_TMR_RACK) {
6986 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
6987 		rack->r_fast_output = 0;
6988 		ret = rack_timeout_rack(tp, rack, cts);
6989 	} else if (timers & PACE_TMR_TLP) {
6990 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
6991 		ret = rack_timeout_tlp(tp, rack, cts, doing_tlp);
6992 	} else if (timers & PACE_TMR_RXT) {
6993 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
6994 		rack->r_fast_output = 0;
6995 		ret = rack_timeout_rxt(tp, rack, cts);
6996 	} else if (timers & PACE_TMR_PERSIT) {
6997 		ret = rack_timeout_persist(tp, rack, cts);
6998 	} else if (timers & PACE_TMR_KEEP) {
6999 		ret = rack_timeout_keepalive(tp, rack, cts);
7000 	}
7001 	rack_log_to_processing(rack, cts, ret, timers);
7002 	return (ret);
7003 }
7004 
7005 static void
7006 rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line)
7007 {
7008 	struct timeval tv;
7009 	uint32_t us_cts, flags_on_entry;
7010 	uint8_t hpts_removed = 0;
7011 
7012 	flags_on_entry = rack->r_ctl.rc_hpts_flags;
7013 	us_cts = tcp_get_usecs(&tv);
7014 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
7015 	    ((TSTMP_GEQ(us_cts, rack->r_ctl.rc_last_output_to)) ||
7016 	     ((tp->snd_max - tp->snd_una) == 0))) {
7017 		tcp_hpts_remove(rack->rc_inp);
7018 		hpts_removed = 1;
7019 		/* If we were not delayed cancel out the flag. */
7020 		if ((tp->snd_max - tp->snd_una) == 0)
7021 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
7022 		rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
7023 	}
7024 	if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
7025 		rack->rc_tmr_stopped = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
7026 		if (tcp_in_hpts(rack->rc_inp) &&
7027 		    ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)) {
7028 			/*
7029 			 * Canceling timer's when we have no output being
7030 			 * paced. We also must remove ourselves from the
7031 			 * hpts.
7032 			 */
7033 			tcp_hpts_remove(rack->rc_inp);
7034 			hpts_removed = 1;
7035 		}
7036 		rack->r_ctl.rc_hpts_flags &= ~(PACE_TMR_MASK);
7037 	}
7038 	if (hpts_removed == 0)
7039 		rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
7040 }
7041 
7042 static int
7043 rack_stopall(struct tcpcb *tp)
7044 {
7045 	struct tcp_rack *rack;
7046 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7047 	rack->t_timers_stopped = 1;
7048 	return (0);
7049 }
7050 
7051 static void
7052 rack_stop_all_timers(struct tcpcb *tp)
7053 {
7054 	struct tcp_rack *rack;
7055 
7056 	/*
7057 	 * Assure no timers are running.
7058 	 */
7059 	if (tcp_timer_active(tp, TT_PERSIST)) {
7060 		/* We enter in persists, set the flag appropriately */
7061 		rack = (struct tcp_rack *)tp->t_fb_ptr;
7062 		rack->rc_in_persist = 1;
7063 	}
7064 }
7065 
7066 static void
7067 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
7068     struct rack_sendmap *rsm, uint64_t ts, uint16_t add_flag)
7069 {
7070 	int32_t idx;
7071 
7072 	rsm->r_rtr_cnt++;
7073 	rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
7074 	rsm->r_dupack = 0;
7075 	if (rsm->r_rtr_cnt > RACK_NUM_OF_RETRANS) {
7076 		rsm->r_rtr_cnt = RACK_NUM_OF_RETRANS;
7077 		rsm->r_flags |= RACK_OVERMAX;
7078 	}
7079 	if ((rsm->r_rtr_cnt > 1) && ((rsm->r_flags & RACK_TLP) == 0)) {
7080 		rack->r_ctl.rc_holes_rxt += (rsm->r_end - rsm->r_start);
7081 		rsm->r_rtr_bytes += (rsm->r_end - rsm->r_start);
7082 	}
7083 	idx = rsm->r_rtr_cnt - 1;
7084 	rsm->r_tim_lastsent[idx] = ts;
7085 	/*
7086 	 * Here we don't add in the len of send, since its already
7087 	 * in snduna <->snd_max.
7088 	 */
7089 	rsm->r_fas = ctf_flight_size(rack->rc_tp,
7090 				     rack->r_ctl.rc_sacked);
7091 	if (rsm->r_flags & RACK_ACKED) {
7092 		/* Problably MTU discovery messing with us */
7093 		rsm->r_flags &= ~RACK_ACKED;
7094 		rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
7095 	}
7096 	if (rsm->r_in_tmap) {
7097 		TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7098 		rsm->r_in_tmap = 0;
7099 	}
7100 	TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7101 	rsm->r_in_tmap = 1;
7102 	/* Take off the must retransmit flag, if its on */
7103 	if (rsm->r_flags & RACK_MUST_RXT) {
7104 		if (rack->r_must_retran)
7105 			rack->r_ctl.rc_out_at_rto -= (rsm->r_end - rsm->r_start);
7106 		if (SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) {
7107 			/*
7108 			 * We have retransmitted all we need. Clear
7109 			 * any must retransmit flags.
7110 			 */
7111 			rack->r_must_retran = 0;
7112 			rack->r_ctl.rc_out_at_rto = 0;
7113 		}
7114 		rsm->r_flags &= ~RACK_MUST_RXT;
7115 	}
7116 	if (rsm->r_flags & RACK_SACK_PASSED) {
7117 		/* We have retransmitted due to the SACK pass */
7118 		rsm->r_flags &= ~RACK_SACK_PASSED;
7119 		rsm->r_flags |= RACK_WAS_SACKPASS;
7120 	}
7121 }
7122 
7123 static uint32_t
7124 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
7125     struct rack_sendmap *rsm, uint64_t ts, int32_t *lenp, uint16_t add_flag)
7126 {
7127 	/*
7128 	 * We (re-)transmitted starting at rsm->r_start for some length
7129 	 * (possibly less than r_end.
7130 	 */
7131 	struct rack_sendmap *nrsm;
7132 #ifdef INVARIANTS
7133 	struct rack_sendmap *insret;
7134 #endif
7135 	uint32_t c_end;
7136 	int32_t len;
7137 
7138 	len = *lenp;
7139 	c_end = rsm->r_start + len;
7140 	if (SEQ_GEQ(c_end, rsm->r_end)) {
7141 		/*
7142 		 * We retransmitted the whole piece or more than the whole
7143 		 * slopping into the next rsm.
7144 		 */
7145 		rack_update_rsm(tp, rack, rsm, ts, add_flag);
7146 		if (c_end == rsm->r_end) {
7147 			*lenp = 0;
7148 			return (0);
7149 		} else {
7150 			int32_t act_len;
7151 
7152 			/* Hangs over the end return whats left */
7153 			act_len = rsm->r_end - rsm->r_start;
7154 			*lenp = (len - act_len);
7155 			return (rsm->r_end);
7156 		}
7157 		/* We don't get out of this block. */
7158 	}
7159 	/*
7160 	 * Here we retransmitted less than the whole thing which means we
7161 	 * have to split this into what was transmitted and what was not.
7162 	 */
7163 	nrsm = rack_alloc_full_limit(rack);
7164 	if (nrsm == NULL) {
7165 		/*
7166 		 * We can't get memory, so lets not proceed.
7167 		 */
7168 		*lenp = 0;
7169 		return (0);
7170 	}
7171 	/*
7172 	 * So here we are going to take the original rsm and make it what we
7173 	 * retransmitted. nrsm will be the tail portion we did not
7174 	 * retransmit. For example say the chunk was 1, 11 (10 bytes). And
7175 	 * we retransmitted 5 bytes i.e. 1, 5. The original piece shrinks to
7176 	 * 1, 6 and the new piece will be 6, 11.
7177 	 */
7178 	rack_clone_rsm(rack, nrsm, rsm, c_end);
7179 	nrsm->r_dupack = 0;
7180 	rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
7181 #ifndef INVARIANTS
7182 	(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
7183 #else
7184 	insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
7185 	if (insret != NULL) {
7186 		panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
7187 		      nrsm, insret, rack, rsm);
7188 	}
7189 #endif
7190 	if (rsm->r_in_tmap) {
7191 		TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7192 		nrsm->r_in_tmap = 1;
7193 	}
7194 	rsm->r_flags &= (~RACK_HAS_FIN);
7195 	rack_update_rsm(tp, rack, rsm, ts, add_flag);
7196 	/* Log a split of rsm into rsm and nrsm */
7197 	rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
7198 	*lenp = 0;
7199 	return (0);
7200 }
7201 
7202 static void
7203 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
7204 		uint32_t seq_out, uint16_t th_flags, int32_t err, uint64_t cts,
7205 		struct rack_sendmap *hintrsm, uint16_t add_flag, struct mbuf *s_mb, uint32_t s_moff, int hw_tls)
7206 {
7207 	struct tcp_rack *rack;
7208 	struct rack_sendmap *rsm, *nrsm, fe;
7209 #ifdef INVARIANTS
7210 	struct rack_sendmap *insret;
7211 #endif
7212 	register uint32_t snd_max, snd_una;
7213 
7214 	/*
7215 	 * Add to the RACK log of packets in flight or retransmitted. If
7216 	 * there is a TS option we will use the TS echoed, if not we will
7217 	 * grab a TS.
7218 	 *
7219 	 * Retransmissions will increment the count and move the ts to its
7220 	 * proper place. Note that if options do not include TS's then we
7221 	 * won't be able to effectively use the ACK for an RTT on a retran.
7222 	 *
7223 	 * Notes about r_start and r_end. Lets consider a send starting at
7224 	 * sequence 1 for 10 bytes. In such an example the r_start would be
7225 	 * 1 (starting sequence) but the r_end would be r_start+len i.e. 11.
7226 	 * This means that r_end is actually the first sequence for the next
7227 	 * slot (11).
7228 	 *
7229 	 */
7230 	/*
7231 	 * If err is set what do we do XXXrrs? should we not add the thing?
7232 	 * -- i.e. return if err != 0 or should we pretend we sent it? --
7233 	 * i.e. proceed with add ** do this for now.
7234 	 */
7235 	INP_WLOCK_ASSERT(tptoinpcb(tp));
7236 	if (err)
7237 		/*
7238 		 * We don't log errors -- we could but snd_max does not
7239 		 * advance in this case either.
7240 		 */
7241 		return;
7242 
7243 	if (th_flags & TH_RST) {
7244 		/*
7245 		 * We don't log resets and we return immediately from
7246 		 * sending
7247 		 */
7248 		return;
7249 	}
7250 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7251 	snd_una = tp->snd_una;
7252 	snd_max = tp->snd_max;
7253 	if (th_flags & (TH_SYN | TH_FIN)) {
7254 		/*
7255 		 * The call to rack_log_output is made before bumping
7256 		 * snd_max. This means we can record one extra byte on a SYN
7257 		 * or FIN if seq_out is adding more on and a FIN is present
7258 		 * (and we are not resending).
7259 		 */
7260 		if ((th_flags & TH_SYN) && (seq_out == tp->iss))
7261 			len++;
7262 		if (th_flags & TH_FIN)
7263 			len++;
7264 		if (SEQ_LT(snd_max, tp->snd_nxt)) {
7265 			/*
7266 			 * The add/update as not been done for the FIN/SYN
7267 			 * yet.
7268 			 */
7269 			snd_max = tp->snd_nxt;
7270 		}
7271 	}
7272 	if (SEQ_LEQ((seq_out + len), snd_una)) {
7273 		/* Are sending an old segment to induce an ack (keep-alive)? */
7274 		return;
7275 	}
7276 	if (SEQ_LT(seq_out, snd_una)) {
7277 		/* huh? should we panic? */
7278 		uint32_t end;
7279 
7280 		end = seq_out + len;
7281 		seq_out = snd_una;
7282 		if (SEQ_GEQ(end, seq_out))
7283 			len = end - seq_out;
7284 		else
7285 			len = 0;
7286 	}
7287 	if (len == 0) {
7288 		/* We don't log zero window probes */
7289 		return;
7290 	}
7291 	if (IN_FASTRECOVERY(tp->t_flags)) {
7292 		rack->r_ctl.rc_prr_out += len;
7293 	}
7294 	/* First question is it a retransmission or new? */
7295 	if (seq_out == snd_max) {
7296 		/* Its new */
7297 again:
7298 		rsm = rack_alloc(rack);
7299 		if (rsm == NULL) {
7300 			/*
7301 			 * Hmm out of memory and the tcb got destroyed while
7302 			 * we tried to wait.
7303 			 */
7304 			return;
7305 		}
7306 		if (th_flags & TH_FIN) {
7307 			rsm->r_flags = RACK_HAS_FIN|add_flag;
7308 		} else {
7309 			rsm->r_flags = add_flag;
7310 		}
7311 		if (hw_tls)
7312 			rsm->r_hw_tls = 1;
7313 		rsm->r_tim_lastsent[0] = cts;
7314 		rsm->r_rtr_cnt = 1;
7315 		rsm->r_rtr_bytes = 0;
7316 		if (th_flags & TH_SYN) {
7317 			/* The data space is one beyond snd_una */
7318 			rsm->r_flags |= RACK_HAS_SYN;
7319 		}
7320 		rsm->r_start = seq_out;
7321 		rsm->r_end = rsm->r_start + len;
7322 		rsm->r_dupack = 0;
7323 		/*
7324 		 * save off the mbuf location that
7325 		 * sndmbuf_noadv returned (which is
7326 		 * where we started copying from)..
7327 		 */
7328 		rsm->m = s_mb;
7329 		rsm->soff = s_moff;
7330 		/*
7331 		 * Here we do add in the len of send, since its not yet
7332 		 * reflected in in snduna <->snd_max
7333 		 */
7334 		rsm->r_fas = (ctf_flight_size(rack->rc_tp,
7335 					      rack->r_ctl.rc_sacked) +
7336 			      (rsm->r_end - rsm->r_start));
7337 		/* rsm->m will be NULL if RACK_HAS_SYN or RACK_HAS_FIN is set */
7338 		if (rsm->m) {
7339 			if (rsm->m->m_len <= rsm->soff) {
7340 				/*
7341 				 * XXXrrs Question, will this happen?
7342 				 *
7343 				 * If sbsndptr is set at the correct place
7344 				 * then s_moff should always be somewhere
7345 				 * within rsm->m. But if the sbsndptr was
7346 				 * off then that won't be true. If it occurs
7347 				 * we need to walkout to the correct location.
7348 				 */
7349 				struct mbuf *lm;
7350 
7351 				lm = rsm->m;
7352 				while (lm->m_len <= rsm->soff) {
7353 					rsm->soff -= lm->m_len;
7354 					lm = lm->m_next;
7355 					KASSERT(lm != NULL, ("%s rack:%p lm goes null orig_off:%u origmb:%p rsm->soff:%u",
7356 							     __func__, rack, s_moff, s_mb, rsm->soff));
7357 				}
7358 				rsm->m = lm;
7359 			}
7360 			rsm->orig_m_len = rsm->m->m_len;
7361 		} else
7362 			rsm->orig_m_len = 0;
7363 		rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
7364 		/* Log a new rsm */
7365 		rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_NEW, 0, __LINE__);
7366 #ifndef INVARIANTS
7367 		(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
7368 #else
7369 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
7370 		if (insret != NULL) {
7371 			panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
7372 			      nrsm, insret, rack, rsm);
7373 		}
7374 #endif
7375 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7376 		rsm->r_in_tmap = 1;
7377 		/*
7378 		 * Special case detection, is there just a single
7379 		 * packet outstanding when we are not in recovery?
7380 		 *
7381 		 * If this is true mark it so.
7382 		 */
7383 		if ((IN_FASTRECOVERY(tp->t_flags) == 0) &&
7384 		    (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) == ctf_fixed_maxseg(tp))) {
7385 			struct rack_sendmap *prsm;
7386 
7387 			prsm = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
7388 			if (prsm)
7389 				prsm->r_one_out_nr = 1;
7390 		}
7391 		return;
7392 	}
7393 	/*
7394 	 * If we reach here its a retransmission and we need to find it.
7395 	 */
7396 	memset(&fe, 0, sizeof(fe));
7397 more:
7398 	if (hintrsm && (hintrsm->r_start == seq_out)) {
7399 		rsm = hintrsm;
7400 		hintrsm = NULL;
7401 	} else {
7402 		/* No hints sorry */
7403 		rsm = NULL;
7404 	}
7405 	if ((rsm) && (rsm->r_start == seq_out)) {
7406 		seq_out = rack_update_entry(tp, rack, rsm, cts, &len, add_flag);
7407 		if (len == 0) {
7408 			return;
7409 		} else {
7410 			goto more;
7411 		}
7412 	}
7413 	/* Ok it was not the last pointer go through it the hard way. */
7414 refind:
7415 	fe.r_start = seq_out;
7416 	rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
7417 	if (rsm) {
7418 		if (rsm->r_start == seq_out) {
7419 			seq_out = rack_update_entry(tp, rack, rsm, cts, &len, add_flag);
7420 			if (len == 0) {
7421 				return;
7422 			} else {
7423 				goto refind;
7424 			}
7425 		}
7426 		if (SEQ_GEQ(seq_out, rsm->r_start) && SEQ_LT(seq_out, rsm->r_end)) {
7427 			/* Transmitted within this piece */
7428 			/*
7429 			 * Ok we must split off the front and then let the
7430 			 * update do the rest
7431 			 */
7432 			nrsm = rack_alloc_full_limit(rack);
7433 			if (nrsm == NULL) {
7434 				rack_update_rsm(tp, rack, rsm, cts, add_flag);
7435 				return;
7436 			}
7437 			/*
7438 			 * copy rsm to nrsm and then trim the front of rsm
7439 			 * to not include this part.
7440 			 */
7441 			rack_clone_rsm(rack, nrsm, rsm, seq_out);
7442 			rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
7443 #ifndef INVARIANTS
7444 			(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
7445 #else
7446 			insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
7447 			if (insret != NULL) {
7448 				panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
7449 				      nrsm, insret, rack, rsm);
7450 			}
7451 #endif
7452 			if (rsm->r_in_tmap) {
7453 				TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7454 				nrsm->r_in_tmap = 1;
7455 			}
7456 			rsm->r_flags &= (~RACK_HAS_FIN);
7457 			seq_out = rack_update_entry(tp, rack, nrsm, cts, &len, add_flag);
7458 			if (len == 0) {
7459 				return;
7460 			} else if (len > 0)
7461 				goto refind;
7462 		}
7463 	}
7464 	/*
7465 	 * Hmm not found in map did they retransmit both old and on into the
7466 	 * new?
7467 	 */
7468 	if (seq_out == tp->snd_max) {
7469 		goto again;
7470 	} else if (SEQ_LT(seq_out, tp->snd_max)) {
7471 #ifdef INVARIANTS
7472 		printf("seq_out:%u len:%d snd_una:%u snd_max:%u -- but rsm not found?\n",
7473 		       seq_out, len, tp->snd_una, tp->snd_max);
7474 		printf("Starting Dump of all rack entries\n");
7475 		RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
7476 			printf("rsm:%p start:%u end:%u\n",
7477 			       rsm, rsm->r_start, rsm->r_end);
7478 		}
7479 		printf("Dump complete\n");
7480 		panic("seq_out not found rack:%p tp:%p",
7481 		      rack, tp);
7482 #endif
7483 	} else {
7484 #ifdef INVARIANTS
7485 		/*
7486 		 * Hmm beyond sndmax? (only if we are using the new rtt-pack
7487 		 * flag)
7488 		 */
7489 		panic("seq_out:%u(%d) is beyond snd_max:%u tp:%p",
7490 		      seq_out, len, tp->snd_max, tp);
7491 #endif
7492 	}
7493 }
7494 
7495 /*
7496  * Record one of the RTT updates from an ack into
7497  * our sample structure.
7498  */
7499 
7500 static void
7501 tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt, uint32_t len, uint32_t us_rtt,
7502 		    int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt)
7503 {
7504 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
7505 	    (rack->r_ctl.rack_rs.rs_rtt_lowest > rtt)) {
7506 		rack->r_ctl.rack_rs.rs_rtt_lowest = rtt;
7507 	}
7508 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
7509 	    (rack->r_ctl.rack_rs.rs_rtt_highest < rtt)) {
7510 		rack->r_ctl.rack_rs.rs_rtt_highest = rtt;
7511 	}
7512 	if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
7513 	    if (us_rtt < rack->r_ctl.rc_gp_lowrtt)
7514 		rack->r_ctl.rc_gp_lowrtt = us_rtt;
7515 	    if (rack->rc_tp->snd_wnd > rack->r_ctl.rc_gp_high_rwnd)
7516 		    rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
7517 	}
7518 	if ((confidence == 1) &&
7519 	    ((rsm == NULL) ||
7520 	     (rsm->r_just_ret) ||
7521 	     (rsm->r_one_out_nr &&
7522 	      len < (ctf_fixed_maxseg(rack->rc_tp) * 2)))) {
7523 		/*
7524 		 * If the rsm had a just return
7525 		 * hit it then we can't trust the
7526 		 * rtt measurement for buffer deterimination
7527 		 * Note that a confidence of 2, indicates
7528 		 * SACK'd which overrides the r_just_ret or
7529 		 * the r_one_out_nr. If it was a CUM-ACK and
7530 		 * we had only two outstanding, but get an
7531 		 * ack for only 1. Then that also lowers our
7532 		 * confidence.
7533 		 */
7534 		confidence = 0;
7535 	}
7536 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
7537 	    (rack->r_ctl.rack_rs.rs_us_rtt > us_rtt)) {
7538 		if (rack->r_ctl.rack_rs.confidence == 0) {
7539 			/*
7540 			 * We take anything with no current confidence
7541 			 * saved.
7542 			 */
7543 			rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
7544 			rack->r_ctl.rack_rs.confidence = confidence;
7545 			rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
7546 		} else if (confidence || rack->r_ctl.rack_rs.confidence) {
7547 			/*
7548 			 * Once we have a confident number,
7549 			 * we can update it with a smaller
7550 			 * value since this confident number
7551 			 * may include the DSACK time until
7552 			 * the next segment (the second one) arrived.
7553 			 */
7554 			rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
7555 			rack->r_ctl.rack_rs.confidence = confidence;
7556 			rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
7557 		}
7558 	}
7559 	rack_log_rtt_upd(rack->rc_tp, rack, us_rtt, len, rsm, confidence);
7560 	rack->r_ctl.rack_rs.rs_flags = RACK_RTT_VALID;
7561 	rack->r_ctl.rack_rs.rs_rtt_tot += rtt;
7562 	rack->r_ctl.rack_rs.rs_rtt_cnt++;
7563 }
7564 
7565 /*
7566  * Collect new round-trip time estimate
7567  * and update averages and current timeout.
7568  */
7569 static void
7570 tcp_rack_xmit_timer_commit(struct tcp_rack *rack, struct tcpcb *tp)
7571 {
7572 	int32_t delta;
7573 	int32_t rtt;
7574 
7575 	if (rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY)
7576 		/* No valid sample */
7577 		return;
7578 	if (rack->r_ctl.rc_rate_sample_method == USE_RTT_LOW) {
7579 		/* We are to use the lowest RTT seen in a single ack */
7580 		rtt = rack->r_ctl.rack_rs.rs_rtt_lowest;
7581 	} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_HIGH) {
7582 		/* We are to use the highest RTT seen in a single ack */
7583 		rtt = rack->r_ctl.rack_rs.rs_rtt_highest;
7584 	} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_AVG) {
7585 		/* We are to use the average RTT seen in a single ack */
7586 		rtt = (int32_t)(rack->r_ctl.rack_rs.rs_rtt_tot /
7587 				(uint64_t)rack->r_ctl.rack_rs.rs_rtt_cnt);
7588 	} else {
7589 #ifdef INVARIANTS
7590 		panic("Unknown rtt variant %d", rack->r_ctl.rc_rate_sample_method);
7591 #endif
7592 		return;
7593 	}
7594 	if (rtt == 0)
7595 		rtt = 1;
7596 	if (rack->rc_gp_rtt_set == 0) {
7597 		/*
7598 		 * With no RTT we have to accept
7599 		 * even one we are not confident of.
7600 		 */
7601 		rack->r_ctl.rc_gp_srtt = rack->r_ctl.rack_rs.rs_us_rtt;
7602 		rack->rc_gp_rtt_set = 1;
7603 	} else if (rack->r_ctl.rack_rs.confidence) {
7604 		/* update the running gp srtt */
7605 		rack->r_ctl.rc_gp_srtt -= (rack->r_ctl.rc_gp_srtt/8);
7606 		rack->r_ctl.rc_gp_srtt += rack->r_ctl.rack_rs.rs_us_rtt / 8;
7607 	}
7608 	if (rack->r_ctl.rack_rs.confidence) {
7609 		/*
7610 		 * record the low and high for highly buffered path computation,
7611 		 * we only do this if we are confident (not a retransmission).
7612 		 */
7613 		if (rack->r_ctl.rc_highest_us_rtt < rack->r_ctl.rack_rs.rs_us_rtt) {
7614 			rack->r_ctl.rc_highest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
7615 		}
7616 		if (rack->rc_highly_buffered == 0) {
7617 			/*
7618 			 * Currently once we declare a path has
7619 			 * highly buffered there is no going
7620 			 * back, which may be a problem...
7621 			 */
7622 			if ((rack->r_ctl.rc_highest_us_rtt / rack->r_ctl.rc_lowest_us_rtt) > rack_hbp_thresh) {
7623 				rack_log_rtt_shrinks(rack, rack->r_ctl.rack_rs.rs_us_rtt,
7624 						     rack->r_ctl.rc_highest_us_rtt,
7625 						     rack->r_ctl.rc_lowest_us_rtt,
7626 						     RACK_RTTS_SEEHBP);
7627 				rack->rc_highly_buffered = 1;
7628 			}
7629 		}
7630 	}
7631 	if ((rack->r_ctl.rack_rs.confidence) ||
7632 	    (rack->r_ctl.rack_rs.rs_us_rtrcnt == 1)) {
7633 		/*
7634 		 * If we are highly confident of it <or> it was
7635 		 * never retransmitted we accept it as the last us_rtt.
7636 		 */
7637 		rack->r_ctl.rc_last_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
7638 		/* The lowest rtt can be set if its was not retransmited */
7639 		if (rack->r_ctl.rc_lowest_us_rtt > rack->r_ctl.rack_rs.rs_us_rtt) {
7640 			rack->r_ctl.rc_lowest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
7641 			if (rack->r_ctl.rc_lowest_us_rtt == 0)
7642 				rack->r_ctl.rc_lowest_us_rtt = 1;
7643 		}
7644 	}
7645 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7646 	if (tp->t_srtt != 0) {
7647 		/*
7648 		 * We keep a simple srtt in microseconds, like our rtt
7649 		 * measurement. We don't need to do any tricks with shifting
7650 		 * etc. Instead we just add in 1/8th of the new measurement
7651 		 * and subtract out 1/8 of the old srtt. We do the same with
7652 		 * the variance after finding the absolute value of the
7653 		 * difference between this sample and the current srtt.
7654 		 */
7655 		delta = tp->t_srtt - rtt;
7656 		/* Take off 1/8th of the current sRTT */
7657 		tp->t_srtt -= (tp->t_srtt >> 3);
7658 		/* Add in 1/8th of the new RTT just measured */
7659 		tp->t_srtt += (rtt >> 3);
7660 		if (tp->t_srtt <= 0)
7661 			tp->t_srtt = 1;
7662 		/* Now lets make the absolute value of the variance */
7663 		if (delta < 0)
7664 			delta = -delta;
7665 		/* Subtract out 1/8th */
7666 		tp->t_rttvar -= (tp->t_rttvar >> 3);
7667 		/* Add in 1/8th of the new variance we just saw */
7668 		tp->t_rttvar += (delta >> 3);
7669 		if (tp->t_rttvar <= 0)
7670 			tp->t_rttvar = 1;
7671 	} else {
7672 		/*
7673 		 * No rtt measurement yet - use the unsmoothed rtt. Set the
7674 		 * variance to half the rtt (so our first retransmit happens
7675 		 * at 3*rtt).
7676 		 */
7677 		tp->t_srtt = rtt;
7678 		tp->t_rttvar = rtt >> 1;
7679 	}
7680 	rack->rc_srtt_measure_made = 1;
7681 	KMOD_TCPSTAT_INC(tcps_rttupdated);
7682 	tp->t_rttupdated++;
7683 #ifdef STATS
7684 	if (rack_stats_gets_ms_rtt == 0) {
7685 		/* Send in the microsecond rtt used for rxt timeout purposes */
7686 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rtt));
7687 	} else if (rack_stats_gets_ms_rtt == 1) {
7688 		/* Send in the millisecond rtt used for rxt timeout purposes */
7689 		int32_t ms_rtt;
7690 
7691 		/* Round up */
7692 		ms_rtt = (rtt + HPTS_USEC_IN_MSEC - 1) / HPTS_USEC_IN_MSEC;
7693 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, ms_rtt));
7694 	} else if (rack_stats_gets_ms_rtt == 2) {
7695 		/* Send in the millisecond rtt has close to the path RTT as we can get  */
7696 		int32_t ms_rtt;
7697 
7698 		/* Round up */
7699 		ms_rtt = (rack->r_ctl.rack_rs.rs_us_rtt + HPTS_USEC_IN_MSEC - 1) / HPTS_USEC_IN_MSEC;
7700 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, ms_rtt));
7701 	}  else {
7702 		/* Send in the microsecond rtt has close to the path RTT as we can get  */
7703 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rack->r_ctl.rack_rs.rs_us_rtt));
7704 	}
7705 
7706 #endif
7707 	/*
7708 	 * the retransmit should happen at rtt + 4 * rttvar. Because of the
7709 	 * way we do the smoothing, srtt and rttvar will each average +1/2
7710 	 * tick of bias.  When we compute the retransmit timer, we want 1/2
7711 	 * tick of rounding and 1 extra tick because of +-1/2 tick
7712 	 * uncertainty in the firing of the timer.  The bias will give us
7713 	 * exactly the 1.5 tick we need.  But, because the bias is
7714 	 * statistical, we have to test that we don't drop below the minimum
7715 	 * feasible timer (which is 2 ticks).
7716 	 */
7717 	tp->t_rxtshift = 0;
7718 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
7719 		      max(rack_rto_min, rtt + 2), rack_rto_max, rack->r_ctl.timer_slop);
7720 	rack_log_rtt_sample(rack, rtt);
7721 	tp->t_softerror = 0;
7722 }
7723 
7724 
7725 static void
7726 rack_apply_updated_usrtt(struct tcp_rack *rack, uint32_t us_rtt, uint32_t us_cts)
7727 {
7728 	/*
7729 	 * Apply to filter the inbound us-rtt at us_cts.
7730 	 */
7731 	uint32_t old_rtt;
7732 
7733 	old_rtt = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
7734 	apply_filter_min_small(&rack->r_ctl.rc_gp_min_rtt,
7735 			       us_rtt, us_cts);
7736 	if (old_rtt > us_rtt) {
7737 		/* We just hit a new lower rtt time */
7738 		rack_log_rtt_shrinks(rack,  us_cts,  old_rtt,
7739 				     __LINE__, RACK_RTTS_NEWRTT);
7740 		/*
7741 		 * Only count it if its lower than what we saw within our
7742 		 * calculated range.
7743 		 */
7744 		if ((old_rtt - us_rtt) > rack_min_rtt_movement) {
7745 			if (rack_probertt_lower_within &&
7746 			    rack->rc_gp_dyn_mul &&
7747 			    (rack->use_fixed_rate == 0) &&
7748 			    (rack->rc_always_pace)) {
7749 				/*
7750 				 * We are seeing a new lower rtt very close
7751 				 * to the time that we would have entered probe-rtt.
7752 				 * This is probably due to the fact that a peer flow
7753 				 * has entered probe-rtt. Lets go in now too.
7754 				 */
7755 				uint32_t val;
7756 
7757 				val = rack_probertt_lower_within * rack_time_between_probertt;
7758 				val /= 100;
7759 				if ((rack->in_probe_rtt == 0)  &&
7760 				    ((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= (rack_time_between_probertt - val)))	{
7761 					rack_enter_probertt(rack, us_cts);
7762 				}
7763 			}
7764 			rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
7765 		}
7766 	}
7767 }
7768 
7769 static int
7770 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
7771     struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack)
7772 {
7773 	uint32_t us_rtt;
7774 	int32_t i, all;
7775 	uint32_t t, len_acked;
7776 
7777 	if ((rsm->r_flags & RACK_ACKED) ||
7778 	    (rsm->r_flags & RACK_WAS_ACKED))
7779 		/* Already done */
7780 		return (0);
7781 	if (rsm->r_no_rtt_allowed) {
7782 		/* Not allowed */
7783 		return (0);
7784 	}
7785 	if (ack_type == CUM_ACKED) {
7786 		if (SEQ_GT(th_ack, rsm->r_end)) {
7787 			len_acked = rsm->r_end - rsm->r_start;
7788 			all = 1;
7789 		} else {
7790 			len_acked = th_ack - rsm->r_start;
7791 			all = 0;
7792 		}
7793 	} else {
7794 		len_acked = rsm->r_end - rsm->r_start;
7795 		all = 0;
7796 	}
7797 	if (rsm->r_rtr_cnt == 1) {
7798 
7799 		t = cts - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
7800 		if ((int)t <= 0)
7801 			t = 1;
7802 		if (!tp->t_rttlow || tp->t_rttlow > t)
7803 			tp->t_rttlow = t;
7804 		if (!rack->r_ctl.rc_rack_min_rtt ||
7805 		    SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
7806 			rack->r_ctl.rc_rack_min_rtt = t;
7807 			if (rack->r_ctl.rc_rack_min_rtt == 0) {
7808 				rack->r_ctl.rc_rack_min_rtt = 1;
7809 			}
7810 		}
7811 		if (TSTMP_GT(tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time), rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]))
7812 			us_rtt = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
7813 		else
7814 			us_rtt = tcp_get_usecs(NULL) - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
7815 		if (us_rtt == 0)
7816 			us_rtt = 1;
7817 		if (CC_ALGO(tp)->rttsample != NULL) {
7818 			/* Kick the RTT to the CC */
7819 			CC_ALGO(tp)->rttsample(&tp->t_ccv, us_rtt, 1, rsm->r_fas);
7820 		}
7821 		rack_apply_updated_usrtt(rack, us_rtt, tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time));
7822 		if (ack_type == SACKED) {
7823 			rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)], cts, 1);
7824 			tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt, 2 , rsm, rsm->r_rtr_cnt);
7825 		} else {
7826 			/*
7827 			 * We need to setup what our confidence
7828 			 * is in this ack.
7829 			 *
7830 			 * If the rsm was app limited and it is
7831 			 * less than a mss in length (the end
7832 			 * of the send) then we have a gap. If we
7833 			 * were app limited but say we were sending
7834 			 * multiple MSS's then we are more confident
7835 			 * int it.
7836 			 *
7837 			 * When we are not app-limited then we see if
7838 			 * the rsm is being included in the current
7839 			 * measurement, we tell this by the app_limited_needs_set
7840 			 * flag.
7841 			 *
7842 			 * Note that being cwnd blocked is not applimited
7843 			 * as well as the pacing delay between packets which
7844 			 * are sending only 1 or 2 MSS's also will show up
7845 			 * in the RTT. We probably need to examine this algorithm
7846 			 * a bit more and enhance it to account for the delay
7847 			 * between rsm's. We could do that by saving off the
7848 			 * pacing delay of each rsm (in an rsm) and then
7849 			 * factoring that in somehow though for now I am
7850 			 * not sure how :)
7851 			 */
7852 			int calc_conf = 0;
7853 
7854 			if (rsm->r_flags & RACK_APP_LIMITED) {
7855 				if (all && (len_acked <= ctf_fixed_maxseg(tp)))
7856 					calc_conf = 0;
7857 				else
7858 					calc_conf = 1;
7859 			} else if (rack->app_limited_needs_set == 0) {
7860 				calc_conf = 1;
7861 			} else {
7862 				calc_conf = 0;
7863 			}
7864 			rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)], cts, 2);
7865 			tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt,
7866 					    calc_conf, rsm, rsm->r_rtr_cnt);
7867 		}
7868 		if ((rsm->r_flags & RACK_TLP) &&
7869 		    (!IN_FASTRECOVERY(tp->t_flags))) {
7870 			/* Segment was a TLP and our retrans matched */
7871 			if (rack->r_ctl.rc_tlp_cwnd_reduce) {
7872 				rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
7873 			}
7874 		}
7875 		if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)])) {
7876 			/* New more recent rack_tmit_time */
7877 			rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
7878 			rack->rc_rack_rtt = t;
7879 		}
7880 		return (1);
7881 	}
7882 	/*
7883 	 * We clear the soft/rxtshift since we got an ack.
7884 	 * There is no assurance we will call the commit() function
7885 	 * so we need to clear these to avoid incorrect handling.
7886 	 */
7887 	tp->t_rxtshift = 0;
7888 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
7889 		      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
7890 	tp->t_softerror = 0;
7891 	if (to && (to->to_flags & TOF_TS) &&
7892 	    (ack_type == CUM_ACKED) &&
7893 	    (to->to_tsecr) &&
7894 	    ((rsm->r_flags & RACK_OVERMAX) == 0)) {
7895 		/*
7896 		 * Now which timestamp does it match? In this block the ACK
7897 		 * must be coming from a previous transmission.
7898 		 */
7899 		for (i = 0; i < rsm->r_rtr_cnt; i++) {
7900 			if (rack_ts_to_msec(rsm->r_tim_lastsent[i]) == to->to_tsecr) {
7901 				t = cts - (uint32_t)rsm->r_tim_lastsent[i];
7902 				if ((int)t <= 0)
7903 					t = 1;
7904 				if (CC_ALGO(tp)->rttsample != NULL) {
7905 					/*
7906 					 * Kick the RTT to the CC, here
7907 					 * we lie a bit in that we know the
7908 					 * retransmission is correct even though
7909 					 * we retransmitted. This is because
7910 					 * we match the timestamps.
7911 					 */
7912 					if (TSTMP_GT(tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time), rsm->r_tim_lastsent[i]))
7913 						us_rtt = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - (uint32_t)rsm->r_tim_lastsent[i];
7914 					else
7915 						us_rtt = tcp_get_usecs(NULL) - (uint32_t)rsm->r_tim_lastsent[i];
7916 					CC_ALGO(tp)->rttsample(&tp->t_ccv, us_rtt, 1, rsm->r_fas);
7917 				}
7918 				if ((i + 1) < rsm->r_rtr_cnt) {
7919 					/*
7920 					 * The peer ack'd from our previous
7921 					 * transmission. We have a spurious
7922 					 * retransmission and thus we dont
7923 					 * want to update our rack_rtt.
7924 					 *
7925 					 * Hmm should there be a CC revert here?
7926 					 *
7927 					 */
7928 					return (0);
7929 				}
7930 				if (!tp->t_rttlow || tp->t_rttlow > t)
7931 					tp->t_rttlow = t;
7932 				if (!rack->r_ctl.rc_rack_min_rtt || SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
7933 					rack->r_ctl.rc_rack_min_rtt = t;
7934 					if (rack->r_ctl.rc_rack_min_rtt == 0) {
7935 						rack->r_ctl.rc_rack_min_rtt = 1;
7936 					}
7937 				}
7938 				if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
7939 					   (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)])) {
7940 					/* New more recent rack_tmit_time */
7941 					rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
7942 					rack->rc_rack_rtt = t;
7943 				}
7944 				rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[i], cts, 3);
7945 				tcp_rack_xmit_timer(rack, t + 1, len_acked, t, 0, rsm,
7946 						    rsm->r_rtr_cnt);
7947 				return (1);
7948 			}
7949 		}
7950 		goto ts_not_found;
7951 	} else {
7952 		/*
7953 		 * Ok its a SACK block that we retransmitted. or a windows
7954 		 * machine without timestamps. We can tell nothing from the
7955 		 * time-stamp since its not there or the time the peer last
7956 		 * recieved a segment that moved forward its cum-ack point.
7957 		 */
7958 ts_not_found:
7959 		i = rsm->r_rtr_cnt - 1;
7960 		t = cts - (uint32_t)rsm->r_tim_lastsent[i];
7961 		if ((int)t <= 0)
7962 			t = 1;
7963 		if (rack->r_ctl.rc_rack_min_rtt && SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
7964 			/*
7965 			 * We retransmitted and the ack came back in less
7966 			 * than the smallest rtt we have observed. We most
7967 			 * likely did an improper retransmit as outlined in
7968 			 * 6.2 Step 2 point 2 in the rack-draft so we
7969 			 * don't want to update our rack_rtt. We in
7970 			 * theory (in future) might want to think about reverting our
7971 			 * cwnd state but we won't for now.
7972 			 */
7973 			return (0);
7974 		} else if (rack->r_ctl.rc_rack_min_rtt) {
7975 			/*
7976 			 * We retransmitted it and the retransmit did the
7977 			 * job.
7978 			 */
7979 			if (!rack->r_ctl.rc_rack_min_rtt ||
7980 			    SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
7981 				rack->r_ctl.rc_rack_min_rtt = t;
7982 				if (rack->r_ctl.rc_rack_min_rtt == 0) {
7983 					rack->r_ctl.rc_rack_min_rtt = 1;
7984 				}
7985 			}
7986 			if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, (uint32_t)rsm->r_tim_lastsent[i])) {
7987 				/* New more recent rack_tmit_time */
7988 				rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[i];
7989 				rack->rc_rack_rtt = t;
7990 			}
7991 			return (1);
7992 		}
7993 	}
7994 	return (0);
7995 }
7996 
7997 /*
7998  * Mark the SACK_PASSED flag on all entries prior to rsm send wise.
7999  */
8000 static void
8001 rack_log_sack_passed(struct tcpcb *tp,
8002     struct tcp_rack *rack, struct rack_sendmap *rsm)
8003 {
8004 	struct rack_sendmap *nrsm;
8005 
8006 	nrsm = rsm;
8007 	TAILQ_FOREACH_REVERSE_FROM(nrsm, &rack->r_ctl.rc_tmap,
8008 	    rack_head, r_tnext) {
8009 		if (nrsm == rsm) {
8010 			/* Skip orginal segment he is acked */
8011 			continue;
8012 		}
8013 		if (nrsm->r_flags & RACK_ACKED) {
8014 			/*
8015 			 * Skip ack'd segments, though we
8016 			 * should not see these, since tmap
8017 			 * should not have ack'd segments.
8018 			 */
8019 			continue;
8020 		}
8021 		if (nrsm->r_flags & RACK_RWND_COLLAPSED) {
8022 			/*
8023 			 * If the peer dropped the rwnd on
8024 			 * these then we don't worry about them.
8025 			 */
8026 			continue;
8027 		}
8028 		if (nrsm->r_flags & RACK_SACK_PASSED) {
8029 			/*
8030 			 * We found one that is already marked
8031 			 * passed, we have been here before and
8032 			 * so all others below this are marked.
8033 			 */
8034 			break;
8035 		}
8036 		nrsm->r_flags |= RACK_SACK_PASSED;
8037 		nrsm->r_flags &= ~RACK_WAS_SACKPASS;
8038 	}
8039 }
8040 
8041 static void
8042 rack_need_set_test(struct tcpcb *tp,
8043 		   struct tcp_rack *rack,
8044 		   struct rack_sendmap *rsm,
8045 		   tcp_seq th_ack,
8046 		   int line,
8047 		   int use_which)
8048 {
8049 
8050 	if ((tp->t_flags & TF_GPUTINPROG) &&
8051 	    SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
8052 		/*
8053 		 * We were app limited, and this ack
8054 		 * butts up or goes beyond the point where we want
8055 		 * to start our next measurement. We need
8056 		 * to record the new gput_ts as here and
8057 		 * possibly update the start sequence.
8058 		 */
8059 		uint32_t seq, ts;
8060 
8061 		if (rsm->r_rtr_cnt > 1) {
8062 			/*
8063 			 * This is a retransmit, can we
8064 			 * really make any assessment at this
8065 			 * point?  We are not really sure of
8066 			 * the timestamp, is it this or the
8067 			 * previous transmission?
8068 			 *
8069 			 * Lets wait for something better that
8070 			 * is not retransmitted.
8071 			 */
8072 			return;
8073 		}
8074 		seq = tp->gput_seq;
8075 		ts = tp->gput_ts;
8076 		rack->app_limited_needs_set = 0;
8077 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
8078 		/* Do we start at a new end? */
8079 		if ((use_which == RACK_USE_BEG) &&
8080 		    SEQ_GEQ(rsm->r_start, tp->gput_seq)) {
8081 			/*
8082 			 * When we get an ACK that just eats
8083 			 * up some of the rsm, we set RACK_USE_BEG
8084 			 * since whats at r_start (i.e. th_ack)
8085 			 * is left unacked and thats where the
8086 			 * measurement not starts.
8087 			 */
8088 			tp->gput_seq = rsm->r_start;
8089 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8090 		}
8091 		if ((use_which == RACK_USE_END) &&
8092 		    SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
8093 			    /*
8094 			     * We use the end when the cumack
8095 			     * is moving forward and completely
8096 			     * deleting the rsm passed so basically
8097 			     * r_end holds th_ack.
8098 			     *
8099 			     * For SACK's we also want to use the end
8100 			     * since this piece just got sacked and
8101 			     * we want to target anything after that
8102 			     * in our measurement.
8103 			     */
8104 			    tp->gput_seq = rsm->r_end;
8105 			    rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8106 		}
8107 		if (use_which == RACK_USE_END_OR_THACK) {
8108 			/*
8109 			 * special case for ack moving forward,
8110 			 * not a sack, we need to move all the
8111 			 * way up to where this ack cum-ack moves
8112 			 * to.
8113 			 */
8114 			if (SEQ_GT(th_ack, rsm->r_end))
8115 				tp->gput_seq = th_ack;
8116 			else
8117 				tp->gput_seq = rsm->r_end;
8118 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8119 		}
8120 		if (SEQ_GT(tp->gput_seq, tp->gput_ack)) {
8121 			/*
8122 			 * We moved beyond this guy's range, re-calculate
8123 			 * the new end point.
8124 			 */
8125 			if (rack->rc_gp_filled == 0) {
8126 				tp->gput_ack = tp->gput_seq + max(rc_init_window(rack), (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
8127 			} else {
8128 				tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
8129 			}
8130 		}
8131 		/*
8132 		 * We are moving the goal post, we may be able to clear the
8133 		 * measure_saw_probe_rtt flag.
8134 		 */
8135 		if ((rack->in_probe_rtt == 0) &&
8136 		    (rack->measure_saw_probe_rtt) &&
8137 		    (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
8138 			rack->measure_saw_probe_rtt = 0;
8139 		rack_log_pacing_delay_calc(rack, ts, tp->gput_ts,
8140 					   seq, tp->gput_seq, 0, 5, line, NULL, 0);
8141 		if (rack->rc_gp_filled &&
8142 		    ((tp->gput_ack - tp->gput_seq) <
8143 		     max(rc_init_window(rack), (MIN_GP_WIN *
8144 						ctf_fixed_maxseg(tp))))) {
8145 			uint32_t ideal_amount;
8146 
8147 			ideal_amount = rack_get_measure_window(tp, rack);
8148 			if (ideal_amount > sbavail(&tptosocket(tp)->so_snd)) {
8149 				/*
8150 				 * There is no sense of continuing this measurement
8151 				 * because its too small to gain us anything we
8152 				 * trust. Skip it and that way we can start a new
8153 				 * measurement quicker.
8154 				 */
8155 				tp->t_flags &= ~TF_GPUTINPROG;
8156 				rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
8157 							   0, 0, 0, 6, __LINE__, NULL, 0);
8158 			} else {
8159 				/*
8160 				 * Reset the window further out.
8161 				 */
8162 				tp->gput_ack = tp->gput_seq + ideal_amount;
8163 			}
8164 		}
8165 	}
8166 }
8167 
8168 static inline int
8169 is_rsm_inside_declared_tlp_block(struct tcp_rack *rack, struct rack_sendmap *rsm)
8170 {
8171 	if (SEQ_LT(rsm->r_end, rack->r_ctl.last_tlp_acked_start)) {
8172 		/* Behind our TLP definition or right at */
8173 		return (0);
8174 	}
8175 	if (SEQ_GT(rsm->r_start, rack->r_ctl.last_tlp_acked_end)) {
8176 		/* The start is beyond or right at our end of TLP definition */
8177 		return (0);
8178 	}
8179 	/* It has to be a sub-part of the original TLP recorded */
8180 	return (1);
8181 }
8182 
8183 
8184 static uint32_t
8185 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack, struct sackblk *sack,
8186 		   struct tcpopt *to, struct rack_sendmap **prsm, uint32_t cts, int *moved_two)
8187 {
8188 	uint32_t start, end, changed = 0;
8189 	struct rack_sendmap stack_map;
8190 	struct rack_sendmap *rsm, *nrsm, fe, *prev, *next;
8191 #ifdef INVARIANTS
8192 	struct rack_sendmap *insret;
8193 #endif
8194 	int32_t used_ref = 1;
8195 	int moved = 0;
8196 
8197 	start = sack->start;
8198 	end = sack->end;
8199 	rsm = *prsm;
8200 	memset(&fe, 0, sizeof(fe));
8201 do_rest_ofb:
8202 	if ((rsm == NULL) ||
8203 	    (SEQ_LT(end, rsm->r_start)) ||
8204 	    (SEQ_GEQ(start, rsm->r_end)) ||
8205 	    (SEQ_LT(start, rsm->r_start))) {
8206 		/*
8207 		 * We are not in the right spot,
8208 		 * find the correct spot in the tree.
8209 		 */
8210 		used_ref = 0;
8211 		fe.r_start = start;
8212 		rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
8213 		moved++;
8214 	}
8215 	if (rsm == NULL) {
8216 		/* TSNH */
8217 		goto out;
8218 	}
8219 	/* Ok we have an ACK for some piece of this rsm */
8220 	if (rsm->r_start != start) {
8221 		if ((rsm->r_flags & RACK_ACKED) == 0) {
8222 			/*
8223 			 * Before any splitting or hookery is
8224 			 * done is it a TLP of interest i.e. rxt?
8225 			 */
8226 			if ((rsm->r_flags & RACK_TLP) &&
8227 			    (rsm->r_rtr_cnt > 1)) {
8228 				/*
8229 				 * We are splitting a rxt TLP, check
8230 				 * if we need to save off the start/end
8231 				 */
8232 				if (rack->rc_last_tlp_acked_set &&
8233 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8234 					/*
8235 					 * We already turned this on since we are inside
8236 					 * the previous one was a partially sack now we
8237 					 * are getting another one (maybe all of it).
8238 					 *
8239 					 */
8240 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8241 					/*
8242 					 * Lets make sure we have all of it though.
8243 					 */
8244 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8245 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8246 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8247 								     rack->r_ctl.last_tlp_acked_end);
8248 					}
8249 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8250 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8251 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8252 								     rack->r_ctl.last_tlp_acked_end);
8253 					}
8254 				} else {
8255 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8256 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8257 					rack->rc_last_tlp_past_cumack = 0;
8258 					rack->rc_last_tlp_acked_set = 1;
8259 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
8260 				}
8261 			}
8262 			/**
8263 			 * Need to split this in two pieces the before and after,
8264 			 * the before remains in the map, the after must be
8265 			 * added. In other words we have:
8266 			 * rsm        |--------------|
8267 			 * sackblk        |------->
8268 			 * rsm will become
8269 			 *     rsm    |---|
8270 			 * and nrsm will be  the sacked piece
8271 			 *     nrsm       |----------|
8272 			 *
8273 			 * But before we start down that path lets
8274 			 * see if the sack spans over on top of
8275 			 * the next guy and it is already sacked.
8276 			 *
8277 			 */
8278 			next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8279 			if (next && (next->r_flags & RACK_ACKED) &&
8280 			    SEQ_GEQ(end, next->r_start)) {
8281 				/**
8282 				 * So the next one is already acked, and
8283 				 * we can thus by hookery use our stack_map
8284 				 * to reflect the piece being sacked and
8285 				 * then adjust the two tree entries moving
8286 				 * the start and ends around. So we start like:
8287 				 *  rsm     |------------|             (not-acked)
8288 				 *  next                 |-----------| (acked)
8289 				 *  sackblk        |-------->
8290 				 *  We want to end like so:
8291 				 *  rsm     |------|                   (not-acked)
8292 				 *  next           |-----------------| (acked)
8293 				 *  nrsm           |-----|
8294 				 * Where nrsm is a temporary stack piece we
8295 				 * use to update all the gizmos.
8296 				 */
8297 				/* Copy up our fudge block */
8298 				nrsm = &stack_map;
8299 				memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
8300 				/* Now adjust our tree blocks */
8301 				rsm->r_end = start;
8302 				next->r_start = start;
8303 				/* Now we must adjust back where next->m is */
8304 				rack_setup_offset_for_rsm(rsm, next);
8305 
8306 				/* We don't need to adjust rsm, it did not change */
8307 				/* Clear out the dup ack count of the remainder */
8308 				rsm->r_dupack = 0;
8309 				rsm->r_just_ret = 0;
8310 				rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
8311 				/* Now lets make sure our fudge block is right */
8312 				nrsm->r_start = start;
8313 				/* Now lets update all the stats and such */
8314 				rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
8315 				if (rack->app_limited_needs_set)
8316 					rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
8317 				changed += (nrsm->r_end - nrsm->r_start);
8318 				rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
8319 				if (nrsm->r_flags & RACK_SACK_PASSED) {
8320 					rack->r_ctl.rc_reorder_ts = cts;
8321 				}
8322 				/*
8323 				 * Now we want to go up from rsm (the
8324 				 * one left un-acked) to the next one
8325 				 * in the tmap. We do this so when
8326 				 * we walk backwards we include marking
8327 				 * sack-passed on rsm (The one passed in
8328 				 * is skipped since it is generally called
8329 				 * on something sacked before removing it
8330 				 * from the tmap).
8331 				 */
8332 				if (rsm->r_in_tmap) {
8333 					nrsm = TAILQ_NEXT(rsm, r_tnext);
8334 					/*
8335 					 * Now that we have the next
8336 					 * one walk backwards from there.
8337 					 */
8338 					if (nrsm && nrsm->r_in_tmap)
8339 						rack_log_sack_passed(tp, rack, nrsm);
8340 				}
8341 				/* Now are we done? */
8342 				if (SEQ_LT(end, next->r_end) ||
8343 				    (end == next->r_end)) {
8344 					/* Done with block */
8345 					goto out;
8346 				}
8347 				rack_log_map_chg(tp, rack, &stack_map, rsm, next, MAP_SACK_M1, end, __LINE__);
8348 				counter_u64_add(rack_sack_used_next_merge, 1);
8349 				/* Postion for the next block */
8350 				start = next->r_end;
8351 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, next);
8352 				if (rsm == NULL)
8353 					goto out;
8354 			} else {
8355 				/**
8356 				 * We can't use any hookery here, so we
8357 				 * need to split the map. We enter like
8358 				 * so:
8359 				 *  rsm      |--------|
8360 				 *  sackblk       |----->
8361 				 * We will add the new block nrsm and
8362 				 * that will be the new portion, and then
8363 				 * fall through after reseting rsm. So we
8364 				 * split and look like this:
8365 				 *  rsm      |----|
8366 				 *  sackblk       |----->
8367 				 *  nrsm          |---|
8368 				 * We then fall through reseting
8369 				 * rsm to nrsm, so the next block
8370 				 * picks it up.
8371 				 */
8372 				nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
8373 				if (nrsm == NULL) {
8374 					/*
8375 					 * failed XXXrrs what can we do but loose the sack
8376 					 * info?
8377 					 */
8378 					goto out;
8379 				}
8380 				counter_u64_add(rack_sack_splits, 1);
8381 				rack_clone_rsm(rack, nrsm, rsm, start);
8382 				rsm->r_just_ret = 0;
8383 #ifndef INVARIANTS
8384 				(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
8385 #else
8386 				insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
8387 				if (insret != NULL) {
8388 					panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
8389 					      nrsm, insret, rack, rsm);
8390 				}
8391 #endif
8392 				if (rsm->r_in_tmap) {
8393 					TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8394 					nrsm->r_in_tmap = 1;
8395 				}
8396 				rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SACK_M2, end, __LINE__);
8397 				rsm->r_flags &= (~RACK_HAS_FIN);
8398 				/* Position us to point to the new nrsm that starts the sack blk */
8399 				rsm = nrsm;
8400 			}
8401 		} else {
8402 			/* Already sacked this piece */
8403 			counter_u64_add(rack_sack_skipped_acked, 1);
8404 			moved++;
8405 			if (end == rsm->r_end) {
8406 				/* Done with block */
8407 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8408 				goto out;
8409 			} else if (SEQ_LT(end, rsm->r_end)) {
8410 				/* A partial sack to a already sacked block */
8411 				moved++;
8412 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8413 				goto out;
8414 			} else {
8415 				/*
8416 				 * The end goes beyond this guy
8417 				 * reposition the start to the
8418 				 * next block.
8419 				 */
8420 				start = rsm->r_end;
8421 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8422 				if (rsm == NULL)
8423 					goto out;
8424 			}
8425 		}
8426 	}
8427 	if (SEQ_GEQ(end, rsm->r_end)) {
8428 		/**
8429 		 * The end of this block is either beyond this guy or right
8430 		 * at this guy. I.e.:
8431 		 *  rsm ---                 |-----|
8432 		 *  end                     |-----|
8433 		 *  <or>
8434 		 *  end                     |---------|
8435 		 */
8436 		if ((rsm->r_flags & RACK_ACKED) == 0) {
8437 			/*
8438 			 * Is it a TLP of interest?
8439 			 */
8440 			if ((rsm->r_flags & RACK_TLP) &&
8441 			    (rsm->r_rtr_cnt > 1)) {
8442 				/*
8443 				 * We are splitting a rxt TLP, check
8444 				 * if we need to save off the start/end
8445 				 */
8446 				if (rack->rc_last_tlp_acked_set &&
8447 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8448 					/*
8449 					 * We already turned this on since we are inside
8450 					 * the previous one was a partially sack now we
8451 					 * are getting another one (maybe all of it).
8452 					 */
8453 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8454 					/*
8455 					 * Lets make sure we have all of it though.
8456 					 */
8457 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8458 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8459 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8460 								     rack->r_ctl.last_tlp_acked_end);
8461 					}
8462 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8463 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8464 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8465 								     rack->r_ctl.last_tlp_acked_end);
8466 					}
8467 				} else {
8468 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8469 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8470 					rack->rc_last_tlp_past_cumack = 0;
8471 					rack->rc_last_tlp_acked_set = 1;
8472 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
8473 				}
8474 			}
8475 			rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
8476 			changed += (rsm->r_end - rsm->r_start);
8477 			rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
8478 			if (rsm->r_in_tmap) /* should be true */
8479 				rack_log_sack_passed(tp, rack, rsm);
8480 			/* Is Reordering occuring? */
8481 			if (rsm->r_flags & RACK_SACK_PASSED) {
8482 				rsm->r_flags &= ~RACK_SACK_PASSED;
8483 				rack->r_ctl.rc_reorder_ts = cts;
8484 			}
8485 			if (rack->app_limited_needs_set)
8486 				rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
8487 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
8488 			rsm->r_flags |= RACK_ACKED;
8489 			if (rsm->r_in_tmap) {
8490 				TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8491 				rsm->r_in_tmap = 0;
8492 			}
8493 			rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_SACK_M3, end, __LINE__);
8494 		} else {
8495 			counter_u64_add(rack_sack_skipped_acked, 1);
8496 			moved++;
8497 		}
8498 		if (end == rsm->r_end) {
8499 			/* This block only - done, setup for next */
8500 			goto out;
8501 		}
8502 		/*
8503 		 * There is more not coverend by this rsm move on
8504 		 * to the next block in the RB tree.
8505 		 */
8506 		nrsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8507 		start = rsm->r_end;
8508 		rsm = nrsm;
8509 		if (rsm == NULL)
8510 			goto out;
8511 		goto do_rest_ofb;
8512 	}
8513 	/**
8514 	 * The end of this sack block is smaller than
8515 	 * our rsm i.e.:
8516 	 *  rsm ---                 |-----|
8517 	 *  end                     |--|
8518 	 */
8519 	if ((rsm->r_flags & RACK_ACKED) == 0) {
8520 		/*
8521 		 * Is it a TLP of interest?
8522 		 */
8523 		if ((rsm->r_flags & RACK_TLP) &&
8524 		    (rsm->r_rtr_cnt > 1)) {
8525 			/*
8526 			 * We are splitting a rxt TLP, check
8527 			 * if we need to save off the start/end
8528 			 */
8529 			if (rack->rc_last_tlp_acked_set &&
8530 			    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8531 				/*
8532 				 * We already turned this on since we are inside
8533 				 * the previous one was a partially sack now we
8534 				 * are getting another one (maybe all of it).
8535 				 */
8536 				rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8537 				/*
8538 				 * Lets make sure we have all of it though.
8539 				 */
8540 				if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8541 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8542 					rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8543 							     rack->r_ctl.last_tlp_acked_end);
8544 				}
8545 				if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8546 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8547 					rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8548 							     rack->r_ctl.last_tlp_acked_end);
8549 				}
8550 			} else {
8551 				rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8552 				rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8553 				rack->rc_last_tlp_past_cumack = 0;
8554 				rack->rc_last_tlp_acked_set = 1;
8555 				rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
8556 			}
8557 		}
8558 		prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8559 		if (prev &&
8560 		    (prev->r_flags & RACK_ACKED)) {
8561 			/**
8562 			 * Goal, we want the right remainder of rsm to shrink
8563 			 * in place and span from (rsm->r_start = end) to rsm->r_end.
8564 			 * We want to expand prev to go all the way
8565 			 * to prev->r_end <- end.
8566 			 * so in the tree we have before:
8567 			 *   prev     |--------|         (acked)
8568 			 *   rsm               |-------| (non-acked)
8569 			 *   sackblk           |-|
8570 			 * We churn it so we end up with
8571 			 *   prev     |----------|       (acked)
8572 			 *   rsm                 |-----| (non-acked)
8573 			 *   nrsm              |-| (temporary)
8574 			 *
8575 			 * Note if either prev/rsm is a TLP we don't
8576 			 * do this.
8577 			 */
8578 			nrsm = &stack_map;
8579 			memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
8580 			prev->r_end = end;
8581 			rsm->r_start = end;
8582 			/* Now adjust nrsm (stack copy) to be
8583 			 * the one that is the small
8584 			 * piece that was "sacked".
8585 			 */
8586 			nrsm->r_end = end;
8587 			rsm->r_dupack = 0;
8588 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
8589 			/*
8590 			 * Now that the rsm has had its start moved forward
8591 			 * lets go ahead and get its new place in the world.
8592 			 */
8593 			rack_setup_offset_for_rsm(prev, rsm);
8594 			/*
8595 			 * Now nrsm is our new little piece
8596 			 * that is acked (which was merged
8597 			 * to prev). Update the rtt and changed
8598 			 * based on that. Also check for reordering.
8599 			 */
8600 			rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
8601 			if (rack->app_limited_needs_set)
8602 				rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
8603 			changed += (nrsm->r_end - nrsm->r_start);
8604 			rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
8605 			if (nrsm->r_flags & RACK_SACK_PASSED) {
8606 				rack->r_ctl.rc_reorder_ts = cts;
8607 			}
8608 			rack_log_map_chg(tp, rack, prev, &stack_map, rsm, MAP_SACK_M4, end, __LINE__);
8609 			rsm = prev;
8610 			counter_u64_add(rack_sack_used_prev_merge, 1);
8611 		} else {
8612 			/**
8613 			 * This is the case where our previous
8614 			 * block is not acked either, so we must
8615 			 * split the block in two.
8616 			 */
8617 			nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
8618 			if (nrsm == NULL) {
8619 				/* failed rrs what can we do but loose the sack info? */
8620 				goto out;
8621 			}
8622 			if ((rsm->r_flags & RACK_TLP) &&
8623 			    (rsm->r_rtr_cnt > 1)) {
8624 				/*
8625 				 * We are splitting a rxt TLP, check
8626 				 * if we need to save off the start/end
8627 				 */
8628 				if (rack->rc_last_tlp_acked_set &&
8629 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8630 					    /*
8631 					     * We already turned this on since this block is inside
8632 					     * the previous one was a partially sack now we
8633 					     * are getting another one (maybe all of it).
8634 					     */
8635 					    rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8636 					    /*
8637 					     * Lets make sure we have all of it though.
8638 					     */
8639 					    if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8640 						    rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8641 						    rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8642 									 rack->r_ctl.last_tlp_acked_end);
8643 					    }
8644 					    if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8645 						    rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8646 						    rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8647 									 rack->r_ctl.last_tlp_acked_end);
8648 					    }
8649 				    } else {
8650 					    rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8651 					    rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8652 					    rack->rc_last_tlp_acked_set = 1;
8653 					    rack->rc_last_tlp_past_cumack = 0;
8654 					    rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
8655 				    }
8656 			}
8657 			/**
8658 			 * In this case nrsm becomes
8659 			 * nrsm->r_start = end;
8660 			 * nrsm->r_end = rsm->r_end;
8661 			 * which is un-acked.
8662 			 * <and>
8663 			 * rsm->r_end = nrsm->r_start;
8664 			 * i.e. the remaining un-acked
8665 			 * piece is left on the left
8666 			 * hand side.
8667 			 *
8668 			 * So we start like this
8669 			 * rsm      |----------| (not acked)
8670 			 * sackblk  |---|
8671 			 * build it so we have
8672 			 * rsm      |---|         (acked)
8673 			 * nrsm         |------|  (not acked)
8674 			 */
8675 			counter_u64_add(rack_sack_splits, 1);
8676 			rack_clone_rsm(rack, nrsm, rsm, end);
8677 			rsm->r_flags &= (~RACK_HAS_FIN);
8678 			rsm->r_just_ret = 0;
8679 #ifndef INVARIANTS
8680 			(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
8681 #else
8682 			insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
8683 			if (insret != NULL) {
8684 				panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
8685 				      nrsm, insret, rack, rsm);
8686 			}
8687 #endif
8688 			if (rsm->r_in_tmap) {
8689 				TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8690 				nrsm->r_in_tmap = 1;
8691 			}
8692 			nrsm->r_dupack = 0;
8693 			rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
8694 			rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
8695 			changed += (rsm->r_end - rsm->r_start);
8696 			rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
8697 			if (rsm->r_in_tmap) /* should be true */
8698 				rack_log_sack_passed(tp, rack, rsm);
8699 			/* Is Reordering occuring? */
8700 			if (rsm->r_flags & RACK_SACK_PASSED) {
8701 				rsm->r_flags &= ~RACK_SACK_PASSED;
8702 				rack->r_ctl.rc_reorder_ts = cts;
8703 			}
8704 			if (rack->app_limited_needs_set)
8705 				rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
8706 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
8707 			rsm->r_flags |= RACK_ACKED;
8708 			rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SACK_M5, end, __LINE__);
8709 			if (rsm->r_in_tmap) {
8710 				TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8711 				rsm->r_in_tmap = 0;
8712 			}
8713 		}
8714 	} else if (start != end){
8715 		/*
8716 		 * The block was already acked.
8717 		 */
8718 		counter_u64_add(rack_sack_skipped_acked, 1);
8719 		moved++;
8720 	}
8721 out:
8722 	if (rsm &&
8723 	    ((rsm->r_flags & RACK_TLP) == 0) &&
8724 	    (rsm->r_flags & RACK_ACKED)) {
8725 		/*
8726 		 * Now can we merge where we worked
8727 		 * with either the previous or
8728 		 * next block?
8729 		 */
8730 		next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8731 		while (next) {
8732 			if (next->r_flags & RACK_TLP)
8733 				break;
8734 			if (next->r_flags & RACK_ACKED) {
8735 			/* yep this and next can be merged */
8736 				rsm = rack_merge_rsm(rack, rsm, next);
8737 				next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8738 			} else
8739 				break;
8740 		}
8741 		/* Now what about the previous? */
8742 		prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8743 		while (prev) {
8744 			if (prev->r_flags & RACK_TLP)
8745 				break;
8746 			if (prev->r_flags & RACK_ACKED) {
8747 				/* yep the previous and this can be merged */
8748 				rsm = rack_merge_rsm(rack, prev, rsm);
8749 				prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8750 			} else
8751 				break;
8752 		}
8753 	}
8754 	if (used_ref == 0) {
8755 		counter_u64_add(rack_sack_proc_all, 1);
8756 	} else {
8757 		counter_u64_add(rack_sack_proc_short, 1);
8758 	}
8759 	/* Save off the next one for quick reference. */
8760 	if (rsm)
8761 		nrsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8762 	else
8763 		nrsm = NULL;
8764 	*prsm = rack->r_ctl.rc_sacklast = nrsm;
8765 	/* Pass back the moved. */
8766 	*moved_two = moved;
8767 	return (changed);
8768 }
8769 
8770 static void inline
8771 rack_peer_reneges(struct tcp_rack *rack, struct rack_sendmap *rsm, tcp_seq th_ack)
8772 {
8773 	struct rack_sendmap *tmap;
8774 
8775 	tmap = NULL;
8776 	while (rsm && (rsm->r_flags & RACK_ACKED)) {
8777 		/* Its no longer sacked, mark it so */
8778 		rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
8779 #ifdef INVARIANTS
8780 		if (rsm->r_in_tmap) {
8781 			panic("rack:%p rsm:%p flags:0x%x in tmap?",
8782 			      rack, rsm, rsm->r_flags);
8783 		}
8784 #endif
8785 		rsm->r_flags &= ~(RACK_ACKED|RACK_SACK_PASSED|RACK_WAS_SACKPASS);
8786 		/* Rebuild it into our tmap */
8787 		if (tmap == NULL) {
8788 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8789 			tmap = rsm;
8790 		} else {
8791 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, tmap, rsm, r_tnext);
8792 			tmap = rsm;
8793 		}
8794 		tmap->r_in_tmap = 1;
8795 		rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8796 	}
8797 	/*
8798 	 * Now lets possibly clear the sack filter so we start
8799 	 * recognizing sacks that cover this area.
8800 	 */
8801 	sack_filter_clear(&rack->r_ctl.rack_sf, th_ack);
8802 
8803 }
8804 
8805 static void
8806 rack_do_decay(struct tcp_rack *rack)
8807 {
8808 	struct timeval res;
8809 
8810 #define	timersub(tvp, uvp, vvp)						\
8811 	do {								\
8812 		(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;		\
8813 		(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;	\
8814 		if ((vvp)->tv_usec < 0) {				\
8815 			(vvp)->tv_sec--;				\
8816 			(vvp)->tv_usec += 1000000;			\
8817 		}							\
8818 	} while (0)
8819 
8820 	timersub(&rack->r_ctl.act_rcv_time, &rack->r_ctl.rc_last_time_decay, &res);
8821 #undef timersub
8822 
8823 	rack->r_ctl.input_pkt++;
8824 	if ((rack->rc_in_persist) ||
8825 	    (res.tv_sec >= 1) ||
8826 	    (rack->rc_tp->snd_max == rack->rc_tp->snd_una)) {
8827 		/*
8828 		 * Check for decay of non-SAD,
8829 		 * we want all SAD detection metrics to
8830 		 * decay 1/4 per second (or more) passed.
8831 		 */
8832 #ifdef NETFLIX_EXP_DETECTION
8833 		uint32_t pkt_delta;
8834 
8835 		pkt_delta = rack->r_ctl.input_pkt - rack->r_ctl.saved_input_pkt;
8836 #endif
8837 		/* Update our saved tracking values */
8838 		rack->r_ctl.saved_input_pkt = rack->r_ctl.input_pkt;
8839 		rack->r_ctl.rc_last_time_decay = rack->r_ctl.act_rcv_time;
8840 		/* Now do we escape without decay? */
8841 #ifdef NETFLIX_EXP_DETECTION
8842 		if (rack->rc_in_persist ||
8843 		    (rack->rc_tp->snd_max == rack->rc_tp->snd_una) ||
8844 		    (pkt_delta < tcp_sad_low_pps)){
8845 			/*
8846 			 * We don't decay idle connections
8847 			 * or ones that have a low input pps.
8848 			 */
8849 			return;
8850 		}
8851 		/* Decay the counters */
8852 		rack->r_ctl.ack_count = ctf_decay_count(rack->r_ctl.ack_count,
8853 							tcp_sad_decay_val);
8854 		rack->r_ctl.sack_count = ctf_decay_count(rack->r_ctl.sack_count,
8855 							 tcp_sad_decay_val);
8856 		rack->r_ctl.sack_moved_extra = ctf_decay_count(rack->r_ctl.sack_moved_extra,
8857 							       tcp_sad_decay_val);
8858 		rack->r_ctl.sack_noextra_move = ctf_decay_count(rack->r_ctl.sack_noextra_move,
8859 								tcp_sad_decay_val);
8860 #endif
8861 	}
8862 }
8863 
8864 static void
8865 rack_process_to_cumack(struct tcpcb *tp, struct tcp_rack *rack, register uint32_t th_ack, uint32_t cts, struct tcpopt *to)
8866 {
8867 	struct rack_sendmap *rsm;
8868 #ifdef INVARIANTS
8869 	struct rack_sendmap *rm;
8870 #endif
8871 
8872 	/*
8873 	 * The ACK point is advancing to th_ack, we must drop off
8874 	 * the packets in the rack log and calculate any eligble
8875 	 * RTT's.
8876 	 */
8877 	rack->r_wanted_output = 1;
8878 
8879 	/* Tend any TLP that has been marked for 1/2 the seq space (its old)  */
8880 	if ((rack->rc_last_tlp_acked_set == 1)&&
8881 	    (rack->rc_last_tlp_past_cumack == 1) &&
8882 	    (SEQ_GT(rack->r_ctl.last_tlp_acked_start, th_ack))) {
8883 		/*
8884 		 * We have reached the point where our last rack
8885 		 * tlp retransmit sequence is ahead of the cum-ack.
8886 		 * This can only happen when the cum-ack moves all
8887 		 * the way around (its been a full 2^^31+1 bytes
8888 		 * or more since we sent a retransmitted TLP). Lets
8889 		 * turn off the valid flag since its not really valid.
8890 		 *
8891 		 * Note since sack's also turn on this event we have
8892 		 * a complication, we have to wait to age it out until
8893 		 * the cum-ack is by the TLP before checking which is
8894 		 * what the next else clause does.
8895 		 */
8896 		rack_log_dsack_event(rack, 9, __LINE__,
8897 				     rack->r_ctl.last_tlp_acked_start,
8898 				     rack->r_ctl.last_tlp_acked_end);
8899 		rack->rc_last_tlp_acked_set = 0;
8900 		rack->rc_last_tlp_past_cumack = 0;
8901 	} else if ((rack->rc_last_tlp_acked_set == 1) &&
8902 		   (rack->rc_last_tlp_past_cumack == 0) &&
8903 		   (SEQ_GEQ(th_ack, rack->r_ctl.last_tlp_acked_end))) {
8904 		/*
8905 		 * It is safe to start aging TLP's out.
8906 		 */
8907 		rack->rc_last_tlp_past_cumack = 1;
8908 	}
8909 	/* We do the same for the tlp send seq as well */
8910 	if ((rack->rc_last_sent_tlp_seq_valid == 1) &&
8911 	    (rack->rc_last_sent_tlp_past_cumack == 1) &&
8912 	    (SEQ_GT(rack->r_ctl.last_sent_tlp_seq,  th_ack))) {
8913 		rack_log_dsack_event(rack, 9, __LINE__,
8914 				     rack->r_ctl.last_sent_tlp_seq,
8915 				     (rack->r_ctl.last_sent_tlp_seq +
8916 				      rack->r_ctl.last_sent_tlp_len));
8917 		rack->rc_last_sent_tlp_seq_valid = 0;
8918 		rack->rc_last_sent_tlp_past_cumack = 0;
8919 	} else if ((rack->rc_last_sent_tlp_seq_valid == 1) &&
8920 		   (rack->rc_last_sent_tlp_past_cumack == 0) &&
8921 		   (SEQ_GEQ(th_ack, rack->r_ctl.last_sent_tlp_seq))) {
8922 		/*
8923 		 * It is safe to start aging TLP's send.
8924 		 */
8925 		rack->rc_last_sent_tlp_past_cumack = 1;
8926 	}
8927 more:
8928 	rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
8929 	if (rsm == NULL) {
8930 		if ((th_ack - 1) == tp->iss) {
8931 			/*
8932 			 * For the SYN incoming case we will not
8933 			 * have called tcp_output for the sending of
8934 			 * the SYN, so there will be no map. All
8935 			 * other cases should probably be a panic.
8936 			 */
8937 			return;
8938 		}
8939 		if (tp->t_flags & TF_SENTFIN) {
8940 			/* if we sent a FIN we often will not have map */
8941 			return;
8942 		}
8943 #ifdef INVARIANTS
8944 		panic("No rack map tp:%p for state:%d ack:%u rack:%p snd_una:%u snd_max:%u snd_nxt:%u\n",
8945 		      tp,
8946 		      tp->t_state, th_ack, rack,
8947 		      tp->snd_una, tp->snd_max, tp->snd_nxt);
8948 #endif
8949 		return;
8950 	}
8951 	if (SEQ_LT(th_ack, rsm->r_start)) {
8952 		/* Huh map is missing this */
8953 #ifdef INVARIANTS
8954 		printf("Rack map starts at r_start:%u for th_ack:%u huh? ts:%d rs:%d\n",
8955 		       rsm->r_start,
8956 		       th_ack, tp->t_state, rack->r_state);
8957 #endif
8958 		return;
8959 	}
8960 	rack_update_rtt(tp, rack, rsm, to, cts, CUM_ACKED, th_ack);
8961 
8962 	/* Now was it a retransmitted TLP? */
8963 	if ((rsm->r_flags & RACK_TLP) &&
8964 	    (rsm->r_rtr_cnt > 1)) {
8965 		/*
8966 		 * Yes, this rsm was a TLP and retransmitted, remember that
8967 		 * since if a DSACK comes back on this we don't want
8968 		 * to think of it as a reordered segment. This may
8969 		 * get updated again with possibly even other TLPs
8970 		 * in flight, but thats ok. Only when we don't send
8971 		 * a retransmitted TLP for 1/2 the sequences space
8972 		 * will it get turned off (above).
8973 		 */
8974 		if (rack->rc_last_tlp_acked_set &&
8975 		    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8976 			/*
8977 			 * We already turned this on since the end matches,
8978 			 * the previous one was a partially ack now we
8979 			 * are getting another one (maybe all of it).
8980 			 */
8981 			rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8982 			/*
8983 			 * Lets make sure we have all of it though.
8984 			 */
8985 			if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8986 				rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8987 				rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8988 						     rack->r_ctl.last_tlp_acked_end);
8989 			}
8990 			if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8991 				rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8992 				rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8993 						     rack->r_ctl.last_tlp_acked_end);
8994 			}
8995 		} else {
8996 			rack->rc_last_tlp_past_cumack = 1;
8997 			rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8998 			rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8999 			rack->rc_last_tlp_acked_set = 1;
9000 			rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
9001 		}
9002 	}
9003 	/* Now do we consume the whole thing? */
9004 	if (SEQ_GEQ(th_ack, rsm->r_end)) {
9005 		/* Its all consumed. */
9006 		uint32_t left;
9007 		uint8_t newly_acked;
9008 
9009 		rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_FREE, rsm->r_end, __LINE__);
9010 		rack->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
9011 		rsm->r_rtr_bytes = 0;
9012 		/* Record the time of highest cumack sent */
9013 		rack->r_ctl.rc_gp_cumack_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
9014 #ifndef INVARIANTS
9015 		(void)RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
9016 #else
9017 		rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
9018 		if (rm != rsm) {
9019 			panic("removing head in rack:%p rsm:%p rm:%p",
9020 			      rack, rsm, rm);
9021 		}
9022 #endif
9023 		if (rsm->r_in_tmap) {
9024 			TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
9025 			rsm->r_in_tmap = 0;
9026 		}
9027 		newly_acked = 1;
9028 		if (rsm->r_flags & RACK_ACKED) {
9029 			/*
9030 			 * It was acked on the scoreboard -- remove
9031 			 * it from total
9032 			 */
9033 			rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
9034 			newly_acked = 0;
9035 		} else if (rsm->r_flags & RACK_SACK_PASSED) {
9036 			/*
9037 			 * There are segments ACKED on the
9038 			 * scoreboard further up. We are seeing
9039 			 * reordering.
9040 			 */
9041 			rsm->r_flags &= ~RACK_SACK_PASSED;
9042 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
9043 			rsm->r_flags |= RACK_ACKED;
9044 			rack->r_ctl.rc_reorder_ts = cts;
9045 			if (rack->r_ent_rec_ns) {
9046 				/*
9047 				 * We have sent no more, and we saw an sack
9048 				 * then ack arrive.
9049 				 */
9050 				rack->r_might_revert = 1;
9051 			}
9052 		}
9053 		if ((rsm->r_flags & RACK_TO_REXT) &&
9054 		    (tp->t_flags & TF_RCVD_TSTMP) &&
9055 		    (to->to_flags & TOF_TS) &&
9056 		    (to->to_tsecr != 0) &&
9057 		    (tp->t_flags & TF_PREVVALID)) {
9058 			/*
9059 			 * We can use the timestamp to see
9060 			 * if this retransmission was from the
9061 			 * first transmit. If so we made a mistake.
9062 			 */
9063 			tp->t_flags &= ~TF_PREVVALID;
9064 			if (to->to_tsecr == rack_ts_to_msec(rsm->r_tim_lastsent[0])) {
9065 				/* The first transmit is what this ack is for */
9066 				rack_cong_signal(tp, CC_RTO_ERR, th_ack, __LINE__);
9067 			}
9068 		}
9069 		left = th_ack - rsm->r_end;
9070 		if (rack->app_limited_needs_set && newly_acked)
9071 			rack_need_set_test(tp, rack, rsm, th_ack, __LINE__, RACK_USE_END_OR_THACK);
9072 		/* Free back to zone */
9073 		rack_free(rack, rsm);
9074 		if (left) {
9075 			goto more;
9076 		}
9077 		/* Check for reneging */
9078 		rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
9079 		if (rsm && (rsm->r_flags & RACK_ACKED) && (th_ack == rsm->r_start)) {
9080 			/*
9081 			 * The peer has moved snd_una up to
9082 			 * the edge of this send, i.e. one
9083 			 * that it had previously acked. The only
9084 			 * way that can be true if the peer threw
9085 			 * away data (space issues) that it had
9086 			 * previously sacked (else it would have
9087 			 * given us snd_una up to (rsm->r_end).
9088 			 * We need to undo the acked markings here.
9089 			 *
9090 			 * Note we have to look to make sure th_ack is
9091 			 * our rsm->r_start in case we get an old ack
9092 			 * where th_ack is behind snd_una.
9093 			 */
9094 			rack_peer_reneges(rack, rsm, th_ack);
9095 		}
9096 		return;
9097 	}
9098 	if (rsm->r_flags & RACK_ACKED) {
9099 		/*
9100 		 * It was acked on the scoreboard -- remove it from
9101 		 * total for the part being cum-acked.
9102 		 */
9103 		rack->r_ctl.rc_sacked -= (th_ack - rsm->r_start);
9104 	}
9105 	/*
9106 	 * Clear the dup ack count for
9107 	 * the piece that remains.
9108 	 */
9109 	rsm->r_dupack = 0;
9110 	rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
9111 	if (rsm->r_rtr_bytes) {
9112 		/*
9113 		 * It was retransmitted adjust the
9114 		 * sack holes for what was acked.
9115 		 */
9116 		int ack_am;
9117 
9118 		ack_am = (th_ack - rsm->r_start);
9119 		if (ack_am >= rsm->r_rtr_bytes) {
9120 			rack->r_ctl.rc_holes_rxt -= ack_am;
9121 			rsm->r_rtr_bytes -= ack_am;
9122 		}
9123 	}
9124 	/*
9125 	 * Update where the piece starts and record
9126 	 * the time of send of highest cumack sent.
9127 	 */
9128 	rack->r_ctl.rc_gp_cumack_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
9129 	rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_TRIM_HEAD, th_ack, __LINE__);
9130 	/* Now we need to move our offset forward too */
9131 	if (rsm->m && (rsm->orig_m_len != rsm->m->m_len)) {
9132 		/* Fix up the orig_m_len and possibly the mbuf offset */
9133 		rack_adjust_orig_mlen(rsm);
9134 	}
9135 	rsm->soff += (th_ack - rsm->r_start);
9136 	rsm->r_start = th_ack;
9137 	/* Now do we need to move the mbuf fwd too? */
9138 	if (rsm->m) {
9139 		while (rsm->soff >= rsm->m->m_len) {
9140 			rsm->soff -= rsm->m->m_len;
9141 			rsm->m = rsm->m->m_next;
9142 			KASSERT((rsm->m != NULL),
9143 				(" nrsm:%p hit at soff:%u null m",
9144 				 rsm, rsm->soff));
9145 		}
9146 		rsm->orig_m_len = rsm->m->m_len;
9147 	}
9148 	if (rack->app_limited_needs_set)
9149 		rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_BEG);
9150 }
9151 
9152 static void
9153 rack_handle_might_revert(struct tcpcb *tp, struct tcp_rack *rack)
9154 {
9155 	struct rack_sendmap *rsm;
9156 	int sack_pass_fnd = 0;
9157 
9158 	if (rack->r_might_revert) {
9159 		/*
9160 		 * Ok we have reordering, have not sent anything, we
9161 		 * might want to revert the congestion state if nothing
9162 		 * further has SACK_PASSED on it. Lets check.
9163 		 *
9164 		 * We also get here when we have DSACKs come in for
9165 		 * all the data that we FR'd. Note that a rxt or tlp
9166 		 * timer clears this from happening.
9167 		 */
9168 
9169 		TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
9170 			if (rsm->r_flags & RACK_SACK_PASSED) {
9171 				sack_pass_fnd = 1;
9172 				break;
9173 			}
9174 		}
9175 		if (sack_pass_fnd == 0) {
9176 			/*
9177 			 * We went into recovery
9178 			 * incorrectly due to reordering!
9179 			 */
9180 			int orig_cwnd;
9181 
9182 			rack->r_ent_rec_ns = 0;
9183 			orig_cwnd = tp->snd_cwnd;
9184 			tp->snd_ssthresh = rack->r_ctl.rc_ssthresh_at_erec;
9185 			tp->snd_recover = tp->snd_una;
9186 			rack_log_to_prr(rack, 14, orig_cwnd, __LINE__);
9187 			EXIT_RECOVERY(tp->t_flags);
9188 		}
9189 		rack->r_might_revert = 0;
9190 	}
9191 }
9192 
9193 #ifdef NETFLIX_EXP_DETECTION
9194 static void
9195 rack_do_detection(struct tcpcb *tp, struct tcp_rack *rack,  uint32_t bytes_this_ack, uint32_t segsiz)
9196 {
9197 	if ((rack->do_detection || tcp_force_detection) &&
9198 	    tcp_sack_to_ack_thresh &&
9199 	    tcp_sack_to_move_thresh &&
9200 	    ((rack->r_ctl.rc_num_maps_alloced > tcp_map_minimum) || rack->sack_attack_disable)) {
9201 		/*
9202 		 * We have thresholds set to find
9203 		 * possible attackers and disable sack.
9204 		 * Check them.
9205 		 */
9206 		uint64_t ackratio, moveratio, movetotal;
9207 
9208 		/* Log detecting */
9209 		rack_log_sad(rack, 1);
9210 		ackratio = (uint64_t)(rack->r_ctl.sack_count);
9211 		ackratio *= (uint64_t)(1000);
9212 		if (rack->r_ctl.ack_count)
9213 			ackratio /= (uint64_t)(rack->r_ctl.ack_count);
9214 		else {
9215 			/* We really should not hit here */
9216 			ackratio = 1000;
9217 		}
9218 		if ((rack->sack_attack_disable == 0) &&
9219 		    (ackratio > rack_highest_sack_thresh_seen))
9220 			rack_highest_sack_thresh_seen = (uint32_t)ackratio;
9221 		movetotal = rack->r_ctl.sack_moved_extra;
9222 		movetotal += rack->r_ctl.sack_noextra_move;
9223 		moveratio = rack->r_ctl.sack_moved_extra;
9224 		moveratio *= (uint64_t)1000;
9225 		if (movetotal)
9226 			moveratio /= movetotal;
9227 		else {
9228 			/* No moves, thats pretty good */
9229 			moveratio = 0;
9230 		}
9231 		if ((rack->sack_attack_disable == 0) &&
9232 		    (moveratio > rack_highest_move_thresh_seen))
9233 			rack_highest_move_thresh_seen = (uint32_t)moveratio;
9234 		if (rack->sack_attack_disable == 0) {
9235 			if ((ackratio > tcp_sack_to_ack_thresh) &&
9236 			    (moveratio > tcp_sack_to_move_thresh)) {
9237 				/* Disable sack processing */
9238 				rack->sack_attack_disable = 1;
9239 				if (rack->r_rep_attack == 0) {
9240 					rack->r_rep_attack = 1;
9241 					counter_u64_add(rack_sack_attacks_detected, 1);
9242 				}
9243 				if (tcp_attack_on_turns_on_logging) {
9244 					/*
9245 					 * Turn on logging, used for debugging
9246 					 * false positives.
9247 					 */
9248 					rack->rc_tp->t_logstate = tcp_attack_on_turns_on_logging;
9249 				}
9250 				/* Clamp the cwnd at flight size */
9251 				rack->r_ctl.rc_saved_cwnd = rack->rc_tp->snd_cwnd;
9252 				rack->rc_tp->snd_cwnd = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
9253 				rack_log_sad(rack, 2);
9254 			}
9255 		} else {
9256 			/* We are sack-disabled check for false positives */
9257 			if ((ackratio <= tcp_restoral_thresh) ||
9258 			    (rack->r_ctl.rc_num_maps_alloced  < tcp_map_minimum)) {
9259 				rack->sack_attack_disable = 0;
9260 				rack_log_sad(rack, 3);
9261 				/* Restart counting */
9262 				rack->r_ctl.sack_count = 0;
9263 				rack->r_ctl.sack_moved_extra = 0;
9264 				rack->r_ctl.sack_noextra_move = 1;
9265 				rack->r_ctl.ack_count = max(1,
9266 				      (bytes_this_ack / segsiz));
9267 
9268 				if (rack->r_rep_reverse == 0) {
9269 					rack->r_rep_reverse = 1;
9270 					counter_u64_add(rack_sack_attacks_reversed, 1);
9271 				}
9272 				/* Restore the cwnd */
9273 				if (rack->r_ctl.rc_saved_cwnd > rack->rc_tp->snd_cwnd)
9274 					rack->rc_tp->snd_cwnd = rack->r_ctl.rc_saved_cwnd;
9275 			}
9276 		}
9277 	}
9278 }
9279 #endif
9280 
9281 static int
9282 rack_note_dsack(struct tcp_rack *rack, tcp_seq start, tcp_seq end)
9283 {
9284 
9285 	uint32_t am, l_end;
9286 	int was_tlp = 0;
9287 
9288 	if (SEQ_GT(end, start))
9289 		am = end - start;
9290 	else
9291 		am = 0;
9292 	if ((rack->rc_last_tlp_acked_set ) &&
9293 	    (SEQ_GEQ(start, rack->r_ctl.last_tlp_acked_start)) &&
9294 	    (SEQ_LEQ(end, rack->r_ctl.last_tlp_acked_end))) {
9295 		/*
9296 		 * The DSACK is because of a TLP which we don't
9297 		 * do anything with the reordering window over since
9298 		 * it was not reordering that caused the DSACK but
9299 		 * our previous retransmit TLP.
9300 		 */
9301 		rack_log_dsack_event(rack, 7, __LINE__, start, end);
9302 		was_tlp = 1;
9303 		goto skip_dsack_round;
9304 	}
9305 	if (rack->rc_last_sent_tlp_seq_valid) {
9306 		l_end = rack->r_ctl.last_sent_tlp_seq + rack->r_ctl.last_sent_tlp_len;
9307 		if (SEQ_GEQ(start, rack->r_ctl.last_sent_tlp_seq) &&
9308 		    (SEQ_LEQ(end, l_end))) {
9309 			/*
9310 			 * This dsack is from the last sent TLP, ignore it
9311 			 * for reordering purposes.
9312 			 */
9313 			rack_log_dsack_event(rack, 7, __LINE__, start, end);
9314 			was_tlp = 1;
9315 			goto skip_dsack_round;
9316 		}
9317 	}
9318 	if (rack->rc_dsack_round_seen == 0) {
9319 		rack->rc_dsack_round_seen = 1;
9320 		rack->r_ctl.dsack_round_end = rack->rc_tp->snd_max;
9321 		rack->r_ctl.num_dsack++;
9322 		rack->r_ctl.dsack_persist = 16;	/* 16 is from the standard */
9323 		rack_log_dsack_event(rack, 2, __LINE__, 0, 0);
9324 	}
9325 skip_dsack_round:
9326 	/*
9327 	 * We keep track of how many DSACK blocks we get
9328 	 * after a recovery incident.
9329 	 */
9330 	rack->r_ctl.dsack_byte_cnt += am;
9331 	if (!IN_FASTRECOVERY(rack->rc_tp->t_flags) &&
9332 	    rack->r_ctl.retran_during_recovery &&
9333 	    (rack->r_ctl.dsack_byte_cnt >= rack->r_ctl.retran_during_recovery)) {
9334 		/*
9335 		 * False recovery most likely culprit is reordering. If
9336 		 * nothing else is missing we need to revert.
9337 		 */
9338 		rack->r_might_revert = 1;
9339 		rack_handle_might_revert(rack->rc_tp, rack);
9340 		rack->r_might_revert = 0;
9341 		rack->r_ctl.retran_during_recovery = 0;
9342 		rack->r_ctl.dsack_byte_cnt = 0;
9343 	}
9344 	return (was_tlp);
9345 }
9346 
9347 static uint32_t
9348 do_rack_compute_pipe(struct tcpcb *tp, struct tcp_rack *rack, uint32_t snd_una)
9349 {
9350 	return (((tp->snd_max - snd_una) - rack->r_ctl.rc_sacked) + rack->r_ctl.rc_holes_rxt);
9351 }
9352 
9353 static int32_t
9354 rack_compute_pipe(struct tcpcb *tp)
9355 {
9356 	return ((int32_t)do_rack_compute_pipe(tp,
9357 					      (struct tcp_rack *)tp->t_fb_ptr,
9358 					      tp->snd_una));
9359 }
9360 
9361 static void
9362 rack_update_prr(struct tcpcb *tp, struct tcp_rack *rack, uint32_t changed, tcp_seq th_ack)
9363 {
9364 	/* Deal with changed and PRR here (in recovery only) */
9365 	uint32_t pipe, snd_una;
9366 
9367 	rack->r_ctl.rc_prr_delivered += changed;
9368 
9369 	if (sbavail(&rack->rc_inp->inp_socket->so_snd) <= (tp->snd_max - tp->snd_una)) {
9370 		/*
9371 		 * It is all outstanding, we are application limited
9372 		 * and thus we don't need more room to send anything.
9373 		 * Note we use tp->snd_una here and not th_ack because
9374 		 * the data as yet not been cut from the sb.
9375 		 */
9376 		rack->r_ctl.rc_prr_sndcnt = 0;
9377 		return;
9378 	}
9379 	/* Compute prr_sndcnt */
9380 	if (SEQ_GT(tp->snd_una, th_ack)) {
9381 		snd_una = tp->snd_una;
9382 	} else {
9383 		snd_una = th_ack;
9384 	}
9385 	pipe = do_rack_compute_pipe(tp, rack, snd_una);
9386 	if (pipe > tp->snd_ssthresh) {
9387 		long sndcnt;
9388 
9389 		sndcnt = rack->r_ctl.rc_prr_delivered * tp->snd_ssthresh;
9390 		if (rack->r_ctl.rc_prr_recovery_fs > 0)
9391 			sndcnt /= (long)rack->r_ctl.rc_prr_recovery_fs;
9392 		else {
9393 			rack->r_ctl.rc_prr_sndcnt = 0;
9394 			rack_log_to_prr(rack, 9, 0, __LINE__);
9395 			sndcnt = 0;
9396 		}
9397 		sndcnt++;
9398 		if (sndcnt > (long)rack->r_ctl.rc_prr_out)
9399 			sndcnt -= rack->r_ctl.rc_prr_out;
9400 		else
9401 			sndcnt = 0;
9402 		rack->r_ctl.rc_prr_sndcnt = sndcnt;
9403 		rack_log_to_prr(rack, 10, 0, __LINE__);
9404 	} else {
9405 		uint32_t limit;
9406 
9407 		if (rack->r_ctl.rc_prr_delivered > rack->r_ctl.rc_prr_out)
9408 			limit = (rack->r_ctl.rc_prr_delivered - rack->r_ctl.rc_prr_out);
9409 		else
9410 			limit = 0;
9411 		if (changed > limit)
9412 			limit = changed;
9413 		limit += ctf_fixed_maxseg(tp);
9414 		if (tp->snd_ssthresh > pipe) {
9415 			rack->r_ctl.rc_prr_sndcnt = min((tp->snd_ssthresh - pipe), limit);
9416 			rack_log_to_prr(rack, 11, 0, __LINE__);
9417 		} else {
9418 			rack->r_ctl.rc_prr_sndcnt = min(0, limit);
9419 			rack_log_to_prr(rack, 12, 0, __LINE__);
9420 		}
9421 	}
9422 }
9423 
9424 static void
9425 rack_log_ack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th, int entered_recovery, int dup_ack_struck)
9426 {
9427 	uint32_t changed;
9428 	struct tcp_rack *rack;
9429 	struct rack_sendmap *rsm;
9430 	struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1];
9431 	register uint32_t th_ack;
9432 	int32_t i, j, k, num_sack_blks = 0;
9433 	uint32_t cts, acked, ack_point;
9434 	int loop_start = 0, moved_two = 0;
9435 	uint32_t tsused;
9436 
9437 
9438 	INP_WLOCK_ASSERT(tptoinpcb(tp));
9439 	if (tcp_get_flags(th) & TH_RST) {
9440 		/* We don't log resets */
9441 		return;
9442 	}
9443 	rack = (struct tcp_rack *)tp->t_fb_ptr;
9444 	cts = tcp_get_usecs(NULL);
9445 	rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
9446 	changed = 0;
9447 	th_ack = th->th_ack;
9448 	if (rack->sack_attack_disable == 0)
9449 		rack_do_decay(rack);
9450 	if (BYTES_THIS_ACK(tp, th) >= ctf_fixed_maxseg(rack->rc_tp)) {
9451 		/*
9452 		 * You only get credit for
9453 		 * MSS and greater (and you get extra
9454 		 * credit for larger cum-ack moves).
9455 		 */
9456 		int ac;
9457 
9458 		ac = BYTES_THIS_ACK(tp, th) / ctf_fixed_maxseg(rack->rc_tp);
9459 		rack->r_ctl.ack_count += ac;
9460 		counter_u64_add(rack_ack_total, ac);
9461 	}
9462 	if (rack->r_ctl.ack_count > 0xfff00000) {
9463 		/*
9464 		 * reduce the number to keep us under
9465 		 * a uint32_t.
9466 		 */
9467 		rack->r_ctl.ack_count /= 2;
9468 		rack->r_ctl.sack_count /= 2;
9469 	}
9470 	if (SEQ_GT(th_ack, tp->snd_una)) {
9471 		rack_log_progress_event(rack, tp, ticks, PROGRESS_UPDATE, __LINE__);
9472 		tp->t_acktime = ticks;
9473 	}
9474 	if (rsm && SEQ_GT(th_ack, rsm->r_start))
9475 		changed = th_ack - rsm->r_start;
9476 	if (changed) {
9477 		rack_process_to_cumack(tp, rack, th_ack, cts, to);
9478 	}
9479 	if ((to->to_flags & TOF_SACK) == 0) {
9480 		/* We are done nothing left and no sack. */
9481 		rack_handle_might_revert(tp, rack);
9482 		/*
9483 		 * For cases where we struck a dup-ack
9484 		 * with no SACK, add to the changes so
9485 		 * PRR will work right.
9486 		 */
9487 		if (dup_ack_struck && (changed == 0)) {
9488 			changed += ctf_fixed_maxseg(rack->rc_tp);
9489 		}
9490 		goto out;
9491 	}
9492 	/* Sack block processing */
9493 	if (SEQ_GT(th_ack, tp->snd_una))
9494 		ack_point = th_ack;
9495 	else
9496 		ack_point = tp->snd_una;
9497 	for (i = 0; i < to->to_nsacks; i++) {
9498 		bcopy((to->to_sacks + i * TCPOLEN_SACK),
9499 		      &sack, sizeof(sack));
9500 		sack.start = ntohl(sack.start);
9501 		sack.end = ntohl(sack.end);
9502 		if (SEQ_GT(sack.end, sack.start) &&
9503 		    SEQ_GT(sack.start, ack_point) &&
9504 		    SEQ_LT(sack.start, tp->snd_max) &&
9505 		    SEQ_GT(sack.end, ack_point) &&
9506 		    SEQ_LEQ(sack.end, tp->snd_max)) {
9507 			sack_blocks[num_sack_blks] = sack;
9508 			num_sack_blks++;
9509 		} else if (SEQ_LEQ(sack.start, th_ack) &&
9510 			   SEQ_LEQ(sack.end, th_ack)) {
9511 			int was_tlp;
9512 
9513 			was_tlp = rack_note_dsack(rack, sack.start, sack.end);
9514 			/*
9515 			 * Its a D-SACK block.
9516 			 */
9517 			tcp_record_dsack(tp, sack.start, sack.end, was_tlp);
9518 		}
9519 	}
9520 	if (rack->rc_dsack_round_seen) {
9521 		/* Is the dsack roound over? */
9522 		if (SEQ_GEQ(th_ack, rack->r_ctl.dsack_round_end)) {
9523 			/* Yes it is */
9524 			rack->rc_dsack_round_seen = 0;
9525 			rack_log_dsack_event(rack, 3, __LINE__, 0, 0);
9526 		}
9527 	}
9528 	/*
9529 	 * Sort the SACK blocks so we can update the rack scoreboard with
9530 	 * just one pass.
9531 	 */
9532 	num_sack_blks = sack_filter_blks(&rack->r_ctl.rack_sf, sack_blocks,
9533 					 num_sack_blks, th->th_ack);
9534 	ctf_log_sack_filter(rack->rc_tp, num_sack_blks, sack_blocks);
9535 	if (num_sack_blks == 0) {
9536 		/* Nothing to sack (DSACKs?) */
9537 		goto out_with_totals;
9538 	}
9539 	if (num_sack_blks < 2) {
9540 		/* Only one, we don't need to sort */
9541 		goto do_sack_work;
9542 	}
9543 	/* Sort the sacks */
9544 	for (i = 0; i < num_sack_blks; i++) {
9545 		for (j = i + 1; j < num_sack_blks; j++) {
9546 			if (SEQ_GT(sack_blocks[i].end, sack_blocks[j].end)) {
9547 				sack = sack_blocks[i];
9548 				sack_blocks[i] = sack_blocks[j];
9549 				sack_blocks[j] = sack;
9550 			}
9551 		}
9552 	}
9553 	/*
9554 	 * Now are any of the sack block ends the same (yes some
9555 	 * implementations send these)?
9556 	 */
9557 again:
9558 	if (num_sack_blks == 0)
9559 		goto out_with_totals;
9560 	if (num_sack_blks > 1) {
9561 		for (i = 0; i < num_sack_blks; i++) {
9562 			for (j = i + 1; j < num_sack_blks; j++) {
9563 				if (sack_blocks[i].end == sack_blocks[j].end) {
9564 					/*
9565 					 * Ok these two have the same end we
9566 					 * want the smallest end and then
9567 					 * throw away the larger and start
9568 					 * again.
9569 					 */
9570 					if (SEQ_LT(sack_blocks[j].start, sack_blocks[i].start)) {
9571 						/*
9572 						 * The second block covers
9573 						 * more area use that
9574 						 */
9575 						sack_blocks[i].start = sack_blocks[j].start;
9576 					}
9577 					/*
9578 					 * Now collapse out the dup-sack and
9579 					 * lower the count
9580 					 */
9581 					for (k = (j + 1); k < num_sack_blks; k++) {
9582 						sack_blocks[j].start = sack_blocks[k].start;
9583 						sack_blocks[j].end = sack_blocks[k].end;
9584 						j++;
9585 					}
9586 					num_sack_blks--;
9587 					goto again;
9588 				}
9589 			}
9590 		}
9591 	}
9592 do_sack_work:
9593 	/*
9594 	 * First lets look to see if
9595 	 * we have retransmitted and
9596 	 * can use the transmit next?
9597 	 */
9598 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
9599 	if (rsm &&
9600 	    SEQ_GT(sack_blocks[0].end, rsm->r_start) &&
9601 	    SEQ_LT(sack_blocks[0].start, rsm->r_end)) {
9602 		/*
9603 		 * We probably did the FR and the next
9604 		 * SACK in continues as we would expect.
9605 		 */
9606 		acked = rack_proc_sack_blk(tp, rack, &sack_blocks[0], to, &rsm, cts, &moved_two);
9607 		if (acked) {
9608 			rack->r_wanted_output = 1;
9609 			changed += acked;
9610 		}
9611 		if (num_sack_blks == 1) {
9612 			/*
9613 			 * This is what we would expect from
9614 			 * a normal implementation to happen
9615 			 * after we have retransmitted the FR,
9616 			 * i.e the sack-filter pushes down
9617 			 * to 1 block and the next to be retransmitted
9618 			 * is the sequence in the sack block (has more
9619 			 * are acked). Count this as ACK'd data to boost
9620 			 * up the chances of recovering any false positives.
9621 			 */
9622 			rack->r_ctl.ack_count += (acked / ctf_fixed_maxseg(rack->rc_tp));
9623 			counter_u64_add(rack_ack_total, (acked / ctf_fixed_maxseg(rack->rc_tp)));
9624 			counter_u64_add(rack_express_sack, 1);
9625 			if (rack->r_ctl.ack_count > 0xfff00000) {
9626 				/*
9627 				 * reduce the number to keep us under
9628 				 * a uint32_t.
9629 				 */
9630 				rack->r_ctl.ack_count /= 2;
9631 				rack->r_ctl.sack_count /= 2;
9632 			}
9633 			goto out_with_totals;
9634 		} else {
9635 			/*
9636 			 * Start the loop through the
9637 			 * rest of blocks, past the first block.
9638 			 */
9639 			moved_two = 0;
9640 			loop_start = 1;
9641 		}
9642 	}
9643 	/* Its a sack of some sort */
9644 	rack->r_ctl.sack_count++;
9645 	if (rack->r_ctl.sack_count > 0xfff00000) {
9646 		/*
9647 		 * reduce the number to keep us under
9648 		 * a uint32_t.
9649 		 */
9650 		rack->r_ctl.ack_count /= 2;
9651 		rack->r_ctl.sack_count /= 2;
9652 	}
9653 	counter_u64_add(rack_sack_total, 1);
9654 	if (rack->sack_attack_disable) {
9655 		/* An attacker disablement is in place */
9656 		if (num_sack_blks > 1) {
9657 			rack->r_ctl.sack_count += (num_sack_blks - 1);
9658 			rack->r_ctl.sack_moved_extra++;
9659 			counter_u64_add(rack_move_some, 1);
9660 			if (rack->r_ctl.sack_moved_extra > 0xfff00000) {
9661 				rack->r_ctl.sack_moved_extra /= 2;
9662 				rack->r_ctl.sack_noextra_move /= 2;
9663 			}
9664 		}
9665 		goto out;
9666 	}
9667 	rsm = rack->r_ctl.rc_sacklast;
9668 	for (i = loop_start; i < num_sack_blks; i++) {
9669 		acked = rack_proc_sack_blk(tp, rack, &sack_blocks[i], to, &rsm, cts, &moved_two);
9670 		if (acked) {
9671 			rack->r_wanted_output = 1;
9672 			changed += acked;
9673 		}
9674 		if (moved_two) {
9675 			/*
9676 			 * If we did not get a SACK for at least a MSS and
9677 			 * had to move at all, or if we moved more than our
9678 			 * threshold, it counts against the "extra" move.
9679 			 */
9680 			rack->r_ctl.sack_moved_extra += moved_two;
9681 			counter_u64_add(rack_move_some, 1);
9682 		} else {
9683 			/*
9684 			 * else we did not have to move
9685 			 * any more than we would expect.
9686 			 */
9687 			rack->r_ctl.sack_noextra_move++;
9688 			counter_u64_add(rack_move_none, 1);
9689 		}
9690 		if (moved_two && (acked < ctf_fixed_maxseg(rack->rc_tp))) {
9691 			/*
9692 			 * If the SACK was not a full MSS then
9693 			 * we add to sack_count the number of
9694 			 * MSS's (or possibly more than
9695 			 * a MSS if its a TSO send) we had to skip by.
9696 			 */
9697 			rack->r_ctl.sack_count += moved_two;
9698 			counter_u64_add(rack_sack_total, moved_two);
9699 		}
9700 		/*
9701 		 * Now we need to setup for the next
9702 		 * round. First we make sure we won't
9703 		 * exceed the size of our uint32_t on
9704 		 * the various counts, and then clear out
9705 		 * moved_two.
9706 		 */
9707 		if ((rack->r_ctl.sack_moved_extra > 0xfff00000) ||
9708 		    (rack->r_ctl.sack_noextra_move > 0xfff00000)) {
9709 			rack->r_ctl.sack_moved_extra /= 2;
9710 			rack->r_ctl.sack_noextra_move /= 2;
9711 		}
9712 		if (rack->r_ctl.sack_count > 0xfff00000) {
9713 			rack->r_ctl.ack_count /= 2;
9714 			rack->r_ctl.sack_count /= 2;
9715 		}
9716 		moved_two = 0;
9717 	}
9718 out_with_totals:
9719 	if (num_sack_blks > 1) {
9720 		/*
9721 		 * You get an extra stroke if
9722 		 * you have more than one sack-blk, this
9723 		 * could be where we are skipping forward
9724 		 * and the sack-filter is still working, or
9725 		 * it could be an attacker constantly
9726 		 * moving us.
9727 		 */
9728 		rack->r_ctl.sack_moved_extra++;
9729 		counter_u64_add(rack_move_some, 1);
9730 	}
9731 out:
9732 #ifdef NETFLIX_EXP_DETECTION
9733 	rack_do_detection(tp, rack, BYTES_THIS_ACK(tp, th), ctf_fixed_maxseg(rack->rc_tp));
9734 #endif
9735 	if (changed) {
9736 		/* Something changed cancel the rack timer */
9737 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
9738 	}
9739 	tsused = tcp_get_usecs(NULL);
9740 	rsm = tcp_rack_output(tp, rack, tsused);
9741 	if ((!IN_FASTRECOVERY(tp->t_flags)) &&
9742 	    rsm &&
9743 	    ((rsm->r_flags & RACK_MUST_RXT) == 0)) {
9744 		/* Enter recovery */
9745 		entered_recovery = 1;
9746 		rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
9747 		/*
9748 		 * When we enter recovery we need to assure we send
9749 		 * one packet.
9750 		 */
9751 		if (rack->rack_no_prr == 0) {
9752 			rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
9753 			rack_log_to_prr(rack, 8, 0, __LINE__);
9754 		}
9755 		rack->r_timer_override = 1;
9756 		rack->r_early = 0;
9757 		rack->r_ctl.rc_agg_early = 0;
9758 	} else if (IN_FASTRECOVERY(tp->t_flags) &&
9759 		   rsm &&
9760 		   (rack->r_rr_config == 3)) {
9761 		/*
9762 		 * Assure we can output and we get no
9763 		 * remembered pace time except the retransmit.
9764 		 */
9765 		rack->r_timer_override = 1;
9766 		rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
9767 		rack->r_ctl.rc_resend = rsm;
9768 	}
9769 	if (IN_FASTRECOVERY(tp->t_flags) &&
9770 	    (rack->rack_no_prr == 0) &&
9771 	    (entered_recovery == 0)) {
9772 		rack_update_prr(tp, rack, changed, th_ack);
9773 		if ((rsm && (rack->r_ctl.rc_prr_sndcnt >= ctf_fixed_maxseg(tp)) &&
9774 		     ((tcp_in_hpts(rack->rc_inp) == 0) &&
9775 		      ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)))) {
9776 			/*
9777 			 * If you are pacing output you don't want
9778 			 * to override.
9779 			 */
9780 			rack->r_early = 0;
9781 			rack->r_ctl.rc_agg_early = 0;
9782 			rack->r_timer_override = 1;
9783 		}
9784 	}
9785 }
9786 
9787 static void
9788 rack_strike_dupack(struct tcp_rack *rack)
9789 {
9790 	struct rack_sendmap *rsm;
9791 
9792 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
9793 	while (rsm && (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
9794 		rsm = TAILQ_NEXT(rsm, r_tnext);
9795 		if (rsm->r_flags & RACK_MUST_RXT) {
9796 			/* Sendmap entries that are marked to
9797 			 * be retransmitted do not need dupack's
9798 			 * struck. We get these marks for a number
9799 			 * of reasons (rxt timeout with no sack,
9800 			 * mtu change, or rwnd collapses). When
9801 			 * these events occur, we know we must retransmit
9802 			 * them and mark the sendmap entries. Dupack counting
9803 			 * is not needed since we are already set to retransmit
9804 			 * it as soon as we can.
9805 			 */
9806 			continue;
9807 		}
9808 	}
9809 	if (rsm && (rsm->r_dupack < 0xff)) {
9810 		rsm->r_dupack++;
9811 		if (rsm->r_dupack >= DUP_ACK_THRESHOLD) {
9812 			struct timeval tv;
9813 			uint32_t cts;
9814 			/*
9815 			 * Here we see if we need to retransmit. For
9816 			 * a SACK type connection if enough time has passed
9817 			 * we will get a return of the rsm. For a non-sack
9818 			 * connection we will get the rsm returned if the
9819 			 * dupack value is 3 or more.
9820 			 */
9821 			cts = tcp_get_usecs(&tv);
9822 			rack->r_ctl.rc_resend = tcp_rack_output(rack->rc_tp, rack, cts);
9823 			if (rack->r_ctl.rc_resend != NULL) {
9824 				if (!IN_FASTRECOVERY(rack->rc_tp->t_flags)) {
9825 					rack_cong_signal(rack->rc_tp, CC_NDUPACK,
9826 							 rack->rc_tp->snd_una, __LINE__);
9827 				}
9828 				rack->r_wanted_output = 1;
9829 				rack->r_timer_override = 1;
9830 				rack_log_retran_reason(rack, rsm, __LINE__, 1, 3);
9831 			}
9832 		} else {
9833 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 3);
9834 		}
9835 	}
9836 }
9837 
9838 static void
9839 rack_check_bottom_drag(struct tcpcb *tp,
9840 		       struct tcp_rack *rack,
9841 		       struct socket *so, int32_t acked)
9842 {
9843 	uint32_t segsiz, minseg;
9844 
9845 	segsiz = ctf_fixed_maxseg(tp);
9846 	minseg = segsiz;
9847 
9848 	if (tp->snd_max == tp->snd_una) {
9849 		/*
9850 		 * We are doing dynamic pacing and we are way
9851 		 * under. Basically everything got acked while
9852 		 * we were still waiting on the pacer to expire.
9853 		 *
9854 		 * This means we need to boost the b/w in
9855 		 * addition to any earlier boosting of
9856 		 * the multiplier.
9857 		 */
9858 		rack->rc_dragged_bottom = 1;
9859 		rack_validate_multipliers_at_or_above100(rack);
9860 		/*
9861 		 * Lets use the segment bytes acked plus
9862 		 * the lowest RTT seen as the basis to
9863 		 * form a b/w estimate. This will be off
9864 		 * due to the fact that the true estimate
9865 		 * should be around 1/2 the time of the RTT
9866 		 * but we can settle for that.
9867 		 */
9868 		if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_VALID) &&
9869 		    acked) {
9870 			uint64_t bw, calc_bw, rtt;
9871 
9872 			rtt = rack->r_ctl.rack_rs.rs_us_rtt;
9873 			if (rtt == 0) {
9874 				/* no us sample is there a ms one? */
9875 				if (rack->r_ctl.rack_rs.rs_rtt_lowest) {
9876 					rtt = rack->r_ctl.rack_rs.rs_rtt_lowest;
9877 				} else {
9878 					goto no_measurement;
9879 				}
9880 			}
9881 			bw = acked;
9882 			calc_bw = bw * 1000000;
9883 			calc_bw /= rtt;
9884 			if (rack->r_ctl.last_max_bw &&
9885 			    (rack->r_ctl.last_max_bw < calc_bw)) {
9886 				/*
9887 				 * If we have a last calculated max bw
9888 				 * enforce it.
9889 				 */
9890 				calc_bw = rack->r_ctl.last_max_bw;
9891 			}
9892 			/* now plop it in */
9893 			if (rack->rc_gp_filled == 0) {
9894 				if (calc_bw > ONE_POINT_TWO_MEG) {
9895 					/*
9896 					 * If we have no measurement
9897 					 * don't let us set in more than
9898 					 * 1.2Mbps. If we are still too
9899 					 * low after pacing with this we
9900 					 * will hopefully have a max b/w
9901 					 * available to sanity check things.
9902 					 */
9903 					calc_bw = ONE_POINT_TWO_MEG;
9904 				}
9905 				rack->r_ctl.rc_rtt_diff = 0;
9906 				rack->r_ctl.gp_bw = calc_bw;
9907 				rack->rc_gp_filled = 1;
9908 				if (rack->r_ctl.num_measurements < RACK_REQ_AVG)
9909 					rack->r_ctl.num_measurements = RACK_REQ_AVG;
9910 				rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
9911 			} else if (calc_bw > rack->r_ctl.gp_bw) {
9912 				rack->r_ctl.rc_rtt_diff = 0;
9913 				if (rack->r_ctl.num_measurements < RACK_REQ_AVG)
9914 					rack->r_ctl.num_measurements = RACK_REQ_AVG;
9915 				rack->r_ctl.gp_bw = calc_bw;
9916 				rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
9917 			} else
9918 				rack_increase_bw_mul(rack, -1, 0, 0, 1);
9919 			if ((rack->gp_ready == 0) &&
9920 			    (rack->r_ctl.num_measurements >= rack->r_ctl.req_measurements)) {
9921 				/* We have enough measurements now */
9922 				rack->gp_ready = 1;
9923 				rack_set_cc_pacing(rack);
9924 				if (rack->defer_options)
9925 					rack_apply_deferred_options(rack);
9926 			}
9927 			/*
9928 			 * For acks over 1mss we do a extra boost to simulate
9929 			 * where we would get 2 acks (we want 110 for the mul).
9930 			 */
9931 			if (acked > segsiz)
9932 				rack_increase_bw_mul(rack, -1, 0, 0, 1);
9933 		} else {
9934 			/*
9935 			 * zero rtt possibly?, settle for just an old increase.
9936 			 */
9937 no_measurement:
9938 			rack_increase_bw_mul(rack, -1, 0, 0, 1);
9939 		}
9940 	} else if ((IN_FASTRECOVERY(tp->t_flags) == 0) &&
9941 		   (sbavail(&so->so_snd) > max((segsiz * (4 + rack_req_segs)),
9942 					       minseg)) &&
9943 		   (rack->r_ctl.cwnd_to_use > max((segsiz * (rack_req_segs + 2)), minseg)) &&
9944 		   (tp->snd_wnd > max((segsiz * (rack_req_segs + 2)), minseg)) &&
9945 		   (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) <=
9946 		    (segsiz * rack_req_segs))) {
9947 		/*
9948 		 * We are doing dynamic GP pacing and
9949 		 * we have everything except 1MSS or less
9950 		 * bytes left out. We are still pacing away.
9951 		 * And there is data that could be sent, This
9952 		 * means we are inserting delayed ack time in
9953 		 * our measurements because we are pacing too slow.
9954 		 */
9955 		rack_validate_multipliers_at_or_above100(rack);
9956 		rack->rc_dragged_bottom = 1;
9957 		rack_increase_bw_mul(rack, -1, 0, 0, 1);
9958 	}
9959 }
9960 
9961 
9962 
9963 static void
9964 rack_gain_for_fastoutput(struct tcp_rack *rack, struct tcpcb *tp, struct socket *so, uint32_t acked_amount)
9965 {
9966 	/*
9967 	 * The fast output path is enabled and we
9968 	 * have moved the cumack forward. Lets see if
9969 	 * we can expand forward the fast path length by
9970 	 * that amount. What we would ideally like to
9971 	 * do is increase the number of bytes in the
9972 	 * fast path block (left_to_send) by the
9973 	 * acked amount. However we have to gate that
9974 	 * by two factors:
9975 	 * 1) The amount outstanding and the rwnd of the peer
9976 	 *    (i.e. we don't want to exceed the rwnd of the peer).
9977 	 *    <and>
9978 	 * 2) The amount of data left in the socket buffer (i.e.
9979 	 *    we can't send beyond what is in the buffer).
9980 	 *
9981 	 * Note that this does not take into account any increase
9982 	 * in the cwnd. We will only extend the fast path by
9983 	 * what was acked.
9984 	 */
9985 	uint32_t new_total, gating_val;
9986 
9987 	new_total = acked_amount + rack->r_ctl.fsb.left_to_send;
9988 	gating_val = min((sbavail(&so->so_snd) - (tp->snd_max - tp->snd_una)),
9989 			 (tp->snd_wnd - (tp->snd_max - tp->snd_una)));
9990 	if (new_total <= gating_val) {
9991 		/* We can increase left_to_send by the acked amount */
9992 		counter_u64_add(rack_extended_rfo, 1);
9993 		rack->r_ctl.fsb.left_to_send = new_total;
9994 		KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(&rack->rc_inp->inp_socket->so_snd) - (tp->snd_max - tp->snd_una))),
9995 			("rack:%p left_to_send:%u sbavail:%u out:%u",
9996 			 rack, rack->r_ctl.fsb.left_to_send,
9997 			 sbavail(&rack->rc_inp->inp_socket->so_snd),
9998 			 (tp->snd_max - tp->snd_una)));
9999 
10000 	}
10001 }
10002 
10003 static void
10004 rack_adjust_sendmap(struct tcp_rack *rack, struct sockbuf *sb, tcp_seq snd_una)
10005 {
10006 	/*
10007 	 * Here any sendmap entry that points to the
10008 	 * beginning mbuf must be adjusted to the correct
10009 	 * offset. This must be called with:
10010 	 * 1) The socket buffer locked
10011 	 * 2) snd_una adjusted to its new postion.
10012 	 *
10013 	 * Note that (2) implies rack_ack_received has also
10014 	 * been called.
10015 	 *
10016 	 * We grab the first mbuf in the socket buffer and
10017 	 * then go through the front of the sendmap, recalculating
10018 	 * the stored offset for any sendmap entry that has
10019 	 * that mbuf. We must use the sb functions to do this
10020 	 * since its possible an add was done has well as
10021 	 * the subtraction we may have just completed. This should
10022 	 * not be a penalty though, since we just referenced the sb
10023 	 * to go in and trim off the mbufs that we freed (of course
10024 	 * there will be a penalty for the sendmap references though).
10025 	 */
10026 	struct mbuf *m;
10027 	struct rack_sendmap *rsm;
10028 
10029 	SOCKBUF_LOCK_ASSERT(sb);
10030 	m = sb->sb_mb;
10031 	rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
10032 	if ((rsm == NULL) || (m == NULL)) {
10033 		/* Nothing outstanding */
10034 		return;
10035 	}
10036 	while (rsm->m && (rsm->m == m)) {
10037 		/* one to adjust */
10038 #ifdef INVARIANTS
10039 		struct mbuf *tm;
10040 		uint32_t soff;
10041 
10042 		tm = sbsndmbuf(sb, (rsm->r_start - snd_una), &soff);
10043 		if (rsm->orig_m_len != m->m_len) {
10044 			rack_adjust_orig_mlen(rsm);
10045 		}
10046 		if (rsm->soff != soff) {
10047 			/*
10048 			 * This is not a fatal error, we anticipate it
10049 			 * might happen (the else code), so we count it here
10050 			 * so that under invariant we can see that it really
10051 			 * does happen.
10052 			 */
10053 			counter_u64_add(rack_adjust_map_bw, 1);
10054 		}
10055 		rsm->m = tm;
10056 		rsm->soff = soff;
10057 		if (tm)
10058 			rsm->orig_m_len = rsm->m->m_len;
10059 		else
10060 			rsm->orig_m_len = 0;
10061 #else
10062 		rsm->m = sbsndmbuf(sb, (rsm->r_start - snd_una), &rsm->soff);
10063 		if (rsm->m)
10064 			rsm->orig_m_len = rsm->m->m_len;
10065 		else
10066 			rsm->orig_m_len = 0;
10067 #endif
10068 		rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree,
10069 			      rsm);
10070 		if (rsm == NULL)
10071 			break;
10072 	}
10073 }
10074 
10075 /*
10076  * Return value of 1, we do not need to call rack_process_data().
10077  * return value of 0, rack_process_data can be called.
10078  * For ret_val if its 0 the TCP is locked, if its non-zero
10079  * its unlocked and probably unsafe to touch the TCB.
10080  */
10081 static int
10082 rack_process_ack(struct mbuf *m, struct tcphdr *th, struct socket *so,
10083     struct tcpcb *tp, struct tcpopt *to,
10084     uint32_t tiwin, int32_t tlen,
10085     int32_t * ofia, int32_t thflags, int32_t *ret_val)
10086 {
10087 	int32_t ourfinisacked = 0;
10088 	int32_t nsegs, acked_amount;
10089 	int32_t acked;
10090 	struct mbuf *mfree;
10091 	struct tcp_rack *rack;
10092 	int32_t under_pacing = 0;
10093 	int32_t recovery = 0;
10094 
10095 	INP_WLOCK_ASSERT(tptoinpcb(tp));
10096 
10097 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10098 	if (SEQ_GT(th->th_ack, tp->snd_max)) {
10099 		__ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val,
10100 				      &rack->r_ctl.challenge_ack_ts,
10101 				      &rack->r_ctl.challenge_ack_cnt);
10102 		rack->r_wanted_output = 1;
10103 		return (1);
10104 	}
10105 	if (rack->gp_ready &&
10106 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
10107 		under_pacing = 1;
10108 	}
10109 	if (SEQ_GEQ(th->th_ack, tp->snd_una) || to->to_nsacks) {
10110 		int in_rec, dup_ack_struck = 0;
10111 
10112 		in_rec = IN_FASTRECOVERY(tp->t_flags);
10113 		if (rack->rc_in_persist) {
10114 			tp->t_rxtshift = 0;
10115 			RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
10116 				      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
10117 		}
10118 		if ((th->th_ack == tp->snd_una) &&
10119 		    (tiwin == tp->snd_wnd) &&
10120 		    ((to->to_flags & TOF_SACK) == 0)) {
10121 			rack_strike_dupack(rack);
10122 			dup_ack_struck = 1;
10123 		}
10124 		rack_log_ack(tp, to, th, ((in_rec == 0) && IN_FASTRECOVERY(tp->t_flags)), dup_ack_struck);
10125 	}
10126 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
10127 		/*
10128 		 * Old ack, behind (or duplicate to) the last one rcv'd
10129 		 * Note: We mark reordering is occuring if its
10130 		 * less than and we have not closed our window.
10131 		 */
10132 		if (SEQ_LT(th->th_ack, tp->snd_una) && (sbspace(&so->so_rcv) > ctf_fixed_maxseg(tp))) {
10133 			rack->r_ctl.rc_reorder_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
10134 		}
10135 		return (0);
10136 	}
10137 	/*
10138 	 * If we reach this point, ACK is not a duplicate, i.e., it ACKs
10139 	 * something we sent.
10140 	 */
10141 	if (tp->t_flags & TF_NEEDSYN) {
10142 		/*
10143 		 * T/TCP: Connection was half-synchronized, and our SYN has
10144 		 * been ACK'd (so connection is now fully synchronized).  Go
10145 		 * to non-starred state, increment snd_una for ACK of SYN,
10146 		 * and check if we can do window scaling.
10147 		 */
10148 		tp->t_flags &= ~TF_NEEDSYN;
10149 		tp->snd_una++;
10150 		/* Do window scaling? */
10151 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
10152 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
10153 			tp->rcv_scale = tp->request_r_scale;
10154 			/* Send window already scaled. */
10155 		}
10156 	}
10157 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
10158 
10159 	acked = BYTES_THIS_ACK(tp, th);
10160 	if (acked) {
10161 		/*
10162 		 * Any time we move the cum-ack forward clear
10163 		 * keep-alive tied probe-not-answered. The
10164 		 * persists clears its own on entry.
10165 		 */
10166 		rack->probe_not_answered = 0;
10167 	}
10168 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
10169 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
10170 	/*
10171 	 * If we just performed our first retransmit, and the ACK arrives
10172 	 * within our recovery window, then it was a mistake to do the
10173 	 * retransmit in the first place.  Recover our original cwnd and
10174 	 * ssthresh, and proceed to transmit where we left off.
10175 	 */
10176 	if ((tp->t_flags & TF_PREVVALID) &&
10177 	    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
10178 		tp->t_flags &= ~TF_PREVVALID;
10179 		if (tp->t_rxtshift == 1 &&
10180 		    (int)(ticks - tp->t_badrxtwin) < 0)
10181 			rack_cong_signal(tp, CC_RTO_ERR, th->th_ack, __LINE__);
10182 	}
10183 	if (acked) {
10184 		/* assure we are not backed off */
10185 		tp->t_rxtshift = 0;
10186 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
10187 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
10188 		rack->rc_tlp_in_progress = 0;
10189 		rack->r_ctl.rc_tlp_cnt_out = 0;
10190 		/*
10191 		 * If it is the RXT timer we want to
10192 		 * stop it, so we can restart a TLP.
10193 		 */
10194 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
10195 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
10196 #ifdef NETFLIX_HTTP_LOGGING
10197 		tcp_http_check_for_comp(rack->rc_tp, th->th_ack);
10198 #endif
10199 	}
10200 	/*
10201 	 * If we have a timestamp reply, update smoothed round trip time. If
10202 	 * no timestamp is present but transmit timer is running and timed
10203 	 * sequence number was acked, update smoothed round trip time. Since
10204 	 * we now have an rtt measurement, cancel the timer backoff (cf.,
10205 	 * Phil Karn's retransmit alg.). Recompute the initial retransmit
10206 	 * timer.
10207 	 *
10208 	 * Some boxes send broken timestamp replies during the SYN+ACK
10209 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
10210 	 * and blow up the retransmit timer.
10211 	 */
10212 	/*
10213 	 * If all outstanding data is acked, stop retransmit timer and
10214 	 * remember to restart (more output or persist). If there is more
10215 	 * data to be acked, restart retransmit timer, using current
10216 	 * (possibly backed-off) value.
10217 	 */
10218 	if (acked == 0) {
10219 		if (ofia)
10220 			*ofia = ourfinisacked;
10221 		return (0);
10222 	}
10223 	if (IN_RECOVERY(tp->t_flags)) {
10224 		if (SEQ_LT(th->th_ack, tp->snd_recover) &&
10225 		    (SEQ_LT(th->th_ack, tp->snd_max))) {
10226 			tcp_rack_partialack(tp);
10227 		} else {
10228 			rack_post_recovery(tp, th->th_ack);
10229 			recovery = 1;
10230 		}
10231 	}
10232 	/*
10233 	 * Let the congestion control algorithm update congestion control
10234 	 * related information. This typically means increasing the
10235 	 * congestion window.
10236 	 */
10237 	rack_ack_received(tp, rack, th->th_ack, nsegs, CC_ACK, recovery);
10238 	SOCKBUF_LOCK(&so->so_snd);
10239 	acked_amount = min(acked, (int)sbavail(&so->so_snd));
10240 	tp->snd_wnd -= acked_amount;
10241 	mfree = sbcut_locked(&so->so_snd, acked_amount);
10242 	if ((sbused(&so->so_snd) == 0) &&
10243 	    (acked > acked_amount) &&
10244 	    (tp->t_state >= TCPS_FIN_WAIT_1) &&
10245 	    (tp->t_flags & TF_SENTFIN)) {
10246 		/*
10247 		 * We must be sure our fin
10248 		 * was sent and acked (we can be
10249 		 * in FIN_WAIT_1 without having
10250 		 * sent the fin).
10251 		 */
10252 		ourfinisacked = 1;
10253 	}
10254 	tp->snd_una = th->th_ack;
10255 	if (acked_amount && sbavail(&so->so_snd))
10256 		rack_adjust_sendmap(rack, &so->so_snd, tp->snd_una);
10257 	rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
10258 	/* NB: sowwakeup_locked() does an implicit unlock. */
10259 	sowwakeup_locked(so);
10260 	m_freem(mfree);
10261 	if (SEQ_GT(tp->snd_una, tp->snd_recover))
10262 		tp->snd_recover = tp->snd_una;
10263 
10264 	if (SEQ_LT(tp->snd_nxt, tp->snd_una)) {
10265 		tp->snd_nxt = tp->snd_una;
10266 	}
10267 	if (under_pacing &&
10268 	    (rack->use_fixed_rate == 0) &&
10269 	    (rack->in_probe_rtt == 0) &&
10270 	    rack->rc_gp_dyn_mul &&
10271 	    rack->rc_always_pace) {
10272 		/* Check if we are dragging bottom */
10273 		rack_check_bottom_drag(tp, rack, so, acked);
10274 	}
10275 	if (tp->snd_una == tp->snd_max) {
10276 		/* Nothing left outstanding */
10277 		tp->t_flags &= ~TF_PREVVALID;
10278 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
10279 		rack->r_ctl.retran_during_recovery = 0;
10280 		rack->r_ctl.dsack_byte_cnt = 0;
10281 		if (rack->r_ctl.rc_went_idle_time == 0)
10282 			rack->r_ctl.rc_went_idle_time = 1;
10283 		rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
10284 		if (sbavail(&tptosocket(tp)->so_snd) == 0)
10285 			tp->t_acktime = 0;
10286 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
10287 		/* Set need output so persist might get set */
10288 		rack->r_wanted_output = 1;
10289 		sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
10290 		if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
10291 		    (sbavail(&so->so_snd) == 0) &&
10292 		    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
10293 			/*
10294 			 * The socket was gone and the
10295 			 * peer sent data (now or in the past), time to
10296 			 * reset him.
10297 			 */
10298 			*ret_val = 1;
10299 			/* tcp_close will kill the inp pre-log the Reset */
10300 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
10301 			tp = tcp_close(tp);
10302 			ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, tlen);
10303 			return (1);
10304 		}
10305 	}
10306 	if (ofia)
10307 		*ofia = ourfinisacked;
10308 	return (0);
10309 }
10310 
10311 
10312 static void
10313 rack_log_collapse(struct tcp_rack *rack, uint32_t cnt, uint32_t split, uint32_t out, int line,
10314 		  int dir, uint32_t flags, struct rack_sendmap *rsm)
10315 {
10316 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
10317 		union tcp_log_stackspecific log;
10318 		struct timeval tv;
10319 
10320 		memset(&log, 0, sizeof(log));
10321 		log.u_bbr.flex1 = cnt;
10322 		log.u_bbr.flex2 = split;
10323 		log.u_bbr.flex3 = out;
10324 		log.u_bbr.flex4 = line;
10325 		log.u_bbr.flex5 = rack->r_must_retran;
10326 		log.u_bbr.flex6 = flags;
10327 		log.u_bbr.flex7 = rack->rc_has_collapsed;
10328 		log.u_bbr.flex8 = dir;	/*
10329 					 * 1 is collapsed, 0 is uncollapsed,
10330 					 * 2 is log of a rsm being marked, 3 is a split.
10331 					 */
10332 		if (rsm == NULL)
10333 			log.u_bbr.rttProp = 0;
10334 		else
10335 			log.u_bbr.rttProp = (uint64_t)rsm;
10336 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
10337 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
10338 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
10339 		    &rack->rc_inp->inp_socket->so_rcv,
10340 		    &rack->rc_inp->inp_socket->so_snd,
10341 		    TCP_RACK_LOG_COLLAPSE, 0,
10342 		    0, &log, false, &tv);
10343 	}
10344 }
10345 
10346 static void
10347 rack_collapsed_window(struct tcp_rack *rack, uint32_t out, int line)
10348 {
10349 	/*
10350 	 * Here all we do is mark the collapsed point and set the flag.
10351 	 * This may happen again and again, but there is no
10352 	 * sense splitting our map until we know where the
10353 	 * peer finally lands in the collapse.
10354 	 */
10355 	rack_trace_point(rack, RACK_TP_COLLAPSED_WND);
10356 	if ((rack->rc_has_collapsed == 0) ||
10357 	    (rack->r_ctl.last_collapse_point != (rack->rc_tp->snd_una + rack->rc_tp->snd_wnd)))
10358 		counter_u64_add(rack_collapsed_win_seen, 1);
10359 	rack->r_ctl.last_collapse_point = rack->rc_tp->snd_una + rack->rc_tp->snd_wnd;
10360 	rack->r_ctl.high_collapse_point = rack->rc_tp->snd_max;
10361 	rack->rc_has_collapsed = 1;
10362 	rack->r_collapse_point_valid = 1;
10363 	rack_log_collapse(rack, 0, 0, rack->r_ctl.last_collapse_point, line, 1, 0, NULL);
10364 }
10365 
10366 static void
10367 rack_un_collapse_window(struct tcp_rack *rack, int line)
10368 {
10369 	struct rack_sendmap *nrsm, *rsm, fe;
10370 	int cnt = 0, split = 0;
10371 #ifdef INVARIANTS
10372 	struct rack_sendmap *insret;
10373 #endif
10374 
10375 	memset(&fe, 0, sizeof(fe));
10376 	rack->rc_has_collapsed = 0;
10377 	fe.r_start = rack->r_ctl.last_collapse_point;
10378 	rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
10379 	if (rsm == NULL) {
10380 		/* Nothing to do maybe the peer ack'ed it all */
10381 		rack_log_collapse(rack, 0, 0, ctf_outstanding(rack->rc_tp), line, 0, 0, NULL);
10382 		return;
10383 	}
10384 	/* Now do we need to split this one? */
10385 	if (SEQ_GT(rack->r_ctl.last_collapse_point, rsm->r_start)) {
10386 		rack_log_collapse(rack, rsm->r_start, rsm->r_end,
10387 				  rack->r_ctl.last_collapse_point, line, 3, rsm->r_flags, rsm);
10388 		nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
10389 		if (nrsm == NULL) {
10390 			/* We can't get a rsm, mark all? */
10391 			nrsm = rsm;
10392 			goto no_split;
10393 		}
10394 		/* Clone it */
10395 		split = 1;
10396 		rack_clone_rsm(rack, nrsm, rsm, rack->r_ctl.last_collapse_point);
10397 #ifndef INVARIANTS
10398 		(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
10399 #else
10400 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
10401 		if (insret != NULL) {
10402 			panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
10403 			      nrsm, insret, rack, rsm);
10404 		}
10405 #endif
10406 		rack_log_map_chg(rack->rc_tp, rack, NULL, rsm, nrsm, MAP_SPLIT,
10407 				 rack->r_ctl.last_collapse_point, __LINE__);
10408 		if (rsm->r_in_tmap) {
10409 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
10410 			nrsm->r_in_tmap = 1;
10411 		}
10412 		/*
10413 		 * Set in the new RSM as the
10414 		 * collapsed starting point
10415 		 */
10416 		rsm = nrsm;
10417 	}
10418 no_split:
10419 	RB_FOREACH_FROM(nrsm, rack_rb_tree_head, rsm) {
10420 		nrsm->r_flags |= RACK_RWND_COLLAPSED;
10421 		rack_log_collapse(rack, nrsm->r_start, nrsm->r_end, 0, line, 4, nrsm->r_flags, nrsm);
10422 		cnt++;
10423 	}
10424 	if (cnt) {
10425 		counter_u64_add(rack_collapsed_win, 1);
10426 	}
10427 	rack_log_collapse(rack, cnt, split, ctf_outstanding(rack->rc_tp), line, 0, 0, NULL);
10428 }
10429 
10430 static void
10431 rack_handle_delayed_ack(struct tcpcb *tp, struct tcp_rack *rack,
10432 			int32_t tlen, int32_t tfo_syn)
10433 {
10434 	if (DELAY_ACK(tp, tlen) || tfo_syn) {
10435 		if (rack->rc_dack_mode &&
10436 		    (tlen > 500) &&
10437 		    (rack->rc_dack_toggle == 1)) {
10438 			goto no_delayed_ack;
10439 		}
10440 		rack_timer_cancel(tp, rack,
10441 				  rack->r_ctl.rc_rcvtime, __LINE__);
10442 		tp->t_flags |= TF_DELACK;
10443 	} else {
10444 no_delayed_ack:
10445 		rack->r_wanted_output = 1;
10446 		tp->t_flags |= TF_ACKNOW;
10447 		if (rack->rc_dack_mode) {
10448 			if (tp->t_flags & TF_DELACK)
10449 				rack->rc_dack_toggle = 1;
10450 			else
10451 				rack->rc_dack_toggle = 0;
10452 		}
10453 	}
10454 }
10455 
10456 static void
10457 rack_validate_fo_sendwin_up(struct tcpcb *tp, struct tcp_rack *rack)
10458 {
10459 	/*
10460 	 * If fast output is in progress, lets validate that
10461 	 * the new window did not shrink on us and make it
10462 	 * so fast output should end.
10463 	 */
10464 	if (rack->r_fast_output) {
10465 		uint32_t out;
10466 
10467 		/*
10468 		 * Calculate what we will send if left as is
10469 		 * and compare that to our send window.
10470 		 */
10471 		out = ctf_outstanding(tp);
10472 		if ((out + rack->r_ctl.fsb.left_to_send) > tp->snd_wnd) {
10473 			/* ok we have an issue */
10474 			if (out >= tp->snd_wnd) {
10475 				/* Turn off fast output the window is met or collapsed */
10476 				rack->r_fast_output = 0;
10477 			} else {
10478 				/* we have some room left */
10479 				rack->r_ctl.fsb.left_to_send = tp->snd_wnd - out;
10480 				if (rack->r_ctl.fsb.left_to_send < ctf_fixed_maxseg(tp)) {
10481 					/* If not at least 1 full segment never mind */
10482 					rack->r_fast_output = 0;
10483 				}
10484 			}
10485 		}
10486 	}
10487 }
10488 
10489 
10490 /*
10491  * Return value of 1, the TCB is unlocked and most
10492  * likely gone, return value of 0, the TCP is still
10493  * locked.
10494  */
10495 static int
10496 rack_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so,
10497     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
10498     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
10499 {
10500 	/*
10501 	 * Update window information. Don't look at window if no ACK: TAC's
10502 	 * send garbage on first SYN.
10503 	 */
10504 	int32_t nsegs;
10505 	int32_t tfo_syn;
10506 	struct tcp_rack *rack;
10507 
10508 	INP_WLOCK_ASSERT(tptoinpcb(tp));
10509 
10510 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10511 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
10512 	if ((thflags & TH_ACK) &&
10513 	    (SEQ_LT(tp->snd_wl1, th->th_seq) ||
10514 	    (tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) ||
10515 	    (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) {
10516 		/* keep track of pure window updates */
10517 		if (tlen == 0 &&
10518 		    tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd)
10519 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
10520 		tp->snd_wnd = tiwin;
10521 		rack_validate_fo_sendwin_up(tp, rack);
10522 		tp->snd_wl1 = th->th_seq;
10523 		tp->snd_wl2 = th->th_ack;
10524 		if (tp->snd_wnd > tp->max_sndwnd)
10525 			tp->max_sndwnd = tp->snd_wnd;
10526 		rack->r_wanted_output = 1;
10527 	} else if (thflags & TH_ACK) {
10528 		if ((tp->snd_wl2 == th->th_ack) && (tiwin < tp->snd_wnd)) {
10529 			tp->snd_wnd = tiwin;
10530 			rack_validate_fo_sendwin_up(tp, rack);
10531 			tp->snd_wl1 = th->th_seq;
10532 			tp->snd_wl2 = th->th_ack;
10533 		}
10534 	}
10535 	if (tp->snd_wnd < ctf_outstanding(tp))
10536 		/* The peer collapsed the window */
10537 		rack_collapsed_window(rack, ctf_outstanding(tp), __LINE__);
10538 	else if (rack->rc_has_collapsed)
10539 		rack_un_collapse_window(rack, __LINE__);
10540 	if ((rack->r_collapse_point_valid) &&
10541 	    (SEQ_GT(th->th_ack, rack->r_ctl.high_collapse_point)))
10542 		rack->r_collapse_point_valid = 0;
10543 	/* Was persist timer active and now we have window space? */
10544 	if ((rack->rc_in_persist != 0) &&
10545 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
10546 				rack->r_ctl.rc_pace_min_segs))) {
10547 		rack_exit_persist(tp, rack, rack->r_ctl.rc_rcvtime);
10548 		tp->snd_nxt = tp->snd_max;
10549 		/* Make sure we output to start the timer */
10550 		rack->r_wanted_output = 1;
10551 	}
10552 	/* Do we enter persists? */
10553 	if ((rack->rc_in_persist == 0) &&
10554 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
10555 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
10556 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
10557 	    sbavail(&tptosocket(tp)->so_snd) &&
10558 	    (sbavail(&tptosocket(tp)->so_snd) > tp->snd_wnd)) {
10559 		/*
10560 		 * Here the rwnd is less than
10561 		 * the pacing size, we are established,
10562 		 * nothing is outstanding, and there is
10563 		 * data to send. Enter persists.
10564 		 */
10565 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
10566 	}
10567 	if (tp->t_flags2 & TF2_DROP_AF_DATA) {
10568 		m_freem(m);
10569 		return (0);
10570 	}
10571 	/*
10572 	 * don't process the URG bit, ignore them drag
10573 	 * along the up.
10574 	 */
10575 	tp->rcv_up = tp->rcv_nxt;
10576 
10577 	/*
10578 	 * Process the segment text, merging it into the TCP sequencing
10579 	 * queue, and arranging for acknowledgment of receipt if necessary.
10580 	 * This process logically involves adjusting tp->rcv_wnd as data is
10581 	 * presented to the user (this happens in tcp_usrreq.c, case
10582 	 * PRU_RCVD).  If a FIN has already been received on this connection
10583 	 * then we just ignore the text.
10584 	 */
10585 	tfo_syn = ((tp->t_state == TCPS_SYN_RECEIVED) &&
10586 		   IS_FASTOPEN(tp->t_flags));
10587 	if ((tlen || (thflags & TH_FIN) || (tfo_syn && tlen > 0)) &&
10588 	    TCPS_HAVERCVDFIN(tp->t_state) == 0) {
10589 		tcp_seq save_start = th->th_seq;
10590 		tcp_seq save_rnxt  = tp->rcv_nxt;
10591 		int     save_tlen  = tlen;
10592 
10593 		m_adj(m, drop_hdrlen);	/* delayed header drop */
10594 		/*
10595 		 * Insert segment which includes th into TCP reassembly
10596 		 * queue with control block tp.  Set thflags to whether
10597 		 * reassembly now includes a segment with FIN.  This handles
10598 		 * the common case inline (segment is the next to be
10599 		 * received on an established connection, and the queue is
10600 		 * empty), avoiding linkage into and removal from the queue
10601 		 * and repetition of various conversions. Set DELACK for
10602 		 * segments received in order, but ack immediately when
10603 		 * segments are out of order (so fast retransmit can work).
10604 		 */
10605 		if (th->th_seq == tp->rcv_nxt &&
10606 		    SEGQ_EMPTY(tp) &&
10607 		    (TCPS_HAVEESTABLISHED(tp->t_state) ||
10608 		    tfo_syn)) {
10609 #ifdef NETFLIX_SB_LIMITS
10610 			u_int mcnt, appended;
10611 
10612 			if (so->so_rcv.sb_shlim) {
10613 				mcnt = m_memcnt(m);
10614 				appended = 0;
10615 				if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
10616 				    CFO_NOSLEEP, NULL) == false) {
10617 					counter_u64_add(tcp_sb_shlim_fails, 1);
10618 					m_freem(m);
10619 					return (0);
10620 				}
10621 			}
10622 #endif
10623 			rack_handle_delayed_ack(tp, rack, tlen, tfo_syn);
10624 			tp->rcv_nxt += tlen;
10625 			if (tlen &&
10626 			    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
10627 			    (tp->t_fbyte_in == 0)) {
10628 				tp->t_fbyte_in = ticks;
10629 				if (tp->t_fbyte_in == 0)
10630 					tp->t_fbyte_in = 1;
10631 				if (tp->t_fbyte_out && tp->t_fbyte_in)
10632 					tp->t_flags2 |= TF2_FBYTES_COMPLETE;
10633 			}
10634 			thflags = tcp_get_flags(th) & TH_FIN;
10635 			KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
10636 			KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
10637 			SOCKBUF_LOCK(&so->so_rcv);
10638 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
10639 				m_freem(m);
10640 			} else
10641 #ifdef NETFLIX_SB_LIMITS
10642 				appended =
10643 #endif
10644 					sbappendstream_locked(&so->so_rcv, m, 0);
10645 
10646 			rack_log_wakeup(tp,rack, &so->so_rcv, tlen, 1);
10647 			/* NB: sorwakeup_locked() does an implicit unlock. */
10648 			sorwakeup_locked(so);
10649 #ifdef NETFLIX_SB_LIMITS
10650 			if (so->so_rcv.sb_shlim && appended != mcnt)
10651 				counter_fo_release(so->so_rcv.sb_shlim,
10652 				    mcnt - appended);
10653 #endif
10654 		} else {
10655 			/*
10656 			 * XXX: Due to the header drop above "th" is
10657 			 * theoretically invalid by now.  Fortunately
10658 			 * m_adj() doesn't actually frees any mbufs when
10659 			 * trimming from the head.
10660 			 */
10661 			tcp_seq temp = save_start;
10662 
10663 			thflags = tcp_reass(tp, th, &temp, &tlen, m);
10664 			tp->t_flags |= TF_ACKNOW;
10665 			if (tp->t_flags & TF_WAKESOR) {
10666 				tp->t_flags &= ~TF_WAKESOR;
10667 				/* NB: sorwakeup_locked() does an implicit unlock. */
10668 				sorwakeup_locked(so);
10669 			}
10670 		}
10671 		if ((tp->t_flags & TF_SACK_PERMIT) &&
10672 		    (save_tlen > 0) &&
10673 		    TCPS_HAVEESTABLISHED(tp->t_state)) {
10674 			if ((tlen == 0) && (SEQ_LT(save_start, save_rnxt))) {
10675 				/*
10676 				 * DSACK actually handled in the fastpath
10677 				 * above.
10678 				 */
10679 				RACK_OPTS_INC(tcp_sack_path_1);
10680 				tcp_update_sack_list(tp, save_start,
10681 				    save_start + save_tlen);
10682 			} else if ((tlen > 0) && SEQ_GT(tp->rcv_nxt, save_rnxt)) {
10683 				if ((tp->rcv_numsacks >= 1) &&
10684 				    (tp->sackblks[0].end == save_start)) {
10685 					/*
10686 					 * Partial overlap, recorded at todrop
10687 					 * above.
10688 					 */
10689 					RACK_OPTS_INC(tcp_sack_path_2a);
10690 					tcp_update_sack_list(tp,
10691 					    tp->sackblks[0].start,
10692 					    tp->sackblks[0].end);
10693 				} else {
10694 					RACK_OPTS_INC(tcp_sack_path_2b);
10695 					tcp_update_dsack_list(tp, save_start,
10696 					    save_start + save_tlen);
10697 				}
10698 			} else if (tlen >= save_tlen) {
10699 				/* Update of sackblks. */
10700 				RACK_OPTS_INC(tcp_sack_path_3);
10701 				tcp_update_dsack_list(tp, save_start,
10702 				    save_start + save_tlen);
10703 			} else if (tlen > 0) {
10704 				RACK_OPTS_INC(tcp_sack_path_4);
10705 				tcp_update_dsack_list(tp, save_start,
10706 				    save_start + tlen);
10707 			}
10708 		}
10709 	} else {
10710 		m_freem(m);
10711 		thflags &= ~TH_FIN;
10712 	}
10713 
10714 	/*
10715 	 * If FIN is received ACK the FIN and let the user know that the
10716 	 * connection is closing.
10717 	 */
10718 	if (thflags & TH_FIN) {
10719 		if (TCPS_HAVERCVDFIN(tp->t_state) == 0) {
10720 			/* The socket upcall is handled by socantrcvmore. */
10721 			socantrcvmore(so);
10722 			/*
10723 			 * If connection is half-synchronized (ie NEEDSYN
10724 			 * flag on) then delay ACK, so it may be piggybacked
10725 			 * when SYN is sent. Otherwise, since we received a
10726 			 * FIN then no more input can be expected, send ACK
10727 			 * now.
10728 			 */
10729 			if (tp->t_flags & TF_NEEDSYN) {
10730 				rack_timer_cancel(tp, rack,
10731 				    rack->r_ctl.rc_rcvtime, __LINE__);
10732 				tp->t_flags |= TF_DELACK;
10733 			} else {
10734 				tp->t_flags |= TF_ACKNOW;
10735 			}
10736 			tp->rcv_nxt++;
10737 		}
10738 		switch (tp->t_state) {
10739 			/*
10740 			 * In SYN_RECEIVED and ESTABLISHED STATES enter the
10741 			 * CLOSE_WAIT state.
10742 			 */
10743 		case TCPS_SYN_RECEIVED:
10744 			tp->t_starttime = ticks;
10745 			/* FALLTHROUGH */
10746 		case TCPS_ESTABLISHED:
10747 			rack_timer_cancel(tp, rack,
10748 			    rack->r_ctl.rc_rcvtime, __LINE__);
10749 			tcp_state_change(tp, TCPS_CLOSE_WAIT);
10750 			break;
10751 
10752 			/*
10753 			 * If still in FIN_WAIT_1 STATE FIN has not been
10754 			 * acked so enter the CLOSING state.
10755 			 */
10756 		case TCPS_FIN_WAIT_1:
10757 			rack_timer_cancel(tp, rack,
10758 			    rack->r_ctl.rc_rcvtime, __LINE__);
10759 			tcp_state_change(tp, TCPS_CLOSING);
10760 			break;
10761 
10762 			/*
10763 			 * In FIN_WAIT_2 state enter the TIME_WAIT state,
10764 			 * starting the time-wait timer, turning off the
10765 			 * other standard timers.
10766 			 */
10767 		case TCPS_FIN_WAIT_2:
10768 			rack_timer_cancel(tp, rack,
10769 			    rack->r_ctl.rc_rcvtime, __LINE__);
10770 			tcp_twstart(tp);
10771 			return (1);
10772 		}
10773 	}
10774 	/*
10775 	 * Return any desired output.
10776 	 */
10777 	if ((tp->t_flags & TF_ACKNOW) ||
10778 	    (sbavail(&so->so_snd) > (tp->snd_max - tp->snd_una))) {
10779 		rack->r_wanted_output = 1;
10780 	}
10781 	return (0);
10782 }
10783 
10784 /*
10785  * Here nothing is really faster, its just that we
10786  * have broken out the fast-data path also just like
10787  * the fast-ack.
10788  */
10789 static int
10790 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th, struct socket *so,
10791     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
10792     uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos)
10793 {
10794 	int32_t nsegs;
10795 	int32_t newsize = 0;	/* automatic sockbuf scaling */
10796 	struct tcp_rack *rack;
10797 #ifdef NETFLIX_SB_LIMITS
10798 	u_int mcnt, appended;
10799 #endif
10800 #ifdef TCPDEBUG
10801 	/*
10802 	 * The size of tcp_saveipgen must be the size of the max ip header,
10803 	 * now IPv6.
10804 	 */
10805 	u_char tcp_saveipgen[IP6_HDR_LEN];
10806 	struct tcphdr tcp_savetcp;
10807 	short ostate = 0;
10808 
10809 #endif
10810 	/*
10811 	 * If last ACK falls within this segment's sequence numbers, record
10812 	 * the timestamp. NOTE that the test is modified according to the
10813 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
10814 	 */
10815 	if (__predict_false(th->th_seq != tp->rcv_nxt)) {
10816 		return (0);
10817 	}
10818 	if (__predict_false(tp->snd_nxt != tp->snd_max)) {
10819 		return (0);
10820 	}
10821 	if (tiwin && tiwin != tp->snd_wnd) {
10822 		return (0);
10823 	}
10824 	if (__predict_false((tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN)))) {
10825 		return (0);
10826 	}
10827 	if (__predict_false((to->to_flags & TOF_TS) &&
10828 	    (TSTMP_LT(to->to_tsval, tp->ts_recent)))) {
10829 		return (0);
10830 	}
10831 	if (__predict_false((th->th_ack != tp->snd_una))) {
10832 		return (0);
10833 	}
10834 	if (__predict_false(tlen > sbspace(&so->so_rcv))) {
10835 		return (0);
10836 	}
10837 	if ((to->to_flags & TOF_TS) != 0 &&
10838 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
10839 		tp->ts_recent_age = tcp_ts_getticks();
10840 		tp->ts_recent = to->to_tsval;
10841 	}
10842 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10843 	/*
10844 	 * This is a pure, in-sequence data packet with nothing on the
10845 	 * reassembly queue and we have enough buffer space to take it.
10846 	 */
10847 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
10848 
10849 #ifdef NETFLIX_SB_LIMITS
10850 	if (so->so_rcv.sb_shlim) {
10851 		mcnt = m_memcnt(m);
10852 		appended = 0;
10853 		if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
10854 		    CFO_NOSLEEP, NULL) == false) {
10855 			counter_u64_add(tcp_sb_shlim_fails, 1);
10856 			m_freem(m);
10857 			return (1);
10858 		}
10859 	}
10860 #endif
10861 	/* Clean receiver SACK report if present */
10862 	if (tp->rcv_numsacks)
10863 		tcp_clean_sackreport(tp);
10864 	KMOD_TCPSTAT_INC(tcps_preddat);
10865 	tp->rcv_nxt += tlen;
10866 	if (tlen &&
10867 	    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
10868 	    (tp->t_fbyte_in == 0)) {
10869 		tp->t_fbyte_in = ticks;
10870 		if (tp->t_fbyte_in == 0)
10871 			tp->t_fbyte_in = 1;
10872 		if (tp->t_fbyte_out && tp->t_fbyte_in)
10873 			tp->t_flags2 |= TF2_FBYTES_COMPLETE;
10874 	}
10875 	/*
10876 	 * Pull snd_wl1 up to prevent seq wrap relative to th_seq.
10877 	 */
10878 	tp->snd_wl1 = th->th_seq;
10879 	/*
10880 	 * Pull rcv_up up to prevent seq wrap relative to rcv_nxt.
10881 	 */
10882 	tp->rcv_up = tp->rcv_nxt;
10883 	KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
10884 	KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
10885 #ifdef TCPDEBUG
10886 	if (so->so_options & SO_DEBUG)
10887 		tcp_trace(TA_INPUT, ostate, tp,
10888 		    (void *)tcp_saveipgen, &tcp_savetcp, 0);
10889 #endif
10890 	newsize = tcp_autorcvbuf(m, th, so, tp, tlen);
10891 
10892 	/* Add data to socket buffer. */
10893 	SOCKBUF_LOCK(&so->so_rcv);
10894 	if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
10895 		m_freem(m);
10896 	} else {
10897 		/*
10898 		 * Set new socket buffer size. Give up when limit is
10899 		 * reached.
10900 		 */
10901 		if (newsize)
10902 			if (!sbreserve_locked(so, SO_RCV, newsize, NULL))
10903 				so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
10904 		m_adj(m, drop_hdrlen);	/* delayed header drop */
10905 #ifdef NETFLIX_SB_LIMITS
10906 		appended =
10907 #endif
10908 			sbappendstream_locked(&so->so_rcv, m, 0);
10909 		ctf_calc_rwin(so, tp);
10910 	}
10911 	rack_log_wakeup(tp,rack, &so->so_rcv, tlen, 1);
10912 	/* NB: sorwakeup_locked() does an implicit unlock. */
10913 	sorwakeup_locked(so);
10914 #ifdef NETFLIX_SB_LIMITS
10915 	if (so->so_rcv.sb_shlim && mcnt != appended)
10916 		counter_fo_release(so->so_rcv.sb_shlim, mcnt - appended);
10917 #endif
10918 	rack_handle_delayed_ack(tp, rack, tlen, 0);
10919 	if (tp->snd_una == tp->snd_max)
10920 		sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
10921 	return (1);
10922 }
10923 
10924 /*
10925  * This subfunction is used to try to highly optimize the
10926  * fast path. We again allow window updates that are
10927  * in sequence to remain in the fast-path. We also add
10928  * in the __predict's to attempt to help the compiler.
10929  * Note that if we return a 0, then we can *not* process
10930  * it and the caller should push the packet into the
10931  * slow-path.
10932  */
10933 static int
10934 rack_fastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
10935     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
10936     uint32_t tiwin, int32_t nxt_pkt, uint32_t cts)
10937 {
10938 	int32_t acked;
10939 	int32_t nsegs;
10940 #ifdef TCPDEBUG
10941 	/*
10942 	 * The size of tcp_saveipgen must be the size of the max ip header,
10943 	 * now IPv6.
10944 	 */
10945 	u_char tcp_saveipgen[IP6_HDR_LEN];
10946 	struct tcphdr tcp_savetcp;
10947 	short ostate = 0;
10948 #endif
10949 	int32_t under_pacing = 0;
10950 	struct tcp_rack *rack;
10951 
10952 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
10953 		/* Old ack, behind (or duplicate to) the last one rcv'd */
10954 		return (0);
10955 	}
10956 	if (__predict_false(SEQ_GT(th->th_ack, tp->snd_max))) {
10957 		/* Above what we have sent? */
10958 		return (0);
10959 	}
10960 	if (__predict_false(tp->snd_nxt != tp->snd_max)) {
10961 		/* We are retransmitting */
10962 		return (0);
10963 	}
10964 	if (__predict_false(tiwin == 0)) {
10965 		/* zero window */
10966 		return (0);
10967 	}
10968 	if (__predict_false(tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN))) {
10969 		/* We need a SYN or a FIN, unlikely.. */
10970 		return (0);
10971 	}
10972 	if ((to->to_flags & TOF_TS) && __predict_false(TSTMP_LT(to->to_tsval, tp->ts_recent))) {
10973 		/* Timestamp is behind .. old ack with seq wrap? */
10974 		return (0);
10975 	}
10976 	if (__predict_false(IN_RECOVERY(tp->t_flags))) {
10977 		/* Still recovering */
10978 		return (0);
10979 	}
10980 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10981 	if (rack->r_ctl.rc_sacked) {
10982 		/* We have sack holes on our scoreboard */
10983 		return (0);
10984 	}
10985 	/* Ok if we reach here, we can process a fast-ack */
10986 	if (rack->gp_ready &&
10987 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
10988 		under_pacing = 1;
10989 	}
10990 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
10991 	rack_log_ack(tp, to, th, 0, 0);
10992 	/* Did the window get updated? */
10993 	if (tiwin != tp->snd_wnd) {
10994 		tp->snd_wnd = tiwin;
10995 		rack_validate_fo_sendwin_up(tp, rack);
10996 		tp->snd_wl1 = th->th_seq;
10997 		if (tp->snd_wnd > tp->max_sndwnd)
10998 			tp->max_sndwnd = tp->snd_wnd;
10999 	}
11000 	/* Do we exit persists? */
11001 	if ((rack->rc_in_persist != 0) &&
11002 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
11003 			       rack->r_ctl.rc_pace_min_segs))) {
11004 		rack_exit_persist(tp, rack, cts);
11005 	}
11006 	/* Do we enter persists? */
11007 	if ((rack->rc_in_persist == 0) &&
11008 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
11009 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
11010 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
11011 	    sbavail(&tptosocket(tp)->so_snd) &&
11012 	    (sbavail(&tptosocket(tp)->so_snd) > tp->snd_wnd)) {
11013 		/*
11014 		 * Here the rwnd is less than
11015 		 * the pacing size, we are established,
11016 		 * nothing is outstanding, and there is
11017 		 * data to send. Enter persists.
11018 		 */
11019 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
11020 	}
11021 	/*
11022 	 * If last ACK falls within this segment's sequence numbers, record
11023 	 * the timestamp. NOTE that the test is modified according to the
11024 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
11025 	 */
11026 	if ((to->to_flags & TOF_TS) != 0 &&
11027 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
11028 		tp->ts_recent_age = tcp_ts_getticks();
11029 		tp->ts_recent = to->to_tsval;
11030 	}
11031 	/*
11032 	 * This is a pure ack for outstanding data.
11033 	 */
11034 	KMOD_TCPSTAT_INC(tcps_predack);
11035 
11036 	/*
11037 	 * "bad retransmit" recovery.
11038 	 */
11039 	if ((tp->t_flags & TF_PREVVALID) &&
11040 	    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
11041 		tp->t_flags &= ~TF_PREVVALID;
11042 		if (tp->t_rxtshift == 1 &&
11043 		    (int)(ticks - tp->t_badrxtwin) < 0)
11044 			rack_cong_signal(tp, CC_RTO_ERR, th->th_ack, __LINE__);
11045 	}
11046 	/*
11047 	 * Recalculate the transmit timer / rtt.
11048 	 *
11049 	 * Some boxes send broken timestamp replies during the SYN+ACK
11050 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
11051 	 * and blow up the retransmit timer.
11052 	 */
11053 	acked = BYTES_THIS_ACK(tp, th);
11054 
11055 #ifdef TCP_HHOOK
11056 	/* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */
11057 	hhook_run_tcp_est_in(tp, th, to);
11058 #endif
11059 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
11060 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
11061 	if (acked) {
11062 		struct mbuf *mfree;
11063 
11064 		rack_ack_received(tp, rack, th->th_ack, nsegs, CC_ACK, 0);
11065 		SOCKBUF_LOCK(&so->so_snd);
11066 		mfree = sbcut_locked(&so->so_snd, acked);
11067 		tp->snd_una = th->th_ack;
11068 		/* Note we want to hold the sb lock through the sendmap adjust */
11069 		rack_adjust_sendmap(rack, &so->so_snd, tp->snd_una);
11070 		/* Wake up the socket if we have room to write more */
11071 		rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
11072 		sowwakeup_locked(so);
11073 		m_freem(mfree);
11074 		tp->t_rxtshift = 0;
11075 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
11076 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
11077 		rack->rc_tlp_in_progress = 0;
11078 		rack->r_ctl.rc_tlp_cnt_out = 0;
11079 		/*
11080 		 * If it is the RXT timer we want to
11081 		 * stop it, so we can restart a TLP.
11082 		 */
11083 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
11084 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
11085 #ifdef NETFLIX_HTTP_LOGGING
11086 		tcp_http_check_for_comp(rack->rc_tp, th->th_ack);
11087 #endif
11088 	}
11089 	/*
11090 	 * Let the congestion control algorithm update congestion control
11091 	 * related information. This typically means increasing the
11092 	 * congestion window.
11093 	 */
11094 	if (tp->snd_wnd < ctf_outstanding(tp)) {
11095 		/* The peer collapsed the window */
11096 		rack_collapsed_window(rack, ctf_outstanding(tp), __LINE__);
11097 	} else if (rack->rc_has_collapsed)
11098 		rack_un_collapse_window(rack, __LINE__);
11099 	if ((rack->r_collapse_point_valid) &&
11100 	    (SEQ_GT(tp->snd_una, rack->r_ctl.high_collapse_point)))
11101 		rack->r_collapse_point_valid = 0;
11102 	/*
11103 	 * Pull snd_wl2 up to prevent seq wrap relative to th_ack.
11104 	 */
11105 	tp->snd_wl2 = th->th_ack;
11106 	tp->t_dupacks = 0;
11107 	m_freem(m);
11108 	/* ND6_HINT(tp);	 *//* Some progress has been made. */
11109 
11110 	/*
11111 	 * If all outstanding data are acked, stop retransmit timer,
11112 	 * otherwise restart timer using current (possibly backed-off)
11113 	 * value. If process is waiting for space, wakeup/selwakeup/signal.
11114 	 * If data are ready to send, let tcp_output decide between more
11115 	 * output or persist.
11116 	 */
11117 #ifdef TCPDEBUG
11118 	if (so->so_options & SO_DEBUG)
11119 		tcp_trace(TA_INPUT, ostate, tp,
11120 		    (void *)tcp_saveipgen,
11121 		    &tcp_savetcp, 0);
11122 #endif
11123 	if (under_pacing &&
11124 	    (rack->use_fixed_rate == 0) &&
11125 	    (rack->in_probe_rtt == 0) &&
11126 	    rack->rc_gp_dyn_mul &&
11127 	    rack->rc_always_pace) {
11128 		/* Check if we are dragging bottom */
11129 		rack_check_bottom_drag(tp, rack, so, acked);
11130 	}
11131 	if (tp->snd_una == tp->snd_max) {
11132 		tp->t_flags &= ~TF_PREVVALID;
11133 		rack->r_ctl.retran_during_recovery = 0;
11134 		rack->r_ctl.dsack_byte_cnt = 0;
11135 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
11136 		if (rack->r_ctl.rc_went_idle_time == 0)
11137 			rack->r_ctl.rc_went_idle_time = 1;
11138 		rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
11139 		if (sbavail(&tptosocket(tp)->so_snd) == 0)
11140 			tp->t_acktime = 0;
11141 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
11142 	}
11143 	if (acked && rack->r_fast_output)
11144 		rack_gain_for_fastoutput(rack, tp, so, (uint32_t)acked);
11145 	if (sbavail(&so->so_snd)) {
11146 		rack->r_wanted_output = 1;
11147 	}
11148 	return (1);
11149 }
11150 
11151 /*
11152  * Return value of 1, the TCB is unlocked and most
11153  * likely gone, return value of 0, the TCP is still
11154  * locked.
11155  */
11156 static int
11157 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th, struct socket *so,
11158     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11159     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11160 {
11161 	int32_t ret_val = 0;
11162 	int32_t todrop;
11163 	int32_t ourfinisacked = 0;
11164 	struct tcp_rack *rack;
11165 
11166 	INP_WLOCK_ASSERT(tptoinpcb(tp));
11167 
11168 	ctf_calc_rwin(so, tp);
11169 	/*
11170 	 * If the state is SYN_SENT: if seg contains an ACK, but not for our
11171 	 * SYN, drop the input. if seg contains a RST, then drop the
11172 	 * connection. if seg does not contain SYN, then drop it. Otherwise
11173 	 * this is an acceptable SYN segment initialize tp->rcv_nxt and
11174 	 * tp->irs if seg contains ack then advance tp->snd_una if seg
11175 	 * contains an ECE and ECN support is enabled, the stream is ECN
11176 	 * capable. if SYN has been acked change to ESTABLISHED else
11177 	 * SYN_RCVD state arrange for segment to be acked (eventually)
11178 	 * continue processing rest of data/controls.
11179 	 */
11180 	if ((thflags & TH_ACK) &&
11181 	    (SEQ_LEQ(th->th_ack, tp->iss) ||
11182 	    SEQ_GT(th->th_ack, tp->snd_max))) {
11183 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11184 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11185 		return (1);
11186 	}
11187 	if ((thflags & (TH_ACK | TH_RST)) == (TH_ACK | TH_RST)) {
11188 		TCP_PROBE5(connect__refused, NULL, tp,
11189 		    mtod(m, const char *), tp, th);
11190 		tp = tcp_drop(tp, ECONNREFUSED);
11191 		ctf_do_drop(m, tp);
11192 		return (1);
11193 	}
11194 	if (thflags & TH_RST) {
11195 		ctf_do_drop(m, tp);
11196 		return (1);
11197 	}
11198 	if (!(thflags & TH_SYN)) {
11199 		ctf_do_drop(m, tp);
11200 		return (1);
11201 	}
11202 	tp->irs = th->th_seq;
11203 	tcp_rcvseqinit(tp);
11204 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11205 	if (thflags & TH_ACK) {
11206 		int tfo_partial = 0;
11207 
11208 		KMOD_TCPSTAT_INC(tcps_connects);
11209 		soisconnected(so);
11210 #ifdef MAC
11211 		mac_socketpeer_set_from_mbuf(m, so);
11212 #endif
11213 		/* Do window scaling on this connection? */
11214 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
11215 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
11216 			tp->rcv_scale = tp->request_r_scale;
11217 		}
11218 		tp->rcv_adv += min(tp->rcv_wnd,
11219 		    TCP_MAXWIN << tp->rcv_scale);
11220 		/*
11221 		 * If not all the data that was sent in the TFO SYN
11222 		 * has been acked, resend the remainder right away.
11223 		 */
11224 		if (IS_FASTOPEN(tp->t_flags) &&
11225 		    (tp->snd_una != tp->snd_max)) {
11226 			tp->snd_nxt = th->th_ack;
11227 			tfo_partial = 1;
11228 		}
11229 		/*
11230 		 * If there's data, delay ACK; if there's also a FIN ACKNOW
11231 		 * will be turned on later.
11232 		 */
11233 		if (DELAY_ACK(tp, tlen) && tlen != 0 && !tfo_partial) {
11234 			rack_timer_cancel(tp, rack,
11235 					  rack->r_ctl.rc_rcvtime, __LINE__);
11236 			tp->t_flags |= TF_DELACK;
11237 		} else {
11238 			rack->r_wanted_output = 1;
11239 			tp->t_flags |= TF_ACKNOW;
11240 			rack->rc_dack_toggle = 0;
11241 		}
11242 
11243 		tcp_ecn_input_syn_sent(tp, thflags, iptos);
11244 
11245 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
11246 			/*
11247 			 * We advance snd_una for the
11248 			 * fast open case. If th_ack is
11249 			 * acknowledging data beyond
11250 			 * snd_una we can't just call
11251 			 * ack-processing since the
11252 			 * data stream in our send-map
11253 			 * will start at snd_una + 1 (one
11254 			 * beyond the SYN). If its just
11255 			 * equal we don't need to do that
11256 			 * and there is no send_map.
11257 			 */
11258 			tp->snd_una++;
11259 		}
11260 		/*
11261 		 * Received <SYN,ACK> in SYN_SENT[*] state. Transitions:
11262 		 * SYN_SENT  --> ESTABLISHED SYN_SENT* --> FIN_WAIT_1
11263 		 */
11264 		tp->t_starttime = ticks;
11265 		if (tp->t_flags & TF_NEEDFIN) {
11266 			tcp_state_change(tp, TCPS_FIN_WAIT_1);
11267 			tp->t_flags &= ~TF_NEEDFIN;
11268 			thflags &= ~TH_SYN;
11269 		} else {
11270 			tcp_state_change(tp, TCPS_ESTABLISHED);
11271 			TCP_PROBE5(connect__established, NULL, tp,
11272 			    mtod(m, const char *), tp, th);
11273 			rack_cc_conn_init(tp);
11274 		}
11275 	} else {
11276 		/*
11277 		 * Received initial SYN in SYN-SENT[*] state => simultaneous
11278 		 * open.  If segment contains CC option and there is a
11279 		 * cached CC, apply TAO test. If it succeeds, connection is *
11280 		 * half-synchronized. Otherwise, do 3-way handshake:
11281 		 * SYN-SENT -> SYN-RECEIVED SYN-SENT* -> SYN-RECEIVED* If
11282 		 * there was no CC option, clear cached CC value.
11283 		 */
11284 		tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN | TF_SONOTCONN);
11285 		tcp_state_change(tp, TCPS_SYN_RECEIVED);
11286 	}
11287 	/*
11288 	 * Advance th->th_seq to correspond to first data byte. If data,
11289 	 * trim to stay within window, dropping FIN if necessary.
11290 	 */
11291 	th->th_seq++;
11292 	if (tlen > tp->rcv_wnd) {
11293 		todrop = tlen - tp->rcv_wnd;
11294 		m_adj(m, -todrop);
11295 		tlen = tp->rcv_wnd;
11296 		thflags &= ~TH_FIN;
11297 		KMOD_TCPSTAT_INC(tcps_rcvpackafterwin);
11298 		KMOD_TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop);
11299 	}
11300 	tp->snd_wl1 = th->th_seq - 1;
11301 	tp->rcv_up = th->th_seq;
11302 	/*
11303 	 * Client side of transaction: already sent SYN and data. If the
11304 	 * remote host used T/TCP to validate the SYN, our data will be
11305 	 * ACK'd; if so, enter normal data segment processing in the middle
11306 	 * of step 5, ack processing. Otherwise, goto step 6.
11307 	 */
11308 	if (thflags & TH_ACK) {
11309 		/* For syn-sent we need to possibly update the rtt */
11310 		if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
11311 			uint32_t t, mcts;
11312 
11313 			mcts = tcp_ts_getticks();
11314 			t = (mcts - to->to_tsecr) * HPTS_USEC_IN_MSEC;
11315 			if (!tp->t_rttlow || tp->t_rttlow > t)
11316 				tp->t_rttlow = t;
11317 			rack_log_rtt_sample_calc(rack, t, (to->to_tsecr * 1000), (mcts * 1000), 4);
11318 			tcp_rack_xmit_timer(rack, t + 1, 1, t, 0, NULL, 2);
11319 			tcp_rack_xmit_timer_commit(rack, tp);
11320 		}
11321 		if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val))
11322 			return (ret_val);
11323 		/* We may have changed to FIN_WAIT_1 above */
11324 		if (tp->t_state == TCPS_FIN_WAIT_1) {
11325 			/*
11326 			 * In FIN_WAIT_1 STATE in addition to the processing
11327 			 * for the ESTABLISHED state if our FIN is now
11328 			 * acknowledged then enter FIN_WAIT_2.
11329 			 */
11330 			if (ourfinisacked) {
11331 				/*
11332 				 * If we can't receive any more data, then
11333 				 * closing user can proceed. Starting the
11334 				 * timer is contrary to the specification,
11335 				 * but if we don't get a FIN we'll hang
11336 				 * forever.
11337 				 *
11338 				 * XXXjl: we should release the tp also, and
11339 				 * use a compressed state.
11340 				 */
11341 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
11342 					soisdisconnected(so);
11343 					tcp_timer_activate(tp, TT_2MSL,
11344 					    (tcp_fast_finwait2_recycle ?
11345 					    tcp_finwait2_timeout :
11346 					    TP_MAXIDLE(tp)));
11347 				}
11348 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
11349 			}
11350 		}
11351 	}
11352 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11353 	   tiwin, thflags, nxt_pkt));
11354 }
11355 
11356 /*
11357  * Return value of 1, the TCB is unlocked and most
11358  * likely gone, return value of 0, the TCP is still
11359  * locked.
11360  */
11361 static int
11362 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
11363     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11364     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11365 {
11366 	struct tcp_rack *rack;
11367 	int32_t ret_val = 0;
11368 	int32_t ourfinisacked = 0;
11369 
11370 	ctf_calc_rwin(so, tp);
11371 	if ((thflags & TH_ACK) &&
11372 	    (SEQ_LEQ(th->th_ack, tp->snd_una) ||
11373 	    SEQ_GT(th->th_ack, tp->snd_max))) {
11374 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11375 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11376 		return (1);
11377 	}
11378 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11379 	if (IS_FASTOPEN(tp->t_flags)) {
11380 		/*
11381 		 * When a TFO connection is in SYN_RECEIVED, the
11382 		 * only valid packets are the initial SYN, a
11383 		 * retransmit/copy of the initial SYN (possibly with
11384 		 * a subset of the original data), a valid ACK, a
11385 		 * FIN, or a RST.
11386 		 */
11387 		if ((thflags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
11388 			tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11389 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11390 			return (1);
11391 		} else if (thflags & TH_SYN) {
11392 			/* non-initial SYN is ignored */
11393 			if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT) ||
11394 			    (rack->r_ctl.rc_hpts_flags & PACE_TMR_TLP) ||
11395 			    (rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK)) {
11396 				ctf_do_drop(m, NULL);
11397 				return (0);
11398 			}
11399 		} else if (!(thflags & (TH_ACK | TH_FIN | TH_RST))) {
11400 			ctf_do_drop(m, NULL);
11401 			return (0);
11402 		}
11403 	}
11404 
11405 	if ((thflags & TH_RST) ||
11406 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11407 		return (__ctf_process_rst(m, th, so, tp,
11408 					  &rack->r_ctl.challenge_ack_ts,
11409 					  &rack->r_ctl.challenge_ack_cnt));
11410 	/*
11411 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11412 	 * it's less than ts_recent, drop it.
11413 	 */
11414 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11415 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11416 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11417 			return (ret_val);
11418 	}
11419 	/*
11420 	 * In the SYN-RECEIVED state, validate that the packet belongs to
11421 	 * this connection before trimming the data to fit the receive
11422 	 * window.  Check the sequence number versus IRS since we know the
11423 	 * sequence numbers haven't wrapped.  This is a partial fix for the
11424 	 * "LAND" DoS attack.
11425 	 */
11426 	if (SEQ_LT(th->th_seq, tp->irs)) {
11427 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11428 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11429 		return (1);
11430 	}
11431 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11432 			      &rack->r_ctl.challenge_ack_ts,
11433 			      &rack->r_ctl.challenge_ack_cnt)) {
11434 		return (ret_val);
11435 	}
11436 	/*
11437 	 * If last ACK falls within this segment's sequence numbers, record
11438 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11439 	 * from the latest proposal of the tcplw@cray.com list (Braden
11440 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11441 	 * with our earlier PAWS tests, so this check should be solely
11442 	 * predicated on the sequence space of this segment. 3) That we
11443 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11444 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11445 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11446 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11447 	 * p.869. In such cases, we can still calculate the RTT correctly
11448 	 * when RCV.NXT == Last.ACK.Sent.
11449 	 */
11450 	if ((to->to_flags & TOF_TS) != 0 &&
11451 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11452 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11453 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11454 		tp->ts_recent_age = tcp_ts_getticks();
11455 		tp->ts_recent = to->to_tsval;
11456 	}
11457 	tp->snd_wnd = tiwin;
11458 	rack_validate_fo_sendwin_up(tp, rack);
11459 	/*
11460 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11461 	 * is on (half-synchronized state), then queue data for later
11462 	 * processing; else drop segment and return.
11463 	 */
11464 	if ((thflags & TH_ACK) == 0) {
11465 		if (IS_FASTOPEN(tp->t_flags)) {
11466 			rack_cc_conn_init(tp);
11467 		}
11468 		return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11469 		    tiwin, thflags, nxt_pkt));
11470 	}
11471 	KMOD_TCPSTAT_INC(tcps_connects);
11472 	if (tp->t_flags & TF_SONOTCONN) {
11473 		tp->t_flags &= ~TF_SONOTCONN;
11474 		soisconnected(so);
11475 	}
11476 	/* Do window scaling? */
11477 	if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
11478 	    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
11479 		tp->rcv_scale = tp->request_r_scale;
11480 	}
11481 	/*
11482 	 * Make transitions: SYN-RECEIVED  -> ESTABLISHED SYN-RECEIVED* ->
11483 	 * FIN-WAIT-1
11484 	 */
11485 	tp->t_starttime = ticks;
11486 	if (IS_FASTOPEN(tp->t_flags) && tp->t_tfo_pending) {
11487 		tcp_fastopen_decrement_counter(tp->t_tfo_pending);
11488 		tp->t_tfo_pending = NULL;
11489 	}
11490 	if (tp->t_flags & TF_NEEDFIN) {
11491 		tcp_state_change(tp, TCPS_FIN_WAIT_1);
11492 		tp->t_flags &= ~TF_NEEDFIN;
11493 	} else {
11494 		tcp_state_change(tp, TCPS_ESTABLISHED);
11495 		TCP_PROBE5(accept__established, NULL, tp,
11496 		    mtod(m, const char *), tp, th);
11497 		/*
11498 		 * TFO connections call cc_conn_init() during SYN
11499 		 * processing.  Calling it again here for such connections
11500 		 * is not harmless as it would undo the snd_cwnd reduction
11501 		 * that occurs when a TFO SYN|ACK is retransmitted.
11502 		 */
11503 		if (!IS_FASTOPEN(tp->t_flags))
11504 			rack_cc_conn_init(tp);
11505 	}
11506 	/*
11507 	 * Account for the ACK of our SYN prior to
11508 	 * regular ACK processing below, except for
11509 	 * simultaneous SYN, which is handled later.
11510 	 */
11511 	if (SEQ_GT(th->th_ack, tp->snd_una) && !(tp->t_flags & TF_NEEDSYN))
11512 		tp->snd_una++;
11513 	/*
11514 	 * If segment contains data or ACK, will call tcp_reass() later; if
11515 	 * not, do so now to pass queued data to user.
11516 	 */
11517 	if (tlen == 0 && (thflags & TH_FIN) == 0) {
11518 		(void) tcp_reass(tp, (struct tcphdr *)0, NULL, 0,
11519 		    (struct mbuf *)0);
11520 		if (tp->t_flags & TF_WAKESOR) {
11521 			tp->t_flags &= ~TF_WAKESOR;
11522 			/* NB: sorwakeup_locked() does an implicit unlock. */
11523 			sorwakeup_locked(so);
11524 		}
11525 	}
11526 	tp->snd_wl1 = th->th_seq - 1;
11527 	/* For syn-recv we need to possibly update the rtt */
11528 	if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
11529 		uint32_t t, mcts;
11530 
11531 		mcts = tcp_ts_getticks();
11532 		t = (mcts - to->to_tsecr) * HPTS_USEC_IN_MSEC;
11533 		if (!tp->t_rttlow || tp->t_rttlow > t)
11534 			tp->t_rttlow = t;
11535 		rack_log_rtt_sample_calc(rack, t, (to->to_tsecr * 1000), (mcts * 1000), 5);
11536 		tcp_rack_xmit_timer(rack, t + 1, 1, t, 0, NULL, 2);
11537 		tcp_rack_xmit_timer_commit(rack, tp);
11538 	}
11539 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
11540 		return (ret_val);
11541 	}
11542 	if (tp->t_state == TCPS_FIN_WAIT_1) {
11543 		/* We could have went to FIN_WAIT_1 (or EST) above */
11544 		/*
11545 		 * In FIN_WAIT_1 STATE in addition to the processing for the
11546 		 * ESTABLISHED state if our FIN is now acknowledged then
11547 		 * enter FIN_WAIT_2.
11548 		 */
11549 		if (ourfinisacked) {
11550 			/*
11551 			 * If we can't receive any more data, then closing
11552 			 * user can proceed. Starting the timer is contrary
11553 			 * to the specification, but if we don't get a FIN
11554 			 * we'll hang forever.
11555 			 *
11556 			 * XXXjl: we should release the tp also, and use a
11557 			 * compressed state.
11558 			 */
11559 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
11560 				soisdisconnected(so);
11561 				tcp_timer_activate(tp, TT_2MSL,
11562 				    (tcp_fast_finwait2_recycle ?
11563 				    tcp_finwait2_timeout :
11564 				    TP_MAXIDLE(tp)));
11565 			}
11566 			tcp_state_change(tp, TCPS_FIN_WAIT_2);
11567 		}
11568 	}
11569 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11570 	    tiwin, thflags, nxt_pkt));
11571 }
11572 
11573 /*
11574  * Return value of 1, the TCB is unlocked and most
11575  * likely gone, return value of 0, the TCP is still
11576  * locked.
11577  */
11578 static int
11579 rack_do_established(struct mbuf *m, struct tcphdr *th, struct socket *so,
11580     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11581     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11582 {
11583 	int32_t ret_val = 0;
11584 	struct tcp_rack *rack;
11585 
11586 	/*
11587 	 * Header prediction: check for the two common cases of a
11588 	 * uni-directional data xfer.  If the packet has no control flags,
11589 	 * is in-sequence, the window didn't change and we're not
11590 	 * retransmitting, it's a candidate.  If the length is zero and the
11591 	 * ack moved forward, we're the sender side of the xfer.  Just free
11592 	 * the data acked & wake any higher level process that was blocked
11593 	 * waiting for space.  If the length is non-zero and the ack didn't
11594 	 * move, we're the receiver side.  If we're getting packets in-order
11595 	 * (the reassembly queue is empty), add the data toc The socket
11596 	 * buffer and note that we need a delayed ack. Make sure that the
11597 	 * hidden state-flags are also off. Since we check for
11598 	 * TCPS_ESTABLISHED first, it can only be TH_NEEDSYN.
11599 	 */
11600 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11601 	if (__predict_true(((to->to_flags & TOF_SACK) == 0)) &&
11602 	    __predict_true((thflags & (TH_SYN | TH_FIN | TH_RST | TH_ACK)) == TH_ACK) &&
11603 	    __predict_true(SEGQ_EMPTY(tp)) &&
11604 	    __predict_true(th->th_seq == tp->rcv_nxt)) {
11605 		if (tlen == 0) {
11606 			if (rack_fastack(m, th, so, tp, to, drop_hdrlen, tlen,
11607 			    tiwin, nxt_pkt, rack->r_ctl.rc_rcvtime)) {
11608 				return (0);
11609 			}
11610 		} else {
11611 			if (rack_do_fastnewdata(m, th, so, tp, to, drop_hdrlen, tlen,
11612 			    tiwin, nxt_pkt, iptos)) {
11613 				return (0);
11614 			}
11615 		}
11616 	}
11617 	ctf_calc_rwin(so, tp);
11618 
11619 	if ((thflags & TH_RST) ||
11620 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11621 		return (__ctf_process_rst(m, th, so, tp,
11622 					  &rack->r_ctl.challenge_ack_ts,
11623 					  &rack->r_ctl.challenge_ack_cnt));
11624 
11625 	/*
11626 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11627 	 * synchronized state.
11628 	 */
11629 	if (thflags & TH_SYN) {
11630 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
11631 		return (ret_val);
11632 	}
11633 	/*
11634 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11635 	 * it's less than ts_recent, drop it.
11636 	 */
11637 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11638 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11639 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11640 			return (ret_val);
11641 	}
11642 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11643 			      &rack->r_ctl.challenge_ack_ts,
11644 			      &rack->r_ctl.challenge_ack_cnt)) {
11645 		return (ret_val);
11646 	}
11647 	/*
11648 	 * If last ACK falls within this segment's sequence numbers, record
11649 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11650 	 * from the latest proposal of the tcplw@cray.com list (Braden
11651 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11652 	 * with our earlier PAWS tests, so this check should be solely
11653 	 * predicated on the sequence space of this segment. 3) That we
11654 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11655 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11656 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11657 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11658 	 * p.869. In such cases, we can still calculate the RTT correctly
11659 	 * when RCV.NXT == Last.ACK.Sent.
11660 	 */
11661 	if ((to->to_flags & TOF_TS) != 0 &&
11662 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11663 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11664 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11665 		tp->ts_recent_age = tcp_ts_getticks();
11666 		tp->ts_recent = to->to_tsval;
11667 	}
11668 	/*
11669 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11670 	 * is on (half-synchronized state), then queue data for later
11671 	 * processing; else drop segment and return.
11672 	 */
11673 	if ((thflags & TH_ACK) == 0) {
11674 		if (tp->t_flags & TF_NEEDSYN) {
11675 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11676 			    tiwin, thflags, nxt_pkt));
11677 
11678 		} else if (tp->t_flags & TF_ACKNOW) {
11679 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
11680 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
11681 			return (ret_val);
11682 		} else {
11683 			ctf_do_drop(m, NULL);
11684 			return (0);
11685 		}
11686 	}
11687 	/*
11688 	 * Ack processing.
11689 	 */
11690 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
11691 		return (ret_val);
11692 	}
11693 	if (sbavail(&so->so_snd)) {
11694 		if (ctf_progress_timeout_check(tp, true)) {
11695 			rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
11696 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11697 			return (1);
11698 		}
11699 	}
11700 	/* State changes only happen in rack_process_data() */
11701 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11702 	    tiwin, thflags, nxt_pkt));
11703 }
11704 
11705 /*
11706  * Return value of 1, the TCB is unlocked and most
11707  * likely gone, return value of 0, the TCP is still
11708  * locked.
11709  */
11710 static int
11711 rack_do_close_wait(struct mbuf *m, struct tcphdr *th, struct socket *so,
11712     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11713     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11714 {
11715 	int32_t ret_val = 0;
11716 	struct tcp_rack *rack;
11717 
11718 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11719 	ctf_calc_rwin(so, tp);
11720 	if ((thflags & TH_RST) ||
11721 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11722 		return (__ctf_process_rst(m, th, so, tp,
11723 					  &rack->r_ctl.challenge_ack_ts,
11724 					  &rack->r_ctl.challenge_ack_cnt));
11725 	/*
11726 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11727 	 * synchronized state.
11728 	 */
11729 	if (thflags & TH_SYN) {
11730 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
11731 		return (ret_val);
11732 	}
11733 	/*
11734 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11735 	 * it's less than ts_recent, drop it.
11736 	 */
11737 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11738 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11739 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11740 			return (ret_val);
11741 	}
11742 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11743 			      &rack->r_ctl.challenge_ack_ts,
11744 			      &rack->r_ctl.challenge_ack_cnt)) {
11745 		return (ret_val);
11746 	}
11747 	/*
11748 	 * If last ACK falls within this segment's sequence numbers, record
11749 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11750 	 * from the latest proposal of the tcplw@cray.com list (Braden
11751 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11752 	 * with our earlier PAWS tests, so this check should be solely
11753 	 * predicated on the sequence space of this segment. 3) That we
11754 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11755 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11756 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11757 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11758 	 * p.869. In such cases, we can still calculate the RTT correctly
11759 	 * when RCV.NXT == Last.ACK.Sent.
11760 	 */
11761 	if ((to->to_flags & TOF_TS) != 0 &&
11762 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11763 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11764 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11765 		tp->ts_recent_age = tcp_ts_getticks();
11766 		tp->ts_recent = to->to_tsval;
11767 	}
11768 	/*
11769 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11770 	 * is on (half-synchronized state), then queue data for later
11771 	 * processing; else drop segment and return.
11772 	 */
11773 	if ((thflags & TH_ACK) == 0) {
11774 		if (tp->t_flags & TF_NEEDSYN) {
11775 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11776 			    tiwin, thflags, nxt_pkt));
11777 
11778 		} else if (tp->t_flags & TF_ACKNOW) {
11779 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
11780 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
11781 			return (ret_val);
11782 		} else {
11783 			ctf_do_drop(m, NULL);
11784 			return (0);
11785 		}
11786 	}
11787 	/*
11788 	 * Ack processing.
11789 	 */
11790 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
11791 		return (ret_val);
11792 	}
11793 	if (sbavail(&so->so_snd)) {
11794 		if (ctf_progress_timeout_check(tp, true)) {
11795 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
11796 						tp, tick, PROGRESS_DROP, __LINE__);
11797 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11798 			return (1);
11799 		}
11800 	}
11801 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11802 	    tiwin, thflags, nxt_pkt));
11803 }
11804 
11805 static int
11806 rack_check_data_after_close(struct mbuf *m,
11807     struct tcpcb *tp, int32_t *tlen, struct tcphdr *th, struct socket *so)
11808 {
11809 	struct tcp_rack *rack;
11810 
11811 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11812 	if (rack->rc_allow_data_af_clo == 0) {
11813 	close_now:
11814 		tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
11815 		/* tcp_close will kill the inp pre-log the Reset */
11816 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
11817 		tp = tcp_close(tp);
11818 		KMOD_TCPSTAT_INC(tcps_rcvafterclose);
11819 		ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, (*tlen));
11820 		return (1);
11821 	}
11822 	if (sbavail(&so->so_snd) == 0)
11823 		goto close_now;
11824 	/* Ok we allow data that is ignored and a followup reset */
11825 	tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
11826 	tp->rcv_nxt = th->th_seq + *tlen;
11827 	tp->t_flags2 |= TF2_DROP_AF_DATA;
11828 	rack->r_wanted_output = 1;
11829 	*tlen = 0;
11830 	return (0);
11831 }
11832 
11833 /*
11834  * Return value of 1, the TCB is unlocked and most
11835  * likely gone, return value of 0, the TCP is still
11836  * locked.
11837  */
11838 static int
11839 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, struct socket *so,
11840     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11841     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11842 {
11843 	int32_t ret_val = 0;
11844 	int32_t ourfinisacked = 0;
11845 	struct tcp_rack *rack;
11846 
11847 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11848 	ctf_calc_rwin(so, tp);
11849 
11850 	if ((thflags & TH_RST) ||
11851 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11852 		return (__ctf_process_rst(m, th, so, tp,
11853 					  &rack->r_ctl.challenge_ack_ts,
11854 					  &rack->r_ctl.challenge_ack_cnt));
11855 	/*
11856 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11857 	 * synchronized state.
11858 	 */
11859 	if (thflags & TH_SYN) {
11860 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
11861 		return (ret_val);
11862 	}
11863 	/*
11864 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11865 	 * it's less than ts_recent, drop it.
11866 	 */
11867 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11868 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11869 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11870 			return (ret_val);
11871 	}
11872 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11873 			      &rack->r_ctl.challenge_ack_ts,
11874 			      &rack->r_ctl.challenge_ack_cnt)) {
11875 		return (ret_val);
11876 	}
11877 	/*
11878 	 * If new data are received on a connection after the user processes
11879 	 * are gone, then RST the other end.
11880 	 */
11881 	if ((tp->t_flags & TF_CLOSED) && tlen &&
11882 	    rack_check_data_after_close(m, tp, &tlen, th, so))
11883 		return (1);
11884 	/*
11885 	 * If last ACK falls within this segment's sequence numbers, record
11886 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11887 	 * from the latest proposal of the tcplw@cray.com list (Braden
11888 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11889 	 * with our earlier PAWS tests, so this check should be solely
11890 	 * predicated on the sequence space of this segment. 3) That we
11891 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11892 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11893 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11894 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11895 	 * p.869. In such cases, we can still calculate the RTT correctly
11896 	 * when RCV.NXT == Last.ACK.Sent.
11897 	 */
11898 	if ((to->to_flags & TOF_TS) != 0 &&
11899 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11900 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11901 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11902 		tp->ts_recent_age = tcp_ts_getticks();
11903 		tp->ts_recent = to->to_tsval;
11904 	}
11905 	/*
11906 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11907 	 * is on (half-synchronized state), then queue data for later
11908 	 * processing; else drop segment and return.
11909 	 */
11910 	if ((thflags & TH_ACK) == 0) {
11911 		if (tp->t_flags & TF_NEEDSYN) {
11912 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11913 			    tiwin, thflags, nxt_pkt));
11914 		} else if (tp->t_flags & TF_ACKNOW) {
11915 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
11916 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
11917 			return (ret_val);
11918 		} else {
11919 			ctf_do_drop(m, NULL);
11920 			return (0);
11921 		}
11922 	}
11923 	/*
11924 	 * Ack processing.
11925 	 */
11926 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
11927 		return (ret_val);
11928 	}
11929 	if (ourfinisacked) {
11930 		/*
11931 		 * If we can't receive any more data, then closing user can
11932 		 * proceed. Starting the timer is contrary to the
11933 		 * specification, but if we don't get a FIN we'll hang
11934 		 * forever.
11935 		 *
11936 		 * XXXjl: we should release the tp also, and use a
11937 		 * compressed state.
11938 		 */
11939 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
11940 			soisdisconnected(so);
11941 			tcp_timer_activate(tp, TT_2MSL,
11942 			    (tcp_fast_finwait2_recycle ?
11943 			    tcp_finwait2_timeout :
11944 			    TP_MAXIDLE(tp)));
11945 		}
11946 		tcp_state_change(tp, TCPS_FIN_WAIT_2);
11947 	}
11948 	if (sbavail(&so->so_snd)) {
11949 		if (ctf_progress_timeout_check(tp, true)) {
11950 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
11951 						tp, tick, PROGRESS_DROP, __LINE__);
11952 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11953 			return (1);
11954 		}
11955 	}
11956 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11957 	    tiwin, thflags, nxt_pkt));
11958 }
11959 
11960 /*
11961  * Return value of 1, the TCB is unlocked and most
11962  * likely gone, return value of 0, the TCP is still
11963  * locked.
11964  */
11965 static int
11966 rack_do_closing(struct mbuf *m, struct tcphdr *th, struct socket *so,
11967     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11968     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11969 {
11970 	int32_t ret_val = 0;
11971 	int32_t ourfinisacked = 0;
11972 	struct tcp_rack *rack;
11973 
11974 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11975 	ctf_calc_rwin(so, tp);
11976 
11977 	if ((thflags & TH_RST) ||
11978 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11979 		return (__ctf_process_rst(m, th, so, tp,
11980 					  &rack->r_ctl.challenge_ack_ts,
11981 					  &rack->r_ctl.challenge_ack_cnt));
11982 	/*
11983 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11984 	 * synchronized state.
11985 	 */
11986 	if (thflags & TH_SYN) {
11987 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
11988 		return (ret_val);
11989 	}
11990 	/*
11991 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11992 	 * it's less than ts_recent, drop it.
11993 	 */
11994 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11995 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11996 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11997 			return (ret_val);
11998 	}
11999 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
12000 			      &rack->r_ctl.challenge_ack_ts,
12001 			      &rack->r_ctl.challenge_ack_cnt)) {
12002 		return (ret_val);
12003 	}
12004 	/*
12005 	 * If new data are received on a connection after the user processes
12006 	 * are gone, then RST the other end.
12007 	 */
12008 	if ((tp->t_flags & TF_CLOSED) && tlen &&
12009 	    rack_check_data_after_close(m, tp, &tlen, th, so))
12010 		return (1);
12011 	/*
12012 	 * If last ACK falls within this segment's sequence numbers, record
12013 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
12014 	 * from the latest proposal of the tcplw@cray.com list (Braden
12015 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
12016 	 * with our earlier PAWS tests, so this check should be solely
12017 	 * predicated on the sequence space of this segment. 3) That we
12018 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
12019 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
12020 	 * SEG.Len, This modified check allows us to overcome RFC1323's
12021 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
12022 	 * p.869. In such cases, we can still calculate the RTT correctly
12023 	 * when RCV.NXT == Last.ACK.Sent.
12024 	 */
12025 	if ((to->to_flags & TOF_TS) != 0 &&
12026 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
12027 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
12028 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
12029 		tp->ts_recent_age = tcp_ts_getticks();
12030 		tp->ts_recent = to->to_tsval;
12031 	}
12032 	/*
12033 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
12034 	 * is on (half-synchronized state), then queue data for later
12035 	 * processing; else drop segment and return.
12036 	 */
12037 	if ((thflags & TH_ACK) == 0) {
12038 		if (tp->t_flags & TF_NEEDSYN) {
12039 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12040 			    tiwin, thflags, nxt_pkt));
12041 		} else if (tp->t_flags & TF_ACKNOW) {
12042 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
12043 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
12044 			return (ret_val);
12045 		} else {
12046 			ctf_do_drop(m, NULL);
12047 			return (0);
12048 		}
12049 	}
12050 	/*
12051 	 * Ack processing.
12052 	 */
12053 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
12054 		return (ret_val);
12055 	}
12056 	if (ourfinisacked) {
12057 		tcp_twstart(tp);
12058 		m_freem(m);
12059 		return (1);
12060 	}
12061 	if (sbavail(&so->so_snd)) {
12062 		if (ctf_progress_timeout_check(tp, true)) {
12063 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
12064 						tp, tick, PROGRESS_DROP, __LINE__);
12065 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
12066 			return (1);
12067 		}
12068 	}
12069 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12070 	    tiwin, thflags, nxt_pkt));
12071 }
12072 
12073 /*
12074  * Return value of 1, the TCB is unlocked and most
12075  * likely gone, return value of 0, the TCP is still
12076  * locked.
12077  */
12078 static int
12079 rack_do_lastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
12080     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12081     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
12082 {
12083 	int32_t ret_val = 0;
12084 	int32_t ourfinisacked = 0;
12085 	struct tcp_rack *rack;
12086 
12087 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12088 	ctf_calc_rwin(so, tp);
12089 
12090 	if ((thflags & TH_RST) ||
12091 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
12092 		return (__ctf_process_rst(m, th, so, tp,
12093 					  &rack->r_ctl.challenge_ack_ts,
12094 					  &rack->r_ctl.challenge_ack_cnt));
12095 	/*
12096 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
12097 	 * synchronized state.
12098 	 */
12099 	if (thflags & TH_SYN) {
12100 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
12101 		return (ret_val);
12102 	}
12103 	/*
12104 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
12105 	 * it's less than ts_recent, drop it.
12106 	 */
12107 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
12108 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
12109 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
12110 			return (ret_val);
12111 	}
12112 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
12113 			      &rack->r_ctl.challenge_ack_ts,
12114 			      &rack->r_ctl.challenge_ack_cnt)) {
12115 		return (ret_val);
12116 	}
12117 	/*
12118 	 * If new data are received on a connection after the user processes
12119 	 * are gone, then RST the other end.
12120 	 */
12121 	if ((tp->t_flags & TF_CLOSED) && tlen &&
12122 	    rack_check_data_after_close(m, tp, &tlen, th, so))
12123 		return (1);
12124 	/*
12125 	 * If last ACK falls within this segment's sequence numbers, record
12126 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
12127 	 * from the latest proposal of the tcplw@cray.com list (Braden
12128 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
12129 	 * with our earlier PAWS tests, so this check should be solely
12130 	 * predicated on the sequence space of this segment. 3) That we
12131 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
12132 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
12133 	 * SEG.Len, This modified check allows us to overcome RFC1323's
12134 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
12135 	 * p.869. In such cases, we can still calculate the RTT correctly
12136 	 * when RCV.NXT == Last.ACK.Sent.
12137 	 */
12138 	if ((to->to_flags & TOF_TS) != 0 &&
12139 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
12140 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
12141 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
12142 		tp->ts_recent_age = tcp_ts_getticks();
12143 		tp->ts_recent = to->to_tsval;
12144 	}
12145 	/*
12146 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
12147 	 * is on (half-synchronized state), then queue data for later
12148 	 * processing; else drop segment and return.
12149 	 */
12150 	if ((thflags & TH_ACK) == 0) {
12151 		if (tp->t_flags & TF_NEEDSYN) {
12152 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12153 			    tiwin, thflags, nxt_pkt));
12154 		} else if (tp->t_flags & TF_ACKNOW) {
12155 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
12156 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
12157 			return (ret_val);
12158 		} else {
12159 			ctf_do_drop(m, NULL);
12160 			return (0);
12161 		}
12162 	}
12163 	/*
12164 	 * case TCPS_LAST_ACK: Ack processing.
12165 	 */
12166 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
12167 		return (ret_val);
12168 	}
12169 	if (ourfinisacked) {
12170 		tp = tcp_close(tp);
12171 		ctf_do_drop(m, tp);
12172 		return (1);
12173 	}
12174 	if (sbavail(&so->so_snd)) {
12175 		if (ctf_progress_timeout_check(tp, true)) {
12176 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
12177 						tp, tick, PROGRESS_DROP, __LINE__);
12178 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
12179 			return (1);
12180 		}
12181 	}
12182 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12183 	    tiwin, thflags, nxt_pkt));
12184 }
12185 
12186 /*
12187  * Return value of 1, the TCB is unlocked and most
12188  * likely gone, return value of 0, the TCP is still
12189  * locked.
12190  */
12191 static int
12192 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, struct socket *so,
12193     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12194     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
12195 {
12196 	int32_t ret_val = 0;
12197 	int32_t ourfinisacked = 0;
12198 	struct tcp_rack *rack;
12199 
12200 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12201 	ctf_calc_rwin(so, tp);
12202 
12203 	/* Reset receive buffer auto scaling when not in bulk receive mode. */
12204 	if ((thflags & TH_RST) ||
12205 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
12206 		return (__ctf_process_rst(m, th, so, tp,
12207 					  &rack->r_ctl.challenge_ack_ts,
12208 					  &rack->r_ctl.challenge_ack_cnt));
12209 	/*
12210 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
12211 	 * synchronized state.
12212 	 */
12213 	if (thflags & TH_SYN) {
12214 		ctf_challenge_ack(m, th, tp, iptos, &ret_val);
12215 		return (ret_val);
12216 	}
12217 	/*
12218 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
12219 	 * it's less than ts_recent, drop it.
12220 	 */
12221 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
12222 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
12223 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
12224 			return (ret_val);
12225 	}
12226 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
12227 			      &rack->r_ctl.challenge_ack_ts,
12228 			      &rack->r_ctl.challenge_ack_cnt)) {
12229 		return (ret_val);
12230 	}
12231 	/*
12232 	 * If new data are received on a connection after the user processes
12233 	 * are gone, then RST the other end.
12234 	 */
12235 	if ((tp->t_flags & TF_CLOSED) && tlen &&
12236 	    rack_check_data_after_close(m, tp, &tlen, th, so))
12237 		return (1);
12238 	/*
12239 	 * If last ACK falls within this segment's sequence numbers, record
12240 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
12241 	 * from the latest proposal of the tcplw@cray.com list (Braden
12242 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
12243 	 * with our earlier PAWS tests, so this check should be solely
12244 	 * predicated on the sequence space of this segment. 3) That we
12245 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
12246 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
12247 	 * SEG.Len, This modified check allows us to overcome RFC1323's
12248 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
12249 	 * p.869. In such cases, we can still calculate the RTT correctly
12250 	 * when RCV.NXT == Last.ACK.Sent.
12251 	 */
12252 	if ((to->to_flags & TOF_TS) != 0 &&
12253 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
12254 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
12255 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
12256 		tp->ts_recent_age = tcp_ts_getticks();
12257 		tp->ts_recent = to->to_tsval;
12258 	}
12259 	/*
12260 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
12261 	 * is on (half-synchronized state), then queue data for later
12262 	 * processing; else drop segment and return.
12263 	 */
12264 	if ((thflags & TH_ACK) == 0) {
12265 		if (tp->t_flags & TF_NEEDSYN) {
12266 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12267 			    tiwin, thflags, nxt_pkt));
12268 		} else if (tp->t_flags & TF_ACKNOW) {
12269 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
12270 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
12271 			return (ret_val);
12272 		} else {
12273 			ctf_do_drop(m, NULL);
12274 			return (0);
12275 		}
12276 	}
12277 	/*
12278 	 * Ack processing.
12279 	 */
12280 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
12281 		return (ret_val);
12282 	}
12283 	if (sbavail(&so->so_snd)) {
12284 		if (ctf_progress_timeout_check(tp, true)) {
12285 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
12286 						tp, tick, PROGRESS_DROP, __LINE__);
12287 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
12288 			return (1);
12289 		}
12290 	}
12291 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12292 	    tiwin, thflags, nxt_pkt));
12293 }
12294 
12295 static void inline
12296 rack_clear_rate_sample(struct tcp_rack *rack)
12297 {
12298 	rack->r_ctl.rack_rs.rs_flags = RACK_RTT_EMPTY;
12299 	rack->r_ctl.rack_rs.rs_rtt_cnt = 0;
12300 	rack->r_ctl.rack_rs.rs_rtt_tot = 0;
12301 }
12302 
12303 static void
12304 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line, uint64_t *fill_override)
12305 {
12306 	uint64_t bw_est, rate_wanted;
12307 	int chged = 0;
12308 	uint32_t user_max, orig_min, orig_max;
12309 
12310 	orig_min = rack->r_ctl.rc_pace_min_segs;
12311 	orig_max = rack->r_ctl.rc_pace_max_segs;
12312 	user_max = ctf_fixed_maxseg(tp) * rack->rc_user_set_max_segs;
12313 	if (ctf_fixed_maxseg(tp) != rack->r_ctl.rc_pace_min_segs)
12314 		chged = 1;
12315 	rack->r_ctl.rc_pace_min_segs = ctf_fixed_maxseg(tp);
12316 	if (rack->use_fixed_rate || rack->rc_force_max_seg) {
12317 		if (user_max != rack->r_ctl.rc_pace_max_segs)
12318 			chged = 1;
12319 	}
12320 	if (rack->rc_force_max_seg) {
12321 		rack->r_ctl.rc_pace_max_segs = user_max;
12322 	} else if (rack->use_fixed_rate) {
12323 		bw_est = rack_get_bw(rack);
12324 		if ((rack->r_ctl.crte == NULL) ||
12325 		    (bw_est != rack->r_ctl.crte->rate)) {
12326 			rack->r_ctl.rc_pace_max_segs = user_max;
12327 		} else {
12328 			/* We are pacing right at the hardware rate */
12329 			uint32_t segsiz;
12330 
12331 			segsiz = min(ctf_fixed_maxseg(tp),
12332 				     rack->r_ctl.rc_pace_min_segs);
12333 			rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(
12334 				                           tp, bw_est, segsiz, 0,
12335 							   rack->r_ctl.crte, NULL);
12336 		}
12337 	} else if (rack->rc_always_pace) {
12338 		if (rack->r_ctl.gp_bw ||
12339 #ifdef NETFLIX_PEAKRATE
12340 		    rack->rc_tp->t_maxpeakrate ||
12341 #endif
12342 		    rack->r_ctl.init_rate) {
12343 			/* We have a rate of some sort set */
12344 			uint32_t  orig;
12345 
12346 			bw_est = rack_get_bw(rack);
12347 			orig = rack->r_ctl.rc_pace_max_segs;
12348 			if (fill_override)
12349 				rate_wanted = *fill_override;
12350 			else
12351 				rate_wanted = rack_get_output_bw(rack, bw_est, NULL, NULL);
12352 			if (rate_wanted) {
12353 				/* We have something */
12354 				rack->r_ctl.rc_pace_max_segs = rack_get_pacing_len(rack,
12355 										   rate_wanted,
12356 										   ctf_fixed_maxseg(rack->rc_tp));
12357 			} else
12358 				rack->r_ctl.rc_pace_max_segs = rack->r_ctl.rc_pace_min_segs;
12359 			if (orig != rack->r_ctl.rc_pace_max_segs)
12360 				chged = 1;
12361 		} else if ((rack->r_ctl.gp_bw == 0) &&
12362 			   (rack->r_ctl.rc_pace_max_segs == 0)) {
12363 			/*
12364 			 * If we have nothing limit us to bursting
12365 			 * out IW sized pieces.
12366 			 */
12367 			chged = 1;
12368 			rack->r_ctl.rc_pace_max_segs = rc_init_window(rack);
12369 		}
12370 	}
12371 	if (rack->r_ctl.rc_pace_max_segs > PACE_MAX_IP_BYTES) {
12372 		chged = 1;
12373 		rack->r_ctl.rc_pace_max_segs = PACE_MAX_IP_BYTES;
12374 	}
12375 	if (chged)
12376 		rack_log_type_pacing_sizes(tp, rack, orig_min, orig_max, line, 2);
12377 }
12378 
12379 
12380 static void
12381 rack_init_fsb_block(struct tcpcb *tp, struct tcp_rack *rack)
12382 {
12383 #ifdef INET6
12384 	struct ip6_hdr *ip6 = NULL;
12385 #endif
12386 #ifdef INET
12387 	struct ip *ip = NULL;
12388 #endif
12389 	struct udphdr *udp = NULL;
12390 
12391 	/* Ok lets fill in the fast block, it can only be used with no IP options! */
12392 #ifdef INET6
12393 	if (rack->r_is_v6) {
12394 		rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
12395 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
12396 		if (tp->t_port) {
12397 			rack->r_ctl.fsb.tcp_ip_hdr_len += sizeof(struct udphdr);
12398 			udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
12399 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
12400 			udp->uh_dport = tp->t_port;
12401 			rack->r_ctl.fsb.udp = udp;
12402 			rack->r_ctl.fsb.th = (struct tcphdr *)(udp + 1);
12403 		} else
12404 		{
12405 			rack->r_ctl.fsb.th = (struct tcphdr *)(ip6 + 1);
12406 			rack->r_ctl.fsb.udp = NULL;
12407 		}
12408 		tcpip_fillheaders(rack->rc_inp,
12409 				  tp->t_port,
12410 				  ip6, rack->r_ctl.fsb.th);
12411 	} else
12412 #endif				/* INET6 */
12413 	{
12414 		rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct tcpiphdr);
12415 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
12416 		if (tp->t_port) {
12417 			rack->r_ctl.fsb.tcp_ip_hdr_len += sizeof(struct udphdr);
12418 			udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
12419 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
12420 			udp->uh_dport = tp->t_port;
12421 			rack->r_ctl.fsb.udp = udp;
12422 			rack->r_ctl.fsb.th = (struct tcphdr *)(udp + 1);
12423 		} else
12424 		{
12425 			rack->r_ctl.fsb.udp = NULL;
12426 			rack->r_ctl.fsb.th = (struct tcphdr *)(ip + 1);
12427 		}
12428 		tcpip_fillheaders(rack->rc_inp,
12429 				  tp->t_port,
12430 				  ip, rack->r_ctl.fsb.th);
12431 	}
12432 	rack->r_fsb_inited = 1;
12433 }
12434 
12435 static int
12436 rack_init_fsb(struct tcpcb *tp, struct tcp_rack *rack)
12437 {
12438 	/*
12439 	 * Allocate the larger of spaces V6 if available else just
12440 	 * V4 and include udphdr (overbook)
12441 	 */
12442 #ifdef INET6
12443 	rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + sizeof(struct udphdr);
12444 #else
12445 	rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct tcpiphdr) + sizeof(struct udphdr);
12446 #endif
12447 	rack->r_ctl.fsb.tcp_ip_hdr = malloc(rack->r_ctl.fsb.tcp_ip_hdr_len,
12448 					    M_TCPFSB, M_NOWAIT|M_ZERO);
12449 	if (rack->r_ctl.fsb.tcp_ip_hdr == NULL) {
12450 		return (ENOMEM);
12451 	}
12452 	rack->r_fsb_inited = 0;
12453 	return (0);
12454 }
12455 
12456 static int
12457 rack_init(struct tcpcb *tp)
12458 {
12459 	struct inpcb *inp = tptoinpcb(tp);
12460 	struct tcp_rack *rack = NULL;
12461 #ifdef INVARIANTS
12462 	struct rack_sendmap *insret;
12463 #endif
12464 	uint32_t iwin, snt, us_cts;
12465 	int err;
12466 
12467 	tp->t_fb_ptr = uma_zalloc(rack_pcb_zone, M_NOWAIT);
12468 	if (tp->t_fb_ptr == NULL) {
12469 		/*
12470 		 * We need to allocate memory but cant. The INP and INP_INFO
12471 		 * locks and they are recursive (happens during setup. So a
12472 		 * scheme to drop the locks fails :(
12473 		 *
12474 		 */
12475 		return (ENOMEM);
12476 	}
12477 	memset(tp->t_fb_ptr, 0, sizeof(struct tcp_rack));
12478 
12479 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12480 	RB_INIT(&rack->r_ctl.rc_mtree);
12481 	TAILQ_INIT(&rack->r_ctl.rc_free);
12482 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
12483 	rack->rc_tp = tp;
12484 	rack->rc_inp = inp;
12485 	/* Set the flag */
12486 	rack->r_is_v6 = (inp->inp_vflag & INP_IPV6) != 0;
12487 	/* Probably not needed but lets be sure */
12488 	rack_clear_rate_sample(rack);
12489 	/*
12490 	 * Save off the default values, socket options will poke
12491 	 * at these if pacing is not on or we have not yet
12492 	 * reached where pacing is on (gp_ready/fixed enabled).
12493 	 * When they get set into the CC module (when gp_ready
12494 	 * is enabled or we enable fixed) then we will set these
12495 	 * values into the CC and place in here the old values
12496 	 * so we have a restoral. Then we will set the flag
12497 	 * rc_pacing_cc_set. That way whenever we turn off pacing
12498 	 * or switch off this stack, we will know to go restore
12499 	 * the saved values.
12500 	 */
12501 	rack->r_ctl.rc_saved_beta.beta = V_newreno_beta_ecn;
12502 	rack->r_ctl.rc_saved_beta.beta_ecn = V_newreno_beta_ecn;
12503 	/* We want abe like behavior as well */
12504 	rack->r_ctl.rc_saved_beta.newreno_flags |= CC_NEWRENO_BETA_ECN_ENABLED;
12505 	rack->r_ctl.rc_reorder_fade = rack_reorder_fade;
12506 	rack->rc_allow_data_af_clo = rack_ignore_data_after_close;
12507 	rack->r_ctl.rc_tlp_threshold = rack_tlp_thresh;
12508 	rack->r_ctl.roundends = tp->snd_max;
12509 	if (use_rack_rr)
12510 		rack->use_rack_rr = 1;
12511 	if (V_tcp_delack_enabled)
12512 		tp->t_delayed_ack = 1;
12513 	else
12514 		tp->t_delayed_ack = 0;
12515 #ifdef TCP_ACCOUNTING
12516 	if (rack_tcp_accounting) {
12517 		tp->t_flags2 |= TF2_TCP_ACCOUNTING;
12518 	}
12519 #endif
12520 	if (rack_enable_shared_cwnd)
12521 		rack->rack_enable_scwnd = 1;
12522 	rack->rc_user_set_max_segs = rack_hptsi_segments;
12523 	rack->rc_force_max_seg = 0;
12524 	if (rack_use_imac_dack)
12525 		rack->rc_dack_mode = 1;
12526 	TAILQ_INIT(&rack->r_ctl.opt_list);
12527 	rack->r_ctl.rc_reorder_shift = rack_reorder_thresh;
12528 	rack->r_ctl.rc_pkt_delay = rack_pkt_delay;
12529 	rack->r_ctl.rc_tlp_cwnd_reduce = rack_lower_cwnd_at_tlp;
12530 	rack->r_ctl.rc_lowest_us_rtt = 0xffffffff;
12531 	rack->r_ctl.rc_highest_us_rtt = 0;
12532 	rack->r_ctl.bw_rate_cap = rack_bw_rate_cap;
12533 	rack->r_ctl.timer_slop = TICKS_2_USEC(tcp_rexmit_slop);
12534 	if (rack_use_cmp_acks)
12535 		rack->r_use_cmp_ack = 1;
12536 	if (rack_disable_prr)
12537 		rack->rack_no_prr = 1;
12538 	if (rack_gp_no_rec_chg)
12539 		rack->rc_gp_no_rec_chg = 1;
12540 	if (rack_pace_every_seg && tcp_can_enable_pacing()) {
12541 		rack->rc_always_pace = 1;
12542 		if (rack->use_fixed_rate || rack->gp_ready)
12543 			rack_set_cc_pacing(rack);
12544 	} else
12545 		rack->rc_always_pace = 0;
12546 	if (rack_enable_mqueue_for_nonpaced || rack->r_use_cmp_ack)
12547 		rack->r_mbuf_queue = 1;
12548 	else
12549 		rack->r_mbuf_queue = 0;
12550 	if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
12551 		inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
12552 	else
12553 		inp->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
12554 	rack_set_pace_segments(tp, rack, __LINE__, NULL);
12555 	if (rack_limits_scwnd)
12556 		rack->r_limit_scw = 1;
12557 	else
12558 		rack->r_limit_scw = 0;
12559 	rack->rc_labc = V_tcp_abc_l_var;
12560 	rack->r_ctl.rc_high_rwnd = tp->snd_wnd;
12561 	rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
12562 	rack->r_ctl.rc_rate_sample_method = rack_rate_sample_method;
12563 	rack->rack_tlp_threshold_use = rack_tlp_threshold_use;
12564 	rack->r_ctl.rc_prr_sendalot = rack_send_a_lot_in_prr;
12565 	rack->r_ctl.rc_min_to = rack_min_to;
12566 	microuptime(&rack->r_ctl.act_rcv_time);
12567 	rack->r_ctl.rc_last_time_decay = rack->r_ctl.act_rcv_time;
12568 	rack->rc_init_win = rack_default_init_window;
12569 	rack->r_ctl.rack_per_of_gp_ss = rack_per_of_gp_ss;
12570 	if (rack_hw_up_only)
12571 		rack->r_up_only = 1;
12572 	if (rack_do_dyn_mul) {
12573 		/* When dynamic adjustment is on CA needs to start at 100% */
12574 		rack->rc_gp_dyn_mul = 1;
12575 		if (rack_do_dyn_mul >= 100)
12576 			rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
12577 	} else
12578 		rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
12579 	rack->r_ctl.rack_per_of_gp_rec = rack_per_of_gp_rec;
12580 	rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
12581 	rack->r_ctl.rc_tlp_rxt_last_time = tcp_tv_to_mssectick(&rack->r_ctl.act_rcv_time);
12582 	setup_time_filter_small(&rack->r_ctl.rc_gp_min_rtt, FILTER_TYPE_MIN,
12583 				rack_probertt_filter_life);
12584 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
12585 	rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
12586 	rack->r_ctl.rc_time_of_last_probertt = us_cts;
12587 	rack->r_ctl.challenge_ack_ts = tcp_ts_getticks();
12588 	rack->r_ctl.rc_time_probertt_starts = 0;
12589 	if (rack_dsack_std_based & 0x1) {
12590 		/* Basically this means all rack timers are at least (srtt + 1/4 srtt) */
12591 		rack->rc_rack_tmr_std_based = 1;
12592 	}
12593 	if (rack_dsack_std_based & 0x2) {
12594 		/* Basically this means  rack timers are extended based on dsack by up to (2 * srtt) */
12595 		rack->rc_rack_use_dsack = 1;
12596 	}
12597 	/* We require at least one measurement, even if the sysctl is 0 */
12598 	if (rack_req_measurements)
12599 		rack->r_ctl.req_measurements = rack_req_measurements;
12600 	else
12601 		rack->r_ctl.req_measurements = 1;
12602 	if (rack_enable_hw_pacing)
12603 		rack->rack_hdw_pace_ena = 1;
12604 	if (rack_hw_rate_caps)
12605 		rack->r_rack_hw_rate_caps = 1;
12606 	/* Do we force on detection? */
12607 #ifdef NETFLIX_EXP_DETECTION
12608 	if (tcp_force_detection)
12609 		rack->do_detection = 1;
12610 	else
12611 #endif
12612 		rack->do_detection = 0;
12613 	if (rack_non_rxt_use_cr)
12614 		rack->rack_rec_nonrxt_use_cr = 1;
12615 	err = rack_init_fsb(tp, rack);
12616 	if (err) {
12617 		uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
12618 		tp->t_fb_ptr = NULL;
12619 		return (err);
12620 	}
12621 	if (tp->snd_una != tp->snd_max) {
12622 		/* Create a send map for the current outstanding data */
12623 		struct rack_sendmap *rsm;
12624 
12625 		rsm = rack_alloc(rack);
12626 		if (rsm == NULL) {
12627 			uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
12628 			tp->t_fb_ptr = NULL;
12629 			return (ENOMEM);
12630 		}
12631 		rsm->r_no_rtt_allowed = 1;
12632 		rsm->r_tim_lastsent[0] = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
12633 		rsm->r_rtr_cnt = 1;
12634 		rsm->r_rtr_bytes = 0;
12635 		if (tp->t_flags & TF_SENTFIN)
12636 			rsm->r_flags |= RACK_HAS_FIN;
12637 		if ((tp->snd_una == tp->iss) &&
12638 		    !TCPS_HAVEESTABLISHED(tp->t_state))
12639 			rsm->r_flags |= RACK_HAS_SYN;
12640 		rsm->r_start = tp->snd_una;
12641 		rsm->r_end = tp->snd_max;
12642 		rsm->r_dupack = 0;
12643 		if (rack->rc_inp->inp_socket->so_snd.sb_mb != NULL) {
12644 			rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd, 0, &rsm->soff);
12645 			if (rsm->m)
12646 				rsm->orig_m_len = rsm->m->m_len;
12647 			else
12648 				rsm->orig_m_len = 0;
12649 		} else {
12650 			/*
12651 			 * This can happen if we have a stand-alone FIN or
12652 			 *  SYN.
12653 			 */
12654 			rsm->m = NULL;
12655 			rsm->orig_m_len = 0;
12656 			rsm->soff = 0;
12657 		}
12658 #ifndef INVARIANTS
12659 		(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
12660 #else
12661 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
12662 		if (insret != NULL) {
12663 			panic("Insert in rb tree fails ret:%p rack:%p rsm:%p",
12664 			      insret, rack, rsm);
12665 		}
12666 #endif
12667 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
12668 		rsm->r_in_tmap = 1;
12669 	}
12670 	/*
12671 	 * Timers in Rack are kept in microseconds so lets
12672 	 * convert any initial incoming variables
12673 	 * from ticks into usecs. Note that we
12674 	 * also change the values of t_srtt and t_rttvar, if
12675 	 * they are non-zero. They are kept with a 5
12676 	 * bit decimal so we have to carefully convert
12677 	 * these to get the full precision.
12678 	 */
12679 	rack_convert_rtts(tp);
12680 	tp->t_rttlow = TICKS_2_USEC(tp->t_rttlow);
12681 	if (rack_do_hystart) {
12682 		tp->t_ccv.flags |= CCF_HYSTART_ALLOWED;
12683 		if (rack_do_hystart > 1)
12684 			tp->t_ccv.flags |= CCF_HYSTART_CAN_SH_CWND;
12685 		if (rack_do_hystart > 2)
12686 			tp->t_ccv.flags |= CCF_HYSTART_CONS_SSTH;
12687 	}
12688 	if (rack_def_profile)
12689 		rack_set_profile(rack, rack_def_profile);
12690 	/* Cancel the GP measurement in progress */
12691 	tp->t_flags &= ~TF_GPUTINPROG;
12692 	if (SEQ_GT(tp->snd_max, tp->iss))
12693 		snt = tp->snd_max - tp->iss;
12694 	else
12695 		snt = 0;
12696 	iwin = rc_init_window(rack);
12697 	if (snt < iwin) {
12698 		/* We are not past the initial window
12699 		 * so we need to make sure cwnd is
12700 		 * correct.
12701 		 */
12702 		if (tp->snd_cwnd < iwin)
12703 			tp->snd_cwnd = iwin;
12704 		/*
12705 		 * If we are within the initial window
12706 		 * we want ssthresh to be unlimited. Setting
12707 		 * it to the rwnd (which the default stack does
12708 		 * and older racks) is not really a good idea
12709 		 * since we want to be in SS and grow both the
12710 		 * cwnd and the rwnd (via dynamic rwnd growth). If
12711 		 * we set it to the rwnd then as the peer grows its
12712 		 * rwnd we will be stuck in CA and never hit SS.
12713 		 *
12714 		 * Its far better to raise it up high (this takes the
12715 		 * risk that there as been a loss already, probably
12716 		 * we should have an indicator in all stacks of loss
12717 		 * but we don't), but considering the normal use this
12718 		 * is a risk worth taking. The consequences of not
12719 		 * hitting SS are far worse than going one more time
12720 		 * into it early on (before we have sent even a IW).
12721 		 * It is highly unlikely that we will have had a loss
12722 		 * before getting the IW out.
12723 		 */
12724 		tp->snd_ssthresh = 0xffffffff;
12725 	}
12726 	rack_stop_all_timers(tp);
12727 	/* Lets setup the fsb block */
12728 	rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
12729 	rack_log_rtt_shrinks(rack,  us_cts,  tp->t_rxtcur,
12730 			     __LINE__, RACK_RTTS_INIT);
12731 	return (0);
12732 }
12733 
12734 static int
12735 rack_handoff_ok(struct tcpcb *tp)
12736 {
12737 	if ((tp->t_state == TCPS_CLOSED) ||
12738 	    (tp->t_state == TCPS_LISTEN)) {
12739 		/* Sure no problem though it may not stick */
12740 		return (0);
12741 	}
12742 	if ((tp->t_state == TCPS_SYN_SENT) ||
12743 	    (tp->t_state == TCPS_SYN_RECEIVED)) {
12744 		/*
12745 		 * We really don't know if you support sack,
12746 		 * you have to get to ESTAB or beyond to tell.
12747 		 */
12748 		return (EAGAIN);
12749 	}
12750 	if ((tp->t_flags & TF_SENTFIN) && ((tp->snd_max - tp->snd_una) > 1)) {
12751 		/*
12752 		 * Rack will only send a FIN after all data is acknowledged.
12753 		 * So in this case we have more data outstanding. We can't
12754 		 * switch stacks until either all data and only the FIN
12755 		 * is left (in which case rack_init() now knows how
12756 		 * to deal with that) <or> all is acknowledged and we
12757 		 * are only left with incoming data, though why you
12758 		 * would want to switch to rack after all data is acknowledged
12759 		 * I have no idea (rrs)!
12760 		 */
12761 		return (EAGAIN);
12762 	}
12763 	if ((tp->t_flags & TF_SACK_PERMIT) || rack_sack_not_required){
12764 		return (0);
12765 	}
12766 	/*
12767 	 * If we reach here we don't do SACK on this connection so we can
12768 	 * never do rack.
12769 	 */
12770 	return (EINVAL);
12771 }
12772 
12773 
12774 static void
12775 rack_fini(struct tcpcb *tp, int32_t tcb_is_purged)
12776 {
12777 	struct inpcb *inp = tptoinpcb(tp);
12778 
12779 	if (tp->t_fb_ptr) {
12780 		struct tcp_rack *rack;
12781 		struct rack_sendmap *rsm, *nrsm;
12782 #ifdef INVARIANTS
12783 		struct rack_sendmap *rm;
12784 #endif
12785 
12786 		rack = (struct tcp_rack *)tp->t_fb_ptr;
12787 		if (tp->t_in_pkt) {
12788 			/*
12789 			 * It is unsafe to process the packets since a
12790 			 * reset may be lurking in them (its rare but it
12791 			 * can occur). If we were to find a RST, then we
12792 			 * would end up dropping the connection and the
12793 			 * INP lock, so when we return the caller (tcp_usrreq)
12794 			 * will blow up when it trys to unlock the inp.
12795 			 */
12796 			struct mbuf *save, *m;
12797 
12798 			m = tp->t_in_pkt;
12799 			tp->t_in_pkt = NULL;
12800 			tp->t_tail_pkt = NULL;
12801 			while (m) {
12802 				save = m->m_nextpkt;
12803 				m->m_nextpkt = NULL;
12804 				m_freem(m);
12805 				m = save;
12806 			}
12807 		}
12808 		tp->t_flags &= ~TF_FORCEDATA;
12809 #ifdef NETFLIX_SHARED_CWND
12810 		if (rack->r_ctl.rc_scw) {
12811 			uint32_t limit;
12812 
12813 			if (rack->r_limit_scw)
12814 				limit = max(1, rack->r_ctl.rc_lowest_us_rtt);
12815 			else
12816 				limit = 0;
12817 			tcp_shared_cwnd_free_full(tp, rack->r_ctl.rc_scw,
12818 						  rack->r_ctl.rc_scw_index,
12819 						  limit);
12820 			rack->r_ctl.rc_scw = NULL;
12821 		}
12822 #endif
12823 		if (rack->r_ctl.fsb.tcp_ip_hdr) {
12824 			free(rack->r_ctl.fsb.tcp_ip_hdr, M_TCPFSB);
12825 			rack->r_ctl.fsb.tcp_ip_hdr = NULL;
12826 			rack->r_ctl.fsb.th = NULL;
12827 		}
12828 		/* Convert back to ticks, with  */
12829 		if (tp->t_srtt > 1) {
12830 			uint32_t val, frac;
12831 
12832 			val = USEC_2_TICKS(tp->t_srtt);
12833 			frac = tp->t_srtt % (HPTS_USEC_IN_SEC / hz);
12834 			tp->t_srtt = val << TCP_RTT_SHIFT;
12835 			/*
12836 			 * frac is the fractional part here is left
12837 			 * over from converting to hz and shifting.
12838 			 * We need to convert this to the 5 bit
12839 			 * remainder.
12840 			 */
12841 			if (frac) {
12842 				if (hz == 1000) {
12843 					frac = (((uint64_t)frac *  (uint64_t)TCP_RTT_SCALE) / (uint64_t)HPTS_USEC_IN_MSEC);
12844 				} else {
12845 					frac = (((uint64_t)frac * (uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE) /(uint64_t)HPTS_USEC_IN_SEC);
12846 				}
12847 				tp->t_srtt += frac;
12848 			}
12849 		}
12850 		if (tp->t_rttvar) {
12851 			uint32_t val, frac;
12852 
12853 			val = USEC_2_TICKS(tp->t_rttvar);
12854 			frac = tp->t_srtt % (HPTS_USEC_IN_SEC / hz);
12855 			tp->t_rttvar = val <<  TCP_RTTVAR_SHIFT;
12856 			/*
12857 			 * frac is the fractional part here is left
12858 			 * over from converting to hz and shifting.
12859 			 * We need to convert this to the 5 bit
12860 			 * remainder.
12861 			 */
12862 			if (frac) {
12863 				if (hz == 1000) {
12864 					frac = (((uint64_t)frac *  (uint64_t)TCP_RTT_SCALE) / (uint64_t)HPTS_USEC_IN_MSEC);
12865 				} else {
12866 					frac = (((uint64_t)frac * (uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE) /(uint64_t)HPTS_USEC_IN_SEC);
12867 				}
12868 				tp->t_rttvar += frac;
12869 			}
12870 		}
12871 		tp->t_rxtcur = USEC_2_TICKS(tp->t_rxtcur);
12872 		tp->t_rttlow = USEC_2_TICKS(tp->t_rttlow);
12873 		if (rack->rc_always_pace) {
12874 			tcp_decrement_paced_conn();
12875 			rack_undo_cc_pacing(rack);
12876 			rack->rc_always_pace = 0;
12877 		}
12878 		/* Clean up any options if they were not applied */
12879 		while (!TAILQ_EMPTY(&rack->r_ctl.opt_list)) {
12880 			struct deferred_opt_list *dol;
12881 
12882 			dol = TAILQ_FIRST(&rack->r_ctl.opt_list);
12883 			TAILQ_REMOVE(&rack->r_ctl.opt_list, dol, next);
12884 			free(dol, M_TCPDO);
12885 		}
12886 		/* rack does not use force data but other stacks may clear it */
12887 		if (rack->r_ctl.crte != NULL) {
12888 			tcp_rel_pacing_rate(rack->r_ctl.crte, tp);
12889 			rack->rack_hdrw_pacing = 0;
12890 			rack->r_ctl.crte = NULL;
12891 		}
12892 #ifdef TCP_BLACKBOX
12893 		tcp_log_flowend(tp);
12894 #endif
12895 		RB_FOREACH_SAFE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm) {
12896 #ifndef INVARIANTS
12897 			(void)RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
12898 #else
12899 			rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
12900 			if (rm != rsm) {
12901 				panic("At fini, rack:%p rsm:%p rm:%p",
12902 				      rack, rsm, rm);
12903 			}
12904 #endif
12905 			uma_zfree(rack_zone, rsm);
12906 		}
12907 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
12908 		while (rsm) {
12909 			TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
12910 			uma_zfree(rack_zone, rsm);
12911 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
12912 		}
12913 		rack->rc_free_cnt = 0;
12914 		uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
12915 		tp->t_fb_ptr = NULL;
12916 	}
12917 	inp->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
12918 	inp->inp_flags2 &= ~INP_MBUF_QUEUE_READY;
12919 	inp->inp_flags2 &= ~INP_DONT_SACK_QUEUE;
12920 	inp->inp_flags2 &= ~INP_MBUF_ACKCMP;
12921 	/* Cancel the GP measurement in progress */
12922 	tp->t_flags &= ~TF_GPUTINPROG;
12923 	inp->inp_flags2 &= ~INP_MBUF_L_ACKS;
12924 	/* Make sure snd_nxt is correctly set */
12925 	tp->snd_nxt = tp->snd_max;
12926 }
12927 
12928 static void
12929 rack_set_state(struct tcpcb *tp, struct tcp_rack *rack)
12930 {
12931 	if ((rack->r_state == TCPS_CLOSED) && (tp->t_state != TCPS_CLOSED)) {
12932 		rack->r_is_v6 = (tptoinpcb(tp)->inp_vflag & INP_IPV6) != 0;
12933 	}
12934 	switch (tp->t_state) {
12935 	case TCPS_SYN_SENT:
12936 		rack->r_state = TCPS_SYN_SENT;
12937 		rack->r_substate = rack_do_syn_sent;
12938 		break;
12939 	case TCPS_SYN_RECEIVED:
12940 		rack->r_state = TCPS_SYN_RECEIVED;
12941 		rack->r_substate = rack_do_syn_recv;
12942 		break;
12943 	case TCPS_ESTABLISHED:
12944 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
12945 		rack->r_state = TCPS_ESTABLISHED;
12946 		rack->r_substate = rack_do_established;
12947 		break;
12948 	case TCPS_CLOSE_WAIT:
12949 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
12950 		rack->r_state = TCPS_CLOSE_WAIT;
12951 		rack->r_substate = rack_do_close_wait;
12952 		break;
12953 	case TCPS_FIN_WAIT_1:
12954 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
12955 		rack->r_state = TCPS_FIN_WAIT_1;
12956 		rack->r_substate = rack_do_fin_wait_1;
12957 		break;
12958 	case TCPS_CLOSING:
12959 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
12960 		rack->r_state = TCPS_CLOSING;
12961 		rack->r_substate = rack_do_closing;
12962 		break;
12963 	case TCPS_LAST_ACK:
12964 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
12965 		rack->r_state = TCPS_LAST_ACK;
12966 		rack->r_substate = rack_do_lastack;
12967 		break;
12968 	case TCPS_FIN_WAIT_2:
12969 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
12970 		rack->r_state = TCPS_FIN_WAIT_2;
12971 		rack->r_substate = rack_do_fin_wait_2;
12972 		break;
12973 	case TCPS_LISTEN:
12974 	case TCPS_CLOSED:
12975 	case TCPS_TIME_WAIT:
12976 	default:
12977 		break;
12978 	};
12979 	if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
12980 		rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
12981 
12982 }
12983 
12984 static void
12985 rack_timer_audit(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb)
12986 {
12987 	/*
12988 	 * We received an ack, and then did not
12989 	 * call send or were bounced out due to the
12990 	 * hpts was running. Now a timer is up as well, is
12991 	 * it the right timer?
12992 	 */
12993 	struct rack_sendmap *rsm;
12994 	int tmr_up;
12995 
12996 	tmr_up = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
12997 	if (rack->rc_in_persist && (tmr_up == PACE_TMR_PERSIT))
12998 		return;
12999 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
13000 	if (((rsm == NULL) || (tp->t_state < TCPS_ESTABLISHED)) &&
13001 	    (tmr_up == PACE_TMR_RXT)) {
13002 		/* Should be an RXT */
13003 		return;
13004 	}
13005 	if (rsm == NULL) {
13006 		/* Nothing outstanding? */
13007 		if (tp->t_flags & TF_DELACK) {
13008 			if (tmr_up == PACE_TMR_DELACK)
13009 				/* We are supposed to have delayed ack up and we do */
13010 				return;
13011 		} else if (sbavail(&tptosocket(tp)->so_snd) && (tmr_up == PACE_TMR_RXT)) {
13012 			/*
13013 			 * if we hit enobufs then we would expect the possibility
13014 			 * of nothing outstanding and the RXT up (and the hptsi timer).
13015 			 */
13016 			return;
13017 		} else if (((V_tcp_always_keepalive ||
13018 			     rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
13019 			    (tp->t_state <= TCPS_CLOSING)) &&
13020 			   (tmr_up == PACE_TMR_KEEP) &&
13021 			   (tp->snd_max == tp->snd_una)) {
13022 			/* We should have keep alive up and we do */
13023 			return;
13024 		}
13025 	}
13026 	if (SEQ_GT(tp->snd_max, tp->snd_una) &&
13027 		   ((tmr_up == PACE_TMR_TLP) ||
13028 		    (tmr_up == PACE_TMR_RACK) ||
13029 		    (tmr_up == PACE_TMR_RXT))) {
13030 		/*
13031 		 * Either a Rack, TLP or RXT is fine if  we
13032 		 * have outstanding data.
13033 		 */
13034 		return;
13035 	} else if (tmr_up == PACE_TMR_DELACK) {
13036 		/*
13037 		 * If the delayed ack was going to go off
13038 		 * before the rtx/tlp/rack timer were going to
13039 		 * expire, then that would be the timer in control.
13040 		 * Note we don't check the time here trusting the
13041 		 * code is correct.
13042 		 */
13043 		return;
13044 	}
13045 	/*
13046 	 * Ok the timer originally started is not what we want now.
13047 	 * We will force the hpts to be stopped if any, and restart
13048 	 * with the slot set to what was in the saved slot.
13049 	 */
13050 	if (tcp_in_hpts(rack->rc_inp)) {
13051 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
13052 			uint32_t us_cts;
13053 
13054 			us_cts = tcp_get_usecs(NULL);
13055 			if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
13056 				rack->r_early = 1;
13057 				rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
13058 			}
13059 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
13060 		}
13061 		tcp_hpts_remove(rack->rc_inp);
13062 	}
13063 	rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13064 	rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
13065 }
13066 
13067 
13068 static void
13069 rack_do_win_updates(struct tcpcb *tp, struct tcp_rack *rack, uint32_t tiwin, uint32_t seq, uint32_t ack, uint32_t cts, uint32_t high_seq)
13070 {
13071 	if ((SEQ_LT(tp->snd_wl1, seq) ||
13072 	    (tp->snd_wl1 == seq && (SEQ_LT(tp->snd_wl2, ack) ||
13073 	    (tp->snd_wl2 == ack && tiwin > tp->snd_wnd))))) {
13074 		/* keep track of pure window updates */
13075 		if ((tp->snd_wl2 == ack) && (tiwin > tp->snd_wnd))
13076 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
13077 		tp->snd_wnd = tiwin;
13078 		rack_validate_fo_sendwin_up(tp, rack);
13079 		tp->snd_wl1 = seq;
13080 		tp->snd_wl2 = ack;
13081 		if (tp->snd_wnd > tp->max_sndwnd)
13082 			tp->max_sndwnd = tp->snd_wnd;
13083 	    rack->r_wanted_output = 1;
13084 	} else if ((tp->snd_wl2 == ack) && (tiwin < tp->snd_wnd)) {
13085 		tp->snd_wnd = tiwin;
13086 		rack_validate_fo_sendwin_up(tp, rack);
13087 		tp->snd_wl1 = seq;
13088 		tp->snd_wl2 = ack;
13089 	} else {
13090 		/* Not a valid win update */
13091 		return;
13092 	}
13093 	/* Do we exit persists? */
13094 	if ((rack->rc_in_persist != 0) &&
13095 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
13096 				rack->r_ctl.rc_pace_min_segs))) {
13097 		rack_exit_persist(tp, rack, cts);
13098 	}
13099 	/* Do we enter persists? */
13100 	if ((rack->rc_in_persist == 0) &&
13101 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
13102 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
13103 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
13104 	    sbavail(&tptosocket(tp)->so_snd) &&
13105 	    (sbavail(&tptosocket(tp)->so_snd) > tp->snd_wnd)) {
13106 		/*
13107 		 * Here the rwnd is less than
13108 		 * the pacing size, we are established,
13109 		 * nothing is outstanding, and there is
13110 		 * data to send. Enter persists.
13111 		 */
13112 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
13113 	}
13114 }
13115 
13116 static void
13117 rack_log_input_packet(struct tcpcb *tp, struct tcp_rack *rack, struct tcp_ackent *ae, int ackval, uint32_t high_seq)
13118 {
13119 
13120 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
13121 		struct inpcb *inp = tptoinpcb(tp);
13122 		union tcp_log_stackspecific log;
13123 		struct timeval ltv;
13124 		char tcp_hdr_buf[60];
13125 		struct tcphdr *th;
13126 		struct timespec ts;
13127 		uint32_t orig_snd_una;
13128 		uint8_t xx = 0;
13129 
13130 #ifdef NETFLIX_HTTP_LOGGING
13131 		struct http_sendfile_track *http_req;
13132 
13133 		if (SEQ_GT(ae->ack, tp->snd_una)) {
13134 			http_req = tcp_http_find_req_for_seq(tp, (ae->ack-1));
13135 		} else {
13136 			http_req = tcp_http_find_req_for_seq(tp, ae->ack);
13137 		}
13138 #endif
13139 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
13140 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
13141 		if (rack->rack_no_prr == 0)
13142 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
13143 		else
13144 			log.u_bbr.flex1 = 0;
13145 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
13146 		log.u_bbr.use_lt_bw <<= 1;
13147 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
13148 		log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
13149 		log.u_bbr.inflight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
13150 		log.u_bbr.pkts_out = tp->t_maxseg;
13151 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
13152 		log.u_bbr.flex7 = 1;
13153 		log.u_bbr.lost = ae->flags;
13154 		log.u_bbr.cwnd_gain = ackval;
13155 		log.u_bbr.pacing_gain = 0x2;
13156 		if (ae->flags & TSTMP_HDWR) {
13157 			/* Record the hardware timestamp if present */
13158 			log.u_bbr.flex3 = M_TSTMP;
13159 			ts.tv_sec = ae->timestamp / 1000000000;
13160 			ts.tv_nsec = ae->timestamp % 1000000000;
13161 			ltv.tv_sec = ts.tv_sec;
13162 			ltv.tv_usec = ts.tv_nsec / 1000;
13163 			log.u_bbr.lt_epoch = tcp_tv_to_usectick(&ltv);
13164 		} else if (ae->flags & TSTMP_LRO) {
13165 			/* Record the LRO the arrival timestamp */
13166 			log.u_bbr.flex3 = M_TSTMP_LRO;
13167 			ts.tv_sec = ae->timestamp / 1000000000;
13168 			ts.tv_nsec = ae->timestamp % 1000000000;
13169 			ltv.tv_sec = ts.tv_sec;
13170 			ltv.tv_usec = ts.tv_nsec / 1000;
13171 			log.u_bbr.flex5 = tcp_tv_to_usectick(&ltv);
13172 		}
13173 		log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
13174 		/* Log the rcv time */
13175 		log.u_bbr.delRate = ae->timestamp;
13176 #ifdef NETFLIX_HTTP_LOGGING
13177 		log.u_bbr.applimited = tp->t_http_closed;
13178 		log.u_bbr.applimited <<= 8;
13179 		log.u_bbr.applimited |= tp->t_http_open;
13180 		log.u_bbr.applimited <<= 8;
13181 		log.u_bbr.applimited |= tp->t_http_req;
13182 		if (http_req) {
13183 			/* Copy out any client req info */
13184 			/* seconds */
13185 			log.u_bbr.pkt_epoch = (http_req->localtime / HPTS_USEC_IN_SEC);
13186 			/* useconds */
13187 			log.u_bbr.delivered = (http_req->localtime % HPTS_USEC_IN_SEC);
13188 			log.u_bbr.rttProp = http_req->timestamp;
13189 			log.u_bbr.cur_del_rate = http_req->start;
13190 			if (http_req->flags & TCP_HTTP_TRACK_FLG_OPEN) {
13191 				log.u_bbr.flex8 |= 1;
13192 			} else {
13193 				log.u_bbr.flex8 |= 2;
13194 				log.u_bbr.bw_inuse = http_req->end;
13195 			}
13196 			log.u_bbr.flex6 = http_req->start_seq;
13197 			if (http_req->flags & TCP_HTTP_TRACK_FLG_COMP) {
13198 				log.u_bbr.flex8 |= 4;
13199 				log.u_bbr.epoch = http_req->end_seq;
13200 			}
13201 		}
13202 #endif
13203 		memset(tcp_hdr_buf, 0, sizeof(tcp_hdr_buf));
13204 		th = (struct tcphdr *)tcp_hdr_buf;
13205 		th->th_seq = ae->seq;
13206 		th->th_ack = ae->ack;
13207 		th->th_win = ae->win;
13208 		/* Now fill in the ports */
13209 		th->th_sport = inp->inp_fport;
13210 		th->th_dport = inp->inp_lport;
13211 		tcp_set_flags(th, ae->flags);
13212 		/* Now do we have a timestamp option? */
13213 		if (ae->flags & HAS_TSTMP) {
13214 			u_char *cp;
13215 			uint32_t val;
13216 
13217 			th->th_off = ((sizeof(struct tcphdr) + TCPOLEN_TSTAMP_APPA) >> 2);
13218 			cp = (u_char *)(th + 1);
13219 			*cp = TCPOPT_NOP;
13220 			cp++;
13221 			*cp = TCPOPT_NOP;
13222 			cp++;
13223 			*cp = TCPOPT_TIMESTAMP;
13224 			cp++;
13225 			*cp = TCPOLEN_TIMESTAMP;
13226 			cp++;
13227 			val = htonl(ae->ts_value);
13228 			bcopy((char *)&val,
13229 			      (char *)cp, sizeof(uint32_t));
13230 			val = htonl(ae->ts_echo);
13231 			bcopy((char *)&val,
13232 			      (char *)(cp + 4), sizeof(uint32_t));
13233 		} else
13234 			th->th_off = (sizeof(struct tcphdr) >> 2);
13235 
13236 		/*
13237 		 * For sane logging we need to play a little trick.
13238 		 * If the ack were fully processed we would have moved
13239 		 * snd_una to high_seq, but since compressed acks are
13240 		 * processed in two phases, at this point (logging) snd_una
13241 		 * won't be advanced. So we would see multiple acks showing
13242 		 * the advancement. We can prevent that by "pretending" that
13243 		 * snd_una was advanced and then un-advancing it so that the
13244 		 * logging code has the right value for tlb_snd_una.
13245 		 */
13246 		if (tp->snd_una != high_seq) {
13247 			orig_snd_una = tp->snd_una;
13248 			tp->snd_una = high_seq;
13249 			xx = 1;
13250 		} else
13251 			xx = 0;
13252 		TCP_LOG_EVENTP(tp, th,
13253 			       &tptosocket(tp)->so_rcv,
13254 			       &tptosocket(tp)->so_snd, TCP_LOG_IN, 0,
13255 			       0, &log, true, &ltv);
13256 		if (xx) {
13257 			tp->snd_una = orig_snd_una;
13258 		}
13259 	}
13260 
13261 }
13262 
13263 static void
13264 rack_handle_probe_response(struct tcp_rack *rack, uint32_t tiwin, uint32_t us_cts)
13265 {
13266 	uint32_t us_rtt;
13267 	/*
13268 	 * A persist or keep-alive was forced out, update our
13269 	 * min rtt time. Note now worry about lost responses.
13270 	 * When a subsequent keep-alive or persist times out
13271 	 * and forced_ack is still on, then the last probe
13272 	 * was not responded to. In such cases we have a
13273 	 * sysctl that controls the behavior. Either we apply
13274 	 * the rtt but with reduced confidence (0). Or we just
13275 	 * plain don't apply the rtt estimate. Having data flow
13276 	 * will clear the probe_not_answered flag i.e. cum-ack
13277 	 * move forward <or> exiting and reentering persists.
13278 	 */
13279 
13280 	rack->forced_ack = 0;
13281 	rack->rc_tp->t_rxtshift = 0;
13282 	if ((rack->rc_in_persist &&
13283 	     (tiwin == rack->rc_tp->snd_wnd)) ||
13284 	    (rack->rc_in_persist == 0)) {
13285 		/*
13286 		 * In persists only apply the RTT update if this is
13287 		 * a response to our window probe. And that
13288 		 * means the rwnd sent must match the current
13289 		 * snd_wnd. If it does not, then we got a
13290 		 * window update ack instead. For keepalive
13291 		 * we allow the answer no matter what the window.
13292 		 *
13293 		 * Note that if the probe_not_answered is set then
13294 		 * the forced_ack_ts is the oldest one i.e. the first
13295 		 * probe sent that might have been lost. This assures
13296 		 * us that if we do calculate an RTT it is longer not
13297 		 * some short thing.
13298 		 */
13299 		if (rack->rc_in_persist)
13300 			counter_u64_add(rack_persists_acks, 1);
13301 		us_rtt = us_cts - rack->r_ctl.forced_ack_ts;
13302 		if (us_rtt == 0)
13303 			us_rtt = 1;
13304 		if (rack->probe_not_answered == 0) {
13305 			rack_apply_updated_usrtt(rack, us_rtt, us_cts);
13306 			tcp_rack_xmit_timer(rack, us_rtt, 0, us_rtt, 3, NULL, 1);
13307 		} else {
13308 			/* We have a retransmitted probe here too */
13309 			if (rack_apply_rtt_with_reduced_conf) {
13310 				rack_apply_updated_usrtt(rack, us_rtt, us_cts);
13311 				tcp_rack_xmit_timer(rack, us_rtt, 0, us_rtt, 0, NULL, 1);
13312 			}
13313 		}
13314 	}
13315 }
13316 
13317 static int
13318 rack_do_compressed_ack_processing(struct tcpcb *tp, struct socket *so, struct mbuf *m, int nxt_pkt, struct timeval *tv)
13319 {
13320 	/*
13321 	 * Handle a "special" compressed ack mbuf. Each incoming
13322 	 * ack has only four possible dispositions:
13323 	 *
13324 	 * A) It moves the cum-ack forward
13325 	 * B) It is behind the cum-ack.
13326 	 * C) It is a window-update ack.
13327 	 * D) It is a dup-ack.
13328 	 *
13329 	 * Note that we can have between 1 -> TCP_COMP_ACK_ENTRIES
13330 	 * in the incoming mbuf. We also need to still pay attention
13331 	 * to nxt_pkt since there may be another packet after this
13332 	 * one.
13333 	 */
13334 #ifdef TCP_ACCOUNTING
13335 	uint64_t ts_val;
13336 	uint64_t rdstc;
13337 #endif
13338 	int segsiz;
13339 	struct timespec ts;
13340 	struct tcp_rack *rack;
13341 	struct tcp_ackent *ae;
13342 	uint32_t tiwin, ms_cts, cts, acked, acked_amount, high_seq, win_seq, the_win, win_upd_ack;
13343 	int cnt, i, did_out, ourfinisacked = 0;
13344 	struct tcpopt to_holder, *to = NULL;
13345 #ifdef TCP_ACCOUNTING
13346 	int win_up_req = 0;
13347 #endif
13348 	int nsegs = 0;
13349 	int under_pacing = 1;
13350 	int recovery = 0;
13351 #ifdef TCP_ACCOUNTING
13352 	sched_pin();
13353 #endif
13354 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13355 	if (rack->gp_ready &&
13356 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT))
13357 		under_pacing = 0;
13358 	else
13359 		under_pacing = 1;
13360 
13361 	if (rack->r_state != tp->t_state)
13362 		rack_set_state(tp, rack);
13363 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
13364 	    (tp->t_flags & TF_GPUTINPROG)) {
13365 		/*
13366 		 * We have a goodput in progress
13367 		 * and we have entered a late state.
13368 		 * Do we have enough data in the sb
13369 		 * to handle the GPUT request?
13370 		 */
13371 		uint32_t bytes;
13372 
13373 		bytes = tp->gput_ack - tp->gput_seq;
13374 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
13375 			bytes += tp->gput_seq - tp->snd_una;
13376 		if (bytes > sbavail(&tptosocket(tp)->so_snd)) {
13377 			/*
13378 			 * There are not enough bytes in the socket
13379 			 * buffer that have been sent to cover this
13380 			 * measurement. Cancel it.
13381 			 */
13382 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
13383 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
13384 						   tp->gput_seq,
13385 						   0, 0, 18, __LINE__, NULL, 0);
13386 			tp->t_flags &= ~TF_GPUTINPROG;
13387 		}
13388 	}
13389 	to = &to_holder;
13390 	to->to_flags = 0;
13391 	KASSERT((m->m_len >= sizeof(struct tcp_ackent)),
13392 		("tp:%p m_cmpack:%p with invalid len:%u", tp, m, m->m_len));
13393 	cnt = m->m_len / sizeof(struct tcp_ackent);
13394 	counter_u64_add(rack_multi_single_eq, cnt);
13395 	high_seq = tp->snd_una;
13396 	the_win = tp->snd_wnd;
13397 	win_seq = tp->snd_wl1;
13398 	win_upd_ack = tp->snd_wl2;
13399 	cts = tcp_tv_to_usectick(tv);
13400 	ms_cts = tcp_tv_to_mssectick(tv);
13401 	rack->r_ctl.rc_rcvtime = cts;
13402 	segsiz = ctf_fixed_maxseg(tp);
13403 	if ((rack->rc_gp_dyn_mul) &&
13404 	    (rack->use_fixed_rate == 0) &&
13405 	    (rack->rc_always_pace)) {
13406 		/* Check in on probertt */
13407 		rack_check_probe_rtt(rack, cts);
13408 	}
13409 	for (i = 0; i < cnt; i++) {
13410 #ifdef TCP_ACCOUNTING
13411 		ts_val = get_cyclecount();
13412 #endif
13413 		rack_clear_rate_sample(rack);
13414 		ae = ((mtod(m, struct tcp_ackent *)) + i);
13415 		/* Setup the window */
13416 		tiwin = ae->win << tp->snd_scale;
13417 		if (tiwin > rack->r_ctl.rc_high_rwnd)
13418 			rack->r_ctl.rc_high_rwnd = tiwin;
13419 		/* figure out the type of ack */
13420 		if (SEQ_LT(ae->ack, high_seq)) {
13421 			/* Case B*/
13422 			ae->ack_val_set = ACK_BEHIND;
13423 		} else if (SEQ_GT(ae->ack, high_seq)) {
13424 			/* Case A */
13425 			ae->ack_val_set = ACK_CUMACK;
13426 		} else if ((tiwin == the_win) && (rack->rc_in_persist == 0)){
13427 			/* Case D */
13428 			ae->ack_val_set = ACK_DUPACK;
13429 		} else {
13430 			/* Case C */
13431 			ae->ack_val_set = ACK_RWND;
13432 		}
13433 		rack_log_input_packet(tp, rack, ae, ae->ack_val_set, high_seq);
13434 		/* Validate timestamp */
13435 		if (ae->flags & HAS_TSTMP) {
13436 			/* Setup for a timestamp */
13437 			to->to_flags = TOF_TS;
13438 			ae->ts_echo -= tp->ts_offset;
13439 			to->to_tsecr = ae->ts_echo;
13440 			to->to_tsval = ae->ts_value;
13441 			/*
13442 			 * If echoed timestamp is later than the current time, fall back to
13443 			 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
13444 			 * were used when this connection was established.
13445 			 */
13446 			if (TSTMP_GT(ae->ts_echo, ms_cts))
13447 				to->to_tsecr = 0;
13448 			if (tp->ts_recent &&
13449 			    TSTMP_LT(ae->ts_value, tp->ts_recent)) {
13450 				if (ctf_ts_check_ac(tp, (ae->flags & 0xff))) {
13451 #ifdef TCP_ACCOUNTING
13452 					rdstc = get_cyclecount();
13453 					if (rdstc > ts_val) {
13454 						counter_u64_add(tcp_proc_time[ae->ack_val_set] ,
13455 								(rdstc - ts_val));
13456 						if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13457 							tp->tcp_proc_time[ae->ack_val_set] += (rdstc - ts_val);
13458 						}
13459 					}
13460 #endif
13461 					continue;
13462 				}
13463 			}
13464 			if (SEQ_LEQ(ae->seq, tp->last_ack_sent) &&
13465 			    SEQ_LEQ(tp->last_ack_sent, ae->seq)) {
13466 				tp->ts_recent_age = tcp_ts_getticks();
13467 				tp->ts_recent = ae->ts_value;
13468 			}
13469 		} else {
13470 			/* Setup for a no options */
13471 			to->to_flags = 0;
13472 		}
13473 		/* Update the rcv time and perform idle reduction possibly */
13474 		if  (tp->t_idle_reduce &&
13475 		     (tp->snd_max == tp->snd_una) &&
13476 		     (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
13477 			counter_u64_add(rack_input_idle_reduces, 1);
13478 			rack_cc_after_idle(rack, tp);
13479 		}
13480 		tp->t_rcvtime = ticks;
13481 		/* Now what about ECN of a chain of pure ACKs? */
13482 		if (tcp_ecn_input_segment(tp, ae->flags, 0,
13483 			tcp_packets_this_ack(tp, ae->ack),
13484 			ae->codepoint))
13485 			rack_cong_signal(tp, CC_ECN, ae->ack, __LINE__);
13486 #ifdef TCP_ACCOUNTING
13487 		/* Count for the specific type of ack in */
13488 		counter_u64_add(tcp_cnt_counters[ae->ack_val_set], 1);
13489 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13490 			tp->tcp_cnt_counters[ae->ack_val_set]++;
13491 		}
13492 #endif
13493 		/*
13494 		 * Note how we could move up these in the determination
13495 		 * above, but we don't so that way the timestamp checks (and ECN)
13496 		 * is done first before we do any processing on the ACK.
13497 		 * The non-compressed path through the code has this
13498 		 * weakness (noted by @jtl) that it actually does some
13499 		 * processing before verifying the timestamp information.
13500 		 * We don't take that path here which is why we set
13501 		 * the ack_val_set first, do the timestamp and ecn
13502 		 * processing, and then look at what we have setup.
13503 		 */
13504 		if (ae->ack_val_set == ACK_BEHIND) {
13505 			/*
13506 			 * Case B flag reordering, if window is not closed
13507 			 * or it could be a keep-alive or persists
13508 			 */
13509 			if (SEQ_LT(ae->ack, tp->snd_una) && (sbspace(&so->so_rcv) > segsiz)) {
13510 				rack->r_ctl.rc_reorder_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
13511 			}
13512 		} else if (ae->ack_val_set == ACK_DUPACK) {
13513 			/* Case D */
13514 			rack_strike_dupack(rack);
13515 		} else if (ae->ack_val_set == ACK_RWND) {
13516 			/* Case C */
13517 			if ((ae->flags & TSTMP_LRO) || (ae->flags & TSTMP_HDWR)) {
13518 				ts.tv_sec = ae->timestamp / 1000000000;
13519 				ts.tv_nsec = ae->timestamp % 1000000000;
13520 				rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
13521 				rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
13522 			} else {
13523 				rack->r_ctl.act_rcv_time = *tv;
13524 			}
13525 			if (rack->forced_ack) {
13526 				rack_handle_probe_response(rack, tiwin,
13527 							   tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time));
13528 			}
13529 #ifdef TCP_ACCOUNTING
13530 			win_up_req = 1;
13531 #endif
13532 			win_upd_ack = ae->ack;
13533 			win_seq = ae->seq;
13534 			the_win = tiwin;
13535 			rack_do_win_updates(tp, rack, the_win, win_seq, win_upd_ack, cts, high_seq);
13536 		} else {
13537 			/* Case A */
13538 			if (SEQ_GT(ae->ack, tp->snd_max)) {
13539 				/*
13540 				 * We just send an ack since the incoming
13541 				 * ack is beyond the largest seq we sent.
13542 				 */
13543 				if ((tp->t_flags & TF_ACKNOW) == 0) {
13544 					ctf_ack_war_checks(tp, &rack->r_ctl.challenge_ack_ts, &rack->r_ctl.challenge_ack_cnt);
13545 					if (tp->t_flags && TF_ACKNOW)
13546 						rack->r_wanted_output = 1;
13547 				}
13548 			} else {
13549 				nsegs++;
13550 				/* If the window changed setup to update */
13551 				if (tiwin != tp->snd_wnd) {
13552 					win_upd_ack = ae->ack;
13553 					win_seq = ae->seq;
13554 					the_win = tiwin;
13555 					rack_do_win_updates(tp, rack, the_win, win_seq, win_upd_ack, cts, high_seq);
13556 				}
13557 #ifdef TCP_ACCOUNTING
13558 				/* Account for the acks */
13559 				if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13560 					tp->tcp_cnt_counters[CNT_OF_ACKS_IN] += (((ae->ack - high_seq) + segsiz - 1) / segsiz);
13561 				}
13562 				counter_u64_add(tcp_cnt_counters[CNT_OF_ACKS_IN],
13563 						(((ae->ack - high_seq) + segsiz - 1) / segsiz));
13564 #endif
13565 				high_seq = ae->ack;
13566 				if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
13567 					union tcp_log_stackspecific log;
13568 					struct timeval tv;
13569 
13570 					memset(&log.u_bbr, 0, sizeof(log.u_bbr));
13571 					log.u_bbr.timeStamp = tcp_get_usecs(&tv);
13572 					log.u_bbr.flex1 = high_seq;
13573 					log.u_bbr.flex2 = rack->r_ctl.roundends;
13574 					log.u_bbr.flex3 = rack->r_ctl.current_round;
13575 					log.u_bbr.rttProp = (uint64_t)CC_ALGO(tp)->newround;
13576 					log.u_bbr.flex8 = 8;
13577 					tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
13578 						       0, &log, false, NULL, NULL, 0, &tv);
13579 				}
13580 				/*
13581 				 * The draft (v3) calls for us to use SEQ_GEQ, but that
13582 				 * causes issues when we are just going app limited. Lets
13583 				 * instead use SEQ_GT <or> where its equal but more data
13584 				 * is outstanding.
13585 				 */
13586 				if ((SEQ_GT(high_seq, rack->r_ctl.roundends)) ||
13587 				    ((high_seq == rack->r_ctl.roundends) &&
13588 				     SEQ_GT(tp->snd_max, tp->snd_una))) {
13589 					rack->r_ctl.current_round++;
13590 					rack->r_ctl.roundends = tp->snd_max;
13591 					if (CC_ALGO(tp)->newround != NULL) {
13592 						CC_ALGO(tp)->newround(&tp->t_ccv, rack->r_ctl.current_round);
13593 					}
13594 				}
13595 				/* Setup our act_rcv_time */
13596 				if ((ae->flags & TSTMP_LRO) || (ae->flags & TSTMP_HDWR)) {
13597 					ts.tv_sec = ae->timestamp / 1000000000;
13598 					ts.tv_nsec = ae->timestamp % 1000000000;
13599 					rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
13600 					rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
13601 				} else {
13602 					rack->r_ctl.act_rcv_time = *tv;
13603 				}
13604 				rack_process_to_cumack(tp, rack, ae->ack, cts, to);
13605 				if (rack->rc_dsack_round_seen) {
13606 					/* Is the dsack round over? */
13607 					if (SEQ_GEQ(ae->ack, rack->r_ctl.dsack_round_end)) {
13608 						/* Yes it is */
13609 						rack->rc_dsack_round_seen = 0;
13610 						rack_log_dsack_event(rack, 3, __LINE__, 0, 0);
13611 					}
13612 				}
13613 			}
13614 		}
13615 		/* And lets be sure to commit the rtt measurements for this ack */
13616 		tcp_rack_xmit_timer_commit(rack, tp);
13617 #ifdef TCP_ACCOUNTING
13618 		rdstc = get_cyclecount();
13619 		if (rdstc > ts_val) {
13620 			counter_u64_add(tcp_proc_time[ae->ack_val_set] , (rdstc - ts_val));
13621 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13622 				tp->tcp_proc_time[ae->ack_val_set] += (rdstc - ts_val);
13623 				if (ae->ack_val_set == ACK_CUMACK)
13624 					tp->tcp_proc_time[CYC_HANDLE_MAP] += (rdstc - ts_val);
13625 			}
13626 		}
13627 #endif
13628 	}
13629 #ifdef TCP_ACCOUNTING
13630 	ts_val = get_cyclecount();
13631 #endif
13632 	/* Tend to any collapsed window */
13633 	if (SEQ_GT(tp->snd_max, high_seq) && (tp->snd_wnd < (tp->snd_max - high_seq))) {
13634 		/* The peer collapsed the window */
13635 		rack_collapsed_window(rack, (tp->snd_max - high_seq), __LINE__);
13636 	} else if (rack->rc_has_collapsed)
13637 		rack_un_collapse_window(rack, __LINE__);
13638 	if ((rack->r_collapse_point_valid) &&
13639 	    (SEQ_GT(high_seq, rack->r_ctl.high_collapse_point)))
13640 		rack->r_collapse_point_valid = 0;
13641 	acked_amount = acked = (high_seq - tp->snd_una);
13642 	if (acked) {
13643 		/*
13644 		 * Clear the probe not answered flag
13645 		 * since cum-ack moved forward.
13646 		 */
13647 		rack->probe_not_answered = 0;
13648 		if (rack->sack_attack_disable == 0)
13649 			rack_do_decay(rack);
13650 		if (acked >= segsiz) {
13651 			/*
13652 			 * You only get credit for
13653 			 * MSS and greater (and you get extra
13654 			 * credit for larger cum-ack moves).
13655 			 */
13656 			int ac;
13657 
13658 			ac = acked / segsiz;
13659 			rack->r_ctl.ack_count += ac;
13660 			counter_u64_add(rack_ack_total, ac);
13661 		}
13662 		if (rack->r_ctl.ack_count > 0xfff00000) {
13663 			/*
13664 			 * reduce the number to keep us under
13665 			 * a uint32_t.
13666 			 */
13667 			rack->r_ctl.ack_count /= 2;
13668 			rack->r_ctl.sack_count /= 2;
13669 		}
13670 		if (tp->t_flags & TF_NEEDSYN) {
13671 			/*
13672 			 * T/TCP: Connection was half-synchronized, and our SYN has
13673 			 * been ACK'd (so connection is now fully synchronized).  Go
13674 			 * to non-starred state, increment snd_una for ACK of SYN,
13675 			 * and check if we can do window scaling.
13676 			 */
13677 			tp->t_flags &= ~TF_NEEDSYN;
13678 			tp->snd_una++;
13679 			acked_amount = acked = (high_seq - tp->snd_una);
13680 		}
13681 		if (acked > sbavail(&so->so_snd))
13682 			acked_amount = sbavail(&so->so_snd);
13683 #ifdef NETFLIX_EXP_DETECTION
13684 		/*
13685 		 * We only care on a cum-ack move if we are in a sack-disabled
13686 		 * state. We have already added in to the ack_count, and we never
13687 		 * would disable on a cum-ack move, so we only care to do the
13688 		 * detection if it may "undo" it, i.e. we were in disabled already.
13689 		 */
13690 		if (rack->sack_attack_disable)
13691 			rack_do_detection(tp, rack, acked_amount, segsiz);
13692 #endif
13693 		if (IN_FASTRECOVERY(tp->t_flags) &&
13694 		    (rack->rack_no_prr == 0))
13695 			rack_update_prr(tp, rack, acked_amount, high_seq);
13696 		if (IN_RECOVERY(tp->t_flags)) {
13697 			if (SEQ_LT(high_seq, tp->snd_recover) &&
13698 			    (SEQ_LT(high_seq, tp->snd_max))) {
13699 				tcp_rack_partialack(tp);
13700 			} else {
13701 				rack_post_recovery(tp, high_seq);
13702 				recovery = 1;
13703 			}
13704 		}
13705 		/* Handle the rack-log-ack part (sendmap) */
13706 		if ((sbused(&so->so_snd) == 0) &&
13707 		    (acked > acked_amount) &&
13708 		    (tp->t_state >= TCPS_FIN_WAIT_1) &&
13709 		    (tp->t_flags & TF_SENTFIN)) {
13710 			/*
13711 			 * We must be sure our fin
13712 			 * was sent and acked (we can be
13713 			 * in FIN_WAIT_1 without having
13714 			 * sent the fin).
13715 			 */
13716 			ourfinisacked = 1;
13717 			/*
13718 			 * Lets make sure snd_una is updated
13719 			 * since most likely acked_amount = 0 (it
13720 			 * should be).
13721 			 */
13722 			tp->snd_una = high_seq;
13723 		}
13724 		/* Did we make a RTO error? */
13725 		if ((tp->t_flags & TF_PREVVALID) &&
13726 		    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
13727 			tp->t_flags &= ~TF_PREVVALID;
13728 			if (tp->t_rxtshift == 1 &&
13729 			    (int)(ticks - tp->t_badrxtwin) < 0)
13730 				rack_cong_signal(tp, CC_RTO_ERR, high_seq, __LINE__);
13731 		}
13732 		/* Handle the data in the socket buffer */
13733 		KMOD_TCPSTAT_ADD(tcps_rcvackpack, 1);
13734 		KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
13735 		if (acked_amount > 0) {
13736 			struct mbuf *mfree;
13737 
13738 			rack_ack_received(tp, rack, high_seq, nsegs, CC_ACK, recovery);
13739 			SOCKBUF_LOCK(&so->so_snd);
13740 			mfree = sbcut_locked(&so->so_snd, acked_amount);
13741 			tp->snd_una = high_seq;
13742 			/* Note we want to hold the sb lock through the sendmap adjust */
13743 			rack_adjust_sendmap(rack, &so->so_snd, tp->snd_una);
13744 			/* Wake up the socket if we have room to write more */
13745 			rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
13746 			sowwakeup_locked(so);
13747 			m_freem(mfree);
13748 		}
13749 		/* update progress */
13750 		tp->t_acktime = ticks;
13751 		rack_log_progress_event(rack, tp, tp->t_acktime,
13752 					PROGRESS_UPDATE, __LINE__);
13753 		/* Clear out shifts and such */
13754 		tp->t_rxtshift = 0;
13755 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
13756 				   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
13757 		rack->rc_tlp_in_progress = 0;
13758 		rack->r_ctl.rc_tlp_cnt_out = 0;
13759 		/* Send recover and snd_nxt must be dragged along */
13760 		if (SEQ_GT(tp->snd_una, tp->snd_recover))
13761 			tp->snd_recover = tp->snd_una;
13762 		if (SEQ_LT(tp->snd_nxt, tp->snd_una))
13763 			tp->snd_nxt = tp->snd_una;
13764 		/*
13765 		 * If the RXT timer is running we want to
13766 		 * stop it, so we can restart a TLP (or new RXT).
13767 		 */
13768 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
13769 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13770 #ifdef NETFLIX_HTTP_LOGGING
13771 		tcp_http_check_for_comp(rack->rc_tp, high_seq);
13772 #endif
13773 		tp->snd_wl2 = high_seq;
13774 		tp->t_dupacks = 0;
13775 		if (under_pacing &&
13776 		    (rack->use_fixed_rate == 0) &&
13777 		    (rack->in_probe_rtt == 0) &&
13778 		    rack->rc_gp_dyn_mul &&
13779 		    rack->rc_always_pace) {
13780 			/* Check if we are dragging bottom */
13781 			rack_check_bottom_drag(tp, rack, so, acked);
13782 		}
13783 		if (tp->snd_una == tp->snd_max) {
13784 			tp->t_flags &= ~TF_PREVVALID;
13785 			rack->r_ctl.retran_during_recovery = 0;
13786 			rack->r_ctl.dsack_byte_cnt = 0;
13787 			rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
13788 			if (rack->r_ctl.rc_went_idle_time == 0)
13789 				rack->r_ctl.rc_went_idle_time = 1;
13790 			rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
13791 			if (sbavail(&tptosocket(tp)->so_snd) == 0)
13792 				tp->t_acktime = 0;
13793 			/* Set so we might enter persists... */
13794 			rack->r_wanted_output = 1;
13795 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13796 			sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
13797 			if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
13798 			    (sbavail(&so->so_snd) == 0) &&
13799 			    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
13800 				/*
13801 				 * The socket was gone and the
13802 				 * peer sent data (not now in the past), time to
13803 				 * reset him.
13804 				 */
13805 				rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13806 				/* tcp_close will kill the inp pre-log the Reset */
13807 				tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
13808 #ifdef TCP_ACCOUNTING
13809 				rdstc = get_cyclecount();
13810 				if (rdstc > ts_val) {
13811 					counter_u64_add(tcp_proc_time[ACK_CUMACK] , (rdstc - ts_val));
13812 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13813 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13814 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13815 					}
13816 				}
13817 #endif
13818 				m_freem(m);
13819 				tp = tcp_close(tp);
13820 				if (tp == NULL) {
13821 #ifdef TCP_ACCOUNTING
13822 					sched_unpin();
13823 #endif
13824 					return (1);
13825 				}
13826 				/*
13827 				 * We would normally do drop-with-reset which would
13828 				 * send back a reset. We can't since we don't have
13829 				 * all the needed bits. Instead lets arrange for
13830 				 * a call to tcp_output(). That way since we
13831 				 * are in the closed state we will generate a reset.
13832 				 *
13833 				 * Note if tcp_accounting is on we don't unpin since
13834 				 * we do that after the goto label.
13835 				 */
13836 				goto send_out_a_rst;
13837 			}
13838 			if ((sbused(&so->so_snd) == 0) &&
13839 			    (tp->t_state >= TCPS_FIN_WAIT_1) &&
13840 			    (tp->t_flags & TF_SENTFIN)) {
13841 				/*
13842 				 * If we can't receive any more data, then closing user can
13843 				 * proceed. Starting the timer is contrary to the
13844 				 * specification, but if we don't get a FIN we'll hang
13845 				 * forever.
13846 				 *
13847 				 */
13848 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13849 					soisdisconnected(so);
13850 					tcp_timer_activate(tp, TT_2MSL,
13851 							   (tcp_fast_finwait2_recycle ?
13852 							    tcp_finwait2_timeout :
13853 							    TP_MAXIDLE(tp)));
13854 				}
13855 				if (ourfinisacked == 0) {
13856 					/*
13857 					 * We don't change to fin-wait-2 if we have our fin acked
13858 					 * which means we are probably in TCPS_CLOSING.
13859 					 */
13860 					tcp_state_change(tp, TCPS_FIN_WAIT_2);
13861 				}
13862 			}
13863 		}
13864 		/* Wake up the socket if we have room to write more */
13865 		if (sbavail(&so->so_snd)) {
13866 			rack->r_wanted_output = 1;
13867 			if (ctf_progress_timeout_check(tp, true)) {
13868 				rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
13869 							tp, tick, PROGRESS_DROP, __LINE__);
13870 				/*
13871 				 * We cheat here and don't send a RST, we should send one
13872 				 * when the pacer drops the connection.
13873 				 */
13874 #ifdef TCP_ACCOUNTING
13875 				rdstc = get_cyclecount();
13876 				if (rdstc > ts_val) {
13877 					counter_u64_add(tcp_proc_time[ACK_CUMACK] , (rdstc - ts_val));
13878 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13879 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13880 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13881 					}
13882 				}
13883 				sched_unpin();
13884 #endif
13885 				(void)tcp_drop(tp, ETIMEDOUT);
13886 				m_freem(m);
13887 				return (1);
13888 			}
13889 		}
13890 		if (ourfinisacked) {
13891 			switch(tp->t_state) {
13892 			case TCPS_CLOSING:
13893 #ifdef TCP_ACCOUNTING
13894 				rdstc = get_cyclecount();
13895 				if (rdstc > ts_val) {
13896 					counter_u64_add(tcp_proc_time[ACK_CUMACK] ,
13897 							(rdstc - ts_val));
13898 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13899 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13900 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13901 					}
13902 				}
13903 				sched_unpin();
13904 #endif
13905 				tcp_twstart(tp);
13906 				m_freem(m);
13907 				return (1);
13908 				break;
13909 			case TCPS_LAST_ACK:
13910 #ifdef TCP_ACCOUNTING
13911 				rdstc = get_cyclecount();
13912 				if (rdstc > ts_val) {
13913 					counter_u64_add(tcp_proc_time[ACK_CUMACK] ,
13914 							(rdstc - ts_val));
13915 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13916 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13917 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13918 					}
13919 				}
13920 				sched_unpin();
13921 #endif
13922 				tp = tcp_close(tp);
13923 				ctf_do_drop(m, tp);
13924 				return (1);
13925 				break;
13926 			case TCPS_FIN_WAIT_1:
13927 #ifdef TCP_ACCOUNTING
13928 				rdstc = get_cyclecount();
13929 				if (rdstc > ts_val) {
13930 					counter_u64_add(tcp_proc_time[ACK_CUMACK] ,
13931 							(rdstc - ts_val));
13932 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13933 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13934 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13935 					}
13936 				}
13937 #endif
13938 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13939 					soisdisconnected(so);
13940 					tcp_timer_activate(tp, TT_2MSL,
13941 							   (tcp_fast_finwait2_recycle ?
13942 							    tcp_finwait2_timeout :
13943 							    TP_MAXIDLE(tp)));
13944 				}
13945 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
13946 				break;
13947 			default:
13948 				break;
13949 			}
13950 		}
13951 		if (rack->r_fast_output) {
13952 			/*
13953 			 * We re doing fast output.. can we expand that?
13954 			 */
13955 			rack_gain_for_fastoutput(rack, tp, so, acked_amount);
13956 		}
13957 #ifdef TCP_ACCOUNTING
13958 		rdstc = get_cyclecount();
13959 		if (rdstc > ts_val) {
13960 			counter_u64_add(tcp_proc_time[ACK_CUMACK] , (rdstc - ts_val));
13961 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13962 				tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13963 				tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13964 			}
13965 		}
13966 
13967 	} else if (win_up_req) {
13968 		rdstc = get_cyclecount();
13969 		if (rdstc > ts_val) {
13970 			counter_u64_add(tcp_proc_time[ACK_RWND] , (rdstc - ts_val));
13971 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13972 				tp->tcp_proc_time[ACK_RWND] += (rdstc - ts_val);
13973 			}
13974 		}
13975 #endif
13976 	}
13977 	/* Now is there a next packet, if so we are done */
13978 	m_freem(m);
13979 	did_out = 0;
13980 	if (nxt_pkt) {
13981 #ifdef TCP_ACCOUNTING
13982 		sched_unpin();
13983 #endif
13984 		rack_log_doseg_done(rack, cts, nxt_pkt, did_out, 5, nsegs);
13985 		return (0);
13986 	}
13987 	rack_handle_might_revert(tp, rack);
13988 	ctf_calc_rwin(so, tp);
13989 	if ((rack->r_wanted_output != 0) || (rack->r_fast_output != 0)) {
13990 	send_out_a_rst:
13991 		if (tcp_output(tp) < 0) {
13992 #ifdef TCP_ACCOUNTING
13993 			sched_unpin();
13994 #endif
13995 			return (1);
13996 		}
13997 		did_out = 1;
13998 	}
13999 	rack_free_trim(rack);
14000 #ifdef TCP_ACCOUNTING
14001 	sched_unpin();
14002 #endif
14003 	rack_timer_audit(tp, rack, &so->so_snd);
14004 	rack_log_doseg_done(rack, cts, nxt_pkt, did_out, 6, nsegs);
14005 	return (0);
14006 }
14007 
14008 
14009 static int
14010 rack_do_segment_nounlock(struct mbuf *m, struct tcphdr *th, struct socket *so,
14011     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos,
14012     int32_t nxt_pkt, struct timeval *tv)
14013 {
14014 	struct inpcb *inp = tptoinpcb(tp);
14015 #ifdef TCP_ACCOUNTING
14016 	uint64_t ts_val;
14017 #endif
14018 	int32_t thflags, retval, did_out = 0;
14019 	int32_t way_out = 0;
14020 	/*
14021 	 * cts - is the current time from tv (caller gets ts) in microseconds.
14022 	 * ms_cts - is the current time from tv in milliseconds.
14023 	 * us_cts - is the time that LRO or hardware actually got the packet in microseconds.
14024 	 */
14025 	uint32_t cts, us_cts, ms_cts;
14026 	uint32_t tiwin, high_seq;
14027 	struct timespec ts;
14028 	struct tcpopt to;
14029 	struct tcp_rack *rack;
14030 	struct rack_sendmap *rsm;
14031 	int32_t prev_state = 0;
14032 #ifdef TCP_ACCOUNTING
14033 	int ack_val_set = 0xf;
14034 #endif
14035 	int nsegs;
14036 
14037 	NET_EPOCH_ASSERT();
14038 	INP_WLOCK_ASSERT(inp);
14039 
14040 	/*
14041 	 * tv passed from common code is from either M_TSTMP_LRO or
14042 	 * tcp_get_usecs() if no LRO m_pkthdr timestamp is present.
14043 	 */
14044 	rack = (struct tcp_rack *)tp->t_fb_ptr;
14045 	if (m->m_flags & M_ACKCMP) {
14046 		/*
14047 		 * All compressed ack's are ack's by definition so
14048 		 * remove any ack required flag and then do the processing.
14049 		 */
14050 		rack->rc_ack_required = 0;
14051 		return (rack_do_compressed_ack_processing(tp, so, m, nxt_pkt, tv));
14052 	}
14053 	if (m->m_flags & M_ACKCMP) {
14054 		panic("Impossible reach m has ackcmp? m:%p tp:%p", m, tp);
14055 	}
14056 	cts = tcp_tv_to_usectick(tv);
14057 	ms_cts =  tcp_tv_to_mssectick(tv);
14058 	nsegs = m->m_pkthdr.lro_nsegs;
14059 	counter_u64_add(rack_proc_non_comp_ack, 1);
14060 	thflags = tcp_get_flags(th);
14061 #ifdef TCP_ACCOUNTING
14062 	sched_pin();
14063 	if (thflags & TH_ACK)
14064 		ts_val = get_cyclecount();
14065 #endif
14066 	if ((m->m_flags & M_TSTMP) ||
14067 	    (m->m_flags & M_TSTMP_LRO)) {
14068 		mbuf_tstmp2timespec(m, &ts);
14069 		rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
14070 		rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
14071 	} else
14072 		rack->r_ctl.act_rcv_time = *tv;
14073 	kern_prefetch(rack, &prev_state);
14074 	prev_state = 0;
14075 	/*
14076 	 * Unscale the window into a 32-bit value. For the SYN_SENT state
14077 	 * the scale is zero.
14078 	 */
14079 	tiwin = th->th_win << tp->snd_scale;
14080 #ifdef TCP_ACCOUNTING
14081 	if (thflags & TH_ACK) {
14082 		/*
14083 		 * We have a tradeoff here. We can either do what we are
14084 		 * doing i.e. pinning to this CPU and then doing the accounting
14085 		 * <or> we could do a critical enter, setup the rdtsc and cpu
14086 		 * as in below, and then validate we are on the same CPU on
14087 		 * exit. I have choosen to not do the critical enter since
14088 		 * that often will gain you a context switch, and instead lock
14089 		 * us (line above this if) to the same CPU with sched_pin(). This
14090 		 * means we may be context switched out for a higher priority
14091 		 * interupt but we won't be moved to another CPU.
14092 		 *
14093 		 * If this occurs (which it won't very often since we most likely
14094 		 * are running this code in interupt context and only a higher
14095 		 * priority will bump us ... clock?) we will falsely add in
14096 		 * to the time the interupt processing time plus the ack processing
14097 		 * time. This is ok since its a rare event.
14098 		 */
14099 		ack_val_set = tcp_do_ack_accounting(tp, th, &to, tiwin,
14100 						    ctf_fixed_maxseg(tp));
14101 	}
14102 #endif
14103 	/*
14104 	 * Parse options on any incoming segment.
14105 	 */
14106 	memset(&to, 0, sizeof(to));
14107 	tcp_dooptions(&to, (u_char *)(th + 1),
14108 	    (th->th_off << 2) - sizeof(struct tcphdr),
14109 	    (thflags & TH_SYN) ? TO_SYN : 0);
14110 	KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN",
14111 	    __func__));
14112 	KASSERT(tp->t_state != TCPS_TIME_WAIT, ("%s: TCPS_TIME_WAIT",
14113 	    __func__));
14114 
14115 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
14116 	    (tp->t_flags & TF_GPUTINPROG)) {
14117 		/*
14118 		 * We have a goodput in progress
14119 		 * and we have entered a late state.
14120 		 * Do we have enough data in the sb
14121 		 * to handle the GPUT request?
14122 		 */
14123 		uint32_t bytes;
14124 
14125 		bytes = tp->gput_ack - tp->gput_seq;
14126 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
14127 			bytes += tp->gput_seq - tp->snd_una;
14128 		if (bytes > sbavail(&tptosocket(tp)->so_snd)) {
14129 			/*
14130 			 * There are not enough bytes in the socket
14131 			 * buffer that have been sent to cover this
14132 			 * measurement. Cancel it.
14133 			 */
14134 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
14135 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
14136 						   tp->gput_seq,
14137 						   0, 0, 18, __LINE__, NULL, 0);
14138 			tp->t_flags &= ~TF_GPUTINPROG;
14139 		}
14140 	}
14141 	high_seq = th->th_ack;
14142 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
14143 		union tcp_log_stackspecific log;
14144 		struct timeval ltv;
14145 #ifdef NETFLIX_HTTP_LOGGING
14146 		struct http_sendfile_track *http_req;
14147 
14148 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
14149 			http_req = tcp_http_find_req_for_seq(tp, (th->th_ack-1));
14150 		} else {
14151 			http_req = tcp_http_find_req_for_seq(tp, th->th_ack);
14152 		}
14153 #endif
14154 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
14155 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
14156 		if (rack->rack_no_prr == 0)
14157 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
14158 		else
14159 			log.u_bbr.flex1 = 0;
14160 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
14161 		log.u_bbr.use_lt_bw <<= 1;
14162 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
14163 		log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
14164 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
14165 		log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
14166 		log.u_bbr.flex3 = m->m_flags;
14167 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
14168 		log.u_bbr.lost = thflags;
14169 		log.u_bbr.pacing_gain = 0x1;
14170 #ifdef TCP_ACCOUNTING
14171 		log.u_bbr.cwnd_gain = ack_val_set;
14172 #endif
14173 		log.u_bbr.flex7 = 2;
14174 		if (m->m_flags & M_TSTMP) {
14175 			/* Record the hardware timestamp if present */
14176 			mbuf_tstmp2timespec(m, &ts);
14177 			ltv.tv_sec = ts.tv_sec;
14178 			ltv.tv_usec = ts.tv_nsec / 1000;
14179 			log.u_bbr.lt_epoch = tcp_tv_to_usectick(&ltv);
14180 		} else if (m->m_flags & M_TSTMP_LRO) {
14181 			/* Record the LRO the arrival timestamp */
14182 			mbuf_tstmp2timespec(m, &ts);
14183 			ltv.tv_sec = ts.tv_sec;
14184 			ltv.tv_usec = ts.tv_nsec / 1000;
14185 			log.u_bbr.flex5 = tcp_tv_to_usectick(&ltv);
14186 		}
14187 		log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
14188 		/* Log the rcv time */
14189 		log.u_bbr.delRate = m->m_pkthdr.rcv_tstmp;
14190 #ifdef NETFLIX_HTTP_LOGGING
14191 		log.u_bbr.applimited = tp->t_http_closed;
14192 		log.u_bbr.applimited <<= 8;
14193 		log.u_bbr.applimited |= tp->t_http_open;
14194 		log.u_bbr.applimited <<= 8;
14195 		log.u_bbr.applimited |= tp->t_http_req;
14196 		if (http_req) {
14197 			/* Copy out any client req info */
14198 			/* seconds */
14199 			log.u_bbr.pkt_epoch = (http_req->localtime / HPTS_USEC_IN_SEC);
14200 			/* useconds */
14201 			log.u_bbr.delivered = (http_req->localtime % HPTS_USEC_IN_SEC);
14202 			log.u_bbr.rttProp = http_req->timestamp;
14203 			log.u_bbr.cur_del_rate = http_req->start;
14204 			if (http_req->flags & TCP_HTTP_TRACK_FLG_OPEN) {
14205 				log.u_bbr.flex8 |= 1;
14206 			} else {
14207 				log.u_bbr.flex8 |= 2;
14208 				log.u_bbr.bw_inuse = http_req->end;
14209 			}
14210 			log.u_bbr.flex6 = http_req->start_seq;
14211 			if (http_req->flags & TCP_HTTP_TRACK_FLG_COMP) {
14212 				log.u_bbr.flex8 |= 4;
14213 				log.u_bbr.epoch = http_req->end_seq;
14214 			}
14215 		}
14216 #endif
14217 		TCP_LOG_EVENTP(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_IN, 0,
14218 		    tlen, &log, true, &ltv);
14219 	}
14220 	/* Remove ack required flag if set, we have one  */
14221 	if (thflags & TH_ACK)
14222 		rack->rc_ack_required = 0;
14223 	if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) {
14224 		way_out = 4;
14225 		retval = 0;
14226 		m_freem(m);
14227 		goto done_with_input;
14228 	}
14229 	/*
14230 	 * If a segment with the ACK-bit set arrives in the SYN-SENT state
14231 	 * check SEQ.ACK first as described on page 66 of RFC 793, section 3.9.
14232 	 */
14233 	if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) &&
14234 	    (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) {
14235 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
14236 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
14237 #ifdef TCP_ACCOUNTING
14238 		sched_unpin();
14239 #endif
14240 		return (1);
14241 	}
14242 	/*
14243 	 * If timestamps were negotiated during SYN/ACK and a
14244 	 * segment without a timestamp is received, silently drop
14245 	 * the segment, unless it is a RST segment or missing timestamps are
14246 	 * tolerated.
14247 	 * See section 3.2 of RFC 7323.
14248 	 */
14249 	if ((tp->t_flags & TF_RCVD_TSTMP) && !(to.to_flags & TOF_TS) &&
14250 	    ((thflags & TH_RST) == 0) && (V_tcp_tolerate_missing_ts == 0)) {
14251 		way_out = 5;
14252 		retval = 0;
14253 		m_freem(m);
14254 		goto done_with_input;
14255 	}
14256 
14257 	/*
14258 	 * Segment received on connection. Reset idle time and keep-alive
14259 	 * timer. XXX: This should be done after segment validation to
14260 	 * ignore broken/spoofed segs.
14261 	 */
14262 	if  (tp->t_idle_reduce &&
14263 	     (tp->snd_max == tp->snd_una) &&
14264 	     (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
14265 		counter_u64_add(rack_input_idle_reduces, 1);
14266 		rack_cc_after_idle(rack, tp);
14267 	}
14268 	tp->t_rcvtime = ticks;
14269 #ifdef STATS
14270 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_FRWIN, tiwin);
14271 #endif
14272 	if (tiwin > rack->r_ctl.rc_high_rwnd)
14273 		rack->r_ctl.rc_high_rwnd = tiwin;
14274 	/*
14275 	 * TCP ECN processing. XXXJTL: If we ever use ECN, we need to move
14276 	 * this to occur after we've validated the segment.
14277 	 */
14278 	if (tcp_ecn_input_segment(tp, thflags, tlen,
14279 	    tcp_packets_this_ack(tp, th->th_ack),
14280 	    iptos))
14281 		rack_cong_signal(tp, CC_ECN, th->th_ack, __LINE__);
14282 
14283 	/*
14284 	 * If echoed timestamp is later than the current time, fall back to
14285 	 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
14286 	 * were used when this connection was established.
14287 	 */
14288 	if ((to.to_flags & TOF_TS) && (to.to_tsecr != 0)) {
14289 		to.to_tsecr -= tp->ts_offset;
14290 		if (TSTMP_GT(to.to_tsecr, ms_cts))
14291 			to.to_tsecr = 0;
14292 	}
14293 
14294 	/*
14295 	 * If its the first time in we need to take care of options and
14296 	 * verify we can do SACK for rack!
14297 	 */
14298 	if (rack->r_state == 0) {
14299 		/* Should be init'd by rack_init() */
14300 		KASSERT(rack->rc_inp != NULL,
14301 		    ("%s: rack->rc_inp unexpectedly NULL", __func__));
14302 		if (rack->rc_inp == NULL) {
14303 			rack->rc_inp = inp;
14304 		}
14305 
14306 		/*
14307 		 * Process options only when we get SYN/ACK back. The SYN
14308 		 * case for incoming connections is handled in tcp_syncache.
14309 		 * According to RFC1323 the window field in a SYN (i.e., a
14310 		 * <SYN> or <SYN,ACK>) segment itself is never scaled. XXX
14311 		 * this is traditional behavior, may need to be cleaned up.
14312 		 */
14313 		if (tp->t_state == TCPS_SYN_SENT && (thflags & TH_SYN)) {
14314 			/* Handle parallel SYN for ECN */
14315 			tcp_ecn_input_parallel_syn(tp, thflags, iptos);
14316 			if ((to.to_flags & TOF_SCALE) &&
14317 			    (tp->t_flags & TF_REQ_SCALE)) {
14318 				tp->t_flags |= TF_RCVD_SCALE;
14319 				tp->snd_scale = to.to_wscale;
14320 			} else
14321 				tp->t_flags &= ~TF_REQ_SCALE;
14322 			/*
14323 			 * Initial send window.  It will be updated with the
14324 			 * next incoming segment to the scaled value.
14325 			 */
14326 			tp->snd_wnd = th->th_win;
14327 			rack_validate_fo_sendwin_up(tp, rack);
14328 			if ((to.to_flags & TOF_TS) &&
14329 			    (tp->t_flags & TF_REQ_TSTMP)) {
14330 				tp->t_flags |= TF_RCVD_TSTMP;
14331 				tp->ts_recent = to.to_tsval;
14332 				tp->ts_recent_age = cts;
14333 			} else
14334 				tp->t_flags &= ~TF_REQ_TSTMP;
14335 			if (to.to_flags & TOF_MSS) {
14336 				tcp_mss(tp, to.to_mss);
14337 			}
14338 			if ((tp->t_flags & TF_SACK_PERMIT) &&
14339 			    (to.to_flags & TOF_SACKPERM) == 0)
14340 				tp->t_flags &= ~TF_SACK_PERMIT;
14341 			if (IS_FASTOPEN(tp->t_flags)) {
14342 				if (to.to_flags & TOF_FASTOPEN) {
14343 					uint16_t mss;
14344 
14345 					if (to.to_flags & TOF_MSS)
14346 						mss = to.to_mss;
14347 					else
14348 						if ((inp->inp_vflag & INP_IPV6) != 0)
14349 							mss = TCP6_MSS;
14350 						else
14351 							mss = TCP_MSS;
14352 					tcp_fastopen_update_cache(tp, mss,
14353 					    to.to_tfo_len, to.to_tfo_cookie);
14354 				} else
14355 					tcp_fastopen_disable_path(tp);
14356 			}
14357 		}
14358 		/*
14359 		 * At this point we are at the initial call. Here we decide
14360 		 * if we are doing RACK or not. We do this by seeing if
14361 		 * TF_SACK_PERMIT is set and the sack-not-required is clear.
14362 		 * The code now does do dup-ack counting so if you don't
14363 		 * switch back you won't get rack & TLP, but you will still
14364 		 * get this stack.
14365 		 */
14366 
14367 		if ((rack_sack_not_required == 0) &&
14368 		    ((tp->t_flags & TF_SACK_PERMIT) == 0)) {
14369 			tcp_switch_back_to_default(tp);
14370 			(*tp->t_fb->tfb_tcp_do_segment) (m, th, so, tp, drop_hdrlen,
14371 			    tlen, iptos);
14372 #ifdef TCP_ACCOUNTING
14373 			sched_unpin();
14374 #endif
14375 			return (1);
14376 		}
14377 		tcp_set_hpts(inp);
14378 		sack_filter_clear(&rack->r_ctl.rack_sf, th->th_ack);
14379 	}
14380 	if (thflags & TH_FIN)
14381 		tcp_log_end_status(tp, TCP_EI_STATUS_CLIENT_FIN);
14382 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
14383 	if ((rack->rc_gp_dyn_mul) &&
14384 	    (rack->use_fixed_rate == 0) &&
14385 	    (rack->rc_always_pace)) {
14386 		/* Check in on probertt */
14387 		rack_check_probe_rtt(rack, us_cts);
14388 	}
14389 	rack_clear_rate_sample(rack);
14390 	if ((rack->forced_ack) &&
14391 	    ((tcp_get_flags(th) & TH_RST) == 0)) {
14392 		rack_handle_probe_response(rack, tiwin, us_cts);
14393 	}
14394 	/*
14395 	 * This is the one exception case where we set the rack state
14396 	 * always. All other times (timers etc) we must have a rack-state
14397 	 * set (so we assure we have done the checks above for SACK).
14398 	 */
14399 	rack->r_ctl.rc_rcvtime = cts;
14400 	if (rack->r_state != tp->t_state)
14401 		rack_set_state(tp, rack);
14402 	if (SEQ_GT(th->th_ack, tp->snd_una) &&
14403 	    (rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree)) != NULL)
14404 		kern_prefetch(rsm, &prev_state);
14405 	prev_state = rack->r_state;
14406 	retval = (*rack->r_substate) (m, th, so,
14407 	    tp, &to, drop_hdrlen,
14408 	    tlen, tiwin, thflags, nxt_pkt, iptos);
14409 	if (retval == 0) {
14410 		/*
14411 		 * If retval is 1 the tcb is unlocked and most likely the tp
14412 		 * is gone.
14413 		 */
14414 		INP_WLOCK_ASSERT(inp);
14415 		if ((rack->rc_gp_dyn_mul) &&
14416 		    (rack->rc_always_pace) &&
14417 		    (rack->use_fixed_rate == 0) &&
14418 		    rack->in_probe_rtt &&
14419 		    (rack->r_ctl.rc_time_probertt_starts == 0)) {
14420 			/*
14421 			 * If we are going for target, lets recheck before
14422 			 * we output.
14423 			 */
14424 			rack_check_probe_rtt(rack, us_cts);
14425 		}
14426 		if (rack->set_pacing_done_a_iw == 0) {
14427 			/* How much has been acked? */
14428 			if ((tp->snd_una - tp->iss) > (ctf_fixed_maxseg(tp) * 10)) {
14429 				/* We have enough to set in the pacing segment size */
14430 				rack->set_pacing_done_a_iw = 1;
14431 				rack_set_pace_segments(tp, rack, __LINE__, NULL);
14432 			}
14433 		}
14434 		tcp_rack_xmit_timer_commit(rack, tp);
14435 #ifdef TCP_ACCOUNTING
14436 		/*
14437 		 * If we set the ack_val_se to what ack processing we are doing
14438 		 * we also want to track how many cycles we burned. Note
14439 		 * the bits after tcp_output we let be "free". This is because
14440 		 * we are also tracking the tcp_output times as well. Note the
14441 		 * use of 0xf here since we only have 11 counter (0 - 0xa) and
14442 		 * 0xf cannot be returned and is what we initialize it too to
14443 		 * indicate we are not doing the tabulations.
14444 		 */
14445 		if (ack_val_set != 0xf) {
14446 			uint64_t crtsc;
14447 
14448 			crtsc = get_cyclecount();
14449 			counter_u64_add(tcp_proc_time[ack_val_set] , (crtsc - ts_val));
14450 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
14451 				tp->tcp_proc_time[ack_val_set] += (crtsc - ts_val);
14452 			}
14453 		}
14454 #endif
14455 		if (nxt_pkt == 0) {
14456 			if ((rack->r_wanted_output != 0) || (rack->r_fast_output != 0)) {
14457 do_output_now:
14458 				if (tcp_output(tp) < 0)
14459 					return (1);
14460 				did_out = 1;
14461 			}
14462 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
14463 			rack_free_trim(rack);
14464 		}
14465 		/* Update any rounds needed */
14466 		if (rack_verbose_logging &&  (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
14467 			union tcp_log_stackspecific log;
14468 			struct timeval tv;
14469 
14470 			memset(&log.u_bbr, 0, sizeof(log.u_bbr));
14471 			log.u_bbr.timeStamp = tcp_get_usecs(&tv);
14472 			log.u_bbr.flex1 = high_seq;
14473 			log.u_bbr.flex2 = rack->r_ctl.roundends;
14474 			log.u_bbr.flex3 = rack->r_ctl.current_round;
14475 			log.u_bbr.rttProp = (uint64_t)CC_ALGO(tp)->newround;
14476 			log.u_bbr.flex8 = 9;
14477 			tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
14478 				       0, &log, false, NULL, NULL, 0, &tv);
14479 		}
14480 		/*
14481 		 * The draft (v3) calls for us to use SEQ_GEQ, but that
14482 		 * causes issues when we are just going app limited. Lets
14483 		 * instead use SEQ_GT <or> where its equal but more data
14484 		 * is outstanding.
14485 		 */
14486 		if ((SEQ_GT(tp->snd_una, rack->r_ctl.roundends)) ||
14487 		    ((tp->snd_una == rack->r_ctl.roundends) && SEQ_GT(tp->snd_max, tp->snd_una))) {
14488 			rack->r_ctl.current_round++;
14489 			rack->r_ctl.roundends = tp->snd_max;
14490 			if (CC_ALGO(tp)->newround != NULL) {
14491 				CC_ALGO(tp)->newround(&tp->t_ccv, rack->r_ctl.current_round);
14492 			}
14493 		}
14494 		if ((nxt_pkt == 0) &&
14495 		    ((rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) == 0) &&
14496 		    (SEQ_GT(tp->snd_max, tp->snd_una) ||
14497 		     (tp->t_flags & TF_DELACK) ||
14498 		     ((V_tcp_always_keepalive || rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
14499 		      (tp->t_state <= TCPS_CLOSING)))) {
14500 			/* We could not send (probably in the hpts but stopped the timer earlier)? */
14501 			if ((tp->snd_max == tp->snd_una) &&
14502 			    ((tp->t_flags & TF_DELACK) == 0) &&
14503 			    (tcp_in_hpts(rack->rc_inp)) &&
14504 			    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
14505 				/* keep alive not needed if we are hptsi output yet */
14506 				;
14507 			} else {
14508 				int late = 0;
14509 				if (tcp_in_hpts(inp)) {
14510 					if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
14511 						us_cts = tcp_get_usecs(NULL);
14512 						if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
14513 							rack->r_early = 1;
14514 							rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
14515 						} else
14516 							late = 1;
14517 						rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
14518 					}
14519 					tcp_hpts_remove(inp);
14520 				}
14521 				if (late && (did_out == 0)) {
14522 					/*
14523 					 * We are late in the sending
14524 					 * and we did not call the output
14525 					 * (this probably should not happen).
14526 					 */
14527 					goto do_output_now;
14528 				}
14529 				rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
14530 			}
14531 			way_out = 1;
14532 		} else if (nxt_pkt == 0) {
14533 			/* Do we have the correct timer running? */
14534 			rack_timer_audit(tp, rack, &so->so_snd);
14535 			way_out = 2;
14536 		}
14537 	done_with_input:
14538 		rack_log_doseg_done(rack, cts, nxt_pkt, did_out, way_out, max(1, nsegs));
14539 		if (did_out)
14540 			rack->r_wanted_output = 0;
14541 #ifdef TCP_ACCOUNTING
14542 	} else {
14543 		/*
14544 		 * Track the time (see above).
14545 		 */
14546 		if (ack_val_set != 0xf) {
14547 			uint64_t crtsc;
14548 
14549 			crtsc = get_cyclecount();
14550 			counter_u64_add(tcp_proc_time[ack_val_set] , (crtsc - ts_val));
14551 			/*
14552 			 * Note we *DO NOT* increment the per-tcb counters since
14553 			 * in the else the TP may be gone!!
14554 			 */
14555 		}
14556 #endif
14557 	}
14558 #ifdef TCP_ACCOUNTING
14559 	sched_unpin();
14560 #endif
14561 	return (retval);
14562 }
14563 
14564 void
14565 rack_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
14566     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos)
14567 {
14568 	struct timeval tv;
14569 
14570 	/* First lets see if we have old packets */
14571 	if (tp->t_in_pkt) {
14572 		if (ctf_do_queued_segments(so, tp, 1)) {
14573 			m_freem(m);
14574 			return;
14575 		}
14576 	}
14577 	if (m->m_flags & M_TSTMP_LRO) {
14578 		mbuf_tstmp2timeval(m, &tv);
14579 	} else {
14580 		/* Should not be should we kassert instead? */
14581 		tcp_get_usecs(&tv);
14582 	}
14583 	if (rack_do_segment_nounlock(m, th, so, tp,
14584 				     drop_hdrlen, tlen, iptos, 0, &tv) == 0) {
14585 		INP_WUNLOCK(tptoinpcb(tp));
14586 	}
14587 }
14588 
14589 struct rack_sendmap *
14590 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack, uint32_t tsused)
14591 {
14592 	struct rack_sendmap *rsm = NULL;
14593 	int32_t idx;
14594 	uint32_t srtt = 0, thresh = 0, ts_low = 0;
14595 
14596 	/* Return the next guy to be re-transmitted */
14597 	if (RB_EMPTY(&rack->r_ctl.rc_mtree)) {
14598 		return (NULL);
14599 	}
14600 	if (tp->t_flags & TF_SENTFIN) {
14601 		/* retran the end FIN? */
14602 		return (NULL);
14603 	}
14604 	/* ok lets look at this one */
14605 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
14606 	if (rack->r_must_retran && rsm && (rsm->r_flags & RACK_MUST_RXT)) {
14607 		return (rsm);
14608 	}
14609 	if (rsm && ((rsm->r_flags & RACK_ACKED) == 0)) {
14610 		goto check_it;
14611 	}
14612 	rsm = rack_find_lowest_rsm(rack);
14613 	if (rsm == NULL) {
14614 		return (NULL);
14615 	}
14616 check_it:
14617 	if (((rack->rc_tp->t_flags & TF_SACK_PERMIT) == 0) &&
14618 	    (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
14619 		/*
14620 		 * No sack so we automatically do the 3 strikes and
14621 		 * retransmit (no rack timer would be started).
14622 		 */
14623 
14624 		return (rsm);
14625 	}
14626 	if (rsm->r_flags & RACK_ACKED) {
14627 		return (NULL);
14628 	}
14629 	if (((rsm->r_flags & RACK_SACK_PASSED) == 0) &&
14630 	    (rsm->r_dupack < DUP_ACK_THRESHOLD)) {
14631 		/* Its not yet ready */
14632 		return (NULL);
14633 	}
14634 	srtt = rack_grab_rtt(tp, rack);
14635 	idx = rsm->r_rtr_cnt - 1;
14636 	ts_low = (uint32_t)rsm->r_tim_lastsent[idx];
14637 	thresh = rack_calc_thresh_rack(rack, srtt, tsused);
14638 	if ((tsused == ts_low) ||
14639 	    (TSTMP_LT(tsused, ts_low))) {
14640 		/* No time since sending */
14641 		return (NULL);
14642 	}
14643 	if ((tsused - ts_low) < thresh) {
14644 		/* It has not been long enough yet */
14645 		return (NULL);
14646 	}
14647 	if ((rsm->r_dupack >= DUP_ACK_THRESHOLD) ||
14648 	    ((rsm->r_flags & RACK_SACK_PASSED) &&
14649 	     (rack->sack_attack_disable == 0))) {
14650 		/*
14651 		 * We have passed the dup-ack threshold <or>
14652 		 * a SACK has indicated this is missing.
14653 		 * Note that if you are a declared attacker
14654 		 * it is only the dup-ack threshold that
14655 		 * will cause retransmits.
14656 		 */
14657 		/* log retransmit reason */
14658 		rack_log_retran_reason(rack, rsm, (tsused - ts_low), thresh, 1);
14659 		rack->r_fast_output = 0;
14660 		return (rsm);
14661 	}
14662 	return (NULL);
14663 }
14664 
14665 static void
14666 rack_log_pacing_delay_calc(struct tcp_rack *rack, uint32_t len, uint32_t slot,
14667 			   uint64_t bw_est, uint64_t bw, uint64_t len_time, int method,
14668 			   int line, struct rack_sendmap *rsm, uint8_t quality)
14669 {
14670 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
14671 		union tcp_log_stackspecific log;
14672 		struct timeval tv;
14673 
14674 		memset(&log, 0, sizeof(log));
14675 		log.u_bbr.flex1 = slot;
14676 		log.u_bbr.flex2 = len;
14677 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_min_segs;
14678 		log.u_bbr.flex4 = rack->r_ctl.rc_pace_max_segs;
14679 		log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ss;
14680 		log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_ca;
14681 		log.u_bbr.use_lt_bw = rack->rc_ack_can_sendout_data;
14682 		log.u_bbr.use_lt_bw <<= 1;
14683 		log.u_bbr.use_lt_bw |= rack->r_late;
14684 		log.u_bbr.use_lt_bw <<= 1;
14685 		log.u_bbr.use_lt_bw |= rack->r_early;
14686 		log.u_bbr.use_lt_bw <<= 1;
14687 		log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
14688 		log.u_bbr.use_lt_bw <<= 1;
14689 		log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
14690 		log.u_bbr.use_lt_bw <<= 1;
14691 		log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
14692 		log.u_bbr.use_lt_bw <<= 1;
14693 		log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
14694 		log.u_bbr.use_lt_bw <<= 1;
14695 		log.u_bbr.use_lt_bw |= rack->gp_ready;
14696 		log.u_bbr.pkt_epoch = line;
14697 		log.u_bbr.epoch = rack->r_ctl.rc_agg_delayed;
14698 		log.u_bbr.lt_epoch = rack->r_ctl.rc_agg_early;
14699 		log.u_bbr.applimited = rack->r_ctl.rack_per_of_gp_rec;
14700 		log.u_bbr.bw_inuse = bw_est;
14701 		log.u_bbr.delRate = bw;
14702 		if (rack->r_ctl.gp_bw == 0)
14703 			log.u_bbr.cur_del_rate = 0;
14704 		else
14705 			log.u_bbr.cur_del_rate = rack_get_bw(rack);
14706 		log.u_bbr.rttProp = len_time;
14707 		log.u_bbr.pkts_out = rack->r_ctl.rc_rack_min_rtt;
14708 		log.u_bbr.lost = rack->r_ctl.rc_probertt_sndmax_atexit;
14709 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
14710 		if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh) {
14711 			/* We are in slow start */
14712 			log.u_bbr.flex7 = 1;
14713 		} else {
14714 			/* we are on congestion avoidance */
14715 			log.u_bbr.flex7 = 0;
14716 		}
14717 		log.u_bbr.flex8 = method;
14718 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
14719 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
14720 		log.u_bbr.cwnd_gain = rack->rc_gp_saw_rec;
14721 		log.u_bbr.cwnd_gain <<= 1;
14722 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
14723 		log.u_bbr.cwnd_gain <<= 1;
14724 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
14725 		log.u_bbr.bbr_substate = quality;
14726 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
14727 		    &rack->rc_inp->inp_socket->so_rcv,
14728 		    &rack->rc_inp->inp_socket->so_snd,
14729 		    BBR_LOG_HPTSI_CALC, 0,
14730 		    0, &log, false, &tv);
14731 	}
14732 }
14733 
14734 static uint32_t
14735 rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss)
14736 {
14737 	uint32_t new_tso, user_max;
14738 
14739 	user_max = rack->rc_user_set_max_segs * mss;
14740 	if (rack->rc_force_max_seg) {
14741 		return (user_max);
14742 	}
14743 	if (rack->use_fixed_rate &&
14744 	    ((rack->r_ctl.crte == NULL) ||
14745 	     (bw != rack->r_ctl.crte->rate))) {
14746 		/* Use the user mss since we are not exactly matched */
14747 		return (user_max);
14748 	}
14749 	new_tso = tcp_get_pacing_burst_size(rack->rc_tp, bw, mss, rack_pace_one_seg, rack->r_ctl.crte, NULL);
14750 	if (new_tso > user_max)
14751 		new_tso = user_max;
14752 	return (new_tso);
14753 }
14754 
14755 static int32_t
14756 pace_to_fill_cwnd(struct tcp_rack *rack, int32_t slot, uint32_t len, uint32_t segsiz, int *capped, uint64_t *rate_wanted, uint8_t non_paced)
14757 {
14758 	uint64_t lentim, fill_bw;
14759 
14760 	/* Lets first see if we are full, if so continue with normal rate */
14761 	rack->r_via_fill_cw = 0;
14762 	if (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.cwnd_to_use)
14763 		return (slot);
14764 	if ((ctf_outstanding(rack->rc_tp) + (segsiz-1)) > rack->rc_tp->snd_wnd)
14765 		return (slot);
14766 	if (rack->r_ctl.rc_last_us_rtt == 0)
14767 		return (slot);
14768 	if (rack->rc_pace_fill_if_rttin_range &&
14769 	    (rack->r_ctl.rc_last_us_rtt >=
14770 	     (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack->rtt_limit_mul))) {
14771 		/* The rtt is huge, N * smallest, lets not fill */
14772 		return (slot);
14773 	}
14774 	/*
14775 	 * first lets calculate the b/w based on the last us-rtt
14776 	 * and the sndwnd.
14777 	 */
14778 	fill_bw = rack->r_ctl.cwnd_to_use;
14779 	/* Take the rwnd if its smaller */
14780 	if (fill_bw > rack->rc_tp->snd_wnd)
14781 		fill_bw = rack->rc_tp->snd_wnd;
14782 	if (rack->r_fill_less_agg) {
14783 		/*
14784 		 * Now take away the inflight (this will reduce our
14785 		 * aggressiveness and yeah, if we get that much out in 1RTT
14786 		 * we will have had acks come back and still be behind).
14787 		 */
14788 		fill_bw -= ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
14789 	}
14790 	/* Now lets make it into a b/w */
14791 	fill_bw *= (uint64_t)HPTS_USEC_IN_SEC;
14792 	fill_bw /= (uint64_t)rack->r_ctl.rc_last_us_rtt;
14793 	/* We are below the min b/w */
14794 	if (non_paced)
14795 		*rate_wanted = fill_bw;
14796 	if ((fill_bw < RACK_MIN_BW) || (fill_bw < *rate_wanted))
14797 		return (slot);
14798 	if (rack->r_ctl.bw_rate_cap && (fill_bw > rack->r_ctl.bw_rate_cap))
14799 		fill_bw = rack->r_ctl.bw_rate_cap;
14800 	rack->r_via_fill_cw = 1;
14801 	if (rack->r_rack_hw_rate_caps &&
14802 	    (rack->r_ctl.crte != NULL)) {
14803 		uint64_t high_rate;
14804 
14805 		high_rate = tcp_hw_highest_rate(rack->r_ctl.crte);
14806 		if (fill_bw > high_rate) {
14807 			/* We are capping bw at the highest rate table entry */
14808 			if (*rate_wanted > high_rate) {
14809 				/* The original rate was also capped */
14810 				rack->r_via_fill_cw = 0;
14811 			}
14812 			rack_log_hdwr_pacing(rack,
14813 					     fill_bw, high_rate, __LINE__,
14814 					     0, 3);
14815 			fill_bw = high_rate;
14816 			if (capped)
14817 				*capped = 1;
14818 		}
14819 	} else if ((rack->r_ctl.crte == NULL) &&
14820 		   (rack->rack_hdrw_pacing == 0) &&
14821 		   (rack->rack_hdw_pace_ena) &&
14822 		   rack->r_rack_hw_rate_caps &&
14823 		   (rack->rack_attempt_hdwr_pace == 0) &&
14824 		   (rack->rc_inp->inp_route.ro_nh != NULL) &&
14825 		   (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
14826 		/*
14827 		 * Ok we may have a first attempt that is greater than our top rate
14828 		 * lets check.
14829 		 */
14830 		uint64_t high_rate;
14831 
14832 		high_rate = tcp_hw_highest_rate_ifp(rack->rc_inp->inp_route.ro_nh->nh_ifp, rack->rc_inp);
14833 		if (high_rate) {
14834 			if (fill_bw > high_rate) {
14835 				fill_bw = high_rate;
14836 				if (capped)
14837 					*capped = 1;
14838 			}
14839 		}
14840 	}
14841 	/*
14842 	 * Ok fill_bw holds our mythical b/w to fill the cwnd
14843 	 * in a rtt, what does that time wise equate too?
14844 	 */
14845 	lentim = (uint64_t)(len) * (uint64_t)HPTS_USEC_IN_SEC;
14846 	lentim /= fill_bw;
14847 	*rate_wanted = fill_bw;
14848 	if (non_paced || (lentim < slot)) {
14849 		rack_log_pacing_delay_calc(rack, len, slot, fill_bw,
14850 					   0, lentim, 12, __LINE__, NULL, 0);
14851 		return ((int32_t)lentim);
14852 	} else
14853 		return (slot);
14854 }
14855 
14856 static int32_t
14857 rack_get_pacing_delay(struct tcp_rack *rack, struct tcpcb *tp, uint32_t len, struct rack_sendmap *rsm, uint32_t segsiz)
14858 {
14859 	uint64_t srtt;
14860 	int32_t slot = 0;
14861 	int can_start_hw_pacing = 1;
14862 	int err;
14863 
14864 	if (rack->rc_always_pace == 0) {
14865 		/*
14866 		 * We use the most optimistic possible cwnd/srtt for
14867 		 * sending calculations. This will make our
14868 		 * calculation anticipate getting more through
14869 		 * quicker then possible. But thats ok we don't want
14870 		 * the peer to have a gap in data sending.
14871 		 */
14872 		uint64_t cwnd, tr_perms = 0;
14873 		int32_t reduce = 0;
14874 
14875 	old_method:
14876 		/*
14877 		 * We keep no precise pacing with the old method
14878 		 * instead we use the pacer to mitigate bursts.
14879 		 */
14880 		if (rack->r_ctl.rc_rack_min_rtt)
14881 			srtt = rack->r_ctl.rc_rack_min_rtt;
14882 		else
14883 			srtt = max(tp->t_srtt, 1);
14884 		if (rack->r_ctl.rc_rack_largest_cwnd)
14885 			cwnd = rack->r_ctl.rc_rack_largest_cwnd;
14886 		else
14887 			cwnd = rack->r_ctl.cwnd_to_use;
14888 		/* Inflate cwnd by 1000 so srtt of usecs is in ms */
14889 		tr_perms = (cwnd * 1000) / srtt;
14890 		if (tr_perms == 0) {
14891 			tr_perms = ctf_fixed_maxseg(tp);
14892 		}
14893 		/*
14894 		 * Calculate how long this will take to drain, if
14895 		 * the calculation comes out to zero, thats ok we
14896 		 * will use send_a_lot to possibly spin around for
14897 		 * more increasing tot_len_this_send to the point
14898 		 * that its going to require a pace, or we hit the
14899 		 * cwnd. Which in that case we are just waiting for
14900 		 * a ACK.
14901 		 */
14902 		slot = len / tr_perms;
14903 		/* Now do we reduce the time so we don't run dry? */
14904 		if (slot && rack_slot_reduction) {
14905 			reduce = (slot / rack_slot_reduction);
14906 			if (reduce < slot) {
14907 				slot -= reduce;
14908 			} else
14909 				slot = 0;
14910 		}
14911 		slot *= HPTS_USEC_IN_MSEC;
14912 		if (rack->rc_pace_to_cwnd) {
14913 			uint64_t rate_wanted = 0;
14914 
14915 			slot = pace_to_fill_cwnd(rack, slot, len, segsiz, NULL, &rate_wanted, 1);
14916 			rack->rc_ack_can_sendout_data = 1;
14917 			rack_log_pacing_delay_calc(rack, len, slot, rate_wanted, 0, 0, 14, __LINE__, NULL, 0);
14918 		} else
14919 			rack_log_pacing_delay_calc(rack, len, slot, tr_perms, reduce, 0, 7, __LINE__, NULL, 0);
14920 	} else {
14921 		uint64_t bw_est, res, lentim, rate_wanted;
14922 		uint32_t orig_val, segs, oh;
14923 		int capped = 0;
14924 		int prev_fill;
14925 
14926 		if ((rack->r_rr_config == 1) && rsm) {
14927 			return (rack->r_ctl.rc_min_to);
14928 		}
14929 		if (rack->use_fixed_rate) {
14930 			rate_wanted = bw_est = rack_get_fixed_pacing_bw(rack);
14931 		} else if ((rack->r_ctl.init_rate == 0) &&
14932 #ifdef NETFLIX_PEAKRATE
14933 			   (rack->rc_tp->t_maxpeakrate == 0) &&
14934 #endif
14935 			   (rack->r_ctl.gp_bw == 0)) {
14936 			/* no way to yet do an estimate */
14937 			bw_est = rate_wanted = 0;
14938 		} else {
14939 			bw_est = rack_get_bw(rack);
14940 			rate_wanted = rack_get_output_bw(rack, bw_est, rsm, &capped);
14941 		}
14942 		if ((bw_est == 0) || (rate_wanted == 0) ||
14943 		    ((rack->gp_ready == 0) && (rack->use_fixed_rate == 0))) {
14944 			/*
14945 			 * No way yet to make a b/w estimate or
14946 			 * our raise is set incorrectly.
14947 			 */
14948 			goto old_method;
14949 		}
14950 		/* We need to account for all the overheads */
14951 		segs = (len + segsiz - 1) / segsiz;
14952 		/*
14953 		 * We need the diff between 1514 bytes (e-mtu with e-hdr)
14954 		 * and how much data we put in each packet. Yes this
14955 		 * means we may be off if we are larger than 1500 bytes
14956 		 * or smaller. But this just makes us more conservative.
14957 		 */
14958 		if (rack_hw_rate_min &&
14959 		    (bw_est < rack_hw_rate_min))
14960 			can_start_hw_pacing = 0;
14961 		if (ETHERNET_SEGMENT_SIZE > segsiz)
14962 			oh = ETHERNET_SEGMENT_SIZE - segsiz;
14963 		else
14964 			oh = 0;
14965 		segs *= oh;
14966 		lentim = (uint64_t)(len + segs) * (uint64_t)HPTS_USEC_IN_SEC;
14967 		res = lentim / rate_wanted;
14968 		slot = (uint32_t)res;
14969 		orig_val = rack->r_ctl.rc_pace_max_segs;
14970 		if (rack->r_ctl.crte == NULL) {
14971 			/*
14972 			 * Only do this if we are not hardware pacing
14973 			 * since if we are doing hw-pacing below we will
14974 			 * set make a call after setting up or changing
14975 			 * the rate.
14976 			 */
14977 			rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
14978 		} else if (rack->rc_inp->inp_snd_tag == NULL) {
14979 			/*
14980 			 * We lost our rate somehow, this can happen
14981 			 * if the interface changed underneath us.
14982 			 */
14983 			tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
14984 			rack->r_ctl.crte = NULL;
14985 			/* Lets re-allow attempting to setup pacing */
14986 			rack->rack_hdrw_pacing = 0;
14987 			rack->rack_attempt_hdwr_pace = 0;
14988 			rack_log_hdwr_pacing(rack,
14989 					     rate_wanted, bw_est, __LINE__,
14990 					     0, 6);
14991 		}
14992 		/* Did we change the TSO size, if so log it */
14993 		if (rack->r_ctl.rc_pace_max_segs != orig_val)
14994 			rack_log_pacing_delay_calc(rack, len, slot, orig_val, 0, 0, 15, __LINE__, NULL, 0);
14995 		prev_fill = rack->r_via_fill_cw;
14996 		if ((rack->rc_pace_to_cwnd) &&
14997 		    (capped == 0) &&
14998 		    (rack->use_fixed_rate == 0) &&
14999 		    (rack->in_probe_rtt == 0) &&
15000 		    (IN_FASTRECOVERY(rack->rc_tp->t_flags) == 0)) {
15001 			/*
15002 			 * We want to pace at our rate *or* faster to
15003 			 * fill the cwnd to the max if its not full.
15004 			 */
15005 			slot = pace_to_fill_cwnd(rack, slot, (len+segs), segsiz, &capped, &rate_wanted, 0);
15006 		}
15007 		if ((rack->rc_inp->inp_route.ro_nh != NULL) &&
15008 		    (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
15009 			if ((rack->rack_hdw_pace_ena) &&
15010 			    (can_start_hw_pacing > 0) &&
15011 			    (rack->rack_hdrw_pacing == 0) &&
15012 			    (rack->rack_attempt_hdwr_pace == 0)) {
15013 				/*
15014 				 * Lets attempt to turn on hardware pacing
15015 				 * if we can.
15016 				 */
15017 				rack->rack_attempt_hdwr_pace = 1;
15018 				rack->r_ctl.crte = tcp_set_pacing_rate(rack->rc_tp,
15019 								       rack->rc_inp->inp_route.ro_nh->nh_ifp,
15020 								       rate_wanted,
15021 								       RS_PACING_GEQ,
15022 								       &err, &rack->r_ctl.crte_prev_rate);
15023 				if (rack->r_ctl.crte) {
15024 					rack->rack_hdrw_pacing = 1;
15025 					rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(tp, rate_wanted, segsiz,
15026 												 0, rack->r_ctl.crte,
15027 												 NULL);
15028 					rack_log_hdwr_pacing(rack,
15029 							     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
15030 							     err, 0);
15031 					rack->r_ctl.last_hw_bw_req = rate_wanted;
15032 				} else {
15033 					counter_u64_add(rack_hw_pace_init_fail, 1);
15034 				}
15035 			} else if (rack->rack_hdrw_pacing &&
15036 				   (rack->r_ctl.last_hw_bw_req != rate_wanted)) {
15037 				/* Do we need to adjust our rate? */
15038 				const struct tcp_hwrate_limit_table *nrte;
15039 
15040 				if (rack->r_up_only &&
15041 				    (rate_wanted < rack->r_ctl.crte->rate)) {
15042 					/**
15043 					 * We have four possible states here
15044 					 * having to do with the previous time
15045 					 * and this time.
15046 					 *   previous  |  this-time
15047 					 * A)     0      |     0   -- fill_cw not in the picture
15048 					 * B)     1      |     0   -- we were doing a fill-cw but now are not
15049 					 * C)     1      |     1   -- all rates from fill_cw
15050 					 * D)     0      |     1   -- we were doing non-fill and now we are filling
15051 					 *
15052 					 * For case A, C and D we don't allow a drop. But for
15053 					 * case B where we now our on our steady rate we do
15054 					 * allow a drop.
15055 					 *
15056 					 */
15057 					if (!((prev_fill == 1) && (rack->r_via_fill_cw == 0)))
15058 						goto done_w_hdwr;
15059 				}
15060 				if ((rate_wanted > rack->r_ctl.crte->rate) ||
15061 				    (rate_wanted <= rack->r_ctl.crte_prev_rate)) {
15062 					if (rack_hw_rate_to_low &&
15063 					    (bw_est < rack_hw_rate_to_low)) {
15064 						/*
15065 						 * The pacing rate is too low for hardware, but
15066 						 * do allow hardware pacing to be restarted.
15067 						 */
15068 						rack_log_hdwr_pacing(rack,
15069 							     bw_est, rack->r_ctl.crte->rate, __LINE__,
15070 							     0, 5);
15071 						tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
15072 						rack->r_ctl.crte = NULL;
15073 						rack->rack_attempt_hdwr_pace = 0;
15074 						rack->rack_hdrw_pacing = 0;
15075 						rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
15076 						goto done_w_hdwr;
15077 					}
15078 					nrte = tcp_chg_pacing_rate(rack->r_ctl.crte,
15079 								   rack->rc_tp,
15080 								   rack->rc_inp->inp_route.ro_nh->nh_ifp,
15081 								   rate_wanted,
15082 								   RS_PACING_GEQ,
15083 								   &err, &rack->r_ctl.crte_prev_rate);
15084 					if (nrte == NULL) {
15085 						/* Lost the rate */
15086 						rack->rack_hdrw_pacing = 0;
15087 						rack->r_ctl.crte = NULL;
15088 						rack_log_hdwr_pacing(rack,
15089 								     rate_wanted, 0, __LINE__,
15090 								     err, 1);
15091 						rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
15092 						counter_u64_add(rack_hw_pace_lost, 1);
15093 					} else if (nrte != rack->r_ctl.crte) {
15094 						rack->r_ctl.crte = nrte;
15095 						rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(tp, rate_wanted,
15096 													 segsiz, 0,
15097 													 rack->r_ctl.crte,
15098 													 NULL);
15099 						rack_log_hdwr_pacing(rack,
15100 								     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
15101 								     err, 2);
15102 						rack->r_ctl.last_hw_bw_req = rate_wanted;
15103 					}
15104 				} else {
15105 					/* We just need to adjust the segment size */
15106 					rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
15107 					rack_log_hdwr_pacing(rack,
15108 							     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
15109 							     0, 4);
15110 					rack->r_ctl.last_hw_bw_req = rate_wanted;
15111 				}
15112 			}
15113 		}
15114 		if ((rack->r_ctl.crte != NULL) &&
15115 		    (rack->r_ctl.crte->rate == rate_wanted)) {
15116 			/*
15117 			 * We need to add a extra if the rates
15118 			 * are exactly matched. The idea is
15119 			 * we want the software to make sure the
15120 			 * queue is empty before adding more, this
15121 			 * gives us N MSS extra pace times where
15122 			 * N is our sysctl
15123 			 */
15124 			slot += (rack->r_ctl.crte->time_between * rack_hw_pace_extra_slots);
15125 		}
15126 done_w_hdwr:
15127 		if (rack_limit_time_with_srtt &&
15128 		    (rack->use_fixed_rate == 0) &&
15129 #ifdef NETFLIX_PEAKRATE
15130 		    (rack->rc_tp->t_maxpeakrate == 0) &&
15131 #endif
15132 		    (rack->rack_hdrw_pacing == 0)) {
15133 			/*
15134 			 * Sanity check, we do not allow the pacing delay
15135 			 * to be longer than the SRTT of the path. If it is
15136 			 * a slow path, then adding a packet should increase
15137 			 * the RTT and compensate for this i.e. the srtt will
15138 			 * be greater so the allowed pacing time will be greater.
15139 			 *
15140 			 * Note this restriction is not for where a peak rate
15141 			 * is set, we are doing fixed pacing or hardware pacing.
15142 			 */
15143 			if (rack->rc_tp->t_srtt)
15144 				srtt = rack->rc_tp->t_srtt;
15145 			else
15146 				srtt = RACK_INITIAL_RTO * HPTS_USEC_IN_MSEC;	/* its in ms convert */
15147 			if (srtt < (uint64_t)slot) {
15148 				rack_log_pacing_delay_calc(rack, srtt, slot, rate_wanted, bw_est, lentim, 99, __LINE__, NULL, 0);
15149 				slot = srtt;
15150 			}
15151 		}
15152 		rack_log_pacing_delay_calc(rack, len, slot, rate_wanted, bw_est, lentim, 2, __LINE__, rsm, 0);
15153 	}
15154 	if (rack->r_ctl.crte && (rack->r_ctl.crte->rs_num_enobufs > 0)) {
15155 		/*
15156 		 * If this rate is seeing enobufs when it
15157 		 * goes to send then either the nic is out
15158 		 * of gas or we are mis-estimating the time
15159 		 * somehow and not letting the queue empty
15160 		 * completely. Lets add to the pacing time.
15161 		 */
15162 		int hw_boost_delay;
15163 
15164 		hw_boost_delay = rack->r_ctl.crte->time_between * rack_enobuf_hw_boost_mult;
15165 		if (hw_boost_delay > rack_enobuf_hw_max)
15166 			hw_boost_delay = rack_enobuf_hw_max;
15167 		else if (hw_boost_delay < rack_enobuf_hw_min)
15168 			hw_boost_delay = rack_enobuf_hw_min;
15169 		slot += hw_boost_delay;
15170 	}
15171 	return (slot);
15172 }
15173 
15174 static void
15175 rack_start_gp_measurement(struct tcpcb *tp, struct tcp_rack *rack,
15176     tcp_seq startseq, uint32_t sb_offset)
15177 {
15178 	struct rack_sendmap *my_rsm = NULL;
15179 	struct rack_sendmap fe;
15180 
15181 	if (tp->t_state < TCPS_ESTABLISHED) {
15182 		/*
15183 		 * We don't start any measurements if we are
15184 		 * not at least established.
15185 		 */
15186 		return;
15187 	}
15188 	if (tp->t_state >= TCPS_FIN_WAIT_1) {
15189 		/*
15190 		 * We will get no more data into the SB
15191 		 * this means we need to have the data available
15192 		 * before we start a measurement.
15193 		 */
15194 
15195 		if (sbavail(&tptosocket(tp)->so_snd) <
15196 		    max(rc_init_window(rack),
15197 			(MIN_GP_WIN * ctf_fixed_maxseg(tp)))) {
15198 			/* Nope not enough data */
15199 			return;
15200 		}
15201 	}
15202 	tp->t_flags |= TF_GPUTINPROG;
15203 	rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
15204 	rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
15205 	tp->gput_seq = startseq;
15206 	rack->app_limited_needs_set = 0;
15207 	if (rack->in_probe_rtt)
15208 		rack->measure_saw_probe_rtt = 1;
15209 	else if ((rack->measure_saw_probe_rtt) &&
15210 		 (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
15211 		rack->measure_saw_probe_rtt = 0;
15212 	if (rack->rc_gp_filled)
15213 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
15214 	else {
15215 		/* Special case initial measurement */
15216 		struct timeval tv;
15217 
15218 		tp->gput_ts = tcp_get_usecs(&tv);
15219 		rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
15220 	}
15221 	/*
15222 	 * We take a guess out into the future,
15223 	 * if we have no measurement and no
15224 	 * initial rate, we measure the first
15225 	 * initial-windows worth of data to
15226 	 * speed up getting some GP measurement and
15227 	 * thus start pacing.
15228 	 */
15229 	if ((rack->rc_gp_filled == 0) && (rack->r_ctl.init_rate == 0)) {
15230 		rack->app_limited_needs_set = 1;
15231 		tp->gput_ack = startseq + max(rc_init_window(rack),
15232 					      (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
15233 		rack_log_pacing_delay_calc(rack,
15234 					   tp->gput_seq,
15235 					   tp->gput_ack,
15236 					   0,
15237 					   tp->gput_ts,
15238 					   rack->r_ctl.rc_app_limited_cnt,
15239 					   9,
15240 					   __LINE__, NULL, 0);
15241 		return;
15242 	}
15243 	if (sb_offset) {
15244 		/*
15245 		 * We are out somewhere in the sb
15246 		 * can we use the already outstanding data?
15247 		 */
15248 		if (rack->r_ctl.rc_app_limited_cnt == 0) {
15249 			/*
15250 			 * Yes first one is good and in this case
15251 			 * the tp->gput_ts is correctly set based on
15252 			 * the last ack that arrived (no need to
15253 			 * set things up when an ack comes in).
15254 			 */
15255 			my_rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
15256 			if ((my_rsm == NULL) ||
15257 			    (my_rsm->r_rtr_cnt != 1)) {
15258 				/* retransmission? */
15259 				goto use_latest;
15260 			}
15261 		} else {
15262 			if (rack->r_ctl.rc_first_appl == NULL) {
15263 				/*
15264 				 * If rc_first_appl is NULL
15265 				 * then the cnt should be 0.
15266 				 * This is probably an error, maybe
15267 				 * a KASSERT would be approprate.
15268 				 */
15269 				goto use_latest;
15270 			}
15271 			/*
15272 			 * If we have a marker pointer to the last one that is
15273 			 * app limited we can use that, but we need to set
15274 			 * things up so that when it gets ack'ed we record
15275 			 * the ack time (if its not already acked).
15276 			 */
15277 			rack->app_limited_needs_set = 1;
15278 			/*
15279 			 * We want to get to the rsm that is either
15280 			 * next with space i.e. over 1 MSS or the one
15281 			 * after that (after the app-limited).
15282 			 */
15283 			my_rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree,
15284 					 rack->r_ctl.rc_first_appl);
15285 			if (my_rsm) {
15286 				if ((my_rsm->r_end - my_rsm->r_start) <= ctf_fixed_maxseg(tp))
15287 					/* Have to use the next one */
15288 					my_rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree,
15289 							 my_rsm);
15290 				else {
15291 					/* Use after the first MSS of it is acked */
15292 					tp->gput_seq = my_rsm->r_start + ctf_fixed_maxseg(tp);
15293 					goto start_set;
15294 				}
15295 			}
15296 			if ((my_rsm == NULL) ||
15297 			    (my_rsm->r_rtr_cnt != 1)) {
15298 				/*
15299 				 * Either its a retransmit or
15300 				 * the last is the app-limited one.
15301 				 */
15302 				goto use_latest;
15303 			}
15304 		}
15305 		tp->gput_seq = my_rsm->r_start;
15306 start_set:
15307 		if (my_rsm->r_flags & RACK_ACKED) {
15308 			/*
15309 			 * This one has been acked use the arrival ack time
15310 			 */
15311 			tp->gput_ts = (uint32_t)my_rsm->r_ack_arrival;
15312 			rack->app_limited_needs_set = 0;
15313 		}
15314 		rack->r_ctl.rc_gp_output_ts = my_rsm->r_tim_lastsent[(my_rsm->r_rtr_cnt-1)];
15315 		tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
15316 		rack_log_pacing_delay_calc(rack,
15317 					   tp->gput_seq,
15318 					   tp->gput_ack,
15319 					   (uint64_t)my_rsm,
15320 					   tp->gput_ts,
15321 					   rack->r_ctl.rc_app_limited_cnt,
15322 					   9,
15323 					   __LINE__, NULL, 0);
15324 		return;
15325 	}
15326 
15327 use_latest:
15328 	/*
15329 	 * We don't know how long we may have been
15330 	 * idle or if this is the first-send. Lets
15331 	 * setup the flag so we will trim off
15332 	 * the first ack'd data so we get a true
15333 	 * measurement.
15334 	 */
15335 	rack->app_limited_needs_set = 1;
15336 	tp->gput_ack = startseq + rack_get_measure_window(tp, rack);
15337 	/* Find this guy so we can pull the send time */
15338 	fe.r_start = startseq;
15339 	my_rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
15340 	if (my_rsm) {
15341 		rack->r_ctl.rc_gp_output_ts = my_rsm->r_tim_lastsent[(my_rsm->r_rtr_cnt-1)];
15342 		if (my_rsm->r_flags & RACK_ACKED) {
15343 			/*
15344 			 * Unlikely since its probably what was
15345 			 * just transmitted (but I am paranoid).
15346 			 */
15347 			tp->gput_ts = (uint32_t)my_rsm->r_ack_arrival;
15348 			rack->app_limited_needs_set = 0;
15349 		}
15350 		if (SEQ_LT(my_rsm->r_start, tp->gput_seq)) {
15351 			/* This also is unlikely */
15352 			tp->gput_seq = my_rsm->r_start;
15353 		}
15354 	} else {
15355 		/*
15356 		 * TSNH unless we have some send-map limit,
15357 		 * and even at that it should not be hitting
15358 		 * that limit (we should have stopped sending).
15359 		 */
15360 		struct timeval tv;
15361 
15362 		microuptime(&tv);
15363 		rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
15364 	}
15365 	rack_log_pacing_delay_calc(rack,
15366 				   tp->gput_seq,
15367 				   tp->gput_ack,
15368 				   (uint64_t)my_rsm,
15369 				   tp->gput_ts,
15370 				   rack->r_ctl.rc_app_limited_cnt,
15371 				   9, __LINE__, NULL, 0);
15372 }
15373 
15374 static inline uint32_t
15375 rack_what_can_we_send(struct tcpcb *tp, struct tcp_rack *rack,  uint32_t cwnd_to_use,
15376     uint32_t avail, int32_t sb_offset)
15377 {
15378 	uint32_t len;
15379 	uint32_t sendwin;
15380 
15381 	if (tp->snd_wnd > cwnd_to_use)
15382 		sendwin = cwnd_to_use;
15383 	else
15384 		sendwin = tp->snd_wnd;
15385 	if (ctf_outstanding(tp) >= tp->snd_wnd) {
15386 		/* We never want to go over our peers rcv-window */
15387 		len = 0;
15388 	} else {
15389 		uint32_t flight;
15390 
15391 		flight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
15392 		if (flight >= sendwin) {
15393 			/*
15394 			 * We have in flight what we are allowed by cwnd (if
15395 			 * it was rwnd blocking it would have hit above out
15396 			 * >= tp->snd_wnd).
15397 			 */
15398 			return (0);
15399 		}
15400 		len = sendwin - flight;
15401 		if ((len + ctf_outstanding(tp)) > tp->snd_wnd) {
15402 			/* We would send too much (beyond the rwnd) */
15403 			len = tp->snd_wnd - ctf_outstanding(tp);
15404 		}
15405 		if ((len + sb_offset) > avail) {
15406 			/*
15407 			 * We don't have that much in the SB, how much is
15408 			 * there?
15409 			 */
15410 			len = avail - sb_offset;
15411 		}
15412 	}
15413 	return (len);
15414 }
15415 
15416 static void
15417 rack_log_fsb(struct tcp_rack *rack, struct tcpcb *tp, struct socket *so, uint32_t flags,
15418 	     unsigned ipoptlen, int32_t orig_len, int32_t len, int error,
15419 	     int rsm_is_null, int optlen, int line, uint16_t mode)
15420 {
15421 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
15422 		union tcp_log_stackspecific log;
15423 		struct timeval tv;
15424 
15425 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
15426 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
15427 		log.u_bbr.flex1 = error;
15428 		log.u_bbr.flex2 = flags;
15429 		log.u_bbr.flex3 = rsm_is_null;
15430 		log.u_bbr.flex4 = ipoptlen;
15431 		log.u_bbr.flex5 = tp->rcv_numsacks;
15432 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
15433 		log.u_bbr.flex7 = optlen;
15434 		log.u_bbr.flex8 = rack->r_fsb_inited;
15435 		log.u_bbr.applimited = rack->r_fast_output;
15436 		log.u_bbr.bw_inuse = rack_get_bw(rack);
15437 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
15438 		log.u_bbr.cwnd_gain = mode;
15439 		log.u_bbr.pkts_out = orig_len;
15440 		log.u_bbr.lt_epoch = len;
15441 		log.u_bbr.delivered = line;
15442 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
15443 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
15444 		tcp_log_event_(tp, NULL, &so->so_rcv, &so->so_snd, TCP_LOG_FSB, 0,
15445 			       len, &log, false, NULL, NULL, 0, &tv);
15446 	}
15447 }
15448 
15449 
15450 static struct mbuf *
15451 rack_fo_base_copym(struct mbuf *the_m, uint32_t the_off, int32_t *plen,
15452 		   struct rack_fast_send_blk *fsb,
15453 		   int32_t seglimit, int32_t segsize, int hw_tls)
15454 {
15455 #ifdef KERN_TLS
15456 	struct ktls_session *tls, *ntls;
15457 #ifdef INVARIANTS
15458 	struct mbuf *start;
15459 #endif
15460 #endif
15461 	struct mbuf *m, *n, **np, *smb;
15462 	struct mbuf *top;
15463 	int32_t off, soff;
15464 	int32_t len = *plen;
15465 	int32_t fragsize;
15466 	int32_t len_cp = 0;
15467 	uint32_t mlen, frags;
15468 
15469 	soff = off = the_off;
15470 	smb = m = the_m;
15471 	np = &top;
15472 	top = NULL;
15473 #ifdef KERN_TLS
15474 	if (hw_tls && (m->m_flags & M_EXTPG))
15475 		tls = m->m_epg_tls;
15476 	else
15477 		tls = NULL;
15478 #ifdef INVARIANTS
15479 	start = m;
15480 #endif
15481 #endif
15482 	while (len > 0) {
15483 		if (m == NULL) {
15484 			*plen = len_cp;
15485 			break;
15486 		}
15487 #ifdef KERN_TLS
15488 		if (hw_tls) {
15489 			if (m->m_flags & M_EXTPG)
15490 				ntls = m->m_epg_tls;
15491 			else
15492 				ntls = NULL;
15493 
15494 			/*
15495 			 * Avoid mixing TLS records with handshake
15496 			 * data or TLS records from different
15497 			 * sessions.
15498 			 */
15499 			if (tls != ntls) {
15500 				MPASS(m != start);
15501 				*plen = len_cp;
15502 				break;
15503 			}
15504 		}
15505 #endif
15506 		mlen = min(len, m->m_len - off);
15507 		if (seglimit) {
15508 			/*
15509 			 * For M_EXTPG mbufs, add 3 segments
15510 			 * + 1 in case we are crossing page boundaries
15511 			 * + 2 in case the TLS hdr/trailer are used
15512 			 * It is cheaper to just add the segments
15513 			 * than it is to take the cache miss to look
15514 			 * at the mbuf ext_pgs state in detail.
15515 			 */
15516 			if (m->m_flags & M_EXTPG) {
15517 				fragsize = min(segsize, PAGE_SIZE);
15518 				frags = 3;
15519 			} else {
15520 				fragsize = segsize;
15521 				frags = 0;
15522 			}
15523 
15524 			/* Break if we really can't fit anymore. */
15525 			if ((frags + 1) >= seglimit) {
15526 				*plen =	len_cp;
15527 				break;
15528 			}
15529 
15530 			/*
15531 			 * Reduce size if you can't copy the whole
15532 			 * mbuf. If we can't copy the whole mbuf, also
15533 			 * adjust len so the loop will end after this
15534 			 * mbuf.
15535 			 */
15536 			if ((frags + howmany(mlen, fragsize)) >= seglimit) {
15537 				mlen = (seglimit - frags - 1) * fragsize;
15538 				len = mlen;
15539 				*plen = len_cp + len;
15540 			}
15541 			frags += howmany(mlen, fragsize);
15542 			if (frags == 0)
15543 				frags++;
15544 			seglimit -= frags;
15545 			KASSERT(seglimit > 0,
15546 			    ("%s: seglimit went too low", __func__));
15547 		}
15548 		n = m_get(M_NOWAIT, m->m_type);
15549 		*np = n;
15550 		if (n == NULL)
15551 			goto nospace;
15552 		n->m_len = mlen;
15553 		soff += mlen;
15554 		len_cp += n->m_len;
15555 		if (m->m_flags & (M_EXT|M_EXTPG)) {
15556 			n->m_data = m->m_data + off;
15557 			mb_dupcl(n, m);
15558 		} else {
15559 			bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t),
15560 			    (u_int)n->m_len);
15561 		}
15562 		len -= n->m_len;
15563 		off = 0;
15564 		m = m->m_next;
15565 		np = &n->m_next;
15566 		if (len || (soff == smb->m_len)) {
15567 			/*
15568 			 * We have more so we move forward  or
15569 			 * we have consumed the entire mbuf and
15570 			 * len has fell to 0.
15571 			 */
15572 			soff = 0;
15573 			smb = m;
15574 		}
15575 
15576 	}
15577 	if (fsb != NULL) {
15578 		fsb->m = smb;
15579 		fsb->off = soff;
15580 		if (smb) {
15581 			/*
15582 			 * Save off the size of the mbuf. We do
15583 			 * this so that we can recognize when it
15584 			 * has been trimmed by sbcut() as acks
15585 			 * come in.
15586 			 */
15587 			fsb->o_m_len = smb->m_len;
15588 		} else {
15589 			/*
15590 			 * This is the case where the next mbuf went to NULL. This
15591 			 * means with this copy we have sent everything in the sb.
15592 			 * In theory we could clear the fast_output flag, but lets
15593 			 * not since its possible that we could get more added
15594 			 * and acks that call the extend function which would let
15595 			 * us send more.
15596 			 */
15597 			fsb->o_m_len = 0;
15598 		}
15599 	}
15600 	return (top);
15601 nospace:
15602 	if (top)
15603 		m_freem(top);
15604 	return (NULL);
15605 
15606 }
15607 
15608 /*
15609  * This is a copy of m_copym(), taking the TSO segment size/limit
15610  * constraints into account, and advancing the sndptr as it goes.
15611  */
15612 static struct mbuf *
15613 rack_fo_m_copym(struct tcp_rack *rack, int32_t *plen,
15614 		int32_t seglimit, int32_t segsize, struct mbuf **s_mb, int *s_soff)
15615 {
15616 	struct mbuf *m, *n;
15617 	int32_t soff;
15618 
15619 	soff = rack->r_ctl.fsb.off;
15620 	m = rack->r_ctl.fsb.m;
15621 	if (rack->r_ctl.fsb.o_m_len > m->m_len) {
15622 		/*
15623 		 * The mbuf had the front of it chopped off by an ack
15624 		 * we need to adjust the soff/off by that difference.
15625 		 */
15626 		uint32_t delta;
15627 
15628 		delta = rack->r_ctl.fsb.o_m_len - m->m_len;
15629 		soff -= delta;
15630 	} else if (rack->r_ctl.fsb.o_m_len < m->m_len) {
15631 		/*
15632 		 * The mbuf was expanded probably by
15633 		 * a m_compress. Just update o_m_len.
15634 		 */
15635 		rack->r_ctl.fsb.o_m_len = m->m_len;
15636 	}
15637 	KASSERT(soff >= 0, ("%s, negative off %d", __FUNCTION__, soff));
15638 	KASSERT(*plen >= 0, ("%s, negative len %d", __FUNCTION__, *plen));
15639 	KASSERT(soff < m->m_len, ("%s rack:%p len:%u m:%p m->m_len:%u < off?",
15640 				 __FUNCTION__,
15641 				 rack, *plen, m, m->m_len));
15642 	/* Save off the right location before we copy and advance */
15643 	*s_soff = soff;
15644 	*s_mb = rack->r_ctl.fsb.m;
15645 	n = rack_fo_base_copym(m, soff, plen,
15646 			       &rack->r_ctl.fsb,
15647 			       seglimit, segsize, rack->r_ctl.fsb.hw_tls);
15648 	return (n);
15649 }
15650 
15651 static int
15652 rack_fast_rsm_output(struct tcpcb *tp, struct tcp_rack *rack, struct rack_sendmap *rsm,
15653 		     uint64_t ts_val, uint32_t cts, uint32_t ms_cts, struct timeval *tv, int len, uint8_t doing_tlp)
15654 {
15655 	/*
15656 	 * Enter the fast retransmit path. We are given that a sched_pin is
15657 	 * in place (if accounting is compliled in) and the cycle count taken
15658 	 * at the entry is in the ts_val. The concept her is that the rsm
15659 	 * now holds the mbuf offsets and such so we can directly transmit
15660 	 * without a lot of overhead, the len field is already set for
15661 	 * us to prohibit us from sending too much (usually its 1MSS).
15662 	 */
15663 	struct ip *ip = NULL;
15664 	struct udphdr *udp = NULL;
15665 	struct tcphdr *th = NULL;
15666 	struct mbuf *m = NULL;
15667 	struct inpcb *inp;
15668 	uint8_t *cpto;
15669 	struct tcp_log_buffer *lgb;
15670 #ifdef TCP_ACCOUNTING
15671 	uint64_t crtsc;
15672 	int cnt_thru = 1;
15673 #endif
15674 	struct tcpopt to;
15675 	u_char opt[TCP_MAXOLEN];
15676 	uint32_t hdrlen, optlen;
15677 	int32_t slot, segsiz, max_val, tso = 0, error, ulen = 0;
15678 	uint16_t flags;
15679 	uint32_t if_hw_tsomaxsegcount = 0, startseq;
15680 	uint32_t if_hw_tsomaxsegsize;
15681 
15682 #ifdef INET6
15683 	struct ip6_hdr *ip6 = NULL;
15684 
15685 	if (rack->r_is_v6) {
15686 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
15687 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
15688 	} else
15689 #endif				/* INET6 */
15690 	{
15691 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
15692 		hdrlen = sizeof(struct tcpiphdr);
15693 	}
15694 	if (tp->t_port && (V_tcp_udp_tunneling_port == 0)) {
15695 		goto failed;
15696 	}
15697 	if (doing_tlp) {
15698 		/* Its a TLP add the flag, it may already be there but be sure */
15699 		rsm->r_flags |= RACK_TLP;
15700 	} else {
15701 		/* If it was a TLP it is not not on this retransmit */
15702 		rsm->r_flags &= ~RACK_TLP;
15703 	}
15704 	startseq = rsm->r_start;
15705 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
15706 	inp = rack->rc_inp;
15707 	to.to_flags = 0;
15708 	flags = tcp_outflags[tp->t_state];
15709 	if (flags & (TH_SYN|TH_RST)) {
15710 		goto failed;
15711 	}
15712 	if (rsm->r_flags & RACK_HAS_FIN) {
15713 		/* We can't send a FIN here */
15714 		goto failed;
15715 	}
15716 	if (flags & TH_FIN) {
15717 		/* We never send a FIN */
15718 		flags &= ~TH_FIN;
15719 	}
15720 	if (tp->t_flags & TF_RCVD_TSTMP) {
15721 		to.to_tsval = ms_cts + tp->ts_offset;
15722 		to.to_tsecr = tp->ts_recent;
15723 		to.to_flags = TOF_TS;
15724 	}
15725 	optlen = tcp_addoptions(&to, opt);
15726 	hdrlen += optlen;
15727 	udp = rack->r_ctl.fsb.udp;
15728 	if (udp)
15729 		hdrlen += sizeof(struct udphdr);
15730 	if (rack->r_ctl.rc_pace_max_segs)
15731 		max_val = rack->r_ctl.rc_pace_max_segs;
15732 	else if (rack->rc_user_set_max_segs)
15733 		max_val = rack->rc_user_set_max_segs * segsiz;
15734 	else
15735 		max_val = len;
15736 	if ((tp->t_flags & TF_TSO) &&
15737 	    V_tcp_do_tso &&
15738 	    (len > segsiz) &&
15739 	    (tp->t_port == 0))
15740 		tso = 1;
15741 #ifdef INET6
15742 	if (MHLEN < hdrlen + max_linkhdr)
15743 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
15744 	else
15745 #endif
15746 		m = m_gethdr(M_NOWAIT, MT_DATA);
15747 	if (m == NULL)
15748 		goto failed;
15749 	m->m_data += max_linkhdr;
15750 	m->m_len = hdrlen;
15751 	th = rack->r_ctl.fsb.th;
15752 	/* Establish the len to send */
15753 	if (len > max_val)
15754 		len = max_val;
15755 	if ((tso) && (len + optlen > tp->t_maxseg)) {
15756 		uint32_t if_hw_tsomax;
15757 		int32_t max_len;
15758 
15759 		/* extract TSO information */
15760 		if_hw_tsomax = tp->t_tsomax;
15761 		if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
15762 		if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
15763 		/*
15764 		 * Check if we should limit by maximum payload
15765 		 * length:
15766 		 */
15767 		if (if_hw_tsomax != 0) {
15768 			/* compute maximum TSO length */
15769 			max_len = (if_hw_tsomax - hdrlen -
15770 				   max_linkhdr);
15771 			if (max_len <= 0) {
15772 				goto failed;
15773 			} else if (len > max_len) {
15774 				len = max_len;
15775 			}
15776 		}
15777 		if (len <= segsiz) {
15778 			/*
15779 			 * In case there are too many small fragments don't
15780 			 * use TSO:
15781 			 */
15782 			tso = 0;
15783 		}
15784 	} else {
15785 		tso = 0;
15786 	}
15787 	if ((tso == 0) && (len > segsiz))
15788 		len = segsiz;
15789 	if ((len == 0) ||
15790 	    (len <= MHLEN - hdrlen - max_linkhdr)) {
15791 		goto failed;
15792 	}
15793 	th->th_seq = htonl(rsm->r_start);
15794 	th->th_ack = htonl(tp->rcv_nxt);
15795 	/*
15796 	 * The PUSH bit should only be applied
15797 	 * if the full retransmission is made. If
15798 	 * we are sending less than this is the
15799 	 * left hand edge and should not have
15800 	 * the PUSH bit.
15801 	 */
15802 	if ((rsm->r_flags & RACK_HAD_PUSH) &&
15803 	    (len == (rsm->r_end - rsm->r_start)))
15804 		flags |= TH_PUSH;
15805 	th->th_win = htons((u_short)(rack->r_ctl.fsb.recwin >> tp->rcv_scale));
15806 	if (th->th_win == 0) {
15807 		tp->t_sndzerowin++;
15808 		tp->t_flags |= TF_RXWIN0SENT;
15809 	} else
15810 		tp->t_flags &= ~TF_RXWIN0SENT;
15811 	if (rsm->r_flags & RACK_TLP) {
15812 		/*
15813 		 * TLP should not count in retran count, but
15814 		 * in its own bin
15815 		 */
15816 		counter_u64_add(rack_tlp_retran, 1);
15817 		counter_u64_add(rack_tlp_retran_bytes, len);
15818 	} else {
15819 		tp->t_sndrexmitpack++;
15820 		KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
15821 		KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
15822 	}
15823 #ifdef STATS
15824 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
15825 				 len);
15826 #endif
15827 	if (rsm->m == NULL)
15828 		goto failed;
15829 	if (rsm->orig_m_len != rsm->m->m_len) {
15830 		/* Fix up the orig_m_len and possibly the mbuf offset */
15831 		rack_adjust_orig_mlen(rsm);
15832 	}
15833 	m->m_next = rack_fo_base_copym(rsm->m, rsm->soff, &len, NULL, if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, rsm->r_hw_tls);
15834 	if (len <= segsiz) {
15835 		/*
15836 		 * Must have ran out of mbufs for the copy
15837 		 * shorten it to no longer need tso. Lets
15838 		 * not put on sendalot since we are low on
15839 		 * mbufs.
15840 		 */
15841 		tso = 0;
15842 	}
15843 	if ((m->m_next == NULL) || (len <= 0)){
15844 		goto failed;
15845 	}
15846 	if (udp) {
15847 		if (rack->r_is_v6)
15848 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
15849 		else
15850 			ulen = hdrlen + len - sizeof(struct ip);
15851 		udp->uh_ulen = htons(ulen);
15852 	}
15853 	m->m_pkthdr.rcvif = (struct ifnet *)0;
15854 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
15855 	    (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))) {
15856 		int ect = tcp_ecn_output_established(tp, &flags, len, true);
15857 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
15858 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
15859 		    tp->t_flags2 &= ~TF2_ECN_SND_ECE;
15860 #ifdef INET6
15861 		if (rack->r_is_v6) {
15862 		    ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
15863 		    ip6->ip6_flow |= htonl(ect << 20);
15864 		}
15865 		else
15866 #endif
15867 		{
15868 		    ip->ip_tos &= ~IPTOS_ECN_MASK;
15869 		    ip->ip_tos |= ect;
15870 		}
15871 	}
15872 	tcp_set_flags(th, flags);
15873 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
15874 #ifdef INET6
15875 	if (rack->r_is_v6) {
15876 		if (tp->t_port) {
15877 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
15878 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
15879 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
15880 			th->th_sum = htons(0);
15881 			UDPSTAT_INC(udps_opackets);
15882 		} else {
15883 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
15884 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
15885 			th->th_sum = in6_cksum_pseudo(ip6,
15886 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
15887 						      0);
15888 		}
15889 	}
15890 #endif
15891 #if defined(INET6) && defined(INET)
15892 	else
15893 #endif
15894 #ifdef INET
15895 	{
15896 		if (tp->t_port) {
15897 			m->m_pkthdr.csum_flags = CSUM_UDP;
15898 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
15899 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
15900 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
15901 			th->th_sum = htons(0);
15902 			UDPSTAT_INC(udps_opackets);
15903 		} else {
15904 			m->m_pkthdr.csum_flags = CSUM_TCP;
15905 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
15906 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
15907 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
15908 									IPPROTO_TCP + len + optlen));
15909 		}
15910 		/* IP version must be set here for ipv4/ipv6 checking later */
15911 		KASSERT(ip->ip_v == IPVERSION,
15912 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
15913 	}
15914 #endif
15915 	if (tso) {
15916 		KASSERT(len > tp->t_maxseg - optlen,
15917 			("%s: len <= tso_segsz tp:%p", __func__, tp));
15918 		m->m_pkthdr.csum_flags |= CSUM_TSO;
15919 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
15920 	}
15921 #ifdef INET6
15922 	if (rack->r_is_v6) {
15923 		ip6->ip6_hlim = rack->r_ctl.fsb.hoplimit;
15924 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
15925 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
15926 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
15927 		else
15928 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
15929 	}
15930 #endif
15931 #if defined(INET) && defined(INET6)
15932 	else
15933 #endif
15934 #ifdef INET
15935 	{
15936 		ip->ip_len = htons(m->m_pkthdr.len);
15937 		ip->ip_ttl = rack->r_ctl.fsb.hoplimit;
15938 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
15939 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
15940 			if (tp->t_port == 0 || len < V_tcp_minmss) {
15941 				ip->ip_off |= htons(IP_DF);
15942 			}
15943 		} else {
15944 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
15945 		}
15946 	}
15947 #endif
15948 	/* Time to copy in our header */
15949 	cpto = mtod(m, uint8_t *);
15950 	memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
15951 	th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
15952 	if (optlen) {
15953 		bcopy(opt, th + 1, optlen);
15954 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
15955 	} else {
15956 		th->th_off = sizeof(struct tcphdr) >> 2;
15957 	}
15958 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
15959 		union tcp_log_stackspecific log;
15960 
15961 		if (rsm->r_flags & RACK_RWND_COLLAPSED) {
15962 			rack_log_collapse(rack, rsm->r_start, rsm->r_end, 0, __LINE__, 5, rsm->r_flags, rsm);
15963 			counter_u64_add(rack_collapsed_win_rxt, 1);
15964 			counter_u64_add(rack_collapsed_win_rxt_bytes, (rsm->r_end - rsm->r_start));
15965 		}
15966 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
15967 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
15968 		if (rack->rack_no_prr)
15969 			log.u_bbr.flex1 = 0;
15970 		else
15971 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
15972 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
15973 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
15974 		log.u_bbr.flex4 = max_val;
15975 		log.u_bbr.flex5 = 0;
15976 		/* Save off the early/late values */
15977 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
15978 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
15979 		log.u_bbr.bw_inuse = rack_get_bw(rack);
15980 		if (doing_tlp == 0)
15981 			log.u_bbr.flex8 = 1;
15982 		else
15983 			log.u_bbr.flex8 = 2;
15984 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
15985 		log.u_bbr.flex7 = 55;
15986 		log.u_bbr.pkts_out = tp->t_maxseg;
15987 		log.u_bbr.timeStamp = cts;
15988 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
15989 		log.u_bbr.lt_epoch = rack->r_ctl.cwnd_to_use;
15990 		log.u_bbr.delivered = 0;
15991 		lgb = tcp_log_event_(tp, th, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
15992 				     len, &log, false, NULL, NULL, 0, tv);
15993 	} else
15994 		lgb = NULL;
15995 #ifdef INET6
15996 	if (rack->r_is_v6) {
15997 		error = ip6_output(m, NULL,
15998 				   &inp->inp_route6,
15999 				   0, NULL, NULL, inp);
16000 	}
16001 #endif
16002 #if defined(INET) && defined(INET6)
16003 	else
16004 #endif
16005 #ifdef INET
16006 	{
16007 		error = ip_output(m, NULL,
16008 				  &inp->inp_route,
16009 				  0, 0, inp);
16010 	}
16011 #endif
16012 	m = NULL;
16013 	if (lgb) {
16014 		lgb->tlb_errno = error;
16015 		lgb = NULL;
16016 	}
16017 	if (error) {
16018 		goto failed;
16019 	}
16020 	rack_log_output(tp, &to, len, rsm->r_start, flags, error, rack_to_usec_ts(tv),
16021 			rsm, RACK_SENT_FP, rsm->m, rsm->soff, rsm->r_hw_tls);
16022 	if (doing_tlp && (rack->fast_rsm_hack == 0)) {
16023 		rack->rc_tlp_in_progress = 1;
16024 		rack->r_ctl.rc_tlp_cnt_out++;
16025 	}
16026 	if (error == 0) {
16027 		tcp_account_for_send(tp, len, 1, doing_tlp, rsm->r_hw_tls);
16028 		if (doing_tlp) {
16029 			rack->rc_last_sent_tlp_past_cumack = 0;
16030 			rack->rc_last_sent_tlp_seq_valid = 1;
16031 			rack->r_ctl.last_sent_tlp_seq = rsm->r_start;
16032 			rack->r_ctl.last_sent_tlp_len = rsm->r_end - rsm->r_start;
16033 		}
16034 	}
16035 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
16036 	rack->forced_ack = 0;	/* If we send something zap the FA flag */
16037 	if (IN_FASTRECOVERY(tp->t_flags) && rsm)
16038 		rack->r_ctl.retran_during_recovery += len;
16039 	{
16040 		int idx;
16041 
16042 		idx = (len / segsiz) + 3;
16043 		if (idx >= TCP_MSS_ACCT_ATIMER)
16044 			counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
16045 		else
16046 			counter_u64_add(rack_out_size[idx], 1);
16047 	}
16048 	if (tp->t_rtttime == 0) {
16049 		tp->t_rtttime = ticks;
16050 		tp->t_rtseq = startseq;
16051 		KMOD_TCPSTAT_INC(tcps_segstimed);
16052 	}
16053 	counter_u64_add(rack_fto_rsm_send, 1);
16054 	if (error && (error == ENOBUFS)) {
16055 		if (rack->r_ctl.crte != NULL) {
16056 			rack_trace_point(rack, RACK_TP_HWENOBUF);
16057 		} else
16058 			rack_trace_point(rack, RACK_TP_ENOBUF);
16059 		slot = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
16060 		if (rack->rc_enobuf < 0x7f)
16061 			rack->rc_enobuf++;
16062 		if (slot < (10 * HPTS_USEC_IN_MSEC))
16063 			slot = 10 * HPTS_USEC_IN_MSEC;
16064 	} else
16065 		slot = rack_get_pacing_delay(rack, tp, len, NULL, segsiz);
16066 	if ((slot == 0) ||
16067 	    (rack->rc_always_pace == 0) ||
16068 	    (rack->r_rr_config == 1)) {
16069 		/*
16070 		 * We have no pacing set or we
16071 		 * are using old-style rack or
16072 		 * we are overridden to use the old 1ms pacing.
16073 		 */
16074 		slot = rack->r_ctl.rc_min_to;
16075 	}
16076 	rack_start_hpts_timer(rack, tp, cts, slot, len, 0);
16077 #ifdef TCP_ACCOUNTING
16078 	crtsc = get_cyclecount();
16079 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16080 		tp->tcp_cnt_counters[SND_OUT_DATA] += cnt_thru;
16081 	}
16082 	counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], cnt_thru);
16083 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16084 		tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
16085 	}
16086 	counter_u64_add(tcp_proc_time[SND_OUT_DATA], (crtsc - ts_val));
16087 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16088 		tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((len + segsiz - 1) / segsiz);
16089 	}
16090 	counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((len + segsiz - 1) / segsiz));
16091 	sched_unpin();
16092 #endif
16093 	return (0);
16094 failed:
16095 	if (m)
16096 		m_free(m);
16097 	return (-1);
16098 }
16099 
16100 static void
16101 rack_sndbuf_autoscale(struct tcp_rack *rack)
16102 {
16103 	/*
16104 	 * Automatic sizing of send socket buffer.  Often the send buffer
16105 	 * size is not optimally adjusted to the actual network conditions
16106 	 * at hand (delay bandwidth product).  Setting the buffer size too
16107 	 * small limits throughput on links with high bandwidth and high
16108 	 * delay (eg. trans-continental/oceanic links).  Setting the
16109 	 * buffer size too big consumes too much real kernel memory,
16110 	 * especially with many connections on busy servers.
16111 	 *
16112 	 * The criteria to step up the send buffer one notch are:
16113 	 *  1. receive window of remote host is larger than send buffer
16114 	 *     (with a fudge factor of 5/4th);
16115 	 *  2. send buffer is filled to 7/8th with data (so we actually
16116 	 *     have data to make use of it);
16117 	 *  3. send buffer fill has not hit maximal automatic size;
16118 	 *  4. our send window (slow start and cogestion controlled) is
16119 	 *     larger than sent but unacknowledged data in send buffer.
16120 	 *
16121 	 * Note that the rack version moves things much faster since
16122 	 * we want to avoid hitting cache lines in the rack_fast_output()
16123 	 * path so this is called much less often and thus moves
16124 	 * the SB forward by a percentage.
16125 	 */
16126 	struct socket *so;
16127 	struct tcpcb *tp;
16128 	uint32_t sendwin, scaleup;
16129 
16130 	tp = rack->rc_tp;
16131 	so = rack->rc_inp->inp_socket;
16132 	sendwin = min(rack->r_ctl.cwnd_to_use, tp->snd_wnd);
16133 	if (V_tcp_do_autosndbuf && so->so_snd.sb_flags & SB_AUTOSIZE) {
16134 		if ((tp->snd_wnd / 4 * 5) >= so->so_snd.sb_hiwat &&
16135 		    sbused(&so->so_snd) >=
16136 		    (so->so_snd.sb_hiwat / 8 * 7) &&
16137 		    sbused(&so->so_snd) < V_tcp_autosndbuf_max &&
16138 		    sendwin >= (sbused(&so->so_snd) -
16139 		    (tp->snd_nxt - tp->snd_una))) {
16140 			if (rack_autosndbuf_inc)
16141 				scaleup = (rack_autosndbuf_inc * so->so_snd.sb_hiwat) / 100;
16142 			else
16143 				scaleup = V_tcp_autosndbuf_inc;
16144 			if (scaleup < V_tcp_autosndbuf_inc)
16145 				scaleup = V_tcp_autosndbuf_inc;
16146 			scaleup += so->so_snd.sb_hiwat;
16147 			if (scaleup > V_tcp_autosndbuf_max)
16148 				scaleup = V_tcp_autosndbuf_max;
16149 			if (!sbreserve_locked(so, SO_SND, scaleup, curthread))
16150 				so->so_snd.sb_flags &= ~SB_AUTOSIZE;
16151 		}
16152 	}
16153 }
16154 
16155 static int
16156 rack_fast_output(struct tcpcb *tp, struct tcp_rack *rack, uint64_t ts_val,
16157 		 uint32_t cts, uint32_t ms_cts, struct timeval *tv, long tot_len, int *send_err)
16158 {
16159 	/*
16160 	 * Enter to do fast output. We are given that the sched_pin is
16161 	 * in place (if accounting is compiled in) and the cycle count taken
16162 	 * at entry is in place in ts_val. The idea here is that
16163 	 * we know how many more bytes needs to be sent (presumably either
16164 	 * during pacing or to fill the cwnd and that was greater than
16165 	 * the max-burst). We have how much to send and all the info we
16166 	 * need to just send.
16167 	 */
16168 	struct ip *ip = NULL;
16169 	struct udphdr *udp = NULL;
16170 	struct tcphdr *th = NULL;
16171 	struct mbuf *m, *s_mb;
16172 	struct inpcb *inp;
16173 	uint8_t *cpto;
16174 	struct tcp_log_buffer *lgb;
16175 #ifdef TCP_ACCOUNTING
16176 	uint64_t crtsc;
16177 #endif
16178 	struct tcpopt to;
16179 	u_char opt[TCP_MAXOLEN];
16180 	uint32_t hdrlen, optlen;
16181 #ifdef TCP_ACCOUNTING
16182 	int cnt_thru = 1;
16183 #endif
16184 	int32_t slot, segsiz, len, max_val, tso = 0, sb_offset, error, ulen = 0;
16185 	uint16_t flags;
16186 	uint32_t s_soff;
16187 	uint32_t if_hw_tsomaxsegcount = 0, startseq;
16188 	uint32_t if_hw_tsomaxsegsize;
16189 	uint16_t add_flag = RACK_SENT_FP;
16190 #ifdef INET6
16191 	struct ip6_hdr *ip6 = NULL;
16192 
16193 	if (rack->r_is_v6) {
16194 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
16195 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
16196 	} else
16197 #endif				/* INET6 */
16198 	{
16199 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
16200 		hdrlen = sizeof(struct tcpiphdr);
16201 	}
16202 	if (tp->t_port && (V_tcp_udp_tunneling_port == 0)) {
16203 		m = NULL;
16204 		goto failed;
16205 	}
16206 	startseq = tp->snd_max;
16207 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
16208 	inp = rack->rc_inp;
16209 	len = rack->r_ctl.fsb.left_to_send;
16210 	to.to_flags = 0;
16211 	flags = rack->r_ctl.fsb.tcp_flags;
16212 	if (tp->t_flags & TF_RCVD_TSTMP) {
16213 		to.to_tsval = ms_cts + tp->ts_offset;
16214 		to.to_tsecr = tp->ts_recent;
16215 		to.to_flags = TOF_TS;
16216 	}
16217 	optlen = tcp_addoptions(&to, opt);
16218 	hdrlen += optlen;
16219 	udp = rack->r_ctl.fsb.udp;
16220 	if (udp)
16221 		hdrlen += sizeof(struct udphdr);
16222 	if (rack->r_ctl.rc_pace_max_segs)
16223 		max_val = rack->r_ctl.rc_pace_max_segs;
16224 	else if (rack->rc_user_set_max_segs)
16225 		max_val = rack->rc_user_set_max_segs * segsiz;
16226 	else
16227 		max_val = len;
16228 	if ((tp->t_flags & TF_TSO) &&
16229 	    V_tcp_do_tso &&
16230 	    (len > segsiz) &&
16231 	    (tp->t_port == 0))
16232 		tso = 1;
16233 again:
16234 #ifdef INET6
16235 	if (MHLEN < hdrlen + max_linkhdr)
16236 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
16237 	else
16238 #endif
16239 		m = m_gethdr(M_NOWAIT, MT_DATA);
16240 	if (m == NULL)
16241 		goto failed;
16242 	m->m_data += max_linkhdr;
16243 	m->m_len = hdrlen;
16244 	th = rack->r_ctl.fsb.th;
16245 	/* Establish the len to send */
16246 	if (len > max_val)
16247 		len = max_val;
16248 	if ((tso) && (len + optlen > tp->t_maxseg)) {
16249 		uint32_t if_hw_tsomax;
16250 		int32_t max_len;
16251 
16252 		/* extract TSO information */
16253 		if_hw_tsomax = tp->t_tsomax;
16254 		if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
16255 		if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
16256 		/*
16257 		 * Check if we should limit by maximum payload
16258 		 * length:
16259 		 */
16260 		if (if_hw_tsomax != 0) {
16261 			/* compute maximum TSO length */
16262 			max_len = (if_hw_tsomax - hdrlen -
16263 				   max_linkhdr);
16264 			if (max_len <= 0) {
16265 				goto failed;
16266 			} else if (len > max_len) {
16267 				len = max_len;
16268 			}
16269 		}
16270 		if (len <= segsiz) {
16271 			/*
16272 			 * In case there are too many small fragments don't
16273 			 * use TSO:
16274 			 */
16275 			tso = 0;
16276 		}
16277 	} else {
16278 		tso = 0;
16279 	}
16280 	if ((tso == 0) && (len > segsiz))
16281 		len = segsiz;
16282 	if ((len == 0) ||
16283 	    (len <= MHLEN - hdrlen - max_linkhdr)) {
16284 		goto failed;
16285 	}
16286 	sb_offset = tp->snd_max - tp->snd_una;
16287 	th->th_seq = htonl(tp->snd_max);
16288 	th->th_ack = htonl(tp->rcv_nxt);
16289 	th->th_win = htons((u_short)(rack->r_ctl.fsb.recwin >> tp->rcv_scale));
16290 	if (th->th_win == 0) {
16291 		tp->t_sndzerowin++;
16292 		tp->t_flags |= TF_RXWIN0SENT;
16293 	} else
16294 		tp->t_flags &= ~TF_RXWIN0SENT;
16295 	tp->snd_up = tp->snd_una;	/* drag it along, its deprecated */
16296 	KMOD_TCPSTAT_INC(tcps_sndpack);
16297 	KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
16298 #ifdef STATS
16299 	stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
16300 				 len);
16301 #endif
16302 	if (rack->r_ctl.fsb.m == NULL)
16303 		goto failed;
16304 
16305 	/* s_mb and s_soff are saved for rack_log_output */
16306 	m->m_next = rack_fo_m_copym(rack, &len, if_hw_tsomaxsegcount, if_hw_tsomaxsegsize,
16307 				    &s_mb, &s_soff);
16308 	if (len <= segsiz) {
16309 		/*
16310 		 * Must have ran out of mbufs for the copy
16311 		 * shorten it to no longer need tso. Lets
16312 		 * not put on sendalot since we are low on
16313 		 * mbufs.
16314 		 */
16315 		tso = 0;
16316 	}
16317 	if (rack->r_ctl.fsb.rfo_apply_push &&
16318 	    (len == rack->r_ctl.fsb.left_to_send)) {
16319 		flags |= TH_PUSH;
16320 		add_flag |= RACK_HAD_PUSH;
16321 	}
16322 	if ((m->m_next == NULL) || (len <= 0)){
16323 		goto failed;
16324 	}
16325 	if (udp) {
16326 		if (rack->r_is_v6)
16327 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
16328 		else
16329 			ulen = hdrlen + len - sizeof(struct ip);
16330 		udp->uh_ulen = htons(ulen);
16331 	}
16332 	m->m_pkthdr.rcvif = (struct ifnet *)0;
16333 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
16334 	    (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))) {
16335 		int ect = tcp_ecn_output_established(tp, &flags, len, false);
16336 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
16337 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
16338 			tp->t_flags2 &= ~TF2_ECN_SND_ECE;
16339 #ifdef INET6
16340 		if (rack->r_is_v6) {
16341 			ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
16342 			ip6->ip6_flow |= htonl(ect << 20);
16343 		}
16344 		else
16345 #endif
16346 		{
16347 			ip->ip_tos &= ~IPTOS_ECN_MASK;
16348 			ip->ip_tos |= ect;
16349 		}
16350 	}
16351 	tcp_set_flags(th, flags);
16352 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
16353 #ifdef INET6
16354 	if (rack->r_is_v6) {
16355 		if (tp->t_port) {
16356 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
16357 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
16358 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
16359 			th->th_sum = htons(0);
16360 			UDPSTAT_INC(udps_opackets);
16361 		} else {
16362 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
16363 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
16364 			th->th_sum = in6_cksum_pseudo(ip6,
16365 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
16366 						      0);
16367 		}
16368 	}
16369 #endif
16370 #if defined(INET6) && defined(INET)
16371 	else
16372 #endif
16373 #ifdef INET
16374 	{
16375 		if (tp->t_port) {
16376 			m->m_pkthdr.csum_flags = CSUM_UDP;
16377 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
16378 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
16379 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
16380 			th->th_sum = htons(0);
16381 			UDPSTAT_INC(udps_opackets);
16382 		} else {
16383 			m->m_pkthdr.csum_flags = CSUM_TCP;
16384 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
16385 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
16386 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
16387 									IPPROTO_TCP + len + optlen));
16388 		}
16389 		/* IP version must be set here for ipv4/ipv6 checking later */
16390 		KASSERT(ip->ip_v == IPVERSION,
16391 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
16392 	}
16393 #endif
16394 	if (tso) {
16395 		KASSERT(len > tp->t_maxseg - optlen,
16396 			("%s: len <= tso_segsz tp:%p", __func__, tp));
16397 		m->m_pkthdr.csum_flags |= CSUM_TSO;
16398 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
16399 	}
16400 #ifdef INET6
16401 	if (rack->r_is_v6) {
16402 		ip6->ip6_hlim = rack->r_ctl.fsb.hoplimit;
16403 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
16404 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
16405 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
16406 		else
16407 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
16408 	}
16409 #endif
16410 #if defined(INET) && defined(INET6)
16411 	else
16412 #endif
16413 #ifdef INET
16414 	{
16415 		ip->ip_len = htons(m->m_pkthdr.len);
16416 		ip->ip_ttl = rack->r_ctl.fsb.hoplimit;
16417 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
16418 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
16419 			if (tp->t_port == 0 || len < V_tcp_minmss) {
16420 				ip->ip_off |= htons(IP_DF);
16421 			}
16422 		} else {
16423 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
16424 		}
16425 	}
16426 #endif
16427 	/* Time to copy in our header */
16428 	cpto = mtod(m, uint8_t *);
16429 	memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
16430 	th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
16431 	if (optlen) {
16432 		bcopy(opt, th + 1, optlen);
16433 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
16434 	} else {
16435 		th->th_off = sizeof(struct tcphdr) >> 2;
16436 	}
16437 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
16438 		union tcp_log_stackspecific log;
16439 
16440 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
16441 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
16442 		if (rack->rack_no_prr)
16443 			log.u_bbr.flex1 = 0;
16444 		else
16445 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
16446 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
16447 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
16448 		log.u_bbr.flex4 = max_val;
16449 		log.u_bbr.flex5 = 0;
16450 		/* Save off the early/late values */
16451 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
16452 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
16453 		log.u_bbr.bw_inuse = rack_get_bw(rack);
16454 		log.u_bbr.flex8 = 0;
16455 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
16456 		log.u_bbr.flex7 = 44;
16457 		log.u_bbr.pkts_out = tp->t_maxseg;
16458 		log.u_bbr.timeStamp = cts;
16459 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
16460 		log.u_bbr.lt_epoch = rack->r_ctl.cwnd_to_use;
16461 		log.u_bbr.delivered = 0;
16462 		lgb = tcp_log_event_(tp, th, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
16463 				     len, &log, false, NULL, NULL, 0, tv);
16464 	} else
16465 		lgb = NULL;
16466 #ifdef INET6
16467 	if (rack->r_is_v6) {
16468 		error = ip6_output(m, NULL,
16469 				   &inp->inp_route6,
16470 				   0, NULL, NULL, inp);
16471 	}
16472 #endif
16473 #if defined(INET) && defined(INET6)
16474 	else
16475 #endif
16476 #ifdef INET
16477 	{
16478 		error = ip_output(m, NULL,
16479 				  &inp->inp_route,
16480 				  0, 0, inp);
16481 	}
16482 #endif
16483 	if (lgb) {
16484 		lgb->tlb_errno = error;
16485 		lgb = NULL;
16486 	}
16487 	if (error) {
16488 		*send_err = error;
16489 		m = NULL;
16490 		goto failed;
16491 	}
16492 	rack_log_output(tp, &to, len, tp->snd_max, flags, error, rack_to_usec_ts(tv),
16493 			NULL, add_flag, s_mb, s_soff, rack->r_ctl.fsb.hw_tls);
16494 	m = NULL;
16495 	if (tp->snd_una == tp->snd_max) {
16496 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
16497 		rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
16498 		tp->t_acktime = ticks;
16499 	}
16500 	if (error == 0)
16501 		tcp_account_for_send(tp, len, 0, 0, rack->r_ctl.fsb.hw_tls);
16502 
16503 	rack->forced_ack = 0;	/* If we send something zap the FA flag */
16504 	tot_len += len;
16505 	if ((tp->t_flags & TF_GPUTINPROG) == 0)
16506 		rack_start_gp_measurement(tp, rack, tp->snd_max, sb_offset);
16507 	tp->snd_max += len;
16508 	tp->snd_nxt = tp->snd_max;
16509 	{
16510 		int idx;
16511 
16512 		idx = (len / segsiz) + 3;
16513 		if (idx >= TCP_MSS_ACCT_ATIMER)
16514 			counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
16515 		else
16516 			counter_u64_add(rack_out_size[idx], 1);
16517 	}
16518 	if (len <= rack->r_ctl.fsb.left_to_send)
16519 		rack->r_ctl.fsb.left_to_send -= len;
16520 	else
16521 		rack->r_ctl.fsb.left_to_send = 0;
16522 	if (rack->r_ctl.fsb.left_to_send < segsiz) {
16523 		rack->r_fast_output = 0;
16524 		rack->r_ctl.fsb.left_to_send = 0;
16525 		/* At the end of fast_output scale up the sb */
16526 		SOCKBUF_LOCK(&rack->rc_inp->inp_socket->so_snd);
16527 		rack_sndbuf_autoscale(rack);
16528 		SOCKBUF_UNLOCK(&rack->rc_inp->inp_socket->so_snd);
16529 	}
16530 	if (tp->t_rtttime == 0) {
16531 		tp->t_rtttime = ticks;
16532 		tp->t_rtseq = startseq;
16533 		KMOD_TCPSTAT_INC(tcps_segstimed);
16534 	}
16535 	if ((rack->r_ctl.fsb.left_to_send >= segsiz) &&
16536 	    (max_val > len) &&
16537 	    (tso == 0)) {
16538 		max_val -= len;
16539 		len = segsiz;
16540 		th = rack->r_ctl.fsb.th;
16541 #ifdef TCP_ACCOUNTING
16542 		cnt_thru++;
16543 #endif
16544 		goto again;
16545 	}
16546 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
16547 	counter_u64_add(rack_fto_send, 1);
16548 	slot = rack_get_pacing_delay(rack, tp, tot_len, NULL, segsiz);
16549 	rack_start_hpts_timer(rack, tp, cts, slot, tot_len, 0);
16550 #ifdef TCP_ACCOUNTING
16551 	crtsc = get_cyclecount();
16552 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16553 		tp->tcp_cnt_counters[SND_OUT_DATA] += cnt_thru;
16554 	}
16555 	counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], cnt_thru);
16556 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16557 		tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
16558 	}
16559 	counter_u64_add(tcp_proc_time[SND_OUT_DATA], (crtsc - ts_val));
16560 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16561 		tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len + segsiz - 1) / segsiz);
16562 	}
16563 	counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((tot_len + segsiz - 1) / segsiz));
16564 	sched_unpin();
16565 #endif
16566 	return (0);
16567 failed:
16568 	if (m)
16569 		m_free(m);
16570 	rack->r_fast_output = 0;
16571 	return (-1);
16572 }
16573 
16574 static struct rack_sendmap *
16575 rack_check_collapsed(struct tcp_rack *rack, uint32_t cts)
16576 {
16577 	struct rack_sendmap *rsm = NULL;
16578 	struct rack_sendmap fe;
16579 	int thresh;
16580 
16581 restart:
16582 	fe.r_start = rack->r_ctl.last_collapse_point;
16583 	rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
16584 	if ((rsm == NULL) || ((rsm->r_flags & RACK_RWND_COLLAPSED) == 0)) {
16585 		/* Nothing, strange turn off validity  */
16586 		rack->r_collapse_point_valid = 0;
16587 		return (NULL);
16588 	}
16589 	/* Can we send it yet? */
16590 	if (rsm->r_end > (rack->rc_tp->snd_una + rack->rc_tp->snd_wnd)) {
16591 		/*
16592 		 * Receiver window has not grown enough for
16593 		 * the segment to be put on the wire.
16594 		 */
16595 		return (NULL);
16596 	}
16597 	if (rsm->r_flags & RACK_ACKED) {
16598 		/*
16599 		 * It has been sacked, lets move to the
16600 		 * next one if possible.
16601 		 */
16602 		rack->r_ctl.last_collapse_point = rsm->r_end;
16603 		/* Are we done? */
16604 		if (SEQ_GEQ(rack->r_ctl.last_collapse_point,
16605 			    rack->r_ctl.high_collapse_point)) {
16606 			rack->r_collapse_point_valid = 0;
16607 			return (NULL);
16608 		}
16609 		goto restart;
16610 	}
16611 	/* Now has it been long enough ? */
16612 	thresh = rack_calc_thresh_rack(rack, rack_grab_rtt(rack->rc_tp, rack), cts);
16613 	if ((cts - ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)])) > thresh) {
16614 		rack_log_collapse(rack, rsm->r_start,
16615 				  (cts - ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)])),
16616 				  thresh, __LINE__, 6, rsm->r_flags, rsm);
16617 		return (rsm);
16618 	}
16619 	/* Not enough time */
16620 	rack_log_collapse(rack, rsm->r_start,
16621 			  (cts - ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)])),
16622 			  thresh, __LINE__, 7, rsm->r_flags, rsm);
16623 	return (NULL);
16624 }
16625 
16626 static int
16627 rack_output(struct tcpcb *tp)
16628 {
16629 	struct socket *so;
16630 	uint32_t recwin;
16631 	uint32_t sb_offset, s_moff = 0;
16632 	int32_t len, error = 0;
16633 	uint16_t flags;
16634 	struct mbuf *m, *s_mb = NULL;
16635 	struct mbuf *mb;
16636 	uint32_t if_hw_tsomaxsegcount = 0;
16637 	uint32_t if_hw_tsomaxsegsize;
16638 	int32_t segsiz, minseg;
16639 	long tot_len_this_send = 0;
16640 #ifdef INET
16641 	struct ip *ip = NULL;
16642 #endif
16643 	struct udphdr *udp = NULL;
16644 	struct tcp_rack *rack;
16645 	struct tcphdr *th;
16646 	uint8_t pass = 0;
16647 	uint8_t mark = 0;
16648 	uint8_t wanted_cookie = 0;
16649 	u_char opt[TCP_MAXOLEN];
16650 	unsigned ipoptlen, optlen, hdrlen, ulen=0;
16651 	uint32_t rack_seq;
16652 
16653 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
16654 	unsigned ipsec_optlen = 0;
16655 
16656 #endif
16657 	int32_t idle, sendalot;
16658 	int32_t sub_from_prr = 0;
16659 	volatile int32_t sack_rxmit;
16660 	struct rack_sendmap *rsm = NULL;
16661 	int32_t tso, mtu;
16662 	struct tcpopt to;
16663 	int32_t slot = 0;
16664 	int32_t sup_rack = 0;
16665 	uint32_t cts, ms_cts, delayed, early;
16666 	uint16_t add_flag = RACK_SENT_SP;
16667 	/* The doing_tlp flag will be set by the actual rack_timeout_tlp() */
16668 	uint8_t hpts_calling,  doing_tlp = 0;
16669 	uint32_t cwnd_to_use, pace_max_seg;
16670 	int32_t do_a_prefetch = 0;
16671 	int32_t prefetch_rsm = 0;
16672 	int32_t orig_len = 0;
16673 	struct timeval tv;
16674 	int32_t prefetch_so_done = 0;
16675 	struct tcp_log_buffer *lgb;
16676 	struct inpcb *inp = tptoinpcb(tp);
16677 	struct sockbuf *sb;
16678 	uint64_t ts_val = 0;
16679 #ifdef TCP_ACCOUNTING
16680 	uint64_t crtsc;
16681 #endif
16682 #ifdef INET6
16683 	struct ip6_hdr *ip6 = NULL;
16684 	int32_t isipv6;
16685 #endif
16686 	bool hw_tls = false;
16687 
16688 	NET_EPOCH_ASSERT();
16689 	INP_WLOCK_ASSERT(inp);
16690 
16691 	/* setup and take the cache hits here */
16692 	rack = (struct tcp_rack *)tp->t_fb_ptr;
16693 #ifdef TCP_ACCOUNTING
16694 	sched_pin();
16695 	ts_val = get_cyclecount();
16696 #endif
16697 	hpts_calling = inp->inp_hpts_calls;
16698 #ifdef TCP_OFFLOAD
16699 	if (tp->t_flags & TF_TOE) {
16700 #ifdef TCP_ACCOUNTING
16701 		sched_unpin();
16702 #endif
16703 		return (tcp_offload_output(tp));
16704 	}
16705 #endif
16706 	/*
16707 	 * For TFO connections in SYN_RECEIVED, only allow the initial
16708 	 * SYN|ACK and those sent by the retransmit timer.
16709 	 */
16710 	if (IS_FASTOPEN(tp->t_flags) &&
16711 	    (tp->t_state == TCPS_SYN_RECEIVED) &&
16712 	    SEQ_GT(tp->snd_max, tp->snd_una) &&    /* initial SYN|ACK sent */
16713 	    (rack->r_ctl.rc_resend == NULL)) {         /* not a retransmit */
16714 #ifdef TCP_ACCOUNTING
16715 		sched_unpin();
16716 #endif
16717 		return (0);
16718 	}
16719 #ifdef INET6
16720 	if (rack->r_state) {
16721 		/* Use the cache line loaded if possible */
16722 		isipv6 = rack->r_is_v6;
16723 	} else {
16724 		isipv6 = (rack->rc_inp->inp_vflag & INP_IPV6) != 0;
16725 	}
16726 #endif
16727 	early = 0;
16728 	cts = tcp_get_usecs(&tv);
16729 	ms_cts = tcp_tv_to_mssectick(&tv);
16730 	if (((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) &&
16731 	    tcp_in_hpts(rack->rc_inp)) {
16732 		/*
16733 		 * We are on the hpts for some timer but not hptsi output.
16734 		 * Remove from the hpts unconditionally.
16735 		 */
16736 		rack_timer_cancel(tp, rack, cts, __LINE__);
16737 	}
16738 	/* Are we pacing and late? */
16739 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
16740 	    TSTMP_GEQ(cts, rack->r_ctl.rc_last_output_to)) {
16741 		/* We are delayed */
16742 		delayed = cts - rack->r_ctl.rc_last_output_to;
16743 	} else {
16744 		delayed = 0;
16745 	}
16746 	/* Do the timers, which may override the pacer */
16747 	if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
16748 		int retval;
16749 
16750 		retval = rack_process_timers(tp, rack, cts, hpts_calling,
16751 		    &doing_tlp);
16752 		if (retval != 0) {
16753 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_ATIMER], 1);
16754 #ifdef TCP_ACCOUNTING
16755 			sched_unpin();
16756 #endif
16757 			/*
16758 			 * If timers want tcp_drop(), then pass error out,
16759 			 * otherwise suppress it.
16760 			 */
16761 			return (retval < 0 ? retval : 0);
16762 		}
16763 	}
16764 	if (rack->rc_in_persist) {
16765 		if (tcp_in_hpts(rack->rc_inp) == 0) {
16766 			/* Timer is not running */
16767 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
16768 		}
16769 #ifdef TCP_ACCOUNTING
16770 		sched_unpin();
16771 #endif
16772 		return (0);
16773 	}
16774 	if ((rack->rc_ack_required == 1) &&
16775 	    (rack->r_timer_override == 0)){
16776 		/* A timeout occurred and no ack has arrived */
16777 		if (tcp_in_hpts(rack->rc_inp) == 0) {
16778 			/* Timer is not running */
16779 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
16780 		}
16781 #ifdef TCP_ACCOUNTING
16782 		sched_unpin();
16783 #endif
16784 		return (0);
16785 	}
16786 	if ((rack->r_timer_override) ||
16787 	    (rack->rc_ack_can_sendout_data) ||
16788 	    (delayed) ||
16789 	    (tp->t_state < TCPS_ESTABLISHED)) {
16790 		rack->rc_ack_can_sendout_data = 0;
16791 		if (tcp_in_hpts(rack->rc_inp))
16792 			tcp_hpts_remove(rack->rc_inp);
16793 	} else if (tcp_in_hpts(rack->rc_inp)) {
16794 		/*
16795 		 * On the hpts you can't pass even if ACKNOW is on, we will
16796 		 * when the hpts fires.
16797 		 */
16798 #ifdef TCP_ACCOUNTING
16799 		crtsc = get_cyclecount();
16800 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16801 			tp->tcp_proc_time[SND_BLOCKED] += (crtsc - ts_val);
16802 		}
16803 		counter_u64_add(tcp_proc_time[SND_BLOCKED], (crtsc - ts_val));
16804 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16805 			tp->tcp_cnt_counters[SND_BLOCKED]++;
16806 		}
16807 		counter_u64_add(tcp_cnt_counters[SND_BLOCKED], 1);
16808 		sched_unpin();
16809 #endif
16810 		counter_u64_add(rack_out_size[TCP_MSS_ACCT_INPACE], 1);
16811 		return (0);
16812 	}
16813 	rack->rc_inp->inp_hpts_calls = 0;
16814 	/* Finish out both pacing early and late accounting */
16815 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
16816 	    TSTMP_GT(rack->r_ctl.rc_last_output_to, cts)) {
16817 		early = rack->r_ctl.rc_last_output_to - cts;
16818 	} else
16819 		early = 0;
16820 	if (delayed) {
16821 		rack->r_ctl.rc_agg_delayed += delayed;
16822 		rack->r_late = 1;
16823 	} else if (early) {
16824 		rack->r_ctl.rc_agg_early += early;
16825 		rack->r_early = 1;
16826 	}
16827 	/* Now that early/late accounting is done turn off the flag */
16828 	rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
16829 	rack->r_wanted_output = 0;
16830 	rack->r_timer_override = 0;
16831 	if ((tp->t_state != rack->r_state) &&
16832 	    TCPS_HAVEESTABLISHED(tp->t_state)) {
16833 		rack_set_state(tp, rack);
16834 	}
16835 	if ((rack->r_fast_output) &&
16836 	    (doing_tlp == 0) &&
16837 	    (tp->rcv_numsacks == 0)) {
16838 		int ret;
16839 
16840 		error = 0;
16841 		ret = rack_fast_output(tp, rack, ts_val, cts, ms_cts, &tv, tot_len_this_send, &error);
16842 		if (ret >= 0)
16843 			return(ret);
16844 		else if (error) {
16845 			inp = rack->rc_inp;
16846 			so = inp->inp_socket;
16847 			sb = &so->so_snd;
16848 			goto nomore;
16849 		}
16850 	}
16851 	inp = rack->rc_inp;
16852 	/*
16853 	 * For TFO connections in SYN_SENT or SYN_RECEIVED,
16854 	 * only allow the initial SYN or SYN|ACK and those sent
16855 	 * by the retransmit timer.
16856 	 */
16857 	if (IS_FASTOPEN(tp->t_flags) &&
16858 	    ((tp->t_state == TCPS_SYN_RECEIVED) ||
16859 	     (tp->t_state == TCPS_SYN_SENT)) &&
16860 	    SEQ_GT(tp->snd_max, tp->snd_una) && /* initial SYN or SYN|ACK sent */
16861 	    (tp->t_rxtshift == 0)) {              /* not a retransmit */
16862 		cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
16863 		so = inp->inp_socket;
16864 		sb = &so->so_snd;
16865 		goto just_return_nolock;
16866 	}
16867 	/*
16868 	 * Determine length of data that should be transmitted, and flags
16869 	 * that will be used. If there is some data or critical controls
16870 	 * (SYN, RST) to send, then transmit; otherwise, investigate
16871 	 * further.
16872 	 */
16873 	idle = (tp->t_flags & TF_LASTIDLE) || (tp->snd_max == tp->snd_una);
16874 	if (tp->t_idle_reduce) {
16875 		if (idle && (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur))
16876 			rack_cc_after_idle(rack, tp);
16877 	}
16878 	tp->t_flags &= ~TF_LASTIDLE;
16879 	if (idle) {
16880 		if (tp->t_flags & TF_MORETOCOME) {
16881 			tp->t_flags |= TF_LASTIDLE;
16882 			idle = 0;
16883 		}
16884 	}
16885 	if ((tp->snd_una == tp->snd_max) &&
16886 	    rack->r_ctl.rc_went_idle_time &&
16887 	    TSTMP_GT(cts, rack->r_ctl.rc_went_idle_time)) {
16888 		idle = cts - rack->r_ctl.rc_went_idle_time;
16889 		if (idle > rack_min_probertt_hold) {
16890 			/* Count as a probe rtt */
16891 			if (rack->in_probe_rtt == 0) {
16892 				rack->r_ctl.rc_lower_rtt_us_cts = cts;
16893 				rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
16894 				rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
16895 				rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
16896 			} else {
16897 				rack_exit_probertt(rack, cts);
16898 			}
16899 		}
16900 		idle = 0;
16901 	}
16902 	if (rack_use_fsb && (rack->r_fsb_inited == 0) && (rack->r_state != TCPS_CLOSED))
16903 		rack_init_fsb_block(tp, rack);
16904 again:
16905 	/*
16906 	 * If we've recently taken a timeout, snd_max will be greater than
16907 	 * snd_nxt.  There may be SACK information that allows us to avoid
16908 	 * resending already delivered data.  Adjust snd_nxt accordingly.
16909 	 */
16910 	sendalot = 0;
16911 	cts = tcp_get_usecs(&tv);
16912 	ms_cts = tcp_tv_to_mssectick(&tv);
16913 	tso = 0;
16914 	mtu = 0;
16915 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
16916 	minseg = segsiz;
16917 	if (rack->r_ctl.rc_pace_max_segs == 0)
16918 		pace_max_seg = rack->rc_user_set_max_segs * segsiz;
16919 	else
16920 		pace_max_seg = rack->r_ctl.rc_pace_max_segs;
16921 	sb_offset = tp->snd_max - tp->snd_una;
16922 	cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
16923 	flags = tcp_outflags[tp->t_state];
16924 	while (rack->rc_free_cnt < rack_free_cache) {
16925 		rsm = rack_alloc(rack);
16926 		if (rsm == NULL) {
16927 			if (inp->inp_hpts_calls)
16928 				/* Retry in a ms */
16929 				slot = (1 * HPTS_USEC_IN_MSEC);
16930 			so = inp->inp_socket;
16931 			sb = &so->so_snd;
16932 			goto just_return_nolock;
16933 		}
16934 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_free, rsm, r_tnext);
16935 		rack->rc_free_cnt++;
16936 		rsm = NULL;
16937 	}
16938 	if (inp->inp_hpts_calls)
16939 		inp->inp_hpts_calls = 0;
16940 	sack_rxmit = 0;
16941 	len = 0;
16942 	rsm = NULL;
16943 	if (flags & TH_RST) {
16944 		SOCKBUF_LOCK(&inp->inp_socket->so_snd);
16945 		so = inp->inp_socket;
16946 		sb = &so->so_snd;
16947 		goto send;
16948 	}
16949 	if (rack->r_ctl.rc_resend) {
16950 		/* Retransmit timer */
16951 		rsm = rack->r_ctl.rc_resend;
16952 		rack->r_ctl.rc_resend = NULL;
16953 		len = rsm->r_end - rsm->r_start;
16954 		sack_rxmit = 1;
16955 		sendalot = 0;
16956 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
16957 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
16958 			 __func__, __LINE__,
16959 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
16960 		sb_offset = rsm->r_start - tp->snd_una;
16961 		if (len >= segsiz)
16962 			len = segsiz;
16963 	} else if (rack->r_collapse_point_valid &&
16964 		   ((rsm = rack_check_collapsed(rack, cts)) != NULL)) {
16965 		/*
16966 		 * If an RSM is returned then enough time has passed
16967 		 * for us to retransmit it. Move up the collapse point,
16968 		 * since this rsm has its chance to retransmit now.
16969 		 */
16970 		rack_trace_point(rack, RACK_TP_COLLAPSED_RXT);
16971 		rack->r_ctl.last_collapse_point = rsm->r_end;
16972 		/* Are we done? */
16973 		if (SEQ_GEQ(rack->r_ctl.last_collapse_point,
16974 			    rack->r_ctl.high_collapse_point))
16975 			rack->r_collapse_point_valid = 0;
16976 		sack_rxmit = 1;
16977 		/* We are not doing a TLP */
16978 		doing_tlp = 0;
16979 		len = rsm->r_end - rsm->r_start;
16980 		sb_offset = rsm->r_start - tp->snd_una;
16981 		sendalot = 0;
16982 		if ((rack->full_size_rxt == 0) &&
16983 		    (rack->shape_rxt_to_pacing_min == 0) &&
16984 		    (len >= segsiz))
16985 			len = segsiz;
16986 	} else if ((rsm = tcp_rack_output(tp, rack, cts)) != NULL) {
16987 		/* We have a retransmit that takes precedence */
16988 		if ((!IN_FASTRECOVERY(tp->t_flags)) &&
16989 		    ((rsm->r_flags & RACK_MUST_RXT) == 0) &&
16990 		    ((tp->t_flags & TF_WASFRECOVERY) == 0)) {
16991 			/* Enter recovery if not induced by a time-out */
16992 			rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
16993 		}
16994 #ifdef INVARIANTS
16995 		if (SEQ_LT(rsm->r_start, tp->snd_una)) {
16996 			panic("Huh, tp:%p rack:%p rsm:%p start:%u < snd_una:%u\n",
16997 			      tp, rack, rsm, rsm->r_start, tp->snd_una);
16998 		}
16999 #endif
17000 		len = rsm->r_end - rsm->r_start;
17001 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
17002 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
17003 			 __func__, __LINE__,
17004 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
17005 		sb_offset = rsm->r_start - tp->snd_una;
17006 		sendalot = 0;
17007 		if (len >= segsiz)
17008 			len = segsiz;
17009 		if (len > 0) {
17010 			sack_rxmit = 1;
17011 			KMOD_TCPSTAT_INC(tcps_sack_rexmits);
17012 			KMOD_TCPSTAT_ADD(tcps_sack_rexmit_bytes,
17013 			    min(len, segsiz));
17014 		}
17015 	} else if (rack->r_ctl.rc_tlpsend) {
17016 		/* Tail loss probe */
17017 		long cwin;
17018 		long tlen;
17019 
17020 		/*
17021 		 * Check if we can do a TLP with a RACK'd packet
17022 		 * this can happen if we are not doing the rack
17023 		 * cheat and we skipped to a TLP and it
17024 		 * went off.
17025 		 */
17026 		rsm = rack->r_ctl.rc_tlpsend;
17027 		/* We are doing a TLP make sure the flag is preent */
17028 		rsm->r_flags |= RACK_TLP;
17029 		rack->r_ctl.rc_tlpsend = NULL;
17030 		sack_rxmit = 1;
17031 		tlen = rsm->r_end - rsm->r_start;
17032 		if (tlen > segsiz)
17033 			tlen = segsiz;
17034 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
17035 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
17036 			 __func__, __LINE__,
17037 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
17038 		sb_offset = rsm->r_start - tp->snd_una;
17039 		cwin = min(tp->snd_wnd, tlen);
17040 		len = cwin;
17041 	}
17042 	if (rack->r_must_retran &&
17043 	    (doing_tlp == 0) &&
17044 	    (SEQ_GT(tp->snd_max, tp->snd_una)) &&
17045 	    (rsm == NULL)) {
17046 		/*
17047 		 * There are two different ways that we
17048 		 * can get into this block:
17049 		 * a) This is a non-sack connection, we had a time-out
17050 		 *    and thus r_must_retran was set and everything
17051 		 *    left outstanding as been marked for retransmit.
17052 		 * b) The MTU of the path shrank, so that everything
17053 		 *    was marked to be retransmitted with the smaller
17054 		 *    mtu and r_must_retran was set.
17055 		 *
17056 		 * This means that we expect the sendmap (outstanding)
17057 		 * to all be marked must. We can use the tmap to
17058 		 * look at them.
17059 		 *
17060 		 */
17061 		int sendwin, flight;
17062 
17063 		sendwin = min(tp->snd_wnd, tp->snd_cwnd);
17064 		flight = ctf_flight_size(tp, rack->r_ctl.rc_out_at_rto);
17065 		if (flight >= sendwin) {
17066 			/*
17067 			 * We can't send yet.
17068 			 */
17069 			so = inp->inp_socket;
17070 			sb = &so->so_snd;
17071 			goto just_return_nolock;
17072 		}
17073 		/*
17074 		 * This is the case a/b mentioned above. All
17075 		 * outstanding/not-acked should be marked.
17076 		 * We can use the tmap to find them.
17077 		 */
17078 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
17079 		if (rsm == NULL) {
17080 			/* TSNH */
17081 			rack->r_must_retran = 0;
17082 			rack->r_ctl.rc_out_at_rto = 0;
17083 			so = inp->inp_socket;
17084 			sb = &so->so_snd;
17085 			goto just_return_nolock;
17086 		}
17087 		if ((rsm->r_flags & RACK_MUST_RXT) == 0) {
17088 			/*
17089 			 * The first one does not have the flag, did we collapse
17090 			 * further up in our list?
17091 			 */
17092 			rack->r_must_retran = 0;
17093 			rack->r_ctl.rc_out_at_rto = 0;
17094 			rsm = NULL;
17095 			sack_rxmit = 0;
17096 		} else {
17097 			sack_rxmit = 1;
17098 			len = rsm->r_end - rsm->r_start;
17099 			sb_offset = rsm->r_start - tp->snd_una;
17100 			sendalot = 0;
17101 			if ((rack->full_size_rxt == 0) &&
17102 			    (rack->shape_rxt_to_pacing_min == 0) &&
17103 			    (len >= segsiz))
17104 				len = segsiz;
17105 			/*
17106 			 * Delay removing the flag RACK_MUST_RXT so
17107 			 * that the fastpath for retransmit will
17108 			 * work with this rsm.
17109 			 */
17110 		}
17111 	}
17112 	/*
17113 	 * Enforce a connection sendmap count limit if set
17114 	 * as long as we are not retransmiting.
17115 	 */
17116 	if ((rsm == NULL) &&
17117 	    (rack->do_detection == 0) &&
17118 	    (V_tcp_map_entries_limit > 0) &&
17119 	    (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
17120 		counter_u64_add(rack_to_alloc_limited, 1);
17121 		if (!rack->alloc_limit_reported) {
17122 			rack->alloc_limit_reported = 1;
17123 			counter_u64_add(rack_alloc_limited_conns, 1);
17124 		}
17125 		so = inp->inp_socket;
17126 		sb = &so->so_snd;
17127 		goto just_return_nolock;
17128 	}
17129 	if (rsm && (rsm->r_flags & RACK_HAS_FIN)) {
17130 		/* we are retransmitting the fin */
17131 		len--;
17132 		if (len) {
17133 			/*
17134 			 * When retransmitting data do *not* include the
17135 			 * FIN. This could happen from a TLP probe.
17136 			 */
17137 			flags &= ~TH_FIN;
17138 		}
17139 	}
17140 	if (rsm && rack->r_fsb_inited && rack_use_rsm_rfo &&
17141 	    ((rsm->r_flags & RACK_HAS_FIN) == 0)) {
17142 		int ret;
17143 
17144 		ret = rack_fast_rsm_output(tp, rack, rsm, ts_val, cts, ms_cts, &tv, len, doing_tlp);
17145 		if (ret == 0)
17146 			return (0);
17147 	}
17148 	so = inp->inp_socket;
17149 	sb = &so->so_snd;
17150 	if (do_a_prefetch == 0) {
17151 		kern_prefetch(sb, &do_a_prefetch);
17152 		do_a_prefetch = 1;
17153 	}
17154 #ifdef NETFLIX_SHARED_CWND
17155 	if ((tp->t_flags2 & TF2_TCP_SCWND_ALLOWED) &&
17156 	    rack->rack_enable_scwnd) {
17157 		/* We are doing cwnd sharing */
17158 		if (rack->gp_ready &&
17159 		    (rack->rack_attempted_scwnd == 0) &&
17160 		    (rack->r_ctl.rc_scw == NULL) &&
17161 		    tp->t_lib) {
17162 			/* The pcbid is in, lets make an attempt */
17163 			counter_u64_add(rack_try_scwnd, 1);
17164 			rack->rack_attempted_scwnd = 1;
17165 			rack->r_ctl.rc_scw = tcp_shared_cwnd_alloc(tp,
17166 								   &rack->r_ctl.rc_scw_index,
17167 								   segsiz);
17168 		}
17169 		if (rack->r_ctl.rc_scw &&
17170 		    (rack->rack_scwnd_is_idle == 1) &&
17171 		    sbavail(&so->so_snd)) {
17172 			/* we are no longer out of data */
17173 			tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
17174 			rack->rack_scwnd_is_idle = 0;
17175 		}
17176 		if (rack->r_ctl.rc_scw) {
17177 			/* First lets update and get the cwnd */
17178 			rack->r_ctl.cwnd_to_use = cwnd_to_use = tcp_shared_cwnd_update(rack->r_ctl.rc_scw,
17179 								    rack->r_ctl.rc_scw_index,
17180 								    tp->snd_cwnd, tp->snd_wnd, segsiz);
17181 		}
17182 	}
17183 #endif
17184 	/*
17185 	 * Get standard flags, and add SYN or FIN if requested by 'hidden'
17186 	 * state flags.
17187 	 */
17188 	if (tp->t_flags & TF_NEEDFIN)
17189 		flags |= TH_FIN;
17190 	if (tp->t_flags & TF_NEEDSYN)
17191 		flags |= TH_SYN;
17192 	if ((sack_rxmit == 0) && (prefetch_rsm == 0)) {
17193 		void *end_rsm;
17194 		end_rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
17195 		if (end_rsm)
17196 			kern_prefetch(end_rsm, &prefetch_rsm);
17197 		prefetch_rsm = 1;
17198 	}
17199 	SOCKBUF_LOCK(sb);
17200 	/*
17201 	 * If snd_nxt == snd_max and we have transmitted a FIN, the
17202 	 * sb_offset will be > 0 even if so_snd.sb_cc is 0, resulting in a
17203 	 * negative length.  This can also occur when TCP opens up its
17204 	 * congestion window while receiving additional duplicate acks after
17205 	 * fast-retransmit because TCP will reset snd_nxt to snd_max after
17206 	 * the fast-retransmit.
17207 	 *
17208 	 * In the normal retransmit-FIN-only case, however, snd_nxt will be
17209 	 * set to snd_una, the sb_offset will be 0, and the length may wind
17210 	 * up 0.
17211 	 *
17212 	 * If sack_rxmit is true we are retransmitting from the scoreboard
17213 	 * in which case len is already set.
17214 	 */
17215 	if ((sack_rxmit == 0) &&
17216 	    (TCPS_HAVEESTABLISHED(tp->t_state) || IS_FASTOPEN(tp->t_flags))) {
17217 		uint32_t avail;
17218 
17219 		avail = sbavail(sb);
17220 		if (SEQ_GT(tp->snd_nxt, tp->snd_una) && avail)
17221 			sb_offset = tp->snd_nxt - tp->snd_una;
17222 		else
17223 			sb_offset = 0;
17224 		if ((IN_FASTRECOVERY(tp->t_flags) == 0) || rack->rack_no_prr) {
17225 			if (rack->r_ctl.rc_tlp_new_data) {
17226 				/* TLP is forcing out new data */
17227 				if (rack->r_ctl.rc_tlp_new_data > (uint32_t) (avail - sb_offset)) {
17228 					rack->r_ctl.rc_tlp_new_data = (uint32_t) (avail - sb_offset);
17229 				}
17230 				if ((rack->r_ctl.rc_tlp_new_data + sb_offset) > tp->snd_wnd) {
17231 					if (tp->snd_wnd > sb_offset)
17232 						len = tp->snd_wnd - sb_offset;
17233 					else
17234 						len = 0;
17235 				} else {
17236 					len = rack->r_ctl.rc_tlp_new_data;
17237 				}
17238 				rack->r_ctl.rc_tlp_new_data = 0;
17239 			}  else {
17240 				len = rack_what_can_we_send(tp, rack, cwnd_to_use, avail, sb_offset);
17241 			}
17242 			if ((rack->r_ctl.crte == NULL) && IN_FASTRECOVERY(tp->t_flags) && (len > segsiz)) {
17243 				/*
17244 				 * For prr=off, we need to send only 1 MSS
17245 				 * at a time. We do this because another sack could
17246 				 * be arriving that causes us to send retransmits and
17247 				 * we don't want to be on a long pace due to a larger send
17248 				 * that keeps us from sending out the retransmit.
17249 				 */
17250 				len = segsiz;
17251 			}
17252 		} else {
17253 			uint32_t outstanding;
17254 			/*
17255 			 * We are inside of a Fast recovery episode, this
17256 			 * is caused by a SACK or 3 dup acks. At this point
17257 			 * we have sent all the retransmissions and we rely
17258 			 * on PRR to dictate what we will send in the form of
17259 			 * new data.
17260 			 */
17261 
17262 			outstanding = tp->snd_max - tp->snd_una;
17263 			if ((rack->r_ctl.rc_prr_sndcnt + outstanding) > tp->snd_wnd) {
17264 				if (tp->snd_wnd > outstanding) {
17265 					len = tp->snd_wnd - outstanding;
17266 					/* Check to see if we have the data */
17267 					if ((sb_offset + len) > avail) {
17268 						/* It does not all fit */
17269 						if (avail > sb_offset)
17270 							len = avail - sb_offset;
17271 						else
17272 							len = 0;
17273 					}
17274 				} else {
17275 					len = 0;
17276 				}
17277 			} else if (avail > sb_offset) {
17278 				len = avail - sb_offset;
17279 			} else {
17280 				len = 0;
17281 			}
17282 			if (len > 0) {
17283 				if (len > rack->r_ctl.rc_prr_sndcnt) {
17284 					len = rack->r_ctl.rc_prr_sndcnt;
17285 				}
17286 				if (len > 0) {
17287 					sub_from_prr = 1;
17288 				}
17289 			}
17290 			if (len > segsiz) {
17291 				/*
17292 				 * We should never send more than a MSS when
17293 				 * retransmitting or sending new data in prr
17294 				 * mode unless the override flag is on. Most
17295 				 * likely the PRR algorithm is not going to
17296 				 * let us send a lot as well :-)
17297 				 */
17298 				if (rack->r_ctl.rc_prr_sendalot == 0) {
17299 					len = segsiz;
17300 				}
17301 			} else if (len < segsiz) {
17302 				/*
17303 				 * Do we send any? The idea here is if the
17304 				 * send empty's the socket buffer we want to
17305 				 * do it. However if not then lets just wait
17306 				 * for our prr_sndcnt to get bigger.
17307 				 */
17308 				long leftinsb;
17309 
17310 				leftinsb = sbavail(sb) - sb_offset;
17311 				if (leftinsb > len) {
17312 					/* This send does not empty the sb */
17313 					len = 0;
17314 				}
17315 			}
17316 		}
17317 	} else if (!TCPS_HAVEESTABLISHED(tp->t_state)) {
17318 		/*
17319 		 * If you have not established
17320 		 * and are not doing FAST OPEN
17321 		 * no data please.
17322 		 */
17323 		if ((sack_rxmit == 0) &&
17324 		    (!IS_FASTOPEN(tp->t_flags))){
17325 			len = 0;
17326 			sb_offset = 0;
17327 		}
17328 	}
17329 	if (prefetch_so_done == 0) {
17330 		kern_prefetch(so, &prefetch_so_done);
17331 		prefetch_so_done = 1;
17332 	}
17333 	/*
17334 	 * Lop off SYN bit if it has already been sent.  However, if this is
17335 	 * SYN-SENT state and if segment contains data and if we don't know
17336 	 * that foreign host supports TAO, suppress sending segment.
17337 	 */
17338 	if ((flags & TH_SYN) && SEQ_GT(tp->snd_nxt, tp->snd_una) &&
17339 	    ((sack_rxmit == 0) && (tp->t_rxtshift == 0))) {
17340 		/*
17341 		 * When sending additional segments following a TFO SYN|ACK,
17342 		 * do not include the SYN bit.
17343 		 */
17344 		if (IS_FASTOPEN(tp->t_flags) &&
17345 		    (tp->t_state == TCPS_SYN_RECEIVED))
17346 			flags &= ~TH_SYN;
17347 	}
17348 	/*
17349 	 * Be careful not to send data and/or FIN on SYN segments. This
17350 	 * measure is needed to prevent interoperability problems with not
17351 	 * fully conformant TCP implementations.
17352 	 */
17353 	if ((flags & TH_SYN) && (tp->t_flags & TF_NOOPT)) {
17354 		len = 0;
17355 		flags &= ~TH_FIN;
17356 	}
17357 	/*
17358 	 * On TFO sockets, ensure no data is sent in the following cases:
17359 	 *
17360 	 *  - When retransmitting SYN|ACK on a passively-created socket
17361 	 *
17362 	 *  - When retransmitting SYN on an actively created socket
17363 	 *
17364 	 *  - When sending a zero-length cookie (cookie request) on an
17365 	 *    actively created socket
17366 	 *
17367 	 *  - When the socket is in the CLOSED state (RST is being sent)
17368 	 */
17369 	if (IS_FASTOPEN(tp->t_flags) &&
17370 	    (((flags & TH_SYN) && (tp->t_rxtshift > 0)) ||
17371 	     ((tp->t_state == TCPS_SYN_SENT) &&
17372 	      (tp->t_tfo_client_cookie_len == 0)) ||
17373 	     (flags & TH_RST))) {
17374 		sack_rxmit = 0;
17375 		len = 0;
17376 	}
17377 	/* Without fast-open there should never be data sent on a SYN */
17378 	if ((flags & TH_SYN) && (!IS_FASTOPEN(tp->t_flags))) {
17379 		tp->snd_nxt = tp->iss;
17380 		len = 0;
17381 	}
17382 	if ((len > segsiz) && (tcp_dsack_block_exists(tp))) {
17383 		/* We only send 1 MSS if we have a DSACK block */
17384 		add_flag |= RACK_SENT_W_DSACK;
17385 		len = segsiz;
17386 	}
17387 	orig_len = len;
17388 	if (len <= 0) {
17389 		/*
17390 		 * If FIN has been sent but not acked, but we haven't been
17391 		 * called to retransmit, len will be < 0.  Otherwise, window
17392 		 * shrank after we sent into it.  If window shrank to 0,
17393 		 * cancel pending retransmit, pull snd_nxt back to (closed)
17394 		 * window, and set the persist timer if it isn't already
17395 		 * going.  If the window didn't close completely, just wait
17396 		 * for an ACK.
17397 		 *
17398 		 * We also do a general check here to ensure that we will
17399 		 * set the persist timer when we have data to send, but a
17400 		 * 0-byte window. This makes sure the persist timer is set
17401 		 * even if the packet hits one of the "goto send" lines
17402 		 * below.
17403 		 */
17404 		len = 0;
17405 		if ((tp->snd_wnd == 0) &&
17406 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
17407 		    (tp->snd_una == tp->snd_max) &&
17408 		    (sb_offset < (int)sbavail(sb))) {
17409 			rack_enter_persist(tp, rack, cts);
17410 		}
17411 	} else if ((rsm == NULL) &&
17412 		   (doing_tlp == 0) &&
17413 		   (len < pace_max_seg)) {
17414 		/*
17415 		 * We are not sending a maximum sized segment for
17416 		 * some reason. Should we not send anything (think
17417 		 * sws or persists)?
17418 		 */
17419 		if ((tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
17420 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
17421 		    (len < minseg) &&
17422 		    (len < (int)(sbavail(sb) - sb_offset))) {
17423 			/*
17424 			 * Here the rwnd is less than
17425 			 * the minimum pacing size, this is not a retransmit,
17426 			 * we are established and
17427 			 * the send is not the last in the socket buffer
17428 			 * we send nothing, and we may enter persists
17429 			 * if nothing is outstanding.
17430 			 */
17431 			len = 0;
17432 			if (tp->snd_max == tp->snd_una) {
17433 				/*
17434 				 * Nothing out we can
17435 				 * go into persists.
17436 				 */
17437 				rack_enter_persist(tp, rack, cts);
17438 			}
17439 		     } else if ((cwnd_to_use >= max(minseg, (segsiz * 4))) &&
17440 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
17441 			   (len < (int)(sbavail(sb) - sb_offset)) &&
17442 			   (len < minseg)) {
17443 			/*
17444 			 * Here we are not retransmitting, and
17445 			 * the cwnd is not so small that we could
17446 			 * not send at least a min size (rxt timer
17447 			 * not having gone off), We have 2 segments or
17448 			 * more already in flight, its not the tail end
17449 			 * of the socket buffer  and the cwnd is blocking
17450 			 * us from sending out a minimum pacing segment size.
17451 			 * Lets not send anything.
17452 			 */
17453 			len = 0;
17454 		} else if (((tp->snd_wnd - ctf_outstanding(tp)) <
17455 			    min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
17456 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
17457 			   (len < (int)(sbavail(sb) - sb_offset)) &&
17458 			   (TCPS_HAVEESTABLISHED(tp->t_state))) {
17459 			/*
17460 			 * Here we have a send window but we have
17461 			 * filled it up and we can't send another pacing segment.
17462 			 * We also have in flight more than 2 segments
17463 			 * and we are not completing the sb i.e. we allow
17464 			 * the last bytes of the sb to go out even if
17465 			 * its not a full pacing segment.
17466 			 */
17467 			len = 0;
17468 		} else if ((rack->r_ctl.crte != NULL) &&
17469 			   (tp->snd_wnd >= (pace_max_seg * max(1, rack_hw_rwnd_factor))) &&
17470 			   (cwnd_to_use >= (pace_max_seg + (4 * segsiz))) &&
17471 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) >= (2 * segsiz)) &&
17472 			   (len < (int)(sbavail(sb) - sb_offset))) {
17473 			/*
17474 			 * Here we are doing hardware pacing, this is not a TLP,
17475 			 * we are not sending a pace max segment size, there is rwnd
17476 			 * room to send at least N pace_max_seg, the cwnd is greater
17477 			 * than or equal to a full pacing segments plus 4 mss and we have 2 or
17478 			 * more segments in flight and its not the tail of the socket buffer.
17479 			 *
17480 			 * We don't want to send instead we need to get more ack's in to
17481 			 * allow us to send a full pacing segment. Normally, if we are pacing
17482 			 * about the right speed, we should have finished our pacing
17483 			 * send as most of the acks have come back if we are at the
17484 			 * right rate. This is a bit fuzzy since return path delay
17485 			 * can delay the acks, which is why we want to make sure we
17486 			 * have cwnd space to have a bit more than a max pace segments in flight.
17487 			 *
17488 			 * If we have not gotten our acks back we are pacing at too high a
17489 			 * rate delaying will not hurt and will bring our GP estimate down by
17490 			 * injecting the delay. If we don't do this we will send
17491 			 * 2 MSS out in response to the acks being clocked in which
17492 			 * defeats the point of hw-pacing (i.e. to help us get
17493 			 * larger TSO's out).
17494 			 */
17495 			len = 0;
17496 
17497 		}
17498 
17499 	}
17500 	/* len will be >= 0 after this point. */
17501 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
17502 	rack_sndbuf_autoscale(rack);
17503 	/*
17504 	 * Decide if we can use TCP Segmentation Offloading (if supported by
17505 	 * hardware).
17506 	 *
17507 	 * TSO may only be used if we are in a pure bulk sending state.  The
17508 	 * presence of TCP-MD5, SACK retransmits, SACK advertizements and IP
17509 	 * options prevent using TSO.  With TSO the TCP header is the same
17510 	 * (except for the sequence number) for all generated packets.  This
17511 	 * makes it impossible to transmit any options which vary per
17512 	 * generated segment or packet.
17513 	 *
17514 	 * IPv4 handling has a clear separation of ip options and ip header
17515 	 * flags while IPv6 combines both in in6p_outputopts. ip6_optlen() does
17516 	 * the right thing below to provide length of just ip options and thus
17517 	 * checking for ipoptlen is enough to decide if ip options are present.
17518 	 */
17519 	ipoptlen = 0;
17520 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
17521 	/*
17522 	 * Pre-calculate here as we save another lookup into the darknesses
17523 	 * of IPsec that way and can actually decide if TSO is ok.
17524 	 */
17525 #ifdef INET6
17526 	if (isipv6 && IPSEC_ENABLED(ipv6))
17527 		ipsec_optlen = IPSEC_HDRSIZE(ipv6, inp);
17528 #ifdef INET
17529 	else
17530 #endif
17531 #endif				/* INET6 */
17532 #ifdef INET
17533 		if (IPSEC_ENABLED(ipv4))
17534 			ipsec_optlen = IPSEC_HDRSIZE(ipv4, inp);
17535 #endif				/* INET */
17536 #endif
17537 
17538 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
17539 	ipoptlen += ipsec_optlen;
17540 #endif
17541 	if ((tp->t_flags & TF_TSO) && V_tcp_do_tso && len > segsiz &&
17542 	    (tp->t_port == 0) &&
17543 	    ((tp->t_flags & TF_SIGNATURE) == 0) &&
17544 	    tp->rcv_numsacks == 0 && sack_rxmit == 0 &&
17545 	    ipoptlen == 0)
17546 		tso = 1;
17547 	{
17548 		uint32_t outstanding __unused;
17549 
17550 		outstanding = tp->snd_max - tp->snd_una;
17551 		if (tp->t_flags & TF_SENTFIN) {
17552 			/*
17553 			 * If we sent a fin, snd_max is 1 higher than
17554 			 * snd_una
17555 			 */
17556 			outstanding--;
17557 		}
17558 		if (sack_rxmit) {
17559 			if ((rsm->r_flags & RACK_HAS_FIN) == 0)
17560 				flags &= ~TH_FIN;
17561 		} else {
17562 			if (SEQ_LT(tp->snd_nxt + len, tp->snd_una +
17563 				   sbused(sb)))
17564 				flags &= ~TH_FIN;
17565 		}
17566 	}
17567 	recwin = lmin(lmax(sbspace(&so->so_rcv), 0),
17568 	    (long)TCP_MAXWIN << tp->rcv_scale);
17569 
17570 	/*
17571 	 * Sender silly window avoidance.   We transmit under the following
17572 	 * conditions when len is non-zero:
17573 	 *
17574 	 * - We have a full segment (or more with TSO) - This is the last
17575 	 * buffer in a write()/send() and we are either idle or running
17576 	 * NODELAY - we've timed out (e.g. persist timer) - we have more
17577 	 * then 1/2 the maximum send window's worth of data (receiver may be
17578 	 * limited the window size) - we need to retransmit
17579 	 */
17580 	if (len) {
17581 		if (len >= segsiz) {
17582 			goto send;
17583 		}
17584 		/*
17585 		 * NOTE! on localhost connections an 'ack' from the remote
17586 		 * end may occur synchronously with the output and cause us
17587 		 * to flush a buffer queued with moretocome.  XXX
17588 		 *
17589 		 */
17590 		if (!(tp->t_flags & TF_MORETOCOME) &&	/* normal case */
17591 		    (idle || (tp->t_flags & TF_NODELAY)) &&
17592 		    ((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
17593 		    (tp->t_flags & TF_NOPUSH) == 0) {
17594 			pass = 2;
17595 			goto send;
17596 		}
17597 		if ((tp->snd_una == tp->snd_max) && len) {	/* Nothing outstanding */
17598 			pass = 22;
17599 			goto send;
17600 		}
17601 		if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0) {
17602 			pass = 4;
17603 			goto send;
17604 		}
17605 		if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {	/* retransmit case */
17606 			pass = 5;
17607 			goto send;
17608 		}
17609 		if (sack_rxmit) {
17610 			pass = 6;
17611 			goto send;
17612 		}
17613 		if (((tp->snd_wnd - ctf_outstanding(tp)) < segsiz) &&
17614 		    (ctf_outstanding(tp) < (segsiz * 2))) {
17615 			/*
17616 			 * We have less than two MSS outstanding (delayed ack)
17617 			 * and our rwnd will not let us send a full sized
17618 			 * MSS. Lets go ahead and let this small segment
17619 			 * out because we want to try to have at least two
17620 			 * packets inflight to not be caught by delayed ack.
17621 			 */
17622 			pass = 12;
17623 			goto send;
17624 		}
17625 	}
17626 	/*
17627 	 * Sending of standalone window updates.
17628 	 *
17629 	 * Window updates are important when we close our window due to a
17630 	 * full socket buffer and are opening it again after the application
17631 	 * reads data from it.  Once the window has opened again and the
17632 	 * remote end starts to send again the ACK clock takes over and
17633 	 * provides the most current window information.
17634 	 *
17635 	 * We must avoid the silly window syndrome whereas every read from
17636 	 * the receive buffer, no matter how small, causes a window update
17637 	 * to be sent.  We also should avoid sending a flurry of window
17638 	 * updates when the socket buffer had queued a lot of data and the
17639 	 * application is doing small reads.
17640 	 *
17641 	 * Prevent a flurry of pointless window updates by only sending an
17642 	 * update when we can increase the advertized window by more than
17643 	 * 1/4th of the socket buffer capacity.  When the buffer is getting
17644 	 * full or is very small be more aggressive and send an update
17645 	 * whenever we can increase by two mss sized segments. In all other
17646 	 * situations the ACK's to new incoming data will carry further
17647 	 * window increases.
17648 	 *
17649 	 * Don't send an independent window update if a delayed ACK is
17650 	 * pending (it will get piggy-backed on it) or the remote side
17651 	 * already has done a half-close and won't send more data.  Skip
17652 	 * this if the connection is in T/TCP half-open state.
17653 	 */
17654 	if (recwin > 0 && !(tp->t_flags & TF_NEEDSYN) &&
17655 	    !(tp->t_flags & TF_DELACK) &&
17656 	    !TCPS_HAVERCVDFIN(tp->t_state)) {
17657 		/*
17658 		 * "adv" is the amount we could increase the window, taking
17659 		 * into account that we are limited by TCP_MAXWIN <<
17660 		 * tp->rcv_scale.
17661 		 */
17662 		int32_t adv;
17663 		int oldwin;
17664 
17665 		adv = recwin;
17666 		if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt)) {
17667 			oldwin = (tp->rcv_adv - tp->rcv_nxt);
17668 			if (adv > oldwin)
17669 			    adv -= oldwin;
17670 			else {
17671 				/* We can't increase the window */
17672 				adv = 0;
17673 			}
17674 		} else
17675 			oldwin = 0;
17676 
17677 		/*
17678 		 * If the new window size ends up being the same as or less
17679 		 * than the old size when it is scaled, then don't force
17680 		 * a window update.
17681 		 */
17682 		if (oldwin >> tp->rcv_scale >= (adv + oldwin) >> tp->rcv_scale)
17683 			goto dontupdate;
17684 
17685 		if (adv >= (int32_t)(2 * segsiz) &&
17686 		    (adv >= (int32_t)(so->so_rcv.sb_hiwat / 4) ||
17687 		     recwin <= (int32_t)(so->so_rcv.sb_hiwat / 8) ||
17688 		     so->so_rcv.sb_hiwat <= 8 * segsiz)) {
17689 			pass = 7;
17690 			goto send;
17691 		}
17692 		if (2 * adv >= (int32_t) so->so_rcv.sb_hiwat) {
17693 			pass = 23;
17694 			goto send;
17695 		}
17696 	}
17697 dontupdate:
17698 
17699 	/*
17700 	 * Send if we owe the peer an ACK, RST, SYN, or urgent data.  ACKNOW
17701 	 * is also a catch-all for the retransmit timer timeout case.
17702 	 */
17703 	if (tp->t_flags & TF_ACKNOW) {
17704 		pass = 8;
17705 		goto send;
17706 	}
17707 	if (((flags & TH_SYN) && (tp->t_flags & TF_NEEDSYN) == 0)) {
17708 		pass = 9;
17709 		goto send;
17710 	}
17711 	/*
17712 	 * If our state indicates that FIN should be sent and we have not
17713 	 * yet done so, then we need to send.
17714 	 */
17715 	if ((flags & TH_FIN) &&
17716 	    (tp->snd_nxt == tp->snd_una)) {
17717 		pass = 11;
17718 		goto send;
17719 	}
17720 	/*
17721 	 * No reason to send a segment, just return.
17722 	 */
17723 just_return:
17724 	SOCKBUF_UNLOCK(sb);
17725 just_return_nolock:
17726 	{
17727 		int app_limited = CTF_JR_SENT_DATA;
17728 
17729 		if (tot_len_this_send > 0) {
17730 			/* Make sure snd_nxt is up to max */
17731 			rack->r_ctl.fsb.recwin = recwin;
17732 			slot = rack_get_pacing_delay(rack, tp, tot_len_this_send, NULL, segsiz);
17733 			if ((error == 0) &&
17734 			    rack_use_rfo &&
17735 			    ((flags & (TH_SYN|TH_FIN)) == 0) &&
17736 			    (ipoptlen == 0) &&
17737 			    (tp->snd_nxt == tp->snd_max) &&
17738 			    (tp->rcv_numsacks == 0) &&
17739 			    rack->r_fsb_inited &&
17740 			    TCPS_HAVEESTABLISHED(tp->t_state) &&
17741 			    (rack->r_must_retran == 0) &&
17742 			    ((tp->t_flags & TF_NEEDFIN) == 0) &&
17743 			    (len > 0) && (orig_len > 0) &&
17744 			    (orig_len > len) &&
17745 			    ((orig_len - len) >= segsiz) &&
17746 			    ((optlen == 0) ||
17747 			     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
17748 				/* We can send at least one more MSS using our fsb */
17749 
17750 				rack->r_fast_output = 1;
17751 				rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
17752 				rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
17753 				rack->r_ctl.fsb.tcp_flags = flags;
17754 				rack->r_ctl.fsb.left_to_send = orig_len - len;
17755 				if (hw_tls)
17756 					rack->r_ctl.fsb.hw_tls = 1;
17757 				else
17758 					rack->r_ctl.fsb.hw_tls = 0;
17759 				KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
17760 					("rack:%p left_to_send:%u sbavail:%u out:%u",
17761 					rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
17762 					 (tp->snd_max - tp->snd_una)));
17763 				if (rack->r_ctl.fsb.left_to_send < segsiz)
17764 					rack->r_fast_output = 0;
17765 				else {
17766 					if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
17767 						rack->r_ctl.fsb.rfo_apply_push = 1;
17768 					else
17769 						rack->r_ctl.fsb.rfo_apply_push = 0;
17770 				}
17771 			} else
17772 				rack->r_fast_output = 0;
17773 
17774 
17775 			rack_log_fsb(rack, tp, so, flags,
17776 				     ipoptlen, orig_len, len, 0,
17777 				     1, optlen, __LINE__, 1);
17778 			if (SEQ_GT(tp->snd_max, tp->snd_nxt))
17779 				tp->snd_nxt = tp->snd_max;
17780 		} else {
17781 			int end_window = 0;
17782 			uint32_t seq = tp->gput_ack;
17783 
17784 			rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
17785 			if (rsm) {
17786 				/*
17787 				 * Mark the last sent that we just-returned (hinting
17788 				 * that delayed ack may play a role in any rtt measurement).
17789 				 */
17790 				rsm->r_just_ret = 1;
17791 			}
17792 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_JUSTRET], 1);
17793 			rack->r_ctl.rc_agg_delayed = 0;
17794 			rack->r_early = 0;
17795 			rack->r_late = 0;
17796 			rack->r_ctl.rc_agg_early = 0;
17797 			if ((ctf_outstanding(tp) +
17798 			     min(max(segsiz, (rack->r_ctl.rc_high_rwnd/2)),
17799 				 minseg)) >= tp->snd_wnd) {
17800 				/* We are limited by the rwnd */
17801 				app_limited = CTF_JR_RWND_LIMITED;
17802 				if (IN_FASTRECOVERY(tp->t_flags))
17803 				    rack->r_ctl.rc_prr_sndcnt = 0;
17804 			} else if (ctf_outstanding(tp) >= sbavail(sb)) {
17805 				/* We are limited by whats available -- app limited */
17806 				app_limited = CTF_JR_APP_LIMITED;
17807 				if (IN_FASTRECOVERY(tp->t_flags))
17808 				    rack->r_ctl.rc_prr_sndcnt = 0;
17809 			} else if ((idle == 0) &&
17810 				   ((tp->t_flags & TF_NODELAY) == 0) &&
17811 				   ((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
17812 				   (len < segsiz)) {
17813 				/*
17814 				 * No delay is not on and the
17815 				 * user is sending less than 1MSS. This
17816 				 * brings out SWS avoidance so we
17817 				 * don't send. Another app-limited case.
17818 				 */
17819 				app_limited = CTF_JR_APP_LIMITED;
17820 			} else if (tp->t_flags & TF_NOPUSH) {
17821 				/*
17822 				 * The user has requested no push of
17823 				 * the last segment and we are
17824 				 * at the last segment. Another app
17825 				 * limited case.
17826 				 */
17827 				app_limited = CTF_JR_APP_LIMITED;
17828 			} else if ((ctf_outstanding(tp) + minseg) > cwnd_to_use) {
17829 				/* Its the cwnd */
17830 				app_limited = CTF_JR_CWND_LIMITED;
17831 			} else if (IN_FASTRECOVERY(tp->t_flags) &&
17832 				   (rack->rack_no_prr == 0) &&
17833 				   (rack->r_ctl.rc_prr_sndcnt < segsiz)) {
17834 				app_limited = CTF_JR_PRR;
17835 			} else {
17836 				/* Now why here are we not sending? */
17837 #ifdef NOW
17838 #ifdef INVARIANTS
17839 				panic("rack:%p hit JR_ASSESSING case cwnd_to_use:%u?", rack, cwnd_to_use);
17840 #endif
17841 #endif
17842 				app_limited = CTF_JR_ASSESSING;
17843 			}
17844 			/*
17845 			 * App limited in some fashion, for our pacing GP
17846 			 * measurements we don't want any gap (even cwnd).
17847 			 * Close  down the measurement window.
17848 			 */
17849 			if (rack_cwnd_block_ends_measure &&
17850 			    ((app_limited == CTF_JR_CWND_LIMITED) ||
17851 			     (app_limited == CTF_JR_PRR))) {
17852 				/*
17853 				 * The reason we are not sending is
17854 				 * the cwnd (or prr). We have been configured
17855 				 * to end the measurement window in
17856 				 * this case.
17857 				 */
17858 				end_window = 1;
17859 			} else if (rack_rwnd_block_ends_measure &&
17860 				   (app_limited == CTF_JR_RWND_LIMITED)) {
17861 				/*
17862 				 * We are rwnd limited and have been
17863 				 * configured to end the measurement
17864 				 * window in this case.
17865 				 */
17866 				end_window = 1;
17867 			} else if (app_limited == CTF_JR_APP_LIMITED) {
17868 				/*
17869 				 * A true application limited period, we have
17870 				 * ran out of data.
17871 				 */
17872 				end_window = 1;
17873 			} else if (app_limited == CTF_JR_ASSESSING) {
17874 				/*
17875 				 * In the assessing case we hit the end of
17876 				 * the if/else and had no known reason
17877 				 * This will panic us under invariants..
17878 				 *
17879 				 * If we get this out in logs we need to
17880 				 * investagate which reason we missed.
17881 				 */
17882 				end_window = 1;
17883 			}
17884 			if (end_window) {
17885 				uint8_t log = 0;
17886 
17887 				/* Adjust the Gput measurement */
17888 				if ((tp->t_flags & TF_GPUTINPROG) &&
17889 				    SEQ_GT(tp->gput_ack, tp->snd_max)) {
17890 					tp->gput_ack = tp->snd_max;
17891 					if ((tp->gput_ack - tp->gput_seq) < (MIN_GP_WIN * segsiz)) {
17892 						/*
17893 						 * There is not enough to measure.
17894 						 */
17895 						tp->t_flags &= ~TF_GPUTINPROG;
17896 						rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
17897 									   rack->r_ctl.rc_gp_srtt /*flex1*/,
17898 									   tp->gput_seq,
17899 									   0, 0, 18, __LINE__, NULL, 0);
17900 					} else
17901 						log = 1;
17902 				}
17903 				/* Mark the last packet has app limited */
17904 				rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
17905 				if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
17906 					if (rack->r_ctl.rc_app_limited_cnt == 0)
17907 						rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
17908 					else {
17909 						/*
17910 						 * Go out to the end app limited and mark
17911 						 * this new one as next and move the end_appl up
17912 						 * to this guy.
17913 						 */
17914 						if (rack->r_ctl.rc_end_appl)
17915 							rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
17916 						rack->r_ctl.rc_end_appl = rsm;
17917 					}
17918 					rsm->r_flags |= RACK_APP_LIMITED;
17919 					rack->r_ctl.rc_app_limited_cnt++;
17920 				}
17921 				if (log)
17922 					rack_log_pacing_delay_calc(rack,
17923 								   rack->r_ctl.rc_app_limited_cnt, seq,
17924 								   tp->gput_ack, 0, 0, 4, __LINE__, NULL, 0);
17925 			}
17926 		}
17927 		/* Check if we need to go into persists or not */
17928 		if ((tp->snd_max == tp->snd_una) &&
17929 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
17930 		    sbavail(sb) &&
17931 		    (sbavail(sb) > tp->snd_wnd) &&
17932 		    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg))) {
17933 			/* Yes lets make sure to move to persist before timer-start */
17934 			rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
17935 		}
17936 		rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, sup_rack);
17937 		rack_log_type_just_return(rack, cts, tot_len_this_send, slot, hpts_calling, app_limited, cwnd_to_use);
17938 	}
17939 #ifdef NETFLIX_SHARED_CWND
17940 	if ((sbavail(sb) == 0) &&
17941 	    rack->r_ctl.rc_scw) {
17942 		tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
17943 		rack->rack_scwnd_is_idle = 1;
17944 	}
17945 #endif
17946 #ifdef TCP_ACCOUNTING
17947 	if (tot_len_this_send > 0) {
17948 		crtsc = get_cyclecount();
17949 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17950 			tp->tcp_cnt_counters[SND_OUT_DATA]++;
17951 		}
17952 		counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], 1);
17953 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17954 			tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
17955 		}
17956 		counter_u64_add(tcp_proc_time[SND_OUT_DATA], (crtsc - ts_val));
17957 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17958 			tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len_this_send + segsiz - 1) / segsiz);
17959 		}
17960 		counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((tot_len_this_send + segsiz - 1) / segsiz));
17961 	} else {
17962 		crtsc = get_cyclecount();
17963 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17964 			tp->tcp_cnt_counters[SND_LIMITED]++;
17965 		}
17966 		counter_u64_add(tcp_cnt_counters[SND_LIMITED], 1);
17967 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17968 			tp->tcp_proc_time[SND_LIMITED] += (crtsc - ts_val);
17969 		}
17970 		counter_u64_add(tcp_proc_time[SND_LIMITED], (crtsc - ts_val));
17971 	}
17972 	sched_unpin();
17973 #endif
17974 	return (0);
17975 
17976 send:
17977 	if (rsm || sack_rxmit)
17978 		counter_u64_add(rack_nfto_resend, 1);
17979 	else
17980 		counter_u64_add(rack_non_fto_send, 1);
17981 	if ((flags & TH_FIN) &&
17982 	    sbavail(sb)) {
17983 		/*
17984 		 * We do not transmit a FIN
17985 		 * with data outstanding. We
17986 		 * need to make it so all data
17987 		 * is acked first.
17988 		 */
17989 		flags &= ~TH_FIN;
17990 	}
17991 	/* Enforce stack imposed max seg size if we have one */
17992 	if (rack->r_ctl.rc_pace_max_segs &&
17993 	    (len > rack->r_ctl.rc_pace_max_segs)) {
17994 		mark = 1;
17995 		len = rack->r_ctl.rc_pace_max_segs;
17996 	}
17997 	SOCKBUF_LOCK_ASSERT(sb);
17998 	if (len > 0) {
17999 		if (len >= segsiz)
18000 			tp->t_flags2 |= TF2_PLPMTU_MAXSEGSNT;
18001 		else
18002 			tp->t_flags2 &= ~TF2_PLPMTU_MAXSEGSNT;
18003 	}
18004 	/*
18005 	 * Before ESTABLISHED, force sending of initial options unless TCP
18006 	 * set not to do any options. NOTE: we assume that the IP/TCP header
18007 	 * plus TCP options always fit in a single mbuf, leaving room for a
18008 	 * maximum link header, i.e. max_linkhdr + sizeof (struct tcpiphdr)
18009 	 * + optlen <= MCLBYTES
18010 	 */
18011 	optlen = 0;
18012 #ifdef INET6
18013 	if (isipv6)
18014 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
18015 	else
18016 #endif
18017 		hdrlen = sizeof(struct tcpiphdr);
18018 
18019 	/*
18020 	 * Compute options for segment. We only have to care about SYN and
18021 	 * established connection segments.  Options for SYN-ACK segments
18022 	 * are handled in TCP syncache.
18023 	 */
18024 	to.to_flags = 0;
18025 	if ((tp->t_flags & TF_NOOPT) == 0) {
18026 		/* Maximum segment size. */
18027 		if (flags & TH_SYN) {
18028 			tp->snd_nxt = tp->iss;
18029 			to.to_mss = tcp_mssopt(&inp->inp_inc);
18030 			if (tp->t_port)
18031 				to.to_mss -= V_tcp_udp_tunneling_overhead;
18032 			to.to_flags |= TOF_MSS;
18033 
18034 			/*
18035 			 * On SYN or SYN|ACK transmits on TFO connections,
18036 			 * only include the TFO option if it is not a
18037 			 * retransmit, as the presence of the TFO option may
18038 			 * have caused the original SYN or SYN|ACK to have
18039 			 * been dropped by a middlebox.
18040 			 */
18041 			if (IS_FASTOPEN(tp->t_flags) &&
18042 			    (tp->t_rxtshift == 0)) {
18043 				if (tp->t_state == TCPS_SYN_RECEIVED) {
18044 					to.to_tfo_len = TCP_FASTOPEN_COOKIE_LEN;
18045 					to.to_tfo_cookie =
18046 						(u_int8_t *)&tp->t_tfo_cookie.server;
18047 					to.to_flags |= TOF_FASTOPEN;
18048 					wanted_cookie = 1;
18049 				} else if (tp->t_state == TCPS_SYN_SENT) {
18050 					to.to_tfo_len =
18051 						tp->t_tfo_client_cookie_len;
18052 					to.to_tfo_cookie =
18053 						tp->t_tfo_cookie.client;
18054 					to.to_flags |= TOF_FASTOPEN;
18055 					wanted_cookie = 1;
18056 					/*
18057 					 * If we wind up having more data to
18058 					 * send with the SYN than can fit in
18059 					 * one segment, don't send any more
18060 					 * until the SYN|ACK comes back from
18061 					 * the other end.
18062 					 */
18063 					sendalot = 0;
18064 				}
18065 			}
18066 		}
18067 		/* Window scaling. */
18068 		if ((flags & TH_SYN) && (tp->t_flags & TF_REQ_SCALE)) {
18069 			to.to_wscale = tp->request_r_scale;
18070 			to.to_flags |= TOF_SCALE;
18071 		}
18072 		/* Timestamps. */
18073 		if ((tp->t_flags & TF_RCVD_TSTMP) ||
18074 		    ((flags & TH_SYN) && (tp->t_flags & TF_REQ_TSTMP))) {
18075 			to.to_tsval = ms_cts + tp->ts_offset;
18076 			to.to_tsecr = tp->ts_recent;
18077 			to.to_flags |= TOF_TS;
18078 		}
18079 		/* Set receive buffer autosizing timestamp. */
18080 		if (tp->rfbuf_ts == 0 &&
18081 		    (so->so_rcv.sb_flags & SB_AUTOSIZE))
18082 			tp->rfbuf_ts = tcp_ts_getticks();
18083 		/* Selective ACK's. */
18084 		if (tp->t_flags & TF_SACK_PERMIT) {
18085 			if (flags & TH_SYN)
18086 				to.to_flags |= TOF_SACKPERM;
18087 			else if (TCPS_HAVEESTABLISHED(tp->t_state) &&
18088 				 tp->rcv_numsacks > 0) {
18089 				to.to_flags |= TOF_SACK;
18090 				to.to_nsacks = tp->rcv_numsacks;
18091 				to.to_sacks = (u_char *)tp->sackblks;
18092 			}
18093 		}
18094 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
18095 		/* TCP-MD5 (RFC2385). */
18096 		if (tp->t_flags & TF_SIGNATURE)
18097 			to.to_flags |= TOF_SIGNATURE;
18098 #endif				/* TCP_SIGNATURE */
18099 
18100 		/* Processing the options. */
18101 		hdrlen += optlen = tcp_addoptions(&to, opt);
18102 		/*
18103 		 * If we wanted a TFO option to be added, but it was unable
18104 		 * to fit, ensure no data is sent.
18105 		 */
18106 		if (IS_FASTOPEN(tp->t_flags) && wanted_cookie &&
18107 		    !(to.to_flags & TOF_FASTOPEN))
18108 			len = 0;
18109 	}
18110 	if (tp->t_port) {
18111 		if (V_tcp_udp_tunneling_port == 0) {
18112 			/* The port was removed?? */
18113 			SOCKBUF_UNLOCK(&so->so_snd);
18114 #ifdef TCP_ACCOUNTING
18115 			crtsc = get_cyclecount();
18116 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18117 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
18118 			}
18119 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
18120 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18121 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
18122 			}
18123 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
18124 			sched_unpin();
18125 #endif
18126 			return (EHOSTUNREACH);
18127 		}
18128 		hdrlen += sizeof(struct udphdr);
18129 	}
18130 #ifdef INET6
18131 	if (isipv6)
18132 		ipoptlen = ip6_optlen(inp);
18133 	else
18134 #endif
18135 		if (inp->inp_options)
18136 			ipoptlen = inp->inp_options->m_len -
18137 				offsetof(struct ipoption, ipopt_list);
18138 		else
18139 			ipoptlen = 0;
18140 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
18141 	ipoptlen += ipsec_optlen;
18142 #endif
18143 
18144 	/*
18145 	 * Adjust data length if insertion of options will bump the packet
18146 	 * length beyond the t_maxseg length. Clear the FIN bit because we
18147 	 * cut off the tail of the segment.
18148 	 */
18149 	if (len + optlen + ipoptlen > tp->t_maxseg) {
18150 		if (tso) {
18151 			uint32_t if_hw_tsomax;
18152 			uint32_t moff;
18153 			int32_t max_len;
18154 
18155 			/* extract TSO information */
18156 			if_hw_tsomax = tp->t_tsomax;
18157 			if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
18158 			if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
18159 			KASSERT(ipoptlen == 0,
18160 				("%s: TSO can't do IP options", __func__));
18161 
18162 			/*
18163 			 * Check if we should limit by maximum payload
18164 			 * length:
18165 			 */
18166 			if (if_hw_tsomax != 0) {
18167 				/* compute maximum TSO length */
18168 				max_len = (if_hw_tsomax - hdrlen -
18169 					   max_linkhdr);
18170 				if (max_len <= 0) {
18171 					len = 0;
18172 				} else if (len > max_len) {
18173 					sendalot = 1;
18174 					len = max_len;
18175 					mark = 2;
18176 				}
18177 			}
18178 			/*
18179 			 * Prevent the last segment from being fractional
18180 			 * unless the send sockbuf can be emptied:
18181 			 */
18182 			max_len = (tp->t_maxseg - optlen);
18183 			if ((sb_offset + len) < sbavail(sb)) {
18184 				moff = len % (u_int)max_len;
18185 				if (moff != 0) {
18186 					mark = 3;
18187 					len -= moff;
18188 				}
18189 			}
18190 			/*
18191 			 * In case there are too many small fragments don't
18192 			 * use TSO:
18193 			 */
18194 			if (len <= segsiz) {
18195 				mark = 4;
18196 				tso = 0;
18197 			}
18198 			/*
18199 			 * Send the FIN in a separate segment after the bulk
18200 			 * sending is done. We don't trust the TSO
18201 			 * implementations to clear the FIN flag on all but
18202 			 * the last segment.
18203 			 */
18204 			if (tp->t_flags & TF_NEEDFIN) {
18205 				sendalot = 4;
18206 			}
18207 		} else {
18208 			mark = 5;
18209 			if (optlen + ipoptlen >= tp->t_maxseg) {
18210 				/*
18211 				 * Since we don't have enough space to put
18212 				 * the IP header chain and the TCP header in
18213 				 * one packet as required by RFC 7112, don't
18214 				 * send it. Also ensure that at least one
18215 				 * byte of the payload can be put into the
18216 				 * TCP segment.
18217 				 */
18218 				SOCKBUF_UNLOCK(&so->so_snd);
18219 				error = EMSGSIZE;
18220 				sack_rxmit = 0;
18221 				goto out;
18222 			}
18223 			len = tp->t_maxseg - optlen - ipoptlen;
18224 			sendalot = 5;
18225 		}
18226 	} else {
18227 		tso = 0;
18228 		mark = 6;
18229 	}
18230 	KASSERT(len + hdrlen + ipoptlen <= IP_MAXPACKET,
18231 		("%s: len > IP_MAXPACKET", __func__));
18232 #ifdef DIAGNOSTIC
18233 #ifdef INET6
18234 	if (max_linkhdr + hdrlen > MCLBYTES)
18235 #else
18236 		if (max_linkhdr + hdrlen > MHLEN)
18237 #endif
18238 			panic("tcphdr too big");
18239 #endif
18240 
18241 	/*
18242 	 * This KASSERT is here to catch edge cases at a well defined place.
18243 	 * Before, those had triggered (random) panic conditions further
18244 	 * down.
18245 	 */
18246 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
18247 	if ((len == 0) &&
18248 	    (flags & TH_FIN) &&
18249 	    (sbused(sb))) {
18250 		/*
18251 		 * We have outstanding data, don't send a fin by itself!.
18252 		 */
18253 		goto just_return;
18254 	}
18255 	/*
18256 	 * Grab a header mbuf, attaching a copy of data to be transmitted,
18257 	 * and initialize the header from the template for sends on this
18258 	 * connection.
18259 	 */
18260 	hw_tls = (sb->sb_flags & SB_TLS_IFNET) != 0;
18261 	if (len) {
18262 		uint32_t max_val;
18263 		uint32_t moff;
18264 
18265 		if (rack->r_ctl.rc_pace_max_segs)
18266 			max_val = rack->r_ctl.rc_pace_max_segs;
18267 		else if (rack->rc_user_set_max_segs)
18268 			max_val = rack->rc_user_set_max_segs * segsiz;
18269 		else
18270 			max_val = len;
18271 		/*
18272 		 * We allow a limit on sending with hptsi.
18273 		 */
18274 		if (len > max_val) {
18275 			mark = 7;
18276 			len = max_val;
18277 		}
18278 #ifdef INET6
18279 		if (MHLEN < hdrlen + max_linkhdr)
18280 			m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
18281 		else
18282 #endif
18283 			m = m_gethdr(M_NOWAIT, MT_DATA);
18284 
18285 		if (m == NULL) {
18286 			SOCKBUF_UNLOCK(sb);
18287 			error = ENOBUFS;
18288 			sack_rxmit = 0;
18289 			goto out;
18290 		}
18291 		m->m_data += max_linkhdr;
18292 		m->m_len = hdrlen;
18293 
18294 		/*
18295 		 * Start the m_copy functions from the closest mbuf to the
18296 		 * sb_offset in the socket buffer chain.
18297 		 */
18298 		mb = sbsndptr_noadv(sb, sb_offset, &moff);
18299 		s_mb = mb;
18300 		s_moff = moff;
18301 		if (len <= MHLEN - hdrlen - max_linkhdr && !hw_tls) {
18302 			m_copydata(mb, moff, (int)len,
18303 				   mtod(m, caddr_t)+hdrlen);
18304 			if (SEQ_LT(tp->snd_nxt, tp->snd_max))
18305 				sbsndptr_adv(sb, mb, len);
18306 			m->m_len += len;
18307 		} else {
18308 			struct sockbuf *msb;
18309 
18310 			if (SEQ_LT(tp->snd_nxt, tp->snd_max))
18311 				msb = NULL;
18312 			else
18313 				msb = sb;
18314 			m->m_next = tcp_m_copym(
18315 				mb, moff, &len,
18316 				if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, msb,
18317 				((rsm == NULL) ? hw_tls : 0)
18318 #ifdef NETFLIX_COPY_ARGS
18319 				, &s_mb, &s_moff
18320 #endif
18321 				);
18322 			if (len <= (tp->t_maxseg - optlen)) {
18323 				/*
18324 				 * Must have ran out of mbufs for the copy
18325 				 * shorten it to no longer need tso. Lets
18326 				 * not put on sendalot since we are low on
18327 				 * mbufs.
18328 				 */
18329 				tso = 0;
18330 			}
18331 			if (m->m_next == NULL) {
18332 				SOCKBUF_UNLOCK(sb);
18333 				(void)m_free(m);
18334 				error = ENOBUFS;
18335 				sack_rxmit = 0;
18336 				goto out;
18337 			}
18338 		}
18339 		if (SEQ_LT(tp->snd_nxt, tp->snd_max) || sack_rxmit) {
18340 			if (rsm && (rsm->r_flags & RACK_TLP)) {
18341 				/*
18342 				 * TLP should not count in retran count, but
18343 				 * in its own bin
18344 				 */
18345 				counter_u64_add(rack_tlp_retran, 1);
18346 				counter_u64_add(rack_tlp_retran_bytes, len);
18347 			} else {
18348 				tp->t_sndrexmitpack++;
18349 				KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
18350 				KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
18351 			}
18352 #ifdef STATS
18353 			stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
18354 						 len);
18355 #endif
18356 		} else {
18357 			KMOD_TCPSTAT_INC(tcps_sndpack);
18358 			KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
18359 #ifdef STATS
18360 			stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
18361 						 len);
18362 #endif
18363 		}
18364 		/*
18365 		 * If we're sending everything we've got, set PUSH. (This
18366 		 * will keep happy those implementations which only give
18367 		 * data to the user when a buffer fills or a PUSH comes in.)
18368 		 */
18369 		if (sb_offset + len == sbused(sb) &&
18370 		    sbused(sb) &&
18371 		    !(flags & TH_SYN)) {
18372 			flags |= TH_PUSH;
18373 			add_flag |= RACK_HAD_PUSH;
18374 		}
18375 
18376 		SOCKBUF_UNLOCK(sb);
18377 	} else {
18378 		SOCKBUF_UNLOCK(sb);
18379 		if (tp->t_flags & TF_ACKNOW)
18380 			KMOD_TCPSTAT_INC(tcps_sndacks);
18381 		else if (flags & (TH_SYN | TH_FIN | TH_RST))
18382 			KMOD_TCPSTAT_INC(tcps_sndctrl);
18383 		else
18384 			KMOD_TCPSTAT_INC(tcps_sndwinup);
18385 
18386 		m = m_gethdr(M_NOWAIT, MT_DATA);
18387 		if (m == NULL) {
18388 			error = ENOBUFS;
18389 			sack_rxmit = 0;
18390 			goto out;
18391 		}
18392 #ifdef INET6
18393 		if (isipv6 && (MHLEN < hdrlen + max_linkhdr) &&
18394 		    MHLEN >= hdrlen) {
18395 			M_ALIGN(m, hdrlen);
18396 		} else
18397 #endif
18398 			m->m_data += max_linkhdr;
18399 		m->m_len = hdrlen;
18400 	}
18401 	SOCKBUF_UNLOCK_ASSERT(sb);
18402 	m->m_pkthdr.rcvif = (struct ifnet *)0;
18403 #ifdef MAC
18404 	mac_inpcb_create_mbuf(inp, m);
18405 #endif
18406 	if ((ipoptlen == 0) && (rack->r_ctl.fsb.tcp_ip_hdr) &&  rack->r_fsb_inited) {
18407 #ifdef INET6
18408 		if (isipv6)
18409 			ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
18410 		else
18411 #endif				/* INET6 */
18412 			ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
18413 		th = rack->r_ctl.fsb.th;
18414 		udp = rack->r_ctl.fsb.udp;
18415 		if (udp) {
18416 #ifdef INET6
18417 			if (isipv6)
18418 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
18419 			else
18420 #endif				/* INET6 */
18421 				ulen = hdrlen + len - sizeof(struct ip);
18422 			udp->uh_ulen = htons(ulen);
18423 		}
18424 	} else {
18425 #ifdef INET6
18426 		if (isipv6) {
18427 			ip6 = mtod(m, struct ip6_hdr *);
18428 			if (tp->t_port) {
18429 				udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
18430 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
18431 				udp->uh_dport = tp->t_port;
18432 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
18433 				udp->uh_ulen = htons(ulen);
18434 				th = (struct tcphdr *)(udp + 1);
18435 			} else
18436 				th = (struct tcphdr *)(ip6 + 1);
18437 			tcpip_fillheaders(inp, tp->t_port, ip6, th);
18438 		} else
18439 #endif				/* INET6 */
18440 		{
18441 			ip = mtod(m, struct ip *);
18442 			if (tp->t_port) {
18443 				udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
18444 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
18445 				udp->uh_dport = tp->t_port;
18446 				ulen = hdrlen + len - sizeof(struct ip);
18447 				udp->uh_ulen = htons(ulen);
18448 				th = (struct tcphdr *)(udp + 1);
18449 			} else
18450 				th = (struct tcphdr *)(ip + 1);
18451 			tcpip_fillheaders(inp, tp->t_port, ip, th);
18452 		}
18453 	}
18454 	/*
18455 	 * Fill in fields, remembering maximum advertised window for use in
18456 	 * delaying messages about window sizes. If resending a FIN, be sure
18457 	 * not to use a new sequence number.
18458 	 */
18459 	if (flags & TH_FIN && tp->t_flags & TF_SENTFIN &&
18460 	    tp->snd_nxt == tp->snd_max)
18461 		tp->snd_nxt--;
18462 	/*
18463 	 * If we are starting a connection, send ECN setup SYN packet. If we
18464 	 * are on a retransmit, we may resend those bits a number of times
18465 	 * as per RFC 3168.
18466 	 */
18467 	if (tp->t_state == TCPS_SYN_SENT && V_tcp_do_ecn) {
18468 		flags |= tcp_ecn_output_syn_sent(tp);
18469 	}
18470 	/* Also handle parallel SYN for ECN */
18471 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
18472 	    (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))) {
18473 		int ect = tcp_ecn_output_established(tp, &flags, len, sack_rxmit);
18474 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
18475 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
18476 			tp->t_flags2 &= ~TF2_ECN_SND_ECE;
18477 #ifdef INET6
18478 		if (isipv6) {
18479 			ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
18480 			ip6->ip6_flow |= htonl(ect << 20);
18481 		}
18482 		else
18483 #endif
18484 		{
18485 			ip->ip_tos &= ~IPTOS_ECN_MASK;
18486 			ip->ip_tos |= ect;
18487 		}
18488 	}
18489 	/*
18490 	 * If we are doing retransmissions, then snd_nxt will not reflect
18491 	 * the first unsent octet.  For ACK only packets, we do not want the
18492 	 * sequence number of the retransmitted packet, we want the sequence
18493 	 * number of the next unsent octet.  So, if there is no data (and no
18494 	 * SYN or FIN), use snd_max instead of snd_nxt when filling in
18495 	 * ti_seq.  But if we are in persist state, snd_max might reflect
18496 	 * one byte beyond the right edge of the window, so use snd_nxt in
18497 	 * that case, since we know we aren't doing a retransmission.
18498 	 * (retransmit and persist are mutually exclusive...)
18499 	 */
18500 	if (sack_rxmit == 0) {
18501 		if (len || (flags & (TH_SYN | TH_FIN))) {
18502 			th->th_seq = htonl(tp->snd_nxt);
18503 			rack_seq = tp->snd_nxt;
18504 		} else {
18505 			th->th_seq = htonl(tp->snd_max);
18506 			rack_seq = tp->snd_max;
18507 		}
18508 	} else {
18509 		th->th_seq = htonl(rsm->r_start);
18510 		rack_seq = rsm->r_start;
18511 	}
18512 	th->th_ack = htonl(tp->rcv_nxt);
18513 	tcp_set_flags(th, flags);
18514 	/*
18515 	 * Calculate receive window.  Don't shrink window, but avoid silly
18516 	 * window syndrome.
18517 	 * If a RST segment is sent, advertise a window of zero.
18518 	 */
18519 	if (flags & TH_RST) {
18520 		recwin = 0;
18521 	} else {
18522 		if (recwin < (long)(so->so_rcv.sb_hiwat / 4) &&
18523 		    recwin < (long)segsiz) {
18524 			recwin = 0;
18525 		}
18526 		if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) &&
18527 		    recwin < (long)(tp->rcv_adv - tp->rcv_nxt))
18528 			recwin = (long)(tp->rcv_adv - tp->rcv_nxt);
18529 	}
18530 
18531 	/*
18532 	 * According to RFC1323 the window field in a SYN (i.e., a <SYN> or
18533 	 * <SYN,ACK>) segment itself is never scaled.  The <SYN,ACK> case is
18534 	 * handled in syncache.
18535 	 */
18536 	if (flags & TH_SYN)
18537 		th->th_win = htons((u_short)
18538 				   (min(sbspace(&so->so_rcv), TCP_MAXWIN)));
18539 	else {
18540 		/* Avoid shrinking window with window scaling. */
18541 		recwin = roundup2(recwin, 1 << tp->rcv_scale);
18542 		th->th_win = htons((u_short)(recwin >> tp->rcv_scale));
18543 	}
18544 	/*
18545 	 * Adjust the RXWIN0SENT flag - indicate that we have advertised a 0
18546 	 * window.  This may cause the remote transmitter to stall.  This
18547 	 * flag tells soreceive() to disable delayed acknowledgements when
18548 	 * draining the buffer.  This can occur if the receiver is
18549 	 * attempting to read more data than can be buffered prior to
18550 	 * transmitting on the connection.
18551 	 */
18552 	if (th->th_win == 0) {
18553 		tp->t_sndzerowin++;
18554 		tp->t_flags |= TF_RXWIN0SENT;
18555 	} else
18556 		tp->t_flags &= ~TF_RXWIN0SENT;
18557 	tp->snd_up = tp->snd_una;	/* drag it along, its deprecated */
18558 	/* Now are we using fsb?, if so copy the template data to the mbuf */
18559 	if ((ipoptlen == 0) && (rack->r_ctl.fsb.tcp_ip_hdr) && rack->r_fsb_inited) {
18560 		uint8_t *cpto;
18561 
18562 		cpto = mtod(m, uint8_t *);
18563 		memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
18564 		/*
18565 		 * We have just copied in:
18566 		 * IP/IP6
18567 		 * <optional udphdr>
18568 		 * tcphdr (no options)
18569 		 *
18570 		 * We need to grab the correct pointers into the mbuf
18571 		 * for both the tcp header, and possibly the udp header (if tunneling).
18572 		 * We do this by using the offset in the copy buffer and adding it
18573 		 * to the mbuf base pointer (cpto).
18574 		 */
18575 #ifdef INET6
18576 		if (isipv6)
18577 			ip6 = mtod(m, struct ip6_hdr *);
18578 		else
18579 #endif				/* INET6 */
18580 			ip = mtod(m, struct ip *);
18581 		th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
18582 		/* If we have a udp header lets set it into the mbuf as well */
18583 		if (udp)
18584 			udp = (struct udphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.udp - rack->r_ctl.fsb.tcp_ip_hdr));
18585 	}
18586 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
18587 	if (to.to_flags & TOF_SIGNATURE) {
18588 		/*
18589 		 * Calculate MD5 signature and put it into the place
18590 		 * determined before.
18591 		 * NOTE: since TCP options buffer doesn't point into
18592 		 * mbuf's data, calculate offset and use it.
18593 		 */
18594 		if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
18595 						       (u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
18596 			/*
18597 			 * Do not send segment if the calculation of MD5
18598 			 * digest has failed.
18599 			 */
18600 			goto out;
18601 		}
18602 	}
18603 #endif
18604 	if (optlen) {
18605 		bcopy(opt, th + 1, optlen);
18606 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
18607 	}
18608 	/*
18609 	 * Put TCP length in extended header, and then checksum extended
18610 	 * header and data.
18611 	 */
18612 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
18613 #ifdef INET6
18614 	if (isipv6) {
18615 		/*
18616 		 * ip6_plen is not need to be filled now, and will be filled
18617 		 * in ip6_output.
18618 		 */
18619 		if (tp->t_port) {
18620 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
18621 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
18622 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
18623 			th->th_sum = htons(0);
18624 			UDPSTAT_INC(udps_opackets);
18625 		} else {
18626 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
18627 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
18628 			th->th_sum = in6_cksum_pseudo(ip6,
18629 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
18630 						      0);
18631 		}
18632 	}
18633 #endif
18634 #if defined(INET6) && defined(INET)
18635 	else
18636 #endif
18637 #ifdef INET
18638 	{
18639 		if (tp->t_port) {
18640 			m->m_pkthdr.csum_flags = CSUM_UDP;
18641 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
18642 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
18643 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
18644 			th->th_sum = htons(0);
18645 			UDPSTAT_INC(udps_opackets);
18646 		} else {
18647 			m->m_pkthdr.csum_flags = CSUM_TCP;
18648 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
18649 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
18650 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
18651 									IPPROTO_TCP + len + optlen));
18652 		}
18653 		/* IP version must be set here for ipv4/ipv6 checking later */
18654 		KASSERT(ip->ip_v == IPVERSION,
18655 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
18656 	}
18657 #endif
18658 	/*
18659 	 * Enable TSO and specify the size of the segments. The TCP pseudo
18660 	 * header checksum is always provided. XXX: Fixme: This is currently
18661 	 * not the case for IPv6.
18662 	 */
18663 	if (tso) {
18664 		KASSERT(len > tp->t_maxseg - optlen,
18665 			("%s: len <= tso_segsz", __func__));
18666 		m->m_pkthdr.csum_flags |= CSUM_TSO;
18667 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
18668 	}
18669 	KASSERT(len + hdrlen == m_length(m, NULL),
18670 		("%s: mbuf chain different than expected: %d + %u != %u",
18671 		 __func__, len, hdrlen, m_length(m, NULL)));
18672 
18673 #ifdef TCP_HHOOK
18674 	/* Run HHOOK_TCP_ESTABLISHED_OUT helper hooks. */
18675 	hhook_run_tcp_est_out(tp, th, &to, len, tso);
18676 #endif
18677 	/* We're getting ready to send; log now. */
18678 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
18679 		union tcp_log_stackspecific log;
18680 
18681 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
18682 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
18683 		if (rack->rack_no_prr)
18684 			log.u_bbr.flex1 = 0;
18685 		else
18686 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
18687 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
18688 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
18689 		log.u_bbr.flex4 = orig_len;
18690 		/* Save off the early/late values */
18691 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
18692 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
18693 		log.u_bbr.bw_inuse = rack_get_bw(rack);
18694 		log.u_bbr.flex8 = 0;
18695 		if (rsm) {
18696 			if (rsm->r_flags & RACK_RWND_COLLAPSED) {
18697 				rack_log_collapse(rack, rsm->r_start, rsm->r_end, 0, __LINE__, 5, rsm->r_flags, rsm);
18698 				counter_u64_add(rack_collapsed_win_rxt, 1);
18699 				counter_u64_add(rack_collapsed_win_rxt_bytes, (rsm->r_end - rsm->r_start));
18700 			}
18701 			if (doing_tlp)
18702 				log.u_bbr.flex8 = 2;
18703 			else
18704 				log.u_bbr.flex8 = 1;
18705 		} else {
18706 			if (doing_tlp)
18707 				log.u_bbr.flex8 = 3;
18708 			else
18709 				log.u_bbr.flex8 = 0;
18710 		}
18711 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
18712 		log.u_bbr.flex7 = mark;
18713 		log.u_bbr.flex7 <<= 8;
18714 		log.u_bbr.flex7 |= pass;
18715 		log.u_bbr.pkts_out = tp->t_maxseg;
18716 		log.u_bbr.timeStamp = cts;
18717 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
18718 		log.u_bbr.lt_epoch = cwnd_to_use;
18719 		log.u_bbr.delivered = sendalot;
18720 		lgb = tcp_log_event_(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_OUT, ERRNO_UNK,
18721 				     len, &log, false, NULL, NULL, 0, &tv);
18722 	} else
18723 		lgb = NULL;
18724 
18725 	/*
18726 	 * Fill in IP length and desired time to live and send to IP level.
18727 	 * There should be a better way to handle ttl and tos; we could keep
18728 	 * them in the template, but need a way to checksum without them.
18729 	 */
18730 	/*
18731 	 * m->m_pkthdr.len should have been set before cksum calcuration,
18732 	 * because in6_cksum() need it.
18733 	 */
18734 #ifdef INET6
18735 	if (isipv6) {
18736 		/*
18737 		 * we separately set hoplimit for every segment, since the
18738 		 * user might want to change the value via setsockopt. Also,
18739 		 * desired default hop limit might be changed via Neighbor
18740 		 * Discovery.
18741 		 */
18742 		rack->r_ctl.fsb.hoplimit = ip6->ip6_hlim = in6_selecthlim(inp, NULL);
18743 
18744 		/*
18745 		 * Set the packet size here for the benefit of DTrace
18746 		 * probes. ip6_output() will set it properly; it's supposed
18747 		 * to include the option header lengths as well.
18748 		 */
18749 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
18750 
18751 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
18752 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
18753 		else
18754 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
18755 
18756 		if (tp->t_state == TCPS_SYN_SENT)
18757 			TCP_PROBE5(connect__request, NULL, tp, ip6, tp, th);
18758 
18759 		TCP_PROBE5(send, NULL, tp, ip6, tp, th);
18760 		/* TODO: IPv6 IP6TOS_ECT bit on */
18761 		error = ip6_output(m,
18762 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
18763 				   inp->in6p_outputopts,
18764 #else
18765 				   NULL,
18766 #endif
18767 				   &inp->inp_route6,
18768 				   ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0),
18769 				   NULL, NULL, inp);
18770 
18771 		if (error == EMSGSIZE && inp->inp_route6.ro_nh != NULL)
18772 			mtu = inp->inp_route6.ro_nh->nh_mtu;
18773 	}
18774 #endif				/* INET6 */
18775 #if defined(INET) && defined(INET6)
18776 	else
18777 #endif
18778 #ifdef INET
18779 	{
18780 		ip->ip_len = htons(m->m_pkthdr.len);
18781 #ifdef INET6
18782 		if (inp->inp_vflag & INP_IPV6PROTO)
18783 			ip->ip_ttl = in6_selecthlim(inp, NULL);
18784 #endif				/* INET6 */
18785 		rack->r_ctl.fsb.hoplimit = ip->ip_ttl;
18786 		/*
18787 		 * If we do path MTU discovery, then we set DF on every
18788 		 * packet. This might not be the best thing to do according
18789 		 * to RFC3390 Section 2. However the tcp hostcache migitates
18790 		 * the problem so it affects only the first tcp connection
18791 		 * with a host.
18792 		 *
18793 		 * NB: Don't set DF on small MTU/MSS to have a safe
18794 		 * fallback.
18795 		 */
18796 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
18797 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
18798 			if (tp->t_port == 0 || len < V_tcp_minmss) {
18799 				ip->ip_off |= htons(IP_DF);
18800 			}
18801 		} else {
18802 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
18803 		}
18804 
18805 		if (tp->t_state == TCPS_SYN_SENT)
18806 			TCP_PROBE5(connect__request, NULL, tp, ip, tp, th);
18807 
18808 		TCP_PROBE5(send, NULL, tp, ip, tp, th);
18809 
18810 		error = ip_output(m,
18811 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
18812 				  inp->inp_options,
18813 #else
18814 				  NULL,
18815 #endif
18816 				  &inp->inp_route,
18817 				  ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0), 0,
18818 				  inp);
18819 		if (error == EMSGSIZE && inp->inp_route.ro_nh != NULL)
18820 			mtu = inp->inp_route.ro_nh->nh_mtu;
18821 	}
18822 #endif				/* INET */
18823 
18824 out:
18825 	if (lgb) {
18826 		lgb->tlb_errno = error;
18827 		lgb = NULL;
18828 	}
18829 	/*
18830 	 * In transmit state, time the transmission and arrange for the
18831 	 * retransmit.  In persist state, just set snd_max.
18832 	 */
18833 	if (error == 0) {
18834 		tcp_account_for_send(tp, len, (rsm != NULL), doing_tlp, hw_tls);
18835 		if (rsm && doing_tlp) {
18836 			rack->rc_last_sent_tlp_past_cumack = 0;
18837 			rack->rc_last_sent_tlp_seq_valid = 1;
18838 			rack->r_ctl.last_sent_tlp_seq = rsm->r_start;
18839 			rack->r_ctl.last_sent_tlp_len = rsm->r_end - rsm->r_start;
18840 		}
18841 		rack->forced_ack = 0;	/* If we send something zap the FA flag */
18842 		if (rsm && (doing_tlp == 0)) {
18843 			/* Set we retransmitted */
18844 			rack->rc_gp_saw_rec = 1;
18845 		} else {
18846 			if (cwnd_to_use > tp->snd_ssthresh) {
18847 				/* Set we sent in CA */
18848 				rack->rc_gp_saw_ca = 1;
18849 			} else {
18850 				/* Set we sent in SS */
18851 				rack->rc_gp_saw_ss = 1;
18852 			}
18853 		}
18854 		if (TCPS_HAVEESTABLISHED(tp->t_state) &&
18855 		    (tp->t_flags & TF_SACK_PERMIT) &&
18856 		    tp->rcv_numsacks > 0)
18857 			tcp_clean_dsack_blocks(tp);
18858 		tot_len_this_send += len;
18859 		if (len == 0)
18860 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_SNDACK], 1);
18861 		else if (len == 1) {
18862 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_PERSIST], 1);
18863 		} else if (len > 1) {
18864 			int idx;
18865 
18866 			idx = (len / segsiz) + 3;
18867 			if (idx >= TCP_MSS_ACCT_ATIMER)
18868 				counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
18869 			else
18870 				counter_u64_add(rack_out_size[idx], 1);
18871 		}
18872 	}
18873 	if ((rack->rack_no_prr == 0) &&
18874 	    sub_from_prr &&
18875 	    (error == 0)) {
18876 		if (rack->r_ctl.rc_prr_sndcnt >= len)
18877 			rack->r_ctl.rc_prr_sndcnt -= len;
18878 		else
18879 			rack->r_ctl.rc_prr_sndcnt = 0;
18880 	}
18881 	sub_from_prr = 0;
18882 	if (doing_tlp) {
18883 		/* Make sure the TLP is added */
18884 		add_flag |= RACK_TLP;
18885 	} else if (rsm) {
18886 		/* If its a resend without TLP then it must not have the flag */
18887 		rsm->r_flags &= ~RACK_TLP;
18888 	}
18889 	rack_log_output(tp, &to, len, rack_seq, (uint8_t) flags, error,
18890 			rack_to_usec_ts(&tv),
18891 			rsm, add_flag, s_mb, s_moff, hw_tls);
18892 
18893 
18894 	if ((error == 0) &&
18895 	    (len > 0) &&
18896 	    (tp->snd_una == tp->snd_max))
18897 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
18898 	{
18899 		tcp_seq startseq = tp->snd_nxt;
18900 
18901 		/* Track our lost count */
18902 		if (rsm && (doing_tlp == 0))
18903 			rack->r_ctl.rc_loss_count += rsm->r_end - rsm->r_start;
18904 		/*
18905 		 * Advance snd_nxt over sequence space of this segment.
18906 		 */
18907 		if (error)
18908 			/* We don't log or do anything with errors */
18909 			goto nomore;
18910 		if (doing_tlp == 0) {
18911 			if (rsm == NULL) {
18912 				/*
18913 				 * Not a retransmission of some
18914 				 * sort, new data is going out so
18915 				 * clear our TLP count and flag.
18916 				 */
18917 				rack->rc_tlp_in_progress = 0;
18918 				rack->r_ctl.rc_tlp_cnt_out = 0;
18919 			}
18920 		} else {
18921 			/*
18922 			 * We have just sent a TLP, mark that it is true
18923 			 * and make sure our in progress is set so we
18924 			 * continue to check the count.
18925 			 */
18926 			rack->rc_tlp_in_progress = 1;
18927 			rack->r_ctl.rc_tlp_cnt_out++;
18928 		}
18929 		if (flags & (TH_SYN | TH_FIN)) {
18930 			if (flags & TH_SYN)
18931 				tp->snd_nxt++;
18932 			if (flags & TH_FIN) {
18933 				tp->snd_nxt++;
18934 				tp->t_flags |= TF_SENTFIN;
18935 			}
18936 		}
18937 		/* In the ENOBUFS case we do *not* update snd_max */
18938 		if (sack_rxmit)
18939 			goto nomore;
18940 
18941 		tp->snd_nxt += len;
18942 		if (SEQ_GT(tp->snd_nxt, tp->snd_max)) {
18943 			if (tp->snd_una == tp->snd_max) {
18944 				/*
18945 				 * Update the time we just added data since
18946 				 * none was outstanding.
18947 				 */
18948 				rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
18949 				tp->t_acktime = ticks;
18950 			}
18951 			tp->snd_max = tp->snd_nxt;
18952 			/*
18953 			 * Time this transmission if not a retransmission and
18954 			 * not currently timing anything.
18955 			 * This is only relevant in case of switching back to
18956 			 * the base stack.
18957 			 */
18958 			if (tp->t_rtttime == 0) {
18959 				tp->t_rtttime = ticks;
18960 				tp->t_rtseq = startseq;
18961 				KMOD_TCPSTAT_INC(tcps_segstimed);
18962 			}
18963 			if (len &&
18964 			    ((tp->t_flags & TF_GPUTINPROG) == 0))
18965 				rack_start_gp_measurement(tp, rack, startseq, sb_offset);
18966 		}
18967 		/*
18968 		 * If we are doing FO we need to update the mbuf position and subtract
18969 		 * this happens when the peer sends us duplicate information and
18970 		 * we thus want to send a DSACK.
18971 		 *
18972 		 * XXXRRS: This brings to mind a ?, when we send a DSACK block is TSO
18973 		 * turned off? If not then we are going to echo multiple DSACK blocks
18974 		 * out (with the TSO), which we should not be doing.
18975 		 */
18976 		if (rack->r_fast_output && len) {
18977 			if (rack->r_ctl.fsb.left_to_send > len)
18978 				rack->r_ctl.fsb.left_to_send -= len;
18979 			else
18980 				rack->r_ctl.fsb.left_to_send = 0;
18981 			if (rack->r_ctl.fsb.left_to_send < segsiz)
18982 				rack->r_fast_output = 0;
18983 			if (rack->r_fast_output) {
18984 				rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
18985 				rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
18986 			}
18987 		}
18988 	}
18989 nomore:
18990 	if (error) {
18991 		rack->r_ctl.rc_agg_delayed = 0;
18992 		rack->r_early = 0;
18993 		rack->r_late = 0;
18994 		rack->r_ctl.rc_agg_early = 0;
18995 		SOCKBUF_UNLOCK_ASSERT(sb);	/* Check gotos. */
18996 		/*
18997 		 * Failures do not advance the seq counter above. For the
18998 		 * case of ENOBUFS we will fall out and retry in 1ms with
18999 		 * the hpts. Everything else will just have to retransmit
19000 		 * with the timer.
19001 		 *
19002 		 * In any case, we do not want to loop around for another
19003 		 * send without a good reason.
19004 		 */
19005 		sendalot = 0;
19006 		switch (error) {
19007 		case EPERM:
19008 			tp->t_softerror = error;
19009 #ifdef TCP_ACCOUNTING
19010 			crtsc = get_cyclecount();
19011 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19012 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
19013 			}
19014 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
19015 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19016 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
19017 			}
19018 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
19019 			sched_unpin();
19020 #endif
19021 			return (error);
19022 		case ENOBUFS:
19023 			/*
19024 			 * Pace us right away to retry in a some
19025 			 * time
19026 			 */
19027 			if (rack->r_ctl.crte != NULL) {
19028 				rack_trace_point(rack, RACK_TP_HWENOBUF);
19029 			} else
19030 				rack_trace_point(rack, RACK_TP_ENOBUF);
19031 			slot = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
19032 			if (rack->rc_enobuf < 0x7f)
19033 				rack->rc_enobuf++;
19034 			if (slot < (10 * HPTS_USEC_IN_MSEC))
19035 				slot = 10 * HPTS_USEC_IN_MSEC;
19036 			if (rack->r_ctl.crte != NULL) {
19037 				counter_u64_add(rack_saw_enobuf_hw, 1);
19038 				tcp_rl_log_enobuf(rack->r_ctl.crte);
19039 			}
19040 			counter_u64_add(rack_saw_enobuf, 1);
19041 			goto enobufs;
19042 		case EMSGSIZE:
19043 			/*
19044 			 * For some reason the interface we used initially
19045 			 * to send segments changed to another or lowered
19046 			 * its MTU. If TSO was active we either got an
19047 			 * interface without TSO capabilits or TSO was
19048 			 * turned off. If we obtained mtu from ip_output()
19049 			 * then update it and try again.
19050 			 */
19051 			if (tso)
19052 				tp->t_flags &= ~TF_TSO;
19053 			if (mtu != 0) {
19054 				tcp_mss_update(tp, -1, mtu, NULL, NULL);
19055 				goto again;
19056 			}
19057 			slot = 10 * HPTS_USEC_IN_MSEC;
19058 			rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
19059 #ifdef TCP_ACCOUNTING
19060 			crtsc = get_cyclecount();
19061 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19062 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
19063 			}
19064 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
19065 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19066 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
19067 			}
19068 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
19069 			sched_unpin();
19070 #endif
19071 			return (error);
19072 		case ENETUNREACH:
19073 			counter_u64_add(rack_saw_enetunreach, 1);
19074 		case EHOSTDOWN:
19075 		case EHOSTUNREACH:
19076 		case ENETDOWN:
19077 			if (TCPS_HAVERCVDSYN(tp->t_state)) {
19078 				tp->t_softerror = error;
19079 			}
19080 			/* FALLTHROUGH */
19081 		default:
19082 			slot = 10 * HPTS_USEC_IN_MSEC;
19083 			rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
19084 #ifdef TCP_ACCOUNTING
19085 			crtsc = get_cyclecount();
19086 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19087 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
19088 			}
19089 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
19090 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19091 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
19092 			}
19093 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
19094 			sched_unpin();
19095 #endif
19096 			return (error);
19097 		}
19098 	} else {
19099 		rack->rc_enobuf = 0;
19100 		if (IN_FASTRECOVERY(tp->t_flags) && rsm)
19101 			rack->r_ctl.retran_during_recovery += len;
19102 	}
19103 	KMOD_TCPSTAT_INC(tcps_sndtotal);
19104 
19105 	/*
19106 	 * Data sent (as far as we can tell). If this advertises a larger
19107 	 * window than any other segment, then remember the size of the
19108 	 * advertised window. Any pending ACK has now been sent.
19109 	 */
19110 	if (recwin > 0 && SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv))
19111 		tp->rcv_adv = tp->rcv_nxt + recwin;
19112 
19113 	tp->last_ack_sent = tp->rcv_nxt;
19114 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
19115 enobufs:
19116 	if (sendalot) {
19117 		/* Do we need to turn off sendalot? */
19118 		if (rack->r_ctl.rc_pace_max_segs &&
19119 		    (tot_len_this_send >= rack->r_ctl.rc_pace_max_segs)) {
19120 			/* We hit our max. */
19121 			sendalot = 0;
19122 		} else if ((rack->rc_user_set_max_segs) &&
19123 			   (tot_len_this_send >= (rack->rc_user_set_max_segs * segsiz))) {
19124 			/* We hit the user defined max */
19125 			sendalot = 0;
19126 		}
19127 	}
19128 	if ((error == 0) && (flags & TH_FIN))
19129 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_FIN);
19130 	if (flags & TH_RST) {
19131 		/*
19132 		 * We don't send again after sending a RST.
19133 		 */
19134 		slot = 0;
19135 		sendalot = 0;
19136 		if (error == 0)
19137 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
19138 	} else if ((slot == 0) && (sendalot == 0) && tot_len_this_send) {
19139 		/*
19140 		 * Get our pacing rate, if an error
19141 		 * occurred in sending (ENOBUF) we would
19142 		 * hit the else if with slot preset. Other
19143 		 * errors return.
19144 		 */
19145 		slot = rack_get_pacing_delay(rack, tp, tot_len_this_send, rsm, segsiz);
19146 	}
19147 	if (rsm &&
19148 	    (rsm->r_flags & RACK_HAS_SYN) == 0 &&
19149 	    rack->use_rack_rr) {
19150 		/* Its a retransmit and we use the rack cheat? */
19151 		if ((slot == 0) ||
19152 		    (rack->rc_always_pace == 0) ||
19153 		    (rack->r_rr_config == 1)) {
19154 			/*
19155 			 * We have no pacing set or we
19156 			 * are using old-style rack or
19157 			 * we are overridden to use the old 1ms pacing.
19158 			 */
19159 			slot = rack->r_ctl.rc_min_to;
19160 		}
19161 	}
19162 	/* We have sent clear the flag */
19163 	rack->r_ent_rec_ns = 0;
19164 	if (rack->r_must_retran) {
19165 		if (rsm) {
19166 			rack->r_ctl.rc_out_at_rto -= (rsm->r_end - rsm->r_start);
19167 			if (SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) {
19168 				/*
19169 				 * We have retransmitted all.
19170 				 */
19171 				rack->r_must_retran = 0;
19172 				rack->r_ctl.rc_out_at_rto = 0;
19173 			}
19174 		} else if (SEQ_GEQ(tp->snd_max, rack->r_ctl.rc_snd_max_at_rto)) {
19175 			/*
19176 			 * Sending new data will also kill
19177 			 * the loop.
19178 			 */
19179 			rack->r_must_retran = 0;
19180 			rack->r_ctl.rc_out_at_rto = 0;
19181 		}
19182 	}
19183 	rack->r_ctl.fsb.recwin = recwin;
19184 	if ((tp->t_flags & (TF_WASCRECOVERY|TF_WASFRECOVERY)) &&
19185 	    SEQ_GT(tp->snd_max, rack->r_ctl.rc_snd_max_at_rto)) {
19186 		/*
19187 		 * We hit an RTO and now have past snd_max at the RTO
19188 		 * clear all the WAS flags.
19189 		 */
19190 		tp->t_flags &= ~(TF_WASCRECOVERY|TF_WASFRECOVERY);
19191 	}
19192 	if (slot) {
19193 		/* set the rack tcb into the slot N */
19194 		if ((error == 0) &&
19195 		    rack_use_rfo &&
19196 		    ((flags & (TH_SYN|TH_FIN)) == 0) &&
19197 		    (rsm == NULL) &&
19198 		    (tp->snd_nxt == tp->snd_max) &&
19199 		    (ipoptlen == 0) &&
19200 		    (tp->rcv_numsacks == 0) &&
19201 		    rack->r_fsb_inited &&
19202 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
19203 		    (rack->r_must_retran == 0) &&
19204 		    ((tp->t_flags & TF_NEEDFIN) == 0) &&
19205 		    (len > 0) && (orig_len > 0) &&
19206 		    (orig_len > len) &&
19207 		    ((orig_len - len) >= segsiz) &&
19208 		    ((optlen == 0) ||
19209 		     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
19210 			/* We can send at least one more MSS using our fsb */
19211 
19212 			rack->r_fast_output = 1;
19213 			rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
19214 			rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
19215 			rack->r_ctl.fsb.tcp_flags = flags;
19216 			rack->r_ctl.fsb.left_to_send = orig_len - len;
19217 			if (hw_tls)
19218 				rack->r_ctl.fsb.hw_tls = 1;
19219 			else
19220 				rack->r_ctl.fsb.hw_tls = 0;
19221 			KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
19222 				("rack:%p left_to_send:%u sbavail:%u out:%u",
19223 				 rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
19224 				 (tp->snd_max - tp->snd_una)));
19225 			if (rack->r_ctl.fsb.left_to_send < segsiz)
19226 				rack->r_fast_output = 0;
19227 			else {
19228 				if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
19229 					rack->r_ctl.fsb.rfo_apply_push = 1;
19230 				else
19231 					rack->r_ctl.fsb.rfo_apply_push = 0;
19232 			}
19233 		} else
19234 			rack->r_fast_output = 0;
19235 		rack_log_fsb(rack, tp, so, flags,
19236 			     ipoptlen, orig_len, len, error,
19237 			     (rsm == NULL), optlen, __LINE__, 2);
19238 	} else if (sendalot) {
19239 		int ret;
19240 
19241 		sack_rxmit = 0;
19242 		if ((error == 0) &&
19243 		    rack_use_rfo &&
19244 		    ((flags & (TH_SYN|TH_FIN)) == 0) &&
19245 		    (rsm == NULL) &&
19246 		    (ipoptlen == 0) &&
19247 		    (tp->rcv_numsacks == 0) &&
19248 		    (tp->snd_nxt == tp->snd_max) &&
19249 		    (rack->r_must_retran == 0) &&
19250 		    rack->r_fsb_inited &&
19251 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
19252 		    ((tp->t_flags & TF_NEEDFIN) == 0) &&
19253 		    (len > 0) && (orig_len > 0) &&
19254 		    (orig_len > len) &&
19255 		    ((orig_len - len) >= segsiz) &&
19256 		    ((optlen == 0) ||
19257 		     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
19258 			/* we can use fast_output for more */
19259 
19260 			rack->r_fast_output = 1;
19261 			rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
19262 			rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
19263 			rack->r_ctl.fsb.tcp_flags = flags;
19264 			rack->r_ctl.fsb.left_to_send = orig_len - len;
19265 			if (hw_tls)
19266 				rack->r_ctl.fsb.hw_tls = 1;
19267 			else
19268 				rack->r_ctl.fsb.hw_tls = 0;
19269 			KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
19270 				("rack:%p left_to_send:%u sbavail:%u out:%u",
19271 				 rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
19272 				 (tp->snd_max - tp->snd_una)));
19273 			if (rack->r_ctl.fsb.left_to_send < segsiz) {
19274 				rack->r_fast_output = 0;
19275 			}
19276 			if (rack->r_fast_output) {
19277 				if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
19278 					rack->r_ctl.fsb.rfo_apply_push = 1;
19279 				else
19280 					rack->r_ctl.fsb.rfo_apply_push = 0;
19281 				rack_log_fsb(rack, tp, so, flags,
19282 					     ipoptlen, orig_len, len, error,
19283 					     (rsm == NULL), optlen, __LINE__, 3);
19284 				error = 0;
19285 				ret = rack_fast_output(tp, rack, ts_val, cts, ms_cts, &tv, tot_len_this_send, &error);
19286 				if (ret >= 0)
19287 					return (ret);
19288 			        else if (error)
19289 					goto nomore;
19290 
19291 			}
19292 		}
19293 		goto again;
19294 	}
19295 	/* Assure when we leave that snd_nxt will point to top */
19296 	if (SEQ_GT(tp->snd_max, tp->snd_nxt))
19297 		tp->snd_nxt = tp->snd_max;
19298 	rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, 0);
19299 #ifdef TCP_ACCOUNTING
19300 	crtsc = get_cyclecount() - ts_val;
19301 	if (tot_len_this_send) {
19302 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19303 			tp->tcp_cnt_counters[SND_OUT_DATA]++;
19304 		}
19305 		counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], 1);
19306 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19307 			tp->tcp_proc_time[SND_OUT_DATA] += crtsc;
19308 		}
19309 		counter_u64_add(tcp_proc_time[SND_OUT_DATA], crtsc);
19310 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19311 			tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len_this_send + segsiz - 1) /segsiz);
19312 		}
19313 		counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((tot_len_this_send + segsiz - 1) /segsiz));
19314 	} else {
19315 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19316 			tp->tcp_cnt_counters[SND_OUT_ACK]++;
19317 		}
19318 		counter_u64_add(tcp_cnt_counters[SND_OUT_ACK], 1);
19319 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19320 			tp->tcp_proc_time[SND_OUT_ACK] += crtsc;
19321 		}
19322 		counter_u64_add(tcp_proc_time[SND_OUT_ACK], crtsc);
19323 	}
19324 	sched_unpin();
19325 #endif
19326 	if (error == ENOBUFS)
19327 		error = 0;
19328 	return (error);
19329 }
19330 
19331 static void
19332 rack_update_seg(struct tcp_rack *rack)
19333 {
19334 	uint32_t orig_val;
19335 
19336 	orig_val = rack->r_ctl.rc_pace_max_segs;
19337 	rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
19338 	if (orig_val != rack->r_ctl.rc_pace_max_segs)
19339 		rack_log_pacing_delay_calc(rack, 0, 0, orig_val, 0, 0, 15, __LINE__, NULL, 0);
19340 }
19341 
19342 static void
19343 rack_mtu_change(struct tcpcb *tp)
19344 {
19345 	/*
19346 	 * The MSS may have changed
19347 	 */
19348 	struct tcp_rack *rack;
19349 	struct rack_sendmap *rsm;
19350 
19351 	rack = (struct tcp_rack *)tp->t_fb_ptr;
19352 	if (rack->r_ctl.rc_pace_min_segs != ctf_fixed_maxseg(tp)) {
19353 		/*
19354 		 * The MTU has changed we need to resend everything
19355 		 * since all we have sent is lost. We first fix
19356 		 * up the mtu though.
19357 		 */
19358 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
19359 		/* We treat this like a full retransmit timeout without the cwnd adjustment */
19360 		rack_remxt_tmr(tp);
19361 		rack->r_fast_output = 0;
19362 		rack->r_ctl.rc_out_at_rto = ctf_flight_size(tp,
19363 						rack->r_ctl.rc_sacked);
19364 		rack->r_ctl.rc_snd_max_at_rto = tp->snd_max;
19365 		rack->r_must_retran = 1;
19366 		/* Mark all inflight to needing to be rxt'd */
19367 		TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
19368 			rsm->r_flags |= RACK_MUST_RXT;
19369 		}
19370 	}
19371 	sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
19372 	/* We don't use snd_nxt to retransmit */
19373 	tp->snd_nxt = tp->snd_max;
19374 }
19375 
19376 static int
19377 rack_set_profile(struct tcp_rack *rack, int prof)
19378 {
19379 	int err = EINVAL;
19380 	if (prof == 1) {
19381 		/* pace_always=1 */
19382 		if (rack->rc_always_pace == 0) {
19383 			if (tcp_can_enable_pacing() == 0)
19384 				return (EBUSY);
19385 		}
19386 		rack->rc_always_pace = 1;
19387 		if (rack->use_fixed_rate || rack->gp_ready)
19388 			rack_set_cc_pacing(rack);
19389 		rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19390 		rack->rack_attempt_hdwr_pace = 0;
19391 		/* cmpack=1 */
19392 		if (rack_use_cmp_acks)
19393 			rack->r_use_cmp_ack = 1;
19394 		if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state) &&
19395 		    rack->r_use_cmp_ack)
19396 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19397 		/* scwnd=1 */
19398 		rack->rack_enable_scwnd = 1;
19399 		/* dynamic=100 */
19400 		rack->rc_gp_dyn_mul = 1;
19401 		/* gp_inc_ca */
19402 		rack->r_ctl.rack_per_of_gp_ca = 100;
19403 		/* rrr_conf=3 */
19404 		rack->r_rr_config = 3;
19405 		/* npush=2 */
19406 		rack->r_ctl.rc_no_push_at_mrtt = 2;
19407 		/* fillcw=1 */
19408 		rack->rc_pace_to_cwnd = 1;
19409 		rack->rc_pace_fill_if_rttin_range = 0;
19410 		rack->rtt_limit_mul = 0;
19411 		/* noprr=1 */
19412 		rack->rack_no_prr = 1;
19413 		/* lscwnd=1 */
19414 		rack->r_limit_scw = 1;
19415 		/* gp_inc_rec */
19416 		rack->r_ctl.rack_per_of_gp_rec = 90;
19417 		err = 0;
19418 
19419 	} else if (prof == 3) {
19420 		/* Same as profile one execept fill_cw becomes 2 (less aggressive set) */
19421 		/* pace_always=1 */
19422 		if (rack->rc_always_pace == 0) {
19423 			if (tcp_can_enable_pacing() == 0)
19424 				return (EBUSY);
19425 		}
19426 		rack->rc_always_pace = 1;
19427 		if (rack->use_fixed_rate || rack->gp_ready)
19428 			rack_set_cc_pacing(rack);
19429 		rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19430 		rack->rack_attempt_hdwr_pace = 0;
19431 		/* cmpack=1 */
19432 		if (rack_use_cmp_acks)
19433 			rack->r_use_cmp_ack = 1;
19434 		if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state) &&
19435 		    rack->r_use_cmp_ack)
19436 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19437 		/* scwnd=1 */
19438 		rack->rack_enable_scwnd = 1;
19439 		/* dynamic=100 */
19440 		rack->rc_gp_dyn_mul = 1;
19441 		/* gp_inc_ca */
19442 		rack->r_ctl.rack_per_of_gp_ca = 100;
19443 		/* rrr_conf=3 */
19444 		rack->r_rr_config = 3;
19445 		/* npush=2 */
19446 		rack->r_ctl.rc_no_push_at_mrtt = 2;
19447 		/* fillcw=2 */
19448 		rack->rc_pace_to_cwnd = 1;
19449 		rack->r_fill_less_agg = 1;
19450 		rack->rc_pace_fill_if_rttin_range = 0;
19451 		rack->rtt_limit_mul = 0;
19452 		/* noprr=1 */
19453 		rack->rack_no_prr = 1;
19454 		/* lscwnd=1 */
19455 		rack->r_limit_scw = 1;
19456 		/* gp_inc_rec */
19457 		rack->r_ctl.rack_per_of_gp_rec = 90;
19458 		err = 0;
19459 
19460 
19461 	} else if (prof == 2) {
19462 		/* cmpack=1 */
19463 		if (rack->rc_always_pace == 0) {
19464 			if (tcp_can_enable_pacing() == 0)
19465 				return (EBUSY);
19466 		}
19467 		rack->rc_always_pace = 1;
19468 		if (rack->use_fixed_rate || rack->gp_ready)
19469 			rack_set_cc_pacing(rack);
19470 		rack->r_use_cmp_ack = 1;
19471 		if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state))
19472 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19473 		/* pace_always=1 */
19474 		rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19475 		/* scwnd=1 */
19476 		rack->rack_enable_scwnd = 1;
19477 		/* dynamic=100 */
19478 		rack->rc_gp_dyn_mul = 1;
19479 		rack->r_ctl.rack_per_of_gp_ca = 100;
19480 		/* rrr_conf=3 */
19481 		rack->r_rr_config = 3;
19482 		/* npush=2 */
19483 		rack->r_ctl.rc_no_push_at_mrtt = 2;
19484 		/* fillcw=1 */
19485 		rack->rc_pace_to_cwnd = 1;
19486 		rack->rc_pace_fill_if_rttin_range = 0;
19487 		rack->rtt_limit_mul = 0;
19488 		/* noprr=1 */
19489 		rack->rack_no_prr = 1;
19490 		/* lscwnd=0 */
19491 		rack->r_limit_scw = 0;
19492 		err = 0;
19493 	} else if (prof == 0) {
19494 		/* This changes things back to the default settings */
19495 		err = 0;
19496 		if (rack->rc_always_pace) {
19497 			tcp_decrement_paced_conn();
19498 			rack_undo_cc_pacing(rack);
19499 			rack->rc_always_pace = 0;
19500 		}
19501 		if (rack_pace_every_seg && tcp_can_enable_pacing()) {
19502 			rack->rc_always_pace = 1;
19503 			if (rack->use_fixed_rate || rack->gp_ready)
19504 				rack_set_cc_pacing(rack);
19505 		} else
19506 			rack->rc_always_pace = 0;
19507 		if (rack_dsack_std_based & 0x1) {
19508 			/* Basically this means all rack timers are at least (srtt + 1/4 srtt) */
19509 			rack->rc_rack_tmr_std_based = 1;
19510 		}
19511 		if (rack_dsack_std_based & 0x2) {
19512 			/* Basically this means  rack timers are extended based on dsack by up to (2 * srtt) */
19513 			rack->rc_rack_use_dsack = 1;
19514 		}
19515 		if (rack_use_cmp_acks)
19516 			rack->r_use_cmp_ack = 1;
19517 		else
19518 			rack->r_use_cmp_ack = 0;
19519 		if (rack_disable_prr)
19520 			rack->rack_no_prr = 1;
19521 		else
19522 			rack->rack_no_prr = 0;
19523 		if (rack_gp_no_rec_chg)
19524 			rack->rc_gp_no_rec_chg = 1;
19525 		else
19526 			rack->rc_gp_no_rec_chg = 0;
19527 		if (rack_enable_mqueue_for_nonpaced || rack->r_use_cmp_ack) {
19528 			rack->r_mbuf_queue = 1;
19529 			if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state))
19530 				rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19531 			rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19532 		} else {
19533 			rack->r_mbuf_queue = 0;
19534 			rack->rc_inp->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
19535 		}
19536 		if (rack_enable_shared_cwnd)
19537 			rack->rack_enable_scwnd = 1;
19538 		else
19539 			rack->rack_enable_scwnd = 0;
19540 		if (rack_do_dyn_mul) {
19541 			/* When dynamic adjustment is on CA needs to start at 100% */
19542 			rack->rc_gp_dyn_mul = 1;
19543 			if (rack_do_dyn_mul >= 100)
19544 				rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
19545 		} else {
19546 			rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
19547 			rack->rc_gp_dyn_mul = 0;
19548 		}
19549 		rack->r_rr_config = 0;
19550 		rack->r_ctl.rc_no_push_at_mrtt = 0;
19551 		rack->rc_pace_to_cwnd = 0;
19552 		rack->rc_pace_fill_if_rttin_range = 0;
19553 		rack->rtt_limit_mul = 0;
19554 
19555 		if (rack_enable_hw_pacing)
19556 			rack->rack_hdw_pace_ena = 1;
19557 		else
19558 			rack->rack_hdw_pace_ena = 0;
19559 		if (rack_disable_prr)
19560 			rack->rack_no_prr = 1;
19561 		else
19562 			rack->rack_no_prr = 0;
19563 		if (rack_limits_scwnd)
19564 			rack->r_limit_scw  = 1;
19565 		else
19566 			rack->r_limit_scw  = 0;
19567 		err = 0;
19568 	}
19569 	return (err);
19570 }
19571 
19572 static int
19573 rack_add_deferred_option(struct tcp_rack *rack, int sopt_name, uint64_t loptval)
19574 {
19575 	struct deferred_opt_list *dol;
19576 
19577 	dol = malloc(sizeof(struct deferred_opt_list),
19578 		     M_TCPFSB, M_NOWAIT|M_ZERO);
19579 	if (dol == NULL) {
19580 		/*
19581 		 * No space yikes -- fail out..
19582 		 */
19583 		return (0);
19584 	}
19585 	dol->optname = sopt_name;
19586 	dol->optval = loptval;
19587 	TAILQ_INSERT_TAIL(&rack->r_ctl.opt_list, dol, next);
19588 	return (1);
19589 }
19590 
19591 static int
19592 rack_process_option(struct tcpcb *tp, struct tcp_rack *rack, int sopt_name,
19593 		    uint32_t optval, uint64_t loptval)
19594 {
19595 	struct epoch_tracker et;
19596 	struct sockopt sopt;
19597 	struct cc_newreno_opts opt;
19598 	struct inpcb *inp = tptoinpcb(tp);
19599 	uint64_t val;
19600 	int error = 0;
19601 	uint16_t ca, ss;
19602 
19603 	switch (sopt_name) {
19604 
19605 	case TCP_RACK_DSACK_OPT:
19606 		RACK_OPTS_INC(tcp_rack_dsack_opt);
19607 		if (optval & 0x1) {
19608 			rack->rc_rack_tmr_std_based = 1;
19609 		} else {
19610 			rack->rc_rack_tmr_std_based = 0;
19611 		}
19612 		if (optval & 0x2) {
19613 			rack->rc_rack_use_dsack = 1;
19614 		} else {
19615 			rack->rc_rack_use_dsack = 0;
19616 		}
19617 		rack_log_dsack_event(rack, 5, __LINE__, 0, 0);
19618 		break;
19619 	case TCP_RACK_PACING_BETA:
19620 		RACK_OPTS_INC(tcp_rack_beta);
19621 		if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0) {
19622 			/* This only works for newreno. */
19623 			error = EINVAL;
19624 			break;
19625 		}
19626 		if (rack->rc_pacing_cc_set) {
19627 			/*
19628 			 * Set them into the real CC module
19629 			 * whats in the rack pcb is the old values
19630 			 * to be used on restoral/
19631 			 */
19632 			sopt.sopt_dir = SOPT_SET;
19633 			opt.name = CC_NEWRENO_BETA;
19634 			opt.val = optval;
19635 			if (CC_ALGO(tp)->ctl_output != NULL)
19636 				error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
19637 			else {
19638 				error = ENOENT;
19639 				break;
19640 			}
19641 		} else {
19642 			/*
19643 			 * Not pacing yet so set it into our local
19644 			 * rack pcb storage.
19645 			 */
19646 			rack->r_ctl.rc_saved_beta.beta = optval;
19647 		}
19648 		break;
19649 	case TCP_RACK_TIMER_SLOP:
19650 		RACK_OPTS_INC(tcp_rack_timer_slop);
19651 		rack->r_ctl.timer_slop = optval;
19652 		if (rack->rc_tp->t_srtt) {
19653 			/*
19654 			 * If we have an SRTT lets update t_rxtcur
19655 			 * to have the new slop.
19656 			 */
19657 			RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
19658 					   rack_rto_min, rack_rto_max,
19659 					   rack->r_ctl.timer_slop);
19660 		}
19661 		break;
19662 	case TCP_RACK_PACING_BETA_ECN:
19663 		RACK_OPTS_INC(tcp_rack_beta_ecn);
19664 		if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0) {
19665 			/* This only works for newreno. */
19666 			error = EINVAL;
19667 			break;
19668 		}
19669 		if (rack->rc_pacing_cc_set) {
19670 			/*
19671 			 * Set them into the real CC module
19672 			 * whats in the rack pcb is the old values
19673 			 * to be used on restoral/
19674 			 */
19675 			sopt.sopt_dir = SOPT_SET;
19676 			opt.name = CC_NEWRENO_BETA_ECN;
19677 			opt.val = optval;
19678 			if (CC_ALGO(tp)->ctl_output != NULL)
19679 				error = CC_ALGO(tp)->ctl_output(&tp->t_ccv, &sopt, &opt);
19680 			else
19681 				error = ENOENT;
19682 		} else {
19683 			/*
19684 			 * Not pacing yet so set it into our local
19685 			 * rack pcb storage.
19686 			 */
19687 			rack->r_ctl.rc_saved_beta.beta_ecn = optval;
19688 			rack->r_ctl.rc_saved_beta.newreno_flags = CC_NEWRENO_BETA_ECN_ENABLED;
19689 		}
19690 		break;
19691 	case TCP_DEFER_OPTIONS:
19692 		RACK_OPTS_INC(tcp_defer_opt);
19693 		if (optval) {
19694 			if (rack->gp_ready) {
19695 				/* Too late */
19696 				error = EINVAL;
19697 				break;
19698 			}
19699 			rack->defer_options = 1;
19700 		} else
19701 			rack->defer_options = 0;
19702 		break;
19703 	case TCP_RACK_MEASURE_CNT:
19704 		RACK_OPTS_INC(tcp_rack_measure_cnt);
19705 		if (optval && (optval <= 0xff)) {
19706 			rack->r_ctl.req_measurements = optval;
19707 		} else
19708 			error = EINVAL;
19709 		break;
19710 	case TCP_REC_ABC_VAL:
19711 		RACK_OPTS_INC(tcp_rec_abc_val);
19712 		if (optval > 0)
19713 			rack->r_use_labc_for_rec = 1;
19714 		else
19715 			rack->r_use_labc_for_rec = 0;
19716 		break;
19717 	case TCP_RACK_ABC_VAL:
19718 		RACK_OPTS_INC(tcp_rack_abc_val);
19719 		if ((optval > 0) && (optval < 255))
19720 			rack->rc_labc = optval;
19721 		else
19722 			error = EINVAL;
19723 		break;
19724 	case TCP_HDWR_UP_ONLY:
19725 		RACK_OPTS_INC(tcp_pacing_up_only);
19726 		if (optval)
19727 			rack->r_up_only = 1;
19728 		else
19729 			rack->r_up_only = 0;
19730 		break;
19731 	case TCP_PACING_RATE_CAP:
19732 		RACK_OPTS_INC(tcp_pacing_rate_cap);
19733 		rack->r_ctl.bw_rate_cap = loptval;
19734 		break;
19735 	case TCP_RACK_PROFILE:
19736 		RACK_OPTS_INC(tcp_profile);
19737 		error = rack_set_profile(rack, optval);
19738 		break;
19739 	case TCP_USE_CMP_ACKS:
19740 		RACK_OPTS_INC(tcp_use_cmp_acks);
19741 		if ((optval == 0) && (rack->rc_inp->inp_flags2 & INP_MBUF_ACKCMP)) {
19742 			/* You can't turn it off once its on! */
19743 			error = EINVAL;
19744 		} else if ((optval == 1) && (rack->r_use_cmp_ack == 0)) {
19745 			rack->r_use_cmp_ack = 1;
19746 			rack->r_mbuf_queue = 1;
19747 			inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19748 		}
19749 		if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
19750 			inp->inp_flags2 |= INP_MBUF_ACKCMP;
19751 		break;
19752 	case TCP_SHARED_CWND_TIME_LIMIT:
19753 		RACK_OPTS_INC(tcp_lscwnd);
19754 		if (optval)
19755 			rack->r_limit_scw = 1;
19756 		else
19757 			rack->r_limit_scw = 0;
19758 		break;
19759  	case TCP_RACK_PACE_TO_FILL:
19760 		RACK_OPTS_INC(tcp_fillcw);
19761 		if (optval == 0)
19762 			rack->rc_pace_to_cwnd = 0;
19763 		else {
19764 			rack->rc_pace_to_cwnd = 1;
19765 			if (optval > 1)
19766 				rack->r_fill_less_agg = 1;
19767 		}
19768 		if ((optval >= rack_gp_rtt_maxmul) &&
19769 		    rack_gp_rtt_maxmul &&
19770 		    (optval < 0xf)) {
19771 			rack->rc_pace_fill_if_rttin_range = 1;
19772 			rack->rtt_limit_mul = optval;
19773 		} else {
19774 			rack->rc_pace_fill_if_rttin_range = 0;
19775 			rack->rtt_limit_mul = 0;
19776 		}
19777 		break;
19778 	case TCP_RACK_NO_PUSH_AT_MAX:
19779 		RACK_OPTS_INC(tcp_npush);
19780 		if (optval == 0)
19781 			rack->r_ctl.rc_no_push_at_mrtt = 0;
19782 		else if (optval < 0xff)
19783 			rack->r_ctl.rc_no_push_at_mrtt = optval;
19784 		else
19785 			error = EINVAL;
19786 		break;
19787 	case TCP_SHARED_CWND_ENABLE:
19788 		RACK_OPTS_INC(tcp_rack_scwnd);
19789 		if (optval == 0)
19790 			rack->rack_enable_scwnd = 0;
19791 		else
19792 			rack->rack_enable_scwnd = 1;
19793 		break;
19794 	case TCP_RACK_MBUF_QUEUE:
19795 		/* Now do we use the LRO mbuf-queue feature */
19796 		RACK_OPTS_INC(tcp_rack_mbufq);
19797 		if (optval || rack->r_use_cmp_ack)
19798 			rack->r_mbuf_queue = 1;
19799 		else
19800 			rack->r_mbuf_queue = 0;
19801 		if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
19802 			inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19803 		else
19804 			inp->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
19805 		break;
19806 	case TCP_RACK_NONRXT_CFG_RATE:
19807 		RACK_OPTS_INC(tcp_rack_cfg_rate);
19808 		if (optval == 0)
19809 			rack->rack_rec_nonrxt_use_cr = 0;
19810 		else
19811 			rack->rack_rec_nonrxt_use_cr = 1;
19812 		break;
19813 	case TCP_NO_PRR:
19814 		RACK_OPTS_INC(tcp_rack_noprr);
19815 		if (optval == 0)
19816 			rack->rack_no_prr = 0;
19817 		else if (optval == 1)
19818 			rack->rack_no_prr = 1;
19819 		else if (optval == 2)
19820 			rack->no_prr_addback = 1;
19821 		else
19822 			error = EINVAL;
19823 		break;
19824 	case TCP_TIMELY_DYN_ADJ:
19825 		RACK_OPTS_INC(tcp_timely_dyn);
19826 		if (optval == 0)
19827 			rack->rc_gp_dyn_mul = 0;
19828 		else {
19829 			rack->rc_gp_dyn_mul = 1;
19830 			if (optval >= 100) {
19831 				/*
19832 				 * If the user sets something 100 or more
19833 				 * its the gp_ca value.
19834 				 */
19835 				rack->r_ctl.rack_per_of_gp_ca  = optval;
19836 			}
19837 		}
19838 		break;
19839 	case TCP_RACK_DO_DETECTION:
19840 		RACK_OPTS_INC(tcp_rack_do_detection);
19841 		if (optval == 0)
19842 			rack->do_detection = 0;
19843 		else
19844 			rack->do_detection = 1;
19845 		break;
19846 	case TCP_RACK_TLP_USE:
19847 		if ((optval < TLP_USE_ID) || (optval > TLP_USE_TWO_TWO)) {
19848 			error = EINVAL;
19849 			break;
19850 		}
19851 		RACK_OPTS_INC(tcp_tlp_use);
19852 		rack->rack_tlp_threshold_use = optval;
19853 		break;
19854 	case TCP_RACK_TLP_REDUCE:
19855 		/* RACK TLP cwnd reduction (bool) */
19856 		RACK_OPTS_INC(tcp_rack_tlp_reduce);
19857 		rack->r_ctl.rc_tlp_cwnd_reduce = optval;
19858 		break;
19859 	/*  Pacing related ones */
19860 	case TCP_RACK_PACE_ALWAYS:
19861 		/*
19862 		 * zero is old rack method, 1 is new
19863 		 * method using a pacing rate.
19864 		 */
19865 		RACK_OPTS_INC(tcp_rack_pace_always);
19866 		if (optval > 0) {
19867 			if (rack->rc_always_pace) {
19868 				error = EALREADY;
19869 				break;
19870 			} else if (tcp_can_enable_pacing()) {
19871 				rack->rc_always_pace = 1;
19872 				if (rack->use_fixed_rate || rack->gp_ready)
19873 					rack_set_cc_pacing(rack);
19874 			}
19875 			else {
19876 				error = ENOSPC;
19877 				break;
19878 			}
19879 		} else {
19880 			if (rack->rc_always_pace) {
19881 				tcp_decrement_paced_conn();
19882 				rack->rc_always_pace = 0;
19883 				rack_undo_cc_pacing(rack);
19884 			}
19885 		}
19886 		if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
19887 			inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19888 		else
19889 			inp->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
19890 		/* A rate may be set irate or other, if so set seg size */
19891 		rack_update_seg(rack);
19892 		break;
19893 	case TCP_BBR_RACK_INIT_RATE:
19894 		RACK_OPTS_INC(tcp_initial_rate);
19895 		val = optval;
19896 		/* Change from kbits per second to bytes per second */
19897 		val *= 1000;
19898 		val /= 8;
19899 		rack->r_ctl.init_rate = val;
19900 		if (rack->rc_init_win != rack_default_init_window) {
19901 			uint32_t win, snt;
19902 
19903 			/*
19904 			 * Options don't always get applied
19905 			 * in the order you think. So in order
19906 			 * to assure we update a cwnd we need
19907 			 * to check and see if we are still
19908 			 * where we should raise the cwnd.
19909 			 */
19910 			win = rc_init_window(rack);
19911 			if (SEQ_GT(tp->snd_max, tp->iss))
19912 				snt = tp->snd_max - tp->iss;
19913 			else
19914 				snt = 0;
19915 			if ((snt < win) &&
19916 			    (tp->snd_cwnd < win))
19917 				tp->snd_cwnd = win;
19918 		}
19919 		if (rack->rc_always_pace)
19920 			rack_update_seg(rack);
19921 		break;
19922 	case TCP_BBR_IWINTSO:
19923 		RACK_OPTS_INC(tcp_initial_win);
19924 		if (optval && (optval <= 0xff)) {
19925 			uint32_t win, snt;
19926 
19927 			rack->rc_init_win = optval;
19928 			win = rc_init_window(rack);
19929 			if (SEQ_GT(tp->snd_max, tp->iss))
19930 				snt = tp->snd_max - tp->iss;
19931 			else
19932 				snt = 0;
19933 			if ((snt < win) &&
19934 			    (tp->t_srtt |
19935 #ifdef NETFLIX_PEAKRATE
19936 			     tp->t_maxpeakrate |
19937 #endif
19938 			     rack->r_ctl.init_rate)) {
19939 				/*
19940 				 * We are not past the initial window
19941 				 * and we have some bases for pacing,
19942 				 * so we need to possibly adjust up
19943 				 * the cwnd. Note even if we don't set
19944 				 * the cwnd, its still ok to raise the rc_init_win
19945 				 * which can be used coming out of idle when we
19946 				 * would have a rate.
19947 				 */
19948 				if (tp->snd_cwnd < win)
19949 					tp->snd_cwnd = win;
19950 			}
19951 			if (rack->rc_always_pace)
19952 				rack_update_seg(rack);
19953 		} else
19954 			error = EINVAL;
19955 		break;
19956 	case TCP_RACK_FORCE_MSEG:
19957 		RACK_OPTS_INC(tcp_rack_force_max_seg);
19958 		if (optval)
19959 			rack->rc_force_max_seg = 1;
19960 		else
19961 			rack->rc_force_max_seg = 0;
19962 		break;
19963 	case TCP_RACK_PACE_MAX_SEG:
19964 		/* Max segments size in a pace in bytes */
19965 		RACK_OPTS_INC(tcp_rack_max_seg);
19966 		rack->rc_user_set_max_segs = optval;
19967 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
19968 		break;
19969 	case TCP_RACK_PACE_RATE_REC:
19970 		/* Set the fixed pacing rate in Bytes per second ca */
19971 		RACK_OPTS_INC(tcp_rack_pace_rate_rec);
19972 		rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
19973 		if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
19974 			rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
19975 		if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
19976 			rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
19977 		rack->use_fixed_rate = 1;
19978 		if (rack->rc_always_pace)
19979 			rack_set_cc_pacing(rack);
19980 		rack_log_pacing_delay_calc(rack,
19981 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
19982 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
19983 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
19984 					   __LINE__, NULL,0);
19985 		break;
19986 
19987 	case TCP_RACK_PACE_RATE_SS:
19988 		/* Set the fixed pacing rate in Bytes per second ca */
19989 		RACK_OPTS_INC(tcp_rack_pace_rate_ss);
19990 		rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
19991 		if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
19992 			rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
19993 		if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
19994 			rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
19995 		rack->use_fixed_rate = 1;
19996 		if (rack->rc_always_pace)
19997 			rack_set_cc_pacing(rack);
19998 		rack_log_pacing_delay_calc(rack,
19999 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
20000 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
20001 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
20002 					   __LINE__, NULL, 0);
20003 		break;
20004 
20005 	case TCP_RACK_PACE_RATE_CA:
20006 		/* Set the fixed pacing rate in Bytes per second ca */
20007 		RACK_OPTS_INC(tcp_rack_pace_rate_ca);
20008 		rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
20009 		if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
20010 			rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
20011 		if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
20012 			rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
20013 		rack->use_fixed_rate = 1;
20014 		if (rack->rc_always_pace)
20015 			rack_set_cc_pacing(rack);
20016 		rack_log_pacing_delay_calc(rack,
20017 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
20018 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
20019 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
20020 					   __LINE__, NULL, 0);
20021 		break;
20022 	case TCP_RACK_GP_INCREASE_REC:
20023 		RACK_OPTS_INC(tcp_gp_inc_rec);
20024 		rack->r_ctl.rack_per_of_gp_rec = optval;
20025 		rack_log_pacing_delay_calc(rack,
20026 					   rack->r_ctl.rack_per_of_gp_ss,
20027 					   rack->r_ctl.rack_per_of_gp_ca,
20028 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
20029 					   __LINE__, NULL, 0);
20030 		break;
20031 	case TCP_RACK_GP_INCREASE_CA:
20032 		RACK_OPTS_INC(tcp_gp_inc_ca);
20033 		ca = optval;
20034 		if (ca < 100) {
20035 			/*
20036 			 * We don't allow any reduction
20037 			 * over the GP b/w.
20038 			 */
20039 			error = EINVAL;
20040 			break;
20041 		}
20042 		rack->r_ctl.rack_per_of_gp_ca = ca;
20043 		rack_log_pacing_delay_calc(rack,
20044 					   rack->r_ctl.rack_per_of_gp_ss,
20045 					   rack->r_ctl.rack_per_of_gp_ca,
20046 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
20047 					   __LINE__, NULL, 0);
20048 		break;
20049 	case TCP_RACK_GP_INCREASE_SS:
20050 		RACK_OPTS_INC(tcp_gp_inc_ss);
20051 		ss = optval;
20052 		if (ss < 100) {
20053 			/*
20054 			 * We don't allow any reduction
20055 			 * over the GP b/w.
20056 			 */
20057 			error = EINVAL;
20058 			break;
20059 		}
20060 		rack->r_ctl.rack_per_of_gp_ss = ss;
20061 		rack_log_pacing_delay_calc(rack,
20062 					   rack->r_ctl.rack_per_of_gp_ss,
20063 					   rack->r_ctl.rack_per_of_gp_ca,
20064 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
20065 					   __LINE__, NULL, 0);
20066 		break;
20067 	case TCP_RACK_RR_CONF:
20068 		RACK_OPTS_INC(tcp_rack_rrr_no_conf_rate);
20069 		if (optval && optval <= 3)
20070 			rack->r_rr_config = optval;
20071 		else
20072 			rack->r_rr_config = 0;
20073 		break;
20074 	case TCP_HDWR_RATE_CAP:
20075 		RACK_OPTS_INC(tcp_hdwr_rate_cap);
20076 		if (optval) {
20077 			if (rack->r_rack_hw_rate_caps == 0)
20078 				rack->r_rack_hw_rate_caps = 1;
20079 			else
20080 				error = EALREADY;
20081 		} else {
20082 			rack->r_rack_hw_rate_caps = 0;
20083 		}
20084 		break;
20085 	case TCP_BBR_HDWR_PACE:
20086 		RACK_OPTS_INC(tcp_hdwr_pacing);
20087 		if (optval){
20088 			if (rack->rack_hdrw_pacing == 0) {
20089 				rack->rack_hdw_pace_ena = 1;
20090 				rack->rack_attempt_hdwr_pace = 0;
20091 			} else
20092 				error = EALREADY;
20093 		} else {
20094 			rack->rack_hdw_pace_ena = 0;
20095 #ifdef RATELIMIT
20096 			if (rack->r_ctl.crte != NULL) {
20097 				rack->rack_hdrw_pacing = 0;
20098 				rack->rack_attempt_hdwr_pace = 0;
20099 				tcp_rel_pacing_rate(rack->r_ctl.crte, tp);
20100 				rack->r_ctl.crte = NULL;
20101 			}
20102 #endif
20103 		}
20104 		break;
20105 	/*  End Pacing related ones */
20106 	case TCP_RACK_PRR_SENDALOT:
20107 		/* Allow PRR to send more than one seg */
20108 		RACK_OPTS_INC(tcp_rack_prr_sendalot);
20109 		rack->r_ctl.rc_prr_sendalot = optval;
20110 		break;
20111 	case TCP_RACK_MIN_TO:
20112 		/* Minimum time between rack t-o's in ms */
20113 		RACK_OPTS_INC(tcp_rack_min_to);
20114 		rack->r_ctl.rc_min_to = optval;
20115 		break;
20116 	case TCP_RACK_EARLY_SEG:
20117 		/* If early recovery max segments */
20118 		RACK_OPTS_INC(tcp_rack_early_seg);
20119 		rack->r_ctl.rc_early_recovery_segs = optval;
20120 		break;
20121 	case TCP_RACK_ENABLE_HYSTART:
20122 	{
20123 		if (optval) {
20124 			tp->t_ccv.flags |= CCF_HYSTART_ALLOWED;
20125 			if (rack_do_hystart > RACK_HYSTART_ON)
20126 				tp->t_ccv.flags |= CCF_HYSTART_CAN_SH_CWND;
20127 			if (rack_do_hystart > RACK_HYSTART_ON_W_SC)
20128 				tp->t_ccv.flags |= CCF_HYSTART_CONS_SSTH;
20129 		} else {
20130 			tp->t_ccv.flags &= ~(CCF_HYSTART_ALLOWED|CCF_HYSTART_CAN_SH_CWND|CCF_HYSTART_CONS_SSTH);
20131 		}
20132 	}
20133 	break;
20134 	case TCP_RACK_REORD_THRESH:
20135 		/* RACK reorder threshold (shift amount) */
20136 		RACK_OPTS_INC(tcp_rack_reord_thresh);
20137 		if ((optval > 0) && (optval < 31))
20138 			rack->r_ctl.rc_reorder_shift = optval;
20139 		else
20140 			error = EINVAL;
20141 		break;
20142 	case TCP_RACK_REORD_FADE:
20143 		/* Does reordering fade after ms time */
20144 		RACK_OPTS_INC(tcp_rack_reord_fade);
20145 		rack->r_ctl.rc_reorder_fade = optval;
20146 		break;
20147 	case TCP_RACK_TLP_THRESH:
20148 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
20149 		RACK_OPTS_INC(tcp_rack_tlp_thresh);
20150 		if (optval)
20151 			rack->r_ctl.rc_tlp_threshold = optval;
20152 		else
20153 			error = EINVAL;
20154 		break;
20155 	case TCP_BBR_USE_RACK_RR:
20156 		RACK_OPTS_INC(tcp_rack_rr);
20157 		if (optval)
20158 			rack->use_rack_rr = 1;
20159 		else
20160 			rack->use_rack_rr = 0;
20161 		break;
20162 	case TCP_FAST_RSM_HACK:
20163 		RACK_OPTS_INC(tcp_rack_fastrsm_hack);
20164 		if (optval)
20165 			rack->fast_rsm_hack = 1;
20166 		else
20167 			rack->fast_rsm_hack = 0;
20168 		break;
20169 	case TCP_RACK_PKT_DELAY:
20170 		/* RACK added ms i.e. rack-rtt + reord + N */
20171 		RACK_OPTS_INC(tcp_rack_pkt_delay);
20172 		rack->r_ctl.rc_pkt_delay = optval;
20173 		break;
20174 	case TCP_DELACK:
20175 		RACK_OPTS_INC(tcp_rack_delayed_ack);
20176 		if (optval == 0)
20177 			tp->t_delayed_ack = 0;
20178 		else
20179 			tp->t_delayed_ack = 1;
20180 		if (tp->t_flags & TF_DELACK) {
20181 			tp->t_flags &= ~TF_DELACK;
20182 			tp->t_flags |= TF_ACKNOW;
20183 			NET_EPOCH_ENTER(et);
20184 			rack_output(tp);
20185 			NET_EPOCH_EXIT(et);
20186 		}
20187 		break;
20188 
20189 	case TCP_BBR_RACK_RTT_USE:
20190 		RACK_OPTS_INC(tcp_rack_rtt_use);
20191 		if ((optval != USE_RTT_HIGH) &&
20192 		    (optval != USE_RTT_LOW) &&
20193 		    (optval != USE_RTT_AVG))
20194 			error = EINVAL;
20195 		else
20196 			rack->r_ctl.rc_rate_sample_method = optval;
20197 		break;
20198 	case TCP_DATA_AFTER_CLOSE:
20199 		RACK_OPTS_INC(tcp_data_after_close);
20200 		if (optval)
20201 			rack->rc_allow_data_af_clo = 1;
20202 		else
20203 			rack->rc_allow_data_af_clo = 0;
20204 		break;
20205 	default:
20206 		break;
20207 	}
20208 #ifdef NETFLIX_STATS
20209 	tcp_log_socket_option(tp, sopt_name, optval, error);
20210 #endif
20211 	return (error);
20212 }
20213 
20214 
20215 static void
20216 rack_apply_deferred_options(struct tcp_rack *rack)
20217 {
20218 	struct deferred_opt_list *dol, *sdol;
20219 	uint32_t s_optval;
20220 
20221 	TAILQ_FOREACH_SAFE(dol, &rack->r_ctl.opt_list, next, sdol) {
20222 		TAILQ_REMOVE(&rack->r_ctl.opt_list, dol, next);
20223 		/* Disadvantage of deferal is you loose the error return */
20224 		s_optval = (uint32_t)dol->optval;
20225 		(void)rack_process_option(rack->rc_tp, rack, dol->optname, s_optval, dol->optval);
20226 		free(dol, M_TCPDO);
20227 	}
20228 }
20229 
20230 static void
20231 rack_hw_tls_change(struct tcpcb *tp, int chg)
20232 {
20233 	/*
20234 	 * HW tls state has changed.. fix all
20235 	 * rsm's in flight.
20236 	 */
20237 	struct tcp_rack *rack;
20238 	struct rack_sendmap *rsm;
20239 
20240 	rack = (struct tcp_rack *)tp->t_fb_ptr;
20241 	RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
20242 		if (chg)
20243 			rsm->r_hw_tls = 1;
20244 		else
20245 			rsm->r_hw_tls = 0;
20246 	}
20247 	if (chg)
20248 		rack->r_ctl.fsb.hw_tls = 1;
20249 	else
20250 		rack->r_ctl.fsb.hw_tls = 0;
20251 }
20252 
20253 static int
20254 rack_pru_options(struct tcpcb *tp, int flags)
20255 {
20256 	if (flags & PRUS_OOB)
20257 		return (EOPNOTSUPP);
20258 	return (0);
20259 }
20260 
20261 static struct tcp_function_block __tcp_rack = {
20262 	.tfb_tcp_block_name = __XSTRING(STACKNAME),
20263 	.tfb_tcp_output = rack_output,
20264 	.tfb_do_queued_segments = ctf_do_queued_segments,
20265 	.tfb_do_segment_nounlock = rack_do_segment_nounlock,
20266 	.tfb_tcp_do_segment = rack_do_segment,
20267 	.tfb_tcp_ctloutput = rack_ctloutput,
20268 	.tfb_tcp_fb_init = rack_init,
20269 	.tfb_tcp_fb_fini = rack_fini,
20270 	.tfb_tcp_timer_stop_all = rack_stopall,
20271 	.tfb_tcp_rexmit_tmr = rack_remxt_tmr,
20272 	.tfb_tcp_handoff_ok = rack_handoff_ok,
20273 	.tfb_tcp_mtu_chg = rack_mtu_change,
20274 	.tfb_pru_options = rack_pru_options,
20275 	.tfb_hwtls_change = rack_hw_tls_change,
20276 	.tfb_compute_pipe = rack_compute_pipe,
20277 	.tfb_flags = TCP_FUNC_OUTPUT_CANDROP,
20278 };
20279 
20280 /*
20281  * rack_ctloutput() must drop the inpcb lock before performing copyin on
20282  * socket option arguments.  When it re-acquires the lock after the copy, it
20283  * has to revalidate that the connection is still valid for the socket
20284  * option.
20285  */
20286 static int
20287 rack_set_sockopt(struct inpcb *inp, struct sockopt *sopt)
20288 {
20289 #ifdef INET6
20290 	struct ip6_hdr *ip6;
20291 #endif
20292 #ifdef INET
20293 	struct ip *ip;
20294 #endif
20295 	struct tcpcb *tp;
20296 	struct tcp_rack *rack;
20297 	uint64_t loptval;
20298 	int32_t error = 0, optval;
20299 
20300 	tp = intotcpcb(inp);
20301 	rack = (struct tcp_rack *)tp->t_fb_ptr;
20302 	if (rack == NULL) {
20303 		INP_WUNLOCK(inp);
20304 		return (EINVAL);
20305 	}
20306 #ifdef INET6
20307 	ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
20308 #endif
20309 #ifdef INET
20310 	ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
20311 #endif
20312 
20313 	switch (sopt->sopt_level) {
20314 #ifdef INET6
20315 	case IPPROTO_IPV6:
20316 		MPASS(inp->inp_vflag & INP_IPV6PROTO);
20317 		switch (sopt->sopt_name) {
20318 		case IPV6_USE_MIN_MTU:
20319 			tcp6_use_min_mtu(tp);
20320 			break;
20321 		case IPV6_TCLASS:
20322 			/*
20323 			 * The DSCP codepoint has changed, update the fsb.
20324 			 */
20325 			ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
20326 			    (rack->rc_inp->inp_flow & IPV6_FLOWINFO_MASK);
20327 			break;
20328 		}
20329 		INP_WUNLOCK(inp);
20330 		return (0);
20331 #endif
20332 #ifdef INET
20333 	case IPPROTO_IP:
20334 		switch (sopt->sopt_name) {
20335 		case IP_TOS:
20336 			/*
20337 			 * The DSCP codepoint has changed, update the fsb.
20338 			 */
20339 			ip->ip_tos = rack->rc_inp->inp_ip_tos;
20340 			break;
20341 		case IP_TTL:
20342 			/*
20343 			 * The TTL has changed, update the fsb.
20344 			 */
20345 			ip->ip_ttl = rack->rc_inp->inp_ip_ttl;
20346 			break;
20347 		}
20348 		INP_WUNLOCK(inp);
20349 		return (0);
20350 #endif
20351 	}
20352 
20353 	switch (sopt->sopt_name) {
20354 	case TCP_RACK_TLP_REDUCE:		/*  URL:tlp_reduce */
20355 	/*  Pacing related ones */
20356 	case TCP_RACK_PACE_ALWAYS:		/*  URL:pace_always */
20357 	case TCP_BBR_RACK_INIT_RATE:		/*  URL:irate */
20358 	case TCP_BBR_IWINTSO:			/*  URL:tso_iwin */
20359 	case TCP_RACK_PACE_MAX_SEG:		/*  URL:pace_max_seg */
20360 	case TCP_RACK_FORCE_MSEG:		/*  URL:force_max_seg */
20361 	case TCP_RACK_PACE_RATE_CA:		/*  URL:pr_ca */
20362 	case TCP_RACK_PACE_RATE_SS:		/*  URL:pr_ss*/
20363 	case TCP_RACK_PACE_RATE_REC:		/*  URL:pr_rec */
20364 	case TCP_RACK_GP_INCREASE_CA:		/*  URL:gp_inc_ca */
20365 	case TCP_RACK_GP_INCREASE_SS:		/*  URL:gp_inc_ss */
20366 	case TCP_RACK_GP_INCREASE_REC:		/*  URL:gp_inc_rec */
20367 	case TCP_RACK_RR_CONF:			/*  URL:rrr_conf */
20368 	case TCP_BBR_HDWR_PACE:			/*  URL:hdwrpace */
20369 	case TCP_HDWR_RATE_CAP:			/*  URL:hdwrcap boolean */
20370 	case TCP_PACING_RATE_CAP:		/*  URL:cap  -- used by side-channel */
20371 	case TCP_HDWR_UP_ONLY:			/*  URL:uponly -- hardware pacing  boolean */
20372        /* End pacing related */
20373 	case TCP_FAST_RSM_HACK:			/*  URL:frsm_hack */
20374 	case TCP_DELACK:			/*  URL:delack (in base TCP i.e. tcp_hints along with cc etc ) */
20375 	case TCP_RACK_PRR_SENDALOT:		/*  URL:prr_sendalot */
20376 	case TCP_RACK_MIN_TO:			/*  URL:min_to */
20377 	case TCP_RACK_EARLY_SEG:		/*  URL:early_seg */
20378 	case TCP_RACK_REORD_THRESH:		/*  URL:reord_thresh */
20379 	case TCP_RACK_REORD_FADE:		/*  URL:reord_fade */
20380 	case TCP_RACK_TLP_THRESH:		/*  URL:tlp_thresh */
20381 	case TCP_RACK_PKT_DELAY:		/*  URL:pkt_delay */
20382 	case TCP_RACK_TLP_USE:			/*  URL:tlp_use */
20383 	case TCP_BBR_RACK_RTT_USE:		/*  URL:rttuse */
20384 	case TCP_BBR_USE_RACK_RR:		/*  URL:rackrr */
20385 	case TCP_RACK_DO_DETECTION:		/*  URL:detect */
20386 	case TCP_NO_PRR:			/*  URL:noprr */
20387 	case TCP_TIMELY_DYN_ADJ:      		/*  URL:dynamic */
20388 	case TCP_DATA_AFTER_CLOSE:		/*  no URL */
20389 	case TCP_RACK_NONRXT_CFG_RATE:		/*  URL:nonrxtcr */
20390 	case TCP_SHARED_CWND_ENABLE:		/*  URL:scwnd */
20391 	case TCP_RACK_MBUF_QUEUE:		/*  URL:mqueue */
20392 	case TCP_RACK_NO_PUSH_AT_MAX:		/*  URL:npush */
20393 	case TCP_RACK_PACE_TO_FILL:		/*  URL:fillcw */
20394 	case TCP_SHARED_CWND_TIME_LIMIT:	/*  URL:lscwnd */
20395 	case TCP_RACK_PROFILE:			/*  URL:profile */
20396 	case TCP_USE_CMP_ACKS:			/*  URL:cmpack */
20397 	case TCP_RACK_ABC_VAL:			/*  URL:labc */
20398 	case TCP_REC_ABC_VAL:			/*  URL:reclabc */
20399 	case TCP_RACK_MEASURE_CNT:		/*  URL:measurecnt */
20400 	case TCP_DEFER_OPTIONS:			/*  URL:defer */
20401 	case TCP_RACK_DSACK_OPT:		/*  URL:dsack */
20402 	case TCP_RACK_PACING_BETA:		/*  URL:pacing_beta */
20403 	case TCP_RACK_PACING_BETA_ECN:		/*  URL:pacing_beta_ecn */
20404 	case TCP_RACK_TIMER_SLOP:		/*  URL:timer_slop */
20405 	case TCP_RACK_ENABLE_HYSTART:		/*  URL:hystart */
20406 		break;
20407 	default:
20408 		/* Filter off all unknown options to the base stack */
20409 		return (tcp_default_ctloutput(inp, sopt));
20410 		break;
20411 	}
20412 	INP_WUNLOCK(inp);
20413 	if (sopt->sopt_name == TCP_PACING_RATE_CAP) {
20414 		error = sooptcopyin(sopt, &loptval, sizeof(loptval), sizeof(loptval));
20415 		/*
20416 		 * We truncate it down to 32 bits for the socket-option trace this
20417 		 * means rates > 34Gbps won't show right, but thats probably ok.
20418 		 */
20419 		optval = (uint32_t)loptval;
20420 	} else {
20421 		error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval));
20422 		/* Save it in 64 bit form too */
20423 		loptval = optval;
20424 	}
20425 	if (error)
20426 		return (error);
20427 	INP_WLOCK(inp);
20428 	if (inp->inp_flags & INP_DROPPED) {
20429 		INP_WUNLOCK(inp);
20430 		return (ECONNRESET);
20431 	}
20432 	if (tp->t_fb != &__tcp_rack) {
20433 		INP_WUNLOCK(inp);
20434 		return (ENOPROTOOPT);
20435 	}
20436 	if (rack->defer_options && (rack->gp_ready == 0) &&
20437 	    (sopt->sopt_name != TCP_DEFER_OPTIONS) &&
20438 	    (sopt->sopt_name != TCP_RACK_PACING_BETA) &&
20439 	    (sopt->sopt_name != TCP_RACK_PACING_BETA_ECN) &&
20440 	    (sopt->sopt_name != TCP_RACK_MEASURE_CNT)) {
20441 		/* Options are beind deferred */
20442 		if (rack_add_deferred_option(rack, sopt->sopt_name, loptval)) {
20443 			INP_WUNLOCK(inp);
20444 			return (0);
20445 		} else {
20446 			/* No memory to defer, fail */
20447 			INP_WUNLOCK(inp);
20448 			return (ENOMEM);
20449 		}
20450 	}
20451 	error = rack_process_option(tp, rack, sopt->sopt_name, optval, loptval);
20452 	INP_WUNLOCK(inp);
20453 	return (error);
20454 }
20455 
20456 static void
20457 rack_fill_info(struct tcpcb *tp, struct tcp_info *ti)
20458 {
20459 
20460 	INP_WLOCK_ASSERT(tptoinpcb(tp));
20461 	bzero(ti, sizeof(*ti));
20462 
20463 	ti->tcpi_state = tp->t_state;
20464 	if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
20465 		ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
20466 	if (tp->t_flags & TF_SACK_PERMIT)
20467 		ti->tcpi_options |= TCPI_OPT_SACK;
20468 	if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
20469 		ti->tcpi_options |= TCPI_OPT_WSCALE;
20470 		ti->tcpi_snd_wscale = tp->snd_scale;
20471 		ti->tcpi_rcv_wscale = tp->rcv_scale;
20472 	}
20473 	if (tp->t_flags2 & (TF2_ECN_PERMIT | TF2_ACE_PERMIT))
20474 		ti->tcpi_options |= TCPI_OPT_ECN;
20475 	if (tp->t_flags & TF_FASTOPEN)
20476 		ti->tcpi_options |= TCPI_OPT_TFO;
20477 	/* still kept in ticks is t_rcvtime */
20478 	ti->tcpi_last_data_recv = ((uint32_t)ticks - tp->t_rcvtime) * tick;
20479 	/* Since we hold everything in precise useconds this is easy */
20480 	ti->tcpi_rtt = tp->t_srtt;
20481 	ti->tcpi_rttvar = tp->t_rttvar;
20482 	ti->tcpi_rto = tp->t_rxtcur;
20483 	ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
20484 	ti->tcpi_snd_cwnd = tp->snd_cwnd;
20485 	/*
20486 	 * FreeBSD-specific extension fields for tcp_info.
20487 	 */
20488 	ti->tcpi_rcv_space = tp->rcv_wnd;
20489 	ti->tcpi_rcv_nxt = tp->rcv_nxt;
20490 	ti->tcpi_snd_wnd = tp->snd_wnd;
20491 	ti->tcpi_snd_bwnd = 0;		/* Unused, kept for compat. */
20492 	ti->tcpi_snd_nxt = tp->snd_nxt;
20493 	ti->tcpi_snd_mss = tp->t_maxseg;
20494 	ti->tcpi_rcv_mss = tp->t_maxseg;
20495 	ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;
20496 	ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
20497 	ti->tcpi_snd_zerowin = tp->t_sndzerowin;
20498 #ifdef NETFLIX_STATS
20499 	ti->tcpi_total_tlp = tp->t_sndtlppack;
20500 	ti->tcpi_total_tlp_bytes = tp->t_sndtlpbyte;
20501 	memcpy(&ti->tcpi_rxsyninfo, &tp->t_rxsyninfo, sizeof(struct tcpsyninfo));
20502 #endif
20503 #ifdef TCP_OFFLOAD
20504 	if (tp->t_flags & TF_TOE) {
20505 		ti->tcpi_options |= TCPI_OPT_TOE;
20506 		tcp_offload_tcp_info(tp, ti);
20507 	}
20508 #endif
20509 }
20510 
20511 static int
20512 rack_get_sockopt(struct inpcb *inp, struct sockopt *sopt)
20513 {
20514 	struct tcpcb *tp;
20515 	struct tcp_rack *rack;
20516 	int32_t error, optval;
20517 	uint64_t val, loptval;
20518 	struct	tcp_info ti;
20519 	/*
20520 	 * Because all our options are either boolean or an int, we can just
20521 	 * pull everything into optval and then unlock and copy. If we ever
20522 	 * add a option that is not a int, then this will have quite an
20523 	 * impact to this routine.
20524 	 */
20525 	error = 0;
20526 	tp = intotcpcb(inp);
20527 	rack = (struct tcp_rack *)tp->t_fb_ptr;
20528 	if (rack == NULL) {
20529 		INP_WUNLOCK(inp);
20530 		return (EINVAL);
20531 	}
20532 	switch (sopt->sopt_name) {
20533 	case TCP_INFO:
20534 		/* First get the info filled */
20535 		rack_fill_info(tp, &ti);
20536 		/* Fix up the rtt related fields if needed */
20537 		INP_WUNLOCK(inp);
20538 		error = sooptcopyout(sopt, &ti, sizeof ti);
20539 		return (error);
20540 	/*
20541 	 * Beta is the congestion control value for NewReno that influences how
20542 	 * much of a backoff happens when loss is detected. It is normally set
20543 	 * to 50 for 50% i.e. the cwnd is reduced to 50% of its previous value
20544 	 * when you exit recovery.
20545 	 */
20546 	case TCP_RACK_PACING_BETA:
20547 		if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0)
20548 			error = EINVAL;
20549 		else if (rack->rc_pacing_cc_set == 0)
20550 			optval = rack->r_ctl.rc_saved_beta.beta;
20551 		else {
20552 			/*
20553 			 * Reach out into the CC data and report back what
20554 			 * I have previously set. Yeah it looks hackish but
20555 			 * we don't want to report the saved values.
20556 			 */
20557 			if (tp->t_ccv.cc_data)
20558 				optval = ((struct newreno *)tp->t_ccv.cc_data)->beta;
20559 			else
20560 				error = EINVAL;
20561 		}
20562 		break;
20563 		/*
20564 		 * Beta_ecn is the congestion control value for NewReno that influences how
20565 		 * much of a backoff happens when a ECN mark is detected. It is normally set
20566 		 * to 80 for 80% i.e. the cwnd is reduced by 20% of its previous value when
20567 		 * you exit recovery. Note that classic ECN has a beta of 50, it is only
20568 		 * ABE Ecn that uses this "less" value, but we do too with pacing :)
20569 		 */
20570 
20571 	case TCP_RACK_PACING_BETA_ECN:
20572 		if (strcmp(tp->t_cc->name, CCALGONAME_NEWRENO) != 0)
20573 			error = EINVAL;
20574 		else if (rack->rc_pacing_cc_set == 0)
20575 			optval = rack->r_ctl.rc_saved_beta.beta_ecn;
20576 		else {
20577 			/*
20578 			 * Reach out into the CC data and report back what
20579 			 * I have previously set. Yeah it looks hackish but
20580 			 * we don't want to report the saved values.
20581 			 */
20582 			if (tp->t_ccv.cc_data)
20583 				optval = ((struct newreno *)tp->t_ccv.cc_data)->beta_ecn;
20584 			else
20585 				error = EINVAL;
20586 		}
20587 		break;
20588 	case TCP_RACK_DSACK_OPT:
20589 		optval = 0;
20590 		if (rack->rc_rack_tmr_std_based) {
20591 			optval |= 1;
20592 		}
20593 		if (rack->rc_rack_use_dsack) {
20594 			optval |= 2;
20595 		}
20596 		break;
20597  	case TCP_RACK_ENABLE_HYSTART:
20598 	{
20599 		if (tp->t_ccv.flags & CCF_HYSTART_ALLOWED) {
20600 			optval = RACK_HYSTART_ON;
20601 			if (tp->t_ccv.flags & CCF_HYSTART_CAN_SH_CWND)
20602 				optval = RACK_HYSTART_ON_W_SC;
20603 			if (tp->t_ccv.flags & CCF_HYSTART_CONS_SSTH)
20604 				optval = RACK_HYSTART_ON_W_SC_C;
20605 		} else {
20606 			optval = RACK_HYSTART_OFF;
20607 		}
20608 	}
20609 	break;
20610 	case TCP_FAST_RSM_HACK:
20611 		optval = rack->fast_rsm_hack;
20612 		break;
20613 	case TCP_DEFER_OPTIONS:
20614 		optval = rack->defer_options;
20615 		break;
20616 	case TCP_RACK_MEASURE_CNT:
20617 		optval = rack->r_ctl.req_measurements;
20618 		break;
20619 	case TCP_REC_ABC_VAL:
20620 		optval = rack->r_use_labc_for_rec;
20621 		break;
20622 	case TCP_RACK_ABC_VAL:
20623 		optval = rack->rc_labc;
20624 		break;
20625 	case TCP_HDWR_UP_ONLY:
20626 		optval= rack->r_up_only;
20627 		break;
20628 	case TCP_PACING_RATE_CAP:
20629 		loptval = rack->r_ctl.bw_rate_cap;
20630 		break;
20631 	case TCP_RACK_PROFILE:
20632 		/* You cannot retrieve a profile, its write only */
20633 		error = EINVAL;
20634 		break;
20635 	case TCP_USE_CMP_ACKS:
20636 		optval = rack->r_use_cmp_ack;
20637 		break;
20638 	case TCP_RACK_PACE_TO_FILL:
20639 		optval = rack->rc_pace_to_cwnd;
20640 		if (optval && rack->r_fill_less_agg)
20641 			optval++;
20642 		break;
20643 	case TCP_RACK_NO_PUSH_AT_MAX:
20644 		optval = rack->r_ctl.rc_no_push_at_mrtt;
20645 		break;
20646 	case TCP_SHARED_CWND_ENABLE:
20647 		optval = rack->rack_enable_scwnd;
20648 		break;
20649 	case TCP_RACK_NONRXT_CFG_RATE:
20650 		optval = rack->rack_rec_nonrxt_use_cr;
20651 		break;
20652 	case TCP_NO_PRR:
20653 		if (rack->rack_no_prr  == 1)
20654 			optval = 1;
20655 		else if (rack->no_prr_addback == 1)
20656 			optval = 2;
20657 		else
20658 			optval = 0;
20659 		break;
20660 	case TCP_RACK_DO_DETECTION:
20661 		optval = rack->do_detection;
20662 		break;
20663 	case TCP_RACK_MBUF_QUEUE:
20664 		/* Now do we use the LRO mbuf-queue feature */
20665 		optval = rack->r_mbuf_queue;
20666 		break;
20667 	case TCP_TIMELY_DYN_ADJ:
20668 		optval = rack->rc_gp_dyn_mul;
20669 		break;
20670 	case TCP_BBR_IWINTSO:
20671 		optval = rack->rc_init_win;
20672 		break;
20673 	case TCP_RACK_TLP_REDUCE:
20674 		/* RACK TLP cwnd reduction (bool) */
20675 		optval = rack->r_ctl.rc_tlp_cwnd_reduce;
20676 		break;
20677 	case TCP_BBR_RACK_INIT_RATE:
20678 		val = rack->r_ctl.init_rate;
20679 		/* convert to kbits per sec */
20680 		val *= 8;
20681 		val /= 1000;
20682 		optval = (uint32_t)val;
20683 		break;
20684 	case TCP_RACK_FORCE_MSEG:
20685 		optval = rack->rc_force_max_seg;
20686 		break;
20687 	case TCP_RACK_PACE_MAX_SEG:
20688 		/* Max segments in a pace */
20689 		optval = rack->rc_user_set_max_segs;
20690 		break;
20691 	case TCP_RACK_PACE_ALWAYS:
20692 		/* Use the always pace method */
20693 		optval = rack->rc_always_pace;
20694 		break;
20695 	case TCP_RACK_PRR_SENDALOT:
20696 		/* Allow PRR to send more than one seg */
20697 		optval = rack->r_ctl.rc_prr_sendalot;
20698 		break;
20699 	case TCP_RACK_MIN_TO:
20700 		/* Minimum time between rack t-o's in ms */
20701 		optval = rack->r_ctl.rc_min_to;
20702 		break;
20703 	case TCP_RACK_EARLY_SEG:
20704 		/* If early recovery max segments */
20705 		optval = rack->r_ctl.rc_early_recovery_segs;
20706 		break;
20707 	case TCP_RACK_REORD_THRESH:
20708 		/* RACK reorder threshold (shift amount) */
20709 		optval = rack->r_ctl.rc_reorder_shift;
20710 		break;
20711 	case TCP_RACK_REORD_FADE:
20712 		/* Does reordering fade after ms time */
20713 		optval = rack->r_ctl.rc_reorder_fade;
20714 		break;
20715 	case TCP_BBR_USE_RACK_RR:
20716 		/* Do we use the rack cheat for rxt */
20717 		optval = rack->use_rack_rr;
20718 		break;
20719 	case TCP_RACK_RR_CONF:
20720 		optval = rack->r_rr_config;
20721 		break;
20722 	case TCP_HDWR_RATE_CAP:
20723 		optval = rack->r_rack_hw_rate_caps;
20724 		break;
20725 	case TCP_BBR_HDWR_PACE:
20726 		optval = rack->rack_hdw_pace_ena;
20727 		break;
20728 	case TCP_RACK_TLP_THRESH:
20729 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
20730 		optval = rack->r_ctl.rc_tlp_threshold;
20731 		break;
20732 	case TCP_RACK_PKT_DELAY:
20733 		/* RACK added ms i.e. rack-rtt + reord + N */
20734 		optval = rack->r_ctl.rc_pkt_delay;
20735 		break;
20736 	case TCP_RACK_TLP_USE:
20737 		optval = rack->rack_tlp_threshold_use;
20738 		break;
20739 	case TCP_RACK_PACE_RATE_CA:
20740 		optval = rack->r_ctl.rc_fixed_pacing_rate_ca;
20741 		break;
20742 	case TCP_RACK_PACE_RATE_SS:
20743 		optval = rack->r_ctl.rc_fixed_pacing_rate_ss;
20744 		break;
20745 	case TCP_RACK_PACE_RATE_REC:
20746 		optval = rack->r_ctl.rc_fixed_pacing_rate_rec;
20747 		break;
20748 	case TCP_RACK_GP_INCREASE_SS:
20749 		optval = rack->r_ctl.rack_per_of_gp_ca;
20750 		break;
20751 	case TCP_RACK_GP_INCREASE_CA:
20752 		optval = rack->r_ctl.rack_per_of_gp_ss;
20753 		break;
20754 	case TCP_BBR_RACK_RTT_USE:
20755 		optval = rack->r_ctl.rc_rate_sample_method;
20756 		break;
20757 	case TCP_DELACK:
20758 		optval = tp->t_delayed_ack;
20759 		break;
20760 	case TCP_DATA_AFTER_CLOSE:
20761 		optval = rack->rc_allow_data_af_clo;
20762 		break;
20763 	case TCP_SHARED_CWND_TIME_LIMIT:
20764 		optval = rack->r_limit_scw;
20765 		break;
20766 	case TCP_RACK_TIMER_SLOP:
20767 		optval = rack->r_ctl.timer_slop;
20768 		break;
20769 	default:
20770 		return (tcp_default_ctloutput(inp, sopt));
20771 		break;
20772 	}
20773 	INP_WUNLOCK(inp);
20774 	if (error == 0) {
20775 		if (TCP_PACING_RATE_CAP)
20776 			error = sooptcopyout(sopt, &loptval, sizeof loptval);
20777 		else
20778 			error = sooptcopyout(sopt, &optval, sizeof optval);
20779 	}
20780 	return (error);
20781 }
20782 
20783 static int
20784 rack_ctloutput(struct inpcb *inp, struct sockopt *sopt)
20785 {
20786 	if (sopt->sopt_dir == SOPT_SET) {
20787 		return (rack_set_sockopt(inp, sopt));
20788 	} else if (sopt->sopt_dir == SOPT_GET) {
20789 		return (rack_get_sockopt(inp, sopt));
20790 	} else {
20791 		panic("%s: sopt_dir $%d", __func__, sopt->sopt_dir);
20792 	}
20793 }
20794 
20795 static const char *rack_stack_names[] = {
20796 	__XSTRING(STACKNAME),
20797 #ifdef STACKALIAS
20798 	__XSTRING(STACKALIAS),
20799 #endif
20800 };
20801 
20802 static int
20803 rack_ctor(void *mem, int32_t size, void *arg, int32_t how)
20804 {
20805 	memset(mem, 0, size);
20806 	return (0);
20807 }
20808 
20809 static void
20810 rack_dtor(void *mem, int32_t size, void *arg)
20811 {
20812 
20813 }
20814 
20815 static bool rack_mod_inited = false;
20816 
20817 static int
20818 tcp_addrack(module_t mod, int32_t type, void *data)
20819 {
20820 	int32_t err = 0;
20821 	int num_stacks;
20822 
20823 	switch (type) {
20824 	case MOD_LOAD:
20825 		rack_zone = uma_zcreate(__XSTRING(MODNAME) "_map",
20826 		    sizeof(struct rack_sendmap),
20827 		    rack_ctor, rack_dtor, NULL, NULL, UMA_ALIGN_PTR, 0);
20828 
20829 		rack_pcb_zone = uma_zcreate(__XSTRING(MODNAME) "_pcb",
20830 		    sizeof(struct tcp_rack),
20831 		    rack_ctor, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
20832 
20833 		sysctl_ctx_init(&rack_sysctl_ctx);
20834 		rack_sysctl_root = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
20835 		    SYSCTL_STATIC_CHILDREN(_net_inet_tcp),
20836 		    OID_AUTO,
20837 #ifdef STACKALIAS
20838 		    __XSTRING(STACKALIAS),
20839 #else
20840 		    __XSTRING(STACKNAME),
20841 #endif
20842 		    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
20843 		    "");
20844 		if (rack_sysctl_root == NULL) {
20845 			printf("Failed to add sysctl node\n");
20846 			err = EFAULT;
20847 			goto free_uma;
20848 		}
20849 		rack_init_sysctls();
20850 		num_stacks = nitems(rack_stack_names);
20851 		err = register_tcp_functions_as_names(&__tcp_rack, M_WAITOK,
20852 		    rack_stack_names, &num_stacks);
20853 		if (err) {
20854 			printf("Failed to register %s stack name for "
20855 			    "%s module\n", rack_stack_names[num_stacks],
20856 			    __XSTRING(MODNAME));
20857 			sysctl_ctx_free(&rack_sysctl_ctx);
20858 free_uma:
20859 			uma_zdestroy(rack_zone);
20860 			uma_zdestroy(rack_pcb_zone);
20861 			rack_counter_destroy();
20862 			printf("Failed to register rack module -- err:%d\n", err);
20863 			return (err);
20864 		}
20865 		tcp_lro_reg_mbufq();
20866 		rack_mod_inited = true;
20867 		break;
20868 	case MOD_QUIESCE:
20869 		err = deregister_tcp_functions(&__tcp_rack, true, false);
20870 		break;
20871 	case MOD_UNLOAD:
20872 		err = deregister_tcp_functions(&__tcp_rack, false, true);
20873 		if (err == EBUSY)
20874 			break;
20875 		if (rack_mod_inited) {
20876 			uma_zdestroy(rack_zone);
20877 			uma_zdestroy(rack_pcb_zone);
20878 			sysctl_ctx_free(&rack_sysctl_ctx);
20879 			rack_counter_destroy();
20880 			rack_mod_inited = false;
20881 		}
20882 		tcp_lro_dereg_mbufq();
20883 		err = 0;
20884 		break;
20885 	default:
20886 		return (EOPNOTSUPP);
20887 	}
20888 	return (err);
20889 }
20890 
20891 static moduledata_t tcp_rack = {
20892 	.name = __XSTRING(MODNAME),
20893 	.evhand = tcp_addrack,
20894 	.priv = 0
20895 };
20896 
20897 MODULE_VERSION(MODNAME, 1);
20898 DECLARE_MODULE(MODNAME, tcp_rack, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
20899 MODULE_DEPEND(MODNAME, tcphpts, 1, 1, 1);
20900