xref: /freebsd/sys/netinet/tcp_stacks/rack.c (revision 79ac3c12a714bcd3f2354c52d948aed9575c46d6) 
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 <sys/param.h>
36 #include <sys/arb.h>
37 #include <sys/module.h>
38 #include <sys/kernel.h>
39 #ifdef TCP_HHOOK
40 #include <sys/hhook.h>
41 #endif
42 #include <sys/lock.h>
43 #include <sys/malloc.h>
44 #include <sys/lock.h>
45 #include <sys/mutex.h>
46 #include <sys/mbuf.h>
47 #include <sys/proc.h>		/* for proc0 declaration */
48 #include <sys/socket.h>
49 #include <sys/socketvar.h>
50 #include <sys/sysctl.h>
51 #include <sys/systm.h>
52 #ifdef STATS
53 #include <sys/qmath.h>
54 #include <sys/tree.h>
55 #include <sys/stats.h> /* Must come after qmath.h and tree.h */
56 #else
57 #include <sys/tree.h>
58 #endif
59 #include <sys/refcount.h>
60 #include <sys/queue.h>
61 #include <sys/tim_filter.h>
62 #include <sys/smp.h>
63 #include <sys/kthread.h>
64 #include <sys/kern_prefetch.h>
65 #include <sys/protosw.h>
66 #ifdef TCP_ACCOUNTING
67 #include <sys/sched.h>
68 #include <machine/cpu.h>
69 #endif
70 #include <vm/uma.h>
71 
72 #include <net/route.h>
73 #include <net/route/nhop.h>
74 #include <net/vnet.h>
75 
76 #define TCPSTATES		/* for logging */
77 
78 #include <netinet/in.h>
79 #include <netinet/in_kdtrace.h>
80 #include <netinet/in_pcb.h>
81 #include <netinet/ip.h>
82 #include <netinet/ip_icmp.h>	/* required for icmp_var.h */
83 #include <netinet/icmp_var.h>	/* for ICMP_BANDLIM */
84 #include <netinet/ip_var.h>
85 #include <netinet/ip6.h>
86 #include <netinet6/in6_pcb.h>
87 #include <netinet6/ip6_var.h>
88 #include <netinet/tcp.h>
89 #define	TCPOUTFLAGS
90 #include <netinet/tcp_fsm.h>
91 #include <netinet/tcp_log_buf.h>
92 #include <netinet/tcp_seq.h>
93 #include <netinet/tcp_timer.h>
94 #include <netinet/tcp_var.h>
95 #include <netinet/tcp_hpts.h>
96 #include <netinet/tcp_ratelimit.h>
97 #include <netinet/tcp_accounting.h>
98 #include <netinet/tcpip.h>
99 #include <netinet/cc/cc.h>
100 #include <netinet/cc/cc_newreno.h>
101 #include <netinet/tcp_fastopen.h>
102 #include <netinet/tcp_lro.h>
103 #ifdef NETFLIX_SHARED_CWND
104 #include <netinet/tcp_shared_cwnd.h>
105 #endif
106 #ifdef TCPDEBUG
107 #include <netinet/tcp_debug.h>
108 #endif				/* TCPDEBUG */
109 #ifdef TCP_OFFLOAD
110 #include <netinet/tcp_offload.h>
111 #endif
112 #ifdef INET6
113 #include <netinet6/tcp6_var.h>
114 #endif
115 
116 #include <netipsec/ipsec_support.h>
117 
118 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
119 #include <netipsec/ipsec.h>
120 #include <netipsec/ipsec6.h>
121 #endif				/* IPSEC */
122 
123 #include <netinet/udp.h>
124 #include <netinet/udp_var.h>
125 #include <machine/in_cksum.h>
126 
127 #ifdef MAC
128 #include <security/mac/mac_framework.h>
129 #endif
130 #include "sack_filter.h"
131 #include "tcp_rack.h"
132 #include "rack_bbr_common.h"
133 
134 uma_zone_t rack_zone;
135 uma_zone_t rack_pcb_zone;
136 
137 #ifndef TICKS2SBT
138 #define	TICKS2SBT(__t)	(tick_sbt * ((sbintime_t)(__t)))
139 #endif
140 
141 VNET_DECLARE(uint32_t, newreno_beta);
142 VNET_DECLARE(uint32_t, newreno_beta_ecn);
143 #define V_newreno_beta VNET(newreno_beta)
144 #define V_newreno_beta_ecn VNET(newreno_beta_ecn)
145 
146 
147 MALLOC_DEFINE(M_TCPFSB, "tcp_fsb", "TCP fast send block");
148 MALLOC_DEFINE(M_TCPDO, "tcp_do", "TCP deferred options");
149 
150 struct sysctl_ctx_list rack_sysctl_ctx;
151 struct sysctl_oid *rack_sysctl_root;
152 
153 #define CUM_ACKED 1
154 #define SACKED 2
155 
156 /*
157  * The RACK module incorporates a number of
158  * TCP ideas that have been put out into the IETF
159  * over the last few years:
160  * - Matt Mathis's Rate Halving which slowly drops
161  *    the congestion window so that the ack clock can
162  *    be maintained during a recovery.
163  * - Yuchung Cheng's RACK TCP (for which its named) that
164  *    will stop us using the number of dup acks and instead
165  *    use time as the gage of when we retransmit.
166  * - Reorder Detection of RFC4737 and the Tail-Loss probe draft
167  *    of Dukkipati et.al.
168  * RACK depends on SACK, so if an endpoint arrives that
169  * cannot do SACK the state machine below will shuttle the
170  * connection back to using the "default" TCP stack that is
171  * in FreeBSD.
172  *
173  * To implement RACK the original TCP stack was first decomposed
174  * into a functional state machine with individual states
175  * for each of the possible TCP connection states. The do_segement
176  * functions role in life is to mandate the connection supports SACK
177  * initially and then assure that the RACK state matches the conenction
178  * state before calling the states do_segment function. Each
179  * state is simplified due to the fact that the original do_segment
180  * has been decomposed and we *know* what state we are in (no
181  * switches on the state) and all tests for SACK are gone. This
182  * greatly simplifies what each state does.
183  *
184  * TCP output is also over-written with a new version since it
185  * must maintain the new rack scoreboard.
186  *
187  */
188 static int32_t rack_tlp_thresh = 1;
189 static int32_t rack_tlp_limit = 2;	/* No more than 2 TLPs w-out new data */
190 static int32_t rack_tlp_use_greater = 1;
191 static int32_t rack_reorder_thresh = 2;
192 static int32_t rack_reorder_fade = 60000000;	/* 0 - never fade, def 60,000,000
193 						 * - 60 seconds */
194 static uint8_t rack_req_measurements = 1;
195 /* Attack threshold detections */
196 static uint32_t rack_highest_sack_thresh_seen = 0;
197 static uint32_t rack_highest_move_thresh_seen = 0;
198 static int32_t rack_enable_hw_pacing = 0; /* Due to CCSP keep it off by default */
199 static int32_t rack_hw_pace_extra_slots = 2;	/* 2 extra MSS time betweens */
200 static int32_t rack_hw_rate_caps = 1; /* 1; */
201 static int32_t rack_hw_rate_min = 0; /* 1500000;*/
202 static int32_t rack_hw_rate_to_low = 0; /* 1200000; */
203 static int32_t rack_hw_up_only = 1;
204 static int32_t rack_stats_gets_ms_rtt = 1;
205 static int32_t rack_prr_addbackmax = 2;
206 
207 static int32_t rack_pkt_delay = 1000;
208 static int32_t rack_send_a_lot_in_prr = 1;
209 static int32_t rack_min_to = 1000;	/* Number of microsecond  min timeout */
210 static int32_t rack_verbose_logging = 0;
211 static int32_t rack_ignore_data_after_close = 1;
212 static int32_t rack_enable_shared_cwnd = 1;
213 static int32_t rack_use_cmp_acks = 1;
214 static int32_t rack_use_fsb = 1;
215 static int32_t rack_use_rfo = 1;
216 static int32_t rack_use_rsm_rfo = 1;
217 static int32_t rack_max_abc_post_recovery = 2;
218 static int32_t rack_client_low_buf = 0;
219 #ifdef TCP_ACCOUNTING
220 static int32_t rack_tcp_accounting = 0;
221 #endif
222 static int32_t rack_limits_scwnd = 1;
223 static int32_t rack_enable_mqueue_for_nonpaced = 0;
224 static int32_t rack_disable_prr = 0;
225 static int32_t use_rack_rr = 1;
226 static int32_t rack_non_rxt_use_cr = 0; /* does a non-rxt in recovery use the configured rate (ss/ca)? */
227 static int32_t rack_persist_min = 250000;	/* 250usec */
228 static int32_t rack_persist_max = 2000000;	/* 2 Second in usec's */
229 static int32_t rack_sack_not_required = 1;	/* set to one to allow non-sack to use rack */
230 static int32_t rack_default_init_window = 0;	/* Use system default */
231 static int32_t rack_limit_time_with_srtt = 0;
232 static int32_t rack_autosndbuf_inc = 20;	/* In percentage form */
233 static int32_t rack_enobuf_hw_boost_mult = 2;	/* How many times the hw rate we boost slot using time_between */
234 static int32_t rack_enobuf_hw_max = 12000;	/* 12 ms in usecs */
235 static int32_t rack_enobuf_hw_min = 10000;	/* 10 ms in usecs */
236 static int32_t rack_hw_rwnd_factor = 2;		/* How many max_segs the rwnd must be before we hold off sending */
237 /*
238  * Currently regular tcp has a rto_min of 30ms
239  * the backoff goes 12 times so that ends up
240  * being a total of 122.850 seconds before a
241  * connection is killed.
242  */
243 static uint32_t rack_def_data_window = 20;
244 static uint32_t rack_goal_bdp = 2;
245 static uint32_t rack_min_srtts = 1;
246 static uint32_t rack_min_measure_usec = 0;
247 static int32_t rack_tlp_min = 10000;	/* 10ms */
248 static int32_t rack_rto_min = 30000;	/* 30,000 usec same as main freebsd */
249 static int32_t rack_rto_max = 4000000;	/* 4 seconds in usec's */
250 static const int32_t rack_free_cache = 2;
251 static int32_t rack_hptsi_segments = 40;
252 static int32_t rack_rate_sample_method = USE_RTT_LOW;
253 static int32_t rack_pace_every_seg = 0;
254 static int32_t rack_delayed_ack_time = 40000;	/* 40ms in usecs */
255 static int32_t rack_slot_reduction = 4;
256 static int32_t rack_wma_divisor = 8;		/* For WMA calculation */
257 static int32_t rack_cwnd_block_ends_measure = 0;
258 static int32_t rack_rwnd_block_ends_measure = 0;
259 static int32_t rack_def_profile = 0;
260 
261 static int32_t rack_lower_cwnd_at_tlp = 0;
262 static int32_t rack_limited_retran = 0;
263 static int32_t rack_always_send_oldest = 0;
264 static int32_t rack_tlp_threshold_use = TLP_USE_TWO_ONE;
265 
266 static uint16_t rack_per_of_gp_ss = 250;	/* 250 % slow-start */
267 static uint16_t rack_per_of_gp_ca = 200;	/* 200 % congestion-avoidance */
268 static uint16_t rack_per_of_gp_rec = 200;	/* 200 % of bw */
269 
270 /* Probertt */
271 static uint16_t rack_per_of_gp_probertt = 60;	/* 60% of bw */
272 static uint16_t rack_per_of_gp_lowthresh = 40;	/* 40% is bottom */
273 static uint16_t rack_per_of_gp_probertt_reduce = 10; /* 10% reduction */
274 static uint16_t rack_atexit_prtt_hbp = 130;	/* Clamp to 130% on exit prtt if highly buffered path */
275 static uint16_t rack_atexit_prtt = 130;	/* Clamp to 100% on exit prtt if non highly buffered path */
276 
277 static uint32_t rack_max_drain_wait = 2;	/* How man gp srtt's before we give up draining */
278 static uint32_t rack_must_drain = 1;		/* How many GP srtt's we *must* wait */
279 static uint32_t rack_probertt_use_min_rtt_entry = 1;	/* Use the min to calculate the goal else gp_srtt */
280 static uint32_t rack_probertt_use_min_rtt_exit = 0;
281 static uint32_t rack_probe_rtt_sets_cwnd = 0;
282 static uint32_t rack_probe_rtt_safety_val = 2000000;	/* No more than 2 sec in probe-rtt */
283 static uint32_t rack_time_between_probertt = 9600000;	/* 9.6 sec in usecs */
284 static uint32_t rack_probertt_gpsrtt_cnt_mul = 0;	/* How many srtt periods does probe-rtt last top fraction */
285 static uint32_t rack_probertt_gpsrtt_cnt_div = 0;	/* How many srtt periods does probe-rtt last bottom fraction */
286 static uint32_t rack_min_probertt_hold = 40000;		/* Equal to delayed ack time */
287 static uint32_t rack_probertt_filter_life = 10000000;
288 static uint32_t rack_probertt_lower_within = 10;
289 static uint32_t rack_min_rtt_movement = 250000;	/* Must move at least 250ms (in microseconds)  to count as a lowering */
290 static int32_t rack_pace_one_seg = 0;		/* Shall we pace for less than 1.4Meg 1MSS at a time */
291 static int32_t rack_probertt_clear_is = 1;
292 static int32_t rack_max_drain_hbp = 1;		/* Extra drain times gpsrtt for highly buffered paths */
293 static int32_t rack_hbp_thresh = 3;		/* what is the divisor max_rtt/min_rtt to decided a hbp */
294 
295 /* Part of pacing */
296 static int32_t rack_max_per_above = 30;		/* When we go to increment stop if above 100+this% */
297 
298 /* Timely information */
299 /* Combine these two gives the range of 'no change' to bw */
300 /* ie the up/down provide the upper and lower bound */
301 static int32_t rack_gp_per_bw_mul_up = 2;	/* 2% */
302 static int32_t rack_gp_per_bw_mul_down = 4;	/* 4% */
303 static int32_t rack_gp_rtt_maxmul = 3;		/* 3 x maxmin */
304 static int32_t rack_gp_rtt_minmul = 1;		/* minrtt + (minrtt/mindiv) is lower rtt */
305 static int32_t rack_gp_rtt_mindiv = 4;		/* minrtt + (minrtt * minmul/mindiv) is lower rtt */
306 static int32_t rack_gp_decrease_per = 20;	/* 20% decrease in multipler */
307 static int32_t rack_gp_increase_per = 2;	/* 2% increase in multipler */
308 static int32_t rack_per_lower_bound = 50;	/* Don't allow to drop below this multiplier */
309 static int32_t rack_per_upper_bound_ss = 0;	/* Don't allow SS to grow above this */
310 static int32_t rack_per_upper_bound_ca = 0;	/* Don't allow CA to grow above this */
311 static int32_t rack_do_dyn_mul = 0;		/* Are the rack gp multipliers dynamic */
312 static int32_t rack_gp_no_rec_chg = 1;		/* Prohibit recovery from reducing it's multiplier */
313 static int32_t rack_timely_dec_clear = 6;	/* Do we clear decrement count at a value (6)? */
314 static int32_t rack_timely_max_push_rise = 3;	/* One round of pushing */
315 static int32_t rack_timely_max_push_drop = 3;	/* Three round of pushing */
316 static int32_t rack_timely_min_segs = 4;	/* 4 segment minimum */
317 static int32_t rack_use_max_for_nobackoff = 0;
318 static int32_t rack_timely_int_timely_only = 0;	/* do interim timely's only use the timely algo (no b/w changes)? */
319 static int32_t rack_timely_no_stopping = 0;
320 static int32_t rack_down_raise_thresh = 100;
321 static int32_t rack_req_segs = 1;
322 static uint64_t rack_bw_rate_cap = 0;
323 
324 /* Weird delayed ack mode */
325 static int32_t rack_use_imac_dack = 0;
326 /* Rack specific counters */
327 counter_u64_t rack_badfr;
328 counter_u64_t rack_badfr_bytes;
329 counter_u64_t rack_rtm_prr_retran;
330 counter_u64_t rack_rtm_prr_newdata;
331 counter_u64_t rack_timestamp_mismatch;
332 counter_u64_t rack_reorder_seen;
333 counter_u64_t rack_paced_segments;
334 counter_u64_t rack_unpaced_segments;
335 counter_u64_t rack_calc_zero;
336 counter_u64_t rack_calc_nonzero;
337 counter_u64_t rack_saw_enobuf;
338 counter_u64_t rack_saw_enobuf_hw;
339 counter_u64_t rack_saw_enetunreach;
340 counter_u64_t rack_per_timer_hole;
341 counter_u64_t rack_large_ackcmp;
342 counter_u64_t rack_small_ackcmp;
343 #ifdef INVARIANTS
344 counter_u64_t rack_adjust_map_bw;
345 #endif
346 /* Tail loss probe counters */
347 counter_u64_t rack_tlp_tot;
348 counter_u64_t rack_tlp_newdata;
349 counter_u64_t rack_tlp_retran;
350 counter_u64_t rack_tlp_retran_bytes;
351 counter_u64_t rack_tlp_retran_fail;
352 counter_u64_t rack_to_tot;
353 counter_u64_t rack_to_arm_rack;
354 counter_u64_t rack_to_arm_tlp;
355 counter_u64_t rack_hot_alloc;
356 counter_u64_t rack_to_alloc;
357 counter_u64_t rack_to_alloc_hard;
358 counter_u64_t rack_to_alloc_emerg;
359 counter_u64_t rack_to_alloc_limited;
360 counter_u64_t rack_alloc_limited_conns;
361 counter_u64_t rack_split_limited;
362 
363 #define MAX_NUM_OF_CNTS 13
364 counter_u64_t rack_proc_comp_ack[MAX_NUM_OF_CNTS];
365 counter_u64_t rack_multi_single_eq;
366 counter_u64_t rack_proc_non_comp_ack;
367 
368 counter_u64_t rack_fto_send;
369 counter_u64_t rack_fto_rsm_send;
370 counter_u64_t rack_nfto_resend;
371 counter_u64_t rack_non_fto_send;
372 counter_u64_t rack_extended_rfo;
373 
374 counter_u64_t rack_sack_proc_all;
375 counter_u64_t rack_sack_proc_short;
376 counter_u64_t rack_sack_proc_restart;
377 counter_u64_t rack_sack_attacks_detected;
378 counter_u64_t rack_sack_attacks_reversed;
379 counter_u64_t rack_sack_used_next_merge;
380 counter_u64_t rack_sack_splits;
381 counter_u64_t rack_sack_used_prev_merge;
382 counter_u64_t rack_sack_skipped_acked;
383 counter_u64_t rack_ack_total;
384 counter_u64_t rack_express_sack;
385 counter_u64_t rack_sack_total;
386 counter_u64_t rack_move_none;
387 counter_u64_t rack_move_some;
388 
389 counter_u64_t rack_used_tlpmethod;
390 counter_u64_t rack_used_tlpmethod2;
391 counter_u64_t rack_enter_tlp_calc;
392 counter_u64_t rack_input_idle_reduces;
393 counter_u64_t rack_collapsed_win;
394 counter_u64_t rack_tlp_does_nada;
395 counter_u64_t rack_try_scwnd;
396 counter_u64_t rack_hw_pace_init_fail;
397 counter_u64_t rack_hw_pace_lost;
398 counter_u64_t rack_sbsndptr_right;
399 counter_u64_t rack_sbsndptr_wrong;
400 
401 /* Temp CPU counters */
402 counter_u64_t rack_find_high;
403 
404 counter_u64_t rack_progress_drops;
405 counter_u64_t rack_out_size[TCP_MSS_ACCT_SIZE];
406 counter_u64_t rack_opts_arry[RACK_OPTS_SIZE];
407 
408 
409 #define	RACK_REXMTVAL(tp) max(rack_rto_min, ((tp)->t_srtt + ((tp)->t_rttvar << 2)))
410 
411 #define	RACK_TCPT_RANGESET(tv, value, tvmin, tvmax, slop) do {	\
412 	(tv) = (value) + slop;	 \
413 	if ((u_long)(tv) < (u_long)(tvmin)) \
414 		(tv) = (tvmin); \
415 	if ((u_long)(tv) > (u_long)(tvmax)) \
416 		(tv) = (tvmax); \
417 } while (0)
418 
419 static void
420 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick,  int event, int line);
421 
422 static int
423 rack_process_ack(struct mbuf *m, struct tcphdr *th,
424     struct socket *so, struct tcpcb *tp, struct tcpopt *to,
425     uint32_t tiwin, int32_t tlen, int32_t * ofia, int32_t thflags, int32_t * ret_val);
426 static int
427 rack_process_data(struct mbuf *m, struct tcphdr *th,
428     struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
429     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt);
430 static void
431 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack,
432    uint32_t th_ack, uint16_t nsegs, uint16_t type, int32_t recovery);
433 static struct rack_sendmap *rack_alloc(struct tcp_rack *rack);
434 static struct rack_sendmap *rack_alloc_limit(struct tcp_rack *rack,
435     uint8_t limit_type);
436 static struct rack_sendmap *
437 rack_check_recovery_mode(struct tcpcb *tp,
438     uint32_t tsused);
439 static void
440 rack_cong_signal(struct tcpcb *tp,
441 		 uint32_t type, uint32_t ack);
442 static void rack_counter_destroy(void);
443 static int
444 rack_ctloutput(struct socket *so, struct sockopt *sopt,
445     struct inpcb *inp, struct tcpcb *tp);
446 static int32_t rack_ctor(void *mem, int32_t size, void *arg, int32_t how);
447 static void
448 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line, uint64_t *fill_override);
449 static void
450 rack_do_segment(struct mbuf *m, struct tcphdr *th,
451     struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
452     uint8_t iptos);
453 static void rack_dtor(void *mem, int32_t size, void *arg);
454 static void
455 rack_log_alt_to_to_cancel(struct tcp_rack *rack,
456     uint32_t flex1, uint32_t flex2,
457     uint32_t flex3, uint32_t flex4,
458     uint32_t flex5, uint32_t flex6,
459     uint16_t flex7, uint8_t mod);
460 static void
461 rack_log_pacing_delay_calc(struct tcp_rack *rack, uint32_t len, uint32_t slot,
462    uint64_t bw_est, uint64_t bw, uint64_t len_time, int method, int line, struct rack_sendmap *rsm);
463 static struct rack_sendmap *
464 rack_find_high_nonack(struct tcp_rack *rack,
465     struct rack_sendmap *rsm);
466 static struct rack_sendmap *rack_find_lowest_rsm(struct tcp_rack *rack);
467 static void rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm);
468 static void rack_fini(struct tcpcb *tp, int32_t tcb_is_purged);
469 static int
470 rack_get_sockopt(struct socket *so, struct sockopt *sopt,
471     struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack);
472 static void
473 rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
474 			    tcp_seq th_ack, int line);
475 static uint32_t
476 rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss);
477 static int32_t rack_handoff_ok(struct tcpcb *tp);
478 static int32_t rack_init(struct tcpcb *tp);
479 static void rack_init_sysctls(void);
480 static void
481 rack_log_ack(struct tcpcb *tp, struct tcpopt *to,
482     struct tcphdr *th, int entered_rec, int dup_ack_struck);
483 static void
484 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
485     uint32_t seq_out, uint8_t th_flags, int32_t err, uint64_t ts,
486     struct rack_sendmap *hintrsm, uint16_t add_flags, struct mbuf *s_mb, uint32_t s_moff);
487 
488 static void
489 rack_log_sack_passed(struct tcpcb *tp, struct tcp_rack *rack,
490     struct rack_sendmap *rsm);
491 static void rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm);
492 static int32_t rack_output(struct tcpcb *tp);
493 
494 static uint32_t
495 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack,
496     struct sackblk *sack, struct tcpopt *to, struct rack_sendmap **prsm,
497     uint32_t cts, int *moved_two);
498 static void rack_post_recovery(struct tcpcb *tp, uint32_t th_seq);
499 static void rack_remxt_tmr(struct tcpcb *tp);
500 static int
501 rack_set_sockopt(struct socket *so, struct sockopt *sopt,
502     struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack);
503 static void rack_set_state(struct tcpcb *tp, struct tcp_rack *rack);
504 static int32_t rack_stopall(struct tcpcb *tp);
505 static void
506 rack_timer_activate(struct tcpcb *tp, uint32_t timer_type,
507     uint32_t delta);
508 static int32_t rack_timer_active(struct tcpcb *tp, uint32_t timer_type);
509 static void rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line);
510 static void rack_timer_stop(struct tcpcb *tp, uint32_t timer_type);
511 static uint32_t
512 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
513     struct rack_sendmap *rsm, uint64_t ts, int32_t * lenp, uint16_t add_flag);
514 static void
515 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
516     struct rack_sendmap *rsm, uint64_t ts, uint16_t add_flag);
517 static int
518 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
519     struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack);
520 static int32_t tcp_addrack(module_t mod, int32_t type, void *data);
521 static int
522 rack_do_close_wait(struct mbuf *m, struct tcphdr *th,
523     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
524     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
525 static int
526 rack_do_closing(struct mbuf *m, struct tcphdr *th,
527     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
528     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
529 static int
530 rack_do_established(struct mbuf *m, struct tcphdr *th,
531     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
532     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
533 static int
534 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th,
535     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
536     int32_t tlen, uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos);
537 static int
538 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th,
539     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
540     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
541 static int
542 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th,
543     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
544     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
545 static int
546 rack_do_lastack(struct mbuf *m, struct tcphdr *th,
547     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
548     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
549 static int
550 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th,
551     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
552     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
553 static int
554 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th,
555     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
556     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
557 struct rack_sendmap *
558 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack,
559     uint32_t tsused);
560 static void tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt,
561     uint32_t len, uint32_t us_tim, int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt);
562 static void
563      tcp_rack_partialack(struct tcpcb *tp);
564 static int
565 rack_set_profile(struct tcp_rack *rack, int prof);
566 static void
567 rack_apply_deferred_options(struct tcp_rack *rack);
568 
569 int32_t rack_clear_counter=0;
570 
571 static void
572 rack_set_cc_pacing(struct tcp_rack *rack)
573 {
574 	struct sockopt sopt;
575 	struct cc_newreno_opts opt;
576 	struct newreno old, *ptr;
577 	struct tcpcb *tp;
578 	int error;
579 
580 	if (rack->rc_pacing_cc_set)
581 		return;
582 
583 	tp = rack->rc_tp;
584 	if (tp->cc_algo == NULL) {
585 		/* Tcb is leaving */
586 		printf("No cc algorithm?\n");
587 		return;
588 	}
589 	rack->rc_pacing_cc_set = 1;
590 	if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0) {
591 		/* Not new-reno we can't play games with beta! */
592 		goto out;
593 	}
594 	ptr = ((struct newreno *)tp->ccv->cc_data);
595 	if (CC_ALGO(tp)->ctl_output == NULL)  {
596 		/* Huh, why does new_reno no longer have a set function? */
597 		printf("no ctl_output for algo:%s\n", tp->cc_algo->name);
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->ccv, &sopt, &opt);
615 	if (error)  {
616 		printf("Error returned by ctl_output %d\n", error);
617 		goto out;
618 	}
619 	/*
620 	 * Hack alert we need to set in our newreno_flags
621 	 * so that Abe behavior is also applied.
622 	 */
623 	((struct newreno *)tp->ccv->cc_data)->newreno_flags = CC_NEWRENO_BETA_ECN;
624 	opt.name = CC_NEWRENO_BETA_ECN;
625 	opt.val = rack->r_ctl.rc_saved_beta.beta_ecn;
626 	error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
627 	if (error) {
628 		printf("Error returned by ctl_output %d\n", error);
629 		goto out;
630 	}
631 	/* Save off the original values for restoral */
632 	memcpy(&rack->r_ctl.rc_saved_beta, &old, sizeof(struct newreno));
633 out:
634 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
635 		union tcp_log_stackspecific log;
636 		struct timeval tv;
637 
638 		ptr = ((struct newreno *)tp->ccv->cc_data);
639 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
640 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
641 		if (ptr) {
642 			log.u_bbr.flex1 = ptr->beta;
643 			log.u_bbr.flex2 = ptr->beta_ecn;
644 			log.u_bbr.flex3 = ptr->newreno_flags;
645 		}
646 		log.u_bbr.flex4 = rack->r_ctl.rc_saved_beta.beta;
647 		log.u_bbr.flex5 = rack->r_ctl.rc_saved_beta.beta_ecn;
648 		log.u_bbr.flex6 = rack->r_ctl.rc_saved_beta.newreno_flags;
649 		log.u_bbr.flex7 = rack->gp_ready;
650 		log.u_bbr.flex7 <<= 1;
651 		log.u_bbr.flex7 |= rack->use_fixed_rate;
652 		log.u_bbr.flex7 <<= 1;
653 		log.u_bbr.flex7 |= rack->rc_pacing_cc_set;
654 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
655 		log.u_bbr.flex8 = 3;
656 		tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, error,
657 			       0, &log, false, NULL, NULL, 0, &tv);
658 	}
659 }
660 
661 static void
662 rack_undo_cc_pacing(struct tcp_rack *rack)
663 {
664 	struct newreno old, *ptr;
665 	struct tcpcb *tp;
666 
667 	if (rack->rc_pacing_cc_set == 0)
668 		return;
669 	tp = rack->rc_tp;
670 	rack->rc_pacing_cc_set = 0;
671 	if (tp->cc_algo == NULL)
672 		/* Tcb is leaving */
673 		return;
674 	if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0) {
675 		/* Not new-reno nothing to do! */
676 		return;
677 	}
678 	ptr = ((struct newreno *)tp->ccv->cc_data);
679 	if (ptr == NULL) {
680 		/*
681 		 * This happens at rack_fini() if the
682 		 * cc module gets freed on us. In that
683 		 * case we loose our "new" settings but
684 		 * thats ok, since the tcb is going away anyway.
685 		 */
686 		return;
687 	}
688 	/* Grab out our set values */
689 	memcpy(&old, ptr, sizeof(struct newreno));
690 	/* Copy back in the original values */
691 	memcpy(ptr, &rack->r_ctl.rc_saved_beta, sizeof(struct newreno));
692 	/* Now save back the values we had set in (for when pacing is restored) */
693 	memcpy(&rack->r_ctl.rc_saved_beta, &old, sizeof(struct newreno));
694 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
695 		union tcp_log_stackspecific log;
696 		struct timeval tv;
697 
698 		ptr = ((struct newreno *)tp->ccv->cc_data);
699 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
700 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
701 		log.u_bbr.flex1 = ptr->beta;
702 		log.u_bbr.flex2 = ptr->beta_ecn;
703 		log.u_bbr.flex3 = ptr->newreno_flags;
704 		log.u_bbr.flex4 = rack->r_ctl.rc_saved_beta.beta;
705 		log.u_bbr.flex5 = rack->r_ctl.rc_saved_beta.beta_ecn;
706 		log.u_bbr.flex6 = rack->r_ctl.rc_saved_beta.newreno_flags;
707 		log.u_bbr.flex7 = rack->gp_ready;
708 		log.u_bbr.flex7 <<= 1;
709 		log.u_bbr.flex7 |= rack->use_fixed_rate;
710 		log.u_bbr.flex7 <<= 1;
711 		log.u_bbr.flex7 |= rack->rc_pacing_cc_set;
712 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
713 		log.u_bbr.flex8 = 4;
714 		tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
715 			       0, &log, false, NULL, NULL, 0, &tv);
716 	}
717 }
718 
719 #ifdef NETFLIX_PEAKRATE
720 static inline void
721 rack_update_peakrate_thr(struct tcpcb *tp)
722 {
723 	/* Keep in mind that t_maxpeakrate is in B/s. */
724 	uint64_t peak;
725 	peak = uqmax((tp->t_maxseg * 2),
726 		     (((uint64_t)tp->t_maxpeakrate * (uint64_t)(tp->t_srtt)) / (uint64_t)HPTS_USEC_IN_SEC));
727 	tp->t_peakrate_thr = (uint32_t)uqmin(peak, UINT32_MAX);
728 }
729 #endif
730 
731 static int
732 sysctl_rack_clear(SYSCTL_HANDLER_ARGS)
733 {
734 	uint32_t stat;
735 	int32_t error;
736 	int i;
737 
738 	error = SYSCTL_OUT(req, &rack_clear_counter, sizeof(uint32_t));
739 	if (error || req->newptr == NULL)
740 		return error;
741 
742 	error = SYSCTL_IN(req, &stat, sizeof(uint32_t));
743 	if (error)
744 		return (error);
745 	if (stat == 1) {
746 #ifdef INVARIANTS
747 		printf("Clearing RACK counters\n");
748 #endif
749 		counter_u64_zero(rack_badfr);
750 		counter_u64_zero(rack_badfr_bytes);
751 		counter_u64_zero(rack_rtm_prr_retran);
752 		counter_u64_zero(rack_rtm_prr_newdata);
753 		counter_u64_zero(rack_timestamp_mismatch);
754 		counter_u64_zero(rack_reorder_seen);
755 		counter_u64_zero(rack_tlp_tot);
756 		counter_u64_zero(rack_tlp_newdata);
757 		counter_u64_zero(rack_tlp_retran);
758 		counter_u64_zero(rack_tlp_retran_bytes);
759 		counter_u64_zero(rack_tlp_retran_fail);
760 		counter_u64_zero(rack_to_tot);
761 		counter_u64_zero(rack_to_arm_rack);
762 		counter_u64_zero(rack_to_arm_tlp);
763 		counter_u64_zero(rack_paced_segments);
764 		counter_u64_zero(rack_calc_zero);
765 		counter_u64_zero(rack_calc_nonzero);
766 		counter_u64_zero(rack_unpaced_segments);
767 		counter_u64_zero(rack_saw_enobuf);
768 		counter_u64_zero(rack_saw_enobuf_hw);
769 		counter_u64_zero(rack_saw_enetunreach);
770 		counter_u64_zero(rack_per_timer_hole);
771 		counter_u64_zero(rack_large_ackcmp);
772 		counter_u64_zero(rack_small_ackcmp);
773 #ifdef INVARIANTS
774 		counter_u64_zero(rack_adjust_map_bw);
775 #endif
776 		counter_u64_zero(rack_to_alloc_hard);
777 		counter_u64_zero(rack_to_alloc_emerg);
778 		counter_u64_zero(rack_sack_proc_all);
779 		counter_u64_zero(rack_fto_send);
780 		counter_u64_zero(rack_fto_rsm_send);
781 		counter_u64_zero(rack_extended_rfo);
782 		counter_u64_zero(rack_hw_pace_init_fail);
783 		counter_u64_zero(rack_hw_pace_lost);
784 		counter_u64_zero(rack_sbsndptr_wrong);
785 		counter_u64_zero(rack_sbsndptr_right);
786 		counter_u64_zero(rack_non_fto_send);
787 		counter_u64_zero(rack_nfto_resend);
788 		counter_u64_zero(rack_sack_proc_short);
789 		counter_u64_zero(rack_sack_proc_restart);
790 		counter_u64_zero(rack_to_alloc);
791 		counter_u64_zero(rack_to_alloc_limited);
792 		counter_u64_zero(rack_alloc_limited_conns);
793 		counter_u64_zero(rack_split_limited);
794 		for (i = 0; i < MAX_NUM_OF_CNTS; i++) {
795 			counter_u64_zero(rack_proc_comp_ack[i]);
796 		}
797 		counter_u64_zero(rack_multi_single_eq);
798 		counter_u64_zero(rack_proc_non_comp_ack);
799 		counter_u64_zero(rack_find_high);
800 		counter_u64_zero(rack_sack_attacks_detected);
801 		counter_u64_zero(rack_sack_attacks_reversed);
802 		counter_u64_zero(rack_sack_used_next_merge);
803 		counter_u64_zero(rack_sack_used_prev_merge);
804 		counter_u64_zero(rack_sack_splits);
805 		counter_u64_zero(rack_sack_skipped_acked);
806 		counter_u64_zero(rack_ack_total);
807 		counter_u64_zero(rack_express_sack);
808 		counter_u64_zero(rack_sack_total);
809 		counter_u64_zero(rack_move_none);
810 		counter_u64_zero(rack_move_some);
811 		counter_u64_zero(rack_used_tlpmethod);
812 		counter_u64_zero(rack_used_tlpmethod2);
813 		counter_u64_zero(rack_enter_tlp_calc);
814 		counter_u64_zero(rack_progress_drops);
815 		counter_u64_zero(rack_tlp_does_nada);
816 		counter_u64_zero(rack_try_scwnd);
817 		counter_u64_zero(rack_collapsed_win);
818 	}
819 	rack_clear_counter = 0;
820 	return (0);
821 }
822 
823 static void
824 rack_init_sysctls(void)
825 {
826 	int i;
827 	struct sysctl_oid *rack_counters;
828 	struct sysctl_oid *rack_attack;
829 	struct sysctl_oid *rack_pacing;
830 	struct sysctl_oid *rack_timely;
831 	struct sysctl_oid *rack_timers;
832 	struct sysctl_oid *rack_tlp;
833 	struct sysctl_oid *rack_misc;
834 	struct sysctl_oid *rack_measure;
835 	struct sysctl_oid *rack_probertt;
836 	struct sysctl_oid *rack_hw_pacing;
837 
838 	rack_attack = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
839 	    SYSCTL_CHILDREN(rack_sysctl_root),
840 	    OID_AUTO,
841 	    "sack_attack",
842 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
843 	    "Rack Sack Attack Counters and Controls");
844 	rack_counters = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
845 	    SYSCTL_CHILDREN(rack_sysctl_root),
846 	    OID_AUTO,
847 	    "stats",
848 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
849 	    "Rack Counters");
850 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
851 	    SYSCTL_CHILDREN(rack_sysctl_root),
852 	    OID_AUTO, "rate_sample_method", CTLFLAG_RW,
853 	    &rack_rate_sample_method , USE_RTT_LOW,
854 	    "What method should we use for rate sampling 0=high, 1=low ");
855 	/* Probe rtt related controls */
856 	rack_probertt = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
857 	    SYSCTL_CHILDREN(rack_sysctl_root),
858 	    OID_AUTO,
859 	    "probertt",
860 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
861 	    "ProbeRTT related Controls");
862 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
863 	    SYSCTL_CHILDREN(rack_probertt),
864 	    OID_AUTO, "exit_per_hpb", CTLFLAG_RW,
865 	    &rack_atexit_prtt_hbp, 130,
866 	    "What percentage above goodput do we clamp CA/SS to at exit on high-BDP path 110%");
867 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
868 	    SYSCTL_CHILDREN(rack_probertt),
869 	    OID_AUTO, "exit_per_nonhpb", CTLFLAG_RW,
870 	    &rack_atexit_prtt, 130,
871 	    "What percentage above goodput do we clamp CA/SS to at exit on a non high-BDP path 100%");
872 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
873 	    SYSCTL_CHILDREN(rack_probertt),
874 	    OID_AUTO, "gp_per_mul", CTLFLAG_RW,
875 	    &rack_per_of_gp_probertt, 60,
876 	    "What percentage of goodput do we pace at in probertt");
877 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
878 	    SYSCTL_CHILDREN(rack_probertt),
879 	    OID_AUTO, "gp_per_reduce", CTLFLAG_RW,
880 	    &rack_per_of_gp_probertt_reduce, 10,
881 	    "What percentage of goodput do we reduce every gp_srtt");
882 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
883 	    SYSCTL_CHILDREN(rack_probertt),
884 	    OID_AUTO, "gp_per_low", CTLFLAG_RW,
885 	    &rack_per_of_gp_lowthresh, 40,
886 	    "What percentage of goodput do we allow the multiplier to fall to");
887 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
888 	    SYSCTL_CHILDREN(rack_probertt),
889 	    OID_AUTO, "time_between", CTLFLAG_RW,
890 	    & rack_time_between_probertt, 96000000,
891 	    "How many useconds between the lowest rtt falling must past before we enter probertt");
892 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
893 	    SYSCTL_CHILDREN(rack_probertt),
894 	    OID_AUTO, "safety", CTLFLAG_RW,
895 	    &rack_probe_rtt_safety_val, 2000000,
896 	    "If not zero, provides a maximum usecond that you can stay in probertt (2sec = 2000000)");
897 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
898 	    SYSCTL_CHILDREN(rack_probertt),
899 	    OID_AUTO, "sets_cwnd", CTLFLAG_RW,
900 	    &rack_probe_rtt_sets_cwnd, 0,
901 	    "Do we set the cwnd too (if always_lower is on)");
902 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
903 	    SYSCTL_CHILDREN(rack_probertt),
904 	    OID_AUTO, "maxdrainsrtts", CTLFLAG_RW,
905 	    &rack_max_drain_wait, 2,
906 	    "Maximum number of gp_srtt's to hold in drain waiting for flight to reach goal");
907 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
908 	    SYSCTL_CHILDREN(rack_probertt),
909 	    OID_AUTO, "mustdrainsrtts", CTLFLAG_RW,
910 	    &rack_must_drain, 1,
911 	    "We must drain this many gp_srtt's waiting for flight to reach goal");
912 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
913 	    SYSCTL_CHILDREN(rack_probertt),
914 	    OID_AUTO, "goal_use_min_entry", CTLFLAG_RW,
915 	    &rack_probertt_use_min_rtt_entry, 1,
916 	    "Should we use the min-rtt to calculate the goal rtt (else gp_srtt) at entry");
917 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
918 	    SYSCTL_CHILDREN(rack_probertt),
919 	    OID_AUTO, "goal_use_min_exit", CTLFLAG_RW,
920 	    &rack_probertt_use_min_rtt_exit, 0,
921 	    "How to set cwnd at exit, 0 - dynamic, 1 - use min-rtt, 2 - use curgprtt, 3 - entry gp-rtt");
922 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
923 	    SYSCTL_CHILDREN(rack_probertt),
924 	    OID_AUTO, "length_div", CTLFLAG_RW,
925 	    &rack_probertt_gpsrtt_cnt_div, 0,
926 	    "How many recent goodput srtt periods plus hold tim does probertt last (bottom of fraction)");
927 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
928 	    SYSCTL_CHILDREN(rack_probertt),
929 	    OID_AUTO, "length_mul", CTLFLAG_RW,
930 	    &rack_probertt_gpsrtt_cnt_mul, 0,
931 	    "How many recent goodput srtt periods plus hold tim does probertt last (top of fraction)");
932 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
933 	    SYSCTL_CHILDREN(rack_probertt),
934 	    OID_AUTO, "holdtim_at_target", CTLFLAG_RW,
935 	    &rack_min_probertt_hold, 200000,
936 	    "What is the minimum time we hold probertt at target");
937 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
938 	    SYSCTL_CHILDREN(rack_probertt),
939 	    OID_AUTO, "filter_life", CTLFLAG_RW,
940 	    &rack_probertt_filter_life, 10000000,
941 	    "What is the time for the filters life in useconds");
942 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
943 	    SYSCTL_CHILDREN(rack_probertt),
944 	    OID_AUTO, "lower_within", CTLFLAG_RW,
945 	    &rack_probertt_lower_within, 10,
946 	    "If the rtt goes lower within this percentage of the time, go into probe-rtt");
947 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
948 	    SYSCTL_CHILDREN(rack_probertt),
949 	    OID_AUTO, "must_move", CTLFLAG_RW,
950 	    &rack_min_rtt_movement, 250,
951 	    "How much is the minimum movement in rtt to count as a drop for probertt purposes");
952 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
953 	    SYSCTL_CHILDREN(rack_probertt),
954 	    OID_AUTO, "clear_is_cnts", CTLFLAG_RW,
955 	    &rack_probertt_clear_is, 1,
956 	    "Do we clear I/S counts on exiting probe-rtt");
957 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
958 	    SYSCTL_CHILDREN(rack_probertt),
959 	    OID_AUTO, "hbp_extra_drain", CTLFLAG_RW,
960 	    &rack_max_drain_hbp, 1,
961 	    "How many extra drain gpsrtt's do we get in highly buffered paths");
962 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
963 	    SYSCTL_CHILDREN(rack_probertt),
964 	    OID_AUTO, "hbp_threshold", CTLFLAG_RW,
965 	    &rack_hbp_thresh, 3,
966 	    "We are highly buffered if min_rtt_seen / max_rtt_seen > this-threshold");
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 multipler 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 higest 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 higest 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 	    "Maxiumum 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 	/* Misc rack controls */
1362 	rack_misc = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1363 	    SYSCTL_CHILDREN(rack_sysctl_root),
1364 	    OID_AUTO,
1365 	    "misc",
1366 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1367 	    "Misc related controls");
1368 #ifdef TCP_ACCOUNTING
1369 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1370 	    SYSCTL_CHILDREN(rack_misc),
1371 	    OID_AUTO, "tcp_acct", CTLFLAG_RW,
1372 	    &rack_tcp_accounting, 0,
1373 	    "Should we turn on TCP accounting for all rack sessions?");
1374 #endif
1375 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1376 	    SYSCTL_CHILDREN(rack_misc),
1377 	    OID_AUTO, "prr_addback_max", CTLFLAG_RW,
1378 	    &rack_prr_addbackmax, 2,
1379 	    "What is the maximum number of MSS we allow to be added back if prr can't send all its data?");
1380 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1381 	    SYSCTL_CHILDREN(rack_misc),
1382 	    OID_AUTO, "stats_gets_ms", CTLFLAG_RW,
1383 	    &rack_stats_gets_ms_rtt, 1,
1384 	    "What do we feed the stats framework (1 = ms_rtt, 0 = us_rtt, 2 = ms_rtt from hdwr, > 2 usec rtt from hdwr)?");
1385 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1386 	    SYSCTL_CHILDREN(rack_misc),
1387 	    OID_AUTO, "clientlowbuf", CTLFLAG_RW,
1388 	    &rack_client_low_buf, 0,
1389 	    "Client low buffer level (below this we are more aggressive in DGP exiting recovery (0 = off)?");
1390 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1391 	    SYSCTL_CHILDREN(rack_misc),
1392 	    OID_AUTO, "defprofile", CTLFLAG_RW,
1393 	    &rack_def_profile, 0,
1394 	    "Should RACK use a default profile (0=no, num == profile num)?");
1395 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1396 	    SYSCTL_CHILDREN(rack_misc),
1397 	    OID_AUTO, "cmpack", CTLFLAG_RW,
1398 	    &rack_use_cmp_acks, 1,
1399 	    "Should RACK have LRO send compressed acks");
1400 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1401 	    SYSCTL_CHILDREN(rack_misc),
1402 	    OID_AUTO, "fsb", CTLFLAG_RW,
1403 	    &rack_use_fsb, 1,
1404 	    "Should RACK use the fast send block?");
1405 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1406 	    SYSCTL_CHILDREN(rack_misc),
1407 	    OID_AUTO, "rfo", CTLFLAG_RW,
1408 	    &rack_use_rfo, 1,
1409 	    "Should RACK use rack_fast_output()?");
1410 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1411 	    SYSCTL_CHILDREN(rack_misc),
1412 	    OID_AUTO, "rsmrfo", CTLFLAG_RW,
1413 	    &rack_use_rsm_rfo, 1,
1414 	    "Should RACK use rack_fast_rsm_output()?");
1415 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1416 	    SYSCTL_CHILDREN(rack_misc),
1417 	    OID_AUTO, "shared_cwnd", CTLFLAG_RW,
1418 	    &rack_enable_shared_cwnd, 1,
1419 	    "Should RACK try to use the shared cwnd on connections where allowed");
1420 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1421 	    SYSCTL_CHILDREN(rack_misc),
1422 	    OID_AUTO, "limits_on_scwnd", CTLFLAG_RW,
1423 	    &rack_limits_scwnd, 1,
1424 	    "Should RACK place low end time limits on the shared cwnd feature");
1425 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1426 	    SYSCTL_CHILDREN(rack_misc),
1427 	    OID_AUTO, "non_paced_lro_queue", CTLFLAG_RW,
1428 	    &rack_enable_mqueue_for_nonpaced, 0,
1429 	    "Should RACK use mbuf queuing for non-paced connections");
1430 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1431 	    SYSCTL_CHILDREN(rack_misc),
1432 	    OID_AUTO, "iMac_dack", CTLFLAG_RW,
1433 	    &rack_use_imac_dack, 0,
1434 	    "Should RACK try to emulate iMac delayed ack");
1435 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1436 	    SYSCTL_CHILDREN(rack_misc),
1437 	    OID_AUTO, "no_prr", CTLFLAG_RW,
1438 	    &rack_disable_prr, 0,
1439 	    "Should RACK not use prr and only pace (must have pacing on)");
1440 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1441 	    SYSCTL_CHILDREN(rack_misc),
1442 	    OID_AUTO, "bb_verbose", CTLFLAG_RW,
1443 	    &rack_verbose_logging, 0,
1444 	    "Should RACK black box logging be verbose");
1445 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1446 	    SYSCTL_CHILDREN(rack_misc),
1447 	    OID_AUTO, "data_after_close", CTLFLAG_RW,
1448 	    &rack_ignore_data_after_close, 1,
1449 	    "Do we hold off sending a RST until all pending data is ack'd");
1450 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1451 	    SYSCTL_CHILDREN(rack_misc),
1452 	    OID_AUTO, "no_sack_needed", CTLFLAG_RW,
1453 	    &rack_sack_not_required, 1,
1454 	    "Do we allow rack to run on connections not supporting SACK");
1455 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1456 	    SYSCTL_CHILDREN(rack_misc),
1457 	    OID_AUTO, "prr_sendalot", CTLFLAG_RW,
1458 	    &rack_send_a_lot_in_prr, 1,
1459 	    "Send a lot in prr");
1460 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1461 	    SYSCTL_CHILDREN(rack_misc),
1462 	    OID_AUTO, "autoscale", CTLFLAG_RW,
1463 	    &rack_autosndbuf_inc, 20,
1464 	    "What percentage should rack scale up its snd buffer by?");
1465 	/* Sack Attacker detection stuff */
1466 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1467 	    SYSCTL_CHILDREN(rack_attack),
1468 	    OID_AUTO, "detect_highsackratio", CTLFLAG_RW,
1469 	    &rack_highest_sack_thresh_seen, 0,
1470 	    "Highest sack to ack ratio seen");
1471 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1472 	    SYSCTL_CHILDREN(rack_attack),
1473 	    OID_AUTO, "detect_highmoveratio", CTLFLAG_RW,
1474 	    &rack_highest_move_thresh_seen, 0,
1475 	    "Highest move to non-move ratio seen");
1476 	rack_ack_total = counter_u64_alloc(M_WAITOK);
1477 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1478 	    SYSCTL_CHILDREN(rack_attack),
1479 	    OID_AUTO, "acktotal", CTLFLAG_RD,
1480 	    &rack_ack_total,
1481 	    "Total number of Ack's");
1482 	rack_express_sack = counter_u64_alloc(M_WAITOK);
1483 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1484 	    SYSCTL_CHILDREN(rack_attack),
1485 	    OID_AUTO, "exp_sacktotal", CTLFLAG_RD,
1486 	    &rack_express_sack,
1487 	    "Total expresss number of Sack's");
1488 	rack_sack_total = counter_u64_alloc(M_WAITOK);
1489 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1490 	    SYSCTL_CHILDREN(rack_attack),
1491 	    OID_AUTO, "sacktotal", CTLFLAG_RD,
1492 	    &rack_sack_total,
1493 	    "Total number of SACKs");
1494 	rack_move_none = counter_u64_alloc(M_WAITOK);
1495 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1496 	    SYSCTL_CHILDREN(rack_attack),
1497 	    OID_AUTO, "move_none", CTLFLAG_RD,
1498 	    &rack_move_none,
1499 	    "Total number of SACK index reuse of postions under threshold");
1500 	rack_move_some = counter_u64_alloc(M_WAITOK);
1501 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1502 	    SYSCTL_CHILDREN(rack_attack),
1503 	    OID_AUTO, "move_some", CTLFLAG_RD,
1504 	    &rack_move_some,
1505 	    "Total number of SACK index reuse of postions over threshold");
1506 	rack_sack_attacks_detected = counter_u64_alloc(M_WAITOK);
1507 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1508 	    SYSCTL_CHILDREN(rack_attack),
1509 	    OID_AUTO, "attacks", CTLFLAG_RD,
1510 	    &rack_sack_attacks_detected,
1511 	    "Total number of SACK attackers that had sack disabled");
1512 	rack_sack_attacks_reversed = counter_u64_alloc(M_WAITOK);
1513 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1514 	    SYSCTL_CHILDREN(rack_attack),
1515 	    OID_AUTO, "reversed", CTLFLAG_RD,
1516 	    &rack_sack_attacks_reversed,
1517 	    "Total number of SACK attackers that were later determined false positive");
1518 	rack_sack_used_next_merge = counter_u64_alloc(M_WAITOK);
1519 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1520 	    SYSCTL_CHILDREN(rack_attack),
1521 	    OID_AUTO, "nextmerge", CTLFLAG_RD,
1522 	    &rack_sack_used_next_merge,
1523 	    "Total number of times we used the next merge");
1524 	rack_sack_used_prev_merge = counter_u64_alloc(M_WAITOK);
1525 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1526 	    SYSCTL_CHILDREN(rack_attack),
1527 	    OID_AUTO, "prevmerge", CTLFLAG_RD,
1528 	    &rack_sack_used_prev_merge,
1529 	    "Total number of times we used the prev merge");
1530 	/* Counters */
1531 	rack_fto_send = counter_u64_alloc(M_WAITOK);
1532 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1533 	    SYSCTL_CHILDREN(rack_counters),
1534 	    OID_AUTO, "fto_send", CTLFLAG_RD,
1535 	    &rack_fto_send, "Total number of rack_fast_output sends");
1536 	rack_fto_rsm_send = counter_u64_alloc(M_WAITOK);
1537 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1538 	    SYSCTL_CHILDREN(rack_counters),
1539 	    OID_AUTO, "fto_rsm_send", CTLFLAG_RD,
1540 	    &rack_fto_rsm_send, "Total number of rack_fast_rsm_output sends");
1541 	rack_nfto_resend = counter_u64_alloc(M_WAITOK);
1542 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1543 	    SYSCTL_CHILDREN(rack_counters),
1544 	    OID_AUTO, "nfto_resend", CTLFLAG_RD,
1545 	    &rack_nfto_resend, "Total number of rack_output retransmissions");
1546 	rack_non_fto_send = counter_u64_alloc(M_WAITOK);
1547 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1548 	    SYSCTL_CHILDREN(rack_counters),
1549 	    OID_AUTO, "nfto_send", CTLFLAG_RD,
1550 	    &rack_non_fto_send, "Total number of rack_output first sends");
1551 	rack_extended_rfo = counter_u64_alloc(M_WAITOK);
1552 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1553 	    SYSCTL_CHILDREN(rack_counters),
1554 	    OID_AUTO, "rfo_extended", CTLFLAG_RD,
1555 	    &rack_extended_rfo, "Total number of times we extended rfo");
1556 
1557 	rack_hw_pace_init_fail = counter_u64_alloc(M_WAITOK);
1558 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1559 	    SYSCTL_CHILDREN(rack_counters),
1560 	    OID_AUTO, "hwpace_init_fail", CTLFLAG_RD,
1561 	    &rack_hw_pace_init_fail, "Total number of times we failed to initialize hw pacing");
1562 	rack_hw_pace_lost = counter_u64_alloc(M_WAITOK);
1563 
1564 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1565 	    SYSCTL_CHILDREN(rack_counters),
1566 	    OID_AUTO, "hwpace_lost", CTLFLAG_RD,
1567 	    &rack_hw_pace_lost, "Total number of times we failed to initialize hw pacing");
1568 
1569 
1570 
1571 	rack_badfr = counter_u64_alloc(M_WAITOK);
1572 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1573 	    SYSCTL_CHILDREN(rack_counters),
1574 	    OID_AUTO, "badfr", CTLFLAG_RD,
1575 	    &rack_badfr, "Total number of bad FRs");
1576 	rack_badfr_bytes = counter_u64_alloc(M_WAITOK);
1577 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1578 	    SYSCTL_CHILDREN(rack_counters),
1579 	    OID_AUTO, "badfr_bytes", CTLFLAG_RD,
1580 	    &rack_badfr_bytes, "Total number of bad FRs");
1581 	rack_rtm_prr_retran = counter_u64_alloc(M_WAITOK);
1582 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1583 	    SYSCTL_CHILDREN(rack_counters),
1584 	    OID_AUTO, "prrsndret", CTLFLAG_RD,
1585 	    &rack_rtm_prr_retran,
1586 	    "Total number of prr based retransmits");
1587 	rack_rtm_prr_newdata = counter_u64_alloc(M_WAITOK);
1588 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1589 	    SYSCTL_CHILDREN(rack_counters),
1590 	    OID_AUTO, "prrsndnew", CTLFLAG_RD,
1591 	    &rack_rtm_prr_newdata,
1592 	    "Total number of prr based new transmits");
1593 	rack_timestamp_mismatch = counter_u64_alloc(M_WAITOK);
1594 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1595 	    SYSCTL_CHILDREN(rack_counters),
1596 	    OID_AUTO, "tsnf", CTLFLAG_RD,
1597 	    &rack_timestamp_mismatch,
1598 	    "Total number of timestamps that we could not find the reported ts");
1599 	rack_find_high = counter_u64_alloc(M_WAITOK);
1600 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1601 	    SYSCTL_CHILDREN(rack_counters),
1602 	    OID_AUTO, "findhigh", CTLFLAG_RD,
1603 	    &rack_find_high,
1604 	    "Total number of FIN causing find-high");
1605 	rack_reorder_seen = counter_u64_alloc(M_WAITOK);
1606 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1607 	    SYSCTL_CHILDREN(rack_counters),
1608 	    OID_AUTO, "reordering", CTLFLAG_RD,
1609 	    &rack_reorder_seen,
1610 	    "Total number of times we added delay due to reordering");
1611 	rack_tlp_tot = counter_u64_alloc(M_WAITOK);
1612 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1613 	    SYSCTL_CHILDREN(rack_counters),
1614 	    OID_AUTO, "tlp_to_total", CTLFLAG_RD,
1615 	    &rack_tlp_tot,
1616 	    "Total number of tail loss probe expirations");
1617 	rack_tlp_newdata = counter_u64_alloc(M_WAITOK);
1618 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1619 	    SYSCTL_CHILDREN(rack_counters),
1620 	    OID_AUTO, "tlp_new", CTLFLAG_RD,
1621 	    &rack_tlp_newdata,
1622 	    "Total number of tail loss probe sending new data");
1623 	rack_tlp_retran = counter_u64_alloc(M_WAITOK);
1624 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1625 	    SYSCTL_CHILDREN(rack_counters),
1626 	    OID_AUTO, "tlp_retran", CTLFLAG_RD,
1627 	    &rack_tlp_retran,
1628 	    "Total number of tail loss probe sending retransmitted data");
1629 	rack_tlp_retran_bytes = counter_u64_alloc(M_WAITOK);
1630 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1631 	    SYSCTL_CHILDREN(rack_counters),
1632 	    OID_AUTO, "tlp_retran_bytes", CTLFLAG_RD,
1633 	    &rack_tlp_retran_bytes,
1634 	    "Total bytes of tail loss probe sending retransmitted data");
1635 	rack_tlp_retran_fail = counter_u64_alloc(M_WAITOK);
1636 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1637 	    SYSCTL_CHILDREN(rack_counters),
1638 	    OID_AUTO, "tlp_retran_fail", CTLFLAG_RD,
1639 	    &rack_tlp_retran_fail,
1640 	    "Total number of tail loss probe sending retransmitted data that failed (wait for t3)");
1641 	rack_to_tot = counter_u64_alloc(M_WAITOK);
1642 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1643 	    SYSCTL_CHILDREN(rack_counters),
1644 	    OID_AUTO, "rack_to_tot", CTLFLAG_RD,
1645 	    &rack_to_tot,
1646 	    "Total number of times the rack to expired");
1647 	rack_to_arm_rack = counter_u64_alloc(M_WAITOK);
1648 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1649 	    SYSCTL_CHILDREN(rack_counters),
1650 	    OID_AUTO, "arm_rack", CTLFLAG_RD,
1651 	    &rack_to_arm_rack,
1652 	    "Total number of times the rack timer armed");
1653 	rack_to_arm_tlp = counter_u64_alloc(M_WAITOK);
1654 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1655 	    SYSCTL_CHILDREN(rack_counters),
1656 	    OID_AUTO, "arm_tlp", CTLFLAG_RD,
1657 	    &rack_to_arm_tlp,
1658 	    "Total number of times the tlp timer armed");
1659 	rack_calc_zero = counter_u64_alloc(M_WAITOK);
1660 	rack_calc_nonzero = counter_u64_alloc(M_WAITOK);
1661 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1662 	    SYSCTL_CHILDREN(rack_counters),
1663 	    OID_AUTO, "calc_zero", CTLFLAG_RD,
1664 	    &rack_calc_zero,
1665 	    "Total number of times pacing time worked out to zero");
1666 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1667 	    SYSCTL_CHILDREN(rack_counters),
1668 	    OID_AUTO, "calc_nonzero", CTLFLAG_RD,
1669 	    &rack_calc_nonzero,
1670 	    "Total number of times pacing time worked out to non-zero");
1671 	rack_paced_segments = counter_u64_alloc(M_WAITOK);
1672 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1673 	    SYSCTL_CHILDREN(rack_counters),
1674 	    OID_AUTO, "paced", CTLFLAG_RD,
1675 	    &rack_paced_segments,
1676 	    "Total number of times a segment send caused hptsi");
1677 	rack_unpaced_segments = counter_u64_alloc(M_WAITOK);
1678 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1679 	    SYSCTL_CHILDREN(rack_counters),
1680 	    OID_AUTO, "unpaced", CTLFLAG_RD,
1681 	    &rack_unpaced_segments,
1682 	    "Total number of times a segment did not cause hptsi");
1683 	rack_saw_enobuf = counter_u64_alloc(M_WAITOK);
1684 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1685 	    SYSCTL_CHILDREN(rack_counters),
1686 	    OID_AUTO, "saw_enobufs", CTLFLAG_RD,
1687 	    &rack_saw_enobuf,
1688 	    "Total number of times a sends returned enobuf for non-hdwr paced connections");
1689 	rack_saw_enobuf_hw = counter_u64_alloc(M_WAITOK);
1690 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1691 	    SYSCTL_CHILDREN(rack_counters),
1692 	    OID_AUTO, "saw_enobufs_hw", CTLFLAG_RD,
1693 	    &rack_saw_enobuf_hw,
1694 	    "Total number of times a send returned enobuf for hdwr paced connections");
1695 	rack_saw_enetunreach = counter_u64_alloc(M_WAITOK);
1696 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1697 	    SYSCTL_CHILDREN(rack_counters),
1698 	    OID_AUTO, "saw_enetunreach", CTLFLAG_RD,
1699 	    &rack_saw_enetunreach,
1700 	    "Total number of times a send received a enetunreachable");
1701 	rack_hot_alloc = counter_u64_alloc(M_WAITOK);
1702 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1703 	    SYSCTL_CHILDREN(rack_counters),
1704 	    OID_AUTO, "alloc_hot", CTLFLAG_RD,
1705 	    &rack_hot_alloc,
1706 	    "Total allocations from the top of our list");
1707 	rack_to_alloc = counter_u64_alloc(M_WAITOK);
1708 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1709 	    SYSCTL_CHILDREN(rack_counters),
1710 	    OID_AUTO, "allocs", CTLFLAG_RD,
1711 	    &rack_to_alloc,
1712 	    "Total allocations of tracking structures");
1713 	rack_to_alloc_hard = counter_u64_alloc(M_WAITOK);
1714 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1715 	    SYSCTL_CHILDREN(rack_counters),
1716 	    OID_AUTO, "allochard", CTLFLAG_RD,
1717 	    &rack_to_alloc_hard,
1718 	    "Total allocations done with sleeping the hard way");
1719 	rack_to_alloc_emerg = counter_u64_alloc(M_WAITOK);
1720 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1721 	    SYSCTL_CHILDREN(rack_counters),
1722 	    OID_AUTO, "allocemerg", CTLFLAG_RD,
1723 	    &rack_to_alloc_emerg,
1724 	    "Total allocations done from emergency cache");
1725 	rack_to_alloc_limited = counter_u64_alloc(M_WAITOK);
1726 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1727 	    SYSCTL_CHILDREN(rack_counters),
1728 	    OID_AUTO, "alloc_limited", CTLFLAG_RD,
1729 	    &rack_to_alloc_limited,
1730 	    "Total allocations dropped due to limit");
1731 	rack_alloc_limited_conns = counter_u64_alloc(M_WAITOK);
1732 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1733 	    SYSCTL_CHILDREN(rack_counters),
1734 	    OID_AUTO, "alloc_limited_conns", CTLFLAG_RD,
1735 	    &rack_alloc_limited_conns,
1736 	    "Connections with allocations dropped due to limit");
1737 	rack_split_limited = counter_u64_alloc(M_WAITOK);
1738 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1739 	    SYSCTL_CHILDREN(rack_counters),
1740 	    OID_AUTO, "split_limited", CTLFLAG_RD,
1741 	    &rack_split_limited,
1742 	    "Split allocations dropped due to limit");
1743 
1744 	for (i = 0; i < MAX_NUM_OF_CNTS; i++) {
1745 		char name[32];
1746 		sprintf(name, "cmp_ack_cnt_%d", i);
1747 		rack_proc_comp_ack[i] = counter_u64_alloc(M_WAITOK);
1748 		SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1749 				       SYSCTL_CHILDREN(rack_counters),
1750 				       OID_AUTO, name, CTLFLAG_RD,
1751 				       &rack_proc_comp_ack[i],
1752 				       "Number of compressed acks we processed");
1753 	}
1754 	rack_large_ackcmp = counter_u64_alloc(M_WAITOK);
1755 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1756 	    SYSCTL_CHILDREN(rack_counters),
1757 	    OID_AUTO, "cmp_large_mbufs", CTLFLAG_RD,
1758 	    &rack_large_ackcmp,
1759 	    "Number of TCP connections with large mbuf's for compressed acks");
1760 	rack_small_ackcmp = counter_u64_alloc(M_WAITOK);
1761 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1762 	    SYSCTL_CHILDREN(rack_counters),
1763 	    OID_AUTO, "cmp_small_mbufs", CTLFLAG_RD,
1764 	    &rack_small_ackcmp,
1765 	    "Number of TCP connections with small mbuf's for compressed acks");
1766 #ifdef INVARIANTS
1767 	rack_adjust_map_bw = counter_u64_alloc(M_WAITOK);
1768 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1769 	    SYSCTL_CHILDREN(rack_counters),
1770 	    OID_AUTO, "map_adjust_req", CTLFLAG_RD,
1771 	    &rack_adjust_map_bw,
1772 	    "Number of times we hit the case where the sb went up and down on a sendmap entry");
1773 #endif
1774 	rack_multi_single_eq = counter_u64_alloc(M_WAITOK);
1775 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1776 	    SYSCTL_CHILDREN(rack_counters),
1777 	    OID_AUTO, "cmp_ack_equiv", CTLFLAG_RD,
1778 	    &rack_multi_single_eq,
1779 	    "Number of compressed acks total represented");
1780 	rack_proc_non_comp_ack = counter_u64_alloc(M_WAITOK);
1781 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1782 	    SYSCTL_CHILDREN(rack_counters),
1783 	    OID_AUTO, "cmp_ack_not", CTLFLAG_RD,
1784 	    &rack_proc_non_comp_ack,
1785 	    "Number of non compresseds acks that we processed");
1786 
1787 
1788 	rack_sack_proc_all = counter_u64_alloc(M_WAITOK);
1789 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1790 	    SYSCTL_CHILDREN(rack_counters),
1791 	    OID_AUTO, "sack_long", CTLFLAG_RD,
1792 	    &rack_sack_proc_all,
1793 	    "Total times we had to walk whole list for sack processing");
1794 	rack_sack_proc_restart = counter_u64_alloc(M_WAITOK);
1795 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1796 	    SYSCTL_CHILDREN(rack_counters),
1797 	    OID_AUTO, "sack_restart", CTLFLAG_RD,
1798 	    &rack_sack_proc_restart,
1799 	    "Total times we had to walk whole list due to a restart");
1800 	rack_sack_proc_short = counter_u64_alloc(M_WAITOK);
1801 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1802 	    SYSCTL_CHILDREN(rack_counters),
1803 	    OID_AUTO, "sack_short", CTLFLAG_RD,
1804 	    &rack_sack_proc_short,
1805 	    "Total times we took shortcut for sack processing");
1806 	rack_enter_tlp_calc = counter_u64_alloc(M_WAITOK);
1807 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1808 	    SYSCTL_CHILDREN(rack_counters),
1809 	    OID_AUTO, "tlp_calc_entered", CTLFLAG_RD,
1810 	    &rack_enter_tlp_calc,
1811 	    "Total times we called calc-tlp");
1812 	rack_used_tlpmethod = counter_u64_alloc(M_WAITOK);
1813 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1814 	    SYSCTL_CHILDREN(rack_counters),
1815 	    OID_AUTO, "hit_tlp_method", CTLFLAG_RD,
1816 	    &rack_used_tlpmethod,
1817 	    "Total number of runt sacks");
1818 	rack_used_tlpmethod2 = counter_u64_alloc(M_WAITOK);
1819 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1820 	    SYSCTL_CHILDREN(rack_counters),
1821 	    OID_AUTO, "hit_tlp_method2", CTLFLAG_RD,
1822 	    &rack_used_tlpmethod2,
1823 	    "Total number of times we hit TLP method 2");
1824 	rack_sack_skipped_acked = counter_u64_alloc(M_WAITOK);
1825 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1826 	    SYSCTL_CHILDREN(rack_attack),
1827 	    OID_AUTO, "skipacked", CTLFLAG_RD,
1828 	    &rack_sack_skipped_acked,
1829 	    "Total number of times we skipped previously sacked");
1830 	rack_sack_splits = counter_u64_alloc(M_WAITOK);
1831 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1832 	    SYSCTL_CHILDREN(rack_attack),
1833 	    OID_AUTO, "ofsplit", CTLFLAG_RD,
1834 	    &rack_sack_splits,
1835 	    "Total number of times we did the old fashion tree split");
1836 	rack_progress_drops = counter_u64_alloc(M_WAITOK);
1837 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1838 	    SYSCTL_CHILDREN(rack_counters),
1839 	    OID_AUTO, "prog_drops", CTLFLAG_RD,
1840 	    &rack_progress_drops,
1841 	    "Total number of progress drops");
1842 	rack_input_idle_reduces = counter_u64_alloc(M_WAITOK);
1843 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1844 	    SYSCTL_CHILDREN(rack_counters),
1845 	    OID_AUTO, "idle_reduce_oninput", CTLFLAG_RD,
1846 	    &rack_input_idle_reduces,
1847 	    "Total number of idle reductions on input");
1848 	rack_collapsed_win = counter_u64_alloc(M_WAITOK);
1849 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1850 	    SYSCTL_CHILDREN(rack_counters),
1851 	    OID_AUTO, "collapsed_win", CTLFLAG_RD,
1852 	    &rack_collapsed_win,
1853 	    "Total number of collapsed windows");
1854 	rack_tlp_does_nada = counter_u64_alloc(M_WAITOK);
1855 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1856 	    SYSCTL_CHILDREN(rack_counters),
1857 	    OID_AUTO, "tlp_nada", CTLFLAG_RD,
1858 	    &rack_tlp_does_nada,
1859 	    "Total number of nada tlp calls");
1860 	rack_try_scwnd = counter_u64_alloc(M_WAITOK);
1861 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1862 	    SYSCTL_CHILDREN(rack_counters),
1863 	    OID_AUTO, "tried_scwnd", CTLFLAG_RD,
1864 	    &rack_try_scwnd,
1865 	    "Total number of scwnd attempts");
1866 
1867 	rack_per_timer_hole = counter_u64_alloc(M_WAITOK);
1868 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1869 	    SYSCTL_CHILDREN(rack_counters),
1870 	    OID_AUTO, "timer_hole", CTLFLAG_RD,
1871 	    &rack_per_timer_hole,
1872 	    "Total persists start in timer hole");
1873 
1874 	rack_sbsndptr_wrong = counter_u64_alloc(M_WAITOK);
1875 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1876 	    SYSCTL_CHILDREN(rack_counters),
1877 	    OID_AUTO, "sndptr_wrong", CTLFLAG_RD,
1878 	    &rack_sbsndptr_wrong, "Total number of times the saved sbsndptr was incorret");
1879 	rack_sbsndptr_right = counter_u64_alloc(M_WAITOK);
1880 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1881 	    SYSCTL_CHILDREN(rack_counters),
1882 	    OID_AUTO, "sndptr_right", CTLFLAG_RD,
1883 	    &rack_sbsndptr_right, "Total number of times the saved sbsndptr was corret");
1884 
1885 	COUNTER_ARRAY_ALLOC(rack_out_size, TCP_MSS_ACCT_SIZE, M_WAITOK);
1886 	SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
1887 	    OID_AUTO, "outsize", CTLFLAG_RD,
1888 	    rack_out_size, TCP_MSS_ACCT_SIZE, "MSS send sizes");
1889 	COUNTER_ARRAY_ALLOC(rack_opts_arry, RACK_OPTS_SIZE, M_WAITOK);
1890 	SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
1891 	    OID_AUTO, "opts", CTLFLAG_RD,
1892 	    rack_opts_arry, RACK_OPTS_SIZE, "RACK Option Stats");
1893 	SYSCTL_ADD_PROC(&rack_sysctl_ctx,
1894 	    SYSCTL_CHILDREN(rack_sysctl_root),
1895 	    OID_AUTO, "clear", CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE,
1896 	    &rack_clear_counter, 0, sysctl_rack_clear, "IU", "Clear counters");
1897 }
1898 
1899 static __inline int
1900 rb_map_cmp(struct rack_sendmap *b, struct rack_sendmap *a)
1901 {
1902 	if (SEQ_GEQ(b->r_start, a->r_start) &&
1903 	    SEQ_LT(b->r_start, a->r_end)) {
1904 		/*
1905 		 * The entry b is within the
1906 		 * block a. i.e.:
1907 		 * a --   |-------------|
1908 		 * b --   |----|
1909 		 * <or>
1910 		 * b --       |------|
1911 		 * <or>
1912 		 * b --       |-----------|
1913 		 */
1914 		return (0);
1915 	} else if (SEQ_GEQ(b->r_start, a->r_end)) {
1916 		/*
1917 		 * b falls as either the next
1918 		 * sequence block after a so a
1919 		 * is said to be smaller than b.
1920 		 * i.e:
1921 		 * a --   |------|
1922 		 * b --          |--------|
1923 		 * or
1924 		 * b --              |-----|
1925 		 */
1926 		return (1);
1927 	}
1928 	/*
1929 	 * Whats left is where a is
1930 	 * larger than b. i.e:
1931 	 * a --         |-------|
1932 	 * b --  |---|
1933 	 * or even possibly
1934 	 * b --   |--------------|
1935 	 */
1936 	return (-1);
1937 }
1938 
1939 RB_PROTOTYPE(rack_rb_tree_head, rack_sendmap, r_next, rb_map_cmp);
1940 RB_GENERATE(rack_rb_tree_head, rack_sendmap, r_next, rb_map_cmp);
1941 
1942 static uint32_t
1943 rc_init_window(struct tcp_rack *rack)
1944 {
1945 	uint32_t win;
1946 
1947 	if (rack->rc_init_win == 0) {
1948 		/*
1949 		 * Nothing set by the user, use the system stack
1950 		 * default.
1951 		 */
1952 		return (tcp_compute_initwnd(tcp_maxseg(rack->rc_tp)));
1953 	}
1954 	win = ctf_fixed_maxseg(rack->rc_tp) * rack->rc_init_win;
1955 	return (win);
1956 }
1957 
1958 static uint64_t
1959 rack_get_fixed_pacing_bw(struct tcp_rack *rack)
1960 {
1961 	if (IN_FASTRECOVERY(rack->rc_tp->t_flags))
1962 		return (rack->r_ctl.rc_fixed_pacing_rate_rec);
1963 	else if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
1964 		return (rack->r_ctl.rc_fixed_pacing_rate_ss);
1965 	else
1966 		return (rack->r_ctl.rc_fixed_pacing_rate_ca);
1967 }
1968 
1969 static uint64_t
1970 rack_get_bw(struct tcp_rack *rack)
1971 {
1972 	if (rack->use_fixed_rate) {
1973 		/* Return the fixed pacing rate */
1974 		return (rack_get_fixed_pacing_bw(rack));
1975 	}
1976 	if (rack->r_ctl.gp_bw == 0) {
1977 		/*
1978 		 * We have yet no b/w measurement,
1979 		 * if we have a user set initial bw
1980 		 * return it. If we don't have that and
1981 		 * we have an srtt, use the tcp IW (10) to
1982 		 * calculate a fictional b/w over the SRTT
1983 		 * which is more or less a guess. Note
1984 		 * we don't use our IW from rack on purpose
1985 		 * so if we have like IW=30, we are not
1986 		 * calculating a "huge" b/w.
1987 		 */
1988 		uint64_t bw, srtt;
1989 		if (rack->r_ctl.init_rate)
1990 			return (rack->r_ctl.init_rate);
1991 
1992 		/* Has the user set a max peak rate? */
1993 #ifdef NETFLIX_PEAKRATE
1994 		if (rack->rc_tp->t_maxpeakrate)
1995 			return (rack->rc_tp->t_maxpeakrate);
1996 #endif
1997 		/* Ok lets come up with the IW guess, if we have a srtt */
1998 		if (rack->rc_tp->t_srtt == 0) {
1999 			/*
2000 			 * Go with old pacing method
2001 			 * i.e. burst mitigation only.
2002 			 */
2003 			return (0);
2004 		}
2005 		/* Ok lets get the initial TCP win (not racks) */
2006 		bw = tcp_compute_initwnd(tcp_maxseg(rack->rc_tp));
2007 		srtt = (uint64_t)rack->rc_tp->t_srtt;
2008 		bw *= (uint64_t)USECS_IN_SECOND;
2009 		bw /= srtt;
2010 		if (rack->r_ctl.bw_rate_cap && (bw > rack->r_ctl.bw_rate_cap))
2011 			bw = rack->r_ctl.bw_rate_cap;
2012 		return (bw);
2013 	} else {
2014 		uint64_t bw;
2015 
2016 		if (rack->r_ctl.num_measurements >= RACK_REQ_AVG) {
2017 			/* Averaging is done, we can return the value */
2018 			bw = rack->r_ctl.gp_bw;
2019 		} else {
2020 			/* Still doing initial average must calculate */
2021 			bw = rack->r_ctl.gp_bw / rack->r_ctl.num_measurements;
2022 		}
2023 #ifdef NETFLIX_PEAKRATE
2024 		if ((rack->rc_tp->t_maxpeakrate) &&
2025 		    (bw > rack->rc_tp->t_maxpeakrate)) {
2026 			/* The user has set a peak rate to pace at
2027 			 * don't allow us to pace faster than that.
2028 			 */
2029 			return (rack->rc_tp->t_maxpeakrate);
2030 		}
2031 #endif
2032 		if (rack->r_ctl.bw_rate_cap && (bw > rack->r_ctl.bw_rate_cap))
2033 			bw = rack->r_ctl.bw_rate_cap;
2034 		return (bw);
2035 	}
2036 }
2037 
2038 static uint16_t
2039 rack_get_output_gain(struct tcp_rack *rack, struct rack_sendmap *rsm)
2040 {
2041 	if (rack->use_fixed_rate) {
2042 		return (100);
2043 	} else if (rack->in_probe_rtt && (rsm == NULL))
2044 		return (rack->r_ctl.rack_per_of_gp_probertt);
2045 	else if ((IN_FASTRECOVERY(rack->rc_tp->t_flags) &&
2046 		  rack->r_ctl.rack_per_of_gp_rec)) {
2047 		if (rsm) {
2048 			/* a retransmission always use the recovery rate */
2049 			return (rack->r_ctl.rack_per_of_gp_rec);
2050 		} else if (rack->rack_rec_nonrxt_use_cr) {
2051 			/* Directed to use the configured rate */
2052 			goto configured_rate;
2053 		} else if (rack->rack_no_prr &&
2054 			   (rack->r_ctl.rack_per_of_gp_rec > 100)) {
2055 			/* No PRR, lets just use the b/w estimate only */
2056 			return (100);
2057 		} else {
2058 			/*
2059 			 * Here we may have a non-retransmit but we
2060 			 * have no overrides, so just use the recovery
2061 			 * rate (prr is in effect).
2062 			 */
2063 			return (rack->r_ctl.rack_per_of_gp_rec);
2064 		}
2065 	}
2066 configured_rate:
2067 	/* For the configured rate we look at our cwnd vs the ssthresh */
2068 	if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
2069 		return (rack->r_ctl.rack_per_of_gp_ss);
2070 	else
2071 		return (rack->r_ctl.rack_per_of_gp_ca);
2072 }
2073 
2074 static void
2075 rack_log_hdwr_pacing(struct tcp_rack *rack,
2076 		     uint64_t rate, uint64_t hw_rate, int line,
2077 		     int error, uint16_t mod)
2078 {
2079 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2080 		union tcp_log_stackspecific log;
2081 		struct timeval tv;
2082 		const struct ifnet *ifp;
2083 
2084 		memset(&log, 0, sizeof(log));
2085 		log.u_bbr.flex1 = ((hw_rate >> 32) & 0x00000000ffffffff);
2086 		log.u_bbr.flex2 = (hw_rate & 0x00000000ffffffff);
2087 		if (rack->r_ctl.crte) {
2088 			ifp = rack->r_ctl.crte->ptbl->rs_ifp;
2089 		} else if (rack->rc_inp->inp_route.ro_nh &&
2090 			   rack->rc_inp->inp_route.ro_nh->nh_ifp) {
2091 			ifp = rack->rc_inp->inp_route.ro_nh->nh_ifp;
2092 		} else
2093 			ifp = NULL;
2094 		if (ifp) {
2095 			log.u_bbr.flex3 = (((uint64_t)ifp  >> 32) & 0x00000000ffffffff);
2096 			log.u_bbr.flex4 = ((uint64_t)ifp & 0x00000000ffffffff);
2097 		}
2098 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2099 		log.u_bbr.bw_inuse = rate;
2100 		log.u_bbr.flex5 = line;
2101 		log.u_bbr.flex6 = error;
2102 		log.u_bbr.flex7 = mod;
2103 		log.u_bbr.applimited = rack->r_ctl.rc_pace_max_segs;
2104 		log.u_bbr.flex8 = rack->use_fixed_rate;
2105 		log.u_bbr.flex8 <<= 1;
2106 		log.u_bbr.flex8 |= rack->rack_hdrw_pacing;
2107 		log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
2108 		log.u_bbr.delRate = rack->r_ctl.crte_prev_rate;
2109 		if (rack->r_ctl.crte)
2110 			log.u_bbr.cur_del_rate = rack->r_ctl.crte->rate;
2111 		else
2112 			log.u_bbr.cur_del_rate = 0;
2113 		log.u_bbr.rttProp = rack->r_ctl.last_hw_bw_req;
2114 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2115 		    &rack->rc_inp->inp_socket->so_rcv,
2116 		    &rack->rc_inp->inp_socket->so_snd,
2117 		    BBR_LOG_HDWR_PACE, 0,
2118 		    0, &log, false, &tv);
2119 	}
2120 }
2121 
2122 static uint64_t
2123 rack_get_output_bw(struct tcp_rack *rack, uint64_t bw, struct rack_sendmap *rsm, int *capped)
2124 {
2125 	/*
2126 	 * We allow rack_per_of_gp_xx to dictate our bw rate we want.
2127 	 */
2128 	uint64_t bw_est, high_rate;
2129 	uint64_t gain;
2130 
2131 	gain = (uint64_t)rack_get_output_gain(rack, rsm);
2132 	bw_est = bw * gain;
2133 	bw_est /= (uint64_t)100;
2134 	/* Never fall below the minimum (def 64kbps) */
2135 	if (bw_est < RACK_MIN_BW)
2136 		bw_est = RACK_MIN_BW;
2137 	if (rack->r_rack_hw_rate_caps) {
2138 		/* Rate caps are in place */
2139 		if (rack->r_ctl.crte != NULL) {
2140 			/* We have a hdwr rate already */
2141 			high_rate = tcp_hw_highest_rate(rack->r_ctl.crte);
2142 			if (bw_est >= high_rate) {
2143 				/* We are capping bw at the highest rate table entry */
2144 				rack_log_hdwr_pacing(rack,
2145 						     bw_est, high_rate, __LINE__,
2146 						     0, 3);
2147 				bw_est = high_rate;
2148 				if (capped)
2149 					*capped = 1;
2150 			}
2151 		} else if ((rack->rack_hdrw_pacing == 0) &&
2152 			   (rack->rack_hdw_pace_ena) &&
2153 			   (rack->rack_attempt_hdwr_pace == 0) &&
2154 			   (rack->rc_inp->inp_route.ro_nh != NULL) &&
2155 			   (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
2156 			/*
2157 			 * Special case, we have not yet attempted hardware
2158 			 * pacing, and yet we may, when we do, find out if we are
2159 			 * above the highest rate. We need to know the maxbw for the interface
2160 			 * in question (if it supports ratelimiting). We get back
2161 			 * a 0, if the interface is not found in the RL lists.
2162 			 */
2163 			high_rate = tcp_hw_highest_rate_ifp(rack->rc_inp->inp_route.ro_nh->nh_ifp, rack->rc_inp);
2164 			if (high_rate) {
2165 				/* Yep, we have a rate is it above this rate? */
2166 				if (bw_est > high_rate) {
2167 					bw_est = high_rate;
2168 					if (capped)
2169 						*capped = 1;
2170 				}
2171 			}
2172 		}
2173 	}
2174 	return (bw_est);
2175 }
2176 
2177 static void
2178 rack_log_retran_reason(struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t tsused, uint32_t thresh, int mod)
2179 {
2180 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2181 		union tcp_log_stackspecific log;
2182 		struct timeval tv;
2183 
2184 		if ((mod != 1) && (rack_verbose_logging == 0)) {
2185 			/*
2186 			 * We get 3 values currently for mod
2187 			 * 1 - We are retransmitting and this tells the reason.
2188 			 * 2 - We are clearing a dup-ack count.
2189 			 * 3 - We are incrementing a dup-ack count.
2190 			 *
2191 			 * The clear/increment are only logged
2192 			 * if you have BBverbose on.
2193 			 */
2194 			return;
2195 		}
2196 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2197 		log.u_bbr.flex1 = tsused;
2198 		log.u_bbr.flex2 = thresh;
2199 		log.u_bbr.flex3 = rsm->r_flags;
2200 		log.u_bbr.flex4 = rsm->r_dupack;
2201 		log.u_bbr.flex5 = rsm->r_start;
2202 		log.u_bbr.flex6 = rsm->r_end;
2203 		log.u_bbr.flex8 = mod;
2204 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2205 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2206 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2207 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2208 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2209 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2210 		log.u_bbr.pacing_gain = rack->r_must_retran;
2211 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2212 		    &rack->rc_inp->inp_socket->so_rcv,
2213 		    &rack->rc_inp->inp_socket->so_snd,
2214 		    BBR_LOG_SETTINGS_CHG, 0,
2215 		    0, &log, false, &tv);
2216 	}
2217 }
2218 
2219 static void
2220 rack_log_to_start(struct tcp_rack *rack, uint32_t cts, uint32_t to, int32_t slot, uint8_t which)
2221 {
2222 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2223 		union tcp_log_stackspecific log;
2224 		struct timeval tv;
2225 
2226 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2227 		log.u_bbr.flex1 = rack->rc_tp->t_srtt;
2228 		log.u_bbr.flex2 = to;
2229 		log.u_bbr.flex3 = rack->r_ctl.rc_hpts_flags;
2230 		log.u_bbr.flex4 = slot;
2231 		log.u_bbr.flex5 = rack->rc_inp->inp_hptsslot;
2232 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2233 		log.u_bbr.flex7 = rack->rc_in_persist;
2234 		log.u_bbr.flex8 = which;
2235 		if (rack->rack_no_prr)
2236 			log.u_bbr.pkts_out = 0;
2237 		else
2238 			log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
2239 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2240 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2241 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2242 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2243 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2244 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2245 		log.u_bbr.pacing_gain = rack->r_must_retran;
2246 		log.u_bbr.lt_epoch = rack->rc_tp->t_rxtshift;
2247 		log.u_bbr.lost = rack_rto_min;
2248 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2249 		    &rack->rc_inp->inp_socket->so_rcv,
2250 		    &rack->rc_inp->inp_socket->so_snd,
2251 		    BBR_LOG_TIMERSTAR, 0,
2252 		    0, &log, false, &tv);
2253 	}
2254 }
2255 
2256 static void
2257 rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm)
2258 {
2259 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2260 		union tcp_log_stackspecific log;
2261 		struct timeval tv;
2262 
2263 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2264 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2265 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2266 		log.u_bbr.flex8 = to_num;
2267 		log.u_bbr.flex1 = rack->r_ctl.rc_rack_min_rtt;
2268 		log.u_bbr.flex2 = rack->rc_rack_rtt;
2269 		if (rsm == NULL)
2270 			log.u_bbr.flex3 = 0;
2271 		else
2272 			log.u_bbr.flex3 = rsm->r_end - rsm->r_start;
2273 		if (rack->rack_no_prr)
2274 			log.u_bbr.flex5 = 0;
2275 		else
2276 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2277 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2278 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2279 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2280 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2281 		log.u_bbr.pacing_gain = rack->r_must_retran;
2282 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2283 		    &rack->rc_inp->inp_socket->so_rcv,
2284 		    &rack->rc_inp->inp_socket->so_snd,
2285 		    BBR_LOG_RTO, 0,
2286 		    0, &log, false, &tv);
2287 	}
2288 }
2289 
2290 static void
2291 rack_log_map_chg(struct tcpcb *tp, struct tcp_rack *rack,
2292 		 struct rack_sendmap *prev,
2293 		 struct rack_sendmap *rsm,
2294 		 struct rack_sendmap *next,
2295 		 int flag, uint32_t th_ack, int line)
2296 {
2297 	if (rack_verbose_logging && (tp->t_logstate != TCP_LOG_STATE_OFF)) {
2298 		union tcp_log_stackspecific log;
2299 		struct timeval tv;
2300 
2301 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2302 		log.u_bbr.flex8 = flag;
2303 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2304 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2305 		log.u_bbr.cur_del_rate = (uint64_t)prev;
2306 		log.u_bbr.delRate = (uint64_t)rsm;
2307 		log.u_bbr.rttProp = (uint64_t)next;
2308 		log.u_bbr.flex7 = 0;
2309 		if (prev) {
2310 			log.u_bbr.flex1 = prev->r_start;
2311 			log.u_bbr.flex2 = prev->r_end;
2312 			log.u_bbr.flex7 |= 0x4;
2313 		}
2314 		if (rsm) {
2315 			log.u_bbr.flex3 = rsm->r_start;
2316 			log.u_bbr.flex4 = rsm->r_end;
2317 			log.u_bbr.flex7 |= 0x2;
2318 		}
2319 		if (next) {
2320 			log.u_bbr.flex5 = next->r_start;
2321 			log.u_bbr.flex6 = next->r_end;
2322 			log.u_bbr.flex7 |= 0x1;
2323 		}
2324 		log.u_bbr.applimited = line;
2325 		log.u_bbr.pkts_out = th_ack;
2326 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2327 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2328 		if (rack->rack_no_prr)
2329 			log.u_bbr.lost = 0;
2330 		else
2331 			log.u_bbr.lost = rack->r_ctl.rc_prr_sndcnt;
2332 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2333 		    &rack->rc_inp->inp_socket->so_rcv,
2334 		    &rack->rc_inp->inp_socket->so_snd,
2335 		    TCP_LOG_MAPCHG, 0,
2336 		    0, &log, false, &tv);
2337 	}
2338 }
2339 
2340 static void
2341 rack_log_rtt_upd(struct tcpcb *tp, struct tcp_rack *rack, uint32_t t, uint32_t len,
2342 		 struct rack_sendmap *rsm, int conf)
2343 {
2344 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
2345 		union tcp_log_stackspecific log;
2346 		struct timeval tv;
2347 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2348 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2349 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2350 		log.u_bbr.flex1 = t;
2351 		log.u_bbr.flex2 = len;
2352 		log.u_bbr.flex3 = rack->r_ctl.rc_rack_min_rtt;
2353 		log.u_bbr.flex4 = rack->r_ctl.rack_rs.rs_rtt_lowest;
2354 		log.u_bbr.flex5 = rack->r_ctl.rack_rs.rs_rtt_highest;
2355 		log.u_bbr.flex6 = rack->r_ctl.rack_rs.rs_us_rtrcnt;
2356 		log.u_bbr.flex7 = conf;
2357 		log.u_bbr.rttProp = (uint64_t)rack->r_ctl.rack_rs.rs_rtt_tot;
2358 		log.u_bbr.flex8 = rack->r_ctl.rc_rate_sample_method;
2359 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2360 		log.u_bbr.delivered = rack->r_ctl.rack_rs.rs_us_rtrcnt;
2361 		log.u_bbr.pkts_out = rack->r_ctl.rack_rs.rs_flags;
2362 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2363 		if (rsm) {
2364 			log.u_bbr.pkt_epoch = rsm->r_start;
2365 			log.u_bbr.lost = rsm->r_end;
2366 			log.u_bbr.cwnd_gain = rsm->r_rtr_cnt;
2367 			log.u_bbr.pacing_gain = rsm->r_flags;
2368 		} else {
2369 			/* Its a SYN */
2370 			log.u_bbr.pkt_epoch = rack->rc_tp->iss;
2371 			log.u_bbr.lost = 0;
2372 			log.u_bbr.cwnd_gain = 0;
2373 			log.u_bbr.pacing_gain = 0;
2374 		}
2375 		/* Write out general bits of interest rrs here */
2376 		log.u_bbr.use_lt_bw = rack->rc_highly_buffered;
2377 		log.u_bbr.use_lt_bw <<= 1;
2378 		log.u_bbr.use_lt_bw |= rack->forced_ack;
2379 		log.u_bbr.use_lt_bw <<= 1;
2380 		log.u_bbr.use_lt_bw |= rack->rc_gp_dyn_mul;
2381 		log.u_bbr.use_lt_bw <<= 1;
2382 		log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
2383 		log.u_bbr.use_lt_bw <<= 1;
2384 		log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
2385 		log.u_bbr.use_lt_bw <<= 1;
2386 		log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
2387 		log.u_bbr.use_lt_bw <<= 1;
2388 		log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
2389 		log.u_bbr.use_lt_bw <<= 1;
2390 		log.u_bbr.use_lt_bw |= rack->rc_dragged_bottom;
2391 		log.u_bbr.applimited = rack->r_ctl.rc_target_probertt_flight;
2392 		log.u_bbr.epoch = rack->r_ctl.rc_time_probertt_starts;
2393 		log.u_bbr.lt_epoch = rack->r_ctl.rc_time_probertt_entered;
2394 		log.u_bbr.cur_del_rate = rack->r_ctl.rc_lower_rtt_us_cts;
2395 		log.u_bbr.delRate = rack->r_ctl.rc_gp_srtt;
2396 		log.u_bbr.bw_inuse = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
2397 		log.u_bbr.bw_inuse <<= 32;
2398 		if (rsm)
2399 			log.u_bbr.bw_inuse |= ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]);
2400 		TCP_LOG_EVENTP(tp, NULL,
2401 		    &rack->rc_inp->inp_socket->so_rcv,
2402 		    &rack->rc_inp->inp_socket->so_snd,
2403 		    BBR_LOG_BBRRTT, 0,
2404 		    0, &log, false, &tv);
2405 
2406 
2407 	}
2408 }
2409 
2410 static void
2411 rack_log_rtt_sample(struct tcp_rack *rack, uint32_t rtt)
2412 {
2413 	/*
2414 	 * Log the rtt sample we are
2415 	 * applying to the srtt algorithm in
2416 	 * useconds.
2417 	 */
2418 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2419 		union tcp_log_stackspecific log;
2420 		struct timeval tv;
2421 
2422 		/* Convert our ms to a microsecond */
2423 		memset(&log, 0, sizeof(log));
2424 		log.u_bbr.flex1 = rtt;
2425 		log.u_bbr.flex2 = rack->r_ctl.ack_count;
2426 		log.u_bbr.flex3 = rack->r_ctl.sack_count;
2427 		log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move;
2428 		log.u_bbr.flex5 = rack->r_ctl.sack_moved_extra;
2429 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2430 		log.u_bbr.flex7 = 1;
2431 		log.u_bbr.flex8 = rack->sack_attack_disable;
2432 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2433 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2434 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2435 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2436 		log.u_bbr.pacing_gain = rack->r_must_retran;
2437 		/*
2438 		 * We capture in delRate the upper 32 bits as
2439 		 * the confidence level we had declared, and the
2440 		 * lower 32 bits as the actual RTT using the arrival
2441 		 * timestamp.
2442 		 */
2443 		log.u_bbr.delRate = rack->r_ctl.rack_rs.confidence;
2444 		log.u_bbr.delRate <<= 32;
2445 		log.u_bbr.delRate |= rack->r_ctl.rack_rs.rs_us_rtt;
2446 		/* Lets capture all the things that make up t_rtxcur */
2447 		log.u_bbr.applimited = rack_rto_min;
2448 		log.u_bbr.epoch = rack_rto_max;
2449 		log.u_bbr.lt_epoch = rack->r_ctl.timer_slop;
2450 		log.u_bbr.lost = rack_rto_min;
2451 		log.u_bbr.pkt_epoch = TICKS_2_USEC(tcp_rexmit_slop);
2452 		log.u_bbr.rttProp = RACK_REXMTVAL(rack->rc_tp);
2453 		log.u_bbr.bw_inuse = rack->r_ctl.act_rcv_time.tv_sec;
2454 		log.u_bbr.bw_inuse *= HPTS_USEC_IN_SEC;
2455 		log.u_bbr.bw_inuse += rack->r_ctl.act_rcv_time.tv_usec;
2456 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2457 		    &rack->rc_inp->inp_socket->so_rcv,
2458 		    &rack->rc_inp->inp_socket->so_snd,
2459 		    TCP_LOG_RTT, 0,
2460 		    0, &log, false, &tv);
2461 	}
2462 }
2463 
2464 static void
2465 rack_log_rtt_sample_calc(struct tcp_rack *rack, uint32_t rtt, uint32_t send_time, uint32_t ack_time, int where)
2466 {
2467 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
2468 		union tcp_log_stackspecific log;
2469 		struct timeval tv;
2470 
2471 		/* Convert our ms to a microsecond */
2472 		memset(&log, 0, sizeof(log));
2473 		log.u_bbr.flex1 = rtt;
2474 		log.u_bbr.flex2 = send_time;
2475 		log.u_bbr.flex3 = ack_time;
2476 		log.u_bbr.flex4 = where;
2477 		log.u_bbr.flex7 = 2;
2478 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
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 		    TCP_LOG_RTT, 0,
2483 		    0, &log, false, &tv);
2484 	}
2485 }
2486 
2487 
2488 
2489 static inline void
2490 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick,  int event, int line)
2491 {
2492 	if (rack_verbose_logging && (tp->t_logstate != TCP_LOG_STATE_OFF)) {
2493 		union tcp_log_stackspecific log;
2494 		struct timeval tv;
2495 
2496 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2497 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2498 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2499 		log.u_bbr.flex1 = line;
2500 		log.u_bbr.flex2 = tick;
2501 		log.u_bbr.flex3 = tp->t_maxunacktime;
2502 		log.u_bbr.flex4 = tp->t_acktime;
2503 		log.u_bbr.flex8 = event;
2504 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2505 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2506 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2507 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2508 		log.u_bbr.pacing_gain = rack->r_must_retran;
2509 		TCP_LOG_EVENTP(tp, NULL,
2510 		    &rack->rc_inp->inp_socket->so_rcv,
2511 		    &rack->rc_inp->inp_socket->so_snd,
2512 		    BBR_LOG_PROGRESS, 0,
2513 		    0, &log, false, &tv);
2514 	}
2515 }
2516 
2517 static void
2518 rack_log_type_bbrsnd(struct tcp_rack *rack, uint32_t len, uint32_t slot, uint32_t cts, struct timeval *tv)
2519 {
2520 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2521 		union tcp_log_stackspecific log;
2522 
2523 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2524 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2525 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2526 		log.u_bbr.flex1 = slot;
2527 		if (rack->rack_no_prr)
2528 			log.u_bbr.flex2 = 0;
2529 		else
2530 			log.u_bbr.flex2 = rack->r_ctl.rc_prr_sndcnt;
2531 		log.u_bbr.flex7 = (0x0000ffff & rack->r_ctl.rc_hpts_flags);
2532 		log.u_bbr.flex8 = rack->rc_in_persist;
2533 		log.u_bbr.timeStamp = cts;
2534 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2535 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2536 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2537 		log.u_bbr.pacing_gain = rack->r_must_retran;
2538 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2539 		    &rack->rc_inp->inp_socket->so_rcv,
2540 		    &rack->rc_inp->inp_socket->so_snd,
2541 		    BBR_LOG_BBRSND, 0,
2542 		    0, &log, false, tv);
2543 	}
2544 }
2545 
2546 static void
2547 rack_log_doseg_done(struct tcp_rack *rack, uint32_t cts, int32_t nxt_pkt, int32_t did_out, int way_out, int nsegs)
2548 {
2549 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2550 		union tcp_log_stackspecific log;
2551 		struct timeval tv;
2552 
2553 		memset(&log, 0, sizeof(log));
2554 		log.u_bbr.flex1 = did_out;
2555 		log.u_bbr.flex2 = nxt_pkt;
2556 		log.u_bbr.flex3 = way_out;
2557 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
2558 		if (rack->rack_no_prr)
2559 			log.u_bbr.flex5 = 0;
2560 		else
2561 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2562 		log.u_bbr.flex6 = nsegs;
2563 		log.u_bbr.applimited = rack->r_ctl.rc_pace_min_segs;
2564 		log.u_bbr.flex7 = rack->rc_ack_can_sendout_data;	/* Do we have ack-can-send set */
2565 		log.u_bbr.flex7 <<= 1;
2566 		log.u_bbr.flex7 |= rack->r_fast_output;	/* is fast output primed */
2567 		log.u_bbr.flex7 <<= 1;
2568 		log.u_bbr.flex7 |= rack->r_wanted_output;	/* Do we want output */
2569 		log.u_bbr.flex8 = rack->rc_in_persist;
2570 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2571 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2572 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2573 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
2574 		log.u_bbr.use_lt_bw <<= 1;
2575 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
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 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2580 		    &rack->rc_inp->inp_socket->so_rcv,
2581 		    &rack->rc_inp->inp_socket->so_snd,
2582 		    BBR_LOG_DOSEG_DONE, 0,
2583 		    0, &log, false, &tv);
2584 	}
2585 }
2586 
2587 static void
2588 rack_log_type_pacing_sizes(struct tcpcb *tp, struct tcp_rack *rack, uint32_t arg1, uint32_t arg2, uint32_t arg3, uint8_t frm)
2589 {
2590 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
2591 		union tcp_log_stackspecific log;
2592 		struct timeval tv;
2593 		uint32_t cts;
2594 
2595 		memset(&log, 0, sizeof(log));
2596 		cts = tcp_get_usecs(&tv);
2597 		log.u_bbr.flex1 = rack->r_ctl.rc_pace_min_segs;
2598 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
2599 		log.u_bbr.flex4 = arg1;
2600 		log.u_bbr.flex5 = arg2;
2601 		log.u_bbr.flex6 = arg3;
2602 		log.u_bbr.flex8 = frm;
2603 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2604 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2605 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2606 		log.u_bbr.applimited = rack->r_ctl.rc_sacked;
2607 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2608 		log.u_bbr.pacing_gain = rack->r_must_retran;
2609 		TCP_LOG_EVENTP(tp, NULL,
2610 		    &tp->t_inpcb->inp_socket->so_rcv,
2611 		    &tp->t_inpcb->inp_socket->so_snd,
2612 		    TCP_HDWR_PACE_SIZE, 0,
2613 		    0, &log, false, &tv);
2614 	}
2615 }
2616 
2617 static void
2618 rack_log_type_just_return(struct tcp_rack *rack, uint32_t cts, uint32_t tlen, uint32_t slot,
2619 			  uint8_t hpts_calling, int reason, uint32_t cwnd_to_use)
2620 {
2621 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2622 		union tcp_log_stackspecific log;
2623 		struct timeval tv;
2624 
2625 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2626 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2627 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2628 		log.u_bbr.flex1 = slot;
2629 		log.u_bbr.flex2 = rack->r_ctl.rc_hpts_flags;
2630 		log.u_bbr.flex4 = reason;
2631 		if (rack->rack_no_prr)
2632 			log.u_bbr.flex5 = 0;
2633 		else
2634 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2635 		log.u_bbr.flex7 = hpts_calling;
2636 		log.u_bbr.flex8 = rack->rc_in_persist;
2637 		log.u_bbr.lt_epoch = cwnd_to_use;
2638 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2639 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2640 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2641 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2642 		log.u_bbr.pacing_gain = rack->r_must_retran;
2643 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2644 		    &rack->rc_inp->inp_socket->so_rcv,
2645 		    &rack->rc_inp->inp_socket->so_snd,
2646 		    BBR_LOG_JUSTRET, 0,
2647 		    tlen, &log, false, &tv);
2648 	}
2649 }
2650 
2651 static void
2652 rack_log_to_cancel(struct tcp_rack *rack, int32_t hpts_removed, int line, uint32_t us_cts,
2653 		   struct timeval *tv, uint32_t flags_on_entry)
2654 {
2655 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2656 		union tcp_log_stackspecific log;
2657 
2658 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2659 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
2660 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
2661 		log.u_bbr.flex1 = line;
2662 		log.u_bbr.flex2 = rack->r_ctl.rc_last_output_to;
2663 		log.u_bbr.flex3 = flags_on_entry;
2664 		log.u_bbr.flex4 = us_cts;
2665 		if (rack->rack_no_prr)
2666 			log.u_bbr.flex5 = 0;
2667 		else
2668 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2669 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2670 		log.u_bbr.flex7 = hpts_removed;
2671 		log.u_bbr.flex8 = 1;
2672 		log.u_bbr.applimited = rack->r_ctl.rc_hpts_flags;
2673 		log.u_bbr.timeStamp = us_cts;
2674 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2675 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2676 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2677 		log.u_bbr.pacing_gain = rack->r_must_retran;
2678 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2679 		    &rack->rc_inp->inp_socket->so_rcv,
2680 		    &rack->rc_inp->inp_socket->so_snd,
2681 		    BBR_LOG_TIMERCANC, 0,
2682 		    0, &log, false, tv);
2683 	}
2684 }
2685 
2686 static void
2687 rack_log_alt_to_to_cancel(struct tcp_rack *rack,
2688 			  uint32_t flex1, uint32_t flex2,
2689 			  uint32_t flex3, uint32_t flex4,
2690 			  uint32_t flex5, uint32_t flex6,
2691 			  uint16_t flex7, uint8_t mod)
2692 {
2693 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2694 		union tcp_log_stackspecific log;
2695 		struct timeval tv;
2696 
2697 		if (mod == 1) {
2698 			/* No you can't use 1, its for the real to cancel */
2699 			return;
2700 		}
2701 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2702 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2703 		log.u_bbr.flex1 = flex1;
2704 		log.u_bbr.flex2 = flex2;
2705 		log.u_bbr.flex3 = flex3;
2706 		log.u_bbr.flex4 = flex4;
2707 		log.u_bbr.flex5 = flex5;
2708 		log.u_bbr.flex6 = flex6;
2709 		log.u_bbr.flex7 = flex7;
2710 		log.u_bbr.flex8 = mod;
2711 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2712 		    &rack->rc_inp->inp_socket->so_rcv,
2713 		    &rack->rc_inp->inp_socket->so_snd,
2714 		    BBR_LOG_TIMERCANC, 0,
2715 		    0, &log, false, &tv);
2716 	}
2717 }
2718 
2719 static void
2720 rack_log_to_processing(struct tcp_rack *rack, uint32_t cts, int32_t ret, int32_t timers)
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 = timers;
2728 		log.u_bbr.flex2 = ret;
2729 		log.u_bbr.flex3 = rack->r_ctl.rc_timer_exp;
2730 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
2731 		log.u_bbr.flex5 = cts;
2732 		if (rack->rack_no_prr)
2733 			log.u_bbr.flex6 = 0;
2734 		else
2735 			log.u_bbr.flex6 = rack->r_ctl.rc_prr_sndcnt;
2736 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2737 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2738 		log.u_bbr.pacing_gain = rack->r_must_retran;
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 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2742 		    &rack->rc_inp->inp_socket->so_rcv,
2743 		    &rack->rc_inp->inp_socket->so_snd,
2744 		    BBR_LOG_TO_PROCESS, 0,
2745 		    0, &log, false, &tv);
2746 	}
2747 }
2748 
2749 static void
2750 rack_log_to_prr(struct tcp_rack *rack, int frm, int orig_cwnd)
2751 {
2752 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2753 		union tcp_log_stackspecific log;
2754 		struct timeval tv;
2755 
2756 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2757 		log.u_bbr.flex1 = rack->r_ctl.rc_prr_out;
2758 		log.u_bbr.flex2 = rack->r_ctl.rc_prr_recovery_fs;
2759 		if (rack->rack_no_prr)
2760 			log.u_bbr.flex3 = 0;
2761 		else
2762 			log.u_bbr.flex3 = rack->r_ctl.rc_prr_sndcnt;
2763 		log.u_bbr.flex4 = rack->r_ctl.rc_prr_delivered;
2764 		log.u_bbr.flex5 = rack->r_ctl.rc_sacked;
2765 		log.u_bbr.flex6 = rack->r_ctl.rc_holes_rxt;
2766 		log.u_bbr.flex8 = frm;
2767 		log.u_bbr.pkts_out = orig_cwnd;
2768 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2769 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2770 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
2771 		log.u_bbr.use_lt_bw <<= 1;
2772 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
2773 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2774 		    &rack->rc_inp->inp_socket->so_rcv,
2775 		    &rack->rc_inp->inp_socket->so_snd,
2776 		    BBR_LOG_BBRUPD, 0,
2777 		    0, &log, false, &tv);
2778 	}
2779 }
2780 
2781 #ifdef NETFLIX_EXP_DETECTION
2782 static void
2783 rack_log_sad(struct tcp_rack *rack, int event)
2784 {
2785 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2786 		union tcp_log_stackspecific log;
2787 		struct timeval tv;
2788 
2789 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2790 		log.u_bbr.flex1 = rack->r_ctl.sack_count;
2791 		log.u_bbr.flex2 = rack->r_ctl.ack_count;
2792 		log.u_bbr.flex3 = rack->r_ctl.sack_moved_extra;
2793 		log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move;
2794 		log.u_bbr.flex5 = rack->r_ctl.rc_num_maps_alloced;
2795 		log.u_bbr.flex6 = tcp_sack_to_ack_thresh;
2796 		log.u_bbr.pkts_out = tcp_sack_to_move_thresh;
2797 		log.u_bbr.lt_epoch = (tcp_force_detection << 8);
2798 		log.u_bbr.lt_epoch |= rack->do_detection;
2799 		log.u_bbr.applimited = tcp_map_minimum;
2800 		log.u_bbr.flex7 = rack->sack_attack_disable;
2801 		log.u_bbr.flex8 = event;
2802 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2803 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2804 		log.u_bbr.delivered = tcp_sad_decay_val;
2805 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2806 		    &rack->rc_inp->inp_socket->so_rcv,
2807 		    &rack->rc_inp->inp_socket->so_snd,
2808 		    TCP_SAD_DETECTION, 0,
2809 		    0, &log, false, &tv);
2810 	}
2811 }
2812 #endif
2813 
2814 static void
2815 rack_counter_destroy(void)
2816 {
2817 	int i;
2818 
2819 	counter_u64_free(rack_fto_send);
2820 	counter_u64_free(rack_fto_rsm_send);
2821 	counter_u64_free(rack_nfto_resend);
2822 	counter_u64_free(rack_hw_pace_init_fail);
2823 	counter_u64_free(rack_hw_pace_lost);
2824 	counter_u64_free(rack_non_fto_send);
2825 	counter_u64_free(rack_extended_rfo);
2826 	counter_u64_free(rack_ack_total);
2827 	counter_u64_free(rack_express_sack);
2828 	counter_u64_free(rack_sack_total);
2829 	counter_u64_free(rack_move_none);
2830 	counter_u64_free(rack_move_some);
2831 	counter_u64_free(rack_sack_attacks_detected);
2832 	counter_u64_free(rack_sack_attacks_reversed);
2833 	counter_u64_free(rack_sack_used_next_merge);
2834 	counter_u64_free(rack_sack_used_prev_merge);
2835 	counter_u64_free(rack_badfr);
2836 	counter_u64_free(rack_badfr_bytes);
2837 	counter_u64_free(rack_rtm_prr_retran);
2838 	counter_u64_free(rack_rtm_prr_newdata);
2839 	counter_u64_free(rack_timestamp_mismatch);
2840 	counter_u64_free(rack_find_high);
2841 	counter_u64_free(rack_reorder_seen);
2842 	counter_u64_free(rack_tlp_tot);
2843 	counter_u64_free(rack_tlp_newdata);
2844 	counter_u64_free(rack_tlp_retran);
2845 	counter_u64_free(rack_tlp_retran_bytes);
2846 	counter_u64_free(rack_tlp_retran_fail);
2847 	counter_u64_free(rack_to_tot);
2848 	counter_u64_free(rack_to_arm_rack);
2849 	counter_u64_free(rack_to_arm_tlp);
2850 	counter_u64_free(rack_calc_zero);
2851 	counter_u64_free(rack_calc_nonzero);
2852 	counter_u64_free(rack_paced_segments);
2853 	counter_u64_free(rack_unpaced_segments);
2854 	counter_u64_free(rack_saw_enobuf);
2855 	counter_u64_free(rack_saw_enobuf_hw);
2856 	counter_u64_free(rack_saw_enetunreach);
2857 	counter_u64_free(rack_hot_alloc);
2858 	counter_u64_free(rack_to_alloc);
2859 	counter_u64_free(rack_to_alloc_hard);
2860 	counter_u64_free(rack_to_alloc_emerg);
2861 	counter_u64_free(rack_to_alloc_limited);
2862 	counter_u64_free(rack_alloc_limited_conns);
2863 	counter_u64_free(rack_split_limited);
2864 	for (i = 0; i < MAX_NUM_OF_CNTS; i++) {
2865 		counter_u64_free(rack_proc_comp_ack[i]);
2866 	}
2867 	counter_u64_free(rack_multi_single_eq);
2868 	counter_u64_free(rack_proc_non_comp_ack);
2869 	counter_u64_free(rack_sack_proc_all);
2870 	counter_u64_free(rack_sack_proc_restart);
2871 	counter_u64_free(rack_sack_proc_short);
2872 	counter_u64_free(rack_enter_tlp_calc);
2873 	counter_u64_free(rack_used_tlpmethod);
2874 	counter_u64_free(rack_used_tlpmethod2);
2875 	counter_u64_free(rack_sack_skipped_acked);
2876 	counter_u64_free(rack_sack_splits);
2877 	counter_u64_free(rack_progress_drops);
2878 	counter_u64_free(rack_input_idle_reduces);
2879 	counter_u64_free(rack_collapsed_win);
2880 	counter_u64_free(rack_tlp_does_nada);
2881 	counter_u64_free(rack_try_scwnd);
2882 	counter_u64_free(rack_per_timer_hole);
2883 	counter_u64_free(rack_large_ackcmp);
2884 	counter_u64_free(rack_small_ackcmp);
2885 #ifdef INVARIANTS
2886 	counter_u64_free(rack_adjust_map_bw);
2887 #endif
2888 	COUNTER_ARRAY_FREE(rack_out_size, TCP_MSS_ACCT_SIZE);
2889 	COUNTER_ARRAY_FREE(rack_opts_arry, RACK_OPTS_SIZE);
2890 }
2891 
2892 static struct rack_sendmap *
2893 rack_alloc(struct tcp_rack *rack)
2894 {
2895 	struct rack_sendmap *rsm;
2896 
2897 	/*
2898 	 * First get the top of the list it in
2899 	 * theory is the "hottest" rsm we have,
2900 	 * possibly just freed by ack processing.
2901 	 */
2902 	if (rack->rc_free_cnt > rack_free_cache) {
2903 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
2904 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
2905 		counter_u64_add(rack_hot_alloc, 1);
2906 		rack->rc_free_cnt--;
2907 		return (rsm);
2908 	}
2909 	/*
2910 	 * Once we get under our free cache we probably
2911 	 * no longer have a "hot" one available. Lets
2912 	 * get one from UMA.
2913 	 */
2914 	rsm = uma_zalloc(rack_zone, M_NOWAIT);
2915 	if (rsm) {
2916 		rack->r_ctl.rc_num_maps_alloced++;
2917 		counter_u64_add(rack_to_alloc, 1);
2918 		return (rsm);
2919 	}
2920 	/*
2921 	 * Dig in to our aux rsm's (the last two) since
2922 	 * UMA failed to get us one.
2923 	 */
2924 	if (rack->rc_free_cnt) {
2925 		counter_u64_add(rack_to_alloc_emerg, 1);
2926 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
2927 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
2928 		rack->rc_free_cnt--;
2929 		return (rsm);
2930 	}
2931 	return (NULL);
2932 }
2933 
2934 static struct rack_sendmap *
2935 rack_alloc_full_limit(struct tcp_rack *rack)
2936 {
2937 	if ((V_tcp_map_entries_limit > 0) &&
2938 	    (rack->do_detection == 0) &&
2939 	    (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
2940 		counter_u64_add(rack_to_alloc_limited, 1);
2941 		if (!rack->alloc_limit_reported) {
2942 			rack->alloc_limit_reported = 1;
2943 			counter_u64_add(rack_alloc_limited_conns, 1);
2944 		}
2945 		return (NULL);
2946 	}
2947 	return (rack_alloc(rack));
2948 }
2949 
2950 /* wrapper to allocate a sendmap entry, subject to a specific limit */
2951 static struct rack_sendmap *
2952 rack_alloc_limit(struct tcp_rack *rack, uint8_t limit_type)
2953 {
2954 	struct rack_sendmap *rsm;
2955 
2956 	if (limit_type) {
2957 		/* currently there is only one limit type */
2958 		if (V_tcp_map_split_limit > 0 &&
2959 		    (rack->do_detection == 0) &&
2960 		    rack->r_ctl.rc_num_split_allocs >= V_tcp_map_split_limit) {
2961 			counter_u64_add(rack_split_limited, 1);
2962 			if (!rack->alloc_limit_reported) {
2963 				rack->alloc_limit_reported = 1;
2964 				counter_u64_add(rack_alloc_limited_conns, 1);
2965 			}
2966 			return (NULL);
2967 		}
2968 	}
2969 
2970 	/* allocate and mark in the limit type, if set */
2971 	rsm = rack_alloc(rack);
2972 	if (rsm != NULL && limit_type) {
2973 		rsm->r_limit_type = limit_type;
2974 		rack->r_ctl.rc_num_split_allocs++;
2975 	}
2976 	return (rsm);
2977 }
2978 
2979 static void
2980 rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm)
2981 {
2982 	if (rsm->r_flags & RACK_APP_LIMITED) {
2983 		if (rack->r_ctl.rc_app_limited_cnt > 0) {
2984 			rack->r_ctl.rc_app_limited_cnt--;
2985 		}
2986 	}
2987 	if (rsm->r_limit_type) {
2988 		/* currently there is only one limit type */
2989 		rack->r_ctl.rc_num_split_allocs--;
2990 	}
2991 	if (rsm == rack->r_ctl.rc_first_appl) {
2992 		if (rack->r_ctl.rc_app_limited_cnt == 0)
2993 			rack->r_ctl.rc_first_appl = NULL;
2994 		else {
2995 			/* Follow the next one out */
2996 			struct rack_sendmap fe;
2997 
2998 			fe.r_start = rsm->r_nseq_appl;
2999 			rack->r_ctl.rc_first_appl = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
3000 		}
3001 	}
3002 	if (rsm == rack->r_ctl.rc_resend)
3003 		rack->r_ctl.rc_resend = NULL;
3004 	if (rsm == rack->r_ctl.rc_rsm_at_retran)
3005 		rack->r_ctl.rc_rsm_at_retran = NULL;
3006 	if (rsm == rack->r_ctl.rc_end_appl)
3007 		rack->r_ctl.rc_end_appl = NULL;
3008 	if (rack->r_ctl.rc_tlpsend == rsm)
3009 		rack->r_ctl.rc_tlpsend = NULL;
3010 	if (rack->r_ctl.rc_sacklast == rsm)
3011 		rack->r_ctl.rc_sacklast = NULL;
3012 	memset(rsm, 0, sizeof(struct rack_sendmap));
3013 	TAILQ_INSERT_HEAD(&rack->r_ctl.rc_free, rsm, r_tnext);
3014 	rack->rc_free_cnt++;
3015 }
3016 
3017 static void
3018 rack_free_trim(struct tcp_rack *rack)
3019 {
3020 	struct rack_sendmap *rsm;
3021 
3022 	/*
3023 	 * Free up all the tail entries until
3024 	 * we get our list down to the limit.
3025 	 */
3026 	while (rack->rc_free_cnt > rack_free_cache) {
3027 		rsm = TAILQ_LAST(&rack->r_ctl.rc_free, rack_head);
3028 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
3029 		rack->rc_free_cnt--;
3030 		uma_zfree(rack_zone, rsm);
3031 	}
3032 }
3033 
3034 
3035 static uint32_t
3036 rack_get_measure_window(struct tcpcb *tp, struct tcp_rack *rack)
3037 {
3038 	uint64_t srtt, bw, len, tim;
3039 	uint32_t segsiz, def_len, minl;
3040 
3041 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
3042 	def_len = rack_def_data_window * segsiz;
3043 	if (rack->rc_gp_filled == 0) {
3044 		/*
3045 		 * We have no measurement (IW is in flight?) so
3046 		 * we can only guess using our data_window sysctl
3047 		 * value (usually 100MSS).
3048 		 */
3049 		return (def_len);
3050 	}
3051 	/*
3052 	 * Now we have a number of factors to consider.
3053 	 *
3054 	 * 1) We have a desired BDP which is usually
3055 	 *    at least 2.
3056 	 * 2) We have a minimum number of rtt's usually 1 SRTT
3057 	 *    but we allow it too to be more.
3058 	 * 3) We want to make sure a measurement last N useconds (if
3059 	 *    we have set rack_min_measure_usec.
3060 	 *
3061 	 * We handle the first concern here by trying to create a data
3062 	 * window of max(rack_def_data_window, DesiredBDP). The
3063 	 * second concern we handle in not letting the measurement
3064 	 * window end normally until at least the required SRTT's
3065 	 * have gone by which is done further below in
3066 	 * rack_enough_for_measurement(). Finally the third concern
3067 	 * we also handle here by calculating how long that time
3068 	 * would take at the current BW and then return the
3069 	 * max of our first calculation and that length. Note
3070 	 * that if rack_min_measure_usec is 0, we don't deal
3071 	 * with concern 3. Also for both Concern 1 and 3 an
3072 	 * application limited period could end the measurement
3073 	 * earlier.
3074 	 *
3075 	 * So lets calculate the BDP with the "known" b/w using
3076 	 * the SRTT has our rtt and then multiply it by the
3077 	 * goal.
3078 	 */
3079 	bw = rack_get_bw(rack);
3080 	srtt = (uint64_t)tp->t_srtt;
3081 	len = bw * srtt;
3082 	len /= (uint64_t)HPTS_USEC_IN_SEC;
3083 	len *= max(1, rack_goal_bdp);
3084 	/* Now we need to round up to the nearest MSS */
3085 	len = roundup(len, segsiz);
3086 	if (rack_min_measure_usec) {
3087 		/* Now calculate our min length for this b/w */
3088 		tim = rack_min_measure_usec;
3089 		minl = (tim * bw) / (uint64_t)HPTS_USEC_IN_SEC;
3090 		if (minl == 0)
3091 			minl = 1;
3092 		minl = roundup(minl, segsiz);
3093 		if (len < minl)
3094 			len = minl;
3095 	}
3096 	/*
3097 	 * Now if we have a very small window we want
3098 	 * to attempt to get the window that is
3099 	 * as small as possible. This happens on
3100 	 * low b/w connections and we don't want to
3101 	 * span huge numbers of rtt's between measurements.
3102 	 *
3103 	 * We basically include 2 over our "MIN window" so
3104 	 * that the measurement can be shortened (possibly) by
3105 	 * an ack'ed packet.
3106 	 */
3107 	if (len < def_len)
3108 		return (max((uint32_t)len, ((MIN_GP_WIN+2) * segsiz)));
3109 	else
3110 		return (max((uint32_t)len, def_len));
3111 
3112 }
3113 
3114 static int
3115 rack_enough_for_measurement(struct tcpcb *tp, struct tcp_rack *rack, tcp_seq th_ack)
3116 {
3117 	uint32_t tim, srtts, segsiz;
3118 
3119 	/*
3120 	 * Has enough time passed for the GP measurement to be valid?
3121 	 */
3122 	if ((tp->snd_max == tp->snd_una) ||
3123 	    (th_ack == tp->snd_max)){
3124 		/* All is acked */
3125 		return (1);
3126 	}
3127 	if (SEQ_LT(th_ack, tp->gput_seq)) {
3128 		/* Not enough bytes yet */
3129 		return (0);
3130 	}
3131 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
3132 	if (SEQ_LT(th_ack, tp->gput_ack) &&
3133 	    ((th_ack - tp->gput_seq) < max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
3134 		/* Not enough bytes yet */
3135 		return (0);
3136 	}
3137 	if (rack->r_ctl.rc_first_appl &&
3138 	    (rack->r_ctl.rc_first_appl->r_start == th_ack)) {
3139 		/*
3140 		 * We are up to the app limited point
3141 		 * we have to measure irrespective of the time..
3142 		 */
3143 		return (1);
3144 	}
3145 	/* Now what about time? */
3146 	srtts = (rack->r_ctl.rc_gp_srtt * rack_min_srtts);
3147 	tim = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - tp->gput_ts;
3148 	if (tim >= srtts) {
3149 		return (1);
3150 	}
3151 	/* Nope not even a full SRTT has passed */
3152 	return (0);
3153 }
3154 
3155 static void
3156 rack_log_timely(struct tcp_rack *rack,
3157 		uint32_t logged, uint64_t cur_bw, uint64_t low_bnd,
3158 		uint64_t up_bnd, int line, uint8_t method)
3159 {
3160 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
3161 		union tcp_log_stackspecific log;
3162 		struct timeval tv;
3163 
3164 		memset(&log, 0, sizeof(log));
3165 		log.u_bbr.flex1 = logged;
3166 		log.u_bbr.flex2 = rack->rc_gp_timely_inc_cnt;
3167 		log.u_bbr.flex2 <<= 4;
3168 		log.u_bbr.flex2 |= rack->rc_gp_timely_dec_cnt;
3169 		log.u_bbr.flex2 <<= 4;
3170 		log.u_bbr.flex2 |= rack->rc_gp_incr;
3171 		log.u_bbr.flex2 <<= 4;
3172 		log.u_bbr.flex2 |= rack->rc_gp_bwred;
3173 		log.u_bbr.flex3 = rack->rc_gp_incr;
3174 		log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
3175 		log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ca;
3176 		log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_rec;
3177 		log.u_bbr.flex7 = rack->rc_gp_bwred;
3178 		log.u_bbr.flex8 = method;
3179 		log.u_bbr.cur_del_rate = cur_bw;
3180 		log.u_bbr.delRate = low_bnd;
3181 		log.u_bbr.bw_inuse = up_bnd;
3182 		log.u_bbr.rttProp = rack_get_bw(rack);
3183 		log.u_bbr.pkt_epoch = line;
3184 		log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
3185 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3186 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3187 		log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
3188 		log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
3189 		log.u_bbr.cwnd_gain = rack->rc_dragged_bottom;
3190 		log.u_bbr.cwnd_gain <<= 1;
3191 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_rec;
3192 		log.u_bbr.cwnd_gain <<= 1;
3193 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
3194 		log.u_bbr.cwnd_gain <<= 1;
3195 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
3196 		log.u_bbr.lost = rack->r_ctl.rc_loss_count;
3197 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3198 		    &rack->rc_inp->inp_socket->so_rcv,
3199 		    &rack->rc_inp->inp_socket->so_snd,
3200 		    TCP_TIMELY_WORK, 0,
3201 		    0, &log, false, &tv);
3202 	}
3203 }
3204 
3205 static int
3206 rack_bw_can_be_raised(struct tcp_rack *rack, uint64_t cur_bw, uint64_t last_bw_est, uint16_t mult)
3207 {
3208 	/*
3209 	 * Before we increase we need to know if
3210 	 * the estimate just made was less than
3211 	 * our pacing goal (i.e. (cur_bw * mult) > last_bw_est)
3212 	 *
3213 	 * If we already are pacing at a fast enough
3214 	 * rate to push us faster there is no sense of
3215 	 * increasing.
3216 	 *
3217 	 * We first caculate our actual pacing rate (ss or ca multipler
3218 	 * times our cur_bw).
3219 	 *
3220 	 * Then we take the last measured rate and multipy by our
3221 	 * maximum pacing overage to give us a max allowable rate.
3222 	 *
3223 	 * If our act_rate is smaller than our max_allowable rate
3224 	 * then we should increase. Else we should hold steady.
3225 	 *
3226 	 */
3227 	uint64_t act_rate, max_allow_rate;
3228 
3229 	if (rack_timely_no_stopping)
3230 		return (1);
3231 
3232 	if ((cur_bw == 0) || (last_bw_est == 0)) {
3233 		/*
3234 		 * Initial startup case or
3235 		 * everything is acked case.
3236 		 */
3237 		rack_log_timely(rack,  mult, cur_bw, 0, 0,
3238 				__LINE__, 9);
3239 		return (1);
3240 	}
3241 	if (mult <= 100) {
3242 		/*
3243 		 * We can always pace at or slightly above our rate.
3244 		 */
3245 		rack_log_timely(rack,  mult, cur_bw, 0, 0,
3246 				__LINE__, 9);
3247 		return (1);
3248 	}
3249 	act_rate = cur_bw * (uint64_t)mult;
3250 	act_rate /= 100;
3251 	max_allow_rate = last_bw_est * ((uint64_t)rack_max_per_above + (uint64_t)100);
3252 	max_allow_rate /= 100;
3253 	if (act_rate < max_allow_rate) {
3254 		/*
3255 		 * Here the rate we are actually pacing at
3256 		 * is smaller than 10% above our last measurement.
3257 		 * This means we are pacing below what we would
3258 		 * like to try to achieve (plus some wiggle room).
3259 		 */
3260 		rack_log_timely(rack,  mult, cur_bw, act_rate, max_allow_rate,
3261 				__LINE__, 9);
3262 		return (1);
3263 	} else {
3264 		/*
3265 		 * Here we are already pacing at least rack_max_per_above(10%)
3266 		 * what we are getting back. This indicates most likely
3267 		 * that we are being limited (cwnd/rwnd/app) and can't
3268 		 * get any more b/w. There is no sense of trying to
3269 		 * raise up the pacing rate its not speeding us up
3270 		 * and we already are pacing faster than we are getting.
3271 		 */
3272 		rack_log_timely(rack,  mult, cur_bw, act_rate, max_allow_rate,
3273 				__LINE__, 8);
3274 		return (0);
3275 	}
3276 }
3277 
3278 static void
3279 rack_validate_multipliers_at_or_above100(struct tcp_rack *rack)
3280 {
3281 	/*
3282 	 * When we drag bottom, we want to assure
3283 	 * that no multiplier is below 1.0, if so
3284 	 * we want to restore it to at least that.
3285 	 */
3286 	if (rack->r_ctl.rack_per_of_gp_rec  < 100) {
3287 		/* This is unlikely we usually do not touch recovery */
3288 		rack->r_ctl.rack_per_of_gp_rec = 100;
3289 	}
3290 	if (rack->r_ctl.rack_per_of_gp_ca < 100) {
3291 		rack->r_ctl.rack_per_of_gp_ca = 100;
3292 	}
3293 	if (rack->r_ctl.rack_per_of_gp_ss < 100) {
3294 		rack->r_ctl.rack_per_of_gp_ss = 100;
3295 	}
3296 }
3297 
3298 static void
3299 rack_validate_multipliers_at_or_below_100(struct tcp_rack *rack)
3300 {
3301 	if (rack->r_ctl.rack_per_of_gp_ca > 100) {
3302 		rack->r_ctl.rack_per_of_gp_ca = 100;
3303 	}
3304 	if (rack->r_ctl.rack_per_of_gp_ss > 100) {
3305 		rack->r_ctl.rack_per_of_gp_ss = 100;
3306 	}
3307 }
3308 
3309 static void
3310 rack_increase_bw_mul(struct tcp_rack *rack, int timely_says, uint64_t cur_bw, uint64_t last_bw_est, int override)
3311 {
3312 	int32_t  calc, logged, plus;
3313 
3314 	logged = 0;
3315 
3316 	if (override) {
3317 		/*
3318 		 * override is passed when we are
3319 		 * loosing b/w and making one last
3320 		 * gasp at trying to not loose out
3321 		 * to a new-reno flow.
3322 		 */
3323 		goto extra_boost;
3324 	}
3325 	/* In classic timely we boost by 5x if we have 5 increases in a row, lets not */
3326 	if (rack->rc_gp_incr &&
3327 	    ((rack->rc_gp_timely_inc_cnt + 1) >= RACK_TIMELY_CNT_BOOST)) {
3328 		/*
3329 		 * Reset and get 5 strokes more before the boost. Note
3330 		 * that the count is 0 based so we have to add one.
3331 		 */
3332 extra_boost:
3333 		plus = (uint32_t)rack_gp_increase_per * RACK_TIMELY_CNT_BOOST;
3334 		rack->rc_gp_timely_inc_cnt = 0;
3335 	} else
3336 		plus = (uint32_t)rack_gp_increase_per;
3337 	/* Must be at least 1% increase for true timely increases */
3338 	if ((plus < 1) &&
3339 	    ((rack->r_ctl.rc_rtt_diff <= 0) || (timely_says <= 0)))
3340 		plus = 1;
3341 	if (rack->rc_gp_saw_rec &&
3342 	    (rack->rc_gp_no_rec_chg == 0) &&
3343 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3344 				  rack->r_ctl.rack_per_of_gp_rec)) {
3345 		/* We have been in recovery ding it too */
3346 		calc = rack->r_ctl.rack_per_of_gp_rec + plus;
3347 		if (calc > 0xffff)
3348 			calc = 0xffff;
3349 		logged |= 1;
3350 		rack->r_ctl.rack_per_of_gp_rec = (uint16_t)calc;
3351 		if (rack_per_upper_bound_ss &&
3352 		    (rack->rc_dragged_bottom == 0) &&
3353 		    (rack->r_ctl.rack_per_of_gp_rec > rack_per_upper_bound_ss))
3354 			rack->r_ctl.rack_per_of_gp_rec = rack_per_upper_bound_ss;
3355 	}
3356 	if (rack->rc_gp_saw_ca &&
3357 	    (rack->rc_gp_saw_ss == 0) &&
3358 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3359 				  rack->r_ctl.rack_per_of_gp_ca)) {
3360 		/* In CA */
3361 		calc = rack->r_ctl.rack_per_of_gp_ca + plus;
3362 		if (calc > 0xffff)
3363 			calc = 0xffff;
3364 		logged |= 2;
3365 		rack->r_ctl.rack_per_of_gp_ca = (uint16_t)calc;
3366 		if (rack_per_upper_bound_ca &&
3367 		    (rack->rc_dragged_bottom == 0) &&
3368 		    (rack->r_ctl.rack_per_of_gp_ca > rack_per_upper_bound_ca))
3369 			rack->r_ctl.rack_per_of_gp_ca = rack_per_upper_bound_ca;
3370 	}
3371 	if (rack->rc_gp_saw_ss &&
3372 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3373 				  rack->r_ctl.rack_per_of_gp_ss)) {
3374 		/* In SS */
3375 		calc = rack->r_ctl.rack_per_of_gp_ss + plus;
3376 		if (calc > 0xffff)
3377 			calc = 0xffff;
3378 		rack->r_ctl.rack_per_of_gp_ss = (uint16_t)calc;
3379 		if (rack_per_upper_bound_ss &&
3380 		    (rack->rc_dragged_bottom == 0) &&
3381 		    (rack->r_ctl.rack_per_of_gp_ss > rack_per_upper_bound_ss))
3382 			rack->r_ctl.rack_per_of_gp_ss = rack_per_upper_bound_ss;
3383 		logged |= 4;
3384 	}
3385 	if (logged &&
3386 	    (rack->rc_gp_incr == 0)){
3387 		/* Go into increment mode */
3388 		rack->rc_gp_incr = 1;
3389 		rack->rc_gp_timely_inc_cnt = 0;
3390 	}
3391 	if (rack->rc_gp_incr &&
3392 	    logged &&
3393 	    (rack->rc_gp_timely_inc_cnt < RACK_TIMELY_CNT_BOOST)) {
3394 		rack->rc_gp_timely_inc_cnt++;
3395 	}
3396 	rack_log_timely(rack,  logged, plus, 0, 0,
3397 			__LINE__, 1);
3398 }
3399 
3400 static uint32_t
3401 rack_get_decrease(struct tcp_rack *rack, uint32_t curper, int32_t rtt_diff)
3402 {
3403 	/*
3404 	 * norm_grad = rtt_diff / minrtt;
3405 	 * new_per = curper * (1 - B * norm_grad)
3406 	 *
3407 	 * B = rack_gp_decrease_per (default 10%)
3408 	 * rtt_dif = input var current rtt-diff
3409 	 * curper = input var current percentage
3410 	 * minrtt = from rack filter
3411 	 *
3412 	 */
3413 	uint64_t perf;
3414 
3415 	perf = (((uint64_t)curper * ((uint64_t)1000000 -
3416 		    ((uint64_t)rack_gp_decrease_per * (uint64_t)10000 *
3417 		     (((uint64_t)rtt_diff * (uint64_t)1000000)/
3418 		      (uint64_t)get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt)))/
3419 		     (uint64_t)1000000)) /
3420 		(uint64_t)1000000);
3421 	if (perf > curper) {
3422 		/* TSNH */
3423 		perf = curper - 1;
3424 	}
3425 	return ((uint32_t)perf);
3426 }
3427 
3428 static uint32_t
3429 rack_decrease_highrtt(struct tcp_rack *rack, uint32_t curper, uint32_t rtt)
3430 {
3431 	/*
3432 	 *                                   highrttthresh
3433 	 * result = curper * (1 - (B * ( 1 -  ------          ))
3434 	 *                                     gp_srtt
3435 	 *
3436 	 * B = rack_gp_decrease_per (default 10%)
3437 	 * highrttthresh = filter_min * rack_gp_rtt_maxmul
3438 	 */
3439 	uint64_t perf;
3440 	uint32_t highrttthresh;
3441 
3442 	highrttthresh = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
3443 
3444 	perf = (((uint64_t)curper * ((uint64_t)1000000 -
3445 				     ((uint64_t)rack_gp_decrease_per * ((uint64_t)1000000 -
3446 					((uint64_t)highrttthresh * (uint64_t)1000000) /
3447 						    (uint64_t)rtt)) / 100)) /(uint64_t)1000000);
3448 	return (perf);
3449 }
3450 
3451 static void
3452 rack_decrease_bw_mul(struct tcp_rack *rack, int timely_says, uint32_t rtt, int32_t rtt_diff)
3453 {
3454 	uint64_t logvar, logvar2, logvar3;
3455 	uint32_t logged, new_per, ss_red, ca_red, rec_red, alt, val;
3456 
3457 	if (rack->rc_gp_incr) {
3458 		/* Turn off increment counting */
3459 		rack->rc_gp_incr = 0;
3460 		rack->rc_gp_timely_inc_cnt = 0;
3461 	}
3462 	ss_red = ca_red = rec_red = 0;
3463 	logged = 0;
3464 	/* Calculate the reduction value */
3465 	if (rtt_diff < 0) {
3466 		rtt_diff *= -1;
3467 	}
3468 	/* Must be at least 1% reduction */
3469 	if (rack->rc_gp_saw_rec && (rack->rc_gp_no_rec_chg == 0)) {
3470 		/* We have been in recovery ding it too */
3471 		if (timely_says == 2) {
3472 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_rec, rtt);
3473 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3474 			if (alt < new_per)
3475 				val = alt;
3476 			else
3477 				val = new_per;
3478 		} else
3479 			 val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3480 		if (rack->r_ctl.rack_per_of_gp_rec > val) {
3481 			rec_red = (rack->r_ctl.rack_per_of_gp_rec - val);
3482 			rack->r_ctl.rack_per_of_gp_rec = (uint16_t)val;
3483 		} else {
3484 			rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
3485 			rec_red = 0;
3486 		}
3487 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_rec)
3488 			rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
3489 		logged |= 1;
3490 	}
3491 	if (rack->rc_gp_saw_ss) {
3492 		/* Sent in SS */
3493 		if (timely_says == 2) {
3494 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ss, rtt);
3495 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3496 			if (alt < new_per)
3497 				val = alt;
3498 			else
3499 				val = new_per;
3500 		} else
3501 			val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ss, rtt_diff);
3502 		if (rack->r_ctl.rack_per_of_gp_ss > new_per) {
3503 			ss_red = rack->r_ctl.rack_per_of_gp_ss - val;
3504 			rack->r_ctl.rack_per_of_gp_ss = (uint16_t)val;
3505 		} else {
3506 			ss_red = new_per;
3507 			rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
3508 			logvar = new_per;
3509 			logvar <<= 32;
3510 			logvar |= alt;
3511 			logvar2 = (uint32_t)rtt;
3512 			logvar2 <<= 32;
3513 			logvar2 |= (uint32_t)rtt_diff;
3514 			logvar3 = rack_gp_rtt_maxmul;
3515 			logvar3 <<= 32;
3516 			logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3517 			rack_log_timely(rack, timely_says,
3518 					logvar2, logvar3,
3519 					logvar, __LINE__, 10);
3520 		}
3521 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ss)
3522 			rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
3523 		logged |= 4;
3524 	} else if (rack->rc_gp_saw_ca) {
3525 		/* Sent in CA */
3526 		if (timely_says == 2) {
3527 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ca, rtt);
3528 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3529 			if (alt < new_per)
3530 				val = alt;
3531 			else
3532 				val = new_per;
3533 		} else
3534 			val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ca, rtt_diff);
3535 		if (rack->r_ctl.rack_per_of_gp_ca > val) {
3536 			ca_red = rack->r_ctl.rack_per_of_gp_ca - val;
3537 			rack->r_ctl.rack_per_of_gp_ca = (uint16_t)val;
3538 		} else {
3539 			rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
3540 			ca_red = 0;
3541 			logvar = new_per;
3542 			logvar <<= 32;
3543 			logvar |= alt;
3544 			logvar2 = (uint32_t)rtt;
3545 			logvar2 <<= 32;
3546 			logvar2 |= (uint32_t)rtt_diff;
3547 			logvar3 = rack_gp_rtt_maxmul;
3548 			logvar3 <<= 32;
3549 			logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3550 			rack_log_timely(rack, timely_says,
3551 					logvar2, logvar3,
3552 					logvar, __LINE__, 10);
3553 		}
3554 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ca)
3555 			rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
3556 		logged |= 2;
3557 	}
3558 	if (rack->rc_gp_timely_dec_cnt < 0x7) {
3559 		rack->rc_gp_timely_dec_cnt++;
3560 		if (rack_timely_dec_clear &&
3561 		    (rack->rc_gp_timely_dec_cnt == rack_timely_dec_clear))
3562 			rack->rc_gp_timely_dec_cnt = 0;
3563 	}
3564 	logvar = ss_red;
3565 	logvar <<= 32;
3566 	logvar |= ca_red;
3567 	rack_log_timely(rack,  logged, rec_red, rack_per_lower_bound, logvar,
3568 			__LINE__, 2);
3569 }
3570 
3571 static void
3572 rack_log_rtt_shrinks(struct tcp_rack *rack, uint32_t us_cts,
3573 		     uint32_t rtt, uint32_t line, uint8_t reas)
3574 {
3575 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
3576 		union tcp_log_stackspecific log;
3577 		struct timeval tv;
3578 
3579 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3580 		log.u_bbr.flex1 = line;
3581 		log.u_bbr.flex2 = rack->r_ctl.rc_time_probertt_starts;
3582 		log.u_bbr.flex3 = rack->r_ctl.rc_lower_rtt_us_cts;
3583 		log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
3584 		log.u_bbr.flex5 = rtt;
3585 		log.u_bbr.flex6 = rack->rc_highly_buffered;
3586 		log.u_bbr.flex6 <<= 1;
3587 		log.u_bbr.flex6 |= rack->forced_ack;
3588 		log.u_bbr.flex6 <<= 1;
3589 		log.u_bbr.flex6 |= rack->rc_gp_dyn_mul;
3590 		log.u_bbr.flex6 <<= 1;
3591 		log.u_bbr.flex6 |= rack->in_probe_rtt;
3592 		log.u_bbr.flex6 <<= 1;
3593 		log.u_bbr.flex6 |= rack->measure_saw_probe_rtt;
3594 		log.u_bbr.flex7 = rack->r_ctl.rack_per_of_gp_probertt;
3595 		log.u_bbr.pacing_gain = rack->r_ctl.rack_per_of_gp_ca;
3596 		log.u_bbr.cwnd_gain = rack->r_ctl.rack_per_of_gp_rec;
3597 		log.u_bbr.flex8 = reas;
3598 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3599 		log.u_bbr.delRate = rack_get_bw(rack);
3600 		log.u_bbr.cur_del_rate = rack->r_ctl.rc_highest_us_rtt;
3601 		log.u_bbr.cur_del_rate <<= 32;
3602 		log.u_bbr.cur_del_rate |= rack->r_ctl.rc_lowest_us_rtt;
3603 		log.u_bbr.applimited = rack->r_ctl.rc_time_probertt_entered;
3604 		log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
3605 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3606 		log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
3607 		log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
3608 		log.u_bbr.pkt_epoch = rack->r_ctl.rc_lower_rtt_us_cts;
3609 		log.u_bbr.delivered = rack->r_ctl.rc_target_probertt_flight;
3610 		log.u_bbr.lost = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3611 		log.u_bbr.rttProp = us_cts;
3612 		log.u_bbr.rttProp <<= 32;
3613 		log.u_bbr.rttProp |= rack->r_ctl.rc_entry_gp_rtt;
3614 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3615 		    &rack->rc_inp->inp_socket->so_rcv,
3616 		    &rack->rc_inp->inp_socket->so_snd,
3617 		    BBR_LOG_RTT_SHRINKS, 0,
3618 		    0, &log, false, &rack->r_ctl.act_rcv_time);
3619 	}
3620 }
3621 
3622 static void
3623 rack_set_prtt_target(struct tcp_rack *rack, uint32_t segsiz, uint32_t rtt)
3624 {
3625 	uint64_t bwdp;
3626 
3627 	bwdp = rack_get_bw(rack);
3628 	bwdp *= (uint64_t)rtt;
3629 	bwdp /= (uint64_t)HPTS_USEC_IN_SEC;
3630 	rack->r_ctl.rc_target_probertt_flight = roundup((uint32_t)bwdp, segsiz);
3631 	if (rack->r_ctl.rc_target_probertt_flight < (segsiz * rack_timely_min_segs)) {
3632 		/*
3633 		 * A window protocol must be able to have 4 packets
3634 		 * outstanding as the floor in order to function
3635 		 * (especially considering delayed ack :D).
3636 		 */
3637 		rack->r_ctl.rc_target_probertt_flight = (segsiz * rack_timely_min_segs);
3638 	}
3639 }
3640 
3641 static void
3642 rack_enter_probertt(struct tcp_rack *rack, uint32_t us_cts)
3643 {
3644 	/**
3645 	 * ProbeRTT is a bit different in rack_pacing than in
3646 	 * BBR. It is like BBR in that it uses the lowering of
3647 	 * the RTT as a signal that we saw something new and
3648 	 * counts from there for how long between. But it is
3649 	 * different in that its quite simple. It does not
3650 	 * play with the cwnd and wait until we get down
3651 	 * to N segments outstanding and hold that for
3652 	 * 200ms. Instead it just sets the pacing reduction
3653 	 * rate to a set percentage (70 by default) and hold
3654 	 * that for a number of recent GP Srtt's.
3655 	 */
3656 	uint32_t segsiz;
3657 
3658 	if (rack->rc_gp_dyn_mul == 0)
3659 		return;
3660 
3661 	if (rack->rc_tp->snd_max == rack->rc_tp->snd_una) {
3662 		/* We are idle */
3663 		return;
3664 	}
3665 	if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
3666 	    SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
3667 		/*
3668 		 * Stop the goodput now, the idea here is
3669 		 * that future measurements with in_probe_rtt
3670 		 * won't register if they are not greater so
3671 		 * we want to get what info (if any) is available
3672 		 * now.
3673 		 */
3674 		rack_do_goodput_measurement(rack->rc_tp, rack,
3675 					    rack->rc_tp->snd_una, __LINE__);
3676 	}
3677 	rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
3678 	rack->r_ctl.rc_time_probertt_entered = us_cts;
3679 	segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
3680 		     rack->r_ctl.rc_pace_min_segs);
3681 	rack->in_probe_rtt = 1;
3682 	rack->measure_saw_probe_rtt = 1;
3683 	rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
3684 	rack->r_ctl.rc_time_probertt_starts = 0;
3685 	rack->r_ctl.rc_entry_gp_rtt = rack->r_ctl.rc_gp_srtt;
3686 	if (rack_probertt_use_min_rtt_entry)
3687 		rack_set_prtt_target(rack, segsiz, get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
3688 	else
3689 		rack_set_prtt_target(rack, segsiz, rack->r_ctl.rc_gp_srtt);
3690 	rack_log_rtt_shrinks(rack,  us_cts,  get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3691 			     __LINE__, RACK_RTTS_ENTERPROBE);
3692 }
3693 
3694 static void
3695 rack_exit_probertt(struct tcp_rack *rack, uint32_t us_cts)
3696 {
3697 	struct rack_sendmap *rsm;
3698 	uint32_t segsiz;
3699 
3700 	segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
3701 		     rack->r_ctl.rc_pace_min_segs);
3702 	rack->in_probe_rtt = 0;
3703 	if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
3704 	    SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
3705 		/*
3706 		 * Stop the goodput now, the idea here is
3707 		 * that future measurements with in_probe_rtt
3708 		 * won't register if they are not greater so
3709 		 * we want to get what info (if any) is available
3710 		 * now.
3711 		 */
3712 		rack_do_goodput_measurement(rack->rc_tp, rack,
3713 					    rack->rc_tp->snd_una, __LINE__);
3714 	} else if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
3715 		/*
3716 		 * We don't have enough data to make a measurement.
3717 		 * So lets just stop and start here after exiting
3718 		 * probe-rtt. We probably are not interested in
3719 		 * the results anyway.
3720 		 */
3721 		rack->rc_tp->t_flags &= ~TF_GPUTINPROG;
3722 	}
3723 	/*
3724 	 * Measurements through the current snd_max are going
3725 	 * to be limited by the slower pacing rate.
3726 	 *
3727 	 * We need to mark these as app-limited so we
3728 	 * don't collapse the b/w.
3729 	 */
3730 	rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
3731 	if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
3732 		if (rack->r_ctl.rc_app_limited_cnt == 0)
3733 			rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
3734 		else {
3735 			/*
3736 			 * Go out to the end app limited and mark
3737 			 * this new one as next and move the end_appl up
3738 			 * to this guy.
3739 			 */
3740 			if (rack->r_ctl.rc_end_appl)
3741 				rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
3742 			rack->r_ctl.rc_end_appl = rsm;
3743 		}
3744 		rsm->r_flags |= RACK_APP_LIMITED;
3745 		rack->r_ctl.rc_app_limited_cnt++;
3746 	}
3747 	/*
3748 	 * Now, we need to examine our pacing rate multipliers.
3749 	 * If its under 100%, we need to kick it back up to
3750 	 * 100%. We also don't let it be over our "max" above
3751 	 * the actual rate i.e. 100% + rack_clamp_atexit_prtt.
3752 	 * Note setting clamp_atexit_prtt to 0 has the effect
3753 	 * of setting CA/SS to 100% always at exit (which is
3754 	 * the default behavior).
3755 	 */
3756 	if (rack_probertt_clear_is) {
3757 		rack->rc_gp_incr = 0;
3758 		rack->rc_gp_bwred = 0;
3759 		rack->rc_gp_timely_inc_cnt = 0;
3760 		rack->rc_gp_timely_dec_cnt = 0;
3761 	}
3762 	/* Do we do any clamping at exit? */
3763 	if (rack->rc_highly_buffered && rack_atexit_prtt_hbp) {
3764 		rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt_hbp;
3765 		rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt_hbp;
3766 	}
3767 	if ((rack->rc_highly_buffered == 0) && rack_atexit_prtt) {
3768 		rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt;
3769 		rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt;
3770 	}
3771 	/*
3772 	 * Lets set rtt_diff to 0, so that we will get a "boost"
3773 	 * after exiting.
3774 	 */
3775 	rack->r_ctl.rc_rtt_diff = 0;
3776 
3777 	/* Clear all flags so we start fresh */
3778 	rack->rc_tp->t_bytes_acked = 0;
3779 	rack->rc_tp->ccv->flags &= ~CCF_ABC_SENTAWND;
3780 	/*
3781 	 * If configured to, set the cwnd and ssthresh to
3782 	 * our targets.
3783 	 */
3784 	if (rack_probe_rtt_sets_cwnd) {
3785 		uint64_t ebdp;
3786 		uint32_t setto;
3787 
3788 		/* Set ssthresh so we get into CA once we hit our target */
3789 		if (rack_probertt_use_min_rtt_exit == 1) {
3790 			/* Set to min rtt */
3791 			rack_set_prtt_target(rack, segsiz,
3792 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
3793 		} else if (rack_probertt_use_min_rtt_exit == 2) {
3794 			/* Set to current gp rtt */
3795 			rack_set_prtt_target(rack, segsiz,
3796 					     rack->r_ctl.rc_gp_srtt);
3797 		} else if (rack_probertt_use_min_rtt_exit == 3) {
3798 			/* Set to entry gp rtt */
3799 			rack_set_prtt_target(rack, segsiz,
3800 					     rack->r_ctl.rc_entry_gp_rtt);
3801 		} else {
3802 			uint64_t sum;
3803 			uint32_t setval;
3804 
3805 			sum = rack->r_ctl.rc_entry_gp_rtt;
3806 			sum *= 10;
3807 			sum /= (uint64_t)(max(1, rack->r_ctl.rc_gp_srtt));
3808 			if (sum >= 20) {
3809 				/*
3810 				 * A highly buffered path needs
3811 				 * cwnd space for timely to work.
3812 				 * Lets set things up as if
3813 				 * we are heading back here again.
3814 				 */
3815 				setval = rack->r_ctl.rc_entry_gp_rtt;
3816 			} else if (sum >= 15) {
3817 				/*
3818 				 * Lets take the smaller of the
3819 				 * two since we are just somewhat
3820 				 * buffered.
3821 				 */
3822 				setval = rack->r_ctl.rc_gp_srtt;
3823 				if (setval > rack->r_ctl.rc_entry_gp_rtt)
3824 					setval = rack->r_ctl.rc_entry_gp_rtt;
3825 			} else {
3826 				/*
3827 				 * Here we are not highly buffered
3828 				 * and should pick the min we can to
3829 				 * keep from causing loss.
3830 				 */
3831 				setval = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3832 			}
3833 			rack_set_prtt_target(rack, segsiz,
3834 					     setval);
3835 		}
3836 		if (rack_probe_rtt_sets_cwnd > 1) {
3837 			/* There is a percentage here to boost */
3838 			ebdp = rack->r_ctl.rc_target_probertt_flight;
3839 			ebdp *= rack_probe_rtt_sets_cwnd;
3840 			ebdp /= 100;
3841 			setto = rack->r_ctl.rc_target_probertt_flight + ebdp;
3842 		} else
3843 			setto = rack->r_ctl.rc_target_probertt_flight;
3844 		rack->rc_tp->snd_cwnd = roundup(setto, segsiz);
3845 		if (rack->rc_tp->snd_cwnd < (segsiz * rack_timely_min_segs)) {
3846 			/* Enforce a min */
3847 			rack->rc_tp->snd_cwnd = segsiz * rack_timely_min_segs;
3848 		}
3849 		/* If we set in the cwnd also set the ssthresh point so we are in CA */
3850 		rack->rc_tp->snd_ssthresh = (rack->rc_tp->snd_cwnd - 1);
3851 	}
3852 	rack_log_rtt_shrinks(rack,  us_cts,
3853 			     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3854 			     __LINE__, RACK_RTTS_EXITPROBE);
3855 	/* Clear times last so log has all the info */
3856 	rack->r_ctl.rc_probertt_sndmax_atexit = rack->rc_tp->snd_max;
3857 	rack->r_ctl.rc_time_probertt_entered = us_cts;
3858 	rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
3859 	rack->r_ctl.rc_time_of_last_probertt = us_cts;
3860 }
3861 
3862 static void
3863 rack_check_probe_rtt(struct tcp_rack *rack, uint32_t us_cts)
3864 {
3865 	/* Check in on probe-rtt */
3866 	if (rack->rc_gp_filled == 0) {
3867 		/* We do not do p-rtt unless we have gp measurements */
3868 		return;
3869 	}
3870 	if (rack->in_probe_rtt) {
3871 		uint64_t no_overflow;
3872 		uint32_t endtime, must_stay;
3873 
3874 		if (rack->r_ctl.rc_went_idle_time &&
3875 		    ((us_cts - rack->r_ctl.rc_went_idle_time) > rack_min_probertt_hold)) {
3876 			/*
3877 			 * We went idle during prtt, just exit now.
3878 			 */
3879 			rack_exit_probertt(rack, us_cts);
3880 		} else if (rack_probe_rtt_safety_val &&
3881 		    TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered) &&
3882 		    ((us_cts - rack->r_ctl.rc_time_probertt_entered) > rack_probe_rtt_safety_val)) {
3883 			/*
3884 			 * Probe RTT safety value triggered!
3885 			 */
3886 			rack_log_rtt_shrinks(rack,  us_cts,
3887 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3888 					     __LINE__, RACK_RTTS_SAFETY);
3889 			rack_exit_probertt(rack, us_cts);
3890 		}
3891 		/* Calculate the max we will wait */
3892 		endtime = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_max_drain_wait);
3893 		if (rack->rc_highly_buffered)
3894 			endtime += (rack->r_ctl.rc_gp_srtt * rack_max_drain_hbp);
3895 		/* Calculate the min we must wait */
3896 		must_stay = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_must_drain);
3897 		if ((ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.rc_target_probertt_flight) &&
3898 		    TSTMP_LT(us_cts, endtime)) {
3899 			uint32_t calc;
3900 			/* Do we lower more? */
3901 no_exit:
3902 			if (TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered))
3903 				calc = us_cts - rack->r_ctl.rc_time_probertt_entered;
3904 			else
3905 				calc = 0;
3906 			calc /= max(rack->r_ctl.rc_gp_srtt, 1);
3907 			if (calc) {
3908 				/* Maybe */
3909 				calc *= rack_per_of_gp_probertt_reduce;
3910 				rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt - calc;
3911 				/* Limit it too */
3912 				if (rack->r_ctl.rack_per_of_gp_probertt < rack_per_of_gp_lowthresh)
3913 					rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_lowthresh;
3914 			}
3915 			/* We must reach target or the time set */
3916 			return;
3917 		}
3918 		if (rack->r_ctl.rc_time_probertt_starts == 0) {
3919 			if ((TSTMP_LT(us_cts, must_stay) &&
3920 			     rack->rc_highly_buffered) ||
3921 			     (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) >
3922 			      rack->r_ctl.rc_target_probertt_flight)) {
3923 				/* We are not past the must_stay time */
3924 				goto no_exit;
3925 			}
3926 			rack_log_rtt_shrinks(rack,  us_cts,
3927 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3928 					     __LINE__, RACK_RTTS_REACHTARGET);
3929 			rack->r_ctl.rc_time_probertt_starts = us_cts;
3930 			if (rack->r_ctl.rc_time_probertt_starts == 0)
3931 				rack->r_ctl.rc_time_probertt_starts = 1;
3932 			/* Restore back to our rate we want to pace at in prtt */
3933 			rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
3934 		}
3935 		/*
3936 		 * Setup our end time, some number of gp_srtts plus 200ms.
3937 		 */
3938 		no_overflow = ((uint64_t)rack->r_ctl.rc_gp_srtt *
3939 			       (uint64_t)rack_probertt_gpsrtt_cnt_mul);
3940 		if (rack_probertt_gpsrtt_cnt_div)
3941 			endtime = (uint32_t)(no_overflow / (uint64_t)rack_probertt_gpsrtt_cnt_div);
3942 		else
3943 			endtime = 0;
3944 		endtime += rack_min_probertt_hold;
3945 		endtime += rack->r_ctl.rc_time_probertt_starts;
3946 		if (TSTMP_GEQ(us_cts,  endtime)) {
3947 			/* yes, exit probertt */
3948 			rack_exit_probertt(rack, us_cts);
3949 		}
3950 
3951 	} else if ((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= rack_time_between_probertt) {
3952 		/* Go into probertt, its been too long since we went lower */
3953 		rack_enter_probertt(rack, us_cts);
3954 	}
3955 }
3956 
3957 static void
3958 rack_update_multiplier(struct tcp_rack *rack, int32_t timely_says, uint64_t last_bw_est,
3959 		       uint32_t rtt, int32_t rtt_diff)
3960 {
3961 	uint64_t cur_bw, up_bnd, low_bnd, subfr;
3962 	uint32_t losses;
3963 
3964 	if ((rack->rc_gp_dyn_mul == 0) ||
3965 	    (rack->use_fixed_rate) ||
3966 	    (rack->in_probe_rtt) ||
3967 	    (rack->rc_always_pace == 0)) {
3968 		/* No dynamic GP multipler in play */
3969 		return;
3970 	}
3971 	losses = rack->r_ctl.rc_loss_count - rack->r_ctl.rc_loss_at_start;
3972 	cur_bw = rack_get_bw(rack);
3973 	/* Calculate our up and down range */
3974 	up_bnd = rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_up;
3975 	up_bnd /= 100;
3976 	up_bnd += rack->r_ctl.last_gp_comp_bw;
3977 
3978 	subfr = (uint64_t)rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_down;
3979 	subfr /= 100;
3980 	low_bnd = rack->r_ctl.last_gp_comp_bw - subfr;
3981 	if ((timely_says == 2) && (rack->r_ctl.rc_no_push_at_mrtt)) {
3982 		/*
3983 		 * This is the case where our RTT is above
3984 		 * the max target and we have been configured
3985 		 * to just do timely no bonus up stuff in that case.
3986 		 *
3987 		 * There are two configurations, set to 1, and we
3988 		 * just do timely if we are over our max. If its
3989 		 * set above 1 then we slam the multipliers down
3990 		 * to 100 and then decrement per timely.
3991 		 */
3992 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
3993 				__LINE__, 3);
3994 		if (rack->r_ctl.rc_no_push_at_mrtt > 1)
3995 			rack_validate_multipliers_at_or_below_100(rack);
3996 		rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
3997 	} else if ((last_bw_est < low_bnd) && !losses) {
3998 		/*
3999 		 * We are decreasing this is a bit complicated this
4000 		 * means we are loosing ground. This could be
4001 		 * because another flow entered and we are competing
4002 		 * for b/w with it. This will push the RTT up which
4003 		 * makes timely unusable unless we want to get shoved
4004 		 * into a corner and just be backed off (the age
4005 		 * old problem with delay based CC).
4006 		 *
4007 		 * On the other hand if it was a route change we
4008 		 * would like to stay somewhat contained and not
4009 		 * blow out the buffers.
4010 		 */
4011 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4012 				__LINE__, 3);
4013 		rack->r_ctl.last_gp_comp_bw = cur_bw;
4014 		if (rack->rc_gp_bwred == 0) {
4015 			/* Go into reduction counting */
4016 			rack->rc_gp_bwred = 1;
4017 			rack->rc_gp_timely_dec_cnt = 0;
4018 		}
4019 		if ((rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) ||
4020 		    (timely_says == 0)) {
4021 			/*
4022 			 * Push another time with a faster pacing
4023 			 * to try to gain back (we include override to
4024 			 * get a full raise factor).
4025 			 */
4026 			if ((rack->rc_gp_saw_ca && rack->r_ctl.rack_per_of_gp_ca <= rack_down_raise_thresh) ||
4027 			    (rack->rc_gp_saw_ss && rack->r_ctl.rack_per_of_gp_ss <= rack_down_raise_thresh) ||
4028 			    (timely_says == 0) ||
4029 			    (rack_down_raise_thresh == 0)) {
4030 				/*
4031 				 * Do an override up in b/w if we were
4032 				 * below the threshold or if the threshold
4033 				 * is zero we always do the raise.
4034 				 */
4035 				rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 1);
4036 			} else {
4037 				/* Log it stays the same */
4038 				rack_log_timely(rack,  0, last_bw_est, low_bnd, 0,
4039 						__LINE__, 11);
4040 			}
4041 			rack->rc_gp_timely_dec_cnt++;
4042 			/* We are not incrementing really no-count */
4043 			rack->rc_gp_incr = 0;
4044 			rack->rc_gp_timely_inc_cnt = 0;
4045 		} else {
4046 			/*
4047 			 * Lets just use the RTT
4048 			 * information and give up
4049 			 * pushing.
4050 			 */
4051 			goto use_timely;
4052 		}
4053 	} else if ((timely_says != 2) &&
4054 		    !losses &&
4055 		    (last_bw_est > up_bnd)) {
4056 		/*
4057 		 * We are increasing b/w lets keep going, updating
4058 		 * our b/w and ignoring any timely input, unless
4059 		 * of course we are at our max raise (if there is one).
4060 		 */
4061 
4062 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4063 				__LINE__, 3);
4064 		rack->r_ctl.last_gp_comp_bw = cur_bw;
4065 		if (rack->rc_gp_saw_ss &&
4066 		    rack_per_upper_bound_ss &&
4067 		     (rack->r_ctl.rack_per_of_gp_ss == rack_per_upper_bound_ss)) {
4068 			    /*
4069 			     * In cases where we can't go higher
4070 			     * we should just use timely.
4071 			     */
4072 			    goto use_timely;
4073 		}
4074 		if (rack->rc_gp_saw_ca &&
4075 		    rack_per_upper_bound_ca &&
4076 		    (rack->r_ctl.rack_per_of_gp_ca == rack_per_upper_bound_ca)) {
4077 			    /*
4078 			     * In cases where we can't go higher
4079 			     * we should just use timely.
4080 			     */
4081 			    goto use_timely;
4082 		}
4083 		rack->rc_gp_bwred = 0;
4084 		rack->rc_gp_timely_dec_cnt = 0;
4085 		/* You get a set number of pushes if timely is trying to reduce */
4086 		if ((rack->rc_gp_incr < rack_timely_max_push_rise) || (timely_says == 0)) {
4087 			rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4088 		} else {
4089 			/* Log it stays the same */
4090 			rack_log_timely(rack,  0, last_bw_est, up_bnd, 0,
4091 			    __LINE__, 12);
4092 		}
4093 		return;
4094 	} else {
4095 		/*
4096 		 * We are staying between the lower and upper range bounds
4097 		 * so use timely to decide.
4098 		 */
4099 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
4100 				__LINE__, 3);
4101 use_timely:
4102 		if (timely_says) {
4103 			rack->rc_gp_incr = 0;
4104 			rack->rc_gp_timely_inc_cnt = 0;
4105 			if ((rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) &&
4106 			    !losses &&
4107 			    (last_bw_est < low_bnd)) {
4108 				/* We are loosing ground */
4109 				rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4110 				rack->rc_gp_timely_dec_cnt++;
4111 				/* We are not incrementing really no-count */
4112 				rack->rc_gp_incr = 0;
4113 				rack->rc_gp_timely_inc_cnt = 0;
4114 			} else
4115 				rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
4116 		} else {
4117 			rack->rc_gp_bwred = 0;
4118 			rack->rc_gp_timely_dec_cnt = 0;
4119 			rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4120 		}
4121 	}
4122 }
4123 
4124 static int32_t
4125 rack_make_timely_judgement(struct tcp_rack *rack, uint32_t rtt, int32_t rtt_diff, uint32_t prev_rtt)
4126 {
4127 	int32_t timely_says;
4128 	uint64_t log_mult, log_rtt_a_diff;
4129 
4130 	log_rtt_a_diff = rtt;
4131 	log_rtt_a_diff <<= 32;
4132 	log_rtt_a_diff |= (uint32_t)rtt_diff;
4133 	if (rtt >= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) *
4134 		    rack_gp_rtt_maxmul)) {
4135 		/* Reduce the b/w multipler */
4136 		timely_says = 2;
4137 		log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
4138 		log_mult <<= 32;
4139 		log_mult |= prev_rtt;
4140 		rack_log_timely(rack,  timely_says, log_mult,
4141 				get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4142 				log_rtt_a_diff, __LINE__, 4);
4143 	} else if (rtt <= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
4144 			   ((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
4145 			    max(rack_gp_rtt_mindiv , 1)))) {
4146 		/* Increase the b/w multipler */
4147 		log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
4148 			((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
4149 			 max(rack_gp_rtt_mindiv , 1));
4150 		log_mult <<= 32;
4151 		log_mult |= prev_rtt;
4152 		timely_says = 0;
4153 		rack_log_timely(rack,  timely_says, log_mult ,
4154 				get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4155 				log_rtt_a_diff, __LINE__, 5);
4156 	} else {
4157 		/*
4158 		 * Use a gradient to find it the timely gradient
4159 		 * is:
4160 		 * grad = rc_rtt_diff / min_rtt;
4161 		 *
4162 		 * anything below or equal to 0 will be
4163 		 * a increase indication. Anything above
4164 		 * zero is a decrease. Note we take care
4165 		 * of the actual gradient calculation
4166 		 * in the reduction (its not needed for
4167 		 * increase).
4168 		 */
4169 		log_mult = prev_rtt;
4170 		if (rtt_diff <= 0) {
4171 			/*
4172 			 * Rttdiff is less than zero, increase the
4173 			 * b/w multipler (its 0 or negative)
4174 			 */
4175 			timely_says = 0;
4176 			rack_log_timely(rack,  timely_says, log_mult,
4177 					get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 6);
4178 		} else {
4179 			/* Reduce the b/w multipler */
4180 			timely_says = 1;
4181 			rack_log_timely(rack,  timely_says, log_mult,
4182 					get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 7);
4183 		}
4184 	}
4185 	return (timely_says);
4186 }
4187 
4188 static void
4189 rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
4190 			    tcp_seq th_ack, int line)
4191 {
4192 	uint64_t tim, bytes_ps, ltim, stim, utim;
4193 	uint32_t segsiz, bytes, reqbytes, us_cts;
4194 	int32_t gput, new_rtt_diff, timely_says;
4195 	uint64_t  resid_bw, subpart = 0, addpart = 0, srtt;
4196 	int did_add = 0;
4197 
4198 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
4199 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
4200 	if (TSTMP_GEQ(us_cts, tp->gput_ts))
4201 		tim = us_cts - tp->gput_ts;
4202 	else
4203 		tim = 0;
4204 
4205 	if (rack->r_ctl.rc_gp_cumack_ts > rack->r_ctl.rc_gp_output_ts)
4206 		stim = rack->r_ctl.rc_gp_cumack_ts - rack->r_ctl.rc_gp_output_ts;
4207 	else
4208 		stim = 0;
4209 	/*
4210 	 * Use the larger of the send time or ack time. This prevents us
4211 	 * from being influenced by ack artifacts to come up with too
4212 	 * high of measurement. Note that since we are spanning over many more
4213 	 * bytes in most of our measurements hopefully that is less likely to
4214 	 * occur.
4215 	 */
4216 	if (tim > stim)
4217 		utim = max(tim, 1);
4218 	else
4219 		utim = max(stim, 1);
4220 	/* Lets get a msec time ltim too for the old stuff */
4221 	ltim = max(1, (utim / HPTS_USEC_IN_MSEC));
4222 	gput = (((uint64_t) (th_ack - tp->gput_seq)) << 3) / ltim;
4223 	reqbytes = min(rc_init_window(rack), (MIN_GP_WIN * segsiz));
4224 	if ((tim == 0) && (stim == 0)) {
4225 		/*
4226 		 * Invalid measurement time, maybe
4227 		 * all on one ack/one send?
4228 		 */
4229 		bytes = 0;
4230 		bytes_ps = 0;
4231 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4232 					   0, 0, 0, 10, __LINE__, NULL);
4233 		goto skip_measurement;
4234 	}
4235 	if (rack->r_ctl.rc_gp_lowrtt == 0xffffffff) {
4236 		/* We never made a us_rtt measurement? */
4237 		bytes = 0;
4238 		bytes_ps = 0;
4239 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4240 					   0, 0, 0, 10, __LINE__, NULL);
4241 		goto skip_measurement;
4242 	}
4243 	/*
4244 	 * Calculate the maximum possible b/w this connection
4245 	 * could have. We base our calculation on the lowest
4246 	 * rtt we have seen during the measurement and the
4247 	 * largest rwnd the client has given us in that time. This
4248 	 * forms a BDP that is the maximum that we could ever
4249 	 * get to the client. Anything larger is not valid.
4250 	 *
4251 	 * I originally had code here that rejected measurements
4252 	 * where the time was less than 1/2 the latest us_rtt.
4253 	 * But after thinking on that I realized its wrong since
4254 	 * say you had a 150Mbps or even 1Gbps link, and you
4255 	 * were a long way away.. example I am in Europe (100ms rtt)
4256 	 * talking to my 1Gbps link in S.C. Now measuring say 150,000
4257 	 * bytes my time would be 1.2ms, and yet my rtt would say
4258 	 * the measurement was invalid the time was < 50ms. The
4259 	 * same thing is true for 150Mb (8ms of time).
4260 	 *
4261 	 * A better way I realized is to look at what the maximum
4262 	 * the connection could possibly do. This is gated on
4263 	 * the lowest RTT we have seen and the highest rwnd.
4264 	 * We should in theory never exceed that, if we are
4265 	 * then something on the path is storing up packets
4266 	 * and then feeding them all at once to our endpoint
4267 	 * messing up our measurement.
4268 	 */
4269 	rack->r_ctl.last_max_bw = rack->r_ctl.rc_gp_high_rwnd;
4270 	rack->r_ctl.last_max_bw *= HPTS_USEC_IN_SEC;
4271 	rack->r_ctl.last_max_bw /= rack->r_ctl.rc_gp_lowrtt;
4272 	if (SEQ_LT(th_ack, tp->gput_seq)) {
4273 		/* No measurement can be made */
4274 		bytes = 0;
4275 		bytes_ps = 0;
4276 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4277 					   0, 0, 0, 10, __LINE__, NULL);
4278 		goto skip_measurement;
4279 	} else
4280 		bytes = (th_ack - tp->gput_seq);
4281 	bytes_ps = (uint64_t)bytes;
4282 	/*
4283 	 * Don't measure a b/w for pacing unless we have gotten at least
4284 	 * an initial windows worth of data in this measurement interval.
4285 	 *
4286 	 * Small numbers of bytes get badly influenced by delayed ack and
4287 	 * other artifacts. Note we take the initial window or our
4288 	 * defined minimum GP (defaulting to 10 which hopefully is the
4289 	 * IW).
4290 	 */
4291 	if (rack->rc_gp_filled == 0) {
4292 		/*
4293 		 * The initial estimate is special. We
4294 		 * have blasted out an IW worth of packets
4295 		 * without a real valid ack ts results. We
4296 		 * then setup the app_limited_needs_set flag,
4297 		 * this should get the first ack in (probably 2
4298 		 * MSS worth) to be recorded as the timestamp.
4299 		 * We thus allow a smaller number of bytes i.e.
4300 		 * IW - 2MSS.
4301 		 */
4302 		reqbytes -= (2 * segsiz);
4303 		/* Also lets fill previous for our first measurement to be neutral */
4304 		rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
4305 	}
4306 	if ((bytes_ps < reqbytes) || rack->app_limited_needs_set) {
4307 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4308 					   rack->r_ctl.rc_app_limited_cnt,
4309 					   0, 0, 10, __LINE__, NULL);
4310 		goto skip_measurement;
4311 	}
4312 	/*
4313 	 * We now need to calculate the Timely like status so
4314 	 * we can update (possibly) the b/w multipliers.
4315 	 */
4316 	new_rtt_diff = (int32_t)rack->r_ctl.rc_gp_srtt - (int32_t)rack->r_ctl.rc_prev_gp_srtt;
4317 	if (rack->rc_gp_filled == 0) {
4318 		/* No previous reading */
4319 		rack->r_ctl.rc_rtt_diff = new_rtt_diff;
4320 	} else {
4321 		if (rack->measure_saw_probe_rtt == 0) {
4322 			/*
4323 			 * We don't want a probertt to be counted
4324 			 * since it will be negative incorrectly. We
4325 			 * expect to be reducing the RTT when we
4326 			 * pace at a slower rate.
4327 			 */
4328 			rack->r_ctl.rc_rtt_diff -= (rack->r_ctl.rc_rtt_diff / 8);
4329 			rack->r_ctl.rc_rtt_diff += (new_rtt_diff / 8);
4330 		}
4331 	}
4332 	timely_says = rack_make_timely_judgement(rack,
4333 		rack->r_ctl.rc_gp_srtt,
4334 		rack->r_ctl.rc_rtt_diff,
4335 	        rack->r_ctl.rc_prev_gp_srtt
4336 		);
4337 	bytes_ps *= HPTS_USEC_IN_SEC;
4338 	bytes_ps /= utim;
4339 	if (bytes_ps > rack->r_ctl.last_max_bw) {
4340 		/*
4341 		 * Something is on path playing
4342 		 * since this b/w is not possible based
4343 		 * on our BDP (highest rwnd and lowest rtt
4344 		 * we saw in the measurement window).
4345 		 *
4346 		 * Another option here would be to
4347 		 * instead skip the measurement.
4348 		 */
4349 		rack_log_pacing_delay_calc(rack, bytes, reqbytes,
4350 					   bytes_ps, rack->r_ctl.last_max_bw, 0,
4351 					   11, __LINE__, NULL);
4352 		bytes_ps = rack->r_ctl.last_max_bw;
4353 	}
4354 	/* We store gp for b/w in bytes per second */
4355 	if (rack->rc_gp_filled == 0) {
4356 		/* Initial measurment */
4357 		if (bytes_ps) {
4358 			rack->r_ctl.gp_bw = bytes_ps;
4359 			rack->rc_gp_filled = 1;
4360 			rack->r_ctl.num_measurements = 1;
4361 			rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
4362 		} else {
4363 			rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4364 						   rack->r_ctl.rc_app_limited_cnt,
4365 						   0, 0, 10, __LINE__, NULL);
4366 		}
4367 		if (rack->rc_inp->inp_in_hpts &&
4368 		    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
4369 			/*
4370 			 * Ok we can't trust the pacer in this case
4371 			 * where we transition from un-paced to paced.
4372 			 * Or for that matter when the burst mitigation
4373 			 * was making a wild guess and got it wrong.
4374 			 * Stop the pacer and clear up all the aggregate
4375 			 * delays etc.
4376 			 */
4377 			tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
4378 			rack->r_ctl.rc_hpts_flags = 0;
4379 			rack->r_ctl.rc_last_output_to = 0;
4380 		}
4381 		did_add = 2;
4382 	} else if (rack->r_ctl.num_measurements < RACK_REQ_AVG) {
4383 		/* Still a small number run an average */
4384 		rack->r_ctl.gp_bw += bytes_ps;
4385 		addpart = rack->r_ctl.num_measurements;
4386 		rack->r_ctl.num_measurements++;
4387 		if (rack->r_ctl.num_measurements >= RACK_REQ_AVG) {
4388 			/* We have collected enought to move forward */
4389 			rack->r_ctl.gp_bw /= (uint64_t)rack->r_ctl.num_measurements;
4390 		}
4391 		did_add = 3;
4392 	} else {
4393 		/*
4394 		 * We want to take 1/wma of the goodput and add in to 7/8th
4395 		 * of the old value weighted by the srtt. So if your measurement
4396 		 * period is say 2 SRTT's long you would get 1/4 as the
4397 		 * value, if it was like 1/2 SRTT then you would get 1/16th.
4398 		 *
4399 		 * But we must be careful not to take too much i.e. if the
4400 		 * srtt is say 20ms and the measurement is taken over
4401 		 * 400ms our weight would be 400/20 i.e. 20. On the
4402 		 * other hand if we get a measurement over 1ms with a
4403 		 * 10ms rtt we only want to take a much smaller portion.
4404 		 */
4405 		if (rack->r_ctl.num_measurements < 0xff) {
4406 			rack->r_ctl.num_measurements++;
4407 		}
4408 		srtt = (uint64_t)tp->t_srtt;
4409 		if (srtt == 0) {
4410 			/*
4411 			 * Strange why did t_srtt go back to zero?
4412 			 */
4413 			if (rack->r_ctl.rc_rack_min_rtt)
4414 				srtt = rack->r_ctl.rc_rack_min_rtt;
4415 			else
4416 				srtt = HPTS_USEC_IN_MSEC;
4417 		}
4418 		/*
4419 		 * XXXrrs: Note for reviewers, in playing with
4420 		 * dynamic pacing I discovered this GP calculation
4421 		 * as done originally leads to some undesired results.
4422 		 * Basically you can get longer measurements contributing
4423 		 * too much to the WMA. Thus I changed it if you are doing
4424 		 * dynamic adjustments to only do the aportioned adjustment
4425 		 * if we have a very small (time wise) measurement. Longer
4426 		 * measurements just get there weight (defaulting to 1/8)
4427 		 * add to the WMA. We may want to think about changing
4428 		 * this to always do that for both sides i.e. dynamic
4429 		 * and non-dynamic... but considering lots of folks
4430 		 * were playing with this I did not want to change the
4431 		 * calculation per.se. without your thoughts.. Lawerence?
4432 		 * Peter??
4433 		 */
4434 		if (rack->rc_gp_dyn_mul == 0) {
4435 			subpart = rack->r_ctl.gp_bw * utim;
4436 			subpart /= (srtt * 8);
4437 			if (subpart < (rack->r_ctl.gp_bw / 2)) {
4438 				/*
4439 				 * The b/w update takes no more
4440 				 * away then 1/2 our running total
4441 				 * so factor it in.
4442 				 */
4443 				addpart = bytes_ps * utim;
4444 				addpart /= (srtt * 8);
4445 			} else {
4446 				/*
4447 				 * Don't allow a single measurement
4448 				 * to account for more than 1/2 of the
4449 				 * WMA. This could happen on a retransmission
4450 				 * where utim becomes huge compared to
4451 				 * srtt (multiple retransmissions when using
4452 				 * the sending rate which factors in all the
4453 				 * transmissions from the first one).
4454 				 */
4455 				subpart = rack->r_ctl.gp_bw / 2;
4456 				addpart = bytes_ps / 2;
4457 			}
4458 			resid_bw = rack->r_ctl.gp_bw - subpart;
4459 			rack->r_ctl.gp_bw = resid_bw + addpart;
4460 			did_add = 1;
4461 		} else {
4462 			if ((utim / srtt) <= 1) {
4463 				/*
4464 				 * The b/w update was over a small period
4465 				 * of time. The idea here is to prevent a small
4466 				 * measurement time period from counting
4467 				 * too much. So we scale it based on the
4468 				 * time so it attributes less than 1/rack_wma_divisor
4469 				 * of its measurement.
4470 				 */
4471 				subpart = rack->r_ctl.gp_bw * utim;
4472 				subpart /= (srtt * rack_wma_divisor);
4473 				addpart = bytes_ps * utim;
4474 				addpart /= (srtt * rack_wma_divisor);
4475 			} else {
4476 				/*
4477 				 * The scaled measurement was long
4478 				 * enough so lets just add in the
4479 				 * portion of the measurment i.e. 1/rack_wma_divisor
4480 				 */
4481 				subpart = rack->r_ctl.gp_bw / rack_wma_divisor;
4482 				addpart = bytes_ps / rack_wma_divisor;
4483 			}
4484 			if ((rack->measure_saw_probe_rtt == 0) ||
4485 		            (bytes_ps > rack->r_ctl.gp_bw)) {
4486 				/*
4487 				 * For probe-rtt we only add it in
4488 				 * if its larger, all others we just
4489 				 * add in.
4490 				 */
4491 				did_add = 1;
4492 				resid_bw = rack->r_ctl.gp_bw - subpart;
4493 				rack->r_ctl.gp_bw = resid_bw + addpart;
4494 			}
4495 		}
4496 	}
4497 	if ((rack->gp_ready == 0) &&
4498 	    (rack->r_ctl.num_measurements >= rack->r_ctl.req_measurements)) {
4499 		/* We have enough measurements now */
4500 		rack->gp_ready = 1;
4501 		rack_set_cc_pacing(rack);
4502 		if (rack->defer_options)
4503 			rack_apply_deferred_options(rack);
4504 	}
4505 	rack_log_pacing_delay_calc(rack, subpart, addpart, bytes_ps, stim,
4506 				   rack_get_bw(rack), 22, did_add, NULL);
4507 	/* We do not update any multipliers if we are in or have seen a probe-rtt */
4508 	if ((rack->measure_saw_probe_rtt == 0) && rack->rc_gp_rtt_set)
4509 		rack_update_multiplier(rack, timely_says, bytes_ps,
4510 				       rack->r_ctl.rc_gp_srtt,
4511 				       rack->r_ctl.rc_rtt_diff);
4512 	rack_log_pacing_delay_calc(rack, bytes, tim, bytes_ps, stim,
4513 				   rack_get_bw(rack), 3, line, NULL);
4514 	/* reset the gp srtt and setup the new prev */
4515 	rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
4516 	/* Record the lost count for the next measurement */
4517 	rack->r_ctl.rc_loss_at_start = rack->r_ctl.rc_loss_count;
4518 	/*
4519 	 * We restart our diffs based on the gpsrtt in the
4520 	 * measurement window.
4521 	 */
4522 	rack->rc_gp_rtt_set = 0;
4523 	rack->rc_gp_saw_rec = 0;
4524 	rack->rc_gp_saw_ca = 0;
4525 	rack->rc_gp_saw_ss = 0;
4526 	rack->rc_dragged_bottom = 0;
4527 skip_measurement:
4528 
4529 #ifdef STATS
4530 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_GPUT,
4531 				 gput);
4532 	/*
4533 	 * XXXLAS: This is a temporary hack, and should be
4534 	 * chained off VOI_TCP_GPUT when stats(9) grows an
4535 	 * API to deal with chained VOIs.
4536 	 */
4537 	if (tp->t_stats_gput_prev > 0)
4538 		stats_voi_update_abs_s32(tp->t_stats,
4539 					 VOI_TCP_GPUT_ND,
4540 					 ((gput - tp->t_stats_gput_prev) * 100) /
4541 					 tp->t_stats_gput_prev);
4542 #endif
4543 	tp->t_flags &= ~TF_GPUTINPROG;
4544 	tp->t_stats_gput_prev = gput;
4545 	/*
4546 	 * Now are we app limited now and there is space from where we
4547 	 * were to where we want to go?
4548 	 *
4549 	 * We don't do the other case i.e. non-applimited here since
4550 	 * the next send will trigger us picking up the missing data.
4551 	 */
4552 	if (rack->r_ctl.rc_first_appl &&
4553 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
4554 	    rack->r_ctl.rc_app_limited_cnt &&
4555 	    (SEQ_GT(rack->r_ctl.rc_first_appl->r_start, th_ack)) &&
4556 	    ((rack->r_ctl.rc_first_appl->r_start - th_ack) >
4557 	     max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
4558 		/*
4559 		 * Yep there is enough outstanding to make a measurement here.
4560 		 */
4561 		struct rack_sendmap *rsm, fe;
4562 
4563 		tp->t_flags |= TF_GPUTINPROG;
4564 		rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
4565 		rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
4566 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
4567 		rack->app_limited_needs_set = 0;
4568 		tp->gput_seq = th_ack;
4569 		if (rack->in_probe_rtt)
4570 			rack->measure_saw_probe_rtt = 1;
4571 		else if ((rack->measure_saw_probe_rtt) &&
4572 			 (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
4573 			rack->measure_saw_probe_rtt = 0;
4574 		if ((rack->r_ctl.rc_first_appl->r_start - th_ack) >= rack_get_measure_window(tp, rack)) {
4575 			/* There is a full window to gain info from */
4576 			tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
4577 		} else {
4578 			/* We can only measure up to the applimited point */
4579 			tp->gput_ack = tp->gput_seq + (rack->r_ctl.rc_first_appl->r_start - th_ack);
4580 		}
4581 		/*
4582 		 * Now we need to find the timestamp of the send at tp->gput_seq
4583 		 * for the send based measurement.
4584 		 */
4585 		fe.r_start = tp->gput_seq;
4586 		rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
4587 		if (rsm) {
4588 			/* Ok send-based limit is set */
4589 			if (SEQ_LT(rsm->r_start, tp->gput_seq)) {
4590 				/*
4591 				 * Move back to include the earlier part
4592 				 * so our ack time lines up right (this may
4593 				 * make an overlapping measurement but thats
4594 				 * ok).
4595 				 */
4596 				tp->gput_seq = rsm->r_start;
4597 			}
4598 			if (rsm->r_flags & RACK_ACKED)
4599 				tp->gput_ts = (uint32_t)rsm->r_ack_arrival;
4600 			else
4601 				rack->app_limited_needs_set = 1;
4602 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
4603 		} else {
4604 			/*
4605 			 * If we don't find the rsm due to some
4606 			 * send-limit set the current time, which
4607 			 * basically disables the send-limit.
4608 			 */
4609 			struct timeval tv;
4610 
4611 			microuptime(&tv);
4612 			rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
4613 		}
4614 		rack_log_pacing_delay_calc(rack,
4615 					   tp->gput_seq,
4616 					   tp->gput_ack,
4617 					   (uint64_t)rsm,
4618 					   tp->gput_ts,
4619 					   rack->r_ctl.rc_app_limited_cnt,
4620 					   9,
4621 					   __LINE__, NULL);
4622 	}
4623 }
4624 
4625 /*
4626  * CC wrapper hook functions
4627  */
4628 static void
4629 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack, uint32_t th_ack, uint16_t nsegs,
4630     uint16_t type, int32_t recovery)
4631 {
4632 	uint32_t prior_cwnd, acked;
4633 	struct tcp_log_buffer *lgb = NULL;
4634 	uint8_t labc_to_use;
4635 
4636 	INP_WLOCK_ASSERT(tp->t_inpcb);
4637 	tp->ccv->nsegs = nsegs;
4638 	acked = tp->ccv->bytes_this_ack = (th_ack - tp->snd_una);
4639 	if ((recovery) && (rack->r_ctl.rc_early_recovery_segs)) {
4640 		uint32_t max;
4641 
4642 		max = rack->r_ctl.rc_early_recovery_segs * ctf_fixed_maxseg(tp);
4643 		if (tp->ccv->bytes_this_ack > max) {
4644 			tp->ccv->bytes_this_ack = max;
4645 		}
4646 	}
4647 #ifdef STATS
4648 	stats_voi_update_abs_s32(tp->t_stats, VOI_TCP_CALCFRWINDIFF,
4649 	    ((int32_t)rack->r_ctl.cwnd_to_use) - tp->snd_wnd);
4650 #endif
4651 	if ((tp->t_flags & TF_GPUTINPROG) &&
4652 	    rack_enough_for_measurement(tp, rack, th_ack)) {
4653 		/* Measure the Goodput */
4654 		rack_do_goodput_measurement(tp, rack, th_ack, __LINE__);
4655 #ifdef NETFLIX_PEAKRATE
4656 		if ((type == CC_ACK) &&
4657 		    (tp->t_maxpeakrate)) {
4658 			/*
4659 			 * We update t_peakrate_thr. This gives us roughly
4660 			 * one update per round trip time. Note
4661 			 * it will only be used if pace_always is off i.e
4662 			 * we don't do this for paced flows.
4663 			 */
4664 			rack_update_peakrate_thr(tp);
4665 		}
4666 #endif
4667 	}
4668 	/* Which way our we limited, if not cwnd limited no advance in CA */
4669 	if (tp->snd_cwnd <= tp->snd_wnd)
4670 		tp->ccv->flags |= CCF_CWND_LIMITED;
4671 	else
4672 		tp->ccv->flags &= ~CCF_CWND_LIMITED;
4673 	if (tp->snd_cwnd > tp->snd_ssthresh) {
4674 		tp->t_bytes_acked += min(tp->ccv->bytes_this_ack,
4675 			 nsegs * V_tcp_abc_l_var * ctf_fixed_maxseg(tp));
4676 		/* For the setting of a window past use the actual scwnd we are using */
4677 		if (tp->t_bytes_acked >= rack->r_ctl.cwnd_to_use) {
4678 			tp->t_bytes_acked -= rack->r_ctl.cwnd_to_use;
4679 			tp->ccv->flags |= CCF_ABC_SENTAWND;
4680 		}
4681 	} else {
4682 		tp->ccv->flags &= ~CCF_ABC_SENTAWND;
4683 		tp->t_bytes_acked = 0;
4684 	}
4685 	prior_cwnd = tp->snd_cwnd;
4686 	if ((recovery == 0) || (rack_max_abc_post_recovery == 0) || rack->r_use_labc_for_rec ||
4687 	    (rack_client_low_buf && (rack->client_bufferlvl < rack_client_low_buf)))
4688 		labc_to_use = rack->rc_labc;
4689 	else
4690 		labc_to_use = rack_max_abc_post_recovery;
4691 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
4692 		union tcp_log_stackspecific log;
4693 		struct timeval tv;
4694 
4695 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
4696 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
4697 		log.u_bbr.flex1 = th_ack;
4698 		log.u_bbr.flex2 = tp->ccv->flags;
4699 		log.u_bbr.flex3 = tp->ccv->bytes_this_ack;
4700 		log.u_bbr.flex4 = tp->ccv->nsegs;
4701 		log.u_bbr.flex5 = labc_to_use;
4702 		log.u_bbr.flex6 = prior_cwnd;
4703 		log.u_bbr.flex7 = V_tcp_do_newsack;
4704 		log.u_bbr.flex8 = 1;
4705 		lgb = tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
4706 				     0, &log, false, NULL, NULL, 0, &tv);
4707 	}
4708 	if (CC_ALGO(tp)->ack_received != NULL) {
4709 		/* XXXLAS: Find a way to live without this */
4710 		tp->ccv->curack = th_ack;
4711 		tp->ccv->labc = labc_to_use;
4712 		tp->ccv->flags |= CCF_USE_LOCAL_ABC;
4713 		CC_ALGO(tp)->ack_received(tp->ccv, type);
4714 	}
4715 	if (lgb) {
4716 		lgb->tlb_stackinfo.u_bbr.flex6 = tp->snd_cwnd;
4717 	}
4718 	if (rack->r_must_retran) {
4719 		if (SEQ_GEQ(th_ack, rack->r_ctl.rc_snd_max_at_rto)) {
4720 			/*
4721 			 * We now are beyond the rxt point so lets disable
4722 			 * the flag.
4723 			 */
4724 			rack->r_ctl.rc_out_at_rto = 0;
4725 			rack->r_must_retran = 0;
4726 		} else if ((prior_cwnd + ctf_fixed_maxseg(tp)) <= tp->snd_cwnd) {
4727 			/*
4728 			 * Only decrement the rc_out_at_rto if the cwnd advances
4729 			 * at least a whole segment. Otherwise next time the peer
4730 			 * acks, we won't be able to send this generaly happens
4731 			 * when we are in Congestion Avoidance.
4732 			 */
4733 			if (acked <= rack->r_ctl.rc_out_at_rto){
4734 				rack->r_ctl.rc_out_at_rto -= acked;
4735 			} else {
4736 				rack->r_ctl.rc_out_at_rto = 0;
4737 			}
4738 		}
4739 	}
4740 #ifdef STATS
4741 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_LCWIN, rack->r_ctl.cwnd_to_use);
4742 #endif
4743 	if (rack->r_ctl.rc_rack_largest_cwnd < rack->r_ctl.cwnd_to_use) {
4744 		rack->r_ctl.rc_rack_largest_cwnd = rack->r_ctl.cwnd_to_use;
4745 	}
4746 #ifdef NETFLIX_PEAKRATE
4747 	/* we enforce max peak rate if it is set and we are not pacing */
4748 	if ((rack->rc_always_pace == 0) &&
4749 	    tp->t_peakrate_thr &&
4750 	    (tp->snd_cwnd > tp->t_peakrate_thr)) {
4751 		tp->snd_cwnd = tp->t_peakrate_thr;
4752 	}
4753 #endif
4754 }
4755 
4756 static void
4757 tcp_rack_partialack(struct tcpcb *tp)
4758 {
4759 	struct tcp_rack *rack;
4760 
4761 	rack = (struct tcp_rack *)tp->t_fb_ptr;
4762 	INP_WLOCK_ASSERT(tp->t_inpcb);
4763 	/*
4764 	 * If we are doing PRR and have enough
4765 	 * room to send <or> we are pacing and prr
4766 	 * is disabled we will want to see if we
4767 	 * can send data (by setting r_wanted_output to
4768 	 * true).
4769 	 */
4770 	if ((rack->r_ctl.rc_prr_sndcnt > 0) ||
4771 	    rack->rack_no_prr)
4772 		rack->r_wanted_output = 1;
4773 }
4774 
4775 static void
4776 rack_post_recovery(struct tcpcb *tp, uint32_t th_ack)
4777 {
4778 	struct tcp_rack *rack;
4779 	uint32_t orig_cwnd;
4780 
4781 	orig_cwnd = tp->snd_cwnd;
4782 	INP_WLOCK_ASSERT(tp->t_inpcb);
4783 	rack = (struct tcp_rack *)tp->t_fb_ptr;
4784 	/* only alert CC if we alerted when we entered */
4785 	if (CC_ALGO(tp)->post_recovery != NULL) {
4786 		tp->ccv->curack = th_ack;
4787 		CC_ALGO(tp)->post_recovery(tp->ccv);
4788 		if (tp->snd_cwnd < tp->snd_ssthresh) {
4789 			/*
4790 			 * Rack has burst control and pacing
4791 			 * so lets not set this any lower than
4792 			 * snd_ssthresh per RFC-6582 (option 2).
4793 			 */
4794 			tp->snd_cwnd = tp->snd_ssthresh;
4795 		}
4796 	}
4797 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
4798 		union tcp_log_stackspecific log;
4799 		struct timeval tv;
4800 
4801 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
4802 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
4803 		log.u_bbr.flex1 = th_ack;
4804 		log.u_bbr.flex2 = tp->ccv->flags;
4805 		log.u_bbr.flex3 = tp->ccv->bytes_this_ack;
4806 		log.u_bbr.flex4 = tp->ccv->nsegs;
4807 		log.u_bbr.flex5 = V_tcp_abc_l_var;
4808 		log.u_bbr.flex6 = orig_cwnd;
4809 		log.u_bbr.flex7 = V_tcp_do_newsack;
4810 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
4811 		log.u_bbr.flex8 = 2;
4812 		tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
4813 			       0, &log, false, NULL, NULL, 0, &tv);
4814 	}
4815 	if ((rack->rack_no_prr == 0) &&
4816 	    (rack->no_prr_addback == 0) &&
4817 	    (rack->r_ctl.rc_prr_sndcnt > 0)) {
4818 		/*
4819 		 * Suck the next prr cnt back into cwnd, but
4820 		 * only do that if we are not application limited.
4821 		 */
4822 		if (ctf_outstanding(tp) <= sbavail(&(tp->t_inpcb->inp_socket->so_snd))) {
4823 			/*
4824 			 * We are allowed to add back to the cwnd the amount we did
4825 			 * not get out if:
4826 			 * a) no_prr_addback is off.
4827 			 * b) we are not app limited
4828 			 * c) we are doing prr
4829 			 * <and>
4830 			 * d) it is bounded by rack_prr_addbackmax (if addback is 0, then none).
4831 			 */
4832 			tp->snd_cwnd += min((ctf_fixed_maxseg(tp) * rack_prr_addbackmax),
4833 					    rack->r_ctl.rc_prr_sndcnt);
4834 		}
4835 		rack->r_ctl.rc_prr_sndcnt = 0;
4836 		rack_log_to_prr(rack, 1, 0);
4837 	}
4838 	rack_log_to_prr(rack, 14, orig_cwnd);
4839 	tp->snd_recover = tp->snd_una;
4840 	EXIT_RECOVERY(tp->t_flags);
4841 }
4842 
4843 static void
4844 rack_cong_signal(struct tcpcb *tp, uint32_t type, uint32_t ack)
4845 {
4846 	struct tcp_rack *rack;
4847 	uint32_t ssthresh_enter, cwnd_enter, in_rec_at_entry, orig_cwnd;
4848 
4849 	INP_WLOCK_ASSERT(tp->t_inpcb);
4850 #ifdef STATS
4851 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_CSIG, type);
4852 #endif
4853 	if (IN_RECOVERY(tp->t_flags) == 0) {
4854 		in_rec_at_entry = 0;
4855 		ssthresh_enter = tp->snd_ssthresh;
4856 		cwnd_enter = tp->snd_cwnd;
4857 	} else
4858 		in_rec_at_entry = 1;
4859 	rack = (struct tcp_rack *)tp->t_fb_ptr;
4860 	switch (type) {
4861 	case CC_NDUPACK:
4862 		tp->t_flags &= ~TF_WASFRECOVERY;
4863 		tp->t_flags &= ~TF_WASCRECOVERY;
4864 		if (!IN_FASTRECOVERY(tp->t_flags)) {
4865 			rack->r_ctl.rc_prr_delivered = 0;
4866 			rack->r_ctl.rc_prr_out = 0;
4867 			if (rack->rack_no_prr == 0) {
4868 				rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
4869 				rack_log_to_prr(rack, 2, in_rec_at_entry);
4870 			}
4871 			rack->r_ctl.rc_prr_recovery_fs = tp->snd_max - tp->snd_una;
4872 			tp->snd_recover = tp->snd_max;
4873 			if (tp->t_flags2 & TF2_ECN_PERMIT)
4874 				tp->t_flags2 |= TF2_ECN_SND_CWR;
4875 		}
4876 		break;
4877 	case CC_ECN:
4878 		if (!IN_CONGRECOVERY(tp->t_flags) ||
4879 		    /*
4880 		     * Allow ECN reaction on ACK to CWR, if
4881 		     * that data segment was also CE marked.
4882 		     */
4883 		    SEQ_GEQ(ack, tp->snd_recover)) {
4884 			EXIT_CONGRECOVERY(tp->t_flags);
4885 			KMOD_TCPSTAT_INC(tcps_ecn_rcwnd);
4886 			tp->snd_recover = tp->snd_max + 1;
4887 			if (tp->t_flags2 & TF2_ECN_PERMIT)
4888 				tp->t_flags2 |= TF2_ECN_SND_CWR;
4889 		}
4890 		break;
4891 	case CC_RTO:
4892 		tp->t_dupacks = 0;
4893 		tp->t_bytes_acked = 0;
4894 		EXIT_RECOVERY(tp->t_flags);
4895 		tp->snd_ssthresh = max(2, min(tp->snd_wnd, rack->r_ctl.cwnd_to_use) / 2 /
4896 		    ctf_fixed_maxseg(tp)) * ctf_fixed_maxseg(tp);
4897 		orig_cwnd = tp->snd_cwnd;
4898 		tp->snd_cwnd = ctf_fixed_maxseg(tp);
4899 		rack_log_to_prr(rack, 16, orig_cwnd);
4900 		if (tp->t_flags2 & TF2_ECN_PERMIT)
4901 			tp->t_flags2 |= TF2_ECN_SND_CWR;
4902 		break;
4903 	case CC_RTO_ERR:
4904 		KMOD_TCPSTAT_INC(tcps_sndrexmitbad);
4905 		/* RTO was unnecessary, so reset everything. */
4906 		tp->snd_cwnd = tp->snd_cwnd_prev;
4907 		tp->snd_ssthresh = tp->snd_ssthresh_prev;
4908 		tp->snd_recover = tp->snd_recover_prev;
4909 		if (tp->t_flags & TF_WASFRECOVERY) {
4910 			ENTER_FASTRECOVERY(tp->t_flags);
4911 			tp->t_flags &= ~TF_WASFRECOVERY;
4912 		}
4913 		if (tp->t_flags & TF_WASCRECOVERY) {
4914 			ENTER_CONGRECOVERY(tp->t_flags);
4915 			tp->t_flags &= ~TF_WASCRECOVERY;
4916 		}
4917 		tp->snd_nxt = tp->snd_max;
4918 		tp->t_badrxtwin = 0;
4919 		break;
4920 	}
4921 	if ((CC_ALGO(tp)->cong_signal != NULL)  &&
4922 	    (type != CC_RTO)){
4923 		tp->ccv->curack = ack;
4924 		CC_ALGO(tp)->cong_signal(tp->ccv, type);
4925 	}
4926 	if ((in_rec_at_entry == 0) && IN_RECOVERY(tp->t_flags)) {
4927 		rack_log_to_prr(rack, 15, cwnd_enter);
4928 		rack->r_ctl.dsack_byte_cnt = 0;
4929 		rack->r_ctl.retran_during_recovery = 0;
4930 		rack->r_ctl.rc_cwnd_at_erec = cwnd_enter;
4931 		rack->r_ctl.rc_ssthresh_at_erec = ssthresh_enter;
4932 		rack->r_ent_rec_ns = 1;
4933 	}
4934 }
4935 
4936 static inline void
4937 rack_cc_after_idle(struct tcp_rack *rack, struct tcpcb *tp)
4938 {
4939 	uint32_t i_cwnd;
4940 
4941 	INP_WLOCK_ASSERT(tp->t_inpcb);
4942 
4943 #ifdef NETFLIX_STATS
4944 	KMOD_TCPSTAT_INC(tcps_idle_restarts);
4945 	if (tp->t_state == TCPS_ESTABLISHED)
4946 		KMOD_TCPSTAT_INC(tcps_idle_estrestarts);
4947 #endif
4948 	if (CC_ALGO(tp)->after_idle != NULL)
4949 		CC_ALGO(tp)->after_idle(tp->ccv);
4950 
4951 	if (tp->snd_cwnd == 1)
4952 		i_cwnd = tp->t_maxseg;		/* SYN(-ACK) lost */
4953 	else
4954 		i_cwnd = rc_init_window(rack);
4955 
4956 	/*
4957 	 * Being idle is no differnt than the initial window. If the cc
4958 	 * clamps it down below the initial window raise it to the initial
4959 	 * window.
4960 	 */
4961 	if (tp->snd_cwnd < i_cwnd) {
4962 		tp->snd_cwnd = i_cwnd;
4963 	}
4964 }
4965 
4966 /*
4967  * Indicate whether this ack should be delayed.  We can delay the ack if
4968  * following conditions are met:
4969  *	- There is no delayed ack timer in progress.
4970  *	- Our last ack wasn't a 0-sized window. We never want to delay
4971  *	  the ack that opens up a 0-sized window.
4972  *	- LRO wasn't used for this segment. We make sure by checking that the
4973  *	  segment size is not larger than the MSS.
4974  *	- Delayed acks are enabled or this is a half-synchronized T/TCP
4975  *	  connection.
4976  */
4977 #define DELAY_ACK(tp, tlen)			 \
4978 	(((tp->t_flags & TF_RXWIN0SENT) == 0) && \
4979 	((tp->t_flags & TF_DELACK) == 0) &&	 \
4980 	(tlen <= tp->t_maxseg) &&		 \
4981 	(tp->t_delayed_ack || (tp->t_flags & TF_NEEDSYN)))
4982 
4983 static struct rack_sendmap *
4984 rack_find_lowest_rsm(struct tcp_rack *rack)
4985 {
4986 	struct rack_sendmap *rsm;
4987 
4988 	/*
4989 	 * Walk the time-order transmitted list looking for an rsm that is
4990 	 * not acked. This will be the one that was sent the longest time
4991 	 * ago that is still outstanding.
4992 	 */
4993 	TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
4994 		if (rsm->r_flags & RACK_ACKED) {
4995 			continue;
4996 		}
4997 		goto finish;
4998 	}
4999 finish:
5000 	return (rsm);
5001 }
5002 
5003 static struct rack_sendmap *
5004 rack_find_high_nonack(struct tcp_rack *rack, struct rack_sendmap *rsm)
5005 {
5006 	struct rack_sendmap *prsm;
5007 
5008 	/*
5009 	 * Walk the sequence order list backward until we hit and arrive at
5010 	 * the highest seq not acked. In theory when this is called it
5011 	 * should be the last segment (which it was not).
5012 	 */
5013 	counter_u64_add(rack_find_high, 1);
5014 	prsm = rsm;
5015 	RB_FOREACH_REVERSE_FROM(prsm, rack_rb_tree_head, rsm) {
5016 		if (prsm->r_flags & (RACK_ACKED | RACK_HAS_FIN)) {
5017 			continue;
5018 		}
5019 		return (prsm);
5020 	}
5021 	return (NULL);
5022 }
5023 
5024 static uint32_t
5025 rack_calc_thresh_rack(struct tcp_rack *rack, uint32_t srtt, uint32_t cts)
5026 {
5027 	int32_t lro;
5028 	uint32_t thresh;
5029 
5030 	/*
5031 	 * lro is the flag we use to determine if we have seen reordering.
5032 	 * If it gets set we have seen reordering. The reorder logic either
5033 	 * works in one of two ways:
5034 	 *
5035 	 * If reorder-fade is configured, then we track the last time we saw
5036 	 * re-ordering occur. If we reach the point where enough time as
5037 	 * passed we no longer consider reordering has occuring.
5038 	 *
5039 	 * Or if reorder-face is 0, then once we see reordering we consider
5040 	 * the connection to alway be subject to reordering and just set lro
5041 	 * to 1.
5042 	 *
5043 	 * In the end if lro is non-zero we add the extra time for
5044 	 * reordering in.
5045 	 */
5046 	if (srtt == 0)
5047 		srtt = 1;
5048 	if (rack->r_ctl.rc_reorder_ts) {
5049 		if (rack->r_ctl.rc_reorder_fade) {
5050 			if (SEQ_GEQ(cts, rack->r_ctl.rc_reorder_ts)) {
5051 				lro = cts - rack->r_ctl.rc_reorder_ts;
5052 				if (lro == 0) {
5053 					/*
5054 					 * No time as passed since the last
5055 					 * reorder, mark it as reordering.
5056 					 */
5057 					lro = 1;
5058 				}
5059 			} else {
5060 				/* Negative time? */
5061 				lro = 0;
5062 			}
5063 			if (lro > rack->r_ctl.rc_reorder_fade) {
5064 				/* Turn off reordering seen too */
5065 				rack->r_ctl.rc_reorder_ts = 0;
5066 				lro = 0;
5067 			}
5068 		} else {
5069 			/* Reodering does not fade */
5070 			lro = 1;
5071 		}
5072 	} else {
5073 		lro = 0;
5074 	}
5075 	thresh = srtt + rack->r_ctl.rc_pkt_delay;
5076 	if (lro) {
5077 		/* It must be set, if not you get 1/4 rtt */
5078 		if (rack->r_ctl.rc_reorder_shift)
5079 			thresh += (srtt >> rack->r_ctl.rc_reorder_shift);
5080 		else
5081 			thresh += (srtt >> 2);
5082 	} else {
5083 		thresh += 1;
5084 	}
5085 	/* We don't let the rack timeout be above a RTO */
5086 	if (thresh > rack->rc_tp->t_rxtcur) {
5087 		thresh = rack->rc_tp->t_rxtcur;
5088 	}
5089 	/* And we don't want it above the RTO max either */
5090 	if (thresh > rack_rto_max) {
5091 		thresh = rack_rto_max;
5092 	}
5093 	return (thresh);
5094 }
5095 
5096 static uint32_t
5097 rack_calc_thresh_tlp(struct tcpcb *tp, struct tcp_rack *rack,
5098 		     struct rack_sendmap *rsm, uint32_t srtt)
5099 {
5100 	struct rack_sendmap *prsm;
5101 	uint32_t thresh, len;
5102 	int segsiz;
5103 
5104 	if (srtt == 0)
5105 		srtt = 1;
5106 	if (rack->r_ctl.rc_tlp_threshold)
5107 		thresh = srtt + (srtt / rack->r_ctl.rc_tlp_threshold);
5108 	else
5109 		thresh = (srtt * 2);
5110 
5111 	/* Get the previous sent packet, if any */
5112 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
5113 	counter_u64_add(rack_enter_tlp_calc, 1);
5114 	len = rsm->r_end - rsm->r_start;
5115 	if (rack->rack_tlp_threshold_use == TLP_USE_ID) {
5116 		/* Exactly like the ID */
5117 		if (((tp->snd_max - tp->snd_una) - rack->r_ctl.rc_sacked + rack->r_ctl.rc_holes_rxt) <= segsiz) {
5118 			uint32_t alt_thresh;
5119 			/*
5120 			 * Compensate for delayed-ack with the d-ack time.
5121 			 */
5122 			counter_u64_add(rack_used_tlpmethod, 1);
5123 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5124 			if (alt_thresh > thresh)
5125 				thresh = alt_thresh;
5126 		}
5127 	} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_ONE) {
5128 		/* 2.1 behavior */
5129 		prsm = TAILQ_PREV(rsm, rack_head, r_tnext);
5130 		if (prsm && (len <= segsiz)) {
5131 			/*
5132 			 * Two packets outstanding, thresh should be (2*srtt) +
5133 			 * possible inter-packet delay (if any).
5134 			 */
5135 			uint32_t inter_gap = 0;
5136 			int idx, nidx;
5137 
5138 			counter_u64_add(rack_used_tlpmethod, 1);
5139 			idx = rsm->r_rtr_cnt - 1;
5140 			nidx = prsm->r_rtr_cnt - 1;
5141 			if (rsm->r_tim_lastsent[nidx] >= prsm->r_tim_lastsent[idx]) {
5142 				/* Yes it was sent later (or at the same time) */
5143 				inter_gap = rsm->r_tim_lastsent[idx] - prsm->r_tim_lastsent[nidx];
5144 			}
5145 			thresh += inter_gap;
5146 		} else if (len <= segsiz) {
5147 			/*
5148 			 * Possibly compensate for delayed-ack.
5149 			 */
5150 			uint32_t alt_thresh;
5151 
5152 			counter_u64_add(rack_used_tlpmethod2, 1);
5153 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5154 			if (alt_thresh > thresh)
5155 				thresh = alt_thresh;
5156 		}
5157 	} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_TWO) {
5158 		/* 2.2 behavior */
5159 		if (len <= segsiz) {
5160 			uint32_t alt_thresh;
5161 			/*
5162 			 * Compensate for delayed-ack with the d-ack time.
5163 			 */
5164 			counter_u64_add(rack_used_tlpmethod, 1);
5165 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5166 			if (alt_thresh > thresh)
5167 				thresh = alt_thresh;
5168 		}
5169 	}
5170 	/* Not above an RTO */
5171 	if (thresh > tp->t_rxtcur) {
5172 		thresh = tp->t_rxtcur;
5173 	}
5174 	/* Not above a RTO max */
5175 	if (thresh > rack_rto_max) {
5176 		thresh = rack_rto_max;
5177 	}
5178 	/* Apply user supplied min TLP */
5179 	if (thresh < rack_tlp_min) {
5180 		thresh = rack_tlp_min;
5181 	}
5182 	return (thresh);
5183 }
5184 
5185 static uint32_t
5186 rack_grab_rtt(struct tcpcb *tp, struct tcp_rack *rack)
5187 {
5188 	/*
5189 	 * We want the rack_rtt which is the
5190 	 * last rtt we measured. However if that
5191 	 * does not exist we fallback to the srtt (which
5192 	 * we probably will never do) and then as a last
5193 	 * resort we use RACK_INITIAL_RTO if no srtt is
5194 	 * yet set.
5195 	 */
5196 	if (rack->rc_rack_rtt)
5197 		return (rack->rc_rack_rtt);
5198 	else if (tp->t_srtt == 0)
5199 		return (RACK_INITIAL_RTO);
5200 	return (tp->t_srtt);
5201 }
5202 
5203 static struct rack_sendmap *
5204 rack_check_recovery_mode(struct tcpcb *tp, uint32_t tsused)
5205 {
5206 	/*
5207 	 * Check to see that we don't need to fall into recovery. We will
5208 	 * need to do so if our oldest transmit is past the time we should
5209 	 * have had an ack.
5210 	 */
5211 	struct tcp_rack *rack;
5212 	struct rack_sendmap *rsm;
5213 	int32_t idx;
5214 	uint32_t srtt, thresh;
5215 
5216 	rack = (struct tcp_rack *)tp->t_fb_ptr;
5217 	if (RB_EMPTY(&rack->r_ctl.rc_mtree)) {
5218 		return (NULL);
5219 	}
5220 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
5221 	if (rsm == NULL)
5222 		return (NULL);
5223 
5224 	if (rsm->r_flags & RACK_ACKED) {
5225 		rsm = rack_find_lowest_rsm(rack);
5226 		if (rsm == NULL)
5227 			return (NULL);
5228 	}
5229 	idx = rsm->r_rtr_cnt - 1;
5230 	srtt = rack_grab_rtt(tp, rack);
5231 	thresh = rack_calc_thresh_rack(rack, srtt, tsused);
5232 	if (TSTMP_LT(tsused, ((uint32_t)rsm->r_tim_lastsent[idx]))) {
5233 		return (NULL);
5234 	}
5235 	if ((tsused - ((uint32_t)rsm->r_tim_lastsent[idx])) < thresh) {
5236 		return (NULL);
5237 	}
5238 	/* Ok if we reach here we are over-due and this guy can be sent */
5239 	if (IN_RECOVERY(tp->t_flags) == 0) {
5240 		/*
5241 		 * For the one that enters us into recovery record undo
5242 		 * info.
5243 		 */
5244 		rack->r_ctl.rc_rsm_start = rsm->r_start;
5245 		rack->r_ctl.rc_cwnd_at = tp->snd_cwnd;
5246 		rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh;
5247 	}
5248 	rack_cong_signal(tp, CC_NDUPACK, tp->snd_una);
5249 	return (rsm);
5250 }
5251 
5252 static uint32_t
5253 rack_get_persists_timer_val(struct tcpcb *tp, struct tcp_rack *rack)
5254 {
5255 	int32_t t;
5256 	int32_t tt;
5257 	uint32_t ret_val;
5258 
5259 	t = (tp->t_srtt + (tp->t_rttvar << 2));
5260 	RACK_TCPT_RANGESET(tt, t * tcp_backoff[tp->t_rxtshift],
5261  	    rack_persist_min, rack_persist_max, rack->r_ctl.timer_slop);
5262 	if (tp->t_rxtshift < TCP_MAXRXTSHIFT)
5263 		tp->t_rxtshift++;
5264 	rack->r_ctl.rc_hpts_flags |= PACE_TMR_PERSIT;
5265 	ret_val = (uint32_t)tt;
5266 	return (ret_val);
5267 }
5268 
5269 static uint32_t
5270 rack_timer_start(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int sup_rack)
5271 {
5272 	/*
5273 	 * Start the FR timer, we do this based on getting the first one in
5274 	 * the rc_tmap. Note that if its NULL we must stop the timer. in all
5275 	 * events we need to stop the running timer (if its running) before
5276 	 * starting the new one.
5277 	 */
5278 	uint32_t thresh, exp, to, srtt, time_since_sent, tstmp_touse;
5279 	uint32_t srtt_cur;
5280 	int32_t idx;
5281 	int32_t is_tlp_timer = 0;
5282 	struct rack_sendmap *rsm;
5283 
5284 	if (rack->t_timers_stopped) {
5285 		/* All timers have been stopped none are to run */
5286 		return (0);
5287 	}
5288 	if (rack->rc_in_persist) {
5289 		/* We can't start any timer in persists */
5290 		return (rack_get_persists_timer_val(tp, rack));
5291 	}
5292 	rack->rc_on_min_to = 0;
5293 	if ((tp->t_state < TCPS_ESTABLISHED) ||
5294 	    ((tp->t_flags & TF_SACK_PERMIT) == 0)) {
5295 		goto activate_rxt;
5296 	}
5297 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
5298 	if ((rsm == NULL) || sup_rack) {
5299 		/* Nothing on the send map or no rack */
5300 activate_rxt:
5301 		time_since_sent = 0;
5302 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
5303 		if (rsm) {
5304 			/*
5305 			 * Should we discount the RTX timer any?
5306 			 *
5307 			 * We want to discount it the smallest amount.
5308 			 * If a timer (Rack/TLP or RXT) has gone off more
5309 			 * recently thats the discount we want to use (now - timer time).
5310 			 * If the retransmit of the oldest packet was more recent then
5311 			 * we want to use that (now - oldest-packet-last_transmit_time).
5312 			 *
5313 			 */
5314 			idx = rsm->r_rtr_cnt - 1;
5315 			if (TSTMP_GEQ(rack->r_ctl.rc_tlp_rxt_last_time, ((uint32_t)rsm->r_tim_lastsent[idx])))
5316 				tstmp_touse = (uint32_t)rack->r_ctl.rc_tlp_rxt_last_time;
5317 			else
5318 				tstmp_touse = (uint32_t)rsm->r_tim_lastsent[idx];
5319 			if (TSTMP_GT(cts, tstmp_touse))
5320 			    time_since_sent = cts - tstmp_touse;
5321 		}
5322 		if (SEQ_LT(tp->snd_una, tp->snd_max) || sbavail(&(tp->t_inpcb->inp_socket->so_snd))) {
5323 			rack->r_ctl.rc_hpts_flags |= PACE_TMR_RXT;
5324 			to = tp->t_rxtcur;
5325 			if (to > time_since_sent)
5326 				to -= time_since_sent;
5327 			else
5328 				to = rack->r_ctl.rc_min_to;
5329 			if (to == 0)
5330 				to = 1;
5331 			/* Special case for KEEPINIT */
5332 			if ((TCPS_HAVEESTABLISHED(tp->t_state) == 0) &&
5333 			    (TP_KEEPINIT(tp) != 0) &&
5334 			    rsm) {
5335 				/*
5336 				 * We have to put a ceiling on the rxt timer
5337 				 * of the keep-init timeout.
5338 				 */
5339 				uint32_t max_time, red;
5340 
5341 				max_time = TICKS_2_USEC(TP_KEEPINIT(tp));
5342 				if (TSTMP_GT(cts, (uint32_t)rsm->r_tim_lastsent[0])) {
5343 					red = (cts - (uint32_t)rsm->r_tim_lastsent[0]);
5344 					if (red < max_time)
5345 						max_time -= red;
5346 					else
5347 						max_time = 1;
5348 				}
5349 				/* Reduce timeout to the keep value if needed */
5350 				if (max_time < to)
5351 					to = max_time;
5352 			}
5353 			return (to);
5354 		}
5355 		return (0);
5356 	}
5357 	if (rsm->r_flags & RACK_ACKED) {
5358 		rsm = rack_find_lowest_rsm(rack);
5359 		if (rsm == NULL) {
5360 			/* No lowest? */
5361 			goto activate_rxt;
5362 		}
5363 	}
5364 	if (rack->sack_attack_disable) {
5365 		/*
5366 		 * We don't want to do
5367 		 * any TLP's if you are an attacker.
5368 		 * Though if you are doing what
5369 		 * is expected you may still have
5370 		 * SACK-PASSED marks.
5371 		 */
5372 		goto activate_rxt;
5373 	}
5374 	/* Convert from ms to usecs */
5375 	if ((rsm->r_flags & RACK_SACK_PASSED) || (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
5376 		if ((tp->t_flags & TF_SENTFIN) &&
5377 		    ((tp->snd_max - tp->snd_una) == 1) &&
5378 		    (rsm->r_flags & RACK_HAS_FIN)) {
5379 			/*
5380 			 * We don't start a rack timer if all we have is a
5381 			 * FIN outstanding.
5382 			 */
5383 			goto activate_rxt;
5384 		}
5385 		if ((rack->use_rack_rr == 0) &&
5386 		    (IN_FASTRECOVERY(tp->t_flags)) &&
5387 		    (rack->rack_no_prr == 0) &&
5388 		     (rack->r_ctl.rc_prr_sndcnt  < ctf_fixed_maxseg(tp))) {
5389 			/*
5390 			 * We are not cheating, in recovery  and
5391 			 * not enough ack's to yet get our next
5392 			 * retransmission out.
5393 			 *
5394 			 * Note that classified attackers do not
5395 			 * get to use the rack-cheat.
5396 			 */
5397 			goto activate_tlp;
5398 		}
5399 		srtt = rack_grab_rtt(tp, rack);
5400 		thresh = rack_calc_thresh_rack(rack, srtt, cts);
5401 		idx = rsm->r_rtr_cnt - 1;
5402 		exp = ((uint32_t)rsm->r_tim_lastsent[idx]) + thresh;
5403 		if (SEQ_GEQ(exp, cts)) {
5404 			to = exp - cts;
5405 			if (to < rack->r_ctl.rc_min_to) {
5406 				to = rack->r_ctl.rc_min_to;
5407 				if (rack->r_rr_config == 3)
5408 					rack->rc_on_min_to = 1;
5409 			}
5410 		} else {
5411 			to = rack->r_ctl.rc_min_to;
5412 			if (rack->r_rr_config == 3)
5413 				rack->rc_on_min_to = 1;
5414 		}
5415 	} else {
5416 		/* Ok we need to do a TLP not RACK */
5417 activate_tlp:
5418 		if ((rack->rc_tlp_in_progress != 0) &&
5419 		    (rack->r_ctl.rc_tlp_cnt_out >= rack_tlp_limit)) {
5420 			/*
5421 			 * The previous send was a TLP and we have sent
5422 			 * N TLP's without sending new data.
5423 			 */
5424 			goto activate_rxt;
5425 		}
5426 		rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
5427 		if (rsm == NULL) {
5428 			/* We found no rsm to TLP with. */
5429 			goto activate_rxt;
5430 		}
5431 		if (rsm->r_flags & RACK_HAS_FIN) {
5432 			/* If its a FIN we dont do TLP */
5433 			rsm = NULL;
5434 			goto activate_rxt;
5435 		}
5436 		idx = rsm->r_rtr_cnt - 1;
5437 		time_since_sent = 0;
5438 		if (TSTMP_GEQ(((uint32_t)rsm->r_tim_lastsent[idx]), rack->r_ctl.rc_tlp_rxt_last_time))
5439 			tstmp_touse = (uint32_t)rsm->r_tim_lastsent[idx];
5440 		else
5441 			tstmp_touse = (uint32_t)rack->r_ctl.rc_tlp_rxt_last_time;
5442 		if (TSTMP_GT(cts, tstmp_touse))
5443 		    time_since_sent = cts - tstmp_touse;
5444 		is_tlp_timer = 1;
5445 		if (tp->t_srtt) {
5446 			if ((rack->rc_srtt_measure_made == 0) &&
5447 			    (tp->t_srtt == 1)) {
5448 				/*
5449 				 * If another stack as run and set srtt to 1,
5450 				 * then the srtt was 0, so lets use the initial.
5451 				 */
5452 				srtt = RACK_INITIAL_RTO;
5453 			} else {
5454 				srtt_cur = tp->t_srtt;
5455 				srtt = srtt_cur;
5456 			}
5457 		} else
5458 			srtt = RACK_INITIAL_RTO;
5459 		/*
5460 		 * If the SRTT is not keeping up and the
5461 		 * rack RTT has spiked we want to use
5462 		 * the last RTT not the smoothed one.
5463 		 */
5464 		if (rack_tlp_use_greater &&
5465 		    tp->t_srtt &&
5466 		    (srtt < rack_grab_rtt(tp, rack))) {
5467 			srtt = rack_grab_rtt(tp, rack);
5468 		}
5469 		thresh = rack_calc_thresh_tlp(tp, rack, rsm, srtt);
5470 		if (thresh > time_since_sent) {
5471 			to = thresh - time_since_sent;
5472 		} else {
5473 			to = rack->r_ctl.rc_min_to;
5474 			rack_log_alt_to_to_cancel(rack,
5475 						  thresh,		/* flex1 */
5476 						  time_since_sent,	/* flex2 */
5477 						  tstmp_touse,		/* flex3 */
5478 						  rack->r_ctl.rc_tlp_rxt_last_time, /* flex4 */
5479 						  (uint32_t)rsm->r_tim_lastsent[idx],
5480 						  srtt,
5481 						  idx, 99);
5482 		}
5483 		if (to < rack_tlp_min) {
5484 			to = rack_tlp_min;
5485 		}
5486 		if (to > TICKS_2_USEC(TCPTV_REXMTMAX)) {
5487 			/*
5488 			 * If the TLP time works out to larger than the max
5489 			 * RTO lets not do TLP.. just RTO.
5490 			 */
5491 			goto activate_rxt;
5492 		}
5493 	}
5494 	if (is_tlp_timer == 0) {
5495 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_RACK;
5496 	} else {
5497 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_TLP;
5498 	}
5499 	if (to == 0)
5500 		to = 1;
5501 	return (to);
5502 }
5503 
5504 static void
5505 rack_enter_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
5506 {
5507 	if (rack->rc_in_persist == 0) {
5508 		if (tp->t_flags & TF_GPUTINPROG) {
5509 			/*
5510 			 * Stop the goodput now, the calling of the
5511 			 * measurement function clears the flag.
5512 			 */
5513 			rack_do_goodput_measurement(tp, rack, tp->snd_una, __LINE__);
5514 		}
5515 #ifdef NETFLIX_SHARED_CWND
5516 		if (rack->r_ctl.rc_scw) {
5517 			tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
5518 			rack->rack_scwnd_is_idle = 1;
5519 		}
5520 #endif
5521 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
5522 		if (rack->r_ctl.rc_went_idle_time == 0)
5523 			rack->r_ctl.rc_went_idle_time = 1;
5524 		rack_timer_cancel(tp, rack, cts, __LINE__);
5525 		tp->t_rxtshift = 0;
5526 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
5527 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
5528 		rack->rc_in_persist = 1;
5529 	}
5530 }
5531 
5532 static void
5533 rack_exit_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
5534 {
5535 	if (rack->rc_inp->inp_in_hpts) {
5536 		tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
5537 		rack->r_ctl.rc_hpts_flags = 0;
5538 	}
5539 #ifdef NETFLIX_SHARED_CWND
5540 	if (rack->r_ctl.rc_scw) {
5541 		tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
5542 		rack->rack_scwnd_is_idle = 0;
5543 	}
5544 #endif
5545 	if (rack->rc_gp_dyn_mul &&
5546 	    (rack->use_fixed_rate == 0) &&
5547 	    (rack->rc_always_pace)) {
5548 		/*
5549 		 * Do we count this as if a probe-rtt just
5550 		 * finished?
5551 		 */
5552 		uint32_t time_idle, idle_min;
5553 
5554 		time_idle = tcp_get_usecs(NULL) - rack->r_ctl.rc_went_idle_time;
5555 		idle_min = rack_min_probertt_hold;
5556 		if (rack_probertt_gpsrtt_cnt_div) {
5557 			uint64_t extra;
5558 			extra = (uint64_t)rack->r_ctl.rc_gp_srtt *
5559 				(uint64_t)rack_probertt_gpsrtt_cnt_mul;
5560 			extra /= (uint64_t)rack_probertt_gpsrtt_cnt_div;
5561 			idle_min += (uint32_t)extra;
5562 		}
5563 		if (time_idle >= idle_min) {
5564 			/* Yes, we count it as a probe-rtt. */
5565 			uint32_t us_cts;
5566 
5567 			us_cts = tcp_get_usecs(NULL);
5568 			if (rack->in_probe_rtt == 0) {
5569 				rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
5570 				rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
5571 				rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
5572 				rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
5573 			} else {
5574 				rack_exit_probertt(rack, us_cts);
5575 			}
5576 		}
5577 	}
5578 	rack->rc_in_persist = 0;
5579 	rack->r_ctl.rc_went_idle_time = 0;
5580 	tp->t_rxtshift = 0;
5581 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
5582 	   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
5583 	rack->r_ctl.rc_agg_delayed = 0;
5584 	rack->r_early = 0;
5585 	rack->r_late = 0;
5586 	rack->r_ctl.rc_agg_early = 0;
5587 }
5588 
5589 static void
5590 rack_log_hpts_diag(struct tcp_rack *rack, uint32_t cts,
5591 		   struct hpts_diag *diag, struct timeval *tv)
5592 {
5593 	if (rack_verbose_logging && rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
5594 		union tcp_log_stackspecific log;
5595 
5596 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5597 		log.u_bbr.flex1 = diag->p_nxt_slot;
5598 		log.u_bbr.flex2 = diag->p_cur_slot;
5599 		log.u_bbr.flex3 = diag->slot_req;
5600 		log.u_bbr.flex4 = diag->inp_hptsslot;
5601 		log.u_bbr.flex5 = diag->slot_remaining;
5602 		log.u_bbr.flex6 = diag->need_new_to;
5603 		log.u_bbr.flex7 = diag->p_hpts_active;
5604 		log.u_bbr.flex8 = diag->p_on_min_sleep;
5605 		/* Hijack other fields as needed */
5606 		log.u_bbr.epoch = diag->have_slept;
5607 		log.u_bbr.lt_epoch = diag->yet_to_sleep;
5608 		log.u_bbr.pkts_out = diag->co_ret;
5609 		log.u_bbr.applimited = diag->hpts_sleep_time;
5610 		log.u_bbr.delivered = diag->p_prev_slot;
5611 		log.u_bbr.inflight = diag->p_runningtick;
5612 		log.u_bbr.bw_inuse = diag->wheel_tick;
5613 		log.u_bbr.rttProp = diag->wheel_cts;
5614 		log.u_bbr.timeStamp = cts;
5615 		log.u_bbr.delRate = diag->maxticks;
5616 		log.u_bbr.cur_del_rate = diag->p_curtick;
5617 		log.u_bbr.cur_del_rate <<= 32;
5618 		log.u_bbr.cur_del_rate |= diag->p_lasttick;
5619 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
5620 		    &rack->rc_inp->inp_socket->so_rcv,
5621 		    &rack->rc_inp->inp_socket->so_snd,
5622 		    BBR_LOG_HPTSDIAG, 0,
5623 		    0, &log, false, tv);
5624 	}
5625 
5626 }
5627 
5628 static void
5629 rack_log_wakeup(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb, uint32_t len, int type)
5630 {
5631 	if (rack_verbose_logging && rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
5632 		union tcp_log_stackspecific log;
5633 		struct timeval tv;
5634 
5635 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5636 		log.u_bbr.flex1 = sb->sb_flags;
5637 		log.u_bbr.flex2 = len;
5638 		log.u_bbr.flex3 = sb->sb_state;
5639 		log.u_bbr.flex8 = type;
5640 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5641 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
5642 		    &rack->rc_inp->inp_socket->so_rcv,
5643 		    &rack->rc_inp->inp_socket->so_snd,
5644 		    TCP_LOG_SB_WAKE, 0,
5645 		    len, &log, false, &tv);
5646 	}
5647 }
5648 
5649 static void
5650 rack_start_hpts_timer(struct tcp_rack *rack, struct tcpcb *tp, uint32_t cts,
5651       int32_t slot, uint32_t tot_len_this_send, int sup_rack)
5652 {
5653 	struct hpts_diag diag;
5654 	struct inpcb *inp;
5655 	struct timeval tv;
5656 	uint32_t delayed_ack = 0;
5657 	uint32_t hpts_timeout;
5658 	uint32_t entry_slot = slot;
5659 	uint8_t stopped;
5660 	uint32_t left = 0;
5661 	uint32_t us_cts;
5662 
5663 	inp = tp->t_inpcb;
5664 	if ((tp->t_state == TCPS_CLOSED) ||
5665 	    (tp->t_state == TCPS_LISTEN)) {
5666 		return;
5667 	}
5668 	if (inp->inp_in_hpts) {
5669 		/* Already on the pacer */
5670 		return;
5671 	}
5672 	stopped = rack->rc_tmr_stopped;
5673 	if (stopped && TSTMP_GT(rack->r_ctl.rc_timer_exp, cts)) {
5674 		left = rack->r_ctl.rc_timer_exp - cts;
5675 	}
5676 	rack->r_ctl.rc_timer_exp = 0;
5677 	rack->r_ctl.rc_hpts_flags = 0;
5678 	us_cts = tcp_get_usecs(&tv);
5679 	/* Now early/late accounting */
5680 	rack_log_pacing_delay_calc(rack, entry_slot, slot, 0, 0, 0, 26, __LINE__, NULL);
5681 	if (rack->r_early && (rack->rc_ack_can_sendout_data == 0)) {
5682 		/*
5683 		 * We have a early carry over set,
5684 		 * we can always add more time so we
5685 		 * can always make this compensation.
5686 		 *
5687 		 * Note if ack's are allowed to wake us do not
5688 		 * penalize the next timer for being awoke
5689 		 * by an ack aka the rc_agg_early (non-paced mode).
5690 		 */
5691 		slot += rack->r_ctl.rc_agg_early;
5692 		rack->r_early = 0;
5693 		rack->r_ctl.rc_agg_early = 0;
5694 	}
5695 	if (rack->r_late) {
5696 		/*
5697 		 * This is harder, we can
5698 		 * compensate some but it
5699 		 * really depends on what
5700 		 * the current pacing time is.
5701 		 */
5702 		if (rack->r_ctl.rc_agg_delayed >= slot) {
5703 			/*
5704 			 * We can't compensate for it all.
5705 			 * And we have to have some time
5706 			 * on the clock. We always have a min
5707 			 * 10 slots (10 x 10 i.e. 100 usecs).
5708 			 */
5709 			if (slot <= HPTS_TICKS_PER_USEC) {
5710 				/* We gain delay */
5711 				rack->r_ctl.rc_agg_delayed += (HPTS_TICKS_PER_USEC - slot);
5712 				slot = HPTS_TICKS_PER_USEC;
5713 			} else {
5714 				/* We take off some */
5715 				rack->r_ctl.rc_agg_delayed -= (slot - HPTS_TICKS_PER_USEC);
5716 				slot = HPTS_TICKS_PER_USEC;
5717 			}
5718 		} else {
5719 			slot -= rack->r_ctl.rc_agg_delayed;
5720 			rack->r_ctl.rc_agg_delayed = 0;
5721 			/* Make sure we have 100 useconds at minimum */
5722 			if (slot < HPTS_TICKS_PER_USEC) {
5723 				rack->r_ctl.rc_agg_delayed = HPTS_TICKS_PER_USEC - slot;
5724 				slot = HPTS_TICKS_PER_USEC;
5725 			}
5726 			if (rack->r_ctl.rc_agg_delayed == 0)
5727 				rack->r_late = 0;
5728 		}
5729 	}
5730 	if (slot) {
5731 		/* We are pacing too */
5732 		rack->r_ctl.rc_hpts_flags |= PACE_PKT_OUTPUT;
5733 	}
5734 	hpts_timeout = rack_timer_start(tp, rack, cts, sup_rack);
5735 #ifdef NETFLIX_EXP_DETECTION
5736 	if (rack->sack_attack_disable &&
5737 	    (slot < tcp_sad_pacing_interval)) {
5738 		/*
5739 		 * We have a potential attacker on
5740 		 * the line. We have possibly some
5741 		 * (or now) pacing time set. We want to
5742 		 * slow down the processing of sacks by some
5743 		 * amount (if it is an attacker). Set the default
5744 		 * slot for attackers in place (unless the orginal
5745 		 * interval is longer). Its stored in
5746 		 * micro-seconds, so lets convert to msecs.
5747 		 */
5748 		slot = tcp_sad_pacing_interval;
5749 	}
5750 #endif
5751 	if (tp->t_flags & TF_DELACK) {
5752 		delayed_ack = TICKS_2_USEC(tcp_delacktime);
5753 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_DELACK;
5754 	}
5755 	if (delayed_ack && ((hpts_timeout == 0) ||
5756 			    (delayed_ack < hpts_timeout)))
5757 		hpts_timeout = delayed_ack;
5758 	else
5759 		rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
5760 	/*
5761 	 * If no timers are going to run and we will fall off the hptsi
5762 	 * wheel, we resort to a keep-alive timer if its configured.
5763 	 */
5764 	if ((hpts_timeout == 0) &&
5765 	    (slot == 0)) {
5766 		if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
5767 		    (tp->t_state <= TCPS_CLOSING)) {
5768 			/*
5769 			 * Ok we have no timer (persists, rack, tlp, rxt  or
5770 			 * del-ack), we don't have segments being paced. So
5771 			 * all that is left is the keepalive timer.
5772 			 */
5773 			if (TCPS_HAVEESTABLISHED(tp->t_state)) {
5774 				/* Get the established keep-alive time */
5775 				hpts_timeout = TICKS_2_USEC(TP_KEEPIDLE(tp));
5776 			} else {
5777 				/*
5778 				 * Get the initial setup keep-alive time,
5779 				 * note that this is probably not going to
5780 				 * happen, since rack will be running a rxt timer
5781 				 * if a SYN of some sort is outstanding. It is
5782 				 * actually handled in rack_timeout_rxt().
5783 				 */
5784 				hpts_timeout = TICKS_2_USEC(TP_KEEPINIT(tp));
5785 			}
5786 			rack->r_ctl.rc_hpts_flags |= PACE_TMR_KEEP;
5787 			if (rack->in_probe_rtt) {
5788 				/*
5789 				 * We want to instead not wake up a long time from
5790 				 * now but to wake up about the time we would
5791 				 * exit probe-rtt and initiate a keep-alive ack.
5792 				 * This will get us out of probe-rtt and update
5793 				 * our min-rtt.
5794 				 */
5795 				hpts_timeout = rack_min_probertt_hold;
5796 			}
5797 		}
5798 	}
5799 	if (left && (stopped & (PACE_TMR_KEEP | PACE_TMR_DELACK)) ==
5800 	    (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK)) {
5801 		/*
5802 		 * RACK, TLP, persists and RXT timers all are restartable
5803 		 * based on actions input .. i.e we received a packet (ack
5804 		 * or sack) and that changes things (rw, or snd_una etc).
5805 		 * Thus we can restart them with a new value. For
5806 		 * keep-alive, delayed_ack we keep track of what was left
5807 		 * and restart the timer with a smaller value.
5808 		 */
5809 		if (left < hpts_timeout)
5810 			hpts_timeout = left;
5811 	}
5812 	if (hpts_timeout) {
5813 		/*
5814 		 * Hack alert for now we can't time-out over 2,147,483
5815 		 * seconds (a bit more than 596 hours), which is probably ok
5816 		 * :).
5817 		 */
5818 		if (hpts_timeout > 0x7ffffffe)
5819 			hpts_timeout = 0x7ffffffe;
5820 		rack->r_ctl.rc_timer_exp = cts + hpts_timeout;
5821 	}
5822 	rack_log_pacing_delay_calc(rack, entry_slot, slot, hpts_timeout, 0, 0, 27, __LINE__, NULL);
5823 	if ((rack->gp_ready == 0) &&
5824 	    (rack->use_fixed_rate == 0) &&
5825 	    (hpts_timeout < slot) &&
5826 	    (rack->r_ctl.rc_hpts_flags & (PACE_TMR_TLP|PACE_TMR_RXT))) {
5827 		/*
5828 		 * We have no good estimate yet for the
5829 		 * old clunky burst mitigation or the
5830 		 * real pacing. And the tlp or rxt is smaller
5831 		 * than the pacing calculation. Lets not
5832 		 * pace that long since we know the calculation
5833 		 * so far is not accurate.
5834 		 */
5835 		slot = hpts_timeout;
5836 	}
5837 	rack->r_ctl.last_pacing_time = slot;
5838 	/**
5839 	 * Turn off all the flags for queuing by default. The
5840 	 * flags have important meanings to what happens when
5841 	 * LRO interacts with the transport. Most likely (by default now)
5842 	 * mbuf_queueing and ack compression are on. So the transport
5843 	 * has a couple of flags that control what happens (if those
5844 	 * are not on then these flags won't have any effect since it
5845 	 * won't go through the queuing LRO path).
5846 	 *
5847 	 * INP_MBUF_QUEUE_READY - This flags says that I am busy
5848 	 *                        pacing output, so don't disturb. But
5849 	 *                        it also means LRO can wake me if there
5850 	 *                        is a SACK arrival.
5851 	 *
5852 	 * INP_DONT_SACK_QUEUE - This flag is used in conjunction
5853 	 *                       with the above flag (QUEUE_READY) and
5854 	 *                       when present it says don't even wake me
5855 	 *                       if a SACK arrives.
5856 	 *
5857 	 * The idea behind these flags is that if we are pacing we
5858 	 * set the MBUF_QUEUE_READY and only get woken up if
5859 	 * a SACK arrives (which could change things) or if
5860 	 * our pacing timer expires. If, however, we have a rack
5861 	 * timer running, then we don't even want a sack to wake
5862 	 * us since the rack timer has to expire before we can send.
5863 	 *
5864 	 * Other cases should usually have none of the flags set
5865 	 * so LRO can call into us.
5866 	 */
5867 	inp->inp_flags2 &= ~(INP_DONT_SACK_QUEUE|INP_MBUF_QUEUE_READY);
5868 	if (slot) {
5869 		rack->r_ctl.rc_last_output_to = us_cts + slot;
5870 		/*
5871 		 * A pacing timer (slot) is being set, in
5872 		 * such a case we cannot send (we are blocked by
5873 		 * the timer). So lets tell LRO that it should not
5874 		 * wake us unless there is a SACK. Note this only
5875 		 * will be effective if mbuf queueing is on or
5876 		 * compressed acks are being processed.
5877 		 */
5878 		inp->inp_flags2 |= INP_MBUF_QUEUE_READY;
5879 		/*
5880 		 * But wait if we have a Rack timer running
5881 		 * even a SACK should not disturb us (with
5882 		 * the exception of r_rr_config 3).
5883 		 */
5884 		if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK) &&
5885 		    (rack->r_rr_config != 3))
5886 			inp->inp_flags2 |= INP_DONT_SACK_QUEUE;
5887 		if (rack->rc_ack_can_sendout_data) {
5888 			/*
5889 			 * Ahh but wait, this is that special case
5890 			 * where the pacing timer can be disturbed
5891 			 * backout the changes (used for non-paced
5892 			 * burst limiting).
5893 			 */
5894 			inp->inp_flags2 &= ~(INP_DONT_SACK_QUEUE|INP_MBUF_QUEUE_READY);
5895 		}
5896 		if ((rack->use_rack_rr) &&
5897 		    (rack->r_rr_config < 2) &&
5898 		    ((hpts_timeout) && (hpts_timeout < slot))) {
5899 			/*
5900 			 * Arrange for the hpts to kick back in after the
5901 			 * t-o if the t-o does not cause a send.
5902 			 */
5903 			(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_USEC_TO_SLOTS(hpts_timeout),
5904 						   __LINE__, &diag);
5905 			rack_log_hpts_diag(rack, us_cts, &diag, &tv);
5906 			rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
5907 		} else {
5908 			(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_USEC_TO_SLOTS(slot),
5909 						   __LINE__, &diag);
5910 			rack_log_hpts_diag(rack, us_cts, &diag, &tv);
5911 			rack_log_to_start(rack, cts, hpts_timeout, slot, 1);
5912 		}
5913 	} else if (hpts_timeout) {
5914 		/*
5915 		 * With respect to inp_flags2 here, lets let any new acks wake
5916 		 * us up here. Since we are not pacing (no pacing timer), output
5917 		 * can happen so we should let it. If its a Rack timer, then any inbound
5918 		 * packet probably won't change the sending (we will be blocked)
5919 		 * but it may change the prr stats so letting it in (the set defaults
5920 		 * at the start of this block) are good enough.
5921 		 */
5922 		(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_USEC_TO_SLOTS(hpts_timeout),
5923 					   __LINE__, &diag);
5924 		rack_log_hpts_diag(rack, us_cts, &diag, &tv);
5925 		rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
5926 	} else {
5927 		/* No timer starting */
5928 #ifdef INVARIANTS
5929 		if (SEQ_GT(tp->snd_max, tp->snd_una)) {
5930 			panic("tp:%p rack:%p tlts:%d cts:%u slot:%u pto:%u -- no timer started?",
5931 			    tp, rack, tot_len_this_send, cts, slot, hpts_timeout);
5932 		}
5933 #endif
5934 	}
5935 	rack->rc_tmr_stopped = 0;
5936 	if (slot)
5937 		rack_log_type_bbrsnd(rack, tot_len_this_send, slot, us_cts, &tv);
5938 }
5939 
5940 /*
5941  * RACK Timer, here we simply do logging and house keeping.
5942  * the normal rack_output() function will call the
5943  * appropriate thing to check if we need to do a RACK retransmit.
5944  * We return 1, saying don't proceed with rack_output only
5945  * when all timers have been stopped (destroyed PCB?).
5946  */
5947 static int
5948 rack_timeout_rack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
5949 {
5950 	/*
5951 	 * This timer simply provides an internal trigger to send out data.
5952 	 * The check_recovery_mode call will see if there are needed
5953 	 * retransmissions, if so we will enter fast-recovery. The output
5954 	 * call may or may not do the same thing depending on sysctl
5955 	 * settings.
5956 	 */
5957 	struct rack_sendmap *rsm;
5958 
5959 	if (tp->t_timers->tt_flags & TT_STOPPED) {
5960 		return (1);
5961 	}
5962 	counter_u64_add(rack_to_tot, 1);
5963 	if (rack->r_state && (rack->r_state != tp->t_state))
5964 		rack_set_state(tp, rack);
5965 	rack->rc_on_min_to = 0;
5966 	rsm = rack_check_recovery_mode(tp, cts);
5967 	rack_log_to_event(rack, RACK_TO_FRM_RACK, rsm);
5968 	if (rsm) {
5969 		rack->r_ctl.rc_resend = rsm;
5970 		rack->r_timer_override = 1;
5971 		if (rack->use_rack_rr) {
5972 			/*
5973 			 * Don't accumulate extra pacing delay
5974 			 * we are allowing the rack timer to
5975 			 * over-ride pacing i.e. rrr takes precedence
5976 			 * if the pacing interval is longer than the rrr
5977 			 * time (in other words we get the min pacing
5978 			 * time versus rrr pacing time).
5979 			 */
5980 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
5981 		}
5982 	}
5983 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RACK;
5984 	if (rsm == NULL) {
5985 		/* restart a timer and return 1 */
5986 		rack_start_hpts_timer(rack, tp, cts,
5987 				      0, 0, 0);
5988 		return (1);
5989 	}
5990 	return (0);
5991 }
5992 
5993 static void
5994 rack_adjust_orig_mlen(struct rack_sendmap *rsm)
5995 {
5996 	if (rsm->m->m_len > rsm->orig_m_len) {
5997 		/*
5998 		 * Mbuf grew, caused by sbcompress, our offset does
5999 		 * not change.
6000 		 */
6001 		rsm->orig_m_len = rsm->m->m_len;
6002 	} else if (rsm->m->m_len < rsm->orig_m_len) {
6003 		/*
6004 		 * Mbuf shrank, trimmed off the top by an ack, our
6005 		 * offset changes.
6006 		 */
6007 		rsm->soff -= (rsm->orig_m_len - rsm->m->m_len);
6008 		rsm->orig_m_len = rsm->m->m_len;
6009 	}
6010 }
6011 
6012 static void
6013 rack_setup_offset_for_rsm(struct rack_sendmap *src_rsm, struct rack_sendmap *rsm)
6014 {
6015 	struct mbuf *m;
6016 	uint32_t soff;
6017 
6018 	if (src_rsm->m && (src_rsm->orig_m_len != src_rsm->m->m_len)) {
6019 		/* Fix up the orig_m_len and possibly the mbuf offset */
6020 		rack_adjust_orig_mlen(src_rsm);
6021 	}
6022 	m = src_rsm->m;
6023 	soff = src_rsm->soff + (src_rsm->r_end - src_rsm->r_start);
6024 	while (soff >= m->m_len) {
6025 		/* Move out past this mbuf */
6026 		soff -= m->m_len;
6027 		m = m->m_next;
6028 		KASSERT((m != NULL),
6029 			("rsm:%p nrsm:%p hit at soff:%u null m",
6030 			 src_rsm, rsm, soff));
6031 	}
6032 	rsm->m = m;
6033 	rsm->soff = soff;
6034 	rsm->orig_m_len = m->m_len;
6035 }
6036 
6037 static __inline void
6038 rack_clone_rsm(struct tcp_rack *rack, struct rack_sendmap *nrsm,
6039 	       struct rack_sendmap *rsm, uint32_t start)
6040 {
6041 	int idx;
6042 
6043 	nrsm->r_start = start;
6044 	nrsm->r_end = rsm->r_end;
6045 	nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
6046 	nrsm->r_flags = rsm->r_flags;
6047 	nrsm->r_dupack = rsm->r_dupack;
6048 	nrsm->r_no_rtt_allowed = rsm->r_no_rtt_allowed;
6049 	nrsm->r_rtr_bytes = 0;
6050 	rsm->r_end = nrsm->r_start;
6051 	nrsm->r_just_ret = rsm->r_just_ret;
6052 	for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
6053 		nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
6054 	}
6055 	/* Now if we have SYN flag we keep it on the left edge */
6056 	if (nrsm->r_flags & RACK_HAS_SYN)
6057 		nrsm->r_flags &= ~RACK_HAS_SYN;
6058 	/* Now if we have a FIN flag we keep it on the right edge */
6059 	if (rsm->r_flags & RACK_HAS_FIN)
6060 		rsm->r_flags &= ~RACK_HAS_FIN;
6061 	/* Push bit must go to the right edge as well */
6062 	if (rsm->r_flags & RACK_HAD_PUSH)
6063 		rsm->r_flags &= ~RACK_HAD_PUSH;
6064 
6065 	/*
6066 	 * Now we need to find nrsm's new location in the mbuf chain
6067 	 * we basically calculate a new offset, which is soff +
6068 	 * how much is left in original rsm. Then we walk out the mbuf
6069 	 * chain to find the righ postion, it may be the same mbuf
6070 	 * or maybe not.
6071 	 */
6072 	KASSERT(((rsm->m != NULL) ||
6073 		 (rsm->r_flags & (RACK_HAS_SYN|RACK_HAS_FIN))),
6074 		("rsm:%p nrsm:%p rack:%p -- rsm->m is NULL?", rsm, nrsm, rack));
6075 	if (rsm->m)
6076 		rack_setup_offset_for_rsm(rsm, nrsm);
6077 }
6078 
6079 static struct rack_sendmap *
6080 rack_merge_rsm(struct tcp_rack *rack,
6081 	       struct rack_sendmap *l_rsm,
6082 	       struct rack_sendmap *r_rsm)
6083 {
6084 	/*
6085 	 * We are merging two ack'd RSM's,
6086 	 * the l_rsm is on the left (lower seq
6087 	 * values) and the r_rsm is on the right
6088 	 * (higher seq value). The simplest way
6089 	 * to merge these is to move the right
6090 	 * one into the left. I don't think there
6091 	 * is any reason we need to try to find
6092 	 * the oldest (or last oldest retransmitted).
6093 	 */
6094 	struct rack_sendmap *rm;
6095 
6096 	rack_log_map_chg(rack->rc_tp, rack, NULL,
6097 			 l_rsm, r_rsm, MAP_MERGE, r_rsm->r_end, __LINE__);
6098 	l_rsm->r_end = r_rsm->r_end;
6099 	if (l_rsm->r_dupack < r_rsm->r_dupack)
6100 		l_rsm->r_dupack = r_rsm->r_dupack;
6101 	if (r_rsm->r_rtr_bytes)
6102 		l_rsm->r_rtr_bytes += r_rsm->r_rtr_bytes;
6103 	if (r_rsm->r_in_tmap) {
6104 		/* This really should not happen */
6105 		TAILQ_REMOVE(&rack->r_ctl.rc_tmap, r_rsm, r_tnext);
6106 		r_rsm->r_in_tmap = 0;
6107 	}
6108 
6109 	/* Now the flags */
6110 	if (r_rsm->r_flags & RACK_HAS_FIN)
6111 		l_rsm->r_flags |= RACK_HAS_FIN;
6112 	if (r_rsm->r_flags & RACK_TLP)
6113 		l_rsm->r_flags |= RACK_TLP;
6114 	if (r_rsm->r_flags & RACK_RWND_COLLAPSED)
6115 		l_rsm->r_flags |= RACK_RWND_COLLAPSED;
6116 	if ((r_rsm->r_flags & RACK_APP_LIMITED)  &&
6117 	    ((l_rsm->r_flags & RACK_APP_LIMITED) == 0)) {
6118 		/*
6119 		 * If both are app-limited then let the
6120 		 * free lower the count. If right is app
6121 		 * limited and left is not, transfer.
6122 		 */
6123 		l_rsm->r_flags |= RACK_APP_LIMITED;
6124 		r_rsm->r_flags &= ~RACK_APP_LIMITED;
6125 		if (r_rsm == rack->r_ctl.rc_first_appl)
6126 			rack->r_ctl.rc_first_appl = l_rsm;
6127 	}
6128 	rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, r_rsm);
6129 #ifdef INVARIANTS
6130 	if (rm != r_rsm) {
6131 		panic("removing head in rack:%p rsm:%p rm:%p",
6132 		      rack, r_rsm, rm);
6133 	}
6134 #endif
6135 	if ((r_rsm->r_limit_type == 0) && (l_rsm->r_limit_type != 0)) {
6136 		/* Transfer the split limit to the map we free */
6137 		r_rsm->r_limit_type = l_rsm->r_limit_type;
6138 		l_rsm->r_limit_type = 0;
6139 	}
6140 	rack_free(rack, r_rsm);
6141 	return (l_rsm);
6142 }
6143 
6144 /*
6145  * TLP Timer, here we simply setup what segment we want to
6146  * have the TLP expire on, the normal rack_output() will then
6147  * send it out.
6148  *
6149  * We return 1, saying don't proceed with rack_output only
6150  * when all timers have been stopped (destroyed PCB?).
6151  */
6152 static int
6153 rack_timeout_tlp(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6154 {
6155 	/*
6156 	 * Tail Loss Probe.
6157 	 */
6158 	struct rack_sendmap *rsm = NULL;
6159 	struct rack_sendmap *insret;
6160 	struct socket *so;
6161 	uint32_t amm;
6162 	uint32_t out, avail;
6163 	int collapsed_win = 0;
6164 
6165 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6166 		return (1);
6167 	}
6168 	if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
6169 		/* Its not time yet */
6170 		return (0);
6171 	}
6172 	if (ctf_progress_timeout_check(tp, true)) {
6173 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
6174 		tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
6175 		return (1);
6176 	}
6177 	/*
6178 	 * A TLP timer has expired. We have been idle for 2 rtts. So we now
6179 	 * need to figure out how to force a full MSS segment out.
6180 	 */
6181 	rack_log_to_event(rack, RACK_TO_FRM_TLP, NULL);
6182 	rack->r_ctl.retran_during_recovery = 0;
6183 	rack->r_ctl.dsack_byte_cnt = 0;
6184 	counter_u64_add(rack_tlp_tot, 1);
6185 	if (rack->r_state && (rack->r_state != tp->t_state))
6186 		rack_set_state(tp, rack);
6187 	so = tp->t_inpcb->inp_socket;
6188 	avail = sbavail(&so->so_snd);
6189 	out = tp->snd_max - tp->snd_una;
6190 	if (out > tp->snd_wnd) {
6191 		/* special case, we need a retransmission */
6192 		collapsed_win = 1;
6193 		goto need_retran;
6194 	}
6195 	/*
6196 	 * Check our send oldest always settings, and if
6197 	 * there is an oldest to send jump to the need_retran.
6198 	 */
6199 	if (rack_always_send_oldest && (TAILQ_EMPTY(&rack->r_ctl.rc_tmap) == 0))
6200 		goto need_retran;
6201 
6202 	if (avail > out) {
6203 		/* New data is available */
6204 		amm = avail - out;
6205 		if (amm > ctf_fixed_maxseg(tp)) {
6206 			amm = ctf_fixed_maxseg(tp);
6207 			if ((amm + out) > tp->snd_wnd) {
6208 				/* We are rwnd limited */
6209 				goto need_retran;
6210 			}
6211 		} else if (amm < ctf_fixed_maxseg(tp)) {
6212 			/* not enough to fill a MTU */
6213 			goto need_retran;
6214 		}
6215 		if (IN_FASTRECOVERY(tp->t_flags)) {
6216 			/* Unlikely */
6217 			if (rack->rack_no_prr == 0) {
6218 				if (out + amm <= tp->snd_wnd) {
6219 					rack->r_ctl.rc_prr_sndcnt = amm;
6220 					rack_log_to_prr(rack, 4, 0);
6221 				}
6222 			} else
6223 				goto need_retran;
6224 		} else {
6225 			/* Set the send-new override */
6226 			if (out + amm <= tp->snd_wnd)
6227 				rack->r_ctl.rc_tlp_new_data = amm;
6228 			else
6229 				goto need_retran;
6230 		}
6231 		rack->r_ctl.rc_tlpsend = NULL;
6232 		counter_u64_add(rack_tlp_newdata, 1);
6233 		goto send;
6234 	}
6235 need_retran:
6236 	/*
6237 	 * Ok we need to arrange the last un-acked segment to be re-sent, or
6238 	 * optionally the first un-acked segment.
6239 	 */
6240 	if (collapsed_win == 0) {
6241 		if (rack_always_send_oldest)
6242 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
6243 		else {
6244 			rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6245 			if (rsm && (rsm->r_flags & (RACK_ACKED | RACK_HAS_FIN))) {
6246 				rsm = rack_find_high_nonack(rack, rsm);
6247 			}
6248 		}
6249 		if (rsm == NULL) {
6250 			counter_u64_add(rack_tlp_does_nada, 1);
6251 #ifdef TCP_BLACKBOX
6252 			tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
6253 #endif
6254 			goto out;
6255 		}
6256 	} else {
6257 		/*
6258 		 * We must find the last segment
6259 		 * that was acceptable by the client.
6260 		 */
6261 		RB_FOREACH_REVERSE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
6262 			if ((rsm->r_flags & RACK_RWND_COLLAPSED) == 0) {
6263 				/* Found one */
6264 				break;
6265 			}
6266 		}
6267 		if (rsm == NULL) {
6268 			/* None? if so send the first */
6269 			rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6270 			if (rsm == NULL) {
6271 				counter_u64_add(rack_tlp_does_nada, 1);
6272 #ifdef TCP_BLACKBOX
6273 				tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
6274 #endif
6275 				goto out;
6276 			}
6277 		}
6278 	}
6279 	if ((rsm->r_end - rsm->r_start) > ctf_fixed_maxseg(tp)) {
6280 		/*
6281 		 * We need to split this the last segment in two.
6282 		 */
6283 		struct rack_sendmap *nrsm;
6284 
6285 		nrsm = rack_alloc_full_limit(rack);
6286 		if (nrsm == NULL) {
6287 			/*
6288 			 * No memory to split, we will just exit and punt
6289 			 * off to the RXT timer.
6290 			 */
6291 			counter_u64_add(rack_tlp_does_nada, 1);
6292 			goto out;
6293 		}
6294 		rack_clone_rsm(rack, nrsm, rsm,
6295 			       (rsm->r_end - ctf_fixed_maxseg(tp)));
6296 		rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
6297 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
6298 #ifdef INVARIANTS
6299 		if (insret != NULL) {
6300 			panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
6301 			      nrsm, insret, rack, rsm);
6302 		}
6303 #endif
6304 		if (rsm->r_in_tmap) {
6305 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
6306 			nrsm->r_in_tmap = 1;
6307 		}
6308 		rsm->r_flags &= (~RACK_HAS_FIN);
6309 		rsm = nrsm;
6310 	}
6311 	rack->r_ctl.rc_tlpsend = rsm;
6312 send:
6313 	rack->r_timer_override = 1;
6314 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
6315 	return (0);
6316 out:
6317 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
6318 	return (0);
6319 }
6320 
6321 /*
6322  * Delayed ack Timer, here we simply need to setup the
6323  * ACK_NOW flag and remove the DELACK flag. From there
6324  * the output routine will send the ack out.
6325  *
6326  * We only return 1, saying don't proceed, if all timers
6327  * are stopped (destroyed PCB?).
6328  */
6329 static int
6330 rack_timeout_delack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6331 {
6332 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6333 		return (1);
6334 	}
6335 	rack_log_to_event(rack, RACK_TO_FRM_DELACK, NULL);
6336 	tp->t_flags &= ~TF_DELACK;
6337 	tp->t_flags |= TF_ACKNOW;
6338 	KMOD_TCPSTAT_INC(tcps_delack);
6339 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
6340 	return (0);
6341 }
6342 
6343 /*
6344  * Persists timer, here we simply send the
6345  * same thing as a keepalive will.
6346  * the one byte send.
6347  *
6348  * We only return 1, saying don't proceed, if all timers
6349  * are stopped (destroyed PCB?).
6350  */
6351 static int
6352 rack_timeout_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6353 {
6354 	struct tcptemp *t_template;
6355 	struct inpcb *inp;
6356 	int32_t retval = 1;
6357 
6358 	inp = tp->t_inpcb;
6359 
6360 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6361 		return (1);
6362 	}
6363 	if (rack->rc_in_persist == 0)
6364 		return (0);
6365 	if (ctf_progress_timeout_check(tp, false)) {
6366 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
6367 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
6368 		tcp_set_inp_to_drop(inp, ETIMEDOUT);
6369 		return (1);
6370 	}
6371 	KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", __func__, tp));
6372 	/*
6373 	 * Persistence timer into zero window. Force a byte to be output, if
6374 	 * possible.
6375 	 */
6376 	KMOD_TCPSTAT_INC(tcps_persisttimeo);
6377 	/*
6378 	 * Hack: if the peer is dead/unreachable, we do not time out if the
6379 	 * window is closed.  After a full backoff, drop the connection if
6380 	 * the idle time (no responses to probes) reaches the maximum
6381 	 * backoff that we would use if retransmitting.
6382 	 */
6383 	if (tp->t_rxtshift == TCP_MAXRXTSHIFT &&
6384 	    (ticks - tp->t_rcvtime >= tcp_maxpersistidle ||
6385 	     TICKS_2_USEC(ticks - tp->t_rcvtime) >= RACK_REXMTVAL(tp) * tcp_totbackoff)) {
6386 		KMOD_TCPSTAT_INC(tcps_persistdrop);
6387 		retval = 1;
6388 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
6389 		tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT);
6390 		goto out;
6391 	}
6392 	if ((sbavail(&rack->rc_inp->inp_socket->so_snd) == 0) &&
6393 	    tp->snd_una == tp->snd_max)
6394 		rack_exit_persist(tp, rack, cts);
6395 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_PERSIT;
6396 	/*
6397 	 * If the user has closed the socket then drop a persisting
6398 	 * connection after a much reduced timeout.
6399 	 */
6400 	if (tp->t_state > TCPS_CLOSE_WAIT &&
6401 	    (ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) {
6402 		retval = 1;
6403 		KMOD_TCPSTAT_INC(tcps_persistdrop);
6404 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
6405 		tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT);
6406 		goto out;
6407 	}
6408 	t_template = tcpip_maketemplate(rack->rc_inp);
6409 	if (t_template) {
6410 		/* only set it if we were answered */
6411 		if (rack->forced_ack == 0) {
6412 			rack->forced_ack = 1;
6413 			rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
6414 		}
6415 		tcp_respond(tp, t_template->tt_ipgen,
6416 			    &t_template->tt_t, (struct mbuf *)NULL,
6417 			    tp->rcv_nxt, tp->snd_una - 1, 0);
6418 		/* This sends an ack */
6419 		if (tp->t_flags & TF_DELACK)
6420 			tp->t_flags &= ~TF_DELACK;
6421 		free(t_template, M_TEMP);
6422 	}
6423 	if (tp->t_rxtshift < TCP_MAXRXTSHIFT)
6424 		tp->t_rxtshift++;
6425 out:
6426 	rack_log_to_event(rack, RACK_TO_FRM_PERSIST, NULL);
6427 	rack_start_hpts_timer(rack, tp, cts,
6428 			      0, 0, 0);
6429 	return (retval);
6430 }
6431 
6432 /*
6433  * If a keepalive goes off, we had no other timers
6434  * happening. We always return 1 here since this
6435  * routine either drops the connection or sends
6436  * out a segment with respond.
6437  */
6438 static int
6439 rack_timeout_keepalive(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6440 {
6441 	struct tcptemp *t_template;
6442 	struct inpcb *inp;
6443 
6444 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6445 		return (1);
6446 	}
6447 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_KEEP;
6448 	inp = tp->t_inpcb;
6449 	rack_log_to_event(rack, RACK_TO_FRM_KEEP, NULL);
6450 	/*
6451 	 * Keep-alive timer went off; send something or drop connection if
6452 	 * idle for too long.
6453 	 */
6454 	KMOD_TCPSTAT_INC(tcps_keeptimeo);
6455 	if (tp->t_state < TCPS_ESTABLISHED)
6456 		goto dropit;
6457 	if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
6458 	    tp->t_state <= TCPS_CLOSING) {
6459 		if (ticks - tp->t_rcvtime >= TP_KEEPIDLE(tp) + TP_MAXIDLE(tp))
6460 			goto dropit;
6461 		/*
6462 		 * Send a packet designed to force a response if the peer is
6463 		 * up and reachable: either an ACK if the connection is
6464 		 * still alive, or an RST if the peer has closed the
6465 		 * connection due to timeout or reboot. Using sequence
6466 		 * number tp->snd_una-1 causes the transmitted zero-length
6467 		 * segment to lie outside the receive window; by the
6468 		 * protocol spec, this requires the correspondent TCP to
6469 		 * respond.
6470 		 */
6471 		KMOD_TCPSTAT_INC(tcps_keepprobe);
6472 		t_template = tcpip_maketemplate(inp);
6473 		if (t_template) {
6474 			if (rack->forced_ack == 0) {
6475 				rack->forced_ack = 1;
6476 				rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
6477 			}
6478 			tcp_respond(tp, t_template->tt_ipgen,
6479 			    &t_template->tt_t, (struct mbuf *)NULL,
6480 			    tp->rcv_nxt, tp->snd_una - 1, 0);
6481 			free(t_template, M_TEMP);
6482 		}
6483 	}
6484 	rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
6485 	return (1);
6486 dropit:
6487 	KMOD_TCPSTAT_INC(tcps_keepdrops);
6488 	tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
6489 	tcp_set_inp_to_drop(rack->rc_inp, ETIMEDOUT);
6490 	return (1);
6491 }
6492 
6493 /*
6494  * Retransmit helper function, clear up all the ack
6495  * flags and take care of important book keeping.
6496  */
6497 static void
6498 rack_remxt_tmr(struct tcpcb *tp)
6499 {
6500 	/*
6501 	 * The retransmit timer went off, all sack'd blocks must be
6502 	 * un-acked.
6503 	 */
6504 	struct rack_sendmap *rsm, *trsm = NULL;
6505 	struct tcp_rack *rack;
6506 
6507 	rack = (struct tcp_rack *)tp->t_fb_ptr;
6508 	rack_timer_cancel(tp, rack, tcp_get_usecs(NULL), __LINE__);
6509 	rack_log_to_event(rack, RACK_TO_FRM_TMR, NULL);
6510 	if (rack->r_state && (rack->r_state != tp->t_state))
6511 		rack_set_state(tp, rack);
6512 	/*
6513 	 * Ideally we would like to be able to
6514 	 * mark SACK-PASS on anything not acked here.
6515 	 *
6516 	 * However, if we do that we would burst out
6517 	 * all that data 1ms apart. This would be unwise,
6518 	 * so for now we will just let the normal rxt timer
6519 	 * and tlp timer take care of it.
6520 	 *
6521 	 * Also we really need to stick them back in sequence
6522 	 * order. This way we send in the proper order and any
6523 	 * sacks that come floating in will "re-ack" the data.
6524 	 * To do this we zap the tmap with an INIT and then
6525 	 * walk through and place every rsm in the RB tree
6526 	 * back in its seq ordered place.
6527 	 */
6528 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
6529 	RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
6530 		rsm->r_dupack = 0;
6531 		rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
6532 		/* We must re-add it back to the tlist */
6533 		if (trsm == NULL) {
6534 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
6535 		} else {
6536 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, trsm, rsm, r_tnext);
6537 		}
6538 		rsm->r_in_tmap = 1;
6539 		trsm = rsm;
6540 		if (rsm->r_flags & RACK_ACKED)
6541 			rsm->r_flags |= RACK_WAS_ACKED;
6542 		rsm->r_flags &= ~(RACK_ACKED | RACK_SACK_PASSED | RACK_WAS_SACKPASS);
6543 	}
6544 	/* Clear the count (we just un-acked them) */
6545 	rack->r_ctl.rc_last_timeout_snduna = tp->snd_una;
6546 	rack->r_ctl.rc_sacked = 0;
6547 	rack->r_ctl.rc_sacklast = NULL;
6548 	rack->r_ctl.rc_agg_delayed = 0;
6549 	rack->r_early = 0;
6550 	rack->r_ctl.rc_agg_early = 0;
6551 	rack->r_late = 0;
6552 	/* Clear the tlp rtx mark */
6553 	rack->r_ctl.rc_resend = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6554 	if (rack->r_ctl.rc_resend != NULL)
6555 		rack->r_ctl.rc_resend->r_flags |= RACK_TO_REXT;
6556 	rack->r_ctl.rc_prr_sndcnt = 0;
6557 	rack_log_to_prr(rack, 6, 0);
6558 	rack->r_timer_override = 1;
6559 	if ((((tp->t_flags & TF_SACK_PERMIT) == 0)
6560 #ifdef NETFLIX_EXP_DETECTION
6561 	    || (rack->sack_attack_disable != 0)
6562 #endif
6563 		    ) && ((tp->t_flags & TF_SENTFIN) == 0)) {
6564 		/*
6565 		 * For non-sack customers new data
6566 		 * needs to go out as retransmits until
6567 		 * we retransmit up to snd_max.
6568 		 */
6569 		rack->r_must_retran = 1;
6570 		rack->r_ctl.rc_out_at_rto = ctf_flight_size(rack->rc_tp,
6571 						rack->r_ctl.rc_sacked);
6572 	}
6573 	rack->r_ctl.rc_snd_max_at_rto = tp->snd_max;
6574 }
6575 
6576 static void
6577 rack_convert_rtts(struct tcpcb *tp)
6578 {
6579 	if (tp->t_srtt > 1) {
6580 		uint32_t val, frac;
6581 
6582 		val = tp->t_srtt >> TCP_RTT_SHIFT;
6583 		frac = tp->t_srtt & 0x1f;
6584 		tp->t_srtt = TICKS_2_USEC(val);
6585 		/*
6586 		 * frac is the fractional part of the srtt (if any)
6587 		 * but its in ticks and every bit represents
6588 		 * 1/32nd of a hz.
6589 		 */
6590 		if (frac) {
6591 			if (hz == 1000) {
6592 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_MSEC) / (uint64_t)TCP_RTT_SCALE);
6593 			} else {
6594 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_SEC) / ((uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE));
6595 			}
6596 			tp->t_srtt += frac;
6597 		}
6598 	}
6599 	if (tp->t_rttvar) {
6600 		uint32_t val, frac;
6601 
6602 		val = tp->t_rttvar >> TCP_RTTVAR_SHIFT;
6603 		frac = tp->t_rttvar & 0x1f;
6604 		tp->t_rttvar = TICKS_2_USEC(val);
6605 		/*
6606 		 * frac is the fractional part of the srtt (if any)
6607 		 * but its in ticks and every bit represents
6608 		 * 1/32nd of a hz.
6609 		 */
6610 		if (frac) {
6611 			if (hz == 1000) {
6612 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_MSEC) / (uint64_t)TCP_RTT_SCALE);
6613 			} else {
6614 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_SEC) / ((uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE));
6615 			}
6616 			tp->t_rttvar += frac;
6617 		}
6618 	}
6619 	tp->t_rxtcur = RACK_REXMTVAL(tp);
6620 	if (TCPS_HAVEESTABLISHED(tp->t_state)) {
6621 		tp->t_rxtcur += TICKS_2_USEC(tcp_rexmit_slop);
6622 	}
6623 	if (tp->t_rxtcur > rack_rto_max) {
6624 		tp->t_rxtcur = rack_rto_max;
6625 	}
6626 }
6627 
6628 static void
6629 rack_cc_conn_init(struct tcpcb *tp)
6630 {
6631 	struct tcp_rack *rack;
6632 	uint32_t srtt;
6633 
6634 	rack = (struct tcp_rack *)tp->t_fb_ptr;
6635 	srtt = tp->t_srtt;
6636 	cc_conn_init(tp);
6637 	/*
6638 	 * Now convert to rack's internal format,
6639 	 * if required.
6640 	 */
6641 	if ((srtt == 0) && (tp->t_srtt != 0))
6642 		rack_convert_rtts(tp);
6643 	/*
6644 	 * We want a chance to stay in slowstart as
6645 	 * we create a connection. TCP spec says that
6646 	 * initially ssthresh is infinite. For our
6647 	 * purposes that is the snd_wnd.
6648 	 */
6649 	if (tp->snd_ssthresh < tp->snd_wnd) {
6650 		tp->snd_ssthresh = tp->snd_wnd;
6651 	}
6652 	/*
6653 	 * We also want to assure a IW worth of
6654 	 * data can get inflight.
6655 	 */
6656 	if (rc_init_window(rack) < tp->snd_cwnd)
6657 		tp->snd_cwnd = rc_init_window(rack);
6658 }
6659 
6660 /*
6661  * Re-transmit timeout! If we drop the PCB we will return 1, otherwise
6662  * we will setup to retransmit the lowest seq number outstanding.
6663  */
6664 static int
6665 rack_timeout_rxt(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6666 {
6667 	int32_t rexmt;
6668 	struct inpcb *inp;
6669 	int32_t retval = 0;
6670 	bool isipv6;
6671 
6672 	inp = tp->t_inpcb;
6673 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6674 		return (1);
6675 	}
6676 	if (ctf_progress_timeout_check(tp, false)) {
6677 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
6678 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
6679 		tcp_set_inp_to_drop(inp, ETIMEDOUT);
6680 		return (1);
6681 	}
6682 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RXT;
6683 	rack->r_ctl.retran_during_recovery = 0;
6684 	rack->r_ctl.dsack_byte_cnt = 0;
6685 	if (IN_FASTRECOVERY(tp->t_flags))
6686 		tp->t_flags |= TF_WASFRECOVERY;
6687 	else
6688 		tp->t_flags &= ~TF_WASFRECOVERY;
6689 	if (IN_CONGRECOVERY(tp->t_flags))
6690 		tp->t_flags |= TF_WASCRECOVERY;
6691 	else
6692 		tp->t_flags &= ~TF_WASCRECOVERY;
6693 	if (TCPS_HAVEESTABLISHED(tp->t_state) &&
6694 	    (tp->snd_una == tp->snd_max)) {
6695 		/* Nothing outstanding .. nothing to do */
6696 		return (0);
6697 	}
6698 	/*
6699 	 * Rack can only run one timer  at a time, so we cannot
6700 	 * run a KEEPINIT (gating SYN sending) and a retransmit
6701 	 * timer for the SYN. So if we are in a front state and
6702 	 * have a KEEPINIT timer we need to check the first transmit
6703 	 * against now to see if we have exceeded the KEEPINIT time
6704 	 * (if one is set).
6705 	 */
6706 	if ((TCPS_HAVEESTABLISHED(tp->t_state) == 0) &&
6707 	    (TP_KEEPINIT(tp) != 0)) {
6708 		struct rack_sendmap *rsm;
6709 
6710 		rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6711 		if (rsm) {
6712 			/* Ok we have something outstanding to test keepinit with */
6713 			if ((TSTMP_GT(cts, (uint32_t)rsm->r_tim_lastsent[0])) &&
6714 			    ((cts - (uint32_t)rsm->r_tim_lastsent[0]) >= TICKS_2_USEC(TP_KEEPINIT(tp)))) {
6715 				/* We have exceeded the KEEPINIT time */
6716 				tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
6717 				goto drop_it;
6718 			}
6719 		}
6720 	}
6721 	/*
6722 	 * Retransmission timer went off.  Message has not been acked within
6723 	 * retransmit interval.  Back off to a longer retransmit interval
6724 	 * and retransmit one segment.
6725 	 */
6726 	rack_remxt_tmr(tp);
6727 	if ((rack->r_ctl.rc_resend == NULL) ||
6728 	    ((rack->r_ctl.rc_resend->r_flags & RACK_RWND_COLLAPSED) == 0)) {
6729 		/*
6730 		 * If the rwnd collapsed on
6731 		 * the one we are retransmitting
6732 		 * it does not count against the
6733 		 * rxt count.
6734 		 */
6735 		tp->t_rxtshift++;
6736 	}
6737 	if (tp->t_rxtshift > TCP_MAXRXTSHIFT) {
6738 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
6739 drop_it:
6740 		tp->t_rxtshift = TCP_MAXRXTSHIFT;
6741 		KMOD_TCPSTAT_INC(tcps_timeoutdrop);
6742 		retval = 1;
6743 		tcp_set_inp_to_drop(rack->rc_inp,
6744 		    (tp->t_softerror ? (uint16_t) tp->t_softerror : ETIMEDOUT));
6745 		goto out;
6746 	}
6747 	if (tp->t_state == TCPS_SYN_SENT) {
6748 		/*
6749 		 * If the SYN was retransmitted, indicate CWND to be limited
6750 		 * to 1 segment in cc_conn_init().
6751 		 */
6752 		tp->snd_cwnd = 1;
6753 	} else if (tp->t_rxtshift == 1) {
6754 		/*
6755 		 * first retransmit; record ssthresh and cwnd so they can be
6756 		 * recovered if this turns out to be a "bad" retransmit. A
6757 		 * retransmit is considered "bad" if an ACK for this segment
6758 		 * is received within RTT/2 interval; the assumption here is
6759 		 * that the ACK was already in flight.  See "On Estimating
6760 		 * End-to-End Network Path Properties" by Allman and Paxson
6761 		 * for more details.
6762 		 */
6763 		tp->snd_cwnd_prev = tp->snd_cwnd;
6764 		tp->snd_ssthresh_prev = tp->snd_ssthresh;
6765 		tp->snd_recover_prev = tp->snd_recover;
6766 		tp->t_badrxtwin = ticks + (USEC_2_TICKS(tp->t_srtt)/2);
6767 		tp->t_flags |= TF_PREVVALID;
6768 	} else if ((tp->t_flags & TF_RCVD_TSTMP) == 0)
6769 		tp->t_flags &= ~TF_PREVVALID;
6770 	KMOD_TCPSTAT_INC(tcps_rexmttimeo);
6771 	if ((tp->t_state == TCPS_SYN_SENT) ||
6772 	    (tp->t_state == TCPS_SYN_RECEIVED))
6773 		rexmt = RACK_INITIAL_RTO * tcp_backoff[tp->t_rxtshift];
6774 	else
6775 		rexmt = max(rack_rto_min, (tp->t_srtt + (tp->t_rttvar << 2))) * tcp_backoff[tp->t_rxtshift];
6776 
6777 	RACK_TCPT_RANGESET(tp->t_rxtcur, rexmt,
6778 	   max(rack_rto_min, rexmt), rack_rto_max, rack->r_ctl.timer_slop);
6779 	/*
6780 	 * We enter the path for PLMTUD if connection is established or, if
6781 	 * connection is FIN_WAIT_1 status, reason for the last is that if
6782 	 * amount of data we send is very small, we could send it in couple
6783 	 * of packets and process straight to FIN. In that case we won't
6784 	 * catch ESTABLISHED state.
6785 	 */
6786 #ifdef INET6
6787 	isipv6 = (tp->t_inpcb->inp_vflag & INP_IPV6) ? true : false;
6788 #else
6789 	isipv6 = false;
6790 #endif
6791 	if (((V_tcp_pmtud_blackhole_detect == 1) ||
6792 	    (V_tcp_pmtud_blackhole_detect == 2 && !isipv6) ||
6793 	    (V_tcp_pmtud_blackhole_detect == 3 && isipv6)) &&
6794 	    ((tp->t_state == TCPS_ESTABLISHED) ||
6795 	    (tp->t_state == TCPS_FIN_WAIT_1))) {
6796 		/*
6797 		 * Idea here is that at each stage of mtu probe (usually,
6798 		 * 1448 -> 1188 -> 524) should be given 2 chances to recover
6799 		 * before further clamping down. 'tp->t_rxtshift % 2 == 0'
6800 		 * should take care of that.
6801 		 */
6802 		if (((tp->t_flags2 & (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) ==
6803 		    (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) &&
6804 		    (tp->t_rxtshift >= 2 && tp->t_rxtshift < 6 &&
6805 		    tp->t_rxtshift % 2 == 0)) {
6806 			/*
6807 			 * Enter Path MTU Black-hole Detection mechanism: -
6808 			 * Disable Path MTU Discovery (IP "DF" bit). -
6809 			 * Reduce MTU to lower value than what we negotiated
6810 			 * with peer.
6811 			 */
6812 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) == 0) {
6813 				/* Record that we may have found a black hole. */
6814 				tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE;
6815 				/* Keep track of previous MSS. */
6816 				tp->t_pmtud_saved_maxseg = tp->t_maxseg;
6817 			}
6818 
6819 			/*
6820 			 * Reduce the MSS to blackhole value or to the
6821 			 * default in an attempt to retransmit.
6822 			 */
6823 #ifdef INET6
6824 			if (isipv6 &&
6825 			    tp->t_maxseg > V_tcp_v6pmtud_blackhole_mss) {
6826 				/* Use the sysctl tuneable blackhole MSS. */
6827 				tp->t_maxseg = V_tcp_v6pmtud_blackhole_mss;
6828 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
6829 			} else if (isipv6) {
6830 				/* Use the default MSS. */
6831 				tp->t_maxseg = V_tcp_v6mssdflt;
6832 				/*
6833 				 * Disable Path MTU Discovery when we switch
6834 				 * to minmss.
6835 				 */
6836 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
6837 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
6838 			}
6839 #endif
6840 #if defined(INET6) && defined(INET)
6841 			else
6842 #endif
6843 #ifdef INET
6844 			if (tp->t_maxseg > V_tcp_pmtud_blackhole_mss) {
6845 				/* Use the sysctl tuneable blackhole MSS. */
6846 				tp->t_maxseg = V_tcp_pmtud_blackhole_mss;
6847 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
6848 			} else {
6849 				/* Use the default MSS. */
6850 				tp->t_maxseg = V_tcp_mssdflt;
6851 				/*
6852 				 * Disable Path MTU Discovery when we switch
6853 				 * to minmss.
6854 				 */
6855 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
6856 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
6857 			}
6858 #endif
6859 		} else {
6860 			/*
6861 			 * If further retransmissions are still unsuccessful
6862 			 * with a lowered MTU, maybe this isn't a blackhole
6863 			 * and we restore the previous MSS and blackhole
6864 			 * detection flags. The limit '6' is determined by
6865 			 * giving each probe stage (1448, 1188, 524) 2
6866 			 * chances to recover.
6867 			 */
6868 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) &&
6869 			    (tp->t_rxtshift >= 6)) {
6870 				tp->t_flags2 |= TF2_PLPMTU_PMTUD;
6871 				tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE;
6872 				tp->t_maxseg = tp->t_pmtud_saved_maxseg;
6873 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_failed);
6874 			}
6875 		}
6876 	}
6877 	/*
6878 	 * Disable RFC1323 and SACK if we haven't got any response to
6879 	 * our third SYN to work-around some broken terminal servers
6880 	 * (most of which have hopefully been retired) that have bad VJ
6881 	 * header compression code which trashes TCP segments containing
6882 	 * unknown-to-them TCP options.
6883 	 */
6884 	if (tcp_rexmit_drop_options && (tp->t_state == TCPS_SYN_SENT) &&
6885 	    (tp->t_rxtshift == 3))
6886 		tp->t_flags &= ~(TF_REQ_SCALE|TF_REQ_TSTMP|TF_SACK_PERMIT);
6887 	/*
6888 	 * If we backed off this far, our srtt estimate is probably bogus.
6889 	 * Clobber it so we'll take the next rtt measurement as our srtt;
6890 	 * move the current srtt into rttvar to keep the current retransmit
6891 	 * times until then.
6892 	 */
6893 	if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
6894 #ifdef INET6
6895 		if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0)
6896 			in6_losing(tp->t_inpcb);
6897 		else
6898 #endif
6899 			in_losing(tp->t_inpcb);
6900 		tp->t_rttvar += tp->t_srtt;
6901 		tp->t_srtt = 0;
6902 	}
6903 	sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
6904 	tp->snd_recover = tp->snd_max;
6905 	tp->t_flags |= TF_ACKNOW;
6906 	tp->t_rtttime = 0;
6907 	rack_cong_signal(tp, CC_RTO, tp->snd_una);
6908 out:
6909 	return (retval);
6910 }
6911 
6912 static int
6913 rack_process_timers(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t hpts_calling)
6914 {
6915 	int32_t ret = 0;
6916 	int32_t timers = (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK);
6917 
6918 	if (timers == 0) {
6919 		return (0);
6920 	}
6921 	if (tp->t_state == TCPS_LISTEN) {
6922 		/* no timers on listen sockets */
6923 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)
6924 			return (0);
6925 		return (1);
6926 	}
6927 	if ((timers & PACE_TMR_RACK) &&
6928 	    rack->rc_on_min_to) {
6929 		/*
6930 		 * For the rack timer when we
6931 		 * are on a min-timeout (which means rrr_conf = 3)
6932 		 * we don't want to check the timer. It may
6933 		 * be going off for a pace and thats ok we
6934 		 * want to send the retransmit (if its ready).
6935 		 *
6936 		 * If its on a normal rack timer (non-min) then
6937 		 * we will check if its expired.
6938 		 */
6939 		goto skip_time_check;
6940 	}
6941 	if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
6942 		uint32_t left;
6943 
6944 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
6945 			ret = -1;
6946 			rack_log_to_processing(rack, cts, ret, 0);
6947 			return (0);
6948 		}
6949 		if (hpts_calling == 0) {
6950 			/*
6951 			 * A user send or queued mbuf (sack) has called us? We
6952 			 * return 0 and let the pacing guards
6953 			 * deal with it if they should or
6954 			 * should not cause a send.
6955 			 */
6956 			ret = -2;
6957 			rack_log_to_processing(rack, cts, ret, 0);
6958 			return (0);
6959 		}
6960 		/*
6961 		 * Ok our timer went off early and we are not paced false
6962 		 * alarm, go back to sleep.
6963 		 */
6964 		ret = -3;
6965 		left = rack->r_ctl.rc_timer_exp - cts;
6966 		tcp_hpts_insert(tp->t_inpcb, HPTS_MS_TO_SLOTS(left));
6967 		rack_log_to_processing(rack, cts, ret, left);
6968 		return (1);
6969 	}
6970 skip_time_check:
6971 	rack->rc_tmr_stopped = 0;
6972 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_MASK;
6973 	if (timers & PACE_TMR_DELACK) {
6974 		ret = rack_timeout_delack(tp, rack, cts);
6975 	} else if (timers & PACE_TMR_RACK) {
6976 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
6977 		rack->r_fast_output = 0;
6978 		ret = rack_timeout_rack(tp, rack, cts);
6979 	} else if (timers & PACE_TMR_TLP) {
6980 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
6981 		ret = rack_timeout_tlp(tp, rack, cts);
6982 	} else if (timers & PACE_TMR_RXT) {
6983 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
6984 		rack->r_fast_output = 0;
6985 		ret = rack_timeout_rxt(tp, rack, cts);
6986 	} else if (timers & PACE_TMR_PERSIT) {
6987 		ret = rack_timeout_persist(tp, rack, cts);
6988 	} else if (timers & PACE_TMR_KEEP) {
6989 		ret = rack_timeout_keepalive(tp, rack, cts);
6990 	}
6991 	rack_log_to_processing(rack, cts, ret, timers);
6992 	return (ret);
6993 }
6994 
6995 static void
6996 rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line)
6997 {
6998 	struct timeval tv;
6999 	uint32_t us_cts, flags_on_entry;
7000 	uint8_t hpts_removed = 0;
7001 
7002 	flags_on_entry = rack->r_ctl.rc_hpts_flags;
7003 	us_cts = tcp_get_usecs(&tv);
7004 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
7005 	    ((TSTMP_GEQ(us_cts, rack->r_ctl.rc_last_output_to)) ||
7006 	     ((tp->snd_max - tp->snd_una) == 0))) {
7007 		tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
7008 		hpts_removed = 1;
7009 		/* If we were not delayed cancel out the flag. */
7010 		if ((tp->snd_max - tp->snd_una) == 0)
7011 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
7012 		rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
7013 	}
7014 	if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
7015 		rack->rc_tmr_stopped = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
7016 		if (rack->rc_inp->inp_in_hpts &&
7017 		    ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)) {
7018 			/*
7019 			 * Canceling timer's when we have no output being
7020 			 * paced. We also must remove ourselves from the
7021 			 * hpts.
7022 			 */
7023 			tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
7024 			hpts_removed = 1;
7025 		}
7026 		rack->r_ctl.rc_hpts_flags &= ~(PACE_TMR_MASK);
7027 	}
7028 	if (hpts_removed == 0)
7029 		rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
7030 }
7031 
7032 static void
7033 rack_timer_stop(struct tcpcb *tp, uint32_t timer_type)
7034 {
7035 	return;
7036 }
7037 
7038 static int
7039 rack_stopall(struct tcpcb *tp)
7040 {
7041 	struct tcp_rack *rack;
7042 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7043 	rack->t_timers_stopped = 1;
7044 	return (0);
7045 }
7046 
7047 static void
7048 rack_timer_activate(struct tcpcb *tp, uint32_t timer_type, uint32_t delta)
7049 {
7050 	return;
7051 }
7052 
7053 static int
7054 rack_timer_active(struct tcpcb *tp, uint32_t timer_type)
7055 {
7056 	return (0);
7057 }
7058 
7059 static void
7060 rack_stop_all_timers(struct tcpcb *tp)
7061 {
7062 	struct tcp_rack *rack;
7063 
7064 	/*
7065 	 * Assure no timers are running.
7066 	 */
7067 	if (tcp_timer_active(tp, TT_PERSIST)) {
7068 		/* We enter in persists, set the flag appropriately */
7069 		rack = (struct tcp_rack *)tp->t_fb_ptr;
7070 		rack->rc_in_persist = 1;
7071 	}
7072 	tcp_timer_suspend(tp, TT_PERSIST);
7073 	tcp_timer_suspend(tp, TT_REXMT);
7074 	tcp_timer_suspend(tp, TT_KEEP);
7075 	tcp_timer_suspend(tp, TT_DELACK);
7076 }
7077 
7078 static void
7079 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
7080     struct rack_sendmap *rsm, uint64_t ts, uint16_t add_flag)
7081 {
7082 	int32_t idx;
7083 	uint16_t stripped_flags;
7084 
7085 	rsm->r_rtr_cnt++;
7086 	rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
7087 	rsm->r_dupack = 0;
7088 	if (rsm->r_rtr_cnt > RACK_NUM_OF_RETRANS) {
7089 		rsm->r_rtr_cnt = RACK_NUM_OF_RETRANS;
7090 		rsm->r_flags |= RACK_OVERMAX;
7091 	}
7092 	if ((rsm->r_rtr_cnt > 1) && ((rsm->r_flags & RACK_TLP) == 0)) {
7093 		rack->r_ctl.rc_holes_rxt += (rsm->r_end - rsm->r_start);
7094 		rsm->r_rtr_bytes += (rsm->r_end - rsm->r_start);
7095 	}
7096 	idx = rsm->r_rtr_cnt - 1;
7097 	rsm->r_tim_lastsent[idx] = ts;
7098 	stripped_flags = rsm->r_flags & ~(RACK_SENT_SP|RACK_SENT_FP);
7099 	if (rsm->r_flags & RACK_ACKED) {
7100 		/* Problably MTU discovery messing with us */
7101 		rsm->r_flags &= ~RACK_ACKED;
7102 		rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
7103 	}
7104 	if (rsm->r_in_tmap) {
7105 		TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7106 		rsm->r_in_tmap = 0;
7107 	}
7108 	TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7109 	rsm->r_in_tmap = 1;
7110 	if (rsm->r_flags & RACK_SACK_PASSED) {
7111 		/* We have retransmitted due to the SACK pass */
7112 		rsm->r_flags &= ~RACK_SACK_PASSED;
7113 		rsm->r_flags |= RACK_WAS_SACKPASS;
7114 	}
7115 }
7116 
7117 static uint32_t
7118 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
7119     struct rack_sendmap *rsm, uint64_t ts, int32_t *lenp, uint16_t add_flag)
7120 {
7121 	/*
7122 	 * We (re-)transmitted starting at rsm->r_start for some length
7123 	 * (possibly less than r_end.
7124 	 */
7125 	struct rack_sendmap *nrsm, *insret;
7126 	uint32_t c_end;
7127 	int32_t len;
7128 
7129 	len = *lenp;
7130 	c_end = rsm->r_start + len;
7131 	if (SEQ_GEQ(c_end, rsm->r_end)) {
7132 		/*
7133 		 * We retransmitted the whole piece or more than the whole
7134 		 * slopping into the next rsm.
7135 		 */
7136 		rack_update_rsm(tp, rack, rsm, ts, add_flag);
7137 		if (c_end == rsm->r_end) {
7138 			*lenp = 0;
7139 			return (0);
7140 		} else {
7141 			int32_t act_len;
7142 
7143 			/* Hangs over the end return whats left */
7144 			act_len = rsm->r_end - rsm->r_start;
7145 			*lenp = (len - act_len);
7146 			return (rsm->r_end);
7147 		}
7148 		/* We don't get out of this block. */
7149 	}
7150 	/*
7151 	 * Here we retransmitted less than the whole thing which means we
7152 	 * have to split this into what was transmitted and what was not.
7153 	 */
7154 	nrsm = rack_alloc_full_limit(rack);
7155 	if (nrsm == NULL) {
7156 		/*
7157 		 * We can't get memory, so lets not proceed.
7158 		 */
7159 		*lenp = 0;
7160 		return (0);
7161 	}
7162 	/*
7163 	 * So here we are going to take the original rsm and make it what we
7164 	 * retransmitted. nrsm will be the tail portion we did not
7165 	 * retransmit. For example say the chunk was 1, 11 (10 bytes). And
7166 	 * we retransmitted 5 bytes i.e. 1, 5. The original piece shrinks to
7167 	 * 1, 6 and the new piece will be 6, 11.
7168 	 */
7169 	rack_clone_rsm(rack, nrsm, rsm, c_end);
7170 	nrsm->r_dupack = 0;
7171 	rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
7172 	insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
7173 #ifdef INVARIANTS
7174 	if (insret != NULL) {
7175 		panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
7176 		      nrsm, insret, rack, rsm);
7177 	}
7178 #endif
7179 	if (rsm->r_in_tmap) {
7180 		TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7181 		nrsm->r_in_tmap = 1;
7182 	}
7183 	rsm->r_flags &= (~RACK_HAS_FIN);
7184 	rack_update_rsm(tp, rack, rsm, ts, add_flag);
7185 	/* Log a split of rsm into rsm and nrsm */
7186 	rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
7187 	*lenp = 0;
7188 	return (0);
7189 }
7190 
7191 static void
7192 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
7193 		uint32_t seq_out, uint8_t th_flags, int32_t err, uint64_t cts,
7194 		struct rack_sendmap *hintrsm, uint16_t add_flag, struct mbuf *s_mb, uint32_t s_moff)
7195 {
7196 	struct tcp_rack *rack;
7197 	struct rack_sendmap *rsm, *nrsm, *insret, fe;
7198 	register uint32_t snd_max, snd_una;
7199 
7200 	/*
7201 	 * Add to the RACK log of packets in flight or retransmitted. If
7202 	 * there is a TS option we will use the TS echoed, if not we will
7203 	 * grab a TS.
7204 	 *
7205 	 * Retransmissions will increment the count and move the ts to its
7206 	 * proper place. Note that if options do not include TS's then we
7207 	 * won't be able to effectively use the ACK for an RTT on a retran.
7208 	 *
7209 	 * Notes about r_start and r_end. Lets consider a send starting at
7210 	 * sequence 1 for 10 bytes. In such an example the r_start would be
7211 	 * 1 (starting sequence) but the r_end would be r_start+len i.e. 11.
7212 	 * This means that r_end is actually the first sequence for the next
7213 	 * slot (11).
7214 	 *
7215 	 */
7216 	/*
7217 	 * If err is set what do we do XXXrrs? should we not add the thing?
7218 	 * -- i.e. return if err != 0 or should we pretend we sent it? --
7219 	 * i.e. proceed with add ** do this for now.
7220 	 */
7221 	INP_WLOCK_ASSERT(tp->t_inpcb);
7222 	if (err)
7223 		/*
7224 		 * We don't log errors -- we could but snd_max does not
7225 		 * advance in this case either.
7226 		 */
7227 		return;
7228 
7229 	if (th_flags & TH_RST) {
7230 		/*
7231 		 * We don't log resets and we return immediately from
7232 		 * sending
7233 		 */
7234 		return;
7235 	}
7236 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7237 	snd_una = tp->snd_una;
7238 	snd_max = tp->snd_max;
7239 	if (th_flags & (TH_SYN | TH_FIN)) {
7240 		/*
7241 		 * The call to rack_log_output is made before bumping
7242 		 * snd_max. This means we can record one extra byte on a SYN
7243 		 * or FIN if seq_out is adding more on and a FIN is present
7244 		 * (and we are not resending).
7245 		 */
7246 		if ((th_flags & TH_SYN) && (seq_out == tp->iss))
7247 			len++;
7248 		if (th_flags & TH_FIN)
7249 			len++;
7250 		if (SEQ_LT(snd_max, tp->snd_nxt)) {
7251 			/*
7252 			 * The add/update as not been done for the FIN/SYN
7253 			 * yet.
7254 			 */
7255 			snd_max = tp->snd_nxt;
7256 		}
7257 	}
7258 	if (SEQ_LEQ((seq_out + len), snd_una)) {
7259 		/* Are sending an old segment to induce an ack (keep-alive)? */
7260 		return;
7261 	}
7262 	if (SEQ_LT(seq_out, snd_una)) {
7263 		/* huh? should we panic? */
7264 		uint32_t end;
7265 
7266 		end = seq_out + len;
7267 		seq_out = snd_una;
7268 		if (SEQ_GEQ(end, seq_out))
7269 			len = end - seq_out;
7270 		else
7271 			len = 0;
7272 	}
7273 	if (len == 0) {
7274 		/* We don't log zero window probes */
7275 		return;
7276 	}
7277 	rack->r_ctl.rc_time_last_sent = cts;
7278 	if (IN_FASTRECOVERY(tp->t_flags)) {
7279 		rack->r_ctl.rc_prr_out += len;
7280 	}
7281 	/* First question is it a retransmission or new? */
7282 	if (seq_out == snd_max) {
7283 		/* Its new */
7284 again:
7285 		rsm = rack_alloc(rack);
7286 		if (rsm == NULL) {
7287 			/*
7288 			 * Hmm out of memory and the tcb got destroyed while
7289 			 * we tried to wait.
7290 			 */
7291 			return;
7292 		}
7293 		if (th_flags & TH_FIN) {
7294 			rsm->r_flags = RACK_HAS_FIN|add_flag;
7295 		} else {
7296 			rsm->r_flags = add_flag;
7297 		}
7298 		rsm->r_tim_lastsent[0] = cts;
7299 		rsm->r_rtr_cnt = 1;
7300 		rsm->r_rtr_bytes = 0;
7301 		if (th_flags & TH_SYN) {
7302 			/* The data space is one beyond snd_una */
7303 			rsm->r_flags |= RACK_HAS_SYN;
7304 		}
7305 		rsm->r_start = seq_out;
7306 		rsm->r_end = rsm->r_start + len;
7307 		rsm->r_dupack = 0;
7308 		/*
7309 		 * save off the mbuf location that
7310 		 * sndmbuf_noadv returned (which is
7311 		 * where we started copying from)..
7312 		 */
7313 		rsm->m = s_mb;
7314 		rsm->soff = s_moff;
7315 		/* rsm->m will be NULL if RACK_HAS_SYN or RACK_HAS_FIN is set */
7316 		if (rsm->m) {
7317 			if (rsm->m->m_len <= rsm->soff) {
7318 				/*
7319 				 * XXXrrs Question, will this happen?
7320 				 *
7321 				 * If sbsndptr is set at the correct place
7322 				 * then s_moff should always be somewhere
7323 				 * within rsm->m. But if the sbsndptr was
7324 				 * off then that won't be true. If it occurs
7325 				 * we need to walkout to the correct location.
7326 				 */
7327 				struct mbuf *lm;
7328 
7329 				lm = rsm->m;
7330 				while (lm->m_len <= rsm->soff) {
7331 					rsm->soff -= lm->m_len;
7332 					lm = lm->m_next;
7333 					KASSERT(lm != NULL, ("%s rack:%p lm goes null orig_off:%u origmb:%p rsm->soff:%u",
7334 							     __func__, rack, s_moff, s_mb, rsm->soff));
7335 				}
7336 				rsm->m = lm;
7337 				counter_u64_add(rack_sbsndptr_wrong, 1);
7338 			} else
7339 				counter_u64_add(rack_sbsndptr_right, 1);
7340 			rsm->orig_m_len = rsm->m->m_len;
7341 		} else
7342 			rsm->orig_m_len = 0;
7343 		rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
7344 		/* Log a new rsm */
7345 		rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_NEW, 0, __LINE__);
7346 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
7347 #ifdef INVARIANTS
7348 		if (insret != NULL) {
7349 			panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
7350 			      nrsm, insret, rack, rsm);
7351 		}
7352 #endif
7353 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7354 		rsm->r_in_tmap = 1;
7355 		/*
7356 		 * Special case detection, is there just a single
7357 		 * packet outstanding when we are not in recovery?
7358 		 *
7359 		 * If this is true mark it so.
7360 		 */
7361 		if ((IN_FASTRECOVERY(tp->t_flags) == 0) &&
7362 		    (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) == ctf_fixed_maxseg(tp))) {
7363 			struct rack_sendmap *prsm;
7364 
7365 			prsm = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
7366 			if (prsm)
7367 				prsm->r_one_out_nr = 1;
7368 		}
7369 		return;
7370 	}
7371 	/*
7372 	 * If we reach here its a retransmission and we need to find it.
7373 	 */
7374 	memset(&fe, 0, sizeof(fe));
7375 more:
7376 	if (hintrsm && (hintrsm->r_start == seq_out)) {
7377 		rsm = hintrsm;
7378 		hintrsm = NULL;
7379 	} else {
7380 		/* No hints sorry */
7381 		rsm = NULL;
7382 	}
7383 	if ((rsm) && (rsm->r_start == seq_out)) {
7384 		seq_out = rack_update_entry(tp, rack, rsm, cts, &len, add_flag);
7385 		if (len == 0) {
7386 			return;
7387 		} else {
7388 			goto more;
7389 		}
7390 	}
7391 	/* Ok it was not the last pointer go through it the hard way. */
7392 refind:
7393 	fe.r_start = seq_out;
7394 	rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
7395 	if (rsm) {
7396 		if (rsm->r_start == seq_out) {
7397 			seq_out = rack_update_entry(tp, rack, rsm, cts, &len, add_flag);
7398 			if (len == 0) {
7399 				return;
7400 			} else {
7401 				goto refind;
7402 			}
7403 		}
7404 		if (SEQ_GEQ(seq_out, rsm->r_start) && SEQ_LT(seq_out, rsm->r_end)) {
7405 			/* Transmitted within this piece */
7406 			/*
7407 			 * Ok we must split off the front and then let the
7408 			 * update do the rest
7409 			 */
7410 			nrsm = rack_alloc_full_limit(rack);
7411 			if (nrsm == NULL) {
7412 				rack_update_rsm(tp, rack, rsm, cts, add_flag);
7413 				return;
7414 			}
7415 			/*
7416 			 * copy rsm to nrsm and then trim the front of rsm
7417 			 * to not include this part.
7418 			 */
7419 			rack_clone_rsm(rack, nrsm, rsm, seq_out);
7420 			insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
7421 			rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
7422 #ifdef INVARIANTS
7423 			if (insret != NULL) {
7424 				panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
7425 				      nrsm, insret, rack, rsm);
7426 			}
7427 #endif
7428 			if (rsm->r_in_tmap) {
7429 				TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7430 				nrsm->r_in_tmap = 1;
7431 			}
7432 			rsm->r_flags &= (~RACK_HAS_FIN);
7433 			seq_out = rack_update_entry(tp, rack, nrsm, cts, &len, add_flag);
7434 			if (len == 0) {
7435 				return;
7436 			} else if (len > 0)
7437 				goto refind;
7438 		}
7439 	}
7440 	/*
7441 	 * Hmm not found in map did they retransmit both old and on into the
7442 	 * new?
7443 	 */
7444 	if (seq_out == tp->snd_max) {
7445 		goto again;
7446 	} else if (SEQ_LT(seq_out, tp->snd_max)) {
7447 #ifdef INVARIANTS
7448 		printf("seq_out:%u len:%d snd_una:%u snd_max:%u -- but rsm not found?\n",
7449 		       seq_out, len, tp->snd_una, tp->snd_max);
7450 		printf("Starting Dump of all rack entries\n");
7451 		RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
7452 			printf("rsm:%p start:%u end:%u\n",
7453 			       rsm, rsm->r_start, rsm->r_end);
7454 		}
7455 		printf("Dump complete\n");
7456 		panic("seq_out not found rack:%p tp:%p",
7457 		      rack, tp);
7458 #endif
7459 	} else {
7460 #ifdef INVARIANTS
7461 		/*
7462 		 * Hmm beyond sndmax? (only if we are using the new rtt-pack
7463 		 * flag)
7464 		 */
7465 		panic("seq_out:%u(%d) is beyond snd_max:%u tp:%p",
7466 		      seq_out, len, tp->snd_max, tp);
7467 #endif
7468 	}
7469 }
7470 
7471 /*
7472  * Record one of the RTT updates from an ack into
7473  * our sample structure.
7474  */
7475 
7476 static void
7477 tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt, uint32_t len, uint32_t us_rtt,
7478 		    int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt)
7479 {
7480 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
7481 	    (rack->r_ctl.rack_rs.rs_rtt_lowest > rtt)) {
7482 		rack->r_ctl.rack_rs.rs_rtt_lowest = rtt;
7483 	}
7484 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
7485 	    (rack->r_ctl.rack_rs.rs_rtt_highest < rtt)) {
7486 		rack->r_ctl.rack_rs.rs_rtt_highest = rtt;
7487 	}
7488 	if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
7489 	    if (us_rtt < rack->r_ctl.rc_gp_lowrtt)
7490 		rack->r_ctl.rc_gp_lowrtt = us_rtt;
7491 	    if (rack->rc_tp->snd_wnd > rack->r_ctl.rc_gp_high_rwnd)
7492 		    rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
7493 	}
7494 	if ((confidence == 1) &&
7495 	    ((rsm == NULL) ||
7496 	     (rsm->r_just_ret) ||
7497 	     (rsm->r_one_out_nr &&
7498 	      len < (ctf_fixed_maxseg(rack->rc_tp) * 2)))) {
7499 		/*
7500 		 * If the rsm had a just return
7501 		 * hit it then we can't trust the
7502 		 * rtt measurement for buffer deterimination
7503 		 * Note that a confidence of 2, indicates
7504 		 * SACK'd which overrides the r_just_ret or
7505 		 * the r_one_out_nr. If it was a CUM-ACK and
7506 		 * we had only two outstanding, but get an
7507 		 * ack for only 1. Then that also lowers our
7508 		 * confidence.
7509 		 */
7510 		confidence = 0;
7511 	}
7512 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
7513 	    (rack->r_ctl.rack_rs.rs_us_rtt > us_rtt)) {
7514 		if (rack->r_ctl.rack_rs.confidence == 0) {
7515 			/*
7516 			 * We take anything with no current confidence
7517 			 * saved.
7518 			 */
7519 			rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
7520 			rack->r_ctl.rack_rs.confidence = confidence;
7521 			rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
7522 		} else if (confidence || rack->r_ctl.rack_rs.confidence) {
7523 			/*
7524 			 * Once we have a confident number,
7525 			 * we can update it with a smaller
7526 			 * value since this confident number
7527 			 * may include the DSACK time until
7528 			 * the next segment (the second one) arrived.
7529 			 */
7530 			rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
7531 			rack->r_ctl.rack_rs.confidence = confidence;
7532 			rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
7533 		}
7534 	}
7535 	rack_log_rtt_upd(rack->rc_tp, rack, us_rtt, len, rsm, confidence);
7536 	rack->r_ctl.rack_rs.rs_flags = RACK_RTT_VALID;
7537 	rack->r_ctl.rack_rs.rs_rtt_tot += rtt;
7538 	rack->r_ctl.rack_rs.rs_rtt_cnt++;
7539 }
7540 
7541 /*
7542  * Collect new round-trip time estimate
7543  * and update averages and current timeout.
7544  */
7545 static void
7546 tcp_rack_xmit_timer_commit(struct tcp_rack *rack, struct tcpcb *tp)
7547 {
7548 	int32_t delta;
7549 	uint32_t o_srtt, o_var;
7550 	int32_t hrtt_up = 0;
7551 	int32_t rtt;
7552 
7553 	if (rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY)
7554 		/* No valid sample */
7555 		return;
7556 	if (rack->r_ctl.rc_rate_sample_method == USE_RTT_LOW) {
7557 		/* We are to use the lowest RTT seen in a single ack */
7558 		rtt = rack->r_ctl.rack_rs.rs_rtt_lowest;
7559 	} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_HIGH) {
7560 		/* We are to use the highest RTT seen in a single ack */
7561 		rtt = rack->r_ctl.rack_rs.rs_rtt_highest;
7562 	} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_AVG) {
7563 		/* We are to use the average RTT seen in a single ack */
7564 		rtt = (int32_t)(rack->r_ctl.rack_rs.rs_rtt_tot /
7565 				(uint64_t)rack->r_ctl.rack_rs.rs_rtt_cnt);
7566 	} else {
7567 #ifdef INVARIANTS
7568 		panic("Unknown rtt variant %d", rack->r_ctl.rc_rate_sample_method);
7569 #endif
7570 		return;
7571 	}
7572 	if (rtt == 0)
7573 		rtt = 1;
7574 	if (rack->rc_gp_rtt_set == 0) {
7575 		/*
7576 		 * With no RTT we have to accept
7577 		 * even one we are not confident of.
7578 		 */
7579 		rack->r_ctl.rc_gp_srtt = rack->r_ctl.rack_rs.rs_us_rtt;
7580 		rack->rc_gp_rtt_set = 1;
7581 	} else if (rack->r_ctl.rack_rs.confidence) {
7582 		/* update the running gp srtt */
7583 		rack->r_ctl.rc_gp_srtt -= (rack->r_ctl.rc_gp_srtt/8);
7584 		rack->r_ctl.rc_gp_srtt += rack->r_ctl.rack_rs.rs_us_rtt / 8;
7585 	}
7586 	if (rack->r_ctl.rack_rs.confidence) {
7587 		/*
7588 		 * record the low and high for highly buffered path computation,
7589 		 * we only do this if we are confident (not a retransmission).
7590 		 */
7591 		if (rack->r_ctl.rc_highest_us_rtt < rack->r_ctl.rack_rs.rs_us_rtt) {
7592 			rack->r_ctl.rc_highest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
7593 			hrtt_up = 1;
7594 		}
7595 		if (rack->rc_highly_buffered == 0) {
7596 			/*
7597 			 * Currently once we declare a path has
7598 			 * highly buffered there is no going
7599 			 * back, which may be a problem...
7600 			 */
7601 			if ((rack->r_ctl.rc_highest_us_rtt / rack->r_ctl.rc_lowest_us_rtt) > rack_hbp_thresh) {
7602 				rack_log_rtt_shrinks(rack, rack->r_ctl.rack_rs.rs_us_rtt,
7603 						     rack->r_ctl.rc_highest_us_rtt,
7604 						     rack->r_ctl.rc_lowest_us_rtt,
7605 						     RACK_RTTS_SEEHBP);
7606 				rack->rc_highly_buffered = 1;
7607 			}
7608 		}
7609 	}
7610 	if ((rack->r_ctl.rack_rs.confidence) ||
7611 	    (rack->r_ctl.rack_rs.rs_us_rtrcnt == 1)) {
7612 		/*
7613 		 * If we are highly confident of it <or> it was
7614 		 * never retransmitted we accept it as the last us_rtt.
7615 		 */
7616 		rack->r_ctl.rc_last_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
7617 		/* The lowest rtt can be set if its was not retransmited */
7618 		if (rack->r_ctl.rc_lowest_us_rtt > rack->r_ctl.rack_rs.rs_us_rtt) {
7619 			rack->r_ctl.rc_lowest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
7620 			if (rack->r_ctl.rc_lowest_us_rtt == 0)
7621 				rack->r_ctl.rc_lowest_us_rtt = 1;
7622 		}
7623 	}
7624 	o_srtt = tp->t_srtt;
7625 	o_var = tp->t_rttvar;
7626 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7627 	if (tp->t_srtt != 0) {
7628 		/*
7629 		 * We keep a simple srtt in microseconds, like our rtt
7630 		 * measurement. We don't need to do any tricks with shifting
7631 		 * etc. Instead we just add in 1/8th of the new measurement
7632 		 * and subtract out 1/8 of the old srtt. We do the same with
7633 		 * the variance after finding the absolute value of the
7634 		 * difference between this sample and the current srtt.
7635 		 */
7636 		delta = tp->t_srtt - rtt;
7637 		/* Take off 1/8th of the current sRTT */
7638 		tp->t_srtt -= (tp->t_srtt >> 3);
7639 		/* Add in 1/8th of the new RTT just measured */
7640 		tp->t_srtt += (rtt >> 3);
7641 		if (tp->t_srtt <= 0)
7642 			tp->t_srtt = 1;
7643 		/* Now lets make the absolute value of the variance */
7644 		if (delta < 0)
7645 			delta = -delta;
7646 		/* Subtract out 1/8th */
7647 		tp->t_rttvar -= (tp->t_rttvar >> 3);
7648 		/* Add in 1/8th of the new variance we just saw */
7649 		tp->t_rttvar += (delta >> 3);
7650 		if (tp->t_rttvar <= 0)
7651 			tp->t_rttvar = 1;
7652 		if (tp->t_rttbest > tp->t_srtt + tp->t_rttvar)
7653 			tp->t_rttbest = tp->t_srtt + tp->t_rttvar;
7654 	} else {
7655 		/*
7656 		 * No rtt measurement yet - use the unsmoothed rtt. Set the
7657 		 * variance to half the rtt (so our first retransmit happens
7658 		 * at 3*rtt).
7659 		 */
7660 		tp->t_srtt = rtt;
7661 		tp->t_rttvar = rtt >> 1;
7662 		tp->t_rttbest = tp->t_srtt + tp->t_rttvar;
7663 	}
7664 	rack->rc_srtt_measure_made = 1;
7665 	KMOD_TCPSTAT_INC(tcps_rttupdated);
7666 	tp->t_rttupdated++;
7667 #ifdef STATS
7668 	if (rack_stats_gets_ms_rtt == 0) {
7669 		/* Send in the microsecond rtt used for rxt timeout purposes */
7670 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rtt));
7671 	} else if (rack_stats_gets_ms_rtt == 1) {
7672 		/* Send in the millisecond rtt used for rxt timeout purposes */
7673 		int32_t ms_rtt;
7674 
7675 		/* Round up */
7676 		ms_rtt = (rtt + HPTS_USEC_IN_MSEC - 1) / HPTS_USEC_IN_MSEC;
7677 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, ms_rtt));
7678 	} else if (rack_stats_gets_ms_rtt == 2) {
7679 		/* Send in the millisecond rtt has close to the path RTT as we can get  */
7680 		int32_t ms_rtt;
7681 
7682 		/* Round up */
7683 		ms_rtt = (rack->r_ctl.rack_rs.rs_us_rtt + HPTS_USEC_IN_MSEC - 1) / HPTS_USEC_IN_MSEC;
7684 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, ms_rtt));
7685 	}  else {
7686 		/* Send in the microsecond rtt has close to the path RTT as we can get  */
7687 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rack->r_ctl.rack_rs.rs_us_rtt));
7688 	}
7689 
7690 #endif
7691 	/*
7692 	 * the retransmit should happen at rtt + 4 * rttvar. Because of the
7693 	 * way we do the smoothing, srtt and rttvar will each average +1/2
7694 	 * tick of bias.  When we compute the retransmit timer, we want 1/2
7695 	 * tick of rounding and 1 extra tick because of +-1/2 tick
7696 	 * uncertainty in the firing of the timer.  The bias will give us
7697 	 * exactly the 1.5 tick we need.  But, because the bias is
7698 	 * statistical, we have to test that we don't drop below the minimum
7699 	 * feasible timer (which is 2 ticks).
7700 	 */
7701 	tp->t_rxtshift = 0;
7702 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
7703 		      max(rack_rto_min, rtt + 2), rack_rto_max, rack->r_ctl.timer_slop);
7704 	rack_log_rtt_sample(rack, rtt);
7705 	tp->t_softerror = 0;
7706 }
7707 
7708 
7709 static void
7710 rack_apply_updated_usrtt(struct tcp_rack *rack, uint32_t us_rtt, uint32_t us_cts)
7711 {
7712 	/*
7713 	 * Apply to filter the inbound us-rtt at us_cts.
7714 	 */
7715 	uint32_t old_rtt;
7716 
7717 	old_rtt = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
7718 	apply_filter_min_small(&rack->r_ctl.rc_gp_min_rtt,
7719 			       us_rtt, us_cts);
7720 	if (rack->r_ctl.last_pacing_time &&
7721 	    rack->rc_gp_dyn_mul &&
7722 	    (rack->r_ctl.last_pacing_time > us_rtt))
7723 		rack->pacing_longer_than_rtt = 1;
7724 	else
7725 		rack->pacing_longer_than_rtt = 0;
7726 	if (old_rtt > us_rtt) {
7727 		/* We just hit a new lower rtt time */
7728 		rack_log_rtt_shrinks(rack,  us_cts,  old_rtt,
7729 				     __LINE__, RACK_RTTS_NEWRTT);
7730 		/*
7731 		 * Only count it if its lower than what we saw within our
7732 		 * calculated range.
7733 		 */
7734 		if ((old_rtt - us_rtt) > rack_min_rtt_movement) {
7735 			if (rack_probertt_lower_within &&
7736 			    rack->rc_gp_dyn_mul &&
7737 			    (rack->use_fixed_rate == 0) &&
7738 			    (rack->rc_always_pace)) {
7739 				/*
7740 				 * We are seeing a new lower rtt very close
7741 				 * to the time that we would have entered probe-rtt.
7742 				 * This is probably due to the fact that a peer flow
7743 				 * has entered probe-rtt. Lets go in now too.
7744 				 */
7745 				uint32_t val;
7746 
7747 				val = rack_probertt_lower_within * rack_time_between_probertt;
7748 				val /= 100;
7749 				if ((rack->in_probe_rtt == 0)  &&
7750 				    ((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= (rack_time_between_probertt - val)))	{
7751 					rack_enter_probertt(rack, us_cts);
7752 				}
7753 			}
7754 			rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
7755 		}
7756 	}
7757 }
7758 
7759 static int
7760 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
7761     struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack)
7762 {
7763 	int32_t i, all;
7764 	uint32_t t, len_acked;
7765 
7766 	if ((rsm->r_flags & RACK_ACKED) ||
7767 	    (rsm->r_flags & RACK_WAS_ACKED))
7768 		/* Already done */
7769 		return (0);
7770 	if (rsm->r_no_rtt_allowed) {
7771 		/* Not allowed */
7772 		return (0);
7773 	}
7774 	if (ack_type == CUM_ACKED) {
7775 		if (SEQ_GT(th_ack, rsm->r_end)) {
7776 			len_acked = rsm->r_end - rsm->r_start;
7777 			all = 1;
7778 		} else {
7779 			len_acked = th_ack - rsm->r_start;
7780 			all = 0;
7781 		}
7782 	} else {
7783 		len_acked = rsm->r_end - rsm->r_start;
7784 		all = 0;
7785 	}
7786 	if (rsm->r_rtr_cnt == 1) {
7787 		uint32_t us_rtt;
7788 
7789 		t = cts - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
7790 		if ((int)t <= 0)
7791 			t = 1;
7792 		if (!tp->t_rttlow || tp->t_rttlow > t)
7793 			tp->t_rttlow = t;
7794 		if (!rack->r_ctl.rc_rack_min_rtt ||
7795 		    SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
7796 			rack->r_ctl.rc_rack_min_rtt = t;
7797 			if (rack->r_ctl.rc_rack_min_rtt == 0) {
7798 				rack->r_ctl.rc_rack_min_rtt = 1;
7799 			}
7800 		}
7801 		if (TSTMP_GT(tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time), rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]))
7802 			us_rtt = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
7803 		else
7804 			us_rtt = tcp_get_usecs(NULL) - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
7805 		if (us_rtt == 0)
7806 			us_rtt = 1;
7807 		rack_apply_updated_usrtt(rack, us_rtt, tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time));
7808 		if (ack_type == SACKED) {
7809 			rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)], cts, 1);
7810 			tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt, 2 , rsm, rsm->r_rtr_cnt);
7811 		} else {
7812 			/*
7813 			 * We need to setup what our confidence
7814 			 * is in this ack.
7815 			 *
7816 			 * If the rsm was app limited and it is
7817 			 * less than a mss in length (the end
7818 			 * of the send) then we have a gap. If we
7819 			 * were app limited but say we were sending
7820 			 * multiple MSS's then we are more confident
7821 			 * int it.
7822 			 *
7823 			 * When we are not app-limited then we see if
7824 			 * the rsm is being included in the current
7825 			 * measurement, we tell this by the app_limited_needs_set
7826 			 * flag.
7827 			 *
7828 			 * Note that being cwnd blocked is not applimited
7829 			 * as well as the pacing delay between packets which
7830 			 * are sending only 1 or 2 MSS's also will show up
7831 			 * in the RTT. We probably need to examine this algorithm
7832 			 * a bit more and enhance it to account for the delay
7833 			 * between rsm's. We could do that by saving off the
7834 			 * pacing delay of each rsm (in an rsm) and then
7835 			 * factoring that in somehow though for now I am
7836 			 * not sure how :)
7837 			 */
7838 			int calc_conf = 0;
7839 
7840 			if (rsm->r_flags & RACK_APP_LIMITED) {
7841 				if (all && (len_acked <= ctf_fixed_maxseg(tp)))
7842 					calc_conf = 0;
7843 				else
7844 					calc_conf = 1;
7845 			} else if (rack->app_limited_needs_set == 0) {
7846 				calc_conf = 1;
7847 			} else {
7848 				calc_conf = 0;
7849 			}
7850 			rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)], cts, 2);
7851 			tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt,
7852 					    calc_conf, rsm, rsm->r_rtr_cnt);
7853 		}
7854 		if ((rsm->r_flags & RACK_TLP) &&
7855 		    (!IN_FASTRECOVERY(tp->t_flags))) {
7856 			/* Segment was a TLP and our retrans matched */
7857 			if (rack->r_ctl.rc_tlp_cwnd_reduce) {
7858 				rack->r_ctl.rc_rsm_start = tp->snd_max;
7859 				rack->r_ctl.rc_cwnd_at = tp->snd_cwnd;
7860 				rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh;
7861 				rack_cong_signal(tp, CC_NDUPACK, tp->snd_una);
7862 			}
7863 		}
7864 		if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)])) {
7865 			/* New more recent rack_tmit_time */
7866 			rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
7867 			rack->rc_rack_rtt = t;
7868 		}
7869 		return (1);
7870 	}
7871 	/*
7872 	 * We clear the soft/rxtshift since we got an ack.
7873 	 * There is no assurance we will call the commit() function
7874 	 * so we need to clear these to avoid incorrect handling.
7875 	 */
7876 	tp->t_rxtshift = 0;
7877 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
7878 		      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
7879 	tp->t_softerror = 0;
7880 	if (to && (to->to_flags & TOF_TS) &&
7881 	    (ack_type == CUM_ACKED) &&
7882 	    (to->to_tsecr) &&
7883 	    ((rsm->r_flags & RACK_OVERMAX) == 0)) {
7884 		/*
7885 		 * Now which timestamp does it match? In this block the ACK
7886 		 * must be coming from a previous transmission.
7887 		 */
7888 		for (i = 0; i < rsm->r_rtr_cnt; i++) {
7889 			if (rack_ts_to_msec(rsm->r_tim_lastsent[i]) == to->to_tsecr) {
7890 				t = cts - (uint32_t)rsm->r_tim_lastsent[i];
7891 				if ((int)t <= 0)
7892 					t = 1;
7893 				if ((i + 1) < rsm->r_rtr_cnt) {
7894 					/*
7895 					 * The peer ack'd from our previous
7896 					 * transmission. We have a spurious
7897 					 * retransmission and thus we dont
7898 					 * want to update our rack_rtt.
7899 					 */
7900 					return (0);
7901 				}
7902 				if (!tp->t_rttlow || tp->t_rttlow > t)
7903 					tp->t_rttlow = t;
7904 				if (!rack->r_ctl.rc_rack_min_rtt || SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
7905 					rack->r_ctl.rc_rack_min_rtt = t;
7906 					if (rack->r_ctl.rc_rack_min_rtt == 0) {
7907 						rack->r_ctl.rc_rack_min_rtt = 1;
7908 					}
7909 				}
7910 				if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
7911 					   (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)])) {
7912 					/* New more recent rack_tmit_time */
7913 					rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
7914 					rack->rc_rack_rtt = t;
7915 				}
7916 				rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[i], cts, 3);
7917 				tcp_rack_xmit_timer(rack, t + 1, len_acked, t, 0, rsm,
7918 						    rsm->r_rtr_cnt);
7919 				return (1);
7920 			}
7921 		}
7922 		goto ts_not_found;
7923 	} else {
7924 		/*
7925 		 * Ok its a SACK block that we retransmitted. or a windows
7926 		 * machine without timestamps. We can tell nothing from the
7927 		 * time-stamp since its not there or the time the peer last
7928 		 * recieved a segment that moved forward its cum-ack point.
7929 		 */
7930 ts_not_found:
7931 		i = rsm->r_rtr_cnt - 1;
7932 		t = cts - (uint32_t)rsm->r_tim_lastsent[i];
7933 		if ((int)t <= 0)
7934 			t = 1;
7935 		if (rack->r_ctl.rc_rack_min_rtt && SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
7936 			/*
7937 			 * We retransmitted and the ack came back in less
7938 			 * than the smallest rtt we have observed. We most
7939 			 * likely did an improper retransmit as outlined in
7940 			 * 6.2 Step 2 point 2 in the rack-draft so we
7941 			 * don't want to update our rack_rtt. We in
7942 			 * theory (in future) might want to think about reverting our
7943 			 * cwnd state but we won't for now.
7944 			 */
7945 			return (0);
7946 		} else if (rack->r_ctl.rc_rack_min_rtt) {
7947 			/*
7948 			 * We retransmitted it and the retransmit did the
7949 			 * job.
7950 			 */
7951 			if (!rack->r_ctl.rc_rack_min_rtt ||
7952 			    SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
7953 				rack->r_ctl.rc_rack_min_rtt = t;
7954 				if (rack->r_ctl.rc_rack_min_rtt == 0) {
7955 					rack->r_ctl.rc_rack_min_rtt = 1;
7956 				}
7957 			}
7958 			if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, (uint32_t)rsm->r_tim_lastsent[i])) {
7959 				/* New more recent rack_tmit_time */
7960 				rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[i];
7961 				rack->rc_rack_rtt = t;
7962 			}
7963 			return (1);
7964 		}
7965 	}
7966 	return (0);
7967 }
7968 
7969 /*
7970  * Mark the SACK_PASSED flag on all entries prior to rsm send wise.
7971  */
7972 static void
7973 rack_log_sack_passed(struct tcpcb *tp,
7974     struct tcp_rack *rack, struct rack_sendmap *rsm)
7975 {
7976 	struct rack_sendmap *nrsm;
7977 
7978 	nrsm = rsm;
7979 	TAILQ_FOREACH_REVERSE_FROM(nrsm, &rack->r_ctl.rc_tmap,
7980 	    rack_head, r_tnext) {
7981 		if (nrsm == rsm) {
7982 			/* Skip orginal segment he is acked */
7983 			continue;
7984 		}
7985 		if (nrsm->r_flags & RACK_ACKED) {
7986 			/*
7987 			 * Skip ack'd segments, though we
7988 			 * should not see these, since tmap
7989 			 * should not have ack'd segments.
7990 			 */
7991 			continue;
7992 		}
7993 		if (nrsm->r_flags & RACK_SACK_PASSED) {
7994 			/*
7995 			 * We found one that is already marked
7996 			 * passed, we have been here before and
7997 			 * so all others below this are marked.
7998 			 */
7999 			break;
8000 		}
8001 		nrsm->r_flags |= RACK_SACK_PASSED;
8002 		nrsm->r_flags &= ~RACK_WAS_SACKPASS;
8003 	}
8004 }
8005 
8006 static void
8007 rack_need_set_test(struct tcpcb *tp,
8008 		   struct tcp_rack *rack,
8009 		   struct rack_sendmap *rsm,
8010 		   tcp_seq th_ack,
8011 		   int line,
8012 		   int use_which)
8013 {
8014 
8015 	if ((tp->t_flags & TF_GPUTINPROG) &&
8016 	    SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
8017 		/*
8018 		 * We were app limited, and this ack
8019 		 * butts up or goes beyond the point where we want
8020 		 * to start our next measurement. We need
8021 		 * to record the new gput_ts as here and
8022 		 * possibly update the start sequence.
8023 		 */
8024 		uint32_t seq, ts;
8025 
8026 		if (rsm->r_rtr_cnt > 1) {
8027 			/*
8028 			 * This is a retransmit, can we
8029 			 * really make any assessment at this
8030 			 * point?  We are not really sure of
8031 			 * the timestamp, is it this or the
8032 			 * previous transmission?
8033 			 *
8034 			 * Lets wait for something better that
8035 			 * is not retransmitted.
8036 			 */
8037 			return;
8038 		}
8039 		seq = tp->gput_seq;
8040 		ts = tp->gput_ts;
8041 		rack->app_limited_needs_set = 0;
8042 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
8043 		/* Do we start at a new end? */
8044 		if ((use_which == RACK_USE_BEG) &&
8045 		    SEQ_GEQ(rsm->r_start, tp->gput_seq)) {
8046 			/*
8047 			 * When we get an ACK that just eats
8048 			 * up some of the rsm, we set RACK_USE_BEG
8049 			 * since whats at r_start (i.e. th_ack)
8050 			 * is left unacked and thats where the
8051 			 * measurement not starts.
8052 			 */
8053 			tp->gput_seq = rsm->r_start;
8054 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8055 		}
8056 		if ((use_which == RACK_USE_END) &&
8057 		    SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
8058 			    /*
8059 			     * We use the end when the cumack
8060 			     * is moving forward and completely
8061 			     * deleting the rsm passed so basically
8062 			     * r_end holds th_ack.
8063 			     *
8064 			     * For SACK's we also want to use the end
8065 			     * since this piece just got sacked and
8066 			     * we want to target anything after that
8067 			     * in our measurement.
8068 			     */
8069 			    tp->gput_seq = rsm->r_end;
8070 			    rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8071 		}
8072 		if (use_which == RACK_USE_END_OR_THACK) {
8073 			/*
8074 			 * special case for ack moving forward,
8075 			 * not a sack, we need to move all the
8076 			 * way up to where this ack cum-ack moves
8077 			 * to.
8078 			 */
8079 			if (SEQ_GT(th_ack, rsm->r_end))
8080 				tp->gput_seq = th_ack;
8081 			else
8082 				tp->gput_seq = rsm->r_end;
8083 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8084 		}
8085 		if (SEQ_GT(tp->gput_seq, tp->gput_ack)) {
8086 			/*
8087 			 * We moved beyond this guy's range, re-calculate
8088 			 * the new end point.
8089 			 */
8090 			if (rack->rc_gp_filled == 0) {
8091 				tp->gput_ack = tp->gput_seq + max(rc_init_window(rack), (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
8092 			} else {
8093 				tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
8094 			}
8095 		}
8096 		/*
8097 		 * We are moving the goal post, we may be able to clear the
8098 		 * measure_saw_probe_rtt flag.
8099 		 */
8100 		if ((rack->in_probe_rtt == 0) &&
8101 		    (rack->measure_saw_probe_rtt) &&
8102 		    (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
8103 			rack->measure_saw_probe_rtt = 0;
8104 		rack_log_pacing_delay_calc(rack, ts, tp->gput_ts,
8105 					   seq, tp->gput_seq, 0, 5, line, NULL);
8106 		if (rack->rc_gp_filled &&
8107 		    ((tp->gput_ack - tp->gput_seq) <
8108 		     max(rc_init_window(rack), (MIN_GP_WIN *
8109 						ctf_fixed_maxseg(tp))))) {
8110 			uint32_t ideal_amount;
8111 
8112 			ideal_amount = rack_get_measure_window(tp, rack);
8113 			if (ideal_amount > sbavail(&tp->t_inpcb->inp_socket->so_snd)) {
8114 				/*
8115 				 * There is no sense of continuing this measurement
8116 				 * because its too small to gain us anything we
8117 				 * trust. Skip it and that way we can start a new
8118 				 * measurement quicker.
8119 				 */
8120 				tp->t_flags &= ~TF_GPUTINPROG;
8121 				rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
8122 							   0, 0, 0, 6, __LINE__, NULL);
8123 			} else {
8124 				/*
8125 				 * Reset the window further out.
8126 				 */
8127 				tp->gput_ack = tp->gput_seq + ideal_amount;
8128 			}
8129 		}
8130 	}
8131 }
8132 
8133 static uint32_t
8134 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack, struct sackblk *sack,
8135 		   struct tcpopt *to, struct rack_sendmap **prsm, uint32_t cts, int *moved_two)
8136 {
8137 	uint32_t start, end, changed = 0;
8138 	struct rack_sendmap stack_map;
8139 	struct rack_sendmap *rsm, *nrsm, fe, *insret, *prev, *next;
8140 	int32_t used_ref = 1;
8141 	int moved = 0;
8142 
8143 	start = sack->start;
8144 	end = sack->end;
8145 	rsm = *prsm;
8146 	memset(&fe, 0, sizeof(fe));
8147 do_rest_ofb:
8148 	if ((rsm == NULL) ||
8149 	    (SEQ_LT(end, rsm->r_start)) ||
8150 	    (SEQ_GEQ(start, rsm->r_end)) ||
8151 	    (SEQ_LT(start, rsm->r_start))) {
8152 		/*
8153 		 * We are not in the right spot,
8154 		 * find the correct spot in the tree.
8155 		 */
8156 		used_ref = 0;
8157 		fe.r_start = start;
8158 		rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
8159 		moved++;
8160 	}
8161 	if (rsm == NULL) {
8162 		/* TSNH */
8163 		goto out;
8164 	}
8165 	/* Ok we have an ACK for some piece of this rsm */
8166 	if (rsm->r_start != start) {
8167 		if ((rsm->r_flags & RACK_ACKED) == 0) {
8168 			/**
8169 			 * Need to split this in two pieces the before and after,
8170 			 * the before remains in the map, the after must be
8171 			 * added. In other words we have:
8172 			 * rsm        |--------------|
8173 			 * sackblk        |------->
8174 			 * rsm will become
8175 			 *     rsm    |---|
8176 			 * and nrsm will be  the sacked piece
8177 			 *     nrsm       |----------|
8178 			 *
8179 			 * But before we start down that path lets
8180 			 * see if the sack spans over on top of
8181 			 * the next guy and it is already sacked.
8182 			 */
8183 			next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8184 			if (next && (next->r_flags & RACK_ACKED) &&
8185 			    SEQ_GEQ(end, next->r_start)) {
8186 				/**
8187 				 * So the next one is already acked, and
8188 				 * we can thus by hookery use our stack_map
8189 				 * to reflect the piece being sacked and
8190 				 * then adjust the two tree entries moving
8191 				 * the start and ends around. So we start like:
8192 				 *  rsm     |------------|             (not-acked)
8193 				 *  next                 |-----------| (acked)
8194 				 *  sackblk        |-------->
8195 				 *  We want to end like so:
8196 				 *  rsm     |------|                   (not-acked)
8197 				 *  next           |-----------------| (acked)
8198 				 *  nrsm           |-----|
8199 				 * Where nrsm is a temporary stack piece we
8200 				 * use to update all the gizmos.
8201 				 */
8202 				/* Copy up our fudge block */
8203 				nrsm = &stack_map;
8204 				memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
8205 				/* Now adjust our tree blocks */
8206 				rsm->r_end = start;
8207 				next->r_start = start;
8208 				/* Now we must adjust back where next->m is */
8209 				rack_setup_offset_for_rsm(rsm, next);
8210 
8211 				/* We don't need to adjust rsm, it did not change */
8212 				/* Clear out the dup ack count of the remainder */
8213 				rsm->r_dupack = 0;
8214 				rsm->r_just_ret = 0;
8215 				rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
8216 				/* Now lets make sure our fudge block is right */
8217 				nrsm->r_start = start;
8218 				/* Now lets update all the stats and such */
8219 				rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
8220 				if (rack->app_limited_needs_set)
8221 					rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
8222 				changed += (nrsm->r_end - nrsm->r_start);
8223 				rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
8224 				if (nrsm->r_flags & RACK_SACK_PASSED) {
8225 					counter_u64_add(rack_reorder_seen, 1);
8226 					rack->r_ctl.rc_reorder_ts = cts;
8227 				}
8228 				/*
8229 				 * Now we want to go up from rsm (the
8230 				 * one left un-acked) to the next one
8231 				 * in the tmap. We do this so when
8232 				 * we walk backwards we include marking
8233 				 * sack-passed on rsm (The one passed in
8234 				 * is skipped since it is generally called
8235 				 * on something sacked before removing it
8236 				 * from the tmap).
8237 				 */
8238 				if (rsm->r_in_tmap) {
8239 					nrsm = TAILQ_NEXT(rsm, r_tnext);
8240 					/*
8241 					 * Now that we have the next
8242 					 * one walk backwards from there.
8243 					 */
8244 					if (nrsm && nrsm->r_in_tmap)
8245 						rack_log_sack_passed(tp, rack, nrsm);
8246 				}
8247 				/* Now are we done? */
8248 				if (SEQ_LT(end, next->r_end) ||
8249 				    (end == next->r_end)) {
8250 					/* Done with block */
8251 					goto out;
8252 				}
8253 				rack_log_map_chg(tp, rack, &stack_map, rsm, next, MAP_SACK_M1, end, __LINE__);
8254 				counter_u64_add(rack_sack_used_next_merge, 1);
8255 				/* Postion for the next block */
8256 				start = next->r_end;
8257 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, next);
8258 				if (rsm == NULL)
8259 					goto out;
8260 			} else {
8261 				/**
8262 				 * We can't use any hookery here, so we
8263 				 * need to split the map. We enter like
8264 				 * so:
8265 				 *  rsm      |--------|
8266 				 *  sackblk       |----->
8267 				 * We will add the new block nrsm and
8268 				 * that will be the new portion, and then
8269 				 * fall through after reseting rsm. So we
8270 				 * split and look like this:
8271 				 *  rsm      |----|
8272 				 *  sackblk       |----->
8273 				 *  nrsm          |---|
8274 				 * We then fall through reseting
8275 				 * rsm to nrsm, so the next block
8276 				 * picks it up.
8277 				 */
8278 				nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
8279 				if (nrsm == NULL) {
8280 					/*
8281 					 * failed XXXrrs what can we do but loose the sack
8282 					 * info?
8283 					 */
8284 					goto out;
8285 				}
8286 				counter_u64_add(rack_sack_splits, 1);
8287 				rack_clone_rsm(rack, nrsm, rsm, start);
8288 				rsm->r_just_ret = 0;
8289 				insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
8290 #ifdef INVARIANTS
8291 				if (insret != NULL) {
8292 					panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
8293 					      nrsm, insret, rack, rsm);
8294 				}
8295 #endif
8296 				if (rsm->r_in_tmap) {
8297 					TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8298 					nrsm->r_in_tmap = 1;
8299 				}
8300 				rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SACK_M2, end, __LINE__);
8301 				rsm->r_flags &= (~RACK_HAS_FIN);
8302 				/* Position us to point to the new nrsm that starts the sack blk */
8303 				rsm = nrsm;
8304 			}
8305 		} else {
8306 			/* Already sacked this piece */
8307 			counter_u64_add(rack_sack_skipped_acked, 1);
8308 			moved++;
8309 			if (end == rsm->r_end) {
8310 				/* Done with block */
8311 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8312 				goto out;
8313 			} else if (SEQ_LT(end, rsm->r_end)) {
8314 				/* A partial sack to a already sacked block */
8315 				moved++;
8316 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8317 				goto out;
8318 			} else {
8319 				/*
8320 				 * The end goes beyond this guy
8321 				 * repostion the start to the
8322 				 * next block.
8323 				 */
8324 				start = rsm->r_end;
8325 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8326 				if (rsm == NULL)
8327 					goto out;
8328 			}
8329 		}
8330 	}
8331 	if (SEQ_GEQ(end, rsm->r_end)) {
8332 		/**
8333 		 * The end of this block is either beyond this guy or right
8334 		 * at this guy. I.e.:
8335 		 *  rsm ---                 |-----|
8336 		 *  end                     |-----|
8337 		 *  <or>
8338 		 *  end                     |---------|
8339 		 */
8340 		if ((rsm->r_flags & RACK_ACKED) == 0) {
8341 			rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
8342 			changed += (rsm->r_end - rsm->r_start);
8343 			rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
8344 			if (rsm->r_in_tmap) /* should be true */
8345 				rack_log_sack_passed(tp, rack, rsm);
8346 			/* Is Reordering occuring? */
8347 			if (rsm->r_flags & RACK_SACK_PASSED) {
8348 				rsm->r_flags &= ~RACK_SACK_PASSED;
8349 				counter_u64_add(rack_reorder_seen, 1);
8350 				rack->r_ctl.rc_reorder_ts = cts;
8351 			}
8352 			if (rack->app_limited_needs_set)
8353 				rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
8354 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
8355 			rsm->r_flags |= RACK_ACKED;
8356 			rsm->r_flags &= ~RACK_TLP;
8357 			if (rsm->r_in_tmap) {
8358 				TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8359 				rsm->r_in_tmap = 0;
8360 			}
8361 			rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_SACK_M3, end, __LINE__);
8362 		} else {
8363 			counter_u64_add(rack_sack_skipped_acked, 1);
8364 			moved++;
8365 		}
8366 		if (end == rsm->r_end) {
8367 			/* This block only - done, setup for next */
8368 			goto out;
8369 		}
8370 		/*
8371 		 * There is more not coverend by this rsm move on
8372 		 * to the next block in the RB tree.
8373 		 */
8374 		nrsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8375 		start = rsm->r_end;
8376 		rsm = nrsm;
8377 		if (rsm == NULL)
8378 			goto out;
8379 		goto do_rest_ofb;
8380 	}
8381 	/**
8382 	 * The end of this sack block is smaller than
8383 	 * our rsm i.e.:
8384 	 *  rsm ---                 |-----|
8385 	 *  end                     |--|
8386 	 */
8387 	if ((rsm->r_flags & RACK_ACKED) == 0) {
8388 		prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8389 		if (prev && (prev->r_flags & RACK_ACKED)) {
8390 			/**
8391 			 * Goal, we want the right remainder of rsm to shrink
8392 			 * in place and span from (rsm->r_start = end) to rsm->r_end.
8393 			 * We want to expand prev to go all the way
8394 			 * to prev->r_end <- end.
8395 			 * so in the tree we have before:
8396 			 *   prev     |--------|         (acked)
8397 			 *   rsm               |-------| (non-acked)
8398 			 *   sackblk           |-|
8399 			 * We churn it so we end up with
8400 			 *   prev     |----------|       (acked)
8401 			 *   rsm                 |-----| (non-acked)
8402 			 *   nrsm              |-| (temporary)
8403 			 */
8404 			nrsm = &stack_map;
8405 			memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
8406 			prev->r_end = end;
8407 			rsm->r_start = end;
8408 			/* Now adjust nrsm (stack copy) to be
8409 			 * the one that is the small
8410 			 * piece that was "sacked".
8411 			 */
8412 			nrsm->r_end = end;
8413 			rsm->r_dupack = 0;
8414 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
8415 			/*
8416 			 * Now that the rsm has had its start moved forward
8417 			 * lets go ahead and get its new place in the world.
8418 			 */
8419 			rack_setup_offset_for_rsm(prev, rsm);
8420 			/*
8421 			 * Now nrsm is our new little piece
8422 			 * that is acked (which was merged
8423 			 * to prev). Update the rtt and changed
8424 			 * based on that. Also check for reordering.
8425 			 */
8426 			rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
8427 			if (rack->app_limited_needs_set)
8428 				rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
8429 			changed += (nrsm->r_end - nrsm->r_start);
8430 			rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
8431 			if (nrsm->r_flags & RACK_SACK_PASSED) {
8432 				counter_u64_add(rack_reorder_seen, 1);
8433 				rack->r_ctl.rc_reorder_ts = cts;
8434 			}
8435 			rack_log_map_chg(tp, rack, prev, &stack_map, rsm, MAP_SACK_M4, end, __LINE__);
8436 			rsm = prev;
8437 			counter_u64_add(rack_sack_used_prev_merge, 1);
8438 		} else {
8439 			/**
8440 			 * This is the case where our previous
8441 			 * block is not acked either, so we must
8442 			 * split the block in two.
8443 			 */
8444 			nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
8445 			if (nrsm == NULL) {
8446 				/* failed rrs what can we do but loose the sack info? */
8447 				goto out;
8448 			}
8449 			/**
8450 			 * In this case nrsm becomes
8451 			 * nrsm->r_start = end;
8452 			 * nrsm->r_end = rsm->r_end;
8453 			 * which is un-acked.
8454 			 * <and>
8455 			 * rsm->r_end = nrsm->r_start;
8456 			 * i.e. the remaining un-acked
8457 			 * piece is left on the left
8458 			 * hand side.
8459 			 *
8460 			 * So we start like this
8461 			 * rsm      |----------| (not acked)
8462 			 * sackblk  |---|
8463 			 * build it so we have
8464 			 * rsm      |---|         (acked)
8465 			 * nrsm         |------|  (not acked)
8466 			 */
8467 			counter_u64_add(rack_sack_splits, 1);
8468 			rack_clone_rsm(rack, nrsm, rsm, end);
8469 			rsm->r_flags &= (~RACK_HAS_FIN);
8470 			rsm->r_just_ret = 0;
8471 			insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
8472 #ifdef INVARIANTS
8473 			if (insret != NULL) {
8474 				panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
8475 				      nrsm, insret, rack, rsm);
8476 			}
8477 #endif
8478 			if (rsm->r_in_tmap) {
8479 				TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8480 				nrsm->r_in_tmap = 1;
8481 			}
8482 			nrsm->r_dupack = 0;
8483 			rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
8484 			rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
8485 			changed += (rsm->r_end - rsm->r_start);
8486 			rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
8487 			if (rsm->r_in_tmap) /* should be true */
8488 				rack_log_sack_passed(tp, rack, rsm);
8489 			/* Is Reordering occuring? */
8490 			if (rsm->r_flags & RACK_SACK_PASSED) {
8491 				rsm->r_flags &= ~RACK_SACK_PASSED;
8492 				counter_u64_add(rack_reorder_seen, 1);
8493 				rack->r_ctl.rc_reorder_ts = cts;
8494 			}
8495 			if (rack->app_limited_needs_set)
8496 				rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
8497 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
8498 			rsm->r_flags |= RACK_ACKED;
8499 			rsm->r_flags &= ~RACK_TLP;
8500 			rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SACK_M5, end, __LINE__);
8501 			if (rsm->r_in_tmap) {
8502 				TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8503 				rsm->r_in_tmap = 0;
8504 			}
8505 		}
8506 	} else if (start != end){
8507 		/*
8508 		 * The block was already acked.
8509 		 */
8510 		counter_u64_add(rack_sack_skipped_acked, 1);
8511 		moved++;
8512 	}
8513 out:
8514 	if (rsm && (rsm->r_flags & RACK_ACKED)) {
8515 		/*
8516 		 * Now can we merge where we worked
8517 		 * with either the previous or
8518 		 * next block?
8519 		 */
8520 		next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8521 		while (next) {
8522 		    if (next->r_flags & RACK_ACKED) {
8523 			/* yep this and next can be merged */
8524 			rsm = rack_merge_rsm(rack, rsm, next);
8525 			next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8526 		    } else
8527 			    break;
8528 		}
8529 		/* Now what about the previous? */
8530 		prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8531 		while (prev) {
8532 		    if (prev->r_flags & RACK_ACKED) {
8533 			/* yep the previous and this can be merged */
8534 			rsm = rack_merge_rsm(rack, prev, rsm);
8535 			prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8536 		    } else
8537 			    break;
8538 		}
8539 	}
8540 	if (used_ref == 0) {
8541 		counter_u64_add(rack_sack_proc_all, 1);
8542 	} else {
8543 		counter_u64_add(rack_sack_proc_short, 1);
8544 	}
8545 	/* Save off the next one for quick reference. */
8546 	if (rsm)
8547 		nrsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8548 	else
8549 		nrsm = NULL;
8550 	*prsm = rack->r_ctl.rc_sacklast = nrsm;
8551 	/* Pass back the moved. */
8552 	*moved_two = moved;
8553 	return (changed);
8554 }
8555 
8556 static void inline
8557 rack_peer_reneges(struct tcp_rack *rack, struct rack_sendmap *rsm, tcp_seq th_ack)
8558 {
8559 	struct rack_sendmap *tmap;
8560 
8561 	tmap = NULL;
8562 	while (rsm && (rsm->r_flags & RACK_ACKED)) {
8563 		/* Its no longer sacked, mark it so */
8564 		rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
8565 #ifdef INVARIANTS
8566 		if (rsm->r_in_tmap) {
8567 			panic("rack:%p rsm:%p flags:0x%x in tmap?",
8568 			      rack, rsm, rsm->r_flags);
8569 		}
8570 #endif
8571 		rsm->r_flags &= ~(RACK_ACKED|RACK_SACK_PASSED|RACK_WAS_SACKPASS);
8572 		/* Rebuild it into our tmap */
8573 		if (tmap == NULL) {
8574 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8575 			tmap = rsm;
8576 		} else {
8577 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, tmap, rsm, r_tnext);
8578 			tmap = rsm;
8579 		}
8580 		tmap->r_in_tmap = 1;
8581 		rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8582 	}
8583 	/*
8584 	 * Now lets possibly clear the sack filter so we start
8585 	 * recognizing sacks that cover this area.
8586 	 */
8587 	sack_filter_clear(&rack->r_ctl.rack_sf, th_ack);
8588 
8589 }
8590 
8591 static void
8592 rack_do_decay(struct tcp_rack *rack)
8593 {
8594 	struct timeval res;
8595 
8596 #define	timersub(tvp, uvp, vvp)						\
8597 	do {								\
8598 		(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;		\
8599 		(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;	\
8600 		if ((vvp)->tv_usec < 0) {				\
8601 			(vvp)->tv_sec--;				\
8602 			(vvp)->tv_usec += 1000000;			\
8603 		}							\
8604 	} while (0)
8605 
8606 	timersub(&rack->r_ctl.act_rcv_time, &rack->r_ctl.rc_last_time_decay, &res);
8607 #undef timersub
8608 
8609 	rack->r_ctl.input_pkt++;
8610 	if ((rack->rc_in_persist) ||
8611 	    (res.tv_sec >= 1) ||
8612 	    (rack->rc_tp->snd_max == rack->rc_tp->snd_una)) {
8613 		/*
8614 		 * Check for decay of non-SAD,
8615 		 * we want all SAD detection metrics to
8616 		 * decay 1/4 per second (or more) passed.
8617 		 */
8618 		uint32_t pkt_delta;
8619 
8620 		pkt_delta = rack->r_ctl.input_pkt - rack->r_ctl.saved_input_pkt;
8621 		/* Update our saved tracking values */
8622 		rack->r_ctl.saved_input_pkt = rack->r_ctl.input_pkt;
8623 		rack->r_ctl.rc_last_time_decay = rack->r_ctl.act_rcv_time;
8624 		/* Now do we escape without decay? */
8625 #ifdef NETFLIX_EXP_DETECTION
8626 		if (rack->rc_in_persist ||
8627 		    (rack->rc_tp->snd_max == rack->rc_tp->snd_una) ||
8628 		    (pkt_delta < tcp_sad_low_pps)){
8629 			/*
8630 			 * We don't decay idle connections
8631 			 * or ones that have a low input pps.
8632 			 */
8633 			return;
8634 		}
8635 		/* Decay the counters */
8636 		rack->r_ctl.ack_count = ctf_decay_count(rack->r_ctl.ack_count,
8637 							tcp_sad_decay_val);
8638 		rack->r_ctl.sack_count = ctf_decay_count(rack->r_ctl.sack_count,
8639 							 tcp_sad_decay_val);
8640 		rack->r_ctl.sack_moved_extra = ctf_decay_count(rack->r_ctl.sack_moved_extra,
8641 							       tcp_sad_decay_val);
8642 		rack->r_ctl.sack_noextra_move = ctf_decay_count(rack->r_ctl.sack_noextra_move,
8643 								tcp_sad_decay_val);
8644 #endif
8645 	}
8646 }
8647 
8648 static void
8649 rack_process_to_cumack(struct tcpcb *tp, struct tcp_rack *rack, register uint32_t th_ack, uint32_t cts, struct tcpopt *to)
8650 {
8651 	struct rack_sendmap *rsm, *rm;
8652 
8653 	/*
8654 	 * The ACK point is advancing to th_ack, we must drop off
8655 	 * the packets in the rack log and calculate any eligble
8656 	 * RTT's.
8657 	 */
8658 	rack->r_wanted_output = 1;
8659 more:
8660 	rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
8661 	if (rsm == NULL) {
8662 		if ((th_ack - 1) == tp->iss) {
8663 			/*
8664 			 * For the SYN incoming case we will not
8665 			 * have called tcp_output for the sending of
8666 			 * the SYN, so there will be no map. All
8667 			 * other cases should probably be a panic.
8668 			 */
8669 			return;
8670 		}
8671 		if (tp->t_flags & TF_SENTFIN) {
8672 			/* if we sent a FIN we often will not have map */
8673 			return;
8674 		}
8675 #ifdef INVARIANTS
8676 		panic("No rack map tp:%p for state:%d ack:%u rack:%p snd_una:%u snd_max:%u snd_nxt:%u\n",
8677 		      tp,
8678 		      tp->t_state, th_ack, rack,
8679 		      tp->snd_una, tp->snd_max, tp->snd_nxt);
8680 #endif
8681 		return;
8682 	}
8683 	if (SEQ_LT(th_ack, rsm->r_start)) {
8684 		/* Huh map is missing this */
8685 #ifdef INVARIANTS
8686 		printf("Rack map starts at r_start:%u for th_ack:%u huh? ts:%d rs:%d\n",
8687 		       rsm->r_start,
8688 		       th_ack, tp->t_state, rack->r_state);
8689 #endif
8690 		return;
8691 	}
8692 	rack_update_rtt(tp, rack, rsm, to, cts, CUM_ACKED, th_ack);
8693 	/* Now do we consume the whole thing? */
8694 	if (SEQ_GEQ(th_ack, rsm->r_end)) {
8695 		/* Its all consumed. */
8696 		uint32_t left;
8697 		uint8_t newly_acked;
8698 
8699 		rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_FREE, rsm->r_end, __LINE__);
8700 		rack->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
8701 		rsm->r_rtr_bytes = 0;
8702 		/* Record the time of highest cumack sent */
8703 		rack->r_ctl.rc_gp_cumack_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8704 		rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8705 #ifdef INVARIANTS
8706 		if (rm != rsm) {
8707 			panic("removing head in rack:%p rsm:%p rm:%p",
8708 			      rack, rsm, rm);
8709 		}
8710 #endif
8711 		if (rsm->r_in_tmap) {
8712 			TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8713 			rsm->r_in_tmap = 0;
8714 		}
8715 		newly_acked = 1;
8716 		if (rsm->r_flags & RACK_ACKED) {
8717 			/*
8718 			 * It was acked on the scoreboard -- remove
8719 			 * it from total
8720 			 */
8721 			rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
8722 			newly_acked = 0;
8723 		} else if (rsm->r_flags & RACK_SACK_PASSED) {
8724 			/*
8725 			 * There are segments ACKED on the
8726 			 * scoreboard further up. We are seeing
8727 			 * reordering.
8728 			 */
8729 			rsm->r_flags &= ~RACK_SACK_PASSED;
8730 			counter_u64_add(rack_reorder_seen, 1);
8731 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
8732 			rsm->r_flags |= RACK_ACKED;
8733 			rack->r_ctl.rc_reorder_ts = cts;
8734 			if (rack->r_ent_rec_ns) {
8735 				/*
8736 				 * We have sent no more, and we saw an sack
8737 				 * then ack arrive.
8738 				 */
8739 				rack->r_might_revert = 1;
8740 			}
8741 		}
8742 		if ((rsm->r_flags & RACK_TO_REXT) &&
8743 		    (tp->t_flags & TF_RCVD_TSTMP) &&
8744 		    (to->to_flags & TOF_TS) &&
8745 		    (tp->t_flags & TF_PREVVALID)) {
8746 			/*
8747 			 * We can use the timestamp to see
8748 			 * if this retransmission was from the
8749 			 * first transmit. If so we made a mistake.
8750 			 */
8751 			tp->t_flags &= ~TF_PREVVALID;
8752 			if (to->to_tsecr == rack_ts_to_msec(rsm->r_tim_lastsent[0])) {
8753 				/* The first transmit is what this ack is for */
8754 				rack_cong_signal(tp, CC_RTO_ERR, th_ack);
8755 			}
8756 		}
8757 		left = th_ack - rsm->r_end;
8758 		if (rack->app_limited_needs_set && newly_acked)
8759 			rack_need_set_test(tp, rack, rsm, th_ack, __LINE__, RACK_USE_END_OR_THACK);
8760 		/* Free back to zone */
8761 		rack_free(rack, rsm);
8762 		if (left) {
8763 			goto more;
8764 		}
8765 		/* Check for reneging */
8766 		rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
8767 		if (rsm && (rsm->r_flags & RACK_ACKED) && (th_ack == rsm->r_start)) {
8768 			/*
8769 			 * The peer has moved snd_una up to
8770 			 * the edge of this send, i.e. one
8771 			 * that it had previously acked. The only
8772 			 * way that can be true if the peer threw
8773 			 * away data (space issues) that it had
8774 			 * previously sacked (else it would have
8775 			 * given us snd_una up to (rsm->r_end).
8776 			 * We need to undo the acked markings here.
8777 			 *
8778 			 * Note we have to look to make sure th_ack is
8779 			 * our rsm->r_start in case we get an old ack
8780 			 * where th_ack is behind snd_una.
8781 			 */
8782 			rack_peer_reneges(rack, rsm, th_ack);
8783 		}
8784 		return;
8785 	}
8786 	if (rsm->r_flags & RACK_ACKED) {
8787 		/*
8788 		 * It was acked on the scoreboard -- remove it from
8789 		 * total for the part being cum-acked.
8790 		 */
8791 		rack->r_ctl.rc_sacked -= (th_ack - rsm->r_start);
8792 	}
8793 	/*
8794 	 * Clear the dup ack count for
8795 	 * the piece that remains.
8796 	 */
8797 	rsm->r_dupack = 0;
8798 	rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
8799 	if (rsm->r_rtr_bytes) {
8800 		/*
8801 		 * It was retransmitted adjust the
8802 		 * sack holes for what was acked.
8803 		 */
8804 		int ack_am;
8805 
8806 		ack_am = (th_ack - rsm->r_start);
8807 		if (ack_am >= rsm->r_rtr_bytes) {
8808 			rack->r_ctl.rc_holes_rxt -= ack_am;
8809 			rsm->r_rtr_bytes -= ack_am;
8810 		}
8811 	}
8812 	/*
8813 	 * Update where the piece starts and record
8814 	 * the time of send of highest cumack sent.
8815 	 */
8816 	rack->r_ctl.rc_gp_cumack_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8817 	rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_TRIM_HEAD, th_ack, __LINE__);
8818 	/* Now we need to move our offset forward too */
8819 	if (rsm->m && (rsm->orig_m_len != rsm->m->m_len)) {
8820 		/* Fix up the orig_m_len and possibly the mbuf offset */
8821 		rack_adjust_orig_mlen(rsm);
8822 	}
8823 	rsm->soff += (th_ack - rsm->r_start);
8824 	rsm->r_start = th_ack;
8825 	/* Now do we need to move the mbuf fwd too? */
8826 	if (rsm->m) {
8827 		while (rsm->soff >= rsm->m->m_len) {
8828 			rsm->soff -= rsm->m->m_len;
8829 			rsm->m = rsm->m->m_next;
8830 			KASSERT((rsm->m != NULL),
8831 				(" nrsm:%p hit at soff:%u null m",
8832 				 rsm, rsm->soff));
8833 		}
8834 		rsm->orig_m_len = rsm->m->m_len;
8835 	}
8836 	if (rack->app_limited_needs_set)
8837 		rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_BEG);
8838 }
8839 
8840 static void
8841 rack_handle_might_revert(struct tcpcb *tp, struct tcp_rack *rack)
8842 {
8843 	struct rack_sendmap *rsm;
8844 	int sack_pass_fnd = 0;
8845 
8846 	if (rack->r_might_revert) {
8847 		/*
8848 		 * Ok we have reordering, have not sent anything, we
8849 		 * might want to revert the congestion state if nothing
8850 		 * further has SACK_PASSED on it. Lets check.
8851 		 *
8852 		 * We also get here when we have DSACKs come in for
8853 		 * all the data that we FR'd. Note that a rxt or tlp
8854 		 * timer clears this from happening.
8855 		 */
8856 
8857 		TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
8858 			if (rsm->r_flags & RACK_SACK_PASSED) {
8859 				sack_pass_fnd = 1;
8860 				break;
8861 			}
8862 		}
8863 		if (sack_pass_fnd == 0) {
8864 			/*
8865 			 * We went into recovery
8866 			 * incorrectly due to reordering!
8867 			 */
8868 			int orig_cwnd;
8869 
8870 			rack->r_ent_rec_ns = 0;
8871 			orig_cwnd = tp->snd_cwnd;
8872 			tp->snd_cwnd = rack->r_ctl.rc_cwnd_at_erec;
8873 			tp->snd_ssthresh = rack->r_ctl.rc_ssthresh_at_erec;
8874 			tp->snd_recover = tp->snd_una;
8875 			rack_log_to_prr(rack, 14, orig_cwnd);
8876 			EXIT_RECOVERY(tp->t_flags);
8877 		}
8878 		rack->r_might_revert = 0;
8879 	}
8880 }
8881 
8882 #ifdef NETFLIX_EXP_DETECTION
8883 static void
8884 rack_do_detection(struct tcpcb *tp, struct tcp_rack *rack,  uint32_t bytes_this_ack, uint32_t segsiz)
8885 {
8886 	if ((rack->do_detection || tcp_force_detection) &&
8887 	    tcp_sack_to_ack_thresh &&
8888 	    tcp_sack_to_move_thresh &&
8889 	    ((rack->r_ctl.rc_num_maps_alloced > tcp_map_minimum) || rack->sack_attack_disable)) {
8890 		/*
8891 		 * We have thresholds set to find
8892 		 * possible attackers and disable sack.
8893 		 * Check them.
8894 		 */
8895 		uint64_t ackratio, moveratio, movetotal;
8896 
8897 		/* Log detecting */
8898 		rack_log_sad(rack, 1);
8899 		ackratio = (uint64_t)(rack->r_ctl.sack_count);
8900 		ackratio *= (uint64_t)(1000);
8901 		if (rack->r_ctl.ack_count)
8902 			ackratio /= (uint64_t)(rack->r_ctl.ack_count);
8903 		else {
8904 			/* We really should not hit here */
8905 			ackratio = 1000;
8906 		}
8907 		if ((rack->sack_attack_disable == 0) &&
8908 		    (ackratio > rack_highest_sack_thresh_seen))
8909 			rack_highest_sack_thresh_seen = (uint32_t)ackratio;
8910 		movetotal = rack->r_ctl.sack_moved_extra;
8911 		movetotal += rack->r_ctl.sack_noextra_move;
8912 		moveratio = rack->r_ctl.sack_moved_extra;
8913 		moveratio *= (uint64_t)1000;
8914 		if (movetotal)
8915 			moveratio /= movetotal;
8916 		else {
8917 			/* No moves, thats pretty good */
8918 			moveratio = 0;
8919 		}
8920 		if ((rack->sack_attack_disable == 0) &&
8921 		    (moveratio > rack_highest_move_thresh_seen))
8922 			rack_highest_move_thresh_seen = (uint32_t)moveratio;
8923 		if (rack->sack_attack_disable == 0) {
8924 			if ((ackratio > tcp_sack_to_ack_thresh) &&
8925 			    (moveratio > tcp_sack_to_move_thresh)) {
8926 				/* Disable sack processing */
8927 				rack->sack_attack_disable = 1;
8928 				if (rack->r_rep_attack == 0) {
8929 					rack->r_rep_attack = 1;
8930 					counter_u64_add(rack_sack_attacks_detected, 1);
8931 				}
8932 				if (tcp_attack_on_turns_on_logging) {
8933 					/*
8934 					 * Turn on logging, used for debugging
8935 					 * false positives.
8936 					 */
8937 					rack->rc_tp->t_logstate = tcp_attack_on_turns_on_logging;
8938 				}
8939 				/* Clamp the cwnd at flight size */
8940 				rack->r_ctl.rc_saved_cwnd = rack->rc_tp->snd_cwnd;
8941 				rack->rc_tp->snd_cwnd = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
8942 				rack_log_sad(rack, 2);
8943 			}
8944 		} else {
8945 			/* We are sack-disabled check for false positives */
8946 			if ((ackratio <= tcp_restoral_thresh) ||
8947 			    (rack->r_ctl.rc_num_maps_alloced  < tcp_map_minimum)) {
8948 				rack->sack_attack_disable = 0;
8949 				rack_log_sad(rack, 3);
8950 				/* Restart counting */
8951 				rack->r_ctl.sack_count = 0;
8952 				rack->r_ctl.sack_moved_extra = 0;
8953 				rack->r_ctl.sack_noextra_move = 1;
8954 				rack->r_ctl.ack_count = max(1,
8955 				      (bytes_this_ack / segsiz));
8956 
8957 				if (rack->r_rep_reverse == 0) {
8958 					rack->r_rep_reverse = 1;
8959 					counter_u64_add(rack_sack_attacks_reversed, 1);
8960 				}
8961 				/* Restore the cwnd */
8962 				if (rack->r_ctl.rc_saved_cwnd > rack->rc_tp->snd_cwnd)
8963 					rack->rc_tp->snd_cwnd = rack->r_ctl.rc_saved_cwnd;
8964 			}
8965 		}
8966 	}
8967 }
8968 #endif
8969 
8970 static void
8971 rack_note_dsack(struct tcp_rack *rack, tcp_seq start, tcp_seq end)
8972 {
8973 
8974 	uint32_t am;
8975 
8976 	if (SEQ_GT(end, start))
8977 		am = end - start;
8978 	else
8979 		am = 0;
8980 	/*
8981 	 * We keep track of how many DSACK blocks we get
8982 	 * after a recovery incident.
8983 	 */
8984 	rack->r_ctl.dsack_byte_cnt += am;
8985 	if (!IN_FASTRECOVERY(rack->rc_tp->t_flags) &&
8986 	    rack->r_ctl.retran_during_recovery &&
8987 	    (rack->r_ctl.dsack_byte_cnt >= rack->r_ctl.retran_during_recovery)) {
8988 		/*
8989 		 * False recovery most likely culprit is reordering. If
8990 		 * nothing else is missing we need to revert.
8991 		 */
8992 		rack->r_might_revert = 1;
8993 		rack_handle_might_revert(rack->rc_tp, rack);
8994 		rack->r_might_revert = 0;
8995 		rack->r_ctl.retran_during_recovery = 0;
8996 		rack->r_ctl.dsack_byte_cnt = 0;
8997 	}
8998 }
8999 
9000 static void
9001 rack_update_prr(struct tcpcb *tp, struct tcp_rack *rack, uint32_t changed, tcp_seq th_ack)
9002 {
9003 	/* Deal with changed and PRR here (in recovery only) */
9004 	uint32_t pipe, snd_una;
9005 
9006 	rack->r_ctl.rc_prr_delivered += changed;
9007 
9008 	if (sbavail(&rack->rc_inp->inp_socket->so_snd) <= (tp->snd_max - tp->snd_una)) {
9009 		/*
9010 		 * It is all outstanding, we are application limited
9011 		 * and thus we don't need more room to send anything.
9012 		 * Note we use tp->snd_una here and not th_ack because
9013 		 * the data as yet not been cut from the sb.
9014 		 */
9015 		rack->r_ctl.rc_prr_sndcnt = 0;
9016 		return;
9017 	}
9018 	/* Compute prr_sndcnt */
9019 	if (SEQ_GT(tp->snd_una, th_ack)) {
9020 		snd_una = tp->snd_una;
9021 	} else {
9022 		snd_una = th_ack;
9023 	}
9024 	pipe = ((tp->snd_max - snd_una) - rack->r_ctl.rc_sacked) + rack->r_ctl.rc_holes_rxt;
9025 	if (pipe > tp->snd_ssthresh) {
9026 		long sndcnt;
9027 
9028 		sndcnt = rack->r_ctl.rc_prr_delivered * tp->snd_ssthresh;
9029 		if (rack->r_ctl.rc_prr_recovery_fs > 0)
9030 			sndcnt /= (long)rack->r_ctl.rc_prr_recovery_fs;
9031 		else {
9032 			rack->r_ctl.rc_prr_sndcnt = 0;
9033 			rack_log_to_prr(rack, 9, 0);
9034 			sndcnt = 0;
9035 		}
9036 		sndcnt++;
9037 		if (sndcnt > (long)rack->r_ctl.rc_prr_out)
9038 			sndcnt -= rack->r_ctl.rc_prr_out;
9039 		else
9040 			sndcnt = 0;
9041 		rack->r_ctl.rc_prr_sndcnt = sndcnt;
9042 		rack_log_to_prr(rack, 10, 0);
9043 	} else {
9044 		uint32_t limit;
9045 
9046 		if (rack->r_ctl.rc_prr_delivered > rack->r_ctl.rc_prr_out)
9047 			limit = (rack->r_ctl.rc_prr_delivered - rack->r_ctl.rc_prr_out);
9048 		else
9049 			limit = 0;
9050 		if (changed > limit)
9051 			limit = changed;
9052 		limit += ctf_fixed_maxseg(tp);
9053 		if (tp->snd_ssthresh > pipe) {
9054 			rack->r_ctl.rc_prr_sndcnt = min((tp->snd_ssthresh - pipe), limit);
9055 			rack_log_to_prr(rack, 11, 0);
9056 		} else {
9057 			rack->r_ctl.rc_prr_sndcnt = min(0, limit);
9058 			rack_log_to_prr(rack, 12, 0);
9059 		}
9060 	}
9061 }
9062 
9063 static void
9064 rack_log_ack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th, int entered_recovery, int dup_ack_struck)
9065 {
9066 	uint32_t changed;
9067 	struct tcp_rack *rack;
9068 	struct rack_sendmap *rsm;
9069 	struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1];
9070 	register uint32_t th_ack;
9071 	int32_t i, j, k, num_sack_blks = 0;
9072 	uint32_t cts, acked, ack_point, sack_changed = 0;
9073 	int loop_start = 0, moved_two = 0;
9074 	uint32_t tsused;
9075 
9076 
9077 	INP_WLOCK_ASSERT(tp->t_inpcb);
9078 	if (th->th_flags & TH_RST) {
9079 		/* We don't log resets */
9080 		return;
9081 	}
9082 	rack = (struct tcp_rack *)tp->t_fb_ptr;
9083 	cts = tcp_get_usecs(NULL);
9084 	rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
9085 	changed = 0;
9086 	th_ack = th->th_ack;
9087 	if (rack->sack_attack_disable == 0)
9088 		rack_do_decay(rack);
9089 	if (BYTES_THIS_ACK(tp, th) >= ctf_fixed_maxseg(rack->rc_tp)) {
9090 		/*
9091 		 * You only get credit for
9092 		 * MSS and greater (and you get extra
9093 		 * credit for larger cum-ack moves).
9094 		 */
9095 		int ac;
9096 
9097 		ac = BYTES_THIS_ACK(tp, th) / ctf_fixed_maxseg(rack->rc_tp);
9098 		rack->r_ctl.ack_count += ac;
9099 		counter_u64_add(rack_ack_total, ac);
9100 	}
9101 	if (rack->r_ctl.ack_count > 0xfff00000) {
9102 		/*
9103 		 * reduce the number to keep us under
9104 		 * a uint32_t.
9105 		 */
9106 		rack->r_ctl.ack_count /= 2;
9107 		rack->r_ctl.sack_count /= 2;
9108 	}
9109 	if (SEQ_GT(th_ack, tp->snd_una)) {
9110 		rack_log_progress_event(rack, tp, ticks, PROGRESS_UPDATE, __LINE__);
9111 		tp->t_acktime = ticks;
9112 	}
9113 	if (rsm && SEQ_GT(th_ack, rsm->r_start))
9114 		changed = th_ack - rsm->r_start;
9115 	if (changed) {
9116 		rack_process_to_cumack(tp, rack, th_ack, cts, to);
9117 	}
9118 	if ((to->to_flags & TOF_SACK) == 0) {
9119 		/* We are done nothing left and no sack. */
9120 		rack_handle_might_revert(tp, rack);
9121 		/*
9122 		 * For cases where we struck a dup-ack
9123 		 * with no SACK, add to the changes so
9124 		 * PRR will work right.
9125 		 */
9126 		if (dup_ack_struck && (changed == 0)) {
9127 			changed += ctf_fixed_maxseg(rack->rc_tp);
9128 		}
9129 		goto out;
9130 	}
9131 	/* Sack block processing */
9132 	if (SEQ_GT(th_ack, tp->snd_una))
9133 		ack_point = th_ack;
9134 	else
9135 		ack_point = tp->snd_una;
9136 	for (i = 0; i < to->to_nsacks; i++) {
9137 		bcopy((to->to_sacks + i * TCPOLEN_SACK),
9138 		      &sack, sizeof(sack));
9139 		sack.start = ntohl(sack.start);
9140 		sack.end = ntohl(sack.end);
9141 		if (SEQ_GT(sack.end, sack.start) &&
9142 		    SEQ_GT(sack.start, ack_point) &&
9143 		    SEQ_LT(sack.start, tp->snd_max) &&
9144 		    SEQ_GT(sack.end, ack_point) &&
9145 		    SEQ_LEQ(sack.end, tp->snd_max)) {
9146 			sack_blocks[num_sack_blks] = sack;
9147 			num_sack_blks++;
9148 #ifdef NETFLIX_STATS
9149 		} else if (SEQ_LEQ(sack.start, th_ack) &&
9150 			   SEQ_LEQ(sack.end, th_ack)) {
9151 			/*
9152 			 * Its a D-SACK block.
9153 			 */
9154 			tcp_record_dsack(sack.start, sack.end);
9155 #endif
9156 			rack_note_dsack(rack, sack.start, sack.end);
9157 		}
9158 	}
9159 	/*
9160 	 * Sort the SACK blocks so we can update the rack scoreboard with
9161 	 * just one pass.
9162 	 */
9163 	num_sack_blks = sack_filter_blks(&rack->r_ctl.rack_sf, sack_blocks,
9164 					 num_sack_blks, th->th_ack);
9165 	ctf_log_sack_filter(rack->rc_tp, num_sack_blks, sack_blocks);
9166 	if (num_sack_blks == 0) {
9167 		/* Nothing to sack (DSACKs?) */
9168 		goto out_with_totals;
9169 	}
9170 	if (num_sack_blks < 2) {
9171 		/* Only one, we don't need to sort */
9172 		goto do_sack_work;
9173 	}
9174 	/* Sort the sacks */
9175 	for (i = 0; i < num_sack_blks; i++) {
9176 		for (j = i + 1; j < num_sack_blks; j++) {
9177 			if (SEQ_GT(sack_blocks[i].end, sack_blocks[j].end)) {
9178 				sack = sack_blocks[i];
9179 				sack_blocks[i] = sack_blocks[j];
9180 				sack_blocks[j] = sack;
9181 			}
9182 		}
9183 	}
9184 	/*
9185 	 * Now are any of the sack block ends the same (yes some
9186 	 * implementations send these)?
9187 	 */
9188 again:
9189 	if (num_sack_blks == 0)
9190 		goto out_with_totals;
9191 	if (num_sack_blks > 1) {
9192 		for (i = 0; i < num_sack_blks; i++) {
9193 			for (j = i + 1; j < num_sack_blks; j++) {
9194 				if (sack_blocks[i].end == sack_blocks[j].end) {
9195 					/*
9196 					 * Ok these two have the same end we
9197 					 * want the smallest end and then
9198 					 * throw away the larger and start
9199 					 * again.
9200 					 */
9201 					if (SEQ_LT(sack_blocks[j].start, sack_blocks[i].start)) {
9202 						/*
9203 						 * The second block covers
9204 						 * more area use that
9205 						 */
9206 						sack_blocks[i].start = sack_blocks[j].start;
9207 					}
9208 					/*
9209 					 * Now collapse out the dup-sack and
9210 					 * lower the count
9211 					 */
9212 					for (k = (j + 1); k < num_sack_blks; k++) {
9213 						sack_blocks[j].start = sack_blocks[k].start;
9214 						sack_blocks[j].end = sack_blocks[k].end;
9215 						j++;
9216 					}
9217 					num_sack_blks--;
9218 					goto again;
9219 				}
9220 			}
9221 		}
9222 	}
9223 do_sack_work:
9224 	/*
9225 	 * First lets look to see if
9226 	 * we have retransmitted and
9227 	 * can use the transmit next?
9228 	 */
9229 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
9230 	if (rsm &&
9231 	    SEQ_GT(sack_blocks[0].end, rsm->r_start) &&
9232 	    SEQ_LT(sack_blocks[0].start, rsm->r_end)) {
9233 		/*
9234 		 * We probably did the FR and the next
9235 		 * SACK in continues as we would expect.
9236 		 */
9237 		acked = rack_proc_sack_blk(tp, rack, &sack_blocks[0], to, &rsm, cts, &moved_two);
9238 		if (acked) {
9239 			rack->r_wanted_output = 1;
9240 			changed += acked;
9241 			sack_changed += acked;
9242 		}
9243 		if (num_sack_blks == 1) {
9244 			/*
9245 			 * This is what we would expect from
9246 			 * a normal implementation to happen
9247 			 * after we have retransmitted the FR,
9248 			 * i.e the sack-filter pushes down
9249 			 * to 1 block and the next to be retransmitted
9250 			 * is the sequence in the sack block (has more
9251 			 * are acked). Count this as ACK'd data to boost
9252 			 * up the chances of recovering any false positives.
9253 			 */
9254 			rack->r_ctl.ack_count += (acked / ctf_fixed_maxseg(rack->rc_tp));
9255 			counter_u64_add(rack_ack_total, (acked / ctf_fixed_maxseg(rack->rc_tp)));
9256 			counter_u64_add(rack_express_sack, 1);
9257 			if (rack->r_ctl.ack_count > 0xfff00000) {
9258 				/*
9259 				 * reduce the number to keep us under
9260 				 * a uint32_t.
9261 				 */
9262 				rack->r_ctl.ack_count /= 2;
9263 				rack->r_ctl.sack_count /= 2;
9264 			}
9265 			goto out_with_totals;
9266 		} else {
9267 			/*
9268 			 * Start the loop through the
9269 			 * rest of blocks, past the first block.
9270 			 */
9271 			moved_two = 0;
9272 			loop_start = 1;
9273 		}
9274 	}
9275 	/* Its a sack of some sort */
9276 	rack->r_ctl.sack_count++;
9277 	if (rack->r_ctl.sack_count > 0xfff00000) {
9278 		/*
9279 		 * reduce the number to keep us under
9280 		 * a uint32_t.
9281 		 */
9282 		rack->r_ctl.ack_count /= 2;
9283 		rack->r_ctl.sack_count /= 2;
9284 	}
9285 	counter_u64_add(rack_sack_total, 1);
9286 	if (rack->sack_attack_disable) {
9287 		/* An attacker disablement is in place */
9288 		if (num_sack_blks > 1) {
9289 			rack->r_ctl.sack_count += (num_sack_blks - 1);
9290 			rack->r_ctl.sack_moved_extra++;
9291 			counter_u64_add(rack_move_some, 1);
9292 			if (rack->r_ctl.sack_moved_extra > 0xfff00000) {
9293 				rack->r_ctl.sack_moved_extra /= 2;
9294 				rack->r_ctl.sack_noextra_move /= 2;
9295 			}
9296 		}
9297 		goto out;
9298 	}
9299 	rsm = rack->r_ctl.rc_sacklast;
9300 	for (i = loop_start; i < num_sack_blks; i++) {
9301 		acked = rack_proc_sack_blk(tp, rack, &sack_blocks[i], to, &rsm, cts, &moved_two);
9302 		if (acked) {
9303 			rack->r_wanted_output = 1;
9304 			changed += acked;
9305 			sack_changed += acked;
9306 		}
9307 		if (moved_two) {
9308 			/*
9309 			 * If we did not get a SACK for at least a MSS and
9310 			 * had to move at all, or if we moved more than our
9311 			 * threshold, it counts against the "extra" move.
9312 			 */
9313 			rack->r_ctl.sack_moved_extra += moved_two;
9314 			counter_u64_add(rack_move_some, 1);
9315 		} else {
9316 			/*
9317 			 * else we did not have to move
9318 			 * any more than we would expect.
9319 			 */
9320 			rack->r_ctl.sack_noextra_move++;
9321 			counter_u64_add(rack_move_none, 1);
9322 		}
9323 		if (moved_two && (acked < ctf_fixed_maxseg(rack->rc_tp))) {
9324 			/*
9325 			 * If the SACK was not a full MSS then
9326 			 * we add to sack_count the number of
9327 			 * MSS's (or possibly more than
9328 			 * a MSS if its a TSO send) we had to skip by.
9329 			 */
9330 			rack->r_ctl.sack_count += moved_two;
9331 			counter_u64_add(rack_sack_total, moved_two);
9332 		}
9333 		/*
9334 		 * Now we need to setup for the next
9335 		 * round. First we make sure we won't
9336 		 * exceed the size of our uint32_t on
9337 		 * the various counts, and then clear out
9338 		 * moved_two.
9339 		 */
9340 		if ((rack->r_ctl.sack_moved_extra > 0xfff00000) ||
9341 		    (rack->r_ctl.sack_noextra_move > 0xfff00000)) {
9342 			rack->r_ctl.sack_moved_extra /= 2;
9343 			rack->r_ctl.sack_noextra_move /= 2;
9344 		}
9345 		if (rack->r_ctl.sack_count > 0xfff00000) {
9346 			rack->r_ctl.ack_count /= 2;
9347 			rack->r_ctl.sack_count /= 2;
9348 		}
9349 		moved_two = 0;
9350 	}
9351 out_with_totals:
9352 	if (num_sack_blks > 1) {
9353 		/*
9354 		 * You get an extra stroke if
9355 		 * you have more than one sack-blk, this
9356 		 * could be where we are skipping forward
9357 		 * and the sack-filter is still working, or
9358 		 * it could be an attacker constantly
9359 		 * moving us.
9360 		 */
9361 		rack->r_ctl.sack_moved_extra++;
9362 		counter_u64_add(rack_move_some, 1);
9363 	}
9364 out:
9365 #ifdef NETFLIX_EXP_DETECTION
9366 	rack_do_detection(tp, rack, BYTES_THIS_ACK(tp, th), ctf_fixed_maxseg(rack->rc_tp));
9367 #endif
9368 	if (changed) {
9369 		/* Something changed cancel the rack timer */
9370 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
9371 	}
9372 	tsused = tcp_get_usecs(NULL);
9373 	rsm = tcp_rack_output(tp, rack, tsused);
9374 	if ((!IN_FASTRECOVERY(tp->t_flags)) &&
9375 	    rsm) {
9376 		/* Enter recovery */
9377 		rack->r_ctl.rc_rsm_start = rsm->r_start;
9378 		rack->r_ctl.rc_cwnd_at = tp->snd_cwnd;
9379 		rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh;
9380 		entered_recovery = 1;
9381 		rack_cong_signal(tp, CC_NDUPACK, tp->snd_una);
9382 		/*
9383 		 * When we enter recovery we need to assure we send
9384 		 * one packet.
9385 		 */
9386 		if (rack->rack_no_prr == 0) {
9387 			rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
9388 			rack_log_to_prr(rack, 8, 0);
9389 		}
9390 		rack->r_timer_override = 1;
9391 		rack->r_early = 0;
9392 		rack->r_ctl.rc_agg_early = 0;
9393 	} else if (IN_FASTRECOVERY(tp->t_flags) &&
9394 		   rsm &&
9395 		   (rack->r_rr_config == 3)) {
9396 		/*
9397 		 * Assure we can output and we get no
9398 		 * remembered pace time except the retransmit.
9399 		 */
9400 		rack->r_timer_override = 1;
9401 		rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
9402 		rack->r_ctl.rc_resend = rsm;
9403 	}
9404 	if (IN_FASTRECOVERY(tp->t_flags) &&
9405 	    (rack->rack_no_prr == 0) &&
9406 	    (entered_recovery == 0)) {
9407 		rack_update_prr(tp, rack, changed, th_ack);
9408 		if ((rsm && (rack->r_ctl.rc_prr_sndcnt >= ctf_fixed_maxseg(tp)) &&
9409 		     ((rack->rc_inp->inp_in_hpts == 0) &&
9410 		      ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)))) {
9411 			/*
9412 			 * If you are pacing output you don't want
9413 			 * to override.
9414 			 */
9415 			rack->r_early = 0;
9416 			rack->r_ctl.rc_agg_early = 0;
9417 			rack->r_timer_override = 1;
9418 		}
9419 	}
9420 }
9421 
9422 static void
9423 rack_strike_dupack(struct tcp_rack *rack)
9424 {
9425 	struct rack_sendmap *rsm;
9426 
9427 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
9428 	while (rsm && (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
9429 		rsm = TAILQ_NEXT(rsm, r_tnext);
9430 	}
9431 	if (rsm && (rsm->r_dupack < 0xff)) {
9432 		rsm->r_dupack++;
9433 		if (rsm->r_dupack >= DUP_ACK_THRESHOLD) {
9434 			struct timeval tv;
9435 			uint32_t cts;
9436 			/*
9437 			 * Here we see if we need to retransmit. For
9438 			 * a SACK type connection if enough time has passed
9439 			 * we will get a return of the rsm. For a non-sack
9440 			 * connection we will get the rsm returned if the
9441 			 * dupack value is 3 or more.
9442 			 */
9443 			cts = tcp_get_usecs(&tv);
9444 			rack->r_ctl.rc_resend = tcp_rack_output(rack->rc_tp, rack, cts);
9445 			if (rack->r_ctl.rc_resend != NULL) {
9446 				if (!IN_FASTRECOVERY(rack->rc_tp->t_flags)) {
9447 					rack_cong_signal(rack->rc_tp, CC_NDUPACK,
9448 							 rack->rc_tp->snd_una);
9449 				}
9450 				rack->r_wanted_output = 1;
9451 				rack->r_timer_override = 1;
9452 				rack_log_retran_reason(rack, rsm, __LINE__, 1, 3);
9453 			}
9454 		} else {
9455 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 3);
9456 		}
9457 	}
9458 }
9459 
9460 static void
9461 rack_check_bottom_drag(struct tcpcb *tp,
9462 		       struct tcp_rack *rack,
9463 		       struct socket *so, int32_t acked)
9464 {
9465 	uint32_t segsiz, minseg;
9466 
9467 	segsiz = ctf_fixed_maxseg(tp);
9468 	minseg = segsiz;
9469 
9470 	if (tp->snd_max == tp->snd_una) {
9471 		/*
9472 		 * We are doing dynamic pacing and we are way
9473 		 * under. Basically everything got acked while
9474 		 * we were still waiting on the pacer to expire.
9475 		 *
9476 		 * This means we need to boost the b/w in
9477 		 * addition to any earlier boosting of
9478 		 * the multipler.
9479 		 */
9480 		rack->rc_dragged_bottom = 1;
9481 		rack_validate_multipliers_at_or_above100(rack);
9482 		/*
9483 		 * Lets use the segment bytes acked plus
9484 		 * the lowest RTT seen as the basis to
9485 		 * form a b/w estimate. This will be off
9486 		 * due to the fact that the true estimate
9487 		 * should be around 1/2 the time of the RTT
9488 		 * but we can settle for that.
9489 		 */
9490 		if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_VALID) &&
9491 		    acked) {
9492 			uint64_t bw, calc_bw, rtt;
9493 
9494 			rtt = rack->r_ctl.rack_rs.rs_us_rtt;
9495 			if (rtt == 0) {
9496 				/* no us sample is there a ms one? */
9497 				if (rack->r_ctl.rack_rs.rs_rtt_lowest) {
9498 					rtt = rack->r_ctl.rack_rs.rs_rtt_lowest;
9499 				} else {
9500 					goto no_measurement;
9501 				}
9502 			}
9503 			bw = acked;
9504 			calc_bw = bw * 1000000;
9505 			calc_bw /= rtt;
9506 			if (rack->r_ctl.last_max_bw &&
9507 			    (rack->r_ctl.last_max_bw < calc_bw)) {
9508 				/*
9509 				 * If we have a last calculated max bw
9510 				 * enforce it.
9511 				 */
9512 				calc_bw = rack->r_ctl.last_max_bw;
9513 			}
9514 			/* now plop it in */
9515 			if (rack->rc_gp_filled == 0) {
9516 				if (calc_bw > ONE_POINT_TWO_MEG) {
9517 					/*
9518 					 * If we have no measurement
9519 					 * don't let us set in more than
9520 					 * 1.2Mbps. If we are still too
9521 					 * low after pacing with this we
9522 					 * will hopefully have a max b/w
9523 					 * available to sanity check things.
9524 					 */
9525 					calc_bw = ONE_POINT_TWO_MEG;
9526 				}
9527 				rack->r_ctl.rc_rtt_diff = 0;
9528 				rack->r_ctl.gp_bw = calc_bw;
9529 				rack->rc_gp_filled = 1;
9530 				if (rack->r_ctl.num_measurements < RACK_REQ_AVG)
9531 					rack->r_ctl.num_measurements = RACK_REQ_AVG;
9532 				rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
9533 			} else if (calc_bw > rack->r_ctl.gp_bw) {
9534 				rack->r_ctl.rc_rtt_diff = 0;
9535 				if (rack->r_ctl.num_measurements < RACK_REQ_AVG)
9536 					rack->r_ctl.num_measurements = RACK_REQ_AVG;
9537 				rack->r_ctl.gp_bw = calc_bw;
9538 				rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
9539 			} else
9540 				rack_increase_bw_mul(rack, -1, 0, 0, 1);
9541 			if ((rack->gp_ready == 0) &&
9542 			    (rack->r_ctl.num_measurements >= rack->r_ctl.req_measurements)) {
9543 				/* We have enough measurements now */
9544 				rack->gp_ready = 1;
9545 				rack_set_cc_pacing(rack);
9546 				if (rack->defer_options)
9547 					rack_apply_deferred_options(rack);
9548 			}
9549 			/*
9550 			 * For acks over 1mss we do a extra boost to simulate
9551 			 * where we would get 2 acks (we want 110 for the mul).
9552 			 */
9553 			if (acked > segsiz)
9554 				rack_increase_bw_mul(rack, -1, 0, 0, 1);
9555 		} else {
9556 			/*
9557 			 * zero rtt possibly?, settle for just an old increase.
9558 			 */
9559 no_measurement:
9560 			rack_increase_bw_mul(rack, -1, 0, 0, 1);
9561 		}
9562 	} else if ((IN_FASTRECOVERY(tp->t_flags) == 0) &&
9563 		   (sbavail(&so->so_snd) > max((segsiz * (4 + rack_req_segs)),
9564 					       minseg)) &&
9565 		   (rack->r_ctl.cwnd_to_use > max((segsiz * (rack_req_segs + 2)), minseg)) &&
9566 		   (tp->snd_wnd > max((segsiz * (rack_req_segs + 2)), minseg)) &&
9567 		   (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) <=
9568 		    (segsiz * rack_req_segs))) {
9569 		/*
9570 		 * We are doing dynamic GP pacing and
9571 		 * we have everything except 1MSS or less
9572 		 * bytes left out. We are still pacing away.
9573 		 * And there is data that could be sent, This
9574 		 * means we are inserting delayed ack time in
9575 		 * our measurements because we are pacing too slow.
9576 		 */
9577 		rack_validate_multipliers_at_or_above100(rack);
9578 		rack->rc_dragged_bottom = 1;
9579 		rack_increase_bw_mul(rack, -1, 0, 0, 1);
9580 	}
9581 }
9582 
9583 
9584 
9585 static void
9586 rack_gain_for_fastoutput(struct tcp_rack *rack, struct tcpcb *tp, struct socket *so, uint32_t acked_amount)
9587 {
9588 	/*
9589 	 * The fast output path is enabled and we
9590 	 * have moved the cumack forward. Lets see if
9591 	 * we can expand forward the fast path length by
9592 	 * that amount. What we would ideally like to
9593 	 * do is increase the number of bytes in the
9594 	 * fast path block (left_to_send) by the
9595 	 * acked amount. However we have to gate that
9596 	 * by two factors:
9597 	 * 1) The amount outstanding and the rwnd of the peer
9598 	 *    (i.e. we don't want to exceed the rwnd of the peer).
9599 	 *    <and>
9600 	 * 2) The amount of data left in the socket buffer (i.e.
9601 	 *    we can't send beyond what is in the buffer).
9602 	 *
9603 	 * Note that this does not take into account any increase
9604 	 * in the cwnd. We will only extend the fast path by
9605 	 * what was acked.
9606 	 */
9607 	uint32_t new_total, gating_val;
9608 
9609 	new_total = acked_amount + rack->r_ctl.fsb.left_to_send;
9610 	gating_val = min((sbavail(&so->so_snd) - (tp->snd_max - tp->snd_una)),
9611 			 (tp->snd_wnd - (tp->snd_max - tp->snd_una)));
9612 	if (new_total <= gating_val) {
9613 		/* We can increase left_to_send by the acked amount */
9614 		counter_u64_add(rack_extended_rfo, 1);
9615 		rack->r_ctl.fsb.left_to_send = new_total;
9616 		KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(&rack->rc_inp->inp_socket->so_snd) - (tp->snd_max - tp->snd_una))),
9617 			("rack:%p left_to_send:%u sbavail:%u out:%u",
9618 			 rack, rack->r_ctl.fsb.left_to_send,
9619 			 sbavail(&rack->rc_inp->inp_socket->so_snd),
9620 			 (tp->snd_max - tp->snd_una)));
9621 
9622 	}
9623 }
9624 
9625 static void
9626 rack_adjust_sendmap(struct tcp_rack *rack, struct sockbuf *sb, tcp_seq snd_una)
9627 {
9628 	/*
9629 	 * Here any sendmap entry that points to the
9630 	 * beginning mbuf must be adjusted to the correct
9631 	 * offset. This must be called with:
9632 	 * 1) The socket buffer locked
9633 	 * 2) snd_una adjusted to its new postion.
9634 	 *
9635 	 * Note that (2) implies rack_ack_received has also
9636 	 * been called.
9637 	 *
9638 	 * We grab the first mbuf in the socket buffer and
9639 	 * then go through the front of the sendmap, recalculating
9640 	 * the stored offset for any sendmap entry that has
9641 	 * that mbuf. We must use the sb functions to do this
9642 	 * since its possible an add was done has well as
9643 	 * the subtraction we may have just completed. This should
9644 	 * not be a penalty though, since we just referenced the sb
9645 	 * to go in and trim off the mbufs that we freed (of course
9646 	 * there will be a penalty for the sendmap references though).
9647 	 */
9648 	struct mbuf *m;
9649 	struct rack_sendmap *rsm;
9650 
9651 	SOCKBUF_LOCK_ASSERT(sb);
9652 	m = sb->sb_mb;
9653 	rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
9654 	if ((rsm == NULL) || (m == NULL)) {
9655 		/* Nothing outstanding */
9656 		return;
9657 	}
9658 	while (rsm->m && (rsm->m == m)) {
9659 		/* one to adjust */
9660 #ifdef INVARIANTS
9661 		struct mbuf *tm;
9662 		uint32_t soff;
9663 
9664 		tm = sbsndmbuf(sb, (rsm->r_start - snd_una), &soff);
9665 		if (rsm->orig_m_len != m->m_len) {
9666 			rack_adjust_orig_mlen(rsm);
9667 		}
9668 		if (rsm->soff != soff) {
9669 			/*
9670 			 * This is not a fatal error, we anticipate it
9671 			 * might happen (the else code), so we count it here
9672 			 * so that under invariant we can see that it really
9673 			 * does happen.
9674 			 */
9675 			counter_u64_add(rack_adjust_map_bw, 1);
9676 		}
9677 		rsm->m = tm;
9678 		rsm->soff = soff;
9679 		if (tm)
9680 			rsm->orig_m_len = rsm->m->m_len;
9681 		else
9682 			rsm->orig_m_len = 0;
9683 #else
9684 		rsm->m = sbsndmbuf(sb, (rsm->r_start - snd_una), &rsm->soff);
9685 		if (rsm->m)
9686 			rsm->orig_m_len = rsm->m->m_len;
9687 		else
9688 			rsm->orig_m_len = 0;
9689 #endif
9690 		rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree,
9691 			      rsm);
9692 		if (rsm == NULL)
9693 			break;
9694 	}
9695 }
9696 
9697 /*
9698  * Return value of 1, we do not need to call rack_process_data().
9699  * return value of 0, rack_process_data can be called.
9700  * For ret_val if its 0 the TCP is locked, if its non-zero
9701  * its unlocked and probably unsafe to touch the TCB.
9702  */
9703 static int
9704 rack_process_ack(struct mbuf *m, struct tcphdr *th, struct socket *so,
9705     struct tcpcb *tp, struct tcpopt *to,
9706     uint32_t tiwin, int32_t tlen,
9707     int32_t * ofia, int32_t thflags, int32_t *ret_val)
9708 {
9709 	int32_t ourfinisacked = 0;
9710 	int32_t nsegs, acked_amount;
9711 	int32_t acked;
9712 	struct mbuf *mfree;
9713 	struct tcp_rack *rack;
9714 	int32_t under_pacing = 0;
9715 	int32_t recovery = 0;
9716 
9717 	rack = (struct tcp_rack *)tp->t_fb_ptr;
9718 	if (SEQ_GT(th->th_ack, tp->snd_max)) {
9719 		__ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val,
9720 				      &rack->r_ctl.challenge_ack_ts,
9721 				      &rack->r_ctl.challenge_ack_cnt);
9722 		rack->r_wanted_output = 1;
9723 		return (1);
9724 	}
9725 	if (rack->gp_ready &&
9726 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
9727 		under_pacing = 1;
9728 	}
9729 	if (SEQ_GEQ(th->th_ack, tp->snd_una) || to->to_nsacks) {
9730 		int in_rec, dup_ack_struck = 0;
9731 
9732 		in_rec = IN_FASTRECOVERY(tp->t_flags);
9733 		if (rack->rc_in_persist) {
9734 			tp->t_rxtshift = 0;
9735 			RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
9736 				      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
9737 		}
9738 		if ((th->th_ack == tp->snd_una) && (tiwin == tp->snd_wnd)) {
9739 			rack_strike_dupack(rack);
9740 			dup_ack_struck = 1;
9741 		}
9742 		rack_log_ack(tp, to, th, ((in_rec == 0) && IN_FASTRECOVERY(tp->t_flags)), dup_ack_struck);
9743 	}
9744 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
9745 		/*
9746 		 * Old ack, behind (or duplicate to) the last one rcv'd
9747 		 * Note: We mark reordering is occuring if its
9748 		 * less than and we have not closed our window.
9749 		 */
9750 		if (SEQ_LT(th->th_ack, tp->snd_una) && (sbspace(&so->so_rcv) > ctf_fixed_maxseg(tp))) {
9751 			counter_u64_add(rack_reorder_seen, 1);
9752 			rack->r_ctl.rc_reorder_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
9753 		}
9754 		return (0);
9755 	}
9756 	/*
9757 	 * If we reach this point, ACK is not a duplicate, i.e., it ACKs
9758 	 * something we sent.
9759 	 */
9760 	if (tp->t_flags & TF_NEEDSYN) {
9761 		/*
9762 		 * T/TCP: Connection was half-synchronized, and our SYN has
9763 		 * been ACK'd (so connection is now fully synchronized).  Go
9764 		 * to non-starred state, increment snd_una for ACK of SYN,
9765 		 * and check if we can do window scaling.
9766 		 */
9767 		tp->t_flags &= ~TF_NEEDSYN;
9768 		tp->snd_una++;
9769 		/* Do window scaling? */
9770 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
9771 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
9772 			tp->rcv_scale = tp->request_r_scale;
9773 			/* Send window already scaled. */
9774 		}
9775 	}
9776 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
9777 	INP_WLOCK_ASSERT(tp->t_inpcb);
9778 
9779 	acked = BYTES_THIS_ACK(tp, th);
9780 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
9781 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
9782 	/*
9783 	 * If we just performed our first retransmit, and the ACK arrives
9784 	 * within our recovery window, then it was a mistake to do the
9785 	 * retransmit in the first place.  Recover our original cwnd and
9786 	 * ssthresh, and proceed to transmit where we left off.
9787 	 */
9788 	if ((tp->t_flags & TF_PREVVALID) &&
9789 	    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
9790 		tp->t_flags &= ~TF_PREVVALID;
9791 		if (tp->t_rxtshift == 1 &&
9792 		    (int)(ticks - tp->t_badrxtwin) < 0)
9793 			rack_cong_signal(tp, CC_RTO_ERR, th->th_ack);
9794 	}
9795 	if (acked) {
9796 		/* assure we are not backed off */
9797 		tp->t_rxtshift = 0;
9798 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
9799 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
9800 		rack->rc_tlp_in_progress = 0;
9801 		rack->r_ctl.rc_tlp_cnt_out = 0;
9802 		/*
9803 		 * If it is the RXT timer we want to
9804 		 * stop it, so we can restart a TLP.
9805 		 */
9806 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
9807 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
9808 #ifdef NETFLIX_HTTP_LOGGING
9809 		tcp_http_check_for_comp(rack->rc_tp, th->th_ack);
9810 #endif
9811 	}
9812 	/*
9813 	 * If we have a timestamp reply, update smoothed round trip time. If
9814 	 * no timestamp is present but transmit timer is running and timed
9815 	 * sequence number was acked, update smoothed round trip time. Since
9816 	 * we now have an rtt measurement, cancel the timer backoff (cf.,
9817 	 * Phil Karn's retransmit alg.). Recompute the initial retransmit
9818 	 * timer.
9819 	 *
9820 	 * Some boxes send broken timestamp replies during the SYN+ACK
9821 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
9822 	 * and blow up the retransmit timer.
9823 	 */
9824 	/*
9825 	 * If all outstanding data is acked, stop retransmit timer and
9826 	 * remember to restart (more output or persist). If there is more
9827 	 * data to be acked, restart retransmit timer, using current
9828 	 * (possibly backed-off) value.
9829 	 */
9830 	if (acked == 0) {
9831 		if (ofia)
9832 			*ofia = ourfinisacked;
9833 		return (0);
9834 	}
9835 	if (IN_RECOVERY(tp->t_flags)) {
9836 		if (SEQ_LT(th->th_ack, tp->snd_recover) &&
9837 		    (SEQ_LT(th->th_ack, tp->snd_max))) {
9838 			tcp_rack_partialack(tp);
9839 		} else {
9840 			rack_post_recovery(tp, th->th_ack);
9841 			recovery = 1;
9842 		}
9843 	}
9844 	/*
9845 	 * Let the congestion control algorithm update congestion control
9846 	 * related information. This typically means increasing the
9847 	 * congestion window.
9848 	 */
9849 	rack_ack_received(tp, rack, th->th_ack, nsegs, CC_ACK, recovery);
9850 	SOCKBUF_LOCK(&so->so_snd);
9851 	acked_amount = min(acked, (int)sbavail(&so->so_snd));
9852 	tp->snd_wnd -= acked_amount;
9853 	mfree = sbcut_locked(&so->so_snd, acked_amount);
9854 	if ((sbused(&so->so_snd) == 0) &&
9855 	    (acked > acked_amount) &&
9856 	    (tp->t_state >= TCPS_FIN_WAIT_1) &&
9857 	    (tp->t_flags & TF_SENTFIN)) {
9858 		/*
9859 		 * We must be sure our fin
9860 		 * was sent and acked (we can be
9861 		 * in FIN_WAIT_1 without having
9862 		 * sent the fin).
9863 		 */
9864 		ourfinisacked = 1;
9865 	}
9866 	tp->snd_una = th->th_ack;
9867 	if (acked_amount && sbavail(&so->so_snd))
9868 		rack_adjust_sendmap(rack, &so->so_snd, tp->snd_una);
9869 	rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
9870 	/* NB: sowwakeup_locked() does an implicit unlock. */
9871 	sowwakeup_locked(so);
9872 	m_freem(mfree);
9873 	if (SEQ_GT(tp->snd_una, tp->snd_recover))
9874 		tp->snd_recover = tp->snd_una;
9875 
9876 	if (SEQ_LT(tp->snd_nxt, tp->snd_una)) {
9877 		tp->snd_nxt = tp->snd_una;
9878 	}
9879 	if (under_pacing &&
9880 	    (rack->use_fixed_rate == 0) &&
9881 	    (rack->in_probe_rtt == 0) &&
9882 	    rack->rc_gp_dyn_mul &&
9883 	    rack->rc_always_pace) {
9884 		/* Check if we are dragging bottom */
9885 		rack_check_bottom_drag(tp, rack, so, acked);
9886 	}
9887 	if (tp->snd_una == tp->snd_max) {
9888 		/* Nothing left outstanding */
9889 		tp->t_flags &= ~TF_PREVVALID;
9890 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
9891 		rack->r_ctl.retran_during_recovery = 0;
9892 		rack->r_ctl.dsack_byte_cnt = 0;
9893 		if (rack->r_ctl.rc_went_idle_time == 0)
9894 			rack->r_ctl.rc_went_idle_time = 1;
9895 		rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
9896 		if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0)
9897 			tp->t_acktime = 0;
9898 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
9899 		/* Set need output so persist might get set */
9900 		rack->r_wanted_output = 1;
9901 		sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
9902 		if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
9903 		    (sbavail(&so->so_snd) == 0) &&
9904 		    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
9905 			/*
9906 			 * The socket was gone and the
9907 			 * peer sent data (now or in the past), time to
9908 			 * reset him.
9909 			 */
9910 			*ret_val = 1;
9911 			/* tcp_close will kill the inp pre-log the Reset */
9912 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
9913 			tp = tcp_close(tp);
9914 			ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, tlen);
9915 			return (1);
9916 		}
9917 	}
9918 	if (ofia)
9919 		*ofia = ourfinisacked;
9920 	return (0);
9921 }
9922 
9923 static void
9924 rack_collapsed_window(struct tcp_rack *rack)
9925 {
9926 	/*
9927 	 * Now we must walk the
9928 	 * send map and divide the
9929 	 * ones left stranded. These
9930 	 * guys can't cause us to abort
9931 	 * the connection and are really
9932 	 * "unsent". However if a buggy
9933 	 * client actually did keep some
9934 	 * of the data i.e. collapsed the win
9935 	 * and refused to ack and then opened
9936 	 * the win and acked that data. We would
9937 	 * get into an ack war, the simplier
9938 	 * method then of just pretending we
9939 	 * did not send those segments something
9940 	 * won't work.
9941 	 */
9942 	struct rack_sendmap *rsm, *nrsm, fe, *insret;
9943 	tcp_seq max_seq;
9944 
9945 	max_seq = rack->rc_tp->snd_una + rack->rc_tp->snd_wnd;
9946 	memset(&fe, 0, sizeof(fe));
9947 	fe.r_start = max_seq;
9948 	/* Find the first seq past or at maxseq */
9949 	rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
9950 	if (rsm == NULL) {
9951 		/* Nothing to do strange */
9952 		rack->rc_has_collapsed = 0;
9953 		return;
9954 	}
9955 	/*
9956 	 * Now do we need to split at
9957 	 * the collapse point?
9958 	 */
9959 	if (SEQ_GT(max_seq, rsm->r_start)) {
9960 		nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
9961 		if (nrsm == NULL) {
9962 			/* We can't get a rsm, mark all? */
9963 			nrsm = rsm;
9964 			goto no_split;
9965 		}
9966 		/* Clone it */
9967 		rack_clone_rsm(rack, nrsm, rsm, max_seq);
9968 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
9969 #ifdef INVARIANTS
9970 		if (insret != NULL) {
9971 			panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
9972 			      nrsm, insret, rack, rsm);
9973 		}
9974 #endif
9975 		rack_log_map_chg(rack->rc_tp, rack, NULL, rsm, nrsm, MAP_SPLIT, max_seq, __LINE__);
9976 		if (rsm->r_in_tmap) {
9977 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
9978 			nrsm->r_in_tmap = 1;
9979 		}
9980 		/*
9981 		 * Set in the new RSM as the
9982 		 * collapsed starting point
9983 		 */
9984 		rsm = nrsm;
9985 	}
9986 no_split:
9987 	counter_u64_add(rack_collapsed_win, 1);
9988 	RB_FOREACH_FROM(nrsm, rack_rb_tree_head, rsm) {
9989 		nrsm->r_flags |= RACK_RWND_COLLAPSED;
9990 	}
9991 	rack->rc_has_collapsed = 1;
9992 }
9993 
9994 static void
9995 rack_un_collapse_window(struct tcp_rack *rack)
9996 {
9997 	struct rack_sendmap *rsm;
9998 
9999 	RB_FOREACH_REVERSE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
10000 		if (rsm->r_flags & RACK_RWND_COLLAPSED)
10001 			rsm->r_flags &= ~RACK_RWND_COLLAPSED;
10002 		else
10003 			break;
10004 	}
10005 	rack->rc_has_collapsed = 0;
10006 }
10007 
10008 static void
10009 rack_handle_delayed_ack(struct tcpcb *tp, struct tcp_rack *rack,
10010 			int32_t tlen, int32_t tfo_syn)
10011 {
10012 	if (DELAY_ACK(tp, tlen) || tfo_syn) {
10013 		if (rack->rc_dack_mode &&
10014 		    (tlen > 500) &&
10015 		    (rack->rc_dack_toggle == 1)) {
10016 			goto no_delayed_ack;
10017 		}
10018 		rack_timer_cancel(tp, rack,
10019 				  rack->r_ctl.rc_rcvtime, __LINE__);
10020 		tp->t_flags |= TF_DELACK;
10021 	} else {
10022 no_delayed_ack:
10023 		rack->r_wanted_output = 1;
10024 		tp->t_flags |= TF_ACKNOW;
10025 		if (rack->rc_dack_mode) {
10026 			if (tp->t_flags & TF_DELACK)
10027 				rack->rc_dack_toggle = 1;
10028 			else
10029 				rack->rc_dack_toggle = 0;
10030 		}
10031 	}
10032 }
10033 
10034 static void
10035 rack_validate_fo_sendwin_up(struct tcpcb *tp, struct tcp_rack *rack)
10036 {
10037 	/*
10038 	 * If fast output is in progress, lets validate that
10039 	 * the new window did not shrink on us and make it
10040 	 * so fast output should end.
10041 	 */
10042 	if (rack->r_fast_output) {
10043 		uint32_t out;
10044 
10045 		/*
10046 		 * Calculate what we will send if left as is
10047 		 * and compare that to our send window.
10048 		 */
10049 		out = ctf_outstanding(tp);
10050 		if ((out + rack->r_ctl.fsb.left_to_send) > tp->snd_wnd) {
10051 			/* ok we have an issue */
10052 			if (out >= tp->snd_wnd) {
10053 				/* Turn off fast output the window is met or collapsed */
10054 				rack->r_fast_output = 0;
10055 			} else {
10056 				/* we have some room left */
10057 				rack->r_ctl.fsb.left_to_send = tp->snd_wnd - out;
10058 				if (rack->r_ctl.fsb.left_to_send < ctf_fixed_maxseg(tp)) {
10059 					/* If not at least 1 full segment never mind */
10060 					rack->r_fast_output = 0;
10061 				}
10062 			}
10063 		}
10064 	}
10065 }
10066 
10067 
10068 /*
10069  * Return value of 1, the TCB is unlocked and most
10070  * likely gone, return value of 0, the TCP is still
10071  * locked.
10072  */
10073 static int
10074 rack_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so,
10075     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
10076     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
10077 {
10078 	/*
10079 	 * Update window information. Don't look at window if no ACK: TAC's
10080 	 * send garbage on first SYN.
10081 	 */
10082 	int32_t nsegs;
10083 	int32_t tfo_syn;
10084 	struct tcp_rack *rack;
10085 
10086 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10087 	INP_WLOCK_ASSERT(tp->t_inpcb);
10088 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
10089 	if ((thflags & TH_ACK) &&
10090 	    (SEQ_LT(tp->snd_wl1, th->th_seq) ||
10091 	    (tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) ||
10092 	    (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) {
10093 		/* keep track of pure window updates */
10094 		if (tlen == 0 &&
10095 		    tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd)
10096 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
10097 		tp->snd_wnd = tiwin;
10098 		rack_validate_fo_sendwin_up(tp, rack);
10099 		tp->snd_wl1 = th->th_seq;
10100 		tp->snd_wl2 = th->th_ack;
10101 		if (tp->snd_wnd > tp->max_sndwnd)
10102 			tp->max_sndwnd = tp->snd_wnd;
10103 		rack->r_wanted_output = 1;
10104 	} else if (thflags & TH_ACK) {
10105 		if ((tp->snd_wl2 == th->th_ack) && (tiwin < tp->snd_wnd)) {
10106 			tp->snd_wnd = tiwin;
10107 			rack_validate_fo_sendwin_up(tp, rack);
10108 			tp->snd_wl1 = th->th_seq;
10109 			tp->snd_wl2 = th->th_ack;
10110 		}
10111 	}
10112 	if (tp->snd_wnd < ctf_outstanding(tp))
10113 		/* The peer collapsed the window */
10114 		rack_collapsed_window(rack);
10115 	else if (rack->rc_has_collapsed)
10116 		rack_un_collapse_window(rack);
10117 	/* Was persist timer active and now we have window space? */
10118 	if ((rack->rc_in_persist != 0) &&
10119 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
10120 				rack->r_ctl.rc_pace_min_segs))) {
10121 		rack_exit_persist(tp, rack, rack->r_ctl.rc_rcvtime);
10122 		tp->snd_nxt = tp->snd_max;
10123 		/* Make sure we output to start the timer */
10124 		rack->r_wanted_output = 1;
10125 	}
10126 	/* Do we enter persists? */
10127 	if ((rack->rc_in_persist == 0) &&
10128 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
10129 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
10130 	    (tp->snd_max == tp->snd_una) &&
10131 	    sbavail(&tp->t_inpcb->inp_socket->so_snd) &&
10132 	    (sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) {
10133 		/*
10134 		 * Here the rwnd is less than
10135 		 * the pacing size, we are established,
10136 		 * nothing is outstanding, and there is
10137 		 * data to send. Enter persists.
10138 		 */
10139 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
10140 	}
10141 	if (tp->t_flags2 & TF2_DROP_AF_DATA) {
10142 		m_freem(m);
10143 		return (0);
10144 	}
10145 	/*
10146 	 * don't process the URG bit, ignore them drag
10147 	 * along the up.
10148 	 */
10149 	tp->rcv_up = tp->rcv_nxt;
10150 	INP_WLOCK_ASSERT(tp->t_inpcb);
10151 
10152 	/*
10153 	 * Process the segment text, merging it into the TCP sequencing
10154 	 * queue, and arranging for acknowledgment of receipt if necessary.
10155 	 * This process logically involves adjusting tp->rcv_wnd as data is
10156 	 * presented to the user (this happens in tcp_usrreq.c, case
10157 	 * PRU_RCVD).  If a FIN has already been received on this connection
10158 	 * then we just ignore the text.
10159 	 */
10160 	tfo_syn = ((tp->t_state == TCPS_SYN_RECEIVED) &&
10161 		   IS_FASTOPEN(tp->t_flags));
10162 	if ((tlen || (thflags & TH_FIN) || (tfo_syn && tlen > 0)) &&
10163 	    TCPS_HAVERCVDFIN(tp->t_state) == 0) {
10164 		tcp_seq save_start = th->th_seq;
10165 		tcp_seq save_rnxt  = tp->rcv_nxt;
10166 		int     save_tlen  = tlen;
10167 
10168 		m_adj(m, drop_hdrlen);	/* delayed header drop */
10169 		/*
10170 		 * Insert segment which includes th into TCP reassembly
10171 		 * queue with control block tp.  Set thflags to whether
10172 		 * reassembly now includes a segment with FIN.  This handles
10173 		 * the common case inline (segment is the next to be
10174 		 * received on an established connection, and the queue is
10175 		 * empty), avoiding linkage into and removal from the queue
10176 		 * and repetition of various conversions. Set DELACK for
10177 		 * segments received in order, but ack immediately when
10178 		 * segments are out of order (so fast retransmit can work).
10179 		 */
10180 		if (th->th_seq == tp->rcv_nxt &&
10181 		    SEGQ_EMPTY(tp) &&
10182 		    (TCPS_HAVEESTABLISHED(tp->t_state) ||
10183 		    tfo_syn)) {
10184 #ifdef NETFLIX_SB_LIMITS
10185 			u_int mcnt, appended;
10186 
10187 			if (so->so_rcv.sb_shlim) {
10188 				mcnt = m_memcnt(m);
10189 				appended = 0;
10190 				if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
10191 				    CFO_NOSLEEP, NULL) == false) {
10192 					counter_u64_add(tcp_sb_shlim_fails, 1);
10193 					m_freem(m);
10194 					return (0);
10195 				}
10196 			}
10197 #endif
10198 			rack_handle_delayed_ack(tp, rack, tlen, tfo_syn);
10199 			tp->rcv_nxt += tlen;
10200 			if (tlen &&
10201 			    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
10202 			    (tp->t_fbyte_in == 0)) {
10203 				tp->t_fbyte_in = ticks;
10204 				if (tp->t_fbyte_in == 0)
10205 					tp->t_fbyte_in = 1;
10206 				if (tp->t_fbyte_out && tp->t_fbyte_in)
10207 					tp->t_flags2 |= TF2_FBYTES_COMPLETE;
10208 			}
10209 			thflags = th->th_flags & TH_FIN;
10210 			KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
10211 			KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
10212 			SOCKBUF_LOCK(&so->so_rcv);
10213 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
10214 				m_freem(m);
10215 			} else
10216 #ifdef NETFLIX_SB_LIMITS
10217 				appended =
10218 #endif
10219 					sbappendstream_locked(&so->so_rcv, m, 0);
10220 
10221 			rack_log_wakeup(tp,rack, &so->so_rcv, tlen, 1);
10222 			/* NB: sorwakeup_locked() does an implicit unlock. */
10223 			sorwakeup_locked(so);
10224 #ifdef NETFLIX_SB_LIMITS
10225 			if (so->so_rcv.sb_shlim && appended != mcnt)
10226 				counter_fo_release(so->so_rcv.sb_shlim,
10227 				    mcnt - appended);
10228 #endif
10229 		} else {
10230 			/*
10231 			 * XXX: Due to the header drop above "th" is
10232 			 * theoretically invalid by now.  Fortunately
10233 			 * m_adj() doesn't actually frees any mbufs when
10234 			 * trimming from the head.
10235 			 */
10236 			tcp_seq temp = save_start;
10237 
10238 			thflags = tcp_reass(tp, th, &temp, &tlen, m);
10239 			tp->t_flags |= TF_ACKNOW;
10240 			if (tp->t_flags & TF_WAKESOR) {
10241 				tp->t_flags &= ~TF_WAKESOR;
10242 				/* NB: sorwakeup_locked() does an implicit unlock. */
10243 				sorwakeup_locked(so);
10244 			}
10245 		}
10246 		if ((tp->t_flags & TF_SACK_PERMIT) &&
10247 		    (save_tlen > 0) &&
10248 		    TCPS_HAVEESTABLISHED(tp->t_state)) {
10249 			if ((tlen == 0) && (SEQ_LT(save_start, save_rnxt))) {
10250 				/*
10251 				 * DSACK actually handled in the fastpath
10252 				 * above.
10253 				 */
10254 				RACK_OPTS_INC(tcp_sack_path_1);
10255 				tcp_update_sack_list(tp, save_start,
10256 				    save_start + save_tlen);
10257 			} else if ((tlen > 0) && SEQ_GT(tp->rcv_nxt, save_rnxt)) {
10258 				if ((tp->rcv_numsacks >= 1) &&
10259 				    (tp->sackblks[0].end == save_start)) {
10260 					/*
10261 					 * Partial overlap, recorded at todrop
10262 					 * above.
10263 					 */
10264 					RACK_OPTS_INC(tcp_sack_path_2a);
10265 					tcp_update_sack_list(tp,
10266 					    tp->sackblks[0].start,
10267 					    tp->sackblks[0].end);
10268 				} else {
10269 					RACK_OPTS_INC(tcp_sack_path_2b);
10270 					tcp_update_dsack_list(tp, save_start,
10271 					    save_start + save_tlen);
10272 				}
10273 			} else if (tlen >= save_tlen) {
10274 				/* Update of sackblks. */
10275 				RACK_OPTS_INC(tcp_sack_path_3);
10276 				tcp_update_dsack_list(tp, save_start,
10277 				    save_start + save_tlen);
10278 			} else if (tlen > 0) {
10279 				RACK_OPTS_INC(tcp_sack_path_4);
10280 				tcp_update_dsack_list(tp, save_start,
10281 				    save_start + tlen);
10282 			}
10283 		}
10284 	} else {
10285 		m_freem(m);
10286 		thflags &= ~TH_FIN;
10287 	}
10288 
10289 	/*
10290 	 * If FIN is received ACK the FIN and let the user know that the
10291 	 * connection is closing.
10292 	 */
10293 	if (thflags & TH_FIN) {
10294 		if (TCPS_HAVERCVDFIN(tp->t_state) == 0) {
10295 			/* The socket upcall is handled by socantrcvmore. */
10296 			socantrcvmore(so);
10297 			/*
10298 			 * If connection is half-synchronized (ie NEEDSYN
10299 			 * flag on) then delay ACK, so it may be piggybacked
10300 			 * when SYN is sent. Otherwise, since we received a
10301 			 * FIN then no more input can be expected, send ACK
10302 			 * now.
10303 			 */
10304 			if (tp->t_flags & TF_NEEDSYN) {
10305 				rack_timer_cancel(tp, rack,
10306 				    rack->r_ctl.rc_rcvtime, __LINE__);
10307 				tp->t_flags |= TF_DELACK;
10308 			} else {
10309 				tp->t_flags |= TF_ACKNOW;
10310 			}
10311 			tp->rcv_nxt++;
10312 		}
10313 		switch (tp->t_state) {
10314 			/*
10315 			 * In SYN_RECEIVED and ESTABLISHED STATES enter the
10316 			 * CLOSE_WAIT state.
10317 			 */
10318 		case TCPS_SYN_RECEIVED:
10319 			tp->t_starttime = ticks;
10320 			/* FALLTHROUGH */
10321 		case TCPS_ESTABLISHED:
10322 			rack_timer_cancel(tp, rack,
10323 			    rack->r_ctl.rc_rcvtime, __LINE__);
10324 			tcp_state_change(tp, TCPS_CLOSE_WAIT);
10325 			break;
10326 
10327 			/*
10328 			 * If still in FIN_WAIT_1 STATE FIN has not been
10329 			 * acked so enter the CLOSING state.
10330 			 */
10331 		case TCPS_FIN_WAIT_1:
10332 			rack_timer_cancel(tp, rack,
10333 			    rack->r_ctl.rc_rcvtime, __LINE__);
10334 			tcp_state_change(tp, TCPS_CLOSING);
10335 			break;
10336 
10337 			/*
10338 			 * In FIN_WAIT_2 state enter the TIME_WAIT state,
10339 			 * starting the time-wait timer, turning off the
10340 			 * other standard timers.
10341 			 */
10342 		case TCPS_FIN_WAIT_2:
10343 			rack_timer_cancel(tp, rack,
10344 			    rack->r_ctl.rc_rcvtime, __LINE__);
10345 			tcp_twstart(tp);
10346 			return (1);
10347 		}
10348 	}
10349 	/*
10350 	 * Return any desired output.
10351 	 */
10352 	if ((tp->t_flags & TF_ACKNOW) ||
10353 	    (sbavail(&so->so_snd) > (tp->snd_max - tp->snd_una))) {
10354 		rack->r_wanted_output = 1;
10355 	}
10356 	INP_WLOCK_ASSERT(tp->t_inpcb);
10357 	return (0);
10358 }
10359 
10360 /*
10361  * Here nothing is really faster, its just that we
10362  * have broken out the fast-data path also just like
10363  * the fast-ack.
10364  */
10365 static int
10366 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th, struct socket *so,
10367     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
10368     uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos)
10369 {
10370 	int32_t nsegs;
10371 	int32_t newsize = 0;	/* automatic sockbuf scaling */
10372 	struct tcp_rack *rack;
10373 #ifdef NETFLIX_SB_LIMITS
10374 	u_int mcnt, appended;
10375 #endif
10376 #ifdef TCPDEBUG
10377 	/*
10378 	 * The size of tcp_saveipgen must be the size of the max ip header,
10379 	 * now IPv6.
10380 	 */
10381 	u_char tcp_saveipgen[IP6_HDR_LEN];
10382 	struct tcphdr tcp_savetcp;
10383 	short ostate = 0;
10384 
10385 #endif
10386 	/*
10387 	 * If last ACK falls within this segment's sequence numbers, record
10388 	 * the timestamp. NOTE that the test is modified according to the
10389 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
10390 	 */
10391 	if (__predict_false(th->th_seq != tp->rcv_nxt)) {
10392 		return (0);
10393 	}
10394 	if (__predict_false(tp->snd_nxt != tp->snd_max)) {
10395 		return (0);
10396 	}
10397 	if (tiwin && tiwin != tp->snd_wnd) {
10398 		return (0);
10399 	}
10400 	if (__predict_false((tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN)))) {
10401 		return (0);
10402 	}
10403 	if (__predict_false((to->to_flags & TOF_TS) &&
10404 	    (TSTMP_LT(to->to_tsval, tp->ts_recent)))) {
10405 		return (0);
10406 	}
10407 	if (__predict_false((th->th_ack != tp->snd_una))) {
10408 		return (0);
10409 	}
10410 	if (__predict_false(tlen > sbspace(&so->so_rcv))) {
10411 		return (0);
10412 	}
10413 	if ((to->to_flags & TOF_TS) != 0 &&
10414 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
10415 		tp->ts_recent_age = tcp_ts_getticks();
10416 		tp->ts_recent = to->to_tsval;
10417 	}
10418 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10419 	/*
10420 	 * This is a pure, in-sequence data packet with nothing on the
10421 	 * reassembly queue and we have enough buffer space to take it.
10422 	 */
10423 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
10424 
10425 #ifdef NETFLIX_SB_LIMITS
10426 	if (so->so_rcv.sb_shlim) {
10427 		mcnt = m_memcnt(m);
10428 		appended = 0;
10429 		if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
10430 		    CFO_NOSLEEP, NULL) == false) {
10431 			counter_u64_add(tcp_sb_shlim_fails, 1);
10432 			m_freem(m);
10433 			return (1);
10434 		}
10435 	}
10436 #endif
10437 	/* Clean receiver SACK report if present */
10438 	if (tp->rcv_numsacks)
10439 		tcp_clean_sackreport(tp);
10440 	KMOD_TCPSTAT_INC(tcps_preddat);
10441 	tp->rcv_nxt += tlen;
10442 	if (tlen &&
10443 	    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
10444 	    (tp->t_fbyte_in == 0)) {
10445 		tp->t_fbyte_in = ticks;
10446 		if (tp->t_fbyte_in == 0)
10447 			tp->t_fbyte_in = 1;
10448 		if (tp->t_fbyte_out && tp->t_fbyte_in)
10449 			tp->t_flags2 |= TF2_FBYTES_COMPLETE;
10450 	}
10451 	/*
10452 	 * Pull snd_wl1 up to prevent seq wrap relative to th_seq.
10453 	 */
10454 	tp->snd_wl1 = th->th_seq;
10455 	/*
10456 	 * Pull rcv_up up to prevent seq wrap relative to rcv_nxt.
10457 	 */
10458 	tp->rcv_up = tp->rcv_nxt;
10459 	KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
10460 	KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
10461 #ifdef TCPDEBUG
10462 	if (so->so_options & SO_DEBUG)
10463 		tcp_trace(TA_INPUT, ostate, tp,
10464 		    (void *)tcp_saveipgen, &tcp_savetcp, 0);
10465 #endif
10466 	newsize = tcp_autorcvbuf(m, th, so, tp, tlen);
10467 
10468 	/* Add data to socket buffer. */
10469 	SOCKBUF_LOCK(&so->so_rcv);
10470 	if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
10471 		m_freem(m);
10472 	} else {
10473 		/*
10474 		 * Set new socket buffer size. Give up when limit is
10475 		 * reached.
10476 		 */
10477 		if (newsize)
10478 			if (!sbreserve_locked(&so->so_rcv,
10479 			    newsize, so, NULL))
10480 				so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
10481 		m_adj(m, drop_hdrlen);	/* delayed header drop */
10482 #ifdef NETFLIX_SB_LIMITS
10483 		appended =
10484 #endif
10485 			sbappendstream_locked(&so->so_rcv, m, 0);
10486 		ctf_calc_rwin(so, tp);
10487 	}
10488 	rack_log_wakeup(tp,rack, &so->so_rcv, tlen, 1);
10489 	/* NB: sorwakeup_locked() does an implicit unlock. */
10490 	sorwakeup_locked(so);
10491 #ifdef NETFLIX_SB_LIMITS
10492 	if (so->so_rcv.sb_shlim && mcnt != appended)
10493 		counter_fo_release(so->so_rcv.sb_shlim, mcnt - appended);
10494 #endif
10495 	rack_handle_delayed_ack(tp, rack, tlen, 0);
10496 	if (tp->snd_una == tp->snd_max)
10497 		sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
10498 	return (1);
10499 }
10500 
10501 /*
10502  * This subfunction is used to try to highly optimize the
10503  * fast path. We again allow window updates that are
10504  * in sequence to remain in the fast-path. We also add
10505  * in the __predict's to attempt to help the compiler.
10506  * Note that if we return a 0, then we can *not* process
10507  * it and the caller should push the packet into the
10508  * slow-path.
10509  */
10510 static int
10511 rack_fastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
10512     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
10513     uint32_t tiwin, int32_t nxt_pkt, uint32_t cts)
10514 {
10515 	int32_t acked;
10516 	int32_t nsegs;
10517 #ifdef TCPDEBUG
10518 	/*
10519 	 * The size of tcp_saveipgen must be the size of the max ip header,
10520 	 * now IPv6.
10521 	 */
10522 	u_char tcp_saveipgen[IP6_HDR_LEN];
10523 	struct tcphdr tcp_savetcp;
10524 	short ostate = 0;
10525 #endif
10526 	int32_t under_pacing = 0;
10527 	struct tcp_rack *rack;
10528 
10529 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
10530 		/* Old ack, behind (or duplicate to) the last one rcv'd */
10531 		return (0);
10532 	}
10533 	if (__predict_false(SEQ_GT(th->th_ack, tp->snd_max))) {
10534 		/* Above what we have sent? */
10535 		return (0);
10536 	}
10537 	if (__predict_false(tp->snd_nxt != tp->snd_max)) {
10538 		/* We are retransmitting */
10539 		return (0);
10540 	}
10541 	if (__predict_false(tiwin == 0)) {
10542 		/* zero window */
10543 		return (0);
10544 	}
10545 	if (__predict_false(tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN))) {
10546 		/* We need a SYN or a FIN, unlikely.. */
10547 		return (0);
10548 	}
10549 	if ((to->to_flags & TOF_TS) && __predict_false(TSTMP_LT(to->to_tsval, tp->ts_recent))) {
10550 		/* Timestamp is behind .. old ack with seq wrap? */
10551 		return (0);
10552 	}
10553 	if (__predict_false(IN_RECOVERY(tp->t_flags))) {
10554 		/* Still recovering */
10555 		return (0);
10556 	}
10557 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10558 	if (rack->r_ctl.rc_sacked) {
10559 		/* We have sack holes on our scoreboard */
10560 		return (0);
10561 	}
10562 	/* Ok if we reach here, we can process a fast-ack */
10563 	if (rack->gp_ready &&
10564 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
10565 		under_pacing = 1;
10566 	}
10567 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
10568 	rack_log_ack(tp, to, th, 0, 0);
10569 	/* Did the window get updated? */
10570 	if (tiwin != tp->snd_wnd) {
10571 		tp->snd_wnd = tiwin;
10572 		rack_validate_fo_sendwin_up(tp, rack);
10573 		tp->snd_wl1 = th->th_seq;
10574 		if (tp->snd_wnd > tp->max_sndwnd)
10575 			tp->max_sndwnd = tp->snd_wnd;
10576 	}
10577 	/* Do we exit persists? */
10578 	if ((rack->rc_in_persist != 0) &&
10579 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
10580 			       rack->r_ctl.rc_pace_min_segs))) {
10581 		rack_exit_persist(tp, rack, cts);
10582 	}
10583 	/* Do we enter persists? */
10584 	if ((rack->rc_in_persist == 0) &&
10585 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
10586 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
10587 	    (tp->snd_max == tp->snd_una) &&
10588 	    sbavail(&tp->t_inpcb->inp_socket->so_snd) &&
10589 	    (sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) {
10590 		/*
10591 		 * Here the rwnd is less than
10592 		 * the pacing size, we are established,
10593 		 * nothing is outstanding, and there is
10594 		 * data to send. Enter persists.
10595 		 */
10596 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
10597 	}
10598 	/*
10599 	 * If last ACK falls within this segment's sequence numbers, record
10600 	 * the timestamp. NOTE that the test is modified according to the
10601 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
10602 	 */
10603 	if ((to->to_flags & TOF_TS) != 0 &&
10604 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
10605 		tp->ts_recent_age = tcp_ts_getticks();
10606 		tp->ts_recent = to->to_tsval;
10607 	}
10608 	/*
10609 	 * This is a pure ack for outstanding data.
10610 	 */
10611 	KMOD_TCPSTAT_INC(tcps_predack);
10612 
10613 	/*
10614 	 * "bad retransmit" recovery.
10615 	 */
10616 	if ((tp->t_flags & TF_PREVVALID) &&
10617 	    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
10618 		tp->t_flags &= ~TF_PREVVALID;
10619 		if (tp->t_rxtshift == 1 &&
10620 		    (int)(ticks - tp->t_badrxtwin) < 0)
10621 			rack_cong_signal(tp, CC_RTO_ERR, th->th_ack);
10622 	}
10623 	/*
10624 	 * Recalculate the transmit timer / rtt.
10625 	 *
10626 	 * Some boxes send broken timestamp replies during the SYN+ACK
10627 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
10628 	 * and blow up the retransmit timer.
10629 	 */
10630 	acked = BYTES_THIS_ACK(tp, th);
10631 
10632 #ifdef TCP_HHOOK
10633 	/* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */
10634 	hhook_run_tcp_est_in(tp, th, to);
10635 #endif
10636 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
10637 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
10638 	if (acked) {
10639 		struct mbuf *mfree;
10640 
10641 		rack_ack_received(tp, rack, th->th_ack, nsegs, CC_ACK, 0);
10642 		SOCKBUF_LOCK(&so->so_snd);
10643 		mfree = sbcut_locked(&so->so_snd, acked);
10644 		tp->snd_una = th->th_ack;
10645 		/* Note we want to hold the sb lock through the sendmap adjust */
10646 		rack_adjust_sendmap(rack, &so->so_snd, tp->snd_una);
10647 		/* Wake up the socket if we have room to write more */
10648 		rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
10649 		sowwakeup_locked(so);
10650 		m_freem(mfree);
10651 		tp->t_rxtshift = 0;
10652 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
10653 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
10654 		rack->rc_tlp_in_progress = 0;
10655 		rack->r_ctl.rc_tlp_cnt_out = 0;
10656 		/*
10657 		 * If it is the RXT timer we want to
10658 		 * stop it, so we can restart a TLP.
10659 		 */
10660 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
10661 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
10662 #ifdef NETFLIX_HTTP_LOGGING
10663 		tcp_http_check_for_comp(rack->rc_tp, th->th_ack);
10664 #endif
10665 	}
10666 	/*
10667 	 * Let the congestion control algorithm update congestion control
10668 	 * related information. This typically means increasing the
10669 	 * congestion window.
10670 	 */
10671 	if (tp->snd_wnd < ctf_outstanding(tp)) {
10672 		/* The peer collapsed the window */
10673 		rack_collapsed_window(rack);
10674 	} else if (rack->rc_has_collapsed)
10675 		rack_un_collapse_window(rack);
10676 
10677 	/*
10678 	 * Pull snd_wl2 up to prevent seq wrap relative to th_ack.
10679 	 */
10680 	tp->snd_wl2 = th->th_ack;
10681 	tp->t_dupacks = 0;
10682 	m_freem(m);
10683 	/* ND6_HINT(tp);	 *//* Some progress has been made. */
10684 
10685 	/*
10686 	 * If all outstanding data are acked, stop retransmit timer,
10687 	 * otherwise restart timer using current (possibly backed-off)
10688 	 * value. If process is waiting for space, wakeup/selwakeup/signal.
10689 	 * If data are ready to send, let tcp_output decide between more
10690 	 * output or persist.
10691 	 */
10692 #ifdef TCPDEBUG
10693 	if (so->so_options & SO_DEBUG)
10694 		tcp_trace(TA_INPUT, ostate, tp,
10695 		    (void *)tcp_saveipgen,
10696 		    &tcp_savetcp, 0);
10697 #endif
10698 	if (under_pacing &&
10699 	    (rack->use_fixed_rate == 0) &&
10700 	    (rack->in_probe_rtt == 0) &&
10701 	    rack->rc_gp_dyn_mul &&
10702 	    rack->rc_always_pace) {
10703 		/* Check if we are dragging bottom */
10704 		rack_check_bottom_drag(tp, rack, so, acked);
10705 	}
10706 	if (tp->snd_una == tp->snd_max) {
10707 		tp->t_flags &= ~TF_PREVVALID;
10708 		rack->r_ctl.retran_during_recovery = 0;
10709 		rack->r_ctl.dsack_byte_cnt = 0;
10710 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
10711 		if (rack->r_ctl.rc_went_idle_time == 0)
10712 			rack->r_ctl.rc_went_idle_time = 1;
10713 		rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
10714 		if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0)
10715 			tp->t_acktime = 0;
10716 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
10717 	}
10718 	if (acked && rack->r_fast_output)
10719 		rack_gain_for_fastoutput(rack, tp, so, (uint32_t)acked);
10720 	if (sbavail(&so->so_snd)) {
10721 		rack->r_wanted_output = 1;
10722 	}
10723 	return (1);
10724 }
10725 
10726 /*
10727  * Return value of 1, the TCB is unlocked and most
10728  * likely gone, return value of 0, the TCP is still
10729  * locked.
10730  */
10731 static int
10732 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th, struct socket *so,
10733     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
10734     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
10735 {
10736 	int32_t ret_val = 0;
10737 	int32_t todrop;
10738 	int32_t ourfinisacked = 0;
10739 	struct tcp_rack *rack;
10740 
10741 	ctf_calc_rwin(so, tp);
10742 	/*
10743 	 * If the state is SYN_SENT: if seg contains an ACK, but not for our
10744 	 * SYN, drop the input. if seg contains a RST, then drop the
10745 	 * connection. if seg does not contain SYN, then drop it. Otherwise
10746 	 * this is an acceptable SYN segment initialize tp->rcv_nxt and
10747 	 * tp->irs if seg contains ack then advance tp->snd_una if seg
10748 	 * contains an ECE and ECN support is enabled, the stream is ECN
10749 	 * capable. if SYN has been acked change to ESTABLISHED else
10750 	 * SYN_RCVD state arrange for segment to be acked (eventually)
10751 	 * continue processing rest of data/controls.
10752 	 */
10753 	if ((thflags & TH_ACK) &&
10754 	    (SEQ_LEQ(th->th_ack, tp->iss) ||
10755 	    SEQ_GT(th->th_ack, tp->snd_max))) {
10756 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
10757 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
10758 		return (1);
10759 	}
10760 	if ((thflags & (TH_ACK | TH_RST)) == (TH_ACK | TH_RST)) {
10761 		TCP_PROBE5(connect__refused, NULL, tp,
10762 		    mtod(m, const char *), tp, th);
10763 		tp = tcp_drop(tp, ECONNREFUSED);
10764 		ctf_do_drop(m, tp);
10765 		return (1);
10766 	}
10767 	if (thflags & TH_RST) {
10768 		ctf_do_drop(m, tp);
10769 		return (1);
10770 	}
10771 	if (!(thflags & TH_SYN)) {
10772 		ctf_do_drop(m, tp);
10773 		return (1);
10774 	}
10775 	tp->irs = th->th_seq;
10776 	tcp_rcvseqinit(tp);
10777 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10778 	if (thflags & TH_ACK) {
10779 		int tfo_partial = 0;
10780 
10781 		KMOD_TCPSTAT_INC(tcps_connects);
10782 		soisconnected(so);
10783 #ifdef MAC
10784 		mac_socketpeer_set_from_mbuf(m, so);
10785 #endif
10786 		/* Do window scaling on this connection? */
10787 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
10788 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
10789 			tp->rcv_scale = tp->request_r_scale;
10790 		}
10791 		tp->rcv_adv += min(tp->rcv_wnd,
10792 		    TCP_MAXWIN << tp->rcv_scale);
10793 		/*
10794 		 * If not all the data that was sent in the TFO SYN
10795 		 * has been acked, resend the remainder right away.
10796 		 */
10797 		if (IS_FASTOPEN(tp->t_flags) &&
10798 		    (tp->snd_una != tp->snd_max)) {
10799 			tp->snd_nxt = th->th_ack;
10800 			tfo_partial = 1;
10801 		}
10802 		/*
10803 		 * If there's data, delay ACK; if there's also a FIN ACKNOW
10804 		 * will be turned on later.
10805 		 */
10806 		if (DELAY_ACK(tp, tlen) && tlen != 0 && !tfo_partial) {
10807 			rack_timer_cancel(tp, rack,
10808 					  rack->r_ctl.rc_rcvtime, __LINE__);
10809 			tp->t_flags |= TF_DELACK;
10810 		} else {
10811 			rack->r_wanted_output = 1;
10812 			tp->t_flags |= TF_ACKNOW;
10813 			rack->rc_dack_toggle = 0;
10814 		}
10815 		if (((thflags & (TH_CWR | TH_ECE)) == TH_ECE) &&
10816 		    (V_tcp_do_ecn == 1)) {
10817 			tp->t_flags2 |= TF2_ECN_PERMIT;
10818 			KMOD_TCPSTAT_INC(tcps_ecn_shs);
10819 		}
10820 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
10821 			/*
10822 			 * We advance snd_una for the
10823 			 * fast open case. If th_ack is
10824 			 * acknowledging data beyond
10825 			 * snd_una we can't just call
10826 			 * ack-processing since the
10827 			 * data stream in our send-map
10828 			 * will start at snd_una + 1 (one
10829 			 * beyond the SYN). If its just
10830 			 * equal we don't need to do that
10831 			 * and there is no send_map.
10832 			 */
10833 			tp->snd_una++;
10834 		}
10835 		/*
10836 		 * Received <SYN,ACK> in SYN_SENT[*] state. Transitions:
10837 		 * SYN_SENT  --> ESTABLISHED SYN_SENT* --> FIN_WAIT_1
10838 		 */
10839 		tp->t_starttime = ticks;
10840 		if (tp->t_flags & TF_NEEDFIN) {
10841 			tcp_state_change(tp, TCPS_FIN_WAIT_1);
10842 			tp->t_flags &= ~TF_NEEDFIN;
10843 			thflags &= ~TH_SYN;
10844 		} else {
10845 			tcp_state_change(tp, TCPS_ESTABLISHED);
10846 			TCP_PROBE5(connect__established, NULL, tp,
10847 			    mtod(m, const char *), tp, th);
10848 			rack_cc_conn_init(tp);
10849 		}
10850 	} else {
10851 		/*
10852 		 * Received initial SYN in SYN-SENT[*] state => simultaneous
10853 		 * open.  If segment contains CC option and there is a
10854 		 * cached CC, apply TAO test. If it succeeds, connection is *
10855 		 * half-synchronized. Otherwise, do 3-way handshake:
10856 		 * SYN-SENT -> SYN-RECEIVED SYN-SENT* -> SYN-RECEIVED* If
10857 		 * there was no CC option, clear cached CC value.
10858 		 */
10859 		tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN);
10860 		tcp_state_change(tp, TCPS_SYN_RECEIVED);
10861 	}
10862 	INP_WLOCK_ASSERT(tp->t_inpcb);
10863 	/*
10864 	 * Advance th->th_seq to correspond to first data byte. If data,
10865 	 * trim to stay within window, dropping FIN if necessary.
10866 	 */
10867 	th->th_seq++;
10868 	if (tlen > tp->rcv_wnd) {
10869 		todrop = tlen - tp->rcv_wnd;
10870 		m_adj(m, -todrop);
10871 		tlen = tp->rcv_wnd;
10872 		thflags &= ~TH_FIN;
10873 		KMOD_TCPSTAT_INC(tcps_rcvpackafterwin);
10874 		KMOD_TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop);
10875 	}
10876 	tp->snd_wl1 = th->th_seq - 1;
10877 	tp->rcv_up = th->th_seq;
10878 	/*
10879 	 * Client side of transaction: already sent SYN and data. If the
10880 	 * remote host used T/TCP to validate the SYN, our data will be
10881 	 * ACK'd; if so, enter normal data segment processing in the middle
10882 	 * of step 5, ack processing. Otherwise, goto step 6.
10883 	 */
10884 	if (thflags & TH_ACK) {
10885 		/* For syn-sent we need to possibly update the rtt */
10886 		if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
10887 			uint32_t t, mcts;
10888 
10889 			mcts = tcp_ts_getticks();
10890 			t = (mcts - to->to_tsecr) * HPTS_USEC_IN_MSEC;
10891 			if (!tp->t_rttlow || tp->t_rttlow > t)
10892 				tp->t_rttlow = t;
10893 			rack_log_rtt_sample_calc(rack, t, (to->to_tsecr * 1000), (mcts * 1000), 4);
10894 			tcp_rack_xmit_timer(rack, t + 1, 1, t, 0, NULL, 2);
10895 			tcp_rack_xmit_timer_commit(rack, tp);
10896 		}
10897 		if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val))
10898 			return (ret_val);
10899 		/* We may have changed to FIN_WAIT_1 above */
10900 		if (tp->t_state == TCPS_FIN_WAIT_1) {
10901 			/*
10902 			 * In FIN_WAIT_1 STATE in addition to the processing
10903 			 * for the ESTABLISHED state if our FIN is now
10904 			 * acknowledged then enter FIN_WAIT_2.
10905 			 */
10906 			if (ourfinisacked) {
10907 				/*
10908 				 * If we can't receive any more data, then
10909 				 * closing user can proceed. Starting the
10910 				 * timer is contrary to the specification,
10911 				 * but if we don't get a FIN we'll hang
10912 				 * forever.
10913 				 *
10914 				 * XXXjl: we should release the tp also, and
10915 				 * use a compressed state.
10916 				 */
10917 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
10918 					soisdisconnected(so);
10919 					tcp_timer_activate(tp, TT_2MSL,
10920 					    (tcp_fast_finwait2_recycle ?
10921 					    tcp_finwait2_timeout :
10922 					    TP_MAXIDLE(tp)));
10923 				}
10924 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
10925 			}
10926 		}
10927 	}
10928 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
10929 	   tiwin, thflags, nxt_pkt));
10930 }
10931 
10932 /*
10933  * Return value of 1, the TCB is unlocked and most
10934  * likely gone, return value of 0, the TCP is still
10935  * locked.
10936  */
10937 static int
10938 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
10939     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
10940     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
10941 {
10942 	struct tcp_rack *rack;
10943 	int32_t ret_val = 0;
10944 	int32_t ourfinisacked = 0;
10945 
10946 	ctf_calc_rwin(so, tp);
10947 	if ((thflags & TH_ACK) &&
10948 	    (SEQ_LEQ(th->th_ack, tp->snd_una) ||
10949 	    SEQ_GT(th->th_ack, tp->snd_max))) {
10950 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
10951 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
10952 		return (1);
10953 	}
10954 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10955 	if (IS_FASTOPEN(tp->t_flags)) {
10956 		/*
10957 		 * When a TFO connection is in SYN_RECEIVED, the
10958 		 * only valid packets are the initial SYN, a
10959 		 * retransmit/copy of the initial SYN (possibly with
10960 		 * a subset of the original data), a valid ACK, a
10961 		 * FIN, or a RST.
10962 		 */
10963 		if ((thflags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
10964 			tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
10965 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
10966 			return (1);
10967 		} else if (thflags & TH_SYN) {
10968 			/* non-initial SYN is ignored */
10969 			if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT) ||
10970 			    (rack->r_ctl.rc_hpts_flags & PACE_TMR_TLP) ||
10971 			    (rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK)) {
10972 				ctf_do_drop(m, NULL);
10973 				return (0);
10974 			}
10975 		} else if (!(thflags & (TH_ACK | TH_FIN | TH_RST))) {
10976 			ctf_do_drop(m, NULL);
10977 			return (0);
10978 		}
10979 	}
10980 	if ((thflags & TH_RST) ||
10981 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
10982 		return (ctf_process_rst(m, th, so, tp));
10983 	/*
10984 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
10985 	 * it's less than ts_recent, drop it.
10986 	 */
10987 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
10988 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
10989 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
10990 			return (ret_val);
10991 	}
10992 	/*
10993 	 * In the SYN-RECEIVED state, validate that the packet belongs to
10994 	 * this connection before trimming the data to fit the receive
10995 	 * window.  Check the sequence number versus IRS since we know the
10996 	 * sequence numbers haven't wrapped.  This is a partial fix for the
10997 	 * "LAND" DoS attack.
10998 	 */
10999 	if (SEQ_LT(th->th_seq, tp->irs)) {
11000 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11001 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11002 		return (1);
11003 	}
11004 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11005 			      &rack->r_ctl.challenge_ack_ts,
11006 			      &rack->r_ctl.challenge_ack_cnt)) {
11007 		return (ret_val);
11008 	}
11009 	/*
11010 	 * If last ACK falls within this segment's sequence numbers, record
11011 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11012 	 * from the latest proposal of the tcplw@cray.com list (Braden
11013 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11014 	 * with our earlier PAWS tests, so this check should be solely
11015 	 * predicated on the sequence space of this segment. 3) That we
11016 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11017 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11018 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11019 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11020 	 * p.869. In such cases, we can still calculate the RTT correctly
11021 	 * when RCV.NXT == Last.ACK.Sent.
11022 	 */
11023 	if ((to->to_flags & TOF_TS) != 0 &&
11024 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11025 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11026 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11027 		tp->ts_recent_age = tcp_ts_getticks();
11028 		tp->ts_recent = to->to_tsval;
11029 	}
11030 	tp->snd_wnd = tiwin;
11031 	rack_validate_fo_sendwin_up(tp, rack);
11032 	/*
11033 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11034 	 * is on (half-synchronized state), then queue data for later
11035 	 * processing; else drop segment and return.
11036 	 */
11037 	if ((thflags & TH_ACK) == 0) {
11038 		if (IS_FASTOPEN(tp->t_flags)) {
11039 			rack_cc_conn_init(tp);
11040 		}
11041 		return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11042 		    tiwin, thflags, nxt_pkt));
11043 	}
11044 	KMOD_TCPSTAT_INC(tcps_connects);
11045 	soisconnected(so);
11046 	/* Do window scaling? */
11047 	if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
11048 	    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
11049 		tp->rcv_scale = tp->request_r_scale;
11050 	}
11051 	/*
11052 	 * Make transitions: SYN-RECEIVED  -> ESTABLISHED SYN-RECEIVED* ->
11053 	 * FIN-WAIT-1
11054 	 */
11055 	tp->t_starttime = ticks;
11056 	if (IS_FASTOPEN(tp->t_flags) && tp->t_tfo_pending) {
11057 		tcp_fastopen_decrement_counter(tp->t_tfo_pending);
11058 		tp->t_tfo_pending = NULL;
11059 	}
11060 	if (tp->t_flags & TF_NEEDFIN) {
11061 		tcp_state_change(tp, TCPS_FIN_WAIT_1);
11062 		tp->t_flags &= ~TF_NEEDFIN;
11063 	} else {
11064 		tcp_state_change(tp, TCPS_ESTABLISHED);
11065 		TCP_PROBE5(accept__established, NULL, tp,
11066 		    mtod(m, const char *), tp, th);
11067 		/*
11068 		 * TFO connections call cc_conn_init() during SYN
11069 		 * processing.  Calling it again here for such connections
11070 		 * is not harmless as it would undo the snd_cwnd reduction
11071 		 * that occurs when a TFO SYN|ACK is retransmitted.
11072 		 */
11073 		if (!IS_FASTOPEN(tp->t_flags))
11074 			rack_cc_conn_init(tp);
11075 	}
11076 	/*
11077 	 * Account for the ACK of our SYN prior to
11078 	 * regular ACK processing below, except for
11079 	 * simultaneous SYN, which is handled later.
11080 	 */
11081 	if (SEQ_GT(th->th_ack, tp->snd_una) && !(tp->t_flags & TF_NEEDSYN))
11082 		tp->snd_una++;
11083 	/*
11084 	 * If segment contains data or ACK, will call tcp_reass() later; if
11085 	 * not, do so now to pass queued data to user.
11086 	 */
11087 	if (tlen == 0 && (thflags & TH_FIN) == 0) {
11088 		(void) tcp_reass(tp, (struct tcphdr *)0, NULL, 0,
11089 		    (struct mbuf *)0);
11090 		if (tp->t_flags & TF_WAKESOR) {
11091 			tp->t_flags &= ~TF_WAKESOR;
11092 			/* NB: sorwakeup_locked() does an implicit unlock. */
11093 			sorwakeup_locked(so);
11094 		}
11095 	}
11096 	tp->snd_wl1 = th->th_seq - 1;
11097 	/* For syn-recv we need to possibly update the rtt */
11098 	if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
11099 		uint32_t t, mcts;
11100 
11101 		mcts = tcp_ts_getticks();
11102 		t = (mcts - to->to_tsecr) * HPTS_USEC_IN_MSEC;
11103 		if (!tp->t_rttlow || tp->t_rttlow > t)
11104 			tp->t_rttlow = t;
11105 		rack_log_rtt_sample_calc(rack, t, (to->to_tsecr * 1000), (mcts * 1000), 5);
11106 		tcp_rack_xmit_timer(rack, t + 1, 1, t, 0, NULL, 2);
11107 		tcp_rack_xmit_timer_commit(rack, tp);
11108 	}
11109 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
11110 		return (ret_val);
11111 	}
11112 	if (tp->t_state == TCPS_FIN_WAIT_1) {
11113 		/* We could have went to FIN_WAIT_1 (or EST) above */
11114 		/*
11115 		 * In FIN_WAIT_1 STATE in addition to the processing for the
11116 		 * ESTABLISHED state if our FIN is now acknowledged then
11117 		 * enter FIN_WAIT_2.
11118 		 */
11119 		if (ourfinisacked) {
11120 			/*
11121 			 * If we can't receive any more data, then closing
11122 			 * user can proceed. Starting the timer is contrary
11123 			 * to the specification, but if we don't get a FIN
11124 			 * we'll hang forever.
11125 			 *
11126 			 * XXXjl: we should release the tp also, and use a
11127 			 * compressed state.
11128 			 */
11129 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
11130 				soisdisconnected(so);
11131 				tcp_timer_activate(tp, TT_2MSL,
11132 				    (tcp_fast_finwait2_recycle ?
11133 				    tcp_finwait2_timeout :
11134 				    TP_MAXIDLE(tp)));
11135 			}
11136 			tcp_state_change(tp, TCPS_FIN_WAIT_2);
11137 		}
11138 	}
11139 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11140 	    tiwin, thflags, nxt_pkt));
11141 }
11142 
11143 /*
11144  * Return value of 1, the TCB is unlocked and most
11145  * likely gone, return value of 0, the TCP is still
11146  * locked.
11147  */
11148 static int
11149 rack_do_established(struct mbuf *m, struct tcphdr *th, struct socket *so,
11150     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11151     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11152 {
11153 	int32_t ret_val = 0;
11154 	struct tcp_rack *rack;
11155 
11156 	/*
11157 	 * Header prediction: check for the two common cases of a
11158 	 * uni-directional data xfer.  If the packet has no control flags,
11159 	 * is in-sequence, the window didn't change and we're not
11160 	 * retransmitting, it's a candidate.  If the length is zero and the
11161 	 * ack moved forward, we're the sender side of the xfer.  Just free
11162 	 * the data acked & wake any higher level process that was blocked
11163 	 * waiting for space.  If the length is non-zero and the ack didn't
11164 	 * move, we're the receiver side.  If we're getting packets in-order
11165 	 * (the reassembly queue is empty), add the data toc The socket
11166 	 * buffer and note that we need a delayed ack. Make sure that the
11167 	 * hidden state-flags are also off. Since we check for
11168 	 * TCPS_ESTABLISHED first, it can only be TH_NEEDSYN.
11169 	 */
11170 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11171 	if (__predict_true(((to->to_flags & TOF_SACK) == 0)) &&
11172 	    __predict_true((thflags & (TH_SYN | TH_FIN | TH_RST | TH_ACK)) == TH_ACK) &&
11173 	    __predict_true(SEGQ_EMPTY(tp)) &&
11174 	    __predict_true(th->th_seq == tp->rcv_nxt)) {
11175 		if (tlen == 0) {
11176 			if (rack_fastack(m, th, so, tp, to, drop_hdrlen, tlen,
11177 			    tiwin, nxt_pkt, rack->r_ctl.rc_rcvtime)) {
11178 				return (0);
11179 			}
11180 		} else {
11181 			if (rack_do_fastnewdata(m, th, so, tp, to, drop_hdrlen, tlen,
11182 			    tiwin, nxt_pkt, iptos)) {
11183 				return (0);
11184 			}
11185 		}
11186 	}
11187 	ctf_calc_rwin(so, tp);
11188 
11189 	if ((thflags & TH_RST) ||
11190 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11191 		return (ctf_process_rst(m, th, so, tp));
11192 
11193 	/*
11194 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11195 	 * synchronized state.
11196 	 */
11197 	if (thflags & TH_SYN) {
11198 		ctf_challenge_ack(m, th, tp, &ret_val);
11199 		return (ret_val);
11200 	}
11201 	/*
11202 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11203 	 * it's less than ts_recent, drop it.
11204 	 */
11205 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11206 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11207 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11208 			return (ret_val);
11209 	}
11210 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11211 			      &rack->r_ctl.challenge_ack_ts,
11212 			      &rack->r_ctl.challenge_ack_cnt)) {
11213 		return (ret_val);
11214 	}
11215 	/*
11216 	 * If last ACK falls within this segment's sequence numbers, record
11217 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11218 	 * from the latest proposal of the tcplw@cray.com list (Braden
11219 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11220 	 * with our earlier PAWS tests, so this check should be solely
11221 	 * predicated on the sequence space of this segment. 3) That we
11222 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11223 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11224 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11225 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11226 	 * p.869. In such cases, we can still calculate the RTT correctly
11227 	 * when RCV.NXT == Last.ACK.Sent.
11228 	 */
11229 	if ((to->to_flags & TOF_TS) != 0 &&
11230 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11231 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11232 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11233 		tp->ts_recent_age = tcp_ts_getticks();
11234 		tp->ts_recent = to->to_tsval;
11235 	}
11236 	/*
11237 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11238 	 * is on (half-synchronized state), then queue data for later
11239 	 * processing; else drop segment and return.
11240 	 */
11241 	if ((thflags & TH_ACK) == 0) {
11242 		if (tp->t_flags & TF_NEEDSYN) {
11243 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11244 			    tiwin, thflags, nxt_pkt));
11245 
11246 		} else if (tp->t_flags & TF_ACKNOW) {
11247 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
11248 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
11249 			return (ret_val);
11250 		} else {
11251 			ctf_do_drop(m, NULL);
11252 			return (0);
11253 		}
11254 	}
11255 	/*
11256 	 * Ack processing.
11257 	 */
11258 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
11259 		return (ret_val);
11260 	}
11261 	if (sbavail(&so->so_snd)) {
11262 		if (ctf_progress_timeout_check(tp, true)) {
11263 			rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
11264 			tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
11265 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11266 			return (1);
11267 		}
11268 	}
11269 	/* State changes only happen in rack_process_data() */
11270 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11271 	    tiwin, thflags, nxt_pkt));
11272 }
11273 
11274 /*
11275  * Return value of 1, the TCB is unlocked and most
11276  * likely gone, return value of 0, the TCP is still
11277  * locked.
11278  */
11279 static int
11280 rack_do_close_wait(struct mbuf *m, struct tcphdr *th, struct socket *so,
11281     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11282     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11283 {
11284 	int32_t ret_val = 0;
11285 	struct tcp_rack *rack;
11286 
11287 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11288 	ctf_calc_rwin(so, tp);
11289 	if ((thflags & TH_RST) ||
11290 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11291 		return (ctf_process_rst(m, th, so, tp));
11292 	/*
11293 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11294 	 * synchronized state.
11295 	 */
11296 	if (thflags & TH_SYN) {
11297 		ctf_challenge_ack(m, th, tp, &ret_val);
11298 		return (ret_val);
11299 	}
11300 	/*
11301 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11302 	 * it's less than ts_recent, drop it.
11303 	 */
11304 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11305 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11306 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11307 			return (ret_val);
11308 	}
11309 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11310 			      &rack->r_ctl.challenge_ack_ts,
11311 			      &rack->r_ctl.challenge_ack_cnt)) {
11312 		return (ret_val);
11313 	}
11314 	/*
11315 	 * If last ACK falls within this segment's sequence numbers, record
11316 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11317 	 * from the latest proposal of the tcplw@cray.com list (Braden
11318 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11319 	 * with our earlier PAWS tests, so this check should be solely
11320 	 * predicated on the sequence space of this segment. 3) That we
11321 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11322 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11323 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11324 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11325 	 * p.869. In such cases, we can still calculate the RTT correctly
11326 	 * when RCV.NXT == Last.ACK.Sent.
11327 	 */
11328 	if ((to->to_flags & TOF_TS) != 0 &&
11329 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11330 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11331 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11332 		tp->ts_recent_age = tcp_ts_getticks();
11333 		tp->ts_recent = to->to_tsval;
11334 	}
11335 	/*
11336 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11337 	 * is on (half-synchronized state), then queue data for later
11338 	 * processing; else drop segment and return.
11339 	 */
11340 	if ((thflags & TH_ACK) == 0) {
11341 		if (tp->t_flags & TF_NEEDSYN) {
11342 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11343 			    tiwin, thflags, nxt_pkt));
11344 
11345 		} else if (tp->t_flags & TF_ACKNOW) {
11346 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
11347 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
11348 			return (ret_val);
11349 		} else {
11350 			ctf_do_drop(m, NULL);
11351 			return (0);
11352 		}
11353 	}
11354 	/*
11355 	 * Ack processing.
11356 	 */
11357 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
11358 		return (ret_val);
11359 	}
11360 	if (sbavail(&so->so_snd)) {
11361 		if (ctf_progress_timeout_check(tp, true)) {
11362 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
11363 						tp, tick, PROGRESS_DROP, __LINE__);
11364 			tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
11365 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11366 			return (1);
11367 		}
11368 	}
11369 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11370 	    tiwin, thflags, nxt_pkt));
11371 }
11372 
11373 static int
11374 rack_check_data_after_close(struct mbuf *m,
11375     struct tcpcb *tp, int32_t *tlen, struct tcphdr *th, struct socket *so)
11376 {
11377 	struct tcp_rack *rack;
11378 
11379 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11380 	if (rack->rc_allow_data_af_clo == 0) {
11381 	close_now:
11382 		tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
11383 		/* tcp_close will kill the inp pre-log the Reset */
11384 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
11385 		tp = tcp_close(tp);
11386 		KMOD_TCPSTAT_INC(tcps_rcvafterclose);
11387 		ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, (*tlen));
11388 		return (1);
11389 	}
11390 	if (sbavail(&so->so_snd) == 0)
11391 		goto close_now;
11392 	/* Ok we allow data that is ignored and a followup reset */
11393 	tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
11394 	tp->rcv_nxt = th->th_seq + *tlen;
11395 	tp->t_flags2 |= TF2_DROP_AF_DATA;
11396 	rack->r_wanted_output = 1;
11397 	*tlen = 0;
11398 	return (0);
11399 }
11400 
11401 /*
11402  * Return value of 1, the TCB is unlocked and most
11403  * likely gone, return value of 0, the TCP is still
11404  * locked.
11405  */
11406 static int
11407 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, struct socket *so,
11408     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11409     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11410 {
11411 	int32_t ret_val = 0;
11412 	int32_t ourfinisacked = 0;
11413 	struct tcp_rack *rack;
11414 
11415 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11416 	ctf_calc_rwin(so, tp);
11417 
11418 	if ((thflags & TH_RST) ||
11419 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11420 		return (ctf_process_rst(m, th, so, tp));
11421 	/*
11422 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11423 	 * synchronized state.
11424 	 */
11425 	if (thflags & TH_SYN) {
11426 		ctf_challenge_ack(m, th, tp, &ret_val);
11427 		return (ret_val);
11428 	}
11429 	/*
11430 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11431 	 * it's less than ts_recent, drop it.
11432 	 */
11433 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11434 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11435 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11436 			return (ret_val);
11437 	}
11438 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11439 			      &rack->r_ctl.challenge_ack_ts,
11440 			      &rack->r_ctl.challenge_ack_cnt)) {
11441 		return (ret_val);
11442 	}
11443 	/*
11444 	 * If new data are received on a connection after the user processes
11445 	 * are gone, then RST the other end.
11446 	 */
11447 	if ((so->so_state & SS_NOFDREF) && tlen) {
11448 		if (rack_check_data_after_close(m, tp, &tlen, th, so))
11449 			return (1);
11450 	}
11451 	/*
11452 	 * If last ACK falls within this segment's sequence numbers, record
11453 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11454 	 * from the latest proposal of the tcplw@cray.com list (Braden
11455 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11456 	 * with our earlier PAWS tests, so this check should be solely
11457 	 * predicated on the sequence space of this segment. 3) That we
11458 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11459 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11460 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11461 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11462 	 * p.869. In such cases, we can still calculate the RTT correctly
11463 	 * when RCV.NXT == Last.ACK.Sent.
11464 	 */
11465 	if ((to->to_flags & TOF_TS) != 0 &&
11466 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11467 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11468 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11469 		tp->ts_recent_age = tcp_ts_getticks();
11470 		tp->ts_recent = to->to_tsval;
11471 	}
11472 	/*
11473 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11474 	 * is on (half-synchronized state), then queue data for later
11475 	 * processing; else drop segment and return.
11476 	 */
11477 	if ((thflags & TH_ACK) == 0) {
11478 		if (tp->t_flags & TF_NEEDSYN) {
11479 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11480 			    tiwin, thflags, nxt_pkt));
11481 		} else if (tp->t_flags & TF_ACKNOW) {
11482 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
11483 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
11484 			return (ret_val);
11485 		} else {
11486 			ctf_do_drop(m, NULL);
11487 			return (0);
11488 		}
11489 	}
11490 	/*
11491 	 * Ack processing.
11492 	 */
11493 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
11494 		return (ret_val);
11495 	}
11496 	if (ourfinisacked) {
11497 		/*
11498 		 * If we can't receive any more data, then closing user can
11499 		 * proceed. Starting the timer is contrary to the
11500 		 * specification, but if we don't get a FIN we'll hang
11501 		 * forever.
11502 		 *
11503 		 * XXXjl: we should release the tp also, and use a
11504 		 * compressed state.
11505 		 */
11506 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
11507 			soisdisconnected(so);
11508 			tcp_timer_activate(tp, TT_2MSL,
11509 			    (tcp_fast_finwait2_recycle ?
11510 			    tcp_finwait2_timeout :
11511 			    TP_MAXIDLE(tp)));
11512 		}
11513 		tcp_state_change(tp, TCPS_FIN_WAIT_2);
11514 	}
11515 	if (sbavail(&so->so_snd)) {
11516 		if (ctf_progress_timeout_check(tp, true)) {
11517 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
11518 						tp, tick, PROGRESS_DROP, __LINE__);
11519 			tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
11520 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11521 			return (1);
11522 		}
11523 	}
11524 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11525 	    tiwin, thflags, nxt_pkt));
11526 }
11527 
11528 /*
11529  * Return value of 1, the TCB is unlocked and most
11530  * likely gone, return value of 0, the TCP is still
11531  * locked.
11532  */
11533 static int
11534 rack_do_closing(struct mbuf *m, struct tcphdr *th, struct socket *so,
11535     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11536     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11537 {
11538 	int32_t ret_val = 0;
11539 	int32_t ourfinisacked = 0;
11540 	struct tcp_rack *rack;
11541 
11542 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11543 	ctf_calc_rwin(so, tp);
11544 
11545 	if ((thflags & TH_RST) ||
11546 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11547 		return (ctf_process_rst(m, th, so, tp));
11548 	/*
11549 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11550 	 * synchronized state.
11551 	 */
11552 	if (thflags & TH_SYN) {
11553 		ctf_challenge_ack(m, th, tp, &ret_val);
11554 		return (ret_val);
11555 	}
11556 	/*
11557 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11558 	 * it's less than ts_recent, drop it.
11559 	 */
11560 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11561 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11562 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11563 			return (ret_val);
11564 	}
11565 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11566 			      &rack->r_ctl.challenge_ack_ts,
11567 			      &rack->r_ctl.challenge_ack_cnt)) {
11568 		return (ret_val);
11569 	}
11570 	/*
11571 	 * If new data are received on a connection after the user processes
11572 	 * are gone, then RST the other end.
11573 	 */
11574 	if ((so->so_state & SS_NOFDREF) && tlen) {
11575 		if (rack_check_data_after_close(m, tp, &tlen, th, so))
11576 			return (1);
11577 	}
11578 	/*
11579 	 * If last ACK falls within this segment's sequence numbers, record
11580 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11581 	 * from the latest proposal of the tcplw@cray.com list (Braden
11582 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11583 	 * with our earlier PAWS tests, so this check should be solely
11584 	 * predicated on the sequence space of this segment. 3) That we
11585 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11586 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11587 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11588 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11589 	 * p.869. In such cases, we can still calculate the RTT correctly
11590 	 * when RCV.NXT == Last.ACK.Sent.
11591 	 */
11592 	if ((to->to_flags & TOF_TS) != 0 &&
11593 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11594 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11595 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11596 		tp->ts_recent_age = tcp_ts_getticks();
11597 		tp->ts_recent = to->to_tsval;
11598 	}
11599 	/*
11600 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11601 	 * is on (half-synchronized state), then queue data for later
11602 	 * processing; else drop segment and return.
11603 	 */
11604 	if ((thflags & TH_ACK) == 0) {
11605 		if (tp->t_flags & TF_NEEDSYN) {
11606 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11607 			    tiwin, thflags, nxt_pkt));
11608 		} else if (tp->t_flags & TF_ACKNOW) {
11609 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
11610 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
11611 			return (ret_val);
11612 		} else {
11613 			ctf_do_drop(m, NULL);
11614 			return (0);
11615 		}
11616 	}
11617 	/*
11618 	 * Ack processing.
11619 	 */
11620 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
11621 		return (ret_val);
11622 	}
11623 	if (ourfinisacked) {
11624 		tcp_twstart(tp);
11625 		m_freem(m);
11626 		return (1);
11627 	}
11628 	if (sbavail(&so->so_snd)) {
11629 		if (ctf_progress_timeout_check(tp, true)) {
11630 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
11631 						tp, tick, PROGRESS_DROP, __LINE__);
11632 			tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
11633 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11634 			return (1);
11635 		}
11636 	}
11637 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11638 	    tiwin, thflags, nxt_pkt));
11639 }
11640 
11641 /*
11642  * Return value of 1, the TCB is unlocked and most
11643  * likely gone, return value of 0, the TCP is still
11644  * locked.
11645  */
11646 static int
11647 rack_do_lastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
11648     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11649     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11650 {
11651 	int32_t ret_val = 0;
11652 	int32_t ourfinisacked = 0;
11653 	struct tcp_rack *rack;
11654 
11655 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11656 	ctf_calc_rwin(so, tp);
11657 
11658 	if ((thflags & TH_RST) ||
11659 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11660 		return (ctf_process_rst(m, th, so, tp));
11661 	/*
11662 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11663 	 * synchronized state.
11664 	 */
11665 	if (thflags & TH_SYN) {
11666 		ctf_challenge_ack(m, th, tp, &ret_val);
11667 		return (ret_val);
11668 	}
11669 	/*
11670 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11671 	 * it's less than ts_recent, drop it.
11672 	 */
11673 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11674 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11675 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11676 			return (ret_val);
11677 	}
11678 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11679 			      &rack->r_ctl.challenge_ack_ts,
11680 			      &rack->r_ctl.challenge_ack_cnt)) {
11681 		return (ret_val);
11682 	}
11683 	/*
11684 	 * If new data are received on a connection after the user processes
11685 	 * are gone, then RST the other end.
11686 	 */
11687 	if ((so->so_state & SS_NOFDREF) && tlen) {
11688 		if (rack_check_data_after_close(m, tp, &tlen, th, so))
11689 			return (1);
11690 	}
11691 	/*
11692 	 * If last ACK falls within this segment's sequence numbers, record
11693 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11694 	 * from the latest proposal of the tcplw@cray.com list (Braden
11695 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11696 	 * with our earlier PAWS tests, so this check should be solely
11697 	 * predicated on the sequence space of this segment. 3) That we
11698 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11699 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11700 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11701 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11702 	 * p.869. In such cases, we can still calculate the RTT correctly
11703 	 * when RCV.NXT == Last.ACK.Sent.
11704 	 */
11705 	if ((to->to_flags & TOF_TS) != 0 &&
11706 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11707 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11708 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11709 		tp->ts_recent_age = tcp_ts_getticks();
11710 		tp->ts_recent = to->to_tsval;
11711 	}
11712 	/*
11713 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11714 	 * is on (half-synchronized state), then queue data for later
11715 	 * processing; else drop segment and return.
11716 	 */
11717 	if ((thflags & TH_ACK) == 0) {
11718 		if (tp->t_flags & TF_NEEDSYN) {
11719 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11720 			    tiwin, thflags, nxt_pkt));
11721 		} else if (tp->t_flags & TF_ACKNOW) {
11722 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
11723 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
11724 			return (ret_val);
11725 		} else {
11726 			ctf_do_drop(m, NULL);
11727 			return (0);
11728 		}
11729 	}
11730 	/*
11731 	 * case TCPS_LAST_ACK: Ack processing.
11732 	 */
11733 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
11734 		return (ret_val);
11735 	}
11736 	if (ourfinisacked) {
11737 		tp = tcp_close(tp);
11738 		ctf_do_drop(m, tp);
11739 		return (1);
11740 	}
11741 	if (sbavail(&so->so_snd)) {
11742 		if (ctf_progress_timeout_check(tp, true)) {
11743 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
11744 						tp, tick, PROGRESS_DROP, __LINE__);
11745 			tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
11746 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11747 			return (1);
11748 		}
11749 	}
11750 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11751 	    tiwin, thflags, nxt_pkt));
11752 }
11753 
11754 /*
11755  * Return value of 1, the TCB is unlocked and most
11756  * likely gone, return value of 0, the TCP is still
11757  * locked.
11758  */
11759 static int
11760 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, struct socket *so,
11761     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11762     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11763 {
11764 	int32_t ret_val = 0;
11765 	int32_t ourfinisacked = 0;
11766 	struct tcp_rack *rack;
11767 
11768 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11769 	ctf_calc_rwin(so, tp);
11770 
11771 	/* Reset receive buffer auto scaling when not in bulk receive mode. */
11772 	if ((thflags & TH_RST) ||
11773 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11774 		return (ctf_process_rst(m, th, so, tp));
11775 	/*
11776 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11777 	 * synchronized state.
11778 	 */
11779 	if (thflags & TH_SYN) {
11780 		ctf_challenge_ack(m, th, tp, &ret_val);
11781 		return (ret_val);
11782 	}
11783 	/*
11784 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11785 	 * it's less than ts_recent, drop it.
11786 	 */
11787 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11788 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11789 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11790 			return (ret_val);
11791 	}
11792 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11793 			      &rack->r_ctl.challenge_ack_ts,
11794 			      &rack->r_ctl.challenge_ack_cnt)) {
11795 		return (ret_val);
11796 	}
11797 	/*
11798 	 * If new data are received on a connection after the user processes
11799 	 * are gone, then RST the other end.
11800 	 */
11801 	if ((so->so_state & SS_NOFDREF) &&
11802 	    tlen) {
11803 		if (rack_check_data_after_close(m, tp, &tlen, th, so))
11804 			return (1);
11805 	}
11806 	/*
11807 	 * If last ACK falls within this segment's sequence numbers, record
11808 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11809 	 * from the latest proposal of the tcplw@cray.com list (Braden
11810 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11811 	 * with our earlier PAWS tests, so this check should be solely
11812 	 * predicated on the sequence space of this segment. 3) That we
11813 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11814 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11815 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11816 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11817 	 * p.869. In such cases, we can still calculate the RTT correctly
11818 	 * when RCV.NXT == Last.ACK.Sent.
11819 	 */
11820 	if ((to->to_flags & TOF_TS) != 0 &&
11821 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11822 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11823 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11824 		tp->ts_recent_age = tcp_ts_getticks();
11825 		tp->ts_recent = to->to_tsval;
11826 	}
11827 	/*
11828 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11829 	 * is on (half-synchronized state), then queue data for later
11830 	 * processing; else drop segment and return.
11831 	 */
11832 	if ((thflags & TH_ACK) == 0) {
11833 		if (tp->t_flags & TF_NEEDSYN) {
11834 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11835 			    tiwin, thflags, nxt_pkt));
11836 		} else if (tp->t_flags & TF_ACKNOW) {
11837 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
11838 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
11839 			return (ret_val);
11840 		} else {
11841 			ctf_do_drop(m, NULL);
11842 			return (0);
11843 		}
11844 	}
11845 	/*
11846 	 * Ack processing.
11847 	 */
11848 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
11849 		return (ret_val);
11850 	}
11851 	if (sbavail(&so->so_snd)) {
11852 		if (ctf_progress_timeout_check(tp, true)) {
11853 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
11854 						tp, tick, PROGRESS_DROP, __LINE__);
11855 			tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
11856 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11857 			return (1);
11858 		}
11859 	}
11860 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11861 	    tiwin, thflags, nxt_pkt));
11862 }
11863 
11864 static void inline
11865 rack_clear_rate_sample(struct tcp_rack *rack)
11866 {
11867 	rack->r_ctl.rack_rs.rs_flags = RACK_RTT_EMPTY;
11868 	rack->r_ctl.rack_rs.rs_rtt_cnt = 0;
11869 	rack->r_ctl.rack_rs.rs_rtt_tot = 0;
11870 }
11871 
11872 static void
11873 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line, uint64_t *fill_override)
11874 {
11875 	uint64_t bw_est, rate_wanted;
11876 	int chged = 0;
11877 	uint32_t user_max, orig_min, orig_max;
11878 
11879 	orig_min = rack->r_ctl.rc_pace_min_segs;
11880 	orig_max = rack->r_ctl.rc_pace_max_segs;
11881 	user_max = ctf_fixed_maxseg(tp) * rack->rc_user_set_max_segs;
11882 	if (ctf_fixed_maxseg(tp) != rack->r_ctl.rc_pace_min_segs)
11883 		chged = 1;
11884 	rack->r_ctl.rc_pace_min_segs = ctf_fixed_maxseg(tp);
11885 	if (rack->use_fixed_rate || rack->rc_force_max_seg) {
11886 		if (user_max != rack->r_ctl.rc_pace_max_segs)
11887 			chged = 1;
11888 	}
11889 	if (rack->rc_force_max_seg) {
11890 		rack->r_ctl.rc_pace_max_segs = user_max;
11891 	} else if (rack->use_fixed_rate) {
11892 		bw_est = rack_get_bw(rack);
11893 		if ((rack->r_ctl.crte == NULL) ||
11894 		    (bw_est != rack->r_ctl.crte->rate)) {
11895 			rack->r_ctl.rc_pace_max_segs = user_max;
11896 		} else {
11897 			/* We are pacing right at the hardware rate */
11898 			uint32_t segsiz;
11899 
11900 			segsiz = min(ctf_fixed_maxseg(tp),
11901 				     rack->r_ctl.rc_pace_min_segs);
11902 			rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(
11903 				                           tp, bw_est, segsiz, 0,
11904 							   rack->r_ctl.crte, NULL);
11905 		}
11906 	} else if (rack->rc_always_pace) {
11907 		if (rack->r_ctl.gp_bw ||
11908 #ifdef NETFLIX_PEAKRATE
11909 		    rack->rc_tp->t_maxpeakrate ||
11910 #endif
11911 		    rack->r_ctl.init_rate) {
11912 			/* We have a rate of some sort set */
11913 			uint32_t  orig;
11914 
11915 			bw_est = rack_get_bw(rack);
11916 			orig = rack->r_ctl.rc_pace_max_segs;
11917 			if (fill_override)
11918 				rate_wanted = *fill_override;
11919 			else
11920 				rate_wanted = rack_get_output_bw(rack, bw_est, NULL, NULL);
11921 			if (rate_wanted) {
11922 				/* We have something */
11923 				rack->r_ctl.rc_pace_max_segs = rack_get_pacing_len(rack,
11924 										   rate_wanted,
11925 										   ctf_fixed_maxseg(rack->rc_tp));
11926 			} else
11927 				rack->r_ctl.rc_pace_max_segs = rack->r_ctl.rc_pace_min_segs;
11928 			if (orig != rack->r_ctl.rc_pace_max_segs)
11929 				chged = 1;
11930 		} else if ((rack->r_ctl.gp_bw == 0) &&
11931 			   (rack->r_ctl.rc_pace_max_segs == 0)) {
11932 			/*
11933 			 * If we have nothing limit us to bursting
11934 			 * out IW sized pieces.
11935 			 */
11936 			chged = 1;
11937 			rack->r_ctl.rc_pace_max_segs = rc_init_window(rack);
11938 		}
11939 	}
11940 	if (rack->r_ctl.rc_pace_max_segs > PACE_MAX_IP_BYTES) {
11941 		chged = 1;
11942 		rack->r_ctl.rc_pace_max_segs = PACE_MAX_IP_BYTES;
11943 	}
11944 	if (chged)
11945 		rack_log_type_pacing_sizes(tp, rack, orig_min, orig_max, line, 2);
11946 }
11947 
11948 
11949 static void
11950 rack_init_fsb_block(struct tcpcb *tp, struct tcp_rack *rack)
11951 {
11952 #ifdef INET6
11953 	struct ip6_hdr *ip6 = NULL;
11954 #endif
11955 #ifdef INET
11956 	struct ip *ip = NULL;
11957 #endif
11958 	struct udphdr *udp = NULL;
11959 
11960 	/* Ok lets fill in the fast block, it can only be used with no IP options! */
11961 #ifdef INET6
11962 	if (rack->r_is_v6) {
11963 		rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
11964 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
11965 		if (tp->t_port) {
11966 			rack->r_ctl.fsb.tcp_ip_hdr_len += sizeof(struct udphdr);
11967 			udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
11968 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
11969 			udp->uh_dport = tp->t_port;
11970 			rack->r_ctl.fsb.udp = udp;
11971 			rack->r_ctl.fsb.th = (struct tcphdr *)(udp + 1);
11972 		} else
11973 		{
11974 			rack->r_ctl.fsb.th = (struct tcphdr *)(ip6 + 1);
11975 			rack->r_ctl.fsb.udp = NULL;
11976 		}
11977 		tcpip_fillheaders(rack->rc_inp,
11978 				  tp->t_port,
11979 				  ip6, rack->r_ctl.fsb.th);
11980 	} else
11981 #endif				/* INET6 */
11982 	{
11983 		rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct tcpiphdr);
11984 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
11985 		if (tp->t_port) {
11986 			rack->r_ctl.fsb.tcp_ip_hdr_len += sizeof(struct udphdr);
11987 			udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
11988 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
11989 			udp->uh_dport = tp->t_port;
11990 			rack->r_ctl.fsb.udp = udp;
11991 			rack->r_ctl.fsb.th = (struct tcphdr *)(udp + 1);
11992 		} else
11993 		{
11994 			rack->r_ctl.fsb.udp = NULL;
11995 			rack->r_ctl.fsb.th = (struct tcphdr *)(ip + 1);
11996 		}
11997 		tcpip_fillheaders(rack->rc_inp,
11998 				  tp->t_port,
11999 				  ip, rack->r_ctl.fsb.th);
12000 	}
12001 	rack->r_fsb_inited = 1;
12002 }
12003 
12004 static int
12005 rack_init_fsb(struct tcpcb *tp, struct tcp_rack *rack)
12006 {
12007 	/*
12008 	 * Allocate the larger of spaces V6 if available else just
12009 	 * V4 and include udphdr (overbook)
12010 	 */
12011 #ifdef INET6
12012 	rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + sizeof(struct udphdr);
12013 #else
12014 	rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct tcpiphdr) + sizeof(struct udphdr);
12015 #endif
12016 	rack->r_ctl.fsb.tcp_ip_hdr = malloc(rack->r_ctl.fsb.tcp_ip_hdr_len,
12017 					    M_TCPFSB, M_NOWAIT|M_ZERO);
12018 	if (rack->r_ctl.fsb.tcp_ip_hdr == NULL) {
12019 		return (ENOMEM);
12020 	}
12021 	rack->r_fsb_inited = 0;
12022 	return (0);
12023 }
12024 
12025 static int
12026 rack_init(struct tcpcb *tp)
12027 {
12028 	struct tcp_rack *rack = NULL;
12029 	struct rack_sendmap *insret;
12030 	uint32_t iwin, snt, us_cts;
12031 	int err;
12032 
12033 	tp->t_fb_ptr = uma_zalloc(rack_pcb_zone, M_NOWAIT);
12034 	if (tp->t_fb_ptr == NULL) {
12035 		/*
12036 		 * We need to allocate memory but cant. The INP and INP_INFO
12037 		 * locks and they are recusive (happens during setup. So a
12038 		 * scheme to drop the locks fails :(
12039 		 *
12040 		 */
12041 		return (ENOMEM);
12042 	}
12043 	memset(tp->t_fb_ptr, 0, sizeof(struct tcp_rack));
12044 
12045 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12046 	RB_INIT(&rack->r_ctl.rc_mtree);
12047 	TAILQ_INIT(&rack->r_ctl.rc_free);
12048 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
12049 	rack->rc_tp = tp;
12050 	rack->rc_inp = tp->t_inpcb;
12051 	/* Set the flag */
12052 	rack->r_is_v6 = (tp->t_inpcb->inp_vflag & INP_IPV6) != 0;
12053 	/* Probably not needed but lets be sure */
12054 	rack_clear_rate_sample(rack);
12055 	/*
12056 	 * Save off the default values, socket options will poke
12057 	 * at these if pacing is not on or we have not yet
12058 	 * reached where pacing is on (gp_ready/fixed enabled).
12059 	 * When they get set into the CC module (when gp_ready
12060 	 * is enabled or we enable fixed) then we will set these
12061 	 * values into the CC and place in here the old values
12062 	 * so we have a restoral. Then we will set the flag
12063 	 * rc_pacing_cc_set. That way whenever we turn off pacing
12064 	 * or switch off this stack, we will know to go restore
12065 	 * the saved values.
12066 	 */
12067 	rack->r_ctl.rc_saved_beta.beta = V_newreno_beta_ecn;
12068 	rack->r_ctl.rc_saved_beta.beta_ecn = V_newreno_beta_ecn;
12069 	/* We want abe like behavior as well */
12070 	rack->r_ctl.rc_saved_beta.newreno_flags = CC_NEWRENO_BETA_ECN;
12071 	rack->r_ctl.rc_reorder_fade = rack_reorder_fade;
12072 	rack->rc_allow_data_af_clo = rack_ignore_data_after_close;
12073 	rack->r_ctl.rc_tlp_threshold = rack_tlp_thresh;
12074 	if (use_rack_rr)
12075 		rack->use_rack_rr = 1;
12076 	if (V_tcp_delack_enabled)
12077 		tp->t_delayed_ack = 1;
12078 	else
12079 		tp->t_delayed_ack = 0;
12080 #ifdef TCP_ACCOUNTING
12081 	if (rack_tcp_accounting) {
12082 		tp->t_flags2 |= TF2_TCP_ACCOUNTING;
12083 	}
12084 #endif
12085 	if (rack_enable_shared_cwnd)
12086 		rack->rack_enable_scwnd = 1;
12087 	rack->rc_user_set_max_segs = rack_hptsi_segments;
12088 	rack->rc_force_max_seg = 0;
12089 	if (rack_use_imac_dack)
12090 		rack->rc_dack_mode = 1;
12091 	TAILQ_INIT(&rack->r_ctl.opt_list);
12092 	rack->r_ctl.rc_reorder_shift = rack_reorder_thresh;
12093 	rack->r_ctl.rc_pkt_delay = rack_pkt_delay;
12094 	rack->r_ctl.rc_tlp_cwnd_reduce = rack_lower_cwnd_at_tlp;
12095 	rack->r_ctl.rc_lowest_us_rtt = 0xffffffff;
12096 	rack->r_ctl.rc_highest_us_rtt = 0;
12097 	rack->r_ctl.bw_rate_cap = rack_bw_rate_cap;
12098 	rack->r_ctl.timer_slop = TICKS_2_USEC(tcp_rexmit_slop);
12099 	if (rack_use_cmp_acks)
12100 		rack->r_use_cmp_ack = 1;
12101 	if (rack_disable_prr)
12102 		rack->rack_no_prr = 1;
12103 	if (rack_gp_no_rec_chg)
12104 		rack->rc_gp_no_rec_chg = 1;
12105 	if (rack_pace_every_seg && tcp_can_enable_pacing()) {
12106 		rack->rc_always_pace = 1;
12107 		if (rack->use_fixed_rate || rack->gp_ready)
12108 			rack_set_cc_pacing(rack);
12109 	} else
12110 		rack->rc_always_pace = 0;
12111 	if (rack_enable_mqueue_for_nonpaced || rack->r_use_cmp_ack)
12112 		rack->r_mbuf_queue = 1;
12113 	else
12114 		rack->r_mbuf_queue = 0;
12115 	if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
12116 		tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
12117 	else
12118 		tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
12119 	rack_set_pace_segments(tp, rack, __LINE__, NULL);
12120 	if (rack_limits_scwnd)
12121 		rack->r_limit_scw = 1;
12122 	else
12123 		rack->r_limit_scw = 0;
12124 	rack->rc_labc = V_tcp_abc_l_var;
12125 	rack->r_ctl.rc_high_rwnd = tp->snd_wnd;
12126 	rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
12127 	rack->r_ctl.rc_rate_sample_method = rack_rate_sample_method;
12128 	rack->rack_tlp_threshold_use = rack_tlp_threshold_use;
12129 	rack->r_ctl.rc_prr_sendalot = rack_send_a_lot_in_prr;
12130 	rack->r_ctl.rc_min_to = rack_min_to;
12131 	microuptime(&rack->r_ctl.act_rcv_time);
12132 	rack->r_ctl.rc_last_time_decay = rack->r_ctl.act_rcv_time;
12133 	rack->r_running_late = 0;
12134 	rack->r_running_early = 0;
12135 	rack->rc_init_win = rack_default_init_window;
12136 	rack->r_ctl.rack_per_of_gp_ss = rack_per_of_gp_ss;
12137 	if (rack_hw_up_only)
12138 		rack->r_up_only = 1;
12139 	if (rack_do_dyn_mul) {
12140 		/* When dynamic adjustment is on CA needs to start at 100% */
12141 		rack->rc_gp_dyn_mul = 1;
12142 		if (rack_do_dyn_mul >= 100)
12143 			rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
12144 	} else
12145 		rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
12146 	rack->r_ctl.rack_per_of_gp_rec = rack_per_of_gp_rec;
12147 	rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
12148 	rack->r_ctl.rc_tlp_rxt_last_time = tcp_tv_to_mssectick(&rack->r_ctl.act_rcv_time);
12149 	setup_time_filter_small(&rack->r_ctl.rc_gp_min_rtt, FILTER_TYPE_MIN,
12150 				rack_probertt_filter_life);
12151 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
12152 	rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
12153 	rack->r_ctl.rc_time_of_last_probertt = us_cts;
12154 	rack->r_ctl.challenge_ack_ts = tcp_ts_getticks();
12155 	rack->r_ctl.rc_time_probertt_starts = 0;
12156 	/* We require at least one measurement, even if the sysctl is 0 */
12157 	if (rack_req_measurements)
12158 		rack->r_ctl.req_measurements = rack_req_measurements;
12159 	else
12160 		rack->r_ctl.req_measurements = 1;
12161 	if (rack_enable_hw_pacing)
12162 		rack->rack_hdw_pace_ena = 1;
12163 	if (rack_hw_rate_caps)
12164 		rack->r_rack_hw_rate_caps = 1;
12165 	/* Do we force on detection? */
12166 #ifdef NETFLIX_EXP_DETECTION
12167 	if (tcp_force_detection)
12168 		rack->do_detection = 1;
12169 	else
12170 #endif
12171 		rack->do_detection = 0;
12172 	if (rack_non_rxt_use_cr)
12173 		rack->rack_rec_nonrxt_use_cr = 1;
12174 	err = rack_init_fsb(tp, rack);
12175 	if (err) {
12176 		uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
12177 		tp->t_fb_ptr = NULL;
12178 		return (err);
12179 	}
12180 	if (tp->snd_una != tp->snd_max) {
12181 		/* Create a send map for the current outstanding data */
12182 		struct rack_sendmap *rsm;
12183 
12184 		rsm = rack_alloc(rack);
12185 		if (rsm == NULL) {
12186 			uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
12187 			tp->t_fb_ptr = NULL;
12188 			return (ENOMEM);
12189 		}
12190 		rsm->r_no_rtt_allowed = 1;
12191 		rsm->r_tim_lastsent[0] = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
12192 		rsm->r_rtr_cnt = 1;
12193 		rsm->r_rtr_bytes = 0;
12194 		if (tp->t_flags & TF_SENTFIN) {
12195 			rsm->r_end = tp->snd_max - 1;
12196 			rsm->r_flags |= RACK_HAS_FIN;
12197 		} else {
12198 			rsm->r_end = tp->snd_max;
12199 		}
12200 		if (tp->snd_una == tp->iss) {
12201 			/* The data space is one beyond snd_una */
12202 			rsm->r_flags |= RACK_HAS_SYN;
12203 			rsm->r_start = tp->iss;
12204 			rsm->r_end = rsm->r_start + (tp->snd_max - tp->snd_una);
12205 		} else
12206 			rsm->r_start = tp->snd_una;
12207 		rsm->r_dupack = 0;
12208 		if (rack->rc_inp->inp_socket->so_snd.sb_mb != NULL) {
12209 			rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd, 0, &rsm->soff);
12210 			if (rsm->m)
12211 				rsm->orig_m_len = rsm->m->m_len;
12212 			else
12213 				rsm->orig_m_len = 0;
12214 		} else {
12215 			/*
12216 			 * This can happen if we have a stand-alone FIN or
12217 			 *  SYN.
12218 			 */
12219 			rsm->m = NULL;
12220 			rsm->orig_m_len = 0;
12221 			rsm->soff = 0;
12222 		}
12223 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
12224 #ifdef INVARIANTS
12225 		if (insret != NULL) {
12226 			panic("Insert in rb tree fails ret:%p rack:%p rsm:%p",
12227 			      insret, rack, rsm);
12228 		}
12229 #endif
12230 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
12231 		rsm->r_in_tmap = 1;
12232 	}
12233 	/*
12234 	 * Timers in Rack are kept in microseconds so lets
12235 	 * convert any initial incoming variables
12236 	 * from ticks into usecs. Note that we
12237 	 * also change the values of t_srtt and t_rttvar, if
12238 	 * they are non-zero. They are kept with a 5
12239 	 * bit decimal so we have to carefully convert
12240 	 * these to get the full precision.
12241 	 */
12242 	rack_convert_rtts(tp);
12243 	tp->t_rttlow = TICKS_2_USEC(tp->t_rttlow);
12244 	if (rack_def_profile)
12245 		rack_set_profile(rack, rack_def_profile);
12246 	/* Cancel the GP measurement in progress */
12247 	tp->t_flags &= ~TF_GPUTINPROG;
12248 	if (SEQ_GT(tp->snd_max, tp->iss))
12249 		snt = tp->snd_max - tp->iss;
12250 	else
12251 		snt = 0;
12252 	iwin = rc_init_window(rack);
12253 	if (snt < iwin) {
12254 		/* We are not past the initial window
12255 		 * so we need to make sure cwnd is
12256 		 * correct.
12257 		 */
12258 		if (tp->snd_cwnd < iwin)
12259 			tp->snd_cwnd = iwin;
12260 		/*
12261 		 * If we are within the initial window
12262 		 * we want ssthresh to be unlimited. Setting
12263 		 * it to the rwnd (which the default stack does
12264 		 * and older racks) is not really a good idea
12265 		 * since we want to be in SS and grow both the
12266 		 * cwnd and the rwnd (via dynamic rwnd growth). If
12267 		 * we set it to the rwnd then as the peer grows its
12268 		 * rwnd we will be stuck in CA and never hit SS.
12269 		 *
12270 		 * Its far better to raise it up high (this takes the
12271 		 * risk that there as been a loss already, probably
12272 		 * we should have an indicator in all stacks of loss
12273 		 * but we don't), but considering the normal use this
12274 		 * is a risk worth taking. The consequences of not
12275 		 * hitting SS are far worse than going one more time
12276 		 * into it early on (before we have sent even a IW).
12277 		 * It is highly unlikely that we will have had a loss
12278 		 * before getting the IW out.
12279 		 */
12280 		tp->snd_ssthresh = 0xffffffff;
12281 	}
12282 	rack_stop_all_timers(tp);
12283 	/* Lets setup the fsb block */
12284 	rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
12285 	rack_log_rtt_shrinks(rack,  us_cts,  tp->t_rxtcur,
12286 			     __LINE__, RACK_RTTS_INIT);
12287 	return (0);
12288 }
12289 
12290 static int
12291 rack_handoff_ok(struct tcpcb *tp)
12292 {
12293 	if ((tp->t_state == TCPS_CLOSED) ||
12294 	    (tp->t_state == TCPS_LISTEN)) {
12295 		/* Sure no problem though it may not stick */
12296 		return (0);
12297 	}
12298 	if ((tp->t_state == TCPS_SYN_SENT) ||
12299 	    (tp->t_state == TCPS_SYN_RECEIVED)) {
12300 		/*
12301 		 * We really don't know if you support sack,
12302 		 * you have to get to ESTAB or beyond to tell.
12303 		 */
12304 		return (EAGAIN);
12305 	}
12306 	if ((tp->t_flags & TF_SENTFIN) && ((tp->snd_max - tp->snd_una) > 1)) {
12307 		/*
12308 		 * Rack will only send a FIN after all data is acknowledged.
12309 		 * So in this case we have more data outstanding. We can't
12310 		 * switch stacks until either all data and only the FIN
12311 		 * is left (in which case rack_init() now knows how
12312 		 * to deal with that) <or> all is acknowledged and we
12313 		 * are only left with incoming data, though why you
12314 		 * would want to switch to rack after all data is acknowledged
12315 		 * I have no idea (rrs)!
12316 		 */
12317 		return (EAGAIN);
12318 	}
12319 	if ((tp->t_flags & TF_SACK_PERMIT) || rack_sack_not_required){
12320 		return (0);
12321 	}
12322 	/*
12323 	 * If we reach here we don't do SACK on this connection so we can
12324 	 * never do rack.
12325 	 */
12326 	return (EINVAL);
12327 }
12328 
12329 
12330 static void
12331 rack_fini(struct tcpcb *tp, int32_t tcb_is_purged)
12332 {
12333 	int ack_cmp = 0;
12334 
12335 	if (tp->t_fb_ptr) {
12336 		struct tcp_rack *rack;
12337 		struct rack_sendmap *rsm, *nrsm, *rm;
12338 
12339 		rack = (struct tcp_rack *)tp->t_fb_ptr;
12340 		if (tp->t_in_pkt) {
12341 			/*
12342 			 * It is unsafe to process the packets since a
12343 			 * reset may be lurking in them (its rare but it
12344 			 * can occur). If we were to find a RST, then we
12345 			 * would end up dropping the connection and the
12346 			 * INP lock, so when we return the caller (tcp_usrreq)
12347 			 * will blow up when it trys to unlock the inp.
12348 			 */
12349 			struct mbuf *save, *m;
12350 
12351 			m = tp->t_in_pkt;
12352 			tp->t_in_pkt = NULL;
12353 			tp->t_tail_pkt = NULL;
12354 			while (m) {
12355 				save = m->m_nextpkt;
12356 				m->m_nextpkt = NULL;
12357 				m_freem(m);
12358 				m = save;
12359 			}
12360 			if ((tp->t_inpcb) &&
12361 			    (tp->t_inpcb->inp_flags2 & INP_MBUF_ACKCMP))
12362 				ack_cmp = 1;
12363 			if (ack_cmp) {
12364 				/* Total if we used large or small (if ack-cmp was used). */
12365 				if (rack->rc_inp->inp_flags2 & INP_MBUF_L_ACKS)
12366 					counter_u64_add(rack_large_ackcmp, 1);
12367 				else
12368 					counter_u64_add(rack_small_ackcmp, 1);
12369 			}
12370 		}
12371 		tp->t_flags &= ~TF_FORCEDATA;
12372 #ifdef NETFLIX_SHARED_CWND
12373 		if (rack->r_ctl.rc_scw) {
12374 			uint32_t limit;
12375 
12376 			if (rack->r_limit_scw)
12377 				limit = max(1, rack->r_ctl.rc_lowest_us_rtt);
12378 			else
12379 				limit = 0;
12380 			tcp_shared_cwnd_free_full(tp, rack->r_ctl.rc_scw,
12381 						  rack->r_ctl.rc_scw_index,
12382 						  limit);
12383 			rack->r_ctl.rc_scw = NULL;
12384 		}
12385 #endif
12386 		if (rack->r_ctl.fsb.tcp_ip_hdr) {
12387 			free(rack->r_ctl.fsb.tcp_ip_hdr, M_TCPFSB);
12388 			rack->r_ctl.fsb.tcp_ip_hdr = NULL;
12389 			rack->r_ctl.fsb.th = NULL;
12390 		}
12391 		/* Convert back to ticks, with  */
12392 		if (tp->t_srtt > 1) {
12393 			uint32_t val, frac;
12394 
12395 			val = USEC_2_TICKS(tp->t_srtt);
12396 			frac = tp->t_srtt % (HPTS_USEC_IN_SEC / hz);
12397 			tp->t_srtt = val << TCP_RTT_SHIFT;
12398 			/*
12399 			 * frac is the fractional part here is left
12400 			 * over from converting to hz and shifting.
12401 			 * We need to convert this to the 5 bit
12402 			 * remainder.
12403 			 */
12404 			if (frac) {
12405 				if (hz == 1000) {
12406 					frac = (((uint64_t)frac *  (uint64_t)TCP_RTT_SCALE) / (uint64_t)HPTS_USEC_IN_MSEC);
12407 				} else {
12408 					frac = (((uint64_t)frac * (uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE) /(uint64_t)HPTS_USEC_IN_SEC);
12409 				}
12410 				tp->t_srtt += frac;
12411 			}
12412 		}
12413 		if (tp->t_rttvar) {
12414 			uint32_t val, frac;
12415 
12416 			val = USEC_2_TICKS(tp->t_rttvar);
12417 			frac = tp->t_srtt % (HPTS_USEC_IN_SEC / hz);
12418 			tp->t_rttvar = val <<  TCP_RTTVAR_SHIFT;
12419 			/*
12420 			 * frac is the fractional part here is left
12421 			 * over from converting to hz and shifting.
12422 			 * We need to convert this to the 5 bit
12423 			 * remainder.
12424 			 */
12425 			if (frac) {
12426 				if (hz == 1000) {
12427 					frac = (((uint64_t)frac *  (uint64_t)TCP_RTT_SCALE) / (uint64_t)HPTS_USEC_IN_MSEC);
12428 				} else {
12429 					frac = (((uint64_t)frac * (uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE) /(uint64_t)HPTS_USEC_IN_SEC);
12430 				}
12431 				tp->t_rttvar += frac;
12432 			}
12433 		}
12434 		tp->t_rxtcur = USEC_2_TICKS(tp->t_rxtcur);
12435 		tp->t_rttlow = USEC_2_TICKS(tp->t_rttlow);
12436 		if (rack->rc_always_pace) {
12437 			tcp_decrement_paced_conn();
12438 			rack_undo_cc_pacing(rack);
12439 			rack->rc_always_pace = 0;
12440 		}
12441 		/* Clean up any options if they were not applied */
12442 		while (!TAILQ_EMPTY(&rack->r_ctl.opt_list)) {
12443 			struct deferred_opt_list *dol;
12444 
12445 			dol = TAILQ_FIRST(&rack->r_ctl.opt_list);
12446 			TAILQ_REMOVE(&rack->r_ctl.opt_list, dol, next);
12447 			free(dol, M_TCPDO);
12448 		}
12449 		/* rack does not use force data but other stacks may clear it */
12450 		if (rack->r_ctl.crte != NULL) {
12451 			tcp_rel_pacing_rate(rack->r_ctl.crte, tp);
12452 			rack->rack_hdrw_pacing = 0;
12453 			rack->r_ctl.crte = NULL;
12454 		}
12455 #ifdef TCP_BLACKBOX
12456 		tcp_log_flowend(tp);
12457 #endif
12458 		RB_FOREACH_SAFE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm) {
12459 			rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
12460 #ifdef INVARIANTS
12461 			if (rm != rsm) {
12462 				panic("At fini, rack:%p rsm:%p rm:%p",
12463 				      rack, rsm, rm);
12464 			}
12465 #endif
12466 			uma_zfree(rack_zone, rsm);
12467 		}
12468 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
12469 		while (rsm) {
12470 			TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
12471 			uma_zfree(rack_zone, rsm);
12472 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
12473 		}
12474 		rack->rc_free_cnt = 0;
12475 		uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
12476 		tp->t_fb_ptr = NULL;
12477 	}
12478 	if (tp->t_inpcb) {
12479 		tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
12480 		tp->t_inpcb->inp_flags2 &= ~INP_MBUF_QUEUE_READY;
12481 		tp->t_inpcb->inp_flags2 &= ~INP_DONT_SACK_QUEUE;
12482 		tp->t_inpcb->inp_flags2 &= ~INP_MBUF_ACKCMP;
12483 		/* Cancel the GP measurement in progress */
12484 		tp->t_flags &= ~TF_GPUTINPROG;
12485 		tp->t_inpcb->inp_flags2 &= ~INP_MBUF_L_ACKS;
12486 	}
12487 	/* Make sure snd_nxt is correctly set */
12488 	tp->snd_nxt = tp->snd_max;
12489 }
12490 
12491 static void
12492 rack_set_state(struct tcpcb *tp, struct tcp_rack *rack)
12493 {
12494 	switch (tp->t_state) {
12495 	case TCPS_SYN_SENT:
12496 		rack->r_state = TCPS_SYN_SENT;
12497 		rack->r_substate = rack_do_syn_sent;
12498 		break;
12499 	case TCPS_SYN_RECEIVED:
12500 		rack->r_state = TCPS_SYN_RECEIVED;
12501 		rack->r_substate = rack_do_syn_recv;
12502 		break;
12503 	case TCPS_ESTABLISHED:
12504 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
12505 		rack->r_state = TCPS_ESTABLISHED;
12506 		rack->r_substate = rack_do_established;
12507 		break;
12508 	case TCPS_CLOSE_WAIT:
12509 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
12510 		rack->r_state = TCPS_CLOSE_WAIT;
12511 		rack->r_substate = rack_do_close_wait;
12512 		break;
12513 	case TCPS_FIN_WAIT_1:
12514 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
12515 		rack->r_state = TCPS_FIN_WAIT_1;
12516 		rack->r_substate = rack_do_fin_wait_1;
12517 		break;
12518 	case TCPS_CLOSING:
12519 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
12520 		rack->r_state = TCPS_CLOSING;
12521 		rack->r_substate = rack_do_closing;
12522 		break;
12523 	case TCPS_LAST_ACK:
12524 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
12525 		rack->r_state = TCPS_LAST_ACK;
12526 		rack->r_substate = rack_do_lastack;
12527 		break;
12528 	case TCPS_FIN_WAIT_2:
12529 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
12530 		rack->r_state = TCPS_FIN_WAIT_2;
12531 		rack->r_substate = rack_do_fin_wait_2;
12532 		break;
12533 	case TCPS_LISTEN:
12534 	case TCPS_CLOSED:
12535 	case TCPS_TIME_WAIT:
12536 	default:
12537 		break;
12538 	};
12539 	if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
12540 		rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
12541 
12542 }
12543 
12544 static void
12545 rack_timer_audit(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb)
12546 {
12547 	/*
12548 	 * We received an ack, and then did not
12549 	 * call send or were bounced out due to the
12550 	 * hpts was running. Now a timer is up as well, is
12551 	 * it the right timer?
12552 	 */
12553 	struct rack_sendmap *rsm;
12554 	int tmr_up;
12555 
12556 	tmr_up = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
12557 	if (rack->rc_in_persist && (tmr_up == PACE_TMR_PERSIT))
12558 		return;
12559 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
12560 	if (((rsm == NULL) || (tp->t_state < TCPS_ESTABLISHED)) &&
12561 	    (tmr_up == PACE_TMR_RXT)) {
12562 		/* Should be an RXT */
12563 		return;
12564 	}
12565 	if (rsm == NULL) {
12566 		/* Nothing outstanding? */
12567 		if (tp->t_flags & TF_DELACK) {
12568 			if (tmr_up == PACE_TMR_DELACK)
12569 				/* We are supposed to have delayed ack up and we do */
12570 				return;
12571 		} else if (sbavail(&tp->t_inpcb->inp_socket->so_snd) && (tmr_up == PACE_TMR_RXT)) {
12572 			/*
12573 			 * if we hit enobufs then we would expect the possiblity
12574 			 * of nothing outstanding and the RXT up (and the hptsi timer).
12575 			 */
12576 			return;
12577 		} else if (((V_tcp_always_keepalive ||
12578 			     rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
12579 			    (tp->t_state <= TCPS_CLOSING)) &&
12580 			   (tmr_up == PACE_TMR_KEEP) &&
12581 			   (tp->snd_max == tp->snd_una)) {
12582 			/* We should have keep alive up and we do */
12583 			return;
12584 		}
12585 	}
12586 	if (SEQ_GT(tp->snd_max, tp->snd_una) &&
12587 		   ((tmr_up == PACE_TMR_TLP) ||
12588 		    (tmr_up == PACE_TMR_RACK) ||
12589 		    (tmr_up == PACE_TMR_RXT))) {
12590 		/*
12591 		 * Either a Rack, TLP or RXT is fine if  we
12592 		 * have outstanding data.
12593 		 */
12594 		return;
12595 	} else if (tmr_up == PACE_TMR_DELACK) {
12596 		/*
12597 		 * If the delayed ack was going to go off
12598 		 * before the rtx/tlp/rack timer were going to
12599 		 * expire, then that would be the timer in control.
12600 		 * Note we don't check the time here trusting the
12601 		 * code is correct.
12602 		 */
12603 		return;
12604 	}
12605 	/*
12606 	 * Ok the timer originally started is not what we want now.
12607 	 * We will force the hpts to be stopped if any, and restart
12608 	 * with the slot set to what was in the saved slot.
12609 	 */
12610 	if (rack->rc_inp->inp_in_hpts) {
12611 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
12612 			uint32_t us_cts;
12613 
12614 			us_cts = tcp_get_usecs(NULL);
12615 			if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
12616 				rack->r_early = 1;
12617 				rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
12618 			}
12619 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
12620 		}
12621 		tcp_hpts_remove(tp->t_inpcb, HPTS_REMOVE_OUTPUT);
12622 	}
12623 	rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
12624 	rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
12625 }
12626 
12627 
12628 static void
12629 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)
12630 {
12631 	tp->snd_wnd = tiwin;
12632 	rack_validate_fo_sendwin_up(tp, rack);
12633 	tp->snd_wl1 = seq;
12634 	tp->snd_wl2 = ack;
12635 	if (tp->snd_wnd > tp->max_sndwnd)
12636 		tp->max_sndwnd = tp->snd_wnd;
12637 	if (tp->snd_wnd < (tp->snd_max - high_seq)) {
12638 		/* The peer collapsed the window */
12639 		rack_collapsed_window(rack);
12640 	} else if (rack->rc_has_collapsed)
12641 		rack_un_collapse_window(rack);
12642 	/* Do we exit persists? */
12643 	if ((rack->rc_in_persist != 0) &&
12644 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
12645 				rack->r_ctl.rc_pace_min_segs))) {
12646 		rack_exit_persist(tp, rack, cts);
12647 	}
12648 	/* Do we enter persists? */
12649 	if ((rack->rc_in_persist == 0) &&
12650 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
12651 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
12652 	    (tp->snd_max == tp->snd_una) &&
12653 	    sbavail(&tp->t_inpcb->inp_socket->so_snd) &&
12654 	    (sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) {
12655 		/*
12656 		 * Here the rwnd is less than
12657 		 * the pacing size, we are established,
12658 		 * nothing is outstanding, and there is
12659 		 * data to send. Enter persists.
12660 		 */
12661 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
12662 	}
12663 }
12664 
12665 static void
12666 rack_log_input_packet(struct tcpcb *tp, struct tcp_rack *rack, struct tcp_ackent *ae, int ackval, uint32_t high_seq)
12667 {
12668 
12669 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
12670 		union tcp_log_stackspecific log;
12671 		struct timeval ltv;
12672 		char tcp_hdr_buf[60];
12673 		struct tcphdr *th;
12674 		struct timespec ts;
12675 		uint32_t orig_snd_una;
12676 		uint8_t xx = 0;
12677 
12678 #ifdef NETFLIX_HTTP_LOGGING
12679 		struct http_sendfile_track *http_req;
12680 
12681 		if (SEQ_GT(ae->ack, tp->snd_una)) {
12682 			http_req = tcp_http_find_req_for_seq(tp, (ae->ack-1));
12683 		} else {
12684 			http_req = tcp_http_find_req_for_seq(tp, ae->ack);
12685 		}
12686 #endif
12687 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
12688 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
12689 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
12690 		if (rack->rack_no_prr == 0)
12691 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
12692 		else
12693 			log.u_bbr.flex1 = 0;
12694 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
12695 		log.u_bbr.use_lt_bw <<= 1;
12696 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
12697 		log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
12698 		log.u_bbr.inflight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
12699 		log.u_bbr.pkts_out = tp->t_maxseg;
12700 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
12701 		log.u_bbr.flex7 = 1;
12702 		log.u_bbr.lost = ae->flags;
12703 		log.u_bbr.cwnd_gain = ackval;
12704 		log.u_bbr.pacing_gain = 0x2;
12705 		if (ae->flags & TSTMP_HDWR) {
12706 			/* Record the hardware timestamp if present */
12707 			log.u_bbr.flex3 = M_TSTMP;
12708 			ts.tv_sec = ae->timestamp / 1000000000;
12709 			ts.tv_nsec = ae->timestamp % 1000000000;
12710 			ltv.tv_sec = ts.tv_sec;
12711 			ltv.tv_usec = ts.tv_nsec / 1000;
12712 			log.u_bbr.lt_epoch = tcp_tv_to_usectick(&ltv);
12713 		} else if (ae->flags & TSTMP_LRO) {
12714 			/* Record the LRO the arrival timestamp */
12715 			log.u_bbr.flex3 = M_TSTMP_LRO;
12716 			ts.tv_sec = ae->timestamp / 1000000000;
12717 			ts.tv_nsec = ae->timestamp % 1000000000;
12718 			ltv.tv_sec = ts.tv_sec;
12719 			ltv.tv_usec = ts.tv_nsec / 1000;
12720 			log.u_bbr.flex5 = tcp_tv_to_usectick(&ltv);
12721 		}
12722 		log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
12723 		/* Log the rcv time */
12724 		log.u_bbr.delRate = ae->timestamp;
12725 #ifdef NETFLIX_HTTP_LOGGING
12726 		log.u_bbr.applimited = tp->t_http_closed;
12727 		log.u_bbr.applimited <<= 8;
12728 		log.u_bbr.applimited |= tp->t_http_open;
12729 		log.u_bbr.applimited <<= 8;
12730 		log.u_bbr.applimited |= tp->t_http_req;
12731 		if (http_req) {
12732 			/* Copy out any client req info */
12733 			/* seconds */
12734 			log.u_bbr.pkt_epoch = (http_req->localtime / HPTS_USEC_IN_SEC);
12735 			/* useconds */
12736 			log.u_bbr.delivered = (http_req->localtime % HPTS_USEC_IN_SEC);
12737 			log.u_bbr.rttProp = http_req->timestamp;
12738 			log.u_bbr.cur_del_rate = http_req->start;
12739 			if (http_req->flags & TCP_HTTP_TRACK_FLG_OPEN) {
12740 				log.u_bbr.flex8 |= 1;
12741 			} else {
12742 				log.u_bbr.flex8 |= 2;
12743 				log.u_bbr.bw_inuse = http_req->end;
12744 			}
12745 			log.u_bbr.flex6 = http_req->start_seq;
12746 			if (http_req->flags & TCP_HTTP_TRACK_FLG_COMP) {
12747 				log.u_bbr.flex8 |= 4;
12748 				log.u_bbr.epoch = http_req->end_seq;
12749 			}
12750 		}
12751 #endif
12752 		memset(tcp_hdr_buf, 0, sizeof(tcp_hdr_buf));
12753 		th = (struct tcphdr *)tcp_hdr_buf;
12754 		th->th_seq = ae->seq;
12755 		th->th_ack = ae->ack;
12756 		th->th_win = ae->win;
12757 		/* Now fill in the ports */
12758 		th->th_sport = tp->t_inpcb->inp_fport;
12759 		th->th_dport = tp->t_inpcb->inp_lport;
12760 		th->th_flags = ae->flags & 0xff;
12761 		/* Now do we have a timestamp option? */
12762 		if (ae->flags & HAS_TSTMP) {
12763 			u_char *cp;
12764 			uint32_t val;
12765 
12766 			th->th_off = ((sizeof(struct tcphdr) + TCPOLEN_TSTAMP_APPA) >> 2);
12767 			cp = (u_char *)(th + 1);
12768 			*cp = TCPOPT_NOP;
12769 			cp++;
12770 			*cp = TCPOPT_NOP;
12771 			cp++;
12772 			*cp = TCPOPT_TIMESTAMP;
12773 			cp++;
12774 			*cp = TCPOLEN_TIMESTAMP;
12775 			cp++;
12776 			val = htonl(ae->ts_value);
12777 			bcopy((char *)&val,
12778 			      (char *)cp, sizeof(uint32_t));
12779 			val = htonl(ae->ts_echo);
12780 			bcopy((char *)&val,
12781 			      (char *)(cp + 4), sizeof(uint32_t));
12782 		} else
12783 			th->th_off = (sizeof(struct tcphdr) >> 2);
12784 
12785 		/*
12786 		 * For sane logging we need to play a little trick.
12787 		 * If the ack were fully processed we would have moved
12788 		 * snd_una to high_seq, but since compressed acks are
12789 		 * processed in two phases, at this point (logging) snd_una
12790 		 * won't be advanced. So we would see multiple acks showing
12791 		 * the advancement. We can prevent that by "pretending" that
12792 		 * snd_una was advanced and then un-advancing it so that the
12793 		 * logging code has the right value for tlb_snd_una.
12794 		 */
12795 		if (tp->snd_una != high_seq) {
12796 			orig_snd_una = tp->snd_una;
12797 			tp->snd_una = high_seq;
12798 			xx = 1;
12799 		} else
12800 			xx = 0;
12801 		TCP_LOG_EVENTP(tp, th,
12802 			       &tp->t_inpcb->inp_socket->so_rcv,
12803 			       &tp->t_inpcb->inp_socket->so_snd, TCP_LOG_IN, 0,
12804 			       0, &log, true, &ltv);
12805 		if (xx) {
12806 			tp->snd_una = orig_snd_una;
12807 		}
12808 	}
12809 
12810 }
12811 
12812 static int
12813 rack_do_compressed_ack_processing(struct tcpcb *tp, struct socket *so, struct mbuf *m, int nxt_pkt, struct timeval *tv)
12814 {
12815 	/*
12816 	 * Handle a "special" compressed ack mbuf. Each incoming
12817 	 * ack has only four possible dispositions:
12818 	 *
12819 	 * A) It moves the cum-ack forward
12820 	 * B) It is behind the cum-ack.
12821 	 * C) It is a window-update ack.
12822 	 * D) It is a dup-ack.
12823 	 *
12824 	 * Note that we can have between 1 -> TCP_COMP_ACK_ENTRIES
12825 	 * in the incoming mbuf. We also need to still pay attention
12826 	 * to nxt_pkt since there may be another packet after this
12827 	 * one.
12828 	 */
12829 #ifdef TCP_ACCOUNTING
12830 	uint64_t ts_val;
12831 	uint64_t rdstc;
12832 #endif
12833 	int segsiz;
12834 	struct timespec ts;
12835 	struct tcp_rack *rack;
12836 	struct tcp_ackent *ae;
12837 	uint32_t tiwin, us_cts, cts, acked, acked_amount, high_seq, win_seq, the_win, win_upd_ack;
12838 	int cnt, i, did_out, ourfinisacked = 0;
12839 	int win_up_req = 0;
12840 	struct tcpopt to_holder, *to = NULL;
12841 	int nsegs = 0;
12842 	int under_pacing = 1;
12843 	int recovery = 0;
12844 	int idx;
12845 #ifdef TCP_ACCOUNTING
12846 	sched_pin();
12847 #endif
12848 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12849 	if (rack->gp_ready &&
12850 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT))
12851 		under_pacing = 0;
12852 	else
12853 		under_pacing = 1;
12854 
12855 	if (rack->r_state != tp->t_state)
12856 		rack_set_state(tp, rack);
12857 	to = &to_holder;
12858 	to->to_flags = 0;
12859 	KASSERT((m->m_len >= sizeof(struct tcp_ackent)),
12860 		("tp:%p m_cmpack:%p with invalid len:%u", tp, m, m->m_len));
12861 	cnt = m->m_len / sizeof(struct tcp_ackent);
12862 	idx = cnt / 5;
12863 	if (idx >= MAX_NUM_OF_CNTS)
12864 		idx = MAX_NUM_OF_CNTS - 1;
12865 	counter_u64_add(rack_proc_comp_ack[idx], 1);
12866 	counter_u64_add(rack_multi_single_eq, cnt);
12867 	high_seq = tp->snd_una;
12868 	the_win = tp->snd_wnd;
12869 	win_seq = tp->snd_wl1;
12870 	win_upd_ack = tp->snd_wl2;
12871 	cts = us_cts = tcp_tv_to_usectick(tv);
12872 	segsiz = ctf_fixed_maxseg(tp);
12873 	if ((rack->rc_gp_dyn_mul) &&
12874 	    (rack->use_fixed_rate == 0) &&
12875 	    (rack->rc_always_pace)) {
12876 		/* Check in on probertt */
12877 		rack_check_probe_rtt(rack, us_cts);
12878 	}
12879 	for (i = 0; i < cnt; i++) {
12880 #ifdef TCP_ACCOUNTING
12881 		ts_val = get_cyclecount();
12882 #endif
12883 		rack_clear_rate_sample(rack);
12884 		ae = ((mtod(m, struct tcp_ackent *)) + i);
12885 		/* Setup the window */
12886 		tiwin = ae->win << tp->snd_scale;
12887 		/* figure out the type of ack */
12888 		if (SEQ_LT(ae->ack, high_seq)) {
12889 			/* Case B*/
12890 			ae->ack_val_set = ACK_BEHIND;
12891 		} else if (SEQ_GT(ae->ack, high_seq)) {
12892 			/* Case A */
12893 			ae->ack_val_set = ACK_CUMACK;
12894 		} else if (tiwin == the_win) {
12895 			/* Case D */
12896 			ae->ack_val_set = ACK_DUPACK;
12897 		} else {
12898 			/* Case C */
12899 			ae->ack_val_set = ACK_RWND;
12900 		}
12901 		rack_log_input_packet(tp, rack, ae, ae->ack_val_set, high_seq);
12902 		/* Validate timestamp */
12903 		if (ae->flags & HAS_TSTMP) {
12904 			/* Setup for a timestamp */
12905 			to->to_flags = TOF_TS;
12906 			ae->ts_echo -= tp->ts_offset;
12907 			to->to_tsecr = ae->ts_echo;
12908 			to->to_tsval = ae->ts_value;
12909 			/*
12910 			 * If echoed timestamp is later than the current time, fall back to
12911 			 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
12912 			 * were used when this connection was established.
12913 			 */
12914 			if (TSTMP_GT(ae->ts_echo, cts))
12915 				ae->ts_echo = 0;
12916 			if (tp->ts_recent &&
12917 			    TSTMP_LT(ae->ts_value, tp->ts_recent)) {
12918 				if (ctf_ts_check_ac(tp, (ae->flags & 0xff))) {
12919 #ifdef TCP_ACCOUNTING
12920 					rdstc = get_cyclecount();
12921 					if (rdstc > ts_val) {
12922 						counter_u64_add(tcp_proc_time[ae->ack_val_set] ,
12923 								(rdstc - ts_val));
12924 						if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
12925 							tp->tcp_proc_time[ae->ack_val_set] += (rdstc - ts_val);
12926 						}
12927 					}
12928 #endif
12929 					continue;
12930 				}
12931 			}
12932 			if (SEQ_LEQ(ae->seq, tp->last_ack_sent) &&
12933 			    SEQ_LEQ(tp->last_ack_sent, ae->seq)) {
12934 				tp->ts_recent_age = tcp_ts_getticks();
12935 				tp->ts_recent = ae->ts_value;
12936 			}
12937 		} else {
12938 			/* Setup for a no options */
12939 			to->to_flags = 0;
12940 		}
12941 		/* Update the rcv time and perform idle reduction possibly */
12942 		if  (tp->t_idle_reduce &&
12943 		     (tp->snd_max == tp->snd_una) &&
12944 		     ((ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
12945 			counter_u64_add(rack_input_idle_reduces, 1);
12946 			rack_cc_after_idle(rack, tp);
12947 		}
12948 		tp->t_rcvtime = ticks;
12949 		/* Now what about ECN? */
12950 		if (tp->t_flags2 & TF2_ECN_PERMIT) {
12951 			if (ae->flags & TH_CWR) {
12952 				tp->t_flags2 &= ~TF2_ECN_SND_ECE;
12953 				tp->t_flags |= TF_ACKNOW;
12954 			}
12955 			switch (ae->codepoint & IPTOS_ECN_MASK) {
12956 			case IPTOS_ECN_CE:
12957 				tp->t_flags2 |= TF2_ECN_SND_ECE;
12958 				KMOD_TCPSTAT_INC(tcps_ecn_ce);
12959 				break;
12960 			case IPTOS_ECN_ECT0:
12961 				KMOD_TCPSTAT_INC(tcps_ecn_ect0);
12962 				break;
12963 			case IPTOS_ECN_ECT1:
12964 				KMOD_TCPSTAT_INC(tcps_ecn_ect1);
12965 				break;
12966 			}
12967 
12968 			/* Process a packet differently from RFC3168. */
12969 			cc_ecnpkt_handler_flags(tp, ae->flags, ae->codepoint);
12970 			/* Congestion experienced. */
12971 			if (ae->flags & TH_ECE) {
12972 				rack_cong_signal(tp,  CC_ECN, ae->ack);
12973 			}
12974 		}
12975 #ifdef TCP_ACCOUNTING
12976 		/* Count for the specific type of ack in */
12977 		counter_u64_add(tcp_cnt_counters[ae->ack_val_set], 1);
12978 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
12979 			tp->tcp_cnt_counters[ae->ack_val_set]++;
12980 		}
12981 #endif
12982 		/*
12983 		 * Note how we could move up these in the determination
12984 		 * above, but we don't so that way the timestamp checks (and ECN)
12985 		 * is done first before we do any processing on the ACK.
12986 		 * The non-compressed path through the code has this
12987 		 * weakness (noted by @jtl) that it actually does some
12988 		 * processing before verifying the timestamp information.
12989 		 * We don't take that path here which is why we set
12990 		 * the ack_val_set first, do the timestamp and ecn
12991 		 * processing, and then look at what we have setup.
12992 		 */
12993 		if (ae->ack_val_set == ACK_BEHIND) {
12994 			/*
12995 			 * Case B flag reordering, if window is not closed
12996 			 * or it could be a keep-alive or persists
12997 			 */
12998 			if (SEQ_LT(ae->ack, tp->snd_una) && (sbspace(&so->so_rcv) > segsiz)) {
12999 				counter_u64_add(rack_reorder_seen, 1);
13000 				rack->r_ctl.rc_reorder_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
13001 			}
13002 		} else if (ae->ack_val_set == ACK_DUPACK) {
13003 			/* Case D */
13004 
13005 			rack_strike_dupack(rack);
13006 		} else if (ae->ack_val_set == ACK_RWND) {
13007 			/* Case C */
13008 
13009 			win_up_req = 1;
13010 			win_upd_ack = ae->ack;
13011 			win_seq = ae->seq;
13012 			the_win = tiwin;
13013 		} else {
13014 			/* Case A */
13015 
13016 			if (SEQ_GT(ae->ack, tp->snd_max)) {
13017 				/*
13018 				 * We just send an ack since the incoming
13019 				 * ack is beyond the largest seq we sent.
13020 				 */
13021 				if ((tp->t_flags & TF_ACKNOW) == 0) {
13022 					ctf_ack_war_checks(tp, &rack->r_ctl.challenge_ack_ts, &rack->r_ctl.challenge_ack_cnt);
13023 					if (tp->t_flags && TF_ACKNOW)
13024 						rack->r_wanted_output = 1;
13025 				}
13026 			} else {
13027 				nsegs++;
13028 				/* If the window changed setup to update */
13029 				if (tiwin != tp->snd_wnd) {
13030 					win_up_req = 1;
13031 					win_upd_ack = ae->ack;
13032 					win_seq = ae->seq;
13033 					the_win = tiwin;
13034 				}
13035 #ifdef TCP_ACCOUNTING
13036 				/* Account for the acks */
13037 				if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13038 					tp->tcp_cnt_counters[CNT_OF_ACKS_IN] += (((ae->ack - high_seq) + segsiz - 1) / segsiz);
13039 				}
13040 				counter_u64_add(tcp_cnt_counters[CNT_OF_ACKS_IN],
13041 						(((ae->ack - high_seq) + segsiz - 1) / segsiz));
13042 #endif
13043 				high_seq = ae->ack;
13044 				/* Setup our act_rcv_time */
13045 				if ((ae->flags & TSTMP_LRO) || (ae->flags & TSTMP_HDWR)) {
13046 					ts.tv_sec = ae->timestamp / 1000000000;
13047 					ts.tv_nsec = ae->timestamp % 1000000000;
13048 					rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
13049 					rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
13050 				} else {
13051 					rack->r_ctl.act_rcv_time = *tv;
13052 				}
13053 				rack_process_to_cumack(tp, rack, ae->ack, cts, to);
13054 			}
13055 		}
13056 		/* And lets be sure to commit the rtt measurements for this ack */
13057 		tcp_rack_xmit_timer_commit(rack, tp);
13058 #ifdef TCP_ACCOUNTING
13059 		rdstc = get_cyclecount();
13060 		if (rdstc > ts_val) {
13061 			counter_u64_add(tcp_proc_time[ae->ack_val_set] , (rdstc - ts_val));
13062 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13063 				tp->tcp_proc_time[ae->ack_val_set] += (rdstc - ts_val);
13064 				if (ae->ack_val_set == ACK_CUMACK)
13065 					tp->tcp_proc_time[CYC_HANDLE_MAP] += (rdstc - ts_val);
13066 			}
13067 		}
13068 #endif
13069 	}
13070 #ifdef TCP_ACCOUNTING
13071 	ts_val = get_cyclecount();
13072 #endif
13073 	acked_amount = acked = (high_seq - tp->snd_una);
13074 	if (win_up_req) {
13075 		rack_do_win_updates(tp, rack, the_win, win_seq, win_upd_ack, cts, high_seq);
13076 	}
13077 	if (acked) {
13078 		if (rack->sack_attack_disable == 0)
13079 			rack_do_decay(rack);
13080 		if (acked >= segsiz) {
13081 			/*
13082 			 * You only get credit for
13083 			 * MSS and greater (and you get extra
13084 			 * credit for larger cum-ack moves).
13085 			 */
13086 			int ac;
13087 
13088 			ac = acked / segsiz;
13089 			rack->r_ctl.ack_count += ac;
13090 			counter_u64_add(rack_ack_total, ac);
13091 		}
13092 		if (rack->r_ctl.ack_count > 0xfff00000) {
13093 			/*
13094 			 * reduce the number to keep us under
13095 			 * a uint32_t.
13096 			 */
13097 			rack->r_ctl.ack_count /= 2;
13098 			rack->r_ctl.sack_count /= 2;
13099 		}
13100 		if (tp->t_flags & TF_NEEDSYN) {
13101 			/*
13102 			 * T/TCP: Connection was half-synchronized, and our SYN has
13103 			 * been ACK'd (so connection is now fully synchronized).  Go
13104 			 * to non-starred state, increment snd_una for ACK of SYN,
13105 			 * and check if we can do window scaling.
13106 			 */
13107 			tp->t_flags &= ~TF_NEEDSYN;
13108 			tp->snd_una++;
13109 			acked_amount = acked = (high_seq - tp->snd_una);
13110 		}
13111 		if (acked > sbavail(&so->so_snd))
13112 			acked_amount = sbavail(&so->so_snd);
13113 #ifdef NETFLIX_EXP_DETECTION
13114 		/*
13115 		 * We only care on a cum-ack move if we are in a sack-disabled
13116 		 * state. We have already added in to the ack_count, and we never
13117 		 * would disable on a cum-ack move, so we only care to do the
13118 		 * detection if it may "undo" it, i.e. we were in disabled already.
13119 		 */
13120 		if (rack->sack_attack_disable)
13121 			rack_do_detection(tp, rack, acked_amount, segsiz);
13122 #endif
13123 		if (IN_FASTRECOVERY(tp->t_flags) &&
13124 		    (rack->rack_no_prr == 0))
13125 			rack_update_prr(tp, rack, acked_amount, high_seq);
13126 		if (IN_RECOVERY(tp->t_flags)) {
13127 			if (SEQ_LT(high_seq, tp->snd_recover) &&
13128 			    (SEQ_LT(high_seq, tp->snd_max))) {
13129 				tcp_rack_partialack(tp);
13130 			} else {
13131 				rack_post_recovery(tp, high_seq);
13132 				recovery = 1;
13133 			}
13134 		}
13135 		/* Handle the rack-log-ack part (sendmap) */
13136 		if ((sbused(&so->so_snd) == 0) &&
13137 		    (acked > acked_amount) &&
13138 		    (tp->t_state >= TCPS_FIN_WAIT_1) &&
13139 		    (tp->t_flags & TF_SENTFIN)) {
13140 			/*
13141 			 * We must be sure our fin
13142 			 * was sent and acked (we can be
13143 			 * in FIN_WAIT_1 without having
13144 			 * sent the fin).
13145 			 */
13146 			ourfinisacked = 1;
13147 			/*
13148 			 * Lets make sure snd_una is updated
13149 			 * since most likely acked_amount = 0 (it
13150 			 * should be).
13151 			 */
13152 			tp->snd_una = high_seq;
13153 		}
13154 		/* Did we make a RTO error? */
13155 		if ((tp->t_flags & TF_PREVVALID) &&
13156 		    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
13157 			tp->t_flags &= ~TF_PREVVALID;
13158 			if (tp->t_rxtshift == 1 &&
13159 			    (int)(ticks - tp->t_badrxtwin) < 0)
13160 				rack_cong_signal(tp, CC_RTO_ERR, high_seq);
13161 		}
13162 		/* Handle the data in the socket buffer */
13163 		KMOD_TCPSTAT_ADD(tcps_rcvackpack, 1);
13164 		KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
13165 		if (acked_amount > 0) {
13166 			struct mbuf *mfree;
13167 
13168 			rack_ack_received(tp, rack, high_seq, nsegs, CC_ACK, recovery);
13169 			SOCKBUF_LOCK(&so->so_snd);
13170 			mfree = sbcut_locked(&so->so_snd, acked);
13171 			tp->snd_una = high_seq;
13172 			/* Note we want to hold the sb lock through the sendmap adjust */
13173 			rack_adjust_sendmap(rack, &so->so_snd, tp->snd_una);
13174 			/* Wake up the socket if we have room to write more */
13175 			rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
13176 			sowwakeup_locked(so);
13177 			m_freem(mfree);
13178 		}
13179 		/* update progress */
13180 		tp->t_acktime = ticks;
13181 		rack_log_progress_event(rack, tp, tp->t_acktime,
13182 					PROGRESS_UPDATE, __LINE__);
13183 		/* Clear out shifts and such */
13184 		tp->t_rxtshift = 0;
13185 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
13186 				   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
13187 		rack->rc_tlp_in_progress = 0;
13188 		rack->r_ctl.rc_tlp_cnt_out = 0;
13189 		/* Send recover and snd_nxt must be dragged along */
13190 		if (SEQ_GT(tp->snd_una, tp->snd_recover))
13191 			tp->snd_recover = tp->snd_una;
13192 		if (SEQ_LT(tp->snd_nxt, tp->snd_una))
13193 			tp->snd_nxt = tp->snd_una;
13194 		/*
13195 		 * If the RXT timer is running we want to
13196 		 * stop it, so we can restart a TLP (or new RXT).
13197 		 */
13198 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
13199 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13200 #ifdef NETFLIX_HTTP_LOGGING
13201 		tcp_http_check_for_comp(rack->rc_tp, high_seq);
13202 #endif
13203 		tp->snd_wl2 = high_seq;
13204 		tp->t_dupacks = 0;
13205 		if (under_pacing &&
13206 		    (rack->use_fixed_rate == 0) &&
13207 		    (rack->in_probe_rtt == 0) &&
13208 		    rack->rc_gp_dyn_mul &&
13209 		    rack->rc_always_pace) {
13210 			/* Check if we are dragging bottom */
13211 			rack_check_bottom_drag(tp, rack, so, acked);
13212 		}
13213 		if (tp->snd_una == tp->snd_max) {
13214 			tp->t_flags &= ~TF_PREVVALID;
13215 			rack->r_ctl.retran_during_recovery = 0;
13216 			rack->r_ctl.dsack_byte_cnt = 0;
13217 			rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
13218 			if (rack->r_ctl.rc_went_idle_time == 0)
13219 				rack->r_ctl.rc_went_idle_time = 1;
13220 			rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
13221 			if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0)
13222 				tp->t_acktime = 0;
13223 			/* Set so we might enter persists... */
13224 			rack->r_wanted_output = 1;
13225 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13226 			sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
13227 			if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
13228 			    (sbavail(&so->so_snd) == 0) &&
13229 			    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
13230 				/*
13231 				 * The socket was gone and the
13232 				 * peer sent data (not now in the past), time to
13233 				 * reset him.
13234 				 */
13235 				rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13236 				/* tcp_close will kill the inp pre-log the Reset */
13237 				tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
13238 #ifdef TCP_ACCOUNTING
13239 				rdstc = get_cyclecount();
13240 				if (rdstc > ts_val) {
13241 					counter_u64_add(tcp_proc_time[ACK_CUMACK] , (rdstc - ts_val));
13242 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13243 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13244 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13245 					}
13246 				}
13247 #endif
13248 				m_freem(m);
13249 				tp = tcp_close(tp);
13250 				if (tp == NULL) {
13251 #ifdef TCP_ACCOUNTING
13252 					sched_unpin();
13253 #endif
13254 					return (1);
13255 				}
13256 				/*
13257 				 * We would normally do drop-with-reset which would
13258 				 * send back a reset. We can't since we don't have
13259 				 * all the needed bits. Instead lets arrange for
13260 				 * a call to tcp_output(). That way since we
13261 				 * are in the closed state we will generate a reset.
13262 				 *
13263 				 * Note if tcp_accounting is on we don't unpin since
13264 				 * we do that after the goto label.
13265 				 */
13266 				goto send_out_a_rst;
13267 			}
13268 			if ((sbused(&so->so_snd) == 0) &&
13269 			    (tp->t_state >= TCPS_FIN_WAIT_1) &&
13270 			    (tp->t_flags & TF_SENTFIN)) {
13271 				/*
13272 				 * If we can't receive any more data, then closing user can
13273 				 * proceed. Starting the timer is contrary to the
13274 				 * specification, but if we don't get a FIN we'll hang
13275 				 * forever.
13276 				 *
13277 				 */
13278 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13279 					soisdisconnected(so);
13280 					tcp_timer_activate(tp, TT_2MSL,
13281 							   (tcp_fast_finwait2_recycle ?
13282 							    tcp_finwait2_timeout :
13283 							    TP_MAXIDLE(tp)));
13284 				}
13285 				if (ourfinisacked == 0) {
13286 					/*
13287 					 * We don't change to fin-wait-2 if we have our fin acked
13288 					 * which means we are probably in TCPS_CLOSING.
13289 					 */
13290 					tcp_state_change(tp, TCPS_FIN_WAIT_2);
13291 				}
13292 			}
13293 		}
13294 		/* Wake up the socket if we have room to write more */
13295 		if (sbavail(&so->so_snd)) {
13296 			rack->r_wanted_output = 1;
13297 			if (ctf_progress_timeout_check(tp, true)) {
13298 				rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
13299 							tp, tick, PROGRESS_DROP, __LINE__);
13300 				tcp_set_inp_to_drop(tp->t_inpcb, ETIMEDOUT);
13301 				/*
13302 				 * We cheat here and don't send a RST, we should send one
13303 				 * when the pacer drops the connection.
13304 				 */
13305 #ifdef TCP_ACCOUNTING
13306 				rdstc = get_cyclecount();
13307 				if (rdstc > ts_val) {
13308 					counter_u64_add(tcp_proc_time[ACK_CUMACK] , (rdstc - ts_val));
13309 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13310 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13311 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13312 					}
13313 				}
13314 				sched_unpin();
13315 #endif
13316 				INP_WUNLOCK(rack->rc_inp);
13317 				m_freem(m);
13318 				return (1);
13319 			}
13320 		}
13321 		if (ourfinisacked) {
13322 			switch(tp->t_state) {
13323 			case TCPS_CLOSING:
13324 #ifdef TCP_ACCOUNTING
13325 				rdstc = get_cyclecount();
13326 				if (rdstc > ts_val) {
13327 					counter_u64_add(tcp_proc_time[ACK_CUMACK] ,
13328 							(rdstc - ts_val));
13329 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13330 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13331 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13332 					}
13333 				}
13334 				sched_unpin();
13335 #endif
13336 				tcp_twstart(tp);
13337 				m_freem(m);
13338 				return (1);
13339 				break;
13340 			case TCPS_LAST_ACK:
13341 #ifdef TCP_ACCOUNTING
13342 				rdstc = get_cyclecount();
13343 				if (rdstc > ts_val) {
13344 					counter_u64_add(tcp_proc_time[ACK_CUMACK] ,
13345 							(rdstc - ts_val));
13346 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13347 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13348 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13349 					}
13350 				}
13351 				sched_unpin();
13352 #endif
13353 				tp = tcp_close(tp);
13354 				ctf_do_drop(m, tp);
13355 				return (1);
13356 				break;
13357 			case TCPS_FIN_WAIT_1:
13358 #ifdef TCP_ACCOUNTING
13359 				rdstc = get_cyclecount();
13360 				if (rdstc > ts_val) {
13361 					counter_u64_add(tcp_proc_time[ACK_CUMACK] ,
13362 							(rdstc - ts_val));
13363 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13364 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13365 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13366 					}
13367 				}
13368 #endif
13369 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13370 					soisdisconnected(so);
13371 					tcp_timer_activate(tp, TT_2MSL,
13372 							   (tcp_fast_finwait2_recycle ?
13373 							    tcp_finwait2_timeout :
13374 							    TP_MAXIDLE(tp)));
13375 				}
13376 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
13377 				break;
13378 			default:
13379 				break;
13380 			}
13381 		}
13382 		if (rack->r_fast_output) {
13383 			/*
13384 			 * We re doing fast output.. can we expand that?
13385 			 */
13386 			rack_gain_for_fastoutput(rack, tp, so, acked_amount);
13387 		}
13388 #ifdef TCP_ACCOUNTING
13389 		rdstc = get_cyclecount();
13390 		if (rdstc > ts_val) {
13391 			counter_u64_add(tcp_proc_time[ACK_CUMACK] , (rdstc - ts_val));
13392 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13393 				tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13394 				tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13395 			}
13396 		}
13397 
13398 	} else if (win_up_req) {
13399 		rdstc = get_cyclecount();
13400 		if (rdstc > ts_val) {
13401 			counter_u64_add(tcp_proc_time[ACK_RWND] , (rdstc - ts_val));
13402 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13403 				tp->tcp_proc_time[ACK_RWND] += (rdstc - ts_val);
13404 			}
13405 		}
13406 #endif
13407 	}
13408 	/* Now is there a next packet, if so we are done */
13409 	m_freem(m);
13410 	did_out = 0;
13411 	if (nxt_pkt) {
13412 #ifdef TCP_ACCOUNTING
13413 		sched_unpin();
13414 #endif
13415 		rack_log_doseg_done(rack, cts, nxt_pkt, did_out, 5, nsegs);
13416 		return (0);
13417 	}
13418 	rack_handle_might_revert(tp, rack);
13419 	ctf_calc_rwin(so, tp);
13420 	if ((rack->r_wanted_output != 0) || (rack->r_fast_output != 0)) {
13421 	send_out_a_rst:
13422 		(void)tp->t_fb->tfb_tcp_output(tp);
13423 		did_out = 1;
13424 	}
13425 	rack_free_trim(rack);
13426 #ifdef TCP_ACCOUNTING
13427 	sched_unpin();
13428 #endif
13429 	rack_timer_audit(tp, rack, &so->so_snd);
13430 	rack_log_doseg_done(rack, cts, nxt_pkt, did_out, 6, nsegs);
13431 	return (0);
13432 }
13433 
13434 
13435 static int
13436 rack_do_segment_nounlock(struct mbuf *m, struct tcphdr *th, struct socket *so,
13437     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos,
13438     int32_t nxt_pkt, struct timeval *tv)
13439 {
13440 #ifdef TCP_ACCOUNTING
13441 	uint64_t ts_val;
13442 #endif
13443 	int32_t thflags, retval, did_out = 0;
13444 	int32_t way_out = 0;
13445 	uint32_t cts;
13446 	uint32_t tiwin;
13447 	struct timespec ts;
13448 	struct tcpopt to;
13449 	struct tcp_rack *rack;
13450 	struct rack_sendmap *rsm;
13451 	int32_t prev_state = 0;
13452 #ifdef TCP_ACCOUNTING
13453 	int ack_val_set = 0xf;
13454 #endif
13455 	int nsegs;
13456 	uint32_t us_cts;
13457 	/*
13458 	 * tv passed from common code is from either M_TSTMP_LRO or
13459 	 * tcp_get_usecs() if no LRO m_pkthdr timestamp is present.
13460 	 */
13461 	if (m->m_flags & M_ACKCMP) {
13462 		return (rack_do_compressed_ack_processing(tp, so, m, nxt_pkt, tv));
13463 	}
13464 	if (m->m_flags & M_ACKCMP) {
13465 		panic("Impossible reach m has ackcmp? m:%p tp:%p", m, tp);
13466 	}
13467 	nsegs = m->m_pkthdr.lro_nsegs;
13468 	counter_u64_add(rack_proc_non_comp_ack, 1);
13469 	thflags = th->th_flags;
13470 #ifdef TCP_ACCOUNTING
13471 	sched_pin();
13472 	if (thflags & TH_ACK)
13473 		ts_val = get_cyclecount();
13474 #endif
13475 	cts = tcp_tv_to_usectick(tv);
13476 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13477 
13478 	if ((m->m_flags & M_TSTMP) ||
13479 	    (m->m_flags & M_TSTMP_LRO)) {
13480 		mbuf_tstmp2timespec(m, &ts);
13481 		rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
13482 		rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
13483 	} else
13484 		rack->r_ctl.act_rcv_time = *tv;
13485 	kern_prefetch(rack, &prev_state);
13486 	prev_state = 0;
13487 	/*
13488 	 * Unscale the window into a 32-bit value. For the SYN_SENT state
13489 	 * the scale is zero.
13490 	 */
13491 	tiwin = th->th_win << tp->snd_scale;
13492 	/*
13493 	 * Parse options on any incoming segment.
13494 	 */
13495 	memset(&to, 0, sizeof(to));
13496 	tcp_dooptions(&to, (u_char *)(th + 1),
13497 	    (th->th_off << 2) - sizeof(struct tcphdr),
13498 	    (thflags & TH_SYN) ? TO_SYN : 0);
13499 #ifdef TCP_ACCOUNTING
13500 	if (thflags & TH_ACK) {
13501 		/*
13502 		 * We have a tradeoff here. We can either do what we are
13503 		 * doing i.e. pinning to this CPU and then doing the accounting
13504 		 * <or> we could do a critical enter, setup the rdtsc and cpu
13505 		 * as in below, and then validate we are on the same CPU on
13506 		 * exit. I have choosen to not do the critical enter since
13507 		 * that often will gain you a context switch, and instead lock
13508 		 * us (line above this if) to the same CPU with sched_pin(). This
13509 		 * means we may be context switched out for a higher priority
13510 		 * interupt but we won't be moved to another CPU.
13511 		 *
13512 		 * If this occurs (which it won't very often since we most likely
13513 		 * are running this code in interupt context and only a higher
13514 		 * priority will bump us ... clock?) we will falsely add in
13515 		 * to the time the interupt processing time plus the ack processing
13516 		 * time. This is ok since its a rare event.
13517 		 */
13518 		ack_val_set = tcp_do_ack_accounting(tp, th, &to, tiwin,
13519 						    ctf_fixed_maxseg(tp));
13520 	}
13521 #endif
13522 	NET_EPOCH_ASSERT();
13523 	INP_WLOCK_ASSERT(tp->t_inpcb);
13524 	KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN",
13525 	    __func__));
13526 	KASSERT(tp->t_state != TCPS_TIME_WAIT, ("%s: TCPS_TIME_WAIT",
13527 	    __func__));
13528 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
13529 		union tcp_log_stackspecific log;
13530 		struct timeval ltv;
13531 #ifdef NETFLIX_HTTP_LOGGING
13532 		struct http_sendfile_track *http_req;
13533 
13534 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
13535 			http_req = tcp_http_find_req_for_seq(tp, (th->th_ack-1));
13536 		} else {
13537 			http_req = tcp_http_find_req_for_seq(tp, th->th_ack);
13538 		}
13539 #endif
13540 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
13541 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
13542 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
13543 		if (rack->rack_no_prr == 0)
13544 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
13545 		else
13546 			log.u_bbr.flex1 = 0;
13547 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
13548 		log.u_bbr.use_lt_bw <<= 1;
13549 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
13550 		log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
13551 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
13552 		log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
13553 		log.u_bbr.flex3 = m->m_flags;
13554 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
13555 		log.u_bbr.lost = thflags;
13556 		log.u_bbr.pacing_gain = 0x1;
13557 #ifdef TCP_ACCOUNTING
13558 		log.u_bbr.cwnd_gain = ack_val_set;
13559 #endif
13560 		log.u_bbr.flex7 = 2;
13561 		if (m->m_flags & M_TSTMP) {
13562 			/* Record the hardware timestamp if present */
13563 			mbuf_tstmp2timespec(m, &ts);
13564 			ltv.tv_sec = ts.tv_sec;
13565 			ltv.tv_usec = ts.tv_nsec / 1000;
13566 			log.u_bbr.lt_epoch = tcp_tv_to_usectick(&ltv);
13567 		} else if (m->m_flags & M_TSTMP_LRO) {
13568 			/* Record the LRO the arrival timestamp */
13569 			mbuf_tstmp2timespec(m, &ts);
13570 			ltv.tv_sec = ts.tv_sec;
13571 			ltv.tv_usec = ts.tv_nsec / 1000;
13572 			log.u_bbr.flex5 = tcp_tv_to_usectick(&ltv);
13573 		}
13574 		log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
13575 		/* Log the rcv time */
13576 		log.u_bbr.delRate = m->m_pkthdr.rcv_tstmp;
13577 #ifdef NETFLIX_HTTP_LOGGING
13578 		log.u_bbr.applimited = tp->t_http_closed;
13579 		log.u_bbr.applimited <<= 8;
13580 		log.u_bbr.applimited |= tp->t_http_open;
13581 		log.u_bbr.applimited <<= 8;
13582 		log.u_bbr.applimited |= tp->t_http_req;
13583 		if (http_req) {
13584 			/* Copy out any client req info */
13585 			/* seconds */
13586 			log.u_bbr.pkt_epoch = (http_req->localtime / HPTS_USEC_IN_SEC);
13587 			/* useconds */
13588 			log.u_bbr.delivered = (http_req->localtime % HPTS_USEC_IN_SEC);
13589 			log.u_bbr.rttProp = http_req->timestamp;
13590 			log.u_bbr.cur_del_rate = http_req->start;
13591 			if (http_req->flags & TCP_HTTP_TRACK_FLG_OPEN) {
13592 				log.u_bbr.flex8 |= 1;
13593 			} else {
13594 				log.u_bbr.flex8 |= 2;
13595 				log.u_bbr.bw_inuse = http_req->end;
13596 			}
13597 			log.u_bbr.flex6 = http_req->start_seq;
13598 			if (http_req->flags & TCP_HTTP_TRACK_FLG_COMP) {
13599 				log.u_bbr.flex8 |= 4;
13600 				log.u_bbr.epoch = http_req->end_seq;
13601 			}
13602 		}
13603 #endif
13604 		TCP_LOG_EVENTP(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_IN, 0,
13605 		    tlen, &log, true, &ltv);
13606 	}
13607 	if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) {
13608 		way_out = 4;
13609 		retval = 0;
13610 		m_freem(m);
13611 		goto done_with_input;
13612 	}
13613 	/*
13614 	 * If a segment with the ACK-bit set arrives in the SYN-SENT state
13615 	 * check SEQ.ACK first as described on page 66 of RFC 793, section 3.9.
13616 	 */
13617 	if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) &&
13618 	    (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) {
13619 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
13620 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
13621 #ifdef TCP_ACCOUNTING
13622 		sched_unpin();
13623 #endif
13624 		return (1);
13625 	}
13626 
13627 	/*
13628 	 * Parse options on any incoming segment.
13629 	 */
13630 	tcp_dooptions(&to, (u_char *)(th + 1),
13631 	    (th->th_off << 2) - sizeof(struct tcphdr),
13632 	    (thflags & TH_SYN) ? TO_SYN : 0);
13633 
13634 	/*
13635 	 * If timestamps were negotiated during SYN/ACK and a
13636 	 * segment without a timestamp is received, silently drop
13637 	 * the segment, unless it is a RST segment or missing timestamps are
13638 	 * tolerated.
13639 	 * See section 3.2 of RFC 7323.
13640 	 */
13641 	if ((tp->t_flags & TF_RCVD_TSTMP) && !(to.to_flags & TOF_TS) &&
13642 	    ((thflags & TH_RST) == 0) && (V_tcp_tolerate_missing_ts == 0)) {
13643 		way_out = 5;
13644 		retval = 0;
13645 		m_freem(m);
13646 		goto done_with_input;
13647 	}
13648 
13649 	/*
13650 	 * Segment received on connection. Reset idle time and keep-alive
13651 	 * timer. XXX: This should be done after segment validation to
13652 	 * ignore broken/spoofed segs.
13653 	 */
13654 	if  (tp->t_idle_reduce &&
13655 	     (tp->snd_max == tp->snd_una) &&
13656 	     ((ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
13657 		counter_u64_add(rack_input_idle_reduces, 1);
13658 		rack_cc_after_idle(rack, tp);
13659 	}
13660 	tp->t_rcvtime = ticks;
13661 #ifdef STATS
13662 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_FRWIN, tiwin);
13663 #endif
13664 	if (tiwin > rack->r_ctl.rc_high_rwnd)
13665 		rack->r_ctl.rc_high_rwnd = tiwin;
13666 	/*
13667 	 * TCP ECN processing. XXXJTL: If we ever use ECN, we need to move
13668 	 * this to occur after we've validated the segment.
13669 	 */
13670 	if (tp->t_flags2 & TF2_ECN_PERMIT) {
13671 		if (thflags & TH_CWR) {
13672 			tp->t_flags2 &= ~TF2_ECN_SND_ECE;
13673 			tp->t_flags |= TF_ACKNOW;
13674 		}
13675 		switch (iptos & IPTOS_ECN_MASK) {
13676 		case IPTOS_ECN_CE:
13677 			tp->t_flags2 |= TF2_ECN_SND_ECE;
13678 			KMOD_TCPSTAT_INC(tcps_ecn_ce);
13679 			break;
13680 		case IPTOS_ECN_ECT0:
13681 			KMOD_TCPSTAT_INC(tcps_ecn_ect0);
13682 			break;
13683 		case IPTOS_ECN_ECT1:
13684 			KMOD_TCPSTAT_INC(tcps_ecn_ect1);
13685 			break;
13686 		}
13687 
13688 		/* Process a packet differently from RFC3168. */
13689 		cc_ecnpkt_handler(tp, th, iptos);
13690 
13691 		/* Congestion experienced. */
13692 		if (thflags & TH_ECE) {
13693 			rack_cong_signal(tp, CC_ECN, th->th_ack);
13694 		}
13695 	}
13696 
13697 	/*
13698 	 * If echoed timestamp is later than the current time, fall back to
13699 	 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
13700 	 * were used when this connection was established.
13701 	 */
13702 	if ((to.to_flags & TOF_TS) && (to.to_tsecr != 0)) {
13703 		to.to_tsecr -= tp->ts_offset;
13704 		if (TSTMP_GT(to.to_tsecr, cts))
13705 			to.to_tsecr = 0;
13706 	}
13707 
13708 	/*
13709 	 * If its the first time in we need to take care of options and
13710 	 * verify we can do SACK for rack!
13711 	 */
13712 	if (rack->r_state == 0) {
13713 		/* Should be init'd by rack_init() */
13714 		KASSERT(rack->rc_inp != NULL,
13715 		    ("%s: rack->rc_inp unexpectedly NULL", __func__));
13716 		if (rack->rc_inp == NULL) {
13717 			rack->rc_inp = tp->t_inpcb;
13718 		}
13719 
13720 		/*
13721 		 * Process options only when we get SYN/ACK back. The SYN
13722 		 * case for incoming connections is handled in tcp_syncache.
13723 		 * According to RFC1323 the window field in a SYN (i.e., a
13724 		 * <SYN> or <SYN,ACK>) segment itself is never scaled. XXX
13725 		 * this is traditional behavior, may need to be cleaned up.
13726 		 */
13727 		if (tp->t_state == TCPS_SYN_SENT && (thflags & TH_SYN)) {
13728 			/* Handle parallel SYN for ECN */
13729 			if (!(thflags & TH_ACK) &&
13730 			    ((thflags & (TH_CWR | TH_ECE)) == (TH_CWR | TH_ECE)) &&
13731 			    ((V_tcp_do_ecn == 1) || (V_tcp_do_ecn == 2))) {
13732 				tp->t_flags2 |= TF2_ECN_PERMIT;
13733 				tp->t_flags2 |= TF2_ECN_SND_ECE;
13734 				TCPSTAT_INC(tcps_ecn_shs);
13735 			}
13736 			if ((to.to_flags & TOF_SCALE) &&
13737 			    (tp->t_flags & TF_REQ_SCALE)) {
13738 				tp->t_flags |= TF_RCVD_SCALE;
13739 				tp->snd_scale = to.to_wscale;
13740 			} else
13741 				tp->t_flags &= ~TF_REQ_SCALE;
13742 			/*
13743 			 * Initial send window.  It will be updated with the
13744 			 * next incoming segment to the scaled value.
13745 			 */
13746 			tp->snd_wnd = th->th_win;
13747 			rack_validate_fo_sendwin_up(tp, rack);
13748 			if ((to.to_flags & TOF_TS) &&
13749 			    (tp->t_flags & TF_REQ_TSTMP)) {
13750 				tp->t_flags |= TF_RCVD_TSTMP;
13751 				tp->ts_recent = to.to_tsval;
13752 				tp->ts_recent_age = cts;
13753 			} else
13754 				tp->t_flags &= ~TF_REQ_TSTMP;
13755 			if (to.to_flags & TOF_MSS) {
13756 				tcp_mss(tp, to.to_mss);
13757 			}
13758 			if ((tp->t_flags & TF_SACK_PERMIT) &&
13759 			    (to.to_flags & TOF_SACKPERM) == 0)
13760 				tp->t_flags &= ~TF_SACK_PERMIT;
13761 			if (IS_FASTOPEN(tp->t_flags)) {
13762 				if (to.to_flags & TOF_FASTOPEN) {
13763 					uint16_t mss;
13764 
13765 					if (to.to_flags & TOF_MSS)
13766 						mss = to.to_mss;
13767 					else
13768 						if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0)
13769 							mss = TCP6_MSS;
13770 						else
13771 							mss = TCP_MSS;
13772 					tcp_fastopen_update_cache(tp, mss,
13773 					    to.to_tfo_len, to.to_tfo_cookie);
13774 				} else
13775 					tcp_fastopen_disable_path(tp);
13776 			}
13777 		}
13778 		/*
13779 		 * At this point we are at the initial call. Here we decide
13780 		 * if we are doing RACK or not. We do this by seeing if
13781 		 * TF_SACK_PERMIT is set and the sack-not-required is clear.
13782 		 * The code now does do dup-ack counting so if you don't
13783 		 * switch back you won't get rack & TLP, but you will still
13784 		 * get this stack.
13785 		 */
13786 
13787 		if ((rack_sack_not_required == 0) &&
13788 		    ((tp->t_flags & TF_SACK_PERMIT) == 0)) {
13789 			tcp_switch_back_to_default(tp);
13790 			(*tp->t_fb->tfb_tcp_do_segment) (m, th, so, tp, drop_hdrlen,
13791 			    tlen, iptos);
13792 #ifdef TCP_ACCOUNTING
13793 			sched_unpin();
13794 #endif
13795 			return (1);
13796 		}
13797 		tcp_set_hpts(tp->t_inpcb);
13798 		sack_filter_clear(&rack->r_ctl.rack_sf, th->th_ack);
13799 	}
13800 	if (thflags & TH_FIN)
13801 		tcp_log_end_status(tp, TCP_EI_STATUS_CLIENT_FIN);
13802 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
13803 	if ((rack->rc_gp_dyn_mul) &&
13804 	    (rack->use_fixed_rate == 0) &&
13805 	    (rack->rc_always_pace)) {
13806 		/* Check in on probertt */
13807 		rack_check_probe_rtt(rack, us_cts);
13808 	}
13809 	if (rack->forced_ack) {
13810 		uint32_t us_rtt;
13811 
13812 		/*
13813 		 * A persist or keep-alive was forced out, update our
13814 		 * min rtt time. Note we do not worry about lost
13815 		 * retransmissions since KEEP-ALIVES and persists
13816 		 * are usually way long on times of sending (though
13817 		 * if we were really paranoid or worried we could
13818 		 * at least use timestamps if available to validate).
13819 		 */
13820 		rack->forced_ack = 0;
13821 		us_rtt = us_cts - rack->r_ctl.forced_ack_ts;
13822 		if (us_rtt == 0)
13823 			us_rtt = 1;
13824 		rack_log_rtt_upd(tp, rack, us_rtt, 0, NULL, 3);
13825 		rack_apply_updated_usrtt(rack, us_rtt, us_cts);
13826 	}
13827 	/*
13828 	 * This is the one exception case where we set the rack state
13829 	 * always. All other times (timers etc) we must have a rack-state
13830 	 * set (so we assure we have done the checks above for SACK).
13831 	 */
13832 	rack->r_ctl.rc_rcvtime = cts;
13833 	if (rack->r_state != tp->t_state)
13834 		rack_set_state(tp, rack);
13835 	if (SEQ_GT(th->th_ack, tp->snd_una) &&
13836 	    (rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree)) != NULL)
13837 		kern_prefetch(rsm, &prev_state);
13838 	prev_state = rack->r_state;
13839 	rack_clear_rate_sample(rack);
13840 	retval = (*rack->r_substate) (m, th, so,
13841 	    tp, &to, drop_hdrlen,
13842 	    tlen, tiwin, thflags, nxt_pkt, iptos);
13843 #ifdef INVARIANTS
13844 	if ((retval == 0) &&
13845 	    (tp->t_inpcb == NULL)) {
13846 		panic("retval:%d tp:%p t_inpcb:NULL state:%d",
13847 		    retval, tp, prev_state);
13848 	}
13849 #endif
13850 	if (retval == 0) {
13851 		/*
13852 		 * If retval is 1 the tcb is unlocked and most likely the tp
13853 		 * is gone.
13854 		 */
13855 		INP_WLOCK_ASSERT(tp->t_inpcb);
13856 		if ((rack->rc_gp_dyn_mul) &&
13857 		    (rack->rc_always_pace) &&
13858 		    (rack->use_fixed_rate == 0) &&
13859 		    rack->in_probe_rtt &&
13860 		    (rack->r_ctl.rc_time_probertt_starts == 0)) {
13861 			/*
13862 			 * If we are going for target, lets recheck before
13863 			 * we output.
13864 			 */
13865 			rack_check_probe_rtt(rack, us_cts);
13866 		}
13867 		if (rack->set_pacing_done_a_iw == 0) {
13868 			/* How much has been acked? */
13869 			if ((tp->snd_una - tp->iss) > (ctf_fixed_maxseg(tp) * 10)) {
13870 				/* We have enough to set in the pacing segment size */
13871 				rack->set_pacing_done_a_iw = 1;
13872 				rack_set_pace_segments(tp, rack, __LINE__, NULL);
13873 			}
13874 		}
13875 		tcp_rack_xmit_timer_commit(rack, tp);
13876 #ifdef TCP_ACCOUNTING
13877 		/*
13878 		 * If we set the ack_val_se to what ack processing we are doing
13879 		 * we also want to track how many cycles we burned. Note
13880 		 * the bits after tcp_output we let be "free". This is because
13881 		 * we are also tracking the tcp_output times as well. Note the
13882 		 * use of 0xf here since we only have 11 counter (0 - 0xa) and
13883 		 * 0xf cannot be returned and is what we initialize it too to
13884 		 * indicate we are not doing the tabulations.
13885 		 */
13886 		if (ack_val_set != 0xf) {
13887 			uint64_t crtsc;
13888 
13889 			crtsc = get_cyclecount();
13890 			counter_u64_add(tcp_proc_time[ack_val_set] , (crtsc - ts_val));
13891 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13892 				tp->tcp_proc_time[ack_val_set] += (crtsc - ts_val);
13893 			}
13894 		}
13895 #endif
13896 		if (nxt_pkt == 0) {
13897 			if ((rack->r_wanted_output != 0) || (rack->r_fast_output != 0)) {
13898 do_output_now:
13899 				did_out = 1;
13900 				(void)tp->t_fb->tfb_tcp_output(tp);
13901 			}
13902 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
13903 			rack_free_trim(rack);
13904 		}
13905 		if ((nxt_pkt == 0) &&
13906 		    ((rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) == 0) &&
13907 		    (SEQ_GT(tp->snd_max, tp->snd_una) ||
13908 		     (tp->t_flags & TF_DELACK) ||
13909 		     ((V_tcp_always_keepalive || rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
13910 		      (tp->t_state <= TCPS_CLOSING)))) {
13911 			/* We could not send (probably in the hpts but stopped the timer earlier)? */
13912 			if ((tp->snd_max == tp->snd_una) &&
13913 			    ((tp->t_flags & TF_DELACK) == 0) &&
13914 			    (rack->rc_inp->inp_in_hpts) &&
13915 			    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
13916 				/* keep alive not needed if we are hptsi output yet */
13917 				;
13918 			} else {
13919 				int late = 0;
13920 				if (rack->rc_inp->inp_in_hpts) {
13921 					if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
13922 						us_cts = tcp_get_usecs(NULL);
13923 						if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
13924 							rack->r_early = 1;
13925 							rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
13926 						} else
13927 							late = 1;
13928 						rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
13929 					}
13930 					tcp_hpts_remove(tp->t_inpcb, HPTS_REMOVE_OUTPUT);
13931 				}
13932 				if (late && (did_out == 0)) {
13933 					/*
13934 					 * We are late in the sending
13935 					 * and we did not call the output
13936 					 * (this probably should not happen).
13937 					 */
13938 					goto do_output_now;
13939 				}
13940 				rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
13941 			}
13942 			way_out = 1;
13943 		} else if (nxt_pkt == 0) {
13944 			/* Do we have the correct timer running? */
13945 			rack_timer_audit(tp, rack, &so->so_snd);
13946 			way_out = 2;
13947 		}
13948 	done_with_input:
13949 		rack_log_doseg_done(rack, cts, nxt_pkt, did_out, way_out, max(1, nsegs));
13950 		if (did_out)
13951 			rack->r_wanted_output = 0;
13952 #ifdef INVARIANTS
13953 		if (tp->t_inpcb == NULL) {
13954 			panic("OP:%d retval:%d tp:%p t_inpcb:NULL state:%d",
13955 			      did_out,
13956 			      retval, tp, prev_state);
13957 		}
13958 #endif
13959 #ifdef TCP_ACCOUNTING
13960 	} else {
13961 		/*
13962 		 * Track the time (see above).
13963 		 */
13964 		if (ack_val_set != 0xf) {
13965 			uint64_t crtsc;
13966 
13967 			crtsc = get_cyclecount();
13968 			counter_u64_add(tcp_proc_time[ack_val_set] , (crtsc - ts_val));
13969 			/*
13970 			 * Note we *DO NOT* increment the per-tcb counters since
13971 			 * in the else the TP may be gone!!
13972 			 */
13973 		}
13974 #endif
13975 	}
13976 #ifdef TCP_ACCOUNTING
13977 	sched_unpin();
13978 #endif
13979 	return (retval);
13980 }
13981 
13982 void
13983 rack_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
13984     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos)
13985 {
13986 	struct timeval tv;
13987 
13988 	/* First lets see if we have old packets */
13989 	if (tp->t_in_pkt) {
13990 		if (ctf_do_queued_segments(so, tp, 1)) {
13991 			m_freem(m);
13992 			return;
13993 		}
13994 	}
13995 	if (m->m_flags & M_TSTMP_LRO) {
13996 		tv.tv_sec = m->m_pkthdr.rcv_tstmp /1000000000;
13997 		tv.tv_usec = (m->m_pkthdr.rcv_tstmp % 1000000000)/1000;
13998 	} else {
13999 		/* Should not be should we kassert instead? */
14000 		tcp_get_usecs(&tv);
14001 	}
14002 	if (rack_do_segment_nounlock(m, th, so, tp,
14003 				     drop_hdrlen, tlen, iptos, 0, &tv) == 0) {
14004 		INP_WUNLOCK(tp->t_inpcb);
14005 	}
14006 }
14007 
14008 struct rack_sendmap *
14009 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack, uint32_t tsused)
14010 {
14011 	struct rack_sendmap *rsm = NULL;
14012 	int32_t idx;
14013 	uint32_t srtt = 0, thresh = 0, ts_low = 0;
14014 
14015 	/* Return the next guy to be re-transmitted */
14016 	if (RB_EMPTY(&rack->r_ctl.rc_mtree)) {
14017 		return (NULL);
14018 	}
14019 	if (tp->t_flags & TF_SENTFIN) {
14020 		/* retran the end FIN? */
14021 		return (NULL);
14022 	}
14023 	/* ok lets look at this one */
14024 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
14025 	if (rsm && ((rsm->r_flags & RACK_ACKED) == 0)) {
14026 		goto check_it;
14027 	}
14028 	rsm = rack_find_lowest_rsm(rack);
14029 	if (rsm == NULL) {
14030 		return (NULL);
14031 	}
14032 check_it:
14033 	if (((rack->rc_tp->t_flags & TF_SACK_PERMIT) == 0) &&
14034 	    (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
14035 		/*
14036 		 * No sack so we automatically do the 3 strikes and
14037 		 * retransmit (no rack timer would be started).
14038 		 */
14039 
14040 		return (rsm);
14041 	}
14042 	if (rsm->r_flags & RACK_ACKED) {
14043 		return (NULL);
14044 	}
14045 	if (((rsm->r_flags & RACK_SACK_PASSED) == 0) &&
14046 	    (rsm->r_dupack < DUP_ACK_THRESHOLD)) {
14047 		/* Its not yet ready */
14048 		return (NULL);
14049 	}
14050 	srtt = rack_grab_rtt(tp, rack);
14051 	idx = rsm->r_rtr_cnt - 1;
14052 	ts_low = (uint32_t)rsm->r_tim_lastsent[idx];
14053 	thresh = rack_calc_thresh_rack(rack, srtt, tsused);
14054 	if ((tsused == ts_low) ||
14055 	    (TSTMP_LT(tsused, ts_low))) {
14056 		/* No time since sending */
14057 		return (NULL);
14058 	}
14059 	if ((tsused - ts_low) < thresh) {
14060 		/* It has not been long enough yet */
14061 		return (NULL);
14062 	}
14063 	if ((rsm->r_dupack >= DUP_ACK_THRESHOLD) ||
14064 	    ((rsm->r_flags & RACK_SACK_PASSED) &&
14065 	     (rack->sack_attack_disable == 0))) {
14066 		/*
14067 		 * We have passed the dup-ack threshold <or>
14068 		 * a SACK has indicated this is missing.
14069 		 * Note that if you are a declared attacker
14070 		 * it is only the dup-ack threshold that
14071 		 * will cause retransmits.
14072 		 */
14073 		/* log retransmit reason */
14074 		rack_log_retran_reason(rack, rsm, (tsused - ts_low), thresh, 1);
14075 		rack->r_fast_output = 0;
14076 		return (rsm);
14077 	}
14078 	return (NULL);
14079 }
14080 
14081 static void
14082 rack_log_pacing_delay_calc(struct tcp_rack *rack, uint32_t len, uint32_t slot,
14083 			   uint64_t bw_est, uint64_t bw, uint64_t len_time, int method,
14084 			   int line, struct rack_sendmap *rsm)
14085 {
14086 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
14087 		union tcp_log_stackspecific log;
14088 		struct timeval tv;
14089 
14090 		memset(&log, 0, sizeof(log));
14091 		log.u_bbr.flex1 = slot;
14092 		log.u_bbr.flex2 = len;
14093 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_min_segs;
14094 		log.u_bbr.flex4 = rack->r_ctl.rc_pace_max_segs;
14095 		log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ss;
14096 		log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_ca;
14097 		log.u_bbr.use_lt_bw = rack->rc_ack_can_sendout_data;
14098 		log.u_bbr.use_lt_bw <<= 1;
14099 		log.u_bbr.use_lt_bw |= rack->r_late;
14100 		log.u_bbr.use_lt_bw <<= 1;
14101 		log.u_bbr.use_lt_bw |= rack->r_early;
14102 		log.u_bbr.use_lt_bw <<= 1;
14103 		log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
14104 		log.u_bbr.use_lt_bw <<= 1;
14105 		log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
14106 		log.u_bbr.use_lt_bw <<= 1;
14107 		log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
14108 		log.u_bbr.use_lt_bw <<= 1;
14109 		log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
14110 		log.u_bbr.use_lt_bw <<= 1;
14111 		log.u_bbr.use_lt_bw |= rack->gp_ready;
14112 		log.u_bbr.pkt_epoch = line;
14113 		log.u_bbr.epoch = rack->r_ctl.rc_agg_delayed;
14114 		log.u_bbr.lt_epoch = rack->r_ctl.rc_agg_early;
14115 		log.u_bbr.applimited = rack->r_ctl.rack_per_of_gp_rec;
14116 		log.u_bbr.bw_inuse = bw_est;
14117 		log.u_bbr.delRate = bw;
14118 		if (rack->r_ctl.gp_bw == 0)
14119 			log.u_bbr.cur_del_rate = 0;
14120 		else
14121 			log.u_bbr.cur_del_rate = rack_get_bw(rack);
14122 		log.u_bbr.rttProp = len_time;
14123 		log.u_bbr.pkts_out = rack->r_ctl.rc_rack_min_rtt;
14124 		log.u_bbr.lost = rack->r_ctl.rc_probertt_sndmax_atexit;
14125 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
14126 		if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh) {
14127 			/* We are in slow start */
14128 			log.u_bbr.flex7 = 1;
14129 		} else {
14130 			/* we are on congestion avoidance */
14131 			log.u_bbr.flex7 = 0;
14132 		}
14133 		log.u_bbr.flex8 = method;
14134 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
14135 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
14136 		log.u_bbr.cwnd_gain = rack->rc_gp_saw_rec;
14137 		log.u_bbr.cwnd_gain <<= 1;
14138 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
14139 		log.u_bbr.cwnd_gain <<= 1;
14140 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
14141 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
14142 		    &rack->rc_inp->inp_socket->so_rcv,
14143 		    &rack->rc_inp->inp_socket->so_snd,
14144 		    BBR_LOG_HPTSI_CALC, 0,
14145 		    0, &log, false, &tv);
14146 	}
14147 }
14148 
14149 static uint32_t
14150 rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss)
14151 {
14152 	uint32_t new_tso, user_max;
14153 
14154 	user_max = rack->rc_user_set_max_segs * mss;
14155 	if (rack->rc_force_max_seg) {
14156 		return (user_max);
14157 	}
14158 	if (rack->use_fixed_rate &&
14159 	    ((rack->r_ctl.crte == NULL) ||
14160 	     (bw != rack->r_ctl.crte->rate))) {
14161 		/* Use the user mss since we are not exactly matched */
14162 		return (user_max);
14163 	}
14164 	new_tso = tcp_get_pacing_burst_size(rack->rc_tp, bw, mss, rack_pace_one_seg, rack->r_ctl.crte, NULL);
14165 	if (new_tso > user_max)
14166 		new_tso = user_max;
14167 	return (new_tso);
14168 }
14169 
14170 static int32_t
14171 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)
14172 {
14173 	uint64_t lentim, fill_bw;
14174 
14175 	/* Lets first see if we are full, if so continue with normal rate */
14176 	rack->r_via_fill_cw = 0;
14177 	if (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.cwnd_to_use)
14178 		return (slot);
14179 	if ((ctf_outstanding(rack->rc_tp) + (segsiz-1)) > rack->rc_tp->snd_wnd)
14180 		return (slot);
14181 	if (rack->r_ctl.rc_last_us_rtt == 0)
14182 		return (slot);
14183 	if (rack->rc_pace_fill_if_rttin_range &&
14184 	    (rack->r_ctl.rc_last_us_rtt >=
14185 	     (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack->rtt_limit_mul))) {
14186 		/* The rtt is huge, N * smallest, lets not fill */
14187 		return (slot);
14188 	}
14189 	/*
14190 	 * first lets calculate the b/w based on the last us-rtt
14191 	 * and the sndwnd.
14192 	 */
14193 	fill_bw = rack->r_ctl.cwnd_to_use;
14194 	/* Take the rwnd if its smaller */
14195 	if (fill_bw > rack->rc_tp->snd_wnd)
14196 		fill_bw = rack->rc_tp->snd_wnd;
14197 	if (rack->r_fill_less_agg) {
14198 		/*
14199 		 * Now take away the inflight (this will reduce our
14200 		 * aggressiveness and yeah, if we get that much out in 1RTT
14201 		 * we will have had acks come back and still be behind).
14202 		 */
14203 		fill_bw -= ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
14204 	}
14205 	/* Now lets make it into a b/w */
14206 	fill_bw *= (uint64_t)HPTS_USEC_IN_SEC;
14207 	fill_bw /= (uint64_t)rack->r_ctl.rc_last_us_rtt;
14208 	/* We are below the min b/w */
14209 	if (non_paced)
14210 		*rate_wanted = fill_bw;
14211 	if ((fill_bw < RACK_MIN_BW) || (fill_bw < *rate_wanted))
14212 		return (slot);
14213 	if (rack->r_ctl.bw_rate_cap && (fill_bw > rack->r_ctl.bw_rate_cap))
14214 		fill_bw = rack->r_ctl.bw_rate_cap;
14215 	rack->r_via_fill_cw = 1;
14216 	if (rack->r_rack_hw_rate_caps &&
14217 	    (rack->r_ctl.crte != NULL)) {
14218 		uint64_t high_rate;
14219 
14220 		high_rate = tcp_hw_highest_rate(rack->r_ctl.crte);
14221 		if (fill_bw > high_rate) {
14222 			/* We are capping bw at the highest rate table entry */
14223 			if (*rate_wanted > high_rate) {
14224 				/* The original rate was also capped */
14225 				rack->r_via_fill_cw = 0;
14226 			}
14227 			rack_log_hdwr_pacing(rack,
14228 					     fill_bw, high_rate, __LINE__,
14229 					     0, 3);
14230 			fill_bw = high_rate;
14231 			if (capped)
14232 				*capped = 1;
14233 		}
14234 	} else if ((rack->r_ctl.crte == NULL) &&
14235 		   (rack->rack_hdrw_pacing == 0) &&
14236 		   (rack->rack_hdw_pace_ena) &&
14237 		   rack->r_rack_hw_rate_caps &&
14238 		   (rack->rack_attempt_hdwr_pace == 0) &&
14239 		   (rack->rc_inp->inp_route.ro_nh != NULL) &&
14240 		   (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
14241 		/*
14242 		 * Ok we may have a first attempt that is greater than our top rate
14243 		 * lets check.
14244 		 */
14245 		uint64_t high_rate;
14246 
14247 		high_rate = tcp_hw_highest_rate_ifp(rack->rc_inp->inp_route.ro_nh->nh_ifp, rack->rc_inp);
14248 		if (high_rate) {
14249 			if (fill_bw > high_rate) {
14250 				fill_bw = high_rate;
14251 				if (capped)
14252 					*capped = 1;
14253 			}
14254 		}
14255 	}
14256 	/*
14257 	 * Ok fill_bw holds our mythical b/w to fill the cwnd
14258 	 * in a rtt, what does that time wise equate too?
14259 	 */
14260 	lentim = (uint64_t)(len) * (uint64_t)HPTS_USEC_IN_SEC;
14261 	lentim /= fill_bw;
14262 	*rate_wanted = fill_bw;
14263 	if (non_paced || (lentim < slot)) {
14264 		rack_log_pacing_delay_calc(rack, len, slot, fill_bw,
14265 					   0, lentim, 12, __LINE__, NULL);
14266 		return ((int32_t)lentim);
14267 	} else
14268 		return (slot);
14269 }
14270 
14271 static int32_t
14272 rack_get_pacing_delay(struct tcp_rack *rack, struct tcpcb *tp, uint32_t len, struct rack_sendmap *rsm, uint32_t segsiz)
14273 {
14274 	struct rack_sendmap *lrsm;
14275 	int32_t slot = 0;
14276 	int can_start_hw_pacing = 1;
14277 	int err;
14278 
14279 	if (rack->rc_always_pace == 0) {
14280 		/*
14281 		 * We use the most optimistic possible cwnd/srtt for
14282 		 * sending calculations. This will make our
14283 		 * calculation anticipate getting more through
14284 		 * quicker then possible. But thats ok we don't want
14285 		 * the peer to have a gap in data sending.
14286 		 */
14287 		uint32_t srtt, cwnd, tr_perms = 0;
14288 		int32_t reduce = 0;
14289 
14290 	old_method:
14291 		/*
14292 		 * We keep no precise pacing with the old method
14293 		 * instead we use the pacer to mitigate bursts.
14294 		 */
14295 		if (rack->r_ctl.rc_rack_min_rtt)
14296 			srtt = rack->r_ctl.rc_rack_min_rtt;
14297 		else
14298 			srtt = max(tp->t_srtt, 1);
14299 		if (rack->r_ctl.rc_rack_largest_cwnd)
14300 			cwnd = rack->r_ctl.rc_rack_largest_cwnd;
14301 		else
14302 			cwnd = rack->r_ctl.cwnd_to_use;
14303 		/* Inflate cwnd by 1000 so srtt of usecs is in ms */
14304 		tr_perms = (cwnd * 1000) / srtt;
14305 		if (tr_perms == 0) {
14306 			tr_perms = ctf_fixed_maxseg(tp);
14307 		}
14308 		/*
14309 		 * Calculate how long this will take to drain, if
14310 		 * the calculation comes out to zero, thats ok we
14311 		 * will use send_a_lot to possibly spin around for
14312 		 * more increasing tot_len_this_send to the point
14313 		 * that its going to require a pace, or we hit the
14314 		 * cwnd. Which in that case we are just waiting for
14315 		 * a ACK.
14316 		 */
14317 		slot = len / tr_perms;
14318 		/* Now do we reduce the time so we don't run dry? */
14319 		if (slot && rack_slot_reduction) {
14320 			reduce = (slot / rack_slot_reduction);
14321 			if (reduce < slot) {
14322 				slot -= reduce;
14323 			} else
14324 				slot = 0;
14325 		}
14326 		slot *= HPTS_USEC_IN_MSEC;
14327 		if (rsm == NULL) {
14328 			/*
14329 			 * We always consider ourselves app limited with old style
14330 			 * that are not retransmits. This could be the initial
14331 			 * measurement, but thats ok its all setup and specially
14332 			 * handled. If another send leaks out, then that too will
14333 			 * be mark app-limited.
14334 			 */
14335 			lrsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
14336 			if (lrsm && ((lrsm->r_flags & RACK_APP_LIMITED) == 0)) {
14337 				rack->r_ctl.rc_first_appl = lrsm;
14338 				lrsm->r_flags |= RACK_APP_LIMITED;
14339 				rack->r_ctl.rc_app_limited_cnt++;
14340 			}
14341 		}
14342 		if (rack->rc_pace_to_cwnd) {
14343 			uint64_t rate_wanted = 0;
14344 
14345 			slot = pace_to_fill_cwnd(rack, slot, len, segsiz, NULL, &rate_wanted, 1);
14346 			rack->rc_ack_can_sendout_data = 1;
14347 			rack_log_pacing_delay_calc(rack, len, slot, rate_wanted, 0, 0, 14, __LINE__, NULL);
14348 		} else
14349 			rack_log_pacing_delay_calc(rack, len, slot, tr_perms, reduce, 0, 7, __LINE__, NULL);
14350 	} else {
14351 		uint64_t bw_est, res, lentim, rate_wanted;
14352 		uint32_t orig_val, srtt, segs, oh;
14353 		int capped = 0;
14354 		int prev_fill;
14355 
14356 		if ((rack->r_rr_config == 1) && rsm) {
14357 			return (rack->r_ctl.rc_min_to);
14358 		}
14359 		if (rack->use_fixed_rate) {
14360 			rate_wanted = bw_est = rack_get_fixed_pacing_bw(rack);
14361 		} else if ((rack->r_ctl.init_rate == 0) &&
14362 #ifdef NETFLIX_PEAKRATE
14363 			   (rack->rc_tp->t_maxpeakrate == 0) &&
14364 #endif
14365 			   (rack->r_ctl.gp_bw == 0)) {
14366 			/* no way to yet do an estimate */
14367 			bw_est = rate_wanted = 0;
14368 		} else {
14369 			bw_est = rack_get_bw(rack);
14370 			rate_wanted = rack_get_output_bw(rack, bw_est, rsm, &capped);
14371 		}
14372 		if ((bw_est == 0) || (rate_wanted == 0) ||
14373 		    ((rack->gp_ready == 0) && (rack->use_fixed_rate == 0))) {
14374 			/*
14375 			 * No way yet to make a b/w estimate or
14376 			 * our raise is set incorrectly.
14377 			 */
14378 			goto old_method;
14379 		}
14380 		/* We need to account for all the overheads */
14381 		segs = (len + segsiz - 1) / segsiz;
14382 		/*
14383 		 * We need the diff between 1514 bytes (e-mtu with e-hdr)
14384 		 * and how much data we put in each packet. Yes this
14385 		 * means we may be off if we are larger than 1500 bytes
14386 		 * or smaller. But this just makes us more conservative.
14387 		 */
14388 		if (rack_hw_rate_min &&
14389 		    (bw_est < rack_hw_rate_min))
14390 			can_start_hw_pacing = 0;
14391 		if (ETHERNET_SEGMENT_SIZE > segsiz)
14392 			oh = ETHERNET_SEGMENT_SIZE - segsiz;
14393 		else
14394 			oh = 0;
14395 		segs *= oh;
14396 		lentim = (uint64_t)(len + segs) * (uint64_t)HPTS_USEC_IN_SEC;
14397 		res = lentim / rate_wanted;
14398 		slot = (uint32_t)res;
14399 		orig_val = rack->r_ctl.rc_pace_max_segs;
14400 		if (rack->r_ctl.crte == NULL) {
14401 			/*
14402 			 * Only do this if we are not hardware pacing
14403 			 * since if we are doing hw-pacing below we will
14404 			 * set make a call after setting up or changing
14405 			 * the rate.
14406 			 */
14407 			rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
14408 		} else if (rack->rc_inp->inp_snd_tag == NULL) {
14409 			/*
14410 			 * We lost our rate somehow, this can happen
14411 			 * if the interface changed underneath us.
14412 			 */
14413 			tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
14414 			rack->r_ctl.crte = NULL;
14415 			/* Lets re-allow attempting to setup pacing */
14416 			rack->rack_hdrw_pacing = 0;
14417 			rack->rack_attempt_hdwr_pace = 0;
14418 			rack_log_hdwr_pacing(rack,
14419 					     rate_wanted, bw_est, __LINE__,
14420 					     0, 6);
14421 		}
14422 		/* Did we change the TSO size, if so log it */
14423 		if (rack->r_ctl.rc_pace_max_segs != orig_val)
14424 			rack_log_pacing_delay_calc(rack, len, slot, orig_val, 0, 0, 15, __LINE__, NULL);
14425 		prev_fill = rack->r_via_fill_cw;
14426 		if ((rack->rc_pace_to_cwnd) &&
14427 		    (capped == 0) &&
14428 		    (rack->use_fixed_rate == 0) &&
14429 		    (rack->in_probe_rtt == 0) &&
14430 		    (IN_FASTRECOVERY(rack->rc_tp->t_flags) == 0)) {
14431 			/*
14432 			 * We want to pace at our rate *or* faster to
14433 			 * fill the cwnd to the max if its not full.
14434 			 */
14435 			slot = pace_to_fill_cwnd(rack, slot, (len+segs), segsiz, &capped, &rate_wanted, 0);
14436 		}
14437 		if ((rack->rc_inp->inp_route.ro_nh != NULL) &&
14438 		    (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
14439 			if ((rack->rack_hdw_pace_ena) &&
14440 			    (can_start_hw_pacing > 0) &&
14441 			    (rack->rack_hdrw_pacing == 0) &&
14442 			    (rack->rack_attempt_hdwr_pace == 0)) {
14443 				/*
14444 				 * Lets attempt to turn on hardware pacing
14445 				 * if we can.
14446 				 */
14447 				rack->rack_attempt_hdwr_pace = 1;
14448 				rack->r_ctl.crte = tcp_set_pacing_rate(rack->rc_tp,
14449 								       rack->rc_inp->inp_route.ro_nh->nh_ifp,
14450 								       rate_wanted,
14451 								       RS_PACING_GEQ,
14452 								       &err, &rack->r_ctl.crte_prev_rate);
14453 				if (rack->r_ctl.crte) {
14454 					rack->rack_hdrw_pacing = 1;
14455 					rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(tp, rate_wanted, segsiz,
14456 												 0, rack->r_ctl.crte,
14457 												 NULL);
14458 					rack_log_hdwr_pacing(rack,
14459 							     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
14460 							     err, 0);
14461 					rack->r_ctl.last_hw_bw_req = rate_wanted;
14462 				} else {
14463 					counter_u64_add(rack_hw_pace_init_fail, 1);
14464 				}
14465 			} else if (rack->rack_hdrw_pacing &&
14466 				   (rack->r_ctl.last_hw_bw_req != rate_wanted)) {
14467 				/* Do we need to adjust our rate? */
14468 				const struct tcp_hwrate_limit_table *nrte;
14469 
14470 				if (rack->r_up_only &&
14471 				    (rate_wanted < rack->r_ctl.crte->rate)) {
14472 					/**
14473 					 * We have four possible states here
14474 					 * having to do with the previous time
14475 					 * and this time.
14476 					 *   previous  |  this-time
14477 					 * A)     0      |     0   -- fill_cw not in the picture
14478 					 * B)     1      |     0   -- we were doing a fill-cw but now are not
14479 					 * C)     1      |     1   -- all rates from fill_cw
14480 					 * D)     0      |     1   -- we were doing non-fill and now we are filling
14481 					 *
14482 					 * For case A, C and D we don't allow a drop. But for
14483 					 * case B where we now our on our steady rate we do
14484 					 * allow a drop.
14485 					 *
14486 					 */
14487 					if (!((prev_fill == 1) && (rack->r_via_fill_cw == 0)))
14488 						goto done_w_hdwr;
14489 				}
14490 				if ((rate_wanted > rack->r_ctl.crte->rate) ||
14491 				    (rate_wanted <= rack->r_ctl.crte_prev_rate)) {
14492 					if (rack_hw_rate_to_low &&
14493 					    (bw_est < rack_hw_rate_to_low)) {
14494 						/*
14495 						 * The pacing rate is too low for hardware, but
14496 						 * do allow hardware pacing to be restarted.
14497 						 */
14498 						rack_log_hdwr_pacing(rack,
14499 							     bw_est, rack->r_ctl.crte->rate, __LINE__,
14500 							     0, 5);
14501 						tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
14502 						rack->r_ctl.crte = NULL;
14503 						rack->rack_attempt_hdwr_pace = 0;
14504 						rack->rack_hdrw_pacing = 0;
14505 						rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
14506 						goto done_w_hdwr;
14507 					}
14508 					nrte = tcp_chg_pacing_rate(rack->r_ctl.crte,
14509 								   rack->rc_tp,
14510 								   rack->rc_inp->inp_route.ro_nh->nh_ifp,
14511 								   rate_wanted,
14512 								   RS_PACING_GEQ,
14513 								   &err, &rack->r_ctl.crte_prev_rate);
14514 					if (nrte == NULL) {
14515 						/* Lost the rate */
14516 						rack->rack_hdrw_pacing = 0;
14517 						rack->r_ctl.crte = NULL;
14518 						rack_log_hdwr_pacing(rack,
14519 								     rate_wanted, 0, __LINE__,
14520 								     err, 1);
14521 						rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
14522 						counter_u64_add(rack_hw_pace_lost, 1);
14523 					} else if (nrte != rack->r_ctl.crte) {
14524 						rack->r_ctl.crte = nrte;
14525 						rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(tp, rate_wanted,
14526 													 segsiz, 0,
14527 													 rack->r_ctl.crte,
14528 													 NULL);
14529 						rack_log_hdwr_pacing(rack,
14530 								     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
14531 								     err, 2);
14532 						rack->r_ctl.last_hw_bw_req = rate_wanted;
14533 					}
14534 				} else {
14535 					/* We just need to adjust the segment size */
14536 					rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
14537 					rack_log_hdwr_pacing(rack,
14538 							     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
14539 							     0, 4);
14540 					rack->r_ctl.last_hw_bw_req = rate_wanted;
14541 				}
14542 			}
14543 		}
14544 		if ((rack->r_ctl.crte != NULL) &&
14545 		    (rack->r_ctl.crte->rate == rate_wanted)) {
14546 			/*
14547 			 * We need to add a extra if the rates
14548 			 * are exactly matched. The idea is
14549 			 * we want the software to make sure the
14550 			 * queue is empty before adding more, this
14551 			 * gives us N MSS extra pace times where
14552 			 * N is our sysctl
14553 			 */
14554 			slot += (rack->r_ctl.crte->time_between * rack_hw_pace_extra_slots);
14555 		}
14556 done_w_hdwr:
14557 		if (rack_limit_time_with_srtt &&
14558 		    (rack->use_fixed_rate == 0) &&
14559 #ifdef NETFLIX_PEAKRATE
14560 		    (rack->rc_tp->t_maxpeakrate == 0) &&
14561 #endif
14562 		    (rack->rack_hdrw_pacing == 0)) {
14563 			/*
14564 			 * Sanity check, we do not allow the pacing delay
14565 			 * to be longer than the SRTT of the path. If it is
14566 			 * a slow path, then adding a packet should increase
14567 			 * the RTT and compensate for this i.e. the srtt will
14568 			 * be greater so the allowed pacing time will be greater.
14569 			 *
14570 			 * Note this restriction is not for where a peak rate
14571 			 * is set, we are doing fixed pacing or hardware pacing.
14572 			 */
14573 			if (rack->rc_tp->t_srtt)
14574 				srtt = rack->rc_tp->t_srtt;
14575 			else
14576 				srtt = RACK_INITIAL_RTO * HPTS_USEC_IN_MSEC;	/* its in ms convert */
14577 			if (srtt < slot) {
14578 				rack_log_pacing_delay_calc(rack, srtt, slot, rate_wanted, bw_est, lentim, 99, __LINE__, NULL);
14579 				slot = srtt;
14580 			}
14581 		}
14582 		rack_log_pacing_delay_calc(rack, len, slot, rate_wanted, bw_est, lentim, 2, __LINE__, rsm);
14583 	}
14584 	if (rack->r_ctl.crte && (rack->r_ctl.crte->rs_num_enobufs > 0)) {
14585 		/*
14586 		 * If this rate is seeing enobufs when it
14587 		 * goes to send then either the nic is out
14588 		 * of gas or we are mis-estimating the time
14589 		 * somehow and not letting the queue empty
14590 		 * completely. Lets add to the pacing time.
14591 		 */
14592 		int hw_boost_delay;
14593 
14594 		hw_boost_delay = rack->r_ctl.crte->time_between * rack_enobuf_hw_boost_mult;
14595 		if (hw_boost_delay > rack_enobuf_hw_max)
14596 			hw_boost_delay = rack_enobuf_hw_max;
14597 		else if (hw_boost_delay < rack_enobuf_hw_min)
14598 			hw_boost_delay = rack_enobuf_hw_min;
14599 		slot += hw_boost_delay;
14600 	}
14601 	if (slot)
14602 		counter_u64_add(rack_calc_nonzero, 1);
14603 	else
14604 		counter_u64_add(rack_calc_zero, 1);
14605 	return (slot);
14606 }
14607 
14608 static void
14609 rack_start_gp_measurement(struct tcpcb *tp, struct tcp_rack *rack,
14610     tcp_seq startseq, uint32_t sb_offset)
14611 {
14612 	struct rack_sendmap *my_rsm = NULL;
14613 	struct rack_sendmap fe;
14614 
14615 	if (tp->t_state < TCPS_ESTABLISHED) {
14616 		/*
14617 		 * We don't start any measurements if we are
14618 		 * not at least established.
14619 		 */
14620 		return;
14621 	}
14622 	tp->t_flags |= TF_GPUTINPROG;
14623 	rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
14624 	rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
14625 	tp->gput_seq = startseq;
14626 	rack->app_limited_needs_set = 0;
14627 	if (rack->in_probe_rtt)
14628 		rack->measure_saw_probe_rtt = 1;
14629 	else if ((rack->measure_saw_probe_rtt) &&
14630 		 (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
14631 		rack->measure_saw_probe_rtt = 0;
14632 	if (rack->rc_gp_filled)
14633 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
14634 	else {
14635 		/* Special case initial measurement */
14636 		struct timeval tv;
14637 
14638 		tp->gput_ts = tcp_get_usecs(&tv);
14639 		rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
14640 	}
14641 	/*
14642 	 * We take a guess out into the future,
14643 	 * if we have no measurement and no
14644 	 * initial rate, we measure the first
14645 	 * initial-windows worth of data to
14646 	 * speed up getting some GP measurement and
14647 	 * thus start pacing.
14648 	 */
14649 	if ((rack->rc_gp_filled == 0) && (rack->r_ctl.init_rate == 0)) {
14650 		rack->app_limited_needs_set = 1;
14651 		tp->gput_ack = startseq + max(rc_init_window(rack),
14652 					      (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
14653 		rack_log_pacing_delay_calc(rack,
14654 					   tp->gput_seq,
14655 					   tp->gput_ack,
14656 					   0,
14657 					   tp->gput_ts,
14658 					   rack->r_ctl.rc_app_limited_cnt,
14659 					   9,
14660 					   __LINE__, NULL);
14661 		return;
14662 	}
14663 	if (sb_offset) {
14664 		/*
14665 		 * We are out somewhere in the sb
14666 		 * can we use the already outstanding data?
14667 		 */
14668 
14669 		if (rack->r_ctl.rc_app_limited_cnt == 0) {
14670 			/*
14671 			 * Yes first one is good and in this case
14672 			 * the tp->gput_ts is correctly set based on
14673 			 * the last ack that arrived (no need to
14674 			 * set things up when an ack comes in).
14675 			 */
14676 			my_rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
14677 			if ((my_rsm == NULL) ||
14678 			    (my_rsm->r_rtr_cnt != 1)) {
14679 				/* retransmission? */
14680 				goto use_latest;
14681 			}
14682 		} else {
14683 			if (rack->r_ctl.rc_first_appl == NULL) {
14684 				/*
14685 				 * If rc_first_appl is NULL
14686 				 * then the cnt should be 0.
14687 				 * This is probably an error, maybe
14688 				 * a KASSERT would be approprate.
14689 				 */
14690 				goto use_latest;
14691 			}
14692 			/*
14693 			 * If we have a marker pointer to the last one that is
14694 			 * app limited we can use that, but we need to set
14695 			 * things up so that when it gets ack'ed we record
14696 			 * the ack time (if its not already acked).
14697 			 */
14698 			rack->app_limited_needs_set = 1;
14699 			/*
14700 			 * We want to get to the rsm that is either
14701 			 * next with space i.e. over 1 MSS or the one
14702 			 * after that (after the app-limited).
14703 			 */
14704 			my_rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree,
14705 					 rack->r_ctl.rc_first_appl);
14706 			if (my_rsm) {
14707 				if ((my_rsm->r_end - my_rsm->r_start) <= ctf_fixed_maxseg(tp))
14708 					/* Have to use the next one */
14709 					my_rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree,
14710 							 my_rsm);
14711 				else {
14712 					/* Use after the first MSS of it is acked */
14713 					tp->gput_seq = my_rsm->r_start + ctf_fixed_maxseg(tp);
14714 					goto start_set;
14715 				}
14716 			}
14717 			if ((my_rsm == NULL) ||
14718 			    (my_rsm->r_rtr_cnt != 1)) {
14719 				/*
14720 				 * Either its a retransmit or
14721 				 * the last is the app-limited one.
14722 				 */
14723 				goto use_latest;
14724 			}
14725 		}
14726 		tp->gput_seq = my_rsm->r_start;
14727 start_set:
14728 		if (my_rsm->r_flags & RACK_ACKED) {
14729 			/*
14730 			 * This one has been acked use the arrival ack time
14731 			 */
14732 			tp->gput_ts = (uint32_t)my_rsm->r_ack_arrival;
14733 			rack->app_limited_needs_set = 0;
14734 		}
14735 		rack->r_ctl.rc_gp_output_ts = my_rsm->r_tim_lastsent[(my_rsm->r_rtr_cnt-1)];
14736 		tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
14737 		rack_log_pacing_delay_calc(rack,
14738 					   tp->gput_seq,
14739 					   tp->gput_ack,
14740 					   (uint64_t)my_rsm,
14741 					   tp->gput_ts,
14742 					   rack->r_ctl.rc_app_limited_cnt,
14743 					   9,
14744 					   __LINE__, NULL);
14745 		return;
14746 	}
14747 
14748 use_latest:
14749 	/*
14750 	 * We don't know how long we may have been
14751 	 * idle or if this is the first-send. Lets
14752 	 * setup the flag so we will trim off
14753 	 * the first ack'd data so we get a true
14754 	 * measurement.
14755 	 */
14756 	rack->app_limited_needs_set = 1;
14757 	tp->gput_ack = startseq + rack_get_measure_window(tp, rack);
14758 	/* Find this guy so we can pull the send time */
14759 	fe.r_start = startseq;
14760 	my_rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
14761 	if (my_rsm) {
14762 		rack->r_ctl.rc_gp_output_ts = my_rsm->r_tim_lastsent[(my_rsm->r_rtr_cnt-1)];
14763 		if (my_rsm->r_flags & RACK_ACKED) {
14764 			/*
14765 			 * Unlikely since its probably what was
14766 			 * just transmitted (but I am paranoid).
14767 			 */
14768 			tp->gput_ts = (uint32_t)my_rsm->r_ack_arrival;
14769 			rack->app_limited_needs_set = 0;
14770 		}
14771 		if (SEQ_LT(my_rsm->r_start, tp->gput_seq)) {
14772 			/* This also is unlikely */
14773 			tp->gput_seq = my_rsm->r_start;
14774 		}
14775 	} else {
14776 		/*
14777 		 * TSNH unless we have some send-map limit,
14778 		 * and even at that it should not be hitting
14779 		 * that limit (we should have stopped sending).
14780 		 */
14781 		struct timeval tv;
14782 
14783 		microuptime(&tv);
14784 		rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
14785 	}
14786 	rack_log_pacing_delay_calc(rack,
14787 				   tp->gput_seq,
14788 				   tp->gput_ack,
14789 				   (uint64_t)my_rsm,
14790 				   tp->gput_ts,
14791 				   rack->r_ctl.rc_app_limited_cnt,
14792 				   9, __LINE__, NULL);
14793 }
14794 
14795 static inline uint32_t
14796 rack_what_can_we_send(struct tcpcb *tp, struct tcp_rack *rack,  uint32_t cwnd_to_use,
14797     uint32_t avail, int32_t sb_offset)
14798 {
14799 	uint32_t len;
14800 	uint32_t sendwin;
14801 
14802 	if (tp->snd_wnd > cwnd_to_use)
14803 		sendwin = cwnd_to_use;
14804 	else
14805 		sendwin = tp->snd_wnd;
14806 	if (ctf_outstanding(tp) >= tp->snd_wnd) {
14807 		/* We never want to go over our peers rcv-window */
14808 		len = 0;
14809 	} else {
14810 		uint32_t flight;
14811 
14812 		flight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
14813 		if (flight >= sendwin) {
14814 			/*
14815 			 * We have in flight what we are allowed by cwnd (if
14816 			 * it was rwnd blocking it would have hit above out
14817 			 * >= tp->snd_wnd).
14818 			 */
14819 			return (0);
14820 		}
14821 		len = sendwin - flight;
14822 		if ((len + ctf_outstanding(tp)) > tp->snd_wnd) {
14823 			/* We would send too much (beyond the rwnd) */
14824 			len = tp->snd_wnd - ctf_outstanding(tp);
14825 		}
14826 		if ((len + sb_offset) > avail) {
14827 			/*
14828 			 * We don't have that much in the SB, how much is
14829 			 * there?
14830 			 */
14831 			len = avail - sb_offset;
14832 		}
14833 	}
14834 	return (len);
14835 }
14836 
14837 static void
14838 rack_log_fsb(struct tcp_rack *rack, struct tcpcb *tp, struct socket *so, uint32_t flags,
14839 	     unsigned ipoptlen, int32_t orig_len, int32_t len, int error,
14840 	     int rsm_is_null, int optlen, int line, uint16_t mode)
14841 {
14842 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
14843 		union tcp_log_stackspecific log;
14844 		struct timeval tv;
14845 
14846 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
14847 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
14848 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
14849 		log.u_bbr.flex1 = error;
14850 		log.u_bbr.flex2 = flags;
14851 		log.u_bbr.flex3 = rsm_is_null;
14852 		log.u_bbr.flex4 = ipoptlen;
14853 		log.u_bbr.flex5 = tp->rcv_numsacks;
14854 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
14855 		log.u_bbr.flex7 = optlen;
14856 		log.u_bbr.flex8 = rack->r_fsb_inited;
14857 		log.u_bbr.applimited = rack->r_fast_output;
14858 		log.u_bbr.bw_inuse = rack_get_bw(rack);
14859 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
14860 		log.u_bbr.cwnd_gain = mode;
14861 		log.u_bbr.pkts_out = orig_len;
14862 		log.u_bbr.lt_epoch = len;
14863 		log.u_bbr.delivered = line;
14864 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
14865 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
14866 		tcp_log_event_(tp, NULL, &so->so_rcv, &so->so_snd, TCP_LOG_FSB, 0,
14867 			       len, &log, false, NULL, NULL, 0, &tv);
14868 	}
14869 }
14870 
14871 
14872 static struct mbuf *
14873 rack_fo_base_copym(struct mbuf *the_m, uint32_t the_off, int32_t *plen,
14874 		   struct rack_fast_send_blk *fsb,
14875 		   int32_t seglimit, int32_t segsize)
14876 {
14877 #ifdef KERN_TLS
14878 	struct ktls_session *tls, *ntls;
14879 	struct mbuf *start;
14880 #endif
14881 	struct mbuf *m, *n, **np, *smb;
14882 	struct mbuf *top;
14883 	int32_t off, soff;
14884 	int32_t len = *plen;
14885 	int32_t fragsize;
14886 	int32_t len_cp = 0;
14887 	uint32_t mlen, frags;
14888 
14889 	soff = off = the_off;
14890 	smb = m = the_m;
14891 	np = &top;
14892 	top = NULL;
14893 #ifdef KERN_TLS
14894 	if (hw_tls && (m->m_flags & M_EXTPG))
14895 		tls = m->m_epg_tls;
14896 	else
14897 		tls = NULL;
14898 	start = m;
14899 #endif
14900 	while (len > 0) {
14901 		if (m == NULL) {
14902 			*plen = len_cp;
14903 			break;
14904 		}
14905 #ifdef KERN_TLS
14906 		if (hw_tls) {
14907 			if (m->m_flags & M_EXTPG)
14908 				ntls = m->m_epg_tls;
14909 			else
14910 				ntls = NULL;
14911 
14912 			/*
14913 			 * Avoid mixing TLS records with handshake
14914 			 * data or TLS records from different
14915 			 * sessions.
14916 			 */
14917 			if (tls != ntls) {
14918 				MPASS(m != start);
14919 				*plen = len_cp;
14920 				break;
14921 			}
14922 		}
14923 #endif
14924 		mlen = min(len, m->m_len - off);
14925 		if (seglimit) {
14926 			/*
14927 			 * For M_EXTPG mbufs, add 3 segments
14928 			 * + 1 in case we are crossing page boundaries
14929 			 * + 2 in case the TLS hdr/trailer are used
14930 			 * It is cheaper to just add the segments
14931 			 * than it is to take the cache miss to look
14932 			 * at the mbuf ext_pgs state in detail.
14933 			 */
14934 			if (m->m_flags & M_EXTPG) {
14935 				fragsize = min(segsize, PAGE_SIZE);
14936 				frags = 3;
14937 			} else {
14938 				fragsize = segsize;
14939 				frags = 0;
14940 			}
14941 
14942 			/* Break if we really can't fit anymore. */
14943 			if ((frags + 1) >= seglimit) {
14944 				*plen =	len_cp;
14945 				break;
14946 			}
14947 
14948 			/*
14949 			 * Reduce size if you can't copy the whole
14950 			 * mbuf. If we can't copy the whole mbuf, also
14951 			 * adjust len so the loop will end after this
14952 			 * mbuf.
14953 			 */
14954 			if ((frags + howmany(mlen, fragsize)) >= seglimit) {
14955 				mlen = (seglimit - frags - 1) * fragsize;
14956 				len = mlen;
14957 				*plen = len_cp + len;
14958 			}
14959 			frags += howmany(mlen, fragsize);
14960 			if (frags == 0)
14961 				frags++;
14962 			seglimit -= frags;
14963 			KASSERT(seglimit > 0,
14964 			    ("%s: seglimit went too low", __func__));
14965 		}
14966 		n = m_get(M_NOWAIT, m->m_type);
14967 		*np = n;
14968 		if (n == NULL)
14969 			goto nospace;
14970 		n->m_len = mlen;
14971 		soff += mlen;
14972 		len_cp += n->m_len;
14973 		if (m->m_flags & (M_EXT|M_EXTPG)) {
14974 			n->m_data = m->m_data + off;
14975 			mb_dupcl(n, m);
14976 		} else {
14977 			bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t),
14978 			    (u_int)n->m_len);
14979 		}
14980 		len -= n->m_len;
14981 		off = 0;
14982 		m = m->m_next;
14983 		np = &n->m_next;
14984 		if (len || (soff == smb->m_len)) {
14985 			/*
14986 			 * We have more so we move forward  or
14987 			 * we have consumed the entire mbuf and
14988 			 * len has fell to 0.
14989 			 */
14990 			soff = 0;
14991 			smb = m;
14992 		}
14993 
14994 	}
14995 	if (fsb != NULL) {
14996 		fsb->m = smb;
14997 		fsb->off = soff;
14998 		if (smb) {
14999 			/*
15000 			 * Save off the size of the mbuf. We do
15001 			 * this so that we can recognize when it
15002 			 * has been trimmed by sbcut() as acks
15003 			 * come in.
15004 			 */
15005 			fsb->o_m_len = smb->m_len;
15006 		} else {
15007 			/*
15008 			 * This is the case where the next mbuf went to NULL. This
15009 			 * means with this copy we have sent everything in the sb.
15010 			 * In theory we could clear the fast_output flag, but lets
15011 			 * not since its possible that we could get more added
15012 			 * and acks that call the extend function which would let
15013 			 * us send more.
15014 			 */
15015 			fsb->o_m_len = 0;
15016 		}
15017 	}
15018 	return (top);
15019 nospace:
15020 	if (top)
15021 		m_freem(top);
15022 	return (NULL);
15023 
15024 }
15025 
15026 /*
15027  * This is a copy of m_copym(), taking the TSO segment size/limit
15028  * constraints into account, and advancing the sndptr as it goes.
15029  */
15030 static struct mbuf *
15031 rack_fo_m_copym(struct tcp_rack *rack, int32_t *plen,
15032 		int32_t seglimit, int32_t segsize, struct mbuf **s_mb, int *s_soff)
15033 {
15034 	struct mbuf *m, *n;
15035 	int32_t soff;
15036 
15037 	soff = rack->r_ctl.fsb.off;
15038 	m = rack->r_ctl.fsb.m;
15039 	if (rack->r_ctl.fsb.o_m_len != m->m_len) {
15040 		/*
15041 		 * The mbuf had the front of it chopped off by an ack
15042 		 * we need to adjust the soff/off by that difference.
15043 		 */
15044 		uint32_t delta;
15045 
15046 		delta = rack->r_ctl.fsb.o_m_len - m->m_len;
15047 		soff -= delta;
15048 	}
15049 	KASSERT(soff >= 0, ("%s, negative off %d", __FUNCTION__, soff));
15050 	KASSERT(*plen >= 0, ("%s, negative len %d", __FUNCTION__, *plen));
15051 	KASSERT(soff < m->m_len, ("%s rack:%p len:%u m:%p m->m_len:%u < off?",
15052 				 __FUNCTION__,
15053 				 rack, *plen, m, m->m_len));
15054 	/* Save off the right location before we copy and advance */
15055 	*s_soff = soff;
15056 	*s_mb = rack->r_ctl.fsb.m;
15057 	n = rack_fo_base_copym(m, soff, plen,
15058 			       &rack->r_ctl.fsb,
15059 			       seglimit, segsize);
15060 	return (n);
15061 }
15062 
15063 static int
15064 rack_fast_rsm_output(struct tcpcb *tp, struct tcp_rack *rack, struct rack_sendmap *rsm,
15065 		     uint64_t ts_val, uint32_t cts, uint32_t ms_cts, struct timeval *tv, int len)
15066 {
15067 	/*
15068 	 * Enter the fast retransmit path. We are given that a sched_pin is
15069 	 * in place (if accounting is compliled in) and the cycle count taken
15070 	 * at the entry is in the ts_val. The concept her is that the rsm
15071 	 * now holds the mbuf offsets and such so we can directly transmit
15072 	 * without a lot of overhead, the len field is already set for
15073 	 * us to prohibit us from sending too much (usually its 1MSS).
15074 	 */
15075 	struct ip *ip = NULL;
15076 	struct udphdr *udp = NULL;
15077 	struct tcphdr *th = NULL;
15078 	struct mbuf *m = NULL;
15079 	struct inpcb *inp;
15080 	uint8_t *cpto;
15081 	struct tcp_log_buffer *lgb;
15082 #ifdef TCP_ACCOUNTING
15083 	uint64_t crtsc;
15084 	int cnt_thru = 1;
15085 #endif
15086 	int doing_tlp = 0;
15087 	struct tcpopt to;
15088 	u_char opt[TCP_MAXOLEN];
15089 	uint32_t hdrlen, optlen;
15090 	int32_t slot, segsiz, max_val, tso = 0, error, flags, ulen = 0;
15091 	uint32_t us_cts;
15092 	uint32_t if_hw_tsomaxsegcount = 0, startseq;
15093 	uint32_t if_hw_tsomaxsegsize;
15094 
15095 #ifdef INET6
15096 	struct ip6_hdr *ip6 = NULL;
15097 
15098 	if (rack->r_is_v6) {
15099 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
15100 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
15101 	} else
15102 #endif				/* INET6 */
15103 	{
15104 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
15105 		hdrlen = sizeof(struct tcpiphdr);
15106 	}
15107 	if (tp->t_port && (V_tcp_udp_tunneling_port == 0)) {
15108 		goto failed;
15109 	}
15110 	if (rsm->r_flags & RACK_TLP)
15111 		doing_tlp = 1;
15112 	startseq = rsm->r_start;
15113 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
15114 	inp = rack->rc_inp;
15115 	to.to_flags = 0;
15116 	flags = tcp_outflags[tp->t_state];
15117 	if (flags & (TH_SYN|TH_RST)) {
15118 		goto failed;
15119 	}
15120 	if (rsm->r_flags & RACK_HAS_FIN) {
15121 		/* We can't send a FIN here */
15122 		goto failed;
15123 	}
15124 	if (flags & TH_FIN) {
15125 		/* We never send a FIN */
15126 		flags &= ~TH_FIN;
15127 	}
15128 	if (tp->t_flags & TF_RCVD_TSTMP) {
15129 		to.to_tsval = ms_cts + tp->ts_offset;
15130 		to.to_tsecr = tp->ts_recent;
15131 		to.to_flags = TOF_TS;
15132 	}
15133 	optlen = tcp_addoptions(&to, opt);
15134 	hdrlen += optlen;
15135 	udp = rack->r_ctl.fsb.udp;
15136 	if (udp)
15137 		hdrlen += sizeof(struct udphdr);
15138 	if (rack->r_ctl.rc_pace_max_segs)
15139 		max_val = rack->r_ctl.rc_pace_max_segs;
15140 	else if (rack->rc_user_set_max_segs)
15141 		max_val = rack->rc_user_set_max_segs * segsiz;
15142 	else
15143 		max_val = len;
15144 	if ((tp->t_flags & TF_TSO) &&
15145 	    V_tcp_do_tso &&
15146 	    (len > segsiz) &&
15147 	    (tp->t_port == 0))
15148 		tso = 1;
15149 #ifdef INET6
15150 	if (MHLEN < hdrlen + max_linkhdr)
15151 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
15152 	else
15153 #endif
15154 		m = m_gethdr(M_NOWAIT, MT_DATA);
15155 	if (m == NULL)
15156 		goto failed;
15157 	m->m_data += max_linkhdr;
15158 	m->m_len = hdrlen;
15159 	th = rack->r_ctl.fsb.th;
15160 	/* Establish the len to send */
15161 	if (len > max_val)
15162 		len = max_val;
15163 	if ((tso) && (len + optlen > tp->t_maxseg)) {
15164 		uint32_t if_hw_tsomax;
15165 		int32_t max_len;
15166 
15167 		/* extract TSO information */
15168 		if_hw_tsomax = tp->t_tsomax;
15169 		if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
15170 		if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
15171 		/*
15172 		 * Check if we should limit by maximum payload
15173 		 * length:
15174 		 */
15175 		if (if_hw_tsomax != 0) {
15176 			/* compute maximum TSO length */
15177 			max_len = (if_hw_tsomax - hdrlen -
15178 				   max_linkhdr);
15179 			if (max_len <= 0) {
15180 				goto failed;
15181 			} else if (len > max_len) {
15182 				len = max_len;
15183 			}
15184 		}
15185 		if (len <= segsiz) {
15186 			/*
15187 			 * In case there are too many small fragments don't
15188 			 * use TSO:
15189 			 */
15190 			tso = 0;
15191 		}
15192 	} else {
15193 		tso = 0;
15194 	}
15195 	if ((tso == 0) && (len > segsiz))
15196 		len = segsiz;
15197 	us_cts = tcp_get_usecs(tv);
15198 	if ((len == 0) ||
15199 	    (len <= MHLEN - hdrlen - max_linkhdr)) {
15200 		goto failed;
15201 	}
15202 	th->th_seq = htonl(rsm->r_start);
15203 	th->th_ack = htonl(tp->rcv_nxt);
15204 	/*
15205 	 * The PUSH bit should only be applied
15206 	 * if the full retransmission is made. If
15207 	 * we are sending less than this is the
15208 	 * left hand edge and should not have
15209 	 * the PUSH bit.
15210 	 */
15211 	if ((rsm->r_flags & RACK_HAD_PUSH) &&
15212 	    (len == (rsm->r_end - rsm->r_start)))
15213 		flags |= TH_PUSH;
15214 	th->th_flags = flags;
15215 	th->th_win = htons((u_short)(rack->r_ctl.fsb.recwin >> tp->rcv_scale));
15216 	if (th->th_win == 0) {
15217 		tp->t_sndzerowin++;
15218 		tp->t_flags |= TF_RXWIN0SENT;
15219 	} else
15220 		tp->t_flags &= ~TF_RXWIN0SENT;
15221 	if (rsm->r_flags & RACK_TLP) {
15222 		/*
15223 		 * TLP should not count in retran count, but
15224 		 * in its own bin
15225 		 */
15226 		counter_u64_add(rack_tlp_retran, 1);
15227 		counter_u64_add(rack_tlp_retran_bytes, len);
15228 	} else {
15229 		tp->t_sndrexmitpack++;
15230 		KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
15231 		KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
15232 	}
15233 #ifdef STATS
15234 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
15235 				 len);
15236 #endif
15237 	if (rsm->m == NULL)
15238 		goto failed;
15239 	if (rsm->orig_m_len != rsm->m->m_len) {
15240 		/* Fix up the orig_m_len and possibly the mbuf offset */
15241 		rack_adjust_orig_mlen(rsm);
15242 	}
15243 	m->m_next = rack_fo_base_copym(rsm->m, rsm->soff, &len, NULL, if_hw_tsomaxsegcount, if_hw_tsomaxsegsize);
15244 	if (len <= segsiz) {
15245 		/*
15246 		 * Must have ran out of mbufs for the copy
15247 		 * shorten it to no longer need tso. Lets
15248 		 * not put on sendalot since we are low on
15249 		 * mbufs.
15250 		 */
15251 		tso = 0;
15252 	}
15253 	if ((m->m_next == NULL) || (len <= 0)){
15254 		goto failed;
15255 	}
15256 	if (udp) {
15257 		if (rack->r_is_v6)
15258 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
15259 		else
15260 			ulen = hdrlen + len - sizeof(struct ip);
15261 		udp->uh_ulen = htons(ulen);
15262 	}
15263 	m->m_pkthdr.rcvif = (struct ifnet *)0;
15264 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
15265 #ifdef INET6
15266 	if (rack->r_is_v6) {
15267 		if (tp->t_port) {
15268 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
15269 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
15270 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
15271 			th->th_sum = htons(0);
15272 			UDPSTAT_INC(udps_opackets);
15273 		} else {
15274 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
15275 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
15276 			th->th_sum = in6_cksum_pseudo(ip6,
15277 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
15278 						      0);
15279 		}
15280 	}
15281 #endif
15282 #if defined(INET6) && defined(INET)
15283 	else
15284 #endif
15285 #ifdef INET
15286 	{
15287 		if (tp->t_port) {
15288 			m->m_pkthdr.csum_flags = CSUM_UDP;
15289 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
15290 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
15291 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
15292 			th->th_sum = htons(0);
15293 			UDPSTAT_INC(udps_opackets);
15294 		} else {
15295 			m->m_pkthdr.csum_flags = CSUM_TCP;
15296 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
15297 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
15298 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
15299 									IPPROTO_TCP + len + optlen));
15300 		}
15301 		/* IP version must be set here for ipv4/ipv6 checking later */
15302 		KASSERT(ip->ip_v == IPVERSION,
15303 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
15304 	}
15305 #endif
15306 	if (tso) {
15307 		KASSERT(len > tp->t_maxseg - optlen,
15308 			("%s: len <= tso_segsz tp:%p", __func__, tp));
15309 		m->m_pkthdr.csum_flags |= CSUM_TSO;
15310 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
15311 	}
15312 #ifdef INET6
15313 	if (rack->r_is_v6) {
15314 		ip6->ip6_hlim = rack->r_ctl.fsb.hoplimit;
15315 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
15316 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
15317 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
15318 		else
15319 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
15320 	}
15321 #endif
15322 #if defined(INET) && defined(INET6)
15323 	else
15324 #endif
15325 #ifdef INET
15326 	{
15327 		ip->ip_len = htons(m->m_pkthdr.len);
15328 		ip->ip_ttl = rack->r_ctl.fsb.hoplimit;
15329 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
15330 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
15331 			if (tp->t_port == 0 || len < V_tcp_minmss) {
15332 				ip->ip_off |= htons(IP_DF);
15333 			}
15334 		} else {
15335 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
15336 		}
15337 	}
15338 #endif
15339 	/* Time to copy in our header */
15340 	cpto = mtod(m, uint8_t *);
15341 	memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
15342 	th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
15343 	if (optlen) {
15344 		bcopy(opt, th + 1, optlen);
15345 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
15346 	} else {
15347 		th->th_off = sizeof(struct tcphdr) >> 2;
15348 	}
15349 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
15350 		union tcp_log_stackspecific log;
15351 
15352 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
15353 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
15354 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
15355 		if (rack->rack_no_prr)
15356 			log.u_bbr.flex1 = 0;
15357 		else
15358 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
15359 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
15360 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
15361 		log.u_bbr.flex4 = max_val;
15362 		log.u_bbr.flex5 = 0;
15363 		/* Save off the early/late values */
15364 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
15365 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
15366 		log.u_bbr.bw_inuse = rack_get_bw(rack);
15367 		log.u_bbr.flex8 = 1;
15368 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
15369 		log.u_bbr.flex7 = 55;
15370 		log.u_bbr.pkts_out = tp->t_maxseg;
15371 		log.u_bbr.timeStamp = cts;
15372 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
15373 		log.u_bbr.lt_epoch = rack->r_ctl.cwnd_to_use;
15374 		log.u_bbr.delivered = 0;
15375 		lgb = tcp_log_event_(tp, th, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
15376 				     len, &log, false, NULL, NULL, 0, tv);
15377 	} else
15378 		lgb = NULL;
15379 #ifdef INET6
15380 	if (rack->r_is_v6) {
15381 		error = ip6_output(m, NULL,
15382 				   &inp->inp_route6,
15383 				   0, NULL, NULL, inp);
15384 	}
15385 #endif
15386 #if defined(INET) && defined(INET6)
15387 	else
15388 #endif
15389 #ifdef INET
15390 	{
15391 		error = ip_output(m, NULL,
15392 				  &inp->inp_route,
15393 				  0, 0, inp);
15394 	}
15395 #endif
15396 	m = NULL;
15397 	if (lgb) {
15398 		lgb->tlb_errno = error;
15399 		lgb = NULL;
15400 	}
15401 	if (error) {
15402 		goto failed;
15403 	}
15404 	rack_log_output(tp, &to, len, rsm->r_start, flags, error, rack_to_usec_ts(tv),
15405 			rsm, RACK_SENT_FP, rsm->m, rsm->soff);
15406 	if (doing_tlp && (rack->fast_rsm_hack == 0)) {
15407 		rack->rc_tlp_in_progress = 1;
15408 		rack->r_ctl.rc_tlp_cnt_out++;
15409 	}
15410 	if (error == 0)
15411 		tcp_account_for_send(tp, len, 1, doing_tlp);
15412 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
15413 	rack->forced_ack = 0;	/* If we send something zap the FA flag */
15414 	if (IN_FASTRECOVERY(tp->t_flags) && rsm)
15415 		rack->r_ctl.retran_during_recovery += len;
15416 	{
15417 		int idx;
15418 
15419 		idx = (len / segsiz) + 3;
15420 		if (idx >= TCP_MSS_ACCT_ATIMER)
15421 			counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
15422 		else
15423 			counter_u64_add(rack_out_size[idx], 1);
15424 	}
15425 	if (tp->t_rtttime == 0) {
15426 		tp->t_rtttime = ticks;
15427 		tp->t_rtseq = startseq;
15428 		KMOD_TCPSTAT_INC(tcps_segstimed);
15429 	}
15430 	counter_u64_add(rack_fto_rsm_send, 1);
15431 	if (error && (error == ENOBUFS)) {
15432 		slot = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
15433 		if (rack->rc_enobuf < 0x7f)
15434 			rack->rc_enobuf++;
15435 		if (slot < (10 * HPTS_USEC_IN_MSEC))
15436 			slot = 10 * HPTS_USEC_IN_MSEC;
15437 	} else
15438 		slot = rack_get_pacing_delay(rack, tp, len, NULL, segsiz);
15439 	if ((slot == 0) ||
15440 	    (rack->rc_always_pace == 0) ||
15441 	    (rack->r_rr_config == 1)) {
15442 		/*
15443 		 * We have no pacing set or we
15444 		 * are using old-style rack or
15445 		 * we are overriden to use the old 1ms pacing.
15446 		 */
15447 		slot = rack->r_ctl.rc_min_to;
15448 	}
15449 	rack_start_hpts_timer(rack, tp, cts, slot, len, 0);
15450 	if (rack->r_must_retran) {
15451 		rack->r_ctl.rc_out_at_rto -= (rsm->r_end - rsm->r_start);
15452 		if (SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) {
15453 			/*
15454 			 * We have retransmitted all we need.
15455 			 */
15456 			rack->r_must_retran = 0;
15457 			rack->r_ctl.rc_out_at_rto = 0;
15458 		}
15459 	}
15460 #ifdef TCP_ACCOUNTING
15461 	crtsc = get_cyclecount();
15462 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
15463 		tp->tcp_cnt_counters[SND_OUT_DATA] += cnt_thru;
15464 	}
15465 	counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], cnt_thru);
15466 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
15467 		tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
15468 	}
15469 	counter_u64_add(tcp_proc_time[SND_OUT_DATA], (crtsc - ts_val));
15470 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
15471 		tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((len + segsiz - 1) / segsiz);
15472 	}
15473 	counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((len + segsiz - 1) / segsiz));
15474 	sched_unpin();
15475 #endif
15476 	return (0);
15477 failed:
15478 	if (m)
15479 		m_free(m);
15480 	return (-1);
15481 }
15482 
15483 static void
15484 rack_sndbuf_autoscale(struct tcp_rack *rack)
15485 {
15486 	/*
15487 	 * Automatic sizing of send socket buffer.  Often the send buffer
15488 	 * size is not optimally adjusted to the actual network conditions
15489 	 * at hand (delay bandwidth product).  Setting the buffer size too
15490 	 * small limits throughput on links with high bandwidth and high
15491 	 * delay (eg. trans-continental/oceanic links).  Setting the
15492 	 * buffer size too big consumes too much real kernel memory,
15493 	 * especially with many connections on busy servers.
15494 	 *
15495 	 * The criteria to step up the send buffer one notch are:
15496 	 *  1. receive window of remote host is larger than send buffer
15497 	 *     (with a fudge factor of 5/4th);
15498 	 *  2. send buffer is filled to 7/8th with data (so we actually
15499 	 *     have data to make use of it);
15500 	 *  3. send buffer fill has not hit maximal automatic size;
15501 	 *  4. our send window (slow start and cogestion controlled) is
15502 	 *     larger than sent but unacknowledged data in send buffer.
15503 	 *
15504 	 * Note that the rack version moves things much faster since
15505 	 * we want to avoid hitting cache lines in the rack_fast_output()
15506 	 * path so this is called much less often and thus moves
15507 	 * the SB forward by a percentage.
15508 	 */
15509 	struct socket *so;
15510 	struct tcpcb *tp;
15511 	uint32_t sendwin, scaleup;
15512 
15513 	tp = rack->rc_tp;
15514 	so = rack->rc_inp->inp_socket;
15515 	sendwin = min(rack->r_ctl.cwnd_to_use, tp->snd_wnd);
15516 	if (V_tcp_do_autosndbuf && so->so_snd.sb_flags & SB_AUTOSIZE) {
15517 		if ((tp->snd_wnd / 4 * 5) >= so->so_snd.sb_hiwat &&
15518 		    sbused(&so->so_snd) >=
15519 		    (so->so_snd.sb_hiwat / 8 * 7) &&
15520 		    sbused(&so->so_snd) < V_tcp_autosndbuf_max &&
15521 		    sendwin >= (sbused(&so->so_snd) -
15522 		    (tp->snd_nxt - tp->snd_una))) {
15523 			if (rack_autosndbuf_inc)
15524 				scaleup = (rack_autosndbuf_inc * so->so_snd.sb_hiwat) / 100;
15525 			else
15526 				scaleup = V_tcp_autosndbuf_inc;
15527 			if (scaleup < V_tcp_autosndbuf_inc)
15528 				scaleup = V_tcp_autosndbuf_inc;
15529 			scaleup += so->so_snd.sb_hiwat;
15530 			if (scaleup > V_tcp_autosndbuf_max)
15531 				scaleup = V_tcp_autosndbuf_max;
15532 			if (!sbreserve_locked(&so->so_snd, scaleup, so, curthread))
15533 				so->so_snd.sb_flags &= ~SB_AUTOSIZE;
15534 		}
15535 	}
15536 }
15537 
15538 static int
15539 rack_fast_output(struct tcpcb *tp, struct tcp_rack *rack, uint64_t ts_val,
15540 		 uint32_t cts, uint32_t ms_cts, struct timeval *tv, long tot_len, int *send_err)
15541 {
15542 	/*
15543 	 * Enter to do fast output. We are given that the sched_pin is
15544 	 * in place (if accounting is compiled in) and the cycle count taken
15545 	 * at entry is in place in ts_val. The idea here is that
15546 	 * we know how many more bytes needs to be sent (presumably either
15547 	 * during pacing or to fill the cwnd and that was greater than
15548 	 * the max-burst). We have how much to send and all the info we
15549 	 * need to just send.
15550 	 */
15551 	struct ip *ip = NULL;
15552 	struct udphdr *udp = NULL;
15553 	struct tcphdr *th = NULL;
15554 	struct mbuf *m, *s_mb;
15555 	struct inpcb *inp;
15556 	uint8_t *cpto;
15557 	struct tcp_log_buffer *lgb;
15558 #ifdef TCP_ACCOUNTING
15559 	uint64_t crtsc;
15560 #endif
15561 	struct tcpopt to;
15562 	u_char opt[TCP_MAXOLEN];
15563 	uint32_t hdrlen, optlen;
15564 	int cnt_thru = 1;
15565 	int32_t slot, segsiz, len, max_val, tso = 0, sb_offset, error, flags, ulen = 0;
15566 	uint32_t us_cts, s_soff;
15567 	uint32_t if_hw_tsomaxsegcount = 0, startseq;
15568 	uint32_t if_hw_tsomaxsegsize;
15569 	uint16_t add_flag = RACK_SENT_FP;
15570 #ifdef INET6
15571 	struct ip6_hdr *ip6 = NULL;
15572 
15573 	if (rack->r_is_v6) {
15574 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
15575 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
15576 	} else
15577 #endif				/* INET6 */
15578 	{
15579 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
15580 		hdrlen = sizeof(struct tcpiphdr);
15581 	}
15582 	if (tp->t_port && (V_tcp_udp_tunneling_port == 0)) {
15583 		m = NULL;
15584 		goto failed;
15585 	}
15586 	startseq = tp->snd_max;
15587 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
15588 	inp = rack->rc_inp;
15589 	len = rack->r_ctl.fsb.left_to_send;
15590 	to.to_flags = 0;
15591 	flags = rack->r_ctl.fsb.tcp_flags;
15592 	if (tp->t_flags & TF_RCVD_TSTMP) {
15593 		to.to_tsval = ms_cts + tp->ts_offset;
15594 		to.to_tsecr = tp->ts_recent;
15595 		to.to_flags = TOF_TS;
15596 	}
15597 	optlen = tcp_addoptions(&to, opt);
15598 	hdrlen += optlen;
15599 	udp = rack->r_ctl.fsb.udp;
15600 	if (udp)
15601 		hdrlen += sizeof(struct udphdr);
15602 	if (rack->r_ctl.rc_pace_max_segs)
15603 		max_val = rack->r_ctl.rc_pace_max_segs;
15604 	else if (rack->rc_user_set_max_segs)
15605 		max_val = rack->rc_user_set_max_segs * segsiz;
15606 	else
15607 		max_val = len;
15608 	if ((tp->t_flags & TF_TSO) &&
15609 	    V_tcp_do_tso &&
15610 	    (len > segsiz) &&
15611 	    (tp->t_port == 0))
15612 		tso = 1;
15613 again:
15614 #ifdef INET6
15615 	if (MHLEN < hdrlen + max_linkhdr)
15616 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
15617 	else
15618 #endif
15619 		m = m_gethdr(M_NOWAIT, MT_DATA);
15620 	if (m == NULL)
15621 		goto failed;
15622 	m->m_data += max_linkhdr;
15623 	m->m_len = hdrlen;
15624 	th = rack->r_ctl.fsb.th;
15625 	/* Establish the len to send */
15626 	if (len > max_val)
15627 		len = max_val;
15628 	if ((tso) && (len + optlen > tp->t_maxseg)) {
15629 		uint32_t if_hw_tsomax;
15630 		int32_t max_len;
15631 
15632 		/* extract TSO information */
15633 		if_hw_tsomax = tp->t_tsomax;
15634 		if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
15635 		if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
15636 		/*
15637 		 * Check if we should limit by maximum payload
15638 		 * length:
15639 		 */
15640 		if (if_hw_tsomax != 0) {
15641 			/* compute maximum TSO length */
15642 			max_len = (if_hw_tsomax - hdrlen -
15643 				   max_linkhdr);
15644 			if (max_len <= 0) {
15645 				goto failed;
15646 			} else if (len > max_len) {
15647 				len = max_len;
15648 			}
15649 		}
15650 		if (len <= segsiz) {
15651 			/*
15652 			 * In case there are too many small fragments don't
15653 			 * use TSO:
15654 			 */
15655 			tso = 0;
15656 		}
15657 	} else {
15658 		tso = 0;
15659 	}
15660 	if ((tso == 0) && (len > segsiz))
15661 		len = segsiz;
15662 	us_cts = tcp_get_usecs(tv);
15663 	if ((len == 0) ||
15664 	    (len <= MHLEN - hdrlen - max_linkhdr)) {
15665 		goto failed;
15666 	}
15667 	sb_offset = tp->snd_max - tp->snd_una;
15668 	th->th_seq = htonl(tp->snd_max);
15669 	th->th_ack = htonl(tp->rcv_nxt);
15670 	th->th_flags = flags;
15671 	th->th_win = htons((u_short)(rack->r_ctl.fsb.recwin >> tp->rcv_scale));
15672 	if (th->th_win == 0) {
15673 		tp->t_sndzerowin++;
15674 		tp->t_flags |= TF_RXWIN0SENT;
15675 	} else
15676 		tp->t_flags &= ~TF_RXWIN0SENT;
15677 	tp->snd_up = tp->snd_una;	/* drag it along, its deprecated */
15678 	KMOD_TCPSTAT_INC(tcps_sndpack);
15679 	KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
15680 #ifdef STATS
15681 	stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
15682 				 len);
15683 #endif
15684 	if (rack->r_ctl.fsb.m == NULL)
15685 		goto failed;
15686 
15687 	/* s_mb and s_soff are saved for rack_log_output */
15688 	m->m_next = rack_fo_m_copym(rack, &len, if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, &s_mb, &s_soff);
15689 	if (len <= segsiz) {
15690 		/*
15691 		 * Must have ran out of mbufs for the copy
15692 		 * shorten it to no longer need tso. Lets
15693 		 * not put on sendalot since we are low on
15694 		 * mbufs.
15695 		 */
15696 		tso = 0;
15697 	}
15698 	if (rack->r_ctl.fsb.rfo_apply_push &&
15699 	    (len == rack->r_ctl.fsb.left_to_send)) {
15700 		th->th_flags |= TH_PUSH;
15701 		add_flag |= RACK_HAD_PUSH;
15702 	}
15703 	if ((m->m_next == NULL) || (len <= 0)){
15704 		goto failed;
15705 	}
15706 	if (udp) {
15707 		if (rack->r_is_v6)
15708 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
15709 		else
15710 			ulen = hdrlen + len - sizeof(struct ip);
15711 		udp->uh_ulen = htons(ulen);
15712 	}
15713 	m->m_pkthdr.rcvif = (struct ifnet *)0;
15714 	if (tp->t_state == TCPS_ESTABLISHED &&
15715 	    (tp->t_flags2 & TF2_ECN_PERMIT)) {
15716 		/*
15717 		 * If the peer has ECN, mark data packets with ECN capable
15718 		 * transmission (ECT). Ignore pure ack packets,
15719 		 * retransmissions.
15720 		 */
15721 		if (len > 0 && SEQ_GEQ(tp->snd_nxt, tp->snd_max)) {
15722 #ifdef INET6
15723 			if (rack->r_is_v6)
15724 				ip6->ip6_flow |= htonl(IPTOS_ECN_ECT0 << 20);
15725 			else
15726 #endif
15727 				ip->ip_tos |= IPTOS_ECN_ECT0;
15728 			KMOD_TCPSTAT_INC(tcps_ecn_ect0);
15729 			/*
15730 			 * Reply with proper ECN notifications.
15731 			 * Only set CWR on new data segments.
15732 			 */
15733 			if (tp->t_flags2 & TF2_ECN_SND_CWR) {
15734 				flags |= TH_CWR;
15735 				tp->t_flags2 &= ~TF2_ECN_SND_CWR;
15736 			}
15737 		}
15738 		if (tp->t_flags2 & TF2_ECN_SND_ECE)
15739 			flags |= TH_ECE;
15740 	}
15741 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
15742 #ifdef INET6
15743 	if (rack->r_is_v6) {
15744 		if (tp->t_port) {
15745 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
15746 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
15747 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
15748 			th->th_sum = htons(0);
15749 			UDPSTAT_INC(udps_opackets);
15750 		} else {
15751 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
15752 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
15753 			th->th_sum = in6_cksum_pseudo(ip6,
15754 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
15755 						      0);
15756 		}
15757 	}
15758 #endif
15759 #if defined(INET6) && defined(INET)
15760 	else
15761 #endif
15762 #ifdef INET
15763 	{
15764 		if (tp->t_port) {
15765 			m->m_pkthdr.csum_flags = CSUM_UDP;
15766 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
15767 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
15768 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
15769 			th->th_sum = htons(0);
15770 			UDPSTAT_INC(udps_opackets);
15771 		} else {
15772 			m->m_pkthdr.csum_flags = CSUM_TCP;
15773 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
15774 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
15775 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
15776 									IPPROTO_TCP + len + optlen));
15777 		}
15778 		/* IP version must be set here for ipv4/ipv6 checking later */
15779 		KASSERT(ip->ip_v == IPVERSION,
15780 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
15781 	}
15782 #endif
15783 	if (tso) {
15784 		KASSERT(len > tp->t_maxseg - optlen,
15785 			("%s: len <= tso_segsz tp:%p", __func__, tp));
15786 		m->m_pkthdr.csum_flags |= CSUM_TSO;
15787 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
15788 	}
15789 #ifdef INET6
15790 	if (rack->r_is_v6) {
15791 		ip6->ip6_hlim = rack->r_ctl.fsb.hoplimit;
15792 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
15793 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
15794 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
15795 		else
15796 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
15797 	}
15798 #endif
15799 #if defined(INET) && defined(INET6)
15800 	else
15801 #endif
15802 #ifdef INET
15803 	{
15804 		ip->ip_len = htons(m->m_pkthdr.len);
15805 		ip->ip_ttl = rack->r_ctl.fsb.hoplimit;
15806 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
15807 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
15808 			if (tp->t_port == 0 || len < V_tcp_minmss) {
15809 				ip->ip_off |= htons(IP_DF);
15810 			}
15811 		} else {
15812 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
15813 		}
15814 	}
15815 #endif
15816 	/* Time to copy in our header */
15817 	cpto = mtod(m, uint8_t *);
15818 	memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
15819 	th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
15820 	if (optlen) {
15821 		bcopy(opt, th + 1, optlen);
15822 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
15823 	} else {
15824 		th->th_off = sizeof(struct tcphdr) >> 2;
15825 	}
15826 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
15827 		union tcp_log_stackspecific log;
15828 
15829 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
15830 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
15831 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
15832 		if (rack->rack_no_prr)
15833 			log.u_bbr.flex1 = 0;
15834 		else
15835 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
15836 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
15837 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
15838 		log.u_bbr.flex4 = max_val;
15839 		log.u_bbr.flex5 = 0;
15840 		/* Save off the early/late values */
15841 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
15842 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
15843 		log.u_bbr.bw_inuse = rack_get_bw(rack);
15844 		log.u_bbr.flex8 = 0;
15845 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
15846 		log.u_bbr.flex7 = 44;
15847 		log.u_bbr.pkts_out = tp->t_maxseg;
15848 		log.u_bbr.timeStamp = cts;
15849 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
15850 		log.u_bbr.lt_epoch = rack->r_ctl.cwnd_to_use;
15851 		log.u_bbr.delivered = 0;
15852 		lgb = tcp_log_event_(tp, th, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
15853 				     len, &log, false, NULL, NULL, 0, tv);
15854 	} else
15855 		lgb = NULL;
15856 #ifdef INET6
15857 	if (rack->r_is_v6) {
15858 		error = ip6_output(m, NULL,
15859 				   &inp->inp_route6,
15860 				   0, NULL, NULL, inp);
15861 	}
15862 #endif
15863 #if defined(INET) && defined(INET6)
15864 	else
15865 #endif
15866 #ifdef INET
15867 	{
15868 		error = ip_output(m, NULL,
15869 				  &inp->inp_route,
15870 				  0, 0, inp);
15871 	}
15872 #endif
15873 	if (lgb) {
15874 		lgb->tlb_errno = error;
15875 		lgb = NULL;
15876 	}
15877 	if (error) {
15878 		*send_err = error;
15879 		m = NULL;
15880 		goto failed;
15881 	}
15882 	rack_log_output(tp, &to, len, tp->snd_max, flags, error, rack_to_usec_ts(tv),
15883 			NULL, add_flag, s_mb, s_soff);
15884 	m = NULL;
15885 	if (tp->snd_una == tp->snd_max) {
15886 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
15887 		rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
15888 		tp->t_acktime = ticks;
15889 	}
15890 	if (error == 0)
15891 		tcp_account_for_send(tp, len, 0, 0);
15892 
15893 	rack->forced_ack = 0;	/* If we send something zap the FA flag */
15894 	tot_len += len;
15895 	if ((tp->t_flags & TF_GPUTINPROG) == 0)
15896 		rack_start_gp_measurement(tp, rack, tp->snd_max, sb_offset);
15897 	tp->snd_max += len;
15898 	tp->snd_nxt = tp->snd_max;
15899 	{
15900 		int idx;
15901 
15902 		idx = (len / segsiz) + 3;
15903 		if (idx >= TCP_MSS_ACCT_ATIMER)
15904 			counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
15905 		else
15906 			counter_u64_add(rack_out_size[idx], 1);
15907 	}
15908 	if (len <= rack->r_ctl.fsb.left_to_send)
15909 		rack->r_ctl.fsb.left_to_send -= len;
15910 	else
15911 		rack->r_ctl.fsb.left_to_send = 0;
15912 	if (rack->r_ctl.fsb.left_to_send < segsiz) {
15913 		rack->r_fast_output = 0;
15914 		rack->r_ctl.fsb.left_to_send = 0;
15915 		/* At the end of fast_output scale up the sb */
15916 		SOCKBUF_LOCK(&rack->rc_inp->inp_socket->so_snd);
15917 		rack_sndbuf_autoscale(rack);
15918 		SOCKBUF_UNLOCK(&rack->rc_inp->inp_socket->so_snd);
15919 	}
15920 	if (tp->t_rtttime == 0) {
15921 		tp->t_rtttime = ticks;
15922 		tp->t_rtseq = startseq;
15923 		KMOD_TCPSTAT_INC(tcps_segstimed);
15924 	}
15925 	if ((rack->r_ctl.fsb.left_to_send >= segsiz) &&
15926 	    (max_val > len) &&
15927 	    (tso == 0)) {
15928 		max_val -= len;
15929 		len = segsiz;
15930 		th = rack->r_ctl.fsb.th;
15931 		cnt_thru++;
15932 		goto again;
15933 	}
15934 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
15935 	counter_u64_add(rack_fto_send, 1);
15936 	slot = rack_get_pacing_delay(rack, tp, tot_len, NULL, segsiz);
15937 	rack_start_hpts_timer(rack, tp, cts, slot, tot_len, 0);
15938 #ifdef TCP_ACCOUNTING
15939 	crtsc = get_cyclecount();
15940 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
15941 		tp->tcp_cnt_counters[SND_OUT_DATA] += cnt_thru;
15942 	}
15943 	counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], cnt_thru);
15944 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
15945 		tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
15946 	}
15947 	counter_u64_add(tcp_proc_time[SND_OUT_DATA], (crtsc - ts_val));
15948 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
15949 		tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len + segsiz - 1) / segsiz);
15950 	}
15951 	counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((tot_len + segsiz - 1) / segsiz));
15952 	sched_unpin();
15953 #endif
15954 	return (0);
15955 failed:
15956 	if (m)
15957 		m_free(m);
15958 	rack->r_fast_output = 0;
15959 	return (-1);
15960 }
15961 
15962 static int
15963 rack_output(struct tcpcb *tp)
15964 {
15965 	struct socket *so;
15966 	uint32_t recwin;
15967 	uint32_t sb_offset, s_moff = 0;
15968 	int32_t len, flags, error = 0;
15969 	struct mbuf *m, *s_mb = NULL;
15970 	struct mbuf *mb;
15971 	uint32_t if_hw_tsomaxsegcount = 0;
15972 	uint32_t if_hw_tsomaxsegsize;
15973 	int32_t segsiz, minseg;
15974 	long tot_len_this_send = 0;
15975 #ifdef INET
15976 	struct ip *ip = NULL;
15977 #endif
15978 #ifdef TCPDEBUG
15979 	struct ipovly *ipov = NULL;
15980 #endif
15981 	struct udphdr *udp = NULL;
15982 	struct tcp_rack *rack;
15983 	struct tcphdr *th;
15984 	uint8_t pass = 0;
15985 	uint8_t mark = 0;
15986 	uint8_t wanted_cookie = 0;
15987 	u_char opt[TCP_MAXOLEN];
15988 	unsigned ipoptlen, optlen, hdrlen, ulen=0;
15989 	uint32_t rack_seq;
15990 
15991 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
15992 	unsigned ipsec_optlen = 0;
15993 
15994 #endif
15995 	int32_t idle, sendalot;
15996 	int32_t sub_from_prr = 0;
15997 	volatile int32_t sack_rxmit;
15998 	struct rack_sendmap *rsm = NULL;
15999 	int32_t tso, mtu;
16000 	struct tcpopt to;
16001 	int32_t slot = 0;
16002 	int32_t sup_rack = 0;
16003 	uint32_t cts, ms_cts, delayed, early;
16004 	uint16_t add_flag = RACK_SENT_SP;
16005 	uint8_t hpts_calling,  doing_tlp = 0;
16006 	uint32_t cwnd_to_use, pace_max_seg;
16007 	int32_t do_a_prefetch = 0;
16008 	int32_t prefetch_rsm = 0;
16009 	int32_t orig_len = 0;
16010 	struct timeval tv;
16011 	int32_t prefetch_so_done = 0;
16012 	struct tcp_log_buffer *lgb;
16013 	struct inpcb *inp;
16014 	struct sockbuf *sb;
16015 	uint64_t ts_val = 0;
16016 #ifdef TCP_ACCOUNTING
16017 	uint64_t crtsc;
16018 #endif
16019 #ifdef INET6
16020 	struct ip6_hdr *ip6 = NULL;
16021 	int32_t isipv6;
16022 #endif
16023 	uint8_t filled_all = 0;
16024 	bool hw_tls = false;
16025 
16026 	/* setup and take the cache hits here */
16027 	rack = (struct tcp_rack *)tp->t_fb_ptr;
16028 #ifdef TCP_ACCOUNTING
16029 	sched_pin();
16030 	ts_val = get_cyclecount();
16031 #endif
16032 	hpts_calling = rack->rc_inp->inp_hpts_calls;
16033 	NET_EPOCH_ASSERT();
16034 	INP_WLOCK_ASSERT(rack->rc_inp);
16035 #ifdef TCP_OFFLOAD
16036 	if (tp->t_flags & TF_TOE) {
16037 #ifdef TCP_ACCOUNTING
16038 		sched_unpin();
16039 #endif
16040 		return (tcp_offload_output(tp));
16041 	}
16042 #endif
16043 	/*
16044 	 * For TFO connections in SYN_RECEIVED, only allow the initial
16045 	 * SYN|ACK and those sent by the retransmit timer.
16046 	 */
16047 	if (IS_FASTOPEN(tp->t_flags) &&
16048 	    (tp->t_state == TCPS_SYN_RECEIVED) &&
16049 	    SEQ_GT(tp->snd_max, tp->snd_una) &&    /* initial SYN|ACK sent */
16050 	    (rack->r_ctl.rc_resend == NULL)) {         /* not a retransmit */
16051 #ifdef TCP_ACCOUNTING
16052 		sched_unpin();
16053 #endif
16054 		return (0);
16055 	}
16056 #ifdef INET6
16057 	if (rack->r_state) {
16058 		/* Use the cache line loaded if possible */
16059 		isipv6 = rack->r_is_v6;
16060 	} else {
16061 		isipv6 = (rack->rc_inp->inp_vflag & INP_IPV6) != 0;
16062 	}
16063 #endif
16064 	early = 0;
16065 	cts = tcp_get_usecs(&tv);
16066 	ms_cts = tcp_tv_to_mssectick(&tv);
16067 	if (((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) &&
16068 	    rack->rc_inp->inp_in_hpts) {
16069 		/*
16070 		 * We are on the hpts for some timer but not hptsi output.
16071 		 * Remove from the hpts unconditionally.
16072 		 */
16073 		rack_timer_cancel(tp, rack, cts, __LINE__);
16074 	}
16075 	/* Are we pacing and late? */
16076 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
16077 	    TSTMP_GEQ(cts, rack->r_ctl.rc_last_output_to)) {
16078 		/* We are delayed */
16079 		delayed = cts - rack->r_ctl.rc_last_output_to;
16080 	} else {
16081 		delayed = 0;
16082 	}
16083 	/* Do the timers, which may override the pacer */
16084 	if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
16085 		if (rack_process_timers(tp, rack, cts, hpts_calling)) {
16086 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_ATIMER], 1);
16087 #ifdef TCP_ACCOUNTING
16088 			sched_unpin();
16089 #endif
16090 			return (0);
16091 		}
16092 	}
16093 	if (rack->rc_in_persist) {
16094 		if (rack->rc_inp->inp_in_hpts == 0) {
16095 			/* Timer is not running */
16096 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
16097 		}
16098 #ifdef TCP_ACCOUNTING
16099 		sched_unpin();
16100 #endif
16101 		return (0);
16102 	}
16103 	if ((rack->r_timer_override) ||
16104 	    (rack->rc_ack_can_sendout_data) ||
16105 	    (delayed) ||
16106 	    (tp->t_state < TCPS_ESTABLISHED)) {
16107 		rack->rc_ack_can_sendout_data = 0;
16108 		if (rack->rc_inp->inp_in_hpts)
16109 			tcp_hpts_remove(rack->rc_inp, HPTS_REMOVE_OUTPUT);
16110 	} else if (rack->rc_inp->inp_in_hpts) {
16111 		/*
16112 		 * On the hpts you can't pass even if ACKNOW is on, we will
16113 		 * when the hpts fires.
16114 		 */
16115 #ifdef TCP_ACCOUNTING
16116 		crtsc = get_cyclecount();
16117 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16118 			tp->tcp_proc_time[SND_BLOCKED] += (crtsc - ts_val);
16119 		}
16120 		counter_u64_add(tcp_proc_time[SND_BLOCKED], (crtsc - ts_val));
16121 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16122 			tp->tcp_cnt_counters[SND_BLOCKED]++;
16123 		}
16124 		counter_u64_add(tcp_cnt_counters[SND_BLOCKED], 1);
16125 		sched_unpin();
16126 #endif
16127 		counter_u64_add(rack_out_size[TCP_MSS_ACCT_INPACE], 1);
16128 		return (0);
16129 	}
16130 	rack->rc_inp->inp_hpts_calls = 0;
16131 	/* Finish out both pacing early and late accounting */
16132 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
16133 	    TSTMP_GT(rack->r_ctl.rc_last_output_to, cts)) {
16134 		early = rack->r_ctl.rc_last_output_to - cts;
16135 	} else
16136 		early = 0;
16137 	if (delayed) {
16138 		rack->r_ctl.rc_agg_delayed += delayed;
16139 		rack->r_late = 1;
16140 	} else if (early) {
16141 		rack->r_ctl.rc_agg_early += early;
16142 		rack->r_early = 1;
16143 	}
16144 	/* Now that early/late accounting is done turn off the flag */
16145 	rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
16146 	rack->r_wanted_output = 0;
16147 	rack->r_timer_override = 0;
16148 	if ((tp->t_state != rack->r_state) &&
16149 	    TCPS_HAVEESTABLISHED(tp->t_state)) {
16150 		rack_set_state(tp, rack);
16151 	}
16152 	if ((rack->r_fast_output) &&
16153 	    (tp->rcv_numsacks == 0)) {
16154 		int ret;
16155 
16156 		error = 0;
16157 		ret = rack_fast_output(tp, rack, ts_val, cts, ms_cts, &tv, tot_len_this_send, &error);
16158 		if (ret >= 0)
16159 			return(ret);
16160 		else if (error) {
16161 			inp = rack->rc_inp;
16162 			so = inp->inp_socket;
16163 			sb = &so->so_snd;
16164 			goto nomore;
16165 		}
16166 	}
16167 	inp = rack->rc_inp;
16168 	/*
16169 	 * For TFO connections in SYN_SENT or SYN_RECEIVED,
16170 	 * only allow the initial SYN or SYN|ACK and those sent
16171 	 * by the retransmit timer.
16172 	 */
16173 	if (IS_FASTOPEN(tp->t_flags) &&
16174 	    ((tp->t_state == TCPS_SYN_RECEIVED) ||
16175 	     (tp->t_state == TCPS_SYN_SENT)) &&
16176 	    SEQ_GT(tp->snd_max, tp->snd_una) && /* initial SYN or SYN|ACK sent */
16177 	    (tp->t_rxtshift == 0)) {              /* not a retransmit */
16178 		cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
16179 		so = inp->inp_socket;
16180 		sb = &so->so_snd;
16181 		goto just_return_nolock;
16182 	}
16183 	/*
16184 	 * Determine length of data that should be transmitted, and flags
16185 	 * that will be used. If there is some data or critical controls
16186 	 * (SYN, RST) to send, then transmit; otherwise, investigate
16187 	 * further.
16188 	 */
16189 	idle = (tp->t_flags & TF_LASTIDLE) || (tp->snd_max == tp->snd_una);
16190 	if (tp->t_idle_reduce) {
16191 		if (idle && ((ticks - tp->t_rcvtime) >= tp->t_rxtcur))
16192 			rack_cc_after_idle(rack, tp);
16193 	}
16194 	tp->t_flags &= ~TF_LASTIDLE;
16195 	if (idle) {
16196 		if (tp->t_flags & TF_MORETOCOME) {
16197 			tp->t_flags |= TF_LASTIDLE;
16198 			idle = 0;
16199 		}
16200 	}
16201 	if ((tp->snd_una == tp->snd_max) &&
16202 	    rack->r_ctl.rc_went_idle_time &&
16203 	    TSTMP_GT(cts, rack->r_ctl.rc_went_idle_time)) {
16204 		idle = cts - rack->r_ctl.rc_went_idle_time;
16205 		if (idle > rack_min_probertt_hold) {
16206 			/* Count as a probe rtt */
16207 			if (rack->in_probe_rtt == 0) {
16208 				rack->r_ctl.rc_lower_rtt_us_cts = cts;
16209 				rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
16210 				rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
16211 				rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
16212 			} else {
16213 				rack_exit_probertt(rack, cts);
16214 			}
16215 		}
16216 		idle = 0;
16217 	}
16218 	if (rack_use_fsb && (rack->r_fsb_inited == 0))
16219 		rack_init_fsb_block(tp, rack);
16220 again:
16221 	/*
16222 	 * If we've recently taken a timeout, snd_max will be greater than
16223 	 * snd_nxt.  There may be SACK information that allows us to avoid
16224 	 * resending already delivered data.  Adjust snd_nxt accordingly.
16225 	 */
16226 	sendalot = 0;
16227 	cts = tcp_get_usecs(&tv);
16228 	ms_cts = tcp_tv_to_mssectick(&tv);
16229 	tso = 0;
16230 	mtu = 0;
16231 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
16232 	minseg = segsiz;
16233 	if (rack->r_ctl.rc_pace_max_segs == 0)
16234 		pace_max_seg = rack->rc_user_set_max_segs * segsiz;
16235 	else
16236 		pace_max_seg = rack->r_ctl.rc_pace_max_segs;
16237 	sb_offset = tp->snd_max - tp->snd_una;
16238 	cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
16239 	flags = tcp_outflags[tp->t_state];
16240 	while (rack->rc_free_cnt < rack_free_cache) {
16241 		rsm = rack_alloc(rack);
16242 		if (rsm == NULL) {
16243 			if (inp->inp_hpts_calls)
16244 				/* Retry in a ms */
16245 				slot = (1 * HPTS_USEC_IN_MSEC);
16246 			so = inp->inp_socket;
16247 			sb = &so->so_snd;
16248 			goto just_return_nolock;
16249 		}
16250 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_free, rsm, r_tnext);
16251 		rack->rc_free_cnt++;
16252 		rsm = NULL;
16253 	}
16254 	if (inp->inp_hpts_calls)
16255 		inp->inp_hpts_calls = 0;
16256 	sack_rxmit = 0;
16257 	len = 0;
16258 	rsm = NULL;
16259 	if (flags & TH_RST) {
16260 		SOCKBUF_LOCK(&inp->inp_socket->so_snd);
16261 		so = inp->inp_socket;
16262 		sb = &so->so_snd;
16263 		goto send;
16264 	}
16265 	if (rack->r_ctl.rc_resend) {
16266 		/* Retransmit timer */
16267 		rsm = rack->r_ctl.rc_resend;
16268 		rack->r_ctl.rc_resend = NULL;
16269 		rsm->r_flags &= ~RACK_TLP;
16270 		len = rsm->r_end - rsm->r_start;
16271 		sack_rxmit = 1;
16272 		sendalot = 0;
16273 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
16274 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
16275 			 __func__, __LINE__,
16276 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
16277 		sb_offset = rsm->r_start - tp->snd_una;
16278 		if (len >= segsiz)
16279 			len = segsiz;
16280 	} else if ((rsm = tcp_rack_output(tp, rack, cts)) != NULL) {
16281 		/* We have a retransmit that takes precedence */
16282 		rsm->r_flags &= ~RACK_TLP;
16283 		if ((!IN_FASTRECOVERY(tp->t_flags)) &&
16284 		    ((tp->t_flags & TF_WASFRECOVERY) == 0)) {
16285 			/* Enter recovery if not induced by a time-out */
16286 			rack->r_ctl.rc_rsm_start = rsm->r_start;
16287 			rack->r_ctl.rc_cwnd_at = tp->snd_cwnd;
16288 			rack->r_ctl.rc_ssthresh_at = tp->snd_ssthresh;
16289 			rack_cong_signal(tp, CC_NDUPACK, tp->snd_una);
16290 		}
16291 #ifdef INVARIANTS
16292 		if (SEQ_LT(rsm->r_start, tp->snd_una)) {
16293 			panic("Huh, tp:%p rack:%p rsm:%p start:%u < snd_una:%u\n",
16294 			      tp, rack, rsm, rsm->r_start, tp->snd_una);
16295 		}
16296 #endif
16297 		len = rsm->r_end - rsm->r_start;
16298 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
16299 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
16300 			 __func__, __LINE__,
16301 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
16302 		sb_offset = rsm->r_start - tp->snd_una;
16303 		sendalot = 0;
16304 		if (len >= segsiz)
16305 			len = segsiz;
16306 		if (len > 0) {
16307 			sack_rxmit = 1;
16308 			KMOD_TCPSTAT_INC(tcps_sack_rexmits);
16309 			KMOD_TCPSTAT_ADD(tcps_sack_rexmit_bytes,
16310 			    min(len, segsiz));
16311 			counter_u64_add(rack_rtm_prr_retran, 1);
16312 		}
16313 	} else if (rack->r_ctl.rc_tlpsend) {
16314 		/* Tail loss probe */
16315 		long cwin;
16316 		long tlen;
16317 
16318 		doing_tlp = 1;
16319 		/*
16320 		 * Check if we can do a TLP with a RACK'd packet
16321 		 * this can happen if we are not doing the rack
16322 		 * cheat and we skipped to a TLP and it
16323 		 * went off.
16324 		 */
16325 		rsm = rack->r_ctl.rc_tlpsend;
16326 		rsm->r_flags |= RACK_TLP;
16327 
16328 		rack->r_ctl.rc_tlpsend = NULL;
16329 		sack_rxmit = 1;
16330 		tlen = rsm->r_end - rsm->r_start;
16331 		if (tlen > segsiz)
16332 			tlen = segsiz;
16333 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
16334 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
16335 			 __func__, __LINE__,
16336 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
16337 		sb_offset = rsm->r_start - tp->snd_una;
16338 		cwin = min(tp->snd_wnd, tlen);
16339 		len = cwin;
16340 	}
16341 	if (rack->r_must_retran &&
16342 	    (rsm == NULL)) {
16343 		/*
16344 		 * Non-Sack and we had a RTO or MTU change, we
16345 		 * need to retransmit until we reach
16346 		 * the former snd_max (rack->r_ctl.rc_snd_max_at_rto).
16347 		 */
16348 		if (SEQ_GT(tp->snd_max, tp->snd_una)) {
16349 			int sendwin, flight;
16350 
16351 			sendwin = min(tp->snd_wnd, tp->snd_cwnd);
16352 			flight = ctf_flight_size(tp, rack->r_ctl.rc_out_at_rto);
16353 			if (flight >= sendwin) {
16354 				so = inp->inp_socket;
16355 				sb = &so->so_snd;
16356 				goto just_return_nolock;
16357 			}
16358 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
16359 			KASSERT(rsm != NULL, ("rsm is NULL rack:%p r_must_retran set", rack));
16360 			if (rsm == NULL) {
16361 				/* TSNH */
16362 				rack->r_must_retran = 0;
16363 				rack->r_ctl.rc_out_at_rto = 0;
16364 				rack->r_must_retran = 0;
16365 				so = inp->inp_socket;
16366 				sb = &so->so_snd;
16367 				goto just_return_nolock;
16368 			}
16369 			sack_rxmit = 1;
16370 			len = rsm->r_end - rsm->r_start;
16371 			sendalot = 0;
16372 			sb_offset = rsm->r_start - tp->snd_una;
16373 			if (len >= segsiz)
16374 				len = segsiz;
16375 		} else {
16376 			/* We must be done if there is nothing outstanding */
16377 			rack->r_must_retran = 0;
16378 			rack->r_ctl.rc_out_at_rto = 0;
16379 		}
16380 	}
16381 	/*
16382 	 * Enforce a connection sendmap count limit if set
16383 	 * as long as we are not retransmiting.
16384 	 */
16385 	if ((rsm == NULL) &&
16386 	    (rack->do_detection == 0) &&
16387 	    (V_tcp_map_entries_limit > 0) &&
16388 	    (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
16389 		counter_u64_add(rack_to_alloc_limited, 1);
16390 		if (!rack->alloc_limit_reported) {
16391 			rack->alloc_limit_reported = 1;
16392 			counter_u64_add(rack_alloc_limited_conns, 1);
16393 		}
16394 		so = inp->inp_socket;
16395 		sb = &so->so_snd;
16396 		goto just_return_nolock;
16397 	}
16398 	if (rsm && (rsm->r_flags & RACK_HAS_FIN)) {
16399 		/* we are retransmitting the fin */
16400 		len--;
16401 		if (len) {
16402 			/*
16403 			 * When retransmitting data do *not* include the
16404 			 * FIN. This could happen from a TLP probe.
16405 			 */
16406 			flags &= ~TH_FIN;
16407 		}
16408 	}
16409 #ifdef INVARIANTS
16410 	/* For debugging */
16411 	rack->r_ctl.rc_rsm_at_retran = rsm;
16412 #endif
16413 	if (rsm && rack->r_fsb_inited && rack_use_rsm_rfo &&
16414 	    ((rsm->r_flags & RACK_HAS_FIN) == 0)) {
16415 		int ret;
16416 
16417 		ret = rack_fast_rsm_output(tp, rack, rsm, ts_val, cts, ms_cts, &tv, len);
16418 		if (ret == 0)
16419 			return (0);
16420 	}
16421 	so = inp->inp_socket;
16422 	sb = &so->so_snd;
16423 	if (do_a_prefetch == 0) {
16424 		kern_prefetch(sb, &do_a_prefetch);
16425 		do_a_prefetch = 1;
16426 	}
16427 #ifdef NETFLIX_SHARED_CWND
16428 	if ((tp->t_flags2 & TF2_TCP_SCWND_ALLOWED) &&
16429 	    rack->rack_enable_scwnd) {
16430 		/* We are doing cwnd sharing */
16431 		if (rack->gp_ready &&
16432 		    (rack->rack_attempted_scwnd == 0) &&
16433 		    (rack->r_ctl.rc_scw == NULL) &&
16434 		    tp->t_lib) {
16435 			/* The pcbid is in, lets make an attempt */
16436 			counter_u64_add(rack_try_scwnd, 1);
16437 			rack->rack_attempted_scwnd = 1;
16438 			rack->r_ctl.rc_scw = tcp_shared_cwnd_alloc(tp,
16439 								   &rack->r_ctl.rc_scw_index,
16440 								   segsiz);
16441 		}
16442 		if (rack->r_ctl.rc_scw &&
16443 		    (rack->rack_scwnd_is_idle == 1) &&
16444 		    sbavail(&so->so_snd)) {
16445 			/* we are no longer out of data */
16446 			tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
16447 			rack->rack_scwnd_is_idle = 0;
16448 		}
16449 		if (rack->r_ctl.rc_scw) {
16450 			/* First lets update and get the cwnd */
16451 			rack->r_ctl.cwnd_to_use = cwnd_to_use = tcp_shared_cwnd_update(rack->r_ctl.rc_scw,
16452 								    rack->r_ctl.rc_scw_index,
16453 								    tp->snd_cwnd, tp->snd_wnd, segsiz);
16454 		}
16455 	}
16456 #endif
16457 	/*
16458 	 * Get standard flags, and add SYN or FIN if requested by 'hidden'
16459 	 * state flags.
16460 	 */
16461 	if (tp->t_flags & TF_NEEDFIN)
16462 		flags |= TH_FIN;
16463 	if (tp->t_flags & TF_NEEDSYN)
16464 		flags |= TH_SYN;
16465 	if ((sack_rxmit == 0) && (prefetch_rsm == 0)) {
16466 		void *end_rsm;
16467 		end_rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
16468 		if (end_rsm)
16469 			kern_prefetch(end_rsm, &prefetch_rsm);
16470 		prefetch_rsm = 1;
16471 	}
16472 	SOCKBUF_LOCK(sb);
16473 	/*
16474 	 * If snd_nxt == snd_max and we have transmitted a FIN, the
16475 	 * sb_offset will be > 0 even if so_snd.sb_cc is 0, resulting in a
16476 	 * negative length.  This can also occur when TCP opens up its
16477 	 * congestion window while receiving additional duplicate acks after
16478 	 * fast-retransmit because TCP will reset snd_nxt to snd_max after
16479 	 * the fast-retransmit.
16480 	 *
16481 	 * In the normal retransmit-FIN-only case, however, snd_nxt will be
16482 	 * set to snd_una, the sb_offset will be 0, and the length may wind
16483 	 * up 0.
16484 	 *
16485 	 * If sack_rxmit is true we are retransmitting from the scoreboard
16486 	 * in which case len is already set.
16487 	 */
16488 	if ((sack_rxmit == 0) &&
16489 	    (TCPS_HAVEESTABLISHED(tp->t_state) || IS_FASTOPEN(tp->t_flags))) {
16490 		uint32_t avail;
16491 
16492 		avail = sbavail(sb);
16493 		if (SEQ_GT(tp->snd_nxt, tp->snd_una) && avail)
16494 			sb_offset = tp->snd_nxt - tp->snd_una;
16495 		else
16496 			sb_offset = 0;
16497 		if ((IN_FASTRECOVERY(tp->t_flags) == 0) || rack->rack_no_prr) {
16498 			if (rack->r_ctl.rc_tlp_new_data) {
16499 				/* TLP is forcing out new data */
16500 				if (rack->r_ctl.rc_tlp_new_data > (uint32_t) (avail - sb_offset)) {
16501 					rack->r_ctl.rc_tlp_new_data = (uint32_t) (avail - sb_offset);
16502 				}
16503 				if ((rack->r_ctl.rc_tlp_new_data + sb_offset) > tp->snd_wnd) {
16504 					if (tp->snd_wnd > sb_offset)
16505 						len = tp->snd_wnd - sb_offset;
16506 					else
16507 						len = 0;
16508 				} else {
16509 					len = rack->r_ctl.rc_tlp_new_data;
16510 				}
16511 				rack->r_ctl.rc_tlp_new_data = 0;
16512 				doing_tlp = 1;
16513 			}  else {
16514 				len = rack_what_can_we_send(tp, rack, cwnd_to_use, avail, sb_offset);
16515 			}
16516 			if ((rack->r_ctl.crte == NULL) && IN_FASTRECOVERY(tp->t_flags) && (len > segsiz)) {
16517 				/*
16518 				 * For prr=off, we need to send only 1 MSS
16519 				 * at a time. We do this because another sack could
16520 				 * be arriving that causes us to send retransmits and
16521 				 * we don't want to be on a long pace due to a larger send
16522 				 * that keeps us from sending out the retransmit.
16523 				 */
16524 				len = segsiz;
16525 			}
16526 		} else {
16527 			uint32_t outstanding;
16528 			/*
16529 			 * We are inside of a Fast recovery episode, this
16530 			 * is caused by a SACK or 3 dup acks. At this point
16531 			 * we have sent all the retransmissions and we rely
16532 			 * on PRR to dictate what we will send in the form of
16533 			 * new data.
16534 			 */
16535 
16536 			outstanding = tp->snd_max - tp->snd_una;
16537 			if ((rack->r_ctl.rc_prr_sndcnt + outstanding) > tp->snd_wnd) {
16538 				if (tp->snd_wnd > outstanding) {
16539 					len = tp->snd_wnd - outstanding;
16540 					/* Check to see if we have the data */
16541 					if ((sb_offset + len) > avail) {
16542 						/* It does not all fit */
16543 						if (avail > sb_offset)
16544 							len = avail - sb_offset;
16545 						else
16546 							len = 0;
16547 					}
16548 				} else {
16549 					len = 0;
16550 				}
16551 			} else if (avail > sb_offset) {
16552 				len = avail - sb_offset;
16553 			} else {
16554 				len = 0;
16555 			}
16556 			if (len > 0) {
16557 				if (len > rack->r_ctl.rc_prr_sndcnt) {
16558 					len = rack->r_ctl.rc_prr_sndcnt;
16559 				}
16560 				if (len > 0) {
16561 					sub_from_prr = 1;
16562 					counter_u64_add(rack_rtm_prr_newdata, 1);
16563 				}
16564 			}
16565 			if (len > segsiz) {
16566 				/*
16567 				 * We should never send more than a MSS when
16568 				 * retransmitting or sending new data in prr
16569 				 * mode unless the override flag is on. Most
16570 				 * likely the PRR algorithm is not going to
16571 				 * let us send a lot as well :-)
16572 				 */
16573 				if (rack->r_ctl.rc_prr_sendalot == 0) {
16574 					len = segsiz;
16575 				}
16576 			} else if (len < segsiz) {
16577 				/*
16578 				 * Do we send any? The idea here is if the
16579 				 * send empty's the socket buffer we want to
16580 				 * do it. However if not then lets just wait
16581 				 * for our prr_sndcnt to get bigger.
16582 				 */
16583 				long leftinsb;
16584 
16585 				leftinsb = sbavail(sb) - sb_offset;
16586 				if (leftinsb > len) {
16587 					/* This send does not empty the sb */
16588 					len = 0;
16589 				}
16590 			}
16591 		}
16592 	} else if (!TCPS_HAVEESTABLISHED(tp->t_state)) {
16593 		/*
16594 		 * If you have not established
16595 		 * and are not doing FAST OPEN
16596 		 * no data please.
16597 		 */
16598 		if ((sack_rxmit == 0) &&
16599 		    (!IS_FASTOPEN(tp->t_flags))){
16600 			len = 0;
16601 			sb_offset = 0;
16602 		}
16603 	}
16604 	if (prefetch_so_done == 0) {
16605 		kern_prefetch(so, &prefetch_so_done);
16606 		prefetch_so_done = 1;
16607 	}
16608 	/*
16609 	 * Lop off SYN bit if it has already been sent.  However, if this is
16610 	 * SYN-SENT state and if segment contains data and if we don't know
16611 	 * that foreign host supports TAO, suppress sending segment.
16612 	 */
16613 	if ((flags & TH_SYN) && SEQ_GT(tp->snd_nxt, tp->snd_una) &&
16614 	    ((sack_rxmit == 0) && (tp->t_rxtshift == 0))) {
16615 		/*
16616 		 * When sending additional segments following a TFO SYN|ACK,
16617 		 * do not include the SYN bit.
16618 		 */
16619 		if (IS_FASTOPEN(tp->t_flags) &&
16620 		    (tp->t_state == TCPS_SYN_RECEIVED))
16621 			flags &= ~TH_SYN;
16622 	}
16623 	/*
16624 	 * Be careful not to send data and/or FIN on SYN segments. This
16625 	 * measure is needed to prevent interoperability problems with not
16626 	 * fully conformant TCP implementations.
16627 	 */
16628 	if ((flags & TH_SYN) && (tp->t_flags & TF_NOOPT)) {
16629 		len = 0;
16630 		flags &= ~TH_FIN;
16631 	}
16632 	/*
16633 	 * On TFO sockets, ensure no data is sent in the following cases:
16634 	 *
16635 	 *  - When retransmitting SYN|ACK on a passively-created socket
16636 	 *
16637 	 *  - When retransmitting SYN on an actively created socket
16638 	 *
16639 	 *  - When sending a zero-length cookie (cookie request) on an
16640 	 *    actively created socket
16641 	 *
16642 	 *  - When the socket is in the CLOSED state (RST is being sent)
16643 	 */
16644 	if (IS_FASTOPEN(tp->t_flags) &&
16645 	    (((flags & TH_SYN) && (tp->t_rxtshift > 0)) ||
16646 	     ((tp->t_state == TCPS_SYN_SENT) &&
16647 	      (tp->t_tfo_client_cookie_len == 0)) ||
16648 	     (flags & TH_RST))) {
16649 		sack_rxmit = 0;
16650 		len = 0;
16651 	}
16652 	/* Without fast-open there should never be data sent on a SYN */
16653 	if ((flags & TH_SYN) && (!IS_FASTOPEN(tp->t_flags))) {
16654 		tp->snd_nxt = tp->iss;
16655 		len = 0;
16656 	}
16657 	if ((len > segsiz) && (tcp_dsack_block_exists(tp))) {
16658 		/* We only send 1 MSS if we have a DSACK block */
16659 		add_flag |= RACK_SENT_W_DSACK;
16660 		len = segsiz;
16661 	}
16662 	orig_len = len;
16663 	if (len <= 0) {
16664 		/*
16665 		 * If FIN has been sent but not acked, but we haven't been
16666 		 * called to retransmit, len will be < 0.  Otherwise, window
16667 		 * shrank after we sent into it.  If window shrank to 0,
16668 		 * cancel pending retransmit, pull snd_nxt back to (closed)
16669 		 * window, and set the persist timer if it isn't already
16670 		 * going.  If the window didn't close completely, just wait
16671 		 * for an ACK.
16672 		 *
16673 		 * We also do a general check here to ensure that we will
16674 		 * set the persist timer when we have data to send, but a
16675 		 * 0-byte window. This makes sure the persist timer is set
16676 		 * even if the packet hits one of the "goto send" lines
16677 		 * below.
16678 		 */
16679 		len = 0;
16680 		if ((tp->snd_wnd == 0) &&
16681 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
16682 		    (tp->snd_una == tp->snd_max) &&
16683 		    (sb_offset < (int)sbavail(sb))) {
16684 			rack_enter_persist(tp, rack, cts);
16685 		}
16686 	} else if ((rsm == NULL) &&
16687 		   (doing_tlp == 0) &&
16688 		   (len < pace_max_seg)) {
16689 		/*
16690 		 * We are not sending a maximum sized segment for
16691 		 * some reason. Should we not send anything (think
16692 		 * sws or persists)?
16693 		 */
16694 		if ((tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
16695 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
16696 		    (len < minseg) &&
16697 		    (len < (int)(sbavail(sb) - sb_offset))) {
16698 			/*
16699 			 * Here the rwnd is less than
16700 			 * the minimum pacing size, this is not a retransmit,
16701 			 * we are established and
16702 			 * the send is not the last in the socket buffer
16703 			 * we send nothing, and we may enter persists
16704 			 * if nothing is outstanding.
16705 			 */
16706 			len = 0;
16707 			if (tp->snd_max == tp->snd_una) {
16708 				/*
16709 				 * Nothing out we can
16710 				 * go into persists.
16711 				 */
16712 				rack_enter_persist(tp, rack, cts);
16713 			}
16714 		     } else if ((cwnd_to_use >= max(minseg, (segsiz * 4))) &&
16715 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
16716 			   (len < (int)(sbavail(sb) - sb_offset)) &&
16717 			   (len < minseg)) {
16718 			/*
16719 			 * Here we are not retransmitting, and
16720 			 * the cwnd is not so small that we could
16721 			 * not send at least a min size (rxt timer
16722 			 * not having gone off), We have 2 segments or
16723 			 * more already in flight, its not the tail end
16724 			 * of the socket buffer  and the cwnd is blocking
16725 			 * us from sending out a minimum pacing segment size.
16726 			 * Lets not send anything.
16727 			 */
16728 			len = 0;
16729 		} else if (((tp->snd_wnd - ctf_outstanding(tp)) <
16730 			    min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
16731 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
16732 			   (len < (int)(sbavail(sb) - sb_offset)) &&
16733 			   (TCPS_HAVEESTABLISHED(tp->t_state))) {
16734 			/*
16735 			 * Here we have a send window but we have
16736 			 * filled it up and we can't send another pacing segment.
16737 			 * We also have in flight more than 2 segments
16738 			 * and we are not completing the sb i.e. we allow
16739 			 * the last bytes of the sb to go out even if
16740 			 * its not a full pacing segment.
16741 			 */
16742 			len = 0;
16743 		} else if ((rack->r_ctl.crte != NULL) &&
16744 			   (tp->snd_wnd >= (pace_max_seg * max(1, rack_hw_rwnd_factor))) &&
16745 			   (cwnd_to_use >= (pace_max_seg + (4 * segsiz))) &&
16746 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) >= (2 * segsiz)) &&
16747 			   (len < (int)(sbavail(sb) - sb_offset))) {
16748 			/*
16749 			 * Here we are doing hardware pacing, this is not a TLP,
16750 			 * we are not sending a pace max segment size, there is rwnd
16751 			 * room to send at least N pace_max_seg, the cwnd is greater
16752 			 * than or equal to a full pacing segments plus 4 mss and we have 2 or
16753 			 * more segments in flight and its not the tail of the socket buffer.
16754 			 *
16755 			 * We don't want to send instead we need to get more ack's in to
16756 			 * allow us to send a full pacing segment. Normally, if we are pacing
16757 			 * about the right speed, we should have finished our pacing
16758 			 * send as most of the acks have come back if we are at the
16759 			 * right rate. This is a bit fuzzy since return path delay
16760 			 * can delay the acks, which is why we want to make sure we
16761 			 * have cwnd space to have a bit more than a max pace segments in flight.
16762 			 *
16763 			 * If we have not gotten our acks back we are pacing at too high a
16764 			 * rate delaying will not hurt and will bring our GP estimate down by
16765 			 * injecting the delay. If we don't do this we will send
16766 			 * 2 MSS out in response to the acks being clocked in which
16767 			 * defeats the point of hw-pacing (i.e. to help us get
16768 			 * larger TSO's out).
16769 			 */
16770 			len = 0;
16771 
16772 		}
16773 
16774 	}
16775 	/* len will be >= 0 after this point. */
16776 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
16777 	rack_sndbuf_autoscale(rack);
16778 	/*
16779 	 * Decide if we can use TCP Segmentation Offloading (if supported by
16780 	 * hardware).
16781 	 *
16782 	 * TSO may only be used if we are in a pure bulk sending state.  The
16783 	 * presence of TCP-MD5, SACK retransmits, SACK advertizements and IP
16784 	 * options prevent using TSO.  With TSO the TCP header is the same
16785 	 * (except for the sequence number) for all generated packets.  This
16786 	 * makes it impossible to transmit any options which vary per
16787 	 * generated segment or packet.
16788 	 *
16789 	 * IPv4 handling has a clear separation of ip options and ip header
16790 	 * flags while IPv6 combines both in in6p_outputopts. ip6_optlen() does
16791 	 * the right thing below to provide length of just ip options and thus
16792 	 * checking for ipoptlen is enough to decide if ip options are present.
16793 	 */
16794 	ipoptlen = 0;
16795 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
16796 	/*
16797 	 * Pre-calculate here as we save another lookup into the darknesses
16798 	 * of IPsec that way and can actually decide if TSO is ok.
16799 	 */
16800 #ifdef INET6
16801 	if (isipv6 && IPSEC_ENABLED(ipv6))
16802 		ipsec_optlen = IPSEC_HDRSIZE(ipv6, tp->t_inpcb);
16803 #ifdef INET
16804 	else
16805 #endif
16806 #endif				/* INET6 */
16807 #ifdef INET
16808 		if (IPSEC_ENABLED(ipv4))
16809 			ipsec_optlen = IPSEC_HDRSIZE(ipv4, tp->t_inpcb);
16810 #endif				/* INET */
16811 #endif
16812 
16813 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
16814 	ipoptlen += ipsec_optlen;
16815 #endif
16816 	if ((tp->t_flags & TF_TSO) && V_tcp_do_tso && len > segsiz &&
16817 	    (tp->t_port == 0) &&
16818 	    ((tp->t_flags & TF_SIGNATURE) == 0) &&
16819 	    tp->rcv_numsacks == 0 && sack_rxmit == 0 &&
16820 	    ipoptlen == 0)
16821 		tso = 1;
16822 	{
16823 		uint32_t outstanding;
16824 
16825 		outstanding = tp->snd_max - tp->snd_una;
16826 		if (tp->t_flags & TF_SENTFIN) {
16827 			/*
16828 			 * If we sent a fin, snd_max is 1 higher than
16829 			 * snd_una
16830 			 */
16831 			outstanding--;
16832 		}
16833 		if (sack_rxmit) {
16834 			if ((rsm->r_flags & RACK_HAS_FIN) == 0)
16835 				flags &= ~TH_FIN;
16836 		} else {
16837 			if (SEQ_LT(tp->snd_nxt + len, tp->snd_una +
16838 				   sbused(sb)))
16839 				flags &= ~TH_FIN;
16840 		}
16841 	}
16842 	recwin = lmin(lmax(sbspace(&so->so_rcv), 0),
16843 	    (long)TCP_MAXWIN << tp->rcv_scale);
16844 
16845 	/*
16846 	 * Sender silly window avoidance.   We transmit under the following
16847 	 * conditions when len is non-zero:
16848 	 *
16849 	 * - We have a full segment (or more with TSO) - This is the last
16850 	 * buffer in a write()/send() and we are either idle or running
16851 	 * NODELAY - we've timed out (e.g. persist timer) - we have more
16852 	 * then 1/2 the maximum send window's worth of data (receiver may be
16853 	 * limited the window size) - we need to retransmit
16854 	 */
16855 	if (len) {
16856 		if (len >= segsiz) {
16857 			goto send;
16858 		}
16859 		/*
16860 		 * NOTE! on localhost connections an 'ack' from the remote
16861 		 * end may occur synchronously with the output and cause us
16862 		 * to flush a buffer queued with moretocome.  XXX
16863 		 *
16864 		 */
16865 		if (!(tp->t_flags & TF_MORETOCOME) &&	/* normal case */
16866 		    (idle || (tp->t_flags & TF_NODELAY)) &&
16867 		    ((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
16868 		    (tp->t_flags & TF_NOPUSH) == 0) {
16869 			pass = 2;
16870 			goto send;
16871 		}
16872 		if ((tp->snd_una == tp->snd_max) && len) {	/* Nothing outstanding */
16873 			pass = 22;
16874 			goto send;
16875 		}
16876 		if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0) {
16877 			pass = 4;
16878 			goto send;
16879 		}
16880 		if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {	/* retransmit case */
16881 			pass = 5;
16882 			goto send;
16883 		}
16884 		if (sack_rxmit) {
16885 			pass = 6;
16886 			goto send;
16887 		}
16888 		if (((tp->snd_wnd - ctf_outstanding(tp)) < segsiz) &&
16889 		    (ctf_outstanding(tp) < (segsiz * 2))) {
16890 			/*
16891 			 * We have less than two MSS outstanding (delayed ack)
16892 			 * and our rwnd will not let us send a full sized
16893 			 * MSS. Lets go ahead and let this small segment
16894 			 * out because we want to try to have at least two
16895 			 * packets inflight to not be caught by delayed ack.
16896 			 */
16897 			pass = 12;
16898 			goto send;
16899 		}
16900 	}
16901 	/*
16902 	 * Sending of standalone window updates.
16903 	 *
16904 	 * Window updates are important when we close our window due to a
16905 	 * full socket buffer and are opening it again after the application
16906 	 * reads data from it.  Once the window has opened again and the
16907 	 * remote end starts to send again the ACK clock takes over and
16908 	 * provides the most current window information.
16909 	 *
16910 	 * We must avoid the silly window syndrome whereas every read from
16911 	 * the receive buffer, no matter how small, causes a window update
16912 	 * to be sent.  We also should avoid sending a flurry of window
16913 	 * updates when the socket buffer had queued a lot of data and the
16914 	 * application is doing small reads.
16915 	 *
16916 	 * Prevent a flurry of pointless window updates by only sending an
16917 	 * update when we can increase the advertized window by more than
16918 	 * 1/4th of the socket buffer capacity.  When the buffer is getting
16919 	 * full or is very small be more aggressive and send an update
16920 	 * whenever we can increase by two mss sized segments. In all other
16921 	 * situations the ACK's to new incoming data will carry further
16922 	 * window increases.
16923 	 *
16924 	 * Don't send an independent window update if a delayed ACK is
16925 	 * pending (it will get piggy-backed on it) or the remote side
16926 	 * already has done a half-close and won't send more data.  Skip
16927 	 * this if the connection is in T/TCP half-open state.
16928 	 */
16929 	if (recwin > 0 && !(tp->t_flags & TF_NEEDSYN) &&
16930 	    !(tp->t_flags & TF_DELACK) &&
16931 	    !TCPS_HAVERCVDFIN(tp->t_state)) {
16932 		/*
16933 		 * "adv" is the amount we could increase the window, taking
16934 		 * into account that we are limited by TCP_MAXWIN <<
16935 		 * tp->rcv_scale.
16936 		 */
16937 		int32_t adv;
16938 		int oldwin;
16939 
16940 		adv = recwin;
16941 		if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt)) {
16942 			oldwin = (tp->rcv_adv - tp->rcv_nxt);
16943 			if (adv > oldwin)
16944 			    adv -= oldwin;
16945 			else {
16946 				/* We can't increase the window */
16947 				adv = 0;
16948 			}
16949 		} else
16950 			oldwin = 0;
16951 
16952 		/*
16953 		 * If the new window size ends up being the same as or less
16954 		 * than the old size when it is scaled, then don't force
16955 		 * a window update.
16956 		 */
16957 		if (oldwin >> tp->rcv_scale >= (adv + oldwin) >> tp->rcv_scale)
16958 			goto dontupdate;
16959 
16960 		if (adv >= (int32_t)(2 * segsiz) &&
16961 		    (adv >= (int32_t)(so->so_rcv.sb_hiwat / 4) ||
16962 		     recwin <= (int32_t)(so->so_rcv.sb_hiwat / 8) ||
16963 		     so->so_rcv.sb_hiwat <= 8 * segsiz)) {
16964 			pass = 7;
16965 			goto send;
16966 		}
16967 		if (2 * adv >= (int32_t) so->so_rcv.sb_hiwat) {
16968 			pass = 23;
16969 			goto send;
16970 		}
16971 	}
16972 dontupdate:
16973 
16974 	/*
16975 	 * Send if we owe the peer an ACK, RST, SYN, or urgent data.  ACKNOW
16976 	 * is also a catch-all for the retransmit timer timeout case.
16977 	 */
16978 	if (tp->t_flags & TF_ACKNOW) {
16979 		pass = 8;
16980 		goto send;
16981 	}
16982 	if (((flags & TH_SYN) && (tp->t_flags & TF_NEEDSYN) == 0)) {
16983 		pass = 9;
16984 		goto send;
16985 	}
16986 	/*
16987 	 * If our state indicates that FIN should be sent and we have not
16988 	 * yet done so, then we need to send.
16989 	 */
16990 	if ((flags & TH_FIN) &&
16991 	    (tp->snd_nxt == tp->snd_una)) {
16992 		pass = 11;
16993 		goto send;
16994 	}
16995 	/*
16996 	 * No reason to send a segment, just return.
16997 	 */
16998 just_return:
16999 	SOCKBUF_UNLOCK(sb);
17000 just_return_nolock:
17001 	{
17002 		int app_limited = CTF_JR_SENT_DATA;
17003 
17004 		if (tot_len_this_send > 0) {
17005 			/* Make sure snd_nxt is up to max */
17006 			rack->r_ctl.fsb.recwin = recwin;
17007 			slot = rack_get_pacing_delay(rack, tp, tot_len_this_send, NULL, segsiz);
17008 			if ((error == 0) &&
17009 			    rack_use_rfo &&
17010 			    ((flags & (TH_SYN|TH_FIN)) == 0) &&
17011 			    (ipoptlen == 0) &&
17012 			    (tp->snd_nxt == tp->snd_max) &&
17013 			    (tp->rcv_numsacks == 0) &&
17014 			    rack->r_fsb_inited &&
17015 			    TCPS_HAVEESTABLISHED(tp->t_state) &&
17016 			    (rack->r_must_retran == 0) &&
17017 			    ((tp->t_flags & TF_NEEDFIN) == 0) &&
17018 			    (len > 0) && (orig_len > 0) &&
17019 			    (orig_len > len) &&
17020 			    ((orig_len - len) >= segsiz) &&
17021 			    ((optlen == 0) ||
17022 			     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
17023 				/* We can send at least one more MSS using our fsb */
17024 
17025 				rack->r_fast_output = 1;
17026 				rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
17027 				rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
17028 				rack->r_ctl.fsb.tcp_flags = flags;
17029 				rack->r_ctl.fsb.left_to_send = orig_len - len;
17030 				KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
17031 					("rack:%p left_to_send:%u sbavail:%u out:%u",
17032 					rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
17033 					 (tp->snd_max - tp->snd_una)));
17034 				if (rack->r_ctl.fsb.left_to_send < segsiz)
17035 					rack->r_fast_output = 0;
17036 				else {
17037 					if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
17038 						rack->r_ctl.fsb.rfo_apply_push = 1;
17039 					else
17040 						rack->r_ctl.fsb.rfo_apply_push = 0;
17041 				}
17042 			} else
17043 				rack->r_fast_output = 0;
17044 
17045 
17046 			rack_log_fsb(rack, tp, so, flags,
17047 				     ipoptlen, orig_len, len, 0,
17048 				     1, optlen, __LINE__, 1);
17049 			if (SEQ_GT(tp->snd_max, tp->snd_nxt))
17050 				tp->snd_nxt = tp->snd_max;
17051 		} else {
17052 			int end_window = 0;
17053 			uint32_t seq = tp->gput_ack;
17054 
17055 			rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
17056 			if (rsm) {
17057 				/*
17058 				 * Mark the last sent that we just-returned (hinting
17059 				 * that delayed ack may play a role in any rtt measurement).
17060 				 */
17061 				rsm->r_just_ret = 1;
17062 			}
17063 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_JUSTRET], 1);
17064 			rack->r_ctl.rc_agg_delayed = 0;
17065 			rack->r_early = 0;
17066 			rack->r_late = 0;
17067 			rack->r_ctl.rc_agg_early = 0;
17068 			if ((ctf_outstanding(tp) +
17069 			     min(max(segsiz, (rack->r_ctl.rc_high_rwnd/2)),
17070 				 minseg)) >= tp->snd_wnd) {
17071 				/* We are limited by the rwnd */
17072 				app_limited = CTF_JR_RWND_LIMITED;
17073 				if (IN_FASTRECOVERY(tp->t_flags))
17074 				    rack->r_ctl.rc_prr_sndcnt = 0;
17075 			} else if (ctf_outstanding(tp) >= sbavail(sb)) {
17076 				/* We are limited by whats available -- app limited */
17077 				app_limited = CTF_JR_APP_LIMITED;
17078 				if (IN_FASTRECOVERY(tp->t_flags))
17079 				    rack->r_ctl.rc_prr_sndcnt = 0;
17080 			} else if ((idle == 0) &&
17081 				   ((tp->t_flags & TF_NODELAY) == 0) &&
17082 				   ((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
17083 				   (len < segsiz)) {
17084 				/*
17085 				 * No delay is not on and the
17086 				 * user is sending less than 1MSS. This
17087 				 * brings out SWS avoidance so we
17088 				 * don't send. Another app-limited case.
17089 				 */
17090 				app_limited = CTF_JR_APP_LIMITED;
17091 			} else if (tp->t_flags & TF_NOPUSH) {
17092 				/*
17093 				 * The user has requested no push of
17094 				 * the last segment and we are
17095 				 * at the last segment. Another app
17096 				 * limited case.
17097 				 */
17098 				app_limited = CTF_JR_APP_LIMITED;
17099 			} else if ((ctf_outstanding(tp) + minseg) > cwnd_to_use) {
17100 				/* Its the cwnd */
17101 				app_limited = CTF_JR_CWND_LIMITED;
17102 			} else if (IN_FASTRECOVERY(tp->t_flags) &&
17103 				   (rack->rack_no_prr == 0) &&
17104 				   (rack->r_ctl.rc_prr_sndcnt < segsiz)) {
17105 				app_limited = CTF_JR_PRR;
17106 			} else {
17107 				/* Now why here are we not sending? */
17108 #ifdef NOW
17109 #ifdef INVARIANTS
17110 				panic("rack:%p hit JR_ASSESSING case cwnd_to_use:%u?", rack, cwnd_to_use);
17111 #endif
17112 #endif
17113 				app_limited = CTF_JR_ASSESSING;
17114 			}
17115 			/*
17116 			 * App limited in some fashion, for our pacing GP
17117 			 * measurements we don't want any gap (even cwnd).
17118 			 * Close  down the measurement window.
17119 			 */
17120 			if (rack_cwnd_block_ends_measure &&
17121 			    ((app_limited == CTF_JR_CWND_LIMITED) ||
17122 			     (app_limited == CTF_JR_PRR))) {
17123 				/*
17124 				 * The reason we are not sending is
17125 				 * the cwnd (or prr). We have been configured
17126 				 * to end the measurement window in
17127 				 * this case.
17128 				 */
17129 				end_window = 1;
17130 			} else if (rack_rwnd_block_ends_measure &&
17131 				   (app_limited == CTF_JR_RWND_LIMITED)) {
17132 				/*
17133 				 * We are rwnd limited and have been
17134 				 * configured to end the measurement
17135 				 * window in this case.
17136 				 */
17137 				end_window = 1;
17138 			} else if (app_limited == CTF_JR_APP_LIMITED) {
17139 				/*
17140 				 * A true application limited period, we have
17141 				 * ran out of data.
17142 				 */
17143 				end_window = 1;
17144 			} else if (app_limited == CTF_JR_ASSESSING) {
17145 				/*
17146 				 * In the assessing case we hit the end of
17147 				 * the if/else and had no known reason
17148 				 * This will panic us under invariants..
17149 				 *
17150 				 * If we get this out in logs we need to
17151 				 * investagate which reason we missed.
17152 				 */
17153 				end_window = 1;
17154 			}
17155 			if (end_window) {
17156 				uint8_t log = 0;
17157 
17158 				if ((tp->t_flags & TF_GPUTINPROG) &&
17159 				    SEQ_GT(tp->gput_ack, tp->snd_max)) {
17160 					/* Mark the last packet has app limited */
17161 					tp->gput_ack = tp->snd_max;
17162 					log = 1;
17163 				}
17164 				rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
17165 				if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
17166 					if (rack->r_ctl.rc_app_limited_cnt == 0)
17167 						rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
17168 					else {
17169 						/*
17170 						 * Go out to the end app limited and mark
17171 						 * this new one as next and move the end_appl up
17172 						 * to this guy.
17173 						 */
17174 						if (rack->r_ctl.rc_end_appl)
17175 							rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
17176 						rack->r_ctl.rc_end_appl = rsm;
17177 					}
17178 					rsm->r_flags |= RACK_APP_LIMITED;
17179 					rack->r_ctl.rc_app_limited_cnt++;
17180 				}
17181 				if (log)
17182 					rack_log_pacing_delay_calc(rack,
17183 								   rack->r_ctl.rc_app_limited_cnt, seq,
17184 								   tp->gput_ack, 0, 0, 4, __LINE__, NULL);
17185 			}
17186 		}
17187 		if (slot) {
17188 			/* set the rack tcb into the slot N */
17189 			counter_u64_add(rack_paced_segments, 1);
17190 		} else if (tot_len_this_send) {
17191 			counter_u64_add(rack_unpaced_segments, 1);
17192 		}
17193 		/* Check if we need to go into persists or not */
17194 		if ((tp->snd_max == tp->snd_una) &&
17195 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
17196 		    sbavail(sb) &&
17197 		    (sbavail(sb) > tp->snd_wnd) &&
17198 		    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg))) {
17199 			/* Yes lets make sure to move to persist before timer-start */
17200 			rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
17201 		}
17202 		rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, sup_rack);
17203 		rack_log_type_just_return(rack, cts, tot_len_this_send, slot, hpts_calling, app_limited, cwnd_to_use);
17204 	}
17205 #ifdef NETFLIX_SHARED_CWND
17206 	if ((sbavail(sb) == 0) &&
17207 	    rack->r_ctl.rc_scw) {
17208 		tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
17209 		rack->rack_scwnd_is_idle = 1;
17210 	}
17211 #endif
17212 #ifdef TCP_ACCOUNTING
17213 	if (tot_len_this_send > 0) {
17214 		crtsc = get_cyclecount();
17215 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17216 			tp->tcp_cnt_counters[SND_OUT_DATA]++;
17217 		}
17218 		counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], 1);
17219 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17220 			tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
17221 		}
17222 		counter_u64_add(tcp_proc_time[SND_OUT_DATA], (crtsc - ts_val));
17223 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17224 			tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len_this_send + segsiz - 1) / segsiz);
17225 		}
17226 		counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((tot_len_this_send + segsiz - 1) / segsiz));
17227 	} else {
17228 		crtsc = get_cyclecount();
17229 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17230 			tp->tcp_cnt_counters[SND_LIMITED]++;
17231 		}
17232 		counter_u64_add(tcp_cnt_counters[SND_LIMITED], 1);
17233 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17234 			tp->tcp_proc_time[SND_LIMITED] += (crtsc - ts_val);
17235 		}
17236 		counter_u64_add(tcp_proc_time[SND_LIMITED], (crtsc - ts_val));
17237 	}
17238 	sched_unpin();
17239 #endif
17240 	return (0);
17241 
17242 send:
17243 	if (rsm || sack_rxmit)
17244 		counter_u64_add(rack_nfto_resend, 1);
17245 	else
17246 		counter_u64_add(rack_non_fto_send, 1);
17247 	if ((flags & TH_FIN) &&
17248 	    sbavail(sb)) {
17249 		/*
17250 		 * We do not transmit a FIN
17251 		 * with data outstanding. We
17252 		 * need to make it so all data
17253 		 * is acked first.
17254 		 */
17255 		flags &= ~TH_FIN;
17256 	}
17257 	/* Enforce stack imposed max seg size if we have one */
17258 	if (rack->r_ctl.rc_pace_max_segs &&
17259 	    (len > rack->r_ctl.rc_pace_max_segs)) {
17260 		mark = 1;
17261 		len = rack->r_ctl.rc_pace_max_segs;
17262 	}
17263 	SOCKBUF_LOCK_ASSERT(sb);
17264 	if (len > 0) {
17265 		if (len >= segsiz)
17266 			tp->t_flags2 |= TF2_PLPMTU_MAXSEGSNT;
17267 		else
17268 			tp->t_flags2 &= ~TF2_PLPMTU_MAXSEGSNT;
17269 	}
17270 	/*
17271 	 * Before ESTABLISHED, force sending of initial options unless TCP
17272 	 * set not to do any options. NOTE: we assume that the IP/TCP header
17273 	 * plus TCP options always fit in a single mbuf, leaving room for a
17274 	 * maximum link header, i.e. max_linkhdr + sizeof (struct tcpiphdr)
17275 	 * + optlen <= MCLBYTES
17276 	 */
17277 	optlen = 0;
17278 #ifdef INET6
17279 	if (isipv6)
17280 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
17281 	else
17282 #endif
17283 		hdrlen = sizeof(struct tcpiphdr);
17284 
17285 	/*
17286 	 * Compute options for segment. We only have to care about SYN and
17287 	 * established connection segments.  Options for SYN-ACK segments
17288 	 * are handled in TCP syncache.
17289 	 */
17290 	to.to_flags = 0;
17291 	if ((tp->t_flags & TF_NOOPT) == 0) {
17292 		/* Maximum segment size. */
17293 		if (flags & TH_SYN) {
17294 			tp->snd_nxt = tp->iss;
17295 			to.to_mss = tcp_mssopt(&inp->inp_inc);
17296 			if (tp->t_port)
17297 				to.to_mss -= V_tcp_udp_tunneling_overhead;
17298 			to.to_flags |= TOF_MSS;
17299 
17300 			/*
17301 			 * On SYN or SYN|ACK transmits on TFO connections,
17302 			 * only include the TFO option if it is not a
17303 			 * retransmit, as the presence of the TFO option may
17304 			 * have caused the original SYN or SYN|ACK to have
17305 			 * been dropped by a middlebox.
17306 			 */
17307 			if (IS_FASTOPEN(tp->t_flags) &&
17308 			    (tp->t_rxtshift == 0)) {
17309 				if (tp->t_state == TCPS_SYN_RECEIVED) {
17310 					to.to_tfo_len = TCP_FASTOPEN_COOKIE_LEN;
17311 					to.to_tfo_cookie =
17312 						(u_int8_t *)&tp->t_tfo_cookie.server;
17313 					to.to_flags |= TOF_FASTOPEN;
17314 					wanted_cookie = 1;
17315 				} else if (tp->t_state == TCPS_SYN_SENT) {
17316 					to.to_tfo_len =
17317 						tp->t_tfo_client_cookie_len;
17318 					to.to_tfo_cookie =
17319 						tp->t_tfo_cookie.client;
17320 					to.to_flags |= TOF_FASTOPEN;
17321 					wanted_cookie = 1;
17322 					/*
17323 					 * If we wind up having more data to
17324 					 * send with the SYN than can fit in
17325 					 * one segment, don't send any more
17326 					 * until the SYN|ACK comes back from
17327 					 * the other end.
17328 					 */
17329 					sendalot = 0;
17330 				}
17331 			}
17332 		}
17333 		/* Window scaling. */
17334 		if ((flags & TH_SYN) && (tp->t_flags & TF_REQ_SCALE)) {
17335 			to.to_wscale = tp->request_r_scale;
17336 			to.to_flags |= TOF_SCALE;
17337 		}
17338 		/* Timestamps. */
17339 		if ((tp->t_flags & TF_RCVD_TSTMP) ||
17340 		    ((flags & TH_SYN) && (tp->t_flags & TF_REQ_TSTMP))) {
17341 			to.to_tsval = ms_cts + tp->ts_offset;
17342 			to.to_tsecr = tp->ts_recent;
17343 			to.to_flags |= TOF_TS;
17344 		}
17345 		/* Set receive buffer autosizing timestamp. */
17346 		if (tp->rfbuf_ts == 0 &&
17347 		    (so->so_rcv.sb_flags & SB_AUTOSIZE))
17348 			tp->rfbuf_ts = tcp_ts_getticks();
17349 		/* Selective ACK's. */
17350 		if (tp->t_flags & TF_SACK_PERMIT) {
17351 			if (flags & TH_SYN)
17352 				to.to_flags |= TOF_SACKPERM;
17353 			else if (TCPS_HAVEESTABLISHED(tp->t_state) &&
17354 				 tp->rcv_numsacks > 0) {
17355 				to.to_flags |= TOF_SACK;
17356 				to.to_nsacks = tp->rcv_numsacks;
17357 				to.to_sacks = (u_char *)tp->sackblks;
17358 			}
17359 		}
17360 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
17361 		/* TCP-MD5 (RFC2385). */
17362 		if (tp->t_flags & TF_SIGNATURE)
17363 			to.to_flags |= TOF_SIGNATURE;
17364 #endif				/* TCP_SIGNATURE */
17365 
17366 		/* Processing the options. */
17367 		hdrlen += optlen = tcp_addoptions(&to, opt);
17368 		/*
17369 		 * If we wanted a TFO option to be added, but it was unable
17370 		 * to fit, ensure no data is sent.
17371 		 */
17372 		if (IS_FASTOPEN(tp->t_flags) && wanted_cookie &&
17373 		    !(to.to_flags & TOF_FASTOPEN))
17374 			len = 0;
17375 	}
17376 	if (tp->t_port) {
17377 		if (V_tcp_udp_tunneling_port == 0) {
17378 			/* The port was removed?? */
17379 			SOCKBUF_UNLOCK(&so->so_snd);
17380 #ifdef TCP_ACCOUNTING
17381 			crtsc = get_cyclecount();
17382 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17383 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
17384 			}
17385 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
17386 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17387 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
17388 			}
17389 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
17390 			sched_unpin();
17391 #endif
17392 			return (EHOSTUNREACH);
17393 		}
17394 		hdrlen += sizeof(struct udphdr);
17395 	}
17396 #ifdef INET6
17397 	if (isipv6)
17398 		ipoptlen = ip6_optlen(tp->t_inpcb);
17399 	else
17400 #endif
17401 		if (tp->t_inpcb->inp_options)
17402 			ipoptlen = tp->t_inpcb->inp_options->m_len -
17403 				offsetof(struct ipoption, ipopt_list);
17404 		else
17405 			ipoptlen = 0;
17406 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
17407 	ipoptlen += ipsec_optlen;
17408 #endif
17409 
17410 	/*
17411 	 * Adjust data length if insertion of options will bump the packet
17412 	 * length beyond the t_maxseg length. Clear the FIN bit because we
17413 	 * cut off the tail of the segment.
17414 	 */
17415 	if (len + optlen + ipoptlen > tp->t_maxseg) {
17416 		if (tso) {
17417 			uint32_t if_hw_tsomax;
17418 			uint32_t moff;
17419 			int32_t max_len;
17420 
17421 			/* extract TSO information */
17422 			if_hw_tsomax = tp->t_tsomax;
17423 			if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
17424 			if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
17425 			KASSERT(ipoptlen == 0,
17426 				("%s: TSO can't do IP options", __func__));
17427 
17428 			/*
17429 			 * Check if we should limit by maximum payload
17430 			 * length:
17431 			 */
17432 			if (if_hw_tsomax != 0) {
17433 				/* compute maximum TSO length */
17434 				max_len = (if_hw_tsomax - hdrlen -
17435 					   max_linkhdr);
17436 				if (max_len <= 0) {
17437 					len = 0;
17438 				} else if (len > max_len) {
17439 					sendalot = 1;
17440 					len = max_len;
17441 					mark = 2;
17442 				}
17443 			}
17444 			/*
17445 			 * Prevent the last segment from being fractional
17446 			 * unless the send sockbuf can be emptied:
17447 			 */
17448 			max_len = (tp->t_maxseg - optlen);
17449 			if ((sb_offset + len) < sbavail(sb)) {
17450 				moff = len % (u_int)max_len;
17451 				if (moff != 0) {
17452 					mark = 3;
17453 					len -= moff;
17454 				}
17455 			}
17456 			/*
17457 			 * In case there are too many small fragments don't
17458 			 * use TSO:
17459 			 */
17460 			if (len <= segsiz) {
17461 				mark = 4;
17462 				tso = 0;
17463 			}
17464 			/*
17465 			 * Send the FIN in a separate segment after the bulk
17466 			 * sending is done. We don't trust the TSO
17467 			 * implementations to clear the FIN flag on all but
17468 			 * the last segment.
17469 			 */
17470 			if (tp->t_flags & TF_NEEDFIN) {
17471 				sendalot = 4;
17472 			}
17473 		} else {
17474 			mark = 5;
17475 			if (optlen + ipoptlen >= tp->t_maxseg) {
17476 				/*
17477 				 * Since we don't have enough space to put
17478 				 * the IP header chain and the TCP header in
17479 				 * one packet as required by RFC 7112, don't
17480 				 * send it. Also ensure that at least one
17481 				 * byte of the payload can be put into the
17482 				 * TCP segment.
17483 				 */
17484 				SOCKBUF_UNLOCK(&so->so_snd);
17485 				error = EMSGSIZE;
17486 				sack_rxmit = 0;
17487 				goto out;
17488 			}
17489 			len = tp->t_maxseg - optlen - ipoptlen;
17490 			sendalot = 5;
17491 		}
17492 	} else {
17493 		tso = 0;
17494 		mark = 6;
17495 	}
17496 	KASSERT(len + hdrlen + ipoptlen <= IP_MAXPACKET,
17497 		("%s: len > IP_MAXPACKET", __func__));
17498 #ifdef DIAGNOSTIC
17499 #ifdef INET6
17500 	if (max_linkhdr + hdrlen > MCLBYTES)
17501 #else
17502 		if (max_linkhdr + hdrlen > MHLEN)
17503 #endif
17504 			panic("tcphdr too big");
17505 #endif
17506 
17507 	/*
17508 	 * This KASSERT is here to catch edge cases at a well defined place.
17509 	 * Before, those had triggered (random) panic conditions further
17510 	 * down.
17511 	 */
17512 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
17513 	if ((len == 0) &&
17514 	    (flags & TH_FIN) &&
17515 	    (sbused(sb))) {
17516 		/*
17517 		 * We have outstanding data, don't send a fin by itself!.
17518 		 */
17519 		goto just_return;
17520 	}
17521 	/*
17522 	 * Grab a header mbuf, attaching a copy of data to be transmitted,
17523 	 * and initialize the header from the template for sends on this
17524 	 * connection.
17525 	 */
17526 	hw_tls = (sb->sb_flags & SB_TLS_IFNET) != 0;
17527 	if (len) {
17528 		uint32_t max_val;
17529 		uint32_t moff;
17530 
17531 		if (rack->r_ctl.rc_pace_max_segs)
17532 			max_val = rack->r_ctl.rc_pace_max_segs;
17533 		else if (rack->rc_user_set_max_segs)
17534 			max_val = rack->rc_user_set_max_segs * segsiz;
17535 		else
17536 			max_val = len;
17537 		/*
17538 		 * We allow a limit on sending with hptsi.
17539 		 */
17540 		if (len > max_val) {
17541 			mark = 7;
17542 			len = max_val;
17543 		}
17544 #ifdef INET6
17545 		if (MHLEN < hdrlen + max_linkhdr)
17546 			m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
17547 		else
17548 #endif
17549 			m = m_gethdr(M_NOWAIT, MT_DATA);
17550 
17551 		if (m == NULL) {
17552 			SOCKBUF_UNLOCK(sb);
17553 			error = ENOBUFS;
17554 			sack_rxmit = 0;
17555 			goto out;
17556 		}
17557 		m->m_data += max_linkhdr;
17558 		m->m_len = hdrlen;
17559 
17560 		/*
17561 		 * Start the m_copy functions from the closest mbuf to the
17562 		 * sb_offset in the socket buffer chain.
17563 		 */
17564 		mb = sbsndptr_noadv(sb, sb_offset, &moff);
17565 		s_mb = mb;
17566 		s_moff = moff;
17567 		if (len <= MHLEN - hdrlen - max_linkhdr && !hw_tls) {
17568 			m_copydata(mb, moff, (int)len,
17569 				   mtod(m, caddr_t)+hdrlen);
17570 			if (SEQ_LT(tp->snd_nxt, tp->snd_max))
17571 				sbsndptr_adv(sb, mb, len);
17572 			m->m_len += len;
17573 		} else {
17574 			struct sockbuf *msb;
17575 
17576 			if (SEQ_LT(tp->snd_nxt, tp->snd_max))
17577 				msb = NULL;
17578 			else
17579 				msb = sb;
17580 			m->m_next = tcp_m_copym(
17581 				mb, moff, &len,
17582 				if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, msb,
17583 				((rsm == NULL) ? hw_tls : 0)
17584 #ifdef NETFLIX_COPY_ARGS
17585 				, &filled_all
17586 #endif
17587 				);
17588 			if (len <= (tp->t_maxseg - optlen)) {
17589 				/*
17590 				 * Must have ran out of mbufs for the copy
17591 				 * shorten it to no longer need tso. Lets
17592 				 * not put on sendalot since we are low on
17593 				 * mbufs.
17594 				 */
17595 				tso = 0;
17596 			}
17597 			if (m->m_next == NULL) {
17598 				SOCKBUF_UNLOCK(sb);
17599 				(void)m_free(m);
17600 				error = ENOBUFS;
17601 				sack_rxmit = 0;
17602 				goto out;
17603 			}
17604 		}
17605 		if (SEQ_LT(tp->snd_nxt, tp->snd_max) || sack_rxmit) {
17606 			if (rsm && (rsm->r_flags & RACK_TLP)) {
17607 				/*
17608 				 * TLP should not count in retran count, but
17609 				 * in its own bin
17610 				 */
17611 				counter_u64_add(rack_tlp_retran, 1);
17612 				counter_u64_add(rack_tlp_retran_bytes, len);
17613 			} else {
17614 				tp->t_sndrexmitpack++;
17615 				KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
17616 				KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
17617 			}
17618 #ifdef STATS
17619 			stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
17620 						 len);
17621 #endif
17622 		} else {
17623 			KMOD_TCPSTAT_INC(tcps_sndpack);
17624 			KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
17625 #ifdef STATS
17626 			stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
17627 						 len);
17628 #endif
17629 		}
17630 		/*
17631 		 * If we're sending everything we've got, set PUSH. (This
17632 		 * will keep happy those implementations which only give
17633 		 * data to the user when a buffer fills or a PUSH comes in.)
17634 		 */
17635 		if (sb_offset + len == sbused(sb) &&
17636 		    sbused(sb) &&
17637 		    !(flags & TH_SYN)) {
17638 			flags |= TH_PUSH;
17639 			add_flag |= RACK_HAD_PUSH;
17640 		}
17641 
17642 		SOCKBUF_UNLOCK(sb);
17643 	} else {
17644 		SOCKBUF_UNLOCK(sb);
17645 		if (tp->t_flags & TF_ACKNOW)
17646 			KMOD_TCPSTAT_INC(tcps_sndacks);
17647 		else if (flags & (TH_SYN | TH_FIN | TH_RST))
17648 			KMOD_TCPSTAT_INC(tcps_sndctrl);
17649 		else
17650 			KMOD_TCPSTAT_INC(tcps_sndwinup);
17651 
17652 		m = m_gethdr(M_NOWAIT, MT_DATA);
17653 		if (m == NULL) {
17654 			error = ENOBUFS;
17655 			sack_rxmit = 0;
17656 			goto out;
17657 		}
17658 #ifdef INET6
17659 		if (isipv6 && (MHLEN < hdrlen + max_linkhdr) &&
17660 		    MHLEN >= hdrlen) {
17661 			M_ALIGN(m, hdrlen);
17662 		} else
17663 #endif
17664 			m->m_data += max_linkhdr;
17665 		m->m_len = hdrlen;
17666 	}
17667 	SOCKBUF_UNLOCK_ASSERT(sb);
17668 	m->m_pkthdr.rcvif = (struct ifnet *)0;
17669 #ifdef MAC
17670 	mac_inpcb_create_mbuf(inp, m);
17671 #endif
17672 	if ((ipoptlen == 0) && (rack->r_ctl.fsb.tcp_ip_hdr) &&  rack->r_fsb_inited) {
17673 #ifdef INET6
17674 		if (isipv6)
17675 			ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
17676 		else
17677 #endif				/* INET6 */
17678 			ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
17679 		th = rack->r_ctl.fsb.th;
17680 		udp = rack->r_ctl.fsb.udp;
17681 		if (udp) {
17682 #ifdef INET6
17683 			if (isipv6)
17684 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
17685 			else
17686 #endif				/* INET6 */
17687 				ulen = hdrlen + len - sizeof(struct ip);
17688 			udp->uh_ulen = htons(ulen);
17689 		}
17690 	} else {
17691 #ifdef INET6
17692 		if (isipv6) {
17693 			ip6 = mtod(m, struct ip6_hdr *);
17694 			if (tp->t_port) {
17695 				udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
17696 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
17697 				udp->uh_dport = tp->t_port;
17698 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
17699 				udp->uh_ulen = htons(ulen);
17700 				th = (struct tcphdr *)(udp + 1);
17701 			} else
17702 				th = (struct tcphdr *)(ip6 + 1);
17703 			tcpip_fillheaders(inp, tp->t_port, ip6, th);
17704 		} else
17705 #endif				/* INET6 */
17706 		{
17707 			ip = mtod(m, struct ip *);
17708 #ifdef TCPDEBUG
17709 			ipov = (struct ipovly *)ip;
17710 #endif
17711 			if (tp->t_port) {
17712 				udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
17713 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
17714 				udp->uh_dport = tp->t_port;
17715 				ulen = hdrlen + len - sizeof(struct ip);
17716 				udp->uh_ulen = htons(ulen);
17717 				th = (struct tcphdr *)(udp + 1);
17718 			} else
17719 				th = (struct tcphdr *)(ip + 1);
17720 			tcpip_fillheaders(inp, tp->t_port, ip, th);
17721 		}
17722 	}
17723 	/*
17724 	 * Fill in fields, remembering maximum advertised window for use in
17725 	 * delaying messages about window sizes. If resending a FIN, be sure
17726 	 * not to use a new sequence number.
17727 	 */
17728 	if (flags & TH_FIN && tp->t_flags & TF_SENTFIN &&
17729 	    tp->snd_nxt == tp->snd_max)
17730 		tp->snd_nxt--;
17731 	/*
17732 	 * If we are starting a connection, send ECN setup SYN packet. If we
17733 	 * are on a retransmit, we may resend those bits a number of times
17734 	 * as per RFC 3168.
17735 	 */
17736 	if (tp->t_state == TCPS_SYN_SENT && V_tcp_do_ecn == 1) {
17737 		if (tp->t_rxtshift >= 1) {
17738 			if (tp->t_rxtshift <= V_tcp_ecn_maxretries)
17739 				flags |= TH_ECE | TH_CWR;
17740 		} else
17741 			flags |= TH_ECE | TH_CWR;
17742 	}
17743 	/* Handle parallel SYN for ECN */
17744 	if ((tp->t_state == TCPS_SYN_RECEIVED) &&
17745 	    (tp->t_flags2 & TF2_ECN_SND_ECE)) {
17746 		flags |= TH_ECE;
17747 		tp->t_flags2 &= ~TF2_ECN_SND_ECE;
17748 	}
17749 	if (TCPS_HAVEESTABLISHED(tp->t_state) &&
17750 	    (tp->t_flags2 & TF2_ECN_PERMIT)) {
17751 		/*
17752 		 * If the peer has ECN, mark data packets with ECN capable
17753 		 * transmission (ECT). Ignore pure ack packets,
17754 		 * retransmissions.
17755 		 */
17756 		if (len > 0 && SEQ_GEQ(tp->snd_nxt, tp->snd_max) &&
17757 		    (sack_rxmit == 0)) {
17758 #ifdef INET6
17759 			if (isipv6)
17760 				ip6->ip6_flow |= htonl(IPTOS_ECN_ECT0 << 20);
17761 			else
17762 #endif
17763 				ip->ip_tos |= IPTOS_ECN_ECT0;
17764 			KMOD_TCPSTAT_INC(tcps_ecn_ect0);
17765 			/*
17766 			 * Reply with proper ECN notifications.
17767 			 * Only set CWR on new data segments.
17768 			 */
17769 			if (tp->t_flags2 & TF2_ECN_SND_CWR) {
17770 				flags |= TH_CWR;
17771 				tp->t_flags2 &= ~TF2_ECN_SND_CWR;
17772 			}
17773 		}
17774 		if (tp->t_flags2 & TF2_ECN_SND_ECE)
17775 			flags |= TH_ECE;
17776 	}
17777 	/*
17778 	 * If we are doing retransmissions, then snd_nxt will not reflect
17779 	 * the first unsent octet.  For ACK only packets, we do not want the
17780 	 * sequence number of the retransmitted packet, we want the sequence
17781 	 * number of the next unsent octet.  So, if there is no data (and no
17782 	 * SYN or FIN), use snd_max instead of snd_nxt when filling in
17783 	 * ti_seq.  But if we are in persist state, snd_max might reflect
17784 	 * one byte beyond the right edge of the window, so use snd_nxt in
17785 	 * that case, since we know we aren't doing a retransmission.
17786 	 * (retransmit and persist are mutually exclusive...)
17787 	 */
17788 	if (sack_rxmit == 0) {
17789 		if (len || (flags & (TH_SYN | TH_FIN))) {
17790 			th->th_seq = htonl(tp->snd_nxt);
17791 			rack_seq = tp->snd_nxt;
17792 		} else {
17793 			th->th_seq = htonl(tp->snd_max);
17794 			rack_seq = tp->snd_max;
17795 		}
17796 	} else {
17797 		th->th_seq = htonl(rsm->r_start);
17798 		rack_seq = rsm->r_start;
17799 	}
17800 	th->th_ack = htonl(tp->rcv_nxt);
17801 	th->th_flags = flags;
17802 	/*
17803 	 * Calculate receive window.  Don't shrink window, but avoid silly
17804 	 * window syndrome.
17805 	 * If a RST segment is sent, advertise a window of zero.
17806 	 */
17807 	if (flags & TH_RST) {
17808 		recwin = 0;
17809 	} else {
17810 		if (recwin < (long)(so->so_rcv.sb_hiwat / 4) &&
17811 		    recwin < (long)segsiz) {
17812 			recwin = 0;
17813 		}
17814 		if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) &&
17815 		    recwin < (long)(tp->rcv_adv - tp->rcv_nxt))
17816 			recwin = (long)(tp->rcv_adv - tp->rcv_nxt);
17817 	}
17818 
17819 	/*
17820 	 * According to RFC1323 the window field in a SYN (i.e., a <SYN> or
17821 	 * <SYN,ACK>) segment itself is never scaled.  The <SYN,ACK> case is
17822 	 * handled in syncache.
17823 	 */
17824 	if (flags & TH_SYN)
17825 		th->th_win = htons((u_short)
17826 				   (min(sbspace(&so->so_rcv), TCP_MAXWIN)));
17827 	else {
17828 		/* Avoid shrinking window with window scaling. */
17829 		recwin = roundup2(recwin, 1 << tp->rcv_scale);
17830 		th->th_win = htons((u_short)(recwin >> tp->rcv_scale));
17831 	}
17832 	/*
17833 	 * Adjust the RXWIN0SENT flag - indicate that we have advertised a 0
17834 	 * window.  This may cause the remote transmitter to stall.  This
17835 	 * flag tells soreceive() to disable delayed acknowledgements when
17836 	 * draining the buffer.  This can occur if the receiver is
17837 	 * attempting to read more data than can be buffered prior to
17838 	 * transmitting on the connection.
17839 	 */
17840 	if (th->th_win == 0) {
17841 		tp->t_sndzerowin++;
17842 		tp->t_flags |= TF_RXWIN0SENT;
17843 	} else
17844 		tp->t_flags &= ~TF_RXWIN0SENT;
17845 	tp->snd_up = tp->snd_una;	/* drag it along, its deprecated */
17846 	/* Now are we using fsb?, if so copy the template data to the mbuf */
17847 	if ((ipoptlen == 0) && (rack->r_ctl.fsb.tcp_ip_hdr) && rack->r_fsb_inited) {
17848 		uint8_t *cpto;
17849 
17850 		cpto = mtod(m, uint8_t *);
17851 		memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
17852 		/*
17853 		 * We have just copied in:
17854 		 * IP/IP6
17855 		 * <optional udphdr>
17856 		 * tcphdr (no options)
17857 		 *
17858 		 * We need to grab the correct pointers into the mbuf
17859 		 * for both the tcp header, and possibly the udp header (if tunneling).
17860 		 * We do this by using the offset in the copy buffer and adding it
17861 		 * to the mbuf base pointer (cpto).
17862 		 */
17863 #ifdef INET6
17864 		if (isipv6)
17865 			ip6 = mtod(m, struct ip6_hdr *);
17866 		else
17867 #endif				/* INET6 */
17868 			ip = mtod(m, struct ip *);
17869 		th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
17870 		/* If we have a udp header lets set it into the mbuf as well */
17871 		if (udp)
17872 			udp = (struct udphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.udp - rack->r_ctl.fsb.tcp_ip_hdr));
17873 	}
17874 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
17875 	if (to.to_flags & TOF_SIGNATURE) {
17876 		/*
17877 		 * Calculate MD5 signature and put it into the place
17878 		 * determined before.
17879 		 * NOTE: since TCP options buffer doesn't point into
17880 		 * mbuf's data, calculate offset and use it.
17881 		 */
17882 		if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
17883 						       (u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
17884 			/*
17885 			 * Do not send segment if the calculation of MD5
17886 			 * digest has failed.
17887 			 */
17888 			goto out;
17889 		}
17890 	}
17891 #endif
17892 	if (optlen) {
17893 		bcopy(opt, th + 1, optlen);
17894 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
17895 	}
17896 	/*
17897 	 * Put TCP length in extended header, and then checksum extended
17898 	 * header and data.
17899 	 */
17900 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
17901 #ifdef INET6
17902 	if (isipv6) {
17903 		/*
17904 		 * ip6_plen is not need to be filled now, and will be filled
17905 		 * in ip6_output.
17906 		 */
17907 		if (tp->t_port) {
17908 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
17909 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
17910 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
17911 			th->th_sum = htons(0);
17912 			UDPSTAT_INC(udps_opackets);
17913 		} else {
17914 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
17915 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
17916 			th->th_sum = in6_cksum_pseudo(ip6,
17917 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
17918 						      0);
17919 		}
17920 	}
17921 #endif
17922 #if defined(INET6) && defined(INET)
17923 	else
17924 #endif
17925 #ifdef INET
17926 	{
17927 		if (tp->t_port) {
17928 			m->m_pkthdr.csum_flags = CSUM_UDP;
17929 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
17930 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
17931 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
17932 			th->th_sum = htons(0);
17933 			UDPSTAT_INC(udps_opackets);
17934 		} else {
17935 			m->m_pkthdr.csum_flags = CSUM_TCP;
17936 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
17937 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
17938 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
17939 									IPPROTO_TCP + len + optlen));
17940 		}
17941 		/* IP version must be set here for ipv4/ipv6 checking later */
17942 		KASSERT(ip->ip_v == IPVERSION,
17943 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
17944 	}
17945 #endif
17946 	/*
17947 	 * Enable TSO and specify the size of the segments. The TCP pseudo
17948 	 * header checksum is always provided. XXX: Fixme: This is currently
17949 	 * not the case for IPv6.
17950 	 */
17951 	if (tso) {
17952 		KASSERT(len > tp->t_maxseg - optlen,
17953 			("%s: len <= tso_segsz", __func__));
17954 		m->m_pkthdr.csum_flags |= CSUM_TSO;
17955 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
17956 	}
17957 	KASSERT(len + hdrlen == m_length(m, NULL),
17958 		("%s: mbuf chain different than expected: %d + %u != %u",
17959 		 __func__, len, hdrlen, m_length(m, NULL)));
17960 
17961 #ifdef TCP_HHOOK
17962 	/* Run HHOOK_TCP_ESTABLISHED_OUT helper hooks. */
17963 	hhook_run_tcp_est_out(tp, th, &to, len, tso);
17964 #endif
17965 	/* We're getting ready to send; log now. */
17966 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
17967 		union tcp_log_stackspecific log;
17968 
17969 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
17970 		log.u_bbr.inhpts = rack->rc_inp->inp_in_hpts;
17971 		log.u_bbr.ininput = rack->rc_inp->inp_in_input;
17972 		if (rack->rack_no_prr)
17973 			log.u_bbr.flex1 = 0;
17974 		else
17975 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
17976 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
17977 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
17978 		log.u_bbr.flex4 = orig_len;
17979 		if (filled_all)
17980 			log.u_bbr.flex5 = 0x80000000;
17981 		else
17982 			log.u_bbr.flex5 = 0;
17983 		/* Save off the early/late values */
17984 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
17985 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
17986 		log.u_bbr.bw_inuse = rack_get_bw(rack);
17987 		if (rsm || sack_rxmit) {
17988 			if (doing_tlp)
17989 				log.u_bbr.flex8 = 2;
17990 			else
17991 				log.u_bbr.flex8 = 1;
17992 		} else {
17993 			log.u_bbr.flex8 = 0;
17994 		}
17995 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
17996 		log.u_bbr.flex7 = mark;
17997 		log.u_bbr.flex7 <<= 8;
17998 		log.u_bbr.flex7 |= pass;
17999 		log.u_bbr.pkts_out = tp->t_maxseg;
18000 		log.u_bbr.timeStamp = cts;
18001 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
18002 		log.u_bbr.lt_epoch = cwnd_to_use;
18003 		log.u_bbr.delivered = sendalot;
18004 		lgb = tcp_log_event_(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_OUT, ERRNO_UNK,
18005 				     len, &log, false, NULL, NULL, 0, &tv);
18006 	} else
18007 		lgb = NULL;
18008 
18009 	/*
18010 	 * Fill in IP length and desired time to live and send to IP level.
18011 	 * There should be a better way to handle ttl and tos; we could keep
18012 	 * them in the template, but need a way to checksum without them.
18013 	 */
18014 	/*
18015 	 * m->m_pkthdr.len should have been set before cksum calcuration,
18016 	 * because in6_cksum() need it.
18017 	 */
18018 #ifdef INET6
18019 	if (isipv6) {
18020 		/*
18021 		 * we separately set hoplimit for every segment, since the
18022 		 * user might want to change the value via setsockopt. Also,
18023 		 * desired default hop limit might be changed via Neighbor
18024 		 * Discovery.
18025 		 */
18026 		rack->r_ctl.fsb.hoplimit = ip6->ip6_hlim = in6_selecthlim(inp, NULL);
18027 
18028 		/*
18029 		 * Set the packet size here for the benefit of DTrace
18030 		 * probes. ip6_output() will set it properly; it's supposed
18031 		 * to include the option header lengths as well.
18032 		 */
18033 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
18034 
18035 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
18036 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
18037 		else
18038 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
18039 
18040 		if (tp->t_state == TCPS_SYN_SENT)
18041 			TCP_PROBE5(connect__request, NULL, tp, ip6, tp, th);
18042 
18043 		TCP_PROBE5(send, NULL, tp, ip6, tp, th);
18044 		/* TODO: IPv6 IP6TOS_ECT bit on */
18045 		error = ip6_output(m,
18046 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
18047 				   inp->in6p_outputopts,
18048 #else
18049 				   NULL,
18050 #endif
18051 				   &inp->inp_route6,
18052 				   ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0),
18053 				   NULL, NULL, inp);
18054 
18055 		if (error == EMSGSIZE && inp->inp_route6.ro_nh != NULL)
18056 			mtu = inp->inp_route6.ro_nh->nh_mtu;
18057 	}
18058 #endif				/* INET6 */
18059 #if defined(INET) && defined(INET6)
18060 	else
18061 #endif
18062 #ifdef INET
18063 	{
18064 		ip->ip_len = htons(m->m_pkthdr.len);
18065 #ifdef INET6
18066 		if (inp->inp_vflag & INP_IPV6PROTO)
18067 			ip->ip_ttl = in6_selecthlim(inp, NULL);
18068 #endif				/* INET6 */
18069 		rack->r_ctl.fsb.hoplimit = ip->ip_ttl;
18070 		/*
18071 		 * If we do path MTU discovery, then we set DF on every
18072 		 * packet. This might not be the best thing to do according
18073 		 * to RFC3390 Section 2. However the tcp hostcache migitates
18074 		 * the problem so it affects only the first tcp connection
18075 		 * with a host.
18076 		 *
18077 		 * NB: Don't set DF on small MTU/MSS to have a safe
18078 		 * fallback.
18079 		 */
18080 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
18081 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
18082 			if (tp->t_port == 0 || len < V_tcp_minmss) {
18083 				ip->ip_off |= htons(IP_DF);
18084 			}
18085 		} else {
18086 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
18087 		}
18088 
18089 		if (tp->t_state == TCPS_SYN_SENT)
18090 			TCP_PROBE5(connect__request, NULL, tp, ip, tp, th);
18091 
18092 		TCP_PROBE5(send, NULL, tp, ip, tp, th);
18093 
18094 		error = ip_output(m,
18095 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
18096 				  inp->inp_options,
18097 #else
18098 				  NULL,
18099 #endif
18100 				  &inp->inp_route,
18101 				  ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0), 0,
18102 				  inp);
18103 		if (error == EMSGSIZE && inp->inp_route.ro_nh != NULL)
18104 			mtu = inp->inp_route.ro_nh->nh_mtu;
18105 	}
18106 #endif				/* INET */
18107 
18108 out:
18109 	if (lgb) {
18110 		lgb->tlb_errno = error;
18111 		lgb = NULL;
18112 	}
18113 	/*
18114 	 * In transmit state, time the transmission and arrange for the
18115 	 * retransmit.  In persist state, just set snd_max.
18116 	 */
18117 	if (error == 0) {
18118 		tcp_account_for_send(tp, len, (rsm != NULL), doing_tlp);
18119 		rack->forced_ack = 0;	/* If we send something zap the FA flag */
18120 		if (rsm && (doing_tlp == 0)) {
18121 			/* Set we retransmitted */
18122 			rack->rc_gp_saw_rec = 1;
18123 		} else {
18124 			if (cwnd_to_use > tp->snd_ssthresh) {
18125 				/* Set we sent in CA */
18126 				rack->rc_gp_saw_ca = 1;
18127 			} else {
18128 				/* Set we sent in SS */
18129 				rack->rc_gp_saw_ss = 1;
18130 			}
18131 		}
18132 		if (TCPS_HAVEESTABLISHED(tp->t_state) &&
18133 		    (tp->t_flags & TF_SACK_PERMIT) &&
18134 		    tp->rcv_numsacks > 0)
18135 			tcp_clean_dsack_blocks(tp);
18136 		tot_len_this_send += len;
18137 		if (len == 0)
18138 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_SNDACK], 1);
18139 		else if (len == 1) {
18140 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_PERSIST], 1);
18141 		} else if (len > 1) {
18142 			int idx;
18143 
18144 			idx = (len / segsiz) + 3;
18145 			if (idx >= TCP_MSS_ACCT_ATIMER)
18146 				counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
18147 			else
18148 				counter_u64_add(rack_out_size[idx], 1);
18149 		}
18150 	}
18151 	if ((rack->rack_no_prr == 0) &&
18152 	    sub_from_prr &&
18153 	    (error == 0)) {
18154 		if (rack->r_ctl.rc_prr_sndcnt >= len)
18155 			rack->r_ctl.rc_prr_sndcnt -= len;
18156 		else
18157 			rack->r_ctl.rc_prr_sndcnt = 0;
18158 	}
18159 	sub_from_prr = 0;
18160 	if (doing_tlp && (rsm == NULL)) {
18161 		/* New send doing a TLP */
18162 		add_flag |= RACK_TLP;
18163 	}
18164 	rack_log_output(tp, &to, len, rack_seq, (uint8_t) flags, error,
18165 			rack_to_usec_ts(&tv),
18166 			rsm, add_flag, s_mb, s_moff);
18167 
18168 
18169 	if ((error == 0) &&
18170 	    (len > 0) &&
18171 	    (tp->snd_una == tp->snd_max))
18172 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
18173 	{
18174 		tcp_seq startseq = tp->snd_nxt;
18175 
18176 		/* Track our lost count */
18177 		if (rsm && (doing_tlp == 0))
18178 			rack->r_ctl.rc_loss_count += rsm->r_end - rsm->r_start;
18179 		/*
18180 		 * Advance snd_nxt over sequence space of this segment.
18181 		 */
18182 		if (error)
18183 			/* We don't log or do anything with errors */
18184 			goto nomore;
18185 		if (doing_tlp == 0) {
18186 			if (rsm == NULL) {
18187 				/*
18188 				 * Not a retransmission of some
18189 				 * sort, new data is going out so
18190 				 * clear our TLP count and flag.
18191 				 */
18192 				rack->rc_tlp_in_progress = 0;
18193 				rack->r_ctl.rc_tlp_cnt_out = 0;
18194 			}
18195 		} else {
18196 			/*
18197 			 * We have just sent a TLP, mark that it is true
18198 			 * and make sure our in progress is set so we
18199 			 * continue to check the count.
18200 			 */
18201 			rack->rc_tlp_in_progress = 1;
18202 			rack->r_ctl.rc_tlp_cnt_out++;
18203 		}
18204 		if (flags & (TH_SYN | TH_FIN)) {
18205 			if (flags & TH_SYN)
18206 				tp->snd_nxt++;
18207 			if (flags & TH_FIN) {
18208 				tp->snd_nxt++;
18209 				tp->t_flags |= TF_SENTFIN;
18210 			}
18211 		}
18212 		/* In the ENOBUFS case we do *not* update snd_max */
18213 		if (sack_rxmit)
18214 			goto nomore;
18215 
18216 		tp->snd_nxt += len;
18217 		if (SEQ_GT(tp->snd_nxt, tp->snd_max)) {
18218 			if (tp->snd_una == tp->snd_max) {
18219 				/*
18220 				 * Update the time we just added data since
18221 				 * none was outstanding.
18222 				 */
18223 				rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
18224 				tp->t_acktime = ticks;
18225 			}
18226 			tp->snd_max = tp->snd_nxt;
18227 			/*
18228 			 * Time this transmission if not a retransmission and
18229 			 * not currently timing anything.
18230 			 * This is only relevant in case of switching back to
18231 			 * the base stack.
18232 			 */
18233 			if (tp->t_rtttime == 0) {
18234 				tp->t_rtttime = ticks;
18235 				tp->t_rtseq = startseq;
18236 				KMOD_TCPSTAT_INC(tcps_segstimed);
18237 			}
18238 			if (len &&
18239 			    ((tp->t_flags & TF_GPUTINPROG) == 0))
18240 				rack_start_gp_measurement(tp, rack, startseq, sb_offset);
18241 		}
18242 		/*
18243 		 * If we are doing FO we need to update the mbuf position and subtract
18244 		 * this happens when the peer sends us duplicate information and
18245 		 * we thus want to send a DSACK.
18246 		 *
18247 		 * XXXRRS: This brings to mind a ?, when we send a DSACK block is TSO
18248 		 * turned off? If not then we are going to echo multiple DSACK blocks
18249 		 * out (with the TSO), which we should not be doing.
18250 		 */
18251 		if (rack->r_fast_output && len) {
18252 			if (rack->r_ctl.fsb.left_to_send > len)
18253 				rack->r_ctl.fsb.left_to_send -= len;
18254 			else
18255 				rack->r_ctl.fsb.left_to_send = 0;
18256 			if (rack->r_ctl.fsb.left_to_send < segsiz)
18257 				rack->r_fast_output = 0;
18258 			if (rack->r_fast_output) {
18259 				rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
18260 				rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
18261 			}
18262 		}
18263 	}
18264 nomore:
18265 	if (error) {
18266 		rack->r_ctl.rc_agg_delayed = 0;
18267 		rack->r_early = 0;
18268 		rack->r_late = 0;
18269 		rack->r_ctl.rc_agg_early = 0;
18270 		SOCKBUF_UNLOCK_ASSERT(sb);	/* Check gotos. */
18271 		/*
18272 		 * Failures do not advance the seq counter above. For the
18273 		 * case of ENOBUFS we will fall out and retry in 1ms with
18274 		 * the hpts. Everything else will just have to retransmit
18275 		 * with the timer.
18276 		 *
18277 		 * In any case, we do not want to loop around for another
18278 		 * send without a good reason.
18279 		 */
18280 		sendalot = 0;
18281 		switch (error) {
18282 		case EPERM:
18283 			tp->t_softerror = error;
18284 #ifdef TCP_ACCOUNTING
18285 			crtsc = get_cyclecount();
18286 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18287 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
18288 			}
18289 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
18290 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18291 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
18292 			}
18293 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
18294 			sched_unpin();
18295 #endif
18296 			return (error);
18297 		case ENOBUFS:
18298 			/*
18299 			 * Pace us right away to retry in a some
18300 			 * time
18301 			 */
18302 			slot = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
18303 			if (rack->rc_enobuf < 0x7f)
18304 				rack->rc_enobuf++;
18305 			if (slot < (10 * HPTS_USEC_IN_MSEC))
18306 				slot = 10 * HPTS_USEC_IN_MSEC;
18307 			if (rack->r_ctl.crte != NULL) {
18308 				counter_u64_add(rack_saw_enobuf_hw, 1);
18309 				tcp_rl_log_enobuf(rack->r_ctl.crte);
18310 			}
18311 			counter_u64_add(rack_saw_enobuf, 1);
18312 			goto enobufs;
18313 		case EMSGSIZE:
18314 			/*
18315 			 * For some reason the interface we used initially
18316 			 * to send segments changed to another or lowered
18317 			 * its MTU. If TSO was active we either got an
18318 			 * interface without TSO capabilits or TSO was
18319 			 * turned off. If we obtained mtu from ip_output()
18320 			 * then update it and try again.
18321 			 */
18322 			if (tso)
18323 				tp->t_flags &= ~TF_TSO;
18324 			if (mtu != 0) {
18325 				tcp_mss_update(tp, -1, mtu, NULL, NULL);
18326 				goto again;
18327 			}
18328 			slot = 10 * HPTS_USEC_IN_MSEC;
18329 			rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
18330 #ifdef TCP_ACCOUNTING
18331 			crtsc = get_cyclecount();
18332 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18333 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
18334 			}
18335 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
18336 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18337 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
18338 			}
18339 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
18340 			sched_unpin();
18341 #endif
18342 			return (error);
18343 		case ENETUNREACH:
18344 			counter_u64_add(rack_saw_enetunreach, 1);
18345 		case EHOSTDOWN:
18346 		case EHOSTUNREACH:
18347 		case ENETDOWN:
18348 			if (TCPS_HAVERCVDSYN(tp->t_state)) {
18349 				tp->t_softerror = error;
18350 			}
18351 			/* FALLTHROUGH */
18352 		default:
18353 			slot = 10 * HPTS_USEC_IN_MSEC;
18354 			rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
18355 #ifdef TCP_ACCOUNTING
18356 			crtsc = get_cyclecount();
18357 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18358 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
18359 			}
18360 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
18361 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18362 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
18363 			}
18364 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
18365 			sched_unpin();
18366 #endif
18367 			return (error);
18368 		}
18369 	} else {
18370 		rack->rc_enobuf = 0;
18371 		if (IN_FASTRECOVERY(tp->t_flags) && rsm)
18372 			rack->r_ctl.retran_during_recovery += len;
18373 	}
18374 	KMOD_TCPSTAT_INC(tcps_sndtotal);
18375 
18376 	/*
18377 	 * Data sent (as far as we can tell). If this advertises a larger
18378 	 * window than any other segment, then remember the size of the
18379 	 * advertised window. Any pending ACK has now been sent.
18380 	 */
18381 	if (recwin > 0 && SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv))
18382 		tp->rcv_adv = tp->rcv_nxt + recwin;
18383 
18384 	tp->last_ack_sent = tp->rcv_nxt;
18385 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
18386 enobufs:
18387 	if (sendalot) {
18388 		/* Do we need to turn off sendalot? */
18389 		if (rack->r_ctl.rc_pace_max_segs &&
18390 		    (tot_len_this_send >= rack->r_ctl.rc_pace_max_segs)) {
18391 			/* We hit our max. */
18392 			sendalot = 0;
18393 		} else if ((rack->rc_user_set_max_segs) &&
18394 			   (tot_len_this_send >= (rack->rc_user_set_max_segs * segsiz))) {
18395 			/* We hit the user defined max */
18396 			sendalot = 0;
18397 		}
18398 	}
18399 	if ((error == 0) && (flags & TH_FIN))
18400 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_FIN);
18401 	if (flags & TH_RST) {
18402 		/*
18403 		 * We don't send again after sending a RST.
18404 		 */
18405 		slot = 0;
18406 		sendalot = 0;
18407 		if (error == 0)
18408 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
18409 	} else if ((slot == 0) && (sendalot == 0) && tot_len_this_send) {
18410 		/*
18411 		 * Get our pacing rate, if an error
18412 		 * occurred in sending (ENOBUF) we would
18413 		 * hit the else if with slot preset. Other
18414 		 * errors return.
18415 		 */
18416 		slot = rack_get_pacing_delay(rack, tp, tot_len_this_send, rsm, segsiz);
18417 	}
18418 	if (rsm &&
18419 	    (rsm->r_flags & RACK_HAS_SYN) == 0 &&
18420 	    rack->use_rack_rr) {
18421 		/* Its a retransmit and we use the rack cheat? */
18422 		if ((slot == 0) ||
18423 		    (rack->rc_always_pace == 0) ||
18424 		    (rack->r_rr_config == 1)) {
18425 			/*
18426 			 * We have no pacing set or we
18427 			 * are using old-style rack or
18428 			 * we are overriden to use the old 1ms pacing.
18429 			 */
18430 			slot = rack->r_ctl.rc_min_to;
18431 		}
18432 	}
18433 	/* We have sent clear the flag */
18434 	rack->r_ent_rec_ns = 0;
18435 	if (rack->r_must_retran) {
18436 		if (rsm) {
18437 			rack->r_ctl.rc_out_at_rto -= (rsm->r_end - rsm->r_start);
18438 			if (SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) {
18439 				/*
18440 				 * We have retransmitted all.
18441 				 */
18442 				rack->r_must_retran = 0;
18443 				rack->r_ctl.rc_out_at_rto = 0;
18444 			}
18445 		} else if (SEQ_GEQ(tp->snd_max, rack->r_ctl.rc_snd_max_at_rto)) {
18446 			/*
18447 			 * Sending new data will also kill
18448 			 * the loop.
18449 			 */
18450 			rack->r_must_retran = 0;
18451 			rack->r_ctl.rc_out_at_rto = 0;
18452 		}
18453 	}
18454 	rack->r_ctl.fsb.recwin = recwin;
18455 	if ((tp->t_flags & (TF_WASCRECOVERY|TF_WASFRECOVERY)) &&
18456 	    SEQ_GT(tp->snd_max, rack->r_ctl.rc_snd_max_at_rto)) {
18457 		/*
18458 		 * We hit an RTO and now have past snd_max at the RTO
18459 		 * clear all the WAS flags.
18460 		 */
18461 		tp->t_flags &= ~(TF_WASCRECOVERY|TF_WASFRECOVERY);
18462 	}
18463 	if (slot) {
18464 		/* set the rack tcb into the slot N */
18465 		counter_u64_add(rack_paced_segments, 1);
18466 		if ((error == 0) &&
18467 		    rack_use_rfo &&
18468 		    ((flags & (TH_SYN|TH_FIN)) == 0) &&
18469 		    (rsm == NULL) &&
18470 		    (tp->snd_nxt == tp->snd_max) &&
18471 		    (ipoptlen == 0) &&
18472 		    (tp->rcv_numsacks == 0) &&
18473 		    rack->r_fsb_inited &&
18474 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
18475 		    (rack->r_must_retran == 0) &&
18476 		    ((tp->t_flags & TF_NEEDFIN) == 0) &&
18477 		    (len > 0) && (orig_len > 0) &&
18478 		    (orig_len > len) &&
18479 		    ((orig_len - len) >= segsiz) &&
18480 		    ((optlen == 0) ||
18481 		     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
18482 			/* We can send at least one more MSS using our fsb */
18483 
18484 			rack->r_fast_output = 1;
18485 			rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
18486 			rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
18487 			rack->r_ctl.fsb.tcp_flags = flags;
18488 			rack->r_ctl.fsb.left_to_send = orig_len - len;
18489 			KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
18490 				("rack:%p left_to_send:%u sbavail:%u out:%u",
18491 				 rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
18492 				 (tp->snd_max - tp->snd_una)));
18493 			if (rack->r_ctl.fsb.left_to_send < segsiz)
18494 				rack->r_fast_output = 0;
18495 			else {
18496 				if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
18497 					rack->r_ctl.fsb.rfo_apply_push = 1;
18498 				else
18499 					rack->r_ctl.fsb.rfo_apply_push = 0;
18500 			}
18501 		} else
18502 			rack->r_fast_output = 0;
18503 		rack_log_fsb(rack, tp, so, flags,
18504 			     ipoptlen, orig_len, len, error,
18505 			     (rsm == NULL), optlen, __LINE__, 2);
18506 	} else if (sendalot) {
18507 		int ret;
18508 
18509 		if (len)
18510 			counter_u64_add(rack_unpaced_segments, 1);
18511 		sack_rxmit = 0;
18512 		if ((error == 0) &&
18513 		    rack_use_rfo &&
18514 		    ((flags & (TH_SYN|TH_FIN)) == 0) &&
18515 		    (rsm == NULL) &&
18516 		    (ipoptlen == 0) &&
18517 		    (tp->rcv_numsacks == 0) &&
18518 		    (tp->snd_nxt == tp->snd_max) &&
18519 		    (rack->r_must_retran == 0) &&
18520 		    rack->r_fsb_inited &&
18521 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
18522 		    ((tp->t_flags & TF_NEEDFIN) == 0) &&
18523 		    (len > 0) && (orig_len > 0) &&
18524 		    (orig_len > len) &&
18525 		    ((orig_len - len) >= segsiz) &&
18526 		    ((optlen == 0) ||
18527 		     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
18528 			/* we can use fast_output for more */
18529 
18530 			rack->r_fast_output = 1;
18531 			rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
18532 			rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
18533 			rack->r_ctl.fsb.tcp_flags = flags;
18534 			rack->r_ctl.fsb.left_to_send = orig_len - len;
18535 			KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
18536 				("rack:%p left_to_send:%u sbavail:%u out:%u",
18537 				 rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
18538 				 (tp->snd_max - tp->snd_una)));
18539 			if (rack->r_ctl.fsb.left_to_send < segsiz) {
18540 				rack->r_fast_output = 0;
18541 			}
18542 			if (rack->r_fast_output) {
18543 				if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
18544 					rack->r_ctl.fsb.rfo_apply_push = 1;
18545 				else
18546 					rack->r_ctl.fsb.rfo_apply_push = 0;
18547 				rack_log_fsb(rack, tp, so, flags,
18548 					     ipoptlen, orig_len, len, error,
18549 					     (rsm == NULL), optlen, __LINE__, 3);
18550 				error = 0;
18551 				ret = rack_fast_output(tp, rack, ts_val, cts, ms_cts, &tv, tot_len_this_send, &error);
18552 				if (ret >= 0)
18553 					return (ret);
18554 			        else if (error)
18555 					goto nomore;
18556 
18557 			}
18558 		}
18559 		goto again;
18560 	} else if (len) {
18561 		counter_u64_add(rack_unpaced_segments, 1);
18562 	}
18563 	/* Assure when we leave that snd_nxt will point to top */
18564 	if (SEQ_GT(tp->snd_max, tp->snd_nxt))
18565 		tp->snd_nxt = tp->snd_max;
18566 	rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, 0);
18567 #ifdef TCP_ACCOUNTING
18568 	crtsc = get_cyclecount() - ts_val;
18569 	if (tot_len_this_send) {
18570 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18571 			tp->tcp_cnt_counters[SND_OUT_DATA]++;
18572 		}
18573 		counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], 1);
18574 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18575 			tp->tcp_proc_time[SND_OUT_DATA] += crtsc;
18576 		}
18577 		counter_u64_add(tcp_proc_time[SND_OUT_DATA], crtsc);
18578 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18579 			tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len_this_send + segsiz - 1) /segsiz);
18580 		}
18581 		counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((tot_len_this_send + segsiz - 1) /segsiz));
18582 	} else {
18583 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18584 			tp->tcp_cnt_counters[SND_OUT_ACK]++;
18585 		}
18586 		counter_u64_add(tcp_cnt_counters[SND_OUT_ACK], 1);
18587 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18588 			tp->tcp_proc_time[SND_OUT_ACK] += crtsc;
18589 		}
18590 		counter_u64_add(tcp_proc_time[SND_OUT_ACK], crtsc);
18591 	}
18592 	sched_unpin();
18593 #endif
18594 	if (error == ENOBUFS)
18595 		error = 0;
18596 	return (error);
18597 }
18598 
18599 static void
18600 rack_update_seg(struct tcp_rack *rack)
18601 {
18602 	uint32_t orig_val;
18603 
18604 	orig_val = rack->r_ctl.rc_pace_max_segs;
18605 	rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
18606 	if (orig_val != rack->r_ctl.rc_pace_max_segs)
18607 		rack_log_pacing_delay_calc(rack, 0, 0, orig_val, 0, 0, 15, __LINE__, NULL);
18608 }
18609 
18610 static void
18611 rack_mtu_change(struct tcpcb *tp)
18612 {
18613 	/*
18614 	 * The MSS may have changed
18615 	 */
18616 	struct tcp_rack *rack;
18617 
18618 	rack = (struct tcp_rack *)tp->t_fb_ptr;
18619 	if (rack->r_ctl.rc_pace_min_segs != ctf_fixed_maxseg(tp)) {
18620 		/*
18621 		 * The MTU has changed we need to resend everything
18622 		 * since all we have sent is lost. We first fix
18623 		 * up the mtu though.
18624 		 */
18625 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
18626 		/* We treat this like a full retransmit timeout without the cwnd adjustment */
18627 		rack_remxt_tmr(tp);
18628 		rack->r_fast_output = 0;
18629 		rack->r_ctl.rc_out_at_rto = ctf_flight_size(tp,
18630 						rack->r_ctl.rc_sacked);
18631 		rack->r_ctl.rc_snd_max_at_rto = tp->snd_max;
18632 		rack->r_must_retran = 1;
18633 
18634 	}
18635 	sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
18636 	/* We don't use snd_nxt to retransmit */
18637 	tp->snd_nxt = tp->snd_max;
18638 }
18639 
18640 static int
18641 rack_set_profile(struct tcp_rack *rack, int prof)
18642 {
18643 	int err = EINVAL;
18644 	if (prof == 1) {
18645 		/* pace_always=1 */
18646 		if (rack->rc_always_pace == 0) {
18647 			if (tcp_can_enable_pacing() == 0)
18648 				return (EBUSY);
18649 		}
18650 		rack->rc_always_pace = 1;
18651 		if (rack->use_fixed_rate || rack->gp_ready)
18652 			rack_set_cc_pacing(rack);
18653 		rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
18654 		rack->rack_attempt_hdwr_pace = 0;
18655 		/* cmpack=1 */
18656 		if (rack_use_cmp_acks)
18657 			rack->r_use_cmp_ack = 1;
18658 		if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state) &&
18659 		    rack->r_use_cmp_ack)
18660 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
18661 		/* scwnd=1 */
18662 		rack->rack_enable_scwnd = 1;
18663 		/* dynamic=100 */
18664 		rack->rc_gp_dyn_mul = 1;
18665 		/* gp_inc_ca */
18666 		rack->r_ctl.rack_per_of_gp_ca = 100;
18667 		/* rrr_conf=3 */
18668 		rack->r_rr_config = 3;
18669 		/* npush=2 */
18670 		rack->r_ctl.rc_no_push_at_mrtt = 2;
18671 		/* fillcw=1 */
18672 		rack->rc_pace_to_cwnd = 1;
18673 		rack->rc_pace_fill_if_rttin_range = 0;
18674 		rack->rtt_limit_mul = 0;
18675 		/* noprr=1 */
18676 		rack->rack_no_prr = 1;
18677 		/* lscwnd=1 */
18678 		rack->r_limit_scw = 1;
18679 		/* gp_inc_rec */
18680 		rack->r_ctl.rack_per_of_gp_rec = 90;
18681 		err = 0;
18682 
18683 	} else if (prof == 3) {
18684 		/* Same as profile one execept fill_cw becomes 2 (less aggressive set) */
18685 		/* pace_always=1 */
18686 		if (rack->rc_always_pace == 0) {
18687 			if (tcp_can_enable_pacing() == 0)
18688 				return (EBUSY);
18689 		}
18690 		rack->rc_always_pace = 1;
18691 		if (rack->use_fixed_rate || rack->gp_ready)
18692 			rack_set_cc_pacing(rack);
18693 		rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
18694 		rack->rack_attempt_hdwr_pace = 0;
18695 		/* cmpack=1 */
18696 		if (rack_use_cmp_acks)
18697 			rack->r_use_cmp_ack = 1;
18698 		if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state) &&
18699 		    rack->r_use_cmp_ack)
18700 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
18701 		/* scwnd=1 */
18702 		rack->rack_enable_scwnd = 1;
18703 		/* dynamic=100 */
18704 		rack->rc_gp_dyn_mul = 1;
18705 		/* gp_inc_ca */
18706 		rack->r_ctl.rack_per_of_gp_ca = 100;
18707 		/* rrr_conf=3 */
18708 		rack->r_rr_config = 3;
18709 		/* npush=2 */
18710 		rack->r_ctl.rc_no_push_at_mrtt = 2;
18711 		/* fillcw=2 */
18712 		rack->rc_pace_to_cwnd = 1;
18713 		rack->r_fill_less_agg = 1;
18714 		rack->rc_pace_fill_if_rttin_range = 0;
18715 		rack->rtt_limit_mul = 0;
18716 		/* noprr=1 */
18717 		rack->rack_no_prr = 1;
18718 		/* lscwnd=1 */
18719 		rack->r_limit_scw = 1;
18720 		/* gp_inc_rec */
18721 		rack->r_ctl.rack_per_of_gp_rec = 90;
18722 		err = 0;
18723 
18724 
18725 	} else if (prof == 2) {
18726 		/* cmpack=1 */
18727 		if (rack->rc_always_pace == 0) {
18728 			if (tcp_can_enable_pacing() == 0)
18729 				return (EBUSY);
18730 		}
18731 		rack->rc_always_pace = 1;
18732 		if (rack->use_fixed_rate || rack->gp_ready)
18733 			rack_set_cc_pacing(rack);
18734 		rack->r_use_cmp_ack = 1;
18735 		if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state))
18736 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
18737 		/* pace_always=1 */
18738 		rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
18739 		/* scwnd=1 */
18740 		rack->rack_enable_scwnd = 1;
18741 		/* dynamic=100 */
18742 		rack->rc_gp_dyn_mul = 1;
18743 		rack->r_ctl.rack_per_of_gp_ca = 100;
18744 		/* rrr_conf=3 */
18745 		rack->r_rr_config = 3;
18746 		/* npush=2 */
18747 		rack->r_ctl.rc_no_push_at_mrtt = 2;
18748 		/* fillcw=1 */
18749 		rack->rc_pace_to_cwnd = 1;
18750 		rack->rc_pace_fill_if_rttin_range = 0;
18751 		rack->rtt_limit_mul = 0;
18752 		/* noprr=1 */
18753 		rack->rack_no_prr = 1;
18754 		/* lscwnd=0 */
18755 		rack->r_limit_scw = 0;
18756 		err = 0;
18757 	} else if (prof == 0) {
18758 		/* This changes things back to the default settings */
18759 		err = 0;
18760 		if (rack->rc_always_pace) {
18761 			tcp_decrement_paced_conn();
18762 			rack_undo_cc_pacing(rack);
18763 			rack->rc_always_pace = 0;
18764 		}
18765 		if (rack_pace_every_seg && tcp_can_enable_pacing()) {
18766 			rack->rc_always_pace = 1;
18767 			if (rack->use_fixed_rate || rack->gp_ready)
18768 				rack_set_cc_pacing(rack);
18769 		} else
18770 			rack->rc_always_pace = 0;
18771 		if (rack_use_cmp_acks)
18772 			rack->r_use_cmp_ack = 1;
18773 		else
18774 			rack->r_use_cmp_ack = 0;
18775 		if (rack_disable_prr)
18776 			rack->rack_no_prr = 1;
18777 		else
18778 			rack->rack_no_prr = 0;
18779 		if (rack_gp_no_rec_chg)
18780 			rack->rc_gp_no_rec_chg = 1;
18781 		else
18782 			rack->rc_gp_no_rec_chg = 0;
18783 		if (rack_enable_mqueue_for_nonpaced || rack->r_use_cmp_ack) {
18784 			rack->r_mbuf_queue = 1;
18785 			if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state))
18786 				rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
18787 			rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
18788 		} else {
18789 			rack->r_mbuf_queue = 0;
18790 			rack->rc_inp->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
18791 		}
18792 		if (rack_enable_shared_cwnd)
18793 			rack->rack_enable_scwnd = 1;
18794 		else
18795 			rack->rack_enable_scwnd = 0;
18796 		if (rack_do_dyn_mul) {
18797 			/* When dynamic adjustment is on CA needs to start at 100% */
18798 			rack->rc_gp_dyn_mul = 1;
18799 			if (rack_do_dyn_mul >= 100)
18800 				rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
18801 		} else {
18802 			rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
18803 			rack->rc_gp_dyn_mul = 0;
18804 		}
18805 		rack->r_rr_config = 0;
18806 		rack->r_ctl.rc_no_push_at_mrtt = 0;
18807 		rack->rc_pace_to_cwnd = 0;
18808 		rack->rc_pace_fill_if_rttin_range = 0;
18809 		rack->rtt_limit_mul = 0;
18810 
18811 		if (rack_enable_hw_pacing)
18812 			rack->rack_hdw_pace_ena = 1;
18813 		else
18814 			rack->rack_hdw_pace_ena = 0;
18815 		if (rack_disable_prr)
18816 			rack->rack_no_prr = 1;
18817 		else
18818 			rack->rack_no_prr = 0;
18819 		if (rack_limits_scwnd)
18820 			rack->r_limit_scw  = 1;
18821 		else
18822 			rack->r_limit_scw  = 0;
18823 		err = 0;
18824 	}
18825 	return (err);
18826 }
18827 
18828 static int
18829 rack_add_deferred_option(struct tcp_rack *rack, int sopt_name, uint64_t loptval)
18830 {
18831 	struct deferred_opt_list *dol;
18832 
18833 	dol = malloc(sizeof(struct deferred_opt_list),
18834 		     M_TCPFSB, M_NOWAIT|M_ZERO);
18835 	if (dol == NULL) {
18836 		/*
18837 		 * No space yikes -- fail out..
18838 		 */
18839 		return (0);
18840 	}
18841 	dol->optname = sopt_name;
18842 	dol->optval = loptval;
18843 	TAILQ_INSERT_TAIL(&rack->r_ctl.opt_list, dol, next);
18844 	return (1);
18845 }
18846 
18847 static int
18848 rack_process_option(struct tcpcb *tp, struct tcp_rack *rack, int sopt_name,
18849 		    uint32_t optval, uint64_t loptval)
18850 {
18851 	struct epoch_tracker et;
18852 	struct sockopt sopt;
18853 	struct cc_newreno_opts opt;
18854 	uint64_t val;
18855 	int error = 0;
18856 	uint16_t ca, ss;
18857 
18858 	switch (sopt_name) {
18859 
18860 	case TCP_RACK_PACING_BETA:
18861 		RACK_OPTS_INC(tcp_rack_beta);
18862 		if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0) {
18863 			/* This only works for newreno. */
18864 			error = EINVAL;
18865 			break;
18866 		}
18867 		if (rack->rc_pacing_cc_set) {
18868 			/*
18869 			 * Set them into the real CC module
18870 			 * whats in the rack pcb is the old values
18871 			 * to be used on restoral/
18872 			 */
18873 			sopt.sopt_dir = SOPT_SET;
18874 			opt.name = CC_NEWRENO_BETA;
18875 			opt.val = optval;
18876 			if (CC_ALGO(tp)->ctl_output != NULL)
18877 				error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
18878 			else {
18879 				error = ENOENT;
18880 				break;
18881 			}
18882 		} else {
18883 			/*
18884 			 * Not pacing yet so set it into our local
18885 			 * rack pcb storage.
18886 			 */
18887 			rack->r_ctl.rc_saved_beta.beta = optval;
18888 		}
18889 		break;
18890 	case TCP_RACK_TIMER_SLOP:
18891 		RACK_OPTS_INC(tcp_rack_timer_slop);
18892 		rack->r_ctl.timer_slop = optval;
18893 		if (rack->rc_tp->t_srtt) {
18894 			/*
18895 			 * If we have an SRTT lets update t_rxtcur
18896 			 * to have the new slop.
18897 			 */
18898 			RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
18899 					   rack_rto_min, rack_rto_max,
18900 					   rack->r_ctl.timer_slop);
18901 		}
18902 		break;
18903 	case TCP_RACK_PACING_BETA_ECN:
18904 		RACK_OPTS_INC(tcp_rack_beta_ecn);
18905 		if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0) {
18906 			/* This only works for newreno. */
18907 			error = EINVAL;
18908 			break;
18909 		}
18910 		if (rack->rc_pacing_cc_set) {
18911 			/*
18912 			 * Set them into the real CC module
18913 			 * whats in the rack pcb is the old values
18914 			 * to be used on restoral/
18915 			 */
18916 			sopt.sopt_dir = SOPT_SET;
18917 			opt.name = CC_NEWRENO_BETA_ECN;
18918 			opt.val = optval;
18919 			if (CC_ALGO(tp)->ctl_output != NULL)
18920 				error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
18921 			else
18922 				error = ENOENT;
18923 		} else {
18924 			/*
18925 			 * Not pacing yet so set it into our local
18926 			 * rack pcb storage.
18927 			 */
18928 			rack->r_ctl.rc_saved_beta.beta_ecn = optval;
18929 			rack->r_ctl.rc_saved_beta.newreno_flags = CC_NEWRENO_BETA_ECN;
18930 		}
18931 		break;
18932 	case TCP_DEFER_OPTIONS:
18933 		RACK_OPTS_INC(tcp_defer_opt);
18934 		if (optval) {
18935 			if (rack->gp_ready) {
18936 				/* Too late */
18937 				error = EINVAL;
18938 				break;
18939 			}
18940 			rack->defer_options = 1;
18941 		} else
18942 			rack->defer_options = 0;
18943 		break;
18944 	case TCP_RACK_MEASURE_CNT:
18945 		RACK_OPTS_INC(tcp_rack_measure_cnt);
18946 		if (optval && (optval <= 0xff)) {
18947 			rack->r_ctl.req_measurements = optval;
18948 		} else
18949 			error = EINVAL;
18950 		break;
18951 	case TCP_REC_ABC_VAL:
18952 		RACK_OPTS_INC(tcp_rec_abc_val);
18953 		if (optval > 0)
18954 			rack->r_use_labc_for_rec = 1;
18955 		else
18956 			rack->r_use_labc_for_rec = 0;
18957 		break;
18958 	case TCP_RACK_ABC_VAL:
18959 		RACK_OPTS_INC(tcp_rack_abc_val);
18960 		if ((optval > 0) && (optval < 255))
18961 			rack->rc_labc = optval;
18962 		else
18963 			error = EINVAL;
18964 		break;
18965 	case TCP_HDWR_UP_ONLY:
18966 		RACK_OPTS_INC(tcp_pacing_up_only);
18967 		if (optval)
18968 			rack->r_up_only = 1;
18969 		else
18970 			rack->r_up_only = 0;
18971 		break;
18972 	case TCP_PACING_RATE_CAP:
18973 		RACK_OPTS_INC(tcp_pacing_rate_cap);
18974 		rack->r_ctl.bw_rate_cap = loptval;
18975 		break;
18976 	case TCP_RACK_PROFILE:
18977 		RACK_OPTS_INC(tcp_profile);
18978 		error = rack_set_profile(rack, optval);
18979 		break;
18980 	case TCP_USE_CMP_ACKS:
18981 		RACK_OPTS_INC(tcp_use_cmp_acks);
18982 		if ((optval == 0) && (rack->rc_inp->inp_flags2 & INP_MBUF_ACKCMP)) {
18983 			/* You can't turn it off once its on! */
18984 			error = EINVAL;
18985 		} else if ((optval == 1) && (rack->r_use_cmp_ack == 0)) {
18986 			rack->r_use_cmp_ack = 1;
18987 			rack->r_mbuf_queue = 1;
18988 			tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
18989 		}
18990 		if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
18991 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
18992 		break;
18993 	case TCP_SHARED_CWND_TIME_LIMIT:
18994 		RACK_OPTS_INC(tcp_lscwnd);
18995 		if (optval)
18996 			rack->r_limit_scw = 1;
18997 		else
18998 			rack->r_limit_scw = 0;
18999 		break;
19000  	case TCP_RACK_PACE_TO_FILL:
19001 		RACK_OPTS_INC(tcp_fillcw);
19002 		if (optval == 0)
19003 			rack->rc_pace_to_cwnd = 0;
19004 		else {
19005 			rack->rc_pace_to_cwnd = 1;
19006 			if (optval > 1)
19007 				rack->r_fill_less_agg = 1;
19008 		}
19009 		if ((optval >= rack_gp_rtt_maxmul) &&
19010 		    rack_gp_rtt_maxmul &&
19011 		    (optval < 0xf)) {
19012 			rack->rc_pace_fill_if_rttin_range = 1;
19013 			rack->rtt_limit_mul = optval;
19014 		} else {
19015 			rack->rc_pace_fill_if_rttin_range = 0;
19016 			rack->rtt_limit_mul = 0;
19017 		}
19018 		break;
19019 	case TCP_RACK_NO_PUSH_AT_MAX:
19020 		RACK_OPTS_INC(tcp_npush);
19021 		if (optval == 0)
19022 			rack->r_ctl.rc_no_push_at_mrtt = 0;
19023 		else if (optval < 0xff)
19024 			rack->r_ctl.rc_no_push_at_mrtt = optval;
19025 		else
19026 			error = EINVAL;
19027 		break;
19028 	case TCP_SHARED_CWND_ENABLE:
19029 		RACK_OPTS_INC(tcp_rack_scwnd);
19030 		if (optval == 0)
19031 			rack->rack_enable_scwnd = 0;
19032 		else
19033 			rack->rack_enable_scwnd = 1;
19034 		break;
19035 	case TCP_RACK_MBUF_QUEUE:
19036 		/* Now do we use the LRO mbuf-queue feature */
19037 		RACK_OPTS_INC(tcp_rack_mbufq);
19038 		if (optval || rack->r_use_cmp_ack)
19039 			rack->r_mbuf_queue = 1;
19040 		else
19041 			rack->r_mbuf_queue = 0;
19042 		if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
19043 			tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19044 		else
19045 			tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
19046 		break;
19047 	case TCP_RACK_NONRXT_CFG_RATE:
19048 		RACK_OPTS_INC(tcp_rack_cfg_rate);
19049 		if (optval == 0)
19050 			rack->rack_rec_nonrxt_use_cr = 0;
19051 		else
19052 			rack->rack_rec_nonrxt_use_cr = 1;
19053 		break;
19054 	case TCP_NO_PRR:
19055 		RACK_OPTS_INC(tcp_rack_noprr);
19056 		if (optval == 0)
19057 			rack->rack_no_prr = 0;
19058 		else if (optval == 1)
19059 			rack->rack_no_prr = 1;
19060 		else if (optval == 2)
19061 			rack->no_prr_addback = 1;
19062 		else
19063 			error = EINVAL;
19064 		break;
19065 	case TCP_TIMELY_DYN_ADJ:
19066 		RACK_OPTS_INC(tcp_timely_dyn);
19067 		if (optval == 0)
19068 			rack->rc_gp_dyn_mul = 0;
19069 		else {
19070 			rack->rc_gp_dyn_mul = 1;
19071 			if (optval >= 100) {
19072 				/*
19073 				 * If the user sets something 100 or more
19074 				 * its the gp_ca value.
19075 				 */
19076 				rack->r_ctl.rack_per_of_gp_ca  = optval;
19077 			}
19078 		}
19079 		break;
19080 	case TCP_RACK_DO_DETECTION:
19081 		RACK_OPTS_INC(tcp_rack_do_detection);
19082 		if (optval == 0)
19083 			rack->do_detection = 0;
19084 		else
19085 			rack->do_detection = 1;
19086 		break;
19087 	case TCP_RACK_TLP_USE:
19088 		if ((optval < TLP_USE_ID) || (optval > TLP_USE_TWO_TWO)) {
19089 			error = EINVAL;
19090 			break;
19091 		}
19092 		RACK_OPTS_INC(tcp_tlp_use);
19093 		rack->rack_tlp_threshold_use = optval;
19094 		break;
19095 	case TCP_RACK_TLP_REDUCE:
19096 		/* RACK TLP cwnd reduction (bool) */
19097 		RACK_OPTS_INC(tcp_rack_tlp_reduce);
19098 		rack->r_ctl.rc_tlp_cwnd_reduce = optval;
19099 		break;
19100 	/*  Pacing related ones */
19101 	case TCP_RACK_PACE_ALWAYS:
19102 		/*
19103 		 * zero is old rack method, 1 is new
19104 		 * method using a pacing rate.
19105 		 */
19106 		RACK_OPTS_INC(tcp_rack_pace_always);
19107 		if (optval > 0) {
19108 			if (rack->rc_always_pace) {
19109 				error = EALREADY;
19110 				break;
19111 			} else if (tcp_can_enable_pacing()) {
19112 				rack->rc_always_pace = 1;
19113 				if (rack->use_fixed_rate || rack->gp_ready)
19114 					rack_set_cc_pacing(rack);
19115 			}
19116 			else {
19117 				error = ENOSPC;
19118 				break;
19119 			}
19120 		} else {
19121 			if (rack->rc_always_pace) {
19122 				tcp_decrement_paced_conn();
19123 				rack->rc_always_pace = 0;
19124 				rack_undo_cc_pacing(rack);
19125 			}
19126 		}
19127 		if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
19128 			tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19129 		else
19130 			tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
19131 		/* A rate may be set irate or other, if so set seg size */
19132 		rack_update_seg(rack);
19133 		break;
19134 	case TCP_BBR_RACK_INIT_RATE:
19135 		RACK_OPTS_INC(tcp_initial_rate);
19136 		val = optval;
19137 		/* Change from kbits per second to bytes per second */
19138 		val *= 1000;
19139 		val /= 8;
19140 		rack->r_ctl.init_rate = val;
19141 		if (rack->rc_init_win != rack_default_init_window) {
19142 			uint32_t win, snt;
19143 
19144 			/*
19145 			 * Options don't always get applied
19146 			 * in the order you think. So in order
19147 			 * to assure we update a cwnd we need
19148 			 * to check and see if we are still
19149 			 * where we should raise the cwnd.
19150 			 */
19151 			win = rc_init_window(rack);
19152 			if (SEQ_GT(tp->snd_max, tp->iss))
19153 				snt = tp->snd_max - tp->iss;
19154 			else
19155 				snt = 0;
19156 			if ((snt < win) &&
19157 			    (tp->snd_cwnd < win))
19158 				tp->snd_cwnd = win;
19159 		}
19160 		if (rack->rc_always_pace)
19161 			rack_update_seg(rack);
19162 		break;
19163 	case TCP_BBR_IWINTSO:
19164 		RACK_OPTS_INC(tcp_initial_win);
19165 		if (optval && (optval <= 0xff)) {
19166 			uint32_t win, snt;
19167 
19168 			rack->rc_init_win = optval;
19169 			win = rc_init_window(rack);
19170 			if (SEQ_GT(tp->snd_max, tp->iss))
19171 				snt = tp->snd_max - tp->iss;
19172 			else
19173 				snt = 0;
19174 			if ((snt < win) &&
19175 			    (tp->t_srtt |
19176 #ifdef NETFLIX_PEAKRATE
19177 			     tp->t_maxpeakrate |
19178 #endif
19179 			     rack->r_ctl.init_rate)) {
19180 				/*
19181 				 * We are not past the initial window
19182 				 * and we have some bases for pacing,
19183 				 * so we need to possibly adjust up
19184 				 * the cwnd. Note even if we don't set
19185 				 * the cwnd, its still ok to raise the rc_init_win
19186 				 * which can be used coming out of idle when we
19187 				 * would have a rate.
19188 				 */
19189 				if (tp->snd_cwnd < win)
19190 					tp->snd_cwnd = win;
19191 			}
19192 			if (rack->rc_always_pace)
19193 				rack_update_seg(rack);
19194 		} else
19195 			error = EINVAL;
19196 		break;
19197 	case TCP_RACK_FORCE_MSEG:
19198 		RACK_OPTS_INC(tcp_rack_force_max_seg);
19199 		if (optval)
19200 			rack->rc_force_max_seg = 1;
19201 		else
19202 			rack->rc_force_max_seg = 0;
19203 		break;
19204 	case TCP_RACK_PACE_MAX_SEG:
19205 		/* Max segments size in a pace in bytes */
19206 		RACK_OPTS_INC(tcp_rack_max_seg);
19207 		rack->rc_user_set_max_segs = optval;
19208 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
19209 		break;
19210 	case TCP_RACK_PACE_RATE_REC:
19211 		/* Set the fixed pacing rate in Bytes per second ca */
19212 		RACK_OPTS_INC(tcp_rack_pace_rate_rec);
19213 		rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
19214 		if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
19215 			rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
19216 		if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
19217 			rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
19218 		rack->use_fixed_rate = 1;
19219 		if (rack->rc_always_pace)
19220 			rack_set_cc_pacing(rack);
19221 		rack_log_pacing_delay_calc(rack,
19222 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
19223 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
19224 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
19225 					   __LINE__, NULL);
19226 		break;
19227 
19228 	case TCP_RACK_PACE_RATE_SS:
19229 		/* Set the fixed pacing rate in Bytes per second ca */
19230 		RACK_OPTS_INC(tcp_rack_pace_rate_ss);
19231 		rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
19232 		if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
19233 			rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
19234 		if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
19235 			rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
19236 		rack->use_fixed_rate = 1;
19237 		if (rack->rc_always_pace)
19238 			rack_set_cc_pacing(rack);
19239 		rack_log_pacing_delay_calc(rack,
19240 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
19241 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
19242 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
19243 					   __LINE__, NULL);
19244 		break;
19245 
19246 	case TCP_RACK_PACE_RATE_CA:
19247 		/* Set the fixed pacing rate in Bytes per second ca */
19248 		RACK_OPTS_INC(tcp_rack_pace_rate_ca);
19249 		rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
19250 		if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
19251 			rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
19252 		if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
19253 			rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
19254 		rack->use_fixed_rate = 1;
19255 		if (rack->rc_always_pace)
19256 			rack_set_cc_pacing(rack);
19257 		rack_log_pacing_delay_calc(rack,
19258 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
19259 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
19260 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
19261 					   __LINE__, NULL);
19262 		break;
19263 	case TCP_RACK_GP_INCREASE_REC:
19264 		RACK_OPTS_INC(tcp_gp_inc_rec);
19265 		rack->r_ctl.rack_per_of_gp_rec = optval;
19266 		rack_log_pacing_delay_calc(rack,
19267 					   rack->r_ctl.rack_per_of_gp_ss,
19268 					   rack->r_ctl.rack_per_of_gp_ca,
19269 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
19270 					   __LINE__, NULL);
19271 		break;
19272 	case TCP_RACK_GP_INCREASE_CA:
19273 		RACK_OPTS_INC(tcp_gp_inc_ca);
19274 		ca = optval;
19275 		if (ca < 100) {
19276 			/*
19277 			 * We don't allow any reduction
19278 			 * over the GP b/w.
19279 			 */
19280 			error = EINVAL;
19281 			break;
19282 		}
19283 		rack->r_ctl.rack_per_of_gp_ca = ca;
19284 		rack_log_pacing_delay_calc(rack,
19285 					   rack->r_ctl.rack_per_of_gp_ss,
19286 					   rack->r_ctl.rack_per_of_gp_ca,
19287 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
19288 					   __LINE__, NULL);
19289 		break;
19290 	case TCP_RACK_GP_INCREASE_SS:
19291 		RACK_OPTS_INC(tcp_gp_inc_ss);
19292 		ss = optval;
19293 		if (ss < 100) {
19294 			/*
19295 			 * We don't allow any reduction
19296 			 * over the GP b/w.
19297 			 */
19298 			error = EINVAL;
19299 			break;
19300 		}
19301 		rack->r_ctl.rack_per_of_gp_ss = ss;
19302 		rack_log_pacing_delay_calc(rack,
19303 					   rack->r_ctl.rack_per_of_gp_ss,
19304 					   rack->r_ctl.rack_per_of_gp_ca,
19305 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
19306 					   __LINE__, NULL);
19307 		break;
19308 	case TCP_RACK_RR_CONF:
19309 		RACK_OPTS_INC(tcp_rack_rrr_no_conf_rate);
19310 		if (optval && optval <= 3)
19311 			rack->r_rr_config = optval;
19312 		else
19313 			rack->r_rr_config = 0;
19314 		break;
19315 	case TCP_HDWR_RATE_CAP:
19316 		RACK_OPTS_INC(tcp_hdwr_rate_cap);
19317 		if (optval) {
19318 			if (rack->r_rack_hw_rate_caps == 0)
19319 				rack->r_rack_hw_rate_caps = 1;
19320 			else
19321 				error = EALREADY;
19322 		} else {
19323 			rack->r_rack_hw_rate_caps = 0;
19324 		}
19325 		break;
19326 	case TCP_BBR_HDWR_PACE:
19327 		RACK_OPTS_INC(tcp_hdwr_pacing);
19328 		if (optval){
19329 			if (rack->rack_hdrw_pacing == 0) {
19330 				rack->rack_hdw_pace_ena = 1;
19331 				rack->rack_attempt_hdwr_pace = 0;
19332 			} else
19333 				error = EALREADY;
19334 		} else {
19335 			rack->rack_hdw_pace_ena = 0;
19336 #ifdef RATELIMIT
19337 			if (rack->r_ctl.crte != NULL) {
19338 				rack->rack_hdrw_pacing = 0;
19339 				rack->rack_attempt_hdwr_pace = 0;
19340 				tcp_rel_pacing_rate(rack->r_ctl.crte, tp);
19341 				rack->r_ctl.crte = NULL;
19342 			}
19343 #endif
19344 		}
19345 		break;
19346 	/*  End Pacing related ones */
19347 	case TCP_RACK_PRR_SENDALOT:
19348 		/* Allow PRR to send more than one seg */
19349 		RACK_OPTS_INC(tcp_rack_prr_sendalot);
19350 		rack->r_ctl.rc_prr_sendalot = optval;
19351 		break;
19352 	case TCP_RACK_MIN_TO:
19353 		/* Minimum time between rack t-o's in ms */
19354 		RACK_OPTS_INC(tcp_rack_min_to);
19355 		rack->r_ctl.rc_min_to = optval;
19356 		break;
19357 	case TCP_RACK_EARLY_SEG:
19358 		/* If early recovery max segments */
19359 		RACK_OPTS_INC(tcp_rack_early_seg);
19360 		rack->r_ctl.rc_early_recovery_segs = optval;
19361 		break;
19362 	case TCP_RACK_REORD_THRESH:
19363 		/* RACK reorder threshold (shift amount) */
19364 		RACK_OPTS_INC(tcp_rack_reord_thresh);
19365 		if ((optval > 0) && (optval < 31))
19366 			rack->r_ctl.rc_reorder_shift = optval;
19367 		else
19368 			error = EINVAL;
19369 		break;
19370 	case TCP_RACK_REORD_FADE:
19371 		/* Does reordering fade after ms time */
19372 		RACK_OPTS_INC(tcp_rack_reord_fade);
19373 		rack->r_ctl.rc_reorder_fade = optval;
19374 		break;
19375 	case TCP_RACK_TLP_THRESH:
19376 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
19377 		RACK_OPTS_INC(tcp_rack_tlp_thresh);
19378 		if (optval)
19379 			rack->r_ctl.rc_tlp_threshold = optval;
19380 		else
19381 			error = EINVAL;
19382 		break;
19383 	case TCP_BBR_USE_RACK_RR:
19384 		RACK_OPTS_INC(tcp_rack_rr);
19385 		if (optval)
19386 			rack->use_rack_rr = 1;
19387 		else
19388 			rack->use_rack_rr = 0;
19389 		break;
19390 	case TCP_FAST_RSM_HACK:
19391 		RACK_OPTS_INC(tcp_rack_fastrsm_hack);
19392 		if (optval)
19393 			rack->fast_rsm_hack = 1;
19394 		else
19395 			rack->fast_rsm_hack = 0;
19396 		break;
19397 	case TCP_RACK_PKT_DELAY:
19398 		/* RACK added ms i.e. rack-rtt + reord + N */
19399 		RACK_OPTS_INC(tcp_rack_pkt_delay);
19400 		rack->r_ctl.rc_pkt_delay = optval;
19401 		break;
19402 	case TCP_DELACK:
19403 		RACK_OPTS_INC(tcp_rack_delayed_ack);
19404 		if (optval == 0)
19405 			tp->t_delayed_ack = 0;
19406 		else
19407 			tp->t_delayed_ack = 1;
19408 		if (tp->t_flags & TF_DELACK) {
19409 			tp->t_flags &= ~TF_DELACK;
19410 			tp->t_flags |= TF_ACKNOW;
19411 			NET_EPOCH_ENTER(et);
19412 			rack_output(tp);
19413 			NET_EPOCH_EXIT(et);
19414 		}
19415 		break;
19416 
19417 	case TCP_BBR_RACK_RTT_USE:
19418 		RACK_OPTS_INC(tcp_rack_rtt_use);
19419 		if ((optval != USE_RTT_HIGH) &&
19420 		    (optval != USE_RTT_LOW) &&
19421 		    (optval != USE_RTT_AVG))
19422 			error = EINVAL;
19423 		else
19424 			rack->r_ctl.rc_rate_sample_method = optval;
19425 		break;
19426 	case TCP_DATA_AFTER_CLOSE:
19427 		RACK_OPTS_INC(tcp_data_after_close);
19428 		if (optval)
19429 			rack->rc_allow_data_af_clo = 1;
19430 		else
19431 			rack->rc_allow_data_af_clo = 0;
19432 		break;
19433 	default:
19434 		break;
19435 	}
19436 #ifdef NETFLIX_STATS
19437 	tcp_log_socket_option(tp, sopt_name, optval, error);
19438 #endif
19439 	return (error);
19440 }
19441 
19442 
19443 static void
19444 rack_apply_deferred_options(struct tcp_rack *rack)
19445 {
19446 	struct deferred_opt_list *dol, *sdol;
19447 	uint32_t s_optval;
19448 
19449 	TAILQ_FOREACH_SAFE(dol, &rack->r_ctl.opt_list, next, sdol) {
19450 		TAILQ_REMOVE(&rack->r_ctl.opt_list, dol, next);
19451 		/* Disadvantage of deferal is you loose the error return */
19452 		s_optval = (uint32_t)dol->optval;
19453 		(void)rack_process_option(rack->rc_tp, rack, dol->optname, s_optval, dol->optval);
19454 		free(dol, M_TCPDO);
19455 	}
19456 }
19457 
19458 static int
19459 rack_pru_options(struct tcpcb *tp, int flags)
19460 {
19461 	if (flags & PRUS_OOB)
19462 		return (EOPNOTSUPP);
19463 	return (0);
19464 }
19465 
19466 static struct tcp_function_block __tcp_rack = {
19467 	.tfb_tcp_block_name = __XSTRING(STACKNAME),
19468 	.tfb_tcp_output = rack_output,
19469 	.tfb_do_queued_segments = ctf_do_queued_segments,
19470 	.tfb_do_segment_nounlock = rack_do_segment_nounlock,
19471 	.tfb_tcp_do_segment = rack_do_segment,
19472 	.tfb_tcp_ctloutput = rack_ctloutput,
19473 	.tfb_tcp_fb_init = rack_init,
19474 	.tfb_tcp_fb_fini = rack_fini,
19475 	.tfb_tcp_timer_stop_all = rack_stopall,
19476 	.tfb_tcp_timer_activate = rack_timer_activate,
19477 	.tfb_tcp_timer_active = rack_timer_active,
19478 	.tfb_tcp_timer_stop = rack_timer_stop,
19479 	.tfb_tcp_rexmit_tmr = rack_remxt_tmr,
19480 	.tfb_tcp_handoff_ok = rack_handoff_ok,
19481 	.tfb_tcp_mtu_chg = rack_mtu_change,
19482 	.tfb_pru_options = rack_pru_options,
19483 
19484 };
19485 
19486 /*
19487  * rack_ctloutput() must drop the inpcb lock before performing copyin on
19488  * socket option arguments.  When it re-acquires the lock after the copy, it
19489  * has to revalidate that the connection is still valid for the socket
19490  * option.
19491  */
19492 static int
19493 rack_set_sockopt(struct socket *so, struct sockopt *sopt,
19494     struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack)
19495 {
19496 	uint64_t loptval;
19497 	int32_t error = 0, optval;
19498 
19499 	switch (sopt->sopt_name) {
19500 	case TCP_RACK_TLP_REDUCE:		/*  URL:tlp_reduce */
19501 	/*  Pacing related ones */
19502 	case TCP_RACK_PACE_ALWAYS:		/*  URL:pace_always */
19503 	case TCP_BBR_RACK_INIT_RATE:		/*  URL:irate */
19504 	case TCP_BBR_IWINTSO:			/*  URL:tso_iwin */
19505 	case TCP_RACK_PACE_MAX_SEG:		/*  URL:pace_max_seg */
19506 	case TCP_RACK_FORCE_MSEG:		/*  URL:force_max_seg */
19507 	case TCP_RACK_PACE_RATE_CA:		/*  URL:pr_ca */
19508 	case TCP_RACK_PACE_RATE_SS:		/*  URL:pr_ss*/
19509 	case TCP_RACK_PACE_RATE_REC:		/*  URL:pr_rec */
19510 	case TCP_RACK_GP_INCREASE_CA:		/*  URL:gp_inc_ca */
19511 	case TCP_RACK_GP_INCREASE_SS:		/*  URL:gp_inc_ss */
19512 	case TCP_RACK_GP_INCREASE_REC:		/*  URL:gp_inc_rec */
19513 	case TCP_RACK_RR_CONF:			/*  URL:rrr_conf */
19514 	case TCP_BBR_HDWR_PACE:			/*  URL:hdwrpace */
19515 	case TCP_HDWR_RATE_CAP:			/*  URL: hdwrcap boolean */
19516 	case TCP_PACING_RATE_CAP:		/*  URL:cap-- used by side-channel */
19517 	case TCP_HDWR_UP_ONLY:			/*  URL:uponly -- hardware pacing  boolean */
19518        /* End pacing related */
19519 	case TCP_FAST_RSM_HACK:			/*  URL:frsm_hack */
19520 	case TCP_DELACK:			/*  URL:delack (in base TCP i.e. tcp_hints along with cc etc ) */
19521 	case TCP_RACK_PRR_SENDALOT:		/*  URL:prr_sendalot */
19522 	case TCP_RACK_MIN_TO:			/*  URL:min_to */
19523 	case TCP_RACK_EARLY_SEG:		/*  URL:early_seg */
19524 	case TCP_RACK_REORD_THRESH:		/*  URL:reord_thresh */
19525 	case TCP_RACK_REORD_FADE:		/*  URL:reord_fade */
19526 	case TCP_RACK_TLP_THRESH:		/*  URL:tlp_thresh */
19527 	case TCP_RACK_PKT_DELAY:		/*  URL:pkt_delay */
19528 	case TCP_RACK_TLP_USE:			/*  URL:tlp_use */
19529 	case TCP_BBR_RACK_RTT_USE:		/*  URL:rttuse */
19530 	case TCP_BBR_USE_RACK_RR:		/*  URL:rackrr */
19531 	case TCP_RACK_DO_DETECTION:		/*  URL:detect */
19532 	case TCP_NO_PRR:			/*  URL:noprr */
19533 	case TCP_TIMELY_DYN_ADJ:      		/*  URL:dynamic */
19534 	case TCP_DATA_AFTER_CLOSE:		/*  no URL */
19535 	case TCP_RACK_NONRXT_CFG_RATE:		/*  URL:nonrxtcr */
19536 	case TCP_SHARED_CWND_ENABLE:		/*  URL:scwnd */
19537 	case TCP_RACK_MBUF_QUEUE:		/*  URL:mqueue */
19538 	case TCP_RACK_NO_PUSH_AT_MAX:		/*  URL:npush */
19539 	case TCP_RACK_PACE_TO_FILL:		/*  URL:fillcw */
19540 	case TCP_SHARED_CWND_TIME_LIMIT:	/*  URL:lscwnd */
19541 	case TCP_RACK_PROFILE:			/*  URL:profile */
19542 	case TCP_USE_CMP_ACKS:			/*  URL:cmpack */
19543 	case TCP_RACK_ABC_VAL:			/*  URL:labc */
19544 	case TCP_REC_ABC_VAL:			/*  URL:reclabc */
19545 	case TCP_RACK_MEASURE_CNT:		/*  URL:measurecnt */
19546 	case TCP_DEFER_OPTIONS:			/*  URL:defer */
19547 	case TCP_RACK_PACING_BETA:		/*  URL:pacing_beta */
19548 	case TCP_RACK_PACING_BETA_ECN:		/*  URL:pacing_beta_ecn */
19549 	case TCP_RACK_TIMER_SLOP:		/*  URL:timer_slop */
19550 		break;
19551 	default:
19552 		/* Filter off all unknown options to the base stack */
19553 		return (tcp_default_ctloutput(so, sopt, inp, tp));
19554 		break;
19555 	}
19556 	INP_WUNLOCK(inp);
19557 	if (sopt->sopt_name == TCP_PACING_RATE_CAP) {
19558 		error = sooptcopyin(sopt, &loptval, sizeof(loptval), sizeof(loptval));
19559 		/*
19560 		 * We truncate it down to 32 bits for the socket-option trace this
19561 		 * means rates > 34Gbps won't show right, but thats probably ok.
19562 		 */
19563 		optval = (uint32_t)loptval;
19564 	} else {
19565 		error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval));
19566 		/* Save it in 64 bit form too */
19567 		loptval = optval;
19568 	}
19569 	if (error)
19570 		return (error);
19571 	INP_WLOCK(inp);
19572 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
19573 		INP_WUNLOCK(inp);
19574 		return (ECONNRESET);
19575 	}
19576 	if (tp->t_fb != &__tcp_rack) {
19577 		INP_WUNLOCK(inp);
19578 		return (ENOPROTOOPT);
19579 	}
19580 	if (rack->defer_options && (rack->gp_ready == 0) &&
19581 	    (sopt->sopt_name != TCP_DEFER_OPTIONS) &&
19582 	    (sopt->sopt_name != TCP_RACK_PACING_BETA) &&
19583 	    (sopt->sopt_name != TCP_RACK_PACING_BETA_ECN) &&
19584 	    (sopt->sopt_name != TCP_RACK_MEASURE_CNT)) {
19585 		/* Options are beind deferred */
19586 		if (rack_add_deferred_option(rack, sopt->sopt_name, loptval)) {
19587 			INP_WUNLOCK(inp);
19588 			return (0);
19589 		} else {
19590 			/* No memory to defer, fail */
19591 			INP_WUNLOCK(inp);
19592 			return (ENOMEM);
19593 		}
19594 	}
19595 	error = rack_process_option(tp, rack, sopt->sopt_name, optval, loptval);
19596 	INP_WUNLOCK(inp);
19597 	return (error);
19598 }
19599 
19600 static void
19601 rack_fill_info(struct tcpcb *tp, struct tcp_info *ti)
19602 {
19603 
19604 	INP_WLOCK_ASSERT(tp->t_inpcb);
19605 	bzero(ti, sizeof(*ti));
19606 
19607 	ti->tcpi_state = tp->t_state;
19608 	if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
19609 		ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
19610 	if (tp->t_flags & TF_SACK_PERMIT)
19611 		ti->tcpi_options |= TCPI_OPT_SACK;
19612 	if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
19613 		ti->tcpi_options |= TCPI_OPT_WSCALE;
19614 		ti->tcpi_snd_wscale = tp->snd_scale;
19615 		ti->tcpi_rcv_wscale = tp->rcv_scale;
19616 	}
19617 	if (tp->t_flags2 & TF2_ECN_PERMIT)
19618 		ti->tcpi_options |= TCPI_OPT_ECN;
19619 	if (tp->t_flags & TF_FASTOPEN)
19620 		ti->tcpi_options |= TCPI_OPT_TFO;
19621 	/* still kept in ticks is t_rcvtime */
19622 	ti->tcpi_last_data_recv = ((uint32_t)ticks - tp->t_rcvtime) * tick;
19623 	/* Since we hold everything in precise useconds this is easy */
19624 	ti->tcpi_rtt = tp->t_srtt;
19625 	ti->tcpi_rttvar = tp->t_rttvar;
19626 	ti->tcpi_rto = tp->t_rxtcur;
19627 	ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
19628 	ti->tcpi_snd_cwnd = tp->snd_cwnd;
19629 	/*
19630 	 * FreeBSD-specific extension fields for tcp_info.
19631 	 */
19632 	ti->tcpi_rcv_space = tp->rcv_wnd;
19633 	ti->tcpi_rcv_nxt = tp->rcv_nxt;
19634 	ti->tcpi_snd_wnd = tp->snd_wnd;
19635 	ti->tcpi_snd_bwnd = 0;		/* Unused, kept for compat. */
19636 	ti->tcpi_snd_nxt = tp->snd_nxt;
19637 	ti->tcpi_snd_mss = tp->t_maxseg;
19638 	ti->tcpi_rcv_mss = tp->t_maxseg;
19639 	ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;
19640 	ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
19641 	ti->tcpi_snd_zerowin = tp->t_sndzerowin;
19642 #ifdef NETFLIX_STATS
19643 	ti->tcpi_total_tlp = tp->t_sndtlppack;
19644 	ti->tcpi_total_tlp_bytes = tp->t_sndtlpbyte;
19645 	memcpy(&ti->tcpi_rxsyninfo, &tp->t_rxsyninfo, sizeof(struct tcpsyninfo));
19646 #endif
19647 #ifdef TCP_OFFLOAD
19648 	if (tp->t_flags & TF_TOE) {
19649 		ti->tcpi_options |= TCPI_OPT_TOE;
19650 		tcp_offload_tcp_info(tp, ti);
19651 	}
19652 #endif
19653 }
19654 
19655 static int
19656 rack_get_sockopt(struct socket *so, struct sockopt *sopt,
19657     struct inpcb *inp, struct tcpcb *tp, struct tcp_rack *rack)
19658 {
19659 	int32_t error, optval;
19660 	uint64_t val, loptval;
19661 	struct	tcp_info ti;
19662 	/*
19663 	 * Because all our options are either boolean or an int, we can just
19664 	 * pull everything into optval and then unlock and copy. If we ever
19665 	 * add a option that is not a int, then this will have quite an
19666 	 * impact to this routine.
19667 	 */
19668 	error = 0;
19669 	switch (sopt->sopt_name) {
19670 	case TCP_INFO:
19671 		/* First get the info filled */
19672 		rack_fill_info(tp, &ti);
19673 		/* Fix up the rtt related fields if needed */
19674 		INP_WUNLOCK(inp);
19675 		error = sooptcopyout(sopt, &ti, sizeof ti);
19676 		return (error);
19677 	/*
19678 	 * Beta is the congestion control value for NewReno that influences how
19679 	 * much of a backoff happens when loss is detected. It is normally set
19680 	 * to 50 for 50% i.e. the cwnd is reduced to 50% of its previous value
19681 	 * when you exit recovery.
19682 	 */
19683 	case TCP_RACK_PACING_BETA:
19684 		if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0)
19685 			error = EINVAL;
19686 		else if (rack->rc_pacing_cc_set == 0)
19687 			optval = rack->r_ctl.rc_saved_beta.beta;
19688 		else {
19689 			/*
19690 			 * Reach out into the CC data and report back what
19691 			 * I have previously set. Yeah it looks hackish but
19692 			 * we don't want to report the saved values.
19693 			 */
19694 			if (tp->ccv->cc_data)
19695 				optval = ((struct newreno *)tp->ccv->cc_data)->beta;
19696 			else
19697 				error = EINVAL;
19698 		}
19699 		break;
19700 		/*
19701 		 * Beta_ecn is the congestion control value for NewReno that influences how
19702 		 * much of a backoff happens when a ECN mark is detected. It is normally set
19703 		 * to 80 for 80% i.e. the cwnd is reduced by 20% of its previous value when
19704 		 * you exit recovery. Note that classic ECN has a beta of 50, it is only
19705 		 * ABE Ecn that uses this "less" value, but we do too with pacing :)
19706 		 */
19707 
19708 	case TCP_RACK_PACING_BETA_ECN:
19709 		if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0)
19710 			error = EINVAL;
19711 		else if (rack->rc_pacing_cc_set == 0)
19712 			optval = rack->r_ctl.rc_saved_beta.beta_ecn;
19713 		else {
19714 			/*
19715 			 * Reach out into the CC data and report back what
19716 			 * I have previously set. Yeah it looks hackish but
19717 			 * we don't want to report the saved values.
19718 			 */
19719 			if (tp->ccv->cc_data)
19720 				optval = ((struct newreno *)tp->ccv->cc_data)->beta_ecn;
19721 			else
19722 				error = EINVAL;
19723 		}
19724 		break;
19725 	case TCP_FAST_RSM_HACK:
19726 		optval = rack->fast_rsm_hack;
19727 		break;
19728 	case TCP_DEFER_OPTIONS:
19729 		optval = rack->defer_options;
19730 		break;
19731 	case TCP_RACK_MEASURE_CNT:
19732 		optval = rack->r_ctl.req_measurements;
19733 		break;
19734 	case TCP_REC_ABC_VAL:
19735 		optval = rack->r_use_labc_for_rec;
19736 		break;
19737 	case TCP_RACK_ABC_VAL:
19738 		optval = rack->rc_labc;
19739 		break;
19740 	case TCP_HDWR_UP_ONLY:
19741 		optval= rack->r_up_only;
19742 		break;
19743 	case TCP_PACING_RATE_CAP:
19744 		loptval = rack->r_ctl.bw_rate_cap;
19745 		break;
19746 	case TCP_RACK_PROFILE:
19747 		/* You cannot retrieve a profile, its write only */
19748 		error = EINVAL;
19749 		break;
19750 	case TCP_USE_CMP_ACKS:
19751 		optval = rack->r_use_cmp_ack;
19752 		break;
19753 	case TCP_RACK_PACE_TO_FILL:
19754 		optval = rack->rc_pace_to_cwnd;
19755 		if (optval && rack->r_fill_less_agg)
19756 			optval++;
19757 		break;
19758 	case TCP_RACK_NO_PUSH_AT_MAX:
19759 		optval = rack->r_ctl.rc_no_push_at_mrtt;
19760 		break;
19761 	case TCP_SHARED_CWND_ENABLE:
19762 		optval = rack->rack_enable_scwnd;
19763 		break;
19764 	case TCP_RACK_NONRXT_CFG_RATE:
19765 		optval = rack->rack_rec_nonrxt_use_cr;
19766 		break;
19767 	case TCP_NO_PRR:
19768 		if (rack->rack_no_prr  == 1)
19769 			optval = 1;
19770 		else if (rack->no_prr_addback == 1)
19771 			optval = 2;
19772 		else
19773 			optval = 0;
19774 		break;
19775 	case TCP_RACK_DO_DETECTION:
19776 		optval = rack->do_detection;
19777 		break;
19778 	case TCP_RACK_MBUF_QUEUE:
19779 		/* Now do we use the LRO mbuf-queue feature */
19780 		optval = rack->r_mbuf_queue;
19781 		break;
19782 	case TCP_TIMELY_DYN_ADJ:
19783 		optval = rack->rc_gp_dyn_mul;
19784 		break;
19785 	case TCP_BBR_IWINTSO:
19786 		optval = rack->rc_init_win;
19787 		break;
19788 	case TCP_RACK_TLP_REDUCE:
19789 		/* RACK TLP cwnd reduction (bool) */
19790 		optval = rack->r_ctl.rc_tlp_cwnd_reduce;
19791 		break;
19792 	case TCP_BBR_RACK_INIT_RATE:
19793 		val = rack->r_ctl.init_rate;
19794 		/* convert to kbits per sec */
19795 		val *= 8;
19796 		val /= 1000;
19797 		optval = (uint32_t)val;
19798 		break;
19799 	case TCP_RACK_FORCE_MSEG:
19800 		optval = rack->rc_force_max_seg;
19801 		break;
19802 	case TCP_RACK_PACE_MAX_SEG:
19803 		/* Max segments in a pace */
19804 		optval = rack->rc_user_set_max_segs;
19805 		break;
19806 	case TCP_RACK_PACE_ALWAYS:
19807 		/* Use the always pace method */
19808 		optval = rack->rc_always_pace;
19809 		break;
19810 	case TCP_RACK_PRR_SENDALOT:
19811 		/* Allow PRR to send more than one seg */
19812 		optval = rack->r_ctl.rc_prr_sendalot;
19813 		break;
19814 	case TCP_RACK_MIN_TO:
19815 		/* Minimum time between rack t-o's in ms */
19816 		optval = rack->r_ctl.rc_min_to;
19817 		break;
19818 	case TCP_RACK_EARLY_SEG:
19819 		/* If early recovery max segments */
19820 		optval = rack->r_ctl.rc_early_recovery_segs;
19821 		break;
19822 	case TCP_RACK_REORD_THRESH:
19823 		/* RACK reorder threshold (shift amount) */
19824 		optval = rack->r_ctl.rc_reorder_shift;
19825 		break;
19826 	case TCP_RACK_REORD_FADE:
19827 		/* Does reordering fade after ms time */
19828 		optval = rack->r_ctl.rc_reorder_fade;
19829 		break;
19830 	case TCP_BBR_USE_RACK_RR:
19831 		/* Do we use the rack cheat for rxt */
19832 		optval = rack->use_rack_rr;
19833 		break;
19834 	case TCP_RACK_RR_CONF:
19835 		optval = rack->r_rr_config;
19836 		break;
19837 	case TCP_HDWR_RATE_CAP:
19838 		optval = rack->r_rack_hw_rate_caps;
19839 		break;
19840 	case TCP_BBR_HDWR_PACE:
19841 		optval = rack->rack_hdw_pace_ena;
19842 		break;
19843 	case TCP_RACK_TLP_THRESH:
19844 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
19845 		optval = rack->r_ctl.rc_tlp_threshold;
19846 		break;
19847 	case TCP_RACK_PKT_DELAY:
19848 		/* RACK added ms i.e. rack-rtt + reord + N */
19849 		optval = rack->r_ctl.rc_pkt_delay;
19850 		break;
19851 	case TCP_RACK_TLP_USE:
19852 		optval = rack->rack_tlp_threshold_use;
19853 		break;
19854 	case TCP_RACK_PACE_RATE_CA:
19855 		optval = rack->r_ctl.rc_fixed_pacing_rate_ca;
19856 		break;
19857 	case TCP_RACK_PACE_RATE_SS:
19858 		optval = rack->r_ctl.rc_fixed_pacing_rate_ss;
19859 		break;
19860 	case TCP_RACK_PACE_RATE_REC:
19861 		optval = rack->r_ctl.rc_fixed_pacing_rate_rec;
19862 		break;
19863 	case TCP_RACK_GP_INCREASE_SS:
19864 		optval = rack->r_ctl.rack_per_of_gp_ca;
19865 		break;
19866 	case TCP_RACK_GP_INCREASE_CA:
19867 		optval = rack->r_ctl.rack_per_of_gp_ss;
19868 		break;
19869 	case TCP_BBR_RACK_RTT_USE:
19870 		optval = rack->r_ctl.rc_rate_sample_method;
19871 		break;
19872 	case TCP_DELACK:
19873 		optval = tp->t_delayed_ack;
19874 		break;
19875 	case TCP_DATA_AFTER_CLOSE:
19876 		optval = rack->rc_allow_data_af_clo;
19877 		break;
19878 	case TCP_SHARED_CWND_TIME_LIMIT:
19879 		optval = rack->r_limit_scw;
19880 		break;
19881 	case TCP_RACK_TIMER_SLOP:
19882 		optval = rack->r_ctl.timer_slop;
19883 		break;
19884 	default:
19885 		return (tcp_default_ctloutput(so, sopt, inp, tp));
19886 		break;
19887 	}
19888 	INP_WUNLOCK(inp);
19889 	if (error == 0) {
19890 		if (TCP_PACING_RATE_CAP)
19891 			error = sooptcopyout(sopt, &loptval, sizeof loptval);
19892 		else
19893 			error = sooptcopyout(sopt, &optval, sizeof optval);
19894 	}
19895 	return (error);
19896 }
19897 
19898 static int
19899 rack_ctloutput(struct socket *so, struct sockopt *sopt, struct inpcb *inp, struct tcpcb *tp)
19900 {
19901 	int32_t error = EINVAL;
19902 	struct tcp_rack *rack;
19903 
19904 	rack = (struct tcp_rack *)tp->t_fb_ptr;
19905 	if (rack == NULL) {
19906 		/* Huh? */
19907 		goto out;
19908 	}
19909 	if (sopt->sopt_dir == SOPT_SET) {
19910 		return (rack_set_sockopt(so, sopt, inp, tp, rack));
19911 	} else if (sopt->sopt_dir == SOPT_GET) {
19912 		return (rack_get_sockopt(so, sopt, inp, tp, rack));
19913 	}
19914 out:
19915 	INP_WUNLOCK(inp);
19916 	return (error);
19917 }
19918 
19919 static const char *rack_stack_names[] = {
19920 	__XSTRING(STACKNAME),
19921 #ifdef STACKALIAS
19922 	__XSTRING(STACKALIAS),
19923 #endif
19924 };
19925 
19926 static int
19927 rack_ctor(void *mem, int32_t size, void *arg, int32_t how)
19928 {
19929 	memset(mem, 0, size);
19930 	return (0);
19931 }
19932 
19933 static void
19934 rack_dtor(void *mem, int32_t size, void *arg)
19935 {
19936 
19937 }
19938 
19939 static bool rack_mod_inited = false;
19940 
19941 static int
19942 tcp_addrack(module_t mod, int32_t type, void *data)
19943 {
19944 	int32_t err = 0;
19945 	int num_stacks;
19946 
19947 	switch (type) {
19948 	case MOD_LOAD:
19949 		rack_zone = uma_zcreate(__XSTRING(MODNAME) "_map",
19950 		    sizeof(struct rack_sendmap),
19951 		    rack_ctor, rack_dtor, NULL, NULL, UMA_ALIGN_PTR, 0);
19952 
19953 		rack_pcb_zone = uma_zcreate(__XSTRING(MODNAME) "_pcb",
19954 		    sizeof(struct tcp_rack),
19955 		    rack_ctor, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
19956 
19957 		sysctl_ctx_init(&rack_sysctl_ctx);
19958 		rack_sysctl_root = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
19959 		    SYSCTL_STATIC_CHILDREN(_net_inet_tcp),
19960 		    OID_AUTO,
19961 #ifdef STACKALIAS
19962 		    __XSTRING(STACKALIAS),
19963 #else
19964 		    __XSTRING(STACKNAME),
19965 #endif
19966 		    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
19967 		    "");
19968 		if (rack_sysctl_root == NULL) {
19969 			printf("Failed to add sysctl node\n");
19970 			err = EFAULT;
19971 			goto free_uma;
19972 		}
19973 		rack_init_sysctls();
19974 		num_stacks = nitems(rack_stack_names);
19975 		err = register_tcp_functions_as_names(&__tcp_rack, M_WAITOK,
19976 		    rack_stack_names, &num_stacks);
19977 		if (err) {
19978 			printf("Failed to register %s stack name for "
19979 			    "%s module\n", rack_stack_names[num_stacks],
19980 			    __XSTRING(MODNAME));
19981 			sysctl_ctx_free(&rack_sysctl_ctx);
19982 free_uma:
19983 			uma_zdestroy(rack_zone);
19984 			uma_zdestroy(rack_pcb_zone);
19985 			rack_counter_destroy();
19986 			printf("Failed to register rack module -- err:%d\n", err);
19987 			return (err);
19988 		}
19989 		tcp_lro_reg_mbufq();
19990 		rack_mod_inited = true;
19991 		break;
19992 	case MOD_QUIESCE:
19993 		err = deregister_tcp_functions(&__tcp_rack, true, false);
19994 		break;
19995 	case MOD_UNLOAD:
19996 		err = deregister_tcp_functions(&__tcp_rack, false, true);
19997 		if (err == EBUSY)
19998 			break;
19999 		if (rack_mod_inited) {
20000 			uma_zdestroy(rack_zone);
20001 			uma_zdestroy(rack_pcb_zone);
20002 			sysctl_ctx_free(&rack_sysctl_ctx);
20003 			rack_counter_destroy();
20004 			rack_mod_inited = false;
20005 		}
20006 		tcp_lro_dereg_mbufq();
20007 		err = 0;
20008 		break;
20009 	default:
20010 		return (EOPNOTSUPP);
20011 	}
20012 	return (err);
20013 }
20014 
20015 static moduledata_t tcp_rack = {
20016 	.name = __XSTRING(MODNAME),
20017 	.evhand = tcp_addrack,
20018 	.priv = 0
20019 };
20020 
20021 MODULE_VERSION(MODNAME, 1);
20022 DECLARE_MODULE(MODNAME, tcp_rack, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
20023 MODULE_DEPEND(MODNAME, tcphpts, 1, 1, 1);
20024