xref: /freebsd/sys/netinet/tcp_stacks/rack.c (revision e7437ae907c89bf85a99c5cbb7ddd194a1ff1354) 
1 /*-
2  * Copyright (c) 2016-2020 Netflix, Inc.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  *
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include "opt_inet.h"
31 #include "opt_inet6.h"
32 #include "opt_ipsec.h"
33 #include "opt_tcpdebug.h"
34 #include "opt_ratelimit.h"
35 #include "opt_kern_tls.h"
36 #include <sys/param.h>
37 #include <sys/arb.h>
38 #include <sys/module.h>
39 #include <sys/kernel.h>
40 #ifdef TCP_HHOOK
41 #include <sys/hhook.h>
42 #endif
43 #include <sys/lock.h>
44 #include <sys/malloc.h>
45 #include <sys/lock.h>
46 #include <sys/mutex.h>
47 #include <sys/mbuf.h>
48 #include <sys/proc.h>		/* for proc0 declaration */
49 #include <sys/socket.h>
50 #include <sys/socketvar.h>
51 #include <sys/sysctl.h>
52 #include <sys/systm.h>
53 #ifdef STATS
54 #include <sys/qmath.h>
55 #include <sys/tree.h>
56 #include <sys/stats.h> /* Must come after qmath.h and tree.h */
57 #else
58 #include <sys/tree.h>
59 #endif
60 #include <sys/refcount.h>
61 #include <sys/queue.h>
62 #include <sys/tim_filter.h>
63 #include <sys/smp.h>
64 #include <sys/kthread.h>
65 #include <sys/kern_prefetch.h>
66 #include <sys/protosw.h>
67 #ifdef TCP_ACCOUNTING
68 #include <sys/sched.h>
69 #include <machine/cpu.h>
70 #endif
71 #include <vm/uma.h>
72 
73 #include <net/route.h>
74 #include <net/route/nhop.h>
75 #include <net/vnet.h>
76 
77 #define TCPSTATES		/* for logging */
78 
79 #include <netinet/in.h>
80 #include <netinet/in_kdtrace.h>
81 #include <netinet/in_pcb.h>
82 #include <netinet/ip.h>
83 #include <netinet/ip_icmp.h>	/* required for icmp_var.h */
84 #include <netinet/icmp_var.h>	/* for ICMP_BANDLIM */
85 #include <netinet/ip_var.h>
86 #include <netinet/ip6.h>
87 #include <netinet6/in6_pcb.h>
88 #include <netinet6/ip6_var.h>
89 #include <netinet/tcp.h>
90 #define	TCPOUTFLAGS
91 #include <netinet/tcp_fsm.h>
92 #include <netinet/tcp_log_buf.h>
93 #include <netinet/tcp_seq.h>
94 #include <netinet/tcp_timer.h>
95 #include <netinet/tcp_var.h>
96 #include <netinet/tcp_syncache.h>
97 #include <netinet/tcp_hpts.h>
98 #include <netinet/tcp_ratelimit.h>
99 #include <netinet/tcp_accounting.h>
100 #include <netinet/tcpip.h>
101 #include <netinet/cc/cc.h>
102 #include <netinet/cc/cc_newreno.h>
103 #include <netinet/tcp_fastopen.h>
104 #include <netinet/tcp_lro.h>
105 #ifdef NETFLIX_SHARED_CWND
106 #include <netinet/tcp_shared_cwnd.h>
107 #endif
108 #ifdef TCPDEBUG
109 #include <netinet/tcp_debug.h>
110 #endif				/* TCPDEBUG */
111 #ifdef TCP_OFFLOAD
112 #include <netinet/tcp_offload.h>
113 #endif
114 #ifdef INET6
115 #include <netinet6/tcp6_var.h>
116 #endif
117 #include <netinet/tcp_ecn.h>
118 
119 #include <netipsec/ipsec_support.h>
120 
121 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
122 #include <netipsec/ipsec.h>
123 #include <netipsec/ipsec6.h>
124 #endif				/* IPSEC */
125 
126 #include <netinet/udp.h>
127 #include <netinet/udp_var.h>
128 #include <machine/in_cksum.h>
129 
130 #ifdef MAC
131 #include <security/mac/mac_framework.h>
132 #endif
133 #include "sack_filter.h"
134 #include "tcp_rack.h"
135 #include "rack_bbr_common.h"
136 
137 uma_zone_t rack_zone;
138 uma_zone_t rack_pcb_zone;
139 
140 #ifndef TICKS2SBT
141 #define	TICKS2SBT(__t)	(tick_sbt * ((sbintime_t)(__t)))
142 #endif
143 
144 VNET_DECLARE(uint32_t, newreno_beta);
145 VNET_DECLARE(uint32_t, newreno_beta_ecn);
146 #define V_newreno_beta VNET(newreno_beta)
147 #define V_newreno_beta_ecn VNET(newreno_beta_ecn)
148 
149 
150 MALLOC_DEFINE(M_TCPFSB, "tcp_fsb", "TCP fast send block");
151 MALLOC_DEFINE(M_TCPDO, "tcp_do", "TCP deferred options");
152 
153 struct sysctl_ctx_list rack_sysctl_ctx;
154 struct sysctl_oid *rack_sysctl_root;
155 
156 #define CUM_ACKED 1
157 #define SACKED 2
158 
159 /*
160  * The RACK module incorporates a number of
161  * TCP ideas that have been put out into the IETF
162  * over the last few years:
163  * - Matt Mathis's Rate Halving which slowly drops
164  *    the congestion window so that the ack clock can
165  *    be maintained during a recovery.
166  * - Yuchung Cheng's RACK TCP (for which its named) that
167  *    will stop us using the number of dup acks and instead
168  *    use time as the gage of when we retransmit.
169  * - Reorder Detection of RFC4737 and the Tail-Loss probe draft
170  *    of Dukkipati et.al.
171  * RACK depends on SACK, so if an endpoint arrives that
172  * cannot do SACK the state machine below will shuttle the
173  * connection back to using the "default" TCP stack that is
174  * in FreeBSD.
175  *
176  * To implement RACK the original TCP stack was first decomposed
177  * into a functional state machine with individual states
178  * for each of the possible TCP connection states. The do_segment
179  * functions role in life is to mandate the connection supports SACK
180  * initially and then assure that the RACK state matches the conenction
181  * state before calling the states do_segment function. Each
182  * state is simplified due to the fact that the original do_segment
183  * has been decomposed and we *know* what state we are in (no
184  * switches on the state) and all tests for SACK are gone. This
185  * greatly simplifies what each state does.
186  *
187  * TCP output is also over-written with a new version since it
188  * must maintain the new rack scoreboard.
189  *
190  */
191 static int32_t rack_tlp_thresh = 1;
192 static int32_t rack_tlp_limit = 2;	/* No more than 2 TLPs w-out new data */
193 static int32_t rack_tlp_use_greater = 1;
194 static int32_t rack_reorder_thresh = 2;
195 static int32_t rack_reorder_fade = 60000000;	/* 0 - never fade, def 60,000,000
196 						 * - 60 seconds */
197 static uint8_t rack_req_measurements = 1;
198 /* Attack threshold detections */
199 static uint32_t rack_highest_sack_thresh_seen = 0;
200 static uint32_t rack_highest_move_thresh_seen = 0;
201 static int32_t rack_enable_hw_pacing = 0; /* Due to CCSP keep it off by default */
202 static int32_t rack_hw_pace_extra_slots = 2;	/* 2 extra MSS time betweens */
203 static int32_t rack_hw_rate_caps = 1; /* 1; */
204 static int32_t rack_hw_rate_min = 0; /* 1500000;*/
205 static int32_t rack_hw_rate_to_low = 0; /* 1200000; */
206 static int32_t rack_hw_up_only = 1;
207 static int32_t rack_stats_gets_ms_rtt = 1;
208 static int32_t rack_prr_addbackmax = 2;
209 static int32_t rack_do_hystart = 0;
210 static int32_t rack_apply_rtt_with_reduced_conf = 0;
211 
212 static int32_t rack_pkt_delay = 1000;
213 static int32_t rack_send_a_lot_in_prr = 1;
214 static int32_t rack_min_to = 1000;	/* Number of microsecond  min timeout */
215 static int32_t rack_verbose_logging = 0;
216 static int32_t rack_ignore_data_after_close = 1;
217 static int32_t rack_enable_shared_cwnd = 1;
218 static int32_t rack_use_cmp_acks = 1;
219 static int32_t rack_use_fsb = 1;
220 static int32_t rack_use_rfo = 1;
221 static int32_t rack_use_rsm_rfo = 1;
222 static int32_t rack_max_abc_post_recovery = 2;
223 static int32_t rack_client_low_buf = 0;
224 static int32_t rack_dsack_std_based = 0x3;	/* bit field bit 1 sets rc_rack_tmr_std_based and bit 2 sets rc_rack_use_dsack */
225 #ifdef TCP_ACCOUNTING
226 static int32_t rack_tcp_accounting = 0;
227 #endif
228 static int32_t rack_limits_scwnd = 1;
229 static int32_t rack_enable_mqueue_for_nonpaced = 0;
230 static int32_t rack_disable_prr = 0;
231 static int32_t use_rack_rr = 1;
232 static int32_t rack_non_rxt_use_cr = 0; /* does a non-rxt in recovery use the configured rate (ss/ca)? */
233 static int32_t rack_persist_min = 250000;	/* 250usec */
234 static int32_t rack_persist_max = 2000000;	/* 2 Second in usec's */
235 static int32_t rack_sack_not_required = 1;	/* set to one to allow non-sack to use rack */
236 static int32_t rack_default_init_window = 0;	/* Use system default */
237 static int32_t rack_limit_time_with_srtt = 0;
238 static int32_t rack_autosndbuf_inc = 20;	/* In percentage form */
239 static int32_t rack_enobuf_hw_boost_mult = 2;	/* How many times the hw rate we boost slot using time_between */
240 static int32_t rack_enobuf_hw_max = 12000;	/* 12 ms in usecs */
241 static int32_t rack_enobuf_hw_min = 10000;	/* 10 ms in usecs */
242 static int32_t rack_hw_rwnd_factor = 2;		/* How many max_segs the rwnd must be before we hold off sending */
243 
244 /*
245  * Currently regular tcp has a rto_min of 30ms
246  * the backoff goes 12 times so that ends up
247  * being a total of 122.850 seconds before a
248  * connection is killed.
249  */
250 static uint32_t rack_def_data_window = 20;
251 static uint32_t rack_goal_bdp = 2;
252 static uint32_t rack_min_srtts = 1;
253 static uint32_t rack_min_measure_usec = 0;
254 static int32_t rack_tlp_min = 10000;	/* 10ms */
255 static int32_t rack_rto_min = 30000;	/* 30,000 usec same as main freebsd */
256 static int32_t rack_rto_max = 4000000;	/* 4 seconds in usec's */
257 static const int32_t rack_free_cache = 2;
258 static int32_t rack_hptsi_segments = 40;
259 static int32_t rack_rate_sample_method = USE_RTT_LOW;
260 static int32_t rack_pace_every_seg = 0;
261 static int32_t rack_delayed_ack_time = 40000;	/* 40ms in usecs */
262 static int32_t rack_slot_reduction = 4;
263 static int32_t rack_wma_divisor = 8;		/* For WMA calculation */
264 static int32_t rack_cwnd_block_ends_measure = 0;
265 static int32_t rack_rwnd_block_ends_measure = 0;
266 static int32_t rack_def_profile = 0;
267 
268 static int32_t rack_lower_cwnd_at_tlp = 0;
269 static int32_t rack_limited_retran = 0;
270 static int32_t rack_always_send_oldest = 0;
271 static int32_t rack_tlp_threshold_use = TLP_USE_TWO_ONE;
272 
273 static uint16_t rack_per_of_gp_ss = 250;	/* 250 % slow-start */
274 static uint16_t rack_per_of_gp_ca = 200;	/* 200 % congestion-avoidance */
275 static uint16_t rack_per_of_gp_rec = 200;	/* 200 % of bw */
276 
277 /* Probertt */
278 static uint16_t rack_per_of_gp_probertt = 60;	/* 60% of bw */
279 static uint16_t rack_per_of_gp_lowthresh = 40;	/* 40% is bottom */
280 static uint16_t rack_per_of_gp_probertt_reduce = 10; /* 10% reduction */
281 static uint16_t rack_atexit_prtt_hbp = 130;	/* Clamp to 130% on exit prtt if highly buffered path */
282 static uint16_t rack_atexit_prtt = 130;	/* Clamp to 100% on exit prtt if non highly buffered path */
283 
284 static uint32_t rack_max_drain_wait = 2;	/* How man gp srtt's before we give up draining */
285 static uint32_t rack_must_drain = 1;		/* How many GP srtt's we *must* wait */
286 static uint32_t rack_probertt_use_min_rtt_entry = 1;	/* Use the min to calculate the goal else gp_srtt */
287 static uint32_t rack_probertt_use_min_rtt_exit = 0;
288 static uint32_t rack_probe_rtt_sets_cwnd = 0;
289 static uint32_t rack_probe_rtt_safety_val = 2000000;	/* No more than 2 sec in probe-rtt */
290 static uint32_t rack_time_between_probertt = 9600000;	/* 9.6 sec in usecs */
291 static uint32_t rack_probertt_gpsrtt_cnt_mul = 0;	/* How many srtt periods does probe-rtt last top fraction */
292 static uint32_t rack_probertt_gpsrtt_cnt_div = 0;	/* How many srtt periods does probe-rtt last bottom fraction */
293 static uint32_t rack_min_probertt_hold = 40000;		/* Equal to delayed ack time */
294 static uint32_t rack_probertt_filter_life = 10000000;
295 static uint32_t rack_probertt_lower_within = 10;
296 static uint32_t rack_min_rtt_movement = 250000;	/* Must move at least 250ms (in microseconds)  to count as a lowering */
297 static int32_t rack_pace_one_seg = 0;		/* Shall we pace for less than 1.4Meg 1MSS at a time */
298 static int32_t rack_probertt_clear_is = 1;
299 static int32_t rack_max_drain_hbp = 1;		/* Extra drain times gpsrtt for highly buffered paths */
300 static int32_t rack_hbp_thresh = 3;		/* what is the divisor max_rtt/min_rtt to decided a hbp */
301 
302 /* Part of pacing */
303 static int32_t rack_max_per_above = 30;		/* When we go to increment stop if above 100+this% */
304 
305 /* Timely information */
306 /* Combine these two gives the range of 'no change' to bw */
307 /* ie the up/down provide the upper and lower bound */
308 static int32_t rack_gp_per_bw_mul_up = 2;	/* 2% */
309 static int32_t rack_gp_per_bw_mul_down = 4;	/* 4% */
310 static int32_t rack_gp_rtt_maxmul = 3;		/* 3 x maxmin */
311 static int32_t rack_gp_rtt_minmul = 1;		/* minrtt + (minrtt/mindiv) is lower rtt */
312 static int32_t rack_gp_rtt_mindiv = 4;		/* minrtt + (minrtt * minmul/mindiv) is lower rtt */
313 static int32_t rack_gp_decrease_per = 20;	/* 20% decrease in multiplier */
314 static int32_t rack_gp_increase_per = 2;	/* 2% increase in multiplier */
315 static int32_t rack_per_lower_bound = 50;	/* Don't allow to drop below this multiplier */
316 static int32_t rack_per_upper_bound_ss = 0;	/* Don't allow SS to grow above this */
317 static int32_t rack_per_upper_bound_ca = 0;	/* Don't allow CA to grow above this */
318 static int32_t rack_do_dyn_mul = 0;		/* Are the rack gp multipliers dynamic */
319 static int32_t rack_gp_no_rec_chg = 1;		/* Prohibit recovery from reducing it's multiplier */
320 static int32_t rack_timely_dec_clear = 6;	/* Do we clear decrement count at a value (6)? */
321 static int32_t rack_timely_max_push_rise = 3;	/* One round of pushing */
322 static int32_t rack_timely_max_push_drop = 3;	/* Three round of pushing */
323 static int32_t rack_timely_min_segs = 4;	/* 4 segment minimum */
324 static int32_t rack_use_max_for_nobackoff = 0;
325 static int32_t rack_timely_int_timely_only = 0;	/* do interim timely's only use the timely algo (no b/w changes)? */
326 static int32_t rack_timely_no_stopping = 0;
327 static int32_t rack_down_raise_thresh = 100;
328 static int32_t rack_req_segs = 1;
329 static uint64_t rack_bw_rate_cap = 0;
330 static uint32_t rack_trace_point_config = 0;
331 static uint32_t rack_trace_point_bb_mode = 4;
332 static int32_t rack_trace_point_count = 0;
333 
334 
335 /* Weird delayed ack mode */
336 static int32_t rack_use_imac_dack = 0;
337 /* Rack specific counters */
338 counter_u64_t rack_saw_enobuf;
339 counter_u64_t rack_saw_enobuf_hw;
340 counter_u64_t rack_saw_enetunreach;
341 counter_u64_t rack_persists_sends;
342 counter_u64_t rack_persists_acks;
343 counter_u64_t rack_persists_loss;
344 counter_u64_t rack_persists_lost_ends;
345 #ifdef INVARIANTS
346 counter_u64_t rack_adjust_map_bw;
347 #endif
348 /* Tail loss probe counters */
349 counter_u64_t rack_tlp_tot;
350 counter_u64_t rack_tlp_newdata;
351 counter_u64_t rack_tlp_retran;
352 counter_u64_t rack_tlp_retran_bytes;
353 counter_u64_t rack_to_tot;
354 counter_u64_t rack_hot_alloc;
355 counter_u64_t rack_to_alloc;
356 counter_u64_t rack_to_alloc_hard;
357 counter_u64_t rack_to_alloc_emerg;
358 counter_u64_t rack_to_alloc_limited;
359 counter_u64_t rack_alloc_limited_conns;
360 counter_u64_t rack_split_limited;
361 
362 counter_u64_t rack_multi_single_eq;
363 counter_u64_t rack_proc_non_comp_ack;
364 
365 counter_u64_t rack_fto_send;
366 counter_u64_t rack_fto_rsm_send;
367 counter_u64_t rack_nfto_resend;
368 counter_u64_t rack_non_fto_send;
369 counter_u64_t rack_extended_rfo;
370 
371 counter_u64_t rack_sack_proc_all;
372 counter_u64_t rack_sack_proc_short;
373 counter_u64_t rack_sack_proc_restart;
374 counter_u64_t rack_sack_attacks_detected;
375 counter_u64_t rack_sack_attacks_reversed;
376 counter_u64_t rack_sack_used_next_merge;
377 counter_u64_t rack_sack_splits;
378 counter_u64_t rack_sack_used_prev_merge;
379 counter_u64_t rack_sack_skipped_acked;
380 counter_u64_t rack_ack_total;
381 counter_u64_t rack_express_sack;
382 counter_u64_t rack_sack_total;
383 counter_u64_t rack_move_none;
384 counter_u64_t rack_move_some;
385 
386 counter_u64_t rack_input_idle_reduces;
387 counter_u64_t rack_collapsed_win;
388 counter_u64_t rack_try_scwnd;
389 counter_u64_t rack_hw_pace_init_fail;
390 counter_u64_t rack_hw_pace_lost;
391 
392 counter_u64_t rack_out_size[TCP_MSS_ACCT_SIZE];
393 counter_u64_t rack_opts_arry[RACK_OPTS_SIZE];
394 
395 
396 #define	RACK_REXMTVAL(tp) max(rack_rto_min, ((tp)->t_srtt + ((tp)->t_rttvar << 2)))
397 
398 #define	RACK_TCPT_RANGESET(tv, value, tvmin, tvmax, slop) do {	\
399 	(tv) = (value) + slop;	 \
400 	if ((u_long)(tv) < (u_long)(tvmin)) \
401 		(tv) = (tvmin); \
402 	if ((u_long)(tv) > (u_long)(tvmax)) \
403 		(tv) = (tvmax); \
404 } while (0)
405 
406 static void
407 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick,  int event, int line);
408 
409 static int
410 rack_process_ack(struct mbuf *m, struct tcphdr *th,
411     struct socket *so, struct tcpcb *tp, struct tcpopt *to,
412     uint32_t tiwin, int32_t tlen, int32_t * ofia, int32_t thflags, int32_t * ret_val);
413 static int
414 rack_process_data(struct mbuf *m, struct tcphdr *th,
415     struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
416     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt);
417 static void
418 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack,
419    uint32_t th_ack, uint16_t nsegs, uint16_t type, int32_t recovery);
420 static struct rack_sendmap *rack_alloc(struct tcp_rack *rack);
421 static struct rack_sendmap *rack_alloc_limit(struct tcp_rack *rack,
422     uint8_t limit_type);
423 static struct rack_sendmap *
424 rack_check_recovery_mode(struct tcpcb *tp,
425     uint32_t tsused);
426 static void
427 rack_cong_signal(struct tcpcb *tp,
428 		 uint32_t type, uint32_t ack, int );
429 static void rack_counter_destroy(void);
430 static int
431 rack_ctloutput(struct inpcb *inp, struct sockopt *sopt);
432 static int32_t rack_ctor(void *mem, int32_t size, void *arg, int32_t how);
433 static void
434 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line, uint64_t *fill_override);
435 static void
436 rack_do_segment(struct mbuf *m, struct tcphdr *th,
437     struct socket *so, struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
438     uint8_t iptos);
439 static void rack_dtor(void *mem, int32_t size, void *arg);
440 static void
441 rack_log_alt_to_to_cancel(struct tcp_rack *rack,
442     uint32_t flex1, uint32_t flex2,
443     uint32_t flex3, uint32_t flex4,
444     uint32_t flex5, uint32_t flex6,
445     uint16_t flex7, uint8_t mod);
446 
447 static void
448 rack_log_pacing_delay_calc(struct tcp_rack *rack, uint32_t len, uint32_t slot,
449    uint64_t bw_est, uint64_t bw, uint64_t len_time, int method, int line,
450    struct rack_sendmap *rsm, uint8_t quality);
451 static struct rack_sendmap *
452 rack_find_high_nonack(struct tcp_rack *rack,
453     struct rack_sendmap *rsm);
454 static struct rack_sendmap *rack_find_lowest_rsm(struct tcp_rack *rack);
455 static void rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm);
456 static void rack_fini(struct tcpcb *tp, int32_t tcb_is_purged);
457 static int rack_get_sockopt(struct inpcb *inp, struct sockopt *sopt);
458 static void
459 rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
460 			    tcp_seq th_ack, int line, uint8_t quality);
461 static uint32_t
462 rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss);
463 static int32_t rack_handoff_ok(struct tcpcb *tp);
464 static int32_t rack_init(struct tcpcb *tp);
465 static void rack_init_sysctls(void);
466 static void
467 rack_log_ack(struct tcpcb *tp, struct tcpopt *to,
468     struct tcphdr *th, int entered_rec, int dup_ack_struck);
469 static void
470 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
471     uint32_t seq_out, uint16_t th_flags, int32_t err, uint64_t ts,
472     struct rack_sendmap *hintrsm, uint16_t add_flags, struct mbuf *s_mb, uint32_t s_moff, int hw_tls);
473 
474 static void
475 rack_log_sack_passed(struct tcpcb *tp, struct tcp_rack *rack,
476     struct rack_sendmap *rsm);
477 static void rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm);
478 static int32_t rack_output(struct tcpcb *tp);
479 
480 static uint32_t
481 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack,
482     struct sackblk *sack, struct tcpopt *to, struct rack_sendmap **prsm,
483     uint32_t cts, int *moved_two);
484 static void rack_post_recovery(struct tcpcb *tp, uint32_t th_seq);
485 static void rack_remxt_tmr(struct tcpcb *tp);
486 static int rack_set_sockopt(struct inpcb *inp, struct sockopt *sopt);
487 static void rack_set_state(struct tcpcb *tp, struct tcp_rack *rack);
488 static int32_t rack_stopall(struct tcpcb *tp);
489 static void
490 rack_timer_activate(struct tcpcb *tp, uint32_t timer_type,
491     uint32_t delta);
492 static int32_t rack_timer_active(struct tcpcb *tp, uint32_t timer_type);
493 static void rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line);
494 static void rack_timer_stop(struct tcpcb *tp, uint32_t timer_type);
495 static uint32_t
496 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
497     struct rack_sendmap *rsm, uint64_t ts, int32_t * lenp, uint16_t add_flag);
498 static void
499 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
500     struct rack_sendmap *rsm, uint64_t ts, uint16_t add_flag);
501 static int
502 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
503     struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack);
504 static int32_t tcp_addrack(module_t mod, int32_t type, void *data);
505 static int
506 rack_do_close_wait(struct mbuf *m, struct tcphdr *th,
507     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
508     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
509 static int
510 rack_do_closing(struct mbuf *m, struct tcphdr *th,
511     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
512     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
513 static int
514 rack_do_established(struct mbuf *m, struct tcphdr *th,
515     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
516     int32_t tlen, uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos);
517 static int
518 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th,
519     struct socket *so, struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen,
520     int32_t tlen, uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos);
521 static int
522 rack_do_fin_wait_1(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_fin_wait_2(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_lastack(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_syn_recv(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 thflags, int32_t nxt_pkt, uint8_t iptos);
537 static int
538 rack_do_syn_sent(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 struct rack_sendmap *
542 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack,
543     uint32_t tsused);
544 static void tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt,
545     uint32_t len, uint32_t us_tim, int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt);
546 static void
547      tcp_rack_partialack(struct tcpcb *tp);
548 static int
549 rack_set_profile(struct tcp_rack *rack, int prof);
550 static void
551 rack_apply_deferred_options(struct tcp_rack *rack);
552 
553 int32_t rack_clear_counter=0;
554 
555 static inline void
556 rack_trace_point(struct tcp_rack *rack, int num)
557 {
558 	if (((rack_trace_point_config == num)  ||
559 	     (rack_trace_point_config = 0xffffffff)) &&
560 	    (rack_trace_point_bb_mode != 0) &&
561 	    (rack_trace_point_count > 0) &&
562 	    (rack->rc_tp->t_logstate == 0)) {
563 		int res;
564 		res = atomic_fetchadd_int(&rack_trace_point_count, -1);
565 		if (res > 0) {
566 			rack->rc_tp->t_logstate = rack_trace_point_bb_mode;
567 		} else {
568 			/* Loss a race assure its zero now */
569 			rack_trace_point_count = 0;
570 		}
571 	}
572 }
573 
574 static void
575 rack_set_cc_pacing(struct tcp_rack *rack)
576 {
577 	struct sockopt sopt;
578 	struct cc_newreno_opts opt;
579 	struct newreno old, *ptr;
580 	struct tcpcb *tp;
581 	int error;
582 
583 	if (rack->rc_pacing_cc_set)
584 		return;
585 
586 	tp = rack->rc_tp;
587 	if (tp->cc_algo == NULL) {
588 		/* Tcb is leaving */
589 		return;
590 	}
591 	rack->rc_pacing_cc_set = 1;
592 	if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0) {
593 		/* Not new-reno we can't play games with beta! */
594 		goto out;
595 	}
596 	ptr = ((struct newreno *)tp->ccv->cc_data);
597 	if (CC_ALGO(tp)->ctl_output == NULL)  {
598 		/* Huh, why does new_reno no longer have a set function? */
599 		goto out;
600 	}
601 	if (ptr == NULL) {
602 		/* Just the default values */
603 		old.beta = V_newreno_beta_ecn;
604 		old.beta_ecn = V_newreno_beta_ecn;
605 		old.newreno_flags = 0;
606 	} else {
607 		old.beta = ptr->beta;
608 		old.beta_ecn = ptr->beta_ecn;
609 		old.newreno_flags = ptr->newreno_flags;
610 	}
611 	sopt.sopt_valsize = sizeof(struct cc_newreno_opts);
612 	sopt.sopt_dir = SOPT_SET;
613 	opt.name = CC_NEWRENO_BETA;
614 	opt.val = rack->r_ctl.rc_saved_beta.beta;
615 	error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
616 	if (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_ENABLED;
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 		goto out;
629 	}
630 	/* Save off the original values for restoral */
631 	memcpy(&rack->r_ctl.rc_saved_beta, &old, sizeof(struct newreno));
632 out:
633 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
634 		union tcp_log_stackspecific log;
635 		struct timeval tv;
636 
637 		ptr = ((struct newreno *)tp->ccv->cc_data);
638 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
639 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
640 		if (ptr) {
641 			log.u_bbr.flex1 = ptr->beta;
642 			log.u_bbr.flex2 = ptr->beta_ecn;
643 			log.u_bbr.flex3 = ptr->newreno_flags;
644 		}
645 		log.u_bbr.flex4 = rack->r_ctl.rc_saved_beta.beta;
646 		log.u_bbr.flex5 = rack->r_ctl.rc_saved_beta.beta_ecn;
647 		log.u_bbr.flex6 = rack->r_ctl.rc_saved_beta.newreno_flags;
648 		log.u_bbr.flex7 = rack->gp_ready;
649 		log.u_bbr.flex7 <<= 1;
650 		log.u_bbr.flex7 |= rack->use_fixed_rate;
651 		log.u_bbr.flex7 <<= 1;
652 		log.u_bbr.flex7 |= rack->rc_pacing_cc_set;
653 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
654 		log.u_bbr.flex8 = 3;
655 		tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, error,
656 			       0, &log, false, NULL, NULL, 0, &tv);
657 	}
658 }
659 
660 static void
661 rack_undo_cc_pacing(struct tcp_rack *rack)
662 {
663 	struct newreno old, *ptr;
664 	struct tcpcb *tp;
665 
666 	if (rack->rc_pacing_cc_set == 0)
667 		return;
668 	tp = rack->rc_tp;
669 	rack->rc_pacing_cc_set = 0;
670 	if (tp->cc_algo == NULL)
671 		/* Tcb is leaving */
672 		return;
673 	if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0) {
674 		/* Not new-reno nothing to do! */
675 		return;
676 	}
677 	ptr = ((struct newreno *)tp->ccv->cc_data);
678 	if (ptr == NULL) {
679 		/*
680 		 * This happens at rack_fini() if the
681 		 * cc module gets freed on us. In that
682 		 * case we loose our "new" settings but
683 		 * thats ok, since the tcb is going away anyway.
684 		 */
685 		return;
686 	}
687 	/* Grab out our set values */
688 	memcpy(&old, ptr, sizeof(struct newreno));
689 	/* Copy back in the original values */
690 	memcpy(ptr, &rack->r_ctl.rc_saved_beta, sizeof(struct newreno));
691 	/* Now save back the values we had set in (for when pacing is restored) */
692 	memcpy(&rack->r_ctl.rc_saved_beta, &old, sizeof(struct newreno));
693 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
694 		union tcp_log_stackspecific log;
695 		struct timeval tv;
696 
697 		ptr = ((struct newreno *)tp->ccv->cc_data);
698 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
699 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
700 		log.u_bbr.flex1 = ptr->beta;
701 		log.u_bbr.flex2 = ptr->beta_ecn;
702 		log.u_bbr.flex3 = ptr->newreno_flags;
703 		log.u_bbr.flex4 = rack->r_ctl.rc_saved_beta.beta;
704 		log.u_bbr.flex5 = rack->r_ctl.rc_saved_beta.beta_ecn;
705 		log.u_bbr.flex6 = rack->r_ctl.rc_saved_beta.newreno_flags;
706 		log.u_bbr.flex7 = rack->gp_ready;
707 		log.u_bbr.flex7 <<= 1;
708 		log.u_bbr.flex7 |= rack->use_fixed_rate;
709 		log.u_bbr.flex7 <<= 1;
710 		log.u_bbr.flex7 |= rack->rc_pacing_cc_set;
711 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
712 		log.u_bbr.flex8 = 4;
713 		tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
714 			       0, &log, false, NULL, NULL, 0, &tv);
715 	}
716 }
717 
718 #ifdef NETFLIX_PEAKRATE
719 static inline void
720 rack_update_peakrate_thr(struct tcpcb *tp)
721 {
722 	/* Keep in mind that t_maxpeakrate is in B/s. */
723 	uint64_t peak;
724 	peak = uqmax((tp->t_maxseg * 2),
725 		     (((uint64_t)tp->t_maxpeakrate * (uint64_t)(tp->t_srtt)) / (uint64_t)HPTS_USEC_IN_SEC));
726 	tp->t_peakrate_thr = (uint32_t)uqmin(peak, UINT32_MAX);
727 }
728 #endif
729 
730 static int
731 sysctl_rack_clear(SYSCTL_HANDLER_ARGS)
732 {
733 	uint32_t stat;
734 	int32_t error;
735 
736 	error = SYSCTL_OUT(req, &rack_clear_counter, sizeof(uint32_t));
737 	if (error || req->newptr == NULL)
738 		return error;
739 
740 	error = SYSCTL_IN(req, &stat, sizeof(uint32_t));
741 	if (error)
742 		return (error);
743 	if (stat == 1) {
744 #ifdef INVARIANTS
745 		printf("Clearing RACK counters\n");
746 #endif
747 		counter_u64_zero(rack_tlp_tot);
748 		counter_u64_zero(rack_tlp_newdata);
749 		counter_u64_zero(rack_tlp_retran);
750 		counter_u64_zero(rack_tlp_retran_bytes);
751 		counter_u64_zero(rack_to_tot);
752 		counter_u64_zero(rack_saw_enobuf);
753 		counter_u64_zero(rack_saw_enobuf_hw);
754 		counter_u64_zero(rack_saw_enetunreach);
755 		counter_u64_zero(rack_persists_sends);
756 		counter_u64_zero(rack_persists_acks);
757 		counter_u64_zero(rack_persists_loss);
758 		counter_u64_zero(rack_persists_lost_ends);
759 #ifdef INVARIANTS
760 		counter_u64_zero(rack_adjust_map_bw);
761 #endif
762 		counter_u64_zero(rack_to_alloc_hard);
763 		counter_u64_zero(rack_to_alloc_emerg);
764 		counter_u64_zero(rack_sack_proc_all);
765 		counter_u64_zero(rack_fto_send);
766 		counter_u64_zero(rack_fto_rsm_send);
767 		counter_u64_zero(rack_extended_rfo);
768 		counter_u64_zero(rack_hw_pace_init_fail);
769 		counter_u64_zero(rack_hw_pace_lost);
770 		counter_u64_zero(rack_non_fto_send);
771 		counter_u64_zero(rack_nfto_resend);
772 		counter_u64_zero(rack_sack_proc_short);
773 		counter_u64_zero(rack_sack_proc_restart);
774 		counter_u64_zero(rack_to_alloc);
775 		counter_u64_zero(rack_to_alloc_limited);
776 		counter_u64_zero(rack_alloc_limited_conns);
777 		counter_u64_zero(rack_split_limited);
778 		counter_u64_zero(rack_multi_single_eq);
779 		counter_u64_zero(rack_proc_non_comp_ack);
780 		counter_u64_zero(rack_sack_attacks_detected);
781 		counter_u64_zero(rack_sack_attacks_reversed);
782 		counter_u64_zero(rack_sack_used_next_merge);
783 		counter_u64_zero(rack_sack_used_prev_merge);
784 		counter_u64_zero(rack_sack_splits);
785 		counter_u64_zero(rack_sack_skipped_acked);
786 		counter_u64_zero(rack_ack_total);
787 		counter_u64_zero(rack_express_sack);
788 		counter_u64_zero(rack_sack_total);
789 		counter_u64_zero(rack_move_none);
790 		counter_u64_zero(rack_move_some);
791 		counter_u64_zero(rack_try_scwnd);
792 		counter_u64_zero(rack_collapsed_win);
793 	}
794 	rack_clear_counter = 0;
795 	return (0);
796 }
797 
798 static void
799 rack_init_sysctls(void)
800 {
801 	struct sysctl_oid *rack_counters;
802 	struct sysctl_oid *rack_attack;
803 	struct sysctl_oid *rack_pacing;
804 	struct sysctl_oid *rack_timely;
805 	struct sysctl_oid *rack_timers;
806 	struct sysctl_oid *rack_tlp;
807 	struct sysctl_oid *rack_misc;
808 	struct sysctl_oid *rack_features;
809 	struct sysctl_oid *rack_measure;
810 	struct sysctl_oid *rack_probertt;
811 	struct sysctl_oid *rack_hw_pacing;
812 	struct sysctl_oid *rack_tracepoint;
813 
814 	rack_attack = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
815 	    SYSCTL_CHILDREN(rack_sysctl_root),
816 	    OID_AUTO,
817 	    "sack_attack",
818 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
819 	    "Rack Sack Attack Counters and Controls");
820 	rack_counters = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
821 	    SYSCTL_CHILDREN(rack_sysctl_root),
822 	    OID_AUTO,
823 	    "stats",
824 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
825 	    "Rack Counters");
826 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
827 	    SYSCTL_CHILDREN(rack_sysctl_root),
828 	    OID_AUTO, "rate_sample_method", CTLFLAG_RW,
829 	    &rack_rate_sample_method , USE_RTT_LOW,
830 	    "What method should we use for rate sampling 0=high, 1=low ");
831 	/* Probe rtt related controls */
832 	rack_probertt = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
833 	    SYSCTL_CHILDREN(rack_sysctl_root),
834 	    OID_AUTO,
835 	    "probertt",
836 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
837 	    "ProbeRTT related Controls");
838 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
839 	    SYSCTL_CHILDREN(rack_probertt),
840 	    OID_AUTO, "exit_per_hpb", CTLFLAG_RW,
841 	    &rack_atexit_prtt_hbp, 130,
842 	    "What percentage above goodput do we clamp CA/SS to at exit on high-BDP path 110%");
843 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
844 	    SYSCTL_CHILDREN(rack_probertt),
845 	    OID_AUTO, "exit_per_nonhpb", CTLFLAG_RW,
846 	    &rack_atexit_prtt, 130,
847 	    "What percentage above goodput do we clamp CA/SS to at exit on a non high-BDP path 100%");
848 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
849 	    SYSCTL_CHILDREN(rack_probertt),
850 	    OID_AUTO, "gp_per_mul", CTLFLAG_RW,
851 	    &rack_per_of_gp_probertt, 60,
852 	    "What percentage of goodput do we pace at in probertt");
853 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
854 	    SYSCTL_CHILDREN(rack_probertt),
855 	    OID_AUTO, "gp_per_reduce", CTLFLAG_RW,
856 	    &rack_per_of_gp_probertt_reduce, 10,
857 	    "What percentage of goodput do we reduce every gp_srtt");
858 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
859 	    SYSCTL_CHILDREN(rack_probertt),
860 	    OID_AUTO, "gp_per_low", CTLFLAG_RW,
861 	    &rack_per_of_gp_lowthresh, 40,
862 	    "What percentage of goodput do we allow the multiplier to fall to");
863 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
864 	    SYSCTL_CHILDREN(rack_probertt),
865 	    OID_AUTO, "time_between", CTLFLAG_RW,
866 	    & rack_time_between_probertt, 96000000,
867 	    "How many useconds between the lowest rtt falling must past before we enter probertt");
868 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
869 	    SYSCTL_CHILDREN(rack_probertt),
870 	    OID_AUTO, "safety", CTLFLAG_RW,
871 	    &rack_probe_rtt_safety_val, 2000000,
872 	    "If not zero, provides a maximum usecond that you can stay in probertt (2sec = 2000000)");
873 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
874 	    SYSCTL_CHILDREN(rack_probertt),
875 	    OID_AUTO, "sets_cwnd", CTLFLAG_RW,
876 	    &rack_probe_rtt_sets_cwnd, 0,
877 	    "Do we set the cwnd too (if always_lower is on)");
878 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
879 	    SYSCTL_CHILDREN(rack_probertt),
880 	    OID_AUTO, "maxdrainsrtts", CTLFLAG_RW,
881 	    &rack_max_drain_wait, 2,
882 	    "Maximum number of gp_srtt's to hold in drain waiting for flight to reach goal");
883 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
884 	    SYSCTL_CHILDREN(rack_probertt),
885 	    OID_AUTO, "mustdrainsrtts", CTLFLAG_RW,
886 	    &rack_must_drain, 1,
887 	    "We must drain this many gp_srtt's waiting for flight to reach goal");
888 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
889 	    SYSCTL_CHILDREN(rack_probertt),
890 	    OID_AUTO, "goal_use_min_entry", CTLFLAG_RW,
891 	    &rack_probertt_use_min_rtt_entry, 1,
892 	    "Should we use the min-rtt to calculate the goal rtt (else gp_srtt) at entry");
893 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
894 	    SYSCTL_CHILDREN(rack_probertt),
895 	    OID_AUTO, "goal_use_min_exit", CTLFLAG_RW,
896 	    &rack_probertt_use_min_rtt_exit, 0,
897 	    "How to set cwnd at exit, 0 - dynamic, 1 - use min-rtt, 2 - use curgprtt, 3 - entry gp-rtt");
898 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
899 	    SYSCTL_CHILDREN(rack_probertt),
900 	    OID_AUTO, "length_div", CTLFLAG_RW,
901 	    &rack_probertt_gpsrtt_cnt_div, 0,
902 	    "How many recent goodput srtt periods plus hold tim does probertt last (bottom of fraction)");
903 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
904 	    SYSCTL_CHILDREN(rack_probertt),
905 	    OID_AUTO, "length_mul", CTLFLAG_RW,
906 	    &rack_probertt_gpsrtt_cnt_mul, 0,
907 	    "How many recent goodput srtt periods plus hold tim does probertt last (top of fraction)");
908 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
909 	    SYSCTL_CHILDREN(rack_probertt),
910 	    OID_AUTO, "holdtim_at_target", CTLFLAG_RW,
911 	    &rack_min_probertt_hold, 200000,
912 	    "What is the minimum time we hold probertt at target");
913 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
914 	    SYSCTL_CHILDREN(rack_probertt),
915 	    OID_AUTO, "filter_life", CTLFLAG_RW,
916 	    &rack_probertt_filter_life, 10000000,
917 	    "What is the time for the filters life in useconds");
918 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
919 	    SYSCTL_CHILDREN(rack_probertt),
920 	    OID_AUTO, "lower_within", CTLFLAG_RW,
921 	    &rack_probertt_lower_within, 10,
922 	    "If the rtt goes lower within this percentage of the time, go into probe-rtt");
923 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
924 	    SYSCTL_CHILDREN(rack_probertt),
925 	    OID_AUTO, "must_move", CTLFLAG_RW,
926 	    &rack_min_rtt_movement, 250,
927 	    "How much is the minimum movement in rtt to count as a drop for probertt purposes");
928 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
929 	    SYSCTL_CHILDREN(rack_probertt),
930 	    OID_AUTO, "clear_is_cnts", CTLFLAG_RW,
931 	    &rack_probertt_clear_is, 1,
932 	    "Do we clear I/S counts on exiting probe-rtt");
933 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
934 	    SYSCTL_CHILDREN(rack_probertt),
935 	    OID_AUTO, "hbp_extra_drain", CTLFLAG_RW,
936 	    &rack_max_drain_hbp, 1,
937 	    "How many extra drain gpsrtt's do we get in highly buffered paths");
938 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
939 	    SYSCTL_CHILDREN(rack_probertt),
940 	    OID_AUTO, "hbp_threshold", CTLFLAG_RW,
941 	    &rack_hbp_thresh, 3,
942 	    "We are highly buffered if min_rtt_seen / max_rtt_seen > this-threshold");
943 
944 	rack_tracepoint = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
945 	    SYSCTL_CHILDREN(rack_sysctl_root),
946 	    OID_AUTO,
947 	    "tp",
948 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
949 	    "Rack tracepoint facility");
950 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
951 	    SYSCTL_CHILDREN(rack_tracepoint),
952 	    OID_AUTO, "number", CTLFLAG_RW,
953 	    &rack_trace_point_config, 0,
954 	    "What is the trace point number to activate (0=none, 0xffffffff = all)?");
955 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
956 	    SYSCTL_CHILDREN(rack_tracepoint),
957 	    OID_AUTO, "bbmode", CTLFLAG_RW,
958 	    &rack_trace_point_bb_mode, 4,
959 	    "What is BB logging mode that is activated?");
960 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
961 	    SYSCTL_CHILDREN(rack_tracepoint),
962 	    OID_AUTO, "count", CTLFLAG_RW,
963 	    &rack_trace_point_count, 0,
964 	    "How many connections will have BB logging turned on that hit the tracepoint?");
965 	/* Pacing related sysctls */
966 	rack_pacing = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
967 	    SYSCTL_CHILDREN(rack_sysctl_root),
968 	    OID_AUTO,
969 	    "pacing",
970 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
971 	    "Pacing related Controls");
972 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
973 	    SYSCTL_CHILDREN(rack_pacing),
974 	    OID_AUTO, "max_pace_over", CTLFLAG_RW,
975 	    &rack_max_per_above, 30,
976 	    "What is the maximum allowable percentage that we can pace above (so 30 = 130% of our goal)");
977 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
978 	    SYSCTL_CHILDREN(rack_pacing),
979 	    OID_AUTO, "pace_to_one", CTLFLAG_RW,
980 	    &rack_pace_one_seg, 0,
981 	    "Do we allow low b/w pacing of 1MSS instead of two");
982 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
983 	    SYSCTL_CHILDREN(rack_pacing),
984 	    OID_AUTO, "limit_wsrtt", CTLFLAG_RW,
985 	    &rack_limit_time_with_srtt, 0,
986 	    "Do we limit pacing time based on srtt");
987 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
988 	    SYSCTL_CHILDREN(rack_pacing),
989 	    OID_AUTO, "init_win", CTLFLAG_RW,
990 	    &rack_default_init_window, 0,
991 	    "Do we have a rack initial window 0 = system default");
992 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
993 	    SYSCTL_CHILDREN(rack_pacing),
994 	    OID_AUTO, "gp_per_ss", CTLFLAG_RW,
995 	    &rack_per_of_gp_ss, 250,
996 	    "If non zero, what percentage of goodput to pace at in slow start");
997 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
998 	    SYSCTL_CHILDREN(rack_pacing),
999 	    OID_AUTO, "gp_per_ca", CTLFLAG_RW,
1000 	    &rack_per_of_gp_ca, 150,
1001 	    "If non zero, what percentage of goodput to pace at in congestion avoidance");
1002 	SYSCTL_ADD_U16(&rack_sysctl_ctx,
1003 	    SYSCTL_CHILDREN(rack_pacing),
1004 	    OID_AUTO, "gp_per_rec", CTLFLAG_RW,
1005 	    &rack_per_of_gp_rec, 200,
1006 	    "If non zero, what percentage of goodput to pace at in recovery");
1007 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1008 	    SYSCTL_CHILDREN(rack_pacing),
1009 	    OID_AUTO, "pace_max_seg", CTLFLAG_RW,
1010 	    &rack_hptsi_segments, 40,
1011 	    "What size is the max for TSO segments in pacing and burst mitigation");
1012 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1013 	    SYSCTL_CHILDREN(rack_pacing),
1014 	    OID_AUTO, "burst_reduces", CTLFLAG_RW,
1015 	    &rack_slot_reduction, 4,
1016 	    "When doing only burst mitigation what is the reduce divisor");
1017 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1018 	    SYSCTL_CHILDREN(rack_sysctl_root),
1019 	    OID_AUTO, "use_pacing", CTLFLAG_RW,
1020 	    &rack_pace_every_seg, 0,
1021 	    "If set we use pacing, if clear we use only the original burst mitigation");
1022 	SYSCTL_ADD_U64(&rack_sysctl_ctx,
1023 	    SYSCTL_CHILDREN(rack_pacing),
1024 	    OID_AUTO, "rate_cap", CTLFLAG_RW,
1025 	    &rack_bw_rate_cap, 0,
1026 	    "If set we apply this value to the absolute rate cap used by pacing");
1027 	SYSCTL_ADD_U8(&rack_sysctl_ctx,
1028 	    SYSCTL_CHILDREN(rack_sysctl_root),
1029 	    OID_AUTO, "req_measure_cnt", CTLFLAG_RW,
1030 	    &rack_req_measurements, 1,
1031 	    "If doing dynamic pacing, how many measurements must be in before we start pacing?");
1032 	/* Hardware pacing */
1033 	rack_hw_pacing = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1034 	    SYSCTL_CHILDREN(rack_sysctl_root),
1035 	    OID_AUTO,
1036 	    "hdwr_pacing",
1037 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1038 	    "Pacing related Controls");
1039 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1040 	    SYSCTL_CHILDREN(rack_hw_pacing),
1041 	    OID_AUTO, "rwnd_factor", CTLFLAG_RW,
1042 	    &rack_hw_rwnd_factor, 2,
1043 	    "How many times does snd_wnd need to be bigger than pace_max_seg so we will hold off and get more acks?");
1044 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1045 	    SYSCTL_CHILDREN(rack_hw_pacing),
1046 	    OID_AUTO, "pace_enobuf_mult", CTLFLAG_RW,
1047 	    &rack_enobuf_hw_boost_mult, 2,
1048 	    "By how many time_betweens should we boost the pacing time if we see a ENOBUFS?");
1049 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1050 	    SYSCTL_CHILDREN(rack_hw_pacing),
1051 	    OID_AUTO, "pace_enobuf_max", CTLFLAG_RW,
1052 	    &rack_enobuf_hw_max, 2,
1053 	    "What is the max boost the pacing time if we see a ENOBUFS?");
1054 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1055 	    SYSCTL_CHILDREN(rack_hw_pacing),
1056 	    OID_AUTO, "pace_enobuf_min", CTLFLAG_RW,
1057 	    &rack_enobuf_hw_min, 2,
1058 	    "What is the min boost the pacing time if we see a ENOBUFS?");
1059 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1060 	    SYSCTL_CHILDREN(rack_hw_pacing),
1061 	    OID_AUTO, "enable", CTLFLAG_RW,
1062 	    &rack_enable_hw_pacing, 0,
1063 	    "Should RACK attempt to use hw pacing?");
1064 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1065 	    SYSCTL_CHILDREN(rack_hw_pacing),
1066 	    OID_AUTO, "rate_cap", CTLFLAG_RW,
1067 	    &rack_hw_rate_caps, 1,
1068 	    "Does the highest hardware pacing rate cap the rate we will send at??");
1069 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1070 	    SYSCTL_CHILDREN(rack_hw_pacing),
1071 	    OID_AUTO, "rate_min", CTLFLAG_RW,
1072 	    &rack_hw_rate_min, 0,
1073 	    "Do we need a minimum estimate of this many bytes per second in order to engage hw pacing?");
1074 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1075 	    SYSCTL_CHILDREN(rack_hw_pacing),
1076 	    OID_AUTO, "rate_to_low", CTLFLAG_RW,
1077 	    &rack_hw_rate_to_low, 0,
1078 	    "If we fall below this rate, dis-engage hw pacing?");
1079 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1080 	    SYSCTL_CHILDREN(rack_hw_pacing),
1081 	    OID_AUTO, "up_only", CTLFLAG_RW,
1082 	    &rack_hw_up_only, 1,
1083 	    "Do we allow hw pacing to lower the rate selected?");
1084 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1085 	    SYSCTL_CHILDREN(rack_hw_pacing),
1086 	    OID_AUTO, "extra_mss_precise", CTLFLAG_RW,
1087 	    &rack_hw_pace_extra_slots, 2,
1088 	    "If the rates between software and hardware match precisely how many extra time_betweens do we get?");
1089 	rack_timely = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1090 	    SYSCTL_CHILDREN(rack_sysctl_root),
1091 	    OID_AUTO,
1092 	    "timely",
1093 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1094 	    "Rack Timely RTT Controls");
1095 	/* Timely based GP dynmics */
1096 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1097 	    SYSCTL_CHILDREN(rack_timely),
1098 	    OID_AUTO, "upper", CTLFLAG_RW,
1099 	    &rack_gp_per_bw_mul_up, 2,
1100 	    "Rack timely upper range for equal b/w (in percentage)");
1101 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1102 	    SYSCTL_CHILDREN(rack_timely),
1103 	    OID_AUTO, "lower", CTLFLAG_RW,
1104 	    &rack_gp_per_bw_mul_down, 4,
1105 	    "Rack timely lower range for equal b/w (in percentage)");
1106 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1107 	    SYSCTL_CHILDREN(rack_timely),
1108 	    OID_AUTO, "rtt_max_mul", CTLFLAG_RW,
1109 	    &rack_gp_rtt_maxmul, 3,
1110 	    "Rack timely multiplier of lowest rtt for rtt_max");
1111 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1112 	    SYSCTL_CHILDREN(rack_timely),
1113 	    OID_AUTO, "rtt_min_div", CTLFLAG_RW,
1114 	    &rack_gp_rtt_mindiv, 4,
1115 	    "Rack timely divisor used for rtt + (rtt * mul/divisor) for check for lower rtt");
1116 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1117 	    SYSCTL_CHILDREN(rack_timely),
1118 	    OID_AUTO, "rtt_min_mul", CTLFLAG_RW,
1119 	    &rack_gp_rtt_minmul, 1,
1120 	    "Rack timely multiplier used for rtt + (rtt * mul/divisor) for check for lower rtt");
1121 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1122 	    SYSCTL_CHILDREN(rack_timely),
1123 	    OID_AUTO, "decrease", CTLFLAG_RW,
1124 	    &rack_gp_decrease_per, 20,
1125 	    "Rack timely decrease percentage of our GP multiplication factor");
1126 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1127 	    SYSCTL_CHILDREN(rack_timely),
1128 	    OID_AUTO, "increase", CTLFLAG_RW,
1129 	    &rack_gp_increase_per, 2,
1130 	    "Rack timely increase perentage of our GP multiplication factor");
1131 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1132 	    SYSCTL_CHILDREN(rack_timely),
1133 	    OID_AUTO, "lowerbound", CTLFLAG_RW,
1134 	    &rack_per_lower_bound, 50,
1135 	    "Rack timely lowest percentage we allow GP multiplier to fall to");
1136 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1137 	    SYSCTL_CHILDREN(rack_timely),
1138 	    OID_AUTO, "upperboundss", CTLFLAG_RW,
1139 	    &rack_per_upper_bound_ss, 0,
1140 	    "Rack timely highest percentage we allow GP multiplier in SS to raise to (0 is no upperbound)");
1141 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1142 	    SYSCTL_CHILDREN(rack_timely),
1143 	    OID_AUTO, "upperboundca", CTLFLAG_RW,
1144 	    &rack_per_upper_bound_ca, 0,
1145 	    "Rack timely highest percentage we allow GP multiplier to CA raise to (0 is no upperbound)");
1146 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1147 	    SYSCTL_CHILDREN(rack_timely),
1148 	    OID_AUTO, "dynamicgp", CTLFLAG_RW,
1149 	    &rack_do_dyn_mul, 0,
1150 	    "Rack timely do we enable dynmaic timely goodput by default");
1151 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1152 	    SYSCTL_CHILDREN(rack_timely),
1153 	    OID_AUTO, "no_rec_red", CTLFLAG_RW,
1154 	    &rack_gp_no_rec_chg, 1,
1155 	    "Rack timely do we prohibit the recovery multiplier from being lowered");
1156 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1157 	    SYSCTL_CHILDREN(rack_timely),
1158 	    OID_AUTO, "red_clear_cnt", CTLFLAG_RW,
1159 	    &rack_timely_dec_clear, 6,
1160 	    "Rack timely what threshold do we count to before another boost during b/w decent");
1161 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1162 	    SYSCTL_CHILDREN(rack_timely),
1163 	    OID_AUTO, "max_push_rise", CTLFLAG_RW,
1164 	    &rack_timely_max_push_rise, 3,
1165 	    "Rack timely how many times do we push up with b/w increase");
1166 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1167 	    SYSCTL_CHILDREN(rack_timely),
1168 	    OID_AUTO, "max_push_drop", CTLFLAG_RW,
1169 	    &rack_timely_max_push_drop, 3,
1170 	    "Rack timely how many times do we push back on b/w decent");
1171 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1172 	    SYSCTL_CHILDREN(rack_timely),
1173 	    OID_AUTO, "min_segs", CTLFLAG_RW,
1174 	    &rack_timely_min_segs, 4,
1175 	    "Rack timely when setting the cwnd what is the min num segments");
1176 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1177 	    SYSCTL_CHILDREN(rack_timely),
1178 	    OID_AUTO, "noback_max", CTLFLAG_RW,
1179 	    &rack_use_max_for_nobackoff, 0,
1180 	    "Rack timely when deciding if to backoff on a loss, do we use under max rtt else min");
1181 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1182 	    SYSCTL_CHILDREN(rack_timely),
1183 	    OID_AUTO, "interim_timely_only", CTLFLAG_RW,
1184 	    &rack_timely_int_timely_only, 0,
1185 	    "Rack timely when doing interim timely's do we only do timely (no b/w consideration)");
1186 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1187 	    SYSCTL_CHILDREN(rack_timely),
1188 	    OID_AUTO, "nonstop", CTLFLAG_RW,
1189 	    &rack_timely_no_stopping, 0,
1190 	    "Rack timely don't stop increase");
1191 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1192 	    SYSCTL_CHILDREN(rack_timely),
1193 	    OID_AUTO, "dec_raise_thresh", CTLFLAG_RW,
1194 	    &rack_down_raise_thresh, 100,
1195 	    "If the CA or SS is below this threshold raise on the first 3 b/w lowers (0=always)");
1196 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1197 	    SYSCTL_CHILDREN(rack_timely),
1198 	    OID_AUTO, "bottom_drag_segs", CTLFLAG_RW,
1199 	    &rack_req_segs, 1,
1200 	    "Bottom dragging if not these many segments outstanding and room");
1201 
1202 	/* TLP and Rack related parameters */
1203 	rack_tlp = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1204 	    SYSCTL_CHILDREN(rack_sysctl_root),
1205 	    OID_AUTO,
1206 	    "tlp",
1207 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1208 	    "TLP and Rack related Controls");
1209 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1210 	    SYSCTL_CHILDREN(rack_tlp),
1211 	    OID_AUTO, "use_rrr", CTLFLAG_RW,
1212 	    &use_rack_rr, 1,
1213 	    "Do we use Rack Rapid Recovery");
1214 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1215 	    SYSCTL_CHILDREN(rack_tlp),
1216 	    OID_AUTO, "post_rec_labc", CTLFLAG_RW,
1217 	    &rack_max_abc_post_recovery, 2,
1218 	    "Since we do early recovery, do we override the l_abc to a value, if so what?");
1219 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1220 	    SYSCTL_CHILDREN(rack_tlp),
1221 	    OID_AUTO, "nonrxt_use_cr", CTLFLAG_RW,
1222 	    &rack_non_rxt_use_cr, 0,
1223 	    "Do we use ss/ca rate if in recovery we are transmitting a new data chunk");
1224 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1225 	    SYSCTL_CHILDREN(rack_tlp),
1226 	    OID_AUTO, "tlpmethod", CTLFLAG_RW,
1227 	    &rack_tlp_threshold_use, TLP_USE_TWO_ONE,
1228 	    "What method do we do for TLP time calc 0=no-de-ack-comp, 1=ID, 2=2.1, 3=2.2");
1229 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1230 	    SYSCTL_CHILDREN(rack_tlp),
1231 	    OID_AUTO, "limit", CTLFLAG_RW,
1232 	    &rack_tlp_limit, 2,
1233 	    "How many TLP's can be sent without sending new data");
1234 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1235 	    SYSCTL_CHILDREN(rack_tlp),
1236 	    OID_AUTO, "use_greater", CTLFLAG_RW,
1237 	    &rack_tlp_use_greater, 1,
1238 	    "Should we use the rack_rtt time if its greater than srtt");
1239 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1240 	    SYSCTL_CHILDREN(rack_tlp),
1241 	    OID_AUTO, "tlpminto", CTLFLAG_RW,
1242 	    &rack_tlp_min, 10000,
1243 	    "TLP minimum timeout per the specification (in microseconds)");
1244 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1245 	    SYSCTL_CHILDREN(rack_tlp),
1246 	    OID_AUTO, "send_oldest", CTLFLAG_RW,
1247 	    &rack_always_send_oldest, 0,
1248 	    "Should we always send the oldest TLP and RACK-TLP");
1249 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1250 	    SYSCTL_CHILDREN(rack_tlp),
1251 	    OID_AUTO, "rack_tlimit", CTLFLAG_RW,
1252 	    &rack_limited_retran, 0,
1253 	    "How many times can a rack timeout drive out sends");
1254 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1255 	    SYSCTL_CHILDREN(rack_tlp),
1256 	    OID_AUTO, "tlp_cwnd_flag", CTLFLAG_RW,
1257 	    &rack_lower_cwnd_at_tlp, 0,
1258 	    "When a TLP completes a retran should we enter recovery");
1259 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1260 	    SYSCTL_CHILDREN(rack_tlp),
1261 	    OID_AUTO, "reorder_thresh", CTLFLAG_RW,
1262 	    &rack_reorder_thresh, 2,
1263 	    "What factor for rack will be added when seeing reordering (shift right)");
1264 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1265 	    SYSCTL_CHILDREN(rack_tlp),
1266 	    OID_AUTO, "rtt_tlp_thresh", CTLFLAG_RW,
1267 	    &rack_tlp_thresh, 1,
1268 	    "What divisor for TLP rtt/retran will be added (1=rtt, 2=1/2 rtt etc)");
1269 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1270 	    SYSCTL_CHILDREN(rack_tlp),
1271 	    OID_AUTO, "reorder_fade", CTLFLAG_RW,
1272 	    &rack_reorder_fade, 60000000,
1273 	    "Does reorder detection fade, if so how many microseconds (0 means never)");
1274 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1275 	    SYSCTL_CHILDREN(rack_tlp),
1276 	    OID_AUTO, "pktdelay", CTLFLAG_RW,
1277 	    &rack_pkt_delay, 1000,
1278 	    "Extra RACK time (in microseconds) besides reordering thresh");
1279 
1280 	/* Timer related controls */
1281 	rack_timers = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1282 	    SYSCTL_CHILDREN(rack_sysctl_root),
1283 	    OID_AUTO,
1284 	    "timers",
1285 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1286 	    "Timer related controls");
1287 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1288 	    SYSCTL_CHILDREN(rack_timers),
1289 	    OID_AUTO, "persmin", CTLFLAG_RW,
1290 	    &rack_persist_min, 250000,
1291 	    "What is the minimum time in microseconds between persists");
1292 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1293 	    SYSCTL_CHILDREN(rack_timers),
1294 	    OID_AUTO, "persmax", CTLFLAG_RW,
1295 	    &rack_persist_max, 2000000,
1296 	    "What is the largest delay in microseconds between persists");
1297 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1298 	    SYSCTL_CHILDREN(rack_timers),
1299 	    OID_AUTO, "delayed_ack", CTLFLAG_RW,
1300 	    &rack_delayed_ack_time, 40000,
1301 	    "Delayed ack time (40ms in microseconds)");
1302 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1303 	    SYSCTL_CHILDREN(rack_timers),
1304 	    OID_AUTO, "minrto", CTLFLAG_RW,
1305 	    &rack_rto_min, 30000,
1306 	    "Minimum RTO in microseconds -- set with caution below 1000 due to TLP");
1307 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1308 	    SYSCTL_CHILDREN(rack_timers),
1309 	    OID_AUTO, "maxrto", CTLFLAG_RW,
1310 	    &rack_rto_max, 4000000,
1311 	    "Maximum RTO in microseconds -- should be at least as large as min_rto");
1312 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1313 	    SYSCTL_CHILDREN(rack_timers),
1314 	    OID_AUTO, "minto", CTLFLAG_RW,
1315 	    &rack_min_to, 1000,
1316 	    "Minimum rack timeout in microseconds");
1317 	/* Measure controls */
1318 	rack_measure = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1319 	    SYSCTL_CHILDREN(rack_sysctl_root),
1320 	    OID_AUTO,
1321 	    "measure",
1322 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1323 	    "Measure related controls");
1324 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1325 	    SYSCTL_CHILDREN(rack_measure),
1326 	    OID_AUTO, "wma_divisor", CTLFLAG_RW,
1327 	    &rack_wma_divisor, 8,
1328 	    "When doing b/w calculation what is the  divisor for the WMA");
1329 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1330 	    SYSCTL_CHILDREN(rack_measure),
1331 	    OID_AUTO, "end_cwnd", CTLFLAG_RW,
1332 	    &rack_cwnd_block_ends_measure, 0,
1333 	    "Does a cwnd just-return end the measurement window (app limited)");
1334 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1335 	    SYSCTL_CHILDREN(rack_measure),
1336 	    OID_AUTO, "end_rwnd", CTLFLAG_RW,
1337 	    &rack_rwnd_block_ends_measure, 0,
1338 	    "Does an rwnd just-return end the measurement window (app limited -- not persists)");
1339 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1340 	    SYSCTL_CHILDREN(rack_measure),
1341 	    OID_AUTO, "min_target", CTLFLAG_RW,
1342 	    &rack_def_data_window, 20,
1343 	    "What is the minimum target window (in mss) for a GP measurements");
1344 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1345 	    SYSCTL_CHILDREN(rack_measure),
1346 	    OID_AUTO, "goal_bdp", CTLFLAG_RW,
1347 	    &rack_goal_bdp, 2,
1348 	    "What is the goal BDP to measure");
1349 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1350 	    SYSCTL_CHILDREN(rack_measure),
1351 	    OID_AUTO, "min_srtts", CTLFLAG_RW,
1352 	    &rack_min_srtts, 1,
1353 	    "What is the goal BDP to measure");
1354 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1355 	    SYSCTL_CHILDREN(rack_measure),
1356 	    OID_AUTO, "min_measure_tim", CTLFLAG_RW,
1357 	    &rack_min_measure_usec, 0,
1358 	    "What is the Minimum time time for a measurement if 0, this is off");
1359 	/* Features */
1360 	rack_features = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1361 	    SYSCTL_CHILDREN(rack_sysctl_root),
1362 	    OID_AUTO,
1363 	    "features",
1364 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1365 	    "Feature controls");
1366 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1367 	    SYSCTL_CHILDREN(rack_features),
1368 	    OID_AUTO, "cmpack", CTLFLAG_RW,
1369 	    &rack_use_cmp_acks, 1,
1370 	    "Should RACK have LRO send compressed acks");
1371 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1372 	    SYSCTL_CHILDREN(rack_features),
1373 	    OID_AUTO, "fsb", CTLFLAG_RW,
1374 	    &rack_use_fsb, 1,
1375 	    "Should RACK use the fast send block?");
1376 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1377 	    SYSCTL_CHILDREN(rack_features),
1378 	    OID_AUTO, "rfo", CTLFLAG_RW,
1379 	    &rack_use_rfo, 1,
1380 	    "Should RACK use rack_fast_output()?");
1381 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1382 	    SYSCTL_CHILDREN(rack_features),
1383 	    OID_AUTO, "rsmrfo", CTLFLAG_RW,
1384 	    &rack_use_rsm_rfo, 1,
1385 	    "Should RACK use rack_fast_rsm_output()?");
1386 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1387 	    SYSCTL_CHILDREN(rack_features),
1388 	    OID_AUTO, "non_paced_lro_queue", CTLFLAG_RW,
1389 	    &rack_enable_mqueue_for_nonpaced, 0,
1390 	    "Should RACK use mbuf queuing for non-paced connections");
1391 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1392 	    SYSCTL_CHILDREN(rack_features),
1393 	    OID_AUTO, "hystartplusplus", CTLFLAG_RW,
1394 	    &rack_do_hystart, 0,
1395 	    "Should RACK enable HyStart++ on connections?");
1396 	/* Misc rack controls */
1397 	rack_misc = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
1398 	    SYSCTL_CHILDREN(rack_sysctl_root),
1399 	    OID_AUTO,
1400 	    "misc",
1401 	    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1402 	    "Misc related controls");
1403 #ifdef TCP_ACCOUNTING
1404 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1405 	    SYSCTL_CHILDREN(rack_misc),
1406 	    OID_AUTO, "tcp_acct", CTLFLAG_RW,
1407 	    &rack_tcp_accounting, 0,
1408 	    "Should we turn on TCP accounting for all rack sessions?");
1409 #endif
1410 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1411 	    SYSCTL_CHILDREN(rack_misc),
1412 	    OID_AUTO, "apply_rtt_with_low_conf", CTLFLAG_RW,
1413 	    &rack_apply_rtt_with_reduced_conf, 0,
1414 	    "When a persist or keep-alive probe is not answered do we calculate rtt on subsequent answers?");
1415 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1416 	    SYSCTL_CHILDREN(rack_misc),
1417 	    OID_AUTO, "rack_dsack_ctl", CTLFLAG_RW,
1418 	    &rack_dsack_std_based, 3,
1419 	    "How do we process dsack with respect to rack timers, bit field, 3 is standards based?");
1420 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1421 	    SYSCTL_CHILDREN(rack_misc),
1422 	    OID_AUTO, "prr_addback_max", CTLFLAG_RW,
1423 	    &rack_prr_addbackmax, 2,
1424 	    "What is the maximum number of MSS we allow to be added back if prr can't send all its data?");
1425 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1426 	    SYSCTL_CHILDREN(rack_misc),
1427 	    OID_AUTO, "stats_gets_ms", CTLFLAG_RW,
1428 	    &rack_stats_gets_ms_rtt, 1,
1429 	    "What do we feed the stats framework (1 = ms_rtt, 0 = us_rtt, 2 = ms_rtt from hdwr, > 2 usec rtt from hdwr)?");
1430 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1431 	    SYSCTL_CHILDREN(rack_misc),
1432 	    OID_AUTO, "clientlowbuf", CTLFLAG_RW,
1433 	    &rack_client_low_buf, 0,
1434 	    "Client low buffer level (below this we are more aggressive in DGP exiting recovery (0 = off)?");
1435 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1436 	    SYSCTL_CHILDREN(rack_misc),
1437 	    OID_AUTO, "defprofile", CTLFLAG_RW,
1438 	    &rack_def_profile, 0,
1439 	    "Should RACK use a default profile (0=no, num == profile num)?");
1440 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1441 	    SYSCTL_CHILDREN(rack_misc),
1442 	    OID_AUTO, "shared_cwnd", CTLFLAG_RW,
1443 	    &rack_enable_shared_cwnd, 1,
1444 	    "Should RACK try to use the shared cwnd on connections where allowed");
1445 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1446 	    SYSCTL_CHILDREN(rack_misc),
1447 	    OID_AUTO, "limits_on_scwnd", CTLFLAG_RW,
1448 	    &rack_limits_scwnd, 1,
1449 	    "Should RACK place low end time limits on the shared cwnd feature");
1450 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1451 	    SYSCTL_CHILDREN(rack_misc),
1452 	    OID_AUTO, "iMac_dack", CTLFLAG_RW,
1453 	    &rack_use_imac_dack, 0,
1454 	    "Should RACK try to emulate iMac delayed ack");
1455 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1456 	    SYSCTL_CHILDREN(rack_misc),
1457 	    OID_AUTO, "no_prr", CTLFLAG_RW,
1458 	    &rack_disable_prr, 0,
1459 	    "Should RACK not use prr and only pace (must have pacing on)");
1460 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1461 	    SYSCTL_CHILDREN(rack_misc),
1462 	    OID_AUTO, "bb_verbose", CTLFLAG_RW,
1463 	    &rack_verbose_logging, 0,
1464 	    "Should RACK black box logging be verbose");
1465 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1466 	    SYSCTL_CHILDREN(rack_misc),
1467 	    OID_AUTO, "data_after_close", CTLFLAG_RW,
1468 	    &rack_ignore_data_after_close, 1,
1469 	    "Do we hold off sending a RST until all pending data is ack'd");
1470 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1471 	    SYSCTL_CHILDREN(rack_misc),
1472 	    OID_AUTO, "no_sack_needed", CTLFLAG_RW,
1473 	    &rack_sack_not_required, 1,
1474 	    "Do we allow rack to run on connections not supporting SACK");
1475 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1476 	    SYSCTL_CHILDREN(rack_misc),
1477 	    OID_AUTO, "prr_sendalot", CTLFLAG_RW,
1478 	    &rack_send_a_lot_in_prr, 1,
1479 	    "Send a lot in prr");
1480 	SYSCTL_ADD_S32(&rack_sysctl_ctx,
1481 	    SYSCTL_CHILDREN(rack_misc),
1482 	    OID_AUTO, "autoscale", CTLFLAG_RW,
1483 	    &rack_autosndbuf_inc, 20,
1484 	    "What percentage should rack scale up its snd buffer by?");
1485 	/* Sack Attacker detection stuff */
1486 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1487 	    SYSCTL_CHILDREN(rack_attack),
1488 	    OID_AUTO, "detect_highsackratio", CTLFLAG_RW,
1489 	    &rack_highest_sack_thresh_seen, 0,
1490 	    "Highest sack to ack ratio seen");
1491 	SYSCTL_ADD_U32(&rack_sysctl_ctx,
1492 	    SYSCTL_CHILDREN(rack_attack),
1493 	    OID_AUTO, "detect_highmoveratio", CTLFLAG_RW,
1494 	    &rack_highest_move_thresh_seen, 0,
1495 	    "Highest move to non-move ratio seen");
1496 	rack_ack_total = counter_u64_alloc(M_WAITOK);
1497 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1498 	    SYSCTL_CHILDREN(rack_attack),
1499 	    OID_AUTO, "acktotal", CTLFLAG_RD,
1500 	    &rack_ack_total,
1501 	    "Total number of Ack's");
1502 	rack_express_sack = counter_u64_alloc(M_WAITOK);
1503 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1504 	    SYSCTL_CHILDREN(rack_attack),
1505 	    OID_AUTO, "exp_sacktotal", CTLFLAG_RD,
1506 	    &rack_express_sack,
1507 	    "Total expresss number of Sack's");
1508 	rack_sack_total = counter_u64_alloc(M_WAITOK);
1509 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1510 	    SYSCTL_CHILDREN(rack_attack),
1511 	    OID_AUTO, "sacktotal", CTLFLAG_RD,
1512 	    &rack_sack_total,
1513 	    "Total number of SACKs");
1514 	rack_move_none = counter_u64_alloc(M_WAITOK);
1515 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1516 	    SYSCTL_CHILDREN(rack_attack),
1517 	    OID_AUTO, "move_none", CTLFLAG_RD,
1518 	    &rack_move_none,
1519 	    "Total number of SACK index reuse of positions under threshold");
1520 	rack_move_some = counter_u64_alloc(M_WAITOK);
1521 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1522 	    SYSCTL_CHILDREN(rack_attack),
1523 	    OID_AUTO, "move_some", CTLFLAG_RD,
1524 	    &rack_move_some,
1525 	    "Total number of SACK index reuse of positions over threshold");
1526 	rack_sack_attacks_detected = counter_u64_alloc(M_WAITOK);
1527 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1528 	    SYSCTL_CHILDREN(rack_attack),
1529 	    OID_AUTO, "attacks", CTLFLAG_RD,
1530 	    &rack_sack_attacks_detected,
1531 	    "Total number of SACK attackers that had sack disabled");
1532 	rack_sack_attacks_reversed = counter_u64_alloc(M_WAITOK);
1533 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1534 	    SYSCTL_CHILDREN(rack_attack),
1535 	    OID_AUTO, "reversed", CTLFLAG_RD,
1536 	    &rack_sack_attacks_reversed,
1537 	    "Total number of SACK attackers that were later determined false positive");
1538 	rack_sack_used_next_merge = counter_u64_alloc(M_WAITOK);
1539 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1540 	    SYSCTL_CHILDREN(rack_attack),
1541 	    OID_AUTO, "nextmerge", CTLFLAG_RD,
1542 	    &rack_sack_used_next_merge,
1543 	    "Total number of times we used the next merge");
1544 	rack_sack_used_prev_merge = counter_u64_alloc(M_WAITOK);
1545 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1546 	    SYSCTL_CHILDREN(rack_attack),
1547 	    OID_AUTO, "prevmerge", CTLFLAG_RD,
1548 	    &rack_sack_used_prev_merge,
1549 	    "Total number of times we used the prev merge");
1550 	/* Counters */
1551 	rack_fto_send = counter_u64_alloc(M_WAITOK);
1552 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1553 	    SYSCTL_CHILDREN(rack_counters),
1554 	    OID_AUTO, "fto_send", CTLFLAG_RD,
1555 	    &rack_fto_send, "Total number of rack_fast_output sends");
1556 	rack_fto_rsm_send = counter_u64_alloc(M_WAITOK);
1557 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1558 	    SYSCTL_CHILDREN(rack_counters),
1559 	    OID_AUTO, "fto_rsm_send", CTLFLAG_RD,
1560 	    &rack_fto_rsm_send, "Total number of rack_fast_rsm_output sends");
1561 	rack_nfto_resend = counter_u64_alloc(M_WAITOK);
1562 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1563 	    SYSCTL_CHILDREN(rack_counters),
1564 	    OID_AUTO, "nfto_resend", CTLFLAG_RD,
1565 	    &rack_nfto_resend, "Total number of rack_output retransmissions");
1566 	rack_non_fto_send = counter_u64_alloc(M_WAITOK);
1567 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1568 	    SYSCTL_CHILDREN(rack_counters),
1569 	    OID_AUTO, "nfto_send", CTLFLAG_RD,
1570 	    &rack_non_fto_send, "Total number of rack_output first sends");
1571 	rack_extended_rfo = counter_u64_alloc(M_WAITOK);
1572 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1573 	    SYSCTL_CHILDREN(rack_counters),
1574 	    OID_AUTO, "rfo_extended", CTLFLAG_RD,
1575 	    &rack_extended_rfo, "Total number of times we extended rfo");
1576 
1577 	rack_hw_pace_init_fail = counter_u64_alloc(M_WAITOK);
1578 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1579 	    SYSCTL_CHILDREN(rack_counters),
1580 	    OID_AUTO, "hwpace_init_fail", CTLFLAG_RD,
1581 	    &rack_hw_pace_init_fail, "Total number of times we failed to initialize hw pacing");
1582 	rack_hw_pace_lost = counter_u64_alloc(M_WAITOK);
1583 
1584 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1585 	    SYSCTL_CHILDREN(rack_counters),
1586 	    OID_AUTO, "hwpace_lost", CTLFLAG_RD,
1587 	    &rack_hw_pace_lost, "Total number of times we failed to initialize hw pacing");
1588 	rack_tlp_tot = counter_u64_alloc(M_WAITOK);
1589 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1590 	    SYSCTL_CHILDREN(rack_counters),
1591 	    OID_AUTO, "tlp_to_total", CTLFLAG_RD,
1592 	    &rack_tlp_tot,
1593 	    "Total number of tail loss probe expirations");
1594 	rack_tlp_newdata = counter_u64_alloc(M_WAITOK);
1595 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1596 	    SYSCTL_CHILDREN(rack_counters),
1597 	    OID_AUTO, "tlp_new", CTLFLAG_RD,
1598 	    &rack_tlp_newdata,
1599 	    "Total number of tail loss probe sending new data");
1600 	rack_tlp_retran = counter_u64_alloc(M_WAITOK);
1601 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1602 	    SYSCTL_CHILDREN(rack_counters),
1603 	    OID_AUTO, "tlp_retran", CTLFLAG_RD,
1604 	    &rack_tlp_retran,
1605 	    "Total number of tail loss probe sending retransmitted data");
1606 	rack_tlp_retran_bytes = counter_u64_alloc(M_WAITOK);
1607 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1608 	    SYSCTL_CHILDREN(rack_counters),
1609 	    OID_AUTO, "tlp_retran_bytes", CTLFLAG_RD,
1610 	    &rack_tlp_retran_bytes,
1611 	    "Total bytes of tail loss probe sending retransmitted data");
1612 	rack_to_tot = counter_u64_alloc(M_WAITOK);
1613 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1614 	    SYSCTL_CHILDREN(rack_counters),
1615 	    OID_AUTO, "rack_to_tot", CTLFLAG_RD,
1616 	    &rack_to_tot,
1617 	    "Total number of times the rack to expired");
1618 	rack_saw_enobuf = counter_u64_alloc(M_WAITOK);
1619 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1620 	    SYSCTL_CHILDREN(rack_counters),
1621 	    OID_AUTO, "saw_enobufs", CTLFLAG_RD,
1622 	    &rack_saw_enobuf,
1623 	    "Total number of times a sends returned enobuf for non-hdwr paced connections");
1624 	rack_saw_enobuf_hw = counter_u64_alloc(M_WAITOK);
1625 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1626 	    SYSCTL_CHILDREN(rack_counters),
1627 	    OID_AUTO, "saw_enobufs_hw", CTLFLAG_RD,
1628 	    &rack_saw_enobuf_hw,
1629 	    "Total number of times a send returned enobuf for hdwr paced connections");
1630 	rack_saw_enetunreach = counter_u64_alloc(M_WAITOK);
1631 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1632 	    SYSCTL_CHILDREN(rack_counters),
1633 	    OID_AUTO, "saw_enetunreach", CTLFLAG_RD,
1634 	    &rack_saw_enetunreach,
1635 	    "Total number of times a send received a enetunreachable");
1636 	rack_hot_alloc = counter_u64_alloc(M_WAITOK);
1637 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1638 	    SYSCTL_CHILDREN(rack_counters),
1639 	    OID_AUTO, "alloc_hot", CTLFLAG_RD,
1640 	    &rack_hot_alloc,
1641 	    "Total allocations from the top of our list");
1642 	rack_to_alloc = counter_u64_alloc(M_WAITOK);
1643 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1644 	    SYSCTL_CHILDREN(rack_counters),
1645 	    OID_AUTO, "allocs", CTLFLAG_RD,
1646 	    &rack_to_alloc,
1647 	    "Total allocations of tracking structures");
1648 	rack_to_alloc_hard = counter_u64_alloc(M_WAITOK);
1649 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1650 	    SYSCTL_CHILDREN(rack_counters),
1651 	    OID_AUTO, "allochard", CTLFLAG_RD,
1652 	    &rack_to_alloc_hard,
1653 	    "Total allocations done with sleeping the hard way");
1654 	rack_to_alloc_emerg = counter_u64_alloc(M_WAITOK);
1655 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1656 	    SYSCTL_CHILDREN(rack_counters),
1657 	    OID_AUTO, "allocemerg", CTLFLAG_RD,
1658 	    &rack_to_alloc_emerg,
1659 	    "Total allocations done from emergency cache");
1660 	rack_to_alloc_limited = counter_u64_alloc(M_WAITOK);
1661 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1662 	    SYSCTL_CHILDREN(rack_counters),
1663 	    OID_AUTO, "alloc_limited", CTLFLAG_RD,
1664 	    &rack_to_alloc_limited,
1665 	    "Total allocations dropped due to limit");
1666 	rack_alloc_limited_conns = counter_u64_alloc(M_WAITOK);
1667 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1668 	    SYSCTL_CHILDREN(rack_counters),
1669 	    OID_AUTO, "alloc_limited_conns", CTLFLAG_RD,
1670 	    &rack_alloc_limited_conns,
1671 	    "Connections with allocations dropped due to limit");
1672 	rack_split_limited = counter_u64_alloc(M_WAITOK);
1673 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1674 	    SYSCTL_CHILDREN(rack_counters),
1675 	    OID_AUTO, "split_limited", CTLFLAG_RD,
1676 	    &rack_split_limited,
1677 	    "Split allocations dropped due to limit");
1678 	rack_persists_sends = counter_u64_alloc(M_WAITOK);
1679 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1680 	    SYSCTL_CHILDREN(rack_counters),
1681 	    OID_AUTO, "persist_sends", CTLFLAG_RD,
1682 	    &rack_persists_sends,
1683 	    "Number of times we sent a persist probe");
1684 	rack_persists_acks = counter_u64_alloc(M_WAITOK);
1685 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1686 	    SYSCTL_CHILDREN(rack_counters),
1687 	    OID_AUTO, "persist_acks", CTLFLAG_RD,
1688 	    &rack_persists_acks,
1689 	    "Number of times a persist probe was acked");
1690 	rack_persists_loss = counter_u64_alloc(M_WAITOK);
1691 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1692 	    SYSCTL_CHILDREN(rack_counters),
1693 	    OID_AUTO, "persist_loss", CTLFLAG_RD,
1694 	    &rack_persists_loss,
1695 	    "Number of times we detected a lost persist probe (no ack)");
1696 	rack_persists_lost_ends = counter_u64_alloc(M_WAITOK);
1697 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1698 	    SYSCTL_CHILDREN(rack_counters),
1699 	    OID_AUTO, "persist_loss_ends", CTLFLAG_RD,
1700 	    &rack_persists_lost_ends,
1701 	    "Number of lost persist probe (no ack) that the run ended with a PERSIST abort");
1702 #ifdef INVARIANTS
1703 	rack_adjust_map_bw = counter_u64_alloc(M_WAITOK);
1704 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1705 	    SYSCTL_CHILDREN(rack_counters),
1706 	    OID_AUTO, "map_adjust_req", CTLFLAG_RD,
1707 	    &rack_adjust_map_bw,
1708 	    "Number of times we hit the case where the sb went up and down on a sendmap entry");
1709 #endif
1710 	rack_multi_single_eq = counter_u64_alloc(M_WAITOK);
1711 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1712 	    SYSCTL_CHILDREN(rack_counters),
1713 	    OID_AUTO, "cmp_ack_equiv", CTLFLAG_RD,
1714 	    &rack_multi_single_eq,
1715 	    "Number of compressed acks total represented");
1716 	rack_proc_non_comp_ack = counter_u64_alloc(M_WAITOK);
1717 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1718 	    SYSCTL_CHILDREN(rack_counters),
1719 	    OID_AUTO, "cmp_ack_not", CTLFLAG_RD,
1720 	    &rack_proc_non_comp_ack,
1721 	    "Number of non compresseds acks that we processed");
1722 
1723 
1724 	rack_sack_proc_all = counter_u64_alloc(M_WAITOK);
1725 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1726 	    SYSCTL_CHILDREN(rack_counters),
1727 	    OID_AUTO, "sack_long", CTLFLAG_RD,
1728 	    &rack_sack_proc_all,
1729 	    "Total times we had to walk whole list for sack processing");
1730 	rack_sack_proc_restart = counter_u64_alloc(M_WAITOK);
1731 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1732 	    SYSCTL_CHILDREN(rack_counters),
1733 	    OID_AUTO, "sack_restart", CTLFLAG_RD,
1734 	    &rack_sack_proc_restart,
1735 	    "Total times we had to walk whole list due to a restart");
1736 	rack_sack_proc_short = counter_u64_alloc(M_WAITOK);
1737 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1738 	    SYSCTL_CHILDREN(rack_counters),
1739 	    OID_AUTO, "sack_short", CTLFLAG_RD,
1740 	    &rack_sack_proc_short,
1741 	    "Total times we took shortcut for sack processing");
1742 	rack_sack_skipped_acked = counter_u64_alloc(M_WAITOK);
1743 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1744 	    SYSCTL_CHILDREN(rack_attack),
1745 	    OID_AUTO, "skipacked", CTLFLAG_RD,
1746 	    &rack_sack_skipped_acked,
1747 	    "Total number of times we skipped previously sacked");
1748 	rack_sack_splits = counter_u64_alloc(M_WAITOK);
1749 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1750 	    SYSCTL_CHILDREN(rack_attack),
1751 	    OID_AUTO, "ofsplit", CTLFLAG_RD,
1752 	    &rack_sack_splits,
1753 	    "Total number of times we did the old fashion tree split");
1754 	rack_input_idle_reduces = counter_u64_alloc(M_WAITOK);
1755 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1756 	    SYSCTL_CHILDREN(rack_counters),
1757 	    OID_AUTO, "idle_reduce_oninput", CTLFLAG_RD,
1758 	    &rack_input_idle_reduces,
1759 	    "Total number of idle reductions on input");
1760 	rack_collapsed_win = counter_u64_alloc(M_WAITOK);
1761 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1762 	    SYSCTL_CHILDREN(rack_counters),
1763 	    OID_AUTO, "collapsed_win", CTLFLAG_RD,
1764 	    &rack_collapsed_win,
1765 	    "Total number of collapsed windows");
1766 	rack_try_scwnd = counter_u64_alloc(M_WAITOK);
1767 	SYSCTL_ADD_COUNTER_U64(&rack_sysctl_ctx,
1768 	    SYSCTL_CHILDREN(rack_counters),
1769 	    OID_AUTO, "tried_scwnd", CTLFLAG_RD,
1770 	    &rack_try_scwnd,
1771 	    "Total number of scwnd attempts");
1772 	COUNTER_ARRAY_ALLOC(rack_out_size, TCP_MSS_ACCT_SIZE, M_WAITOK);
1773 	SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
1774 	    OID_AUTO, "outsize", CTLFLAG_RD,
1775 	    rack_out_size, TCP_MSS_ACCT_SIZE, "MSS send sizes");
1776 	COUNTER_ARRAY_ALLOC(rack_opts_arry, RACK_OPTS_SIZE, M_WAITOK);
1777 	SYSCTL_ADD_COUNTER_U64_ARRAY(&rack_sysctl_ctx, SYSCTL_CHILDREN(rack_sysctl_root),
1778 	    OID_AUTO, "opts", CTLFLAG_RD,
1779 	    rack_opts_arry, RACK_OPTS_SIZE, "RACK Option Stats");
1780 	SYSCTL_ADD_PROC(&rack_sysctl_ctx,
1781 	    SYSCTL_CHILDREN(rack_sysctl_root),
1782 	    OID_AUTO, "clear", CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE,
1783 	    &rack_clear_counter, 0, sysctl_rack_clear, "IU", "Clear counters");
1784 }
1785 
1786 static __inline int
1787 rb_map_cmp(struct rack_sendmap *b, struct rack_sendmap *a)
1788 {
1789 	if (SEQ_GEQ(b->r_start, a->r_start) &&
1790 	    SEQ_LT(b->r_start, a->r_end)) {
1791 		/*
1792 		 * The entry b is within the
1793 		 * block a. i.e.:
1794 		 * a --   |-------------|
1795 		 * b --   |----|
1796 		 * <or>
1797 		 * b --       |------|
1798 		 * <or>
1799 		 * b --       |-----------|
1800 		 */
1801 		return (0);
1802 	} else if (SEQ_GEQ(b->r_start, a->r_end)) {
1803 		/*
1804 		 * b falls as either the next
1805 		 * sequence block after a so a
1806 		 * is said to be smaller than b.
1807 		 * i.e:
1808 		 * a --   |------|
1809 		 * b --          |--------|
1810 		 * or
1811 		 * b --              |-----|
1812 		 */
1813 		return (1);
1814 	}
1815 	/*
1816 	 * Whats left is where a is
1817 	 * larger than b. i.e:
1818 	 * a --         |-------|
1819 	 * b --  |---|
1820 	 * or even possibly
1821 	 * b --   |--------------|
1822 	 */
1823 	return (-1);
1824 }
1825 
1826 RB_PROTOTYPE(rack_rb_tree_head, rack_sendmap, r_next, rb_map_cmp);
1827 RB_GENERATE(rack_rb_tree_head, rack_sendmap, r_next, rb_map_cmp);
1828 
1829 static uint32_t
1830 rc_init_window(struct tcp_rack *rack)
1831 {
1832 	uint32_t win;
1833 
1834 	if (rack->rc_init_win == 0) {
1835 		/*
1836 		 * Nothing set by the user, use the system stack
1837 		 * default.
1838 		 */
1839 		return (tcp_compute_initwnd(tcp_maxseg(rack->rc_tp)));
1840 	}
1841 	win = ctf_fixed_maxseg(rack->rc_tp) * rack->rc_init_win;
1842 	return (win);
1843 }
1844 
1845 static uint64_t
1846 rack_get_fixed_pacing_bw(struct tcp_rack *rack)
1847 {
1848 	if (IN_FASTRECOVERY(rack->rc_tp->t_flags))
1849 		return (rack->r_ctl.rc_fixed_pacing_rate_rec);
1850 	else if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
1851 		return (rack->r_ctl.rc_fixed_pacing_rate_ss);
1852 	else
1853 		return (rack->r_ctl.rc_fixed_pacing_rate_ca);
1854 }
1855 
1856 static uint64_t
1857 rack_get_bw(struct tcp_rack *rack)
1858 {
1859 	if (rack->use_fixed_rate) {
1860 		/* Return the fixed pacing rate */
1861 		return (rack_get_fixed_pacing_bw(rack));
1862 	}
1863 	if (rack->r_ctl.gp_bw == 0) {
1864 		/*
1865 		 * We have yet no b/w measurement,
1866 		 * if we have a user set initial bw
1867 		 * return it. If we don't have that and
1868 		 * we have an srtt, use the tcp IW (10) to
1869 		 * calculate a fictional b/w over the SRTT
1870 		 * which is more or less a guess. Note
1871 		 * we don't use our IW from rack on purpose
1872 		 * so if we have like IW=30, we are not
1873 		 * calculating a "huge" b/w.
1874 		 */
1875 		uint64_t bw, srtt;
1876 		if (rack->r_ctl.init_rate)
1877 			return (rack->r_ctl.init_rate);
1878 
1879 		/* Has the user set a max peak rate? */
1880 #ifdef NETFLIX_PEAKRATE
1881 		if (rack->rc_tp->t_maxpeakrate)
1882 			return (rack->rc_tp->t_maxpeakrate);
1883 #endif
1884 		/* Ok lets come up with the IW guess, if we have a srtt */
1885 		if (rack->rc_tp->t_srtt == 0) {
1886 			/*
1887 			 * Go with old pacing method
1888 			 * i.e. burst mitigation only.
1889 			 */
1890 			return (0);
1891 		}
1892 		/* Ok lets get the initial TCP win (not racks) */
1893 		bw = tcp_compute_initwnd(tcp_maxseg(rack->rc_tp));
1894 		srtt = (uint64_t)rack->rc_tp->t_srtt;
1895 		bw *= (uint64_t)USECS_IN_SECOND;
1896 		bw /= srtt;
1897 		if (rack->r_ctl.bw_rate_cap && (bw > rack->r_ctl.bw_rate_cap))
1898 			bw = rack->r_ctl.bw_rate_cap;
1899 		return (bw);
1900 	} else {
1901 		uint64_t bw;
1902 
1903 		if (rack->r_ctl.num_measurements >= RACK_REQ_AVG) {
1904 			/* Averaging is done, we can return the value */
1905 			bw = rack->r_ctl.gp_bw;
1906 		} else {
1907 			/* Still doing initial average must calculate */
1908 			bw = rack->r_ctl.gp_bw / rack->r_ctl.num_measurements;
1909 		}
1910 #ifdef NETFLIX_PEAKRATE
1911 		if ((rack->rc_tp->t_maxpeakrate) &&
1912 		    (bw > rack->rc_tp->t_maxpeakrate)) {
1913 			/* The user has set a peak rate to pace at
1914 			 * don't allow us to pace faster than that.
1915 			 */
1916 			return (rack->rc_tp->t_maxpeakrate);
1917 		}
1918 #endif
1919 		if (rack->r_ctl.bw_rate_cap && (bw > rack->r_ctl.bw_rate_cap))
1920 			bw = rack->r_ctl.bw_rate_cap;
1921 		return (bw);
1922 	}
1923 }
1924 
1925 static uint16_t
1926 rack_get_output_gain(struct tcp_rack *rack, struct rack_sendmap *rsm)
1927 {
1928 	if (rack->use_fixed_rate) {
1929 		return (100);
1930 	} else if (rack->in_probe_rtt && (rsm == NULL))
1931 		return (rack->r_ctl.rack_per_of_gp_probertt);
1932 	else if ((IN_FASTRECOVERY(rack->rc_tp->t_flags) &&
1933 		  rack->r_ctl.rack_per_of_gp_rec)) {
1934 		if (rsm) {
1935 			/* a retransmission always use the recovery rate */
1936 			return (rack->r_ctl.rack_per_of_gp_rec);
1937 		} else if (rack->rack_rec_nonrxt_use_cr) {
1938 			/* Directed to use the configured rate */
1939 			goto configured_rate;
1940 		} else if (rack->rack_no_prr &&
1941 			   (rack->r_ctl.rack_per_of_gp_rec > 100)) {
1942 			/* No PRR, lets just use the b/w estimate only */
1943 			return (100);
1944 		} else {
1945 			/*
1946 			 * Here we may have a non-retransmit but we
1947 			 * have no overrides, so just use the recovery
1948 			 * rate (prr is in effect).
1949 			 */
1950 			return (rack->r_ctl.rack_per_of_gp_rec);
1951 		}
1952 	}
1953 configured_rate:
1954 	/* For the configured rate we look at our cwnd vs the ssthresh */
1955 	if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh)
1956 		return (rack->r_ctl.rack_per_of_gp_ss);
1957 	else
1958 		return (rack->r_ctl.rack_per_of_gp_ca);
1959 }
1960 
1961 static void
1962 rack_log_dsack_event(struct tcp_rack *rack, uint8_t mod, uint32_t flex4, uint32_t flex5, uint32_t flex6)
1963 {
1964 	/*
1965 	 * Types of logs (mod value)
1966 	 * 1 = dsack_persists reduced by 1 via T-O or fast recovery exit.
1967 	 * 2 = a dsack round begins, persist is reset to 16.
1968 	 * 3 = a dsack round ends
1969 	 * 4 = Dsack option increases rack rtt flex5 is the srtt input, flex6 is thresh
1970 	 * 5 = Socket option set changing the control flags rc_rack_tmr_std_based, rc_rack_use_dsack
1971 	 * 6 = Final rack rtt, flex4 is srtt and flex6 is final limited thresh.
1972 	 */
1973 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
1974 		union tcp_log_stackspecific log;
1975 		struct timeval tv;
1976 
1977 		memset(&log, 0, sizeof(log));
1978 		log.u_bbr.flex1 = rack->rc_rack_tmr_std_based;
1979 		log.u_bbr.flex1 <<= 1;
1980 		log.u_bbr.flex1 |= rack->rc_rack_use_dsack;
1981 		log.u_bbr.flex1 <<= 1;
1982 		log.u_bbr.flex1 |= rack->rc_dsack_round_seen;
1983 		log.u_bbr.flex2 = rack->r_ctl.dsack_round_end;
1984 		log.u_bbr.flex3 = rack->r_ctl.num_dsack;
1985 		log.u_bbr.flex4 = flex4;
1986 		log.u_bbr.flex5 = flex5;
1987 		log.u_bbr.flex6 = flex6;
1988 		log.u_bbr.flex7 = rack->r_ctl.dsack_persist;
1989 		log.u_bbr.flex8 = mod;
1990 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
1991 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
1992 		    &rack->rc_inp->inp_socket->so_rcv,
1993 		    &rack->rc_inp->inp_socket->so_snd,
1994 		    RACK_DSACK_HANDLING, 0,
1995 		    0, &log, false, &tv);
1996 	}
1997 }
1998 
1999 static void
2000 rack_log_hdwr_pacing(struct tcp_rack *rack,
2001 		     uint64_t rate, uint64_t hw_rate, int line,
2002 		     int error, uint16_t mod)
2003 {
2004 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2005 		union tcp_log_stackspecific log;
2006 		struct timeval tv;
2007 		const struct ifnet *ifp;
2008 
2009 		memset(&log, 0, sizeof(log));
2010 		log.u_bbr.flex1 = ((hw_rate >> 32) & 0x00000000ffffffff);
2011 		log.u_bbr.flex2 = (hw_rate & 0x00000000ffffffff);
2012 		if (rack->r_ctl.crte) {
2013 			ifp = rack->r_ctl.crte->ptbl->rs_ifp;
2014 		} else if (rack->rc_inp->inp_route.ro_nh &&
2015 			   rack->rc_inp->inp_route.ro_nh->nh_ifp) {
2016 			ifp = rack->rc_inp->inp_route.ro_nh->nh_ifp;
2017 		} else
2018 			ifp = NULL;
2019 		if (ifp) {
2020 			log.u_bbr.flex3 = (((uint64_t)ifp  >> 32) & 0x00000000ffffffff);
2021 			log.u_bbr.flex4 = ((uint64_t)ifp & 0x00000000ffffffff);
2022 		}
2023 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2024 		log.u_bbr.bw_inuse = rate;
2025 		log.u_bbr.flex5 = line;
2026 		log.u_bbr.flex6 = error;
2027 		log.u_bbr.flex7 = mod;
2028 		log.u_bbr.applimited = rack->r_ctl.rc_pace_max_segs;
2029 		log.u_bbr.flex8 = rack->use_fixed_rate;
2030 		log.u_bbr.flex8 <<= 1;
2031 		log.u_bbr.flex8 |= rack->rack_hdrw_pacing;
2032 		log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
2033 		log.u_bbr.delRate = rack->r_ctl.crte_prev_rate;
2034 		if (rack->r_ctl.crte)
2035 			log.u_bbr.cur_del_rate = rack->r_ctl.crte->rate;
2036 		else
2037 			log.u_bbr.cur_del_rate = 0;
2038 		log.u_bbr.rttProp = rack->r_ctl.last_hw_bw_req;
2039 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2040 		    &rack->rc_inp->inp_socket->so_rcv,
2041 		    &rack->rc_inp->inp_socket->so_snd,
2042 		    BBR_LOG_HDWR_PACE, 0,
2043 		    0, &log, false, &tv);
2044 	}
2045 }
2046 
2047 static uint64_t
2048 rack_get_output_bw(struct tcp_rack *rack, uint64_t bw, struct rack_sendmap *rsm, int *capped)
2049 {
2050 	/*
2051 	 * We allow rack_per_of_gp_xx to dictate our bw rate we want.
2052 	 */
2053 	uint64_t bw_est, high_rate;
2054 	uint64_t gain;
2055 
2056 	gain = (uint64_t)rack_get_output_gain(rack, rsm);
2057 	bw_est = bw * gain;
2058 	bw_est /= (uint64_t)100;
2059 	/* Never fall below the minimum (def 64kbps) */
2060 	if (bw_est < RACK_MIN_BW)
2061 		bw_est = RACK_MIN_BW;
2062 	if (rack->r_rack_hw_rate_caps) {
2063 		/* Rate caps are in place */
2064 		if (rack->r_ctl.crte != NULL) {
2065 			/* We have a hdwr rate already */
2066 			high_rate = tcp_hw_highest_rate(rack->r_ctl.crte);
2067 			if (bw_est >= high_rate) {
2068 				/* We are capping bw at the highest rate table entry */
2069 				rack_log_hdwr_pacing(rack,
2070 						     bw_est, high_rate, __LINE__,
2071 						     0, 3);
2072 				bw_est = high_rate;
2073 				if (capped)
2074 					*capped = 1;
2075 			}
2076 		} else if ((rack->rack_hdrw_pacing == 0) &&
2077 			   (rack->rack_hdw_pace_ena) &&
2078 			   (rack->rack_attempt_hdwr_pace == 0) &&
2079 			   (rack->rc_inp->inp_route.ro_nh != NULL) &&
2080 			   (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
2081 			/*
2082 			 * Special case, we have not yet attempted hardware
2083 			 * pacing, and yet we may, when we do, find out if we are
2084 			 * above the highest rate. We need to know the maxbw for the interface
2085 			 * in question (if it supports ratelimiting). We get back
2086 			 * a 0, if the interface is not found in the RL lists.
2087 			 */
2088 			high_rate = tcp_hw_highest_rate_ifp(rack->rc_inp->inp_route.ro_nh->nh_ifp, rack->rc_inp);
2089 			if (high_rate) {
2090 				/* Yep, we have a rate is it above this rate? */
2091 				if (bw_est > high_rate) {
2092 					bw_est = high_rate;
2093 					if (capped)
2094 						*capped = 1;
2095 				}
2096 			}
2097 		}
2098 	}
2099 	return (bw_est);
2100 }
2101 
2102 static void
2103 rack_log_retran_reason(struct tcp_rack *rack, struct rack_sendmap *rsm, uint32_t tsused, uint32_t thresh, int mod)
2104 {
2105 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2106 		union tcp_log_stackspecific log;
2107 		struct timeval tv;
2108 
2109 		if ((mod != 1) && (rack_verbose_logging == 0)) {
2110 			/*
2111 			 * We get 3 values currently for mod
2112 			 * 1 - We are retransmitting and this tells the reason.
2113 			 * 2 - We are clearing a dup-ack count.
2114 			 * 3 - We are incrementing a dup-ack count.
2115 			 *
2116 			 * The clear/increment are only logged
2117 			 * if you have BBverbose on.
2118 			 */
2119 			return;
2120 		}
2121 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2122 		log.u_bbr.flex1 = tsused;
2123 		log.u_bbr.flex2 = thresh;
2124 		log.u_bbr.flex3 = rsm->r_flags;
2125 		log.u_bbr.flex4 = rsm->r_dupack;
2126 		log.u_bbr.flex5 = rsm->r_start;
2127 		log.u_bbr.flex6 = rsm->r_end;
2128 		log.u_bbr.flex8 = mod;
2129 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2130 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2131 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2132 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2133 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2134 		log.u_bbr.pacing_gain = rack->r_must_retran;
2135 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2136 		    &rack->rc_inp->inp_socket->so_rcv,
2137 		    &rack->rc_inp->inp_socket->so_snd,
2138 		    BBR_LOG_SETTINGS_CHG, 0,
2139 		    0, &log, false, &tv);
2140 	}
2141 }
2142 
2143 static void
2144 rack_log_to_start(struct tcp_rack *rack, uint32_t cts, uint32_t to, int32_t slot, uint8_t which)
2145 {
2146 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2147 		union tcp_log_stackspecific log;
2148 		struct timeval tv;
2149 
2150 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2151 		log.u_bbr.flex1 = rack->rc_tp->t_srtt;
2152 		log.u_bbr.flex2 = to;
2153 		log.u_bbr.flex3 = rack->r_ctl.rc_hpts_flags;
2154 		log.u_bbr.flex4 = slot;
2155 		log.u_bbr.flex5 = rack->rc_inp->inp_hptsslot;
2156 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2157 		log.u_bbr.flex7 = rack->rc_in_persist;
2158 		log.u_bbr.flex8 = which;
2159 		if (rack->rack_no_prr)
2160 			log.u_bbr.pkts_out = 0;
2161 		else
2162 			log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
2163 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2164 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2165 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2166 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2167 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2168 		log.u_bbr.pacing_gain = rack->r_must_retran;
2169 		log.u_bbr.cwnd_gain = rack->rc_has_collapsed;
2170 		log.u_bbr.lt_epoch = rack->rc_tp->t_rxtshift;
2171 		log.u_bbr.lost = rack_rto_min;
2172 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2173 		    &rack->rc_inp->inp_socket->so_rcv,
2174 		    &rack->rc_inp->inp_socket->so_snd,
2175 		    BBR_LOG_TIMERSTAR, 0,
2176 		    0, &log, false, &tv);
2177 	}
2178 }
2179 
2180 static void
2181 rack_log_to_event(struct tcp_rack *rack, int32_t to_num, struct rack_sendmap *rsm)
2182 {
2183 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2184 		union tcp_log_stackspecific log;
2185 		struct timeval tv;
2186 
2187 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2188 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2189 		log.u_bbr.flex8 = to_num;
2190 		log.u_bbr.flex1 = rack->r_ctl.rc_rack_min_rtt;
2191 		log.u_bbr.flex2 = rack->rc_rack_rtt;
2192 		if (rsm == NULL)
2193 			log.u_bbr.flex3 = 0;
2194 		else
2195 			log.u_bbr.flex3 = rsm->r_end - rsm->r_start;
2196 		if (rack->rack_no_prr)
2197 			log.u_bbr.flex5 = 0;
2198 		else
2199 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2200 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2201 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2202 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2203 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2204 		log.u_bbr.pacing_gain = rack->r_must_retran;
2205 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2206 		    &rack->rc_inp->inp_socket->so_rcv,
2207 		    &rack->rc_inp->inp_socket->so_snd,
2208 		    BBR_LOG_RTO, 0,
2209 		    0, &log, false, &tv);
2210 	}
2211 }
2212 
2213 static void
2214 rack_log_map_chg(struct tcpcb *tp, struct tcp_rack *rack,
2215 		 struct rack_sendmap *prev,
2216 		 struct rack_sendmap *rsm,
2217 		 struct rack_sendmap *next,
2218 		 int flag, uint32_t th_ack, int line)
2219 {
2220 	if (rack_verbose_logging && (tp->t_logstate != TCP_LOG_STATE_OFF)) {
2221 		union tcp_log_stackspecific log;
2222 		struct timeval tv;
2223 
2224 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2225 		log.u_bbr.flex8 = flag;
2226 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2227 		log.u_bbr.cur_del_rate = (uint64_t)prev;
2228 		log.u_bbr.delRate = (uint64_t)rsm;
2229 		log.u_bbr.rttProp = (uint64_t)next;
2230 		log.u_bbr.flex7 = 0;
2231 		if (prev) {
2232 			log.u_bbr.flex1 = prev->r_start;
2233 			log.u_bbr.flex2 = prev->r_end;
2234 			log.u_bbr.flex7 |= 0x4;
2235 		}
2236 		if (rsm) {
2237 			log.u_bbr.flex3 = rsm->r_start;
2238 			log.u_bbr.flex4 = rsm->r_end;
2239 			log.u_bbr.flex7 |= 0x2;
2240 		}
2241 		if (next) {
2242 			log.u_bbr.flex5 = next->r_start;
2243 			log.u_bbr.flex6 = next->r_end;
2244 			log.u_bbr.flex7 |= 0x1;
2245 		}
2246 		log.u_bbr.applimited = line;
2247 		log.u_bbr.pkts_out = th_ack;
2248 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2249 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2250 		if (rack->rack_no_prr)
2251 			log.u_bbr.lost = 0;
2252 		else
2253 			log.u_bbr.lost = rack->r_ctl.rc_prr_sndcnt;
2254 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2255 		    &rack->rc_inp->inp_socket->so_rcv,
2256 		    &rack->rc_inp->inp_socket->so_snd,
2257 		    TCP_LOG_MAPCHG, 0,
2258 		    0, &log, false, &tv);
2259 	}
2260 }
2261 
2262 static void
2263 rack_log_rtt_upd(struct tcpcb *tp, struct tcp_rack *rack, uint32_t t, uint32_t len,
2264 		 struct rack_sendmap *rsm, int conf)
2265 {
2266 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
2267 		union tcp_log_stackspecific log;
2268 		struct timeval tv;
2269 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2270 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2271 		log.u_bbr.flex1 = t;
2272 		log.u_bbr.flex2 = len;
2273 		log.u_bbr.flex3 = rack->r_ctl.rc_rack_min_rtt;
2274 		log.u_bbr.flex4 = rack->r_ctl.rack_rs.rs_rtt_lowest;
2275 		log.u_bbr.flex5 = rack->r_ctl.rack_rs.rs_rtt_highest;
2276 		log.u_bbr.flex6 = rack->r_ctl.rack_rs.rs_us_rtrcnt;
2277 		log.u_bbr.flex7 = conf;
2278 		log.u_bbr.rttProp = (uint64_t)rack->r_ctl.rack_rs.rs_rtt_tot;
2279 		log.u_bbr.flex8 = rack->r_ctl.rc_rate_sample_method;
2280 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2281 		log.u_bbr.delivered = rack->r_ctl.rack_rs.rs_us_rtrcnt;
2282 		log.u_bbr.pkts_out = rack->r_ctl.rack_rs.rs_flags;
2283 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2284 		if (rsm) {
2285 			log.u_bbr.pkt_epoch = rsm->r_start;
2286 			log.u_bbr.lost = rsm->r_end;
2287 			log.u_bbr.cwnd_gain = rsm->r_rtr_cnt;
2288 			/* We loose any upper of the 24 bits */
2289 			log.u_bbr.pacing_gain = (uint16_t)rsm->r_flags;
2290 		} else {
2291 			/* Its a SYN */
2292 			log.u_bbr.pkt_epoch = rack->rc_tp->iss;
2293 			log.u_bbr.lost = 0;
2294 			log.u_bbr.cwnd_gain = 0;
2295 			log.u_bbr.pacing_gain = 0;
2296 		}
2297 		/* Write out general bits of interest rrs here */
2298 		log.u_bbr.use_lt_bw = rack->rc_highly_buffered;
2299 		log.u_bbr.use_lt_bw <<= 1;
2300 		log.u_bbr.use_lt_bw |= rack->forced_ack;
2301 		log.u_bbr.use_lt_bw <<= 1;
2302 		log.u_bbr.use_lt_bw |= rack->rc_gp_dyn_mul;
2303 		log.u_bbr.use_lt_bw <<= 1;
2304 		log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
2305 		log.u_bbr.use_lt_bw <<= 1;
2306 		log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
2307 		log.u_bbr.use_lt_bw <<= 1;
2308 		log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
2309 		log.u_bbr.use_lt_bw <<= 1;
2310 		log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
2311 		log.u_bbr.use_lt_bw <<= 1;
2312 		log.u_bbr.use_lt_bw |= rack->rc_dragged_bottom;
2313 		log.u_bbr.applimited = rack->r_ctl.rc_target_probertt_flight;
2314 		log.u_bbr.epoch = rack->r_ctl.rc_time_probertt_starts;
2315 		log.u_bbr.lt_epoch = rack->r_ctl.rc_time_probertt_entered;
2316 		log.u_bbr.cur_del_rate = rack->r_ctl.rc_lower_rtt_us_cts;
2317 		log.u_bbr.delRate = rack->r_ctl.rc_gp_srtt;
2318 		log.u_bbr.bw_inuse = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
2319 		log.u_bbr.bw_inuse <<= 32;
2320 		if (rsm)
2321 			log.u_bbr.bw_inuse |= ((uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]);
2322 		TCP_LOG_EVENTP(tp, NULL,
2323 		    &rack->rc_inp->inp_socket->so_rcv,
2324 		    &rack->rc_inp->inp_socket->so_snd,
2325 		    BBR_LOG_BBRRTT, 0,
2326 		    0, &log, false, &tv);
2327 
2328 
2329 	}
2330 }
2331 
2332 static void
2333 rack_log_rtt_sample(struct tcp_rack *rack, uint32_t rtt)
2334 {
2335 	/*
2336 	 * Log the rtt sample we are
2337 	 * applying to the srtt algorithm in
2338 	 * useconds.
2339 	 */
2340 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2341 		union tcp_log_stackspecific log;
2342 		struct timeval tv;
2343 
2344 		/* Convert our ms to a microsecond */
2345 		memset(&log, 0, sizeof(log));
2346 		log.u_bbr.flex1 = rtt;
2347 		log.u_bbr.flex2 = rack->r_ctl.ack_count;
2348 		log.u_bbr.flex3 = rack->r_ctl.sack_count;
2349 		log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move;
2350 		log.u_bbr.flex5 = rack->r_ctl.sack_moved_extra;
2351 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2352 		log.u_bbr.flex7 = 1;
2353 		log.u_bbr.flex8 = rack->sack_attack_disable;
2354 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2355 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2356 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2357 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2358 		log.u_bbr.pacing_gain = rack->r_must_retran;
2359 		/*
2360 		 * We capture in delRate the upper 32 bits as
2361 		 * the confidence level we had declared, and the
2362 		 * lower 32 bits as the actual RTT using the arrival
2363 		 * timestamp.
2364 		 */
2365 		log.u_bbr.delRate = rack->r_ctl.rack_rs.confidence;
2366 		log.u_bbr.delRate <<= 32;
2367 		log.u_bbr.delRate |= rack->r_ctl.rack_rs.rs_us_rtt;
2368 		/* Lets capture all the things that make up t_rtxcur */
2369 		log.u_bbr.applimited = rack_rto_min;
2370 		log.u_bbr.epoch = rack_rto_max;
2371 		log.u_bbr.lt_epoch = rack->r_ctl.timer_slop;
2372 		log.u_bbr.lost = rack_rto_min;
2373 		log.u_bbr.pkt_epoch = TICKS_2_USEC(tcp_rexmit_slop);
2374 		log.u_bbr.rttProp = RACK_REXMTVAL(rack->rc_tp);
2375 		log.u_bbr.bw_inuse = rack->r_ctl.act_rcv_time.tv_sec;
2376 		log.u_bbr.bw_inuse *= HPTS_USEC_IN_SEC;
2377 		log.u_bbr.bw_inuse += rack->r_ctl.act_rcv_time.tv_usec;
2378 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2379 		    &rack->rc_inp->inp_socket->so_rcv,
2380 		    &rack->rc_inp->inp_socket->so_snd,
2381 		    TCP_LOG_RTT, 0,
2382 		    0, &log, false, &tv);
2383 	}
2384 }
2385 
2386 static void
2387 rack_log_rtt_sample_calc(struct tcp_rack *rack, uint32_t rtt, uint32_t send_time, uint32_t ack_time, int where)
2388 {
2389 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
2390 		union tcp_log_stackspecific log;
2391 		struct timeval tv;
2392 
2393 		/* Convert our ms to a microsecond */
2394 		memset(&log, 0, sizeof(log));
2395 		log.u_bbr.flex1 = rtt;
2396 		log.u_bbr.flex2 = send_time;
2397 		log.u_bbr.flex3 = ack_time;
2398 		log.u_bbr.flex4 = where;
2399 		log.u_bbr.flex7 = 2;
2400 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2401 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2402 		    &rack->rc_inp->inp_socket->so_rcv,
2403 		    &rack->rc_inp->inp_socket->so_snd,
2404 		    TCP_LOG_RTT, 0,
2405 		    0, &log, false, &tv);
2406 	}
2407 }
2408 
2409 
2410 
2411 static inline void
2412 rack_log_progress_event(struct tcp_rack *rack, struct tcpcb *tp, uint32_t tick,  int event, int line)
2413 {
2414 	if (rack_verbose_logging && (tp->t_logstate != TCP_LOG_STATE_OFF)) {
2415 		union tcp_log_stackspecific log;
2416 		struct timeval tv;
2417 
2418 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2419 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2420 		log.u_bbr.flex1 = line;
2421 		log.u_bbr.flex2 = tick;
2422 		log.u_bbr.flex3 = tp->t_maxunacktime;
2423 		log.u_bbr.flex4 = tp->t_acktime;
2424 		log.u_bbr.flex8 = event;
2425 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2426 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2427 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2428 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2429 		log.u_bbr.pacing_gain = rack->r_must_retran;
2430 		TCP_LOG_EVENTP(tp, NULL,
2431 		    &rack->rc_inp->inp_socket->so_rcv,
2432 		    &rack->rc_inp->inp_socket->so_snd,
2433 		    BBR_LOG_PROGRESS, 0,
2434 		    0, &log, false, &tv);
2435 	}
2436 }
2437 
2438 static void
2439 rack_log_type_bbrsnd(struct tcp_rack *rack, uint32_t len, uint32_t slot, uint32_t cts, struct timeval *tv)
2440 {
2441 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2442 		union tcp_log_stackspecific log;
2443 
2444 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2445 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2446 		log.u_bbr.flex1 = slot;
2447 		if (rack->rack_no_prr)
2448 			log.u_bbr.flex2 = 0;
2449 		else
2450 			log.u_bbr.flex2 = rack->r_ctl.rc_prr_sndcnt;
2451 		log.u_bbr.flex7 = (0x0000ffff & rack->r_ctl.rc_hpts_flags);
2452 		log.u_bbr.flex8 = rack->rc_in_persist;
2453 		log.u_bbr.timeStamp = cts;
2454 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2455 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2456 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2457 		log.u_bbr.pacing_gain = rack->r_must_retran;
2458 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2459 		    &rack->rc_inp->inp_socket->so_rcv,
2460 		    &rack->rc_inp->inp_socket->so_snd,
2461 		    BBR_LOG_BBRSND, 0,
2462 		    0, &log, false, tv);
2463 	}
2464 }
2465 
2466 static void
2467 rack_log_doseg_done(struct tcp_rack *rack, uint32_t cts, int32_t nxt_pkt, int32_t did_out, int way_out, int nsegs)
2468 {
2469 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2470 		union tcp_log_stackspecific log;
2471 		struct timeval tv;
2472 
2473 		memset(&log, 0, sizeof(log));
2474 		log.u_bbr.flex1 = did_out;
2475 		log.u_bbr.flex2 = nxt_pkt;
2476 		log.u_bbr.flex3 = way_out;
2477 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
2478 		if (rack->rack_no_prr)
2479 			log.u_bbr.flex5 = 0;
2480 		else
2481 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2482 		log.u_bbr.flex6 = nsegs;
2483 		log.u_bbr.applimited = rack->r_ctl.rc_pace_min_segs;
2484 		log.u_bbr.flex7 = rack->rc_ack_can_sendout_data;	/* Do we have ack-can-send set */
2485 		log.u_bbr.flex7 <<= 1;
2486 		log.u_bbr.flex7 |= rack->r_fast_output;	/* is fast output primed */
2487 		log.u_bbr.flex7 <<= 1;
2488 		log.u_bbr.flex7 |= rack->r_wanted_output;	/* Do we want output */
2489 		log.u_bbr.flex8 = rack->rc_in_persist;
2490 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2491 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2492 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2493 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
2494 		log.u_bbr.use_lt_bw <<= 1;
2495 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
2496 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2497 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2498 		log.u_bbr.pacing_gain = rack->r_must_retran;
2499 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2500 		    &rack->rc_inp->inp_socket->so_rcv,
2501 		    &rack->rc_inp->inp_socket->so_snd,
2502 		    BBR_LOG_DOSEG_DONE, 0,
2503 		    0, &log, false, &tv);
2504 	}
2505 }
2506 
2507 static void
2508 rack_log_type_pacing_sizes(struct tcpcb *tp, struct tcp_rack *rack, uint32_t arg1, uint32_t arg2, uint32_t arg3, uint8_t frm)
2509 {
2510 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
2511 		union tcp_log_stackspecific log;
2512 		struct timeval tv;
2513 
2514 		memset(&log, 0, sizeof(log));
2515 		log.u_bbr.flex1 = rack->r_ctl.rc_pace_min_segs;
2516 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
2517 		log.u_bbr.flex4 = arg1;
2518 		log.u_bbr.flex5 = arg2;
2519 		log.u_bbr.flex6 = arg3;
2520 		log.u_bbr.flex8 = frm;
2521 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2522 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2523 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2524 		log.u_bbr.applimited = rack->r_ctl.rc_sacked;
2525 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2526 		log.u_bbr.pacing_gain = rack->r_must_retran;
2527 		TCP_LOG_EVENTP(tp, NULL,
2528 		    &tp->t_inpcb->inp_socket->so_rcv,
2529 		    &tp->t_inpcb->inp_socket->so_snd,
2530 		    TCP_HDWR_PACE_SIZE, 0,
2531 		    0, &log, false, &tv);
2532 	}
2533 }
2534 
2535 static void
2536 rack_log_type_just_return(struct tcp_rack *rack, uint32_t cts, uint32_t tlen, uint32_t slot,
2537 			  uint8_t hpts_calling, int reason, uint32_t cwnd_to_use)
2538 {
2539 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2540 		union tcp_log_stackspecific log;
2541 		struct timeval tv;
2542 
2543 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2544 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2545 		log.u_bbr.flex1 = slot;
2546 		log.u_bbr.flex2 = rack->r_ctl.rc_hpts_flags;
2547 		log.u_bbr.flex4 = reason;
2548 		if (rack->rack_no_prr)
2549 			log.u_bbr.flex5 = 0;
2550 		else
2551 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2552 		log.u_bbr.flex7 = hpts_calling;
2553 		log.u_bbr.flex8 = rack->rc_in_persist;
2554 		log.u_bbr.lt_epoch = cwnd_to_use;
2555 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2556 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2557 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2558 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2559 		log.u_bbr.pacing_gain = rack->r_must_retran;
2560 		log.u_bbr.cwnd_gain = rack->rc_has_collapsed;
2561 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2562 		    &rack->rc_inp->inp_socket->so_rcv,
2563 		    &rack->rc_inp->inp_socket->so_snd,
2564 		    BBR_LOG_JUSTRET, 0,
2565 		    tlen, &log, false, &tv);
2566 	}
2567 }
2568 
2569 static void
2570 rack_log_to_cancel(struct tcp_rack *rack, int32_t hpts_removed, int line, uint32_t us_cts,
2571 		   struct timeval *tv, uint32_t flags_on_entry)
2572 {
2573 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2574 		union tcp_log_stackspecific log;
2575 
2576 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2577 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
2578 		log.u_bbr.flex1 = line;
2579 		log.u_bbr.flex2 = rack->r_ctl.rc_last_output_to;
2580 		log.u_bbr.flex3 = flags_on_entry;
2581 		log.u_bbr.flex4 = us_cts;
2582 		if (rack->rack_no_prr)
2583 			log.u_bbr.flex5 = 0;
2584 		else
2585 			log.u_bbr.flex5 = rack->r_ctl.rc_prr_sndcnt;
2586 		log.u_bbr.flex6 = rack->rc_tp->t_rxtcur;
2587 		log.u_bbr.flex7 = hpts_removed;
2588 		log.u_bbr.flex8 = 1;
2589 		log.u_bbr.applimited = rack->r_ctl.rc_hpts_flags;
2590 		log.u_bbr.timeStamp = us_cts;
2591 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2592 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2593 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2594 		log.u_bbr.pacing_gain = rack->r_must_retran;
2595 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2596 		    &rack->rc_inp->inp_socket->so_rcv,
2597 		    &rack->rc_inp->inp_socket->so_snd,
2598 		    BBR_LOG_TIMERCANC, 0,
2599 		    0, &log, false, tv);
2600 	}
2601 }
2602 
2603 static void
2604 rack_log_alt_to_to_cancel(struct tcp_rack *rack,
2605 			  uint32_t flex1, uint32_t flex2,
2606 			  uint32_t flex3, uint32_t flex4,
2607 			  uint32_t flex5, uint32_t flex6,
2608 			  uint16_t flex7, uint8_t mod)
2609 {
2610 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2611 		union tcp_log_stackspecific log;
2612 		struct timeval tv;
2613 
2614 		if (mod == 1) {
2615 			/* No you can't use 1, its for the real to cancel */
2616 			return;
2617 		}
2618 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2619 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2620 		log.u_bbr.flex1 = flex1;
2621 		log.u_bbr.flex2 = flex2;
2622 		log.u_bbr.flex3 = flex3;
2623 		log.u_bbr.flex4 = flex4;
2624 		log.u_bbr.flex5 = flex5;
2625 		log.u_bbr.flex6 = flex6;
2626 		log.u_bbr.flex7 = flex7;
2627 		log.u_bbr.flex8 = mod;
2628 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2629 		    &rack->rc_inp->inp_socket->so_rcv,
2630 		    &rack->rc_inp->inp_socket->so_snd,
2631 		    BBR_LOG_TIMERCANC, 0,
2632 		    0, &log, false, &tv);
2633 	}
2634 }
2635 
2636 static void
2637 rack_log_to_processing(struct tcp_rack *rack, uint32_t cts, int32_t ret, int32_t timers)
2638 {
2639 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2640 		union tcp_log_stackspecific log;
2641 		struct timeval tv;
2642 
2643 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2644 		log.u_bbr.flex1 = timers;
2645 		log.u_bbr.flex2 = ret;
2646 		log.u_bbr.flex3 = rack->r_ctl.rc_timer_exp;
2647 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
2648 		log.u_bbr.flex5 = cts;
2649 		if (rack->rack_no_prr)
2650 			log.u_bbr.flex6 = 0;
2651 		else
2652 			log.u_bbr.flex6 = rack->r_ctl.rc_prr_sndcnt;
2653 		log.u_bbr.pkts_out = rack->r_ctl.rc_out_at_rto;
2654 		log.u_bbr.delivered = rack->r_ctl.rc_snd_max_at_rto;
2655 		log.u_bbr.pacing_gain = rack->r_must_retran;
2656 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2657 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2658 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2659 		    &rack->rc_inp->inp_socket->so_rcv,
2660 		    &rack->rc_inp->inp_socket->so_snd,
2661 		    BBR_LOG_TO_PROCESS, 0,
2662 		    0, &log, false, &tv);
2663 	}
2664 }
2665 
2666 static void
2667 rack_log_to_prr(struct tcp_rack *rack, int frm, int orig_cwnd, int line)
2668 {
2669 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2670 		union tcp_log_stackspecific log;
2671 		struct timeval tv;
2672 
2673 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2674 		log.u_bbr.flex1 = rack->r_ctl.rc_prr_out;
2675 		log.u_bbr.flex2 = rack->r_ctl.rc_prr_recovery_fs;
2676 		if (rack->rack_no_prr)
2677 			log.u_bbr.flex3 = 0;
2678 		else
2679 			log.u_bbr.flex3 = rack->r_ctl.rc_prr_sndcnt;
2680 		log.u_bbr.flex4 = rack->r_ctl.rc_prr_delivered;
2681 		log.u_bbr.flex5 = rack->r_ctl.rc_sacked;
2682 		log.u_bbr.flex6 = rack->r_ctl.rc_holes_rxt;
2683 		log.u_bbr.flex7 = line;
2684 		log.u_bbr.flex8 = frm;
2685 		log.u_bbr.pkts_out = orig_cwnd;
2686 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2687 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2688 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
2689 		log.u_bbr.use_lt_bw <<= 1;
2690 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
2691 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2692 		    &rack->rc_inp->inp_socket->so_rcv,
2693 		    &rack->rc_inp->inp_socket->so_snd,
2694 		    BBR_LOG_BBRUPD, 0,
2695 		    0, &log, false, &tv);
2696 	}
2697 }
2698 
2699 #ifdef NETFLIX_EXP_DETECTION
2700 static void
2701 rack_log_sad(struct tcp_rack *rack, int event)
2702 {
2703 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
2704 		union tcp_log_stackspecific log;
2705 		struct timeval tv;
2706 
2707 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2708 		log.u_bbr.flex1 = rack->r_ctl.sack_count;
2709 		log.u_bbr.flex2 = rack->r_ctl.ack_count;
2710 		log.u_bbr.flex3 = rack->r_ctl.sack_moved_extra;
2711 		log.u_bbr.flex4 = rack->r_ctl.sack_noextra_move;
2712 		log.u_bbr.flex5 = rack->r_ctl.rc_num_maps_alloced;
2713 		log.u_bbr.flex6 = tcp_sack_to_ack_thresh;
2714 		log.u_bbr.pkts_out = tcp_sack_to_move_thresh;
2715 		log.u_bbr.lt_epoch = (tcp_force_detection << 8);
2716 		log.u_bbr.lt_epoch |= rack->do_detection;
2717 		log.u_bbr.applimited = tcp_map_minimum;
2718 		log.u_bbr.flex7 = rack->sack_attack_disable;
2719 		log.u_bbr.flex8 = event;
2720 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2721 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
2722 		log.u_bbr.delivered = tcp_sad_decay_val;
2723 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
2724 		    &rack->rc_inp->inp_socket->so_rcv,
2725 		    &rack->rc_inp->inp_socket->so_snd,
2726 		    TCP_SAD_DETECTION, 0,
2727 		    0, &log, false, &tv);
2728 	}
2729 }
2730 #endif
2731 
2732 static void
2733 rack_counter_destroy(void)
2734 {
2735 	counter_u64_free(rack_fto_send);
2736 	counter_u64_free(rack_fto_rsm_send);
2737 	counter_u64_free(rack_nfto_resend);
2738 	counter_u64_free(rack_hw_pace_init_fail);
2739 	counter_u64_free(rack_hw_pace_lost);
2740 	counter_u64_free(rack_non_fto_send);
2741 	counter_u64_free(rack_extended_rfo);
2742 	counter_u64_free(rack_ack_total);
2743 	counter_u64_free(rack_express_sack);
2744 	counter_u64_free(rack_sack_total);
2745 	counter_u64_free(rack_move_none);
2746 	counter_u64_free(rack_move_some);
2747 	counter_u64_free(rack_sack_attacks_detected);
2748 	counter_u64_free(rack_sack_attacks_reversed);
2749 	counter_u64_free(rack_sack_used_next_merge);
2750 	counter_u64_free(rack_sack_used_prev_merge);
2751 	counter_u64_free(rack_tlp_tot);
2752 	counter_u64_free(rack_tlp_newdata);
2753 	counter_u64_free(rack_tlp_retran);
2754 	counter_u64_free(rack_tlp_retran_bytes);
2755 	counter_u64_free(rack_to_tot);
2756 	counter_u64_free(rack_saw_enobuf);
2757 	counter_u64_free(rack_saw_enobuf_hw);
2758 	counter_u64_free(rack_saw_enetunreach);
2759 	counter_u64_free(rack_hot_alloc);
2760 	counter_u64_free(rack_to_alloc);
2761 	counter_u64_free(rack_to_alloc_hard);
2762 	counter_u64_free(rack_to_alloc_emerg);
2763 	counter_u64_free(rack_to_alloc_limited);
2764 	counter_u64_free(rack_alloc_limited_conns);
2765 	counter_u64_free(rack_split_limited);
2766 	counter_u64_free(rack_multi_single_eq);
2767 	counter_u64_free(rack_proc_non_comp_ack);
2768 	counter_u64_free(rack_sack_proc_all);
2769 	counter_u64_free(rack_sack_proc_restart);
2770 	counter_u64_free(rack_sack_proc_short);
2771 	counter_u64_free(rack_sack_skipped_acked);
2772 	counter_u64_free(rack_sack_splits);
2773 	counter_u64_free(rack_input_idle_reduces);
2774 	counter_u64_free(rack_collapsed_win);
2775 	counter_u64_free(rack_try_scwnd);
2776 	counter_u64_free(rack_persists_sends);
2777 	counter_u64_free(rack_persists_acks);
2778 	counter_u64_free(rack_persists_loss);
2779 	counter_u64_free(rack_persists_lost_ends);
2780 #ifdef INVARIANTS
2781 	counter_u64_free(rack_adjust_map_bw);
2782 #endif
2783 	COUNTER_ARRAY_FREE(rack_out_size, TCP_MSS_ACCT_SIZE);
2784 	COUNTER_ARRAY_FREE(rack_opts_arry, RACK_OPTS_SIZE);
2785 }
2786 
2787 static struct rack_sendmap *
2788 rack_alloc(struct tcp_rack *rack)
2789 {
2790 	struct rack_sendmap *rsm;
2791 
2792 	/*
2793 	 * First get the top of the list it in
2794 	 * theory is the "hottest" rsm we have,
2795 	 * possibly just freed by ack processing.
2796 	 */
2797 	if (rack->rc_free_cnt > rack_free_cache) {
2798 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
2799 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
2800 		counter_u64_add(rack_hot_alloc, 1);
2801 		rack->rc_free_cnt--;
2802 		return (rsm);
2803 	}
2804 	/*
2805 	 * Once we get under our free cache we probably
2806 	 * no longer have a "hot" one available. Lets
2807 	 * get one from UMA.
2808 	 */
2809 	rsm = uma_zalloc(rack_zone, M_NOWAIT);
2810 	if (rsm) {
2811 		rack->r_ctl.rc_num_maps_alloced++;
2812 		counter_u64_add(rack_to_alloc, 1);
2813 		return (rsm);
2814 	}
2815 	/*
2816 	 * Dig in to our aux rsm's (the last two) since
2817 	 * UMA failed to get us one.
2818 	 */
2819 	if (rack->rc_free_cnt) {
2820 		counter_u64_add(rack_to_alloc_emerg, 1);
2821 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
2822 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
2823 		rack->rc_free_cnt--;
2824 		return (rsm);
2825 	}
2826 	return (NULL);
2827 }
2828 
2829 static struct rack_sendmap *
2830 rack_alloc_full_limit(struct tcp_rack *rack)
2831 {
2832 	if ((V_tcp_map_entries_limit > 0) &&
2833 	    (rack->do_detection == 0) &&
2834 	    (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
2835 		counter_u64_add(rack_to_alloc_limited, 1);
2836 		if (!rack->alloc_limit_reported) {
2837 			rack->alloc_limit_reported = 1;
2838 			counter_u64_add(rack_alloc_limited_conns, 1);
2839 		}
2840 		return (NULL);
2841 	}
2842 	return (rack_alloc(rack));
2843 }
2844 
2845 /* wrapper to allocate a sendmap entry, subject to a specific limit */
2846 static struct rack_sendmap *
2847 rack_alloc_limit(struct tcp_rack *rack, uint8_t limit_type)
2848 {
2849 	struct rack_sendmap *rsm;
2850 
2851 	if (limit_type) {
2852 		/* currently there is only one limit type */
2853 		if (V_tcp_map_split_limit > 0 &&
2854 		    (rack->do_detection == 0) &&
2855 		    rack->r_ctl.rc_num_split_allocs >= V_tcp_map_split_limit) {
2856 			counter_u64_add(rack_split_limited, 1);
2857 			if (!rack->alloc_limit_reported) {
2858 				rack->alloc_limit_reported = 1;
2859 				counter_u64_add(rack_alloc_limited_conns, 1);
2860 			}
2861 			return (NULL);
2862 		}
2863 	}
2864 
2865 	/* allocate and mark in the limit type, if set */
2866 	rsm = rack_alloc(rack);
2867 	if (rsm != NULL && limit_type) {
2868 		rsm->r_limit_type = limit_type;
2869 		rack->r_ctl.rc_num_split_allocs++;
2870 	}
2871 	return (rsm);
2872 }
2873 
2874 static void
2875 rack_free(struct tcp_rack *rack, struct rack_sendmap *rsm)
2876 {
2877 	if (rsm->r_flags & RACK_APP_LIMITED) {
2878 		if (rack->r_ctl.rc_app_limited_cnt > 0) {
2879 			rack->r_ctl.rc_app_limited_cnt--;
2880 		}
2881 	}
2882 	if (rsm->r_limit_type) {
2883 		/* currently there is only one limit type */
2884 		rack->r_ctl.rc_num_split_allocs--;
2885 	}
2886 	if (rsm == rack->r_ctl.rc_first_appl) {
2887 		if (rack->r_ctl.rc_app_limited_cnt == 0)
2888 			rack->r_ctl.rc_first_appl = NULL;
2889 		else {
2890 			/* Follow the next one out */
2891 			struct rack_sendmap fe;
2892 
2893 			fe.r_start = rsm->r_nseq_appl;
2894 			rack->r_ctl.rc_first_appl = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
2895 		}
2896 	}
2897 	if (rsm == rack->r_ctl.rc_resend)
2898 		rack->r_ctl.rc_resend = NULL;
2899 	if (rsm == rack->r_ctl.rc_end_appl)
2900 		rack->r_ctl.rc_end_appl = NULL;
2901 	if (rack->r_ctl.rc_tlpsend == rsm)
2902 		rack->r_ctl.rc_tlpsend = NULL;
2903 	if (rack->r_ctl.rc_sacklast == rsm)
2904 		rack->r_ctl.rc_sacklast = NULL;
2905 	memset(rsm, 0, sizeof(struct rack_sendmap));
2906 	TAILQ_INSERT_HEAD(&rack->r_ctl.rc_free, rsm, r_tnext);
2907 	rack->rc_free_cnt++;
2908 }
2909 
2910 static void
2911 rack_free_trim(struct tcp_rack *rack)
2912 {
2913 	struct rack_sendmap *rsm;
2914 
2915 	/*
2916 	 * Free up all the tail entries until
2917 	 * we get our list down to the limit.
2918 	 */
2919 	while (rack->rc_free_cnt > rack_free_cache) {
2920 		rsm = TAILQ_LAST(&rack->r_ctl.rc_free, rack_head);
2921 		TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
2922 		rack->rc_free_cnt--;
2923 		uma_zfree(rack_zone, rsm);
2924 	}
2925 }
2926 
2927 
2928 static uint32_t
2929 rack_get_measure_window(struct tcpcb *tp, struct tcp_rack *rack)
2930 {
2931 	uint64_t srtt, bw, len, tim;
2932 	uint32_t segsiz, def_len, minl;
2933 
2934 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
2935 	def_len = rack_def_data_window * segsiz;
2936 	if (rack->rc_gp_filled == 0) {
2937 		/*
2938 		 * We have no measurement (IW is in flight?) so
2939 		 * we can only guess using our data_window sysctl
2940 		 * value (usually 20MSS).
2941 		 */
2942 		return (def_len);
2943 	}
2944 	/*
2945 	 * Now we have a number of factors to consider.
2946 	 *
2947 	 * 1) We have a desired BDP which is usually
2948 	 *    at least 2.
2949 	 * 2) We have a minimum number of rtt's usually 1 SRTT
2950 	 *    but we allow it too to be more.
2951 	 * 3) We want to make sure a measurement last N useconds (if
2952 	 *    we have set rack_min_measure_usec.
2953 	 *
2954 	 * We handle the first concern here by trying to create a data
2955 	 * window of max(rack_def_data_window, DesiredBDP). The
2956 	 * second concern we handle in not letting the measurement
2957 	 * window end normally until at least the required SRTT's
2958 	 * have gone by which is done further below in
2959 	 * rack_enough_for_measurement(). Finally the third concern
2960 	 * we also handle here by calculating how long that time
2961 	 * would take at the current BW and then return the
2962 	 * max of our first calculation and that length. Note
2963 	 * that if rack_min_measure_usec is 0, we don't deal
2964 	 * with concern 3. Also for both Concern 1 and 3 an
2965 	 * application limited period could end the measurement
2966 	 * earlier.
2967 	 *
2968 	 * So lets calculate the BDP with the "known" b/w using
2969 	 * the SRTT has our rtt and then multiply it by the
2970 	 * goal.
2971 	 */
2972 	bw = rack_get_bw(rack);
2973 	srtt = (uint64_t)tp->t_srtt;
2974 	len = bw * srtt;
2975 	len /= (uint64_t)HPTS_USEC_IN_SEC;
2976 	len *= max(1, rack_goal_bdp);
2977 	/* Now we need to round up to the nearest MSS */
2978 	len = roundup(len, segsiz);
2979 	if (rack_min_measure_usec) {
2980 		/* Now calculate our min length for this b/w */
2981 		tim = rack_min_measure_usec;
2982 		minl = (tim * bw) / (uint64_t)HPTS_USEC_IN_SEC;
2983 		if (minl == 0)
2984 			minl = 1;
2985 		minl = roundup(minl, segsiz);
2986 		if (len < minl)
2987 			len = minl;
2988 	}
2989 	/*
2990 	 * Now if we have a very small window we want
2991 	 * to attempt to get the window that is
2992 	 * as small as possible. This happens on
2993 	 * low b/w connections and we don't want to
2994 	 * span huge numbers of rtt's between measurements.
2995 	 *
2996 	 * We basically include 2 over our "MIN window" so
2997 	 * that the measurement can be shortened (possibly) by
2998 	 * an ack'ed packet.
2999 	 */
3000 	if (len < def_len)
3001 		return (max((uint32_t)len, ((MIN_GP_WIN+2) * segsiz)));
3002 	else
3003 		return (max((uint32_t)len, def_len));
3004 
3005 }
3006 
3007 static int
3008 rack_enough_for_measurement(struct tcpcb *tp, struct tcp_rack *rack, tcp_seq th_ack, uint8_t *quality)
3009 {
3010 	uint32_t tim, srtts, segsiz;
3011 
3012 	/*
3013 	 * Has enough time passed for the GP measurement to be valid?
3014 	 */
3015 	if ((tp->snd_max == tp->snd_una) ||
3016 	    (th_ack == tp->snd_max)){
3017 		/* All is acked */
3018 		*quality = RACK_QUALITY_ALLACKED;
3019 		return (1);
3020 	}
3021 	if (SEQ_LT(th_ack, tp->gput_seq)) {
3022 		/* Not enough bytes yet */
3023 		return (0);
3024 	}
3025 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
3026 	if (SEQ_LT(th_ack, tp->gput_ack) &&
3027 	    ((th_ack - tp->gput_seq) < max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
3028 		/* Not enough bytes yet */
3029 		return (0);
3030 	}
3031 	if (rack->r_ctl.rc_first_appl &&
3032 	    (SEQ_GEQ(th_ack, rack->r_ctl.rc_first_appl->r_end))) {
3033 		/*
3034 		 * We are up to the app limited send point
3035 		 * we have to measure irrespective of the time..
3036 		 */
3037 		*quality = RACK_QUALITY_APPLIMITED;
3038 		return (1);
3039 	}
3040 	/* Now what about time? */
3041 	srtts = (rack->r_ctl.rc_gp_srtt * rack_min_srtts);
3042 	tim = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - tp->gput_ts;
3043 	if (tim >= srtts) {
3044 		*quality = RACK_QUALITY_HIGH;
3045 		return (1);
3046 	}
3047 	/* Nope not even a full SRTT has passed */
3048 	return (0);
3049 }
3050 
3051 static void
3052 rack_log_timely(struct tcp_rack *rack,
3053 		uint32_t logged, uint64_t cur_bw, uint64_t low_bnd,
3054 		uint64_t up_bnd, int line, uint8_t method)
3055 {
3056 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
3057 		union tcp_log_stackspecific log;
3058 		struct timeval tv;
3059 
3060 		memset(&log, 0, sizeof(log));
3061 		log.u_bbr.flex1 = logged;
3062 		log.u_bbr.flex2 = rack->rc_gp_timely_inc_cnt;
3063 		log.u_bbr.flex2 <<= 4;
3064 		log.u_bbr.flex2 |= rack->rc_gp_timely_dec_cnt;
3065 		log.u_bbr.flex2 <<= 4;
3066 		log.u_bbr.flex2 |= rack->rc_gp_incr;
3067 		log.u_bbr.flex2 <<= 4;
3068 		log.u_bbr.flex2 |= rack->rc_gp_bwred;
3069 		log.u_bbr.flex3 = rack->rc_gp_incr;
3070 		log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
3071 		log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ca;
3072 		log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_rec;
3073 		log.u_bbr.flex7 = rack->rc_gp_bwred;
3074 		log.u_bbr.flex8 = method;
3075 		log.u_bbr.cur_del_rate = cur_bw;
3076 		log.u_bbr.delRate = low_bnd;
3077 		log.u_bbr.bw_inuse = up_bnd;
3078 		log.u_bbr.rttProp = rack_get_bw(rack);
3079 		log.u_bbr.pkt_epoch = line;
3080 		log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
3081 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3082 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3083 		log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
3084 		log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
3085 		log.u_bbr.cwnd_gain = rack->rc_dragged_bottom;
3086 		log.u_bbr.cwnd_gain <<= 1;
3087 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_rec;
3088 		log.u_bbr.cwnd_gain <<= 1;
3089 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
3090 		log.u_bbr.cwnd_gain <<= 1;
3091 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
3092 		log.u_bbr.lost = rack->r_ctl.rc_loss_count;
3093 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3094 		    &rack->rc_inp->inp_socket->so_rcv,
3095 		    &rack->rc_inp->inp_socket->so_snd,
3096 		    TCP_TIMELY_WORK, 0,
3097 		    0, &log, false, &tv);
3098 	}
3099 }
3100 
3101 static int
3102 rack_bw_can_be_raised(struct tcp_rack *rack, uint64_t cur_bw, uint64_t last_bw_est, uint16_t mult)
3103 {
3104 	/*
3105 	 * Before we increase we need to know if
3106 	 * the estimate just made was less than
3107 	 * our pacing goal (i.e. (cur_bw * mult) > last_bw_est)
3108 	 *
3109 	 * If we already are pacing at a fast enough
3110 	 * rate to push us faster there is no sense of
3111 	 * increasing.
3112 	 *
3113 	 * We first caculate our actual pacing rate (ss or ca multiplier
3114 	 * times our cur_bw).
3115 	 *
3116 	 * Then we take the last measured rate and multipy by our
3117 	 * maximum pacing overage to give us a max allowable rate.
3118 	 *
3119 	 * If our act_rate is smaller than our max_allowable rate
3120 	 * then we should increase. Else we should hold steady.
3121 	 *
3122 	 */
3123 	uint64_t act_rate, max_allow_rate;
3124 
3125 	if (rack_timely_no_stopping)
3126 		return (1);
3127 
3128 	if ((cur_bw == 0) || (last_bw_est == 0)) {
3129 		/*
3130 		 * Initial startup case or
3131 		 * everything is acked case.
3132 		 */
3133 		rack_log_timely(rack,  mult, cur_bw, 0, 0,
3134 				__LINE__, 9);
3135 		return (1);
3136 	}
3137 	if (mult <= 100) {
3138 		/*
3139 		 * We can always pace at or slightly above our rate.
3140 		 */
3141 		rack_log_timely(rack,  mult, cur_bw, 0, 0,
3142 				__LINE__, 9);
3143 		return (1);
3144 	}
3145 	act_rate = cur_bw * (uint64_t)mult;
3146 	act_rate /= 100;
3147 	max_allow_rate = last_bw_est * ((uint64_t)rack_max_per_above + (uint64_t)100);
3148 	max_allow_rate /= 100;
3149 	if (act_rate < max_allow_rate) {
3150 		/*
3151 		 * Here the rate we are actually pacing at
3152 		 * is smaller than 10% above our last measurement.
3153 		 * This means we are pacing below what we would
3154 		 * like to try to achieve (plus some wiggle room).
3155 		 */
3156 		rack_log_timely(rack,  mult, cur_bw, act_rate, max_allow_rate,
3157 				__LINE__, 9);
3158 		return (1);
3159 	} else {
3160 		/*
3161 		 * Here we are already pacing at least rack_max_per_above(10%)
3162 		 * what we are getting back. This indicates most likely
3163 		 * that we are being limited (cwnd/rwnd/app) and can't
3164 		 * get any more b/w. There is no sense of trying to
3165 		 * raise up the pacing rate its not speeding us up
3166 		 * and we already are pacing faster than we are getting.
3167 		 */
3168 		rack_log_timely(rack,  mult, cur_bw, act_rate, max_allow_rate,
3169 				__LINE__, 8);
3170 		return (0);
3171 	}
3172 }
3173 
3174 static void
3175 rack_validate_multipliers_at_or_above100(struct tcp_rack *rack)
3176 {
3177 	/*
3178 	 * When we drag bottom, we want to assure
3179 	 * that no multiplier is below 1.0, if so
3180 	 * we want to restore it to at least that.
3181 	 */
3182 	if (rack->r_ctl.rack_per_of_gp_rec  < 100) {
3183 		/* This is unlikely we usually do not touch recovery */
3184 		rack->r_ctl.rack_per_of_gp_rec = 100;
3185 	}
3186 	if (rack->r_ctl.rack_per_of_gp_ca < 100) {
3187 		rack->r_ctl.rack_per_of_gp_ca = 100;
3188 	}
3189 	if (rack->r_ctl.rack_per_of_gp_ss < 100) {
3190 		rack->r_ctl.rack_per_of_gp_ss = 100;
3191 	}
3192 }
3193 
3194 static void
3195 rack_validate_multipliers_at_or_below_100(struct tcp_rack *rack)
3196 {
3197 	if (rack->r_ctl.rack_per_of_gp_ca > 100) {
3198 		rack->r_ctl.rack_per_of_gp_ca = 100;
3199 	}
3200 	if (rack->r_ctl.rack_per_of_gp_ss > 100) {
3201 		rack->r_ctl.rack_per_of_gp_ss = 100;
3202 	}
3203 }
3204 
3205 static void
3206 rack_increase_bw_mul(struct tcp_rack *rack, int timely_says, uint64_t cur_bw, uint64_t last_bw_est, int override)
3207 {
3208 	int32_t  calc, logged, plus;
3209 
3210 	logged = 0;
3211 
3212 	if (override) {
3213 		/*
3214 		 * override is passed when we are
3215 		 * loosing b/w and making one last
3216 		 * gasp at trying to not loose out
3217 		 * to a new-reno flow.
3218 		 */
3219 		goto extra_boost;
3220 	}
3221 	/* In classic timely we boost by 5x if we have 5 increases in a row, lets not */
3222 	if (rack->rc_gp_incr &&
3223 	    ((rack->rc_gp_timely_inc_cnt + 1) >= RACK_TIMELY_CNT_BOOST)) {
3224 		/*
3225 		 * Reset and get 5 strokes more before the boost. Note
3226 		 * that the count is 0 based so we have to add one.
3227 		 */
3228 extra_boost:
3229 		plus = (uint32_t)rack_gp_increase_per * RACK_TIMELY_CNT_BOOST;
3230 		rack->rc_gp_timely_inc_cnt = 0;
3231 	} else
3232 		plus = (uint32_t)rack_gp_increase_per;
3233 	/* Must be at least 1% increase for true timely increases */
3234 	if ((plus < 1) &&
3235 	    ((rack->r_ctl.rc_rtt_diff <= 0) || (timely_says <= 0)))
3236 		plus = 1;
3237 	if (rack->rc_gp_saw_rec &&
3238 	    (rack->rc_gp_no_rec_chg == 0) &&
3239 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3240 				  rack->r_ctl.rack_per_of_gp_rec)) {
3241 		/* We have been in recovery ding it too */
3242 		calc = rack->r_ctl.rack_per_of_gp_rec + plus;
3243 		if (calc > 0xffff)
3244 			calc = 0xffff;
3245 		logged |= 1;
3246 		rack->r_ctl.rack_per_of_gp_rec = (uint16_t)calc;
3247 		if (rack_per_upper_bound_ss &&
3248 		    (rack->rc_dragged_bottom == 0) &&
3249 		    (rack->r_ctl.rack_per_of_gp_rec > rack_per_upper_bound_ss))
3250 			rack->r_ctl.rack_per_of_gp_rec = rack_per_upper_bound_ss;
3251 	}
3252 	if (rack->rc_gp_saw_ca &&
3253 	    (rack->rc_gp_saw_ss == 0) &&
3254 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3255 				  rack->r_ctl.rack_per_of_gp_ca)) {
3256 		/* In CA */
3257 		calc = rack->r_ctl.rack_per_of_gp_ca + plus;
3258 		if (calc > 0xffff)
3259 			calc = 0xffff;
3260 		logged |= 2;
3261 		rack->r_ctl.rack_per_of_gp_ca = (uint16_t)calc;
3262 		if (rack_per_upper_bound_ca &&
3263 		    (rack->rc_dragged_bottom == 0) &&
3264 		    (rack->r_ctl.rack_per_of_gp_ca > rack_per_upper_bound_ca))
3265 			rack->r_ctl.rack_per_of_gp_ca = rack_per_upper_bound_ca;
3266 	}
3267 	if (rack->rc_gp_saw_ss &&
3268 	    rack_bw_can_be_raised(rack, cur_bw, last_bw_est,
3269 				  rack->r_ctl.rack_per_of_gp_ss)) {
3270 		/* In SS */
3271 		calc = rack->r_ctl.rack_per_of_gp_ss + plus;
3272 		if (calc > 0xffff)
3273 			calc = 0xffff;
3274 		rack->r_ctl.rack_per_of_gp_ss = (uint16_t)calc;
3275 		if (rack_per_upper_bound_ss &&
3276 		    (rack->rc_dragged_bottom == 0) &&
3277 		    (rack->r_ctl.rack_per_of_gp_ss > rack_per_upper_bound_ss))
3278 			rack->r_ctl.rack_per_of_gp_ss = rack_per_upper_bound_ss;
3279 		logged |= 4;
3280 	}
3281 	if (logged &&
3282 	    (rack->rc_gp_incr == 0)){
3283 		/* Go into increment mode */
3284 		rack->rc_gp_incr = 1;
3285 		rack->rc_gp_timely_inc_cnt = 0;
3286 	}
3287 	if (rack->rc_gp_incr &&
3288 	    logged &&
3289 	    (rack->rc_gp_timely_inc_cnt < RACK_TIMELY_CNT_BOOST)) {
3290 		rack->rc_gp_timely_inc_cnt++;
3291 	}
3292 	rack_log_timely(rack,  logged, plus, 0, 0,
3293 			__LINE__, 1);
3294 }
3295 
3296 static uint32_t
3297 rack_get_decrease(struct tcp_rack *rack, uint32_t curper, int32_t rtt_diff)
3298 {
3299 	/*
3300 	 * norm_grad = rtt_diff / minrtt;
3301 	 * new_per = curper * (1 - B * norm_grad)
3302 	 *
3303 	 * B = rack_gp_decrease_per (default 10%)
3304 	 * rtt_dif = input var current rtt-diff
3305 	 * curper = input var current percentage
3306 	 * minrtt = from rack filter
3307 	 *
3308 	 */
3309 	uint64_t perf;
3310 
3311 	perf = (((uint64_t)curper * ((uint64_t)1000000 -
3312 		    ((uint64_t)rack_gp_decrease_per * (uint64_t)10000 *
3313 		     (((uint64_t)rtt_diff * (uint64_t)1000000)/
3314 		      (uint64_t)get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt)))/
3315 		     (uint64_t)1000000)) /
3316 		(uint64_t)1000000);
3317 	if (perf > curper) {
3318 		/* TSNH */
3319 		perf = curper - 1;
3320 	}
3321 	return ((uint32_t)perf);
3322 }
3323 
3324 static uint32_t
3325 rack_decrease_highrtt(struct tcp_rack *rack, uint32_t curper, uint32_t rtt)
3326 {
3327 	/*
3328 	 *                                   highrttthresh
3329 	 * result = curper * (1 - (B * ( 1 -  ------          ))
3330 	 *                                     gp_srtt
3331 	 *
3332 	 * B = rack_gp_decrease_per (default 10%)
3333 	 * highrttthresh = filter_min * rack_gp_rtt_maxmul
3334 	 */
3335 	uint64_t perf;
3336 	uint32_t highrttthresh;
3337 
3338 	highrttthresh = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
3339 
3340 	perf = (((uint64_t)curper * ((uint64_t)1000000 -
3341 				     ((uint64_t)rack_gp_decrease_per * ((uint64_t)1000000 -
3342 					((uint64_t)highrttthresh * (uint64_t)1000000) /
3343 						    (uint64_t)rtt)) / 100)) /(uint64_t)1000000);
3344 	return (perf);
3345 }
3346 
3347 static void
3348 rack_decrease_bw_mul(struct tcp_rack *rack, int timely_says, uint32_t rtt, int32_t rtt_diff)
3349 {
3350 	uint64_t logvar, logvar2, logvar3;
3351 	uint32_t logged, new_per, ss_red, ca_red, rec_red, alt, val;
3352 
3353 	if (rack->rc_gp_incr) {
3354 		/* Turn off increment counting */
3355 		rack->rc_gp_incr = 0;
3356 		rack->rc_gp_timely_inc_cnt = 0;
3357 	}
3358 	ss_red = ca_red = rec_red = 0;
3359 	logged = 0;
3360 	/* Calculate the reduction value */
3361 	if (rtt_diff < 0) {
3362 		rtt_diff *= -1;
3363 	}
3364 	/* Must be at least 1% reduction */
3365 	if (rack->rc_gp_saw_rec && (rack->rc_gp_no_rec_chg == 0)) {
3366 		/* We have been in recovery ding it too */
3367 		if (timely_says == 2) {
3368 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_rec, rtt);
3369 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3370 			if (alt < new_per)
3371 				val = alt;
3372 			else
3373 				val = new_per;
3374 		} else
3375 			 val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3376 		if (rack->r_ctl.rack_per_of_gp_rec > val) {
3377 			rec_red = (rack->r_ctl.rack_per_of_gp_rec - val);
3378 			rack->r_ctl.rack_per_of_gp_rec = (uint16_t)val;
3379 		} else {
3380 			rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
3381 			rec_red = 0;
3382 		}
3383 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_rec)
3384 			rack->r_ctl.rack_per_of_gp_rec = rack_per_lower_bound;
3385 		logged |= 1;
3386 	}
3387 	if (rack->rc_gp_saw_ss) {
3388 		/* Sent in SS */
3389 		if (timely_says == 2) {
3390 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ss, rtt);
3391 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3392 			if (alt < new_per)
3393 				val = alt;
3394 			else
3395 				val = new_per;
3396 		} else
3397 			val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ss, rtt_diff);
3398 		if (rack->r_ctl.rack_per_of_gp_ss > new_per) {
3399 			ss_red = rack->r_ctl.rack_per_of_gp_ss - val;
3400 			rack->r_ctl.rack_per_of_gp_ss = (uint16_t)val;
3401 		} else {
3402 			ss_red = new_per;
3403 			rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
3404 			logvar = new_per;
3405 			logvar <<= 32;
3406 			logvar |= alt;
3407 			logvar2 = (uint32_t)rtt;
3408 			logvar2 <<= 32;
3409 			logvar2 |= (uint32_t)rtt_diff;
3410 			logvar3 = rack_gp_rtt_maxmul;
3411 			logvar3 <<= 32;
3412 			logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3413 			rack_log_timely(rack, timely_says,
3414 					logvar2, logvar3,
3415 					logvar, __LINE__, 10);
3416 		}
3417 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ss)
3418 			rack->r_ctl.rack_per_of_gp_ss = rack_per_lower_bound;
3419 		logged |= 4;
3420 	} else if (rack->rc_gp_saw_ca) {
3421 		/* Sent in CA */
3422 		if (timely_says == 2) {
3423 			new_per = rack_decrease_highrtt(rack, rack->r_ctl.rack_per_of_gp_ca, rtt);
3424 			alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_rec, rtt_diff);
3425 			if (alt < new_per)
3426 				val = alt;
3427 			else
3428 				val = new_per;
3429 		} else
3430 			val = new_per = alt = rack_get_decrease(rack, rack->r_ctl.rack_per_of_gp_ca, rtt_diff);
3431 		if (rack->r_ctl.rack_per_of_gp_ca > val) {
3432 			ca_red = rack->r_ctl.rack_per_of_gp_ca - val;
3433 			rack->r_ctl.rack_per_of_gp_ca = (uint16_t)val;
3434 		} else {
3435 			rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
3436 			ca_red = 0;
3437 			logvar = new_per;
3438 			logvar <<= 32;
3439 			logvar |= alt;
3440 			logvar2 = (uint32_t)rtt;
3441 			logvar2 <<= 32;
3442 			logvar2 |= (uint32_t)rtt_diff;
3443 			logvar3 = rack_gp_rtt_maxmul;
3444 			logvar3 <<= 32;
3445 			logvar3 |= get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3446 			rack_log_timely(rack, timely_says,
3447 					logvar2, logvar3,
3448 					logvar, __LINE__, 10);
3449 		}
3450 		if (rack_per_lower_bound > rack->r_ctl.rack_per_of_gp_ca)
3451 			rack->r_ctl.rack_per_of_gp_ca = rack_per_lower_bound;
3452 		logged |= 2;
3453 	}
3454 	if (rack->rc_gp_timely_dec_cnt < 0x7) {
3455 		rack->rc_gp_timely_dec_cnt++;
3456 		if (rack_timely_dec_clear &&
3457 		    (rack->rc_gp_timely_dec_cnt == rack_timely_dec_clear))
3458 			rack->rc_gp_timely_dec_cnt = 0;
3459 	}
3460 	logvar = ss_red;
3461 	logvar <<= 32;
3462 	logvar |= ca_red;
3463 	rack_log_timely(rack,  logged, rec_red, rack_per_lower_bound, logvar,
3464 			__LINE__, 2);
3465 }
3466 
3467 static void
3468 rack_log_rtt_shrinks(struct tcp_rack *rack, uint32_t us_cts,
3469 		     uint32_t rtt, uint32_t line, uint8_t reas)
3470 {
3471 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
3472 		union tcp_log_stackspecific log;
3473 		struct timeval tv;
3474 
3475 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
3476 		log.u_bbr.flex1 = line;
3477 		log.u_bbr.flex2 = rack->r_ctl.rc_time_probertt_starts;
3478 		log.u_bbr.flex3 = rack->r_ctl.rc_lower_rtt_us_cts;
3479 		log.u_bbr.flex4 = rack->r_ctl.rack_per_of_gp_ss;
3480 		log.u_bbr.flex5 = rtt;
3481 		log.u_bbr.flex6 = rack->rc_highly_buffered;
3482 		log.u_bbr.flex6 <<= 1;
3483 		log.u_bbr.flex6 |= rack->forced_ack;
3484 		log.u_bbr.flex6 <<= 1;
3485 		log.u_bbr.flex6 |= rack->rc_gp_dyn_mul;
3486 		log.u_bbr.flex6 <<= 1;
3487 		log.u_bbr.flex6 |= rack->in_probe_rtt;
3488 		log.u_bbr.flex6 <<= 1;
3489 		log.u_bbr.flex6 |= rack->measure_saw_probe_rtt;
3490 		log.u_bbr.flex7 = rack->r_ctl.rack_per_of_gp_probertt;
3491 		log.u_bbr.pacing_gain = rack->r_ctl.rack_per_of_gp_ca;
3492 		log.u_bbr.cwnd_gain = rack->r_ctl.rack_per_of_gp_rec;
3493 		log.u_bbr.flex8 = reas;
3494 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
3495 		log.u_bbr.delRate = rack_get_bw(rack);
3496 		log.u_bbr.cur_del_rate = rack->r_ctl.rc_highest_us_rtt;
3497 		log.u_bbr.cur_del_rate <<= 32;
3498 		log.u_bbr.cur_del_rate |= rack->r_ctl.rc_lowest_us_rtt;
3499 		log.u_bbr.applimited = rack->r_ctl.rc_time_probertt_entered;
3500 		log.u_bbr.pkts_out = rack->r_ctl.rc_rtt_diff;
3501 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
3502 		log.u_bbr.epoch = rack->r_ctl.rc_gp_srtt;
3503 		log.u_bbr.lt_epoch = rack->r_ctl.rc_prev_gp_srtt;
3504 		log.u_bbr.pkt_epoch = rack->r_ctl.rc_lower_rtt_us_cts;
3505 		log.u_bbr.delivered = rack->r_ctl.rc_target_probertt_flight;
3506 		log.u_bbr.lost = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3507 		log.u_bbr.rttProp = us_cts;
3508 		log.u_bbr.rttProp <<= 32;
3509 		log.u_bbr.rttProp |= rack->r_ctl.rc_entry_gp_rtt;
3510 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
3511 		    &rack->rc_inp->inp_socket->so_rcv,
3512 		    &rack->rc_inp->inp_socket->so_snd,
3513 		    BBR_LOG_RTT_SHRINKS, 0,
3514 		    0, &log, false, &rack->r_ctl.act_rcv_time);
3515 	}
3516 }
3517 
3518 static void
3519 rack_set_prtt_target(struct tcp_rack *rack, uint32_t segsiz, uint32_t rtt)
3520 {
3521 	uint64_t bwdp;
3522 
3523 	bwdp = rack_get_bw(rack);
3524 	bwdp *= (uint64_t)rtt;
3525 	bwdp /= (uint64_t)HPTS_USEC_IN_SEC;
3526 	rack->r_ctl.rc_target_probertt_flight = roundup((uint32_t)bwdp, segsiz);
3527 	if (rack->r_ctl.rc_target_probertt_flight < (segsiz * rack_timely_min_segs)) {
3528 		/*
3529 		 * A window protocol must be able to have 4 packets
3530 		 * outstanding as the floor in order to function
3531 		 * (especially considering delayed ack :D).
3532 		 */
3533 		rack->r_ctl.rc_target_probertt_flight = (segsiz * rack_timely_min_segs);
3534 	}
3535 }
3536 
3537 static void
3538 rack_enter_probertt(struct tcp_rack *rack, uint32_t us_cts)
3539 {
3540 	/**
3541 	 * ProbeRTT is a bit different in rack_pacing than in
3542 	 * BBR. It is like BBR in that it uses the lowering of
3543 	 * the RTT as a signal that we saw something new and
3544 	 * counts from there for how long between. But it is
3545 	 * different in that its quite simple. It does not
3546 	 * play with the cwnd and wait until we get down
3547 	 * to N segments outstanding and hold that for
3548 	 * 200ms. Instead it just sets the pacing reduction
3549 	 * rate to a set percentage (70 by default) and hold
3550 	 * that for a number of recent GP Srtt's.
3551 	 */
3552 	uint32_t segsiz;
3553 
3554 	if (rack->rc_gp_dyn_mul == 0)
3555 		return;
3556 
3557 	if (rack->rc_tp->snd_max == rack->rc_tp->snd_una) {
3558 		/* We are idle */
3559 		return;
3560 	}
3561 	if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
3562 	    SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
3563 		/*
3564 		 * Stop the goodput now, the idea here is
3565 		 * that future measurements with in_probe_rtt
3566 		 * won't register if they are not greater so
3567 		 * we want to get what info (if any) is available
3568 		 * now.
3569 		 */
3570 		rack_do_goodput_measurement(rack->rc_tp, rack,
3571 					    rack->rc_tp->snd_una, __LINE__,
3572 					    RACK_QUALITY_PROBERTT);
3573 	}
3574 	rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
3575 	rack->r_ctl.rc_time_probertt_entered = us_cts;
3576 	segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
3577 		     rack->r_ctl.rc_pace_min_segs);
3578 	rack->in_probe_rtt = 1;
3579 	rack->measure_saw_probe_rtt = 1;
3580 	rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
3581 	rack->r_ctl.rc_time_probertt_starts = 0;
3582 	rack->r_ctl.rc_entry_gp_rtt = rack->r_ctl.rc_gp_srtt;
3583 	if (rack_probertt_use_min_rtt_entry)
3584 		rack_set_prtt_target(rack, segsiz, get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
3585 	else
3586 		rack_set_prtt_target(rack, segsiz, rack->r_ctl.rc_gp_srtt);
3587 	rack_log_rtt_shrinks(rack,  us_cts,  get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3588 			     __LINE__, RACK_RTTS_ENTERPROBE);
3589 }
3590 
3591 static void
3592 rack_exit_probertt(struct tcp_rack *rack, uint32_t us_cts)
3593 {
3594 	struct rack_sendmap *rsm;
3595 	uint32_t segsiz;
3596 
3597 	segsiz = min(ctf_fixed_maxseg(rack->rc_tp),
3598 		     rack->r_ctl.rc_pace_min_segs);
3599 	rack->in_probe_rtt = 0;
3600 	if ((rack->rc_tp->t_flags & TF_GPUTINPROG) &&
3601 	    SEQ_GT(rack->rc_tp->snd_una, rack->rc_tp->gput_seq)) {
3602 		/*
3603 		 * Stop the goodput now, the idea here is
3604 		 * that future measurements with in_probe_rtt
3605 		 * won't register if they are not greater so
3606 		 * we want to get what info (if any) is available
3607 		 * now.
3608 		 */
3609 		rack_do_goodput_measurement(rack->rc_tp, rack,
3610 					    rack->rc_tp->snd_una, __LINE__,
3611 					    RACK_QUALITY_PROBERTT);
3612 	} else if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
3613 		/*
3614 		 * We don't have enough data to make a measurement.
3615 		 * So lets just stop and start here after exiting
3616 		 * probe-rtt. We probably are not interested in
3617 		 * the results anyway.
3618 		 */
3619 		rack->rc_tp->t_flags &= ~TF_GPUTINPROG;
3620 	}
3621 	/*
3622 	 * Measurements through the current snd_max are going
3623 	 * to be limited by the slower pacing rate.
3624 	 *
3625 	 * We need to mark these as app-limited so we
3626 	 * don't collapse the b/w.
3627 	 */
3628 	rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
3629 	if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
3630 		if (rack->r_ctl.rc_app_limited_cnt == 0)
3631 			rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
3632 		else {
3633 			/*
3634 			 * Go out to the end app limited and mark
3635 			 * this new one as next and move the end_appl up
3636 			 * to this guy.
3637 			 */
3638 			if (rack->r_ctl.rc_end_appl)
3639 				rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
3640 			rack->r_ctl.rc_end_appl = rsm;
3641 		}
3642 		rsm->r_flags |= RACK_APP_LIMITED;
3643 		rack->r_ctl.rc_app_limited_cnt++;
3644 	}
3645 	/*
3646 	 * Now, we need to examine our pacing rate multipliers.
3647 	 * If its under 100%, we need to kick it back up to
3648 	 * 100%. We also don't let it be over our "max" above
3649 	 * the actual rate i.e. 100% + rack_clamp_atexit_prtt.
3650 	 * Note setting clamp_atexit_prtt to 0 has the effect
3651 	 * of setting CA/SS to 100% always at exit (which is
3652 	 * the default behavior).
3653 	 */
3654 	if (rack_probertt_clear_is) {
3655 		rack->rc_gp_incr = 0;
3656 		rack->rc_gp_bwred = 0;
3657 		rack->rc_gp_timely_inc_cnt = 0;
3658 		rack->rc_gp_timely_dec_cnt = 0;
3659 	}
3660 	/* Do we do any clamping at exit? */
3661 	if (rack->rc_highly_buffered && rack_atexit_prtt_hbp) {
3662 		rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt_hbp;
3663 		rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt_hbp;
3664 	}
3665 	if ((rack->rc_highly_buffered == 0) && rack_atexit_prtt) {
3666 		rack->r_ctl.rack_per_of_gp_ca = rack_atexit_prtt;
3667 		rack->r_ctl.rack_per_of_gp_ss = rack_atexit_prtt;
3668 	}
3669 	/*
3670 	 * Lets set rtt_diff to 0, so that we will get a "boost"
3671 	 * after exiting.
3672 	 */
3673 	rack->r_ctl.rc_rtt_diff = 0;
3674 
3675 	/* Clear all flags so we start fresh */
3676 	rack->rc_tp->t_bytes_acked = 0;
3677 	rack->rc_tp->ccv->flags &= ~CCF_ABC_SENTAWND;
3678 	/*
3679 	 * If configured to, set the cwnd and ssthresh to
3680 	 * our targets.
3681 	 */
3682 	if (rack_probe_rtt_sets_cwnd) {
3683 		uint64_t ebdp;
3684 		uint32_t setto;
3685 
3686 		/* Set ssthresh so we get into CA once we hit our target */
3687 		if (rack_probertt_use_min_rtt_exit == 1) {
3688 			/* Set to min rtt */
3689 			rack_set_prtt_target(rack, segsiz,
3690 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt));
3691 		} else if (rack_probertt_use_min_rtt_exit == 2) {
3692 			/* Set to current gp rtt */
3693 			rack_set_prtt_target(rack, segsiz,
3694 					     rack->r_ctl.rc_gp_srtt);
3695 		} else if (rack_probertt_use_min_rtt_exit == 3) {
3696 			/* Set to entry gp rtt */
3697 			rack_set_prtt_target(rack, segsiz,
3698 					     rack->r_ctl.rc_entry_gp_rtt);
3699 		} else {
3700 			uint64_t sum;
3701 			uint32_t setval;
3702 
3703 			sum = rack->r_ctl.rc_entry_gp_rtt;
3704 			sum *= 10;
3705 			sum /= (uint64_t)(max(1, rack->r_ctl.rc_gp_srtt));
3706 			if (sum >= 20) {
3707 				/*
3708 				 * A highly buffered path needs
3709 				 * cwnd space for timely to work.
3710 				 * Lets set things up as if
3711 				 * we are heading back here again.
3712 				 */
3713 				setval = rack->r_ctl.rc_entry_gp_rtt;
3714 			} else if (sum >= 15) {
3715 				/*
3716 				 * Lets take the smaller of the
3717 				 * two since we are just somewhat
3718 				 * buffered.
3719 				 */
3720 				setval = rack->r_ctl.rc_gp_srtt;
3721 				if (setval > rack->r_ctl.rc_entry_gp_rtt)
3722 					setval = rack->r_ctl.rc_entry_gp_rtt;
3723 			} else {
3724 				/*
3725 				 * Here we are not highly buffered
3726 				 * and should pick the min we can to
3727 				 * keep from causing loss.
3728 				 */
3729 				setval = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
3730 			}
3731 			rack_set_prtt_target(rack, segsiz,
3732 					     setval);
3733 		}
3734 		if (rack_probe_rtt_sets_cwnd > 1) {
3735 			/* There is a percentage here to boost */
3736 			ebdp = rack->r_ctl.rc_target_probertt_flight;
3737 			ebdp *= rack_probe_rtt_sets_cwnd;
3738 			ebdp /= 100;
3739 			setto = rack->r_ctl.rc_target_probertt_flight + ebdp;
3740 		} else
3741 			setto = rack->r_ctl.rc_target_probertt_flight;
3742 		rack->rc_tp->snd_cwnd = roundup(setto, segsiz);
3743 		if (rack->rc_tp->snd_cwnd < (segsiz * rack_timely_min_segs)) {
3744 			/* Enforce a min */
3745 			rack->rc_tp->snd_cwnd = segsiz * rack_timely_min_segs;
3746 		}
3747 		/* If we set in the cwnd also set the ssthresh point so we are in CA */
3748 		rack->rc_tp->snd_ssthresh = (rack->rc_tp->snd_cwnd - 1);
3749 	}
3750 	rack_log_rtt_shrinks(rack,  us_cts,
3751 			     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3752 			     __LINE__, RACK_RTTS_EXITPROBE);
3753 	/* Clear times last so log has all the info */
3754 	rack->r_ctl.rc_probertt_sndmax_atexit = rack->rc_tp->snd_max;
3755 	rack->r_ctl.rc_time_probertt_entered = us_cts;
3756 	rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
3757 	rack->r_ctl.rc_time_of_last_probertt = us_cts;
3758 }
3759 
3760 static void
3761 rack_check_probe_rtt(struct tcp_rack *rack, uint32_t us_cts)
3762 {
3763 	/* Check in on probe-rtt */
3764 	if (rack->rc_gp_filled == 0) {
3765 		/* We do not do p-rtt unless we have gp measurements */
3766 		return;
3767 	}
3768 	if (rack->in_probe_rtt) {
3769 		uint64_t no_overflow;
3770 		uint32_t endtime, must_stay;
3771 
3772 		if (rack->r_ctl.rc_went_idle_time &&
3773 		    ((us_cts - rack->r_ctl.rc_went_idle_time) > rack_min_probertt_hold)) {
3774 			/*
3775 			 * We went idle during prtt, just exit now.
3776 			 */
3777 			rack_exit_probertt(rack, us_cts);
3778 		} else if (rack_probe_rtt_safety_val &&
3779 		    TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered) &&
3780 		    ((us_cts - rack->r_ctl.rc_time_probertt_entered) > rack_probe_rtt_safety_val)) {
3781 			/*
3782 			 * Probe RTT safety value triggered!
3783 			 */
3784 			rack_log_rtt_shrinks(rack,  us_cts,
3785 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3786 					     __LINE__, RACK_RTTS_SAFETY);
3787 			rack_exit_probertt(rack, us_cts);
3788 		}
3789 		/* Calculate the max we will wait */
3790 		endtime = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_max_drain_wait);
3791 		if (rack->rc_highly_buffered)
3792 			endtime += (rack->r_ctl.rc_gp_srtt * rack_max_drain_hbp);
3793 		/* Calculate the min we must wait */
3794 		must_stay = rack->r_ctl.rc_time_probertt_entered + (rack->r_ctl.rc_gp_srtt * rack_must_drain);
3795 		if ((ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.rc_target_probertt_flight) &&
3796 		    TSTMP_LT(us_cts, endtime)) {
3797 			uint32_t calc;
3798 			/* Do we lower more? */
3799 no_exit:
3800 			if (TSTMP_GT(us_cts, rack->r_ctl.rc_time_probertt_entered))
3801 				calc = us_cts - rack->r_ctl.rc_time_probertt_entered;
3802 			else
3803 				calc = 0;
3804 			calc /= max(rack->r_ctl.rc_gp_srtt, 1);
3805 			if (calc) {
3806 				/* Maybe */
3807 				calc *= rack_per_of_gp_probertt_reduce;
3808 				rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt - calc;
3809 				/* Limit it too */
3810 				if (rack->r_ctl.rack_per_of_gp_probertt < rack_per_of_gp_lowthresh)
3811 					rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_lowthresh;
3812 			}
3813 			/* We must reach target or the time set */
3814 			return;
3815 		}
3816 		if (rack->r_ctl.rc_time_probertt_starts == 0) {
3817 			if ((TSTMP_LT(us_cts, must_stay) &&
3818 			     rack->rc_highly_buffered) ||
3819 			     (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) >
3820 			      rack->r_ctl.rc_target_probertt_flight)) {
3821 				/* We are not past the must_stay time */
3822 				goto no_exit;
3823 			}
3824 			rack_log_rtt_shrinks(rack,  us_cts,
3825 					     get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
3826 					     __LINE__, RACK_RTTS_REACHTARGET);
3827 			rack->r_ctl.rc_time_probertt_starts = us_cts;
3828 			if (rack->r_ctl.rc_time_probertt_starts == 0)
3829 				rack->r_ctl.rc_time_probertt_starts = 1;
3830 			/* Restore back to our rate we want to pace at in prtt */
3831 			rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
3832 		}
3833 		/*
3834 		 * Setup our end time, some number of gp_srtts plus 200ms.
3835 		 */
3836 		no_overflow = ((uint64_t)rack->r_ctl.rc_gp_srtt *
3837 			       (uint64_t)rack_probertt_gpsrtt_cnt_mul);
3838 		if (rack_probertt_gpsrtt_cnt_div)
3839 			endtime = (uint32_t)(no_overflow / (uint64_t)rack_probertt_gpsrtt_cnt_div);
3840 		else
3841 			endtime = 0;
3842 		endtime += rack_min_probertt_hold;
3843 		endtime += rack->r_ctl.rc_time_probertt_starts;
3844 		if (TSTMP_GEQ(us_cts,  endtime)) {
3845 			/* yes, exit probertt */
3846 			rack_exit_probertt(rack, us_cts);
3847 		}
3848 
3849 	} else if ((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= rack_time_between_probertt) {
3850 		/* Go into probertt, its been too long since we went lower */
3851 		rack_enter_probertt(rack, us_cts);
3852 	}
3853 }
3854 
3855 static void
3856 rack_update_multiplier(struct tcp_rack *rack, int32_t timely_says, uint64_t last_bw_est,
3857 		       uint32_t rtt, int32_t rtt_diff)
3858 {
3859 	uint64_t cur_bw, up_bnd, low_bnd, subfr;
3860 	uint32_t losses;
3861 
3862 	if ((rack->rc_gp_dyn_mul == 0) ||
3863 	    (rack->use_fixed_rate) ||
3864 	    (rack->in_probe_rtt) ||
3865 	    (rack->rc_always_pace == 0)) {
3866 		/* No dynamic GP multiplier in play */
3867 		return;
3868 	}
3869 	losses = rack->r_ctl.rc_loss_count - rack->r_ctl.rc_loss_at_start;
3870 	cur_bw = rack_get_bw(rack);
3871 	/* Calculate our up and down range */
3872 	up_bnd = rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_up;
3873 	up_bnd /= 100;
3874 	up_bnd += rack->r_ctl.last_gp_comp_bw;
3875 
3876 	subfr = (uint64_t)rack->r_ctl.last_gp_comp_bw * (uint64_t)rack_gp_per_bw_mul_down;
3877 	subfr /= 100;
3878 	low_bnd = rack->r_ctl.last_gp_comp_bw - subfr;
3879 	if ((timely_says == 2) && (rack->r_ctl.rc_no_push_at_mrtt)) {
3880 		/*
3881 		 * This is the case where our RTT is above
3882 		 * the max target and we have been configured
3883 		 * to just do timely no bonus up stuff in that case.
3884 		 *
3885 		 * There are two configurations, set to 1, and we
3886 		 * just do timely if we are over our max. If its
3887 		 * set above 1 then we slam the multipliers down
3888 		 * to 100 and then decrement per timely.
3889 		 */
3890 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
3891 				__LINE__, 3);
3892 		if (rack->r_ctl.rc_no_push_at_mrtt > 1)
3893 			rack_validate_multipliers_at_or_below_100(rack);
3894 		rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
3895 	} else if ((last_bw_est < low_bnd) && !losses) {
3896 		/*
3897 		 * We are decreasing this is a bit complicated this
3898 		 * means we are loosing ground. This could be
3899 		 * because another flow entered and we are competing
3900 		 * for b/w with it. This will push the RTT up which
3901 		 * makes timely unusable unless we want to get shoved
3902 		 * into a corner and just be backed off (the age
3903 		 * old problem with delay based CC).
3904 		 *
3905 		 * On the other hand if it was a route change we
3906 		 * would like to stay somewhat contained and not
3907 		 * blow out the buffers.
3908 		 */
3909 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
3910 				__LINE__, 3);
3911 		rack->r_ctl.last_gp_comp_bw = cur_bw;
3912 		if (rack->rc_gp_bwred == 0) {
3913 			/* Go into reduction counting */
3914 			rack->rc_gp_bwred = 1;
3915 			rack->rc_gp_timely_dec_cnt = 0;
3916 		}
3917 		if ((rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) ||
3918 		    (timely_says == 0)) {
3919 			/*
3920 			 * Push another time with a faster pacing
3921 			 * to try to gain back (we include override to
3922 			 * get a full raise factor).
3923 			 */
3924 			if ((rack->rc_gp_saw_ca && rack->r_ctl.rack_per_of_gp_ca <= rack_down_raise_thresh) ||
3925 			    (rack->rc_gp_saw_ss && rack->r_ctl.rack_per_of_gp_ss <= rack_down_raise_thresh) ||
3926 			    (timely_says == 0) ||
3927 			    (rack_down_raise_thresh == 0)) {
3928 				/*
3929 				 * Do an override up in b/w if we were
3930 				 * below the threshold or if the threshold
3931 				 * is zero we always do the raise.
3932 				 */
3933 				rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 1);
3934 			} else {
3935 				/* Log it stays the same */
3936 				rack_log_timely(rack,  0, last_bw_est, low_bnd, 0,
3937 						__LINE__, 11);
3938 			}
3939 			rack->rc_gp_timely_dec_cnt++;
3940 			/* We are not incrementing really no-count */
3941 			rack->rc_gp_incr = 0;
3942 			rack->rc_gp_timely_inc_cnt = 0;
3943 		} else {
3944 			/*
3945 			 * Lets just use the RTT
3946 			 * information and give up
3947 			 * pushing.
3948 			 */
3949 			goto use_timely;
3950 		}
3951 	} else if ((timely_says != 2) &&
3952 		    !losses &&
3953 		    (last_bw_est > up_bnd)) {
3954 		/*
3955 		 * We are increasing b/w lets keep going, updating
3956 		 * our b/w and ignoring any timely input, unless
3957 		 * of course we are at our max raise (if there is one).
3958 		 */
3959 
3960 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
3961 				__LINE__, 3);
3962 		rack->r_ctl.last_gp_comp_bw = cur_bw;
3963 		if (rack->rc_gp_saw_ss &&
3964 		    rack_per_upper_bound_ss &&
3965 		     (rack->r_ctl.rack_per_of_gp_ss == rack_per_upper_bound_ss)) {
3966 			    /*
3967 			     * In cases where we can't go higher
3968 			     * we should just use timely.
3969 			     */
3970 			    goto use_timely;
3971 		}
3972 		if (rack->rc_gp_saw_ca &&
3973 		    rack_per_upper_bound_ca &&
3974 		    (rack->r_ctl.rack_per_of_gp_ca == rack_per_upper_bound_ca)) {
3975 			    /*
3976 			     * In cases where we can't go higher
3977 			     * we should just use timely.
3978 			     */
3979 			    goto use_timely;
3980 		}
3981 		rack->rc_gp_bwred = 0;
3982 		rack->rc_gp_timely_dec_cnt = 0;
3983 		/* You get a set number of pushes if timely is trying to reduce */
3984 		if ((rack->rc_gp_incr < rack_timely_max_push_rise) || (timely_says == 0)) {
3985 			rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
3986 		} else {
3987 			/* Log it stays the same */
3988 			rack_log_timely(rack,  0, last_bw_est, up_bnd, 0,
3989 			    __LINE__, 12);
3990 		}
3991 		return;
3992 	} else {
3993 		/*
3994 		 * We are staying between the lower and upper range bounds
3995 		 * so use timely to decide.
3996 		 */
3997 		rack_log_timely(rack,  timely_says, cur_bw, low_bnd, up_bnd,
3998 				__LINE__, 3);
3999 use_timely:
4000 		if (timely_says) {
4001 			rack->rc_gp_incr = 0;
4002 			rack->rc_gp_timely_inc_cnt = 0;
4003 			if ((rack->rc_gp_timely_dec_cnt < rack_timely_max_push_drop) &&
4004 			    !losses &&
4005 			    (last_bw_est < low_bnd)) {
4006 				/* We are loosing ground */
4007 				rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4008 				rack->rc_gp_timely_dec_cnt++;
4009 				/* We are not incrementing really no-count */
4010 				rack->rc_gp_incr = 0;
4011 				rack->rc_gp_timely_inc_cnt = 0;
4012 			} else
4013 				rack_decrease_bw_mul(rack, timely_says, rtt, rtt_diff);
4014 		} else {
4015 			rack->rc_gp_bwred = 0;
4016 			rack->rc_gp_timely_dec_cnt = 0;
4017 			rack_increase_bw_mul(rack, timely_says, cur_bw, last_bw_est, 0);
4018 		}
4019 	}
4020 }
4021 
4022 static int32_t
4023 rack_make_timely_judgement(struct tcp_rack *rack, uint32_t rtt, int32_t rtt_diff, uint32_t prev_rtt)
4024 {
4025 	int32_t timely_says;
4026 	uint64_t log_mult, log_rtt_a_diff;
4027 
4028 	log_rtt_a_diff = rtt;
4029 	log_rtt_a_diff <<= 32;
4030 	log_rtt_a_diff |= (uint32_t)rtt_diff;
4031 	if (rtt >= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) *
4032 		    rack_gp_rtt_maxmul)) {
4033 		/* Reduce the b/w multiplier */
4034 		timely_says = 2;
4035 		log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_maxmul;
4036 		log_mult <<= 32;
4037 		log_mult |= prev_rtt;
4038 		rack_log_timely(rack,  timely_says, log_mult,
4039 				get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4040 				log_rtt_a_diff, __LINE__, 4);
4041 	} else if (rtt <= (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
4042 			   ((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
4043 			    max(rack_gp_rtt_mindiv , 1)))) {
4044 		/* Increase the b/w multiplier */
4045 		log_mult = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) +
4046 			((get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack_gp_rtt_minmul) /
4047 			 max(rack_gp_rtt_mindiv , 1));
4048 		log_mult <<= 32;
4049 		log_mult |= prev_rtt;
4050 		timely_says = 0;
4051 		rack_log_timely(rack,  timely_says, log_mult ,
4052 				get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt),
4053 				log_rtt_a_diff, __LINE__, 5);
4054 	} else {
4055 		/*
4056 		 * Use a gradient to find it the timely gradient
4057 		 * is:
4058 		 * grad = rc_rtt_diff / min_rtt;
4059 		 *
4060 		 * anything below or equal to 0 will be
4061 		 * a increase indication. Anything above
4062 		 * zero is a decrease. Note we take care
4063 		 * of the actual gradient calculation
4064 		 * in the reduction (its not needed for
4065 		 * increase).
4066 		 */
4067 		log_mult = prev_rtt;
4068 		if (rtt_diff <= 0) {
4069 			/*
4070 			 * Rttdiff is less than zero, increase the
4071 			 * b/w multiplier (its 0 or negative)
4072 			 */
4073 			timely_says = 0;
4074 			rack_log_timely(rack,  timely_says, log_mult,
4075 					get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 6);
4076 		} else {
4077 			/* Reduce the b/w multiplier */
4078 			timely_says = 1;
4079 			rack_log_timely(rack,  timely_says, log_mult,
4080 					get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt), log_rtt_a_diff, __LINE__, 7);
4081 		}
4082 	}
4083 	return (timely_says);
4084 }
4085 
4086 static void
4087 rack_do_goodput_measurement(struct tcpcb *tp, struct tcp_rack *rack,
4088 			    tcp_seq th_ack, int line, uint8_t quality)
4089 {
4090 	uint64_t tim, bytes_ps, ltim, stim, utim;
4091 	uint32_t segsiz, bytes, reqbytes, us_cts;
4092 	int32_t gput, new_rtt_diff, timely_says;
4093 	uint64_t  resid_bw, subpart = 0, addpart = 0, srtt;
4094 	int did_add = 0;
4095 
4096 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
4097 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
4098 	if (TSTMP_GEQ(us_cts, tp->gput_ts))
4099 		tim = us_cts - tp->gput_ts;
4100 	else
4101 		tim = 0;
4102 	if (rack->r_ctl.rc_gp_cumack_ts > rack->r_ctl.rc_gp_output_ts)
4103 		stim = rack->r_ctl.rc_gp_cumack_ts - rack->r_ctl.rc_gp_output_ts;
4104 	else
4105 		stim = 0;
4106 	/*
4107 	 * Use the larger of the send time or ack time. This prevents us
4108 	 * from being influenced by ack artifacts to come up with too
4109 	 * high of measurement. Note that since we are spanning over many more
4110 	 * bytes in most of our measurements hopefully that is less likely to
4111 	 * occur.
4112 	 */
4113 	if (tim > stim)
4114 		utim = max(tim, 1);
4115 	else
4116 		utim = max(stim, 1);
4117 	/* Lets get a msec time ltim too for the old stuff */
4118 	ltim = max(1, (utim / HPTS_USEC_IN_MSEC));
4119 	gput = (((uint64_t) (th_ack - tp->gput_seq)) << 3) / ltim;
4120 	reqbytes = min(rc_init_window(rack), (MIN_GP_WIN * segsiz));
4121 	if ((tim == 0) && (stim == 0)) {
4122 		/*
4123 		 * Invalid measurement time, maybe
4124 		 * all on one ack/one send?
4125 		 */
4126 		bytes = 0;
4127 		bytes_ps = 0;
4128 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4129 					   0, 0, 0, 10, __LINE__, NULL, quality);
4130 		goto skip_measurement;
4131 	}
4132 	if (rack->r_ctl.rc_gp_lowrtt == 0xffffffff) {
4133 		/* We never made a us_rtt measurement? */
4134 		bytes = 0;
4135 		bytes_ps = 0;
4136 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4137 					   0, 0, 0, 10, __LINE__, NULL, quality);
4138 		goto skip_measurement;
4139 	}
4140 	/*
4141 	 * Calculate the maximum possible b/w this connection
4142 	 * could have. We base our calculation on the lowest
4143 	 * rtt we have seen during the measurement and the
4144 	 * largest rwnd the client has given us in that time. This
4145 	 * forms a BDP that is the maximum that we could ever
4146 	 * get to the client. Anything larger is not valid.
4147 	 *
4148 	 * I originally had code here that rejected measurements
4149 	 * where the time was less than 1/2 the latest us_rtt.
4150 	 * But after thinking on that I realized its wrong since
4151 	 * say you had a 150Mbps or even 1Gbps link, and you
4152 	 * were a long way away.. example I am in Europe (100ms rtt)
4153 	 * talking to my 1Gbps link in S.C. Now measuring say 150,000
4154 	 * bytes my time would be 1.2ms, and yet my rtt would say
4155 	 * the measurement was invalid the time was < 50ms. The
4156 	 * same thing is true for 150Mb (8ms of time).
4157 	 *
4158 	 * A better way I realized is to look at what the maximum
4159 	 * the connection could possibly do. This is gated on
4160 	 * the lowest RTT we have seen and the highest rwnd.
4161 	 * We should in theory never exceed that, if we are
4162 	 * then something on the path is storing up packets
4163 	 * and then feeding them all at once to our endpoint
4164 	 * messing up our measurement.
4165 	 */
4166 	rack->r_ctl.last_max_bw = rack->r_ctl.rc_gp_high_rwnd;
4167 	rack->r_ctl.last_max_bw *= HPTS_USEC_IN_SEC;
4168 	rack->r_ctl.last_max_bw /= rack->r_ctl.rc_gp_lowrtt;
4169 	if (SEQ_LT(th_ack, tp->gput_seq)) {
4170 		/* No measurement can be made */
4171 		bytes = 0;
4172 		bytes_ps = 0;
4173 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4174 					   0, 0, 0, 10, __LINE__, NULL, quality);
4175 		goto skip_measurement;
4176 	} else
4177 		bytes = (th_ack - tp->gput_seq);
4178 	bytes_ps = (uint64_t)bytes;
4179 	/*
4180 	 * Don't measure a b/w for pacing unless we have gotten at least
4181 	 * an initial windows worth of data in this measurement interval.
4182 	 *
4183 	 * Small numbers of bytes get badly influenced by delayed ack and
4184 	 * other artifacts. Note we take the initial window or our
4185 	 * defined minimum GP (defaulting to 10 which hopefully is the
4186 	 * IW).
4187 	 */
4188 	if (rack->rc_gp_filled == 0) {
4189 		/*
4190 		 * The initial estimate is special. We
4191 		 * have blasted out an IW worth of packets
4192 		 * without a real valid ack ts results. We
4193 		 * then setup the app_limited_needs_set flag,
4194 		 * this should get the first ack in (probably 2
4195 		 * MSS worth) to be recorded as the timestamp.
4196 		 * We thus allow a smaller number of bytes i.e.
4197 		 * IW - 2MSS.
4198 		 */
4199 		reqbytes -= (2 * segsiz);
4200 		/* Also lets fill previous for our first measurement to be neutral */
4201 		rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
4202 	}
4203 	if ((bytes_ps < reqbytes) || rack->app_limited_needs_set) {
4204 		rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4205 					   rack->r_ctl.rc_app_limited_cnt,
4206 					   0, 0, 10, __LINE__, NULL, quality);
4207 		goto skip_measurement;
4208 	}
4209 	/*
4210 	 * We now need to calculate the Timely like status so
4211 	 * we can update (possibly) the b/w multipliers.
4212 	 */
4213 	new_rtt_diff = (int32_t)rack->r_ctl.rc_gp_srtt - (int32_t)rack->r_ctl.rc_prev_gp_srtt;
4214 	if (rack->rc_gp_filled == 0) {
4215 		/* No previous reading */
4216 		rack->r_ctl.rc_rtt_diff = new_rtt_diff;
4217 	} else {
4218 		if (rack->measure_saw_probe_rtt == 0) {
4219 			/*
4220 			 * We don't want a probertt to be counted
4221 			 * since it will be negative incorrectly. We
4222 			 * expect to be reducing the RTT when we
4223 			 * pace at a slower rate.
4224 			 */
4225 			rack->r_ctl.rc_rtt_diff -= (rack->r_ctl.rc_rtt_diff / 8);
4226 			rack->r_ctl.rc_rtt_diff += (new_rtt_diff / 8);
4227 		}
4228 	}
4229 	timely_says = rack_make_timely_judgement(rack,
4230 		rack->r_ctl.rc_gp_srtt,
4231 		rack->r_ctl.rc_rtt_diff,
4232 	        rack->r_ctl.rc_prev_gp_srtt
4233 		);
4234 	bytes_ps *= HPTS_USEC_IN_SEC;
4235 	bytes_ps /= utim;
4236 	if (bytes_ps > rack->r_ctl.last_max_bw) {
4237 		/*
4238 		 * Something is on path playing
4239 		 * since this b/w is not possible based
4240 		 * on our BDP (highest rwnd and lowest rtt
4241 		 * we saw in the measurement window).
4242 		 *
4243 		 * Another option here would be to
4244 		 * instead skip the measurement.
4245 		 */
4246 		rack_log_pacing_delay_calc(rack, bytes, reqbytes,
4247 					   bytes_ps, rack->r_ctl.last_max_bw, 0,
4248 					   11, __LINE__, NULL, quality);
4249 		bytes_ps = rack->r_ctl.last_max_bw;
4250 	}
4251 	/* We store gp for b/w in bytes per second */
4252 	if (rack->rc_gp_filled == 0) {
4253 		/* Initial measurement */
4254 		if (bytes_ps) {
4255 			rack->r_ctl.gp_bw = bytes_ps;
4256 			rack->rc_gp_filled = 1;
4257 			rack->r_ctl.num_measurements = 1;
4258 			rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
4259 		} else {
4260 			rack_log_pacing_delay_calc(rack, bytes_ps, reqbytes,
4261 						   rack->r_ctl.rc_app_limited_cnt,
4262 						   0, 0, 10, __LINE__, NULL, quality);
4263 		}
4264 		if (tcp_in_hpts(rack->rc_inp) &&
4265 		    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
4266 			/*
4267 			 * Ok we can't trust the pacer in this case
4268 			 * where we transition from un-paced to paced.
4269 			 * Or for that matter when the burst mitigation
4270 			 * was making a wild guess and got it wrong.
4271 			 * Stop the pacer and clear up all the aggregate
4272 			 * delays etc.
4273 			 */
4274 			tcp_hpts_remove(rack->rc_inp);
4275 			rack->r_ctl.rc_hpts_flags = 0;
4276 			rack->r_ctl.rc_last_output_to = 0;
4277 		}
4278 		did_add = 2;
4279 	} else if (rack->r_ctl.num_measurements < RACK_REQ_AVG) {
4280 		/* Still a small number run an average */
4281 		rack->r_ctl.gp_bw += bytes_ps;
4282 		addpart = rack->r_ctl.num_measurements;
4283 		rack->r_ctl.num_measurements++;
4284 		if (rack->r_ctl.num_measurements >= RACK_REQ_AVG) {
4285 			/* We have collected enough to move forward */
4286 			rack->r_ctl.gp_bw /= (uint64_t)rack->r_ctl.num_measurements;
4287 		}
4288 		did_add = 3;
4289 	} else {
4290 		/*
4291 		 * We want to take 1/wma of the goodput and add in to 7/8th
4292 		 * of the old value weighted by the srtt. So if your measurement
4293 		 * period is say 2 SRTT's long you would get 1/4 as the
4294 		 * value, if it was like 1/2 SRTT then you would get 1/16th.
4295 		 *
4296 		 * But we must be careful not to take too much i.e. if the
4297 		 * srtt is say 20ms and the measurement is taken over
4298 		 * 400ms our weight would be 400/20 i.e. 20. On the
4299 		 * other hand if we get a measurement over 1ms with a
4300 		 * 10ms rtt we only want to take a much smaller portion.
4301 		 */
4302 		if (rack->r_ctl.num_measurements < 0xff) {
4303 			rack->r_ctl.num_measurements++;
4304 		}
4305 		srtt = (uint64_t)tp->t_srtt;
4306 		if (srtt == 0) {
4307 			/*
4308 			 * Strange why did t_srtt go back to zero?
4309 			 */
4310 			if (rack->r_ctl.rc_rack_min_rtt)
4311 				srtt = rack->r_ctl.rc_rack_min_rtt;
4312 			else
4313 				srtt = HPTS_USEC_IN_MSEC;
4314 		}
4315 		/*
4316 		 * XXXrrs: Note for reviewers, in playing with
4317 		 * dynamic pacing I discovered this GP calculation
4318 		 * as done originally leads to some undesired results.
4319 		 * Basically you can get longer measurements contributing
4320 		 * too much to the WMA. Thus I changed it if you are doing
4321 		 * dynamic adjustments to only do the aportioned adjustment
4322 		 * if we have a very small (time wise) measurement. Longer
4323 		 * measurements just get there weight (defaulting to 1/8)
4324 		 * add to the WMA. We may want to think about changing
4325 		 * this to always do that for both sides i.e. dynamic
4326 		 * and non-dynamic... but considering lots of folks
4327 		 * were playing with this I did not want to change the
4328 		 * calculation per.se. without your thoughts.. Lawerence?
4329 		 * Peter??
4330 		 */
4331 		if (rack->rc_gp_dyn_mul == 0) {
4332 			subpart = rack->r_ctl.gp_bw * utim;
4333 			subpart /= (srtt * 8);
4334 			if (subpart < (rack->r_ctl.gp_bw / 2)) {
4335 				/*
4336 				 * The b/w update takes no more
4337 				 * away then 1/2 our running total
4338 				 * so factor it in.
4339 				 */
4340 				addpart = bytes_ps * utim;
4341 				addpart /= (srtt * 8);
4342 			} else {
4343 				/*
4344 				 * Don't allow a single measurement
4345 				 * to account for more than 1/2 of the
4346 				 * WMA. This could happen on a retransmission
4347 				 * where utim becomes huge compared to
4348 				 * srtt (multiple retransmissions when using
4349 				 * the sending rate which factors in all the
4350 				 * transmissions from the first one).
4351 				 */
4352 				subpart = rack->r_ctl.gp_bw / 2;
4353 				addpart = bytes_ps / 2;
4354 			}
4355 			resid_bw = rack->r_ctl.gp_bw - subpart;
4356 			rack->r_ctl.gp_bw = resid_bw + addpart;
4357 			did_add = 1;
4358 		} else {
4359 			if ((utim / srtt) <= 1) {
4360 				/*
4361 				 * The b/w update was over a small period
4362 				 * of time. The idea here is to prevent a small
4363 				 * measurement time period from counting
4364 				 * too much. So we scale it based on the
4365 				 * time so it attributes less than 1/rack_wma_divisor
4366 				 * of its measurement.
4367 				 */
4368 				subpart = rack->r_ctl.gp_bw * utim;
4369 				subpart /= (srtt * rack_wma_divisor);
4370 				addpart = bytes_ps * utim;
4371 				addpart /= (srtt * rack_wma_divisor);
4372 			} else {
4373 				/*
4374 				 * The scaled measurement was long
4375 				 * enough so lets just add in the
4376 				 * portion of the measurement i.e. 1/rack_wma_divisor
4377 				 */
4378 				subpart = rack->r_ctl.gp_bw / rack_wma_divisor;
4379 				addpart = bytes_ps / rack_wma_divisor;
4380 			}
4381 			if ((rack->measure_saw_probe_rtt == 0) ||
4382 		            (bytes_ps > rack->r_ctl.gp_bw)) {
4383 				/*
4384 				 * For probe-rtt we only add it in
4385 				 * if its larger, all others we just
4386 				 * add in.
4387 				 */
4388 				did_add = 1;
4389 				resid_bw = rack->r_ctl.gp_bw - subpart;
4390 				rack->r_ctl.gp_bw = resid_bw + addpart;
4391 			}
4392 		}
4393 	}
4394 	if ((rack->gp_ready == 0) &&
4395 	    (rack->r_ctl.num_measurements >= rack->r_ctl.req_measurements)) {
4396 		/* We have enough measurements now */
4397 		rack->gp_ready = 1;
4398 		rack_set_cc_pacing(rack);
4399 		if (rack->defer_options)
4400 			rack_apply_deferred_options(rack);
4401 	}
4402 	rack_log_pacing_delay_calc(rack, subpart, addpart, bytes_ps, stim,
4403 				   rack_get_bw(rack), 22, did_add, NULL, quality);
4404 	/* We do not update any multipliers if we are in or have seen a probe-rtt */
4405 	if ((rack->measure_saw_probe_rtt == 0) && rack->rc_gp_rtt_set)
4406 		rack_update_multiplier(rack, timely_says, bytes_ps,
4407 				       rack->r_ctl.rc_gp_srtt,
4408 				       rack->r_ctl.rc_rtt_diff);
4409 	rack_log_pacing_delay_calc(rack, bytes, tim, bytes_ps, stim,
4410 				   rack_get_bw(rack), 3, line, NULL, quality);
4411 	/* reset the gp srtt and setup the new prev */
4412 	rack->r_ctl.rc_prev_gp_srtt = rack->r_ctl.rc_gp_srtt;
4413 	/* Record the lost count for the next measurement */
4414 	rack->r_ctl.rc_loss_at_start = rack->r_ctl.rc_loss_count;
4415 	/*
4416 	 * We restart our diffs based on the gpsrtt in the
4417 	 * measurement window.
4418 	 */
4419 	rack->rc_gp_rtt_set = 0;
4420 	rack->rc_gp_saw_rec = 0;
4421 	rack->rc_gp_saw_ca = 0;
4422 	rack->rc_gp_saw_ss = 0;
4423 	rack->rc_dragged_bottom = 0;
4424 skip_measurement:
4425 
4426 #ifdef STATS
4427 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_GPUT,
4428 				 gput);
4429 	/*
4430 	 * XXXLAS: This is a temporary hack, and should be
4431 	 * chained off VOI_TCP_GPUT when stats(9) grows an
4432 	 * API to deal with chained VOIs.
4433 	 */
4434 	if (tp->t_stats_gput_prev > 0)
4435 		stats_voi_update_abs_s32(tp->t_stats,
4436 					 VOI_TCP_GPUT_ND,
4437 					 ((gput - tp->t_stats_gput_prev) * 100) /
4438 					 tp->t_stats_gput_prev);
4439 #endif
4440 	tp->t_flags &= ~TF_GPUTINPROG;
4441 	tp->t_stats_gput_prev = gput;
4442 	/*
4443 	 * Now are we app limited now and there is space from where we
4444 	 * were to where we want to go?
4445 	 *
4446 	 * We don't do the other case i.e. non-applimited here since
4447 	 * the next send will trigger us picking up the missing data.
4448 	 */
4449 	if (rack->r_ctl.rc_first_appl &&
4450 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
4451 	    rack->r_ctl.rc_app_limited_cnt &&
4452 	    (SEQ_GT(rack->r_ctl.rc_first_appl->r_start, th_ack)) &&
4453 	    ((rack->r_ctl.rc_first_appl->r_end - th_ack) >
4454 	     max(rc_init_window(rack), (MIN_GP_WIN * segsiz)))) {
4455 		/*
4456 		 * Yep there is enough outstanding to make a measurement here.
4457 		 */
4458 		struct rack_sendmap *rsm, fe;
4459 
4460 		rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
4461 		rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
4462 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
4463 		rack->app_limited_needs_set = 0;
4464 		tp->gput_seq = th_ack;
4465 		if (rack->in_probe_rtt)
4466 			rack->measure_saw_probe_rtt = 1;
4467 		else if ((rack->measure_saw_probe_rtt) &&
4468 			 (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
4469 			rack->measure_saw_probe_rtt = 0;
4470 		if ((rack->r_ctl.rc_first_appl->r_end - th_ack) >= rack_get_measure_window(tp, rack)) {
4471 			/* There is a full window to gain info from */
4472 			tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
4473 		} else {
4474 			/* We can only measure up to the applimited point */
4475 			tp->gput_ack = tp->gput_seq + (rack->r_ctl.rc_first_appl->r_end - th_ack);
4476 			if ((tp->gput_ack - tp->gput_seq) < (MIN_GP_WIN * segsiz)) {
4477 				/*
4478 				 * We don't have enough to make a measurement.
4479 				 */
4480 				tp->t_flags &= ~TF_GPUTINPROG;
4481 				rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
4482 							   0, 0, 0, 6, __LINE__, NULL, quality);
4483 				return;
4484 			}
4485 		}
4486 		if (tp->t_state >= TCPS_FIN_WAIT_1) {
4487 			/*
4488 			 * We will get no more data into the SB
4489 			 * this means we need to have the data available
4490 			 * before we start a measurement.
4491 			 */
4492 			if (sbavail(&tp->t_inpcb->inp_socket->so_snd) < (tp->gput_ack - tp->gput_seq)) {
4493 				/* Nope not enough data. */
4494 				return;
4495 			}
4496 		}
4497 		tp->t_flags |= TF_GPUTINPROG;
4498 		/*
4499 		 * Now we need to find the timestamp of the send at tp->gput_seq
4500 		 * for the send based measurement.
4501 		 */
4502 		fe.r_start = tp->gput_seq;
4503 		rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
4504 		if (rsm) {
4505 			/* Ok send-based limit is set */
4506 			if (SEQ_LT(rsm->r_start, tp->gput_seq)) {
4507 				/*
4508 				 * Move back to include the earlier part
4509 				 * so our ack time lines up right (this may
4510 				 * make an overlapping measurement but thats
4511 				 * ok).
4512 				 */
4513 				tp->gput_seq = rsm->r_start;
4514 			}
4515 			if (rsm->r_flags & RACK_ACKED)
4516 				tp->gput_ts = (uint32_t)rsm->r_ack_arrival;
4517 			else
4518 				rack->app_limited_needs_set = 1;
4519 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
4520 		} else {
4521 			/*
4522 			 * If we don't find the rsm due to some
4523 			 * send-limit set the current time, which
4524 			 * basically disables the send-limit.
4525 			 */
4526 			struct timeval tv;
4527 
4528 			microuptime(&tv);
4529 			rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
4530 		}
4531 		rack_log_pacing_delay_calc(rack,
4532 					   tp->gput_seq,
4533 					   tp->gput_ack,
4534 					   (uint64_t)rsm,
4535 					   tp->gput_ts,
4536 					   rack->r_ctl.rc_app_limited_cnt,
4537 					   9,
4538 					   __LINE__, NULL, quality);
4539 	}
4540 }
4541 
4542 /*
4543  * CC wrapper hook functions
4544  */
4545 static void
4546 rack_ack_received(struct tcpcb *tp, struct tcp_rack *rack, uint32_t th_ack, uint16_t nsegs,
4547     uint16_t type, int32_t recovery)
4548 {
4549 	uint32_t prior_cwnd, acked;
4550 	struct tcp_log_buffer *lgb = NULL;
4551 	uint8_t labc_to_use, quality;
4552 
4553 	INP_WLOCK_ASSERT(tp->t_inpcb);
4554 	tp->ccv->nsegs = nsegs;
4555 	acked = tp->ccv->bytes_this_ack = (th_ack - tp->snd_una);
4556 	if ((recovery) && (rack->r_ctl.rc_early_recovery_segs)) {
4557 		uint32_t max;
4558 
4559 		max = rack->r_ctl.rc_early_recovery_segs * ctf_fixed_maxseg(tp);
4560 		if (tp->ccv->bytes_this_ack > max) {
4561 			tp->ccv->bytes_this_ack = max;
4562 		}
4563 	}
4564 #ifdef STATS
4565 	stats_voi_update_abs_s32(tp->t_stats, VOI_TCP_CALCFRWINDIFF,
4566 	    ((int32_t)rack->r_ctl.cwnd_to_use) - tp->snd_wnd);
4567 #endif
4568 	quality = RACK_QUALITY_NONE;
4569 	if ((tp->t_flags & TF_GPUTINPROG) &&
4570 	    rack_enough_for_measurement(tp, rack, th_ack, &quality)) {
4571 		/* Measure the Goodput */
4572 		rack_do_goodput_measurement(tp, rack, th_ack, __LINE__, quality);
4573 #ifdef NETFLIX_PEAKRATE
4574 		if ((type == CC_ACK) &&
4575 		    (tp->t_maxpeakrate)) {
4576 			/*
4577 			 * We update t_peakrate_thr. This gives us roughly
4578 			 * one update per round trip time. Note
4579 			 * it will only be used if pace_always is off i.e
4580 			 * we don't do this for paced flows.
4581 			 */
4582 			rack_update_peakrate_thr(tp);
4583 		}
4584 #endif
4585 	}
4586 	/* Which way our we limited, if not cwnd limited no advance in CA */
4587 	if (tp->snd_cwnd <= tp->snd_wnd)
4588 		tp->ccv->flags |= CCF_CWND_LIMITED;
4589 	else
4590 		tp->ccv->flags &= ~CCF_CWND_LIMITED;
4591 	if (tp->snd_cwnd > tp->snd_ssthresh) {
4592 		tp->t_bytes_acked += min(tp->ccv->bytes_this_ack,
4593 			 nsegs * V_tcp_abc_l_var * ctf_fixed_maxseg(tp));
4594 		/* For the setting of a window past use the actual scwnd we are using */
4595 		if (tp->t_bytes_acked >= rack->r_ctl.cwnd_to_use) {
4596 			tp->t_bytes_acked -= rack->r_ctl.cwnd_to_use;
4597 			tp->ccv->flags |= CCF_ABC_SENTAWND;
4598 		}
4599 	} else {
4600 		tp->ccv->flags &= ~CCF_ABC_SENTAWND;
4601 		tp->t_bytes_acked = 0;
4602 	}
4603 	prior_cwnd = tp->snd_cwnd;
4604 	if ((recovery == 0) || (rack_max_abc_post_recovery == 0) || rack->r_use_labc_for_rec ||
4605 	    (rack_client_low_buf && (rack->client_bufferlvl < rack_client_low_buf)))
4606 		labc_to_use = rack->rc_labc;
4607 	else
4608 		labc_to_use = rack_max_abc_post_recovery;
4609 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
4610 		union tcp_log_stackspecific log;
4611 		struct timeval tv;
4612 
4613 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
4614 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
4615 		log.u_bbr.flex1 = th_ack;
4616 		log.u_bbr.flex2 = tp->ccv->flags;
4617 		log.u_bbr.flex3 = tp->ccv->bytes_this_ack;
4618 		log.u_bbr.flex4 = tp->ccv->nsegs;
4619 		log.u_bbr.flex5 = labc_to_use;
4620 		log.u_bbr.flex6 = prior_cwnd;
4621 		log.u_bbr.flex7 = V_tcp_do_newsack;
4622 		log.u_bbr.flex8 = 1;
4623 		lgb = tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
4624 				     0, &log, false, NULL, NULL, 0, &tv);
4625 	}
4626 	if (CC_ALGO(tp)->ack_received != NULL) {
4627 		/* XXXLAS: Find a way to live without this */
4628 		tp->ccv->curack = th_ack;
4629 		tp->ccv->labc = labc_to_use;
4630 		tp->ccv->flags |= CCF_USE_LOCAL_ABC;
4631 		CC_ALGO(tp)->ack_received(tp->ccv, type);
4632 	}
4633 	if (lgb) {
4634 		lgb->tlb_stackinfo.u_bbr.flex6 = tp->snd_cwnd;
4635 	}
4636 	if (rack->r_must_retran) {
4637 		if (SEQ_GEQ(th_ack, rack->r_ctl.rc_snd_max_at_rto)) {
4638 			/*
4639 			 * We now are beyond the rxt point so lets disable
4640 			 * the flag.
4641 			 */
4642 			rack->r_ctl.rc_out_at_rto = 0;
4643 			rack->r_must_retran = 0;
4644 		} else if ((prior_cwnd + ctf_fixed_maxseg(tp)) <= tp->snd_cwnd) {
4645 			/*
4646 			 * Only decrement the rc_out_at_rto if the cwnd advances
4647 			 * at least a whole segment. Otherwise next time the peer
4648 			 * acks, we won't be able to send this generaly happens
4649 			 * when we are in Congestion Avoidance.
4650 			 */
4651 			if (acked <= rack->r_ctl.rc_out_at_rto){
4652 				rack->r_ctl.rc_out_at_rto -= acked;
4653 			} else {
4654 				rack->r_ctl.rc_out_at_rto = 0;
4655 			}
4656 		}
4657 	}
4658 #ifdef STATS
4659 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_LCWIN, rack->r_ctl.cwnd_to_use);
4660 #endif
4661 	if (rack->r_ctl.rc_rack_largest_cwnd < rack->r_ctl.cwnd_to_use) {
4662 		rack->r_ctl.rc_rack_largest_cwnd = rack->r_ctl.cwnd_to_use;
4663 	}
4664 #ifdef NETFLIX_PEAKRATE
4665 	/* we enforce max peak rate if it is set and we are not pacing */
4666 	if ((rack->rc_always_pace == 0) &&
4667 	    tp->t_peakrate_thr &&
4668 	    (tp->snd_cwnd > tp->t_peakrate_thr)) {
4669 		tp->snd_cwnd = tp->t_peakrate_thr;
4670 	}
4671 #endif
4672 }
4673 
4674 static void
4675 tcp_rack_partialack(struct tcpcb *tp)
4676 {
4677 	struct tcp_rack *rack;
4678 
4679 	rack = (struct tcp_rack *)tp->t_fb_ptr;
4680 	INP_WLOCK_ASSERT(tp->t_inpcb);
4681 	/*
4682 	 * If we are doing PRR and have enough
4683 	 * room to send <or> we are pacing and prr
4684 	 * is disabled we will want to see if we
4685 	 * can send data (by setting r_wanted_output to
4686 	 * true).
4687 	 */
4688 	if ((rack->r_ctl.rc_prr_sndcnt > 0) ||
4689 	    rack->rack_no_prr)
4690 		rack->r_wanted_output = 1;
4691 }
4692 
4693 static void
4694 rack_post_recovery(struct tcpcb *tp, uint32_t th_ack)
4695 {
4696 	struct tcp_rack *rack;
4697 	uint32_t orig_cwnd;
4698 
4699 	orig_cwnd = tp->snd_cwnd;
4700 	INP_WLOCK_ASSERT(tp->t_inpcb);
4701 	rack = (struct tcp_rack *)tp->t_fb_ptr;
4702 	/* only alert CC if we alerted when we entered */
4703 	if (CC_ALGO(tp)->post_recovery != NULL) {
4704 		tp->ccv->curack = th_ack;
4705 		CC_ALGO(tp)->post_recovery(tp->ccv);
4706 		if (tp->snd_cwnd < tp->snd_ssthresh) {
4707 			/*
4708 			 * Rack has burst control and pacing
4709 			 * so lets not set this any lower than
4710 			 * snd_ssthresh per RFC-6582 (option 2).
4711 			 */
4712 			tp->snd_cwnd = tp->snd_ssthresh;
4713 		}
4714 	}
4715 	if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
4716 		union tcp_log_stackspecific log;
4717 		struct timeval tv;
4718 
4719 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
4720 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
4721 		log.u_bbr.flex1 = th_ack;
4722 		log.u_bbr.flex2 = tp->ccv->flags;
4723 		log.u_bbr.flex3 = tp->ccv->bytes_this_ack;
4724 		log.u_bbr.flex4 = tp->ccv->nsegs;
4725 		log.u_bbr.flex5 = V_tcp_abc_l_var;
4726 		log.u_bbr.flex6 = orig_cwnd;
4727 		log.u_bbr.flex7 = V_tcp_do_newsack;
4728 		log.u_bbr.pkts_out = rack->r_ctl.rc_prr_sndcnt;
4729 		log.u_bbr.flex8 = 2;
4730 		tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
4731 			       0, &log, false, NULL, NULL, 0, &tv);
4732 	}
4733 	if ((rack->rack_no_prr == 0) &&
4734 	    (rack->no_prr_addback == 0) &&
4735 	    (rack->r_ctl.rc_prr_sndcnt > 0)) {
4736 		/*
4737 		 * Suck the next prr cnt back into cwnd, but
4738 		 * only do that if we are not application limited.
4739 		 */
4740 		if (ctf_outstanding(tp) <= sbavail(&(tp->t_inpcb->inp_socket->so_snd))) {
4741 			/*
4742 			 * We are allowed to add back to the cwnd the amount we did
4743 			 * not get out if:
4744 			 * a) no_prr_addback is off.
4745 			 * b) we are not app limited
4746 			 * c) we are doing prr
4747 			 * <and>
4748 			 * d) it is bounded by rack_prr_addbackmax (if addback is 0, then none).
4749 			 */
4750 			tp->snd_cwnd += min((ctf_fixed_maxseg(tp) * rack_prr_addbackmax),
4751 					    rack->r_ctl.rc_prr_sndcnt);
4752 		}
4753 		rack->r_ctl.rc_prr_sndcnt = 0;
4754 		rack_log_to_prr(rack, 1, 0, __LINE__);
4755 	}
4756 	rack_log_to_prr(rack, 14, orig_cwnd, __LINE__);
4757 	tp->snd_recover = tp->snd_una;
4758 	if (rack->r_ctl.dsack_persist) {
4759 		rack->r_ctl.dsack_persist--;
4760 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
4761 			rack->r_ctl.num_dsack = 0;
4762 		}
4763 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
4764 	}
4765 	EXIT_RECOVERY(tp->t_flags);
4766 }
4767 
4768 static void
4769 rack_cong_signal(struct tcpcb *tp, uint32_t type, uint32_t ack, int line)
4770 {
4771 	struct tcp_rack *rack;
4772 	uint32_t ssthresh_enter, cwnd_enter, in_rec_at_entry, orig_cwnd;
4773 
4774 	INP_WLOCK_ASSERT(tp->t_inpcb);
4775 #ifdef STATS
4776 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_CSIG, type);
4777 #endif
4778 	if (IN_RECOVERY(tp->t_flags) == 0) {
4779 		in_rec_at_entry = 0;
4780 		ssthresh_enter = tp->snd_ssthresh;
4781 		cwnd_enter = tp->snd_cwnd;
4782 	} else
4783 		in_rec_at_entry = 1;
4784 	rack = (struct tcp_rack *)tp->t_fb_ptr;
4785 	switch (type) {
4786 	case CC_NDUPACK:
4787 		tp->t_flags &= ~TF_WASFRECOVERY;
4788 		tp->t_flags &= ~TF_WASCRECOVERY;
4789 		if (!IN_FASTRECOVERY(tp->t_flags)) {
4790 			rack->r_ctl.rc_prr_delivered = 0;
4791 			rack->r_ctl.rc_prr_out = 0;
4792 			if (rack->rack_no_prr == 0) {
4793 				rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
4794 				rack_log_to_prr(rack, 2, in_rec_at_entry, line);
4795 			}
4796 			rack->r_ctl.rc_prr_recovery_fs = tp->snd_max - tp->snd_una;
4797 			tp->snd_recover = tp->snd_max;
4798 			if (tp->t_flags2 & TF2_ECN_PERMIT)
4799 				tp->t_flags2 |= TF2_ECN_SND_CWR;
4800 		}
4801 		break;
4802 	case CC_ECN:
4803 		if (!IN_CONGRECOVERY(tp->t_flags) ||
4804 		    /*
4805 		     * Allow ECN reaction on ACK to CWR, if
4806 		     * that data segment was also CE marked.
4807 		     */
4808 		    SEQ_GEQ(ack, tp->snd_recover)) {
4809 			EXIT_CONGRECOVERY(tp->t_flags);
4810 			KMOD_TCPSTAT_INC(tcps_ecn_rcwnd);
4811 			tp->snd_recover = tp->snd_max + 1;
4812 			if (tp->t_flags2 & TF2_ECN_PERMIT)
4813 				tp->t_flags2 |= TF2_ECN_SND_CWR;
4814 		}
4815 		break;
4816 	case CC_RTO:
4817 		tp->t_dupacks = 0;
4818 		tp->t_bytes_acked = 0;
4819 		EXIT_RECOVERY(tp->t_flags);
4820 		tp->snd_ssthresh = max(2, min(tp->snd_wnd, rack->r_ctl.cwnd_to_use) / 2 /
4821 		    ctf_fixed_maxseg(tp)) * ctf_fixed_maxseg(tp);
4822 		orig_cwnd = tp->snd_cwnd;
4823 		tp->snd_cwnd = ctf_fixed_maxseg(tp);
4824 		rack_log_to_prr(rack, 16, orig_cwnd, line);
4825 		if (tp->t_flags2 & TF2_ECN_PERMIT)
4826 			tp->t_flags2 |= TF2_ECN_SND_CWR;
4827 		break;
4828 	case CC_RTO_ERR:
4829 		KMOD_TCPSTAT_INC(tcps_sndrexmitbad);
4830 		/* RTO was unnecessary, so reset everything. */
4831 		tp->snd_cwnd = tp->snd_cwnd_prev;
4832 		tp->snd_ssthresh = tp->snd_ssthresh_prev;
4833 		tp->snd_recover = tp->snd_recover_prev;
4834 		if (tp->t_flags & TF_WASFRECOVERY) {
4835 			ENTER_FASTRECOVERY(tp->t_flags);
4836 			tp->t_flags &= ~TF_WASFRECOVERY;
4837 		}
4838 		if (tp->t_flags & TF_WASCRECOVERY) {
4839 			ENTER_CONGRECOVERY(tp->t_flags);
4840 			tp->t_flags &= ~TF_WASCRECOVERY;
4841 		}
4842 		tp->snd_nxt = tp->snd_max;
4843 		tp->t_badrxtwin = 0;
4844 		break;
4845 	}
4846 	if ((CC_ALGO(tp)->cong_signal != NULL)  &&
4847 	    (type != CC_RTO)){
4848 		tp->ccv->curack = ack;
4849 		CC_ALGO(tp)->cong_signal(tp->ccv, type);
4850 	}
4851 	if ((in_rec_at_entry == 0) && IN_RECOVERY(tp->t_flags)) {
4852 		rack_log_to_prr(rack, 15, cwnd_enter, line);
4853 		rack->r_ctl.dsack_byte_cnt = 0;
4854 		rack->r_ctl.retran_during_recovery = 0;
4855 		rack->r_ctl.rc_cwnd_at_erec = cwnd_enter;
4856 		rack->r_ctl.rc_ssthresh_at_erec = ssthresh_enter;
4857 		rack->r_ent_rec_ns = 1;
4858 	}
4859 }
4860 
4861 static inline void
4862 rack_cc_after_idle(struct tcp_rack *rack, struct tcpcb *tp)
4863 {
4864 	uint32_t i_cwnd;
4865 
4866 	INP_WLOCK_ASSERT(tp->t_inpcb);
4867 
4868 #ifdef NETFLIX_STATS
4869 	KMOD_TCPSTAT_INC(tcps_idle_restarts);
4870 	if (tp->t_state == TCPS_ESTABLISHED)
4871 		KMOD_TCPSTAT_INC(tcps_idle_estrestarts);
4872 #endif
4873 	if (CC_ALGO(tp)->after_idle != NULL)
4874 		CC_ALGO(tp)->after_idle(tp->ccv);
4875 
4876 	if (tp->snd_cwnd == 1)
4877 		i_cwnd = tp->t_maxseg;		/* SYN(-ACK) lost */
4878 	else
4879 		i_cwnd = rc_init_window(rack);
4880 
4881 	/*
4882 	 * Being idle is no different than the initial window. If the cc
4883 	 * clamps it down below the initial window raise it to the initial
4884 	 * window.
4885 	 */
4886 	if (tp->snd_cwnd < i_cwnd) {
4887 		tp->snd_cwnd = i_cwnd;
4888 	}
4889 }
4890 
4891 /*
4892  * Indicate whether this ack should be delayed.  We can delay the ack if
4893  * following conditions are met:
4894  *	- There is no delayed ack timer in progress.
4895  *	- Our last ack wasn't a 0-sized window. We never want to delay
4896  *	  the ack that opens up a 0-sized window.
4897  *	- LRO wasn't used for this segment. We make sure by checking that the
4898  *	  segment size is not larger than the MSS.
4899  *	- Delayed acks are enabled or this is a half-synchronized T/TCP
4900  *	  connection.
4901  */
4902 #define DELAY_ACK(tp, tlen)			 \
4903 	(((tp->t_flags & TF_RXWIN0SENT) == 0) && \
4904 	((tp->t_flags & TF_DELACK) == 0) &&	 \
4905 	(tlen <= tp->t_maxseg) &&		 \
4906 	(tp->t_delayed_ack || (tp->t_flags & TF_NEEDSYN)))
4907 
4908 static struct rack_sendmap *
4909 rack_find_lowest_rsm(struct tcp_rack *rack)
4910 {
4911 	struct rack_sendmap *rsm;
4912 
4913 	/*
4914 	 * Walk the time-order transmitted list looking for an rsm that is
4915 	 * not acked. This will be the one that was sent the longest time
4916 	 * ago that is still outstanding.
4917 	 */
4918 	TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
4919 		if (rsm->r_flags & RACK_ACKED) {
4920 			continue;
4921 		}
4922 		goto finish;
4923 	}
4924 finish:
4925 	return (rsm);
4926 }
4927 
4928 static struct rack_sendmap *
4929 rack_find_high_nonack(struct tcp_rack *rack, struct rack_sendmap *rsm)
4930 {
4931 	struct rack_sendmap *prsm;
4932 
4933 	/*
4934 	 * Walk the sequence order list backward until we hit and arrive at
4935 	 * the highest seq not acked. In theory when this is called it
4936 	 * should be the last segment (which it was not).
4937 	 */
4938 	prsm = rsm;
4939 	RB_FOREACH_REVERSE_FROM(prsm, rack_rb_tree_head, rsm) {
4940 		if (prsm->r_flags & (RACK_ACKED | RACK_HAS_FIN)) {
4941 			continue;
4942 		}
4943 		return (prsm);
4944 	}
4945 	return (NULL);
4946 }
4947 
4948 static uint32_t
4949 rack_calc_thresh_rack(struct tcp_rack *rack, uint32_t srtt, uint32_t cts)
4950 {
4951 	int32_t lro;
4952 	uint32_t thresh;
4953 
4954 	/*
4955 	 * lro is the flag we use to determine if we have seen reordering.
4956 	 * If it gets set we have seen reordering. The reorder logic either
4957 	 * works in one of two ways:
4958 	 *
4959 	 * If reorder-fade is configured, then we track the last time we saw
4960 	 * re-ordering occur. If we reach the point where enough time as
4961 	 * passed we no longer consider reordering has occuring.
4962 	 *
4963 	 * Or if reorder-face is 0, then once we see reordering we consider
4964 	 * the connection to alway be subject to reordering and just set lro
4965 	 * to 1.
4966 	 *
4967 	 * In the end if lro is non-zero we add the extra time for
4968 	 * reordering in.
4969 	 */
4970 	if (srtt == 0)
4971 		srtt = 1;
4972 	if (rack->r_ctl.rc_reorder_ts) {
4973 		if (rack->r_ctl.rc_reorder_fade) {
4974 			if (SEQ_GEQ(cts, rack->r_ctl.rc_reorder_ts)) {
4975 				lro = cts - rack->r_ctl.rc_reorder_ts;
4976 				if (lro == 0) {
4977 					/*
4978 					 * No time as passed since the last
4979 					 * reorder, mark it as reordering.
4980 					 */
4981 					lro = 1;
4982 				}
4983 			} else {
4984 				/* Negative time? */
4985 				lro = 0;
4986 			}
4987 			if (lro > rack->r_ctl.rc_reorder_fade) {
4988 				/* Turn off reordering seen too */
4989 				rack->r_ctl.rc_reorder_ts = 0;
4990 				lro = 0;
4991 			}
4992 		} else {
4993 			/* Reodering does not fade */
4994 			lro = 1;
4995 		}
4996 	} else {
4997 		lro = 0;
4998 	}
4999 	if (rack->rc_rack_tmr_std_based == 0) {
5000 		thresh = srtt + rack->r_ctl.rc_pkt_delay;
5001 	} else {
5002 		/* Standards based pkt-delay is 1/4 srtt */
5003 		thresh = srtt +  (srtt >> 2);
5004 	}
5005 	if (lro && (rack->rc_rack_tmr_std_based == 0)) {
5006 		/* It must be set, if not you get 1/4 rtt */
5007 		if (rack->r_ctl.rc_reorder_shift)
5008 			thresh += (srtt >> rack->r_ctl.rc_reorder_shift);
5009 		else
5010 			thresh += (srtt >> 2);
5011 	}
5012 	if (rack->rc_rack_use_dsack &&
5013 	    lro &&
5014 	    (rack->r_ctl.num_dsack > 0)) {
5015 		/*
5016 		 * We only increase the reordering window if we
5017 		 * have seen reordering <and> we have a DSACK count.
5018 		 */
5019 		thresh += rack->r_ctl.num_dsack * (srtt >> 2);
5020 		rack_log_dsack_event(rack, 4, __LINE__, srtt, thresh);
5021 	}
5022 	/* SRTT * 2 is the ceiling */
5023 	if (thresh > (srtt * 2)) {
5024 		thresh = srtt * 2;
5025 	}
5026 	/* And we don't want it above the RTO max either */
5027 	if (thresh > rack_rto_max) {
5028 		thresh = rack_rto_max;
5029 	}
5030 	rack_log_dsack_event(rack, 6, __LINE__, srtt, thresh);
5031 	return (thresh);
5032 }
5033 
5034 static uint32_t
5035 rack_calc_thresh_tlp(struct tcpcb *tp, struct tcp_rack *rack,
5036 		     struct rack_sendmap *rsm, uint32_t srtt)
5037 {
5038 	struct rack_sendmap *prsm;
5039 	uint32_t thresh, len;
5040 	int segsiz;
5041 
5042 	if (srtt == 0)
5043 		srtt = 1;
5044 	if (rack->r_ctl.rc_tlp_threshold)
5045 		thresh = srtt + (srtt / rack->r_ctl.rc_tlp_threshold);
5046 	else
5047 		thresh = (srtt * 2);
5048 
5049 	/* Get the previous sent packet, if any */
5050 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
5051 	len = rsm->r_end - rsm->r_start;
5052 	if (rack->rack_tlp_threshold_use == TLP_USE_ID) {
5053 		/* Exactly like the ID */
5054 		if (((tp->snd_max - tp->snd_una) - rack->r_ctl.rc_sacked + rack->r_ctl.rc_holes_rxt) <= segsiz) {
5055 			uint32_t alt_thresh;
5056 			/*
5057 			 * Compensate for delayed-ack with the d-ack time.
5058 			 */
5059 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5060 			if (alt_thresh > thresh)
5061 				thresh = alt_thresh;
5062 		}
5063 	} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_ONE) {
5064 		/* 2.1 behavior */
5065 		prsm = TAILQ_PREV(rsm, rack_head, r_tnext);
5066 		if (prsm && (len <= segsiz)) {
5067 			/*
5068 			 * Two packets outstanding, thresh should be (2*srtt) +
5069 			 * possible inter-packet delay (if any).
5070 			 */
5071 			uint32_t inter_gap = 0;
5072 			int idx, nidx;
5073 
5074 			idx = rsm->r_rtr_cnt - 1;
5075 			nidx = prsm->r_rtr_cnt - 1;
5076 			if (rsm->r_tim_lastsent[nidx] >= prsm->r_tim_lastsent[idx]) {
5077 				/* Yes it was sent later (or at the same time) */
5078 				inter_gap = rsm->r_tim_lastsent[idx] - prsm->r_tim_lastsent[nidx];
5079 			}
5080 			thresh += inter_gap;
5081 		} else if (len <= segsiz) {
5082 			/*
5083 			 * Possibly compensate for delayed-ack.
5084 			 */
5085 			uint32_t alt_thresh;
5086 
5087 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5088 			if (alt_thresh > thresh)
5089 				thresh = alt_thresh;
5090 		}
5091 	} else if (rack->rack_tlp_threshold_use == TLP_USE_TWO_TWO) {
5092 		/* 2.2 behavior */
5093 		if (len <= segsiz) {
5094 			uint32_t alt_thresh;
5095 			/*
5096 			 * Compensate for delayed-ack with the d-ack time.
5097 			 */
5098 			alt_thresh = srtt + (srtt / 2) + rack_delayed_ack_time;
5099 			if (alt_thresh > thresh)
5100 				thresh = alt_thresh;
5101 		}
5102 	}
5103 	/* Not above an RTO */
5104 	if (thresh > tp->t_rxtcur) {
5105 		thresh = tp->t_rxtcur;
5106 	}
5107 	/* Not above a RTO max */
5108 	if (thresh > rack_rto_max) {
5109 		thresh = rack_rto_max;
5110 	}
5111 	/* Apply user supplied min TLP */
5112 	if (thresh < rack_tlp_min) {
5113 		thresh = rack_tlp_min;
5114 	}
5115 	return (thresh);
5116 }
5117 
5118 static uint32_t
5119 rack_grab_rtt(struct tcpcb *tp, struct tcp_rack *rack)
5120 {
5121 	/*
5122 	 * We want the rack_rtt which is the
5123 	 * last rtt we measured. However if that
5124 	 * does not exist we fallback to the srtt (which
5125 	 * we probably will never do) and then as a last
5126 	 * resort we use RACK_INITIAL_RTO if no srtt is
5127 	 * yet set.
5128 	 */
5129 	if (rack->rc_rack_rtt)
5130 		return (rack->rc_rack_rtt);
5131 	else if (tp->t_srtt == 0)
5132 		return (RACK_INITIAL_RTO);
5133 	return (tp->t_srtt);
5134 }
5135 
5136 static struct rack_sendmap *
5137 rack_check_recovery_mode(struct tcpcb *tp, uint32_t tsused)
5138 {
5139 	/*
5140 	 * Check to see that we don't need to fall into recovery. We will
5141 	 * need to do so if our oldest transmit is past the time we should
5142 	 * have had an ack.
5143 	 */
5144 	struct tcp_rack *rack;
5145 	struct rack_sendmap *rsm;
5146 	int32_t idx;
5147 	uint32_t srtt, thresh;
5148 
5149 	rack = (struct tcp_rack *)tp->t_fb_ptr;
5150 	if (RB_EMPTY(&rack->r_ctl.rc_mtree)) {
5151 		return (NULL);
5152 	}
5153 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
5154 	if (rsm == NULL)
5155 		return (NULL);
5156 
5157 
5158 	if (rsm->r_flags & RACK_ACKED) {
5159 		rsm = rack_find_lowest_rsm(rack);
5160 		if (rsm == NULL)
5161 			return (NULL);
5162 	}
5163 	idx = rsm->r_rtr_cnt - 1;
5164 	srtt = rack_grab_rtt(tp, rack);
5165 	thresh = rack_calc_thresh_rack(rack, srtt, tsused);
5166 	if (TSTMP_LT(tsused, ((uint32_t)rsm->r_tim_lastsent[idx]))) {
5167 		return (NULL);
5168 	}
5169 	if ((tsused - ((uint32_t)rsm->r_tim_lastsent[idx])) < thresh) {
5170 		return (NULL);
5171 	}
5172 	/* Ok if we reach here we are over-due and this guy can be sent */
5173 	rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
5174 	return (rsm);
5175 }
5176 
5177 static uint32_t
5178 rack_get_persists_timer_val(struct tcpcb *tp, struct tcp_rack *rack)
5179 {
5180 	int32_t t;
5181 	int32_t tt;
5182 	uint32_t ret_val;
5183 
5184 	t = (tp->t_srtt + (tp->t_rttvar << 2));
5185 	RACK_TCPT_RANGESET(tt, t * tcp_backoff[tp->t_rxtshift],
5186  	    rack_persist_min, rack_persist_max, rack->r_ctl.timer_slop);
5187 	rack->r_ctl.rc_hpts_flags |= PACE_TMR_PERSIT;
5188 	ret_val = (uint32_t)tt;
5189 	return (ret_val);
5190 }
5191 
5192 static uint32_t
5193 rack_timer_start(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int sup_rack)
5194 {
5195 	/*
5196 	 * Start the FR timer, we do this based on getting the first one in
5197 	 * the rc_tmap. Note that if its NULL we must stop the timer. in all
5198 	 * events we need to stop the running timer (if its running) before
5199 	 * starting the new one.
5200 	 */
5201 	uint32_t thresh, exp, to, srtt, time_since_sent, tstmp_touse;
5202 	uint32_t srtt_cur;
5203 	int32_t idx;
5204 	int32_t is_tlp_timer = 0;
5205 	struct rack_sendmap *rsm;
5206 
5207 	if (rack->t_timers_stopped) {
5208 		/* All timers have been stopped none are to run */
5209 		return (0);
5210 	}
5211 	if (rack->rc_in_persist) {
5212 		/* We can't start any timer in persists */
5213 		return (rack_get_persists_timer_val(tp, rack));
5214 	}
5215 	rack->rc_on_min_to = 0;
5216 	if ((tp->t_state < TCPS_ESTABLISHED) ||
5217 	    ((tp->t_flags & TF_SACK_PERMIT) == 0)) {
5218 		goto activate_rxt;
5219 	}
5220 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
5221 	if ((rsm == NULL) || sup_rack) {
5222 		/* Nothing on the send map or no rack */
5223 activate_rxt:
5224 		time_since_sent = 0;
5225 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
5226 		if (rsm) {
5227 			/*
5228 			 * Should we discount the RTX timer any?
5229 			 *
5230 			 * We want to discount it the smallest amount.
5231 			 * If a timer (Rack/TLP or RXT) has gone off more
5232 			 * recently thats the discount we want to use (now - timer time).
5233 			 * If the retransmit of the oldest packet was more recent then
5234 			 * we want to use that (now - oldest-packet-last_transmit_time).
5235 			 *
5236 			 */
5237 			idx = rsm->r_rtr_cnt - 1;
5238 			if (TSTMP_GEQ(rack->r_ctl.rc_tlp_rxt_last_time, ((uint32_t)rsm->r_tim_lastsent[idx])))
5239 				tstmp_touse = (uint32_t)rack->r_ctl.rc_tlp_rxt_last_time;
5240 			else
5241 				tstmp_touse = (uint32_t)rsm->r_tim_lastsent[idx];
5242 			if (TSTMP_GT(cts, tstmp_touse))
5243 			    time_since_sent = cts - tstmp_touse;
5244 		}
5245 		if (SEQ_LT(tp->snd_una, tp->snd_max) || sbavail(&(tp->t_inpcb->inp_socket->so_snd))) {
5246 			rack->r_ctl.rc_hpts_flags |= PACE_TMR_RXT;
5247 			to = tp->t_rxtcur;
5248 			if (to > time_since_sent)
5249 				to -= time_since_sent;
5250 			else
5251 				to = rack->r_ctl.rc_min_to;
5252 			if (to == 0)
5253 				to = 1;
5254 			/* Special case for KEEPINIT */
5255 			if ((TCPS_HAVEESTABLISHED(tp->t_state) == 0) &&
5256 			    (TP_KEEPINIT(tp) != 0) &&
5257 			    rsm) {
5258 				/*
5259 				 * We have to put a ceiling on the rxt timer
5260 				 * of the keep-init timeout.
5261 				 */
5262 				uint32_t max_time, red;
5263 
5264 				max_time = TICKS_2_USEC(TP_KEEPINIT(tp));
5265 				if (TSTMP_GT(cts, (uint32_t)rsm->r_tim_lastsent[0])) {
5266 					red = (cts - (uint32_t)rsm->r_tim_lastsent[0]);
5267 					if (red < max_time)
5268 						max_time -= red;
5269 					else
5270 						max_time = 1;
5271 				}
5272 				/* Reduce timeout to the keep value if needed */
5273 				if (max_time < to)
5274 					to = max_time;
5275 			}
5276 			return (to);
5277 		}
5278 		return (0);
5279 	}
5280 	if (rsm->r_flags & RACK_ACKED) {
5281 		rsm = rack_find_lowest_rsm(rack);
5282 		if (rsm == NULL) {
5283 			/* No lowest? */
5284 			goto activate_rxt;
5285 		}
5286 	}
5287 	if (rack->sack_attack_disable) {
5288 		/*
5289 		 * We don't want to do
5290 		 * any TLP's if you are an attacker.
5291 		 * Though if you are doing what
5292 		 * is expected you may still have
5293 		 * SACK-PASSED marks.
5294 		 */
5295 		goto activate_rxt;
5296 	}
5297 	/* Convert from ms to usecs */
5298 	if ((rsm->r_flags & RACK_SACK_PASSED) || (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
5299 		if ((tp->t_flags & TF_SENTFIN) &&
5300 		    ((tp->snd_max - tp->snd_una) == 1) &&
5301 		    (rsm->r_flags & RACK_HAS_FIN)) {
5302 			/*
5303 			 * We don't start a rack timer if all we have is a
5304 			 * FIN outstanding.
5305 			 */
5306 			goto activate_rxt;
5307 		}
5308 		if ((rack->use_rack_rr == 0) &&
5309 		    (IN_FASTRECOVERY(tp->t_flags)) &&
5310 		    (rack->rack_no_prr == 0) &&
5311 		     (rack->r_ctl.rc_prr_sndcnt  < ctf_fixed_maxseg(tp))) {
5312 			/*
5313 			 * We are not cheating, in recovery  and
5314 			 * not enough ack's to yet get our next
5315 			 * retransmission out.
5316 			 *
5317 			 * Note that classified attackers do not
5318 			 * get to use the rack-cheat.
5319 			 */
5320 			goto activate_tlp;
5321 		}
5322 		srtt = rack_grab_rtt(tp, rack);
5323 		thresh = rack_calc_thresh_rack(rack, srtt, cts);
5324 		idx = rsm->r_rtr_cnt - 1;
5325 		exp = ((uint32_t)rsm->r_tim_lastsent[idx]) + thresh;
5326 		if (SEQ_GEQ(exp, cts)) {
5327 			to = exp - cts;
5328 			if (to < rack->r_ctl.rc_min_to) {
5329 				to = rack->r_ctl.rc_min_to;
5330 				if (rack->r_rr_config == 3)
5331 					rack->rc_on_min_to = 1;
5332 			}
5333 		} else {
5334 			to = rack->r_ctl.rc_min_to;
5335 			if (rack->r_rr_config == 3)
5336 				rack->rc_on_min_to = 1;
5337 		}
5338 	} else {
5339 		/* Ok we need to do a TLP not RACK */
5340 activate_tlp:
5341 		if ((rack->rc_tlp_in_progress != 0) &&
5342 		    (rack->r_ctl.rc_tlp_cnt_out >= rack_tlp_limit)) {
5343 			/*
5344 			 * The previous send was a TLP and we have sent
5345 			 * N TLP's without sending new data.
5346 			 */
5347 			goto activate_rxt;
5348 		}
5349 		rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
5350 		if (rsm == NULL) {
5351 			/* We found no rsm to TLP with. */
5352 			goto activate_rxt;
5353 		}
5354 		if (rsm->r_flags & RACK_HAS_FIN) {
5355 			/* If its a FIN we dont do TLP */
5356 			rsm = NULL;
5357 			goto activate_rxt;
5358 		}
5359 		idx = rsm->r_rtr_cnt - 1;
5360 		time_since_sent = 0;
5361 		if (TSTMP_GEQ(((uint32_t)rsm->r_tim_lastsent[idx]), rack->r_ctl.rc_tlp_rxt_last_time))
5362 			tstmp_touse = (uint32_t)rsm->r_tim_lastsent[idx];
5363 		else
5364 			tstmp_touse = (uint32_t)rack->r_ctl.rc_tlp_rxt_last_time;
5365 		if (TSTMP_GT(cts, tstmp_touse))
5366 		    time_since_sent = cts - tstmp_touse;
5367 		is_tlp_timer = 1;
5368 		if (tp->t_srtt) {
5369 			if ((rack->rc_srtt_measure_made == 0) &&
5370 			    (tp->t_srtt == 1)) {
5371 				/*
5372 				 * If another stack as run and set srtt to 1,
5373 				 * then the srtt was 0, so lets use the initial.
5374 				 */
5375 				srtt = RACK_INITIAL_RTO;
5376 			} else {
5377 				srtt_cur = tp->t_srtt;
5378 				srtt = srtt_cur;
5379 			}
5380 		} else
5381 			srtt = RACK_INITIAL_RTO;
5382 		/*
5383 		 * If the SRTT is not keeping up and the
5384 		 * rack RTT has spiked we want to use
5385 		 * the last RTT not the smoothed one.
5386 		 */
5387 		if (rack_tlp_use_greater &&
5388 		    tp->t_srtt &&
5389 		    (srtt < rack_grab_rtt(tp, rack))) {
5390 			srtt = rack_grab_rtt(tp, rack);
5391 		}
5392 		thresh = rack_calc_thresh_tlp(tp, rack, rsm, srtt);
5393 		if (thresh > time_since_sent) {
5394 			to = thresh - time_since_sent;
5395 		} else {
5396 			to = rack->r_ctl.rc_min_to;
5397 			rack_log_alt_to_to_cancel(rack,
5398 						  thresh,		/* flex1 */
5399 						  time_since_sent,	/* flex2 */
5400 						  tstmp_touse,		/* flex3 */
5401 						  rack->r_ctl.rc_tlp_rxt_last_time, /* flex4 */
5402 						  (uint32_t)rsm->r_tim_lastsent[idx],
5403 						  srtt,
5404 						  idx, 99);
5405 		}
5406 		if (to < rack_tlp_min) {
5407 			to = rack_tlp_min;
5408 		}
5409 		if (to > TICKS_2_USEC(TCPTV_REXMTMAX)) {
5410 			/*
5411 			 * If the TLP time works out to larger than the max
5412 			 * RTO lets not do TLP.. just RTO.
5413 			 */
5414 			goto activate_rxt;
5415 		}
5416 	}
5417 	if (is_tlp_timer == 0) {
5418 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_RACK;
5419 	} else {
5420 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_TLP;
5421 	}
5422 	if (to == 0)
5423 		to = 1;
5424 	return (to);
5425 }
5426 
5427 static void
5428 rack_enter_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
5429 {
5430 	if (rack->rc_in_persist == 0) {
5431 		if (tp->t_flags & TF_GPUTINPROG) {
5432 			/*
5433 			 * Stop the goodput now, the calling of the
5434 			 * measurement function clears the flag.
5435 			 */
5436 			rack_do_goodput_measurement(tp, rack, tp->snd_una, __LINE__,
5437 						    RACK_QUALITY_PERSIST);
5438 		}
5439 #ifdef NETFLIX_SHARED_CWND
5440 		if (rack->r_ctl.rc_scw) {
5441 			tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
5442 			rack->rack_scwnd_is_idle = 1;
5443 		}
5444 #endif
5445 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
5446 		if (rack->r_ctl.rc_went_idle_time == 0)
5447 			rack->r_ctl.rc_went_idle_time = 1;
5448 		rack_timer_cancel(tp, rack, cts, __LINE__);
5449 		rack->r_ctl.persist_lost_ends = 0;
5450 		rack->probe_not_answered = 0;
5451 		rack->forced_ack = 0;
5452 		tp->t_rxtshift = 0;
5453 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
5454 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
5455 		rack->rc_in_persist = 1;
5456 	}
5457 }
5458 
5459 static void
5460 rack_exit_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
5461 {
5462 	if (tcp_in_hpts(rack->rc_inp)) {
5463 		tcp_hpts_remove(rack->rc_inp);
5464 		rack->r_ctl.rc_hpts_flags = 0;
5465 	}
5466 #ifdef NETFLIX_SHARED_CWND
5467 	if (rack->r_ctl.rc_scw) {
5468 		tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
5469 		rack->rack_scwnd_is_idle = 0;
5470 	}
5471 #endif
5472 	if (rack->rc_gp_dyn_mul &&
5473 	    (rack->use_fixed_rate == 0) &&
5474 	    (rack->rc_always_pace)) {
5475 		/*
5476 		 * Do we count this as if a probe-rtt just
5477 		 * finished?
5478 		 */
5479 		uint32_t time_idle, idle_min;
5480 
5481 		time_idle = tcp_get_usecs(NULL) - rack->r_ctl.rc_went_idle_time;
5482 		idle_min = rack_min_probertt_hold;
5483 		if (rack_probertt_gpsrtt_cnt_div) {
5484 			uint64_t extra;
5485 			extra = (uint64_t)rack->r_ctl.rc_gp_srtt *
5486 				(uint64_t)rack_probertt_gpsrtt_cnt_mul;
5487 			extra /= (uint64_t)rack_probertt_gpsrtt_cnt_div;
5488 			idle_min += (uint32_t)extra;
5489 		}
5490 		if (time_idle >= idle_min) {
5491 			/* Yes, we count it as a probe-rtt. */
5492 			uint32_t us_cts;
5493 
5494 			us_cts = tcp_get_usecs(NULL);
5495 			if (rack->in_probe_rtt == 0) {
5496 				rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
5497 				rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
5498 				rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
5499 				rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
5500 			} else {
5501 				rack_exit_probertt(rack, us_cts);
5502 			}
5503 		}
5504 	}
5505 	rack->rc_in_persist = 0;
5506 	rack->r_ctl.rc_went_idle_time = 0;
5507 	tp->t_rxtshift = 0;
5508 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
5509 	   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
5510 	rack->r_ctl.rc_agg_delayed = 0;
5511 	rack->r_early = 0;
5512 	rack->r_late = 0;
5513 	rack->r_ctl.rc_agg_early = 0;
5514 }
5515 
5516 static void
5517 rack_log_hpts_diag(struct tcp_rack *rack, uint32_t cts,
5518 		   struct hpts_diag *diag, struct timeval *tv)
5519 {
5520 	if (rack_verbose_logging && rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
5521 		union tcp_log_stackspecific log;
5522 
5523 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5524 		log.u_bbr.flex1 = diag->p_nxt_slot;
5525 		log.u_bbr.flex2 = diag->p_cur_slot;
5526 		log.u_bbr.flex3 = diag->slot_req;
5527 		log.u_bbr.flex4 = diag->inp_hptsslot;
5528 		log.u_bbr.flex5 = diag->slot_remaining;
5529 		log.u_bbr.flex6 = diag->need_new_to;
5530 		log.u_bbr.flex7 = diag->p_hpts_active;
5531 		log.u_bbr.flex8 = diag->p_on_min_sleep;
5532 		/* Hijack other fields as needed */
5533 		log.u_bbr.epoch = diag->have_slept;
5534 		log.u_bbr.lt_epoch = diag->yet_to_sleep;
5535 		log.u_bbr.pkts_out = diag->co_ret;
5536 		log.u_bbr.applimited = diag->hpts_sleep_time;
5537 		log.u_bbr.delivered = diag->p_prev_slot;
5538 		log.u_bbr.inflight = diag->p_runningslot;
5539 		log.u_bbr.bw_inuse = diag->wheel_slot;
5540 		log.u_bbr.rttProp = diag->wheel_cts;
5541 		log.u_bbr.timeStamp = cts;
5542 		log.u_bbr.delRate = diag->maxslots;
5543 		log.u_bbr.cur_del_rate = diag->p_curtick;
5544 		log.u_bbr.cur_del_rate <<= 32;
5545 		log.u_bbr.cur_del_rate |= diag->p_lasttick;
5546 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
5547 		    &rack->rc_inp->inp_socket->so_rcv,
5548 		    &rack->rc_inp->inp_socket->so_snd,
5549 		    BBR_LOG_HPTSDIAG, 0,
5550 		    0, &log, false, tv);
5551 	}
5552 
5553 }
5554 
5555 static void
5556 rack_log_wakeup(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb, uint32_t len, int type)
5557 {
5558 	if (rack_verbose_logging && rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
5559 		union tcp_log_stackspecific log;
5560 		struct timeval tv;
5561 
5562 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
5563 		log.u_bbr.flex1 = sb->sb_flags;
5564 		log.u_bbr.flex2 = len;
5565 		log.u_bbr.flex3 = sb->sb_state;
5566 		log.u_bbr.flex8 = type;
5567 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
5568 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
5569 		    &rack->rc_inp->inp_socket->so_rcv,
5570 		    &rack->rc_inp->inp_socket->so_snd,
5571 		    TCP_LOG_SB_WAKE, 0,
5572 		    len, &log, false, &tv);
5573 	}
5574 }
5575 
5576 static void
5577 rack_start_hpts_timer(struct tcp_rack *rack, struct tcpcb *tp, uint32_t cts,
5578       int32_t slot, uint32_t tot_len_this_send, int sup_rack)
5579 {
5580 	struct hpts_diag diag;
5581 	struct inpcb *inp;
5582 	struct timeval tv;
5583 	uint32_t delayed_ack = 0;
5584 	uint32_t hpts_timeout;
5585 	uint32_t entry_slot = slot;
5586 	uint8_t stopped;
5587 	uint32_t left = 0;
5588 	uint32_t us_cts;
5589 
5590 	inp = tp->t_inpcb;
5591 	if ((tp->t_state == TCPS_CLOSED) ||
5592 	    (tp->t_state == TCPS_LISTEN)) {
5593 		return;
5594 	}
5595 	if (tcp_in_hpts(inp)) {
5596 		/* Already on the pacer */
5597 		return;
5598 	}
5599 	stopped = rack->rc_tmr_stopped;
5600 	if (stopped && TSTMP_GT(rack->r_ctl.rc_timer_exp, cts)) {
5601 		left = rack->r_ctl.rc_timer_exp - cts;
5602 	}
5603 	rack->r_ctl.rc_timer_exp = 0;
5604 	rack->r_ctl.rc_hpts_flags = 0;
5605 	us_cts = tcp_get_usecs(&tv);
5606 	/* Now early/late accounting */
5607 	rack_log_pacing_delay_calc(rack, entry_slot, slot, 0, 0, 0, 26, __LINE__, NULL, 0);
5608 	if (rack->r_early && (rack->rc_ack_can_sendout_data == 0)) {
5609 		/*
5610 		 * We have a early carry over set,
5611 		 * we can always add more time so we
5612 		 * can always make this compensation.
5613 		 *
5614 		 * Note if ack's are allowed to wake us do not
5615 		 * penalize the next timer for being awoke
5616 		 * by an ack aka the rc_agg_early (non-paced mode).
5617 		 */
5618 		slot += rack->r_ctl.rc_agg_early;
5619 		rack->r_early = 0;
5620 		rack->r_ctl.rc_agg_early = 0;
5621 	}
5622 	if (rack->r_late) {
5623 		/*
5624 		 * This is harder, we can
5625 		 * compensate some but it
5626 		 * really depends on what
5627 		 * the current pacing time is.
5628 		 */
5629 		if (rack->r_ctl.rc_agg_delayed >= slot) {
5630 			/*
5631 			 * We can't compensate for it all.
5632 			 * And we have to have some time
5633 			 * on the clock. We always have a min
5634 			 * 10 slots (10 x 10 i.e. 100 usecs).
5635 			 */
5636 			if (slot <= HPTS_TICKS_PER_SLOT) {
5637 				/* We gain delay */
5638 				rack->r_ctl.rc_agg_delayed += (HPTS_TICKS_PER_SLOT - slot);
5639 				slot = HPTS_TICKS_PER_SLOT;
5640 			} else {
5641 				/* We take off some */
5642 				rack->r_ctl.rc_agg_delayed -= (slot - HPTS_TICKS_PER_SLOT);
5643 				slot = HPTS_TICKS_PER_SLOT;
5644 			}
5645 		} else {
5646 			slot -= rack->r_ctl.rc_agg_delayed;
5647 			rack->r_ctl.rc_agg_delayed = 0;
5648 			/* Make sure we have 100 useconds at minimum */
5649 			if (slot < HPTS_TICKS_PER_SLOT) {
5650 				rack->r_ctl.rc_agg_delayed = HPTS_TICKS_PER_SLOT - slot;
5651 				slot = HPTS_TICKS_PER_SLOT;
5652 			}
5653 			if (rack->r_ctl.rc_agg_delayed == 0)
5654 				rack->r_late = 0;
5655 		}
5656 	}
5657 	if (slot) {
5658 		/* We are pacing too */
5659 		rack->r_ctl.rc_hpts_flags |= PACE_PKT_OUTPUT;
5660 	}
5661 	hpts_timeout = rack_timer_start(tp, rack, cts, sup_rack);
5662 #ifdef NETFLIX_EXP_DETECTION
5663 	if (rack->sack_attack_disable &&
5664 	    (slot < tcp_sad_pacing_interval)) {
5665 		/*
5666 		 * We have a potential attacker on
5667 		 * the line. We have possibly some
5668 		 * (or now) pacing time set. We want to
5669 		 * slow down the processing of sacks by some
5670 		 * amount (if it is an attacker). Set the default
5671 		 * slot for attackers in place (unless the orginal
5672 		 * interval is longer). Its stored in
5673 		 * micro-seconds, so lets convert to msecs.
5674 		 */
5675 		slot = tcp_sad_pacing_interval;
5676 	}
5677 #endif
5678 	if (tp->t_flags & TF_DELACK) {
5679 		delayed_ack = TICKS_2_USEC(tcp_delacktime);
5680 		rack->r_ctl.rc_hpts_flags |= PACE_TMR_DELACK;
5681 	}
5682 	if (delayed_ack && ((hpts_timeout == 0) ||
5683 			    (delayed_ack < hpts_timeout)))
5684 		hpts_timeout = delayed_ack;
5685 	else
5686 		rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
5687 	/*
5688 	 * If no timers are going to run and we will fall off the hptsi
5689 	 * wheel, we resort to a keep-alive timer if its configured.
5690 	 */
5691 	if ((hpts_timeout == 0) &&
5692 	    (slot == 0)) {
5693 		if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
5694 		    (tp->t_state <= TCPS_CLOSING)) {
5695 			/*
5696 			 * Ok we have no timer (persists, rack, tlp, rxt  or
5697 			 * del-ack), we don't have segments being paced. So
5698 			 * all that is left is the keepalive timer.
5699 			 */
5700 			if (TCPS_HAVEESTABLISHED(tp->t_state)) {
5701 				/* Get the established keep-alive time */
5702 				hpts_timeout = TICKS_2_USEC(TP_KEEPIDLE(tp));
5703 			} else {
5704 				/*
5705 				 * Get the initial setup keep-alive time,
5706 				 * note that this is probably not going to
5707 				 * happen, since rack will be running a rxt timer
5708 				 * if a SYN of some sort is outstanding. It is
5709 				 * actually handled in rack_timeout_rxt().
5710 				 */
5711 				hpts_timeout = TICKS_2_USEC(TP_KEEPINIT(tp));
5712 			}
5713 			rack->r_ctl.rc_hpts_flags |= PACE_TMR_KEEP;
5714 			if (rack->in_probe_rtt) {
5715 				/*
5716 				 * We want to instead not wake up a long time from
5717 				 * now but to wake up about the time we would
5718 				 * exit probe-rtt and initiate a keep-alive ack.
5719 				 * This will get us out of probe-rtt and update
5720 				 * our min-rtt.
5721 				 */
5722 				hpts_timeout = rack_min_probertt_hold;
5723 			}
5724 		}
5725 	}
5726 	if (left && (stopped & (PACE_TMR_KEEP | PACE_TMR_DELACK)) ==
5727 	    (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK)) {
5728 		/*
5729 		 * RACK, TLP, persists and RXT timers all are restartable
5730 		 * based on actions input .. i.e we received a packet (ack
5731 		 * or sack) and that changes things (rw, or snd_una etc).
5732 		 * Thus we can restart them with a new value. For
5733 		 * keep-alive, delayed_ack we keep track of what was left
5734 		 * and restart the timer with a smaller value.
5735 		 */
5736 		if (left < hpts_timeout)
5737 			hpts_timeout = left;
5738 	}
5739 	if (hpts_timeout) {
5740 		/*
5741 		 * Hack alert for now we can't time-out over 2,147,483
5742 		 * seconds (a bit more than 596 hours), which is probably ok
5743 		 * :).
5744 		 */
5745 		if (hpts_timeout > 0x7ffffffe)
5746 			hpts_timeout = 0x7ffffffe;
5747 		rack->r_ctl.rc_timer_exp = cts + hpts_timeout;
5748 	}
5749 	rack_log_pacing_delay_calc(rack, entry_slot, slot, hpts_timeout, 0, 0, 27, __LINE__, NULL, 0);
5750 	if ((rack->gp_ready == 0) &&
5751 	    (rack->use_fixed_rate == 0) &&
5752 	    (hpts_timeout < slot) &&
5753 	    (rack->r_ctl.rc_hpts_flags & (PACE_TMR_TLP|PACE_TMR_RXT))) {
5754 		/*
5755 		 * We have no good estimate yet for the
5756 		 * old clunky burst mitigation or the
5757 		 * real pacing. And the tlp or rxt is smaller
5758 		 * than the pacing calculation. Lets not
5759 		 * pace that long since we know the calculation
5760 		 * so far is not accurate.
5761 		 */
5762 		slot = hpts_timeout;
5763 	}
5764 	/**
5765 	 * Turn off all the flags for queuing by default. The
5766 	 * flags have important meanings to what happens when
5767 	 * LRO interacts with the transport. Most likely (by default now)
5768 	 * mbuf_queueing and ack compression are on. So the transport
5769 	 * has a couple of flags that control what happens (if those
5770 	 * are not on then these flags won't have any effect since it
5771 	 * won't go through the queuing LRO path).
5772 	 *
5773 	 * INP_MBUF_QUEUE_READY - This flags says that I am busy
5774 	 *                        pacing output, so don't disturb. But
5775 	 *                        it also means LRO can wake me if there
5776 	 *                        is a SACK arrival.
5777 	 *
5778 	 * INP_DONT_SACK_QUEUE - This flag is used in conjunction
5779 	 *                       with the above flag (QUEUE_READY) and
5780 	 *                       when present it says don't even wake me
5781 	 *                       if a SACK arrives.
5782 	 *
5783 	 * The idea behind these flags is that if we are pacing we
5784 	 * set the MBUF_QUEUE_READY and only get woken up if
5785 	 * a SACK arrives (which could change things) or if
5786 	 * our pacing timer expires. If, however, we have a rack
5787 	 * timer running, then we don't even want a sack to wake
5788 	 * us since the rack timer has to expire before we can send.
5789 	 *
5790 	 * Other cases should usually have none of the flags set
5791 	 * so LRO can call into us.
5792 	 */
5793 	inp->inp_flags2 &= ~(INP_DONT_SACK_QUEUE|INP_MBUF_QUEUE_READY);
5794 	if (slot) {
5795 		rack->r_ctl.rc_last_output_to = us_cts + slot;
5796 		/*
5797 		 * A pacing timer (slot) is being set, in
5798 		 * such a case we cannot send (we are blocked by
5799 		 * the timer). So lets tell LRO that it should not
5800 		 * wake us unless there is a SACK. Note this only
5801 		 * will be effective if mbuf queueing is on or
5802 		 * compressed acks are being processed.
5803 		 */
5804 		inp->inp_flags2 |= INP_MBUF_QUEUE_READY;
5805 		/*
5806 		 * But wait if we have a Rack timer running
5807 		 * even a SACK should not disturb us (with
5808 		 * the exception of r_rr_config 3).
5809 		 */
5810 		if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK) &&
5811 		    (rack->r_rr_config != 3))
5812 			inp->inp_flags2 |= INP_DONT_SACK_QUEUE;
5813 		if (rack->rc_ack_can_sendout_data) {
5814 			/*
5815 			 * Ahh but wait, this is that special case
5816 			 * where the pacing timer can be disturbed
5817 			 * backout the changes (used for non-paced
5818 			 * burst limiting).
5819 			 */
5820 			inp->inp_flags2 &= ~(INP_DONT_SACK_QUEUE|INP_MBUF_QUEUE_READY);
5821 		}
5822 		if ((rack->use_rack_rr) &&
5823 		    (rack->r_rr_config < 2) &&
5824 		    ((hpts_timeout) && (hpts_timeout < slot))) {
5825 			/*
5826 			 * Arrange for the hpts to kick back in after the
5827 			 * t-o if the t-o does not cause a send.
5828 			 */
5829 			(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_USEC_TO_SLOTS(hpts_timeout),
5830 						   __LINE__, &diag);
5831 			rack_log_hpts_diag(rack, us_cts, &diag, &tv);
5832 			rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
5833 		} else {
5834 			(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_USEC_TO_SLOTS(slot),
5835 						   __LINE__, &diag);
5836 			rack_log_hpts_diag(rack, us_cts, &diag, &tv);
5837 			rack_log_to_start(rack, cts, hpts_timeout, slot, 1);
5838 		}
5839 	} else if (hpts_timeout) {
5840 		/*
5841 		 * With respect to inp_flags2 here, lets let any new acks wake
5842 		 * us up here. Since we are not pacing (no pacing timer), output
5843 		 * can happen so we should let it. If its a Rack timer, then any inbound
5844 		 * packet probably won't change the sending (we will be blocked)
5845 		 * but it may change the prr stats so letting it in (the set defaults
5846 		 * at the start of this block) are good enough.
5847 		 */
5848 		(void)tcp_hpts_insert_diag(tp->t_inpcb, HPTS_USEC_TO_SLOTS(hpts_timeout),
5849 					   __LINE__, &diag);
5850 		rack_log_hpts_diag(rack, us_cts, &diag, &tv);
5851 		rack_log_to_start(rack, cts, hpts_timeout, slot, 0);
5852 	} else {
5853 		/* No timer starting */
5854 #ifdef INVARIANTS
5855 		if (SEQ_GT(tp->snd_max, tp->snd_una)) {
5856 			panic("tp:%p rack:%p tlts:%d cts:%u slot:%u pto:%u -- no timer started?",
5857 			    tp, rack, tot_len_this_send, cts, slot, hpts_timeout);
5858 		}
5859 #endif
5860 	}
5861 	rack->rc_tmr_stopped = 0;
5862 	if (slot)
5863 		rack_log_type_bbrsnd(rack, tot_len_this_send, slot, us_cts, &tv);
5864 }
5865 
5866 /*
5867  * RACK Timer, here we simply do logging and house keeping.
5868  * the normal rack_output() function will call the
5869  * appropriate thing to check if we need to do a RACK retransmit.
5870  * We return 1, saying don't proceed with rack_output only
5871  * when all timers have been stopped (destroyed PCB?).
5872  */
5873 static int
5874 rack_timeout_rack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
5875 {
5876 	/*
5877 	 * This timer simply provides an internal trigger to send out data.
5878 	 * The check_recovery_mode call will see if there are needed
5879 	 * retransmissions, if so we will enter fast-recovery. The output
5880 	 * call may or may not do the same thing depending on sysctl
5881 	 * settings.
5882 	 */
5883 	struct rack_sendmap *rsm;
5884 
5885 	if (tp->t_timers->tt_flags & TT_STOPPED) {
5886 		return (1);
5887 	}
5888 	counter_u64_add(rack_to_tot, 1);
5889 	if (rack->r_state && (rack->r_state != tp->t_state))
5890 		rack_set_state(tp, rack);
5891 	rack->rc_on_min_to = 0;
5892 	rsm = rack_check_recovery_mode(tp, cts);
5893 	rack_log_to_event(rack, RACK_TO_FRM_RACK, rsm);
5894 	if (rsm) {
5895 		rack->r_ctl.rc_resend = rsm;
5896 		rack->r_timer_override = 1;
5897 		if (rack->use_rack_rr) {
5898 			/*
5899 			 * Don't accumulate extra pacing delay
5900 			 * we are allowing the rack timer to
5901 			 * over-ride pacing i.e. rrr takes precedence
5902 			 * if the pacing interval is longer than the rrr
5903 			 * time (in other words we get the min pacing
5904 			 * time versus rrr pacing time).
5905 			 */
5906 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
5907 		}
5908 	}
5909 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RACK;
5910 	if (rsm == NULL) {
5911 		/* restart a timer and return 1 */
5912 		rack_start_hpts_timer(rack, tp, cts,
5913 				      0, 0, 0);
5914 		return (1);
5915 	}
5916 	return (0);
5917 }
5918 
5919 static void
5920 rack_adjust_orig_mlen(struct rack_sendmap *rsm)
5921 {
5922 	if (rsm->m->m_len > rsm->orig_m_len) {
5923 		/*
5924 		 * Mbuf grew, caused by sbcompress, our offset does
5925 		 * not change.
5926 		 */
5927 		rsm->orig_m_len = rsm->m->m_len;
5928 	} else if (rsm->m->m_len < rsm->orig_m_len) {
5929 		/*
5930 		 * Mbuf shrank, trimmed off the top by an ack, our
5931 		 * offset changes.
5932 		 */
5933 		rsm->soff -= (rsm->orig_m_len - rsm->m->m_len);
5934 		rsm->orig_m_len = rsm->m->m_len;
5935 	}
5936 }
5937 
5938 static void
5939 rack_setup_offset_for_rsm(struct rack_sendmap *src_rsm, struct rack_sendmap *rsm)
5940 {
5941 	struct mbuf *m;
5942 	uint32_t soff;
5943 
5944 	if (src_rsm->m && (src_rsm->orig_m_len != src_rsm->m->m_len)) {
5945 		/* Fix up the orig_m_len and possibly the mbuf offset */
5946 		rack_adjust_orig_mlen(src_rsm);
5947 	}
5948 	m = src_rsm->m;
5949 	soff = src_rsm->soff + (src_rsm->r_end - src_rsm->r_start);
5950 	while (soff >= m->m_len) {
5951 		/* Move out past this mbuf */
5952 		soff -= m->m_len;
5953 		m = m->m_next;
5954 		KASSERT((m != NULL),
5955 			("rsm:%p nrsm:%p hit at soff:%u null m",
5956 			 src_rsm, rsm, soff));
5957 	}
5958 	rsm->m = m;
5959 	rsm->soff = soff;
5960 	rsm->orig_m_len = m->m_len;
5961 }
5962 
5963 static __inline void
5964 rack_clone_rsm(struct tcp_rack *rack, struct rack_sendmap *nrsm,
5965 	       struct rack_sendmap *rsm, uint32_t start)
5966 {
5967 	int idx;
5968 
5969 	nrsm->r_start = start;
5970 	nrsm->r_end = rsm->r_end;
5971 	nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
5972 	nrsm->r_flags = rsm->r_flags;
5973 	nrsm->r_dupack = rsm->r_dupack;
5974 	nrsm->r_no_rtt_allowed = rsm->r_no_rtt_allowed;
5975 	nrsm->r_rtr_bytes = 0;
5976 	nrsm->r_fas = rsm->r_fas;
5977 	rsm->r_end = nrsm->r_start;
5978 	nrsm->r_just_ret = rsm->r_just_ret;
5979 	for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
5980 		nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
5981 	}
5982 	/* Now if we have SYN flag we keep it on the left edge */
5983 	if (nrsm->r_flags & RACK_HAS_SYN)
5984 		nrsm->r_flags &= ~RACK_HAS_SYN;
5985 	/* Now if we have a FIN flag we keep it on the right edge */
5986 	if (rsm->r_flags & RACK_HAS_FIN)
5987 		rsm->r_flags &= ~RACK_HAS_FIN;
5988 	/* Push bit must go to the right edge as well */
5989 	if (rsm->r_flags & RACK_HAD_PUSH)
5990 		rsm->r_flags &= ~RACK_HAD_PUSH;
5991 	/* Clone over the state of the hw_tls flag */
5992 	nrsm->r_hw_tls = rsm->r_hw_tls;
5993 	/*
5994 	 * Now we need to find nrsm's new location in the mbuf chain
5995 	 * we basically calculate a new offset, which is soff +
5996 	 * how much is left in original rsm. Then we walk out the mbuf
5997 	 * chain to find the righ position, it may be the same mbuf
5998 	 * or maybe not.
5999 	 */
6000 	KASSERT(((rsm->m != NULL) ||
6001 		 (rsm->r_flags & (RACK_HAS_SYN|RACK_HAS_FIN))),
6002 		("rsm:%p nrsm:%p rack:%p -- rsm->m is NULL?", rsm, nrsm, rack));
6003 	if (rsm->m)
6004 		rack_setup_offset_for_rsm(rsm, nrsm);
6005 }
6006 
6007 static struct rack_sendmap *
6008 rack_merge_rsm(struct tcp_rack *rack,
6009 	       struct rack_sendmap *l_rsm,
6010 	       struct rack_sendmap *r_rsm)
6011 {
6012 	/*
6013 	 * We are merging two ack'd RSM's,
6014 	 * the l_rsm is on the left (lower seq
6015 	 * values) and the r_rsm is on the right
6016 	 * (higher seq value). The simplest way
6017 	 * to merge these is to move the right
6018 	 * one into the left. I don't think there
6019 	 * is any reason we need to try to find
6020 	 * the oldest (or last oldest retransmitted).
6021 	 */
6022 #ifdef INVARIANTS
6023 	struct rack_sendmap *rm;
6024 #endif
6025 	rack_log_map_chg(rack->rc_tp, rack, NULL,
6026 			 l_rsm, r_rsm, MAP_MERGE, r_rsm->r_end, __LINE__);
6027 	l_rsm->r_end = r_rsm->r_end;
6028 	if (l_rsm->r_dupack < r_rsm->r_dupack)
6029 		l_rsm->r_dupack = r_rsm->r_dupack;
6030 	if (r_rsm->r_rtr_bytes)
6031 		l_rsm->r_rtr_bytes += r_rsm->r_rtr_bytes;
6032 	if (r_rsm->r_in_tmap) {
6033 		/* This really should not happen */
6034 		TAILQ_REMOVE(&rack->r_ctl.rc_tmap, r_rsm, r_tnext);
6035 		r_rsm->r_in_tmap = 0;
6036 	}
6037 
6038 	/* Now the flags */
6039 	if (r_rsm->r_flags & RACK_HAS_FIN)
6040 		l_rsm->r_flags |= RACK_HAS_FIN;
6041 	if (r_rsm->r_flags & RACK_TLP)
6042 		l_rsm->r_flags |= RACK_TLP;
6043 	if (r_rsm->r_flags & RACK_RWND_COLLAPSED)
6044 		l_rsm->r_flags |= RACK_RWND_COLLAPSED;
6045 	if ((r_rsm->r_flags & RACK_APP_LIMITED)  &&
6046 	    ((l_rsm->r_flags & RACK_APP_LIMITED) == 0)) {
6047 		/*
6048 		 * If both are app-limited then let the
6049 		 * free lower the count. If right is app
6050 		 * limited and left is not, transfer.
6051 		 */
6052 		l_rsm->r_flags |= RACK_APP_LIMITED;
6053 		r_rsm->r_flags &= ~RACK_APP_LIMITED;
6054 		if (r_rsm == rack->r_ctl.rc_first_appl)
6055 			rack->r_ctl.rc_first_appl = l_rsm;
6056 	}
6057 #ifndef INVARIANTS
6058 	(void)RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, r_rsm);
6059 #else
6060 	rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, r_rsm);
6061 	if (rm != r_rsm) {
6062 		panic("removing head in rack:%p rsm:%p rm:%p",
6063 		      rack, r_rsm, rm);
6064 	}
6065 #endif
6066 	if ((r_rsm->r_limit_type == 0) && (l_rsm->r_limit_type != 0)) {
6067 		/* Transfer the split limit to the map we free */
6068 		r_rsm->r_limit_type = l_rsm->r_limit_type;
6069 		l_rsm->r_limit_type = 0;
6070 	}
6071 	rack_free(rack, r_rsm);
6072 	return (l_rsm);
6073 }
6074 
6075 /*
6076  * TLP Timer, here we simply setup what segment we want to
6077  * have the TLP expire on, the normal rack_output() will then
6078  * send it out.
6079  *
6080  * We return 1, saying don't proceed with rack_output only
6081  * when all timers have been stopped (destroyed PCB?).
6082  */
6083 static int
6084 rack_timeout_tlp(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t *doing_tlp)
6085 {
6086 	/*
6087 	 * Tail Loss Probe.
6088 	 */
6089 	struct rack_sendmap *rsm = NULL;
6090 #ifdef INVARIANTS
6091 	struct rack_sendmap *insret;
6092 #endif
6093 	struct socket *so;
6094 	uint32_t amm;
6095 	uint32_t out, avail;
6096 	int collapsed_win = 0;
6097 
6098 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6099 		return (1);
6100 	}
6101 	if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
6102 		/* Its not time yet */
6103 		return (0);
6104 	}
6105 	if (ctf_progress_timeout_check(tp, true)) {
6106 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
6107 		return (-ETIMEDOUT);	/* tcp_drop() */
6108 	}
6109 	/*
6110 	 * A TLP timer has expired. We have been idle for 2 rtts. So we now
6111 	 * need to figure out how to force a full MSS segment out.
6112 	 */
6113 	rack_log_to_event(rack, RACK_TO_FRM_TLP, NULL);
6114 	rack->r_ctl.retran_during_recovery = 0;
6115 	rack->r_ctl.dsack_byte_cnt = 0;
6116 	counter_u64_add(rack_tlp_tot, 1);
6117 	if (rack->r_state && (rack->r_state != tp->t_state))
6118 		rack_set_state(tp, rack);
6119 	so = tp->t_inpcb->inp_socket;
6120 	avail = sbavail(&so->so_snd);
6121 	out = tp->snd_max - tp->snd_una;
6122 	if ((out > tp->snd_wnd) || rack->rc_has_collapsed) {
6123 		/* special case, we need a retransmission */
6124 		collapsed_win = 1;
6125 		goto need_retran;
6126 	}
6127 	if (rack->r_ctl.dsack_persist && (rack->r_ctl.rc_tlp_cnt_out >= 1)) {
6128 		rack->r_ctl.dsack_persist--;
6129 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
6130 			rack->r_ctl.num_dsack = 0;
6131 		}
6132 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
6133 	}
6134 	if ((tp->t_flags & TF_GPUTINPROG) &&
6135 	    (rack->r_ctl.rc_tlp_cnt_out == 1)) {
6136 		/*
6137 		 * If this is the second in a row
6138 		 * TLP and we are doing a measurement
6139 		 * its time to abandon the measurement.
6140 		 * Something is likely broken on
6141 		 * the clients network and measuring a
6142 		 * broken network does us no good.
6143 		 */
6144 		tp->t_flags &= ~TF_GPUTINPROG;
6145 		rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
6146 					   rack->r_ctl.rc_gp_srtt /*flex1*/,
6147 					   tp->gput_seq,
6148 					   0, 0, 18, __LINE__, NULL, 0);
6149 	}
6150 	/*
6151 	 * Check our send oldest always settings, and if
6152 	 * there is an oldest to send jump to the need_retran.
6153 	 */
6154 	if (rack_always_send_oldest && (TAILQ_EMPTY(&rack->r_ctl.rc_tmap) == 0))
6155 		goto need_retran;
6156 
6157 	if (avail > out) {
6158 		/* New data is available */
6159 		amm = avail - out;
6160 		if (amm > ctf_fixed_maxseg(tp)) {
6161 			amm = ctf_fixed_maxseg(tp);
6162 			if ((amm + out) > tp->snd_wnd) {
6163 				/* We are rwnd limited */
6164 				goto need_retran;
6165 			}
6166 		} else if (amm < ctf_fixed_maxseg(tp)) {
6167 			/* not enough to fill a MTU */
6168 			goto need_retran;
6169 		}
6170 		if (IN_FASTRECOVERY(tp->t_flags)) {
6171 			/* Unlikely */
6172 			if (rack->rack_no_prr == 0) {
6173 				if (out + amm <= tp->snd_wnd) {
6174 					rack->r_ctl.rc_prr_sndcnt = amm;
6175 					rack->r_ctl.rc_tlp_new_data = amm;
6176 					rack_log_to_prr(rack, 4, 0, __LINE__);
6177 				}
6178 			} else
6179 				goto need_retran;
6180 		} else {
6181 			/* Set the send-new override */
6182 			if (out + amm <= tp->snd_wnd)
6183 				rack->r_ctl.rc_tlp_new_data = amm;
6184 			else
6185 				goto need_retran;
6186 		}
6187 		rack->r_ctl.rc_tlpsend = NULL;
6188 		counter_u64_add(rack_tlp_newdata, 1);
6189 		goto send;
6190 	}
6191 need_retran:
6192 	/*
6193 	 * Ok we need to arrange the last un-acked segment to be re-sent, or
6194 	 * optionally the first un-acked segment.
6195 	 */
6196 	if (collapsed_win == 0) {
6197 		if (rack_always_send_oldest)
6198 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
6199 		else {
6200 			rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6201 			if (rsm && (rsm->r_flags & (RACK_ACKED | RACK_HAS_FIN))) {
6202 				rsm = rack_find_high_nonack(rack, rsm);
6203 			}
6204 		}
6205 		if (rsm == NULL) {
6206 #ifdef TCP_BLACKBOX
6207 			tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
6208 #endif
6209 			goto out;
6210 		}
6211 	} else {
6212 		/*
6213 		 * We must find the last segment
6214 		 * that was acceptable by the client.
6215 		 */
6216 		RB_FOREACH_REVERSE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
6217 			if ((rsm->r_flags & RACK_RWND_COLLAPSED) == 0) {
6218 				/* Found one */
6219 				break;
6220 			}
6221 		}
6222 		if (rsm == NULL) {
6223 			/* None? if so send the first */
6224 			rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6225 			if (rsm == NULL) {
6226 #ifdef TCP_BLACKBOX
6227 				tcp_log_dump_tp_logbuf(tp, "nada counter trips", M_NOWAIT, true);
6228 #endif
6229 				goto out;
6230 			}
6231 		}
6232 	}
6233 	if ((rsm->r_end - rsm->r_start) > ctf_fixed_maxseg(tp)) {
6234 		/*
6235 		 * We need to split this the last segment in two.
6236 		 */
6237 		struct rack_sendmap *nrsm;
6238 
6239 		nrsm = rack_alloc_full_limit(rack);
6240 		if (nrsm == NULL) {
6241 			/*
6242 			 * No memory to split, we will just exit and punt
6243 			 * off to the RXT timer.
6244 			 */
6245 			goto out;
6246 		}
6247 		rack_clone_rsm(rack, nrsm, rsm,
6248 			       (rsm->r_end - ctf_fixed_maxseg(tp)));
6249 		rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
6250 #ifndef INVARIANTS
6251 		(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
6252 #else
6253 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
6254 		if (insret != NULL) {
6255 			panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
6256 			      nrsm, insret, rack, rsm);
6257 		}
6258 #endif
6259 		if (rsm->r_in_tmap) {
6260 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
6261 			nrsm->r_in_tmap = 1;
6262 		}
6263 		rsm = nrsm;
6264 	}
6265 	rack->r_ctl.rc_tlpsend = rsm;
6266 send:
6267 	/* Make sure output path knows we are doing a TLP */
6268 	*doing_tlp = 1;
6269 	rack->r_timer_override = 1;
6270 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
6271 	return (0);
6272 out:
6273 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
6274 	return (0);
6275 }
6276 
6277 /*
6278  * Delayed ack Timer, here we simply need to setup the
6279  * ACK_NOW flag and remove the DELACK flag. From there
6280  * the output routine will send the ack out.
6281  *
6282  * We only return 1, saying don't proceed, if all timers
6283  * are stopped (destroyed PCB?).
6284  */
6285 static int
6286 rack_timeout_delack(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6287 {
6288 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6289 		return (1);
6290 	}
6291 	rack_log_to_event(rack, RACK_TO_FRM_DELACK, NULL);
6292 	tp->t_flags &= ~TF_DELACK;
6293 	tp->t_flags |= TF_ACKNOW;
6294 	KMOD_TCPSTAT_INC(tcps_delack);
6295 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
6296 	return (0);
6297 }
6298 
6299 /*
6300  * Persists timer, here we simply send the
6301  * same thing as a keepalive will.
6302  * the one byte send.
6303  *
6304  * We only return 1, saying don't proceed, if all timers
6305  * are stopped (destroyed PCB?).
6306  */
6307 static int
6308 rack_timeout_persist(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6309 {
6310 	struct tcptemp *t_template;
6311 #ifdef INVARIANTS
6312 	struct inpcb *inp = tp->t_inpcb;
6313 #endif
6314 	int32_t retval = 1;
6315 
6316 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6317 		return (1);
6318 	}
6319 	if (rack->rc_in_persist == 0)
6320 		return (0);
6321 	if (ctf_progress_timeout_check(tp, false)) {
6322 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
6323 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
6324 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
6325 		return (-ETIMEDOUT);	/* tcp_drop() */
6326 	}
6327 	KASSERT(inp != NULL, ("%s: tp %p tp->t_inpcb == NULL", __func__, tp));
6328 	/*
6329 	 * Persistence timer into zero window. Force a byte to be output, if
6330 	 * possible.
6331 	 */
6332 	KMOD_TCPSTAT_INC(tcps_persisttimeo);
6333 	/*
6334 	 * Hack: if the peer is dead/unreachable, we do not time out if the
6335 	 * window is closed.  After a full backoff, drop the connection if
6336 	 * the idle time (no responses to probes) reaches the maximum
6337 	 * backoff that we would use if retransmitting.
6338 	 */
6339 	if (tp->t_rxtshift == TCP_MAXRXTSHIFT &&
6340 	    (ticks - tp->t_rcvtime >= tcp_maxpersistidle ||
6341 	     TICKS_2_USEC(ticks - tp->t_rcvtime) >= RACK_REXMTVAL(tp) * tcp_totbackoff)) {
6342 		KMOD_TCPSTAT_INC(tcps_persistdrop);
6343 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
6344 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
6345 		retval = -ETIMEDOUT;	/* tcp_drop() */
6346 		goto out;
6347 	}
6348 	if ((sbavail(&rack->rc_inp->inp_socket->so_snd) == 0) &&
6349 	    tp->snd_una == tp->snd_max)
6350 		rack_exit_persist(tp, rack, cts);
6351 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_PERSIT;
6352 	/*
6353 	 * If the user has closed the socket then drop a persisting
6354 	 * connection after a much reduced timeout.
6355 	 */
6356 	if (tp->t_state > TCPS_CLOSE_WAIT &&
6357 	    (ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) {
6358 		KMOD_TCPSTAT_INC(tcps_persistdrop);
6359 		tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
6360 		counter_u64_add(rack_persists_lost_ends, rack->r_ctl.persist_lost_ends);
6361 		retval = -ETIMEDOUT;	/* tcp_drop() */
6362 		goto out;
6363 	}
6364 	t_template = tcpip_maketemplate(rack->rc_inp);
6365 	if (t_template) {
6366 		/* only set it if we were answered */
6367 		if (rack->forced_ack == 0) {
6368 			rack->forced_ack = 1;
6369 			rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
6370 		} else {
6371 			rack->probe_not_answered = 1;
6372 			counter_u64_add(rack_persists_loss, 1);
6373 			rack->r_ctl.persist_lost_ends++;
6374 		}
6375 		counter_u64_add(rack_persists_sends, 1);
6376 		tcp_respond(tp, t_template->tt_ipgen,
6377 			    &t_template->tt_t, (struct mbuf *)NULL,
6378 			    tp->rcv_nxt, tp->snd_una - 1, 0);
6379 		/* This sends an ack */
6380 		if (tp->t_flags & TF_DELACK)
6381 			tp->t_flags &= ~TF_DELACK;
6382 		free(t_template, M_TEMP);
6383 	}
6384 	if (tp->t_rxtshift < TCP_MAXRXTSHIFT)
6385 		tp->t_rxtshift++;
6386 out:
6387 	rack_log_to_event(rack, RACK_TO_FRM_PERSIST, NULL);
6388 	rack_start_hpts_timer(rack, tp, cts,
6389 			      0, 0, 0);
6390 	return (retval);
6391 }
6392 
6393 /*
6394  * If a keepalive goes off, we had no other timers
6395  * happening. We always return 1 here since this
6396  * routine either drops the connection or sends
6397  * out a segment with respond.
6398  */
6399 static int
6400 rack_timeout_keepalive(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6401 {
6402 	struct tcptemp *t_template;
6403 	struct inpcb *inp;
6404 
6405 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6406 		return (1);
6407 	}
6408 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_KEEP;
6409 	inp = tp->t_inpcb;
6410 	rack_log_to_event(rack, RACK_TO_FRM_KEEP, NULL);
6411 	/*
6412 	 * Keep-alive timer went off; send something or drop connection if
6413 	 * idle for too long.
6414 	 */
6415 	KMOD_TCPSTAT_INC(tcps_keeptimeo);
6416 	if (tp->t_state < TCPS_ESTABLISHED)
6417 		goto dropit;
6418 	if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
6419 	    tp->t_state <= TCPS_CLOSING) {
6420 		if (ticks - tp->t_rcvtime >= TP_KEEPIDLE(tp) + TP_MAXIDLE(tp))
6421 			goto dropit;
6422 		/*
6423 		 * Send a packet designed to force a response if the peer is
6424 		 * up and reachable: either an ACK if the connection is
6425 		 * still alive, or an RST if the peer has closed the
6426 		 * connection due to timeout or reboot. Using sequence
6427 		 * number tp->snd_una-1 causes the transmitted zero-length
6428 		 * segment to lie outside the receive window; by the
6429 		 * protocol spec, this requires the correspondent TCP to
6430 		 * respond.
6431 		 */
6432 		KMOD_TCPSTAT_INC(tcps_keepprobe);
6433 		t_template = tcpip_maketemplate(inp);
6434 		if (t_template) {
6435 			if (rack->forced_ack == 0) {
6436 				rack->forced_ack = 1;
6437 				rack->r_ctl.forced_ack_ts = tcp_get_usecs(NULL);
6438 			} else {
6439 				rack->probe_not_answered = 1;
6440 			}
6441 			tcp_respond(tp, t_template->tt_ipgen,
6442 			    &t_template->tt_t, (struct mbuf *)NULL,
6443 			    tp->rcv_nxt, tp->snd_una - 1, 0);
6444 			free(t_template, M_TEMP);
6445 		}
6446 	}
6447 	rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
6448 	return (1);
6449 dropit:
6450 	KMOD_TCPSTAT_INC(tcps_keepdrops);
6451 	tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
6452 	return (-ETIMEDOUT);	/* tcp_drop() */
6453 }
6454 
6455 /*
6456  * Retransmit helper function, clear up all the ack
6457  * flags and take care of important book keeping.
6458  */
6459 static void
6460 rack_remxt_tmr(struct tcpcb *tp)
6461 {
6462 	/*
6463 	 * The retransmit timer went off, all sack'd blocks must be
6464 	 * un-acked.
6465 	 */
6466 	struct rack_sendmap *rsm, *trsm = NULL;
6467 	struct tcp_rack *rack;
6468 
6469 	rack = (struct tcp_rack *)tp->t_fb_ptr;
6470 	rack_timer_cancel(tp, rack, tcp_get_usecs(NULL), __LINE__);
6471 	rack_log_to_event(rack, RACK_TO_FRM_TMR, NULL);
6472 	if (rack->r_state && (rack->r_state != tp->t_state))
6473 		rack_set_state(tp, rack);
6474 	/*
6475 	 * Ideally we would like to be able to
6476 	 * mark SACK-PASS on anything not acked here.
6477 	 *
6478 	 * However, if we do that we would burst out
6479 	 * all that data 1ms apart. This would be unwise,
6480 	 * so for now we will just let the normal rxt timer
6481 	 * and tlp timer take care of it.
6482 	 *
6483 	 * Also we really need to stick them back in sequence
6484 	 * order. This way we send in the proper order and any
6485 	 * sacks that come floating in will "re-ack" the data.
6486 	 * To do this we zap the tmap with an INIT and then
6487 	 * walk through and place every rsm in the RB tree
6488 	 * back in its seq ordered place.
6489 	 */
6490 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
6491 	RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
6492 		rsm->r_dupack = 0;
6493 		rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
6494 		/* We must re-add it back to the tlist */
6495 		if (trsm == NULL) {
6496 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
6497 		} else {
6498 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, trsm, rsm, r_tnext);
6499 		}
6500 		rsm->r_in_tmap = 1;
6501 		trsm = rsm;
6502 		if (rsm->r_flags & RACK_ACKED)
6503 			rsm->r_flags |= RACK_WAS_ACKED;
6504 		rsm->r_flags &= ~(RACK_ACKED | RACK_SACK_PASSED | RACK_WAS_SACKPASS);
6505 		rsm->r_flags |= RACK_MUST_RXT;
6506 	}
6507 	/* Clear the count (we just un-acked them) */
6508 	rack->r_ctl.rc_last_timeout_snduna = tp->snd_una;
6509 	rack->r_ctl.rc_sacked = 0;
6510 	rack->r_ctl.rc_sacklast = NULL;
6511 	rack->r_ctl.rc_agg_delayed = 0;
6512 	rack->r_early = 0;
6513 	rack->r_ctl.rc_agg_early = 0;
6514 	rack->r_late = 0;
6515 	/* Clear the tlp rtx mark */
6516 	rack->r_ctl.rc_resend = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6517 	if (rack->r_ctl.rc_resend != NULL)
6518 		rack->r_ctl.rc_resend->r_flags |= RACK_TO_REXT;
6519 	rack->r_ctl.rc_prr_sndcnt = 0;
6520 	rack_log_to_prr(rack, 6, 0, __LINE__);
6521 	rack->r_timer_override = 1;
6522 	if ((((tp->t_flags & TF_SACK_PERMIT) == 0)
6523 #ifdef NETFLIX_EXP_DETECTION
6524 	    || (rack->sack_attack_disable != 0)
6525 #endif
6526 		    ) && ((tp->t_flags & TF_SENTFIN) == 0)) {
6527 		/*
6528 		 * For non-sack customers new data
6529 		 * needs to go out as retransmits until
6530 		 * we retransmit up to snd_max.
6531 		 */
6532 		rack->r_must_retran = 1;
6533 		rack->r_ctl.rc_out_at_rto = ctf_flight_size(rack->rc_tp,
6534 						rack->r_ctl.rc_sacked);
6535 	}
6536 	rack->r_ctl.rc_snd_max_at_rto = tp->snd_max;
6537 }
6538 
6539 static void
6540 rack_convert_rtts(struct tcpcb *tp)
6541 {
6542 	if (tp->t_srtt > 1) {
6543 		uint32_t val, frac;
6544 
6545 		val = tp->t_srtt >> TCP_RTT_SHIFT;
6546 		frac = tp->t_srtt & 0x1f;
6547 		tp->t_srtt = TICKS_2_USEC(val);
6548 		/*
6549 		 * frac is the fractional part of the srtt (if any)
6550 		 * but its in ticks and every bit represents
6551 		 * 1/32nd of a hz.
6552 		 */
6553 		if (frac) {
6554 			if (hz == 1000) {
6555 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_MSEC) / (uint64_t)TCP_RTT_SCALE);
6556 			} else {
6557 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_SEC) / ((uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE));
6558 			}
6559 			tp->t_srtt += frac;
6560 		}
6561 	}
6562 	if (tp->t_rttvar) {
6563 		uint32_t val, frac;
6564 
6565 		val = tp->t_rttvar >> TCP_RTTVAR_SHIFT;
6566 		frac = tp->t_rttvar & 0x1f;
6567 		tp->t_rttvar = TICKS_2_USEC(val);
6568 		/*
6569 		 * frac is the fractional part of the srtt (if any)
6570 		 * but its in ticks and every bit represents
6571 		 * 1/32nd of a hz.
6572 		 */
6573 		if (frac) {
6574 			if (hz == 1000) {
6575 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_MSEC) / (uint64_t)TCP_RTT_SCALE);
6576 			} else {
6577 				frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_SEC) / ((uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE));
6578 			}
6579 			tp->t_rttvar += frac;
6580 		}
6581 	}
6582 	tp->t_rxtcur = RACK_REXMTVAL(tp);
6583 	if (TCPS_HAVEESTABLISHED(tp->t_state)) {
6584 		tp->t_rxtcur += TICKS_2_USEC(tcp_rexmit_slop);
6585 	}
6586 	if (tp->t_rxtcur > rack_rto_max) {
6587 		tp->t_rxtcur = rack_rto_max;
6588 	}
6589 }
6590 
6591 static void
6592 rack_cc_conn_init(struct tcpcb *tp)
6593 {
6594 	struct tcp_rack *rack;
6595 	uint32_t srtt;
6596 
6597 	rack = (struct tcp_rack *)tp->t_fb_ptr;
6598 	srtt = tp->t_srtt;
6599 	cc_conn_init(tp);
6600 	/*
6601 	 * Now convert to rack's internal format,
6602 	 * if required.
6603 	 */
6604 	if ((srtt == 0) && (tp->t_srtt != 0))
6605 		rack_convert_rtts(tp);
6606 	/*
6607 	 * We want a chance to stay in slowstart as
6608 	 * we create a connection. TCP spec says that
6609 	 * initially ssthresh is infinite. For our
6610 	 * purposes that is the snd_wnd.
6611 	 */
6612 	if (tp->snd_ssthresh < tp->snd_wnd) {
6613 		tp->snd_ssthresh = tp->snd_wnd;
6614 	}
6615 	/*
6616 	 * We also want to assure a IW worth of
6617 	 * data can get inflight.
6618 	 */
6619 	if (rc_init_window(rack) < tp->snd_cwnd)
6620 		tp->snd_cwnd = rc_init_window(rack);
6621 }
6622 
6623 /*
6624  * Re-transmit timeout! If we drop the PCB we will return 1, otherwise
6625  * we will setup to retransmit the lowest seq number outstanding.
6626  */
6627 static int
6628 rack_timeout_rxt(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts)
6629 {
6630 	int32_t rexmt;
6631 	int32_t retval = 0;
6632 	bool isipv6;
6633 
6634 	if (tp->t_timers->tt_flags & TT_STOPPED) {
6635 		return (1);
6636 	}
6637 	if ((tp->t_flags & TF_GPUTINPROG) &&
6638 	    (tp->t_rxtshift)) {
6639 		/*
6640 		 * We have had a second timeout
6641 		 * measurements on successive rxt's are not profitable.
6642 		 * It is unlikely to be of any use (the network is
6643 		 * broken or the client went away).
6644 		 */
6645 		tp->t_flags &= ~TF_GPUTINPROG;
6646 		rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
6647 					   rack->r_ctl.rc_gp_srtt /*flex1*/,
6648 					   tp->gput_seq,
6649 					   0, 0, 18, __LINE__, NULL, 0);
6650 	}
6651 	if (ctf_progress_timeout_check(tp, false)) {
6652 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
6653 		rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
6654 		return (-ETIMEDOUT);	/* tcp_drop() */
6655 	}
6656 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_RXT;
6657 	rack->r_ctl.retran_during_recovery = 0;
6658 	rack->r_ctl.dsack_byte_cnt = 0;
6659 	if (IN_FASTRECOVERY(tp->t_flags))
6660 		tp->t_flags |= TF_WASFRECOVERY;
6661 	else
6662 		tp->t_flags &= ~TF_WASFRECOVERY;
6663 	if (IN_CONGRECOVERY(tp->t_flags))
6664 		tp->t_flags |= TF_WASCRECOVERY;
6665 	else
6666 		tp->t_flags &= ~TF_WASCRECOVERY;
6667 	if (TCPS_HAVEESTABLISHED(tp->t_state) &&
6668 	    (tp->snd_una == tp->snd_max)) {
6669 		/* Nothing outstanding .. nothing to do */
6670 		return (0);
6671 	}
6672 	if (rack->r_ctl.dsack_persist) {
6673 		rack->r_ctl.dsack_persist--;
6674 		if (rack->r_ctl.num_dsack && (rack->r_ctl.dsack_persist == 0)) {
6675 			rack->r_ctl.num_dsack = 0;
6676 		}
6677 		rack_log_dsack_event(rack, 1, __LINE__, 0, 0);
6678 	}
6679 	/*
6680 	 * Rack can only run one timer  at a time, so we cannot
6681 	 * run a KEEPINIT (gating SYN sending) and a retransmit
6682 	 * timer for the SYN. So if we are in a front state and
6683 	 * have a KEEPINIT timer we need to check the first transmit
6684 	 * against now to see if we have exceeded the KEEPINIT time
6685 	 * (if one is set).
6686 	 */
6687 	if ((TCPS_HAVEESTABLISHED(tp->t_state) == 0) &&
6688 	    (TP_KEEPINIT(tp) != 0)) {
6689 		struct rack_sendmap *rsm;
6690 
6691 		rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
6692 		if (rsm) {
6693 			/* Ok we have something outstanding to test keepinit with */
6694 			if ((TSTMP_GT(cts, (uint32_t)rsm->r_tim_lastsent[0])) &&
6695 			    ((cts - (uint32_t)rsm->r_tim_lastsent[0]) >= TICKS_2_USEC(TP_KEEPINIT(tp)))) {
6696 				/* We have exceeded the KEEPINIT time */
6697 				tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
6698 				goto drop_it;
6699 			}
6700 		}
6701 	}
6702 	/*
6703 	 * Retransmission timer went off.  Message has not been acked within
6704 	 * retransmit interval.  Back off to a longer retransmit interval
6705 	 * and retransmit one segment.
6706 	 */
6707 	rack_remxt_tmr(tp);
6708 	if ((rack->r_ctl.rc_resend == NULL) ||
6709 	    ((rack->r_ctl.rc_resend->r_flags & RACK_RWND_COLLAPSED) == 0)) {
6710 		/*
6711 		 * If the rwnd collapsed on
6712 		 * the one we are retransmitting
6713 		 * it does not count against the
6714 		 * rxt count.
6715 		 */
6716 		tp->t_rxtshift++;
6717 	}
6718 	if (tp->t_rxtshift > TCP_MAXRXTSHIFT) {
6719 		tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
6720 drop_it:
6721 		tp->t_rxtshift = TCP_MAXRXTSHIFT;
6722 		KMOD_TCPSTAT_INC(tcps_timeoutdrop);
6723 		/* XXXGL: previously t_softerror was casted to uint16_t */
6724 		MPASS(tp->t_softerror >= 0);
6725 		retval = tp->t_softerror ? -tp->t_softerror : -ETIMEDOUT;
6726 		goto out;	/* tcp_drop() */
6727 	}
6728 	if (tp->t_state == TCPS_SYN_SENT) {
6729 		/*
6730 		 * If the SYN was retransmitted, indicate CWND to be limited
6731 		 * to 1 segment in cc_conn_init().
6732 		 */
6733 		tp->snd_cwnd = 1;
6734 	} else if (tp->t_rxtshift == 1) {
6735 		/*
6736 		 * first retransmit; record ssthresh and cwnd so they can be
6737 		 * recovered if this turns out to be a "bad" retransmit. A
6738 		 * retransmit is considered "bad" if an ACK for this segment
6739 		 * is received within RTT/2 interval; the assumption here is
6740 		 * that the ACK was already in flight.  See "On Estimating
6741 		 * End-to-End Network Path Properties" by Allman and Paxson
6742 		 * for more details.
6743 		 */
6744 		tp->snd_cwnd_prev = tp->snd_cwnd;
6745 		tp->snd_ssthresh_prev = tp->snd_ssthresh;
6746 		tp->snd_recover_prev = tp->snd_recover;
6747 		tp->t_badrxtwin = ticks + (USEC_2_TICKS(tp->t_srtt)/2);
6748 		tp->t_flags |= TF_PREVVALID;
6749 	} else if ((tp->t_flags & TF_RCVD_TSTMP) == 0)
6750 		tp->t_flags &= ~TF_PREVVALID;
6751 	KMOD_TCPSTAT_INC(tcps_rexmttimeo);
6752 	if ((tp->t_state == TCPS_SYN_SENT) ||
6753 	    (tp->t_state == TCPS_SYN_RECEIVED))
6754 		rexmt = RACK_INITIAL_RTO * tcp_backoff[tp->t_rxtshift];
6755 	else
6756 		rexmt = max(rack_rto_min, (tp->t_srtt + (tp->t_rttvar << 2))) * tcp_backoff[tp->t_rxtshift];
6757 
6758 	RACK_TCPT_RANGESET(tp->t_rxtcur, rexmt,
6759 	   max(rack_rto_min, rexmt), rack_rto_max, rack->r_ctl.timer_slop);
6760 	/*
6761 	 * We enter the path for PLMTUD if connection is established or, if
6762 	 * connection is FIN_WAIT_1 status, reason for the last is that if
6763 	 * amount of data we send is very small, we could send it in couple
6764 	 * of packets and process straight to FIN. In that case we won't
6765 	 * catch ESTABLISHED state.
6766 	 */
6767 #ifdef INET6
6768 	isipv6 = (tp->t_inpcb->inp_vflag & INP_IPV6) ? true : false;
6769 #else
6770 	isipv6 = false;
6771 #endif
6772 	if (((V_tcp_pmtud_blackhole_detect == 1) ||
6773 	    (V_tcp_pmtud_blackhole_detect == 2 && !isipv6) ||
6774 	    (V_tcp_pmtud_blackhole_detect == 3 && isipv6)) &&
6775 	    ((tp->t_state == TCPS_ESTABLISHED) ||
6776 	    (tp->t_state == TCPS_FIN_WAIT_1))) {
6777 		/*
6778 		 * Idea here is that at each stage of mtu probe (usually,
6779 		 * 1448 -> 1188 -> 524) should be given 2 chances to recover
6780 		 * before further clamping down. 'tp->t_rxtshift % 2 == 0'
6781 		 * should take care of that.
6782 		 */
6783 		if (((tp->t_flags2 & (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) ==
6784 		    (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) &&
6785 		    (tp->t_rxtshift >= 2 && tp->t_rxtshift < 6 &&
6786 		    tp->t_rxtshift % 2 == 0)) {
6787 			/*
6788 			 * Enter Path MTU Black-hole Detection mechanism: -
6789 			 * Disable Path MTU Discovery (IP "DF" bit). -
6790 			 * Reduce MTU to lower value than what we negotiated
6791 			 * with peer.
6792 			 */
6793 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) == 0) {
6794 				/* Record that we may have found a black hole. */
6795 				tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE;
6796 				/* Keep track of previous MSS. */
6797 				tp->t_pmtud_saved_maxseg = tp->t_maxseg;
6798 			}
6799 
6800 			/*
6801 			 * Reduce the MSS to blackhole value or to the
6802 			 * default in an attempt to retransmit.
6803 			 */
6804 #ifdef INET6
6805 			if (isipv6 &&
6806 			    tp->t_maxseg > V_tcp_v6pmtud_blackhole_mss) {
6807 				/* Use the sysctl tuneable blackhole MSS. */
6808 				tp->t_maxseg = V_tcp_v6pmtud_blackhole_mss;
6809 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
6810 			} else if (isipv6) {
6811 				/* Use the default MSS. */
6812 				tp->t_maxseg = V_tcp_v6mssdflt;
6813 				/*
6814 				 * Disable Path MTU Discovery when we switch
6815 				 * to minmss.
6816 				 */
6817 				tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
6818 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
6819 			}
6820 #endif
6821 #if defined(INET6) && defined(INET)
6822 			else
6823 #endif
6824 #ifdef INET
6825 			if (tp->t_maxseg > V_tcp_pmtud_blackhole_mss) {
6826 				/* Use the sysctl tuneable blackhole MSS. */
6827 				tp->t_maxseg = V_tcp_pmtud_blackhole_mss;
6828 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
6829 			} else {
6830 				/* Use the default MSS. */
6831 				tp->t_maxseg = V_tcp_mssdflt;
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 		} else {
6841 			/*
6842 			 * If further retransmissions are still unsuccessful
6843 			 * with a lowered MTU, maybe this isn't a blackhole
6844 			 * and we restore the previous MSS and blackhole
6845 			 * detection flags. The limit '6' is determined by
6846 			 * giving each probe stage (1448, 1188, 524) 2
6847 			 * chances to recover.
6848 			 */
6849 			if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) &&
6850 			    (tp->t_rxtshift >= 6)) {
6851 				tp->t_flags2 |= TF2_PLPMTU_PMTUD;
6852 				tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE;
6853 				tp->t_maxseg = tp->t_pmtud_saved_maxseg;
6854 				KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_failed);
6855 			}
6856 		}
6857 	}
6858 	/*
6859 	 * Disable RFC1323 and SACK if we haven't got any response to
6860 	 * our third SYN to work-around some broken terminal servers
6861 	 * (most of which have hopefully been retired) that have bad VJ
6862 	 * header compression code which trashes TCP segments containing
6863 	 * unknown-to-them TCP options.
6864 	 */
6865 	if (tcp_rexmit_drop_options && (tp->t_state == TCPS_SYN_SENT) &&
6866 	    (tp->t_rxtshift == 3))
6867 		tp->t_flags &= ~(TF_REQ_SCALE|TF_REQ_TSTMP|TF_SACK_PERMIT);
6868 	/*
6869 	 * If we backed off this far, our srtt estimate is probably bogus.
6870 	 * Clobber it so we'll take the next rtt measurement as our srtt;
6871 	 * move the current srtt into rttvar to keep the current retransmit
6872 	 * times until then.
6873 	 */
6874 	if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
6875 #ifdef INET6
6876 		if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0)
6877 			in6_losing(tp->t_inpcb);
6878 		else
6879 #endif
6880 			in_losing(tp->t_inpcb);
6881 		tp->t_rttvar += tp->t_srtt;
6882 		tp->t_srtt = 0;
6883 	}
6884 	sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
6885 	tp->snd_recover = tp->snd_max;
6886 	tp->t_flags |= TF_ACKNOW;
6887 	tp->t_rtttime = 0;
6888 	rack_cong_signal(tp, CC_RTO, tp->snd_una, __LINE__);
6889 out:
6890 	return (retval);
6891 }
6892 
6893 static int
6894 rack_process_timers(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, uint8_t hpts_calling, uint8_t *doing_tlp)
6895 {
6896 	int32_t ret = 0;
6897 	int32_t timers = (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK);
6898 
6899 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
6900 	    (tp->t_flags & TF_GPUTINPROG)) {
6901 		/*
6902 		 * We have a goodput in progress
6903 		 * and we have entered a late state.
6904 		 * Do we have enough data in the sb
6905 		 * to handle the GPUT request?
6906 		 */
6907 		uint32_t bytes;
6908 
6909 		bytes = tp->gput_ack - tp->gput_seq;
6910 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
6911 			bytes += tp->gput_seq - tp->snd_una;
6912 		if (bytes > sbavail(&tp->t_inpcb->inp_socket->so_snd)) {
6913 			/*
6914 			 * There are not enough bytes in the socket
6915 			 * buffer that have been sent to cover this
6916 			 * measurement. Cancel it.
6917 			 */
6918 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
6919 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
6920 						   tp->gput_seq,
6921 						   0, 0, 18, __LINE__, NULL, 0);
6922 			tp->t_flags &= ~TF_GPUTINPROG;
6923 		}
6924 	}
6925 	if (timers == 0) {
6926 		return (0);
6927 	}
6928 	if (tp->t_state == TCPS_LISTEN) {
6929 		/* no timers on listen sockets */
6930 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)
6931 			return (0);
6932 		return (1);
6933 	}
6934 	if ((timers & PACE_TMR_RACK) &&
6935 	    rack->rc_on_min_to) {
6936 		/*
6937 		 * For the rack timer when we
6938 		 * are on a min-timeout (which means rrr_conf = 3)
6939 		 * we don't want to check the timer. It may
6940 		 * be going off for a pace and thats ok we
6941 		 * want to send the retransmit (if its ready).
6942 		 *
6943 		 * If its on a normal rack timer (non-min) then
6944 		 * we will check if its expired.
6945 		 */
6946 		goto skip_time_check;
6947 	}
6948 	if (TSTMP_LT(cts, rack->r_ctl.rc_timer_exp)) {
6949 		uint32_t left;
6950 
6951 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
6952 			ret = -1;
6953 			rack_log_to_processing(rack, cts, ret, 0);
6954 			return (0);
6955 		}
6956 		if (hpts_calling == 0) {
6957 			/*
6958 			 * A user send or queued mbuf (sack) has called us? We
6959 			 * return 0 and let the pacing guards
6960 			 * deal with it if they should or
6961 			 * should not cause a send.
6962 			 */
6963 			ret = -2;
6964 			rack_log_to_processing(rack, cts, ret, 0);
6965 			return (0);
6966 		}
6967 		/*
6968 		 * Ok our timer went off early and we are not paced false
6969 		 * alarm, go back to sleep.
6970 		 */
6971 		ret = -3;
6972 		left = rack->r_ctl.rc_timer_exp - cts;
6973 		tcp_hpts_insert(tp->t_inpcb, HPTS_MS_TO_SLOTS(left));
6974 		rack_log_to_processing(rack, cts, ret, left);
6975 		return (1);
6976 	}
6977 skip_time_check:
6978 	rack->rc_tmr_stopped = 0;
6979 	rack->r_ctl.rc_hpts_flags &= ~PACE_TMR_MASK;
6980 	if (timers & PACE_TMR_DELACK) {
6981 		ret = rack_timeout_delack(tp, rack, cts);
6982 	} else if (timers & PACE_TMR_RACK) {
6983 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
6984 		rack->r_fast_output = 0;
6985 		ret = rack_timeout_rack(tp, rack, cts);
6986 	} else if (timers & PACE_TMR_TLP) {
6987 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
6988 		ret = rack_timeout_tlp(tp, rack, cts, doing_tlp);
6989 	} else if (timers & PACE_TMR_RXT) {
6990 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
6991 		rack->r_fast_output = 0;
6992 		ret = rack_timeout_rxt(tp, rack, cts);
6993 	} else if (timers & PACE_TMR_PERSIT) {
6994 		ret = rack_timeout_persist(tp, rack, cts);
6995 	} else if (timers & PACE_TMR_KEEP) {
6996 		ret = rack_timeout_keepalive(tp, rack, cts);
6997 	}
6998 	rack_log_to_processing(rack, cts, ret, timers);
6999 	return (ret);
7000 }
7001 
7002 static void
7003 rack_timer_cancel(struct tcpcb *tp, struct tcp_rack *rack, uint32_t cts, int line)
7004 {
7005 	struct timeval tv;
7006 	uint32_t us_cts, flags_on_entry;
7007 	uint8_t hpts_removed = 0;
7008 
7009 	flags_on_entry = rack->r_ctl.rc_hpts_flags;
7010 	us_cts = tcp_get_usecs(&tv);
7011 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
7012 	    ((TSTMP_GEQ(us_cts, rack->r_ctl.rc_last_output_to)) ||
7013 	     ((tp->snd_max - tp->snd_una) == 0))) {
7014 		tcp_hpts_remove(rack->rc_inp);
7015 		hpts_removed = 1;
7016 		/* If we were not delayed cancel out the flag. */
7017 		if ((tp->snd_max - tp->snd_una) == 0)
7018 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
7019 		rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
7020 	}
7021 	if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
7022 		rack->rc_tmr_stopped = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
7023 		if (tcp_in_hpts(rack->rc_inp) &&
7024 		    ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)) {
7025 			/*
7026 			 * Canceling timer's when we have no output being
7027 			 * paced. We also must remove ourselves from the
7028 			 * hpts.
7029 			 */
7030 			tcp_hpts_remove(rack->rc_inp);
7031 			hpts_removed = 1;
7032 		}
7033 		rack->r_ctl.rc_hpts_flags &= ~(PACE_TMR_MASK);
7034 	}
7035 	if (hpts_removed == 0)
7036 		rack_log_to_cancel(rack, hpts_removed, line, us_cts, &tv, flags_on_entry);
7037 }
7038 
7039 static void
7040 rack_timer_stop(struct tcpcb *tp, uint32_t timer_type)
7041 {
7042 	return;
7043 }
7044 
7045 static int
7046 rack_stopall(struct tcpcb *tp)
7047 {
7048 	struct tcp_rack *rack;
7049 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7050 	rack->t_timers_stopped = 1;
7051 	return (0);
7052 }
7053 
7054 static void
7055 rack_timer_activate(struct tcpcb *tp, uint32_t timer_type, uint32_t delta)
7056 {
7057 	return;
7058 }
7059 
7060 static int
7061 rack_timer_active(struct tcpcb *tp, uint32_t timer_type)
7062 {
7063 	return (0);
7064 }
7065 
7066 static void
7067 rack_stop_all_timers(struct tcpcb *tp)
7068 {
7069 	struct tcp_rack *rack;
7070 
7071 	/*
7072 	 * Assure no timers are running.
7073 	 */
7074 	if (tcp_timer_active(tp, TT_PERSIST)) {
7075 		/* We enter in persists, set the flag appropriately */
7076 		rack = (struct tcp_rack *)tp->t_fb_ptr;
7077 		rack->rc_in_persist = 1;
7078 	}
7079 	tcp_timer_suspend(tp, TT_PERSIST);
7080 	tcp_timer_suspend(tp, TT_REXMT);
7081 	tcp_timer_suspend(tp, TT_KEEP);
7082 	tcp_timer_suspend(tp, TT_DELACK);
7083 }
7084 
7085 static void
7086 rack_update_rsm(struct tcpcb *tp, struct tcp_rack *rack,
7087     struct rack_sendmap *rsm, uint64_t ts, uint16_t add_flag)
7088 {
7089 	int32_t idx;
7090 
7091 	rsm->r_rtr_cnt++;
7092 	rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
7093 	rsm->r_dupack = 0;
7094 	if (rsm->r_rtr_cnt > RACK_NUM_OF_RETRANS) {
7095 		rsm->r_rtr_cnt = RACK_NUM_OF_RETRANS;
7096 		rsm->r_flags |= RACK_OVERMAX;
7097 	}
7098 	if ((rsm->r_rtr_cnt > 1) && ((rsm->r_flags & RACK_TLP) == 0)) {
7099 		rack->r_ctl.rc_holes_rxt += (rsm->r_end - rsm->r_start);
7100 		rsm->r_rtr_bytes += (rsm->r_end - rsm->r_start);
7101 	}
7102 	idx = rsm->r_rtr_cnt - 1;
7103 	rsm->r_tim_lastsent[idx] = ts;
7104 	/*
7105 	 * Here we don't add in the len of send, since its already
7106 	 * in snduna <->snd_max.
7107 	 */
7108 	rsm->r_fas = ctf_flight_size(rack->rc_tp,
7109 				     rack->r_ctl.rc_sacked);
7110 	if (rsm->r_flags & RACK_ACKED) {
7111 		/* Problably MTU discovery messing with us */
7112 		rsm->r_flags &= ~RACK_ACKED;
7113 		rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
7114 	}
7115 	if (rsm->r_in_tmap) {
7116 		TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7117 		rsm->r_in_tmap = 0;
7118 	}
7119 	TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7120 	rsm->r_in_tmap = 1;
7121 	/* Take off the must retransmit flag, if its on */
7122 	if (rsm->r_flags & RACK_MUST_RXT) {
7123 		if (rack->r_must_retran)
7124 			rack->r_ctl.rc_out_at_rto -= (rsm->r_end - rsm->r_start);
7125 		if (SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) {
7126 			/*
7127 			 * We have retransmitted all we need. Clear
7128 			 * any must retransmit flags.
7129 			 */
7130 			rack->r_must_retran = 0;
7131 			rack->r_ctl.rc_out_at_rto = 0;
7132 		}
7133 		rsm->r_flags &= ~RACK_MUST_RXT;
7134 	}
7135 	if (rsm->r_flags & RACK_SACK_PASSED) {
7136 		/* We have retransmitted due to the SACK pass */
7137 		rsm->r_flags &= ~RACK_SACK_PASSED;
7138 		rsm->r_flags |= RACK_WAS_SACKPASS;
7139 	}
7140 }
7141 
7142 static uint32_t
7143 rack_update_entry(struct tcpcb *tp, struct tcp_rack *rack,
7144     struct rack_sendmap *rsm, uint64_t ts, int32_t *lenp, uint16_t add_flag)
7145 {
7146 	/*
7147 	 * We (re-)transmitted starting at rsm->r_start for some length
7148 	 * (possibly less than r_end.
7149 	 */
7150 	struct rack_sendmap *nrsm;
7151 #ifdef INVARIANTS
7152 	struct rack_sendmap *insret;
7153 #endif
7154 	uint32_t c_end;
7155 	int32_t len;
7156 
7157 	len = *lenp;
7158 	c_end = rsm->r_start + len;
7159 	if (SEQ_GEQ(c_end, rsm->r_end)) {
7160 		/*
7161 		 * We retransmitted the whole piece or more than the whole
7162 		 * slopping into the next rsm.
7163 		 */
7164 		rack_update_rsm(tp, rack, rsm, ts, add_flag);
7165 		if (c_end == rsm->r_end) {
7166 			*lenp = 0;
7167 			return (0);
7168 		} else {
7169 			int32_t act_len;
7170 
7171 			/* Hangs over the end return whats left */
7172 			act_len = rsm->r_end - rsm->r_start;
7173 			*lenp = (len - act_len);
7174 			return (rsm->r_end);
7175 		}
7176 		/* We don't get out of this block. */
7177 	}
7178 	/*
7179 	 * Here we retransmitted less than the whole thing which means we
7180 	 * have to split this into what was transmitted and what was not.
7181 	 */
7182 	nrsm = rack_alloc_full_limit(rack);
7183 	if (nrsm == NULL) {
7184 		/*
7185 		 * We can't get memory, so lets not proceed.
7186 		 */
7187 		*lenp = 0;
7188 		return (0);
7189 	}
7190 	/*
7191 	 * So here we are going to take the original rsm and make it what we
7192 	 * retransmitted. nrsm will be the tail portion we did not
7193 	 * retransmit. For example say the chunk was 1, 11 (10 bytes). And
7194 	 * we retransmitted 5 bytes i.e. 1, 5. The original piece shrinks to
7195 	 * 1, 6 and the new piece will be 6, 11.
7196 	 */
7197 	rack_clone_rsm(rack, nrsm, rsm, c_end);
7198 	nrsm->r_dupack = 0;
7199 	rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
7200 #ifndef INVARIANTS
7201 	(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
7202 #else
7203 	insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
7204 	if (insret != NULL) {
7205 		panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
7206 		      nrsm, insret, rack, rsm);
7207 	}
7208 #endif
7209 	if (rsm->r_in_tmap) {
7210 		TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7211 		nrsm->r_in_tmap = 1;
7212 	}
7213 	rsm->r_flags &= (~RACK_HAS_FIN);
7214 	rack_update_rsm(tp, rack, rsm, ts, add_flag);
7215 	/* Log a split of rsm into rsm and nrsm */
7216 	rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
7217 	*lenp = 0;
7218 	return (0);
7219 }
7220 
7221 static void
7222 rack_log_output(struct tcpcb *tp, struct tcpopt *to, int32_t len,
7223 		uint32_t seq_out, uint16_t th_flags, int32_t err, uint64_t cts,
7224 		struct rack_sendmap *hintrsm, uint16_t add_flag, struct mbuf *s_mb, uint32_t s_moff, int hw_tls)
7225 {
7226 	struct tcp_rack *rack;
7227 	struct rack_sendmap *rsm, *nrsm, fe;
7228 #ifdef INVARIANTS
7229 	struct rack_sendmap *insret;
7230 #endif
7231 	register uint32_t snd_max, snd_una;
7232 
7233 	/*
7234 	 * Add to the RACK log of packets in flight or retransmitted. If
7235 	 * there is a TS option we will use the TS echoed, if not we will
7236 	 * grab a TS.
7237 	 *
7238 	 * Retransmissions will increment the count and move the ts to its
7239 	 * proper place. Note that if options do not include TS's then we
7240 	 * won't be able to effectively use the ACK for an RTT on a retran.
7241 	 *
7242 	 * Notes about r_start and r_end. Lets consider a send starting at
7243 	 * sequence 1 for 10 bytes. In such an example the r_start would be
7244 	 * 1 (starting sequence) but the r_end would be r_start+len i.e. 11.
7245 	 * This means that r_end is actually the first sequence for the next
7246 	 * slot (11).
7247 	 *
7248 	 */
7249 	/*
7250 	 * If err is set what do we do XXXrrs? should we not add the thing?
7251 	 * -- i.e. return if err != 0 or should we pretend we sent it? --
7252 	 * i.e. proceed with add ** do this for now.
7253 	 */
7254 	INP_WLOCK_ASSERT(tp->t_inpcb);
7255 	if (err)
7256 		/*
7257 		 * We don't log errors -- we could but snd_max does not
7258 		 * advance in this case either.
7259 		 */
7260 		return;
7261 
7262 	if (th_flags & TH_RST) {
7263 		/*
7264 		 * We don't log resets and we return immediately from
7265 		 * sending
7266 		 */
7267 		return;
7268 	}
7269 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7270 	snd_una = tp->snd_una;
7271 	snd_max = tp->snd_max;
7272 	if (th_flags & (TH_SYN | TH_FIN)) {
7273 		/*
7274 		 * The call to rack_log_output is made before bumping
7275 		 * snd_max. This means we can record one extra byte on a SYN
7276 		 * or FIN if seq_out is adding more on and a FIN is present
7277 		 * (and we are not resending).
7278 		 */
7279 		if ((th_flags & TH_SYN) && (seq_out == tp->iss))
7280 			len++;
7281 		if (th_flags & TH_FIN)
7282 			len++;
7283 		if (SEQ_LT(snd_max, tp->snd_nxt)) {
7284 			/*
7285 			 * The add/update as not been done for the FIN/SYN
7286 			 * yet.
7287 			 */
7288 			snd_max = tp->snd_nxt;
7289 		}
7290 	}
7291 	if (SEQ_LEQ((seq_out + len), snd_una)) {
7292 		/* Are sending an old segment to induce an ack (keep-alive)? */
7293 		return;
7294 	}
7295 	if (SEQ_LT(seq_out, snd_una)) {
7296 		/* huh? should we panic? */
7297 		uint32_t end;
7298 
7299 		end = seq_out + len;
7300 		seq_out = snd_una;
7301 		if (SEQ_GEQ(end, seq_out))
7302 			len = end - seq_out;
7303 		else
7304 			len = 0;
7305 	}
7306 	if (len == 0) {
7307 		/* We don't log zero window probes */
7308 		return;
7309 	}
7310 	if (IN_FASTRECOVERY(tp->t_flags)) {
7311 		rack->r_ctl.rc_prr_out += len;
7312 	}
7313 	/* First question is it a retransmission or new? */
7314 	if (seq_out == snd_max) {
7315 		/* Its new */
7316 again:
7317 		rsm = rack_alloc(rack);
7318 		if (rsm == NULL) {
7319 			/*
7320 			 * Hmm out of memory and the tcb got destroyed while
7321 			 * we tried to wait.
7322 			 */
7323 			return;
7324 		}
7325 		if (th_flags & TH_FIN) {
7326 			rsm->r_flags = RACK_HAS_FIN|add_flag;
7327 		} else {
7328 			rsm->r_flags = add_flag;
7329 		}
7330 		if (hw_tls)
7331 			rsm->r_hw_tls = 1;
7332 		rsm->r_tim_lastsent[0] = cts;
7333 		rsm->r_rtr_cnt = 1;
7334 		rsm->r_rtr_bytes = 0;
7335 		if (th_flags & TH_SYN) {
7336 			/* The data space is one beyond snd_una */
7337 			rsm->r_flags |= RACK_HAS_SYN;
7338 		}
7339 		rsm->r_start = seq_out;
7340 		rsm->r_end = rsm->r_start + len;
7341 		rsm->r_dupack = 0;
7342 		/*
7343 		 * save off the mbuf location that
7344 		 * sndmbuf_noadv returned (which is
7345 		 * where we started copying from)..
7346 		 */
7347 		rsm->m = s_mb;
7348 		rsm->soff = s_moff;
7349 		/*
7350 		 * Here we do add in the len of send, since its not yet
7351 		 * reflected in in snduna <->snd_max
7352 		 */
7353 		rsm->r_fas = (ctf_flight_size(rack->rc_tp,
7354 					      rack->r_ctl.rc_sacked) +
7355 			      (rsm->r_end - rsm->r_start));
7356 		/* rsm->m will be NULL if RACK_HAS_SYN or RACK_HAS_FIN is set */
7357 		if (rsm->m) {
7358 			if (rsm->m->m_len <= rsm->soff) {
7359 				/*
7360 				 * XXXrrs Question, will this happen?
7361 				 *
7362 				 * If sbsndptr is set at the correct place
7363 				 * then s_moff should always be somewhere
7364 				 * within rsm->m. But if the sbsndptr was
7365 				 * off then that won't be true. If it occurs
7366 				 * we need to walkout to the correct location.
7367 				 */
7368 				struct mbuf *lm;
7369 
7370 				lm = rsm->m;
7371 				while (lm->m_len <= rsm->soff) {
7372 					rsm->soff -= lm->m_len;
7373 					lm = lm->m_next;
7374 					KASSERT(lm != NULL, ("%s rack:%p lm goes null orig_off:%u origmb:%p rsm->soff:%u",
7375 							     __func__, rack, s_moff, s_mb, rsm->soff));
7376 				}
7377 				rsm->m = lm;
7378 			}
7379 			rsm->orig_m_len = rsm->m->m_len;
7380 		} else
7381 			rsm->orig_m_len = 0;
7382 		rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
7383 		/* Log a new rsm */
7384 		rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_NEW, 0, __LINE__);
7385 #ifndef INVARIANTS
7386 		(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
7387 #else
7388 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
7389 		if (insret != NULL) {
7390 			panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
7391 			      nrsm, insret, rack, rsm);
7392 		}
7393 #endif
7394 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
7395 		rsm->r_in_tmap = 1;
7396 		/*
7397 		 * Special case detection, is there just a single
7398 		 * packet outstanding when we are not in recovery?
7399 		 *
7400 		 * If this is true mark it so.
7401 		 */
7402 		if ((IN_FASTRECOVERY(tp->t_flags) == 0) &&
7403 		    (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) == ctf_fixed_maxseg(tp))) {
7404 			struct rack_sendmap *prsm;
7405 
7406 			prsm = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
7407 			if (prsm)
7408 				prsm->r_one_out_nr = 1;
7409 		}
7410 		return;
7411 	}
7412 	/*
7413 	 * If we reach here its a retransmission and we need to find it.
7414 	 */
7415 	memset(&fe, 0, sizeof(fe));
7416 more:
7417 	if (hintrsm && (hintrsm->r_start == seq_out)) {
7418 		rsm = hintrsm;
7419 		hintrsm = NULL;
7420 	} else {
7421 		/* No hints sorry */
7422 		rsm = NULL;
7423 	}
7424 	if ((rsm) && (rsm->r_start == seq_out)) {
7425 		seq_out = rack_update_entry(tp, rack, rsm, cts, &len, add_flag);
7426 		if (len == 0) {
7427 			return;
7428 		} else {
7429 			goto more;
7430 		}
7431 	}
7432 	/* Ok it was not the last pointer go through it the hard way. */
7433 refind:
7434 	fe.r_start = seq_out;
7435 	rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
7436 	if (rsm) {
7437 		if (rsm->r_start == seq_out) {
7438 			seq_out = rack_update_entry(tp, rack, rsm, cts, &len, add_flag);
7439 			if (len == 0) {
7440 				return;
7441 			} else {
7442 				goto refind;
7443 			}
7444 		}
7445 		if (SEQ_GEQ(seq_out, rsm->r_start) && SEQ_LT(seq_out, rsm->r_end)) {
7446 			/* Transmitted within this piece */
7447 			/*
7448 			 * Ok we must split off the front and then let the
7449 			 * update do the rest
7450 			 */
7451 			nrsm = rack_alloc_full_limit(rack);
7452 			if (nrsm == NULL) {
7453 				rack_update_rsm(tp, rack, rsm, cts, add_flag);
7454 				return;
7455 			}
7456 			/*
7457 			 * copy rsm to nrsm and then trim the front of rsm
7458 			 * to not include this part.
7459 			 */
7460 			rack_clone_rsm(rack, nrsm, rsm, seq_out);
7461 			rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SPLIT, 0, __LINE__);
7462 #ifndef INVARIANTS
7463 			(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
7464 #else
7465 			insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
7466 			if (insret != NULL) {
7467 				panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
7468 				      nrsm, insret, rack, rsm);
7469 			}
7470 #endif
7471 			if (rsm->r_in_tmap) {
7472 				TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7473 				nrsm->r_in_tmap = 1;
7474 			}
7475 			rsm->r_flags &= (~RACK_HAS_FIN);
7476 			seq_out = rack_update_entry(tp, rack, nrsm, cts, &len, add_flag);
7477 			if (len == 0) {
7478 				return;
7479 			} else if (len > 0)
7480 				goto refind;
7481 		}
7482 	}
7483 	/*
7484 	 * Hmm not found in map did they retransmit both old and on into the
7485 	 * new?
7486 	 */
7487 	if (seq_out == tp->snd_max) {
7488 		goto again;
7489 	} else if (SEQ_LT(seq_out, tp->snd_max)) {
7490 #ifdef INVARIANTS
7491 		printf("seq_out:%u len:%d snd_una:%u snd_max:%u -- but rsm not found?\n",
7492 		       seq_out, len, tp->snd_una, tp->snd_max);
7493 		printf("Starting Dump of all rack entries\n");
7494 		RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
7495 			printf("rsm:%p start:%u end:%u\n",
7496 			       rsm, rsm->r_start, rsm->r_end);
7497 		}
7498 		printf("Dump complete\n");
7499 		panic("seq_out not found rack:%p tp:%p",
7500 		      rack, tp);
7501 #endif
7502 	} else {
7503 #ifdef INVARIANTS
7504 		/*
7505 		 * Hmm beyond sndmax? (only if we are using the new rtt-pack
7506 		 * flag)
7507 		 */
7508 		panic("seq_out:%u(%d) is beyond snd_max:%u tp:%p",
7509 		      seq_out, len, tp->snd_max, tp);
7510 #endif
7511 	}
7512 }
7513 
7514 /*
7515  * Record one of the RTT updates from an ack into
7516  * our sample structure.
7517  */
7518 
7519 static void
7520 tcp_rack_xmit_timer(struct tcp_rack *rack, int32_t rtt, uint32_t len, uint32_t us_rtt,
7521 		    int confidence, struct rack_sendmap *rsm, uint16_t rtrcnt)
7522 {
7523 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
7524 	    (rack->r_ctl.rack_rs.rs_rtt_lowest > rtt)) {
7525 		rack->r_ctl.rack_rs.rs_rtt_lowest = rtt;
7526 	}
7527 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
7528 	    (rack->r_ctl.rack_rs.rs_rtt_highest < rtt)) {
7529 		rack->r_ctl.rack_rs.rs_rtt_highest = rtt;
7530 	}
7531 	if (rack->rc_tp->t_flags & TF_GPUTINPROG) {
7532 	    if (us_rtt < rack->r_ctl.rc_gp_lowrtt)
7533 		rack->r_ctl.rc_gp_lowrtt = us_rtt;
7534 	    if (rack->rc_tp->snd_wnd > rack->r_ctl.rc_gp_high_rwnd)
7535 		    rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
7536 	}
7537 	if ((confidence == 1) &&
7538 	    ((rsm == NULL) ||
7539 	     (rsm->r_just_ret) ||
7540 	     (rsm->r_one_out_nr &&
7541 	      len < (ctf_fixed_maxseg(rack->rc_tp) * 2)))) {
7542 		/*
7543 		 * If the rsm had a just return
7544 		 * hit it then we can't trust the
7545 		 * rtt measurement for buffer deterimination
7546 		 * Note that a confidence of 2, indicates
7547 		 * SACK'd which overrides the r_just_ret or
7548 		 * the r_one_out_nr. If it was a CUM-ACK and
7549 		 * we had only two outstanding, but get an
7550 		 * ack for only 1. Then that also lowers our
7551 		 * confidence.
7552 		 */
7553 		confidence = 0;
7554 	}
7555 	if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY) ||
7556 	    (rack->r_ctl.rack_rs.rs_us_rtt > us_rtt)) {
7557 		if (rack->r_ctl.rack_rs.confidence == 0) {
7558 			/*
7559 			 * We take anything with no current confidence
7560 			 * saved.
7561 			 */
7562 			rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
7563 			rack->r_ctl.rack_rs.confidence = confidence;
7564 			rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
7565 		} else if (confidence || rack->r_ctl.rack_rs.confidence) {
7566 			/*
7567 			 * Once we have a confident number,
7568 			 * we can update it with a smaller
7569 			 * value since this confident number
7570 			 * may include the DSACK time until
7571 			 * the next segment (the second one) arrived.
7572 			 */
7573 			rack->r_ctl.rack_rs.rs_us_rtt = us_rtt;
7574 			rack->r_ctl.rack_rs.confidence = confidence;
7575 			rack->r_ctl.rack_rs.rs_us_rtrcnt = rtrcnt;
7576 		}
7577 	}
7578 	rack_log_rtt_upd(rack->rc_tp, rack, us_rtt, len, rsm, confidence);
7579 	rack->r_ctl.rack_rs.rs_flags = RACK_RTT_VALID;
7580 	rack->r_ctl.rack_rs.rs_rtt_tot += rtt;
7581 	rack->r_ctl.rack_rs.rs_rtt_cnt++;
7582 }
7583 
7584 /*
7585  * Collect new round-trip time estimate
7586  * and update averages and current timeout.
7587  */
7588 static void
7589 tcp_rack_xmit_timer_commit(struct tcp_rack *rack, struct tcpcb *tp)
7590 {
7591 	int32_t delta;
7592 	int32_t rtt;
7593 
7594 	if (rack->r_ctl.rack_rs.rs_flags & RACK_RTT_EMPTY)
7595 		/* No valid sample */
7596 		return;
7597 	if (rack->r_ctl.rc_rate_sample_method == USE_RTT_LOW) {
7598 		/* We are to use the lowest RTT seen in a single ack */
7599 		rtt = rack->r_ctl.rack_rs.rs_rtt_lowest;
7600 	} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_HIGH) {
7601 		/* We are to use the highest RTT seen in a single ack */
7602 		rtt = rack->r_ctl.rack_rs.rs_rtt_highest;
7603 	} else if (rack->r_ctl.rc_rate_sample_method == USE_RTT_AVG) {
7604 		/* We are to use the average RTT seen in a single ack */
7605 		rtt = (int32_t)(rack->r_ctl.rack_rs.rs_rtt_tot /
7606 				(uint64_t)rack->r_ctl.rack_rs.rs_rtt_cnt);
7607 	} else {
7608 #ifdef INVARIANTS
7609 		panic("Unknown rtt variant %d", rack->r_ctl.rc_rate_sample_method);
7610 #endif
7611 		return;
7612 	}
7613 	if (rtt == 0)
7614 		rtt = 1;
7615 	if (rack->rc_gp_rtt_set == 0) {
7616 		/*
7617 		 * With no RTT we have to accept
7618 		 * even one we are not confident of.
7619 		 */
7620 		rack->r_ctl.rc_gp_srtt = rack->r_ctl.rack_rs.rs_us_rtt;
7621 		rack->rc_gp_rtt_set = 1;
7622 	} else if (rack->r_ctl.rack_rs.confidence) {
7623 		/* update the running gp srtt */
7624 		rack->r_ctl.rc_gp_srtt -= (rack->r_ctl.rc_gp_srtt/8);
7625 		rack->r_ctl.rc_gp_srtt += rack->r_ctl.rack_rs.rs_us_rtt / 8;
7626 	}
7627 	if (rack->r_ctl.rack_rs.confidence) {
7628 		/*
7629 		 * record the low and high for highly buffered path computation,
7630 		 * we only do this if we are confident (not a retransmission).
7631 		 */
7632 		if (rack->r_ctl.rc_highest_us_rtt < rack->r_ctl.rack_rs.rs_us_rtt) {
7633 			rack->r_ctl.rc_highest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
7634 		}
7635 		if (rack->rc_highly_buffered == 0) {
7636 			/*
7637 			 * Currently once we declare a path has
7638 			 * highly buffered there is no going
7639 			 * back, which may be a problem...
7640 			 */
7641 			if ((rack->r_ctl.rc_highest_us_rtt / rack->r_ctl.rc_lowest_us_rtt) > rack_hbp_thresh) {
7642 				rack_log_rtt_shrinks(rack, rack->r_ctl.rack_rs.rs_us_rtt,
7643 						     rack->r_ctl.rc_highest_us_rtt,
7644 						     rack->r_ctl.rc_lowest_us_rtt,
7645 						     RACK_RTTS_SEEHBP);
7646 				rack->rc_highly_buffered = 1;
7647 			}
7648 		}
7649 	}
7650 	if ((rack->r_ctl.rack_rs.confidence) ||
7651 	    (rack->r_ctl.rack_rs.rs_us_rtrcnt == 1)) {
7652 		/*
7653 		 * If we are highly confident of it <or> it was
7654 		 * never retransmitted we accept it as the last us_rtt.
7655 		 */
7656 		rack->r_ctl.rc_last_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
7657 		/* The lowest rtt can be set if its was not retransmited */
7658 		if (rack->r_ctl.rc_lowest_us_rtt > rack->r_ctl.rack_rs.rs_us_rtt) {
7659 			rack->r_ctl.rc_lowest_us_rtt = rack->r_ctl.rack_rs.rs_us_rtt;
7660 			if (rack->r_ctl.rc_lowest_us_rtt == 0)
7661 				rack->r_ctl.rc_lowest_us_rtt = 1;
7662 		}
7663 	}
7664 	rack = (struct tcp_rack *)tp->t_fb_ptr;
7665 	if (tp->t_srtt != 0) {
7666 		/*
7667 		 * We keep a simple srtt in microseconds, like our rtt
7668 		 * measurement. We don't need to do any tricks with shifting
7669 		 * etc. Instead we just add in 1/8th of the new measurement
7670 		 * and subtract out 1/8 of the old srtt. We do the same with
7671 		 * the variance after finding the absolute value of the
7672 		 * difference between this sample and the current srtt.
7673 		 */
7674 		delta = tp->t_srtt - rtt;
7675 		/* Take off 1/8th of the current sRTT */
7676 		tp->t_srtt -= (tp->t_srtt >> 3);
7677 		/* Add in 1/8th of the new RTT just measured */
7678 		tp->t_srtt += (rtt >> 3);
7679 		if (tp->t_srtt <= 0)
7680 			tp->t_srtt = 1;
7681 		/* Now lets make the absolute value of the variance */
7682 		if (delta < 0)
7683 			delta = -delta;
7684 		/* Subtract out 1/8th */
7685 		tp->t_rttvar -= (tp->t_rttvar >> 3);
7686 		/* Add in 1/8th of the new variance we just saw */
7687 		tp->t_rttvar += (delta >> 3);
7688 		if (tp->t_rttvar <= 0)
7689 			tp->t_rttvar = 1;
7690 		if (tp->t_rttbest > tp->t_srtt + tp->t_rttvar)
7691 			tp->t_rttbest = tp->t_srtt + tp->t_rttvar;
7692 	} else {
7693 		/*
7694 		 * No rtt measurement yet - use the unsmoothed rtt. Set the
7695 		 * variance to half the rtt (so our first retransmit happens
7696 		 * at 3*rtt).
7697 		 */
7698 		tp->t_srtt = rtt;
7699 		tp->t_rttvar = rtt >> 1;
7700 		tp->t_rttbest = tp->t_srtt + tp->t_rttvar;
7701 	}
7702 	rack->rc_srtt_measure_made = 1;
7703 	KMOD_TCPSTAT_INC(tcps_rttupdated);
7704 	tp->t_rttupdated++;
7705 #ifdef STATS
7706 	if (rack_stats_gets_ms_rtt == 0) {
7707 		/* Send in the microsecond rtt used for rxt timeout purposes */
7708 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rtt));
7709 	} else if (rack_stats_gets_ms_rtt == 1) {
7710 		/* Send in the millisecond rtt used for rxt timeout purposes */
7711 		int32_t ms_rtt;
7712 
7713 		/* Round up */
7714 		ms_rtt = (rtt + HPTS_USEC_IN_MSEC - 1) / HPTS_USEC_IN_MSEC;
7715 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, ms_rtt));
7716 	} else if (rack_stats_gets_ms_rtt == 2) {
7717 		/* Send in the millisecond rtt has close to the path RTT as we can get  */
7718 		int32_t ms_rtt;
7719 
7720 		/* Round up */
7721 		ms_rtt = (rack->r_ctl.rack_rs.rs_us_rtt + HPTS_USEC_IN_MSEC - 1) / HPTS_USEC_IN_MSEC;
7722 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, ms_rtt));
7723 	}  else {
7724 		/* Send in the microsecond rtt has close to the path RTT as we can get  */
7725 		stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rack->r_ctl.rack_rs.rs_us_rtt));
7726 	}
7727 
7728 #endif
7729 	/*
7730 	 * the retransmit should happen at rtt + 4 * rttvar. Because of the
7731 	 * way we do the smoothing, srtt and rttvar will each average +1/2
7732 	 * tick of bias.  When we compute the retransmit timer, we want 1/2
7733 	 * tick of rounding and 1 extra tick because of +-1/2 tick
7734 	 * uncertainty in the firing of the timer.  The bias will give us
7735 	 * exactly the 1.5 tick we need.  But, because the bias is
7736 	 * statistical, we have to test that we don't drop below the minimum
7737 	 * feasible timer (which is 2 ticks).
7738 	 */
7739 	tp->t_rxtshift = 0;
7740 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
7741 		      max(rack_rto_min, rtt + 2), rack_rto_max, rack->r_ctl.timer_slop);
7742 	rack_log_rtt_sample(rack, rtt);
7743 	tp->t_softerror = 0;
7744 }
7745 
7746 
7747 static void
7748 rack_apply_updated_usrtt(struct tcp_rack *rack, uint32_t us_rtt, uint32_t us_cts)
7749 {
7750 	/*
7751 	 * Apply to filter the inbound us-rtt at us_cts.
7752 	 */
7753 	uint32_t old_rtt;
7754 
7755 	old_rtt = get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt);
7756 	apply_filter_min_small(&rack->r_ctl.rc_gp_min_rtt,
7757 			       us_rtt, us_cts);
7758 	if (old_rtt > us_rtt) {
7759 		/* We just hit a new lower rtt time */
7760 		rack_log_rtt_shrinks(rack,  us_cts,  old_rtt,
7761 				     __LINE__, RACK_RTTS_NEWRTT);
7762 		/*
7763 		 * Only count it if its lower than what we saw within our
7764 		 * calculated range.
7765 		 */
7766 		if ((old_rtt - us_rtt) > rack_min_rtt_movement) {
7767 			if (rack_probertt_lower_within &&
7768 			    rack->rc_gp_dyn_mul &&
7769 			    (rack->use_fixed_rate == 0) &&
7770 			    (rack->rc_always_pace)) {
7771 				/*
7772 				 * We are seeing a new lower rtt very close
7773 				 * to the time that we would have entered probe-rtt.
7774 				 * This is probably due to the fact that a peer flow
7775 				 * has entered probe-rtt. Lets go in now too.
7776 				 */
7777 				uint32_t val;
7778 
7779 				val = rack_probertt_lower_within * rack_time_between_probertt;
7780 				val /= 100;
7781 				if ((rack->in_probe_rtt == 0)  &&
7782 				    ((us_cts - rack->r_ctl.rc_lower_rtt_us_cts) >= (rack_time_between_probertt - val)))	{
7783 					rack_enter_probertt(rack, us_cts);
7784 				}
7785 			}
7786 			rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
7787 		}
7788 	}
7789 }
7790 
7791 static int
7792 rack_update_rtt(struct tcpcb *tp, struct tcp_rack *rack,
7793     struct rack_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, tcp_seq th_ack)
7794 {
7795 	uint32_t us_rtt;
7796 	int32_t i, all;
7797 	uint32_t t, len_acked;
7798 
7799 	if ((rsm->r_flags & RACK_ACKED) ||
7800 	    (rsm->r_flags & RACK_WAS_ACKED))
7801 		/* Already done */
7802 		return (0);
7803 	if (rsm->r_no_rtt_allowed) {
7804 		/* Not allowed */
7805 		return (0);
7806 	}
7807 	if (ack_type == CUM_ACKED) {
7808 		if (SEQ_GT(th_ack, rsm->r_end)) {
7809 			len_acked = rsm->r_end - rsm->r_start;
7810 			all = 1;
7811 		} else {
7812 			len_acked = th_ack - rsm->r_start;
7813 			all = 0;
7814 		}
7815 	} else {
7816 		len_acked = rsm->r_end - rsm->r_start;
7817 		all = 0;
7818 	}
7819 	if (rsm->r_rtr_cnt == 1) {
7820 
7821 		t = cts - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
7822 		if ((int)t <= 0)
7823 			t = 1;
7824 		if (!tp->t_rttlow || tp->t_rttlow > t)
7825 			tp->t_rttlow = t;
7826 		if (!rack->r_ctl.rc_rack_min_rtt ||
7827 		    SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
7828 			rack->r_ctl.rc_rack_min_rtt = t;
7829 			if (rack->r_ctl.rc_rack_min_rtt == 0) {
7830 				rack->r_ctl.rc_rack_min_rtt = 1;
7831 			}
7832 		}
7833 		if (TSTMP_GT(tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time), rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]))
7834 			us_rtt = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
7835 		else
7836 			us_rtt = tcp_get_usecs(NULL) - (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
7837 		if (us_rtt == 0)
7838 			us_rtt = 1;
7839 		if (CC_ALGO(tp)->rttsample != NULL) {
7840 			/* Kick the RTT to the CC */
7841 			CC_ALGO(tp)->rttsample(tp->ccv, us_rtt, 1, rsm->r_fas);
7842 		}
7843 		rack_apply_updated_usrtt(rack, us_rtt, tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time));
7844 		if (ack_type == SACKED) {
7845 			rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)], cts, 1);
7846 			tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt, 2 , rsm, rsm->r_rtr_cnt);
7847 		} else {
7848 			/*
7849 			 * We need to setup what our confidence
7850 			 * is in this ack.
7851 			 *
7852 			 * If the rsm was app limited and it is
7853 			 * less than a mss in length (the end
7854 			 * of the send) then we have a gap. If we
7855 			 * were app limited but say we were sending
7856 			 * multiple MSS's then we are more confident
7857 			 * int it.
7858 			 *
7859 			 * When we are not app-limited then we see if
7860 			 * the rsm is being included in the current
7861 			 * measurement, we tell this by the app_limited_needs_set
7862 			 * flag.
7863 			 *
7864 			 * Note that being cwnd blocked is not applimited
7865 			 * as well as the pacing delay between packets which
7866 			 * are sending only 1 or 2 MSS's also will show up
7867 			 * in the RTT. We probably need to examine this algorithm
7868 			 * a bit more and enhance it to account for the delay
7869 			 * between rsm's. We could do that by saving off the
7870 			 * pacing delay of each rsm (in an rsm) and then
7871 			 * factoring that in somehow though for now I am
7872 			 * not sure how :)
7873 			 */
7874 			int calc_conf = 0;
7875 
7876 			if (rsm->r_flags & RACK_APP_LIMITED) {
7877 				if (all && (len_acked <= ctf_fixed_maxseg(tp)))
7878 					calc_conf = 0;
7879 				else
7880 					calc_conf = 1;
7881 			} else if (rack->app_limited_needs_set == 0) {
7882 				calc_conf = 1;
7883 			} else {
7884 				calc_conf = 0;
7885 			}
7886 			rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)], cts, 2);
7887 			tcp_rack_xmit_timer(rack, t + 1, len_acked, us_rtt,
7888 					    calc_conf, rsm, rsm->r_rtr_cnt);
7889 		}
7890 		if ((rsm->r_flags & RACK_TLP) &&
7891 		    (!IN_FASTRECOVERY(tp->t_flags))) {
7892 			/* Segment was a TLP and our retrans matched */
7893 			if (rack->r_ctl.rc_tlp_cwnd_reduce) {
7894 				rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
7895 			}
7896 		}
7897 		if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)])) {
7898 			/* New more recent rack_tmit_time */
7899 			rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
7900 			rack->rc_rack_rtt = t;
7901 		}
7902 		return (1);
7903 	}
7904 	/*
7905 	 * We clear the soft/rxtshift since we got an ack.
7906 	 * There is no assurance we will call the commit() function
7907 	 * so we need to clear these to avoid incorrect handling.
7908 	 */
7909 	tp->t_rxtshift = 0;
7910 	RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
7911 		      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
7912 	tp->t_softerror = 0;
7913 	if (to && (to->to_flags & TOF_TS) &&
7914 	    (ack_type == CUM_ACKED) &&
7915 	    (to->to_tsecr) &&
7916 	    ((rsm->r_flags & RACK_OVERMAX) == 0)) {
7917 		/*
7918 		 * Now which timestamp does it match? In this block the ACK
7919 		 * must be coming from a previous transmission.
7920 		 */
7921 		for (i = 0; i < rsm->r_rtr_cnt; i++) {
7922 			if (rack_ts_to_msec(rsm->r_tim_lastsent[i]) == to->to_tsecr) {
7923 				t = cts - (uint32_t)rsm->r_tim_lastsent[i];
7924 				if ((int)t <= 0)
7925 					t = 1;
7926 				if (CC_ALGO(tp)->rttsample != NULL) {
7927 					/*
7928 					 * Kick the RTT to the CC, here
7929 					 * we lie a bit in that we know the
7930 					 * retransmission is correct even though
7931 					 * we retransmitted. This is because
7932 					 * we match the timestamps.
7933 					 */
7934 					if (TSTMP_GT(tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time), rsm->r_tim_lastsent[i]))
7935 						us_rtt = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time) - (uint32_t)rsm->r_tim_lastsent[i];
7936 					else
7937 						us_rtt = tcp_get_usecs(NULL) - (uint32_t)rsm->r_tim_lastsent[i];
7938 					CC_ALGO(tp)->rttsample(tp->ccv, us_rtt, 1, rsm->r_fas);
7939 				}
7940 				if ((i + 1) < rsm->r_rtr_cnt) {
7941 					/*
7942 					 * The peer ack'd from our previous
7943 					 * transmission. We have a spurious
7944 					 * retransmission and thus we dont
7945 					 * want to update our rack_rtt.
7946 					 *
7947 					 * Hmm should there be a CC revert here?
7948 					 *
7949 					 */
7950 					return (0);
7951 				}
7952 				if (!tp->t_rttlow || tp->t_rttlow > t)
7953 					tp->t_rttlow = t;
7954 				if (!rack->r_ctl.rc_rack_min_rtt || SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
7955 					rack->r_ctl.rc_rack_min_rtt = t;
7956 					if (rack->r_ctl.rc_rack_min_rtt == 0) {
7957 						rack->r_ctl.rc_rack_min_rtt = 1;
7958 					}
7959 				}
7960 				if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time,
7961 					   (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)])) {
7962 					/* New more recent rack_tmit_time */
7963 					rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
7964 					rack->rc_rack_rtt = t;
7965 				}
7966 				rack_log_rtt_sample_calc(rack, t, (uint32_t)rsm->r_tim_lastsent[i], cts, 3);
7967 				tcp_rack_xmit_timer(rack, t + 1, len_acked, t, 0, rsm,
7968 						    rsm->r_rtr_cnt);
7969 				return (1);
7970 			}
7971 		}
7972 		goto ts_not_found;
7973 	} else {
7974 		/*
7975 		 * Ok its a SACK block that we retransmitted. or a windows
7976 		 * machine without timestamps. We can tell nothing from the
7977 		 * time-stamp since its not there or the time the peer last
7978 		 * recieved a segment that moved forward its cum-ack point.
7979 		 */
7980 ts_not_found:
7981 		i = rsm->r_rtr_cnt - 1;
7982 		t = cts - (uint32_t)rsm->r_tim_lastsent[i];
7983 		if ((int)t <= 0)
7984 			t = 1;
7985 		if (rack->r_ctl.rc_rack_min_rtt && SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
7986 			/*
7987 			 * We retransmitted and the ack came back in less
7988 			 * than the smallest rtt we have observed. We most
7989 			 * likely did an improper retransmit as outlined in
7990 			 * 6.2 Step 2 point 2 in the rack-draft so we
7991 			 * don't want to update our rack_rtt. We in
7992 			 * theory (in future) might want to think about reverting our
7993 			 * cwnd state but we won't for now.
7994 			 */
7995 			return (0);
7996 		} else if (rack->r_ctl.rc_rack_min_rtt) {
7997 			/*
7998 			 * We retransmitted it and the retransmit did the
7999 			 * job.
8000 			 */
8001 			if (!rack->r_ctl.rc_rack_min_rtt ||
8002 			    SEQ_LT(t, rack->r_ctl.rc_rack_min_rtt)) {
8003 				rack->r_ctl.rc_rack_min_rtt = t;
8004 				if (rack->r_ctl.rc_rack_min_rtt == 0) {
8005 					rack->r_ctl.rc_rack_min_rtt = 1;
8006 				}
8007 			}
8008 			if (SEQ_LT(rack->r_ctl.rc_rack_tmit_time, (uint32_t)rsm->r_tim_lastsent[i])) {
8009 				/* New more recent rack_tmit_time */
8010 				rack->r_ctl.rc_rack_tmit_time = (uint32_t)rsm->r_tim_lastsent[i];
8011 				rack->rc_rack_rtt = t;
8012 			}
8013 			return (1);
8014 		}
8015 	}
8016 	return (0);
8017 }
8018 
8019 /*
8020  * Mark the SACK_PASSED flag on all entries prior to rsm send wise.
8021  */
8022 static void
8023 rack_log_sack_passed(struct tcpcb *tp,
8024     struct tcp_rack *rack, struct rack_sendmap *rsm)
8025 {
8026 	struct rack_sendmap *nrsm;
8027 
8028 	nrsm = rsm;
8029 	TAILQ_FOREACH_REVERSE_FROM(nrsm, &rack->r_ctl.rc_tmap,
8030 	    rack_head, r_tnext) {
8031 		if (nrsm == rsm) {
8032 			/* Skip orginal segment he is acked */
8033 			continue;
8034 		}
8035 		if (nrsm->r_flags & RACK_ACKED) {
8036 			/*
8037 			 * Skip ack'd segments, though we
8038 			 * should not see these, since tmap
8039 			 * should not have ack'd segments.
8040 			 */
8041 			continue;
8042 		}
8043 		if (nrsm->r_flags & RACK_SACK_PASSED) {
8044 			/*
8045 			 * We found one that is already marked
8046 			 * passed, we have been here before and
8047 			 * so all others below this are marked.
8048 			 */
8049 			break;
8050 		}
8051 		nrsm->r_flags |= RACK_SACK_PASSED;
8052 		nrsm->r_flags &= ~RACK_WAS_SACKPASS;
8053 	}
8054 }
8055 
8056 static void
8057 rack_need_set_test(struct tcpcb *tp,
8058 		   struct tcp_rack *rack,
8059 		   struct rack_sendmap *rsm,
8060 		   tcp_seq th_ack,
8061 		   int line,
8062 		   int use_which)
8063 {
8064 
8065 	if ((tp->t_flags & TF_GPUTINPROG) &&
8066 	    SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
8067 		/*
8068 		 * We were app limited, and this ack
8069 		 * butts up or goes beyond the point where we want
8070 		 * to start our next measurement. We need
8071 		 * to record the new gput_ts as here and
8072 		 * possibly update the start sequence.
8073 		 */
8074 		uint32_t seq, ts;
8075 
8076 		if (rsm->r_rtr_cnt > 1) {
8077 			/*
8078 			 * This is a retransmit, can we
8079 			 * really make any assessment at this
8080 			 * point?  We are not really sure of
8081 			 * the timestamp, is it this or the
8082 			 * previous transmission?
8083 			 *
8084 			 * Lets wait for something better that
8085 			 * is not retransmitted.
8086 			 */
8087 			return;
8088 		}
8089 		seq = tp->gput_seq;
8090 		ts = tp->gput_ts;
8091 		rack->app_limited_needs_set = 0;
8092 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
8093 		/* Do we start at a new end? */
8094 		if ((use_which == RACK_USE_BEG) &&
8095 		    SEQ_GEQ(rsm->r_start, tp->gput_seq)) {
8096 			/*
8097 			 * When we get an ACK that just eats
8098 			 * up some of the rsm, we set RACK_USE_BEG
8099 			 * since whats at r_start (i.e. th_ack)
8100 			 * is left unacked and thats where the
8101 			 * measurement not starts.
8102 			 */
8103 			tp->gput_seq = rsm->r_start;
8104 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8105 		}
8106 		if ((use_which == RACK_USE_END) &&
8107 		    SEQ_GEQ(rsm->r_end, tp->gput_seq)) {
8108 			    /*
8109 			     * We use the end when the cumack
8110 			     * is moving forward and completely
8111 			     * deleting the rsm passed so basically
8112 			     * r_end holds th_ack.
8113 			     *
8114 			     * For SACK's we also want to use the end
8115 			     * since this piece just got sacked and
8116 			     * we want to target anything after that
8117 			     * in our measurement.
8118 			     */
8119 			    tp->gput_seq = rsm->r_end;
8120 			    rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8121 		}
8122 		if (use_which == RACK_USE_END_OR_THACK) {
8123 			/*
8124 			 * special case for ack moving forward,
8125 			 * not a sack, we need to move all the
8126 			 * way up to where this ack cum-ack moves
8127 			 * to.
8128 			 */
8129 			if (SEQ_GT(th_ack, rsm->r_end))
8130 				tp->gput_seq = th_ack;
8131 			else
8132 				tp->gput_seq = rsm->r_end;
8133 			rack->r_ctl.rc_gp_output_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
8134 		}
8135 		if (SEQ_GT(tp->gput_seq, tp->gput_ack)) {
8136 			/*
8137 			 * We moved beyond this guy's range, re-calculate
8138 			 * the new end point.
8139 			 */
8140 			if (rack->rc_gp_filled == 0) {
8141 				tp->gput_ack = tp->gput_seq + max(rc_init_window(rack), (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
8142 			} else {
8143 				tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
8144 			}
8145 		}
8146 		/*
8147 		 * We are moving the goal post, we may be able to clear the
8148 		 * measure_saw_probe_rtt flag.
8149 		 */
8150 		if ((rack->in_probe_rtt == 0) &&
8151 		    (rack->measure_saw_probe_rtt) &&
8152 		    (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
8153 			rack->measure_saw_probe_rtt = 0;
8154 		rack_log_pacing_delay_calc(rack, ts, tp->gput_ts,
8155 					   seq, tp->gput_seq, 0, 5, line, NULL, 0);
8156 		if (rack->rc_gp_filled &&
8157 		    ((tp->gput_ack - tp->gput_seq) <
8158 		     max(rc_init_window(rack), (MIN_GP_WIN *
8159 						ctf_fixed_maxseg(tp))))) {
8160 			uint32_t ideal_amount;
8161 
8162 			ideal_amount = rack_get_measure_window(tp, rack);
8163 			if (ideal_amount > sbavail(&tp->t_inpcb->inp_socket->so_snd)) {
8164 				/*
8165 				 * There is no sense of continuing this measurement
8166 				 * because its too small to gain us anything we
8167 				 * trust. Skip it and that way we can start a new
8168 				 * measurement quicker.
8169 				 */
8170 				tp->t_flags &= ~TF_GPUTINPROG;
8171 				rack_log_pacing_delay_calc(rack, tp->gput_ack, tp->gput_seq,
8172 							   0, 0, 0, 6, __LINE__, NULL, 0);
8173 			} else {
8174 				/*
8175 				 * Reset the window further out.
8176 				 */
8177 				tp->gput_ack = tp->gput_seq + ideal_amount;
8178 			}
8179 		}
8180 	}
8181 }
8182 
8183 static inline int
8184 is_rsm_inside_declared_tlp_block(struct tcp_rack *rack, struct rack_sendmap *rsm)
8185 {
8186 	if (SEQ_LT(rsm->r_end, rack->r_ctl.last_tlp_acked_start)) {
8187 		/* Behind our TLP definition or right at */
8188 		return (0);
8189 	}
8190 	if (SEQ_GT(rsm->r_start, rack->r_ctl.last_tlp_acked_end)) {
8191 		/* The start is beyond or right at our end of TLP definition */
8192 		return (0);
8193 	}
8194 	/* It has to be a sub-part of the original TLP recorded */
8195 	return (1);
8196 }
8197 
8198 
8199 static uint32_t
8200 rack_proc_sack_blk(struct tcpcb *tp, struct tcp_rack *rack, struct sackblk *sack,
8201 		   struct tcpopt *to, struct rack_sendmap **prsm, uint32_t cts, int *moved_two)
8202 {
8203 	uint32_t start, end, changed = 0;
8204 	struct rack_sendmap stack_map;
8205 	struct rack_sendmap *rsm, *nrsm, fe, *prev, *next;
8206 #ifdef INVARIANTS
8207 	struct rack_sendmap *insret;
8208 #endif
8209 	int32_t used_ref = 1;
8210 	int moved = 0;
8211 
8212 	start = sack->start;
8213 	end = sack->end;
8214 	rsm = *prsm;
8215 	memset(&fe, 0, sizeof(fe));
8216 do_rest_ofb:
8217 	if ((rsm == NULL) ||
8218 	    (SEQ_LT(end, rsm->r_start)) ||
8219 	    (SEQ_GEQ(start, rsm->r_end)) ||
8220 	    (SEQ_LT(start, rsm->r_start))) {
8221 		/*
8222 		 * We are not in the right spot,
8223 		 * find the correct spot in the tree.
8224 		 */
8225 		used_ref = 0;
8226 		fe.r_start = start;
8227 		rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
8228 		moved++;
8229 	}
8230 	if (rsm == NULL) {
8231 		/* TSNH */
8232 		goto out;
8233 	}
8234 	/* Ok we have an ACK for some piece of this rsm */
8235 	if (rsm->r_start != start) {
8236 		if ((rsm->r_flags & RACK_ACKED) == 0) {
8237 			/*
8238 			 * Before any splitting or hookery is
8239 			 * done is it a TLP of interest i.e. rxt?
8240 			 */
8241 			if ((rsm->r_flags & RACK_TLP) &&
8242 			    (rsm->r_rtr_cnt > 1)) {
8243 				/*
8244 				 * We are splitting a rxt TLP, check
8245 				 * if we need to save off the start/end
8246 				 */
8247 				if (rack->rc_last_tlp_acked_set &&
8248 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8249 					/*
8250 					 * We already turned this on since we are inside
8251 					 * the previous one was a partially sack now we
8252 					 * are getting another one (maybe all of it).
8253 					 *
8254 					 */
8255 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8256 					/*
8257 					 * Lets make sure we have all of it though.
8258 					 */
8259 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8260 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8261 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8262 								     rack->r_ctl.last_tlp_acked_end);
8263 					}
8264 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8265 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8266 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8267 								     rack->r_ctl.last_tlp_acked_end);
8268 					}
8269 				} else {
8270 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8271 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8272 					rack->rc_last_tlp_past_cumack = 0;
8273 					rack->rc_last_tlp_acked_set = 1;
8274 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
8275 				}
8276 			}
8277 			/**
8278 			 * Need to split this in two pieces the before and after,
8279 			 * the before remains in the map, the after must be
8280 			 * added. In other words we have:
8281 			 * rsm        |--------------|
8282 			 * sackblk        |------->
8283 			 * rsm will become
8284 			 *     rsm    |---|
8285 			 * and nrsm will be  the sacked piece
8286 			 *     nrsm       |----------|
8287 			 *
8288 			 * But before we start down that path lets
8289 			 * see if the sack spans over on top of
8290 			 * the next guy and it is already sacked.
8291 			 *
8292 			 */
8293 			next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8294 			if (next && (next->r_flags & RACK_ACKED) &&
8295 			    SEQ_GEQ(end, next->r_start)) {
8296 				/**
8297 				 * So the next one is already acked, and
8298 				 * we can thus by hookery use our stack_map
8299 				 * to reflect the piece being sacked and
8300 				 * then adjust the two tree entries moving
8301 				 * the start and ends around. So we start like:
8302 				 *  rsm     |------------|             (not-acked)
8303 				 *  next                 |-----------| (acked)
8304 				 *  sackblk        |-------->
8305 				 *  We want to end like so:
8306 				 *  rsm     |------|                   (not-acked)
8307 				 *  next           |-----------------| (acked)
8308 				 *  nrsm           |-----|
8309 				 * Where nrsm is a temporary stack piece we
8310 				 * use to update all the gizmos.
8311 				 */
8312 				/* Copy up our fudge block */
8313 				nrsm = &stack_map;
8314 				memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
8315 				/* Now adjust our tree blocks */
8316 				rsm->r_end = start;
8317 				next->r_start = start;
8318 				/* Now we must adjust back where next->m is */
8319 				rack_setup_offset_for_rsm(rsm, next);
8320 
8321 				/* We don't need to adjust rsm, it did not change */
8322 				/* Clear out the dup ack count of the remainder */
8323 				rsm->r_dupack = 0;
8324 				rsm->r_just_ret = 0;
8325 				rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
8326 				/* Now lets make sure our fudge block is right */
8327 				nrsm->r_start = start;
8328 				/* Now lets update all the stats and such */
8329 				rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
8330 				if (rack->app_limited_needs_set)
8331 					rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
8332 				changed += (nrsm->r_end - nrsm->r_start);
8333 				rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
8334 				if (nrsm->r_flags & RACK_SACK_PASSED) {
8335 					rack->r_ctl.rc_reorder_ts = cts;
8336 				}
8337 				/*
8338 				 * Now we want to go up from rsm (the
8339 				 * one left un-acked) to the next one
8340 				 * in the tmap. We do this so when
8341 				 * we walk backwards we include marking
8342 				 * sack-passed on rsm (The one passed in
8343 				 * is skipped since it is generally called
8344 				 * on something sacked before removing it
8345 				 * from the tmap).
8346 				 */
8347 				if (rsm->r_in_tmap) {
8348 					nrsm = TAILQ_NEXT(rsm, r_tnext);
8349 					/*
8350 					 * Now that we have the next
8351 					 * one walk backwards from there.
8352 					 */
8353 					if (nrsm && nrsm->r_in_tmap)
8354 						rack_log_sack_passed(tp, rack, nrsm);
8355 				}
8356 				/* Now are we done? */
8357 				if (SEQ_LT(end, next->r_end) ||
8358 				    (end == next->r_end)) {
8359 					/* Done with block */
8360 					goto out;
8361 				}
8362 				rack_log_map_chg(tp, rack, &stack_map, rsm, next, MAP_SACK_M1, end, __LINE__);
8363 				counter_u64_add(rack_sack_used_next_merge, 1);
8364 				/* Postion for the next block */
8365 				start = next->r_end;
8366 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, next);
8367 				if (rsm == NULL)
8368 					goto out;
8369 			} else {
8370 				/**
8371 				 * We can't use any hookery here, so we
8372 				 * need to split the map. We enter like
8373 				 * so:
8374 				 *  rsm      |--------|
8375 				 *  sackblk       |----->
8376 				 * We will add the new block nrsm and
8377 				 * that will be the new portion, and then
8378 				 * fall through after reseting rsm. So we
8379 				 * split and look like this:
8380 				 *  rsm      |----|
8381 				 *  sackblk       |----->
8382 				 *  nrsm          |---|
8383 				 * We then fall through reseting
8384 				 * rsm to nrsm, so the next block
8385 				 * picks it up.
8386 				 */
8387 				nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
8388 				if (nrsm == NULL) {
8389 					/*
8390 					 * failed XXXrrs what can we do but loose the sack
8391 					 * info?
8392 					 */
8393 					goto out;
8394 				}
8395 				counter_u64_add(rack_sack_splits, 1);
8396 				rack_clone_rsm(rack, nrsm, rsm, start);
8397 				rsm->r_just_ret = 0;
8398 #ifndef INVARIANTS
8399 				(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
8400 #else
8401 				insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
8402 				if (insret != NULL) {
8403 					panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
8404 					      nrsm, insret, rack, rsm);
8405 				}
8406 #endif
8407 				if (rsm->r_in_tmap) {
8408 					TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8409 					nrsm->r_in_tmap = 1;
8410 				}
8411 				rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SACK_M2, end, __LINE__);
8412 				rsm->r_flags &= (~RACK_HAS_FIN);
8413 				/* Position us to point to the new nrsm that starts the sack blk */
8414 				rsm = nrsm;
8415 			}
8416 		} else {
8417 			/* Already sacked this piece */
8418 			counter_u64_add(rack_sack_skipped_acked, 1);
8419 			moved++;
8420 			if (end == rsm->r_end) {
8421 				/* Done with block */
8422 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8423 				goto out;
8424 			} else if (SEQ_LT(end, rsm->r_end)) {
8425 				/* A partial sack to a already sacked block */
8426 				moved++;
8427 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8428 				goto out;
8429 			} else {
8430 				/*
8431 				 * The end goes beyond this guy
8432 				 * reposition the start to the
8433 				 * next block.
8434 				 */
8435 				start = rsm->r_end;
8436 				rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8437 				if (rsm == NULL)
8438 					goto out;
8439 			}
8440 		}
8441 	}
8442 	if (SEQ_GEQ(end, rsm->r_end)) {
8443 		/**
8444 		 * The end of this block is either beyond this guy or right
8445 		 * at this guy. I.e.:
8446 		 *  rsm ---                 |-----|
8447 		 *  end                     |-----|
8448 		 *  <or>
8449 		 *  end                     |---------|
8450 		 */
8451 		if ((rsm->r_flags & RACK_ACKED) == 0) {
8452 			/*
8453 			 * Is it a TLP of interest?
8454 			 */
8455 			if ((rsm->r_flags & RACK_TLP) &&
8456 			    (rsm->r_rtr_cnt > 1)) {
8457 				/*
8458 				 * We are splitting a rxt TLP, check
8459 				 * if we need to save off the start/end
8460 				 */
8461 				if (rack->rc_last_tlp_acked_set &&
8462 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8463 					/*
8464 					 * We already turned this on since we are inside
8465 					 * the previous one was a partially sack now we
8466 					 * are getting another one (maybe all of it).
8467 					 */
8468 					rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8469 					/*
8470 					 * Lets make sure we have all of it though.
8471 					 */
8472 					if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8473 						rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8474 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8475 								     rack->r_ctl.last_tlp_acked_end);
8476 					}
8477 					if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8478 						rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8479 						rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8480 								     rack->r_ctl.last_tlp_acked_end);
8481 					}
8482 				} else {
8483 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8484 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8485 					rack->rc_last_tlp_past_cumack = 0;
8486 					rack->rc_last_tlp_acked_set = 1;
8487 					rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
8488 				}
8489 			}
8490 			rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
8491 			changed += (rsm->r_end - rsm->r_start);
8492 			rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
8493 			if (rsm->r_in_tmap) /* should be true */
8494 				rack_log_sack_passed(tp, rack, rsm);
8495 			/* Is Reordering occuring? */
8496 			if (rsm->r_flags & RACK_SACK_PASSED) {
8497 				rsm->r_flags &= ~RACK_SACK_PASSED;
8498 				rack->r_ctl.rc_reorder_ts = cts;
8499 			}
8500 			if (rack->app_limited_needs_set)
8501 				rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
8502 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
8503 			rsm->r_flags |= RACK_ACKED;
8504 			if (rsm->r_in_tmap) {
8505 				TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8506 				rsm->r_in_tmap = 0;
8507 			}
8508 			rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_SACK_M3, end, __LINE__);
8509 		} else {
8510 			counter_u64_add(rack_sack_skipped_acked, 1);
8511 			moved++;
8512 		}
8513 		if (end == rsm->r_end) {
8514 			/* This block only - done, setup for next */
8515 			goto out;
8516 		}
8517 		/*
8518 		 * There is more not coverend by this rsm move on
8519 		 * to the next block in the RB tree.
8520 		 */
8521 		nrsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8522 		start = rsm->r_end;
8523 		rsm = nrsm;
8524 		if (rsm == NULL)
8525 			goto out;
8526 		goto do_rest_ofb;
8527 	}
8528 	/**
8529 	 * The end of this sack block is smaller than
8530 	 * our rsm i.e.:
8531 	 *  rsm ---                 |-----|
8532 	 *  end                     |--|
8533 	 */
8534 	if ((rsm->r_flags & RACK_ACKED) == 0) {
8535 		/*
8536 		 * Is it a TLP of interest?
8537 		 */
8538 		if ((rsm->r_flags & RACK_TLP) &&
8539 		    (rsm->r_rtr_cnt > 1)) {
8540 			/*
8541 			 * We are splitting a rxt TLP, check
8542 			 * if we need to save off the start/end
8543 			 */
8544 			if (rack->rc_last_tlp_acked_set &&
8545 			    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8546 				/*
8547 				 * We already turned this on since we are inside
8548 				 * the previous one was a partially sack now we
8549 				 * are getting another one (maybe all of it).
8550 				 */
8551 				rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8552 				/*
8553 				 * Lets make sure we have all of it though.
8554 				 */
8555 				if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8556 					rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8557 					rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8558 							     rack->r_ctl.last_tlp_acked_end);
8559 				}
8560 				if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8561 					rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8562 					rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8563 							     rack->r_ctl.last_tlp_acked_end);
8564 				}
8565 			} else {
8566 				rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8567 				rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8568 				rack->rc_last_tlp_past_cumack = 0;
8569 				rack->rc_last_tlp_acked_set = 1;
8570 				rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
8571 			}
8572 		}
8573 		prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8574 		if (prev &&
8575 		    (prev->r_flags & RACK_ACKED)) {
8576 			/**
8577 			 * Goal, we want the right remainder of rsm to shrink
8578 			 * in place and span from (rsm->r_start = end) to rsm->r_end.
8579 			 * We want to expand prev to go all the way
8580 			 * to prev->r_end <- end.
8581 			 * so in the tree we have before:
8582 			 *   prev     |--------|         (acked)
8583 			 *   rsm               |-------| (non-acked)
8584 			 *   sackblk           |-|
8585 			 * We churn it so we end up with
8586 			 *   prev     |----------|       (acked)
8587 			 *   rsm                 |-----| (non-acked)
8588 			 *   nrsm              |-| (temporary)
8589 			 *
8590 			 * Note if either prev/rsm is a TLP we don't
8591 			 * do this.
8592 			 */
8593 			nrsm = &stack_map;
8594 			memcpy(nrsm, rsm, sizeof(struct rack_sendmap));
8595 			prev->r_end = end;
8596 			rsm->r_start = end;
8597 			/* Now adjust nrsm (stack copy) to be
8598 			 * the one that is the small
8599 			 * piece that was "sacked".
8600 			 */
8601 			nrsm->r_end = end;
8602 			rsm->r_dupack = 0;
8603 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
8604 			/*
8605 			 * Now that the rsm has had its start moved forward
8606 			 * lets go ahead and get its new place in the world.
8607 			 */
8608 			rack_setup_offset_for_rsm(prev, rsm);
8609 			/*
8610 			 * Now nrsm is our new little piece
8611 			 * that is acked (which was merged
8612 			 * to prev). Update the rtt and changed
8613 			 * based on that. Also check for reordering.
8614 			 */
8615 			rack_update_rtt(tp, rack, nrsm, to, cts, SACKED, 0);
8616 			if (rack->app_limited_needs_set)
8617 				rack_need_set_test(tp, rack, nrsm, tp->snd_una, __LINE__, RACK_USE_END);
8618 			changed += (nrsm->r_end - nrsm->r_start);
8619 			rack->r_ctl.rc_sacked += (nrsm->r_end - nrsm->r_start);
8620 			if (nrsm->r_flags & RACK_SACK_PASSED) {
8621 				rack->r_ctl.rc_reorder_ts = cts;
8622 			}
8623 			rack_log_map_chg(tp, rack, prev, &stack_map, rsm, MAP_SACK_M4, end, __LINE__);
8624 			rsm = prev;
8625 			counter_u64_add(rack_sack_used_prev_merge, 1);
8626 		} else {
8627 			/**
8628 			 * This is the case where our previous
8629 			 * block is not acked either, so we must
8630 			 * split the block in two.
8631 			 */
8632 			nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
8633 			if (nrsm == NULL) {
8634 				/* failed rrs what can we do but loose the sack info? */
8635 				goto out;
8636 			}
8637 			if ((rsm->r_flags & RACK_TLP) &&
8638 			    (rsm->r_rtr_cnt > 1)) {
8639 				/*
8640 				 * We are splitting a rxt TLP, check
8641 				 * if we need to save off the start/end
8642 				 */
8643 				if (rack->rc_last_tlp_acked_set &&
8644 				    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8645 					    /*
8646 					     * We already turned this on since this block is inside
8647 					     * the previous one was a partially sack now we
8648 					     * are getting another one (maybe all of it).
8649 					     */
8650 					    rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8651 					    /*
8652 					     * Lets make sure we have all of it though.
8653 					     */
8654 					    if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
8655 						    rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8656 						    rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8657 									 rack->r_ctl.last_tlp_acked_end);
8658 					    }
8659 					    if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
8660 						    rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8661 						    rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
8662 									 rack->r_ctl.last_tlp_acked_end);
8663 					    }
8664 				    } else {
8665 					    rack->r_ctl.last_tlp_acked_start = rsm->r_start;
8666 					    rack->r_ctl.last_tlp_acked_end = rsm->r_end;
8667 					    rack->rc_last_tlp_acked_set = 1;
8668 					    rack->rc_last_tlp_past_cumack = 0;
8669 					    rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
8670 				    }
8671 			}
8672 			/**
8673 			 * In this case nrsm becomes
8674 			 * nrsm->r_start = end;
8675 			 * nrsm->r_end = rsm->r_end;
8676 			 * which is un-acked.
8677 			 * <and>
8678 			 * rsm->r_end = nrsm->r_start;
8679 			 * i.e. the remaining un-acked
8680 			 * piece is left on the left
8681 			 * hand side.
8682 			 *
8683 			 * So we start like this
8684 			 * rsm      |----------| (not acked)
8685 			 * sackblk  |---|
8686 			 * build it so we have
8687 			 * rsm      |---|         (acked)
8688 			 * nrsm         |------|  (not acked)
8689 			 */
8690 			counter_u64_add(rack_sack_splits, 1);
8691 			rack_clone_rsm(rack, nrsm, rsm, end);
8692 			rsm->r_flags &= (~RACK_HAS_FIN);
8693 			rsm->r_just_ret = 0;
8694 #ifndef INVARIANTS
8695 			(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
8696 #else
8697 			insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
8698 			if (insret != NULL) {
8699 				panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
8700 				      nrsm, insret, rack, rsm);
8701 			}
8702 #endif
8703 			if (rsm->r_in_tmap) {
8704 				TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8705 				nrsm->r_in_tmap = 1;
8706 			}
8707 			nrsm->r_dupack = 0;
8708 			rack_log_retran_reason(rack, nrsm, __LINE__, 0, 2);
8709 			rack_update_rtt(tp, rack, rsm, to, cts, SACKED, 0);
8710 			changed += (rsm->r_end - rsm->r_start);
8711 			rack->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
8712 			if (rsm->r_in_tmap) /* should be true */
8713 				rack_log_sack_passed(tp, rack, rsm);
8714 			/* Is Reordering occuring? */
8715 			if (rsm->r_flags & RACK_SACK_PASSED) {
8716 				rsm->r_flags &= ~RACK_SACK_PASSED;
8717 				rack->r_ctl.rc_reorder_ts = cts;
8718 			}
8719 			if (rack->app_limited_needs_set)
8720 				rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_END);
8721 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
8722 			rsm->r_flags |= RACK_ACKED;
8723 			rack_log_map_chg(tp, rack, NULL, rsm, nrsm, MAP_SACK_M5, end, __LINE__);
8724 			if (rsm->r_in_tmap) {
8725 				TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8726 				rsm->r_in_tmap = 0;
8727 			}
8728 		}
8729 	} else if (start != end){
8730 		/*
8731 		 * The block was already acked.
8732 		 */
8733 		counter_u64_add(rack_sack_skipped_acked, 1);
8734 		moved++;
8735 	}
8736 out:
8737 	if (rsm &&
8738 	    ((rsm->r_flags & RACK_TLP) == 0) &&
8739 	    (rsm->r_flags & RACK_ACKED)) {
8740 		/*
8741 		 * Now can we merge where we worked
8742 		 * with either the previous or
8743 		 * next block?
8744 		 */
8745 		next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8746 		while (next) {
8747 			if (next->r_flags & RACK_TLP)
8748 				break;
8749 			if (next->r_flags & RACK_ACKED) {
8750 			/* yep this and next can be merged */
8751 				rsm = rack_merge_rsm(rack, rsm, next);
8752 				next = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8753 			} else
8754 				break;
8755 		}
8756 		/* Now what about the previous? */
8757 		prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8758 		while (prev) {
8759 			if (prev->r_flags & RACK_TLP)
8760 				break;
8761 			if (prev->r_flags & RACK_ACKED) {
8762 				/* yep the previous and this can be merged */
8763 				rsm = rack_merge_rsm(rack, prev, rsm);
8764 				prev = RB_PREV(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8765 			} else
8766 				break;
8767 		}
8768 	}
8769 	if (used_ref == 0) {
8770 		counter_u64_add(rack_sack_proc_all, 1);
8771 	} else {
8772 		counter_u64_add(rack_sack_proc_short, 1);
8773 	}
8774 	/* Save off the next one for quick reference. */
8775 	if (rsm)
8776 		nrsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8777 	else
8778 		nrsm = NULL;
8779 	*prsm = rack->r_ctl.rc_sacklast = nrsm;
8780 	/* Pass back the moved. */
8781 	*moved_two = moved;
8782 	return (changed);
8783 }
8784 
8785 static void inline
8786 rack_peer_reneges(struct tcp_rack *rack, struct rack_sendmap *rsm, tcp_seq th_ack)
8787 {
8788 	struct rack_sendmap *tmap;
8789 
8790 	tmap = NULL;
8791 	while (rsm && (rsm->r_flags & RACK_ACKED)) {
8792 		/* Its no longer sacked, mark it so */
8793 		rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
8794 #ifdef INVARIANTS
8795 		if (rsm->r_in_tmap) {
8796 			panic("rack:%p rsm:%p flags:0x%x in tmap?",
8797 			      rack, rsm, rsm->r_flags);
8798 		}
8799 #endif
8800 		rsm->r_flags &= ~(RACK_ACKED|RACK_SACK_PASSED|RACK_WAS_SACKPASS);
8801 		/* Rebuild it into our tmap */
8802 		if (tmap == NULL) {
8803 			TAILQ_INSERT_HEAD(&rack->r_ctl.rc_tmap, rsm, r_tnext);
8804 			tmap = rsm;
8805 		} else {
8806 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, tmap, rsm, r_tnext);
8807 			tmap = rsm;
8808 		}
8809 		tmap->r_in_tmap = 1;
8810 		rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
8811 	}
8812 	/*
8813 	 * Now lets possibly clear the sack filter so we start
8814 	 * recognizing sacks that cover this area.
8815 	 */
8816 	sack_filter_clear(&rack->r_ctl.rack_sf, th_ack);
8817 
8818 }
8819 
8820 static void
8821 rack_do_decay(struct tcp_rack *rack)
8822 {
8823 	struct timeval res;
8824 
8825 #define	timersub(tvp, uvp, vvp)						\
8826 	do {								\
8827 		(vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;		\
8828 		(vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;	\
8829 		if ((vvp)->tv_usec < 0) {				\
8830 			(vvp)->tv_sec--;				\
8831 			(vvp)->tv_usec += 1000000;			\
8832 		}							\
8833 	} while (0)
8834 
8835 	timersub(&rack->r_ctl.act_rcv_time, &rack->r_ctl.rc_last_time_decay, &res);
8836 #undef timersub
8837 
8838 	rack->r_ctl.input_pkt++;
8839 	if ((rack->rc_in_persist) ||
8840 	    (res.tv_sec >= 1) ||
8841 	    (rack->rc_tp->snd_max == rack->rc_tp->snd_una)) {
8842 		/*
8843 		 * Check for decay of non-SAD,
8844 		 * we want all SAD detection metrics to
8845 		 * decay 1/4 per second (or more) passed.
8846 		 */
8847 #ifdef NETFLIX_EXP_DETECTION
8848 		uint32_t pkt_delta;
8849 
8850 		pkt_delta = rack->r_ctl.input_pkt - rack->r_ctl.saved_input_pkt;
8851 #endif
8852 		/* Update our saved tracking values */
8853 		rack->r_ctl.saved_input_pkt = rack->r_ctl.input_pkt;
8854 		rack->r_ctl.rc_last_time_decay = rack->r_ctl.act_rcv_time;
8855 		/* Now do we escape without decay? */
8856 #ifdef NETFLIX_EXP_DETECTION
8857 		if (rack->rc_in_persist ||
8858 		    (rack->rc_tp->snd_max == rack->rc_tp->snd_una) ||
8859 		    (pkt_delta < tcp_sad_low_pps)){
8860 			/*
8861 			 * We don't decay idle connections
8862 			 * or ones that have a low input pps.
8863 			 */
8864 			return;
8865 		}
8866 		/* Decay the counters */
8867 		rack->r_ctl.ack_count = ctf_decay_count(rack->r_ctl.ack_count,
8868 							tcp_sad_decay_val);
8869 		rack->r_ctl.sack_count = ctf_decay_count(rack->r_ctl.sack_count,
8870 							 tcp_sad_decay_val);
8871 		rack->r_ctl.sack_moved_extra = ctf_decay_count(rack->r_ctl.sack_moved_extra,
8872 							       tcp_sad_decay_val);
8873 		rack->r_ctl.sack_noextra_move = ctf_decay_count(rack->r_ctl.sack_noextra_move,
8874 								tcp_sad_decay_val);
8875 #endif
8876 	}
8877 }
8878 
8879 static void
8880 rack_process_to_cumack(struct tcpcb *tp, struct tcp_rack *rack, register uint32_t th_ack, uint32_t cts, struct tcpopt *to)
8881 {
8882 	struct rack_sendmap *rsm;
8883 #ifdef INVARIANTS
8884 	struct rack_sendmap *rm;
8885 #endif
8886 
8887 	/*
8888 	 * The ACK point is advancing to th_ack, we must drop off
8889 	 * the packets in the rack log and calculate any eligble
8890 	 * RTT's.
8891 	 */
8892 	rack->r_wanted_output = 1;
8893 
8894 	/* Tend any TLP that has been marked for 1/2 the seq space (its old)  */
8895 	if ((rack->rc_last_tlp_acked_set == 1)&&
8896 	    (rack->rc_last_tlp_past_cumack == 1) &&
8897 	    (SEQ_GT(rack->r_ctl.last_tlp_acked_start, th_ack))) {
8898 		/*
8899 		 * We have reached the point where our last rack
8900 		 * tlp retransmit sequence is ahead of the cum-ack.
8901 		 * This can only happen when the cum-ack moves all
8902 		 * the way around (its been a full 2^^31+1 bytes
8903 		 * or more since we sent a retransmitted TLP). Lets
8904 		 * turn off the valid flag since its not really valid.
8905 		 *
8906 		 * Note since sack's also turn on this event we have
8907 		 * a complication, we have to wait to age it out until
8908 		 * the cum-ack is by the TLP before checking which is
8909 		 * what the next else clause does.
8910 		 */
8911 		rack_log_dsack_event(rack, 9, __LINE__,
8912 				     rack->r_ctl.last_tlp_acked_start,
8913 				     rack->r_ctl.last_tlp_acked_end);
8914 		rack->rc_last_tlp_acked_set = 0;
8915 		rack->rc_last_tlp_past_cumack = 0;
8916 	} else if ((rack->rc_last_tlp_acked_set == 1) &&
8917 		   (rack->rc_last_tlp_past_cumack == 0) &&
8918 		   (SEQ_GEQ(th_ack, rack->r_ctl.last_tlp_acked_end))) {
8919 		/*
8920 		 * It is safe to start aging TLP's out.
8921 		 */
8922 		rack->rc_last_tlp_past_cumack = 1;
8923 	}
8924 	/* We do the same for the tlp send seq as well */
8925 	if ((rack->rc_last_sent_tlp_seq_valid == 1) &&
8926 	    (rack->rc_last_sent_tlp_past_cumack == 1) &&
8927 	    (SEQ_GT(rack->r_ctl.last_sent_tlp_seq,  th_ack))) {
8928 		rack_log_dsack_event(rack, 9, __LINE__,
8929 				     rack->r_ctl.last_sent_tlp_seq,
8930 				     (rack->r_ctl.last_sent_tlp_seq +
8931 				      rack->r_ctl.last_sent_tlp_len));
8932 		rack->rc_last_sent_tlp_seq_valid = 0;
8933 		rack->rc_last_sent_tlp_past_cumack = 0;
8934 	} else if ((rack->rc_last_sent_tlp_seq_valid == 1) &&
8935 		   (rack->rc_last_sent_tlp_past_cumack == 0) &&
8936 		   (SEQ_GEQ(th_ack, rack->r_ctl.last_sent_tlp_seq))) {
8937 		/*
8938 		 * It is safe to start aging TLP's send.
8939 		 */
8940 		rack->rc_last_sent_tlp_past_cumack = 1;
8941 	}
8942 more:
8943 	rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
8944 	if (rsm == NULL) {
8945 		if ((th_ack - 1) == tp->iss) {
8946 			/*
8947 			 * For the SYN incoming case we will not
8948 			 * have called tcp_output for the sending of
8949 			 * the SYN, so there will be no map. All
8950 			 * other cases should probably be a panic.
8951 			 */
8952 			return;
8953 		}
8954 		if (tp->t_flags & TF_SENTFIN) {
8955 			/* if we sent a FIN we often will not have map */
8956 			return;
8957 		}
8958 #ifdef INVARIANTS
8959 		panic("No rack map tp:%p for state:%d ack:%u rack:%p snd_una:%u snd_max:%u snd_nxt:%u\n",
8960 		      tp,
8961 		      tp->t_state, th_ack, rack,
8962 		      tp->snd_una, tp->snd_max, tp->snd_nxt);
8963 #endif
8964 		return;
8965 	}
8966 	if (SEQ_LT(th_ack, rsm->r_start)) {
8967 		/* Huh map is missing this */
8968 #ifdef INVARIANTS
8969 		printf("Rack map starts at r_start:%u for th_ack:%u huh? ts:%d rs:%d\n",
8970 		       rsm->r_start,
8971 		       th_ack, tp->t_state, rack->r_state);
8972 #endif
8973 		return;
8974 	}
8975 	rack_update_rtt(tp, rack, rsm, to, cts, CUM_ACKED, th_ack);
8976 
8977 	/* Now was it a retransmitted TLP? */
8978 	if ((rsm->r_flags & RACK_TLP) &&
8979 	    (rsm->r_rtr_cnt > 1)) {
8980 		/*
8981 		 * Yes, this rsm was a TLP and retransmitted, remember that
8982 		 * since if a DSACK comes back on this we don't want
8983 		 * to think of it as a reordered segment. This may
8984 		 * get updated again with possibly even other TLPs
8985 		 * in flight, but thats ok. Only when we don't send
8986 		 * a retransmitted TLP for 1/2 the sequences space
8987 		 * will it get turned off (above).
8988 		 */
8989 		if (rack->rc_last_tlp_acked_set &&
8990 		    (is_rsm_inside_declared_tlp_block(rack, rsm))) {
8991 			/*
8992 			 * We already turned this on since the end matches,
8993 			 * the previous one was a partially ack now we
8994 			 * are getting another one (maybe all of it).
8995 			 */
8996 			rack_log_dsack_event(rack, 10, __LINE__, rsm->r_start, rsm->r_end);
8997 			/*
8998 			 * Lets make sure we have all of it though.
8999 			 */
9000 			if (SEQ_LT(rsm->r_start, rack->r_ctl.last_tlp_acked_start)) {
9001 				rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9002 				rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9003 						     rack->r_ctl.last_tlp_acked_end);
9004 			}
9005 			if (SEQ_GT(rsm->r_end, rack->r_ctl.last_tlp_acked_end)) {
9006 				rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9007 				rack_log_dsack_event(rack, 11, __LINE__, rack->r_ctl.last_tlp_acked_start,
9008 						     rack->r_ctl.last_tlp_acked_end);
9009 			}
9010 		} else {
9011 			rack->rc_last_tlp_past_cumack = 1;
9012 			rack->r_ctl.last_tlp_acked_start = rsm->r_start;
9013 			rack->r_ctl.last_tlp_acked_end = rsm->r_end;
9014 			rack->rc_last_tlp_acked_set = 1;
9015 			rack_log_dsack_event(rack, 8, __LINE__, rsm->r_start, rsm->r_end);
9016 		}
9017 	}
9018 	/* Now do we consume the whole thing? */
9019 	if (SEQ_GEQ(th_ack, rsm->r_end)) {
9020 		/* Its all consumed. */
9021 		uint32_t left;
9022 		uint8_t newly_acked;
9023 
9024 		rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_FREE, rsm->r_end, __LINE__);
9025 		rack->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
9026 		rsm->r_rtr_bytes = 0;
9027 		/* Record the time of highest cumack sent */
9028 		rack->r_ctl.rc_gp_cumack_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
9029 #ifndef INVARIANTS
9030 		(void)RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
9031 #else
9032 		rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
9033 		if (rm != rsm) {
9034 			panic("removing head in rack:%p rsm:%p rm:%p",
9035 			      rack, rsm, rm);
9036 		}
9037 #endif
9038 		if (rsm->r_in_tmap) {
9039 			TAILQ_REMOVE(&rack->r_ctl.rc_tmap, rsm, r_tnext);
9040 			rsm->r_in_tmap = 0;
9041 		}
9042 		newly_acked = 1;
9043 		if (rsm->r_flags & RACK_ACKED) {
9044 			/*
9045 			 * It was acked on the scoreboard -- remove
9046 			 * it from total
9047 			 */
9048 			rack->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
9049 			newly_acked = 0;
9050 		} else if (rsm->r_flags & RACK_SACK_PASSED) {
9051 			/*
9052 			 * There are segments ACKED on the
9053 			 * scoreboard further up. We are seeing
9054 			 * reordering.
9055 			 */
9056 			rsm->r_flags &= ~RACK_SACK_PASSED;
9057 			rsm->r_ack_arrival = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
9058 			rsm->r_flags |= RACK_ACKED;
9059 			rack->r_ctl.rc_reorder_ts = cts;
9060 			if (rack->r_ent_rec_ns) {
9061 				/*
9062 				 * We have sent no more, and we saw an sack
9063 				 * then ack arrive.
9064 				 */
9065 				rack->r_might_revert = 1;
9066 			}
9067 		}
9068 		if ((rsm->r_flags & RACK_TO_REXT) &&
9069 		    (tp->t_flags & TF_RCVD_TSTMP) &&
9070 		    (to->to_flags & TOF_TS) &&
9071 		    (to->to_tsecr != 0) &&
9072 		    (tp->t_flags & TF_PREVVALID)) {
9073 			/*
9074 			 * We can use the timestamp to see
9075 			 * if this retransmission was from the
9076 			 * first transmit. If so we made a mistake.
9077 			 */
9078 			tp->t_flags &= ~TF_PREVVALID;
9079 			if (to->to_tsecr == rack_ts_to_msec(rsm->r_tim_lastsent[0])) {
9080 				/* The first transmit is what this ack is for */
9081 				rack_cong_signal(tp, CC_RTO_ERR, th_ack, __LINE__);
9082 			}
9083 		}
9084 		left = th_ack - rsm->r_end;
9085 		if (rack->app_limited_needs_set && newly_acked)
9086 			rack_need_set_test(tp, rack, rsm, th_ack, __LINE__, RACK_USE_END_OR_THACK);
9087 		/* Free back to zone */
9088 		rack_free(rack, rsm);
9089 		if (left) {
9090 			goto more;
9091 		}
9092 		/* Check for reneging */
9093 		rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
9094 		if (rsm && (rsm->r_flags & RACK_ACKED) && (th_ack == rsm->r_start)) {
9095 			/*
9096 			 * The peer has moved snd_una up to
9097 			 * the edge of this send, i.e. one
9098 			 * that it had previously acked. The only
9099 			 * way that can be true if the peer threw
9100 			 * away data (space issues) that it had
9101 			 * previously sacked (else it would have
9102 			 * given us snd_una up to (rsm->r_end).
9103 			 * We need to undo the acked markings here.
9104 			 *
9105 			 * Note we have to look to make sure th_ack is
9106 			 * our rsm->r_start in case we get an old ack
9107 			 * where th_ack is behind snd_una.
9108 			 */
9109 			rack_peer_reneges(rack, rsm, th_ack);
9110 		}
9111 		return;
9112 	}
9113 	if (rsm->r_flags & RACK_ACKED) {
9114 		/*
9115 		 * It was acked on the scoreboard -- remove it from
9116 		 * total for the part being cum-acked.
9117 		 */
9118 		rack->r_ctl.rc_sacked -= (th_ack - rsm->r_start);
9119 	}
9120 	/*
9121 	 * Clear the dup ack count for
9122 	 * the piece that remains.
9123 	 */
9124 	rsm->r_dupack = 0;
9125 	rack_log_retran_reason(rack, rsm, __LINE__, 0, 2);
9126 	if (rsm->r_rtr_bytes) {
9127 		/*
9128 		 * It was retransmitted adjust the
9129 		 * sack holes for what was acked.
9130 		 */
9131 		int ack_am;
9132 
9133 		ack_am = (th_ack - rsm->r_start);
9134 		if (ack_am >= rsm->r_rtr_bytes) {
9135 			rack->r_ctl.rc_holes_rxt -= ack_am;
9136 			rsm->r_rtr_bytes -= ack_am;
9137 		}
9138 	}
9139 	/*
9140 	 * Update where the piece starts and record
9141 	 * the time of send of highest cumack sent.
9142 	 */
9143 	rack->r_ctl.rc_gp_cumack_ts = rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)];
9144 	rack_log_map_chg(tp, rack, NULL, rsm, NULL, MAP_TRIM_HEAD, th_ack, __LINE__);
9145 	/* Now we need to move our offset forward too */
9146 	if (rsm->m && (rsm->orig_m_len != rsm->m->m_len)) {
9147 		/* Fix up the orig_m_len and possibly the mbuf offset */
9148 		rack_adjust_orig_mlen(rsm);
9149 	}
9150 	rsm->soff += (th_ack - rsm->r_start);
9151 	rsm->r_start = th_ack;
9152 	/* Now do we need to move the mbuf fwd too? */
9153 	if (rsm->m) {
9154 		while (rsm->soff >= rsm->m->m_len) {
9155 			rsm->soff -= rsm->m->m_len;
9156 			rsm->m = rsm->m->m_next;
9157 			KASSERT((rsm->m != NULL),
9158 				(" nrsm:%p hit at soff:%u null m",
9159 				 rsm, rsm->soff));
9160 		}
9161 		rsm->orig_m_len = rsm->m->m_len;
9162 	}
9163 	if (rack->app_limited_needs_set)
9164 		rack_need_set_test(tp, rack, rsm, tp->snd_una, __LINE__, RACK_USE_BEG);
9165 }
9166 
9167 static void
9168 rack_handle_might_revert(struct tcpcb *tp, struct tcp_rack *rack)
9169 {
9170 	struct rack_sendmap *rsm;
9171 	int sack_pass_fnd = 0;
9172 
9173 	if (rack->r_might_revert) {
9174 		/*
9175 		 * Ok we have reordering, have not sent anything, we
9176 		 * might want to revert the congestion state if nothing
9177 		 * further has SACK_PASSED on it. Lets check.
9178 		 *
9179 		 * We also get here when we have DSACKs come in for
9180 		 * all the data that we FR'd. Note that a rxt or tlp
9181 		 * timer clears this from happening.
9182 		 */
9183 
9184 		TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
9185 			if (rsm->r_flags & RACK_SACK_PASSED) {
9186 				sack_pass_fnd = 1;
9187 				break;
9188 			}
9189 		}
9190 		if (sack_pass_fnd == 0) {
9191 			/*
9192 			 * We went into recovery
9193 			 * incorrectly due to reordering!
9194 			 */
9195 			int orig_cwnd;
9196 
9197 			rack->r_ent_rec_ns = 0;
9198 			orig_cwnd = tp->snd_cwnd;
9199 			tp->snd_ssthresh = rack->r_ctl.rc_ssthresh_at_erec;
9200 			tp->snd_recover = tp->snd_una;
9201 			rack_log_to_prr(rack, 14, orig_cwnd, __LINE__);
9202 			EXIT_RECOVERY(tp->t_flags);
9203 		}
9204 		rack->r_might_revert = 0;
9205 	}
9206 }
9207 
9208 #ifdef NETFLIX_EXP_DETECTION
9209 static void
9210 rack_do_detection(struct tcpcb *tp, struct tcp_rack *rack,  uint32_t bytes_this_ack, uint32_t segsiz)
9211 {
9212 	if ((rack->do_detection || tcp_force_detection) &&
9213 	    tcp_sack_to_ack_thresh &&
9214 	    tcp_sack_to_move_thresh &&
9215 	    ((rack->r_ctl.rc_num_maps_alloced > tcp_map_minimum) || rack->sack_attack_disable)) {
9216 		/*
9217 		 * We have thresholds set to find
9218 		 * possible attackers and disable sack.
9219 		 * Check them.
9220 		 */
9221 		uint64_t ackratio, moveratio, movetotal;
9222 
9223 		/* Log detecting */
9224 		rack_log_sad(rack, 1);
9225 		ackratio = (uint64_t)(rack->r_ctl.sack_count);
9226 		ackratio *= (uint64_t)(1000);
9227 		if (rack->r_ctl.ack_count)
9228 			ackratio /= (uint64_t)(rack->r_ctl.ack_count);
9229 		else {
9230 			/* We really should not hit here */
9231 			ackratio = 1000;
9232 		}
9233 		if ((rack->sack_attack_disable == 0) &&
9234 		    (ackratio > rack_highest_sack_thresh_seen))
9235 			rack_highest_sack_thresh_seen = (uint32_t)ackratio;
9236 		movetotal = rack->r_ctl.sack_moved_extra;
9237 		movetotal += rack->r_ctl.sack_noextra_move;
9238 		moveratio = rack->r_ctl.sack_moved_extra;
9239 		moveratio *= (uint64_t)1000;
9240 		if (movetotal)
9241 			moveratio /= movetotal;
9242 		else {
9243 			/* No moves, thats pretty good */
9244 			moveratio = 0;
9245 		}
9246 		if ((rack->sack_attack_disable == 0) &&
9247 		    (moveratio > rack_highest_move_thresh_seen))
9248 			rack_highest_move_thresh_seen = (uint32_t)moveratio;
9249 		if (rack->sack_attack_disable == 0) {
9250 			if ((ackratio > tcp_sack_to_ack_thresh) &&
9251 			    (moveratio > tcp_sack_to_move_thresh)) {
9252 				/* Disable sack processing */
9253 				rack->sack_attack_disable = 1;
9254 				if (rack->r_rep_attack == 0) {
9255 					rack->r_rep_attack = 1;
9256 					counter_u64_add(rack_sack_attacks_detected, 1);
9257 				}
9258 				if (tcp_attack_on_turns_on_logging) {
9259 					/*
9260 					 * Turn on logging, used for debugging
9261 					 * false positives.
9262 					 */
9263 					rack->rc_tp->t_logstate = tcp_attack_on_turns_on_logging;
9264 				}
9265 				/* Clamp the cwnd at flight size */
9266 				rack->r_ctl.rc_saved_cwnd = rack->rc_tp->snd_cwnd;
9267 				rack->rc_tp->snd_cwnd = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
9268 				rack_log_sad(rack, 2);
9269 			}
9270 		} else {
9271 			/* We are sack-disabled check for false positives */
9272 			if ((ackratio <= tcp_restoral_thresh) ||
9273 			    (rack->r_ctl.rc_num_maps_alloced  < tcp_map_minimum)) {
9274 				rack->sack_attack_disable = 0;
9275 				rack_log_sad(rack, 3);
9276 				/* Restart counting */
9277 				rack->r_ctl.sack_count = 0;
9278 				rack->r_ctl.sack_moved_extra = 0;
9279 				rack->r_ctl.sack_noextra_move = 1;
9280 				rack->r_ctl.ack_count = max(1,
9281 				      (bytes_this_ack / segsiz));
9282 
9283 				if (rack->r_rep_reverse == 0) {
9284 					rack->r_rep_reverse = 1;
9285 					counter_u64_add(rack_sack_attacks_reversed, 1);
9286 				}
9287 				/* Restore the cwnd */
9288 				if (rack->r_ctl.rc_saved_cwnd > rack->rc_tp->snd_cwnd)
9289 					rack->rc_tp->snd_cwnd = rack->r_ctl.rc_saved_cwnd;
9290 			}
9291 		}
9292 	}
9293 }
9294 #endif
9295 
9296 static int
9297 rack_note_dsack(struct tcp_rack *rack, tcp_seq start, tcp_seq end)
9298 {
9299 
9300 	uint32_t am, l_end;
9301 	int was_tlp = 0;
9302 
9303 	if (SEQ_GT(end, start))
9304 		am = end - start;
9305 	else
9306 		am = 0;
9307 	if ((rack->rc_last_tlp_acked_set ) &&
9308 	    (SEQ_GEQ(start, rack->r_ctl.last_tlp_acked_start)) &&
9309 	    (SEQ_LEQ(end, rack->r_ctl.last_tlp_acked_end))) {
9310 		/*
9311 		 * The DSACK is because of a TLP which we don't
9312 		 * do anything with the reordering window over since
9313 		 * it was not reordering that caused the DSACK but
9314 		 * our previous retransmit TLP.
9315 		 */
9316 		rack_log_dsack_event(rack, 7, __LINE__, start, end);
9317 		was_tlp = 1;
9318 		goto skip_dsack_round;
9319 	}
9320 	if (rack->rc_last_sent_tlp_seq_valid) {
9321 		l_end = rack->r_ctl.last_sent_tlp_seq + rack->r_ctl.last_sent_tlp_len;
9322 		if (SEQ_GEQ(start, rack->r_ctl.last_sent_tlp_seq) &&
9323 		    (SEQ_LEQ(end, l_end))) {
9324 			/*
9325 			 * This dsack is from the last sent TLP, ignore it
9326 			 * for reordering purposes.
9327 			 */
9328 			rack_log_dsack_event(rack, 7, __LINE__, start, end);
9329 			was_tlp = 1;
9330 			goto skip_dsack_round;
9331 		}
9332 	}
9333 	if (rack->rc_dsack_round_seen == 0) {
9334 		rack->rc_dsack_round_seen = 1;
9335 		rack->r_ctl.dsack_round_end = rack->rc_tp->snd_max;
9336 		rack->r_ctl.num_dsack++;
9337 		rack->r_ctl.dsack_persist = 16;	/* 16 is from the standard */
9338 		rack_log_dsack_event(rack, 2, __LINE__, 0, 0);
9339 	}
9340 skip_dsack_round:
9341 	/*
9342 	 * We keep track of how many DSACK blocks we get
9343 	 * after a recovery incident.
9344 	 */
9345 	rack->r_ctl.dsack_byte_cnt += am;
9346 	if (!IN_FASTRECOVERY(rack->rc_tp->t_flags) &&
9347 	    rack->r_ctl.retran_during_recovery &&
9348 	    (rack->r_ctl.dsack_byte_cnt >= rack->r_ctl.retran_during_recovery)) {
9349 		/*
9350 		 * False recovery most likely culprit is reordering. If
9351 		 * nothing else is missing we need to revert.
9352 		 */
9353 		rack->r_might_revert = 1;
9354 		rack_handle_might_revert(rack->rc_tp, rack);
9355 		rack->r_might_revert = 0;
9356 		rack->r_ctl.retran_during_recovery = 0;
9357 		rack->r_ctl.dsack_byte_cnt = 0;
9358 	}
9359 	return (was_tlp);
9360 }
9361 
9362 static void
9363 rack_update_prr(struct tcpcb *tp, struct tcp_rack *rack, uint32_t changed, tcp_seq th_ack)
9364 {
9365 	/* Deal with changed and PRR here (in recovery only) */
9366 	uint32_t pipe, snd_una;
9367 
9368 	rack->r_ctl.rc_prr_delivered += changed;
9369 
9370 	if (sbavail(&rack->rc_inp->inp_socket->so_snd) <= (tp->snd_max - tp->snd_una)) {
9371 		/*
9372 		 * It is all outstanding, we are application limited
9373 		 * and thus we don't need more room to send anything.
9374 		 * Note we use tp->snd_una here and not th_ack because
9375 		 * the data as yet not been cut from the sb.
9376 		 */
9377 		rack->r_ctl.rc_prr_sndcnt = 0;
9378 		return;
9379 	}
9380 	/* Compute prr_sndcnt */
9381 	if (SEQ_GT(tp->snd_una, th_ack)) {
9382 		snd_una = tp->snd_una;
9383 	} else {
9384 		snd_una = th_ack;
9385 	}
9386 	pipe = ((tp->snd_max - snd_una) - rack->r_ctl.rc_sacked) + rack->r_ctl.rc_holes_rxt;
9387 	if (pipe > tp->snd_ssthresh) {
9388 		long sndcnt;
9389 
9390 		sndcnt = rack->r_ctl.rc_prr_delivered * tp->snd_ssthresh;
9391 		if (rack->r_ctl.rc_prr_recovery_fs > 0)
9392 			sndcnt /= (long)rack->r_ctl.rc_prr_recovery_fs;
9393 		else {
9394 			rack->r_ctl.rc_prr_sndcnt = 0;
9395 			rack_log_to_prr(rack, 9, 0, __LINE__);
9396 			sndcnt = 0;
9397 		}
9398 		sndcnt++;
9399 		if (sndcnt > (long)rack->r_ctl.rc_prr_out)
9400 			sndcnt -= rack->r_ctl.rc_prr_out;
9401 		else
9402 			sndcnt = 0;
9403 		rack->r_ctl.rc_prr_sndcnt = sndcnt;
9404 		rack_log_to_prr(rack, 10, 0, __LINE__);
9405 	} else {
9406 		uint32_t limit;
9407 
9408 		if (rack->r_ctl.rc_prr_delivered > rack->r_ctl.rc_prr_out)
9409 			limit = (rack->r_ctl.rc_prr_delivered - rack->r_ctl.rc_prr_out);
9410 		else
9411 			limit = 0;
9412 		if (changed > limit)
9413 			limit = changed;
9414 		limit += ctf_fixed_maxseg(tp);
9415 		if (tp->snd_ssthresh > pipe) {
9416 			rack->r_ctl.rc_prr_sndcnt = min((tp->snd_ssthresh - pipe), limit);
9417 			rack_log_to_prr(rack, 11, 0, __LINE__);
9418 		} else {
9419 			rack->r_ctl.rc_prr_sndcnt = min(0, limit);
9420 			rack_log_to_prr(rack, 12, 0, __LINE__);
9421 		}
9422 	}
9423 }
9424 
9425 static void
9426 rack_log_ack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th, int entered_recovery, int dup_ack_struck)
9427 {
9428 	uint32_t changed;
9429 	struct tcp_rack *rack;
9430 	struct rack_sendmap *rsm;
9431 	struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1];
9432 	register uint32_t th_ack;
9433 	int32_t i, j, k, num_sack_blks = 0;
9434 	uint32_t cts, acked, ack_point;
9435 	int loop_start = 0, moved_two = 0;
9436 	uint32_t tsused;
9437 
9438 
9439 	INP_WLOCK_ASSERT(tp->t_inpcb);
9440 	if (tcp_get_flags(th) & TH_RST) {
9441 		/* We don't log resets */
9442 		return;
9443 	}
9444 	rack = (struct tcp_rack *)tp->t_fb_ptr;
9445 	cts = tcp_get_usecs(NULL);
9446 	rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
9447 	changed = 0;
9448 	th_ack = th->th_ack;
9449 	if (rack->sack_attack_disable == 0)
9450 		rack_do_decay(rack);
9451 	if (BYTES_THIS_ACK(tp, th) >= ctf_fixed_maxseg(rack->rc_tp)) {
9452 		/*
9453 		 * You only get credit for
9454 		 * MSS and greater (and you get extra
9455 		 * credit for larger cum-ack moves).
9456 		 */
9457 		int ac;
9458 
9459 		ac = BYTES_THIS_ACK(tp, th) / ctf_fixed_maxseg(rack->rc_tp);
9460 		rack->r_ctl.ack_count += ac;
9461 		counter_u64_add(rack_ack_total, ac);
9462 	}
9463 	if (rack->r_ctl.ack_count > 0xfff00000) {
9464 		/*
9465 		 * reduce the number to keep us under
9466 		 * a uint32_t.
9467 		 */
9468 		rack->r_ctl.ack_count /= 2;
9469 		rack->r_ctl.sack_count /= 2;
9470 	}
9471 	if (SEQ_GT(th_ack, tp->snd_una)) {
9472 		rack_log_progress_event(rack, tp, ticks, PROGRESS_UPDATE, __LINE__);
9473 		tp->t_acktime = ticks;
9474 	}
9475 	if (rsm && SEQ_GT(th_ack, rsm->r_start))
9476 		changed = th_ack - rsm->r_start;
9477 	if (changed) {
9478 		rack_process_to_cumack(tp, rack, th_ack, cts, to);
9479 	}
9480 	if ((to->to_flags & TOF_SACK) == 0) {
9481 		/* We are done nothing left and no sack. */
9482 		rack_handle_might_revert(tp, rack);
9483 		/*
9484 		 * For cases where we struck a dup-ack
9485 		 * with no SACK, add to the changes so
9486 		 * PRR will work right.
9487 		 */
9488 		if (dup_ack_struck && (changed == 0)) {
9489 			changed += ctf_fixed_maxseg(rack->rc_tp);
9490 		}
9491 		goto out;
9492 	}
9493 	/* Sack block processing */
9494 	if (SEQ_GT(th_ack, tp->snd_una))
9495 		ack_point = th_ack;
9496 	else
9497 		ack_point = tp->snd_una;
9498 	for (i = 0; i < to->to_nsacks; i++) {
9499 		bcopy((to->to_sacks + i * TCPOLEN_SACK),
9500 		      &sack, sizeof(sack));
9501 		sack.start = ntohl(sack.start);
9502 		sack.end = ntohl(sack.end);
9503 		if (SEQ_GT(sack.end, sack.start) &&
9504 		    SEQ_GT(sack.start, ack_point) &&
9505 		    SEQ_LT(sack.start, tp->snd_max) &&
9506 		    SEQ_GT(sack.end, ack_point) &&
9507 		    SEQ_LEQ(sack.end, tp->snd_max)) {
9508 			sack_blocks[num_sack_blks] = sack;
9509 			num_sack_blks++;
9510 		} else if (SEQ_LEQ(sack.start, th_ack) &&
9511 			   SEQ_LEQ(sack.end, th_ack)) {
9512 			int was_tlp;
9513 
9514 			was_tlp = rack_note_dsack(rack, sack.start, sack.end);
9515 			/*
9516 			 * Its a D-SACK block.
9517 			 */
9518 			tcp_record_dsack(tp, sack.start, sack.end, was_tlp);
9519 		}
9520 	}
9521 	if (rack->rc_dsack_round_seen) {
9522 		/* Is the dsack roound over? */
9523 		if (SEQ_GEQ(th_ack, rack->r_ctl.dsack_round_end)) {
9524 			/* Yes it is */
9525 			rack->rc_dsack_round_seen = 0;
9526 			rack_log_dsack_event(rack, 3, __LINE__, 0, 0);
9527 		}
9528 	}
9529 	/*
9530 	 * Sort the SACK blocks so we can update the rack scoreboard with
9531 	 * just one pass.
9532 	 */
9533 	num_sack_blks = sack_filter_blks(&rack->r_ctl.rack_sf, sack_blocks,
9534 					 num_sack_blks, th->th_ack);
9535 	ctf_log_sack_filter(rack->rc_tp, num_sack_blks, sack_blocks);
9536 	if (num_sack_blks == 0) {
9537 		/* Nothing to sack (DSACKs?) */
9538 		goto out_with_totals;
9539 	}
9540 	if (num_sack_blks < 2) {
9541 		/* Only one, we don't need to sort */
9542 		goto do_sack_work;
9543 	}
9544 	/* Sort the sacks */
9545 	for (i = 0; i < num_sack_blks; i++) {
9546 		for (j = i + 1; j < num_sack_blks; j++) {
9547 			if (SEQ_GT(sack_blocks[i].end, sack_blocks[j].end)) {
9548 				sack = sack_blocks[i];
9549 				sack_blocks[i] = sack_blocks[j];
9550 				sack_blocks[j] = sack;
9551 			}
9552 		}
9553 	}
9554 	/*
9555 	 * Now are any of the sack block ends the same (yes some
9556 	 * implementations send these)?
9557 	 */
9558 again:
9559 	if (num_sack_blks == 0)
9560 		goto out_with_totals;
9561 	if (num_sack_blks > 1) {
9562 		for (i = 0; i < num_sack_blks; i++) {
9563 			for (j = i + 1; j < num_sack_blks; j++) {
9564 				if (sack_blocks[i].end == sack_blocks[j].end) {
9565 					/*
9566 					 * Ok these two have the same end we
9567 					 * want the smallest end and then
9568 					 * throw away the larger and start
9569 					 * again.
9570 					 */
9571 					if (SEQ_LT(sack_blocks[j].start, sack_blocks[i].start)) {
9572 						/*
9573 						 * The second block covers
9574 						 * more area use that
9575 						 */
9576 						sack_blocks[i].start = sack_blocks[j].start;
9577 					}
9578 					/*
9579 					 * Now collapse out the dup-sack and
9580 					 * lower the count
9581 					 */
9582 					for (k = (j + 1); k < num_sack_blks; k++) {
9583 						sack_blocks[j].start = sack_blocks[k].start;
9584 						sack_blocks[j].end = sack_blocks[k].end;
9585 						j++;
9586 					}
9587 					num_sack_blks--;
9588 					goto again;
9589 				}
9590 			}
9591 		}
9592 	}
9593 do_sack_work:
9594 	/*
9595 	 * First lets look to see if
9596 	 * we have retransmitted and
9597 	 * can use the transmit next?
9598 	 */
9599 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
9600 	if (rsm &&
9601 	    SEQ_GT(sack_blocks[0].end, rsm->r_start) &&
9602 	    SEQ_LT(sack_blocks[0].start, rsm->r_end)) {
9603 		/*
9604 		 * We probably did the FR and the next
9605 		 * SACK in continues as we would expect.
9606 		 */
9607 		acked = rack_proc_sack_blk(tp, rack, &sack_blocks[0], to, &rsm, cts, &moved_two);
9608 		if (acked) {
9609 			rack->r_wanted_output = 1;
9610 			changed += acked;
9611 		}
9612 		if (num_sack_blks == 1) {
9613 			/*
9614 			 * This is what we would expect from
9615 			 * a normal implementation to happen
9616 			 * after we have retransmitted the FR,
9617 			 * i.e the sack-filter pushes down
9618 			 * to 1 block and the next to be retransmitted
9619 			 * is the sequence in the sack block (has more
9620 			 * are acked). Count this as ACK'd data to boost
9621 			 * up the chances of recovering any false positives.
9622 			 */
9623 			rack->r_ctl.ack_count += (acked / ctf_fixed_maxseg(rack->rc_tp));
9624 			counter_u64_add(rack_ack_total, (acked / ctf_fixed_maxseg(rack->rc_tp)));
9625 			counter_u64_add(rack_express_sack, 1);
9626 			if (rack->r_ctl.ack_count > 0xfff00000) {
9627 				/*
9628 				 * reduce the number to keep us under
9629 				 * a uint32_t.
9630 				 */
9631 				rack->r_ctl.ack_count /= 2;
9632 				rack->r_ctl.sack_count /= 2;
9633 			}
9634 			goto out_with_totals;
9635 		} else {
9636 			/*
9637 			 * Start the loop through the
9638 			 * rest of blocks, past the first block.
9639 			 */
9640 			moved_two = 0;
9641 			loop_start = 1;
9642 		}
9643 	}
9644 	/* Its a sack of some sort */
9645 	rack->r_ctl.sack_count++;
9646 	if (rack->r_ctl.sack_count > 0xfff00000) {
9647 		/*
9648 		 * reduce the number to keep us under
9649 		 * a uint32_t.
9650 		 */
9651 		rack->r_ctl.ack_count /= 2;
9652 		rack->r_ctl.sack_count /= 2;
9653 	}
9654 	counter_u64_add(rack_sack_total, 1);
9655 	if (rack->sack_attack_disable) {
9656 		/* An attacker disablement is in place */
9657 		if (num_sack_blks > 1) {
9658 			rack->r_ctl.sack_count += (num_sack_blks - 1);
9659 			rack->r_ctl.sack_moved_extra++;
9660 			counter_u64_add(rack_move_some, 1);
9661 			if (rack->r_ctl.sack_moved_extra > 0xfff00000) {
9662 				rack->r_ctl.sack_moved_extra /= 2;
9663 				rack->r_ctl.sack_noextra_move /= 2;
9664 			}
9665 		}
9666 		goto out;
9667 	}
9668 	rsm = rack->r_ctl.rc_sacklast;
9669 	for (i = loop_start; i < num_sack_blks; i++) {
9670 		acked = rack_proc_sack_blk(tp, rack, &sack_blocks[i], to, &rsm, cts, &moved_two);
9671 		if (acked) {
9672 			rack->r_wanted_output = 1;
9673 			changed += acked;
9674 		}
9675 		if (moved_two) {
9676 			/*
9677 			 * If we did not get a SACK for at least a MSS and
9678 			 * had to move at all, or if we moved more than our
9679 			 * threshold, it counts against the "extra" move.
9680 			 */
9681 			rack->r_ctl.sack_moved_extra += moved_two;
9682 			counter_u64_add(rack_move_some, 1);
9683 		} else {
9684 			/*
9685 			 * else we did not have to move
9686 			 * any more than we would expect.
9687 			 */
9688 			rack->r_ctl.sack_noextra_move++;
9689 			counter_u64_add(rack_move_none, 1);
9690 		}
9691 		if (moved_two && (acked < ctf_fixed_maxseg(rack->rc_tp))) {
9692 			/*
9693 			 * If the SACK was not a full MSS then
9694 			 * we add to sack_count the number of
9695 			 * MSS's (or possibly more than
9696 			 * a MSS if its a TSO send) we had to skip by.
9697 			 */
9698 			rack->r_ctl.sack_count += moved_two;
9699 			counter_u64_add(rack_sack_total, moved_two);
9700 		}
9701 		/*
9702 		 * Now we need to setup for the next
9703 		 * round. First we make sure we won't
9704 		 * exceed the size of our uint32_t on
9705 		 * the various counts, and then clear out
9706 		 * moved_two.
9707 		 */
9708 		if ((rack->r_ctl.sack_moved_extra > 0xfff00000) ||
9709 		    (rack->r_ctl.sack_noextra_move > 0xfff00000)) {
9710 			rack->r_ctl.sack_moved_extra /= 2;
9711 			rack->r_ctl.sack_noextra_move /= 2;
9712 		}
9713 		if (rack->r_ctl.sack_count > 0xfff00000) {
9714 			rack->r_ctl.ack_count /= 2;
9715 			rack->r_ctl.sack_count /= 2;
9716 		}
9717 		moved_two = 0;
9718 	}
9719 out_with_totals:
9720 	if (num_sack_blks > 1) {
9721 		/*
9722 		 * You get an extra stroke if
9723 		 * you have more than one sack-blk, this
9724 		 * could be where we are skipping forward
9725 		 * and the sack-filter is still working, or
9726 		 * it could be an attacker constantly
9727 		 * moving us.
9728 		 */
9729 		rack->r_ctl.sack_moved_extra++;
9730 		counter_u64_add(rack_move_some, 1);
9731 	}
9732 out:
9733 #ifdef NETFLIX_EXP_DETECTION
9734 	rack_do_detection(tp, rack, BYTES_THIS_ACK(tp, th), ctf_fixed_maxseg(rack->rc_tp));
9735 #endif
9736 	if (changed) {
9737 		/* Something changed cancel the rack timer */
9738 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
9739 	}
9740 	tsused = tcp_get_usecs(NULL);
9741 	rsm = tcp_rack_output(tp, rack, tsused);
9742 	if ((!IN_FASTRECOVERY(tp->t_flags)) &&
9743 	    rsm &&
9744 	    ((rsm->r_flags & RACK_MUST_RXT) == 0)) {
9745 		/* Enter recovery */
9746 		entered_recovery = 1;
9747 		rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
9748 		/*
9749 		 * When we enter recovery we need to assure we send
9750 		 * one packet.
9751 		 */
9752 		if (rack->rack_no_prr == 0) {
9753 			rack->r_ctl.rc_prr_sndcnt = ctf_fixed_maxseg(tp);
9754 			rack_log_to_prr(rack, 8, 0, __LINE__);
9755 		}
9756 		rack->r_timer_override = 1;
9757 		rack->r_early = 0;
9758 		rack->r_ctl.rc_agg_early = 0;
9759 	} else if (IN_FASTRECOVERY(tp->t_flags) &&
9760 		   rsm &&
9761 		   (rack->r_rr_config == 3)) {
9762 		/*
9763 		 * Assure we can output and we get no
9764 		 * remembered pace time except the retransmit.
9765 		 */
9766 		rack->r_timer_override = 1;
9767 		rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
9768 		rack->r_ctl.rc_resend = rsm;
9769 	}
9770 	if (IN_FASTRECOVERY(tp->t_flags) &&
9771 	    (rack->rack_no_prr == 0) &&
9772 	    (entered_recovery == 0)) {
9773 		rack_update_prr(tp, rack, changed, th_ack);
9774 		if ((rsm && (rack->r_ctl.rc_prr_sndcnt >= ctf_fixed_maxseg(tp)) &&
9775 		     ((tcp_in_hpts(rack->rc_inp) == 0) &&
9776 		      ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0)))) {
9777 			/*
9778 			 * If you are pacing output you don't want
9779 			 * to override.
9780 			 */
9781 			rack->r_early = 0;
9782 			rack->r_ctl.rc_agg_early = 0;
9783 			rack->r_timer_override = 1;
9784 		}
9785 	}
9786 }
9787 
9788 static void
9789 rack_strike_dupack(struct tcp_rack *rack)
9790 {
9791 	struct rack_sendmap *rsm;
9792 
9793 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
9794 	while (rsm && (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
9795 		rsm = TAILQ_NEXT(rsm, r_tnext);
9796 		if (rsm->r_flags & RACK_MUST_RXT) {
9797 			/* Sendmap entries that are marked to
9798 			 * be retransmitted do not need dupack's
9799 			 * struck. We get these marks for a number
9800 			 * of reasons (rxt timeout with no sack,
9801 			 * mtu change, or rwnd collapses). When
9802 			 * these events occur, we know we must retransmit
9803 			 * them and mark the sendmap entries. Dupack counting
9804 			 * is not needed since we are already set to retransmit
9805 			 * it as soon as we can.
9806 			 */
9807 			continue;
9808 		}
9809 	}
9810 	if (rsm && (rsm->r_dupack < 0xff)) {
9811 		rsm->r_dupack++;
9812 		if (rsm->r_dupack >= DUP_ACK_THRESHOLD) {
9813 			struct timeval tv;
9814 			uint32_t cts;
9815 			/*
9816 			 * Here we see if we need to retransmit. For
9817 			 * a SACK type connection if enough time has passed
9818 			 * we will get a return of the rsm. For a non-sack
9819 			 * connection we will get the rsm returned if the
9820 			 * dupack value is 3 or more.
9821 			 */
9822 			cts = tcp_get_usecs(&tv);
9823 			rack->r_ctl.rc_resend = tcp_rack_output(rack->rc_tp, rack, cts);
9824 			if (rack->r_ctl.rc_resend != NULL) {
9825 				if (!IN_FASTRECOVERY(rack->rc_tp->t_flags)) {
9826 					rack_cong_signal(rack->rc_tp, CC_NDUPACK,
9827 							 rack->rc_tp->snd_una, __LINE__);
9828 				}
9829 				rack->r_wanted_output = 1;
9830 				rack->r_timer_override = 1;
9831 				rack_log_retran_reason(rack, rsm, __LINE__, 1, 3);
9832 			}
9833 		} else {
9834 			rack_log_retran_reason(rack, rsm, __LINE__, 0, 3);
9835 		}
9836 	}
9837 }
9838 
9839 static void
9840 rack_check_bottom_drag(struct tcpcb *tp,
9841 		       struct tcp_rack *rack,
9842 		       struct socket *so, int32_t acked)
9843 {
9844 	uint32_t segsiz, minseg;
9845 
9846 	segsiz = ctf_fixed_maxseg(tp);
9847 	minseg = segsiz;
9848 
9849 	if (tp->snd_max == tp->snd_una) {
9850 		/*
9851 		 * We are doing dynamic pacing and we are way
9852 		 * under. Basically everything got acked while
9853 		 * we were still waiting on the pacer to expire.
9854 		 *
9855 		 * This means we need to boost the b/w in
9856 		 * addition to any earlier boosting of
9857 		 * the multiplier.
9858 		 */
9859 		rack->rc_dragged_bottom = 1;
9860 		rack_validate_multipliers_at_or_above100(rack);
9861 		/*
9862 		 * Lets use the segment bytes acked plus
9863 		 * the lowest RTT seen as the basis to
9864 		 * form a b/w estimate. This will be off
9865 		 * due to the fact that the true estimate
9866 		 * should be around 1/2 the time of the RTT
9867 		 * but we can settle for that.
9868 		 */
9869 		if ((rack->r_ctl.rack_rs.rs_flags & RACK_RTT_VALID) &&
9870 		    acked) {
9871 			uint64_t bw, calc_bw, rtt;
9872 
9873 			rtt = rack->r_ctl.rack_rs.rs_us_rtt;
9874 			if (rtt == 0) {
9875 				/* no us sample is there a ms one? */
9876 				if (rack->r_ctl.rack_rs.rs_rtt_lowest) {
9877 					rtt = rack->r_ctl.rack_rs.rs_rtt_lowest;
9878 				} else {
9879 					goto no_measurement;
9880 				}
9881 			}
9882 			bw = acked;
9883 			calc_bw = bw * 1000000;
9884 			calc_bw /= rtt;
9885 			if (rack->r_ctl.last_max_bw &&
9886 			    (rack->r_ctl.last_max_bw < calc_bw)) {
9887 				/*
9888 				 * If we have a last calculated max bw
9889 				 * enforce it.
9890 				 */
9891 				calc_bw = rack->r_ctl.last_max_bw;
9892 			}
9893 			/* now plop it in */
9894 			if (rack->rc_gp_filled == 0) {
9895 				if (calc_bw > ONE_POINT_TWO_MEG) {
9896 					/*
9897 					 * If we have no measurement
9898 					 * don't let us set in more than
9899 					 * 1.2Mbps. If we are still too
9900 					 * low after pacing with this we
9901 					 * will hopefully have a max b/w
9902 					 * available to sanity check things.
9903 					 */
9904 					calc_bw = ONE_POINT_TWO_MEG;
9905 				}
9906 				rack->r_ctl.rc_rtt_diff = 0;
9907 				rack->r_ctl.gp_bw = calc_bw;
9908 				rack->rc_gp_filled = 1;
9909 				if (rack->r_ctl.num_measurements < RACK_REQ_AVG)
9910 					rack->r_ctl.num_measurements = RACK_REQ_AVG;
9911 				rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
9912 			} else if (calc_bw > rack->r_ctl.gp_bw) {
9913 				rack->r_ctl.rc_rtt_diff = 0;
9914 				if (rack->r_ctl.num_measurements < RACK_REQ_AVG)
9915 					rack->r_ctl.num_measurements = RACK_REQ_AVG;
9916 				rack->r_ctl.gp_bw = calc_bw;
9917 				rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
9918 			} else
9919 				rack_increase_bw_mul(rack, -1, 0, 0, 1);
9920 			if ((rack->gp_ready == 0) &&
9921 			    (rack->r_ctl.num_measurements >= rack->r_ctl.req_measurements)) {
9922 				/* We have enough measurements now */
9923 				rack->gp_ready = 1;
9924 				rack_set_cc_pacing(rack);
9925 				if (rack->defer_options)
9926 					rack_apply_deferred_options(rack);
9927 			}
9928 			/*
9929 			 * For acks over 1mss we do a extra boost to simulate
9930 			 * where we would get 2 acks (we want 110 for the mul).
9931 			 */
9932 			if (acked > segsiz)
9933 				rack_increase_bw_mul(rack, -1, 0, 0, 1);
9934 		} else {
9935 			/*
9936 			 * zero rtt possibly?, settle for just an old increase.
9937 			 */
9938 no_measurement:
9939 			rack_increase_bw_mul(rack, -1, 0, 0, 1);
9940 		}
9941 	} else if ((IN_FASTRECOVERY(tp->t_flags) == 0) &&
9942 		   (sbavail(&so->so_snd) > max((segsiz * (4 + rack_req_segs)),
9943 					       minseg)) &&
9944 		   (rack->r_ctl.cwnd_to_use > max((segsiz * (rack_req_segs + 2)), minseg)) &&
9945 		   (tp->snd_wnd > max((segsiz * (rack_req_segs + 2)), minseg)) &&
9946 		   (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) <=
9947 		    (segsiz * rack_req_segs))) {
9948 		/*
9949 		 * We are doing dynamic GP pacing and
9950 		 * we have everything except 1MSS or less
9951 		 * bytes left out. We are still pacing away.
9952 		 * And there is data that could be sent, This
9953 		 * means we are inserting delayed ack time in
9954 		 * our measurements because we are pacing too slow.
9955 		 */
9956 		rack_validate_multipliers_at_or_above100(rack);
9957 		rack->rc_dragged_bottom = 1;
9958 		rack_increase_bw_mul(rack, -1, 0, 0, 1);
9959 	}
9960 }
9961 
9962 
9963 
9964 static void
9965 rack_gain_for_fastoutput(struct tcp_rack *rack, struct tcpcb *tp, struct socket *so, uint32_t acked_amount)
9966 {
9967 	/*
9968 	 * The fast output path is enabled and we
9969 	 * have moved the cumack forward. Lets see if
9970 	 * we can expand forward the fast path length by
9971 	 * that amount. What we would ideally like to
9972 	 * do is increase the number of bytes in the
9973 	 * fast path block (left_to_send) by the
9974 	 * acked amount. However we have to gate that
9975 	 * by two factors:
9976 	 * 1) The amount outstanding and the rwnd of the peer
9977 	 *    (i.e. we don't want to exceed the rwnd of the peer).
9978 	 *    <and>
9979 	 * 2) The amount of data left in the socket buffer (i.e.
9980 	 *    we can't send beyond what is in the buffer).
9981 	 *
9982 	 * Note that this does not take into account any increase
9983 	 * in the cwnd. We will only extend the fast path by
9984 	 * what was acked.
9985 	 */
9986 	uint32_t new_total, gating_val;
9987 
9988 	new_total = acked_amount + rack->r_ctl.fsb.left_to_send;
9989 	gating_val = min((sbavail(&so->so_snd) - (tp->snd_max - tp->snd_una)),
9990 			 (tp->snd_wnd - (tp->snd_max - tp->snd_una)));
9991 	if (new_total <= gating_val) {
9992 		/* We can increase left_to_send by the acked amount */
9993 		counter_u64_add(rack_extended_rfo, 1);
9994 		rack->r_ctl.fsb.left_to_send = new_total;
9995 		KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(&rack->rc_inp->inp_socket->so_snd) - (tp->snd_max - tp->snd_una))),
9996 			("rack:%p left_to_send:%u sbavail:%u out:%u",
9997 			 rack, rack->r_ctl.fsb.left_to_send,
9998 			 sbavail(&rack->rc_inp->inp_socket->so_snd),
9999 			 (tp->snd_max - tp->snd_una)));
10000 
10001 	}
10002 }
10003 
10004 static void
10005 rack_adjust_sendmap(struct tcp_rack *rack, struct sockbuf *sb, tcp_seq snd_una)
10006 {
10007 	/*
10008 	 * Here any sendmap entry that points to the
10009 	 * beginning mbuf must be adjusted to the correct
10010 	 * offset. This must be called with:
10011 	 * 1) The socket buffer locked
10012 	 * 2) snd_una adjusted to its new postion.
10013 	 *
10014 	 * Note that (2) implies rack_ack_received has also
10015 	 * been called.
10016 	 *
10017 	 * We grab the first mbuf in the socket buffer and
10018 	 * then go through the front of the sendmap, recalculating
10019 	 * the stored offset for any sendmap entry that has
10020 	 * that mbuf. We must use the sb functions to do this
10021 	 * since its possible an add was done has well as
10022 	 * the subtraction we may have just completed. This should
10023 	 * not be a penalty though, since we just referenced the sb
10024 	 * to go in and trim off the mbufs that we freed (of course
10025 	 * there will be a penalty for the sendmap references though).
10026 	 */
10027 	struct mbuf *m;
10028 	struct rack_sendmap *rsm;
10029 
10030 	SOCKBUF_LOCK_ASSERT(sb);
10031 	m = sb->sb_mb;
10032 	rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
10033 	if ((rsm == NULL) || (m == NULL)) {
10034 		/* Nothing outstanding */
10035 		return;
10036 	}
10037 	while (rsm->m && (rsm->m == m)) {
10038 		/* one to adjust */
10039 #ifdef INVARIANTS
10040 		struct mbuf *tm;
10041 		uint32_t soff;
10042 
10043 		tm = sbsndmbuf(sb, (rsm->r_start - snd_una), &soff);
10044 		if (rsm->orig_m_len != m->m_len) {
10045 			rack_adjust_orig_mlen(rsm);
10046 		}
10047 		if (rsm->soff != soff) {
10048 			/*
10049 			 * This is not a fatal error, we anticipate it
10050 			 * might happen (the else code), so we count it here
10051 			 * so that under invariant we can see that it really
10052 			 * does happen.
10053 			 */
10054 			counter_u64_add(rack_adjust_map_bw, 1);
10055 		}
10056 		rsm->m = tm;
10057 		rsm->soff = soff;
10058 		if (tm)
10059 			rsm->orig_m_len = rsm->m->m_len;
10060 		else
10061 			rsm->orig_m_len = 0;
10062 #else
10063 		rsm->m = sbsndmbuf(sb, (rsm->r_start - snd_una), &rsm->soff);
10064 		if (rsm->m)
10065 			rsm->orig_m_len = rsm->m->m_len;
10066 		else
10067 			rsm->orig_m_len = 0;
10068 #endif
10069 		rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree,
10070 			      rsm);
10071 		if (rsm == NULL)
10072 			break;
10073 	}
10074 }
10075 
10076 /*
10077  * Return value of 1, we do not need to call rack_process_data().
10078  * return value of 0, rack_process_data can be called.
10079  * For ret_val if its 0 the TCP is locked, if its non-zero
10080  * its unlocked and probably unsafe to touch the TCB.
10081  */
10082 static int
10083 rack_process_ack(struct mbuf *m, struct tcphdr *th, struct socket *so,
10084     struct tcpcb *tp, struct tcpopt *to,
10085     uint32_t tiwin, int32_t tlen,
10086     int32_t * ofia, int32_t thflags, int32_t *ret_val)
10087 {
10088 	int32_t ourfinisacked = 0;
10089 	int32_t nsegs, acked_amount;
10090 	int32_t acked;
10091 	struct mbuf *mfree;
10092 	struct tcp_rack *rack;
10093 	int32_t under_pacing = 0;
10094 	int32_t recovery = 0;
10095 
10096 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10097 	if (SEQ_GT(th->th_ack, tp->snd_max)) {
10098 		__ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val,
10099 				      &rack->r_ctl.challenge_ack_ts,
10100 				      &rack->r_ctl.challenge_ack_cnt);
10101 		rack->r_wanted_output = 1;
10102 		return (1);
10103 	}
10104 	if (rack->gp_ready &&
10105 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
10106 		under_pacing = 1;
10107 	}
10108 	if (SEQ_GEQ(th->th_ack, tp->snd_una) || to->to_nsacks) {
10109 		int in_rec, dup_ack_struck = 0;
10110 
10111 		in_rec = IN_FASTRECOVERY(tp->t_flags);
10112 		if (rack->rc_in_persist) {
10113 			tp->t_rxtshift = 0;
10114 			RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
10115 				      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
10116 		}
10117 		if ((th->th_ack == tp->snd_una) &&
10118 		    (tiwin == tp->snd_wnd) &&
10119 		    ((to->to_flags & TOF_SACK) == 0)) {
10120 			rack_strike_dupack(rack);
10121 			dup_ack_struck = 1;
10122 		}
10123 		rack_log_ack(tp, to, th, ((in_rec == 0) && IN_FASTRECOVERY(tp->t_flags)), dup_ack_struck);
10124 	}
10125 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
10126 		/*
10127 		 * Old ack, behind (or duplicate to) the last one rcv'd
10128 		 * Note: We mark reordering is occuring if its
10129 		 * less than and we have not closed our window.
10130 		 */
10131 		if (SEQ_LT(th->th_ack, tp->snd_una) && (sbspace(&so->so_rcv) > ctf_fixed_maxseg(tp))) {
10132 			rack->r_ctl.rc_reorder_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
10133 		}
10134 		return (0);
10135 	}
10136 	/*
10137 	 * If we reach this point, ACK is not a duplicate, i.e., it ACKs
10138 	 * something we sent.
10139 	 */
10140 	if (tp->t_flags & TF_NEEDSYN) {
10141 		/*
10142 		 * T/TCP: Connection was half-synchronized, and our SYN has
10143 		 * been ACK'd (so connection is now fully synchronized).  Go
10144 		 * to non-starred state, increment snd_una for ACK of SYN,
10145 		 * and check if we can do window scaling.
10146 		 */
10147 		tp->t_flags &= ~TF_NEEDSYN;
10148 		tp->snd_una++;
10149 		/* Do window scaling? */
10150 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
10151 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
10152 			tp->rcv_scale = tp->request_r_scale;
10153 			/* Send window already scaled. */
10154 		}
10155 	}
10156 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
10157 	INP_WLOCK_ASSERT(tp->t_inpcb);
10158 
10159 	acked = BYTES_THIS_ACK(tp, th);
10160 	if (acked) {
10161 		/*
10162 		 * Any time we move the cum-ack forward clear
10163 		 * keep-alive tied probe-not-answered. The
10164 		 * persists clears its own on entry.
10165 		 */
10166 		rack->probe_not_answered = 0;
10167 	}
10168 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
10169 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
10170 	/*
10171 	 * If we just performed our first retransmit, and the ACK arrives
10172 	 * within our recovery window, then it was a mistake to do the
10173 	 * retransmit in the first place.  Recover our original cwnd and
10174 	 * ssthresh, and proceed to transmit where we left off.
10175 	 */
10176 	if ((tp->t_flags & TF_PREVVALID) &&
10177 	    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
10178 		tp->t_flags &= ~TF_PREVVALID;
10179 		if (tp->t_rxtshift == 1 &&
10180 		    (int)(ticks - tp->t_badrxtwin) < 0)
10181 			rack_cong_signal(tp, CC_RTO_ERR, th->th_ack, __LINE__);
10182 	}
10183 	if (acked) {
10184 		/* assure we are not backed off */
10185 		tp->t_rxtshift = 0;
10186 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
10187 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
10188 		rack->rc_tlp_in_progress = 0;
10189 		rack->r_ctl.rc_tlp_cnt_out = 0;
10190 		/*
10191 		 * If it is the RXT timer we want to
10192 		 * stop it, so we can restart a TLP.
10193 		 */
10194 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
10195 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
10196 #ifdef NETFLIX_HTTP_LOGGING
10197 		tcp_http_check_for_comp(rack->rc_tp, th->th_ack);
10198 #endif
10199 	}
10200 	/*
10201 	 * If we have a timestamp reply, update smoothed round trip time. If
10202 	 * no timestamp is present but transmit timer is running and timed
10203 	 * sequence number was acked, update smoothed round trip time. Since
10204 	 * we now have an rtt measurement, cancel the timer backoff (cf.,
10205 	 * Phil Karn's retransmit alg.). Recompute the initial retransmit
10206 	 * timer.
10207 	 *
10208 	 * Some boxes send broken timestamp replies during the SYN+ACK
10209 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
10210 	 * and blow up the retransmit timer.
10211 	 */
10212 	/*
10213 	 * If all outstanding data is acked, stop retransmit timer and
10214 	 * remember to restart (more output or persist). If there is more
10215 	 * data to be acked, restart retransmit timer, using current
10216 	 * (possibly backed-off) value.
10217 	 */
10218 	if (acked == 0) {
10219 		if (ofia)
10220 			*ofia = ourfinisacked;
10221 		return (0);
10222 	}
10223 	if (IN_RECOVERY(tp->t_flags)) {
10224 		if (SEQ_LT(th->th_ack, tp->snd_recover) &&
10225 		    (SEQ_LT(th->th_ack, tp->snd_max))) {
10226 			tcp_rack_partialack(tp);
10227 		} else {
10228 			rack_post_recovery(tp, th->th_ack);
10229 			recovery = 1;
10230 		}
10231 	}
10232 	/*
10233 	 * Let the congestion control algorithm update congestion control
10234 	 * related information. This typically means increasing the
10235 	 * congestion window.
10236 	 */
10237 	rack_ack_received(tp, rack, th->th_ack, nsegs, CC_ACK, recovery);
10238 	SOCKBUF_LOCK(&so->so_snd);
10239 	acked_amount = min(acked, (int)sbavail(&so->so_snd));
10240 	tp->snd_wnd -= acked_amount;
10241 	mfree = sbcut_locked(&so->so_snd, acked_amount);
10242 	if ((sbused(&so->so_snd) == 0) &&
10243 	    (acked > acked_amount) &&
10244 	    (tp->t_state >= TCPS_FIN_WAIT_1) &&
10245 	    (tp->t_flags & TF_SENTFIN)) {
10246 		/*
10247 		 * We must be sure our fin
10248 		 * was sent and acked (we can be
10249 		 * in FIN_WAIT_1 without having
10250 		 * sent the fin).
10251 		 */
10252 		ourfinisacked = 1;
10253 	}
10254 	tp->snd_una = th->th_ack;
10255 	if (acked_amount && sbavail(&so->so_snd))
10256 		rack_adjust_sendmap(rack, &so->so_snd, tp->snd_una);
10257 	rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
10258 	/* NB: sowwakeup_locked() does an implicit unlock. */
10259 	sowwakeup_locked(so);
10260 	m_freem(mfree);
10261 	if (SEQ_GT(tp->snd_una, tp->snd_recover))
10262 		tp->snd_recover = tp->snd_una;
10263 
10264 	if (SEQ_LT(tp->snd_nxt, tp->snd_una)) {
10265 		tp->snd_nxt = tp->snd_una;
10266 	}
10267 	if (under_pacing &&
10268 	    (rack->use_fixed_rate == 0) &&
10269 	    (rack->in_probe_rtt == 0) &&
10270 	    rack->rc_gp_dyn_mul &&
10271 	    rack->rc_always_pace) {
10272 		/* Check if we are dragging bottom */
10273 		rack_check_bottom_drag(tp, rack, so, acked);
10274 	}
10275 	if (tp->snd_una == tp->snd_max) {
10276 		/* Nothing left outstanding */
10277 		tp->t_flags &= ~TF_PREVVALID;
10278 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
10279 		rack->r_ctl.retran_during_recovery = 0;
10280 		rack->r_ctl.dsack_byte_cnt = 0;
10281 		if (rack->r_ctl.rc_went_idle_time == 0)
10282 			rack->r_ctl.rc_went_idle_time = 1;
10283 		rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
10284 		if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0)
10285 			tp->t_acktime = 0;
10286 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
10287 		/* Set need output so persist might get set */
10288 		rack->r_wanted_output = 1;
10289 		sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
10290 		if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
10291 		    (sbavail(&so->so_snd) == 0) &&
10292 		    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
10293 			/*
10294 			 * The socket was gone and the
10295 			 * peer sent data (now or in the past), time to
10296 			 * reset him.
10297 			 */
10298 			*ret_val = 1;
10299 			/* tcp_close will kill the inp pre-log the Reset */
10300 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
10301 			tp = tcp_close(tp);
10302 			ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, tlen);
10303 			return (1);
10304 		}
10305 	}
10306 	if (ofia)
10307 		*ofia = ourfinisacked;
10308 	return (0);
10309 }
10310 
10311 static void
10312 rack_collapsed_window(struct tcp_rack *rack)
10313 {
10314 	/*
10315 	 * Now we must walk the
10316 	 * send map and divide the
10317 	 * ones left stranded. These
10318 	 * guys can't cause us to abort
10319 	 * the connection and are really
10320 	 * "unsent". However if a buggy
10321 	 * client actually did keep some
10322 	 * of the data i.e. collapsed the win
10323 	 * and refused to ack and then opened
10324 	 * the win and acked that data. We would
10325 	 * get into an ack war, the simplier
10326 	 * method then of just pretending we
10327 	 * did not send those segments something
10328 	 * won't work.
10329 	 */
10330 	struct rack_sendmap *rsm, *nrsm, fe;
10331 #ifdef INVARIANTS
10332 	struct rack_sendmap *insret;
10333 #endif
10334 	tcp_seq max_seq;
10335 
10336 	rack_trace_point(rack, RACK_TP_COLLAPSED_WND);
10337 	max_seq = rack->rc_tp->snd_una + rack->rc_tp->snd_wnd;
10338 	memset(&fe, 0, sizeof(fe));
10339 	fe.r_start = max_seq;
10340 	/* Find the first seq past or at maxseq */
10341 	rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
10342 	if (rsm == NULL) {
10343 		/* Nothing to do strange */
10344 		rack->rc_has_collapsed = 0;
10345 		return;
10346 	}
10347 	/*
10348 	 * Now do we need to split at
10349 	 * the collapse point?
10350 	 */
10351 	if (SEQ_GT(max_seq, rsm->r_start)) {
10352 		nrsm = rack_alloc_limit(rack, RACK_LIMIT_TYPE_SPLIT);
10353 		if (nrsm == NULL) {
10354 			/* We can't get a rsm, mark all? */
10355 			nrsm = rsm;
10356 			goto no_split;
10357 		}
10358 		/* Clone it */
10359 		rack_clone_rsm(rack, nrsm, rsm, max_seq);
10360 #ifndef INVARIANTS
10361 		(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
10362 #else
10363 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm);
10364 		if (insret != NULL) {
10365 			panic("Insert in rb tree of %p fails ret:%p rack:%p rsm:%p",
10366 			      nrsm, insret, rack, rsm);
10367 		}
10368 #endif
10369 		rack_log_map_chg(rack->rc_tp, rack, NULL, rsm, nrsm, MAP_SPLIT, max_seq, __LINE__);
10370 		if (rsm->r_in_tmap) {
10371 			TAILQ_INSERT_AFTER(&rack->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
10372 			nrsm->r_in_tmap = 1;
10373 		}
10374 		/*
10375 		 * Set in the new RSM as the
10376 		 * collapsed starting point
10377 		 */
10378 		rsm = nrsm;
10379 	}
10380 no_split:
10381 	counter_u64_add(rack_collapsed_win, 1);
10382 	RB_FOREACH_FROM(nrsm, rack_rb_tree_head, rsm) {
10383 		nrsm->r_flags |= RACK_RWND_COLLAPSED;
10384 	}
10385 	rack->rc_has_collapsed = 1;
10386 }
10387 
10388 static void
10389 rack_un_collapse_window(struct tcp_rack *rack)
10390 {
10391 	struct rack_sendmap *rsm;
10392 	int cnt = 0;;
10393 
10394 	rack->r_ctl.rc_out_at_rto = 0;
10395 	rack->r_ctl.rc_snd_max_at_rto = rack->rc_tp->snd_una;
10396 	RB_FOREACH_REVERSE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
10397 		if (rsm->r_flags & RACK_RWND_COLLAPSED) {
10398 			rsm->r_flags &= ~RACK_RWND_COLLAPSED;
10399 			rsm->r_flags |= RACK_MUST_RXT;
10400 			if (SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) {
10401 				rack->r_ctl.rc_snd_max_at_rto = rsm->r_end;
10402 				rack->r_ctl.rc_out_at_rto += (rsm->r_end - rsm->r_start);
10403 			}
10404 			cnt++;
10405 		}
10406 		else
10407 			break;
10408 	}
10409 	rack->rc_has_collapsed = 0;
10410 	if (cnt) {
10411 		rack->r_must_retran = 1;
10412 	}
10413 }
10414 
10415 static void
10416 rack_handle_delayed_ack(struct tcpcb *tp, struct tcp_rack *rack,
10417 			int32_t tlen, int32_t tfo_syn)
10418 {
10419 	if (DELAY_ACK(tp, tlen) || tfo_syn) {
10420 		if (rack->rc_dack_mode &&
10421 		    (tlen > 500) &&
10422 		    (rack->rc_dack_toggle == 1)) {
10423 			goto no_delayed_ack;
10424 		}
10425 		rack_timer_cancel(tp, rack,
10426 				  rack->r_ctl.rc_rcvtime, __LINE__);
10427 		tp->t_flags |= TF_DELACK;
10428 	} else {
10429 no_delayed_ack:
10430 		rack->r_wanted_output = 1;
10431 		tp->t_flags |= TF_ACKNOW;
10432 		if (rack->rc_dack_mode) {
10433 			if (tp->t_flags & TF_DELACK)
10434 				rack->rc_dack_toggle = 1;
10435 			else
10436 				rack->rc_dack_toggle = 0;
10437 		}
10438 	}
10439 }
10440 
10441 static void
10442 rack_validate_fo_sendwin_up(struct tcpcb *tp, struct tcp_rack *rack)
10443 {
10444 	/*
10445 	 * If fast output is in progress, lets validate that
10446 	 * the new window did not shrink on us and make it
10447 	 * so fast output should end.
10448 	 */
10449 	if (rack->r_fast_output) {
10450 		uint32_t out;
10451 
10452 		/*
10453 		 * Calculate what we will send if left as is
10454 		 * and compare that to our send window.
10455 		 */
10456 		out = ctf_outstanding(tp);
10457 		if ((out + rack->r_ctl.fsb.left_to_send) > tp->snd_wnd) {
10458 			/* ok we have an issue */
10459 			if (out >= tp->snd_wnd) {
10460 				/* Turn off fast output the window is met or collapsed */
10461 				rack->r_fast_output = 0;
10462 			} else {
10463 				/* we have some room left */
10464 				rack->r_ctl.fsb.left_to_send = tp->snd_wnd - out;
10465 				if (rack->r_ctl.fsb.left_to_send < ctf_fixed_maxseg(tp)) {
10466 					/* If not at least 1 full segment never mind */
10467 					rack->r_fast_output = 0;
10468 				}
10469 			}
10470 		}
10471 	}
10472 }
10473 
10474 
10475 /*
10476  * Return value of 1, the TCB is unlocked and most
10477  * likely gone, return value of 0, the TCP is still
10478  * locked.
10479  */
10480 static int
10481 rack_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so,
10482     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
10483     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
10484 {
10485 	/*
10486 	 * Update window information. Don't look at window if no ACK: TAC's
10487 	 * send garbage on first SYN.
10488 	 */
10489 	int32_t nsegs;
10490 	int32_t tfo_syn;
10491 	struct tcp_rack *rack;
10492 
10493 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10494 	INP_WLOCK_ASSERT(tp->t_inpcb);
10495 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
10496 	if ((thflags & TH_ACK) &&
10497 	    (SEQ_LT(tp->snd_wl1, th->th_seq) ||
10498 	    (tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) ||
10499 	    (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) {
10500 		/* keep track of pure window updates */
10501 		if (tlen == 0 &&
10502 		    tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd)
10503 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
10504 		tp->snd_wnd = tiwin;
10505 		rack_validate_fo_sendwin_up(tp, rack);
10506 		tp->snd_wl1 = th->th_seq;
10507 		tp->snd_wl2 = th->th_ack;
10508 		if (tp->snd_wnd > tp->max_sndwnd)
10509 			tp->max_sndwnd = tp->snd_wnd;
10510 		rack->r_wanted_output = 1;
10511 	} else if (thflags & TH_ACK) {
10512 		if ((tp->snd_wl2 == th->th_ack) && (tiwin < tp->snd_wnd)) {
10513 			tp->snd_wnd = tiwin;
10514 			rack_validate_fo_sendwin_up(tp, rack);
10515 			tp->snd_wl1 = th->th_seq;
10516 			tp->snd_wl2 = th->th_ack;
10517 		}
10518 	}
10519 	if (tp->snd_wnd < ctf_outstanding(tp))
10520 		/* The peer collapsed the window */
10521 		rack_collapsed_window(rack);
10522 	else if (rack->rc_has_collapsed)
10523 		rack_un_collapse_window(rack);
10524 	/* Was persist timer active and now we have window space? */
10525 	if ((rack->rc_in_persist != 0) &&
10526 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
10527 				rack->r_ctl.rc_pace_min_segs))) {
10528 		rack_exit_persist(tp, rack, rack->r_ctl.rc_rcvtime);
10529 		tp->snd_nxt = tp->snd_max;
10530 		/* Make sure we output to start the timer */
10531 		rack->r_wanted_output = 1;
10532 	}
10533 	/* Do we enter persists? */
10534 	if ((rack->rc_in_persist == 0) &&
10535 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
10536 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
10537 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
10538 	    sbavail(&tp->t_inpcb->inp_socket->so_snd) &&
10539 	    (sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) {
10540 		/*
10541 		 * Here the rwnd is less than
10542 		 * the pacing size, we are established,
10543 		 * nothing is outstanding, and there is
10544 		 * data to send. Enter persists.
10545 		 */
10546 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
10547 	}
10548 	if (tp->t_flags2 & TF2_DROP_AF_DATA) {
10549 		m_freem(m);
10550 		return (0);
10551 	}
10552 	/*
10553 	 * don't process the URG bit, ignore them drag
10554 	 * along the up.
10555 	 */
10556 	tp->rcv_up = tp->rcv_nxt;
10557 	INP_WLOCK_ASSERT(tp->t_inpcb);
10558 
10559 	/*
10560 	 * Process the segment text, merging it into the TCP sequencing
10561 	 * queue, and arranging for acknowledgment of receipt if necessary.
10562 	 * This process logically involves adjusting tp->rcv_wnd as data is
10563 	 * presented to the user (this happens in tcp_usrreq.c, case
10564 	 * PRU_RCVD).  If a FIN has already been received on this connection
10565 	 * then we just ignore the text.
10566 	 */
10567 	tfo_syn = ((tp->t_state == TCPS_SYN_RECEIVED) &&
10568 		   IS_FASTOPEN(tp->t_flags));
10569 	if ((tlen || (thflags & TH_FIN) || (tfo_syn && tlen > 0)) &&
10570 	    TCPS_HAVERCVDFIN(tp->t_state) == 0) {
10571 		tcp_seq save_start = th->th_seq;
10572 		tcp_seq save_rnxt  = tp->rcv_nxt;
10573 		int     save_tlen  = tlen;
10574 
10575 		m_adj(m, drop_hdrlen);	/* delayed header drop */
10576 		/*
10577 		 * Insert segment which includes th into TCP reassembly
10578 		 * queue with control block tp.  Set thflags to whether
10579 		 * reassembly now includes a segment with FIN.  This handles
10580 		 * the common case inline (segment is the next to be
10581 		 * received on an established connection, and the queue is
10582 		 * empty), avoiding linkage into and removal from the queue
10583 		 * and repetition of various conversions. Set DELACK for
10584 		 * segments received in order, but ack immediately when
10585 		 * segments are out of order (so fast retransmit can work).
10586 		 */
10587 		if (th->th_seq == tp->rcv_nxt &&
10588 		    SEGQ_EMPTY(tp) &&
10589 		    (TCPS_HAVEESTABLISHED(tp->t_state) ||
10590 		    tfo_syn)) {
10591 #ifdef NETFLIX_SB_LIMITS
10592 			u_int mcnt, appended;
10593 
10594 			if (so->so_rcv.sb_shlim) {
10595 				mcnt = m_memcnt(m);
10596 				appended = 0;
10597 				if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
10598 				    CFO_NOSLEEP, NULL) == false) {
10599 					counter_u64_add(tcp_sb_shlim_fails, 1);
10600 					m_freem(m);
10601 					return (0);
10602 				}
10603 			}
10604 #endif
10605 			rack_handle_delayed_ack(tp, rack, tlen, tfo_syn);
10606 			tp->rcv_nxt += tlen;
10607 			if (tlen &&
10608 			    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
10609 			    (tp->t_fbyte_in == 0)) {
10610 				tp->t_fbyte_in = ticks;
10611 				if (tp->t_fbyte_in == 0)
10612 					tp->t_fbyte_in = 1;
10613 				if (tp->t_fbyte_out && tp->t_fbyte_in)
10614 					tp->t_flags2 |= TF2_FBYTES_COMPLETE;
10615 			}
10616 			thflags = tcp_get_flags(th) & TH_FIN;
10617 			KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
10618 			KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
10619 			SOCKBUF_LOCK(&so->so_rcv);
10620 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
10621 				m_freem(m);
10622 			} else
10623 #ifdef NETFLIX_SB_LIMITS
10624 				appended =
10625 #endif
10626 					sbappendstream_locked(&so->so_rcv, m, 0);
10627 
10628 			rack_log_wakeup(tp,rack, &so->so_rcv, tlen, 1);
10629 			/* NB: sorwakeup_locked() does an implicit unlock. */
10630 			sorwakeup_locked(so);
10631 #ifdef NETFLIX_SB_LIMITS
10632 			if (so->so_rcv.sb_shlim && appended != mcnt)
10633 				counter_fo_release(so->so_rcv.sb_shlim,
10634 				    mcnt - appended);
10635 #endif
10636 		} else {
10637 			/*
10638 			 * XXX: Due to the header drop above "th" is
10639 			 * theoretically invalid by now.  Fortunately
10640 			 * m_adj() doesn't actually frees any mbufs when
10641 			 * trimming from the head.
10642 			 */
10643 			tcp_seq temp = save_start;
10644 
10645 			thflags = tcp_reass(tp, th, &temp, &tlen, m);
10646 			tp->t_flags |= TF_ACKNOW;
10647 			if (tp->t_flags & TF_WAKESOR) {
10648 				tp->t_flags &= ~TF_WAKESOR;
10649 				/* NB: sorwakeup_locked() does an implicit unlock. */
10650 				sorwakeup_locked(so);
10651 			}
10652 		}
10653 		if ((tp->t_flags & TF_SACK_PERMIT) &&
10654 		    (save_tlen > 0) &&
10655 		    TCPS_HAVEESTABLISHED(tp->t_state)) {
10656 			if ((tlen == 0) && (SEQ_LT(save_start, save_rnxt))) {
10657 				/*
10658 				 * DSACK actually handled in the fastpath
10659 				 * above.
10660 				 */
10661 				RACK_OPTS_INC(tcp_sack_path_1);
10662 				tcp_update_sack_list(tp, save_start,
10663 				    save_start + save_tlen);
10664 			} else if ((tlen > 0) && SEQ_GT(tp->rcv_nxt, save_rnxt)) {
10665 				if ((tp->rcv_numsacks >= 1) &&
10666 				    (tp->sackblks[0].end == save_start)) {
10667 					/*
10668 					 * Partial overlap, recorded at todrop
10669 					 * above.
10670 					 */
10671 					RACK_OPTS_INC(tcp_sack_path_2a);
10672 					tcp_update_sack_list(tp,
10673 					    tp->sackblks[0].start,
10674 					    tp->sackblks[0].end);
10675 				} else {
10676 					RACK_OPTS_INC(tcp_sack_path_2b);
10677 					tcp_update_dsack_list(tp, save_start,
10678 					    save_start + save_tlen);
10679 				}
10680 			} else if (tlen >= save_tlen) {
10681 				/* Update of sackblks. */
10682 				RACK_OPTS_INC(tcp_sack_path_3);
10683 				tcp_update_dsack_list(tp, save_start,
10684 				    save_start + save_tlen);
10685 			} else if (tlen > 0) {
10686 				RACK_OPTS_INC(tcp_sack_path_4);
10687 				tcp_update_dsack_list(tp, save_start,
10688 				    save_start + tlen);
10689 			}
10690 		}
10691 	} else {
10692 		m_freem(m);
10693 		thflags &= ~TH_FIN;
10694 	}
10695 
10696 	/*
10697 	 * If FIN is received ACK the FIN and let the user know that the
10698 	 * connection is closing.
10699 	 */
10700 	if (thflags & TH_FIN) {
10701 		if (TCPS_HAVERCVDFIN(tp->t_state) == 0) {
10702 			/* The socket upcall is handled by socantrcvmore. */
10703 			socantrcvmore(so);
10704 			/*
10705 			 * If connection is half-synchronized (ie NEEDSYN
10706 			 * flag on) then delay ACK, so it may be piggybacked
10707 			 * when SYN is sent. Otherwise, since we received a
10708 			 * FIN then no more input can be expected, send ACK
10709 			 * now.
10710 			 */
10711 			if (tp->t_flags & TF_NEEDSYN) {
10712 				rack_timer_cancel(tp, rack,
10713 				    rack->r_ctl.rc_rcvtime, __LINE__);
10714 				tp->t_flags |= TF_DELACK;
10715 			} else {
10716 				tp->t_flags |= TF_ACKNOW;
10717 			}
10718 			tp->rcv_nxt++;
10719 		}
10720 		switch (tp->t_state) {
10721 			/*
10722 			 * In SYN_RECEIVED and ESTABLISHED STATES enter the
10723 			 * CLOSE_WAIT state.
10724 			 */
10725 		case TCPS_SYN_RECEIVED:
10726 			tp->t_starttime = ticks;
10727 			/* FALLTHROUGH */
10728 		case TCPS_ESTABLISHED:
10729 			rack_timer_cancel(tp, rack,
10730 			    rack->r_ctl.rc_rcvtime, __LINE__);
10731 			tcp_state_change(tp, TCPS_CLOSE_WAIT);
10732 			break;
10733 
10734 			/*
10735 			 * If still in FIN_WAIT_1 STATE FIN has not been
10736 			 * acked so enter the CLOSING state.
10737 			 */
10738 		case TCPS_FIN_WAIT_1:
10739 			rack_timer_cancel(tp, rack,
10740 			    rack->r_ctl.rc_rcvtime, __LINE__);
10741 			tcp_state_change(tp, TCPS_CLOSING);
10742 			break;
10743 
10744 			/*
10745 			 * In FIN_WAIT_2 state enter the TIME_WAIT state,
10746 			 * starting the time-wait timer, turning off the
10747 			 * other standard timers.
10748 			 */
10749 		case TCPS_FIN_WAIT_2:
10750 			rack_timer_cancel(tp, rack,
10751 			    rack->r_ctl.rc_rcvtime, __LINE__);
10752 			tcp_twstart(tp);
10753 			return (1);
10754 		}
10755 	}
10756 	/*
10757 	 * Return any desired output.
10758 	 */
10759 	if ((tp->t_flags & TF_ACKNOW) ||
10760 	    (sbavail(&so->so_snd) > (tp->snd_max - tp->snd_una))) {
10761 		rack->r_wanted_output = 1;
10762 	}
10763 	INP_WLOCK_ASSERT(tp->t_inpcb);
10764 	return (0);
10765 }
10766 
10767 /*
10768  * Here nothing is really faster, its just that we
10769  * have broken out the fast-data path also just like
10770  * the fast-ack.
10771  */
10772 static int
10773 rack_do_fastnewdata(struct mbuf *m, struct tcphdr *th, struct socket *so,
10774     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
10775     uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos)
10776 {
10777 	int32_t nsegs;
10778 	int32_t newsize = 0;	/* automatic sockbuf scaling */
10779 	struct tcp_rack *rack;
10780 #ifdef NETFLIX_SB_LIMITS
10781 	u_int mcnt, appended;
10782 #endif
10783 #ifdef TCPDEBUG
10784 	/*
10785 	 * The size of tcp_saveipgen must be the size of the max ip header,
10786 	 * now IPv6.
10787 	 */
10788 	u_char tcp_saveipgen[IP6_HDR_LEN];
10789 	struct tcphdr tcp_savetcp;
10790 	short ostate = 0;
10791 
10792 #endif
10793 	/*
10794 	 * If last ACK falls within this segment's sequence numbers, record
10795 	 * the timestamp. NOTE that the test is modified according to the
10796 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
10797 	 */
10798 	if (__predict_false(th->th_seq != tp->rcv_nxt)) {
10799 		return (0);
10800 	}
10801 	if (__predict_false(tp->snd_nxt != tp->snd_max)) {
10802 		return (0);
10803 	}
10804 	if (tiwin && tiwin != tp->snd_wnd) {
10805 		return (0);
10806 	}
10807 	if (__predict_false((tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN)))) {
10808 		return (0);
10809 	}
10810 	if (__predict_false((to->to_flags & TOF_TS) &&
10811 	    (TSTMP_LT(to->to_tsval, tp->ts_recent)))) {
10812 		return (0);
10813 	}
10814 	if (__predict_false((th->th_ack != tp->snd_una))) {
10815 		return (0);
10816 	}
10817 	if (__predict_false(tlen > sbspace(&so->so_rcv))) {
10818 		return (0);
10819 	}
10820 	if ((to->to_flags & TOF_TS) != 0 &&
10821 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
10822 		tp->ts_recent_age = tcp_ts_getticks();
10823 		tp->ts_recent = to->to_tsval;
10824 	}
10825 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10826 	/*
10827 	 * This is a pure, in-sequence data packet with nothing on the
10828 	 * reassembly queue and we have enough buffer space to take it.
10829 	 */
10830 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
10831 
10832 #ifdef NETFLIX_SB_LIMITS
10833 	if (so->so_rcv.sb_shlim) {
10834 		mcnt = m_memcnt(m);
10835 		appended = 0;
10836 		if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
10837 		    CFO_NOSLEEP, NULL) == false) {
10838 			counter_u64_add(tcp_sb_shlim_fails, 1);
10839 			m_freem(m);
10840 			return (1);
10841 		}
10842 	}
10843 #endif
10844 	/* Clean receiver SACK report if present */
10845 	if (tp->rcv_numsacks)
10846 		tcp_clean_sackreport(tp);
10847 	KMOD_TCPSTAT_INC(tcps_preddat);
10848 	tp->rcv_nxt += tlen;
10849 	if (tlen &&
10850 	    ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
10851 	    (tp->t_fbyte_in == 0)) {
10852 		tp->t_fbyte_in = ticks;
10853 		if (tp->t_fbyte_in == 0)
10854 			tp->t_fbyte_in = 1;
10855 		if (tp->t_fbyte_out && tp->t_fbyte_in)
10856 			tp->t_flags2 |= TF2_FBYTES_COMPLETE;
10857 	}
10858 	/*
10859 	 * Pull snd_wl1 up to prevent seq wrap relative to th_seq.
10860 	 */
10861 	tp->snd_wl1 = th->th_seq;
10862 	/*
10863 	 * Pull rcv_up up to prevent seq wrap relative to rcv_nxt.
10864 	 */
10865 	tp->rcv_up = tp->rcv_nxt;
10866 	KMOD_TCPSTAT_ADD(tcps_rcvpack, nsegs);
10867 	KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
10868 #ifdef TCPDEBUG
10869 	if (so->so_options & SO_DEBUG)
10870 		tcp_trace(TA_INPUT, ostate, tp,
10871 		    (void *)tcp_saveipgen, &tcp_savetcp, 0);
10872 #endif
10873 	newsize = tcp_autorcvbuf(m, th, so, tp, tlen);
10874 
10875 	/* Add data to socket buffer. */
10876 	SOCKBUF_LOCK(&so->so_rcv);
10877 	if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
10878 		m_freem(m);
10879 	} else {
10880 		/*
10881 		 * Set new socket buffer size. Give up when limit is
10882 		 * reached.
10883 		 */
10884 		if (newsize)
10885 			if (!sbreserve_locked(so, SO_RCV, newsize, NULL))
10886 				so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
10887 		m_adj(m, drop_hdrlen);	/* delayed header drop */
10888 #ifdef NETFLIX_SB_LIMITS
10889 		appended =
10890 #endif
10891 			sbappendstream_locked(&so->so_rcv, m, 0);
10892 		ctf_calc_rwin(so, tp);
10893 	}
10894 	rack_log_wakeup(tp,rack, &so->so_rcv, tlen, 1);
10895 	/* NB: sorwakeup_locked() does an implicit unlock. */
10896 	sorwakeup_locked(so);
10897 #ifdef NETFLIX_SB_LIMITS
10898 	if (so->so_rcv.sb_shlim && mcnt != appended)
10899 		counter_fo_release(so->so_rcv.sb_shlim, mcnt - appended);
10900 #endif
10901 	rack_handle_delayed_ack(tp, rack, tlen, 0);
10902 	if (tp->snd_una == tp->snd_max)
10903 		sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
10904 	return (1);
10905 }
10906 
10907 /*
10908  * This subfunction is used to try to highly optimize the
10909  * fast path. We again allow window updates that are
10910  * in sequence to remain in the fast-path. We also add
10911  * in the __predict's to attempt to help the compiler.
10912  * Note that if we return a 0, then we can *not* process
10913  * it and the caller should push the packet into the
10914  * slow-path.
10915  */
10916 static int
10917 rack_fastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
10918     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
10919     uint32_t tiwin, int32_t nxt_pkt, uint32_t cts)
10920 {
10921 	int32_t acked;
10922 	int32_t nsegs;
10923 #ifdef TCPDEBUG
10924 	/*
10925 	 * The size of tcp_saveipgen must be the size of the max ip header,
10926 	 * now IPv6.
10927 	 */
10928 	u_char tcp_saveipgen[IP6_HDR_LEN];
10929 	struct tcphdr tcp_savetcp;
10930 	short ostate = 0;
10931 #endif
10932 	int32_t under_pacing = 0;
10933 	struct tcp_rack *rack;
10934 
10935 	if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
10936 		/* Old ack, behind (or duplicate to) the last one rcv'd */
10937 		return (0);
10938 	}
10939 	if (__predict_false(SEQ_GT(th->th_ack, tp->snd_max))) {
10940 		/* Above what we have sent? */
10941 		return (0);
10942 	}
10943 	if (__predict_false(tp->snd_nxt != tp->snd_max)) {
10944 		/* We are retransmitting */
10945 		return (0);
10946 	}
10947 	if (__predict_false(tiwin == 0)) {
10948 		/* zero window */
10949 		return (0);
10950 	}
10951 	if (__predict_false(tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN))) {
10952 		/* We need a SYN or a FIN, unlikely.. */
10953 		return (0);
10954 	}
10955 	if ((to->to_flags & TOF_TS) && __predict_false(TSTMP_LT(to->to_tsval, tp->ts_recent))) {
10956 		/* Timestamp is behind .. old ack with seq wrap? */
10957 		return (0);
10958 	}
10959 	if (__predict_false(IN_RECOVERY(tp->t_flags))) {
10960 		/* Still recovering */
10961 		return (0);
10962 	}
10963 	rack = (struct tcp_rack *)tp->t_fb_ptr;
10964 	if (rack->r_ctl.rc_sacked) {
10965 		/* We have sack holes on our scoreboard */
10966 		return (0);
10967 	}
10968 	/* Ok if we reach here, we can process a fast-ack */
10969 	if (rack->gp_ready &&
10970 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
10971 		under_pacing = 1;
10972 	}
10973 	nsegs = max(1, m->m_pkthdr.lro_nsegs);
10974 	rack_log_ack(tp, to, th, 0, 0);
10975 	/* Did the window get updated? */
10976 	if (tiwin != tp->snd_wnd) {
10977 		tp->snd_wnd = tiwin;
10978 		rack_validate_fo_sendwin_up(tp, rack);
10979 		tp->snd_wl1 = th->th_seq;
10980 		if (tp->snd_wnd > tp->max_sndwnd)
10981 			tp->max_sndwnd = tp->snd_wnd;
10982 	}
10983 	/* Do we exit persists? */
10984 	if ((rack->rc_in_persist != 0) &&
10985 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
10986 			       rack->r_ctl.rc_pace_min_segs))) {
10987 		rack_exit_persist(tp, rack, cts);
10988 	}
10989 	/* Do we enter persists? */
10990 	if ((rack->rc_in_persist == 0) &&
10991 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
10992 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
10993 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
10994 	    sbavail(&tp->t_inpcb->inp_socket->so_snd) &&
10995 	    (sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) {
10996 		/*
10997 		 * Here the rwnd is less than
10998 		 * the pacing size, we are established,
10999 		 * nothing is outstanding, and there is
11000 		 * data to send. Enter persists.
11001 		 */
11002 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
11003 	}
11004 	/*
11005 	 * If last ACK falls within this segment's sequence numbers, record
11006 	 * the timestamp. NOTE that the test is modified according to the
11007 	 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
11008 	 */
11009 	if ((to->to_flags & TOF_TS) != 0 &&
11010 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
11011 		tp->ts_recent_age = tcp_ts_getticks();
11012 		tp->ts_recent = to->to_tsval;
11013 	}
11014 	/*
11015 	 * This is a pure ack for outstanding data.
11016 	 */
11017 	KMOD_TCPSTAT_INC(tcps_predack);
11018 
11019 	/*
11020 	 * "bad retransmit" recovery.
11021 	 */
11022 	if ((tp->t_flags & TF_PREVVALID) &&
11023 	    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
11024 		tp->t_flags &= ~TF_PREVVALID;
11025 		if (tp->t_rxtshift == 1 &&
11026 		    (int)(ticks - tp->t_badrxtwin) < 0)
11027 			rack_cong_signal(tp, CC_RTO_ERR, th->th_ack, __LINE__);
11028 	}
11029 	/*
11030 	 * Recalculate the transmit timer / rtt.
11031 	 *
11032 	 * Some boxes send broken timestamp replies during the SYN+ACK
11033 	 * phase, ignore timestamps of 0 or we could calculate a huge RTT
11034 	 * and blow up the retransmit timer.
11035 	 */
11036 	acked = BYTES_THIS_ACK(tp, th);
11037 
11038 #ifdef TCP_HHOOK
11039 	/* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */
11040 	hhook_run_tcp_est_in(tp, th, to);
11041 #endif
11042 	KMOD_TCPSTAT_ADD(tcps_rcvackpack, nsegs);
11043 	KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
11044 	if (acked) {
11045 		struct mbuf *mfree;
11046 
11047 		rack_ack_received(tp, rack, th->th_ack, nsegs, CC_ACK, 0);
11048 		SOCKBUF_LOCK(&so->so_snd);
11049 		mfree = sbcut_locked(&so->so_snd, acked);
11050 		tp->snd_una = th->th_ack;
11051 		/* Note we want to hold the sb lock through the sendmap adjust */
11052 		rack_adjust_sendmap(rack, &so->so_snd, tp->snd_una);
11053 		/* Wake up the socket if we have room to write more */
11054 		rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
11055 		sowwakeup_locked(so);
11056 		m_freem(mfree);
11057 		tp->t_rxtshift = 0;
11058 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
11059 			      rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
11060 		rack->rc_tlp_in_progress = 0;
11061 		rack->r_ctl.rc_tlp_cnt_out = 0;
11062 		/*
11063 		 * If it is the RXT timer we want to
11064 		 * stop it, so we can restart a TLP.
11065 		 */
11066 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
11067 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
11068 #ifdef NETFLIX_HTTP_LOGGING
11069 		tcp_http_check_for_comp(rack->rc_tp, th->th_ack);
11070 #endif
11071 	}
11072 	/*
11073 	 * Let the congestion control algorithm update congestion control
11074 	 * related information. This typically means increasing the
11075 	 * congestion window.
11076 	 */
11077 	if (tp->snd_wnd < ctf_outstanding(tp)) {
11078 		/* The peer collapsed the window */
11079 		rack_collapsed_window(rack);
11080 	} else if (rack->rc_has_collapsed)
11081 		rack_un_collapse_window(rack);
11082 
11083 	/*
11084 	 * Pull snd_wl2 up to prevent seq wrap relative to th_ack.
11085 	 */
11086 	tp->snd_wl2 = th->th_ack;
11087 	tp->t_dupacks = 0;
11088 	m_freem(m);
11089 	/* ND6_HINT(tp);	 *//* Some progress has been made. */
11090 
11091 	/*
11092 	 * If all outstanding data are acked, stop retransmit timer,
11093 	 * otherwise restart timer using current (possibly backed-off)
11094 	 * value. If process is waiting for space, wakeup/selwakeup/signal.
11095 	 * If data are ready to send, let tcp_output decide between more
11096 	 * output or persist.
11097 	 */
11098 #ifdef TCPDEBUG
11099 	if (so->so_options & SO_DEBUG)
11100 		tcp_trace(TA_INPUT, ostate, tp,
11101 		    (void *)tcp_saveipgen,
11102 		    &tcp_savetcp, 0);
11103 #endif
11104 	if (under_pacing &&
11105 	    (rack->use_fixed_rate == 0) &&
11106 	    (rack->in_probe_rtt == 0) &&
11107 	    rack->rc_gp_dyn_mul &&
11108 	    rack->rc_always_pace) {
11109 		/* Check if we are dragging bottom */
11110 		rack_check_bottom_drag(tp, rack, so, acked);
11111 	}
11112 	if (tp->snd_una == tp->snd_max) {
11113 		tp->t_flags &= ~TF_PREVVALID;
11114 		rack->r_ctl.retran_during_recovery = 0;
11115 		rack->r_ctl.dsack_byte_cnt = 0;
11116 		rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
11117 		if (rack->r_ctl.rc_went_idle_time == 0)
11118 			rack->r_ctl.rc_went_idle_time = 1;
11119 		rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
11120 		if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0)
11121 			tp->t_acktime = 0;
11122 		rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
11123 	}
11124 	if (acked && rack->r_fast_output)
11125 		rack_gain_for_fastoutput(rack, tp, so, (uint32_t)acked);
11126 	if (sbavail(&so->so_snd)) {
11127 		rack->r_wanted_output = 1;
11128 	}
11129 	return (1);
11130 }
11131 
11132 /*
11133  * Return value of 1, the TCB is unlocked and most
11134  * likely gone, return value of 0, the TCP is still
11135  * locked.
11136  */
11137 static int
11138 rack_do_syn_sent(struct mbuf *m, struct tcphdr *th, struct socket *so,
11139     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11140     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11141 {
11142 	int32_t ret_val = 0;
11143 	int32_t todrop;
11144 	int32_t ourfinisacked = 0;
11145 	struct tcp_rack *rack;
11146 
11147 	ctf_calc_rwin(so, tp);
11148 	/*
11149 	 * If the state is SYN_SENT: if seg contains an ACK, but not for our
11150 	 * SYN, drop the input. if seg contains a RST, then drop the
11151 	 * connection. if seg does not contain SYN, then drop it. Otherwise
11152 	 * this is an acceptable SYN segment initialize tp->rcv_nxt and
11153 	 * tp->irs if seg contains ack then advance tp->snd_una if seg
11154 	 * contains an ECE and ECN support is enabled, the stream is ECN
11155 	 * capable. if SYN has been acked change to ESTABLISHED else
11156 	 * SYN_RCVD state arrange for segment to be acked (eventually)
11157 	 * continue processing rest of data/controls.
11158 	 */
11159 	if ((thflags & TH_ACK) &&
11160 	    (SEQ_LEQ(th->th_ack, tp->iss) ||
11161 	    SEQ_GT(th->th_ack, tp->snd_max))) {
11162 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11163 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11164 		return (1);
11165 	}
11166 	if ((thflags & (TH_ACK | TH_RST)) == (TH_ACK | TH_RST)) {
11167 		TCP_PROBE5(connect__refused, NULL, tp,
11168 		    mtod(m, const char *), tp, th);
11169 		tp = tcp_drop(tp, ECONNREFUSED);
11170 		ctf_do_drop(m, tp);
11171 		return (1);
11172 	}
11173 	if (thflags & TH_RST) {
11174 		ctf_do_drop(m, tp);
11175 		return (1);
11176 	}
11177 	if (!(thflags & TH_SYN)) {
11178 		ctf_do_drop(m, tp);
11179 		return (1);
11180 	}
11181 	tp->irs = th->th_seq;
11182 	tcp_rcvseqinit(tp);
11183 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11184 	if (thflags & TH_ACK) {
11185 		int tfo_partial = 0;
11186 
11187 		KMOD_TCPSTAT_INC(tcps_connects);
11188 		soisconnected(so);
11189 #ifdef MAC
11190 		mac_socketpeer_set_from_mbuf(m, so);
11191 #endif
11192 		/* Do window scaling on this connection? */
11193 		if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
11194 		    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
11195 			tp->rcv_scale = tp->request_r_scale;
11196 		}
11197 		tp->rcv_adv += min(tp->rcv_wnd,
11198 		    TCP_MAXWIN << tp->rcv_scale);
11199 		/*
11200 		 * If not all the data that was sent in the TFO SYN
11201 		 * has been acked, resend the remainder right away.
11202 		 */
11203 		if (IS_FASTOPEN(tp->t_flags) &&
11204 		    (tp->snd_una != tp->snd_max)) {
11205 			tp->snd_nxt = th->th_ack;
11206 			tfo_partial = 1;
11207 		}
11208 		/*
11209 		 * If there's data, delay ACK; if there's also a FIN ACKNOW
11210 		 * will be turned on later.
11211 		 */
11212 		if (DELAY_ACK(tp, tlen) && tlen != 0 && !tfo_partial) {
11213 			rack_timer_cancel(tp, rack,
11214 					  rack->r_ctl.rc_rcvtime, __LINE__);
11215 			tp->t_flags |= TF_DELACK;
11216 		} else {
11217 			rack->r_wanted_output = 1;
11218 			tp->t_flags |= TF_ACKNOW;
11219 			rack->rc_dack_toggle = 0;
11220 		}
11221 
11222 		tcp_ecn_input_syn_sent(tp, thflags, iptos);
11223 
11224 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
11225 			/*
11226 			 * We advance snd_una for the
11227 			 * fast open case. If th_ack is
11228 			 * acknowledging data beyond
11229 			 * snd_una we can't just call
11230 			 * ack-processing since the
11231 			 * data stream in our send-map
11232 			 * will start at snd_una + 1 (one
11233 			 * beyond the SYN). If its just
11234 			 * equal we don't need to do that
11235 			 * and there is no send_map.
11236 			 */
11237 			tp->snd_una++;
11238 		}
11239 		/*
11240 		 * Received <SYN,ACK> in SYN_SENT[*] state. Transitions:
11241 		 * SYN_SENT  --> ESTABLISHED SYN_SENT* --> FIN_WAIT_1
11242 		 */
11243 		tp->t_starttime = ticks;
11244 		if (tp->t_flags & TF_NEEDFIN) {
11245 			tcp_state_change(tp, TCPS_FIN_WAIT_1);
11246 			tp->t_flags &= ~TF_NEEDFIN;
11247 			thflags &= ~TH_SYN;
11248 		} else {
11249 			tcp_state_change(tp, TCPS_ESTABLISHED);
11250 			TCP_PROBE5(connect__established, NULL, tp,
11251 			    mtod(m, const char *), tp, th);
11252 			rack_cc_conn_init(tp);
11253 		}
11254 	} else {
11255 		/*
11256 		 * Received initial SYN in SYN-SENT[*] state => simultaneous
11257 		 * open.  If segment contains CC option and there is a
11258 		 * cached CC, apply TAO test. If it succeeds, connection is *
11259 		 * half-synchronized. Otherwise, do 3-way handshake:
11260 		 * SYN-SENT -> SYN-RECEIVED SYN-SENT* -> SYN-RECEIVED* If
11261 		 * there was no CC option, clear cached CC value.
11262 		 */
11263 		tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN);
11264 		tcp_state_change(tp, TCPS_SYN_RECEIVED);
11265 	}
11266 	INP_WLOCK_ASSERT(tp->t_inpcb);
11267 	/*
11268 	 * Advance th->th_seq to correspond to first data byte. If data,
11269 	 * trim to stay within window, dropping FIN if necessary.
11270 	 */
11271 	th->th_seq++;
11272 	if (tlen > tp->rcv_wnd) {
11273 		todrop = tlen - tp->rcv_wnd;
11274 		m_adj(m, -todrop);
11275 		tlen = tp->rcv_wnd;
11276 		thflags &= ~TH_FIN;
11277 		KMOD_TCPSTAT_INC(tcps_rcvpackafterwin);
11278 		KMOD_TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop);
11279 	}
11280 	tp->snd_wl1 = th->th_seq - 1;
11281 	tp->rcv_up = th->th_seq;
11282 	/*
11283 	 * Client side of transaction: already sent SYN and data. If the
11284 	 * remote host used T/TCP to validate the SYN, our data will be
11285 	 * ACK'd; if so, enter normal data segment processing in the middle
11286 	 * of step 5, ack processing. Otherwise, goto step 6.
11287 	 */
11288 	if (thflags & TH_ACK) {
11289 		/* For syn-sent we need to possibly update the rtt */
11290 		if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
11291 			uint32_t t, mcts;
11292 
11293 			mcts = tcp_ts_getticks();
11294 			t = (mcts - to->to_tsecr) * HPTS_USEC_IN_MSEC;
11295 			if (!tp->t_rttlow || tp->t_rttlow > t)
11296 				tp->t_rttlow = t;
11297 			rack_log_rtt_sample_calc(rack, t, (to->to_tsecr * 1000), (mcts * 1000), 4);
11298 			tcp_rack_xmit_timer(rack, t + 1, 1, t, 0, NULL, 2);
11299 			tcp_rack_xmit_timer_commit(rack, tp);
11300 		}
11301 		if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val))
11302 			return (ret_val);
11303 		/* We may have changed to FIN_WAIT_1 above */
11304 		if (tp->t_state == TCPS_FIN_WAIT_1) {
11305 			/*
11306 			 * In FIN_WAIT_1 STATE in addition to the processing
11307 			 * for the ESTABLISHED state if our FIN is now
11308 			 * acknowledged then enter FIN_WAIT_2.
11309 			 */
11310 			if (ourfinisacked) {
11311 				/*
11312 				 * If we can't receive any more data, then
11313 				 * closing user can proceed. Starting the
11314 				 * timer is contrary to the specification,
11315 				 * but if we don't get a FIN we'll hang
11316 				 * forever.
11317 				 *
11318 				 * XXXjl: we should release the tp also, and
11319 				 * use a compressed state.
11320 				 */
11321 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
11322 					soisdisconnected(so);
11323 					tcp_timer_activate(tp, TT_2MSL,
11324 					    (tcp_fast_finwait2_recycle ?
11325 					    tcp_finwait2_timeout :
11326 					    TP_MAXIDLE(tp)));
11327 				}
11328 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
11329 			}
11330 		}
11331 	}
11332 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11333 	   tiwin, thflags, nxt_pkt));
11334 }
11335 
11336 /*
11337  * Return value of 1, the TCB is unlocked and most
11338  * likely gone, return value of 0, the TCP is still
11339  * locked.
11340  */
11341 static int
11342 rack_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
11343     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11344     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11345 {
11346 	struct tcp_rack *rack;
11347 	int32_t ret_val = 0;
11348 	int32_t ourfinisacked = 0;
11349 
11350 	ctf_calc_rwin(so, tp);
11351 	if ((thflags & TH_ACK) &&
11352 	    (SEQ_LEQ(th->th_ack, tp->snd_una) ||
11353 	    SEQ_GT(th->th_ack, tp->snd_max))) {
11354 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11355 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11356 		return (1);
11357 	}
11358 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11359 	if (IS_FASTOPEN(tp->t_flags)) {
11360 		/*
11361 		 * When a TFO connection is in SYN_RECEIVED, the
11362 		 * only valid packets are the initial SYN, a
11363 		 * retransmit/copy of the initial SYN (possibly with
11364 		 * a subset of the original data), a valid ACK, a
11365 		 * FIN, or a RST.
11366 		 */
11367 		if ((thflags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
11368 			tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11369 			ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11370 			return (1);
11371 		} else if (thflags & TH_SYN) {
11372 			/* non-initial SYN is ignored */
11373 			if ((rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT) ||
11374 			    (rack->r_ctl.rc_hpts_flags & PACE_TMR_TLP) ||
11375 			    (rack->r_ctl.rc_hpts_flags & PACE_TMR_RACK)) {
11376 				ctf_do_drop(m, NULL);
11377 				return (0);
11378 			}
11379 		} else if (!(thflags & (TH_ACK | TH_FIN | TH_RST))) {
11380 			ctf_do_drop(m, NULL);
11381 			return (0);
11382 		}
11383 	}
11384 
11385 	if ((thflags & TH_RST) ||
11386 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11387 		return (__ctf_process_rst(m, th, so, tp,
11388 					  &rack->r_ctl.challenge_ack_ts,
11389 					  &rack->r_ctl.challenge_ack_cnt));
11390 	/*
11391 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11392 	 * it's less than ts_recent, drop it.
11393 	 */
11394 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11395 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11396 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11397 			return (ret_val);
11398 	}
11399 	/*
11400 	 * In the SYN-RECEIVED state, validate that the packet belongs to
11401 	 * this connection before trimming the data to fit the receive
11402 	 * window.  Check the sequence number versus IRS since we know the
11403 	 * sequence numbers haven't wrapped.  This is a partial fix for the
11404 	 * "LAND" DoS attack.
11405 	 */
11406 	if (SEQ_LT(th->th_seq, tp->irs)) {
11407 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11408 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11409 		return (1);
11410 	}
11411 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11412 			      &rack->r_ctl.challenge_ack_ts,
11413 			      &rack->r_ctl.challenge_ack_cnt)) {
11414 		return (ret_val);
11415 	}
11416 	/*
11417 	 * If last ACK falls within this segment's sequence numbers, record
11418 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11419 	 * from the latest proposal of the tcplw@cray.com list (Braden
11420 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11421 	 * with our earlier PAWS tests, so this check should be solely
11422 	 * predicated on the sequence space of this segment. 3) That we
11423 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11424 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11425 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11426 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11427 	 * p.869. In such cases, we can still calculate the RTT correctly
11428 	 * when RCV.NXT == Last.ACK.Sent.
11429 	 */
11430 	if ((to->to_flags & TOF_TS) != 0 &&
11431 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11432 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11433 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11434 		tp->ts_recent_age = tcp_ts_getticks();
11435 		tp->ts_recent = to->to_tsval;
11436 	}
11437 	tp->snd_wnd = tiwin;
11438 	rack_validate_fo_sendwin_up(tp, rack);
11439 	/*
11440 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11441 	 * is on (half-synchronized state), then queue data for later
11442 	 * processing; else drop segment and return.
11443 	 */
11444 	if ((thflags & TH_ACK) == 0) {
11445 		if (IS_FASTOPEN(tp->t_flags)) {
11446 			rack_cc_conn_init(tp);
11447 		}
11448 		return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11449 		    tiwin, thflags, nxt_pkt));
11450 	}
11451 	KMOD_TCPSTAT_INC(tcps_connects);
11452 	soisconnected(so);
11453 	/* Do window scaling? */
11454 	if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
11455 	    (TF_RCVD_SCALE | TF_REQ_SCALE)) {
11456 		tp->rcv_scale = tp->request_r_scale;
11457 	}
11458 	/*
11459 	 * Make transitions: SYN-RECEIVED  -> ESTABLISHED SYN-RECEIVED* ->
11460 	 * FIN-WAIT-1
11461 	 */
11462 	tp->t_starttime = ticks;
11463 	if (IS_FASTOPEN(tp->t_flags) && tp->t_tfo_pending) {
11464 		tcp_fastopen_decrement_counter(tp->t_tfo_pending);
11465 		tp->t_tfo_pending = NULL;
11466 	}
11467 	if (tp->t_flags & TF_NEEDFIN) {
11468 		tcp_state_change(tp, TCPS_FIN_WAIT_1);
11469 		tp->t_flags &= ~TF_NEEDFIN;
11470 	} else {
11471 		tcp_state_change(tp, TCPS_ESTABLISHED);
11472 		TCP_PROBE5(accept__established, NULL, tp,
11473 		    mtod(m, const char *), tp, th);
11474 		/*
11475 		 * TFO connections call cc_conn_init() during SYN
11476 		 * processing.  Calling it again here for such connections
11477 		 * is not harmless as it would undo the snd_cwnd reduction
11478 		 * that occurs when a TFO SYN|ACK is retransmitted.
11479 		 */
11480 		if (!IS_FASTOPEN(tp->t_flags))
11481 			rack_cc_conn_init(tp);
11482 	}
11483 	/*
11484 	 * Account for the ACK of our SYN prior to
11485 	 * regular ACK processing below, except for
11486 	 * simultaneous SYN, which is handled later.
11487 	 */
11488 	if (SEQ_GT(th->th_ack, tp->snd_una) && !(tp->t_flags & TF_NEEDSYN))
11489 		tp->snd_una++;
11490 	/*
11491 	 * If segment contains data or ACK, will call tcp_reass() later; if
11492 	 * not, do so now to pass queued data to user.
11493 	 */
11494 	if (tlen == 0 && (thflags & TH_FIN) == 0) {
11495 		(void) tcp_reass(tp, (struct tcphdr *)0, NULL, 0,
11496 		    (struct mbuf *)0);
11497 		if (tp->t_flags & TF_WAKESOR) {
11498 			tp->t_flags &= ~TF_WAKESOR;
11499 			/* NB: sorwakeup_locked() does an implicit unlock. */
11500 			sorwakeup_locked(so);
11501 		}
11502 	}
11503 	tp->snd_wl1 = th->th_seq - 1;
11504 	/* For syn-recv we need to possibly update the rtt */
11505 	if ((to->to_flags & TOF_TS) != 0 && to->to_tsecr) {
11506 		uint32_t t, mcts;
11507 
11508 		mcts = tcp_ts_getticks();
11509 		t = (mcts - to->to_tsecr) * HPTS_USEC_IN_MSEC;
11510 		if (!tp->t_rttlow || tp->t_rttlow > t)
11511 			tp->t_rttlow = t;
11512 		rack_log_rtt_sample_calc(rack, t, (to->to_tsecr * 1000), (mcts * 1000), 5);
11513 		tcp_rack_xmit_timer(rack, t + 1, 1, t, 0, NULL, 2);
11514 		tcp_rack_xmit_timer_commit(rack, tp);
11515 	}
11516 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
11517 		return (ret_val);
11518 	}
11519 	if (tp->t_state == TCPS_FIN_WAIT_1) {
11520 		/* We could have went to FIN_WAIT_1 (or EST) above */
11521 		/*
11522 		 * In FIN_WAIT_1 STATE in addition to the processing for the
11523 		 * ESTABLISHED state if our FIN is now acknowledged then
11524 		 * enter FIN_WAIT_2.
11525 		 */
11526 		if (ourfinisacked) {
11527 			/*
11528 			 * If we can't receive any more data, then closing
11529 			 * user can proceed. Starting the timer is contrary
11530 			 * to the specification, but if we don't get a FIN
11531 			 * we'll hang forever.
11532 			 *
11533 			 * XXXjl: we should release the tp also, and use a
11534 			 * compressed state.
11535 			 */
11536 			if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
11537 				soisdisconnected(so);
11538 				tcp_timer_activate(tp, TT_2MSL,
11539 				    (tcp_fast_finwait2_recycle ?
11540 				    tcp_finwait2_timeout :
11541 				    TP_MAXIDLE(tp)));
11542 			}
11543 			tcp_state_change(tp, TCPS_FIN_WAIT_2);
11544 		}
11545 	}
11546 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11547 	    tiwin, thflags, nxt_pkt));
11548 }
11549 
11550 /*
11551  * Return value of 1, the TCB is unlocked and most
11552  * likely gone, return value of 0, the TCP is still
11553  * locked.
11554  */
11555 static int
11556 rack_do_established(struct mbuf *m, struct tcphdr *th, struct socket *so,
11557     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11558     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11559 {
11560 	int32_t ret_val = 0;
11561 	struct tcp_rack *rack;
11562 
11563 	/*
11564 	 * Header prediction: check for the two common cases of a
11565 	 * uni-directional data xfer.  If the packet has no control flags,
11566 	 * is in-sequence, the window didn't change and we're not
11567 	 * retransmitting, it's a candidate.  If the length is zero and the
11568 	 * ack moved forward, we're the sender side of the xfer.  Just free
11569 	 * the data acked & wake any higher level process that was blocked
11570 	 * waiting for space.  If the length is non-zero and the ack didn't
11571 	 * move, we're the receiver side.  If we're getting packets in-order
11572 	 * (the reassembly queue is empty), add the data toc The socket
11573 	 * buffer and note that we need a delayed ack. Make sure that the
11574 	 * hidden state-flags are also off. Since we check for
11575 	 * TCPS_ESTABLISHED first, it can only be TH_NEEDSYN.
11576 	 */
11577 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11578 	if (__predict_true(((to->to_flags & TOF_SACK) == 0)) &&
11579 	    __predict_true((thflags & (TH_SYN | TH_FIN | TH_RST | TH_ACK)) == TH_ACK) &&
11580 	    __predict_true(SEGQ_EMPTY(tp)) &&
11581 	    __predict_true(th->th_seq == tp->rcv_nxt)) {
11582 		if (tlen == 0) {
11583 			if (rack_fastack(m, th, so, tp, to, drop_hdrlen, tlen,
11584 			    tiwin, nxt_pkt, rack->r_ctl.rc_rcvtime)) {
11585 				return (0);
11586 			}
11587 		} else {
11588 			if (rack_do_fastnewdata(m, th, so, tp, to, drop_hdrlen, tlen,
11589 			    tiwin, nxt_pkt, iptos)) {
11590 				return (0);
11591 			}
11592 		}
11593 	}
11594 	ctf_calc_rwin(so, tp);
11595 
11596 	if ((thflags & TH_RST) ||
11597 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11598 		return (__ctf_process_rst(m, th, so, tp,
11599 					  &rack->r_ctl.challenge_ack_ts,
11600 					  &rack->r_ctl.challenge_ack_cnt));
11601 
11602 	/*
11603 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11604 	 * synchronized state.
11605 	 */
11606 	if (thflags & TH_SYN) {
11607 		ctf_challenge_ack(m, th, tp, &ret_val);
11608 		return (ret_val);
11609 	}
11610 	/*
11611 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11612 	 * it's less than ts_recent, drop it.
11613 	 */
11614 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11615 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11616 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11617 			return (ret_val);
11618 	}
11619 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11620 			      &rack->r_ctl.challenge_ack_ts,
11621 			      &rack->r_ctl.challenge_ack_cnt)) {
11622 		return (ret_val);
11623 	}
11624 	/*
11625 	 * If last ACK falls within this segment's sequence numbers, record
11626 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11627 	 * from the latest proposal of the tcplw@cray.com list (Braden
11628 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11629 	 * with our earlier PAWS tests, so this check should be solely
11630 	 * predicated on the sequence space of this segment. 3) That we
11631 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11632 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11633 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11634 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11635 	 * p.869. In such cases, we can still calculate the RTT correctly
11636 	 * when RCV.NXT == Last.ACK.Sent.
11637 	 */
11638 	if ((to->to_flags & TOF_TS) != 0 &&
11639 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11640 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11641 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11642 		tp->ts_recent_age = tcp_ts_getticks();
11643 		tp->ts_recent = to->to_tsval;
11644 	}
11645 	/*
11646 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11647 	 * is on (half-synchronized state), then queue data for later
11648 	 * processing; else drop segment and return.
11649 	 */
11650 	if ((thflags & TH_ACK) == 0) {
11651 		if (tp->t_flags & TF_NEEDSYN) {
11652 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11653 			    tiwin, thflags, nxt_pkt));
11654 
11655 		} else if (tp->t_flags & TF_ACKNOW) {
11656 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
11657 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
11658 			return (ret_val);
11659 		} else {
11660 			ctf_do_drop(m, NULL);
11661 			return (0);
11662 		}
11663 	}
11664 	/*
11665 	 * Ack processing.
11666 	 */
11667 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
11668 		return (ret_val);
11669 	}
11670 	if (sbavail(&so->so_snd)) {
11671 		if (ctf_progress_timeout_check(tp, true)) {
11672 			rack_log_progress_event(rack, tp, tick, PROGRESS_DROP, __LINE__);
11673 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11674 			return (1);
11675 		}
11676 	}
11677 	/* State changes only happen in rack_process_data() */
11678 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11679 	    tiwin, thflags, nxt_pkt));
11680 }
11681 
11682 /*
11683  * Return value of 1, the TCB is unlocked and most
11684  * likely gone, return value of 0, the TCP is still
11685  * locked.
11686  */
11687 static int
11688 rack_do_close_wait(struct mbuf *m, struct tcphdr *th, struct socket *so,
11689     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11690     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11691 {
11692 	int32_t ret_val = 0;
11693 	struct tcp_rack *rack;
11694 
11695 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11696 	ctf_calc_rwin(so, tp);
11697 	if ((thflags & TH_RST) ||
11698 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11699 		return (__ctf_process_rst(m, th, so, tp,
11700 					  &rack->r_ctl.challenge_ack_ts,
11701 					  &rack->r_ctl.challenge_ack_cnt));
11702 	/*
11703 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11704 	 * synchronized state.
11705 	 */
11706 	if (thflags & TH_SYN) {
11707 		ctf_challenge_ack(m, th, tp, &ret_val);
11708 		return (ret_val);
11709 	}
11710 	/*
11711 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11712 	 * it's less than ts_recent, drop it.
11713 	 */
11714 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11715 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11716 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11717 			return (ret_val);
11718 	}
11719 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11720 			      &rack->r_ctl.challenge_ack_ts,
11721 			      &rack->r_ctl.challenge_ack_cnt)) {
11722 		return (ret_val);
11723 	}
11724 	/*
11725 	 * If last ACK falls within this segment's sequence numbers, record
11726 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11727 	 * from the latest proposal of the tcplw@cray.com list (Braden
11728 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11729 	 * with our earlier PAWS tests, so this check should be solely
11730 	 * predicated on the sequence space of this segment. 3) That we
11731 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11732 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11733 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11734 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11735 	 * p.869. In such cases, we can still calculate the RTT correctly
11736 	 * when RCV.NXT == Last.ACK.Sent.
11737 	 */
11738 	if ((to->to_flags & TOF_TS) != 0 &&
11739 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11740 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11741 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11742 		tp->ts_recent_age = tcp_ts_getticks();
11743 		tp->ts_recent = to->to_tsval;
11744 	}
11745 	/*
11746 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11747 	 * is on (half-synchronized state), then queue data for later
11748 	 * processing; else drop segment and return.
11749 	 */
11750 	if ((thflags & TH_ACK) == 0) {
11751 		if (tp->t_flags & TF_NEEDSYN) {
11752 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11753 			    tiwin, thflags, nxt_pkt));
11754 
11755 		} else if (tp->t_flags & TF_ACKNOW) {
11756 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
11757 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
11758 			return (ret_val);
11759 		} else {
11760 			ctf_do_drop(m, NULL);
11761 			return (0);
11762 		}
11763 	}
11764 	/*
11765 	 * Ack processing.
11766 	 */
11767 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
11768 		return (ret_val);
11769 	}
11770 	if (sbavail(&so->so_snd)) {
11771 		if (ctf_progress_timeout_check(tp, true)) {
11772 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
11773 						tp, tick, PROGRESS_DROP, __LINE__);
11774 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11775 			return (1);
11776 		}
11777 	}
11778 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11779 	    tiwin, thflags, nxt_pkt));
11780 }
11781 
11782 static int
11783 rack_check_data_after_close(struct mbuf *m,
11784     struct tcpcb *tp, int32_t *tlen, struct tcphdr *th, struct socket *so)
11785 {
11786 	struct tcp_rack *rack;
11787 
11788 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11789 	if (rack->rc_allow_data_af_clo == 0) {
11790 	close_now:
11791 		tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
11792 		/* tcp_close will kill the inp pre-log the Reset */
11793 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
11794 		tp = tcp_close(tp);
11795 		KMOD_TCPSTAT_INC(tcps_rcvafterclose);
11796 		ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, (*tlen));
11797 		return (1);
11798 	}
11799 	if (sbavail(&so->so_snd) == 0)
11800 		goto close_now;
11801 	/* Ok we allow data that is ignored and a followup reset */
11802 	tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
11803 	tp->rcv_nxt = th->th_seq + *tlen;
11804 	tp->t_flags2 |= TF2_DROP_AF_DATA;
11805 	rack->r_wanted_output = 1;
11806 	*tlen = 0;
11807 	return (0);
11808 }
11809 
11810 /*
11811  * Return value of 1, the TCB is unlocked and most
11812  * likely gone, return value of 0, the TCP is still
11813  * locked.
11814  */
11815 static int
11816 rack_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, struct socket *so,
11817     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11818     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11819 {
11820 	int32_t ret_val = 0;
11821 	int32_t ourfinisacked = 0;
11822 	struct tcp_rack *rack;
11823 
11824 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11825 	ctf_calc_rwin(so, tp);
11826 
11827 	if ((thflags & TH_RST) ||
11828 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11829 		return (__ctf_process_rst(m, th, so, tp,
11830 					  &rack->r_ctl.challenge_ack_ts,
11831 					  &rack->r_ctl.challenge_ack_cnt));
11832 	/*
11833 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11834 	 * synchronized state.
11835 	 */
11836 	if (thflags & TH_SYN) {
11837 		ctf_challenge_ack(m, th, tp, &ret_val);
11838 		return (ret_val);
11839 	}
11840 	/*
11841 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11842 	 * it's less than ts_recent, drop it.
11843 	 */
11844 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11845 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11846 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11847 			return (ret_val);
11848 	}
11849 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11850 			      &rack->r_ctl.challenge_ack_ts,
11851 			      &rack->r_ctl.challenge_ack_cnt)) {
11852 		return (ret_val);
11853 	}
11854 	/*
11855 	 * If new data are received on a connection after the user processes
11856 	 * are gone, then RST the other end.
11857 	 */
11858 	if ((tp->t_flags & TF_CLOSED) && tlen &&
11859 	    rack_check_data_after_close(m, tp, &tlen, th, so))
11860 		return (1);
11861 	/*
11862 	 * If last ACK falls within this segment's sequence numbers, record
11863 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11864 	 * from the latest proposal of the tcplw@cray.com list (Braden
11865 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11866 	 * with our earlier PAWS tests, so this check should be solely
11867 	 * predicated on the sequence space of this segment. 3) That we
11868 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11869 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11870 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11871 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11872 	 * p.869. In such cases, we can still calculate the RTT correctly
11873 	 * when RCV.NXT == Last.ACK.Sent.
11874 	 */
11875 	if ((to->to_flags & TOF_TS) != 0 &&
11876 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
11877 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
11878 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
11879 		tp->ts_recent_age = tcp_ts_getticks();
11880 		tp->ts_recent = to->to_tsval;
11881 	}
11882 	/*
11883 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
11884 	 * is on (half-synchronized state), then queue data for later
11885 	 * processing; else drop segment and return.
11886 	 */
11887 	if ((thflags & TH_ACK) == 0) {
11888 		if (tp->t_flags & TF_NEEDSYN) {
11889 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11890 			    tiwin, thflags, nxt_pkt));
11891 		} else if (tp->t_flags & TF_ACKNOW) {
11892 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
11893 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
11894 			return (ret_val);
11895 		} else {
11896 			ctf_do_drop(m, NULL);
11897 			return (0);
11898 		}
11899 	}
11900 	/*
11901 	 * Ack processing.
11902 	 */
11903 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
11904 		return (ret_val);
11905 	}
11906 	if (ourfinisacked) {
11907 		/*
11908 		 * If we can't receive any more data, then closing user can
11909 		 * proceed. Starting the timer is contrary to the
11910 		 * specification, but if we don't get a FIN we'll hang
11911 		 * forever.
11912 		 *
11913 		 * XXXjl: we should release the tp also, and use a
11914 		 * compressed state.
11915 		 */
11916 		if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
11917 			soisdisconnected(so);
11918 			tcp_timer_activate(tp, TT_2MSL,
11919 			    (tcp_fast_finwait2_recycle ?
11920 			    tcp_finwait2_timeout :
11921 			    TP_MAXIDLE(tp)));
11922 		}
11923 		tcp_state_change(tp, TCPS_FIN_WAIT_2);
11924 	}
11925 	if (sbavail(&so->so_snd)) {
11926 		if (ctf_progress_timeout_check(tp, true)) {
11927 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
11928 						tp, tick, PROGRESS_DROP, __LINE__);
11929 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11930 			return (1);
11931 		}
11932 	}
11933 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
11934 	    tiwin, thflags, nxt_pkt));
11935 }
11936 
11937 /*
11938  * Return value of 1, the TCB is unlocked and most
11939  * likely gone, return value of 0, the TCP is still
11940  * locked.
11941  */
11942 static int
11943 rack_do_closing(struct mbuf *m, struct tcphdr *th, struct socket *so,
11944     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
11945     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
11946 {
11947 	int32_t ret_val = 0;
11948 	int32_t ourfinisacked = 0;
11949 	struct tcp_rack *rack;
11950 
11951 	rack = (struct tcp_rack *)tp->t_fb_ptr;
11952 	ctf_calc_rwin(so, tp);
11953 
11954 	if ((thflags & TH_RST) ||
11955 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
11956 		return (__ctf_process_rst(m, th, so, tp,
11957 					  &rack->r_ctl.challenge_ack_ts,
11958 					  &rack->r_ctl.challenge_ack_cnt));
11959 	/*
11960 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
11961 	 * synchronized state.
11962 	 */
11963 	if (thflags & TH_SYN) {
11964 		ctf_challenge_ack(m, th, tp, &ret_val);
11965 		return (ret_val);
11966 	}
11967 	/*
11968 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
11969 	 * it's less than ts_recent, drop it.
11970 	 */
11971 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
11972 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
11973 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
11974 			return (ret_val);
11975 	}
11976 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
11977 			      &rack->r_ctl.challenge_ack_ts,
11978 			      &rack->r_ctl.challenge_ack_cnt)) {
11979 		return (ret_val);
11980 	}
11981 	/*
11982 	 * If new data are received on a connection after the user processes
11983 	 * are gone, then RST the other end.
11984 	 */
11985 	if ((tp->t_flags & TF_CLOSED) && tlen &&
11986 	    rack_check_data_after_close(m, tp, &tlen, th, so))
11987 		return (1);
11988 	/*
11989 	 * If last ACK falls within this segment's sequence numbers, record
11990 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
11991 	 * from the latest proposal of the tcplw@cray.com list (Braden
11992 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
11993 	 * with our earlier PAWS tests, so this check should be solely
11994 	 * predicated on the sequence space of this segment. 3) That we
11995 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
11996 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
11997 	 * SEG.Len, This modified check allows us to overcome RFC1323's
11998 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
11999 	 * p.869. In such cases, we can still calculate the RTT correctly
12000 	 * when RCV.NXT == Last.ACK.Sent.
12001 	 */
12002 	if ((to->to_flags & TOF_TS) != 0 &&
12003 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
12004 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
12005 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
12006 		tp->ts_recent_age = tcp_ts_getticks();
12007 		tp->ts_recent = to->to_tsval;
12008 	}
12009 	/*
12010 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
12011 	 * is on (half-synchronized state), then queue data for later
12012 	 * processing; else drop segment and return.
12013 	 */
12014 	if ((thflags & TH_ACK) == 0) {
12015 		if (tp->t_flags & TF_NEEDSYN) {
12016 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12017 			    tiwin, thflags, nxt_pkt));
12018 		} else if (tp->t_flags & TF_ACKNOW) {
12019 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
12020 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
12021 			return (ret_val);
12022 		} else {
12023 			ctf_do_drop(m, NULL);
12024 			return (0);
12025 		}
12026 	}
12027 	/*
12028 	 * Ack processing.
12029 	 */
12030 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
12031 		return (ret_val);
12032 	}
12033 	if (ourfinisacked) {
12034 		tcp_twstart(tp);
12035 		m_freem(m);
12036 		return (1);
12037 	}
12038 	if (sbavail(&so->so_snd)) {
12039 		if (ctf_progress_timeout_check(tp, true)) {
12040 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
12041 						tp, tick, PROGRESS_DROP, __LINE__);
12042 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
12043 			return (1);
12044 		}
12045 	}
12046 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12047 	    tiwin, thflags, nxt_pkt));
12048 }
12049 
12050 /*
12051  * Return value of 1, the TCB is unlocked and most
12052  * likely gone, return value of 0, the TCP is still
12053  * locked.
12054  */
12055 static int
12056 rack_do_lastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
12057     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12058     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
12059 {
12060 	int32_t ret_val = 0;
12061 	int32_t ourfinisacked = 0;
12062 	struct tcp_rack *rack;
12063 
12064 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12065 	ctf_calc_rwin(so, tp);
12066 
12067 	if ((thflags & TH_RST) ||
12068 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
12069 		return (__ctf_process_rst(m, th, so, tp,
12070 					  &rack->r_ctl.challenge_ack_ts,
12071 					  &rack->r_ctl.challenge_ack_cnt));
12072 	/*
12073 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
12074 	 * synchronized state.
12075 	 */
12076 	if (thflags & TH_SYN) {
12077 		ctf_challenge_ack(m, th, tp, &ret_val);
12078 		return (ret_val);
12079 	}
12080 	/*
12081 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
12082 	 * it's less than ts_recent, drop it.
12083 	 */
12084 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
12085 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
12086 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
12087 			return (ret_val);
12088 	}
12089 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
12090 			      &rack->r_ctl.challenge_ack_ts,
12091 			      &rack->r_ctl.challenge_ack_cnt)) {
12092 		return (ret_val);
12093 	}
12094 	/*
12095 	 * If new data are received on a connection after the user processes
12096 	 * are gone, then RST the other end.
12097 	 */
12098 	if ((tp->t_flags & TF_CLOSED) && tlen &&
12099 	    rack_check_data_after_close(m, tp, &tlen, th, so))
12100 		return (1);
12101 	/*
12102 	 * If last ACK falls within this segment's sequence numbers, record
12103 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
12104 	 * from the latest proposal of the tcplw@cray.com list (Braden
12105 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
12106 	 * with our earlier PAWS tests, so this check should be solely
12107 	 * predicated on the sequence space of this segment. 3) That we
12108 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
12109 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
12110 	 * SEG.Len, This modified check allows us to overcome RFC1323's
12111 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
12112 	 * p.869. In such cases, we can still calculate the RTT correctly
12113 	 * when RCV.NXT == Last.ACK.Sent.
12114 	 */
12115 	if ((to->to_flags & TOF_TS) != 0 &&
12116 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
12117 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
12118 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
12119 		tp->ts_recent_age = tcp_ts_getticks();
12120 		tp->ts_recent = to->to_tsval;
12121 	}
12122 	/*
12123 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
12124 	 * is on (half-synchronized state), then queue data for later
12125 	 * processing; else drop segment and return.
12126 	 */
12127 	if ((thflags & TH_ACK) == 0) {
12128 		if (tp->t_flags & TF_NEEDSYN) {
12129 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12130 			    tiwin, thflags, nxt_pkt));
12131 		} else if (tp->t_flags & TF_ACKNOW) {
12132 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
12133 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
12134 			return (ret_val);
12135 		} else {
12136 			ctf_do_drop(m, NULL);
12137 			return (0);
12138 		}
12139 	}
12140 	/*
12141 	 * case TCPS_LAST_ACK: Ack processing.
12142 	 */
12143 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
12144 		return (ret_val);
12145 	}
12146 	if (ourfinisacked) {
12147 		tp = tcp_close(tp);
12148 		ctf_do_drop(m, tp);
12149 		return (1);
12150 	}
12151 	if (sbavail(&so->so_snd)) {
12152 		if (ctf_progress_timeout_check(tp, true)) {
12153 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
12154 						tp, tick, PROGRESS_DROP, __LINE__);
12155 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
12156 			return (1);
12157 		}
12158 	}
12159 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12160 	    tiwin, thflags, nxt_pkt));
12161 }
12162 
12163 /*
12164  * Return value of 1, the TCB is unlocked and most
12165  * likely gone, return value of 0, the TCP is still
12166  * locked.
12167  */
12168 static int
12169 rack_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, struct socket *so,
12170     struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
12171     uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
12172 {
12173 	int32_t ret_val = 0;
12174 	int32_t ourfinisacked = 0;
12175 	struct tcp_rack *rack;
12176 
12177 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12178 	ctf_calc_rwin(so, tp);
12179 
12180 	/* Reset receive buffer auto scaling when not in bulk receive mode. */
12181 	if ((thflags & TH_RST) ||
12182 	    (tp->t_fin_is_rst && (thflags & TH_FIN)))
12183 		return (__ctf_process_rst(m, th, so, tp,
12184 					  &rack->r_ctl.challenge_ack_ts,
12185 					  &rack->r_ctl.challenge_ack_cnt));
12186 	/*
12187 	 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
12188 	 * synchronized state.
12189 	 */
12190 	if (thflags & TH_SYN) {
12191 		ctf_challenge_ack(m, th, tp, &ret_val);
12192 		return (ret_val);
12193 	}
12194 	/*
12195 	 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
12196 	 * it's less than ts_recent, drop it.
12197 	 */
12198 	if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
12199 	    TSTMP_LT(to->to_tsval, tp->ts_recent)) {
12200 		if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
12201 			return (ret_val);
12202 	}
12203 	if (_ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val,
12204 			      &rack->r_ctl.challenge_ack_ts,
12205 			      &rack->r_ctl.challenge_ack_cnt)) {
12206 		return (ret_val);
12207 	}
12208 	/*
12209 	 * If new data are received on a connection after the user processes
12210 	 * are gone, then RST the other end.
12211 	 */
12212 	if ((tp->t_flags & TF_CLOSED) && tlen &&
12213 	    rack_check_data_after_close(m, tp, &tlen, th, so))
12214 		return (1);
12215 	/*
12216 	 * If last ACK falls within this segment's sequence numbers, record
12217 	 * its timestamp. NOTE: 1) That the test incorporates suggestions
12218 	 * from the latest proposal of the tcplw@cray.com list (Braden
12219 	 * 1993/04/26). 2) That updating only on newer timestamps interferes
12220 	 * with our earlier PAWS tests, so this check should be solely
12221 	 * predicated on the sequence space of this segment. 3) That we
12222 	 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
12223 	 * + SEG.Len  instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
12224 	 * SEG.Len, This modified check allows us to overcome RFC1323's
12225 	 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
12226 	 * p.869. In such cases, we can still calculate the RTT correctly
12227 	 * when RCV.NXT == Last.ACK.Sent.
12228 	 */
12229 	if ((to->to_flags & TOF_TS) != 0 &&
12230 	    SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
12231 	    SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
12232 	    ((thflags & (TH_SYN | TH_FIN)) != 0))) {
12233 		tp->ts_recent_age = tcp_ts_getticks();
12234 		tp->ts_recent = to->to_tsval;
12235 	}
12236 	/*
12237 	 * If the ACK bit is off:  if in SYN-RECEIVED state or SENDSYN flag
12238 	 * is on (half-synchronized state), then queue data for later
12239 	 * processing; else drop segment and return.
12240 	 */
12241 	if ((thflags & TH_ACK) == 0) {
12242 		if (tp->t_flags & TF_NEEDSYN) {
12243 			return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12244 			    tiwin, thflags, nxt_pkt));
12245 		} else if (tp->t_flags & TF_ACKNOW) {
12246 			ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
12247 			((struct tcp_rack *)tp->t_fb_ptr)->r_wanted_output = 1;
12248 			return (ret_val);
12249 		} else {
12250 			ctf_do_drop(m, NULL);
12251 			return (0);
12252 		}
12253 	}
12254 	/*
12255 	 * Ack processing.
12256 	 */
12257 	if (rack_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
12258 		return (ret_val);
12259 	}
12260 	if (sbavail(&so->so_snd)) {
12261 		if (ctf_progress_timeout_check(tp, true)) {
12262 			rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
12263 						tp, tick, PROGRESS_DROP, __LINE__);
12264 			ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
12265 			return (1);
12266 		}
12267 	}
12268 	return (rack_process_data(m, th, so, tp, drop_hdrlen, tlen,
12269 	    tiwin, thflags, nxt_pkt));
12270 }
12271 
12272 static void inline
12273 rack_clear_rate_sample(struct tcp_rack *rack)
12274 {
12275 	rack->r_ctl.rack_rs.rs_flags = RACK_RTT_EMPTY;
12276 	rack->r_ctl.rack_rs.rs_rtt_cnt = 0;
12277 	rack->r_ctl.rack_rs.rs_rtt_tot = 0;
12278 }
12279 
12280 static void
12281 rack_set_pace_segments(struct tcpcb *tp, struct tcp_rack *rack, uint32_t line, uint64_t *fill_override)
12282 {
12283 	uint64_t bw_est, rate_wanted;
12284 	int chged = 0;
12285 	uint32_t user_max, orig_min, orig_max;
12286 
12287 	orig_min = rack->r_ctl.rc_pace_min_segs;
12288 	orig_max = rack->r_ctl.rc_pace_max_segs;
12289 	user_max = ctf_fixed_maxseg(tp) * rack->rc_user_set_max_segs;
12290 	if (ctf_fixed_maxseg(tp) != rack->r_ctl.rc_pace_min_segs)
12291 		chged = 1;
12292 	rack->r_ctl.rc_pace_min_segs = ctf_fixed_maxseg(tp);
12293 	if (rack->use_fixed_rate || rack->rc_force_max_seg) {
12294 		if (user_max != rack->r_ctl.rc_pace_max_segs)
12295 			chged = 1;
12296 	}
12297 	if (rack->rc_force_max_seg) {
12298 		rack->r_ctl.rc_pace_max_segs = user_max;
12299 	} else if (rack->use_fixed_rate) {
12300 		bw_est = rack_get_bw(rack);
12301 		if ((rack->r_ctl.crte == NULL) ||
12302 		    (bw_est != rack->r_ctl.crte->rate)) {
12303 			rack->r_ctl.rc_pace_max_segs = user_max;
12304 		} else {
12305 			/* We are pacing right at the hardware rate */
12306 			uint32_t segsiz;
12307 
12308 			segsiz = min(ctf_fixed_maxseg(tp),
12309 				     rack->r_ctl.rc_pace_min_segs);
12310 			rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(
12311 				                           tp, bw_est, segsiz, 0,
12312 							   rack->r_ctl.crte, NULL);
12313 		}
12314 	} else if (rack->rc_always_pace) {
12315 		if (rack->r_ctl.gp_bw ||
12316 #ifdef NETFLIX_PEAKRATE
12317 		    rack->rc_tp->t_maxpeakrate ||
12318 #endif
12319 		    rack->r_ctl.init_rate) {
12320 			/* We have a rate of some sort set */
12321 			uint32_t  orig;
12322 
12323 			bw_est = rack_get_bw(rack);
12324 			orig = rack->r_ctl.rc_pace_max_segs;
12325 			if (fill_override)
12326 				rate_wanted = *fill_override;
12327 			else
12328 				rate_wanted = rack_get_output_bw(rack, bw_est, NULL, NULL);
12329 			if (rate_wanted) {
12330 				/* We have something */
12331 				rack->r_ctl.rc_pace_max_segs = rack_get_pacing_len(rack,
12332 										   rate_wanted,
12333 										   ctf_fixed_maxseg(rack->rc_tp));
12334 			} else
12335 				rack->r_ctl.rc_pace_max_segs = rack->r_ctl.rc_pace_min_segs;
12336 			if (orig != rack->r_ctl.rc_pace_max_segs)
12337 				chged = 1;
12338 		} else if ((rack->r_ctl.gp_bw == 0) &&
12339 			   (rack->r_ctl.rc_pace_max_segs == 0)) {
12340 			/*
12341 			 * If we have nothing limit us to bursting
12342 			 * out IW sized pieces.
12343 			 */
12344 			chged = 1;
12345 			rack->r_ctl.rc_pace_max_segs = rc_init_window(rack);
12346 		}
12347 	}
12348 	if (rack->r_ctl.rc_pace_max_segs > PACE_MAX_IP_BYTES) {
12349 		chged = 1;
12350 		rack->r_ctl.rc_pace_max_segs = PACE_MAX_IP_BYTES;
12351 	}
12352 	if (chged)
12353 		rack_log_type_pacing_sizes(tp, rack, orig_min, orig_max, line, 2);
12354 }
12355 
12356 
12357 static void
12358 rack_init_fsb_block(struct tcpcb *tp, struct tcp_rack *rack)
12359 {
12360 #ifdef INET6
12361 	struct ip6_hdr *ip6 = NULL;
12362 #endif
12363 #ifdef INET
12364 	struct ip *ip = NULL;
12365 #endif
12366 	struct udphdr *udp = NULL;
12367 
12368 	/* Ok lets fill in the fast block, it can only be used with no IP options! */
12369 #ifdef INET6
12370 	if (rack->r_is_v6) {
12371 		rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
12372 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
12373 		if (tp->t_port) {
12374 			rack->r_ctl.fsb.tcp_ip_hdr_len += sizeof(struct udphdr);
12375 			udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
12376 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
12377 			udp->uh_dport = tp->t_port;
12378 			rack->r_ctl.fsb.udp = udp;
12379 			rack->r_ctl.fsb.th = (struct tcphdr *)(udp + 1);
12380 		} else
12381 		{
12382 			rack->r_ctl.fsb.th = (struct tcphdr *)(ip6 + 1);
12383 			rack->r_ctl.fsb.udp = NULL;
12384 		}
12385 		tcpip_fillheaders(rack->rc_inp,
12386 				  tp->t_port,
12387 				  ip6, rack->r_ctl.fsb.th);
12388 	} else
12389 #endif				/* INET6 */
12390 	{
12391 		rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct tcpiphdr);
12392 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
12393 		if (tp->t_port) {
12394 			rack->r_ctl.fsb.tcp_ip_hdr_len += sizeof(struct udphdr);
12395 			udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
12396 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
12397 			udp->uh_dport = tp->t_port;
12398 			rack->r_ctl.fsb.udp = udp;
12399 			rack->r_ctl.fsb.th = (struct tcphdr *)(udp + 1);
12400 		} else
12401 		{
12402 			rack->r_ctl.fsb.udp = NULL;
12403 			rack->r_ctl.fsb.th = (struct tcphdr *)(ip + 1);
12404 		}
12405 		tcpip_fillheaders(rack->rc_inp,
12406 				  tp->t_port,
12407 				  ip, rack->r_ctl.fsb.th);
12408 	}
12409 	rack->r_fsb_inited = 1;
12410 }
12411 
12412 static int
12413 rack_init_fsb(struct tcpcb *tp, struct tcp_rack *rack)
12414 {
12415 	/*
12416 	 * Allocate the larger of spaces V6 if available else just
12417 	 * V4 and include udphdr (overbook)
12418 	 */
12419 #ifdef INET6
12420 	rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + sizeof(struct udphdr);
12421 #else
12422 	rack->r_ctl.fsb.tcp_ip_hdr_len = sizeof(struct tcpiphdr) + sizeof(struct udphdr);
12423 #endif
12424 	rack->r_ctl.fsb.tcp_ip_hdr = malloc(rack->r_ctl.fsb.tcp_ip_hdr_len,
12425 					    M_TCPFSB, M_NOWAIT|M_ZERO);
12426 	if (rack->r_ctl.fsb.tcp_ip_hdr == NULL) {
12427 		return (ENOMEM);
12428 	}
12429 	rack->r_fsb_inited = 0;
12430 	return (0);
12431 }
12432 
12433 static int
12434 rack_init(struct tcpcb *tp)
12435 {
12436 	struct tcp_rack *rack = NULL;
12437 #ifdef INVARIANTS
12438 	struct rack_sendmap *insret;
12439 #endif
12440 	uint32_t iwin, snt, us_cts;
12441 	int err;
12442 
12443 	tp->t_fb_ptr = uma_zalloc(rack_pcb_zone, M_NOWAIT);
12444 	if (tp->t_fb_ptr == NULL) {
12445 		/*
12446 		 * We need to allocate memory but cant. The INP and INP_INFO
12447 		 * locks and they are recursive (happens during setup. So a
12448 		 * scheme to drop the locks fails :(
12449 		 *
12450 		 */
12451 		return (ENOMEM);
12452 	}
12453 	memset(tp->t_fb_ptr, 0, sizeof(struct tcp_rack));
12454 
12455 	rack = (struct tcp_rack *)tp->t_fb_ptr;
12456 	RB_INIT(&rack->r_ctl.rc_mtree);
12457 	TAILQ_INIT(&rack->r_ctl.rc_free);
12458 	TAILQ_INIT(&rack->r_ctl.rc_tmap);
12459 	rack->rc_tp = tp;
12460 	rack->rc_inp = tp->t_inpcb;
12461 	/* Set the flag */
12462 	rack->r_is_v6 = (tp->t_inpcb->inp_vflag & INP_IPV6) != 0;
12463 	/* Probably not needed but lets be sure */
12464 	rack_clear_rate_sample(rack);
12465 	/*
12466 	 * Save off the default values, socket options will poke
12467 	 * at these if pacing is not on or we have not yet
12468 	 * reached where pacing is on (gp_ready/fixed enabled).
12469 	 * When they get set into the CC module (when gp_ready
12470 	 * is enabled or we enable fixed) then we will set these
12471 	 * values into the CC and place in here the old values
12472 	 * so we have a restoral. Then we will set the flag
12473 	 * rc_pacing_cc_set. That way whenever we turn off pacing
12474 	 * or switch off this stack, we will know to go restore
12475 	 * the saved values.
12476 	 */
12477 	rack->r_ctl.rc_saved_beta.beta = V_newreno_beta_ecn;
12478 	rack->r_ctl.rc_saved_beta.beta_ecn = V_newreno_beta_ecn;
12479 	/* We want abe like behavior as well */
12480 	rack->r_ctl.rc_saved_beta.newreno_flags |= CC_NEWRENO_BETA_ECN_ENABLED;
12481 	rack->r_ctl.rc_reorder_fade = rack_reorder_fade;
12482 	rack->rc_allow_data_af_clo = rack_ignore_data_after_close;
12483 	rack->r_ctl.rc_tlp_threshold = rack_tlp_thresh;
12484 	rack->r_ctl.roundends = tp->snd_max;
12485 	if (use_rack_rr)
12486 		rack->use_rack_rr = 1;
12487 	if (V_tcp_delack_enabled)
12488 		tp->t_delayed_ack = 1;
12489 	else
12490 		tp->t_delayed_ack = 0;
12491 #ifdef TCP_ACCOUNTING
12492 	if (rack_tcp_accounting) {
12493 		tp->t_flags2 |= TF2_TCP_ACCOUNTING;
12494 	}
12495 #endif
12496 	if (rack_enable_shared_cwnd)
12497 		rack->rack_enable_scwnd = 1;
12498 	rack->rc_user_set_max_segs = rack_hptsi_segments;
12499 	rack->rc_force_max_seg = 0;
12500 	if (rack_use_imac_dack)
12501 		rack->rc_dack_mode = 1;
12502 	TAILQ_INIT(&rack->r_ctl.opt_list);
12503 	rack->r_ctl.rc_reorder_shift = rack_reorder_thresh;
12504 	rack->r_ctl.rc_pkt_delay = rack_pkt_delay;
12505 	rack->r_ctl.rc_tlp_cwnd_reduce = rack_lower_cwnd_at_tlp;
12506 	rack->r_ctl.rc_lowest_us_rtt = 0xffffffff;
12507 	rack->r_ctl.rc_highest_us_rtt = 0;
12508 	rack->r_ctl.bw_rate_cap = rack_bw_rate_cap;
12509 	rack->r_ctl.timer_slop = TICKS_2_USEC(tcp_rexmit_slop);
12510 	if (rack_use_cmp_acks)
12511 		rack->r_use_cmp_ack = 1;
12512 	if (rack_disable_prr)
12513 		rack->rack_no_prr = 1;
12514 	if (rack_gp_no_rec_chg)
12515 		rack->rc_gp_no_rec_chg = 1;
12516 	if (rack_pace_every_seg && tcp_can_enable_pacing()) {
12517 		rack->rc_always_pace = 1;
12518 		if (rack->use_fixed_rate || rack->gp_ready)
12519 			rack_set_cc_pacing(rack);
12520 	} else
12521 		rack->rc_always_pace = 0;
12522 	if (rack_enable_mqueue_for_nonpaced || rack->r_use_cmp_ack)
12523 		rack->r_mbuf_queue = 1;
12524 	else
12525 		rack->r_mbuf_queue = 0;
12526 	if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
12527 		tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
12528 	else
12529 		tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
12530 	rack_set_pace_segments(tp, rack, __LINE__, NULL);
12531 	if (rack_limits_scwnd)
12532 		rack->r_limit_scw = 1;
12533 	else
12534 		rack->r_limit_scw = 0;
12535 	rack->rc_labc = V_tcp_abc_l_var;
12536 	rack->r_ctl.rc_high_rwnd = tp->snd_wnd;
12537 	rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
12538 	rack->r_ctl.rc_rate_sample_method = rack_rate_sample_method;
12539 	rack->rack_tlp_threshold_use = rack_tlp_threshold_use;
12540 	rack->r_ctl.rc_prr_sendalot = rack_send_a_lot_in_prr;
12541 	rack->r_ctl.rc_min_to = rack_min_to;
12542 	microuptime(&rack->r_ctl.act_rcv_time);
12543 	rack->r_ctl.rc_last_time_decay = rack->r_ctl.act_rcv_time;
12544 	rack->rc_init_win = rack_default_init_window;
12545 	rack->r_ctl.rack_per_of_gp_ss = rack_per_of_gp_ss;
12546 	if (rack_hw_up_only)
12547 		rack->r_up_only = 1;
12548 	if (rack_do_dyn_mul) {
12549 		/* When dynamic adjustment is on CA needs to start at 100% */
12550 		rack->rc_gp_dyn_mul = 1;
12551 		if (rack_do_dyn_mul >= 100)
12552 			rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
12553 	} else
12554 		rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
12555 	rack->r_ctl.rack_per_of_gp_rec = rack_per_of_gp_rec;
12556 	rack->r_ctl.rack_per_of_gp_probertt = rack_per_of_gp_probertt;
12557 	rack->r_ctl.rc_tlp_rxt_last_time = tcp_tv_to_mssectick(&rack->r_ctl.act_rcv_time);
12558 	setup_time_filter_small(&rack->r_ctl.rc_gp_min_rtt, FILTER_TYPE_MIN,
12559 				rack_probertt_filter_life);
12560 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
12561 	rack->r_ctl.rc_lower_rtt_us_cts = us_cts;
12562 	rack->r_ctl.rc_time_of_last_probertt = us_cts;
12563 	rack->r_ctl.challenge_ack_ts = tcp_ts_getticks();
12564 	rack->r_ctl.rc_time_probertt_starts = 0;
12565 	if (rack_dsack_std_based & 0x1) {
12566 		/* Basically this means all rack timers are at least (srtt + 1/4 srtt) */
12567 		rack->rc_rack_tmr_std_based = 1;
12568 	}
12569 	if (rack_dsack_std_based & 0x2) {
12570 		/* Basically this means  rack timers are extended based on dsack by up to (2 * srtt) */
12571 		rack->rc_rack_use_dsack = 1;
12572 	}
12573 	/* We require at least one measurement, even if the sysctl is 0 */
12574 	if (rack_req_measurements)
12575 		rack->r_ctl.req_measurements = rack_req_measurements;
12576 	else
12577 		rack->r_ctl.req_measurements = 1;
12578 	if (rack_enable_hw_pacing)
12579 		rack->rack_hdw_pace_ena = 1;
12580 	if (rack_hw_rate_caps)
12581 		rack->r_rack_hw_rate_caps = 1;
12582 	/* Do we force on detection? */
12583 #ifdef NETFLIX_EXP_DETECTION
12584 	if (tcp_force_detection)
12585 		rack->do_detection = 1;
12586 	else
12587 #endif
12588 		rack->do_detection = 0;
12589 	if (rack_non_rxt_use_cr)
12590 		rack->rack_rec_nonrxt_use_cr = 1;
12591 	err = rack_init_fsb(tp, rack);
12592 	if (err) {
12593 		uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
12594 		tp->t_fb_ptr = NULL;
12595 		return (err);
12596 	}
12597 	if (tp->snd_una != tp->snd_max) {
12598 		/* Create a send map for the current outstanding data */
12599 		struct rack_sendmap *rsm;
12600 
12601 		rsm = rack_alloc(rack);
12602 		if (rsm == NULL) {
12603 			uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
12604 			tp->t_fb_ptr = NULL;
12605 			return (ENOMEM);
12606 		}
12607 		rsm->r_no_rtt_allowed = 1;
12608 		rsm->r_tim_lastsent[0] = rack_to_usec_ts(&rack->r_ctl.act_rcv_time);
12609 		rsm->r_rtr_cnt = 1;
12610 		rsm->r_rtr_bytes = 0;
12611 		if (tp->t_flags & TF_SENTFIN)
12612 			rsm->r_flags |= RACK_HAS_FIN;
12613 		rsm->r_end = tp->snd_max;
12614 		if (tp->snd_una == tp->iss) {
12615 			/* The data space is one beyond snd_una */
12616 			rsm->r_flags |= RACK_HAS_SYN;
12617 			rsm->r_start = tp->iss;
12618 			rsm->r_end = rsm->r_start + (tp->snd_max - tp->snd_una);
12619 		} else
12620 			rsm->r_start = tp->snd_una;
12621 		rsm->r_dupack = 0;
12622 		if (rack->rc_inp->inp_socket->so_snd.sb_mb != NULL) {
12623 			rsm->m = sbsndmbuf(&rack->rc_inp->inp_socket->so_snd, 0, &rsm->soff);
12624 			if (rsm->m)
12625 				rsm->orig_m_len = rsm->m->m_len;
12626 			else
12627 				rsm->orig_m_len = 0;
12628 		} else {
12629 			/*
12630 			 * This can happen if we have a stand-alone FIN or
12631 			 *  SYN.
12632 			 */
12633 			rsm->m = NULL;
12634 			rsm->orig_m_len = 0;
12635 			rsm->soff = 0;
12636 		}
12637 #ifndef INVARIANTS
12638 		(void)RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
12639 #else
12640 		insret = RB_INSERT(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
12641 		if (insret != NULL) {
12642 			panic("Insert in rb tree fails ret:%p rack:%p rsm:%p",
12643 			      insret, rack, rsm);
12644 		}
12645 #endif
12646 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_tmap, rsm, r_tnext);
12647 		rsm->r_in_tmap = 1;
12648 	}
12649 	/*
12650 	 * Timers in Rack are kept in microseconds so lets
12651 	 * convert any initial incoming variables
12652 	 * from ticks into usecs. Note that we
12653 	 * also change the values of t_srtt and t_rttvar, if
12654 	 * they are non-zero. They are kept with a 5
12655 	 * bit decimal so we have to carefully convert
12656 	 * these to get the full precision.
12657 	 */
12658 	rack_convert_rtts(tp);
12659 	tp->t_rttlow = TICKS_2_USEC(tp->t_rttlow);
12660 	if (rack_do_hystart) {
12661 		tp->ccv->flags |= CCF_HYSTART_ALLOWED;
12662 		if (rack_do_hystart > 1)
12663 			tp->ccv->flags |= CCF_HYSTART_CAN_SH_CWND;
12664 		if (rack_do_hystart > 2)
12665 			tp->ccv->flags |= CCF_HYSTART_CONS_SSTH;
12666 	}
12667 	if (rack_def_profile)
12668 		rack_set_profile(rack, rack_def_profile);
12669 	/* Cancel the GP measurement in progress */
12670 	tp->t_flags &= ~TF_GPUTINPROG;
12671 	if (SEQ_GT(tp->snd_max, tp->iss))
12672 		snt = tp->snd_max - tp->iss;
12673 	else
12674 		snt = 0;
12675 	iwin = rc_init_window(rack);
12676 	if (snt < iwin) {
12677 		/* We are not past the initial window
12678 		 * so we need to make sure cwnd is
12679 		 * correct.
12680 		 */
12681 		if (tp->snd_cwnd < iwin)
12682 			tp->snd_cwnd = iwin;
12683 		/*
12684 		 * If we are within the initial window
12685 		 * we want ssthresh to be unlimited. Setting
12686 		 * it to the rwnd (which the default stack does
12687 		 * and older racks) is not really a good idea
12688 		 * since we want to be in SS and grow both the
12689 		 * cwnd and the rwnd (via dynamic rwnd growth). If
12690 		 * we set it to the rwnd then as the peer grows its
12691 		 * rwnd we will be stuck in CA and never hit SS.
12692 		 *
12693 		 * Its far better to raise it up high (this takes the
12694 		 * risk that there as been a loss already, probably
12695 		 * we should have an indicator in all stacks of loss
12696 		 * but we don't), but considering the normal use this
12697 		 * is a risk worth taking. The consequences of not
12698 		 * hitting SS are far worse than going one more time
12699 		 * into it early on (before we have sent even a IW).
12700 		 * It is highly unlikely that we will have had a loss
12701 		 * before getting the IW out.
12702 		 */
12703 		tp->snd_ssthresh = 0xffffffff;
12704 	}
12705 	rack_stop_all_timers(tp);
12706 	/* Lets setup the fsb block */
12707 	rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
12708 	rack_log_rtt_shrinks(rack,  us_cts,  tp->t_rxtcur,
12709 			     __LINE__, RACK_RTTS_INIT);
12710 	return (0);
12711 }
12712 
12713 static int
12714 rack_handoff_ok(struct tcpcb *tp)
12715 {
12716 	if ((tp->t_state == TCPS_CLOSED) ||
12717 	    (tp->t_state == TCPS_LISTEN)) {
12718 		/* Sure no problem though it may not stick */
12719 		return (0);
12720 	}
12721 	if ((tp->t_state == TCPS_SYN_SENT) ||
12722 	    (tp->t_state == TCPS_SYN_RECEIVED)) {
12723 		/*
12724 		 * We really don't know if you support sack,
12725 		 * you have to get to ESTAB or beyond to tell.
12726 		 */
12727 		return (EAGAIN);
12728 	}
12729 	if ((tp->t_flags & TF_SENTFIN) && ((tp->snd_max - tp->snd_una) > 1)) {
12730 		/*
12731 		 * Rack will only send a FIN after all data is acknowledged.
12732 		 * So in this case we have more data outstanding. We can't
12733 		 * switch stacks until either all data and only the FIN
12734 		 * is left (in which case rack_init() now knows how
12735 		 * to deal with that) <or> all is acknowledged and we
12736 		 * are only left with incoming data, though why you
12737 		 * would want to switch to rack after all data is acknowledged
12738 		 * I have no idea (rrs)!
12739 		 */
12740 		return (EAGAIN);
12741 	}
12742 	if ((tp->t_flags & TF_SACK_PERMIT) || rack_sack_not_required){
12743 		return (0);
12744 	}
12745 	/*
12746 	 * If we reach here we don't do SACK on this connection so we can
12747 	 * never do rack.
12748 	 */
12749 	return (EINVAL);
12750 }
12751 
12752 
12753 static void
12754 rack_fini(struct tcpcb *tp, int32_t tcb_is_purged)
12755 {
12756 	if (tp->t_fb_ptr) {
12757 		struct tcp_rack *rack;
12758 		struct rack_sendmap *rsm, *nrsm;
12759 #ifdef INVARIANTS
12760 		struct rack_sendmap *rm;
12761 #endif
12762 
12763 		rack = (struct tcp_rack *)tp->t_fb_ptr;
12764 		if (tp->t_in_pkt) {
12765 			/*
12766 			 * It is unsafe to process the packets since a
12767 			 * reset may be lurking in them (its rare but it
12768 			 * can occur). If we were to find a RST, then we
12769 			 * would end up dropping the connection and the
12770 			 * INP lock, so when we return the caller (tcp_usrreq)
12771 			 * will blow up when it trys to unlock the inp.
12772 			 */
12773 			struct mbuf *save, *m;
12774 
12775 			m = tp->t_in_pkt;
12776 			tp->t_in_pkt = NULL;
12777 			tp->t_tail_pkt = NULL;
12778 			while (m) {
12779 				save = m->m_nextpkt;
12780 				m->m_nextpkt = NULL;
12781 				m_freem(m);
12782 				m = save;
12783 			}
12784 		}
12785 		tp->t_flags &= ~TF_FORCEDATA;
12786 #ifdef NETFLIX_SHARED_CWND
12787 		if (rack->r_ctl.rc_scw) {
12788 			uint32_t limit;
12789 
12790 			if (rack->r_limit_scw)
12791 				limit = max(1, rack->r_ctl.rc_lowest_us_rtt);
12792 			else
12793 				limit = 0;
12794 			tcp_shared_cwnd_free_full(tp, rack->r_ctl.rc_scw,
12795 						  rack->r_ctl.rc_scw_index,
12796 						  limit);
12797 			rack->r_ctl.rc_scw = NULL;
12798 		}
12799 #endif
12800 		if (rack->r_ctl.fsb.tcp_ip_hdr) {
12801 			free(rack->r_ctl.fsb.tcp_ip_hdr, M_TCPFSB);
12802 			rack->r_ctl.fsb.tcp_ip_hdr = NULL;
12803 			rack->r_ctl.fsb.th = NULL;
12804 		}
12805 		/* Convert back to ticks, with  */
12806 		if (tp->t_srtt > 1) {
12807 			uint32_t val, frac;
12808 
12809 			val = USEC_2_TICKS(tp->t_srtt);
12810 			frac = tp->t_srtt % (HPTS_USEC_IN_SEC / hz);
12811 			tp->t_srtt = val << TCP_RTT_SHIFT;
12812 			/*
12813 			 * frac is the fractional part here is left
12814 			 * over from converting to hz and shifting.
12815 			 * We need to convert this to the 5 bit
12816 			 * remainder.
12817 			 */
12818 			if (frac) {
12819 				if (hz == 1000) {
12820 					frac = (((uint64_t)frac *  (uint64_t)TCP_RTT_SCALE) / (uint64_t)HPTS_USEC_IN_MSEC);
12821 				} else {
12822 					frac = (((uint64_t)frac * (uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE) /(uint64_t)HPTS_USEC_IN_SEC);
12823 				}
12824 				tp->t_srtt += frac;
12825 			}
12826 		}
12827 		if (tp->t_rttvar) {
12828 			uint32_t val, frac;
12829 
12830 			val = USEC_2_TICKS(tp->t_rttvar);
12831 			frac = tp->t_srtt % (HPTS_USEC_IN_SEC / hz);
12832 			tp->t_rttvar = val <<  TCP_RTTVAR_SHIFT;
12833 			/*
12834 			 * frac is the fractional part here is left
12835 			 * over from converting to hz and shifting.
12836 			 * We need to convert this to the 5 bit
12837 			 * remainder.
12838 			 */
12839 			if (frac) {
12840 				if (hz == 1000) {
12841 					frac = (((uint64_t)frac *  (uint64_t)TCP_RTT_SCALE) / (uint64_t)HPTS_USEC_IN_MSEC);
12842 				} else {
12843 					frac = (((uint64_t)frac * (uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE) /(uint64_t)HPTS_USEC_IN_SEC);
12844 				}
12845 				tp->t_rttvar += frac;
12846 			}
12847 		}
12848 		tp->t_rxtcur = USEC_2_TICKS(tp->t_rxtcur);
12849 		tp->t_rttlow = USEC_2_TICKS(tp->t_rttlow);
12850 		if (rack->rc_always_pace) {
12851 			tcp_decrement_paced_conn();
12852 			rack_undo_cc_pacing(rack);
12853 			rack->rc_always_pace = 0;
12854 		}
12855 		/* Clean up any options if they were not applied */
12856 		while (!TAILQ_EMPTY(&rack->r_ctl.opt_list)) {
12857 			struct deferred_opt_list *dol;
12858 
12859 			dol = TAILQ_FIRST(&rack->r_ctl.opt_list);
12860 			TAILQ_REMOVE(&rack->r_ctl.opt_list, dol, next);
12861 			free(dol, M_TCPDO);
12862 		}
12863 		/* rack does not use force data but other stacks may clear it */
12864 		if (rack->r_ctl.crte != NULL) {
12865 			tcp_rel_pacing_rate(rack->r_ctl.crte, tp);
12866 			rack->rack_hdrw_pacing = 0;
12867 			rack->r_ctl.crte = NULL;
12868 		}
12869 #ifdef TCP_BLACKBOX
12870 		tcp_log_flowend(tp);
12871 #endif
12872 		RB_FOREACH_SAFE(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree, nrsm) {
12873 #ifndef INVARIANTS
12874 			(void)RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
12875 #else
12876 			rm = RB_REMOVE(rack_rb_tree_head, &rack->r_ctl.rc_mtree, rsm);
12877 			if (rm != rsm) {
12878 				panic("At fini, rack:%p rsm:%p rm:%p",
12879 				      rack, rsm, rm);
12880 			}
12881 #endif
12882 			uma_zfree(rack_zone, rsm);
12883 		}
12884 		rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
12885 		while (rsm) {
12886 			TAILQ_REMOVE(&rack->r_ctl.rc_free, rsm, r_tnext);
12887 			uma_zfree(rack_zone, rsm);
12888 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_free);
12889 		}
12890 		rack->rc_free_cnt = 0;
12891 		uma_zfree(rack_pcb_zone, tp->t_fb_ptr);
12892 		tp->t_fb_ptr = NULL;
12893 	}
12894 	if (tp->t_inpcb) {
12895 		tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
12896 		tp->t_inpcb->inp_flags2 &= ~INP_MBUF_QUEUE_READY;
12897 		tp->t_inpcb->inp_flags2 &= ~INP_DONT_SACK_QUEUE;
12898 		tp->t_inpcb->inp_flags2 &= ~INP_MBUF_ACKCMP;
12899 		/* Cancel the GP measurement in progress */
12900 		tp->t_flags &= ~TF_GPUTINPROG;
12901 		tp->t_inpcb->inp_flags2 &= ~INP_MBUF_L_ACKS;
12902 	}
12903 	/* Make sure snd_nxt is correctly set */
12904 	tp->snd_nxt = tp->snd_max;
12905 }
12906 
12907 static void
12908 rack_set_state(struct tcpcb *tp, struct tcp_rack *rack)
12909 {
12910 	if ((rack->r_state == TCPS_CLOSED) && (tp->t_state != TCPS_CLOSED)) {
12911 		rack->r_is_v6 = (tp->t_inpcb->inp_vflag & INP_IPV6) != 0;
12912 	}
12913 	switch (tp->t_state) {
12914 	case TCPS_SYN_SENT:
12915 		rack->r_state = TCPS_SYN_SENT;
12916 		rack->r_substate = rack_do_syn_sent;
12917 		break;
12918 	case TCPS_SYN_RECEIVED:
12919 		rack->r_state = TCPS_SYN_RECEIVED;
12920 		rack->r_substate = rack_do_syn_recv;
12921 		break;
12922 	case TCPS_ESTABLISHED:
12923 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
12924 		rack->r_state = TCPS_ESTABLISHED;
12925 		rack->r_substate = rack_do_established;
12926 		break;
12927 	case TCPS_CLOSE_WAIT:
12928 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
12929 		rack->r_state = TCPS_CLOSE_WAIT;
12930 		rack->r_substate = rack_do_close_wait;
12931 		break;
12932 	case TCPS_FIN_WAIT_1:
12933 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
12934 		rack->r_state = TCPS_FIN_WAIT_1;
12935 		rack->r_substate = rack_do_fin_wait_1;
12936 		break;
12937 	case TCPS_CLOSING:
12938 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
12939 		rack->r_state = TCPS_CLOSING;
12940 		rack->r_substate = rack_do_closing;
12941 		break;
12942 	case TCPS_LAST_ACK:
12943 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
12944 		rack->r_state = TCPS_LAST_ACK;
12945 		rack->r_substate = rack_do_lastack;
12946 		break;
12947 	case TCPS_FIN_WAIT_2:
12948 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
12949 		rack->r_state = TCPS_FIN_WAIT_2;
12950 		rack->r_substate = rack_do_fin_wait_2;
12951 		break;
12952 	case TCPS_LISTEN:
12953 	case TCPS_CLOSED:
12954 	case TCPS_TIME_WAIT:
12955 	default:
12956 		break;
12957 	};
12958 	if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
12959 		rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
12960 
12961 }
12962 
12963 static void
12964 rack_timer_audit(struct tcpcb *tp, struct tcp_rack *rack, struct sockbuf *sb)
12965 {
12966 	/*
12967 	 * We received an ack, and then did not
12968 	 * call send or were bounced out due to the
12969 	 * hpts was running. Now a timer is up as well, is
12970 	 * it the right timer?
12971 	 */
12972 	struct rack_sendmap *rsm;
12973 	int tmr_up;
12974 
12975 	tmr_up = rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
12976 	if (rack->rc_in_persist && (tmr_up == PACE_TMR_PERSIT))
12977 		return;
12978 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
12979 	if (((rsm == NULL) || (tp->t_state < TCPS_ESTABLISHED)) &&
12980 	    (tmr_up == PACE_TMR_RXT)) {
12981 		/* Should be an RXT */
12982 		return;
12983 	}
12984 	if (rsm == NULL) {
12985 		/* Nothing outstanding? */
12986 		if (tp->t_flags & TF_DELACK) {
12987 			if (tmr_up == PACE_TMR_DELACK)
12988 				/* We are supposed to have delayed ack up and we do */
12989 				return;
12990 		} else if (sbavail(&tp->t_inpcb->inp_socket->so_snd) && (tmr_up == PACE_TMR_RXT)) {
12991 			/*
12992 			 * if we hit enobufs then we would expect the possibility
12993 			 * of nothing outstanding and the RXT up (and the hptsi timer).
12994 			 */
12995 			return;
12996 		} else if (((V_tcp_always_keepalive ||
12997 			     rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
12998 			    (tp->t_state <= TCPS_CLOSING)) &&
12999 			   (tmr_up == PACE_TMR_KEEP) &&
13000 			   (tp->snd_max == tp->snd_una)) {
13001 			/* We should have keep alive up and we do */
13002 			return;
13003 		}
13004 	}
13005 	if (SEQ_GT(tp->snd_max, tp->snd_una) &&
13006 		   ((tmr_up == PACE_TMR_TLP) ||
13007 		    (tmr_up == PACE_TMR_RACK) ||
13008 		    (tmr_up == PACE_TMR_RXT))) {
13009 		/*
13010 		 * Either a Rack, TLP or RXT is fine if  we
13011 		 * have outstanding data.
13012 		 */
13013 		return;
13014 	} else if (tmr_up == PACE_TMR_DELACK) {
13015 		/*
13016 		 * If the delayed ack was going to go off
13017 		 * before the rtx/tlp/rack timer were going to
13018 		 * expire, then that would be the timer in control.
13019 		 * Note we don't check the time here trusting the
13020 		 * code is correct.
13021 		 */
13022 		return;
13023 	}
13024 	/*
13025 	 * Ok the timer originally started is not what we want now.
13026 	 * We will force the hpts to be stopped if any, and restart
13027 	 * with the slot set to what was in the saved slot.
13028 	 */
13029 	if (tcp_in_hpts(rack->rc_inp)) {
13030 		if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
13031 			uint32_t us_cts;
13032 
13033 			us_cts = tcp_get_usecs(NULL);
13034 			if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
13035 				rack->r_early = 1;
13036 				rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
13037 			}
13038 			rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
13039 		}
13040 		tcp_hpts_remove(tp->t_inpcb);
13041 	}
13042 	rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13043 	rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
13044 }
13045 
13046 
13047 static void
13048 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)
13049 {
13050 	if ((SEQ_LT(tp->snd_wl1, seq) ||
13051 	    (tp->snd_wl1 == seq && (SEQ_LT(tp->snd_wl2, ack) ||
13052 	    (tp->snd_wl2 == ack && tiwin > tp->snd_wnd))))) {
13053 		/* keep track of pure window updates */
13054 		if ((tp->snd_wl2 == ack) && (tiwin > tp->snd_wnd))
13055 			KMOD_TCPSTAT_INC(tcps_rcvwinupd);
13056 		tp->snd_wnd = tiwin;
13057 		rack_validate_fo_sendwin_up(tp, rack);
13058 		tp->snd_wl1 = seq;
13059 		tp->snd_wl2 = ack;
13060 		if (tp->snd_wnd > tp->max_sndwnd)
13061 			tp->max_sndwnd = tp->snd_wnd;
13062 	    rack->r_wanted_output = 1;
13063 	} else if ((tp->snd_wl2 == ack) && (tiwin < tp->snd_wnd)) {
13064 		tp->snd_wnd = tiwin;
13065 		rack_validate_fo_sendwin_up(tp, rack);
13066 		tp->snd_wl1 = seq;
13067 		tp->snd_wl2 = ack;
13068 	} else {
13069 		/* Not a valid win update */
13070 		return;
13071 	}
13072 	if (tp->snd_wnd > tp->max_sndwnd)
13073 		tp->max_sndwnd = tp->snd_wnd;
13074 	if (tp->snd_wnd < (tp->snd_max - high_seq)) {
13075 		/* The peer collapsed the window */
13076 		rack_collapsed_window(rack);
13077 	} else if (rack->rc_has_collapsed)
13078 		rack_un_collapse_window(rack);
13079 	/* Do we exit persists? */
13080 	if ((rack->rc_in_persist != 0) &&
13081 	    (tp->snd_wnd >= min((rack->r_ctl.rc_high_rwnd/2),
13082 				rack->r_ctl.rc_pace_min_segs))) {
13083 		rack_exit_persist(tp, rack, cts);
13084 	}
13085 	/* Do we enter persists? */
13086 	if ((rack->rc_in_persist == 0) &&
13087 	    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), rack->r_ctl.rc_pace_min_segs)) &&
13088 	    TCPS_HAVEESTABLISHED(tp->t_state) &&
13089 	    ((tp->snd_max == tp->snd_una) || rack->rc_has_collapsed) &&
13090 	    sbavail(&tp->t_inpcb->inp_socket->so_snd) &&
13091 	    (sbavail(&tp->t_inpcb->inp_socket->so_snd) > tp->snd_wnd)) {
13092 		/*
13093 		 * Here the rwnd is less than
13094 		 * the pacing size, we are established,
13095 		 * nothing is outstanding, and there is
13096 		 * data to send. Enter persists.
13097 		 */
13098 		rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
13099 	}
13100 }
13101 
13102 static void
13103 rack_log_input_packet(struct tcpcb *tp, struct tcp_rack *rack, struct tcp_ackent *ae, int ackval, uint32_t high_seq)
13104 {
13105 
13106 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
13107 		union tcp_log_stackspecific log;
13108 		struct timeval ltv;
13109 		char tcp_hdr_buf[60];
13110 		struct tcphdr *th;
13111 		struct timespec ts;
13112 		uint32_t orig_snd_una;
13113 		uint8_t xx = 0;
13114 
13115 #ifdef NETFLIX_HTTP_LOGGING
13116 		struct http_sendfile_track *http_req;
13117 
13118 		if (SEQ_GT(ae->ack, tp->snd_una)) {
13119 			http_req = tcp_http_find_req_for_seq(tp, (ae->ack-1));
13120 		} else {
13121 			http_req = tcp_http_find_req_for_seq(tp, ae->ack);
13122 		}
13123 #endif
13124 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
13125 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
13126 		if (rack->rack_no_prr == 0)
13127 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
13128 		else
13129 			log.u_bbr.flex1 = 0;
13130 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
13131 		log.u_bbr.use_lt_bw <<= 1;
13132 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
13133 		log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
13134 		log.u_bbr.inflight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
13135 		log.u_bbr.pkts_out = tp->t_maxseg;
13136 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
13137 		log.u_bbr.flex7 = 1;
13138 		log.u_bbr.lost = ae->flags;
13139 		log.u_bbr.cwnd_gain = ackval;
13140 		log.u_bbr.pacing_gain = 0x2;
13141 		if (ae->flags & TSTMP_HDWR) {
13142 			/* Record the hardware timestamp if present */
13143 			log.u_bbr.flex3 = M_TSTMP;
13144 			ts.tv_sec = ae->timestamp / 1000000000;
13145 			ts.tv_nsec = ae->timestamp % 1000000000;
13146 			ltv.tv_sec = ts.tv_sec;
13147 			ltv.tv_usec = ts.tv_nsec / 1000;
13148 			log.u_bbr.lt_epoch = tcp_tv_to_usectick(&ltv);
13149 		} else if (ae->flags & TSTMP_LRO) {
13150 			/* Record the LRO the arrival timestamp */
13151 			log.u_bbr.flex3 = M_TSTMP_LRO;
13152 			ts.tv_sec = ae->timestamp / 1000000000;
13153 			ts.tv_nsec = ae->timestamp % 1000000000;
13154 			ltv.tv_sec = ts.tv_sec;
13155 			ltv.tv_usec = ts.tv_nsec / 1000;
13156 			log.u_bbr.flex5 = tcp_tv_to_usectick(&ltv);
13157 		}
13158 		log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
13159 		/* Log the rcv time */
13160 		log.u_bbr.delRate = ae->timestamp;
13161 #ifdef NETFLIX_HTTP_LOGGING
13162 		log.u_bbr.applimited = tp->t_http_closed;
13163 		log.u_bbr.applimited <<= 8;
13164 		log.u_bbr.applimited |= tp->t_http_open;
13165 		log.u_bbr.applimited <<= 8;
13166 		log.u_bbr.applimited |= tp->t_http_req;
13167 		if (http_req) {
13168 			/* Copy out any client req info */
13169 			/* seconds */
13170 			log.u_bbr.pkt_epoch = (http_req->localtime / HPTS_USEC_IN_SEC);
13171 			/* useconds */
13172 			log.u_bbr.delivered = (http_req->localtime % HPTS_USEC_IN_SEC);
13173 			log.u_bbr.rttProp = http_req->timestamp;
13174 			log.u_bbr.cur_del_rate = http_req->start;
13175 			if (http_req->flags & TCP_HTTP_TRACK_FLG_OPEN) {
13176 				log.u_bbr.flex8 |= 1;
13177 			} else {
13178 				log.u_bbr.flex8 |= 2;
13179 				log.u_bbr.bw_inuse = http_req->end;
13180 			}
13181 			log.u_bbr.flex6 = http_req->start_seq;
13182 			if (http_req->flags & TCP_HTTP_TRACK_FLG_COMP) {
13183 				log.u_bbr.flex8 |= 4;
13184 				log.u_bbr.epoch = http_req->end_seq;
13185 			}
13186 		}
13187 #endif
13188 		memset(tcp_hdr_buf, 0, sizeof(tcp_hdr_buf));
13189 		th = (struct tcphdr *)tcp_hdr_buf;
13190 		th->th_seq = ae->seq;
13191 		th->th_ack = ae->ack;
13192 		th->th_win = ae->win;
13193 		/* Now fill in the ports */
13194 		th->th_sport = tp->t_inpcb->inp_fport;
13195 		th->th_dport = tp->t_inpcb->inp_lport;
13196 		tcp_set_flags(th, ae->flags);
13197 		/* Now do we have a timestamp option? */
13198 		if (ae->flags & HAS_TSTMP) {
13199 			u_char *cp;
13200 			uint32_t val;
13201 
13202 			th->th_off = ((sizeof(struct tcphdr) + TCPOLEN_TSTAMP_APPA) >> 2);
13203 			cp = (u_char *)(th + 1);
13204 			*cp = TCPOPT_NOP;
13205 			cp++;
13206 			*cp = TCPOPT_NOP;
13207 			cp++;
13208 			*cp = TCPOPT_TIMESTAMP;
13209 			cp++;
13210 			*cp = TCPOLEN_TIMESTAMP;
13211 			cp++;
13212 			val = htonl(ae->ts_value);
13213 			bcopy((char *)&val,
13214 			      (char *)cp, sizeof(uint32_t));
13215 			val = htonl(ae->ts_echo);
13216 			bcopy((char *)&val,
13217 			      (char *)(cp + 4), sizeof(uint32_t));
13218 		} else
13219 			th->th_off = (sizeof(struct tcphdr) >> 2);
13220 
13221 		/*
13222 		 * For sane logging we need to play a little trick.
13223 		 * If the ack were fully processed we would have moved
13224 		 * snd_una to high_seq, but since compressed acks are
13225 		 * processed in two phases, at this point (logging) snd_una
13226 		 * won't be advanced. So we would see multiple acks showing
13227 		 * the advancement. We can prevent that by "pretending" that
13228 		 * snd_una was advanced and then un-advancing it so that the
13229 		 * logging code has the right value for tlb_snd_una.
13230 		 */
13231 		if (tp->snd_una != high_seq) {
13232 			orig_snd_una = tp->snd_una;
13233 			tp->snd_una = high_seq;
13234 			xx = 1;
13235 		} else
13236 			xx = 0;
13237 		TCP_LOG_EVENTP(tp, th,
13238 			       &tp->t_inpcb->inp_socket->so_rcv,
13239 			       &tp->t_inpcb->inp_socket->so_snd, TCP_LOG_IN, 0,
13240 			       0, &log, true, &ltv);
13241 		if (xx) {
13242 			tp->snd_una = orig_snd_una;
13243 		}
13244 	}
13245 
13246 }
13247 
13248 static void
13249 rack_handle_probe_response(struct tcp_rack *rack, uint32_t tiwin, uint32_t us_cts)
13250 {
13251 	uint32_t us_rtt;
13252 	/*
13253 	 * A persist or keep-alive was forced out, update our
13254 	 * min rtt time. Note now worry about lost responses.
13255 	 * When a subsequent keep-alive or persist times out
13256 	 * and forced_ack is still on, then the last probe
13257 	 * was not responded to. In such cases we have a
13258 	 * sysctl that controls the behavior. Either we apply
13259 	 * the rtt but with reduced confidence (0). Or we just
13260 	 * plain don't apply the rtt estimate. Having data flow
13261 	 * will clear the probe_not_answered flag i.e. cum-ack
13262 	 * move forward <or> exiting and reentering persists.
13263 	 */
13264 
13265 	rack->forced_ack = 0;
13266 	rack->rc_tp->t_rxtshift = 0;
13267 	if ((rack->rc_in_persist &&
13268 	     (tiwin == rack->rc_tp->snd_wnd)) ||
13269 	    (rack->rc_in_persist == 0)) {
13270 		/*
13271 		 * In persists only apply the RTT update if this is
13272 		 * a response to our window probe. And that
13273 		 * means the rwnd sent must match the current
13274 		 * snd_wnd. If it does not, then we got a
13275 		 * window update ack instead. For keepalive
13276 		 * we allow the answer no matter what the window.
13277 		 *
13278 		 * Note that if the probe_not_answered is set then
13279 		 * the forced_ack_ts is the oldest one i.e. the first
13280 		 * probe sent that might have been lost. This assures
13281 		 * us that if we do calculate an RTT it is longer not
13282 		 * some short thing.
13283 		 */
13284 		if (rack->rc_in_persist)
13285 			counter_u64_add(rack_persists_acks, 1);
13286 		us_rtt = us_cts - rack->r_ctl.forced_ack_ts;
13287 		if (us_rtt == 0)
13288 			us_rtt = 1;
13289 		if (rack->probe_not_answered == 0) {
13290 			rack_apply_updated_usrtt(rack, us_rtt, us_cts);
13291 			tcp_rack_xmit_timer(rack, us_rtt, 0, us_rtt, 3, NULL, 1);
13292 		} else {
13293 			/* We have a retransmitted probe here too */
13294 			if (rack_apply_rtt_with_reduced_conf) {
13295 				rack_apply_updated_usrtt(rack, us_rtt, us_cts);
13296 				tcp_rack_xmit_timer(rack, us_rtt, 0, us_rtt, 0, NULL, 1);
13297 			}
13298 		}
13299 	}
13300 }
13301 
13302 static int
13303 rack_do_compressed_ack_processing(struct tcpcb *tp, struct socket *so, struct mbuf *m, int nxt_pkt, struct timeval *tv)
13304 {
13305 	/*
13306 	 * Handle a "special" compressed ack mbuf. Each incoming
13307 	 * ack has only four possible dispositions:
13308 	 *
13309 	 * A) It moves the cum-ack forward
13310 	 * B) It is behind the cum-ack.
13311 	 * C) It is a window-update ack.
13312 	 * D) It is a dup-ack.
13313 	 *
13314 	 * Note that we can have between 1 -> TCP_COMP_ACK_ENTRIES
13315 	 * in the incoming mbuf. We also need to still pay attention
13316 	 * to nxt_pkt since there may be another packet after this
13317 	 * one.
13318 	 */
13319 #ifdef TCP_ACCOUNTING
13320 	uint64_t ts_val;
13321 	uint64_t rdstc;
13322 #endif
13323 	int segsiz;
13324 	struct timespec ts;
13325 	struct tcp_rack *rack;
13326 	struct tcp_ackent *ae;
13327 	uint32_t tiwin, ms_cts, cts, acked, acked_amount, high_seq, win_seq, the_win, win_upd_ack;
13328 	int cnt, i, did_out, ourfinisacked = 0;
13329 	struct tcpopt to_holder, *to = NULL;
13330 #ifdef TCP_ACCOUNTING
13331 	int win_up_req = 0;
13332 #endif
13333 	int nsegs = 0;
13334 	int under_pacing = 1;
13335 	int recovery = 0;
13336 #ifdef TCP_ACCOUNTING
13337 	sched_pin();
13338 #endif
13339 	rack = (struct tcp_rack *)tp->t_fb_ptr;
13340 	if (rack->gp_ready &&
13341 	    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT))
13342 		under_pacing = 0;
13343 	else
13344 		under_pacing = 1;
13345 
13346 	if (rack->r_state != tp->t_state)
13347 		rack_set_state(tp, rack);
13348 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
13349 	    (tp->t_flags & TF_GPUTINPROG)) {
13350 		/*
13351 		 * We have a goodput in progress
13352 		 * and we have entered a late state.
13353 		 * Do we have enough data in the sb
13354 		 * to handle the GPUT request?
13355 		 */
13356 		uint32_t bytes;
13357 
13358 		bytes = tp->gput_ack - tp->gput_seq;
13359 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
13360 			bytes += tp->gput_seq - tp->snd_una;
13361 		if (bytes > sbavail(&tp->t_inpcb->inp_socket->so_snd)) {
13362 			/*
13363 			 * There are not enough bytes in the socket
13364 			 * buffer that have been sent to cover this
13365 			 * measurement. Cancel it.
13366 			 */
13367 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
13368 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
13369 						   tp->gput_seq,
13370 						   0, 0, 18, __LINE__, NULL, 0);
13371 			tp->t_flags &= ~TF_GPUTINPROG;
13372 		}
13373 	}
13374 	to = &to_holder;
13375 	to->to_flags = 0;
13376 	KASSERT((m->m_len >= sizeof(struct tcp_ackent)),
13377 		("tp:%p m_cmpack:%p with invalid len:%u", tp, m, m->m_len));
13378 	cnt = m->m_len / sizeof(struct tcp_ackent);
13379 	counter_u64_add(rack_multi_single_eq, cnt);
13380 	high_seq = tp->snd_una;
13381 	the_win = tp->snd_wnd;
13382 	win_seq = tp->snd_wl1;
13383 	win_upd_ack = tp->snd_wl2;
13384 	cts = tcp_tv_to_usectick(tv);
13385 	ms_cts = tcp_tv_to_mssectick(tv);
13386 	rack->r_ctl.rc_rcvtime = cts;
13387 	segsiz = ctf_fixed_maxseg(tp);
13388 	if ((rack->rc_gp_dyn_mul) &&
13389 	    (rack->use_fixed_rate == 0) &&
13390 	    (rack->rc_always_pace)) {
13391 		/* Check in on probertt */
13392 		rack_check_probe_rtt(rack, cts);
13393 	}
13394 	for (i = 0; i < cnt; i++) {
13395 #ifdef TCP_ACCOUNTING
13396 		ts_val = get_cyclecount();
13397 #endif
13398 		rack_clear_rate_sample(rack);
13399 		ae = ((mtod(m, struct tcp_ackent *)) + i);
13400 		/* Setup the window */
13401 		tiwin = ae->win << tp->snd_scale;
13402 		if (tiwin > rack->r_ctl.rc_high_rwnd)
13403 			rack->r_ctl.rc_high_rwnd = tiwin;
13404 		/* figure out the type of ack */
13405 		if (SEQ_LT(ae->ack, high_seq)) {
13406 			/* Case B*/
13407 			ae->ack_val_set = ACK_BEHIND;
13408 		} else if (SEQ_GT(ae->ack, high_seq)) {
13409 			/* Case A */
13410 			ae->ack_val_set = ACK_CUMACK;
13411 		} else if ((tiwin == the_win) && (rack->rc_in_persist == 0)){
13412 			/* Case D */
13413 			ae->ack_val_set = ACK_DUPACK;
13414 		} else {
13415 			/* Case C */
13416 			ae->ack_val_set = ACK_RWND;
13417 		}
13418 		rack_log_input_packet(tp, rack, ae, ae->ack_val_set, high_seq);
13419 		/* Validate timestamp */
13420 		if (ae->flags & HAS_TSTMP) {
13421 			/* Setup for a timestamp */
13422 			to->to_flags = TOF_TS;
13423 			ae->ts_echo -= tp->ts_offset;
13424 			to->to_tsecr = ae->ts_echo;
13425 			to->to_tsval = ae->ts_value;
13426 			/*
13427 			 * If echoed timestamp is later than the current time, fall back to
13428 			 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
13429 			 * were used when this connection was established.
13430 			 */
13431 			if (TSTMP_GT(ae->ts_echo, ms_cts))
13432 				to->to_tsecr = 0;
13433 			if (tp->ts_recent &&
13434 			    TSTMP_LT(ae->ts_value, tp->ts_recent)) {
13435 				if (ctf_ts_check_ac(tp, (ae->flags & 0xff))) {
13436 #ifdef TCP_ACCOUNTING
13437 					rdstc = get_cyclecount();
13438 					if (rdstc > ts_val) {
13439 						counter_u64_add(tcp_proc_time[ae->ack_val_set] ,
13440 								(rdstc - ts_val));
13441 						if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13442 							tp->tcp_proc_time[ae->ack_val_set] += (rdstc - ts_val);
13443 						}
13444 					}
13445 #endif
13446 					continue;
13447 				}
13448 			}
13449 			if (SEQ_LEQ(ae->seq, tp->last_ack_sent) &&
13450 			    SEQ_LEQ(tp->last_ack_sent, ae->seq)) {
13451 				tp->ts_recent_age = tcp_ts_getticks();
13452 				tp->ts_recent = ae->ts_value;
13453 			}
13454 		} else {
13455 			/* Setup for a no options */
13456 			to->to_flags = 0;
13457 		}
13458 		/* Update the rcv time and perform idle reduction possibly */
13459 		if  (tp->t_idle_reduce &&
13460 		     (tp->snd_max == tp->snd_una) &&
13461 		     (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
13462 			counter_u64_add(rack_input_idle_reduces, 1);
13463 			rack_cc_after_idle(rack, tp);
13464 		}
13465 		tp->t_rcvtime = ticks;
13466 		/* Now what about ECN? */
13467 		if (tcp_ecn_input_segment(tp, ae->flags, ae->codepoint))
13468 			rack_cong_signal(tp, CC_ECN, ae->ack, __LINE__);
13469 #ifdef TCP_ACCOUNTING
13470 		/* Count for the specific type of ack in */
13471 		counter_u64_add(tcp_cnt_counters[ae->ack_val_set], 1);
13472 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13473 			tp->tcp_cnt_counters[ae->ack_val_set]++;
13474 		}
13475 #endif
13476 		/*
13477 		 * Note how we could move up these in the determination
13478 		 * above, but we don't so that way the timestamp checks (and ECN)
13479 		 * is done first before we do any processing on the ACK.
13480 		 * The non-compressed path through the code has this
13481 		 * weakness (noted by @jtl) that it actually does some
13482 		 * processing before verifying the timestamp information.
13483 		 * We don't take that path here which is why we set
13484 		 * the ack_val_set first, do the timestamp and ecn
13485 		 * processing, and then look at what we have setup.
13486 		 */
13487 		if (ae->ack_val_set == ACK_BEHIND) {
13488 			/*
13489 			 * Case B flag reordering, if window is not closed
13490 			 * or it could be a keep-alive or persists
13491 			 */
13492 			if (SEQ_LT(ae->ack, tp->snd_una) && (sbspace(&so->so_rcv) > segsiz)) {
13493 				rack->r_ctl.rc_reorder_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
13494 			}
13495 		} else if (ae->ack_val_set == ACK_DUPACK) {
13496 			/* Case D */
13497 			rack_strike_dupack(rack);
13498 		} else if (ae->ack_val_set == ACK_RWND) {
13499 			/* Case C */
13500 			if ((ae->flags & TSTMP_LRO) || (ae->flags & TSTMP_HDWR)) {
13501 				ts.tv_sec = ae->timestamp / 1000000000;
13502 				ts.tv_nsec = ae->timestamp % 1000000000;
13503 				rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
13504 				rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
13505 			} else {
13506 				rack->r_ctl.act_rcv_time = *tv;
13507 			}
13508 			if (rack->forced_ack) {
13509 				rack_handle_probe_response(rack, tiwin,
13510 							   tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time));
13511 			}
13512 #ifdef TCP_ACCOUNTING
13513 			win_up_req = 1;
13514 #endif
13515 			win_upd_ack = ae->ack;
13516 			win_seq = ae->seq;
13517 			the_win = tiwin;
13518 			rack_do_win_updates(tp, rack, the_win, win_seq, win_upd_ack, cts, high_seq);
13519 		} else {
13520 			/* Case A */
13521 			if (SEQ_GT(ae->ack, tp->snd_max)) {
13522 				/*
13523 				 * We just send an ack since the incoming
13524 				 * ack is beyond the largest seq we sent.
13525 				 */
13526 				if ((tp->t_flags & TF_ACKNOW) == 0) {
13527 					ctf_ack_war_checks(tp, &rack->r_ctl.challenge_ack_ts, &rack->r_ctl.challenge_ack_cnt);
13528 					if (tp->t_flags && TF_ACKNOW)
13529 						rack->r_wanted_output = 1;
13530 				}
13531 			} else {
13532 				nsegs++;
13533 				/* If the window changed setup to update */
13534 				if (tiwin != tp->snd_wnd) {
13535 					win_upd_ack = ae->ack;
13536 					win_seq = ae->seq;
13537 					the_win = tiwin;
13538 					rack_do_win_updates(tp, rack, the_win, win_seq, win_upd_ack, cts, high_seq);
13539 				}
13540 #ifdef TCP_ACCOUNTING
13541 				/* Account for the acks */
13542 				if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13543 					tp->tcp_cnt_counters[CNT_OF_ACKS_IN] += (((ae->ack - high_seq) + segsiz - 1) / segsiz);
13544 				}
13545 				counter_u64_add(tcp_cnt_counters[CNT_OF_ACKS_IN],
13546 						(((ae->ack - high_seq) + segsiz - 1) / segsiz));
13547 #endif
13548 				high_seq = ae->ack;
13549 				if (rack_verbose_logging && (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
13550 					union tcp_log_stackspecific log;
13551 					struct timeval tv;
13552 
13553 					memset(&log.u_bbr, 0, sizeof(log.u_bbr));
13554 					log.u_bbr.timeStamp = tcp_get_usecs(&tv);
13555 					log.u_bbr.flex1 = high_seq;
13556 					log.u_bbr.flex2 = rack->r_ctl.roundends;
13557 					log.u_bbr.flex3 = rack->r_ctl.current_round;
13558 					log.u_bbr.rttProp = (uint64_t)CC_ALGO(tp)->newround;
13559 					log.u_bbr.flex8 = 8;
13560 					tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
13561 						       0, &log, false, NULL, NULL, 0, &tv);
13562 				}
13563 				/*
13564 				 * The draft (v3) calls for us to use SEQ_GEQ, but that
13565 				 * causes issues when we are just going app limited. Lets
13566 				 * instead use SEQ_GT <or> where its equal but more data
13567 				 * is outstanding.
13568 				 */
13569 				if ((SEQ_GT(high_seq, rack->r_ctl.roundends)) ||
13570 				    ((high_seq == rack->r_ctl.roundends) &&
13571 				     SEQ_GT(tp->snd_max, tp->snd_una))) {
13572 					rack->r_ctl.current_round++;
13573 					rack->r_ctl.roundends = tp->snd_max;
13574 					if (CC_ALGO(tp)->newround != NULL) {
13575 						CC_ALGO(tp)->newround(tp->ccv, rack->r_ctl.current_round);
13576 					}
13577 				}
13578 				/* Setup our act_rcv_time */
13579 				if ((ae->flags & TSTMP_LRO) || (ae->flags & TSTMP_HDWR)) {
13580 					ts.tv_sec = ae->timestamp / 1000000000;
13581 					ts.tv_nsec = ae->timestamp % 1000000000;
13582 					rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
13583 					rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
13584 				} else {
13585 					rack->r_ctl.act_rcv_time = *tv;
13586 				}
13587 				rack_process_to_cumack(tp, rack, ae->ack, cts, to);
13588 				if (rack->rc_dsack_round_seen) {
13589 					/* Is the dsack round over? */
13590 					if (SEQ_GEQ(ae->ack, rack->r_ctl.dsack_round_end)) {
13591 						/* Yes it is */
13592 						rack->rc_dsack_round_seen = 0;
13593 						rack_log_dsack_event(rack, 3, __LINE__, 0, 0);
13594 					}
13595 				}
13596 			}
13597 		}
13598 		/* And lets be sure to commit the rtt measurements for this ack */
13599 		tcp_rack_xmit_timer_commit(rack, tp);
13600 #ifdef TCP_ACCOUNTING
13601 		rdstc = get_cyclecount();
13602 		if (rdstc > ts_val) {
13603 			counter_u64_add(tcp_proc_time[ae->ack_val_set] , (rdstc - ts_val));
13604 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13605 				tp->tcp_proc_time[ae->ack_val_set] += (rdstc - ts_val);
13606 				if (ae->ack_val_set == ACK_CUMACK)
13607 					tp->tcp_proc_time[CYC_HANDLE_MAP] += (rdstc - ts_val);
13608 			}
13609 		}
13610 #endif
13611 	}
13612 #ifdef TCP_ACCOUNTING
13613 	ts_val = get_cyclecount();
13614 #endif
13615 	acked_amount = acked = (high_seq - tp->snd_una);
13616 	if (acked) {
13617 		/*
13618 		 * Clear the probe not answered flag
13619 		 * since cum-ack moved forward.
13620 		 */
13621 		rack->probe_not_answered = 0;
13622 		if (rack->sack_attack_disable == 0)
13623 			rack_do_decay(rack);
13624 		if (acked >= segsiz) {
13625 			/*
13626 			 * You only get credit for
13627 			 * MSS and greater (and you get extra
13628 			 * credit for larger cum-ack moves).
13629 			 */
13630 			int ac;
13631 
13632 			ac = acked / segsiz;
13633 			rack->r_ctl.ack_count += ac;
13634 			counter_u64_add(rack_ack_total, ac);
13635 		}
13636 		if (rack->r_ctl.ack_count > 0xfff00000) {
13637 			/*
13638 			 * reduce the number to keep us under
13639 			 * a uint32_t.
13640 			 */
13641 			rack->r_ctl.ack_count /= 2;
13642 			rack->r_ctl.sack_count /= 2;
13643 		}
13644 		if (tp->t_flags & TF_NEEDSYN) {
13645 			/*
13646 			 * T/TCP: Connection was half-synchronized, and our SYN has
13647 			 * been ACK'd (so connection is now fully synchronized).  Go
13648 			 * to non-starred state, increment snd_una for ACK of SYN,
13649 			 * and check if we can do window scaling.
13650 			 */
13651 			tp->t_flags &= ~TF_NEEDSYN;
13652 			tp->snd_una++;
13653 			acked_amount = acked = (high_seq - tp->snd_una);
13654 		}
13655 		if (acked > sbavail(&so->so_snd))
13656 			acked_amount = sbavail(&so->so_snd);
13657 #ifdef NETFLIX_EXP_DETECTION
13658 		/*
13659 		 * We only care on a cum-ack move if we are in a sack-disabled
13660 		 * state. We have already added in to the ack_count, and we never
13661 		 * would disable on a cum-ack move, so we only care to do the
13662 		 * detection if it may "undo" it, i.e. we were in disabled already.
13663 		 */
13664 		if (rack->sack_attack_disable)
13665 			rack_do_detection(tp, rack, acked_amount, segsiz);
13666 #endif
13667 		if (IN_FASTRECOVERY(tp->t_flags) &&
13668 		    (rack->rack_no_prr == 0))
13669 			rack_update_prr(tp, rack, acked_amount, high_seq);
13670 		if (IN_RECOVERY(tp->t_flags)) {
13671 			if (SEQ_LT(high_seq, tp->snd_recover) &&
13672 			    (SEQ_LT(high_seq, tp->snd_max))) {
13673 				tcp_rack_partialack(tp);
13674 			} else {
13675 				rack_post_recovery(tp, high_seq);
13676 				recovery = 1;
13677 			}
13678 		}
13679 		/* Handle the rack-log-ack part (sendmap) */
13680 		if ((sbused(&so->so_snd) == 0) &&
13681 		    (acked > acked_amount) &&
13682 		    (tp->t_state >= TCPS_FIN_WAIT_1) &&
13683 		    (tp->t_flags & TF_SENTFIN)) {
13684 			/*
13685 			 * We must be sure our fin
13686 			 * was sent and acked (we can be
13687 			 * in FIN_WAIT_1 without having
13688 			 * sent the fin).
13689 			 */
13690 			ourfinisacked = 1;
13691 			/*
13692 			 * Lets make sure snd_una is updated
13693 			 * since most likely acked_amount = 0 (it
13694 			 * should be).
13695 			 */
13696 			tp->snd_una = high_seq;
13697 		}
13698 		/* Did we make a RTO error? */
13699 		if ((tp->t_flags & TF_PREVVALID) &&
13700 		    ((tp->t_flags & TF_RCVD_TSTMP) == 0)) {
13701 			tp->t_flags &= ~TF_PREVVALID;
13702 			if (tp->t_rxtshift == 1 &&
13703 			    (int)(ticks - tp->t_badrxtwin) < 0)
13704 				rack_cong_signal(tp, CC_RTO_ERR, high_seq, __LINE__);
13705 		}
13706 		/* Handle the data in the socket buffer */
13707 		KMOD_TCPSTAT_ADD(tcps_rcvackpack, 1);
13708 		KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
13709 		if (acked_amount > 0) {
13710 			struct mbuf *mfree;
13711 
13712 			rack_ack_received(tp, rack, high_seq, nsegs, CC_ACK, recovery);
13713 			SOCKBUF_LOCK(&so->so_snd);
13714 			mfree = sbcut_locked(&so->so_snd, acked_amount);
13715 			tp->snd_una = high_seq;
13716 			/* Note we want to hold the sb lock through the sendmap adjust */
13717 			rack_adjust_sendmap(rack, &so->so_snd, tp->snd_una);
13718 			/* Wake up the socket if we have room to write more */
13719 			rack_log_wakeup(tp,rack, &so->so_snd, acked, 2);
13720 			sowwakeup_locked(so);
13721 			m_freem(mfree);
13722 		}
13723 		/* update progress */
13724 		tp->t_acktime = ticks;
13725 		rack_log_progress_event(rack, tp, tp->t_acktime,
13726 					PROGRESS_UPDATE, __LINE__);
13727 		/* Clear out shifts and such */
13728 		tp->t_rxtshift = 0;
13729 		RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
13730 				   rack_rto_min, rack_rto_max, rack->r_ctl.timer_slop);
13731 		rack->rc_tlp_in_progress = 0;
13732 		rack->r_ctl.rc_tlp_cnt_out = 0;
13733 		/* Send recover and snd_nxt must be dragged along */
13734 		if (SEQ_GT(tp->snd_una, tp->snd_recover))
13735 			tp->snd_recover = tp->snd_una;
13736 		if (SEQ_LT(tp->snd_nxt, tp->snd_una))
13737 			tp->snd_nxt = tp->snd_una;
13738 		/*
13739 		 * If the RXT timer is running we want to
13740 		 * stop it, so we can restart a TLP (or new RXT).
13741 		 */
13742 		if (rack->r_ctl.rc_hpts_flags & PACE_TMR_RXT)
13743 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13744 #ifdef NETFLIX_HTTP_LOGGING
13745 		tcp_http_check_for_comp(rack->rc_tp, high_seq);
13746 #endif
13747 		tp->snd_wl2 = high_seq;
13748 		tp->t_dupacks = 0;
13749 		if (under_pacing &&
13750 		    (rack->use_fixed_rate == 0) &&
13751 		    (rack->in_probe_rtt == 0) &&
13752 		    rack->rc_gp_dyn_mul &&
13753 		    rack->rc_always_pace) {
13754 			/* Check if we are dragging bottom */
13755 			rack_check_bottom_drag(tp, rack, so, acked);
13756 		}
13757 		if (tp->snd_una == tp->snd_max) {
13758 			tp->t_flags &= ~TF_PREVVALID;
13759 			rack->r_ctl.retran_during_recovery = 0;
13760 			rack->r_ctl.dsack_byte_cnt = 0;
13761 			rack->r_ctl.rc_went_idle_time = tcp_get_usecs(NULL);
13762 			if (rack->r_ctl.rc_went_idle_time == 0)
13763 				rack->r_ctl.rc_went_idle_time = 1;
13764 			rack_log_progress_event(rack, tp, 0, PROGRESS_CLEAR, __LINE__);
13765 			if (sbavail(&tp->t_inpcb->inp_socket->so_snd) == 0)
13766 				tp->t_acktime = 0;
13767 			/* Set so we might enter persists... */
13768 			rack->r_wanted_output = 1;
13769 			rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13770 			sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
13771 			if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
13772 			    (sbavail(&so->so_snd) == 0) &&
13773 			    (tp->t_flags2 & TF2_DROP_AF_DATA)) {
13774 				/*
13775 				 * The socket was gone and the
13776 				 * peer sent data (not now in the past), time to
13777 				 * reset him.
13778 				 */
13779 				rack_timer_cancel(tp, rack, rack->r_ctl.rc_rcvtime, __LINE__);
13780 				/* tcp_close will kill the inp pre-log the Reset */
13781 				tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
13782 #ifdef TCP_ACCOUNTING
13783 				rdstc = get_cyclecount();
13784 				if (rdstc > ts_val) {
13785 					counter_u64_add(tcp_proc_time[ACK_CUMACK] , (rdstc - ts_val));
13786 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13787 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13788 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13789 					}
13790 				}
13791 #endif
13792 				m_freem(m);
13793 				tp = tcp_close(tp);
13794 				if (tp == NULL) {
13795 #ifdef TCP_ACCOUNTING
13796 					sched_unpin();
13797 #endif
13798 					return (1);
13799 				}
13800 				/*
13801 				 * We would normally do drop-with-reset which would
13802 				 * send back a reset. We can't since we don't have
13803 				 * all the needed bits. Instead lets arrange for
13804 				 * a call to tcp_output(). That way since we
13805 				 * are in the closed state we will generate a reset.
13806 				 *
13807 				 * Note if tcp_accounting is on we don't unpin since
13808 				 * we do that after the goto label.
13809 				 */
13810 				goto send_out_a_rst;
13811 			}
13812 			if ((sbused(&so->so_snd) == 0) &&
13813 			    (tp->t_state >= TCPS_FIN_WAIT_1) &&
13814 			    (tp->t_flags & TF_SENTFIN)) {
13815 				/*
13816 				 * If we can't receive any more data, then closing user can
13817 				 * proceed. Starting the timer is contrary to the
13818 				 * specification, but if we don't get a FIN we'll hang
13819 				 * forever.
13820 				 *
13821 				 */
13822 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13823 					soisdisconnected(so);
13824 					tcp_timer_activate(tp, TT_2MSL,
13825 							   (tcp_fast_finwait2_recycle ?
13826 							    tcp_finwait2_timeout :
13827 							    TP_MAXIDLE(tp)));
13828 				}
13829 				if (ourfinisacked == 0) {
13830 					/*
13831 					 * We don't change to fin-wait-2 if we have our fin acked
13832 					 * which means we are probably in TCPS_CLOSING.
13833 					 */
13834 					tcp_state_change(tp, TCPS_FIN_WAIT_2);
13835 				}
13836 			}
13837 		}
13838 		/* Wake up the socket if we have room to write more */
13839 		if (sbavail(&so->so_snd)) {
13840 			rack->r_wanted_output = 1;
13841 			if (ctf_progress_timeout_check(tp, true)) {
13842 				rack_log_progress_event((struct tcp_rack *)tp->t_fb_ptr,
13843 							tp, tick, PROGRESS_DROP, __LINE__);
13844 				/*
13845 				 * We cheat here and don't send a RST, we should send one
13846 				 * when the pacer drops the connection.
13847 				 */
13848 #ifdef TCP_ACCOUNTING
13849 				rdstc = get_cyclecount();
13850 				if (rdstc > ts_val) {
13851 					counter_u64_add(tcp_proc_time[ACK_CUMACK] , (rdstc - ts_val));
13852 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13853 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13854 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13855 					}
13856 				}
13857 				sched_unpin();
13858 #endif
13859 				(void)tcp_drop(tp, ETIMEDOUT);
13860 				m_freem(m);
13861 				return (1);
13862 			}
13863 		}
13864 		if (ourfinisacked) {
13865 			switch(tp->t_state) {
13866 			case TCPS_CLOSING:
13867 #ifdef TCP_ACCOUNTING
13868 				rdstc = get_cyclecount();
13869 				if (rdstc > ts_val) {
13870 					counter_u64_add(tcp_proc_time[ACK_CUMACK] ,
13871 							(rdstc - ts_val));
13872 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13873 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13874 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13875 					}
13876 				}
13877 				sched_unpin();
13878 #endif
13879 				tcp_twstart(tp);
13880 				m_freem(m);
13881 				return (1);
13882 				break;
13883 			case TCPS_LAST_ACK:
13884 #ifdef TCP_ACCOUNTING
13885 				rdstc = get_cyclecount();
13886 				if (rdstc > ts_val) {
13887 					counter_u64_add(tcp_proc_time[ACK_CUMACK] ,
13888 							(rdstc - ts_val));
13889 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13890 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13891 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13892 					}
13893 				}
13894 				sched_unpin();
13895 #endif
13896 				tp = tcp_close(tp);
13897 				ctf_do_drop(m, tp);
13898 				return (1);
13899 				break;
13900 			case TCPS_FIN_WAIT_1:
13901 #ifdef TCP_ACCOUNTING
13902 				rdstc = get_cyclecount();
13903 				if (rdstc > ts_val) {
13904 					counter_u64_add(tcp_proc_time[ACK_CUMACK] ,
13905 							(rdstc - ts_val));
13906 					if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13907 						tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13908 						tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13909 					}
13910 				}
13911 #endif
13912 				if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
13913 					soisdisconnected(so);
13914 					tcp_timer_activate(tp, TT_2MSL,
13915 							   (tcp_fast_finwait2_recycle ?
13916 							    tcp_finwait2_timeout :
13917 							    TP_MAXIDLE(tp)));
13918 				}
13919 				tcp_state_change(tp, TCPS_FIN_WAIT_2);
13920 				break;
13921 			default:
13922 				break;
13923 			}
13924 		}
13925 		if (rack->r_fast_output) {
13926 			/*
13927 			 * We re doing fast output.. can we expand that?
13928 			 */
13929 			rack_gain_for_fastoutput(rack, tp, so, acked_amount);
13930 		}
13931 #ifdef TCP_ACCOUNTING
13932 		rdstc = get_cyclecount();
13933 		if (rdstc > ts_val) {
13934 			counter_u64_add(tcp_proc_time[ACK_CUMACK] , (rdstc - ts_val));
13935 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13936 				tp->tcp_proc_time[ACK_CUMACK] += (rdstc - ts_val);
13937 				tp->tcp_proc_time[CYC_HANDLE_ACK] += (rdstc - ts_val);
13938 			}
13939 		}
13940 
13941 	} else if (win_up_req) {
13942 		rdstc = get_cyclecount();
13943 		if (rdstc > ts_val) {
13944 			counter_u64_add(tcp_proc_time[ACK_RWND] , (rdstc - ts_val));
13945 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
13946 				tp->tcp_proc_time[ACK_RWND] += (rdstc - ts_val);
13947 			}
13948 		}
13949 #endif
13950 	}
13951 	/* Now is there a next packet, if so we are done */
13952 	m_freem(m);
13953 	did_out = 0;
13954 	if (nxt_pkt) {
13955 #ifdef TCP_ACCOUNTING
13956 		sched_unpin();
13957 #endif
13958 		rack_log_doseg_done(rack, cts, nxt_pkt, did_out, 5, nsegs);
13959 		return (0);
13960 	}
13961 	rack_handle_might_revert(tp, rack);
13962 	ctf_calc_rwin(so, tp);
13963 	if ((rack->r_wanted_output != 0) || (rack->r_fast_output != 0)) {
13964 	send_out_a_rst:
13965 		if (tcp_output(tp) < 0) {
13966 #ifdef TCP_ACCOUNTING
13967 			sched_unpin();
13968 #endif
13969 			return (1);
13970 		}
13971 		did_out = 1;
13972 	}
13973 	rack_free_trim(rack);
13974 #ifdef TCP_ACCOUNTING
13975 	sched_unpin();
13976 #endif
13977 	rack_timer_audit(tp, rack, &so->so_snd);
13978 	rack_log_doseg_done(rack, cts, nxt_pkt, did_out, 6, nsegs);
13979 	return (0);
13980 }
13981 
13982 
13983 static int
13984 rack_do_segment_nounlock(struct mbuf *m, struct tcphdr *th, struct socket *so,
13985     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos,
13986     int32_t nxt_pkt, struct timeval *tv)
13987 {
13988 #ifdef TCP_ACCOUNTING
13989 	uint64_t ts_val;
13990 #endif
13991 	int32_t thflags, retval, did_out = 0;
13992 	int32_t way_out = 0;
13993 	/*
13994 	 * cts - is the current time from tv (caller gets ts) in microseconds.
13995 	 * ms_cts - is the current time from tv in milliseconds.
13996 	 * us_cts - is the time that LRO or hardware actually got the packet in microseconds.
13997 	 */
13998 	uint32_t cts, us_cts, ms_cts;
13999 	uint32_t tiwin, high_seq;
14000 	struct timespec ts;
14001 	struct tcpopt to;
14002 	struct tcp_rack *rack;
14003 	struct rack_sendmap *rsm;
14004 	int32_t prev_state = 0;
14005 #ifdef TCP_ACCOUNTING
14006 	int ack_val_set = 0xf;
14007 #endif
14008 	int nsegs;
14009 	/*
14010 	 * tv passed from common code is from either M_TSTMP_LRO or
14011 	 * tcp_get_usecs() if no LRO m_pkthdr timestamp is present.
14012 	 */
14013 	rack = (struct tcp_rack *)tp->t_fb_ptr;
14014 	if (m->m_flags & M_ACKCMP) {
14015 		return (rack_do_compressed_ack_processing(tp, so, m, nxt_pkt, tv));
14016 	}
14017 	if (m->m_flags & M_ACKCMP) {
14018 		panic("Impossible reach m has ackcmp? m:%p tp:%p", m, tp);
14019 	}
14020 	cts = tcp_tv_to_usectick(tv);
14021 	ms_cts =  tcp_tv_to_mssectick(tv);
14022 	nsegs = m->m_pkthdr.lro_nsegs;
14023 	counter_u64_add(rack_proc_non_comp_ack, 1);
14024 	thflags = tcp_get_flags(th);
14025 #ifdef TCP_ACCOUNTING
14026 	sched_pin();
14027 	if (thflags & TH_ACK)
14028 		ts_val = get_cyclecount();
14029 #endif
14030 	if ((m->m_flags & M_TSTMP) ||
14031 	    (m->m_flags & M_TSTMP_LRO)) {
14032 		mbuf_tstmp2timespec(m, &ts);
14033 		rack->r_ctl.act_rcv_time.tv_sec = ts.tv_sec;
14034 		rack->r_ctl.act_rcv_time.tv_usec = ts.tv_nsec/1000;
14035 	} else
14036 		rack->r_ctl.act_rcv_time = *tv;
14037 	kern_prefetch(rack, &prev_state);
14038 	prev_state = 0;
14039 	/*
14040 	 * Unscale the window into a 32-bit value. For the SYN_SENT state
14041 	 * the scale is zero.
14042 	 */
14043 	tiwin = th->th_win << tp->snd_scale;
14044 #ifdef TCP_ACCOUNTING
14045 	if (thflags & TH_ACK) {
14046 		/*
14047 		 * We have a tradeoff here. We can either do what we are
14048 		 * doing i.e. pinning to this CPU and then doing the accounting
14049 		 * <or> we could do a critical enter, setup the rdtsc and cpu
14050 		 * as in below, and then validate we are on the same CPU on
14051 		 * exit. I have choosen to not do the critical enter since
14052 		 * that often will gain you a context switch, and instead lock
14053 		 * us (line above this if) to the same CPU with sched_pin(). This
14054 		 * means we may be context switched out for a higher priority
14055 		 * interupt but we won't be moved to another CPU.
14056 		 *
14057 		 * If this occurs (which it won't very often since we most likely
14058 		 * are running this code in interupt context and only a higher
14059 		 * priority will bump us ... clock?) we will falsely add in
14060 		 * to the time the interupt processing time plus the ack processing
14061 		 * time. This is ok since its a rare event.
14062 		 */
14063 		ack_val_set = tcp_do_ack_accounting(tp, th, &to, tiwin,
14064 						    ctf_fixed_maxseg(tp));
14065 	}
14066 #endif
14067 	/*
14068 	 * Parse options on any incoming segment.
14069 	 */
14070 	memset(&to, 0, sizeof(to));
14071 	tcp_dooptions(&to, (u_char *)(th + 1),
14072 	    (th->th_off << 2) - sizeof(struct tcphdr),
14073 	    (thflags & TH_SYN) ? TO_SYN : 0);
14074 	NET_EPOCH_ASSERT();
14075 	INP_WLOCK_ASSERT(tp->t_inpcb);
14076 	KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN",
14077 	    __func__));
14078 	KASSERT(tp->t_state != TCPS_TIME_WAIT, ("%s: TCPS_TIME_WAIT",
14079 	    __func__));
14080 	if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
14081 	    (tp->t_flags & TF_GPUTINPROG)) {
14082 		/*
14083 		 * We have a goodput in progress
14084 		 * and we have entered a late state.
14085 		 * Do we have enough data in the sb
14086 		 * to handle the GPUT request?
14087 		 */
14088 		uint32_t bytes;
14089 
14090 		bytes = tp->gput_ack - tp->gput_seq;
14091 		if (SEQ_GT(tp->gput_seq, tp->snd_una))
14092 			bytes += tp->gput_seq - tp->snd_una;
14093 		if (bytes > sbavail(&tp->t_inpcb->inp_socket->so_snd)) {
14094 			/*
14095 			 * There are not enough bytes in the socket
14096 			 * buffer that have been sent to cover this
14097 			 * measurement. Cancel it.
14098 			 */
14099 			rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
14100 						   rack->r_ctl.rc_gp_srtt /*flex1*/,
14101 						   tp->gput_seq,
14102 						   0, 0, 18, __LINE__, NULL, 0);
14103 			tp->t_flags &= ~TF_GPUTINPROG;
14104 		}
14105 	}
14106 	high_seq = th->th_ack;
14107 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
14108 		union tcp_log_stackspecific log;
14109 		struct timeval ltv;
14110 #ifdef NETFLIX_HTTP_LOGGING
14111 		struct http_sendfile_track *http_req;
14112 
14113 		if (SEQ_GT(th->th_ack, tp->snd_una)) {
14114 			http_req = tcp_http_find_req_for_seq(tp, (th->th_ack-1));
14115 		} else {
14116 			http_req = tcp_http_find_req_for_seq(tp, th->th_ack);
14117 		}
14118 #endif
14119 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
14120 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
14121 		if (rack->rack_no_prr == 0)
14122 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
14123 		else
14124 			log.u_bbr.flex1 = 0;
14125 		log.u_bbr.use_lt_bw = rack->r_ent_rec_ns;
14126 		log.u_bbr.use_lt_bw <<= 1;
14127 		log.u_bbr.use_lt_bw |= rack->r_might_revert;
14128 		log.u_bbr.flex2 = rack->r_ctl.rc_num_maps_alloced;
14129 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
14130 		log.u_bbr.pkts_out = rack->rc_tp->t_maxseg;
14131 		log.u_bbr.flex3 = m->m_flags;
14132 		log.u_bbr.flex4 = rack->r_ctl.rc_hpts_flags;
14133 		log.u_bbr.lost = thflags;
14134 		log.u_bbr.pacing_gain = 0x1;
14135 #ifdef TCP_ACCOUNTING
14136 		log.u_bbr.cwnd_gain = ack_val_set;
14137 #endif
14138 		log.u_bbr.flex7 = 2;
14139 		if (m->m_flags & M_TSTMP) {
14140 			/* Record the hardware timestamp if present */
14141 			mbuf_tstmp2timespec(m, &ts);
14142 			ltv.tv_sec = ts.tv_sec;
14143 			ltv.tv_usec = ts.tv_nsec / 1000;
14144 			log.u_bbr.lt_epoch = tcp_tv_to_usectick(&ltv);
14145 		} else if (m->m_flags & M_TSTMP_LRO) {
14146 			/* Record the LRO the arrival timestamp */
14147 			mbuf_tstmp2timespec(m, &ts);
14148 			ltv.tv_sec = ts.tv_sec;
14149 			ltv.tv_usec = ts.tv_nsec / 1000;
14150 			log.u_bbr.flex5 = tcp_tv_to_usectick(&ltv);
14151 		}
14152 		log.u_bbr.timeStamp = tcp_get_usecs(&ltv);
14153 		/* Log the rcv time */
14154 		log.u_bbr.delRate = m->m_pkthdr.rcv_tstmp;
14155 #ifdef NETFLIX_HTTP_LOGGING
14156 		log.u_bbr.applimited = tp->t_http_closed;
14157 		log.u_bbr.applimited <<= 8;
14158 		log.u_bbr.applimited |= tp->t_http_open;
14159 		log.u_bbr.applimited <<= 8;
14160 		log.u_bbr.applimited |= tp->t_http_req;
14161 		if (http_req) {
14162 			/* Copy out any client req info */
14163 			/* seconds */
14164 			log.u_bbr.pkt_epoch = (http_req->localtime / HPTS_USEC_IN_SEC);
14165 			/* useconds */
14166 			log.u_bbr.delivered = (http_req->localtime % HPTS_USEC_IN_SEC);
14167 			log.u_bbr.rttProp = http_req->timestamp;
14168 			log.u_bbr.cur_del_rate = http_req->start;
14169 			if (http_req->flags & TCP_HTTP_TRACK_FLG_OPEN) {
14170 				log.u_bbr.flex8 |= 1;
14171 			} else {
14172 				log.u_bbr.flex8 |= 2;
14173 				log.u_bbr.bw_inuse = http_req->end;
14174 			}
14175 			log.u_bbr.flex6 = http_req->start_seq;
14176 			if (http_req->flags & TCP_HTTP_TRACK_FLG_COMP) {
14177 				log.u_bbr.flex8 |= 4;
14178 				log.u_bbr.epoch = http_req->end_seq;
14179 			}
14180 		}
14181 #endif
14182 		TCP_LOG_EVENTP(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_IN, 0,
14183 		    tlen, &log, true, &ltv);
14184 	}
14185 	if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) {
14186 		way_out = 4;
14187 		retval = 0;
14188 		m_freem(m);
14189 		goto done_with_input;
14190 	}
14191 	/*
14192 	 * If a segment with the ACK-bit set arrives in the SYN-SENT state
14193 	 * check SEQ.ACK first as described on page 66 of RFC 793, section 3.9.
14194 	 */
14195 	if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) &&
14196 	    (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) {
14197 		tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
14198 		ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
14199 #ifdef TCP_ACCOUNTING
14200 		sched_unpin();
14201 #endif
14202 		return (1);
14203 	}
14204 	/*
14205 	 * If timestamps were negotiated during SYN/ACK and a
14206 	 * segment without a timestamp is received, silently drop
14207 	 * the segment, unless it is a RST segment or missing timestamps are
14208 	 * tolerated.
14209 	 * See section 3.2 of RFC 7323.
14210 	 */
14211 	if ((tp->t_flags & TF_RCVD_TSTMP) && !(to.to_flags & TOF_TS) &&
14212 	    ((thflags & TH_RST) == 0) && (V_tcp_tolerate_missing_ts == 0)) {
14213 		way_out = 5;
14214 		retval = 0;
14215 		m_freem(m);
14216 		goto done_with_input;
14217 	}
14218 
14219 	/*
14220 	 * Segment received on connection. Reset idle time and keep-alive
14221 	 * timer. XXX: This should be done after segment validation to
14222 	 * ignore broken/spoofed segs.
14223 	 */
14224 	if  (tp->t_idle_reduce &&
14225 	     (tp->snd_max == tp->snd_una) &&
14226 	     (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur)) {
14227 		counter_u64_add(rack_input_idle_reduces, 1);
14228 		rack_cc_after_idle(rack, tp);
14229 	}
14230 	tp->t_rcvtime = ticks;
14231 #ifdef STATS
14232 	stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_FRWIN, tiwin);
14233 #endif
14234 	if (tiwin > rack->r_ctl.rc_high_rwnd)
14235 		rack->r_ctl.rc_high_rwnd = tiwin;
14236 	/*
14237 	 * TCP ECN processing. XXXJTL: If we ever use ECN, we need to move
14238 	 * this to occur after we've validated the segment.
14239 	 */
14240 	if (tcp_ecn_input_segment(tp, thflags, iptos))
14241 		rack_cong_signal(tp, CC_ECN, th->th_ack, __LINE__);
14242 
14243 	/*
14244 	 * If echoed timestamp is later than the current time, fall back to
14245 	 * non RFC1323 RTT calculation.  Normalize timestamp if syncookies
14246 	 * were used when this connection was established.
14247 	 */
14248 	if ((to.to_flags & TOF_TS) && (to.to_tsecr != 0)) {
14249 		to.to_tsecr -= tp->ts_offset;
14250 		if (TSTMP_GT(to.to_tsecr, ms_cts))
14251 			to.to_tsecr = 0;
14252 	}
14253 
14254 	/*
14255 	 * If its the first time in we need to take care of options and
14256 	 * verify we can do SACK for rack!
14257 	 */
14258 	if (rack->r_state == 0) {
14259 		/* Should be init'd by rack_init() */
14260 		KASSERT(rack->rc_inp != NULL,
14261 		    ("%s: rack->rc_inp unexpectedly NULL", __func__));
14262 		if (rack->rc_inp == NULL) {
14263 			rack->rc_inp = tp->t_inpcb;
14264 		}
14265 
14266 		/*
14267 		 * Process options only when we get SYN/ACK back. The SYN
14268 		 * case for incoming connections is handled in tcp_syncache.
14269 		 * According to RFC1323 the window field in a SYN (i.e., a
14270 		 * <SYN> or <SYN,ACK>) segment itself is never scaled. XXX
14271 		 * this is traditional behavior, may need to be cleaned up.
14272 		 */
14273 		if (tp->t_state == TCPS_SYN_SENT && (thflags & TH_SYN)) {
14274 			/* Handle parallel SYN for ECN */
14275 			tcp_ecn_input_parallel_syn(tp, thflags, iptos);
14276 			if ((to.to_flags & TOF_SCALE) &&
14277 			    (tp->t_flags & TF_REQ_SCALE)) {
14278 				tp->t_flags |= TF_RCVD_SCALE;
14279 				tp->snd_scale = to.to_wscale;
14280 			} else
14281 				tp->t_flags &= ~TF_REQ_SCALE;
14282 			/*
14283 			 * Initial send window.  It will be updated with the
14284 			 * next incoming segment to the scaled value.
14285 			 */
14286 			tp->snd_wnd = th->th_win;
14287 			rack_validate_fo_sendwin_up(tp, rack);
14288 			if ((to.to_flags & TOF_TS) &&
14289 			    (tp->t_flags & TF_REQ_TSTMP)) {
14290 				tp->t_flags |= TF_RCVD_TSTMP;
14291 				tp->ts_recent = to.to_tsval;
14292 				tp->ts_recent_age = cts;
14293 			} else
14294 				tp->t_flags &= ~TF_REQ_TSTMP;
14295 			if (to.to_flags & TOF_MSS) {
14296 				tcp_mss(tp, to.to_mss);
14297 			}
14298 			if ((tp->t_flags & TF_SACK_PERMIT) &&
14299 			    (to.to_flags & TOF_SACKPERM) == 0)
14300 				tp->t_flags &= ~TF_SACK_PERMIT;
14301 			if (IS_FASTOPEN(tp->t_flags)) {
14302 				if (to.to_flags & TOF_FASTOPEN) {
14303 					uint16_t mss;
14304 
14305 					if (to.to_flags & TOF_MSS)
14306 						mss = to.to_mss;
14307 					else
14308 						if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0)
14309 							mss = TCP6_MSS;
14310 						else
14311 							mss = TCP_MSS;
14312 					tcp_fastopen_update_cache(tp, mss,
14313 					    to.to_tfo_len, to.to_tfo_cookie);
14314 				} else
14315 					tcp_fastopen_disable_path(tp);
14316 			}
14317 		}
14318 		/*
14319 		 * At this point we are at the initial call. Here we decide
14320 		 * if we are doing RACK or not. We do this by seeing if
14321 		 * TF_SACK_PERMIT is set and the sack-not-required is clear.
14322 		 * The code now does do dup-ack counting so if you don't
14323 		 * switch back you won't get rack & TLP, but you will still
14324 		 * get this stack.
14325 		 */
14326 
14327 		if ((rack_sack_not_required == 0) &&
14328 		    ((tp->t_flags & TF_SACK_PERMIT) == 0)) {
14329 			tcp_switch_back_to_default(tp);
14330 			(*tp->t_fb->tfb_tcp_do_segment) (m, th, so, tp, drop_hdrlen,
14331 			    tlen, iptos);
14332 #ifdef TCP_ACCOUNTING
14333 			sched_unpin();
14334 #endif
14335 			return (1);
14336 		}
14337 		tcp_set_hpts(tp->t_inpcb);
14338 		sack_filter_clear(&rack->r_ctl.rack_sf, th->th_ack);
14339 	}
14340 	if (thflags & TH_FIN)
14341 		tcp_log_end_status(tp, TCP_EI_STATUS_CLIENT_FIN);
14342 	us_cts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
14343 	if ((rack->rc_gp_dyn_mul) &&
14344 	    (rack->use_fixed_rate == 0) &&
14345 	    (rack->rc_always_pace)) {
14346 		/* Check in on probertt */
14347 		rack_check_probe_rtt(rack, us_cts);
14348 	}
14349 	rack_clear_rate_sample(rack);
14350 	if ((rack->forced_ack) &&
14351 	    ((tcp_get_flags(th) & TH_RST) == 0)) {
14352 		rack_handle_probe_response(rack, tiwin, us_cts);
14353 	}
14354 	/*
14355 	 * This is the one exception case where we set the rack state
14356 	 * always. All other times (timers etc) we must have a rack-state
14357 	 * set (so we assure we have done the checks above for SACK).
14358 	 */
14359 	rack->r_ctl.rc_rcvtime = cts;
14360 	if (rack->r_state != tp->t_state)
14361 		rack_set_state(tp, rack);
14362 	if (SEQ_GT(th->th_ack, tp->snd_una) &&
14363 	    (rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree)) != NULL)
14364 		kern_prefetch(rsm, &prev_state);
14365 	prev_state = rack->r_state;
14366 	retval = (*rack->r_substate) (m, th, so,
14367 	    tp, &to, drop_hdrlen,
14368 	    tlen, tiwin, thflags, nxt_pkt, iptos);
14369 #ifdef INVARIANTS
14370 	if ((retval == 0) &&
14371 	    (tp->t_inpcb == NULL)) {
14372 		panic("retval:%d tp:%p t_inpcb:NULL state:%d",
14373 		    retval, tp, prev_state);
14374 	}
14375 #endif
14376 	if (retval == 0) {
14377 		/*
14378 		 * If retval is 1 the tcb is unlocked and most likely the tp
14379 		 * is gone.
14380 		 */
14381 		INP_WLOCK_ASSERT(tp->t_inpcb);
14382 		if ((rack->rc_gp_dyn_mul) &&
14383 		    (rack->rc_always_pace) &&
14384 		    (rack->use_fixed_rate == 0) &&
14385 		    rack->in_probe_rtt &&
14386 		    (rack->r_ctl.rc_time_probertt_starts == 0)) {
14387 			/*
14388 			 * If we are going for target, lets recheck before
14389 			 * we output.
14390 			 */
14391 			rack_check_probe_rtt(rack, us_cts);
14392 		}
14393 		if (rack->set_pacing_done_a_iw == 0) {
14394 			/* How much has been acked? */
14395 			if ((tp->snd_una - tp->iss) > (ctf_fixed_maxseg(tp) * 10)) {
14396 				/* We have enough to set in the pacing segment size */
14397 				rack->set_pacing_done_a_iw = 1;
14398 				rack_set_pace_segments(tp, rack, __LINE__, NULL);
14399 			}
14400 		}
14401 		tcp_rack_xmit_timer_commit(rack, tp);
14402 #ifdef TCP_ACCOUNTING
14403 		/*
14404 		 * If we set the ack_val_se to what ack processing we are doing
14405 		 * we also want to track how many cycles we burned. Note
14406 		 * the bits after tcp_output we let be "free". This is because
14407 		 * we are also tracking the tcp_output times as well. Note the
14408 		 * use of 0xf here since we only have 11 counter (0 - 0xa) and
14409 		 * 0xf cannot be returned and is what we initialize it too to
14410 		 * indicate we are not doing the tabulations.
14411 		 */
14412 		if (ack_val_set != 0xf) {
14413 			uint64_t crtsc;
14414 
14415 			crtsc = get_cyclecount();
14416 			counter_u64_add(tcp_proc_time[ack_val_set] , (crtsc - ts_val));
14417 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
14418 				tp->tcp_proc_time[ack_val_set] += (crtsc - ts_val);
14419 			}
14420 		}
14421 #endif
14422 		if (nxt_pkt == 0) {
14423 			if ((rack->r_wanted_output != 0) || (rack->r_fast_output != 0)) {
14424 do_output_now:
14425 				if (tcp_output(tp) < 0)
14426 					return (1);
14427 				did_out = 1;
14428 			}
14429 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
14430 			rack_free_trim(rack);
14431 		}
14432 		/* Update any rounds needed */
14433 		if (rack_verbose_logging &&  (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF)) {
14434 			union tcp_log_stackspecific log;
14435 			struct timeval tv;
14436 
14437 			memset(&log.u_bbr, 0, sizeof(log.u_bbr));
14438 			log.u_bbr.timeStamp = tcp_get_usecs(&tv);
14439 			log.u_bbr.flex1 = high_seq;
14440 			log.u_bbr.flex2 = rack->r_ctl.roundends;
14441 			log.u_bbr.flex3 = rack->r_ctl.current_round;
14442 			log.u_bbr.rttProp = (uint64_t)CC_ALGO(tp)->newround;
14443 			log.u_bbr.flex8 = 9;
14444 			tcp_log_event_(tp, NULL, NULL, NULL, BBR_LOG_CWND, 0,
14445 				       0, &log, false, NULL, NULL, 0, &tv);
14446 		}
14447 		/*
14448 		 * The draft (v3) calls for us to use SEQ_GEQ, but that
14449 		 * causes issues when we are just going app limited. Lets
14450 		 * instead use SEQ_GT <or> where its equal but more data
14451 		 * is outstanding.
14452 		 */
14453 		if ((SEQ_GT(tp->snd_una, rack->r_ctl.roundends)) ||
14454 		    ((tp->snd_una == rack->r_ctl.roundends) && SEQ_GT(tp->snd_max, tp->snd_una))) {
14455 			rack->r_ctl.current_round++;
14456 			rack->r_ctl.roundends = tp->snd_max;
14457 			if (CC_ALGO(tp)->newround != NULL) {
14458 				CC_ALGO(tp)->newround(tp->ccv, rack->r_ctl.current_round);
14459 			}
14460 		}
14461 		if ((nxt_pkt == 0) &&
14462 		    ((rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) == 0) &&
14463 		    (SEQ_GT(tp->snd_max, tp->snd_una) ||
14464 		     (tp->t_flags & TF_DELACK) ||
14465 		     ((V_tcp_always_keepalive || rack->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
14466 		      (tp->t_state <= TCPS_CLOSING)))) {
14467 			/* We could not send (probably in the hpts but stopped the timer earlier)? */
14468 			if ((tp->snd_max == tp->snd_una) &&
14469 			    ((tp->t_flags & TF_DELACK) == 0) &&
14470 			    (tcp_in_hpts(rack->rc_inp)) &&
14471 			    (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
14472 				/* keep alive not needed if we are hptsi output yet */
14473 				;
14474 			} else {
14475 				int late = 0;
14476 				if (tcp_in_hpts(rack->rc_inp)) {
14477 					if (rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
14478 						us_cts = tcp_get_usecs(NULL);
14479 						if (TSTMP_GT(rack->r_ctl.rc_last_output_to, us_cts)) {
14480 							rack->r_early = 1;
14481 							rack->r_ctl.rc_agg_early += (rack->r_ctl.rc_last_output_to - us_cts);
14482 						} else
14483 							late = 1;
14484 						rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
14485 					}
14486 					tcp_hpts_remove(tp->t_inpcb);
14487 				}
14488 				if (late && (did_out == 0)) {
14489 					/*
14490 					 * We are late in the sending
14491 					 * and we did not call the output
14492 					 * (this probably should not happen).
14493 					 */
14494 					goto do_output_now;
14495 				}
14496 				rack_start_hpts_timer(rack, tp, tcp_get_usecs(NULL), 0, 0, 0);
14497 			}
14498 			way_out = 1;
14499 		} else if (nxt_pkt == 0) {
14500 			/* Do we have the correct timer running? */
14501 			rack_timer_audit(tp, rack, &so->so_snd);
14502 			way_out = 2;
14503 		}
14504 	done_with_input:
14505 		rack_log_doseg_done(rack, cts, nxt_pkt, did_out, way_out, max(1, nsegs));
14506 		if (did_out)
14507 			rack->r_wanted_output = 0;
14508 #ifdef INVARIANTS
14509 		if (tp->t_inpcb == NULL) {
14510 			panic("OP:%d retval:%d tp:%p t_inpcb:NULL state:%d",
14511 			      did_out,
14512 			      retval, tp, prev_state);
14513 		}
14514 #endif
14515 #ifdef TCP_ACCOUNTING
14516 	} else {
14517 		/*
14518 		 * Track the time (see above).
14519 		 */
14520 		if (ack_val_set != 0xf) {
14521 			uint64_t crtsc;
14522 
14523 			crtsc = get_cyclecount();
14524 			counter_u64_add(tcp_proc_time[ack_val_set] , (crtsc - ts_val));
14525 			/*
14526 			 * Note we *DO NOT* increment the per-tcb counters since
14527 			 * in the else the TP may be gone!!
14528 			 */
14529 		}
14530 #endif
14531 	}
14532 #ifdef TCP_ACCOUNTING
14533 	sched_unpin();
14534 #endif
14535 	return (retval);
14536 }
14537 
14538 void
14539 rack_do_segment(struct mbuf *m, struct tcphdr *th, struct socket *so,
14540     struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen, uint8_t iptos)
14541 {
14542 	struct timeval tv;
14543 
14544 	/* First lets see if we have old packets */
14545 	if (tp->t_in_pkt) {
14546 		if (ctf_do_queued_segments(so, tp, 1)) {
14547 			m_freem(m);
14548 			return;
14549 		}
14550 	}
14551 	if (m->m_flags & M_TSTMP_LRO) {
14552 		tv.tv_sec = m->m_pkthdr.rcv_tstmp /1000000000;
14553 		tv.tv_usec = (m->m_pkthdr.rcv_tstmp % 1000000000)/1000;
14554 	} else {
14555 		/* Should not be should we kassert instead? */
14556 		tcp_get_usecs(&tv);
14557 	}
14558 	if (rack_do_segment_nounlock(m, th, so, tp,
14559 				     drop_hdrlen, tlen, iptos, 0, &tv) == 0) {
14560 		INP_WUNLOCK(tp->t_inpcb);
14561 	}
14562 }
14563 
14564 struct rack_sendmap *
14565 tcp_rack_output(struct tcpcb *tp, struct tcp_rack *rack, uint32_t tsused)
14566 {
14567 	struct rack_sendmap *rsm = NULL;
14568 	int32_t idx;
14569 	uint32_t srtt = 0, thresh = 0, ts_low = 0;
14570 
14571 	/* Return the next guy to be re-transmitted */
14572 	if (RB_EMPTY(&rack->r_ctl.rc_mtree)) {
14573 		return (NULL);
14574 	}
14575 	if (tp->t_flags & TF_SENTFIN) {
14576 		/* retran the end FIN? */
14577 		return (NULL);
14578 	}
14579 	/* ok lets look at this one */
14580 	rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
14581 	if (rack->r_must_retran && rsm && (rsm->r_flags & RACK_MUST_RXT)) {
14582 		return (rsm);
14583 	}
14584 	if (rsm && ((rsm->r_flags & RACK_ACKED) == 0)) {
14585 		goto check_it;
14586 	}
14587 	rsm = rack_find_lowest_rsm(rack);
14588 	if (rsm == NULL) {
14589 		return (NULL);
14590 	}
14591 check_it:
14592 	if (((rack->rc_tp->t_flags & TF_SACK_PERMIT) == 0) &&
14593 	    (rsm->r_dupack >= DUP_ACK_THRESHOLD)) {
14594 		/*
14595 		 * No sack so we automatically do the 3 strikes and
14596 		 * retransmit (no rack timer would be started).
14597 		 */
14598 
14599 		return (rsm);
14600 	}
14601 	if (rsm->r_flags & RACK_ACKED) {
14602 		return (NULL);
14603 	}
14604 	if (((rsm->r_flags & RACK_SACK_PASSED) == 0) &&
14605 	    (rsm->r_dupack < DUP_ACK_THRESHOLD)) {
14606 		/* Its not yet ready */
14607 		return (NULL);
14608 	}
14609 	srtt = rack_grab_rtt(tp, rack);
14610 	idx = rsm->r_rtr_cnt - 1;
14611 	ts_low = (uint32_t)rsm->r_tim_lastsent[idx];
14612 	thresh = rack_calc_thresh_rack(rack, srtt, tsused);
14613 	if ((tsused == ts_low) ||
14614 	    (TSTMP_LT(tsused, ts_low))) {
14615 		/* No time since sending */
14616 		return (NULL);
14617 	}
14618 	if ((tsused - ts_low) < thresh) {
14619 		/* It has not been long enough yet */
14620 		return (NULL);
14621 	}
14622 	if ((rsm->r_dupack >= DUP_ACK_THRESHOLD) ||
14623 	    ((rsm->r_flags & RACK_SACK_PASSED) &&
14624 	     (rack->sack_attack_disable == 0))) {
14625 		/*
14626 		 * We have passed the dup-ack threshold <or>
14627 		 * a SACK has indicated this is missing.
14628 		 * Note that if you are a declared attacker
14629 		 * it is only the dup-ack threshold that
14630 		 * will cause retransmits.
14631 		 */
14632 		/* log retransmit reason */
14633 		rack_log_retran_reason(rack, rsm, (tsused - ts_low), thresh, 1);
14634 		rack->r_fast_output = 0;
14635 		return (rsm);
14636 	}
14637 	return (NULL);
14638 }
14639 
14640 static void
14641 rack_log_pacing_delay_calc(struct tcp_rack *rack, uint32_t len, uint32_t slot,
14642 			   uint64_t bw_est, uint64_t bw, uint64_t len_time, int method,
14643 			   int line, struct rack_sendmap *rsm, uint8_t quality)
14644 {
14645 	if (rack->rc_tp->t_logstate != TCP_LOG_STATE_OFF) {
14646 		union tcp_log_stackspecific log;
14647 		struct timeval tv;
14648 
14649 		memset(&log, 0, sizeof(log));
14650 		log.u_bbr.flex1 = slot;
14651 		log.u_bbr.flex2 = len;
14652 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_min_segs;
14653 		log.u_bbr.flex4 = rack->r_ctl.rc_pace_max_segs;
14654 		log.u_bbr.flex5 = rack->r_ctl.rack_per_of_gp_ss;
14655 		log.u_bbr.flex6 = rack->r_ctl.rack_per_of_gp_ca;
14656 		log.u_bbr.use_lt_bw = rack->rc_ack_can_sendout_data;
14657 		log.u_bbr.use_lt_bw <<= 1;
14658 		log.u_bbr.use_lt_bw |= rack->r_late;
14659 		log.u_bbr.use_lt_bw <<= 1;
14660 		log.u_bbr.use_lt_bw |= rack->r_early;
14661 		log.u_bbr.use_lt_bw <<= 1;
14662 		log.u_bbr.use_lt_bw |= rack->app_limited_needs_set;
14663 		log.u_bbr.use_lt_bw <<= 1;
14664 		log.u_bbr.use_lt_bw |= rack->rc_gp_filled;
14665 		log.u_bbr.use_lt_bw <<= 1;
14666 		log.u_bbr.use_lt_bw |= rack->measure_saw_probe_rtt;
14667 		log.u_bbr.use_lt_bw <<= 1;
14668 		log.u_bbr.use_lt_bw |= rack->in_probe_rtt;
14669 		log.u_bbr.use_lt_bw <<= 1;
14670 		log.u_bbr.use_lt_bw |= rack->gp_ready;
14671 		log.u_bbr.pkt_epoch = line;
14672 		log.u_bbr.epoch = rack->r_ctl.rc_agg_delayed;
14673 		log.u_bbr.lt_epoch = rack->r_ctl.rc_agg_early;
14674 		log.u_bbr.applimited = rack->r_ctl.rack_per_of_gp_rec;
14675 		log.u_bbr.bw_inuse = bw_est;
14676 		log.u_bbr.delRate = bw;
14677 		if (rack->r_ctl.gp_bw == 0)
14678 			log.u_bbr.cur_del_rate = 0;
14679 		else
14680 			log.u_bbr.cur_del_rate = rack_get_bw(rack);
14681 		log.u_bbr.rttProp = len_time;
14682 		log.u_bbr.pkts_out = rack->r_ctl.rc_rack_min_rtt;
14683 		log.u_bbr.lost = rack->r_ctl.rc_probertt_sndmax_atexit;
14684 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
14685 		if (rack->r_ctl.cwnd_to_use < rack->rc_tp->snd_ssthresh) {
14686 			/* We are in slow start */
14687 			log.u_bbr.flex7 = 1;
14688 		} else {
14689 			/* we are on congestion avoidance */
14690 			log.u_bbr.flex7 = 0;
14691 		}
14692 		log.u_bbr.flex8 = method;
14693 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
14694 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
14695 		log.u_bbr.cwnd_gain = rack->rc_gp_saw_rec;
14696 		log.u_bbr.cwnd_gain <<= 1;
14697 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ss;
14698 		log.u_bbr.cwnd_gain <<= 1;
14699 		log.u_bbr.cwnd_gain |= rack->rc_gp_saw_ca;
14700 		log.u_bbr.bbr_substate = quality;
14701 		TCP_LOG_EVENTP(rack->rc_tp, NULL,
14702 		    &rack->rc_inp->inp_socket->so_rcv,
14703 		    &rack->rc_inp->inp_socket->so_snd,
14704 		    BBR_LOG_HPTSI_CALC, 0,
14705 		    0, &log, false, &tv);
14706 	}
14707 }
14708 
14709 static uint32_t
14710 rack_get_pacing_len(struct tcp_rack *rack, uint64_t bw, uint32_t mss)
14711 {
14712 	uint32_t new_tso, user_max;
14713 
14714 	user_max = rack->rc_user_set_max_segs * mss;
14715 	if (rack->rc_force_max_seg) {
14716 		return (user_max);
14717 	}
14718 	if (rack->use_fixed_rate &&
14719 	    ((rack->r_ctl.crte == NULL) ||
14720 	     (bw != rack->r_ctl.crte->rate))) {
14721 		/* Use the user mss since we are not exactly matched */
14722 		return (user_max);
14723 	}
14724 	new_tso = tcp_get_pacing_burst_size(rack->rc_tp, bw, mss, rack_pace_one_seg, rack->r_ctl.crte, NULL);
14725 	if (new_tso > user_max)
14726 		new_tso = user_max;
14727 	return (new_tso);
14728 }
14729 
14730 static int32_t
14731 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)
14732 {
14733 	uint64_t lentim, fill_bw;
14734 
14735 	/* Lets first see if we are full, if so continue with normal rate */
14736 	rack->r_via_fill_cw = 0;
14737 	if (ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked) > rack->r_ctl.cwnd_to_use)
14738 		return (slot);
14739 	if ((ctf_outstanding(rack->rc_tp) + (segsiz-1)) > rack->rc_tp->snd_wnd)
14740 		return (slot);
14741 	if (rack->r_ctl.rc_last_us_rtt == 0)
14742 		return (slot);
14743 	if (rack->rc_pace_fill_if_rttin_range &&
14744 	    (rack->r_ctl.rc_last_us_rtt >=
14745 	     (get_filter_value_small(&rack->r_ctl.rc_gp_min_rtt) * rack->rtt_limit_mul))) {
14746 		/* The rtt is huge, N * smallest, lets not fill */
14747 		return (slot);
14748 	}
14749 	/*
14750 	 * first lets calculate the b/w based on the last us-rtt
14751 	 * and the sndwnd.
14752 	 */
14753 	fill_bw = rack->r_ctl.cwnd_to_use;
14754 	/* Take the rwnd if its smaller */
14755 	if (fill_bw > rack->rc_tp->snd_wnd)
14756 		fill_bw = rack->rc_tp->snd_wnd;
14757 	if (rack->r_fill_less_agg) {
14758 		/*
14759 		 * Now take away the inflight (this will reduce our
14760 		 * aggressiveness and yeah, if we get that much out in 1RTT
14761 		 * we will have had acks come back and still be behind).
14762 		 */
14763 		fill_bw -= ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
14764 	}
14765 	/* Now lets make it into a b/w */
14766 	fill_bw *= (uint64_t)HPTS_USEC_IN_SEC;
14767 	fill_bw /= (uint64_t)rack->r_ctl.rc_last_us_rtt;
14768 	/* We are below the min b/w */
14769 	if (non_paced)
14770 		*rate_wanted = fill_bw;
14771 	if ((fill_bw < RACK_MIN_BW) || (fill_bw < *rate_wanted))
14772 		return (slot);
14773 	if (rack->r_ctl.bw_rate_cap && (fill_bw > rack->r_ctl.bw_rate_cap))
14774 		fill_bw = rack->r_ctl.bw_rate_cap;
14775 	rack->r_via_fill_cw = 1;
14776 	if (rack->r_rack_hw_rate_caps &&
14777 	    (rack->r_ctl.crte != NULL)) {
14778 		uint64_t high_rate;
14779 
14780 		high_rate = tcp_hw_highest_rate(rack->r_ctl.crte);
14781 		if (fill_bw > high_rate) {
14782 			/* We are capping bw at the highest rate table entry */
14783 			if (*rate_wanted > high_rate) {
14784 				/* The original rate was also capped */
14785 				rack->r_via_fill_cw = 0;
14786 			}
14787 			rack_log_hdwr_pacing(rack,
14788 					     fill_bw, high_rate, __LINE__,
14789 					     0, 3);
14790 			fill_bw = high_rate;
14791 			if (capped)
14792 				*capped = 1;
14793 		}
14794 	} else if ((rack->r_ctl.crte == NULL) &&
14795 		   (rack->rack_hdrw_pacing == 0) &&
14796 		   (rack->rack_hdw_pace_ena) &&
14797 		   rack->r_rack_hw_rate_caps &&
14798 		   (rack->rack_attempt_hdwr_pace == 0) &&
14799 		   (rack->rc_inp->inp_route.ro_nh != NULL) &&
14800 		   (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
14801 		/*
14802 		 * Ok we may have a first attempt that is greater than our top rate
14803 		 * lets check.
14804 		 */
14805 		uint64_t high_rate;
14806 
14807 		high_rate = tcp_hw_highest_rate_ifp(rack->rc_inp->inp_route.ro_nh->nh_ifp, rack->rc_inp);
14808 		if (high_rate) {
14809 			if (fill_bw > high_rate) {
14810 				fill_bw = high_rate;
14811 				if (capped)
14812 					*capped = 1;
14813 			}
14814 		}
14815 	}
14816 	/*
14817 	 * Ok fill_bw holds our mythical b/w to fill the cwnd
14818 	 * in a rtt, what does that time wise equate too?
14819 	 */
14820 	lentim = (uint64_t)(len) * (uint64_t)HPTS_USEC_IN_SEC;
14821 	lentim /= fill_bw;
14822 	*rate_wanted = fill_bw;
14823 	if (non_paced || (lentim < slot)) {
14824 		rack_log_pacing_delay_calc(rack, len, slot, fill_bw,
14825 					   0, lentim, 12, __LINE__, NULL, 0);
14826 		return ((int32_t)lentim);
14827 	} else
14828 		return (slot);
14829 }
14830 
14831 static int32_t
14832 rack_get_pacing_delay(struct tcp_rack *rack, struct tcpcb *tp, uint32_t len, struct rack_sendmap *rsm, uint32_t segsiz)
14833 {
14834 	uint64_t srtt;
14835 	int32_t slot = 0;
14836 	int can_start_hw_pacing = 1;
14837 	int err;
14838 
14839 	if (rack->rc_always_pace == 0) {
14840 		/*
14841 		 * We use the most optimistic possible cwnd/srtt for
14842 		 * sending calculations. This will make our
14843 		 * calculation anticipate getting more through
14844 		 * quicker then possible. But thats ok we don't want
14845 		 * the peer to have a gap in data sending.
14846 		 */
14847 		uint64_t cwnd, tr_perms = 0;
14848 		int32_t reduce = 0;
14849 
14850 	old_method:
14851 		/*
14852 		 * We keep no precise pacing with the old method
14853 		 * instead we use the pacer to mitigate bursts.
14854 		 */
14855 		if (rack->r_ctl.rc_rack_min_rtt)
14856 			srtt = rack->r_ctl.rc_rack_min_rtt;
14857 		else
14858 			srtt = max(tp->t_srtt, 1);
14859 		if (rack->r_ctl.rc_rack_largest_cwnd)
14860 			cwnd = rack->r_ctl.rc_rack_largest_cwnd;
14861 		else
14862 			cwnd = rack->r_ctl.cwnd_to_use;
14863 		/* Inflate cwnd by 1000 so srtt of usecs is in ms */
14864 		tr_perms = (cwnd * 1000) / srtt;
14865 		if (tr_perms == 0) {
14866 			tr_perms = ctf_fixed_maxseg(tp);
14867 		}
14868 		/*
14869 		 * Calculate how long this will take to drain, if
14870 		 * the calculation comes out to zero, thats ok we
14871 		 * will use send_a_lot to possibly spin around for
14872 		 * more increasing tot_len_this_send to the point
14873 		 * that its going to require a pace, or we hit the
14874 		 * cwnd. Which in that case we are just waiting for
14875 		 * a ACK.
14876 		 */
14877 		slot = len / tr_perms;
14878 		/* Now do we reduce the time so we don't run dry? */
14879 		if (slot && rack_slot_reduction) {
14880 			reduce = (slot / rack_slot_reduction);
14881 			if (reduce < slot) {
14882 				slot -= reduce;
14883 			} else
14884 				slot = 0;
14885 		}
14886 		slot *= HPTS_USEC_IN_MSEC;
14887 		if (rack->rc_pace_to_cwnd) {
14888 			uint64_t rate_wanted = 0;
14889 
14890 			slot = pace_to_fill_cwnd(rack, slot, len, segsiz, NULL, &rate_wanted, 1);
14891 			rack->rc_ack_can_sendout_data = 1;
14892 			rack_log_pacing_delay_calc(rack, len, slot, rate_wanted, 0, 0, 14, __LINE__, NULL, 0);
14893 		} else
14894 			rack_log_pacing_delay_calc(rack, len, slot, tr_perms, reduce, 0, 7, __LINE__, NULL, 0);
14895 	} else {
14896 		uint64_t bw_est, res, lentim, rate_wanted;
14897 		uint32_t orig_val, segs, oh;
14898 		int capped = 0;
14899 		int prev_fill;
14900 
14901 		if ((rack->r_rr_config == 1) && rsm) {
14902 			return (rack->r_ctl.rc_min_to);
14903 		}
14904 		if (rack->use_fixed_rate) {
14905 			rate_wanted = bw_est = rack_get_fixed_pacing_bw(rack);
14906 		} else if ((rack->r_ctl.init_rate == 0) &&
14907 #ifdef NETFLIX_PEAKRATE
14908 			   (rack->rc_tp->t_maxpeakrate == 0) &&
14909 #endif
14910 			   (rack->r_ctl.gp_bw == 0)) {
14911 			/* no way to yet do an estimate */
14912 			bw_est = rate_wanted = 0;
14913 		} else {
14914 			bw_est = rack_get_bw(rack);
14915 			rate_wanted = rack_get_output_bw(rack, bw_est, rsm, &capped);
14916 		}
14917 		if ((bw_est == 0) || (rate_wanted == 0) ||
14918 		    ((rack->gp_ready == 0) && (rack->use_fixed_rate == 0))) {
14919 			/*
14920 			 * No way yet to make a b/w estimate or
14921 			 * our raise is set incorrectly.
14922 			 */
14923 			goto old_method;
14924 		}
14925 		/* We need to account for all the overheads */
14926 		segs = (len + segsiz - 1) / segsiz;
14927 		/*
14928 		 * We need the diff between 1514 bytes (e-mtu with e-hdr)
14929 		 * and how much data we put in each packet. Yes this
14930 		 * means we may be off if we are larger than 1500 bytes
14931 		 * or smaller. But this just makes us more conservative.
14932 		 */
14933 		if (rack_hw_rate_min &&
14934 		    (bw_est < rack_hw_rate_min))
14935 			can_start_hw_pacing = 0;
14936 		if (ETHERNET_SEGMENT_SIZE > segsiz)
14937 			oh = ETHERNET_SEGMENT_SIZE - segsiz;
14938 		else
14939 			oh = 0;
14940 		segs *= oh;
14941 		lentim = (uint64_t)(len + segs) * (uint64_t)HPTS_USEC_IN_SEC;
14942 		res = lentim / rate_wanted;
14943 		slot = (uint32_t)res;
14944 		orig_val = rack->r_ctl.rc_pace_max_segs;
14945 		if (rack->r_ctl.crte == NULL) {
14946 			/*
14947 			 * Only do this if we are not hardware pacing
14948 			 * since if we are doing hw-pacing below we will
14949 			 * set make a call after setting up or changing
14950 			 * the rate.
14951 			 */
14952 			rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
14953 		} else if (rack->rc_inp->inp_snd_tag == NULL) {
14954 			/*
14955 			 * We lost our rate somehow, this can happen
14956 			 * if the interface changed underneath us.
14957 			 */
14958 			tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
14959 			rack->r_ctl.crte = NULL;
14960 			/* Lets re-allow attempting to setup pacing */
14961 			rack->rack_hdrw_pacing = 0;
14962 			rack->rack_attempt_hdwr_pace = 0;
14963 			rack_log_hdwr_pacing(rack,
14964 					     rate_wanted, bw_est, __LINE__,
14965 					     0, 6);
14966 		}
14967 		/* Did we change the TSO size, if so log it */
14968 		if (rack->r_ctl.rc_pace_max_segs != orig_val)
14969 			rack_log_pacing_delay_calc(rack, len, slot, orig_val, 0, 0, 15, __LINE__, NULL, 0);
14970 		prev_fill = rack->r_via_fill_cw;
14971 		if ((rack->rc_pace_to_cwnd) &&
14972 		    (capped == 0) &&
14973 		    (rack->use_fixed_rate == 0) &&
14974 		    (rack->in_probe_rtt == 0) &&
14975 		    (IN_FASTRECOVERY(rack->rc_tp->t_flags) == 0)) {
14976 			/*
14977 			 * We want to pace at our rate *or* faster to
14978 			 * fill the cwnd to the max if its not full.
14979 			 */
14980 			slot = pace_to_fill_cwnd(rack, slot, (len+segs), segsiz, &capped, &rate_wanted, 0);
14981 		}
14982 		if ((rack->rc_inp->inp_route.ro_nh != NULL) &&
14983 		    (rack->rc_inp->inp_route.ro_nh->nh_ifp != NULL)) {
14984 			if ((rack->rack_hdw_pace_ena) &&
14985 			    (can_start_hw_pacing > 0) &&
14986 			    (rack->rack_hdrw_pacing == 0) &&
14987 			    (rack->rack_attempt_hdwr_pace == 0)) {
14988 				/*
14989 				 * Lets attempt to turn on hardware pacing
14990 				 * if we can.
14991 				 */
14992 				rack->rack_attempt_hdwr_pace = 1;
14993 				rack->r_ctl.crte = tcp_set_pacing_rate(rack->rc_tp,
14994 								       rack->rc_inp->inp_route.ro_nh->nh_ifp,
14995 								       rate_wanted,
14996 								       RS_PACING_GEQ,
14997 								       &err, &rack->r_ctl.crte_prev_rate);
14998 				if (rack->r_ctl.crte) {
14999 					rack->rack_hdrw_pacing = 1;
15000 					rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(tp, rate_wanted, segsiz,
15001 												 0, rack->r_ctl.crte,
15002 												 NULL);
15003 					rack_log_hdwr_pacing(rack,
15004 							     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
15005 							     err, 0);
15006 					rack->r_ctl.last_hw_bw_req = rate_wanted;
15007 				} else {
15008 					counter_u64_add(rack_hw_pace_init_fail, 1);
15009 				}
15010 			} else if (rack->rack_hdrw_pacing &&
15011 				   (rack->r_ctl.last_hw_bw_req != rate_wanted)) {
15012 				/* Do we need to adjust our rate? */
15013 				const struct tcp_hwrate_limit_table *nrte;
15014 
15015 				if (rack->r_up_only &&
15016 				    (rate_wanted < rack->r_ctl.crte->rate)) {
15017 					/**
15018 					 * We have four possible states here
15019 					 * having to do with the previous time
15020 					 * and this time.
15021 					 *   previous  |  this-time
15022 					 * A)     0      |     0   -- fill_cw not in the picture
15023 					 * B)     1      |     0   -- we were doing a fill-cw but now are not
15024 					 * C)     1      |     1   -- all rates from fill_cw
15025 					 * D)     0      |     1   -- we were doing non-fill and now we are filling
15026 					 *
15027 					 * For case A, C and D we don't allow a drop. But for
15028 					 * case B where we now our on our steady rate we do
15029 					 * allow a drop.
15030 					 *
15031 					 */
15032 					if (!((prev_fill == 1) && (rack->r_via_fill_cw == 0)))
15033 						goto done_w_hdwr;
15034 				}
15035 				if ((rate_wanted > rack->r_ctl.crte->rate) ||
15036 				    (rate_wanted <= rack->r_ctl.crte_prev_rate)) {
15037 					if (rack_hw_rate_to_low &&
15038 					    (bw_est < rack_hw_rate_to_low)) {
15039 						/*
15040 						 * The pacing rate is too low for hardware, but
15041 						 * do allow hardware pacing to be restarted.
15042 						 */
15043 						rack_log_hdwr_pacing(rack,
15044 							     bw_est, rack->r_ctl.crte->rate, __LINE__,
15045 							     0, 5);
15046 						tcp_rel_pacing_rate(rack->r_ctl.crte, rack->rc_tp);
15047 						rack->r_ctl.crte = NULL;
15048 						rack->rack_attempt_hdwr_pace = 0;
15049 						rack->rack_hdrw_pacing = 0;
15050 						rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
15051 						goto done_w_hdwr;
15052 					}
15053 					nrte = tcp_chg_pacing_rate(rack->r_ctl.crte,
15054 								   rack->rc_tp,
15055 								   rack->rc_inp->inp_route.ro_nh->nh_ifp,
15056 								   rate_wanted,
15057 								   RS_PACING_GEQ,
15058 								   &err, &rack->r_ctl.crte_prev_rate);
15059 					if (nrte == NULL) {
15060 						/* Lost the rate */
15061 						rack->rack_hdrw_pacing = 0;
15062 						rack->r_ctl.crte = NULL;
15063 						rack_log_hdwr_pacing(rack,
15064 								     rate_wanted, 0, __LINE__,
15065 								     err, 1);
15066 						rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
15067 						counter_u64_add(rack_hw_pace_lost, 1);
15068 					} else if (nrte != rack->r_ctl.crte) {
15069 						rack->r_ctl.crte = nrte;
15070 						rack->r_ctl.rc_pace_max_segs = tcp_get_pacing_burst_size(tp, rate_wanted,
15071 													 segsiz, 0,
15072 													 rack->r_ctl.crte,
15073 													 NULL);
15074 						rack_log_hdwr_pacing(rack,
15075 								     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
15076 								     err, 2);
15077 						rack->r_ctl.last_hw_bw_req = rate_wanted;
15078 					}
15079 				} else {
15080 					/* We just need to adjust the segment size */
15081 					rack_set_pace_segments(rack->rc_tp, rack, __LINE__, &rate_wanted);
15082 					rack_log_hdwr_pacing(rack,
15083 							     rate_wanted, rack->r_ctl.crte->rate, __LINE__,
15084 							     0, 4);
15085 					rack->r_ctl.last_hw_bw_req = rate_wanted;
15086 				}
15087 			}
15088 		}
15089 		if ((rack->r_ctl.crte != NULL) &&
15090 		    (rack->r_ctl.crte->rate == rate_wanted)) {
15091 			/*
15092 			 * We need to add a extra if the rates
15093 			 * are exactly matched. The idea is
15094 			 * we want the software to make sure the
15095 			 * queue is empty before adding more, this
15096 			 * gives us N MSS extra pace times where
15097 			 * N is our sysctl
15098 			 */
15099 			slot += (rack->r_ctl.crte->time_between * rack_hw_pace_extra_slots);
15100 		}
15101 done_w_hdwr:
15102 		if (rack_limit_time_with_srtt &&
15103 		    (rack->use_fixed_rate == 0) &&
15104 #ifdef NETFLIX_PEAKRATE
15105 		    (rack->rc_tp->t_maxpeakrate == 0) &&
15106 #endif
15107 		    (rack->rack_hdrw_pacing == 0)) {
15108 			/*
15109 			 * Sanity check, we do not allow the pacing delay
15110 			 * to be longer than the SRTT of the path. If it is
15111 			 * a slow path, then adding a packet should increase
15112 			 * the RTT and compensate for this i.e. the srtt will
15113 			 * be greater so the allowed pacing time will be greater.
15114 			 *
15115 			 * Note this restriction is not for where a peak rate
15116 			 * is set, we are doing fixed pacing or hardware pacing.
15117 			 */
15118 			if (rack->rc_tp->t_srtt)
15119 				srtt = rack->rc_tp->t_srtt;
15120 			else
15121 				srtt = RACK_INITIAL_RTO * HPTS_USEC_IN_MSEC;	/* its in ms convert */
15122 			if (srtt < (uint64_t)slot) {
15123 				rack_log_pacing_delay_calc(rack, srtt, slot, rate_wanted, bw_est, lentim, 99, __LINE__, NULL, 0);
15124 				slot = srtt;
15125 			}
15126 		}
15127 		rack_log_pacing_delay_calc(rack, len, slot, rate_wanted, bw_est, lentim, 2, __LINE__, rsm, 0);
15128 	}
15129 	if (rack->r_ctl.crte && (rack->r_ctl.crte->rs_num_enobufs > 0)) {
15130 		/*
15131 		 * If this rate is seeing enobufs when it
15132 		 * goes to send then either the nic is out
15133 		 * of gas or we are mis-estimating the time
15134 		 * somehow and not letting the queue empty
15135 		 * completely. Lets add to the pacing time.
15136 		 */
15137 		int hw_boost_delay;
15138 
15139 		hw_boost_delay = rack->r_ctl.crte->time_between * rack_enobuf_hw_boost_mult;
15140 		if (hw_boost_delay > rack_enobuf_hw_max)
15141 			hw_boost_delay = rack_enobuf_hw_max;
15142 		else if (hw_boost_delay < rack_enobuf_hw_min)
15143 			hw_boost_delay = rack_enobuf_hw_min;
15144 		slot += hw_boost_delay;
15145 	}
15146 	return (slot);
15147 }
15148 
15149 static void
15150 rack_start_gp_measurement(struct tcpcb *tp, struct tcp_rack *rack,
15151     tcp_seq startseq, uint32_t sb_offset)
15152 {
15153 	struct rack_sendmap *my_rsm = NULL;
15154 	struct rack_sendmap fe;
15155 
15156 	if (tp->t_state < TCPS_ESTABLISHED) {
15157 		/*
15158 		 * We don't start any measurements if we are
15159 		 * not at least established.
15160 		 */
15161 		return;
15162 	}
15163 	if (tp->t_state >= TCPS_FIN_WAIT_1) {
15164 		/*
15165 		 * We will get no more data into the SB
15166 		 * this means we need to have the data available
15167 		 * before we start a measurement.
15168 		 */
15169 
15170 		if (sbavail(&tp->t_inpcb->inp_socket->so_snd) <
15171 		    max(rc_init_window(rack),
15172 			(MIN_GP_WIN * ctf_fixed_maxseg(tp)))) {
15173 			/* Nope not enough data */
15174 			return;
15175 		}
15176 	}
15177 	tp->t_flags |= TF_GPUTINPROG;
15178 	rack->r_ctl.rc_gp_lowrtt = 0xffffffff;
15179 	rack->r_ctl.rc_gp_high_rwnd = rack->rc_tp->snd_wnd;
15180 	tp->gput_seq = startseq;
15181 	rack->app_limited_needs_set = 0;
15182 	if (rack->in_probe_rtt)
15183 		rack->measure_saw_probe_rtt = 1;
15184 	else if ((rack->measure_saw_probe_rtt) &&
15185 		 (SEQ_GEQ(tp->gput_seq, rack->r_ctl.rc_probertt_sndmax_atexit)))
15186 		rack->measure_saw_probe_rtt = 0;
15187 	if (rack->rc_gp_filled)
15188 		tp->gput_ts = tcp_tv_to_usectick(&rack->r_ctl.act_rcv_time);
15189 	else {
15190 		/* Special case initial measurement */
15191 		struct timeval tv;
15192 
15193 		tp->gput_ts = tcp_get_usecs(&tv);
15194 		rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
15195 	}
15196 	/*
15197 	 * We take a guess out into the future,
15198 	 * if we have no measurement and no
15199 	 * initial rate, we measure the first
15200 	 * initial-windows worth of data to
15201 	 * speed up getting some GP measurement and
15202 	 * thus start pacing.
15203 	 */
15204 	if ((rack->rc_gp_filled == 0) && (rack->r_ctl.init_rate == 0)) {
15205 		rack->app_limited_needs_set = 1;
15206 		tp->gput_ack = startseq + max(rc_init_window(rack),
15207 					      (MIN_GP_WIN * ctf_fixed_maxseg(tp)));
15208 		rack_log_pacing_delay_calc(rack,
15209 					   tp->gput_seq,
15210 					   tp->gput_ack,
15211 					   0,
15212 					   tp->gput_ts,
15213 					   rack->r_ctl.rc_app_limited_cnt,
15214 					   9,
15215 					   __LINE__, NULL, 0);
15216 		return;
15217 	}
15218 	if (sb_offset) {
15219 		/*
15220 		 * We are out somewhere in the sb
15221 		 * can we use the already outstanding data?
15222 		 */
15223 		if (rack->r_ctl.rc_app_limited_cnt == 0) {
15224 			/*
15225 			 * Yes first one is good and in this case
15226 			 * the tp->gput_ts is correctly set based on
15227 			 * the last ack that arrived (no need to
15228 			 * set things up when an ack comes in).
15229 			 */
15230 			my_rsm = RB_MIN(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
15231 			if ((my_rsm == NULL) ||
15232 			    (my_rsm->r_rtr_cnt != 1)) {
15233 				/* retransmission? */
15234 				goto use_latest;
15235 			}
15236 		} else {
15237 			if (rack->r_ctl.rc_first_appl == NULL) {
15238 				/*
15239 				 * If rc_first_appl is NULL
15240 				 * then the cnt should be 0.
15241 				 * This is probably an error, maybe
15242 				 * a KASSERT would be approprate.
15243 				 */
15244 				goto use_latest;
15245 			}
15246 			/*
15247 			 * If we have a marker pointer to the last one that is
15248 			 * app limited we can use that, but we need to set
15249 			 * things up so that when it gets ack'ed we record
15250 			 * the ack time (if its not already acked).
15251 			 */
15252 			rack->app_limited_needs_set = 1;
15253 			/*
15254 			 * We want to get to the rsm that is either
15255 			 * next with space i.e. over 1 MSS or the one
15256 			 * after that (after the app-limited).
15257 			 */
15258 			my_rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree,
15259 					 rack->r_ctl.rc_first_appl);
15260 			if (my_rsm) {
15261 				if ((my_rsm->r_end - my_rsm->r_start) <= ctf_fixed_maxseg(tp))
15262 					/* Have to use the next one */
15263 					my_rsm = RB_NEXT(rack_rb_tree_head, &rack->r_ctl.rc_mtree,
15264 							 my_rsm);
15265 				else {
15266 					/* Use after the first MSS of it is acked */
15267 					tp->gput_seq = my_rsm->r_start + ctf_fixed_maxseg(tp);
15268 					goto start_set;
15269 				}
15270 			}
15271 			if ((my_rsm == NULL) ||
15272 			    (my_rsm->r_rtr_cnt != 1)) {
15273 				/*
15274 				 * Either its a retransmit or
15275 				 * the last is the app-limited one.
15276 				 */
15277 				goto use_latest;
15278 			}
15279 		}
15280 		tp->gput_seq = my_rsm->r_start;
15281 start_set:
15282 		if (my_rsm->r_flags & RACK_ACKED) {
15283 			/*
15284 			 * This one has been acked use the arrival ack time
15285 			 */
15286 			tp->gput_ts = (uint32_t)my_rsm->r_ack_arrival;
15287 			rack->app_limited_needs_set = 0;
15288 		}
15289 		rack->r_ctl.rc_gp_output_ts = my_rsm->r_tim_lastsent[(my_rsm->r_rtr_cnt-1)];
15290 		tp->gput_ack = tp->gput_seq + rack_get_measure_window(tp, rack);
15291 		rack_log_pacing_delay_calc(rack,
15292 					   tp->gput_seq,
15293 					   tp->gput_ack,
15294 					   (uint64_t)my_rsm,
15295 					   tp->gput_ts,
15296 					   rack->r_ctl.rc_app_limited_cnt,
15297 					   9,
15298 					   __LINE__, NULL, 0);
15299 		return;
15300 	}
15301 
15302 use_latest:
15303 	/*
15304 	 * We don't know how long we may have been
15305 	 * idle or if this is the first-send. Lets
15306 	 * setup the flag so we will trim off
15307 	 * the first ack'd data so we get a true
15308 	 * measurement.
15309 	 */
15310 	rack->app_limited_needs_set = 1;
15311 	tp->gput_ack = startseq + rack_get_measure_window(tp, rack);
15312 	/* Find this guy so we can pull the send time */
15313 	fe.r_start = startseq;
15314 	my_rsm = RB_FIND(rack_rb_tree_head, &rack->r_ctl.rc_mtree, &fe);
15315 	if (my_rsm) {
15316 		rack->r_ctl.rc_gp_output_ts = my_rsm->r_tim_lastsent[(my_rsm->r_rtr_cnt-1)];
15317 		if (my_rsm->r_flags & RACK_ACKED) {
15318 			/*
15319 			 * Unlikely since its probably what was
15320 			 * just transmitted (but I am paranoid).
15321 			 */
15322 			tp->gput_ts = (uint32_t)my_rsm->r_ack_arrival;
15323 			rack->app_limited_needs_set = 0;
15324 		}
15325 		if (SEQ_LT(my_rsm->r_start, tp->gput_seq)) {
15326 			/* This also is unlikely */
15327 			tp->gput_seq = my_rsm->r_start;
15328 		}
15329 	} else {
15330 		/*
15331 		 * TSNH unless we have some send-map limit,
15332 		 * and even at that it should not be hitting
15333 		 * that limit (we should have stopped sending).
15334 		 */
15335 		struct timeval tv;
15336 
15337 		microuptime(&tv);
15338 		rack->r_ctl.rc_gp_output_ts = rack_to_usec_ts(&tv);
15339 	}
15340 	rack_log_pacing_delay_calc(rack,
15341 				   tp->gput_seq,
15342 				   tp->gput_ack,
15343 				   (uint64_t)my_rsm,
15344 				   tp->gput_ts,
15345 				   rack->r_ctl.rc_app_limited_cnt,
15346 				   9, __LINE__, NULL, 0);
15347 }
15348 
15349 static inline uint32_t
15350 rack_what_can_we_send(struct tcpcb *tp, struct tcp_rack *rack,  uint32_t cwnd_to_use,
15351     uint32_t avail, int32_t sb_offset)
15352 {
15353 	uint32_t len;
15354 	uint32_t sendwin;
15355 
15356 	if (tp->snd_wnd > cwnd_to_use)
15357 		sendwin = cwnd_to_use;
15358 	else
15359 		sendwin = tp->snd_wnd;
15360 	if (ctf_outstanding(tp) >= tp->snd_wnd) {
15361 		/* We never want to go over our peers rcv-window */
15362 		len = 0;
15363 	} else {
15364 		uint32_t flight;
15365 
15366 		flight = ctf_flight_size(tp, rack->r_ctl.rc_sacked);
15367 		if (flight >= sendwin) {
15368 			/*
15369 			 * We have in flight what we are allowed by cwnd (if
15370 			 * it was rwnd blocking it would have hit above out
15371 			 * >= tp->snd_wnd).
15372 			 */
15373 			return (0);
15374 		}
15375 		len = sendwin - flight;
15376 		if ((len + ctf_outstanding(tp)) > tp->snd_wnd) {
15377 			/* We would send too much (beyond the rwnd) */
15378 			len = tp->snd_wnd - ctf_outstanding(tp);
15379 		}
15380 		if ((len + sb_offset) > avail) {
15381 			/*
15382 			 * We don't have that much in the SB, how much is
15383 			 * there?
15384 			 */
15385 			len = avail - sb_offset;
15386 		}
15387 	}
15388 	return (len);
15389 }
15390 
15391 static void
15392 rack_log_fsb(struct tcp_rack *rack, struct tcpcb *tp, struct socket *so, uint32_t flags,
15393 	     unsigned ipoptlen, int32_t orig_len, int32_t len, int error,
15394 	     int rsm_is_null, int optlen, int line, uint16_t mode)
15395 {
15396 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
15397 		union tcp_log_stackspecific log;
15398 		struct timeval tv;
15399 
15400 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
15401 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
15402 		log.u_bbr.flex1 = error;
15403 		log.u_bbr.flex2 = flags;
15404 		log.u_bbr.flex3 = rsm_is_null;
15405 		log.u_bbr.flex4 = ipoptlen;
15406 		log.u_bbr.flex5 = tp->rcv_numsacks;
15407 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
15408 		log.u_bbr.flex7 = optlen;
15409 		log.u_bbr.flex8 = rack->r_fsb_inited;
15410 		log.u_bbr.applimited = rack->r_fast_output;
15411 		log.u_bbr.bw_inuse = rack_get_bw(rack);
15412 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
15413 		log.u_bbr.cwnd_gain = mode;
15414 		log.u_bbr.pkts_out = orig_len;
15415 		log.u_bbr.lt_epoch = len;
15416 		log.u_bbr.delivered = line;
15417 		log.u_bbr.timeStamp = tcp_get_usecs(&tv);
15418 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
15419 		tcp_log_event_(tp, NULL, &so->so_rcv, &so->so_snd, TCP_LOG_FSB, 0,
15420 			       len, &log, false, NULL, NULL, 0, &tv);
15421 	}
15422 }
15423 
15424 
15425 static struct mbuf *
15426 rack_fo_base_copym(struct mbuf *the_m, uint32_t the_off, int32_t *plen,
15427 		   struct rack_fast_send_blk *fsb,
15428 		   int32_t seglimit, int32_t segsize, int hw_tls)
15429 {
15430 #ifdef KERN_TLS
15431 	struct ktls_session *tls, *ntls;
15432 #ifdef INVARIANTS
15433 	struct mbuf *start;
15434 #endif
15435 #endif
15436 	struct mbuf *m, *n, **np, *smb;
15437 	struct mbuf *top;
15438 	int32_t off, soff;
15439 	int32_t len = *plen;
15440 	int32_t fragsize;
15441 	int32_t len_cp = 0;
15442 	uint32_t mlen, frags;
15443 
15444 	soff = off = the_off;
15445 	smb = m = the_m;
15446 	np = &top;
15447 	top = NULL;
15448 #ifdef KERN_TLS
15449 	if (hw_tls && (m->m_flags & M_EXTPG))
15450 		tls = m->m_epg_tls;
15451 	else
15452 		tls = NULL;
15453 #ifdef INVARIANTS
15454 	start = m;
15455 #endif
15456 #endif
15457 	while (len > 0) {
15458 		if (m == NULL) {
15459 			*plen = len_cp;
15460 			break;
15461 		}
15462 #ifdef KERN_TLS
15463 		if (hw_tls) {
15464 			if (m->m_flags & M_EXTPG)
15465 				ntls = m->m_epg_tls;
15466 			else
15467 				ntls = NULL;
15468 
15469 			/*
15470 			 * Avoid mixing TLS records with handshake
15471 			 * data or TLS records from different
15472 			 * sessions.
15473 			 */
15474 			if (tls != ntls) {
15475 				MPASS(m != start);
15476 				*plen = len_cp;
15477 				break;
15478 			}
15479 		}
15480 #endif
15481 		mlen = min(len, m->m_len - off);
15482 		if (seglimit) {
15483 			/*
15484 			 * For M_EXTPG mbufs, add 3 segments
15485 			 * + 1 in case we are crossing page boundaries
15486 			 * + 2 in case the TLS hdr/trailer are used
15487 			 * It is cheaper to just add the segments
15488 			 * than it is to take the cache miss to look
15489 			 * at the mbuf ext_pgs state in detail.
15490 			 */
15491 			if (m->m_flags & M_EXTPG) {
15492 				fragsize = min(segsize, PAGE_SIZE);
15493 				frags = 3;
15494 			} else {
15495 				fragsize = segsize;
15496 				frags = 0;
15497 			}
15498 
15499 			/* Break if we really can't fit anymore. */
15500 			if ((frags + 1) >= seglimit) {
15501 				*plen =	len_cp;
15502 				break;
15503 			}
15504 
15505 			/*
15506 			 * Reduce size if you can't copy the whole
15507 			 * mbuf. If we can't copy the whole mbuf, also
15508 			 * adjust len so the loop will end after this
15509 			 * mbuf.
15510 			 */
15511 			if ((frags + howmany(mlen, fragsize)) >= seglimit) {
15512 				mlen = (seglimit - frags - 1) * fragsize;
15513 				len = mlen;
15514 				*plen = len_cp + len;
15515 			}
15516 			frags += howmany(mlen, fragsize);
15517 			if (frags == 0)
15518 				frags++;
15519 			seglimit -= frags;
15520 			KASSERT(seglimit > 0,
15521 			    ("%s: seglimit went too low", __func__));
15522 		}
15523 		n = m_get(M_NOWAIT, m->m_type);
15524 		*np = n;
15525 		if (n == NULL)
15526 			goto nospace;
15527 		n->m_len = mlen;
15528 		soff += mlen;
15529 		len_cp += n->m_len;
15530 		if (m->m_flags & (M_EXT|M_EXTPG)) {
15531 			n->m_data = m->m_data + off;
15532 			mb_dupcl(n, m);
15533 		} else {
15534 			bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t),
15535 			    (u_int)n->m_len);
15536 		}
15537 		len -= n->m_len;
15538 		off = 0;
15539 		m = m->m_next;
15540 		np = &n->m_next;
15541 		if (len || (soff == smb->m_len)) {
15542 			/*
15543 			 * We have more so we move forward  or
15544 			 * we have consumed the entire mbuf and
15545 			 * len has fell to 0.
15546 			 */
15547 			soff = 0;
15548 			smb = m;
15549 		}
15550 
15551 	}
15552 	if (fsb != NULL) {
15553 		fsb->m = smb;
15554 		fsb->off = soff;
15555 		if (smb) {
15556 			/*
15557 			 * Save off the size of the mbuf. We do
15558 			 * this so that we can recognize when it
15559 			 * has been trimmed by sbcut() as acks
15560 			 * come in.
15561 			 */
15562 			fsb->o_m_len = smb->m_len;
15563 		} else {
15564 			/*
15565 			 * This is the case where the next mbuf went to NULL. This
15566 			 * means with this copy we have sent everything in the sb.
15567 			 * In theory we could clear the fast_output flag, but lets
15568 			 * not since its possible that we could get more added
15569 			 * and acks that call the extend function which would let
15570 			 * us send more.
15571 			 */
15572 			fsb->o_m_len = 0;
15573 		}
15574 	}
15575 	return (top);
15576 nospace:
15577 	if (top)
15578 		m_freem(top);
15579 	return (NULL);
15580 
15581 }
15582 
15583 /*
15584  * This is a copy of m_copym(), taking the TSO segment size/limit
15585  * constraints into account, and advancing the sndptr as it goes.
15586  */
15587 static struct mbuf *
15588 rack_fo_m_copym(struct tcp_rack *rack, int32_t *plen,
15589 		int32_t seglimit, int32_t segsize, struct mbuf **s_mb, int *s_soff)
15590 {
15591 	struct mbuf *m, *n;
15592 	int32_t soff;
15593 
15594 	soff = rack->r_ctl.fsb.off;
15595 	m = rack->r_ctl.fsb.m;
15596 	if (rack->r_ctl.fsb.o_m_len > m->m_len) {
15597 		/*
15598 		 * The mbuf had the front of it chopped off by an ack
15599 		 * we need to adjust the soff/off by that difference.
15600 		 */
15601 		uint32_t delta;
15602 
15603 		delta = rack->r_ctl.fsb.o_m_len - m->m_len;
15604 		soff -= delta;
15605 	} else if (rack->r_ctl.fsb.o_m_len < m->m_len) {
15606 		/*
15607 		 * The mbuf was expanded probably by
15608 		 * a m_compress. Just update o_m_len.
15609 		 */
15610 		rack->r_ctl.fsb.o_m_len = m->m_len;
15611 	}
15612 	KASSERT(soff >= 0, ("%s, negative off %d", __FUNCTION__, soff));
15613 	KASSERT(*plen >= 0, ("%s, negative len %d", __FUNCTION__, *plen));
15614 	KASSERT(soff < m->m_len, ("%s rack:%p len:%u m:%p m->m_len:%u < off?",
15615 				 __FUNCTION__,
15616 				 rack, *plen, m, m->m_len));
15617 	/* Save off the right location before we copy and advance */
15618 	*s_soff = soff;
15619 	*s_mb = rack->r_ctl.fsb.m;
15620 	n = rack_fo_base_copym(m, soff, plen,
15621 			       &rack->r_ctl.fsb,
15622 			       seglimit, segsize, rack->r_ctl.fsb.hw_tls);
15623 	return (n);
15624 }
15625 
15626 static int
15627 rack_fast_rsm_output(struct tcpcb *tp, struct tcp_rack *rack, struct rack_sendmap *rsm,
15628 		     uint64_t ts_val, uint32_t cts, uint32_t ms_cts, struct timeval *tv, int len, uint8_t doing_tlp)
15629 {
15630 	/*
15631 	 * Enter the fast retransmit path. We are given that a sched_pin is
15632 	 * in place (if accounting is compliled in) and the cycle count taken
15633 	 * at the entry is in the ts_val. The concept her is that the rsm
15634 	 * now holds the mbuf offsets and such so we can directly transmit
15635 	 * without a lot of overhead, the len field is already set for
15636 	 * us to prohibit us from sending too much (usually its 1MSS).
15637 	 */
15638 	struct ip *ip = NULL;
15639 	struct udphdr *udp = NULL;
15640 	struct tcphdr *th = NULL;
15641 	struct mbuf *m = NULL;
15642 	struct inpcb *inp;
15643 	uint8_t *cpto;
15644 	struct tcp_log_buffer *lgb;
15645 #ifdef TCP_ACCOUNTING
15646 	uint64_t crtsc;
15647 	int cnt_thru = 1;
15648 #endif
15649 	struct tcpopt to;
15650 	u_char opt[TCP_MAXOLEN];
15651 	uint32_t hdrlen, optlen;
15652 	int32_t slot, segsiz, max_val, tso = 0, error, ulen = 0;
15653 	uint16_t flags;
15654 	uint32_t if_hw_tsomaxsegcount = 0, startseq;
15655 	uint32_t if_hw_tsomaxsegsize;
15656 
15657 #ifdef INET6
15658 	struct ip6_hdr *ip6 = NULL;
15659 
15660 	if (rack->r_is_v6) {
15661 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
15662 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
15663 	} else
15664 #endif				/* INET6 */
15665 	{
15666 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
15667 		hdrlen = sizeof(struct tcpiphdr);
15668 	}
15669 	if (tp->t_port && (V_tcp_udp_tunneling_port == 0)) {
15670 		goto failed;
15671 	}
15672 	if (doing_tlp) {
15673 		/* Its a TLP add the flag, it may already be there but be sure */
15674 		rsm->r_flags |= RACK_TLP;
15675 	} else {
15676 		/* If it was a TLP it is not not on this retransmit */
15677 		rsm->r_flags &= ~RACK_TLP;
15678 	}
15679 	startseq = rsm->r_start;
15680 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
15681 	inp = rack->rc_inp;
15682 	to.to_flags = 0;
15683 	flags = tcp_outflags[tp->t_state];
15684 	if (flags & (TH_SYN|TH_RST)) {
15685 		goto failed;
15686 	}
15687 	if (rsm->r_flags & RACK_HAS_FIN) {
15688 		/* We can't send a FIN here */
15689 		goto failed;
15690 	}
15691 	if (flags & TH_FIN) {
15692 		/* We never send a FIN */
15693 		flags &= ~TH_FIN;
15694 	}
15695 	if (tp->t_flags & TF_RCVD_TSTMP) {
15696 		to.to_tsval = ms_cts + tp->ts_offset;
15697 		to.to_tsecr = tp->ts_recent;
15698 		to.to_flags = TOF_TS;
15699 	}
15700 	optlen = tcp_addoptions(&to, opt);
15701 	hdrlen += optlen;
15702 	udp = rack->r_ctl.fsb.udp;
15703 	if (udp)
15704 		hdrlen += sizeof(struct udphdr);
15705 	if (rack->r_ctl.rc_pace_max_segs)
15706 		max_val = rack->r_ctl.rc_pace_max_segs;
15707 	else if (rack->rc_user_set_max_segs)
15708 		max_val = rack->rc_user_set_max_segs * segsiz;
15709 	else
15710 		max_val = len;
15711 	if ((tp->t_flags & TF_TSO) &&
15712 	    V_tcp_do_tso &&
15713 	    (len > segsiz) &&
15714 	    (tp->t_port == 0))
15715 		tso = 1;
15716 #ifdef INET6
15717 	if (MHLEN < hdrlen + max_linkhdr)
15718 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
15719 	else
15720 #endif
15721 		m = m_gethdr(M_NOWAIT, MT_DATA);
15722 	if (m == NULL)
15723 		goto failed;
15724 	m->m_data += max_linkhdr;
15725 	m->m_len = hdrlen;
15726 	th = rack->r_ctl.fsb.th;
15727 	/* Establish the len to send */
15728 	if (len > max_val)
15729 		len = max_val;
15730 	if ((tso) && (len + optlen > tp->t_maxseg)) {
15731 		uint32_t if_hw_tsomax;
15732 		int32_t max_len;
15733 
15734 		/* extract TSO information */
15735 		if_hw_tsomax = tp->t_tsomax;
15736 		if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
15737 		if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
15738 		/*
15739 		 * Check if we should limit by maximum payload
15740 		 * length:
15741 		 */
15742 		if (if_hw_tsomax != 0) {
15743 			/* compute maximum TSO length */
15744 			max_len = (if_hw_tsomax - hdrlen -
15745 				   max_linkhdr);
15746 			if (max_len <= 0) {
15747 				goto failed;
15748 			} else if (len > max_len) {
15749 				len = max_len;
15750 			}
15751 		}
15752 		if (len <= segsiz) {
15753 			/*
15754 			 * In case there are too many small fragments don't
15755 			 * use TSO:
15756 			 */
15757 			tso = 0;
15758 		}
15759 	} else {
15760 		tso = 0;
15761 	}
15762 	if ((tso == 0) && (len > segsiz))
15763 		len = segsiz;
15764 	if ((len == 0) ||
15765 	    (len <= MHLEN - hdrlen - max_linkhdr)) {
15766 		goto failed;
15767 	}
15768 	th->th_seq = htonl(rsm->r_start);
15769 	th->th_ack = htonl(tp->rcv_nxt);
15770 	/*
15771 	 * The PUSH bit should only be applied
15772 	 * if the full retransmission is made. If
15773 	 * we are sending less than this is the
15774 	 * left hand edge and should not have
15775 	 * the PUSH bit.
15776 	 */
15777 	if ((rsm->r_flags & RACK_HAD_PUSH) &&
15778 	    (len == (rsm->r_end - rsm->r_start)))
15779 		flags |= TH_PUSH;
15780 	th->th_win = htons((u_short)(rack->r_ctl.fsb.recwin >> tp->rcv_scale));
15781 	if (th->th_win == 0) {
15782 		tp->t_sndzerowin++;
15783 		tp->t_flags |= TF_RXWIN0SENT;
15784 	} else
15785 		tp->t_flags &= ~TF_RXWIN0SENT;
15786 	if (rsm->r_flags & RACK_TLP) {
15787 		/*
15788 		 * TLP should not count in retran count, but
15789 		 * in its own bin
15790 		 */
15791 		counter_u64_add(rack_tlp_retran, 1);
15792 		counter_u64_add(rack_tlp_retran_bytes, len);
15793 	} else {
15794 		tp->t_sndrexmitpack++;
15795 		KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
15796 		KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
15797 	}
15798 #ifdef STATS
15799 	stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
15800 				 len);
15801 #endif
15802 	if (rsm->m == NULL)
15803 		goto failed;
15804 	if (rsm->orig_m_len != rsm->m->m_len) {
15805 		/* Fix up the orig_m_len and possibly the mbuf offset */
15806 		rack_adjust_orig_mlen(rsm);
15807 	}
15808 	m->m_next = rack_fo_base_copym(rsm->m, rsm->soff, &len, NULL, if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, rsm->r_hw_tls);
15809 	if (len <= segsiz) {
15810 		/*
15811 		 * Must have ran out of mbufs for the copy
15812 		 * shorten it to no longer need tso. Lets
15813 		 * not put on sendalot since we are low on
15814 		 * mbufs.
15815 		 */
15816 		tso = 0;
15817 	}
15818 	if ((m->m_next == NULL) || (len <= 0)){
15819 		goto failed;
15820 	}
15821 	if (udp) {
15822 		if (rack->r_is_v6)
15823 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
15824 		else
15825 			ulen = hdrlen + len - sizeof(struct ip);
15826 		udp->uh_ulen = htons(ulen);
15827 	}
15828 	m->m_pkthdr.rcvif = (struct ifnet *)0;
15829 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
15830 	    (tp->t_flags2 & TF2_ECN_PERMIT)) {
15831 		int ect = tcp_ecn_output_established(tp, &flags, len, true);
15832 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
15833 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
15834 		    tp->t_flags2 &= ~TF2_ECN_SND_ECE;
15835 #ifdef INET6
15836 		if (rack->r_is_v6) {
15837 		    ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
15838 		    ip6->ip6_flow |= htonl(ect << 20);
15839 		}
15840 		else
15841 #endif
15842 		{
15843 		    ip->ip_tos &= ~IPTOS_ECN_MASK;
15844 		    ip->ip_tos |= ect;
15845 		}
15846 	}
15847 	tcp_set_flags(th, flags);
15848 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
15849 #ifdef INET6
15850 	if (rack->r_is_v6) {
15851 		if (tp->t_port) {
15852 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
15853 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
15854 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
15855 			th->th_sum = htons(0);
15856 			UDPSTAT_INC(udps_opackets);
15857 		} else {
15858 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
15859 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
15860 			th->th_sum = in6_cksum_pseudo(ip6,
15861 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
15862 						      0);
15863 		}
15864 	}
15865 #endif
15866 #if defined(INET6) && defined(INET)
15867 	else
15868 #endif
15869 #ifdef INET
15870 	{
15871 		if (tp->t_port) {
15872 			m->m_pkthdr.csum_flags = CSUM_UDP;
15873 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
15874 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
15875 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
15876 			th->th_sum = htons(0);
15877 			UDPSTAT_INC(udps_opackets);
15878 		} else {
15879 			m->m_pkthdr.csum_flags = CSUM_TCP;
15880 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
15881 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
15882 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
15883 									IPPROTO_TCP + len + optlen));
15884 		}
15885 		/* IP version must be set here for ipv4/ipv6 checking later */
15886 		KASSERT(ip->ip_v == IPVERSION,
15887 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
15888 	}
15889 #endif
15890 	if (tso) {
15891 		KASSERT(len > tp->t_maxseg - optlen,
15892 			("%s: len <= tso_segsz tp:%p", __func__, tp));
15893 		m->m_pkthdr.csum_flags |= CSUM_TSO;
15894 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
15895 	}
15896 #ifdef INET6
15897 	if (rack->r_is_v6) {
15898 		ip6->ip6_hlim = rack->r_ctl.fsb.hoplimit;
15899 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
15900 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
15901 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
15902 		else
15903 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
15904 	}
15905 #endif
15906 #if defined(INET) && defined(INET6)
15907 	else
15908 #endif
15909 #ifdef INET
15910 	{
15911 		ip->ip_len = htons(m->m_pkthdr.len);
15912 		ip->ip_ttl = rack->r_ctl.fsb.hoplimit;
15913 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
15914 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
15915 			if (tp->t_port == 0 || len < V_tcp_minmss) {
15916 				ip->ip_off |= htons(IP_DF);
15917 			}
15918 		} else {
15919 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
15920 		}
15921 	}
15922 #endif
15923 	/* Time to copy in our header */
15924 	cpto = mtod(m, uint8_t *);
15925 	memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
15926 	th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
15927 	if (optlen) {
15928 		bcopy(opt, th + 1, optlen);
15929 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
15930 	} else {
15931 		th->th_off = sizeof(struct tcphdr) >> 2;
15932 	}
15933 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
15934 		union tcp_log_stackspecific log;
15935 
15936 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
15937 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
15938 		if (rack->rack_no_prr)
15939 			log.u_bbr.flex1 = 0;
15940 		else
15941 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
15942 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
15943 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
15944 		log.u_bbr.flex4 = max_val;
15945 		log.u_bbr.flex5 = 0;
15946 		/* Save off the early/late values */
15947 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
15948 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
15949 		log.u_bbr.bw_inuse = rack_get_bw(rack);
15950 		if (doing_tlp == 0)
15951 			log.u_bbr.flex8 = 1;
15952 		else
15953 			log.u_bbr.flex8 = 2;
15954 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
15955 		log.u_bbr.flex7 = 55;
15956 		log.u_bbr.pkts_out = tp->t_maxseg;
15957 		log.u_bbr.timeStamp = cts;
15958 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
15959 		log.u_bbr.lt_epoch = rack->r_ctl.cwnd_to_use;
15960 		log.u_bbr.delivered = 0;
15961 		lgb = tcp_log_event_(tp, th, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
15962 				     len, &log, false, NULL, NULL, 0, tv);
15963 	} else
15964 		lgb = NULL;
15965 #ifdef INET6
15966 	if (rack->r_is_v6) {
15967 		error = ip6_output(m, NULL,
15968 				   &inp->inp_route6,
15969 				   0, NULL, NULL, inp);
15970 	}
15971 #endif
15972 #if defined(INET) && defined(INET6)
15973 	else
15974 #endif
15975 #ifdef INET
15976 	{
15977 		error = ip_output(m, NULL,
15978 				  &inp->inp_route,
15979 				  0, 0, inp);
15980 	}
15981 #endif
15982 	m = NULL;
15983 	if (lgb) {
15984 		lgb->tlb_errno = error;
15985 		lgb = NULL;
15986 	}
15987 	if (error) {
15988 		goto failed;
15989 	}
15990 	rack_log_output(tp, &to, len, rsm->r_start, flags, error, rack_to_usec_ts(tv),
15991 			rsm, RACK_SENT_FP, rsm->m, rsm->soff, rsm->r_hw_tls);
15992 	if (doing_tlp && (rack->fast_rsm_hack == 0)) {
15993 		rack->rc_tlp_in_progress = 1;
15994 		rack->r_ctl.rc_tlp_cnt_out++;
15995 	}
15996 	if (error == 0) {
15997 		tcp_account_for_send(tp, len, 1, doing_tlp, rsm->r_hw_tls);
15998 		if (doing_tlp) {
15999 			rack->rc_last_sent_tlp_past_cumack = 0;
16000 			rack->rc_last_sent_tlp_seq_valid = 1;
16001 			rack->r_ctl.last_sent_tlp_seq = rsm->r_start;
16002 			rack->r_ctl.last_sent_tlp_len = rsm->r_end - rsm->r_start;
16003 		}
16004 	}
16005 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
16006 	rack->forced_ack = 0;	/* If we send something zap the FA flag */
16007 	if (IN_FASTRECOVERY(tp->t_flags) && rsm)
16008 		rack->r_ctl.retran_during_recovery += len;
16009 	{
16010 		int idx;
16011 
16012 		idx = (len / segsiz) + 3;
16013 		if (idx >= TCP_MSS_ACCT_ATIMER)
16014 			counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
16015 		else
16016 			counter_u64_add(rack_out_size[idx], 1);
16017 	}
16018 	if (tp->t_rtttime == 0) {
16019 		tp->t_rtttime = ticks;
16020 		tp->t_rtseq = startseq;
16021 		KMOD_TCPSTAT_INC(tcps_segstimed);
16022 	}
16023 	counter_u64_add(rack_fto_rsm_send, 1);
16024 	if (error && (error == ENOBUFS)) {
16025 		if (rack->r_ctl.crte != NULL) {
16026 			rack_trace_point(rack, RACK_TP_HWENOBUF);
16027 		} else
16028 			rack_trace_point(rack, RACK_TP_ENOBUF);
16029 		slot = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
16030 		if (rack->rc_enobuf < 0x7f)
16031 			rack->rc_enobuf++;
16032 		if (slot < (10 * HPTS_USEC_IN_MSEC))
16033 			slot = 10 * HPTS_USEC_IN_MSEC;
16034 	} else
16035 		slot = rack_get_pacing_delay(rack, tp, len, NULL, segsiz);
16036 	if ((slot == 0) ||
16037 	    (rack->rc_always_pace == 0) ||
16038 	    (rack->r_rr_config == 1)) {
16039 		/*
16040 		 * We have no pacing set or we
16041 		 * are using old-style rack or
16042 		 * we are overriden to use the old 1ms pacing.
16043 		 */
16044 		slot = rack->r_ctl.rc_min_to;
16045 	}
16046 	rack_start_hpts_timer(rack, tp, cts, slot, len, 0);
16047 #ifdef TCP_ACCOUNTING
16048 	crtsc = get_cyclecount();
16049 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16050 		tp->tcp_cnt_counters[SND_OUT_DATA] += cnt_thru;
16051 	}
16052 	counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], cnt_thru);
16053 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16054 		tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
16055 	}
16056 	counter_u64_add(tcp_proc_time[SND_OUT_DATA], (crtsc - ts_val));
16057 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16058 		tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((len + segsiz - 1) / segsiz);
16059 	}
16060 	counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((len + segsiz - 1) / segsiz));
16061 	sched_unpin();
16062 #endif
16063 	return (0);
16064 failed:
16065 	if (m)
16066 		m_free(m);
16067 	return (-1);
16068 }
16069 
16070 static void
16071 rack_sndbuf_autoscale(struct tcp_rack *rack)
16072 {
16073 	/*
16074 	 * Automatic sizing of send socket buffer.  Often the send buffer
16075 	 * size is not optimally adjusted to the actual network conditions
16076 	 * at hand (delay bandwidth product).  Setting the buffer size too
16077 	 * small limits throughput on links with high bandwidth and high
16078 	 * delay (eg. trans-continental/oceanic links).  Setting the
16079 	 * buffer size too big consumes too much real kernel memory,
16080 	 * especially with many connections on busy servers.
16081 	 *
16082 	 * The criteria to step up the send buffer one notch are:
16083 	 *  1. receive window of remote host is larger than send buffer
16084 	 *     (with a fudge factor of 5/4th);
16085 	 *  2. send buffer is filled to 7/8th with data (so we actually
16086 	 *     have data to make use of it);
16087 	 *  3. send buffer fill has not hit maximal automatic size;
16088 	 *  4. our send window (slow start and cogestion controlled) is
16089 	 *     larger than sent but unacknowledged data in send buffer.
16090 	 *
16091 	 * Note that the rack version moves things much faster since
16092 	 * we want to avoid hitting cache lines in the rack_fast_output()
16093 	 * path so this is called much less often and thus moves
16094 	 * the SB forward by a percentage.
16095 	 */
16096 	struct socket *so;
16097 	struct tcpcb *tp;
16098 	uint32_t sendwin, scaleup;
16099 
16100 	tp = rack->rc_tp;
16101 	so = rack->rc_inp->inp_socket;
16102 	sendwin = min(rack->r_ctl.cwnd_to_use, tp->snd_wnd);
16103 	if (V_tcp_do_autosndbuf && so->so_snd.sb_flags & SB_AUTOSIZE) {
16104 		if ((tp->snd_wnd / 4 * 5) >= so->so_snd.sb_hiwat &&
16105 		    sbused(&so->so_snd) >=
16106 		    (so->so_snd.sb_hiwat / 8 * 7) &&
16107 		    sbused(&so->so_snd) < V_tcp_autosndbuf_max &&
16108 		    sendwin >= (sbused(&so->so_snd) -
16109 		    (tp->snd_nxt - tp->snd_una))) {
16110 			if (rack_autosndbuf_inc)
16111 				scaleup = (rack_autosndbuf_inc * so->so_snd.sb_hiwat) / 100;
16112 			else
16113 				scaleup = V_tcp_autosndbuf_inc;
16114 			if (scaleup < V_tcp_autosndbuf_inc)
16115 				scaleup = V_tcp_autosndbuf_inc;
16116 			scaleup += so->so_snd.sb_hiwat;
16117 			if (scaleup > V_tcp_autosndbuf_max)
16118 				scaleup = V_tcp_autosndbuf_max;
16119 			if (!sbreserve_locked(so, SO_SND, scaleup, curthread))
16120 				so->so_snd.sb_flags &= ~SB_AUTOSIZE;
16121 		}
16122 	}
16123 }
16124 
16125 static int
16126 rack_fast_output(struct tcpcb *tp, struct tcp_rack *rack, uint64_t ts_val,
16127 		 uint32_t cts, uint32_t ms_cts, struct timeval *tv, long tot_len, int *send_err)
16128 {
16129 	/*
16130 	 * Enter to do fast output. We are given that the sched_pin is
16131 	 * in place (if accounting is compiled in) and the cycle count taken
16132 	 * at entry is in place in ts_val. The idea here is that
16133 	 * we know how many more bytes needs to be sent (presumably either
16134 	 * during pacing or to fill the cwnd and that was greater than
16135 	 * the max-burst). We have how much to send and all the info we
16136 	 * need to just send.
16137 	 */
16138 	struct ip *ip = NULL;
16139 	struct udphdr *udp = NULL;
16140 	struct tcphdr *th = NULL;
16141 	struct mbuf *m, *s_mb;
16142 	struct inpcb *inp;
16143 	uint8_t *cpto;
16144 	struct tcp_log_buffer *lgb;
16145 #ifdef TCP_ACCOUNTING
16146 	uint64_t crtsc;
16147 #endif
16148 	struct tcpopt to;
16149 	u_char opt[TCP_MAXOLEN];
16150 	uint32_t hdrlen, optlen;
16151 	int cnt_thru = 1;
16152 	int32_t slot, segsiz, len, max_val, tso = 0, sb_offset, error, ulen = 0;
16153 	uint16_t flags;
16154 	uint32_t s_soff;
16155 	uint32_t if_hw_tsomaxsegcount = 0, startseq;
16156 	uint32_t if_hw_tsomaxsegsize;
16157 	uint16_t add_flag = RACK_SENT_FP;
16158 #ifdef INET6
16159 	struct ip6_hdr *ip6 = NULL;
16160 
16161 	if (rack->r_is_v6) {
16162 		ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
16163 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
16164 	} else
16165 #endif				/* INET6 */
16166 	{
16167 		ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
16168 		hdrlen = sizeof(struct tcpiphdr);
16169 	}
16170 	if (tp->t_port && (V_tcp_udp_tunneling_port == 0)) {
16171 		m = NULL;
16172 		goto failed;
16173 	}
16174 	startseq = tp->snd_max;
16175 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
16176 	inp = rack->rc_inp;
16177 	len = rack->r_ctl.fsb.left_to_send;
16178 	to.to_flags = 0;
16179 	flags = rack->r_ctl.fsb.tcp_flags;
16180 	if (tp->t_flags & TF_RCVD_TSTMP) {
16181 		to.to_tsval = ms_cts + tp->ts_offset;
16182 		to.to_tsecr = tp->ts_recent;
16183 		to.to_flags = TOF_TS;
16184 	}
16185 	optlen = tcp_addoptions(&to, opt);
16186 	hdrlen += optlen;
16187 	udp = rack->r_ctl.fsb.udp;
16188 	if (udp)
16189 		hdrlen += sizeof(struct udphdr);
16190 	if (rack->r_ctl.rc_pace_max_segs)
16191 		max_val = rack->r_ctl.rc_pace_max_segs;
16192 	else if (rack->rc_user_set_max_segs)
16193 		max_val = rack->rc_user_set_max_segs * segsiz;
16194 	else
16195 		max_val = len;
16196 	if ((tp->t_flags & TF_TSO) &&
16197 	    V_tcp_do_tso &&
16198 	    (len > segsiz) &&
16199 	    (tp->t_port == 0))
16200 		tso = 1;
16201 again:
16202 #ifdef INET6
16203 	if (MHLEN < hdrlen + max_linkhdr)
16204 		m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
16205 	else
16206 #endif
16207 		m = m_gethdr(M_NOWAIT, MT_DATA);
16208 	if (m == NULL)
16209 		goto failed;
16210 	m->m_data += max_linkhdr;
16211 	m->m_len = hdrlen;
16212 	th = rack->r_ctl.fsb.th;
16213 	/* Establish the len to send */
16214 	if (len > max_val)
16215 		len = max_val;
16216 	if ((tso) && (len + optlen > tp->t_maxseg)) {
16217 		uint32_t if_hw_tsomax;
16218 		int32_t max_len;
16219 
16220 		/* extract TSO information */
16221 		if_hw_tsomax = tp->t_tsomax;
16222 		if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
16223 		if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
16224 		/*
16225 		 * Check if we should limit by maximum payload
16226 		 * length:
16227 		 */
16228 		if (if_hw_tsomax != 0) {
16229 			/* compute maximum TSO length */
16230 			max_len = (if_hw_tsomax - hdrlen -
16231 				   max_linkhdr);
16232 			if (max_len <= 0) {
16233 				goto failed;
16234 			} else if (len > max_len) {
16235 				len = max_len;
16236 			}
16237 		}
16238 		if (len <= segsiz) {
16239 			/*
16240 			 * In case there are too many small fragments don't
16241 			 * use TSO:
16242 			 */
16243 			tso = 0;
16244 		}
16245 	} else {
16246 		tso = 0;
16247 	}
16248 	if ((tso == 0) && (len > segsiz))
16249 		len = segsiz;
16250 	if ((len == 0) ||
16251 	    (len <= MHLEN - hdrlen - max_linkhdr)) {
16252 		goto failed;
16253 	}
16254 	sb_offset = tp->snd_max - tp->snd_una;
16255 	th->th_seq = htonl(tp->snd_max);
16256 	th->th_ack = htonl(tp->rcv_nxt);
16257 	th->th_win = htons((u_short)(rack->r_ctl.fsb.recwin >> tp->rcv_scale));
16258 	if (th->th_win == 0) {
16259 		tp->t_sndzerowin++;
16260 		tp->t_flags |= TF_RXWIN0SENT;
16261 	} else
16262 		tp->t_flags &= ~TF_RXWIN0SENT;
16263 	tp->snd_up = tp->snd_una;	/* drag it along, its deprecated */
16264 	KMOD_TCPSTAT_INC(tcps_sndpack);
16265 	KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
16266 #ifdef STATS
16267 	stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
16268 				 len);
16269 #endif
16270 	if (rack->r_ctl.fsb.m == NULL)
16271 		goto failed;
16272 
16273 	/* s_mb and s_soff are saved for rack_log_output */
16274 	m->m_next = rack_fo_m_copym(rack, &len, if_hw_tsomaxsegcount, if_hw_tsomaxsegsize,
16275 				    &s_mb, &s_soff);
16276 	if (len <= segsiz) {
16277 		/*
16278 		 * Must have ran out of mbufs for the copy
16279 		 * shorten it to no longer need tso. Lets
16280 		 * not put on sendalot since we are low on
16281 		 * mbufs.
16282 		 */
16283 		tso = 0;
16284 	}
16285 	if (rack->r_ctl.fsb.rfo_apply_push &&
16286 	    (len == rack->r_ctl.fsb.left_to_send)) {
16287 		flags |= TH_PUSH;
16288 		add_flag |= RACK_HAD_PUSH;
16289 	}
16290 	if ((m->m_next == NULL) || (len <= 0)){
16291 		goto failed;
16292 	}
16293 	if (udp) {
16294 		if (rack->r_is_v6)
16295 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
16296 		else
16297 			ulen = hdrlen + len - sizeof(struct ip);
16298 		udp->uh_ulen = htons(ulen);
16299 	}
16300 	m->m_pkthdr.rcvif = (struct ifnet *)0;
16301 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
16302 	    (tp->t_flags2 & TF2_ECN_PERMIT)) {
16303 		int ect = tcp_ecn_output_established(tp, &flags, len, false);
16304 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
16305 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
16306 			tp->t_flags2 &= ~TF2_ECN_SND_ECE;
16307 #ifdef INET6
16308 		if (rack->r_is_v6) {
16309 			ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
16310 			ip6->ip6_flow |= htonl(ect << 20);
16311 		}
16312 		else
16313 #endif
16314 		{
16315 			ip->ip_tos &= ~IPTOS_ECN_MASK;
16316 			ip->ip_tos |= ect;
16317 		}
16318 	}
16319 	tcp_set_flags(th, flags);
16320 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
16321 #ifdef INET6
16322 	if (rack->r_is_v6) {
16323 		if (tp->t_port) {
16324 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
16325 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
16326 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
16327 			th->th_sum = htons(0);
16328 			UDPSTAT_INC(udps_opackets);
16329 		} else {
16330 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
16331 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
16332 			th->th_sum = in6_cksum_pseudo(ip6,
16333 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
16334 						      0);
16335 		}
16336 	}
16337 #endif
16338 #if defined(INET6) && defined(INET)
16339 	else
16340 #endif
16341 #ifdef INET
16342 	{
16343 		if (tp->t_port) {
16344 			m->m_pkthdr.csum_flags = CSUM_UDP;
16345 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
16346 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
16347 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
16348 			th->th_sum = htons(0);
16349 			UDPSTAT_INC(udps_opackets);
16350 		} else {
16351 			m->m_pkthdr.csum_flags = CSUM_TCP;
16352 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
16353 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
16354 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
16355 									IPPROTO_TCP + len + optlen));
16356 		}
16357 		/* IP version must be set here for ipv4/ipv6 checking later */
16358 		KASSERT(ip->ip_v == IPVERSION,
16359 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
16360 	}
16361 #endif
16362 	if (tso) {
16363 		KASSERT(len > tp->t_maxseg - optlen,
16364 			("%s: len <= tso_segsz tp:%p", __func__, tp));
16365 		m->m_pkthdr.csum_flags |= CSUM_TSO;
16366 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
16367 	}
16368 #ifdef INET6
16369 	if (rack->r_is_v6) {
16370 		ip6->ip6_hlim = rack->r_ctl.fsb.hoplimit;
16371 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
16372 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
16373 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
16374 		else
16375 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
16376 	}
16377 #endif
16378 #if defined(INET) && defined(INET6)
16379 	else
16380 #endif
16381 #ifdef INET
16382 	{
16383 		ip->ip_len = htons(m->m_pkthdr.len);
16384 		ip->ip_ttl = rack->r_ctl.fsb.hoplimit;
16385 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
16386 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
16387 			if (tp->t_port == 0 || len < V_tcp_minmss) {
16388 				ip->ip_off |= htons(IP_DF);
16389 			}
16390 		} else {
16391 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
16392 		}
16393 	}
16394 #endif
16395 	/* Time to copy in our header */
16396 	cpto = mtod(m, uint8_t *);
16397 	memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
16398 	th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
16399 	if (optlen) {
16400 		bcopy(opt, th + 1, optlen);
16401 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
16402 	} else {
16403 		th->th_off = sizeof(struct tcphdr) >> 2;
16404 	}
16405 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
16406 		union tcp_log_stackspecific log;
16407 
16408 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
16409 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
16410 		if (rack->rack_no_prr)
16411 			log.u_bbr.flex1 = 0;
16412 		else
16413 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
16414 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
16415 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
16416 		log.u_bbr.flex4 = max_val;
16417 		log.u_bbr.flex5 = 0;
16418 		/* Save off the early/late values */
16419 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
16420 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
16421 		log.u_bbr.bw_inuse = rack_get_bw(rack);
16422 		log.u_bbr.flex8 = 0;
16423 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, NULL);
16424 		log.u_bbr.flex7 = 44;
16425 		log.u_bbr.pkts_out = tp->t_maxseg;
16426 		log.u_bbr.timeStamp = cts;
16427 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
16428 		log.u_bbr.lt_epoch = rack->r_ctl.cwnd_to_use;
16429 		log.u_bbr.delivered = 0;
16430 		lgb = tcp_log_event_(tp, th, NULL, NULL, TCP_LOG_OUT, ERRNO_UNK,
16431 				     len, &log, false, NULL, NULL, 0, tv);
16432 	} else
16433 		lgb = NULL;
16434 #ifdef INET6
16435 	if (rack->r_is_v6) {
16436 		error = ip6_output(m, NULL,
16437 				   &inp->inp_route6,
16438 				   0, NULL, NULL, inp);
16439 	}
16440 #endif
16441 #if defined(INET) && defined(INET6)
16442 	else
16443 #endif
16444 #ifdef INET
16445 	{
16446 		error = ip_output(m, NULL,
16447 				  &inp->inp_route,
16448 				  0, 0, inp);
16449 	}
16450 #endif
16451 	if (lgb) {
16452 		lgb->tlb_errno = error;
16453 		lgb = NULL;
16454 	}
16455 	if (error) {
16456 		*send_err = error;
16457 		m = NULL;
16458 		goto failed;
16459 	}
16460 	rack_log_output(tp, &to, len, tp->snd_max, flags, error, rack_to_usec_ts(tv),
16461 			NULL, add_flag, s_mb, s_soff, rack->r_ctl.fsb.hw_tls);
16462 	m = NULL;
16463 	if (tp->snd_una == tp->snd_max) {
16464 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
16465 		rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
16466 		tp->t_acktime = ticks;
16467 	}
16468 	if (error == 0)
16469 		tcp_account_for_send(tp, len, 0, 0, rack->r_ctl.fsb.hw_tls);
16470 
16471 	rack->forced_ack = 0;	/* If we send something zap the FA flag */
16472 	tot_len += len;
16473 	if ((tp->t_flags & TF_GPUTINPROG) == 0)
16474 		rack_start_gp_measurement(tp, rack, tp->snd_max, sb_offset);
16475 	tp->snd_max += len;
16476 	tp->snd_nxt = tp->snd_max;
16477 	{
16478 		int idx;
16479 
16480 		idx = (len / segsiz) + 3;
16481 		if (idx >= TCP_MSS_ACCT_ATIMER)
16482 			counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
16483 		else
16484 			counter_u64_add(rack_out_size[idx], 1);
16485 	}
16486 	if (len <= rack->r_ctl.fsb.left_to_send)
16487 		rack->r_ctl.fsb.left_to_send -= len;
16488 	else
16489 		rack->r_ctl.fsb.left_to_send = 0;
16490 	if (rack->r_ctl.fsb.left_to_send < segsiz) {
16491 		rack->r_fast_output = 0;
16492 		rack->r_ctl.fsb.left_to_send = 0;
16493 		/* At the end of fast_output scale up the sb */
16494 		SOCKBUF_LOCK(&rack->rc_inp->inp_socket->so_snd);
16495 		rack_sndbuf_autoscale(rack);
16496 		SOCKBUF_UNLOCK(&rack->rc_inp->inp_socket->so_snd);
16497 	}
16498 	if (tp->t_rtttime == 0) {
16499 		tp->t_rtttime = ticks;
16500 		tp->t_rtseq = startseq;
16501 		KMOD_TCPSTAT_INC(tcps_segstimed);
16502 	}
16503 	if ((rack->r_ctl.fsb.left_to_send >= segsiz) &&
16504 	    (max_val > len) &&
16505 	    (tso == 0)) {
16506 		max_val -= len;
16507 		len = segsiz;
16508 		th = rack->r_ctl.fsb.th;
16509 		cnt_thru++;
16510 		goto again;
16511 	}
16512 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
16513 	counter_u64_add(rack_fto_send, 1);
16514 	slot = rack_get_pacing_delay(rack, tp, tot_len, NULL, segsiz);
16515 	rack_start_hpts_timer(rack, tp, cts, slot, tot_len, 0);
16516 #ifdef TCP_ACCOUNTING
16517 	crtsc = get_cyclecount();
16518 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16519 		tp->tcp_cnt_counters[SND_OUT_DATA] += cnt_thru;
16520 	}
16521 	counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], cnt_thru);
16522 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16523 		tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
16524 	}
16525 	counter_u64_add(tcp_proc_time[SND_OUT_DATA], (crtsc - ts_val));
16526 	if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16527 		tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len + segsiz - 1) / segsiz);
16528 	}
16529 	counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((tot_len + segsiz - 1) / segsiz));
16530 	sched_unpin();
16531 #endif
16532 	return (0);
16533 failed:
16534 	if (m)
16535 		m_free(m);
16536 	rack->r_fast_output = 0;
16537 	return (-1);
16538 }
16539 
16540 static int
16541 rack_output(struct tcpcb *tp)
16542 {
16543 	struct socket *so;
16544 	uint32_t recwin;
16545 	uint32_t sb_offset, s_moff = 0;
16546 	int32_t len, error = 0;
16547 	uint16_t flags;
16548 	struct mbuf *m, *s_mb = NULL;
16549 	struct mbuf *mb;
16550 	uint32_t if_hw_tsomaxsegcount = 0;
16551 	uint32_t if_hw_tsomaxsegsize;
16552 	int32_t segsiz, minseg;
16553 	long tot_len_this_send = 0;
16554 #ifdef INET
16555 	struct ip *ip = NULL;
16556 #endif
16557 	struct udphdr *udp = NULL;
16558 	struct tcp_rack *rack;
16559 	struct tcphdr *th;
16560 	uint8_t pass = 0;
16561 	uint8_t mark = 0;
16562 	uint8_t wanted_cookie = 0;
16563 	u_char opt[TCP_MAXOLEN];
16564 	unsigned ipoptlen, optlen, hdrlen, ulen=0;
16565 	uint32_t rack_seq;
16566 
16567 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
16568 	unsigned ipsec_optlen = 0;
16569 
16570 #endif
16571 	int32_t idle, sendalot;
16572 	int32_t sub_from_prr = 0;
16573 	volatile int32_t sack_rxmit;
16574 	struct rack_sendmap *rsm = NULL;
16575 	int32_t tso, mtu;
16576 	struct tcpopt to;
16577 	int32_t slot = 0;
16578 	int32_t sup_rack = 0;
16579 	uint32_t cts, ms_cts, delayed, early;
16580 	uint16_t add_flag = RACK_SENT_SP;
16581 	/* The doing_tlp flag will be set by the actual rack_timeout_tlp() */
16582 	uint8_t hpts_calling,  doing_tlp = 0;
16583 	uint32_t cwnd_to_use, pace_max_seg;
16584 	int32_t do_a_prefetch = 0;
16585 	int32_t prefetch_rsm = 0;
16586 	int32_t orig_len = 0;
16587 	struct timeval tv;
16588 	int32_t prefetch_so_done = 0;
16589 	struct tcp_log_buffer *lgb;
16590 	struct inpcb *inp;
16591 	struct sockbuf *sb;
16592 	uint64_t ts_val = 0;
16593 #ifdef TCP_ACCOUNTING
16594 	uint64_t crtsc;
16595 #endif
16596 #ifdef INET6
16597 	struct ip6_hdr *ip6 = NULL;
16598 	int32_t isipv6;
16599 #endif
16600 	uint8_t filled_all = 0;
16601 	bool hw_tls = false;
16602 
16603 	/* setup and take the cache hits here */
16604 	rack = (struct tcp_rack *)tp->t_fb_ptr;
16605 #ifdef TCP_ACCOUNTING
16606 	sched_pin();
16607 	ts_val = get_cyclecount();
16608 #endif
16609 	hpts_calling = rack->rc_inp->inp_hpts_calls;
16610 	NET_EPOCH_ASSERT();
16611 	INP_WLOCK_ASSERT(rack->rc_inp);
16612 #ifdef TCP_OFFLOAD
16613 	if (tp->t_flags & TF_TOE) {
16614 #ifdef TCP_ACCOUNTING
16615 		sched_unpin();
16616 #endif
16617 		return (tcp_offload_output(tp));
16618 	}
16619 #endif
16620 	/*
16621 	 * For TFO connections in SYN_RECEIVED, only allow the initial
16622 	 * SYN|ACK and those sent by the retransmit timer.
16623 	 */
16624 	if (IS_FASTOPEN(tp->t_flags) &&
16625 	    (tp->t_state == TCPS_SYN_RECEIVED) &&
16626 	    SEQ_GT(tp->snd_max, tp->snd_una) &&    /* initial SYN|ACK sent */
16627 	    (rack->r_ctl.rc_resend == NULL)) {         /* not a retransmit */
16628 #ifdef TCP_ACCOUNTING
16629 		sched_unpin();
16630 #endif
16631 		return (0);
16632 	}
16633 #ifdef INET6
16634 	if (rack->r_state) {
16635 		/* Use the cache line loaded if possible */
16636 		isipv6 = rack->r_is_v6;
16637 	} else {
16638 		isipv6 = (rack->rc_inp->inp_vflag & INP_IPV6) != 0;
16639 	}
16640 #endif
16641 	early = 0;
16642 	cts = tcp_get_usecs(&tv);
16643 	ms_cts = tcp_tv_to_mssectick(&tv);
16644 	if (((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) &&
16645 	    tcp_in_hpts(rack->rc_inp)) {
16646 		/*
16647 		 * We are on the hpts for some timer but not hptsi output.
16648 		 * Remove from the hpts unconditionally.
16649 		 */
16650 		rack_timer_cancel(tp, rack, cts, __LINE__);
16651 	}
16652 	/* Are we pacing and late? */
16653 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
16654 	    TSTMP_GEQ(cts, rack->r_ctl.rc_last_output_to)) {
16655 		/* We are delayed */
16656 		delayed = cts - rack->r_ctl.rc_last_output_to;
16657 	} else {
16658 		delayed = 0;
16659 	}
16660 	/* Do the timers, which may override the pacer */
16661 	if (rack->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
16662 		int retval;
16663 
16664 		retval = rack_process_timers(tp, rack, cts, hpts_calling,
16665 		    &doing_tlp);
16666 		if (retval != 0) {
16667 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_ATIMER], 1);
16668 #ifdef TCP_ACCOUNTING
16669 			sched_unpin();
16670 #endif
16671 			/*
16672 			 * If timers want tcp_drop(), then pass error out,
16673 			 * otherwise suppress it.
16674 			 */
16675 			return (retval < 0 ? retval : 0);
16676 		}
16677 	}
16678 	if (rack->rc_in_persist) {
16679 		if (tcp_in_hpts(rack->rc_inp) == 0) {
16680 			/* Timer is not running */
16681 			rack_start_hpts_timer(rack, tp, cts, 0, 0, 0);
16682 		}
16683 #ifdef TCP_ACCOUNTING
16684 		sched_unpin();
16685 #endif
16686 		return (0);
16687 	}
16688 	if ((rack->r_timer_override) ||
16689 	    (rack->rc_ack_can_sendout_data) ||
16690 	    (delayed) ||
16691 	    (tp->t_state < TCPS_ESTABLISHED)) {
16692 		rack->rc_ack_can_sendout_data = 0;
16693 		if (tcp_in_hpts(rack->rc_inp))
16694 			tcp_hpts_remove(rack->rc_inp);
16695 	} else if (tcp_in_hpts(rack->rc_inp)) {
16696 		/*
16697 		 * On the hpts you can't pass even if ACKNOW is on, we will
16698 		 * when the hpts fires.
16699 		 */
16700 #ifdef TCP_ACCOUNTING
16701 		crtsc = get_cyclecount();
16702 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16703 			tp->tcp_proc_time[SND_BLOCKED] += (crtsc - ts_val);
16704 		}
16705 		counter_u64_add(tcp_proc_time[SND_BLOCKED], (crtsc - ts_val));
16706 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
16707 			tp->tcp_cnt_counters[SND_BLOCKED]++;
16708 		}
16709 		counter_u64_add(tcp_cnt_counters[SND_BLOCKED], 1);
16710 		sched_unpin();
16711 #endif
16712 		counter_u64_add(rack_out_size[TCP_MSS_ACCT_INPACE], 1);
16713 		return (0);
16714 	}
16715 	rack->rc_inp->inp_hpts_calls = 0;
16716 	/* Finish out both pacing early and late accounting */
16717 	if ((rack->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
16718 	    TSTMP_GT(rack->r_ctl.rc_last_output_to, cts)) {
16719 		early = rack->r_ctl.rc_last_output_to - cts;
16720 	} else
16721 		early = 0;
16722 	if (delayed) {
16723 		rack->r_ctl.rc_agg_delayed += delayed;
16724 		rack->r_late = 1;
16725 	} else if (early) {
16726 		rack->r_ctl.rc_agg_early += early;
16727 		rack->r_early = 1;
16728 	}
16729 	/* Now that early/late accounting is done turn off the flag */
16730 	rack->r_ctl.rc_hpts_flags &= ~PACE_PKT_OUTPUT;
16731 	rack->r_wanted_output = 0;
16732 	rack->r_timer_override = 0;
16733 	if ((tp->t_state != rack->r_state) &&
16734 	    TCPS_HAVEESTABLISHED(tp->t_state)) {
16735 		rack_set_state(tp, rack);
16736 	}
16737 	if ((rack->r_fast_output) &&
16738 	    (doing_tlp == 0) &&
16739 	    (tp->rcv_numsacks == 0)) {
16740 		int ret;
16741 
16742 		error = 0;
16743 		ret = rack_fast_output(tp, rack, ts_val, cts, ms_cts, &tv, tot_len_this_send, &error);
16744 		if (ret >= 0)
16745 			return(ret);
16746 		else if (error) {
16747 			inp = rack->rc_inp;
16748 			so = inp->inp_socket;
16749 			sb = &so->so_snd;
16750 			goto nomore;
16751 		}
16752 	}
16753 	inp = rack->rc_inp;
16754 	/*
16755 	 * For TFO connections in SYN_SENT or SYN_RECEIVED,
16756 	 * only allow the initial SYN or SYN|ACK and those sent
16757 	 * by the retransmit timer.
16758 	 */
16759 	if (IS_FASTOPEN(tp->t_flags) &&
16760 	    ((tp->t_state == TCPS_SYN_RECEIVED) ||
16761 	     (tp->t_state == TCPS_SYN_SENT)) &&
16762 	    SEQ_GT(tp->snd_max, tp->snd_una) && /* initial SYN or SYN|ACK sent */
16763 	    (tp->t_rxtshift == 0)) {              /* not a retransmit */
16764 		cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
16765 		so = inp->inp_socket;
16766 		sb = &so->so_snd;
16767 		goto just_return_nolock;
16768 	}
16769 	/*
16770 	 * Determine length of data that should be transmitted, and flags
16771 	 * that will be used. If there is some data or critical controls
16772 	 * (SYN, RST) to send, then transmit; otherwise, investigate
16773 	 * further.
16774 	 */
16775 	idle = (tp->t_flags & TF_LASTIDLE) || (tp->snd_max == tp->snd_una);
16776 	if (tp->t_idle_reduce) {
16777 		if (idle && (TICKS_2_USEC(ticks - tp->t_rcvtime) >= tp->t_rxtcur))
16778 			rack_cc_after_idle(rack, tp);
16779 	}
16780 	tp->t_flags &= ~TF_LASTIDLE;
16781 	if (idle) {
16782 		if (tp->t_flags & TF_MORETOCOME) {
16783 			tp->t_flags |= TF_LASTIDLE;
16784 			idle = 0;
16785 		}
16786 	}
16787 	if ((tp->snd_una == tp->snd_max) &&
16788 	    rack->r_ctl.rc_went_idle_time &&
16789 	    TSTMP_GT(cts, rack->r_ctl.rc_went_idle_time)) {
16790 		idle = cts - rack->r_ctl.rc_went_idle_time;
16791 		if (idle > rack_min_probertt_hold) {
16792 			/* Count as a probe rtt */
16793 			if (rack->in_probe_rtt == 0) {
16794 				rack->r_ctl.rc_lower_rtt_us_cts = cts;
16795 				rack->r_ctl.rc_time_probertt_entered = rack->r_ctl.rc_lower_rtt_us_cts;
16796 				rack->r_ctl.rc_time_probertt_starts = rack->r_ctl.rc_lower_rtt_us_cts;
16797 				rack->r_ctl.rc_time_of_last_probertt = rack->r_ctl.rc_lower_rtt_us_cts;
16798 			} else {
16799 				rack_exit_probertt(rack, cts);
16800 			}
16801 		}
16802 		idle = 0;
16803 	}
16804 	if (rack_use_fsb && (rack->r_fsb_inited == 0) && (rack->r_state != TCPS_CLOSED))
16805 		rack_init_fsb_block(tp, rack);
16806 again:
16807 	/*
16808 	 * If we've recently taken a timeout, snd_max will be greater than
16809 	 * snd_nxt.  There may be SACK information that allows us to avoid
16810 	 * resending already delivered data.  Adjust snd_nxt accordingly.
16811 	 */
16812 	sendalot = 0;
16813 	cts = tcp_get_usecs(&tv);
16814 	ms_cts = tcp_tv_to_mssectick(&tv);
16815 	tso = 0;
16816 	mtu = 0;
16817 	segsiz = min(ctf_fixed_maxseg(tp), rack->r_ctl.rc_pace_min_segs);
16818 	minseg = segsiz;
16819 	if (rack->r_ctl.rc_pace_max_segs == 0)
16820 		pace_max_seg = rack->rc_user_set_max_segs * segsiz;
16821 	else
16822 		pace_max_seg = rack->r_ctl.rc_pace_max_segs;
16823 	sb_offset = tp->snd_max - tp->snd_una;
16824 	cwnd_to_use = rack->r_ctl.cwnd_to_use = tp->snd_cwnd;
16825 	flags = tcp_outflags[tp->t_state];
16826 	while (rack->rc_free_cnt < rack_free_cache) {
16827 		rsm = rack_alloc(rack);
16828 		if (rsm == NULL) {
16829 			if (inp->inp_hpts_calls)
16830 				/* Retry in a ms */
16831 				slot = (1 * HPTS_USEC_IN_MSEC);
16832 			so = inp->inp_socket;
16833 			sb = &so->so_snd;
16834 			goto just_return_nolock;
16835 		}
16836 		TAILQ_INSERT_TAIL(&rack->r_ctl.rc_free, rsm, r_tnext);
16837 		rack->rc_free_cnt++;
16838 		rsm = NULL;
16839 	}
16840 	if (inp->inp_hpts_calls)
16841 		inp->inp_hpts_calls = 0;
16842 	sack_rxmit = 0;
16843 	len = 0;
16844 	rsm = NULL;
16845 	if (flags & TH_RST) {
16846 		SOCKBUF_LOCK(&inp->inp_socket->so_snd);
16847 		so = inp->inp_socket;
16848 		sb = &so->so_snd;
16849 		goto send;
16850 	}
16851 	if (rack->r_ctl.rc_resend) {
16852 		/* Retransmit timer */
16853 		rsm = rack->r_ctl.rc_resend;
16854 		rack->r_ctl.rc_resend = NULL;
16855 		len = rsm->r_end - rsm->r_start;
16856 		sack_rxmit = 1;
16857 		sendalot = 0;
16858 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
16859 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
16860 			 __func__, __LINE__,
16861 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
16862 		sb_offset = rsm->r_start - tp->snd_una;
16863 		if (len >= segsiz)
16864 			len = segsiz;
16865 	} else if ((rsm = tcp_rack_output(tp, rack, cts)) != NULL) {
16866 		/* We have a retransmit that takes precedence */
16867 		if ((!IN_FASTRECOVERY(tp->t_flags)) &&
16868 		    ((rsm->r_flags & RACK_MUST_RXT) == 0) &&
16869 		    ((tp->t_flags & TF_WASFRECOVERY) == 0)) {
16870 			/* Enter recovery if not induced by a time-out */
16871 			rack_cong_signal(tp, CC_NDUPACK, tp->snd_una, __LINE__);
16872 		}
16873 #ifdef INVARIANTS
16874 		if (SEQ_LT(rsm->r_start, tp->snd_una)) {
16875 			panic("Huh, tp:%p rack:%p rsm:%p start:%u < snd_una:%u\n",
16876 			      tp, rack, rsm, rsm->r_start, tp->snd_una);
16877 		}
16878 #endif
16879 		len = rsm->r_end - rsm->r_start;
16880 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
16881 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
16882 			 __func__, __LINE__,
16883 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
16884 		sb_offset = rsm->r_start - tp->snd_una;
16885 		sendalot = 0;
16886 		if (len >= segsiz)
16887 			len = segsiz;
16888 		if (len > 0) {
16889 			sack_rxmit = 1;
16890 			KMOD_TCPSTAT_INC(tcps_sack_rexmits);
16891 			KMOD_TCPSTAT_ADD(tcps_sack_rexmit_bytes,
16892 			    min(len, segsiz));
16893 		}
16894 	} else if (rack->r_ctl.rc_tlpsend) {
16895 		/* Tail loss probe */
16896 		long cwin;
16897 		long tlen;
16898 
16899 		/*
16900 		 * Check if we can do a TLP with a RACK'd packet
16901 		 * this can happen if we are not doing the rack
16902 		 * cheat and we skipped to a TLP and it
16903 		 * went off.
16904 		 */
16905 		rsm = rack->r_ctl.rc_tlpsend;
16906 		/* We are doing a TLP make sure the flag is preent */
16907 		rsm->r_flags |= RACK_TLP;
16908 		rack->r_ctl.rc_tlpsend = NULL;
16909 		sack_rxmit = 1;
16910 		tlen = rsm->r_end - rsm->r_start;
16911 		if (tlen > segsiz)
16912 			tlen = segsiz;
16913 		KASSERT(SEQ_LEQ(tp->snd_una, rsm->r_start),
16914 			("%s:%d: r.start:%u < SND.UNA:%u; tp:%p, rack:%p, rsm:%p",
16915 			 __func__, __LINE__,
16916 			 rsm->r_start, tp->snd_una, tp, rack, rsm));
16917 		sb_offset = rsm->r_start - tp->snd_una;
16918 		cwin = min(tp->snd_wnd, tlen);
16919 		len = cwin;
16920 	}
16921 	if (rack->r_must_retran &&
16922 	    (doing_tlp == 0) &&
16923 	    (rsm == NULL)) {
16924 		/*
16925 		 * Non-Sack and we had a RTO or Sack/non-Sack and a
16926 		 * MTU change, we need to retransmit until we reach
16927 		 * the former snd_max (rack->r_ctl.rc_snd_max_at_rto).
16928 		 */
16929 		if (SEQ_GT(tp->snd_max, tp->snd_una)) {
16930 			int sendwin, flight;
16931 
16932 			sendwin = min(tp->snd_wnd, tp->snd_cwnd);
16933 			flight = ctf_flight_size(tp, rack->r_ctl.rc_out_at_rto);
16934 			if (flight >= sendwin) {
16935 				so = inp->inp_socket;
16936 				sb = &so->so_snd;
16937 				goto just_return_nolock;
16938 			}
16939 			rsm = TAILQ_FIRST(&rack->r_ctl.rc_tmap);
16940 			if (rsm == NULL) {
16941 				/* TSNH */
16942 				rack->r_must_retran = 0;
16943 				rack->r_ctl.rc_out_at_rto = 0;
16944 				so = inp->inp_socket;
16945 				sb = &so->so_snd;
16946 				goto just_return_nolock;
16947 			}
16948 			if ((rsm->r_flags & RACK_MUST_RXT) == 0) {
16949 				/* It does not have the flag, we are done */
16950 				rack->r_must_retran = 0;
16951 				rack->r_ctl.rc_out_at_rto = 0;
16952 			} else {
16953 				sack_rxmit = 1;
16954 				len = rsm->r_end - rsm->r_start;
16955 				sendalot = 0;
16956 				sb_offset = rsm->r_start - tp->snd_una;
16957 				if (len >= segsiz)
16958 					len = segsiz;
16959 				/*
16960 				 * Delay removing the flag RACK_MUST_RXT so
16961 				 * that the fastpath for retransmit will
16962 				 * work with this rsm.
16963 				 */
16964 
16965 			}
16966 		} else {
16967 			/* We must be done if there is nothing outstanding */
16968 			rack->r_must_retran = 0;
16969 			rack->r_ctl.rc_out_at_rto = 0;
16970 		}
16971 	}
16972 	/*
16973 	 * Enforce a connection sendmap count limit if set
16974 	 * as long as we are not retransmiting.
16975 	 */
16976 	if ((rsm == NULL) &&
16977 	    (rack->do_detection == 0) &&
16978 	    (V_tcp_map_entries_limit > 0) &&
16979 	    (rack->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
16980 		counter_u64_add(rack_to_alloc_limited, 1);
16981 		if (!rack->alloc_limit_reported) {
16982 			rack->alloc_limit_reported = 1;
16983 			counter_u64_add(rack_alloc_limited_conns, 1);
16984 		}
16985 		so = inp->inp_socket;
16986 		sb = &so->so_snd;
16987 		goto just_return_nolock;
16988 	}
16989 	if (rsm && (rsm->r_flags & RACK_HAS_FIN)) {
16990 		/* we are retransmitting the fin */
16991 		len--;
16992 		if (len) {
16993 			/*
16994 			 * When retransmitting data do *not* include the
16995 			 * FIN. This could happen from a TLP probe.
16996 			 */
16997 			flags &= ~TH_FIN;
16998 		}
16999 	}
17000 	if (rsm && rack->r_fsb_inited && rack_use_rsm_rfo &&
17001 	    ((rsm->r_flags & RACK_HAS_FIN) == 0)) {
17002 		int ret;
17003 
17004 		ret = rack_fast_rsm_output(tp, rack, rsm, ts_val, cts, ms_cts, &tv, len, doing_tlp);
17005 		if (ret == 0)
17006 			return (0);
17007 	}
17008 	so = inp->inp_socket;
17009 	sb = &so->so_snd;
17010 	if (do_a_prefetch == 0) {
17011 		kern_prefetch(sb, &do_a_prefetch);
17012 		do_a_prefetch = 1;
17013 	}
17014 #ifdef NETFLIX_SHARED_CWND
17015 	if ((tp->t_flags2 & TF2_TCP_SCWND_ALLOWED) &&
17016 	    rack->rack_enable_scwnd) {
17017 		/* We are doing cwnd sharing */
17018 		if (rack->gp_ready &&
17019 		    (rack->rack_attempted_scwnd == 0) &&
17020 		    (rack->r_ctl.rc_scw == NULL) &&
17021 		    tp->t_lib) {
17022 			/* The pcbid is in, lets make an attempt */
17023 			counter_u64_add(rack_try_scwnd, 1);
17024 			rack->rack_attempted_scwnd = 1;
17025 			rack->r_ctl.rc_scw = tcp_shared_cwnd_alloc(tp,
17026 								   &rack->r_ctl.rc_scw_index,
17027 								   segsiz);
17028 		}
17029 		if (rack->r_ctl.rc_scw &&
17030 		    (rack->rack_scwnd_is_idle == 1) &&
17031 		    sbavail(&so->so_snd)) {
17032 			/* we are no longer out of data */
17033 			tcp_shared_cwnd_active(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
17034 			rack->rack_scwnd_is_idle = 0;
17035 		}
17036 		if (rack->r_ctl.rc_scw) {
17037 			/* First lets update and get the cwnd */
17038 			rack->r_ctl.cwnd_to_use = cwnd_to_use = tcp_shared_cwnd_update(rack->r_ctl.rc_scw,
17039 								    rack->r_ctl.rc_scw_index,
17040 								    tp->snd_cwnd, tp->snd_wnd, segsiz);
17041 		}
17042 	}
17043 #endif
17044 	/*
17045 	 * Get standard flags, and add SYN or FIN if requested by 'hidden'
17046 	 * state flags.
17047 	 */
17048 	if (tp->t_flags & TF_NEEDFIN)
17049 		flags |= TH_FIN;
17050 	if (tp->t_flags & TF_NEEDSYN)
17051 		flags |= TH_SYN;
17052 	if ((sack_rxmit == 0) && (prefetch_rsm == 0)) {
17053 		void *end_rsm;
17054 		end_rsm = TAILQ_LAST_FAST(&rack->r_ctl.rc_tmap, rack_sendmap, r_tnext);
17055 		if (end_rsm)
17056 			kern_prefetch(end_rsm, &prefetch_rsm);
17057 		prefetch_rsm = 1;
17058 	}
17059 	SOCKBUF_LOCK(sb);
17060 	/*
17061 	 * If snd_nxt == snd_max and we have transmitted a FIN, the
17062 	 * sb_offset will be > 0 even if so_snd.sb_cc is 0, resulting in a
17063 	 * negative length.  This can also occur when TCP opens up its
17064 	 * congestion window while receiving additional duplicate acks after
17065 	 * fast-retransmit because TCP will reset snd_nxt to snd_max after
17066 	 * the fast-retransmit.
17067 	 *
17068 	 * In the normal retransmit-FIN-only case, however, snd_nxt will be
17069 	 * set to snd_una, the sb_offset will be 0, and the length may wind
17070 	 * up 0.
17071 	 *
17072 	 * If sack_rxmit is true we are retransmitting from the scoreboard
17073 	 * in which case len is already set.
17074 	 */
17075 	if ((sack_rxmit == 0) &&
17076 	    (TCPS_HAVEESTABLISHED(tp->t_state) || IS_FASTOPEN(tp->t_flags))) {
17077 		uint32_t avail;
17078 
17079 		avail = sbavail(sb);
17080 		if (SEQ_GT(tp->snd_nxt, tp->snd_una) && avail)
17081 			sb_offset = tp->snd_nxt - tp->snd_una;
17082 		else
17083 			sb_offset = 0;
17084 		if ((IN_FASTRECOVERY(tp->t_flags) == 0) || rack->rack_no_prr) {
17085 			if (rack->r_ctl.rc_tlp_new_data) {
17086 				/* TLP is forcing out new data */
17087 				if (rack->r_ctl.rc_tlp_new_data > (uint32_t) (avail - sb_offset)) {
17088 					rack->r_ctl.rc_tlp_new_data = (uint32_t) (avail - sb_offset);
17089 				}
17090 				if ((rack->r_ctl.rc_tlp_new_data + sb_offset) > tp->snd_wnd) {
17091 					if (tp->snd_wnd > sb_offset)
17092 						len = tp->snd_wnd - sb_offset;
17093 					else
17094 						len = 0;
17095 				} else {
17096 					len = rack->r_ctl.rc_tlp_new_data;
17097 				}
17098 				rack->r_ctl.rc_tlp_new_data = 0;
17099 			}  else {
17100 				len = rack_what_can_we_send(tp, rack, cwnd_to_use, avail, sb_offset);
17101 			}
17102 			if ((rack->r_ctl.crte == NULL) && IN_FASTRECOVERY(tp->t_flags) && (len > segsiz)) {
17103 				/*
17104 				 * For prr=off, we need to send only 1 MSS
17105 				 * at a time. We do this because another sack could
17106 				 * be arriving that causes us to send retransmits and
17107 				 * we don't want to be on a long pace due to a larger send
17108 				 * that keeps us from sending out the retransmit.
17109 				 */
17110 				len = segsiz;
17111 			}
17112 		} else {
17113 			uint32_t outstanding;
17114 			/*
17115 			 * We are inside of a Fast recovery episode, this
17116 			 * is caused by a SACK or 3 dup acks. At this point
17117 			 * we have sent all the retransmissions and we rely
17118 			 * on PRR to dictate what we will send in the form of
17119 			 * new data.
17120 			 */
17121 
17122 			outstanding = tp->snd_max - tp->snd_una;
17123 			if ((rack->r_ctl.rc_prr_sndcnt + outstanding) > tp->snd_wnd) {
17124 				if (tp->snd_wnd > outstanding) {
17125 					len = tp->snd_wnd - outstanding;
17126 					/* Check to see if we have the data */
17127 					if ((sb_offset + len) > avail) {
17128 						/* It does not all fit */
17129 						if (avail > sb_offset)
17130 							len = avail - sb_offset;
17131 						else
17132 							len = 0;
17133 					}
17134 				} else {
17135 					len = 0;
17136 				}
17137 			} else if (avail > sb_offset) {
17138 				len = avail - sb_offset;
17139 			} else {
17140 				len = 0;
17141 			}
17142 			if (len > 0) {
17143 				if (len > rack->r_ctl.rc_prr_sndcnt) {
17144 					len = rack->r_ctl.rc_prr_sndcnt;
17145 				}
17146 				if (len > 0) {
17147 					sub_from_prr = 1;
17148 				}
17149 			}
17150 			if (len > segsiz) {
17151 				/*
17152 				 * We should never send more than a MSS when
17153 				 * retransmitting or sending new data in prr
17154 				 * mode unless the override flag is on. Most
17155 				 * likely the PRR algorithm is not going to
17156 				 * let us send a lot as well :-)
17157 				 */
17158 				if (rack->r_ctl.rc_prr_sendalot == 0) {
17159 					len = segsiz;
17160 				}
17161 			} else if (len < segsiz) {
17162 				/*
17163 				 * Do we send any? The idea here is if the
17164 				 * send empty's the socket buffer we want to
17165 				 * do it. However if not then lets just wait
17166 				 * for our prr_sndcnt to get bigger.
17167 				 */
17168 				long leftinsb;
17169 
17170 				leftinsb = sbavail(sb) - sb_offset;
17171 				if (leftinsb > len) {
17172 					/* This send does not empty the sb */
17173 					len = 0;
17174 				}
17175 			}
17176 		}
17177 	} else if (!TCPS_HAVEESTABLISHED(tp->t_state)) {
17178 		/*
17179 		 * If you have not established
17180 		 * and are not doing FAST OPEN
17181 		 * no data please.
17182 		 */
17183 		if ((sack_rxmit == 0) &&
17184 		    (!IS_FASTOPEN(tp->t_flags))){
17185 			len = 0;
17186 			sb_offset = 0;
17187 		}
17188 	}
17189 	if (prefetch_so_done == 0) {
17190 		kern_prefetch(so, &prefetch_so_done);
17191 		prefetch_so_done = 1;
17192 	}
17193 	/*
17194 	 * Lop off SYN bit if it has already been sent.  However, if this is
17195 	 * SYN-SENT state and if segment contains data and if we don't know
17196 	 * that foreign host supports TAO, suppress sending segment.
17197 	 */
17198 	if ((flags & TH_SYN) && SEQ_GT(tp->snd_nxt, tp->snd_una) &&
17199 	    ((sack_rxmit == 0) && (tp->t_rxtshift == 0))) {
17200 		/*
17201 		 * When sending additional segments following a TFO SYN|ACK,
17202 		 * do not include the SYN bit.
17203 		 */
17204 		if (IS_FASTOPEN(tp->t_flags) &&
17205 		    (tp->t_state == TCPS_SYN_RECEIVED))
17206 			flags &= ~TH_SYN;
17207 	}
17208 	/*
17209 	 * Be careful not to send data and/or FIN on SYN segments. This
17210 	 * measure is needed to prevent interoperability problems with not
17211 	 * fully conformant TCP implementations.
17212 	 */
17213 	if ((flags & TH_SYN) && (tp->t_flags & TF_NOOPT)) {
17214 		len = 0;
17215 		flags &= ~TH_FIN;
17216 	}
17217 	/*
17218 	 * On TFO sockets, ensure no data is sent in the following cases:
17219 	 *
17220 	 *  - When retransmitting SYN|ACK on a passively-created socket
17221 	 *
17222 	 *  - When retransmitting SYN on an actively created socket
17223 	 *
17224 	 *  - When sending a zero-length cookie (cookie request) on an
17225 	 *    actively created socket
17226 	 *
17227 	 *  - When the socket is in the CLOSED state (RST is being sent)
17228 	 */
17229 	if (IS_FASTOPEN(tp->t_flags) &&
17230 	    (((flags & TH_SYN) && (tp->t_rxtshift > 0)) ||
17231 	     ((tp->t_state == TCPS_SYN_SENT) &&
17232 	      (tp->t_tfo_client_cookie_len == 0)) ||
17233 	     (flags & TH_RST))) {
17234 		sack_rxmit = 0;
17235 		len = 0;
17236 	}
17237 	/* Without fast-open there should never be data sent on a SYN */
17238 	if ((flags & TH_SYN) && (!IS_FASTOPEN(tp->t_flags))) {
17239 		tp->snd_nxt = tp->iss;
17240 		len = 0;
17241 	}
17242 	if ((len > segsiz) && (tcp_dsack_block_exists(tp))) {
17243 		/* We only send 1 MSS if we have a DSACK block */
17244 		add_flag |= RACK_SENT_W_DSACK;
17245 		len = segsiz;
17246 	}
17247 	orig_len = len;
17248 	if (len <= 0) {
17249 		/*
17250 		 * If FIN has been sent but not acked, but we haven't been
17251 		 * called to retransmit, len will be < 0.  Otherwise, window
17252 		 * shrank after we sent into it.  If window shrank to 0,
17253 		 * cancel pending retransmit, pull snd_nxt back to (closed)
17254 		 * window, and set the persist timer if it isn't already
17255 		 * going.  If the window didn't close completely, just wait
17256 		 * for an ACK.
17257 		 *
17258 		 * We also do a general check here to ensure that we will
17259 		 * set the persist timer when we have data to send, but a
17260 		 * 0-byte window. This makes sure the persist timer is set
17261 		 * even if the packet hits one of the "goto send" lines
17262 		 * below.
17263 		 */
17264 		len = 0;
17265 		if ((tp->snd_wnd == 0) &&
17266 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
17267 		    (tp->snd_una == tp->snd_max) &&
17268 		    (sb_offset < (int)sbavail(sb))) {
17269 			rack_enter_persist(tp, rack, cts);
17270 		}
17271 	} else if ((rsm == NULL) &&
17272 		   (doing_tlp == 0) &&
17273 		   (len < pace_max_seg)) {
17274 		/*
17275 		 * We are not sending a maximum sized segment for
17276 		 * some reason. Should we not send anything (think
17277 		 * sws or persists)?
17278 		 */
17279 		if ((tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
17280 		    (TCPS_HAVEESTABLISHED(tp->t_state)) &&
17281 		    (len < minseg) &&
17282 		    (len < (int)(sbavail(sb) - sb_offset))) {
17283 			/*
17284 			 * Here the rwnd is less than
17285 			 * the minimum pacing size, this is not a retransmit,
17286 			 * we are established and
17287 			 * the send is not the last in the socket buffer
17288 			 * we send nothing, and we may enter persists
17289 			 * if nothing is outstanding.
17290 			 */
17291 			len = 0;
17292 			if (tp->snd_max == tp->snd_una) {
17293 				/*
17294 				 * Nothing out we can
17295 				 * go into persists.
17296 				 */
17297 				rack_enter_persist(tp, rack, cts);
17298 			}
17299 		     } else if ((cwnd_to_use >= max(minseg, (segsiz * 4))) &&
17300 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
17301 			   (len < (int)(sbavail(sb) - sb_offset)) &&
17302 			   (len < minseg)) {
17303 			/*
17304 			 * Here we are not retransmitting, and
17305 			 * the cwnd is not so small that we could
17306 			 * not send at least a min size (rxt timer
17307 			 * not having gone off), We have 2 segments or
17308 			 * more already in flight, its not the tail end
17309 			 * of the socket buffer  and the cwnd is blocking
17310 			 * us from sending out a minimum pacing segment size.
17311 			 * Lets not send anything.
17312 			 */
17313 			len = 0;
17314 		} else if (((tp->snd_wnd - ctf_outstanding(tp)) <
17315 			    min((rack->r_ctl.rc_high_rwnd/2), minseg)) &&
17316 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) > (2 * segsiz)) &&
17317 			   (len < (int)(sbavail(sb) - sb_offset)) &&
17318 			   (TCPS_HAVEESTABLISHED(tp->t_state))) {
17319 			/*
17320 			 * Here we have a send window but we have
17321 			 * filled it up and we can't send another pacing segment.
17322 			 * We also have in flight more than 2 segments
17323 			 * and we are not completing the sb i.e. we allow
17324 			 * the last bytes of the sb to go out even if
17325 			 * its not a full pacing segment.
17326 			 */
17327 			len = 0;
17328 		} else if ((rack->r_ctl.crte != NULL) &&
17329 			   (tp->snd_wnd >= (pace_max_seg * max(1, rack_hw_rwnd_factor))) &&
17330 			   (cwnd_to_use >= (pace_max_seg + (4 * segsiz))) &&
17331 			   (ctf_flight_size(tp, rack->r_ctl.rc_sacked) >= (2 * segsiz)) &&
17332 			   (len < (int)(sbavail(sb) - sb_offset))) {
17333 			/*
17334 			 * Here we are doing hardware pacing, this is not a TLP,
17335 			 * we are not sending a pace max segment size, there is rwnd
17336 			 * room to send at least N pace_max_seg, the cwnd is greater
17337 			 * than or equal to a full pacing segments plus 4 mss and we have 2 or
17338 			 * more segments in flight and its not the tail of the socket buffer.
17339 			 *
17340 			 * We don't want to send instead we need to get more ack's in to
17341 			 * allow us to send a full pacing segment. Normally, if we are pacing
17342 			 * about the right speed, we should have finished our pacing
17343 			 * send as most of the acks have come back if we are at the
17344 			 * right rate. This is a bit fuzzy since return path delay
17345 			 * can delay the acks, which is why we want to make sure we
17346 			 * have cwnd space to have a bit more than a max pace segments in flight.
17347 			 *
17348 			 * If we have not gotten our acks back we are pacing at too high a
17349 			 * rate delaying will not hurt and will bring our GP estimate down by
17350 			 * injecting the delay. If we don't do this we will send
17351 			 * 2 MSS out in response to the acks being clocked in which
17352 			 * defeats the point of hw-pacing (i.e. to help us get
17353 			 * larger TSO's out).
17354 			 */
17355 			len = 0;
17356 
17357 		}
17358 
17359 	}
17360 	/* len will be >= 0 after this point. */
17361 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
17362 	rack_sndbuf_autoscale(rack);
17363 	/*
17364 	 * Decide if we can use TCP Segmentation Offloading (if supported by
17365 	 * hardware).
17366 	 *
17367 	 * TSO may only be used if we are in a pure bulk sending state.  The
17368 	 * presence of TCP-MD5, SACK retransmits, SACK advertizements and IP
17369 	 * options prevent using TSO.  With TSO the TCP header is the same
17370 	 * (except for the sequence number) for all generated packets.  This
17371 	 * makes it impossible to transmit any options which vary per
17372 	 * generated segment or packet.
17373 	 *
17374 	 * IPv4 handling has a clear separation of ip options and ip header
17375 	 * flags while IPv6 combines both in in6p_outputopts. ip6_optlen() does
17376 	 * the right thing below to provide length of just ip options and thus
17377 	 * checking for ipoptlen is enough to decide if ip options are present.
17378 	 */
17379 	ipoptlen = 0;
17380 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
17381 	/*
17382 	 * Pre-calculate here as we save another lookup into the darknesses
17383 	 * of IPsec that way and can actually decide if TSO is ok.
17384 	 */
17385 #ifdef INET6
17386 	if (isipv6 && IPSEC_ENABLED(ipv6))
17387 		ipsec_optlen = IPSEC_HDRSIZE(ipv6, tp->t_inpcb);
17388 #ifdef INET
17389 	else
17390 #endif
17391 #endif				/* INET6 */
17392 #ifdef INET
17393 		if (IPSEC_ENABLED(ipv4))
17394 			ipsec_optlen = IPSEC_HDRSIZE(ipv4, tp->t_inpcb);
17395 #endif				/* INET */
17396 #endif
17397 
17398 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
17399 	ipoptlen += ipsec_optlen;
17400 #endif
17401 	if ((tp->t_flags & TF_TSO) && V_tcp_do_tso && len > segsiz &&
17402 	    (tp->t_port == 0) &&
17403 	    ((tp->t_flags & TF_SIGNATURE) == 0) &&
17404 	    tp->rcv_numsacks == 0 && sack_rxmit == 0 &&
17405 	    ipoptlen == 0)
17406 		tso = 1;
17407 	{
17408 		uint32_t outstanding;
17409 
17410 		outstanding = tp->snd_max - tp->snd_una;
17411 		if (tp->t_flags & TF_SENTFIN) {
17412 			/*
17413 			 * If we sent a fin, snd_max is 1 higher than
17414 			 * snd_una
17415 			 */
17416 			outstanding--;
17417 		}
17418 		if (sack_rxmit) {
17419 			if ((rsm->r_flags & RACK_HAS_FIN) == 0)
17420 				flags &= ~TH_FIN;
17421 		} else {
17422 			if (SEQ_LT(tp->snd_nxt + len, tp->snd_una +
17423 				   sbused(sb)))
17424 				flags &= ~TH_FIN;
17425 		}
17426 	}
17427 	recwin = lmin(lmax(sbspace(&so->so_rcv), 0),
17428 	    (long)TCP_MAXWIN << tp->rcv_scale);
17429 
17430 	/*
17431 	 * Sender silly window avoidance.   We transmit under the following
17432 	 * conditions when len is non-zero:
17433 	 *
17434 	 * - We have a full segment (or more with TSO) - This is the last
17435 	 * buffer in a write()/send() and we are either idle or running
17436 	 * NODELAY - we've timed out (e.g. persist timer) - we have more
17437 	 * then 1/2 the maximum send window's worth of data (receiver may be
17438 	 * limited the window size) - we need to retransmit
17439 	 */
17440 	if (len) {
17441 		if (len >= segsiz) {
17442 			goto send;
17443 		}
17444 		/*
17445 		 * NOTE! on localhost connections an 'ack' from the remote
17446 		 * end may occur synchronously with the output and cause us
17447 		 * to flush a buffer queued with moretocome.  XXX
17448 		 *
17449 		 */
17450 		if (!(tp->t_flags & TF_MORETOCOME) &&	/* normal case */
17451 		    (idle || (tp->t_flags & TF_NODELAY)) &&
17452 		    ((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
17453 		    (tp->t_flags & TF_NOPUSH) == 0) {
17454 			pass = 2;
17455 			goto send;
17456 		}
17457 		if ((tp->snd_una == tp->snd_max) && len) {	/* Nothing outstanding */
17458 			pass = 22;
17459 			goto send;
17460 		}
17461 		if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0) {
17462 			pass = 4;
17463 			goto send;
17464 		}
17465 		if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {	/* retransmit case */
17466 			pass = 5;
17467 			goto send;
17468 		}
17469 		if (sack_rxmit) {
17470 			pass = 6;
17471 			goto send;
17472 		}
17473 		if (((tp->snd_wnd - ctf_outstanding(tp)) < segsiz) &&
17474 		    (ctf_outstanding(tp) < (segsiz * 2))) {
17475 			/*
17476 			 * We have less than two MSS outstanding (delayed ack)
17477 			 * and our rwnd will not let us send a full sized
17478 			 * MSS. Lets go ahead and let this small segment
17479 			 * out because we want to try to have at least two
17480 			 * packets inflight to not be caught by delayed ack.
17481 			 */
17482 			pass = 12;
17483 			goto send;
17484 		}
17485 	}
17486 	/*
17487 	 * Sending of standalone window updates.
17488 	 *
17489 	 * Window updates are important when we close our window due to a
17490 	 * full socket buffer and are opening it again after the application
17491 	 * reads data from it.  Once the window has opened again and the
17492 	 * remote end starts to send again the ACK clock takes over and
17493 	 * provides the most current window information.
17494 	 *
17495 	 * We must avoid the silly window syndrome whereas every read from
17496 	 * the receive buffer, no matter how small, causes a window update
17497 	 * to be sent.  We also should avoid sending a flurry of window
17498 	 * updates when the socket buffer had queued a lot of data and the
17499 	 * application is doing small reads.
17500 	 *
17501 	 * Prevent a flurry of pointless window updates by only sending an
17502 	 * update when we can increase the advertized window by more than
17503 	 * 1/4th of the socket buffer capacity.  When the buffer is getting
17504 	 * full or is very small be more aggressive and send an update
17505 	 * whenever we can increase by two mss sized segments. In all other
17506 	 * situations the ACK's to new incoming data will carry further
17507 	 * window increases.
17508 	 *
17509 	 * Don't send an independent window update if a delayed ACK is
17510 	 * pending (it will get piggy-backed on it) or the remote side
17511 	 * already has done a half-close and won't send more data.  Skip
17512 	 * this if the connection is in T/TCP half-open state.
17513 	 */
17514 	if (recwin > 0 && !(tp->t_flags & TF_NEEDSYN) &&
17515 	    !(tp->t_flags & TF_DELACK) &&
17516 	    !TCPS_HAVERCVDFIN(tp->t_state)) {
17517 		/*
17518 		 * "adv" is the amount we could increase the window, taking
17519 		 * into account that we are limited by TCP_MAXWIN <<
17520 		 * tp->rcv_scale.
17521 		 */
17522 		int32_t adv;
17523 		int oldwin;
17524 
17525 		adv = recwin;
17526 		if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt)) {
17527 			oldwin = (tp->rcv_adv - tp->rcv_nxt);
17528 			if (adv > oldwin)
17529 			    adv -= oldwin;
17530 			else {
17531 				/* We can't increase the window */
17532 				adv = 0;
17533 			}
17534 		} else
17535 			oldwin = 0;
17536 
17537 		/*
17538 		 * If the new window size ends up being the same as or less
17539 		 * than the old size when it is scaled, then don't force
17540 		 * a window update.
17541 		 */
17542 		if (oldwin >> tp->rcv_scale >= (adv + oldwin) >> tp->rcv_scale)
17543 			goto dontupdate;
17544 
17545 		if (adv >= (int32_t)(2 * segsiz) &&
17546 		    (adv >= (int32_t)(so->so_rcv.sb_hiwat / 4) ||
17547 		     recwin <= (int32_t)(so->so_rcv.sb_hiwat / 8) ||
17548 		     so->so_rcv.sb_hiwat <= 8 * segsiz)) {
17549 			pass = 7;
17550 			goto send;
17551 		}
17552 		if (2 * adv >= (int32_t) so->so_rcv.sb_hiwat) {
17553 			pass = 23;
17554 			goto send;
17555 		}
17556 	}
17557 dontupdate:
17558 
17559 	/*
17560 	 * Send if we owe the peer an ACK, RST, SYN, or urgent data.  ACKNOW
17561 	 * is also a catch-all for the retransmit timer timeout case.
17562 	 */
17563 	if (tp->t_flags & TF_ACKNOW) {
17564 		pass = 8;
17565 		goto send;
17566 	}
17567 	if (((flags & TH_SYN) && (tp->t_flags & TF_NEEDSYN) == 0)) {
17568 		pass = 9;
17569 		goto send;
17570 	}
17571 	/*
17572 	 * If our state indicates that FIN should be sent and we have not
17573 	 * yet done so, then we need to send.
17574 	 */
17575 	if ((flags & TH_FIN) &&
17576 	    (tp->snd_nxt == tp->snd_una)) {
17577 		pass = 11;
17578 		goto send;
17579 	}
17580 	/*
17581 	 * No reason to send a segment, just return.
17582 	 */
17583 just_return:
17584 	SOCKBUF_UNLOCK(sb);
17585 just_return_nolock:
17586 	{
17587 		int app_limited = CTF_JR_SENT_DATA;
17588 
17589 		if (tot_len_this_send > 0) {
17590 			/* Make sure snd_nxt is up to max */
17591 			rack->r_ctl.fsb.recwin = recwin;
17592 			slot = rack_get_pacing_delay(rack, tp, tot_len_this_send, NULL, segsiz);
17593 			if ((error == 0) &&
17594 			    rack_use_rfo &&
17595 			    ((flags & (TH_SYN|TH_FIN)) == 0) &&
17596 			    (ipoptlen == 0) &&
17597 			    (tp->snd_nxt == tp->snd_max) &&
17598 			    (tp->rcv_numsacks == 0) &&
17599 			    rack->r_fsb_inited &&
17600 			    TCPS_HAVEESTABLISHED(tp->t_state) &&
17601 			    (rack->r_must_retran == 0) &&
17602 			    ((tp->t_flags & TF_NEEDFIN) == 0) &&
17603 			    (len > 0) && (orig_len > 0) &&
17604 			    (orig_len > len) &&
17605 			    ((orig_len - len) >= segsiz) &&
17606 			    ((optlen == 0) ||
17607 			     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
17608 				/* We can send at least one more MSS using our fsb */
17609 
17610 				rack->r_fast_output = 1;
17611 				rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
17612 				rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
17613 				rack->r_ctl.fsb.tcp_flags = flags;
17614 				rack->r_ctl.fsb.left_to_send = orig_len - len;
17615 				if (hw_tls)
17616 					rack->r_ctl.fsb.hw_tls = 1;
17617 				else
17618 					rack->r_ctl.fsb.hw_tls = 0;
17619 				KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
17620 					("rack:%p left_to_send:%u sbavail:%u out:%u",
17621 					rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
17622 					 (tp->snd_max - tp->snd_una)));
17623 				if (rack->r_ctl.fsb.left_to_send < segsiz)
17624 					rack->r_fast_output = 0;
17625 				else {
17626 					if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
17627 						rack->r_ctl.fsb.rfo_apply_push = 1;
17628 					else
17629 						rack->r_ctl.fsb.rfo_apply_push = 0;
17630 				}
17631 			} else
17632 				rack->r_fast_output = 0;
17633 
17634 
17635 			rack_log_fsb(rack, tp, so, flags,
17636 				     ipoptlen, orig_len, len, 0,
17637 				     1, optlen, __LINE__, 1);
17638 			if (SEQ_GT(tp->snd_max, tp->snd_nxt))
17639 				tp->snd_nxt = tp->snd_max;
17640 		} else {
17641 			int end_window = 0;
17642 			uint32_t seq = tp->gput_ack;
17643 
17644 			rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
17645 			if (rsm) {
17646 				/*
17647 				 * Mark the last sent that we just-returned (hinting
17648 				 * that delayed ack may play a role in any rtt measurement).
17649 				 */
17650 				rsm->r_just_ret = 1;
17651 			}
17652 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_JUSTRET], 1);
17653 			rack->r_ctl.rc_agg_delayed = 0;
17654 			rack->r_early = 0;
17655 			rack->r_late = 0;
17656 			rack->r_ctl.rc_agg_early = 0;
17657 			if ((ctf_outstanding(tp) +
17658 			     min(max(segsiz, (rack->r_ctl.rc_high_rwnd/2)),
17659 				 minseg)) >= tp->snd_wnd) {
17660 				/* We are limited by the rwnd */
17661 				app_limited = CTF_JR_RWND_LIMITED;
17662 				if (IN_FASTRECOVERY(tp->t_flags))
17663 				    rack->r_ctl.rc_prr_sndcnt = 0;
17664 			} else if (ctf_outstanding(tp) >= sbavail(sb)) {
17665 				/* We are limited by whats available -- app limited */
17666 				app_limited = CTF_JR_APP_LIMITED;
17667 				if (IN_FASTRECOVERY(tp->t_flags))
17668 				    rack->r_ctl.rc_prr_sndcnt = 0;
17669 			} else if ((idle == 0) &&
17670 				   ((tp->t_flags & TF_NODELAY) == 0) &&
17671 				   ((uint32_t)len + (uint32_t)sb_offset >= sbavail(sb)) &&
17672 				   (len < segsiz)) {
17673 				/*
17674 				 * No delay is not on and the
17675 				 * user is sending less than 1MSS. This
17676 				 * brings out SWS avoidance so we
17677 				 * don't send. Another app-limited case.
17678 				 */
17679 				app_limited = CTF_JR_APP_LIMITED;
17680 			} else if (tp->t_flags & TF_NOPUSH) {
17681 				/*
17682 				 * The user has requested no push of
17683 				 * the last segment and we are
17684 				 * at the last segment. Another app
17685 				 * limited case.
17686 				 */
17687 				app_limited = CTF_JR_APP_LIMITED;
17688 			} else if ((ctf_outstanding(tp) + minseg) > cwnd_to_use) {
17689 				/* Its the cwnd */
17690 				app_limited = CTF_JR_CWND_LIMITED;
17691 			} else if (IN_FASTRECOVERY(tp->t_flags) &&
17692 				   (rack->rack_no_prr == 0) &&
17693 				   (rack->r_ctl.rc_prr_sndcnt < segsiz)) {
17694 				app_limited = CTF_JR_PRR;
17695 			} else {
17696 				/* Now why here are we not sending? */
17697 #ifdef NOW
17698 #ifdef INVARIANTS
17699 				panic("rack:%p hit JR_ASSESSING case cwnd_to_use:%u?", rack, cwnd_to_use);
17700 #endif
17701 #endif
17702 				app_limited = CTF_JR_ASSESSING;
17703 			}
17704 			/*
17705 			 * App limited in some fashion, for our pacing GP
17706 			 * measurements we don't want any gap (even cwnd).
17707 			 * Close  down the measurement window.
17708 			 */
17709 			if (rack_cwnd_block_ends_measure &&
17710 			    ((app_limited == CTF_JR_CWND_LIMITED) ||
17711 			     (app_limited == CTF_JR_PRR))) {
17712 				/*
17713 				 * The reason we are not sending is
17714 				 * the cwnd (or prr). We have been configured
17715 				 * to end the measurement window in
17716 				 * this case.
17717 				 */
17718 				end_window = 1;
17719 			} else if (rack_rwnd_block_ends_measure &&
17720 				   (app_limited == CTF_JR_RWND_LIMITED)) {
17721 				/*
17722 				 * We are rwnd limited and have been
17723 				 * configured to end the measurement
17724 				 * window in this case.
17725 				 */
17726 				end_window = 1;
17727 			} else if (app_limited == CTF_JR_APP_LIMITED) {
17728 				/*
17729 				 * A true application limited period, we have
17730 				 * ran out of data.
17731 				 */
17732 				end_window = 1;
17733 			} else if (app_limited == CTF_JR_ASSESSING) {
17734 				/*
17735 				 * In the assessing case we hit the end of
17736 				 * the if/else and had no known reason
17737 				 * This will panic us under invariants..
17738 				 *
17739 				 * If we get this out in logs we need to
17740 				 * investagate which reason we missed.
17741 				 */
17742 				end_window = 1;
17743 			}
17744 			if (end_window) {
17745 				uint8_t log = 0;
17746 
17747 				/* Adjust the Gput measurement */
17748 				if ((tp->t_flags & TF_GPUTINPROG) &&
17749 				    SEQ_GT(tp->gput_ack, tp->snd_max)) {
17750 					tp->gput_ack = tp->snd_max;
17751 					if ((tp->gput_ack - tp->gput_seq) < (MIN_GP_WIN * segsiz)) {
17752 						/*
17753 						 * There is not enough to measure.
17754 						 */
17755 						tp->t_flags &= ~TF_GPUTINPROG;
17756 						rack_log_pacing_delay_calc(rack, (tp->gput_ack - tp->gput_seq) /*flex2*/,
17757 									   rack->r_ctl.rc_gp_srtt /*flex1*/,
17758 									   tp->gput_seq,
17759 									   0, 0, 18, __LINE__, NULL, 0);
17760 					} else
17761 						log = 1;
17762 				}
17763 				/* Mark the last packet has app limited */
17764 				rsm = RB_MAX(rack_rb_tree_head, &rack->r_ctl.rc_mtree);
17765 				if (rsm && ((rsm->r_flags & RACK_APP_LIMITED) == 0)) {
17766 					if (rack->r_ctl.rc_app_limited_cnt == 0)
17767 						rack->r_ctl.rc_end_appl = rack->r_ctl.rc_first_appl = rsm;
17768 					else {
17769 						/*
17770 						 * Go out to the end app limited and mark
17771 						 * this new one as next and move the end_appl up
17772 						 * to this guy.
17773 						 */
17774 						if (rack->r_ctl.rc_end_appl)
17775 							rack->r_ctl.rc_end_appl->r_nseq_appl = rsm->r_start;
17776 						rack->r_ctl.rc_end_appl = rsm;
17777 					}
17778 					rsm->r_flags |= RACK_APP_LIMITED;
17779 					rack->r_ctl.rc_app_limited_cnt++;
17780 				}
17781 				if (log)
17782 					rack_log_pacing_delay_calc(rack,
17783 								   rack->r_ctl.rc_app_limited_cnt, seq,
17784 								   tp->gput_ack, 0, 0, 4, __LINE__, NULL, 0);
17785 			}
17786 		}
17787 		/* Check if we need to go into persists or not */
17788 		if ((tp->snd_max == tp->snd_una) &&
17789 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
17790 		    sbavail(sb) &&
17791 		    (sbavail(sb) > tp->snd_wnd) &&
17792 		    (tp->snd_wnd < min((rack->r_ctl.rc_high_rwnd/2), minseg))) {
17793 			/* Yes lets make sure to move to persist before timer-start */
17794 			rack_enter_persist(tp, rack, rack->r_ctl.rc_rcvtime);
17795 		}
17796 		rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, sup_rack);
17797 		rack_log_type_just_return(rack, cts, tot_len_this_send, slot, hpts_calling, app_limited, cwnd_to_use);
17798 	}
17799 #ifdef NETFLIX_SHARED_CWND
17800 	if ((sbavail(sb) == 0) &&
17801 	    rack->r_ctl.rc_scw) {
17802 		tcp_shared_cwnd_idle(rack->r_ctl.rc_scw, rack->r_ctl.rc_scw_index);
17803 		rack->rack_scwnd_is_idle = 1;
17804 	}
17805 #endif
17806 #ifdef TCP_ACCOUNTING
17807 	if (tot_len_this_send > 0) {
17808 		crtsc = get_cyclecount();
17809 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17810 			tp->tcp_cnt_counters[SND_OUT_DATA]++;
17811 		}
17812 		counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], 1);
17813 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17814 			tp->tcp_proc_time[SND_OUT_DATA] += (crtsc - ts_val);
17815 		}
17816 		counter_u64_add(tcp_proc_time[SND_OUT_DATA], (crtsc - ts_val));
17817 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17818 			tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len_this_send + segsiz - 1) / segsiz);
17819 		}
17820 		counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((tot_len_this_send + segsiz - 1) / segsiz));
17821 	} else {
17822 		crtsc = get_cyclecount();
17823 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17824 			tp->tcp_cnt_counters[SND_LIMITED]++;
17825 		}
17826 		counter_u64_add(tcp_cnt_counters[SND_LIMITED], 1);
17827 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17828 			tp->tcp_proc_time[SND_LIMITED] += (crtsc - ts_val);
17829 		}
17830 		counter_u64_add(tcp_proc_time[SND_LIMITED], (crtsc - ts_val));
17831 	}
17832 	sched_unpin();
17833 #endif
17834 	return (0);
17835 
17836 send:
17837 	if (rsm || sack_rxmit)
17838 		counter_u64_add(rack_nfto_resend, 1);
17839 	else
17840 		counter_u64_add(rack_non_fto_send, 1);
17841 	if ((flags & TH_FIN) &&
17842 	    sbavail(sb)) {
17843 		/*
17844 		 * We do not transmit a FIN
17845 		 * with data outstanding. We
17846 		 * need to make it so all data
17847 		 * is acked first.
17848 		 */
17849 		flags &= ~TH_FIN;
17850 	}
17851 	/* Enforce stack imposed max seg size if we have one */
17852 	if (rack->r_ctl.rc_pace_max_segs &&
17853 	    (len > rack->r_ctl.rc_pace_max_segs)) {
17854 		mark = 1;
17855 		len = rack->r_ctl.rc_pace_max_segs;
17856 	}
17857 	SOCKBUF_LOCK_ASSERT(sb);
17858 	if (len > 0) {
17859 		if (len >= segsiz)
17860 			tp->t_flags2 |= TF2_PLPMTU_MAXSEGSNT;
17861 		else
17862 			tp->t_flags2 &= ~TF2_PLPMTU_MAXSEGSNT;
17863 	}
17864 	/*
17865 	 * Before ESTABLISHED, force sending of initial options unless TCP
17866 	 * set not to do any options. NOTE: we assume that the IP/TCP header
17867 	 * plus TCP options always fit in a single mbuf, leaving room for a
17868 	 * maximum link header, i.e. max_linkhdr + sizeof (struct tcpiphdr)
17869 	 * + optlen <= MCLBYTES
17870 	 */
17871 	optlen = 0;
17872 #ifdef INET6
17873 	if (isipv6)
17874 		hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
17875 	else
17876 #endif
17877 		hdrlen = sizeof(struct tcpiphdr);
17878 
17879 	/*
17880 	 * Compute options for segment. We only have to care about SYN and
17881 	 * established connection segments.  Options for SYN-ACK segments
17882 	 * are handled in TCP syncache.
17883 	 */
17884 	to.to_flags = 0;
17885 	if ((tp->t_flags & TF_NOOPT) == 0) {
17886 		/* Maximum segment size. */
17887 		if (flags & TH_SYN) {
17888 			tp->snd_nxt = tp->iss;
17889 			to.to_mss = tcp_mssopt(&inp->inp_inc);
17890 			if (tp->t_port)
17891 				to.to_mss -= V_tcp_udp_tunneling_overhead;
17892 			to.to_flags |= TOF_MSS;
17893 
17894 			/*
17895 			 * On SYN or SYN|ACK transmits on TFO connections,
17896 			 * only include the TFO option if it is not a
17897 			 * retransmit, as the presence of the TFO option may
17898 			 * have caused the original SYN or SYN|ACK to have
17899 			 * been dropped by a middlebox.
17900 			 */
17901 			if (IS_FASTOPEN(tp->t_flags) &&
17902 			    (tp->t_rxtshift == 0)) {
17903 				if (tp->t_state == TCPS_SYN_RECEIVED) {
17904 					to.to_tfo_len = TCP_FASTOPEN_COOKIE_LEN;
17905 					to.to_tfo_cookie =
17906 						(u_int8_t *)&tp->t_tfo_cookie.server;
17907 					to.to_flags |= TOF_FASTOPEN;
17908 					wanted_cookie = 1;
17909 				} else if (tp->t_state == TCPS_SYN_SENT) {
17910 					to.to_tfo_len =
17911 						tp->t_tfo_client_cookie_len;
17912 					to.to_tfo_cookie =
17913 						tp->t_tfo_cookie.client;
17914 					to.to_flags |= TOF_FASTOPEN;
17915 					wanted_cookie = 1;
17916 					/*
17917 					 * If we wind up having more data to
17918 					 * send with the SYN than can fit in
17919 					 * one segment, don't send any more
17920 					 * until the SYN|ACK comes back from
17921 					 * the other end.
17922 					 */
17923 					sendalot = 0;
17924 				}
17925 			}
17926 		}
17927 		/* Window scaling. */
17928 		if ((flags & TH_SYN) && (tp->t_flags & TF_REQ_SCALE)) {
17929 			to.to_wscale = tp->request_r_scale;
17930 			to.to_flags |= TOF_SCALE;
17931 		}
17932 		/* Timestamps. */
17933 		if ((tp->t_flags & TF_RCVD_TSTMP) ||
17934 		    ((flags & TH_SYN) && (tp->t_flags & TF_REQ_TSTMP))) {
17935 			to.to_tsval = ms_cts + tp->ts_offset;
17936 			to.to_tsecr = tp->ts_recent;
17937 			to.to_flags |= TOF_TS;
17938 		}
17939 		/* Set receive buffer autosizing timestamp. */
17940 		if (tp->rfbuf_ts == 0 &&
17941 		    (so->so_rcv.sb_flags & SB_AUTOSIZE))
17942 			tp->rfbuf_ts = tcp_ts_getticks();
17943 		/* Selective ACK's. */
17944 		if (tp->t_flags & TF_SACK_PERMIT) {
17945 			if (flags & TH_SYN)
17946 				to.to_flags |= TOF_SACKPERM;
17947 			else if (TCPS_HAVEESTABLISHED(tp->t_state) &&
17948 				 tp->rcv_numsacks > 0) {
17949 				to.to_flags |= TOF_SACK;
17950 				to.to_nsacks = tp->rcv_numsacks;
17951 				to.to_sacks = (u_char *)tp->sackblks;
17952 			}
17953 		}
17954 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
17955 		/* TCP-MD5 (RFC2385). */
17956 		if (tp->t_flags & TF_SIGNATURE)
17957 			to.to_flags |= TOF_SIGNATURE;
17958 #endif				/* TCP_SIGNATURE */
17959 
17960 		/* Processing the options. */
17961 		hdrlen += optlen = tcp_addoptions(&to, opt);
17962 		/*
17963 		 * If we wanted a TFO option to be added, but it was unable
17964 		 * to fit, ensure no data is sent.
17965 		 */
17966 		if (IS_FASTOPEN(tp->t_flags) && wanted_cookie &&
17967 		    !(to.to_flags & TOF_FASTOPEN))
17968 			len = 0;
17969 	}
17970 	if (tp->t_port) {
17971 		if (V_tcp_udp_tunneling_port == 0) {
17972 			/* The port was removed?? */
17973 			SOCKBUF_UNLOCK(&so->so_snd);
17974 #ifdef TCP_ACCOUNTING
17975 			crtsc = get_cyclecount();
17976 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17977 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
17978 			}
17979 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
17980 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
17981 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
17982 			}
17983 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
17984 			sched_unpin();
17985 #endif
17986 			return (EHOSTUNREACH);
17987 		}
17988 		hdrlen += sizeof(struct udphdr);
17989 	}
17990 #ifdef INET6
17991 	if (isipv6)
17992 		ipoptlen = ip6_optlen(tp->t_inpcb);
17993 	else
17994 #endif
17995 		if (tp->t_inpcb->inp_options)
17996 			ipoptlen = tp->t_inpcb->inp_options->m_len -
17997 				offsetof(struct ipoption, ipopt_list);
17998 		else
17999 			ipoptlen = 0;
18000 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
18001 	ipoptlen += ipsec_optlen;
18002 #endif
18003 
18004 	/*
18005 	 * Adjust data length if insertion of options will bump the packet
18006 	 * length beyond the t_maxseg length. Clear the FIN bit because we
18007 	 * cut off the tail of the segment.
18008 	 */
18009 	if (len + optlen + ipoptlen > tp->t_maxseg) {
18010 		if (tso) {
18011 			uint32_t if_hw_tsomax;
18012 			uint32_t moff;
18013 			int32_t max_len;
18014 
18015 			/* extract TSO information */
18016 			if_hw_tsomax = tp->t_tsomax;
18017 			if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
18018 			if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
18019 			KASSERT(ipoptlen == 0,
18020 				("%s: TSO can't do IP options", __func__));
18021 
18022 			/*
18023 			 * Check if we should limit by maximum payload
18024 			 * length:
18025 			 */
18026 			if (if_hw_tsomax != 0) {
18027 				/* compute maximum TSO length */
18028 				max_len = (if_hw_tsomax - hdrlen -
18029 					   max_linkhdr);
18030 				if (max_len <= 0) {
18031 					len = 0;
18032 				} else if (len > max_len) {
18033 					sendalot = 1;
18034 					len = max_len;
18035 					mark = 2;
18036 				}
18037 			}
18038 			/*
18039 			 * Prevent the last segment from being fractional
18040 			 * unless the send sockbuf can be emptied:
18041 			 */
18042 			max_len = (tp->t_maxseg - optlen);
18043 			if ((sb_offset + len) < sbavail(sb)) {
18044 				moff = len % (u_int)max_len;
18045 				if (moff != 0) {
18046 					mark = 3;
18047 					len -= moff;
18048 				}
18049 			}
18050 			/*
18051 			 * In case there are too many small fragments don't
18052 			 * use TSO:
18053 			 */
18054 			if (len <= segsiz) {
18055 				mark = 4;
18056 				tso = 0;
18057 			}
18058 			/*
18059 			 * Send the FIN in a separate segment after the bulk
18060 			 * sending is done. We don't trust the TSO
18061 			 * implementations to clear the FIN flag on all but
18062 			 * the last segment.
18063 			 */
18064 			if (tp->t_flags & TF_NEEDFIN) {
18065 				sendalot = 4;
18066 			}
18067 		} else {
18068 			mark = 5;
18069 			if (optlen + ipoptlen >= tp->t_maxseg) {
18070 				/*
18071 				 * Since we don't have enough space to put
18072 				 * the IP header chain and the TCP header in
18073 				 * one packet as required by RFC 7112, don't
18074 				 * send it. Also ensure that at least one
18075 				 * byte of the payload can be put into the
18076 				 * TCP segment.
18077 				 */
18078 				SOCKBUF_UNLOCK(&so->so_snd);
18079 				error = EMSGSIZE;
18080 				sack_rxmit = 0;
18081 				goto out;
18082 			}
18083 			len = tp->t_maxseg - optlen - ipoptlen;
18084 			sendalot = 5;
18085 		}
18086 	} else {
18087 		tso = 0;
18088 		mark = 6;
18089 	}
18090 	KASSERT(len + hdrlen + ipoptlen <= IP_MAXPACKET,
18091 		("%s: len > IP_MAXPACKET", __func__));
18092 #ifdef DIAGNOSTIC
18093 #ifdef INET6
18094 	if (max_linkhdr + hdrlen > MCLBYTES)
18095 #else
18096 		if (max_linkhdr + hdrlen > MHLEN)
18097 #endif
18098 			panic("tcphdr too big");
18099 #endif
18100 
18101 	/*
18102 	 * This KASSERT is here to catch edge cases at a well defined place.
18103 	 * Before, those had triggered (random) panic conditions further
18104 	 * down.
18105 	 */
18106 	KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
18107 	if ((len == 0) &&
18108 	    (flags & TH_FIN) &&
18109 	    (sbused(sb))) {
18110 		/*
18111 		 * We have outstanding data, don't send a fin by itself!.
18112 		 */
18113 		goto just_return;
18114 	}
18115 	/*
18116 	 * Grab a header mbuf, attaching a copy of data to be transmitted,
18117 	 * and initialize the header from the template for sends on this
18118 	 * connection.
18119 	 */
18120 	hw_tls = (sb->sb_flags & SB_TLS_IFNET) != 0;
18121 	if (len) {
18122 		uint32_t max_val;
18123 		uint32_t moff;
18124 
18125 		if (rack->r_ctl.rc_pace_max_segs)
18126 			max_val = rack->r_ctl.rc_pace_max_segs;
18127 		else if (rack->rc_user_set_max_segs)
18128 			max_val = rack->rc_user_set_max_segs * segsiz;
18129 		else
18130 			max_val = len;
18131 		/*
18132 		 * We allow a limit on sending with hptsi.
18133 		 */
18134 		if (len > max_val) {
18135 			mark = 7;
18136 			len = max_val;
18137 		}
18138 #ifdef INET6
18139 		if (MHLEN < hdrlen + max_linkhdr)
18140 			m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
18141 		else
18142 #endif
18143 			m = m_gethdr(M_NOWAIT, MT_DATA);
18144 
18145 		if (m == NULL) {
18146 			SOCKBUF_UNLOCK(sb);
18147 			error = ENOBUFS;
18148 			sack_rxmit = 0;
18149 			goto out;
18150 		}
18151 		m->m_data += max_linkhdr;
18152 		m->m_len = hdrlen;
18153 
18154 		/*
18155 		 * Start the m_copy functions from the closest mbuf to the
18156 		 * sb_offset in the socket buffer chain.
18157 		 */
18158 		mb = sbsndptr_noadv(sb, sb_offset, &moff);
18159 		s_mb = mb;
18160 		s_moff = moff;
18161 		if (len <= MHLEN - hdrlen - max_linkhdr && !hw_tls) {
18162 			m_copydata(mb, moff, (int)len,
18163 				   mtod(m, caddr_t)+hdrlen);
18164 			if (SEQ_LT(tp->snd_nxt, tp->snd_max))
18165 				sbsndptr_adv(sb, mb, len);
18166 			m->m_len += len;
18167 		} else {
18168 			struct sockbuf *msb;
18169 
18170 			if (SEQ_LT(tp->snd_nxt, tp->snd_max))
18171 				msb = NULL;
18172 			else
18173 				msb = sb;
18174 			m->m_next = tcp_m_copym(
18175 				mb, moff, &len,
18176 				if_hw_tsomaxsegcount, if_hw_tsomaxsegsize, msb,
18177 				((rsm == NULL) ? hw_tls : 0)
18178 #ifdef NETFLIX_COPY_ARGS
18179 				, &filled_all
18180 #endif
18181 				);
18182 			if (len <= (tp->t_maxseg - optlen)) {
18183 				/*
18184 				 * Must have ran out of mbufs for the copy
18185 				 * shorten it to no longer need tso. Lets
18186 				 * not put on sendalot since we are low on
18187 				 * mbufs.
18188 				 */
18189 				tso = 0;
18190 			}
18191 			if (m->m_next == NULL) {
18192 				SOCKBUF_UNLOCK(sb);
18193 				(void)m_free(m);
18194 				error = ENOBUFS;
18195 				sack_rxmit = 0;
18196 				goto out;
18197 			}
18198 		}
18199 		if (SEQ_LT(tp->snd_nxt, tp->snd_max) || sack_rxmit) {
18200 			if (rsm && (rsm->r_flags & RACK_TLP)) {
18201 				/*
18202 				 * TLP should not count in retran count, but
18203 				 * in its own bin
18204 				 */
18205 				counter_u64_add(rack_tlp_retran, 1);
18206 				counter_u64_add(rack_tlp_retran_bytes, len);
18207 			} else {
18208 				tp->t_sndrexmitpack++;
18209 				KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
18210 				KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
18211 			}
18212 #ifdef STATS
18213 			stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
18214 						 len);
18215 #endif
18216 		} else {
18217 			KMOD_TCPSTAT_INC(tcps_sndpack);
18218 			KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
18219 #ifdef STATS
18220 			stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
18221 						 len);
18222 #endif
18223 		}
18224 		/*
18225 		 * If we're sending everything we've got, set PUSH. (This
18226 		 * will keep happy those implementations which only give
18227 		 * data to the user when a buffer fills or a PUSH comes in.)
18228 		 */
18229 		if (sb_offset + len == sbused(sb) &&
18230 		    sbused(sb) &&
18231 		    !(flags & TH_SYN)) {
18232 			flags |= TH_PUSH;
18233 			add_flag |= RACK_HAD_PUSH;
18234 		}
18235 
18236 		SOCKBUF_UNLOCK(sb);
18237 	} else {
18238 		SOCKBUF_UNLOCK(sb);
18239 		if (tp->t_flags & TF_ACKNOW)
18240 			KMOD_TCPSTAT_INC(tcps_sndacks);
18241 		else if (flags & (TH_SYN | TH_FIN | TH_RST))
18242 			KMOD_TCPSTAT_INC(tcps_sndctrl);
18243 		else
18244 			KMOD_TCPSTAT_INC(tcps_sndwinup);
18245 
18246 		m = m_gethdr(M_NOWAIT, MT_DATA);
18247 		if (m == NULL) {
18248 			error = ENOBUFS;
18249 			sack_rxmit = 0;
18250 			goto out;
18251 		}
18252 #ifdef INET6
18253 		if (isipv6 && (MHLEN < hdrlen + max_linkhdr) &&
18254 		    MHLEN >= hdrlen) {
18255 			M_ALIGN(m, hdrlen);
18256 		} else
18257 #endif
18258 			m->m_data += max_linkhdr;
18259 		m->m_len = hdrlen;
18260 	}
18261 	SOCKBUF_UNLOCK_ASSERT(sb);
18262 	m->m_pkthdr.rcvif = (struct ifnet *)0;
18263 #ifdef MAC
18264 	mac_inpcb_create_mbuf(inp, m);
18265 #endif
18266 	if ((ipoptlen == 0) && (rack->r_ctl.fsb.tcp_ip_hdr) &&  rack->r_fsb_inited) {
18267 #ifdef INET6
18268 		if (isipv6)
18269 			ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
18270 		else
18271 #endif				/* INET6 */
18272 			ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
18273 		th = rack->r_ctl.fsb.th;
18274 		udp = rack->r_ctl.fsb.udp;
18275 		if (udp) {
18276 #ifdef INET6
18277 			if (isipv6)
18278 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
18279 			else
18280 #endif				/* INET6 */
18281 				ulen = hdrlen + len - sizeof(struct ip);
18282 			udp->uh_ulen = htons(ulen);
18283 		}
18284 	} else {
18285 #ifdef INET6
18286 		if (isipv6) {
18287 			ip6 = mtod(m, struct ip6_hdr *);
18288 			if (tp->t_port) {
18289 				udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
18290 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
18291 				udp->uh_dport = tp->t_port;
18292 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
18293 				udp->uh_ulen = htons(ulen);
18294 				th = (struct tcphdr *)(udp + 1);
18295 			} else
18296 				th = (struct tcphdr *)(ip6 + 1);
18297 			tcpip_fillheaders(inp, tp->t_port, ip6, th);
18298 		} else
18299 #endif				/* INET6 */
18300 		{
18301 			ip = mtod(m, struct ip *);
18302 			if (tp->t_port) {
18303 				udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
18304 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
18305 				udp->uh_dport = tp->t_port;
18306 				ulen = hdrlen + len - sizeof(struct ip);
18307 				udp->uh_ulen = htons(ulen);
18308 				th = (struct tcphdr *)(udp + 1);
18309 			} else
18310 				th = (struct tcphdr *)(ip + 1);
18311 			tcpip_fillheaders(inp, tp->t_port, ip, th);
18312 		}
18313 	}
18314 	/*
18315 	 * Fill in fields, remembering maximum advertised window for use in
18316 	 * delaying messages about window sizes. If resending a FIN, be sure
18317 	 * not to use a new sequence number.
18318 	 */
18319 	if (flags & TH_FIN && tp->t_flags & TF_SENTFIN &&
18320 	    tp->snd_nxt == tp->snd_max)
18321 		tp->snd_nxt--;
18322 	/*
18323 	 * If we are starting a connection, send ECN setup SYN packet. If we
18324 	 * are on a retransmit, we may resend those bits a number of times
18325 	 * as per RFC 3168.
18326 	 */
18327 	if (tp->t_state == TCPS_SYN_SENT && V_tcp_do_ecn) {
18328 		flags |= tcp_ecn_output_syn_sent(tp);
18329 	}
18330 	/* Also handle parallel SYN for ECN */
18331 	if (TCPS_HAVERCVDSYN(tp->t_state) &&
18332 	    (tp->t_flags2 & TF2_ECN_PERMIT)) {
18333 		int ect = tcp_ecn_output_established(tp, &flags, len, sack_rxmit);
18334 		if ((tp->t_state == TCPS_SYN_RECEIVED) &&
18335 		    (tp->t_flags2 & TF2_ECN_SND_ECE))
18336 			tp->t_flags2 &= ~TF2_ECN_SND_ECE;
18337 #ifdef INET6
18338 		if (isipv6) {
18339 			ip6->ip6_flow &= ~htonl(IPTOS_ECN_MASK << 20);
18340 			ip6->ip6_flow |= htonl(ect << 20);
18341 		}
18342 		else
18343 #endif
18344 		{
18345 			ip->ip_tos &= ~IPTOS_ECN_MASK;
18346 			ip->ip_tos |= ect;
18347 		}
18348 	}
18349 	/*
18350 	 * If we are doing retransmissions, then snd_nxt will not reflect
18351 	 * the first unsent octet.  For ACK only packets, we do not want the
18352 	 * sequence number of the retransmitted packet, we want the sequence
18353 	 * number of the next unsent octet.  So, if there is no data (and no
18354 	 * SYN or FIN), use snd_max instead of snd_nxt when filling in
18355 	 * ti_seq.  But if we are in persist state, snd_max might reflect
18356 	 * one byte beyond the right edge of the window, so use snd_nxt in
18357 	 * that case, since we know we aren't doing a retransmission.
18358 	 * (retransmit and persist are mutually exclusive...)
18359 	 */
18360 	if (sack_rxmit == 0) {
18361 		if (len || (flags & (TH_SYN | TH_FIN))) {
18362 			th->th_seq = htonl(tp->snd_nxt);
18363 			rack_seq = tp->snd_nxt;
18364 		} else {
18365 			th->th_seq = htonl(tp->snd_max);
18366 			rack_seq = tp->snd_max;
18367 		}
18368 	} else {
18369 		th->th_seq = htonl(rsm->r_start);
18370 		rack_seq = rsm->r_start;
18371 	}
18372 	th->th_ack = htonl(tp->rcv_nxt);
18373 	tcp_set_flags(th, flags);
18374 	/*
18375 	 * Calculate receive window.  Don't shrink window, but avoid silly
18376 	 * window syndrome.
18377 	 * If a RST segment is sent, advertise a window of zero.
18378 	 */
18379 	if (flags & TH_RST) {
18380 		recwin = 0;
18381 	} else {
18382 		if (recwin < (long)(so->so_rcv.sb_hiwat / 4) &&
18383 		    recwin < (long)segsiz) {
18384 			recwin = 0;
18385 		}
18386 		if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) &&
18387 		    recwin < (long)(tp->rcv_adv - tp->rcv_nxt))
18388 			recwin = (long)(tp->rcv_adv - tp->rcv_nxt);
18389 	}
18390 
18391 	/*
18392 	 * According to RFC1323 the window field in a SYN (i.e., a <SYN> or
18393 	 * <SYN,ACK>) segment itself is never scaled.  The <SYN,ACK> case is
18394 	 * handled in syncache.
18395 	 */
18396 	if (flags & TH_SYN)
18397 		th->th_win = htons((u_short)
18398 				   (min(sbspace(&so->so_rcv), TCP_MAXWIN)));
18399 	else {
18400 		/* Avoid shrinking window with window scaling. */
18401 		recwin = roundup2(recwin, 1 << tp->rcv_scale);
18402 		th->th_win = htons((u_short)(recwin >> tp->rcv_scale));
18403 	}
18404 	/*
18405 	 * Adjust the RXWIN0SENT flag - indicate that we have advertised a 0
18406 	 * window.  This may cause the remote transmitter to stall.  This
18407 	 * flag tells soreceive() to disable delayed acknowledgements when
18408 	 * draining the buffer.  This can occur if the receiver is
18409 	 * attempting to read more data than can be buffered prior to
18410 	 * transmitting on the connection.
18411 	 */
18412 	if (th->th_win == 0) {
18413 		tp->t_sndzerowin++;
18414 		tp->t_flags |= TF_RXWIN0SENT;
18415 	} else
18416 		tp->t_flags &= ~TF_RXWIN0SENT;
18417 	tp->snd_up = tp->snd_una;	/* drag it along, its deprecated */
18418 	/* Now are we using fsb?, if so copy the template data to the mbuf */
18419 	if ((ipoptlen == 0) && (rack->r_ctl.fsb.tcp_ip_hdr) && rack->r_fsb_inited) {
18420 		uint8_t *cpto;
18421 
18422 		cpto = mtod(m, uint8_t *);
18423 		memcpy(cpto, rack->r_ctl.fsb.tcp_ip_hdr, rack->r_ctl.fsb.tcp_ip_hdr_len);
18424 		/*
18425 		 * We have just copied in:
18426 		 * IP/IP6
18427 		 * <optional udphdr>
18428 		 * tcphdr (no options)
18429 		 *
18430 		 * We need to grab the correct pointers into the mbuf
18431 		 * for both the tcp header, and possibly the udp header (if tunneling).
18432 		 * We do this by using the offset in the copy buffer and adding it
18433 		 * to the mbuf base pointer (cpto).
18434 		 */
18435 #ifdef INET6
18436 		if (isipv6)
18437 			ip6 = mtod(m, struct ip6_hdr *);
18438 		else
18439 #endif				/* INET6 */
18440 			ip = mtod(m, struct ip *);
18441 		th = (struct tcphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.th - rack->r_ctl.fsb.tcp_ip_hdr));
18442 		/* If we have a udp header lets set it into the mbuf as well */
18443 		if (udp)
18444 			udp = (struct udphdr *)(cpto + ((uint8_t *)rack->r_ctl.fsb.udp - rack->r_ctl.fsb.tcp_ip_hdr));
18445 	}
18446 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
18447 	if (to.to_flags & TOF_SIGNATURE) {
18448 		/*
18449 		 * Calculate MD5 signature and put it into the place
18450 		 * determined before.
18451 		 * NOTE: since TCP options buffer doesn't point into
18452 		 * mbuf's data, calculate offset and use it.
18453 		 */
18454 		if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
18455 						       (u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
18456 			/*
18457 			 * Do not send segment if the calculation of MD5
18458 			 * digest has failed.
18459 			 */
18460 			goto out;
18461 		}
18462 	}
18463 #endif
18464 	if (optlen) {
18465 		bcopy(opt, th + 1, optlen);
18466 		th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
18467 	}
18468 	/*
18469 	 * Put TCP length in extended header, and then checksum extended
18470 	 * header and data.
18471 	 */
18472 	m->m_pkthdr.len = hdrlen + len;	/* in6_cksum() need this */
18473 #ifdef INET6
18474 	if (isipv6) {
18475 		/*
18476 		 * ip6_plen is not need to be filled now, and will be filled
18477 		 * in ip6_output.
18478 		 */
18479 		if (tp->t_port) {
18480 			m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
18481 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
18482 			udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
18483 			th->th_sum = htons(0);
18484 			UDPSTAT_INC(udps_opackets);
18485 		} else {
18486 			m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
18487 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
18488 			th->th_sum = in6_cksum_pseudo(ip6,
18489 						      sizeof(struct tcphdr) + optlen + len, IPPROTO_TCP,
18490 						      0);
18491 		}
18492 	}
18493 #endif
18494 #if defined(INET6) && defined(INET)
18495 	else
18496 #endif
18497 #ifdef INET
18498 	{
18499 		if (tp->t_port) {
18500 			m->m_pkthdr.csum_flags = CSUM_UDP;
18501 			m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
18502 			udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
18503 						ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
18504 			th->th_sum = htons(0);
18505 			UDPSTAT_INC(udps_opackets);
18506 		} else {
18507 			m->m_pkthdr.csum_flags = CSUM_TCP;
18508 			m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
18509 			th->th_sum = in_pseudo(ip->ip_src.s_addr,
18510 					       ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
18511 									IPPROTO_TCP + len + optlen));
18512 		}
18513 		/* IP version must be set here for ipv4/ipv6 checking later */
18514 		KASSERT(ip->ip_v == IPVERSION,
18515 			("%s: IP version incorrect: %d", __func__, ip->ip_v));
18516 	}
18517 #endif
18518 	/*
18519 	 * Enable TSO and specify the size of the segments. The TCP pseudo
18520 	 * header checksum is always provided. XXX: Fixme: This is currently
18521 	 * not the case for IPv6.
18522 	 */
18523 	if (tso) {
18524 		KASSERT(len > tp->t_maxseg - optlen,
18525 			("%s: len <= tso_segsz", __func__));
18526 		m->m_pkthdr.csum_flags |= CSUM_TSO;
18527 		m->m_pkthdr.tso_segsz = tp->t_maxseg - optlen;
18528 	}
18529 	KASSERT(len + hdrlen == m_length(m, NULL),
18530 		("%s: mbuf chain different than expected: %d + %u != %u",
18531 		 __func__, len, hdrlen, m_length(m, NULL)));
18532 
18533 #ifdef TCP_HHOOK
18534 	/* Run HHOOK_TCP_ESTABLISHED_OUT helper hooks. */
18535 	hhook_run_tcp_est_out(tp, th, &to, len, tso);
18536 #endif
18537 	/* We're getting ready to send; log now. */
18538 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
18539 		union tcp_log_stackspecific log;
18540 
18541 		memset(&log.u_bbr, 0, sizeof(log.u_bbr));
18542 		log.u_bbr.inhpts = tcp_in_hpts(rack->rc_inp);
18543 		if (rack->rack_no_prr)
18544 			log.u_bbr.flex1 = 0;
18545 		else
18546 			log.u_bbr.flex1 = rack->r_ctl.rc_prr_sndcnt;
18547 		log.u_bbr.flex2 = rack->r_ctl.rc_pace_min_segs;
18548 		log.u_bbr.flex3 = rack->r_ctl.rc_pace_max_segs;
18549 		log.u_bbr.flex4 = orig_len;
18550 		if (filled_all)
18551 			log.u_bbr.flex5 = 0x80000000;
18552 		else
18553 			log.u_bbr.flex5 = 0;
18554 		/* Save off the early/late values */
18555 		log.u_bbr.flex6 = rack->r_ctl.rc_agg_early;
18556 		log.u_bbr.applimited = rack->r_ctl.rc_agg_delayed;
18557 		log.u_bbr.bw_inuse = rack_get_bw(rack);
18558 		if (rsm || sack_rxmit) {
18559 			if (doing_tlp)
18560 				log.u_bbr.flex8 = 2;
18561 			else
18562 				log.u_bbr.flex8 = 1;
18563 		} else {
18564 			if (doing_tlp)
18565 				log.u_bbr.flex8 = 3;
18566 			else
18567 				log.u_bbr.flex8 = 0;
18568 		}
18569 		log.u_bbr.pacing_gain = rack_get_output_gain(rack, rsm);
18570 		log.u_bbr.flex7 = mark;
18571 		log.u_bbr.flex7 <<= 8;
18572 		log.u_bbr.flex7 |= pass;
18573 		log.u_bbr.pkts_out = tp->t_maxseg;
18574 		log.u_bbr.timeStamp = cts;
18575 		log.u_bbr.inflight = ctf_flight_size(rack->rc_tp, rack->r_ctl.rc_sacked);
18576 		log.u_bbr.lt_epoch = cwnd_to_use;
18577 		log.u_bbr.delivered = sendalot;
18578 		lgb = tcp_log_event_(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_OUT, ERRNO_UNK,
18579 				     len, &log, false, NULL, NULL, 0, &tv);
18580 	} else
18581 		lgb = NULL;
18582 
18583 	/*
18584 	 * Fill in IP length and desired time to live and send to IP level.
18585 	 * There should be a better way to handle ttl and tos; we could keep
18586 	 * them in the template, but need a way to checksum without them.
18587 	 */
18588 	/*
18589 	 * m->m_pkthdr.len should have been set before cksum calcuration,
18590 	 * because in6_cksum() need it.
18591 	 */
18592 #ifdef INET6
18593 	if (isipv6) {
18594 		/*
18595 		 * we separately set hoplimit for every segment, since the
18596 		 * user might want to change the value via setsockopt. Also,
18597 		 * desired default hop limit might be changed via Neighbor
18598 		 * Discovery.
18599 		 */
18600 		rack->r_ctl.fsb.hoplimit = ip6->ip6_hlim = in6_selecthlim(inp, NULL);
18601 
18602 		/*
18603 		 * Set the packet size here for the benefit of DTrace
18604 		 * probes. ip6_output() will set it properly; it's supposed
18605 		 * to include the option header lengths as well.
18606 		 */
18607 		ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
18608 
18609 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss)
18610 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
18611 		else
18612 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
18613 
18614 		if (tp->t_state == TCPS_SYN_SENT)
18615 			TCP_PROBE5(connect__request, NULL, tp, ip6, tp, th);
18616 
18617 		TCP_PROBE5(send, NULL, tp, ip6, tp, th);
18618 		/* TODO: IPv6 IP6TOS_ECT bit on */
18619 		error = ip6_output(m,
18620 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
18621 				   inp->in6p_outputopts,
18622 #else
18623 				   NULL,
18624 #endif
18625 				   &inp->inp_route6,
18626 				   ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0),
18627 				   NULL, NULL, inp);
18628 
18629 		if (error == EMSGSIZE && inp->inp_route6.ro_nh != NULL)
18630 			mtu = inp->inp_route6.ro_nh->nh_mtu;
18631 	}
18632 #endif				/* INET6 */
18633 #if defined(INET) && defined(INET6)
18634 	else
18635 #endif
18636 #ifdef INET
18637 	{
18638 		ip->ip_len = htons(m->m_pkthdr.len);
18639 #ifdef INET6
18640 		if (inp->inp_vflag & INP_IPV6PROTO)
18641 			ip->ip_ttl = in6_selecthlim(inp, NULL);
18642 #endif				/* INET6 */
18643 		rack->r_ctl.fsb.hoplimit = ip->ip_ttl;
18644 		/*
18645 		 * If we do path MTU discovery, then we set DF on every
18646 		 * packet. This might not be the best thing to do according
18647 		 * to RFC3390 Section 2. However the tcp hostcache migitates
18648 		 * the problem so it affects only the first tcp connection
18649 		 * with a host.
18650 		 *
18651 		 * NB: Don't set DF on small MTU/MSS to have a safe
18652 		 * fallback.
18653 		 */
18654 		if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
18655 			tp->t_flags2 |= TF2_PLPMTU_PMTUD;
18656 			if (tp->t_port == 0 || len < V_tcp_minmss) {
18657 				ip->ip_off |= htons(IP_DF);
18658 			}
18659 		} else {
18660 			tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
18661 		}
18662 
18663 		if (tp->t_state == TCPS_SYN_SENT)
18664 			TCP_PROBE5(connect__request, NULL, tp, ip, tp, th);
18665 
18666 		TCP_PROBE5(send, NULL, tp, ip, tp, th);
18667 
18668 		error = ip_output(m,
18669 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
18670 				  inp->inp_options,
18671 #else
18672 				  NULL,
18673 #endif
18674 				  &inp->inp_route,
18675 				  ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0), 0,
18676 				  inp);
18677 		if (error == EMSGSIZE && inp->inp_route.ro_nh != NULL)
18678 			mtu = inp->inp_route.ro_nh->nh_mtu;
18679 	}
18680 #endif				/* INET */
18681 
18682 out:
18683 	if (lgb) {
18684 		lgb->tlb_errno = error;
18685 		lgb = NULL;
18686 	}
18687 	/*
18688 	 * In transmit state, time the transmission and arrange for the
18689 	 * retransmit.  In persist state, just set snd_max.
18690 	 */
18691 	if (error == 0) {
18692 		tcp_account_for_send(tp, len, (rsm != NULL), doing_tlp, hw_tls);
18693 		if (rsm && doing_tlp) {
18694 			rack->rc_last_sent_tlp_past_cumack = 0;
18695 			rack->rc_last_sent_tlp_seq_valid = 1;
18696 			rack->r_ctl.last_sent_tlp_seq = rsm->r_start;
18697 			rack->r_ctl.last_sent_tlp_len = rsm->r_end - rsm->r_start;
18698 		}
18699 		rack->forced_ack = 0;	/* If we send something zap the FA flag */
18700 		if (rsm && (doing_tlp == 0)) {
18701 			/* Set we retransmitted */
18702 			rack->rc_gp_saw_rec = 1;
18703 		} else {
18704 			if (cwnd_to_use > tp->snd_ssthresh) {
18705 				/* Set we sent in CA */
18706 				rack->rc_gp_saw_ca = 1;
18707 			} else {
18708 				/* Set we sent in SS */
18709 				rack->rc_gp_saw_ss = 1;
18710 			}
18711 		}
18712 		if (TCPS_HAVEESTABLISHED(tp->t_state) &&
18713 		    (tp->t_flags & TF_SACK_PERMIT) &&
18714 		    tp->rcv_numsacks > 0)
18715 			tcp_clean_dsack_blocks(tp);
18716 		tot_len_this_send += len;
18717 		if (len == 0)
18718 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_SNDACK], 1);
18719 		else if (len == 1) {
18720 			counter_u64_add(rack_out_size[TCP_MSS_ACCT_PERSIST], 1);
18721 		} else if (len > 1) {
18722 			int idx;
18723 
18724 			idx = (len / segsiz) + 3;
18725 			if (idx >= TCP_MSS_ACCT_ATIMER)
18726 				counter_u64_add(rack_out_size[(TCP_MSS_ACCT_ATIMER-1)], 1);
18727 			else
18728 				counter_u64_add(rack_out_size[idx], 1);
18729 		}
18730 	}
18731 	if ((rack->rack_no_prr == 0) &&
18732 	    sub_from_prr &&
18733 	    (error == 0)) {
18734 		if (rack->r_ctl.rc_prr_sndcnt >= len)
18735 			rack->r_ctl.rc_prr_sndcnt -= len;
18736 		else
18737 			rack->r_ctl.rc_prr_sndcnt = 0;
18738 	}
18739 	sub_from_prr = 0;
18740 	if (doing_tlp) {
18741 		/* Make sure the TLP is added */
18742 		add_flag |= RACK_TLP;
18743 	} else if (rsm) {
18744 		/* If its a resend without TLP then it must not have the flag */
18745 		rsm->r_flags &= ~RACK_TLP;
18746 	}
18747 	rack_log_output(tp, &to, len, rack_seq, (uint8_t) flags, error,
18748 			rack_to_usec_ts(&tv),
18749 			rsm, add_flag, s_mb, s_moff, hw_tls);
18750 
18751 
18752 	if ((error == 0) &&
18753 	    (len > 0) &&
18754 	    (tp->snd_una == tp->snd_max))
18755 		rack->r_ctl.rc_tlp_rxt_last_time = cts;
18756 	{
18757 		tcp_seq startseq = tp->snd_nxt;
18758 
18759 		/* Track our lost count */
18760 		if (rsm && (doing_tlp == 0))
18761 			rack->r_ctl.rc_loss_count += rsm->r_end - rsm->r_start;
18762 		/*
18763 		 * Advance snd_nxt over sequence space of this segment.
18764 		 */
18765 		if (error)
18766 			/* We don't log or do anything with errors */
18767 			goto nomore;
18768 		if (doing_tlp == 0) {
18769 			if (rsm == NULL) {
18770 				/*
18771 				 * Not a retransmission of some
18772 				 * sort, new data is going out so
18773 				 * clear our TLP count and flag.
18774 				 */
18775 				rack->rc_tlp_in_progress = 0;
18776 				rack->r_ctl.rc_tlp_cnt_out = 0;
18777 			}
18778 		} else {
18779 			/*
18780 			 * We have just sent a TLP, mark that it is true
18781 			 * and make sure our in progress is set so we
18782 			 * continue to check the count.
18783 			 */
18784 			rack->rc_tlp_in_progress = 1;
18785 			rack->r_ctl.rc_tlp_cnt_out++;
18786 		}
18787 		if (flags & (TH_SYN | TH_FIN)) {
18788 			if (flags & TH_SYN)
18789 				tp->snd_nxt++;
18790 			if (flags & TH_FIN) {
18791 				tp->snd_nxt++;
18792 				tp->t_flags |= TF_SENTFIN;
18793 			}
18794 		}
18795 		/* In the ENOBUFS case we do *not* update snd_max */
18796 		if (sack_rxmit)
18797 			goto nomore;
18798 
18799 		tp->snd_nxt += len;
18800 		if (SEQ_GT(tp->snd_nxt, tp->snd_max)) {
18801 			if (tp->snd_una == tp->snd_max) {
18802 				/*
18803 				 * Update the time we just added data since
18804 				 * none was outstanding.
18805 				 */
18806 				rack_log_progress_event(rack, tp, ticks, PROGRESS_START, __LINE__);
18807 				tp->t_acktime = ticks;
18808 			}
18809 			tp->snd_max = tp->snd_nxt;
18810 			/*
18811 			 * Time this transmission if not a retransmission and
18812 			 * not currently timing anything.
18813 			 * This is only relevant in case of switching back to
18814 			 * the base stack.
18815 			 */
18816 			if (tp->t_rtttime == 0) {
18817 				tp->t_rtttime = ticks;
18818 				tp->t_rtseq = startseq;
18819 				KMOD_TCPSTAT_INC(tcps_segstimed);
18820 			}
18821 			if (len &&
18822 			    ((tp->t_flags & TF_GPUTINPROG) == 0))
18823 				rack_start_gp_measurement(tp, rack, startseq, sb_offset);
18824 		}
18825 		/*
18826 		 * If we are doing FO we need to update the mbuf position and subtract
18827 		 * this happens when the peer sends us duplicate information and
18828 		 * we thus want to send a DSACK.
18829 		 *
18830 		 * XXXRRS: This brings to mind a ?, when we send a DSACK block is TSO
18831 		 * turned off? If not then we are going to echo multiple DSACK blocks
18832 		 * out (with the TSO), which we should not be doing.
18833 		 */
18834 		if (rack->r_fast_output && len) {
18835 			if (rack->r_ctl.fsb.left_to_send > len)
18836 				rack->r_ctl.fsb.left_to_send -= len;
18837 			else
18838 				rack->r_ctl.fsb.left_to_send = 0;
18839 			if (rack->r_ctl.fsb.left_to_send < segsiz)
18840 				rack->r_fast_output = 0;
18841 			if (rack->r_fast_output) {
18842 				rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
18843 				rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
18844 			}
18845 		}
18846 	}
18847 nomore:
18848 	if (error) {
18849 		rack->r_ctl.rc_agg_delayed = 0;
18850 		rack->r_early = 0;
18851 		rack->r_late = 0;
18852 		rack->r_ctl.rc_agg_early = 0;
18853 		SOCKBUF_UNLOCK_ASSERT(sb);	/* Check gotos. */
18854 		/*
18855 		 * Failures do not advance the seq counter above. For the
18856 		 * case of ENOBUFS we will fall out and retry in 1ms with
18857 		 * the hpts. Everything else will just have to retransmit
18858 		 * with the timer.
18859 		 *
18860 		 * In any case, we do not want to loop around for another
18861 		 * send without a good reason.
18862 		 */
18863 		sendalot = 0;
18864 		switch (error) {
18865 		case EPERM:
18866 			tp->t_softerror = error;
18867 #ifdef TCP_ACCOUNTING
18868 			crtsc = get_cyclecount();
18869 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18870 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
18871 			}
18872 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
18873 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18874 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
18875 			}
18876 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
18877 			sched_unpin();
18878 #endif
18879 			return (error);
18880 		case ENOBUFS:
18881 			/*
18882 			 * Pace us right away to retry in a some
18883 			 * time
18884 			 */
18885 			if (rack->r_ctl.crte != NULL) {
18886 				rack_trace_point(rack, RACK_TP_HWENOBUF);
18887 			} else
18888 				rack_trace_point(rack, RACK_TP_ENOBUF);
18889 			slot = ((1 + rack->rc_enobuf) * HPTS_USEC_IN_MSEC);
18890 			if (rack->rc_enobuf < 0x7f)
18891 				rack->rc_enobuf++;
18892 			if (slot < (10 * HPTS_USEC_IN_MSEC))
18893 				slot = 10 * HPTS_USEC_IN_MSEC;
18894 			if (rack->r_ctl.crte != NULL) {
18895 				counter_u64_add(rack_saw_enobuf_hw, 1);
18896 				tcp_rl_log_enobuf(rack->r_ctl.crte);
18897 			}
18898 			counter_u64_add(rack_saw_enobuf, 1);
18899 			goto enobufs;
18900 		case EMSGSIZE:
18901 			/*
18902 			 * For some reason the interface we used initially
18903 			 * to send segments changed to another or lowered
18904 			 * its MTU. If TSO was active we either got an
18905 			 * interface without TSO capabilits or TSO was
18906 			 * turned off. If we obtained mtu from ip_output()
18907 			 * then update it and try again.
18908 			 */
18909 			if (tso)
18910 				tp->t_flags &= ~TF_TSO;
18911 			if (mtu != 0) {
18912 				tcp_mss_update(tp, -1, mtu, NULL, NULL);
18913 				goto again;
18914 			}
18915 			slot = 10 * HPTS_USEC_IN_MSEC;
18916 			rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
18917 #ifdef TCP_ACCOUNTING
18918 			crtsc = get_cyclecount();
18919 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18920 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
18921 			}
18922 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
18923 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18924 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
18925 			}
18926 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
18927 			sched_unpin();
18928 #endif
18929 			return (error);
18930 		case ENETUNREACH:
18931 			counter_u64_add(rack_saw_enetunreach, 1);
18932 		case EHOSTDOWN:
18933 		case EHOSTUNREACH:
18934 		case ENETDOWN:
18935 			if (TCPS_HAVERCVDSYN(tp->t_state)) {
18936 				tp->t_softerror = error;
18937 			}
18938 			/* FALLTHROUGH */
18939 		default:
18940 			slot = 10 * HPTS_USEC_IN_MSEC;
18941 			rack_start_hpts_timer(rack, tp, cts, slot, 0, 0);
18942 #ifdef TCP_ACCOUNTING
18943 			crtsc = get_cyclecount();
18944 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18945 				tp->tcp_cnt_counters[SND_OUT_FAIL]++;
18946 			}
18947 			counter_u64_add(tcp_cnt_counters[SND_OUT_FAIL], 1);
18948 			if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
18949 				tp->tcp_proc_time[SND_OUT_FAIL] += (crtsc - ts_val);
18950 			}
18951 			counter_u64_add(tcp_proc_time[SND_OUT_FAIL], (crtsc - ts_val));
18952 			sched_unpin();
18953 #endif
18954 			return (error);
18955 		}
18956 	} else {
18957 		rack->rc_enobuf = 0;
18958 		if (IN_FASTRECOVERY(tp->t_flags) && rsm)
18959 			rack->r_ctl.retran_during_recovery += len;
18960 	}
18961 	KMOD_TCPSTAT_INC(tcps_sndtotal);
18962 
18963 	/*
18964 	 * Data sent (as far as we can tell). If this advertises a larger
18965 	 * window than any other segment, then remember the size of the
18966 	 * advertised window. Any pending ACK has now been sent.
18967 	 */
18968 	if (recwin > 0 && SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv))
18969 		tp->rcv_adv = tp->rcv_nxt + recwin;
18970 
18971 	tp->last_ack_sent = tp->rcv_nxt;
18972 	tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
18973 enobufs:
18974 	if (sendalot) {
18975 		/* Do we need to turn off sendalot? */
18976 		if (rack->r_ctl.rc_pace_max_segs &&
18977 		    (tot_len_this_send >= rack->r_ctl.rc_pace_max_segs)) {
18978 			/* We hit our max. */
18979 			sendalot = 0;
18980 		} else if ((rack->rc_user_set_max_segs) &&
18981 			   (tot_len_this_send >= (rack->rc_user_set_max_segs * segsiz))) {
18982 			/* We hit the user defined max */
18983 			sendalot = 0;
18984 		}
18985 	}
18986 	if ((error == 0) && (flags & TH_FIN))
18987 		tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_FIN);
18988 	if (flags & TH_RST) {
18989 		/*
18990 		 * We don't send again after sending a RST.
18991 		 */
18992 		slot = 0;
18993 		sendalot = 0;
18994 		if (error == 0)
18995 			tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
18996 	} else if ((slot == 0) && (sendalot == 0) && tot_len_this_send) {
18997 		/*
18998 		 * Get our pacing rate, if an error
18999 		 * occurred in sending (ENOBUF) we would
19000 		 * hit the else if with slot preset. Other
19001 		 * errors return.
19002 		 */
19003 		slot = rack_get_pacing_delay(rack, tp, tot_len_this_send, rsm, segsiz);
19004 	}
19005 	if (rsm &&
19006 	    (rsm->r_flags & RACK_HAS_SYN) == 0 &&
19007 	    rack->use_rack_rr) {
19008 		/* Its a retransmit and we use the rack cheat? */
19009 		if ((slot == 0) ||
19010 		    (rack->rc_always_pace == 0) ||
19011 		    (rack->r_rr_config == 1)) {
19012 			/*
19013 			 * We have no pacing set or we
19014 			 * are using old-style rack or
19015 			 * we are overriden to use the old 1ms pacing.
19016 			 */
19017 			slot = rack->r_ctl.rc_min_to;
19018 		}
19019 	}
19020 	/* We have sent clear the flag */
19021 	rack->r_ent_rec_ns = 0;
19022 	if (rack->r_must_retran) {
19023 		if (rsm) {
19024 			rack->r_ctl.rc_out_at_rto -= (rsm->r_end - rsm->r_start);
19025 			if (SEQ_GEQ(rsm->r_end, rack->r_ctl.rc_snd_max_at_rto)) {
19026 				/*
19027 				 * We have retransmitted all.
19028 				 */
19029 				rack->r_must_retran = 0;
19030 				rack->r_ctl.rc_out_at_rto = 0;
19031 			}
19032 		} else if (SEQ_GEQ(tp->snd_max, rack->r_ctl.rc_snd_max_at_rto)) {
19033 			/*
19034 			 * Sending new data will also kill
19035 			 * the loop.
19036 			 */
19037 			rack->r_must_retran = 0;
19038 			rack->r_ctl.rc_out_at_rto = 0;
19039 		}
19040 	}
19041 	rack->r_ctl.fsb.recwin = recwin;
19042 	if ((tp->t_flags & (TF_WASCRECOVERY|TF_WASFRECOVERY)) &&
19043 	    SEQ_GT(tp->snd_max, rack->r_ctl.rc_snd_max_at_rto)) {
19044 		/*
19045 		 * We hit an RTO and now have past snd_max at the RTO
19046 		 * clear all the WAS flags.
19047 		 */
19048 		tp->t_flags &= ~(TF_WASCRECOVERY|TF_WASFRECOVERY);
19049 	}
19050 	if (slot) {
19051 		/* set the rack tcb into the slot N */
19052 		if ((error == 0) &&
19053 		    rack_use_rfo &&
19054 		    ((flags & (TH_SYN|TH_FIN)) == 0) &&
19055 		    (rsm == NULL) &&
19056 		    (tp->snd_nxt == tp->snd_max) &&
19057 		    (ipoptlen == 0) &&
19058 		    (tp->rcv_numsacks == 0) &&
19059 		    rack->r_fsb_inited &&
19060 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
19061 		    (rack->r_must_retran == 0) &&
19062 		    ((tp->t_flags & TF_NEEDFIN) == 0) &&
19063 		    (len > 0) && (orig_len > 0) &&
19064 		    (orig_len > len) &&
19065 		    ((orig_len - len) >= segsiz) &&
19066 		    ((optlen == 0) ||
19067 		     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
19068 			/* We can send at least one more MSS using our fsb */
19069 
19070 			rack->r_fast_output = 1;
19071 			rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
19072 			rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
19073 			rack->r_ctl.fsb.tcp_flags = flags;
19074 			rack->r_ctl.fsb.left_to_send = orig_len - len;
19075 			if (hw_tls)
19076 				rack->r_ctl.fsb.hw_tls = 1;
19077 			else
19078 				rack->r_ctl.fsb.hw_tls = 0;
19079 			KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
19080 				("rack:%p left_to_send:%u sbavail:%u out:%u",
19081 				 rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
19082 				 (tp->snd_max - tp->snd_una)));
19083 			if (rack->r_ctl.fsb.left_to_send < segsiz)
19084 				rack->r_fast_output = 0;
19085 			else {
19086 				if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
19087 					rack->r_ctl.fsb.rfo_apply_push = 1;
19088 				else
19089 					rack->r_ctl.fsb.rfo_apply_push = 0;
19090 			}
19091 		} else
19092 			rack->r_fast_output = 0;
19093 		rack_log_fsb(rack, tp, so, flags,
19094 			     ipoptlen, orig_len, len, error,
19095 			     (rsm == NULL), optlen, __LINE__, 2);
19096 	} else if (sendalot) {
19097 		int ret;
19098 
19099 		sack_rxmit = 0;
19100 		if ((error == 0) &&
19101 		    rack_use_rfo &&
19102 		    ((flags & (TH_SYN|TH_FIN)) == 0) &&
19103 		    (rsm == NULL) &&
19104 		    (ipoptlen == 0) &&
19105 		    (tp->rcv_numsacks == 0) &&
19106 		    (tp->snd_nxt == tp->snd_max) &&
19107 		    (rack->r_must_retran == 0) &&
19108 		    rack->r_fsb_inited &&
19109 		    TCPS_HAVEESTABLISHED(tp->t_state) &&
19110 		    ((tp->t_flags & TF_NEEDFIN) == 0) &&
19111 		    (len > 0) && (orig_len > 0) &&
19112 		    (orig_len > len) &&
19113 		    ((orig_len - len) >= segsiz) &&
19114 		    ((optlen == 0) ||
19115 		     ((optlen == TCPOLEN_TSTAMP_APPA) && (to.to_flags & TOF_TS)))) {
19116 			/* we can use fast_output for more */
19117 
19118 			rack->r_fast_output = 1;
19119 			rack->r_ctl.fsb.m = sbsndmbuf(sb, (tp->snd_max - tp->snd_una), &rack->r_ctl.fsb.off);
19120 			rack->r_ctl.fsb.o_m_len = rack->r_ctl.fsb.m->m_len;
19121 			rack->r_ctl.fsb.tcp_flags = flags;
19122 			rack->r_ctl.fsb.left_to_send = orig_len - len;
19123 			if (hw_tls)
19124 				rack->r_ctl.fsb.hw_tls = 1;
19125 			else
19126 				rack->r_ctl.fsb.hw_tls = 0;
19127 			KASSERT((rack->r_ctl.fsb.left_to_send <= (sbavail(sb) - (tp->snd_max - tp->snd_una))),
19128 				("rack:%p left_to_send:%u sbavail:%u out:%u",
19129 				 rack, rack->r_ctl.fsb.left_to_send, sbavail(sb),
19130 				 (tp->snd_max - tp->snd_una)));
19131 			if (rack->r_ctl.fsb.left_to_send < segsiz) {
19132 				rack->r_fast_output = 0;
19133 			}
19134 			if (rack->r_fast_output) {
19135 				if (rack->r_ctl.fsb.left_to_send == (sbavail(sb) - (tp->snd_max - tp->snd_una)))
19136 					rack->r_ctl.fsb.rfo_apply_push = 1;
19137 				else
19138 					rack->r_ctl.fsb.rfo_apply_push = 0;
19139 				rack_log_fsb(rack, tp, so, flags,
19140 					     ipoptlen, orig_len, len, error,
19141 					     (rsm == NULL), optlen, __LINE__, 3);
19142 				error = 0;
19143 				ret = rack_fast_output(tp, rack, ts_val, cts, ms_cts, &tv, tot_len_this_send, &error);
19144 				if (ret >= 0)
19145 					return (ret);
19146 			        else if (error)
19147 					goto nomore;
19148 
19149 			}
19150 		}
19151 		goto again;
19152 	}
19153 	/* Assure when we leave that snd_nxt will point to top */
19154 	if (SEQ_GT(tp->snd_max, tp->snd_nxt))
19155 		tp->snd_nxt = tp->snd_max;
19156 	rack_start_hpts_timer(rack, tp, cts, slot, tot_len_this_send, 0);
19157 #ifdef TCP_ACCOUNTING
19158 	crtsc = get_cyclecount() - ts_val;
19159 	if (tot_len_this_send) {
19160 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19161 			tp->tcp_cnt_counters[SND_OUT_DATA]++;
19162 		}
19163 		counter_u64_add(tcp_cnt_counters[SND_OUT_DATA], 1);
19164 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19165 			tp->tcp_proc_time[SND_OUT_DATA] += crtsc;
19166 		}
19167 		counter_u64_add(tcp_proc_time[SND_OUT_DATA], crtsc);
19168 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19169 			tp->tcp_cnt_counters[CNT_OF_MSS_OUT] += ((tot_len_this_send + segsiz - 1) /segsiz);
19170 		}
19171 		counter_u64_add(tcp_cnt_counters[CNT_OF_MSS_OUT], ((tot_len_this_send + segsiz - 1) /segsiz));
19172 	} else {
19173 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19174 			tp->tcp_cnt_counters[SND_OUT_ACK]++;
19175 		}
19176 		counter_u64_add(tcp_cnt_counters[SND_OUT_ACK], 1);
19177 		if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
19178 			tp->tcp_proc_time[SND_OUT_ACK] += crtsc;
19179 		}
19180 		counter_u64_add(tcp_proc_time[SND_OUT_ACK], crtsc);
19181 	}
19182 	sched_unpin();
19183 #endif
19184 	if (error == ENOBUFS)
19185 		error = 0;
19186 	return (error);
19187 }
19188 
19189 static void
19190 rack_update_seg(struct tcp_rack *rack)
19191 {
19192 	uint32_t orig_val;
19193 
19194 	orig_val = rack->r_ctl.rc_pace_max_segs;
19195 	rack_set_pace_segments(rack->rc_tp, rack, __LINE__, NULL);
19196 	if (orig_val != rack->r_ctl.rc_pace_max_segs)
19197 		rack_log_pacing_delay_calc(rack, 0, 0, orig_val, 0, 0, 15, __LINE__, NULL, 0);
19198 }
19199 
19200 static void
19201 rack_mtu_change(struct tcpcb *tp)
19202 {
19203 	/*
19204 	 * The MSS may have changed
19205 	 */
19206 	struct tcp_rack *rack;
19207 	struct rack_sendmap *rsm;
19208 
19209 	rack = (struct tcp_rack *)tp->t_fb_ptr;
19210 	if (rack->r_ctl.rc_pace_min_segs != ctf_fixed_maxseg(tp)) {
19211 		/*
19212 		 * The MTU has changed we need to resend everything
19213 		 * since all we have sent is lost. We first fix
19214 		 * up the mtu though.
19215 		 */
19216 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
19217 		/* We treat this like a full retransmit timeout without the cwnd adjustment */
19218 		rack_remxt_tmr(tp);
19219 		rack->r_fast_output = 0;
19220 		rack->r_ctl.rc_out_at_rto = ctf_flight_size(tp,
19221 						rack->r_ctl.rc_sacked);
19222 		rack->r_ctl.rc_snd_max_at_rto = tp->snd_max;
19223 		rack->r_must_retran = 1;
19224 		/* Mark all inflight to needing to be rxt'd */
19225 		TAILQ_FOREACH(rsm, &rack->r_ctl.rc_tmap, r_tnext) {
19226 			rsm->r_flags |= RACK_MUST_RXT;
19227 		}
19228 	}
19229 	sack_filter_clear(&rack->r_ctl.rack_sf, tp->snd_una);
19230 	/* We don't use snd_nxt to retransmit */
19231 	tp->snd_nxt = tp->snd_max;
19232 }
19233 
19234 static int
19235 rack_set_profile(struct tcp_rack *rack, int prof)
19236 {
19237 	int err = EINVAL;
19238 	if (prof == 1) {
19239 		/* pace_always=1 */
19240 		if (rack->rc_always_pace == 0) {
19241 			if (tcp_can_enable_pacing() == 0)
19242 				return (EBUSY);
19243 		}
19244 		rack->rc_always_pace = 1;
19245 		if (rack->use_fixed_rate || rack->gp_ready)
19246 			rack_set_cc_pacing(rack);
19247 		rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19248 		rack->rack_attempt_hdwr_pace = 0;
19249 		/* cmpack=1 */
19250 		if (rack_use_cmp_acks)
19251 			rack->r_use_cmp_ack = 1;
19252 		if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state) &&
19253 		    rack->r_use_cmp_ack)
19254 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19255 		/* scwnd=1 */
19256 		rack->rack_enable_scwnd = 1;
19257 		/* dynamic=100 */
19258 		rack->rc_gp_dyn_mul = 1;
19259 		/* gp_inc_ca */
19260 		rack->r_ctl.rack_per_of_gp_ca = 100;
19261 		/* rrr_conf=3 */
19262 		rack->r_rr_config = 3;
19263 		/* npush=2 */
19264 		rack->r_ctl.rc_no_push_at_mrtt = 2;
19265 		/* fillcw=1 */
19266 		rack->rc_pace_to_cwnd = 1;
19267 		rack->rc_pace_fill_if_rttin_range = 0;
19268 		rack->rtt_limit_mul = 0;
19269 		/* noprr=1 */
19270 		rack->rack_no_prr = 1;
19271 		/* lscwnd=1 */
19272 		rack->r_limit_scw = 1;
19273 		/* gp_inc_rec */
19274 		rack->r_ctl.rack_per_of_gp_rec = 90;
19275 		err = 0;
19276 
19277 	} else if (prof == 3) {
19278 		/* Same as profile one execept fill_cw becomes 2 (less aggressive set) */
19279 		/* pace_always=1 */
19280 		if (rack->rc_always_pace == 0) {
19281 			if (tcp_can_enable_pacing() == 0)
19282 				return (EBUSY);
19283 		}
19284 		rack->rc_always_pace = 1;
19285 		if (rack->use_fixed_rate || rack->gp_ready)
19286 			rack_set_cc_pacing(rack);
19287 		rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19288 		rack->rack_attempt_hdwr_pace = 0;
19289 		/* cmpack=1 */
19290 		if (rack_use_cmp_acks)
19291 			rack->r_use_cmp_ack = 1;
19292 		if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state) &&
19293 		    rack->r_use_cmp_ack)
19294 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19295 		/* scwnd=1 */
19296 		rack->rack_enable_scwnd = 1;
19297 		/* dynamic=100 */
19298 		rack->rc_gp_dyn_mul = 1;
19299 		/* gp_inc_ca */
19300 		rack->r_ctl.rack_per_of_gp_ca = 100;
19301 		/* rrr_conf=3 */
19302 		rack->r_rr_config = 3;
19303 		/* npush=2 */
19304 		rack->r_ctl.rc_no_push_at_mrtt = 2;
19305 		/* fillcw=2 */
19306 		rack->rc_pace_to_cwnd = 1;
19307 		rack->r_fill_less_agg = 1;
19308 		rack->rc_pace_fill_if_rttin_range = 0;
19309 		rack->rtt_limit_mul = 0;
19310 		/* noprr=1 */
19311 		rack->rack_no_prr = 1;
19312 		/* lscwnd=1 */
19313 		rack->r_limit_scw = 1;
19314 		/* gp_inc_rec */
19315 		rack->r_ctl.rack_per_of_gp_rec = 90;
19316 		err = 0;
19317 
19318 
19319 	} else if (prof == 2) {
19320 		/* cmpack=1 */
19321 		if (rack->rc_always_pace == 0) {
19322 			if (tcp_can_enable_pacing() == 0)
19323 				return (EBUSY);
19324 		}
19325 		rack->rc_always_pace = 1;
19326 		if (rack->use_fixed_rate || rack->gp_ready)
19327 			rack_set_cc_pacing(rack);
19328 		rack->r_use_cmp_ack = 1;
19329 		if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state))
19330 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19331 		/* pace_always=1 */
19332 		rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19333 		/* scwnd=1 */
19334 		rack->rack_enable_scwnd = 1;
19335 		/* dynamic=100 */
19336 		rack->rc_gp_dyn_mul = 1;
19337 		rack->r_ctl.rack_per_of_gp_ca = 100;
19338 		/* rrr_conf=3 */
19339 		rack->r_rr_config = 3;
19340 		/* npush=2 */
19341 		rack->r_ctl.rc_no_push_at_mrtt = 2;
19342 		/* fillcw=1 */
19343 		rack->rc_pace_to_cwnd = 1;
19344 		rack->rc_pace_fill_if_rttin_range = 0;
19345 		rack->rtt_limit_mul = 0;
19346 		/* noprr=1 */
19347 		rack->rack_no_prr = 1;
19348 		/* lscwnd=0 */
19349 		rack->r_limit_scw = 0;
19350 		err = 0;
19351 	} else if (prof == 0) {
19352 		/* This changes things back to the default settings */
19353 		err = 0;
19354 		if (rack->rc_always_pace) {
19355 			tcp_decrement_paced_conn();
19356 			rack_undo_cc_pacing(rack);
19357 			rack->rc_always_pace = 0;
19358 		}
19359 		if (rack_pace_every_seg && tcp_can_enable_pacing()) {
19360 			rack->rc_always_pace = 1;
19361 			if (rack->use_fixed_rate || rack->gp_ready)
19362 				rack_set_cc_pacing(rack);
19363 		} else
19364 			rack->rc_always_pace = 0;
19365 		if (rack_dsack_std_based & 0x1) {
19366 			/* Basically this means all rack timers are at least (srtt + 1/4 srtt) */
19367 			rack->rc_rack_tmr_std_based = 1;
19368 		}
19369 		if (rack_dsack_std_based & 0x2) {
19370 			/* Basically this means  rack timers are extended based on dsack by up to (2 * srtt) */
19371 			rack->rc_rack_use_dsack = 1;
19372 		}
19373 		if (rack_use_cmp_acks)
19374 			rack->r_use_cmp_ack = 1;
19375 		else
19376 			rack->r_use_cmp_ack = 0;
19377 		if (rack_disable_prr)
19378 			rack->rack_no_prr = 1;
19379 		else
19380 			rack->rack_no_prr = 0;
19381 		if (rack_gp_no_rec_chg)
19382 			rack->rc_gp_no_rec_chg = 1;
19383 		else
19384 			rack->rc_gp_no_rec_chg = 0;
19385 		if (rack_enable_mqueue_for_nonpaced || rack->r_use_cmp_ack) {
19386 			rack->r_mbuf_queue = 1;
19387 			if (TCPS_HAVEESTABLISHED(rack->rc_tp->t_state))
19388 				rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19389 			rack->rc_inp->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19390 		} else {
19391 			rack->r_mbuf_queue = 0;
19392 			rack->rc_inp->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
19393 		}
19394 		if (rack_enable_shared_cwnd)
19395 			rack->rack_enable_scwnd = 1;
19396 		else
19397 			rack->rack_enable_scwnd = 0;
19398 		if (rack_do_dyn_mul) {
19399 			/* When dynamic adjustment is on CA needs to start at 100% */
19400 			rack->rc_gp_dyn_mul = 1;
19401 			if (rack_do_dyn_mul >= 100)
19402 				rack->r_ctl.rack_per_of_gp_ca = rack_do_dyn_mul;
19403 		} else {
19404 			rack->r_ctl.rack_per_of_gp_ca = rack_per_of_gp_ca;
19405 			rack->rc_gp_dyn_mul = 0;
19406 		}
19407 		rack->r_rr_config = 0;
19408 		rack->r_ctl.rc_no_push_at_mrtt = 0;
19409 		rack->rc_pace_to_cwnd = 0;
19410 		rack->rc_pace_fill_if_rttin_range = 0;
19411 		rack->rtt_limit_mul = 0;
19412 
19413 		if (rack_enable_hw_pacing)
19414 			rack->rack_hdw_pace_ena = 1;
19415 		else
19416 			rack->rack_hdw_pace_ena = 0;
19417 		if (rack_disable_prr)
19418 			rack->rack_no_prr = 1;
19419 		else
19420 			rack->rack_no_prr = 0;
19421 		if (rack_limits_scwnd)
19422 			rack->r_limit_scw  = 1;
19423 		else
19424 			rack->r_limit_scw  = 0;
19425 		err = 0;
19426 	}
19427 	return (err);
19428 }
19429 
19430 static int
19431 rack_add_deferred_option(struct tcp_rack *rack, int sopt_name, uint64_t loptval)
19432 {
19433 	struct deferred_opt_list *dol;
19434 
19435 	dol = malloc(sizeof(struct deferred_opt_list),
19436 		     M_TCPFSB, M_NOWAIT|M_ZERO);
19437 	if (dol == NULL) {
19438 		/*
19439 		 * No space yikes -- fail out..
19440 		 */
19441 		return (0);
19442 	}
19443 	dol->optname = sopt_name;
19444 	dol->optval = loptval;
19445 	TAILQ_INSERT_TAIL(&rack->r_ctl.opt_list, dol, next);
19446 	return (1);
19447 }
19448 
19449 static int
19450 rack_process_option(struct tcpcb *tp, struct tcp_rack *rack, int sopt_name,
19451 		    uint32_t optval, uint64_t loptval)
19452 {
19453 	struct epoch_tracker et;
19454 	struct sockopt sopt;
19455 	struct cc_newreno_opts opt;
19456 	uint64_t val;
19457 	int error = 0;
19458 	uint16_t ca, ss;
19459 
19460 	switch (sopt_name) {
19461 
19462 	case TCP_RACK_DSACK_OPT:
19463 		RACK_OPTS_INC(tcp_rack_dsack_opt);
19464 		if (optval & 0x1) {
19465 			rack->rc_rack_tmr_std_based = 1;
19466 		} else {
19467 			rack->rc_rack_tmr_std_based = 0;
19468 		}
19469 		if (optval & 0x2) {
19470 			rack->rc_rack_use_dsack = 1;
19471 		} else {
19472 			rack->rc_rack_use_dsack = 0;
19473 		}
19474 		rack_log_dsack_event(rack, 5, __LINE__, 0, 0);
19475 		break;
19476 	case TCP_RACK_PACING_BETA:
19477 		RACK_OPTS_INC(tcp_rack_beta);
19478 		if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0) {
19479 			/* This only works for newreno. */
19480 			error = EINVAL;
19481 			break;
19482 		}
19483 		if (rack->rc_pacing_cc_set) {
19484 			/*
19485 			 * Set them into the real CC module
19486 			 * whats in the rack pcb is the old values
19487 			 * to be used on restoral/
19488 			 */
19489 			sopt.sopt_dir = SOPT_SET;
19490 			opt.name = CC_NEWRENO_BETA;
19491 			opt.val = optval;
19492 			if (CC_ALGO(tp)->ctl_output != NULL)
19493 				error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
19494 			else {
19495 				error = ENOENT;
19496 				break;
19497 			}
19498 		} else {
19499 			/*
19500 			 * Not pacing yet so set it into our local
19501 			 * rack pcb storage.
19502 			 */
19503 			rack->r_ctl.rc_saved_beta.beta = optval;
19504 		}
19505 		break;
19506 	case TCP_RACK_TIMER_SLOP:
19507 		RACK_OPTS_INC(tcp_rack_timer_slop);
19508 		rack->r_ctl.timer_slop = optval;
19509 		if (rack->rc_tp->t_srtt) {
19510 			/*
19511 			 * If we have an SRTT lets update t_rxtcur
19512 			 * to have the new slop.
19513 			 */
19514 			RACK_TCPT_RANGESET(tp->t_rxtcur, RACK_REXMTVAL(tp),
19515 					   rack_rto_min, rack_rto_max,
19516 					   rack->r_ctl.timer_slop);
19517 		}
19518 		break;
19519 	case TCP_RACK_PACING_BETA_ECN:
19520 		RACK_OPTS_INC(tcp_rack_beta_ecn);
19521 		if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0) {
19522 			/* This only works for newreno. */
19523 			error = EINVAL;
19524 			break;
19525 		}
19526 		if (rack->rc_pacing_cc_set) {
19527 			/*
19528 			 * Set them into the real CC module
19529 			 * whats in the rack pcb is the old values
19530 			 * to be used on restoral/
19531 			 */
19532 			sopt.sopt_dir = SOPT_SET;
19533 			opt.name = CC_NEWRENO_BETA_ECN;
19534 			opt.val = optval;
19535 			if (CC_ALGO(tp)->ctl_output != NULL)
19536 				error = CC_ALGO(tp)->ctl_output(tp->ccv, &sopt, &opt);
19537 			else
19538 				error = ENOENT;
19539 		} else {
19540 			/*
19541 			 * Not pacing yet so set it into our local
19542 			 * rack pcb storage.
19543 			 */
19544 			rack->r_ctl.rc_saved_beta.beta_ecn = optval;
19545 			rack->r_ctl.rc_saved_beta.newreno_flags = CC_NEWRENO_BETA_ECN_ENABLED;
19546 		}
19547 		break;
19548 	case TCP_DEFER_OPTIONS:
19549 		RACK_OPTS_INC(tcp_defer_opt);
19550 		if (optval) {
19551 			if (rack->gp_ready) {
19552 				/* Too late */
19553 				error = EINVAL;
19554 				break;
19555 			}
19556 			rack->defer_options = 1;
19557 		} else
19558 			rack->defer_options = 0;
19559 		break;
19560 	case TCP_RACK_MEASURE_CNT:
19561 		RACK_OPTS_INC(tcp_rack_measure_cnt);
19562 		if (optval && (optval <= 0xff)) {
19563 			rack->r_ctl.req_measurements = optval;
19564 		} else
19565 			error = EINVAL;
19566 		break;
19567 	case TCP_REC_ABC_VAL:
19568 		RACK_OPTS_INC(tcp_rec_abc_val);
19569 		if (optval > 0)
19570 			rack->r_use_labc_for_rec = 1;
19571 		else
19572 			rack->r_use_labc_for_rec = 0;
19573 		break;
19574 	case TCP_RACK_ABC_VAL:
19575 		RACK_OPTS_INC(tcp_rack_abc_val);
19576 		if ((optval > 0) && (optval < 255))
19577 			rack->rc_labc = optval;
19578 		else
19579 			error = EINVAL;
19580 		break;
19581 	case TCP_HDWR_UP_ONLY:
19582 		RACK_OPTS_INC(tcp_pacing_up_only);
19583 		if (optval)
19584 			rack->r_up_only = 1;
19585 		else
19586 			rack->r_up_only = 0;
19587 		break;
19588 	case TCP_PACING_RATE_CAP:
19589 		RACK_OPTS_INC(tcp_pacing_rate_cap);
19590 		rack->r_ctl.bw_rate_cap = loptval;
19591 		break;
19592 	case TCP_RACK_PROFILE:
19593 		RACK_OPTS_INC(tcp_profile);
19594 		error = rack_set_profile(rack, optval);
19595 		break;
19596 	case TCP_USE_CMP_ACKS:
19597 		RACK_OPTS_INC(tcp_use_cmp_acks);
19598 		if ((optval == 0) && (rack->rc_inp->inp_flags2 & INP_MBUF_ACKCMP)) {
19599 			/* You can't turn it off once its on! */
19600 			error = EINVAL;
19601 		} else if ((optval == 1) && (rack->r_use_cmp_ack == 0)) {
19602 			rack->r_use_cmp_ack = 1;
19603 			rack->r_mbuf_queue = 1;
19604 			tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19605 		}
19606 		if (rack->r_use_cmp_ack && TCPS_HAVEESTABLISHED(tp->t_state))
19607 			rack->rc_inp->inp_flags2 |= INP_MBUF_ACKCMP;
19608 		break;
19609 	case TCP_SHARED_CWND_TIME_LIMIT:
19610 		RACK_OPTS_INC(tcp_lscwnd);
19611 		if (optval)
19612 			rack->r_limit_scw = 1;
19613 		else
19614 			rack->r_limit_scw = 0;
19615 		break;
19616  	case TCP_RACK_PACE_TO_FILL:
19617 		RACK_OPTS_INC(tcp_fillcw);
19618 		if (optval == 0)
19619 			rack->rc_pace_to_cwnd = 0;
19620 		else {
19621 			rack->rc_pace_to_cwnd = 1;
19622 			if (optval > 1)
19623 				rack->r_fill_less_agg = 1;
19624 		}
19625 		if ((optval >= rack_gp_rtt_maxmul) &&
19626 		    rack_gp_rtt_maxmul &&
19627 		    (optval < 0xf)) {
19628 			rack->rc_pace_fill_if_rttin_range = 1;
19629 			rack->rtt_limit_mul = optval;
19630 		} else {
19631 			rack->rc_pace_fill_if_rttin_range = 0;
19632 			rack->rtt_limit_mul = 0;
19633 		}
19634 		break;
19635 	case TCP_RACK_NO_PUSH_AT_MAX:
19636 		RACK_OPTS_INC(tcp_npush);
19637 		if (optval == 0)
19638 			rack->r_ctl.rc_no_push_at_mrtt = 0;
19639 		else if (optval < 0xff)
19640 			rack->r_ctl.rc_no_push_at_mrtt = optval;
19641 		else
19642 			error = EINVAL;
19643 		break;
19644 	case TCP_SHARED_CWND_ENABLE:
19645 		RACK_OPTS_INC(tcp_rack_scwnd);
19646 		if (optval == 0)
19647 			rack->rack_enable_scwnd = 0;
19648 		else
19649 			rack->rack_enable_scwnd = 1;
19650 		break;
19651 	case TCP_RACK_MBUF_QUEUE:
19652 		/* Now do we use the LRO mbuf-queue feature */
19653 		RACK_OPTS_INC(tcp_rack_mbufq);
19654 		if (optval || rack->r_use_cmp_ack)
19655 			rack->r_mbuf_queue = 1;
19656 		else
19657 			rack->r_mbuf_queue = 0;
19658 		if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
19659 			tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19660 		else
19661 			tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
19662 		break;
19663 	case TCP_RACK_NONRXT_CFG_RATE:
19664 		RACK_OPTS_INC(tcp_rack_cfg_rate);
19665 		if (optval == 0)
19666 			rack->rack_rec_nonrxt_use_cr = 0;
19667 		else
19668 			rack->rack_rec_nonrxt_use_cr = 1;
19669 		break;
19670 	case TCP_NO_PRR:
19671 		RACK_OPTS_INC(tcp_rack_noprr);
19672 		if (optval == 0)
19673 			rack->rack_no_prr = 0;
19674 		else if (optval == 1)
19675 			rack->rack_no_prr = 1;
19676 		else if (optval == 2)
19677 			rack->no_prr_addback = 1;
19678 		else
19679 			error = EINVAL;
19680 		break;
19681 	case TCP_TIMELY_DYN_ADJ:
19682 		RACK_OPTS_INC(tcp_timely_dyn);
19683 		if (optval == 0)
19684 			rack->rc_gp_dyn_mul = 0;
19685 		else {
19686 			rack->rc_gp_dyn_mul = 1;
19687 			if (optval >= 100) {
19688 				/*
19689 				 * If the user sets something 100 or more
19690 				 * its the gp_ca value.
19691 				 */
19692 				rack->r_ctl.rack_per_of_gp_ca  = optval;
19693 			}
19694 		}
19695 		break;
19696 	case TCP_RACK_DO_DETECTION:
19697 		RACK_OPTS_INC(tcp_rack_do_detection);
19698 		if (optval == 0)
19699 			rack->do_detection = 0;
19700 		else
19701 			rack->do_detection = 1;
19702 		break;
19703 	case TCP_RACK_TLP_USE:
19704 		if ((optval < TLP_USE_ID) || (optval > TLP_USE_TWO_TWO)) {
19705 			error = EINVAL;
19706 			break;
19707 		}
19708 		RACK_OPTS_INC(tcp_tlp_use);
19709 		rack->rack_tlp_threshold_use = optval;
19710 		break;
19711 	case TCP_RACK_TLP_REDUCE:
19712 		/* RACK TLP cwnd reduction (bool) */
19713 		RACK_OPTS_INC(tcp_rack_tlp_reduce);
19714 		rack->r_ctl.rc_tlp_cwnd_reduce = optval;
19715 		break;
19716 	/*  Pacing related ones */
19717 	case TCP_RACK_PACE_ALWAYS:
19718 		/*
19719 		 * zero is old rack method, 1 is new
19720 		 * method using a pacing rate.
19721 		 */
19722 		RACK_OPTS_INC(tcp_rack_pace_always);
19723 		if (optval > 0) {
19724 			if (rack->rc_always_pace) {
19725 				error = EALREADY;
19726 				break;
19727 			} else if (tcp_can_enable_pacing()) {
19728 				rack->rc_always_pace = 1;
19729 				if (rack->use_fixed_rate || rack->gp_ready)
19730 					rack_set_cc_pacing(rack);
19731 			}
19732 			else {
19733 				error = ENOSPC;
19734 				break;
19735 			}
19736 		} else {
19737 			if (rack->rc_always_pace) {
19738 				tcp_decrement_paced_conn();
19739 				rack->rc_always_pace = 0;
19740 				rack_undo_cc_pacing(rack);
19741 			}
19742 		}
19743 		if  (rack->r_mbuf_queue || rack->rc_always_pace || rack->r_use_cmp_ack)
19744 			tp->t_inpcb->inp_flags2 |= INP_SUPPORTS_MBUFQ;
19745 		else
19746 			tp->t_inpcb->inp_flags2 &= ~INP_SUPPORTS_MBUFQ;
19747 		/* A rate may be set irate or other, if so set seg size */
19748 		rack_update_seg(rack);
19749 		break;
19750 	case TCP_BBR_RACK_INIT_RATE:
19751 		RACK_OPTS_INC(tcp_initial_rate);
19752 		val = optval;
19753 		/* Change from kbits per second to bytes per second */
19754 		val *= 1000;
19755 		val /= 8;
19756 		rack->r_ctl.init_rate = val;
19757 		if (rack->rc_init_win != rack_default_init_window) {
19758 			uint32_t win, snt;
19759 
19760 			/*
19761 			 * Options don't always get applied
19762 			 * in the order you think. So in order
19763 			 * to assure we update a cwnd we need
19764 			 * to check and see if we are still
19765 			 * where we should raise the cwnd.
19766 			 */
19767 			win = rc_init_window(rack);
19768 			if (SEQ_GT(tp->snd_max, tp->iss))
19769 				snt = tp->snd_max - tp->iss;
19770 			else
19771 				snt = 0;
19772 			if ((snt < win) &&
19773 			    (tp->snd_cwnd < win))
19774 				tp->snd_cwnd = win;
19775 		}
19776 		if (rack->rc_always_pace)
19777 			rack_update_seg(rack);
19778 		break;
19779 	case TCP_BBR_IWINTSO:
19780 		RACK_OPTS_INC(tcp_initial_win);
19781 		if (optval && (optval <= 0xff)) {
19782 			uint32_t win, snt;
19783 
19784 			rack->rc_init_win = optval;
19785 			win = rc_init_window(rack);
19786 			if (SEQ_GT(tp->snd_max, tp->iss))
19787 				snt = tp->snd_max - tp->iss;
19788 			else
19789 				snt = 0;
19790 			if ((snt < win) &&
19791 			    (tp->t_srtt |
19792 #ifdef NETFLIX_PEAKRATE
19793 			     tp->t_maxpeakrate |
19794 #endif
19795 			     rack->r_ctl.init_rate)) {
19796 				/*
19797 				 * We are not past the initial window
19798 				 * and we have some bases for pacing,
19799 				 * so we need to possibly adjust up
19800 				 * the cwnd. Note even if we don't set
19801 				 * the cwnd, its still ok to raise the rc_init_win
19802 				 * which can be used coming out of idle when we
19803 				 * would have a rate.
19804 				 */
19805 				if (tp->snd_cwnd < win)
19806 					tp->snd_cwnd = win;
19807 			}
19808 			if (rack->rc_always_pace)
19809 				rack_update_seg(rack);
19810 		} else
19811 			error = EINVAL;
19812 		break;
19813 	case TCP_RACK_FORCE_MSEG:
19814 		RACK_OPTS_INC(tcp_rack_force_max_seg);
19815 		if (optval)
19816 			rack->rc_force_max_seg = 1;
19817 		else
19818 			rack->rc_force_max_seg = 0;
19819 		break;
19820 	case TCP_RACK_PACE_MAX_SEG:
19821 		/* Max segments size in a pace in bytes */
19822 		RACK_OPTS_INC(tcp_rack_max_seg);
19823 		rack->rc_user_set_max_segs = optval;
19824 		rack_set_pace_segments(tp, rack, __LINE__, NULL);
19825 		break;
19826 	case TCP_RACK_PACE_RATE_REC:
19827 		/* Set the fixed pacing rate in Bytes per second ca */
19828 		RACK_OPTS_INC(tcp_rack_pace_rate_rec);
19829 		rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
19830 		if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
19831 			rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
19832 		if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
19833 			rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
19834 		rack->use_fixed_rate = 1;
19835 		if (rack->rc_always_pace)
19836 			rack_set_cc_pacing(rack);
19837 		rack_log_pacing_delay_calc(rack,
19838 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
19839 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
19840 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
19841 					   __LINE__, NULL,0);
19842 		break;
19843 
19844 	case TCP_RACK_PACE_RATE_SS:
19845 		/* Set the fixed pacing rate in Bytes per second ca */
19846 		RACK_OPTS_INC(tcp_rack_pace_rate_ss);
19847 		rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
19848 		if (rack->r_ctl.rc_fixed_pacing_rate_ca == 0)
19849 			rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
19850 		if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
19851 			rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
19852 		rack->use_fixed_rate = 1;
19853 		if (rack->rc_always_pace)
19854 			rack_set_cc_pacing(rack);
19855 		rack_log_pacing_delay_calc(rack,
19856 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
19857 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
19858 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
19859 					   __LINE__, NULL, 0);
19860 		break;
19861 
19862 	case TCP_RACK_PACE_RATE_CA:
19863 		/* Set the fixed pacing rate in Bytes per second ca */
19864 		RACK_OPTS_INC(tcp_rack_pace_rate_ca);
19865 		rack->r_ctl.rc_fixed_pacing_rate_ca = optval;
19866 		if (rack->r_ctl.rc_fixed_pacing_rate_ss == 0)
19867 			rack->r_ctl.rc_fixed_pacing_rate_ss = optval;
19868 		if (rack->r_ctl.rc_fixed_pacing_rate_rec == 0)
19869 			rack->r_ctl.rc_fixed_pacing_rate_rec = optval;
19870 		rack->use_fixed_rate = 1;
19871 		if (rack->rc_always_pace)
19872 			rack_set_cc_pacing(rack);
19873 		rack_log_pacing_delay_calc(rack,
19874 					   rack->r_ctl.rc_fixed_pacing_rate_ss,
19875 					   rack->r_ctl.rc_fixed_pacing_rate_ca,
19876 					   rack->r_ctl.rc_fixed_pacing_rate_rec, 0, 0, 8,
19877 					   __LINE__, NULL, 0);
19878 		break;
19879 	case TCP_RACK_GP_INCREASE_REC:
19880 		RACK_OPTS_INC(tcp_gp_inc_rec);
19881 		rack->r_ctl.rack_per_of_gp_rec = optval;
19882 		rack_log_pacing_delay_calc(rack,
19883 					   rack->r_ctl.rack_per_of_gp_ss,
19884 					   rack->r_ctl.rack_per_of_gp_ca,
19885 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
19886 					   __LINE__, NULL, 0);
19887 		break;
19888 	case TCP_RACK_GP_INCREASE_CA:
19889 		RACK_OPTS_INC(tcp_gp_inc_ca);
19890 		ca = optval;
19891 		if (ca < 100) {
19892 			/*
19893 			 * We don't allow any reduction
19894 			 * over the GP b/w.
19895 			 */
19896 			error = EINVAL;
19897 			break;
19898 		}
19899 		rack->r_ctl.rack_per_of_gp_ca = ca;
19900 		rack_log_pacing_delay_calc(rack,
19901 					   rack->r_ctl.rack_per_of_gp_ss,
19902 					   rack->r_ctl.rack_per_of_gp_ca,
19903 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
19904 					   __LINE__, NULL, 0);
19905 		break;
19906 	case TCP_RACK_GP_INCREASE_SS:
19907 		RACK_OPTS_INC(tcp_gp_inc_ss);
19908 		ss = optval;
19909 		if (ss < 100) {
19910 			/*
19911 			 * We don't allow any reduction
19912 			 * over the GP b/w.
19913 			 */
19914 			error = EINVAL;
19915 			break;
19916 		}
19917 		rack->r_ctl.rack_per_of_gp_ss = ss;
19918 		rack_log_pacing_delay_calc(rack,
19919 					   rack->r_ctl.rack_per_of_gp_ss,
19920 					   rack->r_ctl.rack_per_of_gp_ca,
19921 					   rack->r_ctl.rack_per_of_gp_rec, 0, 0, 1,
19922 					   __LINE__, NULL, 0);
19923 		break;
19924 	case TCP_RACK_RR_CONF:
19925 		RACK_OPTS_INC(tcp_rack_rrr_no_conf_rate);
19926 		if (optval && optval <= 3)
19927 			rack->r_rr_config = optval;
19928 		else
19929 			rack->r_rr_config = 0;
19930 		break;
19931 	case TCP_HDWR_RATE_CAP:
19932 		RACK_OPTS_INC(tcp_hdwr_rate_cap);
19933 		if (optval) {
19934 			if (rack->r_rack_hw_rate_caps == 0)
19935 				rack->r_rack_hw_rate_caps = 1;
19936 			else
19937 				error = EALREADY;
19938 		} else {
19939 			rack->r_rack_hw_rate_caps = 0;
19940 		}
19941 		break;
19942 	case TCP_BBR_HDWR_PACE:
19943 		RACK_OPTS_INC(tcp_hdwr_pacing);
19944 		if (optval){
19945 			if (rack->rack_hdrw_pacing == 0) {
19946 				rack->rack_hdw_pace_ena = 1;
19947 				rack->rack_attempt_hdwr_pace = 0;
19948 			} else
19949 				error = EALREADY;
19950 		} else {
19951 			rack->rack_hdw_pace_ena = 0;
19952 #ifdef RATELIMIT
19953 			if (rack->r_ctl.crte != NULL) {
19954 				rack->rack_hdrw_pacing = 0;
19955 				rack->rack_attempt_hdwr_pace = 0;
19956 				tcp_rel_pacing_rate(rack->r_ctl.crte, tp);
19957 				rack->r_ctl.crte = NULL;
19958 			}
19959 #endif
19960 		}
19961 		break;
19962 	/*  End Pacing related ones */
19963 	case TCP_RACK_PRR_SENDALOT:
19964 		/* Allow PRR to send more than one seg */
19965 		RACK_OPTS_INC(tcp_rack_prr_sendalot);
19966 		rack->r_ctl.rc_prr_sendalot = optval;
19967 		break;
19968 	case TCP_RACK_MIN_TO:
19969 		/* Minimum time between rack t-o's in ms */
19970 		RACK_OPTS_INC(tcp_rack_min_to);
19971 		rack->r_ctl.rc_min_to = optval;
19972 		break;
19973 	case TCP_RACK_EARLY_SEG:
19974 		/* If early recovery max segments */
19975 		RACK_OPTS_INC(tcp_rack_early_seg);
19976 		rack->r_ctl.rc_early_recovery_segs = optval;
19977 		break;
19978 	case TCP_RACK_ENABLE_HYSTART:
19979 	{
19980 		if (optval) {
19981 			tp->ccv->flags |= CCF_HYSTART_ALLOWED;
19982 			if (rack_do_hystart > RACK_HYSTART_ON)
19983 				tp->ccv->flags |= CCF_HYSTART_CAN_SH_CWND;
19984 			if (rack_do_hystart > RACK_HYSTART_ON_W_SC)
19985 				tp->ccv->flags |= CCF_HYSTART_CONS_SSTH;
19986 		} else {
19987 			tp->ccv->flags &= ~(CCF_HYSTART_ALLOWED|CCF_HYSTART_CAN_SH_CWND|CCF_HYSTART_CONS_SSTH);
19988 		}
19989 	}
19990 	break;
19991 	case TCP_RACK_REORD_THRESH:
19992 		/* RACK reorder threshold (shift amount) */
19993 		RACK_OPTS_INC(tcp_rack_reord_thresh);
19994 		if ((optval > 0) && (optval < 31))
19995 			rack->r_ctl.rc_reorder_shift = optval;
19996 		else
19997 			error = EINVAL;
19998 		break;
19999 	case TCP_RACK_REORD_FADE:
20000 		/* Does reordering fade after ms time */
20001 		RACK_OPTS_INC(tcp_rack_reord_fade);
20002 		rack->r_ctl.rc_reorder_fade = optval;
20003 		break;
20004 	case TCP_RACK_TLP_THRESH:
20005 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
20006 		RACK_OPTS_INC(tcp_rack_tlp_thresh);
20007 		if (optval)
20008 			rack->r_ctl.rc_tlp_threshold = optval;
20009 		else
20010 			error = EINVAL;
20011 		break;
20012 	case TCP_BBR_USE_RACK_RR:
20013 		RACK_OPTS_INC(tcp_rack_rr);
20014 		if (optval)
20015 			rack->use_rack_rr = 1;
20016 		else
20017 			rack->use_rack_rr = 0;
20018 		break;
20019 	case TCP_FAST_RSM_HACK:
20020 		RACK_OPTS_INC(tcp_rack_fastrsm_hack);
20021 		if (optval)
20022 			rack->fast_rsm_hack = 1;
20023 		else
20024 			rack->fast_rsm_hack = 0;
20025 		break;
20026 	case TCP_RACK_PKT_DELAY:
20027 		/* RACK added ms i.e. rack-rtt + reord + N */
20028 		RACK_OPTS_INC(tcp_rack_pkt_delay);
20029 		rack->r_ctl.rc_pkt_delay = optval;
20030 		break;
20031 	case TCP_DELACK:
20032 		RACK_OPTS_INC(tcp_rack_delayed_ack);
20033 		if (optval == 0)
20034 			tp->t_delayed_ack = 0;
20035 		else
20036 			tp->t_delayed_ack = 1;
20037 		if (tp->t_flags & TF_DELACK) {
20038 			tp->t_flags &= ~TF_DELACK;
20039 			tp->t_flags |= TF_ACKNOW;
20040 			NET_EPOCH_ENTER(et);
20041 			rack_output(tp);
20042 			NET_EPOCH_EXIT(et);
20043 		}
20044 		break;
20045 
20046 	case TCP_BBR_RACK_RTT_USE:
20047 		RACK_OPTS_INC(tcp_rack_rtt_use);
20048 		if ((optval != USE_RTT_HIGH) &&
20049 		    (optval != USE_RTT_LOW) &&
20050 		    (optval != USE_RTT_AVG))
20051 			error = EINVAL;
20052 		else
20053 			rack->r_ctl.rc_rate_sample_method = optval;
20054 		break;
20055 	case TCP_DATA_AFTER_CLOSE:
20056 		RACK_OPTS_INC(tcp_data_after_close);
20057 		if (optval)
20058 			rack->rc_allow_data_af_clo = 1;
20059 		else
20060 			rack->rc_allow_data_af_clo = 0;
20061 		break;
20062 	default:
20063 		break;
20064 	}
20065 #ifdef NETFLIX_STATS
20066 	tcp_log_socket_option(tp, sopt_name, optval, error);
20067 #endif
20068 	return (error);
20069 }
20070 
20071 
20072 static void
20073 rack_apply_deferred_options(struct tcp_rack *rack)
20074 {
20075 	struct deferred_opt_list *dol, *sdol;
20076 	uint32_t s_optval;
20077 
20078 	TAILQ_FOREACH_SAFE(dol, &rack->r_ctl.opt_list, next, sdol) {
20079 		TAILQ_REMOVE(&rack->r_ctl.opt_list, dol, next);
20080 		/* Disadvantage of deferal is you loose the error return */
20081 		s_optval = (uint32_t)dol->optval;
20082 		(void)rack_process_option(rack->rc_tp, rack, dol->optname, s_optval, dol->optval);
20083 		free(dol, M_TCPDO);
20084 	}
20085 }
20086 
20087 static void
20088 rack_hw_tls_change(struct tcpcb *tp, int chg)
20089 {
20090 	/*
20091 	 * HW tls state has changed.. fix all
20092 	 * rsm's in flight.
20093 	 */
20094 	struct tcp_rack *rack;
20095 	struct rack_sendmap *rsm;
20096 
20097 	rack = (struct tcp_rack *)tp->t_fb_ptr;
20098 	RB_FOREACH(rsm, rack_rb_tree_head, &rack->r_ctl.rc_mtree) {
20099 		if (chg)
20100 			rsm->r_hw_tls = 1;
20101 		else
20102 			rsm->r_hw_tls = 0;
20103 	}
20104 	if (chg)
20105 		rack->r_ctl.fsb.hw_tls = 1;
20106 	else
20107 		rack->r_ctl.fsb.hw_tls = 0;
20108 }
20109 
20110 static int
20111 rack_pru_options(struct tcpcb *tp, int flags)
20112 {
20113 	if (flags & PRUS_OOB)
20114 		return (EOPNOTSUPP);
20115 	return (0);
20116 }
20117 
20118 static struct tcp_function_block __tcp_rack = {
20119 	.tfb_tcp_block_name = __XSTRING(STACKNAME),
20120 	.tfb_tcp_output = rack_output,
20121 	.tfb_do_queued_segments = ctf_do_queued_segments,
20122 	.tfb_do_segment_nounlock = rack_do_segment_nounlock,
20123 	.tfb_tcp_do_segment = rack_do_segment,
20124 	.tfb_tcp_ctloutput = rack_ctloutput,
20125 	.tfb_tcp_fb_init = rack_init,
20126 	.tfb_tcp_fb_fini = rack_fini,
20127 	.tfb_tcp_timer_stop_all = rack_stopall,
20128 	.tfb_tcp_timer_activate = rack_timer_activate,
20129 	.tfb_tcp_timer_active = rack_timer_active,
20130 	.tfb_tcp_timer_stop = rack_timer_stop,
20131 	.tfb_tcp_rexmit_tmr = rack_remxt_tmr,
20132 	.tfb_tcp_handoff_ok = rack_handoff_ok,
20133 	.tfb_tcp_mtu_chg = rack_mtu_change,
20134 	.tfb_pru_options = rack_pru_options,
20135 	.tfb_hwtls_change = rack_hw_tls_change,
20136 	.tfb_flags = TCP_FUNC_OUTPUT_CANDROP,
20137 };
20138 
20139 /*
20140  * rack_ctloutput() must drop the inpcb lock before performing copyin on
20141  * socket option arguments.  When it re-acquires the lock after the copy, it
20142  * has to revalidate that the connection is still valid for the socket
20143  * option.
20144  */
20145 static int
20146 rack_set_sockopt(struct inpcb *inp, struct sockopt *sopt)
20147 {
20148 #ifdef INET6
20149 	struct ip6_hdr *ip6;
20150 #endif
20151 #ifdef INET
20152 	struct ip *ip;
20153 #endif
20154 	struct tcpcb *tp;
20155 	struct tcp_rack *rack;
20156 	uint64_t loptval;
20157 	int32_t error = 0, optval;
20158 
20159 	tp = intotcpcb(inp);
20160 	rack = (struct tcp_rack *)tp->t_fb_ptr;
20161 	if (rack == NULL) {
20162 		INP_WUNLOCK(inp);
20163 		return (EINVAL);
20164 	}
20165 #ifdef INET6
20166 	ip6 = (struct ip6_hdr *)rack->r_ctl.fsb.tcp_ip_hdr;
20167 #endif
20168 #ifdef INET
20169 	ip = (struct ip *)rack->r_ctl.fsb.tcp_ip_hdr;
20170 #endif
20171 
20172 	switch (sopt->sopt_level) {
20173 #ifdef INET6
20174 	case IPPROTO_IPV6:
20175 		MPASS(inp->inp_vflag & INP_IPV6PROTO);
20176 		switch (sopt->sopt_name) {
20177 		case IPV6_USE_MIN_MTU:
20178 			tcp6_use_min_mtu(tp);
20179 			break;
20180 		case IPV6_TCLASS:
20181 			/*
20182 			 * The DSCP codepoint has changed, update the fsb.
20183 			 */
20184 			ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
20185 			    (rack->rc_inp->inp_flow & IPV6_FLOWINFO_MASK);
20186 			break;
20187 		}
20188 		INP_WUNLOCK(inp);
20189 		return (0);
20190 #endif
20191 #ifdef INET
20192 	case IPPROTO_IP:
20193 		switch (sopt->sopt_name) {
20194 		case IP_TOS:
20195 			/*
20196 			 * The DSCP codepoint has changed, update the fsb.
20197 			 */
20198 			ip->ip_tos = rack->rc_inp->inp_ip_tos;
20199 			break;
20200 		case IP_TTL:
20201 			/*
20202 			 * The TTL has changed, update the fsb.
20203 			 */
20204 			ip->ip_ttl = rack->rc_inp->inp_ip_ttl;
20205 			break;
20206 		}
20207 		INP_WUNLOCK(inp);
20208 		return (0);
20209 #endif
20210 	}
20211 
20212 	switch (sopt->sopt_name) {
20213 	case TCP_RACK_TLP_REDUCE:		/*  URL:tlp_reduce */
20214 	/*  Pacing related ones */
20215 	case TCP_RACK_PACE_ALWAYS:		/*  URL:pace_always */
20216 	case TCP_BBR_RACK_INIT_RATE:		/*  URL:irate */
20217 	case TCP_BBR_IWINTSO:			/*  URL:tso_iwin */
20218 	case TCP_RACK_PACE_MAX_SEG:		/*  URL:pace_max_seg */
20219 	case TCP_RACK_FORCE_MSEG:		/*  URL:force_max_seg */
20220 	case TCP_RACK_PACE_RATE_CA:		/*  URL:pr_ca */
20221 	case TCP_RACK_PACE_RATE_SS:		/*  URL:pr_ss*/
20222 	case TCP_RACK_PACE_RATE_REC:		/*  URL:pr_rec */
20223 	case TCP_RACK_GP_INCREASE_CA:		/*  URL:gp_inc_ca */
20224 	case TCP_RACK_GP_INCREASE_SS:		/*  URL:gp_inc_ss */
20225 	case TCP_RACK_GP_INCREASE_REC:		/*  URL:gp_inc_rec */
20226 	case TCP_RACK_RR_CONF:			/*  URL:rrr_conf */
20227 	case TCP_BBR_HDWR_PACE:			/*  URL:hdwrpace */
20228 	case TCP_HDWR_RATE_CAP:			/*  URL:hdwrcap boolean */
20229 	case TCP_PACING_RATE_CAP:		/*  URL:cap  -- used by side-channel */
20230 	case TCP_HDWR_UP_ONLY:			/*  URL:uponly -- hardware pacing  boolean */
20231        /* End pacing related */
20232 	case TCP_FAST_RSM_HACK:			/*  URL:frsm_hack */
20233 	case TCP_DELACK:			/*  URL:delack (in base TCP i.e. tcp_hints along with cc etc ) */
20234 	case TCP_RACK_PRR_SENDALOT:		/*  URL:prr_sendalot */
20235 	case TCP_RACK_MIN_TO:			/*  URL:min_to */
20236 	case TCP_RACK_EARLY_SEG:		/*  URL:early_seg */
20237 	case TCP_RACK_REORD_THRESH:		/*  URL:reord_thresh */
20238 	case TCP_RACK_REORD_FADE:		/*  URL:reord_fade */
20239 	case TCP_RACK_TLP_THRESH:		/*  URL:tlp_thresh */
20240 	case TCP_RACK_PKT_DELAY:		/*  URL:pkt_delay */
20241 	case TCP_RACK_TLP_USE:			/*  URL:tlp_use */
20242 	case TCP_BBR_RACK_RTT_USE:		/*  URL:rttuse */
20243 	case TCP_BBR_USE_RACK_RR:		/*  URL:rackrr */
20244 	case TCP_RACK_DO_DETECTION:		/*  URL:detect */
20245 	case TCP_NO_PRR:			/*  URL:noprr */
20246 	case TCP_TIMELY_DYN_ADJ:      		/*  URL:dynamic */
20247 	case TCP_DATA_AFTER_CLOSE:		/*  no URL */
20248 	case TCP_RACK_NONRXT_CFG_RATE:		/*  URL:nonrxtcr */
20249 	case TCP_SHARED_CWND_ENABLE:		/*  URL:scwnd */
20250 	case TCP_RACK_MBUF_QUEUE:		/*  URL:mqueue */
20251 	case TCP_RACK_NO_PUSH_AT_MAX:		/*  URL:npush */
20252 	case TCP_RACK_PACE_TO_FILL:		/*  URL:fillcw */
20253 	case TCP_SHARED_CWND_TIME_LIMIT:	/*  URL:lscwnd */
20254 	case TCP_RACK_PROFILE:			/*  URL:profile */
20255 	case TCP_USE_CMP_ACKS:			/*  URL:cmpack */
20256 	case TCP_RACK_ABC_VAL:			/*  URL:labc */
20257 	case TCP_REC_ABC_VAL:			/*  URL:reclabc */
20258 	case TCP_RACK_MEASURE_CNT:		/*  URL:measurecnt */
20259 	case TCP_DEFER_OPTIONS:			/*  URL:defer */
20260 	case TCP_RACK_DSACK_OPT:		/*  URL:dsack */
20261 	case TCP_RACK_PACING_BETA:		/*  URL:pacing_beta */
20262 	case TCP_RACK_PACING_BETA_ECN:		/*  URL:pacing_beta_ecn */
20263 	case TCP_RACK_TIMER_SLOP:		/*  URL:timer_slop */
20264 	case TCP_RACK_ENABLE_HYSTART:		/*  URL:hystart */
20265 		break;
20266 	default:
20267 		/* Filter off all unknown options to the base stack */
20268 		return (tcp_default_ctloutput(inp, sopt));
20269 		break;
20270 	}
20271 	INP_WUNLOCK(inp);
20272 	if (sopt->sopt_name == TCP_PACING_RATE_CAP) {
20273 		error = sooptcopyin(sopt, &loptval, sizeof(loptval), sizeof(loptval));
20274 		/*
20275 		 * We truncate it down to 32 bits for the socket-option trace this
20276 		 * means rates > 34Gbps won't show right, but thats probably ok.
20277 		 */
20278 		optval = (uint32_t)loptval;
20279 	} else {
20280 		error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval));
20281 		/* Save it in 64 bit form too */
20282 		loptval = optval;
20283 	}
20284 	if (error)
20285 		return (error);
20286 	INP_WLOCK(inp);
20287 	if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
20288 		INP_WUNLOCK(inp);
20289 		return (ECONNRESET);
20290 	}
20291 	if (tp->t_fb != &__tcp_rack) {
20292 		INP_WUNLOCK(inp);
20293 		return (ENOPROTOOPT);
20294 	}
20295 	if (rack->defer_options && (rack->gp_ready == 0) &&
20296 	    (sopt->sopt_name != TCP_DEFER_OPTIONS) &&
20297 	    (sopt->sopt_name != TCP_RACK_PACING_BETA) &&
20298 	    (sopt->sopt_name != TCP_RACK_PACING_BETA_ECN) &&
20299 	    (sopt->sopt_name != TCP_RACK_MEASURE_CNT)) {
20300 		/* Options are beind deferred */
20301 		if (rack_add_deferred_option(rack, sopt->sopt_name, loptval)) {
20302 			INP_WUNLOCK(inp);
20303 			return (0);
20304 		} else {
20305 			/* No memory to defer, fail */
20306 			INP_WUNLOCK(inp);
20307 			return (ENOMEM);
20308 		}
20309 	}
20310 	error = rack_process_option(tp, rack, sopt->sopt_name, optval, loptval);
20311 	INP_WUNLOCK(inp);
20312 	return (error);
20313 }
20314 
20315 static void
20316 rack_fill_info(struct tcpcb *tp, struct tcp_info *ti)
20317 {
20318 
20319 	INP_WLOCK_ASSERT(tp->t_inpcb);
20320 	bzero(ti, sizeof(*ti));
20321 
20322 	ti->tcpi_state = tp->t_state;
20323 	if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
20324 		ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
20325 	if (tp->t_flags & TF_SACK_PERMIT)
20326 		ti->tcpi_options |= TCPI_OPT_SACK;
20327 	if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
20328 		ti->tcpi_options |= TCPI_OPT_WSCALE;
20329 		ti->tcpi_snd_wscale = tp->snd_scale;
20330 		ti->tcpi_rcv_wscale = tp->rcv_scale;
20331 	}
20332 	if (tp->t_flags2 & TF2_ECN_PERMIT)
20333 		ti->tcpi_options |= TCPI_OPT_ECN;
20334 	if (tp->t_flags & TF_FASTOPEN)
20335 		ti->tcpi_options |= TCPI_OPT_TFO;
20336 	/* still kept in ticks is t_rcvtime */
20337 	ti->tcpi_last_data_recv = ((uint32_t)ticks - tp->t_rcvtime) * tick;
20338 	/* Since we hold everything in precise useconds this is easy */
20339 	ti->tcpi_rtt = tp->t_srtt;
20340 	ti->tcpi_rttvar = tp->t_rttvar;
20341 	ti->tcpi_rto = tp->t_rxtcur;
20342 	ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
20343 	ti->tcpi_snd_cwnd = tp->snd_cwnd;
20344 	/*
20345 	 * FreeBSD-specific extension fields for tcp_info.
20346 	 */
20347 	ti->tcpi_rcv_space = tp->rcv_wnd;
20348 	ti->tcpi_rcv_nxt = tp->rcv_nxt;
20349 	ti->tcpi_snd_wnd = tp->snd_wnd;
20350 	ti->tcpi_snd_bwnd = 0;		/* Unused, kept for compat. */
20351 	ti->tcpi_snd_nxt = tp->snd_nxt;
20352 	ti->tcpi_snd_mss = tp->t_maxseg;
20353 	ti->tcpi_rcv_mss = tp->t_maxseg;
20354 	ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;
20355 	ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
20356 	ti->tcpi_snd_zerowin = tp->t_sndzerowin;
20357 #ifdef NETFLIX_STATS
20358 	ti->tcpi_total_tlp = tp->t_sndtlppack;
20359 	ti->tcpi_total_tlp_bytes = tp->t_sndtlpbyte;
20360 	memcpy(&ti->tcpi_rxsyninfo, &tp->t_rxsyninfo, sizeof(struct tcpsyninfo));
20361 #endif
20362 #ifdef TCP_OFFLOAD
20363 	if (tp->t_flags & TF_TOE) {
20364 		ti->tcpi_options |= TCPI_OPT_TOE;
20365 		tcp_offload_tcp_info(tp, ti);
20366 	}
20367 #endif
20368 }
20369 
20370 static int
20371 rack_get_sockopt(struct inpcb *inp, struct sockopt *sopt)
20372 {
20373 	struct tcpcb *tp;
20374 	struct tcp_rack *rack;
20375 	int32_t error, optval;
20376 	uint64_t val, loptval;
20377 	struct	tcp_info ti;
20378 	/*
20379 	 * Because all our options are either boolean or an int, we can just
20380 	 * pull everything into optval and then unlock and copy. If we ever
20381 	 * add a option that is not a int, then this will have quite an
20382 	 * impact to this routine.
20383 	 */
20384 	error = 0;
20385 	tp = intotcpcb(inp);
20386 	rack = (struct tcp_rack *)tp->t_fb_ptr;
20387 	if (rack == NULL) {
20388 		INP_WUNLOCK(inp);
20389 		return (EINVAL);
20390 	}
20391 	switch (sopt->sopt_name) {
20392 	case TCP_INFO:
20393 		/* First get the info filled */
20394 		rack_fill_info(tp, &ti);
20395 		/* Fix up the rtt related fields if needed */
20396 		INP_WUNLOCK(inp);
20397 		error = sooptcopyout(sopt, &ti, sizeof ti);
20398 		return (error);
20399 	/*
20400 	 * Beta is the congestion control value for NewReno that influences how
20401 	 * much of a backoff happens when loss is detected. It is normally set
20402 	 * to 50 for 50% i.e. the cwnd is reduced to 50% of its previous value
20403 	 * when you exit recovery.
20404 	 */
20405 	case TCP_RACK_PACING_BETA:
20406 		if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0)
20407 			error = EINVAL;
20408 		else if (rack->rc_pacing_cc_set == 0)
20409 			optval = rack->r_ctl.rc_saved_beta.beta;
20410 		else {
20411 			/*
20412 			 * Reach out into the CC data and report back what
20413 			 * I have previously set. Yeah it looks hackish but
20414 			 * we don't want to report the saved values.
20415 			 */
20416 			if (tp->ccv->cc_data)
20417 				optval = ((struct newreno *)tp->ccv->cc_data)->beta;
20418 			else
20419 				error = EINVAL;
20420 		}
20421 		break;
20422 		/*
20423 		 * Beta_ecn is the congestion control value for NewReno that influences how
20424 		 * much of a backoff happens when a ECN mark is detected. It is normally set
20425 		 * to 80 for 80% i.e. the cwnd is reduced by 20% of its previous value when
20426 		 * you exit recovery. Note that classic ECN has a beta of 50, it is only
20427 		 * ABE Ecn that uses this "less" value, but we do too with pacing :)
20428 		 */
20429 
20430 	case TCP_RACK_PACING_BETA_ECN:
20431 		if (strcmp(tp->cc_algo->name, CCALGONAME_NEWRENO) != 0)
20432 			error = EINVAL;
20433 		else if (rack->rc_pacing_cc_set == 0)
20434 			optval = rack->r_ctl.rc_saved_beta.beta_ecn;
20435 		else {
20436 			/*
20437 			 * Reach out into the CC data and report back what
20438 			 * I have previously set. Yeah it looks hackish but
20439 			 * we don't want to report the saved values.
20440 			 */
20441 			if (tp->ccv->cc_data)
20442 				optval = ((struct newreno *)tp->ccv->cc_data)->beta_ecn;
20443 			else
20444 				error = EINVAL;
20445 		}
20446 		break;
20447 	case TCP_RACK_DSACK_OPT:
20448 		optval = 0;
20449 		if (rack->rc_rack_tmr_std_based) {
20450 			optval |= 1;
20451 		}
20452 		if (rack->rc_rack_use_dsack) {
20453 			optval |= 2;
20454 		}
20455 		break;
20456  	case TCP_RACK_ENABLE_HYSTART:
20457 	{
20458 		if (tp->ccv->flags & CCF_HYSTART_ALLOWED) {
20459 			optval = RACK_HYSTART_ON;
20460 			if (tp->ccv->flags & CCF_HYSTART_CAN_SH_CWND)
20461 				optval = RACK_HYSTART_ON_W_SC;
20462 			if (tp->ccv->flags & CCF_HYSTART_CONS_SSTH)
20463 				optval = RACK_HYSTART_ON_W_SC_C;
20464 		} else {
20465 			optval = RACK_HYSTART_OFF;
20466 		}
20467 	}
20468 	break;
20469 	case TCP_FAST_RSM_HACK:
20470 		optval = rack->fast_rsm_hack;
20471 		break;
20472 	case TCP_DEFER_OPTIONS:
20473 		optval = rack->defer_options;
20474 		break;
20475 	case TCP_RACK_MEASURE_CNT:
20476 		optval = rack->r_ctl.req_measurements;
20477 		break;
20478 	case TCP_REC_ABC_VAL:
20479 		optval = rack->r_use_labc_for_rec;
20480 		break;
20481 	case TCP_RACK_ABC_VAL:
20482 		optval = rack->rc_labc;
20483 		break;
20484 	case TCP_HDWR_UP_ONLY:
20485 		optval= rack->r_up_only;
20486 		break;
20487 	case TCP_PACING_RATE_CAP:
20488 		loptval = rack->r_ctl.bw_rate_cap;
20489 		break;
20490 	case TCP_RACK_PROFILE:
20491 		/* You cannot retrieve a profile, its write only */
20492 		error = EINVAL;
20493 		break;
20494 	case TCP_USE_CMP_ACKS:
20495 		optval = rack->r_use_cmp_ack;
20496 		break;
20497 	case TCP_RACK_PACE_TO_FILL:
20498 		optval = rack->rc_pace_to_cwnd;
20499 		if (optval && rack->r_fill_less_agg)
20500 			optval++;
20501 		break;
20502 	case TCP_RACK_NO_PUSH_AT_MAX:
20503 		optval = rack->r_ctl.rc_no_push_at_mrtt;
20504 		break;
20505 	case TCP_SHARED_CWND_ENABLE:
20506 		optval = rack->rack_enable_scwnd;
20507 		break;
20508 	case TCP_RACK_NONRXT_CFG_RATE:
20509 		optval = rack->rack_rec_nonrxt_use_cr;
20510 		break;
20511 	case TCP_NO_PRR:
20512 		if (rack->rack_no_prr  == 1)
20513 			optval = 1;
20514 		else if (rack->no_prr_addback == 1)
20515 			optval = 2;
20516 		else
20517 			optval = 0;
20518 		break;
20519 	case TCP_RACK_DO_DETECTION:
20520 		optval = rack->do_detection;
20521 		break;
20522 	case TCP_RACK_MBUF_QUEUE:
20523 		/* Now do we use the LRO mbuf-queue feature */
20524 		optval = rack->r_mbuf_queue;
20525 		break;
20526 	case TCP_TIMELY_DYN_ADJ:
20527 		optval = rack->rc_gp_dyn_mul;
20528 		break;
20529 	case TCP_BBR_IWINTSO:
20530 		optval = rack->rc_init_win;
20531 		break;
20532 	case TCP_RACK_TLP_REDUCE:
20533 		/* RACK TLP cwnd reduction (bool) */
20534 		optval = rack->r_ctl.rc_tlp_cwnd_reduce;
20535 		break;
20536 	case TCP_BBR_RACK_INIT_RATE:
20537 		val = rack->r_ctl.init_rate;
20538 		/* convert to kbits per sec */
20539 		val *= 8;
20540 		val /= 1000;
20541 		optval = (uint32_t)val;
20542 		break;
20543 	case TCP_RACK_FORCE_MSEG:
20544 		optval = rack->rc_force_max_seg;
20545 		break;
20546 	case TCP_RACK_PACE_MAX_SEG:
20547 		/* Max segments in a pace */
20548 		optval = rack->rc_user_set_max_segs;
20549 		break;
20550 	case TCP_RACK_PACE_ALWAYS:
20551 		/* Use the always pace method */
20552 		optval = rack->rc_always_pace;
20553 		break;
20554 	case TCP_RACK_PRR_SENDALOT:
20555 		/* Allow PRR to send more than one seg */
20556 		optval = rack->r_ctl.rc_prr_sendalot;
20557 		break;
20558 	case TCP_RACK_MIN_TO:
20559 		/* Minimum time between rack t-o's in ms */
20560 		optval = rack->r_ctl.rc_min_to;
20561 		break;
20562 	case TCP_RACK_EARLY_SEG:
20563 		/* If early recovery max segments */
20564 		optval = rack->r_ctl.rc_early_recovery_segs;
20565 		break;
20566 	case TCP_RACK_REORD_THRESH:
20567 		/* RACK reorder threshold (shift amount) */
20568 		optval = rack->r_ctl.rc_reorder_shift;
20569 		break;
20570 	case TCP_RACK_REORD_FADE:
20571 		/* Does reordering fade after ms time */
20572 		optval = rack->r_ctl.rc_reorder_fade;
20573 		break;
20574 	case TCP_BBR_USE_RACK_RR:
20575 		/* Do we use the rack cheat for rxt */
20576 		optval = rack->use_rack_rr;
20577 		break;
20578 	case TCP_RACK_RR_CONF:
20579 		optval = rack->r_rr_config;
20580 		break;
20581 	case TCP_HDWR_RATE_CAP:
20582 		optval = rack->r_rack_hw_rate_caps;
20583 		break;
20584 	case TCP_BBR_HDWR_PACE:
20585 		optval = rack->rack_hdw_pace_ena;
20586 		break;
20587 	case TCP_RACK_TLP_THRESH:
20588 		/* RACK TLP theshold i.e. srtt+(srtt/N) */
20589 		optval = rack->r_ctl.rc_tlp_threshold;
20590 		break;
20591 	case TCP_RACK_PKT_DELAY:
20592 		/* RACK added ms i.e. rack-rtt + reord + N */
20593 		optval = rack->r_ctl.rc_pkt_delay;
20594 		break;
20595 	case TCP_RACK_TLP_USE:
20596 		optval = rack->rack_tlp_threshold_use;
20597 		break;
20598 	case TCP_RACK_PACE_RATE_CA:
20599 		optval = rack->r_ctl.rc_fixed_pacing_rate_ca;
20600 		break;
20601 	case TCP_RACK_PACE_RATE_SS:
20602 		optval = rack->r_ctl.rc_fixed_pacing_rate_ss;
20603 		break;
20604 	case TCP_RACK_PACE_RATE_REC:
20605 		optval = rack->r_ctl.rc_fixed_pacing_rate_rec;
20606 		break;
20607 	case TCP_RACK_GP_INCREASE_SS:
20608 		optval = rack->r_ctl.rack_per_of_gp_ca;
20609 		break;
20610 	case TCP_RACK_GP_INCREASE_CA:
20611 		optval = rack->r_ctl.rack_per_of_gp_ss;
20612 		break;
20613 	case TCP_BBR_RACK_RTT_USE:
20614 		optval = rack->r_ctl.rc_rate_sample_method;
20615 		break;
20616 	case TCP_DELACK:
20617 		optval = tp->t_delayed_ack;
20618 		break;
20619 	case TCP_DATA_AFTER_CLOSE:
20620 		optval = rack->rc_allow_data_af_clo;
20621 		break;
20622 	case TCP_SHARED_CWND_TIME_LIMIT:
20623 		optval = rack->r_limit_scw;
20624 		break;
20625 	case TCP_RACK_TIMER_SLOP:
20626 		optval = rack->r_ctl.timer_slop;
20627 		break;
20628 	default:
20629 		return (tcp_default_ctloutput(inp, sopt));
20630 		break;
20631 	}
20632 	INP_WUNLOCK(inp);
20633 	if (error == 0) {
20634 		if (TCP_PACING_RATE_CAP)
20635 			error = sooptcopyout(sopt, &loptval, sizeof loptval);
20636 		else
20637 			error = sooptcopyout(sopt, &optval, sizeof optval);
20638 	}
20639 	return (error);
20640 }
20641 
20642 static int
20643 rack_ctloutput(struct inpcb *inp, struct sockopt *sopt)
20644 {
20645 	if (sopt->sopt_dir == SOPT_SET) {
20646 		return (rack_set_sockopt(inp, sopt));
20647 	} else if (sopt->sopt_dir == SOPT_GET) {
20648 		return (rack_get_sockopt(inp, sopt));
20649 	} else {
20650 		panic("%s: sopt_dir $%d", __func__, sopt->sopt_dir);
20651 	}
20652 }
20653 
20654 static const char *rack_stack_names[] = {
20655 	__XSTRING(STACKNAME),
20656 #ifdef STACKALIAS
20657 	__XSTRING(STACKALIAS),
20658 #endif
20659 };
20660 
20661 static int
20662 rack_ctor(void *mem, int32_t size, void *arg, int32_t how)
20663 {
20664 	memset(mem, 0, size);
20665 	return (0);
20666 }
20667 
20668 static void
20669 rack_dtor(void *mem, int32_t size, void *arg)
20670 {
20671 
20672 }
20673 
20674 static bool rack_mod_inited = false;
20675 
20676 static int
20677 tcp_addrack(module_t mod, int32_t type, void *data)
20678 {
20679 	int32_t err = 0;
20680 	int num_stacks;
20681 
20682 	switch (type) {
20683 	case MOD_LOAD:
20684 		rack_zone = uma_zcreate(__XSTRING(MODNAME) "_map",
20685 		    sizeof(struct rack_sendmap),
20686 		    rack_ctor, rack_dtor, NULL, NULL, UMA_ALIGN_PTR, 0);
20687 
20688 		rack_pcb_zone = uma_zcreate(__XSTRING(MODNAME) "_pcb",
20689 		    sizeof(struct tcp_rack),
20690 		    rack_ctor, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
20691 
20692 		sysctl_ctx_init(&rack_sysctl_ctx);
20693 		rack_sysctl_root = SYSCTL_ADD_NODE(&rack_sysctl_ctx,
20694 		    SYSCTL_STATIC_CHILDREN(_net_inet_tcp),
20695 		    OID_AUTO,
20696 #ifdef STACKALIAS
20697 		    __XSTRING(STACKALIAS),
20698 #else
20699 		    __XSTRING(STACKNAME),
20700 #endif
20701 		    CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
20702 		    "");
20703 		if (rack_sysctl_root == NULL) {
20704 			printf("Failed to add sysctl node\n");
20705 			err = EFAULT;
20706 			goto free_uma;
20707 		}
20708 		rack_init_sysctls();
20709 		num_stacks = nitems(rack_stack_names);
20710 		err = register_tcp_functions_as_names(&__tcp_rack, M_WAITOK,
20711 		    rack_stack_names, &num_stacks);
20712 		if (err) {
20713 			printf("Failed to register %s stack name for "
20714 			    "%s module\n", rack_stack_names[num_stacks],
20715 			    __XSTRING(MODNAME));
20716 			sysctl_ctx_free(&rack_sysctl_ctx);
20717 free_uma:
20718 			uma_zdestroy(rack_zone);
20719 			uma_zdestroy(rack_pcb_zone);
20720 			rack_counter_destroy();
20721 			printf("Failed to register rack module -- err:%d\n", err);
20722 			return (err);
20723 		}
20724 		tcp_lro_reg_mbufq();
20725 		rack_mod_inited = true;
20726 		break;
20727 	case MOD_QUIESCE:
20728 		err = deregister_tcp_functions(&__tcp_rack, true, false);
20729 		break;
20730 	case MOD_UNLOAD:
20731 		err = deregister_tcp_functions(&__tcp_rack, false, true);
20732 		if (err == EBUSY)
20733 			break;
20734 		if (rack_mod_inited) {
20735 			uma_zdestroy(rack_zone);
20736 			uma_zdestroy(rack_pcb_zone);
20737 			sysctl_ctx_free(&rack_sysctl_ctx);
20738 			rack_counter_destroy();
20739 			rack_mod_inited = false;
20740 		}
20741 		tcp_lro_dereg_mbufq();
20742 		err = 0;
20743 		break;
20744 	default:
20745 		return (EOPNOTSUPP);
20746 	}
20747 	return (err);
20748 }
20749 
20750 static moduledata_t tcp_rack = {
20751 	.name = __XSTRING(MODNAME),
20752 	.evhand = tcp_addrack,
20753 	.priv = 0
20754 };
20755 
20756 MODULE_VERSION(MODNAME, 1);
20757 DECLARE_MODULE(MODNAME, tcp_rack, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
20758 MODULE_DEPEND(MODNAME, tcphpts, 1, 1, 1);
20759