1 /*-
2 * Copyright (c) 2016-2020 Netflix, Inc.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 *
25 */
26 /**
27 * Author: Randall Stewart <rrs@netflix.com>
28 * This work is based on the ACM Queue paper
29 * BBR - Congestion Based Congestion Control
30 * and also numerous discussions with Neal, Yuchung and Van.
31 */
32
33 #include <sys/cdefs.h>
34 #include "opt_inet.h"
35 #include "opt_inet6.h"
36 #include "opt_ipsec.h"
37 #include "opt_ratelimit.h"
38 #include <sys/param.h>
39 #include <sys/arb.h>
40 #include <sys/module.h>
41 #include <sys/kernel.h>
42 #include <sys/libkern.h>
43 #ifdef TCP_HHOOK
44 #include <sys/hhook.h>
45 #endif
46 #include <sys/malloc.h>
47 #include <sys/mbuf.h>
48 #include <sys/proc.h>
49 #include <sys/socket.h>
50 #include <sys/socketvar.h>
51 #include <sys/sysctl.h>
52 #include <sys/systm.h>
53 #ifdef STATS
54 #include <sys/qmath.h>
55 #include <sys/tree.h>
56 #include <sys/stats.h> /* Must come after qmath.h and tree.h */
57 #endif
58 #include <sys/refcount.h>
59 #include <sys/queue.h>
60 #include <sys/eventhandler.h>
61 #include <sys/smp.h>
62 #include <sys/kthread.h>
63 #include <sys/lock.h>
64 #include <sys/mutex.h>
65 #include <sys/tim_filter.h>
66 #include <sys/time.h>
67 #include <sys/protosw.h>
68 #include <vm/uma.h>
69 #include <sys/kern_prefetch.h>
70
71 #include <net/route.h>
72 #include <net/route/nhop.h>
73 #include <net/vnet.h>
74
75 #define TCPSTATES /* for logging */
76
77 #include <netinet/in.h>
78 #include <netinet/in_kdtrace.h>
79 #include <netinet/in_pcb.h>
80 #include <netinet/ip.h>
81 #include <netinet/ip_icmp.h> /* required for icmp_var.h */
82 #include <netinet/icmp_var.h> /* for ICMP_BANDLIM */
83 #include <netinet/ip_var.h>
84 #include <netinet/ip6.h>
85 #include <netinet6/in6_pcb.h>
86 #include <netinet6/ip6_var.h>
87 #define TCPOUTFLAGS
88 #include <netinet/tcp.h>
89 #include <netinet/tcp_fsm.h>
90 #include <netinet/tcp_seq.h>
91 #include <netinet/tcp_timer.h>
92 #include <netinet/tcp_var.h>
93 #include <netinet/tcpip.h>
94 #include <netinet/tcp_hpts.h>
95 #include <netinet/cc/cc.h>
96 #include <netinet/tcp_log_buf.h>
97 #include <netinet/tcp_ratelimit.h>
98 #include <netinet/tcp_lro.h>
99 #ifdef TCP_OFFLOAD
100 #include <netinet/tcp_offload.h>
101 #endif
102 #ifdef INET6
103 #include <netinet6/tcp6_var.h>
104 #endif
105 #include <netinet/tcp_fastopen.h>
106
107 #include <netipsec/ipsec_support.h>
108 #include <net/if.h>
109 #include <net/if_var.h>
110 #include <net/ethernet.h>
111
112 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
113 #include <netipsec/ipsec.h>
114 #include <netipsec/ipsec6.h>
115 #endif /* IPSEC */
116
117 #include <netinet/udp.h>
118 #include <netinet/udp_var.h>
119 #include <machine/in_cksum.h>
120
121 #ifdef MAC
122 #include <security/mac/mac_framework.h>
123 #endif
124
125 #include "sack_filter.h"
126 #include "tcp_bbr.h"
127 #include "rack_bbr_common.h"
128 uma_zone_t bbr_zone;
129 uma_zone_t bbr_pcb_zone;
130
131 struct sysctl_ctx_list bbr_sysctl_ctx;
132 struct sysctl_oid *bbr_sysctl_root;
133
134 #define TCPT_RANGESET_NOSLOP(tv, value, tvmin, tvmax) do { \
135 (tv) = (value); \
136 if ((u_long)(tv) < (u_long)(tvmin)) \
137 (tv) = (tvmin); \
138 if ((u_long)(tv) > (u_long)(tvmax)) \
139 (tv) = (tvmax); \
140 } while(0)
141
142 /*#define BBR_INVARIANT 1*/
143
144 /*
145 * initial window
146 */
147 static uint32_t bbr_def_init_win = 10;
148 static int32_t bbr_persist_min = 250000; /* 250ms */
149 static int32_t bbr_persist_max = 1000000; /* 1 Second */
150 static int32_t bbr_cwnd_may_shrink = 0;
151 static int32_t bbr_cwndtarget_rtt_touse = BBR_RTT_PROP;
152 static int32_t bbr_num_pktepo_for_del_limit = BBR_NUM_RTTS_FOR_DEL_LIMIT;
153 static int32_t bbr_hardware_pacing_limit = 8000;
154 static int32_t bbr_quanta = 3; /* How much extra quanta do we get? */
155 static int32_t bbr_no_retran = 0;
156
157 static int32_t bbr_error_base_paceout = 10000; /* usec to pace */
158 static int32_t bbr_max_net_error_cnt = 10;
159 /* Should the following be dynamic too -- loss wise */
160 static int32_t bbr_rtt_gain_thresh = 0;
161 /* Measurement controls */
162 static int32_t bbr_use_google_algo = 1;
163 static int32_t bbr_ts_limiting = 1;
164 static int32_t bbr_ts_can_raise = 0;
165 static int32_t bbr_do_red = 600;
166 static int32_t bbr_red_scale = 20000;
167 static int32_t bbr_red_mul = 1;
168 static int32_t bbr_red_div = 2;
169 static int32_t bbr_red_growth_restrict = 1;
170 static int32_t bbr_target_is_bbunit = 0;
171 static int32_t bbr_drop_limit = 0;
172 /*
173 * How much gain do we need to see to
174 * stay in startup?
175 */
176 static int32_t bbr_marks_rxt_sack_passed = 0;
177 static int32_t bbr_start_exit = 25;
178 static int32_t bbr_low_start_exit = 25; /* When we are in reduced gain */
179 static int32_t bbr_startup_loss_thresh = 2000; /* 20.00% loss */
180 static int32_t bbr_hptsi_max_mul = 1; /* These two mul/div assure a min pacing */
181 static int32_t bbr_hptsi_max_div = 2; /* time, 0 means turned off. We need this
182 * if we go back ever to where the pacer
183 * has priority over timers.
184 */
185 static int32_t bbr_policer_call_from_rack_to = 0;
186 static int32_t bbr_policer_detection_enabled = 1;
187 static int32_t bbr_min_measurements_req = 1; /* We need at least 2
188 * measurements before we are
189 * "good" note that 2 == 1.
190 * This is because we use a >
191 * comparison. This means if
192 * min_measure was 0, it takes
193 * num-measures > min(0) and
194 * you get 1 measurement and
195 * you are good. Set to 1, you
196 * have to have two
197 * measurements (this is done
198 * to prevent it from being ok
199 * to have no measurements). */
200 static int32_t bbr_no_pacing_until = 4;
201
202 static int32_t bbr_min_usec_delta = 20000; /* 20,000 usecs */
203 static int32_t bbr_min_peer_delta = 20; /* 20 units */
204 static int32_t bbr_delta_percent = 150; /* 15.0 % */
205
206 static int32_t bbr_target_cwnd_mult_limit = 8;
207 /*
208 * bbr_cwnd_min_val is the number of
209 * segments we hold to in the RTT probe
210 * state typically 4.
211 */
212 static int32_t bbr_cwnd_min_val = BBR_PROBERTT_NUM_MSS;
213
214 static int32_t bbr_cwnd_min_val_hs = BBR_HIGHSPEED_NUM_MSS;
215
216 static int32_t bbr_gain_to_target = 1;
217 static int32_t bbr_gain_gets_extra_too = 1;
218 /*
219 * bbr_high_gain is the 2/ln(2) value we need
220 * to double the sending rate in startup. This
221 * is used for both cwnd and hptsi gain's.
222 */
223 static int32_t bbr_high_gain = BBR_UNIT * 2885 / 1000 + 1;
224 static int32_t bbr_startup_lower = BBR_UNIT * 1500 / 1000 + 1;
225 static int32_t bbr_use_lower_gain_in_startup = 1;
226
227 /* thresholds for reduction on drain in sub-states/drain */
228 static int32_t bbr_drain_rtt = BBR_SRTT;
229 static int32_t bbr_drain_floor = 88;
230 static int32_t google_allow_early_out = 1;
231 static int32_t google_consider_lost = 1;
232 static int32_t bbr_drain_drop_mul = 4;
233 static int32_t bbr_drain_drop_div = 5;
234 static int32_t bbr_rand_ot = 50;
235 static int32_t bbr_can_force_probertt = 0;
236 static int32_t bbr_can_adjust_probertt = 1;
237 static int32_t bbr_probertt_sets_rtt = 0;
238 static int32_t bbr_can_use_ts_for_rtt = 1;
239 static int32_t bbr_is_ratio = 0;
240 static int32_t bbr_sub_drain_app_limit = 1;
241 static int32_t bbr_prtt_slam_cwnd = 1;
242 static int32_t bbr_sub_drain_slam_cwnd = 1;
243 static int32_t bbr_slam_cwnd_in_main_drain = 1;
244 static int32_t bbr_filter_len_sec = 6; /* How long does the rttProp filter
245 * hold */
246 static uint32_t bbr_rtt_probe_limit = (USECS_IN_SECOND * 4);
247 /*
248 * bbr_drain_gain is the reverse of the high_gain
249 * designed to drain back out the standing queue
250 * that is formed in startup by causing a larger
251 * hptsi gain and thus drainging the packets
252 * in flight.
253 */
254 static int32_t bbr_drain_gain = BBR_UNIT * 1000 / 2885;
255 static int32_t bbr_rttprobe_gain = 192;
256
257 /*
258 * The cwnd_gain is the default cwnd gain applied when
259 * calculating a target cwnd. Note that the cwnd is
260 * a secondary factor in the way BBR works (see the
261 * paper and think about it, it will take some time).
262 * Basically the hptsi_gain spreads the packets out
263 * so you never get more than BDP to the peer even
264 * if the cwnd is high. In our implemenation that
265 * means in non-recovery/retransmission scenarios
266 * cwnd will never be reached by the flight-size.
267 */
268 static int32_t bbr_cwnd_gain = BBR_UNIT * 2;
269 static int32_t bbr_tlp_type_to_use = BBR_SRTT;
270 static int32_t bbr_delack_time = 100000; /* 100ms in useconds */
271 static int32_t bbr_sack_not_required = 0; /* set to one to allow non-sack to use bbr */
272 static int32_t bbr_initial_bw_bps = 62500; /* 500kbps in bytes ps */
273 static int32_t bbr_ignore_data_after_close = 1;
274 static int16_t bbr_hptsi_gain[] = {
275 (BBR_UNIT *5 / 4),
276 (BBR_UNIT * 3 / 4),
277 BBR_UNIT,
278 BBR_UNIT,
279 BBR_UNIT,
280 BBR_UNIT,
281 BBR_UNIT,
282 BBR_UNIT
283 };
284 int32_t bbr_use_rack_resend_cheat = 1;
285 int32_t bbr_sends_full_iwnd = 1;
286
287 #define BBR_HPTSI_GAIN_MAX 8
288 /*
289 * The BBR module incorporates a number of
290 * TCP ideas that have been put out into the IETF
291 * over the last few years:
292 * - Yuchung Cheng's RACK TCP (for which its named) that
293 * will stop us using the number of dup acks and instead
294 * use time as the gage of when we retransmit.
295 * - Reorder Detection of RFC4737 and the Tail-Loss probe draft
296 * of Dukkipati et.al.
297 * - Van Jacobson's et.al BBR.
298 *
299 * RACK depends on SACK, so if an endpoint arrives that
300 * cannot do SACK the state machine below will shuttle the
301 * connection back to using the "default" TCP stack that is
302 * in FreeBSD.
303 *
304 * To implement BBR and RACK the original TCP stack was first decomposed
305 * into a functional state machine with individual states
306 * for each of the possible TCP connection states. The do_segment
307 * functions role in life is to mandate the connection supports SACK
308 * initially and then assure that the RACK state matches the conenction
309 * state before calling the states do_segment function. Data processing
310 * of inbound segments also now happens in the hpts_do_segment in general
311 * with only one exception. This is so we can keep the connection on
312 * a single CPU.
313 *
314 * Each state is simplified due to the fact that the original do_segment
315 * has been decomposed and we *know* what state we are in (no
316 * switches on the state) and all tests for SACK are gone. This
317 * greatly simplifies what each state does.
318 *
319 * TCP output is also over-written with a new version since it
320 * must maintain the new rack scoreboard and has had hptsi
321 * integrated as a requirment. Still todo is to eliminate the
322 * use of the callout_() system and use the hpts for all
323 * timers as well.
324 */
325 static uint32_t bbr_rtt_probe_time = 200000; /* 200ms in micro seconds */
326 static uint32_t bbr_rtt_probe_cwndtarg = 4; /* How many mss's outstanding */
327 static const int32_t bbr_min_req_free = 2; /* The min we must have on the
328 * free list */
329 static int32_t bbr_tlp_thresh = 1;
330 static int32_t bbr_reorder_thresh = 2;
331 static int32_t bbr_reorder_fade = 60000000; /* 0 - never fade, def
332 * 60,000,000 - 60 seconds */
333 static int32_t bbr_pkt_delay = 1000;
334 static int32_t bbr_min_to = 1000; /* Number of usec's minimum timeout */
335 static int32_t bbr_incr_timers = 1;
336
337 static int32_t bbr_tlp_min = 10000; /* 10ms in usecs */
338 static int32_t bbr_delayed_ack_time = 200000; /* 200ms in usecs */
339 static int32_t bbr_exit_startup_at_loss = 1;
340
341 /*
342 * bbr_lt_bw_ratio is 1/8th
343 * bbr_lt_bw_diff is < 4 Kbit/sec
344 */
345 static uint64_t bbr_lt_bw_diff = 4000 / 8; /* In bytes per second */
346 static uint64_t bbr_lt_bw_ratio = 8; /* For 1/8th */
347 static uint32_t bbr_lt_bw_max_rtts = 48; /* How many rtt's do we use
348 * the lt_bw for */
349 static uint32_t bbr_lt_intvl_min_rtts = 4; /* Min num of RTT's to measure
350 * lt_bw */
351 static int32_t bbr_lt_intvl_fp = 0; /* False positive epoch diff */
352 static int32_t bbr_lt_loss_thresh = 196; /* Lost vs delivered % */
353 static int32_t bbr_lt_fd_thresh = 100; /* false detection % */
354
355 static int32_t bbr_verbose_logging = 0;
356 /*
357 * Currently regular tcp has a rto_min of 30ms
358 * the backoff goes 12 times so that ends up
359 * being a total of 122.850 seconds before a
360 * connection is killed.
361 */
362 static int32_t bbr_rto_min_ms = 30; /* 30ms same as main freebsd */
363 static int32_t bbr_rto_max_sec = 4; /* 4 seconds */
364
365 /****************************************************/
366 /* DEFAULT TSO SIZING (cpu performance impacting) */
367 /****************************************************/
368 /* What amount is our formula using to get TSO size */
369 static int32_t bbr_hptsi_per_second = 1000;
370
371 /*
372 * For hptsi under bbr_cross_over connections what is delay
373 * target 7ms (in usec) combined with a seg_max of 2
374 * gets us close to identical google behavior in
375 * TSO size selection (possibly more 1MSS sends).
376 */
377 static int32_t bbr_hptsi_segments_delay_tar = 7000;
378
379 /* Does pacing delay include overhead's in its time calculations? */
380 static int32_t bbr_include_enet_oh = 0;
381 static int32_t bbr_include_ip_oh = 1;
382 static int32_t bbr_include_tcp_oh = 1;
383 static int32_t bbr_google_discount = 10;
384
385 /* Do we use (nf mode) pkt-epoch to drive us or rttProp? */
386 static int32_t bbr_state_is_pkt_epoch = 0;
387 static int32_t bbr_state_drain_2_tar = 1;
388 /* What is the max the 0 - bbr_cross_over MBPS TSO target
389 * can reach using our delay target. Note that this
390 * value becomes the floor for the cross over
391 * algorithm.
392 */
393 static int32_t bbr_hptsi_segments_max = 2;
394 static int32_t bbr_hptsi_segments_floor = 1;
395 static int32_t bbr_hptsi_utter_max = 0;
396
397 /* What is the min the 0 - bbr_cross-over MBPS TSO target can be */
398 static int32_t bbr_hptsi_bytes_min = 1460;
399 static int32_t bbr_all_get_min = 0;
400
401 /* Cross over point from algo-a to algo-b */
402 static uint32_t bbr_cross_over = TWENTY_THREE_MBPS;
403
404 /* Do we deal with our restart state? */
405 static int32_t bbr_uses_idle_restart = 0;
406 static int32_t bbr_idle_restart_threshold = 100000; /* 100ms in useconds */
407
408 /* Do we allow hardware pacing? */
409 static int32_t bbr_allow_hdwr_pacing = 0;
410 static int32_t bbr_hdwr_pace_adjust = 2; /* multipler when we calc the tso size */
411 static int32_t bbr_hdwr_pace_floor = 1;
412 static int32_t bbr_hdwr_pacing_delay_cnt = 10;
413
414 /****************************************************/
415 static int32_t bbr_resends_use_tso = 0;
416 static int32_t bbr_tlp_max_resend = 2;
417 static int32_t bbr_sack_block_limit = 128;
418
419 #define BBR_MAX_STAT 19
420 counter_u64_t bbr_state_time[BBR_MAX_STAT];
421 counter_u64_t bbr_state_lost[BBR_MAX_STAT];
422 counter_u64_t bbr_state_resend[BBR_MAX_STAT];
423 counter_u64_t bbr_stat_arry[BBR_STAT_SIZE];
424 counter_u64_t bbr_opts_arry[BBR_OPTS_SIZE];
425 counter_u64_t bbr_out_size[TCP_MSS_ACCT_SIZE];
426 counter_u64_t bbr_flows_whdwr_pacing;
427 counter_u64_t bbr_flows_nohdwr_pacing;
428
429 counter_u64_t bbr_nohdwr_pacing_enobuf;
430 counter_u64_t bbr_hdwr_pacing_enobuf;
431
432 static inline uint64_t bbr_get_bw(struct tcp_bbr *bbr);
433
434 /*
435 * Static defintions we need for forward declarations.
436 */
437 static uint32_t
438 bbr_get_pacing_length(struct tcp_bbr *bbr, uint16_t gain,
439 uint32_t useconds_time, uint64_t bw);
440 static uint32_t
441 bbr_get_a_state_target(struct tcp_bbr *bbr, uint32_t gain);
442 static void
443 bbr_set_state(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t win);
444 static void
445 bbr_set_probebw_gains(struct tcp_bbr *bbr, uint32_t cts, uint32_t losses);
446 static void
447 bbr_substate_change(struct tcp_bbr *bbr, uint32_t cts, int line,
448 int dolog);
449 static uint32_t
450 bbr_get_target_cwnd(struct tcp_bbr *bbr, uint64_t bw, uint32_t gain);
451 static void
452 bbr_state_change(struct tcp_bbr *bbr, uint32_t cts, int32_t epoch,
453 int32_t pkt_epoch, uint32_t losses);
454 static uint32_t
455 bbr_calc_thresh_rack(struct tcp_bbr *bbr, uint32_t srtt, uint32_t cts,
456 struct bbr_sendmap *rsm);
457 static uint32_t
458 bbr_initial_cwnd(struct tcp_bbr *bbr, struct tcpcb *tp);
459 static uint32_t
460 bbr_calc_thresh_tlp(struct tcpcb *tp, struct tcp_bbr *bbr,
461 struct bbr_sendmap *rsm, uint32_t srtt, uint32_t cts);
462 static void
463 bbr_exit_persist(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts,
464 int32_t line);
465 static void
466 bbr_set_state_target(struct tcp_bbr *bbr, int line);
467 static void
468 bbr_enter_probe_rtt(struct tcp_bbr *bbr, uint32_t cts, int32_t line);
469 static void
470 bbr_log_progress_event(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t tick,
471 int event, int line);
472 static void
473 tcp_bbr_tso_size_check(struct tcp_bbr *bbr, uint32_t cts);
474 static void
475 bbr_setup_red_bw(struct tcp_bbr *bbr, uint32_t cts);
476 static void
477 bbr_log_rtt_shrinks(struct tcp_bbr *bbr, uint32_t cts, uint32_t applied,
478 uint32_t rtt, uint32_t line, uint8_t is_start,
479 uint16_t set);
480 static struct bbr_sendmap *
481 bbr_find_lowest_rsm(struct tcp_bbr *bbr);
482 static __inline uint32_t
483 bbr_get_rtt(struct tcp_bbr *bbr, int32_t rtt_type);
484 static void
485 bbr_log_to_start(struct tcp_bbr *bbr, uint32_t cts, uint32_t to, int32_t slot,
486 uint8_t which);
487 static void
488 bbr_log_timer_var(struct tcp_bbr *bbr, int mode, uint32_t cts,
489 uint32_t time_since_sent, uint32_t srtt,
490 uint32_t thresh, uint32_t to);
491 static void
492 bbr_log_hpts_diag(struct tcp_bbr *bbr, uint32_t cts, struct hpts_diag *diag);
493 static void
494 bbr_log_type_bbrsnd(struct tcp_bbr *bbr, uint32_t len, uint32_t slot,
495 uint32_t del_by, uint32_t cts, uint32_t sloton,
496 uint32_t prev_delay);
497 static void
498 bbr_enter_persist(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts,
499 int32_t line);
500 static void
501 bbr_stop_all_timers(struct tcpcb *tp, struct tcp_bbr *bbr);
502 static void
503 bbr_exit_probe_rtt(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts);
504 static void
505 bbr_check_probe_rtt_limits(struct tcp_bbr *bbr, uint32_t cts);
506 static void
507 bbr_timer_cancel(struct tcp_bbr *bbr, int32_t line, uint32_t cts);
508 static void
509 bbr_log_pacing_delay_calc(struct tcp_bbr *bbr, uint16_t gain, uint32_t len,
510 uint32_t cts, uint32_t usecs, uint64_t bw,
511 uint32_t override, int mod);
512 static int bbr_ctloutput(struct tcpcb *tp, struct sockopt *sopt);
513
514 static inline uint8_t
bbr_state_val(struct tcp_bbr * bbr)515 bbr_state_val(struct tcp_bbr *bbr)
516 {
517 return(bbr->rc_bbr_substate);
518 }
519
520 static inline uint32_t
get_min_cwnd(struct tcp_bbr * bbr)521 get_min_cwnd(struct tcp_bbr *bbr)
522 {
523 int mss;
524
525 mss = min((bbr->rc_tp->t_maxseg - bbr->rc_last_options),
526 bbr->r_ctl.rc_pace_max_segs);
527 if (bbr_get_rtt(bbr, BBR_RTT_PROP) < BBR_HIGH_SPEED)
528 return (bbr_cwnd_min_val_hs * mss);
529 else
530 return (bbr_cwnd_min_val * mss);
531 }
532
533 static uint32_t
bbr_get_persists_timer_val(struct tcpcb * tp,struct tcp_bbr * bbr)534 bbr_get_persists_timer_val(struct tcpcb *tp, struct tcp_bbr *bbr)
535 {
536 uint64_t srtt, var;
537 uint64_t ret_val;
538
539 bbr->r_ctl.rc_hpts_flags |= PACE_TMR_PERSIT;
540 if (tp->t_srtt == 0) {
541 srtt = (uint64_t)BBR_INITIAL_RTO;
542 var = 0;
543 } else {
544 srtt = ((uint64_t)TICKS_2_USEC(tp->t_srtt) >> TCP_RTT_SHIFT);
545 var = ((uint64_t)TICKS_2_USEC(tp->t_rttvar) >> TCP_RTT_SHIFT);
546 }
547 TCPT_RANGESET_NOSLOP(ret_val, ((srtt + var) * tcp_backoff[tp->t_rxtshift]),
548 bbr_persist_min, bbr_persist_max);
549 return ((uint32_t)ret_val);
550 }
551
552 static uint32_t
bbr_timer_start(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)553 bbr_timer_start(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
554 {
555 /*
556 * Start the FR timer, we do this based on getting the first one in
557 * the rc_tmap. Note that if its NULL we must stop the timer. in all
558 * events we need to stop the running timer (if its running) before
559 * starting the new one.
560 */
561 uint32_t thresh, exp, to, srtt, time_since_sent, tstmp_touse;
562 int32_t idx;
563 int32_t is_tlp_timer = 0;
564 struct bbr_sendmap *rsm;
565
566 if (bbr->rc_all_timers_stopped) {
567 /* All timers have been stopped none are to run */
568 return (0);
569 }
570 if (bbr->rc_in_persist) {
571 /* We can't start any timer in persists */
572 return (bbr_get_persists_timer_val(tp, bbr));
573 }
574 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
575 if ((rsm == NULL) ||
576 ((tp->t_flags & TF_SACK_PERMIT) == 0) ||
577 (tp->t_state < TCPS_ESTABLISHED)) {
578 /* Nothing on the send map */
579 activate_rxt:
580 if (SEQ_LT(tp->snd_una, tp->snd_max) ||
581 sbavail(&tptosocket(tp)->so_snd)) {
582 uint64_t tov;
583
584 time_since_sent = 0;
585 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
586 if (rsm) {
587 idx = rsm->r_rtr_cnt - 1;
588 if (TSTMP_GEQ(rsm->r_tim_lastsent[idx], bbr->r_ctl.rc_tlp_rxt_last_time))
589 tstmp_touse = rsm->r_tim_lastsent[idx];
590 else
591 tstmp_touse = bbr->r_ctl.rc_tlp_rxt_last_time;
592 if (TSTMP_GT(tstmp_touse, cts))
593 time_since_sent = cts - tstmp_touse;
594 }
595 bbr->r_ctl.rc_hpts_flags |= PACE_TMR_RXT;
596 if (tp->t_srtt == 0)
597 tov = BBR_INITIAL_RTO;
598 else
599 tov = ((uint64_t)(TICKS_2_USEC(tp->t_srtt) +
600 ((uint64_t)TICKS_2_USEC(tp->t_rttvar) * (uint64_t)4)) >> TCP_RTT_SHIFT);
601 if (tp->t_rxtshift)
602 tov *= tcp_backoff[tp->t_rxtshift];
603 if (tov > time_since_sent)
604 tov -= time_since_sent;
605 else
606 tov = bbr->r_ctl.rc_min_to;
607 TCPT_RANGESET_NOSLOP(to, tov,
608 (bbr->r_ctl.rc_min_rto_ms * MS_IN_USEC),
609 (bbr->rc_max_rto_sec * USECS_IN_SECOND));
610 bbr_log_timer_var(bbr, 2, cts, 0, srtt, 0, to);
611 return (to);
612 }
613 return (0);
614 }
615 if (rsm->r_flags & BBR_ACKED) {
616 rsm = bbr_find_lowest_rsm(bbr);
617 if (rsm == NULL) {
618 /* No lowest? */
619 goto activate_rxt;
620 }
621 }
622 /* Convert from ms to usecs */
623 if (rsm->r_flags & BBR_SACK_PASSED) {
624 if ((tp->t_flags & TF_SENTFIN) &&
625 ((tp->snd_max - tp->snd_una) == 1) &&
626 (rsm->r_flags & BBR_HAS_FIN)) {
627 /*
628 * We don't start a bbr rack timer if all we have is
629 * a FIN outstanding.
630 */
631 goto activate_rxt;
632 }
633 srtt = bbr_get_rtt(bbr, BBR_RTT_RACK);
634 thresh = bbr_calc_thresh_rack(bbr, srtt, cts, rsm);
635 idx = rsm->r_rtr_cnt - 1;
636 exp = rsm->r_tim_lastsent[idx] + thresh;
637 if (SEQ_GEQ(exp, cts)) {
638 to = exp - cts;
639 if (to < bbr->r_ctl.rc_min_to) {
640 to = bbr->r_ctl.rc_min_to;
641 }
642 } else {
643 to = bbr->r_ctl.rc_min_to;
644 }
645 } else {
646 /* Ok we need to do a TLP not RACK */
647 if (bbr->rc_tlp_in_progress != 0) {
648 /*
649 * The previous send was a TLP.
650 */
651 goto activate_rxt;
652 }
653 rsm = TAILQ_LAST_FAST(&bbr->r_ctl.rc_tmap, bbr_sendmap, r_tnext);
654 if (rsm == NULL) {
655 /* We found no rsm to TLP with. */
656 goto activate_rxt;
657 }
658 if (rsm->r_flags & BBR_HAS_FIN) {
659 /* If its a FIN we don't do TLP */
660 rsm = NULL;
661 goto activate_rxt;
662 }
663 time_since_sent = 0;
664 idx = rsm->r_rtr_cnt - 1;
665 if (TSTMP_GEQ(rsm->r_tim_lastsent[idx], bbr->r_ctl.rc_tlp_rxt_last_time))
666 tstmp_touse = rsm->r_tim_lastsent[idx];
667 else
668 tstmp_touse = bbr->r_ctl.rc_tlp_rxt_last_time;
669 if (TSTMP_GT(tstmp_touse, cts))
670 time_since_sent = cts - tstmp_touse;
671 is_tlp_timer = 1;
672 srtt = bbr_get_rtt(bbr, bbr_tlp_type_to_use);
673 thresh = bbr_calc_thresh_tlp(tp, bbr, rsm, srtt, cts);
674 if (thresh > time_since_sent)
675 to = thresh - time_since_sent;
676 else
677 to = bbr->r_ctl.rc_min_to;
678 if (to > (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND)) {
679 /*
680 * If the TLP time works out to larger than the max
681 * RTO lets not do TLP.. just RTO.
682 */
683 goto activate_rxt;
684 }
685 if ((bbr->rc_tlp_rtx_out == 1) &&
686 (rsm->r_start == bbr->r_ctl.rc_last_tlp_seq)) {
687 /*
688 * Second retransmit of the same TLP
689 * lets not.
690 */
691 bbr->rc_tlp_rtx_out = 0;
692 goto activate_rxt;
693 }
694 if (rsm->r_start != bbr->r_ctl.rc_last_tlp_seq) {
695 /*
696 * The tail is no longer the last one I did a probe
697 * on
698 */
699 bbr->r_ctl.rc_tlp_seg_send_cnt = 0;
700 bbr->r_ctl.rc_last_tlp_seq = rsm->r_start;
701 }
702 }
703 if (is_tlp_timer == 0) {
704 BBR_STAT_INC(bbr_to_arm_rack);
705 bbr->r_ctl.rc_hpts_flags |= PACE_TMR_RACK;
706 } else {
707 bbr_log_timer_var(bbr, 1, cts, time_since_sent, srtt, thresh, to);
708 if (bbr->r_ctl.rc_tlp_seg_send_cnt > bbr_tlp_max_resend) {
709 /*
710 * We have exceeded how many times we can retran the
711 * current TLP timer, switch to the RTO timer.
712 */
713 goto activate_rxt;
714 } else {
715 BBR_STAT_INC(bbr_to_arm_tlp);
716 bbr->r_ctl.rc_hpts_flags |= PACE_TMR_TLP;
717 }
718 }
719 return (to);
720 }
721
722 static inline int32_t
bbr_minseg(struct tcp_bbr * bbr)723 bbr_minseg(struct tcp_bbr *bbr)
724 {
725 return (bbr->r_ctl.rc_pace_min_segs - bbr->rc_last_options);
726 }
727
728 static void
bbr_start_hpts_timer(struct tcp_bbr * bbr,struct tcpcb * tp,uint32_t cts,int32_t frm,int32_t slot,uint32_t tot_len)729 bbr_start_hpts_timer(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t cts, int32_t frm, int32_t slot, uint32_t tot_len)
730 {
731 struct inpcb *inp = tptoinpcb(tp);
732 struct hpts_diag diag;
733 uint32_t delayed_ack = 0;
734 uint32_t left = 0;
735 uint32_t hpts_timeout;
736 uint8_t stopped;
737 int32_t delay_calc = 0;
738 uint32_t prev_delay = 0;
739
740 if (tcp_in_hpts(tp)) {
741 /* A previous call is already set up */
742 return;
743 }
744 if ((tp->t_state == TCPS_CLOSED) ||
745 (tp->t_state == TCPS_LISTEN)) {
746 return;
747 }
748 stopped = bbr->rc_tmr_stopped;
749 if (stopped && TSTMP_GT(bbr->r_ctl.rc_timer_exp, cts)) {
750 left = bbr->r_ctl.rc_timer_exp - cts;
751 }
752 bbr->r_ctl.rc_hpts_flags = 0;
753 bbr->r_ctl.rc_timer_exp = 0;
754 prev_delay = bbr->r_ctl.rc_last_delay_val;
755 if (bbr->r_ctl.rc_last_delay_val &&
756 (slot == 0)) {
757 /*
758 * If a previous pacer delay was in place we
759 * are not coming from the output side (where
760 * we calculate a delay, more likely a timer).
761 */
762 slot = bbr->r_ctl.rc_last_delay_val;
763 if (TSTMP_GT(cts, bbr->rc_pacer_started)) {
764 /* Compensate for time passed */
765 delay_calc = cts - bbr->rc_pacer_started;
766 if (delay_calc <= slot)
767 slot -= delay_calc;
768 }
769 }
770 /* Do we have early to make up for by pushing out the pacing time? */
771 if (bbr->r_agg_early_set) {
772 bbr_log_pacing_delay_calc(bbr, 0, bbr->r_ctl.rc_agg_early, cts, slot, 0, bbr->r_agg_early_set, 2);
773 slot += bbr->r_ctl.rc_agg_early;
774 bbr->r_ctl.rc_agg_early = 0;
775 bbr->r_agg_early_set = 0;
776 }
777 /* Are we running a total debt that needs to be compensated for? */
778 if (bbr->r_ctl.rc_hptsi_agg_delay) {
779 if (slot > bbr->r_ctl.rc_hptsi_agg_delay) {
780 /* We nuke the delay */
781 slot -= bbr->r_ctl.rc_hptsi_agg_delay;
782 bbr->r_ctl.rc_hptsi_agg_delay = 0;
783 } else {
784 /* We nuke some of the delay, put in a minimal 100usecs */
785 bbr->r_ctl.rc_hptsi_agg_delay -= slot;
786 bbr->r_ctl.rc_last_delay_val = slot = 100;
787 }
788 }
789 bbr->r_ctl.rc_last_delay_val = slot;
790 hpts_timeout = bbr_timer_start(tp, bbr, cts);
791 if (tp->t_flags & TF_DELACK) {
792 if (bbr->rc_in_persist == 0) {
793 delayed_ack = bbr_delack_time;
794 } else {
795 /*
796 * We are in persists and have
797 * gotten a new data element.
798 */
799 if (hpts_timeout > bbr_delack_time) {
800 /*
801 * Lets make the persists timer (which acks)
802 * be the smaller of hpts_timeout and bbr_delack_time.
803 */
804 hpts_timeout = bbr_delack_time;
805 }
806 }
807 }
808 if (delayed_ack &&
809 ((hpts_timeout == 0) ||
810 (delayed_ack < hpts_timeout))) {
811 /* We need a Delayed ack timer */
812 bbr->r_ctl.rc_hpts_flags = PACE_TMR_DELACK;
813 hpts_timeout = delayed_ack;
814 }
815 if (slot) {
816 /* Mark that we have a pacing timer up */
817 BBR_STAT_INC(bbr_paced_segments);
818 bbr->r_ctl.rc_hpts_flags |= PACE_PKT_OUTPUT;
819 }
820 /*
821 * If no timers are going to run and we will fall off thfe hptsi
822 * wheel, we resort to a keep-alive timer if its configured.
823 */
824 if ((hpts_timeout == 0) &&
825 (slot == 0)) {
826 if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
827 (tp->t_state <= TCPS_CLOSING)) {
828 /*
829 * Ok we have no timer (persists, rack, tlp, rxt or
830 * del-ack), we don't have segments being paced. So
831 * all that is left is the keepalive timer.
832 */
833 if (TCPS_HAVEESTABLISHED(tp->t_state)) {
834 hpts_timeout = TICKS_2_USEC(TP_KEEPIDLE(tp));
835 } else {
836 hpts_timeout = TICKS_2_USEC(TP_KEEPINIT(tp));
837 }
838 bbr->r_ctl.rc_hpts_flags |= PACE_TMR_KEEP;
839 }
840 }
841 if (left && (stopped & (PACE_TMR_KEEP | PACE_TMR_DELACK)) ==
842 (bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK)) {
843 /*
844 * RACK, TLP, persists and RXT timers all are restartable
845 * based on actions input .. i.e we received a packet (ack
846 * or sack) and that changes things (rw, or snd_una etc).
847 * Thus we can restart them with a new value. For
848 * keep-alive, delayed_ack we keep track of what was left
849 * and restart the timer with a smaller value.
850 */
851 if (left < hpts_timeout)
852 hpts_timeout = left;
853 }
854 if (bbr->r_ctl.rc_incr_tmrs && slot &&
855 (bbr->r_ctl.rc_hpts_flags & (PACE_TMR_TLP|PACE_TMR_RXT))) {
856 /*
857 * If configured to do so, and the timer is either
858 * the TLP or RXT timer, we need to increase the timeout
859 * by the pacing time. Consider the bottleneck at my
860 * machine as an example, we are sending something
861 * to start a TLP on. The last packet won't be emitted
862 * fully until the pacing time (the bottleneck will hold
863 * the data in place). Once the packet is emitted that
864 * is when we want to start waiting for the TLP. This
865 * is most evident with hardware pacing (where the nic
866 * is holding the packet(s) before emitting). But it
867 * can also show up in the network so we do it for all
868 * cases. Technically we would take off one packet from
869 * this extra delay but this is easier and being more
870 * conservative is probably better.
871 */
872 hpts_timeout += slot;
873 }
874 if (hpts_timeout) {
875 /*
876 * Hack alert for now we can't time-out over 2147 seconds (a
877 * bit more than 35min)
878 */
879 if (hpts_timeout > 0x7ffffffe)
880 hpts_timeout = 0x7ffffffe;
881 bbr->r_ctl.rc_timer_exp = cts + hpts_timeout;
882 } else
883 bbr->r_ctl.rc_timer_exp = 0;
884 if ((slot) &&
885 (bbr->rc_use_google ||
886 bbr->output_error_seen ||
887 (slot <= hpts_timeout)) ) {
888 /*
889 * Tell LRO that it can queue packets while
890 * we pace.
891 */
892 bbr->rc_tp->t_flags2 |= TF2_MBUF_QUEUE_READY;
893 if ((bbr->r_ctl.rc_hpts_flags & PACE_TMR_RACK) &&
894 (bbr->rc_cwnd_limited == 0)) {
895 /*
896 * If we are not cwnd limited and we
897 * are running a rack timer we put on
898 * the do not disturbe even for sack.
899 */
900 tp->t_flags2 |= TF2_DONT_SACK_QUEUE;
901 } else
902 tp->t_flags2 &= ~TF2_DONT_SACK_QUEUE;
903 bbr->rc_pacer_started = cts;
904
905 (void)tcp_hpts_insert_diag(tp, HPTS_USEC_TO_SLOTS(slot),
906 __LINE__, &diag);
907 bbr->rc_timer_first = 0;
908 bbr->bbr_timer_src = frm;
909 bbr_log_to_start(bbr, cts, hpts_timeout, slot, 1);
910 bbr_log_hpts_diag(bbr, cts, &diag);
911 } else if (hpts_timeout) {
912 (void)tcp_hpts_insert_diag(tp, HPTS_USEC_TO_SLOTS(hpts_timeout),
913 __LINE__, &diag);
914 /*
915 * We add the flag here as well if the slot is set,
916 * since hpts will call in to clear the queue first before
917 * calling the output routine (which does our timers).
918 * We don't want to set the flag if its just a timer
919 * else the arrival of data might (that causes us
920 * to send more) might get delayed. Imagine being
921 * on a keep-alive timer and a request comes in for
922 * more data.
923 */
924 if (slot)
925 bbr->rc_pacer_started = cts;
926 if ((bbr->r_ctl.rc_hpts_flags & PACE_TMR_RACK) &&
927 (bbr->rc_cwnd_limited == 0)) {
928 /*
929 * For a rack timer, don't wake us even
930 * if a sack arrives as long as we are
931 * not cwnd limited.
932 */
933 tp->t_flags2 |= (TF2_MBUF_QUEUE_READY |
934 TF2_DONT_SACK_QUEUE);
935 } else {
936 /* All other timers wake us up */
937 tp->t_flags2 &= ~(TF2_MBUF_QUEUE_READY |
938 TF2_DONT_SACK_QUEUE);
939 }
940 bbr->bbr_timer_src = frm;
941 bbr_log_to_start(bbr, cts, hpts_timeout, slot, 0);
942 bbr_log_hpts_diag(bbr, cts, &diag);
943 bbr->rc_timer_first = 1;
944 }
945 bbr->rc_tmr_stopped = 0;
946 bbr_log_type_bbrsnd(bbr, tot_len, slot, delay_calc, cts, frm, prev_delay);
947 }
948
949 static void
bbr_timer_audit(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts,struct sockbuf * sb)950 bbr_timer_audit(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts, struct sockbuf *sb)
951 {
952 /*
953 * We received an ack, and then did not call send or were bounced
954 * out due to the hpts was running. Now a timer is up as well, is it
955 * the right timer?
956 */
957 struct inpcb *inp;
958 struct bbr_sendmap *rsm;
959 uint32_t hpts_timeout;
960 int tmr_up;
961
962 tmr_up = bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
963 if (bbr->rc_in_persist && (tmr_up == PACE_TMR_PERSIT))
964 return;
965 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
966 if (((rsm == NULL) || (tp->t_state < TCPS_ESTABLISHED)) &&
967 (tmr_up == PACE_TMR_RXT)) {
968 /* Should be an RXT */
969 return;
970 }
971 inp = bbr->rc_inp;
972 if (rsm == NULL) {
973 /* Nothing outstanding? */
974 if (tp->t_flags & TF_DELACK) {
975 if (tmr_up == PACE_TMR_DELACK)
976 /*
977 * We are supposed to have delayed ack up
978 * and we do
979 */
980 return;
981 } else if (sbavail(&inp->inp_socket->so_snd) &&
982 (tmr_up == PACE_TMR_RXT)) {
983 /*
984 * if we hit enobufs then we would expect the
985 * possibility of nothing outstanding and the RXT up
986 * (and the hptsi timer).
987 */
988 return;
989 } else if (((V_tcp_always_keepalive ||
990 inp->inp_socket->so_options & SO_KEEPALIVE) &&
991 (tp->t_state <= TCPS_CLOSING)) &&
992 (tmr_up == PACE_TMR_KEEP) &&
993 (tp->snd_max == tp->snd_una)) {
994 /* We should have keep alive up and we do */
995 return;
996 }
997 }
998 if (rsm && (rsm->r_flags & BBR_SACK_PASSED)) {
999 if ((tp->t_flags & TF_SENTFIN) &&
1000 ((tp->snd_max - tp->snd_una) == 1) &&
1001 (rsm->r_flags & BBR_HAS_FIN)) {
1002 /* needs to be a RXT */
1003 if (tmr_up == PACE_TMR_RXT)
1004 return;
1005 else
1006 goto wrong_timer;
1007 } else if (tmr_up == PACE_TMR_RACK)
1008 return;
1009 else
1010 goto wrong_timer;
1011 } else if (rsm && (tmr_up == PACE_TMR_RACK)) {
1012 /* Rack timer has priority if we have data out */
1013 return;
1014 } else if (SEQ_GT(tp->snd_max, tp->snd_una) &&
1015 ((tmr_up == PACE_TMR_TLP) ||
1016 (tmr_up == PACE_TMR_RXT))) {
1017 /*
1018 * Either a TLP or RXT is fine if no sack-passed is in place
1019 * and data is outstanding.
1020 */
1021 return;
1022 } else if (tmr_up == PACE_TMR_DELACK) {
1023 /*
1024 * If the delayed ack was going to go off before the
1025 * rtx/tlp/rack timer were going to expire, then that would
1026 * be the timer in control. Note we don't check the time
1027 * here trusting the code is correct.
1028 */
1029 return;
1030 }
1031 if (SEQ_GT(tp->snd_max, tp->snd_una) &&
1032 ((tmr_up == PACE_TMR_RXT) ||
1033 (tmr_up == PACE_TMR_TLP) ||
1034 (tmr_up == PACE_TMR_RACK))) {
1035 /*
1036 * We have outstanding data and
1037 * we *do* have a RACK, TLP or RXT
1038 * timer running. We won't restart
1039 * anything here since thats probably ok we
1040 * will get called with some timer here shortly.
1041 */
1042 return;
1043 }
1044 /*
1045 * Ok the timer originally started is not what we want now. We will
1046 * force the hpts to be stopped if any, and restart with the slot
1047 * set to what was in the saved slot.
1048 */
1049 wrong_timer:
1050 if ((bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) {
1051 if (tcp_in_hpts(tp))
1052 tcp_hpts_remove(tp);
1053 bbr_timer_cancel(bbr, __LINE__, cts);
1054 bbr_start_hpts_timer(bbr, tp, cts, 1, bbr->r_ctl.rc_last_delay_val,
1055 0);
1056 } else {
1057 /*
1058 * Output is hptsi so we just need to switch the type of
1059 * timer. We don't bother with keep-alive, since when we
1060 * jump through the output, it will start the keep-alive if
1061 * nothing is sent.
1062 *
1063 * We only need a delayed-ack added and or the hpts_timeout.
1064 */
1065 hpts_timeout = bbr_timer_start(tp, bbr, cts);
1066 if (tp->t_flags & TF_DELACK) {
1067 if (hpts_timeout == 0) {
1068 hpts_timeout = bbr_delack_time;
1069 bbr->r_ctl.rc_hpts_flags = PACE_TMR_DELACK;
1070 }
1071 else if (hpts_timeout > bbr_delack_time) {
1072 hpts_timeout = bbr_delack_time;
1073 bbr->r_ctl.rc_hpts_flags = PACE_TMR_DELACK;
1074 }
1075 }
1076 if (hpts_timeout) {
1077 if (hpts_timeout > 0x7ffffffe)
1078 hpts_timeout = 0x7ffffffe;
1079 bbr->r_ctl.rc_timer_exp = cts + hpts_timeout;
1080 }
1081 }
1082 }
1083
1084 int32_t bbr_clear_lost = 0;
1085
1086 /*
1087 * Considers the two time values now (cts) and earlier.
1088 * If cts is smaller than earlier, we could have
1089 * had a sequence wrap (our counter wraps every
1090 * 70 min or so) or it could be just clock skew
1091 * getting us two different time values. Clock skew
1092 * will show up within 10ms or so. So in such
1093 * a case (where cts is behind earlier time by
1094 * less than 10ms) we return 0. Otherwise we
1095 * return the true difference between them.
1096 */
1097 static inline uint32_t
bbr_calc_time(uint32_t cts,uint32_t earlier_time)1098 bbr_calc_time(uint32_t cts, uint32_t earlier_time) {
1099 /*
1100 * Given two timestamps, the current time stamp cts, and some other
1101 * time-stamp taken in theory earlier return the difference. The
1102 * trick is here sometimes locking will get the other timestamp
1103 * after the cts. If this occurs we need to return 0.
1104 */
1105 if (TSTMP_GEQ(cts, earlier_time))
1106 return (cts - earlier_time);
1107 /*
1108 * cts is behind earlier_time if its less than 10ms consider it 0.
1109 * If its more than 10ms difference then we had a time wrap. Else
1110 * its just the normal locking foo. I wonder if we should not go to
1111 * 64bit TS and get rid of this issue.
1112 */
1113 if (TSTMP_GEQ((cts + 10000), earlier_time))
1114 return (0);
1115 /*
1116 * Ok the time must have wrapped. So we need to answer a large
1117 * amount of time, which the normal subtraction should do.
1118 */
1119 return (cts - earlier_time);
1120 }
1121
1122 static int
sysctl_bbr_clear_lost(SYSCTL_HANDLER_ARGS)1123 sysctl_bbr_clear_lost(SYSCTL_HANDLER_ARGS)
1124 {
1125 uint32_t stat;
1126 int32_t error;
1127
1128 error = SYSCTL_OUT(req, &bbr_clear_lost, sizeof(uint32_t));
1129 if (error || req->newptr == NULL)
1130 return error;
1131
1132 error = SYSCTL_IN(req, &stat, sizeof(uint32_t));
1133 if (error)
1134 return (error);
1135 if (stat == 1) {
1136 #ifdef BBR_INVARIANTS
1137 printf("Clearing BBR lost counters\n");
1138 #endif
1139 COUNTER_ARRAY_ZERO(bbr_state_lost, BBR_MAX_STAT);
1140 COUNTER_ARRAY_ZERO(bbr_state_time, BBR_MAX_STAT);
1141 COUNTER_ARRAY_ZERO(bbr_state_resend, BBR_MAX_STAT);
1142 } else if (stat == 2) {
1143 #ifdef BBR_INVARIANTS
1144 printf("Clearing BBR option counters\n");
1145 #endif
1146 COUNTER_ARRAY_ZERO(bbr_opts_arry, BBR_OPTS_SIZE);
1147 } else if (stat == 3) {
1148 #ifdef BBR_INVARIANTS
1149 printf("Clearing BBR stats counters\n");
1150 #endif
1151 COUNTER_ARRAY_ZERO(bbr_stat_arry, BBR_STAT_SIZE);
1152 } else if (stat == 4) {
1153 #ifdef BBR_INVARIANTS
1154 printf("Clearing BBR out-size counters\n");
1155 #endif
1156 COUNTER_ARRAY_ZERO(bbr_out_size, TCP_MSS_ACCT_SIZE);
1157 }
1158 bbr_clear_lost = 0;
1159 return (0);
1160 }
1161
1162 static void
bbr_init_sysctls(void)1163 bbr_init_sysctls(void)
1164 {
1165 struct sysctl_oid *bbr_probertt;
1166 struct sysctl_oid *bbr_hptsi;
1167 struct sysctl_oid *bbr_measure;
1168 struct sysctl_oid *bbr_cwnd;
1169 struct sysctl_oid *bbr_timeout;
1170 struct sysctl_oid *bbr_states;
1171 struct sysctl_oid *bbr_startup;
1172 struct sysctl_oid *bbr_policer;
1173
1174 /* Probe rtt controls */
1175 bbr_probertt = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1176 SYSCTL_CHILDREN(bbr_sysctl_root),
1177 OID_AUTO,
1178 "probertt",
1179 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1180 "");
1181 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1182 SYSCTL_CHILDREN(bbr_probertt),
1183 OID_AUTO, "gain", CTLFLAG_RW,
1184 &bbr_rttprobe_gain, 192,
1185 "What is the filter gain drop in probe_rtt (0=disable)?");
1186 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1187 SYSCTL_CHILDREN(bbr_probertt),
1188 OID_AUTO, "cwnd", CTLFLAG_RW,
1189 &bbr_rtt_probe_cwndtarg, 4,
1190 "How many mss's are outstanding during probe-rtt");
1191 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1192 SYSCTL_CHILDREN(bbr_probertt),
1193 OID_AUTO, "int", CTLFLAG_RW,
1194 &bbr_rtt_probe_limit, 4000000,
1195 "If RTT has not shrank in this many micro-seconds enter probe-rtt");
1196 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1197 SYSCTL_CHILDREN(bbr_probertt),
1198 OID_AUTO, "mintime", CTLFLAG_RW,
1199 &bbr_rtt_probe_time, 200000,
1200 "How many microseconds in probe-rtt");
1201 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1202 SYSCTL_CHILDREN(bbr_probertt),
1203 OID_AUTO, "filter_len_sec", CTLFLAG_RW,
1204 &bbr_filter_len_sec, 6,
1205 "How long in seconds does the rttProp filter run?");
1206 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1207 SYSCTL_CHILDREN(bbr_probertt),
1208 OID_AUTO, "drain_rtt", CTLFLAG_RW,
1209 &bbr_drain_rtt, BBR_SRTT,
1210 "What is the drain rtt to use in probeRTT (rtt_prop=0, rtt_rack=1, rtt_pkt=2, rtt_srtt=3?");
1211 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1212 SYSCTL_CHILDREN(bbr_probertt),
1213 OID_AUTO, "can_force", CTLFLAG_RW,
1214 &bbr_can_force_probertt, 0,
1215 "If we keep setting new low rtt's but delay going in probe-rtt can we force in??");
1216 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1217 SYSCTL_CHILDREN(bbr_probertt),
1218 OID_AUTO, "enter_sets_force", CTLFLAG_RW,
1219 &bbr_probertt_sets_rtt, 0,
1220 "In NF mode, do we imitate google_mode and set the rttProp on entry to probe-rtt?");
1221 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1222 SYSCTL_CHILDREN(bbr_probertt),
1223 OID_AUTO, "can_adjust", CTLFLAG_RW,
1224 &bbr_can_adjust_probertt, 1,
1225 "Can we dynamically adjust the probe-rtt limits and times?");
1226 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1227 SYSCTL_CHILDREN(bbr_probertt),
1228 OID_AUTO, "is_ratio", CTLFLAG_RW,
1229 &bbr_is_ratio, 0,
1230 "is the limit to filter a ratio?");
1231 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1232 SYSCTL_CHILDREN(bbr_probertt),
1233 OID_AUTO, "use_cwnd", CTLFLAG_RW,
1234 &bbr_prtt_slam_cwnd, 0,
1235 "Should we set/recover cwnd?");
1236 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1237 SYSCTL_CHILDREN(bbr_probertt),
1238 OID_AUTO, "can_use_ts", CTLFLAG_RW,
1239 &bbr_can_use_ts_for_rtt, 1,
1240 "Can we use the ms timestamp if available for retransmistted rtt calculations?");
1241
1242 /* Pacing controls */
1243 bbr_hptsi = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1244 SYSCTL_CHILDREN(bbr_sysctl_root),
1245 OID_AUTO,
1246 "pacing",
1247 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1248 "");
1249 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1250 SYSCTL_CHILDREN(bbr_hptsi),
1251 OID_AUTO, "hw_pacing", CTLFLAG_RW,
1252 &bbr_allow_hdwr_pacing, 1,
1253 "Do we allow hardware pacing?");
1254 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1255 SYSCTL_CHILDREN(bbr_hptsi),
1256 OID_AUTO, "hw_pacing_limit", CTLFLAG_RW,
1257 &bbr_hardware_pacing_limit, 4000,
1258 "Do we have a limited number of connections for pacing chelsio (0=no limit)?");
1259 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1260 SYSCTL_CHILDREN(bbr_hptsi),
1261 OID_AUTO, "hw_pacing_adj", CTLFLAG_RW,
1262 &bbr_hdwr_pace_adjust, 2,
1263 "Multiplier to calculated tso size?");
1264 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1265 SYSCTL_CHILDREN(bbr_hptsi),
1266 OID_AUTO, "hw_pacing_floor", CTLFLAG_RW,
1267 &bbr_hdwr_pace_floor, 1,
1268 "Do we invoke the hardware pacing floor?");
1269 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1270 SYSCTL_CHILDREN(bbr_hptsi),
1271 OID_AUTO, "hw_pacing_delay_cnt", CTLFLAG_RW,
1272 &bbr_hdwr_pacing_delay_cnt, 10,
1273 "How many packets must be sent after hdwr pacing is enabled");
1274 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1275 SYSCTL_CHILDREN(bbr_hptsi),
1276 OID_AUTO, "bw_cross", CTLFLAG_RW,
1277 &bbr_cross_over, 3000000,
1278 "What is the point where we cross over to linux like TSO size set");
1279 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1280 SYSCTL_CHILDREN(bbr_hptsi),
1281 OID_AUTO, "seg_deltarg", CTLFLAG_RW,
1282 &bbr_hptsi_segments_delay_tar, 7000,
1283 "What is the worse case delay target for hptsi < 48Mbp connections");
1284 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1285 SYSCTL_CHILDREN(bbr_hptsi),
1286 OID_AUTO, "enet_oh", CTLFLAG_RW,
1287 &bbr_include_enet_oh, 0,
1288 "Do we include the ethernet overhead in calculating pacing delay?");
1289 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1290 SYSCTL_CHILDREN(bbr_hptsi),
1291 OID_AUTO, "ip_oh", CTLFLAG_RW,
1292 &bbr_include_ip_oh, 1,
1293 "Do we include the IP overhead in calculating pacing delay?");
1294 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1295 SYSCTL_CHILDREN(bbr_hptsi),
1296 OID_AUTO, "tcp_oh", CTLFLAG_RW,
1297 &bbr_include_tcp_oh, 0,
1298 "Do we include the TCP overhead in calculating pacing delay?");
1299 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1300 SYSCTL_CHILDREN(bbr_hptsi),
1301 OID_AUTO, "google_discount", CTLFLAG_RW,
1302 &bbr_google_discount, 10,
1303 "What is the default google discount percentage wise for pacing (11 = 1.1%%)?");
1304 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1305 SYSCTL_CHILDREN(bbr_hptsi),
1306 OID_AUTO, "all_get_min", CTLFLAG_RW,
1307 &bbr_all_get_min, 0,
1308 "If you are less than a MSS do you just get the min?");
1309 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1310 SYSCTL_CHILDREN(bbr_hptsi),
1311 OID_AUTO, "tso_min", CTLFLAG_RW,
1312 &bbr_hptsi_bytes_min, 1460,
1313 "For 0 -> 24Mbps what is floor number of segments for TSO");
1314 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1315 SYSCTL_CHILDREN(bbr_hptsi),
1316 OID_AUTO, "seg_tso_max", CTLFLAG_RW,
1317 &bbr_hptsi_segments_max, 6,
1318 "For 0 -> 24Mbps what is top number of segments for TSO");
1319 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1320 SYSCTL_CHILDREN(bbr_hptsi),
1321 OID_AUTO, "seg_floor", CTLFLAG_RW,
1322 &bbr_hptsi_segments_floor, 1,
1323 "Minimum TSO size we will fall too in segments");
1324 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1325 SYSCTL_CHILDREN(bbr_hptsi),
1326 OID_AUTO, "utter_max", CTLFLAG_RW,
1327 &bbr_hptsi_utter_max, 0,
1328 "The absolute maximum that any pacing (outside of hardware) can be");
1329 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1330 SYSCTL_CHILDREN(bbr_hptsi),
1331 OID_AUTO, "seg_divisor", CTLFLAG_RW,
1332 &bbr_hptsi_per_second, 100,
1333 "What is the divisor in our hptsi TSO calculation 512Mbps < X > 24Mbps ");
1334 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1335 SYSCTL_CHILDREN(bbr_hptsi),
1336 OID_AUTO, "srtt_mul", CTLFLAG_RW,
1337 &bbr_hptsi_max_mul, 1,
1338 "The multiplier for pace len max");
1339 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1340 SYSCTL_CHILDREN(bbr_hptsi),
1341 OID_AUTO, "srtt_div", CTLFLAG_RW,
1342 &bbr_hptsi_max_div, 2,
1343 "The divisor for pace len max");
1344 /* Measurement controls */
1345 bbr_measure = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1346 SYSCTL_CHILDREN(bbr_sysctl_root),
1347 OID_AUTO,
1348 "measure",
1349 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1350 "Measurement controls");
1351 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1352 SYSCTL_CHILDREN(bbr_measure),
1353 OID_AUTO, "min_i_bw", CTLFLAG_RW,
1354 &bbr_initial_bw_bps, 62500,
1355 "Minimum initial b/w in bytes per second");
1356 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1357 SYSCTL_CHILDREN(bbr_measure),
1358 OID_AUTO, "no_sack_needed", CTLFLAG_RW,
1359 &bbr_sack_not_required, 0,
1360 "Do we allow bbr to run on connections not supporting SACK?");
1361 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1362 SYSCTL_CHILDREN(bbr_measure),
1363 OID_AUTO, "use_google", CTLFLAG_RW,
1364 &bbr_use_google_algo, 0,
1365 "Use has close to google V1.0 has possible?");
1366 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1367 SYSCTL_CHILDREN(bbr_measure),
1368 OID_AUTO, "ts_limiting", CTLFLAG_RW,
1369 &bbr_ts_limiting, 1,
1370 "Do we attempt to use the peers timestamp to limit b/w caculations?");
1371 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1372 SYSCTL_CHILDREN(bbr_measure),
1373 OID_AUTO, "ts_can_raise", CTLFLAG_RW,
1374 &bbr_ts_can_raise, 0,
1375 "Can we raise the b/w via timestamp b/w calculation?");
1376 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1377 SYSCTL_CHILDREN(bbr_measure),
1378 OID_AUTO, "ts_delta", CTLFLAG_RW,
1379 &bbr_min_usec_delta, 20000,
1380 "How long in usec between ts of our sends in ts validation code?");
1381 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1382 SYSCTL_CHILDREN(bbr_measure),
1383 OID_AUTO, "ts_peer_delta", CTLFLAG_RW,
1384 &bbr_min_peer_delta, 20,
1385 "What min numerical value should be between the peer deltas?");
1386 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1387 SYSCTL_CHILDREN(bbr_measure),
1388 OID_AUTO, "ts_delta_percent", CTLFLAG_RW,
1389 &bbr_delta_percent, 150,
1390 "What percentage (150 = 15.0) do we allow variance for?");
1391 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1392 SYSCTL_CHILDREN(bbr_measure),
1393 OID_AUTO, "min_measure_good_bw", CTLFLAG_RW,
1394 &bbr_min_measurements_req, 1,
1395 "What is the minimum measurement count we need before we switch to our b/w estimate");
1396 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1397 SYSCTL_CHILDREN(bbr_measure),
1398 OID_AUTO, "min_measure_before_pace", CTLFLAG_RW,
1399 &bbr_no_pacing_until, 4,
1400 "How many pkt-epoch's (0 is off) do we need before pacing is on?");
1401 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1402 SYSCTL_CHILDREN(bbr_measure),
1403 OID_AUTO, "quanta", CTLFLAG_RW,
1404 &bbr_quanta, 2,
1405 "Extra quanta to add when calculating the target (ID section 4.2.3.2).");
1406 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1407 SYSCTL_CHILDREN(bbr_measure),
1408 OID_AUTO, "noretran", CTLFLAG_RW,
1409 &bbr_no_retran, 0,
1410 "Should google mode not use retransmission measurements for the b/w estimation?");
1411 /* State controls */
1412 bbr_states = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1413 SYSCTL_CHILDREN(bbr_sysctl_root),
1414 OID_AUTO,
1415 "states",
1416 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1417 "State controls");
1418 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1419 SYSCTL_CHILDREN(bbr_states),
1420 OID_AUTO, "idle_restart", CTLFLAG_RW,
1421 &bbr_uses_idle_restart, 0,
1422 "Do we use a new special idle_restart state to ramp back up quickly?");
1423 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1424 SYSCTL_CHILDREN(bbr_states),
1425 OID_AUTO, "idle_restart_threshold", CTLFLAG_RW,
1426 &bbr_idle_restart_threshold, 100000,
1427 "How long must we be idle before we restart??");
1428 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1429 SYSCTL_CHILDREN(bbr_states),
1430 OID_AUTO, "use_pkt_epoch", CTLFLAG_RW,
1431 &bbr_state_is_pkt_epoch, 0,
1432 "Do we use a pkt-epoch for substate if 0 rttProp?");
1433 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1434 SYSCTL_CHILDREN(bbr_states),
1435 OID_AUTO, "startup_rtt_gain", CTLFLAG_RW,
1436 &bbr_rtt_gain_thresh, 0,
1437 "What increase in RTT triggers us to stop ignoring no-loss and possibly exit startup?");
1438 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1439 SYSCTL_CHILDREN(bbr_states),
1440 OID_AUTO, "drain_floor", CTLFLAG_RW,
1441 &bbr_drain_floor, 88,
1442 "What is the lowest we can drain (pg) too?");
1443 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1444 SYSCTL_CHILDREN(bbr_states),
1445 OID_AUTO, "drain_2_target", CTLFLAG_RW,
1446 &bbr_state_drain_2_tar, 1,
1447 "Do we drain to target in drain substate?");
1448 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1449 SYSCTL_CHILDREN(bbr_states),
1450 OID_AUTO, "gain_2_target", CTLFLAG_RW,
1451 &bbr_gain_to_target, 1,
1452 "Does probe bw gain to target??");
1453 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1454 SYSCTL_CHILDREN(bbr_states),
1455 OID_AUTO, "gain_extra_time", CTLFLAG_RW,
1456 &bbr_gain_gets_extra_too, 1,
1457 "Does probe bw gain get the extra time too?");
1458 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1459 SYSCTL_CHILDREN(bbr_states),
1460 OID_AUTO, "ld_div", CTLFLAG_RW,
1461 &bbr_drain_drop_div, 5,
1462 "Long drain drop divider?");
1463 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1464 SYSCTL_CHILDREN(bbr_states),
1465 OID_AUTO, "ld_mul", CTLFLAG_RW,
1466 &bbr_drain_drop_mul, 4,
1467 "Long drain drop multiplier?");
1468 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1469 SYSCTL_CHILDREN(bbr_states),
1470 OID_AUTO, "rand_ot_disc", CTLFLAG_RW,
1471 &bbr_rand_ot, 50,
1472 "Random discount of the ot?");
1473 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1474 SYSCTL_CHILDREN(bbr_states),
1475 OID_AUTO, "dr_filter_life", CTLFLAG_RW,
1476 &bbr_num_pktepo_for_del_limit, BBR_NUM_RTTS_FOR_DEL_LIMIT,
1477 "How many packet-epochs does the b/w delivery rate last?");
1478 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1479 SYSCTL_CHILDREN(bbr_states),
1480 OID_AUTO, "subdrain_applimited", CTLFLAG_RW,
1481 &bbr_sub_drain_app_limit, 0,
1482 "Does our sub-state drain invoke app limited if its long?");
1483 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1484 SYSCTL_CHILDREN(bbr_states),
1485 OID_AUTO, "use_cwnd_subdrain", CTLFLAG_RW,
1486 &bbr_sub_drain_slam_cwnd, 0,
1487 "Should we set/recover cwnd for sub-state drain?");
1488 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1489 SYSCTL_CHILDREN(bbr_states),
1490 OID_AUTO, "use_cwnd_maindrain", CTLFLAG_RW,
1491 &bbr_slam_cwnd_in_main_drain, 0,
1492 "Should we set/recover cwnd for main-state drain?");
1493 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1494 SYSCTL_CHILDREN(bbr_states),
1495 OID_AUTO, "google_gets_earlyout", CTLFLAG_RW,
1496 &google_allow_early_out, 1,
1497 "Should we allow google probe-bw/drain to exit early at flight target?");
1498 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1499 SYSCTL_CHILDREN(bbr_states),
1500 OID_AUTO, "google_exit_loss", CTLFLAG_RW,
1501 &google_consider_lost, 1,
1502 "Should we have losses exit gain of probebw in google mode??");
1503 /* Startup controls */
1504 bbr_startup = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1505 SYSCTL_CHILDREN(bbr_sysctl_root),
1506 OID_AUTO,
1507 "startup",
1508 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1509 "Startup controls");
1510 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1511 SYSCTL_CHILDREN(bbr_startup),
1512 OID_AUTO, "cheat_iwnd", CTLFLAG_RW,
1513 &bbr_sends_full_iwnd, 1,
1514 "Do we not pace but burst out initial windows has our TSO size?");
1515 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1516 SYSCTL_CHILDREN(bbr_startup),
1517 OID_AUTO, "loss_threshold", CTLFLAG_RW,
1518 &bbr_startup_loss_thresh, 2000,
1519 "In startup what is the loss threshold in a pe that will exit us from startup?");
1520 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1521 SYSCTL_CHILDREN(bbr_startup),
1522 OID_AUTO, "use_lowerpg", CTLFLAG_RW,
1523 &bbr_use_lower_gain_in_startup, 1,
1524 "Should we use a lower hptsi gain if we see loss in startup?");
1525 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1526 SYSCTL_CHILDREN(bbr_startup),
1527 OID_AUTO, "gain", CTLFLAG_RW,
1528 &bbr_start_exit, 25,
1529 "What gain percent do we need to see to stay in startup??");
1530 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1531 SYSCTL_CHILDREN(bbr_startup),
1532 OID_AUTO, "low_gain", CTLFLAG_RW,
1533 &bbr_low_start_exit, 15,
1534 "What gain percent do we need to see to stay in the lower gain startup??");
1535 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1536 SYSCTL_CHILDREN(bbr_startup),
1537 OID_AUTO, "loss_exit", CTLFLAG_RW,
1538 &bbr_exit_startup_at_loss, 1,
1539 "Should we exit startup at loss in an epoch if we are not gaining?");
1540 /* CWND controls */
1541 bbr_cwnd = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1542 SYSCTL_CHILDREN(bbr_sysctl_root),
1543 OID_AUTO,
1544 "cwnd",
1545 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1546 "Cwnd controls");
1547 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1548 SYSCTL_CHILDREN(bbr_cwnd),
1549 OID_AUTO, "tar_rtt", CTLFLAG_RW,
1550 &bbr_cwndtarget_rtt_touse, 0,
1551 "Target cwnd rtt measurement to use (0=rtt_prop, 1=rtt_rack, 2=pkt_rtt, 3=srtt)?");
1552 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1553 SYSCTL_CHILDREN(bbr_cwnd),
1554 OID_AUTO, "may_shrink", CTLFLAG_RW,
1555 &bbr_cwnd_may_shrink, 0,
1556 "Can the cwnd shrink if it would grow to more than the target?");
1557 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1558 SYSCTL_CHILDREN(bbr_cwnd),
1559 OID_AUTO, "max_target_limit", CTLFLAG_RW,
1560 &bbr_target_cwnd_mult_limit, 8,
1561 "Do we limit the cwnd to some multiple of the cwnd target if cwnd can't shrink 0=no?");
1562 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1563 SYSCTL_CHILDREN(bbr_cwnd),
1564 OID_AUTO, "highspeed_min", CTLFLAG_RW,
1565 &bbr_cwnd_min_val_hs, BBR_HIGHSPEED_NUM_MSS,
1566 "What is the high-speed min cwnd (rttProp under 1ms)");
1567 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1568 SYSCTL_CHILDREN(bbr_cwnd),
1569 OID_AUTO, "lowspeed_min", CTLFLAG_RW,
1570 &bbr_cwnd_min_val, BBR_PROBERTT_NUM_MSS,
1571 "What is the min cwnd (rttProp > 1ms)");
1572 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1573 SYSCTL_CHILDREN(bbr_cwnd),
1574 OID_AUTO, "initwin", CTLFLAG_RW,
1575 &bbr_def_init_win, 10,
1576 "What is the BBR initial window, if 0 use tcp version");
1577 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1578 SYSCTL_CHILDREN(bbr_cwnd),
1579 OID_AUTO, "do_loss_red", CTLFLAG_RW,
1580 &bbr_do_red, 600,
1581 "Do we reduce the b/w at exit from recovery based on ratio of prop/srtt (800=80.0, 0=off)?");
1582 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1583 SYSCTL_CHILDREN(bbr_cwnd),
1584 OID_AUTO, "red_scale", CTLFLAG_RW,
1585 &bbr_red_scale, 20000,
1586 "What RTT do we scale with?");
1587 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1588 SYSCTL_CHILDREN(bbr_cwnd),
1589 OID_AUTO, "red_growslow", CTLFLAG_RW,
1590 &bbr_red_growth_restrict, 1,
1591 "Do we restrict cwnd growth for whats in flight?");
1592 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1593 SYSCTL_CHILDREN(bbr_cwnd),
1594 OID_AUTO, "red_div", CTLFLAG_RW,
1595 &bbr_red_div, 2,
1596 "If we reduce whats the divisor?");
1597 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1598 SYSCTL_CHILDREN(bbr_cwnd),
1599 OID_AUTO, "red_mul", CTLFLAG_RW,
1600 &bbr_red_mul, 1,
1601 "If we reduce whats the mulitiplier?");
1602 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1603 SYSCTL_CHILDREN(bbr_cwnd),
1604 OID_AUTO, "target_is_unit", CTLFLAG_RW,
1605 &bbr_target_is_bbunit, 0,
1606 "Is the state target the pacing_gain or BBR_UNIT?");
1607 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1608 SYSCTL_CHILDREN(bbr_cwnd),
1609 OID_AUTO, "drop_limit", CTLFLAG_RW,
1610 &bbr_drop_limit, 0,
1611 "Number of segments limit for drop (0=use min_cwnd w/flight)?");
1612
1613 /* Timeout controls */
1614 bbr_timeout = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1615 SYSCTL_CHILDREN(bbr_sysctl_root),
1616 OID_AUTO,
1617 "timeout",
1618 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1619 "Time out controls");
1620 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1621 SYSCTL_CHILDREN(bbr_timeout),
1622 OID_AUTO, "delack", CTLFLAG_RW,
1623 &bbr_delack_time, 100000,
1624 "BBR's delayed ack time");
1625 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1626 SYSCTL_CHILDREN(bbr_timeout),
1627 OID_AUTO, "tlp_uses", CTLFLAG_RW,
1628 &bbr_tlp_type_to_use, 3,
1629 "RTT that TLP uses in its calculations, 0=rttProp, 1=Rack_rtt, 2=pkt_rtt and 3=srtt");
1630 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1631 SYSCTL_CHILDREN(bbr_timeout),
1632 OID_AUTO, "persmin", CTLFLAG_RW,
1633 &bbr_persist_min, 250000,
1634 "What is the minimum time in microseconds between persists");
1635 SYSCTL_ADD_U32(&bbr_sysctl_ctx,
1636 SYSCTL_CHILDREN(bbr_timeout),
1637 OID_AUTO, "persmax", CTLFLAG_RW,
1638 &bbr_persist_max, 1000000,
1639 "What is the largest delay in microseconds between persists");
1640 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1641 SYSCTL_CHILDREN(bbr_timeout),
1642 OID_AUTO, "tlp_minto", CTLFLAG_RW,
1643 &bbr_tlp_min, 10000,
1644 "TLP Min timeout in usecs");
1645 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1646 SYSCTL_CHILDREN(bbr_timeout),
1647 OID_AUTO, "tlp_dack_time", CTLFLAG_RW,
1648 &bbr_delayed_ack_time, 200000,
1649 "TLP delayed ack compensation value");
1650 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1651 SYSCTL_CHILDREN(bbr_sysctl_root),
1652 OID_AUTO, "minrto", CTLFLAG_RW,
1653 &bbr_rto_min_ms, 30,
1654 "Minimum RTO in ms");
1655 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1656 SYSCTL_CHILDREN(bbr_timeout),
1657 OID_AUTO, "maxrto", CTLFLAG_RW,
1658 &bbr_rto_max_sec, 4,
1659 "Maximum RTO in seconds -- should be at least as large as min_rto");
1660 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1661 SYSCTL_CHILDREN(bbr_timeout),
1662 OID_AUTO, "tlp_retry", CTLFLAG_RW,
1663 &bbr_tlp_max_resend, 2,
1664 "How many times does TLP retry a single segment or multiple with no ACK");
1665 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1666 SYSCTL_CHILDREN(bbr_timeout),
1667 OID_AUTO, "minto", CTLFLAG_RW,
1668 &bbr_min_to, 1000,
1669 "Minimum rack timeout in useconds");
1670 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1671 SYSCTL_CHILDREN(bbr_timeout),
1672 OID_AUTO, "pktdelay", CTLFLAG_RW,
1673 &bbr_pkt_delay, 1000,
1674 "Extra RACK time (in useconds) besides reordering thresh");
1675 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1676 SYSCTL_CHILDREN(bbr_timeout),
1677 OID_AUTO, "incr_tmrs", CTLFLAG_RW,
1678 &bbr_incr_timers, 1,
1679 "Increase the RXT/TLP timer by the pacing time used?");
1680 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1681 SYSCTL_CHILDREN(bbr_timeout),
1682 OID_AUTO, "rxtmark_sackpassed", CTLFLAG_RW,
1683 &bbr_marks_rxt_sack_passed, 0,
1684 "Mark sack passed on all those not ack'd when a RXT hits?");
1685 /* Policer controls */
1686 bbr_policer = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
1687 SYSCTL_CHILDREN(bbr_sysctl_root),
1688 OID_AUTO,
1689 "policer",
1690 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1691 "Policer controls");
1692 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1693 SYSCTL_CHILDREN(bbr_policer),
1694 OID_AUTO, "detect_enable", CTLFLAG_RW,
1695 &bbr_policer_detection_enabled, 1,
1696 "Is policer detection enabled??");
1697 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1698 SYSCTL_CHILDREN(bbr_policer),
1699 OID_AUTO, "min_pes", CTLFLAG_RW,
1700 &bbr_lt_intvl_min_rtts, 4,
1701 "Minimum number of PE's?");
1702 SYSCTL_ADD_U64(&bbr_sysctl_ctx,
1703 SYSCTL_CHILDREN(bbr_policer),
1704 OID_AUTO, "bwdiff", CTLFLAG_RW,
1705 &bbr_lt_bw_diff, (4000/8),
1706 "Minimal bw diff?");
1707 SYSCTL_ADD_U64(&bbr_sysctl_ctx,
1708 SYSCTL_CHILDREN(bbr_policer),
1709 OID_AUTO, "bwratio", CTLFLAG_RW,
1710 &bbr_lt_bw_ratio, 8,
1711 "Minimal bw diff?");
1712 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1713 SYSCTL_CHILDREN(bbr_policer),
1714 OID_AUTO, "from_rack_rxt", CTLFLAG_RW,
1715 &bbr_policer_call_from_rack_to, 0,
1716 "Do we call the policer detection code from a rack-timeout?");
1717 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1718 SYSCTL_CHILDREN(bbr_policer),
1719 OID_AUTO, "false_postive", CTLFLAG_RW,
1720 &bbr_lt_intvl_fp, 0,
1721 "What packet epoch do we do false-positive detection at (0=no)?");
1722 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1723 SYSCTL_CHILDREN(bbr_policer),
1724 OID_AUTO, "loss_thresh", CTLFLAG_RW,
1725 &bbr_lt_loss_thresh, 196,
1726 "Loss threshold 196 = 19.6%?");
1727 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1728 SYSCTL_CHILDREN(bbr_policer),
1729 OID_AUTO, "false_postive_thresh", CTLFLAG_RW,
1730 &bbr_lt_fd_thresh, 100,
1731 "What percentage is the false detection threshold (150=15.0)?");
1732 /* All the rest */
1733 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1734 SYSCTL_CHILDREN(bbr_sysctl_root),
1735 OID_AUTO, "cheat_rxt", CTLFLAG_RW,
1736 &bbr_use_rack_resend_cheat, 0,
1737 "Do we burst 1ms between sends on retransmissions (like rack)?");
1738 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1739 SYSCTL_CHILDREN(bbr_sysctl_root),
1740 OID_AUTO, "error_paceout", CTLFLAG_RW,
1741 &bbr_error_base_paceout, 10000,
1742 "When we hit an error what is the min to pace out in usec's?");
1743 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1744 SYSCTL_CHILDREN(bbr_sysctl_root),
1745 OID_AUTO, "kill_paceout", CTLFLAG_RW,
1746 &bbr_max_net_error_cnt, 10,
1747 "When we hit this many errors in a row, kill the session?");
1748 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1749 SYSCTL_CHILDREN(bbr_sysctl_root),
1750 OID_AUTO, "data_after_close", CTLFLAG_RW,
1751 &bbr_ignore_data_after_close, 1,
1752 "Do we hold off sending a RST until all pending data is ack'd");
1753 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1754 SYSCTL_CHILDREN(bbr_sysctl_root),
1755 OID_AUTO, "resend_use_tso", CTLFLAG_RW,
1756 &bbr_resends_use_tso, 0,
1757 "Can resends use TSO?");
1758 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1759 SYSCTL_CHILDREN(bbr_sysctl_root),
1760 OID_AUTO, "sblklimit", CTLFLAG_RW,
1761 &bbr_sack_block_limit, 128,
1762 "When do we start ignoring small sack blocks");
1763 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1764 SYSCTL_CHILDREN(bbr_sysctl_root),
1765 OID_AUTO, "bb_verbose", CTLFLAG_RW,
1766 &bbr_verbose_logging, 0,
1767 "Should BBR black box logging be verbose");
1768 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1769 SYSCTL_CHILDREN(bbr_sysctl_root),
1770 OID_AUTO, "reorder_thresh", CTLFLAG_RW,
1771 &bbr_reorder_thresh, 2,
1772 "What factor for rack will be added when seeing reordering (shift right)");
1773 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1774 SYSCTL_CHILDREN(bbr_sysctl_root),
1775 OID_AUTO, "reorder_fade", CTLFLAG_RW,
1776 &bbr_reorder_fade, 0,
1777 "Does reorder detection fade, if so how many ms (0 means never)");
1778 SYSCTL_ADD_S32(&bbr_sysctl_ctx,
1779 SYSCTL_CHILDREN(bbr_sysctl_root),
1780 OID_AUTO, "rtt_tlp_thresh", CTLFLAG_RW,
1781 &bbr_tlp_thresh, 1,
1782 "what divisor for TLP rtt/retran will be added (1=rtt, 2=1/2 rtt etc)");
1783 /* Stats and counters */
1784 /* The pacing counters for hdwr/software can't be in the array */
1785 bbr_nohdwr_pacing_enobuf = counter_u64_alloc(M_WAITOK);
1786 bbr_hdwr_pacing_enobuf = counter_u64_alloc(M_WAITOK);
1787 SYSCTL_ADD_COUNTER_U64(&bbr_sysctl_ctx,
1788 SYSCTL_CHILDREN(bbr_sysctl_root),
1789 OID_AUTO, "enob_hdwr_pacing", CTLFLAG_RD,
1790 &bbr_hdwr_pacing_enobuf,
1791 "Total number of enobufs for hardware paced flows");
1792 SYSCTL_ADD_COUNTER_U64(&bbr_sysctl_ctx,
1793 SYSCTL_CHILDREN(bbr_sysctl_root),
1794 OID_AUTO, "enob_no_hdwr_pacing", CTLFLAG_RD,
1795 &bbr_nohdwr_pacing_enobuf,
1796 "Total number of enobufs for non-hardware paced flows");
1797
1798 bbr_flows_whdwr_pacing = counter_u64_alloc(M_WAITOK);
1799 SYSCTL_ADD_COUNTER_U64(&bbr_sysctl_ctx,
1800 SYSCTL_CHILDREN(bbr_sysctl_root),
1801 OID_AUTO, "hdwr_pacing", CTLFLAG_RD,
1802 &bbr_flows_whdwr_pacing,
1803 "Total number of hardware paced flows");
1804 bbr_flows_nohdwr_pacing = counter_u64_alloc(M_WAITOK);
1805 SYSCTL_ADD_COUNTER_U64(&bbr_sysctl_ctx,
1806 SYSCTL_CHILDREN(bbr_sysctl_root),
1807 OID_AUTO, "software_pacing", CTLFLAG_RD,
1808 &bbr_flows_nohdwr_pacing,
1809 "Total number of software paced flows");
1810 COUNTER_ARRAY_ALLOC(bbr_stat_arry, BBR_STAT_SIZE, M_WAITOK);
1811 SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
1812 OID_AUTO, "stats", CTLFLAG_RD,
1813 bbr_stat_arry, BBR_STAT_SIZE, "BBR Stats");
1814 COUNTER_ARRAY_ALLOC(bbr_opts_arry, BBR_OPTS_SIZE, M_WAITOK);
1815 SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
1816 OID_AUTO, "opts", CTLFLAG_RD,
1817 bbr_opts_arry, BBR_OPTS_SIZE, "BBR Option Stats");
1818 COUNTER_ARRAY_ALLOC(bbr_state_lost, BBR_MAX_STAT, M_WAITOK);
1819 SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
1820 OID_AUTO, "lost", CTLFLAG_RD,
1821 bbr_state_lost, BBR_MAX_STAT, "Stats of when losses occur");
1822 COUNTER_ARRAY_ALLOC(bbr_state_resend, BBR_MAX_STAT, M_WAITOK);
1823 SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
1824 OID_AUTO, "stateresend", CTLFLAG_RD,
1825 bbr_state_resend, BBR_MAX_STAT, "Stats of what states resend");
1826 COUNTER_ARRAY_ALLOC(bbr_state_time, BBR_MAX_STAT, M_WAITOK);
1827 SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
1828 OID_AUTO, "statetime", CTLFLAG_RD,
1829 bbr_state_time, BBR_MAX_STAT, "Stats of time spent in the states");
1830 COUNTER_ARRAY_ALLOC(bbr_out_size, TCP_MSS_ACCT_SIZE, M_WAITOK);
1831 SYSCTL_ADD_COUNTER_U64_ARRAY(&bbr_sysctl_ctx, SYSCTL_CHILDREN(bbr_sysctl_root),
1832 OID_AUTO, "outsize", CTLFLAG_RD,
1833 bbr_out_size, TCP_MSS_ACCT_SIZE, "Size of output calls");
1834 SYSCTL_ADD_PROC(&bbr_sysctl_ctx,
1835 SYSCTL_CHILDREN(bbr_sysctl_root),
1836 OID_AUTO, "clrlost", CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE,
1837 &bbr_clear_lost, 0, sysctl_bbr_clear_lost, "IU", "Clear lost counters");
1838 }
1839
1840 static void
bbr_counter_destroy(void)1841 bbr_counter_destroy(void)
1842 {
1843 COUNTER_ARRAY_FREE(bbr_stat_arry, BBR_STAT_SIZE);
1844 COUNTER_ARRAY_FREE(bbr_opts_arry, BBR_OPTS_SIZE);
1845 COUNTER_ARRAY_FREE(bbr_out_size, TCP_MSS_ACCT_SIZE);
1846 COUNTER_ARRAY_FREE(bbr_state_lost, BBR_MAX_STAT);
1847 COUNTER_ARRAY_FREE(bbr_state_time, BBR_MAX_STAT);
1848 COUNTER_ARRAY_FREE(bbr_state_resend, BBR_MAX_STAT);
1849 counter_u64_free(bbr_nohdwr_pacing_enobuf);
1850 counter_u64_free(bbr_hdwr_pacing_enobuf);
1851 counter_u64_free(bbr_flows_whdwr_pacing);
1852 counter_u64_free(bbr_flows_nohdwr_pacing);
1853
1854 }
1855
1856 static __inline void
bbr_fill_in_logging_data(struct tcp_bbr * bbr,struct tcp_log_bbr * l,uint32_t cts)1857 bbr_fill_in_logging_data(struct tcp_bbr *bbr, struct tcp_log_bbr *l, uint32_t cts)
1858 {
1859 memset(l, 0, sizeof(union tcp_log_stackspecific));
1860 l->cur_del_rate = bbr->r_ctl.rc_bbr_cur_del_rate;
1861 l->delRate = get_filter_value(&bbr->r_ctl.rc_delrate);
1862 l->rttProp = get_filter_value_small(&bbr->r_ctl.rc_rttprop);
1863 l->bw_inuse = bbr_get_bw(bbr);
1864 l->inflight = ctf_flight_size(bbr->rc_tp,
1865 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
1866 l->applimited = bbr->r_ctl.r_app_limited_until;
1867 l->delivered = bbr->r_ctl.rc_delivered;
1868 l->timeStamp = cts;
1869 l->lost = bbr->r_ctl.rc_lost;
1870 l->bbr_state = bbr->rc_bbr_state;
1871 l->bbr_substate = bbr_state_val(bbr);
1872 l->epoch = bbr->r_ctl.rc_rtt_epoch;
1873 l->lt_epoch = bbr->r_ctl.rc_lt_epoch;
1874 l->pacing_gain = bbr->r_ctl.rc_bbr_hptsi_gain;
1875 l->cwnd_gain = bbr->r_ctl.rc_bbr_cwnd_gain;
1876 l->inhpts = tcp_in_hpts(bbr->rc_tp);
1877 l->use_lt_bw = bbr->rc_lt_use_bw;
1878 l->pkts_out = bbr->r_ctl.rc_flight_at_input;
1879 l->pkt_epoch = bbr->r_ctl.rc_pkt_epoch;
1880 }
1881
1882 static void
bbr_log_type_bw_reduce(struct tcp_bbr * bbr,int reason)1883 bbr_log_type_bw_reduce(struct tcp_bbr *bbr, int reason)
1884 {
1885 if (tcp_bblogging_on(bbr->rc_tp)) {
1886 union tcp_log_stackspecific log;
1887
1888 bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
1889 log.u_bbr.flex1 = 0;
1890 log.u_bbr.flex2 = 0;
1891 log.u_bbr.flex5 = 0;
1892 log.u_bbr.flex3 = 0;
1893 log.u_bbr.flex4 = bbr->r_ctl.rc_pkt_epoch_loss_rate;
1894 log.u_bbr.flex7 = reason;
1895 log.u_bbr.flex6 = bbr->r_ctl.rc_bbr_enters_probertt;
1896 log.u_bbr.flex8 = 0;
1897 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
1898 &bbr->rc_inp->inp_socket->so_rcv,
1899 &bbr->rc_inp->inp_socket->so_snd,
1900 BBR_LOG_BW_RED_EV, 0,
1901 0, &log, false, &bbr->rc_tv);
1902 }
1903 }
1904
1905 static void
bbr_log_type_rwnd_collapse(struct tcp_bbr * bbr,int seq,int mode,uint32_t count)1906 bbr_log_type_rwnd_collapse(struct tcp_bbr *bbr, int seq, int mode, uint32_t count)
1907 {
1908 if (tcp_bblogging_on(bbr->rc_tp)) {
1909 union tcp_log_stackspecific log;
1910
1911 bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
1912 log.u_bbr.flex1 = seq;
1913 log.u_bbr.flex2 = count;
1914 log.u_bbr.flex8 = mode;
1915 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
1916 &bbr->rc_inp->inp_socket->so_rcv,
1917 &bbr->rc_inp->inp_socket->so_snd,
1918 BBR_LOG_LOWGAIN, 0,
1919 0, &log, false, &bbr->rc_tv);
1920 }
1921 }
1922
1923 static void
bbr_log_type_just_return(struct tcp_bbr * bbr,uint32_t cts,uint32_t tlen,uint8_t hpts_calling,uint8_t reason,uint32_t p_maxseg,int len)1924 bbr_log_type_just_return(struct tcp_bbr *bbr, uint32_t cts, uint32_t tlen, uint8_t hpts_calling,
1925 uint8_t reason, uint32_t p_maxseg, int len)
1926 {
1927 if (tcp_bblogging_on(bbr->rc_tp)) {
1928 union tcp_log_stackspecific log;
1929
1930 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
1931 log.u_bbr.flex1 = p_maxseg;
1932 log.u_bbr.flex2 = bbr->r_ctl.rc_hpts_flags;
1933 log.u_bbr.flex3 = bbr->r_ctl.rc_timer_exp;
1934 log.u_bbr.flex4 = reason;
1935 log.u_bbr.flex5 = bbr->rc_in_persist;
1936 log.u_bbr.flex6 = bbr->r_ctl.rc_last_delay_val;
1937 log.u_bbr.flex7 = p_maxseg;
1938 log.u_bbr.flex8 = bbr->rc_in_persist;
1939 log.u_bbr.pkts_out = 0;
1940 log.u_bbr.applimited = len;
1941 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
1942 &bbr->rc_inp->inp_socket->so_rcv,
1943 &bbr->rc_inp->inp_socket->so_snd,
1944 BBR_LOG_JUSTRET, 0,
1945 tlen, &log, false, &bbr->rc_tv);
1946 }
1947 }
1948
1949 static void
bbr_log_type_enter_rec(struct tcp_bbr * bbr,uint32_t seq)1950 bbr_log_type_enter_rec(struct tcp_bbr *bbr, uint32_t seq)
1951 {
1952 if (tcp_bblogging_on(bbr->rc_tp)) {
1953 union tcp_log_stackspecific log;
1954
1955 bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
1956 log.u_bbr.flex1 = seq;
1957 log.u_bbr.flex2 = bbr->r_ctl.rc_cwnd_on_ent;
1958 log.u_bbr.flex3 = bbr->r_ctl.rc_recovery_start;
1959 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
1960 &bbr->rc_inp->inp_socket->so_rcv,
1961 &bbr->rc_inp->inp_socket->so_snd,
1962 BBR_LOG_ENTREC, 0,
1963 0, &log, false, &bbr->rc_tv);
1964 }
1965 }
1966
1967 static void
bbr_log_msgsize_fail(struct tcp_bbr * bbr,struct tcpcb * tp,uint32_t len,uint32_t maxseg,uint32_t mtu,int32_t csum_flags,int32_t tso,uint32_t cts)1968 bbr_log_msgsize_fail(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t len, uint32_t maxseg, uint32_t mtu, int32_t csum_flags, int32_t tso, uint32_t cts)
1969 {
1970 if (tcp_bblogging_on(tp)) {
1971 union tcp_log_stackspecific log;
1972
1973 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
1974 log.u_bbr.flex1 = tso;
1975 log.u_bbr.flex2 = maxseg;
1976 log.u_bbr.flex3 = mtu;
1977 log.u_bbr.flex4 = csum_flags;
1978 TCP_LOG_EVENTP(tp, NULL,
1979 &bbr->rc_inp->inp_socket->so_rcv,
1980 &bbr->rc_inp->inp_socket->so_snd,
1981 BBR_LOG_MSGSIZE, 0,
1982 0, &log, false, &bbr->rc_tv);
1983 }
1984 }
1985
1986 static void
bbr_log_flowend(struct tcp_bbr * bbr)1987 bbr_log_flowend(struct tcp_bbr *bbr)
1988 {
1989 if (tcp_bblogging_on(bbr->rc_tp)) {
1990 union tcp_log_stackspecific log;
1991 struct sockbuf *r, *s;
1992 struct timeval tv;
1993
1994 if (bbr->rc_inp->inp_socket) {
1995 r = &bbr->rc_inp->inp_socket->so_rcv;
1996 s = &bbr->rc_inp->inp_socket->so_snd;
1997 } else {
1998 r = s = NULL;
1999 }
2000 bbr_fill_in_logging_data(bbr, &log.u_bbr, tcp_get_usecs(&tv));
2001 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2002 r, s,
2003 TCP_LOG_FLOWEND, 0,
2004 0, &log, false, &tv);
2005 }
2006 }
2007
2008 static void
bbr_log_pkt_epoch(struct tcp_bbr * bbr,uint32_t cts,uint32_t line,uint32_t lost,uint32_t del)2009 bbr_log_pkt_epoch(struct tcp_bbr *bbr, uint32_t cts, uint32_t line,
2010 uint32_t lost, uint32_t del)
2011 {
2012 if (tcp_bblogging_on(bbr->rc_tp)) {
2013 union tcp_log_stackspecific log;
2014
2015 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2016 log.u_bbr.flex1 = lost;
2017 log.u_bbr.flex2 = del;
2018 log.u_bbr.flex3 = bbr->r_ctl.rc_bbr_lastbtlbw;
2019 log.u_bbr.flex4 = bbr->r_ctl.rc_pkt_epoch_rtt;
2020 log.u_bbr.flex5 = bbr->r_ctl.rc_bbr_last_startup_epoch;
2021 log.u_bbr.flex6 = bbr->r_ctl.rc_lost_at_startup;
2022 log.u_bbr.flex7 = line;
2023 log.u_bbr.flex8 = 0;
2024 log.u_bbr.inflight = bbr->r_ctl.r_measurement_count;
2025 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2026 &bbr->rc_inp->inp_socket->so_rcv,
2027 &bbr->rc_inp->inp_socket->so_snd,
2028 BBR_LOG_PKT_EPOCH, 0,
2029 0, &log, false, &bbr->rc_tv);
2030 }
2031 }
2032
2033 static void
bbr_log_time_epoch(struct tcp_bbr * bbr,uint32_t cts,uint32_t line,uint32_t epoch_time)2034 bbr_log_time_epoch(struct tcp_bbr *bbr, uint32_t cts, uint32_t line, uint32_t epoch_time)
2035 {
2036 if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2037 union tcp_log_stackspecific log;
2038
2039 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2040 log.u_bbr.flex1 = bbr->r_ctl.rc_lost;
2041 log.u_bbr.flex2 = bbr->rc_inp->inp_socket->so_snd.sb_lowat;
2042 log.u_bbr.flex3 = bbr->rc_inp->inp_socket->so_snd.sb_hiwat;
2043 log.u_bbr.flex7 = line;
2044 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2045 &bbr->rc_inp->inp_socket->so_rcv,
2046 &bbr->rc_inp->inp_socket->so_snd,
2047 BBR_LOG_TIME_EPOCH, 0,
2048 0, &log, false, &bbr->rc_tv);
2049 }
2050 }
2051
2052 static void
bbr_log_set_of_state_target(struct tcp_bbr * bbr,uint32_t new_tar,int line,int meth)2053 bbr_log_set_of_state_target(struct tcp_bbr *bbr, uint32_t new_tar, int line, int meth)
2054 {
2055 if (tcp_bblogging_on(bbr->rc_tp)) {
2056 union tcp_log_stackspecific log;
2057
2058 bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2059 log.u_bbr.flex1 = bbr->r_ctl.rc_target_at_state;
2060 log.u_bbr.flex2 = new_tar;
2061 log.u_bbr.flex3 = line;
2062 log.u_bbr.flex4 = bbr->r_ctl.rc_pace_max_segs;
2063 log.u_bbr.flex5 = bbr_quanta;
2064 log.u_bbr.flex6 = bbr->r_ctl.rc_pace_min_segs;
2065 log.u_bbr.flex7 = bbr->rc_last_options;
2066 log.u_bbr.flex8 = meth;
2067 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2068 &bbr->rc_inp->inp_socket->so_rcv,
2069 &bbr->rc_inp->inp_socket->so_snd,
2070 BBR_LOG_STATE_TARGET, 0,
2071 0, &log, false, &bbr->rc_tv);
2072 }
2073
2074 }
2075
2076 static void
bbr_log_type_statechange(struct tcp_bbr * bbr,uint32_t cts,int32_t line)2077 bbr_log_type_statechange(struct tcp_bbr *bbr, uint32_t cts, int32_t line)
2078 {
2079 if (tcp_bblogging_on(bbr->rc_tp)) {
2080 union tcp_log_stackspecific log;
2081
2082 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2083 log.u_bbr.flex1 = line;
2084 log.u_bbr.flex2 = bbr->r_ctl.rc_rtt_shrinks;
2085 log.u_bbr.flex3 = bbr->r_ctl.rc_probertt_int;
2086 if (bbr_state_is_pkt_epoch)
2087 log.u_bbr.flex4 = bbr_get_rtt(bbr, BBR_RTT_PKTRTT);
2088 else
2089 log.u_bbr.flex4 = bbr_get_rtt(bbr, BBR_RTT_PROP);
2090 log.u_bbr.flex5 = bbr->r_ctl.rc_bbr_last_startup_epoch;
2091 log.u_bbr.flex6 = bbr->r_ctl.rc_lost_at_startup;
2092 log.u_bbr.flex7 = (bbr->r_ctl.rc_target_at_state/1000);
2093 log.u_bbr.lt_epoch = bbr->r_ctl.rc_level_state_extra;
2094 log.u_bbr.pkts_out = bbr->r_ctl.rc_target_at_state;
2095 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2096 &bbr->rc_inp->inp_socket->so_rcv,
2097 &bbr->rc_inp->inp_socket->so_snd,
2098 BBR_LOG_STATE, 0,
2099 0, &log, false, &bbr->rc_tv);
2100 }
2101 }
2102
2103 static void
bbr_log_rtt_shrinks(struct tcp_bbr * bbr,uint32_t cts,uint32_t applied,uint32_t rtt,uint32_t line,uint8_t reas,uint16_t cond)2104 bbr_log_rtt_shrinks(struct tcp_bbr *bbr, uint32_t cts, uint32_t applied,
2105 uint32_t rtt, uint32_t line, uint8_t reas, uint16_t cond)
2106 {
2107 if (tcp_bblogging_on(bbr->rc_tp)) {
2108 union tcp_log_stackspecific log;
2109
2110 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2111 log.u_bbr.flex1 = line;
2112 log.u_bbr.flex2 = bbr->r_ctl.rc_rtt_shrinks;
2113 log.u_bbr.flex3 = bbr->r_ctl.last_in_probertt;
2114 log.u_bbr.flex4 = applied;
2115 log.u_bbr.flex5 = rtt;
2116 log.u_bbr.flex6 = bbr->r_ctl.rc_target_at_state;
2117 log.u_bbr.flex7 = cond;
2118 log.u_bbr.flex8 = reas;
2119 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2120 &bbr->rc_inp->inp_socket->so_rcv,
2121 &bbr->rc_inp->inp_socket->so_snd,
2122 BBR_LOG_RTT_SHRINKS, 0,
2123 0, &log, false, &bbr->rc_tv);
2124 }
2125 }
2126
2127 static void
bbr_log_type_exit_rec(struct tcp_bbr * bbr)2128 bbr_log_type_exit_rec(struct tcp_bbr *bbr)
2129 {
2130 if (tcp_bblogging_on(bbr->rc_tp)) {
2131 union tcp_log_stackspecific log;
2132
2133 bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2134 log.u_bbr.flex1 = bbr->r_ctl.rc_recovery_start;
2135 log.u_bbr.flex2 = bbr->r_ctl.rc_cwnd_on_ent;
2136 log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
2137 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2138 &bbr->rc_inp->inp_socket->so_rcv,
2139 &bbr->rc_inp->inp_socket->so_snd,
2140 BBR_LOG_EXITREC, 0,
2141 0, &log, false, &bbr->rc_tv);
2142 }
2143 }
2144
2145 static void
bbr_log_type_cwndupd(struct tcp_bbr * bbr,uint32_t bytes_this_ack,uint32_t chg,uint32_t prev_acked,int32_t meth,uint32_t target,uint32_t th_ack,int32_t line)2146 bbr_log_type_cwndupd(struct tcp_bbr *bbr, uint32_t bytes_this_ack, uint32_t chg,
2147 uint32_t prev_acked, int32_t meth, uint32_t target, uint32_t th_ack, int32_t line)
2148 {
2149 if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2150 union tcp_log_stackspecific log;
2151
2152 bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2153 log.u_bbr.flex1 = line;
2154 log.u_bbr.flex2 = prev_acked;
2155 log.u_bbr.flex3 = bytes_this_ack;
2156 log.u_bbr.flex4 = chg;
2157 log.u_bbr.flex5 = th_ack;
2158 log.u_bbr.flex6 = target;
2159 log.u_bbr.flex8 = meth;
2160 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2161 &bbr->rc_inp->inp_socket->so_rcv,
2162 &bbr->rc_inp->inp_socket->so_snd,
2163 BBR_LOG_CWND, 0,
2164 0, &log, false, &bbr->rc_tv);
2165 }
2166 }
2167
2168 static void
bbr_log_rtt_sample(struct tcp_bbr * bbr,uint32_t rtt,uint32_t tsin)2169 bbr_log_rtt_sample(struct tcp_bbr *bbr, uint32_t rtt, uint32_t tsin)
2170 {
2171 /*
2172 * Log the rtt sample we are applying to the srtt algorithm in
2173 * useconds.
2174 */
2175 if (tcp_bblogging_on(bbr->rc_tp)) {
2176 union tcp_log_stackspecific log;
2177
2178 bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2179 log.u_bbr.flex1 = rtt;
2180 log.u_bbr.flex2 = bbr->r_ctl.rc_bbr_state_time;
2181 log.u_bbr.flex3 = bbr->r_ctl.rc_ack_hdwr_delay;
2182 log.u_bbr.flex4 = bbr->rc_tp->ts_offset;
2183 log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
2184 log.u_bbr.pkts_out = tcp_tv_to_mssectick(&bbr->rc_tv);
2185 log.u_bbr.flex6 = tsin;
2186 log.u_bbr.flex7 = 0;
2187 log.u_bbr.flex8 = bbr->rc_ack_was_delayed;
2188 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2189 &bbr->rc_inp->inp_socket->so_rcv,
2190 &bbr->rc_inp->inp_socket->so_snd,
2191 TCP_LOG_RTT, 0,
2192 0, &log, false, &bbr->rc_tv);
2193 }
2194 }
2195
2196 static void
bbr_log_type_pesist(struct tcp_bbr * bbr,uint32_t cts,uint32_t time_in,int32_t line,uint8_t enter_exit)2197 bbr_log_type_pesist(struct tcp_bbr *bbr, uint32_t cts, uint32_t time_in, int32_t line, uint8_t enter_exit)
2198 {
2199 if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2200 union tcp_log_stackspecific log;
2201
2202 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2203 log.u_bbr.flex1 = time_in;
2204 log.u_bbr.flex2 = line;
2205 log.u_bbr.flex8 = enter_exit;
2206 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2207 &bbr->rc_inp->inp_socket->so_rcv,
2208 &bbr->rc_inp->inp_socket->so_snd,
2209 BBR_LOG_PERSIST, 0,
2210 0, &log, false, &bbr->rc_tv);
2211 }
2212 }
2213 static void
bbr_log_ack_clear(struct tcp_bbr * bbr,uint32_t cts)2214 bbr_log_ack_clear(struct tcp_bbr *bbr, uint32_t cts)
2215 {
2216 if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2217 union tcp_log_stackspecific log;
2218
2219 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2220 log.u_bbr.flex1 = bbr->rc_tp->ts_recent_age;
2221 log.u_bbr.flex2 = bbr->r_ctl.rc_rtt_shrinks;
2222 log.u_bbr.flex3 = bbr->r_ctl.rc_probertt_int;
2223 log.u_bbr.flex4 = bbr->r_ctl.rc_went_idle_time;
2224 log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
2225 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2226 &bbr->rc_inp->inp_socket->so_rcv,
2227 &bbr->rc_inp->inp_socket->so_snd,
2228 BBR_LOG_ACKCLEAR, 0,
2229 0, &log, false, &bbr->rc_tv);
2230 }
2231 }
2232
2233 static void
bbr_log_ack_event(struct tcp_bbr * bbr,struct tcphdr * th,struct tcpopt * to,uint32_t tlen,uint16_t nsegs,uint32_t cts,int32_t nxt_pkt,struct mbuf * m)2234 bbr_log_ack_event(struct tcp_bbr *bbr, struct tcphdr *th, struct tcpopt *to, uint32_t tlen,
2235 uint16_t nsegs, uint32_t cts, int32_t nxt_pkt, struct mbuf *m)
2236 {
2237 if (tcp_bblogging_on(bbr->rc_tp)) {
2238 union tcp_log_stackspecific log;
2239 struct timeval tv;
2240
2241 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2242 log.u_bbr.flex1 = nsegs;
2243 log.u_bbr.flex2 = bbr->r_ctl.rc_lost_bytes;
2244 if (m) {
2245 struct timespec ts;
2246
2247 log.u_bbr.flex3 = m->m_flags;
2248 if (m->m_flags & M_TSTMP) {
2249 mbuf_tstmp2timespec(m, &ts);
2250 tv.tv_sec = ts.tv_sec;
2251 tv.tv_usec = ts.tv_nsec / 1000;
2252 log.u_bbr.lt_epoch = tcp_tv_to_usectick(&tv);
2253 } else {
2254 log.u_bbr.lt_epoch = 0;
2255 }
2256 if (m->m_flags & M_TSTMP_LRO) {
2257 mbuf_tstmp2timeval(m, &tv);
2258 log.u_bbr.flex5 = tcp_tv_to_usectick(&tv);
2259 } else {
2260 /* No arrival timestamp */
2261 log.u_bbr.flex5 = 0;
2262 }
2263
2264 log.u_bbr.pkts_out = tcp_get_usecs(&tv);
2265 } else {
2266 log.u_bbr.flex3 = 0;
2267 log.u_bbr.flex5 = 0;
2268 log.u_bbr.flex6 = 0;
2269 log.u_bbr.pkts_out = 0;
2270 }
2271 log.u_bbr.flex4 = bbr->r_ctl.rc_target_at_state;
2272 log.u_bbr.flex7 = bbr->r_wanted_output;
2273 log.u_bbr.flex8 = bbr->rc_in_persist;
2274 TCP_LOG_EVENTP(bbr->rc_tp, th,
2275 &bbr->rc_inp->inp_socket->so_rcv,
2276 &bbr->rc_inp->inp_socket->so_snd,
2277 TCP_LOG_IN, 0,
2278 tlen, &log, true, &bbr->rc_tv);
2279 }
2280 }
2281
2282 static void
bbr_log_doseg_done(struct tcp_bbr * bbr,uint32_t cts,int32_t nxt_pkt,int32_t did_out)2283 bbr_log_doseg_done(struct tcp_bbr *bbr, uint32_t cts, int32_t nxt_pkt, int32_t did_out)
2284 {
2285 if (tcp_bblogging_on(bbr->rc_tp)) {
2286 union tcp_log_stackspecific log;
2287
2288 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2289 log.u_bbr.flex1 = did_out;
2290 log.u_bbr.flex2 = nxt_pkt;
2291 log.u_bbr.flex3 = bbr->r_ctl.rc_last_delay_val;
2292 log.u_bbr.flex4 = bbr->r_ctl.rc_hpts_flags;
2293 log.u_bbr.flex5 = bbr->r_ctl.rc_timer_exp;
2294 log.u_bbr.flex6 = bbr->r_ctl.rc_lost_bytes;
2295 log.u_bbr.flex7 = bbr->r_wanted_output;
2296 log.u_bbr.flex8 = bbr->rc_in_persist;
2297 log.u_bbr.pkts_out = bbr->r_ctl.highest_hdwr_delay;
2298 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2299 &bbr->rc_inp->inp_socket->so_rcv,
2300 &bbr->rc_inp->inp_socket->so_snd,
2301 BBR_LOG_DOSEG_DONE, 0,
2302 0, &log, true, &bbr->rc_tv);
2303 }
2304 }
2305
2306 static void
bbr_log_enobuf_jmp(struct tcp_bbr * bbr,uint32_t len,uint32_t cts,int32_t line,uint32_t o_len,uint32_t segcnt,uint32_t segsiz)2307 bbr_log_enobuf_jmp(struct tcp_bbr *bbr, uint32_t len, uint32_t cts,
2308 int32_t line, uint32_t o_len, uint32_t segcnt, uint32_t segsiz)
2309 {
2310 if (tcp_bblogging_on(bbr->rc_tp)) {
2311 union tcp_log_stackspecific log;
2312
2313 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2314 log.u_bbr.flex1 = line;
2315 log.u_bbr.flex2 = o_len;
2316 log.u_bbr.flex3 = segcnt;
2317 log.u_bbr.flex4 = segsiz;
2318 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2319 &bbr->rc_inp->inp_socket->so_rcv,
2320 &bbr->rc_inp->inp_socket->so_snd,
2321 BBR_LOG_ENOBUF_JMP, ENOBUFS,
2322 len, &log, true, &bbr->rc_tv);
2323 }
2324 }
2325
2326 static void
bbr_log_to_processing(struct tcp_bbr * bbr,uint32_t cts,int32_t ret,int32_t timers,uint8_t hpts_calling)2327 bbr_log_to_processing(struct tcp_bbr *bbr, uint32_t cts, int32_t ret, int32_t timers, uint8_t hpts_calling)
2328 {
2329 if (tcp_bblogging_on(bbr->rc_tp)) {
2330 union tcp_log_stackspecific log;
2331
2332 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2333 log.u_bbr.flex1 = timers;
2334 log.u_bbr.flex2 = ret;
2335 log.u_bbr.flex3 = bbr->r_ctl.rc_timer_exp;
2336 log.u_bbr.flex4 = bbr->r_ctl.rc_hpts_flags;
2337 log.u_bbr.flex5 = cts;
2338 log.u_bbr.flex6 = bbr->r_ctl.rc_target_at_state;
2339 log.u_bbr.flex8 = hpts_calling;
2340 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2341 &bbr->rc_inp->inp_socket->so_rcv,
2342 &bbr->rc_inp->inp_socket->so_snd,
2343 BBR_LOG_TO_PROCESS, 0,
2344 0, &log, false, &bbr->rc_tv);
2345 }
2346 }
2347
2348 static void
bbr_log_to_event(struct tcp_bbr * bbr,uint32_t cts,int32_t to_num)2349 bbr_log_to_event(struct tcp_bbr *bbr, uint32_t cts, int32_t to_num)
2350 {
2351 if (tcp_bblogging_on(bbr->rc_tp)) {
2352 union tcp_log_stackspecific log;
2353 uint64_t ar;
2354
2355 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2356 log.u_bbr.flex1 = bbr->bbr_timer_src;
2357 log.u_bbr.flex2 = 0;
2358 log.u_bbr.flex3 = bbr->r_ctl.rc_hpts_flags;
2359 ar = (uintptr_t)(bbr->r_ctl.rc_resend);
2360 ar >>= 32;
2361 ar &= 0x00000000ffffffff;
2362 log.u_bbr.flex4 = (uint32_t)ar;
2363 ar = (uintptr_t)bbr->r_ctl.rc_resend;
2364 ar &= 0x00000000ffffffff;
2365 log.u_bbr.flex5 = (uint32_t)ar;
2366 log.u_bbr.flex6 = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
2367 log.u_bbr.flex8 = to_num;
2368 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2369 &bbr->rc_inp->inp_socket->so_rcv,
2370 &bbr->rc_inp->inp_socket->so_snd,
2371 BBR_LOG_RTO, 0,
2372 0, &log, false, &bbr->rc_tv);
2373 }
2374 }
2375
2376 static void
bbr_log_startup_event(struct tcp_bbr * bbr,uint32_t cts,uint32_t flex1,uint32_t flex2,uint32_t flex3,uint8_t reason)2377 bbr_log_startup_event(struct tcp_bbr *bbr, uint32_t cts, uint32_t flex1, uint32_t flex2, uint32_t flex3, uint8_t reason)
2378 {
2379 if (tcp_bblogging_on(bbr->rc_tp)) {
2380 union tcp_log_stackspecific log;
2381
2382 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2383 log.u_bbr.flex1 = flex1;
2384 log.u_bbr.flex2 = flex2;
2385 log.u_bbr.flex3 = flex3;
2386 log.u_bbr.flex4 = 0;
2387 log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
2388 log.u_bbr.flex6 = bbr->r_ctl.rc_lost_at_startup;
2389 log.u_bbr.flex8 = reason;
2390 log.u_bbr.cur_del_rate = bbr->r_ctl.rc_bbr_lastbtlbw;
2391 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2392 &bbr->rc_inp->inp_socket->so_rcv,
2393 &bbr->rc_inp->inp_socket->so_snd,
2394 BBR_LOG_REDUCE, 0,
2395 0, &log, false, &bbr->rc_tv);
2396 }
2397 }
2398
2399 static void
bbr_log_hpts_diag(struct tcp_bbr * bbr,uint32_t cts,struct hpts_diag * diag)2400 bbr_log_hpts_diag(struct tcp_bbr *bbr, uint32_t cts, struct hpts_diag *diag)
2401 {
2402 if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2403 union tcp_log_stackspecific log;
2404
2405 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2406 log.u_bbr.flex1 = diag->p_nxt_slot;
2407 log.u_bbr.flex2 = diag->p_cur_slot;
2408 log.u_bbr.flex3 = diag->slot_req;
2409 log.u_bbr.flex4 = diag->inp_hptsslot;
2410 log.u_bbr.flex5 = diag->slot_remaining;
2411 log.u_bbr.flex6 = diag->need_new_to;
2412 log.u_bbr.flex7 = diag->p_hpts_active;
2413 log.u_bbr.flex8 = diag->p_on_min_sleep;
2414 /* Hijack other fields as needed */
2415 log.u_bbr.epoch = diag->have_slept;
2416 log.u_bbr.lt_epoch = diag->yet_to_sleep;
2417 log.u_bbr.pkts_out = diag->co_ret;
2418 log.u_bbr.applimited = diag->hpts_sleep_time;
2419 log.u_bbr.delivered = diag->p_prev_slot;
2420 log.u_bbr.inflight = diag->p_runningslot;
2421 log.u_bbr.bw_inuse = diag->wheel_slot;
2422 log.u_bbr.rttProp = diag->wheel_cts;
2423 log.u_bbr.delRate = diag->maxslots;
2424 log.u_bbr.cur_del_rate = diag->p_curtick;
2425 log.u_bbr.cur_del_rate <<= 32;
2426 log.u_bbr.cur_del_rate |= diag->p_lasttick;
2427 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2428 &bbr->rc_inp->inp_socket->so_rcv,
2429 &bbr->rc_inp->inp_socket->so_snd,
2430 BBR_LOG_HPTSDIAG, 0,
2431 0, &log, false, &bbr->rc_tv);
2432 }
2433 }
2434
2435 static void
bbr_log_timer_var(struct tcp_bbr * bbr,int mode,uint32_t cts,uint32_t time_since_sent,uint32_t srtt,uint32_t thresh,uint32_t to)2436 bbr_log_timer_var(struct tcp_bbr *bbr, int mode, uint32_t cts, uint32_t time_since_sent, uint32_t srtt,
2437 uint32_t thresh, uint32_t to)
2438 {
2439 if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2440 union tcp_log_stackspecific log;
2441
2442 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2443 log.u_bbr.flex1 = bbr->rc_tp->t_rttvar;
2444 log.u_bbr.flex2 = time_since_sent;
2445 log.u_bbr.flex3 = srtt;
2446 log.u_bbr.flex4 = thresh;
2447 log.u_bbr.flex5 = to;
2448 log.u_bbr.flex6 = bbr->rc_tp->t_srtt;
2449 log.u_bbr.flex8 = mode;
2450 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2451 &bbr->rc_inp->inp_socket->so_rcv,
2452 &bbr->rc_inp->inp_socket->so_snd,
2453 BBR_LOG_TIMERPREP, 0,
2454 0, &log, false, &bbr->rc_tv);
2455 }
2456 }
2457
2458 static void
bbr_log_pacing_delay_calc(struct tcp_bbr * bbr,uint16_t gain,uint32_t len,uint32_t cts,uint32_t usecs,uint64_t bw,uint32_t override,int mod)2459 bbr_log_pacing_delay_calc(struct tcp_bbr *bbr, uint16_t gain, uint32_t len,
2460 uint32_t cts, uint32_t usecs, uint64_t bw, uint32_t override, int mod)
2461 {
2462 if (tcp_bblogging_on(bbr->rc_tp)) {
2463 union tcp_log_stackspecific log;
2464
2465 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2466 log.u_bbr.flex1 = usecs;
2467 log.u_bbr.flex2 = len;
2468 log.u_bbr.flex3 = (uint32_t)((bw >> 32) & 0x00000000ffffffff);
2469 log.u_bbr.flex4 = (uint32_t)(bw & 0x00000000ffffffff);
2470 if (override)
2471 log.u_bbr.flex5 = (1 << 2);
2472 else
2473 log.u_bbr.flex5 = 0;
2474 log.u_bbr.flex6 = override;
2475 log.u_bbr.flex7 = gain;
2476 log.u_bbr.flex8 = mod;
2477 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2478 &bbr->rc_inp->inp_socket->so_rcv,
2479 &bbr->rc_inp->inp_socket->so_snd,
2480 BBR_LOG_HPTSI_CALC, 0,
2481 len, &log, false, &bbr->rc_tv);
2482 }
2483 }
2484
2485 static void
bbr_log_to_start(struct tcp_bbr * bbr,uint32_t cts,uint32_t to,int32_t slot,uint8_t which)2486 bbr_log_to_start(struct tcp_bbr *bbr, uint32_t cts, uint32_t to, int32_t slot, uint8_t which)
2487 {
2488 if (tcp_bblogging_on(bbr->rc_tp)) {
2489 union tcp_log_stackspecific log;
2490
2491 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2492
2493 log.u_bbr.flex1 = bbr->bbr_timer_src;
2494 log.u_bbr.flex2 = to;
2495 log.u_bbr.flex3 = bbr->r_ctl.rc_hpts_flags;
2496 log.u_bbr.flex4 = slot;
2497 log.u_bbr.flex5 = bbr->rc_tp->t_hpts_slot;
2498 log.u_bbr.flex6 = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
2499 log.u_bbr.pkts_out = bbr->rc_tp->t_flags2;
2500 log.u_bbr.flex8 = which;
2501 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2502 &bbr->rc_inp->inp_socket->so_rcv,
2503 &bbr->rc_inp->inp_socket->so_snd,
2504 BBR_LOG_TIMERSTAR, 0,
2505 0, &log, false, &bbr->rc_tv);
2506 }
2507 }
2508
2509 static void
bbr_log_thresh_choice(struct tcp_bbr * bbr,uint32_t cts,uint32_t thresh,uint32_t lro,uint32_t srtt,struct bbr_sendmap * rsm,uint8_t frm)2510 bbr_log_thresh_choice(struct tcp_bbr *bbr, uint32_t cts, uint32_t thresh, uint32_t lro, uint32_t srtt, struct bbr_sendmap *rsm, uint8_t frm)
2511 {
2512 if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2513 union tcp_log_stackspecific log;
2514
2515 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2516 log.u_bbr.flex1 = thresh;
2517 log.u_bbr.flex2 = lro;
2518 log.u_bbr.flex3 = bbr->r_ctl.rc_reorder_ts;
2519 log.u_bbr.flex4 = rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)];
2520 log.u_bbr.flex5 = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
2521 log.u_bbr.flex6 = srtt;
2522 log.u_bbr.flex7 = bbr->r_ctl.rc_reorder_shift;
2523 log.u_bbr.flex8 = frm;
2524 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2525 &bbr->rc_inp->inp_socket->so_rcv,
2526 &bbr->rc_inp->inp_socket->so_snd,
2527 BBR_LOG_THRESH_CALC, 0,
2528 0, &log, false, &bbr->rc_tv);
2529 }
2530 }
2531
2532 static void
bbr_log_to_cancel(struct tcp_bbr * bbr,int32_t line,uint32_t cts,uint8_t hpts_removed)2533 bbr_log_to_cancel(struct tcp_bbr *bbr, int32_t line, uint32_t cts, uint8_t hpts_removed)
2534 {
2535 if (tcp_bblogging_on(bbr->rc_tp)) {
2536 union tcp_log_stackspecific log;
2537
2538 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2539 log.u_bbr.flex1 = line;
2540 log.u_bbr.flex2 = bbr->bbr_timer_src;
2541 log.u_bbr.flex3 = bbr->r_ctl.rc_hpts_flags;
2542 log.u_bbr.flex4 = bbr->rc_in_persist;
2543 log.u_bbr.flex5 = bbr->r_ctl.rc_target_at_state;
2544 log.u_bbr.flex6 = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
2545 log.u_bbr.flex8 = hpts_removed;
2546 log.u_bbr.pkts_out = bbr->rc_pacer_started;
2547 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2548 &bbr->rc_inp->inp_socket->so_rcv,
2549 &bbr->rc_inp->inp_socket->so_snd,
2550 BBR_LOG_TIMERCANC, 0,
2551 0, &log, false, &bbr->rc_tv);
2552 }
2553 }
2554
2555 static void
bbr_log_tstmp_validation(struct tcp_bbr * bbr,uint64_t peer_delta,uint64_t delta)2556 bbr_log_tstmp_validation(struct tcp_bbr *bbr, uint64_t peer_delta, uint64_t delta)
2557 {
2558 if (tcp_bblogging_on(bbr->rc_tp)) {
2559 union tcp_log_stackspecific log;
2560
2561 bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2562 log.u_bbr.flex1 = bbr->r_ctl.bbr_peer_tsratio;
2563 log.u_bbr.flex2 = (peer_delta >> 32);
2564 log.u_bbr.flex3 = (peer_delta & 0x00000000ffffffff);
2565 log.u_bbr.flex4 = (delta >> 32);
2566 log.u_bbr.flex5 = (delta & 0x00000000ffffffff);
2567 log.u_bbr.flex7 = bbr->rc_ts_clock_set;
2568 log.u_bbr.flex8 = bbr->rc_ts_cant_be_used;
2569 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2570 &bbr->rc_inp->inp_socket->so_rcv,
2571 &bbr->rc_inp->inp_socket->so_snd,
2572 BBR_LOG_TSTMP_VAL, 0,
2573 0, &log, false, &bbr->rc_tv);
2574 }
2575 }
2576
2577 static void
bbr_log_type_tsosize(struct tcp_bbr * bbr,uint32_t cts,uint32_t tsosz,uint32_t tls,uint32_t old_val,uint32_t maxseg,int hdwr)2578 bbr_log_type_tsosize(struct tcp_bbr *bbr, uint32_t cts, uint32_t tsosz, uint32_t tls, uint32_t old_val, uint32_t maxseg, int hdwr)
2579 {
2580 if (tcp_bblogging_on(bbr->rc_tp)) {
2581 union tcp_log_stackspecific log;
2582
2583 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2584 log.u_bbr.flex1 = tsosz;
2585 log.u_bbr.flex2 = tls;
2586 log.u_bbr.flex3 = tcp_min_hptsi_time;
2587 log.u_bbr.flex4 = bbr->r_ctl.bbr_hptsi_bytes_min;
2588 log.u_bbr.flex5 = old_val;
2589 log.u_bbr.flex6 = maxseg;
2590 log.u_bbr.flex7 = bbr->rc_no_pacing;
2591 log.u_bbr.flex7 <<= 1;
2592 log.u_bbr.flex7 |= bbr->rc_past_init_win;
2593 if (hdwr)
2594 log.u_bbr.flex8 = 0x80 | bbr->rc_use_google;
2595 else
2596 log.u_bbr.flex8 = bbr->rc_use_google;
2597 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2598 &bbr->rc_inp->inp_socket->so_rcv,
2599 &bbr->rc_inp->inp_socket->so_snd,
2600 BBR_LOG_BBRTSO, 0,
2601 0, &log, false, &bbr->rc_tv);
2602 }
2603 }
2604
2605 static void
bbr_log_type_rsmclear(struct tcp_bbr * bbr,uint32_t cts,struct bbr_sendmap * rsm,uint32_t flags,uint32_t line)2606 bbr_log_type_rsmclear(struct tcp_bbr *bbr, uint32_t cts, struct bbr_sendmap *rsm,
2607 uint32_t flags, uint32_t line)
2608 {
2609 if (tcp_bblogging_on(bbr->rc_tp)) {
2610 union tcp_log_stackspecific log;
2611
2612 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2613 log.u_bbr.flex1 = line;
2614 log.u_bbr.flex2 = rsm->r_start;
2615 log.u_bbr.flex3 = rsm->r_end;
2616 log.u_bbr.flex4 = rsm->r_delivered;
2617 log.u_bbr.flex5 = rsm->r_rtr_cnt;
2618 log.u_bbr.flex6 = rsm->r_dupack;
2619 log.u_bbr.flex7 = rsm->r_tim_lastsent[0];
2620 log.u_bbr.flex8 = rsm->r_flags;
2621 /* Hijack the pkts_out fids */
2622 log.u_bbr.applimited = flags;
2623 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2624 &bbr->rc_inp->inp_socket->so_rcv,
2625 &bbr->rc_inp->inp_socket->so_snd,
2626 BBR_RSM_CLEARED, 0,
2627 0, &log, false, &bbr->rc_tv);
2628 }
2629 }
2630
2631 static void
bbr_log_type_bbrupd(struct tcp_bbr * bbr,uint8_t flex8,uint32_t cts,uint32_t flex3,uint32_t flex2,uint32_t flex5,uint32_t flex6,uint32_t pkts_out,int flex7,uint32_t flex4,uint32_t flex1)2632 bbr_log_type_bbrupd(struct tcp_bbr *bbr, uint8_t flex8, uint32_t cts,
2633 uint32_t flex3, uint32_t flex2, uint32_t flex5,
2634 uint32_t flex6, uint32_t pkts_out, int flex7,
2635 uint32_t flex4, uint32_t flex1)
2636 {
2637
2638 if (tcp_bblogging_on(bbr->rc_tp)) {
2639 union tcp_log_stackspecific log;
2640
2641 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2642 log.u_bbr.flex1 = flex1;
2643 log.u_bbr.flex2 = flex2;
2644 log.u_bbr.flex3 = flex3;
2645 log.u_bbr.flex4 = flex4;
2646 log.u_bbr.flex5 = flex5;
2647 log.u_bbr.flex6 = flex6;
2648 log.u_bbr.flex7 = flex7;
2649 /* Hijack the pkts_out fids */
2650 log.u_bbr.pkts_out = pkts_out;
2651 log.u_bbr.flex8 = flex8;
2652 if (bbr->rc_ack_was_delayed)
2653 log.u_bbr.epoch = bbr->r_ctl.rc_ack_hdwr_delay;
2654 else
2655 log.u_bbr.epoch = 0;
2656 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2657 &bbr->rc_inp->inp_socket->so_rcv,
2658 &bbr->rc_inp->inp_socket->so_snd,
2659 BBR_LOG_BBRUPD, 0,
2660 flex2, &log, false, &bbr->rc_tv);
2661 }
2662 }
2663
2664 static void
bbr_log_type_ltbw(struct tcp_bbr * bbr,uint32_t cts,int32_t reason,uint32_t newbw,uint32_t obw,uint32_t diff,uint32_t tim)2665 bbr_log_type_ltbw(struct tcp_bbr *bbr, uint32_t cts, int32_t reason,
2666 uint32_t newbw, uint32_t obw, uint32_t diff,
2667 uint32_t tim)
2668 {
2669 if (/*bbr_verbose_logging && */tcp_bblogging_on(bbr->rc_tp)) {
2670 union tcp_log_stackspecific log;
2671
2672 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2673 log.u_bbr.flex1 = reason;
2674 log.u_bbr.flex2 = newbw;
2675 log.u_bbr.flex3 = obw;
2676 log.u_bbr.flex4 = diff;
2677 log.u_bbr.flex5 = bbr->r_ctl.rc_lt_lost;
2678 log.u_bbr.flex6 = bbr->r_ctl.rc_lt_del;
2679 log.u_bbr.flex7 = bbr->rc_lt_is_sampling;
2680 log.u_bbr.pkts_out = tim;
2681 log.u_bbr.bw_inuse = bbr->r_ctl.rc_lt_bw;
2682 if (bbr->rc_lt_use_bw == 0)
2683 log.u_bbr.epoch = bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_lt_epoch;
2684 else
2685 log.u_bbr.epoch = bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_lt_epoch_use;
2686 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2687 &bbr->rc_inp->inp_socket->so_rcv,
2688 &bbr->rc_inp->inp_socket->so_snd,
2689 BBR_LOG_BWSAMP, 0,
2690 0, &log, false, &bbr->rc_tv);
2691 }
2692 }
2693
2694 static inline void
bbr_log_progress_event(struct tcp_bbr * bbr,struct tcpcb * tp,uint32_t tick,int event,int line)2695 bbr_log_progress_event(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t tick, int event, int line)
2696 {
2697 if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2698 union tcp_log_stackspecific log;
2699
2700 bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2701 log.u_bbr.flex1 = line;
2702 log.u_bbr.flex2 = tick;
2703 log.u_bbr.flex3 = tp->t_maxunacktime;
2704 log.u_bbr.flex4 = tp->t_acktime;
2705 log.u_bbr.flex8 = event;
2706 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2707 &bbr->rc_inp->inp_socket->so_rcv,
2708 &bbr->rc_inp->inp_socket->so_snd,
2709 BBR_LOG_PROGRESS, 0,
2710 0, &log, false, &bbr->rc_tv);
2711 }
2712 }
2713
2714 static void
bbr_type_log_hdwr_pacing(struct tcp_bbr * bbr,const struct ifnet * ifp,uint64_t rate,uint64_t hw_rate,int line,uint32_t cts,int error)2715 bbr_type_log_hdwr_pacing(struct tcp_bbr *bbr, const struct ifnet *ifp,
2716 uint64_t rate, uint64_t hw_rate, int line, uint32_t cts,
2717 int error)
2718 {
2719 if (tcp_bblogging_on(bbr->rc_tp)) {
2720 union tcp_log_stackspecific log;
2721 uint64_t ifp64 = (uintptr_t)ifp;
2722
2723 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2724 log.u_bbr.flex1 = ((hw_rate >> 32) & 0x00000000ffffffff);
2725 log.u_bbr.flex2 = (hw_rate & 0x00000000ffffffff);
2726 log.u_bbr.flex3 = ((ifp64 >> 32) & 0x00000000ffffffff);
2727 log.u_bbr.flex4 = (ifp64 & 0x00000000ffffffff);
2728 log.u_bbr.bw_inuse = rate;
2729 log.u_bbr.flex5 = line;
2730 log.u_bbr.flex6 = error;
2731 log.u_bbr.flex8 = bbr->skip_gain;
2732 log.u_bbr.flex8 <<= 1;
2733 log.u_bbr.flex8 |= bbr->gain_is_limited;
2734 log.u_bbr.flex8 <<= 1;
2735 log.u_bbr.flex8 |= bbr->bbr_hdrw_pacing;
2736 log.u_bbr.pkts_out = bbr->rc_tp->t_maxseg;
2737 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2738 &bbr->rc_inp->inp_socket->so_rcv,
2739 &bbr->rc_inp->inp_socket->so_snd,
2740 BBR_LOG_HDWR_PACE, 0,
2741 0, &log, false, &bbr->rc_tv);
2742 }
2743 }
2744
2745 static void
bbr_log_type_bbrsnd(struct tcp_bbr * bbr,uint32_t len,uint32_t slot,uint32_t del_by,uint32_t cts,uint32_t line,uint32_t prev_delay)2746 bbr_log_type_bbrsnd(struct tcp_bbr *bbr, uint32_t len, uint32_t slot, uint32_t del_by, uint32_t cts, uint32_t line, uint32_t prev_delay)
2747 {
2748 if (tcp_bblogging_on(bbr->rc_tp)) {
2749 union tcp_log_stackspecific log;
2750
2751 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2752 log.u_bbr.flex1 = slot;
2753 log.u_bbr.flex2 = del_by;
2754 log.u_bbr.flex3 = prev_delay;
2755 log.u_bbr.flex4 = line;
2756 log.u_bbr.flex5 = bbr->r_ctl.rc_last_delay_val;
2757 log.u_bbr.flex6 = bbr->r_ctl.rc_hptsi_agg_delay;
2758 log.u_bbr.flex7 = (0x0000ffff & bbr->r_ctl.rc_hpts_flags);
2759 log.u_bbr.flex8 = bbr->rc_in_persist;
2760 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2761 &bbr->rc_inp->inp_socket->so_rcv,
2762 &bbr->rc_inp->inp_socket->so_snd,
2763 BBR_LOG_BBRSND, 0,
2764 len, &log, false, &bbr->rc_tv);
2765 }
2766 }
2767
2768 static void
bbr_log_type_bbrrttprop(struct tcp_bbr * bbr,uint32_t t,uint32_t end,uint32_t tsconv,uint32_t cts,int32_t match,uint32_t seq,uint8_t flags)2769 bbr_log_type_bbrrttprop(struct tcp_bbr *bbr, uint32_t t, uint32_t end, uint32_t tsconv, uint32_t cts, int32_t match, uint32_t seq, uint8_t flags)
2770 {
2771 if (tcp_bblogging_on(bbr->rc_tp)) {
2772 union tcp_log_stackspecific log;
2773
2774 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2775 log.u_bbr.flex1 = bbr->r_ctl.rc_delivered;
2776 log.u_bbr.flex2 = 0;
2777 log.u_bbr.flex3 = bbr->r_ctl.rc_lowest_rtt;
2778 log.u_bbr.flex4 = end;
2779 log.u_bbr.flex5 = seq;
2780 log.u_bbr.flex6 = t;
2781 log.u_bbr.flex7 = match;
2782 log.u_bbr.flex8 = flags;
2783 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2784 &bbr->rc_inp->inp_socket->so_rcv,
2785 &bbr->rc_inp->inp_socket->so_snd,
2786 BBR_LOG_BBRRTT, 0,
2787 0, &log, false, &bbr->rc_tv);
2788 }
2789 }
2790
2791 static void
bbr_log_exit_gain(struct tcp_bbr * bbr,uint32_t cts,int32_t entry_method)2792 bbr_log_exit_gain(struct tcp_bbr *bbr, uint32_t cts, int32_t entry_method)
2793 {
2794 if (tcp_bblogging_on(bbr->rc_tp)) {
2795 union tcp_log_stackspecific log;
2796
2797 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
2798 log.u_bbr.flex1 = bbr->r_ctl.rc_target_at_state;
2799 log.u_bbr.flex2 = (bbr->rc_tp->t_maxseg - bbr->rc_last_options);
2800 log.u_bbr.flex3 = bbr->r_ctl.gain_epoch;
2801 log.u_bbr.flex4 = bbr->r_ctl.rc_pace_max_segs;
2802 log.u_bbr.flex5 = bbr->r_ctl.rc_pace_min_segs;
2803 log.u_bbr.flex6 = bbr->r_ctl.rc_bbr_state_atflight;
2804 log.u_bbr.flex7 = 0;
2805 log.u_bbr.flex8 = entry_method;
2806 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2807 &bbr->rc_inp->inp_socket->so_rcv,
2808 &bbr->rc_inp->inp_socket->so_snd,
2809 BBR_LOG_EXIT_GAIN, 0,
2810 0, &log, false, &bbr->rc_tv);
2811 }
2812 }
2813
2814 static void
bbr_log_settings_change(struct tcp_bbr * bbr,int settings_desired)2815 bbr_log_settings_change(struct tcp_bbr *bbr, int settings_desired)
2816 {
2817 if (bbr_verbose_logging && tcp_bblogging_on(bbr->rc_tp)) {
2818 union tcp_log_stackspecific log;
2819
2820 bbr_fill_in_logging_data(bbr, &log.u_bbr, bbr->r_ctl.rc_rcvtime);
2821 /* R-HU */
2822 log.u_bbr.flex1 = 0;
2823 log.u_bbr.flex2 = 0;
2824 log.u_bbr.flex3 = 0;
2825 log.u_bbr.flex4 = 0;
2826 log.u_bbr.flex7 = 0;
2827 log.u_bbr.flex8 = settings_desired;
2828
2829 TCP_LOG_EVENTP(bbr->rc_tp, NULL,
2830 &bbr->rc_inp->inp_socket->so_rcv,
2831 &bbr->rc_inp->inp_socket->so_snd,
2832 BBR_LOG_SETTINGS_CHG, 0,
2833 0, &log, false, &bbr->rc_tv);
2834 }
2835 }
2836
2837 /*
2838 * Returns the bw from the our filter.
2839 */
2840 static inline uint64_t
bbr_get_full_bw(struct tcp_bbr * bbr)2841 bbr_get_full_bw(struct tcp_bbr *bbr)
2842 {
2843 uint64_t bw;
2844
2845 bw = get_filter_value(&bbr->r_ctl.rc_delrate);
2846
2847 return (bw);
2848 }
2849
2850 static inline void
bbr_set_pktepoch(struct tcp_bbr * bbr,uint32_t cts,int32_t line)2851 bbr_set_pktepoch(struct tcp_bbr *bbr, uint32_t cts, int32_t line)
2852 {
2853 uint64_t calclr;
2854 uint32_t lost, del;
2855
2856 if (bbr->r_ctl.rc_lost > bbr->r_ctl.rc_lost_at_pktepoch)
2857 lost = bbr->r_ctl.rc_lost - bbr->r_ctl.rc_lost_at_pktepoch;
2858 else
2859 lost = 0;
2860 del = bbr->r_ctl.rc_delivered - bbr->r_ctl.rc_pkt_epoch_del;
2861 if (lost == 0) {
2862 calclr = 0;
2863 } else if (del) {
2864 calclr = lost;
2865 calclr *= (uint64_t)1000;
2866 calclr /= (uint64_t)del;
2867 } else {
2868 /* Nothing delivered? 100.0% loss */
2869 calclr = 1000;
2870 }
2871 bbr->r_ctl.rc_pkt_epoch_loss_rate = (uint32_t)calclr;
2872 if (IN_RECOVERY(bbr->rc_tp->t_flags))
2873 bbr->r_ctl.recovery_lr += (uint32_t)calclr;
2874 bbr->r_ctl.rc_pkt_epoch++;
2875 if (bbr->rc_no_pacing &&
2876 (bbr->r_ctl.rc_pkt_epoch >= bbr->no_pacing_until)) {
2877 bbr->rc_no_pacing = 0;
2878 tcp_bbr_tso_size_check(bbr, cts);
2879 }
2880 bbr->r_ctl.rc_pkt_epoch_rtt = bbr_calc_time(cts, bbr->r_ctl.rc_pkt_epoch_time);
2881 bbr->r_ctl.rc_pkt_epoch_time = cts;
2882 /* What was our loss rate */
2883 bbr_log_pkt_epoch(bbr, cts, line, lost, del);
2884 bbr->r_ctl.rc_pkt_epoch_del = bbr->r_ctl.rc_delivered;
2885 bbr->r_ctl.rc_lost_at_pktepoch = bbr->r_ctl.rc_lost;
2886 }
2887
2888 static inline void
bbr_set_epoch(struct tcp_bbr * bbr,uint32_t cts,int32_t line)2889 bbr_set_epoch(struct tcp_bbr *bbr, uint32_t cts, int32_t line)
2890 {
2891 uint32_t epoch_time;
2892
2893 /* Tick the RTT clock */
2894 bbr->r_ctl.rc_rtt_epoch++;
2895 epoch_time = cts - bbr->r_ctl.rc_rcv_epoch_start;
2896 bbr_log_time_epoch(bbr, cts, line, epoch_time);
2897 bbr->r_ctl.rc_rcv_epoch_start = cts;
2898 }
2899
2900 static inline void
bbr_isit_a_pkt_epoch(struct tcp_bbr * bbr,uint32_t cts,struct bbr_sendmap * rsm,int32_t line,int32_t cum_acked)2901 bbr_isit_a_pkt_epoch(struct tcp_bbr *bbr, uint32_t cts, struct bbr_sendmap *rsm, int32_t line, int32_t cum_acked)
2902 {
2903 if (SEQ_GEQ(rsm->r_delivered, bbr->r_ctl.rc_pkt_epoch_del)) {
2904 bbr->rc_is_pkt_epoch_now = 1;
2905 }
2906 }
2907
2908 /*
2909 * Returns the bw from either the b/w filter
2910 * or from the lt_bw (if the connection is being
2911 * policed).
2912 */
2913 static inline uint64_t
__bbr_get_bw(struct tcp_bbr * bbr)2914 __bbr_get_bw(struct tcp_bbr *bbr)
2915 {
2916 uint64_t bw, min_bw;
2917 uint64_t rtt;
2918 int gm_measure_cnt = 1;
2919
2920 /*
2921 * For startup we make, like google, a
2922 * minimum b/w. This is generated from the
2923 * IW and the rttProp. We do fall back to srtt
2924 * if for some reason (initial handshake) we don't
2925 * have a rttProp. We, in the worst case, fall back
2926 * to the configured min_bw (rc_initial_hptsi_bw).
2927 */
2928 if (bbr->rc_bbr_state == BBR_STATE_STARTUP) {
2929 /* Attempt first to use rttProp */
2930 rtt = (uint64_t)get_filter_value_small(&bbr->r_ctl.rc_rttprop);
2931 if (rtt && (rtt < 0xffffffff)) {
2932 measure:
2933 min_bw = (uint64_t)(bbr_initial_cwnd(bbr, bbr->rc_tp)) *
2934 ((uint64_t)1000000);
2935 min_bw /= rtt;
2936 if (min_bw < bbr->r_ctl.rc_initial_hptsi_bw) {
2937 min_bw = bbr->r_ctl.rc_initial_hptsi_bw;
2938 }
2939
2940 } else if (bbr->rc_tp->t_srtt != 0) {
2941 /* No rttProp, use srtt? */
2942 rtt = bbr_get_rtt(bbr, BBR_SRTT);
2943 goto measure;
2944 } else {
2945 min_bw = bbr->r_ctl.rc_initial_hptsi_bw;
2946 }
2947 } else
2948 min_bw = 0;
2949
2950 if ((bbr->rc_past_init_win == 0) &&
2951 (bbr->r_ctl.rc_delivered > bbr_initial_cwnd(bbr, bbr->rc_tp)))
2952 bbr->rc_past_init_win = 1;
2953 if ((bbr->rc_use_google) && (bbr->r_ctl.r_measurement_count >= 1))
2954 gm_measure_cnt = 0;
2955 if (gm_measure_cnt &&
2956 ((bbr->r_ctl.r_measurement_count < bbr_min_measurements_req) ||
2957 (bbr->rc_past_init_win == 0))) {
2958 /* For google we use our guess rate until we get 1 measurement */
2959
2960 use_initial_window:
2961 rtt = (uint64_t)get_filter_value_small(&bbr->r_ctl.rc_rttprop);
2962 if (rtt && (rtt < 0xffffffff)) {
2963 /*
2964 * We have an RTT measurement. Use that in
2965 * combination with our initial window to calculate
2966 * a b/w.
2967 */
2968 bw = (uint64_t)(bbr_initial_cwnd(bbr, bbr->rc_tp)) *
2969 ((uint64_t)1000000);
2970 bw /= rtt;
2971 if (bw < bbr->r_ctl.rc_initial_hptsi_bw) {
2972 bw = bbr->r_ctl.rc_initial_hptsi_bw;
2973 }
2974 } else {
2975 /* Drop back to the 40 and punt to a default */
2976 bw = bbr->r_ctl.rc_initial_hptsi_bw;
2977 }
2978 if (bw < 1)
2979 /* Probably should panic */
2980 bw = 1;
2981 if (bw > min_bw)
2982 return (bw);
2983 else
2984 return (min_bw);
2985 }
2986 if (bbr->rc_lt_use_bw)
2987 bw = bbr->r_ctl.rc_lt_bw;
2988 else if (bbr->r_recovery_bw && (bbr->rc_use_google == 0))
2989 bw = bbr->r_ctl.red_bw;
2990 else
2991 bw = get_filter_value(&bbr->r_ctl.rc_delrate);
2992 if (bw == 0) {
2993 /* We should not be at 0, go to the initial window then */
2994 goto use_initial_window;
2995 }
2996 if (bw < 1)
2997 /* Probably should panic */
2998 bw = 1;
2999 if (bw < min_bw)
3000 bw = min_bw;
3001 return (bw);
3002 }
3003
3004 static inline uint64_t
bbr_get_bw(struct tcp_bbr * bbr)3005 bbr_get_bw(struct tcp_bbr *bbr)
3006 {
3007 uint64_t bw;
3008
3009 bw = __bbr_get_bw(bbr);
3010 return (bw);
3011 }
3012
3013 static inline void
bbr_reset_lt_bw_interval(struct tcp_bbr * bbr,uint32_t cts)3014 bbr_reset_lt_bw_interval(struct tcp_bbr *bbr, uint32_t cts)
3015 {
3016 bbr->r_ctl.rc_lt_epoch = bbr->r_ctl.rc_pkt_epoch;
3017 bbr->r_ctl.rc_lt_time = bbr->r_ctl.rc_del_time;
3018 bbr->r_ctl.rc_lt_del = bbr->r_ctl.rc_delivered;
3019 bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
3020 }
3021
3022 static inline void
bbr_reset_lt_bw_sampling(struct tcp_bbr * bbr,uint32_t cts)3023 bbr_reset_lt_bw_sampling(struct tcp_bbr *bbr, uint32_t cts)
3024 {
3025 bbr->rc_lt_is_sampling = 0;
3026 bbr->rc_lt_use_bw = 0;
3027 bbr->r_ctl.rc_lt_bw = 0;
3028 bbr_reset_lt_bw_interval(bbr, cts);
3029 }
3030
3031 static inline void
bbr_lt_bw_samp_done(struct tcp_bbr * bbr,uint64_t bw,uint32_t cts,uint32_t timin)3032 bbr_lt_bw_samp_done(struct tcp_bbr *bbr, uint64_t bw, uint32_t cts, uint32_t timin)
3033 {
3034 uint64_t diff;
3035
3036 /* Do we have a previous sample? */
3037 if (bbr->r_ctl.rc_lt_bw) {
3038 /* Get the diff in bytes per second */
3039 if (bbr->r_ctl.rc_lt_bw > bw)
3040 diff = bbr->r_ctl.rc_lt_bw - bw;
3041 else
3042 diff = bw - bbr->r_ctl.rc_lt_bw;
3043 if ((diff <= bbr_lt_bw_diff) ||
3044 (diff <= (bbr->r_ctl.rc_lt_bw / bbr_lt_bw_ratio))) {
3045 /* Consider us policed */
3046 uint32_t saved_bw;
3047
3048 saved_bw = (uint32_t)bbr->r_ctl.rc_lt_bw;
3049 bbr->r_ctl.rc_lt_bw = (bw + bbr->r_ctl.rc_lt_bw) / 2; /* average of two */
3050 bbr->rc_lt_use_bw = 1;
3051 bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
3052 /*
3053 * Use pkt based epoch for measuring length of
3054 * policer up
3055 */
3056 bbr->r_ctl.rc_lt_epoch_use = bbr->r_ctl.rc_pkt_epoch;
3057 /*
3058 * reason 4 is we need to start consider being
3059 * policed
3060 */
3061 bbr_log_type_ltbw(bbr, cts, 4, (uint32_t)bw, saved_bw, (uint32_t)diff, timin);
3062 return;
3063 }
3064 }
3065 bbr->r_ctl.rc_lt_bw = bw;
3066 bbr_reset_lt_bw_interval(bbr, cts);
3067 bbr_log_type_ltbw(bbr, cts, 5, 0, (uint32_t)bw, 0, timin);
3068 }
3069
3070 static void
bbr_randomize_extra_state_time(struct tcp_bbr * bbr)3071 bbr_randomize_extra_state_time(struct tcp_bbr *bbr)
3072 {
3073 uint32_t ran, deduct;
3074
3075 ran = arc4random_uniform(bbr_rand_ot);
3076 if (ran) {
3077 deduct = bbr->r_ctl.rc_level_state_extra / ran;
3078 bbr->r_ctl.rc_level_state_extra -= deduct;
3079 }
3080 }
3081 /*
3082 * Return randomly the starting state
3083 * to use in probebw.
3084 */
3085 static uint8_t
bbr_pick_probebw_substate(struct tcp_bbr * bbr,uint32_t cts)3086 bbr_pick_probebw_substate(struct tcp_bbr *bbr, uint32_t cts)
3087 {
3088 uint32_t ran;
3089 uint8_t ret_val;
3090
3091 /* Initialize the offset to 0 */
3092 bbr->r_ctl.rc_exta_time_gd = 0;
3093 bbr->rc_hit_state_1 = 0;
3094 bbr->r_ctl.rc_level_state_extra = 0;
3095 ran = arc4random_uniform((BBR_SUBSTATE_COUNT-1));
3096 /*
3097 * The math works funny here :) the return value is used to set the
3098 * substate and then the state change is called which increments by
3099 * one. So if we return 1 (DRAIN) we will increment to 2 (LEVEL1) when
3100 * we fully enter the state. Note that the (8 - 1 - ran) assures that
3101 * we return 1 - 7, so we dont return 0 and end up starting in
3102 * state 1 (DRAIN).
3103 */
3104 ret_val = BBR_SUBSTATE_COUNT - 1 - ran;
3105 /* Set an epoch */
3106 if ((cts - bbr->r_ctl.rc_rcv_epoch_start) >= bbr_get_rtt(bbr, BBR_RTT_PROP))
3107 bbr_set_epoch(bbr, cts, __LINE__);
3108
3109 bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
3110 return (ret_val);
3111 }
3112
3113 static void
bbr_lt_bw_sampling(struct tcp_bbr * bbr,uint32_t cts,int32_t loss_detected)3114 bbr_lt_bw_sampling(struct tcp_bbr *bbr, uint32_t cts, int32_t loss_detected)
3115 {
3116 uint32_t diff, d_time;
3117 uint64_t del_time, bw, lost, delivered;
3118
3119 if (bbr->r_use_policer == 0)
3120 return;
3121 if (bbr->rc_lt_use_bw) {
3122 /* We are using lt bw do we stop yet? */
3123 diff = bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_lt_epoch_use;
3124 if (diff > bbr_lt_bw_max_rtts) {
3125 /* Reset it all */
3126 reset_all:
3127 bbr_reset_lt_bw_sampling(bbr, cts);
3128 if (bbr->rc_filled_pipe) {
3129 bbr_set_epoch(bbr, cts, __LINE__);
3130 bbr->rc_bbr_substate = bbr_pick_probebw_substate(bbr, cts);
3131 bbr_substate_change(bbr, cts, __LINE__, 0);
3132 bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
3133 bbr_log_type_statechange(bbr, cts, __LINE__);
3134 } else {
3135 /*
3136 * This should not happen really
3137 * unless we remove the startup/drain
3138 * restrictions above.
3139 */
3140 bbr->rc_bbr_state = BBR_STATE_STARTUP;
3141 bbr_set_epoch(bbr, cts, __LINE__);
3142 bbr->r_ctl.rc_bbr_state_time = cts;
3143 bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
3144 bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.rc_startup_pg;
3145 bbr->r_ctl.rc_bbr_cwnd_gain = bbr->r_ctl.rc_startup_pg;
3146 bbr_set_state_target(bbr, __LINE__);
3147 bbr_log_type_statechange(bbr, cts, __LINE__);
3148 }
3149 /* reason 0 is to stop using lt-bw */
3150 bbr_log_type_ltbw(bbr, cts, 0, 0, 0, 0, 0);
3151 return;
3152 }
3153 if (bbr_lt_intvl_fp == 0) {
3154 /* Not doing false-positive detection */
3155 return;
3156 }
3157 /* False positive detection */
3158 if (diff == bbr_lt_intvl_fp) {
3159 /* At bbr_lt_intvl_fp we record the lost */
3160 bbr->r_ctl.rc_lt_del = bbr->r_ctl.rc_delivered;
3161 bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
3162 } else if (diff > (bbr_lt_intvl_min_rtts + bbr_lt_intvl_fp)) {
3163 /* Now is our loss rate still high? */
3164 lost = bbr->r_ctl.rc_lost - bbr->r_ctl.rc_lt_lost;
3165 delivered = bbr->r_ctl.rc_delivered - bbr->r_ctl.rc_lt_del;
3166 if ((delivered == 0) ||
3167 (((lost * 1000)/delivered) < bbr_lt_fd_thresh)) {
3168 /* No still below our threshold */
3169 bbr_log_type_ltbw(bbr, cts, 7, lost, delivered, 0, 0);
3170 } else {
3171 /* Yikes its still high, it must be a false positive */
3172 bbr_log_type_ltbw(bbr, cts, 8, lost, delivered, 0, 0);
3173 goto reset_all;
3174 }
3175 }
3176 return;
3177 }
3178 /*
3179 * Wait for the first loss before sampling, to let the policer
3180 * exhaust its tokens and estimate the steady-state rate allowed by
3181 * the policer. Starting samples earlier includes bursts that
3182 * over-estimate the bw.
3183 */
3184 if (bbr->rc_lt_is_sampling == 0) {
3185 /* reason 1 is to begin doing the sampling */
3186 if (loss_detected == 0)
3187 return;
3188 bbr_reset_lt_bw_interval(bbr, cts);
3189 bbr->rc_lt_is_sampling = 1;
3190 bbr_log_type_ltbw(bbr, cts, 1, 0, 0, 0, 0);
3191 return;
3192 }
3193 /* Now how long were we delivering long term last> */
3194 if (TSTMP_GEQ(bbr->r_ctl.rc_del_time, bbr->r_ctl.rc_lt_time))
3195 d_time = bbr->r_ctl.rc_del_time - bbr->r_ctl.rc_lt_time;
3196 else
3197 d_time = 0;
3198
3199 /* To avoid underestimates, reset sampling if we run out of data. */
3200 if (bbr->r_ctl.r_app_limited_until) {
3201 /* Can not measure in app-limited state */
3202 bbr_reset_lt_bw_sampling(bbr, cts);
3203 /* reason 2 is to reset sampling due to app limits */
3204 bbr_log_type_ltbw(bbr, cts, 2, 0, 0, 0, d_time);
3205 return;
3206 }
3207 diff = bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_lt_epoch;
3208 if (diff < bbr_lt_intvl_min_rtts) {
3209 /*
3210 * need more samples (we don't
3211 * start on a round like linux so
3212 * we need 1 more).
3213 */
3214 /* 6 is not_enough time or no-loss */
3215 bbr_log_type_ltbw(bbr, cts, 6, 0, 0, 0, d_time);
3216 return;
3217 }
3218 if (diff > (4 * bbr_lt_intvl_min_rtts)) {
3219 /*
3220 * For now if we wait too long, reset all sampling. We need
3221 * to do some research here, its possible that we should
3222 * base this on how much loss as occurred.. something like
3223 * if its under 10% (or some thresh) reset all otherwise
3224 * don't. Thats for phase II I guess.
3225 */
3226 bbr_reset_lt_bw_sampling(bbr, cts);
3227 /* reason 3 is to reset sampling due too long of sampling */
3228 bbr_log_type_ltbw(bbr, cts, 3, 0, 0, 0, d_time);
3229 return;
3230 }
3231 /*
3232 * End sampling interval when a packet is lost, so we estimate the
3233 * policer tokens were exhausted. Stopping the sampling before the
3234 * tokens are exhausted under-estimates the policed rate.
3235 */
3236 if (loss_detected == 0) {
3237 /* 6 is not_enough time or no-loss */
3238 bbr_log_type_ltbw(bbr, cts, 6, 0, 0, 0, d_time);
3239 return;
3240 }
3241 /* Calculate packets lost and delivered in sampling interval. */
3242 lost = bbr->r_ctl.rc_lost - bbr->r_ctl.rc_lt_lost;
3243 delivered = bbr->r_ctl.rc_delivered - bbr->r_ctl.rc_lt_del;
3244 if ((delivered == 0) ||
3245 (((lost * 1000)/delivered) < bbr_lt_loss_thresh)) {
3246 bbr_log_type_ltbw(bbr, cts, 6, lost, delivered, 0, d_time);
3247 return;
3248 }
3249 if (d_time < 1000) {
3250 /* Not enough time. wait */
3251 /* 6 is not_enough time or no-loss */
3252 bbr_log_type_ltbw(bbr, cts, 6, 0, 0, 0, d_time);
3253 return;
3254 }
3255 if (d_time >= (0xffffffff / USECS_IN_MSEC)) {
3256 /* Too long */
3257 bbr_reset_lt_bw_sampling(bbr, cts);
3258 /* reason 3 is to reset sampling due too long of sampling */
3259 bbr_log_type_ltbw(bbr, cts, 3, 0, 0, 0, d_time);
3260 return;
3261 }
3262 del_time = d_time;
3263 bw = delivered;
3264 bw *= (uint64_t)USECS_IN_SECOND;
3265 bw /= del_time;
3266 bbr_lt_bw_samp_done(bbr, bw, cts, d_time);
3267 }
3268
3269 /*
3270 * Allocate a sendmap from our zone.
3271 */
3272 static struct bbr_sendmap *
bbr_alloc(struct tcp_bbr * bbr)3273 bbr_alloc(struct tcp_bbr *bbr)
3274 {
3275 struct bbr_sendmap *rsm;
3276
3277 BBR_STAT_INC(bbr_to_alloc);
3278 rsm = uma_zalloc(bbr_zone, (M_NOWAIT | M_ZERO));
3279 if (rsm) {
3280 bbr->r_ctl.rc_num_maps_alloced++;
3281 return (rsm);
3282 }
3283 if (bbr->r_ctl.rc_free_cnt) {
3284 BBR_STAT_INC(bbr_to_alloc_emerg);
3285 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_free);
3286 TAILQ_REMOVE(&bbr->r_ctl.rc_free, rsm, r_next);
3287 bbr->r_ctl.rc_free_cnt--;
3288 return (rsm);
3289 }
3290 BBR_STAT_INC(bbr_to_alloc_failed);
3291 return (NULL);
3292 }
3293
3294 static struct bbr_sendmap *
bbr_alloc_full_limit(struct tcp_bbr * bbr)3295 bbr_alloc_full_limit(struct tcp_bbr *bbr)
3296 {
3297 if ((V_tcp_map_entries_limit > 0) &&
3298 (bbr->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
3299 BBR_STAT_INC(bbr_alloc_limited);
3300 if (!bbr->alloc_limit_reported) {
3301 bbr->alloc_limit_reported = 1;
3302 BBR_STAT_INC(bbr_alloc_limited_conns);
3303 }
3304 return (NULL);
3305 }
3306 return (bbr_alloc(bbr));
3307 }
3308
3309 /* wrapper to allocate a sendmap entry, subject to a specific limit */
3310 static struct bbr_sendmap *
bbr_alloc_limit(struct tcp_bbr * bbr,uint8_t limit_type)3311 bbr_alloc_limit(struct tcp_bbr *bbr, uint8_t limit_type)
3312 {
3313 struct bbr_sendmap *rsm;
3314
3315 if (limit_type) {
3316 /* currently there is only one limit type */
3317 if (V_tcp_map_split_limit > 0 &&
3318 bbr->r_ctl.rc_num_split_allocs >= V_tcp_map_split_limit) {
3319 BBR_STAT_INC(bbr_split_limited);
3320 if (!bbr->alloc_limit_reported) {
3321 bbr->alloc_limit_reported = 1;
3322 BBR_STAT_INC(bbr_alloc_limited_conns);
3323 }
3324 return (NULL);
3325 }
3326 }
3327
3328 /* allocate and mark in the limit type, if set */
3329 rsm = bbr_alloc(bbr);
3330 if (rsm != NULL && limit_type) {
3331 rsm->r_limit_type = limit_type;
3332 bbr->r_ctl.rc_num_split_allocs++;
3333 }
3334 return (rsm);
3335 }
3336
3337 static void
bbr_free(struct tcp_bbr * bbr,struct bbr_sendmap * rsm)3338 bbr_free(struct tcp_bbr *bbr, struct bbr_sendmap *rsm)
3339 {
3340 if (rsm->r_limit_type) {
3341 /* currently there is only one limit type */
3342 bbr->r_ctl.rc_num_split_allocs--;
3343 }
3344 if (rsm->r_is_smallmap)
3345 bbr->r_ctl.rc_num_small_maps_alloced--;
3346 if (bbr->r_ctl.rc_tlp_send == rsm)
3347 bbr->r_ctl.rc_tlp_send = NULL;
3348 if (bbr->r_ctl.rc_resend == rsm) {
3349 bbr->r_ctl.rc_resend = NULL;
3350 }
3351 if (bbr->r_ctl.rc_next == rsm)
3352 bbr->r_ctl.rc_next = NULL;
3353 if (bbr->r_ctl.rc_sacklast == rsm)
3354 bbr->r_ctl.rc_sacklast = NULL;
3355 if (bbr->r_ctl.rc_free_cnt < bbr_min_req_free) {
3356 memset(rsm, 0, sizeof(struct bbr_sendmap));
3357 TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_free, rsm, r_next);
3358 rsm->r_limit_type = 0;
3359 bbr->r_ctl.rc_free_cnt++;
3360 return;
3361 }
3362 bbr->r_ctl.rc_num_maps_alloced--;
3363 uma_zfree(bbr_zone, rsm);
3364 }
3365
3366 /*
3367 * Returns the BDP.
3368 */
3369 static uint64_t
bbr_get_bw_delay_prod(uint64_t rtt,uint64_t bw)3370 bbr_get_bw_delay_prod(uint64_t rtt, uint64_t bw) {
3371 /*
3372 * Calculate the bytes in flight needed given the bw (in bytes per
3373 * second) and the specifyed rtt in useconds. We need to put out the
3374 * returned value per RTT to match that rate. Gain will normally
3375 * raise it up from there.
3376 *
3377 * This should not overflow as long as the bandwidth is below 1
3378 * TByte per second (bw < 10**12 = 2**40) and the rtt is smaller
3379 * than 1000 seconds (rtt < 10**3 * 10**6 = 10**9 = 2**30).
3380 */
3381 uint64_t usec_per_sec;
3382
3383 usec_per_sec = USECS_IN_SECOND;
3384 return ((rtt * bw) / usec_per_sec);
3385 }
3386
3387 /*
3388 * Return the initial cwnd.
3389 */
3390 static uint32_t
bbr_initial_cwnd(struct tcp_bbr * bbr,struct tcpcb * tp)3391 bbr_initial_cwnd(struct tcp_bbr *bbr, struct tcpcb *tp)
3392 {
3393 uint32_t i_cwnd;
3394
3395 if (bbr->rc_init_win) {
3396 i_cwnd = bbr->rc_init_win * tp->t_maxseg;
3397 } else if (V_tcp_initcwnd_segments)
3398 i_cwnd = min((V_tcp_initcwnd_segments * tp->t_maxseg),
3399 max(2 * tp->t_maxseg, 14600));
3400 else if (V_tcp_do_rfc3390)
3401 i_cwnd = min(4 * tp->t_maxseg,
3402 max(2 * tp->t_maxseg, 4380));
3403 else {
3404 /* Per RFC5681 Section 3.1 */
3405 if (tp->t_maxseg > 2190)
3406 i_cwnd = 2 * tp->t_maxseg;
3407 else if (tp->t_maxseg > 1095)
3408 i_cwnd = 3 * tp->t_maxseg;
3409 else
3410 i_cwnd = 4 * tp->t_maxseg;
3411 }
3412 return (i_cwnd);
3413 }
3414
3415 /*
3416 * Given a specified gain, return the target
3417 * cwnd based on that gain.
3418 */
3419 static uint32_t
bbr_get_raw_target_cwnd(struct tcp_bbr * bbr,uint32_t gain,uint64_t bw)3420 bbr_get_raw_target_cwnd(struct tcp_bbr *bbr, uint32_t gain, uint64_t bw)
3421 {
3422 uint64_t bdp, rtt;
3423 uint32_t cwnd;
3424
3425 if ((get_filter_value_small(&bbr->r_ctl.rc_rttprop) == 0xffffffff) ||
3426 (bbr_get_full_bw(bbr) == 0)) {
3427 /* No measurements yet */
3428 return (bbr_initial_cwnd(bbr, bbr->rc_tp));
3429 }
3430 /*
3431 * Get bytes per RTT needed (rttProp is normally in
3432 * bbr_cwndtarget_rtt_touse)
3433 */
3434 rtt = bbr_get_rtt(bbr, bbr_cwndtarget_rtt_touse);
3435 /* Get the bdp from the two values */
3436 bdp = bbr_get_bw_delay_prod(rtt, bw);
3437 /* Now apply the gain */
3438 cwnd = (uint32_t)(((bdp * ((uint64_t)gain)) + (uint64_t)(BBR_UNIT - 1)) / ((uint64_t)BBR_UNIT));
3439
3440 return (cwnd);
3441 }
3442
3443 static uint32_t
bbr_get_target_cwnd(struct tcp_bbr * bbr,uint64_t bw,uint32_t gain)3444 bbr_get_target_cwnd(struct tcp_bbr *bbr, uint64_t bw, uint32_t gain)
3445 {
3446 uint32_t cwnd, mss;
3447
3448 mss = min((bbr->rc_tp->t_maxseg - bbr->rc_last_options), bbr->r_ctl.rc_pace_max_segs);
3449 /* Get the base cwnd with gain rounded to a mss */
3450 cwnd = roundup(bbr_get_raw_target_cwnd(bbr, bw, gain), mss);
3451 /*
3452 * Add in N (2 default since we do not have a
3453 * fq layer to trap packets in) quanta's per the I-D
3454 * section 4.2.3.2 quanta adjust.
3455 */
3456 cwnd += (bbr_quanta * bbr->r_ctl.rc_pace_max_segs);
3457 if (bbr->rc_use_google) {
3458 if((bbr->rc_bbr_state == BBR_STATE_PROBE_BW) &&
3459 (bbr_state_val(bbr) == BBR_SUB_GAIN)) {
3460 /*
3461 * The linux implementation adds
3462 * an extra 2 x mss in gain cycle which
3463 * is documented no-where except in the code.
3464 * so we add more for Neal undocumented feature
3465 */
3466 cwnd += 2 * mss;
3467 }
3468 if ((cwnd / mss) & 0x1) {
3469 /* Round up for odd num mss */
3470 cwnd += mss;
3471 }
3472 }
3473 /* Are we below the min cwnd? */
3474 if (cwnd < get_min_cwnd(bbr))
3475 return (get_min_cwnd(bbr));
3476 return (cwnd);
3477 }
3478
3479 static uint16_t
bbr_gain_adjust(struct tcp_bbr * bbr,uint16_t gain)3480 bbr_gain_adjust(struct tcp_bbr *bbr, uint16_t gain)
3481 {
3482 if (gain < 1)
3483 gain = 1;
3484 return (gain);
3485 }
3486
3487 static uint32_t
bbr_get_header_oh(struct tcp_bbr * bbr)3488 bbr_get_header_oh(struct tcp_bbr *bbr)
3489 {
3490 int seg_oh;
3491
3492 seg_oh = 0;
3493 if (bbr->r_ctl.rc_inc_tcp_oh) {
3494 /* Do we include TCP overhead? */
3495 seg_oh = (bbr->rc_last_options + sizeof(struct tcphdr));
3496 }
3497 if (bbr->r_ctl.rc_inc_ip_oh) {
3498 /* Do we include IP overhead? */
3499 #ifdef INET6
3500 if (bbr->r_is_v6) {
3501 seg_oh += sizeof(struct ip6_hdr);
3502 } else
3503 #endif
3504 {
3505
3506 #ifdef INET
3507 seg_oh += sizeof(struct ip);
3508 #endif
3509 }
3510 }
3511 if (bbr->r_ctl.rc_inc_enet_oh) {
3512 /* Do we include the ethernet overhead? */
3513 seg_oh += sizeof(struct ether_header);
3514 }
3515 return(seg_oh);
3516 }
3517
3518 static uint32_t
bbr_get_pacing_length(struct tcp_bbr * bbr,uint16_t gain,uint32_t useconds_time,uint64_t bw)3519 bbr_get_pacing_length(struct tcp_bbr *bbr, uint16_t gain, uint32_t useconds_time, uint64_t bw)
3520 {
3521 uint64_t divor, res, tim;
3522
3523 if (useconds_time == 0)
3524 return (0);
3525 gain = bbr_gain_adjust(bbr, gain);
3526 divor = (uint64_t)USECS_IN_SECOND * (uint64_t)BBR_UNIT;
3527 tim = useconds_time;
3528 res = (tim * bw * gain) / divor;
3529 if (res == 0)
3530 res = 1;
3531 return ((uint32_t)res);
3532 }
3533
3534 /*
3535 * Given a gain and a length return the delay in useconds that
3536 * should be used to evenly space out packets
3537 * on the connection (based on the gain factor).
3538 */
3539 static uint32_t
bbr_get_pacing_delay(struct tcp_bbr * bbr,uint16_t gain,int32_t len,uint32_t cts,int nolog)3540 bbr_get_pacing_delay(struct tcp_bbr *bbr, uint16_t gain, int32_t len, uint32_t cts, int nolog)
3541 {
3542 uint64_t bw, lentim, res;
3543 uint32_t usecs, srtt, over = 0;
3544 uint32_t seg_oh, num_segs, maxseg;
3545
3546 if (len == 0)
3547 return (0);
3548
3549 maxseg = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
3550 num_segs = (len + maxseg - 1) / maxseg;
3551 if (bbr->rc_use_google == 0) {
3552 seg_oh = bbr_get_header_oh(bbr);
3553 len += (num_segs * seg_oh);
3554 }
3555 gain = bbr_gain_adjust(bbr, gain);
3556 bw = bbr_get_bw(bbr);
3557 if (bbr->rc_use_google) {
3558 uint64_t cbw;
3559
3560 /*
3561 * Reduce the b/w by the google discount
3562 * factor 10 = 1%.
3563 */
3564 cbw = bw * (uint64_t)(1000 - bbr->r_ctl.bbr_google_discount);
3565 cbw /= (uint64_t)1000;
3566 /* We don't apply a discount if it results in 0 */
3567 if (cbw > 0)
3568 bw = cbw;
3569 }
3570 lentim = ((uint64_t)len *
3571 (uint64_t)USECS_IN_SECOND *
3572 (uint64_t)BBR_UNIT);
3573 res = lentim / ((uint64_t)gain * bw);
3574 if (res == 0)
3575 res = 1;
3576 usecs = (uint32_t)res;
3577 srtt = bbr_get_rtt(bbr, BBR_SRTT);
3578 if (bbr_hptsi_max_mul && bbr_hptsi_max_div &&
3579 (bbr->rc_use_google == 0) &&
3580 (usecs > ((srtt * bbr_hptsi_max_mul) / bbr_hptsi_max_div))) {
3581 /*
3582 * We cannot let the delay be more than 1/2 the srtt time.
3583 * Otherwise we cannot pace out or send properly.
3584 */
3585 over = usecs = (srtt * bbr_hptsi_max_mul) / bbr_hptsi_max_div;
3586 BBR_STAT_INC(bbr_hpts_min_time);
3587 }
3588 if (!nolog)
3589 bbr_log_pacing_delay_calc(bbr, gain, len, cts, usecs, bw, over, 1);
3590 return (usecs);
3591 }
3592
3593 static void
bbr_ack_received(struct tcpcb * tp,struct tcp_bbr * bbr,struct tcphdr * th,uint32_t bytes_this_ack,uint32_t sack_changed,uint32_t prev_acked,int32_t line,uint32_t losses)3594 bbr_ack_received(struct tcpcb *tp, struct tcp_bbr *bbr, struct tcphdr *th, uint32_t bytes_this_ack,
3595 uint32_t sack_changed, uint32_t prev_acked, int32_t line, uint32_t losses)
3596 {
3597 uint64_t bw;
3598 uint32_t cwnd, target_cwnd, saved_bytes, maxseg;
3599 int32_t meth;
3600
3601 INP_WLOCK_ASSERT(tptoinpcb(tp));
3602
3603 #ifdef STATS
3604 if ((tp->t_flags & TF_GPUTINPROG) &&
3605 SEQ_GEQ(th->th_ack, tp->gput_ack)) {
3606 /*
3607 * Strech acks and compressed acks will cause this to
3608 * oscillate but we are doing it the same way as the main
3609 * stack so it will be compariable (though possibly not
3610 * ideal).
3611 */
3612 int32_t cgput;
3613 int64_t gput, time_stamp;
3614
3615 gput = (int64_t) (th->th_ack - tp->gput_seq) * 8;
3616 time_stamp = max(1, ((bbr->r_ctl.rc_rcvtime - tp->gput_ts) / 1000));
3617 cgput = gput / time_stamp;
3618 stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_GPUT,
3619 cgput);
3620 if (tp->t_stats_gput_prev > 0)
3621 stats_voi_update_abs_s32(tp->t_stats,
3622 VOI_TCP_GPUT_ND,
3623 ((gput - tp->t_stats_gput_prev) * 100) /
3624 tp->t_stats_gput_prev);
3625 tp->t_flags &= ~TF_GPUTINPROG;
3626 tp->t_stats_gput_prev = cgput;
3627 }
3628 #endif
3629 if ((bbr->rc_bbr_state == BBR_STATE_PROBE_RTT) &&
3630 ((bbr->r_ctl.bbr_rttprobe_gain_val == 0) || bbr->rc_use_google)) {
3631 /* We don't change anything in probe-rtt */
3632 return;
3633 }
3634 maxseg = tp->t_maxseg - bbr->rc_last_options;
3635 saved_bytes = bytes_this_ack;
3636 bytes_this_ack += sack_changed;
3637 if (bytes_this_ack > prev_acked) {
3638 bytes_this_ack -= prev_acked;
3639 /*
3640 * A byte ack'd gives us a full mss
3641 * to be like linux i.e. they count packets.
3642 */
3643 if ((bytes_this_ack < maxseg) && bbr->rc_use_google)
3644 bytes_this_ack = maxseg;
3645 } else {
3646 /* Unlikely */
3647 bytes_this_ack = 0;
3648 }
3649 cwnd = tp->snd_cwnd;
3650 bw = get_filter_value(&bbr->r_ctl.rc_delrate);
3651 if (bw)
3652 target_cwnd = bbr_get_target_cwnd(bbr,
3653 bw,
3654 (uint32_t)bbr->r_ctl.rc_bbr_cwnd_gain);
3655 else
3656 target_cwnd = bbr_initial_cwnd(bbr, bbr->rc_tp);
3657 if (IN_RECOVERY(tp->t_flags) &&
3658 (bbr->bbr_prev_in_rec == 0)) {
3659 /*
3660 * We are entering recovery and
3661 * thus packet conservation.
3662 */
3663 bbr->pkt_conservation = 1;
3664 bbr->r_ctl.rc_recovery_start = bbr->r_ctl.rc_rcvtime;
3665 cwnd = ctf_flight_size(tp,
3666 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) +
3667 bytes_this_ack;
3668 }
3669 if (IN_RECOVERY(tp->t_flags)) {
3670 uint32_t flight;
3671
3672 bbr->bbr_prev_in_rec = 1;
3673 if (cwnd > losses) {
3674 cwnd -= losses;
3675 if (cwnd < maxseg)
3676 cwnd = maxseg;
3677 } else
3678 cwnd = maxseg;
3679 flight = ctf_flight_size(tp,
3680 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
3681 bbr_log_type_cwndupd(bbr, flight, 0,
3682 losses, 10, 0, 0, line);
3683 if (bbr->pkt_conservation) {
3684 uint32_t time_in;
3685
3686 if (TSTMP_GEQ(bbr->r_ctl.rc_rcvtime, bbr->r_ctl.rc_recovery_start))
3687 time_in = bbr->r_ctl.rc_rcvtime - bbr->r_ctl.rc_recovery_start;
3688 else
3689 time_in = 0;
3690
3691 if (time_in >= bbr_get_rtt(bbr, BBR_RTT_PROP)) {
3692 /* Clear packet conservation after an rttProp */
3693 bbr->pkt_conservation = 0;
3694 } else {
3695 if ((flight + bytes_this_ack) > cwnd)
3696 cwnd = flight + bytes_this_ack;
3697 if (cwnd < get_min_cwnd(bbr))
3698 cwnd = get_min_cwnd(bbr);
3699 tp->snd_cwnd = cwnd;
3700 bbr_log_type_cwndupd(bbr, saved_bytes, sack_changed,
3701 prev_acked, 1, target_cwnd, th->th_ack, line);
3702 return;
3703 }
3704 }
3705 } else
3706 bbr->bbr_prev_in_rec = 0;
3707 if ((bbr->rc_use_google == 0) && bbr->r_ctl.restrict_growth) {
3708 bbr->r_ctl.restrict_growth--;
3709 if (bytes_this_ack > maxseg)
3710 bytes_this_ack = maxseg;
3711 }
3712 if (bbr->rc_filled_pipe) {
3713 /*
3714 * Here we have exited startup and filled the pipe. We will
3715 * thus allow the cwnd to shrink to the target. We hit here
3716 * mostly.
3717 */
3718 uint32_t s_cwnd;
3719
3720 meth = 2;
3721 s_cwnd = min((cwnd + bytes_this_ack), target_cwnd);
3722 if (s_cwnd > cwnd)
3723 cwnd = s_cwnd;
3724 else if (bbr_cwnd_may_shrink || bbr->rc_use_google || bbr->rc_no_pacing)
3725 cwnd = s_cwnd;
3726 } else {
3727 /*
3728 * Here we are still in startup, we increase cwnd by what
3729 * has been acked.
3730 */
3731 if ((cwnd < target_cwnd) ||
3732 (bbr->rc_past_init_win == 0)) {
3733 meth = 3;
3734 cwnd += bytes_this_ack;
3735 } else {
3736 /*
3737 * Method 4 means we are at target so no gain in
3738 * startup and past the initial window.
3739 */
3740 meth = 4;
3741 }
3742 }
3743 tp->snd_cwnd = max(cwnd, get_min_cwnd(bbr));
3744 bbr_log_type_cwndupd(bbr, saved_bytes, sack_changed, prev_acked, meth, target_cwnd, th->th_ack, line);
3745 }
3746
3747 static void
tcp_bbr_partialack(struct tcpcb * tp)3748 tcp_bbr_partialack(struct tcpcb *tp)
3749 {
3750 struct tcp_bbr *bbr;
3751
3752 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
3753 INP_WLOCK_ASSERT(tptoinpcb(tp));
3754 if (ctf_flight_size(tp,
3755 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) <=
3756 tp->snd_cwnd) {
3757 bbr->r_wanted_output = 1;
3758 }
3759 }
3760
3761 static void
bbr_post_recovery(struct tcpcb * tp)3762 bbr_post_recovery(struct tcpcb *tp)
3763 {
3764 struct tcp_bbr *bbr;
3765 uint32_t flight;
3766
3767 INP_WLOCK_ASSERT(tptoinpcb(tp));
3768 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
3769 /*
3770 * Here we just exit recovery.
3771 */
3772 EXIT_RECOVERY(tp->t_flags);
3773 /* Lock in our b/w reduction for the specified number of pkt-epochs */
3774 bbr->r_recovery_bw = 0;
3775 tp->snd_recover = tp->snd_una;
3776 tcp_bbr_tso_size_check(bbr, bbr->r_ctl.rc_rcvtime);
3777 bbr->pkt_conservation = 0;
3778 if (bbr->rc_use_google == 0) {
3779 /*
3780 * For non-google mode lets
3781 * go ahead and make sure we clear
3782 * the recovery state so if we
3783 * bounce back in to recovery we
3784 * will do PC.
3785 */
3786 bbr->bbr_prev_in_rec = 0;
3787 }
3788 bbr_log_type_exit_rec(bbr);
3789 if (bbr->rc_bbr_state != BBR_STATE_PROBE_RTT) {
3790 tp->snd_cwnd = max(tp->snd_cwnd, bbr->r_ctl.rc_cwnd_on_ent);
3791 bbr_log_type_cwndupd(bbr, 0, 0, 0, 15, 0, 0, __LINE__);
3792 } else {
3793 /* For probe-rtt case lets fix up its saved_cwnd */
3794 if (bbr->r_ctl.rc_saved_cwnd < bbr->r_ctl.rc_cwnd_on_ent) {
3795 bbr->r_ctl.rc_saved_cwnd = bbr->r_ctl.rc_cwnd_on_ent;
3796 bbr_log_type_cwndupd(bbr, 0, 0, 0, 16, 0, 0, __LINE__);
3797 }
3798 }
3799 flight = ctf_flight_size(tp,
3800 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
3801 if ((bbr->rc_use_google == 0) &&
3802 bbr_do_red) {
3803 uint64_t val, lr2use;
3804 uint32_t maxseg, newcwnd, acks_inflight, ratio, cwnd;
3805 uint32_t *cwnd_p;
3806
3807 if (bbr_get_rtt(bbr, BBR_SRTT)) {
3808 val = ((uint64_t)bbr_get_rtt(bbr, BBR_RTT_PROP) * (uint64_t)1000);
3809 val /= bbr_get_rtt(bbr, BBR_SRTT);
3810 ratio = (uint32_t)val;
3811 } else
3812 ratio = 1000;
3813
3814 bbr_log_type_cwndupd(bbr, bbr_red_mul, bbr_red_div,
3815 bbr->r_ctl.recovery_lr, 21,
3816 ratio,
3817 bbr->r_ctl.rc_red_cwnd_pe,
3818 __LINE__);
3819 if ((ratio < bbr_do_red) || (bbr_do_red == 0))
3820 goto done;
3821 if (((bbr->rc_bbr_state == BBR_STATE_PROBE_RTT) &&
3822 bbr_prtt_slam_cwnd) ||
3823 (bbr_sub_drain_slam_cwnd &&
3824 (bbr->rc_bbr_state == BBR_STATE_PROBE_BW) &&
3825 bbr->rc_hit_state_1 &&
3826 (bbr_state_val(bbr) == BBR_SUB_DRAIN)) ||
3827 ((bbr->rc_bbr_state == BBR_STATE_DRAIN) &&
3828 bbr_slam_cwnd_in_main_drain)) {
3829 /*
3830 * Here we must poke at the saved cwnd
3831 * as well as the cwnd.
3832 */
3833 cwnd = bbr->r_ctl.rc_saved_cwnd;
3834 cwnd_p = &bbr->r_ctl.rc_saved_cwnd;
3835 } else {
3836 cwnd = tp->snd_cwnd;
3837 cwnd_p = &tp->snd_cwnd;
3838 }
3839 maxseg = tp->t_maxseg - bbr->rc_last_options;
3840 /* Add the overall lr with the recovery lr */
3841 if (bbr->r_ctl.rc_lost == 0)
3842 lr2use = 0;
3843 else if (bbr->r_ctl.rc_delivered == 0)
3844 lr2use = 1000;
3845 else {
3846 lr2use = bbr->r_ctl.rc_lost * 1000;
3847 lr2use /= bbr->r_ctl.rc_delivered;
3848 }
3849 lr2use += bbr->r_ctl.recovery_lr;
3850 acks_inflight = (flight / (maxseg * 2));
3851 if (bbr_red_scale) {
3852 lr2use *= bbr_get_rtt(bbr, BBR_SRTT);
3853 lr2use /= bbr_red_scale;
3854 if ((bbr_red_growth_restrict) &&
3855 ((bbr_get_rtt(bbr, BBR_SRTT)/bbr_red_scale) > 1))
3856 bbr->r_ctl.restrict_growth += acks_inflight;
3857 }
3858 if (lr2use) {
3859 val = (uint64_t)cwnd * lr2use;
3860 val /= 1000;
3861 if (cwnd > val)
3862 newcwnd = roundup((cwnd - val), maxseg);
3863 else
3864 newcwnd = maxseg;
3865 } else {
3866 val = (uint64_t)cwnd * (uint64_t)bbr_red_mul;
3867 val /= (uint64_t)bbr_red_div;
3868 newcwnd = roundup((uint32_t)val, maxseg);
3869 }
3870 /* with standard delayed acks how many acks can I expect? */
3871 if (bbr_drop_limit == 0) {
3872 /*
3873 * Anticpate how much we will
3874 * raise the cwnd based on the acks.
3875 */
3876 if ((newcwnd + (acks_inflight * maxseg)) < get_min_cwnd(bbr)) {
3877 /* We do enforce the min (with the acks) */
3878 newcwnd = (get_min_cwnd(bbr) - acks_inflight);
3879 }
3880 } else {
3881 /*
3882 * A strict drop limit of N is inplace
3883 */
3884 if (newcwnd < (bbr_drop_limit * maxseg)) {
3885 newcwnd = bbr_drop_limit * maxseg;
3886 }
3887 }
3888 /* For the next N acks do we restrict the growth */
3889 *cwnd_p = newcwnd;
3890 if (tp->snd_cwnd > newcwnd)
3891 tp->snd_cwnd = newcwnd;
3892 bbr_log_type_cwndupd(bbr, bbr_red_mul, bbr_red_div, val, 22,
3893 (uint32_t)lr2use,
3894 bbr_get_rtt(bbr, BBR_SRTT), __LINE__);
3895 bbr->r_ctl.rc_red_cwnd_pe = bbr->r_ctl.rc_pkt_epoch;
3896 }
3897 done:
3898 bbr->r_ctl.recovery_lr = 0;
3899 if (flight <= tp->snd_cwnd) {
3900 bbr->r_wanted_output = 1;
3901 }
3902 tcp_bbr_tso_size_check(bbr, bbr->r_ctl.rc_rcvtime);
3903 }
3904
3905 static void
bbr_setup_red_bw(struct tcp_bbr * bbr,uint32_t cts)3906 bbr_setup_red_bw(struct tcp_bbr *bbr, uint32_t cts)
3907 {
3908 bbr->r_ctl.red_bw = get_filter_value(&bbr->r_ctl.rc_delrate);
3909 /* Limit the drop in b/w to 1/2 our current filter. */
3910 if (bbr->r_ctl.red_bw > bbr->r_ctl.rc_bbr_cur_del_rate)
3911 bbr->r_ctl.red_bw = bbr->r_ctl.rc_bbr_cur_del_rate;
3912 if (bbr->r_ctl.red_bw < (get_filter_value(&bbr->r_ctl.rc_delrate) / 2))
3913 bbr->r_ctl.red_bw = get_filter_value(&bbr->r_ctl.rc_delrate) / 2;
3914 tcp_bbr_tso_size_check(bbr, cts);
3915 }
3916
3917 static void
bbr_cong_signal(struct tcpcb * tp,struct tcphdr * th,uint32_t type,struct bbr_sendmap * rsm)3918 bbr_cong_signal(struct tcpcb *tp, struct tcphdr *th, uint32_t type, struct bbr_sendmap *rsm)
3919 {
3920 struct tcp_bbr *bbr;
3921
3922 INP_WLOCK_ASSERT(tptoinpcb(tp));
3923 #ifdef STATS
3924 stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_CSIG, type);
3925 #endif
3926 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
3927 switch (type) {
3928 case CC_NDUPACK:
3929 if (!IN_RECOVERY(tp->t_flags)) {
3930 tp->snd_recover = tp->snd_max;
3931 /* Start a new epoch */
3932 bbr_set_pktepoch(bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
3933 if (bbr->rc_lt_is_sampling || bbr->rc_lt_use_bw) {
3934 /*
3935 * Move forward the lt epoch
3936 * so it won't count the truncated
3937 * epoch.
3938 */
3939 bbr->r_ctl.rc_lt_epoch++;
3940 }
3941 if (bbr->rc_bbr_state == BBR_STATE_STARTUP) {
3942 /*
3943 * Just like the policer detection code
3944 * if we are in startup we must push
3945 * forward the last startup epoch
3946 * to hide the truncated PE.
3947 */
3948 bbr->r_ctl.rc_bbr_last_startup_epoch++;
3949 }
3950 bbr->r_ctl.rc_cwnd_on_ent = tp->snd_cwnd;
3951 ENTER_RECOVERY(tp->t_flags);
3952 bbr->rc_tlp_rtx_out = 0;
3953 bbr->r_ctl.recovery_lr = bbr->r_ctl.rc_pkt_epoch_loss_rate;
3954 tcp_bbr_tso_size_check(bbr, bbr->r_ctl.rc_rcvtime);
3955 if (tcp_in_hpts(bbr->rc_tp) &&
3956 ((bbr->r_ctl.rc_hpts_flags & PACE_TMR_RACK) == 0)) {
3957 /*
3958 * When we enter recovery, we need to restart
3959 * any timers. This may mean we gain an agg
3960 * early, which will be made up for at the last
3961 * rxt out.
3962 */
3963 bbr->rc_timer_first = 1;
3964 bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
3965 }
3966 /*
3967 * Calculate a new cwnd based on to the current
3968 * delivery rate with no gain. We get the bdp
3969 * without gaining it up like we normally would and
3970 * we use the last cur_del_rate.
3971 */
3972 if ((bbr->rc_use_google == 0) &&
3973 (bbr->r_ctl.bbr_rttprobe_gain_val ||
3974 (bbr->rc_bbr_state != BBR_STATE_PROBE_RTT))) {
3975 tp->snd_cwnd = ctf_flight_size(tp,
3976 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) +
3977 (tp->t_maxseg - bbr->rc_last_options);
3978 if (tp->snd_cwnd < get_min_cwnd(bbr)) {
3979 /* We always gate to min cwnd */
3980 tp->snd_cwnd = get_min_cwnd(bbr);
3981 }
3982 bbr_log_type_cwndupd(bbr, 0, 0, 0, 14, 0, 0, __LINE__);
3983 }
3984 bbr_log_type_enter_rec(bbr, rsm->r_start);
3985 }
3986 break;
3987 case CC_RTO_ERR:
3988 KMOD_TCPSTAT_INC(tcps_sndrexmitbad);
3989 /* RTO was unnecessary, so reset everything. */
3990 bbr_reset_lt_bw_sampling(bbr, bbr->r_ctl.rc_rcvtime);
3991 if (bbr->rc_bbr_state != BBR_STATE_PROBE_RTT) {
3992 tp->snd_cwnd = tp->snd_cwnd_prev;
3993 tp->snd_ssthresh = tp->snd_ssthresh_prev;
3994 tp->snd_recover = tp->snd_recover_prev;
3995 tp->snd_cwnd = max(tp->snd_cwnd, bbr->r_ctl.rc_cwnd_on_ent);
3996 bbr_log_type_cwndupd(bbr, 0, 0, 0, 13, 0, 0, __LINE__);
3997 }
3998 tp->t_badrxtwin = 0;
3999 break;
4000 }
4001 }
4002
4003 /*
4004 * Indicate whether this ack should be delayed. We can delay the ack if
4005 * following conditions are met:
4006 * - There is no delayed ack timer in progress.
4007 * - Our last ack wasn't a 0-sized window. We never want to delay
4008 * the ack that opens up a 0-sized window.
4009 * - LRO wasn't used for this segment. We make sure by checking that the
4010 * segment size is not larger than the MSS.
4011 * - Delayed acks are enabled or this is a half-synchronized T/TCP
4012 * connection.
4013 * - The data being acked is less than a full segment (a stretch ack
4014 * of more than a segment we should ack.
4015 * - nsegs is 1 (if its more than that we received more than 1 ack).
4016 */
4017 #define DELAY_ACK(tp, bbr, nsegs) \
4018 (((tp->t_flags & TF_RXWIN0SENT) == 0) && \
4019 ((tp->t_flags & TF_DELACK) == 0) && \
4020 ((bbr->bbr_segs_rcvd + nsegs) < tp->t_delayed_ack) && \
4021 (tp->t_delayed_ack || (tp->t_flags & TF_NEEDSYN)))
4022
4023 /*
4024 * Return the lowest RSM in the map of
4025 * packets still in flight that is not acked.
4026 * This should normally find on the first one
4027 * since we remove packets from the send
4028 * map after they are marked ACKED.
4029 */
4030 static struct bbr_sendmap *
bbr_find_lowest_rsm(struct tcp_bbr * bbr)4031 bbr_find_lowest_rsm(struct tcp_bbr *bbr)
4032 {
4033 struct bbr_sendmap *rsm;
4034
4035 /*
4036 * Walk the time-order transmitted list looking for an rsm that is
4037 * not acked. This will be the one that was sent the longest time
4038 * ago that is still outstanding.
4039 */
4040 TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_tmap, r_tnext) {
4041 if (rsm->r_flags & BBR_ACKED) {
4042 continue;
4043 }
4044 goto finish;
4045 }
4046 finish:
4047 return (rsm);
4048 }
4049
4050 static struct bbr_sendmap *
bbr_find_high_nonack(struct tcp_bbr * bbr,struct bbr_sendmap * rsm)4051 bbr_find_high_nonack(struct tcp_bbr *bbr, struct bbr_sendmap *rsm)
4052 {
4053 struct bbr_sendmap *prsm;
4054
4055 /*
4056 * Walk the sequence order list backward until we hit and arrive at
4057 * the highest seq not acked. In theory when this is called it
4058 * should be the last segment (which it was not).
4059 */
4060 prsm = rsm;
4061 TAILQ_FOREACH_REVERSE_FROM(prsm, &bbr->r_ctl.rc_map, bbr_head, r_next) {
4062 if (prsm->r_flags & (BBR_ACKED | BBR_HAS_FIN)) {
4063 continue;
4064 }
4065 return (prsm);
4066 }
4067 return (NULL);
4068 }
4069
4070 /*
4071 * Returns to the caller the number of microseconds that
4072 * the packet can be outstanding before we think we
4073 * should have had an ack returned.
4074 */
4075 static uint32_t
bbr_calc_thresh_rack(struct tcp_bbr * bbr,uint32_t srtt,uint32_t cts,struct bbr_sendmap * rsm)4076 bbr_calc_thresh_rack(struct tcp_bbr *bbr, uint32_t srtt, uint32_t cts, struct bbr_sendmap *rsm)
4077 {
4078 /*
4079 * lro is the flag we use to determine if we have seen reordering.
4080 * If it gets set we have seen reordering. The reorder logic either
4081 * works in one of two ways:
4082 *
4083 * If reorder-fade is configured, then we track the last time we saw
4084 * re-ordering occur. If we reach the point where enough time as
4085 * passed we no longer consider reordering has occuring.
4086 *
4087 * Or if reorder-face is 0, then once we see reordering we consider
4088 * the connection to alway be subject to reordering and just set lro
4089 * to 1.
4090 *
4091 * In the end if lro is non-zero we add the extra time for
4092 * reordering in.
4093 */
4094 int32_t lro;
4095 uint32_t thresh, t_rxtcur;
4096
4097 if (srtt == 0)
4098 srtt = 1;
4099 if (bbr->r_ctl.rc_reorder_ts) {
4100 if (bbr->r_ctl.rc_reorder_fade) {
4101 if (SEQ_GEQ(cts, bbr->r_ctl.rc_reorder_ts)) {
4102 lro = cts - bbr->r_ctl.rc_reorder_ts;
4103 if (lro == 0) {
4104 /*
4105 * No time as passed since the last
4106 * reorder, mark it as reordering.
4107 */
4108 lro = 1;
4109 }
4110 } else {
4111 /* Negative time? */
4112 lro = 0;
4113 }
4114 if (lro > bbr->r_ctl.rc_reorder_fade) {
4115 /* Turn off reordering seen too */
4116 bbr->r_ctl.rc_reorder_ts = 0;
4117 lro = 0;
4118 }
4119 } else {
4120 /* Reodering does not fade */
4121 lro = 1;
4122 }
4123 } else {
4124 lro = 0;
4125 }
4126 thresh = srtt + bbr->r_ctl.rc_pkt_delay;
4127 if (lro) {
4128 /* It must be set, if not you get 1/4 rtt */
4129 if (bbr->r_ctl.rc_reorder_shift)
4130 thresh += (srtt >> bbr->r_ctl.rc_reorder_shift);
4131 else
4132 thresh += (srtt >> 2);
4133 } else {
4134 thresh += 1000;
4135 }
4136 /* We don't let the rack timeout be above a RTO */
4137 if ((bbr->rc_tp)->t_srtt == 0)
4138 t_rxtcur = BBR_INITIAL_RTO;
4139 else
4140 t_rxtcur = TICKS_2_USEC(bbr->rc_tp->t_rxtcur);
4141 if (thresh > t_rxtcur) {
4142 thresh = t_rxtcur;
4143 }
4144 /* And we don't want it above the RTO max either */
4145 if (thresh > (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND)) {
4146 thresh = (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND);
4147 }
4148 bbr_log_thresh_choice(bbr, cts, thresh, lro, srtt, rsm, BBR_TO_FRM_RACK);
4149 return (thresh);
4150 }
4151
4152 /*
4153 * Return to the caller the amount of time in mico-seconds
4154 * that should be used for the TLP timer from the last
4155 * send time of this packet.
4156 */
4157 static uint32_t
bbr_calc_thresh_tlp(struct tcpcb * tp,struct tcp_bbr * bbr,struct bbr_sendmap * rsm,uint32_t srtt,uint32_t cts)4158 bbr_calc_thresh_tlp(struct tcpcb *tp, struct tcp_bbr *bbr,
4159 struct bbr_sendmap *rsm, uint32_t srtt,
4160 uint32_t cts)
4161 {
4162 uint32_t thresh, len, maxseg, t_rxtcur;
4163 struct bbr_sendmap *prsm;
4164
4165 if (srtt == 0)
4166 srtt = 1;
4167 if (bbr->rc_tlp_threshold)
4168 thresh = srtt + (srtt / bbr->rc_tlp_threshold);
4169 else
4170 thresh = (srtt * 2);
4171 maxseg = tp->t_maxseg - bbr->rc_last_options;
4172 /* Get the previous sent packet, if any */
4173 len = rsm->r_end - rsm->r_start;
4174
4175 /* 2.1 behavior */
4176 prsm = TAILQ_PREV(rsm, bbr_head, r_tnext);
4177 if (prsm && (len <= maxseg)) {
4178 /*
4179 * Two packets outstanding, thresh should be (2*srtt) +
4180 * possible inter-packet delay (if any).
4181 */
4182 uint32_t inter_gap = 0;
4183 int idx, nidx;
4184
4185 idx = rsm->r_rtr_cnt - 1;
4186 nidx = prsm->r_rtr_cnt - 1;
4187 if (TSTMP_GEQ(rsm->r_tim_lastsent[nidx], prsm->r_tim_lastsent[idx])) {
4188 /* Yes it was sent later (or at the same time) */
4189 inter_gap = rsm->r_tim_lastsent[idx] - prsm->r_tim_lastsent[nidx];
4190 }
4191 thresh += inter_gap;
4192 } else if (len <= maxseg) {
4193 /*
4194 * Possibly compensate for delayed-ack.
4195 */
4196 uint32_t alt_thresh;
4197
4198 alt_thresh = srtt + (srtt / 2) + bbr_delayed_ack_time;
4199 if (alt_thresh > thresh)
4200 thresh = alt_thresh;
4201 }
4202 /* Not above the current RTO */
4203 if (tp->t_srtt == 0)
4204 t_rxtcur = BBR_INITIAL_RTO;
4205 else
4206 t_rxtcur = TICKS_2_USEC(tp->t_rxtcur);
4207
4208 bbr_log_thresh_choice(bbr, cts, thresh, t_rxtcur, srtt, rsm, BBR_TO_FRM_TLP);
4209 /* Not above an RTO */
4210 if (thresh > t_rxtcur) {
4211 thresh = t_rxtcur;
4212 }
4213 /* Not above a RTO max */
4214 if (thresh > (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND)) {
4215 thresh = (((uint32_t)bbr->rc_max_rto_sec) * USECS_IN_SECOND);
4216 }
4217 /* And now apply the user TLP min */
4218 if (thresh < bbr_tlp_min) {
4219 thresh = bbr_tlp_min;
4220 }
4221 return (thresh);
4222 }
4223
4224 /*
4225 * Return one of three RTTs to use (in microseconds).
4226 */
4227 static __inline uint32_t
bbr_get_rtt(struct tcp_bbr * bbr,int32_t rtt_type)4228 bbr_get_rtt(struct tcp_bbr *bbr, int32_t rtt_type)
4229 {
4230 uint32_t f_rtt;
4231 uint32_t srtt;
4232
4233 f_rtt = get_filter_value_small(&bbr->r_ctl.rc_rttprop);
4234 if (get_filter_value_small(&bbr->r_ctl.rc_rttprop) == 0xffffffff) {
4235 /* We have no rtt at all */
4236 if (bbr->rc_tp->t_srtt == 0)
4237 f_rtt = BBR_INITIAL_RTO;
4238 else
4239 f_rtt = (TICKS_2_USEC(bbr->rc_tp->t_srtt) >> TCP_RTT_SHIFT);
4240 /*
4241 * Since we don't know how good the rtt is apply a
4242 * delayed-ack min
4243 */
4244 if (f_rtt < bbr_delayed_ack_time) {
4245 f_rtt = bbr_delayed_ack_time;
4246 }
4247 }
4248 /* Take the filter version or last measured pkt-rtt */
4249 if (rtt_type == BBR_RTT_PROP) {
4250 srtt = f_rtt;
4251 } else if (rtt_type == BBR_RTT_PKTRTT) {
4252 if (bbr->r_ctl.rc_pkt_epoch_rtt) {
4253 srtt = bbr->r_ctl.rc_pkt_epoch_rtt;
4254 } else {
4255 /* No pkt rtt yet */
4256 srtt = f_rtt;
4257 }
4258 } else if (rtt_type == BBR_RTT_RACK) {
4259 srtt = bbr->r_ctl.rc_last_rtt;
4260 /* We need to add in any internal delay for our timer */
4261 if (bbr->rc_ack_was_delayed)
4262 srtt += bbr->r_ctl.rc_ack_hdwr_delay;
4263 } else if (rtt_type == BBR_SRTT) {
4264 srtt = (TICKS_2_USEC(bbr->rc_tp->t_srtt) >> TCP_RTT_SHIFT);
4265 } else {
4266 /* TSNH */
4267 srtt = f_rtt;
4268 #ifdef BBR_INVARIANTS
4269 panic("Unknown rtt request type %d", rtt_type);
4270 #endif
4271 }
4272 return (srtt);
4273 }
4274
4275 static int
bbr_is_lost(struct tcp_bbr * bbr,struct bbr_sendmap * rsm,uint32_t cts)4276 bbr_is_lost(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, uint32_t cts)
4277 {
4278 uint32_t thresh;
4279
4280 thresh = bbr_calc_thresh_rack(bbr, bbr_get_rtt(bbr, BBR_RTT_RACK),
4281 cts, rsm);
4282 if ((cts - rsm->r_tim_lastsent[(rsm->r_rtr_cnt - 1)]) >= thresh) {
4283 /* It is lost (past time) */
4284 return (1);
4285 }
4286 return (0);
4287 }
4288
4289 /*
4290 * Return a sendmap if we need to retransmit something.
4291 */
4292 static struct bbr_sendmap *
bbr_check_recovery_mode(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)4293 bbr_check_recovery_mode(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4294 {
4295 /*
4296 * Check to see that we don't need to fall into recovery. We will
4297 * need to do so if our oldest transmit is past the time we should
4298 * have had an ack.
4299 */
4300
4301 struct bbr_sendmap *rsm;
4302 int32_t idx;
4303
4304 if (TAILQ_EMPTY(&bbr->r_ctl.rc_map)) {
4305 /* Nothing outstanding that we know of */
4306 return (NULL);
4307 }
4308 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
4309 if (rsm == NULL) {
4310 /* Nothing in the transmit map */
4311 return (NULL);
4312 }
4313 if (tp->t_flags & TF_SENTFIN) {
4314 /* Fin restricted, don't find anything once a fin is sent */
4315 return (NULL);
4316 }
4317 if (rsm->r_flags & BBR_ACKED) {
4318 /*
4319 * Ok the first one is acked (this really should not happen
4320 * since we remove the from the tmap once they are acked)
4321 */
4322 rsm = bbr_find_lowest_rsm(bbr);
4323 if (rsm == NULL)
4324 return (NULL);
4325 }
4326 idx = rsm->r_rtr_cnt - 1;
4327 if (SEQ_LEQ(cts, rsm->r_tim_lastsent[idx])) {
4328 /* Send timestamp is the same or less? can't be ready */
4329 return (NULL);
4330 }
4331 /* Get our RTT time */
4332 if (bbr_is_lost(bbr, rsm, cts) &&
4333 ((rsm->r_dupack >= DUP_ACK_THRESHOLD) ||
4334 (rsm->r_flags & BBR_SACK_PASSED))) {
4335 if ((rsm->r_flags & BBR_MARKED_LOST) == 0) {
4336 rsm->r_flags |= BBR_MARKED_LOST;
4337 bbr->r_ctl.rc_lost += rsm->r_end - rsm->r_start;
4338 bbr->r_ctl.rc_lost_bytes += rsm->r_end - rsm->r_start;
4339 }
4340 bbr_cong_signal(tp, NULL, CC_NDUPACK, rsm);
4341 #ifdef BBR_INVARIANTS
4342 if ((rsm->r_end - rsm->r_start) == 0)
4343 panic("tp:%p bbr:%p rsm:%p length is 0?", tp, bbr, rsm);
4344 #endif
4345 return (rsm);
4346 }
4347 return (NULL);
4348 }
4349
4350 /*
4351 * RACK Timer, here we simply do logging and house keeping.
4352 * the normal bbr_output_wtime() function will call the
4353 * appropriate thing to check if we need to do a RACK retransmit.
4354 * We return 1, saying don't proceed with bbr_output_wtime only
4355 * when all timers have been stopped (destroyed PCB?).
4356 */
4357 static int
bbr_timeout_rack(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)4358 bbr_timeout_rack(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4359 {
4360 /*
4361 * This timer simply provides an internal trigger to send out data.
4362 * The check_recovery_mode call will see if there are needed
4363 * retransmissions, if so we will enter fast-recovery. The output
4364 * call may or may not do the same thing depending on sysctl
4365 * settings.
4366 */
4367 uint32_t lost;
4368
4369 if (bbr->rc_all_timers_stopped) {
4370 return (1);
4371 }
4372 if (TSTMP_LT(cts, bbr->r_ctl.rc_timer_exp)) {
4373 /* Its not time yet */
4374 return (0);
4375 }
4376 BBR_STAT_INC(bbr_to_tot);
4377 lost = bbr->r_ctl.rc_lost;
4378 if (bbr->r_state && (bbr->r_state != tp->t_state))
4379 bbr_set_state(tp, bbr, 0);
4380 bbr_log_to_event(bbr, cts, BBR_TO_FRM_RACK);
4381 if (bbr->r_ctl.rc_resend == NULL) {
4382 /* Lets do the check here */
4383 bbr->r_ctl.rc_resend = bbr_check_recovery_mode(tp, bbr, cts);
4384 }
4385 if (bbr_policer_call_from_rack_to)
4386 bbr_lt_bw_sampling(bbr, cts, (bbr->r_ctl.rc_lost > lost));
4387 bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_RACK;
4388 return (0);
4389 }
4390
4391 static __inline void
bbr_clone_rsm(struct tcp_bbr * bbr,struct bbr_sendmap * nrsm,struct bbr_sendmap * rsm,uint32_t start)4392 bbr_clone_rsm(struct tcp_bbr *bbr, struct bbr_sendmap *nrsm, struct bbr_sendmap *rsm, uint32_t start)
4393 {
4394 int idx;
4395
4396 nrsm->r_start = start;
4397 nrsm->r_end = rsm->r_end;
4398 nrsm->r_rtr_cnt = rsm->r_rtr_cnt;
4399 nrsm-> r_rtt_not_allowed = rsm->r_rtt_not_allowed;
4400 nrsm->r_flags = rsm->r_flags;
4401 /* We don't transfer forward the SYN flag */
4402 nrsm->r_flags &= ~BBR_HAS_SYN;
4403 /* We move forward the FIN flag, not that this should happen */
4404 rsm->r_flags &= ~BBR_HAS_FIN;
4405 nrsm->r_dupack = rsm->r_dupack;
4406 nrsm->r_rtr_bytes = 0;
4407 nrsm->r_is_gain = rsm->r_is_gain;
4408 nrsm->r_is_drain = rsm->r_is_drain;
4409 nrsm->r_delivered = rsm->r_delivered;
4410 nrsm->r_ts_valid = rsm->r_ts_valid;
4411 nrsm->r_del_ack_ts = rsm->r_del_ack_ts;
4412 nrsm->r_del_time = rsm->r_del_time;
4413 nrsm->r_app_limited = rsm->r_app_limited;
4414 nrsm->r_first_sent_time = rsm->r_first_sent_time;
4415 nrsm->r_flight_at_send = rsm->r_flight_at_send;
4416 /* We split a piece the lower section looses any just_ret flag. */
4417 nrsm->r_bbr_state = rsm->r_bbr_state;
4418 for (idx = 0; idx < nrsm->r_rtr_cnt; idx++) {
4419 nrsm->r_tim_lastsent[idx] = rsm->r_tim_lastsent[idx];
4420 }
4421 rsm->r_end = nrsm->r_start;
4422 idx = min((bbr->rc_tp->t_maxseg - bbr->rc_last_options), bbr->r_ctl.rc_pace_max_segs);
4423 idx /= 8;
4424 /* Check if we got too small */
4425 if ((rsm->r_is_smallmap == 0) &&
4426 ((rsm->r_end - rsm->r_start) <= idx)) {
4427 bbr->r_ctl.rc_num_small_maps_alloced++;
4428 rsm->r_is_smallmap = 1;
4429 }
4430 /* Check the new one as well */
4431 if ((nrsm->r_end - nrsm->r_start) <= idx) {
4432 bbr->r_ctl.rc_num_small_maps_alloced++;
4433 nrsm->r_is_smallmap = 1;
4434 }
4435 }
4436
4437 static int
bbr_sack_mergable(struct bbr_sendmap * at,uint32_t start,uint32_t end)4438 bbr_sack_mergable(struct bbr_sendmap *at,
4439 uint32_t start, uint32_t end)
4440 {
4441 /*
4442 * Given a sack block defined by
4443 * start and end, and a current position
4444 * at. Return 1 if either side of at
4445 * would show that the block is mergable
4446 * to that side. A block to be mergable
4447 * must have overlap with the start/end
4448 * and be in the SACK'd state.
4449 */
4450 struct bbr_sendmap *l_rsm;
4451 struct bbr_sendmap *r_rsm;
4452
4453 /* first get the either side blocks */
4454 l_rsm = TAILQ_PREV(at, bbr_head, r_next);
4455 r_rsm = TAILQ_NEXT(at, r_next);
4456 if (l_rsm && (l_rsm->r_flags & BBR_ACKED)) {
4457 /* Potentially mergeable */
4458 if ((l_rsm->r_end == start) ||
4459 (SEQ_LT(start, l_rsm->r_end) &&
4460 SEQ_GT(end, l_rsm->r_end))) {
4461 /*
4462 * map blk |------|
4463 * sack blk |------|
4464 * <or>
4465 * map blk |------|
4466 * sack blk |------|
4467 */
4468 return (1);
4469 }
4470 }
4471 if (r_rsm && (r_rsm->r_flags & BBR_ACKED)) {
4472 /* Potentially mergeable */
4473 if ((r_rsm->r_start == end) ||
4474 (SEQ_LT(start, r_rsm->r_start) &&
4475 SEQ_GT(end, r_rsm->r_start))) {
4476 /*
4477 * map blk |---------|
4478 * sack blk |----|
4479 * <or>
4480 * map blk |---------|
4481 * sack blk |-------|
4482 */
4483 return (1);
4484 }
4485 }
4486 return (0);
4487 }
4488
4489 static struct bbr_sendmap *
bbr_merge_rsm(struct tcp_bbr * bbr,struct bbr_sendmap * l_rsm,struct bbr_sendmap * r_rsm)4490 bbr_merge_rsm(struct tcp_bbr *bbr,
4491 struct bbr_sendmap *l_rsm,
4492 struct bbr_sendmap *r_rsm)
4493 {
4494 /*
4495 * We are merging two ack'd RSM's,
4496 * the l_rsm is on the left (lower seq
4497 * values) and the r_rsm is on the right
4498 * (higher seq value). The simplest way
4499 * to merge these is to move the right
4500 * one into the left. I don't think there
4501 * is any reason we need to try to find
4502 * the oldest (or last oldest retransmitted).
4503 */
4504 l_rsm->r_end = r_rsm->r_end;
4505 if (l_rsm->r_dupack < r_rsm->r_dupack)
4506 l_rsm->r_dupack = r_rsm->r_dupack;
4507 if (r_rsm->r_rtr_bytes)
4508 l_rsm->r_rtr_bytes += r_rsm->r_rtr_bytes;
4509 if (r_rsm->r_in_tmap) {
4510 /* This really should not happen */
4511 TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, r_rsm, r_tnext);
4512 }
4513 if (r_rsm->r_app_limited)
4514 l_rsm->r_app_limited = r_rsm->r_app_limited;
4515 /* Now the flags */
4516 if (r_rsm->r_flags & BBR_HAS_FIN)
4517 l_rsm->r_flags |= BBR_HAS_FIN;
4518 if (r_rsm->r_flags & BBR_TLP)
4519 l_rsm->r_flags |= BBR_TLP;
4520 if (r_rsm->r_flags & BBR_RWND_COLLAPSED)
4521 l_rsm->r_flags |= BBR_RWND_COLLAPSED;
4522 if (r_rsm->r_flags & BBR_MARKED_LOST) {
4523 /* This really should not happen */
4524 bbr->r_ctl.rc_lost_bytes -= r_rsm->r_end - r_rsm->r_start;
4525 }
4526 TAILQ_REMOVE(&bbr->r_ctl.rc_map, r_rsm, r_next);
4527 if ((r_rsm->r_limit_type == 0) && (l_rsm->r_limit_type != 0)) {
4528 /* Transfer the split limit to the map we free */
4529 r_rsm->r_limit_type = l_rsm->r_limit_type;
4530 l_rsm->r_limit_type = 0;
4531 }
4532 bbr_free(bbr, r_rsm);
4533 return(l_rsm);
4534 }
4535
4536 /*
4537 * TLP Timer, here we simply setup what segment we want to
4538 * have the TLP expire on, the normal bbr_output_wtime() will then
4539 * send it out.
4540 *
4541 * We return 1, saying don't proceed with bbr_output_wtime only
4542 * when all timers have been stopped (destroyed PCB?).
4543 */
4544 static int
bbr_timeout_tlp(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)4545 bbr_timeout_tlp(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4546 {
4547 /*
4548 * Tail Loss Probe.
4549 */
4550 struct bbr_sendmap *rsm = NULL;
4551 struct socket *so;
4552 uint32_t amm;
4553 uint32_t out, avail;
4554 uint32_t maxseg;
4555 int collapsed_win = 0;
4556
4557 if (bbr->rc_all_timers_stopped) {
4558 return (1);
4559 }
4560 if (TSTMP_LT(cts, bbr->r_ctl.rc_timer_exp)) {
4561 /* Its not time yet */
4562 return (0);
4563 }
4564 if (ctf_progress_timeout_check(tp, true)) {
4565 bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
4566 return (-ETIMEDOUT); /* tcp_drop() */
4567 }
4568 /* Did we somehow get into persists? */
4569 if (bbr->rc_in_persist) {
4570 return (0);
4571 }
4572 if (bbr->r_state && (bbr->r_state != tp->t_state))
4573 bbr_set_state(tp, bbr, 0);
4574 BBR_STAT_INC(bbr_tlp_tot);
4575 maxseg = tp->t_maxseg - bbr->rc_last_options;
4576 /*
4577 * A TLP timer has expired. We have been idle for 2 rtts. So we now
4578 * need to figure out how to force a full MSS segment out.
4579 */
4580 so = tptosocket(tp);
4581 avail = sbavail(&so->so_snd);
4582 out = ctf_outstanding(tp);
4583 if (out > tp->snd_wnd) {
4584 /* special case, we need a retransmission */
4585 collapsed_win = 1;
4586 goto need_retran;
4587 }
4588 if (avail > out) {
4589 /* New data is available */
4590 amm = avail - out;
4591 if (amm > maxseg) {
4592 amm = maxseg;
4593 } else if ((amm < maxseg) && ((tp->t_flags & TF_NODELAY) == 0)) {
4594 /* not enough to fill a MTU and no-delay is off */
4595 goto need_retran;
4596 }
4597 /* Set the send-new override */
4598 if ((out + amm) <= tp->snd_wnd) {
4599 bbr->rc_tlp_new_data = 1;
4600 } else {
4601 goto need_retran;
4602 }
4603 bbr->r_ctl.rc_tlp_seg_send_cnt = 0;
4604 bbr->r_ctl.rc_last_tlp_seq = tp->snd_max;
4605 bbr->r_ctl.rc_tlp_send = NULL;
4606 /* cap any slots */
4607 BBR_STAT_INC(bbr_tlp_newdata);
4608 goto send;
4609 }
4610 need_retran:
4611 /*
4612 * Ok we need to arrange the last un-acked segment to be re-sent, or
4613 * optionally the first un-acked segment.
4614 */
4615 if (collapsed_win == 0) {
4616 rsm = TAILQ_LAST_FAST(&bbr->r_ctl.rc_map, bbr_sendmap, r_next);
4617 if (rsm && (BBR_ACKED | BBR_HAS_FIN)) {
4618 rsm = bbr_find_high_nonack(bbr, rsm);
4619 }
4620 if (rsm == NULL) {
4621 goto restore;
4622 }
4623 } else {
4624 /*
4625 * We must find the last segment
4626 * that was acceptable by the client.
4627 */
4628 TAILQ_FOREACH_REVERSE(rsm, &bbr->r_ctl.rc_map, bbr_head, r_next) {
4629 if ((rsm->r_flags & BBR_RWND_COLLAPSED) == 0) {
4630 /* Found one */
4631 break;
4632 }
4633 }
4634 if (rsm == NULL) {
4635 /* None? if so send the first */
4636 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
4637 if (rsm == NULL)
4638 goto restore;
4639 }
4640 }
4641 if ((rsm->r_end - rsm->r_start) > maxseg) {
4642 /*
4643 * We need to split this the last segment in two.
4644 */
4645 struct bbr_sendmap *nrsm;
4646
4647 nrsm = bbr_alloc_full_limit(bbr);
4648 if (nrsm == NULL) {
4649 /*
4650 * We can't get memory to split, we can either just
4651 * not split it. Or retransmit the whole piece, lets
4652 * do the large send (BTLP :-) ).
4653 */
4654 goto go_for_it;
4655 }
4656 bbr_clone_rsm(bbr, nrsm, rsm, (rsm->r_end - maxseg));
4657 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
4658 if (rsm->r_in_tmap) {
4659 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
4660 nrsm->r_in_tmap = 1;
4661 }
4662 rsm->r_flags &= (~BBR_HAS_FIN);
4663 rsm = nrsm;
4664 }
4665 go_for_it:
4666 bbr->r_ctl.rc_tlp_send = rsm;
4667 bbr->rc_tlp_rtx_out = 1;
4668 if (rsm->r_start == bbr->r_ctl.rc_last_tlp_seq) {
4669 bbr->r_ctl.rc_tlp_seg_send_cnt++;
4670 tp->t_rxtshift++;
4671 } else {
4672 bbr->r_ctl.rc_last_tlp_seq = rsm->r_start;
4673 bbr->r_ctl.rc_tlp_seg_send_cnt = 1;
4674 }
4675 send:
4676 if (bbr->r_ctl.rc_tlp_seg_send_cnt > bbr_tlp_max_resend) {
4677 /*
4678 * Can't [re]/transmit a segment we have retransmitted the
4679 * max times. We need the retransmit timer to take over.
4680 */
4681 restore:
4682 bbr->rc_tlp_new_data = 0;
4683 bbr->r_ctl.rc_tlp_send = NULL;
4684 if (rsm)
4685 rsm->r_flags &= ~BBR_TLP;
4686 BBR_STAT_INC(bbr_tlp_retran_fail);
4687 return (0);
4688 } else if (rsm) {
4689 rsm->r_flags |= BBR_TLP;
4690 }
4691 if (rsm && (rsm->r_start == bbr->r_ctl.rc_last_tlp_seq) &&
4692 (bbr->r_ctl.rc_tlp_seg_send_cnt > bbr_tlp_max_resend)) {
4693 /*
4694 * We have retransmitted to many times for TLP. Switch to
4695 * the regular RTO timer
4696 */
4697 goto restore;
4698 }
4699 bbr_log_to_event(bbr, cts, BBR_TO_FRM_TLP);
4700 bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_TLP;
4701 return (0);
4702 }
4703
4704 /*
4705 * Delayed ack Timer, here we simply need to setup the
4706 * ACK_NOW flag and remove the DELACK flag. From there
4707 * the output routine will send the ack out.
4708 *
4709 * We only return 1, saying don't proceed, if all timers
4710 * are stopped (destroyed PCB?).
4711 */
4712 static int
bbr_timeout_delack(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)4713 bbr_timeout_delack(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4714 {
4715 if (bbr->rc_all_timers_stopped) {
4716 return (1);
4717 }
4718 bbr_log_to_event(bbr, cts, BBR_TO_FRM_DELACK);
4719 tp->t_flags &= ~TF_DELACK;
4720 tp->t_flags |= TF_ACKNOW;
4721 KMOD_TCPSTAT_INC(tcps_delack);
4722 bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_DELACK;
4723 return (0);
4724 }
4725
4726 /*
4727 * Here we send a KEEP-ALIVE like probe to the
4728 * peer, we do not send data.
4729 *
4730 * We only return 1, saying don't proceed, if all timers
4731 * are stopped (destroyed PCB?).
4732 */
4733 static int
bbr_timeout_persist(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)4734 bbr_timeout_persist(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4735 {
4736 struct tcptemp *t_template;
4737 int32_t retval = 1;
4738
4739 if (bbr->rc_all_timers_stopped) {
4740 return (1);
4741 }
4742 if (bbr->rc_in_persist == 0)
4743 return (0);
4744
4745 /*
4746 * Persistence timer into zero window. Force a byte to be output, if
4747 * possible.
4748 */
4749 bbr_log_to_event(bbr, cts, BBR_TO_FRM_PERSIST);
4750 bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_PERSIT;
4751 KMOD_TCPSTAT_INC(tcps_persisttimeo);
4752 /*
4753 * Have we exceeded the user specified progress time?
4754 */
4755 if (ctf_progress_timeout_check(tp, true)) {
4756 bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
4757 return (-ETIMEDOUT); /* tcp_drop() */
4758 }
4759 /*
4760 * Hack: if the peer is dead/unreachable, we do not time out if the
4761 * window is closed. After a full backoff, drop the connection if
4762 * the idle time (no responses to probes) reaches the maximum
4763 * backoff that we would use if retransmitting.
4764 */
4765 if (tp->t_rxtshift >= V_tcp_retries &&
4766 (ticks - tp->t_rcvtime >= tcp_maxpersistidle ||
4767 ticks - tp->t_rcvtime >= TCP_REXMTVAL(tp) * tcp_totbackoff)) {
4768 KMOD_TCPSTAT_INC(tcps_persistdrop);
4769 tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
4770 return (-ETIMEDOUT); /* tcp_drop() */
4771 }
4772 if ((sbavail(&bbr->rc_inp->inp_socket->so_snd) == 0) &&
4773 tp->snd_una == tp->snd_max) {
4774 bbr_exit_persist(tp, bbr, cts, __LINE__);
4775 retval = 0;
4776 goto out;
4777 }
4778 /*
4779 * If the user has closed the socket then drop a persisting
4780 * connection after a much reduced timeout.
4781 */
4782 if (tp->t_state > TCPS_CLOSE_WAIT &&
4783 (ticks - tp->t_rcvtime) >= TCPTV_PERSMAX) {
4784 KMOD_TCPSTAT_INC(tcps_persistdrop);
4785 tcp_log_end_status(tp, TCP_EI_STATUS_PERSIST_MAX);
4786 return (-ETIMEDOUT); /* tcp_drop() */
4787 }
4788 t_template = tcpip_maketemplate(bbr->rc_inp);
4789 if (t_template) {
4790 tcp_respond(tp, t_template->tt_ipgen,
4791 &t_template->tt_t, (struct mbuf *)NULL,
4792 tp->rcv_nxt, tp->snd_una - 1, 0);
4793 /* This sends an ack */
4794 if (tp->t_flags & TF_DELACK)
4795 tp->t_flags &= ~TF_DELACK;
4796 free(t_template, M_TEMP);
4797 }
4798 if (tp->t_rxtshift < V_tcp_retries)
4799 tp->t_rxtshift++;
4800 bbr_start_hpts_timer(bbr, tp, cts, 3, 0, 0);
4801 out:
4802 return (retval);
4803 }
4804
4805 /*
4806 * If a keepalive goes off, we had no other timers
4807 * happening. We always return 1 here since this
4808 * routine either drops the connection or sends
4809 * out a segment with respond.
4810 */
4811 static int
bbr_timeout_keepalive(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)4812 bbr_timeout_keepalive(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4813 {
4814 struct tcptemp *t_template;
4815 struct inpcb *inp = tptoinpcb(tp);
4816
4817 if (bbr->rc_all_timers_stopped) {
4818 return (1);
4819 }
4820 bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_KEEP;
4821 bbr_log_to_event(bbr, cts, BBR_TO_FRM_KEEP);
4822 /*
4823 * Keep-alive timer went off; send something or drop connection if
4824 * idle for too long.
4825 */
4826 KMOD_TCPSTAT_INC(tcps_keeptimeo);
4827 if (tp->t_state < TCPS_ESTABLISHED)
4828 goto dropit;
4829 if ((V_tcp_always_keepalive || inp->inp_socket->so_options & SO_KEEPALIVE) &&
4830 tp->t_state <= TCPS_CLOSING) {
4831 if (ticks - tp->t_rcvtime >= TP_KEEPIDLE(tp) + TP_MAXIDLE(tp))
4832 goto dropit;
4833 /*
4834 * Send a packet designed to force a response if the peer is
4835 * up and reachable: either an ACK if the connection is
4836 * still alive, or an RST if the peer has closed the
4837 * connection due to timeout or reboot. Using sequence
4838 * number tp->snd_una-1 causes the transmitted zero-length
4839 * segment to lie outside the receive window; by the
4840 * protocol spec, this requires the correspondent TCP to
4841 * respond.
4842 */
4843 KMOD_TCPSTAT_INC(tcps_keepprobe);
4844 t_template = tcpip_maketemplate(inp);
4845 if (t_template) {
4846 tcp_respond(tp, t_template->tt_ipgen,
4847 &t_template->tt_t, (struct mbuf *)NULL,
4848 tp->rcv_nxt, tp->snd_una - 1, 0);
4849 free(t_template, M_TEMP);
4850 }
4851 }
4852 bbr_start_hpts_timer(bbr, tp, cts, 4, 0, 0);
4853 return (1);
4854 dropit:
4855 KMOD_TCPSTAT_INC(tcps_keepdrops);
4856 tcp_log_end_status(tp, TCP_EI_STATUS_KEEP_MAX);
4857 return (-ETIMEDOUT); /* tcp_drop() */
4858 }
4859
4860 /*
4861 * Retransmit helper function, clear up all the ack
4862 * flags and take care of important book keeping.
4863 */
4864 static void
bbr_remxt_tmr(struct tcpcb * tp)4865 bbr_remxt_tmr(struct tcpcb *tp)
4866 {
4867 /*
4868 * The retransmit timer went off, all sack'd blocks must be
4869 * un-acked.
4870 */
4871 struct bbr_sendmap *rsm, *trsm = NULL;
4872 struct tcp_bbr *bbr;
4873 uint32_t cts, lost;
4874
4875 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
4876 cts = tcp_get_usecs(&bbr->rc_tv);
4877 lost = bbr->r_ctl.rc_lost;
4878 if (bbr->r_state && (bbr->r_state != tp->t_state))
4879 bbr_set_state(tp, bbr, 0);
4880
4881 TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_map, r_next) {
4882 if (rsm->r_flags & BBR_ACKED) {
4883 uint32_t old_flags;
4884
4885 rsm->r_dupack = 0;
4886 if (rsm->r_in_tmap == 0) {
4887 /* We must re-add it back to the tlist */
4888 if (trsm == NULL) {
4889 TAILQ_INSERT_HEAD(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
4890 } else {
4891 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, trsm, rsm, r_tnext);
4892 }
4893 rsm->r_in_tmap = 1;
4894 }
4895 old_flags = rsm->r_flags;
4896 rsm->r_flags |= BBR_RXT_CLEARED;
4897 rsm->r_flags &= ~(BBR_ACKED | BBR_SACK_PASSED | BBR_WAS_SACKPASS);
4898 bbr_log_type_rsmclear(bbr, cts, rsm, old_flags, __LINE__);
4899 } else {
4900 if ((tp->t_state < TCPS_ESTABLISHED) &&
4901 (rsm->r_start == tp->snd_una)) {
4902 /*
4903 * Special case for TCP FO. Where
4904 * we sent more data beyond the snd_max.
4905 * We don't mark that as lost and stop here.
4906 */
4907 break;
4908 }
4909 if ((rsm->r_flags & BBR_MARKED_LOST) == 0) {
4910 bbr->r_ctl.rc_lost += rsm->r_end - rsm->r_start;
4911 bbr->r_ctl.rc_lost_bytes += rsm->r_end - rsm->r_start;
4912 }
4913 if (bbr_marks_rxt_sack_passed) {
4914 /*
4915 * With this option, we will rack out
4916 * in 1ms increments the rest of the packets.
4917 */
4918 rsm->r_flags |= BBR_SACK_PASSED | BBR_MARKED_LOST;
4919 rsm->r_flags &= ~BBR_WAS_SACKPASS;
4920 } else {
4921 /*
4922 * With this option we only mark them lost
4923 * and remove all sack'd markings. We will run
4924 * another RXT or a TLP. This will cause
4925 * us to eventually send more based on what
4926 * ack's come in.
4927 */
4928 rsm->r_flags |= BBR_MARKED_LOST;
4929 rsm->r_flags &= ~BBR_WAS_SACKPASS;
4930 rsm->r_flags &= ~BBR_SACK_PASSED;
4931 }
4932 }
4933 trsm = rsm;
4934 }
4935 bbr->r_ctl.rc_resend = TAILQ_FIRST(&bbr->r_ctl.rc_map);
4936 /* Clear the count (we just un-acked them) */
4937 bbr_log_to_event(bbr, cts, BBR_TO_FRM_TMR);
4938 bbr->rc_tlp_new_data = 0;
4939 bbr->r_ctl.rc_tlp_seg_send_cnt = 0;
4940 /* zap the behindness on a rxt */
4941 bbr->r_ctl.rc_hptsi_agg_delay = 0;
4942 bbr->r_agg_early_set = 0;
4943 bbr->r_ctl.rc_agg_early = 0;
4944 bbr->rc_tlp_rtx_out = 0;
4945 bbr->r_ctl.rc_sacked = 0;
4946 bbr->r_ctl.rc_sacklast = NULL;
4947 bbr->r_timer_override = 1;
4948 bbr_lt_bw_sampling(bbr, cts, (bbr->r_ctl.rc_lost > lost));
4949 }
4950
4951 /*
4952 * Re-transmit timeout! If we drop the PCB we will return 1, otherwise
4953 * we will setup to retransmit the lowest seq number outstanding.
4954 */
4955 static int
bbr_timeout_rxt(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)4956 bbr_timeout_rxt(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
4957 {
4958 struct inpcb *inp = tptoinpcb(tp);
4959 int32_t rexmt;
4960 int32_t retval = 0;
4961 bool isipv6;
4962
4963 bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_RXT;
4964 if (bbr->rc_all_timers_stopped) {
4965 return (1);
4966 }
4967 if (TCPS_HAVEESTABLISHED(tp->t_state) &&
4968 (tp->snd_una == tp->snd_max)) {
4969 /* Nothing outstanding .. nothing to do */
4970 return (0);
4971 }
4972 /*
4973 * Retransmission timer went off. Message has not been acked within
4974 * retransmit interval. Back off to a longer retransmit interval
4975 * and retransmit one segment.
4976 */
4977 if (ctf_progress_timeout_check(tp, true)) {
4978 bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
4979 return (-ETIMEDOUT); /* tcp_drop() */
4980 }
4981 bbr_remxt_tmr(tp);
4982 if ((bbr->r_ctl.rc_resend == NULL) ||
4983 ((bbr->r_ctl.rc_resend->r_flags & BBR_RWND_COLLAPSED) == 0)) {
4984 /*
4985 * If the rwnd collapsed on
4986 * the one we are retransmitting
4987 * it does not count against the
4988 * rxt count.
4989 */
4990 tp->t_rxtshift++;
4991 }
4992 if (tp->t_rxtshift > V_tcp_retries) {
4993 tp->t_rxtshift = V_tcp_retries;
4994 KMOD_TCPSTAT_INC(tcps_timeoutdrop);
4995 tcp_log_end_status(tp, TCP_EI_STATUS_RETRAN);
4996 /* XXXGL: previously t_softerror was casted to uint16_t */
4997 MPASS(tp->t_softerror >= 0);
4998 retval = tp->t_softerror ? -tp->t_softerror : -ETIMEDOUT;
4999 return (retval); /* tcp_drop() */
5000 }
5001 if (tp->t_state == TCPS_SYN_SENT) {
5002 /*
5003 * If the SYN was retransmitted, indicate CWND to be limited
5004 * to 1 segment in cc_conn_init().
5005 */
5006 tp->snd_cwnd = 1;
5007 } else if (tp->t_rxtshift == 1) {
5008 /*
5009 * first retransmit; record ssthresh and cwnd so they can be
5010 * recovered if this turns out to be a "bad" retransmit. A
5011 * retransmit is considered "bad" if an ACK for this segment
5012 * is received within RTT/2 interval; the assumption here is
5013 * that the ACK was already in flight. See "On Estimating
5014 * End-to-End Network Path Properties" by Allman and Paxson
5015 * for more details.
5016 */
5017 tp->snd_cwnd = tp->t_maxseg - bbr->rc_last_options;
5018 if (!IN_RECOVERY(tp->t_flags)) {
5019 tp->snd_cwnd_prev = tp->snd_cwnd;
5020 tp->snd_ssthresh_prev = tp->snd_ssthresh;
5021 tp->snd_recover_prev = tp->snd_recover;
5022 tp->t_badrxtwin = ticks + (tp->t_srtt >> (TCP_RTT_SHIFT + 1));
5023 tp->t_flags |= TF_PREVVALID;
5024 } else {
5025 tp->t_flags &= ~TF_PREVVALID;
5026 }
5027 tp->snd_cwnd = tp->t_maxseg - bbr->rc_last_options;
5028 } else {
5029 tp->snd_cwnd = tp->t_maxseg - bbr->rc_last_options;
5030 tp->t_flags &= ~TF_PREVVALID;
5031 }
5032 KMOD_TCPSTAT_INC(tcps_rexmttimeo);
5033 if ((tp->t_state == TCPS_SYN_SENT) ||
5034 (tp->t_state == TCPS_SYN_RECEIVED))
5035 rexmt = USEC_2_TICKS(BBR_INITIAL_RTO) * tcp_backoff[tp->t_rxtshift];
5036 else
5037 rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift];
5038 TCPT_RANGESET(tp->t_rxtcur, rexmt,
5039 MSEC_2_TICKS(bbr->r_ctl.rc_min_rto_ms),
5040 MSEC_2_TICKS(((uint32_t)bbr->rc_max_rto_sec) * 1000));
5041 /*
5042 * We enter the path for PLMTUD if connection is established or, if
5043 * connection is FIN_WAIT_1 status, reason for the last is that if
5044 * amount of data we send is very small, we could send it in couple
5045 * of packets and process straight to FIN. In that case we won't
5046 * catch ESTABLISHED state.
5047 */
5048 #ifdef INET6
5049 isipv6 = (inp->inp_vflag & INP_IPV6) ? true : false;
5050 #else
5051 isipv6 = false;
5052 #endif
5053 if (((V_tcp_pmtud_blackhole_detect == 1) ||
5054 (V_tcp_pmtud_blackhole_detect == 2 && !isipv6) ||
5055 (V_tcp_pmtud_blackhole_detect == 3 && isipv6)) &&
5056 ((tp->t_state == TCPS_ESTABLISHED) ||
5057 (tp->t_state == TCPS_FIN_WAIT_1))) {
5058 /*
5059 * Idea here is that at each stage of mtu probe (usually,
5060 * 1448 -> 1188 -> 524) should be given 2 chances to recover
5061 * before further clamping down. 'tp->t_rxtshift % 2 == 0'
5062 * should take care of that.
5063 */
5064 if (((tp->t_flags2 & (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) ==
5065 (TF2_PLPMTU_PMTUD | TF2_PLPMTU_MAXSEGSNT)) &&
5066 (tp->t_rxtshift >= 2 && tp->t_rxtshift < 6 &&
5067 tp->t_rxtshift % 2 == 0)) {
5068 /*
5069 * Enter Path MTU Black-hole Detection mechanism: -
5070 * Disable Path MTU Discovery (IP "DF" bit). -
5071 * Reduce MTU to lower value than what we negotiated
5072 * with peer.
5073 */
5074 if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) == 0) {
5075 /*
5076 * Record that we may have found a black
5077 * hole.
5078 */
5079 tp->t_flags2 |= TF2_PLPMTU_BLACKHOLE;
5080 /* Keep track of previous MSS. */
5081 tp->t_pmtud_saved_maxseg = tp->t_maxseg;
5082 }
5083 /*
5084 * Reduce the MSS to blackhole value or to the
5085 * default in an attempt to retransmit.
5086 */
5087 #ifdef INET6
5088 isipv6 = bbr->r_is_v6;
5089 if (isipv6 &&
5090 tp->t_maxseg > V_tcp_v6pmtud_blackhole_mss) {
5091 /* Use the sysctl tuneable blackhole MSS. */
5092 tp->t_maxseg = V_tcp_v6pmtud_blackhole_mss;
5093 KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
5094 } else if (isipv6) {
5095 /* Use the default MSS. */
5096 tp->t_maxseg = V_tcp_v6mssdflt;
5097 /*
5098 * Disable Path MTU Discovery when we switch
5099 * to minmss.
5100 */
5101 tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
5102 KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
5103 }
5104 #endif
5105 #if defined(INET6) && defined(INET)
5106 else
5107 #endif
5108 #ifdef INET
5109 if (tp->t_maxseg > V_tcp_pmtud_blackhole_mss) {
5110 /* Use the sysctl tuneable blackhole MSS. */
5111 tp->t_maxseg = V_tcp_pmtud_blackhole_mss;
5112 KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated);
5113 } else {
5114 /* Use the default MSS. */
5115 tp->t_maxseg = V_tcp_mssdflt;
5116 /*
5117 * Disable Path MTU Discovery when we switch
5118 * to minmss.
5119 */
5120 tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
5121 KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_activated_min_mss);
5122 }
5123 #endif
5124 } else {
5125 /*
5126 * If further retransmissions are still unsuccessful
5127 * with a lowered MTU, maybe this isn't a blackhole
5128 * and we restore the previous MSS and blackhole
5129 * detection flags. The limit '6' is determined by
5130 * giving each probe stage (1448, 1188, 524) 2
5131 * chances to recover.
5132 */
5133 if ((tp->t_flags2 & TF2_PLPMTU_BLACKHOLE) &&
5134 (tp->t_rxtshift >= 6)) {
5135 tp->t_flags2 |= TF2_PLPMTU_PMTUD;
5136 tp->t_flags2 &= ~TF2_PLPMTU_BLACKHOLE;
5137 tp->t_maxseg = tp->t_pmtud_saved_maxseg;
5138 if (tp->t_maxseg < V_tcp_mssdflt) {
5139 /*
5140 * The MSS is so small we should not
5141 * process incoming SACK's since we are
5142 * subject to attack in such a case.
5143 */
5144 tp->t_flags2 |= TF2_PROC_SACK_PROHIBIT;
5145 } else {
5146 tp->t_flags2 &= ~TF2_PROC_SACK_PROHIBIT;
5147 }
5148 KMOD_TCPSTAT_INC(tcps_pmtud_blackhole_failed);
5149 }
5150 }
5151 }
5152 /*
5153 * Disable RFC1323 and SACK if we haven't got any response to our
5154 * third SYN to work-around some broken terminal servers (most of
5155 * which have hopefully been retired) that have bad VJ header
5156 * compression code which trashes TCP segments containing
5157 * unknown-to-them TCP options.
5158 */
5159 if (tcp_rexmit_drop_options && (tp->t_state == TCPS_SYN_SENT) &&
5160 (tp->t_rxtshift == 3))
5161 tp->t_flags &= ~(TF_REQ_SCALE | TF_REQ_TSTMP | TF_SACK_PERMIT);
5162 /*
5163 * If we backed off this far, our srtt estimate is probably bogus.
5164 * Clobber it so we'll take the next rtt measurement as our srtt;
5165 * move the current srtt into rttvar to keep the current retransmit
5166 * times until then.
5167 */
5168 if (tp->t_rxtshift > TCP_MAXRXTSHIFT / 4) {
5169 #ifdef INET6
5170 if (bbr->r_is_v6)
5171 in6_losing(inp);
5172 else
5173 #endif
5174 in_losing(inp);
5175 tp->t_rttvar += (tp->t_srtt >> TCP_RTT_SHIFT);
5176 tp->t_srtt = 0;
5177 }
5178 sack_filter_clear(&bbr->r_ctl.bbr_sf, tp->snd_una);
5179 tp->snd_recover = tp->snd_max;
5180 tp->t_flags |= TF_ACKNOW;
5181 tp->t_rtttime = 0;
5182
5183 return (retval);
5184 }
5185
5186 static int
bbr_process_timers(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts,uint8_t hpts_calling)5187 bbr_process_timers(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts, uint8_t hpts_calling)
5188 {
5189 int32_t ret = 0;
5190 int32_t timers = (bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK);
5191
5192 if (timers == 0) {
5193 return (0);
5194 }
5195 if (tp->t_state == TCPS_LISTEN) {
5196 /* no timers on listen sockets */
5197 if (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)
5198 return (0);
5199 return (1);
5200 }
5201 if (TSTMP_LT(cts, bbr->r_ctl.rc_timer_exp)) {
5202 uint32_t left;
5203
5204 if (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
5205 ret = -1;
5206 bbr_log_to_processing(bbr, cts, ret, 0, hpts_calling);
5207 return (0);
5208 }
5209 if (hpts_calling == 0) {
5210 ret = -2;
5211 bbr_log_to_processing(bbr, cts, ret, 0, hpts_calling);
5212 return (0);
5213 }
5214 /*
5215 * Ok our timer went off early and we are not paced false
5216 * alarm, go back to sleep.
5217 */
5218 left = bbr->r_ctl.rc_timer_exp - cts;
5219 ret = -3;
5220 bbr_log_to_processing(bbr, cts, ret, left, hpts_calling);
5221 tcp_hpts_insert(tp, HPTS_USEC_TO_SLOTS(left));
5222 return (1);
5223 }
5224 bbr->rc_tmr_stopped = 0;
5225 bbr->r_ctl.rc_hpts_flags &= ~PACE_TMR_MASK;
5226 if (timers & PACE_TMR_DELACK) {
5227 ret = bbr_timeout_delack(tp, bbr, cts);
5228 } else if (timers & PACE_TMR_PERSIT) {
5229 ret = bbr_timeout_persist(tp, bbr, cts);
5230 } else if (timers & PACE_TMR_RACK) {
5231 bbr->r_ctl.rc_tlp_rxt_last_time = cts;
5232 ret = bbr_timeout_rack(tp, bbr, cts);
5233 } else if (timers & PACE_TMR_TLP) {
5234 bbr->r_ctl.rc_tlp_rxt_last_time = cts;
5235 ret = bbr_timeout_tlp(tp, bbr, cts);
5236 } else if (timers & PACE_TMR_RXT) {
5237 bbr->r_ctl.rc_tlp_rxt_last_time = cts;
5238 ret = bbr_timeout_rxt(tp, bbr, cts);
5239 } else if (timers & PACE_TMR_KEEP) {
5240 ret = bbr_timeout_keepalive(tp, bbr, cts);
5241 }
5242 bbr_log_to_processing(bbr, cts, ret, timers, hpts_calling);
5243 return (ret);
5244 }
5245
5246 static void
bbr_timer_cancel(struct tcp_bbr * bbr,int32_t line,uint32_t cts)5247 bbr_timer_cancel(struct tcp_bbr *bbr, int32_t line, uint32_t cts)
5248 {
5249 if (bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
5250 uint8_t hpts_removed = 0;
5251
5252 if (tcp_in_hpts(bbr->rc_tp) &&
5253 (bbr->rc_timer_first == 1)) {
5254 /*
5255 * If we are canceling timer's when we have the
5256 * timer ahead of the output being paced. We also
5257 * must remove ourselves from the hpts.
5258 */
5259 hpts_removed = 1;
5260 tcp_hpts_remove(bbr->rc_tp);
5261 if (bbr->r_ctl.rc_last_delay_val) {
5262 /* Update the last hptsi delay too */
5263 uint32_t time_since_send;
5264
5265 if (TSTMP_GT(cts, bbr->rc_pacer_started))
5266 time_since_send = cts - bbr->rc_pacer_started;
5267 else
5268 time_since_send = 0;
5269 if (bbr->r_ctl.rc_last_delay_val > time_since_send) {
5270 /* Cut down our slot time */
5271 bbr->r_ctl.rc_last_delay_val -= time_since_send;
5272 } else {
5273 bbr->r_ctl.rc_last_delay_val = 0;
5274 }
5275 bbr->rc_pacer_started = cts;
5276 }
5277 }
5278 bbr->rc_timer_first = 0;
5279 bbr_log_to_cancel(bbr, line, cts, hpts_removed);
5280 bbr->rc_tmr_stopped = bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK;
5281 bbr->r_ctl.rc_hpts_flags &= ~(PACE_TMR_MASK);
5282 }
5283 }
5284
5285 static int
bbr_stopall(struct tcpcb * tp)5286 bbr_stopall(struct tcpcb *tp)
5287 {
5288 struct tcp_bbr *bbr;
5289
5290 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
5291 bbr->rc_all_timers_stopped = 1;
5292
5293 tcp_hpts_remove(tp);
5294
5295 return (0);
5296 }
5297
5298 static uint32_t
bbr_get_earliest_send_outstanding(struct tcp_bbr * bbr,struct bbr_sendmap * u_rsm,uint32_t cts)5299 bbr_get_earliest_send_outstanding(struct tcp_bbr *bbr, struct bbr_sendmap *u_rsm, uint32_t cts)
5300 {
5301 struct bbr_sendmap *rsm;
5302
5303 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
5304 if ((rsm == NULL) || (u_rsm == rsm))
5305 return (cts);
5306 return(rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)]);
5307 }
5308
5309 static void
bbr_update_rsm(struct tcpcb * tp,struct tcp_bbr * bbr,struct bbr_sendmap * rsm,uint32_t cts,uint32_t pacing_time)5310 bbr_update_rsm(struct tcpcb *tp, struct tcp_bbr *bbr,
5311 struct bbr_sendmap *rsm, uint32_t cts, uint32_t pacing_time)
5312 {
5313 int32_t idx;
5314
5315 rsm->r_rtr_cnt++;
5316 rsm->r_dupack = 0;
5317 if (rsm->r_rtr_cnt > BBR_NUM_OF_RETRANS) {
5318 rsm->r_rtr_cnt = BBR_NUM_OF_RETRANS;
5319 rsm->r_flags |= BBR_OVERMAX;
5320 }
5321 if (rsm->r_flags & BBR_RWND_COLLAPSED) {
5322 /* Take off the collapsed flag at rxt */
5323 rsm->r_flags &= ~BBR_RWND_COLLAPSED;
5324 }
5325 if (rsm->r_flags & BBR_MARKED_LOST) {
5326 /* We have retransmitted, its no longer lost */
5327 rsm->r_flags &= ~BBR_MARKED_LOST;
5328 bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
5329 }
5330 if (rsm->r_flags & BBR_RXT_CLEARED) {
5331 /*
5332 * We hit a RXT timer on it and
5333 * we cleared the "acked" flag.
5334 * We now have it going back into
5335 * flight, we can remove the cleared
5336 * flag and possibly do accounting on
5337 * this piece.
5338 */
5339 rsm->r_flags &= ~BBR_RXT_CLEARED;
5340 }
5341 if ((rsm->r_rtr_cnt > 1) && ((rsm->r_flags & BBR_TLP) == 0)) {
5342 bbr->r_ctl.rc_holes_rxt += (rsm->r_end - rsm->r_start);
5343 rsm->r_rtr_bytes += (rsm->r_end - rsm->r_start);
5344 }
5345 idx = rsm->r_rtr_cnt - 1;
5346 rsm->r_tim_lastsent[idx] = cts;
5347 rsm->r_pacing_delay = pacing_time;
5348 rsm->r_delivered = bbr->r_ctl.rc_delivered;
5349 rsm->r_ts_valid = bbr->rc_ts_valid;
5350 if (bbr->rc_ts_valid)
5351 rsm->r_del_ack_ts = bbr->r_ctl.last_inbound_ts;
5352 if (bbr->r_ctl.r_app_limited_until)
5353 rsm->r_app_limited = 1;
5354 else
5355 rsm->r_app_limited = 0;
5356 if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW)
5357 rsm->r_bbr_state = bbr_state_val(bbr);
5358 else
5359 rsm->r_bbr_state = 8;
5360 if (rsm->r_flags & BBR_ACKED) {
5361 /* Problably MTU discovery messing with us */
5362 uint32_t old_flags;
5363
5364 old_flags = rsm->r_flags;
5365 rsm->r_flags &= ~BBR_ACKED;
5366 bbr_log_type_rsmclear(bbr, cts, rsm, old_flags, __LINE__);
5367 bbr->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
5368 if (bbr->r_ctl.rc_sacked == 0)
5369 bbr->r_ctl.rc_sacklast = NULL;
5370 }
5371 if (rsm->r_in_tmap) {
5372 TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
5373 }
5374 TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
5375 rsm->r_in_tmap = 1;
5376 if (rsm->r_flags & BBR_SACK_PASSED) {
5377 /* We have retransmitted due to the SACK pass */
5378 rsm->r_flags &= ~BBR_SACK_PASSED;
5379 rsm->r_flags |= BBR_WAS_SACKPASS;
5380 }
5381 rsm->r_first_sent_time = bbr_get_earliest_send_outstanding(bbr, rsm, cts);
5382 rsm->r_flight_at_send = ctf_flight_size(bbr->rc_tp,
5383 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
5384 bbr->r_ctl.rc_next = TAILQ_NEXT(rsm, r_next);
5385 if (bbr->r_ctl.rc_bbr_hptsi_gain > BBR_UNIT) {
5386 rsm->r_is_gain = 1;
5387 rsm->r_is_drain = 0;
5388 } else if (bbr->r_ctl.rc_bbr_hptsi_gain < BBR_UNIT) {
5389 rsm->r_is_drain = 1;
5390 rsm->r_is_gain = 0;
5391 } else {
5392 rsm->r_is_drain = 0;
5393 rsm->r_is_gain = 0;
5394 }
5395 rsm->r_del_time = bbr->r_ctl.rc_del_time; /* TEMP GOOGLE CODE */
5396 }
5397
5398 /*
5399 * Returns 0, or the sequence where we stopped
5400 * updating. We also update the lenp to be the amount
5401 * of data left.
5402 */
5403
5404 static uint32_t
bbr_update_entry(struct tcpcb * tp,struct tcp_bbr * bbr,struct bbr_sendmap * rsm,uint32_t cts,int32_t * lenp,uint32_t pacing_time)5405 bbr_update_entry(struct tcpcb *tp, struct tcp_bbr *bbr,
5406 struct bbr_sendmap *rsm, uint32_t cts, int32_t *lenp, uint32_t pacing_time)
5407 {
5408 /*
5409 * We (re-)transmitted starting at rsm->r_start for some length
5410 * (possibly less than r_end.
5411 */
5412 struct bbr_sendmap *nrsm;
5413 uint32_t c_end;
5414 int32_t len;
5415
5416 len = *lenp;
5417 c_end = rsm->r_start + len;
5418 if (SEQ_GEQ(c_end, rsm->r_end)) {
5419 /*
5420 * We retransmitted the whole piece or more than the whole
5421 * slopping into the next rsm.
5422 */
5423 bbr_update_rsm(tp, bbr, rsm, cts, pacing_time);
5424 if (c_end == rsm->r_end) {
5425 *lenp = 0;
5426 return (0);
5427 } else {
5428 int32_t act_len;
5429
5430 /* Hangs over the end return whats left */
5431 act_len = rsm->r_end - rsm->r_start;
5432 *lenp = (len - act_len);
5433 return (rsm->r_end);
5434 }
5435 /* We don't get out of this block. */
5436 }
5437 /*
5438 * Here we retransmitted less than the whole thing which means we
5439 * have to split this into what was transmitted and what was not.
5440 */
5441 nrsm = bbr_alloc_full_limit(bbr);
5442 if (nrsm == NULL) {
5443 *lenp = 0;
5444 return (0);
5445 }
5446 /*
5447 * So here we are going to take the original rsm and make it what we
5448 * retransmitted. nrsm will be the tail portion we did not
5449 * retransmit. For example say the chunk was 1, 11 (10 bytes). And
5450 * we retransmitted 5 bytes i.e. 1, 5. The original piece shrinks to
5451 * 1, 6 and the new piece will be 6, 11.
5452 */
5453 bbr_clone_rsm(bbr, nrsm, rsm, c_end);
5454 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
5455 nrsm->r_dupack = 0;
5456 if (rsm->r_in_tmap) {
5457 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
5458 nrsm->r_in_tmap = 1;
5459 }
5460 rsm->r_flags &= (~BBR_HAS_FIN);
5461 bbr_update_rsm(tp, bbr, rsm, cts, pacing_time);
5462 *lenp = 0;
5463 return (0);
5464 }
5465
5466 static uint64_t
bbr_get_hardware_rate(struct tcp_bbr * bbr)5467 bbr_get_hardware_rate(struct tcp_bbr *bbr)
5468 {
5469 uint64_t bw;
5470
5471 bw = bbr_get_bw(bbr);
5472 bw *= (uint64_t)bbr_hptsi_gain[BBR_SUB_GAIN];
5473 bw /= (uint64_t)BBR_UNIT;
5474 return(bw);
5475 }
5476
5477 static void
bbr_setup_less_of_rate(struct tcp_bbr * bbr,uint32_t cts,uint64_t act_rate,uint64_t rate_wanted)5478 bbr_setup_less_of_rate(struct tcp_bbr *bbr, uint32_t cts,
5479 uint64_t act_rate, uint64_t rate_wanted)
5480 {
5481 /*
5482 * We could not get a full gains worth
5483 * of rate.
5484 */
5485 if (get_filter_value(&bbr->r_ctl.rc_delrate) >= act_rate) {
5486 /* we can't even get the real rate */
5487 uint64_t red;
5488
5489 bbr->skip_gain = 1;
5490 bbr->gain_is_limited = 0;
5491 red = get_filter_value(&bbr->r_ctl.rc_delrate) - act_rate;
5492 if (red)
5493 filter_reduce_by(&bbr->r_ctl.rc_delrate, red, cts);
5494 } else {
5495 /* We can use a lower gain */
5496 bbr->skip_gain = 0;
5497 bbr->gain_is_limited = 1;
5498 }
5499 }
5500
5501 static void
bbr_update_hardware_pacing_rate(struct tcp_bbr * bbr,uint32_t cts)5502 bbr_update_hardware_pacing_rate(struct tcp_bbr *bbr, uint32_t cts)
5503 {
5504 const struct tcp_hwrate_limit_table *nrte;
5505 int error, rate = -1;
5506
5507 if (bbr->r_ctl.crte == NULL)
5508 return;
5509 if ((bbr->rc_inp->inp_route.ro_nh == NULL) ||
5510 (bbr->rc_inp->inp_route.ro_nh->nh_ifp == NULL)) {
5511 /* Lost our routes? */
5512 /* Clear the way for a re-attempt */
5513 bbr->bbr_attempt_hdwr_pace = 0;
5514 lost_rate:
5515 bbr->gain_is_limited = 0;
5516 bbr->skip_gain = 0;
5517 bbr->bbr_hdrw_pacing = 0;
5518 counter_u64_add(bbr_flows_whdwr_pacing, -1);
5519 counter_u64_add(bbr_flows_nohdwr_pacing, 1);
5520 tcp_bbr_tso_size_check(bbr, cts);
5521 return;
5522 }
5523 rate = bbr_get_hardware_rate(bbr);
5524 nrte = tcp_chg_pacing_rate(bbr->r_ctl.crte,
5525 bbr->rc_tp,
5526 bbr->rc_inp->inp_route.ro_nh->nh_ifp,
5527 rate,
5528 (RS_PACING_GEQ|RS_PACING_SUB_OK),
5529 &error, NULL);
5530 if (nrte == NULL) {
5531 goto lost_rate;
5532 }
5533 if (nrte != bbr->r_ctl.crte) {
5534 bbr->r_ctl.crte = nrte;
5535 if (error == 0) {
5536 BBR_STAT_INC(bbr_hdwr_rl_mod_ok);
5537 if (bbr->r_ctl.crte->rate < rate) {
5538 /* We have a problem */
5539 bbr_setup_less_of_rate(bbr, cts,
5540 bbr->r_ctl.crte->rate, rate);
5541 } else {
5542 /* We are good */
5543 bbr->gain_is_limited = 0;
5544 bbr->skip_gain = 0;
5545 }
5546 } else {
5547 /* A failure should release the tag */
5548 BBR_STAT_INC(bbr_hdwr_rl_mod_fail);
5549 bbr->gain_is_limited = 0;
5550 bbr->skip_gain = 0;
5551 bbr->bbr_hdrw_pacing = 0;
5552 }
5553 bbr_type_log_hdwr_pacing(bbr,
5554 bbr->r_ctl.crte->ptbl->rs_ifp,
5555 rate,
5556 ((bbr->r_ctl.crte == NULL) ? 0 : bbr->r_ctl.crte->rate),
5557 __LINE__,
5558 cts,
5559 error);
5560 }
5561 }
5562
5563 static void
bbr_adjust_for_hw_pacing(struct tcp_bbr * bbr,uint32_t cts)5564 bbr_adjust_for_hw_pacing(struct tcp_bbr *bbr, uint32_t cts)
5565 {
5566 /*
5567 * If we have hardware pacing support
5568 * we need to factor that in for our
5569 * TSO size.
5570 */
5571 const struct tcp_hwrate_limit_table *rlp;
5572 uint32_t cur_delay, seg_sz, maxseg, new_tso, delta, hdwr_delay;
5573
5574 if ((bbr->bbr_hdrw_pacing == 0) ||
5575 (IN_RECOVERY(bbr->rc_tp->t_flags)) ||
5576 (bbr->r_ctl.crte == NULL))
5577 return;
5578 if (bbr->hw_pacing_set == 0) {
5579 /* Not yet by the hdwr pacing count delay */
5580 return;
5581 }
5582 if (bbr_hdwr_pace_adjust == 0) {
5583 /* No adjustment */
5584 return;
5585 }
5586 rlp = bbr->r_ctl.crte;
5587 if (bbr->rc_tp->t_maxseg > bbr->rc_last_options)
5588 maxseg = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
5589 else
5590 maxseg = BBR_MIN_SEG - bbr->rc_last_options;
5591 /*
5592 * So lets first get the
5593 * time we will take between
5594 * TSO sized sends currently without
5595 * hardware help.
5596 */
5597 cur_delay = bbr_get_pacing_delay(bbr, BBR_UNIT,
5598 bbr->r_ctl.rc_pace_max_segs, cts, 1);
5599 hdwr_delay = bbr->r_ctl.rc_pace_max_segs / maxseg;
5600 hdwr_delay *= rlp->time_between;
5601 if (cur_delay > hdwr_delay)
5602 delta = cur_delay - hdwr_delay;
5603 else
5604 delta = 0;
5605 bbr_log_type_tsosize(bbr, cts, delta, cur_delay, hdwr_delay,
5606 (bbr->r_ctl.rc_pace_max_segs / maxseg),
5607 1);
5608 if (delta &&
5609 (delta < (max(rlp->time_between,
5610 bbr->r_ctl.bbr_hptsi_segments_delay_tar)))) {
5611 /*
5612 * Now lets divide by the pacing
5613 * time between each segment the
5614 * hardware sends rounding up and
5615 * derive a bytes from that. We multiply
5616 * that by bbr_hdwr_pace_adjust to get
5617 * more bang for our buck.
5618 *
5619 * The goal is to have the software pacer
5620 * waiting no more than an additional
5621 * pacing delay if we can (without the
5622 * compensation i.e. x bbr_hdwr_pace_adjust).
5623 */
5624 seg_sz = max(((cur_delay + rlp->time_between)/rlp->time_between),
5625 (bbr->r_ctl.rc_pace_max_segs/maxseg));
5626 seg_sz *= bbr_hdwr_pace_adjust;
5627 if (bbr_hdwr_pace_floor &&
5628 (seg_sz < bbr->r_ctl.crte->ptbl->rs_min_seg)) {
5629 /* Currently hardware paces
5630 * out rs_min_seg segments at a time.
5631 * We need to make sure we always send at least
5632 * a full burst of bbr_hdwr_pace_floor down.
5633 */
5634 seg_sz = bbr->r_ctl.crte->ptbl->rs_min_seg;
5635 }
5636 seg_sz *= maxseg;
5637 } else if (delta == 0) {
5638 /*
5639 * The highest pacing rate is
5640 * above our b/w gained. This means
5641 * we probably are going quite fast at
5642 * the hardware highest rate. Lets just multiply
5643 * the calculated TSO size by the
5644 * multiplier factor (its probably
5645 * 4 segments in the default config for
5646 * mlx).
5647 */
5648 seg_sz = bbr->r_ctl.rc_pace_max_segs * bbr_hdwr_pace_adjust;
5649 if (bbr_hdwr_pace_floor &&
5650 (seg_sz < bbr->r_ctl.crte->ptbl->rs_min_seg)) {
5651 /* Currently hardware paces
5652 * out rs_min_seg segments at a time.
5653 * We need to make sure we always send at least
5654 * a full burst of bbr_hdwr_pace_floor down.
5655 */
5656 seg_sz = bbr->r_ctl.crte->ptbl->rs_min_seg;
5657 }
5658 } else {
5659 /*
5660 * The pacing time difference is so
5661 * big that the hardware will
5662 * pace out more rapidly then we
5663 * really want and then we
5664 * will have a long delay. Lets just keep
5665 * the same TSO size so its as if
5666 * we were not using hdwr pacing (we
5667 * just gain a bit of spacing from the
5668 * hardware if seg_sz > 1).
5669 */
5670 seg_sz = bbr->r_ctl.rc_pace_max_segs;
5671 }
5672 if (seg_sz > bbr->r_ctl.rc_pace_max_segs)
5673 new_tso = seg_sz;
5674 else
5675 new_tso = bbr->r_ctl.rc_pace_max_segs;
5676 if (new_tso >= (PACE_MAX_IP_BYTES-maxseg))
5677 new_tso = PACE_MAX_IP_BYTES - maxseg;
5678
5679 if (new_tso != bbr->r_ctl.rc_pace_max_segs) {
5680 bbr_log_type_tsosize(bbr, cts, new_tso, 0, bbr->r_ctl.rc_pace_max_segs, maxseg, 0);
5681 bbr->r_ctl.rc_pace_max_segs = new_tso;
5682 }
5683 }
5684
5685 static void
tcp_bbr_tso_size_check(struct tcp_bbr * bbr,uint32_t cts)5686 tcp_bbr_tso_size_check(struct tcp_bbr *bbr, uint32_t cts)
5687 {
5688 uint64_t bw;
5689 uint32_t old_tso = 0, new_tso;
5690 uint32_t maxseg, bytes;
5691 uint32_t tls_seg=0;
5692 /*
5693 * Google/linux uses the following algorithm to determine
5694 * the TSO size based on the b/w of the link (from Neal Cardwell email 9/27/18):
5695 *
5696 * bytes = bw_in_bytes_per_second / 1000
5697 * bytes = min(bytes, 64k)
5698 * tso_segs = bytes / MSS
5699 * if (bw < 1.2Mbs)
5700 * min_tso_segs = 1
5701 * else
5702 * min_tso_segs = 2
5703 * tso_segs = max(tso_segs, min_tso_segs)
5704 *
5705 * * Note apply a device specific limit (we apply this in the
5706 * tcp_m_copym).
5707 * Note that before the initial measurement is made google bursts out
5708 * a full iwnd just like new-reno/cubic.
5709 *
5710 * We do not use this algorithm. Instead we
5711 * use a two phased approach:
5712 *
5713 * if ( bw <= per-tcb-cross-over)
5714 * goal_tso = calculate how much with this bw we
5715 * can send in goal-time seconds.
5716 * if (goal_tso > mss)
5717 * seg = goal_tso / mss
5718 * tso = seg * mss
5719 * else
5720 * tso = mss
5721 * if (tso > per-tcb-max)
5722 * tso = per-tcb-max
5723 * else if ( bw > 512Mbps)
5724 * tso = max-tso (64k/mss)
5725 * else
5726 * goal_tso = bw / per-tcb-divsor
5727 * seg = (goal_tso + mss-1)/mss
5728 * tso = seg * mss
5729 *
5730 * if (tso < per-tcb-floor)
5731 * tso = per-tcb-floor
5732 * if (tso > per-tcb-utter_max)
5733 * tso = per-tcb-utter_max
5734 *
5735 * Note the default per-tcb-divisor is 1000 (same as google).
5736 * the goal cross over is 30Mbps however. To recreate googles
5737 * algorithm you need to set:
5738 *
5739 * cross-over = 23,168,000 bps
5740 * goal-time = 18000
5741 * per-tcb-max = 2
5742 * per-tcb-divisor = 1000
5743 * per-tcb-floor = 1
5744 *
5745 * This will get you "google bbr" behavior with respect to tso size.
5746 *
5747 * Note we do set anything TSO size until we are past the initial
5748 * window. Before that we gnerally use either a single MSS
5749 * or we use the full IW size (so we burst a IW at a time)
5750 */
5751
5752 if (bbr->rc_tp->t_maxseg > bbr->rc_last_options) {
5753 maxseg = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
5754 } else {
5755 maxseg = BBR_MIN_SEG - bbr->rc_last_options;
5756 }
5757 old_tso = bbr->r_ctl.rc_pace_max_segs;
5758 if (bbr->rc_past_init_win == 0) {
5759 /*
5760 * Not enough data has been acknowledged to make a
5761 * judgement. Set up the initial TSO based on if we
5762 * are sending a full IW at once or not.
5763 */
5764 if (bbr->rc_use_google)
5765 bbr->r_ctl.rc_pace_max_segs = ((bbr->rc_tp->t_maxseg - bbr->rc_last_options) * 2);
5766 else if (bbr->bbr_init_win_cheat)
5767 bbr->r_ctl.rc_pace_max_segs = bbr_initial_cwnd(bbr, bbr->rc_tp);
5768 else
5769 bbr->r_ctl.rc_pace_max_segs = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
5770 if (bbr->r_ctl.rc_pace_min_segs != bbr->rc_tp->t_maxseg)
5771 bbr->r_ctl.rc_pace_min_segs = bbr->rc_tp->t_maxseg;
5772 if (bbr->r_ctl.rc_pace_max_segs == 0) {
5773 bbr->r_ctl.rc_pace_max_segs = maxseg;
5774 }
5775 bbr_log_type_tsosize(bbr, cts, bbr->r_ctl.rc_pace_max_segs, tls_seg, old_tso, maxseg, 0);
5776 bbr_adjust_for_hw_pacing(bbr, cts);
5777 return;
5778 }
5779 /**
5780 * Now lets set the TSO goal based on our delivery rate in
5781 * bytes per second. Note we only do this if
5782 * we have acked at least the initial cwnd worth of data.
5783 */
5784 bw = bbr_get_bw(bbr);
5785 if (IN_RECOVERY(bbr->rc_tp->t_flags) &&
5786 (bbr->rc_use_google == 0)) {
5787 /* We clamp to one MSS in recovery */
5788 new_tso = maxseg;
5789 } else if (bbr->rc_use_google) {
5790 int min_tso_segs;
5791
5792 /* Google considers the gain too */
5793 if (bbr->r_ctl.rc_bbr_hptsi_gain != BBR_UNIT) {
5794 bw *= bbr->r_ctl.rc_bbr_hptsi_gain;
5795 bw /= BBR_UNIT;
5796 }
5797 bytes = bw / 1024;
5798 if (bytes > (64 * 1024))
5799 bytes = 64 * 1024;
5800 new_tso = bytes / maxseg;
5801 if (bw < ONE_POINT_TWO_MEG)
5802 min_tso_segs = 1;
5803 else
5804 min_tso_segs = 2;
5805 if (new_tso < min_tso_segs)
5806 new_tso = min_tso_segs;
5807 new_tso *= maxseg;
5808 } else if (bbr->rc_no_pacing) {
5809 new_tso = (PACE_MAX_IP_BYTES / maxseg) * maxseg;
5810 } else if (bw <= bbr->r_ctl.bbr_cross_over) {
5811 /*
5812 * Calculate the worse case b/w TSO if we are inserting no
5813 * more than a delay_target number of TSO's.
5814 */
5815 uint32_t tso_len, min_tso;
5816
5817 tso_len = bbr_get_pacing_length(bbr, BBR_UNIT, bbr->r_ctl.bbr_hptsi_segments_delay_tar, bw);
5818 if (tso_len > maxseg) {
5819 new_tso = tso_len / maxseg;
5820 if (new_tso > bbr->r_ctl.bbr_hptsi_segments_max)
5821 new_tso = bbr->r_ctl.bbr_hptsi_segments_max;
5822 new_tso *= maxseg;
5823 } else {
5824 /*
5825 * less than a full sized frame yikes.. long rtt or
5826 * low bw?
5827 */
5828 min_tso = bbr_minseg(bbr);
5829 if ((tso_len > min_tso) && (bbr_all_get_min == 0))
5830 new_tso = rounddown(tso_len, min_tso);
5831 else
5832 new_tso = min_tso;
5833 }
5834 } else if (bw > FIVETWELVE_MBPS) {
5835 /*
5836 * This guy is so fast b/w wise that we can TSO as large as
5837 * possible of segments that the NIC will allow.
5838 */
5839 new_tso = rounddown(PACE_MAX_IP_BYTES, maxseg);
5840 } else {
5841 /*
5842 * This formula is based on attempting to send a segment or
5843 * more every bbr_hptsi_per_second. The default is 1000
5844 * which means you are targeting what you can send every 1ms
5845 * based on the peers bw.
5846 *
5847 * If the number drops to say 500, then you are looking more
5848 * at 2ms and you will raise how much we send in a single
5849 * TSO thus saving CPU (less bbr_output_wtime() calls). The
5850 * trade off of course is you will send more at once and
5851 * thus tend to clump up the sends into larger "bursts"
5852 * building a queue.
5853 */
5854 bw /= bbr->r_ctl.bbr_hptsi_per_second;
5855 new_tso = roundup(bw, (uint64_t)maxseg);
5856 /*
5857 * Gate the floor to match what our lower than 48Mbps
5858 * algorithm does. The ceiling (bbr_hptsi_segments_max) thus
5859 * becomes the floor for this calculation.
5860 */
5861 if (new_tso < (bbr->r_ctl.bbr_hptsi_segments_max * maxseg))
5862 new_tso = (bbr->r_ctl.bbr_hptsi_segments_max * maxseg);
5863 }
5864 if (bbr->r_ctl.bbr_hptsi_segments_floor && (new_tso < (maxseg * bbr->r_ctl.bbr_hptsi_segments_floor)))
5865 new_tso = maxseg * bbr->r_ctl.bbr_hptsi_segments_floor;
5866 if (new_tso > PACE_MAX_IP_BYTES)
5867 new_tso = rounddown(PACE_MAX_IP_BYTES, maxseg);
5868 /* Enforce an utter maximum. */
5869 if (bbr->r_ctl.bbr_utter_max && (new_tso > (bbr->r_ctl.bbr_utter_max * maxseg))) {
5870 new_tso = bbr->r_ctl.bbr_utter_max * maxseg;
5871 }
5872 if (old_tso != new_tso) {
5873 /* Only log changes */
5874 bbr_log_type_tsosize(bbr, cts, new_tso, tls_seg, old_tso, maxseg, 0);
5875 bbr->r_ctl.rc_pace_max_segs = new_tso;
5876 }
5877 /* We have hardware pacing! */
5878 bbr_adjust_for_hw_pacing(bbr, cts);
5879 }
5880
5881 static void
bbr_log_output(struct tcp_bbr * bbr,struct tcpcb * tp,struct tcpopt * to,int32_t len,uint32_t seq_out,uint16_t th_flags,int32_t err,uint32_t cts,struct mbuf * mb,int32_t * abandon,struct bbr_sendmap * hintrsm,uint32_t delay_calc,struct sockbuf * sb)5882 bbr_log_output(struct tcp_bbr *bbr, struct tcpcb *tp, struct tcpopt *to, int32_t len,
5883 uint32_t seq_out, uint16_t th_flags, int32_t err, uint32_t cts,
5884 struct mbuf *mb, int32_t * abandon, struct bbr_sendmap *hintrsm, uint32_t delay_calc,
5885 struct sockbuf *sb)
5886 {
5887
5888 struct bbr_sendmap *rsm, *nrsm;
5889 register uint32_t snd_max, snd_una;
5890 uint32_t pacing_time;
5891 /*
5892 * Add to the RACK log of packets in flight or retransmitted. If
5893 * there is a TS option we will use the TS echoed, if not we will
5894 * grab a TS.
5895 *
5896 * Retransmissions will increment the count and move the ts to its
5897 * proper place. Note that if options do not include TS's then we
5898 * won't be able to effectively use the ACK for an RTT on a retran.
5899 *
5900 * Notes about r_start and r_end. Lets consider a send starting at
5901 * sequence 1 for 10 bytes. In such an example the r_start would be
5902 * 1 (starting sequence) but the r_end would be r_start+len i.e. 11.
5903 * This means that r_end is actually the first sequence for the next
5904 * slot (11).
5905 *
5906 */
5907 INP_WLOCK_ASSERT(tptoinpcb(tp));
5908 if (err) {
5909 /*
5910 * We don't log errors -- we could but snd_max does not
5911 * advance in this case either.
5912 */
5913 return;
5914 }
5915 if (th_flags & TH_RST) {
5916 /*
5917 * We don't log resets and we return immediately from
5918 * sending
5919 */
5920 *abandon = 1;
5921 return;
5922 }
5923 snd_una = tp->snd_una;
5924 if (th_flags & (TH_SYN | TH_FIN) && (hintrsm == NULL)) {
5925 /*
5926 * The call to bbr_log_output is made before bumping
5927 * snd_max. This means we can record one extra byte on a SYN
5928 * or FIN if seq_out is adding more on and a FIN is present
5929 * (and we are not resending).
5930 */
5931 if ((th_flags & TH_SYN) && (tp->iss == seq_out))
5932 len++;
5933 if (th_flags & TH_FIN)
5934 len++;
5935 }
5936 if (SEQ_LEQ((seq_out + len), snd_una)) {
5937 /* Are sending an old segment to induce an ack (keep-alive)? */
5938 return;
5939 }
5940 if (SEQ_LT(seq_out, snd_una)) {
5941 /* huh? should we panic? */
5942 uint32_t end;
5943
5944 end = seq_out + len;
5945 seq_out = snd_una;
5946 len = end - seq_out;
5947 }
5948 snd_max = tp->snd_max;
5949 if (len == 0) {
5950 /* We don't log zero window probes */
5951 return;
5952 }
5953 pacing_time = bbr_get_pacing_delay(bbr, bbr->r_ctl.rc_bbr_hptsi_gain, len, cts, 1);
5954 /* First question is it a retransmission? */
5955 if (seq_out == snd_max) {
5956 again:
5957 rsm = bbr_alloc(bbr);
5958 if (rsm == NULL) {
5959 return;
5960 }
5961 rsm->r_flags = 0;
5962 if (th_flags & TH_SYN)
5963 rsm->r_flags |= BBR_HAS_SYN;
5964 if (th_flags & TH_FIN)
5965 rsm->r_flags |= BBR_HAS_FIN;
5966 rsm->r_tim_lastsent[0] = cts;
5967 rsm->r_rtr_cnt = 1;
5968 rsm->r_rtr_bytes = 0;
5969 rsm->r_start = seq_out;
5970 rsm->r_end = rsm->r_start + len;
5971 rsm->r_dupack = 0;
5972 rsm->r_delivered = bbr->r_ctl.rc_delivered;
5973 rsm->r_pacing_delay = pacing_time;
5974 rsm->r_ts_valid = bbr->rc_ts_valid;
5975 if (bbr->rc_ts_valid)
5976 rsm->r_del_ack_ts = bbr->r_ctl.last_inbound_ts;
5977 rsm->r_del_time = bbr->r_ctl.rc_del_time;
5978 if (bbr->r_ctl.r_app_limited_until)
5979 rsm->r_app_limited = 1;
5980 else
5981 rsm->r_app_limited = 0;
5982 rsm->r_first_sent_time = bbr_get_earliest_send_outstanding(bbr, rsm, cts);
5983 rsm->r_flight_at_send = ctf_flight_size(bbr->rc_tp,
5984 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
5985 /*
5986 * Here we must also add in this rsm since snd_max
5987 * is updated after we return from a new send.
5988 */
5989 rsm->r_flight_at_send += len;
5990 TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_map, rsm, r_next);
5991 TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
5992 rsm->r_in_tmap = 1;
5993 if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW)
5994 rsm->r_bbr_state = bbr_state_val(bbr);
5995 else
5996 rsm->r_bbr_state = 8;
5997 if (bbr->r_ctl.rc_bbr_hptsi_gain > BBR_UNIT) {
5998 rsm->r_is_gain = 1;
5999 rsm->r_is_drain = 0;
6000 } else if (bbr->r_ctl.rc_bbr_hptsi_gain < BBR_UNIT) {
6001 rsm->r_is_drain = 1;
6002 rsm->r_is_gain = 0;
6003 } else {
6004 rsm->r_is_drain = 0;
6005 rsm->r_is_gain = 0;
6006 }
6007 return;
6008 }
6009 /*
6010 * If we reach here its a retransmission and we need to find it.
6011 */
6012 more:
6013 if (hintrsm && (hintrsm->r_start == seq_out)) {
6014 rsm = hintrsm;
6015 hintrsm = NULL;
6016 } else if (bbr->r_ctl.rc_next) {
6017 /* We have a hint from a previous run */
6018 rsm = bbr->r_ctl.rc_next;
6019 } else {
6020 /* No hints sorry */
6021 rsm = NULL;
6022 }
6023 if ((rsm) && (rsm->r_start == seq_out)) {
6024 /*
6025 * We used rc_next or hintrsm to retransmit, hopefully the
6026 * likely case.
6027 */
6028 seq_out = bbr_update_entry(tp, bbr, rsm, cts, &len, pacing_time);
6029 if (len == 0) {
6030 return;
6031 } else {
6032 goto more;
6033 }
6034 }
6035 /* Ok it was not the last pointer go through it the hard way. */
6036 TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_map, r_next) {
6037 if (rsm->r_start == seq_out) {
6038 seq_out = bbr_update_entry(tp, bbr, rsm, cts, &len, pacing_time);
6039 bbr->r_ctl.rc_next = TAILQ_NEXT(rsm, r_next);
6040 if (len == 0) {
6041 return;
6042 } else {
6043 continue;
6044 }
6045 }
6046 if (SEQ_GEQ(seq_out, rsm->r_start) && SEQ_LT(seq_out, rsm->r_end)) {
6047 /* Transmitted within this piece */
6048 /*
6049 * Ok we must split off the front and then let the
6050 * update do the rest
6051 */
6052 nrsm = bbr_alloc_full_limit(bbr);
6053 if (nrsm == NULL) {
6054 bbr_update_rsm(tp, bbr, rsm, cts, pacing_time);
6055 return;
6056 }
6057 /*
6058 * copy rsm to nrsm and then trim the front of rsm
6059 * to not include this part.
6060 */
6061 bbr_clone_rsm(bbr, nrsm, rsm, seq_out);
6062 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
6063 if (rsm->r_in_tmap) {
6064 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
6065 nrsm->r_in_tmap = 1;
6066 }
6067 rsm->r_flags &= (~BBR_HAS_FIN);
6068 seq_out = bbr_update_entry(tp, bbr, nrsm, cts, &len, pacing_time);
6069 if (len == 0) {
6070 return;
6071 }
6072 }
6073 }
6074 /*
6075 * Hmm not found in map did they retransmit both old and on into the
6076 * new?
6077 */
6078 if (seq_out == tp->snd_max) {
6079 goto again;
6080 } else if (SEQ_LT(seq_out, tp->snd_max)) {
6081 #ifdef BBR_INVARIANTS
6082 printf("seq_out:%u len:%d snd_una:%u snd_max:%u -- but rsm not found?\n",
6083 seq_out, len, tp->snd_una, tp->snd_max);
6084 printf("Starting Dump of all rack entries\n");
6085 TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_map, r_next) {
6086 printf("rsm:%p start:%u end:%u\n",
6087 rsm, rsm->r_start, rsm->r_end);
6088 }
6089 printf("Dump complete\n");
6090 panic("seq_out not found rack:%p tp:%p",
6091 bbr, tp);
6092 #endif
6093 } else {
6094 #ifdef BBR_INVARIANTS
6095 /*
6096 * Hmm beyond sndmax? (only if we are using the new rtt-pack
6097 * flag)
6098 */
6099 panic("seq_out:%u(%d) is beyond snd_max:%u tp:%p",
6100 seq_out, len, tp->snd_max, tp);
6101 #endif
6102 }
6103 }
6104
6105 static void
bbr_collapse_rtt(struct tcpcb * tp,struct tcp_bbr * bbr,int32_t rtt)6106 bbr_collapse_rtt(struct tcpcb *tp, struct tcp_bbr *bbr, int32_t rtt)
6107 {
6108 /*
6109 * Collapse timeout back the cum-ack moved.
6110 */
6111 tp->t_rxtshift = 0;
6112 tp->t_softerror = 0;
6113 }
6114
6115 static void
tcp_bbr_xmit_timer(struct tcp_bbr * bbr,uint32_t rtt_usecs,uint32_t rsm_send_time,uint32_t r_start,uint32_t tsin)6116 tcp_bbr_xmit_timer(struct tcp_bbr *bbr, uint32_t rtt_usecs, uint32_t rsm_send_time, uint32_t r_start, uint32_t tsin)
6117 {
6118 bbr->rtt_valid = 1;
6119 bbr->r_ctl.cur_rtt = rtt_usecs;
6120 bbr->r_ctl.ts_in = tsin;
6121 if (rsm_send_time)
6122 bbr->r_ctl.cur_rtt_send_time = rsm_send_time;
6123 }
6124
6125 static void
bbr_make_timestamp_determination(struct tcp_bbr * bbr)6126 bbr_make_timestamp_determination(struct tcp_bbr *bbr)
6127 {
6128 /**
6129 * We have in our bbr control:
6130 * 1) The timestamp we started observing cum-acks (bbr->r_ctl.bbr_ts_check_tstmp).
6131 * 2) Our timestamp indicating when we sent that packet (bbr->r_ctl.rsm->bbr_ts_check_our_cts).
6132 * 3) The current timestamp that just came in (bbr->r_ctl.last_inbound_ts)
6133 * 4) The time that the packet that generated that ack was sent (bbr->r_ctl.cur_rtt_send_time)
6134 *
6135 * Now we can calculate the time between the sends by doing:
6136 *
6137 * delta = bbr->r_ctl.cur_rtt_send_time - bbr->r_ctl.bbr_ts_check_our_cts
6138 *
6139 * And the peer's time between receiving them by doing:
6140 *
6141 * peer_delta = bbr->r_ctl.last_inbound_ts - bbr->r_ctl.bbr_ts_check_tstmp
6142 *
6143 * We want to figure out if the timestamp values are in msec, 10msec or usec.
6144 * We also may find that we can't use the timestamps if say we see
6145 * that the peer_delta indicates that though we may have taken 10ms to
6146 * pace out the data, it only saw 1ms between the two packets. This would
6147 * indicate that somewhere on the path is a batching entity that is giving
6148 * out time-slices of the actual b/w. This would mean we could not use
6149 * reliably the peers timestamps.
6150 *
6151 * We expect delta > peer_delta initially. Until we figure out the
6152 * timestamp difference which we will store in bbr->r_ctl.bbr_peer_tsratio.
6153 * If we place 1000 there then its a ms vs our usec. If we place 10000 there
6154 * then its 10ms vs our usec. If the peer is running a usec clock we would
6155 * put a 1 there. If the value is faster then ours, we will disable the
6156 * use of timestamps (though we could revist this later if we find it to be not
6157 * just an isolated one or two flows)).
6158 *
6159 * To detect the batching middle boxes we will come up with our compensation and
6160 * if with it in place, we find the peer is drastically off (by some margin) in
6161 * the smaller direction, then we will assume the worst case and disable use of timestamps.
6162 *
6163 */
6164 uint64_t delta, peer_delta, delta_up;
6165
6166 delta = bbr->r_ctl.cur_rtt_send_time - bbr->r_ctl.bbr_ts_check_our_cts;
6167 if (delta < bbr_min_usec_delta) {
6168 /*
6169 * Have not seen a min amount of time
6170 * between our send times so we can
6171 * make a determination of the timestamp
6172 * yet.
6173 */
6174 return;
6175 }
6176 peer_delta = bbr->r_ctl.last_inbound_ts - bbr->r_ctl.bbr_ts_check_tstmp;
6177 if (peer_delta < bbr_min_peer_delta) {
6178 /*
6179 * We may have enough in the form of
6180 * our delta but the peers number
6181 * has not changed that much. It could
6182 * be its clock ratio is such that
6183 * we need more data (10ms tick) or
6184 * there may be other compression scenarios
6185 * going on. In any event we need the
6186 * spread to be larger.
6187 */
6188 return;
6189 }
6190 /* Ok lets first see which way our delta is going */
6191 if (peer_delta > delta) {
6192 /* Very unlikely, the peer without
6193 * compensation shows that it saw
6194 * the two sends arrive further apart
6195 * then we saw then in micro-seconds.
6196 */
6197 if (peer_delta < (delta + ((delta * (uint64_t)1000)/ (uint64_t)bbr_delta_percent))) {
6198 /* well it looks like the peer is a micro-second clock. */
6199 bbr->rc_ts_clock_set = 1;
6200 bbr->r_ctl.bbr_peer_tsratio = 1;
6201 } else {
6202 bbr->rc_ts_cant_be_used = 1;
6203 bbr->rc_ts_clock_set = 1;
6204 }
6205 return;
6206 }
6207 /* Ok we know that the peer_delta is smaller than our send distance */
6208 bbr->rc_ts_clock_set = 1;
6209 /* First question is it within the percentage that they are using usec time? */
6210 delta_up = (peer_delta * 1000) / (uint64_t)bbr_delta_percent;
6211 if ((peer_delta + delta_up) >= delta) {
6212 /* Its a usec clock */
6213 bbr->r_ctl.bbr_peer_tsratio = 1;
6214 bbr_log_tstmp_validation(bbr, peer_delta, delta);
6215 return;
6216 }
6217 /* Ok if not usec, what about 10usec (though unlikely)? */
6218 delta_up = (peer_delta * 1000 * 10) / (uint64_t)bbr_delta_percent;
6219 if (((peer_delta * 10) + delta_up) >= delta) {
6220 bbr->r_ctl.bbr_peer_tsratio = 10;
6221 bbr_log_tstmp_validation(bbr, peer_delta, delta);
6222 return;
6223 }
6224 /* And what about 100usec (though again unlikely)? */
6225 delta_up = (peer_delta * 1000 * 100) / (uint64_t)bbr_delta_percent;
6226 if (((peer_delta * 100) + delta_up) >= delta) {
6227 bbr->r_ctl.bbr_peer_tsratio = 100;
6228 bbr_log_tstmp_validation(bbr, peer_delta, delta);
6229 return;
6230 }
6231 /* And how about 1 msec (the most likely one)? */
6232 delta_up = (peer_delta * 1000 * 1000) / (uint64_t)bbr_delta_percent;
6233 if (((peer_delta * 1000) + delta_up) >= delta) {
6234 bbr->r_ctl.bbr_peer_tsratio = 1000;
6235 bbr_log_tstmp_validation(bbr, peer_delta, delta);
6236 return;
6237 }
6238 /* Ok if not msec could it be 10 msec? */
6239 delta_up = (peer_delta * 1000 * 10000) / (uint64_t)bbr_delta_percent;
6240 if (((peer_delta * 10000) + delta_up) >= delta) {
6241 bbr->r_ctl.bbr_peer_tsratio = 10000;
6242 return;
6243 }
6244 /* If we fall down here the clock tick so slowly we can't use it */
6245 bbr->rc_ts_cant_be_used = 1;
6246 bbr->r_ctl.bbr_peer_tsratio = 0;
6247 bbr_log_tstmp_validation(bbr, peer_delta, delta);
6248 }
6249
6250 /*
6251 * Collect new round-trip time estimate
6252 * and update averages and current timeout.
6253 */
6254 static void
tcp_bbr_xmit_timer_commit(struct tcp_bbr * bbr,struct tcpcb * tp,uint32_t cts)6255 tcp_bbr_xmit_timer_commit(struct tcp_bbr *bbr, struct tcpcb *tp, uint32_t cts)
6256 {
6257 int32_t delta;
6258 uint32_t rtt, tsin;
6259 int32_t rtt_ticks;
6260
6261 if (bbr->rtt_valid == 0)
6262 /* No valid sample */
6263 return;
6264
6265 rtt = bbr->r_ctl.cur_rtt;
6266 tsin = bbr->r_ctl.ts_in;
6267 if (bbr->rc_prtt_set_ts) {
6268 /*
6269 * We are to force feed the rttProp filter due
6270 * to an entry into PROBE_RTT. This assures
6271 * that the times are sync'd between when we
6272 * go into PROBE_RTT and the filter expiration.
6273 *
6274 * Google does not use a true filter, so they do
6275 * this implicitly since they only keep one value
6276 * and when they enter probe-rtt they update the
6277 * value to the newest rtt.
6278 */
6279 uint32_t rtt_prop;
6280
6281 bbr->rc_prtt_set_ts = 0;
6282 rtt_prop = get_filter_value_small(&bbr->r_ctl.rc_rttprop);
6283 if (rtt > rtt_prop)
6284 filter_increase_by_small(&bbr->r_ctl.rc_rttprop, (rtt - rtt_prop), cts);
6285 else
6286 apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, cts);
6287 }
6288 #ifdef STATS
6289 stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_PATHRTT, imax(0, rtt));
6290 #endif
6291 if (bbr->rc_ack_was_delayed)
6292 rtt += bbr->r_ctl.rc_ack_hdwr_delay;
6293
6294 if (rtt < bbr->r_ctl.rc_lowest_rtt)
6295 bbr->r_ctl.rc_lowest_rtt = rtt;
6296 bbr_log_rtt_sample(bbr, rtt, tsin);
6297 if (bbr->r_init_rtt) {
6298 /*
6299 * The initial rtt is not-trusted, nuke it and lets get
6300 * our first valid measurement in.
6301 */
6302 bbr->r_init_rtt = 0;
6303 tp->t_srtt = 0;
6304 }
6305 if ((bbr->rc_ts_clock_set == 0) && bbr->rc_ts_valid) {
6306 /*
6307 * So we have not yet figured out
6308 * what the peers TSTMP value is
6309 * in (most likely ms). We need a
6310 * series of cum-ack's to determine
6311 * this reliably.
6312 */
6313 if (bbr->rc_ack_is_cumack) {
6314 if (bbr->rc_ts_data_set) {
6315 /* Lets attempt to determine the timestamp granularity. */
6316 bbr_make_timestamp_determination(bbr);
6317 } else {
6318 bbr->rc_ts_data_set = 1;
6319 bbr->r_ctl.bbr_ts_check_tstmp = bbr->r_ctl.last_inbound_ts;
6320 bbr->r_ctl.bbr_ts_check_our_cts = bbr->r_ctl.cur_rtt_send_time;
6321 }
6322 } else {
6323 /*
6324 * We have to have consecutive acks
6325 * reset any "filled" state to none.
6326 */
6327 bbr->rc_ts_data_set = 0;
6328 }
6329 }
6330 /* Round it up */
6331 rtt_ticks = USEC_2_TICKS((rtt + (USECS_IN_MSEC - 1)));
6332 if (rtt_ticks == 0)
6333 rtt_ticks = 1;
6334 if (tp->t_srtt != 0) {
6335 /*
6336 * srtt is stored as fixed point with 5 bits after the
6337 * binary point (i.e., scaled by 8). The following magic is
6338 * equivalent to the smoothing algorithm in rfc793 with an
6339 * alpha of .875 (srtt = rtt/8 + srtt*7/8 in fixed point).
6340 * Adjust rtt to origin 0.
6341 */
6342
6343 delta = ((rtt_ticks - 1) << TCP_DELTA_SHIFT)
6344 - (tp->t_srtt >> (TCP_RTT_SHIFT - TCP_DELTA_SHIFT));
6345
6346 tp->t_srtt += delta;
6347 if (tp->t_srtt <= 0)
6348 tp->t_srtt = 1;
6349
6350 /*
6351 * We accumulate a smoothed rtt variance (actually, a
6352 * smoothed mean difference), then set the retransmit timer
6353 * to smoothed rtt + 4 times the smoothed variance. rttvar
6354 * is stored as fixed point with 4 bits after the binary
6355 * point (scaled by 16). The following is equivalent to
6356 * rfc793 smoothing with an alpha of .75 (rttvar =
6357 * rttvar*3/4 + |delta| / 4). This replaces rfc793's
6358 * wired-in beta.
6359 */
6360 if (delta < 0)
6361 delta = -delta;
6362 delta -= tp->t_rttvar >> (TCP_RTTVAR_SHIFT - TCP_DELTA_SHIFT);
6363 tp->t_rttvar += delta;
6364 if (tp->t_rttvar <= 0)
6365 tp->t_rttvar = 1;
6366 } else {
6367 /*
6368 * No rtt measurement yet - use the unsmoothed rtt. Set the
6369 * variance to half the rtt (so our first retransmit happens
6370 * at 3*rtt).
6371 */
6372 tp->t_srtt = rtt_ticks << TCP_RTT_SHIFT;
6373 tp->t_rttvar = rtt_ticks << (TCP_RTTVAR_SHIFT - 1);
6374 }
6375 KMOD_TCPSTAT_INC(tcps_rttupdated);
6376 if (tp->t_rttupdated < UCHAR_MAX)
6377 tp->t_rttupdated++;
6378 #ifdef STATS
6379 stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RTT, imax(0, rtt_ticks));
6380 #endif
6381 /*
6382 * the retransmit should happen at rtt + 4 * rttvar. Because of the
6383 * way we do the smoothing, srtt and rttvar will each average +1/2
6384 * tick of bias. When we compute the retransmit timer, we want 1/2
6385 * tick of rounding and 1 extra tick because of +-1/2 tick
6386 * uncertainty in the firing of the timer. The bias will give us
6387 * exactly the 1.5 tick we need. But, because the bias is
6388 * statistical, we have to test that we don't drop below the minimum
6389 * feasible timer (which is 2 ticks).
6390 */
6391 TCPT_RANGESET(tp->t_rxtcur, TCP_REXMTVAL(tp),
6392 max(MSEC_2_TICKS(bbr->r_ctl.rc_min_rto_ms), rtt_ticks + 2),
6393 MSEC_2_TICKS(((uint32_t)bbr->rc_max_rto_sec) * 1000));
6394
6395 /*
6396 * We received an ack for a packet that wasn't retransmitted; it is
6397 * probably safe to discard any error indications we've received
6398 * recently. This isn't quite right, but close enough for now (a
6399 * route might have failed after we sent a segment, and the return
6400 * path might not be symmetrical).
6401 */
6402 tp->t_softerror = 0;
6403 rtt = (TICKS_2_USEC(bbr->rc_tp->t_srtt) >> TCP_RTT_SHIFT);
6404 if (bbr->r_ctl.bbr_smallest_srtt_this_state > rtt)
6405 bbr->r_ctl.bbr_smallest_srtt_this_state = rtt;
6406 }
6407
6408 static void
bbr_set_reduced_rtt(struct tcp_bbr * bbr,uint32_t cts,uint32_t line)6409 bbr_set_reduced_rtt(struct tcp_bbr *bbr, uint32_t cts, uint32_t line)
6410 {
6411 bbr->r_ctl.rc_rtt_shrinks = cts;
6412 if (bbr_can_force_probertt &&
6413 (TSTMP_GT(cts, bbr->r_ctl.last_in_probertt)) &&
6414 ((cts - bbr->r_ctl.last_in_probertt) > bbr->r_ctl.rc_probertt_int)) {
6415 /*
6416 * We should enter probe-rtt its been too long
6417 * since we have been there.
6418 */
6419 bbr_enter_probe_rtt(bbr, cts, __LINE__);
6420 } else
6421 bbr_check_probe_rtt_limits(bbr, cts);
6422 }
6423
6424 static void
tcp_bbr_commit_bw(struct tcp_bbr * bbr,uint32_t cts)6425 tcp_bbr_commit_bw(struct tcp_bbr *bbr, uint32_t cts)
6426 {
6427 uint64_t orig_bw;
6428
6429 if (bbr->r_ctl.rc_bbr_cur_del_rate == 0) {
6430 /* We never apply a zero measurement */
6431 bbr_log_type_bbrupd(bbr, 20, cts, 0, 0,
6432 0, 0, 0, 0, 0, 0);
6433 return;
6434 }
6435 if (bbr->r_ctl.r_measurement_count < 0xffffffff)
6436 bbr->r_ctl.r_measurement_count++;
6437 orig_bw = get_filter_value(&bbr->r_ctl.rc_delrate);
6438 apply_filter_max(&bbr->r_ctl.rc_delrate, bbr->r_ctl.rc_bbr_cur_del_rate, bbr->r_ctl.rc_pkt_epoch);
6439 bbr_log_type_bbrupd(bbr, 21, cts, (uint32_t)orig_bw,
6440 (uint32_t)get_filter_value(&bbr->r_ctl.rc_delrate),
6441 0, 0, 0, 0, 0, 0);
6442 if (orig_bw &&
6443 (orig_bw != get_filter_value(&bbr->r_ctl.rc_delrate))) {
6444 if (bbr->bbr_hdrw_pacing) {
6445 /*
6446 * Apply a new rate to the hardware
6447 * possibly.
6448 */
6449 bbr_update_hardware_pacing_rate(bbr, cts);
6450 }
6451 bbr_set_state_target(bbr, __LINE__);
6452 tcp_bbr_tso_size_check(bbr, cts);
6453 if (bbr->r_recovery_bw) {
6454 bbr_setup_red_bw(bbr, cts);
6455 bbr_log_type_bw_reduce(bbr, BBR_RED_BW_USELRBW);
6456 }
6457 } else if ((orig_bw == 0) && get_filter_value(&bbr->r_ctl.rc_delrate))
6458 tcp_bbr_tso_size_check(bbr, cts);
6459 }
6460
6461 static void
bbr_nf_measurement(struct tcp_bbr * bbr,struct bbr_sendmap * rsm,uint32_t rtt,uint32_t cts)6462 bbr_nf_measurement(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, uint32_t rtt, uint32_t cts)
6463 {
6464 if (bbr->rc_in_persist == 0) {
6465 /* We log only when not in persist */
6466 /* Translate to a Bytes Per Second */
6467 uint64_t tim, bw, ts_diff, ts_bw;
6468 uint32_t delivered;
6469
6470 if (TSTMP_GT(bbr->r_ctl.rc_del_time, rsm->r_del_time))
6471 tim = (uint64_t)(bbr->r_ctl.rc_del_time - rsm->r_del_time);
6472 else
6473 tim = 1;
6474 /*
6475 * Now that we have processed the tim (skipping the sample
6476 * or possibly updating the time, go ahead and
6477 * calculate the cdr.
6478 */
6479 delivered = (bbr->r_ctl.rc_delivered - rsm->r_delivered);
6480 bw = (uint64_t)delivered;
6481 bw *= (uint64_t)USECS_IN_SECOND;
6482 bw /= tim;
6483 if (bw == 0) {
6484 /* We must have a calculatable amount */
6485 return;
6486 }
6487 /*
6488 * If we are using this b/w shove it in now so we
6489 * can see in the trace viewer if it gets over-ridden.
6490 */
6491 if (rsm->r_ts_valid &&
6492 bbr->rc_ts_valid &&
6493 bbr->rc_ts_clock_set &&
6494 (bbr->rc_ts_cant_be_used == 0) &&
6495 bbr->rc_use_ts_limit) {
6496 ts_diff = max((bbr->r_ctl.last_inbound_ts - rsm->r_del_ack_ts), 1);
6497 ts_diff *= bbr->r_ctl.bbr_peer_tsratio;
6498 if ((delivered == 0) ||
6499 (rtt < 1000)) {
6500 /* Can't use the ts */
6501 bbr_log_type_bbrupd(bbr, 61, cts,
6502 ts_diff,
6503 bbr->r_ctl.last_inbound_ts,
6504 rsm->r_del_ack_ts, 0,
6505 0, 0, 0, delivered);
6506 } else {
6507 ts_bw = (uint64_t)delivered;
6508 ts_bw *= (uint64_t)USECS_IN_SECOND;
6509 ts_bw /= ts_diff;
6510 bbr_log_type_bbrupd(bbr, 62, cts,
6511 (ts_bw >> 32),
6512 (ts_bw & 0xffffffff), 0, 0,
6513 0, 0, ts_diff, delivered);
6514 if ((bbr->ts_can_raise) &&
6515 (ts_bw > bw)) {
6516 bbr_log_type_bbrupd(bbr, 8, cts,
6517 delivered,
6518 ts_diff,
6519 (bw >> 32),
6520 (bw & 0x00000000ffffffff),
6521 0, 0, 0, 0);
6522 bw = ts_bw;
6523 } else if (ts_bw && (ts_bw < bw)) {
6524 bbr_log_type_bbrupd(bbr, 7, cts,
6525 delivered,
6526 ts_diff,
6527 (bw >> 32),
6528 (bw & 0x00000000ffffffff),
6529 0, 0, 0, 0);
6530 bw = ts_bw;
6531 }
6532 }
6533 }
6534 if (rsm->r_first_sent_time &&
6535 TSTMP_GT(rsm->r_tim_lastsent[(rsm->r_rtr_cnt -1)],rsm->r_first_sent_time)) {
6536 uint64_t sbw, sti;
6537 /*
6538 * We use what was in flight at the time of our
6539 * send and the size of this send to figure
6540 * out what we have been sending at (amount).
6541 * For the time we take from the time of
6542 * the send of the first send outstanding
6543 * until this send plus this sends pacing
6544 * time. This gives us a good calculation
6545 * as to the rate we have been sending at.
6546 */
6547
6548 sbw = (uint64_t)(rsm->r_flight_at_send);
6549 sbw *= (uint64_t)USECS_IN_SECOND;
6550 sti = rsm->r_tim_lastsent[(rsm->r_rtr_cnt -1)] - rsm->r_first_sent_time;
6551 sti += rsm->r_pacing_delay;
6552 sbw /= sti;
6553 if (sbw < bw) {
6554 bbr_log_type_bbrupd(bbr, 6, cts,
6555 delivered,
6556 (uint32_t)sti,
6557 (bw >> 32),
6558 (uint32_t)bw,
6559 rsm->r_first_sent_time, 0, (sbw >> 32),
6560 (uint32_t)sbw);
6561 bw = sbw;
6562 }
6563 }
6564 /* Use the google algorithm for b/w measurements */
6565 bbr->r_ctl.rc_bbr_cur_del_rate = bw;
6566 if ((rsm->r_app_limited == 0) ||
6567 (bw > get_filter_value(&bbr->r_ctl.rc_delrate))) {
6568 tcp_bbr_commit_bw(bbr, cts);
6569 bbr_log_type_bbrupd(bbr, 10, cts, (uint32_t)tim, delivered,
6570 0, 0, 0, 0, bbr->r_ctl.rc_del_time, rsm->r_del_time);
6571 }
6572 }
6573 }
6574
6575 static void
bbr_google_measurement(struct tcp_bbr * bbr,struct bbr_sendmap * rsm,uint32_t rtt,uint32_t cts)6576 bbr_google_measurement(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, uint32_t rtt, uint32_t cts)
6577 {
6578 if (bbr->rc_in_persist == 0) {
6579 /* We log only when not in persist */
6580 /* Translate to a Bytes Per Second */
6581 uint64_t tim, bw;
6582 uint32_t delivered;
6583 int no_apply = 0;
6584
6585 if (TSTMP_GT(bbr->r_ctl.rc_del_time, rsm->r_del_time))
6586 tim = (uint64_t)(bbr->r_ctl.rc_del_time - rsm->r_del_time);
6587 else
6588 tim = 1;
6589 /*
6590 * Now that we have processed the tim (skipping the sample
6591 * or possibly updating the time, go ahead and
6592 * calculate the cdr.
6593 */
6594 delivered = (bbr->r_ctl.rc_delivered - rsm->r_delivered);
6595 bw = (uint64_t)delivered;
6596 bw *= (uint64_t)USECS_IN_SECOND;
6597 bw /= tim;
6598 if (tim < bbr->r_ctl.rc_lowest_rtt) {
6599 bbr_log_type_bbrupd(bbr, 99, cts, (uint32_t)tim, delivered,
6600 tim, bbr->r_ctl.rc_lowest_rtt, 0, 0, 0, 0);
6601
6602 no_apply = 1;
6603 }
6604 /*
6605 * If we are using this b/w shove it in now so we
6606 * can see in the trace viewer if it gets over-ridden.
6607 */
6608 bbr->r_ctl.rc_bbr_cur_del_rate = bw;
6609 /* Gate by the sending rate */
6610 if (rsm->r_first_sent_time &&
6611 TSTMP_GT(rsm->r_tim_lastsent[(rsm->r_rtr_cnt -1)],rsm->r_first_sent_time)) {
6612 uint64_t sbw, sti;
6613 /*
6614 * We use what was in flight at the time of our
6615 * send and the size of this send to figure
6616 * out what we have been sending at (amount).
6617 * For the time we take from the time of
6618 * the send of the first send outstanding
6619 * until this send plus this sends pacing
6620 * time. This gives us a good calculation
6621 * as to the rate we have been sending at.
6622 */
6623
6624 sbw = (uint64_t)(rsm->r_flight_at_send);
6625 sbw *= (uint64_t)USECS_IN_SECOND;
6626 sti = rsm->r_tim_lastsent[(rsm->r_rtr_cnt -1)] - rsm->r_first_sent_time;
6627 sti += rsm->r_pacing_delay;
6628 sbw /= sti;
6629 if (sbw < bw) {
6630 bbr_log_type_bbrupd(bbr, 6, cts,
6631 delivered,
6632 (uint32_t)sti,
6633 (bw >> 32),
6634 (uint32_t)bw,
6635 rsm->r_first_sent_time, 0, (sbw >> 32),
6636 (uint32_t)sbw);
6637 bw = sbw;
6638 }
6639 if ((sti > tim) &&
6640 (sti < bbr->r_ctl.rc_lowest_rtt)) {
6641 bbr_log_type_bbrupd(bbr, 99, cts, (uint32_t)tim, delivered,
6642 (uint32_t)sti, bbr->r_ctl.rc_lowest_rtt, 0, 0, 0, 0);
6643 no_apply = 1;
6644 } else
6645 no_apply = 0;
6646 }
6647 bbr->r_ctl.rc_bbr_cur_del_rate = bw;
6648 if ((no_apply == 0) &&
6649 ((rsm->r_app_limited == 0) ||
6650 (bw > get_filter_value(&bbr->r_ctl.rc_delrate)))) {
6651 tcp_bbr_commit_bw(bbr, cts);
6652 bbr_log_type_bbrupd(bbr, 10, cts, (uint32_t)tim, delivered,
6653 0, 0, 0, 0, bbr->r_ctl.rc_del_time, rsm->r_del_time);
6654 }
6655 }
6656 }
6657
6658 static void
bbr_update_bbr_info(struct tcp_bbr * bbr,struct bbr_sendmap * rsm,uint32_t rtt,uint32_t cts,uint32_t tsin,uint32_t uts,int32_t match,uint32_t rsm_send_time,int32_t ack_type,struct tcpopt * to)6659 bbr_update_bbr_info(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, uint32_t rtt, uint32_t cts, uint32_t tsin,
6660 uint32_t uts, int32_t match, uint32_t rsm_send_time, int32_t ack_type, struct tcpopt *to)
6661 {
6662 uint64_t old_rttprop;
6663
6664 /* Update our delivery time and amount */
6665 bbr->r_ctl.rc_delivered += (rsm->r_end - rsm->r_start);
6666 bbr->r_ctl.rc_del_time = cts;
6667 if (rtt == 0) {
6668 /*
6669 * 0 means its a retransmit, for now we don't use these for
6670 * the rest of BBR.
6671 */
6672 return;
6673 }
6674 if ((bbr->rc_use_google == 0) &&
6675 (match != BBR_RTT_BY_EXACTMATCH) &&
6676 (match != BBR_RTT_BY_TIMESTAMP)){
6677 /*
6678 * We get a lot of rtt updates, lets not pay attention to
6679 * any that are not an exact match. That way we don't have
6680 * to worry about timestamps and the whole nonsense of
6681 * unsure if its a retransmission etc (if we ever had the
6682 * timestamp fixed to always have the last thing sent this
6683 * would not be a issue).
6684 */
6685 return;
6686 }
6687 if ((bbr_no_retran && bbr->rc_use_google) &&
6688 (match != BBR_RTT_BY_EXACTMATCH) &&
6689 (match != BBR_RTT_BY_TIMESTAMP)){
6690 /*
6691 * We only do measurements in google mode
6692 * with bbr_no_retran on for sure things.
6693 */
6694 return;
6695 }
6696 /* Only update srtt if we know by exact match */
6697 tcp_bbr_xmit_timer(bbr, rtt, rsm_send_time, rsm->r_start, tsin);
6698 if (ack_type == BBR_CUM_ACKED)
6699 bbr->rc_ack_is_cumack = 1;
6700 else
6701 bbr->rc_ack_is_cumack = 0;
6702 old_rttprop = bbr_get_rtt(bbr, BBR_RTT_PROP);
6703 /*
6704 * Note the following code differs to the original
6705 * BBR spec. It calls for <= not <. However after a
6706 * long discussion in email with Neal, he acknowledged
6707 * that it should be < than so that we will have flows
6708 * going into probe-rtt (we were seeing cases where that
6709 * did not happen and caused ugly things to occur). We
6710 * have added this agreed upon fix to our code base.
6711 */
6712 if (rtt < old_rttprop) {
6713 /* Update when we last saw a rtt drop */
6714 bbr_log_rtt_shrinks(bbr, cts, 0, rtt, __LINE__, BBR_RTTS_NEWRTT, 0);
6715 bbr_set_reduced_rtt(bbr, cts, __LINE__);
6716 }
6717 bbr_log_type_bbrrttprop(bbr, rtt, (rsm ? rsm->r_end : 0), uts, cts,
6718 match, rsm->r_start, rsm->r_flags);
6719 apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, cts);
6720 if (old_rttprop != bbr_get_rtt(bbr, BBR_RTT_PROP)) {
6721 /*
6722 * The RTT-prop moved, reset the target (may be a
6723 * nop for some states).
6724 */
6725 bbr_set_state_target(bbr, __LINE__);
6726 if (bbr->rc_bbr_state == BBR_STATE_PROBE_RTT)
6727 bbr_log_rtt_shrinks(bbr, cts, 0, 0,
6728 __LINE__, BBR_RTTS_NEW_TARGET, 0);
6729 else if (old_rttprop < bbr_get_rtt(bbr, BBR_RTT_PROP))
6730 /* It went up */
6731 bbr_check_probe_rtt_limits(bbr, cts);
6732 }
6733 if ((bbr->rc_use_google == 0) &&
6734 (match == BBR_RTT_BY_TIMESTAMP)) {
6735 /*
6736 * We don't do b/w update with
6737 * these since they are not really
6738 * reliable.
6739 */
6740 return;
6741 }
6742 if (bbr->r_ctl.r_app_limited_until &&
6743 (bbr->r_ctl.rc_delivered >= bbr->r_ctl.r_app_limited_until)) {
6744 /* We are no longer app-limited */
6745 bbr->r_ctl.r_app_limited_until = 0;
6746 }
6747 if (bbr->rc_use_google) {
6748 bbr_google_measurement(bbr, rsm, rtt, cts);
6749 } else {
6750 bbr_nf_measurement(bbr, rsm, rtt, cts);
6751 }
6752 }
6753
6754 /*
6755 * Convert a timestamp that the main stack
6756 * uses (milliseconds) into one that bbr uses
6757 * (microseconds). Return that converted timestamp.
6758 */
6759 static uint32_t
bbr_ts_convert(uint32_t cts)6760 bbr_ts_convert(uint32_t cts) {
6761 uint32_t sec, msec;
6762
6763 sec = cts / MS_IN_USEC;
6764 msec = cts - (MS_IN_USEC * sec);
6765 return ((sec * USECS_IN_SECOND) + (msec * MS_IN_USEC));
6766 }
6767
6768 /*
6769 * Return 0 if we did not update the RTT time, return
6770 * 1 if we did.
6771 */
6772 static int
bbr_update_rtt(struct tcpcb * tp,struct tcp_bbr * bbr,struct bbr_sendmap * rsm,struct tcpopt * to,uint32_t cts,int32_t ack_type,uint32_t th_ack)6773 bbr_update_rtt(struct tcpcb *tp, struct tcp_bbr *bbr,
6774 struct bbr_sendmap *rsm, struct tcpopt *to, uint32_t cts, int32_t ack_type, uint32_t th_ack)
6775 {
6776 int32_t i;
6777 uint32_t t, uts = 0;
6778
6779 if ((rsm->r_flags & BBR_ACKED) ||
6780 (rsm->r_flags & BBR_WAS_RENEGED) ||
6781 (rsm->r_flags & BBR_RXT_CLEARED)) {
6782 /* Already done */
6783 return (0);
6784 }
6785 if (rsm->r_rtt_not_allowed) {
6786 /* Not allowed */
6787 return (0);
6788 }
6789 if (rsm->r_rtr_cnt == 1) {
6790 /*
6791 * Only one transmit. Hopefully the normal case.
6792 */
6793 if (TSTMP_GT(cts, rsm->r_tim_lastsent[0]))
6794 t = cts - rsm->r_tim_lastsent[0];
6795 else
6796 t = 1;
6797 if ((int)t <= 0)
6798 t = 1;
6799 bbr->r_ctl.rc_last_rtt = t;
6800 bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, 0,
6801 BBR_RTT_BY_EXACTMATCH, rsm->r_tim_lastsent[0], ack_type, to);
6802 return (1);
6803 }
6804 /* Convert to usecs */
6805 if ((bbr_can_use_ts_for_rtt == 1) &&
6806 (bbr->rc_use_google == 1) &&
6807 (ack_type == BBR_CUM_ACKED) &&
6808 (to->to_flags & TOF_TS) &&
6809 (to->to_tsecr != 0)) {
6810 t = tcp_tv_to_mssectick(&bbr->rc_tv) - to->to_tsecr;
6811 if (t < 1)
6812 t = 1;
6813 t *= MS_IN_USEC;
6814 bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, 0,
6815 BBR_RTT_BY_TIMESTAMP,
6816 rsm->r_tim_lastsent[(rsm->r_rtr_cnt-1)],
6817 ack_type, to);
6818 return (1);
6819 }
6820 uts = bbr_ts_convert(to->to_tsecr);
6821 if ((to->to_flags & TOF_TS) &&
6822 (to->to_tsecr != 0) &&
6823 (ack_type == BBR_CUM_ACKED) &&
6824 ((rsm->r_flags & BBR_OVERMAX) == 0)) {
6825 /*
6826 * Now which timestamp does it match? In this block the ACK
6827 * may be coming from a previous transmission.
6828 */
6829 uint32_t fudge;
6830
6831 fudge = BBR_TIMER_FUDGE;
6832 for (i = 0; i < rsm->r_rtr_cnt; i++) {
6833 if ((SEQ_GEQ(uts, (rsm->r_tim_lastsent[i] - fudge))) &&
6834 (SEQ_LEQ(uts, (rsm->r_tim_lastsent[i] + fudge)))) {
6835 if (TSTMP_GT(cts, rsm->r_tim_lastsent[i]))
6836 t = cts - rsm->r_tim_lastsent[i];
6837 else
6838 t = 1;
6839 if ((int)t <= 0)
6840 t = 1;
6841 bbr->r_ctl.rc_last_rtt = t;
6842 bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, uts, BBR_RTT_BY_TSMATCHING,
6843 rsm->r_tim_lastsent[i], ack_type, to);
6844 if ((i + 1) < rsm->r_rtr_cnt) {
6845 /* Likely */
6846 return (0);
6847 } else if (rsm->r_flags & BBR_TLP) {
6848 bbr->rc_tlp_rtx_out = 0;
6849 }
6850 return (1);
6851 }
6852 }
6853 /* Fall through if we can't find a matching timestamp */
6854 }
6855 /*
6856 * Ok its a SACK block that we retransmitted. or a windows
6857 * machine without timestamps. We can tell nothing from the
6858 * time-stamp since its not there or the time the peer last
6859 * received a segment that moved forward its cum-ack point.
6860 *
6861 * Lets look at the last retransmit and see what we can tell
6862 * (with BBR for space we only keep 2 note we have to keep
6863 * at least 2 so the map can not be condensed more).
6864 */
6865 i = rsm->r_rtr_cnt - 1;
6866 if (TSTMP_GT(cts, rsm->r_tim_lastsent[i]))
6867 t = cts - rsm->r_tim_lastsent[i];
6868 else
6869 goto not_sure;
6870 if (t < bbr->r_ctl.rc_lowest_rtt) {
6871 /*
6872 * We retransmitted and the ack came back in less
6873 * than the smallest rtt we have observed in the
6874 * windowed rtt. We most likey did an improper
6875 * retransmit as outlined in 4.2 Step 3 point 2 in
6876 * the rack-draft.
6877 *
6878 * Use the prior transmission to update all the
6879 * information as long as there is only one prior
6880 * transmission.
6881 */
6882 if ((rsm->r_flags & BBR_OVERMAX) == 0) {
6883 #ifdef BBR_INVARIANTS
6884 if (rsm->r_rtr_cnt == 1)
6885 panic("rsm:%p bbr:%p rsm has overmax and only 1 retranmit flags:%x?", rsm, bbr, rsm->r_flags);
6886 #endif
6887 i = rsm->r_rtr_cnt - 2;
6888 if (TSTMP_GT(cts, rsm->r_tim_lastsent[i]))
6889 t = cts - rsm->r_tim_lastsent[i];
6890 else
6891 t = 1;
6892 bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, uts, BBR_RTT_BY_EARLIER_RET,
6893 rsm->r_tim_lastsent[i], ack_type, to);
6894 return (0);
6895 } else {
6896 /*
6897 * Too many prior transmissions, just
6898 * updated BBR delivered
6899 */
6900 not_sure:
6901 bbr_update_bbr_info(bbr, rsm, 0, cts, to->to_tsecr, uts,
6902 BBR_RTT_BY_SOME_RETRAN, 0, ack_type, to);
6903 }
6904 } else {
6905 /*
6906 * We retransmitted it and the retransmit did the
6907 * job.
6908 */
6909 if (rsm->r_flags & BBR_TLP)
6910 bbr->rc_tlp_rtx_out = 0;
6911 if ((rsm->r_flags & BBR_OVERMAX) == 0)
6912 bbr_update_bbr_info(bbr, rsm, t, cts, to->to_tsecr, uts,
6913 BBR_RTT_BY_THIS_RETRAN, 0, ack_type, to);
6914 else
6915 bbr_update_bbr_info(bbr, rsm, 0, cts, to->to_tsecr, uts,
6916 BBR_RTT_BY_SOME_RETRAN, 0, ack_type, to);
6917 return (1);
6918 }
6919 return (0);
6920 }
6921
6922 /*
6923 * Mark the SACK_PASSED flag on all entries prior to rsm send wise.
6924 */
6925 static void
bbr_log_sack_passed(struct tcpcb * tp,struct tcp_bbr * bbr,struct bbr_sendmap * rsm)6926 bbr_log_sack_passed(struct tcpcb *tp,
6927 struct tcp_bbr *bbr, struct bbr_sendmap *rsm)
6928 {
6929 struct bbr_sendmap *nrsm;
6930
6931 nrsm = rsm;
6932 TAILQ_FOREACH_REVERSE_FROM(nrsm, &bbr->r_ctl.rc_tmap,
6933 bbr_head, r_tnext) {
6934 if (nrsm == rsm) {
6935 /* Skip original segment he is acked */
6936 continue;
6937 }
6938 if (nrsm->r_flags & BBR_ACKED) {
6939 /* Skip ack'd segments */
6940 continue;
6941 }
6942 if (nrsm->r_flags & BBR_SACK_PASSED) {
6943 /*
6944 * We found one that is already marked
6945 * passed, we have been here before and
6946 * so all others below this are marked.
6947 */
6948 break;
6949 }
6950 BBR_STAT_INC(bbr_sack_passed);
6951 nrsm->r_flags |= BBR_SACK_PASSED;
6952 if (((nrsm->r_flags & BBR_MARKED_LOST) == 0) &&
6953 bbr_is_lost(bbr, nrsm, bbr->r_ctl.rc_rcvtime)) {
6954 bbr->r_ctl.rc_lost += nrsm->r_end - nrsm->r_start;
6955 bbr->r_ctl.rc_lost_bytes += nrsm->r_end - nrsm->r_start;
6956 nrsm->r_flags |= BBR_MARKED_LOST;
6957 }
6958 nrsm->r_flags &= ~BBR_WAS_SACKPASS;
6959 }
6960 }
6961
6962 /*
6963 * Returns the number of bytes that were
6964 * newly ack'd by sack blocks.
6965 */
6966 static uint32_t
bbr_proc_sack_blk(struct tcpcb * tp,struct tcp_bbr * bbr,struct sackblk * sack,struct tcpopt * to,struct bbr_sendmap ** prsm,uint32_t cts)6967 bbr_proc_sack_blk(struct tcpcb *tp, struct tcp_bbr *bbr, struct sackblk *sack,
6968 struct tcpopt *to, struct bbr_sendmap **prsm, uint32_t cts)
6969 {
6970 int32_t times = 0;
6971 uint32_t start, end, changed = 0;
6972 struct bbr_sendmap *rsm, *nrsm;
6973 int32_t used_ref = 1;
6974 uint8_t went_back = 0, went_fwd = 0;
6975
6976 start = sack->start;
6977 end = sack->end;
6978 rsm = *prsm;
6979 if (rsm == NULL)
6980 used_ref = 0;
6981
6982 /* Do we locate the block behind where we last were? */
6983 if (rsm && SEQ_LT(start, rsm->r_start)) {
6984 went_back = 1;
6985 TAILQ_FOREACH_REVERSE_FROM(rsm, &bbr->r_ctl.rc_map, bbr_head, r_next) {
6986 if (SEQ_GEQ(start, rsm->r_start) &&
6987 SEQ_LT(start, rsm->r_end)) {
6988 goto do_rest_ofb;
6989 }
6990 }
6991 }
6992 start_at_beginning:
6993 went_fwd = 1;
6994 /*
6995 * Ok lets locate the block where this guy is fwd from rsm (if its
6996 * set)
6997 */
6998 TAILQ_FOREACH_FROM(rsm, &bbr->r_ctl.rc_map, r_next) {
6999 if (SEQ_GEQ(start, rsm->r_start) &&
7000 SEQ_LT(start, rsm->r_end)) {
7001 break;
7002 }
7003 }
7004 do_rest_ofb:
7005 if (rsm == NULL) {
7006 /*
7007 * This happens when we get duplicate sack blocks with the
7008 * same end. For example SACK 4: 100 SACK 3: 100 The sort
7009 * will not change there location so we would just start at
7010 * the end of the first one and get lost.
7011 */
7012 if (tp->t_flags & TF_SENTFIN) {
7013 /*
7014 * Check to see if we have not logged the FIN that
7015 * went out.
7016 */
7017 nrsm = TAILQ_LAST_FAST(&bbr->r_ctl.rc_map, bbr_sendmap, r_next);
7018 if (nrsm && (nrsm->r_end + 1) == tp->snd_max) {
7019 /*
7020 * Ok we did not get the FIN logged.
7021 */
7022 nrsm->r_end++;
7023 rsm = nrsm;
7024 goto do_rest_ofb;
7025 }
7026 }
7027 if (times == 1) {
7028 #ifdef BBR_INVARIANTS
7029 panic("tp:%p bbr:%p sack:%p to:%p prsm:%p",
7030 tp, bbr, sack, to, prsm);
7031 #else
7032 goto out;
7033 #endif
7034 }
7035 times++;
7036 BBR_STAT_INC(bbr_sack_proc_restart);
7037 rsm = NULL;
7038 goto start_at_beginning;
7039 }
7040 /* Ok we have an ACK for some piece of rsm */
7041 if (rsm->r_start != start) {
7042 /*
7043 * Need to split this in two pieces the before and after.
7044 */
7045 if (bbr_sack_mergable(rsm, start, end))
7046 nrsm = bbr_alloc_full_limit(bbr);
7047 else
7048 nrsm = bbr_alloc_limit(bbr, BBR_LIMIT_TYPE_SPLIT);
7049 if (nrsm == NULL) {
7050 /* We could not allocate ignore the sack */
7051 struct sackblk blk;
7052
7053 blk.start = start;
7054 blk.end = end;
7055 sack_filter_reject(&bbr->r_ctl.bbr_sf, &blk);
7056 goto out;
7057 }
7058 bbr_clone_rsm(bbr, nrsm, rsm, start);
7059 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
7060 if (rsm->r_in_tmap) {
7061 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7062 nrsm->r_in_tmap = 1;
7063 }
7064 rsm->r_flags &= (~BBR_HAS_FIN);
7065 rsm = nrsm;
7066 }
7067 if (SEQ_GEQ(end, rsm->r_end)) {
7068 /*
7069 * The end of this block is either beyond this guy or right
7070 * at this guy.
7071 */
7072 if ((rsm->r_flags & BBR_ACKED) == 0) {
7073 bbr_update_rtt(tp, bbr, rsm, to, cts, BBR_SACKED, 0);
7074 changed += (rsm->r_end - rsm->r_start);
7075 bbr->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
7076 bbr_log_sack_passed(tp, bbr, rsm);
7077 if (rsm->r_flags & BBR_MARKED_LOST) {
7078 bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
7079 }
7080 /* Is Reordering occuring? */
7081 if (rsm->r_flags & BBR_SACK_PASSED) {
7082 BBR_STAT_INC(bbr_reorder_seen);
7083 bbr->r_ctl.rc_reorder_ts = cts;
7084 if (rsm->r_flags & BBR_MARKED_LOST) {
7085 bbr->r_ctl.rc_lost -= rsm->r_end - rsm->r_start;
7086 if (SEQ_GT(bbr->r_ctl.rc_lt_lost, bbr->r_ctl.rc_lost))
7087 /* LT sampling also needs adjustment */
7088 bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
7089 }
7090 }
7091 rsm->r_flags |= BBR_ACKED;
7092 rsm->r_flags &= ~(BBR_TLP|BBR_WAS_RENEGED|BBR_RXT_CLEARED|BBR_MARKED_LOST);
7093 if (rsm->r_in_tmap) {
7094 TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
7095 rsm->r_in_tmap = 0;
7096 }
7097 }
7098 bbr_isit_a_pkt_epoch(bbr, cts, rsm, __LINE__, BBR_SACKED);
7099 if (end == rsm->r_end) {
7100 /* This block only - done */
7101 goto out;
7102 }
7103 /* There is more not coverend by this rsm move on */
7104 start = rsm->r_end;
7105 nrsm = TAILQ_NEXT(rsm, r_next);
7106 rsm = nrsm;
7107 times = 0;
7108 goto do_rest_ofb;
7109 }
7110 if (rsm->r_flags & BBR_ACKED) {
7111 /* Been here done that */
7112 goto out;
7113 }
7114 /* Ok we need to split off this one at the tail */
7115 if (bbr_sack_mergable(rsm, start, end))
7116 nrsm = bbr_alloc_full_limit(bbr);
7117 else
7118 nrsm = bbr_alloc_limit(bbr, BBR_LIMIT_TYPE_SPLIT);
7119 if (nrsm == NULL) {
7120 /* failed XXXrrs what can we do but loose the sack info? */
7121 struct sackblk blk;
7122
7123 blk.start = start;
7124 blk.end = end;
7125 sack_filter_reject(&bbr->r_ctl.bbr_sf, &blk);
7126 goto out;
7127 }
7128 /* Clone it */
7129 bbr_clone_rsm(bbr, nrsm, rsm, end);
7130 /* The sack block does not cover this guy fully */
7131 rsm->r_flags &= (~BBR_HAS_FIN);
7132 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
7133 if (rsm->r_in_tmap) {
7134 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
7135 nrsm->r_in_tmap = 1;
7136 }
7137 nrsm->r_dupack = 0;
7138 bbr_update_rtt(tp, bbr, rsm, to, cts, BBR_SACKED, 0);
7139 bbr_isit_a_pkt_epoch(bbr, cts, rsm, __LINE__, BBR_SACKED);
7140 changed += (rsm->r_end - rsm->r_start);
7141 bbr->r_ctl.rc_sacked += (rsm->r_end - rsm->r_start);
7142 bbr_log_sack_passed(tp, bbr, rsm);
7143 /* Is Reordering occuring? */
7144 if (rsm->r_flags & BBR_MARKED_LOST) {
7145 bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
7146 }
7147 if (rsm->r_flags & BBR_SACK_PASSED) {
7148 BBR_STAT_INC(bbr_reorder_seen);
7149 bbr->r_ctl.rc_reorder_ts = cts;
7150 if (rsm->r_flags & BBR_MARKED_LOST) {
7151 bbr->r_ctl.rc_lost -= rsm->r_end - rsm->r_start;
7152 if (SEQ_GT(bbr->r_ctl.rc_lt_lost, bbr->r_ctl.rc_lost))
7153 /* LT sampling also needs adjustment */
7154 bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
7155 }
7156 }
7157 rsm->r_flags &= ~(BBR_TLP|BBR_WAS_RENEGED|BBR_RXT_CLEARED|BBR_MARKED_LOST);
7158 rsm->r_flags |= BBR_ACKED;
7159 if (rsm->r_in_tmap) {
7160 TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
7161 rsm->r_in_tmap = 0;
7162 }
7163 out:
7164 if (rsm && (rsm->r_flags & BBR_ACKED)) {
7165 /*
7166 * Now can we merge this newly acked
7167 * block with either the previous or
7168 * next block?
7169 */
7170 nrsm = TAILQ_NEXT(rsm, r_next);
7171 if (nrsm &&
7172 (nrsm->r_flags & BBR_ACKED)) {
7173 /* yep this and next can be merged */
7174 rsm = bbr_merge_rsm(bbr, rsm, nrsm);
7175 }
7176 /* Now what about the previous? */
7177 nrsm = TAILQ_PREV(rsm, bbr_head, r_next);
7178 if (nrsm &&
7179 (nrsm->r_flags & BBR_ACKED)) {
7180 /* yep the previous and this can be merged */
7181 rsm = bbr_merge_rsm(bbr, nrsm, rsm);
7182 }
7183 }
7184 if (used_ref == 0) {
7185 BBR_STAT_INC(bbr_sack_proc_all);
7186 } else {
7187 BBR_STAT_INC(bbr_sack_proc_short);
7188 }
7189 if (went_fwd && went_back) {
7190 BBR_STAT_INC(bbr_sack_search_both);
7191 } else if (went_fwd) {
7192 BBR_STAT_INC(bbr_sack_search_fwd);
7193 } else if (went_back) {
7194 BBR_STAT_INC(bbr_sack_search_back);
7195 }
7196 /* Save off where the next seq is */
7197 if (rsm)
7198 bbr->r_ctl.rc_sacklast = TAILQ_NEXT(rsm, r_next);
7199 else
7200 bbr->r_ctl.rc_sacklast = NULL;
7201 *prsm = rsm;
7202 return (changed);
7203 }
7204
7205 static void inline
bbr_peer_reneges(struct tcp_bbr * bbr,struct bbr_sendmap * rsm,tcp_seq th_ack)7206 bbr_peer_reneges(struct tcp_bbr *bbr, struct bbr_sendmap *rsm, tcp_seq th_ack)
7207 {
7208 struct bbr_sendmap *tmap;
7209
7210 BBR_STAT_INC(bbr_reneges_seen);
7211 tmap = NULL;
7212 while (rsm && (rsm->r_flags & BBR_ACKED)) {
7213 /* Its no longer sacked, mark it so */
7214 uint32_t oflags;
7215 bbr->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
7216 #ifdef BBR_INVARIANTS
7217 if (rsm->r_in_tmap) {
7218 panic("bbr:%p rsm:%p flags:0x%x in tmap?",
7219 bbr, rsm, rsm->r_flags);
7220 }
7221 #endif
7222 oflags = rsm->r_flags;
7223 if (rsm->r_flags & BBR_MARKED_LOST) {
7224 bbr->r_ctl.rc_lost -= rsm->r_end - rsm->r_start;
7225 bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
7226 if (SEQ_GT(bbr->r_ctl.rc_lt_lost, bbr->r_ctl.rc_lost))
7227 /* LT sampling also needs adjustment */
7228 bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
7229 }
7230 rsm->r_flags &= ~(BBR_ACKED | BBR_SACK_PASSED | BBR_WAS_SACKPASS | BBR_MARKED_LOST);
7231 rsm->r_flags |= BBR_WAS_RENEGED;
7232 rsm->r_flags |= BBR_RXT_CLEARED;
7233 bbr_log_type_rsmclear(bbr, bbr->r_ctl.rc_rcvtime, rsm, oflags, __LINE__);
7234 /* Rebuild it into our tmap */
7235 if (tmap == NULL) {
7236 TAILQ_INSERT_HEAD(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
7237 tmap = rsm;
7238 } else {
7239 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, tmap, rsm, r_tnext);
7240 tmap = rsm;
7241 }
7242 tmap->r_in_tmap = 1;
7243 /*
7244 * XXXrrs Delivered? Should we do anything here?
7245 *
7246 * Of course we don't on a rxt timeout so maybe its ok that
7247 * we don't?
7248 *
7249 * For now lets not.
7250 */
7251 rsm = TAILQ_NEXT(rsm, r_next);
7252 }
7253 /*
7254 * Now lets possibly clear the sack filter so we start recognizing
7255 * sacks that cover this area.
7256 */
7257 sack_filter_clear(&bbr->r_ctl.bbr_sf, th_ack);
7258 }
7259
7260 static void
bbr_log_syn(struct tcpcb * tp,struct tcpopt * to)7261 bbr_log_syn(struct tcpcb *tp, struct tcpopt *to)
7262 {
7263 struct tcp_bbr *bbr;
7264 struct bbr_sendmap *rsm;
7265 uint32_t cts;
7266
7267 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
7268 cts = bbr->r_ctl.rc_rcvtime;
7269 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
7270 if (rsm && (rsm->r_flags & BBR_HAS_SYN)) {
7271 if ((rsm->r_end - rsm->r_start) <= 1) {
7272 /* Log out the SYN completely */
7273 bbr->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
7274 rsm->r_rtr_bytes = 0;
7275 TAILQ_REMOVE(&bbr->r_ctl.rc_map, rsm, r_next);
7276 if (rsm->r_in_tmap) {
7277 TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
7278 rsm->r_in_tmap = 0;
7279 }
7280 if (bbr->r_ctl.rc_next == rsm) {
7281 /* scoot along the marker */
7282 bbr->r_ctl.rc_next = TAILQ_FIRST(&bbr->r_ctl.rc_map);
7283 }
7284 if (to != NULL)
7285 bbr_update_rtt(tp, bbr, rsm, to, cts, BBR_CUM_ACKED, 0);
7286 bbr_free(bbr, rsm);
7287 } else {
7288 /* There is more (Fast open)? strip out SYN. */
7289 rsm->r_flags &= ~BBR_HAS_SYN;
7290 rsm->r_start++;
7291 }
7292 }
7293 }
7294
7295 /*
7296 * Returns the number of bytes that were
7297 * acknowledged by SACK blocks.
7298 */
7299
7300 static uint32_t
bbr_log_ack(struct tcpcb * tp,struct tcpopt * to,struct tcphdr * th,uint32_t * prev_acked)7301 bbr_log_ack(struct tcpcb *tp, struct tcpopt *to, struct tcphdr *th,
7302 uint32_t *prev_acked)
7303 {
7304 uint32_t changed, last_seq, entered_recovery = 0;
7305 struct tcp_bbr *bbr;
7306 struct bbr_sendmap *rsm;
7307 struct sackblk sack, sack_blocks[TCP_MAX_SACK + 1];
7308 register uint32_t th_ack;
7309 int32_t i, j, k, new_sb, num_sack_blks = 0;
7310 uint32_t cts, acked, ack_point, sack_changed = 0;
7311 uint32_t p_maxseg, maxseg, p_acked = 0;
7312
7313 INP_WLOCK_ASSERT(tptoinpcb(tp));
7314 if (tcp_get_flags(th) & TH_RST) {
7315 /* We don't log resets */
7316 return (0);
7317 }
7318 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
7319 cts = bbr->r_ctl.rc_rcvtime;
7320
7321 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
7322 changed = 0;
7323 maxseg = tp->t_maxseg - bbr->rc_last_options;
7324 p_maxseg = min(bbr->r_ctl.rc_pace_max_segs, maxseg);
7325 th_ack = th->th_ack;
7326 if (SEQ_GT(th_ack, tp->snd_una)) {
7327 acked = th_ack - tp->snd_una;
7328 bbr_log_progress_event(bbr, tp, ticks, PROGRESS_UPDATE, __LINE__);
7329 bbr->rc_tp->t_acktime = ticks;
7330 } else
7331 acked = 0;
7332 if (SEQ_LEQ(th_ack, tp->snd_una)) {
7333 /* Only sent here for sack processing */
7334 goto proc_sack;
7335 }
7336 if (rsm && SEQ_GT(th_ack, rsm->r_start)) {
7337 changed = th_ack - rsm->r_start;
7338 } else if ((rsm == NULL) && ((th_ack - 1) == tp->iss)) {
7339 /*
7340 * For the SYN incoming case we will not have called
7341 * tcp_output for the sending of the SYN, so there will be
7342 * no map. All other cases should probably be a panic.
7343 */
7344 if ((to->to_flags & TOF_TS) && (to->to_tsecr != 0)) {
7345 /*
7346 * We have a timestamp that can be used to generate
7347 * an initial RTT.
7348 */
7349 uint32_t ts, now, rtt;
7350
7351 ts = bbr_ts_convert(to->to_tsecr);
7352 now = bbr_ts_convert(tcp_tv_to_mssectick(&bbr->rc_tv));
7353 rtt = now - ts;
7354 if (rtt < 1)
7355 rtt = 1;
7356 bbr_log_type_bbrrttprop(bbr, rtt,
7357 tp->iss, 0, cts,
7358 BBR_RTT_BY_TIMESTAMP, tp->iss, 0);
7359 apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, cts);
7360 changed = 1;
7361 bbr->r_wanted_output = 1;
7362 goto out;
7363 }
7364 goto proc_sack;
7365 } else if (rsm == NULL) {
7366 goto out;
7367 }
7368 if (changed) {
7369 /*
7370 * The ACK point is advancing to th_ack, we must drop off
7371 * the packets in the rack log and calculate any eligble
7372 * RTT's.
7373 */
7374 bbr->r_wanted_output = 1;
7375 more:
7376 if (rsm == NULL) {
7377 if (tp->t_flags & TF_SENTFIN) {
7378 /* if we send a FIN we will not hav a map */
7379 goto proc_sack;
7380 }
7381 #ifdef BBR_INVARIANTS
7382 panic("No rack map tp:%p for th:%p state:%d bbr:%p snd_una:%u snd_max:%u chg:%d\n",
7383 tp,
7384 th, tp->t_state, bbr,
7385 tp->snd_una, tp->snd_max, changed);
7386 #endif
7387 goto proc_sack;
7388 }
7389 }
7390 if (SEQ_LT(th_ack, rsm->r_start)) {
7391 /* Huh map is missing this */
7392 #ifdef BBR_INVARIANTS
7393 printf("Rack map starts at r_start:%u for th_ack:%u huh? ts:%d rs:%d bbr:%p\n",
7394 rsm->r_start,
7395 th_ack, tp->t_state,
7396 bbr->r_state, bbr);
7397 panic("th-ack is bad bbr:%p tp:%p", bbr, tp);
7398 #endif
7399 goto proc_sack;
7400 } else if (th_ack == rsm->r_start) {
7401 /* None here to ack */
7402 goto proc_sack;
7403 }
7404 /*
7405 * Clear the dup ack counter, it will
7406 * either be freed or if there is some
7407 * remaining we need to start it at zero.
7408 */
7409 rsm->r_dupack = 0;
7410 /* Now do we consume the whole thing? */
7411 if (SEQ_GEQ(th_ack, rsm->r_end)) {
7412 /* Its all consumed. */
7413 uint32_t left;
7414
7415 if (rsm->r_flags & BBR_ACKED) {
7416 /*
7417 * It was acked on the scoreboard -- remove it from
7418 * total
7419 */
7420 p_acked += (rsm->r_end - rsm->r_start);
7421 bbr->r_ctl.rc_sacked -= (rsm->r_end - rsm->r_start);
7422 if (bbr->r_ctl.rc_sacked == 0)
7423 bbr->r_ctl.rc_sacklast = NULL;
7424 } else {
7425 bbr_update_rtt(tp, bbr, rsm, to, cts, BBR_CUM_ACKED, th_ack);
7426 if (rsm->r_flags & BBR_MARKED_LOST) {
7427 bbr->r_ctl.rc_lost_bytes -= rsm->r_end - rsm->r_start;
7428 }
7429 if (rsm->r_flags & BBR_SACK_PASSED) {
7430 /*
7431 * There are acked segments ACKED on the
7432 * scoreboard further up. We are seeing
7433 * reordering.
7434 */
7435 BBR_STAT_INC(bbr_reorder_seen);
7436 bbr->r_ctl.rc_reorder_ts = cts;
7437 if (rsm->r_flags & BBR_MARKED_LOST) {
7438 bbr->r_ctl.rc_lost -= rsm->r_end - rsm->r_start;
7439 if (SEQ_GT(bbr->r_ctl.rc_lt_lost, bbr->r_ctl.rc_lost))
7440 /* LT sampling also needs adjustment */
7441 bbr->r_ctl.rc_lt_lost = bbr->r_ctl.rc_lost;
7442 }
7443 }
7444 rsm->r_flags &= ~BBR_MARKED_LOST;
7445 }
7446 bbr->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
7447 rsm->r_rtr_bytes = 0;
7448 TAILQ_REMOVE(&bbr->r_ctl.rc_map, rsm, r_next);
7449 if (rsm->r_in_tmap) {
7450 TAILQ_REMOVE(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
7451 rsm->r_in_tmap = 0;
7452 }
7453 if (bbr->r_ctl.rc_next == rsm) {
7454 /* scoot along the marker */
7455 bbr->r_ctl.rc_next = TAILQ_FIRST(&bbr->r_ctl.rc_map);
7456 }
7457 bbr_isit_a_pkt_epoch(bbr, cts, rsm, __LINE__, BBR_CUM_ACKED);
7458 /* Adjust the packet counts */
7459 left = th_ack - rsm->r_end;
7460 /* Free back to zone */
7461 bbr_free(bbr, rsm);
7462 if (left) {
7463 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
7464 goto more;
7465 }
7466 goto proc_sack;
7467 }
7468 if (rsm->r_flags & BBR_ACKED) {
7469 /*
7470 * It was acked on the scoreboard -- remove it from total
7471 * for the part being cum-acked.
7472 */
7473 p_acked += (rsm->r_end - rsm->r_start);
7474 bbr->r_ctl.rc_sacked -= (th_ack - rsm->r_start);
7475 if (bbr->r_ctl.rc_sacked == 0)
7476 bbr->r_ctl.rc_sacklast = NULL;
7477 } else {
7478 /*
7479 * It was acked up to th_ack point for the first time
7480 */
7481 struct bbr_sendmap lrsm;
7482
7483 memcpy(&lrsm, rsm, sizeof(struct bbr_sendmap));
7484 lrsm.r_end = th_ack;
7485 bbr_update_rtt(tp, bbr, &lrsm, to, cts, BBR_CUM_ACKED, th_ack);
7486 }
7487 if ((rsm->r_flags & BBR_MARKED_LOST) &&
7488 ((rsm->r_flags & BBR_ACKED) == 0)) {
7489 /*
7490 * It was marked lost and partly ack'd now
7491 * for the first time. We lower the rc_lost_bytes
7492 * and still leave it MARKED.
7493 */
7494 bbr->r_ctl.rc_lost_bytes -= th_ack - rsm->r_start;
7495 }
7496 bbr_isit_a_pkt_epoch(bbr, cts, rsm, __LINE__, BBR_CUM_ACKED);
7497 bbr->r_ctl.rc_holes_rxt -= rsm->r_rtr_bytes;
7498 rsm->r_rtr_bytes = 0;
7499 /* adjust packet count */
7500 rsm->r_start = th_ack;
7501 proc_sack:
7502 /* Check for reneging */
7503 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
7504 if (rsm && (rsm->r_flags & BBR_ACKED) && (th_ack == rsm->r_start)) {
7505 /*
7506 * The peer has moved snd_una up to the edge of this send,
7507 * i.e. one that it had previously acked. The only way that
7508 * can be true if the peer threw away data (space issues)
7509 * that it had previously sacked (else it would have given
7510 * us snd_una up to (rsm->r_end). We need to undo the acked
7511 * markings here.
7512 *
7513 * Note we have to look to make sure th_ack is our
7514 * rsm->r_start in case we get an old ack where th_ack is
7515 * behind snd_una.
7516 */
7517 bbr_peer_reneges(bbr, rsm, th->th_ack);
7518 }
7519 if ((to->to_flags & TOF_SACK) == 0) {
7520 /* We are done nothing left to log */
7521 goto out;
7522 }
7523 rsm = TAILQ_LAST_FAST(&bbr->r_ctl.rc_map, bbr_sendmap, r_next);
7524 if (rsm) {
7525 last_seq = rsm->r_end;
7526 } else {
7527 last_seq = tp->snd_max;
7528 }
7529 /* Sack block processing */
7530 if (SEQ_GT(th_ack, tp->snd_una))
7531 ack_point = th_ack;
7532 else
7533 ack_point = tp->snd_una;
7534 for (i = 0; i < to->to_nsacks; i++) {
7535 bcopy((to->to_sacks + i * TCPOLEN_SACK),
7536 &sack, sizeof(sack));
7537 sack.start = ntohl(sack.start);
7538 sack.end = ntohl(sack.end);
7539 if (SEQ_GT(sack.end, sack.start) &&
7540 SEQ_GT(sack.start, ack_point) &&
7541 SEQ_LT(sack.start, tp->snd_max) &&
7542 SEQ_GT(sack.end, ack_point) &&
7543 SEQ_LEQ(sack.end, tp->snd_max)) {
7544 if ((bbr->r_ctl.rc_num_small_maps_alloced > bbr_sack_block_limit) &&
7545 (SEQ_LT(sack.end, last_seq)) &&
7546 ((sack.end - sack.start) < (p_maxseg / 8))) {
7547 /*
7548 * Not the last piece and its smaller than
7549 * 1/8th of a p_maxseg. We ignore this.
7550 */
7551 BBR_STAT_INC(bbr_runt_sacks);
7552 continue;
7553 }
7554 sack_blocks[num_sack_blks] = sack;
7555 num_sack_blks++;
7556 } else if (SEQ_LEQ(sack.start, th_ack) &&
7557 SEQ_LEQ(sack.end, th_ack)) {
7558 /*
7559 * Its a D-SACK block.
7560 */
7561 tcp_record_dsack(tp, sack.start, sack.end, 0);
7562 }
7563 }
7564 if (num_sack_blks == 0)
7565 goto out;
7566 /*
7567 * Sort the SACK blocks so we can update the rack scoreboard with
7568 * just one pass.
7569 */
7570 new_sb = sack_filter_blks(tp, &bbr->r_ctl.bbr_sf, sack_blocks,
7571 num_sack_blks, th->th_ack);
7572 ctf_log_sack_filter(bbr->rc_tp, new_sb, sack_blocks);
7573 BBR_STAT_ADD(bbr_sack_blocks, num_sack_blks);
7574 BBR_STAT_ADD(bbr_sack_blocks_skip, (num_sack_blks - new_sb));
7575 num_sack_blks = new_sb;
7576 if (num_sack_blks < 2) {
7577 goto do_sack_work;
7578 }
7579 /* Sort the sacks */
7580 for (i = 0; i < num_sack_blks; i++) {
7581 for (j = i + 1; j < num_sack_blks; j++) {
7582 if (SEQ_GT(sack_blocks[i].end, sack_blocks[j].end)) {
7583 sack = sack_blocks[i];
7584 sack_blocks[i] = sack_blocks[j];
7585 sack_blocks[j] = sack;
7586 }
7587 }
7588 }
7589 /*
7590 * Now are any of the sack block ends the same (yes some
7591 * implememtations send these)?
7592 */
7593 again:
7594 if (num_sack_blks > 1) {
7595 for (i = 0; i < num_sack_blks; i++) {
7596 for (j = i + 1; j < num_sack_blks; j++) {
7597 if (sack_blocks[i].end == sack_blocks[j].end) {
7598 /*
7599 * Ok these two have the same end we
7600 * want the smallest end and then
7601 * throw away the larger and start
7602 * again.
7603 */
7604 if (SEQ_LT(sack_blocks[j].start, sack_blocks[i].start)) {
7605 /*
7606 * The second block covers
7607 * more area use that
7608 */
7609 sack_blocks[i].start = sack_blocks[j].start;
7610 }
7611 /*
7612 * Now collapse out the dup-sack and
7613 * lower the count
7614 */
7615 for (k = (j + 1); k < num_sack_blks; k++) {
7616 sack_blocks[j].start = sack_blocks[k].start;
7617 sack_blocks[j].end = sack_blocks[k].end;
7618 j++;
7619 }
7620 num_sack_blks--;
7621 goto again;
7622 }
7623 }
7624 }
7625 }
7626 do_sack_work:
7627 rsm = bbr->r_ctl.rc_sacklast;
7628 for (i = 0; i < num_sack_blks; i++) {
7629 acked = bbr_proc_sack_blk(tp, bbr, &sack_blocks[i], to, &rsm, cts);
7630 if (acked) {
7631 bbr->r_wanted_output = 1;
7632 changed += acked;
7633 sack_changed += acked;
7634 }
7635 }
7636 out:
7637 *prev_acked = p_acked;
7638 if ((sack_changed) && (!IN_RECOVERY(tp->t_flags))) {
7639 /*
7640 * Ok we have a high probability that we need to go in to
7641 * recovery since we have data sack'd
7642 */
7643 struct bbr_sendmap *rsm;
7644
7645 rsm = bbr_check_recovery_mode(tp, bbr, cts);
7646 if (rsm) {
7647 /* Enter recovery */
7648 entered_recovery = 1;
7649 bbr->r_wanted_output = 1;
7650 /*
7651 * When we enter recovery we need to assure we send
7652 * one packet.
7653 */
7654 if (bbr->r_ctl.rc_resend == NULL) {
7655 bbr->r_ctl.rc_resend = rsm;
7656 }
7657 }
7658 }
7659 if (IN_RECOVERY(tp->t_flags) && (entered_recovery == 0)) {
7660 /*
7661 * See if we need to rack-retransmit anything if so set it
7662 * up as the thing to resend assuming something else is not
7663 * already in that position.
7664 */
7665 if (bbr->r_ctl.rc_resend == NULL) {
7666 bbr->r_ctl.rc_resend = bbr_check_recovery_mode(tp, bbr, cts);
7667 }
7668 }
7669 /*
7670 * We return the amount that changed via sack, this is used by the
7671 * ack-received code to augment what was changed between th_ack <->
7672 * snd_una.
7673 */
7674 return (sack_changed);
7675 }
7676
7677 static void
bbr_strike_dupack(struct tcp_bbr * bbr)7678 bbr_strike_dupack(struct tcp_bbr *bbr)
7679 {
7680 struct bbr_sendmap *rsm;
7681
7682 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_tmap);
7683 if (rsm && (rsm->r_dupack < 0xff)) {
7684 rsm->r_dupack++;
7685 if (rsm->r_dupack >= DUP_ACK_THRESHOLD)
7686 bbr->r_wanted_output = 1;
7687 }
7688 }
7689
7690 /*
7691 * Return value of 1, we do not need to call bbr_process_data().
7692 * return value of 0, bbr_process_data can be called.
7693 * For ret_val if its 0 the TCB is locked and valid, if its non-zero
7694 * its unlocked and probably unsafe to touch the TCB.
7695 */
7696 static int
bbr_process_ack(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,uint32_t tiwin,int32_t tlen,int32_t * ofia,int32_t thflags,int32_t * ret_val)7697 bbr_process_ack(struct mbuf *m, struct tcphdr *th, struct socket *so,
7698 struct tcpcb *tp, struct tcpopt *to,
7699 uint32_t tiwin, int32_t tlen,
7700 int32_t * ofia, int32_t thflags, int32_t * ret_val)
7701 {
7702 int32_t ourfinisacked = 0;
7703 int32_t acked_amount;
7704 uint16_t nsegs;
7705 int32_t acked;
7706 uint32_t lost, sack_changed = 0;
7707 struct mbuf *mfree;
7708 struct tcp_bbr *bbr;
7709 uint32_t prev_acked = 0;
7710
7711 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
7712 lost = bbr->r_ctl.rc_lost;
7713 nsegs = max(1, m->m_pkthdr.lro_nsegs);
7714 if (SEQ_GEQ(tp->snd_una, tp->iss + (65535 << tp->snd_scale))) {
7715 /* Checking SEG.ACK against ISS is definitely redundant. */
7716 tp->t_flags2 |= TF2_NO_ISS_CHECK;
7717 }
7718 if (!V_tcp_insecure_ack) {
7719 tcp_seq seq_min;
7720 bool ghost_ack_check;
7721
7722 if (tp->t_flags2 & TF2_NO_ISS_CHECK) {
7723 /* Check for too old ACKs (RFC 5961, Section 5.2). */
7724 seq_min = tp->snd_una - tp->max_sndwnd;
7725 ghost_ack_check = false;
7726 } else {
7727 if (SEQ_GT(tp->iss + 1, tp->snd_una - tp->max_sndwnd)) {
7728 /* Checking for ghost ACKs is stricter. */
7729 seq_min = tp->iss + 1;
7730 ghost_ack_check = true;
7731 } else {
7732 /*
7733 * Checking for too old ACKs (RFC 5961,
7734 * Section 5.2) is stricter.
7735 */
7736 seq_min = tp->snd_una - tp->max_sndwnd;
7737 ghost_ack_check = false;
7738 }
7739 }
7740 if (SEQ_LT(th->th_ack, seq_min)) {
7741 if (ghost_ack_check)
7742 TCPSTAT_INC(tcps_rcvghostack);
7743 else
7744 TCPSTAT_INC(tcps_rcvacktooold);
7745 /* Send challenge ACK. */
7746 ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val);
7747 bbr->r_wanted_output = 1;
7748 return (1);
7749 }
7750 }
7751 if (SEQ_GT(th->th_ack, tp->snd_max)) {
7752 ctf_do_dropafterack(m, tp, th, thflags, tlen, ret_val);
7753 bbr->r_wanted_output = 1;
7754 return (1);
7755 }
7756 if (SEQ_GEQ(th->th_ack, tp->snd_una) || to->to_nsacks) {
7757 /* Process the ack */
7758 if (bbr->rc_in_persist)
7759 tp->t_rxtshift = 0;
7760 if ((th->th_ack == tp->snd_una) && (tiwin == tp->snd_wnd))
7761 bbr_strike_dupack(bbr);
7762 sack_changed = bbr_log_ack(tp, to, th, &prev_acked);
7763 }
7764 bbr_lt_bw_sampling(bbr, bbr->r_ctl.rc_rcvtime, (bbr->r_ctl.rc_lost > lost));
7765 if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
7766 /*
7767 * Old ack, behind the last one rcv'd or a duplicate ack
7768 * with SACK info.
7769 */
7770 if (th->th_ack == tp->snd_una) {
7771 bbr_ack_received(tp, bbr, th, 0, sack_changed, prev_acked, __LINE__, 0);
7772 if (bbr->r_state == TCPS_SYN_SENT) {
7773 /*
7774 * Special case on where we sent SYN. When
7775 * the SYN-ACK is processed in syn_sent
7776 * state it bumps the snd_una. This causes
7777 * us to hit here even though we did ack 1
7778 * byte.
7779 *
7780 * Go through the nothing left case so we
7781 * send data.
7782 */
7783 goto nothing_left;
7784 }
7785 }
7786 return (0);
7787 }
7788 /*
7789 * If we reach this point, ACK is not a duplicate, i.e., it ACKs
7790 * something we sent.
7791 */
7792 if (tp->t_flags & TF_NEEDSYN) {
7793 /*
7794 * T/TCP: Connection was half-synchronized, and our SYN has
7795 * been ACK'd (so connection is now fully synchronized). Go
7796 * to non-starred state, increment snd_una for ACK of SYN,
7797 * and check if we can do window scaling.
7798 */
7799 tp->t_flags &= ~TF_NEEDSYN;
7800 tp->snd_una++;
7801 /* Do window scaling? */
7802 if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
7803 (TF_RCVD_SCALE | TF_REQ_SCALE)) {
7804 tp->rcv_scale = tp->request_r_scale;
7805 /* Send window already scaled. */
7806 }
7807 }
7808 INP_WLOCK_ASSERT(tptoinpcb(tp));
7809
7810 acked = BYTES_THIS_ACK(tp, th);
7811 KMOD_TCPSTAT_ADD(tcps_rcvackpack, (int)nsegs);
7812 KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
7813
7814 /*
7815 * If we just performed our first retransmit, and the ACK arrives
7816 * within our recovery window, then it was a mistake to do the
7817 * retransmit in the first place. Recover our original cwnd and
7818 * ssthresh, and proceed to transmit where we left off.
7819 */
7820 if (tp->t_flags & TF_PREVVALID) {
7821 tp->t_flags &= ~TF_PREVVALID;
7822 if (tp->t_rxtshift == 1 &&
7823 (int)(ticks - tp->t_badrxtwin) < 0)
7824 bbr_cong_signal(tp, th, CC_RTO_ERR, NULL);
7825 }
7826 SOCK_SENDBUF_LOCK(so);
7827 acked_amount = min(acked, (int)sbavail(&so->so_snd));
7828 tp->snd_wnd -= acked_amount;
7829 mfree = sbcut_locked(&so->so_snd, acked_amount);
7830 /* NB: sowwakeup_locked() does an implicit unlock. */
7831 sowwakeup_locked(so);
7832 m_freem(mfree);
7833 if (SEQ_GT(th->th_ack, tp->snd_una)) {
7834 bbr_collapse_rtt(tp, bbr, TCP_REXMTVAL(tp));
7835 }
7836 tp->snd_una = th->th_ack;
7837 bbr_ack_received(tp, bbr, th, acked, sack_changed, prev_acked, __LINE__, (bbr->r_ctl.rc_lost - lost));
7838 if (IN_RECOVERY(tp->t_flags)) {
7839 if (SEQ_LT(th->th_ack, tp->snd_recover) &&
7840 (SEQ_LT(th->th_ack, tp->snd_max))) {
7841 tcp_bbr_partialack(tp);
7842 } else {
7843 bbr_post_recovery(tp);
7844 }
7845 }
7846 if (SEQ_GT(tp->snd_una, tp->snd_recover)) {
7847 tp->snd_recover = tp->snd_una;
7848 }
7849 if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
7850 tp->snd_nxt = tp->snd_max;
7851 }
7852 if (tp->snd_una == tp->snd_max) {
7853 /* Nothing left outstanding */
7854 nothing_left:
7855 bbr_log_progress_event(bbr, tp, ticks, PROGRESS_CLEAR, __LINE__);
7856 if (sbavail(&so->so_snd) == 0)
7857 bbr->rc_tp->t_acktime = 0;
7858 if ((sbused(&so->so_snd) == 0) &&
7859 (tp->t_flags & TF_SENTFIN)) {
7860 ourfinisacked = 1;
7861 }
7862 bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
7863 if (bbr->rc_in_persist == 0) {
7864 bbr->r_ctl.rc_went_idle_time = bbr->r_ctl.rc_rcvtime;
7865 }
7866 sack_filter_clear(&bbr->r_ctl.bbr_sf, tp->snd_una);
7867 bbr_log_ack_clear(bbr, bbr->r_ctl.rc_rcvtime);
7868 /*
7869 * We invalidate the last ack here since we
7870 * don't want to transfer forward the time
7871 * for our sum's calculations.
7872 */
7873 if ((tp->t_state >= TCPS_FIN_WAIT_1) &&
7874 (sbavail(&so->so_snd) == 0) &&
7875 (tp->t_flags2 & TF2_DROP_AF_DATA)) {
7876 /*
7877 * The socket was gone and the peer sent data, time
7878 * to reset him.
7879 */
7880 *ret_val = 1;
7881 tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
7882 /* tcp_close will kill the inp pre-log the Reset */
7883 tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
7884 tp = tcp_close(tp);
7885 ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, tlen);
7886 BBR_STAT_INC(bbr_dropped_af_data);
7887 return (1);
7888 }
7889 /* Set need output so persist might get set */
7890 bbr->r_wanted_output = 1;
7891 }
7892 if (ofia)
7893 *ofia = ourfinisacked;
7894 return (0);
7895 }
7896
7897 static void
bbr_enter_persist(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts,int32_t line)7898 bbr_enter_persist(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts, int32_t line)
7899 {
7900 if (bbr->rc_in_persist == 0) {
7901 bbr_timer_cancel(bbr, __LINE__, cts);
7902 bbr->r_ctl.rc_last_delay_val = 0;
7903 tp->t_rxtshift = 0;
7904 bbr->rc_in_persist = 1;
7905 bbr->r_ctl.rc_went_idle_time = cts;
7906 /* We should be capped when rw went to 0 but just in case */
7907 bbr_log_type_pesist(bbr, cts, 0, line, 1);
7908 /* Time freezes for the state, so do the accounting now */
7909 if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
7910 uint32_t time_in;
7911
7912 time_in = cts - bbr->r_ctl.rc_bbr_state_time;
7913 if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW) {
7914 int32_t idx;
7915
7916 idx = bbr_state_val(bbr);
7917 counter_u64_add(bbr_state_time[(idx + 5)], time_in);
7918 } else {
7919 counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
7920 }
7921 }
7922 bbr->r_ctl.rc_bbr_state_time = cts;
7923 }
7924 }
7925
7926 static void
bbr_restart_after_idle(struct tcp_bbr * bbr,uint32_t cts,uint32_t idle_time)7927 bbr_restart_after_idle(struct tcp_bbr *bbr, uint32_t cts, uint32_t idle_time)
7928 {
7929 /*
7930 * Note that if idle time does not exceed our
7931 * threshold, we do nothing continuing the state
7932 * transitions we were last walking through.
7933 */
7934 if (idle_time >= bbr_idle_restart_threshold) {
7935 if (bbr->rc_use_idle_restart) {
7936 bbr->rc_bbr_state = BBR_STATE_IDLE_EXIT;
7937 /*
7938 * Set our target using BBR_UNIT, so
7939 * we increase at a dramatic rate but
7940 * we stop when we get the pipe
7941 * full again for our current b/w estimate.
7942 */
7943 bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
7944 bbr->r_ctl.rc_bbr_cwnd_gain = BBR_UNIT;
7945 bbr_set_state_target(bbr, __LINE__);
7946 /* Now setup our gains to ramp up */
7947 bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.rc_startup_pg;
7948 bbr->r_ctl.rc_bbr_cwnd_gain = bbr->r_ctl.rc_startup_pg;
7949 bbr_log_type_statechange(bbr, cts, __LINE__);
7950 } else if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW) {
7951 bbr_substate_change(bbr, cts, __LINE__, 1);
7952 }
7953 }
7954 }
7955
7956 static void
bbr_exit_persist(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts,int32_t line)7957 bbr_exit_persist(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts, int32_t line)
7958 {
7959 uint32_t idle_time;
7960
7961 if (bbr->rc_in_persist == 0)
7962 return;
7963 idle_time = bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time);
7964 bbr->rc_in_persist = 0;
7965 bbr->rc_hit_state_1 = 0;
7966 bbr->r_ctl.rc_del_time = cts;
7967 /*
7968 * We invalidate the last ack here since we
7969 * don't want to transfer forward the time
7970 * for our sum's calculations.
7971 */
7972 if (tcp_in_hpts(bbr->rc_tp)) {
7973 tcp_hpts_remove(bbr->rc_tp);
7974 bbr->rc_timer_first = 0;
7975 bbr->r_ctl.rc_hpts_flags = 0;
7976 bbr->r_ctl.rc_last_delay_val = 0;
7977 bbr->r_ctl.rc_hptsi_agg_delay = 0;
7978 bbr->r_agg_early_set = 0;
7979 bbr->r_ctl.rc_agg_early = 0;
7980 }
7981 bbr_log_type_pesist(bbr, cts, idle_time, line, 0);
7982 if (idle_time >= bbr_rtt_probe_time) {
7983 /*
7984 * This qualifies as a RTT_PROBE session since we drop the
7985 * data outstanding to nothing and waited more than
7986 * bbr_rtt_probe_time.
7987 */
7988 bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_PERSIST, 0);
7989 bbr->r_ctl.last_in_probertt = bbr->r_ctl.rc_rtt_shrinks = cts;
7990 }
7991 tp->t_rxtshift = 0;
7992 /*
7993 * If in probeBW and we have persisted more than an RTT lets do
7994 * special handling.
7995 */
7996 /* Force a time based epoch */
7997 bbr_set_epoch(bbr, cts, __LINE__);
7998 /*
7999 * Setup the lost so we don't count anything against the guy
8000 * we have been stuck with during persists.
8001 */
8002 bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
8003 /* Time un-freezes for the state */
8004 bbr->r_ctl.rc_bbr_state_time = cts;
8005 if ((bbr->rc_bbr_state == BBR_STATE_PROBE_BW) ||
8006 (bbr->rc_bbr_state == BBR_STATE_PROBE_RTT)) {
8007 /*
8008 * If we are going back to probe-bw
8009 * or probe_rtt, we may need to possibly
8010 * do a fast restart.
8011 */
8012 bbr_restart_after_idle(bbr, cts, idle_time);
8013 }
8014 }
8015
8016 static void
bbr_collapsed_window(struct tcp_bbr * bbr)8017 bbr_collapsed_window(struct tcp_bbr *bbr)
8018 {
8019 /*
8020 * Now we must walk the
8021 * send map and divide the
8022 * ones left stranded. These
8023 * guys can't cause us to abort
8024 * the connection and are really
8025 * "unsent". However if a buggy
8026 * client actually did keep some
8027 * of the data i.e. collapsed the win
8028 * and refused to ack and then opened
8029 * the win and acked that data. We would
8030 * get into an ack war, the simplier
8031 * method then of just pretending we
8032 * did not send those segments something
8033 * won't work.
8034 */
8035 struct bbr_sendmap *rsm, *nrsm;
8036 tcp_seq max_seq;
8037 uint32_t maxseg;
8038 int can_split = 0;
8039 int fnd = 0;
8040
8041 maxseg = bbr->rc_tp->t_maxseg - bbr->rc_last_options;
8042 max_seq = bbr->rc_tp->snd_una + bbr->rc_tp->snd_wnd;
8043 bbr_log_type_rwnd_collapse(bbr, max_seq, 1, 0);
8044 TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_map, r_next) {
8045 /* Find the first seq past or at maxseq */
8046 if (rsm->r_flags & BBR_RWND_COLLAPSED)
8047 rsm->r_flags &= ~BBR_RWND_COLLAPSED;
8048 if (SEQ_GEQ(max_seq, rsm->r_start) &&
8049 SEQ_GEQ(rsm->r_end, max_seq)) {
8050 fnd = 1;
8051 break;
8052 }
8053 }
8054 bbr->rc_has_collapsed = 0;
8055 if (!fnd) {
8056 /* Nothing to do strange */
8057 return;
8058 }
8059 /*
8060 * Now can we split?
8061 *
8062 * We don't want to split if splitting
8063 * would generate too many small segments
8064 * less we let an attacker fragment our
8065 * send_map and leave us out of memory.
8066 */
8067 if ((max_seq != rsm->r_start) &&
8068 (max_seq != rsm->r_end)){
8069 /* can we split? */
8070 int res1, res2;
8071
8072 res1 = max_seq - rsm->r_start;
8073 res2 = rsm->r_end - max_seq;
8074 if ((res1 >= (maxseg/8)) &&
8075 (res2 >= (maxseg/8))) {
8076 /* No small pieces here */
8077 can_split = 1;
8078 } else if (bbr->r_ctl.rc_num_small_maps_alloced < bbr_sack_block_limit) {
8079 /* We are under the limit */
8080 can_split = 1;
8081 }
8082 }
8083 /* Ok do we need to split this rsm? */
8084 if (max_seq == rsm->r_start) {
8085 /* It's this guy no split required */
8086 nrsm = rsm;
8087 } else if (max_seq == rsm->r_end) {
8088 /* It's the next one no split required. */
8089 nrsm = TAILQ_NEXT(rsm, r_next);
8090 if (nrsm == NULL) {
8091 /* Huh? */
8092 return;
8093 }
8094 } else if (can_split && SEQ_LT(max_seq, rsm->r_end)) {
8095 /* yep we need to split it */
8096 nrsm = bbr_alloc_limit(bbr, BBR_LIMIT_TYPE_SPLIT);
8097 if (nrsm == NULL) {
8098 /* failed XXXrrs what can we do mark the whole? */
8099 nrsm = rsm;
8100 goto no_split;
8101 }
8102 /* Clone it */
8103 bbr_log_type_rwnd_collapse(bbr, max_seq, 3, 0);
8104 bbr_clone_rsm(bbr, nrsm, rsm, max_seq);
8105 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_map, rsm, nrsm, r_next);
8106 if (rsm->r_in_tmap) {
8107 TAILQ_INSERT_AFTER(&bbr->r_ctl.rc_tmap, rsm, nrsm, r_tnext);
8108 nrsm->r_in_tmap = 1;
8109 }
8110 } else {
8111 /*
8112 * Split not allowed just start here just
8113 * use this guy.
8114 */
8115 nrsm = rsm;
8116 }
8117 no_split:
8118 BBR_STAT_INC(bbr_collapsed_win);
8119 /* reuse fnd as a count */
8120 fnd = 0;
8121 TAILQ_FOREACH_FROM(nrsm, &bbr->r_ctl.rc_map, r_next) {
8122 nrsm->r_flags |= BBR_RWND_COLLAPSED;
8123 fnd++;
8124 bbr->rc_has_collapsed = 1;
8125 }
8126 bbr_log_type_rwnd_collapse(bbr, max_seq, 4, fnd);
8127 }
8128
8129 static void
bbr_un_collapse_window(struct tcp_bbr * bbr)8130 bbr_un_collapse_window(struct tcp_bbr *bbr)
8131 {
8132 struct bbr_sendmap *rsm;
8133 int cleared = 0;
8134
8135 TAILQ_FOREACH_REVERSE(rsm, &bbr->r_ctl.rc_map, bbr_head, r_next) {
8136 if (rsm->r_flags & BBR_RWND_COLLAPSED) {
8137 /* Clear the flag */
8138 rsm->r_flags &= ~BBR_RWND_COLLAPSED;
8139 cleared++;
8140 } else
8141 break;
8142 }
8143 bbr_log_type_rwnd_collapse(bbr,
8144 (bbr->rc_tp->snd_una + bbr->rc_tp->snd_wnd), 0, cleared);
8145 bbr->rc_has_collapsed = 0;
8146 }
8147
8148 /*
8149 * Return value of 1, the TCB is unlocked and most
8150 * likely gone, return value of 0, the TCB is still
8151 * locked.
8152 */
8153 static int
bbr_process_data(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt)8154 bbr_process_data(struct mbuf *m, struct tcphdr *th, struct socket *so,
8155 struct tcpcb *tp, int32_t drop_hdrlen, int32_t tlen,
8156 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt)
8157 {
8158 /*
8159 * Update window information. Don't look at window if no ACK: TAC's
8160 * send garbage on first SYN.
8161 */
8162 uint16_t nsegs;
8163 int32_t tfo_syn;
8164 struct tcp_bbr *bbr;
8165
8166 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
8167 INP_WLOCK_ASSERT(tptoinpcb(tp));
8168 nsegs = max(1, m->m_pkthdr.lro_nsegs);
8169 if ((thflags & TH_ACK) &&
8170 (SEQ_LT(tp->snd_wl1, th->th_seq) ||
8171 (tp->snd_wl1 == th->th_seq && (SEQ_LT(tp->snd_wl2, th->th_ack) ||
8172 (tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd))))) {
8173 /* keep track of pure window updates */
8174 if (tlen == 0 &&
8175 tp->snd_wl2 == th->th_ack && tiwin > tp->snd_wnd)
8176 KMOD_TCPSTAT_INC(tcps_rcvwinupd);
8177 tp->snd_wnd = tiwin;
8178 tp->snd_wl1 = th->th_seq;
8179 tp->snd_wl2 = th->th_ack;
8180 if (tp->snd_wnd > tp->max_sndwnd)
8181 tp->max_sndwnd = tp->snd_wnd;
8182 bbr->r_wanted_output = 1;
8183 } else if (thflags & TH_ACK) {
8184 if ((tp->snd_wl2 == th->th_ack) && (tiwin < tp->snd_wnd)) {
8185 tp->snd_wnd = tiwin;
8186 tp->snd_wl1 = th->th_seq;
8187 tp->snd_wl2 = th->th_ack;
8188 }
8189 }
8190 if (tp->snd_wnd < ctf_outstanding(tp))
8191 /* The peer collapsed its window on us */
8192 bbr_collapsed_window(bbr);
8193 else if (bbr->rc_has_collapsed)
8194 bbr_un_collapse_window(bbr);
8195 /* Was persist timer active and now we have window space? */
8196 if ((bbr->rc_in_persist != 0) &&
8197 (tp->snd_wnd >= min((bbr->r_ctl.rc_high_rwnd/2),
8198 bbr_minseg(bbr)))) {
8199 /*
8200 * Make the rate persist at end of persist mode if idle long
8201 * enough
8202 */
8203 bbr_exit_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
8204
8205 /* Make sure we output to start the timer */
8206 bbr->r_wanted_output = 1;
8207 }
8208 /* Do we need to enter persist? */
8209 if ((bbr->rc_in_persist == 0) &&
8210 (tp->snd_wnd < min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) &&
8211 TCPS_HAVEESTABLISHED(tp->t_state) &&
8212 (tp->snd_max == tp->snd_una) &&
8213 sbavail(&so->so_snd) &&
8214 (sbavail(&so->so_snd) > tp->snd_wnd)) {
8215 /* No send window.. we must enter persist */
8216 bbr_enter_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
8217 }
8218 if (tp->t_flags2 & TF2_DROP_AF_DATA) {
8219 m_freem(m);
8220 return (0);
8221 }
8222 /*
8223 * We don't support urgent data but
8224 * drag along the up just to make sure
8225 * if there is a stack switch no one
8226 * is surprised.
8227 */
8228 tp->rcv_up = tp->rcv_nxt;
8229
8230 /*
8231 * Process the segment text, merging it into the TCP sequencing
8232 * queue, and arranging for acknowledgment of receipt if necessary.
8233 * This process logically involves adjusting tp->rcv_wnd as data is
8234 * presented to the user (this happens in tcp_usrreq.c, case
8235 * PRU_RCVD). If a FIN has already been received on this connection
8236 * then we just ignore the text.
8237 */
8238 tfo_syn = ((tp->t_state == TCPS_SYN_RECEIVED) &&
8239 (tp->t_flags & TF_FASTOPEN));
8240 if ((tlen || (thflags & TH_FIN) || (tfo_syn && tlen > 0)) &&
8241 TCPS_HAVERCVDFIN(tp->t_state) == 0) {
8242 tcp_seq save_start = th->th_seq;
8243 tcp_seq save_rnxt = tp->rcv_nxt;
8244 int save_tlen = tlen;
8245
8246 m_adj(m, drop_hdrlen); /* delayed header drop */
8247 /*
8248 * Insert segment which includes th into TCP reassembly
8249 * queue with control block tp. Set thflags to whether
8250 * reassembly now includes a segment with FIN. This handles
8251 * the common case inline (segment is the next to be
8252 * received on an established connection, and the queue is
8253 * empty), avoiding linkage into and removal from the queue
8254 * and repetition of various conversions. Set DELACK for
8255 * segments received in order, but ack immediately when
8256 * segments are out of order (so fast retransmit can work).
8257 */
8258 if (th->th_seq == tp->rcv_nxt &&
8259 SEGQ_EMPTY(tp) &&
8260 (TCPS_HAVEESTABLISHED(tp->t_state) ||
8261 tfo_syn)) {
8262 #ifdef NETFLIX_SB_LIMITS
8263 u_int mcnt, appended;
8264
8265 if (so->so_rcv.sb_shlim) {
8266 mcnt = m_memcnt(m);
8267 appended = 0;
8268 if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
8269 CFO_NOSLEEP, NULL) == false) {
8270 counter_u64_add(tcp_sb_shlim_fails, 1);
8271 m_freem(m);
8272 return (0);
8273 }
8274 }
8275
8276 #endif
8277 if (DELAY_ACK(tp, bbr, nsegs) || tfo_syn) {
8278 bbr->bbr_segs_rcvd += max(1, nsegs);
8279 tp->t_flags |= TF_DELACK;
8280 bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
8281 } else {
8282 bbr->r_wanted_output = 1;
8283 tp->t_flags |= TF_ACKNOW;
8284 }
8285 tp->rcv_nxt += tlen;
8286 if (tlen &&
8287 ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
8288 (tp->t_fbyte_in == 0)) {
8289 tp->t_fbyte_in = ticks;
8290 if (tp->t_fbyte_in == 0)
8291 tp->t_fbyte_in = 1;
8292 if (tp->t_fbyte_out && tp->t_fbyte_in)
8293 tp->t_flags2 |= TF2_FBYTES_COMPLETE;
8294 }
8295 thflags = tcp_get_flags(th) & TH_FIN;
8296 KMOD_TCPSTAT_ADD(tcps_rcvpack, (int)nsegs);
8297 KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
8298 SOCK_RECVBUF_LOCK(so);
8299 if (so->so_rcv.sb_state & SBS_CANTRCVMORE)
8300 m_freem(m);
8301 else
8302 #ifdef NETFLIX_SB_LIMITS
8303 appended =
8304 #endif
8305 sbappendstream_locked(&so->so_rcv, m, 0);
8306 /* NB: sorwakeup_locked() does an implicit unlock. */
8307 sorwakeup_locked(so);
8308 #ifdef NETFLIX_SB_LIMITS
8309 if (so->so_rcv.sb_shlim && appended != mcnt)
8310 counter_fo_release(so->so_rcv.sb_shlim,
8311 mcnt - appended);
8312 #endif
8313
8314 } else {
8315 /*
8316 * XXX: Due to the header drop above "th" is
8317 * theoretically invalid by now. Fortunately
8318 * m_adj() doesn't actually frees any mbufs when
8319 * trimming from the head.
8320 */
8321 tcp_seq temp = save_start;
8322
8323 thflags = tcp_reass(tp, th, &temp, &tlen, m);
8324 tp->t_flags |= TF_ACKNOW;
8325 if (tp->t_flags & TF_WAKESOR) {
8326 tp->t_flags &= ~TF_WAKESOR;
8327 /* NB: sorwakeup_locked() does an implicit unlock. */
8328 sorwakeup_locked(so);
8329 }
8330 }
8331 if ((tp->t_flags & TF_SACK_PERMIT) &&
8332 (save_tlen > 0) &&
8333 TCPS_HAVEESTABLISHED(tp->t_state)) {
8334 if ((tlen == 0) && (SEQ_LT(save_start, save_rnxt))) {
8335 /*
8336 * DSACK actually handled in the fastpath
8337 * above.
8338 */
8339 tcp_update_sack_list(tp, save_start,
8340 save_start + save_tlen);
8341 } else if ((tlen > 0) && SEQ_GT(tp->rcv_nxt, save_rnxt)) {
8342 if ((tp->rcv_numsacks >= 1) &&
8343 (tp->sackblks[0].end == save_start)) {
8344 /*
8345 * Partial overlap, recorded at todrop
8346 * above.
8347 */
8348 tcp_update_sack_list(tp,
8349 tp->sackblks[0].start,
8350 tp->sackblks[0].end);
8351 } else {
8352 tcp_update_dsack_list(tp, save_start,
8353 save_start + save_tlen);
8354 }
8355 } else if (tlen >= save_tlen) {
8356 /* Update of sackblks. */
8357 tcp_update_dsack_list(tp, save_start,
8358 save_start + save_tlen);
8359 } else if (tlen > 0) {
8360 tcp_update_dsack_list(tp, save_start,
8361 save_start + tlen);
8362 }
8363 }
8364 } else {
8365 m_freem(m);
8366 thflags &= ~TH_FIN;
8367 }
8368
8369 /*
8370 * If FIN is received ACK the FIN and let the user know that the
8371 * connection is closing.
8372 */
8373 if (thflags & TH_FIN) {
8374 if (TCPS_HAVERCVDFIN(tp->t_state) == 0) {
8375 /* The socket upcall is handled by socantrcvmore. */
8376 socantrcvmore(so);
8377 /*
8378 * If connection is half-synchronized (ie NEEDSYN
8379 * flag on) then delay ACK, so it may be piggybacked
8380 * when SYN is sent. Otherwise, since we received a
8381 * FIN then no more input can be expected, send ACK
8382 * now.
8383 */
8384 if (tp->t_flags & TF_NEEDSYN) {
8385 tp->t_flags |= TF_DELACK;
8386 bbr_timer_cancel(bbr,
8387 __LINE__, bbr->r_ctl.rc_rcvtime);
8388 } else {
8389 tp->t_flags |= TF_ACKNOW;
8390 }
8391 tp->rcv_nxt++;
8392 }
8393 switch (tp->t_state) {
8394 /*
8395 * In SYN_RECEIVED and ESTABLISHED STATES enter the
8396 * CLOSE_WAIT state.
8397 */
8398 case TCPS_SYN_RECEIVED:
8399 tp->t_starttime = ticks;
8400 /* FALLTHROUGH */
8401 case TCPS_ESTABLISHED:
8402 tcp_state_change(tp, TCPS_CLOSE_WAIT);
8403 break;
8404
8405 /*
8406 * If still in FIN_WAIT_1 STATE FIN has not been
8407 * acked so enter the CLOSING state.
8408 */
8409 case TCPS_FIN_WAIT_1:
8410 tcp_state_change(tp, TCPS_CLOSING);
8411 break;
8412
8413 /*
8414 * In FIN_WAIT_2 state enter the TIME_WAIT state,
8415 * starting the time-wait timer, turning off the
8416 * other standard timers.
8417 */
8418 case TCPS_FIN_WAIT_2:
8419 bbr->rc_timer_first = 1;
8420 bbr_timer_cancel(bbr,
8421 __LINE__, bbr->r_ctl.rc_rcvtime);
8422 tcp_twstart(tp);
8423 return (1);
8424 }
8425 }
8426 /*
8427 * Return any desired output.
8428 */
8429 if ((tp->t_flags & TF_ACKNOW) ||
8430 (sbavail(&so->so_snd) > ctf_outstanding(tp))) {
8431 bbr->r_wanted_output = 1;
8432 }
8433 return (0);
8434 }
8435
8436 /*
8437 * Here nothing is really faster, its just that we
8438 * have broken out the fast-data path also just like
8439 * the fast-ack. Return 1 if we processed the packet
8440 * return 0 if you need to take the "slow-path".
8441 */
8442 static int
bbr_do_fastnewdata(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t nxt_pkt)8443 bbr_do_fastnewdata(struct mbuf *m, struct tcphdr *th, struct socket *so,
8444 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
8445 uint32_t tiwin, int32_t nxt_pkt)
8446 {
8447 uint16_t nsegs;
8448 int32_t newsize = 0; /* automatic sockbuf scaling */
8449 struct tcp_bbr *bbr;
8450 #ifdef NETFLIX_SB_LIMITS
8451 u_int mcnt, appended;
8452 #endif
8453
8454 /* On the hpts and we would have called output */
8455 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
8456
8457 /*
8458 * If last ACK falls within this segment's sequence numbers, record
8459 * the timestamp. NOTE that the test is modified according to the
8460 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
8461 */
8462 if (bbr->r_ctl.rc_resend != NULL) {
8463 return (0);
8464 }
8465 if (tiwin && tiwin != tp->snd_wnd) {
8466 return (0);
8467 }
8468 if (__predict_false((tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN)))) {
8469 return (0);
8470 }
8471 if (__predict_false((to->to_flags & TOF_TS) &&
8472 (TSTMP_LT(to->to_tsval, tp->ts_recent)))) {
8473 return (0);
8474 }
8475 if (__predict_false((th->th_ack != tp->snd_una))) {
8476 return (0);
8477 }
8478 if (__predict_false(tlen > sbspace(&so->so_rcv))) {
8479 return (0);
8480 }
8481 if ((to->to_flags & TOF_TS) != 0 &&
8482 SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
8483 tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
8484 tp->ts_recent = to->to_tsval;
8485 }
8486 /*
8487 * This is a pure, in-sequence data packet with nothing on the
8488 * reassembly queue and we have enough buffer space to take it.
8489 */
8490 nsegs = max(1, m->m_pkthdr.lro_nsegs);
8491
8492 #ifdef NETFLIX_SB_LIMITS
8493 if (so->so_rcv.sb_shlim) {
8494 mcnt = m_memcnt(m);
8495 appended = 0;
8496 if (counter_fo_get(so->so_rcv.sb_shlim, mcnt,
8497 CFO_NOSLEEP, NULL) == false) {
8498 counter_u64_add(tcp_sb_shlim_fails, 1);
8499 m_freem(m);
8500 return (1);
8501 }
8502 }
8503 #endif
8504 /* Clean receiver SACK report if present */
8505 if (tp->rcv_numsacks)
8506 tcp_clean_sackreport(tp);
8507 KMOD_TCPSTAT_INC(tcps_preddat);
8508 tp->rcv_nxt += tlen;
8509 if (tlen &&
8510 ((tp->t_flags2 & TF2_FBYTES_COMPLETE) == 0) &&
8511 (tp->t_fbyte_in == 0)) {
8512 tp->t_fbyte_in = ticks;
8513 if (tp->t_fbyte_in == 0)
8514 tp->t_fbyte_in = 1;
8515 if (tp->t_fbyte_out && tp->t_fbyte_in)
8516 tp->t_flags2 |= TF2_FBYTES_COMPLETE;
8517 }
8518 /*
8519 * Pull snd_wl1 up to prevent seq wrap relative to th_seq.
8520 */
8521 tp->snd_wl1 = th->th_seq;
8522 /*
8523 * Pull rcv_up up to prevent seq wrap relative to rcv_nxt.
8524 */
8525 tp->rcv_up = tp->rcv_nxt;
8526 KMOD_TCPSTAT_ADD(tcps_rcvpack, (int)nsegs);
8527 KMOD_TCPSTAT_ADD(tcps_rcvbyte, tlen);
8528 newsize = tcp_autorcvbuf(m, th, so, tp, tlen);
8529
8530 /* Add data to socket buffer. */
8531 SOCK_RECVBUF_LOCK(so);
8532 if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
8533 m_freem(m);
8534 } else {
8535 /*
8536 * Set new socket buffer size. Give up when limit is
8537 * reached.
8538 */
8539 if (newsize)
8540 if (!sbreserve_locked(so, SO_RCV, newsize, NULL))
8541 so->so_rcv.sb_flags &= ~SB_AUTOSIZE;
8542 m_adj(m, drop_hdrlen); /* delayed header drop */
8543
8544 #ifdef NETFLIX_SB_LIMITS
8545 appended =
8546 #endif
8547 sbappendstream_locked(&so->so_rcv, m, 0);
8548 ctf_calc_rwin(so, tp);
8549 }
8550 /* NB: sorwakeup_locked() does an implicit unlock. */
8551 sorwakeup_locked(so);
8552 #ifdef NETFLIX_SB_LIMITS
8553 if (so->so_rcv.sb_shlim && mcnt != appended)
8554 counter_fo_release(so->so_rcv.sb_shlim, mcnt - appended);
8555 #endif
8556 if (DELAY_ACK(tp, bbr, nsegs)) {
8557 bbr->bbr_segs_rcvd += max(1, nsegs);
8558 tp->t_flags |= TF_DELACK;
8559 bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
8560 } else {
8561 bbr->r_wanted_output = 1;
8562 tp->t_flags |= TF_ACKNOW;
8563 }
8564 return (1);
8565 }
8566
8567 /*
8568 * This subfunction is used to try to highly optimize the
8569 * fast path. We again allow window updates that are
8570 * in sequence to remain in the fast-path. We also add
8571 * in the __predict's to attempt to help the compiler.
8572 * Note that if we return a 0, then we can *not* process
8573 * it and the caller should push the packet into the
8574 * slow-path. If we return 1, then all is well and
8575 * the packet is fully processed.
8576 */
8577 static int
bbr_fastack(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t nxt_pkt,uint8_t iptos)8578 bbr_fastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
8579 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
8580 uint32_t tiwin, int32_t nxt_pkt, uint8_t iptos)
8581 {
8582 int32_t acked;
8583 uint16_t nsegs;
8584 uint32_t sack_changed;
8585 uint32_t prev_acked = 0;
8586 struct tcp_bbr *bbr;
8587
8588 if (__predict_false(SEQ_LEQ(th->th_ack, tp->snd_una))) {
8589 /* Old ack, behind (or duplicate to) the last one rcv'd */
8590 return (0);
8591 }
8592 if (__predict_false(SEQ_GT(th->th_ack, tp->snd_max))) {
8593 /* Above what we have sent? */
8594 return (0);
8595 }
8596 if (__predict_false(tiwin == 0)) {
8597 /* zero window */
8598 return (0);
8599 }
8600 if (__predict_false(tp->t_flags & (TF_NEEDSYN | TF_NEEDFIN))) {
8601 /* We need a SYN or a FIN, unlikely.. */
8602 return (0);
8603 }
8604 if ((to->to_flags & TOF_TS) && __predict_false(TSTMP_LT(to->to_tsval, tp->ts_recent))) {
8605 /* Timestamp is behind .. old ack with seq wrap? */
8606 return (0);
8607 }
8608 if (__predict_false(IN_RECOVERY(tp->t_flags))) {
8609 /* Still recovering */
8610 return (0);
8611 }
8612 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
8613 if (__predict_false(bbr->r_ctl.rc_resend != NULL)) {
8614 /* We are retransmitting */
8615 return (0);
8616 }
8617 if (__predict_false(bbr->rc_in_persist != 0)) {
8618 /* In persist mode */
8619 return (0);
8620 }
8621 if (bbr->r_ctl.rc_sacked) {
8622 /* We have sack holes on our scoreboard */
8623 return (0);
8624 }
8625 /* Ok if we reach here, we can process a fast-ack */
8626 nsegs = max(1, m->m_pkthdr.lro_nsegs);
8627 sack_changed = bbr_log_ack(tp, to, th, &prev_acked);
8628 /*
8629 * We never detect loss in fast ack [we can't
8630 * have a sack and can't be in recovery so
8631 * we always pass 0 (nothing detected)].
8632 */
8633 bbr_lt_bw_sampling(bbr, bbr->r_ctl.rc_rcvtime, 0);
8634 /* Did the window get updated? */
8635 if (tiwin != tp->snd_wnd) {
8636 tp->snd_wnd = tiwin;
8637 tp->snd_wl1 = th->th_seq;
8638 if (tp->snd_wnd > tp->max_sndwnd)
8639 tp->max_sndwnd = tp->snd_wnd;
8640 }
8641 /* Do we need to exit persists? */
8642 if ((bbr->rc_in_persist != 0) &&
8643 (tp->snd_wnd >= min((bbr->r_ctl.rc_high_rwnd/2),
8644 bbr_minseg(bbr)))) {
8645 bbr_exit_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
8646 bbr->r_wanted_output = 1;
8647 }
8648 /* Do we need to enter persists? */
8649 if ((bbr->rc_in_persist == 0) &&
8650 (tp->snd_wnd < min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) &&
8651 TCPS_HAVEESTABLISHED(tp->t_state) &&
8652 (tp->snd_max == tp->snd_una) &&
8653 sbavail(&so->so_snd) &&
8654 (sbavail(&so->so_snd) > tp->snd_wnd)) {
8655 /* No send window.. we must enter persist */
8656 bbr_enter_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
8657 }
8658 /*
8659 * If last ACK falls within this segment's sequence numbers, record
8660 * the timestamp. NOTE that the test is modified according to the
8661 * latest proposal of the tcplw@cray.com list (Braden 1993/04/26).
8662 */
8663 if ((to->to_flags & TOF_TS) != 0 &&
8664 SEQ_LEQ(th->th_seq, tp->last_ack_sent)) {
8665 tp->ts_recent_age = bbr->r_ctl.rc_rcvtime;
8666 tp->ts_recent = to->to_tsval;
8667 }
8668 /*
8669 * This is a pure ack for outstanding data.
8670 */
8671 KMOD_TCPSTAT_INC(tcps_predack);
8672
8673 /*
8674 * "bad retransmit" recovery.
8675 */
8676 if (tp->t_flags & TF_PREVVALID) {
8677 tp->t_flags &= ~TF_PREVVALID;
8678 if (tp->t_rxtshift == 1 &&
8679 (int)(ticks - tp->t_badrxtwin) < 0)
8680 bbr_cong_signal(tp, th, CC_RTO_ERR, NULL);
8681 }
8682 /*
8683 * Recalculate the transmit timer / rtt.
8684 *
8685 * Some boxes send broken timestamp replies during the SYN+ACK
8686 * phase, ignore timestamps of 0 or we could calculate a huge RTT
8687 * and blow up the retransmit timer.
8688 */
8689 acked = BYTES_THIS_ACK(tp, th);
8690
8691 #ifdef TCP_HHOOK
8692 /* Run HHOOK_TCP_ESTABLISHED_IN helper hooks. */
8693 hhook_run_tcp_est_in(tp, th, to);
8694 #endif
8695
8696 KMOD_TCPSTAT_ADD(tcps_rcvackpack, (int)nsegs);
8697 KMOD_TCPSTAT_ADD(tcps_rcvackbyte, acked);
8698 sbdrop(&so->so_snd, acked);
8699
8700 if (SEQ_GT(th->th_ack, tp->snd_una))
8701 bbr_collapse_rtt(tp, bbr, TCP_REXMTVAL(tp));
8702 tp->snd_una = th->th_ack;
8703 if (tp->snd_wnd < ctf_outstanding(tp))
8704 /* The peer collapsed its window on us */
8705 bbr_collapsed_window(bbr);
8706 else if (bbr->rc_has_collapsed)
8707 bbr_un_collapse_window(bbr);
8708
8709 if (SEQ_GT(tp->snd_una, tp->snd_recover)) {
8710 tp->snd_recover = tp->snd_una;
8711 }
8712 bbr_ack_received(tp, bbr, th, acked, sack_changed, prev_acked, __LINE__, 0);
8713 /*
8714 * Pull snd_wl2 up to prevent seq wrap relative to th_ack.
8715 */
8716 tp->snd_wl2 = th->th_ack;
8717 m_freem(m);
8718 /*
8719 * If all outstanding data are acked, stop retransmit timer,
8720 * otherwise restart timer using current (possibly backed-off)
8721 * value. If process is waiting for space, wakeup/selwakeup/signal.
8722 * If data are ready to send, let tcp_output decide between more
8723 * output or persist.
8724 * Wake up the socket if we have room to write more.
8725 */
8726 sowwakeup(so);
8727 if (tp->snd_una == tp->snd_max) {
8728 /* Nothing left outstanding */
8729 bbr_log_progress_event(bbr, tp, ticks, PROGRESS_CLEAR, __LINE__);
8730 if (sbavail(&so->so_snd) == 0)
8731 bbr->rc_tp->t_acktime = 0;
8732 bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
8733 if (bbr->rc_in_persist == 0) {
8734 bbr->r_ctl.rc_went_idle_time = bbr->r_ctl.rc_rcvtime;
8735 }
8736 sack_filter_clear(&bbr->r_ctl.bbr_sf, tp->snd_una);
8737 bbr_log_ack_clear(bbr, bbr->r_ctl.rc_rcvtime);
8738 /*
8739 * We invalidate the last ack here since we
8740 * don't want to transfer forward the time
8741 * for our sum's calculations.
8742 */
8743 bbr->r_wanted_output = 1;
8744 }
8745 if (sbavail(&so->so_snd)) {
8746 bbr->r_wanted_output = 1;
8747 }
8748 return (1);
8749 }
8750
8751 /*
8752 * Return value of 1, the TCB is unlocked and most
8753 * likely gone, return value of 0, the TCB is still
8754 * locked.
8755 */
8756 static int
bbr_do_syn_sent(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)8757 bbr_do_syn_sent(struct mbuf *m, struct tcphdr *th, struct socket *so,
8758 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
8759 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
8760 {
8761 int32_t todrop;
8762 int32_t ourfinisacked = 0;
8763 struct tcp_bbr *bbr;
8764 int32_t ret_val = 0;
8765
8766 INP_WLOCK_ASSERT(tptoinpcb(tp));
8767
8768 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
8769 ctf_calc_rwin(so, tp);
8770 /*
8771 * If the state is SYN_SENT: if seg contains an ACK, but not for our
8772 * SYN, drop the input. if seg contains a RST, then drop the
8773 * connection. if seg does not contain SYN, then drop it. Otherwise
8774 * this is an acceptable SYN segment initialize tp->rcv_nxt and
8775 * tp->irs if seg contains ack then advance tp->snd_una. BRR does
8776 * not support ECN so we will not say we are capable. if SYN has
8777 * been acked change to ESTABLISHED else SYN_RCVD state arrange for
8778 * segment to be acked (eventually) continue processing rest of
8779 * data/controls, beginning with URG
8780 */
8781 if ((thflags & TH_ACK) &&
8782 (SEQ_LEQ(th->th_ack, tp->iss) ||
8783 SEQ_GT(th->th_ack, tp->snd_max))) {
8784 tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
8785 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
8786 return (1);
8787 }
8788 if ((thflags & (TH_ACK | TH_RST)) == (TH_ACK | TH_RST)) {
8789 TCP_PROBE5(connect__refused, NULL, tp,
8790 mtod(m, const char *), tp, th);
8791 tp = tcp_drop(tp, ECONNREFUSED);
8792 ctf_do_drop(m, tp);
8793 return (1);
8794 }
8795 if (thflags & TH_RST) {
8796 ctf_do_drop(m, tp);
8797 return (1);
8798 }
8799 if (!(thflags & TH_SYN)) {
8800 ctf_do_drop(m, tp);
8801 return (1);
8802 }
8803 tp->irs = th->th_seq;
8804 tcp_rcvseqinit(tp);
8805 if (thflags & TH_ACK) {
8806 int tfo_partial = 0;
8807
8808 KMOD_TCPSTAT_INC(tcps_connects);
8809 soisconnected(so);
8810 #ifdef MAC
8811 mac_socketpeer_set_from_mbuf(m, so);
8812 #endif
8813 /* Do window scaling on this connection? */
8814 if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
8815 (TF_RCVD_SCALE | TF_REQ_SCALE)) {
8816 tp->rcv_scale = tp->request_r_scale;
8817 }
8818 tp->rcv_adv += min(tp->rcv_wnd,
8819 TCP_MAXWIN << tp->rcv_scale);
8820 /*
8821 * If not all the data that was sent in the TFO SYN
8822 * has been acked, resend the remainder right away.
8823 */
8824 if ((tp->t_flags & TF_FASTOPEN) &&
8825 (tp->snd_una != tp->snd_max)) {
8826 tp->snd_nxt = th->th_ack;
8827 tfo_partial = 1;
8828 }
8829 /*
8830 * If there's data, delay ACK; if there's also a FIN ACKNOW
8831 * will be turned on later.
8832 */
8833 if (DELAY_ACK(tp, bbr, 1) && tlen != 0 && !tfo_partial) {
8834 bbr->bbr_segs_rcvd += 1;
8835 tp->t_flags |= TF_DELACK;
8836 bbr_timer_cancel(bbr, __LINE__, bbr->r_ctl.rc_rcvtime);
8837 } else {
8838 bbr->r_wanted_output = 1;
8839 tp->t_flags |= TF_ACKNOW;
8840 }
8841 if (SEQ_GT(th->th_ack, tp->iss)) {
8842 /*
8843 * The SYN is acked
8844 * handle it specially.
8845 */
8846 bbr_log_syn(tp, to);
8847 }
8848 if (SEQ_GT(th->th_ack, tp->snd_una)) {
8849 /*
8850 * We advance snd_una for the
8851 * fast open case. If th_ack is
8852 * acknowledging data beyond
8853 * snd_una we can't just call
8854 * ack-processing since the
8855 * data stream in our send-map
8856 * will start at snd_una + 1 (one
8857 * beyond the SYN). If its just
8858 * equal we don't need to do that
8859 * and there is no send_map.
8860 */
8861 tp->snd_una++;
8862 }
8863 /*
8864 * Received <SYN,ACK> in SYN_SENT[*] state. Transitions:
8865 * SYN_SENT --> ESTABLISHED SYN_SENT* --> FIN_WAIT_1
8866 */
8867 tp->t_starttime = ticks;
8868 if (tp->t_flags & TF_NEEDFIN) {
8869 tcp_state_change(tp, TCPS_FIN_WAIT_1);
8870 tp->t_flags &= ~TF_NEEDFIN;
8871 thflags &= ~TH_SYN;
8872 } else {
8873 tcp_state_change(tp, TCPS_ESTABLISHED);
8874 TCP_PROBE5(connect__established, NULL, tp,
8875 mtod(m, const char *), tp, th);
8876 cc_conn_init(tp);
8877 }
8878 } else {
8879 /*
8880 * Received initial SYN in SYN-SENT[*] state => simultaneous
8881 * open. If segment contains CC option and there is a
8882 * cached CC, apply TAO test. If it succeeds, connection is *
8883 * half-synchronized. Otherwise, do 3-way handshake:
8884 * SYN-SENT -> SYN-RECEIVED SYN-SENT* -> SYN-RECEIVED* If
8885 * there was no CC option, clear cached CC value.
8886 */
8887 tp->t_flags |= (TF_ACKNOW | TF_NEEDSYN | TF_SONOTCONN);
8888 tcp_state_change(tp, TCPS_SYN_RECEIVED);
8889 }
8890 /*
8891 * Advance th->th_seq to correspond to first data byte. If data,
8892 * trim to stay within window, dropping FIN if necessary.
8893 */
8894 th->th_seq++;
8895 if (tlen > tp->rcv_wnd) {
8896 todrop = tlen - tp->rcv_wnd;
8897 m_adj(m, -todrop);
8898 tlen = tp->rcv_wnd;
8899 thflags &= ~TH_FIN;
8900 KMOD_TCPSTAT_INC(tcps_rcvpackafterwin);
8901 KMOD_TCPSTAT_ADD(tcps_rcvbyteafterwin, todrop);
8902 }
8903 tp->snd_wl1 = th->th_seq - 1;
8904 tp->rcv_up = th->th_seq;
8905 /*
8906 * Client side of transaction: already sent SYN and data. If the
8907 * remote host used T/TCP to validate the SYN, our data will be
8908 * ACK'd; if so, enter normal data segment processing in the middle
8909 * of step 5, ack processing. Otherwise, goto step 6.
8910 */
8911 if (thflags & TH_ACK) {
8912 if ((to->to_flags & TOF_TS) != 0) {
8913 uint32_t t, rtt;
8914
8915 t = tcp_tv_to_mssectick(&bbr->rc_tv);
8916 if (TSTMP_GEQ(t, to->to_tsecr)) {
8917 rtt = t - to->to_tsecr;
8918 if (rtt == 0) {
8919 rtt = 1;
8920 }
8921 rtt *= MS_IN_USEC;
8922 tcp_bbr_xmit_timer(bbr, rtt, 0, 0, 0);
8923 apply_filter_min_small(&bbr->r_ctl.rc_rttprop,
8924 rtt, bbr->r_ctl.rc_rcvtime);
8925 }
8926 }
8927 if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val))
8928 return (ret_val);
8929 /* We may have changed to FIN_WAIT_1 above */
8930 if (tp->t_state == TCPS_FIN_WAIT_1) {
8931 /*
8932 * In FIN_WAIT_1 STATE in addition to the processing
8933 * for the ESTABLISHED state if our FIN is now
8934 * acknowledged then enter FIN_WAIT_2.
8935 */
8936 if (ourfinisacked) {
8937 /*
8938 * If we can't receive any more data, then
8939 * closing user can proceed. Starting the
8940 * timer is contrary to the specification,
8941 * but if we don't get a FIN we'll hang
8942 * forever.
8943 *
8944 * XXXjl: we should release the tp also, and
8945 * use a compressed state.
8946 */
8947 if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
8948 soisdisconnected(so);
8949 tcp_timer_activate(tp, TT_2MSL,
8950 (tcp_fast_finwait2_recycle ?
8951 tcp_finwait2_timeout :
8952 TP_MAXIDLE(tp)));
8953 }
8954 tcp_state_change(tp, TCPS_FIN_WAIT_2);
8955 }
8956 }
8957 }
8958 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
8959 tiwin, thflags, nxt_pkt));
8960 }
8961
8962 /*
8963 * Return value of 1, the TCB is unlocked and most
8964 * likely gone, return value of 0, the TCB is still
8965 * locked.
8966 */
8967 static int
bbr_do_syn_recv(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)8968 bbr_do_syn_recv(struct mbuf *m, struct tcphdr *th, struct socket *so,
8969 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
8970 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
8971 {
8972 int32_t ourfinisacked = 0;
8973 int32_t ret_val;
8974 struct tcp_bbr *bbr;
8975
8976 INP_WLOCK_ASSERT(tptoinpcb(tp));
8977
8978 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
8979 ctf_calc_rwin(so, tp);
8980 if ((thflags & TH_RST) ||
8981 (tp->t_fin_is_rst && (thflags & TH_FIN)))
8982 return (ctf_process_rst(m, th, so, tp));
8983 if ((thflags & TH_ACK) &&
8984 (SEQ_LEQ(th->th_ack, tp->snd_una) ||
8985 SEQ_GT(th->th_ack, tp->snd_max))) {
8986 tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
8987 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
8988 return (1);
8989 }
8990 if (tp->t_flags & TF_FASTOPEN) {
8991 /*
8992 * When a TFO connection is in SYN_RECEIVED, the only valid
8993 * packets are the initial SYN, a retransmit/copy of the
8994 * initial SYN (possibly with a subset of the original
8995 * data), a valid ACK, a FIN, or a RST.
8996 */
8997 if ((thflags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) {
8998 tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
8999 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
9000 return (1);
9001 } else if (thflags & TH_SYN) {
9002 /* non-initial SYN is ignored */
9003 if ((bbr->r_ctl.rc_hpts_flags & PACE_TMR_RXT) ||
9004 (bbr->r_ctl.rc_hpts_flags & PACE_TMR_TLP) ||
9005 (bbr->r_ctl.rc_hpts_flags & PACE_TMR_RACK)) {
9006 ctf_do_drop(m, NULL);
9007 return (0);
9008 }
9009 } else if (!(thflags & (TH_ACK | TH_FIN | TH_RST))) {
9010 ctf_do_drop(m, NULL);
9011 return (0);
9012 }
9013 }
9014 /*
9015 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9016 * it's less than ts_recent, drop it.
9017 */
9018 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9019 TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9020 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9021 return (ret_val);
9022 }
9023 /*
9024 * In the SYN-RECEIVED state, validate that the packet belongs to
9025 * this connection before trimming the data to fit the receive
9026 * window. Check the sequence number versus IRS since we know the
9027 * sequence numbers haven't wrapped. This is a partial fix for the
9028 * "LAND" DoS attack.
9029 */
9030 if (SEQ_LT(th->th_seq, tp->irs)) {
9031 tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
9032 ctf_do_dropwithreset(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
9033 return (1);
9034 }
9035 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9036 return (ret_val);
9037 }
9038 /*
9039 * If last ACK falls within this segment's sequence numbers, record
9040 * its timestamp. NOTE: 1) That the test incorporates suggestions
9041 * from the latest proposal of the tcplw@cray.com list (Braden
9042 * 1993/04/26). 2) That updating only on newer timestamps interferes
9043 * with our earlier PAWS tests, so this check should be solely
9044 * predicated on the sequence space of this segment. 3) That we
9045 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9046 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9047 * SEG.Len, This modified check allows us to overcome RFC1323's
9048 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9049 * p.869. In such cases, we can still calculate the RTT correctly
9050 * when RCV.NXT == Last.ACK.Sent.
9051 */
9052 if ((to->to_flags & TOF_TS) != 0 &&
9053 SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9054 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9055 ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9056 tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
9057 tp->ts_recent = to->to_tsval;
9058 }
9059 tp->snd_wnd = tiwin;
9060 /*
9061 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
9062 * is on (half-synchronized state), then queue data for later
9063 * processing; else drop segment and return.
9064 */
9065 if ((thflags & TH_ACK) == 0) {
9066 if (tp->t_flags & TF_FASTOPEN) {
9067 cc_conn_init(tp);
9068 }
9069 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9070 tiwin, thflags, nxt_pkt));
9071 }
9072 KMOD_TCPSTAT_INC(tcps_connects);
9073 if (tp->t_flags & TF_SONOTCONN) {
9074 tp->t_flags &= ~TF_SONOTCONN;
9075 soisconnected(so);
9076 }
9077 /* Do window scaling? */
9078 if ((tp->t_flags & (TF_RCVD_SCALE | TF_REQ_SCALE)) ==
9079 (TF_RCVD_SCALE | TF_REQ_SCALE)) {
9080 tp->rcv_scale = tp->request_r_scale;
9081 }
9082 /*
9083 * ok for the first time in lets see if we can use the ts to figure
9084 * out what the initial RTT was.
9085 */
9086 if ((to->to_flags & TOF_TS) != 0) {
9087 uint32_t t, rtt;
9088
9089 t = tcp_tv_to_mssectick(&bbr->rc_tv);
9090 if (TSTMP_GEQ(t, to->to_tsecr)) {
9091 rtt = t - to->to_tsecr;
9092 if (rtt == 0) {
9093 rtt = 1;
9094 }
9095 rtt *= MS_IN_USEC;
9096 tcp_bbr_xmit_timer(bbr, rtt, 0, 0, 0);
9097 apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, bbr->r_ctl.rc_rcvtime);
9098 }
9099 }
9100 /* Drop off any SYN in the send map (probably not there) */
9101 if (thflags & TH_ACK)
9102 bbr_log_syn(tp, to);
9103 if ((tp->t_flags & TF_FASTOPEN) && tp->t_tfo_pending) {
9104 tcp_fastopen_decrement_counter(tp->t_tfo_pending);
9105 tp->t_tfo_pending = NULL;
9106 }
9107 /*
9108 * Make transitions: SYN-RECEIVED -> ESTABLISHED SYN-RECEIVED* ->
9109 * FIN-WAIT-1
9110 */
9111 tp->t_starttime = ticks;
9112 if (tp->t_flags & TF_NEEDFIN) {
9113 tcp_state_change(tp, TCPS_FIN_WAIT_1);
9114 tp->t_flags &= ~TF_NEEDFIN;
9115 } else {
9116 tcp_state_change(tp, TCPS_ESTABLISHED);
9117 TCP_PROBE5(accept__established, NULL, tp,
9118 mtod(m, const char *), tp, th);
9119 /*
9120 * TFO connections call cc_conn_init() during SYN
9121 * processing. Calling it again here for such connections
9122 * is not harmless as it would undo the snd_cwnd reduction
9123 * that occurs when a TFO SYN|ACK is retransmitted.
9124 */
9125 if (!(tp->t_flags & TF_FASTOPEN))
9126 cc_conn_init(tp);
9127 }
9128 /*
9129 * Account for the ACK of our SYN prior to
9130 * regular ACK processing below, except for
9131 * simultaneous SYN, which is handled later.
9132 */
9133 if (SEQ_GT(th->th_ack, tp->snd_una) && !(tp->t_flags & TF_NEEDSYN))
9134 tp->snd_una++;
9135 /*
9136 * If segment contains data or ACK, will call tcp_reass() later; if
9137 * not, do so now to pass queued data to user.
9138 */
9139 if (tlen == 0 && (thflags & TH_FIN) == 0) {
9140 (void)tcp_reass(tp, (struct tcphdr *)0, NULL, 0,
9141 (struct mbuf *)0);
9142 if (tp->t_flags & TF_WAKESOR) {
9143 tp->t_flags &= ~TF_WAKESOR;
9144 /* NB: sorwakeup_locked() does an implicit unlock. */
9145 sorwakeup_locked(so);
9146 }
9147 }
9148 tp->snd_wl1 = th->th_seq - 1;
9149 if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
9150 return (ret_val);
9151 }
9152 if (tp->t_state == TCPS_FIN_WAIT_1) {
9153 /* We could have went to FIN_WAIT_1 (or EST) above */
9154 /*
9155 * In FIN_WAIT_1 STATE in addition to the processing for the
9156 * ESTABLISHED state if our FIN is now acknowledged then
9157 * enter FIN_WAIT_2.
9158 */
9159 if (ourfinisacked) {
9160 /*
9161 * If we can't receive any more data, then closing
9162 * user can proceed. Starting the timer is contrary
9163 * to the specification, but if we don't get a FIN
9164 * we'll hang forever.
9165 *
9166 * XXXjl: we should release the tp also, and use a
9167 * compressed state.
9168 */
9169 if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
9170 soisdisconnected(so);
9171 tcp_timer_activate(tp, TT_2MSL,
9172 (tcp_fast_finwait2_recycle ?
9173 tcp_finwait2_timeout :
9174 TP_MAXIDLE(tp)));
9175 }
9176 tcp_state_change(tp, TCPS_FIN_WAIT_2);
9177 }
9178 }
9179 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9180 tiwin, thflags, nxt_pkt));
9181 }
9182
9183 /*
9184 * Return value of 1, the TCB is unlocked and most
9185 * likely gone, return value of 0, the TCB is still
9186 * locked.
9187 */
9188 static int
bbr_do_established(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)9189 bbr_do_established(struct mbuf *m, struct tcphdr *th, struct socket *so,
9190 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9191 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9192 {
9193 struct tcp_bbr *bbr;
9194 int32_t ret_val;
9195
9196 INP_WLOCK_ASSERT(tptoinpcb(tp));
9197
9198 /*
9199 * Header prediction: check for the two common cases of a
9200 * uni-directional data xfer. If the packet has no control flags,
9201 * is in-sequence, the window didn't change and we're not
9202 * retransmitting, it's a candidate. If the length is zero and the
9203 * ack moved forward, we're the sender side of the xfer. Just free
9204 * the data acked & wake any higher level process that was blocked
9205 * waiting for space. If the length is non-zero and the ack didn't
9206 * move, we're the receiver side. If we're getting packets in-order
9207 * (the reassembly queue is empty), add the data toc The socket
9208 * buffer and note that we need a delayed ack. Make sure that the
9209 * hidden state-flags are also off. Since we check for
9210 * TCPS_ESTABLISHED first, it can only be TH_NEEDSYN.
9211 */
9212 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9213 if (bbr->r_ctl.rc_delivered < (4 * tp->t_maxseg)) {
9214 /*
9215 * If we have delived under 4 segments increase the initial
9216 * window if raised by the peer. We use this to determine
9217 * dynamic and static rwnd's at the end of a connection.
9218 */
9219 bbr->r_ctl.rc_init_rwnd = max(tiwin, tp->snd_wnd);
9220 }
9221 if (__predict_true(((to->to_flags & TOF_SACK) == 0)) &&
9222 __predict_true((thflags & (TH_SYN | TH_FIN | TH_RST | TH_URG | TH_ACK)) == TH_ACK) &&
9223 __predict_true(SEGQ_EMPTY(tp)) &&
9224 __predict_true(th->th_seq == tp->rcv_nxt)) {
9225 if (tlen == 0) {
9226 if (bbr_fastack(m, th, so, tp, to, drop_hdrlen, tlen,
9227 tiwin, nxt_pkt, iptos)) {
9228 return (0);
9229 }
9230 } else {
9231 if (bbr_do_fastnewdata(m, th, so, tp, to, drop_hdrlen, tlen,
9232 tiwin, nxt_pkt)) {
9233 return (0);
9234 }
9235 }
9236 }
9237 ctf_calc_rwin(so, tp);
9238
9239 if ((thflags & TH_RST) ||
9240 (tp->t_fin_is_rst && (thflags & TH_FIN)))
9241 return (ctf_process_rst(m, th, so, tp));
9242 /*
9243 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
9244 * synchronized state.
9245 */
9246 if (thflags & TH_SYN) {
9247 ctf_challenge_ack(m, th, tp, iptos, &ret_val);
9248 return (ret_val);
9249 }
9250 /*
9251 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9252 * it's less than ts_recent, drop it.
9253 */
9254 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9255 TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9256 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9257 return (ret_val);
9258 }
9259 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9260 return (ret_val);
9261 }
9262 /*
9263 * If last ACK falls within this segment's sequence numbers, record
9264 * its timestamp. NOTE: 1) That the test incorporates suggestions
9265 * from the latest proposal of the tcplw@cray.com list (Braden
9266 * 1993/04/26). 2) That updating only on newer timestamps interferes
9267 * with our earlier PAWS tests, so this check should be solely
9268 * predicated on the sequence space of this segment. 3) That we
9269 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9270 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9271 * SEG.Len, This modified check allows us to overcome RFC1323's
9272 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9273 * p.869. In such cases, we can still calculate the RTT correctly
9274 * when RCV.NXT == Last.ACK.Sent.
9275 */
9276 if ((to->to_flags & TOF_TS) != 0 &&
9277 SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9278 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9279 ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9280 tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
9281 tp->ts_recent = to->to_tsval;
9282 }
9283 /*
9284 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
9285 * is on (half-synchronized state), then queue data for later
9286 * processing; else drop segment and return.
9287 */
9288 if ((thflags & TH_ACK) == 0) {
9289 if (tp->t_flags & TF_NEEDSYN) {
9290 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9291 tiwin, thflags, nxt_pkt));
9292 } else if (tp->t_flags & TF_ACKNOW) {
9293 ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
9294 bbr->r_wanted_output = 1;
9295 return (ret_val);
9296 } else {
9297 ctf_do_drop(m, NULL);
9298 return (0);
9299 }
9300 }
9301 /*
9302 * Ack processing.
9303 */
9304 if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
9305 return (ret_val);
9306 }
9307 if (sbavail(&so->so_snd)) {
9308 if (ctf_progress_timeout_check(tp, true)) {
9309 bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
9310 ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
9311 return (1);
9312 }
9313 }
9314 /* State changes only happen in bbr_process_data() */
9315 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9316 tiwin, thflags, nxt_pkt));
9317 }
9318
9319 /*
9320 * Return value of 1, the TCB is unlocked and most
9321 * likely gone, return value of 0, the TCB is still
9322 * locked.
9323 */
9324 static int
bbr_do_close_wait(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)9325 bbr_do_close_wait(struct mbuf *m, struct tcphdr *th, struct socket *so,
9326 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9327 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9328 {
9329 struct tcp_bbr *bbr;
9330 int32_t ret_val;
9331
9332 INP_WLOCK_ASSERT(tptoinpcb(tp));
9333
9334 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9335 ctf_calc_rwin(so, tp);
9336 if ((thflags & TH_RST) ||
9337 (tp->t_fin_is_rst && (thflags & TH_FIN)))
9338 return (ctf_process_rst(m, th, so, tp));
9339 /*
9340 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
9341 * synchronized state.
9342 */
9343 if (thflags & TH_SYN) {
9344 ctf_challenge_ack(m, th, tp, iptos, &ret_val);
9345 return (ret_val);
9346 }
9347 /*
9348 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9349 * it's less than ts_recent, drop it.
9350 */
9351 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9352 TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9353 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9354 return (ret_val);
9355 }
9356 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9357 return (ret_val);
9358 }
9359 /*
9360 * If last ACK falls within this segment's sequence numbers, record
9361 * its timestamp. NOTE: 1) That the test incorporates suggestions
9362 * from the latest proposal of the tcplw@cray.com list (Braden
9363 * 1993/04/26). 2) That updating only on newer timestamps interferes
9364 * with our earlier PAWS tests, so this check should be solely
9365 * predicated on the sequence space of this segment. 3) That we
9366 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9367 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9368 * SEG.Len, This modified check allows us to overcome RFC1323's
9369 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9370 * p.869. In such cases, we can still calculate the RTT correctly
9371 * when RCV.NXT == Last.ACK.Sent.
9372 */
9373 if ((to->to_flags & TOF_TS) != 0 &&
9374 SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9375 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9376 ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9377 tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
9378 tp->ts_recent = to->to_tsval;
9379 }
9380 /*
9381 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
9382 * is on (half-synchronized state), then queue data for later
9383 * processing; else drop segment and return.
9384 */
9385 if ((thflags & TH_ACK) == 0) {
9386 if (tp->t_flags & TF_NEEDSYN) {
9387 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9388 tiwin, thflags, nxt_pkt));
9389 } else if (tp->t_flags & TF_ACKNOW) {
9390 ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
9391 bbr->r_wanted_output = 1;
9392 return (ret_val);
9393 } else {
9394 ctf_do_drop(m, NULL);
9395 return (0);
9396 }
9397 }
9398 /*
9399 * Ack processing.
9400 */
9401 if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, NULL, thflags, &ret_val)) {
9402 return (ret_val);
9403 }
9404 if (sbavail(&so->so_snd)) {
9405 if (ctf_progress_timeout_check(tp, true)) {
9406 bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
9407 ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
9408 return (1);
9409 }
9410 }
9411 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9412 tiwin, thflags, nxt_pkt));
9413 }
9414
9415 static int
bbr_check_data_after_close(struct mbuf * m,struct tcp_bbr * bbr,struct tcpcb * tp,int32_t * tlen,struct tcphdr * th,struct socket * so)9416 bbr_check_data_after_close(struct mbuf *m, struct tcp_bbr *bbr,
9417 struct tcpcb *tp, int32_t * tlen, struct tcphdr *th, struct socket *so)
9418 {
9419
9420 if (bbr->rc_allow_data_af_clo == 0) {
9421 close_now:
9422 tcp_log_end_status(tp, TCP_EI_STATUS_DATA_A_CLOSE);
9423 /* tcp_close will kill the inp pre-log the Reset */
9424 tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
9425 tp = tcp_close(tp);
9426 KMOD_TCPSTAT_INC(tcps_rcvafterclose);
9427 ctf_do_dropwithreset(m, tp, th, BANDLIM_UNLIMITED, (*tlen));
9428 return (1);
9429 }
9430 if (sbavail(&so->so_snd) == 0)
9431 goto close_now;
9432 /* Ok we allow data that is ignored and a followup reset */
9433 tp->rcv_nxt = th->th_seq + *tlen;
9434 tp->t_flags2 |= TF2_DROP_AF_DATA;
9435 bbr->r_wanted_output = 1;
9436 *tlen = 0;
9437 return (0);
9438 }
9439
9440 /*
9441 * Return value of 1, the TCB is unlocked and most
9442 * likely gone, return value of 0, the TCB is still
9443 * locked.
9444 */
9445 static int
bbr_do_fin_wait_1(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)9446 bbr_do_fin_wait_1(struct mbuf *m, struct tcphdr *th, struct socket *so,
9447 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9448 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9449 {
9450 int32_t ourfinisacked = 0;
9451 int32_t ret_val;
9452 struct tcp_bbr *bbr;
9453
9454 INP_WLOCK_ASSERT(tptoinpcb(tp));
9455
9456 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9457 ctf_calc_rwin(so, tp);
9458 if ((thflags & TH_RST) ||
9459 (tp->t_fin_is_rst && (thflags & TH_FIN)))
9460 return (ctf_process_rst(m, th, so, tp));
9461 /*
9462 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
9463 * synchronized state.
9464 */
9465 if (thflags & TH_SYN) {
9466 ctf_challenge_ack(m, th, tp, iptos, &ret_val);
9467 return (ret_val);
9468 }
9469 /*
9470 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9471 * it's less than ts_recent, drop it.
9472 */
9473 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9474 TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9475 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9476 return (ret_val);
9477 }
9478 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9479 return (ret_val);
9480 }
9481 /*
9482 * If new data are received on a connection after the user processes
9483 * are gone, then RST the other end.
9484 * We call a new function now so we might continue and setup
9485 * to reset at all data being ack'd.
9486 */
9487 if ((tp->t_flags & TF_CLOSED) && tlen &&
9488 bbr_check_data_after_close(m, bbr, tp, &tlen, th, so))
9489 return (1);
9490 /*
9491 * If last ACK falls within this segment's sequence numbers, record
9492 * its timestamp. NOTE: 1) That the test incorporates suggestions
9493 * from the latest proposal of the tcplw@cray.com list (Braden
9494 * 1993/04/26). 2) That updating only on newer timestamps interferes
9495 * with our earlier PAWS tests, so this check should be solely
9496 * predicated on the sequence space of this segment. 3) That we
9497 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9498 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9499 * SEG.Len, This modified check allows us to overcome RFC1323's
9500 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9501 * p.869. In such cases, we can still calculate the RTT correctly
9502 * when RCV.NXT == Last.ACK.Sent.
9503 */
9504 if ((to->to_flags & TOF_TS) != 0 &&
9505 SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9506 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9507 ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9508 tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
9509 tp->ts_recent = to->to_tsval;
9510 }
9511 /*
9512 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
9513 * is on (half-synchronized state), then queue data for later
9514 * processing; else drop segment and return.
9515 */
9516 if ((thflags & TH_ACK) == 0) {
9517 if (tp->t_flags & TF_NEEDSYN) {
9518 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9519 tiwin, thflags, nxt_pkt));
9520 } else if (tp->t_flags & TF_ACKNOW) {
9521 ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
9522 bbr->r_wanted_output = 1;
9523 return (ret_val);
9524 } else {
9525 ctf_do_drop(m, NULL);
9526 return (0);
9527 }
9528 }
9529 /*
9530 * Ack processing.
9531 */
9532 if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
9533 return (ret_val);
9534 }
9535 if (ourfinisacked) {
9536 /*
9537 * If we can't receive any more data, then closing user can
9538 * proceed. Starting the timer is contrary to the
9539 * specification, but if we don't get a FIN we'll hang
9540 * forever.
9541 *
9542 * XXXjl: we should release the tp also, and use a
9543 * compressed state.
9544 */
9545 if (so->so_rcv.sb_state & SBS_CANTRCVMORE) {
9546 soisdisconnected(so);
9547 tcp_timer_activate(tp, TT_2MSL,
9548 (tcp_fast_finwait2_recycle ?
9549 tcp_finwait2_timeout :
9550 TP_MAXIDLE(tp)));
9551 }
9552 tcp_state_change(tp, TCPS_FIN_WAIT_2);
9553 }
9554 if (sbavail(&so->so_snd)) {
9555 if (ctf_progress_timeout_check(tp, true)) {
9556 bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
9557 ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
9558 return (1);
9559 }
9560 }
9561 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9562 tiwin, thflags, nxt_pkt));
9563 }
9564
9565 /*
9566 * Return value of 1, the TCB is unlocked and most
9567 * likely gone, return value of 0, the TCB is still
9568 * locked.
9569 */
9570 static int
bbr_do_closing(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)9571 bbr_do_closing(struct mbuf *m, struct tcphdr *th, struct socket *so,
9572 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9573 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9574 {
9575 int32_t ourfinisacked = 0;
9576 int32_t ret_val;
9577 struct tcp_bbr *bbr;
9578
9579 INP_WLOCK_ASSERT(tptoinpcb(tp));
9580
9581 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9582 ctf_calc_rwin(so, tp);
9583 if ((thflags & TH_RST) ||
9584 (tp->t_fin_is_rst && (thflags & TH_FIN)))
9585 return (ctf_process_rst(m, th, so, tp));
9586 /*
9587 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
9588 * synchronized state.
9589 */
9590 if (thflags & TH_SYN) {
9591 ctf_challenge_ack(m, th, tp, iptos, &ret_val);
9592 return (ret_val);
9593 }
9594 /*
9595 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9596 * it's less than ts_recent, drop it.
9597 */
9598 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9599 TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9600 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9601 return (ret_val);
9602 }
9603 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9604 return (ret_val);
9605 }
9606 /*
9607 * If last ACK falls within this segment's sequence numbers, record
9608 * its timestamp. NOTE: 1) That the test incorporates suggestions
9609 * from the latest proposal of the tcplw@cray.com list (Braden
9610 * 1993/04/26). 2) That updating only on newer timestamps interferes
9611 * with our earlier PAWS tests, so this check should be solely
9612 * predicated on the sequence space of this segment. 3) That we
9613 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9614 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9615 * SEG.Len, This modified check allows us to overcome RFC1323's
9616 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9617 * p.869. In such cases, we can still calculate the RTT correctly
9618 * when RCV.NXT == Last.ACK.Sent.
9619 */
9620 if ((to->to_flags & TOF_TS) != 0 &&
9621 SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9622 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9623 ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9624 tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
9625 tp->ts_recent = to->to_tsval;
9626 }
9627 /*
9628 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
9629 * is on (half-synchronized state), then queue data for later
9630 * processing; else drop segment and return.
9631 */
9632 if ((thflags & TH_ACK) == 0) {
9633 if (tp->t_flags & TF_NEEDSYN) {
9634 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9635 tiwin, thflags, nxt_pkt));
9636 } else if (tp->t_flags & TF_ACKNOW) {
9637 ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
9638 bbr->r_wanted_output = 1;
9639 return (ret_val);
9640 } else {
9641 ctf_do_drop(m, NULL);
9642 return (0);
9643 }
9644 }
9645 /*
9646 * Ack processing.
9647 */
9648 if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
9649 return (ret_val);
9650 }
9651 if (ourfinisacked) {
9652 tcp_twstart(tp);
9653 m_freem(m);
9654 return (1);
9655 }
9656 if (sbavail(&so->so_snd)) {
9657 if (ctf_progress_timeout_check(tp, true)) {
9658 bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
9659 ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
9660 return (1);
9661 }
9662 }
9663 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9664 tiwin, thflags, nxt_pkt));
9665 }
9666
9667 /*
9668 * Return value of 1, the TCB is unlocked and most
9669 * likely gone, return value of 0, the TCB is still
9670 * locked.
9671 */
9672 static int
bbr_do_lastack(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)9673 bbr_do_lastack(struct mbuf *m, struct tcphdr *th, struct socket *so,
9674 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9675 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9676 {
9677 int32_t ourfinisacked = 0;
9678 int32_t ret_val;
9679 struct tcp_bbr *bbr;
9680
9681 INP_WLOCK_ASSERT(tptoinpcb(tp));
9682
9683 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9684 ctf_calc_rwin(so, tp);
9685 if ((thflags & TH_RST) ||
9686 (tp->t_fin_is_rst && (thflags & TH_FIN)))
9687 return (ctf_process_rst(m, th, so, tp));
9688 /*
9689 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
9690 * synchronized state.
9691 */
9692 if (thflags & TH_SYN) {
9693 ctf_challenge_ack(m, th, tp, iptos, &ret_val);
9694 return (ret_val);
9695 }
9696 /*
9697 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9698 * it's less than ts_recent, drop it.
9699 */
9700 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9701 TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9702 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9703 return (ret_val);
9704 }
9705 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9706 return (ret_val);
9707 }
9708 /*
9709 * If last ACK falls within this segment's sequence numbers, record
9710 * its timestamp. NOTE: 1) That the test incorporates suggestions
9711 * from the latest proposal of the tcplw@cray.com list (Braden
9712 * 1993/04/26). 2) That updating only on newer timestamps interferes
9713 * with our earlier PAWS tests, so this check should be solely
9714 * predicated on the sequence space of this segment. 3) That we
9715 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9716 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9717 * SEG.Len, This modified check allows us to overcome RFC1323's
9718 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9719 * p.869. In such cases, we can still calculate the RTT correctly
9720 * when RCV.NXT == Last.ACK.Sent.
9721 */
9722 if ((to->to_flags & TOF_TS) != 0 &&
9723 SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9724 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9725 ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9726 tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
9727 tp->ts_recent = to->to_tsval;
9728 }
9729 /*
9730 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
9731 * is on (half-synchronized state), then queue data for later
9732 * processing; else drop segment and return.
9733 */
9734 if ((thflags & TH_ACK) == 0) {
9735 if (tp->t_flags & TF_NEEDSYN) {
9736 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9737 tiwin, thflags, nxt_pkt));
9738 } else if (tp->t_flags & TF_ACKNOW) {
9739 ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
9740 bbr->r_wanted_output = 1;
9741 return (ret_val);
9742 } else {
9743 ctf_do_drop(m, NULL);
9744 return (0);
9745 }
9746 }
9747 /*
9748 * case TCPS_LAST_ACK: Ack processing.
9749 */
9750 if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
9751 return (ret_val);
9752 }
9753 if (ourfinisacked) {
9754 tp = tcp_close(tp);
9755 ctf_do_drop(m, tp);
9756 return (1);
9757 }
9758 if (sbavail(&so->so_snd)) {
9759 if (ctf_progress_timeout_check(tp, true)) {
9760 bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
9761 ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
9762 return (1);
9763 }
9764 }
9765 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9766 tiwin, thflags, nxt_pkt));
9767 }
9768
9769 /*
9770 * Return value of 1, the TCB is unlocked and most
9771 * likely gone, return value of 0, the TCB is still
9772 * locked.
9773 */
9774 static int
bbr_do_fin_wait_2(struct mbuf * m,struct tcphdr * th,struct socket * so,struct tcpcb * tp,struct tcpopt * to,int32_t drop_hdrlen,int32_t tlen,uint32_t tiwin,int32_t thflags,int32_t nxt_pkt,uint8_t iptos)9775 bbr_do_fin_wait_2(struct mbuf *m, struct tcphdr *th, struct socket *so,
9776 struct tcpcb *tp, struct tcpopt *to, int32_t drop_hdrlen, int32_t tlen,
9777 uint32_t tiwin, int32_t thflags, int32_t nxt_pkt, uint8_t iptos)
9778 {
9779 int32_t ourfinisacked = 0;
9780 int32_t ret_val;
9781 struct tcp_bbr *bbr;
9782
9783 INP_WLOCK_ASSERT(tptoinpcb(tp));
9784
9785 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
9786 ctf_calc_rwin(so, tp);
9787 /* Reset receive buffer auto scaling when not in bulk receive mode. */
9788 if ((thflags & TH_RST) ||
9789 (tp->t_fin_is_rst && (thflags & TH_FIN)))
9790 return (ctf_process_rst(m, th, so, tp));
9791
9792 /*
9793 * RFC5961 Section 4.2 Send challenge ACK for any SYN in
9794 * synchronized state.
9795 */
9796 if (thflags & TH_SYN) {
9797 ctf_challenge_ack(m, th, tp, iptos, &ret_val);
9798 return (ret_val);
9799 }
9800 /*
9801 * RFC 1323 PAWS: If we have a timestamp reply on this segment and
9802 * it's less than ts_recent, drop it.
9803 */
9804 if ((to->to_flags & TOF_TS) != 0 && tp->ts_recent &&
9805 TSTMP_LT(to->to_tsval, tp->ts_recent)) {
9806 if (ctf_ts_check(m, th, tp, tlen, thflags, &ret_val))
9807 return (ret_val);
9808 }
9809 if (ctf_drop_checks(to, m, th, tp, &tlen, &thflags, &drop_hdrlen, &ret_val)) {
9810 return (ret_val);
9811 }
9812 /*
9813 * If new data are received on a connection after the user processes
9814 * are gone, then we may RST the other end depending on the outcome
9815 * of bbr_check_data_after_close.
9816 * We call a new function now so we might continue and setup
9817 * to reset at all data being ack'd.
9818 */
9819 if ((tp->t_flags & TF_CLOSED) && tlen &&
9820 bbr_check_data_after_close(m, bbr, tp, &tlen, th, so))
9821 return (1);
9822 /*
9823 * If last ACK falls within this segment's sequence numbers, record
9824 * its timestamp. NOTE: 1) That the test incorporates suggestions
9825 * from the latest proposal of the tcplw@cray.com list (Braden
9826 * 1993/04/26). 2) That updating only on newer timestamps interferes
9827 * with our earlier PAWS tests, so this check should be solely
9828 * predicated on the sequence space of this segment. 3) That we
9829 * modify the segment boundary check to be Last.ACK.Sent <= SEG.SEQ
9830 * + SEG.Len instead of RFC1323's Last.ACK.Sent < SEG.SEQ +
9831 * SEG.Len, This modified check allows us to overcome RFC1323's
9832 * limitations as described in Stevens TCP/IP Illustrated Vol. 2
9833 * p.869. In such cases, we can still calculate the RTT correctly
9834 * when RCV.NXT == Last.ACK.Sent.
9835 */
9836 if ((to->to_flags & TOF_TS) != 0 &&
9837 SEQ_LEQ(th->th_seq, tp->last_ack_sent) &&
9838 SEQ_LEQ(tp->last_ack_sent, th->th_seq + tlen +
9839 ((thflags & (TH_SYN | TH_FIN)) != 0))) {
9840 tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
9841 tp->ts_recent = to->to_tsval;
9842 }
9843 /*
9844 * If the ACK bit is off: if in SYN-RECEIVED state or SENDSYN flag
9845 * is on (half-synchronized state), then queue data for later
9846 * processing; else drop segment and return.
9847 */
9848 if ((thflags & TH_ACK) == 0) {
9849 if (tp->t_flags & TF_NEEDSYN) {
9850 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9851 tiwin, thflags, nxt_pkt));
9852 } else if (tp->t_flags & TF_ACKNOW) {
9853 ctf_do_dropafterack(m, tp, th, thflags, tlen, &ret_val);
9854 bbr->r_wanted_output = 1;
9855 return (ret_val);
9856 } else {
9857 ctf_do_drop(m, NULL);
9858 return (0);
9859 }
9860 }
9861 /*
9862 * Ack processing.
9863 */
9864 if (bbr_process_ack(m, th, so, tp, to, tiwin, tlen, &ourfinisacked, thflags, &ret_val)) {
9865 return (ret_val);
9866 }
9867 if (sbavail(&so->so_snd)) {
9868 if (ctf_progress_timeout_check(tp, true)) {
9869 bbr_log_progress_event(bbr, tp, tick, PROGRESS_DROP, __LINE__);
9870 ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
9871 return (1);
9872 }
9873 }
9874 return (bbr_process_data(m, th, so, tp, drop_hdrlen, tlen,
9875 tiwin, thflags, nxt_pkt));
9876 }
9877
9878 static void
bbr_stop_all_timers(struct tcpcb * tp,struct tcp_bbr * bbr)9879 bbr_stop_all_timers(struct tcpcb *tp, struct tcp_bbr *bbr)
9880 {
9881 /*
9882 * Assure no timers are running.
9883 */
9884 if (tcp_timer_active(tp, TT_PERSIST)) {
9885 /* We enter in persists, set the flag appropriately */
9886 bbr->rc_in_persist = 1;
9887 }
9888 if (tcp_in_hpts(bbr->rc_tp)) {
9889 tcp_hpts_remove(bbr->rc_tp);
9890 }
9891 }
9892
9893 static void
bbr_google_mode_on(struct tcp_bbr * bbr)9894 bbr_google_mode_on(struct tcp_bbr *bbr)
9895 {
9896 bbr->rc_use_google = 1;
9897 bbr->rc_no_pacing = 0;
9898 bbr->r_ctl.bbr_google_discount = bbr_google_discount;
9899 bbr->r_use_policer = bbr_policer_detection_enabled;
9900 bbr->r_ctl.rc_probertt_int = (USECS_IN_SECOND * 10);
9901 bbr->bbr_use_rack_cheat = 0;
9902 bbr->r_ctl.rc_incr_tmrs = 0;
9903 bbr->r_ctl.rc_inc_tcp_oh = 0;
9904 bbr->r_ctl.rc_inc_ip_oh = 0;
9905 bbr->r_ctl.rc_inc_enet_oh = 0;
9906 reset_time(&bbr->r_ctl.rc_delrate,
9907 BBR_NUM_RTTS_FOR_GOOG_DEL_LIMIT);
9908 reset_time_small(&bbr->r_ctl.rc_rttprop,
9909 (11 * USECS_IN_SECOND));
9910 tcp_bbr_tso_size_check(bbr, tcp_get_usecs(&bbr->rc_tv));
9911 }
9912
9913 static void
bbr_google_mode_off(struct tcp_bbr * bbr)9914 bbr_google_mode_off(struct tcp_bbr *bbr)
9915 {
9916 bbr->rc_use_google = 0;
9917 bbr->r_ctl.bbr_google_discount = 0;
9918 bbr->no_pacing_until = bbr_no_pacing_until;
9919 bbr->r_use_policer = 0;
9920 if (bbr->no_pacing_until)
9921 bbr->rc_no_pacing = 1;
9922 else
9923 bbr->rc_no_pacing = 0;
9924 if (bbr_use_rack_resend_cheat)
9925 bbr->bbr_use_rack_cheat = 1;
9926 else
9927 bbr->bbr_use_rack_cheat = 0;
9928 if (bbr_incr_timers)
9929 bbr->r_ctl.rc_incr_tmrs = 1;
9930 else
9931 bbr->r_ctl.rc_incr_tmrs = 0;
9932 if (bbr_include_tcp_oh)
9933 bbr->r_ctl.rc_inc_tcp_oh = 1;
9934 else
9935 bbr->r_ctl.rc_inc_tcp_oh = 0;
9936 if (bbr_include_ip_oh)
9937 bbr->r_ctl.rc_inc_ip_oh = 1;
9938 else
9939 bbr->r_ctl.rc_inc_ip_oh = 0;
9940 if (bbr_include_enet_oh)
9941 bbr->r_ctl.rc_inc_enet_oh = 1;
9942 else
9943 bbr->r_ctl.rc_inc_enet_oh = 0;
9944 bbr->r_ctl.rc_probertt_int = bbr_rtt_probe_limit;
9945 reset_time(&bbr->r_ctl.rc_delrate,
9946 bbr_num_pktepo_for_del_limit);
9947 reset_time_small(&bbr->r_ctl.rc_rttprop,
9948 (bbr_filter_len_sec * USECS_IN_SECOND));
9949 tcp_bbr_tso_size_check(bbr, tcp_get_usecs(&bbr->rc_tv));
9950 }
9951 /*
9952 * Return 0 on success, non-zero on failure
9953 * which indicates the error (usually no memory).
9954 */
9955 static int
bbr_init(struct tcpcb * tp,void ** ptr)9956 bbr_init(struct tcpcb *tp, void **ptr)
9957 {
9958 struct inpcb *inp = tptoinpcb(tp);
9959 struct tcp_bbr *bbr = NULL;
9960 uint32_t cts;
9961
9962 tcp_hpts_init(tp);
9963
9964 *ptr = uma_zalloc(bbr_pcb_zone, (M_NOWAIT | M_ZERO));
9965 if (*ptr == NULL) {
9966 /*
9967 * We need to allocate memory but cant. The INP and INP_INFO
9968 * locks and they are recursive (happens during setup. So a
9969 * scheme to drop the locks fails :(
9970 *
9971 */
9972 return (ENOMEM);
9973 }
9974 bbr = (struct tcp_bbr *)*ptr;
9975 bbr->rtt_valid = 0;
9976 tp->t_flags2 |= TF2_CANNOT_DO_ECN;
9977 tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
9978 /* Take off any undesired flags */
9979 tp->t_flags2 &= ~TF2_MBUF_QUEUE_READY;
9980 tp->t_flags2 &= ~TF2_DONT_SACK_QUEUE;
9981 tp->t_flags2 &= ~TF2_MBUF_ACKCMP;
9982 tp->t_flags2 &= ~TF2_MBUF_L_ACKS;
9983
9984 TAILQ_INIT(&bbr->r_ctl.rc_map);
9985 TAILQ_INIT(&bbr->r_ctl.rc_free);
9986 TAILQ_INIT(&bbr->r_ctl.rc_tmap);
9987 bbr->rc_tp = tp;
9988 bbr->rc_inp = inp;
9989 cts = tcp_get_usecs(&bbr->rc_tv);
9990 tp->t_acktime = 0;
9991 bbr->rc_allow_data_af_clo = bbr_ignore_data_after_close;
9992 bbr->r_ctl.rc_reorder_fade = bbr_reorder_fade;
9993 bbr->rc_tlp_threshold = bbr_tlp_thresh;
9994 bbr->r_ctl.rc_reorder_shift = bbr_reorder_thresh;
9995 bbr->r_ctl.rc_pkt_delay = bbr_pkt_delay;
9996 bbr->r_ctl.rc_min_to = bbr_min_to;
9997 bbr->rc_bbr_state = BBR_STATE_STARTUP;
9998 bbr->r_ctl.bbr_lost_at_state = 0;
9999 bbr->r_ctl.rc_lost_at_startup = 0;
10000 bbr->rc_all_timers_stopped = 0;
10001 bbr->r_ctl.rc_bbr_lastbtlbw = 0;
10002 bbr->r_ctl.rc_pkt_epoch_del = 0;
10003 bbr->r_ctl.rc_pkt_epoch = 0;
10004 bbr->r_ctl.rc_lowest_rtt = 0xffffffff;
10005 bbr->r_ctl.rc_bbr_hptsi_gain = bbr_high_gain;
10006 bbr->r_ctl.rc_bbr_cwnd_gain = bbr_high_gain;
10007 bbr->r_ctl.rc_went_idle_time = cts;
10008 bbr->rc_pacer_started = cts;
10009 bbr->r_ctl.rc_pkt_epoch_time = cts;
10010 bbr->r_ctl.rc_rcvtime = cts;
10011 bbr->r_ctl.rc_bbr_state_time = cts;
10012 bbr->r_ctl.rc_del_time = cts;
10013 bbr->r_ctl.rc_tlp_rxt_last_time = cts;
10014 bbr->r_ctl.last_in_probertt = cts;
10015 bbr->skip_gain = 0;
10016 bbr->gain_is_limited = 0;
10017 bbr->no_pacing_until = bbr_no_pacing_until;
10018 if (bbr->no_pacing_until)
10019 bbr->rc_no_pacing = 1;
10020 if (bbr_use_google_algo) {
10021 bbr->rc_no_pacing = 0;
10022 bbr->rc_use_google = 1;
10023 bbr->r_ctl.bbr_google_discount = bbr_google_discount;
10024 bbr->r_use_policer = bbr_policer_detection_enabled;
10025 } else {
10026 bbr->rc_use_google = 0;
10027 bbr->r_ctl.bbr_google_discount = 0;
10028 bbr->r_use_policer = 0;
10029 }
10030 if (bbr_ts_limiting)
10031 bbr->rc_use_ts_limit = 1;
10032 else
10033 bbr->rc_use_ts_limit = 0;
10034 if (bbr_ts_can_raise)
10035 bbr->ts_can_raise = 1;
10036 else
10037 bbr->ts_can_raise = 0;
10038 if (V_tcp_delack_enabled == 1)
10039 tp->t_delayed_ack = 2;
10040 else if (V_tcp_delack_enabled == 0)
10041 tp->t_delayed_ack = 0;
10042 else if (V_tcp_delack_enabled < 100)
10043 tp->t_delayed_ack = V_tcp_delack_enabled;
10044 else
10045 tp->t_delayed_ack = 2;
10046 if (bbr->rc_use_google == 0)
10047 bbr->r_ctl.rc_probertt_int = bbr_rtt_probe_limit;
10048 else
10049 bbr->r_ctl.rc_probertt_int = (USECS_IN_SECOND * 10);
10050 bbr->r_ctl.rc_min_rto_ms = bbr_rto_min_ms;
10051 bbr->rc_max_rto_sec = bbr_rto_max_sec;
10052 bbr->rc_init_win = bbr_def_init_win;
10053 if (tp->t_flags & TF_REQ_TSTMP)
10054 bbr->rc_last_options = TCP_TS_OVERHEAD;
10055 bbr->r_ctl.rc_pace_max_segs = tp->t_maxseg - bbr->rc_last_options;
10056 bbr->r_ctl.rc_high_rwnd = tp->snd_wnd;
10057 bbr->r_init_rtt = 1;
10058
10059 counter_u64_add(bbr_flows_nohdwr_pacing, 1);
10060 if (bbr_allow_hdwr_pacing)
10061 bbr->bbr_hdw_pace_ena = 1;
10062 else
10063 bbr->bbr_hdw_pace_ena = 0;
10064 if (bbr_sends_full_iwnd)
10065 bbr->bbr_init_win_cheat = 1;
10066 else
10067 bbr->bbr_init_win_cheat = 0;
10068 bbr->r_ctl.bbr_utter_max = bbr_hptsi_utter_max;
10069 bbr->r_ctl.rc_drain_pg = bbr_drain_gain;
10070 bbr->r_ctl.rc_startup_pg = bbr_high_gain;
10071 bbr->rc_loss_exit = bbr_exit_startup_at_loss;
10072 bbr->r_ctl.bbr_rttprobe_gain_val = bbr_rttprobe_gain;
10073 bbr->r_ctl.bbr_hptsi_per_second = bbr_hptsi_per_second;
10074 bbr->r_ctl.bbr_hptsi_segments_delay_tar = bbr_hptsi_segments_delay_tar;
10075 bbr->r_ctl.bbr_hptsi_segments_max = bbr_hptsi_segments_max;
10076 bbr->r_ctl.bbr_hptsi_segments_floor = bbr_hptsi_segments_floor;
10077 bbr->r_ctl.bbr_hptsi_bytes_min = bbr_hptsi_bytes_min;
10078 bbr->r_ctl.bbr_cross_over = bbr_cross_over;
10079 bbr->r_ctl.rc_rtt_shrinks = cts;
10080 if (bbr->rc_use_google) {
10081 setup_time_filter(&bbr->r_ctl.rc_delrate,
10082 FILTER_TYPE_MAX,
10083 BBR_NUM_RTTS_FOR_GOOG_DEL_LIMIT);
10084 setup_time_filter_small(&bbr->r_ctl.rc_rttprop,
10085 FILTER_TYPE_MIN, (11 * USECS_IN_SECOND));
10086 } else {
10087 setup_time_filter(&bbr->r_ctl.rc_delrate,
10088 FILTER_TYPE_MAX,
10089 bbr_num_pktepo_for_del_limit);
10090 setup_time_filter_small(&bbr->r_ctl.rc_rttprop,
10091 FILTER_TYPE_MIN, (bbr_filter_len_sec * USECS_IN_SECOND));
10092 }
10093 bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_INIT, 0);
10094 if (bbr_uses_idle_restart)
10095 bbr->rc_use_idle_restart = 1;
10096 else
10097 bbr->rc_use_idle_restart = 0;
10098 bbr->r_ctl.rc_bbr_cur_del_rate = 0;
10099 bbr->r_ctl.rc_initial_hptsi_bw = bbr_initial_bw_bps;
10100 if (bbr_resends_use_tso)
10101 bbr->rc_resends_use_tso = 1;
10102 if (tp->snd_una != tp->snd_max) {
10103 /* Create a send map for the current outstanding data */
10104 struct bbr_sendmap *rsm;
10105
10106 rsm = bbr_alloc(bbr);
10107 if (rsm == NULL) {
10108 uma_zfree(bbr_pcb_zone, *ptr);
10109 *ptr = NULL;
10110 return (ENOMEM);
10111 }
10112 rsm->r_rtt_not_allowed = 1;
10113 rsm->r_tim_lastsent[0] = cts;
10114 rsm->r_rtr_cnt = 1;
10115 rsm->r_rtr_bytes = 0;
10116 rsm->r_start = tp->snd_una;
10117 rsm->r_end = tp->snd_max;
10118 rsm->r_dupack = 0;
10119 rsm->r_delivered = bbr->r_ctl.rc_delivered;
10120 rsm->r_ts_valid = 0;
10121 rsm->r_del_ack_ts = tp->ts_recent;
10122 rsm->r_del_time = cts;
10123 if (bbr->r_ctl.r_app_limited_until)
10124 rsm->r_app_limited = 1;
10125 else
10126 rsm->r_app_limited = 0;
10127 TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_map, rsm, r_next);
10128 TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_tmap, rsm, r_tnext);
10129 rsm->r_in_tmap = 1;
10130 if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW)
10131 rsm->r_bbr_state = bbr_state_val(bbr);
10132 else
10133 rsm->r_bbr_state = 8;
10134 }
10135 if (bbr_use_rack_resend_cheat && (bbr->rc_use_google == 0))
10136 bbr->bbr_use_rack_cheat = 1;
10137 if (bbr_incr_timers && (bbr->rc_use_google == 0))
10138 bbr->r_ctl.rc_incr_tmrs = 1;
10139 if (bbr_include_tcp_oh && (bbr->rc_use_google == 0))
10140 bbr->r_ctl.rc_inc_tcp_oh = 1;
10141 if (bbr_include_ip_oh && (bbr->rc_use_google == 0))
10142 bbr->r_ctl.rc_inc_ip_oh = 1;
10143 if (bbr_include_enet_oh && (bbr->rc_use_google == 0))
10144 bbr->r_ctl.rc_inc_enet_oh = 1;
10145
10146 bbr_log_type_statechange(bbr, cts, __LINE__);
10147 if (TCPS_HAVEESTABLISHED(tp->t_state) &&
10148 (tp->t_srtt)) {
10149 uint32_t rtt;
10150
10151 rtt = (TICKS_2_USEC(tp->t_srtt) >> TCP_RTT_SHIFT);
10152 apply_filter_min_small(&bbr->r_ctl.rc_rttprop, rtt, cts);
10153 }
10154 /* announce the settings and state */
10155 bbr_log_settings_change(bbr, BBR_RECOVERY_LOWRTT);
10156 tcp_bbr_tso_size_check(bbr, cts);
10157 /*
10158 * Now call the generic function to start a timer. This will place
10159 * the TCB on the hptsi wheel if a timer is needed with appropriate
10160 * flags.
10161 */
10162 bbr_stop_all_timers(tp, bbr);
10163 /*
10164 * Validate the timers are not in usec, if they are convert.
10165 * BBR should in theory move to USEC and get rid of a
10166 * lot of the TICKS_2 calls.. but for now we stay
10167 * with tick timers.
10168 */
10169 tcp_change_time_units(tp, TCP_TMR_GRANULARITY_TICKS);
10170 TCPT_RANGESET(tp->t_rxtcur,
10171 ((tp->t_srtt >> 2) + tp->t_rttvar) >> 1,
10172 tp->t_rttmin, TCPTV_REXMTMAX);
10173 bbr_start_hpts_timer(bbr, tp, cts, 5, 0, 0);
10174 return (0);
10175 }
10176
10177 /*
10178 * Return 0 if we can accept the connection. Return
10179 * non-zero if we can't handle the connection. A EAGAIN
10180 * means you need to wait until the connection is up.
10181 * a EADDRNOTAVAIL means we can never handle the connection
10182 * (no SACK).
10183 */
10184 static int
bbr_handoff_ok(struct tcpcb * tp)10185 bbr_handoff_ok(struct tcpcb *tp)
10186 {
10187 if ((tp->t_state == TCPS_CLOSED) ||
10188 (tp->t_state == TCPS_LISTEN)) {
10189 /* Sure no problem though it may not stick */
10190 return (0);
10191 }
10192 if ((tp->t_state == TCPS_SYN_SENT) ||
10193 (tp->t_state == TCPS_SYN_RECEIVED)) {
10194 /*
10195 * We really don't know you have to get to ESTAB or beyond
10196 * to tell.
10197 */
10198 return (EAGAIN);
10199 }
10200 if (tp->t_flags & TF_SENTFIN)
10201 return (EINVAL);
10202 if ((tp->t_flags & TF_SACK_PERMIT) || bbr_sack_not_required) {
10203 return (0);
10204 }
10205 /*
10206 * If we reach here we don't do SACK on this connection so we can
10207 * never do rack.
10208 */
10209 return (EINVAL);
10210 }
10211
10212 static void
bbr_fini(struct tcpcb * tp,int32_t tcb_is_purged)10213 bbr_fini(struct tcpcb *tp, int32_t tcb_is_purged)
10214 {
10215 if (tp->t_fb_ptr) {
10216 uint32_t calc;
10217 struct tcp_bbr *bbr;
10218 struct bbr_sendmap *rsm;
10219
10220 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
10221 if (bbr->r_ctl.crte)
10222 tcp_rel_pacing_rate(bbr->r_ctl.crte, bbr->rc_tp);
10223 bbr_log_flowend(bbr);
10224 bbr->rc_tp = NULL;
10225 if (bbr->bbr_hdrw_pacing)
10226 counter_u64_add(bbr_flows_whdwr_pacing, -1);
10227 else
10228 counter_u64_add(bbr_flows_nohdwr_pacing, -1);
10229 if (bbr->r_ctl.crte != NULL) {
10230 tcp_rel_pacing_rate(bbr->r_ctl.crte, tp);
10231 bbr->r_ctl.crte = NULL;
10232 }
10233 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
10234 while (rsm) {
10235 TAILQ_REMOVE(&bbr->r_ctl.rc_map, rsm, r_next);
10236 uma_zfree(bbr_zone, rsm);
10237 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
10238 }
10239 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_free);
10240 while (rsm) {
10241 TAILQ_REMOVE(&bbr->r_ctl.rc_free, rsm, r_next);
10242 uma_zfree(bbr_zone, rsm);
10243 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_free);
10244 }
10245 calc = bbr->r_ctl.rc_high_rwnd - bbr->r_ctl.rc_init_rwnd;
10246 if (calc > (bbr->r_ctl.rc_init_rwnd / 10))
10247 BBR_STAT_INC(bbr_dynamic_rwnd);
10248 else
10249 BBR_STAT_INC(bbr_static_rwnd);
10250 bbr->r_ctl.rc_free_cnt = 0;
10251 uma_zfree(bbr_pcb_zone, tp->t_fb_ptr);
10252 tp->t_fb_ptr = NULL;
10253 }
10254 /* Make sure snd_nxt is correctly set */
10255 tp->snd_nxt = tp->snd_max;
10256 }
10257
10258 static void
bbr_set_state(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t win)10259 bbr_set_state(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t win)
10260 {
10261 switch (tp->t_state) {
10262 case TCPS_SYN_SENT:
10263 bbr->r_state = TCPS_SYN_SENT;
10264 bbr->r_substate = bbr_do_syn_sent;
10265 break;
10266 case TCPS_SYN_RECEIVED:
10267 bbr->r_state = TCPS_SYN_RECEIVED;
10268 bbr->r_substate = bbr_do_syn_recv;
10269 break;
10270 case TCPS_ESTABLISHED:
10271 bbr->r_ctl.rc_init_rwnd = max(win, bbr->rc_tp->snd_wnd);
10272 bbr->r_state = TCPS_ESTABLISHED;
10273 bbr->r_substate = bbr_do_established;
10274 break;
10275 case TCPS_CLOSE_WAIT:
10276 bbr->r_state = TCPS_CLOSE_WAIT;
10277 bbr->r_substate = bbr_do_close_wait;
10278 break;
10279 case TCPS_FIN_WAIT_1:
10280 bbr->r_state = TCPS_FIN_WAIT_1;
10281 bbr->r_substate = bbr_do_fin_wait_1;
10282 break;
10283 case TCPS_CLOSING:
10284 bbr->r_state = TCPS_CLOSING;
10285 bbr->r_substate = bbr_do_closing;
10286 break;
10287 case TCPS_LAST_ACK:
10288 bbr->r_state = TCPS_LAST_ACK;
10289 bbr->r_substate = bbr_do_lastack;
10290 break;
10291 case TCPS_FIN_WAIT_2:
10292 bbr->r_state = TCPS_FIN_WAIT_2;
10293 bbr->r_substate = bbr_do_fin_wait_2;
10294 break;
10295 case TCPS_LISTEN:
10296 case TCPS_CLOSED:
10297 case TCPS_TIME_WAIT:
10298 default:
10299 break;
10300 };
10301 }
10302
10303 static void
bbr_substate_change(struct tcp_bbr * bbr,uint32_t cts,int32_t line,int dolog)10304 bbr_substate_change(struct tcp_bbr *bbr, uint32_t cts, int32_t line, int dolog)
10305 {
10306 /*
10307 * Now what state are we going into now? Is there adjustments
10308 * needed?
10309 */
10310 int32_t old_state;
10311
10312 old_state = bbr_state_val(bbr);
10313 if (bbr_state_val(bbr) == BBR_SUB_LEVEL1) {
10314 /* Save the lowest srtt we saw in our end of the sub-state */
10315 bbr->rc_hit_state_1 = 0;
10316 if (bbr->r_ctl.bbr_smallest_srtt_this_state != 0xffffffff)
10317 bbr->r_ctl.bbr_smallest_srtt_state2 = bbr->r_ctl.bbr_smallest_srtt_this_state;
10318 }
10319 bbr->rc_bbr_substate++;
10320 if (bbr->rc_bbr_substate >= BBR_SUBSTATE_COUNT) {
10321 /* Cycle back to first state-> gain */
10322 bbr->rc_bbr_substate = 0;
10323 }
10324 if (bbr_state_val(bbr) == BBR_SUB_GAIN) {
10325 /*
10326 * We enter the gain(5/4) cycle (possibly less if
10327 * shallow buffer detection is enabled)
10328 */
10329 if (bbr->skip_gain) {
10330 /*
10331 * Hardware pacing has set our rate to
10332 * the max and limited our b/w just
10333 * do level i.e. no gain.
10334 */
10335 bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[BBR_SUB_LEVEL1];
10336 } else if (bbr->gain_is_limited &&
10337 bbr->bbr_hdrw_pacing &&
10338 bbr->r_ctl.crte) {
10339 /*
10340 * We can't gain above the hardware pacing
10341 * rate which is less than our rate + the gain
10342 * calculate the gain needed to reach the hardware
10343 * pacing rate..
10344 */
10345 uint64_t bw, rate, gain_calc;
10346
10347 bw = bbr_get_bw(bbr);
10348 rate = bbr->r_ctl.crte->rate;
10349 if ((rate > bw) &&
10350 (((bw * (uint64_t)bbr_hptsi_gain[BBR_SUB_GAIN]) / (uint64_t)BBR_UNIT) > rate)) {
10351 gain_calc = (rate * BBR_UNIT) / bw;
10352 if (gain_calc < BBR_UNIT)
10353 gain_calc = BBR_UNIT;
10354 bbr->r_ctl.rc_bbr_hptsi_gain = (uint16_t)gain_calc;
10355 } else {
10356 bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[BBR_SUB_GAIN];
10357 }
10358 } else
10359 bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[BBR_SUB_GAIN];
10360 if ((bbr->rc_use_google == 0) && (bbr_gain_to_target == 0)) {
10361 bbr->r_ctl.rc_bbr_state_atflight = cts;
10362 } else
10363 bbr->r_ctl.rc_bbr_state_atflight = 0;
10364 } else if (bbr_state_val(bbr) == BBR_SUB_DRAIN) {
10365 bbr->rc_hit_state_1 = 1;
10366 bbr->r_ctl.rc_exta_time_gd = 0;
10367 bbr->r_ctl.flightsize_at_drain = ctf_flight_size(bbr->rc_tp,
10368 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
10369 if (bbr_state_drain_2_tar) {
10370 bbr->r_ctl.rc_bbr_state_atflight = 0;
10371 } else
10372 bbr->r_ctl.rc_bbr_state_atflight = cts;
10373 bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[BBR_SUB_DRAIN];
10374 } else {
10375 /* All other cycles hit here 2-7 */
10376 if ((old_state == BBR_SUB_DRAIN) && bbr->rc_hit_state_1) {
10377 if (bbr_sub_drain_slam_cwnd &&
10378 (bbr->rc_use_google == 0) &&
10379 (bbr->rc_tp->snd_cwnd < bbr->r_ctl.rc_saved_cwnd)) {
10380 bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_saved_cwnd;
10381 bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10382 }
10383 if ((cts - bbr->r_ctl.rc_bbr_state_time) > bbr_get_rtt(bbr, BBR_RTT_PROP))
10384 bbr->r_ctl.rc_exta_time_gd += ((cts - bbr->r_ctl.rc_bbr_state_time) -
10385 bbr_get_rtt(bbr, BBR_RTT_PROP));
10386 else
10387 bbr->r_ctl.rc_exta_time_gd = 0;
10388 if (bbr->r_ctl.rc_exta_time_gd) {
10389 bbr->r_ctl.rc_level_state_extra = bbr->r_ctl.rc_exta_time_gd;
10390 /* Now chop up the time for each state (div by 7) */
10391 bbr->r_ctl.rc_level_state_extra /= 7;
10392 if (bbr_rand_ot && bbr->r_ctl.rc_level_state_extra) {
10393 /* Add a randomization */
10394 bbr_randomize_extra_state_time(bbr);
10395 }
10396 }
10397 }
10398 bbr->r_ctl.rc_bbr_state_atflight = max(1, cts);
10399 bbr->r_ctl.rc_bbr_hptsi_gain = bbr_hptsi_gain[bbr_state_val(bbr)];
10400 }
10401 if (bbr->rc_use_google) {
10402 bbr->r_ctl.rc_bbr_state_atflight = max(1, cts);
10403 }
10404 bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
10405 bbr->r_ctl.rc_bbr_cwnd_gain = bbr_cwnd_gain;
10406 if (dolog)
10407 bbr_log_type_statechange(bbr, cts, line);
10408
10409 if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
10410 uint32_t time_in;
10411
10412 time_in = cts - bbr->r_ctl.rc_bbr_state_time;
10413 if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW) {
10414 counter_u64_add(bbr_state_time[(old_state + 5)], time_in);
10415 } else {
10416 counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
10417 }
10418 }
10419 bbr->r_ctl.bbr_smallest_srtt_this_state = 0xffffffff;
10420 bbr_set_state_target(bbr, __LINE__);
10421 if (bbr_sub_drain_slam_cwnd &&
10422 (bbr->rc_use_google == 0) &&
10423 (bbr_state_val(bbr) == BBR_SUB_DRAIN)) {
10424 /* Slam down the cwnd */
10425 bbr->r_ctl.rc_saved_cwnd = bbr->rc_tp->snd_cwnd;
10426 bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
10427 if (bbr_sub_drain_app_limit) {
10428 /* Go app limited if we are on a long drain */
10429 bbr->r_ctl.r_app_limited_until = (bbr->r_ctl.rc_delivered +
10430 ctf_flight_size(bbr->rc_tp,
10431 (bbr->r_ctl.rc_sacked +
10432 bbr->r_ctl.rc_lost_bytes)));
10433 }
10434 bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10435 }
10436 if (bbr->rc_lt_use_bw) {
10437 /* In policed mode we clamp pacing_gain to BBR_UNIT */
10438 bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
10439 }
10440 /* Google changes TSO size every cycle */
10441 if (bbr->rc_use_google)
10442 tcp_bbr_tso_size_check(bbr, cts);
10443 bbr->r_ctl.gain_epoch = cts;
10444 bbr->r_ctl.rc_bbr_state_time = cts;
10445 bbr->r_ctl.substate_pe = bbr->r_ctl.rc_pkt_epoch;
10446 }
10447
10448 static void
bbr_set_probebw_google_gains(struct tcp_bbr * bbr,uint32_t cts,uint32_t losses)10449 bbr_set_probebw_google_gains(struct tcp_bbr *bbr, uint32_t cts, uint32_t losses)
10450 {
10451 if ((bbr_state_val(bbr) == BBR_SUB_DRAIN) &&
10452 (google_allow_early_out == 1) &&
10453 (bbr->r_ctl.rc_flight_at_input <= bbr->r_ctl.rc_target_at_state)) {
10454 /* We have reached out target flight size possibly early */
10455 goto change_state;
10456 }
10457 if (TSTMP_LT(cts, bbr->r_ctl.rc_bbr_state_time)) {
10458 return;
10459 }
10460 if ((cts - bbr->r_ctl.rc_bbr_state_time) < bbr_get_rtt(bbr, BBR_RTT_PROP)) {
10461 /*
10462 * Must be a rttProp movement forward before
10463 * we can change states.
10464 */
10465 return;
10466 }
10467 if (bbr_state_val(bbr) == BBR_SUB_GAIN) {
10468 /*
10469 * The needed time has passed but for
10470 * the gain cycle extra rules apply:
10471 * 1) If we have seen loss, we exit
10472 * 2) If we have not reached the target
10473 * we stay in GAIN (gain-to-target).
10474 */
10475 if (google_consider_lost && losses)
10476 goto change_state;
10477 if (bbr->r_ctl.rc_target_at_state > bbr->r_ctl.rc_flight_at_input) {
10478 return;
10479 }
10480 }
10481 change_state:
10482 /* For gain we must reach our target, all others last 1 rttProp */
10483 bbr_substate_change(bbr, cts, __LINE__, 1);
10484 }
10485
10486 static void
bbr_set_probebw_gains(struct tcp_bbr * bbr,uint32_t cts,uint32_t losses)10487 bbr_set_probebw_gains(struct tcp_bbr *bbr, uint32_t cts, uint32_t losses)
10488 {
10489 uint32_t flight, bbr_cur_cycle_time;
10490
10491 if (bbr->rc_use_google) {
10492 bbr_set_probebw_google_gains(bbr, cts, losses);
10493 return;
10494 }
10495 if (cts == 0) {
10496 /*
10497 * Never alow cts to be 0 we
10498 * do this so we can judge if
10499 * we have set a timestamp.
10500 */
10501 cts = 1;
10502 }
10503 if (bbr_state_is_pkt_epoch)
10504 bbr_cur_cycle_time = bbr_get_rtt(bbr, BBR_RTT_PKTRTT);
10505 else
10506 bbr_cur_cycle_time = bbr_get_rtt(bbr, BBR_RTT_PROP);
10507
10508 if (bbr->r_ctl.rc_bbr_state_atflight == 0) {
10509 if (bbr_state_val(bbr) == BBR_SUB_DRAIN) {
10510 flight = ctf_flight_size(bbr->rc_tp,
10511 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
10512 if (bbr_sub_drain_slam_cwnd && bbr->rc_hit_state_1) {
10513 /* Keep it slam down */
10514 if (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state) {
10515 bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
10516 bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10517 }
10518 if (bbr_sub_drain_app_limit) {
10519 /* Go app limited if we are on a long drain */
10520 bbr->r_ctl.r_app_limited_until = (bbr->r_ctl.rc_delivered + flight);
10521 }
10522 }
10523 if (TSTMP_GT(cts, bbr->r_ctl.gain_epoch) &&
10524 (((cts - bbr->r_ctl.gain_epoch) > bbr_get_rtt(bbr, BBR_RTT_PROP)) ||
10525 (flight >= bbr->r_ctl.flightsize_at_drain))) {
10526 /*
10527 * Still here after the same time as
10528 * the gain. We need to drain harder
10529 * for the next srtt. Reduce by a set amount
10530 * the gain drop is capped at DRAIN states
10531 * value (88).
10532 */
10533 bbr->r_ctl.flightsize_at_drain = flight;
10534 if (bbr_drain_drop_mul &&
10535 bbr_drain_drop_div &&
10536 (bbr_drain_drop_mul < bbr_drain_drop_div)) {
10537 /* Use your specific drop value (def 4/5 = 20%) */
10538 bbr->r_ctl.rc_bbr_hptsi_gain *= bbr_drain_drop_mul;
10539 bbr->r_ctl.rc_bbr_hptsi_gain /= bbr_drain_drop_div;
10540 } else {
10541 /* You get drop of 20% */
10542 bbr->r_ctl.rc_bbr_hptsi_gain *= 4;
10543 bbr->r_ctl.rc_bbr_hptsi_gain /= 5;
10544 }
10545 if (bbr->r_ctl.rc_bbr_hptsi_gain <= bbr_drain_floor) {
10546 /* Reduce our gain again to the bottom */
10547 bbr->r_ctl.rc_bbr_hptsi_gain = max(bbr_drain_floor, 1);
10548 }
10549 bbr_log_exit_gain(bbr, cts, 4);
10550 /*
10551 * Extend out so we wait another
10552 * epoch before dropping again.
10553 */
10554 bbr->r_ctl.gain_epoch = cts;
10555 }
10556 if (flight <= bbr->r_ctl.rc_target_at_state) {
10557 if (bbr_sub_drain_slam_cwnd &&
10558 (bbr->rc_use_google == 0) &&
10559 (bbr->rc_tp->snd_cwnd < bbr->r_ctl.rc_saved_cwnd)) {
10560 bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_saved_cwnd;
10561 bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10562 }
10563 bbr->r_ctl.rc_bbr_state_atflight = max(cts, 1);
10564 bbr_log_exit_gain(bbr, cts, 3);
10565 }
10566 } else {
10567 /* Its a gain */
10568 if (bbr->r_ctl.rc_lost > bbr->r_ctl.bbr_lost_at_state) {
10569 bbr->r_ctl.rc_bbr_state_atflight = max(cts, 1);
10570 goto change_state;
10571 }
10572 if ((ctf_outstanding(bbr->rc_tp) >= bbr->r_ctl.rc_target_at_state) ||
10573 ((ctf_outstanding(bbr->rc_tp) + bbr->rc_tp->t_maxseg - 1) >=
10574 bbr->rc_tp->snd_wnd)) {
10575 bbr->r_ctl.rc_bbr_state_atflight = max(cts, 1);
10576 bbr_log_exit_gain(bbr, cts, 2);
10577 }
10578 }
10579 /**
10580 * We fall through and return always one of two things has
10581 * occurred.
10582 * 1) We are still not at target
10583 * <or>
10584 * 2) We reached the target and set rc_bbr_state_atflight
10585 * which means we no longer hit this block
10586 * next time we are called.
10587 */
10588 return;
10589 }
10590 change_state:
10591 if (TSTMP_LT(cts, bbr->r_ctl.rc_bbr_state_time))
10592 return;
10593 if ((cts - bbr->r_ctl.rc_bbr_state_time) < bbr_cur_cycle_time) {
10594 /* Less than a full time-period has passed */
10595 return;
10596 }
10597 if (bbr->r_ctl.rc_level_state_extra &&
10598 (bbr_state_val(bbr) > BBR_SUB_DRAIN) &&
10599 ((cts - bbr->r_ctl.rc_bbr_state_time) <
10600 (bbr_cur_cycle_time + bbr->r_ctl.rc_level_state_extra))) {
10601 /* Less than a full time-period + extra has passed */
10602 return;
10603 }
10604 if (bbr_gain_gets_extra_too &&
10605 bbr->r_ctl.rc_level_state_extra &&
10606 (bbr_state_val(bbr) == BBR_SUB_GAIN) &&
10607 ((cts - bbr->r_ctl.rc_bbr_state_time) <
10608 (bbr_cur_cycle_time + bbr->r_ctl.rc_level_state_extra))) {
10609 /* Less than a full time-period + extra has passed */
10610 return;
10611 }
10612 bbr_substate_change(bbr, cts, __LINE__, 1);
10613 }
10614
10615 static uint32_t
bbr_get_a_state_target(struct tcp_bbr * bbr,uint32_t gain)10616 bbr_get_a_state_target(struct tcp_bbr *bbr, uint32_t gain)
10617 {
10618 uint32_t mss, tar;
10619
10620 if (bbr->rc_use_google) {
10621 /* Google just uses the cwnd target */
10622 tar = bbr_get_target_cwnd(bbr, bbr_get_bw(bbr), gain);
10623 } else {
10624 mss = min((bbr->rc_tp->t_maxseg - bbr->rc_last_options),
10625 bbr->r_ctl.rc_pace_max_segs);
10626 /* Get the base cwnd with gain rounded to a mss */
10627 tar = roundup(bbr_get_raw_target_cwnd(bbr, bbr_get_bw(bbr),
10628 gain), mss);
10629 /* Make sure it is within our min */
10630 if (tar < get_min_cwnd(bbr))
10631 return (get_min_cwnd(bbr));
10632 }
10633 return (tar);
10634 }
10635
10636 static void
bbr_set_state_target(struct tcp_bbr * bbr,int line)10637 bbr_set_state_target(struct tcp_bbr *bbr, int line)
10638 {
10639 uint32_t tar, meth;
10640
10641 if ((bbr->rc_bbr_state == BBR_STATE_PROBE_RTT) &&
10642 ((bbr->r_ctl.bbr_rttprobe_gain_val == 0) || bbr->rc_use_google)) {
10643 /* Special case using old probe-rtt method */
10644 tar = bbr_rtt_probe_cwndtarg * (bbr->rc_tp->t_maxseg - bbr->rc_last_options);
10645 meth = 1;
10646 } else {
10647 /* Non-probe-rtt case and reduced probe-rtt */
10648 if ((bbr->rc_bbr_state == BBR_STATE_PROBE_BW) &&
10649 (bbr->r_ctl.rc_bbr_hptsi_gain > BBR_UNIT)) {
10650 /* For gain cycle we use the hptsi gain */
10651 tar = bbr_get_a_state_target(bbr, bbr->r_ctl.rc_bbr_hptsi_gain);
10652 meth = 2;
10653 } else if ((bbr_target_is_bbunit) || bbr->rc_use_google) {
10654 /*
10655 * If configured, or for google all other states
10656 * get BBR_UNIT.
10657 */
10658 tar = bbr_get_a_state_target(bbr, BBR_UNIT);
10659 meth = 3;
10660 } else {
10661 /*
10662 * Or we set a target based on the pacing gain
10663 * for non-google mode and default (non-configured).
10664 * Note we don't set a target goal below drain (192).
10665 */
10666 if (bbr->r_ctl.rc_bbr_hptsi_gain < bbr_hptsi_gain[BBR_SUB_DRAIN]) {
10667 tar = bbr_get_a_state_target(bbr, bbr_hptsi_gain[BBR_SUB_DRAIN]);
10668 meth = 4;
10669 } else {
10670 tar = bbr_get_a_state_target(bbr, bbr->r_ctl.rc_bbr_hptsi_gain);
10671 meth = 5;
10672 }
10673 }
10674 }
10675 bbr_log_set_of_state_target(bbr, tar, line, meth);
10676 bbr->r_ctl.rc_target_at_state = tar;
10677 }
10678
10679 static void
bbr_enter_probe_rtt(struct tcp_bbr * bbr,uint32_t cts,int32_t line)10680 bbr_enter_probe_rtt(struct tcp_bbr *bbr, uint32_t cts, int32_t line)
10681 {
10682 /* Change to probe_rtt */
10683 uint32_t time_in;
10684
10685 bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
10686 bbr->r_ctl.flightsize_at_drain = ctf_flight_size(bbr->rc_tp,
10687 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
10688 bbr->r_ctl.r_app_limited_until = (bbr->r_ctl.flightsize_at_drain
10689 + bbr->r_ctl.rc_delivered);
10690 /* Setup so we force feed the filter */
10691 if (bbr->rc_use_google || bbr_probertt_sets_rtt)
10692 bbr->rc_prtt_set_ts = 1;
10693 if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
10694 time_in = cts - bbr->r_ctl.rc_bbr_state_time;
10695 counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
10696 }
10697 bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_ENTERPROBE, 0);
10698 bbr->r_ctl.rc_rtt_shrinks = cts;
10699 bbr->r_ctl.last_in_probertt = cts;
10700 bbr->r_ctl.rc_probertt_srttchktim = cts;
10701 bbr->r_ctl.rc_bbr_state_time = cts;
10702 bbr->rc_bbr_state = BBR_STATE_PROBE_RTT;
10703 /* We need to force the filter to update */
10704
10705 if ((bbr_sub_drain_slam_cwnd) &&
10706 bbr->rc_hit_state_1 &&
10707 (bbr->rc_use_google == 0) &&
10708 (bbr_state_val(bbr) == BBR_SUB_DRAIN)) {
10709 if (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_saved_cwnd)
10710 bbr->r_ctl.rc_saved_cwnd = bbr->rc_tp->snd_cwnd;
10711 } else
10712 bbr->r_ctl.rc_saved_cwnd = bbr->rc_tp->snd_cwnd;
10713 /* Update the lost */
10714 bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
10715 if ((bbr->r_ctl.bbr_rttprobe_gain_val == 0) || bbr->rc_use_google){
10716 /* Set to the non-configurable default of 4 (PROBE_RTT_MIN) */
10717 bbr->rc_tp->snd_cwnd = bbr_rtt_probe_cwndtarg * (bbr->rc_tp->t_maxseg - bbr->rc_last_options);
10718 bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10719 bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
10720 bbr->r_ctl.rc_bbr_cwnd_gain = BBR_UNIT;
10721 bbr_log_set_of_state_target(bbr, bbr->rc_tp->snd_cwnd, __LINE__, 6);
10722 bbr->r_ctl.rc_target_at_state = bbr->rc_tp->snd_cwnd;
10723 } else {
10724 /*
10725 * We bring it down slowly by using a hptsi gain that is
10726 * probably 75%. This will slowly float down our outstanding
10727 * without tampering with the cwnd.
10728 */
10729 bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.bbr_rttprobe_gain_val;
10730 bbr->r_ctl.rc_bbr_cwnd_gain = BBR_UNIT;
10731 bbr_set_state_target(bbr, __LINE__);
10732 if (bbr_prtt_slam_cwnd &&
10733 (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state)) {
10734 bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
10735 bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10736 }
10737 }
10738 if (ctf_flight_size(bbr->rc_tp,
10739 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) <=
10740 bbr->r_ctl.rc_target_at_state) {
10741 /* We are at target */
10742 bbr->r_ctl.rc_bbr_enters_probertt = cts;
10743 } else {
10744 /* We need to come down to reach target before our time begins */
10745 bbr->r_ctl.rc_bbr_enters_probertt = 0;
10746 }
10747 bbr->r_ctl.rc_pe_of_prtt = bbr->r_ctl.rc_pkt_epoch;
10748 BBR_STAT_INC(bbr_enter_probertt);
10749 bbr_log_exit_gain(bbr, cts, 0);
10750 bbr_log_type_statechange(bbr, cts, line);
10751 }
10752
10753 static void
bbr_check_probe_rtt_limits(struct tcp_bbr * bbr,uint32_t cts)10754 bbr_check_probe_rtt_limits(struct tcp_bbr *bbr, uint32_t cts)
10755 {
10756 /*
10757 * Sanity check on probe-rtt intervals.
10758 * In crazy situations where we are competing
10759 * against new-reno flows with huge buffers
10760 * our rtt-prop interval could come to dominate
10761 * things if we can't get through a full set
10762 * of cycles, we need to adjust it.
10763 */
10764 if (bbr_can_adjust_probertt &&
10765 (bbr->rc_use_google == 0)) {
10766 uint16_t val = 0;
10767 uint32_t cur_rttp, fval, newval, baseval;
10768
10769 /* Are we to small and go into probe-rtt to often? */
10770 baseval = (bbr_get_rtt(bbr, BBR_RTT_PROP) * (BBR_SUBSTATE_COUNT + 1));
10771 cur_rttp = roundup(baseval, USECS_IN_SECOND);
10772 fval = bbr_filter_len_sec * USECS_IN_SECOND;
10773 if (bbr_is_ratio == 0) {
10774 if (fval > bbr_rtt_probe_limit)
10775 newval = cur_rttp + (fval - bbr_rtt_probe_limit);
10776 else
10777 newval = cur_rttp;
10778 } else {
10779 int mul;
10780
10781 mul = fval / bbr_rtt_probe_limit;
10782 newval = cur_rttp * mul;
10783 }
10784 if (cur_rttp > bbr->r_ctl.rc_probertt_int) {
10785 bbr->r_ctl.rc_probertt_int = cur_rttp;
10786 reset_time_small(&bbr->r_ctl.rc_rttprop, newval);
10787 val = 1;
10788 } else {
10789 /*
10790 * No adjustments were made
10791 * do we need to shrink it?
10792 */
10793 if (bbr->r_ctl.rc_probertt_int > bbr_rtt_probe_limit) {
10794 if (cur_rttp <= bbr_rtt_probe_limit) {
10795 /*
10796 * Things have calmed down lets
10797 * shrink all the way to default
10798 */
10799 bbr->r_ctl.rc_probertt_int = bbr_rtt_probe_limit;
10800 reset_time_small(&bbr->r_ctl.rc_rttprop,
10801 (bbr_filter_len_sec * USECS_IN_SECOND));
10802 cur_rttp = bbr_rtt_probe_limit;
10803 newval = (bbr_filter_len_sec * USECS_IN_SECOND);
10804 val = 2;
10805 } else {
10806 /*
10807 * Well does some adjustment make sense?
10808 */
10809 if (cur_rttp < bbr->r_ctl.rc_probertt_int) {
10810 /* We can reduce interval time some */
10811 bbr->r_ctl.rc_probertt_int = cur_rttp;
10812 reset_time_small(&bbr->r_ctl.rc_rttprop, newval);
10813 val = 3;
10814 }
10815 }
10816 }
10817 }
10818 if (val)
10819 bbr_log_rtt_shrinks(bbr, cts, cur_rttp, newval, __LINE__, BBR_RTTS_RESETS_VALUES, val);
10820 }
10821 }
10822
10823 static void
bbr_exit_probe_rtt(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t cts)10824 bbr_exit_probe_rtt(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t cts)
10825 {
10826 /* Exit probe-rtt */
10827
10828 if (tp->snd_cwnd < bbr->r_ctl.rc_saved_cwnd) {
10829 tp->snd_cwnd = bbr->r_ctl.rc_saved_cwnd;
10830 bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
10831 }
10832 bbr_log_exit_gain(bbr, cts, 1);
10833 bbr->rc_hit_state_1 = 0;
10834 bbr->r_ctl.rc_rtt_shrinks = cts;
10835 bbr->r_ctl.last_in_probertt = cts;
10836 bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_RTTPROBE, 0);
10837 bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
10838 bbr->r_ctl.r_app_limited_until = (ctf_flight_size(tp,
10839 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) +
10840 bbr->r_ctl.rc_delivered);
10841 if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
10842 uint32_t time_in;
10843
10844 time_in = cts - bbr->r_ctl.rc_bbr_state_time;
10845 counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
10846 }
10847 if (bbr->rc_filled_pipe) {
10848 /* Switch to probe_bw */
10849 bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
10850 bbr->rc_bbr_substate = bbr_pick_probebw_substate(bbr, cts);
10851 bbr->r_ctl.rc_bbr_cwnd_gain = bbr_cwnd_gain;
10852 bbr_substate_change(bbr, cts, __LINE__, 0);
10853 bbr_log_type_statechange(bbr, cts, __LINE__);
10854 } else {
10855 /* Back to startup */
10856 bbr->rc_bbr_state = BBR_STATE_STARTUP;
10857 bbr->r_ctl.rc_bbr_state_time = cts;
10858 /*
10859 * We don't want to give a complete free 3
10860 * measurements until we exit, so we use
10861 * the number of pe's we were in probe-rtt
10862 * to add to the startup_epoch. That way
10863 * we will still retain the old state.
10864 */
10865 bbr->r_ctl.rc_bbr_last_startup_epoch += (bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_pe_of_prtt);
10866 bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
10867 /* Make sure to use the lower pg when shifting back in */
10868 if (bbr->r_ctl.rc_lost &&
10869 bbr_use_lower_gain_in_startup &&
10870 (bbr->rc_use_google == 0))
10871 bbr->r_ctl.rc_bbr_hptsi_gain = bbr_startup_lower;
10872 else
10873 bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.rc_startup_pg;
10874 bbr->r_ctl.rc_bbr_cwnd_gain = bbr->r_ctl.rc_startup_pg;
10875 /* Probably not needed but set it anyway */
10876 bbr_set_state_target(bbr, __LINE__);
10877 bbr_log_type_statechange(bbr, cts, __LINE__);
10878 bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
10879 bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 0);
10880 }
10881 bbr_check_probe_rtt_limits(bbr, cts);
10882 }
10883
10884 static int32_t inline
bbr_should_enter_probe_rtt(struct tcp_bbr * bbr,uint32_t cts)10885 bbr_should_enter_probe_rtt(struct tcp_bbr *bbr, uint32_t cts)
10886 {
10887 if ((bbr->rc_past_init_win == 1) &&
10888 (bbr->rc_in_persist == 0) &&
10889 (bbr_calc_time(cts, bbr->r_ctl.rc_rtt_shrinks) >= bbr->r_ctl.rc_probertt_int)) {
10890 return (1);
10891 }
10892 if (bbr_can_force_probertt &&
10893 (bbr->rc_in_persist == 0) &&
10894 (TSTMP_GT(cts, bbr->r_ctl.last_in_probertt)) &&
10895 ((cts - bbr->r_ctl.last_in_probertt) > bbr->r_ctl.rc_probertt_int)) {
10896 return (1);
10897 }
10898 return (0);
10899 }
10900
10901 static int32_t
bbr_google_startup(struct tcp_bbr * bbr,uint32_t cts,int32_t pkt_epoch)10902 bbr_google_startup(struct tcp_bbr *bbr, uint32_t cts, int32_t pkt_epoch)
10903 {
10904 uint64_t btlbw, gain;
10905 if (pkt_epoch == 0) {
10906 /*
10907 * Need to be on a pkt-epoch to continue.
10908 */
10909 return (0);
10910 }
10911 btlbw = bbr_get_full_bw(bbr);
10912 gain = ((bbr->r_ctl.rc_bbr_lastbtlbw *
10913 (uint64_t)bbr_start_exit) / (uint64_t)100) + bbr->r_ctl.rc_bbr_lastbtlbw;
10914 if (btlbw >= gain) {
10915 bbr->r_ctl.rc_bbr_last_startup_epoch = bbr->r_ctl.rc_pkt_epoch;
10916 bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
10917 bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 3);
10918 bbr->r_ctl.rc_bbr_lastbtlbw = btlbw;
10919 }
10920 if ((bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_bbr_last_startup_epoch) >= BBR_STARTUP_EPOCHS)
10921 return (1);
10922 bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
10923 bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 8);
10924 return(0);
10925 }
10926
10927 static int32_t inline
bbr_state_startup(struct tcp_bbr * bbr,uint32_t cts,int32_t epoch,int32_t pkt_epoch)10928 bbr_state_startup(struct tcp_bbr *bbr, uint32_t cts, int32_t epoch, int32_t pkt_epoch)
10929 {
10930 /* Have we gained 25% in the last 3 packet based epoch's? */
10931 uint64_t btlbw, gain;
10932 int do_exit;
10933 int delta, rtt_gain;
10934
10935 if ((bbr->rc_tp->snd_una == bbr->rc_tp->snd_max) &&
10936 (bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time) >= bbr_rtt_probe_time)) {
10937 /*
10938 * This qualifies as a RTT_PROBE session since we drop the
10939 * data outstanding to nothing and waited more than
10940 * bbr_rtt_probe_time.
10941 */
10942 bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_WASIDLE, 0);
10943 bbr_set_reduced_rtt(bbr, cts, __LINE__);
10944 }
10945 if (bbr_should_enter_probe_rtt(bbr, cts)) {
10946 bbr_enter_probe_rtt(bbr, cts, __LINE__);
10947 return (0);
10948 }
10949 if (bbr->rc_use_google)
10950 return (bbr_google_startup(bbr, cts, pkt_epoch));
10951
10952 if ((bbr->r_ctl.rc_lost > bbr->r_ctl.rc_lost_at_startup) &&
10953 (bbr_use_lower_gain_in_startup)) {
10954 /* Drop to a lower gain 1.5 x since we saw loss */
10955 bbr->r_ctl.rc_bbr_hptsi_gain = bbr_startup_lower;
10956 }
10957 if (pkt_epoch == 0) {
10958 /*
10959 * Need to be on a pkt-epoch to continue.
10960 */
10961 return (0);
10962 }
10963 if (bbr_rtt_gain_thresh) {
10964 /*
10965 * Do we allow a flow to stay
10966 * in startup with no loss and no
10967 * gain in rtt over a set threshold?
10968 */
10969 if (bbr->r_ctl.rc_pkt_epoch_rtt &&
10970 bbr->r_ctl.startup_last_srtt &&
10971 (bbr->r_ctl.rc_pkt_epoch_rtt > bbr->r_ctl.startup_last_srtt)) {
10972 delta = bbr->r_ctl.rc_pkt_epoch_rtt - bbr->r_ctl.startup_last_srtt;
10973 rtt_gain = (delta * 100) / bbr->r_ctl.startup_last_srtt;
10974 } else
10975 rtt_gain = 0;
10976 if ((bbr->r_ctl.startup_last_srtt == 0) ||
10977 (bbr->r_ctl.rc_pkt_epoch_rtt < bbr->r_ctl.startup_last_srtt))
10978 /* First time or new lower value */
10979 bbr->r_ctl.startup_last_srtt = bbr->r_ctl.rc_pkt_epoch_rtt;
10980
10981 if ((bbr->r_ctl.rc_lost == 0) &&
10982 (rtt_gain < bbr_rtt_gain_thresh)) {
10983 /*
10984 * No loss, and we are under
10985 * our gain threhold for
10986 * increasing RTT.
10987 */
10988 if (bbr->r_ctl.rc_bbr_last_startup_epoch < bbr->r_ctl.rc_pkt_epoch)
10989 bbr->r_ctl.rc_bbr_last_startup_epoch++;
10990 bbr_log_startup_event(bbr, cts, rtt_gain,
10991 delta, bbr->r_ctl.startup_last_srtt, 10);
10992 return (0);
10993 }
10994 }
10995 if ((bbr->r_ctl.r_measurement_count == bbr->r_ctl.last_startup_measure) &&
10996 (bbr->r_ctl.rc_lost_at_startup == bbr->r_ctl.rc_lost) &&
10997 (!IN_RECOVERY(bbr->rc_tp->t_flags))) {
10998 /*
10999 * We only assess if we have a new measurement when
11000 * we have no loss and are not in recovery.
11001 * Drag up by one our last_startup epoch so we will hold
11002 * the number of non-gain we have already accumulated.
11003 */
11004 if (bbr->r_ctl.rc_bbr_last_startup_epoch < bbr->r_ctl.rc_pkt_epoch)
11005 bbr->r_ctl.rc_bbr_last_startup_epoch++;
11006 bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
11007 bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 9);
11008 return (0);
11009 }
11010 /* Case where we reduced the lost (bad retransmit) */
11011 if (bbr->r_ctl.rc_lost_at_startup > bbr->r_ctl.rc_lost)
11012 bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
11013 bbr->r_ctl.last_startup_measure = bbr->r_ctl.r_measurement_count;
11014 btlbw = bbr_get_full_bw(bbr);
11015 if (bbr->r_ctl.rc_bbr_hptsi_gain == bbr_startup_lower)
11016 gain = ((bbr->r_ctl.rc_bbr_lastbtlbw *
11017 (uint64_t)bbr_low_start_exit) / (uint64_t)100) + bbr->r_ctl.rc_bbr_lastbtlbw;
11018 else
11019 gain = ((bbr->r_ctl.rc_bbr_lastbtlbw *
11020 (uint64_t)bbr_start_exit) / (uint64_t)100) + bbr->r_ctl.rc_bbr_lastbtlbw;
11021 do_exit = 0;
11022 if (btlbw > bbr->r_ctl.rc_bbr_lastbtlbw)
11023 bbr->r_ctl.rc_bbr_lastbtlbw = btlbw;
11024 if (btlbw >= gain) {
11025 bbr->r_ctl.rc_bbr_last_startup_epoch = bbr->r_ctl.rc_pkt_epoch;
11026 /* Update the lost so we won't exit in next set of tests */
11027 bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
11028 bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
11029 bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 3);
11030 }
11031 if ((bbr->rc_loss_exit &&
11032 (bbr->r_ctl.rc_lost > bbr->r_ctl.rc_lost_at_startup) &&
11033 (bbr->r_ctl.rc_pkt_epoch_loss_rate > bbr_startup_loss_thresh)) &&
11034 ((bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_bbr_last_startup_epoch) >= BBR_STARTUP_EPOCHS)) {
11035 /*
11036 * If we had no gain, we had loss and that loss was above
11037 * our threshould, the rwnd is not constrained, and we have
11038 * had at least 3 packet epochs exit. Note that this is
11039 * switched off by sysctl. Google does not do this by the
11040 * way.
11041 */
11042 if ((ctf_flight_size(bbr->rc_tp,
11043 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) +
11044 (2 * max(bbr->r_ctl.rc_pace_max_segs, bbr->rc_tp->t_maxseg))) <= bbr->rc_tp->snd_wnd) {
11045 do_exit = 1;
11046 bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
11047 bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 4);
11048 } else {
11049 /* Just record an updated loss value */
11050 bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
11051 bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
11052 bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 5);
11053 }
11054 } else
11055 bbr->r_ctl.rc_lost_at_startup = bbr->r_ctl.rc_lost;
11056 if (((bbr->r_ctl.rc_pkt_epoch - bbr->r_ctl.rc_bbr_last_startup_epoch) >= BBR_STARTUP_EPOCHS) ||
11057 do_exit) {
11058 /* Return 1 to exit the startup state. */
11059 return (1);
11060 }
11061 /* Stay in startup */
11062 bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
11063 bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 8);
11064 return (0);
11065 }
11066
11067 static void
bbr_state_change(struct tcp_bbr * bbr,uint32_t cts,int32_t epoch,int32_t pkt_epoch,uint32_t losses)11068 bbr_state_change(struct tcp_bbr *bbr, uint32_t cts, int32_t epoch, int32_t pkt_epoch, uint32_t losses)
11069 {
11070 /*
11071 * A tick occurred in the rtt epoch do we need to do anything?
11072 */
11073 #ifdef BBR_INVARIANTS
11074 if ((bbr->rc_bbr_state != BBR_STATE_STARTUP) &&
11075 (bbr->rc_bbr_state != BBR_STATE_DRAIN) &&
11076 (bbr->rc_bbr_state != BBR_STATE_PROBE_RTT) &&
11077 (bbr->rc_bbr_state != BBR_STATE_IDLE_EXIT) &&
11078 (bbr->rc_bbr_state != BBR_STATE_PROBE_BW)) {
11079 /* Debug code? */
11080 panic("Unknown BBR state %d?\n", bbr->rc_bbr_state);
11081 }
11082 #endif
11083 if (bbr->rc_bbr_state == BBR_STATE_STARTUP) {
11084 /* Do we exit the startup state? */
11085 if (bbr_state_startup(bbr, cts, epoch, pkt_epoch)) {
11086 uint32_t time_in;
11087
11088 bbr_log_startup_event(bbr, cts, bbr->r_ctl.rc_bbr_last_startup_epoch,
11089 bbr->r_ctl.rc_lost_at_startup, bbr_start_exit, 6);
11090 bbr->rc_filled_pipe = 1;
11091 bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
11092 if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
11093 time_in = cts - bbr->r_ctl.rc_bbr_state_time;
11094 counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
11095 } else
11096 time_in = 0;
11097 if (bbr->rc_no_pacing)
11098 bbr->rc_no_pacing = 0;
11099 bbr->r_ctl.rc_bbr_state_time = cts;
11100 bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.rc_drain_pg;
11101 bbr->rc_bbr_state = BBR_STATE_DRAIN;
11102 bbr_set_state_target(bbr, __LINE__);
11103 if ((bbr->rc_use_google == 0) &&
11104 bbr_slam_cwnd_in_main_drain) {
11105 /* Here we don't have to worry about probe-rtt */
11106 bbr->r_ctl.rc_saved_cwnd = bbr->rc_tp->snd_cwnd;
11107 bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
11108 bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
11109 }
11110 bbr->r_ctl.rc_bbr_cwnd_gain = bbr_high_gain;
11111 bbr_log_type_statechange(bbr, cts, __LINE__);
11112 if (ctf_flight_size(bbr->rc_tp,
11113 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes)) <=
11114 bbr->r_ctl.rc_target_at_state) {
11115 /*
11116 * Switch to probe_bw if we are already
11117 * there
11118 */
11119 bbr->rc_bbr_substate = bbr_pick_probebw_substate(bbr, cts);
11120 bbr_substate_change(bbr, cts, __LINE__, 0);
11121 bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
11122 bbr_log_type_statechange(bbr, cts, __LINE__);
11123 }
11124 }
11125 } else if (bbr->rc_bbr_state == BBR_STATE_IDLE_EXIT) {
11126 uint32_t inflight;
11127 struct tcpcb *tp;
11128
11129 tp = bbr->rc_tp;
11130 inflight = ctf_flight_size(tp,
11131 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
11132 if (inflight >= bbr->r_ctl.rc_target_at_state) {
11133 /* We have reached a flight of the cwnd target */
11134 bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
11135 bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
11136 bbr->r_ctl.rc_bbr_cwnd_gain = BBR_UNIT;
11137 bbr_set_state_target(bbr, __LINE__);
11138 /*
11139 * Rig it so we don't do anything crazy and
11140 * start fresh with a new randomization.
11141 */
11142 bbr->r_ctl.bbr_smallest_srtt_this_state = 0xffffffff;
11143 bbr->rc_bbr_substate = BBR_SUB_LEVEL6;
11144 bbr_substate_change(bbr, cts, __LINE__, 1);
11145 }
11146 } else if (bbr->rc_bbr_state == BBR_STATE_DRAIN) {
11147 /* Has in-flight reached the bdp (or less)? */
11148 uint32_t inflight;
11149 struct tcpcb *tp;
11150
11151 tp = bbr->rc_tp;
11152 inflight = ctf_flight_size(tp,
11153 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
11154 if ((bbr->rc_use_google == 0) &&
11155 bbr_slam_cwnd_in_main_drain &&
11156 (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state)) {
11157 /*
11158 * Here we don't have to worry about probe-rtt
11159 * re-slam it, but keep it slammed down.
11160 */
11161 bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
11162 bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
11163 }
11164 if (inflight <= bbr->r_ctl.rc_target_at_state) {
11165 /* We have drained */
11166 bbr->rc_bbr_state = BBR_STATE_PROBE_BW;
11167 bbr->r_ctl.bbr_lost_at_state = bbr->r_ctl.rc_lost;
11168 if (SEQ_GT(cts, bbr->r_ctl.rc_bbr_state_time)) {
11169 uint32_t time_in;
11170
11171 time_in = cts - bbr->r_ctl.rc_bbr_state_time;
11172 counter_u64_add(bbr_state_time[bbr->rc_bbr_state], time_in);
11173 }
11174 if ((bbr->rc_use_google == 0) &&
11175 bbr_slam_cwnd_in_main_drain &&
11176 (tp->snd_cwnd < bbr->r_ctl.rc_saved_cwnd)) {
11177 /* Restore the cwnd */
11178 tp->snd_cwnd = bbr->r_ctl.rc_saved_cwnd;
11179 bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
11180 }
11181 /* Setup probe-rtt has being done now RRS-HERE */
11182 bbr->r_ctl.rc_rtt_shrinks = cts;
11183 bbr->r_ctl.last_in_probertt = cts;
11184 bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_LEAVE_DRAIN, 0);
11185 /* Randomly pick a sub-state */
11186 bbr->rc_bbr_substate = bbr_pick_probebw_substate(bbr, cts);
11187 bbr_substate_change(bbr, cts, __LINE__, 0);
11188 bbr_log_type_statechange(bbr, cts, __LINE__);
11189 }
11190 } else if (bbr->rc_bbr_state == BBR_STATE_PROBE_RTT) {
11191 uint32_t flight;
11192
11193 flight = ctf_flight_size(bbr->rc_tp,
11194 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
11195 bbr->r_ctl.r_app_limited_until = (flight + bbr->r_ctl.rc_delivered);
11196 if (((bbr->r_ctl.bbr_rttprobe_gain_val == 0) || bbr->rc_use_google) &&
11197 (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state)) {
11198 /*
11199 * We must keep cwnd at the desired MSS.
11200 */
11201 bbr->rc_tp->snd_cwnd = bbr_rtt_probe_cwndtarg * (bbr->rc_tp->t_maxseg - bbr->rc_last_options);
11202 bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
11203 } else if ((bbr_prtt_slam_cwnd) &&
11204 (bbr->rc_tp->snd_cwnd > bbr->r_ctl.rc_target_at_state)) {
11205 /* Re-slam it */
11206 bbr->rc_tp->snd_cwnd = bbr->r_ctl.rc_target_at_state;
11207 bbr_log_type_cwndupd(bbr, 0, 0, 0, 12, 0, 0, __LINE__);
11208 }
11209 if (bbr->r_ctl.rc_bbr_enters_probertt == 0) {
11210 /* Has outstanding reached our target? */
11211 if (flight <= bbr->r_ctl.rc_target_at_state) {
11212 bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_REACHTAR, 0);
11213 bbr->r_ctl.rc_bbr_enters_probertt = cts;
11214 /* If time is exactly 0, be 1usec off */
11215 if (bbr->r_ctl.rc_bbr_enters_probertt == 0)
11216 bbr->r_ctl.rc_bbr_enters_probertt = 1;
11217 if (bbr->rc_use_google == 0) {
11218 /*
11219 * Restore any lowering that as occurred to
11220 * reach here
11221 */
11222 if (bbr->r_ctl.bbr_rttprobe_gain_val)
11223 bbr->r_ctl.rc_bbr_hptsi_gain = bbr->r_ctl.bbr_rttprobe_gain_val;
11224 else
11225 bbr->r_ctl.rc_bbr_hptsi_gain = BBR_UNIT;
11226 }
11227 }
11228 if ((bbr->r_ctl.rc_bbr_enters_probertt == 0) &&
11229 (bbr->rc_use_google == 0) &&
11230 bbr->r_ctl.bbr_rttprobe_gain_val &&
11231 (((cts - bbr->r_ctl.rc_probertt_srttchktim) > bbr_get_rtt(bbr, bbr_drain_rtt)) ||
11232 (flight >= bbr->r_ctl.flightsize_at_drain))) {
11233 /*
11234 * We have doddled with our current hptsi
11235 * gain an srtt and have still not made it
11236 * to target, or we have increased our flight.
11237 * Lets reduce the gain by xx%
11238 * flooring the reduce at DRAIN (based on
11239 * mul/div)
11240 */
11241 int red;
11242
11243 bbr->r_ctl.flightsize_at_drain = flight;
11244 bbr->r_ctl.rc_probertt_srttchktim = cts;
11245 red = max((bbr->r_ctl.bbr_rttprobe_gain_val / 10), 1);
11246 if ((bbr->r_ctl.rc_bbr_hptsi_gain - red) > max(bbr_drain_floor, 1)) {
11247 /* Reduce our gain again */
11248 bbr->r_ctl.rc_bbr_hptsi_gain -= red;
11249 bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_SHRINK_PG, 0);
11250 } else if (bbr->r_ctl.rc_bbr_hptsi_gain > max(bbr_drain_floor, 1)) {
11251 /* one more chance before we give up */
11252 bbr->r_ctl.rc_bbr_hptsi_gain = max(bbr_drain_floor, 1);
11253 bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_SHRINK_PG_FINAL, 0);
11254 } else {
11255 /* At the very bottom */
11256 bbr->r_ctl.rc_bbr_hptsi_gain = max((bbr_drain_floor-1), 1);
11257 }
11258 }
11259 }
11260 if (bbr->r_ctl.rc_bbr_enters_probertt &&
11261 (TSTMP_GT(cts, bbr->r_ctl.rc_bbr_enters_probertt)) &&
11262 ((cts - bbr->r_ctl.rc_bbr_enters_probertt) >= bbr_rtt_probe_time)) {
11263 /* Time to exit probe RTT normally */
11264 bbr_exit_probe_rtt(bbr->rc_tp, bbr, cts);
11265 }
11266 } else if (bbr->rc_bbr_state == BBR_STATE_PROBE_BW) {
11267 if ((bbr->rc_tp->snd_una == bbr->rc_tp->snd_max) &&
11268 (bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time) >= bbr_rtt_probe_time)) {
11269 /*
11270 * This qualifies as a RTT_PROBE session since we
11271 * drop the data outstanding to nothing and waited
11272 * more than bbr_rtt_probe_time.
11273 */
11274 bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_WASIDLE, 0);
11275 bbr_set_reduced_rtt(bbr, cts, __LINE__);
11276 }
11277 if (bbr_should_enter_probe_rtt(bbr, cts)) {
11278 bbr_enter_probe_rtt(bbr, cts, __LINE__);
11279 } else {
11280 bbr_set_probebw_gains(bbr, cts, losses);
11281 }
11282 }
11283 }
11284
11285 static void
bbr_check_bbr_for_state(struct tcp_bbr * bbr,uint32_t cts,int32_t line,uint32_t losses)11286 bbr_check_bbr_for_state(struct tcp_bbr *bbr, uint32_t cts, int32_t line, uint32_t losses)
11287 {
11288 int32_t epoch = 0;
11289
11290 if ((cts - bbr->r_ctl.rc_rcv_epoch_start) >= bbr_get_rtt(bbr, BBR_RTT_PROP)) {
11291 bbr_set_epoch(bbr, cts, line);
11292 /* At each epoch doe lt bw sampling */
11293 epoch = 1;
11294 }
11295 bbr_state_change(bbr, cts, epoch, bbr->rc_is_pkt_epoch_now, losses);
11296 }
11297
11298 static int
bbr_do_segment_nounlock(struct tcpcb * tp,struct mbuf * m,struct tcphdr * th,int32_t drop_hdrlen,int32_t tlen,uint8_t iptos,int32_t nxt_pkt,struct timeval * tv)11299 bbr_do_segment_nounlock(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
11300 int32_t drop_hdrlen, int32_t tlen, uint8_t iptos, int32_t nxt_pkt,
11301 struct timeval *tv)
11302 {
11303 struct inpcb *inp = tptoinpcb(tp);
11304 struct socket *so = tptosocket(tp);
11305 int32_t thflags, retval;
11306 uint32_t cts, lcts;
11307 uint32_t tiwin;
11308 struct tcpopt to;
11309 struct tcp_bbr *bbr;
11310 struct bbr_sendmap *rsm;
11311 struct timeval ltv;
11312 int32_t did_out = 0;
11313 uint16_t nsegs;
11314 int32_t prev_state;
11315 uint32_t lost;
11316
11317 nsegs = max(1, m->m_pkthdr.lro_nsegs);
11318 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
11319 /* add in our stats */
11320 kern_prefetch(bbr, &prev_state);
11321 prev_state = 0;
11322 thflags = tcp_get_flags(th);
11323 /*
11324 * If this is either a state-changing packet or current state isn't
11325 * established, we require a write lock on tcbinfo. Otherwise, we
11326 * allow the tcbinfo to be in either alocked or unlocked, as the
11327 * caller may have unnecessarily acquired a write lock due to a
11328 * race.
11329 */
11330 INP_WLOCK_ASSERT(tptoinpcb(tp));
11331 KASSERT(tp->t_state > TCPS_LISTEN, ("%s: TCPS_LISTEN",
11332 __func__));
11333 KASSERT(tp->t_state != TCPS_TIME_WAIT, ("%s: TCPS_TIME_WAIT",
11334 __func__));
11335
11336 tp->t_rcvtime = ticks;
11337 /*
11338 * Unscale the window into a 32-bit value. For the SYN_SENT state
11339 * the scale is zero.
11340 */
11341 tiwin = th->th_win << tp->snd_scale;
11342 #ifdef STATS
11343 stats_voi_update_abs_ulong(tp->t_stats, VOI_TCP_FRWIN, tiwin);
11344 #endif
11345
11346 if (m->m_flags & M_TSTMP) {
11347 /* Prefer the hardware timestamp if present */
11348 struct timespec ts;
11349
11350 mbuf_tstmp2timespec(m, &ts);
11351 bbr->rc_tv.tv_sec = ts.tv_sec;
11352 bbr->rc_tv.tv_usec = ts.tv_nsec / 1000;
11353 bbr->r_ctl.rc_rcvtime = cts = tcp_tv_to_usectick(&bbr->rc_tv);
11354 } else if (m->m_flags & M_TSTMP_LRO) {
11355 /* Next the arrival timestamp */
11356 struct timespec ts;
11357
11358 mbuf_tstmp2timespec(m, &ts);
11359 bbr->rc_tv.tv_sec = ts.tv_sec;
11360 bbr->rc_tv.tv_usec = ts.tv_nsec / 1000;
11361 bbr->r_ctl.rc_rcvtime = cts = tcp_tv_to_usectick(&bbr->rc_tv);
11362 } else {
11363 /*
11364 * Ok just get the current time.
11365 */
11366 bbr->r_ctl.rc_rcvtime = lcts = cts = tcp_get_usecs(&bbr->rc_tv);
11367 }
11368 /*
11369 * Parse options on any incoming segment.
11370 */
11371 tcp_dooptions(&to, (u_char *)(th + 1),
11372 (th->th_off << 2) - sizeof(struct tcphdr),
11373 (thflags & TH_SYN) ? TO_SYN : 0);
11374 if (tp->t_flags2 & TF2_PROC_SACK_PROHIBIT) {
11375 /*
11376 * We don't look at sack's from the
11377 * peer because the MSS is too small which
11378 * can subject us to an attack.
11379 */
11380 to.to_flags &= ~TOF_SACK;
11381 }
11382 /*
11383 * If timestamps were negotiated during SYN/ACK and a
11384 * segment without a timestamp is received, silently drop
11385 * the segment, unless it is a RST segment or missing timestamps are
11386 * tolerated.
11387 * See section 3.2 of RFC 7323.
11388 */
11389 if ((tp->t_flags & TF_RCVD_TSTMP) && !(to.to_flags & TOF_TS) &&
11390 ((thflags & TH_RST) == 0) && (V_tcp_tolerate_missing_ts == 0)) {
11391 retval = 0;
11392 m_freem(m);
11393 goto done_with_input;
11394 }
11395 /*
11396 * If echoed timestamp is later than the current time, fall back to
11397 * non RFC1323 RTT calculation. Normalize timestamp if syncookies
11398 * were used when this connection was established.
11399 */
11400 if ((to.to_flags & TOF_TS) && (to.to_tsecr != 0)) {
11401 to.to_tsecr -= tp->ts_offset;
11402 if (TSTMP_GT(to.to_tsecr, tcp_tv_to_mssectick(&bbr->rc_tv)))
11403 to.to_tsecr = 0;
11404 }
11405 /*
11406 * If its the first time in we need to take care of options and
11407 * verify we can do SACK for rack!
11408 */
11409 if (bbr->r_state == 0) {
11410 /*
11411 * Process options only when we get SYN/ACK back. The SYN
11412 * case for incoming connections is handled in tcp_syncache.
11413 * According to RFC1323 the window field in a SYN (i.e., a
11414 * <SYN> or <SYN,ACK>) segment itself is never scaled. XXX
11415 * this is traditional behavior, may need to be cleaned up.
11416 */
11417 if (bbr->rc_inp == NULL) {
11418 bbr->rc_inp = inp;
11419 }
11420 /*
11421 * We need to init rc_inp here since its not init'd when
11422 * bbr_init is called
11423 */
11424 if (tp->t_state == TCPS_SYN_SENT && (thflags & TH_SYN)) {
11425 if ((to.to_flags & TOF_SCALE) &&
11426 (tp->t_flags & TF_REQ_SCALE)) {
11427 tp->t_flags |= TF_RCVD_SCALE;
11428 tp->snd_scale = to.to_wscale;
11429 } else
11430 tp->t_flags &= ~TF_REQ_SCALE;
11431 /*
11432 * Initial send window. It will be updated with the
11433 * next incoming segment to the scaled value.
11434 */
11435 tp->snd_wnd = th->th_win;
11436 if ((to.to_flags & TOF_TS) &&
11437 (tp->t_flags & TF_REQ_TSTMP)) {
11438 tp->t_flags |= TF_RCVD_TSTMP;
11439 tp->ts_recent = to.to_tsval;
11440 tp->ts_recent_age = tcp_tv_to_mssectick(&bbr->rc_tv);
11441 } else
11442 tp->t_flags &= ~TF_REQ_TSTMP;
11443 if (to.to_flags & TOF_MSS)
11444 tcp_mss(tp, to.to_mss);
11445 if ((tp->t_flags & TF_SACK_PERMIT) &&
11446 (to.to_flags & TOF_SACKPERM) == 0)
11447 tp->t_flags &= ~TF_SACK_PERMIT;
11448 if (tp->t_flags & TF_FASTOPEN) {
11449 if (to.to_flags & TOF_FASTOPEN) {
11450 uint16_t mss;
11451
11452 if (to.to_flags & TOF_MSS)
11453 mss = to.to_mss;
11454 else
11455 if ((inp->inp_vflag & INP_IPV6) != 0)
11456 mss = TCP6_MSS;
11457 else
11458 mss = TCP_MSS;
11459 tcp_fastopen_update_cache(tp, mss,
11460 to.to_tfo_len, to.to_tfo_cookie);
11461 } else
11462 tcp_fastopen_disable_path(tp);
11463 }
11464 }
11465 /*
11466 * At this point we are at the initial call. Here we decide
11467 * if we are doing RACK or not. We do this by seeing if
11468 * TF_SACK_PERMIT is set, if not rack is *not* possible and
11469 * we switch to the default code.
11470 */
11471 if ((tp->t_flags & TF_SACK_PERMIT) == 0) {
11472 /* Bail */
11473 tcp_switch_back_to_default(tp);
11474 (*tp->t_fb->tfb_tcp_do_segment)(tp, m, th, drop_hdrlen,
11475 tlen, iptos);
11476 return (1);
11477 }
11478 /* Set the flag */
11479 bbr->r_is_v6 = (inp->inp_vflag & INP_IPV6) != 0;
11480 tcp_set_hpts(tp);
11481 sack_filter_clear(&bbr->r_ctl.bbr_sf, th->th_ack);
11482 }
11483 if (thflags & TH_ACK) {
11484 /* Track ack types */
11485 if (to.to_flags & TOF_SACK)
11486 BBR_STAT_INC(bbr_acks_with_sacks);
11487 else
11488 BBR_STAT_INC(bbr_plain_acks);
11489 }
11490 /*
11491 * This is the one exception case where we set the rack state
11492 * always. All other times (timers etc) we must have a rack-state
11493 * set (so we assure we have done the checks above for SACK).
11494 */
11495 if (thflags & TH_FIN)
11496 tcp_log_end_status(tp, TCP_EI_STATUS_CLIENT_FIN);
11497 if (bbr->r_state != tp->t_state)
11498 bbr_set_state(tp, bbr, tiwin);
11499
11500 if (SEQ_GT(th->th_ack, tp->snd_una) && (rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map)) != NULL)
11501 kern_prefetch(rsm, &prev_state);
11502 prev_state = bbr->r_state;
11503 bbr->rc_ack_was_delayed = 0;
11504 lost = bbr->r_ctl.rc_lost;
11505 bbr->rc_is_pkt_epoch_now = 0;
11506 if (m->m_flags & (M_TSTMP|M_TSTMP_LRO)) {
11507 /* Get the real time into lcts and figure the real delay */
11508 lcts = tcp_get_usecs(<v);
11509 if (TSTMP_GT(lcts, cts)) {
11510 bbr->r_ctl.rc_ack_hdwr_delay = lcts - cts;
11511 bbr->rc_ack_was_delayed = 1;
11512 if (TSTMP_GT(bbr->r_ctl.rc_ack_hdwr_delay,
11513 bbr->r_ctl.highest_hdwr_delay))
11514 bbr->r_ctl.highest_hdwr_delay = bbr->r_ctl.rc_ack_hdwr_delay;
11515 } else {
11516 bbr->r_ctl.rc_ack_hdwr_delay = 0;
11517 bbr->rc_ack_was_delayed = 0;
11518 }
11519 } else {
11520 bbr->r_ctl.rc_ack_hdwr_delay = 0;
11521 bbr->rc_ack_was_delayed = 0;
11522 }
11523 bbr_log_ack_event(bbr, th, &to, tlen, nsegs, cts, nxt_pkt, m);
11524 if ((thflags & TH_SYN) && (thflags & TH_FIN) && V_drop_synfin) {
11525 retval = 0;
11526 m_freem(m);
11527 goto done_with_input;
11528 }
11529 /*
11530 * If a segment with the ACK-bit set arrives in the SYN-SENT state
11531 * check SEQ.ACK first as described on page 66 of RFC 793, section 3.9.
11532 */
11533 if ((tp->t_state == TCPS_SYN_SENT) && (thflags & TH_ACK) &&
11534 (SEQ_LEQ(th->th_ack, tp->iss) || SEQ_GT(th->th_ack, tp->snd_max))) {
11535 tcp_log_end_status(tp, TCP_EI_STATUS_RST_IN_FRONT);
11536 ctf_do_dropwithreset_conn(m, tp, th, BANDLIM_RST_OPENPORT, tlen);
11537 return (1);
11538 }
11539 if (tiwin > bbr->r_ctl.rc_high_rwnd)
11540 bbr->r_ctl.rc_high_rwnd = tiwin;
11541 bbr->r_ctl.rc_flight_at_input = ctf_flight_size(tp,
11542 (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
11543 bbr->rtt_valid = 0;
11544 if (to.to_flags & TOF_TS) {
11545 bbr->rc_ts_valid = 1;
11546 bbr->r_ctl.last_inbound_ts = to.to_tsval;
11547 } else {
11548 bbr->rc_ts_valid = 0;
11549 bbr->r_ctl.last_inbound_ts = 0;
11550 }
11551 retval = (*bbr->r_substate) (m, th, so,
11552 tp, &to, drop_hdrlen,
11553 tlen, tiwin, thflags, nxt_pkt, iptos);
11554 if (nxt_pkt == 0)
11555 BBR_STAT_INC(bbr_rlock_left_ret0);
11556 else
11557 BBR_STAT_INC(bbr_rlock_left_ret1);
11558 if (retval == 0) {
11559 /*
11560 * If retval is 1 the tcb is unlocked and most likely the tp
11561 * is gone.
11562 */
11563 INP_WLOCK_ASSERT(inp);
11564 tcp_bbr_xmit_timer_commit(bbr, tp, cts);
11565 if (bbr->rc_is_pkt_epoch_now)
11566 bbr_set_pktepoch(bbr, cts, __LINE__);
11567 bbr_check_bbr_for_state(bbr, cts, __LINE__, (bbr->r_ctl.rc_lost - lost));
11568 if (nxt_pkt == 0) {
11569 if ((bbr->r_wanted_output != 0) ||
11570 (tp->t_flags & TF_ACKNOW)) {
11571
11572 bbr->rc_output_starts_timer = 0;
11573 did_out = 1;
11574 if (tcp_output(tp) < 0)
11575 return (1);
11576 } else
11577 bbr_start_hpts_timer(bbr, tp, cts, 6, 0, 0);
11578 }
11579 if ((nxt_pkt == 0) &&
11580 ((bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK) == 0) &&
11581 (SEQ_GT(tp->snd_max, tp->snd_una) ||
11582 (tp->t_flags & TF_DELACK) ||
11583 ((V_tcp_always_keepalive || bbr->rc_inp->inp_socket->so_options & SO_KEEPALIVE) &&
11584 (tp->t_state <= TCPS_CLOSING)))) {
11585 /*
11586 * We could not send (probably in the hpts but
11587 * stopped the timer)?
11588 */
11589 if ((tp->snd_max == tp->snd_una) &&
11590 ((tp->t_flags & TF_DELACK) == 0) &&
11591 (tcp_in_hpts(tp)) &&
11592 (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
11593 /*
11594 * keep alive not needed if we are hptsi
11595 * output yet
11596 */
11597 ;
11598 } else {
11599 if (tcp_in_hpts(tp)) {
11600 tcp_hpts_remove(tp);
11601 if ((bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
11602 (TSTMP_GT(lcts, bbr->rc_pacer_started))) {
11603 uint32_t del;
11604
11605 del = lcts - bbr->rc_pacer_started;
11606 if (bbr->r_ctl.rc_last_delay_val > del) {
11607 BBR_STAT_INC(bbr_force_timer_start);
11608 bbr->r_ctl.rc_last_delay_val -= del;
11609 bbr->rc_pacer_started = lcts;
11610 } else {
11611 /* We are late */
11612 bbr->r_ctl.rc_last_delay_val = 0;
11613 BBR_STAT_INC(bbr_force_output);
11614 if (tcp_output(tp) < 0)
11615 return (1);
11616 }
11617 }
11618 }
11619 bbr_start_hpts_timer(bbr, tp, cts, 8, bbr->r_ctl.rc_last_delay_val,
11620 0);
11621 }
11622 } else if ((bbr->rc_output_starts_timer == 0) && (nxt_pkt == 0)) {
11623 /* Do we have the correct timer running? */
11624 bbr_timer_audit(tp, bbr, lcts, &so->so_snd);
11625 }
11626 /* Clear the flag, it may have been cleared by output but we may not have */
11627 if ((nxt_pkt == 0) && (tp->t_flags2 & TF2_HPTS_CALLS))
11628 tp->t_flags2 &= ~TF2_HPTS_CALLS;
11629 /* Do we have a new state */
11630 if (bbr->r_state != tp->t_state)
11631 bbr_set_state(tp, bbr, tiwin);
11632 done_with_input:
11633 bbr_log_doseg_done(bbr, cts, nxt_pkt, did_out);
11634 if (did_out)
11635 bbr->r_wanted_output = 0;
11636 }
11637 return (retval);
11638 }
11639
11640 static void
bbr_do_segment(struct tcpcb * tp,struct mbuf * m,struct tcphdr * th,int32_t drop_hdrlen,int32_t tlen,uint8_t iptos)11641 bbr_do_segment(struct tcpcb *tp, struct mbuf *m, struct tcphdr *th,
11642 int32_t drop_hdrlen, int32_t tlen, uint8_t iptos)
11643 {
11644 struct timeval tv;
11645 int retval;
11646
11647 /* First lets see if we have old packets */
11648 if (!STAILQ_EMPTY(&tp->t_inqueue)) {
11649 if (ctf_do_queued_segments(tp, 1)) {
11650 m_freem(m);
11651 return;
11652 }
11653 }
11654 if (m->m_flags & M_TSTMP_LRO) {
11655 mbuf_tstmp2timeval(m, &tv);
11656 } else {
11657 /* Should not be should we kassert instead? */
11658 tcp_get_usecs(&tv);
11659 }
11660 retval = bbr_do_segment_nounlock(tp, m, th, drop_hdrlen, tlen, iptos,
11661 0, &tv);
11662 if (retval == 0) {
11663 INP_WUNLOCK(tptoinpcb(tp));
11664 }
11665 }
11666
11667 /*
11668 * Return how much data can be sent without violating the
11669 * cwnd or rwnd.
11670 */
11671
11672 static inline uint32_t
bbr_what_can_we_send(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t sendwin,uint32_t avail,int32_t sb_offset,uint32_t cts)11673 bbr_what_can_we_send(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t sendwin,
11674 uint32_t avail, int32_t sb_offset, uint32_t cts)
11675 {
11676 uint32_t len;
11677
11678 if (ctf_outstanding(tp) >= tp->snd_wnd) {
11679 /* We never want to go over our peers rcv-window */
11680 len = 0;
11681 } else {
11682 uint32_t flight;
11683
11684 flight = ctf_flight_size(tp, (bbr->r_ctl.rc_sacked + bbr->r_ctl.rc_lost_bytes));
11685 if (flight >= sendwin) {
11686 /*
11687 * We have in flight what we are allowed by cwnd (if
11688 * it was rwnd blocking it would have hit above out
11689 * >= tp->snd_wnd).
11690 */
11691 return (0);
11692 }
11693 len = sendwin - flight;
11694 if ((len + ctf_outstanding(tp)) > tp->snd_wnd) {
11695 /* We would send too much (beyond the rwnd) */
11696 len = tp->snd_wnd - ctf_outstanding(tp);
11697 }
11698 if ((len + sb_offset) > avail) {
11699 /*
11700 * We don't have that much in the SB, how much is
11701 * there?
11702 */
11703 len = avail - sb_offset;
11704 }
11705 }
11706 return (len);
11707 }
11708
11709 static inline void
bbr_do_send_accounting(struct tcpcb * tp,struct tcp_bbr * bbr,struct bbr_sendmap * rsm,int32_t len,int32_t error)11710 bbr_do_send_accounting(struct tcpcb *tp, struct tcp_bbr *bbr, struct bbr_sendmap *rsm, int32_t len, int32_t error)
11711 {
11712 if (error) {
11713 return;
11714 }
11715 if (rsm) {
11716 if (rsm->r_flags & BBR_TLP) {
11717 /*
11718 * TLP should not count in retran count, but in its
11719 * own bin
11720 */
11721 KMOD_TCPSTAT_INC(tcps_tlpresends);
11722 KMOD_TCPSTAT_ADD(tcps_tlpresend_bytes, len);
11723 } else {
11724 /* Retransmit */
11725 tp->t_sndrexmitpack++;
11726 KMOD_TCPSTAT_INC(tcps_sndrexmitpack);
11727 KMOD_TCPSTAT_ADD(tcps_sndrexmitbyte, len);
11728 #ifdef STATS
11729 stats_voi_update_abs_u32(tp->t_stats, VOI_TCP_RETXPB,
11730 len);
11731 #endif
11732 }
11733 /*
11734 * Logs in 0 - 8, 8 is all non probe_bw states 0-7 is
11735 * sub-state
11736 */
11737 counter_u64_add(bbr_state_lost[rsm->r_bbr_state], len);
11738 if (bbr->rc_bbr_state != BBR_STATE_PROBE_BW) {
11739 /* Non probe_bw log in 1, 2, or 4. */
11740 counter_u64_add(bbr_state_resend[bbr->rc_bbr_state], len);
11741 } else {
11742 /*
11743 * Log our probe state 3, and log also 5-13 to show
11744 * us the recovery sub-state for the send. This
11745 * means that 3 == (5+6+7+8+9+10+11+12+13)
11746 */
11747 counter_u64_add(bbr_state_resend[BBR_STATE_PROBE_BW], len);
11748 counter_u64_add(bbr_state_resend[(bbr_state_val(bbr) + 5)], len);
11749 }
11750 /* Place in both 16's the totals of retransmitted */
11751 counter_u64_add(bbr_state_lost[16], len);
11752 counter_u64_add(bbr_state_resend[16], len);
11753 /* Place in 17's the total sent */
11754 counter_u64_add(bbr_state_resend[17], len);
11755 counter_u64_add(bbr_state_lost[17], len);
11756
11757 } else {
11758 /* New sends */
11759 KMOD_TCPSTAT_INC(tcps_sndpack);
11760 KMOD_TCPSTAT_ADD(tcps_sndbyte, len);
11761 /* Place in 17's the total sent */
11762 counter_u64_add(bbr_state_resend[17], len);
11763 counter_u64_add(bbr_state_lost[17], len);
11764 #ifdef STATS
11765 stats_voi_update_abs_u64(tp->t_stats, VOI_TCP_TXPB,
11766 len);
11767 #endif
11768 }
11769 }
11770
11771 static void
bbr_cwnd_limiting(struct tcpcb * tp,struct tcp_bbr * bbr,uint32_t in_level)11772 bbr_cwnd_limiting(struct tcpcb *tp, struct tcp_bbr *bbr, uint32_t in_level)
11773 {
11774 if (bbr->rc_filled_pipe && bbr_target_cwnd_mult_limit && (bbr->rc_use_google == 0)) {
11775 /*
11776 * Limit the cwnd to not be above N x the target plus whats
11777 * is outstanding. The target is based on the current b/w
11778 * estimate.
11779 */
11780 uint32_t target;
11781
11782 target = bbr_get_target_cwnd(bbr, bbr_get_bw(bbr), BBR_UNIT);
11783 target += ctf_outstanding(tp);
11784 target *= bbr_target_cwnd_mult_limit;
11785 if (tp->snd_cwnd > target)
11786 tp->snd_cwnd = target;
11787 bbr_log_type_cwndupd(bbr, 0, 0, 0, 10, 0, 0, __LINE__);
11788 }
11789 }
11790
11791 static int
bbr_window_update_needed(struct tcpcb * tp,struct socket * so,uint32_t recwin,int32_t maxseg)11792 bbr_window_update_needed(struct tcpcb *tp, struct socket *so, uint32_t recwin, int32_t maxseg)
11793 {
11794 /*
11795 * "adv" is the amount we could increase the window, taking into
11796 * account that we are limited by TCP_MAXWIN << tp->rcv_scale.
11797 */
11798 int32_t adv;
11799 int32_t oldwin;
11800
11801 adv = recwin;
11802 if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt)) {
11803 oldwin = (tp->rcv_adv - tp->rcv_nxt);
11804 if (adv > oldwin)
11805 adv -= oldwin;
11806 else {
11807 /* We can't increase the window */
11808 adv = 0;
11809 }
11810 } else
11811 oldwin = 0;
11812
11813 /*
11814 * If the new window size ends up being the same as or less
11815 * than the old size when it is scaled, then don't force
11816 * a window update.
11817 */
11818 if (oldwin >> tp->rcv_scale >= (adv + oldwin) >> tp->rcv_scale)
11819 return (0);
11820
11821 if (adv >= (2 * maxseg) &&
11822 (adv >= (so->so_rcv.sb_hiwat / 4) ||
11823 recwin <= (so->so_rcv.sb_hiwat / 8) ||
11824 so->so_rcv.sb_hiwat <= 8 * maxseg)) {
11825 return (1);
11826 }
11827 if (2 * adv >= (int32_t) so->so_rcv.sb_hiwat)
11828 return (1);
11829 return (0);
11830 }
11831
11832 /*
11833 * Return 0 on success and a errno on failure to send.
11834 * Note that a 0 return may not mean we sent anything
11835 * if the TCB was on the hpts. A non-zero return
11836 * does indicate the error we got from ip[6]_output.
11837 */
11838 static int
bbr_output_wtime(struct tcpcb * tp,const struct timeval * tv)11839 bbr_output_wtime(struct tcpcb *tp, const struct timeval *tv)
11840 {
11841 struct socket *so;
11842 int32_t len;
11843 uint32_t cts;
11844 uint32_t recwin, sendwin;
11845 int32_t sb_offset;
11846 int32_t flags, abandon, error = 0;
11847 struct tcp_log_buffer *lgb;
11848 struct mbuf *m;
11849 struct mbuf *mb;
11850 uint32_t if_hw_tsomaxsegcount = 0;
11851 uint32_t if_hw_tsomaxsegsize = 0;
11852 uint32_t if_hw_tsomax = 0;
11853 struct ip *ip = NULL;
11854 struct tcp_bbr *bbr;
11855 struct tcphdr *th;
11856 struct udphdr *udp = NULL;
11857 u_char opt[TCP_MAXOLEN];
11858 unsigned ipoptlen, optlen, hdrlen;
11859 unsigned ulen;
11860 uint32_t bbr_seq;
11861 uint32_t delay_calc=0;
11862 uint8_t doing_tlp = 0;
11863 uint8_t local_options;
11864 #ifdef BBR_INVARIANTS
11865 uint8_t doing_retran_from = 0;
11866 uint8_t picked_up_retran = 0;
11867 #endif
11868 uint8_t wanted_cookie = 0;
11869 uint8_t more_to_rxt=0;
11870 int32_t prefetch_so_done = 0;
11871 int32_t prefetch_rsm = 0;
11872 uint32_t tot_len = 0;
11873 uint32_t maxseg, pace_max_segs, p_maxseg;
11874 int32_t csum_flags = 0;
11875 int32_t hw_tls;
11876 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
11877 unsigned ipsec_optlen = 0;
11878
11879 #endif
11880 volatile int32_t sack_rxmit;
11881 struct bbr_sendmap *rsm = NULL;
11882 int32_t tso, mtu;
11883 struct tcpopt to;
11884 int32_t slot = 0;
11885 struct inpcb *inp;
11886 struct sockbuf *sb;
11887 bool hpts_calling;
11888 #ifdef INET6
11889 struct ip6_hdr *ip6 = NULL;
11890 int32_t isipv6;
11891 #endif
11892 uint8_t app_limited = BBR_JR_SENT_DATA;
11893 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
11894 /* We take a cache hit here */
11895 memcpy(&bbr->rc_tv, tv, sizeof(struct timeval));
11896 cts = tcp_tv_to_usectick(&bbr->rc_tv);
11897 inp = bbr->rc_inp;
11898 hpts_calling = !!(tp->t_flags2 & TF2_HPTS_CALLS);
11899 tp->t_flags2 &= ~TF2_HPTS_CALLS;
11900 so = inp->inp_socket;
11901 sb = &so->so_snd;
11902 if (tp->t_nic_ktls_xmit)
11903 hw_tls = 1;
11904 else
11905 hw_tls = 0;
11906 kern_prefetch(sb, &maxseg);
11907 maxseg = tp->t_maxseg - bbr->rc_last_options;
11908 if (bbr_minseg(bbr) < maxseg) {
11909 tcp_bbr_tso_size_check(bbr, cts);
11910 }
11911 /* Remove any flags that indicate we are pacing on the inp */
11912 pace_max_segs = bbr->r_ctl.rc_pace_max_segs;
11913 p_maxseg = min(maxseg, pace_max_segs);
11914 INP_WLOCK_ASSERT(inp);
11915 #ifdef TCP_OFFLOAD
11916 if (tp->t_flags & TF_TOE)
11917 return (tcp_offload_output(tp));
11918 #endif
11919
11920 #ifdef INET6
11921 if (bbr->r_state) {
11922 /* Use the cache line loaded if possible */
11923 isipv6 = bbr->r_is_v6;
11924 } else {
11925 isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
11926 }
11927 #endif
11928 if (((bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) == 0) &&
11929 tcp_in_hpts(tp)) {
11930 /*
11931 * We are on the hpts for some timer but not hptsi output.
11932 * Possibly remove from the hpts so we can send/recv etc.
11933 */
11934 if ((tp->t_flags & TF_ACKNOW) == 0) {
11935 /*
11936 * No immediate demand right now to send an ack, but
11937 * the user may have read, making room for new data
11938 * (a window update). If so we may want to cancel
11939 * whatever timer is running (KEEP/DEL-ACK?) and
11940 * continue to send out a window update. Or we may
11941 * have gotten more data into the socket buffer to
11942 * send.
11943 */
11944 recwin = lmin(lmax(sbspace(&so->so_rcv), 0),
11945 (long)TCP_MAXWIN << tp->rcv_scale);
11946 if ((bbr_window_update_needed(tp, so, recwin, maxseg) == 0) &&
11947 ((tcp_outflags[tp->t_state] & TH_RST) == 0) &&
11948 ((sbavail(sb) + ((tcp_outflags[tp->t_state] & TH_FIN) ? 1 : 0)) <=
11949 (tp->snd_max - tp->snd_una))) {
11950 /*
11951 * Nothing new to send and no window update
11952 * is needed to send. Lets just return and
11953 * let the timer-run off.
11954 */
11955 return (0);
11956 }
11957 }
11958 tcp_hpts_remove(tp);
11959 bbr_timer_cancel(bbr, __LINE__, cts);
11960 }
11961 if (bbr->r_ctl.rc_last_delay_val) {
11962 /* Calculate a rough delay for early escape to sending */
11963 if (SEQ_GT(cts, bbr->rc_pacer_started))
11964 delay_calc = cts - bbr->rc_pacer_started;
11965 if (delay_calc >= bbr->r_ctl.rc_last_delay_val)
11966 delay_calc -= bbr->r_ctl.rc_last_delay_val;
11967 else
11968 delay_calc = 0;
11969 }
11970 /* Mark that we have called bbr_output(). */
11971 if ((bbr->r_timer_override) ||
11972 (tp->t_state < TCPS_ESTABLISHED)) {
11973 /* Timeouts or early states are exempt */
11974 if (tcp_in_hpts(tp))
11975 tcp_hpts_remove(tp);
11976 } else if (tcp_in_hpts(tp)) {
11977 if ((bbr->r_ctl.rc_last_delay_val) &&
11978 (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) &&
11979 delay_calc) {
11980 /*
11981 * We were being paced for output and the delay has
11982 * already exceeded when we were supposed to be
11983 * called, lets go ahead and pull out of the hpts
11984 * and call output.
11985 */
11986 counter_u64_add(bbr_out_size[TCP_MSS_ACCT_LATE], 1);
11987 bbr->r_ctl.rc_last_delay_val = 0;
11988 tcp_hpts_remove(tp);
11989 } else if (tp->t_state == TCPS_CLOSED) {
11990 bbr->r_ctl.rc_last_delay_val = 0;
11991 tcp_hpts_remove(tp);
11992 } else {
11993 /*
11994 * On the hpts, you shall not pass! even if ACKNOW
11995 * is on, we will when the hpts fires, unless of
11996 * course we are overdue.
11997 */
11998 counter_u64_add(bbr_out_size[TCP_MSS_ACCT_INPACE], 1);
11999 return (0);
12000 }
12001 }
12002 bbr->rc_cwnd_limited = 0;
12003 if (bbr->r_ctl.rc_last_delay_val) {
12004 /* recalculate the real delay and deal with over/under */
12005 if (SEQ_GT(cts, bbr->rc_pacer_started))
12006 delay_calc = cts - bbr->rc_pacer_started;
12007 else
12008 delay_calc = 0;
12009 if (delay_calc >= bbr->r_ctl.rc_last_delay_val)
12010 /* Setup the delay which will be added in */
12011 delay_calc -= bbr->r_ctl.rc_last_delay_val;
12012 else {
12013 /*
12014 * We are early setup to adjust
12015 * our slot time.
12016 */
12017 uint64_t merged_val;
12018
12019 bbr->r_ctl.rc_agg_early += (bbr->r_ctl.rc_last_delay_val - delay_calc);
12020 bbr->r_agg_early_set = 1;
12021 if (bbr->r_ctl.rc_hptsi_agg_delay) {
12022 if (bbr->r_ctl.rc_hptsi_agg_delay >= bbr->r_ctl.rc_agg_early) {
12023 /* Nope our previous late cancels out the early */
12024 bbr->r_ctl.rc_hptsi_agg_delay -= bbr->r_ctl.rc_agg_early;
12025 bbr->r_agg_early_set = 0;
12026 bbr->r_ctl.rc_agg_early = 0;
12027 } else {
12028 bbr->r_ctl.rc_agg_early -= bbr->r_ctl.rc_hptsi_agg_delay;
12029 bbr->r_ctl.rc_hptsi_agg_delay = 0;
12030 }
12031 }
12032 merged_val = bbr->rc_pacer_started;
12033 merged_val <<= 32;
12034 merged_val |= bbr->r_ctl.rc_last_delay_val;
12035 bbr_log_pacing_delay_calc(bbr, hpts_calling,
12036 bbr->r_ctl.rc_agg_early, cts, delay_calc, merged_val,
12037 bbr->r_agg_early_set, 3);
12038 bbr->r_ctl.rc_last_delay_val = 0;
12039 BBR_STAT_INC(bbr_early);
12040 delay_calc = 0;
12041 }
12042 } else {
12043 /* We were not delayed due to hptsi */
12044 if (bbr->r_agg_early_set)
12045 bbr->r_ctl.rc_agg_early = 0;
12046 bbr->r_agg_early_set = 0;
12047 delay_calc = 0;
12048 }
12049 if (delay_calc) {
12050 /*
12051 * We had a hptsi delay which means we are falling behind on
12052 * sending at the expected rate. Calculate an extra amount
12053 * of data we can send, if any, to put us back on track.
12054 */
12055 if ((bbr->r_ctl.rc_hptsi_agg_delay + delay_calc) < bbr->r_ctl.rc_hptsi_agg_delay)
12056 bbr->r_ctl.rc_hptsi_agg_delay = 0xffffffff;
12057 else
12058 bbr->r_ctl.rc_hptsi_agg_delay += delay_calc;
12059 }
12060 sendwin = min(tp->snd_wnd, tp->snd_cwnd);
12061 if ((tp->snd_una == tp->snd_max) &&
12062 (bbr->rc_bbr_state != BBR_STATE_IDLE_EXIT) &&
12063 (sbavail(sb))) {
12064 /*
12065 * Ok we have been idle with nothing outstanding
12066 * we possibly need to start fresh with either a new
12067 * suite of states or a fast-ramp up.
12068 */
12069 bbr_restart_after_idle(bbr,
12070 cts, bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time));
12071 }
12072 /*
12073 * Now was there a hptsi delay where we are behind? We only count
12074 * being behind if: a) We are not in recovery. b) There was a delay.
12075 * <and> c) We had room to send something.
12076 *
12077 */
12078 if (bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
12079 int retval;
12080
12081 retval = bbr_process_timers(tp, bbr, cts, hpts_calling);
12082 if (retval != 0) {
12083 counter_u64_add(bbr_out_size[TCP_MSS_ACCT_ATIMER], 1);
12084 /*
12085 * If timers want tcp_drop(), then pass error out,
12086 * otherwise suppress it.
12087 */
12088 return (retval < 0 ? retval : 0);
12089 }
12090 }
12091 bbr->rc_tp->t_flags2 &= ~TF2_MBUF_QUEUE_READY;
12092 if (hpts_calling &&
12093 (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT)) {
12094 bbr->r_ctl.rc_last_delay_val = 0;
12095 }
12096 bbr->r_timer_override = 0;
12097 bbr->r_wanted_output = 0;
12098 /*
12099 * For TFO connections in SYN_RECEIVED, only allow the initial
12100 * SYN|ACK and those sent by the retransmit timer.
12101 */
12102 if ((tp->t_flags & TF_FASTOPEN) &&
12103 ((tp->t_state == TCPS_SYN_RECEIVED) ||
12104 (tp->t_state == TCPS_SYN_SENT)) &&
12105 SEQ_GT(tp->snd_max, tp->snd_una) && /* initial SYN or SYN|ACK sent */
12106 (tp->t_rxtshift == 0)) { /* not a retransmit */
12107 len = 0;
12108 goto just_return_nolock;
12109 }
12110 /*
12111 * Before sending anything check for a state update. For hpts
12112 * calling without input this is important. If its input calling
12113 * then this was already done.
12114 */
12115 if (bbr->rc_use_google == 0)
12116 bbr_check_bbr_for_state(bbr, cts, __LINE__, 0);
12117 again:
12118 /*
12119 * If we've recently taken a timeout, snd_max will be greater than
12120 * snd_max. BBR in general does not pay much attention to snd_nxt
12121 * for historic reasons the persist timer still uses it. This means
12122 * we have to look at it. All retransmissions that are not persits
12123 * use the rsm that needs to be sent so snd_nxt is ignored. At the
12124 * end of this routine we pull snd_nxt always up to snd_max.
12125 */
12126 doing_tlp = 0;
12127 #ifdef BBR_INVARIANTS
12128 doing_retran_from = picked_up_retran = 0;
12129 #endif
12130 error = 0;
12131 tso = 0;
12132 slot = 0;
12133 mtu = 0;
12134 sendwin = min(tp->snd_wnd, tp->snd_cwnd);
12135 sb_offset = tp->snd_max - tp->snd_una;
12136 flags = tcp_outflags[tp->t_state];
12137 sack_rxmit = 0;
12138 len = 0;
12139 rsm = NULL;
12140 if (flags & TH_RST) {
12141 SOCK_SENDBUF_LOCK(so);
12142 goto send;
12143 }
12144 recheck_resend:
12145 while (bbr->r_ctl.rc_free_cnt < bbr_min_req_free) {
12146 /* We need to always have one in reserve */
12147 rsm = bbr_alloc(bbr);
12148 if (rsm == NULL) {
12149 error = ENOMEM;
12150 /* Lie to get on the hpts */
12151 tot_len = tp->t_maxseg;
12152 if (hpts_calling)
12153 /* Retry in a ms */
12154 slot = 1001;
12155 goto just_return_nolock;
12156 }
12157 TAILQ_INSERT_TAIL(&bbr->r_ctl.rc_free, rsm, r_next);
12158 bbr->r_ctl.rc_free_cnt++;
12159 rsm = NULL;
12160 }
12161 /* What do we send, a resend? */
12162 if (bbr->r_ctl.rc_resend == NULL) {
12163 /* Check for rack timeout */
12164 bbr->r_ctl.rc_resend = bbr_check_recovery_mode(tp, bbr, cts);
12165 if (bbr->r_ctl.rc_resend) {
12166 #ifdef BBR_INVARIANTS
12167 picked_up_retran = 1;
12168 #endif
12169 bbr_cong_signal(tp, NULL, CC_NDUPACK, bbr->r_ctl.rc_resend);
12170 }
12171 }
12172 if (bbr->r_ctl.rc_resend) {
12173 rsm = bbr->r_ctl.rc_resend;
12174 #ifdef BBR_INVARIANTS
12175 doing_retran_from = 1;
12176 #endif
12177 /* Remove any TLP flags its a RACK or T-O */
12178 rsm->r_flags &= ~BBR_TLP;
12179 bbr->r_ctl.rc_resend = NULL;
12180 if (SEQ_LT(rsm->r_start, tp->snd_una)) {
12181 #ifdef BBR_INVARIANTS
12182 panic("Huh, tp:%p bbr:%p rsm:%p start:%u < snd_una:%u\n",
12183 tp, bbr, rsm, rsm->r_start, tp->snd_una);
12184 goto recheck_resend;
12185 #else
12186 /* TSNH */
12187 rsm = NULL;
12188 goto recheck_resend;
12189 #endif
12190 }
12191 if (rsm->r_flags & BBR_HAS_SYN) {
12192 /* Only retransmit a SYN by itself */
12193 len = 0;
12194 if ((flags & TH_SYN) == 0) {
12195 /* Huh something is wrong */
12196 rsm->r_start++;
12197 if (rsm->r_start == rsm->r_end) {
12198 /* Clean it up, somehow we missed the ack? */
12199 bbr_log_syn(tp, NULL);
12200 } else {
12201 /* TFO with data? */
12202 rsm->r_flags &= ~BBR_HAS_SYN;
12203 len = rsm->r_end - rsm->r_start;
12204 }
12205 } else {
12206 /* Retransmitting SYN */
12207 rsm = NULL;
12208 SOCK_SENDBUF_LOCK(so);
12209 goto send;
12210 }
12211 } else
12212 len = rsm->r_end - rsm->r_start;
12213 if ((bbr->rc_resends_use_tso == 0) &&
12214 (len > maxseg)) {
12215 len = maxseg;
12216 more_to_rxt = 1;
12217 }
12218 sb_offset = rsm->r_start - tp->snd_una;
12219 if (len > 0) {
12220 sack_rxmit = 1;
12221 KMOD_TCPSTAT_INC(tcps_sack_rexmits);
12222 KMOD_TCPSTAT_ADD(tcps_sack_rexmit_bytes,
12223 min(len, maxseg));
12224 } else {
12225 /* I dont think this can happen */
12226 rsm = NULL;
12227 goto recheck_resend;
12228 }
12229 BBR_STAT_INC(bbr_resends_set);
12230 } else if (bbr->r_ctl.rc_tlp_send) {
12231 /*
12232 * Tail loss probe
12233 */
12234 doing_tlp = 1;
12235 rsm = bbr->r_ctl.rc_tlp_send;
12236 bbr->r_ctl.rc_tlp_send = NULL;
12237 sack_rxmit = 1;
12238 len = rsm->r_end - rsm->r_start;
12239 if ((bbr->rc_resends_use_tso == 0) && (len > maxseg))
12240 len = maxseg;
12241
12242 if (SEQ_GT(tp->snd_una, rsm->r_start)) {
12243 #ifdef BBR_INVARIANTS
12244 panic("tp:%p bbc:%p snd_una:%u rsm:%p r_start:%u",
12245 tp, bbr, tp->snd_una, rsm, rsm->r_start);
12246 #else
12247 /* TSNH */
12248 rsm = NULL;
12249 goto recheck_resend;
12250 #endif
12251 }
12252 sb_offset = rsm->r_start - tp->snd_una;
12253 BBR_STAT_INC(bbr_tlp_set);
12254 }
12255 /*
12256 * Enforce a connection sendmap count limit if set
12257 * as long as we are not retransmiting.
12258 */
12259 if ((rsm == NULL) &&
12260 (V_tcp_map_entries_limit > 0) &&
12261 (bbr->r_ctl.rc_num_maps_alloced >= V_tcp_map_entries_limit)) {
12262 BBR_STAT_INC(bbr_alloc_limited);
12263 if (!bbr->alloc_limit_reported) {
12264 bbr->alloc_limit_reported = 1;
12265 BBR_STAT_INC(bbr_alloc_limited_conns);
12266 }
12267 goto just_return_nolock;
12268 }
12269 #ifdef BBR_INVARIANTS
12270 if (rsm && SEQ_LT(rsm->r_start, tp->snd_una)) {
12271 panic("tp:%p bbr:%p rsm:%p sb_offset:%u len:%u",
12272 tp, bbr, rsm, sb_offset, len);
12273 }
12274 #endif
12275 /*
12276 * Get standard flags, and add SYN or FIN if requested by 'hidden'
12277 * state flags.
12278 */
12279 if (tp->t_flags & TF_NEEDFIN && (rsm == NULL))
12280 flags |= TH_FIN;
12281 if (tp->t_flags & TF_NEEDSYN)
12282 flags |= TH_SYN;
12283
12284 if (rsm && (rsm->r_flags & BBR_HAS_FIN)) {
12285 /* we are retransmitting the fin */
12286 len--;
12287 if (len) {
12288 /*
12289 * When retransmitting data do *not* include the
12290 * FIN. This could happen from a TLP probe if we
12291 * allowed data with a FIN.
12292 */
12293 flags &= ~TH_FIN;
12294 }
12295 } else if (rsm) {
12296 if (flags & TH_FIN)
12297 flags &= ~TH_FIN;
12298 }
12299 if ((sack_rxmit == 0) && (prefetch_rsm == 0)) {
12300 void *end_rsm;
12301
12302 end_rsm = TAILQ_LAST_FAST(&bbr->r_ctl.rc_tmap, bbr_sendmap, r_tnext);
12303 if (end_rsm)
12304 kern_prefetch(end_rsm, &prefetch_rsm);
12305 prefetch_rsm = 1;
12306 }
12307 SOCK_SENDBUF_LOCK(so);
12308 /*
12309 * If snd_nxt == snd_max and we have transmitted a FIN, the
12310 * sb_offset will be > 0 even if so_snd.sb_cc is 0, resulting in a
12311 * negative length. This can also occur when TCP opens up its
12312 * congestion window while receiving additional duplicate acks after
12313 * fast-retransmit because TCP will reset snd_nxt to snd_max after
12314 * the fast-retransmit.
12315 *
12316 * In the normal retransmit-FIN-only case, however, snd_nxt will be
12317 * set to snd_una, the sb_offset will be 0, and the length may wind
12318 * up 0.
12319 *
12320 * If sack_rxmit is true we are retransmitting from the scoreboard
12321 * in which case len is already set.
12322 */
12323 if (sack_rxmit == 0) {
12324 uint32_t avail;
12325
12326 avail = sbavail(sb);
12327 if (SEQ_GT(tp->snd_max, tp->snd_una))
12328 sb_offset = tp->snd_max - tp->snd_una;
12329 else
12330 sb_offset = 0;
12331 if (bbr->rc_tlp_new_data) {
12332 /* TLP is forcing out new data */
12333 uint32_t tlplen;
12334
12335 doing_tlp = 1;
12336 tlplen = maxseg;
12337
12338 if (tlplen > (uint32_t)(avail - sb_offset)) {
12339 tlplen = (uint32_t)(avail - sb_offset);
12340 }
12341 if (tlplen > tp->snd_wnd) {
12342 len = tp->snd_wnd;
12343 } else {
12344 len = tlplen;
12345 }
12346 bbr->rc_tlp_new_data = 0;
12347 } else {
12348 len = bbr_what_can_we_send(tp, bbr, sendwin, avail, sb_offset, cts);
12349 if ((len < p_maxseg) &&
12350 (bbr->rc_in_persist == 0) &&
12351 (ctf_outstanding(tp) >= (2 * p_maxseg)) &&
12352 ((avail - sb_offset) >= p_maxseg)) {
12353 /*
12354 * We are not completing whats in the socket
12355 * buffer (i.e. there is at least a segment
12356 * waiting to send) and we have 2 or more
12357 * segments outstanding. There is no sense
12358 * of sending a little piece. Lets defer and
12359 * and wait until we can send a whole
12360 * segment.
12361 */
12362 len = 0;
12363 }
12364 if (bbr->rc_in_persist) {
12365 /*
12366 * We are in persists, figure out if
12367 * a retransmit is available (maybe the previous
12368 * persists we sent) or if we have to send new
12369 * data.
12370 */
12371 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
12372 if (rsm) {
12373 len = rsm->r_end - rsm->r_start;
12374 if (rsm->r_flags & BBR_HAS_FIN)
12375 len--;
12376 if ((bbr->rc_resends_use_tso == 0) && (len > maxseg))
12377 len = maxseg;
12378 if (len > 1)
12379 BBR_STAT_INC(bbr_persist_reneg);
12380 /*
12381 * XXXrrs we could force the len to
12382 * 1 byte here to cause the chunk to
12383 * split apart.. but that would then
12384 * mean we always retransmit it as
12385 * one byte even after the window
12386 * opens.
12387 */
12388 sack_rxmit = 1;
12389 sb_offset = rsm->r_start - tp->snd_una;
12390 } else {
12391 /*
12392 * First time through in persists or peer
12393 * acked our one byte. Though we do have
12394 * to have something in the sb.
12395 */
12396 len = 1;
12397 sb_offset = 0;
12398 if (avail == 0)
12399 len = 0;
12400 }
12401 }
12402 }
12403 }
12404 if (prefetch_so_done == 0) {
12405 kern_prefetch(so, &prefetch_so_done);
12406 prefetch_so_done = 1;
12407 }
12408 /*
12409 * Lop off SYN bit if it has already been sent. However, if this is
12410 * SYN-SENT state and if segment contains data and if we don't know
12411 * that foreign host supports TAO, suppress sending segment.
12412 */
12413 if ((flags & TH_SYN) && (rsm == NULL) &&
12414 SEQ_GT(tp->snd_max, tp->snd_una)) {
12415 if (tp->t_state != TCPS_SYN_RECEIVED)
12416 flags &= ~TH_SYN;
12417 /*
12418 * When sending additional segments following a TFO SYN|ACK,
12419 * do not include the SYN bit.
12420 */
12421 if ((tp->t_flags & TF_FASTOPEN) &&
12422 (tp->t_state == TCPS_SYN_RECEIVED))
12423 flags &= ~TH_SYN;
12424 sb_offset--, len++;
12425 if (sbavail(sb) == 0)
12426 len = 0;
12427 } else if ((flags & TH_SYN) && rsm) {
12428 /*
12429 * Subtract one from the len for the SYN being
12430 * retransmitted.
12431 */
12432 len--;
12433 }
12434 /*
12435 * Be careful not to send data and/or FIN on SYN segments. This
12436 * measure is needed to prevent interoperability problems with not
12437 * fully conformant TCP implementations.
12438 */
12439 if ((flags & TH_SYN) && (tp->t_flags & TF_NOOPT)) {
12440 len = 0;
12441 flags &= ~TH_FIN;
12442 }
12443 /*
12444 * On TFO sockets, ensure no data is sent in the following cases:
12445 *
12446 * - When retransmitting SYN|ACK on a passively-created socket
12447 * - When retransmitting SYN on an actively created socket
12448 * - When sending a zero-length cookie (cookie request) on an
12449 * actively created socket
12450 * - When the socket is in the CLOSED state (RST is being sent)
12451 */
12452 if ((tp->t_flags & TF_FASTOPEN) &&
12453 (((flags & TH_SYN) && (tp->t_rxtshift > 0)) ||
12454 ((tp->t_state == TCPS_SYN_SENT) &&
12455 (tp->t_tfo_client_cookie_len == 0)) ||
12456 (flags & TH_RST))) {
12457 len = 0;
12458 sack_rxmit = 0;
12459 rsm = NULL;
12460 }
12461 /* Without fast-open there should never be data sent on a SYN */
12462 if ((flags & TH_SYN) && !(tp->t_flags & TF_FASTOPEN))
12463 len = 0;
12464 if (len <= 0) {
12465 /*
12466 * If FIN has been sent but not acked, but we haven't been
12467 * called to retransmit, len will be < 0. Otherwise, window
12468 * shrank after we sent into it. If window shrank to 0,
12469 * cancel pending retransmit, pull snd_nxt back to (closed)
12470 * window, and set the persist timer if it isn't already
12471 * going. If the window didn't close completely, just wait
12472 * for an ACK.
12473 *
12474 * We also do a general check here to ensure that we will
12475 * set the persist timer when we have data to send, but a
12476 * 0-byte window. This makes sure the persist timer is set
12477 * even if the packet hits one of the "goto send" lines
12478 * below.
12479 */
12480 len = 0;
12481 if ((tp->snd_wnd == 0) &&
12482 (TCPS_HAVEESTABLISHED(tp->t_state)) &&
12483 (tp->snd_una == tp->snd_max) &&
12484 (sb_offset < (int)sbavail(sb))) {
12485 /*
12486 * Not enough room in the rwnd to send
12487 * a paced segment out.
12488 */
12489 bbr_enter_persist(tp, bbr, cts, __LINE__);
12490 }
12491 } else if ((rsm == NULL) &&
12492 (doing_tlp == 0) &&
12493 (len < bbr->r_ctl.rc_pace_max_segs)) {
12494 /*
12495 * We are not sending a full segment for
12496 * some reason. Should we not send anything (think
12497 * sws or persists)?
12498 */
12499 if ((tp->snd_wnd < min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) &&
12500 (TCPS_HAVEESTABLISHED(tp->t_state)) &&
12501 (len < (int)(sbavail(sb) - sb_offset))) {
12502 /*
12503 * Here the rwnd is less than
12504 * the pacing size, this is not a retransmit,
12505 * we are established and
12506 * the send is not the last in the socket buffer
12507 * lets not send, and possibly enter persists.
12508 */
12509 len = 0;
12510 if (tp->snd_max == tp->snd_una)
12511 bbr_enter_persist(tp, bbr, cts, __LINE__);
12512 } else if ((tp->snd_cwnd >= bbr->r_ctl.rc_pace_max_segs) &&
12513 (ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
12514 bbr->r_ctl.rc_lost_bytes)) > (2 * maxseg)) &&
12515 (len < (int)(sbavail(sb) - sb_offset)) &&
12516 (len < bbr_minseg(bbr))) {
12517 /*
12518 * Here we are not retransmitting, and
12519 * the cwnd is not so small that we could
12520 * not send at least a min size (rxt timer
12521 * not having gone off), We have 2 segments or
12522 * more already in flight, its not the tail end
12523 * of the socket buffer and the cwnd is blocking
12524 * us from sending out minimum pacing segment size.
12525 * Lets not send anything.
12526 */
12527 bbr->rc_cwnd_limited = 1;
12528 len = 0;
12529 } else if (((tp->snd_wnd - ctf_outstanding(tp)) <
12530 min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) &&
12531 (ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
12532 bbr->r_ctl.rc_lost_bytes)) > (2 * maxseg)) &&
12533 (len < (int)(sbavail(sb) - sb_offset)) &&
12534 (TCPS_HAVEESTABLISHED(tp->t_state))) {
12535 /*
12536 * Here we have a send window but we have
12537 * filled it up and we can't send another pacing segment.
12538 * We also have in flight more than 2 segments
12539 * and we are not completing the sb i.e. we allow
12540 * the last bytes of the sb to go out even if
12541 * its not a full pacing segment.
12542 */
12543 len = 0;
12544 }
12545 }
12546 /* len will be >= 0 after this point. */
12547 KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
12548 tcp_sndbuf_autoscale(tp, so, sendwin);
12549 /*
12550 *
12551 */
12552 if (bbr->rc_in_persist &&
12553 len &&
12554 (rsm == NULL) &&
12555 (len < min((bbr->r_ctl.rc_high_rwnd/2), bbr->r_ctl.rc_pace_max_segs))) {
12556 /*
12557 * We are in persist, not doing a retransmit and don't have enough space
12558 * yet to send a full TSO. So is it at the end of the sb
12559 * if so we need to send else nuke to 0 and don't send.
12560 */
12561 int sbleft;
12562 if (sbavail(sb) > sb_offset)
12563 sbleft = sbavail(sb) - sb_offset;
12564 else
12565 sbleft = 0;
12566 if (sbleft >= min((bbr->r_ctl.rc_high_rwnd/2), bbr->r_ctl.rc_pace_max_segs)) {
12567 /* not at end of sb lets not send */
12568 len = 0;
12569 }
12570 }
12571 /*
12572 * Decide if we can use TCP Segmentation Offloading (if supported by
12573 * hardware).
12574 *
12575 * TSO may only be used if we are in a pure bulk sending state. The
12576 * presence of TCP-MD5, SACK retransmits, SACK advertizements and IP
12577 * options prevent using TSO. With TSO the TCP header is the same
12578 * (except for the sequence number) for all generated packets. This
12579 * makes it impossible to transmit any options which vary per
12580 * generated segment or packet.
12581 *
12582 * IPv4 handling has a clear separation of ip options and ip header
12583 * flags while IPv6 combines both in in6p_outputopts. ip6_optlen()
12584 * does the right thing below to provide length of just ip options
12585 * and thus checking for ipoptlen is enough to decide if ip options
12586 * are present.
12587 */
12588 #ifdef INET6
12589 if (isipv6)
12590 ipoptlen = ip6_optlen(inp);
12591 else
12592 #endif
12593 if (inp->inp_options)
12594 ipoptlen = inp->inp_options->m_len -
12595 offsetof(struct ipoption, ipopt_list);
12596 else
12597 ipoptlen = 0;
12598 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
12599 /*
12600 * Pre-calculate here as we save another lookup into the darknesses
12601 * of IPsec that way and can actually decide if TSO is ok.
12602 */
12603 #ifdef INET6
12604 if (isipv6 && IPSEC_ENABLED(ipv6))
12605 ipsec_optlen = IPSEC_HDRSIZE(ipv6, inp);
12606 #ifdef INET
12607 else
12608 #endif
12609 #endif /* INET6 */
12610 #ifdef INET
12611 if (IPSEC_ENABLED(ipv4))
12612 ipsec_optlen = IPSEC_HDRSIZE(ipv4, inp);
12613 #endif /* INET */
12614 #endif /* IPSEC */
12615 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
12616 ipoptlen += ipsec_optlen;
12617 #endif
12618 if ((tp->t_flags & TF_TSO) && V_tcp_do_tso &&
12619 (len > maxseg) &&
12620 (tp->t_port == 0) &&
12621 ((tp->t_flags & TF_SIGNATURE) == 0) &&
12622 ipoptlen == 0)
12623 tso = 1;
12624
12625 recwin = lmin(lmax(sbspace(&so->so_rcv), 0),
12626 (long)TCP_MAXWIN << tp->rcv_scale);
12627 /*
12628 * Sender silly window avoidance. We transmit under the following
12629 * conditions when len is non-zero:
12630 *
12631 * - We have a full segment (or more with TSO) - This is the last
12632 * buffer in a write()/send() and we are either idle or running
12633 * NODELAY - we've timed out (e.g. persist timer) - we have more
12634 * then 1/2 the maximum send window's worth of data (receiver may be
12635 * limited the window size) - we need to retransmit
12636 */
12637 if (rsm)
12638 goto send;
12639 if (len) {
12640 if (sack_rxmit)
12641 goto send;
12642 if (len >= p_maxseg)
12643 goto send;
12644 /*
12645 * NOTE! on localhost connections an 'ack' from the remote
12646 * end may occur synchronously with the output and cause us
12647 * to flush a buffer queued with moretocome. XXX
12648 *
12649 */
12650 if (((tp->t_flags & TF_MORETOCOME) == 0) && /* normal case */
12651 ((tp->t_flags & TF_NODELAY) ||
12652 ((uint32_t)len + (uint32_t)sb_offset) >= sbavail(&so->so_snd)) &&
12653 (tp->t_flags & TF_NOPUSH) == 0) {
12654 goto send;
12655 }
12656 if ((tp->snd_una == tp->snd_max) && len) { /* Nothing outstanding */
12657 goto send;
12658 }
12659 if (len >= tp->max_sndwnd / 2 && tp->max_sndwnd > 0) {
12660 goto send;
12661 }
12662 }
12663 /*
12664 * Sending of standalone window updates.
12665 *
12666 * Window updates are important when we close our window due to a
12667 * full socket buffer and are opening it again after the application
12668 * reads data from it. Once the window has opened again and the
12669 * remote end starts to send again the ACK clock takes over and
12670 * provides the most current window information.
12671 *
12672 * We must avoid the silly window syndrome whereas every read from
12673 * the receive buffer, no matter how small, causes a window update
12674 * to be sent. We also should avoid sending a flurry of window
12675 * updates when the socket buffer had queued a lot of data and the
12676 * application is doing small reads.
12677 *
12678 * Prevent a flurry of pointless window updates by only sending an
12679 * update when we can increase the advertized window by more than
12680 * 1/4th of the socket buffer capacity. When the buffer is getting
12681 * full or is very small be more aggressive and send an update
12682 * whenever we can increase by two mss sized segments. In all other
12683 * situations the ACK's to new incoming data will carry further
12684 * window increases.
12685 *
12686 * Don't send an independent window update if a delayed ACK is
12687 * pending (it will get piggy-backed on it) or the remote side
12688 * already has done a half-close and won't send more data. Skip
12689 * this if the connection is in T/TCP half-open state.
12690 */
12691 if (recwin > 0 && !(tp->t_flags & TF_NEEDSYN) &&
12692 !(tp->t_flags & TF_DELACK) &&
12693 !TCPS_HAVERCVDFIN(tp->t_state)) {
12694 /* Check to see if we should do a window update */
12695 if (bbr_window_update_needed(tp, so, recwin, maxseg))
12696 goto send;
12697 }
12698 /*
12699 * Send if we owe the peer an ACK, RST, SYN. ACKNOW
12700 * is also a catch-all for the retransmit timer timeout case.
12701 */
12702 if (tp->t_flags & TF_ACKNOW) {
12703 goto send;
12704 }
12705 if (flags & TH_RST) {
12706 /* Always send a RST if one is due */
12707 goto send;
12708 }
12709 if ((flags & TH_SYN) && (tp->t_flags & TF_NEEDSYN) == 0) {
12710 goto send;
12711 }
12712 /*
12713 * If our state indicates that FIN should be sent and we have not
12714 * yet done so, then we need to send.
12715 */
12716 if (flags & TH_FIN &&
12717 ((tp->t_flags & TF_SENTFIN) == 0)) {
12718 goto send;
12719 }
12720 /*
12721 * No reason to send a segment, just return.
12722 */
12723 just_return:
12724 SOCK_SENDBUF_UNLOCK(so);
12725 just_return_nolock:
12726 if (tot_len)
12727 slot = bbr_get_pacing_delay(bbr, bbr->r_ctl.rc_bbr_hptsi_gain, tot_len, cts, 0);
12728 if (bbr->rc_no_pacing)
12729 slot = 0;
12730 if (tot_len == 0) {
12731 if ((ctf_outstanding(tp) + min((bbr->r_ctl.rc_high_rwnd/2), bbr_minseg(bbr))) >=
12732 tp->snd_wnd) {
12733 BBR_STAT_INC(bbr_rwnd_limited);
12734 app_limited = BBR_JR_RWND_LIMITED;
12735 bbr_cwnd_limiting(tp, bbr, ctf_outstanding(tp));
12736 if ((bbr->rc_in_persist == 0) &&
12737 TCPS_HAVEESTABLISHED(tp->t_state) &&
12738 (tp->snd_max == tp->snd_una) &&
12739 sbavail(&so->so_snd)) {
12740 /* No send window.. we must enter persist */
12741 bbr_enter_persist(tp, bbr, bbr->r_ctl.rc_rcvtime, __LINE__);
12742 }
12743 } else if (ctf_outstanding(tp) >= sbavail(sb)) {
12744 BBR_STAT_INC(bbr_app_limited);
12745 app_limited = BBR_JR_APP_LIMITED;
12746 bbr_cwnd_limiting(tp, bbr, ctf_outstanding(tp));
12747 } else if ((ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
12748 bbr->r_ctl.rc_lost_bytes)) + p_maxseg) >= tp->snd_cwnd) {
12749 BBR_STAT_INC(bbr_cwnd_limited);
12750 app_limited = BBR_JR_CWND_LIMITED;
12751 bbr_cwnd_limiting(tp, bbr, ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
12752 bbr->r_ctl.rc_lost_bytes)));
12753 bbr->rc_cwnd_limited = 1;
12754 } else {
12755 BBR_STAT_INC(bbr_app_limited);
12756 app_limited = BBR_JR_APP_LIMITED;
12757 bbr_cwnd_limiting(tp, bbr, ctf_outstanding(tp));
12758 }
12759 bbr->r_ctl.rc_hptsi_agg_delay = 0;
12760 bbr->r_agg_early_set = 0;
12761 bbr->r_ctl.rc_agg_early = 0;
12762 bbr->r_ctl.rc_last_delay_val = 0;
12763 } else if (bbr->rc_use_google == 0)
12764 bbr_check_bbr_for_state(bbr, cts, __LINE__, 0);
12765 /* Are we app limited? */
12766 if ((app_limited == BBR_JR_APP_LIMITED) ||
12767 (app_limited == BBR_JR_RWND_LIMITED)) {
12768 /**
12769 * We are application limited.
12770 */
12771 bbr->r_ctl.r_app_limited_until = (ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
12772 bbr->r_ctl.rc_lost_bytes)) + bbr->r_ctl.rc_delivered);
12773 }
12774 if (tot_len == 0)
12775 counter_u64_add(bbr_out_size[TCP_MSS_ACCT_JUSTRET], 1);
12776 /* Dont update the time if we did not send */
12777 bbr->r_ctl.rc_last_delay_val = 0;
12778 bbr->rc_output_starts_timer = 1;
12779 bbr_start_hpts_timer(bbr, tp, cts, 9, slot, tot_len);
12780 bbr_log_type_just_return(bbr, cts, tot_len, hpts_calling, app_limited, p_maxseg, len);
12781 if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
12782 /* Make sure snd_nxt is drug up */
12783 tp->snd_nxt = tp->snd_max;
12784 }
12785 return (error);
12786
12787 send:
12788 if (doing_tlp == 0) {
12789 /*
12790 * Data not a TLP, and its not the rxt firing. If it is the
12791 * rxt firing, we want to leave the tlp_in_progress flag on
12792 * so we don't send another TLP. It has to be a rack timer
12793 * or normal send (response to acked data) to clear the tlp
12794 * in progress flag.
12795 */
12796 bbr->rc_tlp_in_progress = 0;
12797 bbr->rc_tlp_rtx_out = 0;
12798 } else {
12799 /*
12800 * Its a TLP.
12801 */
12802 bbr->rc_tlp_in_progress = 1;
12803 }
12804 bbr_timer_cancel(bbr, __LINE__, cts);
12805 if (rsm == NULL) {
12806 if (sbused(sb) > 0) {
12807 /*
12808 * This is sub-optimal. We only send a stand alone
12809 * FIN on its own segment.
12810 */
12811 if (flags & TH_FIN) {
12812 flags &= ~TH_FIN;
12813 if ((len == 0) && ((tp->t_flags & TF_ACKNOW) == 0)) {
12814 /* Lets not send this */
12815 slot = 0;
12816 goto just_return;
12817 }
12818 }
12819 }
12820 } else {
12821 /*
12822 * We do *not* send a FIN on a retransmit if it has data.
12823 * The if clause here where len > 1 should never come true.
12824 */
12825 if ((len > 0) &&
12826 (((rsm->r_flags & BBR_HAS_FIN) == 0) &&
12827 (flags & TH_FIN))) {
12828 flags &= ~TH_FIN;
12829 len--;
12830 }
12831 }
12832 SOCK_SENDBUF_LOCK_ASSERT(so);
12833 if (len > 0) {
12834 if ((tp->snd_una == tp->snd_max) &&
12835 (bbr_calc_time(cts, bbr->r_ctl.rc_went_idle_time) >= bbr_rtt_probe_time)) {
12836 /*
12837 * This qualifies as a RTT_PROBE session since we
12838 * drop the data outstanding to nothing and waited
12839 * more than bbr_rtt_probe_time.
12840 */
12841 bbr_log_rtt_shrinks(bbr, cts, 0, 0, __LINE__, BBR_RTTS_WASIDLE, 0);
12842 bbr_set_reduced_rtt(bbr, cts, __LINE__);
12843 }
12844 if (len >= maxseg)
12845 tp->t_flags2 |= TF2_PLPMTU_MAXSEGSNT;
12846 else
12847 tp->t_flags2 &= ~TF2_PLPMTU_MAXSEGSNT;
12848 }
12849 /*
12850 * Before ESTABLISHED, force sending of initial options unless TCP
12851 * set not to do any options. NOTE: we assume that the IP/TCP header
12852 * plus TCP options always fit in a single mbuf, leaving room for a
12853 * maximum link header, i.e. max_linkhdr + sizeof (struct tcpiphdr)
12854 * + optlen <= MCLBYTES
12855 */
12856 optlen = 0;
12857 #ifdef INET6
12858 if (isipv6)
12859 hdrlen = sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
12860 else
12861 #endif
12862 hdrlen = sizeof(struct tcpiphdr);
12863
12864 /*
12865 * Compute options for segment. We only have to care about SYN and
12866 * established connection segments. Options for SYN-ACK segments
12867 * are handled in TCP syncache.
12868 */
12869 to.to_flags = 0;
12870 local_options = 0;
12871 if ((tp->t_flags & TF_NOOPT) == 0) {
12872 /* Maximum segment size. */
12873 if (flags & TH_SYN) {
12874 to.to_mss = tcp_mssopt(&inp->inp_inc);
12875 if (tp->t_port)
12876 to.to_mss -= V_tcp_udp_tunneling_overhead;
12877 to.to_flags |= TOF_MSS;
12878 /*
12879 * On SYN or SYN|ACK transmits on TFO connections,
12880 * only include the TFO option if it is not a
12881 * retransmit, as the presence of the TFO option may
12882 * have caused the original SYN or SYN|ACK to have
12883 * been dropped by a middlebox.
12884 */
12885 if ((tp->t_flags & TF_FASTOPEN) &&
12886 (tp->t_rxtshift == 0)) {
12887 if (tp->t_state == TCPS_SYN_RECEIVED) {
12888 to.to_tfo_len = TCP_FASTOPEN_COOKIE_LEN;
12889 to.to_tfo_cookie =
12890 (u_int8_t *)&tp->t_tfo_cookie.server;
12891 to.to_flags |= TOF_FASTOPEN;
12892 wanted_cookie = 1;
12893 } else if (tp->t_state == TCPS_SYN_SENT) {
12894 to.to_tfo_len =
12895 tp->t_tfo_client_cookie_len;
12896 to.to_tfo_cookie =
12897 tp->t_tfo_cookie.client;
12898 to.to_flags |= TOF_FASTOPEN;
12899 wanted_cookie = 1;
12900 }
12901 }
12902 }
12903 /* Window scaling. */
12904 if ((flags & TH_SYN) && (tp->t_flags & TF_REQ_SCALE)) {
12905 to.to_wscale = tp->request_r_scale;
12906 to.to_flags |= TOF_SCALE;
12907 }
12908 /* Timestamps. */
12909 if ((tp->t_flags & TF_RCVD_TSTMP) ||
12910 ((flags & TH_SYN) && (tp->t_flags & TF_REQ_TSTMP))) {
12911 to.to_tsval = tcp_tv_to_mssectick(&bbr->rc_tv) + tp->ts_offset;
12912 to.to_tsecr = tp->ts_recent;
12913 to.to_flags |= TOF_TS;
12914 local_options += TCPOLEN_TIMESTAMP + 2;
12915 }
12916 /* Set receive buffer autosizing timestamp. */
12917 if (tp->rfbuf_ts == 0 &&
12918 (so->so_rcv.sb_flags & SB_AUTOSIZE))
12919 tp->rfbuf_ts = tcp_tv_to_mssectick(&bbr->rc_tv);
12920 /* Selective ACK's. */
12921 if (flags & TH_SYN)
12922 to.to_flags |= TOF_SACKPERM;
12923 else if (TCPS_HAVEESTABLISHED(tp->t_state) &&
12924 tp->rcv_numsacks > 0) {
12925 to.to_flags |= TOF_SACK;
12926 to.to_nsacks = tp->rcv_numsacks;
12927 to.to_sacks = (u_char *)tp->sackblks;
12928 }
12929 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
12930 /* TCP-MD5 (RFC2385). */
12931 if (tp->t_flags & TF_SIGNATURE)
12932 to.to_flags |= TOF_SIGNATURE;
12933 #endif /* TCP_SIGNATURE */
12934
12935 /* Processing the options. */
12936 hdrlen += (optlen = tcp_addoptions(&to, opt));
12937 /*
12938 * If we wanted a TFO option to be added, but it was unable
12939 * to fit, ensure no data is sent.
12940 */
12941 if ((tp->t_flags & TF_FASTOPEN) && wanted_cookie &&
12942 !(to.to_flags & TOF_FASTOPEN))
12943 len = 0;
12944 }
12945 if (tp->t_port) {
12946 if (V_tcp_udp_tunneling_port == 0) {
12947 /* The port was removed?? */
12948 SOCK_SENDBUF_UNLOCK(so);
12949 return (EHOSTUNREACH);
12950 }
12951 hdrlen += sizeof(struct udphdr);
12952 }
12953 #ifdef INET6
12954 if (isipv6)
12955 ipoptlen = ip6_optlen(inp);
12956 else
12957 #endif
12958 if (inp->inp_options)
12959 ipoptlen = inp->inp_options->m_len -
12960 offsetof(struct ipoption, ipopt_list);
12961 else
12962 ipoptlen = 0;
12963 ipoptlen = 0;
12964 #if defined(IPSEC) || defined(IPSEC_SUPPORT)
12965 ipoptlen += ipsec_optlen;
12966 #endif
12967 if (bbr->rc_last_options != local_options) {
12968 /*
12969 * Cache the options length this generally does not change
12970 * on a connection. We use this to calculate TSO.
12971 */
12972 bbr->rc_last_options = local_options;
12973 }
12974 maxseg = tp->t_maxseg - (ipoptlen + optlen);
12975 p_maxseg = min(maxseg, pace_max_segs);
12976 /*
12977 * Adjust data length if insertion of options will bump the packet
12978 * length beyond the t_maxseg length. Clear the FIN bit because we
12979 * cut off the tail of the segment.
12980 */
12981 if (len > maxseg) {
12982 if (len != 0 && (flags & TH_FIN)) {
12983 flags &= ~TH_FIN;
12984 }
12985 if (tso) {
12986 uint32_t moff;
12987 int32_t max_len;
12988
12989 /* extract TSO information */
12990 if_hw_tsomax = tp->t_tsomax;
12991 if_hw_tsomaxsegcount = tp->t_tsomaxsegcount;
12992 if_hw_tsomaxsegsize = tp->t_tsomaxsegsize;
12993 KASSERT(ipoptlen == 0,
12994 ("%s: TSO can't do IP options", __func__));
12995
12996 /*
12997 * Check if we should limit by maximum payload
12998 * length:
12999 */
13000 if (if_hw_tsomax != 0) {
13001 /* compute maximum TSO length */
13002 max_len = (if_hw_tsomax - hdrlen -
13003 max_linkhdr);
13004 if (max_len <= 0) {
13005 len = 0;
13006 } else if (len > max_len) {
13007 len = max_len;
13008 }
13009 }
13010 /*
13011 * Prevent the last segment from being fractional
13012 * unless the send sockbuf can be emptied:
13013 */
13014 if ((sb_offset + len) < sbavail(sb)) {
13015 moff = len % (uint32_t)maxseg;
13016 if (moff != 0) {
13017 len -= moff;
13018 }
13019 }
13020 /*
13021 * In case there are too many small fragments don't
13022 * use TSO:
13023 */
13024 if (len <= maxseg) {
13025 len = maxseg;
13026 tso = 0;
13027 }
13028 } else {
13029 /* Not doing TSO */
13030 if (optlen + ipoptlen >= tp->t_maxseg) {
13031 /*
13032 * Since we don't have enough space to put
13033 * the IP header chain and the TCP header in
13034 * one packet as required by RFC 7112, don't
13035 * send it. Also ensure that at least one
13036 * byte of the payload can be put into the
13037 * TCP segment.
13038 */
13039 SOCK_SENDBUF_UNLOCK(so);
13040 error = EMSGSIZE;
13041 sack_rxmit = 0;
13042 goto out;
13043 }
13044 len = maxseg;
13045 }
13046 } else {
13047 /* Not doing TSO */
13048 if_hw_tsomaxsegcount = 0;
13049 tso = 0;
13050 }
13051 KASSERT(len + hdrlen + ipoptlen <= IP_MAXPACKET,
13052 ("%s: len > IP_MAXPACKET", __func__));
13053 #ifdef DIAGNOSTIC
13054 #ifdef INET6
13055 if (max_linkhdr + hdrlen > MCLBYTES)
13056 #else
13057 if (max_linkhdr + hdrlen > MHLEN)
13058 #endif
13059 panic("tcphdr too big");
13060 #endif
13061 /*
13062 * This KASSERT is here to catch edge cases at a well defined place.
13063 * Before, those had triggered (random) panic conditions further
13064 * down.
13065 */
13066 #ifdef BBR_INVARIANTS
13067 if (sack_rxmit) {
13068 if (SEQ_LT(rsm->r_start, tp->snd_una)) {
13069 panic("RSM:%p TP:%p bbr:%p start:%u is < snd_una:%u",
13070 rsm, tp, bbr, rsm->r_start, tp->snd_una);
13071 }
13072 }
13073 #endif
13074 KASSERT(len >= 0, ("[%s:%d]: len < 0", __func__, __LINE__));
13075 if ((len == 0) &&
13076 (flags & TH_FIN) &&
13077 (sbused(sb))) {
13078 /*
13079 * We have outstanding data, don't send a fin by itself!.
13080 */
13081 slot = 0;
13082 goto just_return;
13083 }
13084 /*
13085 * Grab a header mbuf, attaching a copy of data to be transmitted,
13086 * and initialize the header from the template for sends on this
13087 * connection.
13088 */
13089 if (len) {
13090 uint32_t moff;
13091
13092 /*
13093 * We place a limit on sending with hptsi.
13094 */
13095 if ((rsm == NULL) && len > pace_max_segs)
13096 len = pace_max_segs;
13097 if (len <= maxseg)
13098 tso = 0;
13099 #ifdef INET6
13100 if (MHLEN < hdrlen + max_linkhdr)
13101 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
13102 else
13103 #endif
13104 m = m_gethdr(M_NOWAIT, MT_DATA);
13105
13106 if (m == NULL) {
13107 BBR_STAT_INC(bbr_failed_mbuf_aloc);
13108 bbr_log_enobuf_jmp(bbr, len, cts, __LINE__, len, 0, 0);
13109 SOCK_SENDBUF_UNLOCK(so);
13110 error = ENOBUFS;
13111 sack_rxmit = 0;
13112 goto out;
13113 }
13114 m->m_data += max_linkhdr;
13115 m->m_len = hdrlen;
13116 /*
13117 * Start the m_copy functions from the closest mbuf to the
13118 * sb_offset in the socket buffer chain.
13119 */
13120 if ((sb_offset > sbavail(sb)) || ((len + sb_offset) > sbavail(sb))) {
13121 #ifdef BBR_INVARIANTS
13122 if ((len + sb_offset) > (sbavail(sb) + ((flags & (TH_FIN | TH_SYN)) ? 1 : 0)))
13123 panic("tp:%p bbr:%p len:%u sb_offset:%u sbavail:%u rsm:%p %u:%u:%u",
13124 tp, bbr, len, sb_offset, sbavail(sb), rsm,
13125 doing_retran_from,
13126 picked_up_retran,
13127 doing_tlp);
13128
13129 #endif
13130 /*
13131 * In this messed up situation we have two choices,
13132 * a) pretend the send worked, and just start timers
13133 * and what not (not good since that may lead us
13134 * back here a lot). <or> b) Send the lowest segment
13135 * in the map. <or> c) Drop the connection. Lets do
13136 * <b> which if it continues to happen will lead to
13137 * <c> via timeouts.
13138 */
13139 BBR_STAT_INC(bbr_offset_recovery);
13140 rsm = TAILQ_FIRST(&bbr->r_ctl.rc_map);
13141 sb_offset = 0;
13142 if (rsm == NULL) {
13143 sack_rxmit = 0;
13144 len = sbavail(sb);
13145 } else {
13146 sack_rxmit = 1;
13147 if (rsm->r_start != tp->snd_una) {
13148 /*
13149 * Things are really messed up, <c>
13150 * is the only thing to do.
13151 */
13152 BBR_STAT_INC(bbr_offset_drop);
13153 SOCK_SENDBUF_UNLOCK(so);
13154 (void)m_free(m);
13155 return (-EFAULT); /* tcp_drop() */
13156 }
13157 len = rsm->r_end - rsm->r_start;
13158 }
13159 if (len > sbavail(sb))
13160 len = sbavail(sb);
13161 if (len > maxseg)
13162 len = maxseg;
13163 }
13164 mb = sbsndptr_noadv(sb, sb_offset, &moff);
13165 if (len <= MHLEN - hdrlen - max_linkhdr && !hw_tls) {
13166 m_copydata(mb, moff, (int)len,
13167 mtod(m, caddr_t)+hdrlen);
13168 if (rsm == NULL)
13169 sbsndptr_adv(sb, mb, len);
13170 m->m_len += len;
13171 } else {
13172 struct sockbuf *msb;
13173
13174 if (rsm)
13175 msb = NULL;
13176 else
13177 msb = sb;
13178 #ifdef BBR_INVARIANTS
13179 if ((len + moff) > (sbavail(sb) + ((flags & (TH_FIN | TH_SYN)) ? 1 : 0))) {
13180 if (rsm) {
13181 panic("tp:%p bbr:%p len:%u moff:%u sbavail:%u rsm:%p snd_una:%u rsm_start:%u flg:%x %u:%u:%u sr:%d ",
13182 tp, bbr, len, moff,
13183 sbavail(sb), rsm,
13184 tp->snd_una, rsm->r_flags, rsm->r_start,
13185 doing_retran_from,
13186 picked_up_retran,
13187 doing_tlp, sack_rxmit);
13188 } else {
13189 panic("tp:%p bbr:%p len:%u moff:%u sbavail:%u sb_offset:%u snd_una:%u",
13190 tp, bbr, len, moff, sbavail(sb), sb_offset, tp->snd_una);
13191 }
13192 }
13193 #endif
13194 m->m_next = tcp_m_copym(
13195 mb, moff, &len,
13196 if_hw_tsomaxsegcount,
13197 if_hw_tsomaxsegsize, msb,
13198 ((rsm == NULL) ? hw_tls : 0)
13199 #ifdef NETFLIX_COPY_ARGS
13200 , NULL, NULL
13201 #endif
13202 );
13203 if (len <= maxseg) {
13204 /*
13205 * Must have ran out of mbufs for the copy
13206 * shorten it to no longer need tso. Lets
13207 * not put on sendalot since we are low on
13208 * mbufs.
13209 */
13210 tso = 0;
13211 }
13212 if (m->m_next == NULL) {
13213 SOCK_SENDBUF_UNLOCK(so);
13214 (void)m_free(m);
13215 error = ENOBUFS;
13216 sack_rxmit = 0;
13217 goto out;
13218 }
13219 }
13220 #ifdef BBR_INVARIANTS
13221 if (tso && len < maxseg) {
13222 panic("tp:%p tso on, but len:%d < maxseg:%d",
13223 tp, len, maxseg);
13224 }
13225 if (tso && if_hw_tsomaxsegcount) {
13226 int32_t seg_cnt = 0;
13227 struct mbuf *foo;
13228
13229 foo = m;
13230 while (foo) {
13231 seg_cnt++;
13232 foo = foo->m_next;
13233 }
13234 if (seg_cnt > if_hw_tsomaxsegcount) {
13235 panic("seg_cnt:%d > max:%d", seg_cnt, if_hw_tsomaxsegcount);
13236 }
13237 }
13238 #endif
13239 /*
13240 * If we're sending everything we've got, set PUSH. (This
13241 * will keep happy those implementations which only give
13242 * data to the user when a buffer fills or a PUSH comes in.)
13243 */
13244 if (sb_offset + len == sbused(sb) &&
13245 sbused(sb) &&
13246 !(flags & TH_SYN)) {
13247 flags |= TH_PUSH;
13248 }
13249 SOCK_SENDBUF_UNLOCK(so);
13250 } else {
13251 SOCK_SENDBUF_UNLOCK(so);
13252 if (tp->t_flags & TF_ACKNOW)
13253 KMOD_TCPSTAT_INC(tcps_sndacks);
13254 else if (flags & (TH_SYN | TH_FIN | TH_RST))
13255 KMOD_TCPSTAT_INC(tcps_sndctrl);
13256 else
13257 KMOD_TCPSTAT_INC(tcps_sndwinup);
13258
13259 m = m_gethdr(M_NOWAIT, MT_DATA);
13260 if (m == NULL) {
13261 BBR_STAT_INC(bbr_failed_mbuf_aloc);
13262 bbr_log_enobuf_jmp(bbr, len, cts, __LINE__, len, 0, 0);
13263 error = ENOBUFS;
13264 /* Fudge the send time since we could not send */
13265 sack_rxmit = 0;
13266 goto out;
13267 }
13268 #ifdef INET6
13269 if (isipv6 && (MHLEN < hdrlen + max_linkhdr) &&
13270 MHLEN >= hdrlen) {
13271 M_ALIGN(m, hdrlen);
13272 } else
13273 #endif
13274 m->m_data += max_linkhdr;
13275 m->m_len = hdrlen;
13276 }
13277 SOCK_SENDBUF_UNLOCK_ASSERT(so);
13278 m->m_pkthdr.rcvif = (struct ifnet *)0;
13279 #ifdef MAC
13280 mac_inpcb_create_mbuf(inp, m);
13281 #endif
13282 #ifdef INET6
13283 if (isipv6) {
13284 ip6 = mtod(m, struct ip6_hdr *);
13285 if (tp->t_port) {
13286 udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
13287 udp->uh_sport = htons(V_tcp_udp_tunneling_port);
13288 udp->uh_dport = tp->t_port;
13289 ulen = hdrlen + len - sizeof(struct ip6_hdr);
13290 udp->uh_ulen = htons(ulen);
13291 th = (struct tcphdr *)(udp + 1);
13292 } else {
13293 th = (struct tcphdr *)(ip6 + 1);
13294 }
13295 tcpip_fillheaders(inp, tp->t_port, ip6, th);
13296 } else
13297 #endif /* INET6 */
13298 {
13299 ip = mtod(m, struct ip *);
13300 if (tp->t_port) {
13301 udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
13302 udp->uh_sport = htons(V_tcp_udp_tunneling_port);
13303 udp->uh_dport = tp->t_port;
13304 ulen = hdrlen + len - sizeof(struct ip);
13305 udp->uh_ulen = htons(ulen);
13306 th = (struct tcphdr *)(udp + 1);
13307 } else {
13308 th = (struct tcphdr *)(ip + 1);
13309 }
13310 tcpip_fillheaders(inp, tp->t_port, ip, th);
13311 }
13312 /*
13313 * If we are doing retransmissions, then snd_nxt will not reflect
13314 * the first unsent octet. For ACK only packets, we do not want the
13315 * sequence number of the retransmitted packet, we want the sequence
13316 * number of the next unsent octet. So, if there is no data (and no
13317 * SYN or FIN), use snd_max instead of snd_nxt when filling in
13318 * ti_seq. But if we are in persist state, snd_max might reflect
13319 * one byte beyond the right edge of the window, so use snd_nxt in
13320 * that case, since we know we aren't doing a retransmission.
13321 * (retransmit and persist are mutually exclusive...)
13322 */
13323 if (sack_rxmit == 0) {
13324 if (len && ((flags & (TH_FIN | TH_SYN | TH_RST)) == 0)) {
13325 /* New data (including new persists) */
13326 th->th_seq = htonl(tp->snd_max);
13327 bbr_seq = tp->snd_max;
13328 } else if (flags & TH_SYN) {
13329 /* Syn's always send from iss */
13330 th->th_seq = htonl(tp->iss);
13331 bbr_seq = tp->iss;
13332 } else if (flags & TH_FIN) {
13333 if (flags & TH_FIN && tp->t_flags & TF_SENTFIN) {
13334 /*
13335 * If we sent the fin already its 1 minus
13336 * snd_max
13337 */
13338 th->th_seq = (htonl(tp->snd_max - 1));
13339 bbr_seq = (tp->snd_max - 1);
13340 } else {
13341 /* First time FIN use snd_max */
13342 th->th_seq = htonl(tp->snd_max);
13343 bbr_seq = tp->snd_max;
13344 }
13345 } else {
13346 /*
13347 * len == 0 and not persist we use snd_max, sending
13348 * an ack unless we have sent the fin then its 1
13349 * minus.
13350 */
13351 /*
13352 * XXXRRS Question if we are in persists and we have
13353 * nothing outstanding to send and we have not sent
13354 * a FIN, we will send an ACK. In such a case it
13355 * might be better to send (tp->snd_una - 1) which
13356 * would force the peer to ack.
13357 */
13358 if (tp->t_flags & TF_SENTFIN) {
13359 th->th_seq = htonl(tp->snd_max - 1);
13360 bbr_seq = (tp->snd_max - 1);
13361 } else {
13362 th->th_seq = htonl(tp->snd_max);
13363 bbr_seq = tp->snd_max;
13364 }
13365 }
13366 } else {
13367 /* All retransmits use the rsm to guide the send */
13368 th->th_seq = htonl(rsm->r_start);
13369 bbr_seq = rsm->r_start;
13370 }
13371 th->th_ack = htonl(tp->rcv_nxt);
13372 if (optlen) {
13373 bcopy(opt, th + 1, optlen);
13374 th->th_off = (sizeof(struct tcphdr) + optlen) >> 2;
13375 }
13376 tcp_set_flags(th, flags);
13377 /*
13378 * Calculate receive window. Don't shrink window, but avoid silly
13379 * window syndrome.
13380 */
13381 if ((flags & TH_RST) || ((recwin < (so->so_rcv.sb_hiwat / 4) &&
13382 recwin < maxseg)))
13383 recwin = 0;
13384 if (SEQ_GT(tp->rcv_adv, tp->rcv_nxt) &&
13385 recwin < (tp->rcv_adv - tp->rcv_nxt))
13386 recwin = (tp->rcv_adv - tp->rcv_nxt);
13387 if (recwin > TCP_MAXWIN << tp->rcv_scale)
13388 recwin = TCP_MAXWIN << tp->rcv_scale;
13389
13390 /*
13391 * According to RFC1323 the window field in a SYN (i.e., a <SYN> or
13392 * <SYN,ACK>) segment itself is never scaled. The <SYN,ACK> case is
13393 * handled in syncache.
13394 */
13395 if (flags & TH_SYN)
13396 th->th_win = htons((u_short)
13397 (min(sbspace(&so->so_rcv), TCP_MAXWIN)));
13398 else {
13399 /* Avoid shrinking window with window scaling. */
13400 recwin = roundup2(recwin, 1 << tp->rcv_scale);
13401 th->th_win = htons((u_short)(recwin >> tp->rcv_scale));
13402 }
13403 /*
13404 * Adjust the RXWIN0SENT flag - indicate that we have advertised a 0
13405 * window. This may cause the remote transmitter to stall. This
13406 * flag tells soreceive() to disable delayed acknowledgements when
13407 * draining the buffer. This can occur if the receiver is
13408 * attempting to read more data than can be buffered prior to
13409 * transmitting on the connection.
13410 */
13411 if (th->th_win == 0) {
13412 tp->t_sndzerowin++;
13413 tp->t_flags |= TF_RXWIN0SENT;
13414 } else
13415 tp->t_flags &= ~TF_RXWIN0SENT;
13416 /*
13417 * We don't support urgent data, but drag along
13418 * the pointer in case of a stack switch.
13419 */
13420 tp->snd_up = tp->snd_una;
13421 /*
13422 * Put TCP length in extended header, and then checksum extended
13423 * header and data.
13424 */
13425 m->m_pkthdr.len = hdrlen + len; /* in6_cksum() need this */
13426
13427 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
13428 if (to.to_flags & TOF_SIGNATURE) {
13429 /*
13430 * Calculate MD5 signature and put it into the place
13431 * determined before. NOTE: since TCP options buffer doesn't
13432 * point into mbuf's data, calculate offset and use it.
13433 */
13434 if (!TCPMD5_ENABLED() || TCPMD5_OUTPUT(m, th,
13435 (u_char *)(th + 1) + (to.to_signature - opt)) != 0) {
13436 /*
13437 * Do not send segment if the calculation of MD5
13438 * digest has failed.
13439 */
13440 goto out;
13441 }
13442 }
13443 #endif
13444
13445 #ifdef INET6
13446 if (isipv6) {
13447 /*
13448 * ip6_plen is not need to be filled now, and will be filled
13449 * in ip6_output.
13450 */
13451 if (tp->t_port) {
13452 m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
13453 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
13454 udp->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
13455 th->th_sum = htons(0);
13456 UDPSTAT_INC(udps_opackets);
13457 } else {
13458 csum_flags = m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
13459 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
13460 th->th_sum = in6_cksum_pseudo(ip6, sizeof(struct tcphdr) +
13461 optlen + len, IPPROTO_TCP, 0);
13462 }
13463 }
13464 #endif
13465 #if defined(INET6) && defined(INET)
13466 else
13467 #endif
13468 #ifdef INET
13469 {
13470 if (tp->t_port) {
13471 m->m_pkthdr.csum_flags = CSUM_UDP;
13472 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
13473 udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
13474 ip->ip_dst.s_addr, htons(ulen + IPPROTO_UDP));
13475 th->th_sum = htons(0);
13476 UDPSTAT_INC(udps_opackets);
13477 } else {
13478 csum_flags = m->m_pkthdr.csum_flags = CSUM_TCP;
13479 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
13480 th->th_sum = in_pseudo(ip->ip_src.s_addr,
13481 ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) +
13482 IPPROTO_TCP + len + optlen));
13483 }
13484 /* IP version must be set here for ipv4/ipv6 checking later */
13485 KASSERT(ip->ip_v == IPVERSION,
13486 ("%s: IP version incorrect: %d", __func__, ip->ip_v));
13487 }
13488 #endif
13489
13490 /*
13491 * Enable TSO and specify the size of the segments. The TCP pseudo
13492 * header checksum is always provided. XXX: Fixme: This is currently
13493 * not the case for IPv6.
13494 */
13495 if (tso) {
13496 KASSERT(len > maxseg,
13497 ("%s: len:%d <= tso_segsz:%d", __func__, len, maxseg));
13498 m->m_pkthdr.csum_flags |= CSUM_TSO;
13499 csum_flags |= CSUM_TSO;
13500 m->m_pkthdr.tso_segsz = maxseg;
13501 }
13502 KASSERT(len + hdrlen == m_length(m, NULL),
13503 ("%s: mbuf chain different than expected: %d + %u != %u",
13504 __func__, len, hdrlen, m_length(m, NULL)));
13505
13506 #ifdef TCP_HHOOK
13507 /* Run HHOOK_TC_ESTABLISHED_OUT helper hooks. */
13508 hhook_run_tcp_est_out(tp, th, &to, len, tso);
13509 #endif
13510
13511 /* Log to the black box */
13512 if (tcp_bblogging_on(tp)) {
13513 union tcp_log_stackspecific log;
13514
13515 bbr_fill_in_logging_data(bbr, &log.u_bbr, cts);
13516 /* Record info on type of transmission */
13517 log.u_bbr.flex1 = bbr->r_ctl.rc_hptsi_agg_delay;
13518 log.u_bbr.flex2 = (bbr->r_recovery_bw << 3);
13519 log.u_bbr.flex3 = maxseg;
13520 log.u_bbr.flex4 = delay_calc;
13521 log.u_bbr.flex5 = bbr->rc_past_init_win;
13522 log.u_bbr.flex5 <<= 1;
13523 log.u_bbr.flex5 |= bbr->rc_no_pacing;
13524 log.u_bbr.flex5 <<= 29;
13525 log.u_bbr.flex5 |= tp->t_maxseg;
13526 log.u_bbr.flex6 = bbr->r_ctl.rc_pace_max_segs;
13527 log.u_bbr.flex7 = (bbr->rc_bbr_state << 8) | bbr_state_val(bbr);
13528 /* lets poke in the low and the high here for debugging */
13529 log.u_bbr.pkts_out = bbr->rc_tp->t_maxseg;
13530 if (rsm || sack_rxmit) {
13531 if (doing_tlp)
13532 log.u_bbr.flex8 = 2;
13533 else
13534 log.u_bbr.flex8 = 1;
13535 } else {
13536 log.u_bbr.flex8 = 0;
13537 }
13538 lgb = tcp_log_event(tp, th, &so->so_rcv, &so->so_snd, TCP_LOG_OUT, ERRNO_UNK,
13539 len, &log, false, NULL, NULL, 0, tv);
13540 } else {
13541 lgb = NULL;
13542 }
13543 /*
13544 * Fill in IP length and desired time to live and send to IP level.
13545 * There should be a better way to handle ttl and tos; we could keep
13546 * them in the template, but need a way to checksum without them.
13547 */
13548 /*
13549 * m->m_pkthdr.len should have been set before cksum calcuration,
13550 * because in6_cksum() need it.
13551 */
13552 #ifdef INET6
13553 if (isipv6) {
13554 /*
13555 * we separately set hoplimit for every segment, since the
13556 * user might want to change the value via setsockopt. Also,
13557 * desired default hop limit might be changed via Neighbor
13558 * Discovery.
13559 */
13560 ip6->ip6_hlim = in6_selecthlim(inp, NULL);
13561
13562 /*
13563 * Set the packet size here for the benefit of DTrace
13564 * probes. ip6_output() will set it properly; it's supposed
13565 * to include the option header lengths as well.
13566 */
13567 ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
13568
13569 if (V_path_mtu_discovery && maxseg > V_tcp_minmss)
13570 tp->t_flags2 |= TF2_PLPMTU_PMTUD;
13571 else
13572 tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
13573
13574 if (tp->t_state == TCPS_SYN_SENT)
13575 TCP_PROBE5(connect__request, NULL, tp, ip6, tp, th);
13576
13577 TCP_PROBE5(send, NULL, tp, ip6, tp, th);
13578 /* TODO: IPv6 IP6TOS_ECT bit on */
13579 error = ip6_output(m, inp->in6p_outputopts,
13580 &inp->inp_route6,
13581 ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0),
13582 NULL, NULL, inp);
13583
13584 if (error == EMSGSIZE && inp->inp_route6.ro_nh != NULL)
13585 mtu = inp->inp_route6.ro_nh->nh_mtu;
13586 }
13587 #endif /* INET6 */
13588 #if defined(INET) && defined(INET6)
13589 else
13590 #endif
13591 #ifdef INET
13592 {
13593 ip->ip_len = htons(m->m_pkthdr.len);
13594 #ifdef INET6
13595 if (isipv6)
13596 ip->ip_ttl = in6_selecthlim(inp, NULL);
13597 #endif /* INET6 */
13598 /*
13599 * If we do path MTU discovery, then we set DF on every
13600 * packet. This might not be the best thing to do according
13601 * to RFC3390 Section 2. However the tcp hostcache migitates
13602 * the problem so it affects only the first tcp connection
13603 * with a host.
13604 *
13605 * NB: Don't set DF on small MTU/MSS to have a safe
13606 * fallback.
13607 */
13608 if (V_path_mtu_discovery && tp->t_maxseg > V_tcp_minmss) {
13609 tp->t_flags2 |= TF2_PLPMTU_PMTUD;
13610 if (tp->t_port == 0 || len < V_tcp_minmss) {
13611 ip->ip_off |= htons(IP_DF);
13612 }
13613 } else {
13614 tp->t_flags2 &= ~TF2_PLPMTU_PMTUD;
13615 }
13616
13617 if (tp->t_state == TCPS_SYN_SENT)
13618 TCP_PROBE5(connect__request, NULL, tp, ip, tp, th);
13619
13620 TCP_PROBE5(send, NULL, tp, ip, tp, th);
13621
13622 error = ip_output(m, inp->inp_options, &inp->inp_route,
13623 ((rsm || sack_rxmit) ? IP_NO_SND_TAG_RL : 0), 0,
13624 inp);
13625 if (error == EMSGSIZE && inp->inp_route.ro_nh != NULL)
13626 mtu = inp->inp_route.ro_nh->nh_mtu;
13627 }
13628 #endif /* INET */
13629 if (lgb) {
13630 lgb->tlb_errno = error;
13631 lgb = NULL;
13632 }
13633
13634 out:
13635 /*
13636 * In transmit state, time the transmission and arrange for the
13637 * retransmit. In persist state, just set snd_max.
13638 */
13639 if (error == 0) {
13640 tcp_account_for_send(tp, len, (rsm != NULL), doing_tlp, hw_tls);
13641 if (TCPS_HAVEESTABLISHED(tp->t_state) &&
13642 (tp->t_flags & TF_SACK_PERMIT) &&
13643 tp->rcv_numsacks > 0)
13644 tcp_clean_dsack_blocks(tp);
13645 /* We sent an ack clear the bbr_segs_rcvd count */
13646 bbr->output_error_seen = 0;
13647 bbr->oerror_cnt = 0;
13648 bbr->bbr_segs_rcvd = 0;
13649 if (len == 0)
13650 counter_u64_add(bbr_out_size[TCP_MSS_ACCT_SNDACK], 1);
13651 /* Do accounting for new sends */
13652 if ((len > 0) && (rsm == NULL)) {
13653 int idx;
13654 if (tp->snd_una == tp->snd_max) {
13655 /*
13656 * Special case to match google, when
13657 * nothing is in flight the delivered
13658 * time does get updated to the current
13659 * time (see tcp_rate_bsd.c).
13660 */
13661 bbr->r_ctl.rc_del_time = cts;
13662 }
13663 if (len >= maxseg) {
13664 idx = (len / maxseg) + 3;
13665 if (idx >= TCP_MSS_ACCT_ATIMER)
13666 counter_u64_add(bbr_out_size[(TCP_MSS_ACCT_ATIMER - 1)], 1);
13667 else
13668 counter_u64_add(bbr_out_size[idx], 1);
13669 } else {
13670 /* smaller than a MSS */
13671 idx = len / (bbr_hptsi_bytes_min - bbr->rc_last_options);
13672 if (idx >= TCP_MSS_SMALL_MAX_SIZE_DIV)
13673 idx = (TCP_MSS_SMALL_MAX_SIZE_DIV - 1);
13674 counter_u64_add(bbr_out_size[(idx + TCP_MSS_SMALL_SIZE_OFF)], 1);
13675 }
13676 }
13677 }
13678 abandon = 0;
13679 /*
13680 * We must do the send accounting before we log the output,
13681 * otherwise the state of the rsm could change and we account to the
13682 * wrong bucket.
13683 */
13684 if (len > 0) {
13685 bbr_do_send_accounting(tp, bbr, rsm, len, error);
13686 if (error == 0) {
13687 if (tp->snd_una == tp->snd_max)
13688 bbr->r_ctl.rc_tlp_rxt_last_time = cts;
13689 }
13690 }
13691 bbr_log_output(bbr, tp, &to, len, bbr_seq, (uint8_t) flags, error,
13692 cts, mb, &abandon, rsm, 0, sb);
13693 if (abandon) {
13694 /*
13695 * If bbr_log_output destroys the TCB or sees a TH_RST being
13696 * sent we should hit this condition.
13697 */
13698 return (0);
13699 }
13700 if (bbr->rc_in_persist == 0) {
13701 /*
13702 * Advance snd_nxt over sequence space of this segment.
13703 */
13704 if (error)
13705 /* We don't log or do anything with errors */
13706 goto skip_upd;
13707
13708 if (tp->snd_una == tp->snd_max &&
13709 (len || (flags & (TH_SYN | TH_FIN)))) {
13710 /*
13711 * Update the time we just added data since none was
13712 * outstanding.
13713 */
13714 bbr_log_progress_event(bbr, tp, ticks, PROGRESS_START, __LINE__);
13715 bbr->rc_tp->t_acktime = ticks;
13716 }
13717 if (flags & (TH_SYN | TH_FIN) && (rsm == NULL)) {
13718 if (flags & TH_SYN) {
13719 /*
13720 * Smack the snd_max to iss + 1
13721 * if its a FO we will add len below.
13722 */
13723 tp->snd_max = tp->iss + 1;
13724 }
13725 if ((flags & TH_FIN) && ((tp->t_flags & TF_SENTFIN) == 0)) {
13726 tp->snd_max++;
13727 tp->t_flags |= TF_SENTFIN;
13728 }
13729 }
13730 if (sack_rxmit == 0)
13731 tp->snd_max += len;
13732 skip_upd:
13733 if ((error == 0) && len)
13734 tot_len += len;
13735 } else {
13736 /* Persists case */
13737 int32_t xlen = len;
13738
13739 if (error)
13740 goto nomore;
13741
13742 if (flags & TH_SYN)
13743 ++xlen;
13744 if ((flags & TH_FIN) && ((tp->t_flags & TF_SENTFIN) == 0)) {
13745 ++xlen;
13746 tp->t_flags |= TF_SENTFIN;
13747 }
13748 if (xlen && (tp->snd_una == tp->snd_max)) {
13749 /*
13750 * Update the time we just added data since none was
13751 * outstanding.
13752 */
13753 bbr_log_progress_event(bbr, tp, ticks, PROGRESS_START, __LINE__);
13754 bbr->rc_tp->t_acktime = ticks;
13755 }
13756 if (sack_rxmit == 0)
13757 tp->snd_max += xlen;
13758 tot_len += (len + optlen + ipoptlen);
13759 }
13760 nomore:
13761 if (error) {
13762 /*
13763 * Failures do not advance the seq counter above. For the
13764 * case of ENOBUFS we will fall out and become ack-clocked.
13765 * capping the cwnd at the current flight.
13766 * Everything else will just have to retransmit with the timer
13767 * (no pacer).
13768 */
13769 SOCK_SENDBUF_UNLOCK_ASSERT(so);
13770 BBR_STAT_INC(bbr_saw_oerr);
13771 /* Clear all delay/early tracks */
13772 bbr->r_ctl.rc_hptsi_agg_delay = 0;
13773 bbr->r_ctl.rc_agg_early = 0;
13774 bbr->r_agg_early_set = 0;
13775 bbr->output_error_seen = 1;
13776 if (bbr->oerror_cnt < 0xf)
13777 bbr->oerror_cnt++;
13778 if (bbr_max_net_error_cnt && (bbr->oerror_cnt >= bbr_max_net_error_cnt)) {
13779 /* drop the session */
13780 return (-ENETDOWN);
13781 }
13782 switch (error) {
13783 case ENOBUFS:
13784 /*
13785 * Make this guy have to get ack's to send
13786 * more but lets make sure we don't
13787 * slam him below a T-O (1MSS).
13788 */
13789 if (bbr->rc_bbr_state != BBR_STATE_PROBE_RTT) {
13790 tp->snd_cwnd = ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
13791 bbr->r_ctl.rc_lost_bytes)) - maxseg;
13792 if (tp->snd_cwnd < maxseg)
13793 tp->snd_cwnd = maxseg;
13794 }
13795 slot = (bbr_error_base_paceout + 1) << bbr->oerror_cnt;
13796 BBR_STAT_INC(bbr_saw_enobuf);
13797 if (bbr->bbr_hdrw_pacing)
13798 counter_u64_add(bbr_hdwr_pacing_enobuf, 1);
13799 else
13800 counter_u64_add(bbr_nohdwr_pacing_enobuf, 1);
13801 /*
13802 * Here even in the enobuf's case we want to do our
13803 * state update. The reason being we may have been
13804 * called by the input function. If so we have had
13805 * things change.
13806 */
13807 error = 0;
13808 goto enobufs;
13809 case EMSGSIZE:
13810 /*
13811 * For some reason the interface we used initially
13812 * to send segments changed to another or lowered
13813 * its MTU. If TSO was active we either got an
13814 * interface without TSO capabilits or TSO was
13815 * turned off. If we obtained mtu from ip_output()
13816 * then update it and try again.
13817 */
13818 /* Turn on tracing (or try to) */
13819 {
13820 int old_maxseg;
13821
13822 old_maxseg = tp->t_maxseg;
13823 BBR_STAT_INC(bbr_saw_emsgsiz);
13824 bbr_log_msgsize_fail(bbr, tp, len, maxseg, mtu, csum_flags, tso, cts);
13825 if (mtu != 0)
13826 tcp_mss_update(tp, -1, mtu, NULL, NULL);
13827 if (old_maxseg <= tp->t_maxseg) {
13828 /* Huh it did not shrink? */
13829 tp->t_maxseg = old_maxseg - 40;
13830 if (tp->t_maxseg < V_tcp_mssdflt) {
13831 /*
13832 * The MSS is so small we should not
13833 * process incoming SACK's since we are
13834 * subject to attack in such a case.
13835 */
13836 tp->t_flags2 |= TF2_PROC_SACK_PROHIBIT;
13837 } else {
13838 tp->t_flags2 &= ~TF2_PROC_SACK_PROHIBIT;
13839 }
13840 bbr_log_msgsize_fail(bbr, tp, len, maxseg, mtu, 0, tso, cts);
13841 }
13842 /*
13843 * Nuke all other things that can interfere
13844 * with slot
13845 */
13846 if ((tot_len + len) && (len >= tp->t_maxseg)) {
13847 slot = bbr_get_pacing_delay(bbr,
13848 bbr->r_ctl.rc_bbr_hptsi_gain,
13849 (tot_len + len), cts, 0);
13850 if (slot < bbr_error_base_paceout)
13851 slot = (bbr_error_base_paceout + 2) << bbr->oerror_cnt;
13852 } else
13853 slot = (bbr_error_base_paceout + 2) << bbr->oerror_cnt;
13854 bbr->rc_output_starts_timer = 1;
13855 bbr_start_hpts_timer(bbr, tp, cts, 10, slot,
13856 tot_len);
13857 return (error);
13858 }
13859 case EPERM:
13860 case EACCES:
13861 tp->t_softerror = error;
13862 /* FALLTHROUGH */
13863 case EHOSTDOWN:
13864 case EHOSTUNREACH:
13865 case ENETDOWN:
13866 case ENETUNREACH:
13867 if (TCPS_HAVERCVDSYN(tp->t_state)) {
13868 tp->t_softerror = error;
13869 error = 0;
13870 }
13871 /* FALLTHROUGH */
13872 default:
13873 slot = (bbr_error_base_paceout + 3) << bbr->oerror_cnt;
13874 bbr->rc_output_starts_timer = 1;
13875 bbr_start_hpts_timer(bbr, tp, cts, 11, slot, 0);
13876 return (error);
13877 }
13878 #ifdef STATS
13879 } else if (((tp->t_flags & TF_GPUTINPROG) == 0) &&
13880 len &&
13881 (rsm == NULL) &&
13882 (bbr->rc_in_persist == 0)) {
13883 tp->gput_seq = bbr_seq;
13884 tp->gput_ack = bbr_seq +
13885 min(sbavail(&so->so_snd) - sb_offset, sendwin);
13886 tp->gput_ts = cts;
13887 tp->t_flags |= TF_GPUTINPROG;
13888 #endif
13889 }
13890 KMOD_TCPSTAT_INC(tcps_sndtotal);
13891 if ((bbr->bbr_hdw_pace_ena) &&
13892 (bbr->bbr_attempt_hdwr_pace == 0) &&
13893 (bbr->rc_past_init_win) &&
13894 (bbr->rc_bbr_state != BBR_STATE_STARTUP) &&
13895 (get_filter_value(&bbr->r_ctl.rc_delrate)) &&
13896 (inp->inp_route.ro_nh &&
13897 inp->inp_route.ro_nh->nh_ifp)) {
13898 /*
13899 * We are past the initial window and
13900 * have at least one measurement so we
13901 * could use hardware pacing if its available.
13902 * We have an interface and we have not attempted
13903 * to setup hardware pacing, lets try to now.
13904 */
13905 uint64_t rate_wanted;
13906 int err = 0;
13907
13908 rate_wanted = bbr_get_hardware_rate(bbr);
13909 bbr->bbr_attempt_hdwr_pace = 1;
13910 bbr->r_ctl.crte = tcp_set_pacing_rate(bbr->rc_tp,
13911 inp->inp_route.ro_nh->nh_ifp,
13912 rate_wanted,
13913 (RS_PACING_GEQ|RS_PACING_SUB_OK),
13914 &err, NULL);
13915 if (bbr->r_ctl.crte) {
13916 bbr_type_log_hdwr_pacing(bbr,
13917 bbr->r_ctl.crte->ptbl->rs_ifp,
13918 rate_wanted,
13919 bbr->r_ctl.crte->rate,
13920 __LINE__, cts, err);
13921 BBR_STAT_INC(bbr_hdwr_rl_add_ok);
13922 counter_u64_add(bbr_flows_nohdwr_pacing, -1);
13923 counter_u64_add(bbr_flows_whdwr_pacing, 1);
13924 bbr->bbr_hdrw_pacing = 1;
13925 /* Now what is our gain status? */
13926 if (bbr->r_ctl.crte->rate < rate_wanted) {
13927 /* We have a problem */
13928 bbr_setup_less_of_rate(bbr, cts,
13929 bbr->r_ctl.crte->rate, rate_wanted);
13930 } else {
13931 /* We are good */
13932 bbr->gain_is_limited = 0;
13933 bbr->skip_gain = 0;
13934 }
13935 tcp_bbr_tso_size_check(bbr, cts);
13936 } else {
13937 bbr_type_log_hdwr_pacing(bbr,
13938 inp->inp_route.ro_nh->nh_ifp,
13939 rate_wanted,
13940 0,
13941 __LINE__, cts, err);
13942 BBR_STAT_INC(bbr_hdwr_rl_add_fail);
13943 }
13944 }
13945 if (bbr->bbr_hdrw_pacing) {
13946 /*
13947 * Worry about cases where the route
13948 * changes or something happened that we
13949 * lost our hardware pacing possibly during
13950 * the last ip_output call.
13951 */
13952 if (inp->inp_snd_tag == NULL) {
13953 /* A change during ip output disabled hw pacing? */
13954 bbr->bbr_hdrw_pacing = 0;
13955 } else if ((inp->inp_route.ro_nh == NULL) ||
13956 (inp->inp_route.ro_nh->nh_ifp != inp->inp_snd_tag->ifp)) {
13957 /*
13958 * We had an interface or route change,
13959 * detach from the current hdwr pacing
13960 * and setup to re-attempt next go
13961 * round.
13962 */
13963 bbr->bbr_hdrw_pacing = 0;
13964 bbr->bbr_attempt_hdwr_pace = 0;
13965 tcp_rel_pacing_rate(bbr->r_ctl.crte, bbr->rc_tp);
13966 tcp_bbr_tso_size_check(bbr, cts);
13967 }
13968 }
13969 /*
13970 * Data sent (as far as we can tell). If this advertises a larger
13971 * window than any other segment, then remember the size of the
13972 * advertised window. Any pending ACK has now been sent.
13973 */
13974 if (SEQ_GT(tp->rcv_nxt + recwin, tp->rcv_adv))
13975 tp->rcv_adv = tp->rcv_nxt + recwin;
13976
13977 tp->last_ack_sent = tp->rcv_nxt;
13978 if ((error == 0) &&
13979 (bbr->r_ctl.rc_pace_max_segs > tp->t_maxseg) &&
13980 (doing_tlp == 0) &&
13981 (tso == 0) &&
13982 (len > 0) &&
13983 ((flags & TH_RST) == 0) &&
13984 ((flags & TH_SYN) == 0) &&
13985 (IN_RECOVERY(tp->t_flags) == 0) &&
13986 (bbr->rc_in_persist == 0) &&
13987 (tot_len < bbr->r_ctl.rc_pace_max_segs)) {
13988 /*
13989 * For non-tso we need to goto again until we have sent out
13990 * enough data to match what we are hptsi out every hptsi
13991 * interval.
13992 */
13993 if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
13994 /* Make sure snd_nxt is drug up */
13995 tp->snd_nxt = tp->snd_max;
13996 }
13997 if (rsm != NULL) {
13998 rsm = NULL;
13999 goto skip_again;
14000 }
14001 rsm = NULL;
14002 sack_rxmit = 0;
14003 tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
14004 goto again;
14005 }
14006 skip_again:
14007 if ((error == 0) && (flags & TH_FIN))
14008 tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_FIN);
14009 if ((error == 0) && (flags & TH_RST))
14010 tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
14011 if (((flags & (TH_RST | TH_SYN | TH_FIN)) == 0) && tot_len) {
14012 /*
14013 * Calculate/Re-Calculate the hptsi slot in usecs based on
14014 * what we have sent so far
14015 */
14016 slot = bbr_get_pacing_delay(bbr, bbr->r_ctl.rc_bbr_hptsi_gain, tot_len, cts, 0);
14017 if (bbr->rc_no_pacing)
14018 slot = 0;
14019 }
14020 tp->t_flags &= ~(TF_ACKNOW | TF_DELACK);
14021 enobufs:
14022 if (bbr->rc_use_google == 0)
14023 bbr_check_bbr_for_state(bbr, cts, __LINE__, 0);
14024 bbr_cwnd_limiting(tp, bbr, ctf_flight_size(tp, (bbr->r_ctl.rc_sacked +
14025 bbr->r_ctl.rc_lost_bytes)));
14026 bbr->rc_output_starts_timer = 1;
14027 if (bbr->bbr_use_rack_cheat &&
14028 (more_to_rxt ||
14029 ((bbr->r_ctl.rc_resend = bbr_check_recovery_mode(tp, bbr, cts)) != NULL))) {
14030 /* Rack cheats and shotguns out all rxt's 1ms apart */
14031 if (slot > 1000)
14032 slot = 1000;
14033 }
14034 if (bbr->bbr_hdrw_pacing && (bbr->hw_pacing_set == 0)) {
14035 /*
14036 * We don't change the tso size until some number of sends
14037 * to give the hardware commands time to get down
14038 * to the interface.
14039 */
14040 bbr->r_ctl.bbr_hdwr_cnt_noset_snt++;
14041 if (bbr->r_ctl.bbr_hdwr_cnt_noset_snt >= bbr_hdwr_pacing_delay_cnt) {
14042 bbr->hw_pacing_set = 1;
14043 tcp_bbr_tso_size_check(bbr, cts);
14044 }
14045 }
14046 bbr_start_hpts_timer(bbr, tp, cts, 12, slot, tot_len);
14047 if (SEQ_LT(tp->snd_nxt, tp->snd_max)) {
14048 /* Make sure snd_nxt is drug up */
14049 tp->snd_nxt = tp->snd_max;
14050 }
14051 return (error);
14052
14053 }
14054
14055 /*
14056 * See bbr_output_wtime() for return values.
14057 */
14058 static int
bbr_output(struct tcpcb * tp)14059 bbr_output(struct tcpcb *tp)
14060 {
14061 int32_t ret;
14062 struct timeval tv;
14063
14064 NET_EPOCH_ASSERT();
14065
14066 INP_WLOCK_ASSERT(tptoinpcb(tp));
14067 (void)tcp_get_usecs(&tv);
14068 ret = bbr_output_wtime(tp, &tv);
14069 return (ret);
14070 }
14071
14072 static void
bbr_mtu_chg(struct tcpcb * tp)14073 bbr_mtu_chg(struct tcpcb *tp)
14074 {
14075 struct tcp_bbr *bbr;
14076 struct bbr_sendmap *rsm, *frsm = NULL;
14077 uint32_t maxseg;
14078
14079 /*
14080 * The MTU has changed. a) Clear the sack filter. b) Mark everything
14081 * over the current size as SACK_PASS so a retransmit will occur.
14082 */
14083
14084 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
14085 maxseg = tp->t_maxseg - bbr->rc_last_options;
14086 sack_filter_clear(&bbr->r_ctl.bbr_sf, tp->snd_una);
14087 TAILQ_FOREACH(rsm, &bbr->r_ctl.rc_map, r_next) {
14088 /* Don't mess with ones acked (by sack?) */
14089 if (rsm->r_flags & BBR_ACKED)
14090 continue;
14091 if ((rsm->r_end - rsm->r_start) > maxseg) {
14092 /*
14093 * We mark sack-passed on all the previous large
14094 * sends we did. This will force them to retransmit.
14095 */
14096 rsm->r_flags |= BBR_SACK_PASSED;
14097 if (((rsm->r_flags & BBR_MARKED_LOST) == 0) &&
14098 bbr_is_lost(bbr, rsm, bbr->r_ctl.rc_rcvtime)) {
14099 bbr->r_ctl.rc_lost_bytes += rsm->r_end - rsm->r_start;
14100 bbr->r_ctl.rc_lost += rsm->r_end - rsm->r_start;
14101 rsm->r_flags |= BBR_MARKED_LOST;
14102 }
14103 if (frsm == NULL)
14104 frsm = rsm;
14105 }
14106 }
14107 if (frsm) {
14108 bbr->r_ctl.rc_resend = frsm;
14109 }
14110 }
14111
14112 static int
bbr_pru_options(struct tcpcb * tp,int flags)14113 bbr_pru_options(struct tcpcb *tp, int flags)
14114 {
14115 if (flags & PRUS_OOB)
14116 return (EOPNOTSUPP);
14117 return (0);
14118 }
14119
14120 static void
bbr_switch_failed(struct tcpcb * tp)14121 bbr_switch_failed(struct tcpcb *tp)
14122 {
14123 /*
14124 * If a switch fails we only need to
14125 * make sure mbuf_queuing is still in place.
14126 * We also need to make sure we are still in
14127 * ticks granularity (though we should probably
14128 * change bbr to go to USECs).
14129 *
14130 * For timers we need to see if we are still in the
14131 * pacer (if our flags are up) if so we are good, if
14132 * not we need to get back into the pacer.
14133 */
14134 struct timeval tv;
14135 uint32_t cts;
14136 uint32_t toval;
14137 struct tcp_bbr *bbr;
14138 struct hpts_diag diag;
14139
14140 tp->t_flags2 |= TF2_CANNOT_DO_ECN;
14141 tp->t_flags2 |= TF2_SUPPORTS_MBUFQ;
14142 tcp_change_time_units(tp, TCP_TMR_GRANULARITY_TICKS);
14143 if (tp->t_in_hpts > IHPTS_NONE) {
14144 return;
14145 }
14146 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
14147 cts = tcp_get_usecs(&tv);
14148 if (bbr->r_ctl.rc_hpts_flags & PACE_PKT_OUTPUT) {
14149 if (TSTMP_GT(bbr->rc_pacer_started, cts)) {
14150 toval = bbr->rc_pacer_started - cts;
14151 } else {
14152 /* one slot please */
14153 toval = HPTS_TICKS_PER_SLOT;
14154 }
14155 } else if (bbr->r_ctl.rc_hpts_flags & PACE_TMR_MASK) {
14156 if (TSTMP_GT(bbr->r_ctl.rc_timer_exp, cts)) {
14157 toval = bbr->r_ctl.rc_timer_exp - cts;
14158 } else {
14159 /* one slot please */
14160 toval = HPTS_TICKS_PER_SLOT;
14161 }
14162 } else
14163 toval = HPTS_TICKS_PER_SLOT;
14164 (void)tcp_hpts_insert_diag(tp, HPTS_USEC_TO_SLOTS(toval),
14165 __LINE__, &diag);
14166 bbr_log_hpts_diag(bbr, cts, &diag);
14167 }
14168
14169 struct tcp_function_block __tcp_bbr = {
14170 .tfb_tcp_block_name = __XSTRING(STACKNAME),
14171 .tfb_tcp_output = bbr_output,
14172 .tfb_do_queued_segments = ctf_do_queued_segments,
14173 .tfb_do_segment_nounlock = bbr_do_segment_nounlock,
14174 .tfb_tcp_do_segment = bbr_do_segment,
14175 .tfb_tcp_ctloutput = bbr_ctloutput,
14176 .tfb_tcp_fb_init = bbr_init,
14177 .tfb_tcp_fb_fini = bbr_fini,
14178 .tfb_tcp_timer_stop_all = bbr_stopall,
14179 .tfb_tcp_rexmit_tmr = bbr_remxt_tmr,
14180 .tfb_tcp_handoff_ok = bbr_handoff_ok,
14181 .tfb_tcp_mtu_chg = bbr_mtu_chg,
14182 .tfb_pru_options = bbr_pru_options,
14183 .tfb_switch_failed = bbr_switch_failed,
14184 .tfb_flags = TCP_FUNC_OUTPUT_CANDROP | TCP_FUNC_DEFAULT_OK,
14185 };
14186
14187 /*
14188 * bbr_ctloutput() must drop the inpcb lock before performing copyin on
14189 * socket option arguments. When it re-acquires the lock after the copy, it
14190 * has to revalidate that the connection is still valid for the socket
14191 * option.
14192 */
14193 static int
bbr_set_sockopt(struct tcpcb * tp,struct sockopt * sopt)14194 bbr_set_sockopt(struct tcpcb *tp, struct sockopt *sopt)
14195 {
14196 struct epoch_tracker et;
14197 struct inpcb *inp = tptoinpcb(tp);
14198 struct tcp_bbr *bbr;
14199 int32_t error = 0, optval;
14200
14201 switch (sopt->sopt_level) {
14202 case IPPROTO_IPV6:
14203 case IPPROTO_IP:
14204 return (tcp_default_ctloutput(tp, sopt));
14205 }
14206
14207 switch (sopt->sopt_name) {
14208 case TCP_RACK_PACE_MAX_SEG:
14209 case TCP_RACK_MIN_TO:
14210 case TCP_RACK_REORD_THRESH:
14211 case TCP_RACK_REORD_FADE:
14212 case TCP_RACK_TLP_THRESH:
14213 case TCP_RACK_PKT_DELAY:
14214 case TCP_BBR_ALGORITHM:
14215 case TCP_BBR_TSLIMITS:
14216 case TCP_BBR_IWINTSO:
14217 case TCP_BBR_STARTUP_PG:
14218 case TCP_BBR_DRAIN_PG:
14219 case TCP_BBR_PROBE_RTT_INT:
14220 case TCP_BBR_PROBE_RTT_GAIN:
14221 case TCP_BBR_PROBE_RTT_LEN:
14222 case TCP_BBR_STARTUP_LOSS_EXIT:
14223 case TCP_BBR_USEDEL_RATE:
14224 case TCP_BBR_MIN_RTO:
14225 case TCP_BBR_MAX_RTO:
14226 case TCP_BBR_PACE_PER_SEC:
14227 case TCP_DELACK:
14228 case TCP_BBR_PACE_DEL_TAR:
14229 case TCP_BBR_SEND_IWND_IN_TSO:
14230 case TCP_BBR_EXTRA_STATE:
14231 case TCP_BBR_UTTER_MAX_TSO:
14232 case TCP_BBR_MIN_TOPACEOUT:
14233 case TCP_BBR_FLOOR_MIN_TSO:
14234 case TCP_BBR_TSTMP_RAISES:
14235 case TCP_BBR_POLICER_DETECT:
14236 case TCP_BBR_USE_RACK_CHEAT:
14237 case TCP_DATA_AFTER_CLOSE:
14238 case TCP_BBR_HDWR_PACE:
14239 case TCP_BBR_PACE_SEG_MAX:
14240 case TCP_BBR_PACE_SEG_MIN:
14241 case TCP_BBR_PACE_CROSS:
14242 case TCP_BBR_PACE_OH:
14243 case TCP_BBR_TMR_PACE_OH:
14244 case TCP_BBR_RACK_RTT_USE:
14245 case TCP_BBR_RETRAN_WTSO:
14246 break;
14247 default:
14248 return (tcp_default_ctloutput(tp, sopt));
14249 break;
14250 }
14251 INP_WUNLOCK(inp);
14252 error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval));
14253 if (error)
14254 return (error);
14255 INP_WLOCK(inp);
14256 if (inp->inp_flags & INP_DROPPED) {
14257 INP_WUNLOCK(inp);
14258 return (ECONNRESET);
14259 }
14260 if (tp->t_fb != &__tcp_bbr) {
14261 INP_WUNLOCK(inp);
14262 return (ENOPROTOOPT);
14263 }
14264 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
14265 switch (sopt->sopt_name) {
14266 case TCP_BBR_PACE_PER_SEC:
14267 BBR_OPTS_INC(tcp_bbr_pace_per_sec);
14268 bbr->r_ctl.bbr_hptsi_per_second = optval;
14269 break;
14270 case TCP_BBR_PACE_DEL_TAR:
14271 BBR_OPTS_INC(tcp_bbr_pace_del_tar);
14272 bbr->r_ctl.bbr_hptsi_segments_delay_tar = optval;
14273 break;
14274 case TCP_BBR_PACE_SEG_MAX:
14275 BBR_OPTS_INC(tcp_bbr_pace_seg_max);
14276 bbr->r_ctl.bbr_hptsi_segments_max = optval;
14277 break;
14278 case TCP_BBR_PACE_SEG_MIN:
14279 BBR_OPTS_INC(tcp_bbr_pace_seg_min);
14280 bbr->r_ctl.bbr_hptsi_bytes_min = optval;
14281 break;
14282 case TCP_BBR_PACE_CROSS:
14283 BBR_OPTS_INC(tcp_bbr_pace_cross);
14284 bbr->r_ctl.bbr_cross_over = optval;
14285 break;
14286 case TCP_BBR_ALGORITHM:
14287 BBR_OPTS_INC(tcp_bbr_algorithm);
14288 if (optval && (bbr->rc_use_google == 0)) {
14289 /* Turn on the google mode */
14290 bbr_google_mode_on(bbr);
14291 if ((optval > 3) && (optval < 500)) {
14292 /*
14293 * Must be at least greater than .3%
14294 * and must be less than 50.0%.
14295 */
14296 bbr->r_ctl.bbr_google_discount = optval;
14297 }
14298 } else if ((optval == 0) && (bbr->rc_use_google == 1)) {
14299 /* Turn off the google mode */
14300 bbr_google_mode_off(bbr);
14301 }
14302 break;
14303 case TCP_BBR_TSLIMITS:
14304 BBR_OPTS_INC(tcp_bbr_tslimits);
14305 if (optval == 1)
14306 bbr->rc_use_ts_limit = 1;
14307 else if (optval == 0)
14308 bbr->rc_use_ts_limit = 0;
14309 else
14310 error = EINVAL;
14311 break;
14312
14313 case TCP_BBR_IWINTSO:
14314 BBR_OPTS_INC(tcp_bbr_iwintso);
14315 if ((optval >= 0) && (optval < 128)) {
14316 uint32_t twin;
14317
14318 bbr->rc_init_win = optval;
14319 twin = bbr_initial_cwnd(bbr, tp);
14320 if ((bbr->rc_past_init_win == 0) && (twin > tp->snd_cwnd))
14321 tp->snd_cwnd = twin;
14322 else
14323 error = EBUSY;
14324 } else
14325 error = EINVAL;
14326 break;
14327 case TCP_BBR_STARTUP_PG:
14328 BBR_OPTS_INC(tcp_bbr_startup_pg);
14329 if ((optval > 0) && (optval < BBR_MAX_GAIN_VALUE)) {
14330 bbr->r_ctl.rc_startup_pg = optval;
14331 if (bbr->rc_bbr_state == BBR_STATE_STARTUP) {
14332 bbr->r_ctl.rc_bbr_hptsi_gain = optval;
14333 }
14334 } else
14335 error = EINVAL;
14336 break;
14337 case TCP_BBR_DRAIN_PG:
14338 BBR_OPTS_INC(tcp_bbr_drain_pg);
14339 if ((optval > 0) && (optval < BBR_MAX_GAIN_VALUE))
14340 bbr->r_ctl.rc_drain_pg = optval;
14341 else
14342 error = EINVAL;
14343 break;
14344 case TCP_BBR_PROBE_RTT_LEN:
14345 BBR_OPTS_INC(tcp_bbr_probertt_len);
14346 if (optval <= 1)
14347 reset_time_small(&bbr->r_ctl.rc_rttprop, (optval * USECS_IN_SECOND));
14348 else
14349 error = EINVAL;
14350 break;
14351 case TCP_BBR_PROBE_RTT_GAIN:
14352 BBR_OPTS_INC(tcp_bbr_probertt_gain);
14353 if (optval <= BBR_UNIT)
14354 bbr->r_ctl.bbr_rttprobe_gain_val = optval;
14355 else
14356 error = EINVAL;
14357 break;
14358 case TCP_BBR_PROBE_RTT_INT:
14359 BBR_OPTS_INC(tcp_bbr_probe_rtt_int);
14360 if (optval > 1000)
14361 bbr->r_ctl.rc_probertt_int = optval;
14362 else
14363 error = EINVAL;
14364 break;
14365 case TCP_BBR_MIN_TOPACEOUT:
14366 BBR_OPTS_INC(tcp_bbr_topaceout);
14367 if (optval == 0) {
14368 bbr->no_pacing_until = 0;
14369 bbr->rc_no_pacing = 0;
14370 } else if (optval <= 0x00ff) {
14371 bbr->no_pacing_until = optval;
14372 if ((bbr->r_ctl.rc_pkt_epoch < bbr->no_pacing_until) &&
14373 (bbr->rc_bbr_state == BBR_STATE_STARTUP)){
14374 /* Turn on no pacing */
14375 bbr->rc_no_pacing = 1;
14376 }
14377 } else
14378 error = EINVAL;
14379 break;
14380 case TCP_BBR_STARTUP_LOSS_EXIT:
14381 BBR_OPTS_INC(tcp_bbr_startup_loss_exit);
14382 bbr->rc_loss_exit = optval;
14383 break;
14384 case TCP_BBR_USEDEL_RATE:
14385 error = EINVAL;
14386 break;
14387 case TCP_BBR_MIN_RTO:
14388 BBR_OPTS_INC(tcp_bbr_min_rto);
14389 bbr->r_ctl.rc_min_rto_ms = optval;
14390 break;
14391 case TCP_BBR_MAX_RTO:
14392 BBR_OPTS_INC(tcp_bbr_max_rto);
14393 bbr->rc_max_rto_sec = optval;
14394 break;
14395 case TCP_RACK_MIN_TO:
14396 /* Minimum time between rack t-o's in ms */
14397 BBR_OPTS_INC(tcp_rack_min_to);
14398 bbr->r_ctl.rc_min_to = optval;
14399 break;
14400 case TCP_RACK_REORD_THRESH:
14401 /* RACK reorder threshold (shift amount) */
14402 BBR_OPTS_INC(tcp_rack_reord_thresh);
14403 if ((optval > 0) && (optval < 31))
14404 bbr->r_ctl.rc_reorder_shift = optval;
14405 else
14406 error = EINVAL;
14407 break;
14408 case TCP_RACK_REORD_FADE:
14409 /* Does reordering fade after ms time */
14410 BBR_OPTS_INC(tcp_rack_reord_fade);
14411 bbr->r_ctl.rc_reorder_fade = optval;
14412 break;
14413 case TCP_RACK_TLP_THRESH:
14414 /* RACK TLP theshold i.e. srtt+(srtt/N) */
14415 BBR_OPTS_INC(tcp_rack_tlp_thresh);
14416 if (optval)
14417 bbr->rc_tlp_threshold = optval;
14418 else
14419 error = EINVAL;
14420 break;
14421 case TCP_BBR_USE_RACK_CHEAT:
14422 BBR_OPTS_INC(tcp_use_rackcheat);
14423 if (bbr->rc_use_google) {
14424 error = EINVAL;
14425 break;
14426 }
14427 BBR_OPTS_INC(tcp_rack_cheat);
14428 if (optval)
14429 bbr->bbr_use_rack_cheat = 1;
14430 else
14431 bbr->bbr_use_rack_cheat = 0;
14432 break;
14433 case TCP_BBR_FLOOR_MIN_TSO:
14434 BBR_OPTS_INC(tcp_utter_max_tso);
14435 if ((optval >= 0) && (optval < 40))
14436 bbr->r_ctl.bbr_hptsi_segments_floor = optval;
14437 else
14438 error = EINVAL;
14439 break;
14440 case TCP_BBR_UTTER_MAX_TSO:
14441 BBR_OPTS_INC(tcp_utter_max_tso);
14442 if ((optval >= 0) && (optval < 0xffff))
14443 bbr->r_ctl.bbr_utter_max = optval;
14444 else
14445 error = EINVAL;
14446 break;
14447
14448 case TCP_BBR_EXTRA_STATE:
14449 BBR_OPTS_INC(tcp_extra_state);
14450 if (optval)
14451 bbr->rc_use_idle_restart = 1;
14452 else
14453 bbr->rc_use_idle_restart = 0;
14454 break;
14455 case TCP_BBR_SEND_IWND_IN_TSO:
14456 BBR_OPTS_INC(tcp_iwnd_tso);
14457 if (optval) {
14458 bbr->bbr_init_win_cheat = 1;
14459 if (bbr->rc_past_init_win == 0) {
14460 uint32_t cts;
14461 cts = tcp_get_usecs(&bbr->rc_tv);
14462 tcp_bbr_tso_size_check(bbr, cts);
14463 }
14464 } else
14465 bbr->bbr_init_win_cheat = 0;
14466 break;
14467 case TCP_BBR_HDWR_PACE:
14468 BBR_OPTS_INC(tcp_hdwr_pacing);
14469 if (optval){
14470 bbr->bbr_hdw_pace_ena = 1;
14471 bbr->bbr_attempt_hdwr_pace = 0;
14472 } else {
14473 bbr->bbr_hdw_pace_ena = 0;
14474 #ifdef RATELIMIT
14475 if (bbr->r_ctl.crte != NULL) {
14476 tcp_rel_pacing_rate(bbr->r_ctl.crte, tp);
14477 bbr->r_ctl.crte = NULL;
14478 }
14479 #endif
14480 }
14481 break;
14482
14483 case TCP_DELACK:
14484 BBR_OPTS_INC(tcp_delack);
14485 if (optval < 100) {
14486 if (optval == 0) /* off */
14487 tp->t_delayed_ack = 0;
14488 else if (optval == 1) /* on which is 2 */
14489 tp->t_delayed_ack = 2;
14490 else /* higher than 2 and less than 100 */
14491 tp->t_delayed_ack = optval;
14492 if (tp->t_flags & TF_DELACK) {
14493 tp->t_flags &= ~TF_DELACK;
14494 tp->t_flags |= TF_ACKNOW;
14495 NET_EPOCH_ENTER(et);
14496 bbr_output(tp);
14497 NET_EPOCH_EXIT(et);
14498 }
14499 } else
14500 error = EINVAL;
14501 break;
14502 case TCP_RACK_PKT_DELAY:
14503 /* RACK added ms i.e. rack-rtt + reord + N */
14504 BBR_OPTS_INC(tcp_rack_pkt_delay);
14505 bbr->r_ctl.rc_pkt_delay = optval;
14506 break;
14507
14508 case TCP_BBR_RETRAN_WTSO:
14509 BBR_OPTS_INC(tcp_retran_wtso);
14510 if (optval)
14511 bbr->rc_resends_use_tso = 1;
14512 else
14513 bbr->rc_resends_use_tso = 0;
14514 break;
14515 case TCP_DATA_AFTER_CLOSE:
14516 BBR_OPTS_INC(tcp_data_ac);
14517 if (optval)
14518 bbr->rc_allow_data_af_clo = 1;
14519 else
14520 bbr->rc_allow_data_af_clo = 0;
14521 break;
14522 case TCP_BBR_POLICER_DETECT:
14523 BBR_OPTS_INC(tcp_policer_det);
14524 if (bbr->rc_use_google == 0)
14525 error = EINVAL;
14526 else if (optval)
14527 bbr->r_use_policer = 1;
14528 else
14529 bbr->r_use_policer = 0;
14530 break;
14531
14532 case TCP_BBR_TSTMP_RAISES:
14533 BBR_OPTS_INC(tcp_ts_raises);
14534 if (optval)
14535 bbr->ts_can_raise = 1;
14536 else
14537 bbr->ts_can_raise = 0;
14538 break;
14539 case TCP_BBR_TMR_PACE_OH:
14540 BBR_OPTS_INC(tcp_pacing_oh_tmr);
14541 if (bbr->rc_use_google) {
14542 error = EINVAL;
14543 } else {
14544 if (optval)
14545 bbr->r_ctl.rc_incr_tmrs = 1;
14546 else
14547 bbr->r_ctl.rc_incr_tmrs = 0;
14548 }
14549 break;
14550 case TCP_BBR_PACE_OH:
14551 BBR_OPTS_INC(tcp_pacing_oh);
14552 if (bbr->rc_use_google) {
14553 error = EINVAL;
14554 } else {
14555 if (optval > (BBR_INCL_TCP_OH|
14556 BBR_INCL_IP_OH|
14557 BBR_INCL_ENET_OH)) {
14558 error = EINVAL;
14559 break;
14560 }
14561 if (optval & BBR_INCL_TCP_OH)
14562 bbr->r_ctl.rc_inc_tcp_oh = 1;
14563 else
14564 bbr->r_ctl.rc_inc_tcp_oh = 0;
14565 if (optval & BBR_INCL_IP_OH)
14566 bbr->r_ctl.rc_inc_ip_oh = 1;
14567 else
14568 bbr->r_ctl.rc_inc_ip_oh = 0;
14569 if (optval & BBR_INCL_ENET_OH)
14570 bbr->r_ctl.rc_inc_enet_oh = 1;
14571 else
14572 bbr->r_ctl.rc_inc_enet_oh = 0;
14573 }
14574 break;
14575 default:
14576 return (tcp_default_ctloutput(tp, sopt));
14577 break;
14578 }
14579 tcp_log_socket_option(tp, sopt->sopt_name, optval, error);
14580 INP_WUNLOCK(inp);
14581 return (error);
14582 }
14583
14584 /*
14585 * return 0 on success, error-num on failure
14586 */
14587 static int
bbr_get_sockopt(struct tcpcb * tp,struct sockopt * sopt)14588 bbr_get_sockopt(struct tcpcb *tp, struct sockopt *sopt)
14589 {
14590 struct inpcb *inp = tptoinpcb(tp);
14591 struct tcp_bbr *bbr;
14592 int32_t error, optval;
14593
14594 bbr = (struct tcp_bbr *)tp->t_fb_ptr;
14595 if (bbr == NULL) {
14596 INP_WUNLOCK(inp);
14597 return (EINVAL);
14598 }
14599 /*
14600 * Because all our options are either boolean or an int, we can just
14601 * pull everything into optval and then unlock and copy. If we ever
14602 * add a option that is not a int, then this will have quite an
14603 * impact to this routine.
14604 */
14605 switch (sopt->sopt_name) {
14606 case TCP_BBR_PACE_PER_SEC:
14607 optval = bbr->r_ctl.bbr_hptsi_per_second;
14608 break;
14609 case TCP_BBR_PACE_DEL_TAR:
14610 optval = bbr->r_ctl.bbr_hptsi_segments_delay_tar;
14611 break;
14612 case TCP_BBR_PACE_SEG_MAX:
14613 optval = bbr->r_ctl.bbr_hptsi_segments_max;
14614 break;
14615 case TCP_BBR_MIN_TOPACEOUT:
14616 optval = bbr->no_pacing_until;
14617 break;
14618 case TCP_BBR_PACE_SEG_MIN:
14619 optval = bbr->r_ctl.bbr_hptsi_bytes_min;
14620 break;
14621 case TCP_BBR_PACE_CROSS:
14622 optval = bbr->r_ctl.bbr_cross_over;
14623 break;
14624 case TCP_BBR_ALGORITHM:
14625 optval = bbr->rc_use_google;
14626 break;
14627 case TCP_BBR_TSLIMITS:
14628 optval = bbr->rc_use_ts_limit;
14629 break;
14630 case TCP_BBR_IWINTSO:
14631 optval = bbr->rc_init_win;
14632 break;
14633 case TCP_BBR_STARTUP_PG:
14634 optval = bbr->r_ctl.rc_startup_pg;
14635 break;
14636 case TCP_BBR_DRAIN_PG:
14637 optval = bbr->r_ctl.rc_drain_pg;
14638 break;
14639 case TCP_BBR_PROBE_RTT_INT:
14640 optval = bbr->r_ctl.rc_probertt_int;
14641 break;
14642 case TCP_BBR_PROBE_RTT_LEN:
14643 optval = (bbr->r_ctl.rc_rttprop.cur_time_limit / USECS_IN_SECOND);
14644 break;
14645 case TCP_BBR_PROBE_RTT_GAIN:
14646 optval = bbr->r_ctl.bbr_rttprobe_gain_val;
14647 break;
14648 case TCP_BBR_STARTUP_LOSS_EXIT:
14649 optval = bbr->rc_loss_exit;
14650 break;
14651 case TCP_BBR_USEDEL_RATE:
14652 error = EINVAL;
14653 break;
14654 case TCP_BBR_MIN_RTO:
14655 optval = bbr->r_ctl.rc_min_rto_ms;
14656 break;
14657 case TCP_BBR_MAX_RTO:
14658 optval = bbr->rc_max_rto_sec;
14659 break;
14660 case TCP_RACK_PACE_MAX_SEG:
14661 /* Max segments in a pace */
14662 optval = bbr->r_ctl.rc_pace_max_segs;
14663 break;
14664 case TCP_RACK_MIN_TO:
14665 /* Minimum time between rack t-o's in ms */
14666 optval = bbr->r_ctl.rc_min_to;
14667 break;
14668 case TCP_RACK_REORD_THRESH:
14669 /* RACK reorder threshold (shift amount) */
14670 optval = bbr->r_ctl.rc_reorder_shift;
14671 break;
14672 case TCP_RACK_REORD_FADE:
14673 /* Does reordering fade after ms time */
14674 optval = bbr->r_ctl.rc_reorder_fade;
14675 break;
14676 case TCP_BBR_USE_RACK_CHEAT:
14677 /* Do we use the rack cheat for rxt */
14678 optval = bbr->bbr_use_rack_cheat;
14679 break;
14680 case TCP_BBR_FLOOR_MIN_TSO:
14681 optval = bbr->r_ctl.bbr_hptsi_segments_floor;
14682 break;
14683 case TCP_BBR_UTTER_MAX_TSO:
14684 optval = bbr->r_ctl.bbr_utter_max;
14685 break;
14686 case TCP_BBR_SEND_IWND_IN_TSO:
14687 /* Do we send TSO size segments initially */
14688 optval = bbr->bbr_init_win_cheat;
14689 break;
14690 case TCP_BBR_EXTRA_STATE:
14691 optval = bbr->rc_use_idle_restart;
14692 break;
14693 case TCP_RACK_TLP_THRESH:
14694 /* RACK TLP theshold i.e. srtt+(srtt/N) */
14695 optval = bbr->rc_tlp_threshold;
14696 break;
14697 case TCP_RACK_PKT_DELAY:
14698 /* RACK added ms i.e. rack-rtt + reord + N */
14699 optval = bbr->r_ctl.rc_pkt_delay;
14700 break;
14701 case TCP_BBR_RETRAN_WTSO:
14702 optval = bbr->rc_resends_use_tso;
14703 break;
14704 case TCP_DATA_AFTER_CLOSE:
14705 optval = bbr->rc_allow_data_af_clo;
14706 break;
14707 case TCP_DELACK:
14708 optval = tp->t_delayed_ack;
14709 break;
14710 case TCP_BBR_HDWR_PACE:
14711 optval = bbr->bbr_hdw_pace_ena;
14712 break;
14713 case TCP_BBR_POLICER_DETECT:
14714 optval = bbr->r_use_policer;
14715 break;
14716 case TCP_BBR_TSTMP_RAISES:
14717 optval = bbr->ts_can_raise;
14718 break;
14719 case TCP_BBR_TMR_PACE_OH:
14720 optval = bbr->r_ctl.rc_incr_tmrs;
14721 break;
14722 case TCP_BBR_PACE_OH:
14723 optval = 0;
14724 if (bbr->r_ctl.rc_inc_tcp_oh)
14725 optval |= BBR_INCL_TCP_OH;
14726 if (bbr->r_ctl.rc_inc_ip_oh)
14727 optval |= BBR_INCL_IP_OH;
14728 if (bbr->r_ctl.rc_inc_enet_oh)
14729 optval |= BBR_INCL_ENET_OH;
14730 break;
14731 default:
14732 return (tcp_default_ctloutput(tp, sopt));
14733 break;
14734 }
14735 INP_WUNLOCK(inp);
14736 error = sooptcopyout(sopt, &optval, sizeof optval);
14737 return (error);
14738 }
14739
14740 /*
14741 * return 0 on success, error-num on failure
14742 */
14743 static int
bbr_ctloutput(struct tcpcb * tp,struct sockopt * sopt)14744 bbr_ctloutput(struct tcpcb *tp, struct sockopt *sopt)
14745 {
14746 if (sopt->sopt_dir == SOPT_SET) {
14747 return (bbr_set_sockopt(tp, sopt));
14748 } else if (sopt->sopt_dir == SOPT_GET) {
14749 return (bbr_get_sockopt(tp, sopt));
14750 } else {
14751 panic("%s: sopt_dir $%d", __func__, sopt->sopt_dir);
14752 }
14753 }
14754
14755 static const char *bbr_stack_names[] = {
14756 __XSTRING(STACKNAME),
14757 #ifdef STACKALIAS
14758 __XSTRING(STACKALIAS),
14759 #endif
14760 };
14761
14762 static bool bbr_mod_inited = false;
14763
14764 static int
tcp_addbbr(module_t mod,int32_t type,void * data)14765 tcp_addbbr(module_t mod, int32_t type, void *data)
14766 {
14767 int32_t err = 0;
14768 int num_stacks;
14769
14770 switch (type) {
14771 case MOD_LOAD:
14772 printf("Attempting to load " __XSTRING(MODNAME) "\n");
14773 bbr_zone = uma_zcreate(__XSTRING(MODNAME) "_map",
14774 sizeof(struct bbr_sendmap),
14775 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
14776 bbr_pcb_zone = uma_zcreate(__XSTRING(MODNAME) "_pcb",
14777 sizeof(struct tcp_bbr),
14778 NULL, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0);
14779 sysctl_ctx_init(&bbr_sysctl_ctx);
14780 bbr_sysctl_root = SYSCTL_ADD_NODE(&bbr_sysctl_ctx,
14781 SYSCTL_STATIC_CHILDREN(_net_inet_tcp),
14782 OID_AUTO,
14783 #ifdef STACKALIAS
14784 __XSTRING(STACKALIAS),
14785 #else
14786 __XSTRING(STACKNAME),
14787 #endif
14788 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
14789 "");
14790 if (bbr_sysctl_root == NULL) {
14791 printf("Failed to add sysctl node\n");
14792 err = EFAULT;
14793 goto free_uma;
14794 }
14795 bbr_init_sysctls();
14796 num_stacks = nitems(bbr_stack_names);
14797 err = register_tcp_functions_as_names(&__tcp_bbr, M_WAITOK,
14798 bbr_stack_names, &num_stacks);
14799 if (err) {
14800 printf("Failed to register %s stack name for "
14801 "%s module\n", bbr_stack_names[num_stacks],
14802 __XSTRING(MODNAME));
14803 sysctl_ctx_free(&bbr_sysctl_ctx);
14804 free_uma:
14805 uma_zdestroy(bbr_zone);
14806 uma_zdestroy(bbr_pcb_zone);
14807 bbr_counter_destroy();
14808 printf("Failed to register " __XSTRING(MODNAME)
14809 " module err:%d\n", err);
14810 return (err);
14811 }
14812 tcp_lro_reg_mbufq();
14813 bbr_mod_inited = true;
14814 printf(__XSTRING(MODNAME) " is now available\n");
14815 break;
14816 case MOD_QUIESCE:
14817 err = deregister_tcp_functions(&__tcp_bbr, true, false);
14818 break;
14819 case MOD_UNLOAD:
14820 err = deregister_tcp_functions(&__tcp_bbr, false, true);
14821 if (err == EBUSY)
14822 break;
14823 if (bbr_mod_inited) {
14824 uma_zdestroy(bbr_zone);
14825 uma_zdestroy(bbr_pcb_zone);
14826 sysctl_ctx_free(&bbr_sysctl_ctx);
14827 bbr_counter_destroy();
14828 printf(__XSTRING(MODNAME)
14829 " is now no longer available\n");
14830 bbr_mod_inited = false;
14831 }
14832 tcp_lro_dereg_mbufq();
14833 err = 0;
14834 break;
14835 default:
14836 return (EOPNOTSUPP);
14837 }
14838 return (err);
14839 }
14840
14841 static moduledata_t tcp_bbr = {
14842 .name = __XSTRING(MODNAME),
14843 .evhand = tcp_addbbr,
14844 .priv = 0
14845 };
14846
14847 MODULE_VERSION(MODNAME, 1);
14848 DECLARE_MODULE(MODNAME, tcp_bbr, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
14849 MODULE_DEPEND(MODNAME, tcphpts, 1, 1, 1);
14850